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HomeMy WebLinkAboutPermit File 2202 15th Street (2) i'-A . 7 o'''•• Cityof Anacortes 0 ,, Invoice/Permit#: BLD-2017-0349 904 6th Street Applied date: 07/07/2017 ._ P.O.Box 547 Issue date: 5" :0; Anacortes, WA 98221-0547 ''', ,� 010_r1,' t (360) 293-1901 Expire date: 01/03/2019 Job Address: 2202 15TH ST Permit Type: Single Family Residence Permit ANACORTES WA 98221 Project: APN: P56250 Remarks: sfr Owner: LANDED GENTRY DEVELOPMENT Contractor: LANDED GENTRY DEVELOPMENT INC Address: 504 E FAIRHAVEN AVE Address: 504 E FAIRHAVEN AVE BURLINGTON WA 98233-1846 BURLINGTON WA 98233-1846 Phone: (360) 755-9021 Phone: (360)755-9021 License#: LANDEGD062D4 General Information: Fees: Plan Review Deposit 200.00 State Building Code Fee 4.50 Sewer Inspection Fee 50.00 Storm Drain GFC-Residential 1,550.93 Sewer GFC-Residential 9,206.33 Park Impact Fee 615.00 1 Traffic Impact Fee 900.00 Total Calculated: 12,526.76 Deposits/Receipts: 0.00 Total Due: 12,526.76 a —i -1 -c1 1,0 .. r- '-.+. ID ° : a r n 'A -J -• I a a 1 CO ' i a CO 0 •U I'.. ON 44. H• 2 y, = p ca ,t .. rs .t r I 1 lii rf• -i U ,-. T: 1 r- CD a' o a G => G • o CAI 2 C4 c,. := q, •'o ITI i/ r•+ .t G' c: rr, f.. cr., '-+•ice I� :�, it, ✓l- 'L • m 7 W -n r.. THIS PERMIT BECOMES NULL AND VOID IF WORK OR CONSTRUCTION AUTHORIZED IS NOT COMMENCED WITHIN 180 DA'lS,glj Ili' CONSTRUCTION OR WORK IS SUSPENDED OR ABANDONED FOR A PERIOD OF 180 DAYS AT ANY TIME AFTER WORK IS COMMEiJ : D; '1/ HEREBY CERTIFY THAT I HAVE READ AND EXAMINED THIS APPLICATION AND KNOW THE SAME TO BE TRUE AND CORRECT.ALL PI l 3}Jt- OF LAWS AND ORDINANCES GOVERNING THIS TYPE OF WORK WILL BE COMPLIED WITH WHETHER SPECIFIED HEREIN OR MCT;�7'¢•IF,••' GRANTING OF A PERMIT DOES NOT PRESUME TO GIVE AUTHORITY TO VIOLATE OR CANCEL THE PROVISIONS OF ANY OTHER OT,ige=pP ' LOCAL LAW REGULATING CONSTRUCTION OR THE PERFORMANCE OF CONSTRUCTION. ,-- • -.J fir? ^"t-.,1 •a 'N1' „k m /71 441 014(7)(O-TA--- CD CDn IGNATURE OF OWNER OR AUTHORIZED AGENT r 1...)ISSUED BY _' m ••1 rt CERTIFICATE OF OCCUPANCY This is to certify that the below listed building or structure has been inspected and occupancy is hereby authorized: Description: New Single Family Residence Location: 2202 15th St. Owner: Landed Gentry Development Constructed by: Landed Gentry Development INC. Building Permit#: BLD-2017-0349 Date issued: 11/20/2017 Use Zone: R2 Dated: September 19 2018 Authorizing Official: r CITY OF ANACORTES "AS-BUILT" y' Se'"e`' ' CONTRACTOR: � • W`�- ❑swro PLAT/DIVISION: ' / BLOCK LOT ADDRESS: ),4-C) ' .J . DATE: \a/3.1,i1 1 PERMT.T# •LYE o\ \-0 ‘FLALE , S T RIE L T - r.� u l _ �� , x _ `hhil �'� ' - - - aa6 . , , . _ . , _Tiet,_,- 0.?:, I,, , ,,._. , . ____. _ ,. ,......c14,... . , _ _ _ ..,...._____. ., _1 .. , . . __ . . . . . ___________ , ____ _, ..., . ___ . . , ' --is'''N 4„,„ . .. , _ . . , .... , .......,_ ,__. _ _ _ _ _ . ,i . LOCATE STREET(S)ON GRID MAP . ANACORTES PUBLIC WORKS DEPARTMENT 0 O Steven Lange, Project Manager P.O.BOX 547,ANACORTES,WA 98221 PH(360)293-1920 'P.2 i 7 E-MAIL:stevel@cityofanacortes.org FAX(360)293-1938 Memo Date: July 10, 2017 To: Paul Ingalls, Plans Examiner From: Steven Lange • Subject: Site Plan Review#1 for 220215th Street cc: Eric Shjarback, Justin Symonds The submitted site plan for 2202 15t" Street was reviewed by the Public Works Engineering Department on July 10, 2017. • 07-07-17: Submittal to Public Works Engineering • 07-10-17: Public Works review and memo back to Building Department The following comments are provided: • Proposed project is adjacent to existing curb, gutter and sidewalk. This project will need to extend curb, gutter and sidewalk to the most westerly property boundary and make necessary adjustments to allow for smooth transitions both vertically and horizontally. • Improvements shall be designed by a Professional Engineer, licensed in the State of Washington. • Project is subject to Engineering Plan Review Fees (0.5%) and Construction Inspecton Fees (1.5% +500.00). • Maximum driveway width at the street shall be 20-feet and shall be located at the westerly side of the property, as shown on the attached vicinity map, dated May 31, 2017 • The attached vicinity map was provided to the owner of Landed Gentry at his request. E� 4 ti o ^/ • Water • Wastewater • Streets • Storm Drainage • Engineering • Solid Waste �1�� • Transportation •Equipment • Capital Projects • Development Services •p.w. 1 `t: J • I I I I I I iiN45,8' s k J44 I H t I i I - 1 1 n 1 Ti 20t i i it I ° 1 --�tj r ! I i i 1 t 2202 - ! I i � `— 1 ! ! w 1 �F.�,� 1 I 3 11 A I u 15 16 1 7 � � � � � o I 20 ; ) , I >CVVEP� POLE I EXISTING 1 1 J r /f Q / 03 __________,_15TH_sT,.._______________ .,%. AP AC W . ice, ' = �T -ate _� _,._.._.. I 1 p < 145 FISI / 'r 11 24?'.5 I2�JE 1 i \IV,Ii. V. h If ! ,' V 7 F !� t 1 `��4�- �z_0 Z„ I G-�7)-{ ,)-r- A �ut21'��i`uT t r�r 1 _11\i _ _..— �i �>5 c�.fit 2 11 tt J . 7; -E`c1.,....-,-1 l�r-;�0t •. �(1G�?i�:a 1 1 !4_:� z?_1I.i6 fs i)l"NN,�?i�`�. SDMH TYPE2 RIM=69.31' INV=63.81' EX. 6'SONG. SS SLOPE=,0060 FT/FT 1 - ~roc / INEX. SSHH? 104;92' E II RIM=7013' — — � — '� `�� Q INV.61.88' LEGEND / ' FENCE ---X X X X--- / ",� 40' _I GAS -s ) UNDERGROUND uGP POWER 1- SANITARY ;�) SEWER �7 J 3 o A STORM Sy ao END OF w La SEWER c, GUY WIRE -� W o w % WATER ..i N MAIN .-_X- in H I i ) Power Vault w a Sanit Basin e / Sanitary Sewer Clean Out ® Ow z Sanitary Sewer Man Hole LLB Fire Hydrant A — EXIST. Q Water Gate Valve Water Meter BUILDING L_7 \ o �r N = 2205 15TH STREET =-,`- TOPOGRAPHY SURVEY 104.92' E\J _- '� d�ULT / P� COMPLETE ON JUNE 13, 2017 �,3__ _ �_ �_ J R-u� _ _ SI EWALK I DALE HERRIGSTAD PLS 1 i' RA P '`' --- EDGE OF-ASPHALT END OFF\\5' 15TH STREET ASPHAL1\ AM ASPHALT' RAMP GRAPHIC SCALE - - - - '�^ - 15 0 15 30 60 EN — _ ( INFEST ) 1 inch = 30 ft. FIRE d HYDRANT DATE HERRIGSTAD ENGINEERING & SURVEYING 2205 15TH STREET FOR LANDED GENTRY 6-13-2017 4320 WHISTLE LAKE ROAD TOPOGRAPHY SURVEY SCALE: ANACORTES, WA 98221 299-8804 N❑TED Fyrrce, Groc From: Cricchio, Kevin Sent: Tuesday, July 11, 2017 2:16 PM To: Fyrrce, Groc Cc: Ingalls, Paul Subject: BLD-2017-0349, 2202 15th Street 7-11-17 RE: BLD-2017-0349, 2202_15th Street Groc, I have completed my review of the building permit application for 2202 15th. The following revisions are required: 1. Show location of all existing buildings on the site plan. If any existing structure is proposed for demolition, a demolition permit is required. 2. The plans reference an ADU. If this is correct, an ADU permit is required prior to building permit issuance. 3. Per AMC Chapter 16.50, one tree is required per 1,000 square feet of lot area. Therefore, since the property is—10,475 square feet, ten (10)trees is required. On a landscape plan please show the location of said trees. Specify either the common name or species. Native vegetation is preferred. 4. Please prepare a landscape plan. Twenty (20) percent of the site needs to be landscaped per AMC 17.41.020(G). Planting areas along street frontages shall be a minimum of fifteen (15)feet wide with trees planted at an average of thirty feet apart per AMC 17.41.020(D). Please specify on the landscape plan what type of plants (common name or species) will be planted and where they will be located. Native vegetation is preferred. Kevin Cricchio, AICP, WPIT I Associate Planner I Planning, Community & Economic Development Dept. City of Anacortes I P.O. Box 547 1904 6th Street I Anacortes, WA 98221 360.293.1937 (work) I kevinc©cityofanacortes.orq www.cityofanacortes.orq My incoming and outgoing email messages are subject to public disclosure requirements per RCW 42.56. 1 Anacortes Planning& Community Development Dept. a‘o Permit Center >, aos w P.O. Box 547,Anacortes,WA 98221-0547 PH(360)293-1901 Don Measamer,Building Official,Planning Director FAX(360)293-1938 August 4, 2017 Jack Reinstra 504 E. Fairhaven Ave Burlington, WA 98233 RE: Plan Review notes for the proposed New Single Family Residence at 2202 15`1' Street Please address the following items so I can complete the plan review. 1. Please apply for an ADU permit with the necessary documentation with Kait Nelson. 2. Please indicate on floor plans the ADU. 3. Please indicate on the plans that there needs to be R-10 rigid insulation under the entire slab,not just the perimeter,per WSEC Energy Credit la. 4. Please indicate on the plans that the location and what heat recovery ventilation system is being used with the minimum efficiency of 0.85,per WSEC Energy Credit 2c. 5. Please indicate on the plans that the joists need to overlap a minimum of 3 inches over the beams and be nailed together with 3- l Od nails per 2015 IRC R502.6.1. 6. Please indicate on plans that their need to be a bollards in front of the appliances in the garages. 7. On the foundation plan the underfloor beams,that support the joists, are inadequate in the ADU. 8. Please indicate on the stair detail on the plans that the finished nosing of the stairs needs to be 3/4"-1 1/4". 9. Please indicate on the plans that 5/8" Type X Gypsum Wall Board is required on the ceiling of the garage that has living space above and is required to be screwed off at 6" o.c. in the field as well as on the edges. 10. Please indicate on the plans that both garage doors need to be 20-minute fire-rated with self-closing devices. 11. Please indicate on Pt floor electrical plan, of the larger residence,that there needs to be both a smoke detector and a carbon monoxide alarm. 12. There is a note on the Electrical Plan that quotes a non-existing code. Please replace it with the correct one, which is the amended Mechanical Chapter of the 2015 IRC. Please contact me if you have any questions about these notes. Sincerely, Groc Fyrrce Building Inspector City of Anacortes 360-293-1901 • .@ E. 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M PS 1-11 ' \ II 1 < .,,.,1 CJl --a:ca *, {-r' X) >{ GI rn "1 t7i 7C1 :3)) % :r :. x : F� .\ ;' #...... ,4 K- _..ror..,,•••:....F.s..--v-_y, <..... ;s^.^z.'^^".^w«'z^w er a. fr-n�• /„ .R,•°,-• 1" f t �.• )', ;. . h A +,,i y•-:��r't ":T i e F • _.".yq.x .�.. > I. h 'l •• R l77,..,T n• • i .-..................... >. 4,� ... ` Y'. A,� w•-:1a`+...mwr t ..h,.t..,,. ;.>nr„�.:,r:S...._c '. tF.•.,�.-.^{q+.+¢_-�± • .Tr s'. , ,. X j '. ,- , I AVENU � �� I "".4 > : � C.,:3 ODC ) l: t C)I C!, z r't) 6° CURB --.- CURB LOCATED PER PLAN SAW CUT 24' 7 RIGHT OF WAY �' Y,E»R j l C' t.As,;,,, LI^ FROM EDGE OF NEW GUTTER 4' GRAVEL OR CRUSHED ROC E @ 0 ` -j' - �P ` ca EDGE L' i G ,, ftl v .� EXIST,-r 5' d ; ` � PAVEMENT / f"C SIDEWALK© i y, . _., ,fl f I 1 14OV27 ;2017 p t 3 d _ viz` •tG:ST K- t e CITY OF ANACORTF FSsi�,�uL �� E 15T,-- STR`E ROAD S ,_CTION A- ' Y, -, " , , N . T.S.1 (SECTION 5-05 AND SECTION 9 OF THE CURRENT PLANS AND SPECIFICATIONS FOR ROAD BRIDGE AND MUNICIPAL CONSTRUCTION. 0 3' HMA - CL 1/2-INCH P66422 CONFORMING TO SECTION 5-04 OF THE CURRENT STANDARD SPECIFICATIONS, COMPACTED TO A MINIMUM OF 92% RICE DENSITY. WHERE PROPOSED ASPHALT ABUTS EXISTING ASPHALT, THE EXISTING ASPHALT SHALL BE SAW CUT FULL DEPTH AND TACK COATED IMMEDIATELY BEFORE PAVING. ALL SURFACE JOINTS SHALL CURB/GUTTER AND SIDEWALK WORKMANSHIP AND AESTHETICS BE SEALED WITH AR--4000 OR EQUAL 1. CURB/GUI 1 ER AND SIDEWALK CONSTRUCTION SHALL FOLLOW A TRUE AND UNIFORM Q 3' CRUSHED SURFACING TOP COURSE SHALL CONFORM TO SECTION 9-03.9(3) OF THE HORIZONTAL AND VERTICAL ALIGNMENT. CURRENT STANDARD SPECIFICATIONS, COMPACTED TO A MINIMUM OF 95% MAXIMUM DENSITY IN ACCORDANCE WITH ASTM D-1557 TESTING. 2. HE VERTICAL AND HORIZONTAL SURFACE SHALL BE A SMOOTH BROOM FINISH WITH NO DETECTABLE FINISHING BLEMISHES, UNDULATIONS, RIPPI Es, SWELLS, WAVES, RUTS, Q MINIMUM J3' GRAVEL BORROW PER SECTION 9-03.14 (1) OF THE CURRENT STANDARD FURROWS, GRAFF1II CR OTHER OBJECTIONABLE MARKS. THE END RESULT SHALL BE A SPECIFICATIONS COMPACTED TO A MINIMUM ON 95% MAXIMUM DENSITY PER ASTM D-1557 NEAT AND PROFESSIONALLY FINISHED APPEARANCE. I L.STING. PERCENTAGE PASSING THE 1200 SIEVE SHALL NOT EXCEED 5%. DEPENDS ON SOIL CONDITIONS AND MAY BE DEVIATED WITH NEW ENGINEERED CROSS--SECTION, SUBMIT 3. THE EDGE FINISH ADJACENT TO THE EXPANSION JOINT MATERIAL SHALL BE CLEAN PROTOCAL'S SIEVE TO CITY. AND FREE OF EXCESS SLURRY. THE EXPANSION JOINT MATERIAL SHALL BE TRIMMED TO A LEVEL EVEN WITH THE ADJACENT CONCRETE RESULTING IN A NEAT AND ® THE EXCAVATED SUBGRADE SHALL BE FREE OF TOPSOIL ORGANICS, AND OTHER PROFESSIONALLY FINISHED APPEARANCE. DELETERIOUS MATERIAL, COMPACTED TO A MINIMUM OF 95% MAXIMUM DENSITY IN 4. THE CITY ENGINEER IN HIS SOLEDISCRETION RESERVES THE kUTHORIY TO ORDER ACCORDANCE WITH ASTM 0-1557 TESTING, PREPARED CONFORMING TO SECTION 2-06.3(1) THE REMOVAL OF SECTIONS OF CURB/GUTTER AND SIDEWALK THAT DO NOT MEET THE OF THE CURRENT STANDARD SPECIFICATIONS. WORKMANSHIP AND AESTHETIC STANDARDS OF THE CITY OF ANACORTES, Q 5' WIDE X 4' THICK CONCRETE SIDEWALK. 5. SECITONS OF NEWLY CONSTRUCTED CURB/GUTTER AND SIDEWALK THAT EXHIBIT 5` WIDE X 6 THICK CONC. SIDEWALK AT DRIVEWAYS. PER CITY STANDARDS. CRACKING FOLLOWING THE CURING, SHALL BE SUBJECT TO REMOVAL AND REPLACEMENT. MI-TEXTILE FABRIC NAY BE REQUIRED DURING CONSTRUCTION. DEPENDANT ON CURRENT SOIL CONDITIONS - CRACKING RESULTING FROM SUB-BASE FAILURE OR CONSTRUCTION SITE DAMAGE & WEATHER. GE©-TEXTILE FABRIC SHALL MEET VSDOT SPECIFICATIONS 9-33 CONSTRUCTION GEOTEXTILE SHALL BE IMMEDIATELY REMOVED AND REPLACED TO THE NEAREST EXPANSION JOINT. SHALL ALSO MEET THE VSDOT QUALITY PRODUCTS LIST, - MINOR HAIR LINE STRESS CRACKS MAY, AT THE DISCRETION OF THE PROJECT MANAGER, BE MONITORED AND RE-EVALUATED FOR POSSIBLE REMOVAL AT THE END OF COMPACTION TESTING IS REQUIRED OF ROAD SUBGRADE AND BALLAST PRIOR TO PLACEMENT OF CRUSHED THE MAINTENANCE PERIOD. SURFACING BY A CERTIFIED SOILS TESTING COMPANY AT A MINIMUM OF 3 RANDOM POINTS ALONG EACH CONTINUOUS SECTION OF ROAD IMPROVEMENT AND BELOW SIDEWALKS. SEE CITY TESTING SCHEDULE, CONTRACTOR IS TO PROVIDE A PROCTOR AND SIEVE ANALYSES PRIOR TO ANY CONSTRUCTION STARTING. HERRIGSTAD ENGINEERING Vic' SURVEYING 15TH STREET 15TH STREET I DATE A zt i7 422C� STLE ROAROADSIDEWALK DESIGN DETAILS 14— ANACORTES, WA 98221 299-8804 2.U2- SCALES PG2EIE2 I NONE ANACORTES PUBLIC WORKS DEPARTMENT G1TY.• � Steven Lange, Project Manager P.O. BOX 547,ANACORTES,WA 98221 PH(360)293-1920 vt. .W E-MAIL:stevel@cityofanacortes.org FAX(360)293-1938 10016 Memo Date: November 14,2017 To: Paul Ingalls, Plans Examiner From:Tim Hohmann for Steven Lange Subject: Drainage Plan Review#1 for 2202 15th Street cc: Eric Shjarback, Justin Symonds, Kait Nelson The submitted drainage plan for 2202 15th Street was reviewed by the Public Works Engineering Department on November 14, 2017. • 11-08-17: Submittal to Public Works Engineering in PM • 11-14-17: Public Works review and memo back to Building Department A drainage report addressing Minimum Requirements#1 to#9, a stormwater site plan and a Geotechnical Report were provided by the Planning Department to Public Works Engineering for review. The following comments are provided: Stormwater Site Plan: • The stormwater site plan and SWPPP are included on the same plan sheet and have been previously reviewed by the planning department. Accordingly additional detailed review of the site plan in regard to MR#1 to#5 was not performed as a part of this review. However the following items were noted as missing during this review: o A reference on the site plan and in the detail to the requirement of BMP T5.13 Post Construction Soil Quality and Depth for all proposed lawn areas in area disturbed by construction activities. Please include on plans and in details. o The site plan needs to be revised to show a 2-fot wide transition zone adjacent to the driveway per BMP T5.12. Include BMP T5.12 detail on BMP detail sheet. Drainage Report: • The site plan shows 5231 SF of impervious area but the report only addresses 5036 SF. This appears to be because the drainage report mentions but does not address the onsite walkways shown on the plan. Please revise drainage report to address all hard surface areas included in the project. Page 2 • The drainage report mentions multiple time that the project is flow control exempt because water is infiltrated by the project there by reducing the effective impervious surface below the thresholds included in MR#7 for the standard flow requirement. This is not an exemption to MR#7 and reference in the drainage report of this being an exemption should be removed from the drainage report. • However this project is flow control exempt according to the applicability requirements of MR #7 as it indirectly discharges to salt water via the City stormwater system. This exemption is not included in the drainage report and should be. • When calculating the house basin and sizing the infiltration trench an infiltration rate of 6.33 in/hr is used. The infiltration rate recommended in the stormwater infiltration evaluation (geotech report) included for review is 1.5 in/hr. The infiltration rate recommended by the project geotech should be used for all drainage calculations and facility sizing. Please recalculate and revise report and facility design using the correct infiltration rate. Alternately the infiltration trench can be sized without calculation in accordance with the Design Criteria contained in BMP 5.10A in section 111-3.1.1 of the DOE manual. • The driveway basin section goes into great detail to calculate the amount of lawn area needed to disperse the driveway runoff. This is BMP T5.12 Sheet flow dispersion. BMP T5.12 contains design guidelines for the width of the vegetated buffer namely—"Provide a 10-foot-wide vegetated buffer for up to 20 feet width of paved impervious surface. Provide an additional 10 feet of vegetated buffer width for each additional 20 feet of impervious surface width or fraction thereof." Please revise drainage report to account for these design guidelines. • The Sidewalk basin of the drainage report needs to correctly reference that the basin is below the thresholds for runoff treatment and flow control and not just "exempt"from runoff control. • It is unclear from the WWHM printouts provided where the 100 year runoff of 0.047cfs for the developed but unmitigated roof basin runoff was calculated. Please provide verification via printout of this flow calculation. • The Minimum Requirement#5 section of the drainage report incorrectly states that because the project is flow control exempt this project is not required to follow List #2. According to the section 1-2.5.5 of the DOE manual — "Projects qualifying as flow control exempt in accordance with 1-2.5.7 Minimum Requirement#7: Flow Control do not have to achieve the LID performance standard, nor consider bioretention, rain gardens, permeable pavement, and full dispersion if using List#1 or List#2. However, those projects must implement BMP T5.13: Post-Construction - Soil Quality and Depth; BMP T5.10A: Downspout Full Infiltration or BMP T5.10B: Downspout Dispersion Systems or BMP T5.10C: Perforated Stub-out Connections; and BMP T5.11: Concentrated Flow Dispersion or BMP T5.12: Sheet Flow Dispersion, if feasible."Once again this flow control exemption is due to the project indirectly discharging to salt water via the City stormwater system not due to falling below the threshold for the standard flow control requirement. The drainage report should be revised to correctly state this and to demonstrate how the applicable List #2 options were addressed for the various project basins. 4..9,, Qom 4v ., • Water • Wastewater • Streets • Storm Drainage • Engineering • Solid Waste • Transportation •Equipment • Capital Projects • Development Services A,pW 4- Page 3 • The Minimum Requirement#5 section of the drainage report needs to address the requirements of BMP T5.13: Post-Construction Soil Quality and Depth for lawn areas disturbed during construction and lawn areas receiving sheet flow for dispersion from the driveway. • The Minimum Requirement#6 section of the drainage report should state that the project does not require the construction of stormwater treatment facilities as the total PGHS is less that 5000SF and the total PGPS is less than 3/4 acre. It can further go on to state that driveway runoff is being treated as it is dispersed per the design guidelines of BMP T5.12 Sheet Flow Dispersion. • The Minimum Requirement#7 section needs to be revised to correctly state the flow control emption with regard to this project. • The Minimum Requirement#9 section of the drainage report need to address ownership and operations and maintenance responsibilities for the stromwater facilities including LID BMPs, as a part of this project. All BMPs receiving private onsite stormwater shall be the responsibility of the lot owner. Please route this request for additional information by the applicant. Additional review will be performed when the necessary revisions are resubmitted. • • DR, i • Water • Wastewater • Streets • Storm Drainage • Engineering • Solid Waste • Transportation•Equipment • Capital Projects • Development Services Ravnik & Associates, In Nkso CIVIL ENGINEERING & LAND USE PLANNI STORM DRAINAGE MEMO for8trir:A 2202 15TH Street OCT • 2011 (BLD-2017 0349) L1 LANDED GENTRY HOMES RESIDENTIAL DEVELOP i.. C9 U September 29, 2017 The residential development proposed herein located at 2202 15th Street in Anacortes, Washington is generally proposed to include construction of a new house and driveway which will create an increase in the stormwater runoff from the site. The new roof area (3,336 sf) and driveway (1,237 sf) propose a total of 4,573 sf of new impervious surfaces on a 10,475 square foot lot. Stormwater runoff from the proposed 3,336 sf house roof area will be collected by downspouts and conveyed via a tight-lined system to a proposed infiltration trench to be installed within the northerly area of the lot. The driveway will be cross-sloped downhill to the west to promote dispersion and infiltration of runoff waters onto adjoining lawn areas which area large enough to infiltrate up to the 100-year storm as noted further on within this report. Additional small areas of impervious surfaces, such as walkways, etc will be graded to disperse runoff via sheet flow onto adjoining areas of lawn/landscaping. As required by the 2014 Department of Ecology Stormwater Manual, the Western Washington Hydrology Model (WWHM), a continuous model software, has been used to calculate pre-developed runoff conditions, post-developed runoff conditions, and the combined performance of storage volume and infiltration discharge. As further described herein, a underground detention/infiltration facility will be used to infiltrate the runoff from the new house. When sizing infiltration trenches using WWHM software, a theoretical riser outlet structure is purposely included within the analysis. If water is found to be released through the riser structure,the volume of rainfall upon the developed site will be considered to have exceeded the system's infiltration and detention capacities, thereby identifying a failure in design. A properly designed and most efficient drainage system will use the infiltration and detention facilities to their maximum capacities without noting any water released through the theoretical riser used in the model. Using WWHM a model was created to demonstrate both the performance of the infiltration trench to infiltrate roof runoff and determine the necessary area required to infiltrate runoff from the proposed driveway area. House Basin: Using an infiltration rate of 6.33 inches_per hour as allowed within the attached geotechnical report prepared by Geotest for this project, it has been determined that it will take 46 if of 2-foot wide x 2-feet deep infiltration trench having a bottom elevation set at 3-feet below surface is necessary to infiltrate 100% of the post-developed runoff P:1Projects1170201docsWrainage Memo 09.29.17.doc 1 1633 LINDAMOOD LANE / P.O. Box 361 • BURLINGTON, WA 98233 PH: (360) 707-2048 • FAX: (360) 707-2216 waters generated from the new 3,336 sf house roof area. As noted within the WWHM view information provided with this memo for the House it is noted that 0 cfs is released via the riser used in the modeling, indicating 100% infiltration has been achieved using the proposed trench, *Proposed Infiltration Trench (tight-lined to downspouts): 46'long x 2' deep x 2' deep Drainrock filled trench(bottom @ 3-feet below ex. grade) Void Ratio: 0.33 Infiltration: 6.33 in/hr(per the geotechnical report prepared by Geotest dated 08/30/17) Refer to WWMH view and Report for the House attached with this memo for more detailed analysis information. Driveway Basin: As an alternative way to look at the driveway dispersion/infiltration provided, the use of WWHIvi allows us to calculate the 100-year flow frequency runoff that will be generated from the 1,237 sf(0.028 acre) of driveway area to be dispersed. Based on this analysis the 100-year storm event runoff values increase from 0.0016 cfs during the predeveloped o er s condition up to 0.0171 cfs for the post developed (concrete) condition. This 0. 1 5 cfs increase in runoff that is anticipated from the conversion of 0.028 acres from forested condition to concrete driveway can easily be infiltrated onto the undeveloped landscape area located to the west of the proposed driveway. Using a 1.50 in/hr infiltration rate from the attached geotechnical report prepared by Geotest, it only will take approximately 493 sf of area to infiltrate the 100-year storm even in an area where there is over 1,200 sf of area available. See equations below: Infiltration Rate Use 1.50 inch/hour 0.0250 inch/min 0.0000347 fps Required Infiltration Area for 0.028 ac driveway for 100-year storm 0.0171 cfs/0.0000347 fps = 493 square feet of area required to infiltrate the runoff from the developed 100-year storm event for the entire driveway area. Since the length of driveway is approximately 40 feet, it is estimated that it will take approximately 12.31 feet of width of vegetation and/or undisturbed soil along the west side of the driveway to infiltrate runoff from the 100-year storm. If° x /2 . 3 / Based on the driveway length of 40 feet, full infiltration will be achieved in 12.31 feet. Summary Based on the previously areas noted, ti ht-lining roof downspouts to a 46-foot long x 2- foot-wide x 2-feet-deep drainrock filled ui"Itra ion ncFi ii its 7wssing driveway runoff onto areas with vegetated flow path length greater than 12.31-feet is sufficient to mitigate P:1Projects1170201docslDrainage Memo 09.29.17.doc 2 the increase in stormwater runoff that will be created by the construction of this new house. Since there is over 28 feet of lawn area located to the west of the proposed new driveway, there is adequate area for runoff waters to be infiltrated onsite based on the 100-year flow frequency rates determined by WWHM software. Since this was determined using continuous model (WWHM) runoff methods that prove the 100-year runoff flow frequency can be infiltrated, this 0.028-acre driveway area can be classified as "ineffective" based on the definition of"Effective Impervious Surface" within the 2014 DOE Manual Volume I-Appendix G. As previously determined using the WWHM analysis, the additional roof area and the new driveway area that will be dispersed and infiltrated is proposed to add 0.077 acres of new roof area and 0.028 acres of new concrete driveway. Accounting for both the house and driveway, even though the driveway area is ineffective as previously noted, only increases the 100-year flow frequency runoff flows from 0.0059 cfs (0.0043 cfs + 0.0016 cfs) for the pre-developed to 0.0642 cfs (0.0471 cfs + .0171 cfs) during the post- developed condition, therefore only a 0.0583 cfs increase, which is less than 0.10 cfs, making this project exempt from DOE Requirement#7-Flow Control as noted below. Per DOE section 2.5.7-Minimum requirement #7-Flow Control a project is exempt from providing flow control is the project if: 1) The project has less than 10,000 square feet of effective impervious surfaces, 2) The project converts less than 3/4 acre of vegetation to lawn for landscape (or converts less than 2.5 acres of native vegetation to pasture), and 3) Through a combination of effective hard surface and converted vegetation areas cause less than a 0.10 cubic feet per second increase in the 100-year flow frequency as estimated using the WWHM model. The analysis determining the difference in flow was conservatively performed using the forested land cover for the predeveloped condition as per the footnote in DOE Manual Volume I-Chapter 2 (page 65) states that the 0.10 cfs increase should be a comparison of the post project runoff to the existing conditions runoff based on the pre-project land cover, or the land cover that existing at the site as of a date when the local jurisdiction first adopted flow control requirements into code. Since this project has shown that proposed driveway area has sufficient area to the west to infiltrate driveway runoff, based on the WWHM flow frequency values,means that the Basin #1 area is technically not an "effective impervious area" (per the definition of "Effective Impervious Surface" (DOE Manual Volume 3-Appendix G). Therefore this results in the project having less than a total of 10,000 square feet of "effective impervious surfaces". In addition the runoff increases less than 0.10 cfs during the 100- year flow frequency based on the WWHM model, therefore this project is exempt from providing Runoff Control as noted. Furthermore, since this is determined to be Flow P:1Projects1170201docslDrainage Memo 09.29.17.doc 3 Control exempt in accordance with DOE Manual section 2.5.7 as noted above, this project is not required to meet LID standards as noted in section 2.5.5-Minimum Requirement 115-On-site Stormwater Management within the DOE Manual. P:1Projectsl170201docslDrainage Memo 09.29.17.doc 4 STORMWATER EXHIBIT INFILTRATION TRENCH DETAIL I AP OXIMATE LOCATION OF 46' LONG x 2' WID X 2' DEEP DRIANROCK I � - i7•I t�INtN IK NCH PUN HOOP UKAINS, I PER INFILTRATION TRENCH DETAIL — b SS ss SS , SS ss S 60 06 a 5S SS `w 5s , SS • 46.00' 10.00' I— ---®70.00'11 I E 1 al °" ttilI ' 4 lif. , I Y 1 Z 1 1-1— _J ROOF LINE I . I i o, PROPOSED SE 1 (a o, I W ROOF AR A = 3,336 SF) I II Z II. i I I I W Q r - - I • _..] ° •32.60' • ° • °,4-- 10.67' --18.00' — a ,, OPE1xWIN 20.00' L I L ,op ° pRW I 104.92' / 8 I . . I •° ° A ° , A \// 1 I , /*Clef _et, / / r + / ---- A A Y A A Y 1 15TH STREET ( - 1— — — — - , A AA A A A A - __ .—...__ _— -— OS as as I i >l N — 1 Ravnik & Associates, Inc. 114.TS CIVIL ENGINEERING do LAND-USE PLANNING STO R M WATE R MA""BY: HLN K33 LINDAYOOD LAN&P.O.BOX 341 BURLINIITDN. EXHIBIT !FM MO)101.201t FAX �: lObZ2K J06 NO. 17026 DAZE OMIT 4"DIA.RIGID PERFORATED PIPE FILTER FABRIC 2' I' FINISHED GRADE :., `� TOP II1i 111=1 .may,.,;..,., .. :\ 1=ll SOIL I- hV J o IA. ^ WASHED ROCK :III—III=1 t � I=III— N ' -' p o o I II�I- TRENCH DEPTH III—I 1� i l I�III—I BOTTOM im—m—m—iTi T iTi iii Ti Till 1 1/2"TO 3/4" INFILTRATION TRENCH SECTION A-A WASHED DRAINROCK Ravnik & Associates, Inc. *Err D `"°°tSCALE N.T.S. CIVIL ENGINEERING do LAND-USE PLANNING INFILTRATION D"A Bw H77 urm,van r4r....aH PH:c6D) 20041 FAX CD,797.22K TRENCH EXHIBIT ""° DAIS 00.211.17 4 SOILS INFORMATION 741 Menne Orive Bellingham,WA 99225 360 733 7318 oaTG 5T 20611-67'Avenue Arlington,WA 982 3E 888 251_5276 360 733_7418 August 30, 2017 Job No. 17-0425 Landed Gentry Homes and Communities 504 East Fairhaven Avenue Burlington, WA 98233 Attn.: Steven Baughn Re: Stormwater Infiltration Evaluation Padilla Adu Development 2202 15th Street Anacortes,Washington Dear Mr. Baugn, As requested, GeoTest Services, Inc. (GTS) is pleased to submit this report summarizing the results of our stormwater infiltration evaluation associated with the proposed single family residence at the subject property in Anacortes, Washington, as shown on the Vicinity Map (Figure 1). The purpose of this evaluation was to assess the existing subsurface conditions for use in designing stormwater infiltration system(s) associated with proposed development. This report summarizes our conclusions and recommendations regarding the potential for onsite stormwater infiltration. Specifically, our services included the following: 1. Evaluation of 3 test pits equally distributed across the subject property. Test pits explorations were advanced to7.5 feet below the ground surface(BGS). 2. Geological review of the information collected during this phase of the investigation in order to provide recommendations for the project. Our findings and recommendations are summarized in this site-specific report and contain the following information: • A site plan showing pertinent existing site features and the approximate location of the explorations accomplished for this project. • Logs of our explorations and results of our laboratory testing including a chart illustrating the soil classification criteria and the terminology and symbols used on the exploration logs. • Laboratory determinations of soil classification, including the long- term infiltration rates of soil encountered. Infiltration rates are based on USDA soil gradation analysis, in general accordance with the 2012 Stormwater Management Manual for Western Washington (SMMWW) amended December 2014. Laboratory evaluation on collected soils included USDA sieve analyses and moisture contents. Page 1 of 7 GeoTest Services,Inc. August 30,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 • A summary of surface and subsurface soil and groundwater conditions observed at the site during our field exploration. The summary includes descriptions of subsurface profiles and the potential seasonal effects of groundwater. The scope of services for this report included stormwater infiltration only, it does not include geotechnical recommendations with regards to the planned building foundation support, settlement, potential seismic considerations such as liquefaction and/or other geologic hazards that may exist within this property. PROJECT DESCRIPTION We understand that there are plans to develop the subject property with a single-family residence with associated stormwater facilities and utilities. As part of the development, the stormwater facilities will be constructed to accommodate onsite stormwater runoff from proposed impervious surfaces. The attached site and exploration map should be considered preliminary. SITE CONDITIONS This section discusses the general surface and subsurface conditions observed at the project site at the time of our field investigation. Interpretations of the site conditions are based on the results of our review of available information, site reconnaissance, subsurface explorations, laboratory testing, and our experience in the project vicinity. Surface Conditions At the time of our visit, the subject property was bordered by single family residences along its western and northern extent and D Avenue and 15th Street to its east and south, respectively. The property contained a 2 bay out building near its southwest corner and was covered in a grass lawn. In general, the property sloped slightly downwards towards the north, with elevation changes being less than about 5 vertical feet. Site Geology Geologic information for the project site was obtained from the'Washington Interactive Geologic Map," published by the Washington State Department of Natural Resouces (DNR). According to this map, deposits at the project consist of Fraser-Age continental glacial till (Qgt). The till is a non-sorted and unstratified mixture of clay, sand pebbles, cobbles, and boulders (diamicton), deposited by glacial ice. The soils encountered in our subsurface explorations are generally consistent with the published geological information and our experience with projects in the nearby vicinity. Page 2 of 7 GeoTest Services, Inc. August 30,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 Subsurface Soil Conditions Subsurface conditions were explored by excavating 3 test pits (TP-1 through TP-3) on June 27, 2017. Approximate locations of these explorations have been plotted on the Site and Exploration Plan, Figure 2. The test pits were advanced with a tracked excavator to depths of 7.5 feet BGS. After test pit explorations were completed, the pits were backfilled with the excavated soils and compacted with the bucket of the excavator. In general, subsurface soils encountered within the area of proposed development consisted of approximately 0.5 to 1 foot of topsoil (soft, brown, moist, organic silt) that overlays 2 to 4 feet of weathered glacial till loose to medium dense, brown, moist, silty sand to slightly silty sand) with very stiff to hard, sandy silt with pebbles and cobbles (glacial till) extending to full depth within all 3 test pit locations. some minor fill soils were located above the weathered till in TP-2 and TP-3. Please refer to the attached exploration logs for more detail (Figures 4 through 5). Groundwater Seepage and Seasonal Groundwater For the purposes of this report, observed groundwater seepage represents either the existing surface of a groundwater table or the surface of perched seepage. The groundwater table is referred to as the atmospheric pressure surface that coincides with the top of the zone of saturation and is the surface that dictates the development design recommendations in this report. Perched seepage is referred to as a saturated zone that develops where a restrictive surface (i.e. dense, fine grained soils or bedrock) limits the vertical, downward migration of near-surface water. The groundwater table or perched seepage surface should be considered when determining methods of earthwork construction but is not used to dictate development design. Groundwater Observations At the time of our visit on June 27, 2017, minor, perched groundwater seepage was observed within the test pits between 4.5 and 6.0 feet BGS. As the region has not, at the time of our site visit, recently experienced precipitation, we interpret the groundwater to be interflow running along the very dense till soils with elevated fines content, generally encountered onsite at approximately 4.5 to 6.0 feet BGS. During periods of extended and/or heavy rainfall we would anticipate that groundwater would be found perched on the very dense till soils with elevated fines content. Seasonal Groundwater Fluctuation Observations A distinct mottled horizon or "rust line," was not encountered within the test pit explorations. Mottling (reddish-brown, orange, or yellow splotches or mottles) is typically indicative of soils that experience fluctuating moisture conditions, generally due to seasonal wetting and drying. Gleyed soils, indicative of poorly drained and potentially restrictive soils, were encountered within the unweathered, very stiff to hard till. Gleyed soils are typically gray or bluish-gray in color and the result of a reduced (non-oxidative) soil state caused by Page 3 of 7 GeoTest Services,Inc. August 30, 2017 2202 15th Street,Anacortes,WA Job No. 17-0425 significant periods of saturation. Gleyed soils are often associated with soils that are restrictive of groundwater flow. Please note that changes to soil color and morphology may take significant periods of time to develop and may not be reliable indicators of groundwater conditions in areas that have experienced significant recent changes in hydrology. Additionally, in areas of fill, sufficient time may not have passed since fill placement for these indicators to develop. Not all hydric soils exhibit mottled and/or gleyed horizons. Their presence or absence alone should not dictate the interpretation of site groundwater conditions. Sources of groundwater table fluctuations As groundwater table levels and/or seepage rates are typically not static, it is anticipated that groundwater conditions will vary depending on local subsurface conditions, season, precipitation, changes in land use both on and off site and other factors. Markedly, we anticipate that groundwater conditions on site are largely influenced by seasonal variations of precipitation. Considerations GTS considers the depth at which groundwater seepage stabilizes and ponds to be the groundwater table. Groundwater seepage will influence stormwater management facilities and should be considered when designing those facilities. The groundwater conditions reported on the test pit logs are for the specific locations and dates indicated, and therefore may not necessarily be indicative of other locations and/or times. Please consider that groundwater table levels are generally higher (at shallower depths)during the wetter months (October through May). Our construction recommendations consider the groundwater conditions encountered at the time of our field investigation, in association with the project design provided at the time of this report. It is the clients and their (his/her) representative's responsibility to inform GTS of variations in groundwater conditions and/or any modifications to project designs so that a review of and revision to report recommendations can be made, if necessary. Unless specifically requested, GTS is not responsible to provide monitoring of groundwater conditions beyond the time of our site investigations. Please keep in mind that groundwater conditions may be different if there is a substantial lapse of time between submission of this report and the start of construction. If this is the situation, GTS recommends we be contacted to evaluate groundwater conditions in order to determine whether our report conclusions and recommendations remain applicable. RESULTS Stormwater Infiltration Potential Test Pit Gradation Results From the explorations excavated in the areas of interest, 13 representative soil samples were selected and mechanically tested for grain size distribution and calculation according to the 2012 Stormwater Management Manual for Western Washington Page 4 of 7 GeoTest Services, Inc. August 30,2017 2202 15I'Street,Anacortes,WA Job No. 17-0425 (SMMWW) amended December 2014, soil grain size analysis method, Section 3.3.6. A summary of these results are reproduced in Table 1 below. TABLE 1 Test Pit Soil Sample Infiltration Rates 0111111 Based on the 2012 SMMWW amended December 2014 Sample Design Infiltration Rate Test Pit Classification Geologic K...Uncorrected Rate ID Depth USCS Unit finches/Hour) Per ASTM D422 Simplified (ft) Approach(Inches/Hour) TP-1 1.0 SM Weathered TIII 9.30 1.51 TP-1 2.0 SP-SM Weathered Till 38.09 6.17 TP-1 4.5 SP-SM Weathered Till 48.08 7.79 TP-2 2.5 SM Weathered Till 9.26 1.50 TP-2 5.0 ML Glacial Till 2.24 0.36 TP-3 2.0 SM Weathered Till 11.71 1.90 TP-3 3.5 SP-SM Weathered Till 39.08 6.33 Notes: -Ksat=Initial Saturated Hydraulic Conductivity •Listed infiltration rates are estimated long-term(design)rates based on the soil grain size analysis method. -Correction Factors Used:CFv=0,70 In the simplified approach (Section 3.3.4) the infiltration rate is derived by applying appropriate correction factors to the measured saturated hydraulic conductivity (K ) from the ASTM 422 grain size analysis. Saturated hydraulic conductivity is a quantitative measure of a saturated soil's ability to transmit water when subjected to a hydraulic gradient. It can be thought of as the ease with which pores of a saturated soil permit water movement. Saturated Hydraulic Conductivity is expressed as follows: Log10(Ksat)= -1.57+ 1.90D10+ 0.015Dgo-0.013D90-2.08ffnes Where Dta, D6o, and D90 are the grain sizes in mm for which 10 percent, 60 percent, and 90 percent is more fine and fries is the fraction of the soil(by weight)that passes the U.S. No. 200 sieve. Ksat is measured in cm/sec. With this equation, we can determine the saturated hydraulic conductivity for our representative samples. See example below: Test Pit TP-1 at 1.0 foot BGS: [cat = 0.006562964 cm/sec or approximately 9.30 inches/hour. Applying correction factors for site variability (0.45), test method (0.4) and degree of influent control to prevent siltation and bio-buildup (0.9) gives a corrected long term design rate of 1.51 inches/hour for the example above. Based on the 2012 SMMWW(amended December 2014) soil grain size analysis method and our applied correction factors, the weathered glacial till soils located below the topsoil contains estimated long term design infiltration rates ranging between 7.79 and 1.50 in/hr Accordingly, we recommend using the lowest result value of 1.50 in/hr for use in design for the weathered glacial till. Page 5 of 7 GeoTest Services,Inc. August 30,2017 22021511'Street,Anacortes,WA Job No. 17-0425 Stormwater Pollutant Treatment The stormwater facilities on-site may require some form of pollutant pre-treatment or treatment with an amended soil prior to onsite infiltration or offsite discharge. It is our opinion, based on past experience, that the re-use of onsite topsoil and weathered Outwash Soils is often the most sustainable and cost effective method for pollutant treatment purposes. Cation exchange capacities, organic contents, and pH of site subsurface soils were determined to establish their pollutant treatment suitability. Cation Exchange Capacity, Organic Content and pH Testing Three composite samples were collected during our subsurface explorations for pollutant treatment purposes. Cation exchange capacity (CEC), organic content (LOI), and pH tests were performed by Northwest Agricultural Consultants. Laboratory test results are presented in Table 2. TAPLE Cation tai'eherige Capacity,'bitiankc atitfpH t tfatatox%Test Rifiiilibt Test Pit Sample Cation Exchange Capacity Organic Content H ID Depth(ft) (meg1100 grams) (off) p TP-1 1.5 11.8 6.34 5.6 TP-2 5.0 21.5 7.78 5.5 TP-3 3.5 6.1 3.65 6.8 Criteria SSC-6 states that cation exchange capacity must be greater than or equal to 5.0 meq/100 grams and organic content must be a minimum of 1.0 percent for treatment purposes. Based on the results listed in Table 2, the Topsoil and weathered glacial till appear to be suitable for onsite pollutant treatment purposes based on the SSC-6 of the 2012 Washington State Department of Ecology Stormwater Management Manual for Western Washington. Additional considerations to using infiltration as a treatment option include the soil infiltration rate/ drawdown time as described in SSC-4 of the 2012 Washington State Department of Ecology Stormwater Management Manual for Western Washington. A maximum drawdown time is applied to some types of infiltration based water quality design facilities. LIMITATIONS The scope of services for this report included stormwater infiltration only, this report is not intended to address other geotechnical concerns with regards to the planned building foundation support, settlement, potential seismic considerations such as liquefaction and/or other geologic hazards that may exist within this property. GeoTest can perform additional geotechnical evaluation and/or analysis, with regards to the above mentioned geotechnical items, upon request. The analyses, conclusions, and recommendations provided in this report are based on conditions encountered at the time of the subsurface exploration performed by GeoTest Services, Inc., information from previous studies and our experience and judgment. Our work has been performed in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing under similar Page 6 of 7 GeoTest Services,Inc. August 30,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 conditions in this area. GeoTest Services has prepared this report for the exclusive use of Landed Gentry Homes and Communities and their design representatives for specific application to the proposed new development located 2202 151" Street in Anacortes, Washington. No warranty, expressed or implied, is made. We must presume the subsurface conditions encountered are representative for the proposed site for the purposes of formulating our recommendations. However, you should be aware that subsurface conditions may vary with time and between exploratory locations, and unanticipated conditions may be encountered. If construction reveals differing conditions or the design is modified, we should be retained to reevaluate our recommendations and provide written confirmation or modification, as needed. We appreciate the opportunity to be of service to you on this project. If any questions should arise regarding this report, please contact the undersigned. Respectfully Submitted, GeoTest Services, Inc. 247 ivrefueg Golvst / 2420 0)// .led Gec> Tip , ttytla Tim Chylla, L.E.G. Engineering Geologist Attachments Figure 1 Vicinity Map Figure 2 Site and Exploration Plan Figure 3 Soil Classification System and Key Figures 4-5 Logs of Test Pits Figures 6-7 Grain Size Distribution Northwest Agricultural Results(1 page) ASFE-Report Limitations and Guidelines For Its Use(3 pages) References Interactive Geologic Map of Washington State. Online interactive services provided by the Washington State Department of Natural Resources. Washington State Department of Ecology, 2012 (amended December 2014). Stormwater Management Manual for Western Washington. Page 7 of 7 PROJECT LOCATION :,1': n rt I ` a 1 :u . v 'ill''St ! '1,'SI R• I' 3. •• I' t •'lt',41 Gap Sante Par 17 ) i•l'i.,: ill , ti I R 1 .. .IV)ct 1. x r- ; C, 1 d 'i 4-1 u ,i a, c <• ' > p E- .# . .lilt,c+ +m Vc,lunteer Par; v+ it F' ,~ t13 . t '-- r' `� •-7. ,J 'Anacortes•MerIna :,, m 1 r l- .p Cranberry, t , N Ana(ollc�. Lake Perk , U, ?au, . r..c X Alriloi l a�ettt'S` Y r , I 'i ,1 '!' '1.. ry 4 ?il,i' �, • ,'.h �1 , ,, ...„., w.,....s .. . 1. iiii:....,„:4..,7, „.,,- tz S 3C d 1 !- {1, r Ifit MAP REFERENCED FROM GOOGLE MAPS t Date: 8-30-17 By: JS Scale: As Shown Project t3EOTEST SERVICES, INC. VICINITY MAP 17-0425 741 Marine Drive Bellingham, WA 98225 PADILLA, ADU Figure phone: (360)733-7318 2202 15TH STREET fax: (360) 733-7418 ANACORTES, WASHINGTON I PROJECT LOCATION f ;, t ! ' r� 1 i r % PI • . ti r > TP-3 < m • a m i b - K - ffiiii i TP-2 1 15th Street o - • • MAP REFERENCED FROM GOOGLE MAPS As TP-#=Approximate Test Pit Location N Date:8-30-17 By: JS Scale: As Shown Project GEOTEST SERVICES, INC. SITE AND EXPLORATION PLAN 17-0425 741 Marine Drive Bellingham, WA 98225 PADILLA ADU Figure phone: (360)733-7318 220215TH STREET fax: (360)733-7418 ANACORTES,WASHINGTON 2 _. -- . - — _ - -._____. ..._ - - Scil Classification System usos PSIAJOU GRAPHIC LETTER TYPICAL DMSIONS SYMBOL SYMBOL DESCRIPTIONSt91t2► GRAVEL AND CLEAN GRAVEL 0b.°�o.0.ti. GIN. Well-graded gravel;gravel/sand mixture(s); little or no fines „,�, GRAVELLY SOIL (Little or no fines) o o b°o G Poorly graded gravel;gravel/sand mixture(s);little or no fines Q c�c 14 o O .O.•CO . (More than ref 1of n GRAVEL WITH FINES , ' �.' GM Silty gravel; gravel/sand/sitt mixture(s) coarse fraction retained W E g on No.4 sieve) (Appreciable amount of IS N __ — ^_ _ fines) ,A •• •- tf (; Clayey gravel;gravel/sand/day mixtures) Ca2o w c SAND AND CLEAN SAND SWWell-graded sand; gravelly sand;little or no fines u7 .c 2 SANDY SOIL (Little or no fines) c� rtm a� — SP Poorly graded sand;gravelly sand; little or no fines O 1.32 (More than 50%of r 1 t a v v coarse fraction passed SAND WITH FINES .` ` �M Silty sand; sand/silt mixture(s) through No.4 sieve) (Appreciable amount of fines) • SC Clayey sand;sand/day mixture(s) • Inorganic silt and very fine sand; rock flour; silty or clayey fine -r a°>i SILT AND CLAY ML sand or clayey silt with slight plasticity p o CL Inorganic day of low to medium plasticity;gravelly day; sandy E o ` N W (Liquid limit less than 50) ( clay; silty day;lean day ° S Off„ Organic silt;organic,silty day of low plasticity Z a Z a) O C N 2 - �'0 0 SILT AND CLAY I I I15JC Inorganic silt; micaceous or diatomaceous fine sand z o E (Liquid limit greater than 50) _ OH Inorganic day of high plasticity;fat clay `" OH Organic day of medium to high plasticity; organic silt HIGHLY ORGANIC SOIL PT Peat; humus;swamp soil with high organic content GRAPHIC LETTER OTHER MATERIALS SYMBOL SYMBOL T Yk-"VCAL DESCROPTIONIS PAVEMENT AC or PC Asphalt concrete pavement or Portland cement pavement ROCK RK Rock(See Rock Classification) WOOD 'ND Wood, lumber,wood chips — DEBRIS 0 0 OE$ Construction debris, garbage /n n ri , Notes: 1. Soil descriptions are based on the general approach presented in the Standard Practice forDescnption and Identification of Soils(Visual-Manual Procedure), as outlined in ASTM D 2488.Where laboratory index testing has been conducted, soil classifications are based on the Standard Test Method for Classification of Soils for Engineering Purposes, as outlined in ASTM D 2487. 2. Soil description terminology is based on visual estimates(in the absence of laboratory test data)of the percentages of each soil type and is defined as follows: Primary Constituent: >50%-"GRAVEL,""SAND,""SILT,""CLAY,"etc. Secondary Constituents: >30%and<50%-"very gravelly,""very sandy,""very silty,"etc. > 12%and<30%-"gravelly,""sandy,""silty,"etc. Additional Constituents: > 5%and<12%-"slightly gravelly,""slightly sandy,""slightly silty,"etc. < 5%-"trace gravel,""trace sand,""trace silt,"etc., or not noted. j Drilling and Sampling Key Field and Lab Test Data SAMPLE NUMBER& INTERVAL SAMPLER TYPE Code Description Code Description Sample Identification Number a 3.25 inch O.D.,2.42-inch I.D. Split Spoon PP=1.0 Pocket Penetrometer,tsf b 2.00-inch Q.D., 1.50-inch I.D. Split Spoon TV=0.5 Torvane,tel Recovery Depth Interval c Shelby Tuba PID=100 Photoionization Detector VOC screening, ppm 1 J — Sampl©Depth Interval d Grab Sample W=10 Moisture Content, % ik J e Other-See text if applicable D= 120 Dry Density, pcf Portion of Sample Retained 1 300-lb Hammer,30-inch Drop -200=60 Material smaller than No.200 sieve, % for Archive or Analysis 2 140-lb Hammer,30-inch Drop GS Grain Size-See separate figure for data 3 Pushed AL Atterberg Limits-See separate figure for data 4 Other-See text if applicable GT Other Geotechnical Testing Groundwater CA Chemical Analysis 7 Approximate water elevation at time of drilling(ATD) or on date noted. Groundwater i ATD levels can fluctuate due to precipitation, seasonal conditions, and other factors, --- -- - ____ `adilla Adu ----I� Figure I, ,( It ( )` ii ( I 2202 15th Street Soil Classification System and Key 3 Anacortes, Washington IP4 'AAMPLE DATA SOIL PROFIL . UNDWA EFL °©' w o Tracked Excavator E ca. E sa Excavation Method: E L ; m , cn E aa) a� Ground Elevation (ft): Unknown a- E c E V) e 0 od Cl) I- Ch 0 55 _5. OL Sofl, brown,moist,organic SILT(Topsoil) i I I d I SM Loose to medium dense,brown, moist, very silty _ -i 2 I T d GS to silty,fine SAND(Weathered Till) 1 -2 1-3_7 L d GS sift content decreases, becomes coarse to fine SAND i9 oi—_i 1- �- i-ii_I I_ d GS I- n i-a d ML stiff to hard, moist, bluish gray, sandySILT Slight 'r- �_ --f Very9 K with pebbles and cobbles(Glacial Till) I --k3 tr) _ < the I- d II o —8 Test Pit Completed 06/27/17 Total Depth of Test Pit=7.5 ft. .J - O _4 1 10 — O Q a_ La TP2 0/ I SAi;WfP't»E: DATA SOIL PROFILE GROUNDWATER ii ° Excavation Method: tracked Excavator E D 1A >. m co , cn Ground Elevation (fit): Unknown -, o - cz a> a 0 a [) ~- u a Cl) T rn (1)ots U) l� 0 w 0 {3 < OL Loose, brown,dry,slightly silty,fine sand with J-1_.C d organics(Topsoil) z I ( SM Loose to medium dense, brown,moist,very silty 1 F.o �_ 1I__ to silty,fine SAND with organics(Fill) 2 2 J _ Cl GS SM Loose to medium dense, brown,moist,very silty J _ to silty,fine SAND(Weathered Till) u z �� 1 -I ML Very stiff to hard,moist, bluish gray,sandy SILT Q Slight —i • f with pebbles and cobbles(Glacial Till) o - N - 2.3 1 I d GS r- ✓ —6 — iLi it 0. _. d _ 2-4f d — o _8 _I Test Pit Completed 06/27/17 ow, Total Depth of Test Pit=7.5 ft. U -- _ Cr) - r-; w —10 -- Oli a 6 Notes: 1. Stratigraphic contacts are based on field interpretations and are approximate. 2. Reference to the text of this report is necessary for a proper understanding of subsurface conditions. O 3. Refer to"Soil Classification System and Key"figure for explanation of graphics and symbols. ia Padilla Adu Figure - ^G� � 11 2202 15th Street Log of That Pits 4 Anacortes, Washington (1 of 2) SAMPLE DATA SOIL PROFILE GROUNDWP`'u istri n Tracked Excavator Excavation Method: a E ocsv cn Ground Elevation (ft): Unknown a a> cb 0 c c4 0) m c E ft) ai cv ❑ co 06 CO SM Stiff,brown, moist, silty, medium to fine SAND 3-1 ]4 d GS with gravel and cobbles(Fill) OL Soft, black to brown, moist, organic SILT(Relic 2 3-21 -1_ d GS SM \Topsoil) Loose to medium dense, brown,moist,very silty ✓ - to silty,fine SAND(Weathered Till) 9 3-'31 I d silt content decreased silt content increased • - O 6 3A PT cl V Slight n ML Very stiff to hard, moist, bluish gray,sandy SILT g J with pebbles and cobbles(Glacial Tit) 3 — Test Pit Completed 06/27/17 a Total Depth of Test Pit=7.5 ft. n S 1n — N 8 >- F- UCD 0I W 0 dzc{ 0 H Lu 2 z 0 H I-. LL Z 3 fu 0 N f f Ca ui a CL' C1. O i O ILI L) U) L) LLI 0 d 4 0 Notes: 1. Stratigraphic contacts are based on field interpretations and are approximate. 2. Reference to the text of this report is necessary for a proper understanding of subsurface conditions, 3. Refer to"Soil Classification System and Key"figure for explanation of graphics and symbols. ti Padilla Adu Figure c7eo-reST 2202 15th Street Log of Test Pits 5 Anacortes, Washington (2 of 2) U.S. SIEVE OPENING IN INCHES I U.S.SIEVE NUMBERS I HYDROMETER II 6 4 3 2 1 5 1 3 4 112, 3 6 810 1416 20 30 40 50 60 100 140 200 ~I I 9 J ` 0 Ilk _ --_, _-- -80 - _ _i_______ mix,,, 1 l 70 - - - UJ - a = •3 60 w Ul A c50 - - -•-r- 4 i 0 -. C7 8 �-- a d40 I <( d- S 30 - f ---- J2 o 1 !1 20 --- -- -- u, ,-.1d T, 10 - - - - ,,- - - ,_ a0 = _ - - -- --- - �- 0 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters in z F Gravel Sand nCobbles coarse tine coarse medium 1 fine Silt or Clay W o Point Depth Classification LL PL PI Cc Cu ',r ' TP-1 1.0 Silty, fine SAND (SM) I1 TP-1 2.0 Slightly silty, fine SAND (SP--SM) 1.43 2.42 o c A TP-1 4.5 Slightly silty, coarse to fine SAND with trace gravel (SP-SM) 1.52 5.35 :'a• TP-2 2.0 Silty, medium to fine SAND with trace gravel (SM) r O TP-2 5.0 Very sandy SILT (MI-) o W Point Depth p U [� D %Coarse % °Io Coar Fine se ' o Medium %Fine a p 100 60 50 30 Io Gravel Gravel Sand Sand Sand %Fines o • TP-1 1.0 4.75 0.168 0.137 0.076 0.0 0.0 0.6 4.5 65.5 29.4 IM TP-1 2.0 9.5 0.197 0.181 0.152 0.081 0.0 0.1 0.2 0.7 91.6 7.4 `� ttk TP-1 4.5 19 0.776 0.632 0.414 0.145 0.0 5.3 9.1 54.8 23.7 7.1 sx- TP-2 2,0 37.5 0.258 0.191 0.084 5.8 2.9 3.8 16.1 43.5 27.8 o O TP-2 5.0 9.5 0.079 0.0 0.7 1.4 8.1 30.8 59.0 or (,) Cc = D3o'/(D6o* DO To be well graded: 1 < Cc < 3 and Gt, - D60/D10 Cu > 4 for GVV or C„ > 6 for SW (73 Padilla P�du - - -- _ -� - Figure ceoTeT 2202 1 5th street Grain Size Test Data 6 Anacortes, Washington . . . .U.S. SIEVE OPENING IN INCHES I U.S.SIEVE NUMBERS I HYDROMETER 4 2 1 - 1/2 3 6 10 16 30 50 100 200 6 3 1.5 1 it„.41.7.4il3 14 .8,20 40m 60 140 100— I - L F _, \‘\ i--• I — 90 r — — t)i 80 ' I 70 — r — , I ek* 01 ---.--- . 1- -.,-- .11: .0 • --,-' 1 Lif Q _ — I 7- 2 50 1 , . O U- O 0 :1 1— ° 4)40 , J . E < a • n 30 . a < '. I - - fTh `--, 20 a. I . Li-, c,, ...t 1- - . • • , w . . o . • • • . • 0 0 • • • w a 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters ) 6' Gravel Sand 4 Cobbles d Silt or Clay i= coarse fine coarse medium fine Li) w 1 6 Point Depth Classification LL PL PI C, Cu P 0 TP-3 2.0 Silty, fine SAND (SM) -I--: lX1 TP-3 3.5 Slightly silty, coarse to fine SAND with trace gravel (SP-SM) 1.05 4.58 -.,-- til Cy 47 (/) I-- — () 111 6 %Coarse %rine %Coarse %Medium V.I-Ine Point Depth Dioo D60 D50 D30 D10 Gravel Gravel Sand Sand Sand Jo Fines f Y _ Ccil:, 0 TP-3 2.0 9.5 0.182 0.158 0.089 0.0 0.0 0.2 2.6 72.6 24.6 RI TP-3 3.5 19 0.499 0.367 0.239 0.109 0.0 9.5 9.4 24.1 50.0 7.0 b w 0 u)• 1-- III ? IA i C c = D02/(D60' D.10) To be well graded: 1 < Cc < 3 and --6- CL, > 4 for GW or Cu > 6 for SW Padilla Adu Figure oeoTe ST 2202 15th Street Grain Size Test Data I Anacortes, Washington Northwest Agricu'itura I GeoTest Services Inc. . COI1Su{tar 741 Marine Drive Bellingham, WA 98225 2545 W Falls Avenue PAP-Accredited Kennewick,WA 99336 509.783.7450 Report:41439-1 www.nwag.com lab@nwag.com NAPT Date:June 30,2017 Project No: 17-0425 Project Name: Padilla Adu Sample ID pH Organic Matter Cation Exchange Capacity TP-1 @ 1.5' 5.6 6.34% 11.8 meq/100g TP-2 @ 5.0' 5.5 7.78% 21.5 meq/100g TP-3 @ 3.5' 6.8 3.65% 6.1 meq/100g Method SM 4500-H+B ASTM D2974 EPA 9081 REPORT LIMITATIONS AND GUIDELINES FOR ITS USE1 Subsurface issues may cause construction delays, cost overruns, claims, and disputes. While you cannot eliminate all such risks, you can manage them. The following information is provided to help: Geotechnical Services are Performed for Specific Purposes, Persons, and Projects At GeoTest our geotechnical engineers and geologists structure their services to meet specific needs of our clients. A geotechnical engineering study conducted for a civil engineer may not fulfill the needs of an owner, a construction contractor or even another civil engineer. Because each geotechnical engineering study is unique, each geotechnical engineering report is unique, prepared solely for the client. No one except you should rely on your geotechnical engineer who prepared it. And no one—not even you—should apply the report for any purpose or project except the one originally contemplated. Read the Full Report Serious problems have occurred because those relying on a geotechnical engineering report did not read it all. Do not rely on an executive summary. Do not read selected elements only. A Geotechnical Engineering Report is Based on a Unique Set of Project-Specific Factors GeoTest's geotechnical engineers consider a number of unique, project-specific factors when establishing the scope of a study. Typical factors include: the clients goals, objectives, and risk management preferences; the general nature of the structure involved its size, and configuration; the location of the structure on the site; and other planned or existing site improvements, such as access roads, parking lots, and underground utilities. Unless GeoTest, who conducted the study specifically states otherwise, do not rely on a geotechnical engineering report that was: • not prepared for you, • not prepared for your project, • not prepared for the specific site explored, or • completed before important project changes were made. Typical changes that can erode the reliability of an existing geotechnical engineering report include those that affect: • the function of the proposed structure, as when it's changed, for example, from a parking garage to an office building, or from a light industrial plant to a refrigerated warehouse, • elevation, configuration, location, orientation, or weight of the proposed construction, • alterations in drainage designs; or • composition of the design team; the passage of time; man-made alterations and construction whether on or adjacent to the site; or by natural alterations and events, such as floods, earthquakes or groundwater fluctuations; or project ownership. Always inform GeoTest's geotechnical engineer of project changes — even minor ones — and request an assessment of their impact. Geotechnical engineers cannot accept responsibility or liability for problems that occur because their reports do not consider developments of which they were not informed. 'Information in this document is based upon material developed by ASFE,Professional Firms Practicing in the Geosciences(asfe.org) o�eoTe it Subsurface Conditions Can Change This geotechnical or geologic report is based on conditions that existed at the time the study was performed. Do not rely on the findings and conclusions of this report, whose adequacy may have been affected by: the passage of time; by man-made events, such as construction on or adjacent to the site; or by natural events, such as floods, earthquakes, or groundwater fluctuations. Always contact GeoTest before applying the report to determine if it is still relevant. A minor amount of additional testing or analysis will help determine if the report remains applicable. Most Geotechnical and Geologic Findings are Professional Opinions Our site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoTest's engineers and geologists review field and laboratory data and then apply their professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ—sometimes significantly—from those indicated in your report. Retaining GeoTest who developed this report to provide construction observation is the most effective method of managing the risks associated with anticipated or unanticipated conditions. A Report's Recommendations are Not Final Do not over-rely on the construction recommendations included in this report. Those recommendations are not final, because geotechnical engineers or geologists develop them principally from judgment and opinion. GeoTest's geotechnical engineers or geologists can finalize their recommendations only by observing actual subsurface conditions revealed during construction. GeoTest cannot assume responsibility or liability for the report's recommendations if our firm does not perform the construction observation. A Geotechnical Engineering or Geologic Report may be Subject to Misinterpretation Misinterpretation of this report by other design team members can result in costly problems. Lower that risk by having GeoTest confer with appropriate members of the design team after submitting the report. Also, we suggest retaining GeoTest to review pertinent elements of the design teams plans and specifications. Contractors can also misinterpret a geotechnical engineering report. Reduce that risk by having GeoTest participate in pre-bid and preconstruction conferences, and by providing construction observation. Do not Redraw the Exploration Logs Our geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors of omissions, the logs included in this report should never be redrawn for inclusion in architectural or other design drawings. Only photographic or electronic reproduction is acceptable; but recognizes that separating logs from the report can elevate risk. Give Contractors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnical engineering report, but preface it with a clearly written letter of transmittal. In that letter, consider advising the contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited; encourage them to confer with the GeoTest and/or to conduct 'Information in this document is based upon material developed by ASFE,Professional Firms Practicing in the Geosclences(aste.org) oeore5r additional study to obtain the specific types of intormation they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might you be in a position to give contractors the best information available, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. In addition, it is recommended that a contingency for unanticipated conditions be included in your project budget and schedule. Read Responsibility Provisions Closely Some clients, design professionals, and contractors do not recognize that geotechnical engineering or geology is far less exact than other engineering disciplines. This lack of understanding can create unrealistic expectations that can lead to disappointments, claims, and disputes. To help reduce risk, GeoTest includes an explanatory limitations section in our reports. Read these provisions closely. Ask questions and we encourage our clients or their representative to contact our office if you are unclear as to how these provisions apply to your project. Environmental Concerns Are Not Covered in this Geotechnical or Geologic Report The equipment, techniques, and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated containments, etc. If you have not yet obtained your own environmental information, ask your geotechnical consultant for risk management guidance. Do not rely on environmental report prepared for some one else. Obtain Professional Assistance to Deal with Biological Pollutants Diverse strategies can be applied during building design, construction, operation, and maintenance to prevent significant amounts biological pollutants from growing on indoor surfaces. Biological pollutants includes but is not limited to molds, fungi, spores, bacteria and viruses. To be effective, all such strategies should be devised for the express purpose of prevention, integrated into a comprehensive plan, and executed with diligent oversight by a professional biological pollutant prevention consultant. Because just a small amount of water or moisture can lead to the development of severe biological infestations, a number of prevention strategies focus on keeping building surfaces dry. While groundwater, water infiltration, and similar issues may have been addressed as part of this study, the geotechnical engineer or geologist in charge of this project is not a biological pollutant prevention consultant; none of the services preformed in connection with this geotechnical engineering or geological study were designed or conducted for the purpose of preventing biological infestations. 'Information in this document is based upon material developed by ASFE,Professional Firms Practicing In the Geosciences(asfe.org) oeoTe5T HOUSE-WWHM VIEWS AND REPORT 1 VW4,9 M3 ww lral-:ousel _ e Edit View 1-ie7p --- re a ITTw.._._____ __ww.u.-__-.�-•--�-_ --__-..._-_ _ _. --R .r- 4 1.1) LIMN _ °� i BaWt 1I cievel feu SCENARIOS - .1 —.1 ( Subbasin Name_ ;Sewn 1 r Prede:relopIeoflj --� Surface BntertlQw — Groundwater Flows To �kg r Mitigated `i --- — — ---- S Area in Basin R.•Show Only Selected RunScenerro ! °j Available Pervious Available Impervious F!FMFNT'R 'co- C Forest Flat f.077 ;v ROOFTOPS/FLAT i ;0 eiND !--- ., Mk ' . i ', , , aiiiiiis it -,EDL.--=',IL 1 DE II {' :„ -I r•: Move Elements 1; 1 PerviousTota 0 077 Acres Impervious Total Ep Actes _ Basin Total 10 077._. ....-_.-_I Acres v , Save xyj Load xy# .._ :�2— .....:J Deselect Zero Select By" GO 9/27/2017 3:17 Phut • 1-1-7111 illi- 11 11117.4C7-7-'"w3 . P1 i I WW1-1M3 wwhni3-ouse2 i3e Etil: V et',.,' He; .... _ - ib -"'-'- 1 ihk- MN j clus l&r.;444.4.11NEP : z ir) 1- -t- -.., Basin 3_ilktigated SCENARIOS I - I ---• Subbasin Name. 'B _I asin 1 --: r Designate as Bypass for POC A.... - _ r Predeveloped Surface Interflow Groundwater Flows To : rGravel Trench Bed 1 i1Grayel Trench Bed 1 i _____ , - Area in Basin W Show Only Selected Run...„_ Scenario. ... Available Pervious Available Impervious .._... ___ Fl FMFNTS l;‘, C,Forest Fla _ t it) ;v7 .ROOFTOPS FLAT ! ',077. il Fig M MINIM 01111111111 6,..".10 Fill II - -71irg d toste Elements , 41 ..., PerviousTote. 10 Acres Impervious Totti 10 077 Acres-- -r- , __ _ . ___ Basin Total 10.077 Acres - S'ave x.y i Load xy• - --....---....1 a I : -1' '..-...1'" .":-- ----J ._ . . . Y 18 1 — Deselect Zero Select BY: GO _ _ 1 Ofj1 lirliro la Tlirir p 3 Prii" . 3 1 1 II V • ii• -1 1 WW443 WVrhm3Houre2` ire :dst rie°.<< ?oc.. - io,e Li.....r .......,_ 4,0„, 1 h MI,- !t __ .._ _ Chettlatic i.! _ - - SCENARIOS 1 - 1. Facility Name Gravel Trench Bed 1 I i .! Al- Predeveioped i' --• Outlet I Outlet 2 Outlet 3 t Downstream Connection {{0 ' 10 0 Zire '` =- • 1} Facility Type Gravel Trench/Bed .1 i — i l ' ' .Precipitation Applied to Facility Quick Trench j Run Scenario iI -- FI FM FNTt', e ; Evaporaiion A.REliea to FacilV 11 I"Facility Bottom Elevation (ft) > i ;i Facility Dimensions Outlet Structure Trench Length 46 El Will:4T: r - Riser Height(#t) 2 :�! i Trench Bottom U+Idth 2 ■+�l� 1 1 Effective Total Depth 3 - Riser Diameter(in) 112 -----i PI El wL 1 - Riser Type ;Flat :1 Ili i Bottom slope of Trench A.000001 Da 'I Left Side Slope ;0 Notch Type 1 Right Side Slope ;0 Material Layers for Trench/Bed 1 Layer 1 Thickness(ft) ;2 Orifice Diameter Height QMax iI 1 Layer 1 porosity 033 Number (In) (Ft) (cfs) Layer Z Thickness(ft)I .p 1 {a--------_,-;-1 _-`1 0 ._1 0 } Layer 2 porosity :0 2 ;o _i i i0 -,; 1 0 ! Layer 3 Thickness(ft) ?0 3 3�:,{ ;0 " i 0 ! Layer 3 porosity '0 i ' Infiltration YES --, Trench Volume at Riser Head(acre-ft) .001 Move Element: — Measured Infiltration Rate(in/hr) s5�3 "" _j Pond Increment 10,10 =1 41 AO! !� — Show Pond Table operiTable -_ Infiltration Reduction Factor(infilefactor) ;1� �► it Use Wetted Surface Area(sidewalls) +,l7E5 - ._r._, -.. il Total Volume Infiltrated(acre-ft) 6.807 Total Volume Through Facility(acre-it) 6 807 Save xy Load xv i �' - �_.. .. 1 __j 1 Total Volume Through Riser(acre-it) 0.001 Percent Infiltrated 100 _1 Y2 . _._�:J -i bfil0s : W3 .1_ Pal g Western Washington Hydrology Model PROJECT REPORT Project Name: wwhm3House2 Site Address: City Report Date : 9/27/2017 Gage Burlington Data Start : 1948/10/01 Data End 1999/09/30 Precip Scale: 0 . 83 WWHM3 Version: PREDEVELOPED LAND USE Name Basin 1 Bypass: No GroundWater: No Pervious Land Use Acres C, Forest, Flat . 077 Impervious Land Use Acres Element Flows To: Surface Interflow Groundwater Name Basin 1 Bypass : No Groundwater: No Pervious Land Use Acres Impervious Land Use Acres ROOF TOPS FLAT 0 . 077 Element Flows To; Surface Interflow Groundwater Gravel Trench Bed 1, Gravel Trench Bed 1, Name Gravel Trench Bed 1 Bottom Length: 46ft . Bottom Width : 2ft . Trench bottom slope 1: 0.000001 To 1 Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer : 2 Pour Space of material for first layer : 0.33 Material thickness of second layer : 0 Pour Space of material for second layer : 0 Material thickness of third layer : 0 Pour Space of material for third layer : 0 Infiltration On Infiltration rate : 6.33 Infiltration saftey factor : 1 Wetted surface area On Discharge Structure Riser Height: 2 ft. Riser Diameter: 12 in. Element Flows To: Outlet 1 Outlet 2 Gravel Trench Bed Hydraulic Table Stage(ft) Area(acr) Volume(acr-ft) Dechrg(cfa) Infilt(cfs) 0.000 0.002 0.000 0.000 0.000 0.033 0.002 0.000 0.000 0.014 0.067 0.002 0.000 0.000 0.014 0.100 0.002 0.000 0.000 0.015 0.133 0.002 0.000 0.000 0.015 0.167 0.002 0.000 0.000 0.016 0.200 0.002 0.000 0.000 0.016 0.233 0.002 0.000 0.000 0.017 0.267 0.002 0.000 0.000 0.017 0.300 0.002 0.000 0.000 0.018 0.333 0.002 0.000 0.000 0.018 0.367 0.002 0.000 0.000 0.019 0.400 0.002 0.000 0.000 0.019 0.433 0. 002 0.000 0.000 0.020 0.467 0.002 0.000 0.000 0.020 0.500 0.002 0.000 0.000 0.021 0.533 0.002 0.000 0.000 0.021 0.567 0.002 0.000 0.000 0.021 0.600 0.002 0.000 0.000 0.022 0.633 0.002 0.000 0.000 0.022 0.667 0.002 0.000 0.000 0.023 0.700 0.002 0.000 0.000 0.023 0.733 0.002 0.001 0.000 0.024 0.767 0.002 0.001 0.000 0.024 0.800 0.002 0.001 0.000 0.025 0.833 0.002 0.001 0.000 0.025 0.867 0.002 0.001 0. 000 0.026 0.900 0.002 0.001 0.000 0.026 0.933 0. 002 0.001 0.000 0.027 0.967 0.002 0.001 0.000 0.027 1.000 0.002 0.001 0.000 0.028 1.033 0.002 0.001 0.000 0.028 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N 1-, I-' F-, I-, I--' ' 1 , f ' H F- F-' F--' 1-, 1-, F I--'• F-' F-, 1-, I-, }-i F h+ 1-1 CO l0 CO 0 CO J -J -] 01 01 01 Cn Cn 01 as- CO CO W N N) N N F-1 F CD G O C0 cc) OJ Co CO -7 -1 J 01 01 61 Cn Cn Cn az. az. CJ W W N) N N CA) O 0 W 0 01 CO O C1 W O 01 CO 0 01 CO O 01 CO O 01 CO O 01 CO O 01 CO O 01 CO O 01 CO CD 01 CO 0 01 CO O 01 CO O 01 W O 0 W O 01 CO 0 01 CO O 01 W O `.1 CO O -.7 W O J W O -.1 Co O -1 Co O W O J Co O J W O J W O J CO O J CO O i W O W O J Co O J CO O J W o W 0 -.] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 N N) N N N) N) N) N) N N) N) Ni N.) N) N) N N) N N N) N N N) N) N N N) N N) N.) N) N N) N) N N N N N N N N N) N) N N) N) N N) N) N) N) N) N) N) N) N) O O O O o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C O 0 G 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C 0 O O 0 0 O O 0000000000000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 W W W W W W W W W CO W W W N N N N) N N N) N N.) N) N N N N CO CO 01 dl Cn Cn A 4:=. CO CO CO N N N 1--` F--` 0 0 0 0 0 0 O 0 0 0 0 0 0 0 0 0 0 0 0 O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 W CO Cn N J W l0 Cn F ' a, N -.1 F-' CO 61 W 0 CO 01 W 0 0 0 0 0 O 0 O 0 O O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 G O Co 1-, Cn 0 61 0 0 0 N Cn l0 az. O Ql -.1 CS) J O 01 07 O o 0 0 0 0 0 0 0 0 0 0 0 0 O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 N Cn CO LO LO CO M ai F L d1 W W 01 CO a� CO HA W a, CO CO LC) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 G O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 G 0 Cn Cn Cn CSI Cn Cn Cn Cn 01 cn to CSi CO CO CO W W CO W W W W W CA) W LA) Co W W W W W W N N N Cn a� CO W N) N 1-, F-, 11 0 O LO CO O O 01 01 Cn Cn a, P W Co W N ICJ F-A HA O O l0 LO CO CO -i J 61 6) 61 Cn Cn P az, W W N N HA I-, O O L0 l0 CO 2.967 0.002 0. 003 9.256 0.055 3.000 0.002 0.004 9.739 0.056 MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.000768 5 year 0.001605 10 year 0.002242 25 year 0.003085 50 year 0.00372 100 year 0.004346 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.003 0.000 1951 0.002 0. 000 1952 0.001 0. 000 1953 0.001 0. 000 1954 0.000 0. 000 1955 0.007. 0.000 1956 0.001 0.000 1957 0.001 0.000 1958 0.007. 0.000 1959 0.001 0.000 1960 0.002 0.000 1961 0.001 0.000 1962 0.000 0.000 1963 0.000 0.000 1964 0.000 0.000 1965 0.001 0.000 1966 0.001 0.003 1967 0.000 0.000 1968 0.001 0.000 1969 0.002 0.000 1970 0.000 0. 000 1971 0.000 0.000 1972 0.002 0.000 1973 0.001 0.000 1974 0.000 0.000 1975 0.002 0.000 1976 0.007 0.000 1977 0.000 0.000 1978 0.000 0.000 1979 0.001 0.000 1980 0.000 0.000 1981 0.001 0.000 1982 0.001 0.000 1983 0.002 0.000 1984 0.001 0.000 1985 0.002 0.000 1986 0.000 0.000 1987 0.001 0.000 1988 0.001 0.000 1989 0.002 0.000 1990 0.001 0.000 1991 0.001 0.000 1992 0.002 0.000 1993 0.001 0.000 1994 0.001 0.000 1995 0.000 0.000 1996 0.000 0.000 1997 0.001 0.000 1998 0.003 0.000 1999 0.001 0.000 2000 0.000 0.000 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0067 0.0034 2 0.0029 0.0000 3 0.0029 0.0000 4 0.0024 0.0000 5 0.0020 0.0000 6 0. 0020 0.0000 7 0. 0019 0.0000 8 0. 0017 0.0000 9 0.0017 0.0000 10 0.0016 0.0000 11 0.0016 0.0000 12 0.0015 0.0000 13 0.0013 0.0000 14 0.0012 0.0000 15 0.0012 0.0000 16 0.0012 0.0000 17 0.0012 0.0000 18 0.0009 0.0000 19 0.0009 0.0000 20 0.0009 0.0000 21 0.0009 0.0000 22 0.0008 0.0000 23 0.0008 0.0000 24 0.0008 0.0000 25 0.0008 0.0000 26 0.0007 0.0000 27 0.0007 0.0000 28 0.0007 0.0000 29 0. 0007 0.0000 30 0.0007 0.0000 31 0.0007 0.0000 32 0.0006 0.0000 33 0.0005 0.0000 34 0.0005 0.0000 35 0.0005 0.0000 36 0.0005 0.0000 37 0.0005 0.0000 38 0.0004 0.0000 39 0.0004 0.0000 40 0.0004 0.0000 41 0.0004 0.0000 42 0.0004 0.0000 43 0.0004 0.0000 44 0.0004 0.0000 45 0.0003 0.0000 46 0.0002 0.0000 47 0.0002 0.0000 48 0.0002 0. 0000 49 0.0001 0.0000 50 0.0001 0.0000 51 0.0000 0.0000 POC #1 The Facility PASSED The Facility F'rt> ;LUU Flow(CFS) Predev Dev Percentage Pass/Fail 0.0004 4506 2 0 Pass 0.0004 3950 2 0 Pass 0.0005 3462 2 0 Pass 0.0005 3051 2 0 Pass 0.0005 2725 2 0 Pass 0.0006 2449 2 0 Pass 0.0006 2210 2 0 Pass 0.0006 2002 2 0 Pass 0.0007 1814 2 0 Pass 0.0007 1645 2 0 Pass 0.0007 1495 2 0 Pass 0.0008 1364 2 0 Pass 0.0008 1238 2 0 Pass 0.0008 1111 2 0 Pass 0.0009 1025 2 0 Pass 0.0009 926 2 0 Pass 0.0009 854 2 0 Pass 0.0010 794 2 0 Pass 0.0010 744 2 0 Pass 0.0010 695 2 0 Pass 0.0011 643 2 0 Pass 0.0011 601 2 0 Pass 0.0011 554 2 0 Pass 0.0012 509 2 0 Pass 0.0012 475 2 0 Pass 0.0012 438 2 0 Pass cr) Cn CA U) U) U) CO CO to CI) U) U) V) CO CO V) V) m CO U) m CO CO CO V) CO (fl U) CO U) II) CO U) CO Ih CO CO CO In U) ro ro ro ro ro ro m ro CS fa ro ro ro ro ro ro ro ro ro ro ro ro al ro ro ro ro ro ro m RI ro ro ro m ro ro ro ro ro ro ro ro rt ro ro ro ro ro ro ro (CI ro (If MS rci ro a a a a w a a a a a a a 04 a a a a a a a a a a a a a a a a a w a a a, a a a a a a a a a a a a a a a a a a, Cu a a a O4 0 0 O 0 0 0 0 0 O r-I ri r { r-I c-I c-i c-I c-I 1--I c-I N N N N N N N N N N N N N M M ( ) M M M Cr) Cr) Qc LI) LC) in in LO LC) LC) lf) N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N r-1 c--1 CZ) Cr) C-- Cc) Cs- 0 0 CO N Co r-I r i .44 00 Cr) 4,0 N LO 0 r- cf+ N O M I` mot' N O co E~ lf) I C) M N N c-I c-i O O yr O CA LO lQ N CO ti) N 61 I1 v' O O CO k Qc Cr) c-i O CO C` LO Cr) Cr) rI CSl Cr 00 00 CO �r M M M M N N N N N c-I ri I-1 I-I r-I ri c-I ri c--I c-I c-I dl 61 CO CO 00 co C-- t` l0 CO iO lO Cfl tC) If) !n tf) in LC) cp ct+ Cr v+ M Cr) M cr) M M M M M M M -zM cri In In l!) l4 l0 CO r- r- C" m o0 co dl 0> Ol O 0 O 1-1 c-I c-I N N N M M M et+ etc •;:r to I.C) Ln lO CO lO N N C` 00 CO CO CS) C51 01 O 0 0 c-I c-I r-I c-I c-I c-i t-I c-I ri c-i r-1 r-I c I 1-1 r-I c-i c-I c-I r--I r-I c-I c--I c-I c-I N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Cr) Cr) Cr) Cr) CY) M 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 000000000000000000000000000000000000000000000000000000000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 . 0032 36 2 5 Pass 0 . 0032 36 2 5 Pass 0 . 0032 35 2 5 Pass 0 . 0033 35 2 5 Pass 0 . 0033 34 2 5 Pass 0 . 0033 33 2 6 Pass 0 . 0034 33 2 6 Pass 0. 0034 32 0 0 Pass 0. 0035 31 0 0 Pass 0. 0035 31 0 0 Pass 0. 0035 31 0 0 Pass 0. 0036 30 0 0 Pass 0 . 0036 30 0 0 Pass 0 . 0036 29 0 0 Pass 0 . 0037 27 0 0 Pass 0 . 0037 27 0 0 Pass 0 . 0037 26 0 0 Pass Water Quality IMP Flow and Volume for POC 1. On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Perind and Impind Changes No changes have been made . This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages . DRIVEWAY-WWHM VIEWS AND REPORT 1 N\.W/i-4M3 w►+s-sni 4ousef ��_ --- - __ ?fie Edit View `_ r ---- --- - - 1 Tel ® 400711 ..5/44___ LE:27-1 LiPi:1 Iiii.fl = C1 - Y IDS In 501 POC1 PredevelopedA l:g_o:;. 71-±q.:en^y 21OE1 .. xxxxxxxxxxxxxxxxxx=x4wxxxxxxxxxxxxxxxxxxxx ($ 701Inflowio pool mitigate il Flow(C 33v1 0701 0801 111 801 FOCI Mthgatedtlow I ii2 Year lie 0.0008 0.017E 0 .0000 -. .----- .._. .....-.-. ....----- !Iz Year m O .00...E .0243 0.0000 !,i10 : � v 0 ^ A 0 ear . . a .22 .:. '29G v C - :v I;2=_ :ea_ - C .003_ C.. 0313 0.0000 10E O ilov -aa- 0.0037 ti.04:3 ,..0000 Yaws - 0.0043 0,0471 0. 0000 :, jlYeariy ?oaksU ^ 2949 0. 0029 0.0220 0.0000 L 10E-1 iI :930 0.0016 0 .0164 0.0000 1951 0.0012 0 .0199 0 .0000 �oo3°a�' 1982 � ° aa 0.0009 O.0191 0 .0000 aaaaan- ' 1953 O.0004 0.0222 ^..0000 10E-2 , j°aa°°aa 134 0.0006 0.0151 0.0000 1 10 20 30 40 50 60 70 80 90 99 " 1955 0.0007 0.0107 0 0000 jl 1350' 0 .0007 0-0107 0.0000 Cumulative Probability 1357 0 0012 0 0232 0 0000 r,pO Ii ` r.._.. ) ;! 1958 0.0005 0.0160 0.0000 Durations Flow Frequency 1 Water Quality 1 Hydrograph I Wetland Fluctuation-_J . 195 g 0.0013 0.01.3 0.0000 !I 1960 0. C008 0.0231 0.0000 Analyze datasets 1961 0.0004 0.0136 0 .0000 1 PUPALLUPDAILY'EVAPIN/.fENSEN-HAISE-•--- -. -._ it 1962 0.000C 0.0207 0.0000 2-BURLINGTON PREaP ;I 1963 0.0004 0 . 0108 0 .0000 1 ' . �iapedikwo Ii 1364 0.0007 0.0210 0.0000 adhimoPee4A4640mw1 1965 0.0012 0.0479 0.0034 _. - _. . '1 1966 0.0003 0 0136 .0000 1000 Gravel Trench Bed 1 ALL OUTLETS Mitigated 1967 C.0008 0.0336 0.0 0 0 1001 Gravel Trench Bed 1 OUTLET 1 Mitigated 1002 Gravel Trench Bed 1 OUTLET 2 Mitigated '1 1968 0.00 7 0 . 0270 0' 0:0'0 1969 0 0004 0.0106 0. 0000 Flow All Datasets Stage 1 Precip 1-Evap' POC1 I •I 1970 0 0002 0 -0343 0 .0000 - 11971 0. 0019 0.0183 0 .000 Flood Frequency Method I! 1972 0.00f.)8 0.0129 0.0000 Log Pearson Type 11117E ,j 1973 0.C 2204 : . 0153 0 0000 Werbull ' '4 474 n nn1 7 f: nz 59 to '• ^^ 1.1.- Cunnane :i I0...4.-.....111101' °I. ll_lial P 31 :1111aiiiikil 4? 1 WWHM3 dnvewa}2 ite can View Help - - - - -- -____ -______ 1 to 12 a • p Ile.._ rill----- ,,�,�' IraIDI-_ r� ----- --_• _._< _�.__..__ , __. _._ ��._.� �.. r r . - Analysts = [T1 ! ;o 501 POC1 Predeveloped II, I!T1c1,.! Traci., tentry --- ,� 10E 1 j 801 POC1 Mitigated flow !(T-a'.�i C:-? 0801 ---------------------_.--_-_, ::I'2 Year = 0.00 03 0.0064 Year a 0.0006 0.0088 Year = 0 .0008 0.0106 r+ ;,23 Year a 0.0011 0.0131 10E0.kt. 1'6C- Yea: = 0.0014 0.0150 v jt100 Yea.?.-. = 0.0O:$ 0.0171 It; jt0E-1 . ' 1343 0.0010 0 .0080 = L I, -z�:, 0.0006 0.0060 r. 13E: 0.0004 0 .00,72 I; 332 0.0003 0.0066 i! _23 0.0001 0,0081 z I° -. 4 0.0002 3.0055 1 10 20 30 40 ,:6.rl-°r^V•' `u 90 99 ii =35s 0.0002 0.0039 0039 ='-Gu ° lab ve 'ro bability li _ 4 0.0003 0.0084 0 0.084 1' _958 0.0002 0.0058 Durations Flow Frequency Water Oualrty THydrograph >Wetland Fluctuation j i! _3:3 0.0006 0.0041 1 =33v 0 0003 3.0284 Analyze dateaets ii 1561 0.0002 0 .0050 {1 PUYALLUP DAILY EVAPW/JENSEN-HAISE II 13:2 0.0000 0.0075 :i 2 BURUNGTON PRECIP 13:3 0.0022 0.0033 leCid11aw i 1364 0 0003 0 .0076 • 1565 0.0005 0.0174 1000 Gravel Trench Bed 1 ALL OUTLETS Mitigated i 1001 Gravel Trench Bed 1 OUTLEI"1 Mitigated Il 13 6 6 0.0001 0.0049 1002 Gravel Trench Bed1 OUTLET 2Mitigated ) =s6;' 2.v002 0.0122 1003 Gravel Trench Bed 1 STAGE Mitigated 44' =358 0 .2006 0.0038 ,` 1969 0.0001 0.0039 Acres All Deasets Flow I Stag! PFeTip Eve iCOC1 I I! 197.0 0.0001 0.0125 • " :371 0.0007 0.0067 Flood Frequency Method 11 1972 0.0003 0. 0047 ^s Log Pearson Type lil 17B II 1973 0.0 002 v 005 s Weibull p " ;74 d ' 00R n nn7,c r Gunnane 4 r t "1 WItli-A13 dr.vev,'31:2 e El: s':!.e..1. Heir- &-- .. _ ._ i ii 4411M111 fib I 4.&:7 -C-'4F° I Linnumn 1 id ME -,_____..-.--------• ,.....,,47 II I .....___,. ____,..... Basin 1 Nlittoated SCENARIOS I. 1 Subbasin Name- (Basin .1 i 7 Designate as Bypass for POO .7,..,, ,iid` ';-•Predevelooed Surface Interfiow Groundwater 1 . . . Flows To : . i MitIgnied Area in Basin Fi Show oniv Selected =Ion Scenc,,c, .? Available Pervious Available Impervious FI FMFNTS i.;:i C Forest Flat • ...... . . _ .. it) ;7:i ROOFTOPS FLAT-- ---: i-0 _._ . ._ . .. . 4111111, F.- iFilSiEWAY ,, i,s,..--e ildie a . - , . . a may. e : , 1 . move Elements . . . Pe rVIOUsTota '.0 ' Acres Impervious Total 0.028 ' Acres ill •P) _.4,1.__ - Basin Total 0 028 'acres -. Sava xy Load xv' 4 , I 1• -- 1 Deselect Zero Select BY- GO .--:"---, at II Ilk 11 ' 0 a '. - 'I Fnr. - -- - - . .._ . . .._. . . i WW1-1M3 driveway2 ile Edit View 'Help ............_ _ ...... , _..... 4:7 limm..10 ..--.. ...:Z1108' 1 N E 1.11711.7.:-_-_---I linglaSilll.4.141141 11 11F141.11111101 ---........---- . .. . — Basin 'Mitigated SCENARIOS I i . Subbasin Name. Basin 1 r Designate as E3ypass.for POC. n5 r Predeveloped I ! Surface Interflow Groundwater 5;Mitmve:... 21 i. , Rows To : i _i 1 . Area in Basin 1.7 iSlicow Onto Selected Run Soenano I i Available Pervious Available Impervious F I FMFNTS • , 57 C.WoresiTlal- -- !II— - iTo Rob FiCPS FLAY 4 -7 fo--- _ . , :. 1 ! ili' b-141NiEWAYSLAT . '028 ki ri.1 .'-r.• ... d pow Puma Zj i', i 1;71,...... ii , :I .I. Move Elements i 1 411 I ! Pe rvio usTota tr0-----1 Acres j Acre Impervious TotaI 0.028 Acres I Basin Total 10.028 ! ; 1 3ave x.y I Load xy:,- I 4 t '< ..41.) ___ : 1 •Y. :12,_‘.........__,.; ' Deselect .Zero Select BY- GO . — , .1; an. 111r1"111101 4 el ' Illrll,lir-ill 111711 117111"F ' P 31 1 - i Western Washington Hydrology Model PROJECT REPORT Project Name: driveway2 Site Address: City Report Date : 9/28/2017 Gage Burlington Data Start 1948/10/01 Data End 1999/09/30 Precip Scale: 0 . 83 WWHM3 Version: PREDEVELOPED LAND USE Name : Driveway Bypass: No GroundWater: No Pervious Land Use Acres C, Forest, Flat . 028 Impervious Land Use Acres Element Flows To: Surface Interflow Groundwater Name Basin 1 Bypass: No GroundWater: No Pervious Land Use Acres Impervious Land Use Acres DRIVEWAYS FLAT 0 . 028 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0. 000279 5 year 0.000584 10 year 0.000815 25 year 0.001122 50 year 0.001353 100 year 0.00158 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(ofs) 2 year 0.006393 5 year 0.008842 10 year 0.010627 25 year 0.013072 50 year 0.015036 100 year 0.017125 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.001 0.008 1951 0.001 0.006 1952 0.000 0.007 1953 0.000 0.007 1954 0.000 0.008 1955 0.000 0.006 1956 0.000 0.004 1957 0.000 0.004 1958 0.000 0.008 1959 0.000 0.006 1960 0.001 0.004 1961 0.000 0.008 1962 0.000 0.005 1963 0.000 0.008 1964 0.000 0.004 1965 0.000 0.008 1966 0.000 0.017 1967 0. 000 0.005 1968 0.000 0.012 1969 0.001 0.010 1970 0.000 0.004 1971 0.000 0.012 1972 0.001 0. 007 1973 0.000 0.005 1974 0.000 0.006 1975 0.001 0.006 1976 0.002 0. 012 1977 0.000 0.009 7978 0. 000 0.005 1979 0. 000 0.010 1980 0. 000 0.005 1981 0. 000 0.007 1982 0. 000 0.005 1983 0. 001 0.006 I 1984 0.000 0.005 1985 0.001 0.007 1986 0.000 0.007 1987 0.000 0.005 1988 0.000 0.004 1989 0.001 0.011 1990 0.000 0.006 1991 0.000 0.007 1992 0.001 0.010 1993 0.000 0.006 1994 0.000 0.004 1995 0.000 0.005 1996 0.000 0.005 1997 0.000 0.008 1998 0.001 0.014 1999 0.000 0.007 2000 0.000 0.004 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0024 0.0174 2 0.0011 0.0144 3 0.0010 0.0125 4 0.0009 0. 0122 5 0.0007 0. 0116 6 0.0007 0. 0108 7 0.0007 0.0103 8 0.0006 0.0102 1 9 0.0006 0.0098 1 10 0.0006 0.0088 11 0.0006 0.0084 12 0.0006 0.0084 13 0.0005 0.0081 14 0.0005 0.0080 15 0.0004 0.0077 16 0.0004 0.0076 17 0.0004 0.0075 18 0.0003 0.0072 19 0,0003 0.0072 20 0.0003 0.0072 21 0.0003 0.0070 22 0.0003 0.0069 23 0.0003 0.0067 24 0.0003 0.0067 25 0.0003 0.0066 26 0.0003 0.0064 27 0.0003 0.0062 28 0. 0003 0.0061 29 0.0003 0.0060 30 0.0002 0.0058 31 0.0002 0.0056 32 0.0002 0.0055 33 0.0002 0.0055 34 0.0002 0.0055 35 0.0002 0.0054 36 0.0002 0.0053 37 0. 0002 0.0052 38 0. 0002 0.0052 39 0.0002 0.0050 40 0. 0002 0.0049 41 0. 0001 0.0047 42 0.0001 0.0047 43 0.0001 0.0046 44 0.0001 0.0044 45 0.0001 0.0041 46 0.0001 0.0040 47 0.0001 0.0039 48 0.0001 0.0039 49 0.0000 0.0039 50 0.0000 0.0039 51 0.0000 0.0038 POC #I Facility FAILED duration standard for 1+ flows. Flow(CFS) Predev Dev Percentage Pass/Fail 0.0001 4538 36765 810 F'u i .l 0.0002 3991 35393 886 Fail 0.0002 3462 34154 986 Fail 0.0002 3061 33225 1085 Fail 0.0002 2733 32281 1181 Fail 0. 0002 2468 31334 1269 Fail 0.0002 2212 30350 1372 Fail 0. 0002 2005 29487 1470 Fail 0.0002 1821 28647 1573 Fail. 0.0002 1654 27838 1683 Fail 0.0003 1490 27078 1817 Fail 0.0003 1365 26465 1938 Fail 0.0003 1243 25884 2082 Fail 0.0003 1118 25379 2270 Fail 0.0003 1025 24780 2417 Fail 0.0003 930 24234 2605 Fail 0.0003 857 23702 2765 Fail 0.0003 798 23211 2908 Fail 0.0004 744 22710 3052 Fail 0.0004 696 22223 3192 Fail 0.0004 646 21780 3371 Fail 0.0004 602 21311 3540 Fail 0.0004 554 20788 3752 Fail 0.0004 510 20332 3986 Fail 0.0004 475 19925 4194 Fail 0.0004 439 19473 4435 Fail • 0.0005 401 18959 4727 Fail 0.0005 371 18584 5009 Fail 0.0005 346 18280 5283 Fail 0.0005 325 17918 5513 Fail 0.0005 307 17569 5722 Fail 0.0005 291 17265 5932 Fail 0.0005 273 16903 6191 Pdil 0.0005 247 16568 6707 Fu.il 0.0006 220 16255 7388 Gail 0 , 0006 200 15955 7977 Fail 0.0006 187 15678 8383 Fail 0.0006 172 15392 8948 Fail 0.0006 158 15106 9560 Fail 0.0006 152 14829 9755 Fail 0. 0006 142 14578 10266 Fail 0. 0006 134 14270 10649 Fail 0. 0007 128 14 037 10966 Fail 0. 0007 123 13791 11212 Fail 0. 0007 116 13546 11677 Fail 0. 0007 112 13291 11866 Fail 0.0007 105 13036 12415 Fail 0.0007 100 12795 12795 Fail 0.0007 94 12540 13340 Fail 0.0007 90 12258 13620 Fail 0.0008 89 12084 13577 Fail 0.0008 86 11883 13817 Fail 0.0008 86 11641 13536 Fail 0.0008 82 11386 13885 Fail 0.0008 78 11149 14293 Fail 0.0008 75 10957 14609 Fail 0.0008 74 10756 14535 Fail 0.0008 72 10577 14690 Fall 0.0009 69 10407 15082 Fail 0.0009 67 10246 15292 Fail I 0.0009 64 10085 15757 Fail 0.0009 60 9893 16488 Fail 0.0009 60 9710 16183 Fail 0.0009 58 9500 16379 Fail 0.0009 56 9330 16660 Fail 0.0009 54 9133 16912 Fail 0.0009 53 8941 16869 Fail 0.0010 51 8816 17286 Fail 0.0010 50 8686 17372 Fail 0. 0010 48 8588 17891 Fail i 0.0010 47 8472 18025 Fail 0. 0010 46 8351 18154 Fail 0.0010 43 8221 19118 Fail 0.0010 43 8114 18869 Fail. 0.0010 41 8002 19517 Fail 0.0011 39 7908 20276 Fail 0.0011 39 7792 19979 Fail 0.0011 38 7667 20176 Fail 0.0011 38 7586 19963r.a.il 0.0011 38 7488 19705 Fail , 0.0011 37 7403 20008 Fail 0.0011 37 7327 19802 Fail 0.0011 37 7233 19548 Fail , 0.0012 36 7157 19880 Fail 0.0012 36 7023 19508 Fail 0.0012 35 6938 19822 Fail 0.0012 35 6840 19542 Fail 0.0012 34 6750 19852 Fail 0.0012 33 6665 20196 Fail 0.0012 33 6576 19927 Fail 0.0012 32 6509 20340 Fail 0.0013 31 6420 20709 Fail 0 . 0013 31 6317 20377 Fail 0 . 0013 31 6227 20087 Fail 0 . 0013 30 6156 20520 Fail 0 . 0013 30 6084 20280 Fail 0 . 0013 29 6013 20734 Fail 0 . 0013 27 5937 21988 Fail 0 . 0013 27 5874 21755 Fail. 0 . 0014 26 5816 22369 fail. The development has an increase in flow durations from 1/2 predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. Water Quality BMP Flow and Volume for POC 1. On-line facility volume: 0 acre-feet On-line facility target flow: 0 ofs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Perind and Imp1nd Changes No changes have been made. This program and accompanying documentation is provided 'as-is' without warranty of any kind, The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages . ANACORTES PUBLIC WORKS DEPARTMENT oil :°� Steven Lange, Project Manager 9i. � fit, P.O.BOX 547,ANACORTES,WA 98221 PH(360)293-1920 E-MAIL:stevel@cityofanacortes.org FAX(360)293-1938 9Cog, Memo Date: November 17,2017 To: Paul Ingalls, Plans Examiner From:Tim Hohmann for Steven Lange Subject: Drainage Plan Review#2 for 220215"'Street cc: Eric Shjarback, Justin Symonds, Kait Nelson The submitted drainage plan for 2202 15t" Street was reviewed by the Public Works Engineering Department on November 14, 2017. • 11-08-17: Submittal to Public Works Engineering in PM • 11-14-17: Public Works review and memo back to Building Department • 11-16-17: Submittal to Public Works Engineering in PM • 11-17-17: Public Works review and memo back to Building Department A revised drainage report addressing Minimum Requirements#1 to#9, a stormwater site plan and a Geotechnical Report were provided by the applicants Engineer to Public Works Engineering for review. The following comments are provided: Stormwater Site Plan: • The requested revisions to the Site Plan have been completed. Drainage Report: • The drainage report still contains multiple misstatements and contradictions. Some of these contradictions result from the addition of comments and revision of methodology as a result of the last review comments without modifying statements made earlier in the drainage report. However, the stormwater site plan conforms to the results of the drainage report as contained in the summary and Minimum Requirements sections of the report which state that LID Performance standard has been met for this project. The Engineering department concurs that the drainage report has met the LID Performance Standard for this project by demonstrating that stormwater is infiltrated onsite in the developed condition for storms up to and including the 100 year storm. This exceeds the LID performance standard of 'Stormwater discharges shall match developed discharge durations to pre-developed durations for the range of pre-developed discharge rates from 8% of the 2-year peak flow to 50% of the 2-year peak flow."as contained in the MR#5 section of the DOE manual. Furthermore the Engineering department concurs that F 4�` c K • Water • Wastewater • Streets • Storm Drainage • Engineering • Solid Waste *19 • Transportation •Equipment • Capital Projects • Development Services q��p: the thresholds for requiring the construction of stormwater treatment facilities are not met by this project per the MR#6 section of the DOE Manual. Additionally this project exempt from MR#7 as it indirectly discharges to salt water via the City stormwater system. This basin is built out to near full buildout and has been for decades and has no know capacity issues. Therefore in the interest of facilitating this building permit and not placing burdensome costs on the applicant due to multiple correction and resubmittal cycles the Public Works department is accepting the conclusions of the Drainage Report and what is shown on the Stormwater site plan despite the misstatements and contradictions contained in the drainage report. ft 4e0, s o Water • Wastewater • Streets • Storm Drainage • Engineering • Solid Waste 4 ' 4 • Transportation•Equipment • Capital Projects • Development Services L PLANNING, COMMUNITY, &ECONOMIC DEVELOPMENT DEPARTMENT ... PLAN REVISION /ADDITIONAL INFORMATION COVER SHEET , .- - ` 1;1.', Mailing Address: P.O. Box 547, Anacortes, WA 98221 \ a ': 1 Office Location: 904 614 Street, Anacortes WA 98821 �s NOV 1.•`� 1` i Phone: (360)299-1984, Fax: (360) 293-1938 Permit/Project#: 3LD -201 1 - 0' - _9 Date: 10 — 31-- 1 -I Project Name: Project Address: '2_202 ( L+" S?I�t " Project Contact: j 1 _. i 1,14-r«.p. Company Name: D�S�12) M 1 1 v Contact Phone: -j(00---1S43-- 9,C)2Jf 14 ( Contact Email:J(tL,�It` I cif1 el qr,)C Qrrir ► _corn Has the permit been issued yet? 0 Yes l3 No 1 All revisions must be either clouded or highlighted &wet stamped by an architect/engineer(if applicable). Has this been done? 0 Yes 0 No N/A Is the plan revision or additional information,in response to a plan review letter? 0 Yes. A copy of the plan review letter with itemized responses to each item is required. No,the revision or additional information is initiated by the applicant, designer,or builder. If not in response to a Plan Review Letter, please explain the nature of the revisions and/or additional information: p it-S S-t-FO w Cat 4 C . PAT-1 C, 1'cT t3, (g, a t= l--ci ( At-DO. -T1-F e .,c0--. .. i tb,( G ,tJct -t-__ D IG A P -K 2 cam( A- -t i r v r--i -)++--�- L S E1� .CIAUs("---ir-ri e1 Are you submitting a full replacement ('l Yes fc No NIA A If not,what page#or title is being replaced: S i-q- ( D CK P LA-NI ,-c.DBTi-(DU t-t -) Two full sized copies of all revised /additional information is required. Has this been done? 7,Yes ❑ No Cheek the box next to the type of plan, report, or calculation where revisions or additional information can be found. ❑ Site Plan 7Building Plans 0 Structural Plan ❑ Landscape Plan 0 Parking Plan 0 Tree Preservation Plan ❑ Arborist Report 0 SEPA checklist ❑ Wetland Report ❑ Geotechnical Report 0 Storm Drainage Analysis 0 TESC Plan O Civil Plan El Lot Coverage Calculations ❑ Impervious Surface Calculations ❑ FAR Calculations 0 Grading Plan 0 Survey (Boundary/Topographic) O Mechanical Plan 0 Plumbing Plan ❑ Other: , .'r-,Q.. PLANNING, COMMUNITY, &ECONOMIC DEVELOPMENT DEPARTMENT '. PLAN REVISION /ADDITIONAL INFORMATION COVER SHEET Mailing Address: P.O. Box 547, Anacortes, WA 98221 ` Office Location: 904 6th Street,Anacortes WA 98821 Phone: (360) 299-1984, Fax: (360) 293-1938 NOV 0 2 2011 Please use this torm to submit revisions or addatwo�atal informati?u to your r fern ut eatiain Permit/Project 2Dfl - U —g Date: I 1 — I — f Project Name: Project Address: 2.2 ✓ Stir Project Contact:, pcc_.(L i t,,(S-112 Company Name: p . ,4 ,�t ��- Contact Phone: 3(420 _9 a,(t4=6 (5 Contact Email Has the permit been issued yet? ❑ Yes a No All revisions must be either clouded or highlighted &wet stamped by an architect!engineer(if applicable). Has this been done? C? Yes 0 No Is the plan revision or additional information, in response to a plan review letter? 0 Yes. A copy of the plan review letter with itemized responses to each item is required. tg,No,the revision or additional information is initiated by the applicant,designer,or builder. If not in response to a Plan Review Letter, please explain the nature of the revisions and/or additional information: i��I s t�( r%lJ y' C �CD i--c�. CPT 2cr ( 0 QT- G . Are you submitting a full replacement () Yes ( . No If not,what page #or title is being replaced: ?-2_ Two full sized copies of all revised/additional information is required. Has this,been done? n Yes 0 No Check the box next to the type of plan, report, or calculation where revisions or additional information can be found. ❑ Site Plan l7 Building Plans ❑ Structural Plan ❑ Landscape Plan (❑ Parking Plan 0 Tree Preservation Plan ❑ Arborist Report 0 SEPA checklist 0 Wetland Report ❑ Geotechnical Report 0 Storm Drainage Analysis 0 TESC Plan ❑ Civil Plan 0 Lot Coverage Calculations 0 Impervious Surface Calculations ❑ FAR Calculations 0 Grading Plan 0 Survey(Boundary/Topographic) ❑ Mechanical Plan 0 Plumbing Plan 0 Other: i �' �} ice' I pl v 1,!I9 _, G, COMMUNITY, &ECONOMIC DEVELOPMENT DEPARTMENT ' AN REVISION /ADDITIONAL INFORMATION COVER SHEET 0 2011 ! Mailing Address: P.O. Box 547,Anacortes, WA 98221 c11, Li' Mailing Location: 904 6t Street, Anacortes WA 98821 CITY OF ANACOI iTES Phone: (360) 299-1984, Fax: (360)293-1938 Please use this form to submit revisions or additional information to your permit application. Permit/Project#: Date: ` //ZQ// Project Name: 5'e-pN 0 Project Address: ;taa. 1��� 3 T rzs.a r Project Contact: R 0.4- S Hww Company Name: LA ND" Ca�.-,-., Contact Phone: 4-25-766 -9'3$`d Contact Email: A-C4' e- \..,,., ,e)3 e 4 r c,a Has the permit been issued yet? 0 Yes C 'No All revisions must be either clouded or highlighted &wet stamped by an architect!engineer (if applicable). Has this been done? ❑ Yes ❑ No Is the plan revision or additional information, in response to a plan review letter? O Yes. A copy of the plan review letter with itemized responses to each item is required. ITo,the revision or additional information is initiated by the applicant, designer,or builder. If not in response to a Plan Review Letter, please explain the nature of the revisions and/or additional information: E i s? CON vL-0.\.. lb Lib - .v+n,, No v c ve.Ca.t.+T (c'l t,.A\P 5 Are you submitting a full replacement r Yes (✓ No If not,what page#or title is being replaced: /, Two full sized copies of all revised /additional information is required. Has this been done? I1 Yes ❑ No Check the box next to the type of plan, report, or calculation where revisions or additional information can be found. ❑ Site Plan ❑ Building Plans ❑ Structural Plan ❑ Landscape Plan 0 Parking Plan 0 Tree Preservation Plan O Arborist Report ❑ SEPA checklist 0 Wetland Report ❑ Geotechnical Report 0 Storm Drainage Analysis 0 TESC Plan ❑ Civil Plan ❑ Lot Coverage Calculations ❑ Impervious Surface Calculations ❑ FAR Calculations ❑ Grading Plan 0 Survey(Boundary/Topographic) ❑ Mechanical Plan ❑ Plumbing Plan AV Other: Eac5 ie 17Y0 1-- L►0 zr..N,pogcwlarav 9"w Fyrrce, Groc From: Fyrrce, Groc Sent: Friday, November 17, 2017 11:48 AM To: 'Jack Reinstra' Cc: Hohmann, Tim Subject: 2202 15th Street Hi Jack, 2202 15th Street needs to have 2 full size sets of the latest Erosion Control and LID Improvement plan that was provided in 11"x 17" format and approved by Public Works, so that we can issue the permit. Please provide them at your earliest convenience. Best regards, Groc Fyrrce Building Inspector/Permit Technician City of Anacortes (360)293-1901 ti7/r./inyie/r e u(9 Comm it/m:16/Arrt<c,4 ea./meadow coizdrar�rn rilicn My incoming and outgoing email messages are subject to public disclosure requirements per RNV 42.56. 1 v�rr.r. PLANNING, COMMUNITY,&ECONOMIC DEVELOPMENT DEPARTMENT r .., o PLAN REVISION /ADDITIONAL INFORMATION COVER SHEET ', MailingAddress:P.O. Box 547, Anacortes, WA 98221 r �qrco Office Location: 904 6th Street, Anacortes WA 98821 Phone: (360)299-1984, Fax: (360) 293-1938 l d (_ " ,t to k'n.,iil ' •-1 t,,,c . to ,rit7 7 t i1,` lily r, 1 1 i I I y i 1 Permit/Project#: 1 L ) -2O 17 - O t-cl - Date: 10-t 0 - 1-1 Project Name: `` Project Address: 2202 t 5-Le- ST ,8`r Project Contact: 3P 2. l t�A Company Name: n v _a'( e E r�1�1 a. Contact Phone:,31d.7- I -902I � (' Contact Email: �4t'� •C(.�K�edG err+ .Cl) Has the permit been issued yet? ❑ Yes No All revisions must be either clouded or highlighted &wet stamped by an architect/engineer' 'mpl#,IeOin Has this been done? 0 Yes 0 No l 1 V�A Is the plan revision or additional information,in response to a plan review letter? OCT 11 2Q11 ❑ Yes. A copy of the plan review letter with itemized responses to each item is required. lt.No, the revision or additional information is initiated by the applicant,designer, or builder. CITY OF ANACORTES If not in response to a Plan Review Letter, please explain the nature of the revisions and/or additional information: gvic�c�eiR L-\-A� t-ri. -Tc `` eL et:-,. " pt,6,,t.I . Are you submitting a full replacement lC Yes c! No If not,what page#or title is being replaced: Two full sized copies of all revised/additional information is required. Has this been done? IF Yes El No Check the box next to the type of plan, report, or calculation where revisions or additional information can be found. El Site Plan )I. Building Plans 0 Structural Plan ❑ Landscape Plan El Parking Plan 0 Tree Preservation Plan , ❑ Arborist Report 0 SEPA checklist 0 Wetland Report El Geotechnical Report 0 Storm Drainage Analysis Cl TESC Plan ❑ CiviI Plan 0 Lot Coverage Calculations 0 Impervious Surface Calculations ❑ FAR Calculations 0 Grading Plan 0 Survey(Boundary/Topographic) ❑ Mechanical Plan 0 Plumbing Plan 0 Other: 1 r. ttii iAi oCT 13 2011 CITY OF ANACORTE October 10, 2017 Anacortes Planning &Community Development Dept. Attn: Groc Fyrrce RE: Plan change for the proposed home/ADU at 2202 15th Street. Since our first submittal of our Padilla ADU plans for 2202 15th Street, it was decided to reverse the plans. Structural, nothing changes, however, I am submitting a reversed set so upon approval, the job site will have the correct and approved orientation. You already have the updated site and landscape plans. I have included two sets of plans and two copies of the floor plans. Jack Reinstra Landed Gentry LANDED GENTRY HOMES AND COMMUNITIES LANDED GENTRY 504 East Fairhaven Avenue e �h '� Burlington, WA 98233 (360) 755-9021 NOV Q 9 201 j Transmittal Sheet on O3 A A .:,t,= To: Groc Fyrrce From: Steve Baughn� Re: 2202 15th Street—BLD-2017-0349 Date: November 9, 2017 Planning, Community&Economic Dev. CC: 0 Urgent 0 For Review ❑Please Comment 0 Please Reply 0 Please Recycle Attention: Paul Ingalls and Kait Nelson Re: Responses to the email from Paul Ingalls to Jack Reinstra, dated November 8, 2017, regarding the above reference project. Paul Ingalls stated: We received revisions November 7th from your office that show a change from concrete patios to wood framed decks at the back of the house. Please supply a revised site plan indicated the increase in lot coverage accordingly. Response: 1 have revised to Lot Coverage calculations to include the proposed deck areas on the Site Plan as requested, as well as on the Erosion Control Plan. Two full sized copies of each have been included with this submittal, along two reduced (I I x l 7) copies of same. List of items included with this transmittal: (2) Revised Site Plan sheets 1 of 1,both full sized and reduced. 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Gr<aunde�ater Area in Basin 1- Show Only Selected Run Scenario Available Pervious Available Impervious P ry1 ;1- -- i i N.Forest Flat . . _.._ C ROADS T - --- --, ,Q - - MIME ..�. ' _ AjB_Forest Mod r ROADS/MOD- - `0 J i� 1 fl' .Form Steep 0 ROADS/STEEP - a^ -" i ii Ni,Pasture Flat 0 :� ROOFS OPS FL+�T -� i0 -v _-.-a ,,,,..!"1, ,,,., !._. A/a,Pasture,Mod 0 1,o DR11iEWAYS FLAT ;0 iii lila MIN UR E �tB,Pasture,Steep - - DN RcWAYS/MOD r 'D -_ - _ .Lavari,Flat . 0 DRiVEWAYSTEEP 1 `D s 5 i NB.Lawn,Mod . c, 1� SIDEWALKS/FLAT 1 j hJ8_La+ron.Steep - = 0 51DE MO...„. S/ L_ ' il l- __ -.___ 0 rd C,Forest Fiat Li SIDEWALKS/STEEP ,0 i - C Forest Mod -- PAR T ... i 10 - d Forest;Steep- 0 PARK1NG1MOD .-- . . gip- - - . - C,_Pasture.Flab - 0 PARKING//iFEP 10 C Pasture.Mod 0 POND __. ' .0 C:Pasture.Steep - 0 C,Lawn,Fiat 0 . . . _ - _ . C.Lawn.Mod n Move Elements ' - - 9 C,Lauri Steep +I1 t -z_ -- PerviousTota -�-4 = f� Acres Impervious-ata1 11_" --1 Acres -. - r Basin Total i0.011 I____.-. Acres Savexy Lord xyr 11 j Y 112 -- ----- --'-_--- 11 BY"Zero Select � " GO _________ ._-- ._ , ,.., jl P�l _. Western Washington Hydrology Model PROJECT REPORT Project Name: Sidewalk Site Address : City Report Date : 10/19/2017 Gage Burlington Data Start 1948 /10/01 Data End : 1999/09/30 Precip Scale: 0 . 83 W H 43 Version: PREDEVELOPED LAND USE Name Driveway Bypass: No Groundwater: No Pervious Land Use Acres C, Forest, Flat . 011 Impervious Land Use Acres ti Element Flows To: Surface Interflow Groundwater Name Basin 1 Bypass: No Groundwater: No Pervious Land Use Acres Impervious Land Use Acres SIDEWALKS FLAT 0. 011 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE 1984 0.000 0.002 1985 0.000 0.003 1986 0.000 0.003 1987 0.000 0.002 1988 0.000 0.002 1989 0.000 0.004 1990 0.000 0.002 1991 0. 000 0.003 1992 0.000 0.004 1993 0.000 0.002 1994 0.000 0.002 1995 0.000 0.002 1996 0. 000 0.002 1997 0. 000 0.003 1998 0.000 0.006 1999 0.000 0.003 2000 0.000 0.001 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0010 0.0068 2 0.0004 0.0056 3 0.0004 0.0049 4 0.0003 0.0048 5 0.0003 0.0045 6 0.0003 0.0043 7 0.0003 0.0040 8 0.0002 0.0040 9 0.0002 0.0039 10 0.0002 0.0035 11 0.0002 0.0033 12 0.0002 0.0033 13 0.0002 0.0032 14 0.0002 0.0031 15 0.0002 0.0030 16 0.0002 0.0030 17 0.0002 0.0030 18 0.0001 0.0028 19 0.0001 0.0028 20 0.0001 0.0028 21 0.0001 0.0027 22 0.0001 0.0027 23 0.0001 0.0026 24 0.0001 0.0026 25 0.0001 0.0026 26 0.0001 0.0025 27 0.0001 0.0024 28 0.0001 0.0024 29 0.0001 0.0023 30 0.0001 0.0023 31 0.0001 0.0022 32 0.0001 0.0022 33 0.0001 0.0022 34 0.0001 0.0022 35 0.0001 0.0021 36 0.0001 0.0021 0.0002 200 15964 7982 Fail 0. 0002 186 15665 8422 Fail 0.0002 174 15459 8884 Fail 0. 0002 159 15137 9520 Fail 0.0002 152 14851 9770 Fail 0.0002 142 14587 10272 Fail 0.0003 134 14279 10655 Fail 0.0003 130 14086 10835 Fail 0.0003 123 13827 11241 Fail 0.0003 117 13568 11596 Fail 0.0003 113 13313 11781 Fail 0.0003 105 13045 12423 Fail 0.0003 101 12839 12711 Fail 0.0003 95 12567 13228 Fail 0.0003 91 12303 13519 Fail 0.0003 89 12097 13592 Fail 0.0003 87 11891 13667 Fail 0.0003 86 11637 13531 Fail 0.0003 82 11440 13951 Fail 0.0003 80 11185 13981 Fail 0.0003 75 10979 14638 Fail 0.0003 74 10760 14540 Fail 0.0003 72 10582 14697 Fail 0. 0003 71 10443 14708 Fail 0.0003 67 10264 15319 Fail 0.0003 64 10099 15779 Fail 0.0003 60 9911 16518 Fail 0.0004 60 9714 16189 Fail 0.0004 58 9536 16441 Fail 0.0004 57 9343 16391 Fail 0.0004 55 9160 16654 Fail 0.0004 53 8959 16903 Fail 0.0004 51 8820 17294 Fail 0.0004 50 8717 17434 Fail 0.0004 49 8606 17563 Fail 0.0004 47 8485 18053 Fail 0.0004 46 8369 18193 Fail 0.0004 43 8235 19151 Fail 0.0004 43 8145 18941 Fail 0.0004 41 8029 19582 Fail 0.0004 39 7926 20323 Fail 0.0004 39 7810 20025 Fail 0.0004 38 7676 20200 Fail 0.0004 38 7586 19963 Fail 0.0004 38 7501 19739 Fail 0.0004 37 7421 20056 Fail 0.0004 37 7336 19827 Fail 0.0004 37 7238 19562 Fail 0.0005 36 7162 19894 Fail 0.0005 36 7050 19583 Fail 0.0005 35 6956 19874 Fail 0. 0005 35 6853 19580 Fail 0.0005 34 6759 19879 Fail 0.0005 33 6670 20212 Fail 0.0005 33 6607 20021 Fail 0.0005 32 6522 20381 Fail 0.0005 32 6429 20090 Fail t t.► CL -y- g„ tty Jr1. ;j S :itLtr-1='...r.•.:;.4-;1.34z,7,34„-.j1 "kt/L(—*"s.f..4'_ t _ `'') tC) 3: ice? Cr F-+ �.: ....i • ,,:(("L›,,1"•E..1.1, .ix.xV_•) 41,:C1:i‹1-„..—a—.-....1E....I4.., =„4a8i•—.--"0-)41 Z�hJ £i9 I k..: ,.,:., ' `j Y ..t I l \ 1\ t l: f6 =C"9 — it") �_._...._,._. ._./}' i�l/yr}{ IS� try_ 'X3 _; ....... . .r ! 1Ja /J � 7b Y �•1 t ', 1.'Y.uyuu.0 , t..q•r s'`S's' < Ml '^• . " ♦ ` - sZ:•Y•r 5 -° A •'i f 3'>-..;�, • "''4 ,� J Y i f, '., ....._...u...�...._.. .. Q, V. °�. ...4' : t �y ' .t Y ^.7 y . =, tam..! "" ..,....�Y ,� r t- Le l W L E >-- \ • f LU `? 2 `e I',CI :.--, ter` I ;u: L (/) w r ,,.., I 4 }--�,d \. W tom/) f ,rY 1 I ► ,..I t��,.4 .._.. I— „,.., 2 pi - .'—.. I u-)1 co c ry = . re 1� . IT Li v) r l!3 I r__ 1 11 CA C\ L.LJ 1:4./.... • 1 t I 8.4 ff. a- 1--- ca.... I : i .. v - (,-) .. —i ., .,.., 1 ED t ///1 —' c._5 • ;.; XCU 1 i E > Via, s �_ r _ � I II ! t..a:J rN ,i 8'G i __.. C a t tj Cu ..._! I :>z ! ► co s co 'fib .ama r1x . v ax di t pp b tay�l . OJ e+wo�3 `� H d pq�o .—J a a ,r No my) N cpa am (9 rwr�-1 Cl r a Zla a w QY-IT .{: , J. t` Qv) j ;x '-1 to_ ,•-, C� ors y. d q S. rt 41 L�1 (••, to Ac zn aw PG wa n� a � � , uO N � <J Z Cq .44 L. La n. e a va v4 v, >x a.(..)(.4 0 L.>> � , ek- 0 I, ....y flit. ► t t" r y y Y(" t) it r: 7 ; 3� ' F P a.,� 1=41 f t ' t ,! ►1 E h OCR' •2 7 2017 I __ __ . CITY OF ANACORTES i , I 6` CURB --- CURB LOCATED PER PLAN F SAW CUT 24' RIGHT OF WAY ! `�3 HER, ,,`'i�., FROM EDGE OF �C %�0 �` r•-+ NEW EDGE^vLlTTER 4` GRAVEL DR CRUSHED ROC s_. �y v f „gi r_. '- EXIST. 5 _ y �:. PAVEMENT 7 ro SIDEWALK Q !-a fi. r, _ 1111 I ' itei ,-. 4 2783 F �i �"+ 0� OfSTcRc� \J4Cy Fa .� Q �IONA' E� > ev a . 5T-I STREET READ = Tip\ A- A N.T.S. (SECTION 5-05 AND SECTION 9 OF THE CURRENT PLANS AND SPECIFICATIONS FOR ROAD I M , ;� BRIDGE AND MUNICIPAL CON I STRUCTON. ,f 0 3" HMA - CL. 1/2-INCH P66422 CONFORMING TO SECTION 5-04 OF THE CURRENT STANDARD SPECIFICATIONS, COMPACTED TO A MINIMUM OF 92% RICE DENSITY. WHERE PROPOSED ASPHALT ABUTS EXISTING.ASPHALT, THE EXISTING ASPHALT SHALL BE SAW CUT FULL DEPTH AND TACK COATED IMMEDIATELY BEFORE PAVING. ALL SURFACE JOINTS SHALL CURB/GUTTER AND SIDEWALK WORKMANSHIP AND AESTHETICS BE SEALED WITH AR-4000 OR EQUAL. 1. CURB/GUTTER AND SIDEWALK CONSTRUCTION SHALL FOLLOW A TRUE AND UNIFORM 0 3" CRUSHED SURFACING TOP COURSE SHALL CONFORM TO SECTION 9-03.9(3) OF THE HORIZONTAL AND VERTICAL ALIGNMENT. CURRENT STANDARD SPECIFICATIONS, COMPACTED TO A MINIMUM OF 95% MAXIMUM DENSITY IN ACCORDANCE WITH ASTM D-1557 TESTING. 2. THE VERTICAL AND HORIZONTAL. SURFACE SHALL BE A SMOOTH BROOM FINISH WITH NO DETECTABLE FINISHING BLEMISHES, UNDULATIONS, RIPPLES, SWELLS, WAVES, RUTS, ® MINIMUM S" GRAVEL BORROW PER SECTION 9-03.14 (1) OF THE CURRENT STANDARD FURROWS, GRAFFITI OR OTHER OBJECTIONABLE MARKS, THE END RESULT SHALL BE A SPECIFICATIONS COMPACTED TO A MINIMUM ON 95% MAXIMUM DENSITY PER ASTM 0-1557 NEAT AND PROFESSIONALLY FINISHED APPEARANCE. ItsfING. PERCENTAGE PASSING THE 1200 SIEVE SHALL NOT EXCEED 5%. DEPENDS ON SOIL CONDITIONS AND MAY BE DEVIATED WITH NEW ENGINEERED CROSS-SECTION. SUBMIT 3. THE EDGE FINISH ADJACENT TO THE EXPANSION JOINT MAItNIAL SHALL BE CLEAN PROTOCAL'S SIEVE TO CITY. AND FREE OF EXCESS SLURRY. THE EXPANSION JOINT MATERIAL SHALL BE TRIMMED TO A LEVEL EVEN WITH THE ADJACENT CONCRETE RESULTING IN A NEAT AND 04 THE EXCAVATED SUBGRADE SHALL BE FREE OF TOPSOIL, ORGANICS, AND OTHER PROFESSIONALLY FINISHED APPEARANCE. DELETERIOUS MATERIAL, COMPACTED TO A MINIMUM OF 95% MAXIMUM DENSITY IN 4, THE CITY ENGINEER IN HIS SOLE DISCRETION RESERVES THE AUTHORIY TO ORDER ACCORDANCE WITH ASTRT 8-1557 TESTING, PREPARED CONFORMING TO SECTION 2-06.3(1) THE REMOVAL OF SECTIONS OF CURB/GUTTER AND SIDEWALK THAT DO NOT MEET THE OF THE CURRENT STANDARD SPECIFICATIONS, WORKMANSHIP AND AESTHETIC STANDARDS OF THE CITY OF ANACORTES. 5' WIDE X 4' THICK CONCRETE SIDEWALK. 5. SECTIONS OF NEWLY CONSTRUCTED CURB/GUTTER AND SIDEWALK THAT EXHIBIT 5' WIDE X 6" THICK CONC. SIDEWALK AT DRNEWAYS. PER CITY STANDARDS. CRACKING FOLLOWING THE CURING, SHALL BE SUBJECT TO REMOVAL AND REPLACEMENT. CEO-TEXTIIJ_ FABRIC MAY BE REQUIRED DURING CONSTRICTION, DEPENDANT ON CURRENT SOIL CONDITIONS - CRACKING RESULTING FROM SUB-BASE FAILURE OR CONSTRUCTION SITE DAMAGE l WEATHER. GEO-TEXTILE FABRIC SHALL MEET USD0T SPECIFICATIONS 9-33 CONSTRUCTION GEOTEA'ILE SHALL BE IMMEDIATELY REMOVED AND REPLACED TO THE NEAREST EXPANSION JOINT. SHALL ALSO MEET THE VSDOT QUALITY PRODUCTS LIST. - MINOR HAIR LINE STRESS CRACKS MAY, AT THE DISCRETION OF THE PROJECT MANAGER, BE MONITORED AND RE-EVALUATED FOR POSSIBLE REMOVAL AT THE END OF COMPACTION TESTING IS REQUIRED OF ROAD SIJBGRADE AND BALLAST PRIOR TO PLACEMENT OF CRUSHED THE MAINTENANCE PERIOD. SURFACING BY A CERTIFIED SOILS TESTING COMPANY AT A MINIMUM OF 3 RANDOM POINTS ALONG EACH CONTINUOUS SECTION OF ROAD IMPROVEMENT AND BELOW SIDEVAKS. SEE CITY TESTING SCHEDULE. CONTRACTOR IS TO PROVIDE A PROCTER.AND SIEVE ANALYSIS PRIOR T11 ANY CONSTRUCTION STARTING. HERRIGSTAD ENGINEERING & SURVEYING 15TH STREET DATE 4320 WHISTLE FAKE ROAD 2205 15TH STREET SIDEWALK DESIGN DETAILS 10-13-2017 ANACORTES, WA 98221 299-8804 SCALE: PG 2 OF 2 1 NoTE y o ` 9 ' t MMUNITY,&ECONOMIC DEVELOPMENT DEPARTMENT P A ISION /ADDITIONAL INFORMATION COVER SHEET P.rocloy Mailing Address:P.O. Box 547,Anacortes, WA 98221 OCT 2011 Office Location: 904 6th Street,Anacortes WA 98821 l U Phone: (360)299-1984, Fax.• (360)293-1938 CITY OF ANACORTES Please use this form to submit revisions or additional information to your permit application. Permit/Project#: L.D r °G--� / /' —C734- Date: /t Project Name:72 D2_ 75 S%. Project Address: 2.ZO2_ 15-rN Sr Project Contact: 67715ti 4 $j4I/(A'✓ Company Name: I-A 'PEO GA,V72ty Contact Phone: 3G0'753 -9 0 Z f Contact Email: S+'�./e&)a i e4 et7 iry.Coin/ Has the permit been issued yet? 0 Yes ,®. No All revisions must be either clouded or highlighted&wet stamped by an architect/engineer(if applicable). Has this been done? 0 Yes ❑ No Is the plan revision or additional information,in response to a plan review letter? Yes. A copy of the plan review letter with itemized responses to each item is required. 0 No,the revision or additional information is initiated by the applicant,designer,or builder. If not in response to a Plan Review Letter, please explain the nature of the revisions and/or additional information: Are you submitting a full replacement VZYes {" No If not,what page #or title is being replaced: _ Two full sized copies of all revised /additional information is required. Has this been done? 0 Yes ❑ No Check the box next to the type of plan, report, or calculation where revisions or additional information can be found. O Site Plan 0 Building Plans 0 Structural Plan O Landscape Plan 0 Parking Plan 0 Tree Preservation Plan ❑ Arborist Report 0 SEPA checklist ❑ Wetland Report Geotechnical Report Storm Drainage Analysis JK TESC Plan El Civil Plan % Lot Coverage Calculations 0 Impervious Surface Calculations ❑ FAR Calculations ❑ Grading Plan 0 Survey(Boundary/Topographic) ❑ Mechanical Plan 0 Plumbing Plan El Other: i Ii 0 FormtestHistory — ❑ X iiiHVI City of Anacortes Hydrant Maintenance Headquarters Hydrant Test History - Time Time Ports PSI Desired Total Available Hydrant Date Start End Duration Tester used Static Resid. Drop Residual Hydr. Opening Pilot Coefficient GPM GPM @ Desired `1, 378 11/18/1997 Eric 1 90 65 25 20 0 2 1/2 80 0.9 1501 1501 2617 • 0 NIA 0 0.9 0 388 3/2/2004 Comml Fire 1 117 60 57 20 388 4 36 0.71 2034 2034 2710 O N/A 0 0.9 0 LI 393 8/3/2017 10:00 10:10 02 CFP 2 142 115 27 20 393 21/2 37 0.9 1021 2254 5089 0 2 112 54 0.9 1233 403 6/17/2005 Comm_Fire 1 82 29 53 20 403 4 15 0.711 1315 1315 1431 0 NIA 0 0.9 0 403 6/24/2005 Comm_Fire 1 82 48 34 20 403 4 24 0.711 1663 1663 2300 ON/A 0 0.9 0 404 12/21/2004 Comml Fire 1 78 45 33 20 404 4 25 0.71 1695 1695 2298 O NIA 0 0.9 0 406 1/30/2008 14:53 15:00 0.1 CFP 1 73 55 18 20 406 4 10 0_925 1397 1397 2503 I 0 N/A 0 0.9 0 I - • 408 11/8/2000 CFP 1 70 49 21 20 408 4 14 0.9 1608 1608 2569 0 N/A 0 0.9 0 411 3/27/2003 Comml Fire 1 76 60 16 20 411 4 24 0.71 1661 1661 3266 ' O N/A 0 0.9 0 Edit Selected Hydrant J Print List I Close l Record: H 1 105 of 27 1 ► rl 1 T Unfiltered Search i l It 3q3 i 5 Iv/ h 70 A v� 1-4C 1f GOMM LANDED =- GENTRY HOMES AND COMMUNITIES LANDED GENTRY 504 East Fairhaven Avenue Burlington, WA 98233(360) 755-9021 [L;' OCT 042017 { Transmittal Sheet �� ACORTES To: Groc Fyrrce From: Steve Baughn Re: 2202 15th Street—BLD-2017-0349 Date: October 2,2017 Planning, Community&Economic Dev. CC: 0 Urgent ❑ For Review ❑Please Comment ❑ Please Reply 0 Please Recycle Attention: Kait Nelson Re: Responses to the email from Kait Nelson to Groc Fyrrce dated August 31, 2017, regarding the above reference project. • Kait Nelson stated "A soils analysis is necessary to determine the feasibility of infiltration facilities on site. Etc..." Response: Two sets of the "STORM DRAINAGE MEMO", prepared by Ravnik & Associates, Inc., dated September 29, 2017, which includes a Stormwater Infiltration Evaluation, prepared by Geotest, dated August 30, 2017. Said MEMO and Evaluation should address the question of feasibility. Also, there are two sets of revised Erosion Control Plans (both full sized and reduced), along with an updated SWPPP to reflect the changes made to the plans. Please note that the Erosion Control Plan modification are limited to the following: - Revised the title block to clarify the impervious areas and date of revisions. - Removed the originally proposed Rain Garden. - Removed the proposed connection to the public drainage system, as the entire site is designed to infiltrate. - Updated the Typical Downspout Infiltration Trench detail on sheet 2 of 2 • To allow a raingarden, a minimum infiltration rate of... Response: The proposed raingarden has been removes as the soils on the site are conducive to 100% infiltration and there is sufficient area to allow dispersion of the driveway area onsite. • The BMP standards attached to the SWPPP are from the 2005manual. Please use the 2012 manual... The proposed raingarden has been removed as the soils on the site are conducive to 100% infiltration and there is sufficient area to allow dispersion of the driveway area onsite. • There is a discrepancy in the calculations shown on the Erosion Control Plan. The impervious coverage calcs show... The impervious area is a calculation to show the percentage of lot coverage and therefore is limited to the impervious area within the lot. However, for the purposes of the driveway and the dispersion of the runoff from the driveway the calculations in referenced STORM DRAINAGE MEMO do reflect the entire driveway surface. • Pervious surface must be proposed for hard surfaces, excluding roofs, if... See STORM DRAINAGE MEMO,page 2, Driveway Basin. • The design of an infiltration trench that is 6' wide is not a design listed by ... See STORM DRAINAGE MEMO, page 1, House Basin, and page 2, Proposed Infiltration Trench (tight-lined to downspouts). List of items included with this transmittal: (2) Updated Complete Residential Stormwater Plan Checklist — Mininum Requirements 1-5, with Exhibit"A"(written descriptions). (2) Updated the 13 Elements of SWPPP (Construction Stormwater Pollution Prevention Plan),with Exhibits "B" (written descriptions). (2) Revised Erosion Control Plan sheet 1 of 2 and 2 of 2, both full sized and reduced. (2) Storm Drainage Memo, dated September 29, 2017, by Ravnik & Associates, Inc., which includes the Stormwater Infiltration Evaluation, dated August 30, 2017, by Geotest. if 1 SDMH TYPE2 RIM=69,31' INV=63,81' EX. 6°�Cl7NC. SS SLOPE=,005D FT//FT s \j°�-___----- ss �E9. 104�92' E EX. SSMH — — — RIM=70,13' ro INV:61,88' �EGE\D FENCE X X X X— 40' GAS a n UNDERGROUND POWER urn 1 ~ SANITARY fio_. ss RM � � ¢ u- SEWER SD tea: END OF-.. w a WATER �' GUY VIBE cz. A MAIN w X u2N GI w o Power Vault / LLB Catch Basin / w a sanitary Sewer Clean Out X Sanitary Sewer Han Hole ® „ti Fire Hydrant !a / LL Water Gate Valve D� �'� / Water Meter ® EXIST. i Q BUILDING /�_ 1 o 2205 15TH STREET Z- =±�- �� 0,' TOPOGRAPHY SURVEY 1 POWER —� VAULT p� 41 COMPLETE ON JUNE 13, 2017 �7� — mWATER DALE HERRIGSTAD PLS METER /J � SI EWALK � � �.,4 i RA P EDGE OASPHALT END OF 5' < I o SIDEWALK W/ � D r� �Y� SCALE 15TH_ STREET ASPHALT,RAMP i7 1 o _ 15 0 15 30 60 �, > __ 1 - -is..1 D ( IN FEET ) .� zj ' 1 inch = 30 ft. - _ HIRE U Ti HYDRANT !) 1r=-p --,_" HERRIGSTAD ENGINEERING & SURVEYING DATE 4320 WHISTLE LAKE ROAD 2205 15TH STREET FOR LANDED GENTRY 6-13-2017 ANACORTES, WA 98221 299-8804 TOPOGRAPHY SURVEY SCALE: NOTED 8 LECEI1W1 111. OCT 0 5101] CITY OF ANACORTES i September 15, 2017 Qc l,, N1 1 LA, l�r rtovr.✓.ri i� J Anacortes Planning&Community Development Dept. Attn: Groc Fyrrce RE: Plan review corrections for the proposed home/ADU at 2202 15th Street. Please note the following items have been addressed as described: ADU permit is being applied for. r'r tr4Gc.lJcxc --to P X5Te• 'TO ELT. C2! The ADU is indicated on the floor plan on sheet A3.1 Be This plan does not have a concrete slab,therefore it is "not applicable" as the former note stated.L."--- �We do not list specific heat recovery ventilation systems on the plans(the WSEC doesn't require it)L/ due to house and owner variations and specifications. The HVAC contractor and the builder will determine what system will meet the WSEC requirements while addressing owner and house specs. Then that information will be available from the HVAC contractor. It is stated on the plan that the furnace is located in the attic. Specifically where is also determined by the HVAC contractor and builder. [(On sheet A2.1&A4.1 a note now describes the joists overlapping and the nailing required. MK- A bollard is shown and called out on the main floor plan on sheet A3.1. 7(The 4x8 HF#2 floor beams on the ADU side of the building on Sheet A2.1 are indeed adequate. An attached beam calculation shows this. It is calculated using the maximum beam span shown of 5'-3" (technically,4'-11 1/2")."). G8/Sheet A2.2, detail 12 already shows the stair detail with the nosing requirements noted. & Note 11 on sheet A3.1 already calls out the gyp. board type and attachment in the garage where living space occurs above. Both garage/house doors are now noted referring to note 12, addressing 20 min. rated and self- closing hardware. smoke detector and carbon monoxide alarm are now shown on the main floor electrical plan he non-existing code listed in the electrical plan note is now removed. All the above mentioned changes have been "clouded" and labeled with reference "1"for your convenience in finding them. I have included (2)full-sized copies of each changed sheet for your approval. Jack Reinstra Landed Gentry Anacortes Planning& Community Development Dept. Permit Center 14 4 P.O.Box 547,Anacortes,WA 98221-0547 PH(360)293-1901 Don Measamer,Building Official,Planning Director FAX(360)293-1938 August 4, 2017 Jack Reinstra 504 E. Fairhaven Ave Burlington, WA 98233 RE: Plan Review notes for the proposed New Single Family Residence at 2202 15th Street Please address the following items so I can complete the plan review. 1. Please apply for an ADU permit with the necessary documentation with Kait Nelson. 2. Please indicate on floor plans the ADU. 3. Please indicate on the plans that there needs to be R-10 rigid insulation under the entire slab,not just the perimeter,per WSEC Energy Credit la. 4. Please indicate on the plans that the location and what heat recovery ventilation system is being used with the minimum efficiency of 0.85,per WSEC Energy Credit 2c. 5. Please indicate on the plans that the joists need to overlap a minimum of 3 inches over the beams and be nailed together with 3- l Od nails per 2015 IRC R502.6.1. 6. Please indicate on plans that their need to be a bollards in front of the appliances in the garages. 7 en the foundation plan the underfloor beams,that support the joists, are inadequate in the ADU. 10 Please indicate on the stair detail on the plans that the finished nosing of the stairs needs to be 3/4"- 1 1/4" Please indicate on the plans that 5/8"Type X Gypsum Wall Board is required on the ceiling of the garage that has living space above and is required to be screwed off at 6" o.c.in the field as well as on the edges. 10. Please indicate on the plans that both garage doors need to be 20-minute fire-rated with self-closing devices. 11. Please indicate on 1st floor electrical plan, of the larger residence, that there needs to be both a smoke detector and a carbon monoxide alarm. 12. There is a note on the Electrical Plan that quotes a non-existing code. Please replace it with the correct one, which is the amended Mechanical Chapter of the 2015 IRC. Please contact me if you have any questions about these notes. Sincerely, Groc Fyrrce Building Inspector ' l o ) 7 1 �� CJ r,-.... City of Anacortes V `�® ``� 360-293-1901 G17C Y. o� PLANNING, COMMUNITY, &ECONOMIC DEVELOPMENT DEPARTMENT i PLAN REVISION /ADDITIONAL INFORMATION COVER SHEET \,P?. n'`, Mailing Address: P.O. Box 547, Anacortes, WA 98221 •: coi Office Location: 904 6th Street, Anacortes WA 98821 Phone: (360) 299-1984, Fax: (360)293-1938 Please use this form to submit revisions or additional information to your permit application. Permit/Project#: -20( 7 - O!49 Date: — `J - i-1 Project Name: Project Address: ' .202 I £5T44 STRe--8T Project Contact: UAL>It& f2. I\tSTt Company Name: L � -D n et ___ d CT-4-0ra�r i I N G Contact Phone: . ,670=[S 5 Contact Email: Has the permit been issued yet? 0 Yes lg'No All revisions must be either clouded or highlighted &wet stamped by an architect/engineer(if applicable). Has this been done? ,J ('Yes 0 No Is the plan revision or additional information, in response to a plan review letter? OCT 0 4 2011 fit, Yes. A copy of the plan review letter with itemized responses to each item is required. ❑ No, the revision or additional information is initiated by the applicant,designer,or builder. GI I Y OF MACON Q Ea If not in response to a Plan Review Letter, please explain the nature of the revisions and/or additional information: Are you submitting a full replacement r Yes I No If not,what page#or title is being replaced: A .I h3. ( A C.1- I t I . Two full sized copies of all revised /additional information is required. Has this been done? n Yes ❑ No Check the box next to the type of plan, report, or calculation where revisions or additional information can be found. Site Plan l f, Building Plans ❑ Structural Plan [� Landscape Plan ❑ Parking Plan ❑ Tree Preservation Plan ❑ Arborist Report ❑ SEPA checklist 0 Wetland Report O Geotechnical Report p, Storm Drainage Analysis ❑ TESC Plan ❑ Civil Plan 0 Lot Coverage Calculations ❑ Impervious Surface Calculations ❑ FAR Calculations 0 Grading Plan ❑ Survey(Boundary/Topographic) O Mechanical Plan 0 Plumbing Plan 0( Other: A C) Pe r`-'1 I1 Nelson, Kait From: Franz, John Sent: Wednesday, August 16, 2017 11:54 AM To: Nelson, Kait Cc: Grage, Libby; Measamer, Don; Lange, Steve; Hohmann, Tim; Symonds,Justin Subject: Lots subject to MR 1-5 Kait and I reviewed a project proposal for a single family residence The site is subject to MR 1-5.The developer proposed 3336 square feet impervious going to an infiltration trench, and 1236 square feet impervious surface draining into a rain garden. The design for the infiltration trench assumed sandy loam soil. Following the stormwater manual design guidelines resulted in an infiltration trench 2'wide by 250' long.A 250' long infiltration trench is obviously not feasible,the developer recognized the infeasibility and so a 6' wide trench by 84' long was proposed. Since this results in the same number of square feet of trench it seems like a reasonable approach; however is not a design that is specifically authorized by the Stormwater Manual.To determine if a trench 6'wide is acceptable I called Doug Howie,an Ecology Stormwater Engineer. Ecology will accept infiltration trenches wider than the standard 2' design in the manual, however these pose a couple of additional requirements: 1. The square foot print must be the same as the square feet requirement determined with the 2' wide design. 2. The soils and infiltration rate must be verified by a professional. 3. A header system and multiple perforated pipes must be installed in the trench, ie. a 6' trench will require a three pipe drain system. 4. Due to the potential for water mounding a greater distance from the trench bottom is required.A 6' system will require 5' from the bottom of the trench to the seasonal high water table. 5. Due to mounding potential and known ground water issues in Anacortes modifications to infiltration trench design must be done by a qualified professional. To clarify rain garden requirements the following guidelines should be followed: 1. Anacortes has known soil and high ground water table issues: a. When a rain garden is being designed using dry weather data (May 15t to September 30th) a qualified professional must perform a soils analysis b. If soils testing is proposed during wet weather(October 1st to April 30)the pit test identified in the Rain Garden Manual can be used. 2. While the Rain Garden Manual can be used,specifications from the Stormwater Manual (2012 edition amended in 2104) must be followed. If there is a difference in the design specifications the requirements of the Stormwater Manual take precedence. Refer to BMP T7.30: Bioretention Cells, Swales,and Planter Boxes. John Franz City of Anacortes Stormwater Coordinator Office 360-299-1966 Cell 360-661-3747 1 ' SDMH TYPE2 RIM=69,31' INV=63,81' tt ss ss u EX. 6' CONC. SS SLOPE=90K6 FT/FT I ss 169 10 2' E N. EX. SSMH — — —max---fit x Z. ® RIM=7013' tI INV;61.88' LEGEND FENCE —X X X X— x �I\ 40' GAS G x UNDERGROUND LID, Z POWER i3 SANITARY ss zx m SEWER '70 Y ¢z STORM a J 4 6 SEWER SD COoix END OF 3 uma WATER COGUY WIFE -y j W'z MAIN v X in �\w ti Power Vault n ,� W Catch Basin Q" L' N Sanitary Sewer Clean Out 0 z Sanitary Sewer Man Hole Fire Hydrant P. _ 1� Water Gate Valve DG Water Meter ® EXIST. Q BUILDING / -----., 2205 15TH STREET ---l2' N. ^ TOPOGRAPHY SURVEY 104.92' s VAULT P COMPLETE ON JUNE 13, 2017 ---73 m -- METER DALE HERRIGSTAD PLS ��� fI RA PWALK \s--74-------_ EDGE�FJASPHALT END OF 5' IDEWALK W/ 15TH STREET PHALT RAMP SIDE l GRAPHIC SCALE - - - - `M 15 0 15 30 60 ( Di FEET ) \\N. 1 inch = 30 ft. FIRE a HYDRANT HERRIGSTAD ENGINEERING & SURVEYING DATE 4320 WHISTLE LAKE ROAD 2205 15TH STREET FOR LANDED GENTRY 6-13-2017 ANACORTES, WA 98221 299-8804 TOPOGRAPHY SURVEY SCALE: t D rice PLANNING,COMMUNITY,&ECONOMIC DEVELOPMENT DEPARTMENT ♦ Y ra P I d LAIMIL.4% Mailing Address:PO Box 547, Anacortes,WA 98221 �� I Phone: 360.299.1984, Fax: 360,293.1938 �+ ' �. w Complete Residential Stormwater Plan Checklist Minimum Requirements 1-5 Stormwater requirements are based on the 2012 Stormwater Management Manual for Western Washington (SWMMWW).A link is provided on the City of Anacortes website,under Planning Department,Stormwater Regulations,as well as under the Engineering Division of Public Works. Residential construction is exempt from additional stormwater provisions if it involves no expansion of hard surfaces, no use beyond that previously existing,and results in no significant adverse hydrological impact. Building permit applications for lots that are part of a subdivision that was recorded no more than 10 years prior to the date of the complete building permit application may continue to use the stormwater codes in effect at the time the subdivision application was submitted,if stormwater was addressed at the subdivision/plat level. If construction has not started as of January 1, 2022, the site will be subject to the 2012/2014 manual. If your project adds less than 2,000 sq.ft.of new plus replaced hard surface area,AND which disturbs less than 7,000 square feet of land,you must consider all 13 Elements of the Construction Stormwater Pollution Plan (SWPPP). Fill out the SWPPP Checklist and explain how the elements are considered, or describe how site conditions render the element unnecessary and the exemption from that element is clearly justified.You will not need to continue with this document. If your project adds 2,000 sq.ft. or more of new plus replaced hard surface area, OR which disturbs 7,000 sq.ft. or more of land-Minimum Requirements 1-5 of the SWMMWW apply,and you can continue with this document.If adding 5,000 sq.ft.or more of new hard surfaces/OR converting 32,670 sq. ft,or more of vegetation to lawn or landscaped area/OR converting 108,900 sq.ft.or more of native vegetation to pasture—Minimum Requirements 1-9 of the SWMMWW apply. If Minimum requirements 1-9 apply, please see the Large Scale Stormwater Plan Checklist for additional submittal requirements. Owner Name: fgED C • /1-c21--TO%-4 Site Address: 2.,2-0 2- I t J . Brief Description of the Project: Pre Developed Conditions&Runoff of the Site: Page 1 of 4 March 22, 2017 Developed Conditions&Runoff of the Site: Summarize difficult site parameters,the natural drainage system,and drainage to and from adjacent properties, including bypass flows: D Hydrological Site Plan:Collect and analyze information on existing conditions to aid in determining low impact development feasibility—which locations are most appropriate to evaporate,transpire,and infiltrate,with the following information: o Survey by Land Surveyor, Engineer,or other qualified professional:Show existing public and private development, utility infrastructure, hydrological features(seeps, springs,closed depression areas,drainage swales, streams, wetlands,and water body survey and classification report showing wetland and buffer boundaries),flood hazard areas,geological hazards, buffers, aquifer and wellhead protection areas,topographic features that may act as natural stormwater storage, infiltration,or conveyance. Include the natural receiving waters that stormwater runoff will either directly or eventually discharge.Show topography, display acreage and outlines of all drainage basins;existing stormwater drainage to and from the site; routes to existing, construction,and future flows at all discharge points; and the length of travel from the farthest upstream end of a proposed storm drainage system to any proposed flow control and treatment facility. Identify areas of potential erosion problems Show contours as follows: • Up to 10%slopes=2 ft.contours • Over 10%to less than 20%slopes=5 ft. contours • 20%or greater slopes= 10 ft.contours • Elevations at 25 ft. intervals o Soils Report:Done by a soil scientist certified by Soil Science Society of America, licensed sewage designer, or other suitably trained persons working under the supervision of a professional engineer,geologist, hydrologist, or any other professional supervised by an engineering geologist registered in Washington State. (Soils Report Page 2 of 4 March 22,2017 must include details as listed on Pg.79). In addition, describe soils by name,erodibility, settleability, permeability,depth,texture, and soil structure. Testing should occur between December 1 and April 1. o Soils Map: Based on the report. o Preliminary Development Site Plan Layout: Locate proposed buildings, roads, parking lots, landscaping features,on-site stormwater management BMPS(Determine BMPs starting on Pg. 95.Suggested BMPs correlate with responses to the 13 elements of the SWPPP, Pg. 237,and preliminary location of stormwater treatment and retention/detention facilities.Considerations are on Pg. 83.These methods could reduce required facility sizes, but are not required for approval.Show existing and proposed contours, show all cut and fill slopes indicating top and bottom of slope catch lines,and identify developed condition drainage basins. o Survey of existing native vegetation cover:This is only required if there are native soil and vegetation protection areas proposed for the site.Survey shall be done by a licensed architect, arborist, qualified biologist or project proponent identifying any forest areas on the site and a plan to protect those areas.The preserved area should be placed in a separate tract or protected through recorded easements for individual lots. o Vicinity Map:Clearly locate the property, identify all roads bordering the site,show the route of stormwater off-site to the local natural receiving water, and show significant geographic features and sensitive/critical areas (streams, wetlands, lakes, steep slopes, etc). 0 Construction Stormwater Pollution Prevention Plan(SWPPP)—The SWPPP shall be implemented beginning with initial land disturbance and until final stabilization. From October 1 through April 30,clearing,grading, and other soil disturbing activities shall only be permitted if shown that silt-laden runoff will be prevented from leaving the site through methods listed on pg. 44. Best Management Practices (BMPs)Standards and Specifications are listed on pg. 261. Please see pg. 230 for details on using the Site Analysis to produce the following materials: o Narrative: Explain and justify the pollution prevention decisions made.This will contain concise information concerning existing site conditions, construction schedules, wet season construction activity,constraints, and other pertinent items that are not contained-on-the drawings-.—This based on the 13 Construction Elements,which must be considered unless site conditions render the element unnecessary and the exemption is clearly justified. Elements listed on pg. 44& described in detail starting on pg. 236. o Drawings&Notes: Where and when the BMPs should be installed,the performance the BMPs are expected to achieve,and actions that will be taken if the performance goals are not achieved. Show water quality monitoring locations. o Special Reports&Studies: Include any studies(i.e.wetlands delineation). If a facility is required and feasible for Minimum Requirement 5, a PIT Test must be done in the location that the facility location is proposed based on the preliminary development site plan layout. 0 Other permits:Any other necessary permits as required by other regulatory agencies. Identify if those permits include conditions that affect the drainage plan, or contain more restrictive drainage-related requirements. Prior to Final Stormwater Inspection 0 Permanent Stormwater Control Plan Drawing: Select BMPs based on the Preliminary Development Site Plan Layout from the Site Analysis Summary. Provide a scale drawing of the Page 3 of 4 March 22, 2017 lot(s)and any public ROW that displays the location of On-Site BMPs and the areas served by them. These documents will be recorded and attached to a declaration of covenant and grant of easement associated with each lot that includes On-site BMPs. Provide design details,figures, and maintenance instructions for each BMP. Provide a written summary of how it complies with the applicable requirements. Prior to Final Occupancy ❑ Operation&Maintenance Manual: Include a manual for each flow control and treatment facility, including any distributed bioretention facilities that are used to help meet flow control and/or treatment requirements.The manual shall include a description of the facility,what it does,and how it works. It must also identify and describe the maintenance tasks,and the frequency of each task. The tasks and frequencies must meet the standards of the SWMMWW. Include a maintenance activity log that will indicate what actions will have been taken and where it should be kept and made available for inspection by the City. ❑ Declaration of Covenant for Privately Maintained irl w Control RA Treatment Facilities and On- Site Storrnwater Management BMPs:Any flow control &treatment facilities and On-Site Stormwater management BMPs for which the applicant identifies operation&maintenance to be the responsibility of a private party must have a declaration of covenant and grant of easement.After City approval, the declaration of covenant and grant of easement must be signed and recorded. Design details, figures, and maintenance instructions for any BMP shall be attached. A map showing the location of newly planted and retained trees claimed as flow reduction credits shall also be attached. Q Record? Documents: Record total impervious surface area of the site and their locations with the county auditor. By signing below,you are certifying that you have read and understand the storriwater requirements. Be sure that you have checked off all applicable boxes. 1 —, ,‘------- 4V_3L_______ ze)/: / /. / __, Ap icant Signature D,elte- ` n g3 g%\\V %W,',, oC-r45201N :s ES Gil v or ',,' . Page 4 of 4 March 22, 2017 W - 01 11 `Wi 11 41 4! EXHIBIT ` A" . ' OCT 05 2017 . y Lu 2202 15TH STREET CITY OF ANACORTES P56250 Responses to the "Complete Residential Stormwater Plan Checklist® Minimum Requirements 1-5". Brief Description of the Project: To construct one Single-Family Residence (SFR) on a single legal lot within the City of Anacortes. The existing lot size is 10,475 square feet and the current Zone is R2. Pre Developed Conditions & Runoff on the Site: The property has an existing shed structure of wood frame and metal siding. The size of the structure is approximately 960 square feet. The existing shed is to be removed. The site slopes at from the southeast to the northwest at a grade between 3% and 4%. The property is bounded as follows: NORTH: An existing public alley. EAST: The public Right of Way of"D" Avenue, with full improvements. South: The public Right of Way of 15th Street, with asphalt pavement only. West: An existing single-family residence, 2204 15th Street. Developed Conditions & Runoff of The Site: The proposed improvements are as follows: Construct a SFR with an approximate lot coverage of 28.7% and an impervious lot coverage of 37.8%. A roof drain infiltration system is proposed along the northerly portion of the site. Landscaping will be provided to permanently stabilize the site from erosion. Per "STORM DRAINAGE MEMO", prepared by Ravnik & Associates, Inc., dated September 29, 2017, 100% of the stormwater runoff will be infiltrated onsite, including that portion of the proposed driveway located within the public right-of-way. Frontage improvements will be designed and constructed along 15t" Street to City of Anacortes specifications. Improvements will consist of at least the construction of a concrete curb and gutter, driveway apron, and a pedestrian sidewalk transition, along with any additional paving required for half street improvements. Any public drainage requirement within 15th Street will be determined by the design engineer. Summarize difficult site parameters, the natural drainage system, and drainage to and from adtacent properties, including bypass flows: The site slopes at from the southeast to the northwest at a grade between 2% and 3% is grass covered, and flows toward an existing alley along the north property line. From the alley the existing surface flow, if any, would continue northerly through the private properties of 2209 and 2205 14th Street. Once the improvements are completed as described herein, said flow to the 14t" Street properties, if any, will be reduce or eliminated. The only tributary drainage the site receives is from a portion of 15th Street. Said tributary drainage will be addressed by the engineer who will design the street frontage improvements along 15th Street. Hydrological Site Plan: Survey: A topographic survey has been performed by Herrigstad Engineering, showing the existing improvements around and within the subject property, along with the existing contours at 1-foot intervals. Soils Report: A soils investigation was performed by Geotest Services, Inc. on June 27th, 2017. The results of said soils investigation is attached in the Stormwater Infiltration Evaluation, dated August 30, 2017, and is included within the "STORM DRAINAGE MEMO", prepared by Ravnik & Associates, Inc., dated September 29, 2017, included herewith. Preliminary Development Site Plan Layout: A "Site Plan" has been prepared by Landed Gentry Development, Inc., showing both the existing and proposed improvements as requested, along with an "Erosion Control Plan & LID Improvement Plan". See attached. A "Survey of existing native vegetation cover" was performed by the project proponent and found not forested areas on the site. A "Vicinity Map" has been provided on Sheet 2 of 2 of the "Erosion Control & LID Improvement Plan", attached. Construction Stormwater Pollution Prevention Plan (SWPPP): See attached EXHIBIT "B". Other Permits: A Right-of-Way Permit will be required from the City of Anacortes for the frontage improvements along 15th Street. A demolition permit will be required to remove the existing shed structure on the project site. •�c Y 0 Planning, Community, & Economic Development Department PO Box 547, Anacortes, WA 98221 PH: 360.299.1984 " °�� ‘�q ro�� 13 Elements of SWPPP (Construction Stormwater Pollution Prevention Plan) Please check off boxes to show that each element has been read and understood. Provide details where applicable and if certain aspects are unnecessary or exempt, clearly justify. Details of the 13 Elements and the correlating BMPs are listed on Pg. 236 of the 2014 Stormwater Management Manual for Western Washington (SWMMWW). A link is provided on the City of Anacortes website, under Planning, Community, & Economic Development Department,as well as under Stormwater on the Engineering Division of Public Work's page. Owner Name: FrrZeP 101m 0 )0)NRRI-ITTR Site Address: 2 2.C72_, 13 -0 S , r OCT 0 5 2017 11 . Prepared By: I- 4-tJOW GjEforg VEL&'1 fE The Stormwater checklist or building permit determined that: ❑ The 13 elements must be addressed for ; i These elements must be addressed for construction activity adding under 2,000 construction activity adding 2,000 sq. ft. sq. ft.of hard surface area. or more of hard surface area. This means that an attached narrative and site plan are required with this document. Under each element, explain the best management practices (BMPs) used or justify reasoning for those-that will not be used: if needed, please attach a-narrative to further explain plans or justification. ELEMENT 1: Preserve Vegetation/Mark Clearing Limits ❑ Before beginning land disturbing activities, including clearing and grading,clearly mark all clearing limits, sensitive areas and their buffers, and trees that are to be preserved within the construction area. ❑ Retain the duff layer, native top soil, and natural vegetation in an undisturbed state to the maximum degree practical. Page 1 of 8 March,2017 ELEMENT 2: Establish Construction Access ❑ Limit construction vehicle access and exit to one route, if possible. ❑ Stabilize access points with a pad of quarry spalls,crushed rock,or other equivalent BMPs,to minimize tracking onto roads. ❑ Locate wheel wash or tire baths on site, if the stabilized construction entrance is not effective in preventing tracking sediment onto roads. ❑ If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day, or more frequently as necessary(ex:wet weather). Remove sediment from roads by shoveling, sweeping, or pick up and transport the sediment to a controlled sediment disposal area. ❑ Conduct street washing only after sediment is removed in accordance with the above bullet. ❑ Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tributary to waters of the State. �E Txl4f B/r LC6-._&45,07- ELEMENT 3: Control Flow Rates ❑ Protect properties and waterways downstream of development sites from erosion and the associated discharge of turbid waters due to increases in the velocity and peak volumetric flow rate of stormwater runoff from the project site. ❑ Where necessary to comply with the bullet above, construct stormwater retention or detention facilities as one of the first steps in grading. Assure that detention facilities function properly before constructing site improvement (e.g. impervious surfaces). ❑ If permanent infiltration ponds are used for flow control during construction,protect these facilities from siltation during the construction phase. ELEMENT 4: Install Sediment Controls O Design, install, and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. ❑ Construct sediment control BMPs(sediment ponds,traps,filters,etc.) as one of the first steps in grading.These BMPs shall be functional before other land disturbing activities take place. ❑ Minimize sediment discharges from the site.The design, installation and maintenance of erosion and sediment controls must address factors such as the amount, frequency, intensity and duration of precipitation,the nature of resulting stormwater runoff, and soil characteristics, including the range of soil particle sizes expected to be present on the site. ❑ Direct stormwater runoff from disturbed areas through a sediment pond or other appropriate sediment removal BMP, before the runoff leaves a construction site or before discharge to an Page 2 of 8 March, 2017 infiltration facility. Runoff from fully stabilized areas may be discharged without a sediment removal BMP, but must meet the flow control performance standard in Element#3, bullet#1. 0 Locate BMPs intended to trap sediment on-site in a manner to avoid interference with the movement of juvenile salmonids attempting to enter off-channel areas or drainages. ❑ Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal, and maximize stormwater infiltration. ❑ Where feasible,design outlet structures that withdraw impounded stormwater from the surface to avoid discharging sediment that is still suspended lower in the water column. ,ELE1s4E'nl Y 4 ELEMENT 5: Stabilize Soils ❑ Stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. Applicable BMPs include, but are not limited to:temporary and permanent seeding, sodding, mulching, plastic covering,erosion control fabrics and matting, soil application of polyacrylamide (PAM),the early application of gravel base early on areas to be paved, and dust control. O Control stormwater volume and velocity within the site to minimize soil erosion. ❑ Control stormwater discharges, including both peak flow rates and total stormwater volume,to minimize erosion at outlets and to minimize downstream channel and stream bank erosion. ❑ Soils must not remain exposed and unworked for more than the time periods set forth below to prevent erosion. o During the dry season(May 1—Sept 30): 7 days o During the wet season (Oct 1—Apr 30): 2 days ❑ Stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather forecast. O Stabilize soil stockpiles from erosion, protect with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. ❑ Minimize the amount of soil exposed during construction activity. ❑ Minimize the disturbance of steep slopes. ❑ Minimize soil compaction and, unless infeasible, preserve topsoil. -� Fx i 6 J i ,t5rl / ,E(iE,A46,jt1)-- 5 . ELEMENT 6: Protect Slopes ❑ Design and construct cut-and-fill slopes in a manner to minimize erosion. Applicable practices include, but are not limited to, reducing continuous length of slope with terracing and diversions, reducing slope steepness,and roughening slope surfaces (Ex:track walking). Page 3 of 8 March, 2017 0 Divert off-site stormwater(run-on) or ground water away from slopes and disturbed areas with interceptor dikes, pipes, and/or swales. Off-site stormwater should be managed separately from stormwater generated on the site. 0 At the top of slopes,collect drainage in pipe slop drains or protected channels to prevent erosion. o *Temporary pipe slope drains must handle the peak volumetric flow rate calculated using a 10-minute time step from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively,the 10-year, 1-hour flow rate predicted/indicated by an approved continuous runoff model, increased by a factor of 1.6, may be used.The hydrologic analysis must use the existing land cover condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis must use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. If using the Western Washington Hydrology Model (WWHM)to predict flows, bare soil areas should be modeled as "landscaped" area. o Where 15-minute time steps are available in an approved continuous runoff model,they may be used directly without a correction factor. ❑ Place excavated material on the uphill side of trenches, consistent with safety and space considerations. ❑ Place check dams at regular intervals within constructed channels that are cut down a slope. ❑ Consider soil types and its potential for erosion. ❑ Stabilize soils on slopes, as specified in Element 5. ❑ BMP combinations are the most effective method of protecting slopes with disturbed soils. Ex: Use both mulching and straw erosion control blankets. x r�)7- "J'') ELEMENT 7: Protect Drain Inlets ❑ Protect all storm drain inlets made operable during construction so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. ❑ Clean or remove and replace inlet protection devices when sediment has filled one-third of the available storage (unless a different standard is specified by the product manufacturer). ❑ Where possible, protect all existing storm drain inlets so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. ❑ Keep all approach roads clean. Do not allow sediment and street wash water to enter storm drains without prior and adequate treatment unless treatment is provided before the storm drain discharges to waters of the State. ❑ Inlets should be inspected weekly at a minimum and daily during storm events. EX hrS IT !� jj`` c i�Ie, Jr' , Page 4of8 March, 2017 ELEMENT 8:Stabilize Channels and Outlets ❑ Design, construct, and stabilize all on-site conveyance channels to prevent erosion from the following expected peak flows: o *Channels must handle same peak volumetric flow rate as temporary pipe slope drains listed in Element 6,above. ❑ Provide stabilization, including armoring material,adequate to prevent erosion of outlets, adjacent streambanks,slopes, and downstream reaches at the outlets of all conveyance systems. ❑ The best method for stabilizing channels is to completely line the channel with a blanket product first,then add check dams as necessary to function as an anchor and to slow the flow of water. ELEMENT 9: Control Pollutants ❑ Design, install,implement,and maintain effective pollution prevention measures to minimize the discharge of pollutants. ❑ Handle and dispose of all pollutants, including waste materials and demolition debris that occur on-site in a manner that does not cause contamination of stormwater. ❑ Provide cover, containment, and protection from vandalism for all chemicals, liquid products, petroleum products,and other materials that have the potential to pose a threat to human health or the environment.On-site fueling tanks must include secondary containment. Secondary containment means placing tanks or containers within an impervious structure capable of containing 110%of the volume contained in the largest tank within the containment structure.Double-walled tanks do not require additional secondary containment. ❑ Conduct maintenance, fueling,and repair of heavy equipment and vehicles using spill prevention and control measures. Clean contaminated surfaces immediately following any spill incident. ❑ Discharge wheel wash or tire bath wastewater to a separate on-site treatment system that prevents discharge to surface water, such as closed-loop recirculation or upland land application,or to the sanitary sewer,with local sewer district approval.Wheel wash or tire bath wastewater should not include wastewater from concrete washout areas. ❑ Apply fertilizers and pesticides in a manner and at application rates that will not result in loss of chemical to stormwater runoff. Follow manufacturers' label requirements for application rates and procedures. ❑ Use BMPs to prevent contamination of stormwater runoff by pH-modifying sources. The sources for this contamination include, but are not limited to: bulk cement,cement kiln dust,fly ash, new concrete washing and curing waters, waste streams generated from concrete grinding and sawing, exposed aggregate processes,dewatering concrete vaults, concrete pumping,and mixer washout waters.Adjust the pH of stormwater if necessary to prevent violations of the water quality standards. Page 5 of B March, 2017 D Assure that washout of concrete trucks is performed off-site or in designated concrete washout areas only. Do not wash out concrete trucks onto the ground,or into storm drains, open ditches, streets,or streams. Do not dump excess concrete on site,except in designated concrete washout areas.Concrete spillage or concrete discharge to surface waters of the State is prohibited. Do not use upland land applications for discharging wastewater from concrete washout areas. ❑ Obtain written approval from Ecology and provide to the City before using chemical treatment other than CO2 or dry ice to adjust pH. ❑ Woody debris may be chopped and spread on site. ❑ Conduct oil changes, hydraulic system drain down,solvent and de-greasing cleaning operations, fuel tank drain down and removal,and other activities which may result in discharge or spillage of pollutants to the ground or into stormwater runoff using spill prevention measures,such as drip pans. ❑ Clean contaminated surfaces immediately following any discharge or spill incident. Emergency repairs may be performed on-site using temporary plastic placed beneath and, if raining, over the vehicle. L-5Eg- X 1--iJ P 7 " ;d . c�FlwlCAI / ELEMENT 10: Control De-Watering ❑ Discharge foundation,vault, and trench dewatering water,which have characteristics similar to stormwater runoff at the site, into a controlled conveyance system before discharge to a sediment trap or sediment pond. ❑ Discharge clean, non-turbid de-watering water, such as well-point ground water,to systems tributary to,or directly into surface waters of the State,as specified in Element 8, provided the de-watering flow does not cause erosion or flooding of receiving waters or interfere with the operation of the system. Do not route clean dewatering water through stormwater sediment ponds. Note that"surface waters of the State" may exist on a construction site as well as off site; for example,a creek running through a site. D Handle highly turbid or contaminated dewatering water separately from stormwater. ❑ Other treatment or disposal options may include: 1. Infiltration 2. Transport off-site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner that does not pollute state waters. 3. Ecology-approved on-site chemical treatment or other suitable treatment technologies. 4. Sanitary or combined sewer discharge with local sewer district approval, if there is no other option. 5. Use of a sedimentation bag with outfall to a ditch or swale for small volumes of localized dewatering. ❑ Construction equipment operation,clamshell digging, concrete tremie pour, or work inside a cofferdam can create highly turbid or contaminated dewatering water. ❑ Discharging sediment-laden (muddy)water into waters of the State likely constitutes a violation Page 6of8 March, 2017 of water quality standards for turbidity.The easiest way to avoid discharging muddy water is through infiltration and preserving vegetation. Y-1tB/7- r`Jj -i 1, j Fcpwg,t/i ELEMENT 11: Maintain BMPs ❑ Maintain and repair all temporary and permanent erosion and sediment control BMPs as needed to assure continued performance of their intended function in accordance with BMP specifications. El Remove all temporary erosion and sediment control BMPs within 30 days after achieving final site stabilization or after the temporary BMPs are no longer needed.Some temporary erosion and sediment control BMPs are bio-degradable and designed to remain in place following construction such as compost socks. ❑ Provide protection to all BMPs installed for the permanent control of stormwater from sediment and compaction.All BMPs that are to remain in place following completion of construction shall be examined and placed in full operating conditions. If sediment enters the BMPs during construction, it shall be removed and the facility shall be returned to the conditions specified in the construction documents. ❑ Remove or stabilize trapped sediment on site. Permanently stabilize disturbed soil resulting from removal of BMPs or vegetation. -� �)(016j T I(/ `I) EvFt4 J I /J ELEMENT 12: Manage the Project-Projects subject to Minimum Requirements 1-9 must have a Certified Erosion and Sediment Control Lead (CESCL)for site inspections. Projects subject to Minimum Requirements 1-5 do not require the inspector to be certified. By the initiation of construction, the SWPPP must identify the CESCL or inspector,who shall be present on-site or on-call at all times. Management details starting on lig. 250. ❑ Phase development projects to the maximum degree practicable and take into account seasonal work limits to prevent soil erosion and prevent transporting sediment from the site during construction. El Inspection and monitoring-Inspect, maintain, and repair all BMPs as needed to assure continued performance of their intended function. ❑ Maintain, update, and implement the SWPPP. ❑ Clearing and grading activities for developments shall be permitted only if conducted using an approved site development plan (e.g., subdivision approval). ❑ From Oct 1 through Apr 30,clearing,grading,and other soil disturbing activities is permitted only if shown that the site operator will prevent silt-laden runoff from leaving the site through a combination of the following: Page 7 of 8 March, 2017 1. Site conditions including existing vegetative coverage, slope, soil type, and proximity to receiving waters. 2. Limit activities and the extent of disturbed areas. 3. Proposed erosion and sediment control measures. Weather conditions can influence the seasonal limitation on site disturbance.The City of Anacortes has the authority to take enforcement action per AMC 19.76 Stormwater. 0 The following activities are exempt from the seasonal clearing and grading limitations: 1. Routine maintenance and necessary repair of erosion and sediment control BMPs; 2. Routine maintenance of public facilities or existing utility structures that do not expose the soil or result in the removal of the vegetative cover to soil 3. Activities where there is 100%infiltration of surface water runoff within the site in approved and installed erosion and sediment control facilities. ELEMENT o Protect Low Impact Development BMPS L If implementing any bioretention facilities or rain gardens, see Pg. 25? for requirements. ti / d Applicant Signature Dot l\\:\11 \\4 \\\ ocT t15 IV C1�Y c* �NICOFt1E� Page 8 of 8 March, 2017 EXHIBIT "B" 2202 15TH STREET IrglE117 P56250cr ? Responses to the CITY OF ANACORTES "13 Elements of SWPPP" (Construction Stormwater Pollution Prevention Plan) ELEMENT 1: Preserve Vegetation/Mark Clearing Limits The clearing limits will be marked by using either BMP C233: Silt Fence, or BMP C103: High Visibility Plastic or Metal Fence, as shown on the Erosion Control Plan. C233 is to be used along the west and north property lines and the C103 along the east and south property lines. Preservation of the native top soil will be preserved as much as is practical by use of a stock pile as shown on the Erosion Control Plan. Stock pile location may vary. Stock pile shall be protected as indicated on the Erosion Control Plan. ELEMENT 2: Establish Construction Access BMP C105 shall be used as the construction access. Only one access point is proposed, however, during construction of the sanitary sewer service installation, access along the alley will be necessary. No wheel wash is proposed. Any track out shall be cleaned daily by shoveling and/or sweeping. More frequent cleaning as necessary. ELEMENT 3: Control Flow Rates Flow rates shall be controlled by dispersion of hard surface runoff onto pervious surface, and the installation of a downspout infiltration system, sized to accommodate the entire roof area. ELEMENT 4: Install Sediment Controls The following BMPs are proposed as temporary sediment controls: C233: Silt Fence To be place along the perimeter of the site to protect downstream properties from the transport of coarse sediment, as well as to mark the clearing limits for the construction crew and to alert the public as to the potential dangers of the ongoing onsite construction activity. C105: Stabilized Construction Entrance To be place in the location of the future driveway on 15th Street, to provide a stable and clean point of access for construction vehicles. C121: Mulching To provide immediate temporary protection of exposed soil from erosion, as well as conserving moisture. C123: Plastic Covering Primarily used to protect the stock pile from erosion. May be used as a short term cover of small areas of exposed soil. Not intended for large areas. C140: Dust Control As this project will be constructed during the dry season, dust control may be necessary to protect the surrounding neighborhood. The primary source of dust control will be controlled spraying of the disturbed area with water. C220: Storm Drain Inlet Protection Onsite inlet protection will use Block & Gravel Curb Inlet Protection. Offsite inlet protection will use Catch Basin Filters manufactured for use at construction sites. C207: Check Dams Where drainage swales may be created to convey stormwater, temporary gravel check dams may be used to reduce velocity and to dissipate flow energy. The following BMP and LID improvements are proposed for permanent sediment controls: T5.10A: Downspout Full Infiltration A Downspout Infiltration Trench is to be installed per Figure III-3.1.2, Typical Downspout Infiltration Trench, modified per detail on Sheet 2 of 2 of the Erosion Control Plan & LID Improvement Plan and per said Storm Drainage Memo. ELEMENT 5: Soil Stabilization The following are temporary soil stabilization BMPs: C233: Silt Fence To be place along the perimeter of the site to protect downstream properties from the transport of coarse sediment, as well as to mark the clearing limits for the construction crew and to alert the public as to the potential dangers of the ongoing onsite construction activity. C105: Stabilized Construction Entrance To be place in the location of the future driveway on 15th Street,to provide a stable and clean point of access for construction vehicles. C121: Mulching To provide immediate temporary protection of exposed soil from erosion, as well as conserving moisture. C123: Plastic Covering Primarily used to protect the stock pile from erosion. May be used as a short term cover of small areas of exposed soil. Not intended for large areas. C140: Dust Control As this project will be constructed during the dry season, dust control may be necessary to protect the surrounding neighborhood. The primary source of dust control will be controlled spraying of the disturbed area with water. C220: Storm Drain Inlet Protection Onsite inlet protection will use Block & Gravel Curb Inlet Protection. Offsite inlet protection will use Catch Basin Filters manufactured for use at construction sites. C207: Check Dams Where drainage swales may be created to convey stormwater, temporary gravel check dams may be used to reduce velocity and to dissipate flow energy.The following are permanent soil stabilization BMPs: C124: Sodding Establishes permanent turf for immediate erosion protection. C125: Top Soiling Provides a suitable growth medium for final site stabilization with vegetation. T5.13: Post-Construction Soil Quality and Depth Establishes soil quality and depth regains greater stormwater functions in the post development landscape, provides increased treatment of pollutants and sediments that result from development and habitation. ELEMENT 6: Protect Slopes No slopes over 10%on the site. However, BMP's have been included for reference in the case where unforeseen circumstances may require them, such as BMP C235: Wattles. ELEMENT 7: Protect Drain Inlets C220: Storm Drain Inlet Protection Onsite inlet protection will use Block & Gravel Curb Inlet Protection. Offsite inlet protection will use Catch Basin Filters manufactured for use at construction sites. ELEMENT 8: Stabilize Channels and Outlets C207: Check Dams Where drainage swales may be created to convey stormwater, temporary gravel check dams may be used to reduce velocity and to dissipate flow energy. ELEMENT 9: Control Pollutants Debris from the demolition of the existing structure (shed) will be placed in a containment bin immediately. No debris shall be stored on site. All fuel, lubricants, paint, and/or other hazardous material shall be stored in a lockable, covered storage container if kept on site. ELEMENT 10: Control De-Watering Test pits were dug to a depth of 7.5 to 8 feet with ground water only appearing at the depths below 7 feet. Therefore, no dewatering is anticipated. ELEMENT 11: Maintain BMPs A trained Certified Erosion and Sedimentation Control Lead (CESCL) will be on the job site. CESCL personnel are trained in and responsible for the proper maintenance of the erosion control BMPs. The CESCL will work with the City of Anacortes Inspector to maintain all BMPs. ELEMENT 12: Manage the Project A trained Certified Erosion and Sedimentation Control Lead (CESCL) will be on the job site. CESCL personnel are trained in and responsible for the proper maintenance of the erosion control BMPs. The CESCL will work with the City of Anacortes Inspector to maintain all BMPs. ELEMENT .3: Protect Low Impact Development BMPs Protect infiltration area from construction traffic and deposition of sedimentation throughout the installation and all construction activities. 8.' ": G' _ C of Anac,_. •'r es invoice/Per/nit #: BUD-2017-0349 904 6th Street Applied date: 07/07/2017 P.O.Box 547 Issue date: 11/20/2017 ';'" Anacortes, WA 98221-0547 1691 Expire date: 05/19/2019 TJ �, ' _ ~ (360) 293-1901 Job Address: 2202 15TH ST Permit Type: Single Family Residence Permit ANACORTES WA 98221 Project: APN: P56250 Remarks: Construct new single family residence per approved plans with ADU Owner: LANDED GENTRY DEVELOPMENT Contractor: LANDED GENTRY DEVELOPMENT INC Address: 504 E FAIRHAVEN AVE Address: 504 E FAIRHAVEN AVE BURLINGTON WA 98233-1846 BURLINGTON WA 98233-1846 Phone: (360) 755-9021 Phone: (360) 755-9021 License #: LANDEGD062D4 General Information: Fees: Occupancy Group it-1 Plan Review Deposit 200.00 Use Zone R2 Building Permit Fee 2,819.35 Lot Area 10475 Plan Review Fee 1,632.58 1st Floor Square Footage 1995 Mechanical Permit Fees 168.35 2nd Floor Square Footage 1435 Plumbing Permit Fee 216.00 Garage Square Footage 855 State Building Code Fee 4.50 Porch Square Footage 169 Sewer Inspection Fee 50.00 Building Valuation 425100 Storm Drain GFC-Residential 1,550.93 # Forced Air Furnace <=1 ,000 1 Sewer GFC-Residential 9,206.33 # of Bathtubs 2 Park Impact Fee 615.00 # of Clothes Dryers 2 Traffic Impact Fee 900.00 # of Clothes Washers 2 Amendments/modifications 55.00 # of Dishwashers 2 Total Calculated: 17,418.04 # of Gas Fireplace 1 Deposits/Receipts: 200.00 # of Gas Piping 1 # of Gas Water Heaters 2 Total Due: 17,218.04 # of Water Piping 2 # of Hose Bibbs 3 -, --i -1' w r-•.• ID -o , ,,' r•- 1.-- 1--- it, 1:11 # of Kitchen Sinks 2 ,-, �, , CO ,rn ;,ti lit it, is:. o.-, co N. # of Lavatories 6 - ,l, cc, , . # of Range Hoods 2 CA �. el- ' ,', if, r.,. Z: , r` ,�, .4.. # of Showers 3 • o _ 5% x:• # of Slop Sinks 2 NO 45. r, # of Ventilation Fans 7 z:• = •o m 1:-;1 1-4 t`'i .. rr, t• ji # of Water Closets 4 �• 1�! � •"^ rn • It, .. t--. --1 r:n I It. ?•a . ni -n r o., c.-' F.,. rnl r•+ I H. 4`..) 1.-- ril I.,:.:. o J It, -%r 1.7I C' Ir, ill r,. ,_••I I-'• r-. ,.-,• -..J .a::,. •m •.,. ,D, C1 P•.) i`.,1 , I--I 4.. I 1-4 ,-',' ri 7. .u .a::,. -P.. it. --J H- ..f Y 4 City of Anacortes Invoice/Permit#: BLD-2017-0349 904 6th Street ',. Applied date: 07/07/2017 P.O.Box 547 Issue date: 11/20/2017 ' Ul Anacortes, WA 98221-0547 ` Expire date: 05/19/2019 .4-11/^jy ffYi� A-rt (360) 293-1901 THIS PERMIT BECOMES NULL AND VOID IF WORK OR CONSTRUCTION AUTHORIZED IS NOT COMMENCED WITHIN 180 DAYS, OR IF CONSTRUCTION OR WORK IS SUSPENDED OR ABANDONED FOR A PERIOD OF 180 DAYS AT ANY TIME AFTER WORK IS COMMENCED. I HEREBY CERTIFY THAT I HAVE READ AND EXAMINED THIS APPLICATION AND KNOW THE SAME TO BE TRUE AND CORRECT.ALL PROVISIONS OF LAWS AND ORDINANCES GOVERNING THIS TYPE OF WORK WILL BE COMPLIED WITH WHETHER SPECIFIED HEREIN OR NOT, THE GRANTING OF A PERMIT DOES NOT PRESUME TO GIVE AUTHORITY TO VIOLATE OR CANCEL THE PROVISIONS OF ANY OTHER STATE OR LOCAL LAW REGULATING CONSTRUCTION OR THE PERFORMANCE OF CONSTRUCTION. 7 • SIGNATURE OF OWNER OR AUTHORIZED AGENTY Fyrrce, Groc From: Fyrrce, Groc Sent: Monday, November 27, 2017 12:50 PM To: 'Art Shaw`; Lange, Steve Cc: Ingalls, Paul; Measamer, Don; Shjarback, Eric; Hohmann,Tim Subject: RE: Permit status 2202 15th Attachments: 07-10-17 Review Memo 2202 15th Street.pdf Hi Art, There was some miscommunication between myself and Public Works. We still need the Civil Drawings from a Washington State-Licensed Engineer showing the improvements required by Public Works along with the value of the work being done so that Engineering Plan Review fees and Construction Inspection fees can be calculated. See attached Plan Review note from Steve Lange for the specifics. Best regards, Groc Fyrrce Building Inspector/Permit Technician City of Anacortes (360)293-1901 eJ�;Peit y e lle ec+r/er7rui,117e4/�/'G(C%4 ee/amyfioil ape/er(y eratioih My incoming and outgoing email messages are subject to public disclosure requirements per RCW 42.56. From:Art Shaw [mailto:art@landedgentry.com] Sent: Monday, November 27, 2017 12:15 PM To: Lange, Steve<stevel@cityofanacortes.org> Cc: Fyrrce,Groc<gfyrrce@cityofanacortes.org>; Ingalls, Paul<pauli@cityofanacortes.org>; Measamer, Don <don@cityofanacortes.org>;Shjarback, Eric<erics@cityofanacortes.org>; Hohmann, Tim <timh@cityofanacortes.org> Subject: Re: Permit status 2202 15th Thanks for checking in, permit has been released and is ready for pick. I will be down this afternoon. Thank you Art Shaw Director of Construction From: stevel@cityofanacortes.orq Sent: November 27, 2017 12:12 PM To: art@landedgentry.com Cc: gfyrrce@cityofanacortes.orq; pauli©a cityofanacortes.org; don@cityofanacortes.org; erics@cityofanacortes.org; timh@cityofanacortes.orq i Subject: RE: Permit status 2202 15th Art, I just got back from a 2.5 week vacation. Thanks for your email. Here is an updated status from the Public Works Engineering Department. Please see below: • The MR#1 to MR#9 was reviewed and accepted by the Public Works Engineering on November 17, 2017. • We are still waiting on the requested information from the July 10, 2017 review by the Public Works Engineering. Thanks, Steven Lange Project manager From: Art Shaw [mailto:art@landedgentry.com] Sent:Wednesday, November 15, 2017 8:59 AM To: Lange, Steve <stevel@cityofanacortes.org> Subject: Permit status 2202 15th Good morning, I was wondering on the status of our permit 2202 15th ave It is on the corner of 15th and D. This homes was submitted in July and has had several drainage recalcs done. My understanding is the building department only reviews site that use 1-5 in the drainage manual and Public works review sites with 1-9. Have you see this permit come across your desk? I was hoping to start this home this week if possible. 2 Cricchio, Kevin From: Jack Reinstra <jackr@landedgentry.com> Sent: Tuesday, October 31, 2017 1:25 PM To: Cricchio, Kevin Subject: RE: 2202 15th Street, BLD-2017-0349 Okay. We will do that. Thank you! From: Cricchio, Kevin [mailto:kevinc@cityofanacortes.org] Sent:Tuesday, October 31, 2017 1:23 PM To:Jack Reinstra <jackr@landedgentry.com> Cc: Fyrrce, Groc<gfyrrce@cityofanacortes.org> Subject: RE: 2202 15th Street, BLD-2017-0349 Okay. Please drop off 3 large sheets&one reduced. Kevin Cricchio, AICP, WPIT I Associate Planner I Planning,Community& Economic Development Dept. City of Anacortes I P.O. Box 547 1904 6th Street I Anacortes, WA 98221 360.293.1937 (work) I kevinc@cityofanacortes.orq I www.cityofanacortes.org My incoming and outgoing email messages are subject to public disclosure requirements per RCW 42.56. From:Jack Reinstra [mailto:iackr@landedgentry.com] Sent: Tuesday, October 31, 2017 1:17 PM To:Cricchio, Kevin <kevinc@cityofanacortes.org> Subject: RE: 2202 15th Street, BLD-2017-0349 Rather than update the plan itself, I will make a separate sheet to go with the plans showing all the deck plan information. From: Cricchio, Kevin [mailto:kevinc@cityofanacortes.org] Sent:Tuesday, October 31, 2017 1:13 PM To:Jack Reinstra<jackr@landedgentry.com> Cc: Ingalls, Paul<pauli@cityofanacortes.org>; Fyrrce,Groc<gfyrrce@cityofanacortes.org> Subject: 2202 15th Street, BLD-2017-0349 Hi Jack. If you're going to go with what the site plan shows (decks) in the rear yard,you'll probably need to update your drawings (floor plans, etc.)to reflect this. The most current shows patios. I'll defer this to Groc or Paul. Thanks. Kevin Cricchio, AICP, WPIT I Associate Planner I Planning, Community & Economic Development Dept. City of Anacortes I P.O. Box 547 1904 6th Street I Anacortes,WA 98221 360.293.1937 (work) I kevinc@cityofanacortes.orq I www.cityofanacortes.org. My incoming and outgoing email messages are subject to public disclosure requirements per RCW 42.56. From:Jack Reinstra [mailto:jackr@landedgentry.com] Sent:Tuesday, October 31, 2017 1:11 PM To: Cricchiu, Kevin<kevinc@citvofanacortes.org> Subject: 2202 15th Street 1 Kevin, We are going to go with what the site plan says and use decks on the back of the house and ADU. So I am now in the process of making a deck plan sheet to go with the plans. We will submit it when it is completed. Jack Reinstra Landed Gentry 2 Ravnik & Associates, Inc CIVIL ENGINEERING & LAND-USE PLANNI 0w N-4 TEC Z �, • STORM DRAINAGE MEMO OCT 7 20 ��. bill for 2202 15TH Street • CITY OF ANACORTES (BLD-2017 0349) • • vie, LANDED GENTRY HOMES RESIDENTIAL DEVELOPME Revised: October 26, 2017 September 29, 2017 The residential development proposed herein located at 2202 15th Street in Anacortes, Washington is generally proposed to include construction of a new house and driveway 74.p-r which will create an increase in the stormwater runoff from the site. The new roof_ar (3,376 sf), driveway (1,190 sf), and new sidewalk (470 sf) for a total of ,036 of new impervious surfaces on a 10,475 square foot lot where an existing building, gravel and r - 1 lawn areas currently exist. Stormwater runoff from the proposed 3,376 sf house roof area will be collected by downspouts and conveyed via a tight-lined system to a proposed infiltration trench to be installed within the northerly area of the lot. The driveway will be cross-sloped downhill to the west to promote dispersion and infiltration of runoff waters onto adjoining lawn areas which area large enough to infiltrate up to the 100aye Urt t-L— storm as noted further on within this report. The sidewalk vit "dollect runoff via a new gutter and convey it east, then north along the west side of `D" Avenue where it will enter an existing catch basin, as generally occurs today. /`Additional small areas of N Now INGd., impervious surfaces, such as walkways, etc will be graded to disperse runoff via sheet I u flow onto adjoining areas of lawn/landscaping. Initially the DOE Flow Chart 1-2.4.1 Flow Chart for Determining Requirements for New Development has been used to determine that all minimum requirements apply to the new and replaced hard surfaces and converted vegetation areas. Most notably are Minimum Requirements #5-Onsite Stormwater Control, #6-Runoff Treatment, & #7-Flow Control. This project proposes to infiltrate runoff generated from a majority of the new and replaced hard surfaces as noted within the following sections of this report. Since the design within this report notes impervious surfaces (with the exception of the sidewalk) will be infiltrated as confirmed by use of a continuous model software(WWHM) they are considered "ineffective impervious surfaces", and thereby is Flow Control exempt per DOE Volume I Section I-2.5.7. T'Ro��: t s � �,,� G.o,.rrlz.o tr lnF,.47 6T Q 1Rort,-r D►SL44,42-G*s 1.) 5A0r- Id ' A VLo i✓ coo lt 'R- As required by the 2014 Department of Ecology Stormwater Manual, the Western Washington Hydrology Model (WWI{M), a continuous model software,has been used to calculate pre-developed runoff conditions, post-developed runoff conditions, and the combined performance of storage volume and infiltration discharge. As further described herein, a underground detention/infiltration facility will be used to infiltrate the runoff from the new house. When sizing infiltration trenches using WWHM software, a theoretical riser outlet structure is purposely included within the analysis. If water is P;IProjects1170201DOCS1Drainage Memo 10.26.17.doc 1 1 €33 LINDAMOOD LANE / P.O. BOX 36 1 BURLINGTON, WA 98233 PH:(360) 707-2048 , FAX:(360) 707-2216 found to be released through the riser structure,the volume of rainfall upon the developed site will be considered to have exceeded the system's infiltration and detention capacities, thereby identifying a failure in design. A properly designed and most efficient drainage system will use the infiltration and detention facilities to their maximum capacities _without noting any water released through the theoretical riser used in the model. W WHM also be used to estimate 100-year runoff rates generated from the new driveway area in order to determine how much area will be needed to infiltrate 100% of these 13 CP waters. 3 Using WWHM three models were created to demonstrate the performance of the (1) � Infiltration trench to infiltrate roof runoff, (2) Determine the necessary area required to infiltrate runoff from the proposed driveway area, and (3) Determine the runoff rates generated from the 470 sf of new sidewalk proposed along the project frontage. i ,ve-p 1rJ �1i.Y'¢bf�.� W,.si 15 1,� W/He_ P House Basin: /��'ctGe c srcmarva,. lap.L-��-�,oN �vaa,. dr©r� �1'tu,a, `n b Using an infiltration rate of 6.33 inches per hour as allowed within the attached ° geotechnical report prepared by Geotest for this project, it has been determined that it ,tv will take 461f of 2-foot wide x 2-feet deep infiltration trench having a bottom elevation set at 3-feet below surface is necessary to infiltrate 100% of the post-developed runoff © d waters generated from the new 3,376 sf(0.77-ac) house roof area. As noted within the WWHM view information provided with this memo for the House it is noted that 0 cfs is N released via the riser used in the modeling, indicating 100%infiltration has been achieved using the proposed trench. Refer to WWMH view and Report for the House attached with this memo for more detailed analysis information. 7 Cu..2..sc- ALTiLRNA.:V.L z.$ 7 t DS‘4N c_)'T'A.46. o.rr-t�vyL 0 t N St+`?'S,1 O L1 f b 5 -tn..� tql Proposed Infiltration Trench(tight-lined to downspouts): -_ k 46'long x 2' deep x 2' deep Drainrock filled trench(bottom @ 3-feet below ex. grade) o :f Void Ratio: 0.33 Z 1 Infiltration: 6.33 in/hr(per the geotechnical report prepared by Geotest dated 08/30/17) 144 V Since the approved runoff model methods note that the entire runoff file is infiltrated up though the 100-year storm, the house is considered to be "ineffective" per (per the definition of"Effective Impervious Surface"(DOE Manual Volume I-Appendix G). The attached Memo prepared by Geotest Engineers notes that the proposed infiltration trench is extremely unlikely to negatively impact any surrounding foundations at its proposed location 11-feet from the north property line. Driveway Basin: (AS iD/Bu.F—w t crrl few 2-a' F- As an alternative way to look at the driveway dispersion/infiltration provided, the use of p arT c.12 WWHM allows us to calculate the 100-year flow frequency runoff that will be generatedo¢ T��L from the 1,190 sf(0.028 acre) of driveway area to be dispersed. Based on this analysis the 100-year storm event runoff values increase from 0.0016 cfs during the predeveloped dF 2 ) (forest) condition up to 0.0171 cfs for the post developed (concrete) condition. This G D Fo 2 0.0155 cfs increase in runoff that is anticipated from the conversion of 0.028 acres from 3Z' pm, t forested condition to concrete driveway can easily be infiltrated onto the undeveloped W I UT-( P:1ProjectsV170201DOCS.Drainage Memo 10.26.17.doc 2 -L\©DtA..1.7 Ou 5 c St©FLwr�� 5�'t,f4i �w4YS landscape area located to the west of the proposed driveway. Using a 1.50 in/hr infiltration rate from the attached geotechnical report prepared by Geotest, it only will take approximately 493 sf of area to infiltrate the 100-year storm even in an area where there is over 1,200 sf of area available. Refer to the following equations: Infiltration Rate Use 1.50 inch/hour = 0.0250 inch/min = 0.0000347 fps Required Infiltration Area for 0.028 ac driveway for 100-year storm 0.0171 cfs/0.0000347 fps = 493 square feet of area required to infiltrate the runoff from the developed 100-year storm event for the entire driveway area. Since the length of driveway is approximately 40 feet, it is estimated that it will take approximately 12.31 feet of width of vegetation and/or undisturbed soil along the west side of the driveway to infiltrate runoff from the 100-year storm. Based on the driveway length of 40 feet, full infiltration will be achieved in 12.31 feet. As with the roof runoff, since WWHM analysis (an approved continuous runoff modeling method) indicates that entire runoff file is infiltrated up though the 100-year storm, the house is considered to be "ineffective" per (per the definition of "Effective Impervious Surface". Sidewalk Basin: To estimate the 100-year flow frequency runoff that will be generated from the 470 sf (0.011 acre) of new sidewalk area WWHM will be used. Based on this analysis the 100- year storm event runoff values increase from 0.0006 cfs during the predeveloped (forest) condition up to 0.0067 cfs for the post developed (concrete) condition. Therefore there is only a 0.0061 cfs increase in runoff anticipated from the conversion of 0.011 acres from forested condition to concrete sidewalk. This area is considered Non-Pollution Generating Impervious surface (NPGIS). This surface is classified as "effective impervious surface" per the DOE manual. This new sidewalk area will be sloped to direct flows to the adjoining gutter which will convey waters easterly, then northerly to the existing catch basin structure located near the subject properties northeast corner. This small increase in "effective impervious surface" generated with this project will not have a significant impact on the existing drainage system and is noted as t from Runoff Control as noted within the summery section of this report. \- ' >l- -k le$24uvz 8 rOg &N DO Summary i L r�E►rr A.04 cao4J ccurr�� For the proposed roof area, based on the areas previously noted, tight-lining roof downspouts to a 46-foot long x 2-foot-wide x 2-feet-deep drainrock filled infiltration trench and dispersing driveway runoff onto areas with vegetated flow path length greater than 12.31-feet is sufficient to mitigate the increase in stormwater runoff that will be P:IProjects1170201DOCS.Drainage Memo 10.26.17.doc 3 created by the construction of this new house. Both of these new impervious surfaces are considered ineffective per DOE definition of"Effective Impervious Surface" within the DOE Manual(Volume 1-Appendix G). The new sidewalk along the existing roadway comprised of 470 sf of new concrete will be the only"effective" impervious surface proposed with this project. As previously determined using the WWHM analysis, the new roof area will be infiltrated and the new driveway area that will be dispersed and infiltrated makes these two impervious surfaces classified as "ineffective"per the DOE manual, leaving only the new roadside sidewalk. Accounting for the new roof area, driveway, and new roadside sidewalk, only increases the 100-year flow frequency runoff flows from 0.0065 cfs (0.0043 cfs + 0.0016 cfs + 0.0006 cfs) for the pre-developed to 0.0709 cfs0471 c s + r 0.0171 cfs + 0.0067 cfs) during the post-developed condition. This shows there 's only a 3t 0.0644 cfs net increase in runoff during the 100-year flow frequency as estimated C using the WWHM model, which is less than 0.10 cfs threshold, making this project `r exempt from DOE Requirement #7-Flow Control as noted in the following paragraph even when conservatively accounting for the ineffective impervious surfaces. Per DOE section 2.5.7-Minimum requirement #7-Flow Control a project is eX -from providing flow control is the project if: 0 1)The project has less than 10,000 square feet of effective impervious surfaces, 2) The project converts less than % acre of vegetation to lawn for landscape (or converts less than 2.5 acres of native vegetation to pasture), f. and 3) Through a combination of effective hard surface and converted vegetation areas cause less than a 0.10 cubic feet per second increase in the 100-year flow frequency as estimated using the WWHM model. - The analysis determining the difference in flow was conservatively performed using the forested land cover for the predeveloped condition as per the footnote in DOE Manual Volume I-Chapter 2 (page 65) states that the 010 cfs increase should be a comparison of the post project runoff to the existing conditions runoff based on the pre-project land cover, or the land cover that existing at the site as of a date when the local jurisdiction U` first adopted flow control requirements into code. Since this project has shown that proposed roof area is infiltrated and the driveway area has sufficient area to the west to infiltrate driveway runoff, based on the WWHM flow �1 frequency values, means that these areas are technically not an "effective impervious area" (per the definition of "Effective Impervious Surface" (DOE Manual Volume I- Appendix G). Therefore this results in the project only having 470 sf of "effective impervious surface" which is less than a total of 10,000 square foot threshold of the "effective impervious surfaces". In addition the runoff increases less than 0.10 cfs during the 100-year flow frequency based on the WWI-IM model, therefore this project is exempt from providing Runoff Control as noted. Furthermore, since this is determined to P:IProjects1170201DOCSIDrainage Memo 10.26.17.doc 4 1 be Flow Control exempt in accordance with DOE Manual section 2.5.7 as noted above, this project is not required to meet LID performance or standards as noted in section -•. 2.5.5-Minimum Requirement #5-On-site Stormwater Management other than what is .2, noted below. v\ i DOE MINIMUM REQUIREMENTS Based on the thresholds noted within the 2014 Department of Ecology Manual's Flow Chart for Determining Requirements (Figure 2.2) attached, the proposed single-family residential development requires the project to meet Minimum Requirements #1-9, r however since the engineering analysis using an approved continuous model software shows that use of the infiltration trench will infiltrate the roof runoff, and it has calculated that there is sufficient area to the west of the new driveway to disperse and infiltrate runoff onto adjoining vegetated areas to remain, this project is not required to provide runoff controls, and subsequently only minimal Onsite Stormwater Management requirements as noted below. The following are the DOE Minimum Requirements #1-9 and how they are addressed: Minimum Requirement#1-Preparation of a Stormwater Site Plan The owner will provide a stormwater site plan which addresses development principles noted within this report. Minimum Requirement#2-Construction Stormwater Pollution Prevention (SWPP) Prior to commencing any construction the project's contractor must prepare a Construction Stormwater Pollution Prevention Control Plan that identifies the measures they will address each of the 13 Construction SWPPP Elements as necessary to prevent the erosion and discharge of sediment and other pollutants from the site. Minimum Requirement#3-Source Control of Pollution No source control BMP's are anticipated with this residential project. Minimum Requirement#4-Preservation of Natural Drainage Systems and Outfalls This project proposes to infiltrate runoff waters other than the small amount of runoff from the new sidewalk which will be conveyed to the existing drainage systems that currently receive runoff from the area. Minimum Requirement#5-On-Site Stormwater Management This item requires the employment of On-site stormwater management B uI"s to- , encourage_infiltration and dispersion of developed stormwater runoff. s project is not 1 required to provide Runoff Control as denoted within this report,therefore it is also not 1 required to provide LID Performance requirements, or follow List#1 or#2, however the project is required to im lement BMP T5.13;BMP's T5.10 A,B,or C; and BMP's TS.11 T5.12 as feasible. Infiltration has also been mcorporated into the design or e both the roof an i ay runoff. I C ►^17.0 '.6`lit6 Pr--0J4.-4-T %4 f &) c.00TL ?-A10 AG,e- •PANG.c .)1TH t-2.S,7 a 1.o66 NoT ''''`AV -1-a 4UN,tom-`C7clt- lap S volz ,,,-$C.E 5rA0CA2D r 1402 G..B,a g 1 Dr-Q-- 133%6 +w?. P:lProjects1170201DOCSIDrainage Memo 10.26.17.doe 5 2A.t►.! 4lig.091.,•>s P -¢-.AtSL_Ce. Pasg 4„..71-4 t K'u.LV Disr -s1/4. ?. T Dc E S 4-eAuk Tc 6.0 r.a S t D SA_ T- ]C OT-ftE.k c5p-r,a+.) S O,0 2-4 5 r IT 'a t N m Qa t e_ l,,.,c.L...D+A+t, 13r1PTS, 13) f' T5.4o 4.,t13oa6. Au.% ISM P"VS,lk X14-b seq- 1'5,12 , err ig,,c-. Opts 5 Pos.-r4T-A`` 601191 ... P&PS ks N5 is Minimum Requirement#6-Runoff Treatment 4. 3/q. Ac-v-v • - Runoff treatment is required for all Pollution Generating Pervious and Impervious surfaces (PGPS and PGIS). The only pollution generating surface proposed it the driveway areas for this project, as roof runoff is considered non-pollution generating. The proposed driveway surface is to be constructed with a cross slope to direct runoff waters to disperse onto adjoining vegetated areas where there is sufficient width of vegetation rovid e 915`per the-sto„n iunof"sufficient contact time to provide- water quali before being discharged fxttm_thesite: P r\? i S. 12 P tom..?"2---s #7-Flow Control ~ram � ,4s:-o ay rt FT A -r'►t�s As previously noted per DOE section 2.5.7-Minimum requirement #7-Flow Control, a I►r,a sa-- project is exempt from providing flow control if the project is: 1411'' �'"i 1) The project has less than 10,000 square feet of effective impervious surfaces, 2) The project converts less than % acre of vegetation to lawn for landscape (or converts less than 2.5 acres of native vegetation to pasture), p and Zi. 3) Through a combination of effective hard surface and converted vegetation _ areas cause less than a 0.10 cubic feet per second increase in the 100-year flow frequency as estimated using the WWHM model. Since this project has shown that both the roof and driveway have sufficient area infiltrate, based on the WWHM software analysis which makes these areas classified as i, "ineffective impervious area" (per the definition of"Effective Impervious Surface"(DOE Manual Volume I-Appendix G). Therefore this results in the project having less than a total of 10,000 square feet of "effective impervious surfaces". In addition the runoff rincreases less than 0.10 cfs during the 100-year flow frequency based on the WWHM model therefore this project is exempt from providing runoff control as noted. s � z #8-Wetlands Protection There is no discharge proposed from this site to any wetland. � 3 #9—Operations and Maintenance ~ Not applicable to this project. o Pt T•o.. A up tArreu 4,4&E F‘cTtui-T� ¢4,c..44 W I c..c. 'E. Y.K . ah-..sPo S S t L f k s F T-i-t. 5 i.o► 0...0 Et A 09 S}tA.0 F?f F IN Ae-e..-sQfle, t_e_ t)/1`te ?—Q . o� IA? 1 S. n A k C-0- eak ►1-r4 Z.OI bow r AN“4,_ P:IProjects1170201DOCS1Drainage Memo 10.26.17.doe 6 APPROXIMATE LOCATIOIN OF 46' LONG x 2' WIDE X 2' DEEP DRIANROCK Fn... !WENCH ►p.LivG7/ iui' 1twar uiiA/Nb; PER 1NFILTRA710N TRENCH DETAIL 1 13 sr.s cavc SS fL 1 4 SS SS SS SS SS�o.ays0 SS SS SS, — ss QSAi140. f0n0" 1I' Ur; Oe N — I v46.00' LI 10.00' Iin 7000' jQYuai II101 I I I ROOF LINE 1 1 = 1 1 H I PROPOSED D tz)I I D ROOF AREA = I 3,376 SF) is _ 1 > 0j!i UJ 4r — Q —° ° ..32. 'O' ° — 10.67' 18.00' ; a SLOPE 1%MIN • 20.00' °. d° a ° S 6144) 1 i u a ° rs T'�/ - - - - - -.- — - - - - - - °.SLOPE'IX ivy 104.92' e °' pA . il I 20.`00° / fJ / -l--PROPiSED NEW SIDEWALK 470I SF) -' - i9 1 15TH STREET M & -- - - - - - —. - w = - - „ - M M M M Y N M I \ \ \) —IF e' . 1 I I y iNI —' M—1_ SHEET DESORPTION:& Associates, Inc. N.T.S. CIVIL ENGINEERING & LAND-USE PLANNING STORMWATER DRAWN BY: HLH 1633 LINDAMOOD LANS/PR SOX XI PE: , F, , •2216 EXHIBIT JOB NO. 17020 DATE; 09.28.17 STORM WATER EXHIBIT FIGURE I-2.4.1-FLOW CHART FOR DETEMINING RQMNTS FOR NEW DEVELOPMENT DOE DEFINITION OF EFFECTIVE IMPERVIOUS SURFACE INFILTRATION TRENCH DETAIL P:IProjects1170201DOCSIDrainage Memo I0.26.17.doc 8 Figure 1-2.4.1 Flow Chart for Determining Requirements for New Development Start Here Does the site have 35% Yes See Redevelopment Minimum or more of existing Requirements and Flow Chart impervious coverage? (Figure 1-2.4.2). No Does the project convert 3/4 acres or more of vegetation to Does the project result in lawn or landscaped areas, or 5,000 square feet, or f` convert 2.5 acres or more of greater, of new plus native vegetation to pasture? replaced hard surface area? No Yes Yes Does the project result in 2,000 ® r square feet, or greater, of new plus ll Mhaiuu-ium Requirementsreplaced hard surface area? apply to the new and replaced hard surfaces and converted vegetation areas. jJ``g No Does the project have land R,fJinimum Requirements#1 disturbing activities of 7,000 through #5 apply to the new l n , square feet or greater? and replaced hard surfaces and the land disturbed. No Minimum Requirement#2 applies. Figure 1-2.4. 1 Flow Chart for Determining Requirements for New Development DEPARTMENT OF Revised June 2015 ECOLOGY Please see http://www.ecy.wa.gov/copyright.hfml for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume I - Chapter 2 - Page 37 Drop structure A structure for dropping water to a lower level and dissipating its surplus energy; a fall. A drop may be vertical or inclined. Dry weather flow The combination of ground water seepage and allowed non-stormwater flows found in storm sewers during dry weather.Also that flow in streams during the dry season. - E - EIS See Environmental Impact Statement. ESC Erosion and Sediment Control (Plan). Earth material Any rock, natural soil or fill and/or any combination thereof. Earth material shall not be considered topsoil used for landscape purposes.Topsoil used for landscaped purposes shall comply with ASTM D5268 specifications. Engineered soil/landscape systems are also defined independently. Easement The legal right to use a parcel of land for a particular purpose. It does not include fee ownership, but may restrict the owners use of the land. Effective Impervious Surface Those impervious surfaces that are connected via sheet flow or discrete con- veyance to a drainage system. impervious surfaces are considered ineffective it 1) the runoff is dispersed through at least one hundred feet of native vegetation in accordance with BMP T5.30: Full Dispersion (p.939); 2) residential roof runoff is infilt- rated in accordance with BMP T5.10A: Downspout Full Infiltration (p.905); or 3) approved continuous runoff modeling methods indicate that the entire runoff file is infiltrated. Embankment A structure of earth, gravel, or similar material raised to form a pond bank or found- ation fora road. Emergent plants Aquatic plants that are rooted in the sediment but whose leaves are at or above the water surface.These wetland plants often have high habitat value for wildlife and waterfowl, and can aid in pollutant uptake. 2014 Stormwater Management Manual for Western Washington Volume I-Appendix G-Page 157 4"DIA.RIGID PERFORATED PIPE FILTER FABRIC 2' 1 i 1' ..........____ FINISHED GRADE 11:111 '1=•:,.:-:•::.":;.T.c.;;;:',...,;:t.......•,:..::::,•11. :.::.:!:;:,ati- L.M . TOP 11EA ii. ..,WASHED ROCK 1 TRENCH DEPTH zif, 1111 I BOTTOM 1 1/2"TO 3/4" INFILTRATION TRENCH SECTION A-A WASHED DRAINROCK Ravnik & Associates, Inc. SHEET KICRIF1101t MALL KM CIVIL ENGINEERING&LAND•USE PLANNING INFILTRATION -- "ISK LIIDAMOOD Ittri.P.11 KIX 3E1 NT'"M."PAX"W-4-7-414216 TRENCH EXHIBIT DAM MUM SOILS INFORMATION STORMWATER INFILTRATION EVALUATION MEMO P:1Projects1170201DOCSDrainage Memo 10.26.17.doc 7 • 741 Mame Drive [/�'■A_[A) [I�+�r�♦l Bellingham,WA 98225 380 733_7318 20811-676 Avenue V�►" V VT1a,F .IT Arlington,WA 89223 8882515278 380733_7418 August 30,2017 Job No. 17-0425 Landed Gentry Homes and Communities 504 East Fairhaven Avenue Burlington,WA 98233 Attn.: Steven Baughn Re: Stormwater Infiltration Evaluation Padilla Adu Development 2202 15th Street Anacortes,Washington Dear Mr. Baugn, As requested, GeoTest Services, Inc. (GTS) is pleased to submit this report summarizing the results of our stormwater infiltration evaluation associated with the proposed single family residence at the subject property in Anacortes, Washington, as shown on the Vicinity Map(Figure 1). The purpose of this evaluation was to assess the existing subsurface conditions for use in designing stormwater infiltration system(s) associated with proposed development. This report summarizes our conclusions and recommendations regarding the potential for onsite stormwater infiltration. Specifically, our services included the following: 1. Evaluation of 3 test pits equally distributed across the subject property. Test pits explorations were advanced to7.5 feet below the ground surface(BGS). 2. Geological review of the information collected during this phase of the investigation in order to provide recommendations for the project. Our findings and recommendations are summarized in this site-specific report and contain the following information: • A site plan showing pertinent existing site features and the approximate location of the explorations accomplished for this project. 6 Logs of our explorations and results of our laboratory testing including a chart illustrating the soil classification criteria and the terminology and symbols used on the exploration logs. • Laboratory determinations of soil classification, including the long- term infiltration rates of soil encountered. infiltration rates are based on USDA soil gradation analysis, in general accordance with the 2012 Stormwater Management Manual for Western Washington (SMMWVV) amended December 2014. Laboratory evaluation on collected soils included USDA sieve analyses and moisture contents. Page 1 of 7 GeoTest Services, Inc. August 30, 2017 2202 15`h Street,Anacortes,WA Job No. 17-0425 A summary of surface and subsurface soil and groundwater conditions observed at the site during our field exploration. The summary includes descriptions of subsurface profiles and the potential seasonal effects of groundwater. The scope of services for this report included stormwater infiltration only, it does not include geotechnical recommendations with regards to the planned building foundation support, settlement, potential seismic considerations such as liquefaction and/or other geologic hazards that may exist within this property. PROJECT DESCRIPTION We understand that there are plans to develop the subject property with a single-family residence with associated stormwater facilities and utilities. As part of the development, the stormwater facilities will be constructed to accommodate onsite stormwater runoff from proposed impervious surfaces. The attached site and exploration map should be considered preliminary. SITE CONDITIONS This section discusses the general surface and subsurface conditions observed at the project site at the time of our field investigation. Interpretations of the site conditions are based on the results of our review of available information, site reconnaissance, subsurface explorations, laboratory testing, and our experience in the project vicinity. Surface Conditions At the time of our visit, the subject property was bordered by single family residences along its western and northern extent and D Avenue and 15th Street to its east and south, respectively. The property contained a 2 bay out building near its southwest corner and was covered in a grass lawn. In general, the property sloped slightly downwards towards the north, with elevation changes being less than about 5 vertical feet. Site Geology Geologic information for the project site was obtained tram the 'Washington Interactive Geologic Map," published by the Washington State Department of Natural Resouces (DNR). According to this map, deposits at the project consist of Fraser-Age continental glacial till (Qgt). The till is a non-sorted and unstratified mixture of clay, sand pebbles, cobbles, and boulders (diamicton), deposited by glacial ice. The soils encountered in our subsurface explorations are generally consistent with the published geological information and our experience with projects in the nearby vicinity. Page 2 of 7 GeoTest Services,Inc. August 30,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 Subsurface Soil Conditions Subsurface conditions were explored by excavating 3 test pits (TP-1 through TP-3) on June 27, 2017, Approximate locations of these explorations have been plotted on the Site and Exploration Plan, Figure 2. The test pits were advanced with a tracked excavator to depths of 7.5 feet BGS. After test pit explorations were completed, the pits were backfilled with the excavated soils and compacted with the bucket of the excavator. In general, subsurface soils encountered within the area of proposed development consisted of approximately 0.5 to 1 foot of topsoil (soft, brown, moist, organic silt) that overlays 2 to 4 feet of weathered glacial till loose to medium dense, brown, moist, silty sand to slightly silty sand) with very stiff to hard, sandy silt with pebbles and cobbles (glacial till) extending to full depth within all 3 test pit locations. some minor fill soils were located above the weathered till in TP-2 and TP-3_ Please refer to the attached exploration logs for more detail (Figures 4 through 5). Groundwater Seepage and Seasonal Groundwater For the purposes of this report, observed groundwater seepage represents either the existing surface of a groundwater table or the surface of perched seepage. The groundwater table is referred to as the atmospheric pressure surface that coincides with the top of the zone of saturation and is the surface that dictates the development design recommendations in this report. Perched seepage is referred to as a saturated zone that develops where a restrictive surface (i.e. dense, fine grained soils or bedrock) limits the vertical, downward migration of near-surface water. The groundwater table or perched seepage surface should be considered when determining methods of earthwork construction but is not used to dictate development design, Groundwater Observations At the time of our visit on June 27, 2017, minor, perched groundwater seepage was observed within the test pits between 4.5 and 6.0 feet BGS. As the region has not, at the time of our site visit, recently experienced precipitation, we interpret the groundwater to be interflow running along the very dense till soils with elevated fines content, generally encountered onsite at approximately 4.5 to 6.0 feet BGS. During periods of extended and/or heavy rainfall we would anticipate that groundwater would be found perched on the very dense till soils with elevated fines content. Seasonal Groundwater Fluctuation Observations A distinct mottled horizon or °rust line," was not encountered within the test pit explorations. Mottling (reddish-brown, orange, or yellow splotches or mottles) is typically indicative of soils that experience fluctuating moisture conditions, generally due to seasonal wetting and drying. Gleyed soils, indicative of poorly drained and potentially restrictive soils, were encountered within the unweathered, very stiff to hard till. Gleyed soils are typically gray or bluish-gray in color and the result of a reduced (non-oxidative) soil state caused by Page 3 of 7 GeoTest Services,inc. August 30, 2017 2202 15th Street,Anacortes,WA Job No. 17-0425 significant periods of saturation. Gleyed soils are often associated with soils that are restrictive of groundwater flow. Please note that changes to soil color and morphology may take significant periods of time to develop and may not be reliable indicators of groundwater conditions in areas that have experienced significant recent changes in hydrology. Additionally, in areas of fill, sufficient time may riot have passed since fill placement for these indicators to develop. Not all hydric soils exhibit mottled and/or gleyed horizons. Their presence or absence alone should not dictate the interpretation of site groundwater conditions. Sources of groundwater table fluctuations As groundwater table levels and/or seepage rates are typically not static, it is anticipated that groundwater conditions will vary depending on local subsurface conditions, season, precipitation, changes in land use both on and off site and other factors. Markedly, we anticipate that groundwater conditions on site are largely influenced by seasonal variations of precipitation. Considerations GTS considers the depth at which groundwater seepage stabilizes and ponds to be the groundwater table. Groundwater seepage will influence stormwater management facilities and should be considered when designing those facilities. The groundwater conditions reported on the test pit logs are for the specific locations and dates indicated, and therefore may not necessarily be indicative of other locations and/or times. Please consider that groundwater table levels are generally higher (at shallower depths) during the wetter months(October through May). Our construction recommendations consider the groundwater conditions encountered at the time of our field investigation, in association with the project design provided at the time of this report. It is the clients and their (his/her) representative's responsibility to inform GTS of variations in groundwater conditions and/or any modifications to project designs so that a review of and revision to report recommendations can be made, if necessary. Unless specifically requested, GTS is not responsible to provide monitoring of groundwater conditions beyond the time of our site investigations. Please keep in mind that groundwater conditions may be different if there is a substantial lapse of time between submission of this report and the start of construction. If this is the situation, GTS recommends we be contacted to evaluate groundwater conditions in order to determine whether our report conclusions and recommendations remain applicable. RESULTS Stormwater Infiltration Potential Test Pit Gradation Results From the explorations excavated in the areas of interest, 13 representative soil samples were selected and mechanically tested for grain size distribution and calculation according to the 2012 Stormwater Management Manual for Western Washington Page 4 of 7 GeoTest Services,Inc. August 30,2017 2202 15"'Street,Anacortes,WA Job No.17-0425 (SMMWW) amended December 2014, soil grain size analysis method, Section 3.3.6. A summary of these results are reproduced in Table 1 below. 1.1 ' Test PR Sample DesignGeologic Hui Uncorrected Rate Dealgn Infiltration Rabe ID Depth USCs Unit (InchrmlHour) Per AVM D422 Simplified (ft) Approach(Inches/Hour) TP-1 1.0 SM Weathered Till 9.30 1.51 TP-1 2.0 SP-SM Weathered Till 38.09 6.17 TP-1 4.5 SP-SM Weathered Till 48.08 7.79 TP-2 2.5 ® Weathered Till 9.26 1.50 TP-2 5.0 ML Glacial Till 2.24 0.36 TP-3 2.0 SM Weathered Till 11.71 1.90 TP-3 3.5 SP-SM Weathered Till 39.08 6.33 Notes: -Ksat=Initial Saturated Hydraulic Conductivity -Listed Infiltration rates are estimated long-term(design)rates based on the soil grain size analysis method. -Correction Factors Used:CFv=0.70 In the simplified approach (Section 3.3.4) the infiltration rate is derived by applying appropriate correction factors to the measured saturated hydraulic conductivity (Ksat) from the ASTM 422 grain size analysis. Saturated hydraulic conductivity is a quantitative measure of a saturated soil's ability to transmit water when subjected to a hydraulic gradient. It can be thought of as the ease with which pores of a saturated soil permit water movement. Saturated Hydraulic Conductivity is expressed as follows: Log10(Ksat)=-1.57+ 1.90D10+0.015Doo-0.013D90-2.08fn„. Where D10, Dsa, and DOo are the grain sizes in mm for which 10 percent, 60 percent, and 90 percent is more fine and km,is the fraction of the soil(by weight)that passes the U.S. No. 200 sieve. is measured in cm/sec. With this equation, we can determine the saturated hydraulic conductivity for our representative samples. See example below: Test Pit TP-1 at 1,0 foot BGS: Kot = 0.006562964 cm/sec or approximately 9.30 inches/hour. Applying correction factors for site variability (0.45), test method (0.4) and degree of influent control to prevent siltation and bio-buildup (0.9) gives a corrected long term design rate of 1.51 inches/hour for the example above. Based on the 2012 SMMWW(amended December 2014)soil grain size analysis method and our applied correction factors, the weathered glacial till soils located below the topsoil contains estimated long term design infiltration rates ranging between 7.79 and 1.50 in/hr Accordingly, we recommend using the lowest result value of 1.50 inmr for use in design for the weathered glacial till. Page 5 of 7 GeoTest Services,inc. August 30,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 Stormwater Pollutant Treatment The stormwater facilities on-site may require some form of pollutant pre-treatment or treatment with an amended soil prior to onsite infiltration or offsite discharge. It is our opinion, based on past experience, that the re-use of onsite topsoil and weathered Outwash Soils is often the most sustainable and cost effective method for pollutant treatment purposes. Cation exchange capacities, organic contents, and pH of site subsurface soils were determined to establish their pollutant treatment suitability. Cation Exchange Capacity, Organic Content and pH Testing Three composite samples were collected during our subsurface explorations for pollutant treatment purposes. Cation exchange capacity (CEC), organic content (LOI), and pH tests were performed by Northwest Agricultural Consultants. Laboratory test results are presented in Table 2. Test Pit Sample Cation Exchange Capacity Organic Content pH ID Depth(ft) (meglloo grams) (%) TP-1 1.5 11.8 6.34 5.6 TP-2 5.0 21.5 7,78 5.5 TP-3 3.5 6.1 3.65 6.8 Criteria SSC-6 states that cation exchange capacity must be greater than or equal to 5.0 meq/100 grams and organic content must be a minimum of 1.0 percent for treatment purposes. Based on the results listed in Table 2, the Topsoil and weathered glacial till appear to be suitable for onsite pollutant treatment purposes based on the SSC-6 of the 2012 Washington State Department of Ecology Stormwater Management Manual for Western Washington. Additional considerations to using infiltration as a treatment option include the soil infiltration rate/ drawdown time as described in SSC-4 of the 2012 Washington State Department of Ecology Stormwater Management Manual for Western Washington. A maximum drawdown time is applied to some types of infiltration based water quality design facilities. LIMITATIONS The scope of services for this report included stormwater infiltration only, this report is not intended to address other geotechnical concerns with regards to the planned building foundation support, settlement, potential seismic considerations such as liquefaction and/or other geologic hazards that may exist within this property. GeoTest can perform additional geotechnical evaluation and/or analysis, with regards to the above mentioned geotechnical items, upon request. The analyses, conclusions, and recommendations provided in this report are based on conditions encountered at the time of the subsurface exploration performed by GeoTest Services, Inc., information from previous studies and our experience and judgment. Our work has been performed in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing under similar Page 6 of 7 GeoTest Services,Inc. August 30,2017 2202 15thStreet,Anacortes,WA Job No. 17-0425 conditions in this area. GeoTest Services has prepared this report for the exclusive use of Landed Gentry Homes and Communities and their design representatives for specific application to the proposed new development located 2202 15't' Street in Anacortes, Washington. No warranty, expressed or implied, is made. We must presume the subsurface conditions encountered are representative for the proposed site for the purposes of formulating our recommendations. However, you should be aware that subsurface conditions may vary with time and between exploratory locations, and unanticipated conditions may be encountered. If construction reveals differing conditions or the design is modified, we should be retained to reevaluate our recommendations and provide written confirmation or modification, as needed. We appreciate the opportunity to be of service to you on this project. If any questions should arise regarding this report, please contact the undersigned. Respectfully Submitted, GeoTest Services, Inc. tr r I r ei,�,Iitten*r Gtahvv . i '- sed Geo, l- Tim Chylla Tim Chylla, L.E.G. Engineering Geologist Attachments Figure 1 Vicinity Map Figure 2 Site and Exploration Plan Figure 3 Soil Classification System and Key Figures 4-5 Logs of Test Pits Figures 6-7 Grain Size Distribution Northwest Agricultural Results(1 page) ASFE-Report Limitations and Guidelines For Its Use(3 pages) References Interactive Geologic Map of Washington State. Online interactive services provided by the Washington State Department of Natural Resources. Washington State Department of Ecology, 2012 (amended December 2014). Stormweter Management Manual for Western Washington. Page 7 of 7 1...-. __ PROJECT LOCATION 1 . 1 I , - , 4 10/:‘,1 ' 4 . • , . i'• :,1 -4 Celt)•',Ft'..1 i'. 1-1•E's ,,it, -J1 4? . t N.1 14,—-3t •' .. g t % t r ? > ! "i• Volunteer Park rth ../A6 4.:• 4" •tr ' ., t..1 IX TIn t ...) •},OS i 7,.,, c ;F),,J C,).Arlacarles,Morina .. 1 . • .• Cranberry' _ i• .. 4; 0 Anaf-ortei-.; Lake Park iii Vitt 6. ' r-c Airport P 0 > , re L 91 h. 1. g0*.r. . * t) -blir 5. -,1 1. qi. ''',.4-Ifi •rtli 4... •I'.,11)..4 r= '5 ... ..;! 5`:1)Si r '...N .., • 4 5 ',.. k i sl.s , :4 •, 'iii 17 Ai 7. 1-e,..•4 kyr, 4: .t _ . 1 :: Ad•1 ' e..,. I •1 • . I MAP REFERENCED FROM GOOGLE MAPS , 1 II\K I 1 , I \ • I Date: 8-30-17 f By: is Scale: As Shown Project , (1„'.4.--;;(:_.);-11-1-i'';:a[1 ,$' .,ii---4,F1110--,'-f.''''=.1 , rirl,:.,114,-.:i.:, -- .,, VII(7;14411-11-Y MAP 17-04'26 1 741 Marine Drive 1 ' Bellinghani, VVA 98225 .,-'''A.11fit.,I__ti, ADu Figure 'l phone: (360) 733-7318 2202 1 6TH STREET fax: (360)733-7418 ANACORTESI WASHINGTON , 1 -- PROJECT LOCATION te- p ` . •... a Aide 1 - t '� C • ' - S.' _ R = 1 w ,�, h I i t, yaw+ewe • 1 41 IIM . • 1 i • la -- ilit 15th Street p i.a.,, ...Ili Alb, .kitilrii MAP REFERENCED FROM GOOGLE MAPS ASt TP-# =Approximate Test Pit Location N Date: 8-30-17 By: JS ' Scale: As Shown_____ Project GEOTEST SERVICES, INC. SITE AND EXPLORATION PLAN 17-0425 741 Marino Drive Bellinghanl, WA 98225 PADILLA ADD Figure ll phone' (360)733-73182202 'I5TH STREET fax: (360)733-7418 ANACORTES,WASHINGTON 2 Soil Classification System Uses MAJOR GRAPHIC LETTER TYPICAL DIVISIONS SYMBOL SYMBOL DESGRIPTIONSt'k21 GRAVEL AND CLEAN GRAVEL o °.tr D.o Q b GW Well graded gravel;gravel/sand mixture(s);little or no fines .I N GRAVELLY SOIL (Little or no fines) �0 5 .�,i o. • o., Gp Poorly graded gravel;gravel/sand rraxture(s);Tittle or no fines 0 •®l (More than 50%of J 1 Cacoin se fraction retained GRAVEL WITH FINES ) , ' t.' GM Silty gravel;gravel/sand/silt rrnxture(s) 2 E o on No,4 sieve) (Appreciable amount of ^ N fines) . . Clayey gravel;gravel/sand/day mixture(s) 4cz 0 d wSAND AND CLEAN SAND SWWell-graded sand;gravelly sand;Rile or no fines »�r SANDY SOIL (fie or no fines) . . W w SP Poorly graded sand;gravelly mad;fide or no fines 0 ta (More than 50%of SM Silty sand; sand/sift mixture(s) coarse fraction passed SAND WITH FINES I { ) through No.4 sieve) (Appreciable amount of fines) • SC Clayey sand;sand/day mixture(s) Inorganic silt and very fine sand;rock flour;silty or clayey fine —1 . w SILT AND CLAY I ML sand or dayey silt with slight plasticity 5 o m Inorganic day of low to medium plasticity; ro U o � I� Y; gravelly clay;sandy © N (Liquid limit less than 50) day; silty day;lean day W c' d )/ 2 a QL Organic silt;organic,silty day of low plasticity ce 2Mil Inorganic sift;micaceous or diatomaceous fine sand "' SILT AND CLAY W CH Inorganic day of high plasticity;fat day (Liquid limit greater than 50) u- OH Organic day of medium to high plasticity; organic sift HIGHLY ORGANIC SOIL PT Peat; humus;swamp sod with high organic contentaaaaaaaaaaa �^ .-.._ GRAPHIC LETTER OTHER MATERIALS SYMBOL SYMBOL TYPICAL DESCRIPTIONS PAVEMENT AC or PC Asphalt concrete pavement or Portland cement pavement ROCK `' RK Rock(See Rock Classification) VIrevir WOOD J'" � WD Wood,lumber,wood chips A i A A DEBRIS � DB Construction debris:garbage n n n � Notes: 1. Soil descriptions are based on the general approach presented in the Standard Practice for Description end Identification of Soils(Visual-Manuel Procedure), as outlined in ASTM D 2488.Where laboratory index testing has been conducted,soil dassifications are based on the Standard Test Method for Classification of Soils for Engineering Purposes,es outlined in ASTM D 2487. 2. Soil description terminology is based on visual estimates(in the absence of laboratory test data)d the percentages of each soil type and is defined as follows: Primary Constituent: >50%-"GRAVEL,""SAND,""SILT,""CLAY,"etc. Secondary Constituents: >30%and<60%-"very gravely,""very sandy,""very silty,"etc. > 12%and<30%-"gravely,""sandy,""silty,"etc. Additional Constituents: > 5%and<12%-"slightly gravely,""slightly sandy,""slightly silty,"etc, 1 7Z 5%-"trace gravel,""trace sand,""trace silt,"etc., or not noted. Drilling and Sampling Key Field and Lab Test Data SAMPLE NUMBER&INTERVAL SAMPLER TYPE Code Description Code Description Sample Identification Number a 3.25-inch O.D.,242-inch I.D. Split Spoon PP=1.0 Pocket Penetrometer,tsf b 2.00-inch O.D., 1.50-inch I.D. Split Spoon TV=0,5 Torvane,tsf S-- Recovery Depth Interval c Shelby Tube PO= 100 Photoionization Detector VOC screening, ppm 1iiip 11�e-- Sample Depth Interval Grab Sample W=10 Moisture Content, % JJ a Ottaer-See text if applicable D= 120 Dry Density, Fcf Portion of Sample Retained 1 300-lb Hammer,30-inch Drop -200=60 Material smaller than No. 200 sieve, % for Archive or Analysis 2 140-lb Hammier,30-inch Drop GS Grain Size-See separate figure for data 3 Pushed AL Atterberg Limits-See separate figure for data 4 Other-See text if applicable GT Other Geotechnica/Testing Groundwater CA Chemical Analysis Q Approximate water elevation at time of drifting(ATD)or ot,date noted. Groundwater ATD levels can fluctuate due to precipitation,seasonal conditions,and other factors, Padilla Adu Figure c7e0-re ►T 2202 15th Street Soil Classification System and Key 3 Anacortes, Washington TP-1 SAMPLE DATA SOIL PROHLF GROIJIMD s r 1, ..0 N o Tracked Excavator E c g Excavation Method: H nn co cn Ground Elevation (ft): Unknown CI :c c�� co. cEcqq c E (, C0.) 0 to to Uy f- (9 0 7_, pl. Scft,brown,moist,organic SILT(Topsoil)1-1 dSlut Loose to medium dense,frown, moist, very silty - 1-211 d GS i to silty,fine SAND(Weathered Till) c —2 — 1-31r d OS slit content decreases,becomes coarse to tine SAND _1 U _ - a - r '' f �IIL d Gs f_j ' 2 Slight 1-5 d ! ML Very stiff to hard,moist,bluish gray,sandy SILT }� with pebbles and cobbles(Glacial Till) a 1-6 lir d s 8 Test Pit Completed 06/27/17 S Total Depth of Test Pit=7.5 ft, Q j 10 a a. A 4 TP-2 ix SAMPLE DATA "self.. PROFILE GROUNDWATER i. - 1 co i- ' 4 Tracked Excavator Excavation Method: 11 Z }" ors 6'z To a, aa) a.i m o Ground Elevation (ft): Unknown o ss.as a c c to Q. E c E Ti; U 4.o Ll (o ea co to 1— C7 D 0 DL. Loose,brown,dry,slightly silty,fine sand with 4 2-1 `$ d organics(Topsoil) o SM Loose to medium dense,brown,mist,very silty �..•_ to silty,fine SAND with organics(Fin) __IIa 2 2-2141 rt (GS . SM Loose to medium dense,brown,moist,very silty ..,rc to silty,fine SAND(Weathered Till) _ii z. 7 w 2.4 } ML Very stiff to hard, moist,bluish gray,sandy SILT `� tyi,� I with pebbles and cobbles(Glacial Till) a 2-- ! ri OS o 1.1 1 Ii 1 - aIt _ 2-4 it- d L 1 --8 Test Pit Completed 06/27/17 Total Depth of Test Pit c 7.5 ft. o u) - w 10 6 U n. ix Notes: 1. Straligraphic contacts are based on field interpretations and are approximate. rT 2. Reference to the text of this report is necessary for a proper understanding of subsurface conditions. 75 3. Refer to"Soil Classification System and Key"figure for explanation of graphics and symbols. rn Padilla J$.dLl igi.iri.11\,,...7eol--(7,-.--1; T 2202 15th Street Log of Test Pits Anacortes, Washington (i opt 2) TP-3 _. l R. ,1;'1,4PPLE DATA SOIL PROFILE GROUM 1vdATER aExcavation Method' Tracked Excavator 11 a LIP cwn Ground Elevation (ft): Unknown ci.Ca C E w (°r3 0 u) /i (I) I- C)—n . SM Stiff,brown,moist,silty,medium to fine SAND 3-1} _ d GS with gravel and cobbles(Fill) ,_2 S or Soft,black to brown, moist, organic SILT(Relic - 3-2 d GS SM ��,Topsoil) ; Lode to medium dense,brawn,moist,very silty cD _ to silty,tine SAND(Weathered Till) Si) _ 3-3 cl sill content decreased 1- u ^� a I silt content increased -II r- f J Q _ lit. Very stiff to hard,moist,bluish gray,sandy SILT !ir trl J 2 - with pebbles and cobbles(Glacial Till) a Test Ph Completed 06/2'7117 5 - Total Depth of Test Pit=7.5 ft. 5 -1 n _ 0 )C. cc co 0 0 y V) of IY c v) U) L 0 w Cc LL a a 111 f.- O CAI CO 0 a a lic 1 0 0 w (.0 U I— D ) of Of 5i Notes: 1. Slreligraphic contacts are based on field interpretations and we approximate. `` 2, Reference to the text of this report is necessary for a proper understanding of subsurface conditions. r 3. Refer to"Soil Classification System and Key"figure for explanation of graphics and symbols. C[) oec Padilla Adu Figure }�I i 2202 15th Street Log of Test Pits �.� Anacortes, Washington (2 o(2) i U.S.SIEVE OPENING IN INCHES I U.S.SIEVE NUMBERS I HYDROMETER 6 4 3 2 1 6 1 3,4 1/2 3 6 810 1416 20 30 40 50 60 100140 200 100 - ,I �~ _ M V : k90 _ _ ' ' �. 80 ___ _. • : ' i : 1 70 - - -- _. _ - 1 - _ a ~ z60 '61\ �, ii .. _ az ..- ) UM g i2 50 , w • . ' ' \ . a rs 40 - - • 1 30 _ _ n VIII r a 20 - � • >- 10 k• - CC a , ! - -. w • • p O' i z} 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters o PCobbles Gravel Sand p coarse fine coarse medium fine Silt or Clay cn i F Point Depth Classification LL PL Pi Cc Cu 0.140 TP-1 1.0 Silty, fine SAND (SM) z I TP-1 2.0 Slightly silty,fine SAND (SP-SM) 1.43 2.42 w .... A TP-1 4.5 Slightly silty,coarse to fine SAND with trace gravel (SF-SM) 1.52 1.52 5.35 a;* TP-2 2.0 Silty, medium to fine SAND with trace gravel (SM) O TP-2 5.0 Very sandy SILT (ML) o -67t oarse %Fine %oerse %Medan) --IX Fine L.L I Point Depth D100 D60 D50 D30 D1a Gravel Grave! Sand Sand Sand Ai Fines arc, • TP-1 1.0 4.75 0.168 0.137 0.076 0.0 0.0 0.6 4.5 65.5 29.4 8 CM TP-1 2.0 9.5 0.197 0.181 0.152 0.081 0.0 0.1 0.2 0.7 91.6 7.4 o 181 A TP-1 4.5 19 0.776 0.632 0.414 0.145 0.0 5.3 9.1 54,8 23.7 7.1 in I * TP-2 2.0 37.6 0.258 0.191 0.084 5.8 2.9 3.8 16.1 43.6 27.8 O TP-2 5.0 9.5 0.079 0.0 0.7 1.4 8.1 30.8 69.0 a - Cc= D302/(D60* D10) To be well graded: 1 < C� < 3 and Cu = D60/Dio C„> 4 for GW or Gt, > 6 for SW 1,3 Padilla Adu Figure c,eoTeT 220216th Street Grain Size Test Data Anacortes, Washington U.S. SIEVE OPENING IN INCHES I U.S.SIEVE NUMBERS I HYDROMETER 6 4 3 2 VS1 , 1/2 3 6 810 1416 20 30 40 50 60 100140 200 100 ,, • • 80 71.11.1111111111111101111 '' y — • — r - I ' 70 — —' 4-r--- a ".."'c Yalli IIIIIU60 . - — — co .fl • Z las aa , 1 ----'-- ..... ¢ c°'t QU --•imilik J d i :: iMIN r • a 0 t. 111 100 10 1 0.1 0.01 0.001 c) Grain Size in Millimeters P Gravel Sand Cobbles coarse fine coarse medium fine Silt or Clay 6 Point Depth Classification LL PLY PI Cc Cu p_ • TP-3 2.0 Silty,fine SAND (SM) _, z I TP-3 3.5 Slightly silty, coarse to fine SAND with trace gravel (SP-SM) 1.05 4,58 w a at 1- 2 %Coarse - ,,,IFine se %Medium %Fine a Point Depth D100 Deco Dc0 D30 D10 Gravel CiInvz i Sand Sand Sand /O Fines $ 41 TP-3 2.0 9.5 0.182 0.158 0.089 0.0 0.00 0.2 2.6 72.6 24.6 o m TP-3 3,;-1 19 0.499 0.367 0.239 0.109 0.0 9.5 9.4 24.1 50.0 7.0 5 w s9 0 `J - - , U W a m Cc_ Sao/(DG0'' Din) To be well graded: 1 < Cc < 3 and L, Cu = DSD10 Cu > 4 for GW or Cu > 6 for SW Padilla Adu Figure eoTe5T 2202 15th Street Grain Size Test Data Anacortes, Washington 7 ) - is) Northwest Agrict.tkk -., GeoTest Services Inc. ; r ;,.. 741 Marine Drive Bellingham,WA 98225 2545 W Falls Avenue PAP-Accredited Kennewick,WA 99336 509.783.7450 ; Report:41439-1 www.nwag.com lab@nwag.com 0,A P,, Date:June 30, 2017 Project No: 17-0425 Project Name: Padilla Adu _ Sample ID pH Organic Matter Cation Exchange Capacity TP-1 @ 1.5' 5.6 6.34% 118 meq/100g TP-2 @ 5.0' 5.5 7.78% 21.5 meq/100g TP-3 @ 3.5' 6.8 3.65% 6.1 meq/100g Method SM 4500-W B ASTM D2974 EPA 9081 REPORT LIMITATIONS AND GUIDELINES FOR ITS USE1 Subsurface issues may cause construction delays, cost overruns, claims, and disputes. While you cannot eliminate all such risks, you can manage them. The following information is provided to help: Geotechnical Services are Performed for Specific Purposes, Persons,and Projects At GeoTest our geotechnical engineers and geologists structure their services to meet specific needs of our clients. A geotechnical engineering study conducted for a civil engineer may not fulfill the needs of an owner, a construction contractor or even another civil engineer. Because each geotechnical engineering study is unique, each geotechnical engineering report is unique, prepared solely for the client. No one except you should rely on your geotechnical engineer who prepared it. And no one—not even you—should apply the report for any purpose or project except the one originally contemplated. Read the Full Report Serious problems have occurred because those relying on a geotechnical engineering report did not read it all. Do not rely on an executive summary. Do not read selected elements only. A Geotechnical Engineering Report is Based on a Unique Set of Project-Specific Factors GeoTest's geotechnical engineers consider a number of unique, project-specific factors when establishing the scope of a study. Typical factors include: the clients goals, objectives, and risk management preferences; the general nature of the structure involved its size, and configuration; the location of the structure on the site; and other planned or existing site improvements, such as access roads, parking lots, and underground utilities. Unless GeoTest, who conducted the study specifically states otherwise, do not rely on a geotechnical engineering report that was: • not prepared for you, • not prepared for your project, • not prepared for the specific site explored,or • completed before important project changes were made. Typical changes that can erode the reliability of an existing geotechnical engineering report include those that affect: • the function of the proposed structure, as when it's changed, for example, from a parking garage to an office building, or from a light industrial plant to a refrigerated warehouse, • elevation, configuration, location, orientation, or weight of the proposed construction, • alterations in drainage designs; or • composition of the design team; the passage of time; man-made alterations and construction whether on or adjacent to the site; or by natural alterations and events, such as floods, earthquakes or groundwater fluctuations; or project ownership. Always inform GeoTest's geotechnical engineer of project changes — even minor ones — and request an assessment of their impact. Geotechnical engineers cannot accept responsibility or liability for problems that occur because their reports do not consider developments of which they were not informed. 'Information in this document is based upon material developed by ASFE,Professional Firms Practicing in the Geosciences(asfe.org) i GeoTe6T Subsurface Conditions Can Change This geotechnical or geologic report is based on conditions that existed at the time the study was performed. Do not rely on the findings and conclusions of this report, whose adequacy may have been affected by:the passage of time; by man-made events, such as construction on or adjacent to the site; or by natural events, such as floods, earthquakes, or groundwater fluctuations.Always contact GeoTest before applying the report to determine if it is still relevant. A minor amount of additional testing or analysis will help determine if the report remains applicable. Most Geotechnical and Geologic Findings are Professional Opinions Our site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoTest's engineers and geologists review field and laboratory data and then apply their professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ—sometimes significantly—from those indicated in your report. Retaining GeoTest who developed this report to provide construction observation is the most effective method of managing the risks associated with anticipated or unanticipated conditions. A Report's Recommendations are Not Final Do not over-rely on the construction recommendations included in this report. Those recommendations are not final, because geotechnical engineers or geologists develop them principally from judgment and opinion. GeoTest's geotechnical engineers or geologists can finalize their recommendations only by observing actual subsurface conditions revealed during construction. GeoTest cannot assume responsibility or liability for the report's recommendations if our firm does not perform the construction observation. A Geotechnical Engineering or Geologic Report may be Subject to Misinterpretation Misinterpretation of this report by other design team members can result in costly problems. Lower that risk by having GeoTest confer with appropriate members of the design team after submitting the report. Also, we suggest retaining GeoTest to review pertinent elements of the design teams plans and specifications. Contractors can also misinterpret a geotechnical engineering report. Reduce that risk by having GeoTest participate in pre-bid and preconstruction conferences, and by providing construction observation. Do not Redraw the Exploration Logs Our geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors of omissions, the logs included in this report should never be redrawn for Inclusion in architectural or other design drawings. Only photographic or electronic reproduction is acceptable; but recognizes that separating logs from the report can elevate risk. Give Contractors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnical engineering report, but preface it with a clearly written letter of transmittal. In that letter, consider advising the contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited; encourage them to confer with the GeoTest and/or to conduct 'Information in this document is based upon material developed by ASFE,Professional Firms Practicing In the Geoscienoes(aafe.org) •�w oe0Te5T additional study to obtain the specific types of information they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might you be in a position to give contractors the best information available, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. In addition, it is recommended that a contingency for unanticipated conditions be included in your project budget and schedule_ Read Responsibility Provisions Closely Some clients, design professionals, and contractors do not recognize that geotechnical engineering or geology is far less exact than other engineering disciplines. This lack of understanding can create unrealistic expectations that can lead to disappointments, claims, and disputes. To help reduce risk, GeoTest includes an explanatory limitations section in our reports. Read these provisions closely. Ask questions and we encourage our clients or their representative to contact our office if you are unclear as to how these provisions apply to your project. Environmental Concerns Are Not Covered in this Geotechnical or Geologic Report The equipment, techniques, and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated containments, etc. If you have not yet obtained your own environmental information, ask your geotechnical consultant for risk management guidance. Do not rely on environmental report prepared for some one else. Obtain Professional Assistance to Deal with Biological Pollutants Diverse strategies can be applied during building design, construction, operation, and maintenance to prevent significant amounts biological pollutants from growing on indoor surfaces. Biological pollutants includes but is not limited to molds, fungi, spores, bacteria and viruses. To be effective, all such strategies should be devised for the express purpose of prevention, integrated into a comprehensive plan, and executed with diligent oversight by a professional biological pollutant prevention consultant. Because just a small amount of water or moisture can lead to the development of severe biological infestations, a number of prevention strategies focus on keeping building surfaces dry. While groundwater, water infiltration, and similar issues may have been addressed as part of this study, the geotechnical engineer or geologist in charge of this project is not a biological pollutant prevention consultant; none of the services preformed in connection with this geotechnical engineering or geological study were designed or conducted for the purpose of preventing biological infestations. 'Information in this document is based upon material developed by ASFE,Professional Firms Practicing in the Geosdences(asre.or9) �Y 741 Marine Drive Aelhngham,WA 98225 360 733_7318 oQTGsT 20611-67*Avenue Arlington,WA 98223E 888 251_5276 360 733_7418 October 24, 2017 Job No. 17-0425 Landed Gentry Homes and Communities 504 East Fairhaven Avenue Burlington, WA 98233 Attn.: Steven Baughn Re: Stormwater Infiltration Evaluation Memo Padilla ADU Development 2202 15th Street Anacortes, Washington Dear Mr. Baughn, As requested, GeoTest Services, Inc. (GTS) is pleased to submit this memorandum disusing the effects of stormwater from the proposed infiltration trench on the adjacent residential foundations. It is our understanding that the City of Anacortes Planning Department has concerns that the foundation setback distances from the trench might not meet the suggested guidelines put forth in the 2014 DOE Stormwater Manual for Western Washington and may have 'a significant negative impact on the surrounding foundations'. The manual suggests that infiltration trenches be placed at least 20 feet from uphill foundations and 100 feet away from downhill foundations. The proposed infiltration trench is to be situated 20 feet north of the proposed residence on the subject property and runs east to west for 46 feet. The existing residence on the neighboring property to the north is 48 feet away from the proposed infiltration trench. Topography on the property slopes gently downward to the north, dropping approximately 1 foot in elevation from the trench to the neighboring residence, giving a gradient of 1 degree or 2 percent. Based upon the relatively flat topography and the fact that the upper 4 feet of the existing site soils contain weathered till that can be infiltrated into at a rate of 1.5 inches per hour, in our opinion, it is extremely unlikely that the location of the proposed trench would negatively impact the surrounding foundations. Page 1 of 2 GeoTest Services, Inc. October 24,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 We appreciate the opportunity to be of service to you on this project. If any questions should arise regarding this report, please contact the undersigned. Respectfully Submitted, GeoTest Services, Inc. `e `Wasfps,*; °o 0 C�,\gisee 420I i �4 - Tim Chylla Tim Chylla, L.E.G. Engineering Geologist Attachments Figure 1 Vicinity Map Figure 2 Site Plan References Washington State Department of Ecology, 2012 (amended December 2014). Sionnwater Management Manual for Western Washington. Page 2 of 2 . PROJECT LOCATION I1 ,-sue • i 1 �f ' V.a . t... ii":: Crocer Ail, ` ! ' O I }!l a i s ,. its f , AIr• s i am r ` ... f s r ,r., '' > ,, • .s Ir' .Iil ' i i. ., MAP REFERENCED FROM GOOGLE MAPS N Date: 8-30-17 By: JS Scale: As Shown Project GEOTEST SERVICES, INC. VICINITY MAP 17-0425 741 Marine Drive Bellingham, WA 98225 PADILLA ADU Figure phone: (360)733-7318 2202 16TH STREET fax: (360)733-7418 ANACORTES,WASHINGTON I AR R RE0t TEC :. EGAL DESCRIPTION: -..r.� — mow" Y r'c --' - 7*+ •CASr ertr Cr tor 17. ALC.YG rear P11. Cr LOTS re. - - a :3, AND Yc'. OF d_CCX :EDS. AS PER SURE'. RECORDED uAL:. ? 4.,J.7,:.0 5 f1.E latSIER 200.103170756, RECORDS - 0r _,A7fr t:;1:% Cr• ETA if 4K H'A9,.NCCTQV. - i . ;. N D l : U - 1. - 1' RI SMPC213 SILT FENCE • " PERIMETER SILTFEiCING •. .1 . ..v •- I . 1 , IC PROTECT aOWNSTREAJ/ GENERAL NOTES PROPERTIES • LA4E. GENTRY • 504 E. PAGINA eistagaren. WA 6'H.S. 982.17 1-13601••755-9021 ALLEY ,Q3 ..7-- - - _ - - -- - -. 3LoLtVIN TLAREA_ -- - - LWRR ;Ev'.i MFw 'ap 3 Il .. GARAGE - 855 Sr Se OW :Pl : Tl?7CAL F•Wt. - ,L„. •w-�Y+,. - - - r ZUWt:@ poi C724. CH1t<G =--•� Z ?2 - RF90ENAAt LafV raNs:>v • I arw--.— Ni YOIO 111 G A11. CKS :N COI. U j ' ��jrEQ�+i�y _ ANCE II -- - .-_ - _ B.ADING St-MACK:11 - � - e + + 1 pNYi Tits LWET'F7 - --a.- -_� -- LI SMP C2.1 SILT PENCE .'. >: �r I FRaNr YAAS A^I11r; 2n' cAGAr,•E Pe"Ri UT:TER SILT FENCRG • ••. TO PROTECT DOWNSTREAM Wr./-An •1 •- = -,/ 0. f! PROPE4T'ES . °T. a VS`I POGO. VAX Au Ad 5• am =D• TER ,:=c� 2 G p PAY GARAGE,ARAGE, : IM OMf_'1W`• r I P56250 I. a I . ;,o COVERAGE I ; 2202 15th L. c AREA: WI Sr . I it ,5 POPCPCS }e? Si: Ai:- ` I III n i ? WAS ARE: J10/1 Sr. S5f7Arx:M I _. :, LOT AAfA. 74a7J SF �; 1 L J.. • V V LC tY Wirti ur NIL!PA CW ri, AS: flacon COIER.ALL . I 1 '— \._ (1 I b R Mfi- Alb 5. Jr en /4aTf .737X I <2. d U9r.:H Iaalfuro AAY a A.1: LfA7.wtW ALLOIED. 1.0R .II' Iw r 3 E',-`q mot. Ap�NLOCl NW 1 GAME - }1 a.r�srror r51b1crMTMrras IMPERVIOUS COVERAGE I II 7, Q a .6TYML /MLM � rM iirOtl[[ :ZIT W GL+mnw 't1 HW[P.'A� 7,dJ'} S.F. t K I Yf r?•/f17.0[D NIL. ..bV .I Y •' .. • >6 •r J- Trrne2 w SIYr/q 4 riCt.swr i I i ''IIA vA [n w`/vi A4AWWALKwAY, i�Sf .1 __—� I 3 =An.srwnc m iuA Mi. /2V PORCH: ]Q S.F.r� 1}-- I ' LAM P ROf 728 5.F. II i . . 1 '_.. Pn i I I I K 1rvow'a�'mi .�ciiaaOg•r1 ADV{W MAW rtiA'Dale �T;0 SFf. I ; ai•3r. ! ! - y%r t ' ists• /sire NW .}v,Kfio R }u♦L' r•• 1.f.i. Sl 702., tlu caa r me . 1 •-- : Y• Alan, r> wlu +ur as r: NaU,CAY I _ micro fy as NR tl� M WI :?f AFEA arq Gq7 S '1RtF Ker me.n nwl✓A >Qf7S SF. � 3 CC T.TIEN7t^,f O1 .r.T A.M.!1a u� gt• uir s17 8•�St >.AC. pAN!i'AwTX Cr NOT. - NaUfAa`I? __ .` nRAS&irr.,. S OC1.e'.e P"_RC'EtiT C'344 A= SADr�j ,. /'� a•!GAC1!I_�tr iov m, *von* o..w •a aim Nagai .lstta / 14,1r . J7.RS ' / '�.1 +o�NA.Ma x�N ywA. Mai SILT FENCE sip L72�! w S. Iry L '/ . k< • •KO•stf PR KAMMO B01PeARY ,I . .. . , ,_r. . .yY. ,. . ,...,.. al ; felvALnr T.r SOIL STO�ILE 2a E'll'PYA� LOCA:ON Ewer • �. 1,..,. r.. r...... ._•. ,....•. _ .- : .r..r.. 'a- �- j I PLAST DCOVER URING Mr" r 1■■ . _ T EMP C105.STABILIZED •! I , STORM EVENTS. '_' „_ ,F;-, .;,'. " "••••�•"�'• J CONSTRUCTION • / BAIP G1Yo.PLAST - , • ,• _ . � , <• . ..••".....-:,,. :Ar 1 ENTRANCE - -- 1 j CDVER*JG) O -a•- - .,•,...r.- ,..., :AO! (S1ZETOFRI :,�C : / I. > LT.Tv z • r --- ,YG 1 t . W. ADA �..�.. M� -I` -I- -".. I -f_• _ - HF1P Ca21 - 4. • TJ£ - n ,. ry..•,' ,1.•YN .. _ __ _ rrr _ '.`.:: f.,.c•. y. . I - °4vtw.w • K GRAPHIC SCALE w"°` — -- _� _ zv . 70 0 5 to 20 a1aGclw HIGH VISIBILITY r at 6 REDUCE RISK OF Pueuc CONCRETE DRIVEWAY - • lte>+r. Stray: T Inch 10 Feat . -py:is ENTRY INTO CONSTRUCTION SURFACE TO BE CROSS SUP CM:HICJ•ASI S U? ;••L1,T,1,-Al CITE SLOPED 1%MINIMUM TO IRAS=FENCE�f� r�RISK OF PUBLIC •WI - �ADILLA AOU PROMOTE RUNOFF TO BE —E1HR 11AA�30NSTal;Gu9A' 3-CAR GARAGE CENTER 15TH STREET b sPERSEOaNrl71NRtG:= �, — — _,a�1�;R — _ _ LAWN!MOWS AREA 1 Y'. a.... J EROSION CONTROL PLAN I / �ro.E. & LID IMPROVEMENT PLAN • . .'c. - P56250 • 2202 15TH STREET :x,Ia : -• ` ANACORTES, WA am* PLAT CS'411 NORTH" B361LY: _ IC WI 101322017 t i e __• _--- __..r___ . . _ .— --. _- - _ _ . _ _ .__ _ - - .- C..r,- of 2 - _- - _ _ - i - -r• CAST ,:IA or for 17, Atom; WITH Ai L OF _C'3 le. :U, .at•D 2C. BLO:C 20E, AS PE4 5VkF_'/ xiRD5C !!- . .'c:7 ALO,R'S '•aE 4AWBER 2003031:03E5 RECOPJ75 7 S<7,S% CCA:PGY,, 3 4a Oc PWASr • r a T. A N ll 1. ll G li a T RI' - ♦ .r . .. v •al vr . l 8MP03:SICT?EYCE PERWETER SLIT PE' IMIC TO PROTECT DOWNSTREAM f i TES PROPERTIES (10AM• i . —- LAA_.EC env BURLRGTW. IPA < - 3•r:F r: ARM • - r-Gre0E-77c�-9C2r ALLEY }I �' • 1 . _. iv-'.r ta.rR CE12E AREA- ton Sr ,il UPPER lrA. G AREA- - �'] sr -- -� - - - . . rri4 VAN; Mrs- y11133 % _— - -- - . - ...-I r .—._—.—_------ �� _.— _.._ II . . CSOCRACC - BSI Sr fl CAL !A] U .• • _ mei 2 R2 - Ats-CE ;uL LOW Jr•+:T7 slLPIcrs+ a'nC °fan CAUL y -�� . .•, Ors W rnvP:iARCF ` I I - no1T.OXJs+vtrtxf f r i{ weft p'r Gu.»wEs JI iid'IO:EI84CFLAi I •- SOETAPOS YT S., rS• Wale ACAR WO AN .30• 1 — �. -_ •_ ._ .. ... . f 'C r ?MO WA Jr.. 20• SAUCE BMP C233 SILT PEACE - 1• Ir I� i PERIMETs.R SIT FENCING I -- • TO PROTECT DOWNSTREAM • 1 '5 , ----• . < .rEla.r. PROPERT'ES • .I �Ettt i '^ 7> P• WAX Aj OJC 3 I " • • ii: 1. • B 1 a�5a _ @ - = for COVERAGE i I f 02 1 5Th St. �i - . : BIRe�xG MCA, zesl Sr. I PGROfL$ Wen sr - ^ I'741lh 1: • !�.'�'' TOTAL MCA SOU' Si :r:T.^•SSAE I V ----("-71 Ap;.r. ^ Li for AREA: Mtn SF :mci: a I w� �;, b CLObtr .S.L. APGN NE et PfRCENr cVERNiC KII+A:R:K I. I T`� ' y i u GC AaP'Aw- .i.705 F!' S,OTu / tadrs - 257x Ifr •'• �r �I '4rz $ 5 FL, moor YA+NNM ALI01M nor • •i • c w non roil wa0~'to RC I 1R.a II 6° ,, e egr r M: �S!T;r IMPERVIOUS COVERAGE' U �- fl -...• vor .sat .trrr. Iva s*snu PO I II . W MEMO A " T WApLYG: 2,8S1 Sr ' II I •I I C nary.' :,°f�°Amr �R''a! """a"" MU unurxwr rue Sr • I U - ✓ mar Ulan Avw1� A+tt� lw!Y IYACKW4 YF 40 SF I• _ .��. J• F y 7K wtIl S.fiJ Wv C2Sr. I N. 4 I -- I Y SOW AOU DECK: 0 • ,��77�lapy�¢It� �,� r>9 tftrident err seat a. 01 if . I - . I- l• '-' - . .•`/'ry"•` • ' 7 �t AMxorfaafar my 1,3.m Kas eit 1ST RASA: 1 L —r • 4MLRRM1r Vl�.' 9aalxE L Bel sF .:4. wane L $Io oft �' SO) iC(T! SF. Ill • / !Ala;ifb 03 7CW R'i1TAY •XC °'� PERCENT COIEQAU.'E:. 1G.Oa'I• vEW.I^l:.'.A'. Fi00(ari vise+ ono ad v. .ree nc,aaa MIL / 14175 s _7.e! f aryu.�! ea%1 . . ...H : e..raw. Earacz ' C — ICFItaO awn• A ��' PERueus MTV S.T I Eta ' 1 9µP 021- • w MOPeT•7m • ..f• •• S PROPE.RY eSUHL VY v BLteM' .. _ ..r"+.- .�. -'•'•+..•• / LCCATON 7`L5 l a ;COVER Wt1)- - _.. ;_ :-.r.- . —. - - t• +_ o ( PLASM OI1RIAti —_ _� - BLIP C:OS:STABRI:m ' ' STORM E1 c'r i 5 r S . ... ... . ... . .. _ r,. B�•!7RFN Oy 6 I EBP C'.Y3:F Ju'�IC F- .--. . ono,rr . (S1ZETOFfi - L_ 'x• •• . . 1 -- '• m o�'T•' Z _ _ - : A I • ., ... I e : 1 - gtr MP C-21-NLSLC`r''hti'`— K F! Ie.vr ... ..�.•. VJ --. .nh'.:r•'•..Y.. I . � AT - • .. /L .' , ':.1 ?� •SRO • - - BAP CIG3t FRGH v1512LJ' TY sets. Soak: 1I-nc l PO feet "OREDUCERIEKCC PL1BUC CONCRETE DRIVEWAY .• . � V TYo- EhTTRvKMCONSTRUCTION SUIYrlaTOBECRCrSS BMP�FSnC CE1•G19os!'Y PADILLAADU rt:s_ftr c. S'E SLOPED I%NIKAIULL TO TO REDUCE RTS'A OF PUBLIC _ '— PROMOTE au BE •e - - '�I�" - -- -- - - -- - - -- --- -- --- - _ 3-CAR GARAGE CENTER 15TH STREET LAWe•rLA.YOSCAPEAREA sIT> "`"� ` . CONTROL & IJD IMPROVEMENT PLAN BOLa5 P56250 2202 15TH STREET ANACORTES, WA a v:. PLAT Of'AS NORTH- ." cm 1G .. - am 10:32:2011 - Iof2 - - - — --- -- — — — -'- — HOUSE-WWHM VIEWS AND REPORT I WW.4M3 vn'r:lnt;.`":o°.:se2 ie c.:,: -sierw ie•.p 0 ' ' 8711 aM .L.L.1-2 �' ',1,„Irill6t;11 i SCE'G_ I__ .__... a� B�SfIt red pe �t t;!OS —I ,. Subbasin Name. IBasin 1 �° —� Surface Interflow Groundwater Mitigated Area in Basin �+�tow _Selected' t • Run scenario ; ;. Available Pervious Available Impervious id G F 9 FM FNTfi I: txest A-ei'y j Oil ;v r*WiFFsinAT i 0 i MINIK MIMI` -.-- 1:: OM ...- -, I =I, 1;! 1 -r 1 i ,_.,,„ ,,, k__ , , Eli" di r,i El@ - , EE ii I; ii Move Elements 411 - Peni�cusTota �7 077 Acres Ac es ___ Irnpetvious Total Ip �: res 4 ---- �►4---�-� Basin Total A tJ77 JACTP+s Save xy; Load xy s it. -l- -l2. —----1 ' Deselect Select BY Zero GO 9/27/20n1 r" 3:17PM I-NWHN,13 wo?r,3 use2 — - — —--- - - - -- - ie E Vet:: Ter, IOW..1 : '1 4941at ' 1 I i.} 11 �; '�' .,�'"�'- i ID -is I ir - - -. SCENARIOS L `j S Ibbasin Name. 'Basin # j r Desrgnate as Bypass for F0C i i Prede�+eloped ""` 1:1 Surface Interffow Groundwear • FEows To : !drays!Trench Sed1 _ !Gta :el Trench Sed 1 I `- --•--..._ _— 0 Ares en Basin 7 Show 01.ir Selected Run Sceneno Ava 2bk P_e�rious Available_Impervious _Ft FMFNTF; - C.rrlr� yak [ ;v ROOFTOPS FIAT 1 ..a77 il 141 i,„...,-41.,,,, UH ililiiiZ , DiLR9: romm . f.,;,, ' ,, .. ... Mcvi Elernehts PeNleusTate 1I3 ,....._. ! Acres IrnpewiousTotal QU77 - Acres ..._�k.�. Basin Total h-077 1 des L_ ---- 3a.ve xy Load xy. 14 i Y-i x 40 s t ,713 —I Deselect Zero Select Br GO 1 vl 02 ' PT vill 'grill I t1TW l3 VAirrlIM3Ho _ :e Set v!e% ZGcrr ei ) lam ® a - i.� �='� III■ r_!.111-- kih-- J ..LIDI �..f•..�,�-.�.R-..�.,�. t.P5 _O x-._ r . .ter,-_•.. _ :-ti-.�: �_�z..,.-,. _E LIAR[t)S - ;i CS t i i Facility Name Gravel Trench Bed t • (-' Predeuetaped I ---° . Outlet 1 Outlet 2 Outlet 3 1p..4,:kgt-,11F.••.: I i Downstream Connection Run Scenario� 0 T' I� l Facility Type GravelTrench/Bed 1 Preapitnnott Applied to Fact* Quick Trench ._ _j i � .. " Eva��oration Applied to Fa,a4 FI F[i111Fl11T4 Facility Bottom Elevation (ft) 0 1 0 E® Facility Dimensions Trench Length if Outlet Structure 1 Trench Bottom Wdth Risser (fCf} 12—�� RiserDiameHeightter(in) 2 i; Effectiv. eTotal Depth :.3 EN L_I Bottom slope ofTrench ;0.0)1001 Riser Type !Frei— 12;: . 1 Notch TypeDI; - Left Side Slope ;p Right Side Slope :tt 1` i 1 Material Layers for Trench/Bed Layer 1 Thickness(it) 2• Once Diameter Height ( Max Layer 1 porosity i0.39 Number (In) (Ft) (cfs) Layer 2 Thickness(ft) n i0 _t_i Ie e j 0 Layer 2 porosity :0 2 l0 1 o- -e i 4 Layer 3 Thickness(ft) ;D 3 F.—- j0� 0 Layer 3 porosity 4 Trench Volume at Riser Heed(acre-it) .001 Sit Elements Infiltration 'ES --i Measured InfiltrationRate 6nJfrr) 6 —_ Pond Increment 1110 •r-I -I 10 i Infiltration Reduction Factor(nfitt`factor) i1"`�..!---1 Show Pond Table OpenTable =c �, I tfseWetted Surface Area(sidewalls) fyES �=1 .l Total Volume Infiftrated(acre-ff) 6.807 Total Volume Through Fadlity(acre-fl) 8.807 Soya xy? o xv' 4 ! 1 ��f Total Volume Through Riser(acre-ft) 0.001 Percent In ttreted 100 l .__ _ �.�._ ._ ___ _. __._. _r._.__. _..__ _.__ —_ • Oi *3 .:. P31 II Western Washington Hydrology Model PROJECT REPORT Project Name: wwhm3House2 Site Address: City • Report Date : 9/27/2017 Gage Burlington Data Start : 1948/10/01 Data End : 1999/09/30 Precip Scale: 0 . 83 WW14M3 Version: PREDEVELOPED LAND USE Name Basin 1 Bypass : No GroundWater: No Pervious Land Use Acres Cr Forest, Flat . 077 Impervious Land Use Acres Element Flows To: Surface Interflow Groundwater Name Basin 1 Bypass : No GroundWater: No Pervious Land Use Acres Impervious Land Use Acres ROOF TOPS FLAT 0 . 077 Element Flows To; Surface In terfl aw Groundwater Gravel Trench Bed 1, Gravel Trench Bed 1, Name . Gravel Trench Bed 1 Bottom Length: 46ft . Bottom Width : 2ft . Trench bottom slope 1: 0.000001 To I Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer : 2 Pour Space of material for first layer : 0.33 Material thickness of second layer : 0 Pour Space of material for second layer : 0 Material thickness of third layer : 0 Pour Space of material for third layer : 0 Infiltration On Infiltration rate : 6.33 Infiltration saftey factor : 1 Wetted surface area On Discharge Structure Riser Height: 2 ft. Riser Diameter: 12 in. Element Flows To: Outlet 1 Outlet 2 Gravel Trench Bed Hydraulic Table StageJft) Area(acr) Volume(act-ft) Dschrg(cfe) Infilt(cfs) 0.000 0.002 0.000 0.000 0.000 0.033 0.002 0.000 0.000 0.014 0.067 0.002 0.000 0.000 0.014 0.100 0.002 0.000 0.000 0.015 0.133 0.002 0.000 0.000 0.015 0.167 0.002 0.000 0.000 0.016 0.200 0.002 0.000 0.000 0.016 0.233 0.002 0.000 0.000 0.017 0.267 0.002 0.000 0.000 0.017 0.300 0.002 0.000 0.000 0.018 0.333 0.002 0.000 0.000 0.018 0.367 0.002 0.000 0.000 0.019 0.400 0.002 0.000 0.000 0. 019 0.433 0.002 0.000 0.000 0. 020 0.467 0.002 0.000 0.000 0.020 0.500 0.002 0.000 0.000 0.021 0.533 0.002 0.000 0.000 0.021 0.567 0.002 0.000 0.000 0.021 0.600 0.002 0.000 0.000 0.022 0. 633 0.002 0.000 0.000 0. 022 0.667 0.002 0.000 0.000 0.023 0.700 0.002 0.000 0.000 0.023 0.733 0.002 0.001 0.000 0.024 0.767 0.002 0.001 0.000 0.024 0.800 0.002 0.001 0.000 0.025 0.833 0.002 0.001 0.000 0.025 0.867 0.002 0.001 0.000 0.026 0. 900 0.002 0.001 0.000 0.026 0.933 0.002 0.001 0.000 0.027 0. 967 0.002 0.001 0.000 0.027 1.000 0.002 0.001 0.000 0.028 1.033 0.002 0.001 0.000 0.028 co C 61 O C) H r{ N N cr) M 'dc 'cr Ln Lf) L) lfl l) r N CS) CO 01 G1 C O r-1 .H N N M M M do �+ Lf) Ln to lQ N N O O C 01 4 O H c-C r-f N N M M d+ V in N N N M Cr) Cr) Cr) Cr) (r) Cr) Cr) M Cr) (U C'') CO Cr) Cr) (U Cr) CO (.0 M Cr) do =r+ vc �+ i cl< crc �+ cac szri de •a* ct+ d+ Lr) Lf) in in IC) in Ln t.f) IC) LI) Ln Lc) 0 0 0 0 0 0 0 0 0 0 0 0 0 O O O O O 00 O O O 0 O O 0 O 0 0 0 0 0 0 0 0 O 0 0 0 0 0 O 0 0 0 0 0 0 0 0 4 00 4 0 0 0 0 o Q O O a 0 0 0 C? O a 0 0 Q 0 O O O O a 0 0 Cl 0 0 0 0 0 0 0 0 0 0 O O C O O O O O O O O O 0 0 O O 0 0 0 O O O O O O O O O O 0 0 0 0 0 0 0 O O O O O O O O O O 0 0 0 0 0) D D cfc Cr) H m H C c+ N .41 O LC) M M .4, 4,0 131 c-1 Sl* lfl 00 M CT1 CO Ln N OCDQ000000CDOCDCD0CDCD00000QQQOQOOOLOWCDNVDNMCDNV> VDN0 cl+ Cal Ln N 0 O O r--1 Cr) l0 O 1n .-1 D 00O0a0O000000oaao00o0o00000000HM LoOoM HLnofMrHLnrnd+ comr • o . . • • • • a • . • • • • e • e e • • e • • • e • e 304 • • • e • • o . Q O 4 0 0 0 O 0 O 0 0 0 Q 0 0 0 0 0 O O O O O O O O O O O O O O 0 0 0 c-i ri r-I i—I N N N M M M .s+ cc vc Ln Lf) LD lD lO N r CD 00 e--I r-4 ri e--1 c--1 i--► e-( r1 c--( .-i rl =-! c-i c-! H 1-1 c-I c-C rl r-( c-1 r-1 N N N N N N N N N N N N N N N Cr) (r) Cr) CO M Cr) Cr) M Cr) Cr) Co) Cr) 00000000 0000000000000000000000000000000000000000000000000 O 0000 00000000 00000000 000 0 000000000000 000000000000040 00 000 • • e s a a e . e • • • e • • a a • e e 0000 00000000000 000 000 000 0000000 000000000000000000 000 00 00 0 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N 0000 0000000000 000 00000 00 000 000 000 00000001000 0 0 0 0 0 0 0 0 0 0 0 000 000 00000000000000000 0000 000 000000000000000000000000000000 O O 0 0 0 0 Q 0 Q 0 0 Q Q 0 0 0 0 0 O CQ O O Q 0 0 0 CJ O O O O O 0 0 Q O 0 Q Q C O O o o CD CD CD O O O 0 o O 0 O C N O 0 N O M N Q M N O M N Q M N O Cr) N O Cr) N O M N O Cr) N C) Cr) N O (r) N Q M N C M N O M N O M N O M N 4 Cr) N O M N O 01 lt) O 01 CC O M lQ O M kO O M l) 0 01 VD 0 CO lD O M lD O Cr) D O M LO O M l9 O (r) l0 O M CO O m O (>') lD O M l{? O (r) O O (r) LD O (r) l0 O M O H H H N N N ( M M cfc cp+ .* Ln (S) Lf) Lo LC) l) r r C- m D CO (3l a1 6l Ca O O e-1 c-I ,-i N N N M rn M c' Q' Ln Ln Ln l0 W lD N N N Cb 00 O Ql 61 H H H H H H H H H H H H H H H H H H H H H H H H i-1 H H H N N N N N N N N N N N N N N N N N N N N N N N N N N N N N 2.967 0.002 0 003 9.256 0.055 3. 000 0.002 0. 004 9.739 0.056 MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.000768 5 year 0.001605 10 year 0.002242 25 year 0.003085 50 year 0.00372 100 year 0.004346 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.003 0.000 1951 0.002 0.000 1952 0.001 0.000 1953 0.001 0. 000 1954 0.000 0.000 1955 0.001. 0.000 1956 0.001 0.000 1957 0.001 0.000 1958 0.001 0.000 1959 0.001 0.000 1960 0.002 0.000 1961 0.001 0.000 1962 0.000 0.000 1963 0.000 0.000 1964 0.000 0. 000 1965 0.001 0.000 1966 0.001 0.003 1967 0.000 0.000 1968 0.001 0.000 1969 0.002 0.000 1970 0.000 0. 000 1971 0.000 0.000 1972 0.002 0,000 1973 0.001 0.000 1974 0.000 0.000 1975 0.002 0.000 1976 0. 007 0. 000 1977 0. 000 0.000 1978 0.000 0. 000 1979 0. 001 0. 000 1980 0. 000 0. 000 1981 0. 001 0. 000 1982 0. 001 0. 000 1983 0. 002 0. 000 1984 0.001 0.000 1985 0.002 0. 000 1986 0. 000 0.000 1987 0.001 0. 000 1988 0.001 0.000 1989 0.002 0.000 1990 0.001 0.000 1991 0.001 0.000 1992 0.002 0.000 1993 0.001 0.000 1994 0.001 0.000 1995 0.000 0.000 1996 0.000 0.000 1997 0.001 0.000 1998 0.003 0.000 1999 0.001 0.000 2000 0.000 0.000 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0067 0.0034 2 0.0029 0.0000 3 0.0029 0.0000 4 0.0024 0.0000 5 0.0020 0.0000 6 0.0020 0.0000 7 0.0019 0.0000 8 0.0017 0.0000 9 0.0017 0.0000 10 0.0016 0.0000 11 0.0016 0.0000 12 0.0015 0.0000 13 0.0013 0.0000 14 0.0012 0.0000 15 0.0012 0.0000 16 0.0012 0.0000 17 0.0012 0.0000 18 0.0009 0.0000 19 0.0009 0.0000 20 0.0009 0.0000 21 0.0009 0.0000 22 0.0008 0.0000 23 0.0008 0.0000 24 0.0008 0. 0000 25 0.0008 0.0000 26 0.0007 0.0000 27 0.0007 0.0000 28 0.0007 0.0000 (114 11) Ord CO (1) U] U] KO CO U7 Cl) CO U] (r) co co co co co co U7 CO CO V1 Cl) Ul co co co C7 O o CD C3 o O CD 0 O 0 CD a 0 C ) C) 0 O 0 O O O 0 03 0) U) U) U) U) U) U) U) Ul CI) Cl) U) U] C!] U] co co () Ul U] Cl) U) co co U) U) Oo00 a o00000000000O00000 ro :LI (U Cd It ro rU id cU rC) rcl (0 ro cG ,CU rt ro CU cUi ci7 IT] (KS cCS ro (0 C) 0 0 Ca 0 0 0 0 O o C] 0 0 0 c 0 0 o O o Q O O 0.4 W W a O4 o4 O4 W 0.4 CL C11 24 CL• ^-L `C-i 114 C14 Q a4 W a 0 0 C) CD C) CD 0 0 0 ® 0 CD C> O C 00 C) CD 00 e • o o < a d e e �, Q O CD 0 0 0 CD 0 0 0 0 0 0 0 0 CD 0 CD 0 0 0 a 0 u� Fj 0 0 0 0 0 O O CD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rJ N N N N N N N N N Lam: N N NCN N N NNN N N CN F T Cr; r- r- r- Lc) is) Lf) Ln LC) •qa+ Cr) (N (N N .-1 0 oCDCOoo ® CQPo000000oo0ooa PIC CI4 C.C) CN LnC3l0N LnLn St' co1-1 O O C) C) a CD CD CD © CD O 0 C ) CD CD o C7 CD CP CD 0 O O O LC) CD LC) N <cr r1 CD rl cY+ C31 lfl Cr) c-1 N •Ct° d+ tS) Cr) r-{ ds CS) LI) CO C) CD O 0 CD CD CD 0 O CD 0 0 0 0 CD O C ) O CD O CD 0 CD c ,�1 f4 Lt') C)1 do O r (N CD CO CY) N c-1 O N if) C31 mot+ Ol b+ C7 LI) CO N C'rl e • • • • o • o . e a v'' 114 Qt Cl Cl M C'4 N N N 1-1 t-! E-; 0-) CO N N CQ Lo LL) Q+ 0 0 0 0 C) O C O CD O O O C O CD C) O O C7 0 0 0 0 •s- -r€ U. �-! } $ LI LC} LC) S9 lCD iS3 r N r CD CO co c r) (3) CJ1 a C> O c-1 1-1 c-1 N N N r'S' a' 0 CD C o O CD 0 0 0 CD C7 C3 CD O CD C7 C > c-•i r-I r-I c-1 e-'i ti O 0 0 O C) 0 0 CD C) 0 C) 0 0 0 CD 0 0 0 O CD 0 0 CD 0 O O Q $ °� 0 ooC) 000000Oo0000O0O00000OCDCD Cf% O cH (N Cr) ';11 Ln LO N co 61 c) c 1 N Cr) szt4L CD LO r- co Cal CD. -3 404 4 u-I s o a < • o o e o co 0 0 o e o e e p a o a o e n o N (r) Cr) Cr) Cr) Cr Cr) Cl Cr) v 'qr cP' u-) L!) E-1 Ts; L] O C ) O CD 0 CD 0 0 0 O O C7 CD 0 0 Q Ca CD C) 0 CD O 0 0 CD U) L7 U) (I] Cf) (n C!) U) V) Ca CI) W U) CI) CO CO Ca U) Cs) CO fa M CO (!) CA CO CO Ca CO CO U) U) Ca CO U) La Ca CO CA CO E0 to (f) t/3 U1 CO U1 CO cfl CT CO CO CO Ca CO ta CO Cl) CO CO CO Cl) CO CO Cl) CA Ca Cl) Cl) (I) Cl) U) (1) Cl] U) U) C1) CO CO CO (j) U) CO CO U) CO Cl) Cl) Cl) U) Cl) U) U) U) U) C!) Cl) CS) U) Cl) CO U) CO CO Ca CO U) CO (l) () U) (r) c� Ctt (CS RI (0 00 ro CC (0 r0 (0 (0 r0 fd (ti co Cd II) (0 r0 (0 (0 (0 (ij (d Cd (0 (0 RCS (d Ca (U (0 (U CO rat CU r0 tJ (0 qS Al (0 (0 (0 r0 (0 (0 c0 (0 ICI (0 (0 (0 (U 04 04 a a 'a a a a a a a a a a a, a a a a a a G Al Al Al a a a a a a a 04 04 a a a Ai a Al a a, a: a a a a a a.C a a a... a a. a s a; O 0 O O CD 0 O 0 O c-i ri C-I r-I r-I c-1 c-I r-i c-I c-i (-f s-1 N N N N N N N N N N N N N Cr) CY) (Y) CY) CO Cr) CO Cr) V' ‘71 cri LC) i ) Lf) (t) cn i ) 1n Cr) N N N CV N N N N N N N N N N CV N N N N N N N N N N N N N N N CV N N N CV N N N N N N N N N N N N N N N N N N N N N N c--( e-I C c) CO N H M N 0 0 t o N 0) H H CO CO tD N 10 0 o r- nZI+ CV CD ( N d+ N C) CO f`- (!) 1.() CO C•N N H e-1 0 0 vc O 431 LOlfl N CO IC) cis N 01 N cr 0 CD CO Q+ (0 c-( C) CO N Cc) (0 (0 r-i 4l CT co co 00 N r-- (r) (e) re) co N N N N N H H c-1 ri 1-1 c-1 r-( H 4 r-C r-1 c-1 01 01 OD CO CO co C`- C- r-- N LC) CO C 0 lc) Li) 10 C.() 10 t ) in ct1 Cc vc c7+ CC (0 (0 (Y) CY1 (0 (Y1 (Y) (0 CY) CO (1) Cc rt+ Ln LC) Ct) l4 Cfl CO r- C- N- co CO CX) 01 01 01 0 0 0 c--I r-i c-I N N N (Y) m Cr) Q' c*+ I.f) Lt) 1n lc) 1/40 lfl r- N N co CO CO CSl 01 01 O 0 O c-I r-I H c-i c--I r( c-( c-1 c-I r-1 —1 r-I rt ri c-I c-I r-I c-1 r-i r-1 c-i .-i ri r-C N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N (Y1 CY1 (0 (Y1 (') CY) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a 0 0 0 0 0 CD 0 CD 0 0 CD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C) 0 0 0 0 0 0 0 0 0 0 0 0 CD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C 0 O 0 0 0 0 0 0 0 0 0 0 0 O D CD 0 0 0 0 0 0 O 0 0 0 0 0 CD 0 C) CO 0 0 ODD 0 0 0 0 0 0 0 0 C 0 0 0 0 0 . 0032 36 2 5 Pass 0 . 0032 36 2 5 Pass 0 . 0032 35 2 5 Pass 0 . 0033 35 2 5 Pass 0 . 0033 34 2 5 Pass 0 . 0033 33 2 6 Pass 0. 0034 33 2 6 Pass 0. 0034 32 0 0 Pass 0. 0035 31 0 0 Pass 0. 0035 31 0 0 Pass 0 . 0035 31 0 0 Pass 0 . 0036 30 0 0 Pass 0 . 0036 30 0 0 Pass 0 . 0036 29 0 0 Pass 0 . 0037 27 0 0 Pass 0, 0037 27 0 0 Pass 0 . 0037 26 0 0 Pass Water Quality MP Flow and Volume for POC 1. On-line facility volume: 0 acre-feet On-line facility target flow: 0 afs. Adjusted for 15 min: 0 ofs. Off-line facility target flow: 0 ofa. Adjusted for. 15 min: 0 cfs. Perind and Impind Changes No changes have been made. This program and accompanying documentation is provided 'as-is ' without warranty of any kind. The 1 entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or, the Washington State Department of Ecology has been advised of the possibility of such damages. DR 1 VE WA YiVtVW1-11Vi VIEWS AND REPORT 14.0.11111.10 I WWHM3 wwhi 4ouse2 _- - -- - --- -- _- - -- -- --- --- Re edit View He:w --len ',,i � ouri{� Mil �� �� �.,.._-'��; .":71 :tom er-zt��sn is...�2r „_....�. r r..._�-'asr.•_ r a _:J4^ "•..r►.;�•r z_ vr.=vsc:tSC rse.•na.-..�:�.t�.n r..r fa-n-..-7 : __ ..-.n- -.....v��...-a..eve....:_._. ........_..�_ 9 -__ • 501 PIIC1 Predevetaped/ ,inn..; '_'r*Vency o 10E1 i.� xxxxxxxxxxxxxxxxxxx�coaeoab<xxxxxxxxxxxxxxxxxx iTt.cgl{C.v.' on:, 0'01 0601 701 In4lowtoPOC1 t��g®td i j • 801 POC 1 Mrhgasedtlow i 12 Ys&r a 0.0008 0.017C 0.0000 - - -- ----• 'i3 Year $ S.0:16 0.0243 0.0000 -13 year m 0.0022 0.0292 C 0000 r. 1123 7lal.. e .ti031 0.0339 0.0000 ti 10zE 7,7 30 Tear. 0.0037 0.0413 C.0000 •�'✓i v ea,_ = 0.0043 0.0471 0 0000 'Ir pYoalliv v V d 2949 0.0029 0 0220 e.Q CO r j 90E-1 i! 10s0 v .001C b CmC-Z e.000d li I; z.. 0.0012 0.0199 0.0000 rasa 1952 0.0009 0.016'1 0.0000 ,,,,,a, aaeaaat Lea `a i! 1333 0.3C04 b.0222 0.0000 10E-2 3aeoadaa.ca 7 1954 .0006 0,0151 0.0000 1 10 20 30 40 60 SO 70 80 90 99 ii -335 3 0007 0.0107 0.0000 1930' 0 .0007 0.010� 0.0000 Cumulative Probabny °° to 13E 0 .00r.2 0.0232 0.0000 _____ ' 1938 0.0005 0.0160 0.0000 _J Water H ro r h Wetiarrd Fluctuation _j ` las9 fl.0015 0-9 Durations Flow Frequency �S+d,9 ..��� . . C,vs.? 0.0000 1960 0.0009 0.0231 0.0000 ellyze datase9s 1 196= 0.0004 0.•0."3a 0.0000 `1 PUYALUJPD'AILV EVWW/JENSEN-HAWSE "'.._-_--.. .._._P 1392 0.0000 C.3207 0.0000 '2BURLINGTON PRECIP I1963 v C a 0 r . 0.0106 0.0000 J 0,0210 F.fi.n. _969 : .v0.2 0.047s 0.0:3 �. 1000 Gravel Trench Bed 1 ALL OUTLETS tvfitigated0 0 1001 Grawet Trench Bed 1 NUTLET 1 Mrhgated ' 1967 0.0008 0,0316 C.Yob:0 6 1002 Gravel Trench Bed 1 DUTLET a Mi13gated -. g 1 195.8 0.0017 0.0270 0.0000 1969 0 .0004 0.010C 0.0000 AB Oatesets I Flora J Stage Prec ip 1Evap 1 POC i I ) 1970 0.0002 0.0343 0.0000 19?1 0.0019 0.0183 0.0000FloydFrequsn ,'Meti�od �� 1372 0.0008 0.0129 0.0000 {9 Log Pearson Type W 17B ;I 1973 0.0004 0.0.33 0.0000 .- Wetbull it • ti;4 Z ^,n.,7 d Al�S9 A as n:f L�annane .f .r. ___ -- -- l_, i !Mr 45 o a 117--- p T I Vitt..?M3 drtvewayz _� _ ___� - --- ite ECit `,Iew -+IP,r LILT! ....i.._ - as I s-w.ai.✓�.o_��.-...`.ia..,.._ _'aw..-..• , aw.+a:.s.'. -. �_.�_::->,a-:...•_.i„n.a-.a.._..�... - _....r.-+,.�._..-ic..r _.r.... ..�........w�.as...... u..._.-.. ...._... - - •.rca..r^.. ia.....�+.....r,.h,�.�.._. _....._ - - -- _ is 631 POC1 Predevstopedi nc.t4 Trecuan y :1_.,2 r ) 03v_ 0801 19 10E 1 = , 801 t}OCi t,4ttgefedflhsar c .1--0{�C_S, �° --' f 2 Year a 0.0003 C.0064 ';3 ?ilia:: a 0.0006 0.0088 !II 4 Year = 0-0008 0.0106 I r� C .r p25 Year : 0.0011 0.0131 b? 10E Q l'50 Yam 20 0.3014 0.015C . 0.13 Year a 0.00.6 0.0171 v Year y Ptak. . 1943 0.0010 00.0080 _. L 1r1E 1 SSD 0.0006 0.0060 fi 1351 0.0004 0.0072 i 1552 0.3c03 t7.0ese i! 1333 0.0001 0,0081 11 1354 . 0.000'2 0.0053 t0E-2 ti N 1985 0.0002 0-0333 I 10 20 30 40 , ,,,.60,: .7s3 :3T` - 90 99 1; 1956 0.0003 0 .0039 , u' C11fe�Pro a 1 ity , 39i" 0.0004 0.0084 _ __ ' P 1338 C.0002 3.0038 Durations Flow Fre uency 1 Water•Quality -I-Hydra graph �Wetland Flat atsfln i4 's 3=3 t3.0006 0.004". 'I 1560 0 0003 0.0084 Analyse daiasexs ; 1341 0 4002 0.0050 _ _ _ 3 _352 o.0000 �.oc7s f't1�'ALLUPElAl1.'i'EVA1;Wi E�JSEN-RAISE .�_...�_._..�. .�• -3y2 0.0000 0.0075 '2 BU11......RUHGTQt`1 PREClP i1 11 �3 64 0 0 00'3 0.0076 13$a C.0005 0.0174 1000 Gravel Trench Bed 1 ALL OUTLETS Mitigated 135e. 0.0001 0, 0049 y 1001 Gravel Trench Bed 1 OUTLETOUTLET1Mrtrigaled .0322 1002t velTrenchBedl()MET 2Mrtgated `368 0'35" 0.0003 0006 0C.0198 1003 Gravel Trench Bed 1 STAGE Mit . gated Ass 1363 0.0001 0.0,039 _S _ 9 .3 VI 1370 0.O001 0.0125 All iaatnseis e PreCiA Blew FOCI _ �r...�.... 1 1371 0.0007 0.0067 Panel Frequency Method it 1.312 0_0003 0.0047 ;LaygPearsunTypet1117B �I -.973 0..0002 0. 3=55 It+ h' Nora 1 0. e p�� _ __ t 1'4 WHM3 drivvway2 lie Eft. View -e}7 rt i .L � i Itr.._ �— I al NIVPI 1 41 a 7-_1 7-7.--- ` ` 23si- 's' r-.«e.:ed SCENARIOS - - .._ -- ' S? b asin Name: IBasm Desagnes Bypass forPt7C ``" "• ' _ ';,o,��,f, Surface lrr rllow Groundwater mitigated _ — - — ---, ; �._ _ _-- --- - -- --_ kj Area in Basin I✓ dhow Only Seiscted Run soenanc i Available Pervious Available Impervious _s yei a Oi?rsst Rat -_. - — ;a R OF Tt3PS FLAT FI F#�IFlyT - - �� F. 54i31V KAYSffiI.i:f 02B_ - Wiiiteasig g III '-'-';; :: _ la r. 1- . _ _ _.. .-1 HEiliiii!JI _ _ . El :nent.z: ACi` PerviousTota 0 ' Acres Impervious Total 10.02E I Awes L r . Basin Total �fl 02B �_ �-j Acres t : --L4 v Lc a x.±- 4 t►i .. _ . ___J Deselect Zero Select By" GO . TIljr 11 0 5• - - - ill p 31 I WWN.-! 33 d e►.ay2 'le Eclt View Help. I to ® )0 . . bill . I 411111071 41111 .■* k.fl i . . . . ' •-Basin I Mitigated SCENARIOS al_ g Subbasin Name: [Basin S . r Desrgneite as Bypass for ROC_ r Predevelopect Surface lertertlow Groundwater Flows To _ !____T RIP ;; i Area in Basin Ri ShowOrtl► elec je t Run scenario j __ Available Pervious Available_ Impervious wi Ft FMFNTS o G FrsatFfei --- - "fl ROOFTOPS FLAT R' ORWEWAVS FIAT_ ` !028 jo : aiiiiii ,-,..,.. ,.e ,--a--,z " 1, 1 1. f i; it h i Move Elements 411PerviousTota 5 —I Acres Impervious Total 0.026 Acres V' i yol BasinToiel 10028_ .Y_jAtres savexy1 Load xy; `a ._? '( ,40 I • Y 2�_ Deselect Zero Select By: 00 Western Washington Hydrology Model PROJECT REPORT Project Name: driveway2 Site Address : City Report Date : 9/28/2017 Gage Burlington Data Start : 1948/10/01 Data End 1999/09/30 Precip Scale : 0 . 83 WINO Version: PREDEVELOPED LAND USE Wime : Driveway ypass : No GroundWatey_ No Pervious Land Use Acres Co Forest, Flat . 028 Impervious Land Use Acres Element Flows To: Surface Interfiow Groundwater Name Basin 1 Bypass : No GroundWater: No Pervious Land Use Acres InTervious Land Use Acres DRIVEWAYS FLAT 0 . 028 Element Flows To: Surface Interf low Groundwater MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flowscfs) 2 year 0. 000279 5 year 0. 000584 10 year 0.000815 25 year 0.001122 50 year 0.001353 100 year 0.00158 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(ofs) 2 year 0. 006393 5 year 0.008842 10 year 0. 010627 25 year 0.013072 50 year 0.015036 100 year 0. 017125 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.001 0. 008 1951 0.001 0.006 1952 0.000 0.007 1953 0.000 0.007 1954 0.000 0. 008 1955 0.000 0.006 1956 0.000 0.004 1957 0.000 0.004 1958 0.000 0.008 1959 0.000 0.006 1960 0.001 0.004 1961 0.000 0.008 1962 0.000 0.005 1963 0.000 0.008 1964 0.000 0.004 1965 0.000 0.008 1966 0.000 0.017 1967 0. 000 0.005 1968 0.000 0.012 1969 0. 001 0.010 1970 0.000 0.004 1971 0.000 0.012 1972 0. 001 0 .007 1973 0. 000 0.005 1974 0.000 0.006 1975 0.001 0.006 1976 0. 002 1977 0. 000 0.009 1978 0. 000 0.005 1979 0.000 0. 010 1980 0.000 0.005 1981 0.000 0.007 1982 0.000 0.005 1983 0.001 0.006 1984 0.000 0.005 1985 0.001 0.007 1986 0.000 0.007 1987 0.000 0.005 1988 0.000 0.004 1989 0,001 0.011 1990 0.000 0.006 1991 0.000 0.007 1992 0.001 0.010 1993 0.000 0.006 1994 0. 000 0.004 1995 0.000 0.005 1996 0.000 0.005 1997 0.000 0.008 1998 0.001 0.014 1999 0.000 0. 007 2000 0.000 0.004 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0024 0. 0174 2 0.0011 0. 0144 3 0.0010 0.0125 4 0.0009 0. 0122 i 5 0.0007 0.0116 6 0.0007 0. 0108 7 0,0007 0.0103 8 0.0006 0.0102 9 0.0006 0.0098 10 0.0006 0.0088 11 0.0006 0.0084 12 0.0006 0.0084 13 0.0005 0.0081 14 0,0005 0.0080 15 0.0004 0.0077 16 0.0004 0.0076 17 0.0004 0.0075 18 0.0003 0.0072 19 0.0003 0.0072 20 0.0003 0.0072 21 0.0003 0.0070 22 0.0003 0.0069 23 0.0003 0.0067 24 0.0003 0.0067 25 0.0003 0.0066 26 0.0003 0.0064 27 0.0003 0.0062 28 0.0003 0.0061 29 0.0003 0.0060 30 0.0002 0.0058 31 0.0002 0.0056 32 0.0002 0.0055 33 0.0002 0.0055 34 0.0002 0.0055 35 0.0002 0.0054 36 0.0002 0. 0053 37 0.0002 0.0052 38 0.0002 0.0052 39 0.0002 0.0050 40 0.0002 0.0049 41 0.0001 0.0047 42 0.0001 0.0047 43 0.0001 0.0046 44 0.0001 0.0044 45 0.0001 0.0041 46 0.0001 0.0040 47 0.0001 0.0039 48 0.0001 0.0039 49 0.0000 0.0039 50 0.0000 0.0039 51 0.0000 0.0038 POC #1 Facility duration standard for 1+ flows. Flow(CFS) Predev Dev Percentage Pass/Fail 0.0001 4538 36765 810 0.0002 3991 35393 886 0.0002 3462 34154 986 0.0002 3061 33225 1085 0.0002 2733 32281 1181 0.0002 2468 31334 1269 0.0002 2212 30350 1372 0.0002 2005 29487 1470 0.0002 1821 28647 1573 0.0002 1654 27838 1683 0.0003 1490 27078 1817 0.0003 1365 26465 1938 0.0003 1243 25884 2082 0.0003 1118 25379 2270 0.0003 1025 24780 2417 0.0003 930 24234 2605 0.0003 857 23702 2765 0.0003 798 23211 2908 0.0004 744 22710 3052 0.0004 696 22223 3192 0.0004 646 21780 3371 0.0004 602 21311 3540 0.0004 554 20788 3752 0.0004 510 20332 3986 0.0004 475 19925 4194 0.0004 439 19473 4435 0.0005 401 18959 4727 0.0005 371 18584 5009 0.0005 346 18280 5283 0.0005 325 17918 5513 0.0005 307 17569 5722 0.0005 291 17265 5932 0.0005 273 16903 6191 0.0005 247 16568 6707 0.0006 220 16255 7388 •--• ,--I . 1 r--1 r--1 r-1 —i r—. — -•"t r-I — -•-1 r-1 r'-' 1^1 —1 ^ ---i rs —1 r-1 r•t .-1 . --' r—n — .-'i r—i —a r, r-t r—r :--I r-t —t .--r —1 _ .—. • -•- •,...I •-•- .r..j `r-t •^-1 •^i --'1 '� -rti -'"'r -r-i -,� -r+ •r{ .r -rl -"1 -r'i •r1 •r1 -.•- -.-� .h 'rr •r: •ri -ri •r1 -rr -,--: ••--t r•t �I ..-j -rt .-, 'ti r^. •ll M CO t tG t0 U 'L` `0 (15 CG tO v '0 O C3 CJ ' TS M r0 :3 t- 'L1 to o cd r' to co to CO 72 ij 'a t0 (L` ra cc to rt to rr) r cr cCO +-'l G it c% rJ to C11 - - 4 ss Cz � se _ Cw i_ t.1.4 i:. 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CD O 0 0 CD CD 0 0 0 C) 0 0 0 0 c 0 CD O CD 0 O O CD CO O CO CQ 0 O C) 0 0 0 CD 0 0 0 0 0 0 0 0 0 0 0 0 0 CO O 0 CD CD 0 0 0 CD 0 CD O O 0 O C) 0 0 CO C? C) 0 C) O CD 0 0 OO 0 0 a 0 0 0 • ♦ ♦ 0 0 0 0 0 0 0 ♦ 0 0 0 0 ♦ ♦ 0 0 0 0 • 0 • 0 • 0 • 0 _ • • 000 O O CI 0 0 0 C ) C) 0 CD 0 0 0 0 0 0 0 0 CD 0 O CD 0 CD CD O 0 CD 0 O 0 O O O O C O CD O O 0 O O C) O O CT 00 0000 0 0013 31 6317 20377 0 . 0013 31 6227 20087 0 . 0013 30 6156 20520 0 . 0013 30 6084 20280 0 . 0013 29 6013 20734 0 . 0013 27 5937 21988 0 . 0013 27 5874 21755 0 . 0014 26 5816 22369 The development has an increase in flow durations from 1/2 predeve1od 2 year flow to the 2 year flow o7c more than a 10% increase from the 2 year to the 50 year flow. Water Quality BM Flow and volume for POC 1. On-Line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for Th min: 0 ofs. Off-:line facility target flow: 0 tufa. Adjusted fox 15 min: 0 cfs. PeO,nd auld Impind Changes No changes have been made . This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages SIDEWALK-WGVHM VIEWS AND REPORT P;lProjects1170201DOCSVDrainage Memo 10.19.17.doc 9 1 VVWHM3 Sdewelk 'i1e Ed?..• ':e've Help 1- i ilk ... L111 7 4 1411C 111111141111:7 . bib._' I 1474.‘ kw it" .,, DFIvetray Pt-edeve1oped SCENARIOS If .. , ri,-- 11 — Subbasin Name. Dnveway - P II 1-.:1 - -- _____ ,.., Surface Interflow Groundwater —4 1 Flows To , L.... k i Mrtigated i iJ Area in Basin fj Show Only Selected Run Scenano I 1 I I Available Pervious Available Impervious ...__ I i.-0 Forest -Kel Illi p iiiobtor3-d.0.1.Af-. - -I :6-- -- - - F! FMFNTc S 1.,i _. ... _ . . 111111111 I F... DRIVEWAYS FLAT . ilgm' 121Z4r :11'7' 11 .__ 1.73 , •••' lama 11 4 1 - - - • .., pi 1* Ili =.1111111111 NM ItiVat ,,, C.:ri 1,1.1M I I I 1 I 1 1 I . 1 i Move Elements tli ' f* PeryiausTota FriFIT 7 Acres Impervious Total lb- _i Acres 411 t 1110 , Basin Total 011 Acres Save xy i Load xy! 1 ...-:-.:.:-.......-"--...!......--....-_-:-.t....:=._ _ _ [ilff - - - Y :12 Deselect Zero Select ate' GO -- , _. ift or dm ‘ III _ _ Inc • Ravnik & Associates, L. N CIVIL ENGINEERING & LAND-USE PLANNI ,c0wAsit:4: 2 201 l STORM DRAINAGE MEMO y OCT 7 for LIU 2202 15TH Street CITY OF ANACORTES (BLD-2017-0349) LANDED GENTRY HOMES RESIDENTIAL DEVELOPME Revised: October 26, 2017 September 'fn 4017 The residential development proposed herein located at 2202 15th Street in Anacortes, Washington is generally proposed to include construction of a new house and driveway which will create an increase in the stormwater runoff from the site. The new roof area (3,376 sf), driveway (1,190 sf), and new sidewalk (470 sf) for a total of 5,036 sf of new impervious surfaces on a 10,475 square foot lot where an existing building, gravel and lawn areas currently exist. Stormwater runoff from the proposed 3,376 sf house roof area will be collected by downspouts and conveyed via a tight-lined system to a proposed infiltration trench to be installed within the northerly area of the lot. The driveway will be cross-sloped downhill to the west to promote dispersion and infiltration of runoff waters onto adjoining lawn areas which area large enough to infiltrate up to the 100-year storm as noted further on within this report. The sidewalk with collect runoff via a new gutter and convey it east, then north along the west side of "D" Avenue where it will enter an existing catch basin, as generally occurs today. Additional small areas of impervious surfaces, such as walkways, etc will be graded to disperse runoff via sheet flow onto adjoining areas of lawn/landscaping. Initially the DOE Flow Chart 1-2.4.1 Flow Chart for Determining Requirements for New Development has been used to determine that all minimum requirements apply to the new and replaced hard surfaces and converted vegetation areas. Most notably are Minimum Requirements #5-Onsite Stormwater Control, #6-Runoff Treatment, & #7-Flow Control. This project proposes to infiltrate runoff generated from a majority of the new and replaced hard surfaces as noted within the following sections of this report. Since the design within this report notes impervious surfaces (with the exception of the sidewalk) will be infiltrated as confirmed by use of a continuous model software(WWHM) they are considered "ineffective impervious surfaces", and thereby is Flow Control exempt per DOE Volume I Section I-2.5.7. As required by the 2014 Department of Ecology Stormwater Manual, the Western Washington Hydrology Model (WWHM), a continuous model software,has been used to calculate pre-developed runoff conditions, post-developed runoff conditions, and the combined performance of storage volume and infiltration discharge. As further described herein, a underground detention/infiltration facility will be used to infiltrate the runoff from the new house. When sizing infiltration trenches using WWHM software, a theoretical riser outlet structure is purposely included within the analysis. If water is P:IProjects1170201DOCS1Drainage Memo 10.26.17.doc 1 1633 LINDAMOOD LANE / P.O. Box 361 . BURLINGTON, WA 98233 PH; (360)707-2048 • FAX: (360) 707-2216 found to be released through the riser structure, the volume of rainfall upon the developed site will be considered to have exceeded the system's infiltration and detention capacities, thereby identifying a failure in design. A properly designed and most efficient drainage system will use the infiltration and detention facilities to their maximum capacities without noting any water released through the theoretical riser used in the model. WWHM also be used to estimate 100-year runoff rates generated from the new driveway area in order to determine how much area will be needed to infiltrate 100% of these waters. Using WWI-IM three models were created to demonstrate the performance of the (1) Infiltration trench to infiltrate roof runoff, (2) Determine the necessary area required to infiltrate runoff from the proposed driveway area, and (3) Determine the runoff rates generated from the 470 sf of new sidewalk proposed along the project frontage. House Basin: Using an infiltration rate of 6.33 inches per hour as allowed within the attached geotechnical report prepared by Geotest for this project, it has been determined that it will take 46 if of 2-foot wide x 2-feet deep infiltration trench having a bottom elevation set at 3-feet below surface is necessary to infiltrate 100% of the post-developed runoff waters generated from the new 3,376 sf(0.77-ac) house roof area. As noted within the WWHM view information provided with this memo for the House it is noted that 0 cfs is released via the riser used in the modeling, indicating 100% infiltration has been achieved using the proposed trench. Refer to WWMH view and Report for the House attached with this memo for more detailed analysis information. Proposed Infiltration Trench(tight-lined to downspouts): 46'long x 2' deep x 2' deep Drainrock filled trench(bottom @ 3-feet below ex. grade) Void Ratio: 0.33 Infiltration: 6.33 in/hr(per the geotechnical report prepared by Geotest dated 08/30/17) Since the approved runoff model methods note that the entire runoff file is infiltrated up though the 100-year storm, the house is considered to be "ineffective" per (per the definition of"Effective Impervious Surface"(DOE Manual Volume I-Appendix G). The attached Memo prepared by Geotest Engineers notes that the proposed infiltration trench is extremely unlikely to negatively impact any surrounding foundations at its proposed location 11-feet from the north property line. Driveway Basin: As an alternative way to look at the driveway dispersion/infiltration provided, the use of WWHM allows us to calculate the 100-year flow frequency runoff that will be generated from the 1,190 sf(0.028 acre) of driveway area to be dispersed. Based on this analysis the 100-year storm event runoff values increase from 0.0016 cfs during the predeveloped (forest) condition up to 0.0171 cfs for the post developed (concrete) condition. This 0.0155 cfs increase in runoff that is anticipated from the conversion of 0.028 acres from forested condition to concrete driveway can easily be infiltrated onto the undeveloped P:\Projectsk170201DOCSWrainuge Memo 10.26.17.doc 2 landscape area located to the west of the proposed driveway. Using a 1.50 in/hr infiltration rate from the attached geotechnical report prepared by Geotest, it only will take approximately 493 sf of area to infiltrate the 100-year storm even in an area where there is over 1,200 sf of area available. Refer to the following equations: Infiltration Rate Use 1.50 inch/hour = 0.0250 inch/min = 0.0000347 fps Required Infiltration Area for 0.028 ac driveway for 100-year storm 0.0171 cfs/0.0000347 fps = 493 square feet of area required to infiltrate the runoff from the developed 100-year storm event for the entire driveway area. Since the length of driveway is approximately 40 feet, it is estimated that it will take approximately 12.31 feet of width of vegetation and/or undisturbed soil along the west side of the driveway to infiltrate runoff from the 100-year storm. Based on the driveway length of 40 feet, fun infiltration will be achieved in 12.31 feet. As with the roof runoff, since WWHM analysis (an approved continuous runoff modeling method) indicates that entire runoff file is infiltrated up though the 100-year storm, the house is considered to be "ineffective" per (per the definition of"Effective Impervious Surface". Sidewalk Basin: To estimate the 100-year flow frequency runoff that will be generated from the 470 sf (0.011 acre) of new sidewalk area WWHM will be used. Based on this analysis the 100- year storm event runoff values increase from 0.0006 cfs during the predeveloped (forest) condition up to 0.0067 cfs for the post developed (concrete) condition. Therefore there is only a 0.0061 cfs increase in runoff anticipated from the conversion of 0.011 acres from forested condition to concrete sidewalk. This area is considered Non-Pollution Generating Impervious surface (NPGIS). This surface is classified as "effective impervious surface" per the DOE manual. This new sidewalk area will be sloped to direct flows to the adjoining gutter which will convey waters easterly, then northerly to the existing catch basin structure located near the subject properties northeast corner. This small increase in "effective impervious surface" generated with this project will not have a significant impact on the existing drainage system and is noted as exempt from Runoff Control as noted within the summery section of this report. Summary For the proposed roof area, based on the areas previously noted, tight-lining roof downspouts to a 46-foot long x 2-foot-wide x 2-feet-deep drainrock filled infiltration trench and dispersing driveway runoff onto areas with vegetated flow path length greater than 12.31-feet is sufficient to mitigate the increase in stormwater runoff that will be P.IProjects1170201DOCS1Drainage Memo 10,26.17.doc 3 created by the construction of this new house. Both of these new impervious surfaces are considered ineffective per DOE definition of"Effective Impervious Surface" within the DOE Manual (Volume I-Appendix G). The new sidewalk along the existing roadway comprised of 470 sf of new concrete will be the only "effective" impervious surface proposed with this project. As previously determined using the WWHM analysis, the new roof area will be infiltrated and the new driveway area that will be dispersed and infiltrated makes these two impervious surfaces classified as "ineffective"per the DOE manual, leaving only the new roadside sidewalk. Accounting for the new roof area, driveway, and new roadside sidewalk, only increases the 100-year flow frequency runoff flows from 0.0065 cfs (0.0043 cfs + 0.0016 cfs + 0.0006 cfs) for the pre-developed to 0.0709 cfs (0.0471 cfs + 0.0171 cfs + 0.0067 cfs) during the post-developed condition. This shows there is only a 0.0644 cfs net increase in runoff during the 100-year flow frequency as estimated using the WWHM model, which is less than 0.10 cfs threshold, making this project exempt from DOE Requirement #7-Flow Control as noted in the following paragraph even when conservatively accounting for the ineffective impervious surfaces. Per DOE section 2.5.7-Minimum requirement #7-Flow Control a project is exempt from providing flow control is the project if: 1)The project has less than 10,000 square feet of effective impervious surfaces, 2) The project converts less than 3/4 acre of vegetation to lawn for landscape (or converts less than 2.5 acres of native vegetation to pasture), and 3) Through a combination of effective hard surface and converted vegetation areas cause less than a 0.10 cubic feet per second increase in the 100-year flow frequency as estimated using the WWHM model. The analysis determining the difference in flow was conservatively performed using the forested land cover for the predeveloped condition as per the footnote in DOE Manual Volume I-Chapter 2 (page 65) states that the 0.10 cfs increase should be a comparison of the post project runoff to the existing conditions runoff based on the pre-project land cover, or the land cover that existing at the site as of a date when the local jurisdiction first adopted flow control requirements into code. Since this project has shown that proposed roof area is infiltrated and the driveway area has sufficient area to the west to infiltrate driveway runoff, based on the WWHM flow frequency values, means that these areas are technically not an "effective impervious area" (per the defmition of "Effective Impervious Surface" (DOE Manual Volume I- Appendix G). Therefore this results in the project only having 470 sf of "effective impervious surface" which is less than a total of 10,000 square foot threshold of the "effective impervious surfaces". In addition the runoff increases less than 0.10 cfs during the 100-year flow frequency based on the WWHM model, therefore this project is exempt from providing Runoff Control as noted. Furthermore, since this is determined to P:IProjects1170201DOCS1Drainage Memo 10.26.17.doc 4 be Flow Control exempt in accordance with DOE Manual section 2.5.7 as noted above, this project is not required to meet LID performance or standards as noted in section 2.5.5-Minimum Requirement #5-On-site Stormwater Management other than what is noted below. DOE MINIMUM REQUIREMENTS Based on the thresholds noted within the 2014 Department of Ecology Manual's Flow Chart for Determining Requirements (Figure 2.2) attached, the proposed single-family residential development requires the project to meet Minimum Requirements #1-9, however since the engineering analysis using an approved continuous model software shows that use of the infiltration trench will infiltrate the roof runoff, and it has calculated that there is sufficient area to the west of the new driveway to disperse and infiltrate runoff onto adjoining vegetated areas to remain, this project is not required to provide runoff controls, and subsequently only minimal Onsite Stormwater Management requirements as noted below. The following are the DOE Minimum Requirements #1-9 and how they are addressed: Minimum Requirement#1-Preparation of a Stormwater Site Plan The owner will provide a stormwater site plan which addresses development principles noted within this report. Minimum Requirement#2-Construction Stormwater Pollution Prevention (SWPP) Prior to commencing any construction the project's contractor must prepare a Construction Stormwater Pollution Prevention Control Plan that identifies the measures they will address each of the 13 Construction SWPPP Elements as necessary to prevent the erosion and discharge of sediment and other pollutants from the site. Minimum Requirement#3-Source Control of Pollution No source control BMP's are anticipated with this residential project. Minimum Requirement#4-Preservation of Natural Drainage Systems and Outfalls This project proposes to infiltrate runoff waters other than the small amount of runoff from the new sidewalk which will be conveyed to the existing drainage systems that currently receive runoff from the area. Minimum Requirement#5-On-Site Stormwater Management This item requires the employment of On-site stormwater management BMP's to encourage infiltration and dispersion of developed stormwater runoff. This project is not required to provide Runoff Control as denoted within this report,therefore it is also not required to provide LID Performance requirements, or follow List#1 or#2, however the project is required to implement BMP T5.13; BMP's T5.10 A, B, or C; and BMP's T5.11 and T5.12 as feasible. Infiltration has also been incorporated into the design for the both the roof and driveway runoff. P:IProjecisl170201DOCSWDrainage Memo 10.26.17.doc 5 Minimum Requirement#6-Runoff Treatment Runoff treatment is required for all Pollution Generating Pervious and Impervious surfaces (PGPS and PGIS). The only pollution generating surface proposed it the driveway areas for this project, as roof runoff is considered non-pollution generating. The proposed driveway surface is to be constructed with a cross slope to direct runoff waters to disperse onto adjoining vegetated areas where there is sufficient width of vegetation to provide the 91'percentile storm runoff sufficient contact time to provide water quality before being discharged from the site. #7—Flow Control As previously noted per DOE section 2.5.7-Minimum requirement #7-Flow Control, a project is exempt from providing flow control if the project is: 1) The project has less than 10,000 square feet of effective impervious surfaces, 2) The project converts less than 3/4 acre of vegetation to lawn for landscape (or converts less than 2.5 acres of native vegetation to pasture), and 3) Through a combination of effective hard surface and converted vegetation areas cause less than a 0.10 cubic feet per second increase in the 100-year flow frequency as estimated using the WWHM model. Since this project has shown that both the roof and driveway have sufficient area infiltrate, based on the WWHM software analysis which makes these areas classified as "ineffective impervious area" (per the definition of"Effective Impervious Surface" (DOE Manual Volume I-Appendix G). Therefore this results in the project having less than a total of 10,000 square feet of "effective impervious surfaces". In addition the runoff increases less than 0.10 cfs during the 100-year flow frequency based on the WWHM model therefore this project is exempt from providing runoff control as noted. #8 - Wetlands Protection There is no discharge proposed from this site to any wetland. #9—Operations and Maintenance Not applicable to this project. P:1Projects1170201DOCSDrainage Memo 10.26.17.doc 6 STORMWATER EXHIBIT FIGURE I-2.4.1-FLOW CHART FOR DETEMINING RQMNTS FOR NEW DEVELOPMENT DOE DEFINITION OF EFFECTIVE IMPERVIOUS SURFACE INFILTRATION TRENCH DETAIL P.IProjects1170201DOCSIDrainage Memo 10.26.17.doc 8 AP l OXIMATE LOCAT101N OF 46' LONG x 2' MD X 2' DEEP DRIANROCK I-ILLLU IKLNUN Ih' NUN 1-UK KUUF UNAINS, PER INFILTRATION TRENCH DETAIL i z. ss SS ss 55 ss EXlsO L0 QVC.ss 55 —mow ss s— SS CI CC; I War 5S C III Nei a 0 1 t 46.00' 110.00' ,- 11 M 70.00' II a a 1 11 4; , ° 1 1 I ROOF UNE ° 1* I 1 1 co rn ° PROPOSED @� oo ° LEI HOUSE ROOF 3 376 ESF)A I I I Z 1 III��� 1 I la - 1 liJ p' I — - c 1 1 — -e A 3 •2®0' •, e --- 10.67' --1 S.00' e o e :O, 20.00' $LOPE 1 X'61IN . 1 U n . e R,e Q 7 a ____1 ,. , , a,SLOPE 1%we!, 104.92' a ---.._ s \ 1 ;20.00' _'. 4 -I PROPOSED NEW SIDEWALK (470I SF) \ - • 6 — M a 15TH STREET Y a z - _ _ - - - - _��-__PR-V_- 6.0 _ . -6 Y Y M Y - __-Y Y # Y ----r---- as as OS \ Y Ravnik & Associates, Inc. ° `'n°" H.T.S. CIVIL ENGINEERING do LAND-USE PLANNING STORMWATER DRAM BY: HUI 1633 L 1141Fi GOOD I.AN6/ a HOII 361 HURLIN0411 FAX: )70 EXHIBIT PH:{364)7d1,204s FAR:(360)707.2216 JOB N4. 17020 DATE: 09.28.17 1 Figure 1-2.4.1 Flow Chart for Determining Requirements for New Development Start Here 1 Does the site have 35% Yes See Redevelopment Minimum or more of existing ► Requirements and Flow Chart impervious coverage? (Figure 1-2.4.2). No Does the project convert 3/4 v acres or more of vegetation to Does the project result in lawn or landscaped areas, or 5,000 square feet, or 114 0 convert 2.5 acres or more of greater, of new plus -* native vegetation to pasture? replaced hard surface area? Yes Does the project result in 2,000 ---n- V -- square feet, or greater, of new plus An Minimum inium Requirements replaced hard surface area? apply to the new and replaced hard SUM laces and converted vegetation areas. Yes ra`i Does the project have land Minimum Requirements #1 disturbing activities of 7,000 41 through #5 apply to the new Yet square feet or greater? and replaced hard surfaces anti the land disturbed. Minimum Requirement#2 applies. NM a I I EL i t I Figure 1-2.4. 1 —11.1. 111 How el-mrt for Determining Requirements for Viiill New Development DEPARTMENT OF Revised June 2015 ECOLOGY Please see http://www.ecy.wa.gov/copyright.h(ml for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume I - Chapter 2 - Page 37 Drop structure A structure for dropping water to a lower level and dissipating its surplus energy; a fall. A drop may be vertical or inclined. Dry weather flow The combination of ground water seepage and allowed non-stormwater flows found in storm sewers during dry weather.Also that flow in streams during the dry season. - E - EIS See Environmental Impact Statement. ESC Erosion and Sediment Control (Plan). Earth material Any rock, natural soil or fill and/or any combination thereof. Earth material shall not be considered topsoil used for landscape purposes. Topsoil used for landscaped purposes shall comply with ASTM D5268 specifications. Engineered soil/landscape systems are also defined independently. Easement The legal right to use a parcel of land for a particular purpose. It does not include fee ownership, but may restrict the owners use of the land. Effective Impervious Surface Those impervious surfaces that are connected via sheet flow or discrete con- veyance to a drainage system. Impervious surfaces are considered ineffective it 1) the runoff is dispersed through at least one hundred feet of native vegetation in accordance with BMP T5.30: Full Dispersion (p.939); 2) residential roof runoff is infilt- rated in accordance with BMP T5.10A: Downspout Full Infiltration (p.905); or 3) approved continuous runoff modeling methods indicate that the entire runoff file is infiltrated. Embankment A structure of earth, gravel, or similar material raised to form a pond bank or found- ation fora road. Emergent plants Aquatic plants that are rooted in the sediment but whose leaves are at or above the water surface. These wetland plants often have high habitat value for wildlife and waterfowl, and can aid in pollutant uptake. 2014 Stormwater Management Manual for Western Washington Volume I-Appendix G-Page 157 4"DIA. RIGID PERFORATED PIPE FILTER FABRIC 2' 1' FINISHED GRADE TOP II1J ttl *, �' 'lll, SOIL � a WASHED ROCK I H 1=L e 1;111- TRENCH DEPTH o, " o JJ,I III=11 BOTTOM 1 1/2"TO 3/4" INFILTRATION TRENCH SECTION A-A WASHED DRAINROCK Ravnik & Associates, Inc. SHEET DESCASTOSS MALE H.T.S. CIVIL ENGINEERING&LAND-USE PLANNING INFILTRATION °'°A" " " WS LINDA/100IAN6?a BOX NS M 7. TRENCH EXHIBIT " 17— "AM 01E2117 SOILS INFORMATION STORMWATER INFILTRATION EVALUATION MEMO P:1Projects\170201DOCStDrainageMemo 10.26.17.doe 7 741 Meme Olive Bellingham,WA 86225 360 733_7316 !`,_1 �r . „ -- 7061 A 67"Avenue NNC.Arlintan,WA 98723 888251 5276 g 360 733_7418 5)�{ ,, J�� August 30, 2017 Job No. 17 0425 Landed Gentry Horom mid Communities 504 East Fairhaven Avenue Burlington, WA 98233 Attn.: Steven Baughn Re: Stormwater Infiltration Evaluation Padilla Adu Development 2202 15th Street Anacortes, Washington Dear l/1r, Baugn, As requested, GeoTest Services, Inc. (GTS) is pleased to submit this report summarizing the results of our stormwater infiltration evaluation associated with the proposed single family residence at the subject property in Anacortes, Washington, as shown on the Vicinity Map(Figure 1). The purpose of this evaluation was to assess the existing subsurface conditions for use in designing stormwater infiltration system(s) associated with proposed development. This report summarizes our conclusions and recommendations regarding the potential for onsite stormwater infiltration. Specifically, our services included the following: 1. Evaluation of 3 test pits equally distributed across the subject property. Test pits explorations were advanced to7.5 feet below the ground surface(BGS). 2. Geological review of the information collected during this phase of the investigation in order to provide recommendations for the project. Our findings and recommendations are summarized in this site-specific report and contain the following information: • A site plan showing pertinent existing site features and the approximate location of the explorations accomplished for this project. • Logs of our explorations and results of our laboratory testing including a chart illustrating the soil classification criteria and the terminology and symbols used on the exploration logs. • Laboratory determinations of soil classification, including the long- term infiltration rates of soil encountered. Infiltration rates are based on USDA soil gradation analysis, in general accordance with the 2012 Stormwater Management Manual for Western Washington (SMMWW) amended December 2014. Laboratory evaluation on collected soils included USDA sieve analyses and moisture contents. Page lI of 7 GeoMot Services,Inc. August 30, 2017 2202 15th Street,Anacortes,WA Job No. 17-0425 , A summary of surface and subsurface soil and groundwater conditions observed at the site during our field exploration. The summary includes descriptions of subsurface profiles and the potential seasonal effects of groundwater. The scope of services for this report included stormwater infiltration only, it does not include geotechnical recommendations with regards to the planned building foundation support, settlement, potential seismic considerations such as liquefaction and/or other geologic hazards that may exist within this property. PROJECT DESCRIPTION We understand that there are plans to develop the subject property with a single-family residence with associated stormwater facilities and utilities. As part of the development, the stormwater facilities will be constructed to accommodate onsite storrnwater runoff from proposed impervious surfaces. The attached site and exploration map should be considered preliminary. SITE CONDITIONS This section discusses the general surface and subsurface conditions observed at the project site at the time of our field investigation. Interpretations of the site conditions are based on the results of our review of available information, site reconnaissance, subsurface explorations, laboratory testing, and our experience in the project vicinity. Surface Conditions At the time of our visit, the subject property was bordered by single family residences along its western and northern extent and D Avenue and 15th Street to its east and south, respectively. The property contained a 2 bay out building near its southwest corner and was covered in a grass lawn. In general, the property sloped slightly downwards towards the north, with elevation changes being less than about 5 vertical feet. Site Geollogy Geologic information for the project site was obtained from the 'Washington Interactive Geologic Map," published by the Washington State Department of Natural Resouces (DNR). According to this map, deposits at the project consist of Fraser-Age continental glacial till (Ogt). The till is a non-sorted and unstratified mixture of clay, sand pebbles, cobbles, and boulders (diamicton), deposited by glacial ice. The soils encountered in our subsurface explorations are generally consistent with the published geological information and our experience with projects in the nearby vicinity. Page 2 ot 7 GeoTest Services, Inc. August 30,2017 2202 1511'Street,Anacortes,WA Job No. 17-0425 Subsurface Soil Conditions Subsurface conditions were explored by excavating 3 test pits (TP-1 through TP-3) on June 27, 2017. Approximate locations of these explorations have been plotted on the Site and Exploration Plan, Figure 2. The test pits were advanced with a tracked excavator to depths of 7.5 feet BGS. After test pit explorations were completed, the pits were backfilled with the excavated soils and compacted with the bucket of the excavator. In general, subsurface soils encountered within the area of proposed development consisted of approximately 0.5 to 1 foot of topsoil (soft, brown, moist, organic silt) that overlays 2 to 4 feet of weathered glacial till loose to medium dense, brown, moist, silty sand to slightly silty sand) with very stiff to hard, sandy silt with pebbles and cobbles (glacial till)extending to full depth within all 3 test pit locations. some minor fill soils were located above the weathered till in TP-2 and TP-3. Please refer to the attached exploration logs for more detail (Figures 4 through 5). Groundwater Seepage and Seasonal Groundwater For the purposes of this report, observed groundwater seepage represents either the existing surface of a groundwater table or the surface of perched seepage. The groundwater table is referred to as the atmospheric pressure surface that coincides with the top of the zone of saturation and is the surface that dictates the development design recommendations in this report. Perched seepage is referred to as a saturated zone that develops where a restrictive surface (i.e. dense, fine grained soils or bedrock) limits the vertical, downward migration of near-surface water. The groundwater table or perched seepage surface should be considered when determining methods of earthwork construction but is not used to dictate development design, Groundwater Observations At the time of our visit on June 27, 2017, minor, perched groundwater seepage was observed within the test pits between 4.5 and 6.0 feet BGS. As the region has not, at the time of our site visit, recently experienced precipitation, we interpret the groundwater to be interfiow running along the very dense till soils with elevated fines content, generally encountered onsite at approximately 4.5 to 6.0 feet BGS. During periods of extended and/or heavy rainfall we would anticipate that groundwater would be found perched on the very dense till soils with elevated fines content. Seasonal Groundwater Fluctuation Observations A distinct mottled horizon or "rust line," was not encountered within the test pit explorations. Mottling (reddish-brown, orange, or yellow splotches or mottles) is typically indicative of soils that experience fluctuating moisture conditions, generally due to seasonal wetting and drying. Gleyed soils, indicative of poorly drained and potentially restrictive soils, were encountered within the unweathered, very stiff to hard till. Gleyed soils are typically gray or bluish-gray in color and the result of a reduced (non-oxidative) soil state caused by Page 3 of 7 GeoTest Services, Inc. August 30, 2017 2202 1.5th Street,Anacortes,WA Job No. 17-0425 significant periods of saturation. Gleyed soils are often associated with soils that are restrictive of groundwater flow. Please note that changes to soil color and morphology may take significant periods of time to develop and may not be reliable indicators of groundwater conditions in areas that have experienced significant recent changes in hydrology. Additionally, in areas of fill, sufficient time may not have passed since fill placement for these indicators to develop. Not all hydric soils exhibit mottled and/or gleyed horizons. Their presence or absence alone should not dictate the interpretation of site groundwater conditions. Sources of groundwater table fluctuations As groundwater table levels and/or seepage rates are typically not static, it is anticipated that groundwater conditions will vary depending on local subsurface conditions, season, precipitation, changes in land use both on and off site and other factors. Markedly, we anticipate that groundwater conditions on site are largely influenced by seasonal variations of precipitation. Considerations GTS considers the depth at which groundwater seepage stabilizes and ponds to be the groundwater table. Groundwater seepage will influence stormwater management facilities and should be considered when designing those facilities. The groundwater conditions reported on the test pit logs are for the specific locations and dates indicated, and therefore may not necessarily be indicative of other locations and/or times. Please consider that groundwater table levels are generally higher (at shallower depths)during the wetter months(October through May). Our construction recommendations consider the groundwater conditions encountered at the time of our field investigation, in association with the project design provided at the time of this report. It is the clients and their (his/her) representative's responsibility to inform GTS of variations in groundwater conditions and/or any modifications to project designs so that a review of and revision to report recommendations can be made, if necessary. Unless specifically requested, GTS is not responsible to provide monitoring of groundwater conditions beyond the time of our site investigations. Please keep in mind that groundwater conditions may be different if there is a substantial lapse of time between submission of this report and the start of construction. If this is the situation, GTS recommends we be contacted to evaluate groundwater conditions in order to determine whether our report conclusions and recommendations remain applicable. RESULTS Stormwater Infiltration Potential Test Pit Gradation Results From the explorations excavated in the areas of interest, 13 representative soil samples were selected and mechanically tested for grain size distribution and calculation according to the 2012 Stormwater Management Manual for Western Washington Page 4 of 7 GeoTest Services,Inc. August 30,2017 2202 15th Street,Anacortes,WA Job No.17-0425 (SMMWW) amended December 2014, soil grain size analysis method, Section 3.3.6. A summary of these results are reproduced in Table 1 below. Test Pit Sample DesignGeologic K.,�Uncorrected Rate Gealgn Infiltration Rene ID Depth USCS Unit (Inches/Hour) Per ASTM 0422 Simplified Approach(Inches/Hour) TP-1 1.0 SM Weathered Till 9.30 1.51 TP-1 2.0 SP-SM Weathered Till 38.09 6.17 TP-1 MUM SP-SM Weathered Till 48.08 7.79 TP-2 2.5 SM Weathered Till 9.26 1.50 TP-2 5.0 ML Glacial Till 2.24 0.36 TP-3 2.0 SM Weathered Till 1.90 TP-3 3.5 SP-SM Weathered Till 39.08 6.33 Notes; -Ksat=Initial Saturated Hydraulic Conductivity -Listed Infiltration rates are estimated long teen(design)rates based on the soil grain size analysis method. -Correction Factors Used:CFI=0.70 In the simplified approach (Section 3.3.4) the infiltration rate is derived by applying appropriate correction factors to the measured saturated hydraulic conductivity (K ) from the ASTM 422 grain size analysis. Saturated hydraulic conductivity is a quantitative measure of a saturated soil's ability to transmit water when subjected to a hydraulic gradient. It can be thought of as the ease with which pores of a saturated soil permit water movement. Saturated Hydraulic Conductivity is expressed as follows: Log10(Ksat)=-1.57 +1.90D10+0.015Dr0-0.013D90-2.08fenas Where Dio, De0i and Deo are the grain sizes in mm for which 10 percent, 60 percent, and 90 percent is more fine and ffines is the fraction of the soil (by weight)that passes the U.S. No. 200 sieve. Kam, is measured in cm/sec. With this equation, we can determine the saturated hydraulic conductivity for our representative samples. See example below: Test Pit TP-1 at 1.0 foot BGS: lcat = 0.006562964 cm/sec or approximately 9.30 inches/hour. Applying correction factors for site variability (0.45), test method (0.4) and degree of influent control to prevent siltation and bio-buildup (0.9) gives a corrected long term design rate of 1.51 inches/hour for the example above. Based on the 2012 SMMVVW(amended December 2014)soil grain size analysis method and our applied correction factors, the weathered glacial till soils located below the topsoil contains estimated long term design infiltration rates ranging between 7.79 and 1.50 in/hr Accordingly,we recommend using the lowest result value of 1.50 in/hr for use in design for the weathered glacial till. Page 5 of 7 GeoTest Services, Inc. August 30,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 Stormwater Pollutant Treatment The stormwater facilities on-site may require some form of pollutant pre-treatment or treatment with an amended soil prior to onsite infiltration or offsite discharge. It is our opinion, based on past experience, that the re-use of onsite topsoil and weathered Outwash Soils is often the most sustainable and cost effective method for pollutant treatment purposes. Cation exchange capacities, organic contents, and pH of site subsurface soils were determined to establish their pollutant treatment suitability. Cation Exchange Capacity, Organic Content and pH Testing Three composite samples were collected during our subsurface explorations for pollutant treatment purposes. Cation exchange capacity (CEC), organic content (LOI), and pH tests were performed by Northwest Agricultural Consultants. Laboratory test results are presented in Table 2. Test Pit Sample Cation Exchange Capacity Organic Content pH ID Depth(ft) (meglloo grams) (%) TP-1 1.5 11.8 6.34 5.6 TP-2 5.0 21.5 7.78 5.5 TP-3 3.5 6.1 3.65 6.8 Criteria SSC-6 states that cation exchange capacity must be greater than or equal to 5.0 meq!100 grams and organic content must be a minimum of 1.0 percent for treatment purposes. Based on the results listed in Table 2, the Topsoil and weathered glacial till appear to be suitable for onsite pollutant treatment purposes based on the SSC-6 of the 2012 Washington State Department of Ecology Stormwater Management Manual for Western Washington. Additional considerations to using infiltration as a treatment option include the soil infiltration rate! drawdown time as described in SSC-4 of the 2012 Washington State Department of Ecology Stormwater Management Manual for Western Washington. A maximum drawdown time is applied to some types of infiltration based water quality design facilities. LIMITATIONS The scope of services for this report included stormwater infiltration only, this report is not intended to address other geotechnical concerns with regards to the planned building foundation support, settlement, potential seismic considerations such as liquefaction and/or other geologic hazards that may exist within this property. GeoTest can perform additional geotechnical evaluation and/or analysis, with regards to the above mentioned geotechnical items, upon request. The analyses, conclusions, and recommendations provided in this report are based on conditions encountered at the time of the subsurface exploration performed by GeoTest Services, Inc., information from previous studies and our experience and judgment. Our work has been performed in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing under similar Page 6 of 7 GeoTest Services,Inc. August 30,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 conditions in this area. GeoTest Services has prepared this report for the exclusive use of Landed Gentry Homes and Communities and their design representatives for specific application to the proposed new development located 2202 15th Street in Anacortes, Washington. No warranty, expressed or implied, is made. We must presume the subsurface conditions encountered are representative for the proposed site for the purposes of formulating our recommendations. However, you should be aware that subsurface conditions may vary with time and between exploratory locations, and unanticipated conditions may be encountered. If construction reveals differing conditions or the design is modified, we should be retained to reevaluate our recommendations and provide written confirmation or modification, as needed. We appreciate the opportunity to be of service to you on this project. If any questions should arise regarding this report, please contact the undersigned. Respectfully Submitted, GeoTest Services, Inc. • "; 41:. r*n/r a • 4 „mo••_. 4tiumt(601.pu "- / %s'ed Geo!`O, Timhyiia Tim Chylla, L.E.G. Engineering Geologist Attachments Figure 1 Vicinity Map Figure 2 Site and Exploration Plan Figure 3 Soil Classification System and Key Figures 4-5 Logs of Test Pits Figures 6-7 Grain Size Distribution Northwest Agricultural Results(1 page) ASFE-Report Limitations and Guidelines For Its Use(3 pages) References interactive Geologic Map of Washington State. Online interactive services provided by the Washington State Department of Natural Resources. Washington State Department of Ecology, 2012 (amended December 2014). Stormwater Management Manual for Western Washington. Page 7 of 7 , PROJECT LOCATION r N. i J Jrd .. Ill)a Pith 9. Y 1 ,l n - i.••11•1'4 nr Co SOrale PAO, 17:t Alta:—Drt — k rl 1 T rt +th volunteer Pars? I -" t t� ` 1: r.earl- s ' i ., .ti vi1` b ri - • � OAnecortes' firma 1 •-;- Clanbegy N Ai law!Hr.,:: Lake Park DJ zanl :• r + Airport .�I'" F 0 'I,• ;, t• I 'JAf'I•T L. t) -_rJ t•, /,. SS E ..Z i• Y�Ih�I of K v .vIsI r 6 3$ '�c k t"'I. �'''al m ai a1r -. ANC': '% j. �ti , 1• r 1 to `'' tY• I�.N�n.•t Di I t 'ICa61 y 1 h'P t E k1.t-1 V MAP REFERENCED FROM GOOGLE MAPS Dale; 8-30-17 By: JS Scale: As Shown F rcyjeca GEOTEST SERVICES, INC.741 Marine Drive VICINITY MAP 17-0425 a Bellingham, INA 98225 PADILLA ADU Figure phone: (360) 733-7318 2202 15TM STREET fax: (360)733-7416 ANACORTES, WASHINGTON 1 1 PROJECT LOCATION 11► 4‘lativii3O'. 74) A.-gill. • _...... irin „ - � ' ■: ■ o ro . ., ti�. lir-ii 4 tyy"yg 15th Street MAP REFERENCED FROM G00GLE MAPS {9 TP-#=Approximate Test Pit Location t Dale: 8-30-17 By: JS I Scale: As Shown Project GEOTEST SERVICES, INC. SITE AND EXPLORATION PLAN 17-0425 741 Marine Drive Bellingham,WA 98225 PADILLA ADD Figure phone: (36U)733-7318 2202 15TH STREET fax: (360)733 7418 ANACORTES,WASHINGTON 2 . .... Soil Classification System usCS MAJOR GRAPHIC LETTER TYPICAL EVASIONS SYMBOL SYMBOL DESCRIPTIONS"x2) t GRAVEL AND CLEAN GRAVEL 5 6,d °t3 6- GW Well-graded gravel;gravel/sand mixture(s);little or no fines —r �,m GRAVELLY SOIL (Little or no fines) fl.o.n a 8 o o p o•o GP Poorly graded gravel;gravel/sand mixture(s);little or no fines i .1 O ti e (More than 50%of UJ E.1 coarse fraction retained F GRAVEL WITH FINES t GM Silly gravel;grave/sand/sift mixture(s) on No,4 sieve) (Appreciable amount o< : o fines) • Clayey gravel;gravel/sand/day mixtures} agc"o tail c SAND AND CLEAN SAND SW Wet1 graded sand;gravelly sand;little or no fines e4 -E SANDY SOIL (Little or no tines) oP Poorly graded sand;gravelly sand;tale or no fines 0 m FP (More than 50%of Silty sand;sand/sett mixture(s) coarse fraction passed SAND WITH FINES )• 9 1 SIM through No.4 sieve) (Appreciable amount of .: fines) SC Clayey sand;sand/day mixture(s) Inorganic silt and very fine sand; rock flour;silty or dayey fine a SILT AND CLAY" sand or dayey sift with slight plasticity Inorganic day of low to medium plasticity;gravelly clay;sandy E (Liquid limit less than 60) , / Cla day;silty day;lean day Z o -a7 OL, Organic silt;organic,silty day of low plasticity m SILT ANDCLAYMI=� Inorganic silt; micaceous or diatomaceous fine sand z o E (Liquid limit grater than 60) it Inorganic day of high plasticity;fat clay OH Organic day of medium to high plasticity; organic silt HIGHLY ORGANIC SOIL PT Peat; humus;swamp soil with high organic content GRAPHIC LETTER OTHER MATERIALS SYMBOL SYMBOL TYPICAL DESCRIPTIONS PAVEMENT AC or PC Asphalt concrete pavement or Portland cement pavement ROCK ` URIC Rock(See Rock Classification) -A1'� — WOOD WE) Wood,lumber,wood chips w w w a DEBRIS F>. 0 0 DB Construction debris,garbage n n rt Nnus: 1. Soil descaiptiona are based on the general approach presented In the Standard Practice for Description and identification of Soils(Visual-Manual Procedure), as outlined in ASTM D 2488.Where laboratory index testing has been conducted,sal classifications are based on the Standard Test Method for Classification of Sails for Engineering Purposes,as outlined in ASTM D 2467. I 2. Soil description terminology is based on visual estimates(in the absence of laboratory test data)of the percentages of each soil type and is defined as follows: Primary Constituent: >50%-"GRAVEL,""SAND,""SILT,""CLAY,"etc. Secondary Constituents: >30%and<50%-"very gravely,""very sandy,""very silty,"etc. > 12%and<30%-"gravely,""sandy,'"silty,"etc. Additional Constituents. > 5%and<12%-"slightly gravelly,""slightly sandy,""slightly silty,"etc. < 5%-"trace gravel,""trace sand,""trace sift,"etc., or not noted. Drilling and Sampling Key Field and Lab Test Data SAMPLE NUMBER& INTERVAL SAMPLER TYPE Code Description Code Description Sample Identification Number a 3.26-inch O.D.,2.42-inch I.D.Split Spoon PP=1.0 Pocket Penetrometer,tsf 1 b 2.00-inch O.D., 1.50-inch I.D.Split Spoon TV=0,5 Torvanv,tsf Recovery Depth Interval c Shelby Tube ND= 100 Phatoionization Detector VOC screening,ppm 11 1 le— Sample Depth Intervel d Grab Sample W=10 Moisture Content, % 0 Other-See text if applicable D= 120 Dry Density, poi "- Portion of Sample Retained 1 300-lb Hammer,30-inch Drop -200=60 Material smaller than No. 2D0 sieve,% for Archive or Analysis 2 140-ib Hammer,30-inch Drop GS Grain Size-See separate figure for data 3 Pushed AL Atterberg Limits-See separate figure for data 4 Other-See text if applicable GT Other Geotechnical Testing Groundwater CA Chemical Analysis a Approximate water elevation at time of drilling(ATD)or on date noted. Groundwater ATD levels can fluctuate due to precipitation,seasonal conditions,and other factors, Padilla Adu C=ic�ti� t: C7e.0:(7)Te51- 2202 15th Street Soil Classification System and Key Anacor tes, Washington `` ; • TP-1 SAMPLE DATA SOOL.. t i-4.OHHLF GROUNDWATER iti .� i Tracked Excavator E as >, in Excavation Method. h- n, u) Unknown ?, la 2 m 17-2 i o Ground Elevation (ft): „_, 0 c b. E_c E ui in Cn oel inu I- f.7 D -U ►5SS 1 Ol. Soft,brown, moist,organic SILT(Topsoil) ,I-1W d � Loose to medium dense,brown,moist,very silty 1-2 d GS to silly,fine SAND(Weathered Till) 1 -2 - 1-3 3- d GS slit content decreases,becomes coarse to fine SAND o • ;I_ a I r- 1-4 J tt f:S g Ii w _�1-b_ ct `�_�t ML Very stiff to hard,moist,bluish gray,sandy SILT 5Ii M ~ with pebbles and cobbles(Giaciai lilt) J o 6 I • {.g d -- F B Test Pit Completed 06/27/17 _' . Total Depth of Test Pit=7.5 ft. a'- s --1t0 --I a Q IL klo 4 TP a SAMPLE DATA SOIL PROFILE ROU D t ATEF t9 — °w o Tracked Excavator °z t aa n ,L, Excavation Method: F- m to y, n Z ai @ U u) Ground Elevation (ft): Unknown m r�. o :c u) t' 0 0 os U) l-- (J a w` u OL Loose,brown,dry,slightly silty,fine sand with 2-1 it d organics(Topsoil) . .. . •. SLUE Loose to medium dense.brown,maid,very silty r' to silty,fine SAND with organics(FEI) a 2 i I, 2-2_j''�'-- i, r SM Loose to medium dense,brown,moist,very silty -I -i -- to silty,fine SAND(Weathered Till) it c2 6 i Mt. Very stiff to hard,moist,bluish gray,sandy SILT _ with pebbles and cobbles(Gladal Tilt) N 2-3 d CGS u'1-s - - i - c� 2-4 1,_, d _ E - Test Pit Completed 06/27/17 II Total Depth of Test Pit=7,5 ft. u}i U Ill - ,„ 0 a 4' x 1 Notes: 1. Stratigraphic contacts ere based on field interpretations and are approximate. 2. Reference to the text of this report is necessary for a proper understanding of subsurface conditions. ' r� 3. Refer to"Soil Classification System and Key'figure for explanation of graphics and symbols. Padilla Adu Figure I oTe'5 , 22t12 15th Street 1_ �c ofPits Anacortes, Washington 0 of 2) TP.3 SAMPLE DATA SOIL PROFILE GROUNDWATER Tracked Excavator d Excavation Method:. > E a) Z @ co i Ground Elevation(ft): Unknown e Q. a - Q Cz E_c E u,ci) co (13 b r)otl CO I- 0 a — SM Stiff, brown,moist,silly,medium to fine SAND L. 3.1 d GS v th gravel and cobbles(Fill) 2 OL Soft,black to brawn, moist, organic SILT(Relic 8L- 32 T d GS SM NTopsoil) /.— Loose to medium dense,brown,moist,very silty to silty,fine SAND(Weathered Till) -! 4 3-311 d , f sill content decreased a.- H i tL " I! sift content increased r -- s 03-4- j_ a --6 ML Very stiff to hard,moist,bluish gray,sandy SILT Slight in„t with pebbles and cobbles(Glacial Till) itsi �e Test Pit Completed 06/27/17 a Total Depth of Test Pit=7.5 ft. 5 -- 0 4 - s —ins 0 N g } I- W O C W In z 5 to z 0 4 O w to W L z O J ri t7 1.11 C7 o w t i0�ll i l) Cr: Di 0 a ; o' W O CO u w a , 0 x Notcs: 1. Straligraphic contacts are based on field Interpretations and are approximate. r 2. Reference%o the text of This report is necessary for a proper understanding of subsurface conditions. a 3. Refer to"Soli Classification System and Key"figure for explanation of graphics and symbols. 0 Padilla Adu Figure C,eQTeJT 2202 15th Street Log of Test Pits 5 Anacartes, Washington (2 of 2) U.S.SIEVE OPENING IN INCHES I U.S.SIEVE NUMBERS I HYDROMETER 6 4 3 2 1 5 1 3 4 112. 3 6 810 1416 20 30 40 50 60 100140 200 100 I I ¢ .....,sa., , I I I _ f r • 90 --7- w ` I \'? ' 80 _ _ 1 ,bk. k I -:. . ink : a \ 1 \ .660 _ • _ z g c50 • - , •• • q if 40 ---- - • Ll \ 1 : 4 a 30 • - < @ 4- _...,__, Y- , J_ Q a 20 - r r-- in :4- '- 10 CC ilk w 0 100 10 1 0.1 0.01 0.001 5 Grain Size in Millimeters 5 Gravel Sand a Cobbles Silt or Clay F coarse fine coarse medium fine w w o Point Depth Classification LL PL Pi C, Cu P g l TP-1 1.0 Silty, fine SAND (SM) _- z ® TP-1 2.0 Slightly silty,fine SAND (SP-SM) 1.43 2.42 LLI A TP-1 4.5 Slightly silty,coarse to fine SAND with trace gravel (SP-SM) 1.52 5.35 * TP-2 2.0 Silty,medium to fine SAND with trace gravel (SM) i ry .-__-1--. --_ 2 0 TP-2 5.0 Very sandy SILT (ML) :4 Point De th D D60 p D D '70 rse %Fine %Coarse °l Medum %Flne p 10U 50 30 i0 Gravel Gravel Sand Sand Sand °�Fines o ® TP-1 1.0 4.75 0.168 0.137 0.076 0.0 0.0 0.6 4.5 65.5 29.4 8 ® TP-1 2.0 9.5 0.197 0.181 0.152 0.081 0.0 0.1 0.2 0.7 91.6 7.4 o tli A TP-1 4.5 19 0.776 0.632 0.414 0.145 0.0 - 5.3 9.1 54.8 23.7 7.1 13 * TP-2 2.0 37.5 0.258 0.191 0.084 - 5.8 2.9 3.8 16.1 43.5 27.8 U TP-2 5.0 9.5 0.079 0.0 0,7 1.4 8.1 30.8 69.0 x r�l C�= D302I(D80`� Dio) To be well graded: 1 < Cc< 3 and 1,1 Cu = DedD10 et, > 4 for GWorCu > 6,forSW Padilla Adu OeOTeT 2202 15th Street Grain Size Test Data Anacortes Washington I- U.S. SIEVE OPENING IN INCHES I U.S.SIEVE NUMBERS I HYDROMETER 6 3 1.5 ,�a 8 14 20 40 60 4 2 1 . 1/2� 3 6 10 1fi 3U 50 100140200 100. I - I I : T' 1 : I 1 - 20 -- : 1 11 • 90 r e I . _ .. \\_ 80- -J., I..1 _ _ . - ..---- 70 i i'-- - - - I- - _-__ se 76 60 i z - C9 V- a ° ---'- - - fil U U o Cj 40 — 1 ci la30 -- a 0. 20 I k. ___ , 0 >- '10it( :it a I- A 0 z, 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters z o Gravel Sand — Cobbles coarse fine coarse medium fine Silt or Clay w a 1 Point Depth Classification LL PL PI C, Cu P g 0 TP 3 2.0 Silty,fine SAND (SM) z ® TP-3 3.5 Slightly silty, coarse to fine SAND with trace gravel (SP-SM) - 1.05 4.58 w 1;1- R rn w "/oCaarseine %Coarse %Medium %Fine o Point Depth D100 den Duo Q30 Di() Gravel Gravel Sand Sand Sand /o Fines c 0 TP-3 2.0 9.5 0.182 0.158 0.089 0.0 0.0 0.2 2.6 72.6 24.6 § 1r TP-3 3.5 10 0.499 0.367 0.239 0.109 OM 9.5 9.4 24.1 50.0 7.0 6 w 0 r -- o aI - - - ' 6 N. Cc= D302I(Dsa* Dia) To be well graded: 1 < Cc< 3 and c- Cu = Dedato Cu > 4 for GWorCuy6 for SW Padilla Adu Figure c,eoTe5T 2202 15th Street Grain Size Test Data Anacortes, Washington I k •/ Northwest AgrictAtural GeoTest Services Inc. 741 Marine Drive - Bellingham,WA 98225 2545 W Falls Avenue PAP-Accredited Kennewick, WA 99336 509.783.7450 s Report:41439-1 www.nwag.com lab@nwag.com :F Date:June 30,2017 Project No: 17-0425 Project Name: Padilla Adu Sample ID pH Organic Matter Cation Exchange Capacity TP-1 @ 1.5' 5,6 6.34% 11.8 meq/100g TP-2 @ 5.0' 55 7.78% 21.5 meq/100g TP-3 @ 3.5' 6.8 3.65% 6.1 meq/100g Method SM 4500-H+B ASTM D2974 EPA 9081 REPORT LIMITATIONS AND GUIDELINES FOR ITS USE1 Subsurface issues may cause construction delays, cost overruns, claims, and disputes. While you cannot eliminate all such risks, you can manage them. The following information is provided to help: Geotechnical Services are Performed for Specific Purposes, Persons, and Projects At GeoTest our geotechnical engineers and geologists structure their services to meet specific needs of our clients. A geotechnical engineering study conducted for a civil engineer may not fulfill the needs of an owner, a construction contractor or even another civil engineer. Because each geotechnical engineering study is unique, each geotechnical engineering report is unique, prepared solely for the client. No one except you should rely on your geotechnicai engineer who prepared it. And no one—not even you—should apply the report for any purpose or project except the one originally contemplated. Read the Full Report Serious problems have occurred because those relying on a geotechnical engineering report did not read it all. Do not rely on an executive summary. Do not read selected elements only. A Geotechnical Engineering Report is Based on a Unique Set of Project-Specific Factors GeoTest's geotechnical engineers consider a number of unique, project-specific factors when establishing the scope of a study. Typical factors include: the clients goals, objectives, and risk management preferences; the general nature of the structure involved its size, and configuration; the location of the structure on the site; and other planned or existing site improvements, such as access roads, parking lots, and underground utilities. Unless GeoTest, who conducted the study specifically states otherwise, do not rely on a geotechnical engineering report that was: • not prepared for you, • not prepared for your project, • not prepared for the specific site explored, or • completed before important project changes were made. Typical changes that can erode the reliability of an existing geotechnical engineering report include those that affect: • the function of the proposed structure, as when it's changed, for example, from a parking garage to an office building,or from a light industrial plant to a refrigerated warehouse, • elevation, configuration, location, orientation, or weight of the proposed construction, • alterations in drainage designs; or • composition of the design team; the passage of time; man-made alterations and construction whether on or adjacent to the site; or by natural alterations and events, such as floods, earthquakes or groundwater fluctuations; or project ownership. Always inform GeoTest's geotechnical engineer of project changes — even minor ones — and request an assessment of their impact. Geotechnical engineers cannot accept responsibility or liability for problems that occur because their reports do not consider developments of which they were not informed. 'Information in this document is based upon material developed by ASFE,Professional Firms Practicing in the Geosciences(asfe.org) C'COTGST Subsurface Conditions Can Change This geotechnical or geologic report is based on conditions that existed at the time the study was performed. Do not rely on the findings and conclusions of this report, whose adequacy may have been affected by: the passage of time; by man-made events, such as construction on or adjacent to the site; or by natural events, such as floods, earthquakes, or groundwater fluctuations. Always contact GeoTest before applying the report to determine if it is still relevant. A minor amount of additional testing or analysis will help determine if the report remains applicable. Most Geotechnical and Geologic Findings are Professional Opinions Our site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoTest's engineers and geologists review field and laboratory data and then apply their professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ—sometimes significantly—from those indicated in your report. Retaining GeoTest who developed this report to provide construction observation is the most effective method of managing the risks associated with anticipated or unanticipated conditions. A Report's Recommendations are Not Final Do not over-rely on the construction recommendations included in this report. Those recommendations are not final, because geotechnical engineers or geologists develop them principally from judgment and opinion. GeoTest's geotechnical engineers or geologists can finalize their recommendations only by observing actual subsurface conditions revealed during construction. GeoTest cannot assume responsibility or liability for the report's recommendations if our firm does not perform the construction observation. A Geotechnical Engineering or Geologic Report may be Subject to Misinterpretation Misinterpretation of this report by other design team members can result in costly problems. Lower that risk by having GeoTest confer with appropriate members of the design team after submitting the report. Also, we suggest retaining GeoTest to review pertinent elements of the design teams plans and specifications. Contractors can also misinterpret a geotechnical engineering report. Reduce that risk by having GeoTest participate in pre-bid and preconstruction conferences, and by providing construction observation. Do not Redraw the Exploration Logs Our geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors of omissions, the logs included in this report should never be redrawn for inclusion in architectural or other design drawings. Only photographic or electronic reproduction is acceptable; but recognizes that separating logs from the report can elevate risk. Give Contractors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnical engineering report, but preface it with a clearly written letter of transmittal. In that letter, consider advising the contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited; encourage them to confer with the GeoTest and/or to conduct 'Information in this document is based upon material developed by ASFE,Professional Firms Practicing in the Geosctences(aste.org) oeoie6r additional study to obtain the specific types of information they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might you be in a position to give contractors the best information available, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. In addition, it is recommended that a contingency for unanticipated conditions be included in your project budget and schedule. Read Responsibility Provisions Closely Some clients, design professionals, and contractors do not recognize that geotechnical engineering or geology is far less exact than other engineering disciplines. This lack of understanding can create unrealistic expectations that can lead to disappointments, claims, and disputes. To help reduce risk, GeoTest includes an explanatory limitations section in our reports. Read these provisions closely. Ask questions and we encourage our clients or their representative to contact our office if you are unclear as to how these provisions apply to your project. Environmental Concerns Are Not Covered in this Geotechnical or Geologic Report The equipment, techniques, and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated containments, etc. If you have not yet obtained your own environmental information,ask your geotechnical consultant for risk management guidance. Do not rely on environmental report prepared for some one else. Obtain Professional Assistance to Deal with Biological Pollutants Diverse strategies can be applied during building design, construction, operation, and maintenance to prevent significant amounts biological pollutants from growing on indoor surfaces. Biological pollutants includes but is not limited to molds, fungi, spores, bacteria and viruses. To be effective, all such strategies should be devised for the express purpose of prevention, integrated into a comprehensive plan, and executed with diligent oversight by a professional biological pollutant prevention consultant. Because just a small amount of water or moisture can lead to the development of severe biological infestations, a number of prevention strategies focus on keeping building surfaces dry. While groundwater, water infiltration, and similar issues may have been addressed as part of this study, the geotechnical engineer or geologist in charge of this project is not a biological pollutant prevention consultant; none of the services preformed in connection with this geotechnical engineering or geological study were designed or conducted for the purpose of preventing biological infestations. 'infonnalion in this document is based upon materiel developed by ASFE,Professional Firms Practicing in the Geosdences(asre.org) h � s isecTe5T ' I 741 Manna Dive Bellingham,WA 98225 360 733 7318 V oeoTG sT 20611-67d'Avenue WA 98223E EEE 251 527E 380 733_7418 October 24, 2017 Job No. 17-0425 Landed Gentry Homes and Communities 504 East Fairhaven Avenue Burlington, WA 98233 Attn.: Steven Baughn Re: Stormwater Infiltration Evaluation Memo Padilla ADU Development 2202 151h Street Anacortes, Washington Dear Mr. Baughn, As requested, GeoTest Services, Inc. (GTS) is pleased to submit this memorandum disusing the effects of stormwater from the proposed infiltration trench on the adjacent residential foundations. It is our understanding that the City of Anacortes Planning Department has concerns that the foundation setback distances from the trench might not meet the suggested guidelines put forth in the 2014 DOE Stormwater Manual for Western Washington and may have 'a significant negative impact on the surrounding foundations'. The manual suggests that infiltration trenches be placed at least 20 feet from uphill foundations and 100 feet away from downhill foundations. The proposed infiltration trench is to be situated 20 feet north of the proposed residence on the subject property and runs east to west for 46 feet. The existing residence on the neighboring property to the north is 48 feet away from the proposed infiltration trench. Topography on the property slopes gently downward to the north, dropping approximately 1 foot in elevation from the trench to the neighboring residence, giving a gradient of 1 degree or 2 percent. Based upon the relatively flat topography and the fact that the upper 4 feet of the existing site soils contain weathered till that can be infiltrated into at a rate of 1.5 inches per hour, in our opinion, it is extremely unlikely that the location of the proposed trench would negatively impact the surrounding foundations. Page 1 of 2 Geolest Services, Inc. October24,2017 2202 15th Street,Anacortes,WA Job No. 17-0425 We appreciate the opportunity to be of service to you on this project. If any questions should arise regarding this report, please contact the undersigned. Respectfully Submitted, GeoTest Services, Inc. 401 I , L.4.0: .'0 r ., (,,n2istennt Geabtat y/ 00 420 �hyed Ge° Tim Chylla Tim Chylla, L.E.G. Engineering Geologist Attachments Figure 1 Vicinity Map Figure 2 Site Plan References Washington State Department of Ecology, 2012 (amended December 2014). Stormwater Management Manual for Western Washington. Page 2 of 2 II PROJECT LOCATION il 1 I , 1 .;.< Pr" 1 t,. , tr • Z .. , 1.1. Ili r.• i 4 4' Z. , • • .1,'' • I • • 9 , it• .• r .41,1 -Gr4Atrirlitil ".. , 1 Crann641) 'i I;Me P•rk t, 0 , - 1 .4 CI. Idli ) 0.11 • 5./ , I- 'r, ^,,% q f .1 „ '';' r r ; ,..,..., i , r . f At%•. ' )1 7 fr..•2' '' . i , • 1 \ •A' 1‘ i ii f i I i . 1" .• +I , 0 1 IV MAP REFERENCED FROM GOOGLE MAPS 1 i n nrA N Date: 8-30-17 By: JS Scale: As Shown Project GEOTEST SERVICES, INC. VICINITY MAP 17-0425 741 Marine Drive 1 Bellingham,WA 98225 PADILLA ADU Figure phone: (360)733-7318 2202 15TH STREET fax: (360)733-7418 ANACORTES,WASHINGTON I .=9RRT_VI 4VD LgGAL QESCRIP fON:. ?HI "A3' PACT Cr LO7 17. ALONG YATYi Au. GT LOTS it —. :;', AND 20. OF d_CCK ROE AS PER SL'RfFY RECORDEC -' 0%57 ? 4v3.'XS FILE &JMBER 20030*17C.'56. RECORDS - \ ll 7. U C: I. \ 'I' R�• Or 5<I.GT r../lr%�.• Y, CTA :F ILO WASMN.^.'t].v. - . . .. 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Y!-i' • • L" I, D� .-.•:-s�.+.wa.•r • -•eay.I �r A,e.rAr..�.-.. • ($STD Fill • .]. I. t ....`T. ,YF- f../ .•,1-•-.,..'n . .I .•-.•....' .• n, y . 'Jlltx 4 .. •_ _. —.-.—.• -I . ` j/ -� • =l• - .0 MLE,Y. Z _ �,,:�_.� .y .r•, .� . .. .n.v.e...•w I I e C!Z1'.EtU,'G I111 :.:.E . •C. .•,•r,.v:•.ir., m nrwo-errr-. .'rv,.a a.•.,• •r �:•• Y.,] • -'i r `—� • -- GRAPHIC SCALE .,.aY•.�.. • cATMs. - .. Act =II tl 70 0 5 fO 20 - , 61P CI GI NIGH VISIPCIT' ale Mel • Sint seen s /ne1. a ID rat PLASTIC i.- • e T 0 AEDUCE IifEK CIF FORM CONCRETE ORNEWAY EMP C:70F, r:•EISILI Y 64 • . .IYCJ EI:TRYINT000NSTRUCTION SURFA.M TOSECROSS PLASTIC PENCE inn PADILLAADU rt:E•.R-v y SITE SLOPED 7b.MINIMUM TO TO REDUCERISI(aF PUBLIC — — — �IwosED of TO BE r - - e�w.ac9$S .t1ION - -- --:—x S. i -- — --- _ _ 3-CAR GARAGE CENTER K T..= 15TH STREET cAwN,LANDSCAPE AREA, EROSION CONTROL PLAN r t & UD IMPROVEMENT PLAN P56250 • - • 220215TH STREET . r ANACORTES, WA .Oe'Ce PLAT OFfllNOR'TH- Gmvv: LG ... WIT 1602:017 ..--. ._ a.m 1 of 2 'I -_. .— �_-...._ _ -. _ . . -. - - --. ------_. - -- HOUSE-WWHM VIEWS AND REPORT i e -<"ew ie-r 4. ,':-Jm-frop gu. F--- -- _____ . . crx _1 '411111114111.4. ,f I iv.j .. ati Bala I FredCrelapeti ::.f__..;.:3 Subbasin Name- tBes+n 1 �_ .! _-1 Surface 1ptetNow Groundwater -- Mitigated Area in Basin f� tinNrOriiSe d Run scenaric Available Pervious Available Impervious _ riC.Fnresi.Flat 1,Qi7 4 R 5 0764 S1R.AT 1 '0 OM ; r 1 i Mil I 1i / r 111016 1,,, iii OM!in. I, D .1* . •..si 1, 1! ,, ,. .. Move Elements --- Perv+ousTote 3077`- Acres ImperviousToleS : Aaes 4. 41 'Ft • BnsinTaiel A 077 —-1:1Acm aveY+}. Lc�cixy t _- _ . )e--;30::1:-"v..-�� Sa6etii GO - 9r2 7 Oi 3:17 PM IIJL- ll V41 V,'i-i v!3 woi...r13se2 Pe Ed!: Ve : 1-.ere 1 0 GI 6 - . e-• . . Illiii) lite-;1I INN ID iti r! • - - ; i Basin I.tiolosgated SCENARIOS —I Subbasin Name_ ,IBELSM 1 -I r Designate as Bypass for POC i , i r Predeveloped • i Surface anterflow Groundwater ), 1 . Flows To : r-- Gravel Trench Bed 1 .: Ibeveltre-nch Be-ii 1— —--..i 1- -—------ -- -. L______ _ sli,) n I i. __Area in Basin 17 ShowOhf ySelectezi Run Scenario • I Available Pervious Available Impervious 4. CArittt iiiei- - TR i..- -gbo-Ft7:507101.7c-i-' Pt FKIPAITS llill , . _ . a lki,,, _., .... ....„ i zalicl 1 iN 1 1 . ... i it i... il )1 1 i 1 i I Move Elements I PervlousTota ! Ames impervious Toted tiff-7: Mres 441 —IC WP W Basin Total iiiin------1 Acres . . ! .... .- 3ave xy i Load xy.i ti it-0 . 1 _ --- — Deselect Zero Select Br GO . _ _ _ tiliti'irr-`,,13 tm3Hazate2 » r► le .di: 1.e:c ZGct?• Hal: It l ice._ Ilb big._ '�``�" i&I'lq-- It'd - .aa-vrevh•n�:.x_•n rhl'>.+e�.rr+••st—+.�r:r—.mar_*—_�.-. _ �-1 ?::.Gihwr•._•^sc main _ v Fry i 1 • 'I SCENARIOS lI E! Facility Name Gravel TretichBed l f'Prade�+elo d —..• 't Outlet t Outlet 2 -, Outlet S it DownstreamConnection 0 111. Elp;`'i9tte'= ; Facility Type GravelTrench/Bed Preapttenot:Applied to FacArty Quick Trench .1 1--- Run Scenario—I i FI FMFinn :..vaponstiot a.keiedtoFe,d1I ' Facility Bottom Elevation (ft) I" IImilli. <-. Facility Dimensions Trench Length 'f_ Outlet Structure g {ffJ •�--::,-. 1���g Trench BoBomWidti, t�iserHei Height RiserDlameter(in) 112-1 IImar. �i 12:1 � Effective Depth ,3 _ _ ` ILaJ i Bottom slope of Trench t0001�Lir11 Riser Type ;Flat ---_-1 Type aii, � L.eftSide Slope :0 Notch _ e Right Side Slope II Material Layers for Trench/Bed Layer 1 Thickmess(it) .2 Orifice Diameter Height ( Max Layerl porosity i033 Number (In) (Ft) (cfs) Byer 2 Thickness(It) :0 1 16- -1 ,0 a. } Layer 2 porosity 8 2la =.I <�--"-:-.1 4 Layer 3 Thickness(1t) id S IF----- j0 .10 Layer porosity °tl Infiltration YES f< Trench Volume at Riser Head(acre-ft) .001 Move EIvmen •- Measured Idill _tration Rate fin/hr) (6.33 Pond increment 0.10� e Short Pond Table OpenTeble c �' Infiltration Reduction Factor(nfilt"`lactor) i1 ;� ...� t Use Wetted Surface Area(side>,valis) frES M .-: Total Volume infiltrated(acre-t 6.807 Total Volume Through Facility(ecre-ft) 6.807 :are xy i xv r Total Volume Through Riser(ecre-ft) 0.801 Percent Infiltrated 100 1O w 1 Wastern Washington Hydrology Model PROJECT REPORT Project Name: wwhm3House2 Site Address: City : Report Date : 9/27/2017 Gage Burlington Data Start 1948/10/01 Data End : 1999/09/30 Precip Scale: 0 . 83 WWHM3 Version: P (EDEVELOPED LAND USE Name Basin 1 Bypass : No Groundwater-: No Pervious Land Use Acres Cr Forest, Flat . 077 Impervious Land Use Acres Element Flown To: Surface Interfiors Groundwater Name : Basin 1 Bypass : No Groundwater: No Pervious Land Use Acres Impervious Land Use Acres ROOF TOPS FLAT 0 . 077 Element Flows To: Surface Interflow Groundwater Gravel Trench Bed 1, Gravel Trench Bed 1, Name : Gravel Trench Bed 1 Bottom Length: 4 6 f t . Bottom Width : 2ft. Trench bottom slope 1: 0.000001 To 1 Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer : 2 Pour Space of material for first layer : 0.33 Material thickness of second layer : 0 Pour Space of material for second layer : 0 Material thickness of third layer : 0 Pour Space of material for third layer : 0 Infiltration On Infiltration rate : 6.33 Infiltration saftey factor : 1 Wetted surface area On Discharge Structure Riser Height: 2 ft. Riser Diameter: 12 in. Element Flows To: Outlet 1 Outlet 2 Gravel Trench Bed Hydraulic Table Stage(ft) Area(acr) Volume(acr-ft) Dechzg(ofs) Infilt(ofs) 0.000 0. 002 0. 000 0.000 0.000 0.033 0. 002 0.000 0.000 0.014 0.067 0.002 0.000 0.000 0.014 0. 100 0.002 0.000 0.000 0.015 0.133 0.002 0.000 0.000 0.015 0.167 0.002 0.000 0.000 0.016 0.200 0.002 0.000 0.000 0.016 0.233 0.002 0.000 0.000 0.017 0.267 0.002 0.000 0.000 0.017 0.300 0.002 0.000 0.000 0.018 0.333 0.002 0.000 0.000 0.018 0.367 0.002 0.000 0.000 0.019 0. 400 0.002 0.000 0.000 0. 019 0.433 0.002 0.000 0.000 0. 020 0.467 0.002 0.000 0.000 0.020 0.500 0.002 0.000 0.000 0.021 0.533 0.002 0.000 0.000 0.021 0.567 0.002 0.000 0.000 0.021 0. 600 0.002 0.000 0.000 0.022 0. 633 0.002 0.000 0.000 0. 022 0.667 0.002 0.000 0.000 0. 023 0.700 0.002 0.000 0.000 0.023 0.733 0.002 0.001 0.000 0. 024 0.767 0.002 0.001 0.000 0.024 0.800 0. 002 0.001 0.000 0.025 0.833 0.002 0.001 0.000 0.025 0.867 0.002 0.001 0.000 0.026 0.900 0.002 0.001 0.000 0.026 0.933 0.002 0.001 0.000 0.027 0. 967 0.002 0.001 0.000 0.027 1.000 0.002 0,001 0.000 0.028 1.033 0.002 0.001 0.000 0.028 CO 01 01 O O r d r-1 N N Cr) M *chi d In tU C,O k.0 CD N N 00 c0 C)1 61 O O r-I H N N Cr) Cr) C'') 1 v+ if) L) (0 CD N N Co Co C N 0') O O r-1 r-1 H N N OD Cr) NV c1+ 1.0 N N N 00 Cr) Cr) Cl 00 Cr) 01 Cl Cr) Cl 01 00 Cr") Cr) Cr) Cr") 01 00 Cr) Cr) 01 cr yr ar d' NV Nil NV NV d• N1♦ NV NV 'c1• NV NV NV v+ NV Ul Ur) LU L1 UD Cn Ln IC) Ln Ln Ln 1.0 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O Ca 0 0 O O O C) O 0 0 0 0 CD 0 0 0 0 0 0 0 0 CD O O O O O C7 0 O O O O O O 0 0 CD 0 0 CO O O O O O O O O O O O O O O O CD 0 0 C) O O O O O O O O 0 0 0 0 0 0 0 0 O O O O O O O O O Q 0 0 0 IT 00 CO NV Cl r-i CO 1.--1 O v N NW CO LC) Cr) Cr') eV CO61 rA NV lD 0) 01 C31 CO i) N O CD O O O O O O O O D O 0 0 0 0 0 0 0 0 0 O O O O O O O O uD VD O C- tD N C71 v+ O N CD la N O c" 0\ LU N O O O ri Cr) VP O I.r) r-1 Co 0 0 0 0 0 0 O O O O 0 0 0 0 0 0 0 0 O O O O O O O 0 0 0 0 O H Cr) 4r CO Co O Cr) V0 CO r I N r-i N ri u1 C3) Cr") C` ri ic) 01 Nv CO 01 N o• o CD 0 O O O O D 0 0 0 0 0 0 0 0 0 0 0 0 O O O O O O O O O O O O O O r1 ri H H N N N Cr) CO 01 NV NV u) In CO CO <D N C- co Co r-1 r-i r-i ri r4 r-1 rH r-1 r4 r-1 r-1 r^i ri r-1 r I c-I r-1 c-1 r-{ ri r-i r-i r! c-1 r-I r-1 r-1 1--1 N CV N CV CV N N N N N N N N N N on P1 01 00 01 01 01 01 01 01 01 M 01 O O O D 0 0 0 O O O O O O O O O O O O O O O O O O O O O O O CD C7 0 0 0 0 0 O CD 0 0 0 O O O CD 0 0 C) 0 0 0 C) 0 0 O O O O O O O CD O O O O O O O O O O O O O O O O O O O D O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 < ♦ . . . O O C: O O O O O O O O O O O O O O O O O O CD 0 CD CD 0 0 0 0 0 0 0 0 C) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C) 0 0 N N N N N N N N N N N N N N N CV N NNN NNN N N CV N N CV NNN N N N N N N N N N CV N N NNN NNN N CV N N N N CV O CO O C: 0 0 0 0 0 0 O O O O CD O O O O O O O O O O O 0 0 0 O O O O O O O O O O O O O O O O O O 0 0 0 0 0 0 0 O O O O O O CD CD O O D CD CD 0 0 CD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0• 0 0 C) 0 0 0 O O C? O O CD Ca 0 0 0 0 CO C7 O O O O O O O C) O O D O O O CD C) O Ca O CD O CD C) CD 0 0 0 0 0 0 0 0 0 0 0 O O N O co N O Cl N CD Cr) r- O Cr') f D CO t- O N O 01 r- O 07 N O 01 N CD 01 r- C) 01 N O M r- O CO r- CD co N O Cr) N O Cr) N O Cr) N O Cr) C- O CO QD O 01 CD O 01 C D O 01 W O CO VD O 01 MD CD 01 D 0/ VD O 01 CO O C D lD O 01 W O m QO O 01 CD O 01 CCS p CO lD O 01 tD O 01 CD O 01 w O 01 VD O 01 O H H H N N CV Cr) Cr) 01 cP IIC) u? Ln CO CO CO N C- C- op OD oa 0l on 0') Q O a r-1 H H N CV N Cr') Cr) Cr) es+ cr yr LU IS) I.n CO CD lD r- l- N CO CO 0) C71 0') r-I r--1 ri r-1 r-1 r--i r--1 c-i r-1 r-1 r-I rl r-1 rH rH r-i r-1 r-1 ri ri rd rH r-1 r q r-I ri N N N CV CV N NNN N N N N N N N N CV N N N N CV N N CV N N N . 2.967 0. 002 0 003 9.256 0.055 3. 000 0. 002 0.004 9.739 0.056 MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.000768 5 year 0.001605 10 year 0.002242 25 year 0.003085 50 year 0.00372 100 year 0.004346 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.003 0.000 1951 0.002 0.000 1952 0.001 0.000 1953 0.001 0.000 1954 0.000 0.000 1955 0.001 0.000 1956 0.001 0.000 1957 0.001 0.000 1958 0.001 0.000 1959 0.001 0.000 1960 0.002 0.000 1961 0.001 0.000 1962 0.000 0.000 1963 0.000 0.000 1964 0.000 0.000 1965 0.001 0.000 1966 0.001 0.003 1967 0.000 0.000 1968 0.001 0.000 1969 0.002 0.000 1970 0.000 0.000 1971 0.000 0.000 1972 0.002 0.000 1973 0.001 0.000 1974 0.000 0. 000 1975 0.002 0.000 1976 0.007 0.000 1977 0.000 0.000 1978 0.000 0.000 1979 0.001 0.000 1980 0.000 0. 000 1981 0. 001 0.000 1982 0.001 0. 000 1983 0.002 0. 000 1989 0.001 0.000 1985 0.002 0.000 1986 0.000 0.000 1987 0.001 0.000 1988 0.001 0.000 1989 0.002 0.000 1990 0.001 0.000 1991 0.001 0.000 1992 0.002 0.000 1993 0.001 0.000 1994 0.001 0.000 1995 0.000 0.000 1996 0.000 0.000 1997 0.001 0.000 199B 0.003 0.000 1999 0.001 0.000 2000 0.000 0.000 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0067 0. 0034 2 0.0029 0.0000 3 0.0029 0.0000 9 0.0024 0.0000 5 0.0020 0.0000 6 0.0020 0.0000 7 0.0019 0.0000 8 0.0017 0.0000 9 0.0017 0.0000 10 0.0016 0.0000 11 0.0016 0.0000 12 0.0015 0.0000 13 0.0013 0.0000 14 0.0012 0.0000 15 0.0012 0.0000 16 0.0012 0.0000 17 0.0012 0.0000 18 0.0009 0.0000 19 0.0009 0.0000 20 0.0009 0.0000 21 0.0009 0.0000 22 0.0008 0. 0000 23 0.0008 0. 0000 24 0.0008 0. 0000 25 0.0008 0. 0000 26 0.0007 0.0000 27 0.0007 0.0000 28 0.0007 0.0000 .14 F3'e • G• f) lf) U) U) CO (5 Cr) U) U) U3 V? U) Ca U) Ell Cri U) U) U) Et) CO U) CO 0 Ca O o Co Q 0 0 CD Ca Ca O C> 0 C) Q 0 0 0 0 Ca 0 0 63 CO Cl) U) Cl) Cl) U) CO Cl) Cl) Cl) CO U) U3 U) Cl) U) (r) Cl) U) Cl) Cl) Cl) Cl) Cl) Cl) U) o O 0 O 0 o O 0 0 0 0 C> 0 O O O O o O 0 O 0 0 , ;i CCS ct, sCS It (ti sCl rC cL# ca sC sly c� cci c- c,� EC tC5 c) a) cd 000C) 000 oo © 000000000000 a: a 04 04 04 124 O4 O4O.: W waa 04 at040: t1: 404 /1404cL p-4 Ca Q O C) O Q 0 0 0 Ca O C7 0 0 0 0 0 0 C? C7 Ca Ca 0 @ O > 40 0 0O > 4. 6 004 0 a 0 c CP CD C C CD D C CD CD CD CDCD CD CD CDCD 0 0 C) CD CD O 0 0 CD O o CD CD Q O CD O CD CD 0 0 0 d o 0 0 0 CD CD CD CD O 0 0 CD CO a N N N N N N CV CV N N N N N CV N CV N CV CV N CV Chi N CV N N �1 is CT) OO Ul o N r- r- LC) c 'qv ' � N N r-if ' CI CV s--9 -1 C) CD CD C) CD 0 0 Li) CD 0 0 CD CD CD 0 a C� CD CD CDC) CD CD CD CD04 '0 O CV r-i s.n sr C CV sr Ul L ) sr CD r-1 Lf) O CD Ca 0 O O CD CD CD O O O CD CD CD Q CD o C7 CD CD C7 CD C) Li) CO LC) N cr r-1 0 —1 sr Ch CSJ M r-f N CO 'ig L ) a-4 er Cr Lf) O O O O CD CD CD CD Ca CD O O C7 CD 0 O 0 O C7 0 CD O C °4 r 1.0 01 .* o r- C`d 0 W C.0 sr i ) CV r4 CD N 111 0) G\ cgs Ca u-) CD r- 00 • Oa 00000400 0000000000 -1 4-) 00. sr 01 (r) 0 N N (\a CV 4--I rd 5-I r-1 ti I r4 r4 al CO N C` %C. 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(v R) w (I 0) 0.1 Q R) RI m 03 1v c w a N (1) 0.1 0) W W W tv W W Co 03 W W cv >u w Co 0) 01 03 (v w Cn Cn U1 to Cn U1 Cn Cn CO U] U] Gl (!) C4 U) Cn (n U) U] m Cn U) (!) Cn Cn U) G9 Cr) Cn Co Cn Cn (1) Cn CO CA Cn CA Cn CO U) CD CO U) Ch U) U) U) (n Cn CA U) Cn to U) Cn Cn CO Cn U) CO (n Cn Cn in CO Cn Cn Cn Cn Cn Cn Tn Cn L9 Cn Cn En Cn En Cn U) Cn U) U) Cn Cn Co Co Cn Cn (n CI) Cn Cn to Cr) Cn Cn Cn C)) G9 Cn U) Cl] 1n Cn Cn Cn Cn Cn Cn CI) Cn 0 . 0032 36 2 5 Pass 0 . 0032 36 2 5 Pass 0 . 0032 35 2 5 Pass 0 . 0033 35 2 5 Pass 0 . 0033 34 2 5 Pass 0 . 0033 33 2 6 Pass 0 . 0034 33 2 6 Pass 0. 0034 32 0 0 Pass 0. 0035 31 0 0 Pass 0. 0035 31 0 0 Pass 0. 0035 31 0 0 Pass 0 . 0036 30 0 0 Pass ' 0 . 0036 30 0 0 Pass 0 . 0036 29 0 0 Pass 0 . 0037 27 0 0 Pass 0 . 0037 27 0 0 Pass 0 . 0037 26 0 0 Pass Water Quality BHP Flow and Volume for POC 1. On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Perind and l'mpind Changes No changes have been made. This program and accompanying documentation is provided 'as-is ' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages. DRIVEWAY-WWI VIEWS AND REPORT i14MlHtvi3 Y.e'!S`q.i;O:FSe2 - -- -------- --- Tie Edit TetY He.� r ax w:.��--- "_'•acG.:•:a.dn•-_-s.6 5-fart-:_asv-•• - a-'- -� .-eao*ed:t.:.e a,.s.sam.-. er..:�rsr va-a_^J' .: -..._..u-tea• �_�.._.- ...r.- ._�. 'r 1 501 POC 1 Pmdeveiaped/ L 2,074 :'_a an:1 o 10E1 xxzxxxzxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx 701IrrilowttPOC1 M igatl 7101-.(C3'9} 0501 0701 0601 ,1 801 P C 1 Mingatedtlaw j 112 76" , 0.0006 0."v_76 0.COCO -- --- - --- --._ 1i5 Yea.= 4 C .::le 0.0243 0.0000 !13 :ear = 0.0022 0.0292 C 0000 ., i!j2E 'ear = C .003_ 0. 0339 0.0CC0 t5 gQlEO ih, eQ-a = 0.0037 0.0d1 2 r .0000 `. tes t, Yza.7. Q 0.0043 0.0471 000 i, k' d 1949 000�25 : 022C 0.0LNO a 949 �.O'V19 °+f hi J 10E-1 _ � � 3.350 L�.OQ16 Oo��; . 0.0000 !i e331 0.0012 0_Co 0.0000 ae &npa e 1932 G.0005 C.b1ec o.0000 -. ae4eec o e e e e 1353 0.0004 0.0222 0.0000 - 195�i C.0006 0.0131 0.0000 i0E-2 pane -< °��_ . 1 10 20 SO 40 50 80 70 € 0 90 90 :- 1955 0..0007 0.0107 0.0000 19a6 0..0007 0_010e' 0.0000 C u u �kktive PIFt ib i? 0 19.57 0.0012 0.0232 0.0000 -' q 1358 0.0005 0.0160 0.0000 Durations Flow Frequency j We2er Oue dty I Hydrogreph�..._._�Wetland Fluct atiorr ii :.959 0.0015 0.0113 0.0000 1940 0.0006 0.023E 0.0000 AYAnalyzedease4s b 195: 0.000 0.0136 0.0000 _ .__._.__ _ 1 �a o.00ac e.o2o� 0.0000 1 Pth ALWPDAiL'1 EVAPVt�1,1EN-SEt4d-HAISE '26URUNGTONPREOP 19553 0. 0004 0.0108 0 .0000 9 1sa4 0.0007 0.0210 0 .0:0 11 :966 >.v 012 0.0479 003 '.v .l7Nei 195a 0. 0003 ti .013. g 0NosRol 10l 0 Gravel Trench Bed 1 ALL OUTLETS Mitigetad v. 1801 Gravel Trench Bed 1 OUTLETI Mrhgated 'j 1967 0.0008 0.0336 e. .0<60 1002 Gravel Trench Bed 1 OUTLET2 MIbgated 1 1958 0.0017 0.0270 0.0000 1969 0 .0004 0.0105 v.4Cd0 AN Oatesets Flow! stage) PreciPTEv$p j POC 1 1970 4.00oa 0.0?43 0..0000 A _.. - 1971 .-.9L1 9 C.:an e .000 Flood Frequency Method it 1372 0.0008 C.0129 v.GCCC a Log Pearson Type ll1178 j 1973 0.0004 0.0:.32 0.^.b'0 0 WetbuU ', . Qi4 n n.!Z1'p :': a.,,g, P i-,a P t" t�smene �f 0L . Pal w1 !L r l4 i 1 °HM3 dr+vewayz loci ID 4111WH 1 is Ar-,a -. rys�. _till 1r l 1 F'redevelapetl9 jirmbt° 2"o 3^ <;y _ __^ 18E 1 r_ 801 FLOC 1 Mitigatedflow ;►='.t0t,'(US) 030_ Ot301 i 2 Year. 3003 0.0064 !;s ?SAX n 0.000E 3.0088 - r_ Moat. 3.0008 0.00.03 ti ' 1�E� ,!2:5 Yeary .col:, V.V:vs [SO Yea: 4.0014 0.315C 1;133 Year. 0.0013 3.0171 i 0 1849 L.OO1C b.�r+^i�v j 10E-1 .. 1331 0.0004 0.0072 I; 13E2 0.0003 0."06.. U 1333 0.0001 C.07.g1 !! ai4 0.00002 m. 00S3 10E-e _ . r , r,_ , 10 20 30 40 *. s:�.^ 90 99 i; a33s 4.COC2 .00�3 1k��I�d�:�!'(�.1 abilityij ;3}56 00.0003 4 0 .3039 3.7 of.v Vi�9 0,0084 r- -- ° li 1.306 0.0002 S.;Ca8 �,e ooras Floor►rrFrequency +inter Oueliijr Hydrograph !Wetland Fluetuetion j li :3=3 0. 0006 0.3041 11 1r.a.r 0 O:C3 0 .0084 Analyze damsels P 1931 0 0002 C. 0050 r1 1'UyAu.l_UPDAILYEVAPw/JENSEl4-HAISE .w..._.-..,_s lI 1s52 0.0003 3.307E y `2 8URLtNGTON PRECIP li1341 0.0002 C.4 V w, ..mwomminim I 1364 0 000''= 3 . 30 70 1000 Gravel Tr nch Bed 1 A OUTLETS Mitigated 19 Say /C.0331 fl Caa . �"4 .i. 042 i 1001 Gravel Trench Bed 1 OUTLET1 Mitigated 1 =3 6 : w,00 3 .yy 3122 `22 100 Gravel Trench Bed 1 OLtTLET 2 Mr�geted 1003 Gravel Trench Bed 1 STAGE MIrilgafed d 3 68 v.0306 0.0093 0 _�..._....a 13s3 0.00D1 0.0C33 Acre., l OE4esets 1 Flow Stage Pt9ap 1=vap Fos 1 _ ..3 . 0.0001 0.0125 1 1371 0.0007 0..10 67 Flood Frequency Method ;i 1372 0.0003 0 CL 4'7 ,® Log PearsonTypel11178 ll 13?3 0..0002 -.30a6 ' Weibull ; c r1 nfl71C ^ ^.^.. � C.unnane - il: ; L t e"A'd�SM3 driveway 2 :ie Edit 'r ett -;e!;, M F _ _ lam` *gig- rilltil If I . <-7" ID . 235V., S.'o[r000e:ev SCENARIOS - -- ' Subbasin are: Bastn '1 .i r Designate as Bypass forPOC ''= ; �r -- Surface Interflaw Groundwater • Mitigated ».__.___ ._—_ _ _ .___ .-.; _- -___----•--.._._-_ Area in Basin is thaw Only Seiectedi 14-0 soenor►o - f Available_ Pervious _ Available Impervious - F! FfMMt FNTS 5ei e f.c. esf.Rod L :v' F Oi='FC3PS FLAT ' in r�rwi gqiiitim.E1 i---.. Emu iiw. __ . __ Di.-., . . ._ . _____ mow EJnenit: 41 RsrviousTota 0 A_ acres Impervious Total C.il'2B 1 Acres AL 1110" - - — BasinTotal ar 02B __ _ 1°cres Savexy Ladxv 4 >I i �^ Deselect Zero Select BY- GO I L r`!N:gM3 d^c*e.-.ay2 s, "..,_- %e Ee. View He!. lla' ® a 1Lflk1J1101 IN ' $ :testa I Mingai d SCENARIOS f• ` - 1' Subbasin Name: Pam 1 fl Designate au Bypass for P©C. 1; r Predeveloped I Surface [rrtarilaw Groundwater 31;;: 1 Flows To : 1 J ____ 1, Area in Basin r ShowOnivSetected Run Scana j na ; Available Pervious Available Impervious FF FMFNT? 'W C,Fares tFlei - ; ID FI_Rt}OFTOPSFLAT-- . r __. mat , 'j yz,r• DR11EWAYSJ1 AT �Q28 lem aWill'%:::: ii ; ..R._ -...--- Wr-H4.- i':' , lig'ILQ . °E3 ii, ,I' it' . r i .P Ili.1' ;j l Move Elements 1 1 tisI PerviousToia Acres impervious Tote; 0,1328 Acres r'f Basin Toted :128_ JAcres r .� savexyI LoadXy d ►a � • Y t2 i L Deselect Zero Select BY: r0 ..d.._.�__��_._.,..• ....__..._•-- -__._----..__...__ Wei te 'n Washington Hydrology Model PROJECT REPORT Project Name: driveway2 Site Address City • Report Date : 9/28/2017 Gage Burlington f8.ta Start 1948/10/01 Data End : 1999/09/30 Precip Scale : 0 ., 83 WWEM3 Version: PREDEVELOPED LAND USE Name Driveway Bypass: No Groond ate:c: No Pervious Land Use Acres C, Forest, Flat . 028 I pervious Land Use Acres E 1 Amen t Flows TO: Surface Interflow Groundwater ci,=,nne Basin I Bypass: No GroundWater: No Pervious Land Use Acres Impervious Land Use Acres DRIVEWAYS FLAT 0 . 028 Element Flows To: Surface Interfiow Groundwater MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC 41. Return Period Flow(ofs) 2 year 0.000279 5 year 0.000584 10 year 0.000815 25 year 0.001122 50 year 0. 001353 100 year 0. 00158 Flow Frequency Return Periods for Mitigated. POC (dl Return Period Flow(ofs) 2 year 0. 006393 5 year 0. 008842 10 year 0. 010627 25 year 0.013072 50 year 0.015036 100 year 0.017125 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.001 0. 008 1951 0.001 0.006 1952 0.000 0.007 1953 0.000 0.007 1954 0.000 0.008 1955 0. 000 0.006 1956 0.000 0.004 1957 0.000 0.004 1958 0.000 0.008 1959 0.000 0.006 1960 0.001 0.004 1961 0.000 0.008 1962 0.000 0.005 1963 0.000 0.008 1964 0.000 0.004 1965 0.000 0.008 1966 0.000 0.017 1967 0.000 0.005 1968 0.000 0.012 1969 0.001 0.010 1970 0.000 0.004 1971. 0.000 0.012 1972 0.001 0 .007 1973 0.000 0.005 1974 0.000 0.006 1975 0.001 0.006 1976 0.002 0.012. 1977 0.000 0. 009 1978 0.000 0.005 1979 0.000 0. 010 1980 0.000 0.005 1981 0.000 0.007 1982 0. 000 0.005 1983 0. 001 0.006 1984 0.000 0..005 1985 0.001 0.007 1986 0.000 0. 007 1987 0.000 0.005 1988 0.000 0.004 1989 0.001 0. 011 1990 0.000 0. 006 1991 0.000 0. 007 1992 0.001 0. 010 1993 0.000 0. 006 1994 0.000 0.004 1995 0.000 0.005 1996 0.000 0.005 1997 0.000 0.008 1998 0.001 0.014 1999 0.000 0.007 2000 0.000 0.004 Ranked Yearly Peaks for ?redeveloped and Mitigated. POC #1 Rank ?redeveloped Mitigated 1 0.0024 0.0174 2 0.0011 0.0144 3 0.0010 0.0125 4 0.0009 0.0122 5 0.0007 0.0116 6 0.0007 0.0108 7 0,0007 0.0103 8 0.0006 0.0102 9 0.0006 0.0098 10 0.0006 0.0088 11 0.0006 0.0084 1 12 0.0006 0.0084 13 0.0005 0.0081 14 0.0005 0.0080 15 0.0004 0.0077 16 0.0004 0.0076 17 0.0004 0.0075 18 0.0003 0.0072 19 0.0003 0.0072 20 0.0003 0.0072 21 0.0003 0.0070 22 0.0003 0.0069 23 0.0003 0.0067 24 0.0003 0.0067 25 0.0003 0.0066 26 0.0003 0.0064 27 0.0003 0.0062 28 0.0003 0.0061 29 0.0003 0.0060 30 0.0002 0. 0058 31 0.0002 0. 0056 32 0.0002 0.0055 33 0.0002 0.0055 34 0.0002 0.0055 35 0.0002 0.0054 36 0.0002 0.0053 37 0.0002 0.0052 38 0.0002 0.0052 39 0.0002 0.0050 40 0. 0002 0.0049 41 0. 0001 0.0047 42 0.0001 0.0047 43 0.0001 0.0046 44 0.0001 0.0044 45 0.0001 0.0041 46 0.0001 0.0040 47 0.0001 0.0039 48 0.0001 0.0039 49 0.0000 0.0039 50 0.0000 0.0039 51 0.0000 0.0038 POC #1 Facility duration standard for 1+ flows. Flow(CFS) Predev Dev Percentage Pass/Fail 0.0001 4538 36765 810 0.0002 3991 35393 886 0.0002 3462 34154 986 0.0002 3061 33225 1085 0.0002 2733 32281 1181 0.0002 2468 31334 1269 0.0002 2212 30350 1372 0.0002 2005 29487 1470 0.0002 1821 28647 1573 0.0002 1654 27838 1683 0.0003 1490 27078 1817 0.0003 1365 26465 1938 0.0003 1243 25884 2082 0.0003 1118 25379 2270 0.0003 1025 24780 2417 0.0003 930 24234 2605 0.0003 857 23702 2765 0.0003 798 23211 2908 0.0004 744 22710 3052 0.0004 696 22223 3192 0.0004 646 21780 3371 0.0004 602 21311 3540 0.0004 554 20788 3752 0.0004 510 20332 3986 0.0004 475 19925 4194 0.0004 439 19473 4435 0.0005 401 18959 4727 0.0005 371 18584 5009 0.0005 346 18280 5283 0.0005 325 17918 5513 0.0005 307 17569 5722 0.0005 291 17265 5932 0.0005 273 16903 6191 0.0005 247 16568 6707 0.0006 220 16255 7388 0.0006 200 15955 7977 0.0006 187 15678 8383 0.0006 172 15392 8948 0.0006 158 15106 9560 0.0006 152 14829 9755 0.0006 142 14578 10266 0.0006 134 14270 10649 0.0007 128 14037 10966 0.0007 123 13791 11212 0.0007 116 13546 11677 0.0007 112 13291 11866 0.0007 105 13036 12415 0.0007 100 12795 12795 0.0007 94 12540 13340 0.0007 90 12258 13620 0.0008 89 12084 13577 0.0008 86 11883 13817 0.0008 86 11641 13536 0.0008 82 11386 13885 r 0.0008 78 11149 14293 0.0008 75 10957 14609 0.0008 74 10756 14535 0.0008 72 10577 14690 0.0009 69 10407 15082 . 0.0009 67 10246 15292 0.0009 64 10085 15757 i .: ) ; 0.0009 60 9893 16488 Fail 0.0009 60 9710 16183 Fail 0.0009 58 9500 16379 r ii 0.0009 56 9330 16660 Fail 0.0009 54 9133 16912 F,i.i1 0.0009 53 8941 16869 Fri i l 0.0010 51 8816 17286 Fail 0.0010 50 8686 17372 Fail 0.0010 48 8588 17891 Fail 0.0010 47 8472 18025 Fail 0.0010 46 8351 18154 Fail 0.0010 43 8221 19118 Fa.i 1 0.0010 43 8114 18869 Fail 0.0010 41 8002 19517 rail 0.0011 39 7908 20276 Fail 0.0011 39 7792 19979 E'-)il 0.0011 38 7667 20176 11 0.0011 38 7586 19963 r i1 0.0011 38 7488 19705 Pail 0.0011 37 7403 20008 wail 0.0011 37 7327 19802 Nail 0.0011 37 7233 19548 Fail 0.0012 36 7157 19880 Fail 0.0012 36 7023 19508 Eail. 0.0012 35 6938 19822 0.0012 35 6840 19542 1 0.0012 34 6750 19852 0.0012 33 6665 20196 0.0012 33 6576 19927 0.0012 32 6509 20340 0.0013 31 6420 20709 0 0013 31 6317 20377 0 . 0013 31 6227 20087 0 . 0013 30 6156 20520 0 . 0013 30 6084 20280 0 . 0013 29 6013 20734 0 . 0013 27 5937 21988 0 . 0013 27 5874 21755 0 . 0014 26 5816 22369 The development has an increase in flow durations from 1/2 predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. Water Quality MP Flow and volume for POC 1. On-line facility volume: 0 acre-feet On-line facility target floes: 0 ofs, Adjusted for 15 min: 0 ofs. Off-line facility target flow: 0 cfs . Ad usted for 15 min: 0 cfs. Perind and I pind Change. No changes have been made . This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages SIDEWALK-WWHITM VIEWS.AND REPORT P:1Projects4170201DOCS\Drainage Memo 10.19.17.doc 9 1 WWI-1M 3 Sidewalk - . )3:1: Edit Vievtt Help I M I I liSitilPi Ln]M el - L.11VeAray Pt edevelopeV SCENARIOS 1,! I j I, Subbasin Name- Dnveway •... ..,:, 1 i)1 : F. ci sve lo p 0 II — Surface Interflow Groundwater _77 II, Flows To . [— - ' . 1 ,.._ 7 . . k-F. Mrhgated Area in Basin 11 Show Only Selected Run Sceneno - t 1 : Available Pervious Available Impervious t 1 P I FM F NTS i,', 1..; , i4" C Forest. 1ett -. .... .. .. . lit IV ROOF TOPS FLAT I ,0 - i 1- 011PP 1 ,... 1 J, 1 . R. DRWEWAYS FLAT • [0_ : ,1, , ., . gre.,a•- a 1 ,•• - ••• ; 1---e- ,01p iii ' ,„ II ( 1 , , ,1 Move Elements ! I till __ , PerviousTota VW71 __ i Acres Impervious Total Acres • -- ipr-t.-----: I Basin Total 112011 Acres •,. • II Slave xy _'l Load xY! :,:•:::..t.-•-'2_. .:".:-'":":7.7..""............- -. -.- :--- - - i Deselect Zero Select BY: ' GO ..._.—- 414 bN 411 up Ir-ie) 1 WWHM3 Side-wslIc 'Ile Edit View IleIv: J 0 if: a ..• - 7 71 _ — ,.....— 1 Mb hb...... , -- I willig 1111: 11.1:14k.‘11111111141 ' - I I .11. L..t....___ jL__- ...E.. 44.11 • - ...............___ .,, ., fAraoate.ci lalleitairt. F-..•=1.DE MAR OS I —I Subbasin Name: 1,Basin 1 I I Designate as Bypas_s for POC. liar?redeveloped Surface Interflow Groundwater -- - Flows To : • = ...___. ____.; 7:7:- Fo'1.Yill3gMleti , — —1 , Area in Basin I Show Only Selected = Available Pervious Available Impervious .. _ .._— ___.7 II y"7 4,11- NB,Forest Fjat C ROADS/FLAT -- :6-F F .,_..,. • _._. .._____. _ .. . .. ill.. . 1,-- A/E.Forest Mod • n ROADS/MOD ki ._.. .. . . _._.. = 111&,1 1 ;"" A/8,Forest Steep 1 0 -forid15EEf)-- -- - rO--- '-----"" -- . ...._ . ..__...._. . ._ .. .______ ...._ . . .. . . . - 19V7 NB,Pasture Rat 1..i .,7 Roo -fop.§FCA----t. I--.:41=?El,Pasture,Mod _ ; 14- DRIVEWAYS FIAT ;,,, iiiii.... . ... ..„ ..... _. . _ I . •. -6;6,Pasture,Steep - - •-- - - DRWEWAYS/MOD ,10 - DPNEWAYSISTEEP D DirmA ,1 1 ___ __ .... _.. .... . Na L _ awn,Mod • l', , v.; SIEDEW/qRS/FLAT -- 1 • NE. Lawn.Steep - 0 - SID---EifALXS/MOD !0 , iVi. C,Forest Flat _1— I-' - SIDEWALKS/STEEP ,0 _____ ____ _.. . _........ • i - C Forest Mod r .17-1.-A,FikNG/FLA--r7 to --, O,Forest Steep r -- 15.06sRKN /1,Abb .._._ . C.Pasture,Flat 1.] - PAP:1<1NO/§TEE15 ... If .---. --— --- — .... _ . ... .. __.._. _. . .. ._ _ • C,Peisture,Mod i i . , POND _ _ b ._....._...__ ... . _._ .._... _ .. . • -6,-I3re astu Ste--eo- 0 . .._._ . .... ._. ,,..,! --- --- - - ------- - - — C,Lawn,FIat 0...... _ _ _ . C,Lawn,Mod •-I — Move Elements I - - - " .- - " - - -,- v: C,Lawn.Steep • ,••• . ----1 (011 411 040.7i ,- ____, PerviousTota : --- _ . .__ Acres Impervious 7-otal 1-f.-.)--- ----------- Acres ... _ Basin Total 10.011 I Acres ? Save xy I Load xyi 4 1 1 %< 1.4ti- • I Y 112 . ---n..7.: __-_. .).._I Deselect Zero Select By: GO _ _. .._ _ _._ •• ___ __._ _ _ . 1 jim- la Pir 1 or , Tlig 0 1711 P alb . - --- ------•-- I ri•p.ms S dewa !Ile EditViewHeil:" - - . - - - - -- i 441 imb Ea 1111 MIT1_La = ID � 501 POC1 Predeveloped$ �'. '10 3'=eruan�y tac�i ` 10E 1 1, J 801 POC1 Mtgeted flow i i='io.:(CPS) ?redeveloped E•L siga ed `"- ' I'2 Year a 0 .0001 0 .0025 PS "ear a 0 .0002 0.0035 :0. Year . 0.0003 0. 0042 125 :eas a 0.0004 0.0331 10E 0 _ Year - .0005 .3 35 9 .- ._ 150 0 0 _00 Yeir • 0.0006 0. 3067 {Nearly Peaks =- �� i' :949 0.0004 0.003_' - � 1950 0.0002 0.0023 .. 11951 0.0002 0 .0328 _ !h 1932 0.0001 0 .0026 _�J G 1953 0.0001 0.0032 10E-2 _ 1954 0.0001 0 .0022 .. . � 1055 0 DOOy 0.0015 --- .•- 1 10 20 30 40 50 80 70 80 90 99 i;i; Cumulative Probability - �� 1s56 .3031 0.0015 r,�A°°eaAA°°". ii 1957 0.0002 0.0033 :1 1938 0.0001 0.0323 Durations Flow Frequency__ water Quality M ro r h j Wetland Fluctuation i �1 ., .0002 0.0016 _-_ -_ Yd 9 ap _ 193 9 ^ t ?; 1950 0.0001 0. 0033 _ Analyze daitnsets 19610 .0001 0.0019 -.. ii. ..i tl i' 1962 0.0000 0.0030 - ;i 1963 0 .0001 0.0015 _ I; 19664 0.0001 0.0030 ii 1955 0. 0002 0.0068 Ii 1966 0.0000 0. 0019 ii 1967 0. 0001 0.0048 ii 1968 0.0002 0.0039 f- i 1969 0.0001 0.0015 i Acres All Datasets Flo+ro Stnge- Preap; Evap POC 1 '. 1970 0.0000 0049 :97: 0 .0003 0026 Flood Frequen�r Method it 1972 0 . 3001 3.0018 ii. Log Pearson Type III 178 ' 1973 0.0001 0.0022 c- Weibull , -,c?d :� non, n nn,9 ( Cunnane c er . ._....__ --- -- - - - ... i Western Washington Hydrology Model PROJECT REPORT Project Name: Sidewalk Site Address : City Report Date : 10/19/2017 Gage Burlington Data Start 1948/10/01 Data End 1999/09/30 Precip Scale: 0 . 83 WWH1M3 Version: PREDEVELOPED LAND USE Name Driveway Bypass : No Groundwater: No Pervious Land Use Acres C, Forest, Flat . 011 Impervious Land Use Acres Element Flows To: Surface Interflow Groundwater Name Basin 1 Bypass : No Groundwater: No Pervious Land Use Acres Impervious Land Use Acres SIDEWALKS FLAT 0.011 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.00011 5 year 0.000229 10 year 0.00032 25 year 0.000441 50 year 0.000531 100 year 0.000621 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(ofs) 2 year 0.002512 5 year 0.003474 10 year 0.004175 25 year 0.005135 50 year 0.005907 100 year 0,006728 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.000 0.003 1951 0.000 0.002 1952 0.000 0.003 1953 0.000 0.003 1954 0.000 0.003 1955 0.000 0. 002 1956 0.000 0.002 1957 0.000 0.002 1958 0.000 0.003 1959 0.000 0.002 1960 0.000 0,002 1961 0.000 0.003 1962 0.000 0.002 1963 0.000 0.003 1964 0.000 0.002 1965 0.000 0.003 1966 0.000 0.007 1967 0.000 0.002 1968 0.000 0.005 1969 0.000 0.004 1970 0.000 0.002 1971 0.000 0.005 1972 0.000 0.003 1973 0.000 0.002 1974 0.000 0.002 1975 0.000 0.002 1976 0.001 0.005 1977 0.000 0.003 1978 0.000 0. 002 1979 0. 000 0. 004 1980 0. 000 0.002 1981 0.000 0.003 1982 0.000 0.002 1983 0.000 0.002 1984 0.000 0.002 1985 0.000 0.003 1986 0. 000 0.003 1987 0.000 0.002 1988 0.000 0.002 1989 0.000 0.004 1990 0.000 0.002 1991 0.000 0.003 1992 0.000 0.004 1993 0.000 0.002 1994 0.000 0.002 1995 0.000 0.002 1996 0.000 0.002 1997 0. 000 0.003 1998 0.000 0.006 1999 0.000 0.003 2000 0.000 0.001 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0010 0.0068 2 0.0004 0.0056 3 0.0004 0.0049 4 0.0003 0.0048 5 0.0003 0.0045 6 0.0003 0.0043 7 0.0003 0.0040 8 0.0002 0.0040 9 0.0002 0.0039 10 0.0002 0.0035 11 0.0002 0.0033 12 0.0002 0.0033 13 0.0002 0.0032 14 0.0002 0.0031 15 0.0002 0.0030 16 0.0002 0.0030 17 0.0002 0.0030 18 0.0001 0.0028 19 0.0001 0.0028 20 0.0001 0.0028 21 0.0001 0.0027 22 0.0001 0.0027 23 0.0001 0.0026 24 0.0001 0.0026 25 0.0001 0.0026 26 0.0001 0.0025 27 0.0001 0.0024 28 0.0001 0.0024 29 0.0001 0.0023 30 0.0001 0.0023 31 0.0001 0.0022 32 0.0001 0.0022 33 0.0001 0.0022 34 0.0001 0.0022 35 0.0001 0.0021 36 0.0001 0.0021 37 0.0001 0.0020 38 0.0001 0.0020 39 0.0001 0.0019 40 0.0001 0.0019 41 0.0001 0.0018 42 0.0001 0.0018 43 0.0001 0.0018 44 0.0001 0.0017 45 0.0000 0.0016 46 0.0000 0.0016 47 0.0000 0.0015 48 0.0000 0.0015 49 0.0000 0.0015 50 0.0000 0.0015 51 0.0000 0.0015 POC #1 Facility duration standard for 1+ flows. Flow(CFS) Predev Dev Percentage Pass/Fail 0.0001 4488 36649 816 0.0001 4018 35496 883 rail 0.0001 3498 34253 979 Fail 0.0001 3071 33247 1082 Fail 0.0001 2725 32259 1183 Fail 0.0001 2442 31262 1280 Fail 0.0001 2242 30480 1359 Fail 0.0001 2020 29568 1463 Fail 0.0001 1827 28665 1568 Fail 0.0001 1648 27797 1686 Fail 0.0001 1487 27069 1820 Fail 0.0001 1383 26532 1918 Fail 0.0001 1252 25929 2071 Fail 0.0001 1120 25392 2267 Fail 0.0001 1030 24798 2407 Fail 0.0001 926 24221 2615 Fail 0.0001 864 23774 2751 Fail 0.0001 798 23242 2912 Fail 0.0001 748 22750 3041 Fail 0.0001 697 22236 3190 Fail 0.0002 643 21771 3385 Fail 0.0002 610 21369 3503 Fail 0.0002 560 20886 3729 Fail 0.0002 513 20368 3970 Fail 0.0002 476 19938 4188 Fail 0.0002 438 19460 4442 Fail 0. 0002 401 18950 4725 Fail 0. 0002 375 18628 4967 Fail 0.0002 346 18311 5292 Fail 0.0002 326 17922 5497 Fail 0.0002 308 17578 5707 Fail 0.0002 291 17261 5931 Fail 0.0002 274 16943 6183 Fail 0.0002 251 16612 6618 Fail 0.0002 227 16286 7174 Fail I 0.0002 200 15964 7982 Fail 0.0002 186 15665 8422 Fail 0.0002 174 15459 8884 Fail 0. 0002 159 15137 9520 Fail 0.0002 152 14851 9770 Fail 0.0002 142 14587 10272 Fail 0.0003 134 14279 10655 Fail 0.0003 130 14086 10835 Fail 0.0003 123 13827 11241 Fail 0.0003 117 13568 11596 Fail 0.0003 113 13313 11781 Fail 0.0003 105 13045 12423 Fail 0.0003 101 12839 12711 Fail 0.0003 95 12567 13228 Fail 0.0003 91 12303 13519 Fail 0.0003 89 12097 13592 Fail 0.0003 87 11891 13667 Fail 0.0003 86 11637 13531 Fail 0.0003 82 11440 13951 Fail 0.0003 80 11185 13981 Fail 0.0003 75 10979 14638 Fail 0.0003 74 10760 14540 Fail 0.0003 72 10582 14697 Fail 0.0003 71 10443 14708 Fail 0.0003 67 10264 15319 Fail 0.0003 64 10099 15779 "ai1 0.0003 60 9911 16518 Fail 0.0004 60 9714 16189 Fail. 0.0004 58 9536 16441 Fail 0. 0004 57 9343 16391 Fail 0.0004 55 9160 16654 bail 0.0004 53 8959 16903 Vail 0.0004 51 8820 17294 Fail 0.0004 50 8717 17434 Fail. 0.0004 49 8606 17563 Fail 0.0004 47 8485 18053 Fail 0.0004 46 8369 18193 Fail. 0.0004 43 8235 19151 Fail 0.0004 43 8145 18941 Fail 0.0004 41 8029 19582 rail 0.0004 39 7926 20323 Fail 0.0004 39 7810 20025 Fail 0.0004 38 7676 20200 Fail 0.0004 38 7586 19963 Fail 0.0004 38 7501 19739 Fail 0.0004 37 7421 20056 Fail 0.0004 37 7336 19827 Fail 0.0004 37 7238 19562 Fail 0.0005 36 7162 19894 Fail 0.0005 36 7050 19583 Fail 0.0005 35 6956 19874 Fail 0.0005 35 6853 19580 Fail 0.0005 34 6759 19879 Fail. 0.0005 33 6670 20212 Fail 0.0005 33 6607 20021 Pail 0.0005 32 6522 20381 Fail 0.0005 32 6429 20090 Fail 1 0 . 0005 31 6339 20448 0 . 0005 31 6236 20116 0 . 0005 31 6178 19929 0 . 0005 30 6098 20326 0 . 0005 30 6022 20073 0 . 0005 27 5946 22022 0 . 0005 27 5883 21788 0 . 0005 26 5816 22369 The development has an increase in flow durations from 1/2 predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. Water Quality EYL1 Flow and Volume for IOC 1. On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Perind and Impind Changes No changes have been made . This program and accompanying documentation is provided 'as-is ' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages. OCT � 720i1 li 11 tr, ; 1 LANDE L hj L.,. CITY OF AI IACOHTES G E N T R Y HOMES AND COMMUNITIES I , I LANDED GENTRY 504 East Fairhaven Avenue Burlington, WA 98233 (360) 755-9021 Transmittal Sheet To: Groc Fyrrce From: Steve Baughn Re: 2202 15th Street—BLD-2017-0349 Date: October 26,2017 Planning,Community&Economic Dev. CC: ❑ Urgent ❑For Review ❑ Please Comment D Please Reply 0 Please Recycle Attention: Kait Nelson Re: Responses to the email from Kait Nelson to Groc Fyrrce dated October 11, 2017, regarding the above reference project. 1. Kait Nelson stated: The "hnpervious Coverage" breakdown should be hard surfaces in general. The building is showing the footprint instead of the roof coverage, which would be incorrect. Response: All the information was presented on the plan. However, I have revised the presentation in hopes of making it a little clearer. I now include the roof area in the tabulation but reduced the areas of the remaining hard surfaces because they are covered or partially covered under the roof and eaves. Continued from item 1: In addition to that, the Public Works Department is requiring street improvements. While off-site, those improvements are considered a common plan of development with this lot. The square footage of those improvements must be included with the hard surface breakdown and will count towards the threshold to determine minimum requirements. If the total hard surface area exceeds 5,000 sq. ft., then minimum requirements 1-9 will be required. Response: The "STORM DRAINAGE MEMO", prepared by Ravnik & Associates, Inc., dated September 29, 2017, and revised October 26, 2017, addresses this in detail. • Stormwater facilities are not labeled on site plan with BMP title. The infiltration trench would be BMP T7.20 Infiltration Trench and driveway dispersion would be BMP T5.12 Sheet Flow Dispersion, if those are the intended methods. Response: The two BMP references T7.20 &. T5.12 have been added to the Erosion Control Plan. • The DOE stormwater manuals states as "guidance" that infiltration trenches be at least 20 feet from any uphill foundations, and at least 100 feet from any downhill foundations. Can the engineer confirm that the location of the infiltration trench will not have a significant negative impact on surrounding foundations? Please provide a signed memo. See signed memo from Geotest, dated October 24, 2017, attached. List of items included with this transmittal: (2) Revised Erosion Control Plan sheets 1 of 2 and 2 of 2,both full sized and reduced. (2) Storm Drainage Memo, dated September 29, 2017, amended October 26, 2017, by Ravnik&Associates, Inc. (2) Memo from Geotest, dated October 24, 2017. (2) Frontage Improvement Plans by Herrigstad Engineering & Surveying, dated October 17, 2017. TY . .1Gt.. offof ;,; a" DEPARTMENT OF PLANNING, COMMUNITY & ECONOMIC DEVELOPMENT DATE: August 31, 2017 TO: Groc Fyrrce Building Inspector .. Permit Technician FROM: Kait Nelson Associate Planner PCED SUBJECT: 2202 15th Street, BLD-2017-0349; Stormwater Plan Review Several revisions are necessary to complete the stormwater review: • A soils analysis is necessary to determine the feasibility of infiltration facilities on site. During the dry season(April 1 —October 1), a qualified professional is required to conduct the soils analysis, per the manual. Provide a narrative describing how facilities were chosen,including infeasibility criteria for preferred methods. It may be that something like a raingarden, as proposed,will not work. • To allow a raingarden, a minimum infiltration rate of no less than .30 in/hour is preferred. A minimum separation of one foot is required between the raingarden and the high water table,per the manual. While other options are available as shown in the Raingarden Manual,the city has determined that in order to ensure the raingardens work as needed, this is the minimum standard. • The BMP standards attached to the SWPPP are from the 2005 manual. Please use the 2012 manual for all BMPs,as the specifics have changed. You do not need to resubmit these standards. • There is some discrepancy in the calculations shown on the Erosion Control Plan. The impervious coverage calcs shows the driveway as 737 sf, and the rain garden calcs show the driveway area as 1,236 sf. Where is the difference in these numbers coming from?Please specify how square footage is determined as contributing surfaces towards the raingarden, and why those numbers may be different. • Pervious surface must be proposed for hard surfaces,excluding roofs, if infiltration is no less than.30 in/hour, unless other infeasibility criteria is met. • The design of an infiltration trench that is 6' wide is not a design listed by the DOE's stormwater manual,however, it may be possible with several additional requirements. o Modifications to the infiltration trench design must be done by a qualified engineering professional. o The square footprint must be the same as the square feet requirement determined with a 2' wide design. o The soils and infiltration rate must be verified by a professional. o A header system and multiple perforated pipes must be installed in the trench, i.e. a 6' trench will require a three pipe drain system. o Due to the potential for water mounding, a greater distance from the trench bottom is required. A 6' system will require 5' from the bottom of the trench to the seasonal high water table. These requested revisions may change depending on any improvements requested by the Public Works Department. If you have any questions, feel free to call me at 360.299.1969. Kait Nelson Associate Planner Cricchio, Kevin From: Grage, Libby Sent: Friday, July 7, 2017 4:26 PM To: Ingalls, Paul; Cricchio, Kevin; Nelson, Kait Cc: Measamer, Don; Fyrrce, Groc Subject: 1816 L Ave., P55799 Attachments: 201707071603.pdf Hi everyone, We've had several folks in at the counter over the past few days asking about 1816 L Ave., which is currently for sale (in addition to adjacent parcel P55798, 1820 L Ave.). Questions about the P55799's status as a legal lot have been raised due to its substandard size (<3,000 sq. ft.), and the structure on it, which appears to be nonconforming in terms of setbacks and potentially lot coverage, etc. We have been provided with some chain of title research and deeds (attached) that appear to show that Parcel P55799 was deeded in its current configuration from Ron and Vera Morganthaler to Roger & Betty Morganthaler in 1947. However, it appears that since then, both P55798 and P55799 have again come under the same ownership (Morganthaler Family Trust). According to AMC 19.20.060, the lot must have been in separate ownership and not of continuous frontage with other lots in the same ownership since April 19, 1978 to be considered a legal lot of record. Therefore, it appears that the parcel must be aggregated with the adjacent parcel for purposes of meeting minimum area and dimensional standards. 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J . _.;..� . �..���.rly�C, l�.�i �, ., �..�.�d; ...��.l;i��. �'t�xl�air ;<,.,..�. r��, �.�:;. 3�.,1�:� .���:�'�"�`�` s� rtn:,�'��.�i3„�r'k,�,�'I.'�c:tC` 3 .. .1< Lt ! le 'rit'1 14 k`9.rit 49` [ .°$' l i to "! ' .r x° t� s# ': t r [ - '. ,. t r y :, ,..t r'. ;. pi € c'tig .,. l' ... .: .. ._ . . t _ , � ..... � ���.< i"l a.� ���.,,.. r1 � tl=� ,�..r',r. 1 � �.�= 1�=��1.>�.,l�l`t s� ,.tootai :tad #n dti,. 0ai_. #Ol J.still:tz st iste ._. :s.€. a[tt a rd " rc if.e a greg a.$+' .a sll�i6fa iqy dweltiry . ......n .Lu wxa_ly oy nsey budi'inas rn v e erected thereon for other u es generally riev :'t t d n t rte ,Oremded tb& . lot co.e''ra ,and a other e irertie is ane met.No.portion!of:lard or loti thus ggr'eg to may 'E ;•:e c old in. manner.ner w rl:h .,reate'w re7,:nromns 5fy `an ar •lot, Thanks, Libby Grage I Planning, Community & Economic Development Department P.O. Box 547 1904 6th Street I Anacortes, WA 98221 1 360.299.1986 (work) I libbyb@cityofanacortes.orq 1 www.cityofanacortes.orq My incoming and outgoing email messages are subject to public disclosure requirements per RCW 42.56. From: Debbie Macy [mailto:debbiemacy@windermere.com] Sent:Wednesday,July 05, 2017 9:26 AM To: Measamer, Don<don@cityofanacortes.org> Cc: Grage, Libby<LibbyB@cityofanacortes.org> Subject: RE: Question Thank You Don, Mike & Pat Morgenthaler came down to the city this morning and have filled me in on their conversation with you. Land Title is researching the deeds. Debbie 40, eliati'• Wiry (V' , 360_3 1.2422 ww.i ebbieMac- ,.corn • DebbieN1:tcM.Vinc.1 rmerc.com 1 Cornmcrclal As..'etrn -ATMC rtrA.,Wisk 98221. -Office 36019 3.80f Tali!SO(t31 _32 1-Fax 16412914049 From: Measamer, Don [mailto:don@cityofanacortes.org] Sent: Wednesday,July 5, 2017 9:22 AM To: Debbie Macy<debbiemacyPwindermere.com> Cc:Grage, Libby<LibbyB@cityofanacortes.org> Subject: RE: Question Hi Debbie, My apologies for taking so long to respond to your email, I had a few days off. Based on the assessors office records they appear to be separate lots, however, you will need to consult the title company for a report that goes back prior to 1978, if they are described as two separate lots prior to 1978, through title history, they are legal non-conforming lots. Hope this helps, Don Measamer, Director I Planning, Community& Economic Development Department P.O. Box 547 1904 6th Street I Anacortes, WA 98221 360.299.1942 (work) don@cityofanacortes.org From: Debbie Macy [mailto:debbiemacy@windermere.com] Sent: Friday,June 30, 2017 3:29 PM 2 To: Measamer, Don<don@cityofanacortes.org> Subject: Question Hi Don, I have a property listed and the question has come up pertaining to it being a legal lot. Address is 1816 L Avenue(P55799). It was separated at some point years ago from the adjoining property seller owns at 1820 L Avenue (P55798). What ramifications do we need to be aware of. I realize that 1816 L is a substandard lot. Can someone get a remodel permit as long as they stay within the confines of the existing structure? Thank You- Debbie i. aeg I, 360 91.242 414 �` N4\v�A'v)i)e'3�3ie a ev.com l ze ac IVinder ere.corn 18 C.ornmercial Anaeortes,' 'A 9 22i -Office r .29 800 -Tali 800.327.5291-Fax 360.293.4049 3 i 741 Marine Drive PHONE Bellingham,WA 98225 360 733_7318 Ca OTG 5T 20611-67"Avenue88 251 rax Arlington,WA 98223 223 88 251 5276 360 733 7418 October 24, 2017 1-7 CI 5 Job No. 17-0425 ' U Landed Gentry Homes and Communities OCT 2 7 201 504 East Fairhaven Avenue Burlington, WA 98233 CITY OF ANACORTES Attn.: Steven Baughn Re: Stormwater Infiltration Evaluation Memo Padilla ADU Development 2202 151" Street Anacortes, Washington Dear Mr. Baughn, As requested, GeoTest Services, Inc. (GTS) is pleased to submit this memorandum disusing the effects of stormwater from the proposed infiltration trench on the adjacent residential foundations. It is our understanding that the City of Anacortes Planning Department has concerns that the foundation setback distances from the trench might not meet the suggested guidelines put forth in the 2014 DOE Stormwater Manual for Western Washington and may have 'a significant negative impact on the surrounding foundations'. The manual suggests that infiltration trenches be placed at least 20 feet from uphill foundations and 100 feet away from downhill foundations. The proposed infiltration trench is to be situated 20 feet north of the proposed residence on the subject property and runs east to west for 46 feet. The existing residence on the neighboring property to the north is 48 feet away from the proposed infiltration trench. Topography on the property slopes gently downward to the north, dropping approximately 1 foot in elevation from the trench to the neighboring residence, giving a gradient of 1 degree or 2 percent. Based upon the relatively flat topography and the fact that the upper 4 feet of the existing site soils contain weathered till that can be infiltrated into at a rate of 1.5 inches per hour, in our opinion, it is extremely unlikely that the location of the proposed trench would negatively impact the surrounding foundations. Page 1 of 2 GeoTest Services, Inc. October 24,2017 2202 15eh Street,Anacortes,WA Job No. 17-0425 We appreciate the opportunity to be of service to you on this project. If any questions should arise regarding this report, please contact the undersigned. Respectfully Submitted, GeoTest Services, Inc. o[Wasg*X Ner • 'ij•'t�ry `(! ngi ring Geologist h` ', 0 2420 \op` ,.sed Ge/ Tim Chylla Tim Chylla, L.E.G. Engineering Geologist Attachments Figure 1 Vicinity Map Figure 2 Site Plan References Washington State Department of Ecology, 2012 (amended December 2014). Stormwater Management Manual for Western Washington. Page 2 of 2 PROJECT LOCATION i SSt+ D. t a t. t S 3 I , i .ittl rl }. '1 t 6th St i•• It1,st R °� 4 I 10IhS1 T A1111tS1 Cap )tc;Park (2i) Anacortes U 131A5t L x rr. 1Am5 e 1. 1' D z' b u O c b n ¢ e c t 1a ir nth Volunteer Park I `yrjlbS �° x ; : C o alte ► A ; t v 2�. it aQ o Anacortes Marino A y 7 J' i • D [ < A 1 1 . c 4 a o 2!7 4� r ' Cranber , I ' .1 ;� Anacortes Lake,Pa k to . 28th St .ms _ ; Airport �L0-,s, 6,, n ro I-' 0 V, ) h I t 1, 301A SI u V , ii) /4 ' f 4.',I.i Irt ....) y 4 I I I I� pc% ! 4 �' ✓ u 34th St rip '''.. - r . r♦, q l 35th St ri, D r ! q. I. 361h St G r ., 37th St I Si ?Doiw 4 4s° Z l 4. nthSf Jy F, ,...,iii' `ae ` .�° ' J � t n it*Nor N Ave 1 ,� rI . WIQrreet Or ° � r �,^ a m I ":4 Iti F > + _ . r• fide tgo Ave �I itt e / ,t tg A1`attrrit a lek 0, ' i MAP REFERENCED FROM GOOGLE MAPS . , [!13 1610 rriit it WI ,,ft,q,:i-7 4- I, i , •I`, 2 I 2011 I ri �II OCT a CITY OF ANACORTES M Date: 8-30-17 1 By: JS Scale: As Shown Project 3EOTEST SERVICES, INC. IIC jtt 1)( MAP 7-04 V 741 Marine Drive Bellingham, WA 98225 PADILLA ADU Figure phone: (360) 733-7318 2202 15TH STREET fax: (360) 733 7418 ANACORTES, WASHINGTON 1 / PLANNING, CONINUNITY, &ECONOMIC DEVELOPMENT DEPARTTVIENT v-- ;,. I ES-HblE 1 Q L OL E QINc PERMIT `4QOG� `I=, . H MailingAddr°ess:P.O.Box 547,4.nacor^te 98221 `4'� ' 10 Office Location:904 6t12 Street �lnacortes 9&t,,1 ° 201 Phone: (360)293-1901, Fax: (360)2 3 CITY OF ANACOFRTES PLEASE REFER TO THE RESIDENTIAL BUILDING PERMIT CHECKLIST BELOW FOR SUBMITTAL REQUIREMENTS PROJECT ADDRESStreet,Suite#): Parcel(s)#: _2_0 3_ 15 s— 3 - 2 — o`er - o©a 9 Subdivision/Lot#: Project Valuation: $ $ I APPLICANT: Phone: Fax: .'.Anl0dO ' .e, vi',iy 1)f= vCr.0 y•+.fo.!at e (''" '7 ✓ - D ('%i Address(Street,City,State,Zip): r r g z.D`s E-Mail Address: 5 c, !f C. "" At R_ to f.,v.,u N AV47 B L.%,...e:v:.,c,r4 'vs.,'11 n.r i Cs, { e: rA t:‘,!',[-1 [3(, 0.4 i.t.,l , 6i) PROPERTY OWNER: Phone: Fax: ✓ 4_ e ea XJ o Cr a:,ro7!..'i D G v 31,o -'J 5 5- G:.o�. I Address(Street,City,State,Zip): 'I , 3 B-Mail Address: v, ve,Lt E=: -rr�.�1-eh ,'.- r I ;-' ' 3k..":\6 . 1/v$ J. t-JA r'Srk e `& l?) 1�..., , "_{-tr.,a ,:, V . CONTACT PERSON: Phone: "J Fax: Address(Street,City,State,Zip): r 3 3 3 E-Mail Address: a 6, „E L_ 1F. ti 5 6d V. 1. v'Zy{.r A1('.: ij�.'f..L,t NC. i L;J a 4tiY1.J L- e3 i.r� v Jf . f,o LENDINGAGENCle. Phone: Fax: Address(Street,City,Stl�te,Zip): E-Mail Address. CONTRACTOR:* -� Phone: _ Fax: Address(Street,City, e,Zip): E-Mail Address: Professional License#: Exp.Date: *All Contractors&Subcontractors must have a valid City ofAnacortes 1,y r.�.0 0t>(40 C6 E iy 4 'v._ 5 _ 2..u i 9 business license prior to doing work in the City. Contact the City's Business License#: Exp.Date: Finance Department at(360)299-1968. PROPOSED WORK: Fay: -v N trw 5'12 .Ql A-' ti. Basement SQ': Finished Basement: 0 Unfinished Basement 0 1st Floor SQ': I°VI 5 Garage/Carport SQ': S 55 2nd Floor SQ'• 1 •-43 5 , Deck/Covered Porch!Patio SQ': 16 9 Fire Sprinkler: Yes 0 . No It Lot Area SQ': (of 41-1 5 I declare under penalty of perjury that the information I have provided on this form/application is true,correct,and complete, and that I am the property owner or duly authorized agent of the property owner to submit a permit application to the City of Anacortes. Print Name: Aiv, - Owner I:Agent 0 (specify): Signature: --2f----"A Date: 1/7/1 i 7/ Page 1 of 3 ii 1-0 -- )-vl 7 " 6 3 L�q l / , . Cia,,S" --ic;14--,, —(3 l'te-'0 CI Ap,,,Le., I —j MECI-IANIC ` Equipment Type: Appliance/Equipment Information(new and relocated): Total#: Furnace: Gas#: I Mee#: Other#: ) t—/ Gas Water Heater: #: Location(s): (?;;,N,A,.e,, 2_ C,/ Heat Pump: Elec#: Other it: Air Conditioning: Elec#: Other#: Boiler: Gas#: Elec#: Other#: BTUs: • Exhaust Fans: Bath#: /5-- Laundry#: J Other: ; 9 Range Hood: #: Location(s): k1rci,Gp.i1 L Fireplace: Gas#: I Elec#: Other:#: Location(s): i Clothes Dryer:/Duct: Gas#: Elec#: Other:#: Location(s): IL Stove/Range/Oven: Gas#: Elec#: Other:#: Location(s): _ Range Hood: Location(s): st,i faro-,,s • Gas Outlet(s): #: 5 Location(s): .5 Other: #: Location(s): TOTAL LO .111111=11.11.11 ) o NO nrflUJl�ln�`c�t • Fixture Type(new and relocated): Total#: Fixture Type(new and relocated): Total#: Water Closet(Toilet): L- 'gerator water supply(for water/ice dispenser): r2— "' Kitchen Sink: 2a r ssure Reduction Valve/Pressure Regulator: . Utility Sink: a C/Wat Service Line: i / Tub: 1,-. , ate Piping: --(?5' Hand Sink: (j/..-L913.es Washer: i'Z- , Shower: 3 trfie is Water Heater: Tank-less? Yes 0 No 0 ' Dishwasher: A ackflow Prevention Device: 0 Hose Bib: 3 Cam' TOTAL OUTLETS: i Z TOTAL OUTLETS: 5 . 1 Page 2 of 3 PLANNING, COIV+ I TITY,&ECONOMIC DEVELOPMENT DEPARTMENT AP-1--9. °GZIDDEP\9[ 1/tfl= E MOl f kI© PERMIT ©NE©[' L[lZIr _._.:, Mailing Address:P.O. Box 547,Anacortes, W4 98221 `�' `"�' �' Office Location:904 6th Sheet,Anacortes i/VA 98821 Phone: (360)293-1901, Fax: (360)293-1938 Plans shall be of sufficient clarity to indicate the location,nature,and extent of the work proposed,and conform to the provisions of the adopted International Codes and City Ordinances. PERMIT TYPE: to SUBMITTAL REQUIREMENTS: RI c ® ®• The number indicates the number of n ' n 70 ' n copies for submittal (if appllicable). 1 a P: a F ®' a, Izi c, Residential Building Permit Application 1 1 1 1 1 Site Plan(Drawn to Scale&Surveyed— 2 2 0 2 2 if applicable) Building Plans (Drawn to Scale) 2 2 2 2 2 Reduced Site Plan(11"X 17") 2 , 2 0 1 1 Reduced Floor Plan(11"X 17") 2 2 2 2 1 Structural Calculations (if applicable) 2 2 2 2 2 Energy Code Compliance(shown on plans) Drainage Plan/Small Parcel Stormwater 2 2 2 Plan Landscape Plan ' 2 2 2 GradingPlan/Cut/Fill 2 2 2 Critical Areas Report(if applicable) 1 1 1 1 Geotechnical Report(if applicable) 1 1 1 1 Plan Review Deposit(due upon 1 submittal) 1. Handouts and Standard Details may be found on the City's website at www.cityofanacortes.org or can be obtained at City Hall during normal business hours. 2. PIans/calculation/reports prepared by state licensed architects or professional engineers must be stamped and signed by the design professional. Page 3 of 3 Y o Planning, Community, & Economic Development Department dew. PO Box 547, Anacortes, WA 98221 PH: 360.299.1984 47 13 Elements of SWPPP q�oRs (Construction Stormwater Pollution Prevention Plan) Please check off boxes to show that each element has been read and understood. Provide details where applicable and if certain aspects are unnecessary or exempt, clearly justify. Details of the 13 Elements and the correlating BMPs are listed on Pg. 236 of the 2014 Stormwater Management Manual for Western Washington (SWMMWW).A link is provided on the City of Anacortes website, under Planning, Community, & Economic Development Department, as well as under Stormwater on the Engineering Division of Public Work's page. Owner Name: FIZE(2 l . L l 0 I- 1 JUL 0 'J 2011 Site Address: 2 2.02 +" ST. CITY OF ANACORTES Prepared By: LANDo GE,JT7 f VELCeI'/E )j five. The Stormwater checklist or building permit determined that: ❑ The 13 elements must be addressed for Xr- These elements must be addressed for construction activity adding under 2,000 construction activity adding 2,000 sq.ft. sq.ft. of hard surface area. or more of hard surface area. This means that an attached narrative and site plan are required with this document. Under each element, explain the best management practices (BMPs) used or justify reasoning for those that will not-be-used;if needed,-please attach a narrative-to-further explain plans or justification. ELEMENT 1: Preserve Vegetation/Mark Clearing Limits 0 Before beginning land disturbing activities, including clearing and grading, clearly mark all clearing limits,sensitive areas and their buffers, and trees that are to be preserved within the construction area. ❑ Retain the duff layer, native top soil,and natural vegetation in an undisturbed state to the maximum degree practical. -SS-6 14(ISIT " �`� , E -E.Mstir I Page 1 of 8 March, 2017 ELEMENT 2: Establish Construction Access Cl Limit construction vehicle access and exit to one route, if possible. ❑ Stabilize access points with a pad of quarry spalls,crushed rock, or other equivalent BMPs,to minimize tracking onto roads. ❑ Locate wheel wash or tire baths on site, if the stabilized construction entrance is not effective in preventing tracking sediment onto roads. ❑ If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day, or more frequently as necessary (ex:wet weather). Remove sediment from roads by shoveling, sweeping, or pick up and transport the sediment to a controlled sediment disposal area. ❑ Conduct street washing only after sediment is removed in accordance with the above bullet. ❑ Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tributary to waters of the State. ELEMENT 3: Control Flow Rates ❑ Protect properties and waterways downstream of development sites from erosion and the associated discharge of turbid waters due to increases in the velocity and peak volumetric flow rate of stormwater runoff from the project site. ❑ Where necessary to comply with the bullet above, construct stormwater retention or detention facilities as one of the first steps in grading.Assure that detention facilities function properly before constructing site improvement(e.g. impervious surfaces). Cl If permanent infiltration ponds are used for flow control during construction, protect these facilities from siltation during the construction phase. g-.7c41QJr 6`t Et.c i r .� ELEMENT 4: Install Sediment Controls ❑ Design, install, and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. ❑ Construct sediment control BMPs (sediment ponds,traps,filters, etc.) as one of the first steps in grading.These BMPs shall be functional before other land disturbing activities take place. ❑ Minimize sediment discharges from the site.The design, installation and maintenance of erosion and sediment controls must address factors such as the amount,frequency, intensity and duration of precipitation, the nature of resulting stormwater runoff,and soil characteristics, including the range of soil particle sizes expected to be present on the site. ❑ Direct stormwater runoff from disturbed areas through a sediment pond or other appropriate sediment removal BMP, before the runoff leaves a construction site or before discharge to an Page 2 of 8 March,2017 infiltration facility. Runoff from fully stabilized areas may be discharged without a sediment removal BMP, but must meet the flow control performance standard in Element#3, bullet#1. ❑ Locate BMPs intended to trap sediment on-site in a manner to avoid interference with the movement of juvenile salmonids attempting to enter off-channel areas or drainages. ❑ Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal, and maximize stormwater infiltration. ❑ Where feasible,design outlet structures that withdraw impounded stormwater from the surface to avoid discharging sediment that is still suspended lower in the water column. E.-X;-I e. I T- H 5n r 4 ELEMENT 5: Stabilize Soils ❑ Stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. Applicable BMPs include, but are not limited to:temporary and permanent seeding,sodding, mulching, plastic covering,erosion control fabrics and matting,soil application of polyacrylamide (PAM),the early application of gravel base early on areas to be paved, and dust control. ❑ Control stormwater volume and velocity within the site to minimize soil erosion. ❑ Control stormwater discharges, including both peak flow rates and total stormwater volume,to minimize erosion at outlets and to minimize downstream channel and stream bank erosion. ❑ Soils must not remain exposed and unworked for more than the time periods set forth below to prevent erosion. o During the dry season (May 1—Sept 30): 7 days o During the wet season (Oct 1—Apr 30): 2 days ❑ Stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather forecast. ❑ Stabilize soil stockpiles from erosion, protect with sediment trapping measures,and where possible, be located away from storm drain inlets,waterways, and drainage channels. ❑ Minimize the amount of soil exposed during construction activity. ❑ Minimize the disturbance of steep slopes. ❑ Minimize soil compaction and, unless infeasible, preserve topsoil. FX 1IJ Il,�rl 1-(Ervl&4r 5. ELEMENT 6: Protect Slopes ❑ Design and construct cut-and-fill slopes in a manner to minimize erosion.Applicable practices include, but are not limited to, reducing continuous length of slope with terracing and diversions, reducing slope steepness, and roughening slope surfaces (Ex:track walking). Page 3 of 8 March, 2017 ❑ Divert off-site stormwater(run-on) or ground water away from slopes and disturbed areas with interceptor dikes, pipes, and/or swales. Off-site stormwater should be managed separately from stormwater generated on the site. ❑ At the top of slopes, collect drainage in pipe slop drains or protected channels to prevent erosion. o *Temporary pipe slope drains must handle the peak volumetric flow rate calculated using a 10-minute time step from a Type 1A, 10-year, 24-hour frequency storm for the developed condition.Alternatively,the 10-year, 1-hour flow rate predicted/indicated by an approved continuous runoff model, increased by a factor of 1.6,may be used.The hydrologic analysis must use the existing land cover condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis must use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. If using the Western Washington Hydrology Model (WWHM)to predict flows, bare soil areas should be modeled as "landscaped" area. o Where 15-minute time steps are available in an approved continuous runoff model, they may be used directly without a correction factor. ❑ Place excavated material on the uphill side of trenches,consistent with safety and space considerations. ❑ Place check dams at regular intervals within constructed channels that are cut down a slope. ❑ Consider soil types and its potential for erosion. ❑ Stabilize soils on slopes, as specified in Element 5. ❑ BM P combinations are the most effective method of protecting slopes with disturbed soils. Ex: Use both mulching and straw erosion control blankets. ELEMENT 7: Protect Drain Inlets ❑ Protect all storm drain inlets made operable during construction so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. ❑ Clean or remove and replace inlet protection devices when sediment has filled one-third of the available storage (unless a different standard is specified by the product manufacturer). ❑ Where possible,protect all existing storm drain inlets so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. ❑ Keep all approach roads clean. Do not allow sediment and street wash water to enter storm drains without prior and adequate treatment unless treatment is provided before the storm drain discharges to waters of the State. ❑ Inlets should be inspected weekly at a minimum and daily during storm events. sr /r B`` , Page 4 of 8 March, 2017 ELEMENT 8:Stabilize Channels and Outlets ❑ Design, construct, and stabilize all on-site conveyance channels to prevent erosion from the following expected peak flows: o *Channels must handle same peak volumetric flow rate as temporary pipe slope drains listed in Element 6, above. ❑ Provide stabilization, including armoring material,adequate to prevent erosion of outlets, adjacent streambanks,slopes, and downstream reaches at the outlets of all conveyance systems. ❑ The best method for stabilizing channels is to completely line the channel with a blanket product first,then add check dams as necessary to function as an anchor and to slow the flow of water. ELEMENT 9: Control Pollutants ❑ Design, install, implement,and maintain effective pollution prevention measures to minimize the discharge of pollutants. ❑ Handle and dispose of all pollutants, including waste materials and demolition debris that occur on-site in a manner that does not cause contamination of stormwater. ❑ Provide cover,containment, and protection from vandalism for all chemicals, liquid products, petroleum products, and other materials that have the potential to pose a threat to human health or the environment.On-site fueling tanks must include secondary containment. Secondary containment means placing tanks or containers within an impervious structure capable of containing 110%of the volume contained in the largest tank within the containment structure. Double-walled tanks do not require additional secondary containment. ❑ Conduct maintenance,fueling, and repair of heavy equipment and vehicles using spill prevention and control measures. Clean contaminated surfaces immediately following any spill incident. ❑ Discharge wheel wash or tire bath wastewater to a separate on-site treatment system that prevents discharge to surface water, such as closed-loop recirculation or upland land application, or to the sanitary sewer,with local sewer district approval.Wheel wash or tire bath wastewater should not include wastewater from concrete washout areas. ❑ Apply fertilizers and pesticides in a manner and at application rates that will not result in loss of chemical to stormwater runoff. Follow manufacturers' label requirements for application rates and procedures. ❑ Use BMPs to prevent contamination of stormwater runoff by pH-modifying sources.The sources for this contamination include, but are not limited to: bulk cement,cement kiln dust,fly ash, new concrete washing and curing waters, waste streams generated from concrete grinding and sawing, exposed aggregate processes, dewatering concrete vaults, concrete pumping,and mixer washout waters.Adjust the pH of stormwater if necessary to prevent violations of the water quality standards. Page 5 of 8 March, 2017 ❑ Assure that washout of concrete trucks is performed off-site or in designated concrete washout areas only. Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Do not use upland land applications for discharging wastewater from concrete washout areas. ❑ Obtain written approval from Ecology and provide to the City before using chemical treatment other than CO2 or dry ice to adjust pH. ❑ Woody debris may be chopped and spread on site. ❑ Conduct oil changes, hydraulic system drain down,solvent and de-greasing cleaning operations, fuel tank drain down and removal,and other activities which may result in discharge or spillage of pollutants to the ground or into stormwater runoff using spill prevention measures, such as drip pans. O Clean contaminated surfaces immediately following any discharge or spill incident. Emergency repairs may be performed on-site using temporary plastic placed beneath and, if raining, over the vehicle. ���� ;✓ r3 r7- " �` 1. c�Fr�/EAil i 9 ELEMENT 10: Control De-Watering ❑ Discharge foundation,vault,and trench dewatering water, which have characteristics similar to stormwater runoff at the site, into a controlled conveyance system before discharge to a sediment trap or sediment pond. O Discharge clean, non-turbid de-watering water, such as well-point ground water, to systems tributary to, or directly into surface waters of the State,as specified in Element 8, provided the de-watering flow does not cause erosion or flooding of receiving waters or interfere with the operation of the system. Do not route clean dewatering water through stormwater sediment ponds. Note that"surface waters of the State" may exist on a construction site as well as off site;for example,a creek running through a site. O Handle highly turbid or contaminated dewatering water separately from stormwater. O Other treatment or disposal options may include: 1. Infiltration 2. Transport off-site in a vehicle, such as a vacuum flush truck,for legal disposal in a manner that does not pollute state waters. 3. Ecology-approved on-site chemical treatment or other suitable treatment technologies. 4. Sanitary or combined sewer discharge with local sewer district approval, if there is no other option. 5. Use of a sedimentation bag with outfall to a ditch or swale for small volumes of localized dewatering. ❑ Construction equipment operation,clamshell digging,concrete tremie pour,or work inside a cofferdam can create highly turbid or contaminated dewatering water. O Discharging sediment-laden (muddy)water into waters of the State likely constitutes a violation Page 6 of 8 March, 2017 of water quality standards for turbidity.The easiest way to avoid discharging muddy water is through infiltration and preserving vegetation. ELEMENT 11: Maintain BMPs ❑ Maintain and repair all temporary and permanent erosion and sediment control BMPs as needed to assure continued performance of their intended function in accordance with BMP specifications. ❑ Remove all temporary erosion and sediment control BMPs within 30 days after achieving final site stabilization or after the temporary BMPs are no longer needed. Some temporary erosion and sediment control BMPs are bio-degradable and designed to remain in place following construction such as compost socks. ❑ Provide protection to all BMPs installed for the permanent control of stormwater from sediment and compaction.All BMPs that are to remain in place following completion of construction shall be examined and placed in full operating conditions. If sediment enters the BMPs during construction, it shall be removed and the facility shall be returned to the conditions specified in the construction documents. ❑ Remove or stabilize trapped sediment on site. Permanently stabilize disturbed soil resulting from removal of BMPs or vegetation. ELEMENT 12: Manage the Project— Projects subject to Minimum Requirements 1-9 must have a Certified Erosion and Sediment Control Lead (CESCL)for site inspections. Projects subject to Minimum Requirements 1-5 do not require the inspector to be certified. By the initiation of construction, the SWPPP must identify the CESCL or inspector, who shall be present on-site or on-call at all times. Management details starting on Pg. 250. ❑ Phase development projects to the maximum degree practicable and take into account seasonal work limits to prevent soil erosion and prevent transporting sediment from the site during construction. ❑ Inspection and monitoring—Inspect, maintain,and repair all BMPs as needed to assure continued performance of their intended function. El Maintain, update, and implement the SWPPP. ❑ Clearing and grading activities for developments shall be permitted only if conducted using an approved site development plan (e.g.,subdivision approval). ❑ From Oct 1 through Apr 30,clearing,grading,and other soil disturbing activities is permitted only if shown that the site operator will prevent silt-laden runoff from leaving the site through a combination of the following: Page 7 of 8 March, 2017 1. Site conditions including existing vegetative coverage, slope, soil type, and proximity to receiving waters. 2. Limit activities and the extent of disturbed areas. 3. Proposed erosion and sediment control measures. Weather conditions can influence the seasonal limitation on site disturbance.The City of Anacortes has the authority to take enforcement action per AMC 19.76 Stormwater. ❑ The following activities are exempt from the seasonal clearing and grading limitations: 1. Routine maintenance and necessary repair of erosion and sediment control BMPs; 2. Routine maintenance of public facilities or existing utility structures that do not expose the soil or result in the removal of the vegetative cover to soil 3. Activities where there is 100% infiltration of surface water runoff within the site in approved and installed erosion and sediment control facilities. ELEMENT 13: Protect Low Impact Development BMPS ❑ If implementing any bioretention facilities or rain gardens,see Pg. 253 for requirements. 7 / Applicant Signature D e Page 8 of 8 March, 2017 EXHIBIT "B" Responses to the "13 Elements of SWPPP" (Construction Stormwater Pollution Prevention Plan) ELEMENT 1: Preserve Vegetation/Mark Clearing Limits The clearing limits will be marked by using either BMP C233: Silt Fence, or BMP C103: High Visibility Plastic or Metal Fence, as shown on the Erosion Control Plan. C233 is to be used along the west and north property lines and the C103 along the east and south property lines. Preservation of the native top soil will be preserved as much as is practical by use of a stock pile as shown on the Erosion Control Plan. Stock pile location may vary. Stock pile shall be protected as indicated on the Erosion Control Plan. ELEMENT 2: Establish Construction Access BMP C105 shall be used as the construction access. Only one access point is proposed, however, during construction of the storm drain extension and the sanitary sewer service installation, access along the alley will be necessary. No wheel wash is proposed. Any track out shall be cleaned daily by shoveling and/or sweeping. More frequent cleaning as necessary. ELEMENT 3: Control Flow Rates Flow rates shall be controlled by use of the proposed Rain Garden, installation of the downspout infiltration system, and by the extension of the public drainage system. ELEMENT 4: Install Sediment Controls The following BMPs are proposed as temporary sediment controls: C103: High Visibility Plastic or Metal Fence To be place along the perimeter of the site to mark the clearing limits for the construction crew and to alert the public as to the potential dangers of the ongoing onsite construction activity. C233: Silt Fence To be place along the perimeter of the site to protect downstream properties from the transport of coarse sediment, as well as to mark the clearing limits for the construction crew and to alert the public as to the potential dangers of the ongoing onsite construction activity. C105: Stabilized Construction Entrance To be place in the location of the future driveway on 15th Street, to provide a stable and clean point of access for construction vehicles. C121: Mulching To provide immediate temporary protection of exposed soil from erosion, as well as conserving moisture. C123: Plastic Covering Primarily used to protect the stock pile from erosion. May be used as a short term cover of small areas of exposed soil. Not intended for large areas. C140: Dust Control As this project will be constructed during the dry season, dust control may be necessary to protect the surrounding neighborhood. The primary source of dust control will be controlled spraying of the disturbed area with water. C220: Storm Drain Inlet Protection Onsite inlet protection will use Block& Gravel Curb Inlet Protection. Offsite inlet protection will use Catch Basin Filters manufactured for use at construction sites. C207: Check Dams Where drainage swale are created to convey stormwater, temporary gravel check dams may be used to reduce velocity and to dissipate flow energy. The following BMP and LID improvements are proposed for permanent sediment controls: T5.14A: Rain Gardens A Rain Garden is proposed downstream of the concrete driveway in lieu of the installation of pervious concrete. Installation of the Rain Garden is per the Rain Garden Handbook for Western Washington, A Guide for Design, Installation, and Maintenance. T5.10A: Downspout Full Infiltration A Downspout Infiltration Trench is to be installed per Figure 3.2 of Volume III— Hydrologic Analysis and Flow Control BMP's, modified per detail on Sheet 2 of 2 of the Erosion Control Plan & LID Improvement Plan. ELEMENT 5: Soil Stabilization The following are temporary soil stabilization BMPs: C233: Silt Fence To be place along the perimeter of the site to protect downstream properties from the transport of coarse sediment, as well as to mark the clearing limits for the construction crew and to alert the public as to the potential dangers of the ongoing onsite construction activity. C105: Stabilized Construction Entrance To be place in the location of the future driveway on 15th Street,to provide a stable and clean point of access for construction vehicles. C121: Mulching To provide immediate temporary protection of exposed soil from erosion, as well as conserving moisture. C123: Plastic Covering Primarily used to protect the stock pile from erosion. May be used as a short term cover of small areas of exposed soil. Not intended for large areas. C140: Dust Control As this project will be constructed during the dry season, dust control may be necessary to protect the surrounding neighborhood. The primary source of dust control will be controlled spraying of the disturbed area with water. C220: Storm Drain Inlet Protection Onsite inlet protection will use Block & Gravel Curb Inlet Protection. Offsite inlet protection will use Catch Basin Filters manufactured for use at construction sites. C207: Check Dams Where drainage swale are created to convey stormwater, temporary gravel check dams may be used to reduce velocity and to dissipate flow energy. The following are permanent soil stabilization BMPs: C124: Sodding Establishes permanent turf for immediate erosion protection. C125: Top Soiling Provides a suitable growth medium for final site stabilization with vegetation. T5.13: Post-Construction Soil Quality and Depth Establishes soil quality and depth regains greater stormwater functions in the post development landscape, provides increased treatment of pollutants and sediments that result from development and habitation. ELEMENT 6: Protect Slopes No slopes over 10% on the site. ELEMENT 7: Protect Drain Inlets C220: Storm Drain Inlet Protection Onsite inlet protection will use Block& Gravel Curb Inlet Protection. Offsite inlet protection will use Catch Basin Filters manufactured for use at construction sites. ELEMENT 8: Stabilize Channels and Outlets C207: Check Dams Where drainage swale are created to convey stormwater, temporary gravel check dams may be used to reduce velocity and to dissipate flow energy. ELEMENT 9: Control Pollutants Debris from the demolition of the existing structure (shed) will be placed in a containment bin immediately. No debris shall be stored on site. All fuel, lubricants, paint, and/or other hazardous material shall be stored in a lockable, covered storage container if kept on site. ELEMENT 10: Control De-Watering Test pits were dug to a depth of 7.5 to 8 feet with ground water only appearing at the depths below 7 feet. Therefore, no dewatering is anticipated. ELEMENT 11: Maintain BMPs A trained Certified Erosion and Sedimentation Control Lead (CESCL) will be on the job site. CESCL personnel are trained in and responsible for the proper maintenance of the erosion control BMPs. The CESCL will work with the City of Anacortes Inspector to maintain all BMPs. ELEMENT 12: Manage the Project A trained Certified Erosion and Sedimentation Control Lead (CESCL) will be on the job site. CESCL personnel are trained in and responsible for the proper maintenance of the erosion control BMPs. The CESCL will work with the City of Anacortes Inspector to maintain all BMPs. ELEMENT 13: Protect Low Impact Development BMPs Protect all Rain Garden BMPs from sedimentation through installation and maintenance of erosion and sediment control BMPs on portions of the site that drain into the Rain Garden BMPs. Restore the BMPs to their fully functioning condition if they accumulate sediment during construction. Ill [I FB FL Q' C" PRIMARY BMPs BMP C143: High Visibility Plastic or Metal Fence Purpose Fencing is intended to: (1)restrict clearing to approved limits; (2)prevent disturbance of sensitive areas, their buffers, and other areas required to be left undisturbed; (3) limit construction traffic to designated construction entrances or roads; and, (4)protect areas where marking with survey tape may not provide adequate protection. Conditions of Use To establish clearing limits,plastic or metal fence may be used: • At the boundary of sensitive areas,their buffers, and other areas required to be left uncleared. • As necessary to control vehicle access to and on the site. Design and • High visibility plastic fence shall be composed of a high-density Installation polyethylene material and shall be at least four feet in height. Posts Specifications for the fencing shall be steel or wood and placed every 6 feet on center(maximum) or as needed to ensure rigidity. The fencing shall be fastened to the post every six inches with a polyethylene tie. On long continuous lengths of fencing, a tension wire or rope shall be used as a top stringer to prevent sagging between posts. The fence color shall be high visibility orange. The fence tensile strength shall be 360 lbs./ft. using the ASTM D4595 testing method. • Metal fences shall be designed and installed according to the manufacturer's specifications. • Metal fences shall be at least 3 feet high and must be highly visible. • Fences shall not be wired or stapled to trees. Maintenance • If the fence has been damaged or visibility reduced, it shall be Standards repaired or replaced immediately and visibility restored. 4-6 Volume Il-Construction Stormwater Pollution Prevention February 2005 BMP C105: Stabilized Construction Entrance Purpose Construction entrances are stabilized to reduce the amount of sediment transported onto paved roads by vehicles or equipment by constructing a stabilized pad of quarry spalls at entrances to construction sites. Conditions of Use Construction entrances shall be stabilized wherever traffic will be leaving a construction site and traveling on paved roads or other paved areas within 1,000 feet of the site. On large commercial, highway, and road projects, the designer should include enough extra materials in the contract to allow for additional stabilized entrances not shown in the initial Construction SWPPP. It is difficult to determine exactly where access to these projects will take place; additional materials will enable the contractor to install them where needed. Design and • See Figure 4.2 for details.Note: the 100' minimum length of the Installation entrance shall be reduced to the maximum practicable size when the Specifications size or configuration of the site does not allow the full length(100'). • A separation geotextile shall be placed under the spalls to prevent fine sediment from pumping up into the rock pad. The geotextile shall meet the following standards: Grab Tensile Strength (ASTM D4751) 200 psi min. Grab Tensile Elongation(ASTM D4632) 30%max. Mullen Burst Strength (ASTM D3786-80a) 400 psi min. AOS(ASTM D4751) 20-45(U.S. standard sieve size) • Consider early installation of the first lift of asphalt in areas that will paved; this can be used as a stabilized entrance. Also consider the installation of excess concrete as a stabilized entrance. During large concrete pours, excess concrete is often available for this purpose. • Hog fuel (wood-based mulch)may be substituted for or combined with quarry spalls in areas that will not be used for permanent roads. Hog fuel is generally less effective at stabilizing construction entrances and should be used only at sites where the amount of traffic is very limited. Hog fuel is not recommended for entrance stabilization in urban areas. The effectiveness of hog fuel is highly variable and it generally requires more maintenance than quarry spalls. The inspector may at any time require the use of quany spalls if the hog fuel is not preventing sediment from being tracked onto pavement or if the hog fuel is being carried onto pavement. Hog fuel is prohibited in permanent roadbeds because organics in the subgrade soils cause degradation of the subgrade support over time. • Fencing(see BMPs C103 and C104) shall be installed as necessary to restrict traffic to the construction entrance. 4-8 Volume II— Construction Stormwater Pollution Prevention February 2005 • Whenever possible, the entrance shall be constructed on a firm, compacted subgrade. This can substantially increase the effectiveness of the pad and reduce the need for maintenance. Maintenance m Quarry spalls (or hog fuel) shall be added if the pad is no longer in Standards accordance with the specifications. • If the entrance is not preventing sediment from being tracked onto pavement,then alternative measures to keep the streets free of sediment shall be used. This may include street sweeping, an increase in the dimensions of the entrance, or the installation of a wheel wash. • Any sediment that is tracked onto pavement shall be removed by shoveling or street sweeping. The sediment collected by sweeping shall be removed or stabilized on site. The pavement shall not be cleaned by washing down the street, except when sweeping is ineffective and there is a threat to public safety. If it is necessary to wash the streets, the construction of a small sump shall be considered. The sediment would then be washed into the sump where it can be controlled. • Any quarry spalls that are loosened from the pad, which end up on the roadway shall be removed immediately. • If vehicles are entering or exiting the site at points other than the construction entrance(s), fencing(see BMPs C103 and C104) shall be installed to control traffic. • Upon project completion and site stabilization, all construction accesses intended as permanent access for maintenance shall be permanently stabilized. Driveway shall moot the requirements Oita permitting agency II Is recommended Mel the entrance be crowned so that runoll drama all the pad a Ey\sdo9 o 44464 �� ,- Install driveway culvert ���i4��ram(= II there is a roadside r1���6;,.�i{ ditch present \� �Sj y�, 4"-13"quarry spalls il;:V ;' Geelexllle ��� �%� 12"min.thickness`� N6 .r Provide full width el Ingressregress area Figure 4.2—Stabilized Construction Entrance February 2005 Volume II— Construction Stormwater Pollution Prevention 4-9 { BMP C121: Mulching Purpose The purpose of mulching soils is to provide immediate temporary protection from erosion. Mulch also enhances plant establishment by conserving moisture,holding fertilizer, seed, and topsoil in place, and moderating soil temperatures. There is an enormous variety of mulches that can be used. Only the most common types are discussed in this section. : . Conditions of Use As a temporary cover measure, mulch should be used: • On disturbed areas that require cover measures for less than 30 days. • As a cover for seed during the wet season and during the hot summer months. • During the wet season on slopes steeper than 3H:1V with more than 10 feet of vertical relief. • Mulch may be applied at any time of the year and must be refreshed periodically. Design and For mulch materials, application rates,and specifications, see Table 4.7. Installation Note: Thicknesses may be increased for disturbed areas in or near Specifications sensitive areas or other areas highly susceptible to erosion. 11( Mulch used within the ordinary high-water mark of surface waters should be selected to minimize potential flotation of organic matter. Composted organic materials have higher specific gravities (densities) than straw, wood, or chipped material. Maintenance • The thickness of the cover must be maintained. 111 Standards • Any areas that experience erosion shall be remulched and/or protected with a net or blanket. If the erosion problem is drainage related,then the problem shall be fixed and the eroded area remulched. I I I 4-20 Volume Il— Construction Stormwater Pollution Prevention February 2005 BMP C123: Plastic Covering • Propose Plastic covering provides immediate, short-teen erosion protection to slopes and disturbed areas. Conditions of • Plastic covering may be used on disturbed areas that require cover Use measures for less than 30 days, except as stated below. • Plastic is particularly useful for protecting cut and fill slopes and stockpiles. Note: The relatively rapid breakdown of most polyethylene sheeting makes it unsuitable for long-teen(greater than six months) applications. • Clear plastic sheeting can be used over newly-seeded areas to create a greenhouse effect and encourage grass growth if the hydroseed was installed too late in the season to establish 75 percent grass cover, or if the wet season started earlier than normal. Clear plastic should not be used for this purpose during the summer months because the resulting high temperatures can kill the grass. • Due to rapid runoff caused by plastic sheeting, this method shall not be used upslope of areas that might be adversely impacted by concentrated runoff. Such areas include steep and/or unstable slopes. • While plastic is inexpensive to purchase, the added cost of installation, maintenance, removal, and disposal make this an expensive material, up to $1.50-2.00 per square yard. • Whenever plastic is used to protect slopes,water collection measures must be installed at the base of the slope. These measures include plastic-covered berms, channels, and pipes used to covey clean rainwater away from bare soil and disturbed areas. At no time is clean runoff from a plastic covered slope to be mixed with dirty runoff from a project. • Other uses for plastic include: 1. Temporary ditch liner; 2. Pond liner in temporary sediment pond; 3. Liner for benned temporary fuel storage area if plastic is not reactive to the type of fuel being stored; 4. Emergency slope protection during heavy rains; and, 5. Temporary drainpipe("elephant trunk") used to direct water. 4-26 Volume ll—Construction Stormwater Pollution Prevention February 2005 • Design and • Plastic slope cover must be installed as follows: Installation 1. Run plastic up and down slope, not across slope; Specifications 2. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet; 3. Minimum of 8-inch overlap at seams; 4. On long or wide slopes, or slopes subject to wind, all seams should be taped; 5. Place plastic into a small (12-inch wide by 6-inch deep)slot trench at the top of the slope and backfill with soil to keep water from flowing underneath; 6. Place sand filled burlap or geotextile bags every 3 to 6 feet along seams and pound a wooden stake through each to hold them in place; 7. Inspect plastic for rips, tears, and open seams regularly and repair immediately. This prevents high velocity runoff from contacting bare soil which causes extreme erosion; 8. Sandbags may be lowered into place tied to ropes. However, all sandbags must be staked in place. • Plastic sheeting shall have a minimum thickness of 0.06 millimeters. • If erosion at the toe of a slope is likely, a gravel berm, riprap, or other suitable protection shall be installed at the toe of the slope in order to reduce the velocity of runoff. Maintenance • Torn sheets must be replaced and open seams repaired. Standards • If the plastic begins to deteriorate due to ultraviolet radiation,it must be completely removed and replaced. • When the plastic is no longer needed, it shall be completely removed. • Dispose of old tires appropriately. February 2005 Volume II—Construction Stormwater Pollution Prevention 4-27 111 BMP C124: Sodding Purpose The purpose of sodding is to establish permanent turf for immediate erosion protection and to stabilize drainage ways where concentrated overland flow will occur. Conditions of Use Sodding may be used in the following areas: • Disturbed areas that require short-term or long-term cover. • Disturbed areas that require immediate vegetative cover. • All waterways that require vegetative lining. Waterways may also be seeded rather than sodded, and protected with a net or blanket. Design and Sod shall be free of weeds, of uniform thickness (approximately 1-inch Installation thick), and shall have a dense root mat for mechanical strength. Specifications The following steps are recommended for sod installation: • Shape and smooth the surface to final grade in accordance with the approved grading plan. The swale needs to be overexcavated 4 to 6 inches below design elevation to allow room for placing soil amendment and sod. • Amend 4 inches (minimum) of compost into the top 8 inches of the soil if the organic content of the soil is less than ten percent or the l permeability is less than 0.6 inches per hour. Compost used should meet Ecology publication 94-038 specifications for Grade A quality compost. • Fertilize according to the supplier's recommendations. • Work lime and fertilizer 1 to 2 inches into the soil, and smooth the surface. • Lay strips of sod beginning at the lowest area to be sodded and perpendicular to the direction of water flow. Wedge strips securely into place. Square the ends of each strip to provide for a close, tight fit. Stagger joints at least 12 inches. Staple on slopes steeper than 3H:1 V. Staple the upstream edge of each sod strip. • Roll the sodded area and irrigate. • When sodding is carried out in alternating strips or other patterns, seed the areas between the sod immediately after sodding. Maintenance If the grass is unhealthy, the cause shall be determined and appropriate Standards action taken to reestablish a healthy groundcover. If it is impossible to establish a healthy groundcover due to frequent saturation, instability, or some other cause, the sod shall be removed,the area seeded with an appropriate mix, and protected with a net or blanket. 4-28 Volume ll- Construction Stormwater Pollution Prevention February 2005 • BMP C125: Topsoiling Purpose To provide a suitable growth medium for final site stabilization with vegetation. While not a permanent cover practice in itself, topsoiling is an integral component of providing permanent cover in those areas where there is an unsuitable soil surface for plant growth. Native soils and disturbed soils that have been organically amended not only retain much more stormwater, but they also serve as effective biofilters for urban pollutants and, by supporting more vigorous plant growth, reduce the water, fertilizer and pesticides needed to support installed landscapes. Topsoil does not include any subsoils but only the material from the top several inches including organic debris. Conditions of • Native soils should be left undisturbed to the maximum extent Use practicable. Native soils disturbed during clearing and grading should be restored, to the maximum extent practicable, to a condition where moisture-holding capacity is equal to or better than the original site conditions. This criterion can be met by using on-site native topsoil, incorporating amendments into on-site soil,or importing blended topsoil. • Topsoiling is a required procedure when establishing vegetation on shallow soils, and soils of critically low pH (high acid) levels. • Stripping of existing, properly functioning soil system and vegetation for the purpose of topsoiling during construction is not acceptable. If an existing soil system is functioning properly it shall be preserved in its undisturbed and uncompacted condition. • Depending on where the topsoil comes from, or what vegetation was on site before disturbance, invasive plant seeds may be included and could cause problems for establishing native plants, landscaped areas, or grasses. • Topsoil from the site will contain mycorrhizal bacteria that are necessary for healthy root growth and nutrient transfer. These native mycorrhiza are acclimated to the site and will provide optimum conditions for establishing grasses. Commercially available mycorrhiza products should be used when topsoil is brought in from off-site. Design and If topsoiling is to be done,the following items should be considered: Installation • Maximize the depth of the topsoil wherever possible to provide the Specifications maximum possible infiltration capacity and beneficial growth medium. Topsoil depth shall be at least 8 inches with a minimum organic content of 10 percent dry weight and pH between 6.0 and 8.0 or matching the pH of the undisturbed soil. This can be accomplished either by returning native topsoil to the site and/or incorporating organic amendments. Organic amendments should be incorporated to a minimum 8-inch depth except where tree roots or other natural February 2005 Volume II— Construction Stormwater Pollution Prevention 4-29 J 111 features limit the depth of incorporation. Subsoils below the 12-inch ( depth should be scarified at least 2 inches to avoid stratified layers, where feasible. The decision to either layer topsoil over a subgrade or incorporate topsoil into the underlying layer may vary depending on the planting specified. • If blended topsoil is imported, then fines should be limited to 25 percent passing through a 200 sieve. • The final composition and construction of the soil system will result in a natural selection or favoring of certain plant species over time. For example, recent practices have shown that incorporation of topsoil may favor grasses, while layering with mildly acidic,high-carbon amendments may favor more woody vegetation. • Locate the topsoil stockpile so that it meets specifications and does not interfere with work on the site. It may be possible to locate more than one pile in proximity to areas where topsoil will be used. • Allow sufficient time in scheduling for topsoil to be spread prior to seeding, sodding, or planting. • Care must be taken not to apply to subsoil if the two soils have contrasting textures. Sandy topsoil over clayey subsoil is a particularly poor combination, as water creeps along the junction 0 ( between the soil layers and causes the topsoil to slough. • If topsoil and subsoil are not properly bonded,water will not infiltrate the soil profile evenly and it will be difficult to establish vegetation. The best method to prevent a lack of bonding is to actually work the topsoil into the layer below for a depth of at least 6 inches. • Ripping or re-structuring the subgrade may also provide additional benefits regarding the overall infiltration and interflow dynamics of the soil system. • Field exploration of the site shall be made to determine if there is surface soil of sufficient quantity and quality to justify stripping. Topsoil shall be friable and loamy (loam, sandy loam, silt loam, sandy clay loam, clay loam). Areas of natural ground water recharge should be avoided. • Stripping shall be confined to the immediate construction area. A 4- to 6- inch stripping depth is common, but depth may vary depending on the particular soil. All surface runoff control structures shall be in place prior to stripping. Stockpiling of topsoil shall occur in the following manner: • Side slopes of the stockpile shall not exceed 2:1. • An interceptor dike with gravel outlet and silt fence shall surround all topsoil stockpiles between October 1 and April 30. Between May 1 4-30 Volume 11—Construction Stormwater Pollution Prevention February 2005 i_. and September 30, an interceptor dike with gravel outlet and silt fence shall be installed if the stockpile will remain in place for a longer period of time than active construction grading. • Erosion control seeding or covering with clear plastic or other mulching materials of stockpiles shall be completed within 2 days (October 1 through April 30) or 7 days (May 1 through September 30) of the formation of the stockpile. Native topsoil stockpiles shall not be covered with plastic. • Topsoil shall not be placed while in a frozen or muddy condition, when the subgrade is excessively wet, or when conditions exist that may otherwise be detrimental to proper grading or proposed sodding or seeding. • Previously established grades on the areas to be topsoiled shall be maintained according to the approved plan. • When native topsoil is to be stockpiled and reused the following should apply to ensure that the mycorrhizal bacterial,earthworms, and other beneficial organisms will not be destroyed: 1. Topsoil is to be re-installed within 4 to 6 weeks; 2. Topsoil is not to become saturated with water; 3. Plastic cover is not allowed. Maintenance • Inspect stockpiles regularly, especially after large storm events. Standards Stabilize any areas that have eroded. February 2005 Volume 11— Construction Stormwater Pollution Prevention 4-31 BMP C140: Dust Control Purpose Dust control prevents wind transport of dust from disturbed soil surfaces onto roadways, drainage ways, and surface waters. Conditions of Use • In areas (including roadways)subject to surface and air movement of dust where on-site and off-site impacts to roadways, drainage ways, or surface waters are likely. Design and • Vegetate or mulch areas that will not receive vehicle traffic, In areas Installation where planting,mulching, or paving is impractical, apply gravel or Specifications landscaping rock. • Limit dust generation by clearing only those areas where immediate activity will take place, leaving the remaining area(s)in the original condition, if stable. Maintain the original ground cover as long as practical. • Construct natural or artificial windbreaks or windscreens. These may be designed as enclosures for small dust sources. • Sprinkle the site with water until surface is wet. Repeat as needed. To prevent carryout of mud onto street, refer to Stabilized Construction Entrance(BMP C105). • Irrigation water can be used for dust control. Irrigation systems should be installed as a first step on sites where dust control is a concern. • Spray exposed soil areas with a dust palliative, following the manufacturer's instructions and cautions regarding handling and application. Used oil is prohibited from use as a dust suppressant. Local governments may approve other dust palliatives such as calcium chloride or PAM. • PAM(BMP C126) added to water at a rate of 0.5 lbs. per 1,000 gallons of water per acre and applied from a water truck is more effective than water alone. This is due to the increased infiltration of water into the soil and reduced evaporation. In addition, small soil particles are bonded together and are not as easily transported by wind, Adding PAM may actually reduce the quantity of water needed for dust control, especially in eastern Washington. Since the wholesale cost of PAM is about$ 4.00 per pound, this is an extremely cost- effective dust control method. Techniques that can be used for unpaved roads and lots include: • Lower speed limits. High vehicle speed increases the amount of dust stirred up from unpaved roads and lots. • Upgrade the road surface strength by improving particle size, shape, and mineral types that make up the surface and base materials. 4-40 Volume ll— Construction Stormwater Pollution Prevention February 2005 • Add surface gravel to reduce the source of dust emission. Limit the amount of fine particles (those smaller than .075 mm) to 10 to 20 percent. o Use geotextile fabrics to increase the strength of new roads or roads undergoing reconstruction. ® Encourage the use of alternate,paved routes, if available. • Restrict use by tracked vehicles and heavy trucks to prevent damage to road surface and base. ▪ Apply chemical dust suppressants using the admix method, blending the product with the top few inches of surface material. Suppressants may also be applied as surface treatments. ® Pave unpaved permanent roads and other trafficked areas. • Use vacuum street sweepers. • Remove mud and other dirt promptly so it does not dry and then turn into dust. • Limit dust-causing work on windy days. • Contact your local Air Pollution Control Authority for guidance and training on other dust control measures. Compliance with the local Air Pollution Control Authority constitutes compliance with this BMP. Maintenance Respray area as necessary to keep dust to a minimum. Standards February 2005 Volume II— Construction Stormwater Pollution Prevention 4-41 BMP C160: Certified Erosion and Sediment Control Lead Purpose The project proponent designates at least one person as the responsible representative in charge of erosion and sediment control(ESC), and water quality protection. The designated person shall be the Certified Erosion and Sediment Control Lead (CESCL) who is responsible for ensuring compliance with all local, state, and federal erosion and sediment control and water quality requirements. Conditions of Use A CESCL shall be made available on projects one acre or larger that discharge stormwater to surface waters of the state • The CESCL shall: • Have a current certificate proving attendance in an erosion and sediment control training course that meets the minimum ESC training and certification requirements established by Ecology (see details below). Ecology will maintain a list of ESC training and certification providers at: www.ecy.wa.gov/programs/wq/stormwater. OR • Be a Certified Professional in Erosion and Sediment Control (CPESC); for additional information go to: www.cpesc.net Specifications • Certification shall remain valid for three years. • The CESCL shall have authority to act on behalf of the contractor or developer and shall be available,on call, 24 hours per day throughout the period of construction. • The Construction SWPPP shall include the name, telephone number, fax number, and address of the designated CESCL. • A CESCL may provide inspection and compliance services for multiple construction projects in the same geographic region. Duties and responsibilities of the CESCL shall include,but are not limited to the following: • Maintaining permit file on site at all times which includes the SWPPP and any associated permits and plans. • Directing BMP installation, inspection, maintenance,modification, and removal. • Updating all project drawings and the Construction SWPPP with changes made. February 2005 Volume ll—Construction Stormwater Pollution Prevention 4-47 • Keeping daily logs, and inspection reports. Inspection reports should include: •Inspection date/time. •Weather information; general conditions during inspection and approximate amount of precipitation since the last inspection. •A summary or list of all BMPs implemented, including observations of all erosion/sediment control structures or practices. The following shall be noted: 1)Locations of BMPs inspected, 2) Locations of BMPs that need maintenance, 3)Locations of BMPs that failed to operate as designed or intended, and 4) Locations of where additional or different BMPs are required. •Visual monitoring results, including a description of discharged stoimwater. The presence of suspended sediment, turbid water, discoloration, and oil sheen shall be noted,as applicable. •Any water quality monitoring performed during inspection. •General comments and notes, including a brief description of any BMP repairs, maintenance or installations made as a result of the inspection. • Facilitate,participate in, and take corrective actions resulting from inspections performed by outside agencies or the owner. • 4-48 Volume II—Construction Stormwafor Pollution Prevention February 2005 BMP C207: Check Dams Purpose Construction of small dams across a swale or ditch reduces the velocity of concentrated flow and dissipates energy at the check dam. Conditions of Use Where temporary channels or permanent channels are not yet vegetated, channel lining is infeasible, and velocity checks are required. • Check dams may not be placed in streams unless approved by the State Department of Fish and Wildlife. Check dams may not be placed in wetlands without approval from a permitting agency. • Check dams shall not be placed below the expected backwater from any salmonid bearing water between October 1 and May 31 to ensure that there is no loss of high flow refuge habitat for overwintering juvenile salmonids and emergent salmonid fry. Design and Whatever material is used, the dam should form a triangle when viewed Installation from the side. This prevents undercutting as water flows over the face of Specifications the dam rather than falling directly onto the ditch bottom. Check dams in association with sumps work more effectively at slowing flow and retaining sediment than just a check dam alone. A deep sump should be provided immediately upstream of the check dam. • In some cases, if carefully located and designed, check dams can , remain as permanent installations with very minor regrading. They may be left as either spillways, in which case accumulated sediment would be graded and seeded, or as check dams to prevent further sediment from leaving the site. • Check dams can be constructed of either rock or pea-gravel filled bags. Numerous new products are also available for this purpose. They tend to be re-usable, quick and easy to install,effective, and cost efficient. • Check dams should be placed perpendicular to the flow of water. • The maximum spacing between the dams shall be such that the toe of the upstream dam is at the same elevation as the top of the downstream dam. • Keep the maximum height at 2 feet at the center of the dam. • Keep the center of the check dam at least 12 inches lower than the outer edges at natural ground elevation. • Keep the side slopes of the check dam at 2:1 or flatter. • Key the stone into the ditch banks and extend it beyond the abutments a minimum of 18 inches to avoid washouts from overflow around the dam. February 2005 Volume II— Construction Stormwater Pollution Prevention 4-75 i r. • Use filter fabric foundation under a rock or sand bag check dam. If a `F (_ _ blanket ditch liner is used, this is not necessary. A piece of organic or I synthetic blanket cut to fit will also work for this purpose. • Rock check dams shall be constructed of appropriately sized rock. i. The rock must be placed by hand or by mechanical means (no , dumping of rock to form dam)to achieve complete coverage of the ditch or swale and to ensure that the center of the dam is lower than 111 the edges. The rock used must be large enough to stay in place given the expected design flow through the channel. • In the case of grass-lined ditches and swales, all check dams and I accumulated sediment shall'be removed when the grass has matured sufficiently to protect the ditch or swale - unless the slope of the swale is greater than 4 percent. The area beneath the check dams shall be Iseeded and mulched immediately after dam removal. • Ensure that channel appurtenances, such as culvert entrances below check dams, are not subject to damage or blockage from displaced 0 stones. Figure 4.13 depicts a typical rock check dam. Maintenance Check dams shall be monitored for performance and sediment 0 Standards accumulation during and after each runoff producing rainfall. Sediment shall be removed when it reaches one half the sump depth. • Anticipate submergence and deposition above the check dam and erosion from high flows around the edges of the dam. • If significant erosion occurs between dams, install a protective riprap IIliner in that portion of the channel. 111 I' I p I I I4-76 Volume II- Construction Stormwater Pollution Prevention February 2005 View Looking Upstream 18" (0.5m) I • — A .1, •-a,, ,•00 c3fOR,a, • /`• NOTE: 11,%0TP,• :ct?,Js2' Key stone into channel banks and extend it beyond the abutments a minimum of 18" (0.5m) to prevent — A flow around dam. Section A - A FLOW ---------- 24"(0.6m) cfbc'?._,11,6111 . 43-Y_.(223,QK•0 cfr- , \ • \ .dtcc-)00. \ \,/s•\ \ 8'(2.4m) Spacing Between Check Dams 'L' =the distance such that points 'A'and 'B' are of equal elevation. €ze. 9,,,b • POINT 'A' POINT B' \ \/\ '/ \\/ •\ \%\/ ot=c1 • o6,•••• . 0. % • \\,\ „\\.„,;\ •\"\: \ , NOT TO SCALE • Figure 4.13—Check Dams February 2005 Volume II— Construction Stormwater Pollution Prevention 4-77 I IBMP C220: Storm Drain Inlet Protection ( i Purpose To prevent coarse sediment from entering drainage systems prior to permanent stabilization of the disturbed area. I I Conditions of Use Where storm drain inlets are to be made operational before permanent stabilization of the disturbed drainage area. Protection should be provided for all storm drain inlets downslope and within 500 feet of a disturbed or __ _ construction area, unless the runoff that enters the catch basin will be I conveyed to a sediment pond or trap. Inlet protection may be used anywhere to protect the drainage system. It is likely that the drainage system will still require cleaning. I Table 4.9 lists several options for inlet protection. All of the methods for I storm drain inlet protection are prone to plugging and require a high frequency of maintenance. Drainage areas should be limited to 1 acre or less. Emergency overflows may be required where stormwater ponding I would cause a hazard. If an emergency overflow is provided, additional end-of-pipe treatment may be required. Table 4.9 I Storm Drain Inlet Protetion Applicable for Type of Inlet Emergency Paved/Earthen Protection Overflow Surfaces Conditions of Use I( Drop Inlet Protection Excavated drop inlet Yes, Earthen Applicable for heavy flows. Easy protection temporary to maintain. Large area Iflooding will Requirement: 30'X 30'/acre occur Block and gravel drop Yes Paved or Earthen Applicable for heavy concentrated I inlet protection flows. Will not pond. Gravel and wire drop No Applicable for heavy concentrated inlet protection flows. Will pond. Can withstand I Catch basin traffic. filters Yes Paved or Earthen Frequent maintenance required. Curb Inlet Protection I Curb inlet protection Small capacity Paved overflow Used for sturdy,more compact with a wooden weir installation. Block and gravel curb Yes Paved Sturdy, but limited filtration. inlet protection I Culvert Inlet Protection Culvert inlet sediment 18 month expected life. I trap I i. R. I4-82 Volume 11— Construction Stormwater Pollution Prevention February 2005 111 Design and Excavated Drop Inlet Protection- An excavated impoundment around the Installation storm drain. Sediment settles out of the stormwater prior to entering the Specifications storm drain. • Depth 1-2 ft as measured from the crest of the inlet structure. 111 • Side Slopes of excavation no steeper than 2:1. • Minimum volume of excavation 35 cubic yards. • Shape basin to fit site with longest dimension oriented toward the longest inflow area. • Install provisions for draining to prevent standing water problems. ' • Clear the area of all debris. • Grade the approach to the inlet uniformly. • Drill weep holes into the side of the inlet. • Protect weep holes with screen wire and washed aggregate. • Seal weep holes when removing structure and stabilizing area. j • It may be necessary to build a temporary dike to the down slope side of the structure to prevent bypass flow. Block and Gravel Filter- A barrier formed around the storm drain inlet with standard concrete blocks and gravel. See Figure 4.14. • Height 1 to 2 feet above inlet. • Recess the first row 2 inches into the ground for stability. • Support subsequent courses by placing a 2x4 through the block j opening. • Do not use mortar. • Lay some blocks in the bottom row on their side for dewatering the pool. • Place hardware cloth or comparable wire mesh with'/2-inch openings over all block openings. • Place gravel just below the top of blocks on slopes of 2:1 or flatter. • An alternative design is a gravel donut. • Inlet slope of 3:1. • Outlet slope of 2:1. • 1-foot wide level stone area between the structure and the inlet. • Inlet slope stones 3 inches in diameter or larger. • Outlet slope use gravel 1/2- to 3/4-inch at a minimum thickness of 1-foot. p February 2005 Volume II—Construction Stormwater Pollution Prevention 4-83 Plan View A (_ Drain_ ,-=�a)r�1'',° )i.•„ '-� ' r` rs„ Grate \ '`•:J..- ,;-/:,.- , =,. o ' -: Le- :o��\;o {� f1oQ3J�o° A-SK. 1 .1(7 ; 1:+^`�,;J e i �• 4 , 1rs rt• i ( 1c\C () ._p'/tj ^ : i: =(J '= t& 2 L, — oo +/��;'r���``. \ "-°,'\...,�J,a-(�'.\J • ,:�`�.,^�, \ 4'•Ds'.; > Q Concrete )`r f ,L.` a%l `A :•`:., \°0 •.-;�o Block ---" .ago r �„,: (-. `=.,� • (.+Ly' , y/, v.vG�,�` �,'�!';r;o= ° r�,.; �:a' Gravel jr„ \ -�;0 ,;moo Backfill ),Id',,�,,'-'r.• ,^ (�\ ...-t C-)Y-, \ i, it \ LA r`� cP (i.3\o Section A - A Concrete Block Wire Screen or Filter Fabric Gravel Backfill Overflow Water Ponding Height •,,,67\k`q op° ° o{j(.4 WaterLk— 1 �^�'FiP,_-1<-,�_;no,. / Oo e o nQ a r? OW f c.e.!?7L off°�S',cv.t1Go° . . . i/\:,..j\� Drop Inlet ,.. \\%\'i' :. Notes: 1. Drop inlet sediment barriers are to be used for small, nearly level drainage areas. (less than 5%) 2. Excavate a basin of sufficient size adjacent to the drop inlet. 3. The top of the structure(ponding height)must be well below the ground elevation downslope to prevent runoff from bypassing the inlet. A temporary dike may be necessary on the dowslope side of the structure. Figure 4.14 — Block and Gravel Filter • Gravel and Wire Mesh Filter - A gravel barrier placed over the top of the inlet. This structure does not provide an overflow. • Hardware cloth or comparable wire mesh with 'A-inch openings. ► • Coarse aggregate. • Height 1-foot or more, 18 inches wider than inlet on all sides. • Place wire mesh over the drop inlet so that the wire extends a minimum of 1-foot beyond each side of the inlet structure. • If more than one strip of mesh is necessary, overlap the strips. • Place coarse aggregate over the wire mesh. • The depth of the gravel should be at least 12 inches over the entire inlet opening and extend at least 18 inches on all sides. 4-84 Volume ll— Construction Stormwatar Pollution Prevention February 2005 I Catchbasin Filters -Inserts should be designed by the manufacturer for use at construction sites. The limited sediment storage capacity increases the amount of inspection and maintenance required, which may be daily for heavy sediment loads. The maintenance requirements can be reduced by combining a catchbasin filter with another type of inlet protection. This type of inlet protection provides flow bypass without overflow and J therefore may be a better method for inlets located along active rights-of- way. • 5 cubic feet of storage. • Dewatering provisions. • High-flow bypass that will not clog under normal use at a construction site. • The catchbasin filter is inserted in the catchbasin just below the grating. Curb Inlet Protection with Wooden Weir—Barrier formed around a curb inlet with a wooden frame and gravel. • Wire mesh with 1/2-inch openings. • Extra strength filter cloth. • Construct a frame. • Attach the wire and filter fabric to the frame. • Pile coarse washed aggregate against wire/fabric. • Place weight on frame anchors. Block and Gravel Curb Inlet Protection—Barrier formed around an inlet with concrete blocks and gravel. See Figure 4.14. • Wire mesh with '/2-inch openings. • Place two concrete blocks on their sides abutting the curb at either side of the inlet opening. These are spacer blocks. • Place a 2x4 stud through the outer holes of each spacer block to align the front blocks. • Place blocks on their sides across the front of the inlet and abutting the spacer blocks. • Place wire mesh over the outside vertical face. • Pile coarse aggregate against the wire to the top of the barrier. Curb and Gutter Sediment Barrier—Sandbag or rock berm (riprap and aggregate) 3 feet high and 3 feet wide in a horseshoe shape. See Figure 4.16, • Construct a horseshoe shaped berm, faced with coarse aggregate if using riprap,3 feet high and 3 feet wide, at least 2 feet from the inlet. • Construct a horseshoe shaped sedimentation trap on the outside of the berm sized to sediment trap standards fOr protecting a culvert inlet. February 2005 Volume 11— Construction Stormwater Pollution Prevention 4-85 I . Maintenance • Catch basin filters should be inspected frequently, especially after Standards storm events. If the insert becomes clogged, it should be cleaned or replaced. For systems usingstone filters: If the stone filter becomes clogged ' Y gg with sediment, the stones must be pulled away from the inlet and cleaned or replaced. Since cleaning of gravel at a construction site may be difficult, an alternative approach would be to use the clogged stone as fill and put fresh stone around the inlet. • Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly over the surrounding land area or stockpile and stabilize as appropriate. I N I I I I I I I i 4-86 Volume II— Construction Stormwater Pollution Prevention February 2005 BMP C233: Silt Fence Purpose Use of a silt fence reduces the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. See Figure 4.19 for details on silt fence construction. Conditions of Use Silt fence may be used downslope of all,disturbed areas. • Silt fence is not intended to treat concentrated flows,nor is it intended to treat substantial amounts of overland flow. Any concentrated flows must be conveyed through the drainage system to a sediment pond. The only circumstance in which overland flow can be treated solely by a silt fence, rather than by a sediment pond, is when the area draining to the fence is one acre or less and flow rates are less than 0.5 efs. • Silt fences should not be constructed in streams or used in V-shaped ditches. They are not an adequate method of silt control for anything deeper than sheet or overland flow. Joints in filter fabric shall be spliced at posts.Use staples,wire rings or 2"x2' by 14 Ga.wire or equivalent to attach fabric to posts equivalent,If standard :.a�:eaeee•r : strength fabric used r 699EEEEEEueeeE:EEEoeeet ii eeielieeE:°EEE °EIaEsEi Filter fabricerangeinni eEE::::e•e � :i' e EE::::e:::nuneil •C::C:m:eE:pm III 'EEEe9EP°EeEEEEI 11I; •t— _ - ;t11 u IAA', i,�,T—pitigill41�'LTI�LI= I a"�I n I( 11e11 I Id �i�i - -7,1 6'max — 1 � Minimum 4"x4"trench / i ;E J r Backfill trench with native soil Posh spacing may be Increased \or 3/4"-1.5"washed gravel to 8'it wire backing is used 2"x2"wood posts,steel fence posts,or equivalent Figure 4.19—Silt Fence Design and • Drainage area of 1 acre or less or in combination with sediment basin Installation in a larger site. Specifications • Maximum slope steepness (normal (perpendicular)to fence line) 1:1. • Maximum sheet or overland flow path Iength to the fence of 100 feet. • No flows greater than 0.5 dfs. • The geotextile used shall meet the following standards. All geotextile properties listed below are minimum average roll values(i.e.,the test result for any sampled roll in a lot shall meet or exceed the values shown in Table 4.10): 4-94 Volume II— Construction Stormwater Pollution Prevention February 2005 III-3.1 .1 Downspout Full Infiltration Systems (BMP T5.10A) Downspout full infiltration systems are trench or drywell designs intended only for use in infiltrating runoff from roof downspout drains. They are not designed to directly infiltrate runoff from pollutant-generating impervious surfaces. Application Projects subject to 1-2.5.5 Minimum Requirement#5: On-site Stormwater Management (p.55) must provide for individual downspout full infiltration systems or full dispersion if feasible. Evaluate the feasibility, or applicability, of downspout full infiltration unless full dispersion is proposed. Use the evaluation procedure below to determine the feasibility of downspout full infiltration. Runoff Modeling for Roof Downspout Full Infiltration If roof runoff is infiltrated according to the requirements of this section, the roof area may be discounted from the project area used for sizing stormwater facilities. Procedure for Evaluating Feasibility 1. Have one of the following prepare a soils report to determine if soils suitable for infiltration are present on the site: . A professional soil scientist certified by the Soil Science Society of America (or an equivalent national program) . A locally licensed on-site sewage designer . A suitably trained person working under the supervision of a professional engineer, geologist, hydrogeologist, or engineering geologist registered in the State of Washington. The report shall reference a sufficient number of soils logs to establish the type and limits of soils on the project site. The report should at a minimum identify the limits of any outwash type soils (i.e., those meeting USDA soil texture classes ranging from coarse sand and cobbles to medium sand)versus other soil types and include an inventory of topsoil depth. 2. if the lots or site does not have outwash or loam soils, and full dispersion is not feasible, then consider a rain garden or bioretention BMPs (the next lower priority on-site stormwater management system). 3. Complete additional site-specific testing on lots or sites containing outwash (coarse sand and cobbles to medium sand) and loam type soils. Individual lot or site tests must consist of at least one soils log at the location of the infiltration system, a minimum of 4 feet in depth from the proposed grade and at 2014 Stormwater Management Manual for Western Washington Volume III- Chapter 3-Page 452 n e least 1 foot below the expected bottom elevation of the infiltration trench or dry well. Identify the NRCS series of the soil and the USDA textural class of the soil horizon through the depth of the log, and note any evidence of high ground water level, such as mottling. 4. Downspout infiltration is considered feasible on lots or sites that meet all of the fol- lowing: . 3 feet or more of permeable soil from the proposed final grade to the sea- sonal high ground water table. . At least 1-foot of clearance from the expected bottom elevation of the infilt- ration trench or dry well to the seasonal high ground water table. . The downspout full infiltration system can be designed to meet the minimum design criteria specified below. Design Criteria for Infiltration Trenches Figure III-3.1.2 Typical Downspout Infiltration Trench (p.455) shows a typical downspout infiltration trench system, and Figure III-3.1.3 Alternative Downspout Infiltration Trench System for Coarse Sand and Gravel (p.456) presents an alternative infiltration trench sys- tem for sites with coarse sand and cobble soils. These systems are designed as spe- cified below. General 1. The following minimum lengths (linear feet) per 1,000 square feet of roof area based on soil type may be used for sizing downspout infiltration trenches. Coarse sands and cobbles: 20 LF Medium sand: 30 LF Fine sand, loamy sand: 75 LF Sandy loam: 125 LF Loam: 190 LF 2. Maximum length of trench shall not exceed 100 feet from the inlet sump. 3. Minimum spacing between trench centerlines shall be 6 feet. 4. Filter fabric shall be placed over the drain rock as shown on Figure III-3.1.2 Typical Downspout Infiltration Trench (p.455) prior to backfilling. 5, Infiltration trenches may be placed in fill material if the fill is placed and compacted under the direct supervision of a geotechnical engineer or professional civil 2014 Stormwater Management Manual for Western Washington Volume Ill- Chapter 3-Page 453 engineer with geotechnical expertise, and if the measured infiltration rate is at least 8 inches per hour. Trench length in fill must be 60 linear feet per 1,000 square feet of roof area. Infiltration rates can be tested using the methods described in Section 3.3. 6. Infiltration trenches should not be built on slopes steeper than 25% (4:1). A geo- technical analysis and report may be required on slopes over 15 percent or if loc- ated within 200 feet of the top of slope steeper than 40%, or in a landslide hazard area. 7. Trenches may be located under pavement if a small yard drain or catch basin with grate cover is placed at the end of the trench pipe such that overflow would occur out of the catch basin at an elevation at least one foot below that of the pavement, and in a location which can accommodate the overflow without creating a sig- nificant adverse impact to downhill properties or drainage systems. This is inten- ded to prevent saturation of the pavement in the event of system failure. Design Criteria for Infiltration Drywedl Figure III-3.1.4 Typical Downspout Infiltration Drywell (p,457).shows a typical downspout infiltration drywell system. These systems are designed as specified below. General 1. Drywell bottoms must be a minimum of 1 foot above seasonal high ground water level or impermeable soil layers. 2. When located in course sands and cobbles, drywells must contain a volume of gravel equal to or greater than 60 cubic feet per 1000 square feet of impervious sur- face served. When located in medium sands, drywells must contain at least 90 cubic feet of gravel per 1,000 square feet of impervious surface served, 3. Drywells must be at least 48 inches in diameter (minimum) and deep enough to contain the gravel amounts specified above for the soil type and impervious sur- face served. 4. Filter fabric (geotextile) must be placed on top of the drain rock and on trench or dry- well sides prior to backfilling. 5. Spacing between drywells must be a minimum of 10 feet. 6. Downspout infiltration drywells must not be built on slopes greater than 25% (4:1). Drywells may not be placed on or above a landslide hazard area or on slopes greater than 15% without evaluation by a professional engineer with geotechnical expertise or a licensed geologist, hydrogeologist, or engineering geologist, and with jurisdiction approval. 2014 Stormwater Management Manual for Western Washington Volume III- Chapter 3-Page 454 BMP T5.13 Post-Construction Soil Quality and Depth Purpose and Definition Naturally occurring(undisturbed) soil and vegetation provide important stormwater functions including: water infiltration;nutrient, sediment,and pollutant adsorption; sediment and pollutant biofiltration;water interflow storage and transmission;and pollutant decomposition. These functions are largely lost when development strips away native soil and vegetation and replaces it with minimal topsoil and sod. Not only are these important stormwater functions lost, but such landscapes themselves become pollution- generating pervious surfaces due to increased use of pesticides, fertilizers and other landscaping and household/industrial chemicals,the concentration of pet wastes, and pollutants that accompany roadside litter. Establishing soil qualityand depth regains greater stormwater functions in the post development landscape,provides increased treatment of pollutants and sediments that result from development and habitation,and minimizes the need for some landscaping chemicals,thus reducing pollution through prevention. Applications and Limitations Establishing a minimum soil quality and depth is not the same as preservation of naturally occurring soil and vegetation. It also does not maximize the stormwater functions that could be attained through greater soil depth and more specialized formulations as presented in BMP T5.35, Engineered Soil/Landscape Systems. However, establishing a minimum soil quality and depth will provide improved on-site management of stormwater flow and water quality. Soil organic matter can be attained through numerous materials such as compost, composted woody material,biosolids, and forest product residuals. It is important that the materials used to meet the soil quality and depth BMP be appropriate and beneficial to the plant cover to be established. Likewise, it is important that imported topsoils improve soil conditions and do not have an excessive percent of clay fines, Design Guidelines • Soil retention. The duff layer and native topsoil should be retained in an undisturbed state to the maximum extent practicable. In any areas requiring grading remove and stockpile the duff layer and topsoil on site in a designated, controlled area,not adjacent to public resources and critical areas,to be reapplied to other portions of the site where feasible. • Soil quality. All areas subject to clearing and grading that have not been covered by impervious surface, incorporated into a drainage facility or engineered as structural fill or slope shall, at project completion, demonstrate the following: 5-12 Volume V—Runoff Treatment BMPs August 2001 1. Retention or enhancement of the moisture infiltration rate and soil moisture holding capacity of the original undisturbed soil native to the site. Areas which have been compacted or have removed some or all of the duff layer or underlying top soil shall be amended to mitigate for lost moisture infiltration and moisture holding capacity; and 2. A topsoil layer with a minimum organic matter content of ten percent dry weight and a pH from 6.0 to 8.0 or matching the pH of the original undisturbed soil. The topsoil layer shall have a minimum depth of eight inches except where tree roots limit the depth of incorporation of amendments needed to meet the criteria. Subsoils below the topsoil layer should be scarified at least 4 inches with some incorporation of the upper material to avoid stratified layers,where feasible. • These criteria can be met by using on-site native topsoil, incorporating amendments into on-site soil, or importing blended topsoil. If blended topsoil is imported, then fines should be limited to twenty-five percent passing through a 200 sieve. • The resulting soil should be conducive to the type of vegetation to be established. Maintenance • Soil quality and depth should be established toward the end of construction and once established, should be protected from compaction, such as from large machinery use, and from erosion. • Soil should be planted and mulched after installation. • Plant debris or its equivalent should be left on the soil surface to replenish organic matter. • It should be possible to reduce use of irrigation, fertilizers,herbicides and pesticides. These activities should be adjusted where possible, rather than continuing to implement formerly established practices. August 2001 Volume V—Runoff Treatment BMPs 5-13 BMP T5.14A: Rain Gardens Purpose and Definition Land development projects may not be of sufficient size such that it is practical to con- struct engineered stormwater facilities for flow reduction and pollutant removal. However, the cumulative impact of smaller development projects on the natural hydro- logy and water quality of local waters can be significant. To reduce that cumulative impact, small projects (see 1-2.4 Applicability of the Minimum Requirements (p.35)) must implement on-site stormwater management BMP's (See 1-2.5.5 Minimum Requirement #5: On-site Stormwater Management(p.55)). Rain gardens are an on-site stormwater management BMP that can provide effective removal of many stormwater pollutants, and provide reductions in stormwater runoff quantity and surface runoff flow rates. Rain gardens are non-engineered, shallow, landscaped depressions with compost- amended soils and adapted plants. The depression ponds and temporarily stores storm- water runoff from adjacent areas. A portion of the influent stormwater passes through the amended soil profile and into the native soil beneath. Stormwater that exceeds the stor- age capacity is designed to overflow to an adjacent drainage system. Applications and Limitations Rain gardens are an on-site stormwater management BMP option for projects that have to comply with Minimum Requirements#1 -#5, but not Minimum Requirements#6 -#9. For projects electing to use List#1 of 1-2.5.5 Minimum Requirement#5: On-site Storm- water Management(p.55), rain gardens are to be used to the extent feasible for runoff from roofs and other hard surfaces unless a higher priority BMP is feasible. Infeasibility criteria for rain gardens are the same as for bioretention. Please see Biore- tention infeasibility criteria in BMP T7.30: Bioretention Cells, Swales, and Planter Boxes (p.959). Although not required, Ecology recommends installation by a landscaping company with experience in rain garden construction. Rain gardens constructed with imported compost materials should not be used within one-quarter mile of phosphorus-sensitive waterbodies. Preliminary monitoring indicates that new rain gardens can add phosphorus to stormwater. Therefore, they should also not be used with an underdrain when the underdrain water would be routed to a phos- phorus-sensitive receiving water. Design Guidelines Refer to the Rain Garden Handbook for Western Washington (2013)for rain garden spe- cifications and construction guidance. 2014 Stormwater Management Manual for Western Washington Volume V- Chapter 5-Page 915 H G For amending the native soil within the rain garden, Ecology recommends use of com- post that meets the compost specification for bioretrention (see BMP T7.30: Bioretention Cells, Swales, and Planter Boxes (p.959)). Compost that includes biosolids or manures shall not be used. For design on projects subject to 1-2.5.5 Minimum Requirement#5: On-site Stormwater Management(p.55), and choosing to use List#1 of that requirement, rain gardens shall have a horizontally projected surface area below the overflow which is at least 5% of the total impervious surface area draining to it. If lawn/landscape area will also be draining to the rain garden, Ecology recommends that the rain garden's horizontally projected sur- face area below the overflow be increased by 2% of the lawn/landscape area. Underdrains Ecology does not recommend the use of underdrains for rain gardens. Design and con- struction of an underdrain system likely requires professional expertise. Where a muni- cipality intends to require or allow underdrained rain gardens in areas with initial infiltration rates between 0.3 and 0.6 inches per hour, the invert of the underdrain shall be 6 inches above the bottom of the aggregate bedding for the underdrain. A larger dis- tance between the underdrain and the bottom of the aggregate bedding is desirable, but cannot be used to trigger infeasibility due to inadequate vertical separation to the sea- sonal high water table, bedrock, or other impermeable layer. Ecology recommends that the municipality establish standard design specifications and drawings. Maintenance Please refer to the Rain Garden Handbook for Western Washington (2013)for tips on mulching, watering, weeding, pruning, and soil management. The "Western Washington Low Impact Development(LID)Operation and Maintenance (O&M) Guidance Docu- ment" may be consulted for more detailed guidance. BMP T5.14B: Bioretention Purpose and Definition Bioretention areas are shallow landscaped depressions, with a designed soil mix and plants adapted to the local climate and soil moisture conditions, that receive stormwater from a contributing area. Bioretention provides effective removal of many stormwater pollutants by passing storm- water through a soil profile that meets specified characteristics. Bioretention can also reduce stormwater runoff quantity and surface runoff flow rates significantly where the exfiltrate from the design soil is allowed to infiltrate into the surrounding native soils. 2014 Stormwater Management Manual for Western Washington Volume V- Chapter 5-Page 916 10µ..avnik yA' ssociates Inc. CIVIL ENGINEERING & LAND-USE PLANNING Date: November 15, 2017 @vmE0 Nov C 6 2011 To: Tim Hohmann From: Heike Nelson, PE CITY OF AWACCORTFS Subject: Response to City Drainage Plan Review#1 for 2202 15th Street The following is a response to City comments provided for 2202 15th Street was reviewed by the Public Works Engineering Department on November 14, 2017. The following comments were provided by City staff, a response to each comment is provided below in italics: Stormwater Site Plan: • The stormwater site plan and SWPPP are included on the same plan sheet and have been previously reviewed by the planning department. Accordingly additional detailed review of the site plan in regard to MR#1 to#5 was not performed as a part of this review. However the following items were noted as missing during this review: • A reference on the site plan and in the detail to the requirement of BMP T5.13 Post Construction Soil Quality and Depth for all proposed lawn areas in area disturbed by construction activities. Please include on plans and in details. A note has been added as requested. • The site plan needs to be revised to show a 2-foot wide transition zone adjacent to the driveway per BMP T5.12. Include BMP T5.12 detail on BMP detail sheet. We have added a 2-foot gravel spreader to assure even distribution of runoff along the west side of the driveway, however it should be noted that the 2-foot transition zone noted BMP T5.12 is specified for a dispersion facility and this driveway is proposed to infiltrate into the adjoining lawn/landscape area to the west. The 2-foot transition zone will not provide a 25-foot setback from the property line as noted on the detail for a sheet flow dispersion. Drainage Report: • The site plan shows 5231 SF of impervious area but the report only addresses 5036 SF. This appears to be because the drainage report mentions but does not address the onsite walkways shown on the plan. Please revise drainage report to address all hard surface areas included in the project. The 195 square feet difference is due to the small areas of sidewalk which will simply be cross-sloped to convey runoff onto adjoining areas where they can percolate into the underlying soils. This will make these surfaces "ineffective" and therefore there is no need to calculate runoff values. We have added a specific note to direct this cross-sloping on the site plan. 1633 LINDAMOOD LANE / P.O. Box 361 • BURLINGTON, WA 98233 PH: (360) 707-2048 • Fax: (360) 707-2216 • The drainage report mentions multiple time that the project is flow control exempt because water is infiltrated by the project there by reducing the effective impervious surface below the thresholds included in MR#7 for the standard flow requirement. This is not an exemption to MR#7 and reference in the drainage report of this being an exemption should be removed from the drainage report. We have updated the text to remove the word exempt/exemption and simply noted that the project simply does not break the established thresholds requiring the requirement. • However this project is flow control exempt according to the applicability requirements of MR#7 as it indirectly discharges to salt water via the City stormwater system. This exemption is not included in the drainage report and should To satisfy the requirements of the flow control exemption due to the indirect discharge to salt water would require us to prove that the downstream conveyance system has capacity to convey runoff. Due to the small size and scope of this project it is not financial feasible to perform this work when the project is not required to meet MR#7 due to the minimal increase of runoff anticipated from the development of a single-family house. • When calculating the house basin and sizing the infiltration trench an infiltration rate of 6.33 in/hr is used. The infiltration rate recommended in the stormwater infiltration evaluation (geotech report) included for review is 1.5 in/hr. The infiltration rate recommended by the project geotech should be used for all drainage calculations and facility sizing. Please recalculate and revise report and facility design using the correct infiltration rate. Alternately the infiltration trench can be sized without calculation in accordance with the Design Criteria contained in BMP 5.10A in section 111-3.1.1 of the DOE manual. Use of the infiltration rates noted as long term infiltration rates within the table provided in the Geotech report which were obtained from test pits located within the specific area of the site where the infiltration trench will be placed and at depths where the trench bottom will be placed is the most accurate way to determine how the infiltration trench will function. This noted, we have reanalyzed this infiltration system using the reduced 1.5 inch per hour infiltration rate as requested. The report has been updated to note the results of this new analysis. The WWHM model indicates that using the reduced 1.5 inches per hour the 46 lineal feet of proposed infiltration trench will infiltrate 99.42% of all storms. When reviewing the yearly data from the WWHM flow frequency information for 801 (mitigated) indicates that at most the year 1965 indicated 0.0290 cfs would overflow from the 46-foot long infiltration trench. An additional calculation was provided within the report to show that it would only take approximately 8.2 feet of lawn/landscape area downgradient of the infiltration trench for these rare overflows to be infiltrated. This assures to the best of our engineering ability that stormwater runoff from developed surfaces will be infiltrated onsite rather than counting on a boiler plate length. • The driveway basin section goes into great detail to calculate the amount of lawn area needed to disperse the driveway runoff. This is BMP T5.12 Sheet flow dispersion. BMP T5.12 contains design guidelines for the width of the vegetated buffer namely- "Provide a 10-foot-wide vegetated buffer for up to 20 feet width of paved impervious surface. Provide an additional 10 feet of vegetated buffer width for each additional 20 feet of impervious surface width or fraction thereof." Please revise drainage report to account for these design guidelines. It is nit much work to c„lculate the estimated runoff and determine exactly how much area is needed to infiltrate runoff from various sud?aces, For this project the developed runoff rates needed to be calculated to determine if the developed runoff flow rates increased more than 0.1 cfs and thus not required to provide runoff control. Once you have the developed runoff rates determined it is simple to det-rrnine exactly how much area is needed t;, fully infiltrate the runoff. We prefer to do this caalculatiin especially if there is no downstream detention being provided. The dispersion guidelines referred to are intended for dispersion, not for infiltration purposes. Providing this design information again assures to the best of our engineering ability that stormwater runoff from developed suefaaces will be infiltrated onsitr. ® The Sidewalk basin of the drainage report needs to correctly reference that the basin is below the thresholds for runoff treatment and flow control and not just"exempt" from runoff control. We have updated the report to change the word exempt per your request. ® It is unclear from the WWHM printouts provided where the 100 year runoff of 0.047cfs for the developed but unmitigated roof basin runoff was calculated. Please provide verification via printout of this flow calculation. I have flagged this number for your review, it is noted in cilumn 701 on the WWMH flow frequency view for the house model. I am not sure why NfifWHAN does not include the 701 "develope;+'unmitigated"runoff vaIvi s. This is one of the reasons we include the screen views to help clarify. • The Minimum Requirement#5 section of the drainage report incorrectly states that because the project is flow control exempt this project is not required to follow List #2. According to the section 1-2.5.5 of the DOE manual - "Projects qualifying as flow control exempt in accordance with 1-2.5.7 Minimum Requirement#7: Flow Control do not have to achieve the LID performance standard, nor consider bioretention, rain gardens, permeable pavement, and full dispersion if using List#1 or List#2. However, those projects must implement BMP T5.13: Post-Construction Soil Quality and Depth; BMP T5.1 OA: Downspout Full Infiltration or BMP T5.1 OB: Downspout Dispersion Systems or BMP T5.1 OC: Perforated Stub-out Connections; and BMP T5.11: Concentrated Flow Dispersion or BMP T5.12: Sheet Flow Dispersion, if feasible." Once again this flow control exemption is due to the project indirectly discharging to salt water via the City stormwater system not due to falling below the threshold for the standard flow control requirement. The drainage report should be revised to correctly state this and to demonstrate how the applicable List#2 options were addressed for the various project basins. This project dies not exceed the DOE thresholds to require flow control as the developed, unmitigated increase is estimated to be less than 0.1 cfs and has less than 10,000 sf if effective impervious surface. The developed runifv`from the house and driveway have been proven to be infiltrated oresite using rates determined from WWHId (a continuous model software). We have revised the report to note that infiltration was used for the house, driveway, and onsite sidewalks, while dispersion will be used to address the offsite sidewalk area proposed with this project. O The Minimum Requirement#5 section of the drainage report needs to address the requirements of BMP T5.13: Post-Construction Soil Quality and Depth for lawn areas disturbed during construction and lawn areas receiving sheet flow for dispersion from the driveway. We have added a note to the repoUd and the site plan to clarify this as requested. O The Minimum Requirement#6 section of the drainage report should state that the project does not require the construction of stormwater treatment facilities as the total PGMS is less that 5000 SF and the total PGPS is less than 3/4 acre. It can further go on to state that driveway runoff is being treated as it is dispersed per the design guidelines of BMP T5.12 Sheet Flow Dispersion. We have added the requested text to provide further.clarification regarding water quality. • The Minimum Requirement#7 section needs to be revised to correctly state the flow control emption with regard to this project. We have removed the word "exempt"and better described that the project simply does not exceed the DOE thresholds to require r niff control. ® The Minimum Requirement#9 section of the drainage report need to address ownership and operations and maintenance responsibilities for the stromwater facilities including LID BMPs, as a part of this project. All BMPs receiving private onsite stormwater shall be the responsibility of the lot owner. We have added a this rote as requested. Thank you for providing us your comments. Please let us know if we can help further. Sincerely, Heike L Nelson, PE Ravnik & Associates, o. y CIVIL ENGINEERING & LAND-USE PLA A° z, , STORM DRAINAGE MEMO 39891 for 2202 15TH Street � loNA1 (BLD-2017-0349) LANDED GENTRY HOMES RESIDENTIAL DEVELOPMENT' nn Revised:November 15, 2017 October 26, 2017 NOV 1 6 2017 September 29, 2017 The residential development proposed herein located at 2202 15th Street � tl i grt ,ACORTES Washington is generally proposed to include construction of a new house and driveway which will create an increase in the stormwater runoff from the site. The new roof area (3,376 sf), driveway (1,190 sf), onsite pathways (195 sf), and new offsite sidewalk (470 sf) for a total of 5,231 sf of new impervious surfaces on a 10,475 square foot lot where an existing building, gravel and lawn areas currently exist. Stormwater runoff from the proposed 3,376 sf house roof area will be collected by downspouts and conveyed via a tight-lined system to a proposed infiltration trench to be installed within the northerly area of the lot. The driveway will be cross-sloped downhill to the west to promote dispersion and infiltration of runoff waters onto adjoining lawn areas which area large enough to infiltrate up to the 100-year storm as noted further on within this report. The sidewalk will collect runoff via a new gutter and convey it east,then north along the west side of"D"Avenue where it will enter an existing catch basin, as generally occurs today. Small areas of impervious surfaces, such as onsite walkways (195 sf), will simply be graded to disperse runoff via sheet flow onto adjoining areas of lawn/landscaping where there is sufficient area to infiltration the runoff from these small areas of hard surface as described further within this report. Initially the DOE Flow Chart 1-2.4.1 Flow Chart for Determining Requirements for New Development has been used to determine that all minimum requirements apply to the new and replaced hard surfaces and converted vegetation areas. Most notably are Minimum Requirements #5-Onsite Stormwater Control, #6-Runoff Treatment, & #7-Flow Control. This project proposes to infiltrate runoff generated from a majority of the new and replaced hard surfaces as noted within the following sections of this report. Since the design within this report notes impervious surfaces (with the exception of the sidewalk) will be infiltrated as confirmed by use of a continuous model software(WWHM)they are considered "ineffective impervious surfaces", and therefore do not exceed the thresholds requiring the project to provide Minimum Requirement #7-Flow Control per DOE Volume I Section I-2.5.7. Since this project discharges to an unrestricted water body (saltwater bay), it would additionally be considered exempt from runoff control, however this would require that it is proven that all downstream conveyance facilities have capacity to convey increased flows. This being a small residential project the expense of P:\Projectsil7020DOCSIDrainage Memo 11.15.17.doc 1 1633 LINDAMOOD LANE / P.O. Box 361 • BURLINGTON, WA 98233 PH: (360) 707-2048 • FAX: (360) 707-2216 performing a downstream analysis is not cost effective, especially since as previously noted,the project is already not required to provide flow control. As required by the 2014 Department of Ecology Stormwater Manual, the Western Washington Hydrology Model (WWHM), a continuous model software,has been used to calculate pre-developed runoff conditions, post-developed runoff conditions, and the combined performance of storage volume and infiltration discharge. As further described herein, an underground detention/infiltration facility will be used to infiltrate the runoff from the new house. When sizing infiltration trenches using WWHM software, a theoretical riser outlet structure is purposely included within the analysis. If water is found to be released through the riser structure,the volume of rainfall upon the developed site will be considered to have exceeded the system's infiltration and detention capacities, thereby identifying a failure in design. A properly designed and most efficient drainage system will use the infiltration and detention facilities to their maximum capacities without noting any water released through the theoretical riser used in the model. WWHM is also used to estimate 100-year runoff rates generated from the new driveway area in order to determine how much area will be needed to infiltrate 100% of the runoff waters. Using WWHM three models were created to demonstrate the performance of the (1) Infiltration trench to infiltrate roof runoff, (2) Determine the necessary area required to infiltrate runoff from the proposed driveway area, (3) Determine the runoff rates generated from the 470 sf of new sidewalk proposed along the project frontage and (4)to confirm the overall project and the proposed mitigation meet the requirements of the LID Performance Method and the project receives a"Pass". House Basin: Using an infiltration rate of 1.50 inches per hour as noted within the geotechnical report prepared by Geotest for this project, and using the 46 if of 2-foot wide x 2-feet deep infiltration trench having a bottom elevation set at 3-feet below surface will infiltrate is necessary to infiltrate 99.46% of the post-developed runoff generated from the new 3,376 sf(0.77-ac) house roof area as estimated by WWHM software,with the largest remaining storm events anticipated by the 1965 storm event which WWHM estimated to result in an overflow of 0.0290 cfs from the proposed 46-foot long infiltration trench. Refer to calculations below showing how the trench was sized, and how the small amount of overflow that will occasionally occur is infiltrated onto adjoining lawn/landscape areas. Also please refer to WWMH views, and the WWHM Report and calculations attached with this memo for more detailed analysis information. Proposed Infiltration Trench(tight-lined to downspouts): 46' long x 2' deep x 2' deep Drainrock filled trench w/4"perforated pipe Void Ratio: 0.39—Refer to "Infiltration trench w/pipe"spreadsheet attached Infiltration: 1.50 in/hr(per the geotechnical report prepared by Geotest dated 08/30/17) P:1Projects1170201DOCSlDrainage Memo 11.15.17.doc 2 Per WWHM analysis the 46-foot long infiltration trench noted above is estimated to detain and infiltrate 99.46%of the post-developed runoff generated from the new 3,376 sf(0.77-ac)house roof area when using a conservative 1.50 inches per hour infiltration rate. Of the 0.54%of storms which do not fully infiltrate, WWHM identifies the 1965 storm causes largest estimated overflow from the infiltration trench, at 0.0290 cfs,per the WWHM information report for the house attached. Using the same 1.50 inch per hour infiltration rate it is calculated that it will take approximately 1 . -feet of downgradient vegetated pervious area to infiltrate the overflow from the 46-fot6long infiltration trench. Refer to calculations below. , Infiltration Rate Use 1.50 inch/hour =0.0250 inch/min =0.0000347 fps Required Infiltration Area for 0.0290 cfs for overflow from infiltration trench (Per WWHM report historically the 1965 storm is anticipated have the largest overflows) 0.0290 cfs/0.0000347 fps = 835 square feet of area required to infiltrate the overflow runoff from the 1965 storm event. Since the length of proposed infiltration trench is 46 feet, it is estimated that it will take approximately 1.8 16 feet of width of vegetation along the north side of the infiltrat on trench to infiltrate the entire runoff file or 100% of runoff ge erated from the house site based on WWFIIVI analysis. ,•rti Based on the infiltration trench length of 46 feet, 99.46% of the developed runoff full infiltration will be achieved by use of 46 if of 2-foot wide x 2-foot deep drainrock filled infiltration french, in.l8.1-6 feet.. Since the approved runoff model methods note that the house runoff file will infiltrated, and therefore the house is considered to be "ineffective" per (per the definition of "Effective Impervious Surface"(DOE Manual Volume I-Appendix G). The attached Memo prepared by Geotest Engineers notes that the proposed infiltration trench is extremely unlikely to negatively impact any surrounding foundations at its proposed location 11-feet from the north property line. Driveway Basin: To calculate the requirements to infiltrate the runoff generated from the proposed driveway surface, WWHM will be used to calculate the 100-year flow frequency runoff that will be generated from the 1,190 sf(0.028 acre) of driveway area to be infiltrated onto adjoining lawn area. Based on this analysis the 100-year storm event runoff values increase from 0.0016 cfs during the predeveloped (forest) condition up to 0.0171 cfs for the post developed (concrete) condition. This 0.0155 cfs increase in runoff that is anticipated from the conversion of 0.028 acres driveway area from forested condition to concrete can easily be infiltrated onto the undeveloped landscape area located to the west of the proposed driveway. Using a 1.50 in/hr surface infiltration rate from the attached P:1Projects1170201DOCSIDrainage Memo 11.15.17.doc 3 i geotechnical report prepared by Geotest, it only will take approximately 493 sf of area to infiltrate the 100-year storm event in an area where there is over 1,200 sf of yard area available. Refer to the following equations: Infiltration Rate Use 1.50 inch/hour =0.0250 inch/min =0.0000347 fps Required Infiltration Area for 0.028 ac driveway for 100-year storm 0.0171 cfs/0.0000347 fps = 493 square feet of area required to infiltrate the runoff from the developed 100-year storm event for the entire driveway area. Since the length of driveway is approximately 40 feet, it is estimated that it will take approximately 12.31 feet of width of vegetation and/or undisturbed soil along the west side of the driveway to infiltrate runoff from the 100-year storm. Based on the driveway length of 40 feet, full infiltration will be achieved in 12.31 feet. As with the roof runoff, since WWHM analysis (an approved continuous runoff modeling method) indicates that entire runoff file is infiltrated,the house is considered to be "ineffective" per (per the definition of"Effective Impervious Surface"). Refer to the WWHM view and information provided at the end of this report confirming these calculations, and that the entire runoff file is infiltrated in a 12.31-foot x 40-foot area adjacent to the west side of the proposed driveway area as confirmed by showing that 0 cfs is released from the site via a theoretical riser on the attached views. The requirements of BMP T5.13: Post-Construction Soil Quality and Depth for lawn areas disturbed during construction and lawn areas receiving sheet flow from the driveway areas as noted on the site plan exhibit. Sidewalk Basin (Offsite): To estimate the 100-year flow frequency runoff that will be generated from the 470 sf (0.011 acre) of new sidewalk area WWHM will be used. Based on this analysis the 100- year storm event runoff values increase from 0.0006 cfs during the predeveloped (forest) condition up to 0.0067 cfs for the post developed(concrete) condition. Therefore there is only a 0.0061 cfs increase in runoff anticipated from the conversion of 0.011 acres from forested condition to concrete sidewalk. This area is considered Non-Pollution Generating Impervious surface (NPGIS) and additionally this surface is classified as "effective impervious surface" per the DOE manual. This new sidewalk area will be sloped to direct flows northerly to disperse onto the adjoining lawn/landscaping where there is sufficient area for waters to disperse and infiltrate into the underlying soils which have at least 1.5 inch per hour infiltration rate. This small increase in "effective impervious surface" generated with this project will not have a significant impact on the lawn area and does not exceed the flow or area thresholds requiring Runoff Treatment P:Projeetsl170201DOCSIDrainage Memo 11.15.17.doc 4 (Minimum Requirement #6) or Runoff Control (Minimum Requirement #7) as noted within the summery section of this report. The requirements of BMP T5.13: Post-Construction Soil Quality and Depth for lawn areas disturbed during construction and lawn areas receiving sheet flow from the driveway areas as noted on the site plan exhibit. Walkways/Patio Areas (Onsite-195 sf): Runoff from the 195 sf of onsite walkways/patio areas will be cross sloped downhill towards adjoining lawn/landscape areas where there is sufficient room for developed runoff waters to percolate into the underlying soils before discharging the site. Simply based on the above estimations for infiltrating runoff from the proposed 20 to 32-foot wide driveway the amount of area it will take to infiltrate the developed runoff from these areas can be proportionally determined. Based on the 12.31 feet of width that was determined to be needed to infiltrate the driveway, conservatively a 5-foot wide surface would take approximately 3.08 feet of vegetated surface to fully infiltrate: (5-feet/20-feet)x 12.31-feet=3.08 feet Adjoining these various walkway/patio areas there is more than 16-feet of available vegetated surface, therefore more than enough area to assure runoff will not exit the property up to a 100-year storm event. The requirements of BMP T5.13: Post-Construction Soil Quality and Depth for lawn areas disturbed during construction and lawn areas receiving sheet flow from the driveway areas as noted on the site plan exhibit. Summary, For the proposed roof area, based on the areas previously noted, tight-lining roof downspouts to a 46-foot long x 2-foot-wide x 2-feet-deep drainrock filled infiltration trench(w/ a 4-inch diameter perforated pipe) and promoting driveway runoff to flow onto areas with vegetated length greater than 12.31-feet is sufficient to mitigate the increase in stormwater runoff that will be created by the construction of this new house and driveway. Both of these new impervious surfaces are considered ineffective per DOE definition of "Effective Impervious Surface" within the DOE Manual (Volume I- Appendix G) as they have been proven to fully infiltrate. As previously determined using the WWHM analysis, the new roof area, new driveway, and onsite walkways therefore these hard surfaces are classified "ineffective" per the DOE manual, leaving only the new roadside sidewalk being an "effective" impervious surface. The new roof area, driveway, and new offsite sidewalk, only increase the 100-year flow frequency runoff from 0.0065 cfs for the pre-developed condition to 0.0709 cfs during the post-developed condition as noted below: P:lProjects117020IDOCSIDrainage Memo 11.15.17.doc 5 PreDeveloped Runoff(501) Post Developed Runoff(701,Unmitigated) House 0.0043 cfs 0.0471 cfs Driveway 0.0016 cfs 0.0171 cfs Offsite Sidewalk 0.0006 cfs 0.0067 cfs Total 0.0065 cfs 0.0709 cfs This shows there is only a 0.0644 cfs net increase in runoff during the 100-year flow frequency as estimated using the WWHM model, which is less than 0.10 cfs threshold, therefore this project is not required to provide Flow Control (DOE Requirement #7) as noted in the following paragraph even when conservatively accounting for runoff from the impervious surfaces classified as"ineffective". Refer to the WWHM views at the end of this report noting these flow rates for the House,Driveway, and Sidewalk basin areas. Per DOE section 2.5.7-Minimum requirement#7-Flow Control a project is only required to provide flow control is the project if: 1) The project has less than 10,000 square feet of effective impervious surfaces, 2) The project converts less than 3/ acre of vegetation to lawn for landscape (or converts less than 2.5 acres of native vegetation to pasture), and 3) Through a combination of effective hard surface and converted vegetation areas cause less than a 0.10 cubic feet per second increase in the 100-year flow frequency as estimated using the WWHM model. The analysis determining the difference in flow was conservatively performed using the forested land cover for the predeveloped condition as per the footnote in DOE Manual Volume I-Chapter 2 (page 65) states that the 0.10 cfs increase should be a comparison of the post project runoff to the existing conditions runoff based on the pre-project land cover, or the land cover that existing at the site as of a date when the local jurisdiction first adopted flow control requirements into code. Since this project has shown that proposed roof, driveway, and onsite walkway areas are infiltrated technically makes these hard surfaced areas "ineffective impervious area" (per the definition of"Effective Impervious Surface" (DOE Manual Volume I-Appendix G). Therefore this results in the project only having 470 sf of offsite sidewalk that is "effective impervious surface" and this is less than a total of 10,000 square foot threshold of the "effective impervious surfaces" and the developed runoff rates increase less than 0.10 cfs during the 100-year flow frequency(per WWHM), this project is not required to provide Runoff Control as noted. Furthermore, since this is determined that this project is not required to provide Flow Control, in accordance with DOE Manual Volume I- Section 2.5.7 as noted above, this project is not required to meet LID performance or nor consider bioretention, raingardens, permeable pavement or Full Dispersion requirements, or follow List#1 or#2,however the project is required to implement BMP T5.13; BMP's T5.10 A, B, or C; and BMP's T5.11 and T5.12 as feasible to conform to Minimum Requirement#5-Onsite Stormwater Management. P.lProjectsl17020\DOCSlDrainage Memo 11.15.17.doe 6 DOE MINIMUM REQUIREMENTS Based on the thresholds noted within the 2014 Department of Ecology Manual's Flow Chart for Determining Requirements (Figure 2.2) attached, the proposed single-family residential development requires the project to meet Minimum Requirements #1-9, however since the engineering analysis using an approved continuous model software shows that use of the infiltration trench will infiltrate the roof runoff, and it has calculated that there is sufficient area to the west of the new driveway to disperse and infiltrate runoff onto adjoining vegetated areas to remain, this project is not required to provide runoff controls, and subsequently only minimal Onsite Stormwater Management requirements as noted below. The following are the DOE Minimum Requirements #1-9 and how they are addressed: Minimum Requirement#1-Preparation of a Stormwater Site Plan The owner will provide a stormwater site plan which addresses development principles noted within this report. Minimum Requirement#2-Construction Stormwater Pollution Prevention (SWPP) Prior to commencing any construction the project's contractor must prepare a Construction Stormwater Pollution Prevention Control Plan that identifies the measures they will address each of the 13 Construction SWPPP Elements as necessary to prevent the erosion and discharge of sediment and other pollutants from the site. Minimum Requirement#3-Source Control of Pollution No source control BMP's are anticipated with this residential project. Minimum Requirement#4-Preservation of Natural Drainage Systems and Outfalls This project proposes to infiltrate runoff waters other than the small amount of runoff from the new sidewalk which will be conveyed to the existing drainage systems that currently receive runoff from the area. Minimum Requirement#5-On-Site Stormwater Management This item requires the employment of On-site stormwater management BMP's to encourage infiltration and dispersion of developed stormwater runoff. Thought not required for this project, the LID Performance method has been used to confirm the overall project including the proposed infiltration received a Pass. It should be noted that this project is not required to provide LID Performance Standard,nor consider bioretention,raingardens,permeable pavement or Full Dispersion requirements, or follow List#1 or#2, however the project is required to implement BMP T5.13;BMP's T5.10 A, B, or C; and BMP's T5.11 and T5.12 as feasible. In previous sections within this report it has been noted that the house,proposed driveway, and onsite sidewalks will be collected and infiltrated within vegetated areas onsite thereby meeting or exceeding the LID requirements. The new offsite sidewalk will be back sloped downhill to the north to disperse onto adjoining lawn areas as noted on the attached drainage exhibit. The requirements of BMP T5.13: Post-Construction Soil Quality and Depth for lawn areas P.•1Projects1170201DOCSOrainageMemo 11.15.17.doe 7 disturbed duringconstruction and lawn areas receivingsheet flow from the drivewayand sidewalk areas as noted on the site plan exhibit. Minimum Requirement#6-Runoff Treatment Runoff treatment is required for all Pollution Generating Pervious and Impervious surfaces (PGPS and PGHS). Per DOE Volume I, Section 2.5.6 this project is not required to provide Stormwater Treatment as the total PGHS is <5000 sf and the PGPS is < 3 -acre The only pollution generating surface proposed it the driveway areas for this project, as roof runoff is considered non-pollution generating. The proposed driveway surface is to be constructed with a cross slope to direct runoff waters to disperse onto adjoining vegetated areas where there is sufficient width of vegetation to provide the 91St percentile storm runoff sufficient contact time to provide water quality before being discharged from the site. #7—Flow Control As previously noted per DOE section 2.5.7-Minimum requirement #7-Flow Control, a project is exempt from providing flow control if the project is: 1) The project has less than 10,000 square feet of effective impervious surfaces, 2) The project converts less than 3/ acre of vegetation to lawn for landscape (or converts less than 2.5 acres of native vegetation to pasture), and 3) Through a combination of effective hard surface and converted vegetation areas cause less than a 0.10 cubic feet per second increase in the 100-year flow frequency as estimated using the WWHM model. Since this project has shown that both the roof and driveway have sufficient area infiltrate, based on the WWHM software analysis which makes these areas classified as "ineffective impervious area" (per the definition of"Effective Impervious Surface" (DOE Manual Volume I-Appendix G). Therefore this results in the project having less than a total of 10,000 square feet of "effective impervious surfaces". In addition the runoff increases less than 0.10 cfs during the 100-year flow frequency based on the WWHM model therefore this project is exempt from providing runoff control as noted. #S-Wetlands Protection There is no discharge proposed from this site to any wetland. #9— Operations and Maintenance Operations and Maintenance of infiltration trench will be the responsibility of the property owner and shall be performed per 2012 DOE Volume III-Page 3-93 or Volume V-Section 4 No. 2-Infiltration attached at the end of this report. P:1Projects4170204DOCS\DrainageMemo 11.15.17.doc 8 STORMWATER EXHIBIT FIGURE I-2.4.1-FLOW CHART FOR DETEMINING RQMNTS FOR NEW DEVELOPMENT DOE DEFINITION OF EFFECTIVE IMPERVIOUS SURFACE INFILTRATION TRENCH DETAIL DOE INFILTRATION TRENCH MAINTENANCE INFORMATION P:IProjects1170201DOCSIDrainageMemo 11.15.17.doc 9 STORMWATER EXHIBIT FIGURE I-2.4.1-FLOW CHART FOR DETEMINING RQMNTS FOR NEW DEVELOPMENT DOE DEFINITION OF EFFECTIVE IMPERVIOUS SURFACE AP ROXIMATE LOCATION OF 46' LONG x 2' WID X 2' DEEP DRAINROCK T FILLED TKENGIi IK NUII tUK KO1)I UK INS, o PER INFILTRATION TRENCH DETAIL F)5ST, 6•CONC.55 ��.W 0 ss ss ss ss SS 5=0.060 ss ti —10A•Y � � •0,00' ts 1 46.00' i 10.00' I— U— t a 70.00' li au II�---ou I !st. ofi; 11° I e, ROOF LINE 1 co I I co a0 � rn 0, I PROPOSED � I W ROFOARA = I WA ; '' 0 3,376 SF) z I ; I W — - — - - —. — II Q1 T-16.50' 8 ' S T : �✓ 3a00 a - W 44 SLOPE 1%MIN ►•0 UN R a aa ° D FiN , +19p °41 1 I/ LOPE1� lS . 104.92' 1 G 2' fiEADER ° 9 ° • e ° BACKW IEW 1 RIH , :20. 0' ., . • ° • 4,.' -I--PROPOSED NEW SIDEWALK (470 SF)+ 4 I -7_ 0 M M 157-1 STREET M 6 _ Z _ w 6 PER THE„REQUIRE TS OF BMP T5.13: 1 POST-CO STRUCTI+N SOLL QUALITY AND DEPTHM M M os M M „ I - FOR-OMR AREA '11571.7REED-DURING - CONSTRUCTION AN+ LAWN AREAS RECEIVING SHEET FLOW FROM THE DRIVEWAY AND SIDEWALK AREAS \ 1.7\----- y 1 1 I _1--M Ravnik & Associates, Inc. SHEET DESCRIPTION: SCAM N.T.S. CIVIL ENGINEERING & LAND-USE PLANNING STORMWATER BY FAN 1633 LINDAMOOD LANB/P.O,BOX 361 BURLINOTON, 98233 EXHIBIT PH:(360)707.2015 FAX:X:p60)707.2216 JOB N0. 17020 DAZE: 11.15,17 Figure I-2.4.1 Flow Chart for Determining Requirement's, fe.,r +P"� Development “lere Does the site have 35% Yes See Redevelopment Minimum • or more of existing Requirements and Flow Chart impervious coverage? (Figure I-2.4.2). No Does the project convert 3/a acres or more of vegetation to Does the project result in lawn or landscaped areas, or 5,000 square feet, or No convert 2.5 acres or more of greater, of new plus ► native vegetation to pasture? replaced hard surface area? t Ves Yet Does the project result in 2,000 'd square feet, or greater, of new plus A I C�d'orniuvuurn Re uirer�nern replaced hard surface area? apply to the new and reptec;ed hard surfaces and cornvevied vc.geta'tion areas. Veg. g. Does the project have land �fJina�rrtu[� eqaaaeement 6 disturbing activities of 7,000 .41 through#S apply.to the new fl square feet or greater? wes and replaced hard surfaces - and the land dietrim'bedi. Vanimuna Requivement#2 applies. c Figure I-2. . 1f -Row Chart for Determining Requirements for - - New Devdopment ; DEPARTMENT OF Revised June2015iFCOL ECOLOGY Please see httpiA'ww.ecy.wa.gov/copyrighthfml for copyright notice including permissions, State of Washington limitation of liability,and disclaimer. 2014 Stormwater Management ll?anual for Western Washington Volume 1 - Chapter 2 - Page 37 Drop structure A structure for dropping water to a lower level and dissipating its surplus energy; a fall.A drop may be vertical or inclined. Dry weather flow The combination of ground water seepage and allowed non-stormwater flows found in storm sewers during dry weather.Also that flow in streams during the dry season. - E - EIS See Environmental Impact Statement. ESC Erosion and Sediment Control (Plan). Earth material Any rock, natural soil or fill and/or any combination thereof. Earth material shall not be considered topsoil used for landscape purposes.Topsoil used for landscaped purposes shall comply with ASTM D5268 specifications. Engineered soil/landscape systems are also defined independently. Easement The legal right to use a parcel of land for a particular purpose. It does not include fee ownership, but may restrict the owners use of the land. Effective Impervious Surface Those impervious surfaces that are connected via sheet flow or discrete con- veyance to a drainage system. Impervious surfaces are considered ineffective it 1) the runoff is dispersed through at least one hundred feet of native vegetation in accordance with BMP T5.30: Full Dispersion (p.939); 2)residential roof runoff is infilt- rated in accordance with BMP T5,10A: Downspout Full Infiltration (p.905);or 3) approved continuous runoff modeling methods indicate that the entire runoff file is infiltrated. Embankment A structure of earth,gravel, or similar material raised to form a pond bank or found- ation fora road. Emergent plants Aquatic plants that are rooted in the sediment but whose leaves are at or above the water surface.These wetland plants often have high habitat value for wildlife and waterfowl, and can aid in pollutant uptake. 2014 Soormwater Management Manual for Western Washington Volume l-Appendix G-Page 157 4 DIA.. RIGID PERFORATED PPE pi FILTER FABRIC 1 , i° , FINISHED GliDE ---------- . _a : I-L_Iran-.ATILL--,. ;','.•,;''.A.:°-•:::"':.'''.1.1:..' ,,,::..t.'„14:',,....-:f',:'all..1.m.LUunTs •. TOP , . --4.uliF-4..•;i:-='• --,..-•,,,, •••,..w4.:.,• --•;.13,-,:...0-pr = '•::::1,`;'••':.;-:1: ^.;',•:',:::::',1=1,-"-= „) •&..S -----,----3:: -.._. ----,, i 1 i . 1 , E,a --,,,, ‘,. ..... ii. ... 1, r„ c,. c, ,;,,, =11,= .N WASHED :ii:,OCK , m—, iii--ait- 1 TRENCH DEPTH • ' -111-11 t". •:,• . -=-_ 111=11 1 _ __-_-, I i BOT7Ohli h -LI- :1 L=Fit=1 1 1_1 i 1 1=...1 1 Tr I ___T , 1 •1 1/7' TO 314' iNFILTRATION TRENCH SVCTION AA WASHED DRA1NROCK ! I . , , 1 ! el,M Mriciltit Ravn.ik & Associates Inc. K.tt. CIVILENCINEERENG CI, LIED.UE PLAMINCi ii;I:i 14 17 1 • 1 , ,,,,,,, ! ( ), •,1 mAtm em MX .... ,. ..,. EEZ YARTME:6170 LAMM FM!IR DUE.MaisAM WA MB ,,,, ,,, .„ '4..„.. M.:WA*7-271ta NM 4 p.',..,14,n4.22,1,g_ ,____, / . . ,.-_, ,, CI:I:41W Ti,',.:1 Yar Ky I ,`,\• ' 11,, IL siT - ' -')'' • 1 , L4L-..4 LNJ‘_,-..,EL - k ,,1, - - . ", .1 eAve 0,MM _____ In facilities such as infiltration trenches where a reduction in infiltration capability can have significant maintenance or replacement costs, selection of a reliable treatment device with high solids removal capability is preferred. In facilities that allow easier access for maintenance and less costly maintenance activity (e.g., infiltration basins with gentle side slopes), there is a trade-off between using a treatment device with a higher solids removal capability and a device with a lower capability. Generally,treatment options on the basic treatment menu are more capable at solids removal than pre- treatment devices listed in Chapter V-6 - Pretreatment(p.955).Though basic treatment options may be higher in initial cost and space demands, the infiltration facility should have lower maintenance costs. Construction Criteria . Conduct initial basin excavation to within 1-foot of the final elevation of the basin floor. Excavate infiltration trenches and basins to final grade only after all disturbed areas in the upgradient project drainage area have been permanently stabilized. The final phase of excavation should remove all accumulation of silt in the infilt- ration facility before putting it in service.After construction completion, prevent sed- iment from entering the infiltration facility by first conveying the runoff water through an appropriate pretreatment system such as a pre-settling basin,wet pond, or sand filter. . Generally, do not use infiltration facilities as temporary sediment traps during con- struction. If an infiltration facility will be used as a sediment trap, do not excavated to final grade until after the stabilizing the upgradient drainage area. Remove any accumulation of silt in the basin putting it in service. . Traffic Control—Relatively light-tracked equipment is recommended for this oper- ation to avoid compaction of the basin floor. Consider the use of draglines and trackhoes for constructing infiltration basins. Flag or mark the infiltration area to keep heavy equipment away. Maintenance Criteria Make provisions for regular and perpetual maintenance of the infiltration basin/trench, including replacement and/or reconstruction of the any media relied upon for treatment purposes. Conduct maintenance when water remains in the basin or trench for more than 24 hours after the end of runoff, or when overflows occur more frequently than planned. For example, off-line infiltration facilities should not have any overflows. Infiltra- tion facilities designed to completely infiltrate all flows to meet flow control standards should not overflow. An Operation and Maintenance Plan, approved by the local jur- isdiction, should ensure maintaining the desired infiltration rate. Include adequate access for operation and maintenance in the design of infiltration basins and trenches. 2014 Stormwater Management Manual for Western Washington Volume Ill- Chapter 3-Page 541 Mo. 2 ifitrr It on Wm inten ance Defect Conditions When tl'deintenance le Resnais Expected When Component Needed Maintenance is Performed General Trash & Debris See "Detention Ponds" (No. 1). 1)k See "Detention Ponds" \a�` (No. 1). Poisonous/Noxious See "Detention Ponds" (No. 1). g ASee "Detention Ponds" Vegetation t'�' 1/./-; (No. 1). Contaminants and See "Detention Ponds" (No. 1). )ASee "Detention Ponds" Pollution il ;l� (No. 1). Rodent Holes See "Detention Ponds" (No. 1). , t I See "Detention Ponds" i `i (No. 1) Storage Area } Sediment Water ponding in infiltration pond after Sediment is removed rainfall ceases and appropriate time and/or facility is cleaned allowed for infiltration. Treatment basins so that infiltration system should infiltrate Water Quality Design Storm works according to Volume within 48 hours, and empty within design. 24 hours after cessation of most rain events. (A percolation test pit or test of facility indicates facility is only working at 90% of its designed capabilities. Test every 2 to 5 years. If two inches or more sediment is present, remove). Filter Bags (if Filled with Sediment and debris fill bag more than 1/2 Filter bag is replaced or applicable) Sediment and full. system is redesigned. Debris 1 / /c'�: Rock Filters Sediment and By visual inspection, little or no water flows Gravel in rock filter is Debris through filter during heavy rain storms. replaced. Side Slopes of Erosion See "Detention Ponds" (No. 1). ` See "Detention Ponds" Pond l\/ /f ' (No. 1). Emergency Tree Growth See "Detention Ponds" (No. 1). See "Detention Ponds" Overflow Spillway NI IA, (No. 1). and Berms over 4 � feet in height. Piping See "Detention Ponds" (No. 1). See "Detention Ponds" (No. 1). Emergency Rock Missing See "Detention Ponds" (No. 1). See "Detention Ponds" Overflow Spillway N / (No. 1). Erosion See "Detention Ponds" (No. 1). See "Detention Ponds" (No. 1). Pre-settling Facility or sump 6" or designed sediment trap depth of Sediment is removed. Ponds and Vaults filled with Sediment sediment. and/or debris Volume V—Runoff Treatment BIVIPs —August 2012 4-34 SOILS INFORMATION STORMWATER INFILTRATION EVALUATION MEMO 7 741 Mama O,We j888ingharn.WA 98225 380133_7318 / 20811,67'Avenue N[ k =�i1 j Aj8npton,WA 98273 988251 5276 368733_7418 August 30,2017 Job No. 17-0425 ended OentFy Homes and Communities 504 East Fairhaven Avenue Burlington,WA 98233 Attn.: Steven i3aughn taco Starmwater Infiltration Evslustoe°r Raffle j,du f evelopmnnt 2202 15th Street Anacortes,Washington Dear Mr. Sangre, As requested, GeoTes't Services, Inc. (GTS) is pleased to submit this report summarizing the results of our storm ater infiltration evaluation associated with the proposed single family residence at the subject property in Anscortes, Washington, as shown on the Vicinity Map(Figure 1). The purpose of this evaluation was to assess the exis`rinng subsurface conditions for use in designing stor`nwater infiltration system(s) associated with proposed development. This report summarizes our conclusions and recommendations regarding the potential for onsite stormwater infiltration. Specifically,our services included the following: u. Evaluation of 3 test pits equally distributed across the subject propo . Test pits explorations were advanced to7.5 feet below the ground surface(BGS). 2. Geological review of the information collected during this phase of the investigation in order to provide recommendations for the project. Our findings and recommendations are summarized in this site-specific report and contain the following information: A site plan showing pertinent existing site features and the approximate location of the explorations accomplished for this project. Logs of our explorations and results of our laboratory testing including a chart illustrating the soil classification criteria and the terminology and symbols used on the exploration logs. Laboratory determinations of soil classification, including the long- term infiltration rates of soil en +entered. Infiltration rates are based on USDA soil gradation analysis, in general accordance with the 2012 onnwatr:r Management fi anual for Western Washington(SMMWW) amende7, December 2014. Leboretory evaluation on collect-.e; soils included USDA sieve analyses and moisture ,•*intents. Poge 9 of 7 GeoTest Services,Inc. August 30,2017 2202 1e Street,Anacortes,WA Job ido. 17-0425 A summary of surface and subsurface soil and groundwater conditions observed at the site during our field exploration. The summary includes descriptions of subsurface profiles and the potential seasonal effects of groundwater. The scope of services for this report included stormwater infiltration only, it does not include geotechniaal recommendations with regards to the planned building foundation support, settlement, potential seismic considerations such as liquefaction and/or other geologic hazards that may exist within this property. PROJECT DESCl OP'TiON We understand that there are plans to develop the subject property with a single-family residence with associated stormwater facilities and utilities. As part of the development, the stormwater facilities will be constructed to accommodate onsite stormwater runoff from proposed impervious surfaces. The attached site and exploration map should be considered preliminary. fall CCORIOl11 WS This section dismisses the general surface and subsurface conditions observed at the project site at the time of our field investigation. Interpretations of the site conditions are based on the results of our review of available information, site reconnaissance, subsurface explorations, laboratory testing, and our experience in the project vicinity. &race Conditions At the time of our visit, the subject property was bordered by single family residences along its western and northern extent and D Avenue and 1 hth Street to its east and south, respectively. The property contained a 2 bay out building near its southwest corner and was covered in a grass lawn. In general, the property sloped slightly downwards towards the north, with elevation changes being less than about 5 vertical feet. Site GeoWay Geologic information for the project site was obtained from the'Washington Interactive Geologic ldiap,"published by the Washington State Department of Natural Resouees (DIN). According to this map, deposits at the project consist of Fraser-Age continental glacial till (0gt).The till is a non-sorted and unstratified mixture of clay, sand pebbles, cobbles, and boulders (diafnicton), deposited by glacial ice. The soils encountered in our subsurface explorations are generally consistent with the published geological information and our experience with projects in the nearby vicinity. Page 2 of 7 GeoTes9 Services,inc. August 30,2017 2202 15°i Street,Anacortes,WA Job No. 17-0425 Saab uEtEce Salt Condition . Subsurface conditions ware explored by excavating 3 test pits (TP-1 through TP-3) on June 27, 2017. Approximate locations of these explorations have been plotted on the Site and Exploration Plan, Figure 2. The test pits were advanced with a tracked excavator to depths of 7.5 feet BGS. After test pit explorations were completed, the pits were backfilled with the excavated soils and compacted with the bucket of the excavator. In general, subsurface soils encountered within the area of proposed development consisted of approximately 0.5 to 1 toot of topsoil (soft, brown, moist, organic silt) that overlays 2 to 4 feet of weathered glacial till loose to medium dense, brown, moist, silty sand to slightly silty sand) with very stiff to hard, sandy silt with pebbles and cobbles (glacial till)extending to full depth within all 3 test pit locations. some minor fill soils were located above the weathered till in TP-2 and TP-3. Please refer to the attached exploration logs for more detail(Figures 4 through 5). Moundtsater Seepage and Seasonet Grottndwater For the purposes of this report, observed groundwater seepage represents either the existing surface of a groundwater table or the surface of perched seepage. The groundwater table is referred to as the atmospheric pressure surface that coincides with the top of the zone of saturation and is the surface that dictates the development design recommendations in this report. Perched seepage is referred to as a saturated zone that develops where a restrictive surface (Le. dense, fine grained sells or bedrock) limits the vertical, downward migration of near-surface water. The groundwater table or perched seepage surface should be considered when determining methods of earthwork construction but is not used to dictate development design, Groundwater Observations At the time of our visit on June 27, 2017, minor, perched groundwater seepage was observed within the test pits between 4.5 and 6.0 feet f3GS. As the region has not, at the time of our site visit, recently experienced precipitation,we interpret the groundwater to be interflow running along the very dense till soils with elevated fines content, generally encountered onsite at approximately 4.5 to 6.0 feet BGS_ During periods of extended and/or heavy rainfall we would anticipate that groundwater would be found perched on the very dense fill soils with elevated fines content. Seasonal Groundwater Fluctuation Observations A distinct mottled horizon or "rust line," was not encountered within the test pit explorations, Mottling (reddish-brown, orange, or yellow splotches or mottles) is typically indicative of soils that experience fluctuating moisture conditions, generally due to seasonal wetting and drying. Gleyed soils, indicative of poorly drained and potentially restrictive soils, were encountered within the unweathered, very stiff to hard till. Gleyed soils are typically gray or bluish-gray in color and the result of a reduced (non-oxidative) soil state caused by Page 3cf7 GeoTest services, ino. August 30, 20'17 2202 15th Street,Anecortes,WA Job No. 17-0425 significant periods of saturation. Gleyed soils are often associated with soils that are restrictive of groundwater flow. Please note that changes to soil color and morphology may take significant periods of time to develop acid may not be reliable indicators of groundwater conditions in areas that have experienced significant recent changes in hydrology. Additionally, in areas of fill, sufficient time may not have passed since fill placement for these indicators to develop. Not all hydric soils exhibit mottled and/or gleyed horizons. Their presence or absence alone should not dictate the interpretation of site groundwater conditions. Sources of groundwater table fluctuations As groundwater table levels and/or seepage rates are typically not static, it is anticipated that groundwater conditions will vary depending on local subsurface conditions, season, precipitation, changes in land use both on and off site and other factors, Markedly, we anticipate that groundwater conditions on site are largely influenced by seasonal variations of precipitation. Considerations GTS considers the depth at which groundwater seepage stabilizes and ponds to be the groundwater table. Groundwater seepage will influence stormwater management facilities and should be considered when designing those facilities. The groundwater conditions reported on the test pit logs are for the specific locations and dates indicated, and therefore may not necessarily be indicative of other locations and/or times. Please consider that groundwater table levels are generally higher (at shallower depths)during the wetter months(October through May). Our construction recommendations consider the groundwater conditions encountered at the time of our field investigation, in association with the project design provided at the time of this report. it is the clients and their (his/her) representative's responsibility to inform GTS of variations in groundwater conditions and/or any modifications to project designs so that a review of and revision to report recommendations can be made, iif necessary. Unless specifically requested, GTS is not responsible to provide monitoring of groundwater conditions beyond the time of our site investigations. Please keep in mind that groundwater conditions may be different if there is a substantial lapse of time between submission of this report and the start of construction. If this is the situation, GTS recommends we be contacted to evaluate groundwater conditions in order to determine whether our report conclusions and recommendations remain applicable. RESULTS Storimater lnfoltratIon Potential Test Pit Gradation Results From the explorations excavated in the areas of interest, 13 representative soil samples were selected and mechanically tested for grain size distribution and calculation .ccording to the 2012 Stormwater Management Manual for Western V✓ashingfon Page 4 of 7 GeoTest Services, Inc, August SO,2017 2202 15th Stt et,Anacortes,WA Job NO. 17-0425 (SMMWW) amend-x' Cte mber 2014, soil grain size analysis meth •, SeclUort 3.3.6. A summary of these results are reproduced in Table 1 below. lest Pit So(! $ 'rl(9le !nlirdrat)on Plate' Bii6cd on 40k. at ElEitEn-w,: <?; Teat Ha Ct o0 ten i2sut®gte Rod uraettmeied RV® Depth 10 ¢�➢ Per AS`iTtn!D622 Shuplifts4 Witt QFaehas{i®aery App lh(tueidl3 tt;;Ft'q TP-1 1.0 SM Weathered Till 9.30 1.51 TP-1 2.0 SF-SM Weathered Till 38.09 _ 6.17 TP-1 4.5 SP-SM Weathered Till 48.08 7.79 TP-2 2.5 SM Weathered Till 9.26 1.50 TP-2 5.0 ML Glacial Till 2.24 Li _ 0.36 TP-3 2.0 SM Weathered Till 11.71 1.90 TP-3 3.5 SP-SM-[ Weathered Till 39.08 6.33 Notes; -Ksat=Initial Saturated Hydraulic Conducilvity -Listed Infiltration rates are estimated 1ong4erm(design)rates based on the soil grain size analysis method. -Carredion Factors Used:CFv m 0.70 In the simplified approach (Section 3.3.4) the infiltration rate is derived by applying appropriate correction ctorrs to the measured saturated hydraulic conductivity (K ) from the ASTM 422 grain size analysis. Saturated hydraulic conductivity is a quantitative measure of a saturated soil's ability to transmit water when subjected to a hydraulic gradient. It can be thought of as the ease with which pores of a saturated soil permit water movement. Saturated Hydraulic Conductivity is expressed as fellows: dcKl�aKJ G 4.57 4. 13001g t CI,t11165t 0.01130e m Where 1310, Deo, and Dso are the grain sizes in mm for which 10 percent, 60 percent, and 90 percent is more fine and flaw is th w fraction of the soil(by weight)that passes the U.S. No.200 sieve. K is measured in cm/sec. With this equation, we can determine the saturated hydraulic conductivity for our representative samples. See example below: Test Pit TP-1 at 1.0 foot BGS: Km 0.006562964 crn/sec or approximately 9.30 inches/hour. Applying correction factors for site variability (0.45), test method (0.4) and degree of influent control to prevent si; ion and bio-buildup (0.9) gives a corrected long term design rate of 1.51 inches/hour for the example at4ve. Based on the 2012 SMMWW(amended December 2014)soil grain size analysis method and our applied correction factors, the weathered glacial till soils located below the topsoil contains estimated long term design infiltration rates ranging between 7.79 and 1.50 in/hr Accordingly, we recommend using the lowest result value of 1.50 in/hr for use in design for the weathered glacial till. Page 5 of 7 GeoTest Services,Inc. August 30,2017 220215"'Street,Anacortes,WA Job No. 17-0425 SioriffiWc F Podluesc is Treatment The storm'-i er facilities on-site may 1"-1uiee some form of pollutant pre-treatment or treatment with an amended soil prior to onsite infiltration or offsite discharge. It is our opinion, based on past experience, that the reuse of onsite topsoil and weathered Outwesh Soils is often the most sustainable end cost effective method for pollutant treatment pure,•,ses. Cation exchange capacities, organic contents, and p1-I of site subsurface soils were determined to establish their pollutant treetersve suitability. Cation Exchange Capacity, Organic Content and pH Testing Three composite samples were collects k during our subsurface explorations for pollutant treatment pu oses. Cation exchange capacity (GEC), organic content (WI), and pH tests were performed by Northwest Agricultural Consultants. Laboraten test results are presented in Table 2. TABLE 2 Czlion Exchange Capacity,Organic Coontent,and pH l41E7aratnry Test Re•.tei1 Vet PEt Saguaple ova Enehea Capacity Oiiaaaale&Montt to i ago Qi (moo SA 21- aq 454 pG7 TP-1 1.5 _ 11.8 6.34 5.6 TP-2 5.0 21.5 7.78 5.5 TP-3 3.5 6.1 3.65 6.8 Criteria SSC-6 states that cation exchange capacity must be greater than or equal to 5,0 roar l i 00 grams and organic content must he a minimum of 1.0 percent for treatment purposes. eased on the results lasted in Table 2, the Topsoil and weathered glacial till appear to be suitable for onsite pollutant treatment purposes based on the SSC-6 of the 2012 Washington State ! partment of Ecology Stonmwater Management Manual for Western Washington. Additional considerations to using infiltration as a treatment option include the soil infiltration rate! drewdown time as described in SSC-4 of the 2012 Washington State Department of Ecology Stormwster Management Manual for Western Washington. A maximum drawdowri time is applied to some types of infiltration based water quality design facilities. L6 lTG TIe•MS The scope of services for this reportincluded stormwater infiltration only, this report is not intended to address other geotechnical concerns with regards to the planned building foundation support, settlement, potential seismic considerations such as liquefaction endlor other geologic hazards that may exist within this property. GeoTest can perform additional geotechnical evaluation and/or analysis, with regards to the a ,eve mentioned geotechnical items, upon request. The analyses, conclusions, and recommendations provided in this report are based on conditions encounters' at the time of the subsurface exploration performed by GeoTest Services, Inc., inf.nation from previous studies and our experience and judgment. Our work has been performed in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing under similar Page 6 of 7 GeoTest Services,Inc. August 30,2017 220215th Street,Anacortes,WA Job No. 17-0425 conditions in this area. GeoTest Services has prepared this report for the exclusive use of Landed Gentry Homes and Communities and their design representatives for specific application to the proposed new development located 2202 t 5th Street in Anacortes, Washington. No warranty, expressed or implied, is made. We must presume the subsurface conditions encountered are representative for the proposed site for the purposes of formulating our recommendations. However, you should be aware that subsuiece conditions may vary with time and between explorat•r locations, and unanticipated conditions may be encountered. If construction reveals differing conditions or the design is modify d, we should be retained to reevaluate our r commendations and provide written confirmation or modification,as needed. We appreciate the opportunity to be of service to you on this project. If any questions should arise regarding this report,please contact the undersigned. Respectfully Submitted, GeoTest Services, Inc. iF' ,f�, . ij - ,424 4 14od ad Tim Millie 1 Tim Chylla, L.E.G. Engineering Geologist Attachments Figure 1 Vicinity Map Figure 2 Site and Exploration Plan Figure 3 Soil Classification System and Key Figures 4-5 Logs of Test Pits Figures 6-7 Grain Size Distribution Northwest Agricultural Results(1 page) ASFE-Report Limitations and Guidelines For Its Use(3 pages) References Interactive Geologic Map of Washington State. Online interactive services provided by the Washington State Department of Natural Resources. Washington State Department of Ecology, 2012 (amended December 2014). Stormwater Management Manual for Western Washington. Page 7 of 7 .:-.1-:_'-'=:-.:Dir:::-=,"-,":40 ' -- ',.,, -• ...-.7,--;.-,-,-.:::::-- .--,,,-. '.1 PROJECT LOCATION ) , . , . '‘. • ..; ,..,, 4r- , .,,-. , . ,',.. ..„..d.-75/ . • , N. :-. , . v,...,h: ,ri. ...I:: •, z.•, 1) .• . i i .• - .• I i 6th 5: :•.- .1 1 1'A 1 , 6-e.1(1 `1.,'Ide•?. 430, i L I tR1 !. , ..... r• 4 .... 1! 14" c a ..5, ••.* . ilh Volunteer Park ) ".• ..1 11 ....' .6.9 cr .,.., I, 2sM7. il , •:, %NOS' 1} i 0).; . "'l C. '1...i'AnaCOrtezi,marin8 r; i .• ::: era otzetii , : Alia,...olle.: Atrport vAtt.. . Lake Park m fi: I-) ,.-...‘ 1 t ;.• P •7'''.,I.S, ... •,'.. ?III z+. ..1 ., ., '`; `:;‹ t4 'J: • 1 -/.., cs ;.' '-;•: • ..., LI •rti)'.' 1'i ..- .-,. li ,,_ : ••:. ii ...,.„71 ... 413 anti..,-,4 kvo Li.K.1,..•A.hi r. I ,..1 "z ,i..• 0: X, .idu y J k'e 1 a . .: 0 • , .: . i ". 41g1•1 : ' $, 4.! MAP REFERENCED FROM GOGGLE MAPS ^i,1 , ..1 F i i : ii ;1 r; ii t• !_ .i r"--- - ---- Date: 8-30-17 By: JS Scale: As Shown, Project i illcDmincy .ctite4p 17-0426 1 I. , 741 Marine L)rive Bellingham, WA 98225 ['PADILLA AU Figure phone: (360)733-7318 2202 'EtiTH STREET i 0'7 "I fax: (360)733,7418 II }: fANACORT , VO ESASHfiRGTON , L . — =__--",---... .... _... _ .— , .. =7.,_.. .:7:7____.,•_7, PROJECT LOCATION i ,, 1; ; . i . _ ,, _ . - .•,, % • 1 . _ • 1 1 f1 •uI . t..," I 1. -. . .,,_ .A." [ ' - --7-'' '- '-' ' — .,:t5 A .* 4" l'-"3' t.-4 . ..- ' ',.., I 0 . i I I 1 4 It , e .., .1 .esa.p ,tisow I i I ) i 1 a pod ' ',i, • i .. I illi ' -ear- . ,• ''''''AI a I. •i _4111111111L- 4 _ 101111 , : I I41111.11164 - I . 1 , 15ti) Street •-• ' [ 1 . I .1 I MAP REFERENCED FROM GOOGLE MAPS , t, I I 1 , I- 1 , 6 1.7i TP4=Approximate Test Pit Location 1. . / A/ ...,_ . — ——,—- RE,61) I 741 Marine DiiVe Bellingham,WA 98225 phone: (360)733-7318 2202 15m STREET fax: (360)733-7418 ,--- I Date: 8-30-17 i By: JS .,_ Scale: As Shown BITE kk!.10 EXPLORATION PLAN PAULL&Mu ADIACORTE ,WASHICAIGTON Project 1.7-0426 Figure f,-)).6. 1 1 Soil cD )ssi?ic :ton System USCS L f4-JOCK + Y.APMC., LIB t >i iM 1,` POCi'_. r to D a D b 4.).b (,,tJ,t Wet�-graded gravel;gr�avdfssnd rrnttiure(s); iithe or no fines GRAVEL GRAVEL AND CLEAN • in,� ri -J w GRAVELLY SOiL (Little or nolri—) 0 0.o.v.o•v Gr e a C @ N o o.o o p Poorly graded gravel;grave land i ixture(s);little or no fines t) m (More than b0°10 of r e , , cr li g rasa fraction rc Yaineci GRAVEL WITH FINES .. P , G h'r Silly gravel;gravell.,ardts.it mixture(s) W E Tit , (Appreciable amount of , -r '/.?L.,,: t O on HQ,4 sieve) �'tI �t? 3� iStres ____ r °�� Clayey ravel;gravel/sand/day mixlur s � } � � f �� Y'Y gravel;� c Y � ) l(. c SAND AND CLEAN SAI 3D SAfln We Al-graded sand;greveiiy sand;friue or no fin o 2 SANDY SO1 (Little or no fines) • •• • SEP Poorly graded said;grave0y sand;little or no finesrtt 0 (Mare than 60%o; •`r I i of Silty sand; sandtsiii rr irtture(s) cosrse fraction passcJ SAND WITH FINES 1 through No. 4 sieve) (,�oprc'iabik amount of :,~ " ' /j /l ACC Uayey end; s,ndtday ntiture(s) fire,) , ;I, 4.� — i� f r ,•,I Inorganic silt and very fine sand; rack flour;silty or clayey fine T,; i 1 ' I' Gi i -_ �, SILT AND CLAY �. ) ;�� J! � sand or rlay;±y�'rt vAth slight p!aslici3Y O 2 7f,.,7 Innr anIc day or Cowl°medium plasticity; grove',ly day;sandy ® E (Liquid limit 1-t<s than 50) / / ;;I Cyf day;silty day;lean day W Q d 2'se ( f= Organic sift;oceanic,slatyy ofto r pAestiraty - iEl Inorganic add;micaceous diatomaceous sand or diatomaous fine C m SILT AND CLAY _ 7U o D CI Inorganic day of high plasticity,fat day E (liquid flrrrt greater tan 50} 0 ry rii u Organic day of medurn to high plasticity; organic silt HIGHLY ORGANIC SOIL ,., ," PT Peat; humus swamp soil'nth high orgenlc content it PNG LE E OT6`-'eP 1MATERIALS MiricI MOL Vr 'E kC' OL flfP CML DEriCR11, 1fLDh\,Si PAVEMENT [01"1100' 1h,C; or PC Asphalt concrete p;vemstri or Portland crxnetl7 pavement ROCK led'a Rodc(Sea Rock Gassirficafian) WOOD no Wood,iumb .,wood chips DEBRIS � Construction debris,garbage .C.i i !n / Notes: 1. Soil descriptions are bared on the general approach presented in the Standard Practice for Description and fdenfifcafion of Soils(Visual-Manual Procedure), as outlined in ASTM D 2488.Where laboratory index teeing has b.-en conducted, soil classifications are based on the Standard Test Method for Classification of Soils for Engineering Purposes,as outlined in ASTiVI D 2467. 2. Soil description ternriindogy is based an visual estimates(in the absence of laboratory test data) of the percentages of each soil type and is defined as follows: Primary Constituent >50%-"GRAVEL,"„SAND,""SILT,'"CLAY,"etc. Secondary Constituents: >30%and<60%-"very gr€vc y,""very candy,""very diiy,"etc. > 12%and<30%-"gravelly,""sandy,""silty,"etc. Ado fio;ral Constituents: > 5%and<12%-"sfighl y gravelly,""slightly sandy,""slghtly sRty,"sic. < 5%-'trace gravel,""trace sand,"`trace silt,"etc.,or not rioted. Dril ing and Sampling Key Field and Lab Test Data _SAMPLE NUMBER 2 INTERVAL. SAMPLER TYPE Code Description Code Description 1 Sampe ident1ficlion Numbera 3.26 inch O-D., 2.�ta roar I.D.Split Spoon PP=1.0 Packet Pen tromL(Er,tat" b 2.t10 inch O.D„ 1.50)rrch Y.D.Split Spoon TV=0,5 Tosvane,tsf vim~ Recovery Depth Interval a Shay Tuna MD= 100 Photoioniz,etion Detector VOC screening,pprm 1 •� 1 Sample Depth Intsnr�> d Groh Sample W=10 Moisture Content, % 1 , a Other-See text if epplica s!e D= 120 Dry Density,pcf Portion of Sample Retained 1 300-th Hammer,30-inch Drop -2eo=61) Materiat smear than No.200 sieve, for Archive or Analysis 2 140-o Returner,30-inch Drop GS Grain Size-See separate figure for data 8 Pushed Al_ Atterferg limits-See separate figure for data 4 Other-See text if applicable GT Other Geotochnir.- .Testing Groundwater CA Cherries Analysis Q Approxinzte water e vetion at time of driCing(AID)or on date noted. Groundwater ATD levels can fluctuate due to previpitaaori,seaso»sl cong3ttorrs, and other factors. II i Padilla AdU 11 11 Figure 1_,„=......____,....,..,...._,..._=_•% ' { r, 31 2202 15th Street Sell Cass leaden System and Key sAnscor es, V V shingtorl t �_�Z____-_- _ ..-.-... -...-.3 -=oa. II,--.. "----.."_----v. ...=7-- f_:��C----t-.--r-----��—Lj----as i -. - ._ - _ _ _________- - z:---, Si F PL.E DATA SOUPS b—r4' B`CLF= 4Z r1� `b8 'nDSsFeATER 64 Co ° 6 Tracked Excavator E Q. E .o Excavation Method: ,_ m u (n Ground Elevation(Yt): Unknown -C Ca,a) O. 0 ..0 U o m sa a) �*0 i- 0 D —o . .555 01. Sc'1,bruin,moist,organic SILT(Topsoil) 1-1J- d { • Sf>n Loose to medium dense,grown,moist,very pity 1-2 _'- d G5 } to silty,fine SAND(Weathered fill) _ 2 1-3 - d GS t slit content decaeascc,becomes coarse to fine SAND 9 —4 . 1-4 1 d GS 1 r - 1-6 J_ d , t J ML. Very stiff to hard,moist,littlish gray,sandy SILT SlighR a —e i jji ; with pebbles and cobbles(Glade!TO) i J - 1.6 T d 2 - a Test Pit Completed 03/27/17 Total Depth of Test Pit=7.5 ft. a a-- -10 a a. L TP-2 SAIAPLE DATA SOFIL PROFILE iR.U DWATER i ° to 2 4 Tracked Excavator E n'. E ,n Excavation Method: — rg z L 0 >, (ft): Unknown s t v o Ground Elevation p c O. i�f tz ,C ri) F. a. E c E n °- 0 0 0 U)oe co co U' D t] i- . - - a, S DL Loose, ill browns dry,slightly sy,fine sand with -13 2-1 �r"t d z organic (Topsail) _ _ z 1 t SM Loose to medium dense,browns,moist,very silty o —2 tm silty,fine SAND with organics(Fib w 2.2 L d GS i ' ` ' SM Loose to medium dense,brown,moist,very silty i ii f .• t to silty,fine SAND(Weathered Tit) J z, of of. 4 i Q fight c? ML Very stiff to hard,moist,bluish gray,sandy SILT E i with pebbles and cobbles(Gi dal Till) 1N ! 2-si J d GS "1 6 a, -I g! 2-4 d S, 8 • 3' Test Pit Competed 06/27/17 i w Tots;Depth of Test Pit=7,5 ft. 1 0cn ut--1a `! d >' , Notes: 1. Stratigraphic contacts ere based on'Odd interpretations end are approximate. r 2, fteferen a to the text of this report is necessary for a proper understarrd ng cri subsurf'conc6tions. 4 3. Refer-to Soil Classification System and Key'figure for ex lacilion of graphics and symbds. iu Figure �- , e' ` 2202 15th Street Lac; of Test Pit Anaccrtes, Washington C1 of 2) r..eDeL� .�pL2'�_ �'SL•�S_^Y3..f:�av__�—Y_ �a.-_ -.— _ .._ sue-_s.am ....: - �-1: r _.. —TM { { { S1Ltfit4-,E i :t TA 6091. PP OHLf GROLPHDWATE-R • - n a) _a `a Tracked Excavator E I—A E -a Excavation Method: lba`, ai a 0) GtroUnd Elevation (ft): Unknown .c 20 Q ® Z 0 a t1)ca t1) I- 0 = fr d •' SM Stiff,brown,moist,slily,medium to fine SAND r 3-1. FL d GS i 'With gravel and cobbles(Fill) k-2 5 5 OL i,black to bra,moist,organic SILT(Relic 3-2�t 4 d GS I , i Sk SIB \Topsoil) /'— i • Loose to medium dense,brown,moist,very silty o _ { to silty,fine SAND(Weathered Till) o9 , 343 j,i d l I silt content decreased wri _ ! j r _ , silt content increased o -—6 ; d a _ Ti ML Vey stiff to hard,moist,bluish gray,sandy SILT 'g a _ with pebbles and cobbbss(Glacial Till) J`t3 Test Pit Completed 06/27117 Lc i- S r Tots!Depth of Test Pit=7.5 ft. 0 Q r . `-10 5 na.' tt T of 0 D 0 z 16 I a 0 d P u) 5 i 0 Kc I 9I N al 0 s• at w� c{ I UI F , >< Notes: 1. Straiigraphic crnitacts are based on field Interpretations and are approximate. r) 2, Reference to the text of this report is necessary for a proper understating of subsurface conditions. 'a�, 3. Refer to"Sal Clesslfication System and Key"figure for explanation of grehics and symbols. a Padilla Adu i Figure ''i`i CITe' / 2202 15th Street Log of Test pits i Anacortes, Washington ' (2 01 2)_ U.S.SIEVE OPENING III INCfi!E5 U_5.SIEVE NUMBERS I HYDROMETER �' 6 4 6 a_1 6 1 3 4 1 t2.�� 3 6 810 /416 20 30 40 50 60 100140 200 f r I. -1- t I -1',4 -r . --‘'-'.-'t;-- . .k.',;:i 0--,-i\linill IIIM I 1111 I r----''' ll '1,- . idi A iv, Elpilr S�I .__ _ � , III � � 1111 .1 Ai '�11 ,....._ ,,, . III ii i-- - 111-7111111 ' I 1 1 \ ' ' o ..� III , i.-L 1 00 IL , : ,\ 1 1 1 250 I !111E1 II lim 15_,_,. . .,,,,filliiii,„,. �, iw Iiir 1 s,I IN II MI 1I� II 0 P 111 Mall 11iipirmairiII ■!i3.,...ddi p , 1 . 1 �� ritla 1111QI 20_ w111IOU111 111ifN lif : .o. I ■ I 1 i uiummill � - 0 0 0 ' _ Mililli _.__ III 111111111111111__ y - _ hill y 0; 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters P Grave Sand o Cobbles .. .. ., Sik or Clay l; coarse One coarse medium tare IL c}� I g Point Depth C assifcation aPL Pi Cc Cu ,I ti 10 TP-1 1.0 Silty, fine SAND (SM) z kJ TP-1 2.0 1 Slightly silty,fine SAND (SP-SM) 1.43 2.42 En) 1, TP-1 4,5 Slightly silty, coarse to fine SAND with trace gravel (SP-SM) 1.52 535 P c ;( TP-2 2.0 Silty, medium to fine SAND with trace gravel (SM) CV O TP-2 5.0 Very,sandy SILT (ML) %Course %Fine %Coerse %Medium °/,Fine ,b, Fines 8 Point Depth �DS00 l�s,� D5� �;�o Dip Gravel revel Sand Sand Sand oil'jt} TP-1 1.0 4.75 0.tt68 0.137 0.076 0.0 0.0 0.6 4.5 66.5 29.4 R1 TP-1 2.0 9,5 0.197 0.181 0.152 0.081 0.0 0.1 0.2 0.7 91.6 7.4 0 A TP-1 4.5 19 0.776 0.632 0.414 0.145 0.0 5.3 9.1 54.8 23.7 7.1 3 ''4" TP-2 2.0 37.5 0.258 0.191 0.08n I 5.8 - -2.9 3.8 16,1 43.5 27.8 a O TP-2 5.0 9.5 0,079 0.0 0.7 1.4 8.1 30.8 59.0 O 1` C,= D3021(D60.4 D10) To he well graded: I < Cc < 3 and Cu = Ds0JD10 C:u > 4 for GJ4lorCU > 6 for SW . J f �., 1 Padilla A.du Figure c�� .3(7 • f `-`;L 2202 i tith Street Size Test Data ti I. Anacortos, WasNngton Grain ' - ,���------ i I U.S. SIEVE OPENING IN INCHES I U.S.SIEVE NUMBERS 1 HYDROMETER 4 2 1 1/2 3 G 10,. d4 20 40 60 1�;0 16 30 60 100 200 _— — _- G 3 .b r'l arp . 8` - ill i :11. i II imi _ i iii , i L ir __ , . , _-_- i . . , c ik i ll! :!IIjL. 11711111111164111111II� ■� ■ I ■ I _ 11111111_,,,, 1 ,,, _, IIII IN ;50;-■■ 1 1■■ I :: iriiiia1u ■ 1 it! I•I _ ■ _i 20IT.,, ......,... I ' �I1IflUU__ 1111111___ -._1I■ _ II 1 1I !! iiOiiFki1iiiIIii! .■r 111 r■■ 1, 1 ■■ .'l . r■_ 1111■■ _ _ _IIIIIIIIIII _ a i 100 10 1 0.1 0.01 0.001 ..5Grain Size in Millimeters Z ; 1 Grevet Sand Cobbles Silt or Clay coarse fine coarse medium fine 6 [ Point Depth Classification LL PL P! CC C a'CI TP-3 2.0 Silty,fine SAND (Sate) L�C'JI TP-3 3.5 Slightly silty, coarse to fine SAND with trace giravel (S.P-Slvi) 1.05 4.58 6 A ____� ti� u —,- _ I %Coarse %Fine %Coarse %Medium °]n line: uJ p i Point Depth a�co I_ Dsa DsoD-30 Di() CraWd Gravel Sand - --Sand Sand /o!-Ines ,; a 0 TP-3 2.0 9.5 I 0.182 0,150 0.089 0.0 0.0 0.2 _ 2.6 72.6 24.6 1 IA TP-3 3,5 19 0. 9 0.367 0.239 0.109 0,0 9.6 9.4 2,1 50.0 7.0 ri w —o of II hl i ;_`i ` ,U D30/( )/eon Diu) To be well graded: I < Cc �. 3 end r. , L �� Padilla Adu Figure , } t7` , _ i. 2202 15th Street Grain R4 t T fin rove , Washington ii i� i�-r:`L:3 ..Id•5.::.- ] -_........_.�.fomi.L�L-sl'i.YYLiva�rs CT.F�:'i v�Y.� _.. --__�—.• — .. - GeoTest Services inc. 741 Marine Drive Bellingham,WA 98225 2545 W Falls Avenue PAP-Accredited Kennewick,WA 99336 509.783,7450 t• Report:41439-1 www.nwag.com lab@nwag.com NAP t DPW:June 30,Z017 Project l o:17-0425 Project Name: Padilla Adu • Sample ED PH Organic Matter Cation Exchange Capacity TP-1 @ 1.5' 5.6 6.34% 11.8 meq/100g TP-2 @ 5.0' 5.5 7.78% 21.5 meq/100g TP-3 @ 3.5' 6.8 3.65% 6.1 meq/100g Method S$ d 4•300-€„I*0 ASTM D2974• EPA 9081 REPORT LIMITATIONS AND GUIDELINES FOR ITS USE' Subsurface issues may cause construction delays, cost overruns, claims, and disputes. WhIle you cannot eliminate all such risks, you can manage them. The following information is provided to help: Geotechnical Services are Performed for Specific Purposes, Persons, and Projects At GeoTest our geotechnical engineers and geologists structure their services to meet specific needs of our clients. A geotechruicel engineering study conducted for a civil engineer may not fulfill the needs of an owner, a c•nstruction contractor or even another civil engineer. Because each g=otechnicel engineering study is unique, each gaotechnical engineering report is unique, prepared solely for the client. No one except you should rely on your geotechnical engineer who prepared it. And no one--not even you—should apply the report for any purpose or project except the one originally contemplated. Read the Full Report Serious problems have occurred because those relying on a geotechnical engineering report did not read it all. Do not rely on an executive summary. Do not read selected elements only. A Geotechnical Engineering Report is Based on a Unique Set of Project-Specific Factors GeoTest's geotechnical engineers consider a number of unique, project-specific factors when establishing the scope of a stuu•i. Typical factors include: the clients goals, objectives,and risk anagement preferences; the gene,:I nature of the structure involved he size, and configuration; the location of the structure on h,e site; and other planned or existing site improvements, such as access roads, parking lots, and underground utilities. Unless GeoTest, who conducted the study spclf t illy states itherwise, do not rely on a geotechnical engineering report that was: a not prepared for you, e not prepared for your project, a not prepared for the specific site explored, or • completed before important project changes were made. Typical changes that can erode the r:liability of an existing geotechnical engineering report include those thet affect: the function of the proposed structure, as when it's changed,for example, from a parking garage to an office building,or from a light industrial plant to a refrigerated warehouse, o elevation, configuration,location, orientation, or weight of the proposed construction, • alterations in drainage designs;or a composition of the design team; the passage of time; man-made alterations and construction whether on or adjacent to the site; or by natural alterations and events, such as floods,earthquakes or groundwater fluctuations;or project ownership. Always inform GeoTest's geotechnical engineer of project changes — even minor ones m and request an assessment of their impact. Geotechnical engineers cannot accept responsibility or liability for problems that occur because their reports do not consider developments of which they were not informed. 'information in this document is bases upon material developed by ASF ,Profsssfonri Fiats Practicing in the Geosciences(©sie.org) �c>ra oeorf'sT Subsurface Conditions Can Change This geotechnical or geologic report is based on conditions that existed at the time the study was performed. Do not rely on the findings and conclusions of this report, whose adequacy may have been affected by:the passage of time; by man-made events, such as construction on or adjacent to the site; or by natural events, such as floods, earthquakes, or groundwater fluctuations. Always contact GeoTest before applying the report to determine if it Is still relevant. A minor amount of additional testing or analysis will help determine if the report remains applicable. Most Geotechnical and Geologic Findings are Professional Opinions Our site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoTest's engineers and geologists review field and laboratory date and then apply their professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ—sometimes significantly—from those indicated in your report. Retaining GeoTest who developed this report to provide construction observation is the most effective method of managing the risks associated with anticipated or unanticipated conditions. A Report's Recommendations are Not Final Do not over-rely on the construction recommendations included in this report. Those recommendations are not final, because geotechnical engineers or gel*Oats develop them principally from judgment and opinion. GeoTest's geotechnical engineers or geologists can finalize their recommendations only by bserving actual subsurface conditions revealed during construction. GeoTest cannot assume responsibility on liability for the report's recommendations if our firm does not perform the construction observation. A Geotechnical Engineering or Geologic Report may be Subject to Misinterpretation Misinterpretation of this report by other design team members can result in costly problems. Lower that risk by having GeoTest confer with appropriate members of the design team after submitting the report. we suggest retaining GeoTest to review pertinent elements of the design teams plans and specifications. Contractor. can also misinterpret a geotechnical engineering report. Reduce that risk by having GeoTest participate in pre-bid and preconstrucaion conferences, and by pro/Wing construction observation. Do not Redraw the Exploration Logs Our geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors if omissions, the logs included in this report should never be redrawn for inclusion in rchit:cturl or other design drawings. Only photographic or electronic reproduction is acceptable; but recognizes that separating logs from the report can elevate risk. Give Contractors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnir engineering report, but preface it with a clearly written letter of transmittal In that letter, consider advising the contractors that the report was not prepared for purposes of bid development and that the reports accuracy is limited; encourage them to confer with the GeoTest and/or to conduct 'Information in this document Is based upon material developed by ASF£,Professional Firms Practicing in the Geosnees(aete.arg) .deer additional study to obtain the specific types of information they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might you be in a position to give contractors the best information available, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. In addition, it is recommended that a contingency for uilanticipated conditions be included in your project budget and schedule. Read Responsibility Provisions Closely Some clients, design professionals, and contractors do not recognize that geotechnical engineering or geology is far less exact than other engineering disciplines. This lack of understanding can create unrealistic expectations that can lead to disappointments, claims, and disputes. To help reduce risk, GeoTest includes an explanatory It ' :ations section in our reports. Read these provisions closely. Ask questions and we encourage our clients or their representative to contact our office if you are unclear as to how thee provisions Apply to your project. Environmental Concerns Are Not Covered in this Geotechnical or Geologic Report The equipment, techniques, and personnel used to perform an environmental study differ significantly from those used to per(tirrn a geotechnical or geologic study. For that reason, a geotechnical engineering or geologic rIport does not usually relate any environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated containments, etc. If you have not yet obtained your own environmental information,ask your geotechnical consultant for risk management guidance. Do not rely on environmental report prepared for some one else. Obtain Professional Assistance to Deal with Biological Pollutants Diverse strategies can be applied during building design, construction, operation, and maintenance to prevent significant amounts niologiml pollutants from growing on indoor surfaces. Biological pollutants includes but is not mit to molds, fungi, spores, bacteria and viruses. To be effective, all such strategies should be devised for the express purpose of prevention, integrated into a comprehensive plan, and executed with diligent oversight by a professional biological pollutant prevention consultant. Because just a small amount of water or moisture can lead to the development of severe biological infestations, a number of prevention strategies focus on keeping building surfaces dry. While groundwater, water infiltration, and similar issues may have been addressed as pari of this study, the geotechne el engineer or geologist in char.fe of this project is not a biological pollutant prevention consultant; none of the soMcea preformed in connection with this geotechnical engineering or geological study were designed or conducted for the pu ;time of preventing biological infestations. 'Information in this document is based upon material developed by ASFE,Professional Finns Practoing in the Geosderma(voe.org) eff`-‘v 1,4,ere 6eccrese i GeoTest Services, Inc. October 24, 2.017 2202 15th Street., Anacortes, WA Job No. 17-0425 We appreciate the opportunity to be of service to you on this project. If any questions should arise regarding this report, please contact the undersigned. Respectfully Submitted, GeoTr st Services), into r ("'" w , ` � frgi�2tns�g G<ologot v,Cb 24.20 4 i Tim Chylla�I Tim Chylla, L.E.G. Engineering Geologist At-W.chriraen Figure 1 Vicinity Map Figure 2 Site Plan Refewenceg Washington State Department of Ecology, 2012 (amended December 2014). Storrnwater Management Manual for Western Washington. Page 2 of 2 741 Menne Drive Bellingham,WA 98225 350 733_7318 20511-87'"Avenue NE G'� J �� . Arnnglan,WA 98223 888 2l 52/6 360 733_7416 October 24, 2017 Job No. 17-0425 Landed Gentry Biomes and Communities 504 East Fairhaven Avenue Burlington,WA 98233 Attn.: Steven Baughn Re: StonroveR?tor lnfBtTetten Eeaaludion Memo Padilla:ADU Development 2202 15t' Street Anacortes,Washington Dear Mr. Baughn, As requested, GeoTest Services, Inc. (GTS) is pleased to submit this memorandum disusing the effects of stormwater from the proposed infiltration trench on the adjacent residential foundations. It is our understanding that the City of Anacortes Planning Department has concerns that the foundation setback distances from the trench might not meet the suggested guidelines put forth in the 2014 DOE Storrnweter Manual for Western Washington and may have 'a significant negative impact on the surrounding foundations'. The manual suggests that infiltration trenches be placed at least 20 feet from uphill foundations and 100 feet away from downhill foundations. The proposed infiltration trench is to be situated 20 feet north of the proposed residence on the subject property and runs east to west for 46 feet. The existing residence on the neighboring property to the north is 48 feet away from the proposed infiltration trench. Topography on the property slopes gently downward to the north, dropping approximately 1 foot in elevation from the trench to the neighboring residence, giving a gradient of 1 degree or 2 percent. Based upon the relatively flat topography end the fact that the upper 4 feet of the existing site soils contain weathered till that can be infiltrated into at a rate of 1.5 inches per hour, in our opinion, it is extremely unlikely that the location of the proposed trench would negatively impact the surrounding foundations. Page 1 of 2 i PROJECT LOCATION ,,. .,- .1 1 I 1 , . . ' 6,14i 14. I ', -'• , 1 ::. : I - I a s . , I • c•-. :-,`;-.1 `",?, 'X,- , I -..• , or , 1 = -, ••- A li / ,•:= , , , ,o ? , , .•,- • 1 1 , I MAP REFERENCED FROM GOGGLE MAPS 1 •, ,., 1 ___. Date:8-30-17 By: JS Scale: As Shown Project :: , MOTES!REEtqCES„ IINC. VICINITY MAP 17-0426 II 1 741 Marine Drive Bellingham,WA 98225 PADILLA ADU Figure 1 phone: (360)733-7318 2202 16TH STREET fax: (360)733-7418 4; ANACORTES,WASHINGTON i - 4 - — I - — it :� • D �. uc -� . rRZ ' . ,.. - UfS iJ 6•i.- :�L.c, .• .• . . M1J 1 ..y:: I ♦ I � IIr S4` 12 AN0 20, Or &OC+f gat AS PER SiIRVrr Ti£CORPEL' 3 WAA •h;.r^3 t.lC+T�•5 » !.clA3 ..''ri6ray. . 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IL ` '. . .'-' _ . ,i•�w,n.rtr..r n v�riw i�rr - •.�.-�• _. ,c-i• • PADILLA DU or P.' o•1•1..ry ..y a.Iwr•.q.i y.rw u.V W.I - - ff f,1• if taiN ��r . . ST V W9: GARAGE CENTER� •1..n^A. !.i`7." :.-' k ._ r%J l 1•.,•e•nw• - - �1:_ - L•r. ' ' jA GF�.Rn•'�G V Y•s-.• r. a•.x.1.r�+- I OL PLAN SS"TE �xy+sF m p(SVENAV / lbac+m• RIS OF MB — EROSION CAGE CE TER - SAJr slco > PLASTICmscp wsmc RucPs �,o,—. 8 L4D IMPROVEMENT PLAN • ei xs aa"st�`rc"°" SLOPED ioo-a�`T E l e:>�un,>,as°Ksurt�c�a" OVEM . Erg _ 517E -otYPeAsgalFttT oursi .. SITE„,,�. m �� — pFEassob 220215TH STREET i s-n-t STREET ,.+�,arw pdVACOR7E5, WA 1 ,;.ve.: t' 1raa�t- �ws:c' ave. vLatoran rr ,... P56250 Lc 4 .,1�. :Jena: g� f. i,`a i�yp17 �l 'y,R. s:� =�" 1 of 2 ....--11 i' � — - — - — --- _ _ _n __ � .La......�,., ,- .... � - _ _ _ __ . _ - .— _ .�_1_- _ .,1 rf.L5R_c,;;_T Q LEGAL OESCPPTLhQN: 4 € I :n , CAST ,mu Or LOT 17, ALONG VA1R A! , OF LOTS T$ 1 = • ; JJI. AVO 20. 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P56250 220215TH STREET 1 Age. , ss.•F. 1 rva•n ANACORTES, WA II I _ PLATOF-4NORTH' I, txt Cris Y - LG — 1 Iu .a It ..CtA. ••__-_ III xe tareroT! �� ., I y'T' I - - --- -- 1 oft HOUSE-WWHM VIEWS AND REPORT INFILTRATION TRENCH DETAIL DOE INFILTRATION TRENCH MAINTENANCE INFORMATION INFILTRATION TRENCH WITH 4-INCH PIPE-VOID RATIO CALCULATION \---\--'0 (A, 5 e______,. i WWHM3 wwhm3House2 ile Edit View kb._ fib' IC. ll _ _ Ir- themat I11'c Basin 1 Predeveloped SCENARIOS Subbasin Name: Basin 1 FrPredeveloped i -- i Surface lnterflow Groundwater - ; -;-- - Flows To ,q_ r Mitigated ^_ F Area in Basin Id Show Only Selected Run Scenario l Available Pervious Available Impervious m ' Fr- C Forest Flat .077 Fe- ROOFTOPS FLAT ! 0 t=l FMFNTS 1--- Irar t i! Ft. , ,‘, ,,, t—i:i . ) .,v ______ . imma f , • • r_ ______-__.1._-_- Move Elements ' I -111 PerviousTota 0.077 Acres Impervious Total 0 I Acres - , r= ' i T i l Basin Total 0.077 I Acres Save xy I Load xy d I -- _________-- --- --- - '< 140 __-i 12 Deselect Zero i Select By: 1 GO I 1":.,.. III . i 10 cv , al:, ,, ai..1,1 ..„ , ,. , ivx ..,.....2 w3 1 , , ,_ . ,, or_ x] pi, _ .. .3_ __ _ , sir \---k-ouse_, WWHM3 wwhm3House2 ile Edit View Help fa',' iM' •�� IIre -.Alb_ ILL2:1 M L hi._ -----.... ; 4-taAlsir,%411/4*- . - 7 7 r,=1- I CVii 1 ''.. 10.?-u'.°‘. ' lin , ; chesr+at:c - W Basin 1 Mitigated SCENARIOS 1 - _ Subbasin Name: Basin 1 F_ Designate as Bypass for POC: 11- Predeveloped "1 Surface Interftow Groundwater ! __ . Flows To : Gravel Trench Bed 1 Gravel Trench Bed 1 i✓Iviitigated l ( - • Area in Basin Show Only Selected _Run Scenario 1 i I Available Pervious Available Impervious N FI FM FNTS w --- -- -- (v C,Forest Flat I {0 F ROOFTOPS FIAT 1 t077 low __ .- i ,czi . -. u I ' • ---• I � Move Elements • • -i II ` i PerviousTota 0 Acres Impervious Total 0.077 Acres J; ___J ! i Basin Total 0.077 Acres Save xy Load xy - _____-_.-.- -_ - ► .1 _._-._._..,-_..: .,•_. - -- __ - --_ ----___ - ----- ,C (40 i �12 -- Deselect Zero I Select By: i __ GO I _ . -- -- .. _ _v--_ -vie. J WWHM3 wwhm3House2 ile Edit View Help - - -- - - - ------ MI--- '7*'''07..11--'4*r . . Iiii i Frill------ Ilk- M:11. Mill chernatic ; SCENARIOS ; ElGraver Trench Bed 1 Mitigated i` — ' Facility Name Gravel Trench Bed 1 I I f I-Predeveloped i I I Outlet 1 Outlet 2 Outlet 3 ; ; Downstream Connection 0 10 0 P Mitigated j 1 I ' ; Facility Type Gravel Trench/Bed Run Scenario I , r Precipitation Applied to Facility Quick Trench I FI FMFNTS ----;--- -- --f i r-- vapomtionApiiedtOFaalii 2d _ W Facility Bottom Elevation (ft) 0 I,,=, ,, ' F I jr� I Facility Dimensions s i 4 L�- Trench Length '46 Outlet Structure -�� Riser Height(ft) .IC ,..1 LEoiai `, i Trench Bottom Width 2 Effective Total Depth i3 Ri:: t r 61 W "71 Mi. leirT i I I Bottom slope of Trench 0.000001 Type (Flat :y :::;2 '---- , . Left Side Slope 0 Notch Type D Right Side Slope 0 1 - I- �`""- Material Layers for Trench/Bed Layer 1 Thickness ft 2 i 1 y ( ) _ —�1 Orifice Diameter Height QMax Layerl porosity 0.39 ! Number (In) (Ft) (cfs) ---- j Layer 2 Thickness(ft) 0 , Layer 2 porosity I 2 r0"-'- I 10 Q Layer 3 Thickness(ft) (0— `- 3 la— 1I � fa— • Layer 3 porosity 0 Move Elements ! Infiltration 11YES i Trench Volume at Riser Head(acre-ft) 002 Measured Infiltration Rate(in/hr) 1i-5--- Pond Increment 010 '-rl , i _ _______IL_____ --"— Show Pond Table [Open Table -I � Infiltration Reduction Factor(infirfactor) 51 '. i I Use Wetted Surface Area(sidewalls) YES { ' t -, Total Volume Infiltrated(acre-fQ 6.836 Total Volume Through Facility(acre-ft) 6.873 "Save xy I Load xy 1 a I - -- _._._ --_ -.. i - ---- I.._.__._. _.____.___...._ _.. Total Volume Through Riser(acre ft) 0.037 Percent Infiltrated 99.46 (40 >' [24.-- _- rn r, \-\"( 0..5 e....., WVJHM3 wwhm3House2 pie Ed€t View Help i .1 _ 1 1 01 P6-ci Pre developed ;`lohr Frequency c 6 10E1 r x x x x x x x x xx xx xxxxxxxxxxoaxxxxxxx - 701lnflow to POC 1Mitigat IFlow(CFS) 0501 0701 0801 I 801 POC 1 Mitigated flow 12 Year = 0.0008 0.0176 0.0000 5 Year = 0.0016 0.0243 0.0000 ! 10 Year = 0. 0022 0.0292 0.0000 125 Year = 0.0031 0.0359 0.0000 ? I 10E 0 150 Year = 0.0037 0.0413 0.0000 i ,I U 100 Year = 0.0043 0.0471 0.0000 i 1 O Yearly Peaks • . I 1949 0 .0029 0.0220 0 .0000 ,; J 10E 1 (f 1950 0.0016 0.0164 0.0000 ! , 1 1951 0.0012 0.0199 0.0000 i l 1952 0.0009 0.0181 0.0000 ! r �^ oo°°o°a°Dove x 1953 0.0004 0.0222 0.4000 A ., ..L_,A4..7G^ . ^ Y X X l 1954 0 .0006 0.0151 0.0000 , 10 E-2 / .. .e----..... 1 10 20 30 40 50 60 70 80 xx 0 99 11955 0.0007 0.0107 0.0000 1956 0.0007 0 .0107 0.0000 , CumulaUve Pvczabi) lty 1957 0 .0012 0.0232 0 .0065 . , ( 1958 0 .0005 0 .0160 0.0000 Durations Flow Frequency [-Water Qualityj Hydrograph ,I Wetland Fluctuation 1 1959 0.0015 0 .0113 0 .0000 1960 0.0008 0.0231 0.0055 Analyze datesets 1 1961 0.0004 0.0136 0.0000 1 PUYALLUPDAILYEVAPWJENSEN-HAISE a 1 1962 0.0000 0.0207 0 .0045 i 2 BURLINGTON PRECIP ! 1963 0.0004 0 .0108 0.0000 1964 0.0007 0.0210 0.0000 IF 111111-Ei 1965 0.0012 0.0479 0.0290 -- 1000 Gravel Trench Bed 1 ALL OUTLETS Mitigated i i 1966 0.0003 0.0136 0.0000 1001 Gravel Trench Bed 1 OUTLET1 Mitigated I 1967 0.0008 0.0336 0.0088 1002 Gravel Trench Bed 1 OUTLET 2 Mitigated I 1968 0. 0017 0.0270 0.0145 ! 1969 0.0004 0.0106 0.0000 All Datasets 1 Flow j Stage l Precip•l Evap POC 1 !I 1970 0.0002 0.0343 0 .0076 �i 1971 0.0019 0.0183 0.0069 Flood Frequency Method , 1972 0.0008 0.0129 0.0000 ' Log Pearson Type III 17B ' 1973 0.0004 0.0153 0 .0000 Weibull , 1 97e2 0 OM 1 0 l51 w9 r1 rnnnt7 r Cunnane I• a 1'i III I - ; , ail . , Western Washington Hydrology Model PROJECT REPORT 4 Project NaTi1e: wwhm3House2 % 40u6e, Site Address: City Report Date : 11/15/2017 Gage . Burlington Data Start : 1948/10/01 Data End 1999/09/30 Precip Scale: 0 . 83 YrNHM3 Version: PREDEVELOPED LAND USE Name . Basin 1 Bypass : No GroundO`a tee•: No Pervious Land Use Acres C, Forest, Flat . 077 Impervious Land Use Acres Element Flows To: Surface Interflow Groundwater Name : Basin 1 Bypass : No GroundWater: No Pervious Land Use Acres Impervious Land Use Acres ROOF TOPS FLAT 0 . 077 Element Flows To: Surface Interflow Groundwater Gravel Trench Bed 1, Gravel Trench Bed 1, Name : Gravel Trench Bed 1 Bottom Length: 4 6 f t . Bottom Width : 2ft . Trench bottom slope 1: 0,000001 To 1 Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer : 2 Pour Space of material for first layer : 0.39 Material thickness of second layer : 0 Pour Space of material for second layer : 0 Material thickness of third layer : 0 Pour Space of material for third layer : 0 Infiltration On Infiltration rate : 1.5 Infiltration saftey factor : 1 Wetted surface area On Discharge Structure Riser Height: 2 ft. Riser Diameter: 552 in. Element Flows To: Outlet 1 Outlet 2 Gravel Trench Bed Hydraulic Table Stage(ft) Area(aer) Volume(acr-ft) Dschrg(cfs) Infilt(cfs) 0.000 0.002 0.000 0.000 0.000 0.033 0.002 0.000 0.000 0.003 0.067 0.002 0.000 0.000 0.003 0.100 0.002 0.000 0.000 0.004 0.133 0.002 0.000 0.000 0.004 0,167 0.002 0.000 0.000 0.004 0.200 0.002 0.000 0.000 0.004 0.233 0.002 0.000 0.000 0.004 0.267 0.002 0.000 0.000 0.004 0.300 0.002 0.000 0.000 0.004 0.333 0.002 0.000 0.000 0.004 0.367 0.002 0.000 0.000 0.004 0.400 0.002 0.000 0.000 0.005 0.433 0.002 0.000 0.000 0.005 0.467 0.002 0.000 0.000 0.005 0.500 0.002 0.000 0.000 0.005 0.533 0.002 0.000 0.000 0.005 0.567 0.002 0.000 0.000 0.005 0. 600 0.002 0.000 0.000 0.005 0. 633 0.002 0.001 0.000 0.005 0. 667 0.002 0.001 0.000 0.005 0.700 0.002 0.001 0.000 0.006 0.733 0.002 0.001 0.000 0.006 0.767 0.002 0.001 0.000 0.006 0.800 0.002 0.001 0.000 0.006 0.833 0.002 0.001 0.000 0.006 0.867 0.002 0.001 0.000 0.006 0. 900 0.002 0.001 0.000 0.006 0. 933 0.002 0.001 0.000 0.006 0.967 0.002 0.001 0.000 0.006 1.000 0.002 0.001 0.000 0.007 1.033 0.002 0.001 0.000 0.007 C� C-- C� C-- C-- C- CO CO CO CO CO CO CO CO co al 01 0) 61 61 al 61 Ol Ol O O O O O O O O O I r-I r f r--I r-I r-♦ r i r 1 N N N N N N N N N M M M M M O O O O O O O O O O O O O O O O O O O O O O O O O 1--1 r-1 r-1 r i r-1 =I r I r-i r-I r-I I--r I--I r I r-I r I r i r i r-I r-i r-I r-i r-! r I %--i r-i r-i O O O O O O O O O O O O O O O 0 0 0 0 0 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 00 J . . . . . 0000 . e Do . . a u a . . . . a . a . ea 0 a . . . a . o 00o . . . . a a . . . . 0000 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C 0 0 0 0 C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O O O O O O O Cr) O O O O O O O O O O O O O O O O O O O k.O r I C� r I co Cs) r 1 N CO M CO co d IS) =1 N co 01 d Cr) C� lO CO in u) O O O O O O O O O O O O O O O O O O O O O O O O O O O O O N r-I r-1 OJ d5 O CO CO N d' . . . . a a a a • a a • ' 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C- [[ a • a . • . • M C� N CO d' r-1 CO I_C) M N r-i O O O r-I N M a a a . . . . a a a . . . . a a a . a . . a a . . . . a a d r I O O O r I Cr) lO Ol r l N d' LI) ( O O N d' C.O CO O C d+ LO CO O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O N C- -I N co d' L C-- CO 6l r-I r-i 1-1 r i r I r-I N N N N N Cr) M Cr) Cr) M d =I =I =I r-I r-1 =1 r I r-1 r i r-i r-1 r-I 1-1 r I r I =I 1-1 r-I r--1 r i r-I r I N N N N N N N N N N N N N N N N N Cr) Cr) M M M Cr) M M M M M M CO M di d' d' O O O O O O O O O O O O O O O O O O O O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N 000000000000000000000000000000000000000000000000000000000 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 0 0 0 0 . a a o . a a a . a . . . . a a . a . a . . a . . . . . a a a . a a a a . a a a a a . . . . . . . a . . . . a o e CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC00 r- O co I— O M I` O M O O Cr) O Cr) O Cr) O M t` O Cr) t` O M t` O Cr) O Cr-) O Cr) O Cr) O M O Cr) O Cr) O Cr) O Cr) LO O Cr) LO O M O Cr) lO O Cr) O lO O M O M lO O M l0 O Cr) lO O Cr) lO O M lO O M <-O O M lO O M LO O CO k-O O M l9 O M lO O M O r•1 r-1 r-I N N N M M Cr) d' d' di in ISM L LO r- r- CO CO CO Ol Ol 61 O O O '-i r I r i N N N Cr) M Cr) dy d+ d Ln if) cc CD CD C-- r- co CO CO 61 dl . 0 a . . a a . a . . 0 a a a . . . . . a a a . . a a . . . . . . a . . . 60 Do . . . . a . Oe . . a . . r-I r-i r-i r-1 r I r I r I r i r--I r-i r-I r-I r-i r-i r--{ r-I N N N N N N N N N N N N N N N N N N N N N N N N N N N N N 2. 967 0.002 0.004 425.8 0.013 3.000 0.002 0.004 448.0 0.013 MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.000768 5 year 0.001605 10 year 0.002242 25 year 0.003085 50 year 0.00372 100 year 0.004346 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.003 0.000 1951 0.002 0.000 1952 0.001 0.000 1953 0.001 0.000 1954 0.000 0.000 1955 0.001 0.000 1956 0.001 0.000 1957 0.001 0.000 1958 0.001 0.006 1959 0.001 0.000 1960 0.002 0.000 1961 0.001 0.005 1962 0.000 0.000 1963 0.000 0.005 1964 0.000 0.000 1965 0.001 0.000 1966 0.001 0.029k' 1967 0.000 0.000 1968 0.001 0.009 1969 0.002 0.015 1970 0.000 0.000 1971 0.000 0.008 1972 0.002 0.007 1973 0.001 0.000 1974 0.000 0.000 1975 0.002 0.000 1976 0.007 0.022 1977 0.000 0.009 1978 0.000 0.000 1979 0.001 0.010 1980 0.000 0.000 1981 0.001 0.000 1982 0.001 0.000 1983 0.002 0.000 1984 0.001 0.000 1985 0.002 0.006 1986 0.000 0.000 1987 0.001 0.000 1988 0.001 0.000 1989 0.002 0.018 1990 0.001 0.000 1991 0.001 0.000 1992 0.002 0.006 1993 0.001 0.000 1994 0.001 0.000 1995 0.000 0.000 1996 0.000 0.000 1997 0.001 0.007 1998 0.003 0.016 1999 0.001 0.000 2000 0.000 0.000 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0067 0.0290 2 0.0029 0.0219 3 0.0029 0.0177 4 0.0024 0.0160 5 0.0020 0.0145 6 0.0020 0.0100 7 0.0019 0.0088 8 0.0017 0.0086 9 0.0017 0.0076 10 0.0016 0.0069 11 0.0016 0.0068 12 0.0015 0.0065 13 0.0013 0.0062 14 0.0012 0.0056 15 0.0012 0.0055 16 0.0012 0.0045 17 0.0012 0.0000 18 0.0009 0.0000 19 0.0009 0.0000 20 0.0009 0.0000 21 0.0009 0.0000 22 0.0008 0.0000 23 0.0008 0.0000 24 0.0008 0.0000 25 0.0008 0.0000 26 0.0007 0.0000 27 0.0007 0.0000 28 0.0007 0.0000 1 29 0.0007 0.0000 ' 30 0.0007 0.0000 31 0.0007 0.0000 32 0.0006 0.0000 33 0.0005 0.0000 34 0.0005 0.0000 35 0.0005 0.0000 36 0.0005 0.0000 37 0.0005 0.0000 38 0.0004 0.0000 39 0.0004 0.0000 40 0.0004 0.0000 41 0.0004 0.0000 42 0.0004 0. 0000 43 0.0004 0.0000 44 0.0004 0. 0000 45 0.0003 0.0000 46 0.0002 0.0000 47 0.0002 0.0000 48 0.0002 0.0000 49 0.0001 0.0000 50 0.0001 0.0000 51 0.0000 0.0000 POC #1 Facility FAILED duration standard for 1+ flows. Flow(CFS) Predev Dev Percentage Pass/Fail 0.0004 4506 44 0 Pass , 0.0004 3950 44 1 Pass 0.0005 3462 44 1 Pass 0.0005 3051 44 1 Pass 0.0005 2725 44 1 Pass 0.0006 2449 44 1 Pass 0.0006 2210 44 1 Pass 0.0006 2002 44 2 Pass 0.0007 1814 44 2 Pass 0.0007 1645 44 2 Pass 0.0007 1495 44 2 Pass 0.0008 1364 44 3 Pass 0.0008 1236 44 3 Pass 0.0008 1111 44 3 Pass 0.0009 1025 44 4 Pass 0.0009 926 44 4 Pass 0.0009 854 44 5 Pass 0.0010 794 44 5 Pass 0.0010 744 44 5 Pass • 0.0010 695 44 6 Pass 0.0011 643 44 6 Pass 0.0011 601 44 7 Pass 0.0011 554 44 7 Pass 0.0012 509 44 8 Pass 0.0012 475 44 9 Pass 0.0012 438 44 10 Pass 0.0013 401 44 10 Pass 0.0013 371 44 11 Pass 0.0013 346 44 12 Pass 0.0014 323 44 13 Pass 0.0014 307 44 14 Pass 0.0014 291 44 15 Pass 0.0015 273 44 16 Pass 0.0015 247 44 17 Pass 0.0015 220 44 20 Pass 0.0016 200 44 22 Pass 0.0016 186 44 23 Pass 0.0016 172 44 25 Pass 0.0017 158 44 27 Pass 0.0017 151 44 29 Pass 0.0017 141 44 31 Pass 0.0018 134 44 32 Pass 0.0018 128 44 34 Pass 0.0018 123 44 35 Pass 0.0019 116 44 37 Pass 0.0019 112 44 39 Pass 0.0019 105 44 41 Pass 0.0020 100 44 44 Pass 0.0020 94 44 46 Pass 0.0020 90 44 48 Pass 0.0021 89 44 49 Pass 0.0021 86 44 51 Pass 0.0021 86 44 51 Pass 0.0022 82 44 53 Pass 0.0022 78 44 56 Pass 0.0022 75 44 58 Pass 0.0023 74 44 59 Pass 0.0023 72 44 61 Pass 0.0023 69 44 63 Pass 0.0024 67 44 65 Pass 0.0024 64 44 68 Pass 0.0024 60 44 73 Pass 0.0025 60 44 73 Pass 0.0025 58 44 75 Pass 0.0025 56 44 78 Pass 0.0026 54 44 81 Pass 0.0026 53 44 83 Pass 0.0026 51 44 86 Pass 0.0027 50 44 88 Pass 0.0027 48 44 91 Pass 0.0027 47 44 93 Pass 0.0028 46 44 95 Pass 0.0028 43 44 102 Pass 0.0028 43 44 102 Pass 0.0029 41 44 107 Pass 0.0029 39 44 112 Fail 0.0029 39 44 112 Fail 0.0030 38 44 115 Fail 0.0030 38 44 115 Fail 0.0030 38 44 115 Fail 0.0031 37 44 118 Fail 0.0031 37 44 118 Fail 0.0031 37 44 118 Fail 0.0032 36 44 122 Fail 0 . 0032 36 44 122 Fail 0 . 0032 35 44 125 Fail 0 . 0033 35 44 125 Fail 0 . 0033 34 44 129 Fail 0 . 0033 33 44 133 Fail 0 . 0034 33 44 133 Fail 0 . 0034 32 44 137 Fail 0 . 0035 31 44 141 Fail 0 . 0035 31 44 141 Fail 0 . 0035 31 44 141 Fail 0 . 0036 30 44 146 Fail 0 . 0036 30 44 146 Fail 0 . 0036 29 44 151 Fail 0 . 0037 27 44 162 Fail 0 . 0037 27 44 162 Fail 0 . 0037 26 44 169 Fail The development has an increase in flow durations from 1/2 predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. Water Quality BMP Flow and Volume for POC 1. On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Perind and Impind Changes No changes have been made . This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages. Infiltration trench with pipe Using whole trench Length 46 If Width 2 feet Height 2 feet Pipe Dia 0.33 feet Pi Pipe Area 0.341946 sf 0.33 0.33 3.14 Trench Area 4 sf Void Ratio 0.33 Trench Volume in 1 If of trench: ((WidthxHeight)-Pipe Area)x void ratio)+ Pipe Area= 1.549 cf/If Total Trench Volume= 71.25878 cf total Adjusted void ratio= (Trench volume)/(Trench Area)= 0.39 DRIVEWAY-W WHvf VIEWS AND REPORT 0 WWHM3 driveway2 Ile Edit View Help .........__ .. .. ., ___ 1 lir— lir— ;lir—. lir— . _ .._ • .....N.J.,„ ...1-_._.. chernatic .a, -, Driveway Predeveloped , SCENARIOS , ' ...±1 : I 1 ___I Subbasin Name: IrDriway tillF,Predeveloped I Surface Interflow Groundwater 1 Flows To 1.-Mitigated Area in Basin 17 Show Only Selected Run Sceneno, . . . Available Pervious Available Impervious Fi FMFNTS TV C,Forest Flat .028 F.- ROOFTOPS FLAT j 0 1-- _______ IOW1 [ ' : IV DRIVEWAYS FLAT 10 ,PliF1 i.....40,51 faiiirWr„ i-..j." gy I 1781 - i I t P FE'2ird , , , . • , . , 1 : , I, ! —4-- --;-- 1 D is 1 i 1 . ' I I f i i I I I i . , I I i ! I 1 , , I ' 1 , Move Elements 1 , . ! L_I-1 1 I f •. PerviousTote. 0.028 Acres Impervious Total I) Acres ....r-, i . . . I , Basin Total 0.028 Acres 1 v. I di I _._ __ Save xy I Load xyl .. It.I —.--- -------- -- - 4 Fib 112 i ( I Deselect Zero I Select By: r----------- GO i • . . ... . . . . . . ., .... .. . . __ . . 111 . . _ .. . - ----- - • . . .. .. . . ___ .. _ ... _ _ _ _._ _ . ..._ ... . . . , r - I r .' • . 's '' 41).' 0/ . Aar r,', I 4, , r • N. k. ;,-,--x. . ( ;- ;ir p _ _ _ WWHM3 driveway2 Re Edit View Help l -7 .111L1iir— Mr.,._ lib— r .,,,,,,,„,,,_,,.,,,„.,,, cltetnatic Basin I Mitigated SCENARIOS i f , - Subbasin Name: basin 1 1— Designate as Bypass for POC: '; "*r Predeveloped I 1 Surface Interfloaa Groundwater 1 A _._.. _ - Flows To : Trapezoidal Pond 1 'Trapezoidal Pond 1 -� id Mitigated _ i I �~ i L i . ; Area in Basin V Show Only Selected Run Scenario ? !� Available Pervious Available Impervious _ .Fl FMFNTS -'-.1. ( - r� C.Forest Flat 110 r ROOFTOPS FLAT 0 - I DRNEWAYS FLAT j .028 1 z11 En- t r �M . _ p� f i 4., giE-5-111) ,4 , _______„________ . . . . . .,,_.,-_, - , , ,,,...ifigIA, . -I Dw i } i , . _ ....______ i . _ ______ I .�ya i . f _, . i . . . • .• . . -- -- - -±- . _ ' Move Elements f { , l� 1.1 F i I PetviousTota 0 Acres Impervious Total 0 028 Acres t:' ; I i I Basin Total 0.028 Acres tt I I e Save xy i Load xy I ® - --_ ---_____----_--------- it` _ mm �._ . .-______ - — --- — - — II << 40 1 1 12 —I I Deselect Zero I Select By: ` GO I _ .__.___mow__-._.�.- ,...-. — -- _ _�. - - - -= - in - - . _� . . 7- 1 11 p er' I Y N ''E ,. V"3 4 it ` I � p 31 > �t- v WWHM3 driveway2 — ile Edit View Help -QC* '''1/414_111--'."11!'r; la 1 ' thematic ' ri,Trapezoidal Pond 1 Mitigated SCENARIOS I Facility Name Trapezoidal Pond 1 .A 1-Predeveloped i -____) Outlet 1 Outlet 2 Outlet 3 Downstream Connections 0 0 i0 14 Mfitigated ___.._~~ ~- - ` __ _ - ; Facility Type 'Trapezoidal Pond ' F Precipitation Applied to Facility Auto Pond I Quick Pond i Run Scenario J I ! F[Evaporation Applied to Facil Fl FMFNTS -- -_� `____-_ _ Facility Bottom Elevation (ft) 0 . I 0 ' Facility Dimensions Ga' L=. im �e r r Outlet Structure `� e ' Bottom Lengih(ft) �40 gi ? '4 _ - -- RiserHeight(ft) 0.05 --•-I - i,�' Bottom Width(ft) 12.31 lam am En. ! i • 1 Effective Depth(ft) i0.05 _ Riser Diameter(in) •12 -=-1 6 ! Left Side Slope(HiV) (0 Riser Type (Flat -r-1 -- — -- f C__ ___� Notch Type Drii_17 j T_ ! • Bottom Side Slope(H/ ) L0s= -+ 1 ; Right Side Slope(FIN) r0 I ; Top Side Slope(FIN) 0 -- 1". ir■� -___E . Facility Dimension Diagram �� - Orifice Diameter Height QMax . fl. Infiltration ,YES -:-I Number (In) (Ft) (cfs) ze . , Measured Infiltration Rate(in/hr) 1 5 i ��~ Reduction Factor(infilt*factor) ij -,--,-I 2 [--- I-".•e J 0 : Use Wetted Surface Area(sidewalls) •NO -=-j 3 0�`- y -1 IF—-:-.1 0 L- •_ Total Volume Infiltrated(acre-ft) 2.02 "�� ��� ---1 Pond Volume at Riser Head(acre-ft) .001 • Total Volume Through Riser(acre-ft) 0 Move Elements- I • Pond Increment 0.10 =1 Total Volume Through Facility(acre-ft) 2.02 - I inI' 1 I I Percent Infiltrated 100 Show Pond Table 10pan Table - -1 I Use Tide Gate? NO - • Save xy J Load xyj 4 I r --- - - - - - . Y 50 I u l W'INHM3 driveway2 re E&t View i ep ate.: ins.- MI,: . • , "r-----14) '1 ' '''-'!--,e.- -ju,,,e,'" i ,ri I � • 1 El j l !- 501 P061 Predeveloped fi Flow Frequency " RI 10E1 axxxxxxxxxxxxxxxxxxx=w>mxxxxxxxxxxxxxxxxxxxx . 701InflowtoPOClMitigat1 Flow(CFS) 0501 0701 0801 801 POC1 Mitigated flow 1 2 Year = 0.0003 0.0064 0.0000 li5 Year = 0.0006 0.0058 0.0000 1110 Year = 0.0008 0.0106 0.0000 25 Year -- 0.0011 0 .0131 0.0000 c 10E® 50 Year 0.0014 0.0150 0.0000 0 100 Year = 0.0016 0.0171 0.0000 I ______ •i I jYearly Peaks 0 1949 0.0010 0.0080 0 .0000 I= j 10E-1 Ili 1950 0.0006 0,0060 0.0000 1951 0.0004 0 .0072 0.0000 1952 0.0003 0.0066 0.0000 1953 0.0001 0.0081 0.0000 10E-2 _ e 1954 0.0002 0.0055 0.0000 L A C 1 10 20 30 4050-..6�9 -:7 3' :'80":nu 90 99 II 1955 O.OQ02 0.0039 0.0000 g{,ao �- `� 1956 0.0003 0 .0039 0.0000 4�$Q)11J11.d}i� tiVe PrTobal-Ally i 195'7 0.0004 0.0084 0.0000 1958 0.0002 0.0058 0.0000 Durations Flow Frequency Water Quality -I Hydrograph i Wetland Fluctuation ; 1959 0.0006 0.0041 0.0000 1960 0.0003 0.0084 0.0000 Analyze datasets 1961 0.0002 0. 0050 0.0000 1 PUYALLUP DAILY EVAP W/JENSEN-RAISE • Q 1962 0.0000 0.0075 0 .0000' 2 BURLINGTON PRECIP - ii 1963 0 .0002 0 .0039 0.0000 i (' 1964 0.0003 0.0076 0.0000 1-' Ii 1965 0.0005 0.0174 0.0000 1000 Gravel Trench Bed 1 ALL OUTLETS Mitigated 1966 0.0001 0.0049 0.0000 1001 Gravel Trench Bed OUTLET1 Mitigated 1967 0.0003 0.0122 0.0000 1002 Gravel Trench Bed 1 OUTLET 2 Mitigated 1968 0.0006 0 .0098 0.0000 1969 0.0001 0 .0039 0.0000 Acres All Datasets [Flow f Stage J Precip j Evap POC 1 j 1970 0.0001 0.0125 0.0000 1971 0.0007 0.0067 0.0000 Flood Frequency Method 1972 0.0003 0.0047 0 .0000 co Log Pearson Type III 17B 1973 0.0002 0.0056 0.0000 _ C Weibull 11 �.74___.. _____._ n nnn�; n nn.RS n noon Cunnane ` . I- r r., r r ` Western Washington Hydrology Model PROJECT REPORT Project Marne: driveway2 Site Address : City Report Date o 9/28/2017 Gage : Burlington Data St rt 1948/10/01 Data Ene? . 1999/09/30 Preca.p Scale: 0< 8 3 Version: PREDEVELOPED LAND USE Name . Driveway pass: No Ground3'ater: No Pervious Land Use Aczes C, Forest, Flat" .020 Impervious Land Use Acres Element Flows To: Surface In terflow Groundwater Kama . Basin 1 B pL._s : No Groan Kater: No Peious Land Use Acres Impervious Land Use Acres DRIVEWAYS FLAT -0 .02 8 Element Flows To: Surface lnterflow Groundwater MITIGATED LAND USE 900'0 T00°0 E861 500'0 000'0 Z86T L00'0 000'0 T86T 500'0 000'0 086! 0T0°0 000'0 6L61 500'0 000 '0 8L61 600'0 000'0 LL6T Z10'0 Z00°0 9L6T 900'0 T00'0 SL61 900'0 000'0 VL6T 500'0 000'0 £L6T L00'0 T00'0 ZL6T Z10°0 000°0 TL6T 000'0 000'0 0L6T 0I0'0 T00°0 696T ZT0'0 000°0 8961 500'0 000'0 L96T LT0'0 000'0 9961 800'0 000'0 596T '00'0 000°0 9961 800°0 000'0 £96T 500°0 000'0 Z96T 800'0 000°0 1961 P00°0 100'0 096T 900°0 000'0 6561 800°0 000'0 856T 000°0 000'0 L96T P00°0 000'0 9561 900'0 000'0 556T 800'0 000'0 096T L00'0 000'0 £56T L00'0 000'0 Z56T 900°0 100'0 T56T 800°0 T00'0 096T T#� ood .pellster4T14 Tau PedoioAepe-ad _xog azised AT. sex 5ZTLT0'0 xeca 001: 9E0510'0 assA 0g ZL0£T0'0 ase,A gZ LZ9010°0 ayeA 0T Z68800°0 xA g E6E900'0 see 26.E-8 ci5T2 Po!Xad uanq u 3 20a `pels5`eqx'g° aog ayaoYwed rx,--regeg Aouvhbeas mow 8ST00'0 be OOT £5ET00°0 aseA 05 ZZT100°0 rests 5Z 5T8000'0 xvedl 0T 085000°0 •ameA 5 6L2000'0 iseA asvinsof aTgXT ? 1984 0.000 0. 005 1985 0.001 0.007 1986 0.000 0.007 1987 0.000 0.005 1988 0.000 0.004 1989 0.001 0.011 1990 0.000 0.006 1991 0.000 0,007 1992 0.001 0.010 1993 0.000 0.006 1994 0.000 0.004 1995 0.000 0.005 1996 0.000 0.005 1997 0.000 0.008 1998 0.001 0.014 1999 0.000 0.007 2000 0,000 0.004 Ranked Yearly Peaks for ?redeveloped and Mitigated. POC #1 Rank ?redeveloped Mitigated 1 0.0024 0.0174 2 0.0011 0.0144 3 0.0010 0.0125 4 0.0009 0.0122 5 0.0007 0.0116 6 0.0007 0.0108 7 0,0007 0.0103 8 0.0006 0.0102 9 0.0006 0.0098 10 0.0006 0.0068 11 0.0006 0.0084 12 0.0006 0.0084 13 0.0005 0.0081 14 0.0005 0,0080 15 0.0004 0.0077 16 0.0004 0.0076 17 0.0004 0.0075 18 0.0003 0.0072 19 0.0003 0.0072 20 0.0003 0.0012 21 0.0003 0.0070 22 0.0003 0.0069 23 0.0003 0.0067 24 0.0003 0.0067 25 0.0003 0.0066 26 0.0003 0.0064 27 0.0003 0,0062 28 0.0003 0.0061 29 0.0003 0.0060 30 0.0002 0.0058 31 0.0002 0.0056 32 0.0002 0.0055 33 0,0002 0.0055 34 0.0002 0.0055 35 0.0002 0.0054 36 0.0002 0.0053 37 0.0002 0.0052 38 0.0002 0.0052 39 0.0002 0.0050 40 0. 0002 0.0049 41 0.0001 0.0047 42 0.0001 0.0047 43 0.0001 0.0046 44 0.0001 0.0044 45 0.0001 0.0041 46 0.0001 0.0040 47 0.0001 0.0039 48 0.0001 0.0039 49 0.0000 0.0039 50 0.0000 0.0039 51 0.0000 0.0038 Poe #1 Facility P'r\_iL .L duration standard for 1+ flows. Flow(CFS) Predev Dew Percentage Pass/Fail 0.0001 4538 36765 810 Fail 0.0002 3991 35393 886 Fail 0.0002 3462 34154 986 Fail 0.0002 3061 33225 1085 Fail 0.0002 2733 32281 1181 Fail 0.0002 2468 31334 1269 Fail 0.0002 2212 30350 1372 Fail 0.0002 2005 29487 1470 Fpil 0.0002 1821 28647 1573 Fail 0.0002 1654 27838 1683 Fail 0.0003 1490 27078 1817 Fail 0.0003 1365 26465 1938 Fail 0.0003 1243 25884 2082 Fail 0.0003 1118 25379 2270 Fail 0.0003 1025 24780 2417 Fail 0.0003 930 24234 2605 Fail 0.0003 857 23702 2765 Fail 0.0003 798 23211 2908 Fail 0.0004 744 22710 3052 Fail 0.0004 696 22223 3192 Fail 0.0004 646 21780 3371 Fail 0.0004 602 21311 3540 Fail 0.0004 554 20788 3752 Fail 0.0004 510 20332 3986 Vail 0.0004 475 19925 4194 Fail. 0.0004 439 19473 4435 Fail 0.0005 401 18959 4727 Fail 0.0005 371 18584 5009 Fail 0.0005 346 18280 5283 Fail 0.0005 325 17918 5513 Fail 0.0005 307 17569 5722 Pail 0.0005 291 17265 5932 Fail 0.0005 273 16903 6191 Pail 0.0005 247 16568 6707 Fail 0.0006 220 16255 7388 Fail 0.0006 200 15955 7977 Fr,i1 0.0006 187 15678 8383 0.0006 172 15392 8948 Lail 0.0006 158 15106 9560 F:4i 1. 0.0006 152 14829 9755 Fai ' 0.0006 142 14578 10266 Fail 0.0006 134 14270 10649 Fail 0.0007 128 14037 10966 Fail 0.0007 123 13791 11212 Fail 0.0007 116 13546 11677 Fail 0.0007 112 13291 11866 Fail • 0.0007 105 13036 12415 Fail 0.0007 100 12795 12795 trail 0.0007 94 12540 13340 Fail 0.0007 90 12258 13620 Fail 0.0008 89 12084 13577 Fail 0.0008 86 11883 13817 Fail 0.0008 86 11641 13536 Fail 0.0008 82 11386 13885 tail 0.0008 78 11149 14293 Tail 0.0008 75 10957 14609 mail 0.0008 74 10756 14535 Fail 0.0008 72 10577 14690 Fail 0.0009 69 10407 15082 rail 0.0009 67 10246 15292 Fail 0.0009 64 10085 15757 Fail 0.0009 60 9893 16488 Fail 0.0009 60 9710 16183 Fail 0.0009 58 9500 16379 F a i] 0.0009 56 9330 16660 Fail 0.0009 54 9133 16912 Fail 0,0009 53 8941 16869 Fail 0.0010 51 8816 17286 Fail_ 0.0010 50 8686 17372 Fail 0.0010 48 8588 17891 Fail 0.0010 47 8472 18025 Fail 0.0010 46 8351 18154 Fai1. 0.0010 43 8221 19118 Vail 0.0010 43 8114 18869 Fail 0.0010 41 8002 19517 Tail 0.0011 39 7908 20276 Fail 0.0011 39 7792 19979 Fail 0.0011 38 7667 20176 !'.ai3 0.0011 38 7586 19963 Fail 0.0011 38 7488 19705 bail 0.0011 37 7403 20008 Fail 0.0011 37 7327 19802 Fail 0.0011 37 7233 19548 Fail 0.0012 36 7157 19880 Fail 0.0012 36 7023 19508 Fail 0.0012 35 6938 19822 Fail 0.0012 35 6840 19542 bail 0.0012 34 6750 19852 Fail 0.0012 33 6665 20196 Fa'. ] 0.0012 33 6576 19927 Fail 0.0012 32 6509 20340 pail 0.0013 31 6420 20709 Fail 0 . 0013 31 6317 20377 ' aii 0 . 0013 31 6227 20087 ail 0 . 0013 30 6156 20520 Fail 0 . 0013 30 6084 20280 ;:ail 0 . 0013 29 6013 20734 Fail 0 . 0013 27 5937 21988 Fail 0 . 0013 27 5874 21755 Fail 0. 0014 26 5816 22369 Fail The drAmiopmexit has an increase in flow dux itions from 1/2 ed, eler d 2 ye .r flow to the 2 year floe or more than a 10:is increase from the 2 year to the 50 year now. 'aterc (Nullity Ei- miow and volume for POC 1. On-line facility volume: 0 acre-feet On-line facility target flow: 0 oft. Adjust-fad for 15 min: 0 cgs. Off-lina if&milit3r tanot flow: 0 ofe. iraci5usted Ear 15 min: 0 cfe. P3xin l end Lid Change e No changes have been made This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages . S I E )EWALK-WWH[M VIEWS AND REPORT 3 WWHM3 Sidewalk 'ile Edit View Help _ , rill _ ;I�_ ilia _ ' !it,--: a ' ..7'.:4- 1,...---...,"----;>474r r I. 1 ill c#}ernatjc Driveway Predeveloped SCENARIOS • — Subbasin Name: Driveway h P Predeveloped Surface Interflow Groundwater ' 1—Mitigated • Flows To : I • I� Show Only in Basin iv, Selected Run Scenario_ I I Available Pervious Available Impervious F C,Forest Flat l_i]`.',I p ROOFTOPS FLAT I :0 FI FMFNTS -- — _� � !O it DRIVEWAYS FLAT I 0 II-4, M- az3 CA C / A. f 1 i 1,,„ :•.), al. mum .iti 1.1 14010 g[EA Ell El i ; __ r i • ____ I i — i . . ; , ! . I l i ; ! ----- ; , , . .j i I f i i • , 1 !I1 .! I , j ' , • . ; 1 1 , 1 . . , . ; . 1 ! 1 . -Move Elements , i ! i -1_ rl`r r i + I PerviousTota 0.011 1 Acres Impervious Total 0 Acres f i Basin Total 0.011 Acres r I i I 1 v Save xy I Load xy i ® r -- .. - --- - _ _ .. --- K 40 I Y 12 1 Deselect Zero I Select By: `— � -------- GO I r . rrr r.,__ _ L.J., , . , II . , , . :! 1 0 - . ,,I, p am 1 J WWHM3 Sidewalk :iie Edit View Help • Illit 1 "1°4.'5,449 . i Ei ' rill—, , ,"1"kiltaw ,_I 1-'-,I 1 thematic I i3; SCENARIOS # Basin 1 Mitigated -I Subbasin Name: Basin 1 I- Designate as Bypass for POC: 31—Predeveloped I I _._-_J Surface Interfloar Groundwater � - • Flows To : _.1j ram= jd Mitigated I I I f Area in Basin F Show OnlySelected . Run Scenario i , I I Available Pervious Available Impervious Fl FMFNTS i s NS..Forest Flat 0 L I i ROADS/FLAT 0 --_ _ _ ��- 1 I Jai. r-- Are,Forest Mod 0 f I— ROADS/MOD 0 µri`_ f F �' NB,Forest Steep 0 r ROADS/STEEP ( 0 El �' t ! AJe,Pasture,FlatL- (d ROOFTOPS FLATL-- —J r A/B,Pasture,Mod i 0 )✓ DRIVEWAYS FLAT l� join 1 ° urigt -.s LJ i 1p NB,Pasture,Steep 0 r DRIVEWAYS/MOD 0 ,__� 1 i r AB.Lawn,Flat 0 —J I— DRIVEWAYS/STEEP 1 0 ,� I— AIB,Lawn,Mod ) 0 r SIDEWALKS/FLAT 11 7 ''; f ' , ,r A/B,Lawn,Steep 0 r SIDEWALKS/MOD 0 • I�, r- SIDEWALKS/STEEP 0 -- - _x — ___+. --_ G Forest Flat L V ' i ;- C,Forest Mod 10 p PARKING/FLAT 0 �� r C,Forest Steep 0 i r PARKING/MOD 0 _ —_j-_ ti __ ! C Pasture.Flat 0 Fr- PARKING/STEEP 0 r , I C Pasture,Mod 0 ) r POND a .r C,Pasture,Steep 0 i r C Lawn,Flat 0 — L � ^ (- C.Lawn,Mod 0 Move Elements ' — ®'I[ C Lawn,Steep 0 I' I ' • - - PerviousTota I0 Acres Impervious Total 0.011 I Acres :'1 �•----�-; I�' I Basin Total O.011 Acres J Save Load xy 4 1 1 ..... X 40 I Deselect Zero I Select By: ' GO ` � L 1 P�1 J WWHM3 Sidewalk lie Edit View Help II his- 1417 hr._ huh- a��e . ri Mill „„,., :ittim,_ _i Analysis I o II- i_- mi 501 POC Predeveloped1 Fl Frequency _ - r Mti 10E1 Ng l£low(CFS) Predeveloped Mitigated B01 POC 1 Mitigated flow P B 12 Year = 0.0001 0.0025 15 Year = 0.0002 0.0035 !10 Year = 0.0003 0.0042 3 $25 Year = 0.0004 0.0051 t0E0-5 50 Year = 0.0005 0.0059 100 Year = 0.0006 0.0067 , 'Yearly Peaks 0 1949 0.0004 0.0031 I__ j 10E-1. 1950 0.0002 0.0023 1951 0.0002 0.0028 I 1952 0.0001 0.0026 1953 0.0001 0.0032 { 10E-2_, 1954 0.0001 0.0022 1 10 20 80 40 50 60 70 80 90 99 11956 0.0001 0.0015 ' 9 1955 0.0001 0.0015 _ ___.,_. Currrulative Probability AL,°nn°°°°°°pG° 1957 0.0002 0.0033 r 1958 0.0001 0.0023 Durations Flow Frequency ;jWaterDualiity 1 Hydrograph 1 Wetland Fluctuation 1959 0.0002 0.0016 - 1960 0.0001 0.0033 Analyze datasets 1961 0.0001 0.0019 -� �i t Cs Predv heclr ,;i 11962 0.0000 0.0030 ;di��, 1 t•:t�liaat,„l.i.,, 1963 0.0001 0.0015 1964 0.0001 0.0030 1965 0.0002 0.0068 1966 0.0000 0.0019 1967 0.0001 0.0048 l 1968 0.0002 0.0039 1969 0.0001 0.0015 l Acres All Datasets�Flow l Stage 1 Precip 1 Evap ppC 1 k 1970 0.0000 0.0049 1971 0.0003 0.0026 Flood Frequency Method 1972 0.0001 0.0018 r: Log Pearson Type III17B 1973 0.0001 0.0022 C Weibull 1974 _ _ n nnn9 n nrn�9 C Cunnane F "' r na„ - I Western Washington Hydrology Model PROJECT REPORT Project Name: Sidewalk Site Address : City Report Date : 10/19/2017 Gage : Burlington Data Start : 1948/10/01 Data End : 1999/09/30 Precip Scale: 0 . 83 WWEM3 Version: PREDEVELOPED LAND USE Name : Driveway Bypass: No GroundWate r: No Pervious Land Use Acres C , Forest, Flat . 011 Impervious Land Use Acres Element Flows To: Surface Interflow Groundwater Name : Basin 1 Bypass : No GroundWater: No Pervious Land Use Acres Iffipervious Land Use Acres SIDEWALKS FLAT 0 . 011 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.00011 5 year 0.000229 10 year 0.00032 25 year 0.000441 50 year 0.000531 100 year 0.000621 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.002512 5 year 0.003474 10 year 0.004175 25 year 0.005135 50 year 0.005907 100 year 0.006728 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1950 0.000 0.003 1951 0.000 0.002 1952 0.000 0.003 1953 0.000 0.003 1954 0.000 0.003 1955 0.000 0.002 1956 0.000 0.002 1957 0.000 0.002 1 1958 0.000 0.003 1959 0.000 0.002 1960 0.000 0.002 1961 0.000 0.003 1962 0.000 0.002 1963 0.000 0.003 1964 0.000 0.002 1965 0.000 0.003 1966 0.000 0.007 1967 0.000 0.002 1968 0.000 0.005 1969 0.000 0.004 1970 0.000 0.002 1971 0.000 0.005 1972 0.000 0.003 1973 0.000 0.002 1974 0.000 0.002 1975 0.000 0.002 1976 0.001 0.005 1977 0.000 0.003 1978 0.000 0.002 1979 0.000 0.004 1980 0.000 0.002 1981 0.000 0.003 1982 0.000 0.002 1983 0.000 0.002 1984 0.000 0.002 1985 0.000 0.003 1986 0.000 0.003 1987 0.000 0.002 1988 0.000 0.002 1989 0.000 0.004 1990 0.000 0.002 1991 0.000 0.003 1992 0.000 0.004 1993 0.000 0.002 1994 0.000 0.002 1995 0.000 0.002 1996 0.000 0.002 1997 0.000 0.003 1998 0.000 0.006 1999 0.000 0.003 2000 0.000 0.001 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0010 0.0068 2 0.0004 0.0056 3 0.0004 0.0049 4 0.0003 0.0048 5 0.0003 0.0045 6 0.0003 0.0043 7 0.0003 0.0040 8 0.0002 0.0040 9 0.0002 0.0039 10 0.0002 0.0035 11 0.0002 0.0033 12 0.0002 0.0033 13 0.0002 0.0032 14 0.0002 0.0031 15 0.0002 0.0030 16 0.0002 0.0030 17 0.0002 0.0030 18 0.0001 0.0028 19 0.0001 0.0028 20 0.0001 0.0028 21 0.0001 0.0027 22 0.0001 0.0027 23 0.0001 0.0026 24 0.0001 0.0026 25 0.0001 0.0026 26 0.0001 0.0025 27 0.0001 0.0024 28 0.0001 0.0024 29 0.0001 0.0023 30 0.0001 0.0023 31 0.0001 0.0022 32 0.0001 0.0022 33 0.0001 0.0022 34 0.0001 0.0022 35 0.0001 0.0021 36 0.0001 0.0021 37 0.0001 0.0020 38 0.0001 0.0020 39 0.0001 0.0019 40 0.0001 0.0019 41 0.0001 0.0018 42 0.0001 0.0018 43 0.0001 0.0018 44 0.0001 0.0017 45 0.0000 0.0016 46 0.0000 0.0016 47 0.0000 0.0015 48 0.0000 0.0015 49 0.0000 0.0015 50 0.0000 0.0015 51 0.0000 0.0015 POC #1 Facility FAILED duration standard for 1+ flows. Flow(CFS) Predev Dev Percentage Pass/Fail 0.0001 4488 36649 816 Fail 0.0001 4018 35496 883 Fail 0.0001 3498 34253 979 Fail 0.0001 3071 33247 1082 Fail 0.0001 2725 32259 1183 Fail 0.0001 2442 31262 1280 Fail 0.0001 2242 30480 1359 Fail 0.0001 2020 29568 1463 Fail 0.0001 1827 28665 1568 Fail 0.0001 1648 27797 1686 Fail 0.0001 1487 27069 1820 Fail 0.0001 1383 26532 1918 Fail 0.0001 1252 25929 2071 Fail 0.0001 1120 25392 2267 Fail 0.0001 1030 24798 2407 Fail 0.0001 926 24221 2615 Fail 0.0001 864 23774 2751 Fail 0.0001 798 23242 2912 Fail 0.0001 748 22750 3041 Fail 0.0001 697 22236 3190 Fail 0.0002 643 21771 3385 Fail 0.0002 610 21369 3503 Fail 0.0002 560 20886 3729 Fail 0.0002 513 20368 3970 Fail 0.0002 476 19938 4188 Fail 0.0002 438 19460 4442 Fail 0.0002 401 18950 4725 Fail 0.0002 375 18628 4967 Fail 0.0002 346 18311 5292 Fail 0. 0002 326 17922 5497 Fail 0. 0002 308 17578 5707 Fail 0.0002 291 17261 5931 Fail 0.0002 274 16943 6183 Fail 0.0002 251 16612 6618 Fail 0.0002 227 16286 7174 Fail 0.0002 200 15964 7982 Fail 0.0002 186 15665 8422 Fail 0.0002 174 15459 8884 Fail 0.0002 159 15137 9520 Fail 0.0002 152 14851 9770 Fail 0.0002 142 14587 10272 Fail 0.0003 134 14279 10655 Fail 0.0003 130 14086 10835 Fail 0.0003 123 13827 11241 Fail 0.0003 117 13568 11596 Fail 0.0003 113 13313 11781 Fail 0.0003 105 13045 12423 Fail 0.0003 101 12839 12711 Fail 0.0003 95 12567 13228 Fail 0.0003 91 12303 13519 Fail 0.0003 89 12097 13592 Fail 0.0003 87 11891 13667 Fail 0.0003 86 11637 13531 Fail 0.0003 82 11440 13951 Fail i 0.0003 80 11185 13981 Fail 0.0003 75 10979 14638 Fail 0.0003 74 10760 14540 Fail 0. 0003 72 10582 14697 Fail 0.0003 71 10443 14708 Fail 0.0003 67 10264 15319 Fail 0.0003 64 10099 15779 Fail I 0.0003 60 9911 16518 Fail 0.0004 60 9714 16189 Fail 0.0004 58 9536 16441 Fail 0.0004 57 9343 16391 Fail 0.0004 55 9160 16654 Fail 0.0004 53 8959 16903 Fail 0.0004 51 8820 17294 Fail 0.0004 50 8717 17434 Fail 0.0004 49 8606 17563 Fail 0.0004 47 8485 18053 Fail 0.0004 46 8369 18193 Fail 0.0004 43 8235 19151 Fail 0. 0004 43 8145 18941 Fail 0.0004 41 8029 19582 Fail 0.0004 39 7926 20323 Fail 0.0004 39 7810 20025 Fail 0.0004 38 7676 20200 Fail 0.0004 38 7586 19963 Fail 0.0004 38 7501 19739 Fail 0.0004 37 7421 20056 Fail 0.0004 37 7336 19827 Fail 0.0004 37 7238 19562 Fail 0.0005 36 7162 19894 Fail 0.0005 36 7050 19583 Fail 0.0005 35 6956 19874 Fail 0.0005 35 6853 19580 Fail 0.0005 34 6759 19879 Fail 0.0005 33 6670 20212 Fail 0. 0005 33 6607 20021 Fail 0.0005 32 6522 20381 Fail 0.0005 32 6429 20090 Fail 1 0 . 0005 31 6339 20448 Fail 0 . 0005 31 6236 20116 Fail 0 . 0005 31 6178 19929 Fail 0 . 0005 30 6098 20326 Fail 0 . 0005 30 6022 20073 Fail 0 . 0005 27 5946 22022 Fail 0 . 0005 27 5883 21788 Fail 0 . 0005 26 5816 22369 Fail The development has an increase in flow durations from 1/2 predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. Water Quality BMP Flow and Volume for POC 1. On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Perind and Impind Changes No changes have been made . This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages. BeamChek v2013 licensed to:Jack Reinstra/Landed Gentry Homes& Communities Reg#4117-67766 Padilla ADU Main Floor ADU Beams Prepared by:JR Date: 9/15/17 Selection 4x 8 HF#2 Lu =0.0 Ft Conditions NDS 2012 Min Bearing Area R1=3.9 in2 R2=3.9 in2 (1.5) DL Defl= 0.02 in Data Beam Span 5.25 ft Reaction 1 LL 1247# Reaction 2 LL 1247# Beam Wt per ft 6.17# Reaction 1 TL 1575# Reaction 2 TL 1575# Bm Wt Included 32# Maximum V 1575# Max Moment 2068'# Max V(Reduced) 1213# TL Max Defl L/240 TL Actual Defl L/805 LL Max Defl L/480 LL Actual Defl L/>1000 Attributes Section(in3) Shear(in2) TL Deft(in) LL Deft Actual 30.66 25.38 0.08 0.06 Critical 22.46 12.13 0.26 0.13 Status OK OK OK OK Ratio 73% 48% 30% 43% • Fb(psi) Fv(psi) E(psi x mil) Fc I (psi) Values Reference Values 850 150 1.3 405 Adjusted Values 1105 150 1.3 405 Adjustments CF Size Factor 1.300 Cd Duration 1.00 1.00 Cr Repetitive 1.00 Ch Shear Stress N/A Cm Wet Use 1.00 1.00 1.00 1.00 CI Stability 1.0000 Rb=0.00 Le=0.00 Ft Loads Uniform LL:475 Uniform TL: 594 =A D F, (i-c-,4 r7 F,1 77 r% (--,-. 11t OCT 0 4 2011 CITY OF ANIAC CR FhS 4 Uniform Load A L I rL 0 R1 = 1575 R2= 1575 SPAN =5.25 FT Uniform and partial uniform loads are lbs per lineal ft. l Fyrrce, Groc From: Fyrrce, Groc Sent: Monday, October 09, 2017 6:19 PM To: 'Jack Reinstra' Cc: Lange, Steve Subject: 07-10-17 Review Memo 2202 15th Street.pdf Attachments: 07-10-17 Review Memo 2202 15th Street.pdf Hi Jack, Steve's corrections in his Plan review notes still need to be addressed. I attached a copy of it just in case. Best regards, Groc Fyrrce Building Inspector/Permit Technician City of Anacortes (360)293-1901 ,z- :://wAy lcfibi 'if/ cavn/iirani/Mf//roly%CChierc%i/.and cai ieratairz, My incoming and outgoing email messages are subject to public disclosure requirements per RCW 42.56. 1 City of Anacortes Hydrant Maintenance Headquarters Hydrant Information Hydrant 393 Location 15th Street Cross Street D Avenue Map No. _ 11 Zone I i_____ 00 PSI 145 Barrel Size L 5.25 Thread Size 01 Model Pac States Barrel Depth 4 Adapter? El City Hydrant? Mfg Year 1977 Open Turns 12 Existing? (Uncheck if removed Iiel Installed 1977 Main Size 16 Pipe Segment WD106001347 Port 1 4.12 Shut Off Size E 1 6 Value $1,554.00 ... Port 2 2.50 Shut Off Location 121' East of Hydrant Donated'? Port 3 2.50 Project No. r X Coordinate #Name? Notes Y Coordinate #Name? USGS Elevation 76 within 0 to 2' i kr ), i 6 ,A.- 6) ,-,, () 7,-- ,) u Page 1 of 1 10/27/2017 Fyrrce, Groc From: Fyrrce, Groc Sent: Thursday, October 12, 2017 9:55 AM To: 'Jack Reinstra' Cc: Ingalls, Paul; Kennedy,Jack; Nelson, Keit; Lange, Steve Subject: 2202 15th Stormwater 2 Attachments: 2202 15th Stormwater 2,docx Hi Jack, Please see attached Second Plan Review Note from Kait for corrections that need to be addressed so that she can finish her plan review. Please see the following corrections from Jack's Plan Review that needs to be addressed so that he can finish his plan review: 2202 15th St. 4,512 1. 1750 gpm required fire flow. 2. Must provide proof of adequate flow or install residential sprinkler system per NFPA 13D. Jack Kennedy Assistant Chief/Fire Marshal Anacortes Fire Department 360-293-1932 Office 360-661-3437 Cell Steve's corrections will, also, need to be addressed along with an issuance of the ADU permit before issuing the permit. Best regards, Groc Fyrrce Building Inspector/Permit Technician City of Anacortes (360)293-1901/ G �i//ic IcAr lfiele 1c/ eainirucith'/e //rirne/r,e'/i w/ion/•rcizr/Nye"ci//oil c � My incoming and outgoing email messages are subject to public disclosure requirements per RCW 42.56. 1 TY < L DEPARTMENT OF PLANNING, COMMUNITY & ECONOMIC DEVELOPMENT DATE: October 11, 2017 T*: Groc Fyrrce Building Inspector & Perirac ii echrfician FR•Th Kait Nelson Associate Planner PCED SUBJECT: 2202 15th Street, BLD-2017-0349; Stormwater Plan Review Several revisions are necessary to complete the stormwater review: • The"Impervious Coverage"breakdown should be hard surfaces in general. The building is showing the footprint instead of the roof coverage, which would be incorrect.In addition to that,the Public Works Department is requiring street improvements. While off-site,those improvements are considered a common plan of development with this lot. The square footage of those improvements must be included with the hard surface breakdown and will count towards the threshold to determine minimum requirements. If the total hard surface area exceeds 5,000 sq. ft.,then minimum requirements 1-9 will be required. • Stormwater facilities are not labeled on site plan with BMP title. The infiltration trench would be BMP T7.20 Infiltration Trench and a driveway dispersion would be BMP T5.12 Sheet Flow Dispersion, if those are the intended methods. Please also show the area with dimensions of the location reserved for sheet flow dispersion on the site plan. • The DOE stormwater manuals states as"guidance"that infiltration trenches be at least 20 feet from any uphill foundations, and at least 100 feet from any downhill foundations. Can the engineer confirm that the location of the infiltration trench will not have a significant negative impact on surrounding foundations?Please provide a signed memo. If you have any questions, feel free to call me at 360.299.1969. Kait Nelson Associate Planner Nelson, Kait From: Fyrrce, Groc Sent: Tuesday,August 15, 2017 11:43 AM To: Nelson, Kait Cc: Measamer, Don Subject: Stormwater Plan review resubmittals Hi Kait, I have a couple contractors who wanted to pick up there permits last week, and would like to pick them up this week. Will you please review the re-submittals for the following property by the end of business day tomorrow, so that I can get them ready to issue before I leave on vacation? The properties are as follows: • oa • u e irc • --440-7 CutteaDrive Also if you have time, can you review 2202 15th Street and send me your corrections so that I can send them out to the contractor before I leave on vacation. Best regards, Groc Fyrrce Building Inspector/Permit Technician City of Anacortes (360)293-1901 LT/!07ll7/o/t'on/ck r (ow/ fil/[ej///folly (r/fI[•e/C('J/ rl1a�C�c/ir�C�/mI/ My incoming and outgoing email messages are subject to public disclosure requirements per RCW 42.56. Imo 3541-- 1 1 Locate drain 25'from =2 a,. ROW if driveway !I g, slopes toward street. M t 700 sq. ft. max. between berms f l i ` N..1 Driveway M 2-4" Slope N ddr\... He— 6' min -0-1 . i ) ):14--',,..5. 5.-:: ) Berm Detail k'"k4'" Diagonal - - ---- ::::i Ji 25'vegetated berm with - 25' � flowpath dispersion i / trenchli / Plan Driveway Dispersion Trench Driveway Slope Varies and Slopes Toward Street 1 / �' ,� / r / Max. 2% Driveway I / cross slope Slope / 0 _ EE _25 ►y , Plan ,i ((%, z_.,_ rr, Ada _—, Z .i Sheet Flow Dispersion from a Driveway - Flat to Moderately Sloping Driveways I NOT TO SCALE llE. 1 ft` Figure V-5.3.2 "Illiiiiiiiiii Sheet Flow Dispersion for Driveways DEPARTMENT O F Revised January 2016 ECOLOGY Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. AI Y 3,.. OCT 13gill ' . CITY OF .AN/A Of�IE October 10, 2017 Anacortes Planning&Community Development Dept. Attn: Groc Fyrrce RE: Plan change for the proposed home/ADU at 2202 15th Street, Since our first submittal of our Padilla ADU plans for 2202 15th Street,it was decided to reverse the plans. Structural, nothing changes, however, I am submitting a reversed set so upon approval, the job site will have the correct and approved orientation. You already have the updated site and landscape plans. I have included two sets of plans and two copies of the floor plans. Jack Reinstra Landed Gentry I RESIDENCE II lf:SIDENCE I fESip{;IJCE —� it T q WA / EX TYPE 1 - - - J I I --- - --- -- --- - -- I 6o SD UNDERO f21 V ; I Rib T.69.31 1 SOLt — !N 63 81 I ala —_ WWI TH 6" CLEARANCE ; I SDMH { ) JD ! 6" PVC TO CBI ' 6" NV= 65,00 SDCB(E) ABBREVIATED LEGAL DESCRIPTION: x - _r I. OCT 5 all LANDED GENTRY THE EAST HALF OF LOT 17, ALONG WITH ALL OF LOTS 18, CONC BURLINGTON SDCB Iid DOME' S AND COMMUNITIES 6" INV= 62.57 BURLINGTON CONCR.1TE - i r- 13, AND 20, OF BLOCK 206, AS PER SURVEY RECORDED 4" ndv= 6257 CATCH BASIN WWlTH I ( — UNDER AUDITOR 'S FILE NUMBER 200303170356, RECORDS SOLID LID F11lsH WW,TH 6.D L -- I GENERAL NOTES OF SKAGIT COUNTY, STATE OF WASHINGTON. rr,Jrr sfnFWvnrK SCN 4 �s l�1, 1 �• , 6" I = 65.08 5" PV STY OF ANACORTES OWNER: 6" INV= 65.08 5= 0. JDO I 30.0 LF scN 4o Pvc o1- LANDED GENTRY 6'SEWER (E) EXIS5= T006 CONC. ss s= 0.0100 1 6 S 504E NG70NHWA N r: r I > 98�360 - �, ,. ,. FLOW- — --- o— _ _--_ - I fir-, �. _ - - - - ;; �� .. IE (E 7 CONC s�o'nLroN SD B : ) Ia2' — 1 _ — Ct C' < . ) 755 9021 ALLEY o IOD.O LF SCH 40 PVC no I 1-?,- " `, •- .1 BUILDING: 6` INV= 66„38 S= 0.0100 EXIST I SSMt'((E} _ Io4 s2' _ GRADE -1 40.00' I - UPPER L£ L AREA- i,098 SF _ _ .I GARDEN CAl f TOTAL LIVING AREA- 2,�F I EXIST. 48" SSa!N Driveway Area: 1,235 s/ — Rlld= 7013 GARAGE - 855 SF '- INV=; 6188 Infiltration Rote: Ono 0.997Ar SOCO, j SO I SD SD SD so I I Size: 8% x 1,236 sf a 99 sf SITE: 69.7 J pRPI� 4'x5o' INTZLmATICW TRENCK o Flow I TYPICAL g0 FOR ROOF DRAINS, IADDIF!£0 O I use 100 s1 EXIST •IP PER DETAIL ON SHT. 2 OF 2 a - GRADE OF TH£ SMALL PARCEL ' - STORM PLAN. �' ZONING: = - - f0.00' --! 50.00' N -I I I R2 - RESIDENTIAL LOW DINSITY i's' ..TCJ) I i�d'�p• '3 R SIGN ( } ( DOWNSPOUT INFILTRATIONCALCSr IM� � o ' � w Roo/ Area*: 3,336 s1 WITH CITY GUIDLINES SIOEYAROS MIN 5', i5' COMBINED G/r� ' , 70.00' - - `p Vol. III, 3.1.! Downspout Infiltration Systems: REAR YARD AZ 30' V r� • OS Os /1 OS as p / ( ) Length of !n sa d, tarry FRONT YARD MIN 10; 20' GARAGE /I I 6" CA57 IROP! CLEANOUT - 3 I SoNa:: Flna sang loamy sand e. Y �. cap — 4' SS SERVICE I FCR STOR7:f DRAIN, Fr u 1 J 0 S= 0.0200 MIN. WNTH SIOFWALK :r -1 30'(L) x 21(W) per 1,000 s.I. roof area DECK (NORTH)20' REAR YARD Rr,+,i= 77.00+/- I HEIGHT: 11I G� I I I BUILDING SETBACK DECK LINE " I'VV= 65.38 Using trench width of 4: • I 4/2=2 MAX. ALLOWED: 35' 30%2-15 PROP SE-D:HN () / 1—_ — — I I o5 ' ( W F Use ;SUN x e!(w) per 1,000 s/ roof ARKING: `✓ VVV L I • OS ) ( 3,336 aI�l,o00 s! a 3.34 C 3 !N GARAGE 3 IN DRIVEWAY 1 it h / - r 3.34 x 151f • 501/USE: 50If �_ o y /fit 0' / 2 V 0 "i LL infiltration x 50If(C!) x�.IN(H) (Stooge) ✓ �, `- - �1f s I 02 15th St . ( w *Includes area a,t to calms, including LOT COVERAGE covered polio & covered porch. / BUILDING AREA: 2,851 S.F. / hp (WEST)8'SIOF. __/ ES: TOTAPORL AREA: 3,060 S.F. ( � YARD BUILDING 'o- I L� �/ /� SETBACK LINE m 10' 0 P o ¢ •e LOT AREA: 10,475 SF,1 (/ ,' I 'd, O W w LL 1IVJ]/�1yI C I ig o PERCENT COVERAGE: f/li( � li� +l I• I x� re �S I_ I v o I I RESIDENCE 3,011 / 10,475 = 28.72: • 1 CM hESlf Cl: 1I � -/I o �-I w MAXIMUM ALLOWED: 35.0X + . /f GAF�IGE I - - - - - 1 w w IMPERVIOUS COVERAGE 0 L I —Z — Y ) us us BUILDING: 2,851 S,F, C r 1 I I , ADU WALKWAY 166 S.F. ...t 4 t �) /I I p%� I it o j� MAIN WALKWAY. 40 S.F c it 17- e /II AOU PORCH. 32 SF.VVV rMAIN PORCH: 128 S.F.I — PORCHL- I �I �� ADU DECK: 0 S.F. T �/+ N�PI [ ni] ( MAIN DECK. D S.F. -r �J / n — I I. �� — — — I — I — WALKWAY — I I I I - — rOTALWAY 3,954 S.F.7,37 ri I WALKWAY I I LOTAREA.10,475SF, I rl.Co' 132.00' 20.00' (EAST) 20'SIDE SIGN E " t;+All + + Y t� YARD BUILDING ( PERCENT COVERAGE: 0 — - - —/(pA_ — - I I I SETBACK LINE ,J � ' 1 3,954 / 10,475 = 37.8% ki "J ` (SOUTH)20' FRONT YARD N ICr) ,�y A I BUILDING SETBACK LINE I _ Od r �/ I i f /9 f�, I —IRA! ' PROPOSED 100 S F. I EXIST r D KI1+c1'i iil' I RAIN GARDEN DRIVEWAY GRADE I DRfVEVW'HY I 172.9 I 1 I +4 _ J I G�SDE I — — —' — — — } ---._ ' w lNNN CC r — 10.6T 70.0012425' — iii( a1' r I — WM (E)I I — to4s k,l� _ ADA \ ,! ul I \ �• r UTILITY RAMP `i` 1�/ I I' I c I l POLE(E) E / J i'�)T I 30 11' -- 20.00' - - 4.5.94' O/ \� V 17 - I + ! /I `S� P�K�Ei / \; \. 1 GRAPHIC SCALE / I [ ,1 • DRIVEWAY Y jr� AC (E} / `` SIGN (E) - — _ - - - - - hi - - c--) I _ _ / fo o 5 10 20 6 WA{E) I ( IN FEET • -: :. t I Horiz. Soak: f Inch )= 10 Feet STOP BAR(E) PADILLA ADU EDGE OF PRV (E) .J) 3-CAR GARAGE CENTER PAVEMENT (E} - - - - - - - - - I. / in.;II 15TH STREET ( -' - - c_n - - - - - - - - STOP BAR (E) 16'WA(E) ! . it -- - -- .. _. F l _- - - L• I -- - - - ---- ;1I---- ----- - f;, l - . . - __ " I I i _ - - _- - " 1 _ - - "- I - --- - -- ' „ (- - -- - ------ - --- •'' I. _ , " L ( _ 11t_ - SITE PLAN -- — — — - - SDCB {E} - -_ .- - - - - - , ti};:VALVE (E) SEE ENGINEER'S / \ I PP) ' • PLANS FOR ALL I ram:_, — — - - - - - 220215TH STREET • T- {t' / ' ANACORTES, WA FRONTAGE - IIYIPROVEMENTS. I I Dltl'.+Et".4sY/P+,P.Y,ING ' bN \ •• WM (E) I SDCB(E) ISIGN (E) \. I I 6�WAE) �_ _�� ' �/ / : •� ' - - - - • - - - - � ' W . I ;r / JOB N0: PLAT OF "48 NORTH" I C _ \ -\ I ` . I FIRE ', I ' — DESIGNED: LG I Ir::+4. ?i.,• I (E)HYDRANT \1 It1 1 � / I DRAWN: 1 I 11 / / DATE: 08/28/2017 I ', H 1 I y !l, , I SHEET 1 of 1 . . I ABBREVIATED LEGAL DESCRIPTION: CvSrS Tnlo9,0 a THE EAST HALF OF LOT 17, ALONG WITH ALL OF LOTS 18, I, I 19, AND 20, OF BLOCK 206, AS PER SURVEY RECORDED SDMH (8) I', �— UNDER AUDITOR'S FILE NUMBER 200303170356, RECORDS I SDC8(E) OF SKAGIT COUNTY, STATE OF WASHINGTON. SANITARY s£I:ER SERVICE � LANDED GENTRY — HNF POINT OF CONNFCTION I EXIST. GRADE= 69.0 II AND G U Al \I (.1N I 'I 1 L.5 BMP C233: SILT FENCE c° I:NV= 62.55 PERIMETER-SILTFENCING 4' INV- 62.63 �\ { TO PROTECT DOWNSTREAM i' :. CY I GENERAL NOTES PROPERTIES I OWNER: - - - 9 II LANDED GENTRY G SEWER (E) tx's l 6" CONC. SS FLOW I III i 504 I TO ,FAIRHAVEN S= 0.0060 98233 TON, WA I 1-(360)-755-9021 ALLEY -- ' III = --- - f702 - -� -.,- BUILDING: — ; L— SsM (E) � LOWER LEVEL AREA- 1,098 SF - -- 104.92' ------- -- GRAD o.00' II UPPER LEVEL AREA- $97 SF EXIST _ I it TOTAL LIVING AREA- 2,533 SF EMT. 46" SS5!H — �.� r_r _ _,_ , •_ _ _._ _,_._._,_._ �,_•,_ ._ ,_,_, � ',j !Nv4 6186 GARAGE - 855 SF RIM= 70. I.r SITE: • Y 1 'a-.. 69.3 2'x4G' TtIFn IRA No;1 rREn'c±f _ h • Far ROOF DRAINS, MODIIu.n I I TYPICAL EXIST PER DETAIL ay SHT. 2 Or :46 I ' i ZONING: I. GRADE of MC 54fALt w.RCE+• R2 - RESIDENTIAL LOW DINSITY IG570.4R1 PLAN _-._ I BM? C121: — �rP (NORTH)20' REAR YARD �j —I SIGN (C) I S£ALL SETBACKS IN COMPLIANCE Si II - OUILDING SETBACK LINE - o U I SIDE YARDS MIN 5, 15' COMBINED WITH WY GUIDUNES 70.00' _ u (, 36 cu' ?__ c, - 34.00' - yap w REAR YARD MIN 30' I0•o0' FRONT YARD MIN f0; 20' GARAGE BMP C233: SILT FENCE I di " • as Os o PERIMETER 81L1 FENCING ING �o, ° - 4 4" SS sFRMc£ ��; TO PROTECT DOWNSTREAM UNCOVERD h° 0 S= 0.0200 LaN. PROPERTIES DECK UNCOVERD (` I;Hairo we'll HEIGHT: (P) DECK �\ I I y II i MAX. ALLOWED: 35' PROPOSED: UNDER I 0`'sr— ' ` PARKING: ` �0`'` i ) z II Q 3 IN GARAGE, 3 IN DRIVEWAY z . � P , • 250 �� = I ' LOT COVERAGE O� 15th St. �� ti I w I , BUILDING AREA: 2, 16 S.F. PORCHES. 160 S.F. N SFR (P) Jv I1 III TOTAL AREA: 3,011 S.F. (WEST) 5'51DEI I Ui -- ADU (P) In , LOT AREA: 10,475 S.F. YARD BUILDING 'v I4 I O5Z� II ry' �; SETBACK LINE ai o {Qgy IJ V� ' ZW ��f. I POWNSPOIIT INRr JltanON CALLS: PERCENT COVERAGE: ! K "( ; Q w I l" I W i I ' ROOF AREA*: 3,336 S.F. 3,011 / 10,475 = 28. 7C es visi ■ <� '�' ) i w MAXIMUM ALLOWED: 35.0% oa I w w I I� USING AN INCHES PER INFILTRATION ASfALLO D IWP? M 7NE , I / GEOTECHNICAL REPORT PREPARED BY GARAGE aD. p Ir DEOERU/NED THAT IT YALLLLG7iXE HAS F OF IMPERVIOUS COVERAGE (P) ° , T w I i 2-FOOT WIDE x 2-FEET DEEP INFILTRATION - / 4 J ! AT 3-FEET A SURFACE, ELEVATION SET BUILDING.' 2,851 S.F. I AT 3-IrEET BELOW SURFACE IS NECESSARY Y w TO INFILTRATE 100X OF THE ADU WALKWAY: 166 S.F. y a I o POST-DEVELOPED RUNOFF WATERS MAIN WALKWAY: 40 S.F I w GENERATED FROM THE NEW 3,336 SF, ADU PORCH: 32 S.F. �' ,r{t HOUSE ROOF AREA. • • ; �. — MAIN PORCH: 128 S.F. 0�• ' _p f AS NOTED WITHIN THE WNNM MEW ADU DECK*: 0 S.F. I DRAINAGE MEMO. REARED BY STORMRIRJIK MAINDECK*. 0 S.F. . PORCH 1TOTAL: Z,� - .+ •-- _. / \ I ASSOCIATES FAO�RSEOfLROPO HOUSE 29.ir+s TOTAL: 3,954 S F i PROJECT, IT IS NOTED THAT ZERO CFS IS WALKWAY (P) , I RELEASED INDI AWING 1100X NFILIN TRATION LOT AREA; 75S.F.I - = BMP C233: SILT.FENCNG E I HAS BEEN ACHIEVED USING PIE PROPOSED DOWN STREAM SIDE WALKWAY O • —(EAST)20' SIDE / • DOWN STREAM SIDF. OF I TRENCH' PERCENT COVERAGE: YARD BUILDING / STOCK PILE I *Includes woo out to eaves, Inducting 3,954 / 10,475 = 37.8% - IO.GG' - - 32 .',17' - — — - 20.00' -- SETBACK LINE SIGN (E) ' . II covered patio le vowed porch. BMP C233: ' MULCHING (SOUTH) 20' .7. �• /J LI I I / 1 * PERVIOUS BELOW SILT FENCE — SAP G121 ' FRONT YARD - - N r •" WITHIN PROPERY BOUNDARY i a 4 l *� I I J 1 I (1,237 S.F. TOTAL) �� BUILDING ` I ' SETBACK LINE / SOIL STOCKPILE 72 s Eros un Cculwl No!00 1a Rcc denEo!Conuucri.n •CJty of Arusgorini ! DRIVEWAY 1 4 LOCATON EXIST (P) I COVER WITH GRADE i A Eroxn:: CurdcA8tstnWrw(ton:urdr''ucdrnr51hauhi:IsiIauslw:Ilwaanplt4breplsoplw _ !" _, ,. / PLASTIC DURING __ 'b, ary .a,.nlnn:iureL,d. �` __ • H The e•ouon cmt.W %hat he bison^.Inn onm n day nra froune•d to moot the anurM:n9 I BI'VIP C105: STABILIZED — S`ORM EVENTS, I I i _ 2 cnrldi(ons as ncudrJ / C the 51mm Amin sysmm Ihn'l tc cklancd Oa y(Ssd'en T•gr 3). All dca+nege systems ate;be ✓ CONSTRUCTION ~`i I BM D C123: PLASTI % ,�, ,lennc J to Ow aawFlanu of the Clly of Anacdttas pier loam:Mance of the gated T2 i _/ i E '4TRANCE - I COVERING) ' . ' 1,(tit 0 Stali'Ired ce reith !Ion en!mnrs_, and roads still he inslnnrsl of Inn h:.jruJruj of cnnstrucl ,o a � •uid.naintamod during Ow duration W the (mint Additional Mawros may kis!squired suol EXRIST AOE (SIZE TO FIT) C1.00ti _ 'i n•.wash ads W ensure that n0 aved areas rep kept dean fro m:k115 N:n»rd to onto,mix) ---. �- ----- _- l1TILIIY •i'Wa wadi WM (E) . . --k._ . o 1 ,1, POLE {E) E AnyM'hi erf coed that MI net tin distuttnd for Ma(2)days during the NM ic,san of WWII - _--__ - —.— ,04.9 _ t—. _. _ _ . .__ .. _ . .—. _ .— a_ 0 I `` 't` I/)days•m the dry scason shall b: immedlnloly lttbfiod allh the apf9vrnd ESC mutirods •� 1 �, wl ADA hstofolg rnuching. Paakwrrrirg rz ) t ~ . Y L1LCHt`�G U1ILITY - RAMP ) \ \\�, •. F Tno(2)weeks guru to 1hetr_gin-all of the Viol%omen (Octctrr I).all dlsu'tcd croas sha!I l �; M POLE (E) ...- be s,\ _ _ _ iO.UU. _ -_____—_I— 45.94' .1 'mimed In Idrndly u4,xh one!. pan hp smart/h pfrtpnrasrut for tiro ulsln.m!ns Disturbed - — 30. 11' ---- ^--- MP C 1 -- ----- - - (E) \ r areas shag be seeded wild n one 11)xeck n1 the teg°Aul.og oflho NV:coasen.A*WO map (A!Ax) �_• _ el tic.su areas to be tended and snasn ornos to rona'n uncovmnd rha'I Itosublrhlod to tho ti I 1 ______ ���� ° ' � GRAPHIC SCALE Pngr,t k1,an-,a<r, The Project Mar tiger con rega re scod!n91n addMor•al areas in WJm to C: - ---- ' -"-�-'- _ pwh•U widow v,:,tas, ultaccnI repelled nr dr•sha l WI Iles _ _ _ DRIVEWAY _ G Prna Kos for sn Erosion Control di d;, L me sut:,ucl W a$:i06 to SIDW Era under ChaPWI - - - - ��- - - — — - I - I. _'1 SIGN (E) -- - - - - 10 0 _5 10 20 APRON - - — 1766-PeoalCes for Violation. Ecdt day 4,con !Mond a edfacnt sio'doen. - - 1.1 - — � ( IN FRET 6'WA(E) BMP C103: HIGH VISIBILITY Moritz. Scale: 1 Inch = 10 Feet FONSTTUFENCE- STOP BAR (E) \ TO REDUCE RISK OF PUBLIC CONCRETE DRIVEWAY BMP C703: HIGH VISIBILITY - - N. EDGE or— - ENTRY INT CONSTRUCTION SURFACE TO BE CROSS - - — _ J PADILLA ADU etll /` PAVEMENT (E) SITE SLOPED 1% MINIMUM TO P1 D REDUCE-RISK OF PUBLIC • PRV (E) _ PROMOTE RUNOFF TO BE_ ENTRY INTO CONSTRUCTION _ _ _ _ _ _ _ _ _ _ 3-CAR GARAGE CENTER DISPERSED ONTO ADJOINING l' r 1 ' — sroP BAR (E) Is' WA(E) 15TH STREET LAWN / LANDSCAPE AREA. SITE • I _ I EROSION CONTROL PLAN SEE ENGINEER 'Ssoce (Ej �• ' VALVE (E) & LID IMPROVEMENT PLAN (iYP) PLANS F DR ALL P56250 FRONTAGE 2202 15TH STREET IMPROVEMENTS. I I - r. _p _ WM (E) - SDCB(E) , SIGN (E) H . I 6" WA (E) _ ANACORTES, WA • L ' ,, JOB NO: PLAT OF "48 NORTH" FIRE , a DESIGNED: LG 0 i r 2 I T' , YDRANT S I DRAWN. OCT 1 30 I (E) I I. DATE: 10/02/2017 Pi ` — - i STiEET 1 of 2 SDCB(E) I I ? I ' o"' 'ALLEY "" f r I 104.92' - 10.2 �; 40.oo' _ GRADE SIIMMINIMMIll illi - --- - - -- — - 1ilb :� � LANDED GENTRY 69.3 HOMES AND COMMUNITIES EXISTE 3 0 'x46' IN ILTRATION TRENCH o ; `S r F041 RO DRAINS, MODIFIED • '� ER DE IL ON BHT. 2 OF 2 j revcE(E) 0 7-- ,(� PLAN. ' ' S� N. �P SIGN(E) I i ABBREVIATED LEGAL DESCRIPTION: (NORTH)20' O BUILDING SETBACK LINE o _ THE EAST HALF OF LOT 17, ALONG WITH ALL OF LOTS 18, 70.00' 19, AND 20, OF BLOCK 206, AS PER SURVEY RECORDED - O N i. f UNDER AUDITOR'S FILE NUMBER 200303170356, RECORDS J.-OS36.00' 34.00' ��V_._ 10.00' 11. I OF SKAGIT COUNTY, STATE OF WASHINGTON. r o �a �a� os . 1I I pC' VO O 4" SS SERVICE I I UNCOVERD (9 0 S= 0.0200 MIN. I 1 I (I)DECK 6_.� _ _ , 1 / _'1 DECK 0 • .95. 05 f 1 ;I SHED o /VV. I -- -- -- —- -!I 5rj IIIIIIIIIIII � I'I;I r , CITY 1 2. mil. Y OF ANACOF TES(E) 22021 ADU(P) WU 1O aI: lircl k wZ i d SFR(P) 5t1St ? EAST20'SIDE( YARD BUILDING SETBACK LINE tl 1f ,_i Go 2 ---.P �' n) RESIDENCE - n i tri be 3 if) aLL Zwo 201; 6 (WEST)6'SIDE 95 fl YARD BUILDING 7(11: a 1 1 7 wg _ SETBACK LINE J=i, � 3 tI GARAGE 0 I (P) 4 1 i • ' � w VS (SOUTH)20 FRONT YARD SIGN(E)BUILDING SETBACK LINE 1 Pe 1ct4IA _ i Z xvcwAY lJ j i �(rr I o�cH —y �� �T - Li Ill I I I (P) WALKWAY(P) a i `D_ VD wAIKwAY(P) t• X ALL) N{ .i to -- — A 1l 18.00' I 32.00 I 20.00' 1 SIGN(E) 1 L. i Z L I r Oj j WALKWAY(E) I ; I I U) Q - ---- - - - - I N N � i I �� Li I GRAPHIC SCALE g}� , 6 s s .2 0 ,,,,- I I„{ ( IN FEET ) 1 — • -f i— # Norte. Seas: f Inch — 6 Feet .// PADILLA ADU ,^ �'EXIST 2.6 I -.., 3-CAR GARAGE CENTER • AGRADE / 1 LANDSCAPE NOTES: DRIVEWAY 1 (P) / -I , PROVIE (I) TREE (EXISTING OR ADDED) PER 1,000 SQ. FT. OF LOT (11 TREES 70.00' 24.25' j LANDSCAPE PLAN MIN. - VERIFY LOCATION W/ BUILDER) W/ A MINIMUM 2" CALIPER (PER CODE. 104.9 POL UTILITY) / , 1. I N P56250 TREES PROVIDEDWILLA COMBINATION OF DOGWOOD, RI wm(E} � .{ 2202 15TH STREET REE BE B D O D, ALASKAN CEDAR, 07-ADA ) ANACORTES,P 1 WA VINE MAPLE 4 WESTERN HEMLOCK (VERIFY LOCATIONS W/ BUILDER). VERIFY , �(E) // [ TREES TO SE REMOVED IN FIELD W/ BLDR. IF APPLICABLE. / 1 /7. 20.00 45•s4' %;�` x ` - 4MAX_�_ - \ / (� JOB NO: 0 DESIGNED: PROVIDE LANDSCAPING IN A COMBINATION OF SOD LAWN AND PERENNIAL - - _- r_ i ; DRAWN: PLANTING BEDS TO COVER A MINIMUM OF 20% OF THE LOT (2,095 SQ. FT.). DRIVEWAY I / ._AC(E)/ I j DATE: 10/0212017 VERIFY LAYOUT W/ BUILDER. APRON(P) Q 15TI 4T 1 — - J J' - - !, - I _ SHEET 1 of 1 1? r,,:r:cf" RESIDENCE I I I I I I IctIt:Ltl:';h IIGomm - — L I i - - - ! ila - ---1 I — — - - -- fiNb I I 1 I -- SDMH( 1 ,' SDCB(E) ABBREVIATED LEGAL DESCRIPTION: ] I - LANDED G F: N T RY SANITARY SEWER SER41C£ vi _.0 1 � :I - ---L.'.. THE EAST HALF OF LOT 17, ALONG WITH ALL OF LOTS 18, EXIST GRADENT =CONNECTION 11 O N E S AND CO N al UNIT] ES 19, AND 20, OF BLOCK 206, AS PER SURVEY RECORDED 6"INV= 62.55 I UNDER AUDITOR'S FILE NUMBER 200303170356, RECORDS 4"INY= 62.63 + . GENERAL NOTES OF SKAGIT COUNTY, STATE OF WASHINGTON. FENCE—\ I 1 o OWNER: LANDED GENTRY li 504 E. FAIRHAVEN EXIST. 6'CONC. Ss I BURLINGTON, WA 6'SEWER(E) S= 0.0060 I 6 SE(E) 98�33 ;,, ss FLU 5 —755-9021 s ALLEY rr EXIST J 3 `.,f.._ BUILDING: EXIST I SM (E) LOWER LEVEL AREA- 1,098 SF Is 104.92' GRADES 40.00' 11_ " TOTAUPPER LIVING AREA- 2 LEVEL AREA- $533 S✓•\ I Exrs•T. as ss6rHSRIM 70.13 GARAGE - 855 SF ' '�,I INV� 6188 ` y BMP T720: INRLNRAPON I i f� TRENCH: 2x4b'INFILTRATION �_ SITE: q TRENCH FOR ROOF DRAINS,ON 6. TYPICAL EXIST0 o EO PER DETAILOF BHT. ZONING: EXIST � PARCEF L STOF RM E PLAN. R2 - RESIDEN71At LOW DINSITY GRADE _ n - I 46.00' I SETBACKS: rrrir-\ 1. S�taP�� I sIGN(fi) ■��, I ALL SETBACKS IN COMPLIANCE U I ' WITH CITY GUIDLINES �, „� SIDEYARDS MIN 5', 15' COMBINED 70.00' o a I I I REAR 0' YARD MIN 370; 20' GARAGE H 36.00' __ __ 34.00' y0G 70.00'-� o- u, ' FRONT YARD MIN ic: GC OS �Q OS OS — Q 000 4"55 SERVICE .7 li 0 0200 MIN. I I HEIGHT: DECK (NORTH)20'REAR YARD \ MAX. ALLOWED: 35' BUILDING SETBACK LINE DEC PROPOSED:UNDER 0�0{ - -- . - -- - I I - - - - PARKING: ---— , I I w I II 3 IN GARAGE, 3 IN DRIVEWAY Oy I I z_ 1 _ L I 250 I g LOT COVERAGE SHED -- - - - ---- ' 02 15th St. - [ I / 1 BUILDING AREA: 2,851 S.F. I w 1 PORCHES: 160 S.F. DECKS: 272 S.F. (WEST)5'SIDE - ,, I TOTAL AREA: 3,283 SF. YARD BUILDING 6�?� I ' E. LOT AREA: 10,475 S.F. SETBACK LINE / U o - ¢ ui . al I oo uth W z LLp v • 1 , w YYi w ; PERCENT / 475GE: 31.3% 02 RCI.IUENCL o p f' MAXIMUM ALLOWED: 35.0% N — - — - GARAGE u a■ } z I \ W ___y I 0 I 0s 3 1 I 7) I I O . .. •:-){ ¢o I [ LI 12 N N I I I L I PORCH L I —„I } 1H I ; II ■ / 1 I WALKWAY I r L -� -lL - - - - - - - - - - - -- J- I- I- I WALKWA 11 I-- - - I I 18.00' 32.00' 20.00' (EAST)20'SIDE I SIGN(El I v,'AI.IY@AY- I • YARD BUILDINGIII _- - - -- -- - I N {SOUTH}20'FRONT YARD N SETBACK LINE U I. BUILDING SETBACK LINE I I 20'• RESERVED FOR 73,0 -\\11;,na:;r,Y -SHEET a.O 1 DISPERSION- DRIVEWAY EXIST I I I PER 86rP T5.12 75.12 GRADE DRIVEWAY I l I I 72.9 ! / 1 1 _ I ' EXIST GRADE 1 _ vi a' / f w O -10.67' I- - 70.00' - 24.25' K. / ; - `\ Io .` POL UTILITY Z ( 104.9 - --- -- - \ I UTILITY ";' RAMP / J I\/ I 30./r' 20.00' 45.94' POLE(E)„.‹ E) ;/ , • ' a I r - - (arax� i { \ GRAPHIC SCALE l DRIVEWAY �� ~ fO O $ fO 20 APRON I �AC '7.E 1 1 \� - ) -SIGN E ( IN FEET ) 6"WA�,(E) Hertz. Seale: f Inch 10 Feet STOP BARE) til0EDGE OF J Ir PADILLA ADU PAVEMENT(E) PRV(E) -l I I� -, („ I` y. 3-CAR GARAGE CENTER 15TH STREET 7..---STOP BAR(E) 16"WA(E) I ' I__ +'[ „I ,, I ! 1 I I_ , i -- - - - - - - - - - - -- --- - -I—l- _ _ .c - - ---- SITE PLAN q: - - - - - - - -- - I - - - - — "-`� 1 `I, VALVE(E) SEE ENGINEER'S I . (TYP) I P56250 PLANS FOR ALL SDCB(E) I _---- - 22Q215TH STREET • PARKING FRONTAGE . I N. I I ` /�i�r~ I ANACORTES, WA IMPROVEMENTS. , + II I Okl'JEl1'i,Y J Pr''.I:ll'. __---- }_I WM(E) I SDCB(E)I I SI3N(E) '� ( I - 6�WA(E) I I � \ I /. —- — -— - (I• I I /� JOB NO: 2202 15TH STREET FIRE l I I I I / --- -- DESIGNED LG 1 • HYDRANT 11 I /// I I-Ivl:' i • 1 (E) \` 1�S (II I DRAWN: ( I I • , ;� DATE: 11l09I2017 ', i ' I __ -- //1 / SHEET Jr 1 0f 1 i::_iii.!=I'ICC i I , I I l I I RcSl=Ehlt.'❑ s— ABBREVIATED LEGAL DESCRIP TI thN: I I _ iiiie — i -THE-EAST HALF OF LOT 17, ALONG WITH ALL Ofr LOTS 18, , or ..,,, liVit M , i 1 a 9—ANb 20, OF BLOCK 206, AS PER SURVEY RECORDED - - - - - - _i I SOMH ( ). SDCB (E) UNDER AUDITORS FILE NUMBER 200303170356, RECORDS %` a OF SKAGIT COUNTY, STATE OF WASHINGTON. i' 1 _ — -- --_ ( _I LANDED GENTRY SANITARY SEWER SERVICE I �' I NOV 2017 ( tIIO \ILS AND COhINIUNITIL• S UNE PO7NT OF CONNECTION EXrST GRADE= 69.0 BMP C233: SILT FENCE s^ ,Nv= 62ss I ; PERIMETER SILT FENCING a 1NV-. 6263 TO PROTECT DOWNSTREAM -_,fc: iC; --. I j GENERAL NOTES PROPERTIES "� Exrsr. 6^ conic. SS qu-il `' I CITY i OF ANACORTES OWNER: LANDED. GENTRY 6' SEWER (E) s= o.0000 Fcow I 6' SE (E) 98233 BURLINGTON, WA s _ i , .- 1-(360)-755-9021 ALLEY a r12' I I I y ' BUILDING: S MF(E} LOWER LEVEL AREA- 1,098 SF ,04 s2' EXls� ao.00' I UPPER LEVEL AREA- 897 SF TOTAL UVING AREA- 2,53-3 Exrs'T. 48" SSMH _ ___ _ RIM 70.JJ GARAGE - 855 SF T-i-Y�Y-S-,-�•�.•-[— .—, )^,I—[aims.—I—[�,I-At,�z —f—, S . ' '!/1I --. - - _•—A.�.� }�.— �aaa ri INV 61.88 `n BMP T720• INFILTRATION I I 'i 1 � � TRENCH: 21x46' !NFlL IRA llUN SITE: o TRENCH FOR ROOF DRAINS, o I TYPICAL ,l 69,3 0 R MODIFIED PER DETAIL ON sm. o 1 EXIST '' ti 2 OF 2 OF ME SMALL I GRADE C42i. MULCB EPTN N u� I 1 PARCEL STORM PLAN 46.00' I ! I ZONING: RESIDENTIAL LOW DINSITY I BMP pOST-CONSTR II -rill r} ^ gp1LQUALI(Y AND sdtA?0 H' II - SETBACKS: SIGN O ALL SETBACKS IN COMPLIANCE (NORTH}20' REAR YARD U W WITH CITY GUIDUNES • BUILDING SETBACK LINE ° N . REAR YARDMIN53015' COMBINED 70.00' FRONT YARD MIN t0; 20' GARAGE 36.00' ti 34.00' t9°�' r0.00' .� BMP C233: SILT FENCE I o as — — os Gs q I l PEKIMh I EH SIL l FENCING I pc' °° I Cl HEIGHT. 5 UNCOVERD a SS SERVICE r,° `�� MAX. ALLOWED: 35' TO PROTECT DOWNSTREAM0 PROPERTIES �� I DECKP) 05= 0.0200 MIN. UNCOVERD \ PROPOSED:UNDER — — -- D p K PARKING: I ( 3 IN GARAGE, 3 IN DRIVEWAY i 1:11 , 1 - -- �I V - I �5 o ' o= UJ I �® L 0 T COVERAGE SI1E0 P t0 Ol - {L'i 250 I „�, odUQ �% 2 a + 1 BUILDING AREA: 2,851 S.F. I J _ O 02 ��� ��. prn0 Z1 PORCHES 160 SF. LJ z ix DECKS: 272 S.F. — — — — - ' ROOF FAVE LINE, TYP P w - - �T = Z u, I TOTAL AREA: 3,283 S.F. N SFR(P) Dpy�. I I wcd LOT AREA: 10,475 SF. (WEST)S SIDE V ADU IP) 2 '. 1- YARD BUILDING } ' I • • CO-I - r,N Co PERCENT COVERAGE: SETBACK LINE �� �S jpQ W DOWNSPOUT INFILTRATION CALCS; 3,283 / 10,475 = 31.3% 8 {Qi -V C I a LL t tr :I ':rr;r;r i I rT� �i U • -p w o ROOF AREA! 4376 S.F. ill w v w rtESIGE iC•E MAXIMUM ALLOWED: 35.09 x C u'ip I1 r L9 I USING AN INFILTRATION RAW OF 6.3J C ¢ CO F- z w w INCHES C PER HNlCAL REPa,QT PREPI ARm BYIN THE {c i v GARAGE , CEdIEST FOR D1I5 PRG ECT IT HAs BEEN IMPERVIOUS COVERAGE (P) a ■ i 2-FOOTT lWDE x 2-FEET !NRL?RADON - _ _ Q WENQI HAVING A BOTTO1( FLEVAlION SET BUILDING,' 3,376 SF, AT 3-FEEET BELOW SURFACE, IS NEI SSARY ADU WALKWAY'*. 164 S.F. zz , IO INFILTRATE IOOR OF THE I j I Q o POST-DEVELOPED RUNOFF WATERS MAIN WALKWAY"h 31 SF BMP C233• - - - - . OS X I cf]uERAIED FxorA Tt1E NEW J,376 SF. ADU PORCH•".' 0 SF. I SILT FENCE s• I i — 8 NousE Roe` AREA• MAIN PORCH". 0 S.F. 0 • . •" AS NOTED WHIN THE tYHtrM NEW ADU DECK'!' 0 S.F. - ppp h INFORMATION PROVIDED KITIr THE STORM MAIN DECK": 0 S.F. Erosion Control Notes for ResidentlaLConsWctlon-City of I - 1 I II N N :`i ORAfNAGE MEMO, PREPARFA 8Y RANVIK & Miff DRIVFWAY�'rt• 690 SF Anecortes I ; �1 I I PORCH I II LI o ) A I ASSOpATES INC., OAIED SEPIEI/BER 29 jOTQL 4,261 S.F. —�� //\ 2017, FA4 PF(E PROPOSED HOUSL FOR ISifS ' PRO,ECb IT !S NEED THAT ZERO Fors 1S I- .- ,-.J i _._ram•\�—, , --1 I i L , _ / .:I _ ' , . +_ _ - • {.. r WALKWAY(P) , REIEtSFD NA THE RrSER uSEU IN 1HE LOT AREA: LI Bh1P C233: SIL,T ENCE MODELING, INDICATING USING INFILTRATION 10,475 S.F.A. Erosion Control Best Management Practices shall be In plat4 per the - - - --1—. I-_ ! 4,�124\'_,� — BM RI NWING U HAS BEEN ACHIEVED THE PROPOSED --accepted.site-plan pdoFto.any cegstrucUon start. 1 •_ j ! `•_;. I (EAST)20' SIDE TRENCH. I B. The erosion control shall be Insp cted once a day and nwdilfed to WALKWAY (") �. +` YARD BUILDING 310 K PILE�M• IDE OF I PERCENT COVERAGE: I I �' A �.� Includes area out to caveat, Including 4,261 / 10,475 = 40. 7% meet the surrounding conditions * needed. I 1 cowed I 8.00' ,32 p0'- ,; , � 2O.0p' - • ,� SETBACK LINE SIGN (E patio & covered porch. C. The storm drain system shall be cleaned daily (Section t�7 ). All " I - ` ^ PERVIOUS BELOW I,{G & r - % ) ( Ir 7r ,/ � . * drainage systems shalLba.GLeaned to the acceptance of the City of a ML1l CNti'7 RUC _ -- 5,, = (SOUTH)20' ? /j U ,� *f LESS ROOF SAVE COVERAGE Anacortes prior to acceptance of the project. — - -' N I BMP Cpo c•T-00149 I ill .� id �` r ' - I(. f . FRONT YARD N� �. j o I D. Stabilized construction entrances and roads shall be Installed at the (5.13 ( ( AND DEP I �c BUILDING �/ - OFFSITE DRIVEWAY 500 SF. aid ; ::: v QU -, l � \- I beginning of construction and maintained during the duration of the 5011 r y % I , _ s j .• 'i 1 ._ SETBACK LINE SOIL STOCKPILE ` I OFFSITE SIDEWALK: 470 SF. project. Addillonal measures may be required such as wash pads to I' , : I 72.6 o I TOTALTE IMPERV70 S 4,231 S.F ensure that all paved areas are kept clean. No mud Is allowed to I I •ORNEW/\Y f LOCATON EXIST i'1tf,r1'.AY IMPERNe S: 5,231 S.F. _ •1 COVER WITH GRADE enter onto City streets. = R \ / ( j / I E. Any soils exposed that will not be disturbed for two (2) days during the I I I . , ti ', I )K ! ! / PLASTIC DURING O. - - j I wet season or seven (7) days in the dry season shall be immediately E r ;/ ' ,: / -.• ./-- '. I BMP C1Q ,: STABILIZED -�'�► . � \ ;� .• I S-ORM EVENTS, I stabilized with the approved ESC methods (seeding, mulching, plastic I covering, etc.) II CONSTR CTION I i' I_: 1 I - • ( BM ' C123: PLASTI' l = L, F. Two (2) weeks prior to the beginning of the wet season (Octdber 1), 72.1 I ENTRANCE _r ! i COVERING) ° •,, I lt` 1 all disturbed areas shell be reviewed to Identifywhich ones 4n be EXIST I t (SIZE TO IT) r - , w GRADE I t , -I� ` g 1 I tt, \ UTILITY = seeded in preparation for the winter rains. Disturbed areas shall be Ia6T 7o cD l - 2 .25' / I 1 I li WM (EJ p 1 1, f POLE(E) ~ seeded within one (1) week of the beginning of the wet season. A • f04 s 12 sketch map of those areas to be seeded and chose areas to Iemaln I BM� T5.12; SHEET �, S N1NC' &,T ON ° — \, ro I I, \ �( uncovered shall be submitted to the Project Manager. The P ject f FLOW DISPERSION o- ' ' r 21' NSTRU DA J \ ' / 8 CO EpTH 4TILITv RAMP / \\ �/ \ Z Manager can require sending In additional areas In order to protect _ 0 00 �- 55. 13 I AND D ROLE (E) (E) NN J0 I,' - 45.94' (ZU� o ' . \\ surface waters, adjacent properties or drainage facilities. I I _ _ L!= f .(MAx.);_ r I, SOIL ill \ \,G. Penalties for an Erosion Control violation are subject to a 900 to $ ` _ - - r i __ .I O o P a - O \ \- j$1000 fine under Chapter 17.66 - Penalties for Violation. Each day Is o 1 __ T / considered a different violation. \ rr DRIVEWAY t T I AC (E) / - I SIGN (Ej - 91 APRON I i I o :. . - - — - - - - - - - -- - - - - - -- GRAPHIC SCALE 10 0 5 10 20 BMP C103: HIGH VISIBILITY I _ - 6^WA (E) BMP C103: IGH VISIBILITY - - NI • • I I : - K OF PUBLIC I CONCRETE DRIVEWAY i sroP BAR(E) ENTRY INT" CONSTRUCTION SURFACE TO BE CROSS r- ( IN FEET ) EDGE OF Horiz. Scale: 1 Inch. = 10 Feet SITE SLOPED 1% MINIMUM TO PLASTIC FENCE PRV (E) ' PAVEMENT (E) EN REDUCEWINTO CON OF PUBLIC , {—�v ` �� { J,I - �, I PADILLA ADU PROMOTE RUNOFF TO BE ENTRY INTO CONSTRI�GTIBN ! ;,; — 1 DISPERSED ONTO ADJOINING SITE :i - j � STOP BAR (E) 15TH STREET LAWN / LANDSCAPE AREA I !�� 3-CAR GARAGE CENTER 16" WA (E) PER BMP T5.12: SHEET FLOW C - 1 i - - ' — — I :' I - ---_-- - ---1 -- -_ "DES�ERSION - .-J „ - -- ----- - 1 •, _ - _ 1 :' _ J i 1 , �, _ l EROSION CONTROL PLAN - - — — I — — — _ _ _ ,:, r, — - -' ,;VA(LTVYEE(E) 11 " 1 / - 17 T•1'k & LID IMPROVEMENT PLAN — — — — — — SEE ENGINEER'S rr ,\ SDCB (E) PLANS FOR ALL j I - - - - - _ - P56250 FRONTAGE / , _ __ /%~ - — —� IMPROVEMENTS. r \ I i t� wM (E) ) socB(E) Dr:f/EVI.=',' : - '.r:aiDa l .sic;:' �` l 1 I. I a"wA (e) /�``� �- — J = — 2202 15TH STREET I 1 , I I, :. , '_ ..ter—= k ANACORTES, WA - - 1 I 1 JOB NO v 220215T STREET - i 1 I I \ I r' H -. .\ I I 1 ,"'- -- - ' ` .- 1 V I r,�� DESIGNED: LG N I FIRE .` /fir I DRAWN: I HYDRANT / I11:1'/LI",1•; I i (E) `�1 ' 1•. l ; �/ DATE* 11/09/2017 I i it / I I I j I, }+ ' If SHEET 1, l% SDCB (E) 1 - I r� III / / i 1 of 2 II I i !+ A. ©®li e III 1' MEMO CIIMEMBEIMB a 41h5t 9115 s1 rill,SI 9t115t , `z SkaplGwdcd ri\aiUI5pn LANDED GENTRY o I "F 4"DIA.RIGID none:S AND COMNGNITICS loth sl lino SI �, -I l,nh III nnh51 Misr,sl I011S4 HI., • PERFORATED PIPE --- r n FILTER o FABRIC 1115S1 1 i1.1 1 Nei SI IPnSt 1111151 11tnSI IIIIIS1 111".i 1' FINISHED GRADE n n 3 'A -Elli Id4lWsoal.,Ikla� -1III ,' i " .` SOP IL lJ 121hS1 I<':1,,, 1.'I,.;i (9 . O •�. c?r t zln s^ �� - C7 v w•I I I `Y mow- `'t a�iw gra e I aY'eY.aY 8f9 Safeway Anawrlas 2 St©,:ar,Grocav' ^ I I~•7•A It�C011.4 OOSOi'L I WASHED ROCK © ' � � ` a !' 1 TRENCH DEPTH 1VS ••• , BOTTOM ,-,,list umst lama lams) • III- I•_III—III:_ —Hi 11. AI ' 1 1/2"TO 3/4" INFILTRATION TRENCH SECTION A-A WASHED ROCK lam St lagr SI t•WI St IAw Si rim St 1.ah•. PROJECT SITE •tl o'1 41$0" NOT TO SCALE 2202 15TH STREET Lsgls, t6msl Ibmsl n ANACORTES, WA 1't"'.1 <1 L. n Arenue Mu15eMyp m 1C,n51 o 14111 9 • 'tie St Go'-,g le 'Adorer/York , 1 ii.`'1 1/d,5, ^' 171h SI 11-,:,1 17111SI NOT TO SCALE VICINITY MAP . 2202 15TH STREET ANACORTES, WA Figure V-5.3.3 Planting bed Cross-Section Figure III-3.1.2 Typical Downspout Infiltration Trench Plan View 4•Oki or 0•flosIble roof podolatod pipo drain �` ,1/ sump wIsolid lk legation Conch Itulcn — C� m — ol d¢In overflow Profile View 4'dgidot 0-ridable splash block porforalod pipo CB sump . $n \_� • A vdsolld rid Lode soil%mai a } 5. visible dark 1 °titanic nottof 12' I