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Home My WebLink AboutPermit File 4319 Oakes Avenue eitRUGST. 1 d ' r�� w�s�'�'S ��'' � �" , Storm Water Drainage Report �` . f , „41 i •imum Requirements 1 through 9 1 ' ENGINEERING DEPARTMENT 7 - .. , , c, / �ao1 ` -, /r`" 904 6th Street Anacortes, WA 98221 {� ., Is91t.. .off, REcts � . �'" www.anacorteswa.gov 7 :"ICOV`�.' OFESS10NA1.�, Official Use S . ( nformation to Inspectors) Required Storm Water Facility and other related requirements: ar B m-e --1- . i'3 — D eFiyo" D‘IaE.ac GwJNrZT i- s A - M tZ S- liras 'I e9.-s hn m"- x- t-(t',l-k ` 2. sex•,-TN r - I2S- EX12-10. I SSA o(--, S 43 15 c--Sr rL 'I Pt LL_-4-V Vef.11 tJ 1L&-r- al-Y 'IL- IN\ _$* - EllemexiT c1 Project Address: _4319-4401 Oakes Avenue Submittal Date: cfai.2-Co•le. Parcel Number: _P133694 Revision Number: 3 Permit Number: _BLD-2020-- Reviewer: �Eay 053cei-4 Acceptance Date (COA): 1,1•Zo.+E-VO FRONT OF REPORT: -�A�— Lohnt� S(4e,�1e 1 - � Submittal Checklist: (All items listed below are required for a complete submittal) o Cover Sheet (Preparer to Provide): Project title, Location, Revision dates, Engineer's Stamp o TAB 1: Minimum Requirement#1 — Preparation of Stormwater Site Plans o TAB 2: Minimum Requirement#2 —Construction Stormwater Pollution Prevention (SWPP) o TAB 3: Minimum Requirement#3— Source Control of Pollution o TAB 4: Minimum Requirement#4— Preservation of Natural Drainage Systems and Outfalls o TAB 5: Minimum Requirement#5—On-site Stormwater Managements o TAB 6: Minimum Requirement#6— Runoff Treatment o TAB 7: Minimum Requirement#7—Flow Control o TAB 8: Minimum Requirement#8—Wetland Protection o TAB 9: Minimum Requirement#9 — Operation and Maintenance o APPENDIX 1 - Survey performed by a Professional Land Surveyor o APPENDIX 2 - Soils Analysis (Volume 1, Chapter 3.1.1) o APPENDIX 3 - Model Soil Management Plan for BMP T5.13 o APPENDIX 4 - Determining Construction Site Sediment Damage Potential (Appendix 7) o APPENDIX 5 - Site Plan with all applicable information (Minimum Size 11x17 — 30 scale) o APPENDIX 6 - Documented Site Photos (North, South, East and West) e T . Stormwater Management Requirements: Version Date: October 7, 2019 Previous Version Date: February 20, 2019 o Refer to the 2012\14 Department of Ecology Manual, as amended in 2014 for further required information. o See also, City of Anacortes Municipal Code 19.76 for additional information • o See also, current Engineering Development Standards, Chapter 2- Storm Drainage for additional information. Project Description and Summary: Summary Table Existing Proposed Development Type Number of Lots 2 Lot Acreage in SF 24,833 SF Soil Type(s) Coveland Gravely Loam HG C/D Site Sediment Transport Score (High\Low) High 125 Depth to Ground Water Table (Feet and Inches) 16"TO 23" (See completed Soils Analysis(Volume 1, Chapter 3.1.1) Infiltration Rate during Rainy Season (Inch\Per Hour) N/A due to shallow water table Impervious Surface (on-site) 3,400 sf 9,310 sf Impervious Surface (off-site) 0 0 New and Replaced Hard Surface Total (SF) 12,710 sf Lot Coverage (Percentage) 0 53% BMP (Required Minimum Requirement 5) BMP T5.13 Post Construction Soils Water Quality Method (Minimum Requirement 6) N/A Water Quantity Method (Minimum Requirement 7) N/A Existing Site Conditions Summary: (Additionally, provide information on previous permits, if any, like Grade and Fill, Clear and Grade, topography, vegetation, drainage, Critical Areas adjacent to the site and how it may affect this project if soils are disturbed, Soils Type (Included in Soils Analysis Report), Erosion Problem Areas, Construction PhasinglSequence) The 24,833 square foot lot has an existing concrete driveway extending from Oakes Avenue over the existing pan handle of the lot. The existing 3,400 square foot concrete driveway is shared with an existing residence at 4317 Oakes Avenue and has a slope of 6% at the top to 16% at the bottom. The new building sites slopes from the back southeast corner of the site to the northwest corner of the site at an average of 9%. The site is grass with no trees. There are no critical areas identified on or near the site. The 48 North Plat to the east has an existing intercepting storm pipe running the length of the adjoining property line intercepting offsite flow from entering the site. The same is true for the single family home to the south with storm water collected and directed to an existing 8" storm pipe that extends through the center of this property in an existing storm and sanitary sewer easement and conveyed to the Oakes Avenue drainage system. Also an existing perforated pipe is located along the western property line that terminates in the northwest corner low point of the property in an existing 8 foot deep 6' square dry well. Developed Conditions Summary: (Additionally, to be shown on the site plan. Identify cut and fill areas, proposed slopes of all hard surfaces, proposed contours) The submittal is for a two lot short plat with a common access driveway also shared with 4317 Oakes Avenue. A preliminary layout identifies two new homes and paved driveway and parking area in addition to sidewalks and patios for a total of new and replaced hard surfacing of 9,310 square feet. An additional 3,400 square feet of existing concrete driveway will be Version Date: October 7, 2019 Previous Version Date: February 20, 2019 assessed for water quality treatment. The total impervious area to be considered is 12,710 square feet. The southeast corner of the site will be cut up to 5 feet and the northwest corner of the site will be filled approximately 5 feet. The drainage from the site will be separated to flow to two separate drainage system in order to not overload either system. Lot 1 roof and driveway drainage will be collected and conveyed through a new storm pipe run along the east property line of 4317 Oakes Avenue through a new easement provided by the property owner. This storm water will connect to a storm system at Oakes Avenue that discharges the storm water from the 48 North development and is a separate system all the way to Guemes Channel. The concrete surfacing of lot 1 (1,767 square feet) will be sloped to the north and collected in a catch basin along with the roof water from lot 1. Lot 2 will enter a storm drainage that already exists and currently connects to the existing enclosed storm system in Oakes Avenue. The Lot 2 driveway (1,278 square feet) will sheet onto the existing concrete driveway (3,400 square feet and total of 4,678 square feet) and sheet to the north and collected at the base of the existing driveway in a new catch basin located over the existing storm lines .A significant portion will be graded to accommodate the proposed homes and driveways. An existing utility easement for storm, sewer, water and dry utilities extends up the proposed new property line. Drainage Basin (2007 Storm Comp Plan —City websitetpublicworks\engineering\comprehensive plans): What Drainage Basin are you in? G5 Identify any downstream drainage issues (Storm Comp Plan: Yes. If so, describe: This site discharges to two separate existing drainage systems on the South side of Oakes Avenue. Lot 2 will discharge to a catch basin at the bottom of the existing concrete driveway that flows west in an existing 12" storm pipe for 329 feet before discharging to an open drainage ditch. After 60 feet of open ditch the drainage system is a closed system for 2,254 feet to the Guemes Channel that combines with the Clearidge drainage system and crosses Oakes Avenue to the north and passed through the San Juan Passage Development to Edwards Way and conveyed to the discharge at the base of Edwards Way at Guemes Channel. The system is identified as being surcharged and that the portion in Edwards Way was to be replaced. The Edwards Way portion has two separate drainage pipes with one for the Clearidge drainage and a separate one for San Juan Passage. Lot 1 will discharge to a catch basin at the bottom of the 48 North development storm system that is conveyed across Oakes Avenue and flows west on the North side of Oakes Avenue to Edwards Way and down Edwards Way for a total of 2,765 lineal feet to discharge at Guemes Channel. This system is separate from the Clearidge drainage system to Guemes Channel. Each system is over I/a mile long before discharging to Guemes Channel. Complete the Applicability Requirements — Flow Chart (Figure 1-2.4.1 Attached, Figure 1-2.4.2 Attached and Figure I-2.5.1 Attached) Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Figure I-2.4.1 Flow Chart for Determining Requirements for New $tuirit Neve Does the site have 35% Yes See Redevelopment Minimum or more of existing to Requirements and Flow Chart impervious coverage? (Figure I-2.4.2). No Does the project convert 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 Eoy native vegetation to pasture? replaced hard surface area? \\NO �S Yes Does the project result in 2,000 square feet, or greater, of new plus All Minimum Requirements replaced hard surface area? apply to the new and replaced hard surfaces and converted Yes No vegetation areas. Does the project have land Minimum Requirements#1 disturbing activities of 7,000 through #5 apply to the new YeS square feet or greater? and replaced hard surfaces and the land disturbed. No V Minimum Requirement#2 applies. DIME Figure 1-2.4.1 Flow Chart for Determining Requirements for 11111011 New Development DEPARTMENT OF Revised June 2015 ECOLOGY Please see http:7Aww.ecy.wa.gov/copyr ght.html 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 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 1 (MINIMUM REQUIREMENT#1) • 1-2.5.1 Minimum Requirement#1 — Prepare a Stormwater Site Plan - 1.3— Preparation of a Stormwater Site Plan - 1.3.1 —Stormwater Site Plans: Step-by-Step Note: The level of detail needed for each step depends upon the project size. Provide a narrative description of each step. 1-3.1.1 Step 1 - Site Analysis: Collect and Analyze Information on Existing Conditions Site analysis shall be submitted as part of the Existing Conditions Summary above. Part of the information in this step should be used to help prepare the Construction Stormwater Pollution Prevention Plan. Purpose of the Site Analysis is to provide for a Low Impact Development site design that is intended to compliment the predeveloped conditions of the site. A Stormwater site plan has been prepared showing erosion control methods for this site. The site slopes at and average of 9% to the northwest corner of the site. The uphill property is developed with all storm water being intercepted at the property lines and conveyed away from this site. An existing interceptor trench along the west boundary with an existing perforated pipe in drainrock bedding, discharges to an existing 8 foot deep 6 foot by 6 foot drywell located at the low-point of the property in the northwest corner of the site protects the downhill properties from storm water discharge. The existing drywell, although not ideal for infiltration,was the result of a compromise with the neighboring downhill property to reduce the impact of offsite storm water discharge. The drywell seems to be helping. A soils report was completed for the site by Linda Spicher. The soils report included in Appendix 2 identifies the soils as sandy silty clay Hydrologic group CID with a anticipated water table from 16" to 19" in depth. The soils are not conducive to infiltration with hard pan at the same depth as the anticipate water table. 1-3.1.2 Step 2 - Prepare Preliminary Development Layout Based upon the analysis of existing site conditions, locate the buildings, roads, parking lots, landscaping features, on-site stormwater management BMP's, and preliminary location of stormwater treatment and retention/detention facilities for the proposed development. BMP's will include covering soil stock piles and protecting down slope properties with silt fencing. The existing concrete driveway will act as the access to the site with a construction entrance located at the southern end. Grading will be extensive throughout the site. The storm water discharges to an exempt body of water with no opportunity for infiltration on site except for perforated stub out connections for each home. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 1-3.1.3 Step 3 - Perform Off-site Analysis (at Local Agency's Option): Use additional Sheets, if necessary, Ecology recommends that local governments require an off-site analysis for projects that add 5,000 SF or more of new hard surfaces, or convert 3/4 acres of vegetation to lawn or landscape areas, or convert 2.5 acres of forested area to pasture. Off-site analysis extends to mile downstream of the project site. This site discharges to an existing drainage system on the South side of Oakes Avenue beginning at a catch basin at the bottom of the existing concrete driveway that flows west in an existing 12" storm pipe for 329 feet before discharging to an open drainage ditch. After 60 feet of open ditch the drainage system is a closed system along Oakes Avenue in 12" cmp storm pipe for 428 feet then an additional 283 feet of 21" cmp pipe and finally 287 feet of 24" cmp pipe for a total of 1,387 feet or 0.26 miles before combining with the upper Clearidge drainage system and discharging to the north. See the "DOWNSTREAM DRAINAGE SURVEY" drawing in Appendix 5. 1-3.1.4 - Determine Applicable Minimum Requirements Establish project size thresholds for the application of Minimum Requirements to new development and redevelopment projects. Figures 2.4,1 (Attached) and 2.4.2 (Attached) provide the same thresholds in a flow chart format. Based on the preliminary layout, determine whether Minimum Requirements#1 through #5 apply to the project; or, whether Minimum Requirements#1 through#9 apply. Please note, that Minimum Requirement#1 through #5 may trigger additional Minimum Requirements, such as Flow Control. The total new impervious area added to this site will be 12,710 square feet and over the 5,000 square foot threshold and triggers minimum requirements 1 through 9. 1-3.1.5 Step 5 - Prepare a Permanent Stormwater Control Plan (Refer to this section of the Ecology Manual for requirements.) A storm water plan is provided in the developed site plan in Appendix 5. The drainage system will be described in minimum requirement#5 below. The options for a perforated stub out and sheet flow dispersion are discussed in Minimum Requirement#5 below. 1-3.1.6 Step 6 - Prepare a Construction Stormwater Pollution Prevention Plan (MR#2— 13 Elements) Refer to Chapter 11-3—Planning for a detailed description of each element. See also attached Tables 4.1.1 (Source Control BMP's by SWPPP Element) and Table 4.2.1 (Runoff Conveyance and Treatment BMP's by SWPPP Element). See attached 13 Elements of a SWPPP, please complete and attached Version Date: October 7, 2019 Previous Version Date: February 20, 2019 1-3.1.7 Step 7 - Complete the stormwater site plan The Stormwater Site Plan encompasses the entire submittal to the Local Agency with drainage review authority. Refer to this section of the Manual for further clarification of each item and what is required. See below: • Project Overview • Existing Conditions Summary • Off-site Analysis Report • Permanent Stormwater Control Plan • Construction Stormwater Pollution Prevention Plan • Special Reports and Studies • Other Permits • Operation and Maintenance Manual • Declaration of Covenant for Privately Maintained Flow Control and Treatment Facilities. (See attached Drainage BMP Maintenance Covenant BMP Agreement) • Declaration of Covenant for Privately Maintained On-site Stormwater BMP's (See attached Drainage BMP Maintenance Covenant BMP Agreement) • Bond Quantities Worksheet, if applicable The project overview has been provided at the beginning of this report along with an existing conditions description. Maps are included in the attachments. 1-3.1.8 Step 8 - Check Compliance with all Applicable Minimum Requirements A Stormwater Site Plan as designed and implemented should specifically fulfill all Minimum Requirements applicable to the project. The Stormwater Site Plan should be reviewed to check that these requirements are satisfied. To take place during review and during and after construction. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 2 (MINIMUM REQUIREMENT#2) • 1-2.5.2 Minimum Requirement#2—Construction Stormwater Pollution Prevention Plan (SWPP) - All projects are required to complete Minimum Requirement 2. - Refer to the 13 Elements of the SWPP (See document below, complete and attach) - See attached Table 4.1.1, Table 4.2.1 and Table - Provide Engineering Calculations as an attachment for Sediment Ponds\Traps, Diversions, Waterways and Runoff/Stormwater Detention Calculations. Table 4.1.1 Source Control BMP's by SWPPP Element Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Element P1 Element P2 Element 013 Preserve EstablishElementP5 Element110 Element PS ElaEnentP11 Element012 Protect Low MAP or Element Beene y�egeoer�ruetarlt Coretruetlon Sltlblite Protect Control M ointein Menegethe kneedClearinaLimlte Access Saga Slopes Polluherrrs f3:NPs Project Development MMP C101: Preserving Natural VegeleFlon t✓ BMP C102:Buffer Zones +✓ ✓ BMP C103:High VldblYty Plestle or Meta ✓ Fence BMP C105: Stab/teed Construction J Entrance!Exit BMP C105:Wheelillkeh +� BHP CIUT;Comtructlan RaodfPalkk g Ana Slebllrodon BMP CVO:Tampore:yand Par rm om �. Seeding BMP C121: Mulching ✓ '✓ BMP C122: Nets vend Bienkets ✓ I BAP C123:Plastic Covering ✓ BLIP C124: Sodding {✓ BYPC125:TapeallingtCampoatle° ✓ BLIP C121:Pafyecrylr ddd for Sall Eroelan Protection BMP C130: Surge e Roughening ✓ '✓ BLIPC131:Gradient Trances ✓ ✓ BMP CliKo Bust Control +✓ 3MP C15d:Melarkde On Hand ✓ ✓ B MP C151;Concrete Handling '✓ BLIP C152: Sawr:utting end Surlselag ✓ Polutlon Prevention BLIP C193:Matarkll Delvary.Storage end ✓ Conteinmerd BLIP C1M Concrete Mahout Area ✓ BLIP Clad:Certried Erosionand ys ,✓ Sediment Control Lead BMP C112:Scheduing ✓ Table 4.2.1 Runoff Conveyance and Treatment BMP's by SWPPP Element Version Date: October 7, 2019 Previous Version Date: February 20, 2019 , .... . . . Baciawiti4 - Eltienenf liB Elerannt413 . 1 Moment it3 Be Ii26rft ff6 Eleroe rd.iY7 i i Bement:10S tlemant#111 install PINAmc,t- 1 611/blitzu Control Ctantrd De- Prc4""drmy BlIPP qc le mar&time - Onatroi Protonl SvcIrrnelit ; Chnimicita : Impact MOW Pates Sioks :Drain Iniels . - PoilortoTO Lfilierlriff :TOP c2Cidir Cwittereeptair Diko a nei amila .01 ri" ' QV1:P Caelt Gr...n9u-tinvill eliattioal v/ . _ 5P.IP 0202:Chaintiel Liam yr' !KIP C20a; %WI-4r Baos Vf .7 . . - iw - I t I EIIMP C21344r Pip Slope Mains VII 1 i . . EirVIP CAN:: Slikumfact)Ithrzilnis. • ,,,, . BMP C:206: Lama Speesdal I , laMP,C207z, Cluck Eiazitt ill EIMP*20ST. Triangular SW DIkeigiptmat4 V Entritteid Chitk Dam) OM PP 02.118:. Quite.Prabec Finn 4, 1811111P C220: Storrn braill In104 Pro I teGI.orr 1. . _ .. --- LIMP C2.11: Brut*Hana. e? V SNIP 023g: Graft'Mbar Berill if ,._ . -...,____. ____.._ .._.,. ,.--..,.. `"--- " — - r§i‘lw cal': SRt Forum it'' . ..,•' BMP C2341 loreoecated Strip 1 V I4MP C236c 1,NottloA i t MA'02,35-1 ifkogitutive Filtreicm 1 1/14,MPSol:Hap:Int Trap if I Ei DI P CNC Tenapartry Setraverkt Fond 61 If' •. LIMP C2811:: CdsitIntircii Storitualei :Giletcleel Tiastinent i, i 1.1...araz._....-.—,--..---—______...., __ _ .. A tiirmr7 airei:Onnelrileilork Statirwatar If i ',Pilirelicin 1 MAP C252 MOT pi Weigiralizeilon irsina 1 i , 1 'CI:1z • • _ 1 i MP 0253:pH CorgrO for High pi-14VAIxg I i i L..... - 1 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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 Above from 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:_Chris Felt Site Address:_4319/4401 Oakes Avenue Prepared By: Dale Herrigstad PE The Stormwater checklist or building permit determined that: ❑ The 13 elements must be addressed ❑ These elements must be addressed for construction activity adding under for construction activity adding 2,000 2,000 sq. ft. of hard surface area. sq. ft. or more of hard surface area. This means that an attached narrative and site plan are required with this document. Under each element, provide the BMP's that will be applicable to your project. Use the attached Tables provided. 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. A high visibility construction fence BMP C103 will be installed at the perimeter of the construction site except if and existing fence already exists or were silt fence is used. BMP will be installed as first step of construction. BMP to be monitored daily and repaired as needed. 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. The construction entrance will be limited to one location at the top of the existing concrete driveway on the north side of the project with BMP C105 or C107 (Construction Entrance.) Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Any dirt or mud that is tracked onto the roadway will be clean immediately. To be installed prior to construction. BMP to be monitored daily and repaired as needed. 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. BMP C233, Silt Fence will also be installed along the west and north downslope perimeter of the construction site. The majority of the site will be disturbed. 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 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. BMP C233, Silt Fence will also be installed along the west and north downslope perimeter of the construction site. To be installed prior to the start of construction. BMP to be monitored daily and repaired as needed. BMP C162 Scheduling. 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 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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. 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 and plastic covering. Install plastic covering per BMP C123 on Soils Stockpiles. BMP to be monitored daily and repaired as needed. Refer to Table 4.1.1 in MR#2. 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). ❑ 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. ❑ BMP combinations are the most effective method of protecting slopes with disturbed soils. Ex: Use both mulching and straw erosion control blankets. The site has an average slope of 9% and slope protection will be installed as need during and after excavation of the house sites with plastic sheeting and/or much depending on the site conditions. 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. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 ❑ 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. Per detail 1-40.20-00 Storm Drain Inlet protection devices will be installed at existing catch basins in the immediate vicinity of the project. To be installed prior to the start of any construction. Nearest CB is at the base of the concrete driveway at Oakes Avenue. BMP to be monitored daily and repaired as needed. 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. No stormwater runoff will be conveyed off site via channels, swales, or streams. 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. ❑ 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. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 ❑ 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. Per BMP C154 a Concrete Washout Area is to be installed onsite to capture contaminated water from concrete washouts. To be installed prior to foundation !concrete installation. BMP to be monitored daily and repaired as needed. Contractor is to provide spill prevention kits for excavation and concrete crews are required on Site. 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. 11 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. ❑ 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 of water quality standards for turbidity. The easiest way to avoid discharging muddy water is through infiltration and preserving vegetation. If dewatering is needed all discharge will be directed to a temp. sed. trap BMP C240 prior to discharge to the city storm drainage system. The sediment trap will be designed for 9,310 sf impervious area off upland impervious area above the existing concrete driveway 0.21 acres where the developed 2 year flow is 0.04 cfs X 2080 sf/cfc flow= 83 sf surface area plan or 9.1'x9.1'square surface pond area minimum. 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 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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. BMP to be monitored daily and repaired as needed and or as required by the City of Anacortes. Weekly reports are required to be submitted to the building department. 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. ❑ 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. ❑ 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: 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. BMP to be monitored daily and repaired as needed and the responsibility of the owner. Project does require a certified CESCL. ELEMENT 13: Protect Low Impact Development BMPS ❑ If implementing any bioretention facilities or rain gardens, refer to the applicable BMP sections of the Manual for requirements. No LID BMPS are proposed. Dale Herrigstad _August 2, 2020_ Applicant Signature Date Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 3 (MINIMUM REQUIREMENT#3) • 1-2.5.3 Minimum Requirement#3—Source Control of Pollution All known, available and reasonable source control BMP's must be applied to all projects. Source control BMP's must be selected, designed, maintained according to the reference Ecology Manual. The intent of source control BMP's is to prevent stormwater from coming in contact with pollutants. They are a cost-effective means of reducing pollutants in stormwater, and, therefore, should be considered in all projects. All Commercial Properties, Industrial Properties, and Multi-Family Properties, Boatyards, Sand and Gravel Mining Operations are required to comply with this Minimum Requirement. Refer to Chapter IV-2.1 Applicable (Mandatory) Operational Source Control BMP's Single family homes are exempt from this requirement. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 4 (MINIMUM REQUIREMENT#4) • Minimum Requirement#4— Preservation of Natural Drainage Systems and Ouffalls Natural drainage patterns shall be maintained and discharges from the project shall occur at the natural location, to maximum extent practicable. The manner by which runoff is discharged from the project site must not cause a significant adverse impact to downstream receiving waters and down gradient properties. All outfalls require energy dissipation. The objective is to preserve and utilize drainage systems to the fullest extent because of the multiple stormwater benefits these systems provide; and to prevent erosion at the downstream of the discharge location. Refer to the reference manual for supplemental guidelines and additional information under this section. Will this project disturb the Natural Drainage System or Outfall of the project Site? NO. If yes, refer to section 1.2.5.4 for Supplemental Guidelines for additional information. No change in natural drainage from this site is proposed. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 5(MINIMUM REQUIREMENT#5) • Minimum Requirement#5—On-site Stormwater Management Project thresholds that trigger Minimum Requirements#1 through#5, shall utilize the On-site Stormwater Management BMP's from List#1 for all surfaces within each type of surface in List#1; or, Demonstrate compliance with the LID Performance Standard. Projects selecting this option cannot use Rain Gardens. They may choose to use Bioretention BMP's as described in Chapter V-7— Infiltration and Bioretention Treatment Facilities to achieve the LID Performance Standard. Refer to this section of the reference Manual for all Feasibility or Infeasibility Criteria for List#1 and List#2. Is this project Flow Control Exempt?Yes (See Appendix 1-E: Flow Control-Exempt Surface Water). If yes, provide reasoning from the applicability section of 1-2.5.7 Minimum Requirement#7: Flow Control). If No, then the project triggers Minimum Requirement#7 (1-2.5.7) and possibly Minimum Requirement#8 (1-2.5.8). The flow from this site is an enclosed drainage system to Fidalgo Bay and a flow control exempt body of water. If the project is Flow Control Exempt, select from the list below (Skip List 1 and List 2). o BMP T5.13 Post Construction Soils Quality and Depth o BMP T5.10A: Downspout Full Infiltration, or; o BMP T5.10B Downspout Dispersion Systems, or; o BMP T5.10C: Perforated Stub-out Connections, or; o BMP T5.11 Concentrated Flow Dispersion, or; o BMP T5.12 Sheet Flow Dispersion BMP LIST#2 Roofs: (Provide feasible detail and maintenance and operations specifications in the report) 1. BMP T5.30: Full Dispersion Feasiblellnfeasible If infeasible, explain the criteria: Requires native vegetation on site and there is no native vegetation on this site. Or, T5.10A: Downspout Full Infiltration Feasiblellnfeasible If infeasible, explain the criteria: Minimum setbacks shall be 10 feet from any structure and 3 feet from a property line with 3 feet or more of permeable soils to the seasonal high ground water table. The water table is anticipated at a maximum of 16"to 23" and well above the 36" required for infiltration. Full infiltration is infeasible. 2. BMP T7.30: Bioretention Cells, Swales, and Planter Boxes Feasiblellnfeasible If infeasible, explain the criteria:. 23" is to shallow for Bio-filtration where 36" is required. 3. BMP T5.10B: Downspout Dispersion Systems Feasiblellnfeasible If infeasible, explain the criteria: A downspout dispersion system requires a vegetated flow path of at least 50 feet for splash blocks and 25 feet for trenches to a property line or structure. This project impervious area covers most of the site with no area for dispersion. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 4. BMP T5.10C: Perforated Stub-out Connections Feasiblellnfeasible If infeasible, explain the criteria: Perforated stub outs are feasible for drainage prior to discharging to the storm drainage system. Other Hard Surfaces: (Provide feasible detail and maintenance and operations specifications in the report) 1. BMP T.5.30 Full Dispersion Feasiblellnfeasible If infeasible, explain the criteria: Requires native vegetation on site and there is no native vegetation on this site. 2. BMP T5.15: Permeable Pavements Feasiblellnfeasible If infeasible, explain the criteria: 12" of separation from the bottom of the lowest gravel base course to the peak water table is required. Unsuitable soils have been identified at 16" to 23" and water table" making pervious pavers not feasible. 3. BMP T7.30: Biorention Cells, Swales and Planter Boxes Feasiblellnfeasible If infeasible, explain the criteria: Bioretention Cell with an underdrain will be used for water quality treatment is designed in Minimum Requirement#6. 4. BMP T5.12: Sheet Flow Dispersion Feasible\Infeasible If infeasible, explain the criteria: Sheet flow dispersion system requires a vegetated flow path of at least 50 feet or 25 feet for trenches to a property line or hard surface such as the curb line in this case. This project impervious area covers most of the site with no area for dispersion. Or, BMP T5.11: Concentrated Flow Dispersion Feasiblellnfeasible If infeasible, explain the criteria: Like BMP T5.12 flow path length of 25 feet is required prior to reaching a hard surface such as a curb line or adjoining property lines. This project impervious area covers most of the site with no area for dispersion. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 All sites are required to utilize BMP T5.13— Post Construction Soil Quality and Depth. For each surface, consider the BMP's in the order listed for that type of surface. Use the first BMP that is considered feasible. No other on-site Stormwater Management BMP is necessary for that surface. Feasiblity shall be determined by evaluation against: 1. Design criteria, limitations and infeasiblity criteria identified for each BMP in this manual, and; 2. Competing needs criteria listed in Chapter V-5 —On-site Stormwater Management. Lawn and Landscaped Area: • BMP T5.13: Post-Construction Soil Quality and Depth. (Attach Detail in Report) Refer to this site for requirements and specifications. All projects are required to utilize this BMP. http://www.soilsforsalmon.orq/pdf/Soil BMP Manual.pdf See Appendix 3 for the"Model Soil Management Plan for BMP T5.13" to be submitted with Drainage Report and Application Material. An alternate document acceptable to the City of Anacortes is a Test Report provided by the Soils Supplier that identifies the soils to be used meet the specifications outlined under Minimum Requirement 5. The specifications are in both WSDOT and CSI Formats. For specifications, refer to the above referenced PDF. This submittal can be a deferred submittal since most projects are not sure who the supplier will be at the time of building permit application. For projects that trigger Minimum Requirements 1 through 5, the Test Report will be provided to the Building Department. Projects triggering Minimum Requirements 1 through 9, the Test Report will be provided to the Engineering Department. Dale Herrigstad _ 7-31-2020 Applicant Signature Date Version Date: October 7, 2019 Previous Version Date: February 20, 2019 BMP T5.13: Post-Construction Soil Quality and Depth Purpose and Definition Naturally occurring(undisturbed)soil and vegetation provide important stormwater func- tions including:water infiltration; nutrient,sediment,and pollutant adsorption;sediment and pollutant biofiltration;water interflow storage and transmission; and pollutant decom- position.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 quality and depth regains greater stormwater functions in the post devel- opment landscape, provides increased treatment of pollutants and sediments that result from development and habitation, and minimizes the need for some landscaping chem- icals,thus reducing pollution through prevention. Applications and Limitations Establishing a minimum soil quality and depth is not the same as preservation of nat- urally occurring soil and vegetation. 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,com- posted 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. This BMP can be considered infeasible on till soil slopes greater than 33 percent. Design Guidelines ▪ Soil retention. Retain, in an undisturbed state,the duff layer and native topsoil to the maximum extent practicable. In any areas requiring grading remove and stock- pile 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 struc- tural fill or slope shall,at project completion,demonstrate the following: 1. A topsoil layer with a minimum organic matter content of 10% dry weight in planting beds,and 5%organic matter content in turf areas, and a pH from 6.0 2014 Stoirnwater Management Manual for Western Washington Volume V-Chapter 5-Page 911 Version Date: October 7, 2019. Previous Version Date: February 20, 2019 to 8.0 or matching the pH of the 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. 2. Mulch planting beds with 2 inches of organic material 3. Use compost and other materials that meet these organic content require- ments: a. The organic content for"pre-approved"amendment rates can be met only using compost meeting the compost specification for BMP T7.30: Bioretention Cells, Swales,and Planter Boxes(p.959),with the excep- tion that the compost may have up to 35% biosolids or manure. The compost must also have an organic matter content of 40%to 65%, and a carbon to nitrogen ratio below 25:1 . The carbon to nitrogen ratio may be as high as 35:1 for plantings com- posed entirely of plants native to the Puget Sound Lowlands region. b. Calculated amendment rates may be met through use of composted material meeting (a.)above; or other organic materials amended to meet the carbon to nitrogen ratio requirements,and not exceeding the contaminant limits identified in Table 220-B,Testing Parameters,in WAG 173-350-220. The resulting soil should be conducive to the type of vegetation to be established. • Implementation Options:The soil quality design guidelines listed above can he met by using one of the methods listed below: 1. Leave undisturbed native vegetation and soil, and protect from compaction during construction. 2. Amend existing site topsoil or subsoil either at default"pre-approved"rates, or at custom calculated rates based on tests of the soil and amendment. 3. Stockpile existing topsoil during grading,and replace it prior to planting. Stockpiled topsoil must also be amended if needed to meet the organic mat- ter or depth requirements,either at a default"pre-approved"rate or at a cus- tom calculated rate. 4. Import topsoil mix of sufficient organic content and depth to meet the require- ments. 2014 Stormwater Management Manual for Western Washington Volume V- Chapter 5-Page 912 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 More than one method may be used on different portions of the same site. Soil that already meets the depth and organic matter quality standards,and is not com- pacted, does not need to be amended, Planning/Permitting/Inspection/Verification Guidelines & Procedures Local governments are encouraged to adopt guidelines and procedures similar to those recommended in Guidelines and Resources For Implementing Soil Quality and Depth BMP T5.13 in WDGE Stormwater Management Manual for Western Washington. This document is available at: http://www.soilsforsalmon.orglpdf/Soil BMP Manual.pdf Maintenance • Establish soil quality and depth toward the end of construction and once estab- lished, protect from compaction,such as from large machinery use, and from erosion. • Plant vegetation and mulch the amended soil area after installation. . Leave plant debris or its equivalent on the soil surface to replenish organic matter. • Reduce and adjust,where possible,the use of irrigation,fertilizers, herbicides and pesticides, rather than continuing to implement formerly established practices. Runoff Model Representation Areas meeting the design guidelines may be entered into approved runoff models as "Pasture"rather than"Lawn." Flow reduction credits can be taken in runoff modeling when BMP T5.13. Post-Con- struction Soil Quality and Depth is used as part of a dispersion design under the con- ditions described in: • BMP T5.1 OB: Downspout Dispersion Systems(p.905) . BMP T5.11: Concentrated Flow Dispersion (p.905) • BMP T5.12: Sheet Flow Dispersion (p.908) • BMP T5.18: Reverse Slope Sidewalks(p.937) . BMP T5.30: Full Dispersion (p.939)(for public road projects) 2014 5tonnwater Management Manual for Western Washington Volume V-Chapter 5-Page 913 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Figure V-5.3.3 Planting bed Cross-Section Mulch � �-i > 811 Loose soil with visible dark organic matter y Loose or fractured subsoil Reprinted from Guidelines and Resources For Implementing Soil Quality and Depth BMP T5.93 in WDOE 5tormwater Management Manual for Western NET TO SCALE Washington,2010,Washington Organic Recycling Council Figure V-5.3.3 Planting Bed Cross-Section DEPARTMENT OF Revised January 2016 ECOLOGY Please see htfp://www.ecy.wa.goy/copyright.html for copyright notice including permissions, state of Washington limitation of liability,and disclaimer. 2014 Stoimwater Management Manual for Western Washington Volume V- Chapter 5 - Page 914 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 I11-3.1.3 Perforated Stub Out Connections (BMP T5.10C) A perforated stub out connection is a length of perforated pipe within a gravel filled trench that is placed between roof downspouts and a stub out to the local drainage sys- tem. Figure III-3.1.8 Perforated Stub-Out Connection (p.466)illustrates a perforated stub out connection.These systems are intended to provide some infiltration during drier months. During the wet winter months,they may provide little or no flow control. Applications & Limitations Perforated stub-outs are not appropriate when seasonal water table is less than one foot below trench bottom. In projects subject to 1-2.5.5 Minimum Requirement#5: On-site Stormwater Management (p.55), perforated stub-out connections may be used only when all other higher priority on-site stormwater management BMPs are not feasible, per the criteria for each of those BMPs. Select the location of the connection to allow a maximum amount of runoff to infiltrate into the ground (ideally a dry,relatively well drained, location). To facilitate maintenance, do not locate the perforated pipe portion of the system under impervious or heavily com- pacted (e.g.,driveways and parking areas)surfaces. Use the same setbacks as for infilt- ration trenches in 111-3.1.1 Downspout Full Infiltration Systems(BMP T5.10A) (p.452). Have a licensed geologist, hydrogeologist, or engineering geologist evaluate potential runoff discharges towards landslide hazard areas. Do not place the perforated portion of the pipe on or above slopes greater than 20% or above erosion hazard areas without evaluation by a professional engineer with geotechnical expertise or qualified geologist and jurisdiction approval. For sites with septic systems,the perforated portion of the pipe must be downgradient of the drainfield primary and reserve areas. This requirement can be waived if site topo- graphy will clearly prohibit flows from intersecting the drainfield or where site conditions (soil permeability, distance between systems, etc.)indicate that this is unnecessary. Design Criteria Perforated stub out connections consist of at least 10 feet of perforated pipe per 5,000 square feet of roof area laid in a level,2 foot wide trench backfilled with washed drain rock. Extend the drain rock to a depth of at least 8 inches below the bottom of the pipe and cover the pipe. Lay the pipe level and cover the rock trench with filter fabric and 6 inches of fill (see Figure III-3.1.8 Perforated Stub-Out Connection (p.466)). Runoff Model Representation Any flow reduction is variable and unpredictable. No computer modeling techniques are allowed that would predict any reduction in flow rates and volumes from the connected 2014 stormwater Management Manual for Western Washington Volume Ill-Chapter 3-Page 465 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 area Fic rare III-30'08 Perforated Stub-Out Connection random fill G' -.6',.,i ","IN,TA ::f•.fi••-ry!;;: filtpr fabric ��t- .r�l 3 4rZiri "pert'pipe 18"min. `.+.:fr•.,;. 4�+, ; ic orsiritt&fith.' ""-'r'�Tirr "� 11 "y! 1%"-Y.,"washed rock ..;11f►�".s� Ain .. i • 24"min. Trench X-Section slope to road drainage system r- 2'x 10' level trench wlperf pipe Plan View of Roof NOT TO SCALE ibleillaill 14Will Perforated Stub-Out Connection Revised December 2015 DEPARTMENT OF ECOLOGY Please see hap://www.ecy.wa.govicopyright.htrai for copyright notice including permissions, State of Washington limitation of liability.and disclaimer. 2014 Storrnwater Management Manual for Western Washington Volume Ill- Chapter 3 - Page 466 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 6—(MINUMUM REQUIREMENT 6 - RUNOFF TREATMENT) Refer to 1.2.5.6 and provide the required information for this Minimum Requirement. Threshold requirements for determining the applicability of runoff treatment. Projects in which the total of pollution-generating hard surface (PGHS) is 5,000 square feet or more in a threshold discharge area of the project, or Projects in which the total of pollution-generative pervious surfaces (PGPS)-not including permeable pavements-is three-quarters (3/4) of an acre or more in a threshold discharge area, and from which there will be a surface discharge in a natural or man-made conveyance system from the site. This project will split the 3,050 square feet of concrete driveway with 1,767 square feet from Lot 1 to discharge to the eastern basin drainage and 1,278 square feet of driveway combined with the existing 3,400 square feet of common concrete driveway for a total of 4,678 square feet(0.11 acres) and below the 6,000 square feet requiring runoff treatment. Treatment is not required. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 7—(MINUMUM REQUIREMENT 7—FLOW CONTROL) Refer to 1.2.5.7 and provide the required information for this Minimum Requirement. Threshold requirements for determining the applicability of flow control. • Projects in which the total of effective impervious surfaces is 10,000 square feet or more in a threshold discharge area,or • Projects that convert 3/4 acres or more of vegetation to lawn or landscape, or convert 2.5 acres or more of native vegetation to pasture in a threshold dis-charge area,and from which there is a surface discharge in a natural or man-made conveyance system from the site, or • Projects that through a combination of effective hard surfaces and converted vegetation areas cause a 0.10 cubic feet per second increase in the 100-year flow frequency from a threshold discharge area as estimated using the Western Washington Hydrology Model or other approved model and one-hour time steps (or a 0.15 cfs increase using 15-minute time steps). The total proposed new or replaced impervious hard surfaces is split with Lot 1 from Lot 2 to separate drainage basin that follow separate drainage system to Guemes Channel. Each of the drainage routes to Guemes Channel exceed 1,600 lineal feet, with Lot 1 downstream drainage system of 2,765 lineal feet and Lot 2 at 2,643 lineal feet. Lot 1 is 3,410 square feet of roof, 1,767 square feet of new driveway for a total of 5,177 square feet of impervious area and less than the 10,000 square feet threshold discharge area. Lot 1 is 13,923 squared feet(0.32 acres). The site condition previous to this proposal was pasture grass and some brush with no trees. Lot 2 is 2,590 square feet of roof, 1,278 square feet of new driveway and 3,400 square feet of existing driveway for a total of 7,268 square feet of newlreplace impervious area and less than the 10,000 square feet threshold discharge area. The total lot area of Lot 2 combined with the driveway is 14,059 square feet(0,32 acres). 3,400 square feet of the area is existing impervious with a concrete driveway currently and a gravel driveway previously. The site also discharges directly to Guemes Channel through enclosed storm piping. The peak 100 year discharge increase is as follows. LOT 1 WWHM2012 PROJECT REPORT Project Name: lot 1 drainage 8-26-2020 Site Name: Felt Short plat Site Address: 4319 Oakes Ave City : Anacortes Report Date: 8/26/2020 Gage : Burlington Data Start : 1948/10/01 Data End : 2009/09/30 Precip Seale: 0.80 Version Date: 2019/09/13 Version : 4 .2.17 PREDEVELOPED LAND USE Name : Basin 1 Pervious Land Use acre C, Lawn, Mod .32 Pervious Total 0.32 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Impervious Land Use acre Impervious Total 0 Basin Total 0 . 32 MITIGATED LAND USE Pervious Land Use acre C, Lawn, Mod . 2 Pervious Total 0 . 2 Impervious Land Use acre ROADS MOD 0 . 04 ROOF TOPS FLAT 0 . 08 Impervious Total 0 . 12 Basin Total 0 . 32 ANALYSIS RESULTS Stream Protection Duration Predeveloped Landuse Totals for POC #1 Total Pervious Area: 0 . 32 Total Impervious Area: 0 Mitigated Landuse Totals for POC #1 Total Pervious Area : 0 . 2 Total Impervious Area: 0 . 12 Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow (cfs) 2 year 0 . 013886 • 5 year 0 . 029754 10 year 0 . 044315 25 year 0 . 06777 50 year 0 . 08917 100 year 0 . 114135 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow (cfs) 2 year 0 . 047774 5 year 0 . 072142 10 year 0 . 091533 25 year 0 . 120084 50 year 0 . 144525 100 year 0 . 171881 Lot 1 Peak 100 year flow increase from the pre-developed flow is 0.06 cfs and less than the 0.1 cfs threshold. LOT 2 WWHM2012 PROJECT REPORT Project Name : default [7] Site Name : Felt Short plat Site Address : 4319 Oakes Ave City : Anacortes Report Date: 8/26/2020 Gage : Burlington Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale : 0 . 80 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Version Date: 2019/09/13 Version : 4 . 2 . 17 PREDEVELOPED LAND USE Name : Basin 1 Pervious Land Use acre C, Lawn, Mod . 24 Pervious Total 0 . 24 Impervious Land Use acre ROADS MOD 0 . 08 Impervious Total 0 . 08 Basin Total 0 . 32 MITIGATED LAND USE Pervious Land Use acre C, Lawn, Mod . 15 Pervious Total 0 . 15 Impervious Land Use acre ROADS MOD 0 . 11 ROOF TOPS FLAT 0 . 06 Impervious Total 0 . 17 Basin Total 0 . 32 ANALYSIS RESULTS Stream Protection Duration Predeveloped Landuse Totals for POC #1 Total Pervious Area: 0 . 24 Total Impervious Area : 0 . 08 Mitigated Landuse Totals for POC #1 Total Pervious Area: 0 . 15 Total Impervious Area : 0 . 17 Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow (cfs) 2 year 0 . 040814 5 year 0 . 063931 10 year 0 . 082445 25 year 0 . 109799 50 year 0 . 133258 100 year 0 . 159534 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow (cfs) 2 year 0 . 067258 5 year 0 . 098556 10 year 0. 122382 25 year 0 . 156192 50 year 0 . 184186 100 year 0 . 214684 Lot 2 Peak 100 year flow increase from the pre-developed flow is 0.06 cfs and less than the 0.1 cfs threshold. Detention is not required. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 8—(MINUMUM REQUIREMENT 8—WETLAND PROTECTION) Refer to 1.2.5.8 and provide the required information for this Minimum Requirement. There are no wetlands down stream of this site before discharge to the Guemes Channel. TAB 9 — (MINUMUM REQUIREMENT 9 —OPERATION AND MAINTENANCE) Refer to 1.2.5.9 and provide the required information for this Minimum Requirement. The maintenance requires for the Bioretention Cell or as follow: Version Date: October 7, 2019 Previous Version Date: February 20, 2019 FELT OAKES AVENUE BOUNDARY LINE ADJUSTMENT AUDITORS CERTIFICATE IN THE S.E. 1/4, SEC. 22, TWP 35 N., RNG 1 E., W.M. RECORD OF SURVEY AT THE REQUEST:LLF DALE K. HERRIGSTAD CITY OF ANACORTES, WASHINGTON IU _ , a cr2o9c 4 '4, Sing.,Couray Audit. . ' si67,os �a :PBnat7 Pape of• 2tG ,� , ,t} L tt }`,. 5t ,5tt -y` • i 1 `\ \\ f •...F.f •y` ;A�^%-• --'`2.„ _ // rtrt I/+ 1h ty tt tt � -) ti NO LEGAt��IT9Rf81Rt\ 22 \ �. j'.; �• � '"��„�,.�a .`�''l} �t ,15L•�I�.. bt tt tt t ( 0.F`,f +FOUND-•• / HA RS 2597i \ . „ 7'"' D ,, I�f tt t \ yn 00 `�` G R K, 7 \.-s wes4'w \ / '4 `�'`J T R v DEP,I TY ti UDI` OR t t �`,Y r� r Se NS ' 47.72' \\ E v i. Q �Y [� t w t 21 {�i�t,TS J 'O v r7�L/ c+�Q�rC� A yA .le„tt tt� �% / ''�`-moo, t:,1:.5E( REBAR',ANS'VCAP #27807. J r t0- >c x75700'E 5 At / ''`2•') FOii.NO,J.tONtfuENT IN CASE on 4-22-2016. `S. N-7' rVYs i t ' WI/ A tar t P56562 ` / % `'� ,S , .<. 3:f) OUII°q,h'cBAR AND CAP AS NOTED ON 4-22-2016. Ys� t q..0S t 4,, `;,''},.BASiS OF BEARINGS: East boundary of property ROS •Q�,y t t t rota OM • / / y `,. 200$D7220033. / t \ P56563 N r `� �( ~! „.../... y '�; 5,EQUIPMENT USED: CR2 2.TOTAL STATION. r -2 N LOT 1 2991.a .' \r�- ''.,5:'ERROR OF CLOSURE MEETS WASHINGTON STATE SURVEY t tt o 20 1 " t`• ../-- , ; 10 900 SF _ ,..-�y� ' t k - STANDARDS. TRAVERSE r`tr~, tt y t tt tt t ' tt y\ 1 ' "` "f <-• yet o�11 7. SURVEY B. THIS BOUNDARY• STANDARD FIELD SU.T`YNY AND ALL U11LT11 SE WERE NOT r� , + ` ` P3t 8t g p° M VR, I 't t+ t+ �tQi E Fh 11, t �y l� �r ` I u s °v,......,, INNeSTIGATED. �' (1 bag 11 I n 1 r+'"i 9. THIS SURVEY HAS DEPICTED EXISTING OCCUPATIONAL LINES IN I` + tt d J r�� d t + �` I —— ,, �. {w I r ACCORDANCE WITH 'WAC.CH. 332.130. THESE OCCUPATIONAL I V1' t 14�6`� PRELIMINARY PLAT I ""R '' INDICATORS MAY INDICATE A POTENTIAL FOR CLAMS OF UNWRITTEN O t t t ' r Cj OF 49 NORTH I 7 r'Mti<, 'ti "�,..... c t 111 ` t t 1 DCRO‘NuDa` t I �? e,• t�'ty TITLE OWNERSHIP. THE LEGAL RESOLUTION OF SUCH CLAIMS HAS I t tt 1 r tt 1� `t ar E 4 - $4S2t�7'E t 14 I t t a 1•+..,,...-'' NOT BEEN RESOLVED BY THIS BOUNDARY SURVEY. I r tt 4C,t 1 � `4yg, t 24�s t ROS 200807220033 I � .E 1 t L7 I t I` vg Yr' ,' t t t 41 �,, { tr �/= 7I,t \ t A `•y S 5l 005' .-'•-' Sr; tt t } t ''— ` 1 ♦{feet` 1.` ."- A (I) K I' t tt 1~ t`-<efaC3 ---"1-�� `' t 9 tt L©T 2 `t ,, ..... �,'`r'",�L... r,R=",c-,_.•.n^',�'i" I r. i ,'5 , Ri A t 1 t _ `t tt 24,$34 SF tt tt ',,.,,c E'' e I..a'' lib I,t--'a'SE� t x o06 t , , , -• f, •,; I ''3. b GENERAL INFORMATION C t ,N. I ,:,1..„,,--� t 1 t.' S A>tl`tr v t PARCEL B t a 'II., ,� 1' 1. This Boundary Line Adjustment is for the purpose of ctsJ } �'' tt�8 tt F°1 ^ y�y t \ tt \ tt t0 18 4 1 identifying 2 building tweets from 11 city lots in Blocks 1906 <ti .aT� y'` & 1907 of the plat of "BARING ADDITION TO ANACORTES. g?�� t y- t t ttM w i`12299 c. tt ttt 1--_' 44` r WASHINGTON'. I "R' k, t t -L�/ t r , I 4 2. Assessors Account No. P56562. 3774-9D5-007-0009. I t \ r tt N.n ( t '"a ' �,A. 3. Lend Description information is from the Land Title do tJO -' — �' Escrow Company. O 11 ‘t.t t u01t!Tar tt \t t E 4•r rt� 2015. order No: 149766-OA dated June 15, I t t tt t ttt t t „--- ` . ,. `st6-,,,,,,,, 4. Zoning: (R2) Residential Low Density. t` t '+ t t e S• A` 'Y / 5. Water Supply: City of Anoeortes. N I t t t s 74. 5v v 5�' S•r--\ �`'` 's5 _ S. Sewer Disposal: City of Anacortes N I + .` tt Ir•T�• G7 - ��5--- tt �i 4.... s,, '�— '�— 7. Storm Sewer: City of Anocortes. (U tt t _J., Otk4t I i +°• `4x' I 1 6. This is a boundary survey only. Not oil utilities were t -' t�1 t't, t s t ,. ''i i� s r''�{' i 1 Investlgated. O \S It' -i-'•` cJ+r , v^t i,4 ashI`,�- i�. <,�k` :� SFr r�.r 1 SECTION TIE SEE iw. K� 1 o° a......--, �,.t ; '•. i7 ROS aF #2008o7220033 CL iO3 ..ter r y gq,32t,0 � , t L '' 't t ;:T.. !6 1 t P5 57. 'y r4 kF +� �---y l� t t ;.'y :� '� \ PROPERTY AREA BEFORE BLA - A`1 _ t•A t k" r 1 t „t r s MOH CX1RtER />, NIt.C• -yf-t',1�W1 t‘., t „?‘ e. t !? t IV REHM le I % 35,734 SF (0.82 ACRES) ii /I —1 U tt t tt �;r_SxI::y t ':r. ✓ :,t tt 19O �—. OP ASO MST tt t N. (aG.,. �` `°-.• _--"� tt t -s ressr•v o — ADDRESSES: PLAT OF CLEARIDGE DIV II t C t , =,, t e004 I LOT 1 4317 OAKES AVENUE t 04 t 3 fp- r3F #8'0,22C0.3 t E t \°' t x }-ee-"g1 P82597 P LOT 2 4319 OAKES AVENUE 22 s O ` ��+ t .‘',t _.s'- �-' I REVISED FROM EXISTING x r' ' . ../,'` ", M t HOUSE ADDRESS OF CD - '� - 4403 OAKES AVENUE Q. .�r .. b' '''`:. �" SECTION 22, TOWNSHIP 35 N., 4 ` ✓' GRAPHIC SCALE RNG. T EAST. W.M. (1) k< PROPERTY OWNERS N.f xv. Sd: D Z5 50 OD CITY OF ANACORTES, < Chris & Cheryl FeSt SKAGIT COUNTY, WASHINGTON. = � :%„. t°4. % r , "�^ 16839 Korb Road ,. 4-,s, •-.0` (DT Mr) Mount Vernon, WA 98273 BLA-2016-1009 I 1....h.. SO ft. ''; SURVEYOR'S CERTIFICATE BOUNDARY UNE ADJUSTMENT HERRIGSTAD �/ � ,•.• + �+ ti �'rLRRf e • THIS MAP CORRECTLY REPRESENTS A SURVEY MADE BY ME OR UNDER FOR X S6RVEY.. `7' '1:44 -' £ t MY DIRECTION IN CONFORMANCE waH THE REQUIREMENTS OF THE At pALX K. iERRIGSTAD PLS. t !;,� - :7' SURVEY RECORDING ACT AT THE REQUEST OF CHR9S FELT N JUNE ENGINEERING AND SURVEYING CHRIS FELT 43220 WHISTLE LAKE ROAD I 'E v I)f 2Q16. Z ANACORTES WA 98221 11 4,41,.... ^ 4320 tYH1STLE LAKE ROAD, ANACORTES WA SCALE DATE: JOB No: \�" %. ,,,,n DALE K. HERRIGSTAD. P.L.S. .w"' 3 L ( Noted Nov. 201 ti 2015-82 W -•- "360-299-8804 • 4.4. �� ceri!;cote N . z71i07 PHONE (36i)) 299-8804 a j-gyp 2vt) s Date •1 AA1 Liftik.Y ?.a9 ZC/J't DRAWN BY: CHID) BY: SHEET: OF: DALE H. DKH 1 2 Q 1 APPENDIX 2- Soils Analysis (Volume 1, Chapter 3.1.1) Soils Report Linda Spicher, Septic System Designer (360)708-3004 Project/Client: Chris Felt Page / of// Cascade Building Designs, Inc. 16839 Kamb Road Mount Vernon, WA 98273 re ! Site Address: 4319 Oakes Ave., Anacortes, WA 98221 „' ` , . • Parcel Number: 133694 , " ‘°t,+'14 P-. = Date on Site: 12/17/17 ` G � � s�eHat �;.! n0E5lGNE!► !!, Map Unit, Natural Resources Conservation Service: EXPIRES 09.29-;� #30 - Clallam gravelly loam, 8 to 15% slopes This area has been altered by logging, and by back-blading to smooth the soil surface. Soil Log 3 likely represents an area of historic fill,with the brown silt loam horizon,found at 24", the original surface soil. The vegetation of the area is mostly field grass and blackberries. Soil Type' Loading Rate2 Soil Log 1 0—6 brown silt loam 5 0.4 6— 16 brown fine sandy silt loam 5 0.4 16—21 red medium sandy loamy clay 7 not suitable • 21+ gray ashy clay 7 not suitable anticipated water table at 16" observed water table at 21" Soil Lop 2 0—7 brown silt loam 5 0.4 7—23 brown medium sandy silt loam, roots 5 0.4 23—25 gray ashy clay 7 not suitable anticipated water table at 23" observed water table at 23" One of seven numerical classifications of fine earth particles and rock fragments as described in WAC 247-272A-0220(2)(e). 2 From Chapter 247-272A WAC: "Hydraulic Loading Rate"means the amount of effluent applied to a given treatment step,in this chapter expressed as gallons per square foot per day(gal/sq.ft./day). Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Chris Felt, Page Z. of// Soil Loci 3 0—4 brown silt loam 5 0.4 4—24 clay loam, mottles, roots 6 0.2 24—50 brown silt loam, fine roots 5 0.4 50—60 fine sandy ashy clay, mottles 7 not suitable anticipated water table at 50" observed water table at 59" Soil Log 4 0—9 brown medium sandy silt loam 5 0.4 9— 19+ tan clay loam, roots to 17", mottles 6 0.2 anticipated water table at 17" observed water table at 19" A y, 1• . x • ` f" �`I%•f Ot15PICHER op 1�*a� ..DDESIGNER �V* EXPIRES 09.l9 4 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 P130302 P131821 P 130302 PS30304 P131820 P31878 P58421 P131798 Pi3i819 'e P131798 " P131817 P1318ppqq P31680 ' P316,9 P131801 P131799 P13S875 Pt31819 ` ; P31669 P131801 P13t8Q0 Pio18t.4 t f 10.7754 P131389 ' p131388 P131818 p131818 f1', r P131390 P131888 P731874 P31585 ` t: ') P.53426 P1,.1391 1313 D 0131889 P131876 P131876 f•, P131393 P131391 l"3 P131810 pr31881p731877 P31586 t( y) P131's93 P131392 t't'' Pt31809 P131869 P131877' P31584 P113445 P111393 RS31838. PS3S866 P131887 P]31878 : P315..6 • 058428 Pi28091 P13180+fP31583P31682 P128091 P131812 P131885 P131878 P128121 P128092 P73180213t 0131803 Pi31814 . Pi318i5 P1318T9 a P13396U P3P1 3 • :') P128093 ?131802 P/311305 P131815' P131834 P13187 P1336G2 R728093 P13140?, P131606 P130993P130999 P131880. >. Pt33690 P133681 P58435 P128097 P131402 P13t807 P130G1G P13S$8+1 R P133669 P13365'1 P133663 1-;) P1280'.•4 P128097 P131401 131682 Rif3663 f'12809Fi . P130603 P131000 0131 '3 P131881 P133689 C133859 P128995 P130604 Pid0604. P130616 P131 01 P1316432. P133664 P133664 P128099 nr, P130n14 p13368t3 P1'3688 4 P56140 Pi31334 P131394 R1280 '.'pl30512 P130614 131001 €'1336 0 P31GG R90595£ P131395 P128099 P128t1g' 131082. P56'i2 133687, P133687 6 ' r• P131400 P12,8116 P128114 P128115 P130.695 P1 6p 33fi8i P13368! P13„s35 P731393 P1°AGO P58�64 F 678 P133656 P131399 F128S1 P134607 P5 5 . P13 1 P133685 P58445 P13139G 528114 R131395 P131399,I28113' P13°88G: Rt336'7 P133366 P131397 r�128SOf �,,.• P.1574 `� 3fiT7 3369? P133667 R133E67 P722 2 P17.297' Y`'' P12811'l P1281%oat d P13k 33 Pt33G8?i P133G5$ tj)R131393 P12814. P128103 P128102,G? Gi3 v7G P1336+. 1 P128110 P1?8 20. PS?812U �L'.t o P133G83 P133668 �� P120130 P128108 P126111 P17t.118 ;Pc° 12239<s 1.4- u75' P133G69 P128109 P138s18 •'°, P82608 P3157 P13.367 P133669 •' sties��t P130810P130610 P12810:45' P82o09 r F12 P122995 P5E57'3P133674 p 33672 P133671 1 �'R,Ok., P130815 P126108 P128105 ,.82608 P56577 1 3387 3W1 P' 3 . e _1' ,� P122996. 133674 3 P131r007 P128106 P128105: P82607 c� P12299ii rq t3 67U � �srrf' f(t P130615. P82E11 P 577 Pf2297 P8 ' P82595 P82 P32S9.1 8/' '�►. o • \� P131422 P1281Q7 ; P82810 P82607 P122997 P8'399 M 00 f th I?10822E•P130646 r 82G12 P82+a06 R82598.P82S G„,�'d259•f P$G593 O N. ,Ti,• �► P131421 f91310Q5i P1306609'P82813 P82.612 P82605 + P8., 82599 P82593 Pi31420 P131004 P82674 P82Gi3 P82605 F.6$79. P82GJ1 P028CU P82598 • P82590 A.0 m ro ''0Y.4 P82602 Pt314F131404 r P ` P82604 .P82602 P82591' P82592 %.-se m } pp P;3t00B"P8261a 8261v • P131405P131403 P82616 P62627 P82603 P82589 P82591 # P131406 :r• P82615 P8262G. P82627 P32603 P82651 P52998 � ^�> P108225 P82G25 P82650 j P82617 Rum P1058113 P82650•P82552: P82538 'r U1 P731r06 P82G17 P82825 P82oe"8 �i P108170 P82618 P82623' P82629 PS05816 P82649 P82649 P82587 P82586 P32372 d P82318 P62623 P82629 P82647 P82648. P1052G0 2P82619 P82622 Ptt2624 P82c30 P82644 P82644 P82647 'P81733 P82585 P108171 kl P105SuD P82619 P82631 P81732 y P82622 P82631 P82Gr ti l P82621 '3 P82843 P8'1731 ' P825'34 P10.6172 P52620 P82632. P82641 F8173+, P82642 P8t727 P31730 P82563 P31684 ` P105281 P82621 P82633 P52640 Pf31726 P81728 P01735 P82583 P33684 `> P82634 P82640 December 18,2017 1"=300' S It Laftend 0 165 330 660 Ft Tax Parcel Numbers Building Only Accounts n Structures j I I 1 1 ? 1 1 f t\ 0 0,05 0,1 0.2 km Dirt Accounts • Tax Parcels - • Trails 1 1 i OateAccurecy Waning:fel GIS rise was aea:M lrrn ara;abto puW:c ords and Senior Chizen Accounts _- o�dstin7 mop sources. Map features f•a:•e been adjure to a:.I1otiv a bast�ft L. County BoundaryRivers and Streams rctys!ra4an,%4 ifo 5•et taro was mrm?cn n tris process.maps from d5orare sources Mobile Home Only Accounts be,socatos?o],epo`seta':Amof co'apticroa!uros.Uopdioaepanzicazoo Sections 20 foal contours a Copripht;3s5 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 '/i'f..--//.r= r' P;K;'9r :e, --. // 0-' NU LWAI. ! • \ r , POUND7 �,,� \ ` 0�, E' 'o ,1�� n �" s o•4s'54' w \ V _1. ?JO \- - ) A*c_1.-‘350: --- ... \ ///". / _ - /' j '✓' N 257'00' E -3. \ /i �,' "'f" %pQ 1Is.29' P56562 il / / / .- 0A4 1 i . \1 77? 3 TOTAL HOUSE t j / P56563 :,11 N s� LOT in 1 1 N298IGAAERAGE �, �l (� --- _ ` =`1 10,900 SF , y !{,z�' i I 1 10 PRIVATE i p I Ob p��. 'y11 s & SD EsrtT �� \ eaa', ti P31601 I 65E,A1 ..�- al \ \\*g PRELIMINARY PLATFENCE j 1,4 r ENCROACHMENT\. ��p4, i 0 OF 48 NORTH �- 1�`�� c , 24.46 '57•—�.., 19 C I �- , I I .. ROS 200807220033 I I )QOO,6 © I w �' \ 1\(1 LOT 2 `, -,` 1 t7. ' k _ ._ , — ` _ NQ °a�©b 11 1�24,834 SF U -. < I VAC°j �- PARCELS �B" 18 P122993 1,1 _...--1 0' STOMA AND t \� 1`�SANITARY SEWER �-'" �j '`ca 1 1 EASEMENT 1 ' 1. ^ 6 Y 1\11 54 20' SHARE DRIVEWAY AND \-. �-o -�` +� U11UiY EASfMEM \ ;\ I _ �.- S74'2f,'55' 1l 1V1Z\-01R, �� •17.74' 7‘‘5 - -- S�t•g6'S9 w F40.6}` it 1 / ` ti I'd- I Xri ,frOt V? .;4,Int ta►II +, m.� U SPICHER c?. 1 ID 4 s • DESIGNAR 1 OM ...7 116.4110111011,111MILIMMILVIL 1 �� @ � i-1/16TH CORNER I SIRES o9-29•/4 JO `_' P5657 �-S O'46'54' W 6�� 20.04' GRAPHIC SCALE pt 5 S ,��,4� u $i 30 0 30 60 120 1 \ 1111 11111111•1111111111111111111.11111111... 1 Mil ( IN FEET ) PLAT OF CLEARIDGE DIV II 1 inch = 60 ft. \ _--- 1 AF 118204220013 t ,t/r 5, f `%2%-gx.ii cz / HERRIGSTAD ENGINEERING & SURVEYING Proposed access & Utilities 4320 WHISTLE LAKE ROAD %;�i'r /r' to Felt Property P56573 ANACORTES, WA 98221 299-8804 -�� (:) Ye" October 5, 2016 l% Version Date: October 7, 2019 Previous Version Date: February 20, 2019 • Soil Map--Skagit County Area,Washington 4319 Oakes Ave. Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 25 Calla gravelly fine sandy loam, 0.4 12.3% 0 to 8 percent slopes 30 Clallam gravelly loam,8 to 15 2.8 87.7% percent slopes Totals for Area of Interest 3.2 100.0% k 47. t SPICNER DESIGNER EXPIRES 09-29-/e, USDA Natural Resources • Web Soil Survey 12/18/2017 argla Conservation Service National Cooperative Soil Survey Page 3 of 3 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Skagit County Area, Washington 25—Catla gravelly fine sandy loam, 0 to 8 percent slopes Map Unit Setting • National map unit symbol: 2hv6 scow • Elevation: SO to 500 feet • Mean annual precipitation: 21 inches • Mean annual air temperature: 48 degrees F SP1C ER V • Frost-free period: 170 to 200 days °DESGNat • Farmland classification: Prime farmland if drained EXPIRES O9-29-/ Map Unit Composition • Catla and similar soils: 95 percent • Minor components: 5 percent • Estimates are based on observations, descriptions, and transects of the mapunit. Description of Catla Setting • Landform: Hillslopes • Parent material: Glacial drift Typical profile • H1 - 0 to 6 inches: gravelly fine sandy loam • H2 - 6 to 11 inches: gravelly fine sandy loam • H3 - 11 to.17 inches: very gravelly loam • H2 - 17 to 60 inches: gravelly fine sandy loam Properties and qualities • Slope: 0 to 8 percent • Depth to restrictive feature: 10 to 20 inches to densic material • Natural drainage class: Moderately well drained • Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately low (0.00 to 0.06 in/hr) • Depth to water table: About 6 to 18 inches • Frequency of flooding: None • Frequency of ponding: None • Available water storage in profile: Very low (about 1.4 inches) Interpretive groups Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6w Hydrologic Soil Group: D o Other vegetative classification: Wet Soils (G002XN102WA) Hydric soil rating: No Minor Components • Coveland Percent of map unit: 5 percent Landform: Depressions 9 Other vegetative classification: Wet Soils (G002XN102WA) ® Hydric soil rating: Yes 0 6 --' 66 s1ctast D DESIGNER .> EXPIRES 09.29 g, Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Skagit County Area, Washington 30—Clallam gravelly loam, 8 to 15 percent slopes Map Unit Setting ti�of vr�51�hF ® National map unit symbol: 2hvd • Elevation: 30 to 500 feet ? C Mean annual precipitation: 23 inches ' SPIC-IER Mean annual air temperature: 48 degrees F DES1CNER Frost-free period: 160 to 200 days oO1R 9-29-ir'' 6 Farmland classification: Farmland of statewide importance Map Unit Composition Clallam and similar soils: 90 percent a Minor components: 10 percent o Estimates are based on observations, descriptions, and transects of the mapunit. Description of Clallam Setting O Landform: Hilislopes a Parent material: Glacial drift Typical profile O H1 - 0 to 11 inches: gravelly ashy loam o M2 - 11 to 27 inches: very gravelly loam M2 - 27 to 60 inches: very gravelly sandy loam Properties and qualities o Slope: 8 to 15 percent a Depth to restrictive feature: More than 80 inc_hes; 20 to 40 inches to densic material O Natural drainage class: Moderately well drained o Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately low (0.00 to 0.06 in/hr) D Depth to water table: About 18 to 36 inches o Frequency of flooding: None • o Frequency of ponding: None c Available water storage in profile: Very low (about 2.6 inches) Interpretive groups • 6 Land capability classification (irrigated): 4e Version Date: October 7, 2019 Previous Version Date: February 20, 2019 o Land capability classification (nonirrigated): 4s Hydrologic Soil Group: C o Other vegetative classification: Limited Depth Soils (G002XN302WA) o Hydric soil rating: No Minor Components Bow Percent of map unit: 5 percent Landform: Terraces o Other vegetative classification: Seasonally Wet Soils (G002XN202WA) Hydric soil rating: Yes Coveiand o Percent of map unit: 5 percent Landform: Depressions Other vegetative classification: Wet Soils (G002XN102WA) a Hydric soil rating: Yes <rf� f A At.o O DESIGNER EXPIRES 09-29-/ Version Date: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX 3— Model Soil Management Plan for BMP T5.13 An alternate document acceptable to the City of Anacortes is a Test Report provided by the Soils Supplier that identifies the soils to be used meet the specifications outlined under Minimum Requirement 5. The specifications are in both WSDOT and CSI Formats. For specifications, refer to the above referenced PDF. This submittal can be a deferred submittal since most projects are not sure who the supplier will be at the time of building permit application. For projects that trigger Minimum Requirements 1 through 5, the Test Report will be provided to the Building Department. Projects triggering Minimum Requirements 1 through 9, the Test Report will be provided to the Engineering Department. DIFFERED SUBMITTAL TO END OF PROJECT Version Date: October 7, 2019 Previous Version Date: February 20, 2019 DEFERRED SUBMITTAL: PROVIDE A TEST REPORT FROM SOILS SUPPLIER TO THE BUILDING DEPT. PROJECT INFORMATION "Model Soil Management Plan for BMP T5.13" age# of pages Complete all information on page 1; only site address and permit number on additional pages. Site Address /Lot No.:_5304 Sterling Drive /Lot #55 Skyline No.3. Permit Type: Permit Number: Permit Holder: Phone: Mailing Address: Contact Person: Phone: Plan Prepared By: ATTACHMENTS REQUIRED (Check off required items that are attached to this plan) Site Plan showing, to scale: Areas of undisturbed native vegetation (no amendment required) New planting beds and turf areas (amendment required) Type of soil improvement proposed for each area Soil test results (required if proposing custom amendment rates) Product test results for proposed amendments AREA # (should match Area # on Site Plan) PLANTING TYPE Turf Undisturbed native vegetation Planting Beds Other: SQUARE FOOTAGE OF THIS AREA: square feet SCARIFICATION inches (depth) of scarification needed to achieve finished total 12" loosened depth. Subsoil will be scarified PRE-APPROVED inches of compost or imported topsoil applied AMENDMENT METHOD: X 3.1 (conversion factor, inches to cubic yards) PRODUCT:_ Topsoil import = cu. yards per 1,000 sq. ft. Amend with compost X ,000s sq.ft. in this area Stockpile and amend = cubic yards of amendment — — —a --+ —* QUANTITY: CU. YDS. ( cu. yds. stockpiled) (needed to cover this area to designated depth) CUSTOM AMENDMENT Attach test results and calculations. Topsoil import inches organic matter or topsoil import PRODUCT: Topsoil & compost lift X 3_1 Amend = cu. yards/ 1,000 sq. ft. Stockpile and amend X ,000s sq.ft. in this area ( cu. yds. stockpiled) = cubic yards of amendment -* — —+ —f —* QUANTITY: CU. YDS. MULCH ,000 sq.ft. PRODUCT: X 6.2 (conversion, to give 2 inch mulch depth) =cubic yards of mulch — —+ —+ --; - > -4 QUANTITY: _ CU. YDS. TOTAL AMENDMENT/TOPSOIL/MULCH FOR ALL AREAS (complete on page 1 only, totaling all areas/pages in this Plan) U Product#1: ❑ Quantity: cu. yds. U Test Results: % organic matter C:N ratio <25:1 (except mulch, or<35:1 for native plants) "stable" (yes/no) U Product#2: ❑ Quantity: cu. yds. ❑ Test Results: % organic matter C:N ratio <25:1 (except mulch, or <35:1 for native plants) "stable" (yes/no) ❑ Product#3: ❑ Quantity: cu. yds. U Test Results: % organic matter C:N ratio <25:1 (except mulch, or<35:1 for native plants) "stable" (yes/no) Date: Inspector: Approved: Revisions Required: Date: Inspector: Approved: Revisions Required: Version Date: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX 4— Determining Construction Site Sediment Damage Potential (Appendix 7— NPDES Phase II Permit) Note: See attached. All projects within the City of Anacortes are required to complete that document under Appendix 4. Western Washington Phase II Stormwater Permit i. APPENDIX 7 - Determining Construction Site Sediment Damage Potential The following rating system allows objective evaluation of a particular development site's potential to discharge sediment. Permittees may use the rating system below or develop alternative process designed to identify site-specific features which indicate that the site must be inspected prior to clearing and construction. Any alternative evaluation process must be documented and provide for equivalent environmental review. Step one is to determine if there is a sediment/erosion sensitive feature downstream of the development site. If there is such a site downstream complete step two, assessment of hydraulic nearness. If there is a sediment/erosion sensitive feature and it is hydraulically near the site then go to step three to determine the construction site sediment transport potential. ii. STEP 1 —Sediment/Erosion Sensitive Feature Identification Sediment/erosion sensitive features are areas subject to significant degradation due to the effect of sediment deposition or erosion. Special protection must be provided to protect them. Sediment/erosion sensitive features include but are not limited to: i. Salmonid bearing fresh water streams and their tributaries or freshwater streams that would be Salmonid bearing if not for anthropogenic barriers; ii. Lakes; iii. Category I, II, and III wetlands; iv. Marine near-shore habitat; v. Sites containing contaminated soils where erosion could cause dispersal of contaminants; and vi. Steep slopes (25% or greater) associated with one of the above features. Identify any sediment/erosion sensitive features, and proceed to step two. If there are none the assessment is complete. iii. STEP 2—Hydraulic Nearness Assessment Sites are hydraulically near a feature if the pollutant load and peak quantity of runoff from the site will not be naturally attenuated before entering the feature. The conditions that render a site hydraulically near to a feature include, but are not limited to, the following: i. The feature or a buffer to protect the feature is within 200 feet downstream of the site. ii. Runoff from the site is tight-lined to the feature or flows to the feature through a channel or ditch. August 1, 2013, Modified January 16, 2015 Appendix 7- Determining Sediment Damage Potential Page 1 of 3 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 A site is not hydraulically near a feature if one of the following takes place to provide attenuation before runoff from the site enters the feature: iv. Sheet flow through a vegetated area with dense ground cover v. Flow through a wetland not included as a sensitive feature vi. Flow through a significant shallow or adverse slope, not in a conveyance channel, between the site and the sensitive feature. Identify any of the sediment/erosion sensitive features from step one that are hydraulically near the site, and proceed to step three. If none of the sediment/erosion sensitive features are hydraulically near the site, the assessment is complete. vii. STEP 3—Construction Site Sediment Transport Potential Using the worksheet below, determine the total points for each development site. Assign points based on the most critical condition that affects 10% or more of the site. If soil testing has been performed on site, the results should be used to determine the predominant soil type on the site. Otherwise, soil information should be obtained from the county soil survey to determine Hydrologic Soil Group (Table of Engineering Index Properties for step 1.D) and Erosion Potential (Table of Water Features for step 1.E) When using the county soil survey, the dominant soil type may be in question, particularly when the site falls on a boundary between two soil types or when one of two soil types may be present on a site. In this case, the soil type resulting in the most points on the rating system will be assumed unless site soil tests indicate that another soil type dominates the site. Use the point score from Step 3 to determine whether the development site has a high potential for sediment transport off of the site. Total Score Transport Rating <100 Low 0100 High A high transport rating indicates a higher risk that the site will generate sediment contaminated runoff. Construction Site Sediment Transport Potential Worksheet A. Existing slope of site (average, weighted by aerial extent): Points 2% or less .. 0 >2-5% 5 >5-10% 15 >10-15% 30 >15% 50 B. Site Area to be cleared and/or graded: <5,000 sq. ft 0 5,000 sq. ft. — 1 acre 30 >1 acres 50 C. Quantity of cut and/or fill on site: <500 cubic yards 0 500—5,000 cubic yards 5 >5,000— 10,000 cubic yards 10 >10,000—20,000 cubic yards 25 >20,000 cubic yards 40 D. Runoff potential of predominant soils (Natural Resources Conservation Service): Hydrologic soil group A 0 Hydrologic soil group B 10 Hydrologic soil group C 20 Hydrologic soil group D 40 E. Erosion Potential of predominant soils (Unified Classification System): GW, GP, SW, SP soils 0 Dual classifications (GW-GM, GP-GM, GW-GC, GP-GC, SW-SM, SW-SC, SP-SM, SP-SC) 10 GM, GC, SM, SC soils 20 ML, CL, MH, CH soils 40 F. Surface or Groundwater entering site identified and intercepted/: Yes 0 No 25 G. Depth of cut or height of fill >10 feet: Yes 25 No 0 H. Clearing and grading will occur in the wet season (October 1 — May 1): Yes 50 No 0 TOTAL POINTS 125 1 If no surface or groundwater enters site, give 0 points. APPENDIX 5— Site Plan with all applicable information (Minimum Size 11x17 at a legible scale) See attached Downstream Drainage survey and See full scale ECS Plan and details. i I APPENDIX 6 — Documented Site Photos (Show all directions of the site, including frontage) ' i ( Insert Photo Here) a Location : 4401 Oakes Avenue Description of the photo : Lot 2 , Looking West Photo taken b : Dale Herri stad , Y g 12- 16 -2019 t ' -$ XT ��•_,, Sr Y "`iti ^" it 1 ' •\� r r , a 7 if I Lot 1 , Looking Southeast. f� Nx ‘\\4° .\ g {asp} *?J :pC y a P''; J �y �`Y..t17,••4e{611 ( J2! • ("p pii i ' k fC4 kiiy., r .{f Jy K•ya I. Y"•;e444 " a \ ‘+i \ ti aA c;< • aw(14)V'4 4%YM`v•t 0 y l - FSJ:hv,av x t h e d, ;1 , t*f '",..e.y ,k ,0'rJ^ X w \ � S1 i Looking up center of existing concrete drive to center of lots . , 'lief 4. 44 ^C;µ .— B •St .; r: ) I Fa ' K6z� ")' %�. yvt red?�... 'n vor , ,,y�� e vi.: �: 0 ♦r v . a,�xx + a2 4 \, f • i r3i` t Ike �. ; 4. le Top of concrete drive looking north to Oakes Avenue at bottom of concrete drive . W !!'vrJ�S 7 c, , j� uV�� lilt aka t\ 44- lYS! r t}.\ n • ;;\\ . ,X x tiffs 3t ! �,) rr I ' niti `� -- <M Yk uu4 :S . 1 1 { t t lt. \ <\1M 4A y�'S' )1/ 1 .. y \ MF \' ! [ 1 Y S' i i a , . " �i 4. am, r� % .ri. �e,�Q " 7 \ r is I \ APPENDIX 7— Drainage BMP Facility Maintenance Covenant Note: To be recorded prior to: 1) Temporary Certificate of Occupancy; 2) Final Certificate of Occupancy, and or; 3) Final Acceptance of the project. This is Covenant is required for any Permanent Stormwater Facility constructed on a project site. The applicant should work with the the City of Anacortes Engineering Department on formalizing the document for recording. No maintenance Covenants required for Perforated Stub Outs.