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HomeMy WebLinkAboutPermit File BLD-2020-0201 2007 Bradley Drive (3) t1ERRiG Y 4P�o�: wnsiii sT90 Mix 'a o ��` Storm Water Drainage Report 1/4) inimum Requirements 1 through 5 27807 ENGINEERING DEPARTMENT � �� �,� %.4s,4)Fcis v004,v 9 ..� 904 6th Street Anacortes, WA 98221 sioNAL 04G www.anacorteswa.gov CO Official Use Only: (Information to Inspectors) Required Storm Water Facility and other related requirements: Project Address: _2007 Bradley Drive Submittal Date: Parcel Number: _P59134 Revision Number: Permit Number: _BLD-2020- Reviewer: Acceptance Date (COA): FRONT OF REPORT: 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 APPENDIX 1 - Survey performed by a Professional Land Surveyor o APPENDIX 2 - Soils Analysis (Volume 1, Chapter 3.1.1) FLOW CONTROL EXEMPT 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 11 x17 — 30 scale) o APPENDIX 6 - Documented Site Photos (North, South, East and West) o APPENDIX 7 - Drainage BMP Facility Maintenance Covenant, if applicable. To be recorded prior to the Temporary Certificate of Occupancy, Certificate of Occupancy or Final Acceptance. FLOW CONTROL EXEMPT Stormwater Management Requirements: 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. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Project Description and Summary: Summary Table Existing Proposed Development Type Undeveloped Single Family Number of Lots 1 Lot Acreage in SF 8,276 SF Soil Type(s) Catla Gravely Fine Sandy Loam HG D _Site Sediment Transport Score (High\Low) _ High 140 High 140 Depth to Ground Water Table (Feet and Inches) N/A Flow Control Exempt (See completed Soils Analysis (Volume 1, Chapter 3.1.1) Infiltration Rate during Rainy Season (Inch\Per Hour) N/A Flow Control Exempt Impervious Surface (on-site) 0 4,944 sf Impervious Surface (off-site) 0 0 New and Replaced Hard Surface Total (SF) 0 4,944 sf Lot Coverage (Percentage) 0 60% 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: P (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 existing 8276 square foot lot is undeveloped with a few trees and grass at a slope of 10 to15% with Bradley Drive at the bottom of the slope. Anaco Beach Road fronts the top of the lot directing offsite storm water away from the site. No offsite water sheets onto this site. No critical areas exist on or near the site. Existing drainage sheets to Bradley Drive with a curb and gutter. The closest enclosed drainage system is located at the intersection of Bradley Drive and Heather Drive approximately 200 feet south of the property. 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 project is to construct a 2,390 square foot single family home, 289 square feet of deck, 173 square feet of entry slab, 1,426 square feet of driveway and 666 square feet of parking for a total new impervious area of 4,944 square feet. The driveway will wrap around the south side of the site to Bradley Drive. The site plan shows existing and proposed contours. Drainage Basin (2007 Storm Comp Plan — City website\publicworks\engineering\comprehensive plans): What Drainage Basin are you in? B10 Identify any downstream drainage issues (Storm Comp Plan: Yes. If so, describe: No issues are identified for basin B10. Complete the Applicability Requirements — Flow Chart (Figure 1-2.4.1 Attached, Figure 1-2.4.2 Attached and Figure 1-2.5.1 Attached) Figure I-2.4.1 Flow Chart for Determining Requirements for New Development Figure 1-2.4.1 Flow Chart for Determining Requirements for New Development Start Here 1 Does the site have 35% Yes See Redevelopment Minimum or more of existing ► Requirements and Flow Chart impervious coverage? (Figure 1-2.4.2). No Does the project convert ' acres or more of vegetation to Does the project result in lawn or landscaped areas,or 5,000 square feet,or No convert 2.5 acres or more of greater;of new plus ► native vegetation to pasture'? replaced hard surface area? \No Yes 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 45 apply to the new , Yes square feet or greater? and replaced hard surfaces and the land disturbed. No ■ Minimum Requ irement#2 applies. saft.:= Figure I-2.4.1 Flow Chart for Determining Requirements for New Development DEPARTMENT OF Re,Ased June 2015 EC O LOGY Please see httpl/www.ecy.wa.gav/capyright.himifor 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 Figure I-2.5.1 Flow Chart for Determining LID MR #5 Requirements Does the project discharge to Flow Control Exempt Waters(per Minimum Requirement(MR)#7)? Yes REQUIRED:Implement the following BMPs No where feasible: • BMP T5.13:Post-Construction Soil Quality ■ No(the and Depth Does the project project ▪ BMP T5.10A,8,or C:Downspout Full trigger only MRs#1- triggered Infihtration,Downspout Dispersion #5?(Per Figure 3.2 or only MR#2) No additional Systems,or Perforated Stub-out Figure 3.3 in Appendix0. Connections 1 of the 2013-2018 requirements . BMP T5.11 or T5.12:Concentrated Flow W1NA Phase II Permit Dispersion or Sheet Flow Dispersion &Phase I Permit). NOT REQUIRED:Achievement of the LID No(the project triggered Performance Standard.Applying the other Yes only MRs#1-#9) BMPs in List#1 or List#2. Is the project inside the UGA? Did the project developer choose to meet No the LID Performance Standard? Yes Is the project on a parcel No of 5 acres or larger? REQUIRED:For each Did the project developer No Yes surface,consider the choose to meet the LID + BMPs in the order Performance Standard? REQUIRED:Meet the LID listed in List#1 for that Performance Standard through type of surface.Use Yes the use of BMP(s)in the the first BMP that is 2014 3W 1MAW except for considered feasible. Yes No Rain Gardens(the use of Bloretention is acceptable). NOT REQUIRED: Achievement of the LID V lithe project can't meet the Performance Standard. REQUIRED:For each LID Performance Standard,it surface,consider the BMPs must seek and be granted an REQUIRED:Meet the LID Performance in the order listed in List#2 exception/variance. Standard through the use of any BMP(s)in for that type of surface.Use the 2014 St iMMWWexcept for Rain Gardens the first BMP that is REQUIRED:Apply BMP T5.13 (the use of bioretenlion is acceptable). considered feasible. Post-Construction Soil Quality and Depth. REQUIRED for Projects Triggering MR#1-9`: NOT REQUIRED: Apply BMP T5.13 Post Construction Soil Achievement of the LID NOT REQUIRED:Applying the Quality and Depth. Performance Standard. BMPs in List#1 or List#2. NOT REQUIRED:Applying the BMPs in List #1 or List#2. *Recommended by Ecology for projects triggering MRs#1-#5. Figure 1-2.5.1 Flow Chart for Determining LID MR #5 Requirements DEPARTMENT OF Retised June 2015 ECOLOGYPlease see hftpi/www.ecy.wa.gaulcopyright.hfmlfor copyright notice including permissions, State of Washington limitation of liability,and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume I- Chapter 2-Page 60 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 10 to 15% down to the Bradley Road frontage. Single family homes lie on either side of this site with Anaco Beach Road bordering the uphill northeast side and Bradley Drive on the bottom southwest border of the site. 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 temporary construction entrance will be off Bradley Drive. Grading will take place across most of the entire site. The site is Flow Control Exempt due to direct discharge to Flounder Bay through continuous enclosed storm drainage system. Treatment is not required due to pollution generating surface areas below thresholds requiring treatment. 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 % 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. Storm water sheets to the southwest to Bradley Drive and into the existing gutter line along the east side of Bradley Drive. Gutters flow to the south 159 feet from the southwest corner of the site to an existing catch basin. Storm water flows in an enclosed storm system to the northwest along Heather Drive 1050 feet and then south 724 feet and discharge to Flounder Bay for a total distance of 1,933 feet (0.37 miles) from the site. There are no know problem areas identified in the City 2007 Storm Water Management Plan. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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 4,944 square feet and under the 5,000 square foot threshold and triggers minimum requirements 1 through 5. 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 site is Flow Control exempt. The report will require Post-Construction soil quality and depth as well as perforated stub out connections before discharging to the curb line. 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 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) Version Date: October 7, 2019 Previous Version Date: February 20, 2019 • 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 Elamarnf}7 ElamarnR Element05 Elements E lament/B ElementR11 Element012 Elamernf}13 BLIP or Element Nome Preserve Establish ProtectProtect Control Maintain Manage the Protect Low 1RagetetbnAMak Conatnjctbn Solo Slopes Pollutants BMPs Project Impact Clemina Limits Access Development BLIP C101: Preserving Natural Vegetation se BLIP C102:Buffer Ions ,/ I BLIP C103:High Vl ibilty Plastic or Metal r r Fence BLIP C105: SmhlixedConatroctlan r Entrance I Exit BLIP C105:Wheel Wash r BLIP C10T:Construction RoodfParkrlg r Area Stakllutlon BLIP C120:Temporary and Pernsnent r if Seeding ®LIP C121: Mulching r if BMP C122: Nets and Blankets I I SHP C123: Piers*Covering V ®HP C124: Sodding V SHP C125: ioptolling/Comportklg V SHP C120: Palymndmide for Soil Eroxlon V Protection SHP C130: Sudan Roughening V V SHP C131:GredleniTerraxn r r ®HP C140: Dust Control r SHP C150: Manrkrle On Hand r r SHP C151:Concrete Handling r SUP C132: Saerautdng and Surfacing r Palution Prevention SLIP C133: LIalerkrl Delver',Storage and r Containment BMP C134:Concrete Mahout area r SUP C100:Ceelled Erosion and r r Sediment Control Lead ®HP C102:Scheduing I Table 4.2.1 Runoff Conveyance and Treatment BMP's by SWPPP Element Version Date: October 7, 2019 Previous Version Date: February 20, 2019 • Elemerd 13 El• 44 Element RCS Element Iq7.• €Itrncrit liftE Barnett 009 Elemank 10 �lertrent R9 4 dP P ce�147rrarrtNare• • CC,rrtroI Sediffeirit a1 •ll PRAM Ph4h4[ ' 51eblllro• Gontrnl Combo!De, rP14Ck LowRIQMrFlatus SJnpnf •drain Inlais {.`harsrrai. Pedlulants WHeterlin Impact {ronlraki end Orr leis ]BYe3uprnen! $4P Gam' wrterortptor DU 4r+d 9ralrt • i ,/ SNP Cat_ Graw,1_erpd C hanaiels V E3A!P C3112;Cherrrtel Union • d 6AIP i 2Oc: Wat r asps I • -EIRIP C2N: Km Slope Drams I I 8L1P C,2Od: Subisurbaa bwiry V EIMP C3Q : Lftwe1 91Preldir I !!MP C i7: Chock Elam i/ €@MP G3011; TriarreuIRr Wit Glhe fligotex116. ✓rr onaed etli tk OldrVQ BMP Orrl1Ek Pn lccI bn V 6MP 30: 911.orrn Drain Wel Proteetlon- I o MPC? 1.. 111,0211 Beeler I I e HP Mt ]rfivol Faker BonnV ' • 9MPC234Viospalleil31rip ,fV , i 12 re C2NIE Vitrttlos , aMP C 'kgItetIve Filtration I I3MP'dZirt Sr.dfmonE Trap , If ' BmPC2a17 TrmySrarySrdikrtan4Porrl I I i 'BMP CP ' C w 1Ioh SIo.:.�dlat: I ✓ CI1eir J/realm:Ft I ,i E3mP C251:CanBtniellon Etiiini elor - I Fltiraklcra • r . El MP C25Z HIcli pH Pleutralkritea Ware IBMPC 53-PilCO^6tdkwHLPrpH154rtar 1 ' ._. 13 Elements of SWPPP Version Date: October 7, 2019 Previous Version Date: February 20, 2019 (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: Michael and Mary Pearia Site Address:_2007 Bradley Drive 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 C233, Silt Fence will also be used to mark the downslope perimeter of the construction site. 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 Bradley Drive with BMP C105 or C107 (Construction Entrance.) Any dirt or mud that is tracked onto the roadway will be clean immediately. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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. A temporary Sediment Trap BMP C240 will be located at the downhill west side of the property and sized as shown in Element 10. 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. P 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. Ip 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. Per BMP C233 a silt fence will be installed along the downslope perimeter of the site along Bradley drive and the neighboring property boundaries. 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. L Control stormwater volume and velocity within the site to minimize soil erosion. ❑ Control stormwater discharges, including both peak flow rates and total stormwater volume, to minimize erosion at outlets and to minimize downstream channel and stream bank erosion. ❑ Soils must not remain exposed and unworked for more than the time periods set forth below to prevent erosion. o During the dry season (May 1 — Sept 30): 7 days o During the wet season (Oct 1 —Apr 30): 2 days Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather forecast. E 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 is slopes from 10 to 15% and will require slope protection. ELEMENT 7: Protect Drain Inlets ❑ Protect all storm drain inlets made operable during construction so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. ❑ Clean or remove and replace inlet protection devices when sediment has filled one-third of the available storage (unless a different standard is specified by the product manufacturer). ❑ Where possible, protect all existing storm drain inlets so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. ❑ Keep all approach roads clean. Do not allow sediment and street wash water to enter storm drains without prior and adequate treatment unless treatment is provided before the storm drain discharges to Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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 just south of the site at the corner of Bradley Drive and Heather drive approximately 150 feet from the southwest corner of the site. 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. ❑ Obtain written approval from Ecology and provide to the City before using chemical treatment other than CO2 or dry ice to adjust pH. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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. ▪ 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 a typical 4,900 sf impervious area or 0.11 acres where the developed 2 year flow is 0.03 cfs X 2080 sf/cfc flow = 62 sf surface area plan or 8'x8' 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. H Provide protection to all BMPs installed for the permanent control of stormwater from sediment and compaction. All BMPs that are to remain in place following completion of construction shall be examined and placed in full operating conditions. If sediment enters the BMPs during construction, it shall be removed and the facility shall be returned to the conditions specified in the construction Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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). LI 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 not requires 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. Applicant Signature Date 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. Single Family Residential Construction Projects and Residential Subdivisions are Exempt from this Minimum Requirement. All Commercial Properties, Industrial Properties, and Multi-Family Properties, Boatyards, Sand and Gravel Mining Opertations are required to comply with this Minimum Requirement. Refer to Chapter IV-2.1 Applicable (Mandatory) Operationsal Source Control BMP's 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 Outfalls 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 drainage is proposed for this site. A perforated stub out connection will be utilized to control runoff. 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 l-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 has a direct discharge to Flounder Bay 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 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.org/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 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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. BMP T5.10C: Perforated Stub-out Connections Roof downspouts will be collect to the northeast corner of the house and pass through the perforated stub-out prior to discharging to Version Date: October 7, 2019 Previous Version Date: February 20, 2019 111-3.1.3 Perforated Stub Out Connections (BMP T5.1OC) 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 111-3.1.8 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 111- Chapter 3-Page 465 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 area. Figure III-3.1.8 Perforated Stub-Out Connection random fill He'::nY ''-' -= •::t'fk:+: 6^ :-t, ' yrnn:�,. . s"c Ff" •.-.--'may filter fabric K�;lfe-Ilteli; 4"pert pipe 15 min. r�fi�Fiel .tea is frail;`� .:fir r+��e fl�r �� 1%"-X"washed rack I- 24"min. Trench X-Section slope to road ~ drainage system 2'x 10'' level trench wlperf pipe Plan View of Roof NOT TO SCALE Ma.= Figure III-3.1 .8 ulUI Perforated Stub-Out Connection DEPARTMENT O F Revised December 2015 ECOLOGY Please see httpi/www.ecy.wa.goulcopyright.htmt for copyright notice including permissions. State of Washington limitation of liability,and disdaimer. 2014 Stormwater Management Manual for Western Washington Volume 111- Chapter 3-Page 466 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 SKYLINE NO . 3 AF # 716497 SECTIONS 27 & 28 , TWP , 35N , R 1E , W . N . ..........:.:.. 27, t L1 �'aka 0 �Avi .: y.. � :'; 7,2 154 99 S1 o.Z } 7,P*� Are fiC15 -P- .- 4 , % -� .Fri �6 5.4r43` 4 b" ape , �-�, -0. , t Vs 1,6.77 , 0 a•- , tell � ' Aq3 Z y 6 �4 Attu i1j t) Y, by _ A Y� : ikP „� Y /1/ V APPENDIX 1 sl` SURVEY 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. 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.:_. 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) L 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 —*—*—*—*—* 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 —+ ——+ QUANTITY: CU.YDS. MULCH ,000 sq.ft. PRODUCT: X 6.2 (conversion, to give 2 inch mulch depth) =cubic yards of mulch —p—p—p—p—p— QUANTITY: CU.YDS. TOTAL AMENDMENT/TOPSOIL/MULCH FOR ALL AREAS(complete on page 1 only, totaling all areas/pages in this Plan) ❑ Product#1: ❑Quantity: cu.yds. ❑ Test Results: %organic matter C:N ratio<25:1 (except mulch,or<35:1 for native plants) "stable"(yes/no) ❑ 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. ❑ 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 100 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 intercepted1: 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 140 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 SITE PLAN APPENDIX 6 — Documented Site Photos (Show all directions of the site, including frontage) (Insert Photo Here) Location: 2007 Bradley Drive Description of the photo: From Bradley looking East. Photo taken by: Dale Herrigstad April 28, 2020. . � e' � r .� : a ° V `'.t'M '• ' 1 4., r - bf . %., aF d ,1 • -a D. a. r , i•,i .. r ' yaa-" r as M 1 �. - a f _ r ;y ♦ `js 1 R + • - 4 MP `yh d !h j �.ij ,^ .!i0t sJ_ a l / � , ya k* ' . t 1 y am' +t' '. # 7 3 "IT f - i, • Al ,I� 1- _ 15 �p •,1 ` I7Yt ' C..r ram. t,, � .. d •. , 11 r '•4 , '," ' a.„, =` r�'� ` . , ` `g er • ar, 41 aw . Y , r, ' ' y ' 4� V r * 1� f +i � 1 + 1, R01/4 ti '.1 ' '$ ""� ' _— T s ;s 11, �"' att ,ti's, ,6 `t4 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. Not needed for Perforated Stubout. Figure 11-4.1.1 Stabilized Construction Entrance NOT TO SCALE sO rk to.aiPt-l.� ,cam, 0/Ow • AP OP AP . 100'min. Install driveway �, AP • cA cI AP culvert if there is a �u : ,• ^• ^• ^• ^. �i'- .0.2, roadside ditch present ���� 4"-8"quarry . spalls ��.�c�� • r � � • �L�cI cI �I �I cI Geotextile Notes: 15'min. 1. Driveway shall meet the requirements of the 12"minimum thickness permitting agency. 2. It is recommended that Provide full width the entrance be of ingress/egress crowned so that runoff area drains off the pad. ftNiMPiM Figure 11-4.1 .1 Stabilized Construction Entrance DEPARTMENT OF Revised June 2015 E CO LOGY Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, State of Washington limitation of liability,and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume II- Chapter 4 -Page 273 BMP C107: Construction Road/Parking Area Stabilization Purpose Stabilizing subdivision roads, parking areas, and other on-site vehicle transportation routes immediately after grading reduces erosion caused by construction traffic or runoff. Conditions of Use Roads or parking areas shall be stabilized wherever they are constructed, whether permanent or temporary, for use by construction traffic. • High Visibility Fencing (see BMP C103) shall be installed, if necessary, to limit the access of vehicles to only those roads and parking areas that are stabilized. Design and • On areas that will receive asphalt as part of the project, install the first Installation lift as soon as possible. Specifications •A 6-inch depth of 2- to 4-inch crushed rock, gravel base, or crushed surfacing base course shall be applied immediately after grading or utility installation. A 4-inch course of asphalt treated base (ATB) may also be used, or the road/parking area may be paved. It may also be possible to use cement or calcium chloride for soil stabilization. If cement or cement kiln dust is used for roadbase stabilization, pH monitoring and BMPs (BMPs C252 and C253) are necessary to evaluate and minimize the effects on stormwater. If the area will not be used for permanent roads, parking areas, or structures, a 6-inch depth of hog fuel may also be used, but this is likely to require more maintenance. Whenever possible, construction roads and parking areas shall be placed on a firm, compacted subgrade. • Temporary road gradients shall not exceed 15 percent. Roadways shall be carefully graded to drain. Drainage ditches shall be provided on each side of the roadway in the case of a crowned section, or on one side in the case of a super-elevated section. Drainage ditches shall be directed to a sediment control BMP. • Rather than relying on ditches, it may also be possible to grade the road so that runoff sheet-flows into a heavily vegetated area with a well-developed topsoil. Landscaped areas are not adequate. If this area has at least 50 feet of vegetation that water can flow through, then it is generally preferable to use the vegetation to treat runoff, rather than a sediment pond or trap. The 50 feet shall not include wetlands or their buffers. If runoff is allowed to sheetflow through adjacent vegetated areas, it is vital to design the roadways and parking areas so that no concentrated runoff is created. • Storm drain inlets shall be protected to prevent sediment-laden water entering the storm drain system (see BMP C220). Maintenance Inspect stabilized areas regularly, especially after large storm events. Standards Crushed rock, gravel base, etc., shall be added as required to maintain a stable driving surface and to stabilize any areas that have eroded. Following construction, these areas shall be restored to pre-construction condition or better to prevent future erosion. Perform street cleaning at the end of each day or more often if necessary. Figure II-4.1.7a Concrete Washout Area i 3m Minimum o o 0 o Lath and flagging 99i9 ( ) \ ( ) 0 on 3 sides Y y / /- Sandbag o o Berm Sandbag 10 mil plastic lining Varies OA� o �A o 1m / A A \ `, Berm o \ O O ( 0 0 Section A-A 10 mil plastic lining Plan Notes: 1. Actual layout determined in the field. Type "Below Grade" 2. A concrete washout sign shall be installed within 10 m of the 3m Minimum temporary concrete washout facility. Wood frame B B securely fastened around entire perimeter with two stakes Varies -' 10 mil plastic lining Stake(typ.) o Section B-B 10 mil plastic lining Two-stacked 2x12 rough Plan wood frame Type "Above Grade" with Wood Planks NOT TO SCALE ftNiMFM Figure II-4.1 .7a Concrete Washout Area DEPARTMENT OF Revised June 2015 ECOLOGY Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, State of Washington limitation of liability,and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume II- Chapter 4 -Page 322 Figure II-4.1.7b Concrete Washout Area Straw bale 10 mil plastic lining Binding wire Staples Native material (2 per bale) 11 (optional) Wood or I.1U !■I■ Plywood metal stakes 11■k AIM 1200 mm x 610 mm Wood post bale) bi■ .__ _.: ■1■ (2 per 1 I painted white (89 mm x 89 mm Lag screws x 2.4 m) Section B-B (12.5 mm) e CONCRETEie Black letters WASHOUT I 150 mm height 915 mm I I 1915 mm —f- 3m Minimum Stake(typ) Concrete Washout Sign Detail (or equivalent) El • • . . . . • B B NM MN Varies 1:1 II + ^� 50 mm 200 mm �--- 3.05 mm dia. steel wire Staple Detail Straw bale 10 mil plastic lining Notes: (typ) 1. Actual layout Plan determined in the field. 2. The concrete washout sign shall be installed within 10 m of the temporary concrete washout facility. Type "Above Grade" with Straw Bales NOT TO SCALE ffiiMPiM Figure II-4.1 .7b IIRI Concrete Washout Area DEPARTMENT OF Revised June 2015 ECOLOGYPlease see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, State of Washington limitation of liability,and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume II- Chapter 4 -Page 323 Plan View Back of Sidewalk Burlap Sacks to Catch Basin Overlap onto Curb Curb Inlet Back of Curb) RUNOFF RUNOFF SPILLWAY fi Nor Gravel Filled Sandbags Stacked Tightly NOTES: 1.Place curb type sediment bathers on gently sloping street segments,where water can pond and allow sediment to separate from runoff. 2. Sandbags of either burlap or woven'geotextile'fabric,are filled with gravel,layered and packed tightly. 3.Leave a one sandbag gap in the top row to provide a spillway for overflow. 4.Inspect barriers and remove sediment after each storm event.Sediment and gravel must be removed from the traveled way immediately. Figure 4.2.10—Curb and Gutter Barrier Volume II— Construction Stormwater Pollution Prevention-December 2014 4-87 Figure 11-4.2.12 Silt Fence Joints in filter fabric shall be spliced at posts.Use staples,wire rings or equivalent to attach fabric to posts 2"x2"by 14 Ga.wire or equivalent, if standard strength fabric used i t 'i'i�i'i'i'i'i'i'i'���i'i'i'i�i'i'i'i'i'i'i', iii .• W ►i'i'iI ' pp00�'p�'000�'�OOp000'p�'OOOptIL ►i'i'i4 ' ■ ■.■ ■■ ... 4 , i =i ii : O IR4&E - •i ♦ ,'- �ii ///\1/�j 1 1K\� \\,\\,,,, z\\\\•\\L/\\\\�\\// \ / (\ rr Minimum Y I I 6'max 4"x4"trench I I u Post spacing may be increased to 8'if wire backing is used 2"x2"wood posts,steel fence posts,or equivalent 2"x2"by 14 Ga.wire or equivalent, if standard strength fabric used NI •1 \\ N1 �\\ Filter fabric •I \ \ .. 2'min ii \ \ \ \//\ it \/\\/\\ it Backfill trench with \/%/\ ,,,—411 _ native soil or%"- !:'�l ///�jV/ 1.5"washed gravel ri `" \ „ / \\ \\\ Minimum I ' ' 4"x4"trench 2"x2"wood posts,steel fence posts,or equivalent NOT TO SCALE ftNiMM Figure 11-4.2.12 ulai Silt Fence DEPARTMENT OF Revised October 2014 ECOLOGY Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, State of Washington limitation of liability,and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume II- Chapter 4 -Page 369 Figure 11-4.2.16 Cross Section of Sediment Trap Surface area determined at top of weir 4'Min. 1'Min. Overflow 1'Min. 0y7 1'Min. 3.5'-5' �d+ 1.5'Min. Flat Bottom %4"-1.5" Washed gravel Discharge to Note:Trap may be formed by berm or by Geotextile stabilized partial or complete excavation. 2"-4"Rock ooneeyance, outlet,or level spreader Rip Rap NOT TO SCALE Figure 11-4.2.16 Cross Section of Sediment Trap DEPARTMENT OF Revised November 2015 ECOLOGYPlease see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, State of Washington limitation of liability,and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume II- Chapter 4 -Page 386 Figure 11-4.2.17 Sediment Trap Outlet 6'Min. I in I i III In In III— 1'Min.depthoverflowill III III III III III I I I —III-1 I I—III—III—III—III spillway 1 III I I—I 11—III-1 I I—III—III. I-I I I . ._i. 0_0 • 0 0a1-1 . ._._... I—I 1 I III= Min.1'depth 2"-4"rock IIIIIII III lI —III 11I III IIIIII Native soil or —III—III-1 I III—III-1 11—III-1 I I—I 1 Min. 1'depth 3/4' -1.5" compacted backfill washed gravel Geotextile NOT TO SCALE ffilUPM Figure 11-4.2.17 Sediment Trap Outlet DEPARTMENT OF Revised November 2015 ECO LOGY Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, State of Washington limitation of liability,and disclaimer. 2014 Stormwater Management Manual for Western Washington Volume II- Chapter 4 -Page 387 3" IRON PIPE MAINTAIN SMOOTH THROUGH CURB ft EDGE WHERE POSSIBLE 12" FOR CONCRETE CURB POUR MIN. 4,44 � 12" -1 1 1-1 1 1- / MIN. / 7 -1�1-III-lI- 2 © MATCH EXISTING - - - PAVING TYPE AND -III-III-III- 08 -I1I-I1I-1 1 # DEPTH III-III-III p . � I-III-III-I I ���-__ 1 11-1 11-1 11-_ MIN. _ I-1 1 1-1 -111=111=1 __ � �I 11=111- 1-1 1 1-111- __ I-1 1 111-111 11 .- - -1117 ;�111-111 -_ - - - II 111=, 1111 I I I-III-111-111-111-111= -111 111 „III ,III; -. EXTEND CSTC TO O4 a3 - FULLY SUPPORT CURB IMPORTANT INFORMATION: PRIOR TO ANY CURB REMOVAL, CALL CITY INSPECTOR TO VERIFY THE CURB REMOVAL. THE CONTRACTOR SHALL REMOVE AND REPLACE ANY AND ALL SUNKEN, TIPPED, CRACKED OR BROKEN CURB WITHIN THE PROJECT LIMITS. INSPECTOR TO DETERMINE THE EDGE CONDITION AFTER CURB REMOVAL. NOTES IF INSPECTOR REQUIRES SAWCUT: 1. SCHEDULE CURB REPLACEMENTS AROUND THE PAVING SCHEDULE. 2. FOR CURB AND SIDEWALK INFORMATION, REFER TO SECTION 8-04 AND 8-14 OF THE CURRENT WSDOT STANDARD SPECIFICATIONS. 3. PREPARED SUBGRADE (CURRENT WSDOT STANDARD SPECIFICATIONS 2-06) 4. 4" INCH MINIMUM OF 5/8 CRUSHED SURFACING TOP COURSE (CURRENT WSDOT SECTION 4-04) COMPACTED TO 95% OF MAX DENSITY. 5. INSTALL 3 INCH MINIMUM CLASS B ASPHALT PATCH TO BE COMPACTED TO 92% MAX RICE DENSITY (2002 WSDOT SECTION 5-04.3(10)B). 6. CROSS-SLOPE OF NEW ASPHALT SECTION SHALL BE LESS THAN OR EQUAL TO THE EXISTING CROSS- SLOPE AND SHALL NOT BE LESS THAN 1% WITHOUT APPROVAL OF THE CITY ENGINEER. 7. ALL JOINTS BETWEEN OLD AND NEW ASPHALT TO BE SEALED (2002 WSDOT SECTION 5-05.3(8)B) USING A HOTE POURED JOINT SEALANT (2002 WSDOT SECTION 9-04.2(1)). 8. REMOVE 12 INCHES MINIMUM OF MATERIAL BEHIND CURB. ONCE NEW CURB IS INSTALLED TO EXISTING GRADE, REPLACE WITH COMPACTED DEPTH TOP SOIL (CURRENT WSDOT SECTION 9-14.1). NOTES FOR SMOOTH EDGE: 2. FOR CURB AND SIDEWALK INFORMATION, REFER TO SECTION 8-04 AND 8-14 OF THE CURRENT STANDARD SPECIFICATIONS. 3. PREPARED SUBGRADE (CURRENT WSDOT 2-06) 4. 4" INCH MINIMUM OF 5/8 CRUSHED SURFACING TOP COURSE (CURRENT WSDOT SECTION 4-04) COMPACTED TO 95% OF MAX DENSITY. 8. REMOVE 12 INCHES MINIMUM OF MATERIAL BEHIND CURB. ONCE NEW CURB IS INSTALLED TO EXISTING GRADE, REPLACE WITH COMPACTED DEPTH TOP SOIL (CURRENT WSDOT SECTION 9-14.1). SCALE: NOT TO SCALE DRAWN BY: S.L. 0 . DETAIL: ST-03 FILE: ST-03 CURB REPLACEMENT.DWG CURB AND GUTTER EFFECTIVE DATE: REVIEW BY DATE: REVIEWER: 9ti � REPLACEMENT C 0 RS 01-20-2005 05-31-2013 BUCKENMEYER APPENDIX A - STANDARD DRAWING 2011