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Home My WebLink AboutPermit File BLD-2021-0313 2711 Oakes Avenue (10)Storm Water Drainage Report Minimum Requirements 1 through 5 Minimum Requirement 1 through 9 ENGINEERING DEPARTMENT 904 6th Street Anacortes, WA 98221 www.anacorteswaIg Official Use Only: (Information to Inspectors) Required Storm Water Facility and other related requirements: x P3MP `rr7- 5toc t�az�8aactt� PIP, 64 H1.akZ ,• 'S12.nt�SpcizT cf�coe- s qaQ U� Project Address: Z.7U`Z- 2�111 CAKES 4�ir. Submittal Date: OCc• Z1 • ZoZ.I Parcel Number: FGF�) ( Pe Revision Number: 2. Permit Number: Reviewer: feEF�5re�4L� l J E Acceptance Date COA : oto•29i •Zaz,l 5 FRONT OF REPORT: �_ Submittal Checklist: (All items listed below are required for a complete subm al) o Cover Sheet (Preparer to Provide): Project title, Location, Revision dates, Engineer's Stamp c 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 c TAB 4: Minimum Requirement #4 — Preservation of Natural Drainage Systems and Outfalls o TAB 5: Minimum Requirement #5 — On -site Stormwater Managements .• .. - • APPENDIX I - Survey performed Professional Land Surveyor o APPENDIX 2 - Soils Analysis (Volume 1, Chapter Model•Management Determining Construction Site Sediment Damage Potential (Appendix o APPENDIX 5 - Site Plan with all applicable information (Minimum Size I 1x1 7 — 30 scale) .. • Stormwater Management Requirements: o Refer to the 2012\14 Department of Ecology Manual, as amended in 2014 for further required information. See also, City of Anacortes Municipal Code 19.76 for additional information See also, current Engineering Development Standards, Chapter 2- Storm Drainage for additional nformation. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Proiect Description and Summary, aumma i aoie Development Tvae Exist Proposed Number of Lota Lot Acreage in SF Soil T e s t.5 Site Sediment Trans oort Score Hi4 S57o w aavi LAR21 WVV Depth to Ground Water Table (Feet - ches) See L4 W a� N com /sled Soils Analysis y2lurne 1 Cha ter 3.1.1 Infiltration Rate dudn Kamy Season InchlPer Hour �9 Im ervious Surface on -she Im ervious Surrace otrsite New and Replaced Hard Surface Total SF Lot Covers a Percenta e BMP (Required Minimum Requirement 5) BMP T5.13 Post Construction Soils Water Quality Method Minimum Requirement 8 Water 4udmny Method imimmurn Requirement 7 F�dstino Slte 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 PhasingiSequence ) Developed Conditions Summary• (Additionally, to be shown on the site plan. Identify out and fill areas, proposed slopes of all hard surfaces , proposed contours) Drainage Basin (2007 Storm Com Plan -City websitelpublicworkslengineering\comprehensive plans): What Drainage Basin are you ini (l1 Identify If so, describe: any downstream drainage issues (Storm Comp Plan: Complete the Applicability Requirements -Flow Chart (Figure I.2.4.1 Attached, Figure I-2.4.2 Attached and Figure I-2.5.1 Attached) Highlight the path and attach Version Date: October 7, 2019 Previous Version Data: February 20, 2019 Star! Here CIOes the site have 359b or more of existing moennous coverage? Does the project result it 5,000 square feet, or greater, of new plus replaced hard surface area? Yes See Redevelopment Minimum Requirements and Flow Chart (Figure I-Z*2). Does the project convert �a acres or more of vegetation to lawn or landscaped areas, or NO convert 2.5 acres or more of native vegetation to pasture? All Minimum Requirements apply to the new and replaced hard surfaces and converted vegetation areas. Yet Does the project result in 2,000 square feet, or greater, of new plus replaced hard surface area? Minimum Requirements #1 through #5 apply to the new and replaced hard surfaces and the land disturbed. DEPARTMENT 4F ECOLOGY .1131E of Olvvi` .ZoZ1 Sr2 � Does the project have land ► disturbing activities of 7,Qg0 t--- square feet or greater? Yes NO Minimum Requirement #2 applies. Figure I-2.4.1 Flow Chart for Determining Requirements far New Development Revised June 21! please see nC�s:.vnw ecy,wa.gow'capy?.gtrr.hrmotar cxipyrignt notice Ineluuinmiss g periays, wtttlt3ton Oi IlaDlllty, a'id OlsclaNr�?r. V8r510n U8I8: VC101JBr & F'rBVI0U5 V@rSlOn Uffi0: r-@oNery GU, GU ly TAB 1 (MINIMUM REQUIREMENT 01) • 1.2.5.1 Minimum Requirement 91 — 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 nredpvelnnpd nnnrMinnp ^f fk. �;re -3.1.2 S -frtt� � �b Slu�tes f.L�t[i [ ) -&yv sldpc on pvo sma�'1 1 ep - Prepare Preliminary Development Layout 03 !�i K 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 stonnwater treatment and retention/detention facilities for the proposed development. l" 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 downstream of the project site. "rV1ANG ry ro-N� ro Pa1�'''''� avt t7f�° 'Sj+G yjytgl�s . 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 #5apply to the project; or, whether Minimum Requirements #1 through #9apply. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Please note, that Minimum Requirement #1 through #5 may trigger additional Minimum Requirements, such as Flow Control 1-3.1.5 Step 5 - Prepare a Permanent Stormwater Control Plan (Refer to this section of the Ecology Manual for requirements.) 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 64e� sYP TnB Z. k a�2 �� Si�2UCSla—J Sw'J? 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 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 2 (MINIMUM REQUIREMENT #2) • 1-2.5.2 Minimum Requirement 92 — 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. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Table 4.1.1 Source Control BMP's by SWPPP Element BMPor Element Name Element#1 Preserve VegetationMlark C Icarian Limits Element#2 Establish Construction Access Element#5 Stabilize Sails Element#6 Protect Slopes Element#9 Control Pollutants Element#ll Maintain BMPs Element#12 Manage the Project Element#13 Protect Low Impact Develo ment BMPC101: Preserving Natural Vegetation ✓ BMP C 102: Buffer Zones ✓ ✓ BMP C103: High Vibility Plastic or Metal Fen ✓ ✓ BMP C105: Stabilized Construction Entrance I Exit ✓ BMP C106: Wheel Wash ✓ BMP C107: Construction Road/Parking Area Stabilization BMP C120: Temporary and Permanent Seeding ✓ ✓ BMP C121: Mulching ✓ ✓ BMP C122: Nets and Blankets ✓ ✓ BMP C123: Plastic Covering ✓ BMP C124: Sodding ✓ BMP C125: Topsoiling/Composting ✓ BMP C126: Polyacrylanide for Soil. Erosion Protection BMP C130: Surface Roughening ✓ ✓ BMP C131: Gradient Terraces ✓ ✓ BMP C140: Dust Control BMP C150: Materials On Hand ✓ ✓ BMP C151: Concrete Handling ✓ BMP C152: Sawcutting and Surfacing Pollution Prevention BMP C153: Material Delivery, Storage and Containment ✓ BMPC154: Concrete Washout Area ✓ BMPC160: Cavilled Erosion and. Sediment Control Lead ✓ ✓ BMP C162: Scheduling ✓ Version Date: Ocfober 7, 2019 Previous Version Date: February 20, 2019 Table 4.2.1 Runoff Conveyance and Treatment BMP's by SWPPP Element Element OS FSarmntdtd t]ement A3 Element A7 Elerrant sS ElennMA3 Elomsnt#ig Elcmanl Ala BMP nr Eloa+a nt blame Control Install Pratact ptoteot 8iahlliza Control Conhol Do•Sedit Protect Low Flow Rates Slopes @rain Inlets pests Watering Ielaol Coal Is OudelChn"nals god end Doeste )kOveloamrant OUP C200: Interceptor Dike and Svula ✓. ✓ BMP C201: Grace-t teed Chmiels ✓ BMP C202; Cherinel Lh*V ^T BMP C203: Wator Bars ✓ ✓ — BMP C21041: Pipe Slope @nine ✓ dMP C2W: Subourlaoe thaltn " ✓ . BMP ON: Level Spreader ✓ -- - BMP C207: Chock Dune ✓ ✓ BMP C211e: Triangular Set Dike (Deolealea ✓ - ✓ Encased Check Dan4 _.._-��.>...,.... -__..._. .. _._-. _.M> ....._._....,.....mod.,...-_.... BMP Cue: Outlet Protection ✓ BMP C220: Storm Drain Inlet protection� ✓ BMP C"ll Brush Barter ✓ ✓ BMP C23t Oravel Filler Berm ✓ BMPC2= Sk Fence ✓ ✓ SMPC23lt Vegetaled Ship ✓ ✓ BMPC23& LYattks ✓ - BMP G23B Vepitertive Fllhatlon ✓ - _ - ._._ BMPC24* Sodirmot Trap ✓ ✓ BMPG241: TempowySedirmat Pond ✓ ✓ - BMP C2111k ConSlrc imn Stonnamler ✓ Chwdcal Trealrnallt BMP C251: Conahacllon Stormaater Flnrallon BMP C25t Hlgtt pH t1e01relization Using ✓ CD2 BMP C2M pH Control ror High PH Water FBM Pl ✓ - 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: Site Address:Ljgtr6 Prepared By:_ Dshrc-a ) The Stormwater checklist or building permit determined that: ❑ The.13 elements must be addressed for construction activity adding under 21000 sq. ft. of hard surface area. These elements must be addressed for construction activity adding 2,000 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 aooficable to rovided your protect Use the attached Tabfes n ELEMENT 7: Preserve VegetatioNMark Clearing Limits y' Before beginning land disturbing activities, including clearing and grading, cleady 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. ELEMENT 2: Establish Construction Access �[n`' Limit construction vehicle access and exit to one route, iF possible. �' Stabilize acce$s points with a pad of quarry spalls, crushed rock, or other equivalent BMPs, to minimize tracking onto roads. ❑ Locate wheel wash or tire baths on site, If the stabilized construction entrance is not effective in preventing tracking sediment onto roads. 2( If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day, or more frequently as necessary (ex: wet weather). Remove sediment from roads by shoveling, sweeping, or pick up and transport the sediment to a controlled sediment disposal area. Conduct street washing only after sediment is removed in accordance with the above bullet. D Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tribute to waters of the State. P.�tP-C1RyCtT�Ac�1��oCN17l7�ruw Version Date: October 7, 2019 Previous Version Data: February 20, 2019 ELEMENT 3: Control Flow Rates Protect properties and waterways downstream of development sites from erosion and the associated discharge of turbid waters due to increases in the velocity and peak volumetric flow rate of stormwater runoff from the project site. ❑ Where necessary to comply with the bullet above, construct stormwater retention or detention facilities as one of the first steps In grading. Assure that detention facilities function properly before constructing site improvement (e.g, impervious surfaces). D If permanent infiltration ponds are used for flow control during construction, protect these facilities from siltation during the construction phase. ti✓1t93 )E' 1MfOIA SITE 15 �=LA>r LuILL, u� FXISM 6 GQr V tL c'SV4SlTa Cn1.YS�c ft u dFl= ELEMENT 4: Install Sediment Controls Design, install, and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. !* Construct sediment control BMPS (sediment ponds, traps, filters, etc.) as one of the first steps in grading. These$MPs 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 salmonlds attempting to enter off -channel areas or drainages.Li - 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 rnkimn ELEMENT 5: Stabilize Sails yl" Stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. Applicable BMPs include, but are not limited temporary and permanent seeding, sodding, mulching, plastic covering, erosion control fabrics and d matting, soil application of polyacrylamide (PAM), the early application of gravel base early on areas to be paved, and dust control. ❑ Control stormwater volume and velocity within the site to minimize soil erosion. ❑ Control stormwater discharges, Including both peak flow rates and total stormwater volume; to minimize erosion at outlets and to minimize downstream channel and stream bank erosion. Soils must not remain exposed and unworked for more than the time periods set forth below to prevent erosion. o During the dry season (May 1 —.Sept 30): 7 days o During the wet season (Oct 1 —Apr 30): 2 days ❑ Stabilize soils at the end of the shift before aholiday or weekend if needed based on the weather Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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 S11= tS lbT- Ilse exsriNl' Vt1v�[R.T�1 ELEMENT 8: Protect Slopes Design and construct cut -and -fill slopes in a mannert0 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). l Diver 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 (W WHM) 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 maybe used directly without a correction factor. u Place excavated material on the uphill side of trenches, consistent with safety and space considerations. t7 Place check dams at regular intervals within constructed channels that are cut down a slope, J� 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. Site 15 �*i1.0 Sw�S Version Date: October 7, 2019 Previous Version Date: February 20, 2019 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. ,r 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. ELEMENT 8: Stabilize Channels and Outlets tl 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. JProvide 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. 1r _ m ,�Ei2Flq " C�Jeus be-- O�TLti it T-IE: S I !t ELEMENT 9: Control Pollutants Design, install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants. J0 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 withln 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 Li 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, II 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. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 ❑ 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. Y� Assure that washout of concrete trucks is performed off -site or in designated concrete washout areas only. Do not wash out concrete trucks ontothe ground, or Into storm drains, open ditches, streets, or streams. Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Do not use upland land applications for discharging wastewater from concrete washout areas. ❑ Obtain written approval from Ecology and provide to the City before using chemical treatment other than CO2 or dry ice to adjust pH. Woody debris may be chopped and spread on site. ,PP/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. N raining, over the vehicle. 2 l h c 6MP 6I93 G\y4 0 00� uc ec a -lw 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 specked 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. n 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, ciamshell 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. Version Date: October 7, 2079 Previous Version Date: February 20, 2019 ELEMENT 11: Maintain BMPs j�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. fiPr' Remove all temporary erosion and sediment control BMPs within 30 days after achieving final site stabilization or after the temporary SMPs are no longer needed. Some temporary erosion and sediment control BMPs are bio-degradable and designed to remain in place following construction such as compost socks. ❑ Provide protection to all BMPs installed for the permanent control of stormwater from sediment and compaction. All BMPs that are to remain In place following completion of construction shall be examined and placed in full operating conditions. If sediment enters the. BMPs during construction, it shall be removed and the facility shall be returned to the conditions specified in the construction documents. ❑ Remove or stabilize trapped sediment on site. Permanently stabilize disturbed soil resulting from removal of BMPs or vegetation. Owy.�a2\C�r—.c�e1a tt"e?� w N LL. v.>o�n �cc der` ..%e 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 sub'ef ct to Minimum Requirnts 1-5 do not. re uire the inspector to be art' d. By the initiation of consfrudon, tTie S PP must Identify the CESCL or inspec or, w o s a be present on-siteor 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. D Clearing and grading activities for developments shall be permitted only if conducted using an approved site development plan (e.g., subdivision approval). l7 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. LI 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. Version Data: October 7, 2019 Previous Version Date: February 20, 2019 ELEMENT 13: Protect Low Impact Development BMPS i J If implementing any bioretention facilities or rain gardens, refer to the applicable BMP sections of the Manual for requirements. U1 F �� uSC�f> bl 'R1.0 I QO.�CZT ApplftnfSignature Date Version Date: October 7, 2019 Previous Verslon 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 44) Minimum Requirement #4 — Preservation of Natural Drainage Systems and Outfalis Natural drainage patterns shall be maintained and discharges from the project shell occur at the natural location, to maximum extent practicable. The manner by which runoff is discharged from the project site must not cause significant adverse impact to downstream receiving waters and down gradient properties. All outfalls require energy dissipation. Tha 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 ocation, Refer to the reference manual for supplemental guidelines and additional information under this section. WIII this project disturb the Natural Drainage System or Outfall of the project Site? Yes\No. If yes, refer to section 1.2.5.4 for Supplemental Guidelines for additional information. 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? r{ES (Yes\No) (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). rra.wi 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 10B Downspout Dispersion Systems, or& o BMP T5.10C: Performated Stub -out Connections, or o BMP T5.11 Concentrated Flow Dispersion, or; o BMP T5.12 Sheet Flow Dispersion Projects triggering only Minimum Requirements 1 through 5, shall either: A. Use On -site Stormwater Management BMP's from List #1 for all surfaces within each type of surface in List #1, or; B. 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 Treatments Facilities to achieve the LID Performance Standard. If a project will utilize the LID Performance Standard, then provide and attach reports and calculations. Stormwater discharges shall match developed discharge durations to pre -developed durations for the range of pre -developed discharge rates from 8% of the 2-year peak flow to 50% of the 2-year peak flow. Refer to the Standard Flow Control Requirement section in Minimum Requirement 7 for information abou the assignment of the pre -developed conditions. Project sites that mus also meet Minimum Requirement 7 — Flow Control, must match flow durations between 8% of the 2-year flow through the full 50 year flow. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Projects triggering Minimum Requirements 1 through 9, must meet the requirements in 1-2.5.5 Minimum Requirement 5 — On -site Stormwater Management. o Refer to Table 1-2.5.1 On -site Stormwater Management Requirements for Projects Triggering Minimum Requirements 1 through 9 in the Department of Ecology Manual. 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 s 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/lpdf/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. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX 1 - Survey performed by a Professional Land Surveyor The object of this appendix is to ensure that the property has a minimum of 3 out of 5 property corners visible to ensure that the structures are placed within the required setbacks. LM11i't {a1b1W KO fef7' q COvY Z2 r low . Version Date: October 7, 2019 Previous Version Date: February 20, 2019 o 7� Y a a� w, z a 9 ems+ d p w• om � o 0 0 �a 3�o 0 Mau u�-b mw z� in NZ o �o --ad AAA< o Ing o s w - $ ��t-z Vxw o e a a _ od�o . Abe AS III It IF Ito IT MIN UT op, ew 6 12 - J Xapmm ° N� ova Q ws� m zoo 9,s Qolo m Zoo w�mmI Oy zz 4Z00E0506[0Z IIIIIINIIIIIIIIIIIIII111111111111�1111111!IIIIIII!IIIIIIIIIIIIIIIIINIIIIIIIII APPENDIX 2 - Soils Anaylsis (Volume 1, Chapter 3.1.1) iHg�-\JeCT 1ST i�E�c?D� CAFE �CE��i tw 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#_or_pages Complete all Information on page 1; only site address and permit number on dditi 1 pages r RYi.L'_tl:S:lJ:I.Yl�J't4�r, Ju. l!. Fff 1' AREA # (should match Atzn # on SYte Planl PLANTING TYPE L if Until sturb d native Vegete0on 2 Plantin6 Reds �L ,Other. 'I'Y'pGS SQUARE FOOTAGE OF THIS AREA: _ square feet SCARIFICATION _ inches (depth) of scarification needed to achieve finished total 1 Joosened depth. _ Subsoil will be scarified PRE410PROVED inches of compost or imported topsoil applied AMENDMENT METHOD: XX 41 (convere sionfactor, inches to ubicyards) PRODUCT: _ Topsoil import = am. yards per 1,000 sq. ft. _ Amend with compost X ,i sq.ft. in this area Stockpile and amend _ = cubic yards of amendment —. —. -. —. QUANTITY: CU, YDS, cu. yds. stoc iled needed to cover this area to deli aced depth) CUSTOM AMENDMENT Attach test results Una calculations. _Topsoilimpurt 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 QUANTrrY: CU, YDS. MULCH 000 sq.ft. PRODUCT: X (canvesion, togive 2 inch mulch depth) = cubic yards of mulch —. —,. —. —a —. QUANTITY: CU. yDS. Version Date: October 7, 2019 Previous Version Dale: 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. Version Date: October 7, 201g Previous Version Date: February20, 2019 Western Washington Phase 11 Stormwater Permit 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. STEP 1—Sediment/Erosion Sensitive Feature Identification Sediment/erosionsensttive features are areas subject to significant degradation due to the effect of sediment deposition or erosion. Special protection must be provided to protect them. Sedimentterosion sensitive features include but are not limited to: L Salrnonid 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, Il, 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. STEP 2 — Hvdraulic Nearness Assessment Sites are hydraulically near a feature if tke. 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, 2Q13. Modified January 1 �, 2ti15 fip�esaefix 7- taetemrining Sediment f)arnage Potential Page 9 df 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. . 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 11100 High A high transport rating indicates a higher risk that the site will generate sediment contaminated runoff. Construction Site Sediment I ransport Potential Workshem A. Existing slope of site (average, weighted by aerial extent): Points 2% or less, 0 > 2 - 5 % ..................................................................................I....:.....15 >5-10%...................................................:..................:.......I....I......15 >10-15% ...A ................. 30 >15%....:.........................1.........,..........,.. 50 B, Site Area to be cleared and/or graded: <57000 sq. ft.............................................................I........I......... 5,000 sq. ft. — 1 acre ..... .:.........................................................A....30 >1 acres.....................................................:.:.......:.......................50 C. Quantity of cut and/or fill on site: <500 cubic yards ... ..........................................................I.........I. 00 500 - 5,000 cubic yards ........ ............................",,,M.....:.....I............15 >5,000 — 10,000 cubic yards ....... ......:...........::............I.......:.........10 >1000 — 20,000 cubic yards.. .......................... P.A .... I I I I I I I I I I I ..... ... 25 >20,000 cubic yards,....................................................................40 D. Runoff potential of predominant soils (Natural Resources Conservation Service): soilgroup A......................................,..............................................0 Hydrologic soil group B.......... ................. ....... ......",.............. ........10 Hydrologic soil group C.... ..............................:............................6 Hydrologic soil group D ........ ....... ,...... 40 E. Erosion Potential of predominant soils (Unified Classification System): GW GP, SPsoils...............:.....................................:.................I..:...............0 Dual classifications (GW-GM, GP -GM, GW-GC, GP-G SW-SM SW SC SP SM SP SC) ............... 10 G SM SC soils ............... 20 MLC CH soils ......... ............ A..........................:40 F. Surface or Groundwater entering site identified and intercepted I: Yes........::......:........................................:..................................I.. No.................................................................... ........................2 G. Depth of cut or height of fill >10 feet: Yes..",.... ......................................................................................25 No....................... .........:...................... ...... ............ .........:......... .:.......... � R Clearing and grading will occur in the wet season(October1 . May 1): Yes 50 Nod .....................................................:.........:...........................I...I.......Q TOTAL POINTS .......................... 1 If no surface or groundwater enters site, give 0 points. 0 6E 7�� 2� Hydrologic SW, utfl.25.2oz,l S� APPENDIX 5 — Site Plan with all applicable information (Minimum Size 11x17 at a legible scale) �?o rr 7 APPENDIX 6 - Documented Site Photos (Show all directions of the site, including frontage) (Insert Photo Here) Location: Description of the photo: Photo taken by: