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Permit File BLD-2021-0313 2711 Oakes Avenue (7)
Storm Water Drainage Report Minimum Requirements 'I through 5 Minimum Requirement 1 through 9 ENGINEERING DEPARTMENT 904 6t' Street Anacortes, WA 98224 www.anacorteswa. ov Official Use Only: (Information to Inspectors) Required Storm Water Facility and other related requirements: Project Address: v� Parcel lumber: ;1M Permit Number - FRONT OF REPORT: T: Submittal Date: Revision Number: mber: Reviewer - Acceptance Date CA): Submittal Ch o Cli f; (All items listed below are required for a complete ubrrrfttal) o Cover Sheet (Preparer to Provide): Project title, Location, Revision dates, Engineer's Stamp o TAB 1. Minimum Requirement ##1 — Preparation of Storm water Site Plants o TAB 2. Minim urn l equirement #2 — Construction Stormwater Pollution Prevention (SW PP) o TAB : Minimum Requirement # — Source Control of Pollution o TAB 4: Minimum Requirement #4 — Preservation of Natural Drainage Systems and Outfalls o TAB : Minimum Requirement # — Oct -site Stormwater Managements o TAB 6, Minimum Requirement # — Runoff Treatment o TAB 7: Minimum Requirement ##7 — Flour Control o TAB : Minimum Requirement #8 —Wetland Protection o TAB 9: Minimum Requirement #9 — Operation and Maintenance o APPENDIX 1 - Survey performed by a Professional Land Surveyor o APPENDIX - Soils Analysis (Volume 1, Chapter .1.1) o APPENDIX 8 - Model Soil Management Pram for BMP T5.1 o APPENDIX 4 Determining Construction Site Sediment Damage Potential (Appendix 7) o APPENDIX 5 - Site Plant with all applicable information (Minimum Size 11x17 — 30 scale) o APPENDIX - Documented Site Photos (Forth, South, East and West) o APPENDIX 7 - Drainage B P Facility Maintenance Covenant, if applicable. To be recorded prior to the Temporary Certificate of Occupancy, Certificate of Occupancy or Final Acceptance. t rmwater Management Requirements: : o Refer to the 2 1 114 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 - Storm, Drainage for additional information. Version Date: October 7, 2019 Previous Version, Date: February 20, 2019 Project Description andSummary: urnmary Table Dev!e w ent � Number of Lots Lot Acreage in SF Soil? pes Site Sediment Transport Score Hi h1Low Depth to Ground eater Table (Feet and Inches) see corm feted Soils Anal i 1 olumlel 1, Chap ter 3.1. 1 Infiltration Date during Rainy -Season In hTer Hour Impervious Surface on -site Impervious Surface off -site New and Replaced Hard Surface Total F Lot Coverage (Percentage) BMP (Required Minimum Requirement ) Neater Quality Method Minimum Requiremen Neater Quantity Method Minimum Requirement 7 Existin FA BMP T5.13 Post Construction Soils Proposed 4W Existing Site Conditions Summary: (Additionally, prOvide information on previous permits, if any, like Grade and Fill, Ctear and Grade, topography, vegetation, drainage, Critical Areas adjacent to the site and how it may affect this proje f if scfl are disturbed, Sails Type Included in Soils Analysis Report), Erosion Problem Areas, Construction Pha inglSe lu nce ) Developed Conditions Summary: (Additionally, to be shown on the site plan, Identify cart and fill areas, proposed slopes urffs , proposed contours)o !} bard Drainage Basin (2007 Storm Comp Plan — City webs itelpublicworkskengineering\ orn preh en sive plans): What Drainage Basin are you ire? Identify any downstream drainage iComp Storm Co� If so, describe: p Plan. * t, An. V Complete the Applicability Requirements — Flow Chart (Figure I- . .1 Attached, Figure 1-2.4,2 Attached and Figure 1-2..1 Attaed) - Highlight the path and attach Version Date. October 7, 2019 Previous Version Date: February 20, 2019 Hart Here Does 0-e site have 35 or more of axl-sn"I;I* No Dues the project res;j1? 1n 5.000 sqtoare feeL or No greater. of new plus replaced hand surface area') Yes All Minirnwn Requirements apply to the new and replaced hard surfaces and converted vegetation areas DEPARTMENT OF ECOLOGY equ°remen. ts ana %w Cha4 (Figure 1--.4.). Doe s the Project ven ,acres or rr ore cf -E. t30Non ;o lawn or lap dscpip a reas. or oc>n 2.5 acres or more of native ': eg tati n w pa t=j re'7 Minimum RequirementsRequirementso I through #5 apply to the new and replaced hard surfwes and the land disturbed_ No Does the prcoct result 'n '�. i C sgts a - feet, or g?-e ater. of new P;,a rev I ---ed haro s urfaoe area? Yeses - I No a s the Projeqcl have land disturbing activibes or 7.O0C) Vey I sq ua re feet or gre.'4 ► er? No Minimum Requirerrwnt 0 applies. Figure 1-2,4. I Flaw Chart for Determining Requirements for New Development I -* A. j .hone 2a if *I 3Sf. a -6-6,1 ). 4a 90"'Cr 0c rIg ,'fDr DOP 921! 1obC-e Ir4,lwir� version LJai : UCIDDer t, zwi-'reviousversion uate: reofuary zu, zu r D oe s fl` I LEI L • r u�t .OIL LI * - � or .tiff new plus replaced hard surface ar@a 7 1 R oes the rand d1sturbing acti vOry tota1 7. DOO squ.-4' e fit or greater? y e k1inirrrunr Requirements #I throulph apply to the new and replac l hard surl,aoes and the lard dhst ed _ Text Quettion No Minimum lequirennt 002 applies. Does the pro ►ct ;add 5, 0C square l et or MOM of f'** hardsurfaces,' OiR on vwt 3,; acres or mo re # vege t on to lawn or Iar~Idscap d areas'' o Convert 2,5 acfes C f r+ajw Yes No All Minimum Requirements apply Next Question t the new hard s urfaoes and the is the s � rand converted vegetation areas. related pr *l? Yes 1 -s Y h P -�j�e- t as j f , 0 Co sgLiam fee; c r ore of near harra sj-f ace s' Yes Do the Mew hard su ac add � I or more to the exta r hard surfaces iohor the prjject !,nets':' Yes DEPARTI,+aNT C= ECOLOGY No No: o additional requirements No Is the total of new plus rep ced hard SLrfaCes 5.D00 square feat or mom. No ANC Joe s .h. a value of the propo sed impn rer r- .; - .5 - including imtencr imprrave" - exceed 50 o" the assessed value (r replacemem.. V 31ue i of tie a M. ist ing 5 ite wnp roverner .s All Minimum Requirements apply to the new and replaced hard surfaces and converted vegetation areas. Yes FigUre 1-2.4,2 Flow Chao for Determining Reqfor Redevelopment R*Med june 20 i! PiemA- a . t�;.. •t4wa K � ^a gz. :+J��f �1.�t�11�� l��'r ,j! -10� Nn�hu':$ng rrr+ ns. l ul tilul I Udle_ UUl 01-ar f OrL i i *4 0-r R.rtjc 4•r.... . ..._• _ TAB 4 (IIAi'lVlMtiM REQUIREMENT ENT t) • 1- ..1 Minimum Requirement # 1 — Prepare a Stormwater Site Plan 1.3 — Preparation of a Stormwater Site Plan - 1.3.1 , Stormwater Site Plans: Step -bar -Step ftte: The level of detaii needed for each step depends 4POn the project size. Provide a narrative description of each step. 1- .1.1 Step I - Site Analysts: 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 predeeloped conditions of the site. t—f-U rt� F 1-3.1.2 S e2 Prepare , p - p e Preliminary r Development nt LayoutWttWNW Based upon the analysis of existing site conditions, locate the buildings, roads, parking lots, landscaping features, ors -site stormwater management BI P° , and preliminary location of stormwater treatment and retention/detention facilities for the proposed development. 1-3.1.3 Step 3 - Perform Off -site Analysis (at Local Agency's Option): Use additional Sheets, if necessarl Ecology recommends that local governments require an off -site analysis for projects that add FOOD SF or more of new hard surfaces, or convert 34 acres of vegetation to lawn or landscape areas, or convert 2. acres of forested area to pasture. p Off -site analysis extends to Y, mile downstream of the project site. . ;A1_8.. -1 _3 A.A 1 01 1-3.1. - Determine Applicable Minimum f equirements Establish project size thresholds for the application of Minimum Requirements to new development and re6evelopment projects. Figures 2.4.1 eta hed and 2. .2 Lj a hed provide the same thresholds in a flow chart format.. Based on the preliminary layout, determine whether Minimum Requirements ments 1 through #5 apply to the project; or, whether Minimum Requirements nts 41 through #9 apply. Version Date: October 7. 2019 Previous Version Date: February 20, 2019 Please notet that Minimum Requirement #1 through #5 may trigger additional Minimum Requirements, such as Flow Control. i A 13 I , �� 1-3.1.5 Step 5 - Prepare a Permanent Stormwater Control Plan (Refer this section of the Ecology Manual for requirements.) 2 1-3.1.6 Step 6 - Prepare a Construction Stormwater Pollution Prevention Plan ( MR## — 1 Elements Defer to Chapter 11- — Planning for a detailed description of each element. See also attached Tables 4.1. 9 (Source Control BMP's bY SWPPP Element) and Table 4.2.1 (Runoff Conveyance and Treatment B P's b}r S WPPPElement). See attached 13 Elements of a SWppp, please complete and attached 1-3.1.7 Step 7 - Complete the stoat water 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- 0 Project Overview • Existing Conditions Surnmary • Off -site Analysis Report • Permanent Stormwater Control Plan + Construction Stormwater Pollution Prevention Plan • Special Reports and Studies a Other Permits • Operation and Maintenance Manual • Declaration of Covenant for Privately Maintained Flag Control and Treatment Facilities. (See attached Drainage BMP Maintenance Covenant 8 P Agreement) Declaration of Covenant for Privately MaintainedOn-site Stormwater BIVIP's (See attached Drainage SNIP Maintenance Covenant BMP Agreement) • Bond Quantities Worksheet, if applicable Version Date; October 7, 2019 Previous Version Date: February 20, 2019 1- .1.8 Step 8 - Check Compliance with all Applicable Minimum Requirements Stormwater Site Plan as designed and implemented should specifically fulfill all Minimum Requirements applicable to the project. The Stormwater Site Flan should be reviewed to check that these requirements are satisfied. Version Date: October 7, 2019 Previous Version Date: February 20, 201 TAB 2 (MINIMUM REQUIREMENT UIF EMENT ) • 1-2. . 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. . 1 and Table - Provide Engineering Calculations as are attachment for Sediment Ponds\Traps, Diversions, Waterways and Runoff/ tormwater Detention Calculations. 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 (SWIV!WW). 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 11ork's page. Owner Narne- Qite Address: The Stormwater checklist or building permit determined that: The 13 elements rest be addressed for construction activity adding under 2,000 sq. ft. of hard surface area. Under each element -..Provide the BMP's that will be a Provided. ELEMENT 1: Preserve Vegetation/Mark Tearing Limits 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. Tables 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 lager, native top soil, and natural vegetation in an undisturbed state to the maximum degree practical. ELEMENT : Establish Construction Access Limit construction vehicle access and exit to one route, if possible. Stabilize access points with a pad of quarry spalls, gushed rock, or other equivalent BMPs, to minimi tracking onto roads. e 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 sit , clean the affected roadway thoroughly at the end of each day, or more frequently as necessary ex: wet weather. Remove sediment from roads pick up and transport the sediment to a controlled sediment di osalare by shoveling, sweeping, or Conduct street washing only after sediment is removed in accordance with ._ Control street gash wastewater b pur�p'rr� back on site or other the above bullet. into systems tribute to waters of the State, use preventing it from discharging 7 All 1111111 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 ELEMENT R Control Flow Fates 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 flog 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 site improvement p p o coconstructingp e.g. impervious surfaces). If permanent infiltration ponds are used for flow control during construction, protect these facilities from siltation during the construction phase. ��2,01!7 ELEMENT : Install Sediment Controls Design, install, and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. Construct sediment control BIPs (sediment ponds, traps, filters, etc.) as one of the first steps in grading. These B 1Ps 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 maybe discharged without a sediment removal B P, but ,must meet the flow control performance standard in Element #, bullet ##1. Locate BMPs intended to trap sediment ors -site in a manner~ to avoid interference with the movement of juvenile salmanids attempting to eater- off -channel areas or drainages. Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal, and maximize stormwater infiltration. Where feasible, design outlet structures that withdraw impounded stormwater from the surface to avoid discharging sediment that is still suspended lower in the water column. 2 ELEMENTS: Stabilize Boils Stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. BIVlPs include, but are not limited to: temporary and permanent seeding, sodding, mulching, Applicable covering, erosion control fabrics and matting, soil application of al acrg lamide P hang, plastic p y { I1�1�, the early application of gravel base earl} on areas to be paged, and dust control. Control stormwater volume and velocity within the site to minimize soil erosion. Control stormwater discharges} including both pear 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 urwor ed for more than the time periods set forth below to r erosion. prevent o Dudng the dry season (May 1 — Sept 0): 7 days o During the wet season (Oct 1 Apr o): 2 days Stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather Version Date: October 7, 2019 Previous 1ler ion Datem Fabra 13 g 20 rY 7 1g forecast. Stabilize soil stockpiles from erosion, protect with sediment trapping ,measures, and where located array from storm drain inlets, waterways, and drainage channels. possible, �� Minimize the amount of soil exposed during construction ction activity, Minimize the disturbance of steep slopes. Minimize soil compaction and. unless infeasible, preserve topsoil. ELEMENT : Protect Slopes Design and construct cut -and -fill slopes in a manner to minimize erosion. Applicable practices but are not limited to, reducing continuous length of slope with terracing and diversions reducing sllopop e steepness, and roughening slope surfaces Esc: track walking). f u�n� Divert off -site stormwater (runt -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. t the top of slopes, collect drainage its 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-gear, 2 -hour frequency storm for the developed condition. Alternatively, the 10-gear, I -hour flow rate predictedlindicated by an approved continuous runoff model, increased by a factor of 1. , may be used. The hydrologic analysis must use the existing land corer condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis ,,rust use the temporary or permanent project land comer 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 1 -minute time steps are available in an approved continuous runoff model, they rotary 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. Esc: Use both mulching and straw erosion control blankets. 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 enter the conveyance system without first being filtered or treated to remove sediment. does not Clean or remove and replace inlet protection devices when sedirnent has filled ono -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 reds clean. Do not allow sediment and street wash water to enter star without prior and adequate treatment unless treatment is provided before the storm drain dischargesa waters of the State. to Inlets should be inspected weekly at a minimurn and daily during storm events. ELEMENT : Stabilize Channels and Outlets Design, construct, and stabilize all on -site conveyance channels to prevent erosion from the following expected peak flows: g 0 `Channels must handle sane peak vOlurnetric flow rate as temporary pipe slope drains listed in Element 6, above. Provide stabilization, including armoring material, adequate to rear straa�rr�banlcs, slopes, and downstream reaches at the cutlets of all conveyancprevent erosion of outlets, adjacent The best method for stabilizing channels is to completely lino the channel witha systems. blanket product first, then add cheep dams as necessary to function as as anchor and to slow the flow of water. ELEMENT : Control Pollutants -100*4 Design, install, implement, and maintain effective pollution prevention discharge of pollutants. p n rneaures to rn�n�rri�e the Handle and dispose of all pollutants, including waste materials and de in a manner that does not cause contamination of stormwater, demolition debris that occur on -site F1 Provide cover, containment, and protection from vandalism for all chemicals, liquid products p etro products, and other materials that have the potential to pose a threat to human health or the= Ieurn 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 lamest 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 ill rreventi control measures. dean contaminated surfaces immediately following any spill incident. on and LDischarge wheel wash or tire bath wastewater to a separate on -site treatment system that prevents discharge to surface water, such a closed -loop recirculation or [upland land application, or to t sanitary sewer, with local sewer district approval. �iheel wash or tire bath wastewater shouldh include wastewater from concrete washout areas. not Apply fertilizers and pesticides in a manner and at application rates that will not result in ioss of chemical to stormwater runoff. Follow manufacturers' label requirements for application rates an procedures. p d Version Date: October 7, 2019 Previous Version Bata: 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. Assure that washout of concrete trucks is performed off -site or in designated concrete washout r a eas only. Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Do not use upland land applications for discharging wastewater from concrete washout areas. Obtain written approval from Ecology and provide to the City before using chemical treatment other than CO2 or dry ice to adjust pH. Woody debris may be chopped and spread on site. . e Conduct oil changes, hydraulic system drain down, solvent and de -greasing cleaning operations, erations 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. P G*3 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 net route clean dewatering water through stormwater sediment ponds. Nate 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. Hand)e highly turbid or contaminated dewatering water separately from stormwater. Other treatment or disposal options may include: 1. Infiltration . Transport off -site in a vehicle, such as a vacuum flush truck, for legal disposal in a mariner that does not pollute state waters. . Ecology -approved on -site chemical treatment or other suitable treatment technologies. 4. Sanitary or combined sewer discharge with local sewer district approval, if there i no other option. . Use of a sedimentation bag with outfali to a ditch or Swale for small v0lurnes of localized dewatering. L Construction equipment operation, clarnheli digging, concrete trernie 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, 2019 Previous Version Date: February 20, 2019 ELEMENT 11: Maintain BIVIPs 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. ,,�r Remove ove all temporary erosion and sediment control BMPs within 30 plays 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 sods. © Provide protection to all BIVIPs installed for the permanent control of stormwater from sediment and compaction. All BMPs that are to rerr7ain in place following completion of construction shall he 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. QJ?03 R t ( �X) - ELEMENT 12: Manage the Project — Projects subject to Minimum Requirements 1-9 must have a Certified Erosion and Sediment Control Lead ( EBDL) for site inspections. Projects subject to Minimum Rnia is 1-5 do not require the inspector to be certifl d. By the initiation of construe ,on, the S VPPP must identify the E DL or inspector, W o s a l 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 erasion and prevent transporting sediment from the site during construction. Inspection and monitoring — Inspect, maintain, and repair all BMPs as needed to assure continued performance of their intended function. Maintain, update, and implement the SWPPP. Clearing and grading activities for developments shall be permitted only if conducted using an approved site development plan (e.g., subdivision approval). From Oct 'I 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. . Limit activities and the extent of disturbed areas. . 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; . Routine maintenance of public facilities or existing utility structures that do not expose the soil or result in the removal of the vegetative corer to soil . Activities where there is 100% infiltration of surface water runoff within the site in approved and installed erosion and sediment control facilities. Al Version Date: October 7, 2019 Previous Version Date: February 20, 2019 ELEMENT 1 : Protect Low Impact Development B PS If implementing any bieret ration facilities or rain gardens, refer to the applicable B 1P SOCtions of the Manual for requirements. ppli ant Si-qnature Date Version Date: October 7, 2019 Previous Version Data: February 20, 2019 TAB 3 (MINIMUM REQUIREMENT #3) 0 1- . .3 Minimum Requirement #3 •- Source Control of Pollution All known, available and reasonable source control B 1P'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 B P's is to prevent stormwater from coming in contact with pollutants. They are a cost-effective means of reducing pollutants in stermwater, and, therefore, should be considered an all projects. Singlearnil l e idential Construction Projects and Residential Subdivisions are �_x errtr rnthis Minimum equirement - All Commercial Properties, Industrial Properties, and Multi -Family Properties, Boatyards, Sand and Gravel Mining Opertations are required to cernpl r with this Minimum Requirement. Refer to Chapter IV- .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 94 -• 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? Yes11\10. If fires, 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 UIF EMENT # ) • Minimum Requirement #—On-site Stormwater Management Project thresholds that trigger Minimum Requirements #1 through # , shall utilize theOn-site Stormwater Management 1P's from List #1 for all surfaces Within each typo of surface in List !#1 • or, Demonstrate compliance with the LID Performance Standard. Projects selecting this option cannot use Fain Gardens. They may choose to use Bioretention B 1P's as described in Chapter 1f- — Infiltration and Bioretention Treatment Facilities to achieve the LID Performance Standard. Refer to this section of the reference )Manual for all Feasibi� or InfeasCriteria for List #1 and List #. Is this project Flow Control Exempt? *_ e 1 o) (See Appendix 1-E. Flow Control -Exempt Water). If es r�ra� �errrp# , provide reasoning from the applicability section of 1- .8.7 Minimum Requirement 47. Flow Control). If No, then the project triggers Minimum Requirement #7 (1-2. . and possibly Minimum Requirement #8 (1-2. .81. If the project is Flew Control Exempt, select from the list below (Skip List 1 and List 2). o 8MP T5.13 Post Construction Soils duality and Depth B lP T .1O : Downspout Full Infiltration, or; B M P T8.10B Downs pou t Dispersion Systems, or; o B P T .10 : Performated Stub -out Connections, or; o BMP T5.11 Concentrated Flog Dispersion, or; o BAP T.12 Sheet Flow Dispersion Projects triggering only Minimum Requirements 1 through 5, shall either: A- UseOn-site Stormwater Management S 1P's from List ##1 for all surfaces within each type of surface in List 1, or; P 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 -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 % of the -year peak flow to 0% of the 2-year peak flow. Refer to the Standard Flog Control Requirement section in Minimum Requirement 7 for information atbou the assignment of the pre -developed conditions. Project sites that mus also Minimum Requirement 7 — Flow Control, must match flow durations between % of the - meet through the full 0 year flog. dear dew Version Date: October 7. 2019 Previous 1lersiorl Date: February 20, 2019 Projects triggering Minimum Requirements 1 through 9, must meet the requirements in 1- . . Minimum Requirement 5 —On-site Stormwater Management. o Refer to Table 1- . .1 On -site Stormwater Management Requirements for Projects Triggering Minimum Requirements I through 9 in the Department of Ecology Manual. All sites are required to utilize BMP T5.1 — Post Construction Boil Quality and Depth. For each surface, consider the BMP'in the order listed for that type of surface. Use the first BMP that is considered feasible. No other ors -site Btormwater Management BIVIP is necessary for that surface. Feasiblity shall be determined by evaluation against: . Design criteria, limitations and infeasiblity criteria identified for each BIVIP in this manual, and; . Competing needs criteria listed in Chapter - —On-site Stormwater Management. Lawn and Landscaped Area: • BIVP T .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 BIVIP. htt :11www.soilsforsalrnon.or 1 df/Soil BNAP Manual. df See Appendix 3 for the "Model Soil Management Plarr 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 sods to be used meet the specifications outlined under Minimum Requirement 5. The specifications are in both W D T 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 , the Test Report will be provided to the Building Department. Projects triggering Minimum g 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 List #1 — Project Tri-merina Minimum Requirement 1 throe h For each surface, consider the BIVIPs in the order Jisted for that type of surface. Use the first BMP that is considered feasible. No thenOn-site Stormwater Management BMP is necessary for that surface. Provide feasible detail under each B iP with maintenance and operations specifications in Minimum Requirement 5, Roofs: List 41 BMP T . 0: Full Dispersion easi fea i If infeasible, explain the criteria. r, T .10 : Downspout Full Infiltration Fea iblellnfeasible If infeasible, explain the criteria: . BMP T .14 : Baia Gardens Feasible\]nfeasible If infeasible, explain the criteria: Or, BMP T7. 0: Bioretention Cells, s ales, and Planter Bones Feasible0feasible If infeasible. explain the criteria: . BMP T A OB: Downspout Dispersion Systems Feasible\lnfeasible If infeasible, explain the criteria: 4. BilrrlP T .'10 : Perforated Stub -out Connections Feasiblellnfeasible If infeasible, explain the criteria: Version Date: October 7, 2019 Previous Version Date: February 20, 201 W- Other Hard Surfaces: List #1 "I. BMP T. 5.30 Full Dispersio Fea \Infeasible If infeasible, explain the criteria: . BMP T5.1 : Permeable Pavements Feasiblellnfeasible If infeasible, explain the criteria: r, BMP T.14-A: Rain Carders FeasibleAnfeasible If infeasible, explain the criteria; r, BMP T7. 0: Biorention Cells, Swales and Planter Bones Fearsiblelinfeasible If infeasible, explain the criteria: . BMP T5.1 : Sheet Flow Dispersion Fea ible\lnfeasibl If 'infeasible, explain the criteria: r, BMP T5.11: Concentrated Flow Dispersion Fea iblellnfeasible If infeasible, explain the criteria: icant Signature Date Ce[LIZ02-wi Version Date: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX 1 — Survey performed by a Professionai Land Surveyor The object of this appendix is to ensure that the property has a minimum of 3 out of 5 property corners risible to ensure that the structures are placed within the required setbacks. Version Date: October 7, 2019 Previous Version Date: February 20, 201 APPENDIX 2 -- Soils Ana is is (Volume 1, Chapter .1. "1) oview gqdl ft tx Il�ot � sav-eoL *t4A, ka!�4h kw h bwu - Version Dante: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX 3 — Model Sall Management Plan for BMP T .1 n 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 Il D T 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 I 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 T FROM SOILS SUPPLIER TO THE BUILDING DEPT. PROJECT INFORMATION "Model Soil Management Plan for BMP T .1 " age 4, of, pages Cori Iete all information on page 1; only site address and permit number on additional pages. Site Address I Lot No.:Ce c, A v` Permit Type: Permit Number; Permit Holder: Phone: Mailing Address: - Contact Person: Plan Prepared Bv: ATTACHMENTSREQUIRED (Check Phone: .'7i.0A- feIWF aired ilerms thaI are attached to thisplan Site Plan showing, to scale: Areas of undisturbed nature vegetation (no aImendment required) New planting beds and turf areas (amendment required) Type of s i 1 improvement proposed for each area NO.H V Soil test results (required if ro osin custom amerrdmertt rate Product test results for proposed amendments AREA # (should m atch Area #on Site Plan PLANTING TYPE J_ Turf a Undisturbed native vegetation Planting Beds Other: Mfg SQUARE FOOTAGE OF THIS AREA,: � Square feet SCARIFICATION , inches (depth) of scarification needed to achieve finished total 1 " loosened depth. Subsoil will be scarified PRE -APPROVED AMENDMENT :METHOD: Topsail import Amend with compost -/ Stockpile and amend ( Cu. yds. stockpiled CUSTOM AMENDMENT Topsoil import Topsoil & compost lift Amend Stockpile and amend cu. yds. stockpiled) PRODUCT: QUANTITY- CU. YIDS. PRODUCT - QUANTITY: CLJ. YDS. MULCH _ '000 sq. , PRODUCT: . (conversion, to give 2 in c h ?n u Ich depth) cubic yardsof mulch � -� � -� � -� QUANTITY: :� U. YDS. TOTAL A ENDMENVT PS }ILIMULCH FOR ALL AREAS icomeleie on pgSe I only, lotaiin all areas a es in this Plan) s. FLJT duct #1: ❑ Quanti t Results: % or anic matter C:1 ratio :1 a cee t mulch, or 3 :1 for nativcu•laadits stableProduct # 2 • eslno ) ❑ Quantity: cu. yds. ❑ Test Results: % organic matter C:N ratio 5:1 ( ce t rrrui h, or 3 :1 for native plants} "stable" (yes/no) ❑ Product ##3: ❑ Quantity: cu. ydti, EJ Test Results: % or anic matter :N ratio <25 A (except M ulch, or <3 :1 fornatiVeplants) ##stable" ( cslno Date: Inspector: Approved: Revisiom Required: Date: Inspector: Approved: Revisions Required: inches of compost or imported topsoil applied ;1 (conversion factor, inches to cubicyards) _- cu. yards per 1,000 sq. ft. _ 1000s sq.ft. in this area = cubic yards of amendment - - —(needed to cover this area to desi crated depth) Attach test results and calculations. _ inches organic matter or topsoil import 3.1 �T cu. yards / 1,000 sq. ft_ ,000s sq.f#. in this area - = Cubic yards of amendment Version Date: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX - Determining Construction Site Sediment Damage Potential (Appendix 7 - NPDES Phase iI Permit) (Vote: See attached, All projects within the City of Anacortes are required to complete that document under Appendix 4. Version Date: October 7, 2019 Previous Version Gate: February 20, 2019 Western Washington Phase H 'to"nwater 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 prier 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 asediment/erosion sensitive future 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. TEP — 'rrn r tlEr i Sensitive eature Identifi 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. edimentlerosion sensitive features include but are not limited to: 1. Salmonid bearing fresh water streams and their tributaries or freshwater streams that would be Salmonid bearing if not for anthropogeanic barriers; ii. Fakes; iii. Category I, 11, and 111 wetlands; IV. Marine near -shore habitat; V. Sites containing contaminated soils where erosion could cause dispersal of contaminants; and V1. Steep slopes (2 % 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. M. gTE2.2— Hydraulig NUrness. 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 hydraulicallynear to a feature include, but are not limited to, the following: 1. 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, 1,: , Modified January 16, 2015 Appendix - Dctermh7ing Sediineat Damage Potential Page I of Version Date: October 7, 2019 Previous Version Date: February 20, 2019 site is not hydraulically blear a feature if one of the following tales place to provide attenuation before runoff from the site enters the feature: IV, Sheet flow through a vegetated area with dense ground cover V. Flour through a wetland not included as a sensitive feature i. Flew 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 rear the site, the assessment is complete. Using the wort sheet below, determine the total points for each development site. Assign points based on the most critical condition that affects 1 % 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 I.D) and Erosion Potential (Table of Water Features for step 1.E) When using the county soil surrey, 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 sail types may be present on a site. In this vase, the soil type resulting in the most points on the rating system will be assumed unless site soiil 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. Totai Score Transport Rating 1 00 Low 100 High high transport rating indicates a higher risk that the site will generate sediment contaminated runoff, Construction Site Sediment Transport Potential Worksheet A. Existing !o a of site average,weighted by aerial extent : Points %orJ/y less - -A.Rfr%i.........i,4hNONE i,riL.tt.hlli...+.*+#rtrtt.OPEN 4i...+fltt.tENO i..... T. -1 0% .........i..•i.++...t......,t.... ... •..........i...t...rt......i,,....aiir...ilii.. ..iairt...■ 510-1 % ...........................0 +......rrrt......Y..---+#i•••••,h......Fii......r.. .ir... 1 °o t..t.i.i...liir#...is+ii....iri. 0 B. Site Area to be cleared aridl y araded. ,000 sq. ft.. .................. ..... 5,000 - it :�4y1 acre .......... rtrtiai....rtirt.....i#.....rai.t.. li i s Y.. ri i t i.. 4 l a li 6... i i4 i i o Iacres•.,..ai..+C.hFi.tttrr,.rtt.•rtih.it.t.,ii#.....44..tt.*.ii. ...i,a#..� •.,haiai++li iia.il,#ai. uantit of ou#ender fill on site: 00 cubic yards .................... i**....+lFi..t. .i..............ir.....,rii...*!lirr.i o— 5,000 cubic yard,i,i....t,lii.ttt.ii�ii..r,■ii.,r!■4iY,rii••it*Fiaiaaii.iiiirrrrr,4 ,goo — 10,000 cubic yards ... 10 0,000 f�AJr000 cubic ,i Fa...,iii...sir.....,is...+ �y fJ�`�'y' Lf�+`f'�'[cubic ubicyards....................i......l. r. .....rt:.....h........... 2 V, 0 u bi yards ........ ir..aat+rfi..FF I i r Y.,siiit.rilri.. ihat.. ..rli+#...... 0 ..,+ir4. D. Runoff potential of predominant soils Nature Resources Conservation Service : Hydrologic soil group A ................................... •,.-tom...+t.... .h......�.......#......ii...i.. Hdroiog{o soil group ., ... Y ....,..1 •,r....rtrrti..••!il....,sii...r+1l+••••,ih... Hydrologic soil groupC .............iiii..i..i#.lFii...,,haY•.,iiiii.*lirii.,,iihii...i+ Hydrologic soil group +Fit.t.irtii.t.r44.....li.ti.,a..... if ...............t.t....a. E. Erosion Potential of predorriinant soils Uri"fled Classification Sstem . W, GP, SW, P soils ........... ' •,.iiii.■a, ■Y�ii,li#.•,•rtf.i... F.. ........... l+ Duai classifications W-GM, GP -GM, GW-GC, GP -GC, ' • +- ! = ij +7 - /' , P; , P-SC % ............ii.i.....i.. ■ 1, , MP ••• L, CL, M H , H soils ..,....iiFa..ri.ii.........trrii.... ,• 40 F. Surfaceyy or Groundwater enterin site Wentified and inter dT Yes ...... ,r.i.i......+i. ....+......li....rir.... ... {� •#rt.+t4....t,fa•...ffil.t.iaaii..+l.ri....riii �} .........sii..rhi......+.+.**ri...,ri4i.ttilsirt..r,iai... i#i#*i• „ �t••,ii Fa ..rriiir,.l.. i#,ii.ri G. Depth of out or bey ht of fill > 10 feet: Yes �+.... ..... ...... _.............r....i..........tt.......t++.....,F�i...,irr..,lrii..+!l....., No. ........ .+.•.•i4.ii4..iia,h...t..ih......ti.t+.+.,h.....riFt..f*tits fi,iYYMs. ,,7aai..,a,aY...h,ilat. a H. Clearing and c1radinq will occur in the wet season October 1 -- Ma 1 :.s o Illo .... ...i ..t...... ...... .....i.......4...... ....i.,l.....,!#.... .. ...10 air...,Fi.....a-.t.........+. TOTAL POINTS .t... r....i.a............rti.....F......i*t.t..4.... ..—........... 1 If no surface or groundwater eaters site, re i 0 points. g P APPENDIX — Site Plan with all applicable information (Minimum Size II x17 at a legible scale) k to, Table 4.1.1 Source Control BMP's by SWPPP Element Bf.#P or Element foams E let ni #I Preserve E le rr*nt #Z Estabfistr Element#5 Elem nt#6 Ei�rrent#'3 Uerment##1 Elerrwent#12 E lernent #13 Construction 5tahife Protecf Canlxal f.Fairstain Ixlanage Ifi�e Protect Love CteaFilionl3ark Clearin Acee Soils Slopes Pollutants BMPi Project IrnpacI BLIPC101: PreservingfiafuralVegetation V C1 velo rw 8MP C1{?Z: Buffer Zanes BMP C 103: High Visibifty Plastic or Matal - fence BMP C105: Stabilized Construction Entrance f Exit OUPCIM' U1I ael Wash B f I P C107: C0n5tiuction RoarlrParkeig Area StabUization 81-1P C 170: Temporary and Perrnanenl Seeding BF.1PC121: Maichbig BMP C122: Nets and Blankets BMP C123: Plastic Cwering BMP C124; Sodding , BIAP C125: Topsoiii;ng I Cumpx}sting BMP C126: Polyacrylawiide foi Soil Er05iots Protection V f3fiP C130: Stuface Roughening BMP C131: GFad lea; Terraces BMP Cl&- Dust Control BLIP C150: Materials On hand BF-f€' C151: C011crete Handling BF.1PC152: aamcutting and Surfacing Pollution Prevention f3RIP C153: Maferial DeIvM. Stwage and Containment F300 C 15d: Concrete ftshoux Area J BRIPC160: Cei%6Dd Erosion and Sedknent Control; Lead EBMPC1$2: Scheduling Version Date: October 7. 2019 Previous Version Date: February 20, 201 - ��.--- -- --- Table 4. •1 Runoff Conveyance and Treatment BMP's by SWPPP Element s at Ikln,- n: niergl 1rtisE�II Elel Eltr ��rMlgIrMt1t� Elle*r+nx 3 [il�r rrt Narr� Contfol pralwc# Pfut.�U; sljibll o �rc�i Contra�I De Pfw.r.ct LAW l~Jv r S�cl � + 1f S�op�s ,rain I Iar Cl t� k Impact .r.,-tr t rr wittetlry Ind et! GMT* C ps h1lPirmpl a Dike+ and Sra+alip , BM P C202; Cl'ranneI Ll *pq BUR C2C3: Wawr Qifw. .-am— �a1�� �lMP CA& :8UbsUewe B AP CM., Leve1 rre-id4m HMP c2Ul: Check urns Rhip G7cs* T rowwwar Sm t71� :sac ri m Lnnawd Cheirk l` ern) LIMP e2w. Outlet pratecl chi RNIP Cam: StOFrr 13FiLln 111IQt P,iril+ c Wan HMP G231: Lhwu h Barrier 13MP C232, Orelvrk PdWr Hmmi I A P C233; SO Fa n-r. c vof BIAP C2341 1 +1.A� 1 Ve am Cam: n" $NIP C 6: Vegitallvn FlltMIon 'REAP C2a0: ScdkriantTrap , I3MR C 1: T rrrpa�rr 5 snl i i fAP C29W CM51rLclian Sls�s� t CIierric of Ttsa#n wt B P C251: Casw�ru�lvrr 1Iltgnume rt F Fll«r often BMP C2I in n ISM" El C 20: PH Contra! for N101 y pjq %%ftr r Version Date: October 7, 2019 Previous Version Date: February 20, 2019 �� we ..r Se