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HomeMy WebLinkAboutBLD2015-00083 - 05 STORMWATER i • SoN .% DEPARTMENT OF COMMUNITY DEVELOPMENT 6'l Sheridan Street,Port Townsend,WA 98368 Tel:3611.379.4450 j Fax:360.379.4455 Web:www.co.icffcrson.wa.us/communitvdevelopmcnt F-mail dcdraco.jefferson.wa.us 1N- STORMWATER CALCULATION WORKSHEET MLA# PROJECT/APPLICANT NAME: DETERMINING STORMWATER MANAGEMENT REQUIREMENTS:This stormwater calculation worksheet should be completed first to classify the proposal as "small," "medium," or "large." The size determines whether a Stormwater Site Plan is required in conjunction with a stand-alone stormwater management permit application,building permit application,or other land use approval application that involves stormwater review. The basic information will also be helpful for completing a Stormwater Site Plan, if required. �� PARCEL SIZE(I.E..SITE) Size of parcel L" yy55cres An acre contains 43,560 square feet. Multiply the acreage by this figure. Size of parcel in square feet 67(560 sq/ft Land-disturbing activity is any activity that results in movement of earth,or a change in the existing soil cover(both vegetative and non-vegetative)and/or the existing soil topography. Land disturbing activities include,but are not limited to clearing,grading,filling, excavation,and compaction associated with stabilization of structures and road construction. Native vegetation is vegetation comprised on plant species,other than noxious weeds,that are indigenous to the coastal region of the Pacific Northwest and which reasonably could have been expected to naturally occur on the site. Examples include species such as Douglas fir, western hemlock, western red cedar, alder, big-leaf maple, and vine maple; shrubs such as willow, elderberry, salmonberry,and salal;herbaceous plants such as sword fern,foam flower,and fireweed. LAND DISTURBING ACTIVITY,CONVERSION OF NATIVE VEGETATION,AND VOLUME OF CUT/FILL Calculate the total area to be cleared,graded,filled, Answer the following two questions related to excavated,and/or compacted for proposed development conversion of native vegetation: project. Include in this calculation the area to be cleared for: �a 0 0 Does the project convert' acres or more of Construction site for structures I sq/ft native vegetation to lawn or landscaped areas? Drainfield,septic tank,etc. 5 (S D O _ sq/ft Circle: Yes Well, utilities, etc. sq/ft Does the project convert 2 Ys acres or more of native vegetation to pasture? Driveway, parking, roads,etc. Soo sq/ft Circle: Yes Lawn, landscaping,etc. sq/ft Other compacted surface, etc. sq/ft Indicate Total Volumes of Proposed: Total Land Disturbance (t 00 sq/ft Cut / Fill (cu/yd) impervious surface is a hard surface that either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development. A hard surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to roof tops,walkways,patios,driveways,parking lots or storage areas,concrete or asphalt paving,gravel roads, packed earthen materials,and oiled,macadam or other surfaces which similarly impede the natural infiltration of stormwater. stormwater calc worksheet-REV.10/202014 1 • • STORMWATER CALULATIONS-IMPERVIOUS SURFACE NEW EXISTING -/ Structures(all roof area) 1 5 3 sq/ft Structures(all roof area) sq/ft 7 Sidewalks 42) sq/ft Sidewalks sq/ft Patios sq/ft Patios sq/ft Solid Decks sq/ft Solid Decks C sq/ft (without infiltration below) (without infiltration below) Driveway, parking, roads, etc 1 7 7 sq/ft Driveway, parking, roads, etc sq/ft Other sq/ft Other O sq/ft Total New 2./42 2. 5J sq/ft Total Existing 0 sglft TOTAL NEW+TOTAL EXISTING" 2f6 sglk *This amount will be used to check total lot coverage. The following questions will help determine whether the proposed project is considered development or redevelopment. DEVELOPMENT v.REDEVELOPMENT Divide the total existing impervious surface above by the size of the parcel and convert to a percentage: 4 % Does the site have 35%or more of existing impervious surface? Circle: Yes 0 No El FURTHER INSTRUCTIONS: If the answer is yes,the proposal is considered redevelopment and the attached Figure 2 should be used to determine the applicable Minimum Requirements. If the answer is no, the proposal is considered new development and the attached Figure 1 should be used. At this juncture, the applicant should refer to the applicable Flow Chart to determine the Minimum Requirements for stormwater management. DCD staff will help verify the classification of the project and the application requirements. For proponents of "small" projects who must comply only with Minimum Requirement #2—Construction Stormwater Pollution Prevention—an additional submittal is not required. The proponent is responsible for employing the 12 Elements to control erosion and prevent sediment and other pollutants from leaving the site during the construction phase of the project. Pick up the Construction Stormwater Pollution Prevention (SWPP) Best Management Practices (BMPs) Packet. Proponents of "medium" projects—those that must meet only Minimum Requirements#1 through#5—and for"large" projects—those that must meet all 10 Minimum Requirements—are required to submit a Stormwater Site Plaq. DCD has prepared a submittal template of a Stormwater Site Plan, principally for rural residential projects. Complete the template in the Stormwater Site Plan Instructions and Submittal Template or prepare a Stormwater Site Plan using the step-by-step guidance in the Storm water Management Manual. APPLICANT SIGNATURE By signing the Stormwater Calculation Worksheet,I as the applicant/owner attest that the information provided herein is true and correct to the best of my knowledge. I also certify that this application is being made with the full knowledge and consent of all owners of the affected property. �,4414,t1 /P4i4' • , - u 3 - 17 -2,e1 (LANDOWN ER OR AUTHORIZED REPRESENT E SIGNATURE) (DATE) n4'f11 ppm �i t • T S _rf°rry"', .y.,�`,3r .k, .:,'•moi «: 4"I tot. `. " 'N t�Vt3fi. ,,`' } `ri ! `Sas= ,,.{StoomwatoiteptalY�'..Yom: ,3, „3 °iit 1. r .?_e3jr stormwater calc worksheet—REV.102012014 2 • • FIGURE 1 : NEW DEVELOPMENT Start Here Does the site have Yes See Redevelopment 35% or more of Minimum existing impervious Requirements and coverage? Flow Chart (Figure 2) No Does the project convert 3/4 acres or more of native • vegetation to lawn or Does the project add No landscaped areas,or 5,000 square feet or convert 2.5 acres or more more of new of native vegetation to impervious surfaces? pasture? Yes Yes Does the project have 2,000 square feet or "LARGE"PROJECT more of new, replaced, All Minimum Requirements or new plus replaced apply to the new impervious impervious surfaces? surfaces and converted pervious surfaces. es No • "MEDIUM" PROJECT Does the project have Minimum Requirements #1 land-disturbing L??"%q v7 through#5 apply to the new activities of 7,000 and replaced impervious Yes square feet or more? surfaces and the land disturbed. No "SMALL" PROJECT See Minimum Requirement#2, Construction Stormwater Pollution Prevention Based on Fig.2.2 from 2001 Ecology Storm water Management Manual for Western Washington • • "O r a°&. JEFFERSON COUNTY ,.4 DEPARTMENT OF COMMUNITY DEVELOPMENT 621 Sheridan Street • Port Townsend • Washington 98368 .y� �O$ (360) 379-4450 -- (360) 379-4451 Fax TNG http://www.co.jefferson.wa.us/commdevelopment/ Stormwater Site Plan Instructions and Submittal Template "Medium" and "Large" Projects [Includes Construction Stormwater Pollution Prevention Plan (SWPPP)and Permanent Stormwater Control Plan] The submittal template for a Stormwater Site Plan has been developed from information presented in the Department of Ecology 2013 Stormwater Management Manual for Western Washington (Manual), which is the set of stormwater management standards for new development and redevelopment in Jefferson County. The Stormwater Site Plan, Minimum Requirement #1 in the Manual, is the comprehensive report containing all of the technical information and analysis necessary to evaluate a proposed new development or redevelopment for compliance with stormwater requirements. A Stormwater Site Plan is required for all "medium" and "large" projects. (For background information, refer to the Stormwater Management Information Sheet.) The Stormwater Site Plan includes a Construction Stormwater Pollution Prevention Plan (SWPPP — Minimum Requirement#2) that addresses sediment and erosion control during construction and a Permanent Stormwater Control Plan that addresses stormwater on the project site in its developed condition through dispersion, infiltration, or, if necessary,flow control and/or treatment facilities. The steps for preparing and the content of a Stormwater Site Plan are summarized below and more fully described in Chapter 3 of Volume I of the Manual. The attached submittal template is intended to be a format applicable to typical rural residential construction. For these cases, completion and submittal of the template results in a complete land use application. THE TWO MAIN COMPONENTS OF A STORMWATER SITE PLAN I. Construction Stormwater Pollution Prevention Plan A Construction Stormwater Pollution Prevention Plan (SWPPP) is a document that describes the potential for pollution problems on a construction project and which explains and illustrates the measures to be taken to control these problems. The basis for requiring a SWPPP, the twelve elements required to be in a SWPPP, the suggested step-by step procedure to follow, and the suggested Best Management Practices (BMPs) to follow, are all described in Volume II of the Manual. A SWPPP consists of two sections, a narrative and the drawings. A description of the contents of the narrative and the drawings sections, and checklists for each of these sections, are in Section 3.3 of Volume II. For typical rural residential projects, DCD provides a Construction Stormwater Pollution Prevention (SWPP) Best Management Practices (BMPs) Packet to assist with the preparation of the Construction SWPPP. II. Permanent Stormwater Control Plan A Permanent Stormwater Control Plan is a document that describes the basis for, and the means of implementing, permanent Best Management Practices (BMPs)for flow control and treatment facilities after the project is completed. The content of a Permanent Stormwater Control Plan is described in Section 3.1.5 of Volume I of the Manual. The permanent BMPs and facilities for flow control and treatment are described in Volumes III, IV, and V of the Manual. The submittal template is intended for rural residential projects that can fully disperse or infiltrate stormwater. The template may not be appropriate or sufficient for applications involving larger or more complex projects. stormweter site plan template doc—rev.41282014 1 • • INSTRUCTIONS To prepare a Stormwater Site Plan, follow the steps outlined below, complete the Stormwater Site Plan template, sign and submit together with the Master Land Use Application (MLA). This information may also be provided on other diagrams, plans, studies, or attachments submitted with the project application. If so, please indicate such on this supplemental permit application. As the template is designed mostly for rural residential development, it may not be as useful for a larger project as an independently prepared Stormwater Site Plan. For any particular project, the Administrator may waive specific submittal requirements determined to be unnecessary for review of the application. Note: Prior to filling out the submittal template, read through these steps for preparing a Stormwater Site Plan. Preliminary or draft versions of the individual components may be helpful in the case that redesigning an original layout would result in a proposal that has less environmental impacts and is significantly simpler in terms of meeting stormwater requirements. For example, if the proposal can utilize the "full dispersion"BMP (T5.30 in the Manual), there is no need to provide for flow control or flow treatment on the site. For more information on the easiest way to meet stormwater requirements, refer to the "Low Impact Development"Information Sheet. BMPs used during the construction phase and that are included in the Construction SWPPP may also be useful as elements of the Permanent Stormwater Control Plan. STEP 1: COLLECT AND ANALYZE INFORMATION ON EXISTING CONDITIONS Collect and review information on existing site conditions, including topography, drainage patterns, soils, ground cover, critical areas, adjacent areas, existing development, existing stormwater facilities. The Jefferson County website provides an Internet Map Server (IMS)function(http:/lwww.co.jefferson.wa.us). If available, a Development Review Division(DRD)planner may be able to assist you in collecting this information. Analyze the information to determine site limitations, including: • Areas with high potential for erosion and sediment deposition(based on soil properties,slope,etc.); • Locations of sensitive and critical areas (e.g., vegetative buffers,wetlands, steep slopes, floodplains, geologically hazardous areas,streams,susceptible aquifer recharge areas,etc.);and • The natural receiving waters to which the stormwater runoff either directly or eventually discharges. This information will be useful in site design and in the completion of the Permanent Stormwater Control Plan and Construction SWPPP. STEP 2: PREPARE PRELIMINARY DEVELOPMENT LAYOUT Based upon the analysis of existing site conditions,locate the buildings,driveways,roads,parking lots,and landscaping features for the proposed development. Consider the following points when laying out the site: • Fit development to the terrain to minimize land disturbance; confine construction activities to the least area necessary and away from critical areas; • Preserve areas with natural vegetation(especially forested areas)as much as possible; • On sites with a mix of soil types, locate impervious areas over less permeable soil (e.g., till) and try to restrict development over more porous soils(e.g., outwash); • Cluster buildings together; • Minimize impervious areas; and • Maintain and utilize the natural drainage patterns. The preliminary development layout will assist in determining threshold discharge areas for calculating whether size thresholds under Minimum Requirements#6, #7, and#8 (for"large" projects) are exceeded and as a basis for the drawings and maps required for the Stormwater Site Plan. stonnwater site plan template doe-rev.4282014 2 s • STEP 3: PERFORM AN OFF-SITE ANALYSIS This step is for "large" projects (i.e., adding 5,000 square feet or more of new impervious surface, converting % acres of pervious surfaces to lawn or landscaped areas, or converting 2 '/z acres of forested area to pasture)at the discretion of the UDC Administrator. See Volume I, Section 2.6.2 for more information. STEP 4: REVIEW THE APPLICABLE MINIMUM REQUIREMENTS The Stormwater Calculation Worksheet is a required submittal for all development and redevelopment land use applications. Completing the Worksheet helps determine the broad category of the proposal—"small," "medium," or "large" project—and the applicable Minimum Requirements. "Small" projects need to meet Minimum Requirement#2 only. "Medium" projects need to meet Minimum Requirements#1 through #5. "Large" projects need to meet all the Minimum Requirements,#1 through#9. The Minimum Requirements are as follows: 1. Preparation of Stormwater Site Plans(Chapter 3 of Manual) 6. Runoff Treatment 2. Construction Stormwater Pollution Prevention 7. Flow Control 3. Source Control of Pollution 8. Wetlands Protection 4. Preservation of Natural Drainage Systems and Outfalls 5. On-site Stormwater Management 9. Operation and Maintenance The Manual provides descriptions and instructions in Volume I,Chapter 2. Information sheets, application materials,and DRD planners can help describe the Minimum Requirements to applicants. Note: "Large"projects, as part of meeting Minimum Requirements #6 – Runoff Treatment – and #7 – Flow Control, are compared to Volume 1, Chapter 2 in the Manual to determine whether on-site stormwater management BMPs are sufficient or treatment facilities or flow control facilities are required. The flow control determination may necessitate use of the Western Washington Hydrology Model managed by the Department of Ecology. Consult Sections 2.5.6 and 2.5.7 of Volume 1, Chapter 2 of the Manual for more information. Again, the easiest way to meet stormwater requirements is to design the project so that natural drainage is preserved, impervious surface is limited, and full dispersion (BMP T5.30) is implemented. By using"low impact development" techniques in the site design, the need for treatment and flow control facilities is eliminated, simplifying preparation of the Stormwater Site Plan and often the site construction process itself. For more information on these techniques,consult the"Low Impact Development"Information Sheet. STEP 5: PREPARE A PERMANENT STORMWATER CONTROL PLAN Select stormwater control BMPs and facilities that will serve the project site in its developed condition. The selection process is presented in Volume I, Chapter 4. After consideration is given to how selected BMPs and facilities fit within and serve the entire preliminary development layout, the designer may want to reconsider the site layout to reduce the need for construction of facilities or the size of the facilities by reducing the amount of impervious surfaces created and increasing the areas to be left undisturbed. The Permanent Stormwater Control Plan should contain the following sections(Section 3.1.5 of Volume I,Chapter 3): • Existing Site Hydrology(i.e.,the behavior of water on the site—above,below, and on the ground) • Developed Site Hydrology (special requirements for projects and threshold discharge areas within projects that requirement treatment and flow facilities) • Performance Standards and Goals • Flow Control System • Water Quality System • Conveyance System Analysis and Design Essentially, in terms of site hydrology, the developed condition of the site should match the pre-developed condition, with is forested land cover (unless reasonable, historic information is provided that indicates the site was prairie prior to settlement). For "large" projects, totals of impervious surfaces, pollution-generating impervious surfaces, and pollution generating pervious surfaces must be tabulated for each threshold discharge area for which on-site BMPs are the sole stormwater management approach. stormwater rite plan templale.dac-rev.41282014 3 • • STEP 6: PREPARE A CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (SWPPP) The Construction SWPPP for projects adding or replacing 2,000 square feet of impervious surface or more or clearing 7,000 square feet or more (i.e., "medium" or"large" projects), must contain sufficient information to demonstrate to the UDC Administrator that the potential pollution problems have been adequately addressed for the proposed project. An adequate Construction SWPPP includes a narrative and drawings. The narrative is a written statement to explain and justify the pollution prevention decisions made for a particular project. The narrative contains concise information concerning existing site conditions, construction schedules, and other pertinent items that are not contained on the drawings. The drawings and notes describe where and when the various BMPs should be installed, the performance the BMPs are expected to achieve, and actions to be taken if the performance goals are not achieved. There are 12 Elements that must be considered in the development of a Construction SWPPP, unless site conditions render that element unnecessary and the exemption from that element is clearly justified in the narrative. The 12 Elements cover the general water quality protection strategies for limiting site impacts during construction and are described in detail in Section 2.5.2, Volume I of the Manual. The 12 Elements of Minimum Requirement#2,Construction Stormwater Pollution Prevention,are: 1. Mark Clearing Limits 6. Protect Slopes 11. Maintain BMPs 2. Establish Construction Access 7. Protect Drain Inlets 12. Manage the Project 3. Control Flow Rates 8. Stabilize Channels and Outlets 13. Protect Low Impact Development 4. Install Sediment Controls 9. Control Pollutants BMP's 5. Stabilize Soils 10. Control De-watering For ease of use, the Stormwater Site Plan submittal template below includes a section that lists the 12 Elements and provides the opportunity to include sufficient information for rural residential and other relatively simple Construction SWPPPs. For more complex projects,a separate narrative and set of plans may be preferred or required. Volume II of the Manual is dedicated to Construction Stormwater Pollution Prevention. A step-by-step BMP selection process and a complete description of the BMPs applicable to each element is provided in Chapters 3 and 4. Additionally, DCD provides a Construction Stormwater Pollution Prevention (SWPP) Best Management Practices (BMPs) Packet that summarizes the 12 Elements and excerpts from the Manual sample sediment and erosion control measures for typical rural residential development. The Packet should prove useful for completing the Construction SWPPP component of the submittal template. On construction sites that infiltrate all stormwater runoff,the primary consideration in the preparation of the Construction SWPPP is the protection of the infiltration facilities from fine sediments during the construction phase and protection of ground water from other pollutants. On construction sites that discharge to surface water, the primary consideration in the preparation of the Construction SWPPP is compliance with the State Water Quality Standards. The step-by-step procedure outlined in Volume II, Section 3.2 is recommended for the development of these Construction SWPPPs. STEP 7: COMPLETE THE STORMWATER SITE PLAN The Stormwater Site Plan encompasses the entire submittal to Jefferson County in conjunction with a land use or building permit application. The following documents or sections should be included: • Project Overview • Existing Conditions Summary • Off-site Analysis Report(if required;usually for"large"projects) • Permanent Stormwater Control Plan • Special Reports and Studies(such as soil testing,wetland delineation,etc., if applicable) • Other Permits(approvals required by other regulatory agencies that include stormwater management conditions) • Operation and Maintenance Manual(for each flow control and treatment facility, if applicable) • Bond Quantities Worksheet (for performance bond or other financial guarantee for proper construction and operation of construction site BMPs and permanent drainage facilities, if required) The submittal template below is designed for rural residential and other relatively small or simple projects. For larger and more complex projects—particularly those that involve stormwater treatment and/or flow control—more information may be required and an independent Stormwater Site Plan may be the preferable submittal format. 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 applicant should review to check that these requirements are satisfied and that all information provided is true and correct prior to signing and submitting the Stormwater Site Plan. (The signature box appears at the end of the submittal template.) 4 stormwater site pan template.doc-rev.4282014 • • STORMWATER SITE PLAN SUBMITTAL TEMPLATE MLA# Project/Applicant Name: Habitat for Humanity— Brookside Lot 6 PROJECT OVERVIEW 1. Describe the proposed developed conditions of the site. Indicate position and relative size of proposed improvements on the site map. The site currently is undelveoped land with native grasses and blackberry bushes. The site is a rectangle running East- West with Brookside street r.o.w. along the East property line. Chimacum Creek and a Community owned space is on the Western third, the septic fields in the middle, and a new single family home(1,432 s.f. lot coverage) with two car parking spaces and driveway will be built on the Eastern third. EXISTING CONDITIONS SUMMARY 2. Describe the existing topography. Indicate contours on the site map. The property is relatively level, sloping slightly down from the East to the West. There is a somewhat steeper slope from Brookside street to approximately 20' into the property. 3. Describe the existing vegetation. Indicate native vegetation areas on the site map. The site is covered with grasses and blackberry bushes. 4. Describe the existing soils. Indicate soil type on the site map. Soils are Casey silt loam with gravelly sandy loam below. 5. Describe the existing site hydrology (i.e. drainage; behavior of water on the site—above, below and on the ground). Indicate existing stormwater drainage to and from the site on the site map. Depict separate drainage basins on the site map, if applicable, and indicate acreage of each. Water seems to sink easily into the top layers of soil and retain there to some extent. Below grade, water flows Chimacum creek. 6. Describe any excess levels of noise generated by the proposed use of activity: There are no excess levels of noise other than typical residential usage. 7. Describe significant geographic features and critical areas (i.e., environmentally sensitive areas such as wetlands, streams, steep slopes, etc.)on the site. Indicate location on the site map. Chimacum Creek runs across the property on the West end. 8. Describe the general vicinity of the site, including adjacent land uses and structures, utilities, roads, and sensitive/critical areas(streams, wetland, lakes, steep slopes, etc.) The land use to the north is RR 1:5, to the east RR 1:20,the South AL 1:20 and to the west RR 1:5. The site is served by a gravel private 2-lane road, Brookside Street. The site is served by Jefferson County PUD#1 water. Chimacum Creek runs across the property on the West end. PERMANENT STORMWATER CONTROL PLAN 9. Describe the developed site hydrology, as proposed. Indicate whether stormwater will be fully dispersed (i.e., per BMP T5.30 in the Manual) or, if not, what types of stormwater flow control will be utilized for the site or specific threshold discharge areas with in the site. Locate these facilities on the site plan and differentiate proposed facilities from existing facilities. Roof runoff will be diverted to an existing drainage ditch on the north side of the property through tightlines. The driveway runoff will flow onto the property and through native vegetation. 1 of 4 10. If the project requires the use of stormwater treatment facilities, describe the types of stormwater treatment facilities proposed for use on the site. Locate these facilities on the site plan and differentiate proposed facilities from existing facilities. [This is normally for"large" projects or projects that involve the potential for dispersion of contaminants.] N/A 11. Describe the performance goals and standards applicable to the project. The performance goals are to infiltrate stormwater on site and prevent pollution from reaching the adjacent creek. 12. Describe the flow control system. hof runoff: tightlines to and existing drainage ditch. Driveway runoff: sheet flow to dispersion swale. 13. Describe the water quality system. N/A 14. Describe the conveyance system analysis and design. N/A 15. Describe the source of fill material, physical characteristics of fill material and deposition of excess material. Fill material will consist of native soil removed from excavation for house footings. This material will be spread in areas of the site cleared for septic system. 16. Proposed method of placement and compaction consistent with the applicable standards on Appendix Chapter 33 of the Uniform Building code. N/A 17. Describe the proposed surfacing material. The driveway will be gravel. 18. Describe methods for restoration of the site. Re-use and spread native soil on disturbed areas, encourage the growth of native vegetation and remove non-native and invasive weeds. 19. An Operation and Maintenance Manual is required for each flow control and treatment facility. [This is normally required for"large" projects only and only those for which facilities are required to control flow or treat runoff.] If included, list the Manuals here. N/A 20. List here and include any special reports or studies conducted to prepare the Stormwater Site Plan. None 21. List other necessary permits and approvals as required by other regulatory agencies. If those permits or approvals include conditions that affect the drainage plan or contain more restrictive drainage-related requirements, describe those conditions or restrictions here. Building permit. Septic Permit approved. 2 of 4 • S CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (SWPPP) SECTION 1 — CONSTRUCTION SWPPP NARRATIVE 1. Construction Stormwater Pollution Plan Elements. Describe how each of the Construction SWPPP elements has been or will be addressed. Identify the type and location of BMPs used to satisfy the required element. If an element is not applicable to the proposal,justify in writing. Descriptions of the 12 Elements are found at Volume II Section 3.2.3 of the Manual (beginning on page 3-7). 12 Required Elements—Construction SWPPP 1. Mark Clearing Limits. Prior to construction, limits of areas to be cleared will be delineated with stakes and plastic fencing, per BMP C103. Trees to be preserved will be flagged per BMP .C101 2. Establish Construction Access. Construction entrance at existing driveway will be established per BMP C105 3. Control Flow Rates. N/A Slope on this site is shallow enough that natural flow will be very minimal. 4. Install Sediment Controls. N/A The site is level. 5. Stabilize Soils Stockpiled soil, if any, will be protected with plastic sheeting per BMP C123. 6. Protect Slopes. N/A No slopes 3:1 or steeper location on site. 7. Protect Drain Inlets. N/A No drain inlets on site. 8. Stabilize Channels and Outlets. Drainage ditch is existing and stable. 9. Control Pollutants. Pollutants will be controlled at their source. No vehicle maintenance will be done on site. Concrete truck cleaning will be done so that wastewater stays on site,per BMP C151. 10 Control De-Watering (the act of pumping groundwater or stormwater away from an active construction site). Excavation de-watering, if needed, will disperse water on site and be allowed to filter through native soil and vegetation. 11. Maintain Best Management Practices (BMPs). Construction entrance, straw bales, plastic sheeting and construction limit fencing will be inspected and maintained on a monthly basis. These items will be removed no later than 30 days after completion of construction project. 12. Manage the Project. See information provided on Phasing and Construction Schedule. 3 of 4 • • 2. Adjacent Areas. a. Description of the adjacent areas that may be affected by site disturbance (e.g., streams, lakes, wetlands, residential areas, roads). All runoff will be filtered before it reaches any adjacent areas. b. Description of the downstream drainage path leading from the site to the receiving body of water (minimum distance of 400 yards.) The drainage path is to drainage ditch on the North side of the property. Which leads to Chimacum creek. All septic and buildings are beyond the 100' creek buffer. 3. Environmentally Sensitive Areas. a. Description of environmentally sensitive areas that are on or adjacent to the site. Chimacum Creek runs across the property on the West end. b. Description of special requirements for working in or near environmentally sensitive areas. All work will be performed outside of the 100' creek buffer zone. 4. Erosion Problem Areas. Description of potential erosion problems on site in the context of the characteristics of the on-site soils(e.g., erodibility, settleabliity, permeability, depth, texture, soil structure). N/A No slopes steep enough to pose erosion problems. 5. Construction Phasing. a. Construction sequence. (1) gravel driveway (2) single family residence b. Construction phasing (if proposed) N/A 6. Construction Schedule. West season is October 1 through April 30 (page 2-21 of the Manual). I. Provide a proposed construction schedule. April 2015: grading and foundation May 2015 — September 2015: framing, enclosing and finishing II. Wet Season Construction Activities. a. Proposed wet season construction activities. None, project will be completed by October. b. Proposed wet season construction activities for environmentally sensitive areas. None, project will be completed by October. 7. Financial/Ownership Responsibilities. a. Identify the property owner responsible for the initiation of bonds and/or other financial securities. Habitat for Humanity of East Jefferson County b. Describe bonds and/or other evidence of financial responsibility of liability associated with erosion and sedimentation impacts. N/A 8. Engineering Calculations. Provide Design Calculations on a separate sheet for the following, if applicable. a. Sediment Ponds/Traps. N/A b. Diversions. N/A c. Waterways. N/A d. Runoff/Stormwater Detention Calculations N/A 4 of 4 • • SECTION II—EROSION AND SEDIMENT CONTROL PLAN Sediment and erosion control measures may be depicted on the master land use application plot plan, a stormwater site plan, and/or a separate Construction SWPPP site plan. This is a checklist to ensure that the following are depicted on a site plan: 1. General. a. Vicinity Map b. Jefferson County Approval Block c. Erosion and Sediment Control Notes 2. Site Plan. a. Legal description of subject property. b. North arrow. c. Indicate boundaries of existing vegetation(e.g.,tree lines, pasture areas,etc.). d. Identify and label areas of potential erosion problems. e. Identify FEMA base flood boundaries and Shoreline Management boundaries(if applicable). f. Show existing and proposed contours. g. Indicate drainage basins and direction of flow for individual drainage areas. h. Label final grade contours and identify developed condition drainage basins. i. Delineate areas that are to be cleared and graded. j. Show all cut and fill slopes indicating top and bottom of slope catch lines. 3. Conveyance Systems. a. Designate locations for swales, interceptor trenches, or ditches. b. Show all temporary and permanent drainage pipes,ditches,or cut-off trenches required for erosion&sediment control. c. Provide minimum slope and cover for all temporary pipes or call out pipe inverts. d. Shows grades,dimensions, and direction of flow in all ditches,swales,culverts and pipes. e. Provide details for bypassing off-site runoff around disturbed areas. f. Indicate locations and outlets of any dewatering systems. 4. Location of Detention Best Management Practices(BMPs). Identify location of detention BMPs. 5. Erosion and Sediment Control Facilities. a. Show the locations of sediment trap(s), pond(s), pipes and structures. b. Dimension pond berm widths and inside and outside pond slopes. c. Indicate the trap/pond storage required and the depth, length,and width dimensions. d. Provide typical section views through pond and outlet structure. e. Provide typical details of gravel cone and standpipe, and/or other filtering devices. f. Detail stabilization techniques for outlet/inlet. g. Detail control/restrictor device location and details. h. Specify mulch and/or recommended cover of berms and slopes. i. Provide rock specifications and detail for rock check dam(s), if applicable. j. Specify spacing for rock check dams as required. k. Provide front and side sections of typical rock check dams. I. Indicate the locations and provide details and specifications for silt fabric. m. Locate the construction entrance and provide a detail. 6. Detailed Drawings. Any structural practices used that are not referenced in the Ecology Manual should be explained and illustrated with detailed drawings. 7. Other Pollutant BMPs. Indicate on the site plan the locations of BMPs to be used for the control of pollutants other than sediment(e.g.,concrete wash water). 8. Monitoring Locations. Indicate on the site plan the water quality sampling locations to be used for monitoring water quality on the construction site. Sampling stations should be located upstream and downstream of the project site. stormwater site plan Iemplate.doc—rev.4/282014 11 • • Stormwater Site Plan Changes If the designer wishes to make changes or revisions to the originally approved Stormwater Site Plan, the proposed revisions shall be submitted to DCD prior to construction. The submittal shall include substitute pages that include all proposed changes, revised drawings showing any structural changes, and any other supporting information that explains and supports the reason for the change. Final Corrected Plan Submittal If the project included construction of conveyance systems,treatment facilities, flow control facilities,or structural source control BMPs (not standard on-site stormwater management BMPs),the applicant shall submit a final corrected plan ("as-builts")when the project is completed. These should be engineering drawings (stamped by a licensed civil engineer) that accurately represent the project as constructed. APPLICANT SIGNATURE By signing the Construction SWPPP worksheet, I as the applicant/owner attest that the information provided herein is true and correct to the best of my knowledge. I also certify that this application is being made with the full knowledge and consent of all owners of the affected property. 3-(3-ZO (S (LANDO ER OR AUTHORIZED RE SIGNATURE) (DATE) THIS SPACE MAY BE USED FOR ADDITIONAL NOTES, IF NEEDED: stormwater site plan templateAoc—rev.4282014 12 0 0 ��oN DEPARTMENT OF COMMUNITY DEVELOPMENT 4�' it O q, ' ' ', Cr� 621 Sheridan Street,Port Townsend.\y'A 90368 ��] W r a l � 944 1 V l i - Ie �ri0: (1 ; 'ax t? I. 45 Web:xtltw.co effersonwa.nsicommunttydcvelr mcnt �� r�'—" E-mail:dcda,cu.lcffcrs n.wa.us I ' 1 IS. ,N,C) MAR 1 7 2015 STORMWATER CALCULATION WORKSHEET ' ,-J. L.-'lm l l ,-e0raf;,',PT,'Dr.'r_L0PMENT _-, MLA tt PROJECT/APPLICANT NAME: DETERMINING STORMWATER MANAGEMENT REQUIREMENTS:This stormwater calculation worksheet should be completed first to classify the proposal as "small," "medium," or "large." The size determines whether a Stormwater Site Plan is required in conjunction with a stand-alone stormwater management permit application, building permit application,or other land use approval application that involves stormwater review. The basic information will also be helpful for completing a Stormwater Site Plan, if required. PARCEL SIZE(I.E.,SITE Size of parcel 1.41Ect55cres An acre contains 43,560 square feet. Multiply the acreage by this figure. Size of parcel in square feet 67 i 56 sq/ft Land-disturbing activity is any activity that results in movement of earth, or a change in the existing soil cover(both vegetative and non-vegetative)and/or the existing soil topography. Land disturbing activities include,but are not limited to clearing,grading,filling, excavation,and compaction associated with stabilization of structures and road construction. Native vegetation is vegetation comprised on plant species,other than noxious weeds, that are indigenous to the coastal region of the Pacific Northwest and which reasonably could have been expected to naturally occur on the site. Examples include species such as Douglas fir, western hemlock, western red cedar, alder, big-leaf maple, and vine maple; shrubs such as willow, elderberry, salmonberry,and salal;herbaceous plants such as sword fern,foam flower,and fireweed. LAND DISTURBING ACTIVITY,CONVERSION OF NATIVE VEGETATION.AND VOLUME OF CUT/FILL Calculate the total area to be cleared, graded,filled, Answer the following two questions related to excavated,and/or compacted for proposed development conversion of native vegetation: project. Include in this calculation the area to be cleared for: Z1500 Does the project convert%acres or more of Construction site for structures 2 1 500 sq/ft native vegetation to lawn or landscaped areas? Drainfield, septic tank,etc. 5 1500 sq/ft Circle: Yes ©o Well, utilities,etc. sq/ft Does the project convert 2%acres or more of native vegetation to pasture? Driveway,parking, roads,etc. $00 sq/ft Circle: Yes Lawn, landscaping,etc. sq/ft Other compacted surface,etc. sq/ft Indicate Total Volumes of Proposed: Total Land Disturbance 2 t 00 sq/ft Cut IS Fill (cu/yd) impervious surface is a hard surface that either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development. A hard surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to roof tops,walkways, patios,driveways, parking lots or storage areas, concrete or asphalt paving,gravel roads, packed earthen materials,and oiled,macadam or other surfaces which similarly impede the natural infiltration of stormwater. stormwater colt worksheet-REV.10/20/2014 1 • • STORMWATER CALULATIONS–IMPERVIOUS SURFACE NEW y 2 5EXISTING Structures(all roof area) 117 55 sq/ft Structures(all roof area) e) sq/ft Sidewalks TJ7 sq/ft Sidewalks O sq/ft Q/ Patios U sq/ft Patios 0 sq/ft Solid Decks " sq/ft Solid Decks O sq/ft (without infiltration below) (without infiltration below) Driveway, parking, roads, etc 17 '7 sq/ft Driveway, parking, roads,etc O sq/ft Other sq/ft Other 0 sq/ft Total New 2)62 5 sq/ft Total Existing 0 sq/ft / TOTAL NEW+TOTAL EXISTING* 2/62S C. sq/ft *This amount will be used to check total lot coverage. The following questions will help determine whether the proposed project is considered development or redevelopment. DEVELOPMENT v.REDEVELOPMENT Divide the total existing impervious surface above by the size of the parcel and convert to a percentage: O Does the site have 35%or more of existing impervious surface? Circle: Yes ❑ No El FURTHER INSTRUCTIONS: If the answer is yes,the proposal is considered redevelopment and the attached Figure 2 should be used to determine the applicable Minimum Requirements. If the answer is no, the proposal is considered new development and the attached Figure 1. should be used. At this juncture, the applicant should refer to the applicable Flow Chart to determine the Minimum Requirements for stormwater management. DCD staff will help verify the classification of the project and the application requirements. For proponents of "small" projects who must comply only with Minimum Requirement #2—Construction Stormwater Pollution Prevention—an additional submittal is not required. The proponent is responsible for employing the 12 Elements to control erosion and prevent sediment and other pollutants from leaving the site during the construction phase of the project. Pick up the Construction Stormwater Pollution Prevention (SWPP) Best Management Practices (BMPs) Packet. Proponents of "medium" projects—those that must meet only Minimum Requirements#1 through#5—and for"large" projects—those that must meet all 10 Minimum Requirements—are required to submit a Stormwater Site Plan. DCD has prepared a submittal template of a Stormwater Site Plan, principally for rural residential projects. Complete the template in the Stormwater Site Plan Instructions and Submittal Template or prepare a Stormwater Site Plan using the step-by-step guidance in the Storm water Management Manual. APPLICANT SIGNATURE By signing the Stormwater Calculation Worksheet,I as the applicant/owner attest that the information provided herein is true and correct to the best of my knowledge. I also certify that this application is being made with the full knowledge and consent of all owners of the affected property. (LANDO NER OR AUTHORIZED REPRESENT 4 E SIGNATURE) (DATE) stormwater Calc worksheet—REV.10/202014 2l 1 i • • FIGURE 1 : NEW DEVELOPMENT Start Here Does the site have Yes See Redevelopment 35%or more of Minimum existing impervious Requirements and coverage? Flow Chart (Figure 2) No) Does the project convert% acres or more of native • vegetation to lawn or Does the project add landscaped areas, or �- 5,000 square feet or convert 2.5 acres or more i ��1 more of new of native vegetation to impervious surfaces? pasture? i '; MAR 1 7 2015 I I u - -- - - - -- JEI[ERSOC COUNTY ' r'ntl,iUWITY Cant HENT Does the project have "LARGE" PROJECT 2,000 square feet or more of new,replaced, All Minimum Requirements or new plus replaced apply to the new impervious impervious surfaces? surfaces and converted pervious surfaces. es No • "MEDIUM"PROJECT Does the project have Minimum Requirements#1 land-disturbing • ►; -��rl-y�j- through#5 apply to the new Yes activities of 7,000 and replaced impervious square feet or more? surfaces and the land disturbed. No • "SMALL" PROJECT See Minimum Requirement#2, Construction Stormwater Pollution Prevention Based on Fig.2.2 from 2001 Ecology Stormwater Management Manual for Western Washington • • MI T rv, JEFFERSON COUNTY DEPARTMENT OF COMMUNITY DEVELOPMENT ' ' '' MAR 1 7 2015 621 Sheridan Street • Port Townsend •Washington 98368 - 4 (360) 379-4450 — (360) 379-4451 Fax i IN "�t2N http://www.co.jefferson.wa.us/commdevelopment/ _CMJ",IT/DPFLOPpgENT Stormwater Site Plan Instructions and Submittal Template "Medium" and "Large" Projects [Includes Construction Stormwater Pollution Prevention Plan(SWPPP)and Permanent Stormwater Control Plan] The submittal template for a Stormwater Site Plan has been developed from information presented in the Department of Ecology 2013 Stormwater Management Manual for Western Washington (Manual), which is the set of stormwater management standards for new development and redevelopment in Jefferson County. The Stormwater Site Plan, Minimum Requirement #1 in the Manual, is the comprehensive report containing all of the technical information and analysis necessary to evaluate a proposed new development or redevelopment for compliance with stormwater requirements. A Stormwater Site Plan is required for all "medium" and "large" projects. (For background information, refer to the Stormwater Management Information Sheet.) The Stormwater Site Plan includes a Construction Stormwater Pollution Prevention Plan (SWPPP — Minimum Requirement#2) that addresses sediment and erosion control during construction and a Permanent Stormwater Control Plan that addresses stormwater on the project site in its developed condition through dispersion, infiltration, or, if necessary,flow control and/or treatment facilities. The steps for preparing and the content of a Stormwater Site Plan are summarized below and more fully described in Chapter 3 of Volume I of the Manual. The attached submittal template is intended to be a format applicable to typical rural residential construction. For these cases, completion and submittal of the template results in a complete land use application. THE TWO MAIN COMPONENTS OF A STORMWATER SITE PLAN I. Construction Stormwater Pollution Prevention Plan A Construction Stormwater Pollution Prevention Plan (SWPPP) is a document that describes the potential for pollution problems on a construction project and which explains and illustrates the measures to be taken to control these problems. The basis for requiring a SWPPP, the twelve elements required to be in a SWPPP, the suggested step-by step procedure to follow, and the suggested Best Management Practices (BMPs) to follow, are all described in Volume II of the Manual. A SWPPP consists of two sections, a narrative and the drawings. A description of the contents of the narrative and the drawings sections, and checklists for each of these sections, are in Section 3.3 of Volume II. For typical rural residential projects, DCD provides a Construction Stormwater Pollution Prevention (SWPP) Best Management Practices(BMPs) Packet to assist with the preparation of the Construction SWPPP. II. Permanent Stormwater Control Plan A Permanent Stormwater Control Plan is a document that describes the basis for, and the means of implementing, permanent Best Management Practices(BMPs)for flow control and treatment facilities after the project is completed. The content of a Permanent Stormwater Control Plan is described in Section 3.1.5 of Volume I of the Manual. The permanent BMPs and facilities for flow control and treatment are described in Volumes III, IV, and V of the Manual. The submittal template is intended for rural residential projects that can fully disperse or infiltrate stormwater. The template may not be appropriate or sufficient for applications involving larger or more complex projects. stormwater site plan template,tloc-rev.4/282014 1 S 11,1 • INSTRUCTIONS l• • fian; 1 7 '?015 I To prepare a Stormwater Site Plan,follow the steps outlined below, complete the Stomlwater Site Plan template, sigiOld submit together with the Master Land Use Application (MLA). This information may also be provided on other-diagrams, plans, studies, or attachments submitted with the project application. If so, please indicate such on this 1 ntal. permit application. As the template is designed mostly for rural residential development, it ma r ncit-be- s 'e #er a' larger project as an independently prepared Stormwater Site Plan. For any particular project, the Administrator may waive specific submittal requirements determined to be unnecessary for review of the application. Note: Prior to filling out the submittal template, read through these steps for preparing a Stormwater Site Plan. Preliminary or draft versions of the individual components may be helpful in the case that redesigning an original layout would result in a proposal that has less environmental impacts and is significantly simpler in terms of meeting stormwater requirements. For example, if the proposal can utilize the "full dispersion"BMP (T5.30 in the Manual), there is no need to provide for flow control or flow treatment on the site. For more information on the easiest way to meet stormwater requirements, refer to the "Low Impact Development"Information Sheet. BMPs used during the construction phase and that are included in the Construction SWPPP may also be useful as elements of the Permanent Storm water Control Plan. STEP 1: COLLECT AND ANALYZE INFORMATION ON EXISTING CONDITIONS Collect and review information on existing site conditions, including topography, drainage patterns, soils, ground cover, critical areas, adjacent areas, existing development, existing stormwater facilities. The Jefferson County website provides an Internet Map Server (IMS)function(http://www.co.jefferson.wa.us). If available, a Development Review Division(DRD) planner may be able to assist you in collecting this information. Analyze the information to determine site limitations, including: • Areas with high potential for erosion and sediment deposition(based on soil properties, slope,etc.); • Locations of sensitive and critical areas (e.g., vegetative buffers, wetlands, steep slopes, floodplains, geologically hazardous areas,streams,susceptible aquifer recharge areas,etc.); and • The natural receiving waters to which the stormwater runoff either directly or eventually discharges. This information will be useful in site design and in the completion of the Permanent Stormwater Control Plan and Construction SWPPP. STEP 2: PREPARE PRELIMINARY DEVELOPMENT LAYOUT Based upon the analysis of existing site conditions, locate the buildings, driveways, roads, parking lots,and landscaping features for the proposed development. Consider the following points when laying out the site: • Fit development to the terrain to minimize land disturbance; confine construction activities to the least area necessary and away from critical areas; • Preserve areas with natural vegetation(especially forested areas)as much as possible; • On sites with a mix of soil types, locate impervious areas over less permeable soil (e.g., till) and try to restrict development over more porous soils(e.g., outwash); • Cluster buildings together; • Minimize impervious areas;and • Maintain and utilize the natural drainage patterns. The preliminary development layout will assist in determining threshold discharge areas for calculating whether size thresholds under Minimum Requirements#6, #7, and #8 (for"large" projects)are exceeded and as a basis for the drawings and maps required for the Stormwater Site Plan. stormwater site plan template.doc—rev.4282014 2 • • S LC _ °• V E STEP 3: PERFORM AN OFF-SITE ANALYSIS' Pd , 1 7 2'15 This step is for "large" projects (i.e., adding 5,000 square feet or more of new impervious surface, converting % acres of pervious surfaces to lawn or landscaped areas, or converting 2 '/:acres of forested area to pasture) at the discretion of the UPC Administrate t T See Volume I, Section 2.6.2 for more information. STEP 4: REVIEW THE APPLICABLE MINIMUM REQUIREMENTS The Stormwater Calculation Worksheet is a required submittal for all development and redevelopment land use applications. Completing the Worksheet helps determine the broad category of the proposal—"small," "medium," or 'large" project—and the applicable Minimum Requirements. "Small" projects need to meet Minimum Requirement#2 only. "Medium" projects need to meet Minimum Requirements#1 through #5. "Large" projects need to meet all the Minimum Requirements, #1 through#9. The Minimum Requirements are as follows: 1. Preparation of Stormwater Site Plans(Chapter 3 of Manual) 6. Runoff Treatment 2. Construction Stormwater Pollution Prevention 7. Flow Control 3. Source Control of Pollution 8. Wetlands Protection 4. Preservation of Natural Drainage Systems and Outfalls 5. On-site Stormwater Management 9. Operation and Maintenance The Manual provides descriptions and instructions in Volume I,Chapter 2. Information sheets, application materials, and DRD planners can help describe the Minimum Requirements to applicants. Note: "Large"projects, as part of meeting Minimum Requirements #6 – Runoff Treatment – and #7 – Flow Control, are compared to Volume I, Chapter 2 in the Manual to determine whether on-site stormwater management BMPs are sufficient or treatment facilities or flow control facilities are required. The flow control determination may necessitate use of the Western Washington Hydrology Model managed by the Department of Ecology. Consult Sections 2.5.6 and 2.5.7 of Volume 1, Chapter 2 of the Manual for more information. Again, the easiest way to meet stormwater requirements is to design the project so that natural drainage is preserved, impervious surface is limited, and full dispersion (BMP T5.30) is implemented. By using "low impact development"techniques in the site design, the need for treatment and flow control facilities is eliminated, simplifying preparation of the Stormwater Site Plan and often the site construction process itself. For more information on these techniques,consult the"Low Impact Development"Information Sheet. STEP 5: PREPARE A PERMANENT STORMWATER CONTROL PLAN Select stormwater control BMPs and facilities that will serve the project site in its developed condition. The selection process is presented in Volume I, Chapter 4. After consideration is given to how selected BMPs and facilities fit within and serve the entire preliminary development layout, the designer may want to reconsider the site layout to reduce the need for construction of facilities or the size of the facilities by reducing the amount of impervious surfaces created and increasing the areas to be left undisturbed. The Permanent Stormwater Control Plan should contain the following sections(Section 3.1.5 of Volume I,Chapter 3): • Existing Site Hydrology(i.e.,the behavior of water on the site—above, below, and on the ground) • Developed Site Hydrology (special requirements for projects and threshold discharge areas within projects that requirement treatment and flow facilities) • Performance Standards and Goals • Flow Control System • Water Quality System • Conveyance System Analysis and Design Essentially, in terms of site hydrology, the developed condition of the site should match the pre-developed condition, with is forested land cover (unless reasonable, historic information is provided that indicates the site was prairie prior to settlement). For "large" projects, totals of impervious surfaces, pollution-generating impervious surfaces, and pollution generating pervious surfaces must be tabulated for each threshold discharge area for which on-site BMPs are the sole stormwater management approach. stonnwater site plan template.doc-rev.4282014 3 • P/'' 1 7 ^n19 STEP 6: PREPARE A CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (SWPPP)--' The Construction SWPPP for projects adding or replacing 2,000 square feet of impervious surface or more or clearing 7,660 square feet or more (i.e., "medium" or"large" projects), must contain sufficient information to demonstrate to the UDC Adrnihisjrator.thaf'the- potential pollution problems have been adequately addressed for the proposed project. An adequate Construction SWPPP includes a narrative and drawings. The narrative is a written statement to explain and justify the pollution prevention decisions made for a particular project. The narrative contains concise information concerning existing site conditions, construction schedules, and other pertinent items that are not contained on the drawings. The drawings and notes describe where and when the various BMPs should be installed, the performance the BMPs are expected to achieve, and actions to be taken if the performance goals are not achieved. There are 12 Elements that must be considered in the development of a Construction SWPPP, unless site conditions render that element unnecessary and the exemption from that element is clearly justified in the narrative. The 12 Elements cover the general water quality protection strategies for limiting site impacts during construction and are described in detail in Section 2.5.2, Volume I of the Manual. The 12 Elements of Minimum Requirement#2, Construction Stormwater Pollution Prevention,are: 1. Mark Clearing Limits 6. Protect Slopes 11. Maintain BMPs 2. Establish Construction Access 7. Protect Drain Inlets 12. Manage the Project 3. Control Flow Rates 8. Stabilize Channels and Outlets 13. Protect Low Impact Development 4. Install Sediment Controls 9. Control Pollutants BMP's 5. Stabilize Soils 10. Control De-watering For ease of use, the Stormwater Site Plan submittal template below includes a section that lists the 12 Elements and provides the opportunity to include sufficient information for rural residential and other relatively simple Construction SWPPPs. For more complex projects,a separate narrative and set of plans may be preferred or required. Volume II of the Manual is dedicated to Construction Stormwater Pollution Prevention. A step-by-step BMP selection process and a complete description of the BMPs applicable to each element is provided in Chapters 3 and 4. Additionally, DCD provides a Construction Stormwater Pollution Prevention (SWPP) Best Management Practices (BMPs) Packet that summarizes the 12 Elements and excerpts from the Manual sample sediment and erosion control measures for typical rural residential development. The Packet should prove useful for completing the Construction SWPPP component of the submittal template. On construction sites that infiltrate all stormwater runoff, the primary consideration in the preparation of the Construction SWPPP is the protection of the infiltration facilities from fine sediments during the construction phase and protection of ground water from other pollutants. On construction sites that discharge to surface water, the primary consideration in the preparation of the Construction SWPPP is compliance with the State Water Quality Standards. The step-by-step procedure outlined in Volume II, Section 3.2 is recommended for the development of these Construction SWPPPs. STEP 7: COMPLETE THE STORMWATER SITE PLAN The Stormwater Site Plan encompasses the entire submittal to Jefferson County in conjunction with a land use or building permit application. The following documents or sections should be included: • Project Overview • Existing Conditions Summary • Off-site Analysis Report(if required;usually for"large"projects) • Permanent Stormwater Control Plan • Special Reports and Studies(such as soil testing,wetland delineation,etc., if applicable) • Other Permits(approvals required by other regulatory agencies that include stormwater management conditions) • Operation and Maintenance Manual(for each flow control and treatment facility, if applicable) • Bond Quantities Worksheet (for performance bond or other financial guarantee for proper construction and operation of construction site BMPs and permanent drainage facilities, if required) The submittal template below is designed for rural residential and other relatively small or simple projects. For larger and more complex projects—particularly those that involve stormwater treatment and/or flow control—more information may be required and an independent Stormwater Site Plan may be the preferable submittal format. 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 applicant should review to check that these requirements are satisfied and that all information provided is true and correct prior to signing and submitting the Stormwater Site Plan. (The signature box appears at the end of the submittal template.) stormwater site plan template doc—rev.4/202014 4 • STORMATER SITE PLAN SUBMITTAL TEMPLATE (1 MLA# Project/Applicant Name: Habitat for Humanity-^1I I Brookside Lot 6 PROJECT OVERVIEW 1. Describe the proposed developed conditions of the site. Indicate position and relative size of proposed -Iry --� improvements on the site map. DP1'"l 1"1MT The site currently is undelveoped land with native grasses and blackberry bushes. The—site_ is a rectangle running East- West with Brookside street r.o.w. along the East property line. Chimacum Creek and a Community owned space is on the Western third, the septic fields in the middle, and a new single family home (1,432 s.flot coverage) with two car parking spaces and driveway will be built on the Eastern third. EXISTING CONDITIONS SUMMARY 2. Describe the existing topography. Indicate contours on the site map. The property is relatively level, sloping slightly down from the East to the West. There is a somewhat steeper slope from Brookside street to approximately 20' into the property. 3. Describe the existing vegetation. Indicate native vegetation areas on the site map. The site is covered with grasses and blackberry bushes. 4. Describe the existing soils. Indicate soil type on the site map. Soils are Casey silt loam with gravelly sandy loam below. 5. Describe the existing site hydrology (i.e. drainage; behavior of water on the site—above, below and on the ground). Indicate existing stormwater drainage to and from the site on the site map. Depict separate drainage basins on the site map, if applicable, and indicate acreage of each. Water seems to sink easily into the top layers of soil and retain there to some extent. Below grade, water flows Chimacum creek. 6. Describe any excess levels of noise generated by the proposed use of activity: There are no excess levels of noise other than typical residential usage. 7. Describe significant geographic features and critical areas (i.e., environmentally sensitive areas such as wetlands, streams, steep slopes, etc.) on the site. Indicate location on the site map. Chimacum Creek runs across the property on the West end. 8. Describe the general vicinity of the site, including adjacent land uses and structures, utilities, roads, and sensitive/critical areas(streams, wetland, lakes, steep slopes, etc.) The land use to the north is RR 1:5, to the east RR 1:20, the South AL 1:20 and to the west RR 1:5. The site is served by a gravel private 2-lane road, Brookside Street. The site is served by Jefferson County PUD#1 water. Chimacum Creek runs across the property on the West end. PERMANENT STORMWATER CONTROL PLAN 9. Describe the developed site hydrology, as proposed. Indicate whether stormwater will be fully dispersed (i.e., per BMP T5.30 in the Manual) or, if not, what types of stormwater flow control will be utilized for the site or specific threshold discharge areas with in the site. Locate these facilities on the site plan and differentiate proposed facilities from existing facilities. Roof runoff will be diverted to an existing drainage ditch on the north side of the property through tightlines. The driveway runoff will flow onto the property and through native vegetation. 1 of 4 10. If the project requires the•use of stormwater treatment facilities, describe the types of stormwater treatment facilities proposed for use on the site. Locate these facilities on the site plan and differentiate proposed facilities from existing facilities. [This is normally for"large" projects or projects that involve the potential for dispersion of contaminants.] (� I c N/A � � � 1./J �� 11. Describe the performance goals and standards applicable to the project. The performance goals are to infiltrate stormwater on site and prevent pollution from reaching the adjacent creek. — DE,T[OPV_NT 12. Describe the flow control system. Roof runoff: tightlines to and existing drainage ditch. Driveway runoff: sheet flow to dispersion Swale. 13. Describe the water quality system. N/A 14. Describe the conveyance system analysis and design. N/A 15. Describe the source of fill material, physical characteristics of fill material and deposition of excess material. Fill material will consist of native soil removed from excavation for house footings. This material will be spread in areas of the site cleared for septic system. 16. Proposed method of placement and compaction consistent with the applicable standards on Appendix Chapter 33 of the Uniform Building code. N/A 17. Describe the proposed surfacing material. The driveway will be gravel. 18. Describe methods for restoration of the site. Re-use and spread native soil on disturbed areas, encourage the growth of native vegetation and remove non-native and invasive weeds. 19. An Operation and Maintenance Manual is required for each flow control and treatment facility. [This is normally required for"large" projects only and only those for which facilities are required to control flow or treat runoff.] If included, list the Manuals here. N/A 20. List here and include any special reports or studies conducted to prepare the Stormwater Site Plan. None 21. List other necessary permits and approvals as required by other regulatory agencies. If those permits or approvals include conditions that affect the drainage plan or contain more restrictive drainage-related requirements, describe those conditions or restrictions here. Building permit. Septic Permit approved. 2 of 4 s CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (SWPPP) SECTION 1 — CONSTRUCTION SWPPP NARRATIVE 1. Construction Stormwater Pollution Plan Elements. Describe how each of the Construction SWPPP elements has been or will be addressed. Identify the type and location of BMPs used to satisfy the required element. If an element is not applicable to the proposal,justify in writing. Descriptions of the 12 Elements are found at Volume II Section 3.2.3 of the Manual (beginning on page 3-7). 12 Required Elements— Construction SWPPP 1. Mark Clearing Limits. O M E Prior to construction, limits of areas to be cleared will be delineated i`tYt stakes and plas i l fencing, per BMP C103. Trees to be preserved will be flagged per BMP .C101 2. Establish Construction Access. LJ Construction entrance at existing driveway will be established per BMP C105 r" DEVELOPMENT 3. Control Flow Rates. N/A Slope on this site is shallow enough that natural flow will be very minimal. 4. Install Sediment Controls. N/A The site is level. 5. Stabilize Soils Stockpiled soil, if any, will be protected with plastic sheeting per BMP C123. 6. Protect Slopes. N/A No slopes 3:1 or steeper location on site. 7. Protect Drain Inlets. N/A No drain inlets on site. 8. Stabilize Channels and Outlets. Drainage ditch is existing and stable. 9. Control Pollutants. Pollutants will be controlled at their source. No vehicle maintenance will be done on site. Concrete truck cleaning will be done so that wastewater stays on site, per BMP C151. 10. Control De-Watering (the act of pumping groundwater or stormwater away from an active construction site). Excavation de-watering, if needed, will disperse water on site and be allowed to filter through native soil and vegetation. 11. Maintain Best Management Practices (BMPs). Construction entrance, straw bales, plastic sheeting and construction limit fencing will be inspected and maintained on a monthly basis. These items will be removed no later than 30 days after completion of construction project. 12. Manage the Project. See information provided on Phasing and Construction Schedule. 3 of 4 • 2. Adjacent Areas. • a. Description of the adjacent areas that may be affected by site disturbance (e.g., streams, lakes, wetlands, residential areas, roads). All runoff will be filtered before it reaches any adjacent areas. b. Description of the downstream drainage path leading from the site to the receiving body of water (minimum distance of 400 yards.) The drainage path is to drainage ditch on the North side of the property. Which leads to Chimacum creek. All septic and buildings are beyond the 100' creek buffer. 3. Environmentally Sensitive Areas. a. Description of environmentally sensitive areas that are on or adjacent to the site. Chimacum Creek runs across the property on the West end. b. Description of special requirements for working in or near environmentally sensitive areas. All work will be performed outside of the 100' creek buffer zone. 4. Erosion Problem Areas. Description of potential erosion problems on site in the context of the characteristics of the on-site soils (e.g., erodibility, settleabliity, permeability, depth, texture, soil structure). N/A No slopes steep enough to pose erosion problems. 5. Construction Phasing. a. Construction sequence. (1) gravel driveway (2) single family residence b. Construction phasing (if proposed) N/A 6. Construction Schedule. West season is October 1 through April 30 (page 2-21 of the Manual). I. Provide a proposed construction schedule. April 2015: grading and foundation May 2015 — September 2015: framing, enclosing and finishing II. Wet Season Construction Activities. a. Proposed wet season construction activities. None, project will be completed by October. b. Proposed wet season construction activities for environmentally sensitive areas. None, project will be completed by October. 7. Financial/Ownership Responsibilities. a. Identify the property owner responsible for the initiation of bonds and/or other financial securities. Habitat for Humanity of East Jefferson County b. Describe bonds and/or other evidence of financial responsibility of liability associated with erosion and sedimentation impacts. N/A 8. Engineering Calculations. Provide Design Calculations on a separate sheet for the following, if applicable. a. Sediment Ponds/Traps. :z! n �/ N/A ,' 77 2015 N/A ` 1, d. Runoff/Stormwater Detention Calculations \ MAR ' rEfryGl;GUUi�E OIlleg T nr MOWN DEV 4 of 4 • • SECTION II—EROSION AND SEDIMENT CONTROL PLAN Sediment and erosion control measures may be depicted on the master land use application plot plan, a stormwater site plan, and/or a separate Construction SWPPP site plan. This is a checklist to ensure that the following are depicted on a site plan: 1. General. a. Vicinity Map b. Jefferson County Approval Block c. Erosion and Sediment Control Notes 2. Site Plan. a. Legal description of subject property. b. North arrow. c. Indicate boundaries of existing vegetation(e.g.,tree lines, pasture areas,etc.). d. Identify and label areas of potential erosion problems. e. Identify FEMA base flood boundaries and Shoreline Management boundaries(if applicable). f. Show existing and proposed contours. g. Indicate drainage basins and direction of flow for individual drainage areas. h. Label final grade contours and identify developed condition drainage basins. i. Delineate areas that are to be cleared and graded. j. Show all cut and fill slopes indicating top and bottom of slope catch lines. 3. Conveyance Systems. a. Designate locations for swales, interceptor trenches, or ditches. b. Show all temporary and permanent drainage pipes,ditches,or cut-off trenches required for erosion&sediment control. c. Provide minimum slope and cover for all temporary pipes or call out pipe inverts. d. Shows grades,dimensions, and direction of flow in all ditches,swales,culverts and pipes. e. Provide details for bypassing off-site runoff around disturbed areas. f. Indicate locations and outlets of any dewatering systems. 4. Location of Detention Best Management Practices(BMPs). Identify location of detention BMPs. 5. Erosion and Sediment Control Facilities. a. Show the locations of sediment trap(s), pond(s),pipes and structures. b. Dimension pond berm widths and inside and outside pond slopes. c. Indicate the trap/pond storage required and the depth, length, and width dimensions. d. Provide typical section views through pond and outlet structure. e. Provide typical details of gravel cone and standpipe, and/or other filtering devices. f. Detail stabilization techniques for outlet/inlet. g. Detail control/restrictor device location and details. h. Specify mulch and/or recommended cover of berms and slopes. i. Provide rock specifications and detail for rock check dam(s), if applicable. j. Specify spacing for rock check dams as required. k. Provide front and side sections of typical rock check dams. I. Indicate the locations and provide details and specifications for silt fabric. m. Locate the construction entrance and provide a detail. 6. Detailed Drawings. Any structural practices used that are not referenced in the Ecology Manual should be explained and illustrated with detailed drawings. 7. Other Pollutant BMPs. Indicate on the site plan the locations of BMPs to be used for the control of pollutants other than sediment(e.g., concrete wash water). 8. Monitoring Locations. Indicate on the site plan the water quality sampling locations to be used for monito •e - :•- yon the construction site. Sampling stations should be located upstream and downstre-•• • - • •re -.--n MAR 1 7 201 „.„4 stormwater site plan templale.dos-rev.4282014 S Stormwater Site Plan Changes If the designer wishes to make changes or revisions to the originally approved Stormwater Site Plan, the proposed revisions shall be submitted to DCD prior to construction. The submittal shall include substitute pages that include all proposed changes, revised drawings showing any structural changes, and any other supporting information that explains and supports the reason for the change. Final Corrected Plan Submittal If the project included construction of conveyance systems, treatment facilities, flow control facilities, or structural source control BMPs (not standard on-site stormwater management BMPs), the applicant shall submit a final corrected plan ("as-builts")when the project is completed. These should be engineering drawings (stamped by a licensed civil engineer) that accurately represent the project as constructed. APPLICANT SIGNATURE By signing the Construction SWPPP worksheet, I as the applicant/owner attest that the information provided herein is true and correct to the best of my knowledge. I also certify that this application is being made with the full knowledge and consent of all owners of the affected property. 3-13-Z0 I S (LANDO ER OR AUTHORIZED RE ESENTA SIGNATURE) (DATE) THIS SPACE MAYBE USED FOR ADDITIONAL NOTES, IF NEEDED: ; ii� . • �', MAR 1 7 2015 II LJ COUNTY i.OF COMMUNITY DEVELOPMENT storm water site plan template.doc-rev.4/282014 12