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HomeMy WebLinkAboutCDP 2020-0017; SAREM RESIDENCE; PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN; 2020-05-29CITY OF CARLSBAD PRIORITY DEVELOPMENT PROJECT (PDP} PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN (SWQMP} FOR SAREM RESIDENCE 4005 SKYLINE ROAD PROJECT ID: CDP 2020-0017 ENGINEER OF WORK: PREPARED FOR: SCOTTSAREM 6684 LEMON LEAF DRIVE, CARLSBAD, CA 92011 TEL: (760)533-2470 PREPARED BY: TOAL ENGINEERING, INC. 139 AVENIDA NAVARRO SAN CLEMENTE, CA 92672 TEL: (949)492-8586 DATE: 05/29/2020 TABLE OF CONTENTS Certification Page Project Vicinity Map FORM E-34 Storm Water Standard Questionnaire Site Information FORM E-36 Standard Project Requirement Checklist Summary of PDP Structural BMPs Attachment 1: Backup for PDP Pollutant Control BMPs Attachment 1 a: OMA Exhibit Attachment 1 b: Tabular Summary of DMAs and Design Capture Volume Calculations Attachment 1c: Harvest and Use Feasibility Screening (when applicable) Attachment 1d: Categorization of Infiltration Feasibility Condition (when applicable) Attachment 1 e: Pollutant Control BMP Design Worksheets/ Calculations Attachment 2: Backup for PDP Hydromodification Control Measures Attachment 2a: Hydromodification Management Exhibit Attachment 2b: Management of Critical Coarse Sediment Yield Areas Attachment 2c: Geomorphic Assessment of Receiving Channels Attachment 2d: Flow Control Facility Design Attachment 3: Structural BMP Maintenance Thresholds and Actions Attachment 4: Single Sheet BMP (SSBMP) Exhibit CERTIFICATION PAGE Project Name: SAREM RESIDENCE Project ID: CDP 2020-0017 I hereby declare that I am the Engineer in Responsible Charge of design of storm water BMPs for this project, and that I have exercised responsible charge over the design of the project as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with the requirements of the BMP Design Manual, which is based on the requirements of SDRWQCB Order No. R9-2013-0001 (MS4 Permit) or the current Order. I have read and understand that the City Engineer has adopted minimum requirements for managing urban runoff, including storm water, from land development activities, as described in the BMP Design Manual. I certify that this SWQMP has been completed to the best of my ability and accurately reflects the project being proposed and the applicable source control and site design BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the plan check review of this SWQMP by the City Engineer is confined to a review and does not relieve me, as the Engineer in Responsible Charge of design of storm water BMPs for this project, of my responsibilities for project design. Engineer of Work's Signature, PE Number & Expiration Date Print Name Company Date ,,0-, 1/ .. ./ l /$ $!f-'f .,, ~ II> ,p· 'I" O" 1;, ~ ~-1 '\ \ \ 0-q \ PROJECT VICINITY MAP 1;' ----\ ~ lo I i \ rJ>~ l .., "'~ \~ \ "'"'+ -:S. "#. :! '.t ;') ... ~ Q source : http://ocpw.maps.arcgis.com/apps/PublicGallery IJ "' i ij a ;;i -,; i I ~ l ::, 11 $1.JlU .. l ct \ C City of Carlsbad ! INSTRUCTIONS: STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue (760) 602-2750 www.carlsbadca.gov To address post-development pollutants that may be generated from development projects, the city requires that new development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual, refer to the Engineering Standards (Volume 5). This questionnaire must be completed by the applicant in advance of submitting for a development application (subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of storm water standards that must be applied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to 'STANDARD PROJECT' requirements or be subject to 'PRIORITY DEVELOPMENT PROJECT' (PDP) requirements. Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has responsibility for making the final assessment after submission of the development application. If staff determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than initially assessed by you , this will result in the return of the development application as incomplete. In this case, please make the changes to the questionnaire and resubmit to the city. If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the questions, please seek assistance from Land Development Engineering staff. A completed and signed questionnaire must be submitted with each development project application. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. PROJECT INFORMATION PROJECT NAME: SAREM RESIDENCE PROJECT ID: CDP 2020-0017 ADDRESS: 4005 SKYLINE ROAD APN: 207-072-17 The project is (check one): IX! New Development D Redevelopment The total proposed disturbed area is: 26,435 ft2 ( 0.607 ) acres The total proposed newly created and/or replaced impervious area is: 11,900 fl2 ( 0.273 ) acres If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the SWQMP # of the larger development project: Project ID N/A SWQMP#: Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your application to the city. E-34 Page 1 of 4 REV 02/16 STEP1 TO BE COMPLETED FOR ALL PROJECTS To determine if your project is a "development project", please answer the following question: YES NO Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building □ IZI or structure that do not alter the size {See Section 1.3 of the BMP Design Manual for guidance)? If you answered "yes" to the above question, provide justification below then go to Step 5, mark the third box stating "my project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant information. Justification/discussion: {e.g . the project includes only interior remodels within an existing building): If vou answered "no" to the above question, the project is a 'development project', go to Step 2. STEP2 TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.{3), please answer the following questions: Is your project LIMITED to one or more of the following: YES NO 1. Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria: a) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non- erodible permeable areas; □ l]I b) Designed and constructed to be hydraulically disconnected from paved streets or roads; c) Designed and constructed with permeable pavements or surfaces in accordance with USEPA Green Streets quidance? 2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in □ Ix! accordance with the USEPA Green Streets guidance? 3. Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual? □ ~ If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark the second box stating "my project is EXEMPT from PDP ... " and complete applicant information. Discussion to justify exemption { e.g. the project redeveloping existing road designed and constructed in accordance with the USEPA Green Street guidance): If you answered "no" to the above questions, your project is not exempt from PDP, go to Step 3. E-34 Page 2 of4 REV 04/17 STEP3 TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1 )): YES NO 1. Is your project a new development that creates 10,000 square feet or more of impervious surfaces collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, !Kl □ and public development projects on oublic or orivate land. 2. Is your project a redevelopment project creating and/or replacing 5,000 square feet or more of impervious surface collectively over the entire project site on an existing site of 10,000 square feet or □ IZl more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public develooment oroiects on oublic or orivate land. 3. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and □ IZl refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial Classification (SIC) code 5812). 4. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface collectively over the entire project site and supports a hillside development project? A hillside □ IXI development project includes develooment on anv natural slooe that is twentv-five oercent or areater. 5. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is □ IZl a land area or facility for the temporary parking or storage of motor vehicles used personally for business or for commerce. 6. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious street, road, highway, freeway or driveway surface collectively over the entire project D !XI site? A street, road, highway, freeway or driveway is any paved impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles. 7. Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more of impervious surface collectively over the entire site, and discharges directly to an Environmentally Sensitive Area (ESA)? "Discharging Directly to" includes flow that is conveyed overland a distance of □ 00 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).* 8. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface that supports an automotive repair shop? An automotive repair □ 00 shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC) codes: 5013, 5014, 5541, 7532-7534, or 7536-7539. 9. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category includes D 00 RGO's that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily Traffic (ADTI of 100 or more vehicles oer dav. 10. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land □ I&] and are expected to generate pollutants post construction? 11 . Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of impervious surface or (2) increases impervious surface on the property by more than 10%? (CMG □ IZI 21.203.040) If you answered "yes" to one or more of the above questions, your project is a PDP. If your project is a redevelopment project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a PDP ... " and complete applicant information . If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.' Go to step 5, check the second box stating "My oroject is a 'STANDARD PROJECT' ... " and comolete aoolicant information. E-34 Page 3 of4 REV 04/17 STEP4 TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP) ONLY Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)): YES NO Does the redevelopment project result in the creation or replacement of impervious surface in an amount of less than 50% of the surface area of the previously existing development? Complete the percent impervious calculation below: Existing impervious area (A) = sq. ft. □ □ Total proposed newly created or replaced impervious area (B) = sq. ft. Percent impervious area created or replaced (B/A)*100 = % If you answered "yes", the structural BMPs required for PDP apply only to the creation or replacement of impervious surface and not the entire development. Go to step 5, check the first box stating "My project is a PDP .. ." and complete applicant information. If you answered "no," the structural BMP's required for PDP apply to the entire development. Go to step 5, check the check the first box stating "My project is a PDP .. ." and complete aoolicant information. STEPS CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION 1K] My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application. 0 My project is a 'STANDARD PROJECT' OR EXEMPT from PDP and must only comply with 'STANDARD PROJECT' stormwater requirements of the BMP Manual. As part of these requirements, I will submit a "Standard Project Requirement Checklist Form E-36' and incorporate low impact development strategies throughout my project. Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations and exhibits to verify if 'STANDARD PROJECT' stormwater requirements apply. D My Project is NOT a 'development project' and is not subject to the requirements of the BMP Manual. Applicant Information and Signature Box Applicant Name: Applicant Title: Applicant Signature: Date: .. • Environmentally Sens1t1ve Areas include but are not limited to all Clean Water Act Section 303(d) 1mpa1red water bodies; areas designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County of San Diego; Habitat Management Plan; and any other equivalent environmentally sensitive areas which have been identified by the City. This Box for City Use Onlv YES NO City Concurrence: □ □ By: Date: Project ID: E-34 Page4 of4 REV 04/17 SITE INFORMATION CHECKLIST Project Summary Information Project Name SAREM RESIDENCE Project ID CDP 2020-0017 Project Address 4005 SKYLINE ROAD CARLSBAD, CA 92008 Assessor's Parcel Number(s) (APN(s)) 207-072-17 Project Watershed (Hydrologic Unit) Carlsbad 904 Parcel Area 0.572 Acres (24,904 Square Feet) Existing Impervious Area 0.115 Acres (5,000 Square Feet) (subset of Parcel Area) Area to be disturbed by the project 0.607 Acres (26,435 Square Feet) (Project Area) Project Proposed Impervious Area 0.273 Acres (11 ,900 Square Feet) (subset of Project Area) Project Proposed Pervious Area 0.334 Acres (14,535 Square Feet) (subset of Project Area) Note: Proposed Impervious Area+ Proposed Pervious Area= Area to be Disturbed by the Project. This may be less than the Parcel Area. Description of Existing Site Condition and Drainage Patterns Current Status of the Site (select all that apply): (X) Existing development Previously graded but not built out Agricultural or other non-impervious use (X) Vacant, undeveloped/natural Description/ Additional Information: The site includes an existing single-family residence with appurtenant hardscape, walls and landscape areas on the easterly half, and undeveloped natural slope on the westerly half. Existing Land Cover Includes (select all that apply): (X) Vegetative Cover (X) Non-Vegetated Pervious Areas (X) Impervious Areas Description/ Additional Information: The existing land cover includes planter areas around the front and sides of the building, and natural area on the rear slope beyond the house. Existing parcel pervious area = 19,904 sq. ft. Underlying Soil belongs to Hydrologic Soil Group (select all that apply): NRCS Type A (X) NRCS Type B -See Soil Map from San Diego County Hydrology Manual (next page) NRCS Type C NRCS Type D Approximate Depth to Groundwater (GW): GW Depth < 5 feet 5 feet< GW Depth< 10 feet 10 feet < GW Depth < 20 feet (X) GW Depth > 20 feet Existing Natural Hydrologic Features (select all that apply): Watercourses Seeps Springs Wetlands (X) None Description of Existing Site Topography and Drainage: Under existing conditions, site runoff travels primarily via surface flow across the property in a westerly direction and onto the adjacent downstream property(s) to the west, and ultimately into Sunnyhill Drive (public street). It is assumed that runoff collected within drainage inlets around the existing building is discharged onto the natural rear slope on the westerly half of the property, although no outlets were uncovered during topographic survey of the site. A 2" -4" high ridge in the Skyline Road riqht-of-way is intended to keep all street runoff within the riqht-of-wav. Description of Proposed Site Development and Drainage Patterns Project Description / Proposed Land Use and/or Activities: The project consists of a new single-family residence with appurtenant hardscape, walls, pool , and landscape areas. The front yard features a driveway serving garages on either side of the front entry; the side yards include walkways and landscape areas; the rear yard is comprised of terraced patios, a swimming pool, a sport court, and landscaping improvements throughout. LisUdescribe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features): Impervious surfaces include the proposed residence (4 ,800 sq . ft.), the driveway (4 ,300 sq. ft.), side and rear yard walkways/stairways (2,000 sq . ft.), and a sport court (800 sq. ft .). LisUdescribe proposed pervious features of the project (e.g., landscape areas): Pervious surfaces include planter areas adjacent to impervious walkways, permeable paving for the terraced rear patios, as well as a garden in the SW corner of the property. Does the project include grading and changes to site topography? (X) Yes No Description/ Additional Information: Cut and fill of the existing rear slope is necessary to create the terraced rear patios. Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)? (X) Yes No Description/ Additional Information: The proposed drainage system is designed to follow the existing drainage pattern and includes: 1) roof drains, drain inlets, and solid pipes to collect and convey all runoff to the rear of the site; 2) on-site treatment of project storm water via Biofiltration BMP located at the west end of the property; 3) underground storage to limit post-project discharge to match pre-project conditions; and 4) a drainage spreader at the west PL to distribute surface flow on to the adjacent property. Identify whether any of the following features, activities, and/or pollutant source areas will be present (select all that apply): (X) On-site storm drain inlets Interior floor drains and elevator shaft sump pumps Interior parking garages (X) Need for future indoor & structural pest control (X) Landscape/Outdoor Pesticide Use (X) Pools, spas, ponds, decorative fountains, and other waterfeatures Food service Refuse areas Industrial processes Outdoor storage of equipment or materials Vehicle and Equipment Cleaning Vehicle/Equipment Repair and Maintenance Fuel Dispensing Areas Loading Docks (X) Fire Sprinkler Test Water Miscellaneous Drain or Wash Water (X) Plazas, sidewalks, and parking lots Identification of Receiving Water Pollutants of Concern Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable}: Property runoff will be collected and conveyed (via solid pipe} across the site in a westerly direction to an offline Biofiltration BMP (for on-site treatment}. A flow control box will limit off-site discharge to the pre-project rate, utilizing an underground storage chamber to detain the difference between the pre-and post-project volumes during the storm peak (see separate Hydrology Study prepared by Toal Engineering, Inc.}. Runoff is discharged via drainage spreader (a subsurface pipe with pop-up emitters equally spaced at the same surface elevation} designed to distribute the runoff across the entire rear property line and reduce downstream erosion potential. The project runoff ultimately makes its way to Sunnyhill Drive, where it is collected by the city storm drain system and discharged to Agua Hedionda Lagoon (Hydrologic Area 904.3 -Carlsbad Watershed Management Area). List any 303(d} impaired water bodies within the path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable}, identify the pollutant(s} and/or stressor(s} causing impairment, and identify any TMDLs for the impaired water bodies: 303{d) Impaired Water Body Pol I utant{ s )/Stressor{ s) TMDLs N/A Identification of Project Site Pollutants Identify pollutants anticipated from the project site based on all proposed use(s} of the site (see BMP Design Manual Appendix 8.6): Also a Receiving Not Applicable to Anticipated from the Water Pollutant of Pollutant the Project Site Project Site Concern Sediment YES NO Nutrients YES NO Heavy Metals N/A NO Organic Compounds N/A NO rTrash & Debris YES NO Pxygen Demanding YES NO Substances Oil & Grease YES NO Bacteria & Viruses YES NO Pesticides YES NO Hydromodlfication Management Requirements Do hydromodification management requirements apply (see Section 1.6 of the BMP Design Manual}? Yes, hydromodification management flow control structural BMPs required. (X) No, the project will discharge runoff directly to existing underground storm drains discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean. No, the project will discharge runoff directly to conveyance channels whose bed and bank areconcrete-lined all the way from the point of discharge to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean. No, the project will discharge runoff directly to an area identified as appropriate for an exemption by the WMAA for the watershed in which the project resides. Description / Additional Information (to be provided if a 'No' answer has been selected above}: Runoff within Sunnyhill Drive flows in a southerly direction along the street before entering the City storm drain system via curb inlet catch basin at the intersection with Tamarack Avenue, and ultimately discharging to Agua Hedionda Lagoon. This project is located within the exemption boundary per the "Hydromodification Exemption Analyses for Select Carlsbad Watersheds," prepared by Chang Consultants, dated September 17, 2015. Critical Coarse Sediment Yield Areas* *This Section only required if hydromodification management requirements apply Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas exist within the project drainage boundaries? J Yes J No, No critical coarse sediment yield areas to be protected based on WMAA maps If yes , have any of the optional analyses presented in Section 6.2 of the BMP Design Manual been performed? J 6.2.1 Verification of Geomorphic Landscape Units (GLUs} Onsite J 6.2.2 Downstream Systems Sensitivity to Coarse Sediment J 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield AreasOnsite J No optional analyses performed, the project will avoid critical coarse sediment yield areas identified based on WMAA maps If optional analyses were performed, what is the final result? J No critical coarse sediment yield areas to be protected based on verification of GLUsonsite J Critical coarse sediment yield areas exist but additional analysis has determined tta protection is not required. Documentation attached in Attachment 8 of theSWQMP. J Critical coarse sediment yield areas exist and require protection. The project will implement management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas are identified on the SWQMP Exhibit. Discussion/ Additional Information: Flow Control for Post.Project Runofr -This Section onlv reaulred if hvdromodlflcatlon manaaement reauirements annlv List and describe point(s) of compliance (POCs) for flow control for hydromodification management (see Section 6.3.1 ). For each POC, provide a POC identification name or number correlating to the project's HMP Exhibit and a receiving channel identification name or number correlating to the project's HMP Exhibit. Has a geomorphic assessment been performed for the receiving channel(s)? J No, the low flow threshold is 0.1O2 (default low flow threshold) J Yes, the result is the low flow threshold is 0.102 J Yes, the result is the low flow threshold is O .3Q2 J Yes, the result is the low flow threshold is 0.5O2 If a geomorphic assessment has been performed, provide title, date, and preparer: Discussion/ Additional Information: (optional) Other Site Reaulrements and Constraints When applicable, list other site requirements or constraints that will influence storm water management design, such as zoning requirements including setbacks and open space, or City codes governing minimum street width, sidewalk construction, allowable pavement types, and drainage requirements. NIA Optional Additional Information or Continuation of Previous Sections As Needed This space provided for additional information or continuation of information from previous sections as needed. NIA C cityof Carlsbad Project Name: SAREM RESIDENCE Project ID: CDP 2020-0011 DWG No. or Building Permit No.: NIA STANDARD PROJECT REQUIREMENT CHECKLIST E-36 Project lnfonnatlon Source Control BMPs Development Services Land Development Engineering 1635 Faraday Avenue (760) 602-2750 www.carlsbadca.gov All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See Chapter 4 and Appendix E.1 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to implement source control BMPs shown in this checklist. Answer each category below pursuant to the following. • "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the Model BMP Design Manual. Discussion~ustification is not required. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be provided. Please add attachments if more space is needed. • "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g ., the project has no outdoor materials storage areas). Discussion/justification may be orovided. Source Control Requirement Applied? SC-1 Prevention of Illicit Discharges into the MS4 ■Yes I □ No I □ NIA Discussion/justification if SC-1 not implemented: SC-2 Storm Drain Stenciling or Signage □Yes / ■ No / D N/A Discussion/justification if SC-2 not implemented: Single-family residential SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind □Yes I □No I ■ N/A Dispersal Discussion/justification if SC-3 not implemented: E-36 Page 1 of4 Revised 09/16 Source Control Raoulrernent (continued\ Annlled? SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and □Yes □No ■NIA Wind Disoersal Discussion/justification if SC-4 not implemented: SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal ■Yes □No □ N/A Discussion/justification if SC-5 not implemented: SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and identify additional BMPs. (See Table in Appendix E.1 of BMP Manual for i:iuidance ). ■ On-site storm drain inlets ■Yes □No □ N/A □ Interior floor drains and elevator shaft sump pumps □Yes □No ■ NIA ■ Interior parking garages □Yes ■No 0 N/A ■ Need for future indoor & structural pest control ■Yes ONo ON/A ■ Landscape/Outdoor Pesticide Use ■Yes □No □ N/A ■ Pools, spas, ponds, decorative fountains, and other water features ■Yes □No 0 N/A D Food service □Yes □No ■ N/A □ Refuse areas □Yes □No ■ NIA D Industrial processes □Yes ONo ■ N/A D Outdoor storage of equipment or materials □Yes □No ■NIA D Vehicle and Equipment Cleaning □Yes □No ■NIA □ Vehicle/Equipment Repair and Maintenance □Yes ONo ■ N/A D Fuel Dispensing Areas □Yes □No ■ N/A D Loading Docks □Yes ONo· ■NIA ■ Fire Sprinkler Test Water ■Yes □No ON/A O Miscellaneous Drain or Wash Water □Yes □No ■NIA ■ Plazas, sidewalks, and parking lots ■Yes ONo D N/A For "Yes" answers, identify the additional BMP per Appendix E.1 . Provide justification for "No" answers. Drain inlets: Remove buildup of sediment or debris on and around the inlet. Parking Garages: No interior drains that require protection or connection to the sewer system. Pest Control: Building designed to discourage entry of pests; integrated pest management information provided to owners Landscaping: Designed and maintained to minimize both irrigation needs and impacts from pests/pesticides. Pool: pool shall be connected to the sanitary sewer system for backwash/drainage. Fire sprinklers: fire sprinkler test water shall drain to the sanitary sewer. Plazas, sidewalks, parking lots: All on-site paving shall be swept regularly to prevent accumulation of litter and debris. E-36 Page 2of4 Revised 09/16 Site Design BMPs All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to implement site design BMPs shown in this checklist. Answer each category below pursuant to the following. • "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of the Model BMP Design Manual. Discussion / justification is not required. • "No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be provided. Please add attachments if more space is needed. • "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be provided. Site Design Requirement I Applied? SD-1 Maintain Natural Drainaae Pathwavs and Hvdroloaic Features I □Yes I D No I ■ NIA Discussion/justification if SD-1 not implemented: Project encompasses the entire site. No existing natural drainage pathways or hydrologic features. SD-2 Conserve Natural Areas, Soils, and Veaetation I □ Yes I □ No I ■NIA Discussion/justification if SD-2 not implemented: The project encompasses the entire site. No natural areas will be conserved. SD-3 Minimize Impervious Area I ■Yes I □No ID NIA Discussion/justification if SD-3 not implemented: Impervious area has been minimized by constructing a multi-story building, minimizing walkway widths in the side yards, and using pervious paving for level patios/walkways west of the residence. SD-4 Minimize Soil Compaction I ■Yes I □No I ON/A Discussion/justification if SD-4 not implemented: SD-5 Impervious Area Dispersion I ■Yes I □No I □ NIA Discussion/justification if SD-5 not implemented: Where practicable, hardscape areas have been designed to drain into pervious areas before collection into the site drainage system. E-36 Page3of4 Revised 09/16 Site Dealan Raoulrement (continued) I Annlled? SD-6 Runoff Collection I ■ Yes I □ No I D N/A Discussion/justification if SD-6 not implemented: Permeable pavement (SD-68) will be used for the patio areas and walkways in the rear yard (westerly portion of the site, beyond the proposed residence). SD-7 Landscaping with Native or Drought Tolerant Species I ■Yes I □ No ID NIA Discussion/justification if SD-7 not implemented: SD-8 Harvestina and Usina Precioitation I D Yes I □ No I ■ NIA Discussion/justification if SD-8 not implemented: Not feasible per Form 1-7 completed herein. E-36 Page4of4 Revised 09/16 SUMMARY OF PDP STRUCTURAL BMPS PDP Structural BMPa All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control must be based on the selection process described in Chapter 5. PDPs subject to hydromodification management requirements must also implement structural BMPs for flow control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both storm water pollutant control and flow control for hydromodification management can be achieved within the same structural BMP(s). PDP structural BMPs must be verified by the City at the completion of construction. This may include requiring the project owner or project owner's representative to certify construction of the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must be maintained into perpetuity, and the City must confirm the maintenance (see Section 7 of the BMP Design Manual). Use this form to provide narrative description of the general strategy for structural BMP implementation at the project site in the box below. Then complete the PDP structural BMP summary information sheet for each structural BMP within the project (copy the BMP summary information page as many times as needed to provide summary information for each individual structural BMP). Describe the general strategy for structural BMP implementation at the site. This information must describe how the steps for selecting and designing storm water pollutant control BMPs presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated together or separate. Per Form 1-8 (completed by Petra Geosciences and included herein} infiltration on this site with NRCS Type B soils is only partially feasible due to subsurface paralic terrace deposits. Per Form 1-7 (included herein} the project site has insufficient landscape surface area and other conditions for harvest and reuse. Not feasible. The site has one Drainage Management Area (DMA}, and the selected Structural BMP is PR-1 : Biofiltration with partial retention. All site runoff will flow into a biofiltration system at the west end of the property for treatment before flowing off-site for discharge to Sunnyhill Drive. Storm events exceeding the design treatment volume will bypass the Biofiltration BMP. Structural BMP Summary lnfonnation (Copy this page as needed to provide lnfonnatlon for each individual proposed structural BMPl Structural BMP ID No. 1 DWG N/A Sheet No. N/A Type of structural BMP: Retention by harvest and use (HU-1) Retention by infiltration basin (lNF-1) Retention by bioretention (INF-2) Retention by permeable pavement (INF-3) (X) Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1) Flow-thru treatment control included as pre-treatmenUforebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) Detention pond or vault for hydromodification management Other (describe in discussion section below) Purpose: (X) Pollutant control only Hydromodification control only Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP Other (describe in discussion section below) Discussion (as needed): All parcel runoff will be treated by a Biofiltration BMP with partial retention (PR-1 ). The system consists of surface ponding, soil media, and gravel storage. Design volume runoff entering the system will pond on the surface before filling the voids within the underlying media and gravel layers as it filters through via gravity. Filtered runoff is then discharged from the system via subsurface infiltration into the underlying soils or perforated underdrain pipe that connects back into the site drainage system for off-site discharge to Sunnyhill Drive. ATTACHMENT 1 BACKUP FOR PDP POLLUTANT CONTROL BMPS This is the cover sheet for Attachment 1. Check which Items are Included behind this cover sheet: Attachment Contents Checklist Sequence Attachment 1 a DMA Exhibit (Required) See DMA Exhibit Checklist on the back of this Attachment cover sheet. (24"x36" Exhibit typically required) (X) Included Attachment 1 b Tabular Summary of DMAs Showing (X) Included on DMA Exhibit in DMA ID matching DMA Exhibit, DMA Attachment 1 a Area, and DMA Type (Required)* *Provide table in this Attachment OR on DMA Exhibit in Attachment 1 a Attachment 1c Form 1-7, Harvest and Use Feasibility (X) Included Screening Checklist (Required unless the entire project will use infiltration BMPs) Refer to Appendix B.3-1 of the BMP Design Manual to complete Form 1-7. Attachment 1d Form 1-8, Categorization of Infiltration (X) Included Feasibility Condition (Required unless the project will use harvest and use BMPs) Refer to Appendices C and D of the BMP Design Manual to complete Form 1-8. Attachment 1 e Pollutant Control BMP Design (X) Included Worksheets I Calculations (Required) Refer to Appendices B and E of the BMP Design Manual for structural pollutant control BMP design guidelines Use this checklist to ensure the required information has been included on the DMA Exhibit: The OMA Exhibit must identify: {X) Underlying hydrologic soil group {X) Approximate depth to groundwater N/A Existing natural hydrologic features (watercourses, seeps, springs, wetlands) N/A Critical coarse sediment yield areas to be protected (if present) {X) Existing topography and impervious areas {X) Existing and proposed site drainage network and connections to drainage offsite {X) Proposed grading {X) Proposed impervious features {X) Proposed design features and surface treatments used to minimize imperviousness {X) Drainage management area (OMA) boundaries, OMA ID numbers, and OMA areas (square footage or acreage), and OMA type (i.e., drains to BMP, self-retaining, or self-mitigating) {X) Structural BMPs (identify location and type of BMP) ,. .... -m•IE -TfEAlMENT CONTRa.. 0 -CJ --© IICJU,-;ig• CJ NIW.lttflllQI lCl.v IMPACT DESIGN (LLD.) SOURCECOfflROL © ............. n BMP TABLE , .. 110. _.,., """""' """""' -....... --· ~· ...JL" _,., ... -181M(t """'""' --· -· WQMPLEGEND --+ --.f'---IIJN:)FFF\.0¥lf'CIAECTON PR0P09B> ITOIIJil ~"' TOAL -INC. @@@ pNffYR£6,ofrf&l!lfFOA.MAINTEKAHCe MME ICOfflllflEM --rn -~---- l'IIIIIIEIIO PS)NN•,O PUH~8Y' -CM.f:t-.OIP.E COlll'll,IIT T'Oolril.Ei«:111:EltNGINC.. M:Ol!EII Pl!IYIM>!!MYM!? f"NetMEW:E CAPW'J BlPNOm 1 'lllM ... WWIIIIMlOll'l'lO.IISlll.lB>IOWlllllf...cfllllSl"I N:~llCNOll'IIIEUl'WII. t.CDWtGlllllOM~ .... OIIMla!EElWffilOU'fMOII I IIO~lOlllll:1111\lSIIN~l'IKIOllftAll,-TW'Et WfllltlltMOAN'f'fOIN..RIOlilTllll:CffYEIIGllfflt. I 11>oa:IIPMCf''ll'IU.llliMlffl:OlllllllllEaTI'lillf'ECTIDIIIWf w.,-,ECIIOlll•l'f!O,EctfOll:~lEIIIIWOOlllllluet'OII t. llEfElllll~.wflll:EMElfTDOCUll'EII? I.IHNOJEC'TIWPFOll"°°"O.W.11f0fl:IMM1t c, ... ,l I N Gl•■(IJPN O ~f o•,.~ .. ! f ,•,. "o1uT•~••T~ ................. ... "······-'" ... ,. ••••• , 111 1 ...... , .. ,, ......... . --lt.C.£1191- 81# CONSTRUCTION 00 !NSPE'CTIQ,I NOTES: THEEOWM..LVEIIFYnt,,,Tl'El'IW,NENT ..... IIIE ~ON«Jc,,fN,TlNIIINCOMl\.11111«:EwmtTIE ~El'tEQUAE..a.TL"'l!Clfl:TOOCOJPAM:YTHE IEOW...,-PllilOWIE: I PtfOTOCIW'tCIOIFTWEMT.-..V.TONO/F~ tMP1 l'ftlOflt TO COfaT'FtuCTlOJrl, OUIDIO OONSTl'IUCTIO"-;NDATFNlil.MT#UATION. t. A'l'l'ETITAMPEOLETlV'\19'11FYN:ll'ttlt,TPERll!YEMr IWIMECOtCTl'tUC'fEON«JOl'EMlUGP£llTHE REQUIAEIIIENTIO/FntE"'""'D\EOPI.A/<e. J. PtiOTOCfW>HITOVUIFVTH.\TPE~-~ QWt/TVntEATMEt.n'IIOMo,QE!t.'11 IE&l!HSTIII.LEO l"fllOJtTOAEl.EMEOFIECUAl11U, THEOEVE!..OPE/tll ltEW'ONS!et.EFOfl'acvi:.N11THEP£lliW,SITIIIIIPS""VE N0f a&HAEMOO.'EO Ofl MOOIAEO 9YTHE l'EWltOIW:o-.Elt OflllQl\ ....mtouTTHE~OV!ll Ol'TltE OTYEIIGM:Elt. I j I ~ ..,,,. _.,_ -.. ,. _.,_ --· ,."· --...,,. _.,_ 0 -cu•• _.,_ ..,,,. 11.DU . • T a.e ;t ,,:; -..,,,. 11,la If • CT'JI Cl!l-9!-~ lw 1:emi::&>~I ... ---... -.,,_ ------· 11J-15'0'VI 11J-O'O"W z !-r---:-----t-------..;..---a!:!11 f LIIIU-n. 117'30'0'W ,,r-15'0~ ,,1·ovw 11S-45'0"W 116'30'0'W z ::'.'"'".,...;:.s.iaii4------+--+~ ~ (") 0 C: ~ z ~----,.+----+i,, ~ Legend -llojorRoodo • lnco,pamod City a.i, HYDROLOOIC SOIL GROUP N l¥fralogic an,_., U-od •~09icOra141A H,drologlc On>-. B H,drologlc an,_., C • ..,..,. ... 0..,..0 □No Soil Oat■ Note: Soil Data Source USDA/NRCS SSURGO Soils 2007 A 31.50 3 Miles Tl-IS '-"JI IS PROvllEDWTTliOUTWMRANTVOF /4HYIOIC), Em-ER EXPfl:SS ~ MPI..ED, KUJOlfO, BUT NOT LMTEO TO, lliE IMPLIED WARRANTIES OF MEROWfl'ABIUlY NfO FTIMESS FOR A PARTICUl.AR PUAPOSE. ~ SllnGtS. Al Rlghll Reeerved. Thll product ~y IDM.ln Womwlon tom tie SANOAG Reglonlll lnfllffl\llfon Sy_,,IJ!t,~ ClfmlbtlreproducedwMhol.Alheviri111n _,,....,.,,_ Ttu product n.y ccnllaln lnfolmllon lflllhldl ha been rep!Oduatd wlti pa'fflNicn g/91111111 IP( Thlmu &ott.a Mapa. Appendix I: Forms and Checklists Harvest and U sc Feasibility Checklist Form 1-7 1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during the wet season? III Toilet and urinal flushing IXl Landscape irrigation D Other: _____ _ 2. If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section B.3.2. [Provide a summary of calculations here] Toilet Flushing: 4 persons x 9.3 gallons/person/day x 36 hours x 1.5 day/36 hours Irrigation: 930** gallons/ acre/36 hours x 0.334 acres = 311 gal ( 42 cu. ft.) 56 gal (7.5 cu. ft.) 930 gallons represents 50% low water use and 50% high water use per Table B.3-3. 3. Calculate the DCV using worksheet B.2-1. DCV = __ 6_lO __ (cubic feet) 3a. Is the 36 hour demand greater than or equal to the DCV? □ Yes / Ciil:No c::::> i Harvest and use appears to be feasible. Conduct more detailed evaluation and sizing calculations to confirm that DCV can be used at an adequate rate to meet drawdown criteria. 36. Is the 36 hour demand greater than 0.25DCV but less than the full DCV? □ Yes / N No c=> -0, Harvest and use may be feasible. Conduct more detailed evaluation and sizing calculations to determine feasibility. Harvest and use may only be able to be used for a portion of the site, or ( optionally) the storage may need to be upsized to meet long term capture targets while draining in longer than 36 hours. Is harvest and use feasible based on further evaluation? D Yes, refer to Appendix E to select and size harvest and use BMPs. lX[ No, select alternate BMPs. 1-2 3c. Is the 36 hour demand less than 0.25DCV? N Yes .(). Harvest and use is considered to be infeasible. February 2016 Appendix I: Forms and Checklists Categorization of Infiltration Feasibility Form 1-8 Condition Part t -full JnfiltAtion feasibilkf Smxa,mg Criu;ria Would infiltration of the full design volume be feasible from a physical ~ive withoµt any~irable consequence$ that .C$UU10t be reasooably.mhigated? · · · · .. .. .. .. ... .. . ...... Criteria ·Scteening Question Yes No Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. No Provide basis: The site will be graded such that compacted fill will cover the majority of the area as well as underlain by relatively impermeable paralic terrace deposits. The compacted fill and paralic terrace deposits possess little or no void space and therefore the infiltration rate is considered less than 0.5 inches per hour. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. Provide basis: Infiltration greater than 0.5 inches per hour would result in horizontal infiltration, causing seepage problems and would be detrimental to the project. No Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 1-3 February 2016 Appendix I: Forms and Checklists Criteri a 3 Form I-8 Page 2 of 4 Screening Question Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Yes No Yes Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 4 Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change of seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Yes Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. Part 1 Result * If all answers to rows 1 -4 are ''Yes" a full infiltration design is potentially feasible. The feasibility screening category is Full Infiltration If any answer from row 1-4 is "No", infiltration may be possible to some extent but would not generally be feasible or desirable to achieve a "full infiltration" design. Proceed to Part 2 No *To be completed using gathered site information and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/ or studies may be required by the City to substantiate findings. 1-4 February 2016 Appendix I: Forms and Checklists Form I-8 Page 3 of 4 Part 2 -Partial Infiltration vs, No Infiltration Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated? Criteria 5 Screening Question Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question shall be based on a ·comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D . Yes Yes Provide basis: The site will be graded such that compacted fill will cover the majority of the area as well as be underlain by relatively impermeable paralic terrace deposits. The compacted fill and patalic terrace deposits possess little or no void space. Areas at the site could be designed for infiltration rates less than 0.5 inches per hour. No Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. 6 Can Infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. Yes Provide basis: The site will be gtaded such that compacted"fill will cover the majority of the atea as well as underlain by patalic terrace deposits. The compacted fill and paralic terrace deposits possess little or no void space. Areas at the site could be designed for infiltration without increasing risk of geotechnical hazatds . Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. 1-5 February 2016 Appendix I: Forms and Checklists Criteria 7 Form 1-8 Page 4 of 4 Screening Question Can Infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water table, storm water pollutants or other factors)? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Yes No Yes Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Yes Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. Part2 Result* If all answers from row 5-8 are yes then partial infiltration design is potentially feasible. The feasibility screening catego1y is Partial Infiltration. If any answer from row 5-8 is no, then infiltration of any volume is considered to be infeasible within the drainage area. The feasibility screening category is No Infiltration. Partial Infiltration :+To be completed using gathered site tnformatton and best professional Judgment cons1denng the definition of MEP 10 the MS4 Permit. Additional testing and/ or studies may be required by the City to substantiate findings. 1-6 February 2016 ATTACHMENT 2 BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES [This is the cover sheet for Attachment 2.] Indicate which Items are Included behind this cover sheet: Attachment Contents Checklist Seauence Attachment 2a Hydromodification Management J Included Exhibit (Required} See Hydromodification Management Exhibit Checklist on the back of this Attachment cover sheet. Attachment 2b Management of Critical Coarse J Exhibit showing project drainage Sediment Yield Areas 0/VMAA Exhibit boundaries marked on WMAA is required, additional analyses are Critical Coarse Sediment Yield optional} Area Map (Required} See Section 6.2 of the BMP Design Optional analyses for Critical Coarse Manual. Sediment Yield Area Determination J 6.2.1 Verification of Geomorphic Landscape Units Onsite J 6.2.2 Downstream Systems Sensitivity to Coarse Sediment J 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite Attachment 2c Geomorphic Assessment of Receiving J Not performed Channels (Optional} J Included See Section 6.3.4 of the BMP Design Manual. Attachment 2d Flow Control Facility Design and J Included Structural BMP Drawdown Calculations (Required} See Chapter 6 and Appendix G of the BMP Desian Manual 1 2 3 4 5 6 Appendix B: Stonn Water Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.2-1. DCV Design Capture Volume Worksheet B-2.1 85th percentile 24-hr storm depth from Figure B.1-1 d= 0.60 inches Area tributary to BMP (s) A= 0.572 acres Area weighted runoff factor ( estimate using Appendix 0.49 B.1.1 and B.2.1)** C= unitless Tree wells volume reduction TCV= N/A cubic-feet Rain barrels volume reduction RCV= N/A cubic-feet Calculate DCV = (3630 x C x d x A) -TCV -RCV DCV= 610 cubic-feet **C value= (0.9 x 0.273 ac (roofs/concrete)) + (0.1 x 0.334 ac (pervious paving/landscaping)) 0.572 ac B-10 February 2016 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs .,,..... , ................. _ 1 Remaining DCV after implementing retention BMPs 610 cubic-feet Partial Retention 2 Infiltration rate from Form I-9 if partial infiltration is feasible 0.2* in/hr. 3 Allowable drawdown time for aggregate storage below the underdrain 36 hours 4 Depth of runoff that can be infiltrated [Line 2 x Line 3] 7.2 inches 5 Aggregate pore space 0.40 in/in 6 Required depth of gravel below the underdrain [Line 4/ Line 5] 18 inches 7 Assumed surface area of the biofiltration BMP 185 sq-ft 8 Media retained pore storage 0.1 in/in 9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8)]/12] x Line 7 139 cubic-feet 10 DCV that requires biofiltration [Line 1 -Line 9] 471 cubic-feet BMP Parameters 11 Surface Ponding [6 inch minimum, 12 inch maximum] 8 inches 12 Media Thickness [18 inches minimum], also add mulch layer thickness to 18 inches this line for sizing calculations 13 Aggregate Storage above underdrain invert (12 inches typical) -use 0 12 inches inches for sizing if the aggregate is not over the entire bottom surface area 14 Media available pore space 0.2 in/in 15 Media filtration rate to be used for sizing (5 in/hr. with no outlet contra~ 5 in/hr. if the filtration is controlled by the outlet, use the outlet controlled rate) Baseline Calculations 16 Allowable Routing Time for sizing 6 hours 17 Deptl1 filtered during storm [ Line 15 x Line 16] 30 inches 18 Depth of Detention Storage inches [Line 11 + (Line 12 x Line 14) + (Line 13 x Line 5)] 16.4 19 Total Depth Treated [Line 17 + Line 18] 46.4 inches Option 1 -Biofilter 1.5 times the DCV 20 Required biofiltered volume [1.5 x Line 1 0] 707 cubic-feet 21 Required Footprint [Line 20/ Line 19] x 12 183 sq-ft Option 2 -Store 0.75 of remaining DCV in pores and ponding 22 Required Storage (surface+ pores) Volume [0.75 x Line 10] 353 cubic-feet 23 Required Footprint [Line 22/ Line 18] x 12 259 sq-ft Footprint of the BMP 24 Area draining to the BMP 24,904 sq-ft 25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B .2) 0.49 26 Minin1um BMP Footpru;it [Line 24 x Line 25 x 0.03] 366 sq-ft 27 Footprint of the BMP = Maximum(Minin1um(Line 21, Line 23), Line 26) 183 sq-ft N ote: Line 7 is used to estimate the amount of volume retained by the BMP. Update assumed surface area in Line 7 until its equivalent to the required biofiltration footprint (either Line 21 or Line 23) * Per San Diego County BMP Design Manual for NRCS Type B soils (Table B.2-3) B-26 February 2016 Use this checklist to ensure the required information has been included on the Hydromodlfication Management Exhibit: The Hydromodification Management Exhibit must identify: J Underlying hydrologic soil group J Approximate depth to groundwater J Existing natural hydrologic features (watercourses, seeps, springs, wetlands) J Critical coarse sediment yield areas to be protected (if present) J Existing topography J Existing and proposed site drainage network and connections to drainage offsite J Proposed grading J Proposed impervious features _ J Proposed design features and surface treatments used to minimize imperviousness J Point(s) of Compliance (POC) for Hydromodification Management J Existing and proposed drainage boundary and drainage area to each POC (when necessary, create separate exhibits for pre-development and post-project conditions) J Structural BMPs for hydromodification management (identify location, type of BMP, a'd size/detail) ATTACHMENT 3 Structural BMP Maintenance Information Use this checklist to ensure the required information has been included in the Structural BMP Maintenance Information Attachment: Preliminary Design/Planning/CEQA level submittal: Attachment 3 must identify: J Typical maintenance indicators and actions for proposed structural BMP(s} based on Section 7.7 of the BMP Design Manual Final Design level submittal: Attachment 3 must identify: J Specific maintenance indicators and actions for proposed structural BMP(s}. This shall be based on Section 7. 7 of the BMP Design Manual and enhanced to reflect actual proposed components of the structural BMP(s} J How to access the structural BMP(s} to inspect and perform maintenance J Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow the inspector to view necessary components of the structural BMP and compare to maintenance thresholds} J Manufacturer and part number for proprietary parts of structural BMP(s} when applicable J Maintenance thresholds for BMPs subject to siltation or heavy trash(e.g., silt level posts or other markings shall be included in all BMP components that will trap and store sediment, trash, and/or debris, so that the inspector may determine how full the BMP is, and the maintenance personnel may determine where the bottom of the BMP is . If required, posts or other markings shall be indicated and described on structural BMP plans.} J Recommended equipment to perform maintenance J When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management