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HomeMy WebLinkAboutAMEND 2019-0002; CARLSBAD CORPORATE PLAZA PARKING STRUCTURE; PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN; 2019-11-20CITY OF CARLSBAD PRIORITY DEVELOPMENT PROJECT (PDP) PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) FOR NEXTMED PARKING STRUCTURE CARLSBAD CORPORA TE PLAZA SDP(Minor) 2019-0003 / CDP 2019-0005 / SP(AMEND) 2019-0002 ENGINEER OF WORK: GREGO Y . LANG, P.E. RCE 68075 PASCO LARET SUITER & ASSOCIATES, INC. 535 N. HIGHWAY 101, SUITE A OLANA BEACH, CA 92075 PREPARED FOR: NEXTMED Ill, LLC 6125 Paseo Del Norte, Suite 210 Carlsbad, CA 92011 760-494-9216 PREPARED BY: EXP: 06-30-21 E NOV 2 0 2019 Cl ~ ' A,--{LSBAD PLA. 1 1. G D!'!IS!ON PASCO LARET SUITER & ASSOCIATES CIVIL ENGINEERING+ LAND PLANNING + LAND SURVEYING 535 N. HIGHWAY 101, SUITE A SOLANA BEACH, CA 92075 858-259-8212 DATE: November 20, 2019 ... - .... .. .. -.. --- .. -.. -.. .. ---- • - PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN ENGINEER'S CERTIFICATION PROJECT VICINITY MAP TABLE OF CONTENTS STORM WATER STANDARD QUESTIONNAIRE SITE INFORMATION SUMMARY OF PDP STRUCTURAL BMPs ATTACHMENT 1-Backup for PDP Pollutant Control BMPs NOVEMBER 2019 Attachment 1 a ............................................................................................... DMA Exhibit Attachment 1b ....... Tabular Summary of DMAs and Design Capture Volume Calculations Attachment 1 c ....................................................... Harvest and Use Feasibility Screening Attachment 1d ....................................... Categorization of Infiltration Feasibility Condition Attachment 1e .......................... Pollutant Control BMP Design Worksheets/ Calculations ATTACHMENT 2 -Backup for PDP Hydromodification Control Measures Attachment 2a ..................................................... Hydromodification Management Exhibit Attachment 2b .............................. Potential Critical Coarse Sediment Yield Areas Exhibit Attachment 2c ....................................................................... Flow Control Facility Design ATTACHMENT 3-Structural BMP Maintenance Plan Attachment 3a ...................................................................... Structural BMP Maintenance ATTACHMENT 4-City of Carlsbad Standard Single Sheet BMP Exhibits Attachment 4a ............................................................. Single Sheet BMP Exhibit NEXTMED PARKING STRUCTURE 2 ... • .. .. .. ------- --.. .. -- .. --.. .. .. ... .. .. • PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN CERTIFICATION PAGE Project Name: NextMed Parking Structure Project ID: SDP(Minor) 2019-0003 / CDP 2019-0005 / SP(AMEND) 2019-0002 NOVEMBER 2019 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. Gfu~~ RCE 60075 Pasco Laret Suiter & Associates 535 N. Highway 101, Suite A Solana Beach, CA 92075 NEXTMED PARKING STRUCTURE 3 11/20/2019 Exp: 06-30-21 Date PREl/MlNARY STORM WATER QUAl/TY MANAGEMENT PLAN NOVEMBER 2019 Figure 1 -Vicinity Map CITY or OC£ANS10£ "8 VCNTYMAP N.T.S. NEXTMED PARKING STRUCTURE 4 ~ . City of Carlsbad I 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: NextMed Parking Structure PROJECT ID: ADDRESS: 6183 & 6185 Paseo Del Norte APN: 211-040-18-00 The project is (check one): D New Development 00 Redevelopment The total proposed disturbed area is: 52,556 ft2 ( 1.21 ) acres The total proposed newly created and/or replaced impervious area is: 46,425 ft 2 ( 1.Q? ) 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 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 □ ~ 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 you 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; □ 1K] 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 guidance? 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? □ 1K] 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 Page2 of 4 REV 04/17 To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1 )): 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, and ublic develo ment ro ·ects on ublic or rivate 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 more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public develo ment ro ·ects on ublic or rivate 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 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 develo ment ro·ect includes develo ment on an natural slo e that is twent -five ercent or reater. 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 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 site? A street, road, highway, freeway or driveway is any paved impervious surface used for the trans ortation of automobiles, trucks, motorc cles, 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 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 ro ·ect to the ESA i.e. not commin led with flows from ad·acent 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 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 RGO's that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily Traffic ADT of 100 or more vehicles er da . 10. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land 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%? (CMC 21.203.040 YES NO □ Kl □ □ !Kl □ Iii Ix) □ □ 00 □ 00 □ 00 □ Ix) □ [x] □ 00 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 statin "M ro ·ect is a 'STANDARD PROJECT' ... " and com lete a licant information. E-34 Page 3 of 4 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) = 148 674 sq. ft. 00 □ Total proposed newly created or replaced impervious area (B) = 46425 sq. ft. Percent impervious area created or replaced (B/A)*100 = 31% % 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. STEP& CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION Ix] 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. □ 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: Greaorv W. Lana P.E. Applicant Title: Princigal Applicant Signature:_ 4r{J. ~ Date: 8/12/2019 .. .. * Environmentally Sens1t1ve Areas include but are not limited to all Clean Water Act Section 303(d) impaired 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 Citv Use Ontv YES NO City Concurrence: □ □ By: Date: Project ID: E-34 Page 4 of 4 REV 04/17 PRELIMINA RY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 SITE INFORMATION CHECKLIST Prolect Summarv Information Project Name NextMed Parking Structure Project ID Project Address 6183 & 6185 Paseo Del Norte Carlsbad, CA 92011 Assessor's Parcel Number(s) (APN(s)) 211-040-18 Hydrologic Unit: Carlsbad Project Watershed (Hydrologic Unit) Hydrologic Area: Encinas Hydrologic Sub-Area#: 904.40 Parcel Area 4.59 Acres ( ±199,940 Square Feet) Existing Impervious Area .2A1_Acres ( 148,674 Square Feet) (subset of Parcel Area) Area to be disturbed by the project 1.21 Acres ( 52,556 Square Feet) (Project Area) Project Proposed Impervious Area 1.07 Acres (46,425 Square Feet) (subset of Project Area) Project Proposed Pervious Area (including 0.14 Acres ( 6,131 Square Feet) D.G., Deminimus, and Self-MitiQatinQ Area) Note: Proposed Impervious Area+ Proposed Pervious Area= Area to be Disturbed by the Project. This may be less than the Parcel Area. NEXTMED PARKING STRUCTURE 5 PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN Description of Existing Site Condition and Drainage Patterns Current Status of the Site (select all that apply): 119 Existing development o Previously graded but not built out □ Agricultural or other non-impervious use □ Vacant, undeveloped/natural Description/ Additional Information: The existing site is comprised of a surface parking lot with landscaped islands. Existing Land Cover Includes (select all that apply): 119 Vegetative Cover □ Non-Vegetated Pervious Areas 119 Impervious Areas Description/ Additional Information: See description above. Underlying Soil belongs to Hydrologic Soil Group (select all that apply): o NRCS Type A D NRCS Type B D NRCS Type C 119NRCS Type D Approximate Depth to Groundwater (GW): D GW Depth < 5 feet □ 5 feet < GW Depth < 1 0 feet □ 1 0 feet < GW Depth < 20 feet 119GW Depth > 20 feet Existing Natural Hydrologic Features (select all that apply): □ Watercourses □ Seeps □ Springs □Wetlands 119 None Description/ Additional Information: N/A NEXTMED PARKING STRUCTURE 6 NOVEMBER 2019 .. .. .. --... ... -- ... ... - - ... .. - -... .. - • -- • .. .. .. .. • PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 Description of Existing Site Topography and Drainage [How is storm water runoff conveyed from the site? At a minimum, this description should answer (1) whether existing drainage conveyance is natural or urban; (2) describe existing constructed storm water conveyance systems, if applicable; and (3) is runoff from offsite conveyed through the site? if so, describe]: In the existing condition storm water runoff from the site flows overland across the parking lot in a northwesterly direction and is collected in the existing storm drain located along the northern boundary of the parking lot. Flow continues northeasterly in the storm drain where it discharges onsite to a grouted rip rap pad, then re-enters a short segment of storm drain prior to discharging via curb outlet to Paseo Del Norte. Runoff flows northerly as gutter flow along Paseo Del Norte, enters a curb inlet and discharges to Encinas Creek which flows westerly and discharges to the Pacific Ocean. No offsite runoff is conveyed through the site . The existing buildings onsite flow directly to the existing storm drain adjacent to the buildings separate from the onsite flow described above. NEXTMED PARKING STRUCTURE 7 PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 Description of Proposed Site Development and Drainage Patterns Project Description / Proposed Land Use and/or Activities: The project proposes to reconfigure the layout of the existing surface parking lot and construct a new parking structure within the existing parking lot, requiring demolition of existing islands and asphalt for parking structure footings and the addition of HMP biofiltration basins for stormwater treatment and flow control. Utility re-routing will be required for the public waterline and private storm drain onsite due to the impact of the proposed parking structure footprint. A new easement dedication will be required for the waterline re-routing coupled with vacation of the abandoned portion of the waterline easement. List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features): Proposed impervious features include the parking structure and the resurfacing of areas where existing landscape will be removed. List/describe proposed pervious features of the project (e.g., landscape areas): Proposed pervious areas include new landscape areas and biofiltration basins. Does the project include grading and changes to site topography? ~ Yes □ No Description/ Additional Information: Minor grading will be performed where existing landscape areas will be removed, parking garage footings are proposed, and HMP biofiltration basins are located. Grading will not change the overall site topography. Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)? ~ Yes □ No Description / Additional Information: In the proposed condition, storm water runoff from the proposed parking structure will be collected and conveyed to the HMP biofiltration basins. The adjacent disturbed areas will be conveyed to a Modular Wetland System or to pervious areas for dispersion. Flow from the project will discharge to the onsite existing storm drain and continue as it does in the existing condition. The proposed drainage pattern mimics the existing condition. NEXTMED PARKING STRUCTURE 8 .. -.. - ----- - - • • .. • --- • .. • • ... • .. .. • PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 Identify whether any of the following features, activities, and/or pollutant source areas will be present (select all that apply}: ~ On-site storm drain inlets □ Interior floor drains and elevator shaft sump pumps □Interior parking garages □ Need for future indoor & structural pest control ~ Landscape/Outdoor Pesticide Use □ Pools, spas, ponds, decorative fountains, and other water features □ 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 □ Fire Sprinkler Test Water □ Miscellaneous Drain or Wash Water ~ Plazas, sidewalks, and parking lots NEXTMED PARKING STRUCTURE 9 PRELIMINA RY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 Identification of Recelvlna 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): Runoff from the project site discharges via curb outlet to Paseo Del Norte. Runoff flows northerly as gutter flow along Paseo Del Norte, enters a curb inlet and discharges to Encinas Creek which flows westerly and discharges to the Pacific Ocean. 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)/stressor(s) causing impairment, and identify any TMDLs for the impaired water bodies: 303(d) Impaired Water Body Pollutant( s )/Stressor( s) TMDLs None Identification of Prolect 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 X N/A Nutrients X N/A Heavy Metals X N/A Organic Compounds X Trash & Debris X N/A Oxygen Demanding X N/A Substances Oil & Grease X N/A Bacteria & Viruses X Pesticides X N/A NEXTMED PARKJNG STRUCTURE 10 PRELIMINA RY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 20/9 Hydromodlflcatlon Manaaement Reaulrements Do hydromodification management requirements apply (see Section 1.6 of the BMP Design Manual)? 00 Yes, hydromodification management flow control structural BMPs required. □ 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 are concrete-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 WMM for the watershed in which the project resides. Description/ Additional Information (to be provided if a 'No' answer has been selected above): NEXTMED PARKING STRUCTURE 11 PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 Crltlcal Coarse Sediment Yleld Areas* *This Section only required If hydrornodlflcatlon management requirements aDDIY Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas exist within the project drainage boundaries? D Yes (See discussion below) ~ 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? D 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite D 6.2.2 Downstream Systems Sensitivity to Coarse Sediment D 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite D 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? D No critical coarse sediment yield areas to be protected based on verification of GLUs onsite D Critical coarse sediment yield areas exist but additional analysis has determined that protection is not required. Documentation attached in Attachment 2B of the SWQMP. D 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: Refer to Attachment 2b for a Potential Critical Coarse Sediment Yield GIS overlay of the project area and surrounding areas. NEXTMED PARKING STRUCTURE 12 PREllMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 Flow Control for Post.Project Runoff' -.Yhls Section onl re ulred If h drornodlflcatlon mana ement re ulrements a 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. There is one POC for the project, POC-1, located at the northeastern boundary of the site. Refer to the exhibit located in Attachment 2a. NEXTMED PARKJNG STRUCTURE 13 PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN Has a geomorphic assessment been performed for the receiving channel(s)? ~ No, the low flow threshold is 0.1 Q2 (default low flow threshold) □ Yes, the result is the low flow threshold is 0.1 Q2 □ Yes, the result is the low flow threshold is 0.3Q2 □ Yes, the result is the low flow threshold is 0.5Q2 NOVEMBER 2019 If a geomorphic assessment has been performed, provide title, date, and preparer: Discussion/ Additional Information: (optional) NEXTMED PARKJNG STRUCTURE 14 PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 20/9 Other Site Requirements 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. Optional Addltlonal Information or Continuation of Previous Sections As Needed This space provided for additional information or continuation of information from previous sections as needed. NEXTMED PARKJNG STRUCTURE 15 C cicyof Carlsbad STANDARD PROJECT REQUIREMENT CHECKLIST E-36 Project Information Project Name: NextMed Parking Garage Project ID: CDP-2019-0005; SOP 2019-0003: AMEND 2019-0002 DWG No. or Building Permit No.: 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/justification 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 provided. Source Control Requirement Applied? SC-1 Prevention of Illicit Discharges into the MS4 Iii Yes □No D N/A Discussion/justification if SC-1 not implemented: SC-2 Storm Drain Stenciling or Signage Iii Yes ONo ON/A Discussion/justification if SC-2 not implemented: SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind □Yes □No Iii N/A Dispersal Discussion/justification if SC-3 not implemented: The project has no outdoor materials storage areas E-36 Page 1 of 4 Revised 09/16 Source Control Reaulrement (continued) Applied? SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and □Yes □ No Iii N/A Wind Dispersal Discussion/justification if SC-4 not implemented: The project has no outdoor materials storage areas SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal Iii Yes □No □ NIA Discussion/justification if SC-5 not implemented: The project trash area is a covered enclosure and runoff will be routed from enclosure to BMP 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 guidance). Iii On-site storm drain inlets Iii Yes □No □ N/A □ Interior floor drains and elevator shaft sump pumps □Yes □No Iii N/A □ Interior parking garages □Yes □No Iii N/A □ Need for future indoor & structural pest control □Yes □No Iii N/A Iii Landscape/Outdoor Pesticide Use Iii Yes □ No □ N/A □ Pools, spas, ponds, decorative fountains, and other water features □Yes □ No Iii N/A □ Food service □Yes □No Iii N/A Iii Refuse areas Iii Yes □No □ N/A □ Industrial processes □ Yes □No Iii N/A □ Outdoor storage of equipment or materials □ Yes □No Iii N/A □ Vehicle and Equipment Cleaning □Yes □No Iii N/A □ Vehicle/Equipment Repair and Maintenance □ Yes □ No Iii N/A □ Fuel Dispensing Areas □ Yes □No Iii N/A □ Loading Docks □ Yes □No Iii N/A □ Fire Sprinkler Test Water □ Yes □No Iii N/A □ Miscellaneous Drain or Wash Water □ Yes □ No Iii N/A Iii Plazas, sidewalks, and parkinQ lots li)Yes □No □ NIA For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" answers. Biofiltration BMPs and a Modular Wetlands Biofiltration System (MWS) will be used to treat all new impervious areas including parking areas, trash enclosure, sidewalks and parking lot areas. Where drainage is not feasible to flow to the biofiltration basins or MWS, an impervious dispersion area (SD-5) will be utilized. Drainage will be routed to the amended soils within the parking lot island. Overflow drains will be provided to allow runoff to flow to the existing storm drain. E-36 Page 2 of 4 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 Applled? SD-1 Maintain Natural Drainage Pathways and Hydrologic Features I □Yes I □ No I 1i1 NIA Discussion/justification if SD-1 not implemented: There are no natural drainage pathways or hydrologic features in existing parking lot. SD-2 Conserve Natural Areas, Soils, and Vegetation I □Yes I 0 No I Ii] N/A Discussion/justification if SD-2 not implemented: There are no natural areas, soils or vegetation in existing parking lot. Existing parking islands with vegetation that need to be removed will be replaced with parking islands with amended soils. SD-3 Minimize Impervious Area I ~Yes I □ No I □ N/A Discussion/justification if SD-3 not implemented: SD-4 Minimize Soil Compaction I ~ Yes I D No I □ NIA Discussion/justification if SD-4 not implemented: SD-5 Impervious Area Dispersion I ~Yes I □ No I □ N/A Discussion/justification if SD-5 not implemented: Storm water runoff that is not treated by biofiltration basins or MWS will be routed to an impervious dispersion area located within the parking island. E-36 Page 3 of 4 Revised 09/16 Site Design Requirement (continued) I Aonlled? SD-6 Runoff Collection I ~Yes I □ No I □ N/A Discussion/justification if SD-6 not implemented: SD-7 LandscapinQ with Native or DrouQht Tolerant Species I ~Yes I D No ID N/A Discussion/justification if SD-7 not implemented: SD-8 Harvestinq and Using Precipitation I D Yes I ~ No I □ N/A Discussion/justification if SD-8 not implemented: Harvesting and Using Precipitation is not a feasible BMP for this project. Refer to Attachment 1 c. E-36 Page4 of 4 Revised 09/16 PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN OCTOBER 20/9 SUMMARY OF PDP STRUCTURAL BMPS PDP Structural BMPs 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). NEXTMED PARKING STRUCTURE 17 .. -.. -- -- .. ---- - .., -- .. • -.. • .. • - PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER2019 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. DMA-Aand B BIOFILTRA TION (BF-1) Using Section 5.1 of the City of Carlsbad BMP Design Manual (Figure 5-1 and 5-2) Biofiltration (BF-1) was selected as the BMP for OMA-A and B to provide treatment control and hydromodification flow control for the project. With infiltration infeasible at the project location, the facilities will be lined in order for surface waters to discharge via underdrain or overflow to the downstream conveyance system. Per City of Carlsbad Fact Sheet BF-1, "Biofiltration (Bioretention with underdrain) facilities are vegetated surface water systems that filter water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow to the downstream conveyance system. Bioretention with underdrain facilities are commonly incorporated into the site within parking lot landscaping, along roadsides, and in open spaces. Because these types of facilities have limited or no infiltration, they are typically designed to provide enough hydraulic head to move flows through the underdrain connection to the storm drain system. Treatment is achieved through filtration, sedimentation, sorption, biochemical processes and plant uptake." Biofiltration systems are effective at removing sediments and pollutants which are associated with fine particles by filtration through surface vegetation and underlying engineered soil media. These systems can also delay runoff peaks by providing detention and/or retention capacity in the media layer and ponding area through the controlled release of treated runoff. The addition of vegetation not only increases the aesthetic value of these areas, but also enhances the filtration component of the system through plant uptake and helps maintain the porosity of the engineered soil layer. Biofiltration systems can be constructed as either large or small scale devices with native or amended soils. Biofiltration systems, like the systems designed for this project, collect storm water from impervious areas (roof areas and other impervious surfaces) through the site's grading design. The biofiltration systems for this project have been integrated into the drainage design to meet pollutant control and hydromodification requirements for the site. Storm water runoff from the proposed parking structure, OMA-A and B, will be collected and conveyed to the biofiltration basins for treatment. Rip rap energy dissipaters will be located at points where concentrated flow enters the biofiltration basins to minimize erosion from occurring. Biofiltration systems are designed to allow ponding to occur. A soil layer, gravel layer, under drain system, and impermeable liner were designed for the systems due to the poor infiltration rates of the in-situ soil. NEXFMED PARKING STRUCTURE 18 ... ... .. ----.. -.. --.. -- - ---.. - • .. .. -.. .. ... ... - • PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 Biofiltration systems function by allowing ponded runoff to infiltrate down through the mulch layer, amended soil layer, and the gravel layer; ultimately discharging to the onsite storm drain system through the system's perforated under drain. The biofiltration basin areas will be landscaped with a combination of ground covers, shrubs and/or trees as selected by the project's landscape architect. The biofiltration systems will provide water quality treatment for the parking structure and hydromodification flow control for the entire project. DMA-C, D, E, G CDMA Hl BIOFIL TRA TION (BF-3) As part of the project, portions of the surrounding surface parking lot will be disturbed, mainly to demolish existing islands and construct new islands. DMA-D and E will be conveyed to a Modular Wetlands System (MWS) for pollutant control treatment. It is not feasible to drain DMA- C and G to the MWS, therefore, stormwater runoff from an alternate area (DMA H) consisting of existing impervious area will be directed to the MWS for treatment. The total area draining to the MWS and receiving treatment is greater than the actual area requiring treatment. Refer the table below. Impervious (sf) Pervious ( sf} Total (sf) Area Required to be Treated (DMA-C, D, 3,745 1,764 5,509 E and G) Area Actually Being Treated (DMA H = DMA-D + E and 9,032 458 9,490 Existing Impervious Area} DMA-F DISPERSE RUNOFF FROM IMPERVIOUS AREA (SD-5) Disperse runoff from impervious areas was selected as a site design BMP for DMA-F due to the parking lot grades making it infeasible for the runoff to drain to the biofiltration areas or MWS. The dispersion area is the pervious area used to treat runoff from the impervious area by allowing the water to flow through the landscape and amended soils located within parking area island. DMA-F has an impervious to pervious area ratio of 1.1 :1. Soils will be amended to a depth of 11 inches below grade to have the topsoil act as Type A soils. Disperse runoff from impervious areas is effective in impeding runoff discharges, reducing the runoff volume and treating the stormwater runoff when the storm water flows through surface vegetation and underlying amended soils. The parking island is an effective area to allow for im ervious area dis ersion. The arkin island interior has ervious areas bounded b NEXTMED PARKING STRUCTURE 19 .. .... ... .... ... -.. ... - ... --.. -.. .. .. .. • PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 concrete curb and the grade is depressed to allow for ponding of the surface runoff. Curb cuts at select locations on the parking island allow runoff from adjacent areas to flow into the parking island for retention and treatment. A drain system within the parking island allows for storm water to overflow to the storm drain system so that runoff does not back up onto the impervious surface or spill out over the island curb. *The two biofiltration BMPs are sized for hydromodification flow control for all DMAs, the entire disturbed project area including DMAs not draining to the biofiltration basins such as the dispersion area. Dispersion areas are only applicable as pollutant control treatment since it is not feasible to get the runoff from these areas into the biofiltration basins . NEXTMED PARKING STRUCTURE 20 PRELIMINARY STORM WATER QUA LITY MANAGEMENT PLAN NOVEMBER 2019 Structural BMP Summary Information Structural BMP ID No.: 1 (OMA-A) Sheet No. Type of structural BMP: □ Retention by harvest and use (HU-1) □ Retention by infiltration basin (INF-1) □ Retention by bioretention (INF-2) □ Retention by permeable pavement (INF-3) □ Partial retention by biofiltration with partial retention (PR-1) ~ Biofiltration (BF-1) (BMP ID No. 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: □ Pollutant control only □ Hydromodification control only ~ Combined pollutant control and hydromodification control □ Pre-treatmenUforebay for another structural BMP □ Other (describe in discussion section below) Discussion (as needed): NEXTMED PARKING STRUCTURE 21 PRELIMINA RY STORM WATER QUALITY MANAGEMENT PLAN Structural BMP Summary lnfonnatlon Structural BMP ID No.: 2 (DMA-8) Sheet No. Type of structural BMP: □ Retention by harvest and use (HU-1) D Retention by infiltration basin (INF-1) D Retention by bioretention {INF-2) D Retention by permeable pavement (INF-3) □ Partial retention by biofiltration with partial retention (PR-1) ~ Biofiltration (BF-1) (BMP ID No. 2) NOVEMBER 20/9 D 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) D Detention pond or vault for hydromodification management D Other {describe in discussion section below) Purpose: D Pollutant control only □ Hydromodification control only ~ Combined pollutant control and hydromodification control D Pre-treatmenUforebay for another structural BMP D Other (describe in discussion section below) Discussion (as needed): NEXTMED PARKING STRUCTURE 22 PRELIMINA RY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 Structural BMP Summary Information Structural BMP ID No.: 3 (DMA-H) Sheet No. Type of structural BMP: □ Retention by harvest and use (HU-1) □ Retention by infiltration basin (INF-1) □ Retention by bioretention (INF-2) □ Retention by permeable pavement (INF-3) □ Partial retention by biofiltration with partial retention (PR-1) □ Biofiltration (BF-1) □ Flow-thru treatment control included as pre-treatment/forebay 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 00 Other (describe in discussion section below) Purpose: 00 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): (BF-3) Modular Wetland Biofiltration System proprietary BMP for pollutant control treatment. NEXTMED PARKING STRUCTURE 23 PRELIMINARY STORM WATER QUA LITY MANA GEMENT PLAN NOVEMBER 2019 A TT AC HM ENT 1 BACKUP FOR PDP POLLUTANT CONTROL BMPS Attachment Contents Seauence Attachment 1a DMA Exhibit (Required) See DMA Exhibit Checklist on the back of this Attachment cover sheet. (24"x36" Exhibit typically required) Attachment 1 b Tabular Summary of DMAs Showing Checklist ~ Included DMA ID matching DMA Exhibit, DMA D Included as Attachment 1b Area, and DMA Type (Required)* separate from OMA Exhibit Attachment 1 c Attachment 1 d *Provide table in this Attachment OR on DMA Exhibit in Attachment 1 a Form 1-7, Harvest and Use Feasibility Screening Checklist (Required unless the entire project will use infiltration BMPs) Refer to Appendix 8.3-1 of the BMP Design Manual to complete Form 1-7. Form 1-8, Categorization of Infiltration 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. ~ Included □ Not included because the entire project will use infiltration BMPs ~ Included □ Not included because the entire project will use harvest and use BMPs Attachment 1 e Pollutant Control BMP Design ~ Included Worksheets / Calculations (Required) Refer to Appendices B and E of the BMP Design Manual for structural pollutant control BMP design guidelines NEXTMED PAR.KING STRUCTURE 24 Attachment 1 a DMAExhibit 20' I EXISTING BUILDINGB FF-76.2 0 EXISTING BUILD/NGA FF-752 10' 0 20' 40•·5 1-1 _j___~ _ _j____j _ _J ~1-----1 __ __,I C 76 f-76 f= SCALE: 1 • = 20' BIOFIL TRA TION (BF-3) BMP SUMMARY BMP ID BMP TYPE REQUIRED FLOW PROVIDED FLOW RATE (CFS) RATE (CFS) MODULAR 3 WETLANDS SYSTEM 0.038 0.052 MWS-L-4-4 DMA SUMMARY' OMA BMP TYPE IMPERVIOUS PERVIOUS TOTAL AREA AREA (AC) AREA (AC) (ACRES) H BIOFIL TRA T10N 9,032 (0.21) 458 (0.01) 9,490 (0.22) (BF-3) *OMA 'H' EQUIVALENT AREA IS GREATER THAN COMBINED AREA OF OMA C,D,E,&G, PROVIDING TREATMENT VIA MODULAR WETLANDS SYSTEM BIOFILTRATION DEVICE. OVERALL PROJECT HYRDROMODIFICA TION CONTROL PROVIDED AT BIOFIL TRA TION BASIN 1 & 2. TRUCTUR I I I I I 'ARCEL SCALE: 1" = 20' 6" CURB PER~ PLANTING PER PLAN LANDSCAPE ASPHALT PVMT ARCHITECT'S PLAN PER PLAN '·• ...r, I' VARIES • . o?,l;, &-,1,~ _ BOTTOM AND SIDES OF BIO-FILTRATION PLANTER SHALL BE LJNED WITH JO MIL THICK PVC LJNER. PROVIDE 6-INCH OVERLAPPED, THERMAL WELDED SEAMS AT ALL SEAMS. PLACE NON-WOVEN FILTER FABRIC (MIRAFI 140N OR EQUAL) ON EITHER SIDE OF PVC LINER TO PROTECT LINER FROM PUNCTURE ON ALL SIDES, "SANDWICHING" THE PVC LJNER WITH A FABRIC CUSHION. WIDTH VARIES PER PLAN 6" CURB PER PLAN ASPHALT PVMT PER PLAN BIO-FILTRATION BASIN WITH IMPERMEABLE LINER DETAIL NOT TO SCALE PERFORATED PVC PLANTER SUB-DRAIN BMP 1 -0. 70" ORIFICE BMP 2 -0.80" ORIFICE PER APPROVED STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) • I I Know what's below. □ I Call before you dig . ATTACH TO INSIDE OF STORM DRAIN STRUCTURE IN FRONT OF SUB-DRAIN OU7lET. ATTACH WITH TAMPER PROOF BOLTS AT EACH CORNER, TYP. B"XB" SQUARE, MIN., ¼ INCH THICK STEEL PLATE. HOT DIP GALVANIZE AFTER FABRICATION AND DR/LUNG. PLACE NEOPRENE RING BETWEEN THE PLATE AND STRUCTURE WALL PRIOR TO ATTACHMENT FOR A WATER TIGHT CONNECTION LEGEND PROPOSED STORM DRAIN EXIST1NG STORM DRAIN = =: Sil =: _ ---SD --- PROPOSED HARDSCAPEi IMPERYIOUS AREA PROPOSED LANDSCAPING/ Pe1VIOUS AREA f///////////////1 ~ EOllVALENT TFEAlMENT FOR OVERALL DISTU'l8ED AREA OUTSIDE OF PARKING STRUCTURE (OMA C, D, E, AND G) ·• .· ' C. I DRAINAGE MANAGEMENT AREA (OMA} BOUNDARY TREAlMENT CONmOl.. 8MP N~ DRAINAGE MANAGEMENT AFEA (OMA} OVERLAND R..OW DlfECllON ARROW STORM DRAIN R..OW DIAECTION ARROW TREATMENT CONTROL BMPS EIOAL 1RA 110N WITH IMPEAMEAEI..E LINER IMPERVIOUS AFEA DISF'EASION ~f-l @ @ MODUlAA WETLANDS EIOALTRATION SYSTEM ff,~ (EQUIVALENT AFEA TAEATMENT)-9EE SHEET 2 OF 2 , ~ CD 0 .. ¢::::I SOURCE CONTROL BMPS INLEr STENCIL.JNG 0 SOIL INFORMATION SOIL: TYPED DEPTH TO GROUNDWATER SEESO/t..SFEPORT" SfTE INFORMATION= IMPERVIOUS AF/EA: PERVIOUS AF/EA: TOTAL DISTURBED AREA: 85TH PERCENTLE STORM DEPTH: 123AC 0.16AC t09AC 0.57i1 DMA SUMMARY DRA IN AGE IMPERVIOUS MANAGEMENT BMP TYPE AREA (AC) AREA (OMA) A BIOFIL TRA TION (BF-1) 17,471 (0.40) B 8/0FIL TRA TION (BF-1) 24,724 (0.58) C 8/0FIL TRA TION (BF-3)* 1,213 (0.03) D BIOFIL TRA TION 475 (0.01) (BF-3)* E BIOFIL TRA T/ON 680 (0.02) (BF-3)* F DISPERSION 485 (0.01) (SD-5) G BIOFIL TRA T/ON 1,377 (0.03) (BF-3)* PERVIOUS AREA (AC) 1,523 (0.035) 2,407 (0.06) 1,331 (0.03) 0 (0.00) 433 (0.01) 437 (0.01) 0 (0.00) TOTAL AREA (ACRES) 18,994 (0.44) 27,131 (0.62) 2,544 (0.058) 475 (0.011) 1,113 (0.026) 922 (0.021) 1,377 (0.032) *COMBINED DMA AREA TREATED WITH MODULAR WETLANDS SYSTEM BIOF/L TRA TION. OVERALL PROJECT HYRDROMODIFICA TION CONTROL PROVIDED AT BIOFIL TRA TION BASIN 1 & 2 BIOFIL TRA TION (BF-1) BMP SUMMARY BMP ID BMP TYPE REQUIRED BMP PROVIDED BMP AREA (SF) AREA (SF) 1 BIOFIL TRA TION (BF-1) 1100 1101 2 BIOFIL TRA TION (BF-1) 1028 1028 DRILLED ORIFICE PLATE DETAIL NOT TO SCALE PASCO LARET SUITER & ASSOC IATES CIVI L ENGINEERING+ LAND PLAN f\l NG + LArlD SURVEYING 535 North Hi ghway 101, Suite A Solana Beach, CA 92075 ph 858.25 9.8212 I fx 858 .259 .4812 1 plsaengineering.com NEXTMED PARKING STRUCTURE SWQM P OMA EXHIB IT CARLSBAD, CALIFORNIA PROJECT NUMBER: 3048 SCALE: 1" = 20' DATE: OCTOBER 2019 SHEET 1 OF 2 SITE SPECIFIC DATA PROJECT NUMBER ORDER NUMBER PROJECT NAME PROJECT LOCATION STRUCTURE ID TREATMENT REQUIRED VOLUME BASED {CF) FLOW BASED {CFS) TREATMENT HGL AVAILABLE (FT) PEAK BYPASS REQUIRED (CFS) -IF APPUCABLE PIPE DATA IE MATERIAL DIAM£TER INLET PIPE 1 INLET PIP[ 2 OUTLET PIPE PRETREATMENT BIOFILTRATION DISCHARGE RIM ELEVATION SURFACE LOAD PEDESTRIAN OPEN PLANTER PEDESTRIAN FRAME & COVER 24" X 42" N/A N/A WETLANDMEDIA VOLUME {CY) TBD ORIFICE SIZE {DIA. INCHES) TBD NOTES: PRELIMINARY NOT FOR CONSTRUCTION. VEGETATION~ f'.\ ~!, .(;·• ~ PLANT 'i, -. INSTALLATION NOTES 1. CONTRACTOR TO PROVIDE ALL LABOR, EQUIPMENT, MATERIALS AND INCIDENTALS REQUIRED TO OFFLOAD AND INSTALL THE SYSTEM AND APPURTENANCES IN ACCORDANCE WITH THIS DRAWING AND THE MANUFACTURERS SPECIFICATIONS, UNLESS OTHERWISE STATED IN MANUFACTURERS CONTRACT. 2. UNIT MUST 8£ INSTALLED ON LEV£L BASE MANUFACTURER RECOMMENDS A MINIMUM 6" LEVEL ROCK BASE UNLESS SPECIFIED BY THE PROJECT ENGINEER. CONTRACTOR IS RESPONSIBLE TO VERIFY PROJECT ENGINEERS RECOMMENDED BASE SPECIF/CATIONS. J. ALL PIPES MUST 8£ FLUSH WITH INSIDE SURFACE OF CONCRETE (PIPES CANNOT INTRUDE BEYOND FLUSH). INVERT OF OUTFLOW PIPE ESTABUSHMENT MEDIA MUST 8£ FLUSH WITH DISCHARGE CHAMBER FLOOR. ALL GAPS AROUND PIPES SHALL 8£ SEALED WATER TIGHT WITH A NON-SHRINK GROUT PER MANUFACTURERS STANDARD CONNECTION DETAIL AND SHALL MEET OR EXCEED REGIONAL PIPE CONNECTION STANDARDS. 4. CONTRACTOR TO SUPPLY AND INSTALL ALL EXTERNAL CONNECTING PIPES. 5. CONTRACTOR RESPONSIBLE FOR INSTALLATION OF ALL RISERS, MANHOLES, AND HATCHES. CONTRACTOR TO GROUT ALL MANHOLES AND HATCHES TO MATCH FINISHED SURFACE UNLESS SPECIFIED OTHERWISE 6. DRIP OR SPRAY IRRIGATION REQUIRED ON ALL UNITS WITH VEGETATION. 7. CONTRACTOR RESPONSIBLE FOR CONTACTING MODULAR WETLANDS FOR ACTIVATION OF UNIT. MANUFACTURES WARRANTY IS VOID WITH OUT PROPER ACTIVATION BY A MODULAR W£TIANDS REPRESENIATIVE. GENERAL NOTES 1. MANUFACTURER TO PROVIDE ALL MATERIALS UNLESS OTHERWISE NOTED. 2. ALL DIMENSIONS, ELEVATIONS, SPECIFICATIONS AND CAPACmEs ARE SUBJECT TO CHANGE FOR PROJECT SPECIFIC DRAWINGS DUA/UNG EXACT DIMENSIONS, W£/GHTS AND ACCESSORIES PLE<ISE CONTACT MANUFACTURER. LEFT END VIEW r, i\l ::-.J,_, t ?....--12. u, L kl::-_:S11:~0,~ t.: LANL-) 1HIS ffl«XICl MIi' l£ ffll11u;!l(} ffr (IE OR Jal£ (F1)£RilJJIINll£fllllIJaS,1,~1,4111,J6:!\, ;,;mm:4.l!MI'~ mAIS)fa/!JCI/Affll,'J$(JI/ W£TIANDM[l}JA BED PATENTED SITE CURBING BY OTHERS '1------l-+----£ P£mM£TER DRAIN DOWN UN£ 1~ <> t CURB OPENING PLAN VIEW C/L VOID ARE<! • -·' - 1-,·-o· FLOW CONTROL RISER l o ELEVATION VIEW PROPRIETARY AND CONFIDENTIAL: TH£ fNFORIIATION CONTAINED IN THIS DOC/JMENT IS THE SOI£ PROPEHlY OF FORT£RRA AND flS COIJPAN/ES. THIS OOCUAl£J{{, NOR ANY PAHT THfREOF, MAY BE /JSED, REPROfJUG£D OR IN ANY UANNER WllH OfJT THE WRf1T8I CONSENT OF ror?1EJ'ffeA. ,.-,,• .. ,-. ' <• ·-··\:·.-r-'<'.·-·.:, • "' RIGHT END VIEW TREATMENT FLOW (CFS) 0.052 OPERATING HEAD (FT) 3.4 PRETREATMENT LOADING RATE (GPM/SF) 1.8 WETLAND MEDIA LOADING RATE (GPM/SF) 1.0 MWS-L-4-4-C STORMWATER 8/0FILTRA T!ON SYSTEM STANDARD DETAIL MODULAR WETLANDS SYSTEM B/OFIL TRA TION DEVICE TYPICAL DETAIL Know what's below. Call before you dig. NOT TO SCALE PASCO LARET SUITER & ASSOCIATES CIVIL ENGINEERING+ LAND PLANNING+ LAND SURVEYING 535 North Highway 101, Suite A Solana Beach, CA 92075 ph 858.259.8212 I fx 858.259.48121 plsaengineering.com NEXTMED PARKING STRUCTURE SWQMP OMA EXHIBIT CARLSBAD, CALIFORNIA PROJECT NUMBER: 3048 SCALE: 1" = 20' DATE: OCTOBER 2019 SHEET 2 OF 2 Harvest and Use Feasibili 3048 NextMed Parking Garage 1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during the wet season? □ Toilet and urinal flushing v 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. Landscape Irrigation (0.1 ac irrigated) x (390 gal/ac-36hr) x (0.13368 cuft/gal) = 5.2 cuft/36hr 3. Calculate the DCV using worksheet B-2.1. DCV = 1,845 cuft 3a . Is the 36-hour demand greater than or equal to theDCV? Yes / v No 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. 3b . Is the 36-hour demand greater than 0.25DCV but less than the full DCV? Yes I v No 3c. Is the 36-hour demand less than 0.25DCV? v Yes Harvest and use may be feasible. Conduct v Harvest and use is more detailed evaluation and sizing considered to be infeasible. 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. Attachment 1 d .___-~-~~~~~lnfil~tratlonFeasiliilify Appendix I: Forms and Checklists Categorization of Infiltration Feasibility F 1 8 C d . . orm -on 1t1on Part 1 -Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated? Criteria Screening Question Yes No 1 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. Provide basis: - X Based on an as-graded report prepared by Geocon Incorporated dated January 12, 1999, the project area is underlain by compacted fill overlying undocumented fill and terrace deposits. Based on USDA Web Soil Survey, the property is underlain by Chesterton fine sandy loam. The Chesterton fine sandy loam is classified as having a Hydraulic Soil Group D. The estimated saturated hydraulic conductivity is 0.0 to 0.06 in/hr. The estimated reliable infiltration is less than 0.5 in/hr. 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: X Due to the presence of both compacted fill and undocumented fill on the property, infiltrating into the fills could cause soil settlement and distress to improvements. Additionally, the expected infiltration rate is significantly slow that we expect lateral water migration could occur which could cause differential soil movement and potential distress to down gradient improvements. Appendix I: Forms and Checklists Criteria 3 Form 1-8 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 - X Based on exploratory borings, groundwater is at a depth greater than 35 feet below existing grade. Infiltration is not expected to increase the risk of groundwater contamination. 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. X Provide basis: It is our opinion that infiltration should not cause water balance issues or increased discharge of contaminated groundwater to surface waters. 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 Engineer to substantiate findings - Appendix I: Forms and Checklists Form 1-8 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. Provide basis: Yes No X Based on USDA Web Soil Survey, the property is underlain by Chesterton fine sandy loam. The Chesterton fine sandy loam is classified as having a Hydraulic Soil Group D. The estimated saturated hydraulic conductivity is 0.0 to 0.06 in/hr. The estimated reliable infiltration is less than the typical 0.05 in/hr rate considered as the minimum value for partial infiltration. 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. Provide basis: X Due to the presence of both compacted fill and undocumented fill on the property, infiltrating into the fills could cause soil settlement and distress to improvements. Additionally, the expected infiltration rate is significantly slow that we expect lateral water migration could occur which could cause differential soil movement and potential distress to down gradient improvements. 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, stonn 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. Appendix I: Fonns and Checklists Yes No X Provide basis: Based on exploratory borings, groundwater is at a depth greater than 35 feet below existing grade. Infiltration is not expected to increase the risk of groundwater related concerns. 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. X Provide basis: Researching downstream water rights and evaluating water balance issues to stream flows is beyond the scope of the geotechnical engineer. However, it is our opinion that infiltration should not impact downstream water rights. 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 Part 2 Result* If all answers from row 5-8 are yes then partial infiltration design is potentially feasible. The feasibility screening category is Partial Infiltration. No If any answer from row 5-8 is no, then infiltration of any volume is considered to Infiltration be infeasible within the drainage area. The feasibility screening category is No Infiltration. *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 Engineer to substantiate findings. Attachment le ......._____~~-~~_BMP Design Worksheets I I I I San Diego County 85 th Percentile lsopluvials -850\ PERCENTil.E ISOP\.lMAL. D INCO<IPORATEDCITY NOTE __ _,.. • o 24 toourrw,fal .,._ I-o v.-lUCh-85" dlho -24 h0urrw,lal .,...Wlllbo IOU ,,.., ......... N + --oJll-~....or---,o,-~OCI, ..... ....... ca..._..~ ... lllOll..lilltfll'O~Ml'\a ~0,,~1•NC> ...... ..,..,.,,.~ t'l,#l0a --~----------9llli0l,0, -----------------~ ·-..... ------------·"""'---·~---"'--• _... .......... ,~ ··---·..-·-----------------------·~ ::::r~-... .:C."="-.._ ___ ..., __ _ LUEG ~GIS ==== Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Figure B.1-1: 85th Percentile 24-hour Isopluvial Map B-5 February 2016 3048 NextMed Parking Garage 10/23/2019 Appendix B: Stormwater Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.2-1. DCV 1 85th percentile 24-hr storm depth from Figure B.1-1 2 Area tributary to BMP (s) Area weighted runoff factor (estimate using Appendix B.1.1 and 3 B.2.1) * See calculation below 4 Street trees volume reduction 5 Rain barrels volume reduction (1 cubic foot=7.48 gallons) Calculate DCV = 6 (3630 x C x d x A) -TCV -RCV OMA B (BMP-2) 85th percentile 24-hr storm depth from Figure B.1-1 2 Area tributary to BMP (s) Impervious Landscape DG Total Area weighted runoff factor (estimate using Appendix B.1.1 and 3 B.2.1) * See calculation below 4 Street trees volume reduction 5 Rain barrels volume reduction (1 cubic foot=7.48 gallons) Calculate DCV = 6 (3630 x C x d x A) -TCV -RCV Impervious Landscape DG Total d= A= C= TCV= RCV= DCV= Area (sq ft) 9032 1523 0 10555 A= C= TCV= RCV= DCV= Area (sq ft) 24724 2407 0 27131 0.57 inches 0.22 acres 0.84 unitless 0 cubic-feet 0 cubic-feet 382 cubic-feet Runoff Factor Ax RF 0.9 8128.8 0.1 152.3 0.3 0 8281 0.62 acres 0.83 unitless 0 cubic-feet 0 cubic-feet 1065 cubic-feet Runoff Factor Ax RF 0.9 22251.6 0.1 240.7 0.3 0 22492 Weighted RF 0.78 Weighted RF 0.83 3048 NextMed Parking Garage 10/23/2019 Appendix B: Stormwater Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.2-1. DCV 1 2 3 4 5 6 85th percentile 24-hr storm depth from Figure B.1-1 Area tributary to BMP (s) Area weighted runoff factor (estimate using Appendix B.1.1 and B.2.1) * See calculation below Street trees volume reduction Rain barrels volume reduction (1 cubic foot=7.48 gallons) Calculate DCV = (3630 x C x d x A)-TCV -RCV Impervious Landscape DG Tota I d= A= C= TCV= RCV= DCV= Area (sq ft) 9032 458 0 9490 0.57 inches 0.22 acres 0.86 unitless 0 cubic-feet 0 cubic-feet 391 cubic-feet Runoff Factor Ax RF 0.9 8128.8 0.1 45.8 0.3 0 8175 Weighted RF 0.86 3048 NextMed Parking Garage 10/23/2019 DMA A {BMP-1} Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs 1 Remaining DCV After implementing retention BMPs 765.0 cu-ft Partial Retention 2 Infiltration rate from Worksheet D.5-1 if partial infiltration is feasible 0.00 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] 0.00 inches 5 Aggregate pore space 0.40 in/in 6 Required depth of gravel below the underdrain [Line 4 / Line 5] 0.00 inches 7 Assumed surface area of the biofiltration BMP 1100.0 sq-ft 8 Media retained pore storage 0.1 in/in 9 Volume retained pore storage 165.00 cu-ft 10 DCV that requires biofiltration (Line 1 -Line 9] 600.0 cu-ft BMP Parameters 11 Surface Ponding (6 inch minimum, 12 inch maximum] 12 inches 12 Media Thickness (18 in Min], also add mulch layer thicknes to this line 18 inches 13 Aggregate Storage above underdrain inver (12 inches typical) -Use O inches for 12 inches sizing if the aggregate is not over the entire bottom surface area 14 Freely drained pore storage 0.2 in/in Media filtration rate to be used for sizing (5 in/hr. with no outlet control; if the 15 filtration rate is controlled by the outlet, use the outlet controlled rate which 0.941 in/hr will be less than 5 in/hr.) Baseline Calculations 16 Allowable Routing Time for sizing 6 hours 17 Depth filtered during storm [Line 15 x Line 16] 6 inches Depth of Detention Storage 20.40 inches 18 [Line 11 + (Line 12 x Line 14) + (Line 13 x Line 5)1 19 Total Depth Treated [Line 17 + Line 18] 26.05 inches Option 1 -Biofilter 1.5 times the DCV 20 Required biofiltered volume [1.5 x Line 10] 900 cu-ft 21 Required Footprint [Line 20 / Line 19] x 12 414.7 sq-ft Option 2 -Store 0.75 of remaining DCV in pores and poding 22 Required Storage (surface+ pores) Volume [0.75 x Line 10] 450 cu-ft 23 Required Footprint [Line 22 / Line 18] x 12 265 sq-ft Footprint of the BMP 24 Area draining to the BMP 18994 sq-ft Adjusted Runoff Factor for drainage area 0.84 25 (Refer to Appendix B.l and B.2) 26 BMP Footprint Sizing Factor (Default 0.03 or an alternative minimum footprint 0.03 sizing factor from Worksheet B.5-2, Line 11) 27 Minimum BMP Footprint (Line 24 x Line 25 x Line 26] 479 sq-ft 28 Footprint of the BMP = Maximum (Minimum(Line 21, Line 23), Line 27) 479 sq-ft J:\Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\3048 WorksheetB-5.l_Biofiltration.xlsx 3048 NextMed Parking Garage 10/23/2019 OMA B {BMP-2) Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs 1 Remaining DCV After implementing retention 8MPs 1065.0 cu-ft Partial Retention 2 Infiltration rate from Worksheet D.5-1 if partial infiltration is feasible 0.00 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] 0.00 inches 5 Aggregate pore space 0.40 in/in 6 Required depth of gravel below the underdrain [Line 4 / Line SJ 0.00 inches 7 Assumed surface area of the biofiltration 8MP 1028.0 sq-ft 8 Media retained pore storage 0.1 in/in 9 Volume retained pore storage 154.20 cu-ft 10 DCV that requires biofiltration [Line 1 -Line 9] 910.8 cu-ft BMP Parameters 11 Surface Ponding [6 inch minimum, 12 inch maximum] 12 inches 12 Media Thickness [18 in Min], also add mulch layer thicknes to this line 18 inches 13 Aggregate Storage above underdrain inver (12 inches typical) -Use O inches for 12 inches sizing if the aggregate is not over the entire bottom surface area 14 Freely drained pore storage 0.2 in/in Media filtration rate to be used for sizing (S in/hr. with no outlet control; if the 15 filtration rate is controlled by the outlet, use the outlet controlled rate which 1.314 in/hr will be less than 5 in/hr.) Baseline Calculations 16 Allowable Routing Time for sizing 6 hours 17 Depth filtered during storm [Line 15 x Line 16] 8 inches Depth of Detention Storage 20.40 inches 18 [Line 11 + {Line 12 x Line 14) + (Line 13 x Line S)] 19 Total Depth Treated [Line 17 + Line 18] 28.28 inches Option 1 -Biofilter 1.5 times the DCV 20 Required biofiltered volume [1.5 x Line 10] 1366 cu-ft 21 Required Footprint [Line 20 / Line 19] x 12 579.6 sq-ft Option 2 -Store 0. 75 of remaining DCV in pores and poding 22 Required Storage (surface+ pores) Volume [0.75 x Line 10] 683 cu-ft 23 Required Footprint [Line 22 / Line 18] x 12 402 sq-ft Footprint of the BMP 24 Area draining to the 8MP 27131 sq-ft Adjusted Runoff Factor for drainage area 0.83 25 {Refer to Appendix 8.1 and 8.2) 26 BMP Footprint Sizing Factor (Default 0.03 or an alternative minimum footprint sizing factor from Worksheet 8.5-2, Line 11) 0.03 27 Minimum 8MP Footprint [Line 24 x Line 25 x Line 26] 676 sq-ft 28 Footprint of the 8MP = Maximum (Minimum{Line 21, Line 23), Line 27) 676 sq-ft J:\Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\3048 WorksheetB-S.1_8iofiltration.xlsx Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B.6.3 Sizing Flow-Thru Treatment Control BMPs: Use for Sizing Proprietary Biofiltration BMP Q=C x i x A Where: Q = Design flow rate in cubic feet per second C = Runoff factor, area-weighted estimate using Table 8.1-1. i = Rainfall intensity of 0.2 in/hr. A= Tributary area (acres) which includes the total area draining to the 8MP, including any offsite or onsite areas that comingle with project runoff and drain to the 8MP. Worksheet B.6-1: Flow-Thru Design Flows DCV requiring flow-thru Design rainfall intensity Area tributary to 8MP (s) Area-weighted runoff factor (estimate using Appendix 8.2 Calculate Flow Rate = C x i x A ocvflow-thru i= A= C= Q= 391 cubic-feet 0.20 in/hr 0.22 acres 0.86 unitless 0.038 cfs -... .. ... PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 -.. ATTACHMENT 2 BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES -Attachment Contents Checklist .. Seauence Attachment 2a Hydromodification Management ~ Included (Project is exempt from .. Exhibit (Required) Hydromodification Control Requirements) .. Attachment 2b Management of Critical Coarse ~ Exhibit showing project -Sediment Yield Areas (WMAA drainage boundaries marked Exhibit is required, additional on WMM Critical Coarse -analyses are optional) Sediment Yield Area Map See Section 6.2 of the BMP Design (Required) -Manual. Optional analyses for Critical Coarse Sediment Yield Area Determination □ 6.2.1 Verification of Geomorphic Landscape Units Onsite -□ 6.2.2 Downstream Systems Sensitivity to Coarse Sediment □ 6.2.3 Optional Additional Analysis -of Potential Critical Coarse Sediment Yield Areas Onsite .. .. Attachment 2c Geomorphic Assessment of ~ Not performed Receiving Channels (Optional) □ Included • See Section 6.3.4 of the BMP -Desian Manual. .. Attachment 2d Flow Control Facility Design and ~ Included Structural BMP Drawdown Calculations (Required) -See Chapter 6 and Appendix G of the BMP Desian Manual - • • .. .. .. .. NEXTMED PARKING STRUCTURE ... 25 - Attachment 2a __ H_ydromodification Man ement Exhibff I I I I 0 / o> rr:!x / I " / _,,_ ---~- / /-- . ./ '/ STRUCTURE ROOF" DRAIN * INTO RIBBON GUTTER TO BMP ~~v // 7--/ / / / ~ / /; / 4' / I / ~ ' • / / ~~~ / ~ / \ / / ,,\ / / "' ~r-~ / [ "' ·'> \ I I (f) s--.._ s -f-G . _, 0 ,_ ,--J 20' 10· 0 20' 40' 1-~ I I SCALE: 1" = 20' / PLAN VIEW -OMA AREAS SCALE: 7" = 20' Know what's below. Call before you dig. LEGEND PROPOSED STORM DRAIN EXISllNG STORM DRAIN PROPOSED HARDSCAPE/ IMPERVIOUS AREA PROPOSED LANDSCAPING/ PEFIVIOUS AREA DRAINAGE MANAGEMENT [///////////////! ~~ AREA (OMA) BOUNDARY TREATMENT CONTROL BMP NUMBER SURFACE R.OW DIRECTION ARROW STORM DRAIN (SUBSURFACE) R.OW DIRECTION ARROW PONT OF COMPLIANCE TREATMENT CONTROL BMPS BIOFIL TRA TION WITH IMPERMEABLE LINER SOIL INFORMATION SO/l.., TYPED DEPTH TO GROUNDWATER SEE SOILS REPORT SITE INFORMATION: IMPERVIOUS AREA, PERVIOUS AREA= TOTAL DISTURBED AREA: 85TH PERCENTILE STORM DEPTH: 1.23AC 0.16AC 1.09 AC 0.57 in OMA SUMMARY DRA INA GE IMPERVIOUS MANAGEMEN T BMP TYPE AREA (AC) AREA (OMA) 1 (A ,C,D,E,F) BIOFIL TRA TION 20,524 (0.47) 2 (B,G) BIOF/L TRA TION 26,101 (0.60) PERVIOUS TOTAL AREA AREA (AC) (ACRES) 3,724 (0.09) 24,248 (0.56) 2,407 (0.055) 28,508 (0.65) BIOFIL TRATION BMP SUMMARY BMP ID BMP TYPE REQUIRED BMP PROVIDED BMP AREA (SF) AREA (SF) 1 BIOFIL TRA T/ON 1100 1101 2 BIOFIL TRA T/ON 1028 1028 PASCO LARET SUITER & ASSOCIATES NEXTM ED PARK IN G STRUCTURE HYDROMODIFICATION EXH IBIT CIVIL ENGINEER ING+ LAND PLAN NI NG+ LAND SU RVEY ING 535 North Highway 101, Suite A So lana Beach, CA 92075 ph 858.259.8212 I fx 858.259.4812 I plsaengineering.com CARLSBAD, CALIFORNIA PROJECT NUMBER: 3048 SCALE: 1" "' 20' DATE: AUGUST 2019 SHEET 1 OF 1 Attachment 2b Potential Critical Course Sediment Yield Areas Exhibit Potential Critical Coarse Sediment Yield Areas Regional San Diego County Watersheds Source: 2015 Regional Potential Critical Coarse Sediment Yield Area Mapping Google Earth kmz file from www.projectcleanwater.org Attachment 2 Flow Control and BMP Drawdown Calculations 3048 NextMed Parking Garage 5/15/2019 PRE-PROJECT MODEL Oceanside 121 DMA-1 1111 ' ' 'POC-1 .. SWMM MODEL SCHEMATICS POST-PROJECT MODEL Oceanside 12] DMA-A "' OMA-C.0,E,F,G • ', ', BMP-1 111111 ', '' ', ', ' '-:-,.POe-1 J :\Active Jobs\3048 N EXTM ED PARKING\CIVIL \REPORTS\SWQM P\SWM M\Output\3048 _SWM M_Schematics.xlsx OMA-B JIii BMP-2 • ,' II 1111 II It II If I I It II II 11 II II It 11 II 11 II 3048 NextMed Parking Garage 8/8/2019 PRE-PROJECT Width (Area/Flow OMA Area (ac) Length) (ft) 1 1.21 314 Total: 1.21 POST-PROJECT Width (Area/Flow DMA Area (ac) Length) (ft) A 0.41 254 B 0.60 276 C, D, E, F, G 0.15 307 BMP-1 0.02525 33 BMP-2 0.02360 31 Total: 1.21 Conductivity: D:I o.025lin/hr % Slope 1.3% % Impervious 97% 95% 66% 0% 0% POC-1 Weighted % %"0" Conductivity Impervious % "C" Soils Soils (in/hr): 0% 0% 100% 0.025 Weighted %"0" Conductivity % Slope % "C" Soils Soils (in/hr): 1.0% 0% 100% 0.025 1.0% 0% 100% 0.025 1.0% 0% 100% 0.025 0.0% 0% 100% 0.025 0.0% 0% 100% 0.025 Suction Head: 0:1 9lin J:\Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\3048_SWMM_lnput_Alt3.xlsx Weighted Weighted Suction Initial Head (in): Deficit: 9.000 0.330 Weighted Weighted Suction Initial Head (in): Deficit: 9.000 0.330 9.000 0.330 9.000 0.330 9.000 0.330 9.000 0.330 Initial Deficit D:I 0.33 I I I I I 1 I I I '1 I 1 I ' ' 1 I I I I f I I 1 I I I I I I I I I I I I I I POC-1 [TITLE] ;;Project Title/Notes 3048 NextMed Parking Pre-Project Condition [OPTIONS] ;;Option Value FLOW UNITS CFS INFILTRATION GREEN AMPT FLOW ROUTING KINWAVE LINK OFFSETS DEPTH MIN SLOPE 0 ALLOW PONDING NO SKIP STEADY STATE NO -- START DATE 08/28/1951 START TIME 05:00:00 REPORT START DATE 08/28/1951 --REPORT START TIME 05:00:00 --END DATE 05/23/2008 END TIME 23:00:00 SWEEP START 01/01 SWEEP END 12/31 DRY DAYS 0 REPORT STEP 01:00:00 WET STEP 00:15:00 DRY STEP 04:00:00 ROUTING STEP 0:01:00 RULE STEP 00:00:00 INERTIAL DAMPING PARTIAL NORMAL FLOW LIMITED BOTH FORCE_MAIN_EQUATION H-W VARIABLE STEP 0.75 LENGTHENING STEP 0 MIN SURFAREA 12.557 MAX TRIALS 8 HEAD TOLERANCE 0.005 SYS FLOW TOL 5 LAT FLOW TOL 5 MINIMUM STEP 0.5 THREADS 1 [EVAPORATION] ;;Data Source Parameters '' MONTHLY .03 .05 .08 .11 .13 .15 .15 .13 .11 .08 .04 .02 DRY ONLY NO [ RAINGAGES] ; ;Name Format Interval SCF Source I I I I I I I I I I I l I !. I I I I I 1 I I I I I POC-1 ··---------------------------------------------'' Oceanside INTENSITY 1:00 1.0 TIMESERIES Oceanside [SUBCATCHMENTS] ; ;Name Rain Gage Outlet Area %Imperv Width %Slope CurbLen ··---------------------------------------------------------------------------'' DMA-1 [SUBAREAS] ;;Subcatchment DMA-1 [INFILTRATION] ;;Subcatchment DMA-1 [OUTFALLS] ; ;Name ;Basin 1 POC-1 [TIMESERIES] ; ;Name Oceanside POC-1 N-Imperv N-Perv S-Imperv 0.012 0.056 0.05 Suction Ksat IMD ----------------------- 9 .025 .33 Elevation Type Stage Data ------------------------ 0 FREE Date Time Value ------------------------- 1. 21 0 314 1. 3 S-Perv PctZero RouteTo 0.1 25 OUTLET Gated Route To NO 0 PctRouted I I I SnowPack Oceanside FILE "J: \Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\Rainfall\oceanside.dat" [REPORT] ;;Reporting Options SUBCATCHMENTS ALL NODES ALL LINKS ALL [TAGS] [MAP] DIMENSIONS 0.000 0.000 10000.000 10000.000 Units None [COORDINATES] ; ;Node POC-1 [VERTICES] ; ;Link . ·--------------'' [Polygons] X-Coord Y-Coord 1000.000 2500.000 X-Coord Y-Coord I ' I • I I I I I I I 1 I I I I I I I I I I I ' I I I I I I I I I I I I I I I I I I I I I I I I POC-1 ;;Subcatchment X-Coord Y-Coord , , DMA-1 663.017 4914.842 [SYMBOLS] ; ;Gage X-Coord Y-Coord ,, Oceanside 747.985 6731.113 I I I I I I I I I I I 1 I ' I I I I I I I I I I I I I I I I I I I I I • I I POC-1 ;;Project Title/Notes 3048 NextMed Parking Post-Project Condition [OPTIONS] ; ;Option Value FLOW UNITS CFS INFILTRATION GREEN AMPT FLOW ROUTING KINWAVE LINK OFFSETS DEPTH MIN SLOPE 0 ALLOW PONDING NO SKIP STEADY STATE NO -- START DATE 08/28/1951 START TIME 05:00:00 REPORT START DATE 08/28/1951 REPORT START TIME 05:00:00 --END DATE 05/23/2008 END TIME 23:00:00 SWEEP START 01/01 SWEEP END 12/31 DRY DAYS 0 REPORT STEP 01:00:00 WET STEP 00:15:00 DRY STEP 04:00:00 ROUTING STEP 0:01:00 RULE STEP 00:00:00 INERTIAL DAMPING PARTIAL NORMAL FLOW LIMITED BOTH FORCE_MAIN_EQUATION H-W VARIABLE STEP 0.75 LENGTHENING STEP 0 MIN SURFAREA 12.557 MAX TRIALS 8 HEAD TOLERANCE 0.005 SYS FLOW TOL 5 LAT FLOW TOL 5 MINIMUM STEP 0.5 THREADS 1 [EVAPORATION] ;;Data Source Parameters ;,------------------------------ MONTHLY .03 .05 . 08 .11 .13 .15 .15 .13 .11 .08 .04 .02 DRY ONLY NO [RAINGAGES] ; ;Name Format Interval SCF Source . ·---------------------------------------------'' I I I I I I I I I I I I I I I I t I I I I I I I I I I I I I POC-1 Oceanside INTENSITY 1: 00 1.0 TIMESERIES Oceanside [ SUBCATCHMENTS] ; ;Name Rain Gage Outlet Area %Imperv Width %Slope CurbLen SnowPack ,;---------------------------------------------------------------------------------------------- OMA-A Oceanside BMP-1 0.41 DMA-B Oceanside BMP-2 0.6 BMP-1 Oceanside POC-1 0.02525 BMP-2 Oceanside POC-1 0.02360 DMA-C,D,E,F,G Oceanside POC-1 0.15 [SUBAREAS] ;;Subcatchment N-Imperv N-Perv S-Imperv S-Perv ··------------------------------------------------------'' DMA-A 0.012 0.06 0.05 DMA-B 0.012 0.06 0.05 BMP-1 0.012 0.06 0.05 BMP-2 0.012 0.06 0.05 DMA-C,D,E,F,G 0.012 0.06 0.05 [INFILTRATION] ;;Subcatchment Suction Ksat IMD ··--------------------------------------------', DMA-A 9 .025 .33 DMA-B 9 .025 .33 BMP-1 9 .025 .33 BMP-2 9 .025 .33 DMA-C,D,E,F,G 9 .025 .33 [LID_ CONTROLS] ; ;Name Type/Layer Parameters ,, ----------------------------- BMP-1 BMP-1 BMP-1 BMP-1 BMP-1 BMP-2 BMP-2 BMP-2 BMP-2 BMP-2 [LID_USAGE] ;;Subcatchment FromPerv -------------- BMP-1 0 BC SURFACE SOIL STORAGE DRAIN BC SURFACE SOIL STORAGE DRAIN LID Process BMP-1 12 18 12 0.1459 12 18 12 0.2039 0 0.4 0.67 0.5 0 0.4 0.67 0.5 Number Area 1 1099.89 0.1 0.1 0.1 0.1 0.1 0 0.2 0 0 0 0.2 0 0 Width 0 97 254 95 276 0 33 0 31 66 307 PctZero 25 25 25 25 25 0 0.1 0 6 0 0.1 0 6 InitSat 0 1 0 1 0 0 0 0 0 1 0 RouteTo PctRouted OUTLET OUTLET OUTLET OUTLET OUTLET 5 5 0 5 5 0 Fromimp 100 5 0 5 0 ToPerv 0 1.5 1. 5 RptFile * I I I I I I I I DrainTo * I I I I I I I I I I I • I I I I I I I I I I I I I I I I POC-1 BMP-2 BMP-2 1 1028.02 0 0 100 0 * 0 [OUTFALLS] ; ;Name Elevation Type Stage Data Gated Route To ··--------------------------------------------------------------------------'' ;Basin 1 POC-1 0 FREE NO [TIMESERIES] ;;Name Date Time Value ;;-------------------------------------------- Oceanside FILE "J:\Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\Rainfall\oceanside.dat" [REPORT] ;;Reporting Options SUBCATCHMENTS ALL NODES ALL LINKS ALL [TAGS] [MAP] DIMENSIONS 0.000 0.000 10000.000 10000.000 Units None [COORDINATES] ; ;Node POC-1 [VERTICES] ; ; Link -------------- [Polygons] ;;Subcatchment X-Coord Y-Coord 1000.000 2500.000 X-Coord Y-Coord X-Coord Y-Coord ;;-------------------------------------------------- OMA-A 192.712 5074.214 DMA-B 1886.012 5048. 712 DMA-B 1886.012 5048. 712 DMA-B 1835.887 4986.055 BMP-1 225.564 3796. 992 BMP-2 1842.105 3809.524 DMA-C,D,E,F,G -697.542 4031. 406 [SYMBOLS] ;;Gage X-Coord Y-Coord ;;-------------------------------------------------- Oceanside 996.815 5959.681 I I • I I I I I I I * I I I I I 1 I I I I I I I 1 I I I I I I I I SWMM OUTPUT REPORT PRE-PROJECT CONDITION EPA STORM WATER MANAGEMENT MODEL -VERSION 5.1 (Build 5.1.013) 3048 NextMed Parking Pre-Project Condition ********************************************************* NOTE: The summary statistics displayed in this report are based on results found at every computational time step, not just on results from each reporting time step. ********************************************************* **************** Analysis Options **************** Flow Units ............... CFS Process Models: Rainfall/Runoff ........ YES RDII ................... NO Snowmelt ............... NO Groundwater ............ NO Flow Routing ........... NO Water Quality .......... NO Infiltration Method ...... GREEN AMPT Starting Date ............ 08/2871951 05:00:00 Ending Date .............. 05/23/2008 23: 00: 00 Antecedent Dry Days ...... 0.0 Report Time Step ......... 01:00:00 Wet Time Step ............ 00:15:00 Dry Time Step ............ 04:00:00 ************************** Runoff Quantity Continuity ************************** Total Precipitation ..... . Evaporation Loss ........ . Infiltration Loss ....... . Surface Runoff .......... . Final Storage ........... . Continuity Error (%) ************************** Flow Routing Continuity ************************** Dry Weather Inflow Wet Weather Inflow ...... . Groundwater Inflow ...... . RDII Inflow ............. . External Inflow ......... . External Outflow ........ . Flooding Loss ........... . Volume acre-feet 68.072 1. 540 52.879 14. 596 0.000 -1. 38 6 Volume acre-feet 0.000 14. 596 0.000 0.000 0.000 14. 596 0.000 Depth inches 675.090 15.275 524.417 144.757 0.000 Volume 10~6 gal 0.000 4.756 0.000 0.000 0.000 4.756 0.000 I I I I I I I I J:\Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\Output\3048_PreProject_SWMM_results.docx I t I I I I I I I I I I I I I I I I SWMM OUTPUT REPORT Evaporation Loss ........ . Exfiltration Loss ....... . Initial Stored Volume ... . Final Stored Volume ..... . Continuity Error (%) ••••• *************************** Subcatchment Runoff Summary *************************** I I Total Precip Subcatchment in DMA-1 675.09 t I 0.000 0.000 0.000 0.000 0.000 Total Runon in 0.00 Analysis begun on: Thu Aug 8 09:54:10 2019 Analysis ended on: Thu Aug 8 09:54:20 2019 Total elapsed time: 00:00:10 I 1 I I I I I I PRE-PROJECT CONDITION 0.000 0.000 0.000 0.000 Total Total Imperv Evap Infil Runoff in in in 15.28 524.42 0.00 I I I I I I I I I I I I Perv Total Total Peak Runoff Runoff Runoff Runoff Runoff Coeff in in 10A6 gal CFS -------------------------- 144.76 144.76 4.76 1. 36 0.214 J:\Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\Output\3048_PreProject_SWMM_results.docx I I I I I I I I I I I I I I I I I I I I I I I I I I SWMM OUTPUT REPORT POST-PROJECT CONDITION EPA STORM WATER MANAGEMENT MODEL -VERSION 5.1 (Build 5.1.013) 3048 NextMed Parking Post-Project Condition ********************************************************* NOTE: The summary statistics displayed in this report are based on results found at every computational time step, not just on results from each reporting time step. ********************************************************* **************** Analysis Options **************** Flow Units ............... CFS Process Models: Rainfall/Runoff ........ YES RDII ................... NO Snowmel t ............... NO Groundwater ............ NO Flow Routing ........... NO Water Quality .......... NO Infiltration Method ...... GREEN AMPT Starting Date ............ 08/2871951 05:00:00 Ending Date .............. 05/23/2008 23:00:00 Antecedent Dry Days ...... 0.0 Report Time Step ......... 01:00:00 Wet Time Step ............ 00:15:00 Dry Time Step ............ 04:00:00 ************************** Runoff Quantity Continuity ************************** Initial LID Storage ..... . Total Precipitation ..... . Evaporation Loss ........ . Infiltration Loss ....... . Surface Runoff .......... . LID Drainage ............ . Final Storage ........... . Continuity Error (%) ************************** Flow Routing Continuity ************************** Dry Weather Inflow Wet Weather Inflow ...... . Groundwater Inflow ...... . RDII Inflow ............. . External Inflow ......... . Volume acre-feet 0.007 68.007 9.978 3. 986 8.789 46.228 0.014 -1.442 Volume acre-feet 0.000 55.016 0.000 0.000 0.000 Depth inches 0.073 675.090 99.054 39.564 87.244 458.891 0.144 Volume 10A6 gal 0.000 17.928 0.000 0.000 0.000 I I I I I I I I J:\Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\Output\3048 PostProject SWMM_results.docx I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I SWMM OUTPUT REPORT POST-PROJECT CONDITION External Outflow ......... 55.016 17.928 Flooding Loss ............ 0.000 0.000 Evaporation Loss ......... 0.000 0.000 Exfiltration Loss ........ 0.000 0.000 Initial Stored Volume • ■ •• 0.000 0.000 Final Stored Volume ...... 0.000 0.000 Continuity Error (%) ..... 0.000 *************************** Subcatchment Runoff Summary *************************** ------------------------------- Total Total Total Total Imperv Perv Total Total Peak Precip Runon Evap Infil Runoff Runoff Runoff Runoff Runoff Subcatchment in in in in in in in 10A6 gal CFS ---------------------------------------------------------------------------------- DMA-A 675.09 0.00 78.88 15.36 586.23 4.93 591.16 6.58 0.49 DMA-B 675.09 0.00 78.02 25.62 573.17 8.14 581. 31 9.47 0. 72 BMP-1 67 5. 09 9598.92 646.35 0.00 0.00 0.00 9626. 71 6.60 0.52 BMP-2 675.09 14778.85 67 4. 11 0.00 0.00 0.00 14778.54 9.47 0.75 DMA-C,D,E,F,G 675.09 0.00 55.74 174.37 400.70 54.95 455.65 1. 86 0.18 *********************** LID Performance Summary *********************** ------------------------------------------------------------------------------------------------------------- Total Evap Infil Surface Drain Initial Final Continuity Inflow Loss Loss Outflow Outflow Storage Storage Error Subcatchment LID Control in in in in in in in % -------------------------------------------------------------------------------------------------------------------- BMP-1 BMP-1 BMP-2 BMP-2 Analysis begun on: Thu Aug Analysis ended on: Thu Aug Total elapsed time: 00:00:12 10274.01 15453.94 8 10:01:50 2019 8 10:02:02 2019 646.37 674.13 0.00 324. 11 9302.95 1.80 2.45 0.00 1226.05 13552. 97 1.80 2. 72 J:\Active Jobs\3048 NEXTMED PARKING\CIVIL\REPORTS\SWQMP\SWMM\Output\3048 PostProject SWMM_results.docx -0.00 -0.00 I I I I i I Runoff Coeff 0.876 0.861 0.937 0.956 0.675 Peak Flow Frequency Summary Return Period Pre-project Qpeak Post-project -Mitigated Q (cfs) {cfs) LF = 0.l xQ2 0.065 0.038 2-year 0.646 0.381 5-year 0.818 0.604 10-year 1.031 0.854 J :\Active Jobs\3048 NEXTM ED PARKING\CIVI L \REPORTS\SWQM P\SWM M\3048 SWMM _PostProcessing_Alt3.xlsx Peak Flow Frequency Curves 1.200 1.000 I I ' I I ' 0 800 I • I I l I I i I I . ' ' . I I I I I I I I j I ~4]1 q::: ' ~ -l . -11 ;_;,-111 I ' "' "t ·= ~ 0.600 I I I ..dJD' I I I J ~ 6 t! . I -0-Pre-project Qpeak .:,t, Ill QI n. 0.400 I al 0.200 -J-!11-'-- 0.000 -l!IJ__..__.., _ __,.--~--r--~~_,_-_..__..__~ --~~---~---- 0 1 2 3 4 5 Return Period in Years -tr-Post-project Mitigated Qpeak 6 7 8 9 10 Low-flow Threshold:~ 10% II 0.lxQ2 (Pre): 0.065 cfs Ql0(Pre): 1.031 cfs Ordinate#: 100 Incremental Q (Pre): 0.00966 cfs Total Hourly Data:I! 497370 jjhours The proposed BMP:! PASSED Interval Pre-project Flow Pre-project Hours Pre-project % Post-project Post-project % Percentage Pass/Fall (ds) Time Exceeding Hours Time Exceeding 0 0.065 888 l .79E-03 794 1.60E-03 89% Pass 1 0.074 795 1.60E-03 555 1.12E-03 70% Pass 2 0.084 730 l.47E-03 418 8.40E-04 57% Pass 3 0.094 669 1.35E-03 330 6.63E-04 49% Pass 4 0.103 626 1.26E-03 270 5.43E-04 43% Pass 5 0.113 580 1.17E-03 229 4.60E-04 39% Pass 6 0.123 553 1.llE-03 196 3.94E-04 35% Pass 7 0.132 518 l.04E-03 184 3.70E-04 36% Pass 8 0.142 490 9.85E-04 165 3.32E-04 34% Pass 9 0.152 458 9.21E-04 151 3.04E-04 33% Pass 10 0.161 435 8.75E-04 145 2.92E-04 33% Pass 11 0.171 404 8.12E-04 138 2.77E-04 34% Pass 12 0.181 374 7.52E-04 121 2.43E-04 32% Pass 13 0.190 351 7.06E-04 115 2.31E-04 33% Pass 14 0.200 327 6.57E-04 107 2.15E-04 33% Pass 15 0.210 292 5.87E-04 100 2.0lE-04 34% Pass 16 0.219 279 5.61E-04 96 1.93E-04 34% Pass 17 0.229 267 5.37E-04 92 l .85E-04 34% Pass 18 0.239 254 5.llE-04 81 l.63E-04 32% Pass 19 0.248 241 4.85E-04 72 l.45E-04 30% Pass 20 0.258 226 4.54E-04 69 1.39E-04 31% Pass 21 0.268 213 4.28E-04 66 1.33E-04 31% Pass 22 0.277 201 4.04E-04 63 1.27E-04 31% Pass 23 0.287 195 3.92E-04 61 1.23E-04 31% Pass 24 0.297 178 3.58E-04 58 1.17E-04 33% Pass 25 0.306 160 3.22E-04 56 l.13E-04 35% Pass 26 0.316 144 2.90E-04 55 l.llE-04 38% Pass 27 0.326 135 2.71E-04 55 1.llE-04 41% Pass 28 0.335 126 2.53E-04 47 9.45E-05 37% Pass 29 0.345 123 2.47E-04 45 9.05E-05 37% Pass 30 0.355 119 2.39E-04 42 8.44E-05 35% Pass 31 0.364 115 2.31E-04 39 7.84E-05 34% Pass 32 0.374 111 2.23E-04 38 7.64E-05 34% Pass 33 0.384 110 2.21E-04 35 7.04E-05 32% Pass 34 0.393 103 2.07E-04 33 6.63E-05 32% Pass 35 0.403 95 1.91E-04 31 6.23E-05 33% Pass 36 0.413 90 1.81E-04 30 6.03E-05 33% Pass 37 0.422 82 l .65E-04 30 6.03E-05 37% Pass 38 0.432 77 l .55E-04 30 6.03E-05 39% Pass 39 0.442 69 1.39E-04 30 6.03E-05 43% Pass 40 0.451 64 l .29E-04 26 5.23E-05 41% Pass 41 0.461 63 1.27E-04 26 5.23E-05 41% Pass 42 0.470 61 1.23E-04 26 5.23E-05 43% Pass 43 0.480 61 1.23E-04 25 5.03E-05 41% Pass 44 0.490 57 l .15E-04 20 4.02E-05 35% Pass 45 0.499 54 l.09E-04 20 4.02E-05 37% Pass 46 0.509 50 1.0lE-04 20 4.02E-05 40% Pass 47 0.519 48 9.65E-05 20 4.02E-05 42% Pass 48 0.528 47 9.45E-05 19 3.82E-05 40% Pass 49 0.538 46 9.25E-05 18 3.62E-05 39% Pass 50 0.548 43 8.65E-05 18 3.62E-05 42% Pass 51 0.557 42 8.44E-05 17 3.42E-05 40% Pass 52 0.567 41 8.24E-05 17 3.42E-05 41% Pass 53 0.577 41 8.24E-05 17 3.42E-05 41% Pass Interval Pre-project Flow Pre-project Hours Pre-project % Post-project Post-project % Percentage Pass/Fail (cfs) Time Exceeding Hours Time Exceeding 54 0.586 39 7.84E-05 15 3.02E-05 38% Pass 55 0.596 39 7.84E-05 15 3.02E-05 38% Pass 56 0.606 37 7.44E-05 12 2.41E-05 32% Pass 57 0.615 34 6.84E-05 12 2.41E-05 35% Pass 58 0.625 33 6.63E-05 12 2.41E-05 36% Pass 59 0.635 33 6.63E-05 12 2.41E-05 36% Pass 60 0.644 33 6.63E-05 12 2.41E-05 36% Pass 61 0.654 31 6.23E-05 11 2.21E-OS 35% Pass 62 0.664 29 S.83E-05 11 2.21E-OS 38% Pass 63 0.673 29 S.83E-05 11 2.21E-05 38% Pass 64 0.683 23 4.62E-05 11 2.21E-05 48% Pass 65 0.693 22 4.42E-05 11 2.21E-05 50% Pass 66 0.702 21 4.22E-05 11 2.21E-05 52% Pass 67 0.712 21 4.22E-05 10 2.0lE-05 48% Pass 68 0.722 21 4.22E-05 10 2.0lE-05 48% Pass 69 0.731 21 4.22E-05 9 1.81E-05 43% Pass 70 0.741 21 4.22E-05 9 1.81E-05 43% Pass 71 0.751 21 4.22E-05 9 1.81E-05 43% Pass 72 0.760 20 4.02E-05 9 l .81E-05 45% Pass 73 0.770 20 4.02E-05 9 1.81E-05 45% Pass 74 0.780 19 3.82E-05 9 l .81E-05 47% Pass 75 0.789 16 3.22E-05 9 l.81E-05 56% Pass 76 0.799 15 3.02E-05 9 l.81E-05 60% Pass 77 0.809 13 2.61E-05 9 l.81E-05 69% Pass 78 0.818 11 2.21E-05 9 l.81E-05 82% Pass 79 0.828 9 l .81E-05 9 l.81E-05 100% Pass 80 0.838 9 l.81E-05 8 1.61E-05 89% Pass 81 0.847 9 1.81E-05 6 1.21E-05 67% Pass 82 0.857 9 l.81E-05 6 l.21E-05 67% Pass 83 0.867 9 l .81E-05 6 l .21E-05 67% Pass 84 0.876 9 1.81E-05 5 1.0lE-05 56% Pass 85 0.886 8 1.61E-05 5 l .OlE-05 63% Pass 86 0.896 8 l .61E-05 4 8.04E-06 50% Pass 87 0.905 7 l.41E-05 4 8.04E-06 57% Pass 88 0.915 7 l.41E-05 4 8.04E-06 57% Pass 89 0.925 6 1.21E-05 4 8.04E-06 67% Pass 90 0.934 6 l.21E-05 4 8.04E-06 67%. Pass 91 0.944 6 1.21E-05 4 8.04E-06 67% Pass 92 0.954 6 l .21E-05 4 8.04E-06 67% Pass 93 0.963 6 1.21E-05 4 8.04E-06 67% Pass 94 0.973 6 1.21E-05 4 8.04E-06 67% Pass 95 0.983 6 l .21E-05 4 8.04E-06 67% Pass 96 0.992 6 l .21E-05 4 8.04E-06 67% Pass 97 1.002 6 1.21E-05 4 8.04E-06 67% Pass 98 1.012 6 l .21E-05 4 8.04E-06 67% Pass 99 1.021 5 l .OlE-05 4 8.04E-06 80% Pass 100 1.031 5 l .OlE-05 4 8.04E-06 80% Pass -"' -~ 3 0 u:: 1.200 1.000 0.800 0.600 0.400 0.200 0.000 l.0E-06 l.0E-05 Flow Duration Curve [Pre vs. Post (Mitigated)] l.0E-04 % Time Exceeding ~ Pre-project Q -6-Post-project (Mitigated) Q l.0E-03 l.0E-02 SWMM Model Flow Coefficient Calculation BMP-1 PARAMETER ABBREV. Bio-Retention Cell LID BMP Ponding Depth PD 12 in Bioretention Soil Layer s 18 in Gravel Layer G 12 in TOTAL 3.5 ft 42 in Orifice Coefficient Cg 0.6 Low Flow Orifice Diameter D 0.7 in Drain exponent n 0.5 Flow Rate (volumetric) Q 0.024 cfs Ponding Depth Surface Area Apo 1100 ft2 Bioretention Surface Area As.AG 1100 ft2 As.AG 0.0253 ac Porosity of Bioretention Soil n 1.00 Flow Rate (per unit area) q 0.942 in/hr Effective Ponding Depth PDen in Flow Coefficient C SWMM Model Flow Coefficient Calculation BMP-2 PARAMETER ABBREV. Bio-Retention Cell LID BMP Ponding Depth PD 12 in Bioretention Soil Layer s 18 in Gravel Layer G 12 in TOTAL 3.5 ft 42 in Orifice Coefficient Cg 0.6 Low Flow Orifice Diameter D 0.8 in Drain exponent n 0.5 Flow Rate (volumetric) Q 0.031 cfs Ponding Depth Surface Area Apo 1028 ft2 Bioretention Surface Area As.AG 1028 ft2 As.AG 0.0236 ac Porosity of Bioretention Soil n 1.00 Flow Rate (per unit area) q 1.315 in/hr Effective Ponding Depth PDett in Flow Coefficient C Date 5 l I 5 / ) ~ --___ .LJ .. __ _ PASCO LARET SUITER fj;J4~Ji~t::&;tt!{~~'i\ttitJ::4r'w & A S S O C I AT E S tJ e:x+ ~~ PO-ft-iv, 5 Job# 3D4-d' 535 North Highway 101 Ste A Solana Beach, C A 92075 I plsaengincering.com PASCO LARET SUIT;• R 'qte 0 _{_1_S )Ll) NtX+~d PO-./Lin5 Job# 3D4-j ' Drawdown Calculation for BMP-1 Project Name Project No Surface Drawdown Time: Surface Area Underdrain Orifice Diameter: in C: Surface Ponding (to invert of lowest surface discharge opening in outlet structure): Amended Soil Depth: Gravel Depth: Orifice Q = Effective Depth Infiltration controlled by orifice NextMed 3048 12.8 1100 0.7 0.6 1 1.5 1 0.024 20.4 0.941 hr sq ft in ft ft ft cfs in in/hr Drawdown Calculation for BMP-2 Project Name Project No Surface Drawdown Time: Surface Area Underdrain Orifice Diameter: in C: Surface Ponding (to invert of lowest surface discharge opening in outlet structure): Amended Soil Depth: Gravel Depth: Orifice Q = Effective Depth Infiltration controlled by orifice NextMed 3048 9.1 1028 0.8 0.6 1 1.5 1 0.031 20.4 1.314 hr sq ft in ft ft ft cfs in in/hr 33" 7CTN 33" 6'54"N ~ ,., Hydrologic Soil Group-San Diego County Area, California I I I i !il i !!: ~ ~ "' !!: ~ 4l\lR) 4l\lR) N A 470400 410W 4704«) 470400 4704lll 47IBXl 470400 -OOCIO 4704«) 470400 4704lll 411ml Map Salle: 1: 1,l(X) f ~ on A ~ ( 11' X 8.5") sheet. ----=====--------========Metes 0 ~ ~ 00 00 ----=====--------=========>fea 0 50 100 200 D'.l Map projedm: IM!b Mertalir Care-axmnates: WGS84 Edgeti:s: lJTM ZOne UN WGS84 USDA Natural Resources ~a Conservation Service Web Soil Survey National Cooperative Soil Survey 41$!J 41$!J 4llli40 471ml 47l!B) 47t8X) 4Jai«l 471ml 47l!B) 47t8X) ~ ~ !9 ~ ~ ~ !9 ~ I I I i !il i 9 i ~ i !,j i 1/24/2019 Page 1 of 4 33" 7 CTN 33" 6'54"N Hydrologic Soil Group-San Diego County Area, California MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons D A D AID D B D B/0 D C D CID D D D Not rated or not available Soil Rating Lines -A -AID -B -B/D C -CID -D ~ ,, Not rated or not available Soil Rating Points ■ A ■ AID ■ B ■ BID USDA Natural Resources -a Conservation Service C C ■ CID ■ D □ Not rated or not available Water Features Streams and Canals Transportation +++ ~ ~ Rails Interstate Highways US Routes Major Roads Local Roads Background • Aerial Photography Web Soil Survey National Cooperative Soil Survey The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: San Diego County Area, California Survey Area Data: Version 13, Sep 12, 2018 Soil map units are labeled (as space allows) for map scales 1 :50,000 or larger. Date(s) aerial images were photographed: Nov 3, 2014-Nov 22,2014 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 1/24/2019 Page 2 of 4 Hydrologic Soil Group-San Diego County Area, California Hydrologic Soil Group Map unit symbol Map unit name Rating Acres In AOI Percent of AOI ~ CfB Chesterton fine sandy D 2.6 loam, 2 to 5 percent slopes CfC Chesterton fine sandy D 0.5 loam, 5 to 9 percent slopes Totals for Area of Interest 3.1 -_.____ Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (ND, 8/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (ND, BID, or C/D}, the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 84.0% 16.0% 100.0% 1/24/2019 Page 3 of 4 Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing Factors 9 17 R V E R S S A N D I E G 0 16 111I 18 D E 16 IMPER I AL 18 nCINIIII t Figure G.1-2: California Irrigation Management Information System "Reference Evapotranspiration Zones" G-5 February 2016 Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing Factors Table G.1-1: Monthly Average Reference Evapotranspiration by ETo Zone (inches/month and inches/day) for use in SWMM Models for Hydromodification Management Studies in San Diego County CIMIS Zones 1, 4, 6, 9, and 16 (See CIMIS ETo Zone Map) Zone I in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month 0.93 1.4 2.48 3.3 4.03 4.5 4.65 4.03 3.3 2.48 1.2 0.62 4 1.86 2.24 3.41 4.5 5.27 5.7 5.89 5.58 4.5 3.41 2.4 1.86 6 1.86 2.24 3.41 4.8 5.58 6.3 6.51 6.2 4.8 3.72 2.4 1.86 9 2.17 2.8 4.03 5.1 5.89 6.6 7.44 6.82 5.7 4.03 2.7 1.86 16 I 1.55 I 2.52 I 4.03 5.7 7.75 8.7 9.3 8.37 6.3 4.34 2.4 1.55 March Octohcr November December January February April May June July August September Days I 31 I 28 31 30 31 30 31 31 30 31 I 30 I 31 ~ I I in/dav in ldav in/dav in/dav in ldav in/dav in/ dav in/dav in/da• 1 I 0.030 0.050 0.080 0.110 0.130 0.150 0.150 0.130 0.110 0.080 0.040 0.020 TI 4 0.060 0.080 0.110 0.150 0.170 0.190 0.190 0.180 0.150 0.110 0.080 0.060 6 0.060 0.080 0.110 0.160 0.180 0.210 0.210 0.200 0.160 0.120 0.080 0.060 9 0.070 0.100 0.130 0.170 0.190 0.220 0.240 0.220 0.190 0.130 0.090 0.060 16 I 0.050 0.090 0.130 0.190 0.250 0.290 0.300 0.270 0.210 0.140 0.080 I 0.050 G-6 February 2016 Attachment 3a BMP Maintenance Thresholds and BMP Fact Sheets "" .. .. .. .. ... .. ... -.. - • .. .. .. .. ... • .. -.. -.. .. PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 ATTACHMENT 3 Structural BMP Maintenance Information OWNERSHIP AND MAINTENANCE FOR STRUCTURAL BMPs The operations and maintenance of the treatment control BMPs will be the responsibility of the owner. The current contact information for the responsible party is: NextMed Ill, LLC 6125 Paseo Del Norte, Suite 210 Carlsbad, CA 92011 760-494-9216 A training program will be administered and implemented by NextMed Ill, LLC and shall occur at a minimum of once annually. The training program shall consist of, at a minimum: the disbursement of the brochures and flyers included in this SWQMP and a copy of the maintenance plan to all operation and maintenance staff associated with the project. A training log shall be filled out at each training session and kept for a minimum of five (5) years . NextMed Ill, LLC will complete and maintain operation and maintenance forms to adequately document all maintenance performed on the project's treatment control BMPs. These records should be kept on file for a minimum of five (5) years and shall be made accessible to the City of Carlsbad, the State Water Resources Control Board or any other authority regulating storm water discharges for inspection upon request at any time. All waste generated from the NextMed Parking Structure project site is ultimately the responsibility of NextMed Ill, LLC. Disposal of sediment, debris, and trash will comply with applicable local, county, state, and federal waste control programs. Suspected hazardous waste will be analyzed to determine proper disposal methods . The following Operation and Maintenance Plan has been developed for each type of pollutant control BMP used on this project. These are minimum requirements only. Their frequency and/or scope may be increased, if necessary, to meet and/or maintain the level of storm water quality treatment required of this project. All costs associated with the operation and maintenance of the pollutant control BMPs will be funded by NextMed Ill, LLC in perpetuity or until the project is sold to another entity where the responsibility would transfer with the sale of the property or an individual parcel. The project's owner, NextMed 111, LLC, will enter into a Stormwater Facility Maintenance Agreement as required by the City of Carlsbad, which will be executed prior to grading permit issuance. NEXTMED PARKING STRUCTURE 26 .. .. ... PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN NOVEMBER 2019 .. .. Biofiltration System Inspection Activities Recommended Frequency ... Inspect biofiltration system -Before/after rainy ... season .. -Bi-weekly during the rainy season .. -After a rainfall event of0.5" or more Inspect soil and repair eroded areas Monthly Inspect for erosion or damage to vegetation, preferably at the end of the wet .. season to schedule dry season maintenance and before major wet season Prior to rainy season runoff to be sure the areas are ready for the wet season. However, additional & every other month inspection after periods of heavy runoff is recommended. .. Inspect to ensure grasses, ground covers, vegetation is well established. If not, either prepare soil and reseed or replant with appropriate alternative species. .. Every other month Install erosion control blankets if necessary. -Check for debris and litter, areas of sediment accumulation Every other month Inspect health of trees and shrubs and vegetation Every other month Inspect system cleanouts and outfall structures Every other month ... Inspect for standing water and vectors Every other month • .. Biofiltration System Maintenance Activities Recommended Frequency • Remove litter and debris in conjunction with regularly scheduled landscape maintenance -Irrigate biofiltration area(s) during dry season (April through October) and as • necessary to maintain vegetation during the rainy season . .. Physically remove weeds Remove sediment As part of routine, .. Apply mulch to areas devoid of mulch, especially prior to the wet season regular landscape .. Replace damaged or diseased trees and shrubs maintenance Mow turf areas, if any • Repair erosion at inflow points ... Unclog under drain system Remove and replace dead and diseased vegetation .. Replace tree stakes and wires, if any • Mulch should be replaced every 2 to 3 years or when bare spots appear Every 2-3 years, or as needed .. Rototill or cultivate the surface if the system does not draw down in 48 hours As needed .. .. NEXTMED PARKING STRUCTURE 27 .. ... E.12 BF-1 Biofiltration Location: 43rd Street and Logan Avenue, San Diego, California Description Appendix E: BMP Design Fact Sheets MS4 Permit Category Bio filtration Manual Category Bio filtration Applicable Performance Standard Pollutant Control Flow Control Primary Benefits Treatment Volume Reduction (Incidental) Peak Flow Attenuation (Optional) Bio fil tration (Bioretention with underdrain) facilities are vegetated surface water systems that filter water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow to the downstream conveyance system. Bioretention with underdrain facilities are commonly incorporated into the site within parking lot landscaping, along roadsides, and in open spaces. Because these types of facilities have limited or no infiltration, they are typically designed to provide enough hydraulic head to move flows through the underdrain connection to the storm drain system. Treatment is achieved thro·ugh filtration, sedimentation, sorption, biochemical processes and plant uptake. Typical bioretention with underdrain components include: • Inflow distribution mechanisms (e.g, perimeter flow spreader or filter strips) • Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap) • Shallow surface ponding for captured flows • Side slope and basin bottom vegetation selected based on expected climate and ponding depth • on-floating mulch layer (Optional) • Media layer (planting mix or engineered media) capable of supporting vegetation growth • Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted native soils or the aggregate storage layer • Aggregate storage layer with underdrain(s) • Impermeable liner or uncompacted native soils at the bottom of the facility E-66 February 2016 Appendix E : BMP Design Fact Sheets • Overflow structure CURB CUT ·.·.·.·.~ APRON FOR ENERGY • •DISSIPATION ... + + + + • ... + + + ... + . : . : . : . : ~ ~ VEGETATED SIDE SLOPE PLAN NOTTO SCALE 4-6" DROP FROM CURB CUT TO APRON APRON FOR ENERGY DISSIPATION 6" MIN. TO 12" MAX. SURFACE PONDING CLEANOUT + + + + MAINTENANCE • ACCESS JAS ~EE,!)EDJ • .3H:1V(MIN.) • 3" WELL-AGED, SHREDDED HARDWOOD MULCH (OPTIONAL) MAINTENANCE ACCESS (AS NEEDED) , I ~i~!;,~~~.,.,,,,. ,,,, :_ --- ,-' ,r OVERFLOW EXCAVATED SLOP (SHOWN AT 1H:1 ,,/,/ , smocnm, MIN. 18" MEDIA WITH MIN. 5 IN/HR FILTRATION RATE SATURATED STORAGE (OPTIONAL) AGGREGATE STORAGE LAYER ~-"'~__._\ IMPERMEABLE LINER (OPTIONAL) MIN. 3" AGGREGATE BELOW UNDERDRAIN MIN. 6" DIAMETER UNDERDRAIN EXISTING UNCOMPACTED SOILS SECTION A-A' NOTTO SCALE Typical plan and Section view of a Biofiltration BMP E-67 February 2016 --------- ---.. --- -... --------------- -- Appendix E: BMP Design Fact Sheets Design Adaptations for Project Goals Biofiltration Treatment BMP for storm water pollutant control. The system is lined or un-lined to provide incidental infiltration, and an underdrain is provided at the bottom to carry away filtered runoff. This configuration is considered to provide biofiltration treatment via flow through the media layer. Storage provided above the underdrain within surface ponding, media, and aggregate storage is considered included in the biofiltration treatment volume. Saturated storage within the aggregate storage layer can be added to this design by raising the underdrain above the bottom of the aggregate storage layer or via an internal weir structure designed to maintain a specific water level elevation. Integrated storm water flow control and pollutant control configuration. The system can be designed to provide flow rate and duration control by primarily providing increased surface ponding and/ or having a deeper aggregate storage layer above the underdrain. This will allow for significant detention storage, which can be controlled via inclusion of an outlet structure at the downstream end of the underdrain. Design Criteria and Considerations Bioretention with underdrain must meet the following design criteria. Deviations from the below criteria may be approved at the discretion of the City Engineer if it is determined to be appropriate: Siting and Design □ □ □ Placement observes geotechnical recommendations regarding potential hazards (e.g., slope stability, landslides, liquefaction zones) and setbacks (e.g., slopes, foundations, utilities). An impermeable liner or other hydraulic restriction layer is included if site constraints indicate that infiltration or lateral flows should not be allowed. Contributing tributary area shall be :S 5 acres (:S 1 acre preferred). E-68 Intent/Rationale Must not negatively impact existing site geotechnical concerns. Lining prevents storm water from impacting groundwater and/ or sensitive environmental or geotechnical features. Incidental infiltration, when allowable, can aid in pollutant removal and groundwater recharge. ---------------. - Bigger BMPs require additional design features for proper performance. Contributing tributary area greater than 5 acres may be allowed at the discretion of the City Engineer if the following conditions are met: 1) incorporate design features (e.g. flow spreaders) to minimizing short circuiting of flows in ---· -·-----------------·-----· ---· ---------- February 2016 --------- ---.. --- ------------- -- -- Siting and Design □ Finish grade of the facility is :'.S 2%. ------------ Surface Ponding □ □ □ □ Surface ponding is limited to a 24-hour drawdown time. Surface ponding depth is 2 6 and :'.S 12 inches. A minimum of 2 inches of freeboard is provided. Side slopes are stabilized with vegetation and are= 3H:1V or shallower. Vegetation E-69 Appendix E: BMP Design Fact Sheets Intent/Rationale the BMP and 2) incorporate additional design features requested by the City Engineer for proper performance of the regional BMP. Flatter surfaces reduce erosion and channelization within the facility. ~----------··------~ --·------------~-- Surface ponding limited to 24 hours for plant health. Surface ponding drawdown time greater than 24-hours but less than 96 hours may be allowed at the discretion of the City Engineer if certified by a landscape architect or agronomist. Surface ponding capacity lowers subsurface storage requirements. Deep surface ponding raises safety concerns. Surface ponding depth greater than 12 inches (for additional pollutant control or surface outlet structures or flow- control orifices) may be allowed at the discretion of the City Engineer if the following conditions are met: 1) surface ponding depth drawdown time is less than 24 hours; and 2) safety issues and fencing requirements are considered (typically ponding greater than 18" will require a fence and/ or flatter side slopes) and 3) potential for elevated clogging risk is considered. ------- Freeboard provides room for head over overflow structures and minimizes risk of uncontrolled surface discharge. Gentler side slopes are safer, less prone to erosion, able to establish vegetation more quickly and easier to maintain. February 2016 ----------------- -------------------- --- Siting and Design. □ □ Plantings are suitable for the climate and expected ponding depth. A plant list to aid in selection can be found in Appendix E.20. An irrigation system with a connection to water supply should be provided as needed. Mulch (Optional) □ A minimum of 3 inches of well-aged, shredded hardwood mulch that has been stockpiled or stored for at least 12 months is provided. Media Layer □ □ Media maintains a minimum filtration rate of 5 in/hr over lifetime of facility. An initial filtration rate of 8 to 12 in/hr is recommended to allow for clogging over time; the initial filtration rate should not exceed 12 inches per hour. ------------- Media is a minimum 18 inches deep, meeting either of these two media specifications: City of San Diego Storm Water Standards Appendix F (February 2016, unless superseded by more recent edition) or County of San Diego Low Impact Development Handbook: Appendix G -Bioretention Soil Specification Oune 2014, unless superseded by more recent edition). Alternatively, for proprietary designs and custom media mixes not meeting the media specifications contained in the 2016 City of San Diego Storm Water Standards or County LID Manual, the media meets the pollutant treatment performance criteria in Section F.1. E-70 Appendix E: BMP Design Fact Sheets Intent/Rationale Plants suited to the climate and ponding depth are more likely to survive. Seasonal irrigation might be needed to keep plants healthy. Mulch will suppress weeds and maintain moisture for plant growth. Aging mulch kills pathogens and weed seeds and allows the beneficial microbes to multiply. ----------- A filtration rate of at least 5 inches per hour allows soil to drain between events. The initial rate should be higher than long term target rate to account for clogging over time. However an excessively high initial rate can have a negative impact on treatment performance, therefore an upper limit is needed. A deep media layer provides additional filtration and supports plants with deeper roots. Standard specifications shall be followed. For non-standard or proprietary designs, compliance with F.1 ensures that adequate treatment performance will be provided. February 2016 ------------------------------ ------- - Siting and Design Appendix E: BMP Design Fact Sheets Intent/Rationale --·----------------·----------------------~------------·---------------~----------- □ □ Media surface area is 3% of contributing area times adjusted runoff factor or greater. Where receiving waters are impaired or have a TMDL for nutrients, the system is designed with nutrient sensitive media design (see fact sheet BF-2). Filter Course Layer □ □ □ A filter course is used to prevent migration of fines through layers of the facility. Filter fabric is not used. Filter course is washed and free of fines. Filter course calculations assessing suitability for particle migration prevention have been completed. Greater surface area to tributary area ratios: a) maximizes volume retention as required by the MS4 Permit and b) decrease loading rates per square foot and therefore increase longevity. Adjusted runoff factor is to account for site design BMPs implemented upstream of the BMP (such as rain barrels, impervious area dispersion, etc.). Refer to Appendix B.2 guidance. Use Worksheet B.5-1 Line 26 to estimate the minimum surface area required per this criteria. ----- Potential for pollutant export is partly a function of media composition; media design must minimize potential for export of nutrients, particularly where receiving waters are impaired for nutrients. ---- Migration of media can cause clogging of the aggregate storage layer void spaces or subgrade. Filter fabric is more likely to clog. --- Washing aggregate will help eliminate fines that could clog the facility and impede infiltration. Gradation relationship between layers can evaluate factors (e.g., bridging, permeability, and uniformity) to determine if particle sizing is appropriate or if an intermediate layer is needed. Aggregate Storage Layer -------· -------- □ Class 2 Permeable per Caltrans specification Washing aggregate will help eliminate 68-1.025 is recommended for the storage layer. fines that could clog the aggregate Washed, open-graded crushed rock may be storage layer void spaces or subgrade. used, however a 4-6 inch washed pea gr~vel ___ ____ ___ _ _____________________________ _ E-71 February 2016 ----------- ------------- ------- - -- --------·· - Siting and Design □ filter course layer at the top of the crushed rock is required. The depth of aggregate provided (12-inch typical) and storage layer configuration is adequate for providing conveyance for underdrain flows to the outlet structure. In.iow, Underdrain, and Out.iow Structures □ □ □ □ □ □ Inflow, underdrains and outflow structures are accessible for inspection and maintenance. Inflow velocities are limited to 3 ft/ s or less or use energy dissipation methods. ( e.g., riprap, level spreader) for concentrated inflows. Curb cut inlets are at least 12 inches wide, have a 4-6 inch reveal (drop) and an apron and energy dissipation as needed. U nderdrain outlet elevation should be a minimum of 3 inches above the bottom elevation of the aggregate storage layer. Minimum underdrain diameter is 6 inches. Underdrains are made of slotted, PVC pipe conforming to ASTM D 3034 or equivalent or corrugated, HDPE pipe conforming to AASHTO 252M or equivalent. Appendix E: BMP Design Fact Sheets Intent/Rationale Proper storage layer configuration and underdrain placement will minimize facility drawdown time. Maintenance will prevent clogging and ensure proper operation of the flow control structures. High inflow velocities can cause erosion, scour and/ or channeling. --·-------·-------- Inlets must not restrict flow and apron prevents blockage from vegetation as it grows in. Energy dissipation prevents erosion. ------------------------ A minimal separation from subgrade or the liner lessens the risk of fines entering the underdrain and can improve hydraulic performance by allowing perforations to remain unblocked. Smaller diameter underdrains are prone to clogging. ------.. --------- Slotted underdrains provide greater intake capacity, clog resistant drainage, and reduced entrance velocity into the pipe, thereby reducing the chances of solids migration. ----------------·----------------· --------··------·-----------------------------------------------------------------~---- An underdrain cleanout with a minimum 6- □ inch diameter and lockable cap is placed every Properly spaced cleanouts will facilitate 250 to 300 feet ¥ required based on underdrain length. ---------------------- Overflow is safely conveyed to a downstream D storm drain system or discharge point Size overflow structure to pas~ 10_0_-rea~peak ~()W E-72 underdrain maintenance. Planning for overflow lessens the risk of property damage due to flooding. February 2016 ---- --- ----------------------------- -- Siting and Design for on-line infiltration basins and water quality peak flow for off-line basins. Appendix E: BMP Design Fact Sheets Intent/Rationale Conceptual Design and Sizing Approach for Storm Water Pollutant Control Only To design bioretention with underdrain for storm water pollutant control only (no flow control required), the following steps should be taken: 1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slopes, and the recommended media surface area tributary ratio. 2. Calculate the DCV per Appendix B based on expected site design runoff for tributary areas. 3. Use the sizing worksheet presented in Appendix B.5 to size biofiltration BMPs. Conceptual Design and Sizing Approach when Storm Water Flow Control Is Applicable Control of flow rates and/ or durations will typically require significant surface ponding and/ or aggregate storage volumes, and therefore the following steps should be taken prior to determination of storm water pollutant control design. Pre-development and allowable post-project flow rates and durations should be determined as discussed in Chapter 6 of the manual. 1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slopes, and the recommended media surface area tributary ratio. 2. Iteratively determine the facility footprint area, surface ponding _and/ or aggregate storage layer depth required to provide detention storage to reduce flow rates and durations to allowable limits. Flow rates and durations can be controlled from detention storage by altering outlet structure orifice size(s) and/ or water control levels. Multi-level orifices can be used within an outlet structure to control the full range of flows. 3. If bioretention with underdrain cannot fully provide the flow rate and duration control required by this manual, an upstream or downstream structure with significant storage volume such as an underground vault can be used to provide remaining controls. 4. After bioretention with underdrain has been designed to meet flow control requirements, calculations must be completed to verify if storm water pollutant control requirements to treat the DCV have been met. E-73 February 2016 --------- -------------.. -------------- Appendix E: BMP Design Fact Sheets E.13 BF-2 Nutrient Sensitive Media Design Some studies of bioretention with underdrains have observed export of nutrients, particularly inorganic nitrogen (nitrate and nitrite) and dissolved phosphorus. This has been observed to be a short-lived phenomenon in some studies or a long term issue in some studies. The composition of the soil media, including the chemistry of individual elements is believed to be an important factor in the potential for nutrient export. Organic amendments, often compost, have been identified as the most likely source of nutrient export. The quality and stability of organic amendments can vary widely. The biofiltration media specifications contained in the County of San Diego Low Impact Development Handbook: Appendix G -Bioretention Soil Specification 0une 2014, unless superseded by more recent edition) and the City of San Diego Low Impact Development Design Manual (page B-18) 0uly 2011, unless superseded by more recent edition) were developed with consideration of the potential for nutrient export. These specifications include criteria for individual component characteristics and quality in order to control the overall quality of the blended mixes. As of the publication of this manual, the June 2014 County of San Diego specifications provide more detail regarding mix design and quality control. The City and County specifications noted above were developed for general purposes to meet permeability and treatment goals. In cases where the BMP discharges to receiving waters with nutrient impairments or nutrient TMDLs, the biofiltration media should be designed with the specific goal of minimizing the potential for export of nutrients from the media. Therefore, in addition to adhering to the City or County media specifications, the following guidelines should be followed: 1. Select plant palette to minimize plant nutrient needs A landscape architect or agronomist should be consulted to select a plant palette that minimizes nutrient needs. Utilizing plants with low nutrient needs results in less need to enrich the biofiltration . soil mix. If nutrient quantity is then tailored to plants with lower nutrient needs, these. plants will generally have less competition from weeds, which typically need higher nutrient content. The following practices are recommended to minimize nutrient needs of the plant palette: • Utilize native, drought-tolerant plants and grasses where possible. Native plants generally have a broader tolerance for nutrient content, and can be longer lived in leaner/lower nutrient soils. • Start plants from smaller starts or seed. Younger plants are generally more tolerant of lower nutrient levels and tend to help develop soil structure as they grow. Given the lower cost of smaller plants, the project should be able to accept a plant mortality rate that is somewhat higher than starting from larger plants and providing high organic content. 2. Minimize excess nutrients in media mix Once the low-nutrient plant palette is established (item 1), the landscape architect and/or agronomist should be consulted to assist in the design of a biofiltration media to balance the interests of plant E-74 February 2016 --------- ----------------------- ---- Appendix E: BMP Design Fact Sheets establishment, water retention capacity (irrigation demand), and the potential for nutrient export. The following guidelines should be followed: • The mix should not exceed the nutrient needs of plants. In conventional landscape design, the nutrient needs of plants are often exceeded intentionally in order to provide a factor of safety for plant survival. This practice must be avoided in biofiltration media as excess nutrients will increase the chance of export. The mix designer should keep in mind that nutrients can be added later (through mulching, tilling of amendments into the surface), but it is not possible to remove nutrients, once added. • The actual nutrient content and organic content of the selected organic amendment source should be determined when specifying mix proportions. Nutrient content (i.e., C:N ratio; plant extractable nutrients) and organic content (i.e, % organic material) are relatively inexpensive to measure via standard agronomic methods and can provide important information about mix design. If mix design relies on approximate assumption about nutrient/ organic content and this is not confirmed with testing ( or the results of prior representative testing), it is possible that the mix could contain much more nutrient than intended. • Nutrients are better retained in soils with higher cation exchange capacity. Cation exchange capacity can be increased through selection of organic material with naturally high cation exchange capacity, such as peat or coconut coir pith, and/ or selection of inorganic material with high cation exchange capacity such as some sands or engineered minerals (e.g., low P-index sands, zeolites, rhyolites, etc). Including higher cation exchange capacity materials would tend to reduce the net export of nutrients. Natural silty materials also provide cation exchange capacity; however potential impacts to permeability need to be considered. • Focus on soil structure as well as nutrient content. Soil structure is loosely defined as the ability of the soil to conduct and store water and nutrients as well as the degree of aeration of the soil. Soil structure can be more important than nutrient content in plant survival and biologic health of the system. If a good soil structure can be created with very low amounts of organic amendment, plants survivability should still be provided. While soil structure generally develops with time, biofiltration media can be designed to promote earlier development of soil structure. Soil structure is enhanced by the use of amendments with high humus content (as found in well-aged organic material). In addition, soil structure can be enhanced through the use of organic material with a distribution of particle sizes (i.e., a more heterogeneous mix). • Consider alternatives to compost. Compost, by nature, is a material that is continually evolving and decaying. It can be challenging to determine whether tests previously done on a given compost stock are still representative. It can also be challenging to determine how the properties of the compost will change once placed in the media bed. More stable materials such as aged coco coir pith, peat, biochar, shredded bark, and/ or other amendments should be considered. With these considerations, it is anticipated that less than 10 percent organic amendment by volume E-75 February 2016 ----------------------------------- -- Appendix E: BMP Design Fact Sheets could be used, while still balancing plant survivability and water retention. If compost is used, designers should strongly consider utilizing less than 10 percent by volume. 3. Design with partial retention and/ or internal water storage An internal water storage zone, as described in Fact Sheet PR-1 is believed to improve retention of nutrients. For lined systems, an internal water storage zone worked by providing a zone that fluctuates between aerobic and anaerobic conditions, resulting in nitrification/ denitrification. In soils that will allow infiltration, a partial retention design (PR-1) allows significant volume reduction and can also promote nitrification/ denitrification. Acknowledgment: This fact sheet has been adapted from the Orange County Technical Guidance Document (May 2011). It was originally developed based on input from: Deborah Deets, City of Los Angeles Bureau of Sanitation, Drew Ready, Center for Watershed Health, Rick Fisher, ASLA, City of Los Angeles Bureau of Engineering, Dr. Garn Wallace, Wallace Laboratories, Glen Dake, GD:ML, and Jason Schmidt, Tree People. The guidance provided herein does not reflect the individual opinions of any individual listed above and should not be cited or otherwise attributed to those listed. E-76 February 2016 ----------- ---------------------- --- Appendix E: BMP Design Fact Sheets E.14 BF-3 Proprietary Biofiltration Systems The purpose of this fact sheet is to help explain the potential role of proprietary BMPs in meeting biofiltration requirements, when full retention of the DCV is not feasible. The fact sheet does not describe design criteria like the other fact sheets in this appendix because this information varies by BMP product model. Criteria for Use of a Proprietary BMP as a Bloffltratlon BMP A proprietary BMP may be acceptable as a "biofiltration BMP" under the following conditions: (1) The BMP meets the minimum design criteria listed in Appendix F, including the pollutant treatment performance standard in Appendix F.1; (2) The BMP is designed and maintained in a manner consistent with its performance certifications (See explanation in Appendix F.2); and (3) The BMP is acceptable at the discretion of the City Engineer. In determining the acceptability of a BMP, the City Engineer should consider, as applicable, (a) the data submitted; (b) representativeness of the data submitted; (c) consistency of the BMP performance claims with pollutant control objectives; certainty of the BMP performance claims; ( d) for projects within the public right of way and/ or public projects: maintenance requirements, cost of maintenance activities, relevant previous city experience with operation and maintenance of the BMP type, ability to continue to operate the system in event that the vending company is no longer operating as a business; and (e) other relevant factors. Guidance for Sizing a Proprietary BMP as a Bloffltratlon BMP Proprietary biofiltration BMPs must meet the same sizing guidance as non-proprietary BMPs. Sizing is typically based on capturing and treating 1.50 times the DCV not reliably retained. Guidance for sizing biofiltration BMPs to comply with requirements of this manual is provided in Appendix F.2. E-77 February 2016 MAINTENANCE MWS-Linear Hybrid Stormwater Filtration System M 0 D U L A R ET Modular Wetland Systems, Inc. P.O. Box 869 www.modularwetlands.com P 760-433-7640 F 760-433-3179 Oceanside, CA 92049 MAINTENANCE Maintenance Summary - o Clean Bio Clean® Catch Basin Filter -average maintenance interval is 3 to 6 months. • ( 15 minute service time). o Clean Separation (sediment) Chamber -average maintenance interval is 6 to 18 months. • (30 minute service time). o Replace Cartridge Filter Media (BioMediaGREEN™) -average maintenance interval 6 -12 months. • (45 minute service time). o Replace Drain Down Filter Media (BioMediaGREEN™) -average maintenance interval is 6 to 12 months. • (5 minute service time). o Trim Vegetations -average maintenance interval is 3 to 6 months. • (15 minute service time). o Evaluate Wetland Media Flow Hydraulic Conductivity -average inspection interval is once per year. • (5 minute inspection time). o Wetland Media Replacement -average maintenance interval is 5 to 20 years. • (6 hours). For more information on maintenance procedures, to order replacement media or find an authorized service company please contact: Modular Wetland Systems, Inc 2972 San Luis Rey Road Oceanside, CA 92058 Phone: 760-433-7640 Fax: 760-433-3176 Email: info@modularwetlands.com System Diagram - Access to screening device, sedimenf chamber and cartridge filter Pre-Treatment Chamber Maintenance Overview - Wetland Biofiltration Chamber Access to drain down filter and flow valves Discharge Chamber A. Every installed MWS -Linear unit is to be maintained by the Supplier, or a Supplier approved contractor. The cost of this service varies among providers. B. The MWS -Linear is a multi-stage self-contained treatment train for stormwater treatment. Each stage protects subsequent stages from clogging. Stages include: screening, separation, cartridge media filtration, and biofiltration. The biofiltration stage contains various types of vegetation which will require annual evaluation and trimming. 1. Clean Bio Clean® Catch Basin Filter -Screening is provided by well proven catch basin filter. The filter has a trash and sediment capacity of 2 (curb type) and 4 (grate type) cubic feet. The filter removes gross solids, including litter, and sediments greater than 200 microns. This procedure is easily done by hand or with a small industrial vacuum device. This filter is located directly under the manhole or grate access cover. 2. Clean Separation (sediment) Chamber -separation occurs in the pre- treatment chamber located directly under the curb or grated inlet. This chamber has a capacity of approximately 21 cubic feet for trash, debris and sediments. This chamber targets TSS, and particulate metals and nutrients. This procedure can be performed with a standard vacuum truck. This chamber is located directly under the manhole or grate access cover. 3. Replace Cartridge Filter Media (BioMediaGREEN™) -Primary filtration is provided by a horizontal flow cartridge filter utilizing BioMediaGREEN blocks. Each cartridge has a media surface area of 35 square feet. The large surface area will insure long term operation without clogging. The cartridge filter with BioMediaGREEN targets fine TSS, metals, nutrients, hydrocarbons, turbidity and bacteria. Media life depends on local loading conditions and can easily be replaced and disposed of without any equipment. The filters are located in the pre-treatment chamber. Entry into chamber required to replace BioMediaGREEN blocks. Each cartridge contain 14 pieces of 20" tall BioMediaGREEN. 4. Replace Drain Down Filter Media (BioMediaGREEN™) -A drain down filter, similar in function to the perimeter filter is located in the discharge chamber. This filter allows standing water to be drained and filtered out of the separation chamber. This addresses any vector issues, by eliminating all standing water within this system. Replacement of media takes approximately 5 minutes and is performed without any equipment. 5. Trim Vegetations -The system utilizes multiple plants in the biofiltration chamber to provide enhanced treatment for dissolved pollutants including nutrients and metals. The vegetation will need to be maintained (trimmed) as needed. This can be done as part of the project normal landscape maintenance. NO FERTILIZER SHALL BE USED IN THIS CHAMBER. 6. Evaluate Wetland Media Flow Hydraulic Conductivity -The systems flow can be assessed from the discharge chamber. This should be done during a rain event. By viewing into the discharge chamber the flow out of the system can be observed. If little to know flow is observed from the lower valve or orifice plate this is a sign of potential wetland media (biofiltration) maintenance needs. 7. Wetland Media Replacement -biofiltration is provided by an advance horizontal flow vegetated wetland. This natural filter contains a mix of sorptive media that supports abundant plant life. This biofilter targets the finest TSS, dissolved nutrients, dissolved metals, organics, pesticides, oxygen demanding substances and bacteria. This filter provides the final polishing step of treatment. If prior treatment stages are properly maintained, the life of this media can be up to 20 years. Replacement of the media is simple. Removal of spent media can be done with a shovel of a vacuum truck. C. The MWS -Linear catch basin filter, separation chamber, cartridge filter media and wetland media are designed to allow for the use of vacuum removal of captured pollutants and spent filter media by centrifugal compressor vacuum units without causing damage to the filter or during normal cleaning and maintenance. Filter and chambers can be cleaned from finish surface through standard manhole or grate access. Maintenance Procedures - 1. Clean Bio Clean® Catch Basin Filter -Modular Wetland Systems, Inc. recommends the catch basin filter be inspected and cleaned a minimum of once every six months and replacement of hydrocarbon booms once a year. The procedure is easily done with the use of any standard vacuum truck. This procedure takes approximately 15 minutes. 1 . Remove grate or manhole to gain access to catch basin filter insert. Remove the deflector shield (grate type only) with the hydrocarbon boom attached. Where possible the maintenance should be performed from the ground surface. Note: entry into an underground stormwater vault such as an inlet vault requires certification in confined space training. 2. Remove all trash, debris, organics, and sediments collected by the inlet filter insert. Removal of the trash and debris can be done manually or with the use of a vacuum truck. The hose of the vacuum truck will not damage the screen of the filter. 3. Evaluation of the hydrocarbon boom shall be performed at each cleaning . If the boom is filled with hydrocarbons and oils it should be replaced. Attach new boom to basket with plastic ties through pre-drilled holes in basket. Place the deflector shield (grate type only) back into the filter. 4. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements. 5. The hydrocarbon boom may be classified as hazardous material and will have to be picked up and disposed of as hazardous waste. Hazardous material can only be handled by a certified hazardous waste trained person (minimum 24- hour hazwoper). 2. Clean Separation (sediment) Chamber -Modular Wetland Systems, Inc. recommends the separation chamber be inspected and cleaned a minimum of once a year. The procedure is easily done with the use of any .standard vacuum truck. This procedure takes approximately 30 minutes. 1. Remove grate or manhole to gain access to the catch basin filter. 2. Remove catch basin filter. Where possible the maintenance should be performed from the ground surface. Note: entry into an underground stormwater vault such as an inlet vault requires certification in confined space training. 3. With a pressure washer spray down pollutants accumulated on walls and cartridge filters. 4. Vacuum out separation chamber and remove all accumulated debris and sediments. 5. Replace catch basin filter, replace grate or manhole cover. 6. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements. 3. Replace Cartridge Filter Media (BioMediaGREEN™) -Modular Wetland Systems, Inc. recommends the cartridge filters media be inspected and cleaned a minimum of once a year. The procedure will require prior maintenance of separation chamber. Replacement of media takes approximately 45 minutes. 1. Remove grate or manhole to gain access to the catch basin filter. 2. Remove catch basin filter. Where possible the maintenance should be performed from the ground surface. Note: entry into an underground stormwater vault such as an inlet vault requires certification in confined space training. 3. Enter separation chamber. 4. Unscrew the two ½" diameter bolts holding the lid on each cartridge filter and remove lid and place outside of unit. 5. Remove each of the 14 BioMediaGREEN filter blocks in each cartridge and remove from chamber for disposal. 6. Spray down the outside and inside of the cartridge filter to remove any accumulated sediments. 7. Replace with new BioMediaGREEN filter blocks insuring the blocks are properly lined up and seated in the bottom. 8. Replace the lid and tighten down bolts. 9. Replace catch basin filter, replace grate or manhole cover. 10. Transport all debris, trash, organics, spent media and sediments to approved facility for disposal in accordance with local and state requirements. 4. Replace Drain Down Filter Media (BioMediaGREEN™) -Modular Wetland Systems, Inc. recommends the drain down filter be inspected and maintained a minimum of once a year. Replacement of media takes approximately 5 minutes. 1. Open hatch of discharge chamber 2. Enter chamber, unlatch drain down filter cover. 3. Remove BioMediaGREEN filter block 4. Replace with new block, replace and latch cover. 5. Exit chamber, close and lock down the hatch. 6. Transport spent media to approved facility for disposal in accordance with local and state requirements. 5. Trim Vegetations -Modular Wetland Systems, Inc. recommends the plants/vegetation be inspected and maintained a minimum of once a year. It is also recommended that the plants receive the same care as other landscaped areas. Note: No fertilizer is to be used on this area. Trimming of vegetation takes approximately 15 minutes. 6. Evaluate Wetland Media Flow Hydraulic Conductivity -Modular Wetland Systems, Inc. recommends system flow be inspected and observed a minimum of once a year. This needs to be done during a rain event. Inspection and Observation takes approximately 5 minutes. 1. Open hatch of discharge chamber 2. Observe the level of flow from the bottom valve or orifice plate. 3. If flow is steady and high the system is operating normally. 4. If little or no flow is observed exiting the valve possible maintenance to the biofiltration wetland chamber may be needed. Contact Modular Wetlands for further assistance. 5. Exit chamber, close and lock down the hatch. 7. Wetland Media Replacement -Modular Wetland Systems, Inc. recommends the wetland media be replaced a minimum of one every 20 years. Inspection takes approximately 15 minutes. Replacement of rock media takes approximately 6 hours and requires a vacuum truck. 1. Remove plants from the wetland chamber. 2. Use a vacuum truck or shovel to remove all wetland media. 3. Spray down the walls and floor of the chamber and vacuum out any accumulated pollutants. 4. Spray down perforated piping and netting of flow matrix and the inflow and outflow end to remove any accumulated pollutants. 5. Vacuum out any standing water from the media removal and insure the chamber is cleaning. 6. Use a small backhoe to fill chamber with new media. Call Modular Wetland Systems, Inc. for media delivery information. 7. Install BioMediaGREEN filter blocks across over the entire filter bed. Fill with media until 9" from top. The install filter blocks which are 3" thick. Fill the top 6" inches with wetland media. 8. Plant new vegetation in the same configuration and quantity as old vegetation. Dig down until the BioMediaGREEN is exposed. Cut out a small circle of the BioMediaGREEN. Remove plant from container including soil ball and place in the whole cut out of the BioMediaGREEN. Cover up with wetland media. 9. Spray down the plants and media with water to saturate. 10. Continue supplemental irrigation (spray or drip) for at lest 90 days. 7. Other Maintenance Notes - 1 .. Following maintenance and/or inspection, the maintenance operator shall prepare a maintenance/inspection record. The record shall include any maintenance activities performed, amount and description of debris collected, and condition of the system and its various filter mechanism .. 2. The owner shall retain the maintenance/inspection record for a minimum of five years from the date of maintenance. These records shall be made available to the governing municipality for inspection upon request at any time. 3. Any person performing maintenance activities must have completed a minimum of OSHA 24-hour hazardous waste worker (hazwoper) training. 4. Remove access manhole lid or grate to gain access to filter screens and sediment chambers. Where possible the maintenance should be performed from the ground surface. Note: entry into an underground stormwater vault such as an inlet vault requires certification in confined space training. 5. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements. 6. The hydrocarbon boom is classified as hazardous material and will have to be picked up and disposed of as hazardous waste. Hazardous material can only be handled by a certified hazardous waste trained person (minimum 24-hour hazwoper). Maintenance Sequence - Access Pre-Treatment Chamber by Removing Manhole or Grate Cover Vacuum Catch Basi11 Filter Vacuum out the Sediment Chamber Assess Pollutant Loading in Catch Basin Filter and Sedimenl Chamber Remove Catch Basin Filter Enter Chamber Remove Lids of Cartridge Filters Remove Spent BioMediaGREEN Filter Blocks Replace with New BioMediaGREEN Filter Blocks and Replace Lid, then Catch Basin Filter and Replace Manhole or Grate Evaluate Vegetation and Trim if Needed. Maintenance Complete. Spray Down and Clean Cartridge Filter Housing Open Discharge Chamber Lid to Asses Wetland Media Flow Rate and Replace Drain Down Filter Near Bottom Please Contact Modular Wetland Systems, Inc. for More Information: 760-433-7640 info@modularwetlands.com r; ~ '111 TREATMENT CONTROL BMP VERIFICATION FORM Pursuant to CMC 15.12.100 L OwnerName GENERAL INFORMATION Owner Address City and Zip • Contact Name Contact Phone New Contact New Phone BMP INFORMATION r BMPType BMPIO# I Prlorltv I BMP Description Manufacturer BMP Location BMP Address BMP Approval Date I Last Inspection Date Maintenance Freauencv I 1 Comments ·1 I BMP VERIFICATION AND MAINTENANCE ~ V) 0 !:-3: ~ w zo >-z oz z c~ BMP ACTIVITY COMMENTS r' Has the BMP been installed? Has the BMP been removed? J Is the BMP operatino properly? I Has the BMP been replaced? If so when? r I Is BMP covered under a maintenance aoreement? Is the BMP on a regular maintenance schedule? 1' Has trash or other debris accumulated in or around BMP? I Has the BMP been inspected during the last year? l Has the BMP been maintained or cleaned durina the last vear? Are discharae points free of litter and debris? I Has it rained since the last time the BMP was maintained? I D Leaking Vehicles D Erosion/Sediments D Trash and Debris ( What are the sources of pollution that could impact the BMP? D Over Irrigation D Improvement Projects (paint, concrete wash, landscaping, etc.) D PeUAnimal Waste D Lawn clippings and yard waste ·1 D Other Certification Statement "I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in J accordance with a system to assure that the responsible party gathered and evaluated the information submitted. Based on my inquiry of the person or person who managed the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief true, accurate and complete, I am aware that there are significant penalties for submittina false information includina the oossibilitv of fines and other enforcement actions." PRINT NAME: SIGNATURE Please return the completed and signed form to the City of Carlsbad CMI -Storm Water Compliance 5950 El Camino Real Carlsbad, CA 92008 760-602-2780 or FAX 760-438-7178 DATE Attachment 4 City Standard Single Sheet BMP Exhibit I I EXISTING BUILDING B FF-762 s ------------El s 0 --) El I I I I I I I I I I !~ El 0 (/) /, / ,/ ":, ,_ \ I ,~ \ \.'.) / v / 20· 1 o· o 20· 40• '----'I ~f----1 _ __JI SCALE: 1 • = 20' EXISTING BUILD/NGA FF-75.2 i ;1 PLAN VIEW SCALE: 1" = 20' PASCO LARET SUITER & ASSOCIATES CIVIL ENGINEERING + LAND PLANNING + LAND SURVEYING 535 Horth Blpway 101, Ste A, Solana Beach, CA 112075 ph 858,2511,8212 I & 858.2511."812 I pla1enB1n-r1ng.com I I I I I /( I I I I I ,11 'I . I DATE 1Nll1AL ENGINEER OF WORK b BMPID# BMPTYPE SDP(M INOR) 2019-0003 / CDP 2019 -0005 / SP(AMEND ) 2019-0002 PARTY RESPONSIBLE FOR MAINTENAN CE: NEXThlED Ill OWNER, LLC 6183-6185 PASEO DEL NORTE CARLSBAD, CA 92011 (760) 602-7872 CONTACT: SCOTT LEGGETT PLAN PREPARED BY: PASCO LARET SUITER & ASSOCIATES 535 N. HWY 101 , SUITE A SOLANA BEACH, CA 92075 (858)-259-8212 BMP NOTES: SIGNAi URE 1. THESE BMPS ARE MANDATORY TO BE INSTALLED PER MANUFACTURER'S RECOMMENDATIONS OR THESE PLANS. 2. NO CHANGES TO THE PROPOSED BMPS ON THIS SHEET WITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER. 3. NO SUBSTITUTIONS TO THE MATERIAL OR TYPES OR PLANTING TYPES WITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER. 4. NO OCCUPANCY WILL BE GRANTED UNTIL THE CITY INSPECTION STAFF HAS INSPECTED THIS PROJECT FOR APPROPRIATE BMP CONSTRUCTION AND IN STALLATION. 5. REFER TO MAINTENANCE AGREEMENT DOCUMENT. 6. SEE PROJECT SWQMP FOR ADDITIONAL INFORMATION. BMP TABLE ',ff"< IV. ~ . RCE 68075 . 06-30-2 SYMBOL CASQA NO. QUANTITY DRAWING NO. SHEET NO.(S) INSPECTION FREQUENCY MAINTENANCE FREQUENCY TREATMENT CONTROL (PROJECT IS EXEMPT FROM HYDROMODIFICAITON REQUIREMENTS) (j)&(D BIOFIL TRA TION (I ..... · l) TC-32 2,229 SF. 5 QUARTERLY BASIN (BF-1) SEMI-ANNUALLY @ BIOFILTRATION [[] (1) x MWS-L-4-4 (BF-3) 5 QUARTERLY SEMI-ANNUALLY SOURCE CONTROL ©-® STENCILS NO DUMPING SD-13 DRAINS TO OCEAN ----ANNUALLY AS-NEEDED @ SITE DESIGN ~ AND LANDSCAPE SD-10 11,051 SF. 5 QUARTERLY SEMI-ANNUALLY PLANNING I SH,ET I CITY OF CARLSBAD I SH,ETS I ENGINEERING DEPARTMENT SINGLE SHEET BMP SITE PLAN CARLSBAD CORPORA 7E PLAZA PARKJNG STRUCTURE RECORD COPY I CCP209-0005 I DATE 1Nll1AL DATE INITIAL I DRA~NG NO. I REVISION DESCRIPTION OTHER APPROVAL CITY APPROVAL INITIAL DATE