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Home My WebLink AboutCUP 2022-0010; CARLSBAD DESALINATION PLANT INTAKE AND DISCHARGE MODIFICATION; PRIORITY DEVELOPMENT PROJECT STORM WATER QUALITY MANAGEMENT PLAN FOR POSEIDON CHANNELSIDE CARLSBAD DESALINATION PLANT; 2023-12-08STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) E-35 (FOR PDP PROJECTS ONLY) PREPARED FOR: KIEWIT INFRASTRUCTURE GROUP 10704 SHOEMAKER AVENUE SANTA FE SPRINGS, CA 90670 (562) 321-3027 JIMMY HUYNH PREPARED BY: HDR INC. 2280 MARKET STREET, SUITE 100 RIVERSIDE, CA 92501-2110 (951) 320-7311 BILL FLORES, PE, QSD DATE: DECEMBER 08, 2023 CITY OF CARLSBAD PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) FOR POSEIDON CHANNELSIDE CARLSBAD DESALINATION PLANT PHASE 2 – INTAKE MODIFICATION PROJECT ID: CUP 2022-0010 100% DWG 539-8A GR No. 2022-0047 ENGINEER OF WORK: GUILLERMO FLORES JR PE NUMBER 45181 Development Services Land Development Engineering 1635 Faraday Avenue 442-339-2750 www.carlsbadca.gov December 08, 2023| i Contents Certification Page ....................................................................................................................... 1 Project Vicinity Map ................................................................................................................... 2 Form E-34 Storm Water Standard Questionnaire ....................................................................... 3 Site Information Checklist .......................................................................................................... 4 Form E-36 City’s Standard Project Requirement Checklist .......................................................14 Summary of PDP Structural BMPs ............................................................................................15 Attachments Attachment 1: Backup for PDP Pollutant Control BMPs Attachment 1a: DMA Exhibit Attachment 1b: Tabular Summary of DMAs and Design Capture Volume Calculations Attachment 1c: Harvest and Use Feasibility Screening (when applicable) Attachment 1d: Infiltration Feasibility Analysis (when applicable) Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations Attachment 1f: Trash Capture BMP Requirements Attachment 2: Backup for PDP Hydromodification Control Measures Attachment 2a: Hydromodification Management Exhibit Attachment 2b: Management of Critical Coarse Sediment Yield Areas Attachment 2c: Geomorphic Assessment of Receiving Channels Attachment 2d: Flow Control Facility Design Attachment 3: Structural BMP Maintenance Thresholds and Actions Attachment 4: Single Sheet BMP (SSBMP) Exhibit Attachment 5: Pre-Phase 1 and Phase 1 Information December 08, 2023| 1 Certification Page Project Name: Poseidon Channelside Carlsbad Desalination Plant Phase 2 – Intake Modification Project ID: CUP 2022-0010 I hereby declare that I am the Engineer in Responsible Charge of design of storm water best management practices (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 San Diego Regional Water Quality Control Board (RWQCB) 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 Storm Water Quality Management Plan (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. 45181, 09/30/2024 Engineer of Work’s Signature, PE Number & Expiration Date Guillermo Flores Jr Print Name HDR Company December 07, 2023 Date December 08, 2023 | 2 Project Vicinity Map December 08, 2023 | 3 Form E-34 Storm Water Standard Questionnaire STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 442-339-2750 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, “PRIORITY DEVELOPMENT PROJECT (PDP) requirements or not considered a development project. This questionnaire will also determine if the project is subject to TRASH CAPTURE 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: APN: ADDRESS: The project is (check one): New Development Redevelopment The total proposed disturbed area is: ft2 ( ) acres The total proposed newly created and/or replaced impervious area is: ft2 ( ) 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. This Box for City Use Only City Concurrence: YES NO Date: Project ID: By: E-34 Page 1 of 4 REV 08/22 INSTRUCTIONS: 210-010-49 143,560 38,766 0.89 Carlsbad Desalination Plant Intake Screening - Phase 2 210-010-454600 Carlsbad Blvd, Carlsbad, CA 92008 73,456 1.69 29,735 0.68 E-34 Page 2 of 4 REV 08/22 STEP 1 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 6, mark the 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. STEP 2 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; OR b) Designed and constructed to be hydraulically disconnected from paved streets or roads; OR 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 accordance with the USEPA Green Streets guidance? 3. Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual? If you answered “yes” to one or more of the above questions, provide discussion/justification below, then go to Step 6, mark the second box stating “my project is EXEMPT from PDP …” and complete applicant information. Discussion to justify exemption (e.g. the project redeveloping existing road designed and constructed in accordance with the USEPA Green Street guidance): If you answered “no” to the above questions, your project is not exempt from PDP, go to Step 3. E-34 Page 3 of 4 REV 08/22 STEP 3 TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1)): YES NO 1. Is your project a new development that creates 10,000 square feet or more of impervious surfaces collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, and public development projects on public or private 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 development projects on public or private 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 development project includes development on any natural slope that is twenty-five percent or greater. 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 transportation of automobiles, trucks, motorcycles, and other vehicles. 7. Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more of impervious surface collectively over the entire site, and discharges directly to an Environmentally Sensitive Area (ESA)? “Discharging Directly to” includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).* 8. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface that supports an automotive repair shop? An automotive repair 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 per day. 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) 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, complete the trash capture question. If you answered “no” to all of the above questions, your project is a ‘STANDARD PROJECT’. Go to step 5, complete the trash capture question. * Environmentally Sensitive 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. December 08, 2023 | 4 Site Information Checklist Project Summary Information Project Name Poseidon Channelside Carlsbad Desalination Plant Phase 2 - Intake Modification Project ID CUP 2022-0010 / GR 2022-0047 Project Address 4590 Carlsbad Boulevard, Carlsbad, California 92008 Assessor’s Parcel Number(s) (APN[s]) 210-010-45, 210-010-49 Project Watershed (Hydrologic Unit) Carlsbad HU (904.00), Agua Hedionda HA (904.30), Los Monos HSA (904.31) Parcel Area 63 acres (2,744,280 square feet) Existing Impervious Area (subset of Parcel Area) 3.41 acres (148,697 square feet) [project area] 39 acres (1,698,840 square feet) [parcel area] Area to be disturbed by the project (Project Area) 1.69 acre (73,456 square feet) Project Proposed Impervious Area (subset of Project Area) 0.68 acre (29,735 square feet) [new and reconstructed pavement areas] Project Proposed Pervious Area (subset of Project Area) 1.01 acre (43,721 square feet) [forebay gravel area, new & reconstructed landscaped areas, removed impervious surface] Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the Project. This area includes, but is not limited to, off-site work including public improvements and temporary disturbance such as vehicle and equipment staging areas, construction worker foot traffic, soil/gravel piles, utility trenches, backfill cuts, and slope keyways. December 08, 2023 | 5 Description of Existing Site Condition and Drainage Patterns Current Status of the Site (select all that apply): Existing development □ Previously graded but not built out □ Agricultural or other non-impervious use □ Vacant, undeveloped/natural Description / Additional Information: The Claude “Bud” Lewis Carlsbad Desalination Plant (CDP) has been in operation since 2016 to meet local potable water demands. Phase 1 of the plant improvement was recently completed. The plant consists of several features. The dilution pump station, screen structure, and intake structure are adjacent to the Agua Hedionda Lagoon. The brine line outlets to the discharge pond, located between the lagoon and Carlsbad Boulevard, which ultimately outlets to the Pacific Ocean. The lagoon outlets to the Pacific Ocean via its own culvert along Carlsbad Boulevard (about 2,800 feet north of the discharge pond culvert). The lagoon and discharge pond are both lined with riprap. There is a small electrical building that powers the plant and is excavated within a 2:1 slope. Farther south of these features is landscaping that surrounds the CDP-IPS feature and adjacent parking lot. There is also an additional parking lot and an administration building south of the main entrance access road. The main driveway entrance from Carlsbad Boulevard includes a security gate. Currently, there is an aqua farm located north of the discharge pond that is accessible to the public only via the project site. The public uses the site parking areas during business hours, then they walk along a sidewalk and paved access road between the lagoon and discharge pond to reach the aqua farm. The plant is currently undergoing decommissioning of the cohabitated Encina power plant, which operated a shared ocean water intake structure until the end of 2019. This is reflected by the current soil disturbance activity south of the project site. Existing Land Cover Includes (select all that apply): Vegetative Cover □ Non-Vegetated Pervious Areas Impervious Areas Description / Additional Information: South of the access road from the main entrance, most of the site is impervious surface (parking area, administration building, and forebay structure), and the west strip, adjacent to Carlsbad Boulevard, is a landscaped earthen swale. North of the main entrance, most of the site is impervious surface (intake plant, parking areas, miscellaneous small buildings, access roads, etc.), and the remaining is landscaping. Underlying Soil belongs to Hydrologic Soil Group (select all that apply): □ NRCS Type A NRCS Type B □ NRCS Type C □ NRCS Type D Approximate Depth to Groundwater (GW): GW Depth < 5 feet □ 5 feet < GW Depth < 10 feet □ 10 feet < GW Depth < 20 feet □ GW Depth > 20 feet December 08, 2023 | 6 Existing Natural Hydrologic Features (select all that apply): □ Watercourses □ Seeps □ Springs □ Wetlands None Description / Additional Information: The project is adjacent to Agua Hedionda Lagoon and the discharge pond to the north. Both water bodies connect to their own culvert, across Carlsbad Boulevard, which outlets to the Pacific Ocean. Description of Existing Site Topography and Drainage: This project is just one part of the overall parcel for the plant. Most of the project site is relatively flat with slopes ranging from 2 to 5 percent. Most of the site generally surface-flows downhill from south to north toward Agua Hedionda Lagoon and the discharge pond, and the remaining flows are conveyed via pipes. The area east of the project site (to be used for construction laydown yard and temporary parking) drains into the 96-inch reinforced concrete pipe (RCP), which outlets to Agua Hedionda Lagoon. It is assumed that there is no off-site runoff conveyed through the site. The parking area to the south drains to various drain inlets, which outlet to an existing manhole structure that is connected to one of three reinforced concrete boxes that outlet toward the lagoon. The western side of the site (south of the main entrance) drains toward an earthen swale, which drains north through an 18-inch culvert at the main entrance driveway. This culvert continues northward along an 18-inch pipe (assumed) until it outlets to the surface (covered by ice plant) about 100 feet before the discharge pond. From there, it eventually surface-drains to the discharge pond. Above the existing pipe is a minor ditch that drains to the discharge pond. The ditch is barely discernable, as it is covered with iceplant and sediment. Additionally, there is an existing small culvert that drains the access road between the east side of the lagoon and the elevated parking area. Refer to the Project 100% Final Drainage Report (April 28, 2023) for additional information. The Carlsbad Desalination Plant was constructed during Pre-Phase 1 (2009–2010), which overlapped a portion of the proposed Phase 2 project around the existing intake pump station area (landscaping). This feature was part of the Storm Water Management Plan (SWMP 12-22), RP 05-12A, dated August 18, 2015 (prepared for Kiewit Shea Desalination by Arcadis). See Attachment 5 for more information. The area north and west of the parking area adjacent to the existing CDP-IPS facility is landscaped. This landscaped area between the parking area but before the top of slope includes a bioretention basin (approximately 25 feet long by 8 feet wide by 18 inches deep) with a grated catch basin that acts as an emergency overflow structure. This basin was constructed as part of the Poseidon Channelside CDP Intake Pump Station Phase 1 (drawing C-2101). According to the SWQMP for Phase 1, this basin was designed as a site design feature and was not numerically sized. See Attachment 5 for more information. December 08, 2023 | 7 Description of Proposed Site Development and Drainage Patterns Project Description / Proposed Land Use and/or Activities: As a continuation of Phase 1, the modification of the intake and discharge design of Phase 2 requires compliance with the State Water Resources Control Board’s (SWRCB’s) Ocean Plan Amendment (OPA) adopted by the SWRCB in May 2015. The second phase replaces the current screens with OPA-compliant screens along with other ancillary facilities in accordance with a chosen alternative currently under consideration by the RWQCB. Major project components include screen structures, bridge structure and access ramps, screen spraywash system, large organism exclusion devices, debris boom, electrical building, forebay demolition, and relocation of the IPS intake pipeline. Minor components include a new storm drain, site grading, reconstruction of the small parking area, and landscaping. The project will continue maintaining public access to the aqua farm during business hours, including use of the parking areas. The land use will remain the same. According to the Carlsbad General Plan, approved September 22, 2015, Section 2 Land Use and Community Design, the land use of the site is identified as VC/OS, Visitor Commercial/Open Space. The site is also located in the Carlsbad Coastal Zone. The required work in the lagoon, including dredging activities during the construction phase, will be performed in compliance with the applicable USACE Section 404 permit. That work and the project area overlapped by the lagoon is not considered part of this Form E-35 document. List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features): The project will add the following new impervious surfaces (where current surfaces are pervious): Widened access road pavement to the small parking area (north of main entrance), widening of the north portion of the small parking area; a new electrical building including a surrounding pad; widened access road pavement around a new east ramp; and a proposed debris bin area. The project will reconstruct the following impervious surfaces: The trench pavement along the proposed storm drain; reconstruction of the small parking area pavement adjacent to the existing CDP-IPS; replacement of the impacted small parking area pavement with metal covers of the east and west IPS connection vault and bulkhead vault; replacement of pavement with a spray wash pump station (next to intake structure); replacement of access road pavement between the discharge pond and lagoon; replacement of a small downhill portion of the west ramp pavement; and construction of the east ramp pavement and the most easterly section of the concrete access bridge. Due to the demolition of the forebay concrete pavement and its conversion from an impervious surface to a gravel surface, its new pervious surface will be considered as a credit against new and reconstructed impervious surface areas. List/describe proposed pervious features of the project (e.g., landscape areas): The project proposes the following new semi-pervious surfaces: the gravel layer at the forebay demolition area. The project also proposes the following pervious surfaces: the new landscaping area along the south side of the reconstructed small parking lot, and reconstructed landscaping north of the main entrance between the existing sidewalk and Carlsbad Boulevard right-of-way. The project proposes to reconstruct the landscaping between the small parking lot and the site’s main entrance road. Does the project include grading and changes to site topography? Yes □ No Description / Additional Information: There are five main areas that will be graded: (1) the area by the proposed west ramp to the access bridge; (2) the area by the proposed east ramp to the access bridge; (3) the pad for the new electrical building; (4) the curved access road fronting the proposed east ramp (next to the elevated parking area); and (5) the reconstructed small parking area and surrounding landscape. Areas 1 through 4 will require the most excavation and embankment and cause the most changes to site topography. Proposed grading will maintain existing drainage patterns. December 08, 2023 | 8 Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)? Yes □ No Description / Additional Information: The project proposes a 24-inch RCP storm drain extension from the existing manhole (in DMA 1) to the existing brine discharge line. This improvement is mostly within easements C and T. Also, the existing low point between the east ramp and the intake structure, just south of the lagoon, will be removed. The surface runoff from this area will drain to the discharge pond instead of draining to the lagoon. Due to sensitive environmental permitting requirements for the lagoon, the project will not propose new storm drain connections to the lagoon. The project will maintain existing surface drainage patterns where applicable. The existing bioretention basin overflow pipe (2-inch diameter) will be redesigned around the new electrical pad and will outlet to the proposed curb face fronting the electrical pad. 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 December 08, 2023 | 9 Identification of Receiving Water Pollutants of Concern Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake, or reservoir, as applicable): Most of the site generally surface-flows (the rest flows via pipes) downhill from south to north toward the Agua Hedionda Lagoon and the discharge pond. Agua Hedionda Creek, which is conveyed by the existing 96-inch RCP storm drain, is tributary to Agua Hedionda Lagoon. The runoff from the discharge pond drains to the Pacific Ocean via a culvert that crosses Carlsbad Boulevard. The runoff from the Agua Hedionda Lagoon drains to the Pacific Ocean via a culvert that crosses Carlsbad Boulevard, which is located about 2,800 feet north of the first culvert. The area east of the project site (to be used for construction laydown yard and temporary parking) drains into the 96- inch RCP, which outlets to Agua Hedionda Lagoon. See Description of Existing Site Topography and Drainage Section above for more specific project information about on-site drainage conveyance. 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 total maximum daily loads (TMDLs) for the impaired water bodies: The project is in the Agua Hedionda Lagoon watershed. The Lagoon, although not listed on the 2020–2022 303(d) List of Impaired Waterbodies, is the waterbody to which Agua Hedionda Creek is tributary. 303(d) Impaired Water Body (2020–2022) Pollutant(s)/Stressor(s) Pollutant Category TMDLs Agua Hedionda Creek Benthic Community Effects Other Cause TMDL Required List (5A) Agua Hedionda Creek Bifenthrin Pesticides TMDL Required List (5A) Agua Hedionda Creek Chlorpyrifos Pesticides TMDL Required List (5A) Agua Hedionda Creek Cyfluthrin Pesticides TMDL Required List (5A) Agua Hedionda Creek Cyhalothrin, Lambda Pesticides TMDL Required List (5A) Agua Hedionda Creek Cypermethrin Pesticides TMDL Required List (5A) Agua Hedionda Creek Deltamethrin Pesticides TMDL Required List (5A) Agua Hedionda Creek Indicator Bacteria Pathogens TMDL Required List (5A) Agua Hedionda Creek Malathion Pesticides TMDL Required List (5A) Agua Hedionda Creek Manganese Metals TMDL Required List (5A) Agua Hedionda Creek Nitrogen Nutrients TMDL Required List (5A) Agua Hedionda Creek Phosphorus Nutrients TMDL Required List (5A) Agua Hedionda Creek Pyrethroids Pesticides TMDL Required List (5A) Agua Hedionda Creek Selenium Metals TMDL Required List (5A) Agua Hedionda Creek Total Dissolved Solids (TDS) Salinity/TDS/ Chlorides/Sulfates TMDL Required List (5A) Agua Hedionda Creek Toxicity Total Toxics TMDL Required List (5A) Agua Hedionda Creek Turbidity Sediment TMDL Required List (5A) December 08, 2023 | 10 Identification of Project Site Pollutants Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see Table B.6-1 below): Pollutant Not Applicable to the Project Site Anticipated from the Project Site Also a Receiving Water Pollutant of Concern Sediment X Nutrients P Heavy Metals X Organic Compounds X Trash & Debris X Oxygen Demanding Substances P Oil & Grease X Bacteria & Viruses X Pesticides P Notes: X = Anticipated; P = Potential; see Table B.6-1. Table B.6-1. Anticipated and Potential Pollutants Generated by Land Use Type Priority Project Categories General Pollutant Categories Sediment Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Substances Oil & Grease Bacteria & Viruses Pesticides Detached Residential Development X X X X X X X Attached Residential Development X X X P(1) P(2) P X Commercial Development >1 acre P(1) P(1) X P(2) X P(3) X P(4) P(3) Heavy Industry X X X X X X Automotive Repair Shops X X (3)(5) X X Restaurants X X X X P(1) Hillside Development >5,000 ft2 X X X X X X Parking Lots P(1) P(1) X X P(1) X P(1) December 08, 2023 | 11 Priority Project Categories General Pollutant Categories Sediment Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Substances Oil & Grease Bacteria & Viruses Pesticides Retail Gasoline Outlets X X X X X Streets, Highways & Freeways X P(1) X X(5) X P(3) X X P(1) Notes: X = anticipated; P = potential; ft2 = square feet (1) A potential pollutant if landscaping exists on site. (2) A potential pollutant if the project includes uncovered parking areas. (3) Including solvents. (4) A potential pollutant if land use involves food or animal waste products. (5) Including petroleum hydrocarbons. The yellow cells indicate the land uses associated with the project. Trash Capture BMP Requirements The project must meet the following Trash Capture BMP Requirements (see Section 4.4 of the BMP Design Manual): (1) The trash capture BMP is sized for a 1-year, 1-hour storm event or equivalent storm drain system, and (2) the trash capture BMP captures trash equal to or greater than 5-millimeter particle size. Description / Discussion of Trash Capture BMPs: Besides functioning for primary treatment per city requirements, the proposed BMP (Modular Wetlands System) is also certified by the State Water Resources Control Board as a high-flow capacity trash full-capture system. Hence, trash capture BMP requirements will satisfy city compliance and will be sized accordingly. Hydromodification Management Requirements Do hydromodification management requirements apply (see Section 1.6 of the BMP Design Manual)? □ Yes, hydromodification management flow control structural BMPs required. No, the project will discharge runoff directly to existing underground storm drains that discharge 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 WMAA for the watershed in which the project resides. Description / Additional Information (to be provided if a ‘No’ answer has been selected above): The proposed structural BMP will drain to the existing brine line (63-inch HDPE) which is hard lined from the point of connection to the discharge pond. Hard lined means the conveyance is impervious surface. The 120 million gallons per day (MGD) flow rate along the brine line is very rare and for a short duration. The 60 MGD is the normal maximum flow, dependent on plant operations. The 120 MGD maximum is a rare and extreme event, in which all intake flows are sent back down from the plant, which only occurs if the plant water quality does not meet specifications. This event has occurred only once or twice since 2016. Additionally, the 120 MGD discharge continues for only a short period of time. The maximum discharge that should be considered is 60 MGD, as it is consistent with the more frequent, less intense storm events associated with hydromodification (considering 100- year storm events and the 120 MGD discharge event is consistent with flood control parameters – less frequent but more intense storm events). For these reasons, the project is exempt from hydromodification requirements. The brine line has capacity to convey the 100-year flow rate, except for rare circumstances, and will be used to convey stormwater for the site to the discharge pond. December 08, 2023 | 12 Critical Coarse Sediment Yield Areas* - NOT APPLICABLE *This Section only required if hydromodification management requirements apply Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas exist within the project drainage boundaries? □ Yes No, no critical coarse sediment yield areas to be protected based on WMAA maps If yes, have any of the optional analyses presented in Appendix H of the manual been performed? □ H.6.1 Site-Specific GLU Analysis □ H.7 Downstream Systems Sensitivity to Coarse Sediment □ H.7.3 Coarse Sediment Source Area Verification □ 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? □ No critical coarse sediment yield areas to be protected based on verification of GLUs onsite. □ Critical coarse sediment yield areas exist but additional analysis has determined that protection is not required. Documentation attached in Attachment 8 of the SWQMP. □ Critical coarse sediment yield areas exist and require protection. The project will implement management measures described in Sections H.2, H.3, and H.4 as applicable, and the areas are identified on the SWQMP Exhibit. Discussion / Additional Information: Flow Control for Post-Project Runoff* - NOT APPLICABLE *This Section only required if hydromodification management requirements apply List and describe point(s) of compliance (POCs) for flow control for hydromodification management (see Section 6.3.1). For each POC, provide a POC identification name or number correlating to the project’s HMP Exhibit and a receiving channel identification name or number correlating to the project’s HMP Exhibit. Has a geomorphic assessment been performed for the receiving channel(s)? No, the low-flow threshold is 0.1Q2 (default low flow threshold) □ Yes, the result is the low flow threshold is 0.1Q2 □ Yes, the result is the low flow threshold is 0.3Q2 □ Yes, the result is the low flow threshold is 0.5Q2 If a geomorphic assessment has been performed, provide title, date, and preparer: Discussion / Additional Information: (optional) December 08, 2023 | 13 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. The project will comply with Chapter 7 (Grading, Site Drainage and Low Impact Development Standards) of Volume 1 (General Design Standards) of the City Engineering Standards, 2022 Edition. Optional Additional Information or Continuation of Previous Sections As Needed This space provided for additional information or continuation of information from previous sections as needed. December 08, 2023 | 14 Form E-36 City’s Standard Project Requirement Checklist E-36 Page 1 of 4 Revised 02/22 Development Services Land Development Engineering 1635 Faraday Avenue 442-339-2750 www.carlsbadca.gov STANDARD PROJECT REQUIREMENT CHECKLIST E-36 Project Information Project Name: Project ID: DWG No. or Building Permit No.: Baseline BMPs for Existing and Proposed Site Features Complete the Table 1 - Site Design Requirement to document existing and proposed site features and the BMPs to be implemented for them. All BMPs must be implemented where applicable and feasible. Applicability is generally assumed if a feature exists or is proposed. BMPs must be implemented for site design features where feasible. Leaving the box for a BMP unchecked means it will not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be provided in the area below. The table provides specific instructions on when explanations are required. Table 1 - Site Design Requirement A. Existing Natural Site Features (see Fact Sheet BL-1) 1. Check the boxes below for each existing feature on the site. 1. Select the BMPs to be implemented for each identified feature. Explain why any BMP not selected is infeasible in the area below. SD-G Conserve natural features SD-H Provide buffers around waterbodies Natural waterbodies Natural storage reservoirs & drainage corridors -- Natural areas, soils, & vegetation (incl. trees) -- B. BMPs for Common Impervious Outdoor Site Features (see Fact Sheet BL-2) 1. Check the boxes below for each proposed feature. 2. Select the BMPs to be implemented for each proposed feature. If neither BMP SD-B nor SD-I is selected for a feature, explain why both BMPs are infeasible in the area below. SD-B Direct runoff to pervious areas SD-I Construct surfaces from permeable materials Minimize size of impervious areas Streets and roads Check this box to confirm that all impervious areas on the site will be minimized where feasible. If this box is not checked, identify the surfaces that cannot be minimized in area below, and explain why it is Sidewalks & walkways Parking areas & lots Driveways Patios, decks, & courtyards Hardcourt recreation areas 10341720 Carlsbad Desalination Plant Intake Screening - Phase 2 X Section A Natural waterbodies, natural storage reservoirs & drainage features - The nature of this project requires the desalination plant to be adjacent to the lagoon. Hence, a buffer setback is not applicable. Section B Sidewalks & walkways: The access bridge ramps are not surrounded by pervious areas, and cannot be pervious since they are part of the intake structure. Parking areas & lots: The parking areas will be prioritized to drain to the landscaped areas to the maximum extent practicable, or may be pervious. X X X X X X X CUP 2022-0010 539-8A E-36 Page 2 of 4 Revised 02/22 Other: _______________ infeasible to do so. C. BMPs for Rooftop Areas: Check this box if rooftop areas are proposed and select at least one BMP below. If no BMPs are selected, explain why they are infeasible in the area below. (see Fact Sheet BL-3) SD-B Direct runoff to pervious areas SD-C Install green roofs SD-E Install rain barrels D. BMPs for Landscaped Areas: Check this box if landscaping is proposed and select the BMP below SD-K Sustainable Landscaping If SD-K is not selected, explain why it is infeasible in the area below. (see Fact Sheet BL-4) Provide discussion/justification for site design BMPs that will not be implemented (either partially or fully): Baseline BMPs for Pollutant-generating Sources All development projects must complete Table 2 - Source Control Requirement to identify applicable requirements for documenting pollutant-generating sources/ features and source control BMPs. BMPs must be implemented for source control features where feasible. Leaving the box for a BMP unchecked means it will not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be provided in the area below. The table provides specific instructions on when explanations are required. Table 2 - Source Control Requirement A. Management of Storm Water Discharges 1. Identify all proposed outdoor work areas below Check here if none are proposed 2. Which BMPs will be used to prevent materials from contacting rainfall or runoff? (See Fact Sheet BL-5) Select all feasible BMPs for each work area 3. Where will runoff from the work area be routed? (See Fact Sheet BL-6) Select one or more option for each work area SC-A Overhead covering SC-B Separation flows from adjacent areas SC-C Wind protection SC-D Sanitary sewer SC-E Containment system Other Trash & Refuse Storage Materials & Equipment Storage The proposed electrical building is proposed to drain to the surrounding landscaped areas. The ramp walkways cannot be pervious sincethey are part of the intake structure. The parking areas will be prioritize to drain to the landscaped areas, or may be pervious. Will look into this at 90% submittal. The project proposes one small electrical building. Due to layout of the site around the building, runoff can only drain to surrounding impervious surfaces. Due to limited size, a green roof is not viable. For that same reason, rain barrels are not viable as they would encroach upon the accessible room around the building for operation and maintenance. The project proposes minor new and reconstructed landscaping around the reconstructed small parking area. X X E-36 Page 3 of 4 Revised 02/22 Loading & Unloading Fueling Maintenance & Repair Vehicle & Equipment Cleaning Other: _________________ B. Management of Storm Water Discharges (see Fact Sheet BL-7) Select one option for each feature below: • Storm drain inlets and catch basins … are not proposed will be labeled with stenciling or signage to discourage dumping (SC-F) • Interior work surfaces, floor drains & sumps … are not proposed will not discharge directly or indirectly to the MS4 or receiving waters • Drain lines (e.g. air conditioning, boiler, etc.) … are not proposed will not discharge directly or indirectly to the MS4 or receiving waters • Fire sprinkler test water … are not proposed will not discharge directly or indirectly to the MS4 or receiving waters Provide discussion/justification for source control BMPs that will not be implemented (either partially or fully): X X X X Interior work surfaces, floor drains & sumps: Not applicable. Drain lines: Not applicable. Fire sprinkler test water: Not applicable. E-36 Page 4 of 4 Revised 02/22 Form Certification This E-36 Form is intended to comply with applicable requirements of the city’s BMP Design Manual. I certify that it has been completed to the best of my ability and accurately reflects the project being proposed and the applicable BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the review of this form by City staff is confined to a review and does not relieve me as the person in charge of overseeing the selection and design of storm water BMPs for this project, of my responsibilities for project design. Preparer Signature: Date: Print preparer name: Bill Flores Jr Oct 21, 2022 December 08, 2023 | 15 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). PDP’s subject to trash capture requirements must implement trash capture devices (see Chapter 4 of the BMP Design Manual). Storm water pollutant control, flow control for hydromodification management and trash capture can all 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). December 08, 2023 | 16 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 and trash capture devices, indicate whether pollutant control, trash capture and flow control BMPs are integrated together or separate. To comply with the City BMP Design Manual, the following post-construction stormwater quality practices are considered and incorporated into the proposed Project design: Minimize Impervious Surfaces After demolition of the majority of the forebay structure (impervious surface in pre-project condition), the remaining concrete structure will be filled with concrete. Four feet of soil will be backfilled above the structure. The remaining top 1 foot will be gravel. Any infiltrated runoff will outlet via weepholes along the backfilled structure walls. This will be considered a semi-pervious surface. Landscaped pockets are proposed adjacent to the expanded parking lot, and existing landscaping reconstruction north of the main entrance between the sidewalk and the street right-of-way. Impervious surfaces are minimized where possible and thereby reduce runoff. Optimize Site Layout The site is designed to conform to the existing site features and to minimize those impacts. The landscaped areas are perpetuated as Treatment Control (TC) BMPs for this Project, specifically in DMA 2. Disconnect Discharges Some on-site drainage features will surface flow to landscaped areas before discharging to the corresponding drain inlets. In these cases, there will not be direct discharges to the on-site storm drains. However, in DMA 1, swapped discharge will flow directly to drain inlets, which will drain to the proposed BMP. Self-Retaining Areas There are no self-retaining areas. Existing landscaped areas do not include depressions. The existing bioretention basin (west of the CDP-IPS structure) is not considered since there is no information for its design. Also, tree wells and permeable pavements are not proposed. See the previous related section for more information. Self-Mitigating Areas Landscaped or hydro-seeded areas, where it is difficult to implement TC BMPs due to lack of space or difficulties with grading, are utilized as “self-mitigating” areas provided that these areas are less than 5 percent impervious. Drainages from these areas do not require separate storm water treatment by TC BMPs. Self-mitigating areas are not proposed since no natural or landscaped areas drain directly off site or to the public storm drain system. Minor irrigation system improvements are proposed. The pollutants of concern to be addressed by the TC BMPs will be the ones identified in Table B.6-1. TC BMPs selected for this Project Feasibility of BMPs The project evaluated the feasibility of BMPs based on the order of the required hierarchy. The following is the evaluation. Enhanced Site Design BMPs (Site Design) SD-A, Tree Wells: Since tree wells require runoff at the surface, and runoff to be treated is along the proposed pipe, this BMP is not viable. SD-B, Impervious Area Dispersion: The drainage from DMA 1 cannot be treated via dispersion to landscaped areas prior to or after interception into existing drain inlets. Hence, this BMP is not viable. SD-C, Green Roofs: The site includes an existing electrical building and proposes one as well. However, it is not viable to include a green roof feature into this type of prefabricated building. Not to mention that runoff to be treated is originating from the swapping of area from DMA 1. SD-D, Permeable Pavement: Due to shallow groundwater (less than 10 feet), permeable pavement is not viable. SD-E, Rain Barrels: For reasons stated above under SD-C, Green Roofs, this BMP is not viable. Structural BMPs December 08, 2023 | 17 HU-1, Cistern (Retention, Harvest, and Use): This BMP applies to rooftop areas. This is related to DMA 5. The existing and proposed electrical buildings are one story, but capture-and-use BMP is required when a project proposes habitable structures over nine stories in height. Also, it was demonstrated that 0.25 design control volume (DCV) of DMA 5 (104 cf) is greater than the DCV demand of 1.84 cf (see Attachment 1c for more information). Hence, this BMP does not apply. INF-1, Infiltration Basins; INF-2, Bioretention; INF-3, Permeable Pavement; INF-4, Dry Wells (Retention/Infiltration BMPs): Due to shallow groundwater, these BMPs are not viable for full or partial infiltration. PR-1, Biofiltration with Partial Retention (Partial Retention): Due to shallow groundwater, this BMP is not viable for partial infiltration/retention. BF-1, Biofiltration (Biofiltration): Identified as BMP 2 on the DMA exhibit. This BMP was evaluated for required volume retention. Initially, the biofiltration basin was considered in the existing landscaped area between the sidewalk, small parking lot, and top of slope. Consideration was given to treating the paved area south of the main entrance (between the street right-of-way and DMA 1). This runoff will flow along a storm drain from here (invert 15.7 feet) to the biofiltration area (FS 18.0 feet and invert 15.0 feet). This would equate to 3 feet ponding depth of the biofiltration BMP. Which is greater than the 12-inch maximum ponding depth per this fact sheet. Furthermore, this area was not enough for swapping to meet the requirements, so the deficit runoff would have to be pumped from the proposed storm drain. But, as instructed by the City, pumping runoff from the proposed storm is not viable. Also, it is not viable to reconstruct the impacted areas and non-impacted areas so that the associated runoff surface drains to a proposed at-grade biofiltration feature. Hence, as concurred by the City, this BMP is not viable at this location. Afterwards, a biofiltration basin was considered inside DMA 8 just south of the discharge pond. This basin was evaluated to intercept the runoff from DMA 5 and DMA 8. As it turns out, this basin is sized to treat the required retention volume from the project. The basin is designed to retain the required volume in the ponded area and treat the captured runoff during infiltration through the 18 inches of soil media layer and stored in the aggregate layer. Due to the high groundwater, an impermeable liner will be installed at the bottom of the basin layers. Said filtered runoff ponding at bottom of the liner will gravity drain via an underdrain to the brine line. Any runoff above the basin ponded depth will overflow to the concrete swale at the adjacent access road and ultimately into the brine line. With a factor of safety, the native soil infiltration rate is slow and would not meet the 24 hour drawdown time. Since landscaping is proposed, at least 18 inches of soil media layer would be required, which is assumed to have an infiltration rate of 5 inches per hour. The drawdown time through the soil media layer to the native soil would be 3.6 hours, which meets the drawdown time limitation. This approach was confirmed by an updated geotechnical memorandum which includes an infiltration test and is attached to this report. The proposed basin will not include a filter course layer or, cleanout,. However, it will include the 3:1 side slopes, landscaping, and irrigation system. Hence, as concurred by the city, this BMP is viable at this location for required volume retention. This is in addition to flow-based treatment as discussed below under BF-3. Despite this BMP not meeting the minimum vertical separation between the bottom of the BMP and the groundwater level, the city did not have an issue with locating the BMP at this location. For the reasons stated above, this BMP is viable at this location for required volume retention. BF-2, Nutrient Sensitive Media Design (Biofiltration): This fact sheet focuses on minimizing nutrient export via an underdrain. Since the proposed bioretention basin will not include an overflow structure with an underdrain, this fact sheet does not apply. However, the proposed landscape design utilizes native, drought-tolerant plants and will consider applicable sections of the fact sheet to minimize nutrient export. BF-3, Proprietary Biofiltration Systems (Biofiltration): Identified as BMP 1 on the DMA exhibit. Based on meetings between the City and the San Diego RWQCB, it was decided that the project would use a BF-1 biofiltration basin for volume retention treatment and BF-3 proprietary biofiltration systems for flow-based treatment. This proposed BMP will be a plant-based Modular Wetlands System (MWS) manufactured by Contech. It will use proprietary media and plants to provide treatment and applicable evapotranspiration. This BMP includes two built- in units upstream of the primary treatment unit. First, it includes a pre-treatment unit device built into the structure. Second, it includes a state-certified high-flow capacity trash full-capture system. This trash capture device is reflected on the state list as a Modular Wetland System by Bio Clean Environmental Services, Inc. (October 2022), and will serve to provide required trash capture. The primary treatment unit will treat 1.5 times the DCV as flow- based treatment. Due to the BMP limited head differential (between the inlet and outlet pipe invert), it will be designed as an offline system to the proposed storm drain. Since the BMP is plant-based, it will require slow-drip irrigation to prevent drying of the plants. According to Sections 3.5 and B.4.3 of the BMP Design Manual, if a project DMA cannot be treated or routed to a project BMP due to certain site constraints, an equivalent existing impervious area may be treated in lieu of said project DMA. Since most of the runoff originates from DMA 1 and is conveyed by the proposed storm drain, this December 08, 2023 | 18 runoff from DMA 1 is proposed to be swapped for treatment of the remaining DMAs of the project. See Attachment 1a (DMA exhibit) for more information. The swapped runoff from DMA 1 via the proposed storm drain will be treated by the proposed MWS BMP as discussed above. After treatment, the runoff will continue to the brine line. Again, the swapping of areas is to meet flow-based treatment. The pollutants of concern to be addressed by the TC BMP will be the ones identified in Table B.6-1. The project is exempt from hydromodification requirements as previously mentioned. December 08, 2023 | 19 Structural BMP Summary Information [Contech MWS-L-8-20-11’-8”-V_] Structural BMP ID No. 1 DWG Civil Plans_539-8A______ Sheet No. 14, 15, 21__________ 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) □ Dry Wells (INF-4) □ Partial retention by biofiltration with partial retention (PR-1) □ Biofiltration (BF-1) Proprietary Biofiltration (BF-3) □ Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which on-site retention or biofiltration BMP it serves in discussion section below) □ Detention pond or vault for hydromodification management □ Trash capture device □ Other (describe in discussion section below) Proprietary device Purpose: Pollutant control only □ Hydromodification control only □ Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP Trash capture □ Other (describe in discussion section below) Discussion (as needed): Based on BMP feasibility analysis, this BMP is consistent with BF-3 proprietary biofiltration for flow-based treatment. As mentioned previously, this BMP includes pretreatment and trash capture units upstream of the primary treatment unit. December 08, 2023 | 20 Structural BMP Summary Information [Biofiltration Basin] Structural BMP ID No. 1 BF-1 DWG Civil Plans_539-8A______ Sheet No. 18__________ 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) □ Dry Wells (INF-4) □ Partial retention by biofiltration with partial retention (PR-1) □ Biofiltration (BF-1) □ Proprietary Biofiltration (BF-3) □ Flow-through treatment control included as pre-treatment/forebay for an on-site retention or biofiltration BMP (provide BMP type/description and indicate which on-site retention or biofiltration BMP it serves in discussion section below) □ Detention pond or vault for hydromodification management □ Trash capture device Other (describe in discussion section below) Proprietary device Purpose: □ Pollutant control only □ Hydromodification control only □ Combined pollutant control and hydromodification control □ Pre-treatment/forebay for another structural BMP □ Trash capture Other (describe in discussion section below) Discussion (as needed): Based on BMP feasibility analysis, this BMP is consistent with BF-1 for volume retention required to accommodate lack of volume from MWS. Decembr 08, 2023 Attachment 1: Backup for PDP Pollutant Control BMPs Check which Items are Included behind this cover sheet: Attachment Sequence Contents Checklist Attachment 1a DMA Exhibit (Required) See DMA Exhibit Checklist on the back of this Attachment cover sheet. (24” × 36” exhibit typically required) Included Attachment 1b Tabular Summary of DMAs Showing DMA ID matching DMA Exhibit, DMA Area, and DMA Type (Required)* *Provide table in this Attachment OR on DMA Exhibit in Attachment 1a. Included on DMA Exhibit in Attachment 1a □ Included as Attachment 1b, separate from DMA Exhibit Attachment 1c Form K-7, Harvest and Use Feasibility Screening Checklist (Required unless the entire project will use infiltration BMPs.) Refer to Appendix B of the BMP Design Manual to complete Form K-7. Included □ Not included because the entire project will use infiltration BMPs Attachment 1d Infiltration Feasibility Analysis (Required unless the project will use harvest and use BMPs.) Refer to Appendix D of the BMP Design Manual. Included □ Not included because the entire project will use harvest and use BMPs Attachment 1e Pollutant Control BMP Design Worksheets / Calculations (Required) Refer to Appendices B, E, and I of the BMP Design Manual for structural pollutant control and significant site design BMP design guidelines. Included Attachment 1f Trash Capture BMP Design Calculations Refer to Appendices J of the BMP Design Manual for Trash capture BMP design guidelines. Included (See attachment 1e) □ Not included because the entire project is not subject to trash capture requirements. Attachment 1a DMA Exhibit GG G G 2'' W 2''W 2'' W 2'' W 2''W 2''W 2''W 2''W 2''W 2''W G G G G G G GW GW GW ICB ICB ICBICBICB ICB ICB ICB ICB ICB MMMMMMMMMMMMMMM MMM MMM MMM MMM MMM MMM -2 0 -2 3 -2 2 -2 1 -1 9 - 1 8 -15 -10 -17 -16 -14 -13 -12 -11 -9 17 17 18 19 -20 -24 -23 -22 -21 -1 0 -14 -13 -12 -11 -1 5 -19 -18 -17 -16 2 3 9 1 1 1 3 1 5 1 7 1 9 2 2 2 4 2 3 5 7 9 11 33 32 3028 2624222019 15 14 16 17 18 1 8 1 5 2 0 2 5 3 0 12 1213 13 1 4 1 6 1 7 1 8 1 9 2 1 2 2 2 3 2 4 2 6 2 7 2 8 2 9 3 1 3 2 3 3 3 4 DISCHARGE POND CARLSBAD BLVD ROW EAST RAMP WEST RAMP BRIDGE PROPOSED FLOATING BOOM PROPOSED FINE SCREENING FACILITY INCLUDING SCREENING EQUIPMENT AND DECK ACCESS PROPOSED DEBRIS RETURN PROPOSED BOAT RAMP PROPOSED BOAT RAMP EXISTING ELECTRICAL BUILDING PROPOSED BULKHEAD FOR TUNNEL ISOLATION PROPOSED MARINE RESEARCH PORTABLE CONTAINER PROPOSED DEBRIS BIN AREA ACCESS ROAD PROPOSED STORM DRAIN EXTENSION 18" STORM DRAIN NEW GRAVEL SURFACE EXISTING FOREBAY EXISTING ACCESS ROAD EXISTING ACCESS ROAD A = 91,476 SF (2.1 AC) DMA 1 STORM DRAIN INLET A = 37,756 SF (0.87 AC) DMA 5 PROPOSED FEEDER CONNECTION A = 11,996 SF (0.28 AC) DMA 6A = 1,163 SF (0.027 AC) DMA 7 DMA 4 A = 8,712 SF (0.2 AC) DMA 2A = 16,067 SF (0.37 AC) 35,736 SQUARE FEET OF DMA 1 WILL BE USED FOR SWAPPING DMA 3 A = 4,672 SF (0.11 AC) STORM DRAIN MANHOLE EXISTING CDP-IPS PROPOSED ELECTRICAL BUILDING DMA 8 BMP 1/POC ID 1 POC ID 3 SDSDSDSDSD BMP 2/POC ID 4 Rip rap A = 1,380 SF (0.032 AC) (EQUIVALENT AREA FOR FLOW-BASED TREATMENT) A = 52,166 SF (1.20 AC) EXISTING BIORETENTION POND (PHASE 1) OF 299 B 2 ISSUE DESCRIPTION PROJECT MANAGER PROJECT NUMBER 0 1"2"FILENAME SCALE SHEET DATE C D A 1 3 4 5 6 7 8 CARLSBAD DESALINATION PLANT PHASE 2 INTAKE MODIFICATIONS ISSUED FOR CONSTRUCTION S. FRIEDMAN 10341720 DESIGNED BY CHECKED BY DRAWN BY J. MOYER R. STRATTON D. CELAYA DRAINAGE MANAGEMENT AREA (DMA) EXHIBIT 1" = 40' --- 4 PLAN SCALE: 1" = 40' NOTES 1.HYDROLOGIC SOIL GROUP IS B 2.DEPTH TO GROUNDWATER BELOW GROUND LEVEL IS LESS THAN 5 FEET 3.SEE SSPCBMP EXHIBIT FOR LOCATION OF STRUCTURAL BMPS 4.TREATMENT OF IMPERVIOUS, PERVIOUS, AND SEMI-PERVIOUS SURFACES OF DMA'S 2-7 WILL BE SWAPPED WITH DMA 1 (EQUIVALENT AREA). (FLOW BASED TREATMENT) 5.ALL DMA'S ARE "REQUIRED" UNLESS OTHERWISE NOTED AS "EQUIVALENT". SUCH EQUIVALENT AREAS ARE PROPOSED FOR SWAPPING. (FLOW BASED TREATMENT) 6.DMA 5 AND 8 WILL BE USED FOR RETENTION VOLUME (SEPARATE BMP). DMA 5 IS ALSO INCLUDED FOR FLOW-BASED TREATMENT. EXISTING IMPERVIOUS SURFACE (~ 148,697 SF [3.42 AC]) RECONSTRUCTED IMPERVIOUS SURFACE (~ 25,170 SF [0.58 AC]) NEW IMPERVIOUS SURFACE (~ 4,565 SF [0.11 AC]) DMA LIMITS EXISTING BIORETENTION AREA (~ 161 SF [0.0037 AC]) (PHASE 1) EXISTING LANDSCAPING (~ 27,307 SF [0.63 AC]) RECONSTRUCTED LANDSCAPING (~ 22,003 SF [0.51 AC]) NEW IMPERVIOUS SURFACE OVER LAGOON (~ 6,272 SF [0.15 AC]) NEW SEMI-PERVIOUS SURFACE (~ 10,169 SF [0.23 AC]) NEW PERVIOUS SURFACE OVER LAGOON (~ 6,707 SF [0.15 AC]) SUMMARY OF DMA INFORMATION (FLOW-BASED UNLESS OTHERWISE NOTED) NO. OF DMA'S TOTAL DMA AREA (AC) TOTAL IMPERVIOUS SURFACE (AC) % IMPERVIOUSNESS AREA WEIGHTED RUNOFF COEFFICIENT TOTAL DCV (CF) TOTAL AREA TREATED (AC)NO. OF POCS 8 5.16 3.657 71.8 B 0.9 5424 3.657 4 TABULAR SUMMARY OF DMA'S (FLOW-BASED UNLESS OTHERWISE NOTED) DMA UNIQUE IDENTIFIER* AREA (SF) (AC) IMPERVIOUS SURFACE (AC), EXISTING, NEW, RECONSTRUCTED1 % IMPERVIOUSNESS HSG AREA WEIGHTED RUNOFF COEFFICIENT DCV (CF) DMA 1 91,476 (2.10)2.10 100 B 0.9 3979 DMA 2 16,067 (0.37)0.25 70 B 0.9 140 DMA 3 4,672 (0.11)0.05 50 B 0.9 0 DMA 4 8,712 (0.20)0.10 50 B 0.9 185 DMA 5 37,756 (0.87)0.57 66 B 0.9 1,077 DMA 6 11,996 (0.28)0 0 B 0.9 174 DMA 7 1,163 (0.027)0.027 100 B 0.9 51 DMA 8 52,166 (1.20)0.56 47 B 0.9 - WORKSHEET B-1 (FLOW-BASED UNLESS OTHERWISE NOTED) TREATED BY (BMP ID)POLLUTANT CONTROL TYPE DRAINS TO (POC ID) 1 PROPRIETARY BIOFILTRATION 1 1 PROPRIETARY BIOFILTRATION NONE 1 PROPRIETARY BIOFILTRATION NONE 1 PROPRIETARY BIOFILTRATION 3 1 PROPRIETARY BIOFILTRATION BIOFILTRATION BASIN (RETENTION VOLUME) NONE 1 PROPRIETARY BIOFILTRATION NONE 1 PROPRIETARY BIOFILTRATION NONE 2 BIOFILTRATION BASIN (RETENTION VOLUME)4 LEGEND * THE PROPOSED PERVIOUS AND IMPERVIOUS SURFACES FOR ALL DMA'S WILL BE SWAPPED WITH DMA 1 (EQUIVALENT AREA). PROPOSED PERVIOUS SURFACE AREA (SQUARE FEET) RECONSTRUCTED LANDSCAPE 22,003 NEW LANDSCAPING 0 TOTAL 22,003 PROPOSED IMPERVIOUS SURFACE FOR MITIGATION AREA (SQUARE FEET) RECONSTRUCTED IMPERVIOUS SURFACE 25,170 NEW IMPERVIOUS SURFACE 4,565 TOTAL 29,735 REMOVED IMPERVIOUS SURFACE AREA (SQUARE FEET) FOREBAY 10,169 RIP RAP 1,380 TOTAL 11,549 0 SCALE: 1"=40' 40 80 120 1. THESE VALUES INCLUDE EXISTING IMPERVIOUS SURFACES NOT IMPACTED. ** PROPERTY BIOFILTRATION IS A MODULAR WETLAND SYSTEM (MWS L-8-20-V) FOR TREATMENT (BMP 1) COMBINED WITH A BASIN (BMP 2) TO PROVIDE REQUIRED RETENTION LACKING FROM MWS. 2'' W 2''W 2''W SDM AGUA HEDIONDA LAGOON DISCHARGE POND CARLSBAD BLVD CARLSBAD DESALINATION PLANT B 2 ISSUE DESCRIPTION PROJECT MANAGER PROJECT NUMBER 0 1"2"FILENAME SCALE SHEET DATE C D A 1 3 4 5 6 7 8 CARLSBAD DESALINATION PLANTPHASE 2 INTAKE MODIFICATIONSPRELIMINARY DESIGN S. FRIEDMAN 10341720 DESIGNED BY CHECKED BY DRAWN BY J. MOYER R. STRATTON D. CELAYA EXISTING IMPERVIOUSSURFACE EXHIBIT 1" = 120'-- - PARCEL AREA EXISTING IMPERVIOUS SURFACE (AREA = ~ 39 ACRES) LEGEND PROJECT AREA PROPOSED IMPERVIOUS SURFACE (AREA = 0.55 ACRES) PARCEL AREA BOUNDARY (AREA = 63 ACRES) PLAN SCALE: 1" = 120' THE PURPOSE OF THIS EXHIBIT IS TO DEMONSTRATE HOW THE PROJECT COMPLIES WITH THE 50% RULE. THE PROJECT AREA PROPOSED IMPERVIOUS SURFACE IS LESS THAN 50% OF THE PARCEL AREA EXISTING IMPERVIOUS SURFACE. HENCE, THE PROJECT IS ONLY REQUIRED TO TREAT THE PROJECT AREA PROPOSED IMPERIOUS SURFACE. FOR MORE INFORMATION, REFER TO CITY OF CARLSBAD ENGINEERING STANDARDS, VOLUME 5, BMP DESIGN MANUAL, SECTION 1.7 (SEPTEMBER 1, 2021). Attachment 1b Tabular Summary of DMAs (Included on DMA Exhibit in Attachment 1a) Attachment 1c Form K-7, Harvest and Use Feasibility Screening Checklist Summary of Harvest and Use Feasibility Checklist (Form K-7) This BMP is not applicable for the following reason: the existing and proposed electrical buildings are one story but capture and use evaluation is required when a project proposes habitable structures over 9 stories in height. (Refer to the BMP Design Manual, HU-1 Cistern BMP Fact sheet, and Section B.4.1 Capture and Use Evaluation (page B-28)). But checklist will nevertheless be provided. Section 1 No building indoor water is involved since no habitable buildings exist or are proposed on site. Hence, demand from toilet and urinal flushing is not applicable. Also, there is no program in place to permit the use of storm water for indoor use. Section 2 The location of the proposed electrical building is in DMA 5. DMA 5 includes proposed reconstructed landscaping. The proposed reconstructed landscaping area is about 1,600 square feet (0.04 acres). Related DCV is 416 cf. Per Table B.4-2, we assume the proposed general landscape type is “Hydrozone – Low Plant Water Use” which corresponds to a demand of 390 gallons per irrigated acre per 36 hours. DCV demand = [390 gallons/(irrigated acres)] * (1 cf/7.48 gal) * 1,600 sf (ac/43,560 sf) DCV demand = 1.84 cf DMA 5 DCV = 416 cf, from worksheet B.1 0.25DCV of DMA 5 = 0.25 (416 cf) = 104 cf Hence, 0.25DCV > DCV demand, and Harvest and Use is not feasible. Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B-28 Jan. 2023 Less Common Pollutant Control Calculations This section presents methodologies for performing less common pollutant control calculations including: capture and use evaluation, use of offline BMPs, and BMPs located downstream of a storage unit. Capture and Use Evaluation If the proposed project includes habitable structures over 9 stories in height, the applicant must perform a capture and use evaluation as outlined herein. The capture and use evaluation should be performed at the project-scale, and not be limited to a single DMA. This evaluation must identify the potential demand for using stormwater for indoor toilets and outdoor irrigation use and determine if this demand is sufficient to drawdown the DCV within a 36 hour time period. B.4.1.1 Toilet and Urinal Flushing Demand Calculations* The following guidelines should be followed for computing harvested water demand from toilet and urinal flushing: • If reclaimed water is planned for use for toilet and urinal flushing, then the demand for harvested storm water is equivalent to the total demand minus the reclaimed water supplied, and should be reduced by the amount of reclaimed water that is available during the wet season. • Demand calculations for toilet and urinal flushing should be based on the average rate of use during the wet season for a typical year. • Demand calculations should include changes in occupancy over weekends and around holidays and changes in attendance/enrollment over school vacation periods. • For facilities with generally high demand, but periodic shut downs (e.g., for vacations, maintenance, or other reasons), a project specific analysis should be conducted to determine whether the long term storm water capture performance of the system can be maintained despite shut downs. • Such an analysis should consider the statistical distributions of precipitation and demand, most importantly the relationship of demand to the wet seasons of the year. Table B.4-3 provides planning level demand estimates for toilet and urinal flushing per resident, or employee, for a variety of project types. The per capita use per day is based on daily employee or resident usage. For non-residential types of development, the “visitor factor” and “student factor” (for schools) should be multiplied by the employee use to account for toilet and urinal usage for non- employees using facilities. Note: At the time of publication of this document, there is not a program in place to permit the use of storm water for indoor use. Check with the City of Carlsbad Land Development Department prior to calculating indoor water use. Source: City of Carlsbad Engineering Standards, Volume 5; BMP Design Manual; effective February 16, 2016; revised January 11, 2023 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B-29 Jan. 2023 1 - Based on American Waterworks Association Research Foundation, 1999. Residential End Uses of Water. Denver, CO: AWWARF 2 - Based on use of 3.45 gallons per flush and average number of per employee flushes per subsector, Table D-1 for MWD (Pacific Institute, 2003) 3 - Based on use of 1.6 gallons per flush, Table D-4 and average number of per employee flushes per subsector, Appendix D (Pacific Institute, 2003) 4 - Multiplied by the demand for toilet and urinal flushing for the project to account for visitors. Based on proportion of annual use allocated to visitors and others (includes students for schools; about 5 students per employee) for each subsector in Table D-1 and D- 4 (Pacific Institute, 2003) 5 - Accounts for requirements to use ultra low flush toilets in new development projects; assumed that requirements will reduce toilet and urinal flushing demand by half on average compared to literature estimates. Ultra low flush toilets are required in all new construction in California as of January 1, 1992. Ultra low flush toilets must use no more than 1.6 gallons per flush and Ultra low flush urinals must use no more than 1 gallon per flush. Note: If zero flush urinals are being used, adjust accordingly. Table B.4-1: Toilet and Urinal Water Usage per Resident or Employee Land Use Type Toilet User Unit of Normalization Per Capita Use per Day Visitor Factor4 Water Efficiency Factor Total Use per Resident or Employee Toilet Flushing1,2 Urinals3 Residential Resident 18.5 NA NA 0.5 9.3 Office Employee (non-visitor) 9.0 2.27 1.1 0.5 7 (avg) Retail Employee (non-visitor) 9.0 2.11 1.4 0.5 Schools Employee (non-student) 6.7 3.5 6.4 0.5 33 Various Industrial Uses (excludes process water) Employee (non-visitor) 9.0 2 1 0.5 5.5 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B-30 Jan. 2023 B.4.1.2 Planning Level Irrigation Demands To simplify the planning process, the method described above has been used to develop daily average wet season demands for a one-acre irrigated area based on the plant/landscape type. These demand estimates can be used to calculate the drawdown of harvest and use systems for the purpose of LID BMP sizing calculations. Table B.4-2: Planning Level Irrigation Demand by Plant Factor and Landscape Type General Landscape Type 36-Hour Planning Level Irrigation Demand (gallons per irrigated acre per 36 hour period) Hydrozone – Low Plant Water Use 390 Hydrozone – Moderate Plant Water Use 1,470 Hydrozone – High Plant Water Use 2,640 Special Landscape Area 2,640 BMPs Downstream of a Storage Unit Incorporation of upstream storage units (cisterns, vaults, etc) into a project’s design can regulate flows to downstream biofiltration BMPs and potentially optimize the required BMP footprints. Use of this approach is not supported by County automated worksheets, but compliance with stormwater pollutant control requirements can be demonstrated through the following steps. • Step 1) Determine the flow rate from the upstream storage unit o Use the orifice equation to determine outflow from the storage unit when it is filled to the depth associated with the DCV. • Step 2) Demonstrate that the proposed BMP can accommodate flows from the storage unit o Multiply the BMP surface area (ft2) by the filtration rate of the biofiltration soil media (in/hr) and divide by 43,200 to convert the units into CFS. For proprietary BMPs, this rate should correspond with the rates from certified testing the manufacturer has performed. • Step 3) Demonstrate that the proposed BMP biofilters 92% of the annual runoff volume o If continuous simulation modeling has been performed, provide output reports from SWMM or SDHM modeling. o If continuous simulation modeling has not been performed, reference the percent capture nomographs in Figure B.3-1 to determine the percentage of annual runoff that is biofiltered. To use the nomographs, applicants must represent the BMP storage capacity as a fraction of the DCV along the x-axis, trace a line vertically to the colored Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B-31 Jan. 2023 line representing the drawdown time of the system, and then determine the percentage of annual runoff biofiltered by tracing horizontally to the y-axis. • Step 4) If the downstream biofiltration BMP is <3% of the effective tributary area, provide information supporting use of compact biofiltration as generally outlined below. o Retention Requirements: Demonstrate that minimum retention requirements from Section B.2 are satisfied. o Proprietary Requirements (if applicable): Provide proprietary information demonstrating that the device meets biofiltration criteria outlined in Appendices F.1- F.2. DMA Swapping If desired, a PDP applicant may generate stormwater pollutant control and/or hydromodification flow control benefits by managing stormwater flows from “excess areas” that are conveyed to the site. Management of flows from these excess areas may be used to offset flows from “required areas” that lack management. Required areas are the areas of a project for which the Permit mandates pollutant control and/or HMP flow control requirements. Excess areas are the areas of a project for which the Permit does not mandate pollutant control and/or HMP flow control requirements. Areas of offsite run-on to the PDP site may always be considered excess areas. Additionally, for redevelopment projects falling under the 50% redevelopment threshold, onsite areas that are not being redeveloped may also be considered excess areas. Compliance with stormwater pollutant control requirements using this onsite alternative compliance approach can be demonstrated as outlined below. • Step 1) Determine the untreated DCV from the required area • Step 2) Determine the treated DCV from the excess area o If required areas and excess areas contain different land uses, a land use factor must be applied to account for variations in pollutant concentrations. In most cases, this factor results in a lower treatment volume being credited. • Step 3) Demonstrate compliance o Show that the treated DCV from the excess area is greater than or equal to the untreated DCV from the required area (Step 2 ≥ Step 1). o Use of this onsite alternative compliance approach does not mandate flow-thru treatment of untreated flows from required areas; however, applicants are encouraged to do so where feasible. Appendix K: Forms and Checklists K-2 Jan. 2023 Harvest and Use Feasibility Checklist Form K-7 1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during the wet season? Toilet and urinal flushing Landscape irrigation Other:______________ 2. If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section B.3.2. [Provide a summary of calculations here] 3. Calculate the DCV using worksheet B-2.1. DCV = __________ (cubic feet) 3a. Is the 36 hour demand greater than or equal to the DCV? Yes / No 3b. Is the 36 hour demand greater than 0.25DCV but less than the full DCV? Yes / No 3c. Is the 36 hour demand less than 0.25DCV? Yes 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. Harvest and use may be feasible. Conduct more detailed evaluation and sizing calculations to determine feasibility. Harvest and use may only be able to be used for a portion of the site, or (optionally) the storage may need to be upsized to meet long term capture targets while draining in longer than 36 hours. Harvest and use is considered to be infeasible. Is harvest and use feasible based on further evaluation? Yes, refer to Appendix E to select and size harvest and use BMPs. No, select alternate BMPs. Note: 36-hour demand calculations are for feasibility analysis only. Once feasibility analysis is complete the applicant may be allowed to use a different drawdown time provided they meet the 80% annual capture standard (refer to B.4.2) and 96-hour vector control drawdown requirement. Source: City of Carlsbad Engineering Standards, Volume 5; BMP Design Manual; effective February 16, 2016; revised January 11, 2023 X See attached summary for backup to this checklist. X X See attached summary for backup calcs Attachment 1d Infiltration Feasibility Analysis Page 1 Technical Memorandum Date: Wednesday, November 15, 2023 Project: Carlsbad Desalination Plant (CDP) Intake Phase 2 To: Janelle Moyer, PE (HDR Internal) From: Jim Starick, PE. Mario Flores, PE, and Manuel Guzman, PE Subject: Onsite Infiltration Test Results and Recommendations Carlsbad Desalination Plant Intake Phase 2 Introduction We have developed this Technical Memorandum (TM) to summarize the results of our onsite infiltration testing and present our recommendations for the planned stormwater management for the subject project. The City of Carlsbad requested that infiltration testing to be performed at a proposed biofiltration basin site per the City’s grading permit requirements. HDR previously prepared a TM which included recommendations for the feasibility of biofiltration basin locations within the project site (HDR, 2023a). Based on the recommendations of that TM, the selected location for the proposed biofiltration basin was deemed potentially not feasible. The proposed biofiltration basin is located on the west side of the project site adjacent to Carlsbad Boulevard. Generally, the dimensions of the proposed biofiltration basin consist of an approximate length of 19 feet and a width of about 6 feet. The finished bottom elevation of the proposed biofiltration basin is at about 9 feet National Geodetic Vertical Datum of 1929 (NGVD 29). About 1.5 feet below the finished bottom will be excavated and replaced with a filtering soil fill. The location of the proposed biofiltration basin is shown on the Site Map on Exhibit 1. Field Investigation The contractor (Kiewit-Shea Joint Venture [KSJV]) prepared the site for the hand auger boring by excavating to an elevation of about 9 feet NGVD 29, matching the elevation of the proposed finished bottom of the basin. The ground surface elevations were not confirmed by HDR during the field investigation. Additionally, KSJV cleared all utilities and informed the Underground Service Alert of the proposed excavation. HDR advanced a single hand auger boring (designated as HA-23-006) within the proposed basin footprint at the location prepared by KSJV. The hand auger consisted of a 3.5-inch bit diameter and was advanced to a depth of about 5.8 feet below ground surface (bgs) (corresponding to elevation of about 3.2 feet NGVD 29). The borehole was then prepared for infiltration testing by installing a 1-3/8”-inside-diameter slotted PVC pipe and filling the bottom of the hole and annular space with packed pea gravel. After the infiltration testing was completed (see details on testing later in this TM), the borehole was backfilled with soil cuttings and the ground surface restored to its original condition. Page 2 Subsurface Conditions Subsurface conditions within the hand auger boring consisted of fill material to the maximum depth explored of about 5.8 feet bgs. Additionally, fill was encountered in the vicinity of the proposed basin to depths ranging 3 feet to 18 feet bgs in previous explorations conducted by Ninyo & Moore (2016). The upper 2.5 feet of soil, excavated by KSJV prior to hand augering, consisted of sandy clay with gravel. Generally, the fill material encountered in the hand auger boring consisted of about 1.7 feet of poorly-graded sand with silt underlain by about 2.5 feet of poorly-graded sand, and clayey sand thereunder to the maximum depth explored. Minor amounts of gravels and cobbles were encountered throughout the exploration. Seashells were also encountered in the boring. The location of the hand auger boring is shown on Boring Location Map on Exhibit 2 and the boring log is presented on Exhibits 3 and 4. A more detailed description of subsurface conditions at the project site is included in the Geotechnical Design Report prepared by HDR (2023b). Groundwater Groundwater was not encountered within our shallow hand auger boring for this investigation, however it was noted that moisture increased with depth. Additionally, groundwater was documented during our previous investigation for the project (HDR, 2023) and encountered between approximate elevations of -2 and -6 NGVD 29. A design groundwater elevation of +5 feet NGVD 29 (corresponding to a depth of about 4 feet below the proposed basin finished bottom) was recommended in the report by HDR (2023b) due to anticipated tidal wave influences. Therefore, groundwater levels are expected to be very near the bottom of the test boring and infiltration test zone. Infiltration Testing Infiltration testing was completed in general accordance with the Borehole Percolation Test method per the City of Carlsbad BMP Design Manual (2023) with reference to the Riverside County Low Impact Development BMP Design Handbook (2011) test method. The tested zone was presoaked prior to starting the infiltration testing. Due to the coarse nature of the onsite soils, water completely infiltrated within a few minutes, therefore, the time required for the water level to drop a fixed depth (between 16 and 22 inches bgs) was recorded over several trials to determine a percolation rate. The water level was selected to minimize influence of the upper clayey fill layer which is expected to be removed during final grading and construction. The water was refilled to the same level after each reading. As shown in Table 1, the test data was converted to a vertical infiltration rate using the conversion equation presented in the Riverside County guidelines (2011). Percolation test data is presented on Exhibit 5. Table 1. Infiltration Test Data Summary Test Location Test Depth (inches) Infiltration Rate (in/hr) Soil Type HA-23-006 16 to 70 4.0 Poorly-graded Sand, Clayey Sand with varying amount of gravel Page 3 The infiltration rate presented in Table 1 does not include a factor of safety. A factor of safety of at least 3.0 is recommended by the Riverside County guidelines (2011). The designer should apply an appropriate factor of safety based on the selected method of infiltration. It is noted that the infiltration rate (unfactored) measured onsite is high compared to the maximum infiltration rate for infiltration devices recommended by Caltrans (2020). However due to the nature of an isolated test in a highly permeable soil, it is expected that this infiltration rate is dominated by a highly permeable sand layer between about elevation 1.5 and 4.5 feet (NGVD 29), with a large amount of lateral water conductivity. A larger scale infiltration area such as the one proposed is expected to rapidly saturate this layer and the infiltration rate will likely decrease substantially. This saturation should be expected after about 12-24 inches of infiltration has occurred within the basin during a single event. Analysis of Infiltration Site Potential The restriction elements listed in Table D.1-1 of Carlsbad’s Engineering Standards (2021) were considered to evaluate the proposed site as a potential infiltration site. This table template is attached on Exhibit 6. Taking into consideration the restrictions specified in the City guidelines, infiltration is restricted at the project site. The restrictions that are applicable or potentially applicable are described in more detail below: • “BMP is within 10 feet of Groundwater Table” – The design groundwater table for the Project site is at elevation +5 feet NGVD 29. The proposed bottom of basin elevation is +9 feet NGVD 29, therefore it lies within 10 feet of groundwater. The high groundwater level would need to be at an elevation or -1 feet NGVD 29 or lower. Based on where groundwater was encountered during previous explorations, it’s possible that actual groundwater level at the basin site is near -1 feet NGVD 29. However due to the proximity to the ocean and influence from tidal levels, it is unconservative to assume groundwater is continuously at or below -1 feet NGVD 29. • “BMP is within highly liquefiable soils and has connectivity to structures” – Liquefiable soils have been identified on the Geotechnical Design Report (HDR, 2023b), and various structural features exist in the area. An infiltration BMP may increase the groundwater elevation locally and therefore increase risks of damage due to liquefaction to structural features at the Project site. • “BMP is within fill depths of >= 5 feet” – Fill exists at the site and is noted in relevant soil borings to depths of at least 15 feet below grade (HDR, 2023b). Fill is expected throughout most of the area due to previous activities including the construction of existing inlet tunnels, paved areas, and utilities. • “BMP is within 10 feet of underground utilities and sewer utilities” – As denoted in the project plans, an underground electrical line exists near the proposed basin. Page 4 Conclusions and Recommendations Based on the above discussion, various infiltration restrictions exist at the proposed basin location. It is our engineering recommendation that proposed basin does not employ ground- source infiltration methods, i.e. it should be lined to prevent the intentional introduction of water into the ground, unless specifically recommended or approved by the Regional Water Quality Control Board. If ground-source infiltration is constructed onsite, the influence of added groundwater on subsurface improvements, increased risk of liquefaction, and potential damage to at-grade infrastructure should be considered. The excavated bottom of the proposed basin (below filtering backfill) should be located within the sandy material (located at about elevation 4.5 feet NGVD 29). Any fine-grained materials are encountered at the bottom of the excavation should be removed and replaced with granular backfill. Soil at the finished bottom of the proposed basin should not be compacted and should be inspected during construction by HDR or our geotechnical representative for consistency with the design recommendations herein. With time, the bottoms of infiltration systems tend to plug with organics, sediments, and other debris. Long term maintenance will likely be required to remove these deleterious materials to maintain design percolation rates. Attachments • Exhibits References City of Carlsbad, 2021, Engineering Standards Volume 5; BMP Design Manual, effective February 16, 2016, revised September 1, 2021. Caltrans, 2020, Infiltration Basin Design Guidance. December. County of Riverside, 2011, Low Impact Development BMP Design Handbook, revised September. HDR, 2023a, Technical Memorandum, Infiltration Recommendations, Carlsbad Desalination Plant Intake Phase 2, Poseidon Water, Carlsbad, CA, April. HDR, 2023b, Geotechnical Design Report, Carlsbad Desalination Plant Intake Phase 2, Poseidon Water, Carlsbad, CA, January. Ninyo & Moore, 2016, Geotechnical Evaluation, New Intake/Discharge Structure, Carlsbad Seawater Desalination Plant, 4600 Carlsbad Boulevard, Carlsbad, California, dated November 30. 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COMP. STRENGTH (TSF) COBBLES GRAVEL RELATIVE DENSITY FI N E - G R A I N E D S O I L S >5 0 % P A S S E S NO . 2 0 0 S I E V E CONSISTENCY SAND MEDIUM PENETRATION RESISTANCE FINE VERY LOOSE LOOSE MEDIUM DENSE DENSE VERY DENSE STABILIZED WATER LEVEL MEASUREMENT(WITH DATE) PRIMARILY ORGANIC MATTER, DARK IN COLOR, AND ORGANIC ODOR OTHER SYMBOLS WELL-GRADED GRAVEL POORLY-GRADED GRAVEL SILTY GRAVEL CLAYEY GRAVEL WELL-GRADED SAND POORLY-GRADED SAND SILTY SAND CLAYEY SAND LEAN CLAY SILT ORGANIC CLAY OR SILT FAT CLAY ELASTIC SILT ORGANIC CLAY OR SILT COMPONENTPERCENTAGE FINE SILTS ANDCLAYS CRITERIA FOR ASSIGNING SOIL GROUP NAMES GROUPSYMBOL SANDS >50% OF COARSEFRACTION PASSESNO 4. SIEVE UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D-2487) 1040200 WELL Concrete Grout/Fill Bentonite/Grout Seal Sand Pack + Solid Pipe Sand Pack + Slotted Pipe GRAIN SIZES MATERIALS Asphalt Aggregate Base Boulders & Cobbles Fill Topsoil MATERIALTYPES HIGHLY ORGANIC SOILS INCREASING VISUALMOISTURE CONTENT COARSECOARSE CLEAN SANDS <5% FINES GRAVELS WITH FINES >12% FINES INORGANIC BLOWS/FOOT (N60) SILTS AND CLAYS LIQUID LIMIT<50 SILTS AND CLAYS LIQUID LIMIT>50 INORGANIC SANDS AND FINES >12% FINES Cu 4 AND 1 Cc 3 Cu < 4 AND/OR 1 > Cc > 3 FINES CLASSIFY AS ML OR MH FINES CLASSIFY AS CL OR CH Cu 6 AND 1 Cc 3 Cu < 6 AND/OR 1 > Cc > 3 FINES CLASSIFY AS ML OR MH FINES CLASSIFY AS CL OR CH PI>7 AND PLOTS>"A" LINE PI>4 AND PLOTS<"A" LINE LL (oven dried)/LL (not dried)<0.75 PI PLOTS >"A" LINE PI PLOTS <"A" LINE LL (oven dried)/LL (not dried)<0.75 SILT & CLAY U.S. STANDARDSIEVE 12"3"3/4" GRAVELS >50% OF COARSE FRACTION RETAINED ON NO 4. SIEVE SAND & GRAVEL 4 0 - 1 2 - 4 5 - 8 9 - 15 16 - 30 OVER 30 NOTES VERY SOFT SOFT MEDIUM STIFF STIFF VERY STIFF HARD 0 - 1/4 1/4 - 1/2 1/2 - 1 1 - 2 2 - 4 OVER 4 WET MOISTDRY MOSTLY SOME LITTLEFEW TRACE >50% 30 - 50% 15 - 29%5 - 14% <5% bgs c CD CN CR CU DS EI HY MD N60PI PR RV SA SE TC TR UC UU BELOW GROUND SURFACE COHESION CONSOLIDATED DRAINED TRIAXIAL CONSOLIDATION CORROSIVITY CONSOLIDATED UNDRAINED TRIAXIAL DIRECT SHEAR EXPANSION INDEX HYDROMETER MAX DENSITY (COMPACTION) BLOW COUNT, Corrected for Hammer Energy Only PLASTICITY INDEX PERMEABILITY R-VALUE SIEVE ANALYSIS SAND EQUIVALENT CYCLIC TRIAXIAL TIME RATE OF CONSOLIDATION UNCONFINED COMPRESSION UNCONSOLIDATED UNDRAINED TRIAXIAL SOIL GROUP NAMES & LEGEND SAMPLERS SPT (2" OD) Modified California (3" OD) California (2.5" OD) Bulk Shelby Tube HQ Core Sonic Core INITIAL WATER LEVEL MEASUREMENT(WITH DATE) CO A R S E - G R A I N E D S O I L S >5 0 % R E T A I N E D O N NO . 2 0 0 S I E V E PEAT ORGANIC ORGANIC GW GP GM GC SW SP SM SC CL ML OL CH MH OH PT CLEAN GRAVELS <5% FINES 0 - 4 5 - 9 10 - 29 30 - 49 50 + NUMBER OF BLOWS OF 140 LB HAMMER FALLING 30 INCHES TO DRIVE A 2 INCH O.D. (1-3/8 INCH I.D.) SPLIT-BARREL SAMPLER THE LAST 12 INCHES OF AN 18-INCH DRIVE (ASTM-1586 STANDARD PENETRATION TEST). FOR FINE-GRAINED SOILS, STRENGTH TESTS ARE USED AS PRIORITY TO BLOW COUNT. 0 10 20 30 40 50 60 70 80 90 100 110 120 0 10 20 30 40 50 60 70 80 PL A S T I C I T Y I N D E X ( % ) 74 PLASTICITY CHART LIQUID LIMIT (%) LE G E N D 2 0 2 1 - 0 8 P O S E I D O N A G U A H E D I O N D A L A G O O N . G P J F O L S O M 3 - 3 0 - 1 1 . G D T 1 1 / 9 / 2 3 MH & OH "U" L I N E PI = 0 . 9 ( L L - 8 ) PI = 0.7 3 ( L L - 2 0 ) "A" L I N E ML & OL CH & OH CL-ML CL & OL 3 Poorly-graded SAND with SILT (SP-SM); olivebrown; moist; medium to fine SAND; traceCLAY; few rounded COBBLES and GRAVEL;(FILL) Poorly-graded SAND (SP); light grayish brown;moist; fine SAND; coarse GRAVEL; trace fineGRAVEL; trace sea shells; (FILL) Clayey SAND (SC); brown; moist; medium tofine SAND; low plasticity CLAY; increasedmoisture; trace rounded COBBLE (4 inches indiameter); (FILL) Boring terminated at 5.8 feet below groundsurface (bgs).No groundwater encountered. Hand auger boring converted to Percolation Teston 11/2/2023. PVC pipe ( 1-3/8 inch diameter)and gravel used in annulus. Boring backfilled with soil cuttings. BIT DIAMETER:3.5" DATE: START 11/2/23 END 11/2/23 DATE: DRILL METHOD:Hand LOGGED BY:MF TIME: DEPTH: BOREHOLE DEPTH (ft):5.8 LATITUDE:33.13843 ELEVATION (ft):10 CHECKED BY (DATE):TH STATION & OFFSET:NA, NA X DEPTH:GROUNDWATER DATA: NOT ENCOUNTERED DRILLING COMPANY:HDR HAMMER EFFICIENCY:% EFFICIENCY MEASURED GW NOT MEASURED TIME: DATE: DRILL RIG: CASING TIP DEPTH:NA HAMMER TYPE: LONGITUDE:-117.33874 % F I N E S DE P T H ( f t ) EL E V A T I O N ( f t ) Boring Log REMARKS SA M P L E R SA M P L E N O . / CO R E R U N FI E L D B L O W S / 6 i n PO C K E T P E N ( k s f ) DR Y D E N S I T Y ( p c f ) MO I S T U R E CO N T E N T ( % ) OT H E R T E S T S MA T E R I A L GR A P H I C Boring HA-23-006 DESCRIPTION HD R B O R I N G L O G I R V I N E 2 0 2 1 - 0 8 P O S E I D O N A G U A H E D I O N D A L A G O O N . G P J F O L S O M 3 - 3 0 - 1 1 . G D T 1 1 / 9 / 2 3 Date Exhibit 4Carlsbad Seawater Desalination Plant (CDP) Intake Phase 2Carlsbad, CA 0 55 NOV 2023 Project: Poseidon Calculated By: MF Checked By: JMS Date: 11/2/2023 Project Name: Location or Name: Depth to bottom of boring (ft)5.80 Boring Diameter (in)3.5 Radius (in)1.75 Pipe dia (in)*1.375 Gravel Pack Void Ratio 0.5 Total Void Ratio (Calculated)0.577 Infiltration Rate Initial Final (in/hr) 1 1.33 1.83 34.00 6.00 50.60 6.23 2 1.33 1.83 39.00 6.00 50.60 5.43 3 1.33 1.83 40.00 6.00 50.60 5.30 4 1.33 1.83 53.00 6.00 50.60 4.00 5 1.33 1.83 58.00 6.00 50.60 3.65 6 1.33 1.83 40.00 6.00 50.60 5.30 7 1.33 1.83 54.00 6.00 50.60 3.92 8 1.33 1.83 48.00 6.00 50.60 4.41 9 1.33 1.83 38.00 6.00 50.60 5.58 10 1.33 1.83 43.00 6.00 50.60 4.93 11 1.33 1.83 48.00 6.00 50.60 4.41 12 1.33 1.83 49.00 6.00 50.60 4.32 13 1.33 1.83 52.00 6.00 50.60 4.08 14 1.33 1.83 61.00 6.00 50.60 3.47 15 1.33 1.83 53.00 6.00 50.60 4.00 * - Pipe diameter used to account for gravel displacement of water. Poseidon HA-23-006 Depth to Water (ft) Reading # Δ Time (sec) Avg H (in)Δ H (in) Field Percolation Test Results - Exhibit 5 $SSHQGL['*HRWHFKQLFDO(QJLQHHU$QDO\VLV '6HSW Appendix D Geotechnical Engineer Analysis Analysis of Infiltration Restrictions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·RI&RQWDPLQDWHG6RLOV %03LVZLWKLQ·RI,QGXVWULDO$FWLYLWLHV/DFNLQJ6RXUFH&RQWURO %03LVZLWKLQ·RI:HOO*URXQGZDWHU%DVLQ %03LVZLWKLQ·RI6HSWLF7DQNV/HDFK)LHOGV %03LVZLWKLQ·RI6WUXFWXUHV7DQNV:DOOV %03LVZLWKLQ·RI6HZHU8WLOLWLHV %03LVZLWKLQ·RI*URXQGZDWHU7DEOH %03LVZLWKLQ+\GULF6RLOV %03LVZLWKLQ+LJKO\/LTXHILDEOH6RLOVDQGKDV&RQQHFWLYLW\WR6WUXFWXUHV %03LVZLWKLQ7LPHVWKH+HLJKWRI$GMDFHQW6WHHS6ORSHV &RXQW\6WDIIKDV$VVLJQHG´5HVWULFWHGµ,QILOWUDWLRQ&DWHJRU\ 2SWLRQDO &RQVLGHUDWLRQV %03LVZLWKLQ3UHGRPLQDQWO\7\SH'6RLO %03LVZLWKLQ·RI3URSHUW\/LQH %03LVZLWKLQ)LOO'HSWKVRI·([LVWLQJRU3URSRVHG %03LVZLWKLQ·RI8QGHUJURXQG8WLOLWLHV %03LVZLWKLQ·RI(SKHPHUDO6WUHDP 2WKHU3URYLGHGHWDLOHGJHRWHFKQLFDOVXSSRUW 5HVXOW %DVHGRQH[DPLQDWLRQRIWKHEHVWDYDLODEOHLQIRUPDWLRQ ,KDYHQRWLGHQWLILHGDQ\UHVWULFWLRQV DERYH 8QUHVWULFWHG %DVHGRQH[DPLQDWLRQRIWKHEHVWDYDLODEOHLQIRUPDWLRQ ,KDYHLGHQWLILHGRQHRUPRUHUHVWULFWLRQV DERYH 5HVWULFWHG 7DEOH'LVGLYLGHG LQWR0DQGDWRU\ &RQVLGHUDWLRQVDQG2SWLRQDO&RQVLGHUDWLRQV0DQGDWRU\ 6RXUFH &LW\ RI &DUOVEDG (QJLQHHULQJ 6WDQGDUGV 9ROXPH %03 'HVLJQ 0DQXDO HIIHFWLYH )HEUXDU\ UHYLVHG 6HSWHPEHU 1R 1R No <HV <HVNo <HV <HV [ 1R 1R Yes 1R 1R 1R 1R 1R 1R Exhibit 6 Technical Memorandum Date: Thursday, April 27, 2023 Project: Carlsbad Desalination Plant (CDP) Intake Phase 2 To: Janelle Moyer, PE (HDR Internal) From: Jim Starick, PE and Matthew Dennerline, PE, GE Subject: Infiltration Recommendations We have developed this technical memorandum to summarize our recommendations for the planned stormwater management for the subject project. The impacted project area is divided into various drainage management areas (DMA) as indicated on Figure 1, attached. We understand that proposed infiltration structural Best Management Practice (BMP) features have been considered, as indicated numerically on Figure 1. A review of available soil data as well as site constraints has been performed to form conclusions and recommendations on what infiltration methods should be considered viable at the site. For a full presentation of existing subsurface and other relevant geotechnical data, please refer to the Geotechnical Design Report performed by HDR (2023). Our conclusions were compared against the restriction elements listed in Table D.1-1 of Carlsbad’s Engineering Standards (2021). This table template is attached on Figure 2 for reference. Infiltration Areas The site is divided into five DMAs as indicated on Figure 1, attached. These areas are summarized as follows: 1. DMA 1 consists of existing impervious surface (pavement) which is not owned or leased and therefore not viable for infiltration BMP features. 2. DMA 2 is an inherited landscaped area with no planned modifications, and therefore not planned for BMP features. 3. DMA 3 is a potentially viable BMP site where construction is planned and discussed in more detail below. 4. DMA 4 has no ownership or lease rights, and is located on a slope, and is therefore not viable for infiltration BMP features. 5. DMA 5 is an existing impervious surface (pavement) to be restored to pavement after construction. Additionally, it is located at the shoreline of Agua Hedionda Lagoon with minimal separation to groundwater, adjacent to existing structures, and is not viable for infiltration. 6. DMA 6 consists of a new semi-pervious surface to replace the existing impervious surface within the Easement T area. Area is not viable for infiltration due to the presence of underground utilities and other abandoned underground improvements. 7. DMA 7 consists of new impervious surface over the lagoon. It is located at the shoreline of Agua Hedionda Lagoon with minimal separation to groundwater, adjacent to existing structures, and is not viable for infiltration. 8. DMA 8 consists of existing landscape with no planned modifications, and therefore not planned for BMP features, and is also adjacent to the property line and a public roadway. Therefore, it is not considered viable for infiltration. The sole DMA that is potentially viable for infiltration-based BMP features is DMA 3. However, several infiltration restrictions exist per the guidance of Carlsbad’s Engineering Standards (2021, see Figure 2). The restrictions that are applicable or potentially applicable are described in more detail below: • “BMP is within 10 feet of Structures/Tanks/Walls” – Several locations within DMA 3 are within 10 feet of structures or walls. Existing buried water inlet tunnels traverse the area, and proposed walls exist near the western limit at the proposed electrical building. These features must be avoided for infiltration BMP features to be considered viable. • “BMP is within 10 feet of Groundwater Table” – The design groundwater table in this area is at elevation +5 feet NAVD88. The ground elevation within DMA 3 varies, but to be viable any infiltration features should have invert elevations no lower than +15 feet NAVD 88 which may limit their size or practicality. • “BMP is within highly liquefiable soils and has connectivity to structures” – Liquefiable soils have been identified on the Geotechnical Report, and as discussed in the first bullet above various structural features exist in the area. For this reason we do not recommend infiltration BMP features that may increase water tables locally and therefore increase risks of damage due to liquefaction. • “BMP is within 1.5 times the height of adjacent steep slopes (>=25%)” – Slopes steeper than 25 percent exist on the center and west sides of DMA 3 and therefore should be avoided, significantly reducing the viable area of DMA 3. • “BMP is within fill depths of >= 5 feet” – Fill exists on the site and is noted in relevant soil borings to depths of at least 15 feet below grade. Fill is expected throughout most of the area due to previous activities including construction of the existing inlet tunnels, paved areas, and utilities. • “BMP is within 10 feet of underground utilities” – This statement is true at various locations across DMA 3, including areas above the inlet tunnels as well as minor utilities such as electrical. Conclusions and Recommendations Based on the above discussion, various infiltration restrictions exist at each DMA. Additional engineering and logistical restrictions exist at various DMAs such as property ownership. It is our engineering recommendation that BMPs selected for use at the site do not employ ground-source infiltration methods, i.e. they should be enclosed or lined to prevent the intentional introduction of water in the areas discussed herein. Other treatment-based BMPs may be considered that do not allow for onsite infiltration. Figures Figure 1 – Drainage Management Area (DMA) Exhibit Figure 2 – City of Carlsbad BMP Design Manual Considerations Table References City of Carlsbad, 2021, Engineering Standards Volume 5; BMP Design Manual, effective February 16, 2016, revised September 1, 2021. GeoLogic Associates, 2008, Geotechnical/Environmental Report, Proposed Carlsbad Desalination Project, Reconfigured Site, Encina Generating Station, Carlsbad, California, dated September 22. HDR, 2023, Geotechnical Design Report, Carlsbad Deslaination Plant Intake Phase 2, Poseidon Water, Carlsbad, CA, January. Ninyo & Moore, 2013, Geotechnical Evaluation, Carlsbad Seawater Desalination Plant (Intake Pump Station Site), 4600 Carlsbad Boulevard, Carlsbad, California, dated August 20. Ninyo & Moore, 2016, Geotechnical Evaluation, New Intake/Discharge Structure, Carlsbad Seawater Desalination Plant, 4600 Carlsbad Boulevard, Carlsbad, California, dated November 30. GG G G 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W G G G G G G GW GW GW ICB ICB ICBICBICB ICB ICBICBICBICB -2 0 -23 -22 -21 -1 9 -1 8 -15 -10 -17 -16 -14 -13 -12 -11 -9 17 17 18 19 -20 -24 -23 -22 -21 -10 413-12-11 -15 -19 -18 -17 -16 2 3 9 11 1 3 1 5 17 1 9 2 2 2 4 23579 11 33 323028 2624222019 15 16 17 18 18 1 5 2 0 2 5 3 0 12 1213 13 1 4 1 6 1 7 1 8 1 9 2 1 2 2 2 3 2 4 2 6 2 7 2 8 2 9 3 1 3 2 33 3 4 111118888888188111188 99991111 211119991119911111199922199991111122 GGGGGGGG GGGGG GWWWWWWWWWWWWWWWWWWWWWWWWWWWWW CGWW II W ' GGWW 2 WGGWWWWCBCBICIC 'W' 2 GGGGWW 2 GWG CBCCBICICCCIC 'W' WW GGGWW 2WW''''''WWW2'2WWWW2WWWWWWWWWWWWWWWWWWWWWW2 22222222 G GGGGGGGGGGG GGWGGWG DISCHARGE POND CARLSBAD BLVD PROPERTY LINE EASEMENT H EASEMENT C ROW EAST RAMP WEST RAMP BRIDGE PROPOSED FLOATING BOOM PROPOSEDFINE SCREENING FACILITYINCLUDING SCREENINGEQUIPMENT AND DECK ACCESS PROPOSEDDEBRIS RETURN PROPOSED BOAT RAMP PROPOSED BOAT RAMP EXISTINGELECTRICALBUILDING PROPOSEDBULKHEAD FORTUNNEL ISOLATIONPROPOSEDMARINE RESEARCH PORTABLE CONTAINER PROPOSED DEBRIS BIN AREA EASEMENT J ACCESS ROAD PROPOSED STORM DRAIN EXTENSION STORM DRAIN INLET EASEMENT T NEW GRAVEL SURFACE EXISTING FOREBAY EXISTINGACCESS ROAD EASEMENT D EXISTINGACCESS ROAD A = 91,476 sf(2.1 ac) DMA 1 (EXCESS AREA) BMP/POC ID 2 WWWW WW GGGG 2222 WW G GGGG GGGGGG 2'W STORM DRAIN INLET A = 10,890 sf (0.25 ac) DMA 5 WW GGGGG 22 WWW G GGGGGGGG PROPOSED FEEDERCONNECTION A = 10,169 sf (0.23 ac) DMA 6A = 1,163 SF(0.027 ac) DMA 7 DMA 4A = 8,712 sf (0.2ac) DMA 2A = 16,117 sf (0.37 ac) 35,736 SQUARE FEET OF DMA 1 WILL BE USED FOR SWAPPING DMA 3A = 32,234 sf (0.74 ac)STORM DRAIN MANHOLE EXISTING CDP-IPS A = 13,661 sf (0.31 ac) EASEMENT C PROPOSED ELECTRICALBUILDING EXISTING BIORETENTION POND EASEDMA 8 BMP/POC ID 1 POC ID 4 POC ID 3 SDSDSDSDSD OF 299 B 2 ISSUE DESCRIPTION PROJECT MANAGER PROJECT NUMBER 0 1"2"FILENAME SCALE SHEET DATE C D A 1 345678 CARLSBAD DESALINATION PLANTPHASE 2 INTAKE MODIFICATIONSISSUED FOR CONSTRUCTION S. FRIEDMAN 10341720 DESIGNED BY CHECKED BY DRAWN BY J. MOYER R. STRATTON D. CELAYA DRAINAGE MANAGEMENTAREA (DMA) EXHIBIT 1" = 40'--- SCALE: 1"=40' 40 80 120 4 PLAN SCALE: 1" = 40' NOTES 1. HYDROLOGIC SOIL GROUP IS B 2. DEPTH TO GROUNDWATER BELOW GROUND LEVEL IS LESS THAN 5 FEET 3. SEE SSPCBMP EXHIBIT FOR LOCATION OF STRUCTURAL BMPS 4. TREATMENT OF IMPERVIOUS AND SEMI-PERVIOUS SURFACES OF APPLICABLE REQUIRED DMA'S WILL BE SWAPPED WITH DMA 1 (EXCESS AREA). 5. ALL DMA'S ARE "REQUIRED" UNLESS OTHERWISE NOTED AS "EXCESS". SUCH EXCESS AREAS ARE PROPOSED FOR SWAPPING. EXISTING IMPERVIOUS SURFACE (~ 147,565 SF [3.39 ac]) RECONSTRUCTED IMPERVIOUS SURFACE (~ 26,330 SF [0.61 ac]) NEW IMPERVIOUS SURFACE (~ 4,565 SF [0.11 ac]) DMA LIMITS EXISTING BIORETENTION AREA (~ 161 SF [0.0037 ac]) EXISTING LANDSCAPING (~ 27,307 SF [0.63 ac]) RECONSTRUCTED LANDSCAPING (~ 22,003 SF [0.51 ac]) NEW IMPERVIOUS SURFACE OVER LAGOON (~ 6,272 SF [0.15 ac]) NEW SEMI-PERVIOUS SURFACE (~ 10,868 SF [0.25 ac]) NEW PERVIOUS SURFACE OVER LAGOON (~ 6,707 SF [0.15 ac]) SUMMARY OF DMA INFORMATION NO. OF DMA'S TOTAL DMAAREA (AC)TOTAL IMPERVIOUSSURFACE (AC)%IMPERVIOUSNESS AREA WEIGHTEDRUNOFF COEFFICIENT TOTALDCV (CF)TOTAL AREATREATED (AC)NO. OF POCS 8 4.23 3.177 62.5 B 0.9 5897 3.67 4 TABULAR SUMMARY OF DMA'S DMA UNIQUE IDENTIFIER*AREA (AC)IMPERVIOUS SURFACE (AC), NEW, RECONSTRUCTED % IMPERVIOUSNESS HSG AREA WEIGHTED RUNOFF COEFFICIENT DCV (CF) DMA 1 2.10 2.10 100 B 0.9 3979 DMA 2 0.37 0.20 50 B 0.9 421 DMA 3 0.74 0.50 50 B 0.9 947 DMA 4 0.20 0.10 50 B 0.9 379 DMA 5 0.25 0.25 100 B 0.9 171 DMA 6 0.23 0 0 B 0.9 - DMA 7 0.027 0.027 100 B 0.9 - DMA 8 0.31 0 10 B 0.9 - WORKSHEET B-1 TREATED BY(BMP ID)POLLUTANT CONTROL TYPE DRAINS TO(POC ID) 1 PROPRIETARY BIOFILTRATION 1 2 LANDSCAPING 2 1 PROPRIETARY BIOFILTRATION 1 1 PROPRIETARY BIOFILTRATION 3 1 PROPRIETARY BIOFILTRATION NONE 1 PROPRIETARY BIOFILTRATION NONE 1 PROPRIETARY BIOFILTRATION NONE 1 PROPRIETARY BIOFILTRATION 4 LEGEND * THE PROPOSED PERVIOUS AND IMPERVIOUS SURFACES FOR ALL DMA'S WILL BE SWAPPED WITH DMA 1 (EXCESS AREA). PROPOSED PERVIOUS SURFACE AREA (SQUARE FEET) RECONSTRUCTED LANDSCAPE 22,003 NEW LANDSCAPING 0 TOTAL 22,164 PROPOSED IMPERVIOUS SURFACEFOR MITIGATION AREA (SQUARE FEET) RECONSTRUCTED IMPERVIOUSSURFACE 26,330 NEW IMPERVIOUS SURFACE 4,565 TOTAL 30,895 Figure 1 $SSHQGL['*HRWHFKQLFDO(QJLQHHU$QDO\VLV ' 6HSW Appendix D Geotechnical Engineer Analysis Analysis of Infiltration Restrictions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·RI&RQWDPLQDWHG6RLOV %03LVZLWKLQ·RI,QGXVWULDO$FWLYLWLHV/DFNLQJ6RXUFH&RQWURO %03LVZLWKLQ·RI:HOO*URXQGZDWHU%DVLQ %03LVZLWKLQ·RI6HSWLF7DQNV/HDFK)LHOGV %03LVZLWKLQ·RI6WUXFWXUHV7DQNV:DOOV %03LVZLWKLQ·RI6HZHU8WLOLWLHV %03LVZLWKLQ·RI*URXQGZDWHU7DEOH %03LVZLWKLQ+\GULF6RLOV %03LVZLWKLQ+LJKO\/LTXHILDEOH6RLOVDQGKDV&RQQHFWLYLW\WR6WUXFWXUHV %03LVZLWKLQ7LPHVWKH+HLJKWRI$GMDFHQW6WHHS6ORSHV &RXQW\6WDIIKDV$VVLJQHG´5HVWULFWHGµ,QILOWUDWLRQ&DWHJRU\ 2SWLRQDO &RQVLGHUDWLRQV %03LVZLWKLQ3UHGRPLQDQWO\7\SH'6RLO %03LVZLWKLQ·RI3URSHUW\/LQH %03LVZLWKLQ)LOO'HSWKVRI·([LVWLQJRU3URSRVHG %03LVZLWKLQ·RI8QGHUJURXQG8WLOLWLHV %03LVZLWKLQ·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igure 2 Attachment 1e Pollutant Control BMPs Design Worksheets / Calculations Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name 12345678 unitless 2 85th Percentile 24-hr Storm Depth 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 inches 3 Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 91,476 0 0 3,485 22,653 0 1,163 0 sq-ft 4 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30)0000011,996 0 0 sq-ft 5 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10)00000000 sq-ft 6 Natural Type A Soil Not Serving as Dispersion Area (C=0.10)00000000 sq-ft 7 Natural Type B Soil Not Serving as Dispersion Area (C=0.14) 0 0 0 5,227 3,776 0 0 0 sq-ft 8 Natural Type C Soil Not Serving as Dispersion Area (C=0.23)00000000 sq-ft 9 Natural Type D Soil Not Serving as Dispersion Area (C=0.30)00000000 sq-ft 10 Does Tributary Incorporate Dispersion, Tree Wells, and/or Rain Barrels? No Yes Yes No Yes No No Yes yes/no 11 Impervious Surfaces Directed to Dispersion Area per SD-B (Ci=0.90) 0 11,067 2,336 0 000 20,000 0 sq-ft 12 Semi-Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.30) 0 000000 000 sq-ft 13 Engineered Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.10) 0 000000 000 sq-ft 14 Natural Type A Soil Serving as Dispersion Area per SD-B (Ci=0.10) 0 000000 000 sq-ft 15 Natural Type B Soil Serving as Dispersion Area per SD-B (Ci=0.14) 0 5,000 2,336 0 11,327 0 0 32,166 0 sq-ft 16 Natural Type C Soil Serving as Dispersion Area per SD-B (Ci=0.23) 0 000000 000 sq-ft 17 Natural Type D Soil Serving as Dispersion Area per SD-B (Ci=0.30) 0 000000 000 sq-ft 18 Number of Tree Wells Proposed per SD-A 0 000000 000 # 19 Average Mature Tree Canopy Diameter 0 000000 000 ft 20 Number of Rain Barrels Proposed per SD-E 0 000000 000 # 21 Average Rain Barrel Size 0 000000 000 gal 22 Total Tributary Area 91,476 16,067 4,672 8,712 37,756 11,996 1,163 52,166 0 0 sq-ft 23 Initial Runoff Factor for Standard Drainage Areas 0.90 0.00 0.00 0.44 0.79 0.30 0.90 0.00 0.00 0.00 unitless 24 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 0.66 0.52 0.00 0.14 0.00 0.00 0.43 0.00 0.00 unitless 25 Initial Weighted Runoff Factor 0.90 0.66 0.52 0.44 0.59 0.30 0.90 0.43 0.00 0.00 unitless 26 Initial Design Capture Volume 3,979 513 117 185 1,077 174 51 1,084 0 0 cubic-feet 27 Total Impervious Area Dispersed to Pervious Surface 0 11,067 2,336 000020,000 0 0 sq-ft 28 Total Pervious Dispersion Area 0 5,000 2,336 0 11,327 0 0 32,166 0 0 sq-ft 29 Ratio of Dispersed Impervious Area to Pervious Dispersion Area n/a 2.20 1.00 n/a n/a n/a n/a 0.60 n/a n/a ratio 30 Adjustment Factor for Dispersed & Dispersion Areas 1.00 0.27 0.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 ratio 31 Runoff Factor After Dispersion Techniques 0.90 0.18 0.00 0.44 0.59 0.30 0.90 0.00 n/a n/a unitless 32 Design Capture Volume After Dispersion Techniques 3,979 140 0 185 1,077 174 51 0 0 0 cubic-feet 33 Total Tree Well Volume Reduction 0000000000cubic-feet 34 Total Rain Barrel Volume Reduction 0000000000cubic-feet 35 Final Adjusted Runoff Factor 0.90 0.18 0.00 0.44 0.59 0.30 0.90 0.00 0.00 0.00 unitless 36 Final Effective Tributary Area 82,328 2,892 0 3,833 22,276 3,599 1,047 0 0 0 sq-ft 37 Initial Design Capture Volume Retained by Site Design Elements 0 373 117 00001,084 0 0 cubic-feet 38 Final Design Capture Volume Tributary to BMP 3,979 140 0 185 1,077 174 51 0 0 0 cubic-feet False False Automated Worksheet B.1: Calculation of Design Capture Volume (V2.0) Dispersion Area, Tree Well & Rain Barrel Inputs (Optional) Standard Drainage Basin Inputs Results Tree & Barrel Adjustments Initial Runoff Factor Calculation Dispersion Area Adjustments No Warning Messages Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name 12345678--unitless 2 85th Percentile Rainfall Depth 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 - - inches 3 Predominant NRCS Soil Type Within BMP Location BBBBBBBBBBunitless 4 Is proposed BMP location Restricted or Unrestricted for Infiltration Activities? Restricted Restricted Restricted Restricted Restricted Restricted Restricted Restricted Restricted Restricted unitless 5 Nature of Restriction Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater unitless 6 Do Minimum Retention Requirements Apply to this Project? Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes yes/no 7 Are Habitable Structures Greater than 9 Stories Proposed? No No No No No No No No No No yes/no 8 Has Geotechnical Engineer Performed an Infiltration Analysis? No No No No No No No No No No yes/no 9 Design Infiltration Rate Recommended by Geotechnical Engineer 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 in/hr 10 Design Infiltration Rate Used To Determine Retention Requirements 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 in/hr 11 Percent of Average Annual Runoff that Must be Retained within DMA 4.5% 4.5% 4.5% 4.5% 4.5% 4.5% 4.5% 4.5% 1.5% 1.5% percentage 12 Fraction of DCV Requiring Retention 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.01 ratio 13 Required Retention Volume 80 3 0 4 22 31000cubic-feet False False Automated Worksheet B.2: Retention Requirements (V2.0) Advanced Analysis Basic Analysis Result No Warning Messages Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name 12345678--sq-ft 2 Design Infiltration Rate Recommended 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 - - in/hr 3 Design Capture Volume Tributary to BMP 3,979 140 0 185 1,077 174 51 0 - - cubic-feet 4 Is BMP Vegetated or Unvegetated? Vegetated Vegetated unitless 5 Is BMP Impermeably Lined or Unlined? Unlined unitless 6 Does BMP Have an Underdrain? No Underdrain unitless 7 Does BMP Utilize Standard or Specialized Media? Standard unitless 8 Provided Surface Area 500 sq-ft 9 Provided Surface Ponding Depth 6 inches 10 Provided Soil Media Thickness inches 11 Provided Gravel Thickness (Total Thickness)inches 12 Underdrain Offset inches 13 Diameter of Underdrain or Hydromod Orifice (Select Smallest)inches 14 Specialized Soil Media Filtration Rate in/hr 15 Specialized Soil Media Pore Space for Retention unitless 16 Specialized Soil Media Pore Space for Biofiltration unitless 17 Specialized Gravel Media Pore Space unitless 18 Volume Infiltrated Over 6 Hour Storm 0000000000cubic-feet 19 Ponding Pore Space Available for Retention 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 unitless 20 Soil Media Pore Space Available for Retention 0.05 0.25 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 unitless 21 Gravel Pore Space Available for Retention (Above Underdrain) 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 unitless 22 Gravel Pore Space Available for Retention (Below Underdrain) 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 unitless 23 Effective Retention Depth 0.00 6.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches 24 Fraction of DCV Retained (Independent of Drawdown Time) 0.00 1.79 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 25 Calculated Retention Storage Drawdown Time 0 >120 00000000hours 26 Efficacy of Retention Processes 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 27 Volume Retained by BMP (Considering Drawdown Time)0000000000cubic-feet 28 Design Capture Volume Remaining for Biofiltration 3,979 140 0 185 1,077 174 51 0 0 0 cubic-feet 29 Max Hydromod Flow Rate through Underdrain 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 cfs 30 Max Soil Filtration Rate Allowed by Underdrain Orifice 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 in/hr 31 Soil Media Filtration Rate per Specifications 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 in/hr 32 Soil Media Filtration Rate to be used for Sizing 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 in/hr 33 Depth Biofiltered Over 6 Hour Storm 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches 34 Ponding Pore Space Available for Biofiltration 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 35 Soil Media Pore Space Available for Biofiltration 0.20 0.00 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 unitless 36 Gravel Pore Space Available for Biofiltration (Above Underdrain) 0.40 0.00 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 unitless 37 Effective Depth of Biofiltration Storage 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches 38 Drawdown Time for Surface Ponding 0000000000hours 39 Drawdown Time for Effective Biofiltration Depth 0 #DIV/0!00000000hours 40 Total Depth Biofiltered 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches 41 Option 1 - Biofilter 1.50 DCV: Target Volume 5,969 210 0 278 1,616 261 77 0 0 0 cubic-feet 42 Option 1 - Provided Biofiltration Volume 0000000000cubic-feet 43 Option 2 - Store 0.75 DCV: Target Volume 2,984 105 0 139 808 131 38 0 0 0 cubic-feet 44 Option 2 - Provided Storage Volume 0000000000cubic-feet 45 Portion of Biofiltration Performance Standard Satisfied 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 46 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements?No Yes Yes No No No No Yes - - yes/no 47 Overall Portion of Performance Standard Satisfied (BMP Efficacy Factor) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 48 Deficit of Effectively Treated Stormwater -3,979 -140 n/a -185 -1,077 -174 -51 n/a n/a n/a cubic-feet Retention Calculations Automated Worksheet B.3: BMP Performance (V2.0) -Retention storage must drawdown in 120 hours or less to quantify retention benefits. False BMP Inputs Biofiltration Calculations -This BMP does not fully satisfy the performance standards for pollutant control for the drainage area. False False False Result -Minimum annual retention criteria are not satisfied for each individual drainage area. Implement additional site design elements, increase structural BMP retention capacity, or demonstrate that such requirements are satisfied at the project-level False Attention! Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B-40 Sept. 2021 Sizing for Proprietary Biofiltration BMPs Proprietary biofiltration treatment control BMPs shall be sized to filter or treat the maximum flow rate of runoff produced from a rainfall intensity of 0.2 inch of rainfall per hour, for each hour of every storm event. The required flow-thru treatment rate should be adjusted for the portion of the DCV already retained or biofiltered onsite as described in Worksheet B.6-1. The following hydrologic method must be used to calculate the flow rate to be filtered or treated: 𝑃=𝐴× 𝑖× 𝐴 Where: Q = Design flow rate in cubic feet per second C = Runoff factor, area-weighted estimate using Table B.1-1. i = Rainfall intensity of 0.2 in/hr. A = Tributary area (acres) which includes the total area draining to the BMP, including any offsite or onsite areas that comingle with project runoff and drain to the BMP. Refer to Section 3.3.3 for additional guidance. Street projects consult Section 1.4.3. Worksheet B.6-1: Flow-Thru Design Flows Flow-thru Design Flows Worksheet B.6-1 1 DCV DCV cubic-feet 2 DCV retained DCVretained cubic-feet 3 DCV biofiltered DCVbiofiltered cubic-feet 4 DCV requiring flow-thru (Line 1 – Line 2 – 0.67*Line 3) DCVflow-thru cubic-feet 5 Adjustment factor (Line 4 / Line 1)* AF= unitless 6 Design rainfall intensity i= 0.20 in/hr 7 Area tributary to BMP (s) A= acres 8 Area-weighted runoff factor (estimate using Appendix B.2) C= unitless 9 Calculate Flow Rate = AF x (C x i x A) Q= cfs Source: City of Carlsbad Engineering Standards, Volume 5; BMP Design Manual; effective February 16, 2016; revised September 1, 2021 𝑫𝑫𝑫𝑫𝑫𝑫 𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪𝑪 for Swapping (flow-based treatment only) Treatment via proposed MWS device (BMP 1) 𝐷𝐷𝐷𝐷𝐷𝐷 1 (𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑒𝑒𝑎𝑎𝑒𝑒𝑒𝑒) 𝑅𝑅𝑒𝑒𝑒𝑒𝑅𝑅𝑅𝑅𝑅𝑅 𝐹𝐹𝑒𝑒𝐹𝐹𝑒𝑒𝑅𝑅𝑎𝑎=0.90 𝑝𝑝𝑒𝑒𝑎𝑎 𝑒𝑒𝑒𝑒𝑡𝑡𝑒𝑒𝑒𝑒 𝐵𝐵.1 −1 𝐷𝐷𝐷𝐷𝐷𝐷=3,979 𝐹𝐹𝑅𝑅 𝐷𝐷=2.1 𝑒𝑒𝐹𝐹 (91,476 𝑠𝑠𝑅𝑅) 𝑈𝑈𝑒𝑒𝑒𝑒𝑒𝑒 𝐷𝐷𝐷𝐷𝐷𝐷=3,979 𝑐𝑐𝑐𝑐91,476 𝑠𝑠𝑐𝑐=0.0435 𝑐𝑐𝑐𝑐𝑠𝑠𝑐𝑐 (𝑒𝑒𝑒𝑒𝑒𝑒 𝑝𝑝𝑒𝑒𝑒𝑒𝑒𝑒𝑝𝑝 𝑒𝑒𝑎𝑎𝑒𝑒𝑒𝑒) 𝑇𝑇𝑎𝑎𝑒𝑒𝑒𝑒𝑒𝑒𝑇𝑇𝑒𝑒𝑒𝑒𝑒𝑒 𝑅𝑅𝑅𝑅 𝑅𝑅𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑎𝑎𝑒𝑒𝑝𝑝 𝐷𝐷𝑎𝑎𝑒𝑒𝑒𝑒𝑠𝑠 𝐷𝐷𝑝𝑝𝑝𝑝𝑎𝑎𝑅𝑅𝑒𝑒𝐹𝐹ℎ 𝑒𝑒𝑠𝑠 𝑒𝑒𝑅𝑅 𝑒𝑒𝑎𝑎𝑒𝑒𝑒𝑒𝑒𝑒 𝑒𝑒𝑇𝑇𝑝𝑝𝑒𝑒𝐹𝐹𝑒𝑒𝑒𝑒𝑝𝑝 𝑝𝑝𝑒𝑒𝑒𝑒𝑒𝑒𝑝𝑝 𝑒𝑒𝑎𝑎𝑒𝑒𝑒𝑒𝑠𝑠 𝑅𝑅𝑒𝑒𝐹𝐹𝑅𝑅𝑒𝑒𝑠𝑠𝑒𝑒𝑎𝑎𝑒𝑒𝐹𝐹𝑒𝑒𝑒𝑒𝑝𝑝 𝐼𝐼𝑇𝑇𝑝𝑝𝑒𝑒𝑎𝑎𝑒𝑒𝑒𝑒𝑅𝑅𝑒𝑒𝑠𝑠 𝑆𝑆𝑒𝑒𝑎𝑎𝑅𝑅𝑒𝑒𝐹𝐹𝑒𝑒 25,170 𝑠𝑠𝑅𝑅 (0.58 𝑒𝑒𝐹𝐹) 𝑁𝑁𝑒𝑒𝑁𝑁 𝐼𝐼𝑇𝑇𝑝𝑝𝑒𝑒𝑎𝑎𝑒𝑒𝑒𝑒𝑅𝑅𝑒𝑒𝑠𝑠 𝑆𝑆𝑒𝑒𝑎𝑎𝑅𝑅𝑒𝑒𝐹𝐹𝑒𝑒 4,565 𝑠𝑠𝑅𝑅 (0.11 𝑒𝑒𝐹𝐹) 𝑆𝑆𝑒𝑒𝑡𝑡𝑒𝑒𝑅𝑅𝑒𝑒𝑒𝑒𝑒𝑒 29,735 𝑠𝑠𝑅𝑅 (0.68 𝑒𝑒𝐹𝐹) 𝑅𝑅𝑒𝑒𝑒𝑒𝑅𝑅𝑅𝑅𝑅𝑅 𝐹𝐹𝑒𝑒𝐹𝐹𝑒𝑒𝑅𝑅𝑎𝑎=0.90 𝐹𝐹𝑅𝑅𝑎𝑎𝑒𝑒𝑡𝑡𝑒𝑒𝐹𝐹 𝐷𝐷𝑎𝑎𝑒𝑒𝑒𝑒 𝑒𝑒𝑠𝑠 𝑠𝑠𝑒𝑒𝑇𝑇𝑒𝑒−𝑝𝑝𝑒𝑒𝑎𝑎𝑒𝑒𝑒𝑒𝑅𝑅𝑒𝑒𝑠𝑠 𝐷𝐷=0.23 𝑒𝑒𝐹𝐹 (10,169 𝑠𝑠𝑅𝑅 ) 𝑅𝑅𝑒𝑒𝑒𝑒𝑅𝑅𝑅𝑅𝑅𝑅 𝐹𝐹𝑒𝑒𝐹𝐹𝑒𝑒𝑅𝑅𝑎𝑎=0.30 𝑅𝑅𝑒𝑒𝐹𝐹𝑅𝑅𝑒𝑒𝑠𝑠𝑒𝑒𝑎𝑎𝑒𝑒𝐹𝐹𝑒𝑒𝑒𝑒𝑝𝑝 𝐿𝐿𝑒𝑒𝑒𝑒𝑝𝑝𝑠𝑠𝐹𝐹𝑒𝑒𝑝𝑝𝑒𝑒 𝐷𝐷𝑎𝑎𝑒𝑒𝑒𝑒𝑠𝑠 𝐷𝐷=0.51 𝑒𝑒𝐹𝐹 (22,003 𝑠𝑠𝑅𝑅 ) 𝑅𝑅𝑒𝑒𝑒𝑒𝑅𝑅𝑅𝑅𝑅𝑅 𝐹𝐹𝑒𝑒𝐹𝐹𝑒𝑒𝑅𝑅𝑎𝑎=0.14 𝑇𝑇𝑅𝑅𝑒𝑒𝑒𝑒𝑒𝑒 𝐷𝐷𝑎𝑎𝑒𝑒𝑒𝑒=(29,735 𝑠𝑠𝑐𝑐 𝑥𝑥 0.90)+(10,169 𝑠𝑠𝑐𝑐 𝑥𝑥 0.30)+(22,003 𝑠𝑠𝑐𝑐 𝑥𝑥 0.14)0.90 𝑇𝑇𝑅𝑅𝑒𝑒𝑒𝑒𝑒𝑒 𝐷𝐷𝑎𝑎𝑒𝑒𝑒𝑒=29,735 𝑠𝑠𝑅𝑅+3,390 𝑠𝑠𝑅𝑅+3,423 𝑠𝑠𝑅𝑅=36,548 𝑠𝑠𝑅𝑅 (0.84 𝑒𝑒𝐹𝐹) Use I = 0.20 from Worksheet B.6-1 = 0.9 0.20 36,548 ! "#,$%& '(= 0.151 * +, ℎ . / , Use I = 0.427 for 1 hr, 1 yr event (see related trash capture backup calcs) = 0.9 0.427 36,548 ! "#,$%& '(= 0.322 * Hence, trash capture flow governs. +, 1 21.53 ∗ = 1.5 ∗ 0.322 * = 0.483 * 567 . * for proposed bioretention basin, BMP 2 (retention volume treatment) The BMP will treat a minimum equivalent area from tributary DMA 5 and 8 to equate to the same area for flow-based treatment (36,548 sf (0.84 acres)). DMA 5 Reconstructed/new impervious surface 7 = 0.57 * 224,800 3 8 * , = 0.90 Reconstructed landscaped areas 7 = 0.25 * 211,000 3 8 * , = 0.14 + 7, =29",:&& '( ; &.<&3=2 ,&&& '( ; &. "3 &.<& + 7, = 24,800 + 1,711 = 26,511 20.61 *3 Which is less than area for flow-based treatment. Hence, treat deficit area using DMA 8 existing impervious surface. Per Worksheet B.2, retention volume will be DMA 2 to 7: 33 cf ? = 9.5 9.5 0.37 2@ /3 = 33 * (ponded depth) Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B-10 Sept. 2021 Figure B.1-1: 85th Percentile 24-hour Isopluvial Map Project (0.58") County of San Diego Hydrology Manual Soil Hydrolo&ric Groups Leg,end Soil Groups � GroupA 1111 Groupe � ,Groupe � GtoupD � lJndelatfnil'led � Data UJiav able N t-+--+-+-+--+-��-'+-l'-!'-+4-++--1--++-+-l------++-+-+-+-+-++--1----1--+++++++++++++++-■ \V+ · �:;:fr8, �ff�,...,��r'1l/:3\11i� ?.f'.JMBW..!.Wlh�F CI-Mffll:lilh'TAJIU1Y� mhli:11 rat.ArA.Ark:1.\AR.PLfl2 � �-M R:Wa.ltua.wi n■.,-m£ia.--,.e1111•11frimNm hln.hi !"Jl.tnA..<il� Wml:Mlll'l5�...tti1urni ta llfl'UUIIICI .at-a. N liiirtlll'I a.D"ld!.� lt&pndd ,_.-cmai�DllWfthtwa.ma\�tM, p-rnbaDtgww'it�•nn-.Allli�NIIIJL 3 0 3 Miles Project (Soil B) PLAN VIEW VIEW A VIEW B CONTECH DIVERSION WEIR STRUCTURE MODEL: CONTECH-DS-4-4 SITE SPECIFIC DATA INTERNAL BYPASS DISCLOSURE: MWS-L-8-20-V WetlandMedia surface area = 2.9 ft x 74 ft = 214.6 ft2 gpm/ft² Solve for the pre treatment loading rate: Q = 0.5 cfs = 224.42 gpm Pretreatment surface area = 25.6 ft² per cartridge 224.42 gpm Solve for the required HGL: Q = 0.5 cfs = 224.42 gpm v = WetlandMedia loading rate = 1.0 gpm/ft² A = wetland perimeter x height = P x h Solve for height, h: Q = vA; Q = treatment flow rate; v = cd √(2gh); A= πD²/4 Treatment HGL, h = 2.9 ft Discharge coefficient, cd Coefficient of velocity, cv = 0.98 Coefficient of contraction for the orifice, cc = 0.62 0.61 so cd =2 x 0.61 = 1.22 Rewrite to solve for the diameter of the orifice: ft, cd=1.22, g = 32.17 ft/s² WetlandMedia Loading Rate = 224.42 gpm / 214.6 ft² = 1.0 FLOW-BASED SIZING Discharge Equation: Q = vA The diameter of the orifice needs to be 2.34 inches in order to produce a head of 2.9 ft in the MWS unit D = √ (π x 1.22 x √ (2 x 32.17 x 2.9 ) 4 x 0.5 = 0.2 ft = 2.34 inches 25.6 ft² x 5 cartridges 1.0 gpm/ft² x 74 ft 224.42 gpm gpm/ft² cd= cv x cc = This unit has 2 underdrain outlet, Q = 0.5 cfs, h = 2.9 Required treatment flow rate = 0.5 cfs = 224.42 gpm MWS-L-8-20-V wetland perimeter = P = 14.8 ft x 5 media cages = 74 ft WetlandMedia surface area = operating HGL x wetland perimeter MWS ORIFICE SIZING v pretreatment = Q/A = =1.8 2.9 ft=h = Q / (v *P) = MWS-L-8-20-V vault treatment capacity = 0.5 cfs = 224.42 gpm at 2.9 ft operating hydraulic grade line (HGL) The HGL within the MWS unit needs to be 2.9 ft in order to treat 0.5 cfs 𝐷= 4𝑄 𝜋𝐶ௗ 2𝑔ℎ; 𝐴 = 𝑄 𝑉𝑟𝑒𝑤𝑟𝑖𝑡𝑒 → 𝜋𝐷ଶ 4 = 𝑄 𝑐ௗ 2𝑔ℎ GG G 2'' W 2''W 2'' W 2''W 2''W 2''W 2''W SDM AC- 1 AC-2 G G GW GW GW ICB ICB ICBICBICB ICB ICB ICB ICB ICB AGUA HEDIONDA LAGOON DISCHARGE POND EXISTING CDP-IPS CDP CARLSBAD BLVDMMMMMMMMMMMMMMM MMM MMM MMMMMMMMMMMMPROPERTY LINE PROPERTY LINE EASEMENT H EXISTING ACCESS ROAD ACCESS ROAD EASEMENT C EXISTING ACCESS ROAD EASEMENT D EASEMENT C ROW EXISTING FOREBAY EASEMENT T EAST RAMP WEST RAMP ACCESS DECK EASEMENT S EASEMENT X EASEMENT S FLOATING BOOM FINE SCREENING FACILITY INCLUDING LOED, SCREENING EQUIPMENT, AND DECK ACCESS DEBRIS BIN AREA DEBRIS RETURN BOAT RAMP ELECTRICAL BUILDING EXISTING INTAKE ELECTRICAL BUILDING BULKHEAD FOR TUNNEL ISOLATION STORM DRAIN EXTENSION 88" FEEDER CONNECTION TEMPORARY MARINE RESEARCH PORTABLE CONTAINER (WILL BE REMOVED AFTER CONSTRUCTION) NORTH AND SOUTH TEMPORARY DRIVEWAY PER SEPARATE RIGHT-OF-WAY PERMIT BIOFILTRATION SYSTEM (MWS) INTAKE BULKHEAD VAULT AND FEEDER CONNECTION TIE-IN VAULT NPO G P NPO G P NP O G P NP O G P NP O G P NP O G P NPOGP N P O G P NP O G P NP O G P NP O G P NP O G P NP O G P NPO G P NP O G P NP O G P NP O G P NPOGP BIOFILTRATION BASIN 32 "DECLARATION OF RESPONSIBLE CHARGE" I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THE PORTION OF THE PROJECT SHOWN ON SHEET XX, THAT I HAVE EXERCISED RESPONSIBLE CHARGE OVER THE DESIGN OF THIS PORTION OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONS CODE, AND THAT THE DESIGN IS CONSISTENT WITH CURRENT STANDARDS. I UNDERSTAND THAT THE CHECK OF THE PROJECT DRAWINGS AND SPECIFICATIONS BY THE CITY OF CARLSBAD DOES NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITY FOR PROJECT DESIGN. FIRM: HDR ENGINEERING INC. ADDRESS: 3230 EL CAMINO REAL, STE 200 CITY, STATE: IRVINE, CA 92602 TELEPHONE: (714) 368-5636 BY: JANELLE M. MOYER R.C.E. NO.:C70050 REGISTRATION EXPIRATION DATE: 9-30-24 PLAN SCALE: 1" = 60' 0 SCALE: 1"=60' 60 120 180 3 ANY STRUCTURES WITHIN THIS AREA ARE NOT PART OF THIS PERMIT. ALL GRADING, HOWEVER, IS INCLUDED. GRADING SHOWN UNDER WATER IS NOT SUBJECT TO OBSERVATION BY CITY ENGINEERING INSPECTOR. DESIGN ENGINEER SHALL PROVIDE LETTER OF CERTIFICATION THAT ALL GRADING UNDER WATER HAS BEEN COMPLETED PER APPROVED PLAN OR IF REVISED, SPECIFY REVISION IN SAID LETTER AND UPDATE ON AS-BUILT PLANS. 3 TABLE OF EASEMENTS EASEMENT DOCUMENT GRANTOR GRANTEE C WATER PLANT INTAKE DISCHARGE EASEMENT AREA INCLUDING INTAKE PUMP STATION CONFIRMED BY SECOND AMENDED AND RESTATED GROUND LEASE AND EASEMENT AGREEMENT, APR 07, 2010 CABRILLO POWER I, LLC POSEIDON RESOURCES (CHANNELSLIDE) LP D CONNECTION EASEMENT AREA CONFIRMED BY SECOND AMENDED AND RESTATED GROUND LEASE AND EASEMENT AGREEMENT, APR 07, 2010 CABRILLO POWER I, LLC POSEIDON RESOURCES (CHANNELSLIDE) LP H SEAWATER INTAKE OUTFALL EASEMENT AREA CONFIRMED BY SECOND AMENDED AND RESTATED GROUND LEASE AND EASEMENT AGREEMENT, APR 07, 2010 CABRILLO POWER I, LLC POSEIDON RESOURCES (CHANNELSLIDE) LP S LAGOON INTAKE EASEMENT AREA CONFIRMED BY ELEVENTH AMENDMENT TO SECOND AMENDED AND RESTATED GROUND LEASE AND EASEMENT AGREEMENT, FEB 19, 2018 CABRILLO POWER I, LLC POSEIDON RESOURCES (CHANNELSLIDE) LP T TEMPORARY INTAKE, SCREENING, PUMPING, AND DISCHARGE EASEMENT AREA CONFIRMED BY ELEVENTH AMENDMENT TO SECOND AMENDED AND RESTATED GROUND LEASE AND EASEMENT AGREEMENT, FEB 19, 2018 CABRILLO POWER I, LLC POSEIDON RESOURCES (CHANNELSLIDE) LP X INTAKE MODIFICATION EASEMENT AREA CABRILLO POWER I LLC APPROVAL IN CONCEPT, LEASE AMENDMENT UNDER REVIEW WITH EXECUTION EXPECTED IN SEP 2022 CABRILLO POWER I, LLC POSEIDON RESOURCES (CHANNELSLIDE) LP 32 "DECLARATION OF RESPONSIBLE CHARGE" I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THE PORTION OF THE PROJECT SHOWN ON SHEET XX, THAT I HAVE EXERCISED RESPONSIBLE CHARGE OVER THE DESIGN OF THIS PORTION OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONS CODE, AND THAT THE DESIGN IS CONSISTENT WITH CURRENT STANDARDS. I UNDERSTAND THAT THE CHECK OF THE PROJECT DRAWINGS AND SPECIFICATIONS BY THE CITY OF CARLSBAD DOES NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITY FOR PROJECT DESIGN. FIRM: HDR ENGINEERING INC. ADDRESS: 3230 EL CAMINO REAL, STE 200 CITY, STATE: IRVINE, CA 92602 TELEPHONE: (714) 368-5636 BY: JANELLE M. MOYER R.C.E. NO.:C70050 REGISTRATION EXPIRATION DATE: 9-30-24 1 - MWS-L-8-20-12'-0"-V STORMWATER BIOFILTRATION SYSTEM SCALE: NTS 6.25 6.86 6.86 PE 6.25 14 PE 14 32 "DECLARATION OF RESPONSIBLE CHARGE" I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THE PORTION OF THE PROJECT SHOWN ON SHEET XX, THAT I HAVE EXERCISED RESPONSIBLE CHARGE OVER THE DESIGN OF THIS PORTION OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONS CODE, AND THAT THE DESIGN IS CONSISTENT WITH CURRENT STANDARDS. I UNDERSTAND THAT THE CHECK OF THE PROJECT DRAWINGS AND SPECIFICATIONS BY THE CITY OF CARLSBAD DOES NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITY FOR PROJECT DESIGN. FIRM: HDR ENGINEERING INC. ADDRESS: 3230 EL CAMINO REAL, STE 200 CITY, STATE: IRVINE, CA 92602 TELEPHONE: (714) 368-5636 BY: JANELLE M. MOYER R.C.E. NO.:C70050 REGISTRATION EXPIRATION DATE: 9-30-24 1 - DIVERSION WIER SCALE: NTS 6.90 7.00 PE 15 PE PE 6.90 6.90 15 2''W 2'' W 2''W 2'' W 2''W 2'' W 2''W 2''W 2''W 2''W 2''W 2''W 2''W EXISTING 10" STEEL WATER LINE, ABANDONED EXISTING 18" PVC STORM DRAIN EXISTING 6" PVC STORM DRAIN EXISTING 6" PVC STORM DRAIN 1 2 STA 2+09.44 HPI 30 DEG BEND EXISTING STORM DRAIN MANHOLE SEE PLAN ON SHEET 22 STA 2+52.19 STA 2+95.60 STA 3+06.70 1+00 2+00 6 STA 1+26.59 HPI 30 DEG BEND EXISTING 63" HDPE SDR 21 BRINE DISCHARGE PIPE 4 4' STA 2+73.89, 8.67' L 3 1 STA 2+95.60, 5.25' L 9 STA 2+52.19, 5.25' L9 7 7 10 11 12 0 10 20 30 0 10 20 30 1+00 1+50 2+00 2+50 3+00 EXISTING GRADE CONNECT TO EXISTING STRUCTURE STA 1+00, IE 7.30± SEE 04C04 STA 3+06.70 END PIPELINE ELECTROFUSION SADDLE CONNECTION INV 4.68±ST A 3 + 0 9 . 3 2 EX I S T I N G 6 3 " H D P E S D R 2 1 BR I N E D I S C H A R G E P I P E IE 2 . 4 5 EXISTING STORM DRAIN MANHOLE RIM ELEVATION 17.3± FILL MANHOLE STRUCTURE WITH LEAN CONCRETE TO ELEVATION 7.3 EX I S T I N G 1 8 " P V C S T O R M D R A I N IN V 2 8 . 4 0 ± EX I S T I N G 6 " P V C S T O R M D R A I N IN V 8 . 8 0 ± 2 STA 2+97.60, IE OUT 6.06 STA 2+54.19, 24" IE OUT 6.90 STA 2+93.60, 24" IE IN 6.16 STA 2+50.19, 24" IE IN 7.00 DI V E R S I O N S T R U C T U R E ST A 2 + 5 2 . 1 9 RI M E L E V 1 8 . 0 0 4 EX I S T G A S ST A 2 + 0 3 . 6 2 ± IE U N K N O W N EX I S T W A T E R ST A 2 + 1 3 . 2 4 ± IE U N K N O W N EX I S T W A T E R ST A 2 + 2 6 . 1 9 ± IE U N K N O W N EX I S T W A T E R ST A 2 + 7 5 . 0 7 IE U N K N O W N EX I S T E L E C ST A 2 + 1 2 . 6 8 ± IE U N K N O W N EX I S T E L E C A N D C O M M ST A 2 + 1 7 . 1 9 ± IE U N K N O W N EX I S T C O M M ST A 2 + 5 9 . 9 7 ± IE U N K N O W N 5 STA 1+26.59, HPI 30 DEG BEND IE 7.24± STA 2+09.44, HPI 30 DEG BEND IE 7.03± 5 5 5 ST O R M D R A I N CL E A N O U T ST A 2 + 9 5 . 6 0 RI M E L E V 1 8 . 0 0 9.1 LF 18" HDPE DR 17 @ S=15.09% 5 BIOFILTRATION SYSTEM IN BACKGROUND 8" IE OUT 6.255 6 150.19 LF 24" PE (ASTM F2306) @ S=0.20% HGL 8" IE OUT 6.90 FROM DIVERSION STRUCTURE 5 8" IE IN 6.16 FROM STORMWATER BIOFILLTRATION STRUCTURE 8" IE IN 6.86 39.40 LF 24" PE (ASTM F2306) @ S=1.88% 5 5 PERMANENT WATER QUALITY TREATMENT FACILITY KEEPING OUR WATERWAYS CLEAN MAINTAIN WITH CARE - NO MODIFICATIONS WITHOUT AGENCY APPROVAL 32 "DECLARATION OF RESPONSIBLE CHARGE" I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THE PORTION OF THE PROJECT SHOWN ON SHEET XX, THAT I HAVE EXERCISED RESPONSIBLE CHARGE OVER THE DESIGN OF THIS PORTION OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONS CODE, AND THAT THE DESIGN IS CONSISTENT WITH CURRENT STANDARDS. I UNDERSTAND THAT THE CHECK OF THE PROJECT DRAWINGS AND SPECIFICATIONS BY THE CITY OF CARLSBAD DOES NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITY FOR PROJECT DESIGN. FIRM: HDR ENGINEERING INC. ADDRESS: 3230 EL CAMINO REAL, STE 200 CITY, STATE: IRVINE, CA 92602 TELEPHONE: (714) 368-5636 BY: JANELLE M. MOYER R.C.E. NO.:C70050 REGISTRATION EXPIRATION DATE: 9-30-24 PLAN SCALE: 1"=10' PROFILE HORIZ SCALE: 1"=10' VERT SCALE: 1"=5' CONSTRUCTION NOTES X 1.INSTALL 24" PE (ASTM F2306). SEE GENERAL NOTE 2 AND 4. 2.INSTALL 18" X 63" ELECTROFUSION SADDLE. 3.INSTALL MWS-L-8-20-12'-0"-V CONTECH STORMWATER BIOFILTRATION SYSTEM PER DETAIL 1 ON SHEET 14. 4.INSTALL DIVERSION WEIR STRUCTURE PER DETAIL 1 ON SHEET 15. 5.CONNECTION TO STRUCTURE, SEE GENERAL NOTE 5. 6.INSTALL STORM DRAIN CLEAN - TYPE A PER THE CITY OF SAN DIEGO STANDARD DRAWING D-09. 7.INSTALL 8" HDPE DR 17. SEE GENERAL NOTE 2. 8.NOT USED 9.INSTALL 8" HDPE DR 17 90° BEND. SEE GENERAL NOTE 2. 10.INSTALL 18" HDPE DR 17. SEE GENERAL NOTE 2. 11.INSTALL HDPE PIPE TO MANHOLE CONNECTOR FOR 8" PIPE PENETRATION INTO STORM DRAIN CLEANOUT 12.BMP SIGNAGE INSTALLED PER DETAIL 1 ON THIS SHEET. SIGNANGE SHALL BE NO SMALLER THAN 18"X12", CONSTRUCTED OF DURABLE MATERIALS, PERMANENTLY MOUNTED AND IN VISIBLE LOCATION. GENERAL NOTES 1.PIPE TO BE INSTALLED PER ASTM D2321. 2.FOR PIPE TRENCH SECTION SEE DETAIL 1 ON SHEET 13. 3.PIPE ZONE SHALL BE BACKFILLED WITH CLSM. 4.PIPE JOINTS SHALL BE INTEGRAL BELL AND SPIGOT AND WATER TIGHT (WT). 5.CONNECTIONS TO STRUCTURES SHALL BE IN ACCORDANCE WITH ASTM F2510 / F2510M AND DETAIL 3 ON SHEET 22. 0 SCALE: 1"=10' 10 20 30 2121 BMP TYPE SIZE OWNERSHIP MWS 8' X 20'CABRILLO NOTE: POSTS SHALL BE HOT-ROLLED HIGH TENSILE RAIL STEEL, PERFORATED WITH 3/8" HOLES AT 1" CENTERS, FINISHED WITH GREEN BAKED ENAMEL. 1 - BMP SIGNAGE DETAIL SCALE: NTS STEEL POST FINISHED GRADE BMP SIGN 18 GAUGE STEEL BAKED ENAMEL 3'- 0 " 5' - 0 " M I N G G G G G G G G G G G G G G G G G G G G 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2''W 2'' W 2'' W 2'' W 2'' W 2'' W 2'' W 2'' W 2'' W 2'' W 2'' W 2'' W G G AC-1 AC-2 G G G G G G GW GW GW ICB ICB IC B ICB ICB IC B IC B IC B IC B IC B 18.44 TC 17.99 TC 18.24 TC 18.33 TC 18.45 TC 18.49 TC 18.29 TC 0. 0 5 % 0. 2 7 % 1. 0 6 % 0. 7 0 % NPO G P NP O G P NP O G P NPOGP NPOGP NP O G P NPOGPNPOGP NPOGP NP O G P NP O G P NPOGP NPOGPNPOGPNPOGP NP O G P NPOG P NPOGP NPOGP NPOGP 32 "DECLARATION OF RESPONSIBLE CHARGE" I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THE PORTION OF THE PROJECT SHOWN ON SHEET XX, THAT I HAVE EXERCISED RESPONSIBLE CHARGE OVER THE DESIGN OF THIS PORTION OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONS CODE, AND THAT THE DESIGN IS CONSISTENT WITH CURRENT STANDARDS. I UNDERSTAND THAT THE CHECK OF THE PROJECT DRAWINGS AND SPECIFICATIONS BY THE CITY OF CARLSBAD DOES NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITY FOR PROJECT DESIGN. FIRM: HDR ENGINEERING INC. ADDRESS: 3230 EL CAMINO REAL, STE 200 CITY, STATE: IRVINE, CA 92602 TELEPHONE: (714) 368-5636 BY: JANELLE M. MOYER R.C.E. NO.:C70050 REGISTRATION EXPIRATION DATE: 9-30-24 0 SCALE: 1"=10' 10 20 30 PLAN SCALE: 1" = 10' STORM DRAIN EXTENSION SEE SHEET 21 EXISTING ACCESS ROAD PROPOSED ELECTRICAL BUILDING EXISTING INTAKE ELECTRICAL BUILDING 1.REPLACE ASPHALT PAVING, 4" AC OVER 4" CLASS II BASE 2.INSTALL 0" CURB PER SDRSD G-01 3.INSTALL 6" VERTICAL CURB PER SDRSD G-01 4.INSTALL SECURITY FENCE PER SDRSD M-06. MATCH FENCE HEIGHT TO EXISTING 5.INSTALL CURB STOP PER DTL 7, SHEET 19 6.INSTALL LOCKABLE PEDESTRIAN GATE PER DTL 6, SHEET 19 7.INSTALL SIDEWALK PER SDRSD G-7. CONSTRUCTION NOTES X 2 EXISTING 2" PVC DRAIN LINE TO REMAIN LANDSCAPE REMOVED WILL BE REPLACED IN KIND, SIMILAR IN SIZE, QUANTITY AND TYPE 2 EXISTING CDP-IPS ASPHALT RESTORATION CONCRETE LANDSCAPING SURFACE FLOW DIRECTION LEGEND TYP EXISTING NRG SECURITY SHACK EDGE OF EXIST SIDEWALK EXISTING ELECTRICAL BOXES APPROX. LOCATION OF EXISTING ELECTRICAL BOXES REPLACE STRIPING IN KIND (TYP) 6 4 ASPHALT CONCRETE SAWCUT LINE MATCH EXISTING ELEVATIONS 1 5 2 REMOVE AND REPLACE VEHICULAR GATE EXISTING VAULTS REMOVE AND REPLACE EXISTING SECURITY FENCE PROTECT IN PLACE ELECTRICAL PULL BOX PROTECT IN PLACE EXISTING BIORETENTION BASIN PROTECT IN PLACE UNKNOWN UTILITY PROTECT IN PLACE UTILITY BOX PROTECT IN PLACE LIGHT POLE STRIPE ON VAULTS (TYP) PROVIDE BOTTOM CLEARANCE FOR 1" VAULT CURB EL: 17.91 EL: 17.83 EL: 17.83 MATCH EXISTING ELEVATION ALONG ACCESS ROAD MATCH EXISTING ELEVATION ALONG ACCESS ROAD MATCH EXISTING ELEVATION ALONG SIDEWALK STRIPE ON VAULTS (TYP) STRIPING 7 3 STORMWATER BIOFILTRATION SYSTEM (BMP1) 2424 ANY STRUCTURES WITHIN THIS AREA ARE NOT PART OF THIS PERMIT. ALL GRADING, HOWEVER, IS INCLUDED. GRADING SHOWN UNDER WATER IS NOT SUBJECT TO OBSERVATION BY CITY ENGINEERING INSPECTOR. DESIGN ENGINEER SHALL PROVIDE LETTER OF CERTIFICATION THAT ALL GRADING UNDER WATER HAS BEEN COMPLETED PER APPROVED PLAN OR IF REVISED, SPECIFY REVISION IN SAID LETTER AND UPDATE ON AS-BUILT PLANS. Attachment 1f Trash Capture BMP Design Calculations DMA BMP Description C factor Intensity (in/hr)1 Area (ac) Q [Trash capture flow] (cfs) Trash capture flows controls (Y/N?) 1 POC ID 1 Swapped area 0.9 0.427 0.75 0.29 Y 0.29 Total Notes: 1Per NOAA Point Precipitation Frequency Estimate; see related backup -Calcs per BMP Design Manual, Appendix J See related swapped area backup calcs from Attachment 1b and 1e Trash Capture 10/16/22, 1:12 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=33.1389&lon=-117.3370&data=depth&units=english&series=pds 1/4 NOAA Atlas 14, Volume 6, Version 2 Location name: Carlsbad, California, USA* Latitude: 33.1389°, Longitude: -117.337° Elevation: 2.91 ft*** source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Sarah Dietz, Sarah Heim, Lillian Hiner, Kazungu Maitaria, Deborah Martin, SandraPavlovic, Ishani Roy, Carl Trypaluk, Dale Unruh, Fenglin Yan, Michael Yekta, Tan Zhao, GeoffreyBonnin, Daniel Brewer, Li-Chuan Chen, Tye Parzybok, John Yarchoan NOAA, National Weather Service, Silver Spring, Maryland PF_tabular | PF_graphical | Maps_&_aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 0.128(0.108‑0.154)0.162(0.136‑0.195)0.209(0.175‑0.252)0.249(0.207‑0.303)0.307(0.246‑0.388)0.355(0.278‑0.458)0.406(0.310‑0.537)0.461(0.341‑0.629)0.541(0.383‑0.771)0.607(0.415‑0.898) 10-min 0.184(0.155‑0.220)0.232(0.195‑0.279)0.300(0.251‑0.361)0.357(0.297‑0.435)0.441(0.353‑0.555)0.509(0.398‑0.656)0.581(0.444‑0.770)0.661(0.489‑0.901)0.775(0.549‑1.11)0.871(0.595‑1.29) 15-min 0.222(0.187‑0.267)0.281(0.236‑0.338)0.362(0.304‑0.437)0.432(0.359‑0.526)0.533(0.427‑0.672)0.615(0.482‑0.793)0.703(0.537‑0.931)0.799(0.592‑1.09)0.938(0.664‑1.34)1.05(0.719‑1.56) 30-min 0.314(0.264‑0.377)0.397(0.334‑0.477)0.512(0.429‑0.618)0.611(0.508‑0.743)0.754(0.604‑0.950)0.870(0.682‑1.12)0.995(0.759‑1.32)1.13(0.837‑1.54)1.33(0.940‑1.89)1.49(1.02‑2.20) 60-min 0.427(0.359‑0.512)0.540(0.453‑0.648)0.696(0.583‑0.839)0.830(0.690‑1.01)1.02(0.820‑1.29)1.18(0.926‑1.52)1.35(1.03‑1.79)1.54(1.14‑2.09)1.80(1.28‑2.57)2.02(1.38‑2.99) 2-hr 0.579(0.487‑0.695)0.723(0.608‑0.869)0.921(0.772‑1.11)1.09(0.906‑1.33)1.33(1.07‑1.68)1.53(1.20‑1.97)1.74(1.33‑2.30)1.97(1.46‑2.69)2.30(1.63‑3.28)2.57(1.76‑3.80) 3-hr 0.684(0.575‑0.820)0.852(0.716‑1.02)1.08(0.907‑1.31)1.28(1.06‑1.55)1.56(1.25‑1.96)1.78(1.40‑2.30)2.02(1.54‑2.68)2.28(1.69‑3.11)2.65(1.88‑3.78)2.95(2.02‑4.37) 6-hr 0.890(0.749‑1.07)1.11(0.935‑1.34)1.41(1.18‑1.70)1.67(1.38‑2.03)2.02(1.62‑2.55)2.30(1.81‑2.97)2.60(1.98‑3.44)2.91(2.16‑3.97)3.36(2.38‑4.79)3.71(2.54‑5.49) 12-hr 1.13(0.953‑1.36)1.44(1.21‑1.73)1.84(1.54‑2.22)2.17(1.81‑2.64)2.63(2.11‑3.32)2.99(2.34‑3.85)3.36(2.56‑4.44)3.74(2.77‑5.10)4.26(3.02‑6.08)4.68(3.20‑6.92) 24-hr 1.39(1.22‑1.61)1.79(1.58‑2.08)2.32(2.04‑2.70)2.75(2.40‑3.22)3.34(2.82‑4.03)3.79(3.14‑4.66)4.24(3.43‑5.34)4.71(3.71‑6.09)5.35(4.05‑7.19)5.84(4.29‑8.12) 2-day 1.70(1.50‑1.96)2.21(1.95‑2.56)2.88(2.53‑3.34)3.43(2.99‑4.01)4.16(3.52‑5.03)4.73(3.92‑5.82)5.31(4.30‑6.69)5.90(4.65‑7.63)6.70(5.08‑9.02)7.32(5.38‑10.2) 3-day 1.90(1.68‑2.20)2.48(2.19‑2.88)3.25(2.86‑3.77)3.87(3.38‑4.53)4.72(3.99‑5.70)5.38(4.46‑6.62)6.05(4.90‑7.62)6.74(5.31‑8.72)7.67(5.82‑10.3)8.40(6.17‑11.7) 4-day 2.07(1.82‑2.39)2.71(2.39‑3.14)3.56(3.12‑4.13)4.25(3.71‑4.97)5.20(4.39‑6.27)5.93(4.91‑7.30)6.67(5.41‑8.41)7.45(5.87‑9.64)8.50(6.45‑11.4)9.32(6.84‑13.0) 7-day 2.40(2.12‑2.78)3.17(2.79‑3.67)4.19(3.69‑4.87)5.03(4.39‑5.89)6.19(5.23‑7.48)7.09(5.88‑8.73)8.02(6.49‑10.1)8.98(7.08‑11.6)10.3(7.81‑13.9)11.3(8.31‑15.8) 10-day 2.66(2.35‑3.08)3.53(3.11‑4.09)4.70(4.13‑5.46)5.67(4.94‑6.63)7.00(5.92‑8.45)8.04(6.66‑9.90)9.12(7.38‑11.5)10.2(8.08‑13.2)11.8(8.94‑15.9)13.0(9.55‑18.1) 20-day 3.23(2.85‑3.73)4.34(3.82‑5.02)5.83(5.13‑6.77)7.09(6.18‑8.29)8.84(7.47‑10.7)10.2(8.48‑12.6)11.7(9.46‑14.7)13.2(10.4‑17.1)15.3(11.6‑20.7)17.1(12.5‑23.7) 30-day 3.82(3.37‑4.42)5.16(4.55‑5.98)6.98(6.13‑8.11)8.52(7.43‑9.97)10.7(9.04‑12.9)12.4(10.3‑15.3)14.3(11.5‑18.0)16.2(12.8‑20.9)18.9(14.3‑25.5)21.1(15.5‑29.4) 45-day 4.51(3.98‑5.22)6.09(5.37‑7.05)8.26(7.26‑9.59)10.1(8.82‑11.8)12.8(10.8‑15.4)14.9(12.3‑18.3)17.2(13.9‑21.6)19.6(15.4‑25.3)23.0(17.5‑31.0)25.8(19.0‑35.9) 60-day 5.22(4.61‑6.04)7.01(6.18‑8.12)9.50(8.35‑11.0)11.6(10.2‑13.6)14.7(12.5‑17.8)17.3(14.3‑21.3)20.0(16.2‑25.1)22.9(18.0‑29.6)27.0(20.5‑36.4)30.5(22.4‑42.4) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for agiven duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are notchecked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical 10/16/22, 1:12 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=33.1389&lon=-117.3370&data=depth&units=english&series=pds 2/4 Back to Top Maps & aerials Small scale terrain 10/16/22, 1:12 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=33.1389&lon=-117.3370&data=depth&units=english&series=pds 3/4 Large scale terrain Large scale map Large scale aerial + – 3km 2mi + – 100km 60mi + – 100km 60mi 10/16/22, 1:12 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=33.1389&lon=-117.3370&data=depth&units=english&series=pds 4/4 Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?: HDSC.Questions@noaa.gov Disclaimer + – 100km 60mi Project 1.2" Project 1.8" Page 1 of 10 State Water Resources Control Board Certified Trash Full Capture Systems Available to the Public (Updated October 13, 2022) Trash Provisions To qualify as a trash full capture system (System) as described below and satisfy the requirements of the Trash Provisions,1 a System installed after December 2, 2015, must be certified, prior to installation, by the State Water Resources Control Board (State Water Board) Executive Director, or designee, that meets the full capture system definition. The Trash Provisions define a full capture system as a treatment control, or series of treatment controls, including but not limited to, a multi-benefit project or a low impact development control that traps all particles that are 5-millimeter or greater, and has a design treatment capacity that is either: 1. Of not less than the peak flow rate resulting from a one-year, one-hour storm event (design storm) in the subdrainage area, or 2. Appropriately sized and designed to carry at least the same flows as the corresponding storm drain. Consistent with these requirements, the Systems shall not bypass trash below the design storm under maximum operational loading conditions and shall not have a diversion structure present upstream such that a portion of the peak flow is not treated to trap all particles 5-millimeter or greater. Vector Control Accessibility According to the California Health and Safety Code,2 California landowners are legally responsible to abate (eliminate the source of) a public nuisance arising from their property, including mosquitoes. Mosquito vector control districts have substantial authority to access public and private property, inspect known or suspected sources of 1 Amendment to the Water Quality Control Plan for Ocean Waters of California to Control Trash and Part 1 Trash Provisions of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California adopted by the State Water Board. 2 Health & Safety Code sections 2001-2002, 2060-2067, 100170, and 131075. Certified Trash Full Capture Systems Available to the Public Page 2 of 10 mosquitoes, abate mosquito sources, and charge the landowner for work performed and/or charge fees if a landowner is unwilling or unable to address a mosquito source arising from their property. If not designed properly, a System may impede the mosquito vector control district’s ability to (1) visually inspect the System and/or storm vault for mosquito breeding, and (2) apply the appropriate chemical treatment. Moreover, some Systems may create a habitat for mosquitoes. All the Systems in the tables below have been reviewed and approved by the Mosquito Vector Control Association of California for vector control accessibility. However, prior to installation of any Systems, the local mosquito vector control district should be contacted to ensure the installation conforms to the local district’s visual inspection, treatment, and vector breeding minimizing guidelines. The Mosquito Vector Control Association of California may also be contacted via email at Trashtreatment@mvcac.org. Certified Trash Full Capture System Tables The Systems included in the tables below are: 1) new Systems certified by the State Water Board Executive Director after adoption of the Trash Provisions, and 2) legacy Systems that were certified pursuant to the Trash Provisions include those full capture systems that were listed in Appendix I of the Bay Area-wide Trash Capture Demonstration Project, Final Project Report (May 8, 2014). All Systems remain certified unless and until they are decertified by the State Water Board’s Executive Director or designee. Legacy Systems’ descriptions are included in “fact sheets” that have been updated to address the application requirements for new Systems. The tables do not include the Department of Transportation’s Systems as its Systems are not available to the public. Multi-benefit trash treatment systems are listed separately on the State Water Board’s Trash Implementation webpage at: https://www.waterboards.ca.gov/water_issues/programs/stormwater/trash_implementati on.html. Systems are either identified by their application number or, for legacy Systems, by a fact sheet alpha numeric designation. Please note: Only Systems originally manufactured or distributed by the listed applicants are certified full capture systems. The alphabetical tables of System applicants are divided into two categories: ·Catch Basin Inserts and Other Insert Systems. These Systems typically are inserted into existing stormwater infrastructure; and Certified Trash Full Capture Systems Available to the Public Page 3 of 10 ·High Flow Capacity Trash Full Capture Systems. These Systems are generally self-contained units that typically are not inserted into existing stormwater infrastructure and that are designed to treat trash from large drainage areas. How to Access Certified System Applications and Legacy System Fact Sheets Other than those applications pertaining to the Department of Transportation’s certified Systems, all certified System applications and legacy System fact sheets may be obtained from the California Stormwater Quality Association’s trash webpage at: https://www.casqa.org/resources/trash/certified-full-capture-system-trash-treatment- control-devices. To obtain the Department of Transportation’s certified applications, please contact Leo Cosentini (contact information below). All questions concerning the Trash Provisions and the tables below should be directed to Leo Cosentini by email at Leo.Cosentini@waterboards.ca.gov or by phone at (916) 341-5524. Certified Trash Full Capture Systems Available to the Public Page 4 of 10 TABLE 1. Catch Basin Inserts and Other Insert Systems Applicant/Owner Full Capture System Name Date of Application Certification and Update (if applicable), or Fact Sheet Update Date of Vector Control Accessibility Approval AbTech Industries, Inc.Ultra Urban Filter Curb Opening and Drop-In Application 25 06/30/20 04/8/20 Advanced Drainage Systems, Inc. FLEXSTORM PURE Full Trash Capture Inserts Application 3 03/15/18 Updated 04/21/21 03/30/21 Advanced Drainage Systems, Inc. FLEXSTORM Connector Pipe Screen Fact Sheet ADS-1 Updated 06/08/21 03/30/21 Bio Clean® Environmental Services, Inc. Curb Inlet and Grate Inlet Filters Application 4 03/15/18 Updated 10/21/21 10/20/21 Bio Clean® Environmental Services, Inc. Modular Connector Pipe Trash Screen Fact Sheet BC-3 Updated 04/30/20 03/10/20 BrightWater™Connector Pipe Screen Application 29 03/15/18 Updated 12/29/20 11/19/20 BrightWater™Curb Inlet Filter Application 26 06/30/20 04/17/20 Certified Trash Full Capture Systems Available to the Public Page 5 of 10 Applicant/Owner Full Capture System Name Date of Application Certification and Update (if applicable), or Fact Sheet Update Date of Vector Control Accessibility Approval Ecology Control Industries Debris Dam - Catch Basin Insert for Curb Inlet Design Fact Sheet ECI-1 12/02/15 Updated 06/17/20 04/29/20 Enviropod® International: A Stormwater 360 Group Company Enviropod® LittaTrap™ Full Capture Application 27 10/14/20 07/20/20 Fabco Industries, Inc.Fabco Connector Pipe Screen Application 36 07/06/22 06/16/22 Fabco Industries, Inc.Fabco ScreenBox Application 37 10/13/22 10/05/22 Fabco Industries, Inc.Fabco StormBasin Application 38 10/13/22 10/05/22 Fabco Industries, Inc.Fabco StormSack Application 39 10/13/22 10/05/22 Filtrexx® Sustainable Technologies StormExx® Clean Application 16 08/10/18 Updated 11/25/19 12/06/19 Certified Trash Full Capture Systems Available to the Public Page 6 of 10 Applicant/Owner Full Capture System Name Date of Application Certification and Update (if applicable), or Fact Sheet Update Date of Vector Control Accessibility Approval Frog Creek Partners, LLC Gutter Bin® Channel Filtration System and Mundus Bag® Water Filter Application 22 06/26/19 04/19/19 Frog Creek Partners, LLC Gutter Bin® Eco Curb Inlet Filter and Mundus Bag® Water Filter Application 23 02/18/19 10/14/19 Frog Creek Partners, LLC Gutter Bin® Eco Drop Inlet Filter and Mundus Bag® Water Filter Application 24 02/18/20 12/06/19 G2 Construction, Inc.G2 CPS-Mod™ and Removable CPS- Mod™ Screen Application 18 06/26/19 03/15/19 G2 Construction, Inc.G2 Grated Inlet Trash Screen Application 19 06/26/19 04/10/19 Inventive Resources, Inc.Water Decontaminator Application 2 03/15/18 Updated 02/05/21 04/20/20 Oldcastle Infrastructure FloGard® + Plus® Catchbasin Trash Screen Insert, Combination Inlet Style Drop in Basket Fact Sheet OI-1 12/02/15 Updated 06/09/21 06/09/21 Oldcastle Infrastructure FloGard® Catchbasin Trash Screen Insert, Flat Grated Inlet Style Drop in Basket Fact Sheet OI-2 12/02/15 Updated 06/09/21 06/09/21 Certified Trash Full Capture Systems Available to the Public Page 7 of 10 Applicant/Owner Full Capture System Name Date of Application Certification and Update (if applicable), or Fact Sheet Update Date of Vector Control Accessibility Approval Oldcastle Infrastructure FloGard® Catchbasin Outlet Trash Screen Insert Connector Pipe Screen Fact Sheet OI-3 Updated 01/29/19 12/06/19 Revel Environmental Manufacturing, Inc. Triton™ Bioflex Inlet Trash Guard Catchbasin Polyester Fiber Mesh Trash Filter Insert Fact Sheet REM-1 12/02/15 Updated 09/10/21 09/07/21 Revel Environmental Manufacturing, Inc.Triton™ Crescent Pipe Screen Application 12 07/10/18 03/15/19 Revel Environmental Manufacturing, Inc.Triton™ Perf-Full Trash Capture Insert Application 13 07/10/18 Updated 12/21/21 12/20/21 Safe Drain Stormwater Holdings, Inc.Storm Vector Guard Application 30 02/11/21 12/17/20 Stormtek Stormtek ST3 & STEG Catchbasin Connector Pipe Fact Sheet AS-1, A1S-2 12/02/15 Updated 08/12/21 08/04/21 United Stormwater, Inc.Connector Pipe Trash Screen Fact Sheet USW-1 12/02/15 Updated 01/29/22 01/26/22 Certified Trash Full Capture Systems Available to the Public Page 8 of 10 TABLE 2. High Flow Capacity Trash Full Capture Systems Applicant/Owner Full Capture System Name Date of Application Certification and Update (if applicable), or Fact Sheet Update Date of Vector Control Accessibility Approval Advanced Drainage Systems, Inc.Barracuda Hydrodynamic Separator Application 21 06/26/19 Updated 05/21/21 03/15/19 AquaShield, Inc.Aqua-Swirl® Stormwater Treatment System Application 1 08/04/17 Updated 11/06/20 12/03/20 Bio Clean® Environmental Services, Inc.Debris Separating Baffle Box Application 6 03/15/18 07/28/20 Bio Clean® Environmental Services, Inc.Bio Clean® Deflective Screening Device Application 20 06/26/19 07/28/20 Bio Clean® Environmental Services, Inc.Modular Wetland System® Application 15 07/10/18 03/15/19 Coanda Inc.Coanda Trash Screen and Debris Fence Fact Sheet COA-1 12/02/15 Updated 09/10/21 09/07/21 Certified Trash Full Capture Systems Available to the Public Page 9 of 10 Applicant/Owner Full Capture System Name Date of Application Certification and Update (if applicable), or Fact Sheet Update Date of Vector Control Accessibility Approval Contech Engineered Solutions Continuous Deflective Separator Hydrodynamic Separator Fact Sheet CCP-1HF 12/02/15 Updated 05/27/21 04/29/21 Jensen® Stormwater Systems Jensen® Deflective Separators Application 5 03/15/18 12/06/19 Hydro International®Downstream Defender® (In-Line and Off- Line Configurations) Application 14 07/10/18 03/16/20 Hydro International®First Defense® High-Capacity Full Trash Capture Device Application 28 10/30/20 08/20/20 Hydro International®Hydro Up-Flo Filter®Application 11 07/18/18 03/16/20 Hydro International®Hydro DryScreen® Application 10 07/10/18 Updated 05/05/21 04/29/21 Certified Trash Full Capture Systems Available to the Public Page 10 of 10 Applicant/Owner Full Capture System Name Date of Application Certification and Update (if applicable), or Fact Sheet Update Date of Vector Control Accessibility Approval Oldcastle Infrastructure FloGard® NetTech Fact Sheet OI-11HF 12/02/15 Updated 02/08/20 12/03/20 Oldcastle Infrastructure Nutrient Separating Baffle Box® Application 17 10/12/18 Updated 07/21/20 07/20/20 Roscoe Moss Company Storm Flo® Trash Screen – Linear Radial Gross Solids Removal Device Fact Sheet RMC-1HF 12/02/15 Updated 03/30/21 03/11/21 StormTrap®, LLC SiteSaver® Application 9 03/15/18 Updated 02/23/21 03/18/21 StormTrap®, LLC TrashTrap® Net and Fixed Basket In-Line Stormwater Treatment System Application 34 06/21/22 05/03/22 StormTrap®, LLC TrashTrap® Net and Fixed Basket End- of-Pipe Stormwater Treatment System Application 35 07/06/22 06/01/22 Decembr 08, 2023 Attachment 2: Backup for PDP Hydromodification Control Measures The project is exempt from hydromodification management requirements (see above Hydromodification Management Requirements section for more information). Attachment Sequence Contents Checklist Attachment 2a Hydromodification Management Exhibit (Required) □ Included See Hydromodification Management Exhibit Checklist on the back of this Attachment cover sheet. Attachment 2b Management of Critical Coarse Sediment Yield Areas (WMAA Exhibit is required; additional analyses are optional.) See Section 6.2 of the BMP Design Manual. □ Exhibit showing project drainage boundaries marked on WMAA Critical Coarse Sediment Yield Area Map (Required) □ Optional analyses for Critical Coarse Sediment Yield Area Determination □ Appendix H.6.1 Verification of Geomorphic Landscape Units Onsite □ Appendix H.7 Downstream Systems Sensitivity to Coarse Sediment Attachment 2c Geomorphic Assessment of Receiving Channels (Optional) See Section 6.3.4 of the BMP Design Manual. □ Not performed □ Included Attachment 2d Flow Control Facility Design and Structural BMP Drawdown Calculations (Required) See Chapter 6 and Appendix G of the BMP Design Manual. □ Included Decembr 08, 2023 Attachment 3: Structural BMP Maintenance Information Final Design level submittal: Attachment 3 must identify: □ Specific maintenance indicators and actions for proposed structural BMP(s). This shall be based on Section 7.7 of the BMP Design Manual and enhanced to reflect actual proposed components of the structural BMP(s) □ How to access the structural BMP(s) to inspect and perform maintenance □ Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow the inspector to view necessary components of the structural BMP and compare to maintenance thresholds) □ Manufacturer and part number for proprietary parts of structural BMP(s) when applicable □ Maintenance thresholds for BMPs subject to siltation or heavy trash (e.g., silt level posts or other markings shall be included in all BMP components that will trap and store sediment, trash, and/or debris, so that the inspector may determine how full the BMP is, and the maintenance personnel may determine where the bottom of the BMP is located. If required, posts or other markings shall be indicated and described on structural BMP plans.) □ Recommended equipment to perform maintenance □ When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management STANDARD DETAIL STORMWATER BIOFILTRATION SYSTEM MWS-L-8-20-11'-8"-V FOR PATENT INFORMATION, GO TO www.ContechES.com/IP SITE SPECIFIC DATA PLAN VIEW ELEVATION VIEW RIGHT END VIEW LEFT END VIEW GENERAL NOTES INSTALLATION NOTES ENGINEERED SOLUTIONS Modular Wetlands® Linear Stormwater Biofiltration Your Contech Team Contech is the leader in stormwater solutions, helping engineers, contractors and owners with infrastructure and land development projects throughout North America. With our responsive team of stormwater experts, local regulatory expertise and flexible solutions, Contech is the trusted partner you can count on for stormwater management solutions. The experts you need to solve your stormwater challenges STORMWATER CONSULTANT It’s my job to recommend the best solution to meet permitting requirements. STORMWATER DESIGN ENGINEER I work with consultants to design the best approved solution to meet your project’s needs. REGULATORY MANAGER I understand the local stormwater regulations and what solutions will be approved. SALES ENGINEER I make sure our solutions meet the needs of the contractor during construction. Contech is your partner in stormwater management solutions Your Contech Team Contech is your partner in stormwater management solutions The Modular Wetlands® Linear is the only biofiltration system to utilize patented horizontal flow, allowing for a small footprint, high treatment capacity, and design versatility. It is also the only biofiltration system that can be routinely installed downstream of storage for additional volume control and treatment. With numerous regulatory approvals, the system’s aesthetic appeal and superior pollutant removal make it the ideal solution for a wide range of stormwater applications, including urban development projects, commercial parking lots, residential streets, mixed-use developments, streetscapes, and more. As cities grow, there is less space for natural solutions to treat stormwater. Contech understands this and is committed to providing compact, Low Impact Development (LID) solutions like the Modular Wetlands Linear to protect our nation’s waterways. Restoring Nature’s Presence in Urban Areas – Modular Wetlands® Linear ENGINEERED SOLUTIONS Using horizontal flow to improve performance 1. PRETREATMENT | Stormwater enters the pretreatment chamber where total suspended solids settle, and trash and debris are contained within the chamber. Stormwater then travels through the pretreatment filter boxes that provide additional treatment. 2. BIOFILTRATION | As water enters the biofiltration chamber, it fills the void space in the chamber’s perimeter. Horizontal forces push the water inward through the biofiltration media, where nutrients and metals are captured. The water then enters the drain pipe to be discharged. 3. DISCHARGE | The specially designed vertical drain pipe and orifice control plate control the flow of water through the media to a level lower than the media’s capacity, ensuring media effectiveness. The water then enters the horizontal drain pipe to be discharged. 4. BYPASS | During peak flows, an internal weir in the side-by-side configuration allows high flows to bypass treatment, eliminating flooding and the need for a separate bypass structure. Bypass is not provided in the end-to end configuration. How the Modular Wetlands® Linear Works 1 2 3 4 21 1 3 4 End View VEGETATION MANHOLE 8’-0”6”6” 4’ - 8 ” 8¹/2” 8” 3’ - 3 ¹/2” C/L 9’-0” CURB OPENING PLANTESTABLISHMENTMEDIA Using horizontal flow to improve performance FEATURE BENEFITS Pretreatment chamber Enhanced pollutant removal, faster maintenance Horizontal flow biofiltration Greater filter surface area Performance verified by both the WA DOE and NJ DEP Superior pollutant capture with confidence Built-in high flow bypass Eliminates flooding and the need for a separate bypass structure Available in multiple configurations and sizes Flexibility to meet site-specific needs Modular Wetlands Linear is approved through numerous local, state and federal programs, including but not limited to: Washington State Department of Ecology TAPE California Water Resources Control Board, Full Capture Certification Virginia Department of Environmental Quality (VA DEQ) New Jersey Department of Environmental Protection (NJDEP) Maryland Department of the Environment - Environmental Site Design (ESD) Rhode Island Department of Environmental Management BMP Texas Commission on Environmental Quality (TCEQ) Atlanta Regional Commission Certification Modular Wetlands® Linear Features and Benefits Select Modular Wetlands® Linear Approvals The Modular Wetlands system offers many different configurations. ENGINEERED SOLUTIONS VEGETATION MANHOLE 8’-0”6”6” 4’ - 8 ” 8¹/2” 8” 3’ - 3 ¹/2” C/L 9’-0” CURB OPENING PLANTESTABLISHMENTMEDIA Modular Wetlands® Linear Maintenance The Modular Wetlands® Linear is a self-contained treatment train. Maintenance requirements for the unit consist of five simple steps that can be completed using a vacuum truck. The system can also be cleaned by hand. Remove trash from the screening device Remove sediment from the separation chamber Periodically replace the pretreatment cartridge filter media Replace the drain down filter media Trim vegetation Most Modular Wetland Linear systems can be cleaned in about thirty minutes. Modular Wetlands® Performance The Modular Wetlands® Linear continues to outperform other treatment methods with superior pollutant removal for TSS, heavy metals, nutrients, and hydrocarbons. The Modular Wetlands® Linear is field-tested on numerous sites across the country and is proven to effectively remove pollutants through a combination of physical, chemical, and biological filtration processes. Multiple configurations allow for easy site integration POLLUTANT OF CONCERN MEDIAN REMOVAL EFFICIENCY MEDIAN EFFLUENT CONCENTRATION (MG/L) Total Suspended Solids (TSS)89%12 Total Phosphorus - TAPE (TP)61%0.041 Nitrogen (TN)23%1 Total Copper (TCu)50%0.006 Total Dissolved Copper 37%0.006 Total Zinc (TZn)66%0.019 Dissolved Zinc 60%0.0148 Motor Oil 79%0.8 Sources: TAPE Field Study - 2012 TAPE Field Study - 2013 Note: Some jurisdictions recognize higher removal rates. Contact your Contech Stormwater Consultant for performance expectations. VEGETATION MANHOLE 8’-0”6”6” 4’ - 8 ” 8¹/2” 8” 3’ - 3 ¹/2” C/L 9’-0” CURB OPENING PLANTESTABLISHMENTMEDIA VEGETATIONMANHOLE 8’-0”6”6” 4’ - 8 ” 8¹/2” 8” 3’ - 3 ¹/2” C/L 9’-0” CURB OPENING PLANTESTABLISHMENTMEDIA Modular Wetlands® Linear Configurations Multiple system configurations integrate with site hydraulic design and layout ... The Modular Wetlands Linear is offered in multiple configurations to meet site specific needs. This highly versatile system has available “pipe-in” options on most models, along with built-in curb or grated inlets for simple integration into your storm drain design. Curb Inlet The Curb Inlet configuration accepts sheet flow through a curb opening and is commonly used along roadways and parking lots. It can be used in sump or flow-by conditions. Vault The Vault configuration can be used in end-of-the-line installations. Another benefit of the “pipe-in” design is the ability to install the system downstream of underground detention systems to meet water quality volume requirements, or for traffic-rated designs (no plants). Downspout The Downspout configuration is designed to accept a vertical downspout pipe from rooftop and podium areas. Some models have the option of utilizing an internal bypass, simplifying the overall design. The system can be installed as a raised planter, and the exterior can be stuccoed or covered with other finishes to match the look of adjacent buildings. Multiple configurations allow for easy site integration ENGINEERED SOLUTIONS © 2022 Contech Engineered Solutions LLC, a QUIKRETE Company All Rights Reserved. Printed in the USA. A partner you can rely on Few companies offer the wide range of high- quality stormwater resources you can find with us — state-of-the-art products, decades of expertise, and all the maintenance support you need to operate your system cost-effectively. Get social with us: 800-338-1122 | www.ContechES.com NOTHING IN THIS CATALOG SHOULD BE CONSTRUED AS A WARRANTY. APPLICATIONS SUGGESTED HEREIN ARE DESCRIBED ONLY TO HELP READERS MAKE THEIR OWN EVALUATIONS AND DECISIONS, AND ARE NEITHER GUARANTEES NOR WARRANTIES OF SUITABILITY FOR ANY APPLICATION. CONTECH MAKES NO WARRANTY WHATSOEVER, EXPRESS OR IMPLIED, RELATED TO THE APPLICATIONS, MATERIALS, COATINGS, OR PRODUCTS DISCUSSED HEREIN. ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR PURPOSE ARE DISCLAIMED BY CONTECH. SEE CONTECH’S CONDITIONS OF SALE (AVAILABLE AT WWW.CONTECHES.COM/COS) FOR MORE INFORMATION. ENGINEERED SOLUTIONS THE CONTECH WAY Contech® Engineered Solutions provides innovative, cost-effective site solutions to engineers, contractors, and developers on projects across North America. Our portfolio includes bridges, drainage, erosion control, retaining wall, sanitary sewer and stormwater management products. TAKE THE NEXT STEP For more information: www.ContechES.com STORMWATER SOLUTIONS PIPE SOLUTIONS STRUCTURES SOLUTIONS Structural BMP Maintenance Information Refer to the Contech Modular Wetlands Linear Operation & Maintenance Manual (Modular Wetlands Maintenance Guide), dated 1/2023, for additional information. Specific Maintenance Indicators and Actions Indicators include, but are not limited to, missing or damaged internal components, obstructions, excessive accumulation of floatables or sediment. Take appropriate actions to correct such situations. See Maintenance Indicators Section in Manual for more information. Access BMP for Inspection and Maintenance Refer to Inspection Summary Section for information on required equipment for inspection and maintenance. Inspection Facilitation Features Refer to Inspection Summary Section for information on required equipment for inspection and maintenance. Manufacture and Part Numbers To be provided by Contech. Maintenance Thresholds for BMPs Subject to Siltation or Heavy Trash Use recommended equipment for siltation or heavy trash. Regular maintenance should reduce risk of these incidents. Recommended Equipment to Perform Maintenance Refer to Inspection Summary Section for information on required equipment for inspection and maintenance. Special Training or Certification Requirements Special training should not be required for maintenance. However, entering a confined space requires appropriate safety and certification. ENGINEERED SOLUTIONS Modular Wetlands® Linear Operation & Maintenance Manual 2 MODULAR WETLANDS® LINEAR OPERATION & MAINTENANCE MANUAL TABLE OF CONTENTS Overview ........................................................................................................3 Inspection Summary .......................................................................................4 Inspection Process ..........................................................................................5 Maintenance Indicators ..................................................................................6 Inspection Process ..........................................................................................7 Maintenance Summary ..................................................................................8 Pretreatment Chamber ................................................................9 Prefilter Cartridge ......................................................................10 Biofiltration Chamber ................................................................11 Discharge Chamber ...................................................................12 Inspection Report .........................................................................................13 Cleaning and Maintenance Report ................................................................14 3 OVERVIEW The Modular Wetlands® Linear Biofilter is designed to remove high levels of trash, debris, sediments, nutrients, metals, and hydrocarbons. Its simple design allows for quick and easy installation. The system is housed in a standard precast structure and can be installed at various depths to meet site-specific conditions. INTRODUCTION This is the Modular Wetlands Linear Biofilter operation and maintenance manual. Before starting, read the instructions and equipment lists closely. It is important to follow all necessary safety procedures associated with state and local regulations. Some steps required confined space entry. Please contact Contech for more information on pre-authorized third party contractors who can provide installation services in your area. For a list of service providers in your area please visit: www.conteches.com/maintenance. Pretreatment Chamber Biofiltration Chamber Discharger Chamber Prefilter Box Biofiltration Media Flow Control Riser Vertical Underdrain Outflow Inflow 4 INSTRUCTIONS INSPECTION SUMMARY Stormwater regulations require BMPs be inspected and maintained to ensure they are operating as designed to allow for effective pollutant removal and provide protection to receiving water bodies. It is recommended that inspections be performed multiple times during the first year to assess the site specific loading conditions. The first year of inspections can be used to set inspection and maintenance intervals for subsequent years to ensure appropriate maintenance is provided. •Inspect pre-treatment, biofiltration, and discharge chambers an average of once every six to twelve months. Varies based on site specific and local conditions. •Average inspection time is approximately 15 minutes. Always ensure appropriate safety protocol and procedures are followed. The following is a list of equipment required to allow for simple and effective inspection of the Modular Wetlands Linear: •Modular Wetlands Linear Inspection Form •Flashlight •Manhole hook or appropriate tools to remove access hatches and covers •Appropriate traffic control signage and procedures •Measuring pole and/or tape measure •Protective clothing and eye protection •7/16” open or closed ended wrench •Large permanent black marker (initial inspections only - first year) Note: entering a confined space requires appropriate safety and certification. It is generally not required for routine inspections of the system INSPECTION AND MAINTENANCE NOTES 1. Following maintenance and/or inspection, it is recommended that the maintenance operator prepare a maintenance/inspection record. The record should include any maintenance activities performed, amount and description of debris collected, and condition of the system and its various filter mechanisms. 2. The owner should keep maintenance/inspection record(s) for a minimum of five years from the date of maintenance. These records should be made available to the governing municipality for inspection upon request at any time. 3. Transport all debris, trash, organics, and sediments to approved facility for disposal in accordance with local and state requirements. 4. Entry into chambers may require confined space training based on state and local regulations. 5. No fertilizer shall be used in the biofiltration chamber. 6. Irrigation should be provided as recommended by manufacturer and/or landscape architect. Amount of irrigation required is dependent on plant species. Some plants may not require irrigation after initial establishment. 5 INSPECTION PROCESS 1. Prepare the inspection form by writing in the necessary information including project name, location, date & time, unit number and other information (see inspection form). 2. Observe the inside of the system through the access covers. If minimal light is available and vision into the unit is impaired, utilize a flashlight to see inside the system and all of its chambers. 3. Look for any out of the ordinary obstructions in the inflow pipe, pre-treatment chamber, biofiltration chamber, discharge chamber or outflow pipe. Write down any observations on the inspection form. 4. Through observation and/or digital photographs, estimate the amount of trash, debris accumulated in the pre-treatment chamber. Utilizing a tape measure or measuring stick, estimate the amount of sediment in this chamber. Record this depth on the inspection form. 5. Through visual observation, inspect the condition of the pre-filter cartridges. Look for excessive build-up of sediment on the cartridges, any build-up on the tops of the cartridges, or clogging of the holes. Record this information on the inspection form. The prefilter cartridges can be further inspected by removing the cartridge tops and assessing the color of the BioMediaGREEN filter cubes (requires entry into pre-treatment chamber - see notes previous notes regarding confined space entry). Record the color of the material. New material is a light green color. As the media becomes clogged, it will turn darker in color, eventually becoming dark brown or black. The closer to black the media is the higher percentage that the media is exhausted and is in need of replacement. 6. The biofiltration chamber is generally maintenance-free due to the system’s advanced pre-treatment chamber. For units which have open planters with vegetation, it is recommended that the vegetation be inspected. Look for any plants that are dead or showing signs of disease or other negative stressors. Record the general health of the plants on the inspection form and indicate through visual observation or digital photographs if trimming of the vegetation is required. 7. The discharge chamber houses the orifice control structure, drain down filter (only in California - older models), and is connected to the outflow pipe. It is important to check to ensure the orifice is in proper operating conditions and free of any obstructions. It is also important to assess the condition of the drain down filter media which utilizes a block form of the BioMediaGREEN. Assess in the same manner as the cubes in the pre- filter cartridge as mentioned above. Generally, the discharge chamber will be clean and free of debris. Inspect the water marks on the side walls. If possible, inspect the discharge chamber during a rain event to assess the amount of flow leaving the system while it is at 100% capacity (pre-treatment chamber water level at peak HGL - top of bypass weir). The water level of the flowing water should be compared to the watermark level on the side walls, which is an indicator of the highest discharge rate the system achieved when initially installed. Record on the form if there is any difference in level from the watermark in inches. INSPECTION •Excessive accumulation of sediment in the pre-treatment chamber of more than 6" in depth. •Excessive accumulation of sediment on the BioMediaGREEN media housed within the pre- treatment cartridges. The following chart shows photos of the condition of the BioMediaGREENcontained within the pre-filter cartridges. When media is more than 85% clogged, replacement is required. 7 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS INSPECTION •Excessive accumulation of sediment in the pre-treatment chamber of more than 6" in depth. •Excessive accumulation of sediment on the BioMediaGREEN media housed within the pre-treatment cartridges. The following chart shows photos of the condition of the BioMediaGREEN contained within the pre-filter cartridges. When media is more than 85% clogged, replacementis required. 7 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS New BioMediaGREEN 0% Exhausted BioMediaGREEN 100%85% 6 MAINTENANCE INDICATORS Based upon the observations made during inspection, maintenance of the system may be required based on the following indicators: •Missing or damaged internal components or cartridges •Obstructions in the system or its inlet and/or outlet pipes •Excessive accumulation of floatables in the pretreatment chamber in which the length and width of the chamber is fully impacted more than 18”. See photo below. •Excessive accumulation of sediment in the pretreatment chamber of more than 6” in depth. •Excessive accumulation of sediment on the BioMediaGREEN media housed within the pretreatment cartridges. The following chart shows photos of the condition of the BioMediaGREEN contained within the pre-filter cartridges. When media is more than 85% clogged, replacement is required. •Excessive accumulation of sediment on the BioMediaGREEN media housed within the pretreatment cartridges. When media is more than 85% clogged, replacement is required. The darker the BioMediaGREEN, the more clogged it is and in need of replacement. INSPECTION MAINTENANCE INDICATORS Based upon the observations made during inspection, maintenance of the system may be required based on the following indicators: •Missing or damaged internal components or cartridges •Obstructions in the system or its inlet and/or outlet pipes•Excessive accumulation of floatables in the pre-treatment chamber in which the length and width of the chamber is fully impacted more than 18". See photo below. 8.Finalize the inspection report for analysis by the maintenance manager to determine if maintenance is required. 6 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS INSPECTION •Excessive accumulation of sediment in the pre-treatment chamber of more than 6" in depth. •Excessive accumulation of sediment on the BioMediaGREEN media housed within the pre-treatment cartridges. The following chart shows photos of the condition of the BioMediaGREENcontained within the pre-filter cartridges. When media is more than 85% clogged, replacement is required. 7 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS INSPECTION MAINTENANCE INDICATORS Based upon the observations made during inspection, maintenance of the system may be required based on the following indicators: •Missing or damaged internal components or cartridges •Obstructions in the system or its inlet and/or outlet pipes•Excessive accumulation of floatables in the pre-treatment chamber in which the length and width of the chamber is fully impacted more than 18". See photo below. 8.Finalize the inspection report for analysis by the maintenance manager to determine if maintenance is required. 6 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS INSPECTION MAINTENANCE INDICATORS Based upon the observations made during inspection, maintenance of the system may be required based on the following indicators: •Missing or damaged internal components or cartridges •Obstructions in the system or its inlet and/or outlet pipes•Excessive accumulation of floatables in the pre-treatment chamber in which the length and width of the chamber is fully impacted more than 18". See photo below. 8.Finalize the inspection report for analysis by the maintenance manager to determine if maintenance is required. 6 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS NOTE: During the first few storms, the water level in the outflow chamber should be observed and a 6” long horizontal watermark line drawn (using a large permanent marker) at the water level in the discharge chamber while the system is operating at 100% capacity. The diagram below illustrates where the line should be drawn. This line is a reference point for future inspections of the system. Water level in the discharge chamber is a function of flow rate and pipe size. Observation of the water level during the first few months of operation can be used as a benchmark level for future inspections. The initial mark and all future observations shall be made when the system is at 100% capacity (water level at maximum level in the pre-treatment chamber). If future water levels are below this mark when the system is at 100% capacity, this is an indicator that maintenance to the pre-filter cartridges may be needed. 8. Finalize the inspection report for analysis by the maintenance manager to determine if maintenance is required. 7 INSPECTION PROCESS •Excessive accumulation of sediment on the BioMediaGREEN media housed within the drain down filter (California only - older models). The following photos show the condition of the BioMediaGREEN contained within the drain down filter. When media is more than 85% clogged, replacement is required. •Overgrown vegetation. •Water level in the discharge chamber during 100% operating capacity (pretreatment chamber water level at max height) is lower than the water mark by 20%. INSPECTION •Excessive accumulation of sediment on the BioMediaGREEN media housed within the drain down filter (California only - older models). The following photos show the condition of the BioMediaGREEN contained within the drain down filter. When media is more than 85% clogged, replacement is required. •Overgrown vegetation. •Water level in the discharge chamber during 100% operating capacity (pre-treatment chamber water level at max height) is lower than the watermark by 20%. 8 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS INSPECTION •Excessive accumulation of sediment on the BioMediaGREEN media housed within the drain down filter (California only - older models). The following photos show the condition of the BioMediaGREEN contained within the drain down filter. When media is more than 85% clogged, replacement is required. •Overgrown vegetation. •Water level in the discharge chamber during 100% operating capacity (pre-treatment chamber water level at max height) is lower than the watermark by 20%. 8 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 8 MAINTENANCE SUMMARY The time has come to maintain your Modular Wetlands® Linear. All necessary pre-maintenance steps must be carried out before maintenance occurs. Once traffic control has been set up per local and state regulations and access covers have been safely opened, the maintenance process can begin. It should be noted that some maintenance activities require confined space entry. All confined space requirements must be strictly followed before entry into the system. In addition, the following is recommended: •Prepare the maintenance form by writing in the necessary information including project name, location, date & time, unit number and other info (see maintenance form). •Set up all appropriate safety and cleaning equipment. •Ensure traffic control is set up and properly positioned. •Prepared pre-checks (OSHA, safety, confined space entry) are performed. The following is a list of equipment to required for maintenance of the Modular Wetlands® Linear: •Modular Wetlands Linear Maintenance Form •Manhole hook or appropriate tools to access hatches and covers •Protective clothing, flashlight, and eye protection •7/16” open or closed ended wrench •Vacuum assisted truck with pressure washer •Replacement BioMediaGREEN for pre-filter cartridges if required (order from one of Contech’s Maintenance Team members at https://www.conteches.com/maintenance). 9 MAINTENANCE | PRETREATMENT CHAMBER 1. Remove access cover over pre-treatment chamber and position vacuum truck accordingly. 2. With a pressure washer, spray down pollutants accumulated on walls and pre-filter cartridges. 3. Vacuum out pre-treatment chamber and remove all accumulated pollutants including trash, debris, and sediments. Be sure to vacuum the floor until the pervious pavers are visible and clean. 4. If pre-filter cartridges require media replacement, continue to step 5. If not, replace access cover and move to step 11. 1.MAINTENANCE (PRE-TREATMENT CHAMBER)Remove access cover over pre-treatment chamber and position vacuum truck accordingly.2.With a pressure washer, spray down pollutants accumulated on walls and pre-filter cartridges. 3.Vacuum out pre-treatment chamber and remove all accumulated pollutants including trash, debris, and sediments. Be sure to vacuum the floor until the pervious pavers are visible and clean. 4.If pre-filter cartridges require media replacement, move on to next page. If not, replace access cover. 11 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 1.MAINTENANCE (PRE-TREATMENT CHAMBER)Remove access cover over pre-treatment chamber and position vacuum truck accordingly.2.With a pressure washer, spray down pollutants accumulated on walls and pre-filter cartridges. 3.Vacuum out pre-treatment chamber and remove all accumulated pollutants including trash, debris, and sediments. Be sure to vacuum the floor until the pervious pavers are visible and clean. 4.If pre-filter cartridges require media replacement, move on to next page. If not, replace access cover. 11 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 1.MAINTENANCE (PRE-TREATMENT CHAMBER)Remove access cover over pre-treatment chamber and position vacuum truck accordingly.2.With a pressure washer, spray down pollutants accumulated on walls and pre-filter cartridges. 3.Vacuum out pre-treatment chamber and remove all accumulated pollutants including trash, debris, and sediments. Be sure to vacuum the floor until the pervious pavers are visible and clean. 4.If pre-filter cartridges require media replacement, move on to next page. If not, replace access cover. 11 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 1.MAINTENANCE (PRE-TREATMENT CHAMBER)Remove access cover over pre-treatment chamber and position vacuum truck accordingly.2.With a pressure washer, spray down pollutants accumulated on walls and pre-filter cartridges. 3.Vacuum out pre-treatment chamber and remove all accumulated pollutants including trash, debris, and sediments. Be sure to vacuum the floor until the pervious pavers are visible and clean. 4.If pre-filter cartridges require media replacement, move on to next page. If not, replace access cover. 11 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 10 MAINTENANCE | PREFILTER CARTRIDGES 5. After successfully cleaning out the pre-treatment chamber (previous page) enter the pre-treatment chamber. 6. Unscrew the two bolts (circles shown below) holding the lid on each cartridge filter and remove lid. 7. Place the vacuum hose over each individual media filter to suck out filter media. 8. Once filter media has been sucked out, use a pressure washer to spray down the inside of the cartridge and it’s media cages. Remove cleaned media cages and place to the side. Once removed, the vacuum hose can be inserted into the cartridge to vacuum out any remaining material near the bottom of the cartridge. 9. Reinstall media cages and fill with new media from the manufacturer or outside supplier. Manufacturer will provide specification of media and sources to purchase. Utilize the manufacture-provided refilling tray and place on top of the cartridge. Fill the tray with new bulk media and shake down into place. Using your hands, lightly compact the media into each filter cage. Once the cages are full, remove the refilling tray and replace the cartridge top, ensuring bolts are properly tightened. 10. Exit the pre-treatment chamber. Replace access hatch or manhole cover. 1.MAINTENANCE (PRE-FILTER CARTRIDGES) After successfully cleaning out the pre-treatment chamber (previous page) enter the pre-treatment chamber. 2. Unscrew the two bolts (red circles) holding the lid on each cartridge filter and remove lid. 3.Place the vacuum hose over each individual media filter to suck out filter media. 4.Once filter media has been sucked out, use a pressure washer to spray down the inside of the cartridge and it's media cages. Remove cleaned media cages and place to the side. Once removed, the vacuum hose can be inserted into the cartridge to vacuum out any remaining material near the bottom of the cartridge. 12 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 0 0 1. MAINTENANCE (PRE-FILTER CARTRIDGES) After successfully cleaning out the pre-treatment chamber (previous page) enter the pre-treatment chamber. 2. Unscrew the two bolts (red circles) holding the lid on each cartridge filter and remove lid. 3.Place the vacuum hose over each individual media filter to suck out filter media. 4.Once filter media has been sucked out, use a pressure washer to spray down the inside of the cartridge and it's media cages. Remove cleaned media cages and place to the side. Once removed, the vacuum hose can be inserted into the cartridge to vacuum out any remaining material near the bottom of the cartridge. 12 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 0 0 1.MAINTENANCE (PRE-FILTER CARTRIDGES)After successfully cleaning out the pre-treatment chamber (previous page) enter the pre-treatment chamber. 2. Unscrew the two bolts (red circles) holding the lid on each cartridge filter and remove lid. 3.Place the vacuum hose over each individual media filter to suck out filter media. 4.Once filter media has been sucked out, use a pressure washer to spray down the inside of the cartridge and it's media cages. Remove cleaned media cages and place to the side. Once removed, the vacuum hose can be inserted into the cartridge to vacuum out any remaining material near the bottom of the cartridge. 12 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 0 0 5. MAINTENANCE (PRE-FILTER CARTRIDGES) Reinstall media cages and fill with new media from the manufacturer or outside supplier. Manufacturer will provide specification of media and sources to purchase. utilize the manufacture-provided refilling tray and place on top of the cartridge. Fill the tray with new bulk media and shake down into place. using your hands, lightly compact the media into each filter cage. Once the cages are full, remove the refilling tray and replace the cartridge top, ensuring bolts are properly tightened. 6.Exit the pre-treatment chamber. Replace access hatch or manhole cover. 13 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 5. MAINTENANCE (PRE-FILTER CARTRIDGES) Reinstall media cages and fill with new media from the manufacturer or outside supplier. Manufacturer will provide specification of media and sources to purchase. utilize the manufacture-provided refilling tray and place on top of the cartridge. Fill the tray with new bulk media and shake down into place. using your hands, lightly compact the media into each filter cage. Once the cages are full, remove the refilling tray and replace the cartridge top, ensuring bolts are properly tightened. 6.Exit the pre-treatment chamber. Replace access hatch or manhole cover. 13 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 5. MAINTENANCE (PRE-FILTER CARTRIDGES) Reinstall media cages and fill with new media from the manufacturer or outside supplier. Manufacturer will provide specification of media and sources to purchase. utilize the manufacture-provided refilling tray and place on top of the cartridge. Fill the tray with new bulk media and shake down into place. using your hands, lightly compact the media into each filter cage. Once the cages are full, remove the refilling tray and replace the cartridge top, ensuring bolts are properly tightened. 6.Exit the pre-treatment chamber. Replace access hatch or manhole cover. 13 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 11 MAINTENANCE | BIOFILTRATION CHAMBER 11. In general, the biofiltration chamber is maintenance-free with the exception of maintaining the vegetation. The Modular Wetlands Linear utilizes vegetation similar to surrounding landscape areas, therefore trim vegetation to match surrounding vegetation. If any plants have died, replace them with new ones. 12. Each vertical under drain on the biofiltration chamber has a removable (threaded cap) that can be taken off to check any blockages or root growth. Once removed, a jetting attachment can be used to clean out the under drain and orifice riser. 13. As with all biofilter systems, at some point the biofiltration media (WetlandMedia) will need to be replaced. Either because of physical clogging of sorptive exhaustion of the media ion exchange capacity (to remove dissolved metals and phosphorous). The general life of this media is 10 to 20 years based on site specific conditions and pollutant loading. Utilize the vacuum truck to vacuum out the media by placing the hose into the chamber. Once all the media is removed use the power washer to spray down all the netting on the outer metal cage. Inspect the netting for any damage or holes. If the netting is damaged it can be repaired or replaced with guidance by the manufacturer. 14. Contact one of Contech’s Maintenance Team members at https://www.conteches.com/maintenance to order new WetlandMedia. The quantity of media needed can be determined by providing the model number and unit depth. Media will be provided in super sacks for easy installation. Each sack will weigh between 1000 and 2000 lbs. A lifting apparatus (backhoe, boom truck, or other) is recommended to position the super sack over the biofiltration chamber. Fill the media cages up to the same level as the old media. Replant with vegetation. 1.MAINTENANCE (BIOFILTRATION CHAMBER)In general, the biofiltration chamber is maintenance-free with the exception of maintaining the vegetation. Using standard gardening tools, properly trim back the vegetation to healthy levels. The MW Linear™ utilizes vegetation similar to surrounding landscape areas, therefore trim vegetation to match surrounding vegetation. If any plants have died, replace them with new ones. 14 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 3.As with all biofilter systems, at some point the biofiltration media (WetlandMedia) will need to be replaced. Either because of physical clogging of sorptive exhaustion of the media ion exchange capacity (to remove dissolved metals and phosphorous). The general life of this media is 10 to 20 years based on site specific conditions and pollutant loading. Utilize the vacuum truck to vacuum out the media by placing the hose into the chamber. Once all the media is removed use the power washer to spray down all the netting on the outer metal cage. Inspect the netting for any damage or holes. If the netting is damaged it can be repaired or re- placed with guidance by the manufacturer. 4.The first step is to contact the manufacturer and order new WetlandMedia. The quantity of media needed can be determined by providing the model number and unit depth. Media will be provided in super sacks for easy installation. Each sack will weigh between 1000 and 2000 lbs. A lifting apparatus (backhoe, boom truck, or other) is rec-ommended to position the super sack over the biofiltration chamber. Fill the media cages up to the same level as the old media. Replant with vegetation. 2.Each vertical under drain on the biofiltration chamber has a removable (threaded) that can be taken off to check any blockages or root growth. Once removed a a jetting attachment can be used to clean out the under drain and orifice riser. 1.MAINTENANCE (BIOFILTRATION CHAMBER)In general, the biofiltration chamber is maintenance-free with the exception of maintaining the vegetation. Using standard gardening tools, properly trim back the vegetation to healthy levels. The MW Linear™ utilizes vegetation similar to surrounding landscape areas, therefore trim vegetation to match surrounding vegetation. If any plants have died, replace them with new ones. 14 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 3.As with all biofilter systems, at some point the biofiltration media (WetlandMedia) will need to be replaced. Either because of physical clogging of sorptive exhaustion of the media ion exchange capacity (to remove dissolved metals and phosphorous). The general life of this media is 10 to 20 years based on site specific conditions and pollutant loading. Utilize the vacuum truck to vacuum out the media by placing the hose into the chamber. Once all the media is removed use the power washer to spray down all the netting on the outer metal cage. Inspect the netting for any damage or holes. If the netting is damaged it can be repaired or re- placed with guidance by the manufacturer. 4.The first step is to contact the manufacturer and order new WetlandMedia. The quantity of media needed can be determined by providing the model number and unit depth. Media will be provided in super sacks for easy installation. Each sack will weigh between 1000 and 2000 lbs. A lifting apparatus (backhoe, boom truck, or other) is rec-ommended to position the super sack over the biofiltration chamber. Fill the media cages up to the same level as the old media. Replant with vegetation. 2.Each vertical under drain on the biofiltration chamber has a removable (threaded) that can be taken off to check any blockages or root growth. Once removed a a jetting attachment can be used to clean out the under drain and orifice riser.1. MAINTENANCE (BIOFILTRATION CHAMBER) In general, the biofiltration chamber is maintenance-free with the exception of maintaining the vegetation. Using standard gardening tools, properly trim back the vegetation to healthy levels. The MW Linear™ utilizes vegetation similar to surrounding landscape areas, therefore trim vegetation to match surrounding vegetation. If any plants have died, replace them with new ones. 14 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 3.As with all biofilter systems, at some point the biofiltration media (WetlandMedia) will need to be replaced. Either because of physical clogging of sorptive exhaustion of the media ion exchange capacity (to remove dissolved metals and phosphorous). The general life of this media is 10 to 20 years based on site specific conditions and pollutant loading. Utilize the vacuum truck to vacuum out the media by placing the hose into the chamber. Once all the media is removed use the power washer to spray down all the netting on the outer metal cage. Inspect the netting for any damage or holes. If the netting is damaged it can be repaired or re- placed with guidance by the manufacturer. 4.The first step is to contact the manufacturer and order new WetlandMedia. The quantity of media needed can be determined by providing the model number and unit depth. Media will be provided in super sacks for easy installation. Each sack will weigh between 1000 and 2000 lbs. A lifting apparatus (backhoe, boom truck, or other) is rec-ommended to position the super sack over the biofiltration chamber. Fill the media cages up to the same level as the old media. Replant with vegetation. 2.Each vertical under drain on the biofiltration chamber has a removable (threaded) that can be taken off to check any blockages or root growth. Once removed a a jetting attachment can be used to clean out the under drain and orifice riser. 12 MAINTENANCE | DISCHARGE CHAMBER 15. Remove access hatch or manhole cover over discharge chamber. 16. Enter chamber to gain access to the drain down filter. Unlock the locking mechanism and lift up drain down filter housing to remove used BioMediaGREEN filter block as shown below. NOTE: Drain down filter is only found on units installed in California prior to 2023. If no drain down filter is present, skip steps 16 and 17. 17. Insert a new BioMediaGREEN filter block and lock drain down filter housing back in place. 18. Replace access hatch or manhole cover over discharge chamber. INSPECTION •Excessive accumulation of sediment on the BioMediaGREEN media housed within the drain down filter (California only - older models). The following photos show the condition of the BioMediaGREEN contained within the drain down filter. When media is more than 85% clogged, replacement is required. •Overgrown vegetation. •Water level in the discharge chamber during 100% operating capacity (pre-treatment chamber water level at max height) is lower than the watermark by 20%. 8 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS INSPECTION •Excessive accumulation of sediment on the BioMediaGREEN media housed within the drain down filter (California only - older models). The following photos show the condition of the BioMediaGREEN contained within the drain down filter. When media is more than 85% clogged, replacement is required. •Overgrown vegetation. •Water level in the discharge chamber during 100% operating capacity (pre-treatment chamber water level at max height) is lower than the watermark by 20%. 8 ©2022 COPYRIGHT | CONTECH ENGINEERED SOLUTIONS 13 NOTES _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ 14 For Office Use Only (city)(Zip Code)(Reviewed By) Owner / Management Company (Date) Contact Phone ( )_ Inspector Name Date //Time AM / PM Weather Condition Additional Notes Yes Depth: Yes No Modular Wetland System Type (Curb, Grate or UG Vault):Size (22', 14' or etc.): Other Inspection Items: Storm Event in Last 72-hours? No YesType of Inspection Routine Follow Up Complaint Storm Office personnel to complete section to the left. Inspection Report Modular Wetlands Linear Is the filter insert (if applicable) at capacity and/or is there an accumulation of debris/trash on the shelf system? Does the cartridge filter media need replacement in pre-treatment chamber and/or discharge chamber? Any signs of improper functioning in the discharge chamber? Note issues in comments section. Chamber: Is the inlet/outlet pipe or drain down pipe damaged or otherwise not functioning properly? Structural Integrity: Working Condition: Is there evidence of illicit discharge or excessive oil, grease, or other automobile fluids entering and clogging the unit? Is there standing water in inappropriate areas after a dry period? Damage to pre-treatment access cover (manhole cover/grate) or cannot be opened using normal lifting pressure? Damage to discharge chamber access cover (manhole cover/grate) or cannot be opened using normal lifting pressure? Does the MWS unit show signs of structural deterioration (cracks in the wall, damage to frame)? Project Name Project Address Inspection Checklist CommentsNo Does the depth of sediment/trash/debris suggest a blockage of the inflow pipe, bypass or cartridge filter? If yes, specify which one in the comments section. Note depth of accumulation in in pre-treatment chamber. Is there a septic or foul odor coming from inside the system? Is there an accumulation of sediment/trash/debris in the wetland media (if applicable)? Is it evident that the plants are alive and healthy (if applicable)? Please note Plant Information below. Sediment / Silt / Clay Trash / Bags / Bottles Green Waste / Leaves / Foliage Waste:Plant Information No Cleaning Needed Recommended Maintenance Additional Notes: Damage to Plants Plant Replacement Plant Trimming Schedule Maintenance as Planned Needs Immediate Maintenance ENGINEERED SOLUTIONS 15 For Office Use Only (city)(Zip Code)(Reviewed By) Owner / Management Company (Date) Contact Phone ( )_ Inspector Name Date //Time AM / PM Weather Condition Additional Notes Site Map # Comments: Inlet and Outlet Pipe Condition Drain Down Pipe Condition Discharge Chamber Condition Drain Down Media Condition Plant Condition Media Filter Condition Long: MWS Sedimentation Basin Total Debris Accumulation Condition of Media 25/50/75/100 (will be changed@ 75%) Operational Per Manufactures' Specifications (If not, why?) Lat:MWS Catch Basins GPS Coordinates of Insert Manufacturer / Description / Sizing Trash Accumulation Foliage Accumulation Sediment Accumulation Type of Inspection Routine Follow Up Complaint Storm Storm Event in Last 72-hours? No Yes Office personnel to complete section to the left. Project Address Project Name Cleaning and Maintenance Report Modular Wetlands LinearENGINEERED SOLUTIONS SUPPORT DRAWINGS AND SPECIFICATIONS ARE AVAILABLE AT WWW.CONTECHES.COM © 2023 CONTECH ENGINEERED SOLUTIONS LLC, A QUIKRETE COMPANY 800-338-1122 WWW.CONTECHES.COM ALL RIGHTS RESERVED. PRINTED IN THE USA. CONTECH ENGINEERED SOLUTIONS LLC PROVIDES SITE SOLUTIONS FOR THE CIVIL ENGINEERING INDUSTRY. CONTECH’S PORTFOLIO INCLUDES BRIDGES, DRAINAGE, SANITARY SEWER, STORMWATER AND EARTH STABILIZATION PRODUCTS. FOR INFORMATION ON OTHER CONTECH DIVISION OFFERINGS, VISIT CONTECHES.COM OR CALL 800-338-1122. Modular Wetlands Maintenance Guide 1/2023 NOTHING IN THIS CATALOG SHOULD BE CONSTRUED AS A WARRANTY. APPLICATIONS SUGGESTED HEREIN ARE DESCRIBED ONLY TO HELP READERS MAKE THEIR OWN EVALUATIONS AND DECISIONS, AND ARE NEITHER GUARANTEES NOR WARRANTIES OF SUITABILITY FOR ANY APPLICATION. CONTECH MAKES NO WARRANTY WHATSOEVER, EXPRESS OR IMPLIED, RELATED TO THE APPLICATIONS, MATERIALS, COATINGS, OR PRODUCTS DISCUSSED HEREIN. ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR PURPOSE ARE DISCLAIMED BY CONTECH. SEE CONTECH’S CONDITIONS OF SALE (AVAILABLE AT WWW.CONTECHES.COM/COS) FOR MORE INFORMATION. ENGINEERED SOLUTIONS Decembr 08, 2023 Attachment 4: City Standard Single-Sheet BMP (SSBMP) Exhibit x x x x x x x x x x x x x x x 2'' W 2'' W 2'' W 2'' W 2'' W 2''W 2''W 2''W 2''W S3 S3 J J J J J J J J J J J J GG G G G G G G G G G G J J J J J J GG G G 2'' W 2'' W 2'' W 2'' W 2'' W 2''W 2''W 2''W 2''W AC- 1 AC - 2 G G G G G G GW GW GW ICB ICB ICBICBICB ICB ICB ICB ICB ICB MMM MMM MMMMMMMMMMMM MMMMMMMMMMMMMMM 1 5 2 0 2 5 3 0 12 121 3 13 1 4 1 6 1 7 1 8 1 9 2 1 2 2 2 3 2 4 2 6 2 7 2 8 2 9 3 1 3 2 -20 -2 3 -2 2 -2 1 -19 -1 8 -15 -10 -17 -16 -14 -1 3 -1 2 -11 -9 17 18 19 18 18 36 37 38 35 33 31 29 27 3032 28 26 PROPERTY LINE EASEMENT H EXISTING ACCESS ROAD ACCESS ROAD EASEMENT C EXISTING ACCESS ROAD EASEMENT D EASEMENT C ROW FLOATING BOOM FINE SCREENING FACILITY INCLUDING SCREENING EQUIPMENT AND DECK ACCESS DEBRIS BIN AREA DEBRIS RETURN BOAT RAMP ELECTRICAL BUILDING EXISTING ELECTRICAL BUILDING BULKHEAD FOR TUNNEL ISOLATION STORM DRAIN EXTENSION 88-INCH FEEDER CONNECTION EXISTING FOREBAY EASEMENT T EAST RAMP WEST RAMP BRIDGE TEMPORARY MARINE RESEARCH PORTABLE CONTAINER (WILL BE REMOVED AFTER CONSTRUCTION) EXISTING BIORETENTION POND STORM DRAIN MANHOLE EXISTING LANDSCAPE AREA DISCHARGE POND EXISTING CDP-IPS CARLSBAD BLVD EXISTING BRINE LINE 18" STORM DRAIN PLAN SCALE: 1" = 40' BMP TYPEBMP ID #SYMBOL CASQA NO.DRAWING NO.SHEET NO.(S)MAINTENANCE FREQUENCY BMP TABLE 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 INSTALLATION. BMP NOTES: PARTY RESPONSIBLE FOR MAINTENANCE: NAME ADDRESS PHONE NO. CONTACT PLAN PREPARED BY: NAME ADDRESS PHONE NO. CERTIFICATION COMPANY INSPECTION FREQUENCYQUANTITY TREATMENT CONTROL SOURCE CONTROL 5. REFER TO MAINTENANCE AGREEMENT DOCUMENT. 1 MONTHLY1 EA 539-8A 14, 15, 21 ** 6. SEE PROJECT SWQMP (FORM E-35) FOR ADDITIONAL INFORMATION. SIGNATURE *CHOOSE FROM THE LIST BELOW FOR COMPLETING THE FIELDS IN THE INSPECTIONS & MAINTENANCE FRENQUENCY COLUMNS: ANNUAL SEMI-ANNUALLY QUARTERLY BIMONTHLY MONTHLY AS NEEDED NONE WEEKLY 1 TIME PER YEAR 2 TIMES PER YEAR 3 TIMES PER YEAR 4 TIMES PER YEAR BI-ANNUALLY BMP CONSTRUCTION AND INSPECTION NOTES: THE ENGINEER ON WATCH (EOW) WILL VERIFY THAT PERMANENT BMPS ARE CONSTRUCTED AND OPERATING IN COMPLIANCE WITH THE APPLICABLE REQUIREMENTS. PRIOR TO OCCUPANCY THE EOW MUST PROVIDE: 1.PHOTOGRAPHS OF THE INSTALLATION OF PERMANENT BMPS PRIOR TO CONSTRUCTION, DURING CONSTRUCTION, AND AT FINAL INSTALLATION. 2.A WET STAMPED LETTER VERIFYING THAT PERMANENT BMPS ARE CONSTRUCTED AND OPERATING PER THE REQUIREMENTS OF THE APPROVED PLANS. 3.PHOTOGRAPHS TO VERIFY THAT PERMANENT WATER QUALITY TREATMENT SIGNAGE HAS BEEN INSTALLED. PRIOR TO RELEASE OF SECURITIES, THE DEVELOPER IS RESPONSIBLE FOR ENSURING THE PERMANENT BMPS HAVE NOT BEEN REMOVED OR MODIFIED BY THE NEW HOMEOWNER OR HOA WITHOUT THE APPROVAL OF THE CITY ENGINEER. 3 STORM DRAIN STENCIL SD-20 (DEV)DRAINS TO OCEANNO DUMPING POSEIDON RESOURCES (CHANNELSIDE) LP 4590 CARLSBAD BLVD. CARLSBAD, CA 92008 MICHELLE PETERS (760) 655-3900 BILL FLORES HDR, Inc. 3230 EL CAMINO REAL IRVINE, CA 92602 (951) 320-7311 539-8A 18, 21 AS NEEDEED AS NEEDED2 EA PROPRIETARY BIOFILTRATION (MWS)MP-20 1 32 2 MONTHLY1 EA 539-8A 18 AS NEEDEDBIOFILTRATION BASIN (BF-1)TC-32 3 32 "DECLARATION OF RESPONSIBLE CHARGE" I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THE PORTION OF THE PROJECT SHOWN ON SHEET XX, THAT I HAVE EXERCISED RESPONSIBLE CHARGE OVER THE DESIGN OF THIS PORTION OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONS CODE, AND THAT THE DESIGN IS CONSISTENT WITH CURRENT STANDARDS. I UNDERSTAND THAT THE CHECK OF THE PROJECT DRAWINGS AND SPECIFICATIONS BY THE CITY OF CARLSBAD DOES NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITY FOR PROJECT DESIGN. FIRM: HDR ENGINEERING INC. ADDRESS: 3230 EL CAMINO REAL, STE 200 CITY, STATE: IRVINE, CA 92602 TELEPHONE: (714) 368-5636 BY: JANELLE M. MOYER R.C.E. NO.:C70050 REGISTRATION EXPIRATION DATE: 9-30-24 3131 Decembr 08, 2023 Attachment 5: Pre-Phase 1 & Phase 1 Information Imagine the result Kiewit Shea Desalination Storm Water Management Plan (SWMP 12-22) Carlsbad Desalination Plant, RP 05-12A DWG 463-6D August 18, 2015 Source: Pre-Phase 1, Storm Water Management Plan (SWMP 12-22), CDP RP 05-12A, by Malcolm Pirnie & Arcadis, August 18, 2025 Source: Pre-Phase 1, Storm Water Management Plan (SWMP 12-22), CDP RP 05-12A, by Malcolm Pirnie & Arcadis, August 18, 2025 \\arcadis-us.com\officedata\losangeles-ca\projects\04354003 - poseidon\0000 - carlsbad desal\susmp\archive\carlsbad poseidon - susmp 2015-08-18 - updated.doc 24 Carlsbad Desalination Plant SWMP re-graded slopes will be hydro-seeded. This area is considered a “self-treating” area and does not require further stormwater mitigation. Self-Treating Area 3, approximately 0.22 acre in size, consists of re-grading along existing slopes on the west side of the Project Site and on the north side of the main access road. The re-grading will cover the existing open drainage channel, which will be replaced with a new culvert and an inlet at sump. The re-graded slopes will be hydro-seeded. This area is considered a “self-treating” area and does not require further stormwater mitigation. Self-Retaining Area 3, approximately 0.31 acre in size, consists of northern half of the intake pump station area. This area will drain north towards existing landscaping, which drains to the north. The ratio of impervious area (0.12 acre) to pervious area (0.19 acre) is 0.61 to 1. This drainage area is considered a “self-retaining area” and does not require further stormwater mitigation. Self-Retaining Area 4, approximately 0.26 acre in size, consists of southern half of the intake pump station area. This area will drain north towards new landscaping area with a minimum of 1-inch depression, which drains to the south. The ratio of impervious area (0.15 acre) to pervious area (0.12 acre) is 1.27 to 1. This drainage area is considered a “self-retaining area” and does not require further stormwater mitigation. 7.3 BMP Sizing Per City of Carlsbad SUSMP, selected BMPs are sized to meet either volume-based or flow-based numeric sizing requirements. For this Project, pervious pavements are sized to effectively treat 85th percentile storm event runoff volume from its tributary drainage areas. Vegetated swales are required to effectively treat 85th percentile storm event peak flowrate from tributary drainage areas. However, vegetated swales are actually sized to convey stormwater 10-year storm event peak flowrate for the purpose of drainage conveyance. Pervious pavement and underground detention pipes, combined together, are also sized to detain the 10-year runoff volume difference between existing and proposed conditions. Low flow pipes from the underground detention pipes are sized to release no greater than 85th percentile storm event peak flowrate from tributary drainage areas. See Appendix F for drainage calculations and detailed BMP sizing calculations for pervious pavements, vegetated swales, underground detention pipes, and low flow pipes from detention pipes. See Carlsbad Desalination Plant Drainage Report (RP 05- Source: Pre-Phase 1, Storm Water Management Plan (SWMP 12-22), CDP RP 05-12A, by Malcolm Pirnie & Arcadis, August 18, 2025 Appendix E Single Sheet Post-Construction BMP Exhibit Source: Pre-Phase 1, Storm Water Management Plan (SWMP 12-22), CDP RP 05-12A, by Malcolm Pirnie & Arcadis, August 18, 2025 CARLSBAD DESALINATION PROJECT E˜ ˜ ˜12 ˜SW˜ P B˜ P SITE PLAN˜ POST˜CONSTRUCTION B˜ P E˜ ˜ IBIT 2 SINGLE S˜ EET It's implied that Areas 3 and 4 are not self-treating, but self-retaining areas per the legend and the narrative. Source: Pre-Phase 1, Storm Water Management Plan (SWMP 12-22), CDP RP 05-12A, by Malcolm Pirnie & Arcadis, August 18, 2025 SAN DIEGO CARLSBAD EL CAJON POWAY ENCINITAS OCEANSIDE VISTA SAN MARCOS ESC O N D I D O SANTEE DEL MAR SOLANA BEACH RANCHO SANTA FE PROJECT SITE www.tetratech.com CLIENT INFORMATION:PROJECT LOCATION: PROJECT DESCRIPTION / NOTES: Tt PROJECT No.:CLIENT PROJECT No.: ISSUED: POSEIDON CHANNELSIDE CARLSBAD DESALINATION PLANT INTAKE PUMP STATION PHASE 1 4600 CARLSBAD BLVD, CARLSBAD, CA 92008 200-35200-19001 POSEIDON CHANNELSIDE 17885 Von Karman Ave, Ste 500 Irvine, California 92614 Phone: (949) 809-5000 Fax: (949) 809-5010 EARLY START SUBMITTAL - 9/04/2019 60% SUBMITTAL - 10/25/2019 90% SUBMITTAL - 12/06/2019 100% SUBMITTAL - 02/07/2020 APPROVED FOR CONSTRUCTION - 03/18/2020 VICINITY MAP: LOCATION MAP PLANS PREPARED BY: (949) 809-5000 (949) 809-5010 FAX Irvine, California 92614-6213 TETRA TECH 17885 Von Karman Avenue, Suite 500 AND APPROVED FOR CONSTRUCTION MARCH 2020 NTS N NTS 3/18/20 2'' W PROJECT SITE CP "IPS" ELEV 18.694' N:1995684.70 E: 6228716.97 CP "CDP" ELEV 38.759' N: 1995595.46 E: 6229383.53 MARK DATE DESCRIPTION BY CHKD: DRWN: PROJ: DESN: www.tetratech.com 3/ 1 8 / 2 0 2 0 3 : 2 4 : 0 5 P M - O : \ P R O J E C T S \ I R V I N E \ 3 5 2 0 0 \ 2 0 0 - 3 5 2 0 0 - 1 9 0 0 1 \ C A D \ S H E E T F I L E S \ G - 0 0 0 3 - I N D E X M A P B O B B E N C H U T I L S . D W G - J O H N S O N , W I L L I E 1 A 2 3 4 5 6 7 B C D E F Bar measures 1 inch, otherwise drawing not to scale Co p y r i g h t : T e t r a T e c h 200-35200-19001 CARLSBAD DESALINATION PLANTINTAKE PUMP STATION PHASE 1 POSEIDON CHANNELSIDE 17885 Von Karman Ave, Suite 500Irvine, CA 92614 Tel: (949) 809-5000 Fax: (949) 809-5010 3/18/20 APPROVED FOR CONSTRUCTION G-0003INDEX MAP, BASIS OF BEARINGS, BENCHMARK, UTILITY AGENCY LIST KAB RJW SDT DISCLAIMER THESE DOCUMENTS HAVE BEEN PREPARED FOR A SPECIFIC PROJECT AND SHALL NEITHER BE ALTERED NOR REUSED FOR ANY OTHER PURPOSE. ALSO, THESE DOCUMENTS DO NOT REPRESENT AS-BUILT CONDITIONS. IF THESE DOCUMENTS ARE ALTERED INTENTIONALLY OR UNINTENTIONALLY, OR REUSED WITHOUT THE DESIGN ENGINEER'S WRITTEN APPROVAL, IT WILL BE AT THE SOLE RISK AND RESPONSIBILITY OF THE USER. THE ACT OF ALTERING OR REUSING ISCONSTRUED AS INDEMNIFYING AND HOLDING THE DESIGN ENGINEERING FIRM AND ITS EMPLOYEES HARMLESS FROMALL CLAIMS, DAMAGES, AND EXPENSES, INCLUDING ATTORNEY FEES, ARISING OUT OF SUCH ACT. THE BASIS OF BEARINGS FOR THIS SURVEY IS THE NAD83 , ZONE 6, GRID BEARING BETWEEN FIRST ORDER STATION"141" AND FIRST ORDER STATION "052", AS SHOWN ON RECORD OF SURVEY NO.17271, (CITY OF CARLSBAD SURVEY CONTROL NETWORK) S 47°35'33" E. QUOTED BEARINGS FROM REFERENCE MAPS OR DEEDS MAY OR MAY NOT BE IN TERMS OF SAID SYSTEM. THE COMBINED SCALE FACTOR AT STATION "141" IS 0.999963560 GRID DISTANCE = GROUND DISTANCE MULTIPLIED BY THE COMBINED SCALE FACTOR. 141 = FOUND A 2.5-INCH BRASS DISC, STAMPED "CLSB-141 LS 6215" IN SOUTH EAST CORNER OF CONCRETE VAULT. N: 1,998,491.112 E: 6,226,887.845 EPOCH 1991.35 052 = FOUND A 2.5-INCH BRASS DISC, STAMPED "CLSB-052 LS 6215" IN CONCRETE SIDEWALK.N: 1,991,146.608 E: 6,234,928.995 EPOCH 1991.35 141 TO 052 = S 47°35'33" E, 10,893.45' GRID RECORD, 10,893.36' GRID MEASURED. SURVEY DATA DESCRIPTION: NO 57 "CLSB-057" LOCATION: S.W. CORNER OF AVENIDA ENCINAS AND CANNON ROADRECORDED: ROS 17271ELEVATION: 44.01 MSLDATUM: NGVD 29 BENCH MARK: BASIS OF BEARINGS: THE BENCHMARK FOR THIS SURVEY IS THE CITY OF CARLSBAD SURVEY CONTROL NETWORK POINT "057" AS SHOWN ONRECORDOF SURVEY 17271. A 2.5-INCH BRASS DISC, STAMPED "CLSB-057LS 6215", SET IN THE TOP OF A STORM DRAIN CURB INLET LOCATED AT THE SOUTHWESTERLY RETURN OF CANNON ROAD AND AVENIDA ENCINAS. ELEVATION = 44.010 NGVD 29 SCALE: 1"=100' INDEX MAP PROJECT SITE ADDRESS: 4600 CARLSBAD BLVD, CARLSBAD, CA 92008 N PATRICIA SLADEK AT&T DISTRIBUTION 4220 ARIZONA ST. RM 100 SAN DIEGO, CA 92104 OFFICE: 619-574-3661 CITY OF CARLSBAD- PUBLIC WORKS ENGINEERING 1635 FARADAY AVE CARLSBAD, CA 92008 OFFICE: 760-688-5150 CITY OF CARLSBAD MWD 1635 FARADAY AVE CARLSBAD, CA 92008 OFFICE: 760-802-4756 DEAN BOYERSMCI (VERIZON BUSINESS) 2400 N GLENVILLE RICHARDSON, TX 75082 OFFICE: 972-729-6322 PETER MATKOWSKI CROWN CASTLE 2125 WRIGHT AVE STE C9 LAVERNE, CA 91750 OFFICE: 626-320-0996 ROSELYN SQUIRES SC GAS ALISO VIEJO- TRANSMISSION 9400 OAKDALE CHATSWORTH, CA 91311 OFFICE: 818-701-4546 JANI KIKUTZ SDG&E - GAS TRANSMISSION 6875 CONSOLIDATED WAY SAN DIEGO, CA 92121 OFFICE: 858-547-2054 BOBBY HORVATH SDG&E 8315 CENTURY PARK CT, CP22A SAN DIEGO, CA 92123 OFFICE: 858-636-5521 DEAN TATEYAMASDG&E TELE COMM (FIBER OPTIC) 9060 FRIARS ROAD SAN DIEGO, CA 92123 OFFICE: 619-260-5712 FRANK ECK FREEDOM TELECOMMUNICATIONS 4505 GLENCEE AVE MARINA DEL REY, CA 92092 OFFICE: 310-823-3336 MARK STANFIELD TIME WARNER CABLE 10450 PACIFIC CENTER CT SAN DIEGO, CA 92121 OFFICE: 858-805-7330 ED SPEACHTCOX COMMUNICATIONS 5159 FEDERAL BLVD SAN DIEGO, CA 92105 OFFICE: 760-806-2035 KINDER MORGAN ENERGY PARTNERS/SFPP 9950 SAN DIEGO MISSION ROAD SAN DIEGO, CA 92108 OFFICE: 619-778-8049 AURA BULURAN LEVEL 3 COMMUNICATIONS 1025 ELDORADO BLVD, BLDG 33A-522 BROOMFIELD, CO 80021 OFFICE: 720-888-6482 UTILITY AGENCY LIST PURSUANT TO ASSEMBLY BILL 3019, NO EXCAVATION PERMIT IS VALID UNLESS THE FOLLOWING IS PERFORMED: UNDERGROUND SERVICE ALERT HAS BEEN CONTACTED AND HAS PROVIDED INQUIRY I.D. # B193380440 1. THE UNDERSIGNED AGREES TO CONTACT AND OBTAIN AN INQUIRY I.D. # FROM UNDERGROUND SERVICE ALERT (1-800-422-4133) AT LEAST TWO (2) WORKING DAYS PRIOR TO THE COMMENCEMENT OF EXCAVATION. SIGNED DATE ___________ NOTICE TO CONTRACTOR BUILDING PERMIT: CITY OF CARLSBAD - BUILDING DIVISION PERMIT NO. TBD GRADING PERMIT: CITY OF CARLSBAD - PLANNING PERMIT NO. GR2019-0036 LANDSCAPE PERMIT: CITY OF CARLSBAD - LAND DEVELOPMENT ENGINEERING PERMIT NO. DEV2019-0190 RIGHT-OF-WAY PERMIT: CITY OF CARLSBAD - LAND DEVELOPMENT ENGINEERING PERMIT NO. TBD PERMIT LIST x x xxxxxxxxx x xx xx 2''W 2''W 2''W 2''W 2''W 2'' W 2 ' ' W 2 ' ' W 2 ' ' W 2 ' ' W S3 S3 AC-1 AC-2 EXISTING CDP-IPS LAGOON PROPOSED ELECTRICAL BUILDING, SEE SHEETS C-2101, S-2101 AND E-1102 EXISTING INTAKE/DISCHARGE STRUCTURE, SEE STRUCTURAL SHEETS FOR PROPOSED MODIFICATIONS EXISTING 63" HDPE BRINE DISCHARGE, PROTECT IN PLACE 63" HDPE SDR21 BRINE DISCHARGE, SEE SHEET C-3101 FOR PLAN AND PROFILE EXISTING INTAKE TUNNELS BELOW GRADE, PROTECT IN PLACE EXISTING BRINE DISCHARGE VAULT,SEE DETAIL 1 ON SHEET C-3501 FOR VAULT MODIFICATIONS C A R L S B A D B L V D . DILUTION PUMP STATION SEE SHEET D-1101 FOR PROPOSEDPUMPS AND DISCHARGE PIPING 3 4 2 1 6 5 10 7 12 8 PROTECT IN PLACE EXISTING UTILITIES 9 14 13 INSTALL INSERT STYLE FLOW METER AND ACCESS MANHOLE,SEE DETAIL 2 ON SHEET C-3501 PROPOSED RETAINING WALL,SEE SHEET S-2101 REPAIR ASPHALT ROAD, SEE DETAIL 4 PER SHEET C-3501 15 EXISTING NRG SECURITY SHACK D I S C H A R G E T U N N E L PROTECT IN PLACE FISH FARM ACCESS GATE I N T A K E T U N N E L ( W E S T ) 16 I N T A K E T U N N E L ( E A S T ) 16'-0" SEE PARTIAL PLANS ON SHEETC-1105 AND C-4501 SECURITY FENCE,SEE NOTE 211 SECURITY FENCE, SEE NOTE 2 INSTALL SECURITY FENCE;NOTE 2 INSTALL SECURITY FENCE; NOTE 2 PROPOSED DEFLECTION BLOCKS SEE SHEET C-1104 EXISTING DOCK 17 PROPOSED BIORETENTIONBASIN, SEE SHEET C-2101 M POINT OF CONNECTION (SEE NOTE 4) WATER METER (SEE NOTE 4) 2" PVC WATER, SEE SHEET C-3101 FOR PLAN AND PROFILE PROPOSED FLOATING DOCK RELOCATION, SEE SHEET C-1104 20 18 2" PVC WATER LINE(SEE NOTE 4) 2" PVCWATER TEE 19 EASEMENT H MARK DATE DESCRIPTION BY CHKD: DRWN: PROJ: DESN: www.tetratech.com 3/ 1 9 / 2 0 2 0 4 : 3 8 : 2 2 P M - O : \ P R O J E C T S \ I R V I N E \ 3 5 2 0 0 \ 2 0 0 - 3 5 2 0 0 - 1 9 0 0 1 \ C A D \ S H E E T F I L E S \ C - 1 1 0 2 S I T E P L A N I N T A K E A R E A . D W G - J O H N S O N , W I L L I E 1 A 2 3 4 5 6 7 B C D E F Bar measures 1 inch, otherwise drawing not to scale Co p y r i g h t : T e t r a T e c h 200-35200-19001 CARLSBAD DESALINATION PLANTINTAKE PUMP STATION PHASE 1 POSEIDON CHANNELSIDE 17885 Von Karman Ave, Suite 500Irvine, CA 92614 Tel: (949) 809-5000 Fax: (949) 809-5010 3/18/20 APPROVED FOR CONSTRUCTION C-1102SITE PLAN INTAKE/DISCHARGE STRUCTURE AREA KMB RJW SDT N 0 SCALE: 10' 20'40' 1'' = 20'MATCHLINE SEE SHEET C-4102 NORTHING EASTING DESCRIPTION 1 1995545.72 6228584.39 EXISTING BRINE DISCHARGE VAULT CONNECTION 2 1995536.67 6228562.60 63" HDPE SDR21 90° BEND 3 1995728.65 6228482.85 63" HDPE SDR21 30° BEND 4 1995735.40 6228483.74 EXISTING INTAKE STRUCTURE CONNECTION 5 1995693.92 6228593.66 NORTHWEST END OF RETAINING WALL 6 1995666.92 6228601.08 SOUTHWEST CORNER OF RETAINING WALL 7 1995691.46 6228690.43 SOUTHEAST CORNER OF RETAINING WALL 8 1995709.46 6228685.49 NORTHEAST END OF RETAINING WALL 9 1995703.02 6228657.01 NORTHEAST CORNER OF ELECTRICAL BUILDING MAT FOUNDATION 10 1995678.81 6228620.45 SOUTHWEST CORNER OF ELECTRICAL BUILDING MAT FOUNDATION 11 1995693.62 6228671.26 SOUTHWEST CORNER OF TRANSFORMER 12 1995704.58 6228680.95 NORTHEAST CORNER OF TRANSFORMER 13 1995675.33 6228604.64 SOUTHWEST CORNER OF TRANSFORMER 14 1995689.26 6228609.11 NORTHEAST CORNER OF TRANSFORMER 15 1995678.66 6228626.54 CENTER OF AC UNIT 16 1995686.61 6228655.47 CENTER OF AC UNIT 17 1995653.19 6228622.44 CENTER OF OVERFLOW STRUCTURE 18 1995555.53 6228607.92 CENTER OF BRINE FLOW METER ACCESS MANHOLE 19 1995787.34 6228387.75 NORTHEAST CORNER OF DOCK 20 1995773.89 6228384.05 SOUTHWEST CORNER OF DOCK # PLAN SCALE: 1" = 20' NOTES: 1. CONTRACTOR SHALL INSTALL BULKHEADS TO BE WATER TIGHT. NEW OR EXISTING BULKHEADS MAY BE USED, BUT WILL REQUIRE MODIFICATIONS TO PROVIDE A WATER TIGHT SEAL. 2. MAINTAIN SECURITY AT ALL TIMES. 3. THE CONTRACTOR SHALL PAINT ALL ABOVE GROUND PIPELINES AND ALL ELECTRICAL BUILDING WALLS WITH A COLOR THAT WILL BLEND WITH THE SURROUNDING AREA AND IS APPROVED BY THE CITY OF CARLSBAD. 4. IRRIGATION DESIGN IS DIAGRAMMATIC. ALL IRRIGATION EQUIPMENT IS TO BE INSTALLED WITHINPLANTING AREAS. SEE IRRIGATION PLAN. xxxxxx x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx x xxxxxx x x x x x x 8" CMU RETAINING WALL, MAX ELEV = 18' (HEIGHT VARIES FIELD VERIFY) SEE SHEET S2101 GRAVEL OVER COMPACTED NATIVE SOIL (SEE NOTE 2) 28 . 0 0 ' APPROXIMATE LOCATION OFEXISTING FENCE 92.67' 18 . 6 7 ' APPROXIMATE LOCATION OF PROPOSED FENCE. (FIELD VERIFY LOCATION OF FENCE AFTERLOCATION OF RETAINING WALL IS SET) 6.08' 6. 5 0 ' 5.00' TRANSFORMER PAD FF 14.50 SEE SHT S-2101 TRANSFORMER PAD FF 15.50 SEE SHT S-2101 6. 5 0 ' EXISTING CURB TO REMAIN REPLACE IN KIND IF DAMAGED 5.00' 2%MAX 6" DIA REMOVABLEBOLLARD (TYPICAL) SEE DTL 2 ON THIS SHT 5.00' PROPOSED PREFAB 40'x12' ELECTRICAL BUILDING AND MAT FOUNDATION FF 14.50 SEE SHT S-2101 5. 6 7 ' TRUNCATED DOMES PER SANDIEGO REGIONAL STD DWG G-29 SECURITY FENCETO MATCH EXISTING 6.00' TYP 3. 0 0 ' 16.75'16.75' SECURITY FENCE PERSAN DIEGO REGIONAL STD DWG M-61 JOIN EXISTING FENCE 15 11 12 13 14 16 17 18 13 14 3. 0 0 ' EG 11.96 FS 11.92TOW 15.33TOF 11.33 RELOCATE CONFLICTING PORTIONS OF EXISTING UTILITIES TC/FL 12.37FLOWLINE SEE DTL 4 ON THIS SHT (TYP) TC/FL 13.74 TC/FL 14.78 FS 14.28FS 13.85FS 13.92TOW 18.00TOF 12.00 EG 17.08 FS 14.57 FS 14.42 FS 14.42 EG 17.17 SLOPE TO DRAIN SLOPE TO DRAIN FS 17.2 HP BW/FS 14.92TOW 18.00TOF 12.00 EG 17.00 EG 14.63 FS 14.92TOW 16.00TOF 12.00 15 12 13 14 16 17 REMOVE CONFLICTING PORTIONSOF EXISTING UTILITIES EASEMENT C FL 13.89 FS 13.00 6.00' TYP FS 14.90 FS 14.50FS 14.42 FF 14.50FS 14.42 FF 14.44FS 14.38 FF 14.44 EG 13.14TC/FS 13.66FF 14.23 FS 14.00 FF 14.44FS 13.50 FS 13.46 FS 13.00 EG/FF 12.05 EG/FF 12.07 1.32% 5.60% 7 . 8 5 % 12 . 8 5 % 0.1 7 % 17 . 0 4 % 3 . 3 1 % 2.08% FS 14.92TOW 16.00TOW 18.00TOF 12.00 FS 13.59TOW 15.33TOF 11.33TOW 18.00TOF 12.00 FF 14.46FF 14.50 FF 14.24 OVERFLOW STRUCTURE JANSEN PRECAST MODEL D1121224-ATRIUM OR EQUAL TG 17.07 INV 12.57 2" PVC DRAIN PIPE BIORETENTION BASINL = 20.7 FTW = 1.7 FT - 3.7 FTSEE DTL 1 ON THIS SHT .75' 2%MAX EXISTING ACCESS RD EX I S T I N G AC C E S S R D SECURITY FENCE PER SAN DIEGO REGIONAL STD DWG M-61 JOINEXISTING FENCE FS 13.92 HP GB FS 13.34 FS 13.46 EG 11.51TC/FL 12.01 FS 13.00 FS 13.92 FS 13.92 FL 13.84 0.50%FL 13.79 HP GB 0. 5 0 % EG 11.4TC/FS 11.91 FL/GB 12.97 FF 14.50FS 14.00 5. 1 2 % FF 14.50FS 14.00 FF 14.44FS 13.94 TC 12.55 TC 12.57 TC/FS 12.75 FF 12.25 FF 12.24 TC/FS 12.73 TC/FS/FF 12.73 FS 14.06 0.50% 0. 5 0 % 2.75% 0.50% 2. 5 5 % FL 14.22 FS 14.90 FS 14.50 FL 14.65 FL 14.85 FS 14.92 EG 14.28 TC/FS 14.92 EG 14.42EG 13.42 EG 13.04TC/FS 13.54FF 13.55 EG 13.00TC/FS 13.50FF 13.51 FL 14.36 14 . 0 0 % 4. 5 0 % 11 . 4 4 % 8. 7 5 % 4.2 6 % 7.8 3 % 2. 9 5 % 2.2 3 % 8.71%16.79% 7. 5 1 % 0. 5 0 % 3.21 % 5 . 3 1 % 3 . 7 6 % 2.0 5 % 6.6 9 % 4. 3 9 % 8.75%17.02% 6 . 1 9 % EG 14.10 EG 15.56 7. 0 1 % 7.95% 7. 8 5 % FLOWLINE SEE DTL 3ON THIS SHT INV 12.57 BASIN ELEV 16.48 INV 12.45 0 . 2 0 % 0.55 % 0 . 5 8 % 2.48% EG 11.73 CURB OUTLET PER SAN DIEGOREGIONAL STD DWG D-27INV 11.53EG 11.4 TC 11.91 FF 13.92FS 13.50 6" MAX SURFACE PONDING 1' MIN WASHED AASHTO#57 STONE, FILTER COURSE WASHED AASHTO #7 STONE BIORETENTION AREA TOP OF BANK, EXISTGRADE 3" WELL-AGED , SHREDDED HARDWOOD MULCH BIORETENTION SOIL BIORETENTION AREA TOP OF BANK, EXIST GRADE 2" PER PLAN 18" EXISTING UNCOMPACTED SOIL 2" 1' 2" OVERFLOW STRUCTURE SLOPE VARIES PER PLAN 3:1 MA X 1:1 1 : 1 SLOPE VARIES PER PLAN 3" DRAIN PIPE 3:1 M A X TACK WELD NUT TO BOLT, TOUCH-UP WITH ZINC-RICH PAINT GALVANIZED PAD LOCK HASP TACK WELD TO STEEL PIPE (BEFORE GALVANIZING) AND BOLT TO CONCRETE ENCASEMENT, PAD LOCK SHALL HAVE A MIN OF 3" CLEARANCE FROM FINISHED SURFACE ~ 4" SCH 80 STL PIPE, WELD LIFTING HOOK ON TOP OF POST, PAINT WITH TWO COATS OF FRAZEE SCHOOL BUS YELLOW, NO. SBY 343 OR EQUAL, PLACE MAX 6' OC FINISHED GRADE 5" SCH 80 GALVANIZED STEEL PIPE WITH ENDCAP CLASS "B" CONCRETE ANCHOR BLOCK 0. 5 ' 4' 1.5' DIA 2. 5 ' NATIVE SOIL 3/4" CRUSHED ROCK S PER PLAN  S PER PLAN 6" FLOW WIDTH (TYP) 6" 6" EXIST CURB EXIST ROAD NATIVE SOIL FL, S PER PLAN S PER PLAN 6" 3/4" CRUSHED ROCK MARK DATE DESCRIPTION BY CHKD: DRWN: PROJ: DESN: www.tetratech.com 3/ 1 9 / 2 0 2 0 4 : 4 0 : 0 8 P M - O : \ P R O J E C T S \ I R V I N E \ 3 5 2 0 0 \ 2 0 0 - 3 5 2 0 0 - 1 9 0 0 1 \ C A D \ S H E E T F I L E S \ C - 2 1 0 1 E L E C B L D G G R A D E - P A V E . D W G - J O H N S O N , W I L L I E 1 A 2 3 4 5 6 7 B C D E F Bar measures 1 inch, otherwise drawing not to scale Co p y r i g h t : T e t r a T e c h 200-35200-19001 CARLSBAD DESALINATION PLANTINTAKE PUMP STATION PHASE 1 POSEIDON CHANNELSIDE 17885 Von Karman Ave, Suite 500Irvine, CA 92614 Tel: (949) 809-5000 Fax: (949) 809-5010 3/18/20 APPROVED FOR CONSTRUCTION C-2101ELECTRICAL BUILDING GRADING AND PAVING PLAN CR RJW SDT N 0 SCALE: 2.5'5'10' 1'' = 5' BIORETENTION SECTION1_SCALE: NTS REMOVABLE BOLLARD2_SCALE: NTS NOTES: FLOWLINE AT EXIST CURB4_SCALE: NTS FLOW LINE3_SCALE: NTS 1. OVERLAY SITE WHERE INDICATED WITH 6-INCHES OF 3/4" CRUSHED ROCK (SSPWC 200-1.2 OR SIMILAR) TO ACHIEVE DESIGNATED FINISHED SURFACE (FS) ELEVATIONS. FLOW LINES DEPICT INTENDED PATH OF SITE SURFACE DRAINAGE. 2. INSTALL LANDSCAPE FABRIC BETWEEN GROUND AND COMPACTEDNATIVE SOIL. BMP CONSTRUCTION AND INSPECTION NOTES: THE EOW WILL VERIFY THAT PERMANENT BMPS ARE CONSTRUCTED AND OPERATING IN COMPLIANCE WITH THE APPLICABLEREQUIREMENTS, PRIOR TO OCCUPANCY THE EOW MUST PROVIDE: 1. PHOTOGRAPHS OF THE INSTALLATION OF PERMANENT BMPSPRIOR TO CONSTRUCTION, DURING CONSTRUCTION, AND AT FINAL INSTALLATION. 2. A WET STAMPED LETTER VERIFYING THAT PERMANENT BMPS ARE CONSTRUCTED AND OPERATING PER THE REQUIREMENTS OF THE APPROVED PLANS. 3. PHOTOGRAPHS TO VERIFY THAT PERMANENT WATER QUALITYTREATMENT SIGNAGE HAS BEEN INSTALLED. PRIOR TO RELEASE OF SECURITIES, THE DEVELOPER IS RESPONSIBLE FOR ENSURING THE PERMANENT BMPS HAVE NOT BEEN REMOVED OR MODIFIED WITHOUT THE APPROVAL OF THE CITY ENGINEER.