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Home My WebLink AboutSDP 2024-0001; THE ROOSEVELT; STORM WATER QUALITY MANAGEMENT PLAN; 2025-11-18CITY OF CARLSBAD PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) FOR 2621 Roosevelt St. SDP 2024-0001 ENGINEER OF WORK: GR 2025-0005 IMP 2025-0008 DWG-551-7 & 551-7A MICHAEL D. SCHWEITZER, P.E. 59658 PREPARED FOR: Fabric Investments 2659 State St #100 Carlsbad, CA 92008 PREPARED BY: SWS Engineering, Inc. DATE: 11/18/2025 1635 Lake San Marcos Drive, Suite 200 San Marcos, California 92078 P 760.744.0011 TABLE OF CONTENTS Certification Page Project Vicinity Map FORM E-34 Storm Water Standard Questionnaire Site Information FORM E-36 Standard Project Requirement Checklist Summary of PDP Structural BMPs Attachment 1: Backup for PDP Pollutant Control BMPs Attachment 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: Categorization of Infiltration Feasibility Condition (when applicable) Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations Attachment 1f: Trash Capture BMP Requirements Attachment 3: Structural BMP Maintenance Thresholds and Actions Attachment 4: Single Sheet BMP (SSBMP) Exhibit CERTIFICATION PAGE Project Name: Roosevelt St. Project ID: SDP 2024-0001 I hereby declare that I am the Engineer in Responsible Charge of design of storm water BMPs for this project, and that I have exercised responsible charge over the design of the project as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with the requirements of the BMP Design Manual, which is based on the requirements of SDRWQCB Order No. R9-2013-0001 (MS4 Permit) or the current Order. I have read and understand that the City Engineer has adopted minimum requirements for managing urban runoff, including storm water, from land development activities, as described in the BMP Design Manual. I certify that this SWQMP has been completed to the best of my ability and accurately reflects the project being proposed and the applicable source control and site design BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the plan check review of this SWQMP by the City Engineer is confined to a review and does not relieve me, as the Engineer in Responsible Charge of design of storm water BMPs for this project, of my responsibilities for project design. _________________________ __ 96544__ Exp. 2-28-2027_ Engineer of Work's Signature, PE Number & Expiration Date Michael D. Schweitzer_______________________________________________________ Print Name SWS Engineering, Inc.______________________________________________________ Company _11//18/2025___________________________ Date PROJECT VICINITY MAP Page 1 of 4 REV E-34 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: ft 2 ( ) acres The total proposed newly created and/or replaced impervious area is: ft 2 ( ) 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: Development Services Land DevelopmentEngineering 1635 FaradayAvenue 442-339-2750 www.carlsbadca.gov STORM WATER STANDARDS QUESTIONNAIRE E-34 INSTRUCTIONS: Roosevelt St. 2621 Roosevelt St., Carlsbad, CA 203-101-23 20,687 0.47 18,948 0.43 E-34 Page 2 of 4 REV 0 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 0 * 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 bodiesdesignated 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. 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. E-34 Page 4 of 4 REV 0 STEP 4 TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP) ONLY Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)): YES NO Does the redevelopment project result in the creation or replacement of impervious surface in an amount of less than 50% of the surface area of the previously existing development? Complete the percent impervious calculation below: Existing impervious area (A) = sq. ft. Total proposed newly created or replaced impervious area (B) = sq. ft. Percent impervious area created or replaced (B/A)*100 = % If you answered “yes”, the structural BMPs required for PDP apply only to the creation or replacement of impervious surface and not the entire development. Go to step 5, complete the trash capture question. If you answered “no,” the structural BMP’s required for PDP apply to the entire development. Go to step 5, complete the trash capture question. STEP 5 TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS Complete the question below regarding your Project (SDRWQCB Order No. 2017-0077): YES NO Is the Project within any of the following Priority Land Use (PLU) categories? R-23 (15-23 du/ac), R-30 (23-30 du/ac), PI (Planned Industrial), CF (Community Facilities), GC (General Commercial), L (Local Shopping Center), R (Regional Commercial), V-B (Village-Barrio), VC (Visitor Commercial), O (Office), VC/OS (Visitor Commercial/Open Space), PI/O (Planned Industrial/Office), or Public Transportation Station If you answered “yes”, the ‘PROJECT’ is subject to TRASH CAPTURE REQUIREMENTS. Go to step 6, check the first box stating, “My project is subject to TRASH CAPTURE REQUIREMENTS …” and the second or third box as determined in step 3. If you answered “no”, Go to step 6, check the second or third box as determined in step 3. STEP 6 CHECK THE APPROPRIATE BOX(ES) AND COMPLETE APPLICANT INFORMATION My project is subject to TRASH CAPTURE REQUIREMENTS and must comply with TRASH CAPTURE REQUIREMENTS of the BMP Manual. I understand I must prepare a Storm Water Quality Management Plan (SWQMP). My project is a ‘STANDARD PROJECT’ OR EXEMPT from PDP and must only comply with ‘STANDARD PROJECT’ stormwater requirements of the BMP Manual. As part of these requirements, I will submit a “Standard Project Requirement Checklist Form E-36” and incorporate low impact development strategies throughout my project. If my project is subject to TRASH CAPTURE REQUIREMENTS, I will submit a TRASH CAPTURE Storm Water Quality Management Plan (TCSWQMP) per E-35A. My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must prepare a Storm Water Quality Management Plan (SWQMP) per E-35 template for submittal at time of application. Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations and exhibits to verify if ‘STANDARD PROJECT’ stormwater requirements apply. My project is NOT a ‘development project’ and is not subject to the requirements of the BMP Manual. Applicant Information and Signature Box Applicant Name: Applicant Title: Applicant Signature: Date: 14,541 18,948 130 Michael D. Schweitzer CEO/President SITE INFORMATION CHECKLIST Project Summary Information Project Name Roosevelt St. Project ID SDP2023-0019 Project Address 2621 Roosevelt ST. Carlsbad, CA 92008 Assessor's Parcel Number(s) (APN(s)) 203-101-2300 Project Watershed (Hydrologic Unit) Carlsbad 904 Parcel Area __0.46___ Acres (20,227___ Square Feet) Existing Impervious Area (subset of Parcel Area) __0.33___Acres (14,541_ Square Feet) Area to be disturbed by the project (Project Area) __0.47__ Acres (20,687____ Square Feet) Project Proposed Impervious Area (subset of Project Area) _0.43 _Acres (18,948___ Square Feet) Project Proposed Pervious Area (subset of Project Area) __0.039__ Acres (1,739_ _ Square Feet) Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the Project. This may be less than the Parcel Area. *Includes Street Improvement Impervious and replaced impervious 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 existing project site is developed multiple and single- family homes Existing Land Cover Includes (select all that apply): Vegetative Cover Non-Vegetated Pervious Areas Impervious Areas Description / Additional Information: existing landscape, buildings, parking lot and driveways, 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 Existing Natural Hydrologic Features (select all that apply): Watercourses Seeps Springs Wetlands None Description / Additional Information: Description of Existing Site Topography and Drainage [How is storm water runoff conveyed from the site? At a minimum, this description should answer (1) whether existing drainage conveyance is natural or urban; (2) describe existing constructed storm water conveyance systems, if applicable; and (3) is runoff from offsite conveyed through the site? if so, describe]: The existing site is an existing office building and parking lot that all the runoff surface flow in easterly direction discharging into Roosevelt St. and then storm water enters existing curb inlet south of the project. The storm water is then conveyed to an existing 30” RCP storm drain constructed per city of Carlsbad drainage 456-4J. The topography of the site is essentially a flat plain with a slight slope to the east. There is no storm drain system on the site. The site ultimately discharges into Buena Vista Lagoon within the Carlsbad Watershed. Description of Proposed Site Development and Drainage Patterns Description / Proposed Land Use and/or Activities: The proposed project is a redevelopment of an existing developed office building located on Roosevelt St south of Laguna Dr. and east of State St within the city of Carlsbad, CA. The redevelopment of the site will consist of mixed used (residential, Office, retail), underground Parking, driveways, associated utilities, treatment system. Project located on V-B per General plan Land Use Designation. The total site development area is ±0.46 ac. List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features): The site impervious feature will be building footprint, driveway, sidewalk, pavers List/describe proposed pervious features of the project (e.g., landscape areas): The site pervious features will be multiple planters throughout the site and biofiltration basin Does the project include grading and changes to site topography? Yes No Description / Additional Information: The proposed site will be entirely graded Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)? Yes No Description / Additional Information: The site will be entirely graded and storm drain system constructed to discharge the onsite runoff from treatment system into streets as it does in existing condition. 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 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): the proposed site will discharge offsite into the existing storm drain system located on Rosservret St. The site ultimately discharges into Buena Vista Lagoon with the Carlsbad Watershed and finally into Pacific Ocean (La Jolla to San Onofre). List any 303(d) impaired water bodies within the path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water bodies: 303(d) Impaired Water Body Pollutant(s)/Stressor(s) TMDLs Buena Vista Lagoon Bacteria and other Microbes, Nitrogen and/or Phosphorus, Sediment, Total Toxic Chemicals Indicator Bacteria Pacífica Ocean (La Jolla to San Onofre) Trash Identification of Project Site Pollutants Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see BMP Design Manual Appendix B.6): Pollutant Not Applicable to the Project Site Anticipated from the Project Site Also a Receiving Water Pollutant of Concern Sediment  (X) Nutrients  (X) Heavy Metals Organic Compounds Trash & Debris  (X)  Oxygen Demanding Substances  (P) Oil & Grease  (P) Bacteria & Viruses  (P) Pesticides  (X) X = Anticipated P = Potential 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 one-year, one-hour storm event or equivalent storm drain system, and 2) the trash capture BMP captures trash equal or greater to 5mm. Description / Discussion of Trash Capture BMPs: Insertion of Bio Clean Catch Basin Inlet Filer (BIO-GRATE-FULL- 12-12-12) to filter the runoff draining into catch basin located in the Biofiltration basin prior to discharging offsite via 12” storm drain system. 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 discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean. No, the project will discharge runoff directly to conveyance channels whose bed and bank are concrete-lined all the way from the point of discharge to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean. No, the project will discharge runoff directly to an area identified as appropriate for an exemption by the WMAA for the watershed in which the project resides. Description / Additional Information (to be provided if a 'No' answer has been selected above): Exempt per “Hydromodification Exemption map” (see HMP Exemption Map for reference) Study by Wayne Chang, Dated 9/20/15 Critical Coarse Sediment Yield Areas* *This Section only required if hydromodification management requirements apply Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas exist within the project drainage boundaries? 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 Section 6.2 of the BMP Design Manual been performed? 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite 6.2.2 Downstream Systems Sensitivity to Coarse Sediment 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite 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 6.2.4 and 6.2.5 as applicable, and the areas are identified on the SWQMP Exhibit. Discussion / Additional Information: N/A Flow Control for Post-Project Runoff* N/A *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) Other Site Requirements and Constraints When applicable, list other site requirements or constraints that will influence storm water management design, such as zoning requirements including setbacks and open space, or City codes governing minimum street width, sidewalk construction, allowable pavement types, and drainage requirements. Optional Additional Information or Continuation of Previous Sections As Needed This space provided for additional information or continuation of information from previous sections as needed. E-36 Page 1 of 4 Revised 0 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 The Roosevelt SDP2024-0001 DWG-551-7 & 551-7A ■■ ■ E-36 Page 2 of 4 Revised 0 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 There are DG walkway area proposed on the SW of the site that very end portion of the parking installs drain into. Roof drain into BF via three storm drain systems shown on the DMA map. Please see the landscaping plan ■■ E-36 Page 3 of 4 Revised 0 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: x Storm drain inlets and catch basins …are not proposed will be labeled with stenciling or signage to discourage dumping (SC-F) x Interior work surfaces, floor drains & sumps … are not proposed will not discharge directly or indirectly to the MS4 or receiving waters x Drain lines (e.g. air conditioning, boiler, etc.) … are not proposed will not discharge directly or indirectly to the MS4 or receiving waters x 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): Inlets: SWPPP, inlets marked with "No Dumping! Flows to Lagoon" or similar, regular maintenance Pest control: Building design that discourages pest entry, 1PM plan Pesticide use: Landscaping designed/plant selection to minimize need for fertilizers/pesticides Refuse areas: Grading to minimize runoff, provide adequate# of receptacles, regular inspection/repair/trash pick-up Fire sprinkler test water: Drain to sanitary sewer Hardscape/parking lots: Regular sweeping, debris collection to prevent entry into the storm drain system, cleaning agents discharged into sanitary sewer E-36 Page 4 of 4 Revised 0 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: 9/30/25 Michael D. Schweitzer SUMMARY OF PDP STRUCTURAL BMPS PDP Structural BMPs All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control must be based on the selection process described in Chapter 5. PDPs subject to hydromodification management requirements must also implement structural BMPs for flow control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both storm water pollutant control and flow control for hydromodification management can be achieved within the same structural BMP(s). PDP structural BMPs must be verified by the City at the completion of construction. This may include requiring the project owner or project owner's representative to certify construction of the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must be maintained into perpetuity, and the City must confirm the maintenance (see Section 7 of the BMP Design Manual). Use this form to provide narrative description of the general strategy for structural BMP implementation at the project site in the box below. Then complete the PDP structural BMP summary information sheet for each structural BMP within the project (copy the BMP summary information page as many times as needed to provide summary information for each individual structural BMP). Describe the general strategy for structural BMP implementation at the site. This information must describe how the steps for selecting and designing storm water pollutant control BMPs presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated together or separate. The project tributary area were delineated and used to calculated the Design Capture Volume (DCV) The proposed site will incorporate a biofiltration basin in the northeast portion of the site. All the roof and surface drains from DMA-1, will sheet flow and via series of catch basins from the project south and west side to the northeast into biofiltration basin for treatment. Small frontage portion of the site (DMA-2) and DMA-3 that cannot be captured and treated, will be swapped with the offsite frontage street (DMA-5, front of DMA-4) that drains into proposed tree-well so that can be treated along with the site improved frontage sidewalk (DMA-4). The BMP will be used to meet water quality/pollutant control requirements only. Hydromofiication and detention are not required. Per Geotechnical report (Storm Water Management investigation) done by Geocon Inc. dated May 9, 2023, Full Infiltration” should be considered infeasible. The site can be classified as “Partial Infiltration” condition due to the rates ranging between 0.05 to 0.5 inches per hour; however, the site should be considered a “No Infiltration” condition due to the presence of the soil that possesses a potential for hydrocollapse in the Old Paralic Deposits. Harvest and use is considered infeasible (see Attachment 1.C, Form I-7 for calculations). [Continued from previous page – This page is reserved for continuation of description of general strategy for structural BMP implementation at the site.] Structural BMP Summary Information [Copy this page as needed to provide information for each individual proposed structural BMP] Structural BMP ID No. IMP-1 DWG: 551-7 & 551-7A Sheet No. _3, 4, 7________ 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 onsite 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) 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): Biofiltration basin is proposed for onsite runoff treatment (DMA-1). Structural BMP Summary Information [Copy this page as needed to provide information for each individual proposed structural BMP] Structural BMP ID No. IMP-2 DWG: 551-7 & 551-7A Sheet No. _3, 4, 7________ 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 onsite 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) 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): Tree-Well is proposed to treat the site frontage sidewalk (DMA-4) as well as the swapped offsite frontage street (DMA-5, front of DMA-4) that drains into the proposed tree-well in exchange with the DMA-2 and DMA-3 that cannot be captured for treatment. ATTACHMENT 1 BACKUP FOR PDP POLLUTANT CONTROL BMPS This is the cover sheet for Attachment 1. Check which Items are Included behind this cover sheet: Attachment Sequence Contents Checklist Attachment 1a DMA Exhibit (Required) See DMA Exhibit Checklist on the back of this Attachment cover sheet. (24”x36” 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 I-7, Harvest and Use Feasibility Screening Checklist (Required unless the entire project will use infiltration BMPs) Refer to Appendix B.3-1 of the BMP Design Manual to complete Form I-7. Included Not included because the entire project will use infiltration BMPs Attachment 1d Table D.1-1 Infiltration Feasibility Analysis (Required unless the project will use harvest and use BMPs) Refer to Appendices C and D of the BMP Design Manual to complete Table D.1-1.  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 and E of the BMP Design Manual for structural pollutant control 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  Not included because the entire project is not subject to trash capture requirements  Use this checklist to ensure the required information has been included on the DMA Exhibit: The DMA Exhibit must identify: Underlying hydrologic soil group Approximate depth to groundwater Existing natural hydrologic features (watercourses, seeps, springs, wetlands) Critical coarse sediment yield areas to be protected (if present) Existing topography and impervious areas Existing and proposed site drainage network and connections to drainage offsite Proposed grading Proposed impervious features Proposed design features and surface treatments used to minimize imperviousness Drainage management area (DMA) boundaries, DMA ID numbers, and DMA areas (square footage or acreage), and DMA type (i.e., drains to BMP, self-retaining, or self-mitigating) Structural BMPs (identify location and type of BMP) ATTACHMENT 1a S S W W X X X X X X X X X X X X X X X X 4 3 43 42 42 42 42 41 4 1 41 41 4 0 40 40 39 39 3 9 39 39 39 38 38 38 38 43 41 DMA-4 993 SF TREATMENT AREA: 467 SF IM P - 2 ( T R E E - W E L L ) 9' x 1 0 ' w / 1 5 ' C A N O P Y DMA-5 (SWAP) 1,422 SF DMA-2: 778 SF IMPERVIOUS: 700 SF (SWAP) DMA-1 18,194 SF ALL THE ROOF TOP WILL DRAIN INTO BIOFILTRATOIN PRIOR LEAVING THE SITE DMA-3 IMPERVIOUS:722 SF (SWAP) EX. CURB INLET EX. CURB INLET TRASH CAPTURE: BIO-GRATE-FULL-12-12-12 SDSD SD IMP-1: BIOFILTRATION (BF-1) SD SD LEGEND SAN T A F E BL V D LA COSTA AVE RA N C H O R E A L CANNON PALOMAR C A R L S B A D A V I A R A PK W Y . AIRPO R T I N T E R S T A T E HIGHWAY 78 RD. EL CA M I N O ROA D ROAD ALGA ROAD SCALE NOT TO C O L L E G E B L . CO L L E G E BLV D . 1 OF 2 DATE: Nov 18, 25 11:13am by:massy.fatini FILE:C:\Users\massy.fatini\DC\ACCDocs\SWS Engineering\2023\Project Files\23-143\PROD\Reports\WQMP\23-143_DMA MAP.dwg 1635 Lake San Marcos Drive, Suite 200 San Marcos, CA 92078 P: 760-744-0011 F: 760-744-0046 DMA MAP ROOSEVELT ST FOR SD PLAN NTS DATE: Nov 18, 25 11:15am by:massy.fatini FILE:C:\Users\massy.fatini\DC\ACCDocs\SWS Engineering\2023\Project Files\23-143\PROD\Reports\WQMP\23-143_DMA MAP.dwg 1635 Lake San Marcos Drive, Suite 200 San Marcos, CA 92078 P: 760-744-0011 F: 760-744-0046 DMA MAP ROOSEVELT ST FOR 2 OF 2 ATTACHMENT 1b Us e t h e f o l l o w i n g t a b l e f o r T a b u l a r D M A S u m m a r y '0$LVRIIVLWHDUHDWKDWGRHVQRWQHHGWREHWUHDWHGEXWZLOOEHWUHDWHGLQH[FKDQJHVZDSZLWK'0$ '0$ RQVLWHDUHDWKDWQHHGVWREHWUHDWHGEXWFDQQRWEHFDSWXUHGIRUWUHDWPHQW 6XPPDU\RI'0$V DMA-1 DMA-4&5 DMA-2 DMA-3 0.42 0.055 0.018 0.016 0.38 0.052 0.016 0.016 92 94 90 100 B B B B 0.83 0.86 0.82 0.9 0.48 734 - - - IMP-1 IMP-2 - - Biofiltration TREE-WELL SWAPPED SWAPPED - - - - 0.48 0.48 0.46 93 B 0.82 -0.48 - ATTACHMENT 1c 1.Is there a demand for harvested water ( check all that apply) at the project site that is reliably present duringthe wet season?D Toilet and urinal flushingD Landscape irrigationD 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 providedin Section B.3.2.3.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 c:::> Harvest and use appears to be feasible. Conduct more detailed evaluation and sizing calculations to confirm that DCV can be used at an adequate rate to meet drawdown criteria. 36.Is the 36 hour demand greater than0.25DCV but less than the full DCV?□Yes / □No c:::> Harvest and use may be feasible. Conduct more detailed evaluation and sizing calculations to determine feasibility. Harvest and use may only be able to be used for a portion of the site, or ( optionally) the storage may need to be upsized to meet long term capture targets while draining in longer than 36 hours. Is harvest and use feasible based on further evaluation? D Yes, refer to Appendix E to select and size harvest and use BMPs. □No, select alternate BMPs.1-26 3c. Is the 36 hour demand less than 0.25DCV? □Yes,().Harvest and use is considered to be infeasible. February 2016 Form I-7 ATTACHMENT 1d STORM WATER MANAGEMENT INVESTIGATION 2621 ROOSEVELT STREET CARLSBAD, CALIFORNIA PREPARED FOR MAY 9, 2023 PROJECT NO. G3112-52-01 Project No. G3112-52-01 May 9, 2023 Fabric Investments 2727 Roosevelt Street, Suite B Carlsbad, California 92008 Attention: Mr. Scott Heath, VP Development Subject: STORM WATER MANAGEMENT INVESTIGATION 2621 ROOSEVELT STREET CARLSBAD, CALIFORNIA Reference: Geotechnical Investigation, 2621 Roosevelt Street, Carlsbad, California, prepared by Geocon Incorporated, dated May 9, 2023 (Project No. G3112-52-01). Dear Mr. Heath: In accordance with your request, we herein submit the results of our storm water management investigation for the property located at 2621 Roosevelt Street in the City of Carlsbad, California SITE AND PROJECT DESCRIPTION The property currently consists of a 2-story commercial building with accommodating utilities, landscaping and surface parking consisting of concrete pavement. A landscape area is located west of the building that be accessed from a gate on the south from the parking lot. The site is located within the Carlsbad Village neighborhood and accessed by Roosevelt Street. The property is west of Roosevelt Street, north of a mobile home site, west of a car wash, and south of a parking lot. Existing grades are relatively flat with elevations of approximately 40 to 42 feet Mean Sea Level (MSL) across the site. The Existing Site Plan shows the current site conditions. Geocon Project No. G3112-52-01 - 2 - May 9, 2023 We prepared the referenced geotechnical investigation report for the site and proposed development. Our field investigation consisted of advancing 2 exploratory borings (Borings B-1 and B-2) to a maximum depth of about 20 feet and performing 2 infiltration tests. During our investigation, we encountered one surficial soil unit (consisting of undocumented fill) and two formational unit (consisting of Old Paralic Deposits and Santiago Formation). We encountered undocumented fill in our borings to depths up to about 2 feet overlying the Old Paralic Deposits. The occurrence, distribution, and description of each unit encountered are shown on the Geologic Map, Figure 1, and on the boring logs in Appendix A of the referenced report. STORM WATER MANAGEMENT INVESTIGATION We understand storm water management devices will be used in accordance with the 2021 City of Carlsbad BMP Design Manual. If not properly constructed, there is a potential for distress to improvements and properties located hydrologically down gradient or adjacent to these devices. Factors such as the amount of water to be detained, its residence time, and soil permeability have an important effect on seepage transmission and the potential adverse impacts that may occur if the storm water management features are not properly designed and constructed. We have not performed a hydrogeological study at the site. If infiltration of storm water runoff occurs, downstream properties may be subjected to seeps, springs, slope instability, raised groundwater, movement of foundations and slabs, or other undesirable impacts as a result of water infiltration. Geocon Project No. G3112-52-01 - 3 - May 9, 2023 Hydrologic Soil Group The United States Department of Agriculture (USDA), Natural Resources Conservation Services, possesses general information regarding the existing soil conditions for areas within the United States. The USDA website also provides the Hydrologic Soil Group. Table 1 presents the descriptions of the hydrologic soil groups. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. In addition, the USDA website also provides an estimated saturated hydraulic conductivity for the existing soil. TABLE 1 HYDROLOGIC SOIL GROUP DEFINITIONS Soil Group Soil Group Definition A Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. B Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. C Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. D Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. Table 2 presents the information from the USDA website for the subject property. The Hydrologic Soil Group Map presents output from the USDA website showing the limits of the soil units. TABLE 2 USDA WEB SOIL SURVEY – HYDROLOGIC SOIL GROUP* Map Unit Name Map Unit Symbol Approximate Percentage of Property Hydrologic Soil Group kSAT of Most Limiting Layer (Inches/ Hour) Marina loamy coarse sand, 2 to 9 percent slopes MlC 100 B 0.57 – 1.98 *The areas of the property that possess fill materials should be considered to possess a Hydrologic Soil Group D. Geocon Project No. G3112-52-01 - 4 - May 9, 2023 Hydrologic Soil Group Map In Situ Testing We performed 2 constant-head infiltration tests using the Aardvark permeameter at the locations shown on the Geologic Map, Figure 2. Table 3 presents the results of the infiltration tests. The field data sheets are attached herein. We applied a feasibility factor of safety of 2.0 to our estimated infiltration rates. The designer of storm water devices should apply an appropriate factor of safety, where necessary. Soil infiltration rates from in-situ tests can vary significantly from one location to another due to the heterogeneous characteristics inherent to most soil. TABLE 3 INFILTRATION TEST RESULTS Test No. Geologic Unit Test Depth (feet, below grade) Field-Saturated Hydraulic Conductivity/Infiltration Rate, ksat (inch/hour) Worksheet Infiltration Rate1 (inch/hour) P-1 Qop 6 0.618 0.309 P-2 Qop 5 0.287 0.143 Average 0.453 0.226 1 Using a Factor of Safety of 2. Infiltration categories include full infiltration, partial infiltration and no infiltration. Table 4 presents the commonly accepted definitions of the potential infiltration categories based on the infiltration rates. Geocon Project No. G3112-52-01 - 5 - May 9, 2023 TABLE 4 INFILTRATION CATEGORIES Infiltration Category Field Infiltration Rate, I (Inches/Hour) Factored Infiltration Rate1, I (Inches/Hour) Full Infiltration I > 1.0 I > 0.5 Partial Infiltration 0.10 < I < 1.0 0.05 < I < 0.5 No Infiltration (Infeasible) I < 0.10 I < 0.05 1 Using a Factor of Safety of 2. The test results indicate the approximate infiltration rates range from approximately 0.618 to 0.287 inches per hour (0.309 to 0.143 inches per hour with an applied factor of safety of 2). The average infiltration rate with an applied factor of safety of 2 is 0.226 inches per hour. “Full Infiltration” should be considered infeasible; however, “Partial Infiltration” can be considered feasible at the site based on the average infiltration rate is between 0.05 and 0.5 inches per hour. GEOTECHNICAL CONSIDERATIONS Groundwater Elevations We encountered perched groundwater/seepage during our investigation at depths ranging from approximately 11 to 15 feet below the existing ground surface (approximate elevations ranging from approximately 30 to 27 feet MSL). We expect permanent groundwater is approximately 40 feet below the existing ground surface. New or Existing Utilities Utilities are present on the existing property and within the existing adjacent Roosevelt Street. Full or partial infiltration should not be allowed in the areas of the utilities to help prevent potential damage/distress to improvements. Mitigation measures to prevent water from infiltrating the utilities consist of setbacks, installing cutoff walls around the utilities and installing subdrains and/or installing liners. Existing Structures Existing structures exist to the north and south and west of the site. Water should not be allowed to infiltrate in areas where it could affect the existing and neighboring properties and existing and adjacent structures, improvements and roadways. Mitigation for existing structures consist of not allowing water infiltration within a 1:1 plane from existing foundations and extending the infiltration areas at least 10 feet from the existing foundations and into formational materials. Geocon Project No. G3112-52-01 - 6 - May 9, 2023 Soil or Groundwater Contamination We are unaware of contaminated soil on the property. Therefore, infiltration associated with this risk is considered feasible. Hydrocollapse Based on laboratory testing the Old Paralic Deposits has the potential for hydrocollapse. Therefore, full or partial infiltration should be considered infeasible. CONCLUSIONS AND RECOMMENDATIONS Storm Water Evaluation Narrative The site is underlain by approximately 1 to 2 feet of undocumented fill across the site and supports the existing improvements. In our experience, fill does not possess infiltration rates appropriate with infiltration. Therefore, infiltration is considered infeasible within the undocumented fill and we performed our infiltration tests in the relatively shallow Old Paralic Deposits. The formational Old Paralic Deposits underlie the undocumented as shallow as 2 to 3 feet deep and extending to approximately 15 to 17 feet below existing grade. We performed 2 infiltration tests within the Old Paralic Deposits and the results indicate an infiltration rate of approximately 0.226 inches per hour. The Santiago Formation exists below the Old Paralic Deposits. We did not perform infiltration testing within the Santiago Formation due to the depth of the formation. It would be unreasonable and costly to install storm water devices at depths exceeding approximately 15 feet at the site. We encountered perched groundwater/seepage during our investigation at depths ranging from approximately 11 and 15 feet below the existing ground surface. We expect permanent groundwater exist approximately 40 feet below existing grade. We expect the bottom of planned storm water infiltration devices will extend to depths of 2 feet or greater below the existing ground surface at the site. Storm Water Evaluation Conclusion Based on the results of our infiltration tests performed within the existing formational materials (approximately 0.226 inches per hour), and the depth of groundwater relative to the bottom of planned storm water devices, we opine “Full Infiltration” on the property is considered infeasible. The site can be classified as “Partial Infiltration” condition due to the rates ranging between 0.05 to 0.5 inches per hour; however, the site should be considered a “No Infiltration” condition due to the presence of the soil that possesses a potential for hydrocollapse in the Old Paralic Deposits. Geocon Project No. G3112-52-01 - 7 - May 9, 2023 Storm Water Management Devices Liners and subdrains should be incorporated into the design and construction of the planned storm water devices. The liners should be impermeable (e.g. High-density polyethylene, HDPE, with a thickness of about 30 mil or equivalent Polyvinyl Chloride, PVC) to prevent water migration. The subdrains should be perforated within the liner area, installed at the base and above the liner, be at least 3 inches in diameter and consist of Schedule 40 PVC pipe. The subdrains outside of the liner should consist of solid pipe. The penetration of the liners at the subdrains should be properly waterproofed. The subdrains should be connected to a proper outlet. The devices should also be installed in accordance with the manufacturer’s recommendations. Storm Water Standard Worksheets We evaluated the proposed project with respect to the infiltration restrictions contained in Table D.1-1 in Appendix D of the City of Carlsbad BMP Design Manual (see Table 5). TABLE 5 CONSIDERATIONS FOR GEOTECHNICAL ANALYSIS OF INFILTRATION RESTRICTIONS (TABLE D.1-1 OF APPENDIX D) Restriction Element Is Element Applicable? (Yes/No) Mandatory Considerations BMP is within 100’ of Contaminated Soils No BMP is within 100’ of Industrial Activities Lacking Source Control No BMP is within 100’ of Well/Groundwater Basin No BMP is within 50’ of Septic Tanks/Leach Fields No BMP is within 10’ of Structures/Tanks/Walls No BMP is within 10’ of Sewer Utilities No BMP is within 10’ of Groundwater Table No BMP is within Hydric Soils No BMP is within Highly Liquefiable Soils and has Connectivity to Structures No BMP is within 1.5 Times the Height of Adjacent Steep Slopes (≥25%)No City Staff has Assigned “Restricted” Infiltration Category No Optional Considerations BMP is within Predominantly Type D Soil No BMP is within 10’ of Property Line No BMP is within Fill Depths of ≥5’ (Existing or Proposed)No BMP is within 10’ of Underground Utilities No BMP is within 250’ of Ephemeral Stream No Other (Provide detailed geotechnical support) –Hydrocollapse (See discussion herein)Yes Result Based on examination of the best available information, I have not identified any restrictions above. Based on examination of the best available information, I have identified one or more restrictions above. X Restricted Geocon Project No. G3112-52-01 - 8 - May 9, 2023 The BMP manual also has a worksheet (Table D.2-4 of Appendix D) that helps the project civil engineer estimate the factor of safety based on several factors. Table 6 describes the suitability assessment input parameters related to the geotechnical engineering aspects for the factor of safety determination. TABLE 6 GUIDANCE FOR DETERMINING INDIVIDUAL FACTOR VALUES – PART A (TABLE D.2-4 OF APPENDIX D) Consideration High Concern – 3 Points Medium Concern – 2 Points Low Concern – 1 Point Infiltration Test Method Any At least 2 tests of any kind within 50’ of BMP At least 4 tests within BMP footprint, OR Large/Small Scale Pilot Infiltration Testing over at least 5% of BMP footprint. Soil Texture Class Unknown, Silty, or Clayey Loamy Granular/Slightly Loamy Site Variability Unknown or High Moderately Homogenous Significantly Homogenous Depth to Groundwater/ Obstruction <5’ below BMP 5-15’ below BMP >15’ below BMP Table 7 presents the estimated safety factor values for the evaluation of the factor of safety. This table only presents the suitability assessment safety factor (Part A) of the worksheet. The project civil engineer should evaluate the safety factor for design (Part B) and use the combined safety factor for the design infiltration rate. TABLE 7 DETERMINATION OF SAFETY FACTOR (TABLE D.2-3 OF APPENDIX D) Consideration Assigned Weight (w) Factor Value (v) Product (p = w x v) Suitability Assessment(A) Infiltration Testing Method 0.25 2 0.50 Soil Texture Class 0.25 2 0.50 Site Variability 0.25 3 0.75 Depth to Groundwater/Obstruction 0.25 1 0.25 Suitability Assessment Safety Factor, SA = p 2.0 Design (B) Pretreatment * Refer to Table D.2-4 * Resiliency * * Compaction * * Design Safety Factor, SB = p * Safety Factor, S = SA x SB(Must be always greater than or equal to 2)* *The civil engineer should evaluate the “Design (B)” factors and the Safety Factor, S. Geocon Project No. G3112-52-01 - 9 - May 9, 2023 Table 8 presents the elements for determining the design infiltration rate (Table D.2-1 of Appendix D). The civil engineer should evaluate the Safety Factor, S and Design Infiltration Rate. We also included herein the original I-8 Form from previous submittals for consistency with the current submittal process. TABLE 8 ELEMENTS FOR DETERMINATION OF DESIGN INFILTRATION RATES Item Value Initial Infiltration Rate Identify per Section D.2.1 0.453 Inches/Hour Corrected Infiltration Rate Identify per Section D.2.2 0.226 Inches/Hour Safety Factor Identify per Section D.2.3 * Design Infiltration Rate Corrected Infiltration Rate/Safety Factor *Inches/Hour *The civil engineer should evaluate the Safety Factor and Design Infiltration Rate. If you have any questions regarding this correspondence, or if we may be of further service, please contact the undersigned at your convenience. Very truly yours, GEOCON INCORPORATED Nikolas Garcia Staff Engineer Shawn Foy Weedon GE 2714 NG:SFW:arm (e-mail) Addressee 1 1' B-1 B-2 P-1 P-2 Qudf/ / GEOLOGIC MAP 1 2621 ROOSEVELT STREET CARLSBAD, CALIFORNIA 6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974 PHONE 858 558-6900 - FAX 858 558-6159PROJECT NO. G3112 - 52 - 01 DATE 05 - 09 - 2023FIGURE GEOTECHNICAL ENVIRONMENTAL MATERIALS Plotted:05/08/2023 2:26PM | By:RUBEN AGUILAR | File Location:Y:\PROJECTS\G3112-52-01 2621 Roosevelt Street\SHEETS\G3112-52-01 GeoMap.dwg B-2 GEOCON LEGEND ........APPROX. LOCATION OF EXPLORATORY BORING ........APPROX. LOCATION OF INFILTRATION TEST ........APPROX. LOCATION OF GEOLOGIC CROSS-SECTION 1 1' ........UNDOCUMENTED FILLQudf ........OLD PARALIC DEPOSITS (Dotted Where Buried)Qop P-2 ........SANTIAGO FORMATION (Dotted Where Buried)Tsa 6" ASPHALT CONCRETE UNDOCUMENTED FILL (Qudf) Medium dense, moist, reddish brown, Silty, fine to medium SAND OLD PARALIC DEPOSITS (Qop) Medium dense, damp to moist, reddish to yellowish brown, Silty, fine to coarse SANDSTONE -Difficult drilling -Becomes moist to wet -Perched groundwater between 11-13 feet, becomes pale brown -Transition in sample SANTIAGO FORMATION (Tsa) Very dense, moist, light gray to white, Silty, fine to coarse SANDSTONE BORING TERMINATED AT 20 FEET Perched groundwater at 11 feet 100.2 117.4 109.6 117.8 119.6 7.9 8.1 8.8 13.6 11.9 B1-1 B1-2 B1-3 B1-4 B1-5 30 30 43 70/11" 90/11" SM SM SM ... DISTURBED OR BAG SAMPLE GEOCON DEPTH IN FEET 0 2 4 6 8 10 12 14 16 18 20 Figure A-1, Log of Boring B 1, Page 1 of 1 DR Y D E N S I T Y (P . C . F . ) ... DRIVE SAMPLE (UNDISTURBED) MOBILE DRILL B-51 PE N E T R A T I O N RE S I S T A N C E (B L O W S / F T . ) BORING B 1 ... CHUNK SAMPLE DATE COMPLETED ... SAMPLING UNSUCCESSFUL SOIL CLASS (USCS) GR O U N D W A T E R N. GARCIA CO N T E N T ( % ) SAMPLE NO.04-20-2023 SAMPLE SYMBOLS MO I S T U R E BY:EQUIPMENT ELEV. (MSL.)41' G3112-52-01.GPJ MATERIAL DESCRIPTION LI T H O L O G Y ... STANDARD PENETRATION TEST ... WATER TABLE OR ... SEEPAGE NOTE: PROJECT NO. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. G3112-52-01 6" ASPHALT CONCRETE UNDOCUMENTED FILL (Qudf) Medium dense, moist, dark reddish brown, Silty, fine to coarse SAND OLD PARALIC DEPOSITS (Qop) Medium dense, moist, reddish to yellowish brown, Silty, fine to coarse SANDSTONE -Perched groundwater -Becomes dense, wet SANTIAGO FORMATION (Tsa) Very dense, moist, light gray to white, Silty, fine to coarse SANDSTONE BORING TERMINATED AT 20 FEET Perched groundwater at 15 feet 112.5 110.8 121.9 120.1 7.2 8.4 15.0 11.7 B2-1 B2-2 B2-3 B2-4 B2-5 26 43 49 50/9" SM SM SM ... DISTURBED OR BAG SAMPLE GEOCON DEPTH IN FEET 0 2 4 6 8 10 12 14 16 18 20 Figure A-2, Log of Boring B 2, Page 1 of 1 DR Y D E N S I T Y (P . C . F . ) ... DRIVE SAMPLE (UNDISTURBED) MOBILE DRILL B-51 PE N E T R A T I O N RE S I S T A N C E (B L O W S / F T . ) BORING B 2 ... CHUNK SAMPLE DATE COMPLETED ... SAMPLING UNSUCCESSFUL SOIL CLASS (USCS) GR O U N D W A T E R N. GARCIA CO N T E N T ( % ) SAMPLE NO.04-20-2023 SAMPLE SYMBOLS MO I S T U R E BY:EQUIPMENT ELEV. (MSL.)42' G3112-52-01.GPJ MATERIAL DESCRIPTION LI T H O L O G Y ... STANDARD PENETRATION TEST ... WATER TABLE OR ... SEEPAGE NOTE: PROJECT NO. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. G3112-52-01 6" ASPHALT CONCRETE UNDOCUMENTED FILL (Qudf) Medium dense, moist, reddish brown, Silty, fine to coarse SAND OLD PARALIC DEPOSITS (Qop) Medium dense, damp to moist, reddish to yellowish brown, Silty, fine to coarse SANDSTONE BORING TERMINATED AT 6 FEET No groundwater encountered SM SM ... DISTURBED OR BAG SAMPLE GEOCON DEPTH IN FEET 0 2 4 6 Figure A-3, Log of Boring P 1, Page 1 of 1 DR Y D E N S I T Y (P . C . F . ) ... DRIVE SAMPLE (UNDISTURBED) MOBILE DRILL B-51 PE N E T R A T I O N RE S I S T A N C E (B L O W S / F T . ) BORING P 1 ... CHUNK SAMPLE DATE COMPLETED ... SAMPLING UNSUCCESSFUL SOIL CLASS (USCS) GR O U N D W A T E R N. GARCIA CO N T E N T ( % ) SAMPLE NO.04-20-2023 SAMPLE SYMBOLS MO I S T U R E BY:EQUIPMENT ELEV. (MSL.)41' G3112-52-01.GPJ MATERIAL DESCRIPTION LI T H O L O G Y ... STANDARD PENETRATION TEST ... WATER TABLE OR ... SEEPAGE NOTE: PROJECT NO. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. G3112-52-01 6" ASPHALT CONCRETE UNDOCUMENTED FILL (Qudf) Medium dense, moist, reddish brown, Silty, fine to coarse SAND OLD PARALIC DEPOSITS (Qop) Medium dense, reddish to yellowish brown, Silty, fine to coarse SANDSTONE BORING TERMINATED AT 5 FEET No groundwater encountered SM SM ... DISTURBED OR BAG SAMPLE GEOCON DEPTH IN FEET 0 2 4 Figure A-4, Log of Boring P 2, Page 1 of 1 DR Y D E N S I T Y (P . C . F . ) ... DRIVE SAMPLE (UNDISTURBED) MOBILE DRILL B-51 PE N E T R A T I O N RE S I S T A N C E (B L O W S / F T . ) BORING P 2 ... CHUNK SAMPLE DATE COMPLETED ... SAMPLING UNSUCCESSFUL SOIL CLASS (USCS) GR O U N D W A T E R N. GARCIA CO N T E N T ( % ) SAMPLE NO.04-20-2023 SAMPLE SYMBOLS MO I S T U R E BY:EQUIPMENT ELEV. (MSL.)41' G3112-52-01.GPJ MATERIAL DESCRIPTION LI T H O L O G Y ... STANDARD PENETRATION TEST ... WATER TABLE OR ... SEEPAGE NOTE: PROJECT NO. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. G3112-52-01 TEST NO.:P-1 GEOLOGIC UNIT:Qop EXCAVATION ELEVATION (MSL, FT):41 Reading Time Elapsed (min) Water Weight Consumed (lbs) Water Volume Consumed (in3)Q (in3/min) 1 0.00 0.000 0.00 0.00 2 5.00 1.950 54.00 10.800 3 5.00 2.200 60.92 12.185 4 5.00 1.570 43.48 8.695 5 5.00 1.530 42.37 8.474 6 12.00 3.600 99.69 8.308 7 8.00 2.620 72.55 9.069 8 10.00 3.000 83.08 8.308 9 10.00 3.000 83.08 8.308 FACTOR OF SAFETY: 2.0 BOREHOLE DEPTH (FT): TEST/BOTTOM ELEVATION (MSL, FT): MEASURED HEAD HEIGHT (IN): CALCULATED HEAD HEIGHT (IN): 6.0 6.5 TEST INFORMATION BOREHOLE DIAMETER (IN):8 5.8 35 TEST RESULTS FIELD-SATURATED INFILTRATION RATE (IN/HR): FACTORED INFILTRATION RATE (IN/HR): 0.618 0.309 STEADY FLOW RATE (IN3/MIN):8.308 TEST DATA AARDVARK PERMEAMETER TEST RESULTS 2621 ROOSEVELT STREET PROJECT NO.: G3112-52-01 0.0 5.0 10.0 15.0 0 5 10 15 20 25 30 35 40 45 50 Q (i n 3/m i n ) Time (min) TEST NO.:P-2 GEOLOGIC UNIT:Qop EXCAVATION ELEVATION (MSL, FT):42 Reading Time Elapsed (min) Water Weight Consumed (lbs) Water Volume Consumed (in3)Q (in3/min) 1 0.00 0.000 0.00 0.00 2 11.00 2.150 59.54 5.413 3 9.00 1.600 44.31 4.923 4 10.00 1.230 34.06 3.406 5 10.00 1.230 34.06 3.406 6 10.00 1.240 34.34 3.434 7 10.00 1.230 34.06 3.406 FACTOR OF SAFETY: 2.0 BOREHOLE DEPTH (FT): TEST/BOTTOM ELEVATION (MSL, FT): MEASURED HEAD HEIGHT (IN): CALCULATED HEAD HEIGHT (IN): 5.0 6.5 TEST INFORMATION BOREHOLE DIAMETER (IN):8 5.5 37 TEST RESULTS FIELD-SATURATED INFILTRATION RATE (IN/HR): FACTORED INFILTRATION RATE (IN/HR): 0.287 0.143 STEADY FLOW RATE (IN3/MIN):3.415 TEST DATA AARDVARK PERMEAMETER TEST RESULTS 2621 ROOSEVELT STREET PROJECT NO.: G3112-52-01 0.0 5.0 10.0 15.0 0 5 10 15 20 25 30 35 40 45 50 Q (i n 3/m i n ) Time (min) Appendix D: Geotechnical Engineer Analysis D-1 Jan. 2024 Appendix D Geotechnical Engineer Analysis Analysis of Infiltration Restrictions This section is only applicable if the analysis of infiltration restrictions is performed by a licensed engineer practicing in geotechnical engineering. The SWQMP Preparer and Geotechnical Engineer must work collaboratively to identify any infiltration restrictions identified in Table D.1-1 below. Upon completion of this section, the Geotechnical Engineer must characterize each DMA as Restricted or Unrestricted for infiltration and provide adequate support/discussion in the geotechnical report. A DMA is considered restricted when one or more restrictions exist which cannot be reasonably resolved through site design changes. Table D.1-1: Considerations for Geotechnical Analysis of Infiltration Restrictions Restriction Element Is Element Applicable? (Yes/No) Mandatory Considerations BMP is within 100’ of Contaminated Soils BMP is within 100’ of Industrial Activities Lacking Source Control BMP is within 100’ of Well/Groundwater Basin BMP is within 50’ of Septic Tanks/Leach Fields BMP is within 10’ of Structures/Tanks/Walls BMP is within 10’ of Sewer Utilities BMP is within 10’ of Groundwater Table BMP is within Hydric Soils BMP is within Highly Liquefiable Soils and has Connectivity to Structures BMP is within 1.5 Times the Height of Adjacent Steep Slopes (≥25%) County Staff has Assigned “Restricted” Infiltration Category Optional Considerations BMP is within Predominantly Type D Soil BMP is within 10’ of Property Line BMP is within Fill Depths of ≥5’ (Existing or Proposed) BMP is within 10’ of Underground Utilities BMP is within 250’ of Ephemeral Stream Other (Provide detailed geotechnical support) Result Based on examination of the best available information, I have not identified any restrictions above.  Unrestricted Based on examination of the best available information, I have identified one or more restrictions above.  Restricted Table D.1-1 is divided into Mandatory Considerations and Optional Considerations. Mandatory No No No No No No No No No No N/A No No Yes Yes No Yes, expansive soils X ATTACHMENT 1e Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/11/2023 Page 1 of 4 36 6 9 5 1 0 36 6 9 5 2 0 36 6 9 5 3 0 36 6 9 5 4 0 36 6 9 5 5 0 36 6 9 5 6 0 36 6 9 5 7 0 36 6 9 5 1 0 36 6 9 5 2 0 36 6 9 5 3 0 36 6 9 5 4 0 36 6 9 5 5 0 36 6 9 5 6 0 36 6 9 5 7 0 467190 467200 467210 467220 467230 467240 467250 467260 467270 467280 467290 467190 467200 467210 467220 467230 467240 467250 467260 467270 467280 467290 33° 9' 52'' N 11 7 ° 2 1 ' 7 ' ' W 33° 9' 52'' N 11 7 ° 2 1 ' 2 ' ' W 33° 9' 49'' N 11 7 ° 2 1 ' 7 ' ' W 33° 9' 49'' N 11 7 ° 2 1 ' 2 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 20 40 80 120 Feet 0 5 10 20 30 Meters Map Scale: 1:507 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: San Diego County Area, California Survey Area Data: Version 18, Sep 14, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 14, 2022—Mar 17, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/11/2023 Page 2 of 4 Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI MlC Marina loamy coarse sand, 2 to 9 percent slopes B 0.5 100.0% Totals for Area of Interest 0.5 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/11/2023 Page 3 of 4 Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/11/2023 Page 4 of 4 Category # Description i ii Units 1 Drainage Basin ID or Name DMA-1 unitless 2 85th Percentile 24-hr Storm Depth 0.58 inches 3 Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 16,666 sq-ft 4 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30)sq-ft 5 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10)1,528 sq-ft 6 Natural Type A Soil Not Serving as Dispersion Area (C=0.10)sq-ft 7 Natural Type B Soil Not Serving as Dispersion Area (C=0.14)sq-ft 8 Natural Type C Soil Not Serving as Dispersion Area (C=0.23)sq-ft 9 Natural Type D Soil Not Serving as Dispersion Area (C=0.30)sq-ft 10 Does Tributary Incorporate Dispersion, Tree Wells, and/or Rain Barrels?No yes/no 11 Impervious Surfaces Directed to Dispersion Area per SD-B (Ci=0.90) sq-ft 12 Semi-Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.30)sq-ft 13 Engineered Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.10)sq-ft 14 Natural Type A Soil Serving as Dispersion Area per SD-B (Ci=0.10)sq-ft 15 Natural Type B Soil Serving as Dispersion Area per SD-B (Ci=0.14)sq-ft 16 Natural Type C Soil Serving as Dispersion Area per SD-B (Ci=0.23)sq-ft 17 Natural Type D Soil Serving as Dispersion Area per SD-B (Ci=0.30)sq-ft 18 Number of Tree Wells Proposed per SD-A # 19 Average Mature Tree Canopy Diameter ft 20 Number of Rain Barrels Proposed per SD-E # 21 Average Rain Barrel Size gal 22 Total Tributary Area 18,194 0 sq-ft 23 Initial Runoff Factor for Standard Drainage Areas 0.83 0.00 unitless 24 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 0.00 unitless 25 Initial Weighted Runoff Factor 0.83 0.00 unitless 26 Initial Design Capture Volume 734 0 cubic-feet 27 Total Impervious Area Dispersed to Pervious Surface 0 0 sq-ft 28 Total Pervious Dispersion Area 0 0 sq-ft 29 Ratio of Dispersed Impervious Area to Pervious Dispersion Area n/a n/a ratio 30 Adjustment Factor for Dispersed & Dispersion Areas 1.00 1.00 ratio 31 Runoff Factor After Dispersion Techniques 0.83 n/a unitless 32 Design Capture Volume After Dispersion Techniques 734 0 cubic-feet 33 Total Tree Well Volume Reduction 0 0 cubic-feet 34 Total Rain Barrel Volume Reduction 0 0 cubic-feet 35 Final Adjusted Runoff Factor 0.83 0.00 unitless 36 Final Effective Tributary Area 15,101 0 sq-ft 37 Initial Design Capture Volume Retained by Site Design Elements 0 0 cubic-feet 38 Final Design Capture Volume Tributary to BMP 734 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 Units 1 Drainage Basin ID or Name DMA-1 unitless 2 85th Percentile Rainfall Depth 0.58 inches 3 Predominant NRCS Soil Type Within BMP Location B unitless 4 Is proposed BMP location Restricted or Unrestricted for Infiltration Activities? Restricted unitless 5 Nature of Restriction n/a unitless 6 Do Minimum Retention Requirements Apply to this Project? Yes yes/no 7 Are Habitable Structures Greater than 9 Stories Proposed? No yes/no 8 Has Geotechnical Engineer Performed an Infiltration Analysis? Yes yes/no 9 Design Infiltration Rate Recommended by Geotechnical Engineer 0.226 in/hr 10 Design Infiltration Rate Used To Determine Retention Requirements 0.000 in/hr 11 Percent of Average Annual Runoff that Must be Retained within DMA 4.5% percentage 12 Fraction of DCV Requiring Retention 0.02 ratio 13 Required Retention Volume 15 cubic-feet False False Automated Worksheet B.2: Retention Requirements (V2.0) Advanced Analysis Basic Analysis Result No Warning Messages Category # Description i 1 Drainage Basin ID or Name DMA-1 2 Design Infiltration Rate Recommended 0.000 3 Design Capture Volume Tributary to BMP 734 4 Is BMP Vegetated or Unvegetated? Vegetated 5 Is BMP Impermeably Lined or Unlined? Lined 6 Does BMP Have an Underdrain? Underdrain 7 Does BMP Utilize Standard or Specialized Media? Standard 8 Provided Surface Area 467 9 Provided Surface Ponding Depth 6 10 Provided Soil Media Thickness 24 11 Provided Gravel Thickness (Total Thickness) 12 12 Underdrain Offset 3 13 Diameter of Underdrain or Hydromod Orifice (Select Smallest) 6.00 14 Specialized Soil Media Filtration Rate 15 Specialized Soil Media Pore Space for Retention 16 Specialized Soil Media Pore Space for Biofiltration 17 Specialized Gravel Media Pore Space 18 Volume Infiltrated Over 6 Hour Storm 0 19 Ponding Pore Space Available for Retention 0.00 20 Soil Media Pore Space Available for Retention 0.05 21 Gravel Pore Space Available for Retention (Above Underdrain) 0.00 22 Gravel Pore Space Available for Retention (Below Underdrain) 0.40 23 Effective Retention Depth 2.40 24 Fraction of DCV Retained (Independent of Drawdown Time) 0.13 25 Calculated Retention Storage Drawdown Time 120 26 Efficacy of Retention Processes 0.15 27 Volume Retained by BMP (Considering Drawdown Time) 111 28 Design Capture Volume Remaining for Biofiltration 623 29 Max Hydromod Flow Rate through Underdrain 1.6375 30 Max Soil Filtration Rate Allowed by Underdrain Orifice 151.48 31 Soil Media Filtration Rate per Specifications 5.00 32 Soil Media Filtration Rate to be used for Sizing 5.00 33 Depth Biofiltered Over 6 Hour Storm 30.00 34 Ponding Pore Space Available for Biofiltration 1.00 35 Soil Media Pore Space Available for Biofiltration 0.20 36 Gravel Pore Space Available for Biofiltration (Above Underdrain) 0.40 37 Effective Depth of Biofiltration Storage 14.40 38 Drawdown Time for Surface Ponding 1 39 Drawdown Time for Effective Biofiltration Depth 3 40 Total Depth Biofiltered 44.40 41 Option 1 - Biofilter 1.50 DCV: Target Volume 935 42 Option 1 - Provided Biofiltration Volume 935 43 Option 2 - Store 0.75 DCV: Target Volume 467 44 Option 2 - Provided Storage Volume 467 45 Portion of Biofiltration Performance Standard Satisfied 1.00 46 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements? Yes 47 Overall Portion of Performance Standard Satisfied (BMP Efficacy Factor) 1.00 48 Deficit of Effectively Treated Stormwater 0 Retention Calculations Automated Worksheet B.3: BMP Performance (V2.0) False False BMP Inputs Biofiltration Calculations False False False False Result False False No Warning Messages BF-1 Biofiltration E-108 Sept. 2021 BF-1 Biofiltration Location: 43rd Street and Logan Avenue, San Diego, California Description Biofiltration (Bioretention with underdrain) facilities are vegetated surface water systems that filter water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow to the downstream conveyance system. Bioretention with underdrain facilities are commonly incorporated into the site within parking lot landscaping, along roadsides, and in open spaces. Because these types of facilities have limited or no infiltration, they are typically designed to provide enough hydraulic head to move flows through the underdrain connection to the storm drain system. Treatment is achieved through filtration, sedimentation, sorption, biochemical processes and plant uptake. Typical bioretention with underdrain components include: x Inflow distribution mechanisms (e.g, perimeter flow spreader or filter strips) x Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap) x Shallow surface ponding for captured flows x Side slope and basin bottom vegetation selected based on expected climate and ponding depth x Non-floating mulch layer (Optional) x Media layer (planting mix or engineered media) capable of supporting vegetation growth x Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted native soils or the aggregate storage layer x Aggregate storage layer with underdrain(s) x Impermeable liner or uncompacted native soils at the bottom of the facility x Overflow structure MS4 Permit Category Biofiltration Manual Category Biofiltration Applicable Performance Standard Pollutant Control Flow Control Primary Benefits Treatment Volume Reduction (Incidental) Peak Flow Attenuation (Optional) BF-1 Biofiltration E-109 Sept. 2021 Typical plan and Section view of a Biofiltration BMP MIN. 6” FREEBOARD MAX. 1:1 BF-1 Biofiltration E-110 Sept. 2021 Design Adaptations for Project Goals Biofiltration Treatment BMP for storm water pollutant control. The system is lined or un-lined to provide incidental infiltration, and an underdrain is provided at the bottom to carry away filtered runoff. This configuration is considered to provide biofiltration treatment via flow through the media layer. Storage provided above the underdrain within surface ponding, media, and aggregate storage is considered included in the biofiltration treatment volume. Saturated storage within the aggregate storage layer can be added to this design by raising the underdrain above the bottom of the aggregate storage layer or via an internal weir structure designed to maintain a specific water level elevation. Integrated storm water flow control and pollutant control configuration. The system can be designed to provide flow rate and duration control by primarily providing increased surface ponding and/or having a deeper aggregate storage layer above the underdrain. This will allow for significant detention storage, which can be controlled via inclusion of an outlet structure at the downstream end of the underdrain. Recommended Siting Criteria Siting Criteria Intent/Rationale □ Placement observes geotechnical recommendations regarding potential hazards (e.g., slope stability, landslides, liquefaction zones) and setbacks (e.g., slopes, foundations, utilities). Must not negatively impact existing site geotechnical concerns. □ An impermeable liner or other hydraulic restriction layer is included if site constraints indicate that infiltration or lateral flows should not be allowed. Lining prevents storm water from impacting groundwater and/or sensitive environmental or geotechnical features. Incidental infiltration, when allowable, can aid in pollutant removal and groundwater recharge. □ Contributing tributary area shall be ≤ 5 acres (≤ 1 acre preferred). Bigger BMPs require additional design features for proper performance. Contributing tributary area greater than 5 acres may be allowed at the discretion of the City Engineer if the following conditions are met: 1) incorporate design features (e.g. flow spreaders) to minimizing short circuiting of flows in the BMP and 2) incorporate additional design features requested by the City BF-1 Biofiltration E-111 Sept. 2021 Siting Criteria Intent/Rationale Engineer for proper performance of the regional BMP. □ Finish grade of the facility is ≤ 2%. Flatter surfaces reduce erosion and channelization within the facility. Recommended BMP Component Dimensions BMP Component Dimension Intent/Rationale Freeboard ≥ 6 inches for earth basin ≥ 2 inches for concrete planter/box structure Freeboard provides room for head over overflow structures and minimizes risk of uncontrolled surface discharge. Surface Ponding ≥ 6 and ≤ 12 inches Surface ponding capacity lowers subsurface storage requirements. Deep surface ponding raises safety concerns. Surface ponding depth greater than 12 inches (for additional pollutant control or surface outlet structures or flow-control orifices) may be allowed at the discretion of the City Engineer if the following conditions are met: 1) surface ponding depth drawdown time is less than 24 hours; and 2) safety issues and fencing requirements are considered (typically ponding greater than 18” will require a fence and/or flatter side slopes) and 3) potential for elevated clogging risk is considered. Ponding Area Side Slopes 3H:1V or shallower Gentler side slopes are safer, less prone to erosion, able to establish vegetation more quickly and easier to maintain. Mulch ≥ 3 inches Mulch will suppress weeds and maintain moisture for plant growth. Aging mulch kills pathogens and BF-1 Biofiltration E-112 Sept. 2021 BMP Component Dimension Intent/Rationale weed seeds and allows the beneficial microbes to multiply. Media Layer ≥ 18 inches 1:1 slope maximum for edge condition A deep media layer provides additional filtration and supports plants with deeper roots. Standard specifications shall be followed. For non-standard or proprietary designs, compliance with F.1 ensures that adequate treatment performance will be provided. Underdrain Diameter ≥ 6 inches Smaller diameter underdrains are prone to clogging. Cleanout Diameter ≥ 6 inches Properly spaced cleanouts will facilitate underdrain maintenance. Design Criteria and Considerations Bioretention with underdrain must meet the following design criteria. Deviations from the below criteria may be approved at the discretion of the City Engineer if it is determined to be appropriate: Design Criteria Intent/Rationale Surface Ponding □ Surface ponding is limited to a 24-hour drawdown time. Surface ponding limited to 24 hours for plant health. Surface ponding drawdown time greater than 24-hours but less than 96 hours may be allowed at the discretion of the City Engineer if certified by a landscape architect or agronomist. Vegetation □ Plantings are suitable for the climate and expected ponding depth. A plant list to aid in selection can be found in Appendix E.21. Plants suited to the climate and ponding depth are more likely to survive. □ An irrigation system with a connection to water supply should be provided as needed. Seasonal irrigation might be needed to keep plants healthy. Mulch (Optional) BF-1 Biofiltration E-113 Sept. 2021 Design Criteria Intent/Rationale □ A minimum of 3 inches of well-aged, shredded hardwood mulch that has been stockpiled or stored for at least 12 months is provided. Mulch will suppress weeds and maintain moisture for plant growth. Aging mulch kills pathogens and weed seeds and allows the beneficial microbes to multiply. Media Layer □ Media maintains a minimum filtration rate of 5 in/hr over lifetime of facility. An initial filtration rate of 8 to 12 in/hr is recommended to allow for clogging over time; the initial filtration rate should not exceed 12 inches per hour. A filtration rate of at least 5 inches per hour allows soil to drain between events. The initial rate should be higher than long term target rate to account for clogging over time. However an excessively high initial rate can have a negative impact on treatment performance, therefore an upper limit is needed. □ Media is a minimum 18 inches deep, meeting either of these two media specifications: Section F.3 Bioretention Soil Media (BSM) or specific jurisdictional guidance. Alternatively, for proprietary designs and custom media mixes not meeting the media specifications, the media meets the pollutant treatment performance criteria in Section F.1. A deep media layer provides additional filtration and supports plants with deeper roots. Standard specifications shall be followed. For non-standard or proprietary designs, compliance with F.1 ensures that adequate treatment performance will be provided. □ Media surface area is 3% of contributing area times adjusted runoff factor or greater. Unless demonstrated that the BMP surface area can be smaller than 3%. Greater surface area to tributary area ratios: a) maximizes volume retention as required by the MS4 Permit and b) decrease loading rates per square foot and therefore increase longevity. Adjusted runoff factor is to account for site design BMPs implemented upstream of the BMP (such as rain barrels, impervious area dispersion, etc.). Refer to Appendix B.1 guidance. BF-1 Biofiltration E-114 Sept. 2021 Design Criteria Intent/Rationale □ Where receiving waters are impaired or have a TMDL for nutrients, the system is designed with nutrient sensitive media design (see fact sheet BF-2). Potential for pollutant export is partly a function of media composition; media design must minimize potential for export of nutrients, particularly where receiving waters are impaired for nutrients. Filter Course Layer □ A filter course is used to prevent migration of fines through layers of the facility. Filter fabric is not used. Migration of media can cause clogging of the aggregate storage layer void spaces or subgrade. Filter fabric is more likely to clog. □ Filter course is washed and free of fines. Washing aggregate will help eliminate fines that could clog the facility and impede infiltration. □ Filter course calculations assessing suitability for particle migration prevention have been completed. Gradation relationship between layers can evaluate factors (e.g., bridging, permeability, and uniformity) to determine if particle sizing is appropriate or if an intermediate layer is needed. Aggregate Storage Layer □ Class 2 Permeable per Caltrans specification 68-1.025 is recommended for the storage layer. Washed, open-graded crushed rock may be used, however a 4-6 inch washed pea gravel filter course layer at the top of the crushed rock is required. Washing aggregate will help eliminate fines that could clog the aggregate storage layer void spaces or subgrade. □ The depth of aggregate provided (12-inch typical) and storage layer configuration is adequate for providing conveyance for underdrain flows to the outlet structure. Proper storage layer configuration and underdrain placement will minimize facility drawdown time. Inflow, Underdrain, and Outflow Structures □ Inflow, underdrains and outflow structures are accessible for inspection and maintenance. Maintenance will prevent clogging and ensure proper operation of the flow control structures. □ Inflow velocities are limited to 3 ft/s or less or use energy dissipation methods. (e.g., riprap, level spreader) for concentrated inflows. High inflow velocities can cause erosion, scour and/or channeling. BF-1 Biofiltration E-115 Sept. 2021 Design Criteria Intent/Rationale □ Curb cut inlets are at least 12 inches wide, have a 4-6 inch reveal (drop) and an apron and energy dissipation as needed. Inlets must not restrict flow and apron prevents blockage from vegetation as it grows in. Energy dissipation prevents erosion. □ Underdrain outlet elevation should be a minimum of 3 inches above the bottom elevation of the aggregate storage layer. A minimal separation from subgrade or the liner lessens the risk of fines entering the underdrain and can improve hydraulic performance by allowing perforations to remain unblocked. □ Minimum underdrain diameter is 6 inches. Smaller diameter underdrains are prone to clogging. □ Underdrains are made of slotted, PVC pipe conforming to ASTM D 3034 or equivalent or corrugated, HDPE pipe conforming to AASHTO 252M or equivalent. Slotted underdrains provide greater intake capacity, clog resistant drainage, and reduced entrance velocity into the pipe, thereby reducing the chances of solids migration. □ An underdrain cleanout with a minimum 6- inch diameter and lockable cap is placed every 250 to 300 feet as required based on underdrain length. Properly spaced cleanouts will facilitate underdrain maintenance. □ Overflow is safely conveyed to a downstream storm drain system or discharge point Size overflow structure to pass 100-year peak flow for on-line infiltration basins and water quality peak flow for off-line basins. Planning for overflow lessens the risk of property damage due to flooding. Conceptual Design and Sizing Approach for Storm Water Pollutant Control Only To design bioretention with underdrain for storm water pollutant control only (no flow control required), the following steps should be taken: 1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slopes, and the recommended media surface area tributary ratio. 2. Calculate the DCV per Appendix B based on expected site design runoff for tributary areas. 3. Use the sizing worksheet presented in Appendix B.3 to size biofiltration BMPs. BF-1 Biofiltration E-116 Sept. 2021 Conceptual Design and Sizing Approach when Storm Water Flow Control is Applicable Control of flow rates and/or durations will typically require significant surface ponding and/or aggregate storage volumes, and therefore the following steps should be taken prior to determination of storm water pollutant control design. Pre-development and allowable post-project flow rates and durations should be determined as discussed in Chapter 6 of the manual. 1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slopes, and the recommended media surface area tributary ratio. 2. Iteratively determine the facility footprint area, surface ponding and/or aggregate storage layer depth required to provide detention storage to reduce flow rates and durations to allowable limits. Flow rates and durations can be controlled from detention storage by altering outlet structure orifice size(s) and/or water control levels. Multi-level orifices can be used within an outlet structure to control the full range of flows. 3. If bioretention with underdrain cannot fully provide the flow rate and duration control required by this manual, an upstream or downstream structure with significant storage volume such as an underground vault can be used to provide remaining controls. 4. After bioretention with underdrain has been designed to meet flow control requirements, calculations must be completed to verify if storm water pollutant control requirements to treat the DCV have been met. Maintenance Overview Normal Expected Maintenance. Biofiltration requires routine maintenance to: remove accumulated materials such as sediment, trash or debris; maintain vegetation health; maintain infiltration capacity of the media layer; replenish mulch; and maintain integrity of side slopes, inlets, energy dissipators, and outlets. A summary table of standard inspection and maintenance indicators is provided within this Fact Sheet. Non-Standard Maintenance or BMP Failure. If any of the following scenarios are observed, the BMP is not performing as intended to protect downstream waterways from pollution and/or erosion. Corrective maintenance, increased inspection and maintenance, BMP replacement, or a different BMP type will be required. x The BMP is not drained between storm events. Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging of the media layer, filter course, aggregate storage layer, underdrain, or outlet structure. The specific cause of the drainage issue must be determined and corrected. x Sediment, trash, or debris accumulation greater than 25% of the surface ponding volume within one month. This means the load from the tributary drainage area is too high, reducing BF-1 Biofiltration E-117 Sept. 2021 BMP function or clogging the BMP. This would require pretreatment measures within the tributary area draining to the BMP to intercept the materials. Pretreatment components, especially for sediment, will extend the life of components that are more expensive to replace such as media, filter course, and aggregate layers. x Erosion due to concentrated storm water runoff flow that is not readily corrected by adding erosion control blankets, adding stone at flow entry points, or minor re-grading to restore proper drainage according to the original plan. If the issue is not corrected by restoring the BMP to the original plan and grade, the City Engineer shall be contacted prior to any additional repairs or reconstruction. Other Special Considerations. Biofiltration is a vegetated structural BMP. Vegetated structural BMPs that are constructed in the vicinity of, or connected to, an existing jurisdictional water or wetland could inadvertently result in creation of expanded waters or wetlands. As such, vegetated structural BMPs have the potential to come under the jurisdiction of the United States Army Corps of Engineers, SDRWQCB, California Department of Fish and Wildlife, or the United States Fish and Wildlife Service. This could result in the need for specific resource agency permits and costly mitigation to perform maintenance of the structural BMP. Along with proper placement of a structural BMP, routine maintenance is key to preventing this scenario. BF-1 Biofiltration E-118 Sept. 2021 Summary of Standard Inspection and Maintenance The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to an agency, community facilities district, homeowners association, property owners association, or other special district. Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently. Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior to August 31 and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the minimum inspection and maintenance frequency can be determined based on the results of the first year inspections. Threshold/Indicator Maintenance Action Typical Maintenance Frequency Accumulation of sediment, litter, or debris Remove and properly dispose of accumulated materials, without damage to the vegetation or compaction of the media layer. x Inspect monthly. If the BMP is 25% full* or more in one month, increase inspection frequency to monthly plus after every 0.1- inch or larger storm event. x Remove any accumulated materials found at each inspection. Obstructed inlet or outlet structure Clear blockage. x Inspect monthly and after every 0.5-inch or larger storm event. x Remove any accumulated materials found at each inspection. Damage to structural components such as weirs, inlet or outlet structures Repair or replace as applicable x Inspect annually. x Maintain when needed. Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original plans. x Inspect monthly. x Maintain when needed. BF-1 Biofiltration E-119 Sept. 2021 Threshold/Indicator Maintenance Action Typical Maintenance Frequency Dead or diseased vegetation Remove dead or diseased vegetation, re- seed, re-plant, or re-establish vegetation per original plans. x Inspect monthly. x Maintain when needed. Overgrown vegetation Mow or trim as appropriate. x Inspect monthly. x Maintain when needed. 2/3 of mulch has decomposed, or mulch has been removed Remove decomposed fraction and top off with fresh mulch to a total depth of 3 inches. x Inspect monthly. x Replenish mulch annually, or more frequently when needed based on inspection. Erosion due to concentrated irrigation flow Repair/re-seed/re-plant eroded areas and adjust the irrigation system. x Inspect monthly. x Maintain when needed. Erosion due to concentrated storm water runoff flow Repair/re-seed/re-plant eroded areas, and make appropriate corrective measures such as adding erosion control blankets, adding stone at flow entry points, or minor re- grading to restore proper drainage according to the original plan. If the issue is not corrected by restoring the BMP to the original plan and grade, the City Engineer shall be contacted prior to any additional repairs or reconstruction. x Inspect after every 0.5-inch or larger storm event. If erosion due to storm water flow has been observed, increase inspection frequency to after every 0.1-inch or larger storm event. x Maintain when needed. If the issue is not corrected by restoring the BMP to the original plan and grade, the City Engineer shall be contacted prior to any additional repairs or reconstruction. Standing water in BMP for longer than 24 hours following a storm event Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health Make appropriate corrective measures such as adjusting irrigation system, removing obstructions of debris or invasive vegetation, clearing underdrains, or repairing/replacing clogged or compacted soils. x Inspect monthly and after every 0.5-inch or larger storm event. If standing water is observed, increase inspection frequency to after every 0.1-inch or larger storm event. x Maintain when needed. BF-1 Biofiltration E-120 Sept. 2021 Threshold/Indicator Maintenance Action Typical Maintenance Frequency Presence of mosquitos/larvae For images of egg rafts, larva, pupa, and adult mosquitos, see http://www.mosquito.org/biology If mosquitos/larvae are observed: first, immediately remove any standing water by dispersing to nearby landscaping; second, make corrective measures as applicable to restore BMP drainage to prevent standing water. If mosquitos persist following corrective measures to remove standing water, or if the BMP design does not meet the 96-hour drawdown criteria due to release rates controlled by an orifice installed on the underdrain, the City Engineer shall be contacted to determine a solution. A different BMP type, or a Vector Management Plan prepared with concurrence from the County of San Diego Department of Environmental Health, may be required. x Inspect monthly and after every 0.5-inch or larger storm event. If mosquitos are observed, increase inspection frequency to after every 0.1-inch or larger storm event. x Maintain when needed. Underdrain clogged Clear blockage. x Inspect if standing water is observed for longer than 24-96 hours following a storm event. x Maintain when needed. “25% full” is defined as ¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the bottom elevation, then the materials must be removed when there is 3 inches of accumulation – this should be marked on the outflow structure). Trash Capture Calculations for Q draining into Biofiltration Basin (DMA-1) Q = C x I x 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 in inches per hour. (typical i=0.471 in/hr) A = Tributary area (acres) which includes the total area draining to the trash capture BMP, including any offsite or onsite areas that comingle with project runoff and drain to the trash capture BMP. Rainfall intensity of 0.471 in/hr for one-year, one-hour storm event which is based on the precipitation frequency data station at Oceanside Pumping Plant (Latitude: 33.1330°, Longitude: -117.3259°) IMP-1 (Biofiltration): C = ((0.9 x 16,666) + (0.14 x 1,528)) / (18,194) = 0.84 A = 0.42 ac Q = 0.84 x 0.471 x 0.42 = 0.166 cfs Insertion of Bio Clean Catch Basin Inlet Filer (BIO-GRATE-FULL- 12-12-12) to filter the runoff draining into catch basin located in the biofiltration basin. ENGINEERED SOLUTIONS Full Trash Capture Full Capture Sizing Full Capture Removes 100% of Trash ... The Full Trash Capture line of inlet filters are listed as Certified Trash Full Capture Systems by the California State Water Resources Control Board in both grate inlet and curb inlet configurations. The filters allow for higher flow rates and cleaning is easy and efficient, making them a great choice for demanding applications. MODEL #TREATMENT FLOW RATE (CFS) BYPASS FLOW RATE (CFS) STORAGE CAPACITY (CU FT) BIO-CURB-FULL-12 2.85 UNLIMITED 0.70 BIO-CURB-FULL-24 2.85 UNLIMITED 1.40 BIO-GRATE-FULL-12-12-12 1.04 1.24 0.15 BIO-GRATE-FULL-18-18-12 1.78 2.79 0.33 BIO-GRATE-FULL-24-24-12 2.70 4.96 0.59 BIO-GRATE-FULL-24-40-12 3.70 6.35 0.88 BIO-GRATE-FULL-24-24-24 7.31 4.96 1.22 BIO-GRATE-FULL-24-40-24 9.53 6.35 1.82 BIO-GRATE-FULL-36-36-24 11.93 7.74 2.73 Note: Flow rate includes safety factor of two for screen capacity. Storage capacity based on filter basket at 50% full. Bypass Flow Path Treatment Flow Path Mounting Flange High Flow Bypass Non-Clogging Screens Bottom Screen Built to last longer than other trash capture filters TREE-WELL Category # Description ii Units 1 Drainage Basin ID or Name DMA 4&5 unitless 2 85th Percentile 24-hr Storm Depth 0.58 inches 3 Is Hydromodification Control Applicable? No yes/no 4 Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 2,282 sq-ft 5 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30) sq-ft 6 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10) 133 sq-ft 7 Natural Type A Soil Not Serving as Dispersion Area (C=0.10) sq-ft 8 Natural Type B Soil Not Serving as Dispersion Area (C=0.14) sq-ft 9 Natural Type C Soil Not Serving as Dispersion Area (C=0.23) sq-ft 10 Natural Type D Soil Not Serving as Dispersion Area (C=0.30) sq-ft 11 Does Tributary Incorporate Dispersion and/or Rain Barrels? yes/no 12 Does Tributary Incorporate Tree Wells? Yes yes/no 13 Impervious Surfaces Directed to Dispersion Area per SD-B (Ci=0.90) sq-ft 14 Semi-Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.30) sq-ft 15 Engineered Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.10) sq-ft 16 Natural Type A Soil Serving as Dispersion Area per SD-B (Ci=0.10) sq-ft 17 Natural Type B Soil Serving as Dispersion Area per SD-B (Ci=0.14) sq-ft 18 Natural Type C Soil Serving as Dispersion Area per SD-B (Ci=0.23) sq-ft 19 Natural Type D Soil Serving as Dispersion Area per SD-B (Ci=0.30) sq-ft 20 Number of Rain Barrels Proposed per SD-E # 21 Average Rain Barrel Size gal 22 Total Tributary Area 2,415 sq-ft 23 Initial Runoff Factor for Standard Drainage Areas 0.86 unitless 24 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 unitless 25 Initial Weighted Runoff Factor 0.86 unitless 26 Initial Design Capture Volume 100 cubic-feet 27 Total Impervious Area Dispersed to Pervious Surface 0 sq-ft 28 Total Pervious Dispersion Area 0 sq-ft 29 Ratio of Dispersed Impervious Area to Pervious Dispersion Area for DCV Reduction n/a ratio 30 Adjustment Factor for Dispersed & Dispersion Areas 1.00 ratio 31 Runoff Factor After Dispersion Techniques 0.86 unitless 32 Design Capture Volume After Dispersion Techniques 100 cubic-feet 33 Total Rain Barrel Volume Reduction 0 cubic-feet 34 Final Adjusted Runoff Factor 0.86 unitless 35 Final Effective Tributary Area 2,077 sq-ft 36 Initial Design Capture Volume Retained by Dispersion Area and Rain Barrel(s) 0 cubic-feet 37 Remaining Design Capture Volume Tributary to Tree Well(s) 100 cubic-feet SSD-BMP Automated Worksheet I-1: Step 1. Calculation of Design Capture Volume (V1.0) Standard Drainage Basin Inputs Results Dispersion Area Adjustment & Rain Barrel Adjustment SSD-BMPs Proposed Dispersion Area & Rain Barrel Inputs (Optional) Initial Runoff Factor Calculation Category # Description ii Units 1 Drainage Basin ID or Name DMA 4&5 unitless 2 Design Capture Volume Tributary to BMP 100 cubic-feet 3 Is Hydromodification Control Applicable? No yes/no 4 Predominant NRCS Soil Type Within Tree Well(s) Location B unitless 5 Select a Tree Species for the Tree Well(s) Consistent with SD-A Tree Palette Table Note: Numbers shown in list are Tree Species Mature Canopy Diameters 15' - Other unitless 6 Tree Well(s) Soil Depth (Installation Depth) Must be 30, 36, 42, or 48 Inches; Select from Standard Depths**48 inches 7 Number of Identical* Tree Wells Proposed for this DMA 1 trees 8 Proposed Width of Tree Well(s) Soil Installation for One (1) Tree 9.0 feet 9 Proposed Length of Tree Well(s) Soil Installation for One (1) Tree 10.0 feet 10 Botanical Name of Tree Species Provide in PDP SWQMP unitless 11 Tree Species Mature Height per SD-A Provide in PDP SWQMP feet 12 Tree Species Mature Canopy Diameter per SD-A 15 feet 13 Minimum Soil Volume Required In Tree Well (2 Cubic Feet Per Square Foot of Mature Tree Canopy Projection Area)353 cubic-feet 14 Credit Volume Per Tree 100 cubic-feet 15 DCV Multiplier To Meet Flow Control Requirements n/a unitless 16 Required Retention Volume (RRV) To Meet Flow Control Requirements n/a cubic-feet 17 Number of Trees Required 1 trees 18 Total Area of Tree Well Soil Required for Each Tree 88 sq-ft 19 Approximate Required Width of Tree Well Soil Area for Each Tree 10 feet 20 Approximate Required Length of Tree Well Soil Area for Each Tree 10 feet 21 Number of Trees Proposed for this DMA 1 trees 22 Total Area of Tree Well Soil Proposed for Each Tree 90 sq-ft 23 Minimum Spacing Between Multiple Trees To Meet Soil Area Requirements (when applicable)***n/a feet 24 Are Tree Well Soil Installation Requirements Met? Yes yes/no 25 Is Remaining DCV Requirement Fully Satisfied by Tree Well(s)? Yes yes/no 26 Is Hydromodification Control Requirement Satisfied by Tree Well(s)? n/a yes/no SSD-BMP Automated Worksheet I-3: Step 3. Tree Well Sizing (V1.0) Standard Tree Well Inputs Tree Data Tree Well Sizing Calculations Results SD-A Tree Well E-3 Jan. 2024 SD-A Tree Well (Source: County of San Diego LID Manual – EOA, Inc.) Description Trees planted to intercept rainfall and runoff as described in this fact sheet may be used as storm water management measures to provide runoff reduction of the DCV per Appendix B.1.4. Additional benefits associated with tree wells, include energy conservation, air quality improvement, and aesthetic enhancement. Tree wells located in the City’s Right-of-Way are subject to the discretion of City Engineer and Parks and Recreation Director. Typical storm water management benefits associated with trees include: • Treatment of storm water – Storm water from impervious area should be directed to the tree wells. Trees provide treatment through uptake of nutrients and other storm water pollutants (phytoremediation) and support of other biological processes that break down pollutants • Interception of rainfall – tree surfaces (roots, foliage, bark, and branches) intercept, evaporate, store, or convey precipitation to the soil before it reaches surrounding impervious surfaces • Reduced erosion – trees protect denuded area by intercepting or reducing the velocity of rain drops as they fall through the tree canopy • Increased infiltration – soil conditions created by roots and fallen leaves promote infiltration MS4 Permit Category Site Design Retention Manual Category Site Design Infiltration Applicable Performance Standard Site Design Pollutant Control Flow Control Primary Benefits Volume Reduction SD-A Tree Well E-4 Jan. 2024 Typical tree well system components include: • Directing runoff from impervious areas through a drainage opening into a tree well planting area. • Trees of the appropriate species for site conditions and constraints. Refer to the Plant List fact sheet (Appendix E.21). • Available soil media reservoir volume based on mature tree size, soil type, water availability, surrounding land uses, and project goals • Optional suspended pavement design to provide structural support for adjacent pavement without requiring compaction of underlying layers • Optional root barrier devices as needed; a root barrier is a device installed in the ground, between a tree and the sidewalk or other structures, intended to guide roots down and away from the sidewalk or structures in order to prevent damage from tree roots. • Optional tree grates; to be considered to maximize available space for pedestrian circulation and to protect tree roots from compaction related to pedestrian circulation; tree grates are typically made up of porous material that will allow the runoff to soak through. • Optional shallow surface depression for ponding of excess runoff • Optional planter box underdrain Design Adaptations for Project Goals Site design BMP to provide incidental treatment. Tree wells primarily functions as site design BMPs for incidental treatment. Storm water pollutant control BMP to provide treatment. Project proponents are allowed to design tree wells to reduce the volume of stormwater runoff that requires treatment, (the Design Capture Volume [DCV]), or completely fulfill the pollutant control BMP requirements by retaining the entire DCV. Benefits from tree wells are accounted for by using the volume reduction values in Table B.1-3 presented in Appendix B. This credit can apply to other trees that are used for landscaping purposes that meet the same criteria. Project proponents are required to provide calculations supporting the amount of credit claimed from implementing trees within the project footprint. Tree wells designed to completely fulfill the pollutant control BMP requirements by retaining the entire Schematic of Tree Well SD-A Tree Well E-5 Jan. 2024 DCV are designated as SSD-BMPs and located in Appendix I. Flow Control BMP to meet hydromodification requirements. Project proponents are also allowed to design tree wells as a flow control BMP. Benefits from tree wells are accounted for by using the DCV multipliers listed in Appendix I. Project proponents are required to provide calculations showing that the entire DCV including the DCV multiplier is retained. Design Criteria and Considerations Tree Wells, whether designed as Site Design BMPs, as Stormwater Pollutant Control BMP, or as a Flow Control BMP must meet the following design criteria and considerations, and if placed in the right-of-way must be consistent with the County of San Diego Green Streets Standard Drawings. Deviations from the below criteria may be approved at the discretion of the City Engineer if it is determined to be appropriate: Siting and Design Intent/Rationale □ Tree species is appropriately chosen for the development (private or public). For public rights-of-ways, city planning guidelines and zoning provisions for the permissible species and placement of trees are consulted. A list of trees appropriate for site design are provided in Appendix E.21 Proper tree placement and species selection minimizes problems such as pavement damage by surface roots and poor growth. □ Tree well placement: ensure area is graded; and the well is located so that full amount of DCV reduction drains to well. Minimizes short-circuiting of run off and assures DCV reductions are retained onsite. □ Location of trees planted along public streets follows city requirements and guidelines. Vehicle and pedestrian line of sight are considered in tree selection and placement. Location of trees planted within private development follows city landscape guidelines. Building setbacks, utility alignments, vehicle and pedestrian line of sight are considered in tree selection and placement. Unless otherwise approved by the City Engineer the following minimum tree separation distance is followed Roadway safety for both vehicular and pedestrian traffic is a key consideration for placement along public streets. SD-A Tree Well E-6 Jan. 2024 Siting and Design Intent/Rationale Improvement Minimum distance to Tree Well Traffic Signal, Stop sign 20 feet Underground Utility lines (except sewer) 5 feet Sewer Lines 10 feet Above ground utility structures (Transformers, Hydrants, Utility poles, etc.) 10 feet Driveways 10 feet Intersections (intersecting curb lines of two streets) 25 feet □ Underground utilities and overhead wires are considered in the design and avoided or circumvented. Underground utilities are routed around or through the planter in suspended pavement applications. All underground utilities are protected from water and root penetration. Tree growth can damage utilities and overhead wires resulting in service interruptions. Protecting utilities routed through the planter prevents damage and service interruptions. □ Suspended pavement is used for confined Tree Well soil volume. Suspended pavement design was developed where appropriate to minimize soil compaction and improve infiltration and filtration capabilities. Suspended pavement was constructed with an approved structural cell. Suspended pavement designs provide structural support without compaction of the underlying layers, thereby promoting tree growth. Recommended structural cells include poured in place concrete columns, Silva Cells manufactured by Deeproot Green Infrastructures and Stratacell and Stratavault systems manufactured by Citygreen Systems or approved equal. Suspended pavement shall not be used within the city’s right-of-way and easements. □ A minimum soil volume of 2 cubic feet per square foot of canopy projection volume is provided for each tree. Canopy projection area The minimum soil volume ensures that there is adequate storage volume to allow for unrestricted evapotranspiration and infiltration. SD-A Tree Well E-7 Jan. 2024 Siting and Design Intent/Rationale is the ground area beneath the tree, measured at the drip line. Soil volume must be within 1.5 times the mature tree canopy radius. Soil depth shall be a minimum of 30 inches deep, preferably 36 inches deep. When placing tree well next to curbs or other structures use Structural Soil as outlined in the section below titled “Confined Tree Well Soil Volume”. Use Amended Soil per Fact Sheet SD-F in all other cases. □ DCV from the tributary area draining to the tree is equal to or greater than the tree credit volume The minimum tributary area ensures that the tree receives enough runoff to fully utilize the infiltration and evapotranspiration potential provided. In cases where the minimum tributary area is not provided, the tree credit volume must be reduced proportionately to the actual tributary area. □ Inlet opening to the tree that is at least 18 inches wide. A minimum 2 inch drop in grade from the inlet to the finish grade of the tree. Grated inlets are allowed for pedestrian circulation. Grates need to be ADA compliant and have sufficient slip resistance. Design requirement to ensure that the runoff from the tributary area is not bypassed. Different inlet openings and drops in grade may be allowed at the discretion of the City Engineer if calculations are shown that the diversion flow rate (Appendix B.4.4) from the tributary area can be conveyed to the tree. In cases where the inlet capacity is limiting the amount of runoff draining to the tree, the tree credit volume must be reduced proportionately. Conceptual Design and Sizing Approach for Site Design Determine the areas where tree wells can be used in the site design to achieve incidental treatment. Tree wells reduce runoff volumes from the site. Refer to Appendix B.1. Document the proposed tree locations in the SWQMP. For conceptual design and sizing approach for pollutant control and flow control, refer to Appendix I. SD-A Tree Well E-8 Jan. 2024 Tree Planting Design in New or Reconstructed Streetscapes 1. Maximized open soil area for tree planting is the most cost effective method of achieving the required soil volume. 2. Tree wells within sidewalks shall have a minimum open area of four feet wide by six feet long. Larger areas may be required to accommodate large root balls. 3. Tree well soil characteristics shall meet the requirements of SD-F Amended Soil. Structural Requirements for Confined Tree Well Soil Volume In order to provide adequate soil volume for tree wells, soils may be placed confined beneath adjacent paved surfaces. Acceptable soil systems capable of carrying D-50 loading include structural soils, structural slabs, and structural cells: 1. Structural soil systems include CU-StructuralSoilTM, Stalite Structural Soil, or equivalent. 2. Suspended pavements that allow uncompacted growing soil beneath the sidewalk include; structural slabs that span between structural supports, structural cells, and other commercially available structural systems. Manufacturer details and certification must be provided for commercial systems. Structural calculations and details must be provided for structural slab installations. Structural cells are commercially-available structural systems placed subsurface that support the sidewalk and are filled with amended soil (SD-F). Manufacturer details and certification must be provided for commercial systems. Suspended pavement shall not be used within the city’s right-of-way and easements. Stormwater Retention and Treatment Volume Tree wells with expanded soil volume will serve as a method of capturing and retaining the required volume of stormwater in accordance with City requirements in Appendix B of this manual. These facilities can be designed to meet the City requirements when surface ponding volume is provided, whether designed as an enclosed plant bed with covered soil volume, or a continuous open area (either mulched or with turf) with soil volume under the adjacent sidewalk. Maintenance Overview Normal Expected Maintenance. Tree health shall be maintained as part of normal landscape maintenance. Additionally, ensure that storm water runoff can be conveyed into the tree well as designed. That is, the opening that allows storm water runoff to flow into the tree well (e.g., a curb opening, tree grate, or surface depression) shall not be blocked, filled, re-graded, or otherwise changed in a manner that prevents storm water from draining into the tree well. A summary table of standard inspection and maintenance indicators is provided within this Fact Sheet. Non-Standard Maintenance or BMP Failure. Trees wells are site design BMPs that normally do not require maintenance actions beyond routine landscape maintenance. The normal expected SD-A Tree Well E-9 Jan. 2024 maintenance described above ensures the BMP functionality. If changes have been made to the tree well entrance / opening such that runoff is prevented from draining into the tree well (e.g., a curb inlet opening is blocked by debris or a grate is clogged causing runoff to flow around instead of into the tree well, or a surface depression has been filled so runoff flows away from the tree well), the BMP is not performing as intended to protect downstream waterways from pollution and/or erosion. Corrective maintenance will be required to restore drainage into the tree well as designed. Surface ponding of runoff directed into tree wells is expected to infiltrate/evapotranspire within 24- 96 hours following a storm event. Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging or compaction of the soils surrounding the tree. Loosen or replace the soils to restore drainage. Other Special Considerations. Site design BMPs, such as tree wells, installed within a new development or redevelopment project are components of an overall storm water management strategy for the project. The presence of site design BMPs within a project is usually a factor in the determination of the amount of runoff to be managed with structural BMPs (i.e., the amount of runoff expected to reach downstream retention or biofiltration basins that process storm water runoff from the project as a whole). When site design BMPs are not maintained or are removed, this can lead to clogging or failure of downstream structural BMPs due to greater delivery of runoff and pollutants than intended for the structural BMP. Therefore, the City Engineer may require confirmation of maintenance of site design BMPs as part of their structural BMP maintenance documentation requirements. Site design BMPs that have been installed as part of the project should not be removed, nor should they be bypassed by re-routing roof drains or re-grading surfaces within the project. If changes are necessary, consult the City Engineer to determine requirements. SD-A Tree Well E-10 Jan. 2024 Summary of Standard Inspection and Maintenance The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to an agency, community facilities district, homeowners association, property owners association, or other special district. Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently. Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior to August 31 and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the minimum inspection and maintenance frequency can be determined based on the results of the first year inspections. Threshold/Indicator Maintenance Action Typical Maintenance Frequency Tree health Routine actions as necessary to maintain tree health. • Inspect monthly. • Maintain when needed. Dead or diseased tree Remove dead or diseased tree. Replace per original plans. • Inspect monthly. • Maintain when needed. Standing water in tree well for longer than 24 hours following a storm event Surface ponding longer than approximately 24 hours following a storm event may be detrimental to tree health Loosen or replace soils surrounding the tree to restore drainage. • Inspect monthly and after every 0.5-inch or larger storm event. If standing water is observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintain when needed. Presence of mosquitos/larvae For images of egg rafts, larva, pupa, and adult mosquitos, see http://www.mosquito.org/biology Disperse any standing water from the tree well to nearby landscaping. Loosen or replace soils surrounding the tree to restore drainage (and prevent standing water). • Inspect monthly and after every 0.5-inch or larger storm event. If mosquitos are observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintain when needed SD-A Tree Well E-11 Jan. 2024 Threshold/Indicator Maintenance Action Typical Maintenance Frequency Entrance / opening to the tree well is blocked such that storm water will not drain into the tree well (e.g., a curb inlet opening is blocked by debris or a grate is clogged causing runoff to flow around instead of into the tree well; or a surface depression is filled such that runoff drains away from the tree well) Make repairs as appropriate to restore drainage into the tree well. • Inspect monthly. • Maintain when needed. ATTACHMENT 2 BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES [This is the cover sheet for Attachment 2.] N/A (HMP Exempt) ATTACHMENT 3 Structural BMP Maintenance Information Use this checklist to ensure the required information has been included in the Structural BMP Maintenance Information Attachment: Preliminary Design/Planning/CEQA level submittal: Attachment 3 must identify: Typical maintenance indicators and actions for proposed structural BMP(s) based on Section 7.7 of the BMP Design Manual Final Design level submittal: Attachment 3 must identify: 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 . 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 PREVENTATIVE MAINTENANCE AND ROUTINE INSPECTION LANDSCAPING & IRRIGATION PROPER IRRIGATION & FERTILIZER. LESS THAN 80% COVERAGE 30 DAYS PRIOR TO OCTOBER 1ST EACH YEAR AND MONTHLY RE-SEED OR RE- PLANT. REPAIR IRRIGATION SYSTEM WITH-IN 5-DAYS. ALL SLOPES AND LANDSCAPED AREAS ARE TO HAVE A MINIMUM COVERAGE OF 80% TRASH STORAGE AREAS TRASH FREE AND REMOVAL OF SILT VISUAL INSPECTION DAILY INSPECTION REMOVE TRASH AND SILT DAILY. ALL TRASH STORAGE AREAS TO BE FREE FROM TRASH AND SILT AT ALL TIMES BIOFILTRATION TRASH FREE AND REMOVAL OF SILT. CLEAR CLOGGED OUTLETS AND STANDING WATER. SILT BUILD UP OF MORE THAN 2” NO TRASH, EXPOSED SOILS, DEAD VEGETATION, PONDED WATER, AND EXCESSIVE VEGETATION (SEE TC-32) 30 DAYS PRIOR TO OCTOBER 1ST EACH YEAR, MONTHLY DURING RAINY SEASON, AND AFTER STORM EVENT REMOVE TRASH AND SILT – REPAIR AND RESEED EXPOSED AREAS, MAINTAIN GRASS HEIGHT SO AS NOT BE SHORTER THAN 2” OR HIGHER THAN 5” REMOVE ALL PONDED WATER WEEKLY INSPECTIONS, (SEE TC- 32) ALL BIO-FILTERS TO BE FREE FROM TRASH AND SILT AT ALL TIMES, GRASS AREA TO BE FREE FROM EXPOSED SOIL AND MAINTAINED TO PROPER HEIGHT, PONDING OF WATER FOR MORE THAN 72 HOURS MAINTENANCE WILL BE REQUIRED STORMWATER CONVEYANE SYSTEM STENCILING & SIGNING MUST BE LEGIBLE AT ALL TIMES AND HAVE A CLEAR VIEW. FADING OF PAINT OR ILLEGIBLE LETTERS OR SEMI- ANNUALLY, 30 DAYS PRIOR TO OCTOBER 1ST EACH YEAR & MONTHLY DURING RAINY SEASON REPAINT STENCILING AND/OR REPLACE SIGNS 30 DAYS PRIOR TO OCTOBER 1ST. APPLICABLE TO ALL STENCILING AND SIGNS OUTLET STRUCTURS MUST BE KEPT FUNCTIONAL AT ALL TIMES. CLEAR CLOGGED OUTLETS AND STANDING WATER. SILT, DEBRIS, TRASH ACCUMULATION, PONDING WATER 30 DAYS PRIOR TO OCTOBER 1ST EACH YEAR AND WEEKLY DURING RAINY SEASON OR WITHIN 24 HOURS PRIOR TO RAIN FORECASTS. SILT, DEBRIS, TRASH ACCUMULATION AND REPAIR ANY STRUCTURAL DAMAGE TO THE OUTLET STRUCTURES. ALL OUTLET STRUCTURES SHALL BE KEPT FUNCTIONAL AT ALL TIMES. ROUTINE ACTION MAINTENANCE INDICATOR FIELD MEASUREMENT MEASUREMENT FREQUENCY MAINTENANCE ACTIVITY FREQUENCY (# OF TIMES PER YEAR) VEGETATION MANAGEMENT FOR AESTHETICS (OPTIONAL) AVERAGE VEGETATION HEIGHT GREATER THAN 12-INCHES, EMERGENCE OF TREES OR WOODY VEGETATION, VISUAL OBSERVATION AND RANDOM MEASUREMENT S THROUGH OUT THE SIDE SLOPE AREA ANNUALLY, PRIOR TO START OF WET SEASON CUT VEGETATION TO AN AVERAGE HEIGHT OF 6- INCHES AND REMOVE TRIMMINGS. REMOVE ANY TREES, OR WOODY VEGETATION. 1.0 SOIL REPAIR EVIDENCE OF EROSION VISUAL OBSERVATION ANNUALLY, PRIOR TO START OF WET SEASON RESEED/REVEGETATE BARREN SPOTS PRIOR TO WET SEASON. 1.0 STANDING WATER STANDING WATER FOR MORE THAN 96 HRS VISUAL OBSERVATION ANNUALLY, 96 HOURS AFTER A TARGET STORM (0.60 IN) EVENT DRAIN FACILITY. CORRECTIVE ACTION PRIOR TO WET SEASON. CONSULT ENGINEERS IF IMMEDIATE SOLUTION IS NOT EVIDENT. 1.0 TRASH AND DEBRIS TRASH AND DEBRIS PRESENT VISUAL OBSERVATION ANNUALLY, PRIOR TO START OF WET SEASON REMOVE AND DISPOSE OF TRASH AND DEBRIS 1.0 SEDIMENT MANAGEMENT SEDIMENT DEPTH EXCEEDS 10% OF THE FACILITY DESIGN MEASURE DEPTH AT APPARENT MAXIMUM AND MINIMUM ACCUMULATION OF SEDIMENT. CALCULATE AVERAGE DEPTH ANNUALLY, PRIOR TO START OF WET SEASON REMOVE AND PROPERLY DISPOSE OF SEDIMENT. REGRADE IF NECESSARY. (EXPECTED EVERY 2 YEARS) 1.0 UNDERDRAINS EVIDENCE OF CLOGGING VISUAL OBSERVATION ANNUALLY, PRIOR TO START CORRECTIVE ACTION PRIOR TO WET SEASON. 1.0 OF WET SEASON CONSULT ENGINEERS IF IMMEDIATE SOLUTION IS NOT EVIDENT. GENERAL MAINTENANCE INSPECTION INLET STRUCTURES, OUTLET STRUCTURES, SIDE SLOPES OR OTHER FEATURES DAMAGED, SIGNIFICANT EROSION, BURROWS, EMERGENCE OF TREES OR WOODY VEGETATION, GRAFFITI OR VANDALISM, FENCE DAMAGE, ETC. VISUAL OBSERVATION ANNUALLY, PRIOR TO START OF WET SEASON CORRECTIVE ACTION PRIOR TO WET SEASON. CONSULT ENGINEERS IF IMMEDIATE SOLUTION IS NOT EVIDENT. 1.0 TRASH AND DEBRIS FROM WIER TRASH AND DEBRIS PRESENT VISUAL OBSERVATION MONTHLY DURING WET SEASON REMOVE AND DISPOSE OF TRASH AND DEBRIS 6.0 WATER SEAL ON WIER WATER SEEPAGE THROUGH SIDE OF WIER PLATE VISUAL OBSERVATION MONTHLY DURING WET SEASON REMOVE CAULKING AROUND WIER PLATE, RECAULK, REPLACE WIER PLATE IF NECESSARY 6.0 SEDIMENT MANAGEMENT AROUND ORIFICE OF WIER PLATE ANY AND ALL SEDIMENT AROUND WIER PLATE VISUAL OBSERVATION MONTHLY DURING WET SEASON REMOVE AND PROPERLY DISPOSE OF SEDIMENT. 6.0 BF-1 Biofiltration BMP MAINTENANCE FACT SHEET FOR STRUCTURAL BMP BF-1 BIOFILTRATION Biofiltration facilities are vegetated surface water systems that filter water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow to the downstream conveyance system. Biofiltration facilities have limited or no infiltration. They are typically designed to provide enough hydraulic head to move flows through the underdrain connection to the storm drain system. Typical biofiltration components include: • Inflow distribution mechanisms (e.g., perimeter flow spreader or filter strips) • Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap) • Shallow surface ponding for captured flows • Side slope and basin bottom vegetation selected based on climate and ponding depth • Non-floating mulch layer • Media layer (planting mix or engineered media) capable of supporting vegetation growth • Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted native soils or the aggregate storage layer • Aggregate storage layer with underdrain(s) • Impermeable liner or uncompacted native soils at the bottom of the facility • Overflow structure Normal Expected Maintenance Biofiltration requires routine maintenance to: remove accumulated materials such as sediment, trash or debris; maintain vegetation health; maintain infiltration capacity of the media layer; replenish mulch; and maintain integrity of side slopes, inlets, energy dissipators, and outlets. A summary table of standard inspection and maintenance indicators is provided within this Fact Sheet. Non-Standard Maintenance or BMP Failure If any of the following scenarios are observed, the BMP is not performing as intended to protect downstream waterways from pollution and/or erosion. Corrective maintenance, increased inspection and maintenance, BMP replacement, or a different BMP type will be required. • The BMP is not drained between storm events. Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging of the media layer, filter course, aggregate storage layer, underdrain, or outlet structure. The specific cause of the drainage issue must be determined and corrected. • Sediment, trash, or debris accumulation greater than 25% of the surface ponding volume within one month. This means the load from the tributary drainage area is too high, reducing BMP function or clogging the BMP. This would require pretreatment measures within the tributary area draining to the BMP to intercept the materials. Pretreatment components, especially for sediment, will extend the life of components that are more expensive to replace such as media, filter course, and aggregate layers. • Erosion due to concentrated storm water runoff flow that is not readily corrected by adding erosion control blankets, adding stone at flow entry points, or minor re-grading to restore proper drainage according to the original plan. If the issue is not corrected by restoring the BMP to the original plan and grade, the [City Engineer] shall be contacted prior to any additional repairs or reconstruction. BF-1 Page 1 of 11 January 12, 2017 BF-1 Biofiltration Other Special Considerations Biofiltration is a vegetated structural BMP. Vegetated structural BMPs that are constructed in the vicinity of, or connected to, an existing jurisdictional water or wetland could inadvertently result in creation of expanded waters or wetlands. As such, vegetated structural BMPs have the potential to come under the jurisdiction of the United States Army Corps of Engineers, SDRWQCB, California Department of Fish and Wildlife, or the United States Fish and Wildlife Service. This could result in the need for specific resource agency permits and costly mitigation to perform maintenance of the structural BMP. Along with proper placement of a structural BMP, routine maintenance is key to preventing this scenario. BF-1 Page 2 of 11 January 12, 2017 BF-1 Biofiltration SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR BF-1 BIOFILTRATION The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to an agency, community facilities district, homeowners association, property owners association, or other special district. Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently. Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior to August 31 and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the minimum inspection and maintenance frequency can be determined based on the results of the first year inspections. Threshold/Indicator Maintenance Action Typical Maintenance Frequency Accumulation of sediment, litter, or debris Remove and properly dispose of accumulated materials, without damage to the vegetation or compaction of the media layer. • Inspect monthly. If the BMP is 25% full* or more in one month, increase inspection frequency to monthly plus after every 0.1-inch or larger storm event. • Remove any accumulated materials found at each inspection. Obstructed inlet or outlet structure Clear blockage. • Inspect monthly and after every 0.5-inch or larger storm event. • Remove any accumulated materials found at each inspection. Damage to structural components such as weirs, inlet or outlet structures Repair or replace as applicable • Inspect annually. • Maintenance when needed. Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original plans. • Inspect monthly. • Maintenance when needed. Dead or diseased vegetation Remove dead or diseased vegetation, re-seed, re-plant, or re-establish vegetation per original plans. • Inspect monthly. • Maintenance when needed. Overgrown vegetation Mow or trim as appropriate. • Inspect monthly. • Maintenance when needed. 2/3 of mulch has decomposed, or mulch has been removed Remove decomposed fraction and top off with fresh mulch to a total depth of 3 inches. • Inspect monthly. • Replenish mulch annually, or more frequently when needed based on inspection. *“25% full” is defined as ¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the bottom elevation, then the materials must be removed when there is 3 inches of accumulation – this should be marked on the outflow structure). BF-1 Page 3 of 11 January 12, 2017 BF-1 Biofiltration SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR BF-1 BIOFILTRATION (Continued from previous page) Threshold/Indicator Maintenance Action Typical Maintenance Frequency Erosion due to concentrated irrigation flow Repair/re-seed/re-plant eroded areas and adjust the irrigation system. • Inspect monthly. • Maintenance when needed. Erosion due to concentrated storm water runoff flow Repair/re-seed/re-plant eroded areas, and make appropriate corrective measures such as adding erosion control blankets, adding stone at flow entry points, or minor re-grading to restore proper drainage according to the original plan. If the issue is not corrected by restoring the BMP to the original plan and grade, the [City Engineer] shall be contacted prior to any additional repairs or reconstruction. • Inspect after every 0.5-inch or larger storm event. If erosion due to storm water flow has been observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintenance when needed. If the issue is not corrected by restoring the BMP to the original plan and grade, the [City Engineer] shall be contacted prior to any additional repairs or reconstruction. Standing water in BMP for longer than 24 hours following a storm event Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health Make appropriate corrective measures such as adjusting irrigation system, removing obstructions of debris or invasive vegetation, clearing underdrains, or repairing/replacing clogged or compacted soils. • Inspect monthly and after every 0.5-inch or larger storm event. If standing water is observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintenance when needed. Presence of mosquitos/larvae For images of egg rafts, larva, pupa, and adult mosquitos, see http://www.mosquito.org/biology If mosquitos/larvae are observed: first, immediately remove any standing water by dispersing to nearby landscaping; second, make corrective measures as applicable to restore BMP drainage to prevent standing water. If mosquitos persist following corrective measures to remove standing water, or if the BMP design does not meet the 96-hour drawdown criteria due to release rates controlled by an orifice installed on the underdrain, the [City Engineer] shall be contacted to determine a solution. A different BMP type, or a Vector Management Plan prepared with concurrence from the County of San Diego Department of Environmental Health, may be required. • Inspect monthly and after every 0.5-inch or larger storm event. If mosquitos are observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintenance when needed. Underdrain clogged Clear blockage. • Inspect if standing water is observed for longer than 24-96 hours following a storm event. • Maintenance when needed. BF-1 Page 4 of 11 January 12, 2017 BF-1 Biofiltration References American Mosquito Control Association. http://www.mosquito.org/ California Storm Water Quality Association (CASQA). 2003. Municipal BMP Handbook. https://www.casqa.org/resources/bmp-handbooks/municipal-bmp-handbook County of San Diego. 2014. Low Impact Development Handbook. http://www.sandiegocounty.gov/content/sdc/dpw/watersheds/susmp/lid.html San Diego County Copermittees. 2016. Model BMP Design Manual, Appendix E, Fact Sheet BF-1. http://www.projectcleanwater.org/index.php?option=com_content&view=article&id=250&Itemid=220 BF-1 Page 5 of 11 January 12, 2017 BF-1 Biofiltration Page Intentionally Blank for Double-Sided Printing BF-1 Page 6 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): Property / Development Name: Responsible Party Name and Phone Number: Property Address of BMP: Responsible Party Address: INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 1 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Accumulation of sediment, litter, or debris Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Remove and properly dispose of accumulated materials, without damage to the vegetation ☐ If sediment, litter, or debris accumulation exceeds 25% of the surface ponding volume within one month (25% full*), add a forebay or other pre-treatment measures within the tributary area draining to the BMP to intercept the materials. ☐ Other / Comments: Poor vegetation establishment Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Re-seed, re-plant, or re-establish vegetation per original plans ☐ Other / Comments: *“25% full” is defined as ¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the bottom elevation, then the materials must be removed when there is 3 inches of accumulation – this should be marked on the outflow structure). BF-1 Page 7 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 2 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Dead or diseased vegetation Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Remove dead or diseased vegetation, re- seed, re-plant, or re-establish vegetation per original plans ☐ Other / Comments: Overgrown vegetation Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Mow or trim as appropriate ☐ Other / Comments: 2/3 of mulch has decomposed, or mulch has been removed Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Remove decomposed fraction and top off with fresh mulch to a total depth of 3 inches ☐ Other / Comments: BF-1 Page 8 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 3 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Erosion due to concentrated irrigation flow Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Repair/re-seed/re-plant eroded areas and adjust the irrigation system ☐ Other / Comments: Erosion due to concentrated storm water runoff flow Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Repair/re-seed/re-plant eroded areas, and make appropriate corrective measures such as adding erosion control blankets, adding stone at flow entry points, or minor re-grading to restore proper drainage according to the original plan ☐ If the issue is not corrected by restoring the BMP to the original plan and grade, the [City Engineer] shall be contacted prior to any additional repairs or reconstruction ☐ Other / Comments: BF-1 Page 9 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 4 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Obstructed inlet or outlet structure Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Clear blockage ☐ Other / Comments: Underdrain clogged (inspect underdrain if standing water is observed for longer than 24-96 hours following a storm event) Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Clear blockage ☐ Other / Comments: Damage to structural components such as weirs, inlet or outlet structures Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Repair or replace as applicable ☐ Other / Comments: BF-1 Page 10 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 5 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Standing water in BMP for longer than 24-96 hours following a storm event* Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Make appropriate corrective measures such as adjusting irrigation system, removing obstructions of debris or invasive vegetation, clearing underdrains, or repairing/replacing clogged or compacted soils ☐ Other / Comments: Presence of mosquitos/larvae For images of egg rafts, larva, pupa, and adult mosquitos, see http://www.mosquito.org/biology Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Apply corrective measures to remove standing water in BMP when standing water occurs for longer than 24-96 hours following a storm event.** ☐ Other / Comments: *Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging of the media layer, filter course, aggregate storage layer, underdrain, or outlet structure. The specific cause of the drainage issue must be determined and corrected. **If mosquitos persist following corrective measures to remove standing water, or if the BMP design does not meet the 96-hour drawdown criteria due to release rates controlled by an orifice installed on the underdrain, the [City Engineer] shall be contacted to determine a solution. A different BMP type, or a Vector Management Plan prepared with concurrence from the County of San Diego Department of Environmental Health, may be required. BF-1 Page 11 of 11 January 12, 2017 © 2024 Contech Engineered Solutions LLC, a QUIKRETE Company All Rights Reserved. Printed in the USA. 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 Bio Clean® Catch Basin Inlet Filter Maintenance Filters can be easily accessed from the surface without entering the catch basin and can be maintained by a vac truck or by hand. ENGINEERED SOLUTIONS Bio Clean® Grate Inlet Filter Full Capture Type Operation & Maintenance Manual 2 Operation & Maintenance Contech’s Bio Clean® Grate Inlet Filter is a stormwater catch basin filter designed to remove trash, debris, sediments, particulates, and hydrocarbons (with hydrocarbon boom add-on). Constructed of 100% stainless steel, the filters are available at various sizes and depths, allowing them to fit in any grated catch basin inlet. The heavy duty construction allows for cleaning with any vacuum truck. The filter can also easily be cleaned by hand. As with all stormwater BMPs, inspection and maintenance on the Grate Inlet Filter is necessary. 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 site-specific loading conditions. This is recommended because pollutant loading can vary greatly from site to site. Variables such as nearby soil erosion or construction sites, winter sanding of roads, amount of daily traffic, and land use can increase pollutant loading on the system. The first year of inspections can be used to set inspection and maintenance intervals for subsequent years. Without appropriate maintenance, a BMP can exceed its storage capacity which can negatively affect its continued performance in removing and retaining captured pollutants. Filter Diagram Grate Mounting Flange Outlet Pipe Filter Basket High Flow Bypass 3 Inspection Equipment Following is a list of equipment to allow for simple and effective inspection of the Grate Inlet Filter: •Contech Inspection Form (page 7 of this O&M Manual). •Manhole hook or appropriate tools to remove access hatches and covers. •Appropriate traffic control signage and procedures. •Protective clothing and eye protection. •Note: entering a confined space requires appropriate safety procedures, PPE, and certification. It is generally not required for routine inspections or maintenance of the system. Inspection Steps The core to any successful stormwater BMP maintenance program is routine inspections. The inspection steps required on the Grate Inlet Filter are quick and easy. As mentioned above the first year should be seen as the maintenance interval establishment phase. During the first year more frequent inspections should occur in order to gather loading data and maintenance requirements for that specific site. This information can be used to establish a base for long-term inspection and maintenance interval requirements. The Grate Inlet Filter can be inspected though visual observation without entry into the catch basin. All necessary pre- inspection steps must be carried out before inspection occurs, such as safety measures to protect the inspector and nearby pedestrians from any dangers associated with an open access hatch or manhole. Once the manhole has been safely opened the inspection process can proceed, as follows: •Prepare the inspection form by writing in the necessary information including project name, location, date & time, unit number and other details as noted (page 7 of this O&M Manual). •Observe the inside of the catch basin through the manhole. If minimal light is available and vision into the unit is impaired utilize a flashlight to see inside the catch basin. •Look for any out of the ordinary obstructions in the catch basin, trough, weir, filter basket, basin floor our outlet pipe. Write down any observations on the inspection form. •Through observation and/or digital photographs estimate the amount of trash, foliage and sediment accumulated inside the filter basket. Record this information on the inspection form. •Observe the condition and color of the hydrocarbon boom. Record this information on the inspection form. •Finalize inspection report for analysis by the maintenance manager to determine if maintenance is required. 4 Maintenance Indicators Based upon observations made during inspection, maintenance of the system may be required based on the following indicators: •Missing or damaged internal components. •Obstructions in the filter basket and/or its bypass. •Excessive accumulation of trash, foliage and sediment in the filter basket. Maintenance is required when the basket is greater than half-full. •The following chart shows the 50% and 100% storage capacity of each filter height: Maintenance Equipment Following is a list of equipment to allow for simple and effective maintenance of the Grate Inlet Filter. It is recommended that a vacuum truck be utilized to minimize the time required to maintain the Grate Inlet Filter, though it can easily be cleaned by hand. •Contech Maintenance Form (page 7 of this O&M Manual). •Manhole hook or appropriate tools to access hatches and covers. •Appropriate safety signage and procedures. •Protective clothing and eye protection. •Small or large vacuum truck (with pressure washer attachment preferred). •Note: entering a confined space requires appropriate safety procedures, PPE, and certification. It is generally not required for routine maintenance of the system. Basket Model Height1 (inches) Top Width (inches) Top Length (inches) Bottom Width (inches) Bottom Length (inches) 50% Storage Capacity (CF) 100% Storage Capacity (CF) BC-GRATE-FULL-12-12-12 6.00 10.00 10.00 8.31 8.31 0.15 0.30 BC-GRATE-FULL-18-18-12 6.00 15.00 15.00 12.50 12.50 0.33 0.66 BC-GRATE-FULL-24-24-12 6.00 20.00 20.00 16.69 16.69 0.59 1.18 BC-GRATE-FULL-24-24-24 18.00 20.00 20.00 10.00 10.00 1.22 2.44 BC-GRATE-FULL-24-40-12 6.00 20.00 30.00 16.69 25.00 0.88 1.76 BC-GRATE-FULL-24-40-24 18.00 20.00 30.00 10.00 15.00 1.82 3.64 BC-GRATE-FULL-36-36-24 18.00 30.00 30.00 15.00 15.00 2.73 5.46 1 Refers to basket height. Total system height is equal to basket height plus 6 inches for bypass. 5 Maintenance Procedures It is recommended that maintenance occurs at least two days after the most recent rain event to allow debris and sediments to dry out. Maintaining the system while flows are still entering it will increase the time and complexity required for maintenance. Cleaning of the Grate Inlet Filter can be performed from finish surface without entry into catch basin utilizing a vacuum truck. Some unique and custom configurations may create conditions which would require entry for some or all of the maintenance procedures. All necessary pre-maintenance steps must be carried out before maintenance begins, such as safety measures to protect the maintainer and nearby pedestrians from any dangers associated with an open access hatch or manhole. Once the manhole has been safely removed, the maintenance process can proceed: •Inspect the Grate Inlet Filter as detailed under Inspection Steps above (page 3 of this O&M Manual). •Using an extension on a vacuum truck, position the hose over the opened catch basin. Insert the vacuum hose down into the filter basket and suck out trash, foliage, and sediment. Pressure wash the sides and bottom of the filter basket to remove any stuck debris. •Remove the optional hydrocarbon boom that is attached to the inside of the filter basket (if present). The hydrocarbon boom is fastened to vertical rails on two opposite sides of the basket. Assess the color and condition of the boom using the diagram below. If replacement is required, install and fasten on a new hydrocarbon boom. Booms can be ordered directly from the manufacturer. •Below is a replacement indication color chart for the hydrocarbon booms. •When maintenance is complete, replace the grate and remove all traffic control. •All removed debris and pollutants shall be disposed of following local and state requirements. •Disposal requirements for recovered pollutants may vary depending on local guidelines. In most areas the sediment, once dewatered, can be disposed of in a sanitary landfill. It is not anticipated that the sediment would be classified as hazardous waste. •In the case of damaged components, replacement parts can be ordered from the manufacturer. Hydrocarbon booms can also be ordered directly from the manufacturer as previously noted. EXCELLENT CONDITION GOOD CONDITION MINIMAL CAPACITY REPLACEMENT REQUIRED 6 Maintenance Sequence 1. Remove grate and set up vacuum truck to clean the filter basket. 3. Replace the grate and remove all traffic control. All removed debris and pollutants shall be disposed of following local and state requirements. 2. Insert the vacuum hose down into the filter basket and suck out debris. Pressure wash the sides and bottom of the filter basket to remove any stuck debris. 7 For Office Use Only (city)(Zip Code)(Reviewed By) Owner / Management Company (Date) Contact Phone ( )_ MP / MAemiT// etaD emaN rotcepsnI Weather Condition itiddA onal Notes Site Map # Long: Storm Event in Last 72-hours? No Yes GPS Coordinates of Insert Catch Basin Size Evidence of Illicit Discharge? Trash Accumulation Type of Inspection Routine Follow Up Complaint Storm Lat: Long: Lat: Long: Sediment Accumulation Office personnel to complete section to the left. Functioning Properly or Maintenance Needed? Comments: Foliage Accumulation Long: Lat: Long: Lat: 3 Lat: 2 1 Long: Inspection and Maintenance Report Catch Basin Only Signs of Structural Damage? 5 4 6 Lat: Lat: Lat: Long: 7 Lat: Long: 10 8 Long: Project Name Project Address 12 Lat: 11 Lat: Long: Long: ENGINEERED 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. GIF Full Capture Operation & Maintenance Manual 06/23 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 SD-1 Tree Wells BMP MAINTENANCE FACT SHEET FOR SITE DESIGN BMP SD-1 TREE WELLS Tree wells as site design BMPs are trees planted in configurations that allow storm water runoff to be directed into the soil immediately surrounding the tree. The tree may be contained within a planter box or structural cells. The surrounding area will be graded to direct runoff to the tree well. There may be features such as tree grates, suspended pavement design, or shallow surface depressions designed to allow runoff into the tree well. Typical tree well components include: • Trees of the appropriate species for site conditions and constraints • Available growing space based on tree species, soil type, water availability, surrounding land uses, and project goals • Entrance/opening that allows storm water runoff to flow into the tree well (e.g., a curb opening, tree grate, or surface depression) • Optional suspended pavement design to provide structural support for adjacent pavement without requiring compaction of underlying layers • Optional root barrier devices as needed; a root barrier is a device installed in the ground, between a tree and the sidewalk, intended to guide roots down and away from the sidewalk in order to prevent sidewalk lifting from tree roots • Optional tree grates; to be considered to maximize available space for pedestrian circulation and to protect tree roots from compaction related to pedestrian circulation; tree grates are typically made up of porous material that will allow the runoff to soak through • Optional shallow surface depression for ponding of excess runoff • Optional planter box drain Normal Expected Maintenance Tree health shall be maintained as part of normal landscape maintenance. Additionally, ensure that storm water runoff can be conveyed into the tree well as designed. That is, the opening that allows storm water runoff to flow into the tree well (e.g., a curb opening, tree grate, or surface depression) shall not be blocked, filled, re-graded, or otherwise changed in a manner that prevents storm water from draining into the tree well. A summary table of standard inspection and maintenance indicators is provided within this Fact Sheet. Non-Standard Maintenance or BMP Failure Tree wells are site design BMPs that normally do not require maintenance actions beyond routine landscape maintenance. The normal expected maintenance described above ensures the BMP functionality. If changes have been made to the tree well entrance / opening such that runoff is prevented from draining into the tree well (e.g., a curb inlet opening is blocked by debris or a grate is clogged causing runoff to flow around instead of into the tree well, or a surface depression has been filled so runoff flows away from the tree well), the BMP is not performing as intended to protect downstream waterways from pollution and/or erosion. Corrective maintenance will be required to restore drainage into the tree well as designed. Surface ponding of runoff directed into tree wells is expected to infiltrate/evapotranspirate within 24-96 hours following a storm event. Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging or compaction of the soils surrounding the tree. Loosen or replace the soils to restore drainage. SD-1 Page 1 of 6 January 12, 2017 SD-1 Tree Wells Other Special Considerations Site design BMPs, such as tree wells, installed within a new development or redevelopment project are components of an overall storm water management strategy for the project. The presence of site design BMPs within a project is usually a factor in the determination of the amount of runoff to be managed with structural BMPs (i.e., the amount of runoff expected to reach downstream retention or biofiltration basins that process storm water runoff from the project as a whole). When site design BMPs are not maintained or are removed, this can lead to clogging or failure of downstream structural BMPs due to greater delivery of runoff and pollutants than intended for the structural BMP. Therefore, the [City Engineer] may require confirmation of maintenance of site design BMPs as part of their structural BMP maintenance documentation requirements. Site design BMPs that have been installed as part of the project should not be removed, nor should they be bypassed by re-routing roof drains or re-grading surfaces within the project. If changes are necessary, consult the [City Engineer] to determine requirements. SD-1 Page 2 of 6 January 12, 2017 SD-1 Tree Wells SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR SD-1 TREE WELLS The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to an agency, community facilities district, homeowners association, property owners association, or other special district. Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently. Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior to August 31 and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the minimum inspection and maintenance frequency can be determined based on the results of the first year inspections. Threshold/Indicator Maintenance Action Typical Maintenance Frequency Tree health Routine actions as necessary to maintain tree health. • Inspect monthly. • Maintenance when needed. Dead or diseased tree Remove dead or diseased tree. Replace per original plans. • Inspect monthly. • Maintenance when needed. Standing water in tree well for longer than 24 hours following a storm event Surface ponding longer than approximately 24 hours following a storm event may be detrimental to tree health Loosen or replace soils surrounding the tree to restore drainage. • Inspect monthly and after every 0.5-inch or larger storm event. If standing water is observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintenance when needed. Presence of mosquitos/larvae For images of egg rafts, larva, pupa, and adult mosquitos, see http://www.mosquito.org/biology Disperse any standing water from the tree well to nearby landscaping. Loosen or replace soils surrounding the tree to restore drainage (and prevent standing water). • Inspect monthly and after every 0.5-inch or larger storm event. If mosquitos are observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintenance when needed Entrance / opening to the tree well is blocked such that storm water will not drain into the tree well (e.g., a curb inlet opening is blocked by debris or a grate is clogged causing runoff to flow around instead of into the tree well; or a surface depression is filled such that runoff drains away from the tree well) Make repairs as appropriate to restore drainage into the tree well. • Inspect monthly. • Maintenance when needed. SD-1 Page 3 of 6 January 12, 2017 SD-1 Tree Wells References American Mosquito Control Association. http://www.mosquito.org/ County of San Diego. 2014. Low Impact Development Handbook. http://www.sandiegocounty.gov/content/sdc/dpw/watersheds/susmp/lid.html San Diego County Copermittees. 2016. Model BMP Design Manual, Appendix E, Fact Sheet SD-1. http://www.projectcleanwater.org/index.php?option=com_content&view=article&id=250&Itemid=220 SD-1 Page 4 of 6 January 12, 2017 SD-1 Tree Wells Date: Inspector: BMP ID No.: Permit No.: APN(s): Property / Development Name: Responsible Party Name and Phone Number: Property Address of BMP: Responsible Party Address: INSPECTION AND MAINTENANCE CHECKLIST FOR SD-1 TREE WELLS PAGE 1 of 2 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Dead or diseased tree Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Remove dead or diseased tree ☐ Replace per original plans ☐ Other / Comments: Standing water in tree well for longer than 24 hours following a storm event Surface ponding longer than approximately 24 hours following a storm event may be detrimental to tree health Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Loosen or replace soils surrounding the tree to restore drainage ☐ Other / Comments: SD-1 Page 5 of 6 January 12, 2017 SD-1 Tree Wells Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR SD-1 TREE WELLS PAGE 2 of 2 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Presence of mosquitos/larvae For images of egg rafts, larva, pupa, and adult mosquitos, see http://www.mosquito.org/biology Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Disperse any standing water from the tree well to nearby landscaping ☐ Loosen or replace soils surrounding the tree to restore drainage (and prevent standing water) ☐ Other / Comments: Entrance / opening to the tree well is blocked such that storm water will not drain into the tree well (e.g., a curb inlet opening is blocked by debris or a grate is clogged causing runoff to flow around instead of into the tree well; or a surface depression is filled such that runoff drains away from the tree well) Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Make repairs as appropriate to restore drainage into the tree well ☐ Other / Comments: SD-1 Page 6 of 6 January 12, 2017 ATTACHMENT 4 City standard Single Sheet BMP (SSBMP) Exhibit [Use the City’s standard Single Sheet BMP Plan.] D DD S W DR I V E W A Y E N T R A N C E PARKING LOT DRIVEWAY EXISTING 1 STORY BUILDING RF=52.93 XXX X X X X X X X X XPARKING LOT SHED 6' H I G H C H A I N L I N K F E N C E BLOCK WALL IM P - 2 ( T R E E - W E L L ) 9' x 1 0 ' w / 1 5 ' C A N O P Y PROPOSED SD LUG SD EX. CURB INLET EX. CURB INLET SD SD SD SD SD SD SD 551 - 7A BMP NOTES: PARTY RESPONSIBLE FOR MAINTENANCE: NAME ADDRESS PHONE NO. CONTACT PLAN PREPARED BY: NAME ADDRESS PHONE NO. CERTIFICATION COMPANY SIGNATURE BMP CONSTRUCTION AND INSPECTION NOTES: THE 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. 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. 5.REFER TO MAINTENANCE AGREEMENT DOCUMENT. 6.SEE PROJECT SWMP FOR ADDITIONAL INFORMATION. MICHAEL D. SCHWEITZER 1635 LAKE SAN MARCOS DR. (760)744-0011 SWS ENGINEERING, INC. SUITE 200 SAN MARCOS, CA 92078 PERMANENT WATER QUALITY TREATMENT FACILITY KEEPING OUR WATERWAYS CLEAN MAINTAIN WITH CARE - NO MODIFICATIONS WITHOUT AGENCY APPROVAL 2621 ROOSEVELT STREET ST.#8 (619) - 678 - 1074 CARLSBAD, CA 92008 2621 ROOSEVELT STREET ST.#8 WATER QUALITY SIGN - TYPICAL DETAIL NTS DIAL TOLL FREE 1 - 800 - 422 - 4133 AT LEAST TWO DAYS BEFORE YOU DIG T.M. UNDERGROUND SERVICE ALERT OF SOUTHERN CALIFORNIA BMP TYPEBMP ID #SYMBOL CASQA NO.DRAWING NO.SHEET NO.(S)MAINTENANCE FREQUENCY BMP TABLE INSPECTION FREQUENCYQUANTITY TREATMENT CONTROL LOW IMPACT DESIGN (L.I.D.) SOURCE CONTROL TRASH ENCLOSURE SD-32 BF-1 MONTHLY- STENCILS SD-13DRAINS TO OCEANNO DUMPING ** MONTHLY & IMP (1) 876 SF 1 AFTER STORM MONTHLY MONTHLY & AFTER STORM- 1 12 MONTHLY AS NEEDED AS NEEDED SEMI ANNUALLY SIGNAGE TREATMENT FACILITYPERMANENT WATER QUALITY 1 AS NEEDED AS NEEDED TREE WELL IMP (2) - PRETREATMENT DEVICE BIOFILTRATION (BF-1) BIO-GRATE-FULL-12-12-12 (INDOOR) PLANTER 234 SFDECOMPOSED 640 SF MONTHLY MONTHLY & AFTER STORM ROOF DRAIN TO LANDSCAPING SD MONTHLY MONTHLY MONTHLY & AFTER STORM MONTHLY & AFTER STORM SD-A TC-32 SD-11 - - 1 8 - - - - - - - TRASH CAPTURE TC-50 TC-32 EC-16 9'X10' W/15' CANOPY 551-7 SHT 3 RCE 59658 BRENDAN FOOTE