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Home My WebLink AboutPA2023-0053_20230623_WQMP dated 06-15-23Plan Check PC2023-____ Preliminary Water Quality Management Plan (pWQMP) PLACENTIA APARTMENTS Portion of Lots 715 & 716 First Addition to Newport Mesa Tract APN: 4224-161-08 1526 Placentia, Newport Beach, California Prepared for: MR. JEFF CEFALIA 1224 W. Oceanfront Newport Beach, CA 92661 Contact: Jeff Cefalia (949) 933-7986 Prepared by: TOAL ENGINEERING, INC. 139 Avenida Navarro, San Clemente, CA 92672 www.toalengineering.com Contact: CALEB RIOS, R.C.E. 57587 (949) 492-8586 crios@toalengineering.com Prepared on: 06/15/23 Template Prepared: December 20, 2013 Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Owner’s Certification Project Owner’s Certification Permit/Application No. (TBD) Grading Permit No. (TBD) Tract/Parcel Map No. Por. Lots 715/716, 1st. Add. Newport Mesa Tract Building Permit No. (TBD) CUP, SUP, and/or APN (Specify Lot Numbers if Portions of Tract) 424-161-08 This Water Quality Management Plan (WQMP) has been prepared for Jeff Cefalia by Toal Engineering, Inc. The WQMP is intended to comply with the requirements of the local NPDES Stormwater Program requiring the preparation of the plan. The undersigned, while it owns the subject property, is responsible for the implementation of the provisions of this plan and will ensure that this plan is amended as appropriate to reflect up-to-date conditions on the site consistent with the current Orange County Drainage Area Management Plan (DAMP) and the intent of the non-point source NPDES Permit for Waste Discharge Requirements for the County of Orange, Orange County Flood Control District and the incorporated Cities of Orange County within the San Diego Region (South Orange County).. Once the undersigned transfers its interest in the property, its successors-in-interest shall bear the aforementioned responsibility to implement and amend the WQMP. An appropriate number of approved and signed copies of this document shall be available on the subject site in perpetuity. Owner: Title Jeff Cefalia Company n/a Address 1027 W. Bay Avenue, Newport Beach, CA 92663 Email jeff@cefaliadevelopment.com Telephone # (949) 933-7986 Signature Date Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Table of Contents Contents Page No. Section I Discretionary Permit(s) and Water Quality Conditions ..................................... 3 Section II Project Description .......................................................................................... 4 Section III Site Description ............................................................................................. 8 Section IV Best Management Practices (BMPs) ............................................................. 11 Section V Inspection/Maintenance Responsibility for BMPs .......................................... 27 Section VI Site Plan and Drainage Plan ......................................................................... 28 Section VII Educational Materials .................................................................................. 29 Attachments Attachment A . .........................................................................................BMP Fact Sheets Attachment B………………………………………………………………….. Educational Materials Attachment C……………………………………………………………………………... Location Map Attachment D……………………………………………………..Operation and Maintenance Plan Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section I Page 3 Section I Discretionary Permit(s) and Water Quality Conditions Project Infomation Permit/Application No. (TBD) Tract/Parcel Map No. Por. Lots 715/716, 1st. Add. Newport Mesa Tract Additional Information/ Comments: Project Address: 1526 Placentia, Newport Beach, California APN: 424-161-08 Water Quality Conditions Water Quality Conditions (list verbatim) 1. All significant redevelopment projects consisting of addition or replacement of 5,000 or more square feet of impervious surface on an already developed site. Watershed-Based Plan Conditions Provide applicable conditions from watershed - based plans including TMDLS. TMDLs for Lower Newport Bay: Nutrients (1998) Toxics (2002) Fecal Coliform (1999) Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section II Page 4 Section II Project Description II.1 Project Description Description of Proposed Project Development Category (Verbatim from WQMP): 1. All significant redevelopment projects, where significant redevelopment is defined as the addition or replacement of 5,000 or more square feet of impervious surface on an already developed site. Redevelopment does not include routine maintenance activities that are conducted to maintain original line and grade, hydraulic capacity, original purpose of the facility, or emergency redevelopment activity required to protect public health and safety If the redevelopment results in the addition or replacement of less than 50 percent of the impervious area on-site and the existing development was not subject to WQMP requirement, the numeric sizing criteria discussed in Section 7.II-2.0 only applies to the addition or replacement area. If the addition or replacement accounts for 50 percent or more of the impervious area, the Project WQMP requirements apply to the entire development Project Area (ft2): 15,054 Lot size: (ft2): 16,275 Number of Dwelling Units: 1 SIC Code: n/a Narrative Project Description: The project consists of the following: (1) demolition of the existing residence and associated hardscape (2) construction of a new custom multi-family residence and appurtenant hardscape, landscape, and drainage improvements. Project Area Pervious Impervious Area (sf) Percentage Area (sf) Percentage Pre-Project Conditions 710 4 14,344 95 Post-Project Conditions 1310 8 13,744 91 Drainage Patterns/Connections See Section III.2. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section II Page 5 II.2 Potential Stormwater Pollutants The following table lists the expected stormwater pollutants based on land uses and site activities per Table 2.1 of the Technical Guidance Document for the Preparation of Project Water Quality Management Plans (TGD). Pollutants of Concern Pollutant Circle One: E=Expected to be of concern N=Not Expected to be of concern Additional Information and Comments Suspended-Solid / Sediment ◇E N Nutrients ◇E N Heavy Metals E ◇N Pathogens (Bacteria/Virus) ◇E N Pesticides ◇E N Oil and Grease ◇E N Toxic Organic Compounds E ◇N Trash and Debris ◇E N Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section II Page 6 II.3 Hydrologic Conditions of Concern Determine if streams located downstream from the project area are determined to be potentially susceptible to hydromodification impacts. Refer to Appendix C of the Model WQMP for reference to applicable technical guidance for determining if downstream channels are susceptible to HCOCs. No – Show map and/or describe and reference supporting documentation in the space below. Yes – Describe applicable hydrologic conditions of concern in the space below. (source: http://landrecords.ocpublicworks.com/ocsl/) Hydrologic Conditions of Concern (HCOCs) do not exist for this project since site runoff is conveyed in a storm drain system and discharged directly into Newport Bay. As shown above per the North County Hydromodification and Susceptibility Map for Newport Bay (Figure XVI-3d in the TGD) the project does not lie within any susceptible area. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section II Page 7 II.4 Post Development Drainage Characteristics Post-construction surface drainage will be directed to the same ultimate discharge points as prior to construction. Runoff will be collected in an area drain system and into treatment/retention areas before being discharged to Placentia Avenue. The drainage system is shown on the Grading and Drainage Plan for the project. II.5 Property Ownership/Management This property is privately owned by: Mr. Jeff Cefalia 1526 Placentia Newport Beach, CA 92663 Tel: (949) 933-7986 Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section III Page 8 Section III Site Description III.1 Physical Setting Planning Area/ Community Name N/A Location/Address 1526 Placentia, Newport Beach, California Project Area Description The subject property lies northwesterly of lower Newport Bay. The surrounding area is developed with similar multi-family residential units and some commercial development. Land Use Multi-Unit Residential Zoning RM-H (3100/2420) Acreage Property Lot size: 16,275 s.f. (0.374 acres) Project: 15,054 s.f. (0.346 acres) Predominant Soil Type Soils are classified as Hydrologic Soil Group D by the Orange County Soil Survey. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section III Page 9 III.2 Site Characteristics Precipitation Zone 0.70-in (TGD Fig XVI-1) Topography Elevations on the developed portion of the site range from a maximum of about 102-feet at the northerly end to a minimum of about 99-feet at the Southerly end. Drainage Patterns/Connections Under existing conditions, the runoff from the site flows along the Curb and Gutter at Placentia and enters the city catch basin to the south of the project, at the Northeast corner of Placentia Avenue and 15th Street Soil Type, Geology, and Infiltration Properties Per EGA Geotechnical Soils Report No JC389-1: “A percolation study is beyond our scope of work. However, based on the silt/clayey, cohesive soil matrix encountered in the upper 10 feet, we assume the infiltration rate is less than 0.30 inches/hour. The soils are considered hydrologic Group “C” soils which requires BMPs implemented by the project civil engineer” Hydrogeologic (Groundwater) Conditions Per EGA Geotechnical Soils Report No JC389-1, boring tests did not encounter any groundwater to a total depth of 10.5 feet. Geotechnical Conditions (relevant to infiltration) See above. Off-Site Drainage The project site does not receive run-on from adjacent properties. Utility and Infrastructure Information Public and private utilities are already in place for this property. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section III Page 10 III.3 Watershed Description Receiving Waters Lower Newport Bay 303(d) Listed Impairments Chlordane, Copper, DDT, Indicator Bacteria, Nutrients, PCBs, Pesticides, Sediment Toxicity Applicable TMDLs Sediment, Nutrients, Toxics, Fecal Coliform Pollutants of Concern for the Project Primary Pollutants of Concern: Chlordane, Copper, DDT, Indicator Bacteria, Nutrients, PCBs, Pesticides, Sediment Toxicity. Other Pollutants of Concern: None. Environmentally Sensitive and Special Biological Significant Areas Lower Newport Bay. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 11 Section IV Best Management Practices (BMPs) IV. 1 Project Performance Criteria Project Performance Criteria If HCOC exists, list applicable hydromodification control performance criteria (MWQMP Appendix C) Per Section II.3 of this report, HCOCs do not exist for the proposed project. List applicable LID performance criteria (Section 7.II-2.4.3 from MWQMP) • Priority Projects must infiltrate, harvest and use, evapotranspire, or biotreat/biofilter, the 85th percentile, 24-hour storm event (Design Capture Volume). • A properly designed biotreatment system may only be considered if infiltration, harvest and use, and evapotranspiration (ET) cannot be feasibly implemented for the full design capture volume. In this case, infiltration, harvest and use, and ET practices must be implemented to the greatest extent feasible and biotreatment may be provided for the remaining design capture volume. Calculate LID DCV for Project. Simple Method per TGD III.1.1. 𝐷𝐷𝐷𝐷𝐷𝐷=𝐷𝐷 × 𝑑𝑑 × 𝐴𝐴 𝐷𝐷= (0.75 × 𝑖𝑖𝑖𝑖𝑖𝑖+ 0.15)= 0.75 × 0.91 + 0.15 = 0.83 𝑑𝑑= 0.70 𝑖𝑖𝑖𝑖. 𝐴𝐴= 15,054 𝑠𝑠𝑠𝑠.𝑓𝑓𝑓𝑓. 𝐷𝐷𝐷𝐷𝐷𝐷= 0.83 x 0.70 𝑖𝑖𝑖𝑖.x 15,054 𝑠𝑠.𝑓𝑓.x �1 𝑓𝑓𝑓𝑓.12 𝑖𝑖𝑖𝑖.�=729 𝑐𝑐𝑓𝑓 Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 12 IV.2. SITE DESIGN AND DRAINAGE PLAN Overview The ultimate plan of development for the proposed project is shown on the WQMP Site Plan in Section VI of this report. The project Grading Plan shows the proposed grading and site improvements necessary for construction of the proposed residential building. Site Design Practices The project incorporates Site Design practices as follows: • Preserve Existing Drainage Patterns and Time of Concentration – The ultimate points of discharge are the same for the pre- and post-project conditions. Time of concentration will be similar, since pre-and post-project flow path lengths will be similar. Drainage Management Areas (DMAs) The site has five Drainage Management Areas. Drainage from DMAs 1 & 2 discharge to a bio-retetion planter box, while drainage from DMAs 3, 4 & 5 are treated by a filter insert prior to discharge to the city storm drain system. DMA-1 DMA-2 DMA-3 DMA-4 DMA-5 TOTAL Total Area (ac) 0.141 0.093 0.039 0.015 0.057 0.345 Total Area (sf) 6,134 4,052 1,710 660 2,498 15,050 Impervious Area (sf) 5,820 3,794 1,194 660 1,698 13,166 Pervious Area (sf) 314 258 516 0 800 1,884 imp 0.95 0.94 0.70 1.0 0.68 0.87 C 0.86 0.85 0.68 0.90 0.66 0.80 d (in) 0.70 0.70 0.70 0.70 0.70 0.70 DCV (cf) 308 201 68 35 96 702 Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 13 IV.3 BMP SELECTION AND PROJECT CONFORMANCE ANALYSIS IV.3.1 Hydrologic Source Controls Name Included? Localized on-lot infiltration Impervious area dispersion (e.g. roof top disconnection) Street trees (canopy interception) Residential rain barrels (not actively managed) Green roofs/Brown roofs Blue roofs Impervious area reduction (e.g. permeable pavers, site design) Other: Impervious Dispersion and localized infiltration have not been used because of the site constraints and the soils geotechnical hazards associated with infiltration. The entire DCV is being addressed with the use of an enclosed bioretention planter box and storm drain filters. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 14 IV.3.2 Infiltration BMPs Infiltration BMPs to be used for this project are indicated in the table below. Implementation of said controls is discussed in the text that follows. Name Included? Bioretention without underdrains Rain gardens Porous landscaping Infiltration planters Retention swales Infiltration trenches Infiltration basins Drywells Subsurface infiltration galleries French drains Permeable asphalt Permeable concrete Permeable concrete pavers Other: Infiltration BMPs have not been used because of the soils geotechnical hazards associated with infiltration. The entire DCV is being addressed with the use of an enclosed bioretention planter box and storm drain filters. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 15 Infeasibility Criteria Yes No 1 Would Infiltration BMPs pose significant risk for groundwater related concerns? Refer to Appendix VII (Worksheet I) for guidance on groundwater-related infiltration feasibility criteria. X Provide basis: Silt/Clayey soils in not conducive to infiltration. 2 Would Infiltration BMPs pose significant risk of increasing risk of geotechnical hazards that cannot be mitigated to an acceptable level? (Yes if the answer to any of the following questions is yes, as established by a geotechnical expert): The BMP can only be located less than 50 feet away from slopes steeper than 15 percent The BMP can only be located less than eight feet from building foundations or an alternative setback. A study prepared by a geotechnical professional or an available watershed study substantiates that stormwater infiltration would potentially result in significantly increased risks of geotechnical hazards that cannot be mitigated to an acceptable level. X Provide basis: Silt/Clayey soils in not conducive to infiltration. 3 Would infiltration of the DCV from drainage area violate downstream water rights? X Provide basis: N/A Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 16 Table 2.7: Infiltration BMP Feasibility Worksheet (continued) Partial Infeasibility Criteria Yes No 4 Is proposed infiltration facility located on HSG D soils or the site geotechnical investigation identifies presence of soil characteristics which support categorization as D soils? X Provide basis: 5 Is measured infiltration rate below proposed facility less than 0.3 inches per hour? This calculation shall be based on the methods described in Appendix VII. X Provide basis: Clayey soils typically exhibit infiltration rates far less than 0.3 inches per hour. 6 Would reduction of over predeveloped conditions cause impairments to downstream beneficial uses, such as change of seasonality of ephemeral washes or increased discharge of contaminated groundwater to surface waters? X Provide citation to applicable study and summarize findings relative to the amount of infiltration that is permissible: No ephemeral washes or other groundwater sources discharging to surface waters exist downstream of the project. 7 Would an increase in infiltration over predeveloped conditions cause impairments to downstream beneficial uses, such as change of seasonality of ephemeral washes or increased discharge of contaminated groundwater to surface waters? X Provide citation to applicable study and summarize findings relative to the amount of infiltration that is permissible: No ephemeral washes or other groundwater sources discharging to surface waters exist downstream of the project. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 17 Table 2.7: Infiltration BMP Feasibility Worksheet (continued) Infiltration Screening Results (check box corresponding to result): 8 Is there substantial evidence that infiltration from the project would result in a significant increase in I&I to the sanitary sewer that cannot be sufficiently mitigated? (See Appendix XVII) Provide narrative discussion and supporting evidence: Summarize findings of studies provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. X 9 If any answer from row 1-3 is yes: infiltration of any volume is not feasible within the DMA or equivalent. Provide basis: Summarize findings of infeasibility screening X 10 If any answer from row 4-8 is yes, infiltration is permissible but is not presumed to be feasible for the entire DCV. Criteria for designing biotreatment BMPs to achieve the maximum feasible infiltration and ET shall apply. Provide basis: Summarize findings of infeasibility screening 11 If all answers to rows 1 through 10 are no, infiltration of the full DCV is potentially feasible, BMPs must be designed to infiltrate the full DCV to the maximum extent practicable. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 18 IV.3.3 Evapotranspiration, Rainwater Harvesting BMPs Name Included? All HSCs; See Section IV.3.1 Surface-based infiltration BMPs Other vegetated BMPs Above-ground cisterns and basins Underground detention Other: Since the project is fully treated using Bio-Retention planter box BMPs, utilization of Evapotranspiration and/or Rainwater Harvesting BMPs is not required. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 19 IV.3.4 Biofiltration BMPs Biofiltration BMPs to be used for this project are indicated in the table below. Implementation of said controls is discussed in the text that follows. Name Included? Bioretention with underdrains Stormwater planter boxes with underdrains Proprietary vegetated biotreatment systems Other: Treatment/Retention of runoff from DMA-1 and 2 is accomplished using a Bioretention Planter Box with underdrains. Roof runoff will be discharged directly into the enclosed bioretention planter boxes before reaching an underdrain pipe for discharge. The surface overflow within the planter boxes will be set 7.5” above grade. This will allow for surface ponding within the planter box to a depth of 7.5” above the surface. See Worksheet C calculations on following pages. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 20 DMA-1 Worksheet C: Capture Efficiency Method for Volume-Based, Constant Drawdown BMPs Step 1: Determine the design capture storm depth used for calculating volume 1 Enter design capture storm depth from Figure III.1, d (inches) d= 0.7 inches 2 Enter calculated drawdown time of the proposed BMP based on equation provided in applicable BMP Fact Sheet, T (hours) T= 3.0 hours 3 Using Figure III.2, determine the "fraction of design capture storm depth" at which the BMP drawdown time (T) line achieves 80% capture efficiency, X1 X1= 0.26 4 Enter the effect depth of provided HSCs upstream, dHSC (inches) (Worksheet A) dHSC= - inches 5 Enter capture efficiency corresponding to dHSC, Y2 (Worksheet A) Y2= - % 6 Using Figure III.2, determine the fraction of "design capture storm depth" at which the drawdown time (T) achieves the equivalent of the upstream capture efficiency(Y2), X2 X2= - 7 Calculate the fraction of design volume that must be provided by BMP, fraction = X1 - X2 fraction= 0.26 8 Calculate the resultant design capture storm depth (inches), dfraction= fraction × d dfraction= 0.182 inches 9 SOC Only: When using this method for biofiltration sizing, check that the resulting volume in ponding plus pore spaces is at least 0.75× the remaining DCV (after accounting for upstream HSC/retention BMPs). (See Worksheet SOC-1) Y / N / NA Step 2: Calculate the DCV 1 Enter Project area tributary to BMP (s), A (acres) A= 0.141 acres 2 Enter Project Imperviousness, imp (unitless) imp= 0.95 3 Calculate runoff coefficient, C= (0.75 x imp) + 0.15 C= 0.86 4 Calculate runoff volume, Vdesign= (C x drfraction x A x 43560 x (1/12)) Vdesign= 81 cu-ft Supporting Calculations Describe system: Enclosed Planter Box w/ 7.5” ponding depth, 3” mulch layer, 18” of top soil/planting mix, over pea gravel w/ a 6” diameter underdrain pipe. Total Proposed Planter Area per Figure II in Section VI of WQMP = 313 sq. ft. Vproposed = Aproposed* Ponding Depth (dp)  313 sq. ft. * 0.625 ft. = 195 cu-ft. …… The proposed enclosed planter box is sized to fully treat the calculated constant drawdown volume of 81 cu. ft. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 21 DMA-1 Worksheet C: Capture Efficiency Method for Volume-Based, Constant Drawdown BMPs Provide drawdown time calculations per applicable BMP Fact Sheet: DD = (dp / KMEDIA) * 12 in./ft.  DD = (0.625 / 2.5) * 12  DD = 3.0 hours where: KMEDIA = 2.5 in./hr (per TGD Appendix XIV-53, Capture Efficiency Method for Biotreatment) Graphical Operations Provide supporting graphical operations. See Example III.6. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 22 DMA-2 Worksheet C: Capture Efficiency Method for Volume-Based, Constant Drawdown BMPs Step 1: Determine the design capture storm depth used for calculating volume 1 Enter design capture storm depth from Figure III.1, d (inches) d= 0.7 inches 2 Enter calculated drawdown time of the proposed BMP based on equation provided in applicable BMP Fact Sheet, T (hours) T= 3.0 hours 3 Using Figure III.2, determine the "fraction of design capture storm depth" at which the BMP drawdown time (T) line achieves 80% capture efficiency, X1 X1= 0.26 4 Enter the effect depth of provided HSCs upstream, dHSC (inches) (Worksheet A) dHSC= - inches 5 Enter capture efficiency corresponding to dHSC, Y2 (Worksheet A) Y2= - % 6 Using Figure III.2, determine the fraction of "design capture storm depth" at which the drawdown time (T) achieves the equivalent of the upstream capture efficiency(Y2), X2 X2= - 7 Calculate the fraction of design volume that must be provided by BMP, fraction = X1 - X2 fraction= 0.26 8 Calculate the resultant design capture storm depth (inches), dfraction= fraction × d dfraction= 0.182 inches 9 SOC Only: When using this method for biofiltration sizing, check that the resulting volume in ponding plus pore spaces is at least 0.75× the remaining DCV (after accounting for upstream HSC/retention BMPs). (See Worksheet SOC-1) Y / N / NA Step 2: Calculate the DCV 1 Enter Project area tributary to BMP (s), A (acres) A= 0.093 acres 2 Enter Project Imperviousness, imp (unitless) imp= 0.94 3 Calculate runoff coefficient, C= (0.75 x imp) + 0.15 C= 0.85 4 Calculate runoff volume, Vdesign= (C x drfraction x A x 43560 x (1/12)) Vdesign= 53 cu-ft Supporting Calculations Describe system: Enclosed Planter Box w/ 7.5” ponding depth, 3” mulch layer, 18” of top soil/planting mix, over pea gravel w/ a 6” diameter underdrain pipe. Total Proposed Planter Area per Figure II in Section VI of WQMP = 257 sq. ft. Vproposed = Aproposed* Ponding Depth (dp)  257 sq. ft. * 0.625 ft. = 160 cu-ft. …… The proposed enclosed planter box is sized to fully treat the calculated constant drawdown volume of 53 cu. ft. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 23 Worksheet C: Capture Efficiency Method for Volume-Based, Constant Drawdown BMPs Provide drawdown time calculations per applicable BMP Fact Sheet: DD = (dp / KMEDIA) * 12 in./ft.  DD = (0.625 / 2.5) * 12  DD = 3.0 hours where: KMEDIA = 2.5 in./hr (per TGD Appendix XIV-53, Capture Efficiency Method for Biotreatment) Graphical Operations Provide supporting graphical operations. See Example III.6. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 24 IV.3.5 Hydromodification Control BMPs Hydromodification controls are not required for this project because Hydrologic Conditions of Concern do not exist for this project. See Section II.3. Hydromodification Control BMPs BMP Name BMP Description Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 25 IV.3.7 Non-structural Source Control BMPs Non-structural source control BMPs used for this project are described below. Non-Structural Source Control BMPs Identifier Name Check One If not applicable, state brief reason Included Not Applicable N1 Education for Property Owners, Tenants and Occupants N2 Activity Restrictions N3 Common Area Landscape Management No common areas present. N4 BMP Maintenance N5 Title 22 CCR Compliance (How development will comply) No hazardous waste. N6 Local Industrial Permit Compliance Not an industrial project. N7 Spill Contingency Plan No hazardous waste. N8 Underground Storage Tank Compliance No USTs on site. N9 Hazardous Materials Disclosure Compliance No hazardous waste. N10 Uniform Fire Code Implementation No hazardous waste. N11 Common Area Litter Control N12 Employee Training No employees. N13 Housekeeping of Loading Docks No loading docks exposed to storm water proposed. N14 Common Area Catch Basin Inspection N15 Street Sweeping Private Streets and Parking Lots No exterior parking areas. N16 Retail Gasoline Outlets None exist. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 26 IV.3.8 Structural Source Control BMPs Structural source control BMPs used for this project are described below. Structural Source Control BMPs Identifier Name Check One If not applicable, state brief reason Included Not Applicable S1 Provide storm drain system stenciling and signage No large catch basins on site to receive stenciling. S2 Design and construct outdoor material storage areas to reduce pollution introduction No outdoor MSAs. S3 Design and construct trash and waste storage areas to reduce pollution introduction S4 Use efficient irrigation systems & landscape design, water conservation, smart controllers, and source control S5 Protect slopes and channels and provide energy dissipation No proposed slopes or channels. Incorporate requirements applicable to individual priority project categories (from SDRWQCB NPDES Permit) S6 Dock areas None exist. S7 Maintenance bays None exist. S8 Vehicle wash areas None exist. S9 Outdoor processing areas None exist. S10 Equipment wash areas None exist. S11 Fueling areas None exist. S12 Hillside landscaping None exist. S13 Wash water control for food preparation areas None exist. S14 Community car wash racks None exist. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 27 IV.4 ALTERNATIVE COMPLIANCE PLAN (IF APPLICABLE) IV.4.1 Request of Waiver of LID BMPs N/A IV.4.2 Water Quality Credits Determine if water quality credits are applicable for the project. Refer to Section 7.II-3.2 of the Model WQMP for description of credits and TGD Appendix VI for calculation methods for applying WQ credits. Description of Proposed Project Project Types that Qualify for Water Quality Credits (Select all that apply): Redevelopment projects that reduce the overall impervious footprint of the project site. Brownfield redevelopment, meaning redevelopment, expansion, or reuse of real property which may be complicated by the presence or potential presence of hazardous substances, pollutants or contaminants, and which have the potential to contribute to adverse ground or surface WQ if not redeveloped. Higher density development projects which include two distinct categories (credits can only be taken for one category): those with more than seven units per acre of development (lower credit allowance); vertical density developments, for example, those with a Floor to Area Ratio (FAR) of 2 or those having more than 18 units per acre (greater credit allowance). Mixed use development, such as a combination of residential, commercial, industrial, office, institutional, or other land uses which incorporate design principles that can demonstrate environmental benefits that would not be realized through single use projects (e.g. reduced vehicle trip traffic with the potential to reduce sources of water or air pollution). Transit-oriented developments, such as a mixed use residential or commercial area designed to maximize access to public transportation; similar to above criterion, but where the development center is within one half mile of a mass transit center (e.g. bus, rail, light rail or commuter train station). Such projects would not be able to take credit for both categories, but may have greater credit assigned Redevelopment projects in an established historic district, historic preservation area, or similar significant city area including core City Center areas (to be defined through mapping). Developments with dedication of undeveloped portions to parks, preservation areas and other pervious uses. Developments in a city center area. Developments in historic districts or historic preservation areas. Live-work developments, a variety of developments designed to support residential and vocational needs together – similar to criteria to mixed use development; would not be able to take credit for both categories. In-fill projects, the conversion of empty lots and other underused spaces into more beneficially used spaces, such as residential or commercial areas. Calculation of Water Quality Credits (if applicable) This project does not qualify for the water quality credits listed above. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 28 IV.4.3 Treatment Control BMPs Treatment Control BMPs BMP Name BMP Description PRE-2 Channel Drain Filter Triton TDAM filter (model TDAM5-10Ht-REM-FOG.) for removal of pollutants including liquefied petroleum hydrocarbons (Fats, Oils & Grease including animal fats) and total suspend soils (TSS) such as trash, sediment, silt, vegetative debris. Use and Location: Inlet filtration devices are proposed as treatment for DMAs that cannot be routed into the bio- retention planter boxes. Locations of proposed treatment control BMPs are shown on the BMP exhibit in Section VI. Performance: See specification sheets in Attachment D. Sizing: See Worksheet D (Capture Efficiency Method for Flow-Based BMPs) for pretreatment device capacity calculations at the end of this section. Worksheet D: Capture Efficiency Method for Flow-Based BMPs Step 1: Determine the design capture storm depth used for calculating volume 1 Enter the time of concentration, Tc (min) (See Appendix IV.2) Tc= 5 2 Using Figure III.4, determine the design intensity at which the estimated time of concentration (Tc) achieves 80% capture efficiency, I1 I1= 0.26 in/hr 3 Enter the effect depth of provided HSCs upstream, dHSC (inches) (Worksheet A) dHSC= - inches 4 Enter capture efficiency corresponding to dHSC, Y2 (Worksheet A) Y2= - % 5 Using Figure III.4, determine the design intensity at which the time of concentration (Tc) achieves the upstream capture efficiency(Y2), I2 I2= - 6 Determine the design intensity that must be provided by BMP, I- design= I1-I2 Idesign= 0.26 Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 29 Step 2: Calculate the design flowrate 1 Enter Project area tributary to BMP (s), A (acres) A= See supporting Calculations 2 Enter Project Imperviousness, imp (unitless) imp= 3 Calculate runoff coefficient, C= (0.75 x imp) + 0.15 C= 4 Calculate design flowrate, Qdesign= (C x idesign x A) Qdesign= Supporting Calculations Filter A idesign i100 imp C Qdesign Qfiltered1 Q100 Qoverflow1 ID sf ac in/hr in/hr gpm gpm gpm gpm DMA-3 1,710 0.039 0.26 6.19 0.7 0.68 - - - - DMA-4 660 0.015 0.26 6.19 1 0.9 - - - - DMA-5 2,498 0.057 0.26 6.19 0.68 0.66 - - - - Provide time of concentration assumptions: Tc of 5-minutes is the minimum allowed and provides the most conservative design. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 30 Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section IV Page 31 IV.4.4 Regional/Sub-Regional LID BMPs This project will not participate in Regional/Sub-Regional LID BMPs since the full DCV can be treated using LID BMPs. Regional/Sub-Regional LID BMPs IV.4.5 Other Alternative Compliance Measures This project will not make use of other alternative compliance measures since the full DCV can be treated using LID BMPs. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section VI Page 32 Section V Inspection/Maintenance Responsibility for BMPs BMP Inspection/Maintenance BMP Reponsible Party(s) Inspection/ Maintenance Activities Required Minimum Frequency of Activities BIO-1 Bio-retention with underdrains (Enclosed Planter Box) Owner or contracted maintenance personnel Visual Inspection, keep free of debris, perform more thorough inspection after storm events. Media (Gravel & soils mixtures) Replacement every 5-10 years 1” – 2” of mulch to be added On-going during rainy season; and, periodically during the summer months. Media (Gravel & soils mixtures) Replacement every 5-10 years 1” - 2” of mulch to be added annually N-11 Litter Control Owner or contracted maintenance personnel Remove and properly dispose of litter. Weekly N-14 Catch Basin Inspection Owner or contracted maintenance personnel Inspect catch basins and grates. Remove accumulated debris. Weekly S-3 Trash & Waste Storage Area Owner or contracted maintenance personnel Clean waste storage areas. Weekly. S-4 Efficient Irrigation Owner or contracted maintenance personnel Ensure proper operation of all system components and replace as required. Weekly. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section VI Page 33 Section VI Site Plan and Drainage Plan VI.1 SITE PLAN AND DRAINAGE PLAN Include a site plan and drainage plan sheet set containing the following minimum information: • Project location • Site boundary • Land uses and land covers, as applicable • Suitability/feasibility constraints • Structural BMP locations • Drainage delineations and flow information • Drainage connections • BMP details VI.2 ELECTRONIC DATA SUBMITTAL The minimum requirement is to provide submittal of PDF exhibits in addition to hard copies. Format must not require specialized software to open. Water Quality Management Plan (WQMP) 1526 Placentia, Newport Beach, California Cefalia Development Section VII Page 34 Section VII Educational Materials Refer to the Orange County Stormwater Program (ocwatersheds.com) for a library of materials available. For the copy submitted to the Permittee, only attach the educational materials specifically applicable to the project. Other materials specific to the project may be included as well and must be attached. Education Materials Residential Material (http://www.ocwatersheds.com) Check If Applicable Business Material (http://www.ocwatersheds.com) Check If Applicable The Ocean Begins at Your Front Door Tips for the Automotive Industry Tips for Car Wash Fund-raisers Tips for Using Concrete and Mortar Tips for the Home Mechanic Tips for the Food Service Industry Homeowners Guide for Sustainable Water Use Proper Maintenance Practices for Your Business Household Tips Compliance BMPs for Mobile Businesses Proper Disposal of Household Hazardous Waste Other Material Check If Attached Recycle at Your Local Used Oil Collection Center (North County) Recycle at Your Local Used Oil Collection Center (Central County) Recycle at Your Local Used Oil Collection Center (South County) Tips for Maintaining a Septic Tank System Responsible Pest Control Sewer Spill Tips for the Home Improvement Projects Tips for Horse Care Tips for Landscaping and Gardening Tips for Pet Care Tips for Projects Using Paint (N 89°42'00" E 105.00') (N 0 0 ° 1 8 ' 0 0 " W 2 0 . 0 0 ' ) (N 89°42'00" E 45.00') (N 0 0 ° 1 8 ' 0 0 " W 1 2 2 . 5 0 ' ) (N 0 0 ° 1 8 ' 0 0 " W 1 0 2 . 5 0 ' ) (N 89°42'00" E 150.00') HC PARKING STRUCTURE 1 STORY COMMERCIAL BUILDING RIGHT OF WAY LINE PL A C E N T I A A V E N U E NO PARKING T/SLAB=99.56 WQMP LEGEND PROPOSED BUILDING PROPOSED LANDSCAPE PROPOSED HARDSCAPE RUNOFF FLOW DIRECTION DETAIL TRITON TDAM FILTER SERIES - TDAM5 - 10"Ht. BMP TABLE INLET/ CHANNEL DRAIN TRENCH DRAIN FILTER DOWNSPOUT DRAINAGE SYSTEM 1 3 9 A v e n i d a N a v a r r o S a n C le m e n t e , C A 9 2 6 7 2 9 4 9 .4 9 2 .8 5 8 6 w w w.to ale n g i n ee ri n g .co m C I V I L E N G I N E E R I N G L A N D S U R V E Y I N G STO RMWA TE R Q UA LI TY DETAIL STORMWATER PLANTER BOX PLANTER WALL STRUCTURAL DESIGN BY OTHERS UNDER SEPARATE PLAN & PERMIT BIO-RETENTION PLANTER BOX