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HomeMy WebLinkAbout20190319_WQMP-Prelim-02-07-2019Preliminary Water Quality Management Plan (pWQMP) PICKUP RESIDENCE 23 Harbor Island Lot 23, Tract No. 802 Newport Beach, California Prepared for: MR. TODD PICKUP c/o Ritner Group Newport Beach, CA 92663 (949) 999-3255 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 atoal@toalengineering.com Prepared on: FEBRUARY 7, 2019 Template Prepared: December 20, 2013 PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Owner’s Certification Project Owner’s Certification Permit/Application No. xxxx-2019 Grading Permit No. xxxx-2019 Tract/Parcel Map No. Lot 23 Tract No. 802 Building Permit No. (TBD) CUP, SUP, and/or APN (Specify Lot Numbers if Portions of Tract) 049-103-17 This Water Quality Management Plan (WQMP) has been prepared for Mr. Todd Pickup 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: Todd Pickup Title Company Address Email Telephone # Signature Date PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP 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 ............................................................................................. 7 Section IV Best Management Practices (BMPs) ............................................................. 10 Section V Inspection/Maintenance Responsibility for BMPs .......................................... 29 Section VI Site Plan and Drainage Plan ......................................................................... 31 Section VII Educational Materials .................................................................................. 34 Attachments Attachment A . .........................................................................................BMP Fact Sheets Attachment B . ................................................................................. Educational Materials Attachment C . .................................................................. Operation & Maintenance Plan PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section I Page 3 Section I Discretionary Permit(s) and Water Quality Conditions Project Infomation Permit/Application No. xxxx-2019 Tract/Parcel Map No. Lot 23 Tract No. 802 Additional Information/ Comments: Water Quality Conditions Water Quality Conditions (list verbatim) None. 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) PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section II Page 4 Section II Project Description II.1 Project Description Description of Proposed Project Development Category (Verbatim from WQMP): 5. Impervious surface of 2,500 square feet or more located within, directly adjacent to (within 200 feet), or discharging directly into receiving waters within Environmentally Sensitive Areas (ESAs). 8. 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): 7,793 Number of Dwelling Units: 1 SIC Code: n/a Narrative Project Description: The project consists of the following: (1) demolition of the existing building and associated parking areas; (2) construction of a new retail space along with a 2-level parking garage and appurtenant hardscape, landscape, and drainage improvements. Project Area Pervious Impervious Area (sf) Percentage Area (sf) Percentage Pre-Project Conditions 1,173 15 6,620 85 Post-Project Conditions 1,083 14 6,710 86 Drainage Patterns/Connections See Section III.2. 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 Conceptual/Preliminary and/or Project Water Quality Management Plans (TGD). PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section II Page 5 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 PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section II Page 6 II.3 Hydrologic Conditions of Concern 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. 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 discharged into a bottomless trench drain at the front of the property after passing through a trench drain with filter insert for pretreatment of the roof runoff. Overflow drainage during storm events will be allowed to spill over the top of the trench drain and to the flow line and existing inlets at the centerline of Harbor Island Road. The drainage system is shown on the Preliminary Grading and Drainage Plan and the Preliminary Water Quality Management Plan for the project. II.5 Property Ownership/Management This property is privately owned by: Todd Pickup c/o Ritner Group Newport Beach, CA 92663 Tel: (949) 999-3255 PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section III Page 7 Section III Site Description III.1 Physical Setting Planning Area/ Community Name N/A Location/Address 23 Harbor Island, Newport Beach, California Project Area Description The subject property lies on the southerly side of Harbor Island Land Use RSD-A: Single Unit Residential Detached (0.0-5.9 DU/AC) Zoning R-1 (Residential) Acreage Property: 7,793 s.f. (0.179 acres) Predominant Soil Type Per the O.C. Hydrology Manual Plate B, the project is underlain by soil Type D. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section III Page 8 III.2 Site Characteristics Precipitation Zone 0.7-in (TGD Fig XVI-1) Topography The subject property is flat residential lot. Elevations on the developed portion of the site range from a maximum of about 13-feet to a minimum of about 9-feet. Drainage Patterns/Connections Under existing conditions, the majority of the runoff from the site flows to the street at the north of the property. A portion of the rear yard is allowed to flow towards the bay to the south of the property. Soil Type, Geology, and Infiltration Properties Per the O.C. Hydrology Manual Plate B, the project is underlain by soil Type D. Hydrogeologic (Groundwater) Conditions A soils report is not available at this time. Geotechnical Conditions (relevant to infiltration) According to infiltration BMP feasibility criteria, infiltration of the entire DVC is not feasible for this project. 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. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section III Page 9 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. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 10 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 × 0.86 + 0.15 = 0.80 𝑑𝑑= 0.70 𝑖𝑖𝑖𝑖. 𝐴𝐴= 7,793 𝑠𝑠𝑠𝑠.𝑓𝑓𝑓𝑓. 𝐷𝐷𝐷𝐷𝐷𝐷=0.80 x 0.70 𝑖𝑖𝑖𝑖.x 7,783 𝑠𝑠.𝑓𝑓.x �1 𝑓𝑓𝑓𝑓.12 𝑖𝑖𝑖𝑖.�=364 𝑐𝑐𝑓𝑓 PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 11 Worksheet B: Simple Design Capture Volume Sizing Method 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= 0.70 inches 2 Enter the effect of provided HSCs, dHSC (inches) (Worksheet A) dHSC= - inches 3 Calculate the remainder of the design capture storm depth, dremainder (inches) (Line 1 – Line 2) dremainder= 0.70 inches Step 2: Calculate the DCV 1 Enter Project area tributary to BMP (s), A (acres) A= 0.179 acres 2 Enter Project Imperviousness, imp (unitless) imp= 0.86 3 Calculate runoff coefficient, C= (0.75 x imp) + 0.15 C= 0.80 4 Calculate runoff volume, Vdesign= (C x dremainder x A x 43560 x (1/12)) Vdesign= 364 cu-ft Step 3: Design BMPs to ensure full retention of the DCV Step 3a: Determine design infiltration rate 1 Enter measured infiltration rate, Kmeasured (in/hr) (Appendix VII) Kmeasured= In/hr 2 Enter combined safety factor from Worksheet H, Sfinal (unitless) Sfinal= 3 Calculate design infiltration rate, Kdesign = Kmeasured / Sfinal Kdesign= In/hr Step 3b: Determine minimum BMP footprint 4 Enter drawdown time, T (max 48 hours) T= Hours 5 Calculate max retention depth that can be drawn down within the drawdown time (feet), Dmax = Kdesign x T x (1/12) Dmax= feet 6 Calculate minimum area required for BMP (sq-ft), Amin = Vdesign/ dmax Amin= sq-ft PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP 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 BMP Site Plan in Section VI of this report. The project Grading and Drainage Plan shows the proposed grading, drainage improvements, and site improvements associated with construction of the proposed mixed-use commercial/residential building. Site Design Practices The project incorporates Site Design practices as follows: • Minimize Impervious Area – although the subject property lies in a densely developed mixed-use area with similar development and space constraints preclude the use of some site design practices, the proposed project does the following to minimize impervious area: o Increases the pervious area fraction of the subject property. o Utilizes multi-floor buildings • 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 consists of one Drainage Management Area, DMA-1. Drainage from DMA-1 ultimately discharges into the Alley at the northerly property boundary after being treated by a filter insert and an infiltration trench. DMA-1 Total Area (sf) 7,793 Impervious Area (sf) 6,710 Pervious Area (sf) 1,083 imp 0.86 C 0.80 d (In) 0.7 DCV (cf) 364 PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 13 IV.3 BMP SELECTION AND PROJECT CONFORMANCE ANALYSIS Each sub-section below documents that the proposed design features conform to the applicable project performance criteria via check boxes, tables, calculations, narratives, and/or references to worksheets. IV.3.1 Hydrologic Source Controls The Hydrologic Source Controls 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? 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: Hydrologic Source Controls have not been used due to space constraints, including landscape area size and proximity to structure foundations. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP 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: Description An infiltration trench will be provided along the northerly property boundary as shown on the BMP Site Plan in Section VI. Although the infiltration trench is located in DMA-1, the trench will be sized for the DCV for the entire project area. Sizing Per City of Newport Beach prescriptive requirement: “One 15’ long French drain per maximum of 2,000 sf of impervious area”. Gravel volume for City standard trench drain = 1.0 c. f. gravel volume/ft. trench length 𝑇𝑇𝑇𝑇𝑇𝑇𝑖𝑖𝑐𝑐ℎ 𝑔𝑔𝑇𝑇𝑔𝑔𝑔𝑔𝑇𝑇𝑔𝑔 𝑔𝑔𝑣𝑣𝑔𝑔.𝑇𝑇𝑇𝑇𝑠𝑠′𝑑𝑑=𝑖𝑖𝑖𝑖𝑖𝑖.𝑔𝑔𝑇𝑇𝑇𝑇𝑔𝑔 × 15′𝑓𝑓𝑇𝑇𝑇𝑇𝑖𝑖𝑐𝑐ℎ 𝑔𝑔𝑇𝑇𝑖𝑖𝑔𝑔𝑓𝑓ℎ2,000 𝑠𝑠.𝑓𝑓.𝑖𝑖𝑖𝑖𝑖𝑖.𝑔𝑔𝑇𝑇𝑇𝑇𝑔𝑔 × 1.0 𝑐𝑐.𝑓𝑓.𝑔𝑔𝑇𝑇𝑔𝑔𝑔𝑔𝑇𝑇𝑔𝑔 𝑔𝑔𝑣𝑣𝑔𝑔.𝑓𝑓𝑓𝑓.𝑓𝑓𝑇𝑇𝑇𝑇𝑖𝑖𝑐𝑐ℎ 𝑔𝑔𝑇𝑇𝑖𝑖𝑔𝑔𝑓𝑓ℎ 𝑇𝑇𝑇𝑇𝑇𝑇𝑖𝑖𝑐𝑐ℎ 𝑔𝑔𝑇𝑇𝑔𝑔𝑔𝑔𝑇𝑇𝑔𝑔 𝑔𝑔𝑣𝑣𝑔𝑔.𝑇𝑇𝑇𝑇𝑠𝑠′𝑑𝑑= 6,710 𝑠𝑠.𝑓𝑓.× 15 𝑓𝑓𝑓𝑓.2,000 𝑠𝑠.𝑓𝑓. × 1.0 𝑐𝑐.𝑓𝑓.𝑓𝑓𝑓𝑓.=𝟓𝟓𝟎𝟎.𝟑𝟑𝟑𝟑 𝒄𝒄.𝒇𝒇. Gravel volume provided for this project: 28’L x 24”W x 24”D = 112 c.f. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 15 Feasibility Infiltration Feasibility documentation are included at the end of this subsection and Attachment E. Table 2.7: Infiltration BMP Feasibility Worksheet 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: Infiltration BMPs will not pose a significant risk to local groundwater. Groundwater in the vicinity of the project site is not used for drinking water. Pretreatment devices will mitigate entry of trash, sediment, and oil & grease into proposed infiltration BMPs. 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: 3 Would infiltration of the DCV from drainage area violate downstream water rights? X Provide basis: There are no downstream water right holders since site drainage is conveyed via the city storm drain system directly to receiving waters (Lower Newport Bay). PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP 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: Proposed facility is located on HSG-A soils per OCHM Soil Maps. 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: Infiltration rate is presumed to be greater than 0.3 inches per hour based on site’s HSG. 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 downstream beneficial uses such as ephemeral washes or groundwater sources of drinking water are located downstream of the subject property. 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 downstream beneficial uses such as ephemeral washes or groundwater sources of drinking water are located downstream of the subject property. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP 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: No evidence of I&I has been provided by the local sewer agency (City of Newport Beach). No 9 If any answer from row 1-3 is yes: infiltration of any volume is not feasible within the DMA or equivalent. Provide basis: 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: 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. X PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 18 IV.3.3 Evapotranspiration, Rainwater Harvesting BMPs Evapotranspiration and/or Rainwater Harvesting 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? All HSCs; See Section IV.3.1 Surface-based infiltration BMPs Other vegetated BMPs Above-ground cisterns and basins Underground detention Other: The project site does not have an irrigation demand large enough to justify partial capture for irrigation demand. See Worksheet J from Section X of the TGD on the following page. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 19 Worksheet J: Summary of Harvested Water Demand and Feasibility 1 What demands for harvested water exist in the tributary area (check all that apply): 2 Toilet and urinal flushing □ 3 Landscape irrigation □ 4 Other:_______________________________________________________ □ 5 What is the design capture storm depth? (Figure III.1) d .70 inches 6 What is the project size? A 0.179 ac 7 What is the acreage of impervious area? IA 0.154 ac For projects with multiple types of demand (toilet flushing, irrigation demand, and/or other demand) 8 What is the minimum use required for partial capture? (Table X.6) gpd 9 What is the project estimated wet season total daily use (Section X.2)? gpd 10 Is partial capture potentially feasible? (Line 9 > Line 8?) For projects with only toilet flushing demand 11 What is the minimum TUTIA for partial capture? (Table X.7) 12 What is the project estimated TUTIA? 13 Is partial capture potentially feasible? (Line 12 > Line 11?) For projects with only irrigation demand 14 What is the minimum irrigation area required based on conservation landscape design? (Table X.8) 0.84 x 0.154 = 0.129 ac 15 What is the proposed project irrigated area? (multiply conservation landscaping by 1; multiply active turf by 2) 0.076 ac 16 Is partial capture potentially feasible? (Line 15 > Line 14?) No Provide supporting assumptions and citations for controlling demand calculation: PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 20 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: Biotreatment BMPs were not considered for this project since the full DCV will be addressed by infiltration BMPs. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 21 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 PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 22 IV.3.6 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 No common areas present. N12 Employee Training No employees. N13 Housekeeping of Loading Docks No loading docks exposed to storm water proposed. N14 Common Area Catch Basin Inspection No common areas present. N15 Street Sweeping Private Streets and Parking Lots No exterior parking areas. N16 Retail Gasoline Outlets None exist. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 23 IV.3.7 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 Drain inlets on private property. 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. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 24 IV.4 ALTERNATIVE COMPLIANCE PLAN (IF APPLICABLE) IV.4.1 Request of Waiver of LID BMPs Provide documentation of feasibility analysis if implementation of LID BMPs is technically infeasible. Refer to Section 7.II-3.1 in the Model WQMP. Calculate the amount of remaining obligation that must be met with alternative compliance (See TGD Appendix VI). 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. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 25 IV.4.3 Treatment Control BMPs Since the project is fully treated using Infiltration BMPs, utilization of Treatment Control BMPs is not required. Treatment Control BMPs BMP Name BMP Description PRE-2 Catch Basin Insert Oldcastle Precast Flogard +Plus Trench Drain Filter (Model FG-TDOF8) for removal of gross solids, trash and debris, and petroleum hydrocarbons. Used for filtration of roof and parking lot runoff prior to entering trench drain. Use and Location Inlet filtration devices will be used as pre-treatment for infiltration BMPs or and for proposed roof drains that cannot be routed to an infiltration BMP. 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. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 26 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= 0.00 inches 4 Enter capture efficiency corresponding to dHSC, Y2 (Worksheet A) Y2= 0 % 5 Using Figure III.4, determine the design intensity at which the time of concentration (Tc) achieves the upstream capture efficiency(Y2), I2 I2= 0.00 6 Determine the design intensity that must be provided by BMP, Idesign= I1-I2 Idesign= 0.26 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 Type † A idesign i100 imp C Qdesign Qfiltered1 Q100 Qoverflow1 ID sf ac in/hr in/hr gpm gpm gpm gpm 4 B 2706 0.0621 0.26 - 1 0.9 6.52 224 - - † Filter Type legend: B = Oldcastle Precast Flogard +Plus Trench Drain Filter Model FG-TDOF8 1 Filtered and overflow capacity provided by manufacturer. Provide time of concentration assumptions: Tc of 5-minutes is the minimum allowed and provides the most conservative design. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section IV Page 27 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. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section VI Page 28 Section V Inspection/Maintenance Responsibility for BMPs An Operation and Maintenance Plan will be included with the final WQMP. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section VI Page 29 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. PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section VI Page 30 Figure VI.1. Vicinity Map. Source: maps.google.com SITE PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section VI Page 31 Figure VI.2. Aerial Image. Source: maps.google.com SITE PA2019-051 Water Quality Management Plan (WQMP) 23 Harbor Island, Newport Beach, California MR. TODD PICKUP Section VII Page 32 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 PA2019-051