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HomeMy WebLinkAbout20190423_Memo for ReviewPreliminary Water Quality Management Plan (pWQMP) 215 RIVERSIDE AVENUE Por. Lot D, Tract No. 919 APN 049-103-17 Newport Beach, California Prepared for: CANNERY PARTNERS LLC 660 Newport Center Drive, Suite 200 Newport Beach, CA 92660 Contact: Gary Jabara (949) 999-4545 Prepared by: TOAL ENGINEERING, INC. 139 Avenida Navarro, San Clemente, CA 92672 www.toalengineering.com Contact: ADAM L. TOAL, R.C.E. 59275 (949) 492-8586 atoal@toalengineering.com Prepared on: FEBRUARY 7, 2019 Template Prepared: December 20, 2013 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Owner’s Certification Project Owner’s Certification Permit/Application No. xxxx-2019 Grading Permit No. xxxx-2019 Tract/Parcel Map No. Lot D Tract No. 919 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. Gary Jabara 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: Gary Jabara Title Company Cannery Partners LLC Address 660 Newport Center Drive, Suite 200, Newport Beach, CA 92660 Email gary@mobilitie.com Telephone # 949-999-4545 Signature Date Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 D Tract No. 919 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) Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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): 16,290 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 2,815 17 13,475 83 Post-Project Conditions 5,140 32 11,150 68 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). Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 from the front portion of the property will be directed to a gravel bed for infiltration prior to discharge to the street. Runoff from the remaining portions of the site will be collected in an area drain system and discharged into the existing street through drain box filter at the rear of the property and then pumped up to the street for discharge. 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: Cannery Partners, LLC Gary Jabara 660 Newport Center Dr., Suite 200 Newport Beach, CA 92660 Tel: (949) 999-4545 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section III Page 7 Section III Site Description III.1 Physical Setting Planning Area/ Community Name N/A Location/Address 215 Riverside Avenue, Newport Beach, California Project Area Description The subject property lies on the northwesterly corner of the intersection of Riverside Avenue and Avon Street. Land Use RSD-A: Single Unit Residential Detached (0.0-5.9 DU/AC) Zoning CG-05: Commercial General Acreage Property: 16,290 s.f. (0.374 acres) Project: 14,470 s.f. (0.332 acres) Predominant Soil Type Per the O.C. Hydrology Manual Plate B, the project is underlain by soil Type D. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section III Page 8 III.2 Site Characteristics Precipitation Zone 0.7-in (TGD Fig XVI-1) Topography The subject property is sloed commercial lot. Elevations on the developed portion of the site range from a maximum of about 43-feet to a minimum of about 16-feet. Drainage Patterns/Connections Under existing conditions, the runoff from the site flows to the streets at the east (Riverside) and south (Avon) 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. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 × 0.77 +0.15 =0.73 𝑑𝑑= 0.70 𝑖𝑖𝑖𝑖. 𝐴𝐴= 14,470 𝑠𝑠𝑠𝑠.𝑓𝑓𝑓𝑓. 𝐷𝐷𝐷𝐷𝐷𝐷=0.73 x 0.70 𝑖𝑖𝑖𝑖.x 14,470 𝑠𝑠.𝑓𝑓.x �1 𝑓𝑓𝑓𝑓.12 𝑖𝑖𝑖𝑖.�=616 𝑐𝑐𝑓𝑓 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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= 0.332 acres 2 Enter Project Imperviousness, imp (unitless) imp= 0.77 3 Calculate runoff coefficient, C= (0.75 x imp) + 0.15 C= 0.73 4 Calculate runoff volume, Vdesign= (C x dremainder x A x 43560 x (1/12)) Vdesign= 616 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 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 Precise Grading Plan shows the proposed grading, site improvements, and retaining walls necessary for construction of a single-family residence. 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) There is one (1) Drainage Management Area (DMA) for this commercial development. The following LID BMP will be used to meet the calculated Design Volume for the DMA: - Bioretention with Underdrain (Biotreatment BMP) DM A Area (sq. ft.) % Impervious BMP Type Sizing 1 14,470 0.77 BIO-1: Bioretention w/ Underdrain SWQDV See discussion for the selected BMP in Section IV.3. See the WQMP Site Plan provided in Section VI of this report for DMA location and characteristics. The GIS coordinates for all BMPs are nearly identical at: 33.6219, -117.9237. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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: It is believed that infiltration will not be feasible for this project due to the Type “D” site soils. Further analysis will be done when the soils report becomes available. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section IV Page 15 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). Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 0.332 ac 7 What is the acreage of impervious area? IA 0.256 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 0.256 = 0.215 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: Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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: DMA 1 utilizes a Biotreatment BMP as LID treatment for this project. DMA-1 includes the entire project. The proposed bioretention w/ underdrain systems features: a 3” mulch layer underlain by 24” thick section of soil media (with an infiltration rate of 2.5”/hr. (min.)) and a 12” thick section of gravel. Above the media surface is a ponding depth of 12 inches, with inlets provided at the design ponding depth to provide collection for runoff volumes exceeding the capacity of the system. A 6” diameter, perforated underdrain pipe is provided near the base of the gravel layer for collection of storm water passing through the system. The required volume storage determined using Worksheet C (see Attachment B), with the results summarized below: DMA-1: 202 cu. ft. (205 sq. ft. surface area w/ 12” ponding depth) The BMP Fact Sheet for BIO-1: Bioretention with Underdrain is also provided in Attachment B. See the WQMP Site Plan in Section VI for DMA drainage areas, BMP locations, and BMP detail. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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 TRT-2 Media Filter Kristar Flogard Catch Basin Filter Insert (Model FGP- 24F) The Filter removes Hydrocarbons, oil, grease, trash and sediment and debris. See Spec Sheet on Attachment F Use and Location The indoor parking garage will not be directed to the Bioretention planter box for treatment. Because it is indoor, there is no runoff tributary to this area, however, drain inlets in the garage can collect contaminated water from cars that enter the garage. Therefore, the drains in the garage will be fitted with treatment filters. Locations of proposed treatment control BMPs are shown on the BMP Exhibit in Section VI. Performance The provided Filter insert performance (See Filter Insert Spec page on Attachment D) provides treatment for the pollutants of concern. Specifically: Trash and Debris removal Hydrocarbons (Oil, Grease, Pesticide) 80% Removal Sediment (TSS) 86% Removal Grease, Pesticide) 80% Removal Sediment Removal Pathogen/microorganism removal (Coliforms, Enterococcus) Sizing See Worksheet D (Capture Efficiency Method for Flow-Based BMPs) calculations on the following page. The design flow rate of 0.015 cfs is fully treated by the proposed Kristar FloGard Catch Basin Filter insert FGP-12F which has a treatment capacity of 0.25 cfs (See Spec sheet in Attachment C). Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA 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= - 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, Idesign= I1-I2 Idesign= 0.26 Step 2: Calculate the design flowrate 1 Enter Project area tributary to BMP (s), A (acres) A= 0.128 acres 2 Enter Project Imperviousness, imp (unitless) imp= 0.64 3 Calculate runoff coefficient, C= (0.75 x imp) + 0.15 C= 0.63 4 Calculate design flowrate, Qdesign= (C x idesign x A) Qdesign= 0.021 cfs Supporting Calculations The design flowrate for the lot that is using the filter insert is 0.021 The provided Kristar FloGard filter Insert (FGP-12F) provides 0.25 cfs of filtered flow……OK Provide time of concentration assumptions: Tc of 5-minutes is the minimum allowed and provides the most conservative design. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section IV Page 27 Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section IV Page 28 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) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section VI Page 29 Section V Inspection/Maintenance Responsibility for BMPs An Operation and Maintenance Plan will be included with the final WQMP. Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section VI Page 30 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) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section VI Page 31 Figure VI.1. Vicinity Map. Source: maps.google.com SITE Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section VI Page 32 Figure VI.2. Aerial Image. Source: maps.google.com SITE Water Quality Management Plan (WQMP) 215 Riverside Avenue, Newport Beach, California MR. GARY JABARA Section VII Page 33 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