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CC - Item 3A - Attachment H - Appendix I. Preliminary LID PlanPRELIMINARY LOW IMPACT DEVELOPMENT (LID) REPORT TENTATIVE TRACT NO. 82875 3133-3141 Willard Avenue Rosemead, CA 91770 Prepared for: THE OLSON COMPANY 3010 Old Ranch Parkway, Suite 100 Seal Beach, CA 92740-2751 (562) 596-4770 Prepared by: ALAN R. SHORT, P.E. 25911 Pinewood Lane Laguna Hills, CA 92653 (949) 586-5200 Date Prepared: September 30, 2019 PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 AUGUST 5, 2017 ROSEMEAD TENTATIVE TRACT NO. 82875 i TABLE OF CONTENTS SECTION PAGE I. INTRODUCTION .................................................................................................................. 1 II. EXISTING SITE AND WATERSHED DESCRIPTION ................................................................. 3 SITE DESCRIPTION............................................................................................................... 3 GEOTECHNICAL CONDITIONS ............................................................................................. 3 WATERSHED DESCRIPTION ................................................................................................. 4 III. PROJECT DESCRIPTION ....................................................................................................... 6 IV. SITE ASSESSMENT AND DESIGN CONSIDERATIONS ......................................................... 12 SOURCE CONTROL BMPS .................................................................................................. 16 SITE DESIGN BMPS ............................................................................................................ 17 VI. STORMWATER QUALITY CONTROL MEASURES ............................................................... 18 STORMWATER QUALITY DESIGN CALCULATIONS ............................................................ 20 DESIGN STANDARDS FOR STORMWATER QUALITY CONTROL MEASURES/LID BMPS ..... 22 STORMWATER QUALITY CONTROL MEASURES/LID BMP SIZING..................................... 22 VII. HYDROLOGIC CONDITIONS OF CONCERN ........................................................................ 24 VIII. STORMWATER QUALITY CONTROL MEASURE MAINTENANCE ........................................ 25 RESPONSIBLE PARTY ......................................................................................................... 25 MAINTENANCE PLAN ........................................................................................................ 26 IX. APPENDICES ...................................................................................................................... 27 Appendix 1: Hydrocalc Calculations Appendix 2: Geotechnical/Infiltration Report Appendix 3: Modular Wetlands System O&M Manual Appendix 4: Source Control BMP Fact Sheets Appendix 5: Public Education Materials Appendix 6: Master Covenant and Agreement (placeholder for Final LID Report only) PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 AUGUST 5, 2017 ROSEMEAD TENTATIVE TRACT NO. 82875 ii OWNER CERTIFICATION LOW IMPACT DEVELOPMENT PLAN This Low Impact Development Report has been prepared for The Olson Company, by ALAN R. SHORT, P.E. It is intended to comply with the requirements of the County of Los Angeles National Pollution Discharge Elimination Permit (Order No. R4-2012-0175-A01) issued by the Los Angeles Regional Water Quality Control Board. The undersigned is authorized to approve implementation of the provisions of this plan as appropriate and will strive to have the plan carried out by successors consistent with the City of Rosemead Low Impact Development Ordinance and the intent of the NPDES storm water program requirements. I certify under penalty of law that this document and all attachments were prepared under my jurisdiction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering the information, to the best of my knowledge and belief, the information submitted is true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Signature Date Name Title THE OLSON COMPANY 3010 Old Ranch Parkway, Suite 100 Seal Beach, CA 92740-2751 (562) 596-4770 PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 AUGUST 5, 2017 ROSEMEAD TENTATIVE TRACT NO. 82875 1 INTRODUCTION I. INTRODUCTION This LID Report covers the post-construction operations on Tentative Tract No. 82875, in the City of Rosemead, California (see Figure 1, Vicinity Map). It has been developed as required under State Water Resources Control Board (SWRCB) Municipal NPDES Storm Water Permit for the County of Los Angeles and the Incorporated Cities of Los Angeles County, the County of Los Angeles Department of Public Works Low Impact Development Standards Manual dated February 2014 (LID Standards Manual), and in accordance with good engineering practices. This LID Report shall identify, at a minimum, the routine resources specified in the City of Rosemead Low Impact Development Ordinance and the County of Los Angeles Department of Public Works Low Impact Development Standards Manual, which details implementation of Low Impact Development (LID) BMPs whenever they are applicable to a project; the assignment of long-term maintenance responsibilities; and show the Design Plan that will be implemented in order to mitigate post-construction stormwater runoff pollution. PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 2 Figure 1 Vicinity Map (3133-3141 Willard Avenue) PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 3 II. EXISTING SITE AND WATERSHED DESCRIPTION SITE DESCRIPTION The site is located at 3133, 3141 & 3149 Willard Avenue in the city of Rosemead, California. The site is bordered by single-family residences to the north and south, Willard Avenue to the east, and a utility easement to the west. The location of the site and its relationship to the surrounding areas are shown on Figure 1, Vicinity Map. The site is irregular in shape and comprises approximately 1.19 acres of land. The site is currently occupied by two one-story residential buildings. The residential building at the northeast corner of the site is unoccupied. Remnants of building foundations were also observed at certain portions of the site. Other site improvements include a detached garage and a storage shed. Under existing conditions, the site is approximately 9.2% impervious (see page 8). Topography within the site varies with elevations of approximately 263 to 266 feet above mean sea level (MSL), based on google earth. Site drainage is via sheet flow directed to east toward Willard Avenue. Vegetation within the site consist of grass and medium size trees scattered throughout the site. SOIL CONDITIONS & INFILTRATION CHARACTERISTICS Soils encountered at the site consist of artificial fill materials overlying alluvial deposits. The artificial fill materials typically consist of brown silty sand. The artificial fill was typically moist and loose to medium dense. Pores were observed within the central and western portions of the site. The maximum thickness of the fill encountered varied from approximately 5 to 6 feet below existing grades. The project site is comprised of Soil Group No. 007 soils, according to the Los Angeles County Department of Public Works web-based Hydrology Map (http://dpw.lacounty.gov/wrd/hydrologygis/) The alluvial deposits were encountered below the artificial fill materials to the maximum depth of exploration, 51.5 feet below the ground surface. The alluvial deposits consisted predominantly of coarse-grained material and with occasional layers of fine-grained material at depth. The coarse-grained material was typically brown sand with varying amounts of silt. A review of the CDMG Seismic Hazard Zone Report 024 indicates that historical high groundwater levels for the general site area is as shallow as 10 feet below the existing ground surface. Groundwater was not encountered during this firm’s subsurface exploration to the maximum depth explored, approximately 51.5 feet below the existing ground surface. Existing groundwater in the past 10 years has fluctuated from 60 to 95 feet below the existing ground surface. It is therefore concluded that groundwater can at least be as shallow as 60 feet below the existing ground surface. Percolation testing was performed on May 2, 2019, in general conformance with the constant- head test procedures outlined in the referenced Well Permeameter Method (USBR 7300-89). Based on the subsurface exploration and percolation testing, infiltration of storm water is not considered to be feasible due to the estimated permeability being less than 0.3 in/hr, at 0.22 in/hr PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 4 and less than 0.09 in/hr in the tests performed. Percolation characteristics of site soils are not anticipated to meet the minimum requirements of the Los Angeles County guidelines. This is likely attributed to the presence of fine-grained material throughout the subsurface materials. Although the subsurface materials can be considered a silty sand, pockets of cohesive materials were observed. The infiltration study is provided in Appendix 2. WATERSHED DESCRIPTION The proposed project resides within the Los Angeles River Watershed, which covers an area of approximately 834 square miles. The watershed encompasses and is shaped by the path of the Los Angeles River, which flows from its headwaters in the mountains eastward to the northern corner of Griffith Park. Here the channel turns southward through the Glendale Narrows before it flows across the coastal plain and into San Pedro Bay near Long Beach. The Los Angeles River has evolved from an uncontrolled, meandering river providing a valuable source of water for early inhabitants to a major flood protection waterway. The proposed project discharges south into the City MS4 along Willard Avenue. The storm drain then ties into the line at Garvey Avenue flowing east. This line then discharges into the Rio Hondo Channel approximately 1.3 miles from the project site. The Rio Hondo Channel then flows southwest until it reaches the Los Angeles River approximately 15 miles downstream. Los Angeles River Watershed Management Area is 303(d) listed for Ammonia, Coliform Bacteria, Copper, Lead, Nutrients, Oil, and Trash. Of those pollutants, Trash, Nutrients/Ammonia, Lead, Copper, and Bacteria are addressed in TMDLs that have been established and approved by USEPA. The proposed project, therefore, must minimize these pollutants of concern should they be anticipated or expected from the project’s land use. PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 5 Los Angeles County Storm Drain System (https://pw.lacounty.gov/fcd/StormDrain/index.cfm) PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 6 III. PROJECT DESCRIPTION The proposed Tentative Tract 82875 project will develop 29 single-family attached residential units on the 1.20-acre property. There will be 8 buildings with a T-shaped driveway providing six uncovered surface parking stalls and one handicap space. Under proposed conditions, the project site will be approximately 74.7% impervious, an increase from 9.2% impervious in existing conditions. The proposed project will generally be drained via area drains as well as curb and gutter flows along the drive aisles of the property to drop inlet catch basins. Storm water runoff flows will generally drain in a southeasterly direction towards Willard Avenue. Prior to discharge offsite, the LID stormwater runoff flows will be treated by a Modular Wetlands System (MWS-L-8-16) proprietary biofiltration BMP that will be in the south side front setback area between Residential Unit #7 and Willard Avenue. For peak flow detention, approximately 50 feet of 60-inch diameter HDPE pipe will be located at north side front setback area between Residential Unit #6 and Willard Avenue. LID treated flows and peak flows will be discharged via storm drain tie-in to the existing 48-inch RCP LACDPW storm drain along Willard Avenue. An HOA will be formed upon project completion. All driveways within the project site are considered private, to be maintained by the HOA. All storm water BMPs specified in this LID Report will also be maintained by the HOA. There are no trash enclosures or community trash bins, as each individual homeowner will be responsible for their respective homes, with regularly scheduled trash pickup at each home. TTRTRP2P2TRTRP2P215RUP15RUP CABLEELECF.R .TRTRTR15RUP15RUPCABLEELECF.R.P1P5P1XP4P3P5P1P5P1XP4P3TRTR P2P2TR TRP2 P2 TRTR P2P2P1P515RUP15RUPCABLEELECF.R.P1XTRTRP4P3P5TRTR P2P21BLDG 2002BLDG 3003BLDG 1004BLDG 1005BLDG 1006BLDG 1007BLDG 1008BLDG 100WILLARD AVEMin. 8' Side Setback RequiredMin. 20' FrontSetbackRequiredMin. 8' Side Setback RequiredMin. 8' Side Setback Required100’ Setback fromHigh VoltagePower LinesMin. 20' RearSetbackRequiredADA Accessible Path13'-0"20'-0"30'-0" 26'-0"8'-0"10'-0"100'-0"6'-0"6'-0"30'-0"26'-0" 20'-0" 28'-6" 9'-0" 13'-0"24'-0"7'-6"12'-5"8'-0" 5'-0"9'-4"Open Space "E" 931 SQ. FT.Open Space "B"2645 SQ. FT.Open Space "A" 2849 SQ. FT.EXISTING RESIDENTIALEXISTING RESIDENTIALOpen Space "C"2315 SQ. FT.8'-11"Open Space "D"1376 SQ. FT.26' Fire Laneand HammerheadArchitecture + Planning17911 Von Karman Ave,Suite 200Irvine, CA 92614949.851.2133ktgy.com#ROSEMEAD - WILLARD & GARVEYRosemead, CA2018-1210The Olson Company3010 Old Ranch Parkway,Suite 100Seal Beach, CA 90704Plot Date:09.25.20190102040SCALE: 1"=20'-0"A1.0CONCEPTUALSITE PLAN PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 12 IV. SITE ASSESSMENT AND DESIGN CONSIDERATIONS When implementing storm water control measures for a project, the project is required to provide treatment to remove pollutants of concern for the project. The BMP matrix labeled Table 7.3 on the following page lists the land use categories and their pollutants of concern for the Los Angeles River Watershed. This report is responsible for determining, evaluating, and selecting the appropriate and applicable measures to treat the targeted pollutants to the MEP standard. One or a combination of two or more suggested LID/treatment control BMPs can be selected as deemed applicable. The proposed project is considered a High-Density Single-Family Residential land use at 24.2 Dwelling Units per acre. The anticipate pollutants for the project include suspended solids, total phosphorus, copper, lead, and zinc. See table 7.3 below. Based on the TMDLs and 303(d) listed impairments for the Los Angeles River Watershed, the projects primary pollutants of concern are, therefore, (1) nutrients, (2) trash, and (3) oil and grease, and (4) metals. LID Report treatment control BMPs must address these pollutants to the MEP. PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 13 BMP MATRIX TABLES FOR LID REPORT PROJECT CATEGORIES (Excerpted from County of Los Angeles Department of Public Works, Low Impact Development Standards Manual, February 2014) PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 14 PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 15 PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 16 SOURCE CONTROL BMPS Source control BMPs are required to be incorporated in all new development and redevelopment projects unless not applicable. The table below indicates all BMPs to be incorporated in the project. For those designated as not applicable (N/A), a brief explanation why is provided. The specific source control BMPs for the Tentative Tract No. 82875 Project include: INCORPORATED SOURCE CONTROL BMP: YES N/A DESCRIPTION Storm Drain Message and Signage (S-1) Inlets will be stenciled with the appropriate message. Outdoor Material Storage Area (S-2) None proposed. Outdoor Trash Storage/Waste Handling Area (S-3) None proposed. Outdoor Loading/Unloading Dock Area (S-4) None proposed. Outdoor Vehicle/Equipment Repair/Maintenance Area (S-5) None proposed. Outdoor Vehicle/Equipment/ Accessory Wash Area (S-6) None proposed. Fuel & Maintenance Area (S-7) None proposed. Landscape Irrigation Practices (S-8) Efficient irrigation systems and smart controllers are proposed. Building Materials (S-9) None proposed. Animal Care and Handling Facilities (S-10) None proposed. Outdoor Horticulture Areas (S-11) None proposed. The following source control BMP fact sheets are provided in Appendix 4 of this report as a reference to the design plans and/or specifications for the Tentative Tract No. 82875 Project: · Storm Drain Message and Signage (S-1) · Landscape Irrigation Practices (S-8) PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 17 SITE DESIGN BMPS The following table describes the site design BMPs used in this project and the methods used to incorporate them. Careful consideration of site design is a critical first step in storm water pollution prevention from new developments and redevelopments. SITE DESIGN PRINCIPLES DESIGN CONSIDERED: SPECIFIC BMP YES NO DESCRIPTION Site Planning Building roof runoff will be directed to landscaping prior to discharge onto pavement or into area drains. Protect and Restore Natural Areas There are no natural areas to conserve. Site is already developed. Minimize Land Disturbance The project site is in an area that is considered built-out and is on an existing developed property. Minimize Impervious Area Approximately 10,000 square feet of common open space is provided, contributing to the majority of the 25.3% pervious area (0.3 acres) for the project. PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 18 VI. STORMWATER QUALITY CONTROL MEASURES This section describes the storm water quality control measures or LID BMPs proposed to treat the project site’s storm water runoff. Low Impact Development (LID) BMPs are required in addition to site design measures and source controls to reduce pollutants in stormwater discharges. LID BMPs are engineered facilities that are designed to retain or biofilter runoff on the project site. The Los Angeles County MS4 Stormwater Permit (Order No. R4-2012-0715) requires the evaluation and use of LID features using the following hierarchy of treatment: infiltration, harvest/reuse, and biofiltration. The design storm, from which the SWQDv is calculated, is defined as the greater of:  The 0.75-inch, 24-hour rain event; or  The 85th percentile, 24-hour rain event as determined from the Los Angeles County 85th percentile precipitation isohyetal map.1 Per the Los Angeles County 85th percentile precipitation isohyetal map, the 85th percentile, 24- hour storm event is 0.9-inch (see Figure 2). BMPs selected for the site shall rely on infiltration, bioretention, rainfall storage and reuse, and/or biofiltration, as feasible. In addition, any biofiltration features will be designed to biofiltrate 1.5 times the portion of the SWQDv that is not retained onsite (1.35-inch storm). INFILTRATION BMP FEASIBILITY As described in Section II, the soil percolation tests conducted on the site found infiltration rates of 0.22 in/hr and 0.09 in/hr. Since the measured rates fall below the LID Standards Manual’s minimum requirement for feasibility of 0.3 inches per hour, infiltration on the project site is therefore considered infeasible. Infiltration test results are included in Appendix 2. STORMWATER CAPTURE & REUSE FEASIBILITY In accordance with the County of Los Angeles Low Impact Development Standards Manual (LID Standards Manual), storage and reuse shall be considered should infiltration be determined infeasible. Since the primary use of captured runoff is for subsurface drip irrigation purposes, the proposed onsite irrigation demand was calculated for wet season months (October through April) to evaluate reuse feasibility. Demand requirements were calculated based on the proposed landscaping area, 1.19 acres (74.7% site imperviousness), and compared with the minimum LID design capture runoff volume of 2,700 ft3 for the project site. At a minimum, storage and reuse BMPs must be designed and maintained to ensure adequate capacity is available to capture the stormwater quality design volume (SWQDv) within 3 days (72 hours) of a likely storm event. The evaluation performed herein is derived from City of Los Angeles feasibility screening guidelines for capture and use, which initially screens to see if the 7-month wet season irrigation demand (ETWU7-month) is more than the LID design volume or SWQDv. Once this threshold is met, a final determination is made by assessing the estimated daily average water usage during the wet season, to ensure that there is enough irrigation demand from the project 1 County of Los Angeles Department of Public Works. (2004, February). Analysis of 85th Percentile 24-hour Rainfall Depth Analysis within the County of Los Angeles (February 2004). Retrieved September 30, 2019, from http://ladpw.org/wrd/hydrologygis/ PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 19 site during the rainy season to effectively utilize and draw down the SWQDv during a 72-hour period.2 Based on the initial screening method, storage and reuse of stormwater runoff is considered potentially feasible since the SWQDv ≤ ETWU7-month. See calculations below. Given for Proposed Project: Impervious Area 0.89 acres Pervious Area 0.30 acres Total Tributary Area 1.19 acres Total Site Irrigated Area 13,068 ft2 ETo Wet Season (Oct-April) 21.7 (Los Angeles area)3 = ET7 Planting Factor (PF) 0.5 = Medium Planting Type, moderate water use. Step 1: Calculate the Design Volume in Gallons (for 72-hour holding time) SWQDv = 2,700 ft3 x 7.48 gal/ft3 = 20,196 gallons Step 2: Determine Planter Factor Planter Factor (PF) = Planting Factor x Irrigated Area = 0.5 x 13,068 ft2 = 6,534 ft2 Step 3: Determine the 7-Month (Oct 1 – April 30) Estimated Total Water Use (ETWU) Wet Season Estimated Total Water Use (ETWU7-month) = ET7 x 0.62 x PF = 21.7 x 0.62 x 6,534 ft2 = 87,908 gallons Step 4: Determine if Captured Volume is Equal or Less Than Irrigation Demand (ETWU) Is SWQDv ≤ ETWU7-month? Yes – Demand (ETWU7-month) is greater than SWQDv. Storage and reuse is potentially feasible. STORAGE & REUSE FEASIBILITY SCREENING SUMMARY Project Acreage Irrigated Area SWQDv Plant Factor (PF) 7-Month ETWU Meets Initial Screening Criteria? 1.19 13,068 ft2 20,196 gal. 6,534 ft2 87,908 gal. Yes 2 City of Los Angeles Department of Public Works, Watershed Protection Division. (2011, June). Development Best Management Practices Handbook Low Impact Development Manual Part B Planning Activities. 4th Edition. 3 Reference Evapotranspiration (ETo) Table from City of Los Angeles Irrigation Guidelines (Local Implementation of AB 1881). PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 20 Despite the feasibility screening resulted in stormwater storage and reuse being potentially feasible, it is necessary to determine that the Stormwater Quality Design Volume can be adequately drawn down within 72 hours in order for it to be implemented on the project. This is determined by estimating the daily average water demand during the wet season. Since the ETWU7-month is approximately 87,908 gallons, the average daily water demand is roughly 410 gallons per day (214 days). Over a 72 hour period, it appears that the daily average water usage during the wet season is insufficient to utilize and draw down the onsite SWQDv, since the total water demand is 820 gallons, assuming that the first 24 hours after a rain event there is no water demand. Only 4% of the onsite SWQDv (820 gallons of 20,196 gallons) would be used for irrigation of the landscaped area within the project site over a 72-hour period, with approximately 19,376 gallons remaining in storage and unutilized. A significant amount of runoff treatment would be bypassed should a subsequent storm event follow shortly after the first. Therefore, stormwater runoff storage and reuse is considered not feasible. BIOFILTRATION Due to the infeasibility of the project site for retention, the project site will be treated by biofiltration, with a Modular Wetlands System (MWS-L-8-16) proprietary BMP. The entire 1.19- acre property will be treated by the MWS unit and, therefore, the project site has one Drainage Area. The table below provides the retention and biofiltration (1.5x) volumes and flow-rates for the project site under proposed conditions. BMPs selected for the project must be sized to provide the equivalent or greater treatment capacities than the listed volumes/flow-rates below. Calculations were performed utilizing the hydrologic calculator “HydroCalc” developed by the Los Angeles County Department of Public Works. HydroCalc completes the full Modified Rational Method (MODRAT) calculation process and produces the peak stormwater runoff flow rates and volumes for single subareas. Detailed calculations for the proposed treatment control BMPs, based on the HydroCalc tool, are provided in Appendix 1 of this report. STORMWATER QUALITY DESIGN CALCULATIONS Since stormwater retention is infeasible at the project site due to measured infiltration rates being less than 0.3 inches/hour, the project will rely on biofiltration to treat the LID volume. As such, the LID volume/rate to biofilter will be expressed as 1.5 times what would otherwise be retained. The Hydrocalc calculations for the proposed Tract No. 82875 project site is summarized below. SUMMARY OF STORMWATER QUALITY DESIGN CALCULATIONS Drainage Area Acres Imp. Ratio Soil No. Slope Length (ft) Slope Tc (min) Storm Depth 1.5x (in.) 1.5x LID SWQDv (ft3) 1.5x LID flow rate (cfs) 1 1.19 0.75 007 335 0.0107 17 1.35 4,048 0.378 PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 21 Figure 2 Project Site Predominant Soil Type Number = 007 | 85th Percentile, 24-hr Rainfall = 0.9 inch PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 22 DESIGN STANDARDS FOR STORMWATER QUALITY CONTROL MEASURES/LID BMPS The Modular Wetlands System (MWS) proprietary biofiltration BMP is a flow-based treatment system. As such, the project is required to treat a minimum of the 0.378 cfs. The various MWS sizes are provided in the table below, along with their respective treatment flow rates. STORMWATER QUALITY CONTROL MEASURES/LID BMP SIZING LID BMPs are sized based on the tributary area draining to them. Based on the project site’s grading and drainage design, the property is comprised of one drainage area that covers the entire 1.19-acre site. Therefore, the drainage area’s LID flow rate is equivalent to the project’s design flow rate of 0.378 cfs. For this reason, an MWS-L-8-16 unit with a treatment flow rate capacity of 0.462 cfs is prescribed. See Section III LID Schematic Exhibit and MWS-L-8-16 standard detail below for further details. STANDARD DETAIL STORMWATER BIOFILTRATION SYSTEM MWS-L-8-16-V PLAN VIEW ELEVATION VIEW RIGHT END VIEW LEFT END VIEW GENERAL NOTES INSTALLATION NOTES SITE SPECIFIC DATA PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 24 VII. HYDROLOGIC CONDITIONS OF CONCERN There are no hydrologic conditions of concern for the project site. The project does not drain into a natural drainage system. It drains to to the Rio Hondo Channel at Whittier Narrows Dam and ultimately to the Los Angeles River. All downstream channels are considered engineered channels with concrete side slopes. Therefore, the project will not have any hydromodification impacts to any downstream channels and is exempt from hydromodification requirements. PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 25 VIII. STORMWATER QUALITY CONTROL MEASURE MAINTENANCE RESPONSIBLE PARTY It has been determined that The Olson Company (owner) shall assume all BMP inspection and maintenance responsibilities for the Tract No. 82875 Project until an HOA is established. An HOA will be established for the property and the Owner will transition to an HOA Corporation. The Owner will be responsible for maintenance of all storm drain inlets, collectors, v-ditches or any other related flood control or storm water control device. Furthermore, all interior streets and/or roadways, landscape, recreation areas, facilities and/or open space within the project limits will be maintained by the Owner. Long-term funding for BMP maintenance will be provided by the Owner or HOA. Maintenance will be funded through HOA fees. RESPONSIBLE PARTY CONTACT INFORMATION Name: The Olson Company Contact: Tom Moore, Senior Director of Operations Address: 3010 Old Ranch Parkway, Suite 100 Seal Beach, CA 92740-2751 Phone: (562) 596-4770 Email: PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 26 MAINTENANCE PLAN Proper O&M is an important element of a stormwater mitigation plan to ensure BMPs remove pollution effectively. Routine maintenance or service also contributes to the efficiency and continuous operation of a system. The post development BMP maintenance responsibility and frequency matrix provided in this section detail the specific party to perform the inspection and maintenance of each BMP for the Tentative Tract No. 82875 Project and details the maintenance and inspection activities to be performed, and the frequency with which each shall be performed. Structural BMP Maintenance Responsibility / Frequency Matrix BMP Responsibility Maintenance Frequency Catch Basin Cleaning Owner / HOA Minimum Frequency: Catch basin/storm drain inlets within the project site will be cleaned out at least once per year, prior to the rainy season (October 1). Storm Drain Stenciling Owner / HOA Minimum Frequency: Storm drain inlet stenciling and signage will be inspected for legibility at least once per year. Any illegible stencils/signage will be replaced immediately. Modular Wetlands System (MWS-L-8-16) Owner / HOA Minimum Frequency: 1x per Year. The MWS unit shall be maintained in accordance with manufacturer’s specifications provided in Appendix 3. HPDE Underground Detention Pipe Owner/HOA Minimum Frequency: 1x per Year. The underground detention system for peak flow mitigation shall be inspected through the risers annually and after major storm events, and cleaned at a minimum of once per year, prior to the start of the rainy season (October 1st). Cleaning and maintenance will be performed per manufacturer specifications and will typically include removal of any trash and debris and excess sediment within the pipes. Sediment shall be removed when deposits approach within 6 inches of the invert heights of the connecting pipe or inlet structures. PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 27 IX. APPENDICES Appendix 1: Hydrocalc Calculations Appendix 2: Geotechnical / Infiltration Report Appendix 3: Modular Wetlands System O&M Manual Appendix 4: Source Control BMP Fact Sheets Appendix 5: Public Education Materials Appendix 6: Master Covenant and Agreement (Placeholder for Final LID Report) PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 APPENDIX 1 HYDROCALC CALCULATIONS PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 APPENDIX 2 GEOTECHNICAL / INFILTRATION REPORT September 19, 2019 J.N.: 2783.00 Mr. Steve Armanino The Olson Company 3010 Old Ranch Parkway, Suite 100 Seal Beach, California 90740 Subject: Infiltration Study for Storm Water Quality, Proposed Multi-Family Residential Development, 3133, 3141 & 3149 Willard Avenue, Rosemead, California. Dear Mr. Armanino, Albus-Keefe & Associates, Inc. has completed a geotechnical investigation of the site for evaluation of the percolation characteristics of the site soils. The scope of this investigation consisted of the following: • Exploratory drilling, soil sampling and percolation test well installation • Field percolation testing • Laboratory testing of selected soil samples • Engineering analysis of the data • Preparation of this report SITE DESCRIPTION AND PROPOSED DEVELOPMENT Site Location and Description The site is located at 3133, 3141 & 3149 Willard Avenue in the city of Rosemead, California. The site is bordered by single-family residences to the north and south, Willard Avenue to the east, and a utility easement to the west. The location of the site and its relationship to the surrounding areas are shown on Figure 1, Site Location Map. The site is irregular in shape and comprises approximately 1.2 acres of land. The site is currently occupied by two one-story residential buildings. The residential building at the northeast corner of the site is unoccupied. Remnants of building foundations were also observed at certain portions of the site. Other site improvements include a detached garage and a storage shed. Topography within the site varies with elevations of approximately 263 to 266 feet above mean sea level (MSL), based on google earth. Site drainage is via sheet flow directed to east toward Willard Avenue. Vegetation within the site consist of grass and medium size trees scattered throughout the site. The Olson Company September 19, 2019 J.N.: 2783.00 Page 2 ALBUS-KEEFE & ASSOCIATES, INC. © 2018 Google N SITE LOCATION MAP The Olson Company Proposed Residential Development 3133, 3141 & 3149 Willard Avenue Rosemead, California NOT TO SCALE FIGURE 1 SITE Loca tion The Olson Company September 19, 2019 J.N.: 2783.00 Page 3 ALBUS-KEEFE & ASSOCIATES, INC. Proposed Development We understand the site will be developed for residential use consisting of 29 units of three- story townhomes. It is anticipated that all proposed structures will be constructed on grade (i.e. no subterranean elements). Associated interior driveways, perimeter/retaining walls, underground utilities and a storm water infiltration system are also planned. No grading or structural plans were available in preparing of this report. However, we anticipate that minor rough grading of the site will be required to achieve future surface configuration and we expect the proposed residential dwellings will be wood-framed structures with concrete slabs on grade yielding relatively light foundation loads. SUMMARY OF FIELD AND LABORATORY WORK Subsurface Investigation Subsurface exploration for this investigation was conducted at the site on April 30, 2019 and consisted of drilling three (3) exploratory borings. The borings were drilled to maximum depths of approximately 51.5 feet below the existing ground surface utilizing a truck-mounted, hollow-stem- auger drill rig. Representatives of Albus-Keefe & Associates, Inc. logged the exploratory excavations. Visual and tactile identifications were made of the materials encountered, and their descriptions are presented on the Exploration Logs in Appendix A. The approximate locations of the exploratory excavations completed by this firm are shown on the enclosed Geotechnical Map, Plate 1. Bulk, relatively undisturbed and Standard Penetration Test (SPT) samples were obtained at selected depths within the exploratory boring for subsequent laboratory testing. Relatively undisturbed samples were obtained using a 3-inch O.D., 2.5-inch I.D., California split-spoon soil sampler lined with brass rings. SPT samples were obtained from the boring using a standard, unlined SPT soil sampler. During each sampling interval, the sampler was driven 18 inches with successive drops of a 140-pound automatic hammer falling 30 inches. The number of blows required to advance the sampler was recorded for each six inches of advancement. The total blow count for the lower 12 inches of advancement per soil sample is recorded on the exploration log. Samples were placed in sealed containers or plastic bags and transported to our laboratory for analyses. The borings were backfilled with auger cuttings upon completion of sampling. In addition, two percolation test boring, P-1 and P-2, were also excavated to an approximate depth of 25 and 10 feet in the vicinity of exploratory boring B-1 for subsequent percolation testing. The percolation test well was later backfilled with auger cuttings upon completion of testing. Percolation Testing Percolation testing was performed on May 2, 2019, in general conformance with the constant-head test procedures outlined in the referenced Well Permeameter Method (USBR 7300-89). A water hose attached to a water source on site was connected to an inline flowmeter to measure the water flow. The flowmeter is capable of measuring flow rates up to 13 gallons per minute and as low as 0.06 gallons per minute. A valve was connected in line with the flowmeter to control the flow rate. The Olson Company September 19, 2019 J.N.: 2783.00 Page 4 ALBUS-KEEFE & ASSOCIATES, INC. A filling hose was used to connect the flowmeter and the test well. Water was then introduced by the filling hose near the bottom of the test well. A water level meter with 1/100-foot divisions was used to measure the depths to water surface from the top of well casings. Flow to the well was terminated upon either completion of testing of all the pre-determined water levels or if the flow rate exceeded the maximum capacity of the flowmeter. Measurements obtained during the percolation testing are provided on Appendix C, Plates C-1 and C-2. Laboratory Testing Selected soil samples of representative earth materials were tested to assist in the formulation of conclusions and recommendations presented in this report. Tests consisted of in-situ moisture content and dry density, and grain-size analysis. Results of laboratory testing relevant to percolation characteristics are presented in the Appendix B. ANALYSIS OF DATA Subsurface Conditions Descriptions of the earth materials encountered during our investigation are summarized below and are presented in detail on the Exploration Logs presented in Appendix A. Soils encountered at the site consist of artificial fill materials overlying alluvial deposits. The artificial fill materials typically consist of brown silty sand. The artificial fill was typically moist and loose to medium dense. Pores were observed within the central and western portions of the site. The maximum thickness of the fill encountered varied from approximately 5 to 6 feet below existing grades. Deeper fills associated with the previously existing improvements may also be present on site. The alluvial deposits were encountered below the artificial fill materials to the maximum depth of exploration, 51.5 feet below the ground surface. The alluvial deposits consisted predominantly of coarse-grained material and with occasional layers of fine-grained material at depth. The coarse- grained material was typically brown sand with varying amounts of silt. These deposits are slightly moist to moist and loose to very dense. The fine-grained material consisted of brown clay and silt. These deposits are typically was typically moist and very stiff. The upper alluvium was also observed to contain pores within the central and western portions of the site. Groundwater A review of the CDMG Seismic Hazard Zone Report 024 indicates that historical high groundwater levels for the general site area is as shallow as 10 feet below the existing ground surface. Groundwater was not encountered during this firm’s subsurface exploration to the maximum depth explored, approximately 51.5 feet below the existing ground surface. A review of the Los Angeles County monitoring well database indicates well number 2924E is approximately 0.4 miles to the southeast with data indicating historic groundwater has been in a downward trend since 1957. Existing groundwater in the past 10 years has fluctuated from 60 to 95 feet below the existing The Olson Company September 19, 2019 J.N.: 2783.00 Page 5 ALBUS-KEEFE & ASSOCIATES, INC. ground surface. It is therefore concluded that groundwater can at least be as shallow as 60 feet below the existing ground surface. Percolation Data An analysis was performed to evaluate permeability using the flow rate obtained at the end of the constant-head stage of field percolation testing. The analysis was performed in accordance with the procedures provided in the referenced USBR 7300-89. The procedure essentially uses a closed-form solution to the percolation out of a small-diameter well. Using this method, we calculated a composite permeability value for the head condition maintained in each well. Since the flow to the well was less than the lower limit of our equipment, the minimum flow rate of the equipment was used. The result is summarized in Table 1 below and the supporting analysis is included in Appendix C, Plates C-3 and C-4. TABLE 1 Summary of Back-Calculated Permeability Coefficient Location Total Depth of Well (ft) Depth to Water in Well (ft) Height of Water in Well (ft) Static Flow Rate (gal./min.) Estimated Permeability, ks (in/hr.) P-1 25.0 20.0 5.0 0.15 0.22 P-2 10.0 5.0 5.0 < 0.06 < 0.09 CONCLUSIONS AND RECOMMENDATIONS Based on the subsurface exploration and percolation testing at 3133, 3141 & 3149 Willard Avenue, infiltration of storm water is not considered to be feasible due to the estimated permeability being less than 0.3 in/hr (less than 10-6 m/s). Percolation characteristics of site soils are not anticipated to meet the minimum requirements of the Los Angeles County guidelines. This is likely attributed to the presence of fine-grained material throughout the subsurface materials. Although the subsurface materials can be considered a silty sand, pockets of cohesive materials were observed. LIMITATIONS This report is based on the geotechnical data as described herein. The materials encountered in our boring excavations and utilized in our laboratory testing for this investigation are believed representative of the project area, and the conclusions and recommendations contained in this report are presented on that basis. However, soil and bedrock materials can vary in characteristics between points of exploration, both laterally and vertically, and those variations could affect the conclusions and recommendations contained herein. As such, observations by a geotechnical consultant during the construction phase of the storm water infiltration systems are essential to confirming the basis of this report. The Olson Company September 19, 2019 J.N.: 2783.00 Page 6 ALBUS-KEEFE & ASSOCIATES, INC. This report has been prepared consistent with that level of care being provided by other professionals providing similar services at the same locale and time period. The contents of this report are professional opinions and as such, are not to be considered a guaranty or warranty. This report should be reviewed and updated after a period of one year or if the site ownership or project concept changes from that described herein. This report has been prepared for the exclusive use of The Olson Company to assist the project consultants in the design of the proposed development. This report has not been prepared for use by parties or projects other than those named or described herein. This report may not contain sufficient information for other parties or other purposes. This report is subject to review by the controlling governmental agency. We appreciate this opportunity to be of service to you. If you should have any questions regarding the contents of this report, please do not hesitate to call. Sincerely, ALBUS-KEEFE & ASSOCIATES, INC. Mark Principe Paul Hyun Jin Kim Staff Engineer Associate Engineer P.E. 77214 Enclosures: Plate 1- Geotechnical Map Appendix A - Exploratory Logs Appendix B – Relevant Soil Laboratory Testing Appendix C - Percolation Testing and Analyses The Olson Company September 19, 2019 J.N.: 2783.00 Page 7 ALBUS-KEEFE & ASSOCIATES, INC. REFERENCES Publications and Reports California Department of Conservation, Division of Mines and Geology, Seismic Hazard Report 027, “Seismic Hazard Zone Report for the El Monte 7.5-Minute Quadrangles, Los Angeles County, California”, 1998. “Procedure for Performing Field Permeability Testing by the Well Permeameter Method”, United States Department of The Interior, Bureau of Reclamation (USBR 7300-89). Saxton, K.E., W.J. Rawls, J.S. Romberger, and R.I. Papendick. 1986, “Estimating generalized soil- water characteristics from texture”, Soil Sci. Soc. Am. J. 50(4):1031-103 WILLARD AVE.PROJECT SITE LIMITSB-1B-2B-3P-1P-2EARL AVE.- Exploratory BoringEXPLANATION(Locations Approximate)ALBUS-KEEFE & ASSOCIATES, INC.GEOTECHNICAL CONSULTANTSGEOTECHNICAL MAP2783.00Job No.:Date:Plate:105/14/190 20 40 80APPROX SCALE : 1" = 40'- Exploratory Percolation Test Boring ALBUS-KEEFE & ASSOCIATES, INC. APPENDIX A EXPLORATORY LOGS Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lith- ology Blows Per Foot Moisture Content (%) Dry Density (pcf) Other Lab Tests Laboratory TestsSamples Material Description E X P L O R A T I O N L O G WaterCoreBulk5 10 15 20 EXPLANATION Solid lines separate geologic units and/or material types. Dashed lines indicate unknown depth of geologic unit change or material type change. Solid black rectangle in Core column represents California Split Spoon sampler (2.5in ID, 3in OD). Double triangle in core column represents SPT sampler. Vertical Lines in core column represents Shelby sampler. Solid black rectangle in Bulk column respresents large bag sample. Other Laboratory Tests: Max = Maximum Dry Density/Optimum Moisture Content EI = Expansion Index SO4 = Soluble Sulfate Content DSR = Direct Shear, Remolded DS = Direct Shear, Undisturbed SA = Sieve Analysis (1" through #200 sieve) Hydro = Particle Size Analysis (SA with Hydrometer) 200 = Percent Passing #200 Sieve Consol = Consolidation SE = Sand Equivalent Rval = R-Value ATT = Atterberg Limits Albus-Keefe & Associates, Inc.Plate A-1 Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lith- ology Blows Per Foot Moisture Content (%) Dry Density (pcf) Other Lab Tests Laboratory TestsSamples Material Description E X P L O R A T I O N L O G Rosemead (Willard & Garvey) 3122 Delta Pl, Rosemead, CA 91770 2783.00 4/30/2019 MPHollow-Stem Auger The Olson Company B-1 271.5 WaterCoreBulk140 lbs / 30 in 5 10 15 20 ARTIFICIAL FILL (Af) Silty Sand (SM): Dark brown, moist, medium dense, fine to medium grained sand, organics, trace fine grained sand, pores, pocket of sand @ 4 ft, loose, increased sand, no pores ALLUVIUM (Qal) Silty Sand (SM): Light reddish brown, moist, loose, fine to medium grained sand, pores, decreased clay @ 10 ft, mottled reddish brown and gray, slightly moist, medium dense, fine grained sand, trace fine gravel, iron oxide, decreased fines @ 20 ft, dense 27 30 34 25 14 11 9.2 8.9 10.1 11 16.5 114.7 106.6 125.2 115.3 110.7 Consol SA Hydro Consol Albus-Keefe & Associates, Inc.Plate A-2 Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lith- ology Blows Per Foot Moisture Content (%) Dry Density (pcf) Other Lab Tests Laboratory TestsSamples Material Description E X P L O R A T I O N L O G Rosemead (Willard & Garvey) 3122 Delta Pl, Rosemead, CA 91770 2783.00 4/30/2019 MPHollow-Stem Auger The Olson Company B-1 271.5 WaterCoreBulk140 lbs / 30 in 30 35 40 45 @ 30 ft, light brown, very dense, fine to medium grained sand @ 35 ft, dense, fine to coarse grained sand, clay nodules Silty Sand (SM): Mottled light grayish brown and reddish brown, moist, dense, fine grained sand, mica present Silt (ML): Mottled light grayish brown and reddish brown, moist, very stiff, mica present 23 34 31 28 17 SA Hydro Albus-Keefe & Associates, Inc.Plate A-3 25 Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lith- ology Blows Per Foot Moisture Content (%) Dry Density (pcf) Other Lab Tests Laboratory TestsSamples Material Description E X P L O R A T I O N L O G Rosemead (Willard & Garvey) 3122 Delta Pl, Rosemead, CA 91770 2783.00 4/30/2019 MPHollow-Stem Auger The Olson Company B-1 271.5 WaterCoreBulk140 lbs / 30 in Silty Sand (SM): Mottled light brown and reddish brown, moist, dense, fine grained sand, mica present, 2" layer of silt End of boring at depth of 51.5 ft. Backfilled with soil cutting. No groundwater encountered. 29 Albus-Keefe & Associates, Inc.Plate A-4 50 Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lith- ology Blows Per Foot Moisture Content (%) Dry Density (pcf) Other Lab Tests Laboratory TestsSamples Material Description E X P L O R A T I O N L O G Rosemead (Willard & Garvey) 3122 Delta Pl, Rosemead, CA 91770 2783.00 4/30/2019 SDHollow-Stem Auger The Olson Company B-2 272.5 WaterCoreBulk140 lbs / 30 in 5 10 15 20 ARTIFICIAL FILL (Af) Silty Sand (SM): Medium brown, moist, loose, fine to medium grained sand, some pores, organics, debris, trace gravel, with clay @ 4 ft, reddish brown, very moist, very loose, increased pores ALLUVIUM (Qal) Silty Sand (SM): Brown, medium dense, fine to coarse grained sand, trace gravel, organics, pocket of medium grained sand, some pores @ 10 ft, reddish brown, loose, some clay, decreased pores @ 15 ft, light brown, medium dense, trace fine gravel, iron oxide @ 20 ft, dense, decreased gravel End of boring at depth of 23 ft. No groundwater encountered. Backfilled with soil cutting. 9 19 10 22 5 22 9.6 8.5 9.2 10.3 114.1 114.9 110.3 120.9 SO4 DS pH Resist ChMax, EI Consol Consol Albus-Keefe & Associates, Inc.Plate A-5 Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lith- ology Blows Per Foot Moisture Content (%) Dry Density (pcf) Other Lab Tests Laboratory TestsSamples Material Description E X P L O R A T I O N L O G Rosemead (Willard & Garvey) 3122 Delta Pl, Rosemead, CA 91770 2783.00 4/30/2019 SDHollow-Stem Auger The Olson Company B-3 273.3 WaterCoreBulk140 lbs / 30 in 5 10 15 20 ARTIFICIAL FILL (Af) Silty Sand (SM): Brown, moist, medium dense, fine to coarse grained sand, organics, trace coarse gravel @ 4 ft, loose, increased sand, trace fine to medium gravel, mica present ALLUVIUM (Qal) Silty Sand (SM): Light brown, very moist, medium dense, coarse grained sand Sand with Silt (SP-SM): Light brown gray, moist, medium dense, fine to coarse grained sand, with fine to coarse gravel Silty Sand (SM): Light brown, dense, fine to coarse grained sand, trace gravel @ 16.5 ft, gravel layer @ 20 ft, 2 inch layer of clayey silt, no gravel 22 28 17 20 13 23 4.2 5.2 6.6 4.4 111 89.2 113.4 115.2 Albus-Keefe & Associates, Inc.Plate A-6 Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lith- ology Blows Per Foot Moisture Content (%) Dry Density (pcf) Other Lab Tests Laboratory TestsSamples Material Description E X P L O R A T I O N L O G Rosemead (Willard & Garvey) 3122 Delta Pl, Rosemead, CA 91770 2783.00 4/30/2019 SDHollow-Stem Auger The Olson Company B-3 273.3 WaterCoreBulk140 lbs / 30 in 30 35 40 45 Lean Clay (CL): Brown, moist, very stiff, fine to medium grained sand, trace coarse grained sand, iron oxide, mica present, some silt Silty Sand (SM): Light brown, moist, dense, fine to medium grained sand, trace gravel, mica present, iron oxide Silty Sand with Gravel (SM): Light brown, slightly moist, very dense, fine to coarse grained sand, fine to coarse gravel, mica present Silty Sand (SM): Reddish brown, moist, medium dense, fine to coarse grained sand, mica present Silt (ML): Grayish brown, moist, very stiff, trace fine grained sand, mica present, iron oxide specs, some clay @ 45 ft, hard 13 29 50 9 10 200 ATT 200 200 ATT Albus-Keefe & Associates, Inc.Plate A-7 25 Project: Address: Job Number: Drill Method: Client: Driving Weight: Location: Elevation: Date: Logged By: Depth (feet) Lith- ology Blows Per Foot Moisture Content (%) Dry Density (pcf) Other Lab Tests Laboratory TestsSamples Material Description E X P L O R A T I O N L O G Rosemead (Willard & Garvey) 3122 Delta Pl, Rosemead, CA 91770 2783.00 4/30/2019 SDHollow-Stem Auger The Olson Company B-3 273.3 WaterCoreBulk140 lbs / 30 in Silty Sand (SM): Reddish brown, moist, dense, mica present Clay (CL): Brown, moist, hard, mica present, trace sand, few silt, iron oxide End of boring at depth of 51.5. No groundwater encountered. backfilled with soil cutting. 24 32.7 Albus-Keefe & Associates, Inc.Plate A-8 50 ALBUS-KEEFE & ASSOCIATES, INC. APPENDIX B RELEVANT SOIL LABORATORY TESTING COARSE FINE COARSE MEDIUM FINE Description Silty Sand (SM) Albus-Keefe & Associates, Inc.Plate B-1 2783.00 GRAIN SIZE DISTRIBUTION Job Number Location B-1 GRAVELCOBBLES SILT AND CLAYSAND 10 Depth 6"3"1.5"3/4"3/8"4 10 20 40 60 100 200 0 10 20 30 40 50 60 70 80 90 1000 10 20 30 40 50 60 70 80 90 100 0.00010.0010.010.1110100 U.S. Standard Sieve Sizes Percent RetainedPercent PassingGrain Size in Millimeters COARSE FINE COARSE MEDIUM FINE Description Silty Sand (SM) Albus-Keefe & Associates, Inc.Plate B-2 2783.00 GRAIN SIZE DISTRIBUTION Job Number Location B-1 GRAVELCOBBLES SILT AND CLAYSAND 25 Depth 6"3"1.5"3/4"3/8"4 10 20 40 60 100 200 0 10 20 30 40 50 60 70 80 90 1000 10 20 30 40 50 60 70 80 90 100 0.00010.0010.010.1110100 U.S. Standard Sieve Sizes Percent RetainedPercent PassingGrain Size in Millimeters ALBUS-KEEFE & ASSOCIATES, INC. APPENDIX C PERCOLATION TESTING AND ANALYSES Client:Job. No.: 2783.00 Date Tested:Test by: MP Location: Top of Casing to Bottom of Well (ft): 25 Elev. of Ground Surface (ft): 271.5 Diam. of Test Hole (in): 8 Diam. of Casing (in): 3 Ht. to Top of Casing (ft): 0 Water Tempurature (C°): 21 Elapsed Time Depth to H2O Flow Rate Total H2O used (minutes)(ft)(gal./min.) (gal) 0 11:58 20 0.30 0.00 1 11:59 20 0.20 0.25 2 12:00 20 0.10 0.50 4 12:02 20 0.15 0.80 6 12:04 20 0.15 1.05 8 12:06 20 0.15 1.35 12 12:10 20 0.15 1.95 17 12:15 20 0.15 2.70 22 12:20 20 0.15 3.45 32 12:30 20 0.15 4.95 42 12:40 20 0.15 6.45 72 13:10 20 0.15 10.95 Constant Head Time Field Percolation Testing - Constant Head 5/2/2019 P-1 The Olson Company 0.00 2.00 4.00 6.00 8.00 10.00 12.00 0 1020304050607080Accumulated Flow ‐GallonsTime ‐Minutes ALBUS-KEEFE ASSOCIATES, INC.Plate C-1 Client:Job. No.: 2783.00 Date Tested:Test by: MP Location: Top of Casing to Bottom of Well (ft): 10 Elev. of Ground Surface (ft): 271.5 Diam. of Test Hole (in): 8 Diam. of Casing (in): 3 Ht. to Top of Casing (ft): 0 Water Tempurature (C°): 21 Elapsed Time Depth to H2O Flow Rate Total H2O used (minutes)(ft)(gal./min.) (gal) 0 13:25 5 0.20 0.00 1 13:26 5 0.10 0.15 2 13:27 5 < 0.06 0.30 Time Field Percolation Testing - Constant Head The Olson Company 5/2/2019 P-2 Constant Head 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 011223Accumulated Flow ‐GallonsTime ‐Minutes ALBUS-KEEFE ASSOCIATES, INC.Plate C-2 J.N.: 2783.00 Client: Olson Well No.: P‐1 Condition 1 Condition 2 Condition 3 Units: 1 25 feet 20 feet 5 feet 4.0 Inches Minimum Volume Required: 1473.4 Gal. 0.15 Gal/min. 21 Celsius 0.9647 ft^3/min. Ignore Tᵤ 1 3.07E‐04 ft/min. 0.22 in./hr. ALBUS-KEEFE & ASSOCIATES, INC.Plate C-3 High water Table with Water Above the Well Bottom High Water Table & Water Below Bottom of Well Low Water Table INFILTRATION WELL DESIGN Constant Head USBR 7300‐89 Method The presence or absence of a water table or impervious soil layer within a distance of less than three times that of the water depth in the well (measured from the water surface) will enable the water table to be classified as Condition I, Condition II, Condtion III. Low Water Table‐When the distance from the water surface in the test well to the ground water table, or to an impervious soil layer which is considered for test puposes to be equivalent to a water table, is greater than three times the depth of water in the well, classify as Condition I. High Water Table‐When the distance from the water surface in the test well to the ground water table or to an impervious layer is less than three times the depth of water in the well, a high water table condition exists. Use Condition II when the water table or impervious layer is below the well bottom. Use Condition III when the water table or impervious layer is above the well bottom. (Viscosity of Water @ Temp. T) / (Viscosity of water @ 20° C) (V): Unsaturated Distance Between the Water Surface in the Well and the Water table (Tᵤ): Factor of Safety: Coefficient of Permeability @ 20° C (k₂₀): Design k₂₀: Temperature (T): Depth to Water (h₂): Enter Condition (1, 2 or 3): Ground Surface to Bottom of Well (h₁): Height of Water in the Well (h₁‐h₂=h): Radius of Well (r): Discharge Rate of Water Into Well for Steady‐State Condition (q): J.N.: 2783.00 Client: Olson Well No.: P‐2 Condition 1 Condition 2 Condition 3 Units: 1 10 feet 5 feet 5 feet 4.0 Inches Minimum Volume Required: 1473.4 Gal. < 0.06 Gal/min. 21 Celsius 0.9647 ft^3/min. Ignore Tᵤ 1 1.23E‐04 ft/min. < 0.09 in./hr. ALBUS-KEEFE & ASSOCIATES, INC.Plate C-4 Discharge Rate of Water Into Well for Steady‐State Condition (q): INFILTRATION WELL DESIGN Constant Head USBR 7300‐89 Method Low Water Table High Water Table & Water Below Bottom of Well High water Table with Water Above the Well Bottom Enter Condition (1, 2 or 3): Ground Surface to Bottom of Well (h₁): Depth to Water (h₂): Height of Water in the Well (h₁‐h₂=h): Radius of Well (r): The presence or absence of a water table or impervious soil layer within a distance of less than three times that of the water depth in the well (measured from the water surface) will enable the water table to be classified as Condition I, Condition II, Condtion III. Low Water Table‐When the distance from the water surface in the test well to the ground water table, or to an impervious soil layer which is considered for test puposes to be equivalent to a water table, is greater than three times the depth of water in the well, classify as Condition I. High Water Table‐When the distance from the water surface in the test well to the ground water table or to an impervious layer is less than three times the depth of water in the well, a high water table condition exists. Use Condition II when the water table or impervious layer is below the well bottom. Use Condition III when the water table or impervious layer is above the well bottom. Temperature (T): (Viscosity of Water @ Temp. T) / (Viscosity of water @ 20° C) (V): Unsaturated Distance Between the Water Surface in the Well and the Water table (Tᵤ): Factor of Safety: Coefficient of Permeability @ 20° C (k₂₀): Design k₂₀: PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 APPENDIX 3 MODULAR WETLANDS SYSTEM O&M MANUAL www.modularwetlands.com Maintenance Guidelines for Modular Wetland System - Linear Maintenance Summary o Remove Trash from Screening Device – average maintenance interval is 6 to 12 months.  (5 minute average service time). o Remove Sediment from Separation Chamber – average maintenance interval is 12 to 24 months.  (10 minute average service time). o Replace Cartridge Filter Media – average maintenance interval 12 to 24 months.  (10-15 minute per cartridge average service time). o Replace Drain Down Filter Media – average maintenance interval is 12 to 24 months.  (5 minute average service time). o Trim Vegetation – average maintenance interval is 6 to 12 months.  (Service time varies). System Diagram Access to screening device, separation chamber and cartridge filter Access to drain down filter Pre-Treatment Chamber Biofiltration Chamber Discharge Chamber Outflow Pipe Inflow Pipe (optional) www.modularwetlands.com Maintenance Procedures Screening Device 1. Remove grate or manhole cover to gain access to the screening device in the Pre- Treatment Chamber. Vault type units do not have screening device. Maintenance can be performed without entry. 2. Remove all pollutants collected by the screening device. Removal can be done manually or with the use of a vacuum truck. The hose of the vacuum truck will not damage the screening device. 3. Screening device can easily be removed from the Pre-Treatment Chamber to gain access to separation chamber and media filters below. Replace grate or manhole cover when completed. Separation Chamber 1. Perform maintenance procedures of screening device listed above before maintaining the separation chamber. 2. With a pressure washer spray down pollutants accumulated on walls and cartridge filters. 3. Vacuum out Separation Chamber and remove all accumulated pollutants. Replace screening device, grate or manhole cover when completed. Cartridge Filters 1. Perform maintenance procedures on screening device and separation chamber before maintaining cartridge filters. 2. Enter separation chamber. 3. Unscrew the two bolts holding the lid on each cartridge filter and remove lid. 4. Remove each of 4 to 8 media cages holding the media in place. 5. Spray down the cartridge filter to remove any accumulated pollutants. 6. Vacuum out old media and accumulated pollutants. 7. Reinstall media cages and fill with new media from manufacturer or outside supplier. Manufacturer will provide specification of media and sources to purchase. 8. Replace the lid and tighten down bolts. Replace screening device, grate or manhole cover when completed. Drain Down Filter 1. Remove hatch or manhole cover over discharge chamber and enter chamber. 2. Unlock and lift drain down filter housing and remove old media block. Replace with new media block. Lower drain down filter housing and lock into place. 3. Exit chamber and replace hatch or manhole cover. www.modularwetlands.com Maintenance Notes 1. Following maintenance and/or inspection, it is recommended the maintenance operator prepare a maintenance/inspection record. The record should include any maintenance activities performed, amount and description of debris collected, and condition of the system and its various filter mechanisms. 2. The owner should keep maintenance/inspection record(s) for a minimum of five years from the date of maintenance. These records should be made available to the governing municipality for inspection upon request at any time. 3. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements. 4. Entry into chambers may require confined space training based on state and local regulations. 5. No fertilizer shall be used in the Biofiltration Chamber. 6. Irrigation should be provided as recommended by manufacturer and/or landscape architect. Amount of irrigation required is dependent on plant species. Some plants may require irrigation. www.modularwetlands.com Maintenance Procedure Illustration Screening Device The screening device is located directly under the manhole or grate over the Pre-Treatment Chamber. It’s mounted directly underneath for easy access and cleaning. Device can be cleaned by hand or with a vacuum truck. Separation Chamber The separation chamber is located directly beneath the screening device. It can be quickly cleaned using a vacuum truck or by hand. A pressure washer is useful to assist in the cleaning process. www.modularwetlands.com Cartridge Filters The cartridge filters are located in the Pre-Treatment chamber connected to the wall adjacent to the biofiltration chamber. The cartridges have removable tops to access the individual media filters. Once the cartridge is open media can be easily removed and replaced by hand or a vacuum truck. Drain Down Filter The drain down filter is located in the Discharge Chamber. The drain filter unlocks from the wall mount and hinges up. Remove filter block and replace with new block. www.modularwetlands.com Trim Vegetation Vegetation should be maintained in the same manner as surrounding vegetation and trimmed as needed. No fertilizer shall be used on the plants. Irrigation per the recommendation of the manufacturer and or landscape architect. Different types of vegetation requires different amounts of irrigation. www.modularwetlands.com Inspection Form Modular Wetland System, Inc. P. 760.433-7640 F. 760-433-3176 E. Info@modularwetlands.com For Office Use Only (city) (Zip Code)(Reviewed By) Owner / Management Company (Date) Contact Phone ( )_ Inspector Name Date / / Time AM / PM Weather Condition Additional Notes Yes Depth: Yes No Modular Wetland System Type (Curb, Grate or UG Vault):Size (22', 14' or etc.): Other Inspection Items: Storm Event in Last 72-hours? No Yes Type of Inspection Routine Follow Up Complaint Storm Office personnel to complete section to the left. 2972 San Luis Rey Road, Oceanside, CA 92058 P (760) 433-7640 F (760) 433-3176 Inspection Report Modular Wetlands System Is the filter insert (if applicable) at capacity and/or is there an accumulation of debris/trash on the shelf system? Does the cartridge filter media need replacement in pre-treatment chamber and/or discharge chamber? Any signs of improper functioning in the discharge chamber? Note issues in comments section. Chamber: Is the inlet/outlet pipe or drain down pipe damaged or otherwise not functioning properly? Structural Integrity: Working Condition: Is there evidence of illicit discharge or excessive oil, grease, or other automobile fluids entering and clogging the unit? Is there standing water in inappropriate areas after a dry period? Damage to pre-treatment access cover (manhole cover/grate) or cannot be opened using normal lifting pressure? Damage to discharge chamber access cover (manhole cover/grate) or cannot be opened using normal lifting pressure? Does the MWS unit show signs of structural deterioration (cracks in the wall, damage to frame)? Project Name Project Address Inspection Checklist CommentsNo Does the depth of sediment/trash/debris suggest a blockage of the inflow pipe, bypass or cartridge filter? If yes, specify which one in the comments section. Note depth of accumulation in in pre-treatment chamber. Is there a septic or foul odor coming from inside the system? Is there an accumulation of sediment/trash/debris in the wetland media (if applicable)? Is it evident that the plants are alive and healthy (if applicable)? Please note Plant Information below. Sediment / Silt / Clay Trash / Bags / Bottles Green Waste / Leaves / Foliage Waste:Plant Information No Cleaning Needed Recommended Maintenance Additional Notes: Damage to Plants Plant Replacement Plant Trimming Schedule Maintenance as Planned Needs Immediate Maintenance www.modularwetlands.com Maintenance Report Modular Wetland System, Inc. P. 760.433-7640 F. 760-433-3176 E. Info@modularwetlands.com For Office Use Only (city) (Zip Code)(Reviewed By) Owner / Management Company (Date) Contact Phone ( )_ Inspector Name Date / / Time AM / PM Weather Condition Additional Notes Site Map # Comments: 2972 San Luis Rey Road, Oceanside, CA 92058 P. 760.433.7640 F. 760.433.3176 Inlet and Outlet Pipe Condition Drain Down Pipe Condition Discharge Chamber Condition Drain Down Media Condition Plant Condition Media Filter Condition Long: MWS Sedimentation Basin Total Debris Accumulation Condition of Media 25/50/75/100 (will be changed @ 75%) Operational Per Manufactures' Specifications (If not, why?) Lat:MWS Catch Basins GPS Coordinates of Insert Manufacturer / Description / Sizing Trash Accumulation Foliage Accumulation Sediment Accumulation Type of Inspection Routine Follow Up Complaint Storm Storm Event in Last 72-hours? No Yes Office personnel to complete section to the left. Project Address Project Name Cleaning and Maintenance Report Modular Wetlands System PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 APPENDIX 4 SOURCE CONTROL BMP FACT SHEETS County of Los Angeles D-1 February 2014 S-1: Storm Drain Message and Signage Purpose Waste material dumped into storm drain inlets can adversely impact surface and ground waters. In fact, any material discharged into the storm drain system has the potential to significantly impact downstream receiving waters. Storm drain messages have become a popular method of alerting and reminding the public about the effects of and the prohibitions against waste disposal into the storm drain system. The signs are typically stenciled or affixed near the storm drain inlet or catch basin. The message simply informs the public that dumping of wastes into storm drain inlets is prohibited and/or that the drain ultimately discharges into receiving waters. General Guidance The signs must be placed so they are easily visible to the public. Be aware that signs placed on sidewalk will be worn by foot traffic. Design Specifications Signs with language and/or graphical icons that prohibit illegal dumping, must be posted at designated public access points along channels and streams within the project area. Consult with Los Angeles County Department of Public Works (LACDPW) staff to determine specific signage requirements for channels and streams. Storm drain message markers, placards, concrete stamps, or stenciled language/icons (e.g., “No Dumping – Drains to the Ocean”) are required at all storm drain inlets and catch basins within the project area to discourage illegal or inadvertent dumping. Signs should be placed in clear sight facing anyone approaching the storm drain inlet or catch basin from either side (see Figure D-1 and Figure D-2). LACDPW staff should be contacted to determine specific requirements for types of signs and methods of application. A stencil can be purchased for a nominal fee from LACDPW Building and Safety Office by calling (626) 458-3171. All storm drain inlet and catch basin locations must be identified on the project site map. Maintenance Requirements Legibility and visibility of markers and signs should be maintained (e.g., signs should be repainted or replaced as necessary). If required by LACDPW, the owner/operator or homeowner’s association shall enter into a maintenance agreement with the agency or record a deed restriction upon the property title to maintain the legibility of placards and signs. S-1: Storm Drain Message and Signage County of Los Angeles D-2 February 2014 Figure D-1. Storm Drain Message Location – Curb Type Inlet Figure D-2. Storm Drain Message Location – Catch Basin/Area Type Inlet CONCRETE PERIMETER County of Los Angeles D-19 February 2014 S-8: Landscape Irrigation Practices Purpose Irrigation runoff provides a pathway for pollutants (i.e., nutrients, bacteria, organics, sediment) to enter the storm drain system. By effectively irrigating, less runoff is produced resulting in less potential for pollutants to enter the storm drain system. General Guidance Do not allow irrigation runoff from the landscaped area to drain directly to storm drain system. Minimize use of fertilizer, pesticides, and herbicides on landscaped areas. Plan sites with sufficient landscaped area and dispersal capacity (e.g., ability to receive irrigation water without generating runoff). Consult a landscape professional regarding appropriate plants, fertilizer, mulching applications, and irrigation requirements (if any) to ensure healthy vegetation growth. Design Specifications Choose plants that minimize the need for fertilizer and pesticides. Group plants with similar water requirements and water accordingly. Use mulch to minimize evaporation and erosion. Include a vegetative boundary around project site to act as a filter. Design the irrigation system to only water areas that need it. Install an approved subsurface drip, pop-up, or other irrigation system.1 The irrigation system should employ effective energy dissipation and uniform flow spreading methods to prevent erosion and facilitate efficient dispersion. Install rain sensors to shut off the irrigation system during and after storm events. Include pressure sensors to shut off flow-through system in case of sudden pressure drop. A sudden pressure drop may indicate a broken irrigation head or water line. If the hydraulic conductivity in the soil is not sufficient for the necessary water application rate, implement soil amendments to avoid potential geotechnical hazards (i.e., liquefaction, landslide, collapsible soils, and expansive soils). 1 If alternative distribution systems (e.g., spray irrigation) are approved, the County will establish guidelines to implement these new systems. S-8: Landscape Irrigation Practices County of Los Angeles D-20 February 2014 For sites located on or within 50 feet of a steep slope (15% or greater), do not irrigate landscape within three days of a storm event to avoid potential geotechnical instability.2 Implement Integrated Pest Management practices. For additional guidelines and requirements, refer to the Los Angeles County Department of Health Services. Maintenance Requirements Maintain irrigation areas to remove trash and debris and loose vegetation. Rehabilitate areas of bare soil. If a rain or pressure sensor is installed, it should be checked periodically to ensure proper function. Inspect and maintain irrigation equipment and components to ensure proper functionality. Clean equipment as necessary to prevent algae growth and vector breeding. Maintenance agreements between LACDPW and the owner/operator may be required. Failure to properly maintain building and property may subject the property owner to citation. 2 As determined by the City of Los Angeles, Building and Safety Division PRELIMINARY LOW IMPACT DEVELOPMENT REPORT SEPTEMBER 30, 2019 ROSEMEAD TENTATIVE TRACT NO. 82875 APPENDIX 5 PUBLIC EDUCATION MATERIALS Storm drains are for rain… they’re not pooper scoopers. L.A. County residents walk a dog without picking up the droppings more than 62,000 times per month. Disease-causing dog waste washes from the ground and streets into storm drains and flows straight to the ocean — untreated. Remember to bring a bag and clean up after your dog. PP ickick UpUp AfterAfter YourYour Pooch!Pooch! Dog owners can help so l v e t h e s t o r m w a t e r p o l l u t i o n problem by taking thes e e a s y s t e p s … • Clean up after your d o g e v e r y s i n gle time. • Take advantage of the complimentary waste bags offered in dispensers at local parks. • Ensure you always have extra bags in your car so you are prepared when you travel with your do g. • Carry extra bags when walking your dog and make them available to other p e t o w n e r s w h o a r e w i t h o u t . • Teach children how t o p r o p e r l y c l e a n u p a f ter a pet. Encourage them to throw t h e u s e d b a g s i n t h e nearest trash receptacl e i f t h e y a re away from home. • Put a friendly message on the bulletin board at the local dog park to r e m i n d p et owners to clean up after their dogs. • Te ll friends and neighbors abo u t t h e i ll effects of animal waste on the environment. E n c o u r a g e them to clean up after t h e i r p e t s a s w e l l . Tips for Dog Owners: AA YardYard is ais a Terrible Terrible ThingThing toto Waste!Waste! Storm drains are for rain…not yard waste. Residential yard waste represents about 13 percent of the total waste generated in L.A. County. Pesticides, fertilizer and yard waste such as leaves and mowed grass wash from the ground and streets into storm drains and flow straight to the ocean — untreated. Remember to use pesticides and fertilizer wisely and pick-up yard waste. Tips For Yard Care: L.A. County residents c a n h e l p solve the stormwater pollution problem by tak i n g t h e s e e a s y s t e p s … • Do not over-fertilize and do not use fertilizer or p e s ticides near ditches, gutters or storm drains. • Do not use fertilizer or pesticides before a rain. • Follow the directions on the label carefully. • Use pesticides sparingly — more is not better. “Spot” apply, rather tha n “ b l a n k e t ” a p ply. • When watering your lawn, use the least amount of water possible so it do e s n ’ t r u n i n t o t h e s t r e e t c a r r y i n g pesticides and other chemicals with it. • Use non-toxic products for your garden and l awn whenever possible. • If you must store pesticides or fertilizer, make sur e they are in a sealed, w a t e r - p r o o f c o n t a i n e r i n a covered area to prevent ru n o ff. • Do not blow, sweep, hose o r r a k e l e a v e s o r o t h e r yard trimmings into the street, gutter o r s t o r m d r a i n . A message from the Cou n t y o f L o s A n g e l e s D e p a r t m e n t o f Public Works. Printed on recycled paper. DoDon’t Paint the’t Paint the Town Red!Town Red! Storm drains are for rain… they’re not for paint disposal. More than 197,000 times each month, L.A. County residents wash their dirty paint brushes under an outdoor faucet. This dirty rinse water flows into the street, down the storm drain and straight to the ocean — untreated. Remember to clean water-based paint brushes in the sink, rinse oil-based paint brushes with paint thinner, and take old paint and paint-related products to a Household Hazardous Waste/E-Waste collection event. Tips for Paint Clean-Up: L.A. County residents c a n h e l p s o l v e t h e s t o r m w a t e r pollution problem by t a k i n g t h e s e e a s y s t e p s w h e n working with paint an d p a i n t - r e l a t e d p r o d u c t s … • Never dispose of paint or paint-relat e d p r o d u c t s i n t h e gutters or storm drains. This is called illegal dumping. Take them to a House h o l d H a z a r d o u s W a s t e / E - W a s t e collection event. Ca l l 1 ( 8 8 8 ) C L E A N L A o r visit www.888CleanLA.com t o l o c a t e a n e v e n t n e a r y o u . • Buy only what you need. Reuse leftover paint for touch-ups or donate i t t o a l o c a l g r a f f i t i a b a t e m e n t program. Recycle or u s e e x c e s s p a i n t . • Clean water-based pa i n t b r u s h es in the sink. • Oil-based paints shou l d b e c l e a n e d w i t h p a i n t t h inner. Filter and reuse paint t h i n n e r . S e t t h e u s e d t h i n n e r aside in a closed jar t o s e t t l e - o u t p a i n t p a r t i c l e s . • Store paints and pain t - r e l a t e d p r o d u c t s i n r i g i d , durable and watertight co n t a i n e r s w i t h tight-fitting covers. A message from the Cou n t y o f L o s A n g e l e s D e p a r t m e n t o f Public Works. Printed on recycled paper. Are You a Litter B u g A r e Y o u a L i t t e r B u g and a n d DoDo n’t Know It?t K n o w I t ? Take our quiz! Have you ever... • Dropped a cigarette butt or trash on the grou n d ? • Failed to pick up after your dog while out on a w a l k ? • Overwatered your lawn after ap p l y i ng fertilizers/pesticides? • Disposed of used motor oil in the s t r e e t , gutter or garbage? If you answered yes to any of these action s , t h e n YOU ARE A LITTER BUG! Each of these behaviors contribute to stor m w a t e r pollution, which contaminates o u r o c e a n a n d waterways, kills marine life and causes beach c l o s u r e s . You can become part of the solution! To find out how, flip this card over. For more information, c a l l o r v i s i t : Follow these simple steps to prevent stormwater pollution • Put your garbage wh e r e i t b e l o n g s — i n t h e t r ash can. • Pick up after your dog w h e n out on a walk. • Reduce pesticide and f e r t i l i z e r u s e ; d o n ’ t o v e r w a t e r after application or apply if rain is f o r e c a s t . • Dispose of used motor oil at an oil r e c y c l i n g c e n t e r or at a free Househo l d H a z a r d o u s W aste/E-Waste collection event. A message from the Cou n t y o f Los Angeles Department of Public Works. Printed on recycled paper. Follow these simple step s t o F ol lo w t h es e s i m p l e s t e p s t o prevent stormwater po l l u t i o n : pre v e n t s to rmw a te r p ol lu t i on: