The URL can be used to link to this page

PC - Item 3B - Exhibit F - Appendix I Preliminary LIDPreliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 1 Mission Villas, LLC February 2022 Page I PRELIMINARY LOW IMPACT DEVELOPMENT PLAN (LID) Prepared for: Mission Villas, LLC Attention: Mitch Gardner 11766 Wilshire Boulevard, Suite 820 Los Angeles, CA 90025 Property: 8601 Mission Drive Rosemead, California APN: 5389-009-029, 5389-009-030, 5389-009-031 Prepared by: C&V Consulting, Inc. 9830 Irvine Center Drive Irvine, California 92618 (949) 916-3800 Contact: Mr. Ryan Bittner, P.E. Preparation Date: February 2022 Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 1 Mission Villas, LLC February 2022 Page II Receipt of WDID REPLACE THIS SHEET To be provided prior to final approval Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 1 Mission Villas, LLC February 2022 Page III Notice of Intent REPLACE THIS SHEET To be provided prior to final approval Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 1 Mission Villas, LLC February 2022 Page IV Table of Contents SECTION PAGE SECTION 1 COVER ............................................................................................................................................................................ I RECEIPT OF WDID ........................................................................................................................................................ II NOTICE OF INTENT ....................................................................................................................................................... III PROJECT OWNER’S CERTIFICATION ............................................................................................................................... V ENGINEER CERTIFICATION .......................................................................................................................................... VI SECTION 2 ................................................................................................................................................... 1 A.Contact Information/List of Responsible Parties .............................................................................................. 1 SECTION 3 ................................................................................................................................................... 2 A.References ................................................................................................................................................... 2 SECTION 4 – BODY OF LID PLAN ............................................................................................................. 3 A.Objectives.................................................................................................................................................... 3 B.Project Background and Description .............................................................................................................. 3 C.Vicinity Map ............................................................................................................................................... 3 D.Pre-Development Drainage Condition ............................................................................................................ 3 E.Post-Development Drainage Condition .......................................................................................................... 5 F.LID Project Types, Characteristics, & Activities ............................................................................................. 5 G.Pollutant Source Identification and BMP Selection ......................................................................................... 6 H.Source Control BMPs ................................................................................................................................... 6 I.Non-Structural BMPs ................................................................................................................................... 10 J.BMP Maintenance, Inspection, and Repair .................................................................................................... 11 K.Inspection, Maintenance, and Responsibility for BMPs ................................................................................. 12 L.Operation/Maintenance Funding after Project Completion ............................................................................. 14 List of Figures Figure 1: Project Vicinity Map Figure 2: DMP Exhibit Figure 3: Impaired Waters List of Appendices Appendix A: Volume and Flow Rate Calculations and Hydraulic Report Appendix B: Site BMPs Appendix C: Drywell System Information and Sizing Appendix D: “NO DUMPING – DRAINS TO OCEAN” Stencil Examples Appendix E: Catch Basin Cleaning Appendix F: General Education Materials Appendix G: Operations and Maintenance plan Appendix H: Geotechnical Report Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 1 Mission Villas, LLC February 2022 Page V Project Owner’s Certification of the Preliminary Low Impact Development (LID) Plan Project Name: Mission Villas Rosemead Project Number: Vesting Tentative Tract Map No. 83705 APN: 5389-009-029, 5389-009-030, 5389-009-031 Project Address: 8601 Mission Drive Rosemead, CA 91770 This Preliminary Low Impact Development (LID) Plan for the Mission Villas Rosemead (VTTM No. 83705) project has been prepared for Mission Villas, LLC by C&V Consulting, Inc. It is intended to comply with the requirements of the City of Rosemead’s Conditions of Approval. The undersigned is authorized to approve implementation of provisions of this plan as appropriate and will strive to have the plan carried out by successors consistent with the County of Los Angeles LID Manual and the intent of the NPDES storm water 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 gathered 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.” Owner’s Name: Erik Pfahler Owner’s Title: Senior Vice President Company: Mission Villas, LLC Address: 11766 Wilshire Blvd., Suite 820, Los Angeles, CA 90025 Email: erik@borsteinenterprises.com Telephone No.: (310) 582-1991 x203 Signature: Date: Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 1 Mission Villas, LLC February 2022 Page VI Engineer Certification Engineer’s Name: Ryan J. Bittner Engineer’s Title: Principal Company: C&V Consulting, Inc. Address: 9830 Irvine Center Drive, Irvine, CA 92618 Email: rbittner@cvc-inc.net Telephone No. (949) 916-3800 I hereby certify that this Low Impact Development Plan is in compliance with, and meets the requirements set forth in, Order No. R4-2012-0175, of the Los Angeles Regional Water Quality Control Board. Engineer’s Signature Date Place Stamp Here Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 2 Mission Villas, LLC February 2022 Page 1 Section 2 A. Contact Information/List of Responsible Parties The homeowner’s association (HOA) contact information is: Contact: TBD Phone: TBD The Homeowner’s Association The HOA shall have primary responsibility and significant authority for the implementation, maintenance, and inspection of the property Best Management Practices (BMPs). Duties include, but are not limited to:  Implementing all elements of the Low Impact Development Plan, including but not limited to: o Implementation of prompt and effective erosion and sediment control measures o Implementing all non-storm water management, and materials and waste management activities, such as: monitoring, discharges, general site clean-up; vehicle and equipment cleaning, spill control; ensuring that nothing other than storm water enters the storm drain system, etc.  Pre-storm inspections  Storm event inspections  Post-storm inspections  Routine inspections as described in the Low Impact Development Plan  Ensuring elimination of all unauthorized discharges  The HOA shall be assigned authority to mobilize crews to make immediate repairs to the control measures.  Coordinate all the necessary corrections/repairs are made immediately, and that the project always complies with the Low Impact Development Plan.  Managing and report any Illicit Connections or Illegal Discharges. Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 3 Mission Villas, LLC February 2022 Page 2 Section 3 A. References The following documents are made a part of this Low Impact Development Plan by reference:  Project plans and specifications for Vesting Tentative Tract No. 83705, prepared by C&V Consulting, Inc.  State Water Resources Control Board (SWRCB) Order No. 2013-0001-DWQ, February 5, 2013.  National Pollutant Discharge Elimination System (NPDES) General Permit No. CAS000002, Waste Discharge Requirements (WDRs) for Discharges of Storm Water Runoff Associated with Construction Activity.  California Stormwater BMP Handbook – Construction, November 2009.  California Stormwater BMP Handbook – New Development and Redevelopment, January 2003.  County of Los Angeles Department of Public Works L.I.D. Standards Manual, February 2014 Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 3 Section 4 – Body of LID Plan A. Objectives This Low Impact Development (LID) Plan has four main objectives: 1) Identify all pollutant sources, including sources of sediment that may affect the quality of storm water discharges associated with daily use / activity (storm water discharges) from the property site. 2) Identify non-storm water discharges. 3) Identify, construct, implement and maintain Best Management Practices (BMPs) to reduce or eliminate pollutants in storm water discharges and authorized non-storm water discharges from the property site. 4) Develop a maintenance schedule for BMPs designed to reduce or eliminate pollutants. B. Project Background and Description The proposed project is in Rosemead, California is approximately 3.38 net acres. The proposed development intends to construct 4 buildings of 8 attached 2-story duplex units as well as 29 2- story single family homes. These homes have private garages, private drive aisles, private yards, sidewalks, and common landscaped areas. The residential project site will be accessible with one (1) entrance/ exit along Mission Road. In the existing condition there is no cross-lot drainage as the existing residential lots have various perimeter controls surrounding them. In the proposed condition a new CMU wall will be built and therefore off-site run-on is not of concern. The pre-development conditions of the project site consist of a vacant lot covered by vegetation. Impervious cover of the pre-developed condition was determined to be 1.5% and pervious cover to be 98.5% by utilizing Topographic information. For this preliminary study, post-development impervious cover was estimated to be 86% per LACDPW Hydrology Manual land use type “Low-Rise Apartments, Condominiums, and Townhouses”. Imperviousness is to be verified with final site plan to confirm the consistency of the water quality treatment design during final engineering. C. Vicinity Map The proposed development encompasses three (3) parcels consisting of approximately 3.44 gross acres and 3.38 net acres. The site is bounded by existing residential lots to the north and east, Mission Drive to the south, and power lines owned by Southern California Edison to the west. Refer to Figure 1 for the Vicinity Map D. Pre-Development Drainage Condition All three parcels are currently a vacant lot. Besides two small service roads in southern and eastern portions of the site the site is all pervious coverage. The site is surrounded by alternating masonry block wall, wooden fence, and chain link fence around the entire property. There is existing public sidewalk and driveway entrances along Mission Drive. There are no existing Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 4 storm drain facilities located on the site and no storm drain facilities located in the adjacent portion of Mission Drive along the project frontage. The existing drainage pattern of the site is accounted for as one drainage area. The entire site sheet flows over the vacant land in a southerly direction. Stormwater appears to simply sheet flow over existing driveway entrances and enters Mission Road. Once stormwater enters Mission Rd. it flows in a southeasterly direction and enters a Los Angeles County Flood Control District (LACFCD) owned catch basin approximately 500’ downstream of our site. This catch basin is connected to a LACFCD 30” RCP which flows into the Eaton Wash channel then into the Rio Hondo Channel. The Rio Hondo Channel then connects to the Los Angeles River then ultimately the Pacific Ocean. Water bodies downstream of the project site are listed on the most current 303 (d) List as follows:  Rio Hondo Channel Reach 3 o Indicator Bacteria o Iron o Oxygen, Dissolved  Rio Hondo Channel Reach 2 o Cyanide  Rio Hondo Channel Reach 1 o Copper o Indicator Bacteria o Lead o Toxicity o Trash o Zinc o pH  Los Angeles River Reach 2 o Ammonia o Copper o Indicator Bacteria o Lead o Nutrients (Algae) o Oil o Trash  Los Angeles River Reach 1 o Ammonia o Cadmium o Cyanide o Indicator Bacteria o Lead o Nutrients (Algae) o Trash o pH  Los Angeles River Estuary o Chlordane Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 5 o Toxicity o Trash  San Pedro Bay Near/ Offshore Zones o Chlordane o DDT (tissue & sediment) o PCBs (Polychlorinated biphenyls) o Sediment Toxicity E. Post-Development Drainage Condition The proposed project consists of 8 duplex units and 29 single family homes over approximately 3.38 acres. The proposed development includes drive aisles, parking, landscaping, walkways, patios, and common open space areas. The site will be graded to collect runoff at one low point to control the amount of imported fill during grading and maintaining the existing site drainage pattern. The proposed development will utilize onsite catch basins, infiltration systems, and a detention pipe system to capture and treat stormwater. Stormwater up to the design capture volume will be infiltrated by a proposed onsite drywell system. Stormwater runoff will be conveyed via proposed onsite gutter and directed to one sump area equipped with a curb inlet catch basin. There will be two additional catch basins located along the site’s main spine in flow by conditions to convey stormwater into the underground storm drain system. The sump catch basin will be located at the end of the drive aisle at the southern property line. All on-site catch basins will be connected by storm drain pipe to the drywell infiltration system for water quality treatment. During larger storm events, stormwater runoff will back up the drywell system which is connected to the underground detention system. Larger storm events will bypass the infiltration system and overflow into a proposed grate inlet catch basin which is attached to a parkway culvert. Once stormwater enters the parkway culvert it will drain into Mission Road and follow the existing drainage pattern. For emergency overflow, runoff will spill out of the proposed curb inlet catch basin, topple over the proposed driveway entrance, and sheet flow into Mission Road. Refer to separately prepared Preliminary Grading and Utility Plans for site design information. Per Preliminary Geotechnical Investigation, prepared by Albus & Associates, Inc. dated October 27, 2021, infiltration BMPs were determined to be feasible. “Based on the results of percolation testing and analyses, the well configuration as depicted on Plate 2 may utilize a “measured” peak flow rate of 0.16 ft³/sec. This flow rate corresponds to an average peak infiltration rate of 17.0 in./hr.” Refer to Figure 2, BMP Exhibit for additional information. F. LID Project Types, Characteristics, & Activities Per the Los Angeles Department of Public Works (LACDPW), Low Impact Development Standards Manual, dated February 2014, the proposed project is classified as a “Designated Project.” A “Designated Project” is defined by the LACDPW as follows: Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 6 “Redevelopment projects, which are developments that result in creation or addition or replacement of either: (1) 5,000 square feet or more of impervious surface on a site that was previously developed as described in the above bullets; or (2) 10,000 square feet or more of impervious surface area on a site that was previous developed as a single-family home.” G. Pollutant Source Identification and BMP Selection The following is a list of materials to be used in the daily construction activities at the project site, which will potentially contribute to pollutants, other than sediment, to storm water runoff. Control Practices for each activity are identified below:  Vehicle fluids, including oil, grease, petroleum, and coolants from personal vehicles.  Landscaping materials and wastes (topsoil, plant materials, herbicides, fertilizers, mulch, pesticides)  General trash debris and litter  Pet waste (bacteria/ fecal coliforms) The Best Management Practices (BMPs) that have been selected for implementation on this project are detailed in the following sections. H. Source Control BMPs The County of Los Angeles LID Standards Manual lists preference for selection of BMPs which includes retention-based stormwater quality control measures, biofiltration, vegetation-based storm quality control measures, and/or treatment-based stormwater quality control measures. This project has selected a retention-based stormwater quality control measure by using a drywell infiltration system. In the soils report prepared by Albus & Associates, Inc. infiltration systems were determined to be feasible as a stormwater BMP. Additionally, roof gutters will discharge to landscape areas using splash blocks when possible, creating a passive bio treatment in small planter areas prior to interception by an area drain system, catch basin, and storm drain system. All runoff from the site is tributary to the proposed onsite drywell infiltration system. As retention-based stormwater quality control measures are of the highest priority per the LA County LID Manual, the other the other stormwater quality control measures were not considered. Drywells were selected for their reduced footprint compared to other retention-based infiltration systems. Structural BMPs shall be installed by Mission Villas, LLC, the developer, through the construction and development of the project; planting and irrigation systems shall be designed by licensed landscape architects and installed by qualified contractors to specifications and standards of the City of Rosemead. The structural BMPs used for this project are summarized below. Project proponents shall implement site design concepts that achieve each of the following:  Minimize Storm Water Pollutants of Concern Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 7  Peak Storm Water Runoff Discharge Rate The following tables identify the source control and treatment BMPs and how each is implemented to achieve each site design concept. Table-1: Site Design BMPs BMP TECHNIQUE INCLUDED? BRIEF DESCRIPTION OF METHOD YES NO SD-10 Site Design & Landscape Planning X SD-11 Roof Runoff Controls X SD-12 Efficient Irrigation X SD-13 Storm Drain Signage X SD-20 Pervious Pavements X Site design does not allow for this BMP. SD-21 Alternative Building Materials X Not Applicable SD-30 Fueling Areas X Not Applicable SD-31 Maintenance Bays & Docks X Not Applicable SD-32 Trash Storage Areas X No Trash Storage Areas Proposed SD-33 Vehicle Washing Areas X Not Applicable SD-34 Outdoor Material Storage Areas X Not Applicable SD-35 Outdoor Work Areas X Not Applicable SD-36 Outdoor Processing Areas X Not Applicable Roof Runoff Controls All roof runoff will be collected and directed to splash blocks then onto grass or vegetated swales before discharging to the street or storm drain system. Area drains within the onsite landscaping between buildings will flow to onsite infiltration system where flows will be treated. Efficient Irrigation As part of the design of all common area landscape irrigation shall employ water conservation principals, including, but not limited to, such provisions as water sensors, programmable irrigation times (for short cycles), etc., will be used. Such common areas will be maintained by the HOA. Storm Drain Signage Storm Drain Signage will be provided on all proposed on-site catch basins to prevent residence from discarding pollutants to the storm drain system and potentially obstructing the proposed Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 8 BMP treatment facility. The placard or stencil will indicate the ultimate destination of the runoff entering the device. This stencil shall be always weatherproof and visible. The HOA will be responsible for maintaining the signage after the construction is completed. See Appendix D for an example. Table-2: Source Control BMPs BMP TECHNIQUE INCLUDED? BRIEF DESCRIPTION OF METHOD YES NO S-1 Storm Drain Message and Signage X S-2 Outdoor Material Storage Area X Not Applicable S-3 Outdoor Trash Storage and Waste Handling Area X Not Applicable S-4 Outdoor Loading/Unloading Dock Area X No Loading Dock Areas S-5 Outdoor Repair/Maintenance Area X No Maintenance Bays S-6 Outdoor Vehicle/Equipment’s/Accessory Washing Area X No Wash Areas S-7 Fueling Area X No Fueling Areas S-8 Landscape Irrigation Practices X S-9 Building Materials Selection X S-10 Animal Care and Handling Facilities X No Animal Care Facility S-11 Outdoor Horticulture Areas X Not Applicable Storm Drain Message and Signage Storm Drain Signage will be provided on all proposed on-site catch basins to prevent residence from discarding pollutants to the storm drain system and potentially obstructing the proposed BMP treatment facility. The placard or stencil will indicate the ultimate destination of the runoff entering the device. This stencil shall be always weatherproof and visible. The HOA will be responsible for maintaining the signage after the construction is completed. See Appendix B for an example. Landscape Irrigation Processes Management programs will be designed and established by the HOA, who will maintain the common areas within the project site. These programs will include how to mitigate the potential dangers of fertilizer and pesticide usage (refer to the Maintenance and Frequency Table). Ongoing maintenance will be consistent with the State of California Model- Water Efficient Landscape Ordinance. Fertilizer and pesticide usage shall be consistent with County Management Guidelines for use of Fertilizers and Pesticides. Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 9 Building Materials Selection Material selection will minimize the use of copper, galvanized metals and other materials that could add significant amounts of harmful pollutants to stormwater runoff. Table-3: Stormwater Quality Control BMPs BMP NAME INCLUDED? IF NOT APPLICABLE, STATE BRIEF REASON YES NO RET-1 Bioretention X Used alternative method – Drywell System RET-2 Infiltration Basin X Used alternative method – Drywell System RET-3 Infiltration Trench X Used alternative method – Drywell System RET-4 Drywell X A Maxwell Plus Drywell System will be used on this site. RET-5 Permeable Pavement without an Underdrain X Used alternative method – Drywell System RET-6 Rain Barrel/Cistern X Used alternative method – Drywell System BIO-1 Biofiltration X Used alternative method – Drywell System VEG-1 Green Roof X Space not available for BMP VEG-2 Stormwater Planter X Used alternative method – Drywell System VEG-3 Tree-Well Filter X Used alternative method – Drywell System VEG-4 Vegetated Swales X Space not available for BMP VEG-5 Vegetated Filter Strip X Space not available for BMP T-1 Sand Filter X Space not available for BMP T-2 Constructed Wetland X This is not a wetland area/ development T-3 Extended Detention Basin X Space not available for BMP T-4 Wet Pond X This is not a wetland area/ development T-5 Permeable Pavement with an Underdrain X Used alternative method – Drywell System RET-4 Drywell Storm water will enter the drywell unit via curb openings throughout the site and flow via pipe directly onto specially designed pretreatment chamber. The pretreatment chamber is designed intercept the majority of the first flows during a rain event and reduce the impact of sediment and debris on the system. After the pretreatment chamber fills up stormwater will flow into the main drywell system where it will be infiltrated. A detention system located upstream of the drywell will have a high-flow bypass inlet for flows greater than the 85th percentile storm event. See Appendix C for drywell sizing calculations. Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 10 I. Non-Structural BMPs Non-structural BMPs are generally managerial, educational, inspection and/ or maintenance oriented. These items consist of educating employees and occupants, developing, and implementing HOA guidelines, implementing BMPs and enforcing Code requirements. Non- structural BMPs used for this project are summarized below: Education for Employees and Occupants Practical informational materials will be provided to occupants, the HOA and employees on general good housekeeping practices that contribute to protection of storm water quality. Among other things, these materials will describe the use of chemicals (including household type) that should be limited to the property, with no discharge of specified wastes via hosing or other direct discharge to gutters, catch basins and storm drains. This program must be maintained, enforced, and updated periodically by the HOA. Educational materials including, but not limited to, the materials included in the Appendix F of this plan will be made available to the employees and contractors of the HOA. Activity Restrictions Activities on this site will be limited to activities related to residential living. The Conditions, Covenants, and Restrictions (CC&Rs) will outline the activities that are restricted on the property. Such activities related to the LID include car washing, car maintenance and disposal of used motor fluids, pet waste cleanup, and trash container areas. Common Area Landscape Management Management programs will be designed and established by the HOA, who will maintain the common areas within the project site. These programs will include how to mitigate the potential dangers of fertilizer and pesticide usage, require that fertilizer and pesticide usage shall be consistent with City and County guidelines, discuss utilization of water-efficient landscaping practices, require that maintenance be consistent with any Los Angeles County water conservation resolutions or City of Rosemead equivalent, and detail the proper disposal of landscape wastes. Ongoing maintenance will be consistent with the State of California Model Water-Efficient Landscape Ordinance. Fertilizer and pesticide usage shall be consistent with County Management Guidelines for use of Fertilizers and Pesticides. Common Area Litter Control The HOA will be required to implement trash management and litter control procedures in the common areas aimed at reducing pollution of drainage water. The HOA may also contract with their landscape maintenance firm to provide this service during regularly scheduled maintenance, which should consist of litter patrol, emptying of trash receptacles in common areas, and noting trash disposal violations and reporting the violations to the HOA for remediation. Street Sweeping in Private Streets and Parking Lots The HOA shall have all streets and parking lots swept on a weekly basis. This procedure will be intensified around October 15th of each year prior to and throughout rainstorm period. Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 11 Drainage Facility Inspection & Maintenance The HOA will be responsible for implementing each of the BMPs detailed in this plan. The HOA will also be responsible for cleaning and maintaining the BMPs on a regular basis. Refer to Appendix G for the Operation and Maintenance Plan. Refer to Appendix B for site specific drainage BMP information. Title 22 CC&R Compliance The HOA will comply with this Regulation as part of the development’s CC&Rs. CC&Rs will be prepared as a separate document and reviewed by the City’s Attorney. Uniform Fire Code Implementation The HOA will comply with this Code as part of the development’s CC&Rs. CC&Rs will be prepared as a separate document and reviewed by the City’s Attorney Employee Training/Education Program A training program will be established as it would apply to future employees, contractors, and homeowners of the HOA to inform and train in maintenance activities regarding the impact of dumping oil, paints, solvents, or other potentially harmful chemicals into storm drains; the proper use of fertilizers and pesticides in landscaping maintenance practices; and the impacts of littering and improper water disposal. The HOA (or a hired firm) will conduct the training program which will include targeted training sessions with specific construction disciplines (landscaping, concrete finishers, painters, etc.). See Appendix F for examples of educational materials that will be provided to the Employees. The project’s O&M will include provisions for future employee training programs conducted on a yearly based prior to the rainy season. J. BMP Maintenance, Inspection, and Repair Inspections will be conducted as follows:  Annually prior to the start of the rainy season (Oct. 1st- May 31st)  Every (1) month during rainy season  At any other time(s) or intervals of time specified in the contract documents An inspection form shall be completed at least once per year prior to the start of the rainy season. This inspection check sheet (see Appendix G) shall be included in this report and always kept onsite. The check sheet should be filled out completely and clearly indicate any BMPs that need repair or maintenance. These repairs and/ or maintenance procedures shall be carried out at the soonest possible time. A legible log shall be kept on site to record the inspection of the storm water pollution abatement control measures. The record must contain the following information: (i) type of maintenance activities or source-control practices; (ii) date the activities are completed; and (iii) the name of the operator performing the activities. During transfer of ownership/operation of the facility, the Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 12 current owner must notify the new owner/operator of the BMPs and the associated maintenance activities that also transfer to the new owner/operator of the property. See Appendix G. K. Inspection, Maintenance, and Responsibility for BMPs The following tables list the post-construction BMPs (routine non-structural and structural), the required ongoing maintenance, the inspection and maintenance frequency, the inspection criteria, and the entity or party responsible for implementation, maintenance, and/or inspection. Table-4: Non-Structural BMP Maintenance Responsibility/Frequency Matrix BMP RESPONSIBILITY FREQUENCY Homeowner/ Business owner Education, Activity Restrictions HOA will provide educational materials. Those materials and responsibilities must be passed onto subsequent property owners. Continuous. CC&Rs to be provided to homeowners at the time they purchase the property and updates provided by the HOA as they occur. Common Area Landscape Management HOA will appoint a landscape maintenance contractor Monthly during regular maintenance and use with management guidelines for use of fertilizers and pesticides. Parking Areas and Drives Management HOA will appoint a landscape maintenance contractor The Drives Aisles are to be swept on a routine scheduled basis to facilitate the pickup of trash and debris (plant or otherwise) and to remove excessive oil, grease, and build-up. During sweeping, debris is to be removed from the parking areas and drives and then scrubbed and rinsed. This sweeping schedule will be at a minimum occurrence of once a week and as necessary to rid / reduce active pollutants from the pavement areas. This maintenance requirement will be listed in the Convent, Conditions and Restrictions (CC&Rs) of this project. These CC&Rs will be recorded to the property at the County Recorder’s Office and be included on the final Title report of these properties. Litter Control by Sweeping HOA will appoint a landscape maintenance contractor. Weekly inspection of trash receptacles to ensure that lids are closed and pick up any excess trash on the ground, noting trash disposal violations to the HOA for remediation. Employee Training HOA will appoint a landscape contractor after construction. Monthly for maintenance personnel and employees to include the educational materials contained in the approved LID. Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 13 BMP RESPONSIBILITY FREQUENCY Common Area Catch Basin Inspection & Cleaning HOA will appoint a landscape maintenance contractor for common areas and storm drain facilities. Inspect basins once a month. Clean debris and silt in bottom of catch basins as needed. Intensified on or about October 15th each year or prior to the first 24-hour storm event, whichever occurs first. Refer to Appendix E. Table-5: Structural BMP Maintenance Responsibility/Frequency Matrix BMP RESPONSIBILITY FREQUENCY Common Area Efficient Irrigation HOA will appoint a landscape contractor after construction Once a week, in conjunction with maintenance activities. Verify that runoff minimizing landscape design continues to function by checking that water sensors are functioning properly, that irrigation heads are adjusted properly to eliminate overspray to hardscape areas, and to verify that irrigation timing and cycle lengths are adjusted in accordance with water demands, given time of year, weather and day or nighttime temperatures. Common Area Runoff Efficient Landscape Design HOA will appoint a landscaping contractor Once a week in conjunction with maintenance activities and prior to finalizing any replanting schemes. Verify that plants continue to be grouped according to similar water requirements to reduce excess irrigation runoff. Catch Basin Stenciling HOA A warning stencil will be painted on top and in view with the words: “No-Dumping – Drains to Ocean” At all catch basin, drain inlets draining to the street or storm drain system. See Appendix “B” (example). Once every 6 months, inspect for re- stenciling needs. Re-stencil as needed immediately. Maxwell Plus Drywell System HOA Maxwell Plus Drywell System maintenance will conform to manufacturer’s specifications. Please see additional information in Appendix C Stormwater Detention System HOA Stormwater detention system maintenance will conform to manufacturer’s specifications. Oldcastle FloGard Catch Basin Insert Filters HOA Oldcastle FloGard catch basin insert filter maintenance will conform to manufacturer’s specifications. See additional information in Appendix C Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Section 4 Mission Villas, LLC February 2022 Page 14 L. Operation/Maintenance Funding after Project Completion The post-construction BMPs as described above will be funded and maintained by: The Homeowner’s Association Maintenance and requirements of the maintenance for the properties will be listed in the Convent, Conditions and Restrictions (CC&Rs) of this project and will be the responsibility of the property owner at all times. These CC&Rs will be recorded to the property at the County Recorder’s Office and be included on the Title report of these properties. Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Figure -1: Project Vicinity Map Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Figure -2: BMP Exhibit MM// // // // // // //////// // // Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Figure -3: Impaired Waters ?Ý !"^$ AÐ %&g( %&g(Aà %&l( %&l( %&l( !"`$ !"`$ !"`$ %&o( %&o( ?q ?q ?º %&e( %&e( ?Õ %&q( %&q( %&d( %&d( ?»?» AË IÄ IÄ Aÿ AVAVBVHUGHES BVDR STSTSTBVNN RDBVF E L I ZLOS AVBVAVR D 6TH PYB VCANYONANGELES M T R E D BOX PY BV TUJUNGA R D BVHY HYRDBV BV BVARTESIA MAGIC WOODMANAVWY BVLABVVAN NUYSRDBVBVMAGNOLIAAVBV STVINELANDAVAVTAMPAMOUNTAIN BV DR COLORADO HUNTINGTON RD L I V EST RD O A KFRANCISQUITOO L D SHERMAN BALBOAFALLBROOKAVM A Y O DRLY O N S AV RDSANDTHE RDSANARROYOA R R O WAV DR FOOTHILL F OOTH I L LSAN FERNANDOBV RDROSCOEBVDEVONSHIRE HY WILSHIRESUNSET BV RD MTBVLAKEBVST IMPERIAL BL VENTURA BLVICTORY WY CARSON COAST 25THST ALAMITOS AVAV BVMAINB ST ST ST ARTESIA BV NORWALKFIRESTONE ATLANTICBVBV BV HYLEFFINGWELLRD BV COLIMANORWALKBV A V AVST CARSON 7TH ATLANTICWILLOW BV HY ST HYPEARBLOSSOM HYSIERRA 87 THST EFORT TEJON H YRDVIRGENESLASCANYONMALIBUMULHOLLANDVALLEYCIRCLE SUNLANDTUXFORDHILL GLENDALEVERDUGOH U N TIN G TO N MISSIONMAIN PECKBO UQUETS O L E D A D CANYON SIERRASECO CYNFERNANDOV A LEN C IA RDSANCANYONCANYON BIG CRESTANGELESFO R E STGLEASONANGELESCRESTFOOT AVWILSON PACIFIC SEPULVEDA HAWTHORNEWESTERNWILMINGTONBRO ADW AYVALLEYMAIN HACIENDALITTLETUJUNGAMANCHESTER BREAROSECRANS O C EA NALA MEDAROSEMEADTOPANGASUNSETCANYON WHITTIER LINCOLN H E N R Y L A S T U N A S DR SLAUSON GLENDORA AVSTGAFFEYSEPULVEDAPACIFICAVLAKEWOODBVCOUNT YORANGES A N TA CLA R A RIVERS A N TA CLARA RIV E RLOS ANGELES RIV E R LOS ANGELESRIVERRIVERLOS ANGELESSANGABRIELRIVERSA NGABRIELRIVERW EST SAN GABRIE L ENCINORESERVOIR UPPERFRANKLINRESERVOIR HOLLYWOODRESERVOIR SILVER LAKERESERVOIR LEGG LAKE BIGSANTAANITARESERVOIR SAWPITCANYONRESERVOIR COGSWELLRESERVOIR BIG TUJUNGARESERVOIR PACOIMARESERVOIR HANSENDAM LITTLE ROCKRESERVOIR DRY CANYONRESERVOIR SEPULVEDA FLOODCONTROL BASIN STONECANYONRESERVOIR LOWERFRANKLINCANYONRESERVOIR HARBORLAKE CHATSWORTHRESERVOIR WHITTIER NARROWS DAM SANTA FE DAM EATONWASHDAM DEVIL'SGATEDAM& RES LOS ANGELESRESERVOIR SANTA MONICARUSTICCANYONMANDEVILLE CANYON CHANNELSULLIVAN CANYONCHANNEL CANYON CHANNELR EXF O R D CHANNELCOLDWATERCANYONCHANNELCH AN NELA L H A MB R A BENEDICT CANYONCHANNEL COLDWATERCHANNELB E N E DIC T C A N Y O N C H A N N E L SYCAMORE CANYON ARROYO SECOC R E EK WASH SAN PAS Q UAL MILL CREEKCREEKCABALLEROENCINO CHANNELT U J U N G A W A S H CENTRAL BRANCH WASHB U R B A N K WE S T E R N S Y S T E M V E R D U G O WASH SYCAM ORE W ASHDEAD HORSE CANYON CHANNELSYCAMORE-SCHOLL DIVERSIONROYAL CANYON CHANNELREYNOLDSCOURT LAT CHESEBORO CANYON CHANNEL VAN TASSEL CANYONCHANNELMADDOCKCHANNELSPINKSCHANNELBRADBURYCHANNELDRY CANYONSOUTH FORKDRY CANYON CHANNELS A W TE LLE C H A N N EL ARROYO SECOCHANNEL SCHOLLCHANNEL CHANNEL SYCAMORECANYON CLEMENTSLATERALC A S C A D IA L A T E R A L LENORECHANNELCHANNELBUENA VISTA BUENA VISTACHANNEL SIE R R A M A D R E W A S H SAWPIT WASHBRADBURY CHANNELBALLONA CREEK CREEKARCADIAARCADIA EAST BRANCH WASHBALDWIN AVE.LIMA ST.SAN JOSE PUENTECREEKWASHRUBIOW ASH WASH E A T O N RIO HONDO CHANNELBIG DALTON WASHWALN U T C HA N N EL WALNUT CHANNEL CREEK CRE E K DRAINWILLMINGTONDOMINGUEZ CHANNEL RIO HONDOVERDENORTH FORKTACOBICREEKCOMPTON DOMINGUEZ WASHANDERSONCREEKBALLONA COMPTON CREEKLAGUNADOMINGUEZ F.C.S C H A N N E L EAST BRANCHCHANNELLA MIRADACREEKLA CANADACOYOTECOYOTECREEKC OY O T E LOS CERRITOS CHANNEL ATBELLCHANNEL CENTINELA CREEK SEP ULVE DA C HA N N EL SEPULVEDA CHANNELCREEKCASTAIC SYSTE M W ESTERN BURBANK CHANNEL PEARLAND VIOLIN GOVERNOR CANYON CHANNELACTON CANYONCHANNELACTONCANYONRED ROVERCANYON CHANNELS H A N N O N V ALLEY CANYON BOUQUET CANYONTEXAS CANYON CANYON HASLEY POLE CANYONCANYONMINTCHANNELBOUQUET CANYON SANTA CLARA RIVER SOUTH FORK LIVE OAK S P RIN G S C A N Y O N OAK SPRING CANYON SAND CANYONCREEK PLACERITA SA NTA CLAR A RIV E R S O UTH F O RK CH A N NEL MAY CANYON CHANNELKAGELCANYONCHANNELCHANNEL MANSFIELD BU L L C RE E K R E S E R V OI R B R A N C H EAST CANYON CHANNEL SYLMAR CHANNEL CANYONWILSONSOMBRERO CYNCHANNELSTETSON CYN CHANNELSOMBRERO CHANNELHOG CANYONCHANNELCANYONCHANNELLOPEZDIVERSIONPACOIMABULL CREEK CREEKLIMEKILNEAST BRANCHALISO CREEKHANSENHEIGHTSCHANNEL TUJUNGA WASHPAC OIMACREEK ALISO CREEKLIMEKILN CREEK CREEKWILBURSANTA SUSANA CREEKDAYTON CREEK BULLSOUTH CHANNEL - PACOIMA WASHCHA T S WO RT HCRE E K BELL CREEKCREEK CALABASASCREEKCREEKBROWNSSOUTHB E L L CREEKESCORPIONFORKC R E E KBELL BROWNS CREEKCHIQUITO CANYON SAN MARTINEZ-SPILLWAYCANYON DRYCANYONCANYONSAN FRANCISQUITOHASKELL CANYONNEWHALL IRON CANYONSAND CANYONVASQUEZ CANYON CHANNELP L U M C A N Y O N C H A N N E L RABBIT CANYON SOLEDADCANYON LITTLE ROCK WASHA Q U E D U C TAQUEDUCT CHANNEL CENTRAL BRANCH WASHC H A N D L E R C A N Y O N L IT T L E T U J U N G A W A S H CHANNELL A T U N A C A N Y O N C H A N N E L VERDUGO WASH GOSS CYN.INLETQUAILCREEKCLOUD CREEKCHANNELEAGLE WARDCHANNELCHANNELCANYONDUNSMUIRCHANNELCANYONCOOKSSHIELDS CANYONSUNSET LATALTADE NA SYSTEM RUBIO RUBIODIVERSIONWASHGOOSEBERRYCREEKCHANNEL ROWLEYCANYON ZACHAUCHANNEL BLANCHARDCANYONCHANNELBLUEGUMCANYONCHANNEL WEBBERCANYONCHANNELBURBANK EASTERN SYSTEM CHANNELHILLCRESTBRAND CANYON CHANNELCHILDSCANYON CHANNELELMWOODCANYON CHANNELENGLEHEARDCANYON CHANNEL WASHV E R D U G OMCCLURE CHANLOCKHEEDCHANNEL CHANNELCANYONSTOUGHHAINES CANYONCHANNELPICKENS CANYON CHANNELHALLS CANYON CHANNELWINERY CANYON CHANNELHAY CANYON CHANNELFLINT CANYON CHANNELGOULD CANYONPARADISECANYON CHANNELCHANNELWASHCANYONANITA S A N T A LITTLE CANYONBAILEYSIERRA MADRE VILLA CHANNELCARRIAGE HOUSECANYONAUBURNCHANNELLANNANCHANNELCANYONANITASANTAARCADIACALIFORNIA LATERALWASHPACOIMACREEKWASHSANTAANITACHANNELTEMPLECITY P A C I F I C OC E ANLos Angeles River Watershed LOSANGELES LONGBEACH SANTACLARITA CARSON PASADENA TORRANCE BURBANK WHITTIER DOWNEY COMPTON CALABASAS NORWALK CERRITOS LAKEWOOD INGLEWOOD DUARTE MALIBU ALHAMBRA SOUTHGATE SANTAMONICA LAMIRADA BELL HAWTHORNE MONTEREYPARK ELSEGUNDO SANMARINO GLENDALE MONROVIA ARCADIA IRWINDALE PICORIVERA VERNON MONTEBELLO GARDENA PALMDALE COMMERCE RANCHOPALOSVERDES INDUSTRY ELMONTE LYNWOOD ROSEMEAD BELLFLOWER BALDWINPARK PARAMOUNT SANTAFESPRINGS CULVERCITY REDONDOBEACH BEVERLYHILLS LACANADAFLINTRIDGE WESTCOVINA LOMITA SANGABRIEL LAHABRAHEIGHTS LAPUENTE ARTESIA PALOSVERDESESTATES ROLLINGHILLS LAWNDALEMANHATTANBEACH SOUTHPASADENA SIGNALHILL CUDAHY SOUTHELMONTE ROLLINGHILLSESTATES BELLGARDENS HUNTINGTONPARK HIDDENHILLS SANFERNANDO MAYWOOD WESTHOLLYWOOD HERMOSABEACH HAWAIIANGARDENS PICO LANG ACTON WATTS PALMS ATHENS SAUGUS NAPLES MONETA LENNOX VENICE AGOURA RESEDA NEWHALL SOLEDAD CASTAIC MAYFAIR BASSETT TOPANGA TARZANA TUJUNGA PACOIMA BIG ROCK GLENVIEW VALENCIA PINETREE LAKEVIEW WALTERIA ROSEWOOD EL PORTO FLORENCE CRENSHAW WESTLAKE MID CITY WESTWOOD FERNWOOD VAN NUYS ALTADENA WINNETKA DEL VALLE VAL VERDE SAN PEDRO MIRALESTE DOMINGUEZ HOLLYDALE HYDE PARK VIEW PARK FOX HILLS MAR VISTA KOREATOWN BRENTWOOD ECHO PARK LOS FELIZOLD CANYON AGUA DULCE WILMINGTON OCEAN PARK MONTE NIDO EAGLE ROCK SUN VALLEYNORTHRIDGE WEST HILLS CHATSWORTH OLIVE VIEW MINT CANYON HARBOR CITY WALNUT PARK WILLOWBROOK WESTCHESTER RANCHO PARK SYLVIA PARK CANOGA PARK FORREST PARK BIXBY KNOLLS LEIMERT PARK CITY TERRACECENTURY CITY BEVERLY GLEN VASQUEZ ROCKS PLAYA DEL REY WINDSOR HILLS BALDWIN HILLS BOYLE HEIGHTS CHEVIOT HILLS CASTELLAMMARE HIGHLAND PARK MT WASHINGTONGLASSELL\PARK MOUNT OLYMPUS WARNER CENTER MISSION HILLSGRANADA HILLS CANYON COUNTRY HARBOR GATEWAY MARINA DEL REY JEFFERSON PARK UNIVERSAL CITY VALLEY VILLAGEWOODLAND HILLS CALABASAS PARK SULPHUR SPRINGS STEVENSON RANCH TERMINAL ISLAND NORWOOD VILLAGE ATWATER VILLAGE BEL AIR ESTATES NORTH HOLLYWOOD CASTAIC JUNCTION RANCHO DOMINGUEZ NORTH LONG BEACH MORNINGSIDE PARK HACIENDA HEIGHTS EAST LOS ANGELES HOLLYWOOD RIVIERA SOUTH SAN GABRIELCOUNTRY CLUB PARK PACIFIC PALISADES LAKE VIEW TERRACE BIG MOUNTAIN RIDGE PALISADES HIGHLANDS CALABASAS HIGHLANDS REF: \\pwgisd02\mpmgis$\MPMGIS\projects\mpm\gismaps\wk_2627\lariver_wtrsheds.mxd DATE: 08/22/07 Data contained in this map is produced in wholeor part from the Los Angeles County Departmentof Public Works' digital database. 0 2 41 MILES I Mapping & Property Management Division, Mapping & GIS Services Section LEGEND LOS ANGELES RIVER WATERSHED UNINCORPORATED AREA DAM / LAKE / RESERVOIR MAJOR RIVER MAJOR CHANNEL Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Appendix A: Volume and Flow Rate Calculations and Hydrologic Report The proposed development was analyzed for the 0.75-in storm event and the 85th Percentile storm event using the LACDPW HydroCalc software. The governing stormwater runoff volume between the two storm events was utilized for design. Below is a summary of the HydroCalc outputs: DMA 85th Percentile Storm  0.75-in Storm Governing Volume (cf) Volume (cf) Flowrate (cfs) Volume (cf) Flowrate (cfs) 1 8,629.68 0.5731 7,191.44 0.4485 8,629.69 Refer to LACDPW HydroCalc Output Data within this Appendix for Volume and Flowrate Calculations. Peak Flow Hydrologic Analysis File location: P:/B/BORS-003/Admin/Reports/LID/Preliminary/Appendix A - Calcs/BORS-003 - DMA 1 - 85%.pdf Version: HydroCalc 1.0.3 Input Parameters Project Name BORS-003 Subarea ID DMA 1 Area (ac)3.38 Flow Path Length (ft)714.0 Flow Path Slope (vft/hft)0.009 85th Percentile Rainfall Depth (in)0.9 Percent Impervious 0.86 Soil Type 6 Design Storm Frequency 85th percentile storm Fire Factor 0 LID True Output Results Modeled (85th percentile storm) Rainfall Depth (in)0.9 Peak Intensity (in/hr)0.2152 Undeveloped Runoff Coefficient (Cu)0.1 Developed Runoff Coefficient (Cd)0.788 Time of Concentration (min)35.0 Clear Peak Flow Rate (cfs)0.5731 Burned Peak Flow Rate (cfs)0.5731 24-Hr Clear Runoff Volume (ac-ft)0.1981 24-Hr Clear Runoff Volume (cu-ft)8629.6809 Peak Flow Hydrologic Analysis File location: P:/B/BORS-003/Admin/Reports/LID/Preliminary/Appendix A - Calcs/BORS-003 - DMA 1 - .75in.pdf Version: HydroCalc 1.0.3 Input Parameters Project Name BORS-003 Subarea ID DMA 1 Area (ac)3.38 Flow Path Length (ft)714.0 Flow Path Slope (vft/hft)0.009 0.75-inch Rainfall Depth (in)0.75 Percent Impervious 0.86 Soil Type 6 Design Storm Frequency 0.75 inch storm Fire Factor 0 LID True Output Results Modeled (0.75 inch storm) Rainfall Depth (in)0.75 Peak Intensity (in/hr)0.1684 Undeveloped Runoff Coefficient (Cu)0.1 Developed Runoff Coefficient (Cd)0.788 Time of Concentration (min)40.0 Clear Peak Flow Rate (cfs)0.4485 Burned Peak Flow Rate (cfs)0.4485 24-Hr Clear Runoff Volume (ac-ft)0.1651 24-Hr Clear Runoff Volume (cu-ft)7191.4357 Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Appendix B: Site BMPs 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 x The signs must be placed so they are easily visible to the public. x Be aware that signs placed on sidewalk will be worn by foot traffic. Design Specifications x Signs with language and/or graphical icons that prohibit illegal dumping,mustbe 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. x 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 x Do not allow irrigation runoff from the landscaped area to drain directly tostorm drain system. x Minimize use of fertilizer, pesticides, and herbicides on landscaped areas. x Plan sites with sufficient landscaped area and dispersal capacity (e.g.,ability to receive irrigation water without generating runoff). x Consult a landscape professional regarding appropriate plants, fertilizer, mulching applications, and irrigation requirements (if any) to ensure healthy vegetation growth. Design Specifications x Choose plants that minimize the need for fertilizer and pesticides. x Group plants with similar water requirements and water accordingly. x Use mulch to minimize evaporation and erosion. x Include a vegetative boundary around project site to act as a filter. x Design the irrigation system to only water areas that need it. x Install an approved subsurface drip, pop-up, or other irrigation system. 1 The irrigation system should employ effective energy dissipation and uniformflow spreading methods to prevent erosion and facilitate efficient dispersion. x Install rain sensors to shut off the irrigation system during and after storm events. x Include pressure sensors to shut off flow-through system in case of sudden pressure drop. A sudden pressure drop may indicate a broken irrigation heador water line. x 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 x 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 x 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 County of Los Angeles D-21 February 2014 S-9: Building Materials Selection Purpose Building materials can potentially contribute pollutants of concern to stormwater runoff through leaching. For example, metal buildings, roofing, and fencing materials may be significant sources of metals in stormwater runoff, especially due to acidic precipitation. The use of alternative building materials can reduce pollutant sources in stormwater runoff by eliminating compounds that can leach into stormwater runoff. Alternative building materials may also reduce the need to perform maintenance activities (i.e., painting) that involve pollutants of concern, and may reduce the volume of stormwater runoff. Alternative materials are available to replace lumber and paving. Design Specifications Lumber Decks and other house components constructed using pressure-treated woodthatis typically treated using arsenate, copper, and chromium compounds are hazardous to the environment. Pressure-treated wood may be replaced with cement-fiberorvinyl. Roofs, Fencing, and Metals Minimizing the use of copper and galvanized (zinc-coated) metals on buildings and fencing can reduce leaching of these pollutants into stormwater runoff. The following building materials are conventionally made of galvanized metals: x Metal roofs; x Chain-link fencing and siding; and x Metal downspouts, vents, flashing, and trim on roofs. Architectural use of copper for roofs and gutters should be avoided. As an alternative to copper and galvanized materials, coated metal products are available for both roofing and gutter application. Vinyl-coated fencing is an alternative to traditional galvanized chain-link fences. These products eliminate contact of bare metal with precipitation or stormwater runoff, and reduce the potential for stormwater runoff contamination. Roofing materials are also made of recycled rubber and plastic. Green roofs may be an option. Green roofs use vegetation such as grasses and other plants as an exterior surface. The plants reduce the velocity of stormwater runoff and absorb water to reduce the volume of stormwater runoff. One potential problem with using green roofs in the Los Angeles County area is the long, hot and dry summers, which may kill the plants if they are not watered. See the Green Roof Fact Sheet (RET- 7) in Appendix E. S-9: Building Materials Selection County of Los Angeles D-22 February 2014 Pesticides The use of pesticides around foundations can be reduced through the use of alternative barriers. Sand barriers can be applied around foundations to deter termites, as they cannot tunnel through sand. Metal shields also block termites from tunneling. Additionally, diatomaceous earth can be used to repel or kill a wide varietyofother pests. Maintenance Requirements The integrity of structural elements that are subject to damage (e.g., signs) must be maintained by the owner/operator as required by local codes and ordinances. 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. County of Los Angeles E-32 February 2014 RET-4: Dry Well Description A dry well is a bored, drilled, or driven shaft or hole whose depth is greater than its width. A dry well may either be a small excavated pit filled with aggregate or a prefabricated storage chamber or pipe segment. Dry well design and function are similar to infiltration trenches in that they are designed to temporarily store and subsequently infiltrate stormwater runoff. In particular, dry wells can be used to reduce the volume of stormwater runoff from building roofs. While generally not a significant source of stormwater runoff pollution, roofs are one of the most important sources of new or increased stormwater runoff volume from land development sites. Dry wells can be used to indirectly enhance water quality by reducing the volume of stormwater runoff to be treated by other downstream stormwater quality control measures. A schematic of a typical dry well is presented in Figure E-4. LID Ordinance Requirements Dry wells can be used to meet the on-site retention requirements of the LID Ordinance. Dry wells will prevent pollutants in the SWQDv from being discharged off-site. Advantages · Requires minimal space to install · Low installation costs · Provide groundwater recharge · Reduces peak stormwater runoff flows during small storm events County of Los Angeles Figure E- County of Los Angeles -4. Dry Well Schematic County of Los Angeles . Dry Well Schematic E-33 RETRET-4: Dry Well February 2014 4: Dry Well February 2014 RET-4: Dry Well County of Los Angeles E-34 February 2014 Disadvantages · Is not appropriate for areas with low permeability soils or high groundwater levels · May not be appropriate for industrial sites or locations with contaminated soils or where spills may occur because of the potential threat to groundwater contamination · Cannot receive untreated stormwater runoff except from rooftops · Requires complete reconstruction for failed dry wells · Is not suitable for fill sites or on steep slopes General Constraints and Implementation Considerations · Dry wells can be integrated into open space buffers and other landscape areas. · The potential for groundwater contamination must be carefully considered,. Dry wells are not suitable for sites that: o Use or store chemicals or hazardous materials, unless they are prevented from entering the well; or o Un-remediated “brownfield sites” where there is known groundwater or soil contamination · Dry wells should be sited away from tree drip lines and kept free of vegetation. · If the corrected in-situ infiltration rate exceed 2.4 in/hr, then stormwater runoff may need to be fully-treated with an upstream stormwater quality control measure prior to infiltration to protect groundwater quality. · Dry wells cannot be located on sites with a slope greater than 20 percent (5:1). · Pretreatment to remove sediment is required to protect dry wells from high sediment loads. · If a yard drain is proposed as part of the design, it must be designed so that any standing water in the catch basin will infiltrate within 96 hours. · If possible, the entire tributary area of the dry well should be stabilized before construction begins. If this is not possible, all flows should be diverted around the dry well to protect it from sediment loads during construction or the top two inches of soil from the dry well bottom should be removed after the site has been stabilized. Excavated material should be stored such that it cannot be washed back into the dry well if a storm occurs during construction. · The equipment used to construct the dry well should have extra wide low- pressure tires. Construction traffic should not enter the dry well because it can compact soil, which reduces infiltration capacity. If heavy equipment is used on the base of the dry well, the infiltrative capacity may be restored by tilling or aerating prior to placing the infiltrative bed. RET-4: Dry Well County of Los Angeles E-35 February 2014 · Clean, washed gravel should be placed in the excavated dry well in lifts and lightly compacted with a plate compactor. Use of unwashed gravel can result in clogging. · A geomembrane liner should be installed generously with overlapping seams on sides, bottom, and one foot below the surface of the dry well. · Once construction is complete, stabilize the entire tributary area to the dry well before allowing stormwater runoff to enter it. · An observation well must be installed to check water levels, retention time, and evidence of clogging. · Accessibility for maintenance during dry and wet weather conditions must be provided. Design Specifications The following sections provide design specifications for dry wells. Geotechnical Due to the potential to contaminate groundwater, cause slope instability, impact surrounding structures, and potential for insufficient infiltration capacity, an extensive geotechnical site investigation must be conducted during the site planning process to verify site suitability for a dry well. All geotechnical investigations must be performed according to the most recent GMED Policy GS 200.1. Soil infiltration rates and the groundwater table depth must be evaluated to ensure that conditions are satisfactory for proper operation of a dry well. The project applicant must demonstrate through infiltration testing, soil logs, and the written opinion of a licensed civil engineer that sufficiently permeable soils exist on-site to allow the construction of a properly functioning dry well. Dry wells are appropriate for soils with a minimum corrected in-situ infiltration rate of 0.3 in/hr. The geotechnical report must determine if the proposed project site is suitable for a dry well and must recommend a design infiltration rate (see “Design Infiltration Rate” under the “Sizing” section). The geotechnical investigation should be such that a good understanding is gained as to how the stormwater runoff will move through the soil (horizontally or vertically) and if there are any geological conditions that could inhibit the movement of water. Pretreatment Pretreatment is important for all structural stormwater quality control measures, but it is particularly important for retention facilities. Pretreatment refers to design features that provide settling of large particles before stormwater runoff enters a stormwater quality control measure in order to reduce the long-term maintenance burden. Pretreatment should be provided to reduce the sediment load entering a dry well in order to maintain the infiltration rate of the dry well. To ensure that dry wells are effective, the project applicant must incorporate pretreatment devices that provide sediment reduction (e.g., RET-4: Dry Well County of Los Angeles E-36 February 2014 vegetated swales, vegetated filter strips, sedimentation manholes, and proprietary devices). Setbacks Dry wells must be sited following the setbacks from the most recent GMED Policy GS 200.1. Geometry · Dry well configurations vary, but generally have length and width top dimensions close to a square. Prefabricated dry wells are often circular. · The filter bed media layers must have the following composition and thickness, unless they are prefabricated dry wells: o Top layer: 2 inches of pea gravel o Middle layer: 3 to 5 feet of washed 2- to 6-inch gravel; void spaces should be approximately 30 to 40 percent o Bottom layer: 6 inches of sand or geomembrane liner equivalent. · Gravel media and prefabricated dry wells have porosities of 30 to 40 percent and 80 to 95 percent, respectively. · If a dry well receives stormwater runoff from an underground pipe (i.e., stormwater runoff does not enter the top of the dry well from the ground surface), a fine mesh screen should be installed at the inlet. The inlet elevation should be 18 inches below the ground surface (i.e., below 12 inches of surface soil and 6 inches of dry well media). Sizing Dry wells are sized using a simple sizing method where the SWQDv must be completely infiltrated within 96 hours. Dry wells provide stormwater runoff storage in the voids of the rock fill. Step 1: Determine the SWQDv Dry wells must be designed to capture and retain the SWQDv (see Section 6 for SWQDv calculation procedures). Step 2: Determine the design infiltration rate Determine the corrected in-situ infiltration rate (fdesign) of the native soil using the procedures described in the most recent GMED Policy GS 200.1. RET-4: Dry Well County of Los Angeles E-37 February 2014 Step 3: Calculate the surface area Determine the required size of the infiltration surface by assuming the SWQDv will fill the available void spaces of the gravel storage layer. The maximum depth of stormwater runoff that can be infiltrated within the maximum retention time (96 hrs) is calculated using the following equation: =12 × Where: dmax = Maximum depth of water that can be infiltrated within the required drawdown time [ft]; fdesign = Design infiltration rate [in/hr]; and t = Maximum retention time (max 96 hrs) [hr]. Select the dry well depth (dt) such that: ≤ Where: dt = Depth of dry well fill [ft]; dmax = Maximum depth of water that can be infiltrated within the maximum retention time [ft]; and nt = Dry well fill porosity. Calculate the infiltrating surface area (bottom of the dry well) required: =× Where: A = Surface area of the bottom of the dry well [ft2]; SWQDv = Stormwater quality design volume [ft3]; and dt = Depth of dry well fill [ft]; and nt = Dry well fill porosity. Flow Entrance and Energy Dissipation Energy dissipation controls, constructed of sound materials such as stones, concrete, or proprietary devices that are rated to withstand the energy of the influent flow, must be installed at the inlet to the dry well. Consult with LACDPW for the type and design of energy dissipation structure. RET-4: Dry Well County of Los Angeles E-38 February 2014 Drainage The specifications for designing drainage systems for dry wells are presented below: · The bottom of dry well must be native soil that is over-excavated at least one foot in depth with the soil replaced uniformly without compaction. Amending the excavated soil with two to four inches (~15 to 30 percent) of coarse sand is recommended. · The use of vertical piping, either for distribution or infiltration enhancement, is prohibited. This application may be classified as a Class V Injection Well per 40 CFR Part 146.5(e)(4). · The infiltration capacity of the subsurface layers should be sufficient to ensure a maximum retention time of 96 hours. An observation well must be installed to allow observation of retention time. Hydraulic Restriction Layer The entire infiltrative area, including the side walls must lined with a geomembrane liner to prevent soil from migrating into the top layer and reducing storage capacity. The specifications of the geomembrane liner are presented in Table E-7. The entire well area, including the sides, must be lined with a geomembrane liner prior to placing the media bed. Provide generous overlap at the seams. Table E-7. Geomembrane Liner Specifications for Dry Wells Parameter Test Method Specifications Material Nonwoven geomembrane liner Unit weight 8 oz/yd3 (minimum) Filtration rate 0.08 in/sec (minimum) Puncture strength ASTM D-751 (Modified) 125 lbs (minimum) Mullen burst strength ASTM D-751 400 lb/in2 (minimum) Tensile strength AST D-1682 300 lbs (minimum) Equiv. opening size US Standard Sieve No. 80 (minimum) Observation Well The observation well is a vertical section of perforated PVC pipe, four- to six-inch diameter, installed flush with the top of the dry well on a footplate and with a locking, removable cap. The observation well is needed to monitor the infiltration rate in dry well and is useful for marking the location of the dry well. Vegetation · Dry wells must be kept free of vegetation. RET-4: Dry Well County of Los Angeles E-39 February 2014 · Trees and other large vegetation should be planted away from dry well such that drip lines do not overhang the infiltration area. Restricted Construction Materials Use of pressure-treated wood or galvanized metal at or around a dry well is prohibited. Maintenance Access The dry well must be safely accessible during wet and dry weather conditions if it is publicly-maintained. If the dry well becomes plugged and fails, access is needed to excavate the dry well and replace the filter bed media. To prevent damage and compaction, access must able to accommodate a backhoe working at “arm’s length” from the dry well. Maintenance Requirements Maintenance and regular inspections are important for proper function of dry wells. The following are general maintenance requirements: · Conduct regular inspection and routine maintenance for pretreatment devices. · Inspect dry well and its observation well frequently to ensure that water infiltrates into the subsurface completely within maximum retention time of 96 hours. If water is present in the observation well more than 96 hours after a major storm, the dry well may be clogged. Maintenance activities triggered by a potentially clogged facility include: o Check for debris/sediment accumulation and remove sediment (if any) and evaluate potential sources of sediment and vegetative or other debris (e.g., embankment erosion, channel scour, overhanging trees, etc). If suspected upstream sources are outside of the County's jurisdiction, additional pretreatment operations (e.g., trash racks, vegetated swales, etc.) may be necessary. o Assess the condition of the top aggregate layer for sediment buildup and crusting. Remove the top layer of pea gravel and replace. If slow draining conditions persist, the entire dry well may need to be excavated and replaced. · Eliminate standing water to prevent vector breeding. · Remove and dispose of trash and debris as needed, but at least prior to the beginning of the wet season. A summary of potential problems that may need to be addressed by maintenance activities is presented in Table E-8. The County requires execution of a maintenance agreement to be recorded by the property owner for the on-going maintenance of any privately-maintained stormwater RET-4: Dry Well County of Los Angeles E-40 February 2014 quality control measures. The property owner is responsible for compliance with the maintenance agreement. A sample maintenance agreement is presented in Appendix H. Table E-8. Dry Well Troubleshooting Summary Problem Conditions When Maintenance Is Needed Maintenance Required Trash and Debris Trash and debris > 5 ft3/1,000 ft2 Remove and dispose of trash and debris. Contaminants and Pollution Any evidence of oil, gasoline, contaminants, or other pollutants Remove any evidence of visual contamination. Erosion/Sediment Accumulation Undercut or eroded areas at inlet structures Repair eroded areas and re- grade if necessary. Accumulation of sediment, debris, and oil/grease in pretreatment devices Remove sediment, debris, and/or oil/grease. Accumulation of sediment, debris, and oil/grease on surface or inlet Remove sediment, debris, and/or oil/grease. Water Drainage Rate Standing water, or by inspection of observation wells Remove the top layer of the dry well bottom and replace if necessary. Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Appendix C: Drywell System Information and Sizing VTTM No. 83705 Drywell Calculations CVC Job No. BORS-003 02/15/2022 Page 1 of 2 VTTM No. 83705 8601 Mission Drive, Rosemead, CA Drywell Calculations  Infiltration Rate was determined by project’s geotechnical engineer. The Site is located within Soil Type 6 per LA County Hydrology Maps. The average measured Infiltration Rate of site soils was calculated as 17.0-inches per hour per the Geotechnical Investigation Results prepared by Albus & Associates, Inc. A factor of safety of 2 was applied to the assumed measured rate for a design infiltration rate (KDESIGN) = 8.5 in/hr  All Drywell Systems have been located at least 10’ from building foundations.  The volume statically held within the drywell system includes the volume held by the gravel drywell (void ratio = 0.35) and the volume held by the 10’ sumps below the inlet pipes to the Primary Chamber and the Settling Chamber. Upstream Detention Pipe storage will be provided for the required amount of volume not statically held within each drywell system. Refer to the drywell details on the following pages for more information.  Historic high depth of groundwater is 60’ below existing ground surface. However, per nearby groundwater wells indicate that groundwater is at a depth of 231’ below ground surface. Groundwater was not encountered at a depth of 51.5’ below ground surface during the Geotechnical Investigation conducted by Albus & Associates, Inc.  48-hour Drawdown timeframe utilized DMA A1 A = 3.38 ac DCV = 8,630 cf Maxwell Plus Drywell System with the following properties:  25’ depth* Primary Chamber at 4’ diameter (10’ static storage depth)  25’ depth* Settling Chamber at 4’ diameter (10’ static storage depth)  20’ Drywell at 6’ diameter  Inlet pipe at invert 15’ below FS  ddrywell infiltration= (dsettling-dslurry) + ddrywell = (25’ – 13’) + (20’) = 32’  Total Depth (overall depth) = dsettling + ddrywell = 25’ + 20’ = 45’ Storage Calculations VSETTLING *= πr²(dstatic settling) = π(2 ft)²(10 ft) = 126 cf VPRIMARY *= πr²(dstatic primary) = π(2 ft))²(10 ft) = 126 cf VDRYWELL = πr²(ddrywell infiltration)(n) = π(3 ft)²(25 ft)(0.35) = 198 cf where, r = radius (ft), d = depth (ft), n = Void Space (0.35) per manufacturer’s specifications ∑Volume = 126 cf + 126 cf + 198 cf = 449 cf *Only the portion below the inlet pipe for the Primary Chamber and the Settling Chamber was included for static storage calculation of drywell system. Required Detention Vault Storage = DCV - ∑V = 8,630 cf – 449 cf = 8,180 cf Provided  8’x8’x10’ BioClean Urbanpond Detention System Storage Per Module = 596 cf / module Modules provided = 14 modules VTTM No. 83705 Drywell Calculations CVC Job No. BORS-003 02/15/2022 Page 2 of 2 V = (596 cf / module)*(14 modules) = 8,344 cf > 8,180 cf  Infiltration Calculations V48-HR = (1 ft/ 12 in)(KDESIGN, in/hr)(SA, sf)(48 hr), where SA = Infiltrating Surface Area of Drywell SA = πr² + 2π(r)(ddrywell infiltration) = π(3 ft)² + 2(π)(3 ft)(32 ft) = 631.5 sf where, r = radius (ft), ddrywell infiltration = depth of drywell infiltration zone (ft) V48-HR = (1 ft/12 in)(8.5 in/hr)(631.5 sf)(48 hr) = 21,469 cf > DCV = 8,630 cf  TheMaxWell®Plus,asmanufacturedandinstalledexclusivelyby TorrentResources Incorporated, is the industry standard for draining large paved surfaces,nuisancewaterandotherdemandingapplications.This patentedsystemincorporatesstate-of-the-artpre-treatmenttechnology. THEULTIMATEINDESIGN Since 1974, nearly 65,000 MaxWell®Systems have proven their value as a cost-effective solution in a wide variety of drainage applications. They are acceptedbystateandmunicipalagenciesandareastandarddetailinnumerous drainagemanuals.Manymunicipalitieshaverecognizedtheinherentbenefits oftheMaxWellPlusandnowrequireitfordrainageofallpavedsurfaces. SUPERIORPRE-TREATMENT Industryresearch,togetherwithTorrentResources’ownexperience,haveshown thatinitialstormdrainageflowshavethegreatestimpactonsystemperformance. This“firstflush”occursduringthefirstfewminutesofrunoff,andcarriesthe majority of sediment and debris. Larger paved surfaces or connecting pipes from catch basins, underground storage, etc. can also generate high peak flows which may strain system function. In addition, nuisance water flows requirecontrolledprocessingseparatefromnormalstormrunoffdemands. Inthe MaxWell®Plus,preliminary treatment is provided through collectionandseparationindeeplarge-volumesettlingchambers.Thestandard MaxWellPlusSystemhasover2,500gallonsofcapacitytocontainsedimentand debriscarriedbyincomingwater.Floatingtrash,paper,pavementoil,etc.are effectivelystoppedbythe PureFlo®DebrisShieldsineachchamber.Theseshield- ingdevicesareequippedwithaneffectivescreentofiltersuspendedmaterialand areventedtopreventsiphoningoffloatingsurfacedebrisasthesystemdrains. EFFECTIVEPROCESSING Incomingwaterfromthesurfacegratedinletsorconnectingpipesisreceived in the Primary Settling Chamber where silt and other heavy particles settle to thebottom.APureFloDebrisShieldensurescontainmentbytrappingfloating debrisandpavementoil.Thepre-treatedflowisthenregulatedtoadesignrate ofupto0.25cfsanddirectedtoaSecondarySettlingChamber.Thesettlingand containment process is repeated, thereby effectively achieving controlled, uniformtreatment.ThesystemisdrainedaswaterrisesunderthePureFloDebris Shieldandspillsintothetopoftheoverflowpipe.Thedrainageassemblyreturns thecleanedwaterintothesurroundingsoilthroughtheFloFast®DrainageScreen. ABSORBENTTECHNOLOGY BothMaxWellPlussettlingchambersareequippedwithabsorbentspongesto providepromptremovalofpavementoils.Thesefloatingpillow-likedevicesare 100%waterrepellentandliterallywickpetrochemicalcompoundsfromthewater. Each sponge has a capacity of up to 128 ounces to accommodate effective, long-termtreatment.Theabsorbentiscompletelyinertandwillsafelyremove runoffconstituentsdowntorainbowsheensthataretypicallynomorethanone moleculethick. SECURITYFEATURES MaxWellPlusSystemsincludebolted,theft-deterrent,castirongratingsand covers as standard security features. Special inset castings which are resistant tolooseningfromaccidentalimpactareavailableforuseinlandscaped applica- tions. Machined mating surfaces and “Storm Water Only” wording are standard. ManufacturedandInstalledExclusivelybyTorrentResourcesIncorporated Pleaseseereversesideforadditionalinformation U.S.PatentNo.4,923,330 ® INDUSTRYSERVICES Site Drainage Systems Stormwater Drywells French Drains Piping Drainage Appurtenances Pump Systems Technical Analysis Design Review Percolation Testing Geologic Database ADEQ Drywell Registration Recharge Systems Municipal/Private Recharge Wells Injection Wells & Galleries Environmental Applications Pattern Drilling/Soil Remediation Drainage Rehabilitation Drywell Abandonments OSHA HAZMAT-Certified Drainage Renovation Problem Assessment Site Redesign/Modification System Retrofit Drainage Maintenance Preventive Maintenance Service Contracts Drywell Cleaning TORRENTRESOURCESINCORPORATED 1509 East Elwood Street Phoenix Arizona 85040~1391 phone 602~268~0785 fax 602~268~0820 Nevada 702~366~1234 AZ Lic.ROC070465 A, ROC047067 B-4; ADWR 363 CA Lic.528080 A, C-42, HAZ NV Lic.0035350 A NM Lic.90504 GF04 Thewatermarkfordrainagesolutions.® THEMAXWELLFIVE-YEARWARRANTY Innovative engineering, quality materials and exacting construction are standard with every MaxWell System designed,manufactured and installed by Torrent ResourcesIncorporated. TheMaxWell Drainage SystemsWarrantyisthebest in the industry and guarantees against failures due to workmanship or materials for a period of five years fromdateofcompletion. 1/12 MaxWell®Plus DRAINAGE SYSTEM Product Information and Design Features TORRENTRESOURCES(CA)INCORPORATED phone 661~947~9836 CA Lic.886759 A, C-42 www.TorrentResources.com AnevolutionofMcGuckinDrilling 114188b:0084318b2 1/11/12 1:25 PM Page 1 Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Appendix D: “NO DUMPING – DRAINS TO OCEAN” Stencil Examples Sample Stencil 1 Sample Stencil 2 Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Appendix E: Catch Basin Cleaning GENERAL SPECIFICATIONS FOR MAINTENANCE OF FLO-GARDTM+PLUS CATCH BASIN INSERT FILTERS SCOPE: Federal, State and Local Clean Water Act regulations and those of insurance carriers require that stormwater filtration systems be maintained and serviced on a recurring basis. The intent of the regulations is to ensure that the systems, on a continuing basis, efficiently remove pollutants from stormwater runoff thereby preventing pollution of the nation’s water resources. These Specifications apply to the Flo-GardTM +Plus Catch Basin Insert Filter. RECOMMENDED FREQUENCY OF SERVICE: Drainage Protection Systems (DPS) recommends that installed Flo-GardTM +Plus Catch Basin Insert Filters be serviced on a recurring basis. Ultimately, the frequency depends on the amount of runoff, pollutant loading and interference from debris (leaves, vegetation, cans, paper, etc.); however, it is recommended that each installation be serviced a minimum of three times per year, with a change of filter medium once per year. DPS technicians are available to do an on-site evaluation, upon request. RECOMMENDED TIMING OF SERVICE: DPS guidelines for the timing of service are as follows: 1. For areas with a definite rainy season: Prior to, during and following the rainy season. 2. For areas subject to year-round rainfall: On a recurring basis (at least three times per year). 3. For areas with winter snow and summer rain: Prior to and just after the snow season and during the summer rain season. 4. For installed devices not subject to the elements (washracks, parking garages, etc.): On a recurring basis (no less than three times per year). SERVICE PROCEDURES: 1. The service shall commence with collection and removal of sediment and debris (litter, leaves, papers, cans, etc.) and broom sweeping around the drainage inlet. Accumulated materials shall be placed in a DOT approved container for later disposal. 2. The catch basin shall be visually inspected for defects and possible illegal dumping. If illegal dumping has occurred, the proper authorities and property owner representative shall be notified as soon as practicable. 3. The catch basin grate shall be removed and set to one side. Using an industrial vacuum, the collected materials shall be removed from the liner. (Note: DPS uses a truck-mounted vacuum for servicing Flo-Gard TM +Plus catch basin inserts.) 4. When all of the collected materials have been removed, the filter medium pouches shall be removed by unsnapping the tether from the D-ring and set to one side. The filter liner, gaskets, stainless steel frame and mounting brackets, etc. shall be inspected for continued serviceability. Minor damage or defects found shall be corrected on-the-spot and a notation made on the Maintenance Record. More extensive deficiencies that affect the efficiency of the filter (torn liner, etc.), if approved by the customer representative, will be corrected and an invoice submitted to the representative along with the Maintenance Record. 5. The filter medium pouches shall be inspected for defects and continued serviceability and replaced as necessary and the pouch tethers re-attached to the liner’s D-ring. See below. 6. The grate shall be replaced. EXCHANGE AND DISPOSAL OF EXPOSED FILTER MEDIUM AND COLLECTED DEBRIS The frequency of filter medium pouch exchange will be in accordance with the existing DPS-Customer Maintenance Contract. DPS recommends that the medium be changed at least once per year. During the appropriate service, or if so determined by the service technician during a non-scheduled service, the filter medium pouches will be replaced with new pouches and the exposed pouches placed in the DOT approved container, along with the exposed debris. Once the exposed pouches and debris have been placed in the container, DPS has possession and must dispose of it in accordance with local, state and federal agency requirements. Note: As the generator, the landowner is ultimately responsible for the proper disposal of the exposed filter medium and debris. Because the materials likely contain petroleum hydrocarbons, heavy metals and other harmful pollutants, the materials must be treated as an EPA Class 2 Hazardous Waste and properly disposed of. DPS relieves the landowner of the actual disposal task, and provides certification of its completion in accordance with appropriate regulations. DPS also has the capability of servicing all manner of catch basin inserts and catch basins without inserts, underground oil/water separators, stormwater interceptors and other such devices. All DPS personnel are highly qualified technicians and are confined space trained and certified. Call us at (888) 950-8826 for further information and assistance. 05/04/04 Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Appendix F: General Education Materials Wipe pots, pans, and work areas prior to washing. Do not pour cooking residue directly into the drain. Do not pour waste oil directly into the drain, parking lot or street. Do not wash floor mats outside where water will run off directly into the storm drain. Do not rinse spills into the street. 1 2 2 3 3 4 41Dispose of food waste directly into the trash. Avoid using the garbage disposal. Place greasy food in the trash. Clean mats inside over a utility sink. Use dry clean up for spills. Collect waste oil and store for recycling. THE RIGHT WAY THE WRONG WAY Good Cleaning Practices Managing FATS,OIL and GREASE POST IN CLEANUP/WORK AREA www.lacsd.org PUBLIC WORKS County of Los Angeles Department of Public Works For more information call (888) CLEAN LA or visit www.888CleanLA.com 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: 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. 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: SwimmingPool Tips•Make sure allchemicals aredissipated beforedraining a pool orspa •Do not drain poolswithin 5 days ofadding chemicals•Never backwash afilter into the streetor stormdrain •Cleanup chemicalspills withabsorbent, don’twash it down thedrain•Dispose of leftoverchemicals and paintsthrough a licensedhazardous wastedisposal providerFollow these simple steps toprevent stormwater pollution…Stormdrainstake runoffdirectly to creeksand the ocean without treatment.Pool chemicals can harm ournatural creeks and waterways.Anything going into ourstormdrains that isn’trainwater contributes tostormwater pollution, whichcontaminates our creeks andocean, kills marine life andcauses beach closures....not pool chemicalsStorm Drains arefor Rain...SwimmingPool Tips •Make sure all chemicals are dissipated beforedraining a pool or spa •Do not drain poolswithin 5 days of adding chemicals •Never backwash afilter into the street or stormdrain •Cleanup chemical spills with absorbent, don’twash it down the drain •Dispose of leftoverchemicals and paints through a licensedhazardous waste disposal provider Follow these simple steps to prevent stormwater pollution… Printed on recycled paper Stormdrainstake runoffdirectly to the ocean without treatment. Pool chemicalscan harm our natural creeks and waterways. Anythinggoing into our stormdrains that isn’t rainwatercontributes to stormwater pollution, which contaminates our creeks and ocean, killsmarine life and causes beach closures. ...not pool chemicals Storm Drains arefor Rain... 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. Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Appendix G: Operation and Maintenance Plan To be provided during Final Engineering Preliminary Low Impact Development Plan 8601 Mission Drive Rosemead, California Mission Villas, LLC February 2022 Appendix H: Geotechnical Report 1011 N. Armando Street, Anaheim, CA 92806-2606 (714) 630-1626 October, 27, 2021 J.N.: 3016.00 Mr. Erik Pfahler Borstein Enterprises 11766 Wilshire Boulevard, Suite 820 Los Angeles, CA 90025 Subject: Preliminary Geotechnical Investigation for Proposed Water Quality Improvements, Proposed Residential Development, 8601 Mission Drive, Rosemead, California Dear Mr. Pfahler, Albus & 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 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 8601 Mission Drive within the city of Rosemead, California. The APN parcel numbers for the current development are 5389-009-029, -030, and -031. The property is bordered by Mission Drive to the south, Walnut Grove Avenue, an existing easement for power lines, and a nursery to the west, and single-family residences to the north and east. The location of the site and its relationship to the surrounding areas are shown in Figure 1, Site Location Map. The site consists of an irregularly-shaped property containing approximately 3.35 acres of land. The site is relatively flat with elevations ranging from 357 to 363 feet above mean sea level (based on Google Earth) and slopes gently down to the south. The site is currently vacant land with some improvements onsite. The perimeters of the site are bounded by chain-link fencing, masonry block walls, and plastic fencing. A short concrete driveway is located to the south and west. Along the southwest boundary of the property is existing overhead powerlines. Vegetation within the site consists of minor ground cover and some large palm trees within the southwest portion of the site. Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 2 ALBUS & ASSOCIATES, INC. © 2021 Google N FIGURE 1-SITE LOCATION MAP Proposed Residential Development 8601 Mission Drive, Rosemead, California NOT TO SCALE Proposed Development Based on our understanding, site development is anticipated to consist of multi-story (2 to 3), wood- framed buildings at grade. Associated interior driveways, decorative hardscape, parking areas and underground utilities are also anticipated. No grading or structural plans were available in preparing this proposal. However, we anticipate some minor cut and filling of the site will be required to achieve future surface configuration and we expect future foundation loads will be moderate. SITE Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 3 ALBUS & ASSOCIATES, INC. SUMMARY OF FIELD AND LABORATORY WORK Subsurface Investigation Subsurface exploration for this investigation was conducted on September 7, 2021, and consisted of drilling six (6) soil borings to depths ranging from approximately 11.5 to 51.5 feet below the existing ground surface (bgs). The borings were drilled using a truck-mounted, continuous flight, hollow- stem-auger drill rig. A representative of Albus & Associates, Inc. logged the exploratory borings. Visual and tactile identifications were made of the materials encountered, and their descriptions are presented in 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 borings 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. Two additional borings (P-1 and P-2) were drilled adjacent to boring B-1 for percolation testing. Upon completion of drilling, well materials were installed within P-1 and P-2 for subsequent percolation testing. Construction details for P-1 and P-2 consisted of 15 and 30 feet of well materials. The bottom 5 feet for both wells utilized perforated 3-inch-diameter pipe with the remaining well utilizing solid 3-inch-diameter pipe to ground surface. The joints between pipes were reinforced with duct tape and the sections of perforated pipe were covered with filter sock. After installation of pipe, ¾” gravel was used to fill the annular space around the perforated sections. Upon completion of testing, all well materials were removed from the borings and then backfilled with soil cuttings. Percolation Testing Percolation testing was performed on September 7, 2021, 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 10 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. A filling hose was used to connect the flowmeter and the test wells. Water was introduced by the filling hose near the bottom of the test wells. 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 wells was terminated upon either completion of testing of all the pre-determined water levels or the flow rate exceeded the maximum capacity of the flowmeter. Measurements obtained during the percolation testing are provided in Appendix C on Plates C-1 and C-2. Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 4 ALBUS & ASSOCIATES, INC. 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 contents and dry densities, 200 washes and sieve analyses. Results of laboratory testing relevant to percolation characteristics are presented in Appendix B and on the Exploration Logs in Appendix A. ANALYSIS OF DATA Subsurface Conditions Review of the Diblee Map for the El Monte and Baldwin Park Quadrangles shows the site is designated as Quaternary Alluvium and falls within a flood plain and would have been subjected to seasonally- deposited materials associated with heavy rains from nearby mountain ranges to the north. Our exploration encountered artificial fills overlaying alluvial soils. 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. Fills up to about 2 feet thick appear to be present on site due to previous site improvements and grading. Fill materials typically consisted of fine to medium-grained silty sands. Alluvium was encountered underlying the artificial fill and generally consisted of interlayered silty sands, sands with silt, gravelly sands, and clayey sands. These materials were typically medium dense to very dense and damp. Alluvial soils were encountered to the maximum depth explored (51.5 feet). Within borings B-2 and B-3, cobbles were encountered at depths of approximately 10 feet. Due to the size of the cobbles, the hollow stem could not extract all the cobbles. As such, the cobbles generally remained within the borings and floated within the cuttings and around the stem. Sizes were either measured or visually observed within the boring shaft and are estimated to be 4 to 6 inches in diameter. Groundwater Groundwater was not encountered during this firm’s subsurface exploration to a depth of 51.5 feet. The CDMG Special Report 024 suggests that historic high groundwater for the subject site is approximately 60 feet. However, review of the Los Angeles County groundwater level data for the nearby well 2920G indicates that groundwater for the area is 231 feet below ground surface as of 2018. Well readings have been recorded from 5/1/1949 to 4/26/2018, and during this period, groundwater has fluctuated, but has continued to increase in depth from 126 feet (bgs) to 231 feet (bgs) during this time period. The last recorded reading at the time of this report was April 26, 2018 and indicated a depth of 231 feet. Percolation Data Analyses were performed to evaluate permeability using the flow rate obtained at the end of the constant-head stage of field percolation testing. These analyses were 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. Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 5 ALBUS & ASSOCIATES, INC. Using the USBR method, we calculated a composite permeability value for the head conditions maintained in the wells. The results are summarized in Table 1 below and the supporting analyses are included in Appendix C, Plates C-3 and C-4. Comparing the results of grain-size testing confirms the field test results are appropriate for the soils tested. TABLE 1 Summary of Back-Calculated Permeability Coefficient Test Well 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 14.7 12 2.7 4.7 18.34 P-2 30 27 3 0.68 2.26 Design of Dry Well The infiltration rate in a dry well is dependent upon several factors including the soil permeabilities of the various soil layers throughout the soil mass, hydraulic gradient of water pressure head in the soil mass, and depth to groundwater. The infiltration rate is related to the permeability by Darcy’s equation: V  ki Where: V= water velocity (infiltration rate) k= permeability i=hydraulic gradient The presence of differing soil layers with differing permeabilities, the variable head condition in the well shaft, and presence of ground water are factors that make determining the effective infiltration rate of a dry well somewhat complicated. We have performed the Well Permeameter tests in accordance with the test method. This test provides a means to estimate the Permeability Rate of the soils influencing the dry well, not the infiltration rate. Therefore, the effective infiltration rate must be determined using the relationship between permeability and infiltration rate as expressed by Darcy’s equation. Solution of the Darcy equation essentially requires solving a differential mass balance equation. Due to these complications, the infiltration characteristics of the proposed dry well were modeled using a computer program. Infiltration in a dry well was modeled using the software Seep/W, version 2007, by Geo-Slope International. The program allows for modeling of both partially-saturated and saturated porous medium using a finite element approach to solve Darcy’s Law. The program can evaluate both steady- state and transient flow in planar and axisymmetric cases. Boundaries of the model can be identified with various conditions including fix total head, fix pressure head, fix flow rate, and head as a function Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 6 ALBUS & ASSOCIATES, INC. of flow. Soil permeability properties can be modeled with either Fredlund et al (1994), Green and Corey (1971), Van Genuchten (1980), or Saxton et al. (1986). Only saturated permeabilities were used in our analyses. A Seep/W model was setup with the bottom of the dry well at a depth of 40 feet below ground surface. The dry well was assumed to consist of a shaft that is 6 feet in diameter and contains a settling chamber having an inside diameter of 4 feet, outside diameter of 4.5 feet, and length of 18 feet. The annular space around the chamber between the depths of 0 and 13 feet was assumed to consist of a cement slurry. A more detailed model of the dry well design can be found on Plate 2. The model consisted of three zones of material to represent the general soil profile. The saturated permeability of material 1 was modeled to be impermeable and represent the future artificial fills. The saturated permeability of the primary infiltration zones, materials 2 and 3, were selected based on the coefficient of permeability estimated from percolation tests as well as laboratory gradation test results. The saturated permeability of material 4 was modeled to represent the clayey sand materials encountered at depth. The permeability values are summarized in Table 2. TABLE 2 Summary of Permeability Values Depth (ft) Material No. Material Type Sat. Perm., Ks (in/hr) 0-5 1 Fill 0.001 5-15 2 SW 15 15-45 3 SP/SM 2 >45 4 SC 0.01 Water in the well was assumed to be at a depth of 7 feet below the ground surface so a fix-head boundary was set with a total head elevation of 93 feet around the edge of the well (ground surface was set to an elevation of 100 feet). A steady state analysis was performed to estimate the maximum inflow that the well can accommodate. Using a well as described above, we obtain a static total flow of 0.16 ft³/sec. A plot depicting the resulting pressure head contours and flow vectors for the model is provided on Plate C-5. The average infiltration rate can be determined by taking the flow rate divided by the wetted surface area. The surface area is equal to 395.8 square feet which includes the side and bottom area. Based on the above flow rate and surface area, the average “measured” infiltration rate across the wetted surface area is 17.0 in/hr. To evaluate the time required to empty the well once no more water is introduced, the model was reanalyzed with a variable head condition that was dependent upon the volume of water leaving the well. As water infiltrates into the surrounding soil, the volume of water remaining in the well is reduced as well as the resulting water head. A graph of the well head versus exit volume is provided Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 7 ALBUS & ASSOCIATES, INC. in Figure 2. The function assumes a void ratio of 0.4 within the zones occupied by gravel. If some other well configuration is used, then the analyses will require updating. The analysis was performed as a transient case over a total time of 2.5 hours. The conditions in the model were evaluated in 10 increments of time over the total duration. From our analyses, the water is evacuated from the chamber in approximately 0.55 hours. Plots depicting the resulting pressure head contours and flow vectors at selected times are provided in Appendix C on Plates C-6 through C-9. A plot of time versus water height in the well is shown on Figure 3. FIGURE 2- Well Head versus Exit Volume FIGURE 3- Water Head Versus Time 60 65 70 75 80 85 90 95 0 50 100 150 200 250 300Total Head (ft)Volume (ft3) 0 5 10 15 20 25 30 35 40 00.511.522.5Height of Water in Well (ft)Time (hrs) Water Chamber Bottom Chamber Empty Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 8 ALBUS & ASSOCIATES, INC. CONCLUSIONS AND RECOMMENDATIONS Dry Well Results of our work indicate a storm water disposal system consisting of a dry well is feasible at the site. The use of a dry well is not anticipated to result in worsening any adverse conditions or hazards that may be present for the proposed site development or adjacent properties including subsidence, landsliding, or liquefaction. As discussed above, the historic groundwater level in this area is approximately 60 feet. However, based on the aforementioned well data, we estimate that groundwater is currently at least 230 feet below ground surface and we anticipate will remain at least 200 feet below ground surface for the life of the project. Therefore, a dry well having a total depth of 40 feet will maintain a clearance above groundwater greater than the minimum required clearance of 10 feet. Based on the results of percolation testing and analyses, the well configuration as depicted on Plate 2 may utilize a “measured” peak flow rate of 0.16 ft³/sec. This flow rate corresponds to an average peak infiltration rate of 17.0 in./hr. This flow rate and infiltration rate only apply to the well configuration evaluated and will differ for other configurations. These values are “measured” values and as such, an appropriate factor of safety should be applied to determine the “design” rates. The design infiltration rate requires the application of a Reduction Factor in accordance with the County of Los Angeles GS200.2 guidelines. Based on the county requirements, the reduction factor (safety factor) is determined by multiplying the partial reduction factors as indicated in Table 3 below. The RFt value is prescribed by the test method used. The RFv value is based on the fact that soil conditions are uniform within the infiltration zone, that a test was performed in close proximity to the proposed dry well location, and correlations with laboratory testing of site materials confirm the selected permeability rate obtained by the field test. The RFs value is based on the dry well providing a chamber that traps sediments and removes oils via an absorptive pillow or some other system providing for the removal of most sediment and oils before entering the dry well. TABLE 3 Reduction Factor Factor Value RFt 2.0 RFv 1.0 RFs 1.0 Total Reduction Factor (RF) 2.0 Note: Total Reduction Factor, RF= RFt x RFv x RFs Based on the above reduction factor, design of the system should be based on a peak “design” flow of 0.16 cfs/2.0 = 0.08 cfs. Once water flow to the well has ceased, we estimate the time to empty the chamber will be approximately 0.55 hours. The maximum volume that can be infiltrated by the dry well is defined by the following equation: Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 9 ALBUS & ASSOCIATES, INC. 𝑉் ൌ ሺ𝑇஽ െ𝑇ௐሻ ∙𝑄ௐ ൅𝑉ௐ Where: VT= Total volume infiltrated TD= Allowable drawdown time of system TW= Time to empty well chamber QW= Design flow rate of well VW= Storage volume of dry well Assuming an allowable total drawdown time of 96 hours, the maximum total design capture volume (DCV) one dry well can dispose would be approximately (96-0.55) hrs x 0.08 cfs x 3600 s/hr = 27,490 cubic feet. The effective storage capacity of the dry will is 285 cubic feet. The well should be located at least 10 feet horizontally from any habitable structure. The actual flow capacity of the dry well could be less or more than the estimated value. As such, provisions should be made to accommodate excess flow quantities in the event the dry well does not infiltrate the anticipated amount. The design also assumes that sediments will be removed from the inflowing water through an upper chamber or other device. Sediments that are allowed to enter the dry well will tend to degrade the flow capacity by plugging up the infiltration surfaces. In general, the dry well shaft is anticipated to be adequately stable under temporary construction conditions for uncased drilling. However, friable materials are present and will likely slough during drilling. The contractor should be prepared to install the gravel and chamber immediately following the drilling of the shaft. Workers should not enter the shaft unless the excavation is laid back or shored in accordance with OSHA requirements. The placement and compaction of backfill materials, including the gravel and slurry, should be observed by the project geotechnical consultant. Chamber A buried chamber system may be used in lieu of a dry well. Infiltration of storm water using a buried chamber is not anticipated to result in adverse geotechnical conditions at the site or surrounding sites including subsidence, landsliding, or liquefaction. Using a system that is founded at a depth of at least 5 feet below current grade, we recommend a “measured” infiltration rate of 2.0 in./hr. Applying the required reduction factor of 2 as previously discussed, we obtained a Design Infiltration Rate of 1.0 in./hr. The chambers should be located at least 10 feet horizontally from any habitable structure or property boundaries but otherwise can generally be located anywhere else on the property. The excavations for the chamber system should be observed by the project geotechnical consultant to confirm they expose native alluvial soils at the bottom and are consistent with the conditions anticipated herein. Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 10 ALBUS & ASSOCIATES, INC. 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. 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 Borstein Enterprises 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 & ASSOCIATES, INC. David E. Albus Principal Engineer GE 2455 Enclosures: Plate 1- Geotechnical Map Plate 2- Dry Well Diagram Appendix A - Exploratory Logs Appendix B – Laboratory Testing Appendix C - Percolation Testing and Analyses Borstein Enterprises October 27, 2021 J.N.: 3016.00 Page 11 ALBUS & ASSOCIATES, INC. REFERENCES Publications and Reports California Department of Conservation, Division of Mines and Geology, Seismic Hazard Report 024, "Seismic Hazard Zone Report for the El Monte 7.5-Minute Quadrangle, Los Angeles County, California", 1998. Los Angeles County Department of Public Works Well Data (accessed 2020): https://dpw.lacounty.gov/general/wells/ Procedure for Performing Field Permeability Testing by the Well Permeameter Method, by United States Department of The Interior, Bureau of Reclamation (USBR 7300-89). Guidelines for Geotechnical Investigation and Reporting Low Impact Development Stormwater Infiltration, by County of Los Angeles, Department of Public Works, Geotechnical and Materials Engineering Division (GS200.2). APPROXIMATEPROJECT SITE LIMITSB-1P-2P-1B-2B-3B-4B-5B-6EXPLANATION(Locations Approximate)0 50 100 200APPROX SCALE : 1" = 100'- Exploratory Boring- Percolation Test Boring1Plate:Date: 10/27/20213016.00Job No.:GEOTECHNICAL MAP©Google 2021 ALBUS & ASSOCIATES, INC. APPENDIX A EXPLORATORY LOGS Field Identification Sheet Light gray Description Order: Description, Color, Moisture, Density, Grain Size, Additional Description Gray Description % 0-5 trace 5-15 Dark gray with 15-30 30+Gravelly Sand with Silt trace Clay Moisture Silty Clay with Sand trace Gravel Gray Brown Dry Damp Moist Light brown Very Moist Wet Brown Density (Navfac) SPT CA 0-3 0-5 Dark Brown 3-8 5-13 8-14 13-22 14-25 22-40 Olive brown 25> 40> 2< 0-3 Olive 2-4 3-6 4-8 6-13 8-15 13-24 Yellow 15-30 24-48 30> 48> Yellowish brown Grain Size Description Sieve Size Approx. Size >12" Larger than basketball Yellowish red 3-12" Fist to basketball coarse 3/4-3" Thumb to Fist fine #4-3/4" Pea to Thumb Red coarse #10-4 Rock Salt to Pea medium #40-10 Sugar to Rock Salt fine #200-40 Flour to Sugar Reddish Brown Pass #200 Smaller than Flour Additional Description (ie. roots, pinhole pores, debris, etc.) Tan Trace 5% Moderate 15% Abundant 30% Albus & Associates, Inc. Plate A-0 absence of water near optimum below optimum Very Loose Sand Sand trace Silt Sand with Silt Silty Sand Example Very Soft Soft Stiff above optimum free water visible Loose Medium Dense More Examples Fines Sand Gravel Sand with Silt and Clay Sand trace Silt and Clay Sand with Silt trace Clay Very Stiff Hard Fine grained soils Medium Stiff Boulders Cobbles Dense Coarse grained soils Very Dense 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 & 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 8601 Mission Dr, Rosemead, CA 3016.00 9/7/2021 ddalbusHollow-Stem Auger Borstein Enterprises B-1 358 WaterCoreBulk140 lbs / 30 in 5 10 15 20 25 ARTIFICIAL FILL (Af) Silty Sand (SM):Light brown, dry, fine to medium grained sand ALLUVIUM (Qal) Sand with Gravel trace Silt (SP):Brown to yellowish brown, damp, medium dense, fine to coarse grained sand Sand with Gravel (SP):Yellowish brown, damp to moist, medium dense, fine to coarse grained sand Gravelly Sand (SW):Yellowish brown, damp to moist, medium dense, fine to coarse grained sand @ 10 ft, more coarse grained sand @ 15 ft, dry to damp, very dense Silty Sand (SM):Brown to yellowish brown, moist, very dense, fine grained sand @ 20 ft, medium dense Sand with Gravel trace Silt (SP):Brown, moist, dense, more fine grained sand 34 37 17 10 21 20 28 3.6 2.9 3.2 2.6 117.4 112.4 103.9 112.8 Max EI SO4 DS pH Resist Ch SA Hydro 200 Albus & 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 8601 Mission Dr, Rosemead, CA 3016.00 9/7/2021 ddalbusHollow-Stem Auger Borstein Enterprises B-1 358 WaterCoreBulk140 lbs / 30 in 35 40 45 50 Yellowish brown, very dense, more fine to coarse grained sand Gravelly Sand (SP):Light reddish brown, dry to damp, very dense, fine to coarse grained sand Sand with Silt (SP):Light reddish brown, damp to moist, very dense, fine grained sand Silty Sand (SM):Light reddish brown, damp to moist, very dense, fine grained sand, moderate fines Clayey Sand (SC):Brown to reddish brown, moist, hard, fine grained sand Total Depth 51.5 feet No Groundwater Boring backfilled with soil cuttings 52 49 36 61 30 SA Hydro 200 200 ATT Albus & Associates, Inc.Plate A-3 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 8601 Mission Dr, Rosemead, CA 3016.00 9/7/2021 ddalbusHollow-Stem Auger Borstein Enterprises B-2 357.9 WaterCoreBulk140 lbs / 30 in 5 10 ARTIFICIAL FILL (Af) Silty Sand (SM): Brown, dry, fine grained sand ALLUVIUM (Qal) Silty Sand with Gravel (SM): Brown, damp, medium dense, fine to coarse grained sand Gravelly Sand (SP): Yellowish brown, moist, medium dense, fine to coarse grained sand @ 6 ft, dense, gravel up to 1 inch dia @ 10 ft, medium dense, cobbles observed in cuttings up to 6 inch dia Total Depth 11.5 feet No Groundwater Boring backfilled with soil cuttings 15 28 25 30 2.7 3.3 112.4 200 Albus & Associates, Inc.Plate A-4 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 8601 Mission Dr, Rosemead, CA 3016.00 9/7/2021 ddalbusHollow-Stem Auger Borstein Enterprises B-3 357.9 WaterCoreBulk140 lbs / 30 in 5 10 ARTIFICIAL FILL (Af) Silty Sand (SM): Brown, dry, fine grained sand ALLUVIUM (Qal) Gravelly Sand trace Silt (SP): Yellowish brown, dry to damp, medium dense, fine to coarse grained sand @ 4 ft, damp, loose, no silt, gravel up to 1 inch dia @ 6 ft, moist, medium dense @ 10 ft, 4 inch dia cobble observed in cuttings Total Depth 11.5 feet No Groundwater Boring backfilled with soil cuttings 19 12 27 2.3 3.1 3.4 104.9 109.8 Consol Albus & 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 8601 Mission Dr, Rosemead, CA 3016.00 9/7/2021 ddalbusHollow-Stem Auger Borstein Enterprises B-4 358 WaterCoreBulk140 lbs / 30 in 5 10 ARTIFICIAL FILL (Af) Silty Sand (SM): Brown, dry, fine grained sand ALLUVIUM (Qal) Silty Sand with Gravel (SM): Brown, moist, loose, fine to coarse grained sand Sand with Gravel (SP): Yellowish brown, moist, loose, fine to coarse grained sand @ 6 ft, medium dense @ 10 ft, more coarse grained sand Total Depth 11.5 feet No Groundwater Boring backfilled with soil cuttings 31 15 13 17 3.7 3.8 2.8 4.5 112.9 107.2 105.9 Consol Albus & 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 8601 Mission Dr, Rosemead, CA 3016.00 9/7/2021 ddalbusHollow-Stem Auger Borstein Enterprises B-5 361 WaterCoreBulk140 lbs / 30 in 5 10 ARTIFICIAL FILL (Af) Silty Sand (SM): Brown, dry, fine grained sand ALLUVIUM (Qal) Silty Sand with Gravel (SM): Brown, damp, medium dense, fine to medium grained sand @ 4 ft, Yellowish brown Sand with Gravel (SP): Yellowish brown, moist, medium dense, fine to coarse grained sand Total Depth 11.5 feet No Groundwater Boring backfilled with soil cuttings 17 20 34 3.4 4.6 3.1 108.7 -31.3 111.1 200 Albus & Associates, Inc.Plate A-7 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 8601 Mission Dr, Rosemead, CA 3016.00 9/7/2021 ddalbusHollow-Stem Auger Borstein Enterprises B-6 361.2 WaterCoreBulk140 lbs / 30 in 5 10 ARTIFICIAL FILL (Af) Silty Sand (SM): Brown, dry, fine grained sand ALLUVIUM (Qal) Silty Sand with Gravel (SM): Brown, damp, medium dense, fine to coarse grained sand Gravelly Sand (SP): Yellowish brown, damp, loose, fine to coarse grained sand @ 6 ft, medium dense, more coarse grained sand @ 10 ft, dense, more gravel 46 16 15 24 3.4 2.1 2.4 2.4 103.2 108.5 109.8 200 Albus & Associates, Inc.Plate A-8 Total Depth 11.5 feet No Groundwater Boring backfilled with soil cuttings APPENDIX B LABORATORY TEST PROGRAM Borstein Enterprises October 27, 2021 J.N.: 3016.00 ALBUS & ASSOCIATES, INC. LABORATORY TESTING PROGRAM Soil Classification Soils encountered within the exploratory borings were initially classified in the field in general accordance with the visual-manual procedures of the Unified Soil Classification System (ASTM D 2488). The samples were re-examined in the laboratory and classifications reviewed and then revised where appropriate. The assigned group symbols are presented on the Exploration Logs provided in Appendix A. In-Situ Moisture Content and Dry Density Moisture content and dry density of in-place soil materials were determined in representative strata. Test data are summarized on the Exploration Logs, Appendix A. Atterberg Limits Atterberg Limits (Liquid Limit, Plastic Limit, and Plasticity Index) were performed in accordance with Test Method ASTM D 4318. Pertinent test values are presented within Table B-1. Particle Size Analyses Particle size analyses were performed on representative samples of site materials in accordance with ASTM D 422. The results are presented graphically on the attached Plates B-1 and B-2. TABLE B-1 SUMMARY OF LABORATORY TEST RESULTS Boring No. Sample Depth (ft) Soil Description Test Results B-1 20 Silty Sand Passing No. 200 Sieve: 43.4 B-1 35 Gravelly Sand trace Silt Passing No. 200 Sieve: 11.1 B-1 45 Sand with Silt Passing No. 200 Sieve: 17.7 B-1 50 Sandy Clay with Silt Liquid Limit (%): Plasticity Index (%): 25 7.2 B-2 10 Gravelly Sand trace Silt Passing No. 200 Sieve: 10.7 B-5 10 Gravelly Sand with Silt Passing No. 200 Sieve: 20.3 B-6 4 Sand trace Silt Passing No. 200 Sieve: 6.2 Note: Additional laboratory test results are provided on the boring logs provided in Appendix A. COARSE FINE COARSE MEDIUM FINE Description Sand with Gravel trace Silt Albus & Associates, Inc.Plate B-1 3016.00 GRAIN SIZE DISTRIBUTION Job Number Location B-1 GRAVELCOBBLES SILT AND CLAYSAND 15 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 Sand with Gravel trace Silt Albus & Associates, Inc.Plate B-2 3016.00 GRAIN SIZE DISTRIBUTION Job Number Location B-1 GRAVELCOBBLES SILT AND CLAYSAND 30 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 CONSOLIDATION Job Number Location Depth 3016.00 B-3 6 Albus & Associates, Inc.Plate B-3 Description Sand 102.5 4 18.2 Initial Dry Density (pcf)Initial Moisture Content (%)Final Moisture Concent (%) 0 1 2 3 4 5 6 7 8 9 10 11 12 100 1000 10000 100000CONSOLIDATION (%)NORMAL STRESS (psf) Field Saturated CONSOLIDATION Job Number Location Depth 3016.00 B-4 6 Albus & Associates, Inc.Plate B-4 Description Sand 106.5 4.9 18.7 Initial Dry Density (pcf)Initial Moisture Content (%)Final Moisture Concent (%) 0 1 2 3 4 5 6 7 8 9 10 11 12 100 1000 10000 100000CONSOLIDATION (%)NORMAL STRESS (psf) Field Saturated ALBUS & ASSOCIATES, INC. APPENDIX C PERCOLATION TESTING AND ANALYSES Client: Job. No.: 3016.00 Date Tested: Test by: ddalbus Location: Top of Casing to Bottom of Well (ft): 15 Elev. of Ground Surface (ft): Diam. of Test Hole (in): 8 Diam. of Casing (in): 3 Ht. to Top of Casing (ft): 0.3 Water Tempurature (C°): 21 Elapsed Time Depth to H2O Flow Rate Total H2O used (minutes) (ft) (gal./min.) (gal) 0 9:35 12.5 6.60 0.00 1 9:36 12.5 6.40 6.50 2 9:37 12.5 6.10 13.00 2 9:37 12.5 5.92 16.12 3 9:38 12.5 5.80 19.13 4 9:39 12.5 5.56 24.99 5 9:40 12.50 5.46 30.67 6 9:41 12.50 5.36 36.18 7 9:42 12.50 5.20 41.59 9 9:44 12.50 5.00 52.15 11 9:46 12.50 4.86 62.35 23 9:58 12.30 4.70 121.51 35 10:10 12.3 4.70 178.87 45 10:20 12.30 4.70 225.87 55 10:30 21.30 4.70 272.87 Constant Head Time Field Percolation Testing - Constant Head 9/7/2021 P-1 Borstein Enterprises 0.00 50.00 100.00 150.00 200.00 250.00 300.00 0 10 20 30 40 50 60Accumulated Flow - Gallons Time - Minutes ALBUS & ASSOCIATES, INC.Plate C-1 Client: Job. No.: 3016.00 Date Tested: Test by: ddalbus Location: Top of Casing to Bottom of Well (ft): 30 Elev. of Ground Surface (ft): 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 12:15 26.95 1.00 0.00 2 12:17 26.95 0.98 1.98 3 12:18 26.85 0.86 2.97 5 12:20 26.8 0.78 4.81 7 12:22 26.8 0.68 6.45 13 12:28 26.8 0.68 10.83 29 12:44 26.80 0.68 21.71 45 13:00 26.80 0.68 32.59 Time Field Percolation Testing - Constant Head Borstein Enterprises 9/7/2021 P-2 Constant Head 0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 0 10 20 30 40 50Accumulated Flow - Gallons Time - Minutes ALBUS & ASSOCIATES, INC.Plate C-2 J.N.:3016.00 Client: Borstein Enterprises Well No.: P-1 Condition 1 Condition 2 Condition 3 Units: 1 14.7 feet 12 feet 2.7 feet 4.0 Inches Minimum Volume Required:361.1 Gal. 4.7 Gal/min. 21 Celsius 0.9647 ft^3/min. Ignore Tᵤ 1 2.55E-02 ft/min. 18.34 in./hr. ALBUS & ASSOCIATES, INC.Plate C-3 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: J.N.:3016.00 Client: Borstein Enterprises Well No.: P-2 Condition 1 Condition 2 Condition 3 Units: 1 30 feet 27 feet 3 feet 4.0 Inches Minimum Volume Required:454.8 Gal. 0.68 Gal/min. 21 Celsius 0.9647 ft^3/min. Ignore Tᵤ 1 3.13E-03 ft/min. 2.26 in./hr. ALBUS & 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: Soil No. 3 - SP/SM Ks = 2 in/hr Soil No. 2 - SW Ks = 15 in/hr Soil No. 4 - SC Ks = 0.01 in/hr Soil No. 1 - FILL (SM) Ks = 0.1 in/hr 0 5 10 15 ALBUS & ASSOCIATES, INC.PLATE C-5 Contours are Pressure Head in Feet. STEADY STATE Arrows indicate direction of flow and relative magnitude of velocity. 93 Ft Radius (ft) 0 102030405060Elevation (ft)30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Soil No. 3 - SP/SM Ks = 2 in/hr Soil No. 2 - SW Ks = 15 in/hr Soil No. 4 - SC Ks = 0.01 in/hr Soil No. 1 - FILL (SM) Ks = 0.1 in/hr 0 5 10 15 ALBUS & ASSOCIATES, INC.PLATE C-6 Contours are Pressure Head in Feet. TRANSIENT @ 0.5 hrs Arrows indicate direction of flow and relative magnitude of velocity. Radius (ft) 0 102030405060Elevation (ft)30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Soil No. 3 - SP/SM Ks = 2 in/hr Soil No. 2 - SW Ks = 15 in/hr Soil No. 4 - SC Ks = 0.01 in/hr Soil No. 1 - FILL (SM) Ks = 0.1 in/hr 0 5 ALBUS & ASSOCIATES, INC.PLATE C-7 Contours are Pressure Head in Feet. TRANSIENT @ 1 hr Arrows indicate direction of flow and relative magnitude of velocity. Radius (ft) 0 102030405060Elevation (ft)30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Soil No. 3 - SP/SM Ks = 2 in/hr Soil No. 2 - SW Ks = 15 in/hr Soil No. 4 - SC Ks = 0.01 in/hr Soil No. 1 - FILL (SM) Ks = 0.1 in/hr 0 ALBUS & ASSOCIATES, INC.PLATE C-8 Contours are Pressure Head in Feet. TRANSIENT @ 1.5 hrs Arrows indicate direction of flow and relative magnitude of velocity. Radius (ft) 0 102030405060Elevation (ft)30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Soil No. 3 - SP/SM Ks = 2 in/hr Soil No. 2 - SW Ks = 15 in/hr Soil No. 4 - SC Ks = 0.01 in/hr Soil No. 1 - FILL (SM) Ks = 0.1 in/hr 0 ALBUS & ASSOCIATES, INC.PLATE C-9 Contours are Pressure Head in Feet. TRANSIENT @ 2.5 hrs Arrows indicate direction of flow and relative magnitude of velocity. Radius (ft) 0 102030405060Elevation (ft)30 35 40 45 50 55 60 65 70 75 80 85 90 95 100