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HomeMy WebLinkAbout10. Preliminary WQMP (1)- 1 - Project Specific Water Quality Management Plan A Template for Projects located within the Santa Ana Watershed Region of Riverside County Project Title: Stockdale Industrial Development No: Design Review/Case No: Original Date Prepared: 07-19-2024 Revision Date(s): Prepared for Compliance with Regional Board Order No. R8-2010-0033 Template revised June 30, 2016 Contact Information: Prepared for: Alberhill Holdings, LLC 505 Lomas Santa Fe Drive, Suite 230 Solana Beach, CA 92075 Andy Petitjean (714) 944-3044 Prepared by: KWC Engineers 1880 Compton Ave., Suite 100 Corona, CA 92881 Brandon Barnett, P.E. (951) 734-2130 Preliminary Final - 2 - A Brief Introduction This Project-Specific WQMP Template for the Santa Ana Region has been prepared to help guide you in documenting compliance for your project. Because this document has been designed to specifically document compliance, you will need to utilize the WQMP Guidance Document as your “how-to” manual to help guide you through this process. Both the Template and Guidance Document go hand-in-hand, and will help facilitate a well prepared Project-Specific WQMP. Below is a flowchart for the layout of this Template that will provide the steps required to document compliance. Section A Project and Site Information Section B Optimize Site Utilization Section C Delineate Drainage Management Areas (DMAs) Section G Source Control BMPs Section I Operation, Maintenance, and Funding Section F Hydromodification Section E Alternative Compliance Section D Implement LID BMPs Section H Construction Plan Checklist - 3 - OWNER’S CERTIFICATION This Project-Specific Water Quality Management Plan (WQMP) has been prepared for Alberhill Holdings, LLC by KWC Engineers for the Stockdale Industrial project. This WQMP is intended to comply with the requirements of City of Lake Elsinore for Ordinance 1296 (Municipal Code 14.08) which includes the requirement for the preparation and implementation of a Project-Specific WQMP. The undersigned, while owning the property/project described in the preceding paragraph, shall be responsible for the implementation and funding of this WQMP and will ensure that this WQMP is amended as appropriate to reflect up-to-date conditions on the site. In addition, the property owner accepts responsibility for interim operation and maintenance of Stormwater BMPs until such time as this responsibility is formally transferred to a subsequent owner. This WQMP will be reviewed with the facility operator, facility supervisors, employees, tenants, maintenance and service contractors, or any other party (or parties) having responsibility for implementing portions of this WQMP. At least one copy of this WQMP will be maintained at the project site or project office in perpetuity. The undersigned is authorized to certify and to approve implementation of this WQMP. The undersigned is aware that implementation of this WQMP is enforceable under City of Lake Elsinore Water Quality Ordinance (Municipal Code Section 14.08). "I, the undersigned, certify under penalty of law that the provisions of this WQMP have been reviewed and accepted and that the WQMP will be transferred to future successors in interest." Owner’s Signature Date Greg Lansing Owner Owner’s Printed Name Owner’s Title/Position PREPARER’S CERTIFICATION “The selection, sizing and design of stormwater treatment and other stormwater quality and quantity control measures in this plan meet the requirements of Regional Water Quality Control Board Order No. R8-2010-0033 and any subsequent amendments thereto.” Preparer’s Signature Date John Snell Project manager Preparer’s Printed Name Preparer’s Title/Position Preparer’s Licensure: - 4 - Table of Contents Section A: Project and Site Information........................................................................................................ 6 A.1 Maps and Site Plans ............................................................................................................................ 6 A.2 Identify Receiving Waters ................................................................................................................... 7 A.3 Additional Permits/Approvals required for the Project: .................................................................... 7 Section B: Optimize Site Utilization (LID Principles) ..................................................................................... 8 Section C: Delineate Drainage Management Areas (DMAs) ....................................................................... 10 Section D: Implement LID BMPs ................................................................................................................. 12 D.1 Infiltration Applicability .................................................................................................................... 12 D.2 Harvest and Use Assessment ............................................................................................................ 13 D.3 Bioretention and Biotreatment Assessment .................................................................................... 15 D.4 Feasibility Assessment Summaries ................................................................................................... 16 D.5 LID BMP Sizing .................................................................................................................................. 17 Section E: Alternative Compliance (LID Waiver Program) .......................................................................... 18 E.1 Identify Pollutants of Concern .......................................................................................................... 19 E.2 Stormwater Credits ........................................................................................................................... 20 E.3 Sizing Criteria ..................................................................................................................................... 20 E.4 Treatment Control BMP Selection .................................................................................................... 21 Section F: Hydromodification ..................................................................................................................... 22 F.1 Hydrologic Conditions of Concern (HCOC) Analysis .......................................................................... 22 F.2 HCOC Mitigation ................................................................................................................................ 23 Section G: Source Control BMPs ................................................................................................................. 24 Section H: Construction Plan Checklist ....................................................................................................... 27 Section I: Operation, Maintenance and Funding ........................................................................................ 28 - 5 - List of Tables Table A.1 Identification of Receiving Waters ................................................................................................ 7 Table A.2 Other Applicable Permits .............................................................................................................. 7 Table C.1 DMA Classifications ..................................................................................................................... 10 Table C.2 Type ‘A’, Self-Treating Areas ....................................................................................................... 10 Table C.3 Type ‘B’, Self-Retaining Areas ..................................................................................................... 10 Table C.4 Type ‘C’, Areas that Drain to Self-Retaining Areas ...................................................................... 11 Table C.5 Type ‘D’, Areas Draining to BMPs ............................................................................................... 11 Table D.1 Infiltration Feasibility .................................................................................................................. 12 Table D.2 LID Prioritization Summary Matrix ............................................................................................. 16 Table D.3 DCV Calculations for LID BMPs ................................................................................................... 17 Table E.1 Potential Pollutants by Land Use Type ........................................................................................ 19 Table E.2 Water Quality Credits .................................................................................................................. 20 Table E.3 Treatment Control BMP Sizing .................................................................................................... 20 Table E.4 Treatment Control BMP Selection .............................................................................................. 21 Table F.1 Hydrologic Conditions of Concern Summary .............................................................................. 22 Table G.1 Permanent and Operational Source Control Measures ............................................................. 24 Table H.1 Construction Plan Cross-reference ............................................................................................. 27 List of Appendices Appendix 1: Maps and Site Plans ................................................................................................................ 29 Appendix 2: Construction Plans .................................................................................................................. 30 Appendix 3: Soils Information ..................................................................................................................... 31 Appendix 4: Historical Site Conditions ........................................................................................................ 32 Appendix 5: LID Infeasibility ........................................................................................................................ 33 Appendix 6: BMP Design Details ................................................................................................................. 34 Appendix 7: Hydromodification .................................................................................................................. 35 Appendix 8: Source Control ........................................................................................................................ 36 Appendix 9: O&M ....................................................................................................................................... 37 Appendix 10: Educational Materials ......................................................................................................... - 6 - - 6 - Section A: Project and Site Information PROJECT INFORMATION Type of Project: Industrial Planning Area: General Manufacturing District Community Name: Alberhill Area Development Name: Stockdale Industrial PROJECT LOCATION Latitude & Longitude (DMS): 33°42'16.4"N, 117°22'08.8"W Project Watershed and Sub-Watershed: Santa Ana River Watershed and Temescal Creek Reach 5 Gross Acres: 55.01 APN(s): Map Book and Page No.: PROJECT CHARACTERISTICS Proposed or Potential Land Use(s) Limited Industrial Proposed or Potential SIC Code(s) Area of Impervious Project Footprint (SF) 1,934,435 Total Area of proposed Impervious Surfaces within the Project Footprint (SF)/or Replacement 1,934,435 Does the project consist of offsite road improvements? Y N Does the project propose to construct unpaved roads? Y N Is the project part of a larger common plan of development (phased project)? Y N EXISTING SITE CHARACTERISTICS Total area of existing Impervious Surfaces within the Project limits Footprint (SF) 0 Is the project located within any MSHCP Criteria Cell? Y N If so, identify the Cell number: 4157 Are there any natural hydrologic features on the project site? Y N Is a Geotechnical Report attached? Y N If no Geotech. Report, list the NRCS soils type(s) present on the site (A, B, C and/or D) What is the Water Quality Design Storm Depth for the project? 0.72 A.1 Maps and Site Plans When completing your Project-Specific WQMP, include a map of the local vicinity and existing site. In addition, include all grading, drainage, landscape/plant palette and other pertinent construction plans in Appendix 2. At a minimum, your WQMP Site Plan should include the following: • Drainage Management Areas • Proposed Structural BMPs • Drainage Path • Drainage Infrastructure, Inlets, Overflows • Source Control BMPs • Buildings, Roof Lines, Downspouts • Impervious Surfaces • Standard Labeling • BMP Locations (Lat/Long) Use your discretion on whether or not you may need to create multiple sheets or can appropriately accommodate these features on one or two sheets. Keep in mind that the Co-Permittee plan reviewer must be able to easily analyze your project utilizing this template and its associated site plans and maps. - 7 - A.2 Identify Receiving Waters Using Table A.1 below, list in order of upstream to downstream, the receiving waters that the project site is tributary to. Continue to fill each row with the Receiving Water’s 303(d) listed impairments (if any), designated beneficial uses, and proximity, if any, to a RARE beneficial use. Include a map of the receiving waters in Appendix 1. Table A.1 Identification of Receiving Waters Receiving Waters EPA Approved 303(d) List Impairments Designated Beneficial Uses Proximity to RARE Beneficial Use Temescal Creek Channel Reaches 5-6 Indicator Bacteria MUN, AGR, GWR, REC1, REC2, WARM, WILD, RARE N/A lake elsinore Nutrients, Orgqanic Enrichment/Low Dissolved Oxygen, PCBs, Sediment Toxicity, Unknown Toxicity AGR, GWR, REC1, REC2, WARM, WILD N/A A.3 Additional Permits/Approvals required for the Project: Table A.2 Other Applicable Permits Agency Permit Required State Department of Fish and Game, 1602 Streambed Alteration Agreement Y N State Water Resources Control Board, Clean Water Act (CWA) Section 401 Water Quality Cert. Y N US Army Corps of Engineers, CWA Section 404 Permit Y N US Fish and Wildlife, Endangered Species Act Section 7 Biological Opinion Y N Statewide Construction General Permit Coverage Y N Statewide Industrial General Permit Coverage Y N Western Riverside MSHCP Consistency Approval (e.g., JPR, DBESP) Y N Other (please list in the space below as required) City of Lake Elsinore Grading, Improvements, and Building Permits. Y N If yes is answered to any of the questions above, the Co-Permittee may require proof of approval/coverage from those agencies as applicable including documentation of any associated requirements that may affect this Project-Specific WQMP. - 8 - Section B: Optimize Site Utilization (LID Principles) Review of the information collected in Section ‘A’ will aid in identifying the principal constraints on site design and selection of LID BMPs as well as opportunities to reduce imperviousness and incorporate LID Principles into the site and landscape design. For example, constraints might include impermeable soils, high groundwater, groundwater pollution or contaminated soils, steep slopes, geotechnical instability, high-intensity land use, heavy pedestrian or vehicular traffic, utility locations or safety concerns. Opportunities might include existing natural areas, low areas, oddly configured or otherwise unbuildable parcels, easements and landscape amenities including open space and buffers (which can double as locations for bioretention BMPs), and differences in elevation (which can provide hydraulic head). Prepare a brief narrative for each of the site optimization strategies described below. This narrative will help you as you proceed with your LID design and explain your design decisions to others. The 2010 Santa Ana MS4 Permit further requires that LID Retention BMPs (Infiltration Only or Harvest and Use) be used unless it can be shown that those BMPs are infeasible. Therefore, it is important that your narrative identify and justify if there are any constraints that would prevent the use of those categories of LID BMPs. Similarly, you should also note opportunities that exist which will be utilized during project design. Upon completion of identifying Constraints and Opportunities, include these on your WQMP Site plan in Appendix 1. Consideration of “highest and best use” of the discharge should also be considered. For example, Lake Elsinore is evaporating faster than runoff from natural precipitation can recharge it. Requiring infiltration of 85% of runoff events for projects tributary to Lake Elsinore would only exacerbate current water quality problems associated with Pollutant concentration due to lake water evaporation. In cases where rainfall events have low potential to recharge Lake Elsinore (i.e. no hydraulic connection between groundwater to Lake Elsinore, or other factors), requiring infiltration of Urban Runoff from projects is counterproductive to the overall watershed goals. Project proponents, in these cases, would be allowed to discharge Urban Runoff, provided they used equally effective filtration-based BMPs. Site Optimization The following questions are based upon Section 3.2 of the WQMP Guidance Document. Review of the WQMP Guidance Document will help you determine how best to optimize your site and subsequently identify opportunities and/or constraints, and document compliance. Did you identify and preserve existing drainage patterns? If so, how? If not, why? Yes. Pre-project site drains north-easterly into Temescal Creek. There will be no impact to Temescal Creek in the proposed conditions, as the site will detained, treated, and outletted at locations similar to existing condition flows. Did you identify and protect existing vegetation? If so, how? If not, why? Yes. Some existing vegetation will be preserved during site improvements in the natural open space areas. Did you identify and preserve natural infiltration capacity? If so, how? If not, why? Yes. The natural open space areas will preserve their natural infiltration by not disturbing the existing drainage patterns. - 9 - Did you identify and minimize impervious area? If so, how? If not, why? The proposed impervious areas incorporate landscaped areas within the site to increase infiltration. Did you identify and disperse runoff to adjacent pervious areas? If so, how? If not, why? Yes, roof runoff has been designed to drain into pervious landscape areas prior to discharge onto streets. - 10 - Section C: Delineate Drainage Management Areas (DMAs) Utilizing the procedure in Section 3.3 of the WQMP Guidance Document which discusses the methods of delineating and mapping your project site into individual DMAs, complete Table C.1 below to appropriately categorize the types of classification (e.g., Type A, Type B, etc.) per DMA for your project site. Upon completion of this table, this information will then be used to populate and tabulate the corresponding tables for their respective DMA classifications. Table C.1 DMA Classifications DMA Name or ID Surface Type(s)12 Area (Sq. Ft.) DMA Type DMA A Roofs 78,423 Type D Asphalt/Concrete 95,647 Landscape 162,735 DMA B Roofs 964,947 Type D Asphalt/Concrete 795,418 Landscape 298,772 1Reference Table 2-1 in the WQMP Guidance Document to populate this column 2If multi-surface provide back-up Table C.2 Type ‘A’, Self-Treating Areas DMA Name or ID Area (Sq. Ft.) Stabilization Type Irrigation Type (if any) Table C.3 Type ‘B’, Self-Retaining Areas Self-Retaining Area Type ‘C’ DMAs that are draining to the Self-Retaining Area DMA Name/ ID Post-project surface type Area (square feet) Storm Depth (inches) DMA Name / ID [C] from Table C.4 = Required Retention Depth (inches) [A] [B] [C] [D] [𝐷𝐷]=[𝐵𝐵]+[𝐵𝐵]∙[𝐶𝐶][𝐴𝐴] - 11 - Table C.4 Type ‘C’, Areas that Drain to Self-Retaining Areas DMA Receiving Self-Retaining DMA DMA Name/ ID Area (square feet) Post-project surface type Impervious fraction Product DMA name /ID Area (square feet) Ratio [A] [B] [C] = [A] x [B] [D] [C]/[D] Table C.5 Type ‘D’, Areas Draining to BMPs DMA Name or ID BMP Name or ID DMA A Bioretention Basin DMA B Bioretention Basin Note: More than one drainage management area can drain to a single LID BMP, however, one drainage management area may not drain to more than one BMP. - 12 - Section D: Implement LID BMPs D.1 Infiltration Applicability Is there an approved downstream ‘Highest and Best Use’ for stormwater runoff (see discussion in Chapter 2.4.4 of the WQMP Guidance Document for further details)? Y N If yes has been checked, Infiltration BMPs shall not be used for the site; proceed to section D.3 If no, continue working through this section to implement your LID BMPs. It is recommended that you contact your Co-Permittee to verify whether or not your project discharges to an approved downstream ‘Highest and Best Use’ feature. Geotechnical Report A Geotechnical Report or Phase I Environmental Site Assessment may be required by the Copermittee to confirm present and past site characteristics that may affect the use of Infiltration BMPs. In addition, the Co-Permittee, at their discretion, may not require a geotechnical report for small projects as described in Chapter 2 of the WQMP Guidance Document. If a geotechnical report has been prepared, include it in Appendix 3. In addition, if a Phase I Environmental Site Assessment has been prepared, include it in Appendix 4. Is this project classified as a small project consistent with the requirements of Chapter 2 of the WQMP Guidance Document? Y N Infiltration Feasibility Table D.1 below is meant to provide a simple means of assessing which DMAs on your site support Infiltration BMPs and is discussed in the WQMP Guidance Document in Chapter 2.4.5. Check the appropriate box for each question and then list affected DMAs as applicable. If additional space is needed, add a row below the corresponding answer. Table D.1 Infiltration Feasibility Does the project site… YES NO …have any DMAs with a seasonal high groundwater mark shallower than 10 feet? X If Yes, list affected DMAs: …have any DMAs located within 100 feet of a water supply well? X If Yes, list affected DMAs: …have any areas identified by the geotechnical report as posing a public safety risk where infiltration of stormwater could have a negative impact? X If Yes, list affected DMAs: …have measured in-situ infiltration rates of less than 1.6 inches / hour? X If Yes, list affected DMAs: DMA A and DMA B …have significant cut and/or fill conditions that would preclude in-situ testing of infiltration rates at the final infiltration surface? X If Yes, list affected DMAs: DMA A and DMA B …geotechnical report identify other site-specific factors that would preclude effective and safe infiltration? X Describe here: Liquefaction, Landslides, and Secondary Seismic Effects If you answered “Yes” to any of the questions above for any DMA, Infiltration BMPs should not be used for those DMAs and you should proceed to the assessment for Harvest and Use below. - 13 - D.2 Harvest and Use Assessment Please check what applies: ☐ Reclaimed water will be used for the non-potable water demands for the project. ☐Downstream water rights may be impacted by Harvest and Use as approved by the Regional Board (verify with the Copermittee). ☐The Design Capture Volume will be addressed using Infiltration Only BMPs. In such a case, Harvest and Use BMPs are still encouraged, but it would not be required if the Design Capture Volume will be infiltrated or evapotranspired. If any of the above boxes have been checked, Harvest and Use BMPs need not be assessed for the site. If none of the above criteria applies, follow the steps below to assess the feasibility of irrigation use, toilet use and other non-potable uses (e.g., industrial use). Irrigation Use Feasibility Complete the following steps to determine the feasibility of harvesting stormwater runoff for Irrigation Use BMPs on your site: Step 1: Identify the total area of irrigated landscape on the site, and the type of landscaping used. Total Area of Irrigated Landscape: 10.59 AC Type of Landscaping (Conservation Design or Active Turf): Conservation Design Step 2: Identify the planned total of all impervious areas on the proposed project from which runoff might be feasibly captured and stored for irrigation use. Depending on the configuration of buildings and other impervious areas on the site, you may consider the site as a whole, or parts of the site, to evaluate reasonable scenarios for capturing and storing runoff and directing the stored runoff to the potential use(s) identified in Step 1 above. Total Area of Impervious Surfaces: 44.41 AC Step 3: Cross reference the Design Storm depth for the project site (see Exhibit A of the WQMP Guidance Document) with the left column of Table 2-3 in Chapter 2 to determine the minimum area of Effective Irrigated Area per Tributary Impervious Area (EIATIA). Enter your EIATIA factor: 1.32 Step 4: Multiply the unit value obtained from Step 3 by the total of impervious areas from Step 2 to develop the minimum irrigated area that would be required. Minimum required irrigated area: 58.62 AC Step 5: Determine if harvesting stormwater runoff for irrigation use is feasible for the project by comparing the total area of irrigated landscape (Step 1) to the minimum required irrigated area (Step 4). Minimum required irrigated area (Step 4) Available Irrigated Landscape (Step 1) 58.62 AC 10.59 AC - 14 - Toilet Use Feasibility Complete the following steps to determine the feasibility of harvesting stormwater runoff for toilet flushing uses on your site: Step 1: Identify the projected total number of daily toilet users during the wet season, and account for any periodic shut downs or other lapses in occupancy: Projected Number of Daily Toilet Users: 150 Project Type: Industrial Step 2: Identify the planned total of all impervious areas on the proposed project from which runoff might be feasibly captured and stored for toilet use. Depending on the configuration of buildings and other impervious areas on the site, you may consider the site as a whole, or parts of the site, to evaluate reasonable scenarios for capturing and storing runoff and directing the stored runoff to the potential use(s) identified in Step 1 above. Total Area of Impervious Surfaces: 44.41 AC Step 3: Enter the Design Storm depth for the project site (see Exhibit A) into the left column of Table 2-2 in Chapter 2 to determine the minimum number or toilet users per tributary impervious acre (TUTIA). Enter your TUTIA factor: 198 Step 4: Multiply the unit value obtained from Step 3 by the total of impervious areas from Step 2 to develop the minimum number of toilet users that would be required. Minimum number of toilet users: 8,794 Step 5: Determine if harvesting stormwater runoff for toilet flushing use is feasible for the project by comparing the Number of Daily Toilet Users (Step 1) to the minimum required number of toilet users (Step 4). Minimum required Toilet Users (Step 4) Projected number of toilet users (Step 1) 8,794 150 Other Non-Potable Use Feasibility Are there other non-potable uses for stormwater runoff on the site (e.g. industrial use)? See Chapter 2 of the Guidance for further information. If yes, describe below. If no, write N/A. N/A Step 1: Identify the projected average daily non-potable demand, in gallons per day, during the wet season and accounting for any periodic shut downs or other lapses in occupancy or operation. Average Daily Demand: Step 2: Identify the planned total of all impervious areas on the proposed project from which runoff might be feasibly captured and stored for the identified non-potable use. Depending on the configuration of buildings and other impervious areas on the site, you may consider the site as a whole, or parts of the site, to evaluate reasonable scenarios for capturing and storing runoff and directing the stored runoff to the potential use(s) identified in Step 1 above. Total Area of Impervious Surfaces: - 15 - Step 3: Enter the Design Storm depth for the project site (see Exhibit A) into the left column of Table 2-4 in Chapter 2 to determine the minimum demand for non-potable uses per tributary impervious acre. Enter the factor from Table 2-4: Step 4: Multiply the unit value obtained from Step 3 by the total of impervious areas from Step 2 to develop the minimum number of gallons per day of non-potable use that would be required. Minimum required use: Step 5: Determine if harvesting stormwater runoff for other non-potable use is feasible for the project by comparing the projected average daily use (Step 1) to the minimum required non-potable use (Step 4). Minimum required non-potable use (Step 4) Projected average daily use (Step 1) If Irrigation, Toilet and Other Use feasibility anticipated demands are less than the applicable minimum values, Harvest and Use BMPs are not required and you should proceed to utilize LID Bioretention and Biotreatment per Section 3.4.2 of the WQMP Guidance Document. D.3 Bioretention and Biotreatment Assessment Other LID Bioretention and Biotreatment BMPs as described in Chapter 2.4.7 of the WQMP Guidance Document are feasible on nearly all development sites with sufficient advance planning. Select one of the following: ☒ LID Bioretention/Biotreatment BMPs will be used for some or all DMAs of the project as noted below in Section D.4 (note the requirements of Section 3.4.2 in the WQMP Guidance Document). ☐ A site-specific analysis demonstrating the technical infeasibility of all LID BMPs has been performed and is included in Appendix 5. If you plan to submit an analysis demonstrating the technical infeasibility of LID BMPs, request a pre-submittal meeting with the Copermittee to discuss this option. Proceed to Section E to document your alternative compliance measures. - 16 - D.4 Feasibility Assessment Summaries From the Infiltration, Harvest and Use, Bioretention and Biotreatment Sections above, complete Table D.2 below to summarize which LID BMPs are technically feasible, and which are not, based upon the established hierarchy. Table D.2 LID Prioritization Summary Matrix DMA Name/ID LID BMP Hierarchy No LID (Alternative Compliance) 1. Infiltration 2. Harvest and use 3. Bioretention 4. Biotreatment DMA A DMA B For those DMAs where LID BMPs are not feasible, provide a brief narrative below summarizing why they are not feasible, include your technical infeasibility criteria in Appendix 5, and proceed to Section E below to document Alternative Compliance measures for those DMAs. Recall that each proposed DMA must pass through the LID BMP hierarchy before alternative compliance measures may be considered. No alternative compliance measures were studied or used for this project. - 17 - D.5 LID BMP Sizing Each LID BMP must be designed to ensure that the Design Capture Volume will be addressed by the selected BMPs. First, calculate the Design Capture Volume for each LID BMP using the VBMP worksheet in Appendix F of the LID BMP Design Handbook. Second, design the LID BMP to meet the required VBMP using a method approved by the Copermittee. Utilize the worksheets found in the LID BMP Design Handbook or consult with your Copermittee to assist you in correctly sizing your LID BMPs. Complete Table D.3 below to document the Design Capture Volume and the Proposed Volume for each LID BMP. Provide the completed design procedure sheets for each LID BMP in Appendix 6. You may add additional rows to the table below as needed. Table D.3 DCV Calculations for LID BMPs DMA Type/ID DMA Area (square feet) Post-Project Surface Type Effective Impervious Fraction, If DMA Runoff Factor DMA Areas x Runoff Factor Bioretention Basin A DMA A [A] [B] [C] [A] x [C] Roofs 78,423 Roofs 1 0.89 69,953.3 Design Rainfall Intensity (in/hr) Design Capture Volume, VBMP (cubic feet) Proposed Volume (cubic feet) Concrete 95,647 Concrete or Asphalt 1 0.892 85,317.1 Landscape 162,735 Ornamental Landscaping 0.1 0.1104558 17,975.4 AT= 336,805 Σ= 173,245.8 0.72 10,394.7 12,243 Table D.4 DCV Calculations for LID BMPs DMA Type/ID DMA Area (square feet) Post-Project Surface Type Effective Impervious Fraction, If DMA Runoff Factor DMA Areas x Runoff Factor Bioretention Basin B DMA B [A] [B] [C] [A] x [C] Roofs 964,947 Roofs 1 0.89 860,732.7 Design Rainfall Intensity (in/hr) Design Capture Volume, VBMP (cubic feet) Proposed Volume (cubic feet) Concrete 795,418 Concrete or Asphalt 1 0.892 709,512.9 Landscape 298,772 Ornamental Landscaping 0.1 0.1104558 33,001.8 AT= 2,059,137 Σ= 1,603,247.4 0.72 96,194.8 101,170 [B], [C] is obtained as described in Section 2.3.1 of the WQMP Guidance Document [E] is obtained from Exhibit A in the WQMP Guidance Document [G] is obtained from a design procedure sheet, such as in LID BMP Design Handbook and placed in Appendix 6 - 18 - Section E: Alternative Compliance (LID Waiver Program) LID BMPs are expected to be feasible on virtually all projects. Where LID BMPs have been demonstrated to be infeasible as documented in Section D, other Treatment Control BMPs must be used (subject to LID waiver approval by the Copermittee). Check one of the following Boxes: ☒ LID Principles and LID BMPs have been incorporated into the site design to fully address all Drainage Management Areas. No alternative compliance measures are required for this project and thus this Section is not required to be completed. - Or - ☐ The following Drainage Management Areas are unable to be addressed using LID BMPs. A site-specific analysis demonstrating technical infeasibility of LID BMPs has been approved by the Co-Permittee and included in Appendix 5. Additionally, no downstream regional and/or sub- regional LID BMPs exist or are available for use by the project. The following alternative compliance measures on the following pages are being implemented to ensure that any pollutant loads expected to be discharged by not incorporating LID BMPs, are fully mitigated. - 19 - E.1 Identify Pollutants of Concern Utilizing Table A.1 from Section A above which noted your project’s receiving waters and their associated EPA approved 303(d) listed impairments, cross reference this information with that of your selected Priority Development Project Category in Table E.1 below. If the identified General Pollutant Categories are the same as those listed for your receiving waters, then these will be your Pollutants of Concern and the appropriate box or boxes will be checked on the last row. The purpose of this is to document compliance and to help you appropriately plan for mitigating your Pollutants of Concern in lieu of implementing LID BMPs. Table E.1 Potential Pollutants by Land Use Type Priority Development Project Categories and/or Project Features (check those that apply) General Pollutant Categories Bacterial Indicators Metals Nutrients Pesticides Toxic Organic Compounds Sediments Trash & Debris Oil & Grease Detached Residential Development P N P P N P P P Attached Residential Development P N P P N P P P(2) Commercial/Industrial Development P(3) P P(1) P(1) P(5) P(1) P P Automotive Repair Shops N P N N P(4, 5) N P P Restaurants (>5,000 ft2) P N N N N N P P Hillside Development (>5,000 ft2) P N P P N P P P Parking Lots (>5,000 ft2) P(6) P P(1) P(1) P(4) P(1) P P Retail Gasoline Outlets N P N N P N P P Project Priority Pollutant(s) of Concern P = Potential N = Not Potential (1) A potential Pollutant if non-native landscaping exists or is proposed onsite; otherwise not expected (2) A potential Pollutant if the project includes uncovered parking areas; otherwise not expected (3) A potential Pollutant is land use involving animal waste (4) Specifically petroleum hydrocarbons (5) Specifically solvents (6) Bacterial indicators are routinely detected in pavement runoff - 20 - E.2 Stormwater Credits Projects that cannot implement LID BMPs but nevertheless implement smart growth principles are potentially eligible for Stormwater Credits. Utilize Table 3-8 within the WQMP Guidance Document to identify your Project Category and its associated Water Quality Credit. If not applicable, write N/A. Table E.2 Water Quality Credits Qualifying Project Categories Credit Percentage2 N/A Total Credit Percentage1 1Cannot Exceed 50% 2Obtain corresponding data from Table 3-8 in the WQMP Guidance Document E.3 Sizing Criteria After you appropriately considered Stormwater Credits for your project, utilize Table E.3 below to appropriately size them to the DCV, or Design Flow Rate, as applicable. Please reference Chapter 3.5.2 of the WQMP Guidance Document for further information. Table E.3 Treatment Control BMP Sizing DMA Type/ID DMA Area (square feet) Post- Project Surface Type Effective Impervious Fraction, If DMA Runoff Factor DMA Area x Runoff Factor Enter BMP Name / Identifier Here [A] [B] [C] [A] x [C] Design Storm Depth (in) Minimum Design Capture Volume or Design Flow Rate (cubic feet or cfs) Total Storm Water Credit % Reduction Proposed Volume or Flow on Plans (cubic feet or cfs) AT = Σ[A] Σ= [D] [E] [F] = [D]x[E] [G] [F] X (1-[H]) [I] [B], [C] is obtained as described in Section 2.3.1 from the WQMP Guidance Document [E] is for Flow-Based Treatment Control BMPs [E] = .2, for Volume-Based Control Treatment BMPs, [E] obtained from Exhibit A in the WQMP Guidance Document [G] is for Flow-Based Treatment Control BMPs [G] = 43,560, for Volume-Based Control Treatment BMPs, [G] = 12 [H] is from the Total Credit Percentage as Calculated from Table E.2 above [I] as obtained from a design procedure sheet from the BMP manufacturer and should be included in Appendix 6 - 21 - E.4 Treatment Control BMP Selection Treatment Control BMPs typically provide proprietary treatment mechanisms to treat potential pollutants in runoff, but do not sustain significant biological processes. Treatment Control BMPs must have a removal efficiency of a medium or high effectiveness as quantified below: • High: equal to or greater than 80% removal efficiency • Medium: between 40% and 80% removal efficiency Such removal efficiency documentation (e.g., studies, reports, etc.) as further discussed in Chapter 3.5.2 of the WQMP Guidance Document, must be included in Appendix 6. In addition, ensure that proposed Treatment Control BMPs are properly identified on the WQMP Site Plan in Appendix 1. Table E.4 Treatment Control BMP Selection Selected Treatment Control BMP Name or ID1 Priority Pollutant(s) of Concern to Mitigate2 Removal Efficiency Percentage3 Bioretention Basin Metals, nutrients, pesticides, toxic organic compounds, sediments, trash & debris, oil & grease Medium 1 Treatment Control BMPs must not be constructed within Receiving Waters. In addition, a proposed Treatment Control BMP may be listed more than once if they possess more than one qualifying pollutant removal efficiency. 2 Cross Reference Table E.1 above to populate this column. 3 As documented in a Co-Permittee Approved Study and provided in Appendix 6. - 22 - Section F: Hydromodification F.1 Hydrologic Conditions of Concern (HCOC) Analysis Once you have determined that the LID design is adequate to address water quality requirements, you will need to assess if the proposed LID Design may still create a HCOC. Review Chapters 2 and 3 (including Figure 3-7) of the WQMP Guidance Document to determine if your project must mitigate for Hydromodification impacts. If your project meets one of the following criteria which will be indicated by the check boxes below, you do not need to address Hydromodification at this time. However, if the project does not qualify for Exemptions 1, 2 or 3, then additional measures must be added to the design to comply with HCOC criteria. This is discussed in further detail below in Section F.2. HCOC EXEMPTION 1: The Priority Development Project disturbs less than one acre. The Copermittee has the discretion to require a Project-Specific WQMP to address HCOCs on projects less than one acre on a case by case basis. The disturbed area calculation should include all disturbances associated with larger common plans of development. Does the project qualify for this HCOC Exemption? Y N If Yes, HCOC criteria do not apply. HCOC EXEMPTION 2: The volume and time of concentration1 of storm water runoff for the post- development condition is not significantly different from the pre-development condition for a 2-year return frequency storm (a difference of 5% or less is considered insignificant) using one of the following methods to calculate: • Riverside County Hydrology Manual • Technical Release 55 (TR-55): Urban Hydrology for Small Watersheds (NRCS 1986), or derivatives thereof, such as the Santa Barbara Urban Hydrograph Method • Other methods acceptable to the Co-Permittee Does the project qualify for this HCOC Exemption? Y N If Yes, report results in Table F.1 below and provide your substantiated hydrologic analysis in Appendix 7. Table F.1 Hydrologic Conditions of Concern Summary 2 year – 24 hour Pre-condition Post-condition % Difference Time of Concentration Volume (Cubic Feet) 1 Time of concentration is defined as the time after the beginning of the rainfall when all portions of the drainage basin are contributing to flow at the outlet. - 23 - HCOC EXEMPTION 3: All downstream conveyance channels to an adequate sump (for example, Prado Dam, Lake Elsinore, Canyon Lake, Santa Ana River, or other lake, reservoir or naturally erosion resistant feature) that will receive runoff from the project are engineered and regularly maintained to ensure design flow capacity; no sensitive stream habitat areas will be adversely affected; or are not identified on the Co-Permittees Hydromodification Susceptibility Maps. Does the project qualify for this HCOC Exemption? Y N If Yes, HCOC criteria do not apply and note below which adequate sump applies to this HCOC qualifier: F.2 HCOC Mitigation If none of the above HCOC Exemption Criteria are applicable, HCOC criteria is considered mitigated if they meet one of the following conditions: a. Additional LID BMPS are implemented onsite or offsite to mitigate potential erosion or habitat impacts as a result of HCOCs. This can be conducted by an evaluation of site-specific conditions utilizing accepted professional methodologies published by entities such as the California Stormwater Quality Association (CASQA), the Southern California Coastal Water Research Project (SCCRWP), or other Co-Permittee approved methodologies for site-specific HCOC analysis. b. The project is developed consistent with an approved Watershed Action Plan that addresses HCOC in Receiving Waters. c. Mimicking the pre-development hydrograph with the post-development hydrograph, for a 2- year return frequency storm. Generally, the hydrologic conditions of concern are not significant, if the post-development hydrograph is no more than 10% greater than pre-development hydrograph. In cases where excess volume cannot be infiltrated or captured and reused, discharge from the site must be limited to a flow rate no greater than 110% of the pre- development 2-year peak flow. Be sure to include all pertinent documentation used in your analysis of the items a, b or c in Appendix 7. - 24 - Section G: Source Control BMPs Source control BMPs include permanent, structural features that may be required in your project plans — such as roofs over and berms around trash and recycling areas — and Operational BMPs, such as regular sweeping and “housekeeping”, that must be implemented by the site’s occupant or user. The MEP standard typically requires both types of BMPs. In general, Operational BMPs cannot be substituted for a feasible and effective permanent BMP. Using the Pollutant Sources/Source Control Checklist in Appendix 8, review the following procedure to specify Source Control BMPs for your site: 1. Identify Pollutant Sources: Review Column 1 in the Pollutant Sources/Source Control Checklist. Check off the potential sources of Pollutants that apply to your site. 2. Note Locations on Project-Specific WQMP Exhibit: Note the corresponding requirements listed in Column 2 of the Pollutant Sources/Source Control Checklist. Show the location of each Pollutant source and each permanent Source Control BMP in your Project-Specific WQMP Exhibit located in Appendix 1. 3. Prepare a Table and Narrative: Check off the corresponding requirements listed in Column 3 in the Pollutant Sources/Source Control Checklist. In the left column of Table G.1 below, list each potential source of runoff Pollutants on your site (from those that you checked in the Pollutant Sources/Source Control Checklist). In the middle column, list the corresponding permanent, Structural Source Control BMPs (from Columns 2 and 3 of the Pollutant Sources/Source Control Checklist) used to prevent Pollutants from entering runoff. Add additional narrative in this column that explains any special features, materials or methods of construction that will be used to implement these permanent, Structural Source Control BMPs. 4. Identify Operational Source Control BMPs: To complete your table, refer once again to the Pollutant Sources/Source Control Checklist. List in the right column of your table the Operational BMPs that should be implemented as long as the anticipated activities continue at the site. Copermittee stormwater ordinances require that applicable Source Control BMPs be implemented; the same BMPs may also be required as a condition of a use permit or other revocable Discretionary Approval for use of the site. Table G.1 Permanent and Operational Source Control Measures Potential Sources of Runoff pollutants Permanent Structural Source Control BMPs Operational Source Control BMPs On-site Storm Drain Inlets • Mark all inlets with the words “Only Rain Down the Storm Drain” or similar. Catch Basin Markers shall be per local agency requirements • Maintain and periodically repaint or replace inlet markings. • Provide Stormwater pollution prevention informations to new site owners, lessees, or operators. • See applicable operational BMPs in Fact Sheet SC-44, “Drainage System Maintenance,” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.com - 25 - • Include the following in lease agreements: “Tenant shall not allow anyone to discharge anything to storm drains or to store or deposit materials so as to create a potential discharge to storm drains.” Landscape/ Outdoor Pesticide Use Final landscape plans will accomplish all of the following: • Preserve existing native trees, shrubs, and ground cover to the maximum extent possible. • Design landscaping to minimize irrigation and runoff, to promote surface infiltration where appropriate, and to minimize the use of fertilizers and pesticides that can contribute to stormwater pollution. • Where landscaped areas are used to retain or detain stormwater, specify plants that are tolerant of saturated soil conditions. • Consider using pest-resistant plants, especially adjacent to hardscape. • To insure successful establishment, select plants appropriate to site soils, slopes, climate, sun, wind, rain, land use, air movement, ecological consistency, and plant interactions. • Maintain landscaping using minimum or no pesticides. • See applicable operational BMPs in “What you should know for…..landscape and Gardening” at http://rcflood.org/stormwater/ • Provide IPM information to new owners, lessees and operators. Loading Docks • Move loaded and unloaded items indoors as soon as possible • See Fact Sheet SC-30, “Outdoor Loading and Unloading,” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.co m - 26 - Fire Sprinkler Test Water • Provide a means to drain fire sprinkler water to the sanitary sewer. • See the note in Fact Sheets SC-41, “Building and Grounds Maintenance,” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.co m Miscellaneous Drain or Wash Water of Other Sources Roofing, gutters, and trim • Avoid roofing, gutters, and trim made of copper or other unprotected metals that may leach into runoff Plazas, sidewalks, and parking lots • Sweep plazas, sidewalks, and parking lots regularly to prevent accumulation of litter and debris. Refuse areas • Site refuse will be handled through dumpsters located around the project that will be covered, graded, and paved to prevent run on • Signs will be posted on or near dumpsters with the words “do not dump hazardous materials here” or similar. • Provide adequate number of receptacles. Inspect receptacles regularly; repair or replace leaky receptacles. Keep receptacles covered. Prohibit/prevent dumping of liquid or hazardous wastes. Post “no hazardous materials” signs. Inspect and pick up litter daily and clean up spills immediately. Keep spill control materials available on-site. See Fact Sheet SC-34, “Waste Handling and Disposal” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.co m Industrial processes • All process activities to be performed indoors. No processes to drain to exterior or to storm drain system. • See Fact Sheet SC-10, “Non- Stormwater Discharges” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.co m - 27 - Section H: Construction Plan Checklist Populate Table H.1 below to assist the plan checker in an expeditious review of your project. The first two columns will contain information that was prepared in previous steps, while the last column will be populated with the corresponding plan sheets. This table is to be completed with the submittal of your final Project-Specific WQMP. Table H.1 Construction Plan Cross-reference BMP No. or ID BMP Identifier and Description Corresponding Plan Sheet(s) BMP Location (Lat/Long) DMA A Bioretention Basin Conceptual Grading Plan 33°42'17.5"N 117°22'25.9"W DMA B Bioretention Basin Conceptual Grading Plan 33°42'14.8"N 117°22'00.5"W Note that the updated table — or Construction Plan WQMP Checklist — is only a reference tool to facilitate an easy comparison of the construction plans to your Project-Specific WQMP. Co-Permittee staff can advise you regarding the process required to propose changes to the approved Project-Specific WQMP. - 28 - Section I: Operation, Maintenance and Funding The Copermittee will periodically verify that Stormwater BMPs on your site are maintained and continue to operate as designed. To make this possible, your Copermittee will require that you include in Appendix 9 of this Project-Specific WQMP: 1. A means to finance and implement facility maintenance in perpetuity, including replacement cost. 2. Acceptance of responsibility for maintenance from the time the BMPs are constructed until responsibility for operation and maintenance is legally transferred. A warranty covering a period following construction may also be required. 3. An outline of general maintenance requirements for the Stormwater BMPs you have selected. 4. Figures delineating and designating pervious and impervious areas, location, and type of Stormwater BMP, and tables of pervious and impervious areas served by each facility. Geo- locating the BMPs using a coordinate system of latitude and longitude is recommended to help facilitate a future statewide database system. 5. A separate list and location of self-retaining areas or areas addressed by LID Principles that do not require specialized O&M or inspections but will require typical landscape maintenance as noted in Chapter 5, pages 85-86, in the WQMP Guidance. Include a brief description of typical landscape maintenance for these areas. Your local Co-Permittee will also require that you prepare and submit a detailed Stormwater BMP Operation and Maintenance Plan that sets forth a maintenance schedule for each of the Stormwater BMPs built on your site. An agreement assigning responsibility for maintenance and providing for inspections and certification may also be required. Details of these requirements and instructions for preparing a Stormwater BMP Operation and Maintenance Plan are in Chapter 5 of the WQMP Guidance Document. Maintenance Mechanism: POA Will the proposed BMPs be maintained by a Home Owners’ Association (HOA) or Property Owners Association (POA)? Y N Include your Operation and Maintenance Plan and Maintenance Mechanism in Appendix 9. Additionally, include all pertinent forms of educational materials for those personnel that will be maintaining the proposed BMPs within this Project-Specific WQMP in Appendix 10. - 29 - Appendix 1: Maps and Site Plans Location Map, WQMP Site Plan and Receiving Waters Map Service Layer Credits: Sources: Esri, HERE,Garmin, Intermap, increment P Corp.,GEBCO, USGS, FAO, NPS, NRCAN,GeoBase, IGN, Kadaster NL, OrdnanceSurvey, Esri Japan, METI, Esri China (HongKong), (c) OpenStreetMap contributors, andthe GIS User Community RIVERSIDE COUNTY ORANGE COUNTY |ÿ74 |ÿ74 §¨¦51 §¨¦51 |ÿ74 §¨¦215 §¨¦215 The graphical and tabular information shown on this document may be derived from a variety of public agency and/or private commercial sources such as Riverside County Transportation and Land Management Agency, Thomas Brothers Mapping, the Stephen P. Teale Data Center, GIS Technology Center, State of California, the United States Geologic Survey and the United States National Atlas. These sources may possess varying levels of accuracy and precision and this product is meant only as a guide to the relative position and scale of the depicted features. This GIS document is in no case to be interpreted as fundamental or decisive for purposes of land surveying, field engineering, plan drafting, code enforcement, land boundary determinatio n and/or land acquisition. SEE FOOTNOTE 1 SEE FOOTNOTE 1GARRETSON AVENUESTORM DRAINELCERRITOCHANNELHORSETHIEFCANYONSTORMDRAINFOURCORNERSSTORMDRAIN WESTELSINOREMDP-LINESCANDC1 PERRIS VALLEYMASTER DRAINAGE PLAN -LINE J-1PERRI SVALLEYCHANNELPERRIS VALLEY MDP - LINE A-N-1 PERRIS VALLEY MASTER DRAINAGE PLAN - LINE S FOOTNOTE:1) MS4 PERMIT AREA REMOVED FROM REGION 8 BASED ON JURISDICTIONAL AREA SWAP AGREEMENT BETWEEN REGION 8 AND REGION 9 SAR 2019 AnnRpt - MS4 Maps_Map2.mxdSA-1 SA-4 SA-2 SA-3 SA-5ORANGECOUNTY SAN BERNARDINOCOUNTY SAN DIEGOCOUNTY UPDATED OCTOBER 2019 0 0.5 1 1.5 2MILES ¯ NPDES MUNICIPAL PERMITSANTA ANA RIVER WATERSHEDEXHIBIT SA-2(LAKE ELSINORE, CANYON LAKE,PERRIS, MENIFEE, WILDOMAR AREAS) CITY MS4 FACILITIES COUNTY MS4 FACILITIES RCFC&WCD MS4 FACILITIES OTHER FACILITIES !MAJOR OUTFALL SITES !SAR CORE MONITORING STATIONS SANTA ANA RIVER WATERSHED BOUNDARY SANTA MARGARITA RIVER MS4 PERMIT AREA BOUNDARY LANDFILL SITES SEWAGE TREATMENT PLANTS SANTA ANA RIVER/SAN JACINTO RIVER BLUE LINE STREAMS RIVERSIDE COUNTY BOUNDARY INCORPORATED AREAS FREEWAYS/HIGHWAYS PRIMARY STREETS ! ! P I E RC E S TR E E T BAKER STREETNICHOLS ROADTERRA COTTA ROADLEGEND STOCKDALE INDUSTRIAL PROJECTPRELIMINARY WQMP SITE PLAN - 30 - Appendix 2: Construction Plans Grading and Drainage Plans PREPARED BY:STOCKDALE INDUSTRIALCITY OF LAKE ELSINORECONCEPTUAL GRADING PLANCONCEPTUAL GRADING PLANWEST NICHOLS LOGISTICS CENTERIN THE CITY OF LAKE ELSINORE¾ ’’’” ’” ’” ’” ’” ’” “”“”’” ’”’” ’” ’” ’”’” ’” ’”’” ’’ PREPARED BY:STOCKDALE INDUSTRIALCITY OF LAKE ELSINORECONCEPTUAL GRADING PLAN BOT= 1292.51293.51293.5PREPARED BY:STOCKDALE INDUSTRIALCITY OF LAKE ELSINORECONCEPTUAL GRADING PLAN SEE SHEET 5 SEE SHEET 4 PREPARED BY:STOCKDALE INDUSTRIALCITY OF LAKE ELSINORECONCEPTUAL GRADING PLAN SEE SHEET 5 SEE SHEET 3 BOT= 126512671272BOT= 1254.5BOT= 12821284 1 2 8 4 2:1 2:1PREPARED BY:STOCKDALE INDUSTRIALCITY OF LAKE ELSINORECONCEPTUAL GRADING PLAN SEE SHEET 3 SEE SHEET 4 - 31 - Appendix 3: Soils Information Geotechnical Study and Other Infiltration Testing Data GEOTECHNICAL EVALUATION REPORT PROPOSED WEST NICHOLS LOGISTIC CENTER SOUTH OF NICHOLS ROAD AND EAST OF TERRA COTTA ROAD LAKE ELSINORE, RIVERSIDE COUNTY, CALIFORNIA NORTHPOINTE DEVELOPMENT, LLC November 21, 2023 J.N. 23-195 DRAFT ENGINEERS + GEOLOGISTS + ENVIRONMENTAL SCIENTISTS Offices Strategically Positioned Throughout Southern California RIVERSIDE COUNTY OFFICE 40880 County Center Drive, Suite M, Temecula, CA 92591 T: 951.600.9271 F: 951.719.1499 For more information visit us online at www.petra-inc.com November 21, 2023 J.N. 23-195 NORTHPOINT DEVELOPMENT, LLC 12977 N. Outer 40 Road, Suite 203 St. Louis, Missouri 63141 Attention: Mr. Logan Fitch Subject: Geotechnical Evaluation Report, Proposed West Nichols Road Logistics Center, South of Nichols Road and East of Terra Cotta Road, Lake Elsinore, Riverside County, California Dear Mr. Fitch: Petra Geosciences, Inc. (Petra) is submitting herewith our geotechnical evaluation report for the proposed construction of a new industrial warehouse building within the subject property. Site development consists of a proposed approximate 1.02 million square foot building as part of the proposed West Nichols Logistics Center. This work was performed in general accordance with the scope of services outlined in our revised Proposal No. 23-195P (dated May 17, 2023) and the Master Services Task Order Agreement - Contract Number 4642-0000-210065 (dated August 28, 2023). This report presents the results of previous and recent field exploration, laboratory testing, and our engineering and geologic judgment, opinions, conclusions and recommendations pertaining to geotechnical conditions and constraints of the proposed development. It has been a pleasure to be of service to you on this project. Should you have any questions regarding the contents of this report, or should you require additional information, please do not hesitate to contact us. Respectfully submitted, PETRA GEOSCIENCES, INC. Edward Lump, CEG J. Montgomery Schultz, GE Associate Geologist Chief Engineer DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 TABLE OF CONTENTS Page PURPOSE AND SCOPE OF SERVICES ..................................................................................................................... 1 LOCATION AND SITE DESCRIPTION ..................................................................................................................... 1 PROPOSED DEVELOPMENT .................................................................................................................................... 3 Geologic Hazard Zones ...................................................................................................................................... 4 LITERATURE REVIEW .............................................................................................................................................. 5 Previous Land Use ............................................................................................................................................. 5 Results of Aerial Photo Analysis ....................................................................................................................... 6 Historical USGS Topographic Maps .................................................................................................................. 8 Previous Geotechnical Reports .......................................................................................................................... 9 FIELD EXPLORATION ............................................................................................................................................. 13 Laboratory Testing ........................................................................................................................................... 14 FINDINGS .................................................................................................................................................................. 14 Regional Geology............................................................................................................................................. 14 Local Geology and Subsurface Soil Conditions ............................................................................................... 14 Landslide Complex .......................................................................................................................................... 18 Surface Water ................................................................................................................................................... 19 Groundwater ..................................................................................................................................................... 19 Expansive Soils ................................................................................................................................................ 20 Faulting ............................................................................................................................................................ 20 Liquefaction Potential ...................................................................................................................................... 21 INFILTRATION TEST RESULTS ............................................................................................................................. 21 CONCLUSIONS AND RECOMMENDATIONS ...................................................................................................... 22 General Feasibility ........................................................................................................................................... 22 Primary Geotechnical Issues ............................................................................................................................ 22 RECOMMENDATIONS FOR FURTHER STUDY ................................................................................................... 24 FUTURE IMPROVEMENTS AND GRADING ........................................................................................................ 25 REPORT LIMITATIONS ........................................................................................................................................... 26 REFERENCES ............................................................................................................................................................ 28 ATTACHMENTS PLATE 1 – GEOTECHNICAL MAP PLATE 2a – HILLSHADE RELIEF MAP PLATE 2b – HILLSHADE RELIEF MAP WITH LANDSLIDE OVERLAY DRAFT GEOTECHNICAL EVALUATION REPORT PROPOSED WEST NICHOLS LOGISTIC CENTER SOUTH OF NICHOLS ROAD AND EAST OF TERRA COTTA ROAD LAKE ELSINORE, RIVERSIDE COUNTY, CALIFORNIA PURPOSE AND SCOPE OF SERVICES Petra Geosciences, Inc. (Petra) is presenting herein the results of our geotechnical evaluation of the subject property. This report presents our findings and professional opinions with respect to the geotechnical feasibility of the proposed development, geotechnical constraints that should be taken into consideration during development of the site, and potential mitigation measures to bring the site to compliance from a geotechnical engineering viewpoint. To accomplish these objectives, our scope of services included the following: 1. Review of available published and unpublished literature and maps pertaining to regional faulting, seismic hazards, landslide hazards, and soil and geologic conditions within and adjacent to the site that could have an impact on the proposed development. 2. Conduct a site reconnaissance to evaluate existing conditions and to mark the site to obtain an underground utility clearance (Underground Service Alert) prior to commencement of our subsurface exploration. 3. Excavate, sample, and log seven (7) exploratory backhoe test pits to depths ranging from 7 to 8 feet below the ground surface within the project site. Four borings (P-1 through P-4) were drilled for the purpose of conducting pilot percolation tests. Borings were drilled using a truck-mounted hollow-stem auger drilling rig. 4. Laboratory testing of representative bulk samples of earth materials obtained from the test pits to determine their engineering properties. 5. Engineering and geologic analyses of the field and laboratory data as they pertain to the proposed construction. 6. Evaluation of faulting and seismicity of the region, and the possible impact of regional seismicity on the site and the proposed construction. 7. Preparation of this report presenting our findings and recommendations for site stability, grading and design of building foundation systems. LOCATION AND SITE DESCRIPTION The subject 61-acre undeveloped property is bounded by Nichols Road on the north, Terra Cotta Road on the west, Kings Way on the south, and Pierce Street on the east, in the city of Lake Elsinore, California. The location of the site is depicted on Figure 1 below. Excavation of earth materials within the western portion of the subject property has created a water quality basin used during rough grading of the Alberhill Ranch residential project west and up gradient of the subject site. An existing residential compound is present offsite southeast of Pierce Street. Parallel transmission lines are located along the south side of the DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 2 subject property. An abandoned single-family residence, located on the northwest side of Pierce Street, is a part of the subject site. An occupied single-family residence, located near the west end of Kings Way, is also a part of the subject site. Figure 1 – Site Location Map (USGS, 2023) Unimproved Coal Avenue transects the site in a west to east direction. Remnants of asphalt pavement suggest Coal Avenue was asphalt paved at some time, possibly as a part of the historic Terra Cotta City, which occupied the western portion of the subject property in the late 1800s and early 1900s. The subject property was subdivided into approximately 62 assessor’s parcel numbers in 1887 and 1888 (based upon San Diego County historical subdivision maps). A former railroad line (based on historical aerial photos) transected the northern portion of the subject site from west to east. Portions of the railroad bed are still DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 3 visible within the subject property with remnants of ballast observed; however, railroad ties and track have been removed. A brush fire recently occurred within the northern portion of the subject property. Dense natural vegetation mantles the remaining portions of the subject site. To hinder direct site access, boulders are present along the south side of Nichols Road and the northwest edge of Pierce Street. Boulder piles are also present in close proximity to the old railroad tracks. The site topography is characterized by low rolling hills with an easterly draining canyon paralleling the former railroad. As reported in our August 8, 2007 geotechnical report on a portion of the subject property, an existing underground 24-inch water-service line crosses the site in a general east-west trend following the existing Nichols Road/Coal Avenue alignment and exits the site near Baker Street. A 30-inch, east-west trending SAWPA sewer line is believed to traverse just inside the southern property line . Other unidentified underground utility lines may also be present within portions of the site. Several building structures have been previously demolished in the northwestern portion of the site near Petra’s exploration locations BA-1 and TP-10. Substantial building-material debris, including brick, slag, scrap metal, wood, tile, rubber, etc., was observed in this area. Building-material debris was also observed in the vicinity of our exploration locations B-4 and TP-4. The former rail line appears to have been removed from the site. Overhead electric lines were observed along the western property line and inside the southeastern property line along existing Pierce Street. A 48-inch concrete culvert was observed below Coal Avenue near the southwestern property boundary (Petra, 2007). PROPOSED DEVELOPMENT Based on the Conceptual Site Plan A5 by Northpoint Development, dated August 24, 2023, site development consists of an approximate 1.02 million square foot building with an adjacent guard house, perimeter parking, improvement to perimeter streets, and other miscellaneous improvements. It is expected that the new construction will be of metal-frame or concrete masonry wall construction and will be supported on conventional foundations with floor slabs constructed on grade. Petra also received Concept Grading Plan A5, an 80-scale plan, from NorthPoint dated August 15, 2023. The plan shows two water quality basins in the eastern portion of the subject site. The grading plan shows proposed finish floor elevation of the building along with perimeter retaining walls up to 10 feet in height in the western areas of the site. Cut slopes along the west side of the development are planned at a 3:1 horizontal to vertical (h:v) gradient to a maximum height of approximately 28 feet. A cut slope below Nichols Road is planned at a 2:1 (h:v) gradient to a maximum height of approximately 26 feet, and a similar DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 4 cut slope on the southern side of the property is planned at approximately 24 feet in height . Water quality basin fill slopes are proposed up to a maximum height of approximately 24 feet at a 3:1 h:v gradient. The concept finish floor elevation of the building is reported as 1,307 feet above msl (NorthPoint Development, 2023). To achieve this elevation, the maximum cut proposed for the site is approximately 31 feet in the southeasterly parking area. The maximum proposed fill is approximately 25 feet in the northeastern portion of the building area. It should be noted, however, that the ultimate fill thicknesses throughout the site will be greater due to the required remedial grading (i.e., removal and recompaction of existing unsuitable surficial soils, existing utilities, etc.) as recommended in subsequent sections of this report. Other site improvements are anticipated to include concrete walkways, paved vehicle and truck parking lots and access drives, truck docks, surface and subsurface drainage controls, and landscape planter areas. Structural details and foundation loads for the proposed building have not as yet been provided to our firm. Geologic Hazard Zones The site does not lie within an Alquist-Priolo Earthquake Fault Zone (Bryant and Hart, 2007: CGS, 2023). Review of the Fault Map for Riverside County indicates the subject site is not located within a fault zone requiring investigation (Riverside County, 2023). Review of the Liquefaction Susceptibility Map for Riverside County indicates the subject property is in a low and moderate area (Riverside County, 2023). The location of the site in relation to zone mapping is shown below in Figure 2. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 5 Figure 2 – Riverside County Liquefaction Susceptibility Map (2023) Field exploration activities should be influenced by the requirements to investigate areas with mapped geological hazards. However, at this time we have not been authorized to carry out field investigative activities related to liquefaction. Future studies will be required by the regulatory agencies to address this issue. LITERATURE REVIEW Previous Land Use In 1887 the Southern California Coal and Clay Company was incorporated to mine coal and clay to produce pipes, brick, and terra cotta. Terra Cotta City was subdivided, mining operations had begun, and construction of a factory was underway. By the end of 1887, the city was doubled in size. After a short time, however, it was realized that the coal and clay at Terra Cotta were of poor quality. Terra Cotta had a brief resurgence after 1896 when a railroad spur was finally constructed to nearby Alberhill, where the Alberhill Coal and Clay Company was mining another deposit. For a period of time between 1906 and 1912, a factory was operated in Terra Cotta by the California Fireproof Construction Company to manufacture pipes. In 1912 the plant was closed and by 1925 most of the buildings in the town were closed. Based upon our review of historical records/maps of mines within the Alberhill Ranch area, including the library at Pacific Clay Company, no mines were located within the subject property. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 6 The subject property includes a portion of the former Terra Cotta City. Based upon our review of historical aerial photographs and topographic maps and previous environmental reports related to a portion of the subject property indicated that most of the subject property was predominantly undeveloped land covered with relatively uniform vegetation from at least 1938 to sometime after 1953 and before 1967. Overall development within the property in 1938 appeared to consist of a railroad line in the west and north; what appears to be a clay pipe manufacturing plant, support out buildings, and aboveground storage tanks or clay kilns; and dry land farming in the east. The railroad line was present from at least 1901 to 1967 along Lake Street (north of Nichols Road) and the current alignment of Nichols Road west of Terra Cotta Road, as well within Terra Cotta City and the northerly edge of Coal Road. The railroad spur was depicted extending northeasterly offsite into the clay mine on the Hoist property. The onsite residence on Kings Highway was constructed sometime after 1978 and before 1985. Interstate 15 (I-15) was improved to its current alignment sometime between 1976 and 1989. By 2009, the eastern rough grading alignment of Nichols Road was visible including minor re-alignment of the northern portion of Terra Cotta Road. During 2009 through 2012 it appeared that earthwork included the western portion of the subject site. Between approximately 2021 and 2023, earthwork in the western area of the subject site created temporary storm water runoff ponds. Historical information reviewed during this assessment includes aerial photographs (dating back to 1938), USGS topographical maps (dating back to 1901), and interviews. EDR reports that fire insurance maps covering the target property were not found. Results of Aerial Photo Analysis Although aerial photographs can often be a valuable source of information in the assessment of historical land usage, it should be understood that information extrapolated from photographic images is strictly interpretation and not necessarily fact. For this reason, it may not be appropriate to draw conclusions regarding previous site activities based solely upon aerial photograph analysis. Aerial photographs with coverage of the subject site and vicinity were obtained from EDR and viewed by a representative of this firm. Photographs from the years 1938 through 2020 were provided by EDR. A summary of the information obtained during the aerial photograph review is provided in the Phase I Environmental Site Assessment (ESA) on the subject property by Petra, dated October 20, 2023. Copies of the aerial photographs obtained from EDR are provided in the Phase I ESA (Petra, 2023). A brief summary is provided below. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 7 1938 Photograph In this black and white photograph, a majority of the subject property appears undeveloped. A railroad line trends through the subject property, entering near the northwest corner and existing near the northeastern corner. A cluster of mostly small structures and one larger building, which are likely associated with the clay pipe manufacturing facility in Terra Cotta City, is noted in the western portion of the subject site. Ground disturbance and abundant dirt roads are visible in the eastern portion of the site, which may be related to dry land farming. This ground disturbance extends offsite to the north and offsite to the southeast and east. Although difficult to distinguish, there appears to be a small cluster of buildings in the central portion of the property, near the north edge of Coal Avenue. Nichols Road to the north and Kings Highway to the south are not visible. Unimproved Terra Cotta Road is visible to the west. Dirt roads from offsite areas to the south trend north to intersect Coal Avenue onsite. 1949, 1953, and 1961 Photographs In the 1949 photograph, six round structures near the northeast corner of Terra Cotta Road and Coal Avenue are no longer visible; however, some of the small buildings remain visible to the north of the former round structures. The railroad line remains present onsite. The eastern portion of the subject property is used for dry land farming. The 1953 and 1961 photographs show that all of the buildings formerly onsite appear to have been removed. 1967, 1975, 1978, and 1985 Photographs The 1967 photograph depicts minimal changes to the subject property and surrounding lands, except for the railroad line. Dirt roads are visible on both sides of the former railroad line and it appears the tracks have been removed. The 1978 photograph shows the subject property as predominantly undeveloped land. Dirt roads from the south and east continue to intersect Coal Avenue onsite. The 1985 aerial photograph shows somewhat uniform native vegetation throughout the subject property. A single-family residence is visible onsite near the southwest corner of the site. Access to the residence is from Terra Cotta Road to the west, which appears to show Kings Way for the first time. 1989, 1990, and 1994 Photographs In the 1989 aerial photograph, most of the subject property is undeveloped and mantled with uniform native vegetation. Nichols Road remains absent along the northern edge of the subject property. The 1990 photograph depicts no significant changes to the subject property, except an onsite residence is visible on the north side of Pierce Street in the southeast corner of the subject property. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 8 2002, 2005, 2009, and 2012 Photographs In these photographs, significant dirt road activity is visible in the southeastern portion of the subject property extending offsite to the south. Dirt road activity has increased onsite near the corner of Terra Cotta Road and Coal Avenue. Earthwork for Nichols Road is visible offsite and slightly encroaches into the northwest corner of the subject property. This earthwork is also changing the alignment of Terra Cotta Road to a “T”-shaped intersection with Nichols Road. The 2005 color aerial photograph depicts vegetation management activity in the eastern half of the subject site. The western half of the site continues to support native vegetation. The 2009 aerial photograph shows earthwork activity associated with the eastern extension of Nichols Road across the north boundary of the subject property; however, the earthwork does not extend east to the eastern boundary of the site. What appears to be grading activity is visible near the northeast corner of Terra Cotta Road and Coal Avenue. Earthwork associated with Alberhill Ranch to the west across Terra Cotta Road is visible, including two large offsite basins. The 2012 aerial photograph shows Nichols Road improved along the north edge of the subject property. Additional grading appears to have occurred west of Terra Cotta Road, between Nichols Road and Coal Avenue. 2016 and 2020 Photographs The 2016 aerial photograph depicts the sewer lift station near the northeast corner of the subject property. The 2020 aerial photograph depicts no significant changes to the subject property. Two small holding ponds are observed north of Coal Avenue and west of the power lines that extend south from Nichols Road. Google Earth Photographs Petra reviewed available photographs of the subject property and immediate vicinity, after 2020, on Google Earth from April 2023. A relatively large, “L”-shaped pond was observed in the western portion of the subject property north of Coal Avenue. Smaller ponds are also present in this area. Historical USGS Topographic Maps Petra reviewed the historical USGS topographic maps of the site and vicinity provided by EDR which included Target Quad’s: dated 1901, 1953, 1954, 1973, 1974, 1978, 1982, 1988, 1997, 2012, 2015, and 2018. These maps generally support observations made from the aerial photographs reviewed. Copies of the maps are provided in the Phase I ESA by Petra (dated October 20, 2023). DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 9 Previous Geotechnical Reports Petra has reviewed previous geotechnical reports on the northern portion of the subject property by Petra (2007) and Nichols Road (Petra, 2011). Pertinent information provided in an earlier geotechnical report by G.A. Nicholl and Associates, Inc. (1990), which covered the approximately 1,900-acre Alberhill Ranch site and covering only a small portion of the subject property, is used throughout this report. The most pertinent findings made from reviewing the Petra reports are paraphrased herein with any commentary/discussion by Petra in parenthesis and italics. ➢ Petra, Geotechnical, Inc., 2007 The soils encountered in the exploratory borings and test pits during this investigation included undocumented fill (0 to 3 feet thick), recent alluvium (0 to 6 feet thick), older alluvium (0 to 25 feet thick), landslide deposits (0 to 35 feet thick), as well as Pauba Formation bedrock and Silverado Formation bedrock. The surficial materials, undocumented fill and/or alluvium, were generally porous and loose to medium dense, while the more competent older alluvium, landslide deposits and Pauba Formation materials were generally medium dense to locally very dense. The underlying Silverado Formation bedrock was generally soft to very hard and consisted of interbedded claystone, siltstone and sandstone. Based on Petra's review of available geotechnical and geologic reports, site reconnaissance, limited subsurface exploration and laboratory testing, the following key geotechnical issues were presented. • Remedial Grading – Remedial grading was to consist of removal and recompaction of unsuitable materials ranging from the upper 3 to 6 feet across the majority of the site. Materials subject to removal include existing undocumented fill and low-density recent alluvium. Over-excavation of highly expansive material, including older alluvium and/or claystone found in the upper units of the Silverado Formation, was recommended below and adjacent to proposed structures. Landslide debris within proposed building-pad grades should be over-excavated to provide more uniform foundation support. • Groundwater – Groundwater was encountered at variable depths in several exploratory borings across the site. Groundwater was encountered in our exploratory borings as shallow as 15 feet below existing ground surface in the eastern portion of the site . Groundwater was not anticipated to impede grading during site development. • Faulting –The site does not lie within an Alquist-Priolo (AP) Fault Hazard Zone. Active faulting, requiring structural setbacks, is not anticipated on the site. The site does lie in close proximity (2.1 miles) to the active Elsinore fault, Glen Ivy segment. • Liquefaction – The potential for liquefaction and excess ground deformation at the site appears to be low. Further evaluation of ground-deformation parameters may be needed, depending on the proposed grading or building types, for areas in the central portion of the site where alluvial deposits were identified. • Landslide Deposits – Ancient landslide deposits/debris were located within the northwest portion of the property. These materials are considered generally competent to support surcharge loads in their current condition, however, if cut slopes were planned within this area buttressing and or stabilization fills are recommended. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 10 • Hard Rock – Surficial soils and bedrock underlying the site should be readily excavated utilizing conventional earthmoving equipment. Localized heavy ripping may be necessary in the central portion of the site where shallow hard bedrock materials may be encountered. • Blasting – No blasting is anticipated. • Expansion Potential – Based on laboratory testing, onsite soils and bedrock materials were found to range from LOW to VERY HIGH expansion potential. Highly expansive soils were recommended to be removed and replaced with select engineered fill in the upper approximately 5 to 8 feet of building pads. • Foundations –Conventional slab-on-ground foundations would likely be satisfactory for commercial structures provided remedial grading is employed to mitigate the effects of expansive soils, compressible soils or non-uniform landslide debris. ➢ Petra Geotechnical, Inc., 2011 The interim report presented a summary of the observation and testing services provided by Petra Geotechnical, Inc. (Petra) during the phase II rough-grading operations to develop the subject portions of Nichols Road associated with Tract 28214 (Alberhill Ranch) located in the City of Lake Elsinore. The grading reported also included re-grading of portions of the previously rough graded roadway. Conclusions and recommendations pertaining to the suitability of the grading for the proposed temporary roadway construction were provided herein. (Petra: the graded Nichol Road alignment is provided below in Figure 3). The purpose of this phase of rough and re-grading reported was to construct a portion of Nichols Road, with associated slopes, from approximate Station 30+00 (near the intersection with existing Alberhill Ranch Road) through Station 82+50 (near the existing paved portion of Nichols Road). The travel lanes south of the ultimate centerline of Nichols Road were rough graded to final subgrade elevations to allow for pavement construction to connect Tract 28214 with the existing paved portion of Nichols Road near Interstate 15 as a two-lane road. The travel lanes north of the centerline were graded low of final subgrade elevations. Re-grading was conducted from the previously rough grading portions of Nichols Road between Station 30+00 through 55+00 and 65+60 through 77+00, as previously reported by Petra (Petra, 2006b, c). DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 11 Figure 3 – Graded Nichols Road Alignment (Petra, 2011) [Logistics Center is South of Nichols Rd from Approximately Station 50+75 at Intersection of Nichols Rd. and Terra Cotta Rd to Approximately Station 78+00 at Property Boundary of Lift Station] In addition to the removals and fill placement, the existing ascending slope along the north side of Nichols Road between approximate Station 52+50 through 65+60 was cut to a 3:1 (horizontal: vertical) grade; however, sections of this cut slope (approximate Stations 55+00 through 57+00 and 63+00 through 64+50) were temporarily over steepened due to existing power poles. Ancient landslide materials were encountered during grading along the northern side of Nichols Road from about Stations 50+00 to about Station 65+60. The materials within the landslide consisted of thick-bedded sandstone, locally intensely fractured siltstone and claystone of the Silverado and Pauba Formations. The in-situ landslide material was generally deemed competent and suitable for fill placement. Groundwater or seepage was not encountered within the over-excavation or removal bottoms during the grading operations within the subject portions of Nichols Road. Subdrains were previously installed during grading of the stabilization fill slope on the northern side of Nichols Road between Stations 45+80 through 55+00. Four outlet pipes extend into Nichols Road and are intended to tie into the future storm drain pipe at approximate Stations 48+00, 49+90, 52+00 and 55+00. • Ground Preparation In areas to receive compacted fill, low-density surficial soils, which consisted of undocumented fills, compressible alluvium, and disturbed or eroded engineered fill, were over-excavated to expose competent previously placed engineered fill, landslide material or alluvium. In general, the over-excavation depths were approximately one foot or less in the previously graded portions of Nichols Road and varied from DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 12 approximately 4 to 7 feet below the original ground surface in the alluvial removal area between Stations 77+00 through 82+50. Due to a fill-over-cut condition that was created by the proposed fill slope/berm for Basin #3, located above the cut slope near Stations 61+50 through 63+00, a keyway was excavated into competent landslide material along the toe-of-slope berm and tilted into the slope a minimum of 2 percent. Prior to placing fill, the exposed removal bottom surfaces/keyway were observed and determined suitable for fill placement by a geologist from Petra. Following this observation, the exposed bottom surfaces were watered as necessary to achieve moisture content near or slightly above optimum and then compacted by rolling with loaded scrapers and dozers. • Fill Slopes Fill slopes were constructed during this phase of grading at slope ratios of 2:1 (h:v) or flatter to a maximum height of approximately 5 feet (northern side of Nichols along Stations 77+00 to 82+50). A 1- to 2.5-foot- high temporary descending fill slope was graded near the ultimate centerline of Nichols Road to support the pavement for travel lanes on the southern half of Nichols Road . Finish-surface compaction on the fill slopes was achieved by building the slope to design grade and track-walking to achieve surface compaction. The fill slopes are considered to be both grossly and surficially stable to the heights and inclinations at which they were constructed and are expected to remain so under normal conditions provided they are properly maintained and landscaped in accordance with recommendations presented later in that report. As is the case with most manufactured slopes, they are subject to erosion. • Stabilization Fill Slope As noted, a stabilization fill slope was previously constructed during the 2006 grading operation in the southerly facing slope on the northern side of Nichols Road from Station 45+80 to Station 55+20. (Note: The portion from approximately Station 50+75 to 55+20 would be in front of the currently proposed logistics center.) The proposed cut slope was over-excavated and subsequently reconstructed as an engineered fill slope. A 20- to 40-foot wide by 10-foot-deep keyway was cut into competent landslide material along the toe-of-slope. (Note: This keyway did not penetrate the whole landslide and only extends for a small portion in front of the Nichols Logistics Center site. This keyway is not expected to be able to provide stability for the logistics center.) • Cut Slopes A 3:1 ascending cut slope was constructed during this phase of grading to a maximum height of approximately 26 feet along the northern side of Nichols Road between approximate Stations 55+20 through 65+60. Sections of this cut slope (between Stations 55+20 through 57+30 and 62+80 through 64+40) have been temporarily over steepened up to approximately 1.7:1 (h:v) and 2:1 (h:v), respectively due to existing power poles. It was our understanding that these poles were to be relocated by the utility company to the edge of the right-of-way within the next 6 months. Following the pole relocation, the cut slope sections between Stations 55+20 through 57+30 and 62+80 through 64+40 was to be trimmed back to the design 3:1 grade. (Note: Edison has recently done work relocating power lines along Nichols Road, which may have included changes to the slopes on the uphill side of the road.) The cut slope was excavated into landslide materials consisting of both Silverado and Pauba formation bedrock. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 13 General Note: During a previous investigation by Petra (2005) for all of Nichols Road it was recommended that some stabilization measures along the uphill side of Nichols Road be implemented for its installation and long-term stability. These measures were declined by the landowners and city at the time of Nichols Road construction. Nichols Road was constructed on a “Temporary Basis” and it was understood that additional measures would be required in the future for long term stability of the roadway and surrounding properties. FIELD EXPLORATION Our most recent subsurface exploration was performed on September 21, 2023. This subsurface exploration included excavation of seven (7) geotechnical exploratory test pits (identified herein as Test Pits TP-1 through TP-7) to depths up to 8.5 feet below the existing ground surface. Test pits were excavated by a rubber tire backhoe. In addition, four shallow percolation test borings (PT-1 through PT-4) were advanced to depths of approximately 3 feet or 8 feet within the four proposed water quality basin areas. Percolation testing was completed on October 16, 2023. Percolation borings were drilled utilizing a truck-mounted, hollow-stem auger drill rig. The locations of all test pits and borings are shown on Plate 1. Earth materials encountered in each of the previous exploratory borings were field classified and logged in accordance with Unified Soil Classification System procedures. In addition, our subsurface exploration included the collection of bulk samples and relatively undisturbed samples of the subsurface soils for laboratory testing purposes. Bulk samples consisted of selected earth materials obtained at various depth intervals from selected test pits and previous borings. During previous geotechnical studies, relatively undisturbed samples were collected using a 3-inch outside- diameter (o.d.) modified California split-spoon soil sampler lined with 1-inch-high brass rings. The modified sampler was driven with successive 30-inch drops of a hydraulically operated 140-pound automatic trip hammer. Blow counts for each 6-inch driving increment were recorded on the field logs. The central portions of the driven core samples were placed in sealed containers and transported to our laboratory for testing. In addition to the above sampling method, Standard Penetration Tests (SPT's) were also previously performed at selected depth intervals in accordance with the American Society for Testing and Materials (ASTM) Standard Procedure D 1586. This method consists of mechanically driving a 2-inch o.d. unlined standard penetrometer sampler 18 inches into the soil with successive 30-inch drops of the 140-pound automatic trip hammer. Blow counts for each 6-inch driving increment were recorded on the exploration logs. The number of blows required to drive the standard split-spoon sampler for the last 12 of the 18 inches DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 14 is identified as the uncorrected standard penetration resistance (N). Disturbed soil samples from the unlined standard penetrometer sampler were placed in plastic bags and transported to our laboratory for testing. Laboratory Testing In order to evaluate the engineering properties of the onsite soils, a number of laboratory tests were performed on selected samples considered representative of the materials encountered during our recent field exploration. Testing included maximum dry density and optimum moisture content, expansion potential, Atterberg Limits, hydrometer, percent passing the #200 wash, soluble sulfate and chloride content, pH, and resistivity, direct shear. Laboratory tests associated with previous studies of the property included the determination of in-place moisture content and dry density, maximum dry density and optimum moisture content, expansion potential, #200 wash, sieve analysis, soluble sulfate and chloride content, pH, resistivity, consolidation characteristics, and shear strength. FINDINGS Regional Geology The site lies within the northern portion of the Peninsular Ranges Geomorphic Province (CGS, 2002). The Peninsular Range Province extends from the tip of Baja California north to the Transverse Ranges Geomorphic Province and is characterized by northwest trending mountain ranges separated by subparallel fault zones. The San Bernardino Mountains provide the boundary between the Peninsula Range Province and the Transverse Ranges Province. In general, the province is underlain primarily of plutonic rock of the Southern California Batholith. These rocks formed from the cooling of molten magma deep within the earth's crust. Intense heat associated with the plutonic magma metamorphosed the ancient sedimentary rocks into which the plutons intruded. The Peninsular Range Geomorphic Province is generally characterized by alluviated basins and elevated erosion surfaces. Local Geology and Subsurface Soil Conditions More specifically, the subject site is mapped as Holocene to late Pleistocene Young alluvial channel deposits (map symbol Qyaa) in the main drainage, late to middle Pleistocene Old alluvial channel deposits (map symbol Qoa) in the low hillsides in the central portion of the site, and the Paleocene Silverado Formation (map symbol Tsi) in the higher elevations of the southern subject property (Matti and Weber, Jr., 2003). These soils are described as unconsolidated to moderately consolidated silt, sand, and gravel deposits. Where encountered in borings on the subject property, alluvial soils consisted of moist to slightly DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 15 moist, loose to medium dense, silty fine- to course-grain sand with variable concentrations of fine to coarse gravel. A portion of the regional geologic map of the subject property and vicinity is provided below on Figure 4. The site does not lie within an Alquist-Priolo Earthquake Fault Zone (Bryant and Hart, 2007: CGS, 2023) or a Riverside County Fault Zone (Riverside County, 2023). The subject property is mapped in a low and moderate liquefaction susceptibility zone (Riverside County, 2023). Earth units encountered onsite consisted of artificial fill, topsoil, landslide material, young and old alluvial deposits, and sedimentary bedrock of the Silverado Formation. Artificial fill soils (documented and undocumented) exist locally within the site in the existing basin area along the west side of the subject property, where an old culvert crosses Coal Avenue near the power poles, and along the old railroad bed. Where encountered or observed, fill soils are typically less than 5 feet in thickness. O ther localized areas of fill may be present, such as the east side of Terra Cotta Road, which descends to the subject property. Topsoil throughout the property is typically 2 to 3 feet in thickness. Surface desiccation cracks throughout the property suggest topsoil is expansive in nature. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 16 Figure 4: A Portion of the Geologic Map of the Elsinore 7.5’ Quadrangle (Morton and Weber Jr., 2003). A large landslide complex, which is located predominantly north of Nichols Road, extends onto the north central portion of the property and all the way to the proposed building pad (G.A. Nicholl, 1990). Within the subject property, bedrock of the Silverado Formation is encountered underlying the slide debris at maximum depths of 35 and 45 feet. Slide debris is underlain by Old alluvial-channel deposits. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 17 Where encountered in borings and test pits onsite, native alluvial soils outside the limits of the landslide are typically between 3 and 10 feet in thickness, except in the eastern portion of the site, where old alluvium is on the order of 12 to 24 feet in thickness. Underlying native alluvial soils and landslide materials is the Silverado Formation. Granitic boulders found along the north and east edges of the subject property, and stockpiled on or near the old railroad bed, appear to have been imported to the subject property. Granitic cobble to small boulders are common on the surface of the landslide. The geological units observed onsite are discussed in detail below. • Artificial Fill (map symbol Afu) – Undocumented-fills were encountered in several areas throughout the site. These materials were comprised of clayey sand which were greyish brown to brown, generally loose and low in optimum moisture. The fills observed ranged from approximately 0.5 to 3 feet in thickness. Fill soils may be thicker beneath portions of the former rail-line alignment. • Topsoil (no map symbol) – Topsoil was present at the surface over portions of the site and consisted of dark to very dark greyish brown, clayey sand to sandy clay. These materials were generally medium dense to dense or very stiff, dry to slightly moist and somewhat porous. The topsoil observed was approximately 2 feet in thickness. • Alluvium (map symbol Qya) – Alluvium of Holocene age was present within the east-west trending drainage channel and consisted of yellowish brown to greyish brown to dark greyish brown, fine to coarse sand, silty sand and gravelly sand. These materials were generally loose to locally dense, dry to moist and somewhat porous. • Older Alluvium (map symbol Qoa) – Older alluvium was observed across the majority of the site underlying undocumented fills, landslide deposits and/or alluvium and overlying bedrock. These materials were typically silty to clayey sand to sandy clay and silt, which were generally dark brown to yellowish brown to olive grey, dry to wet, stiff to very stiff and medium dense to dense. Thickness of this unit ranged from as little as 2.5 feet in the western end of the site to as much as 24 feet at the eastern end of the site (B-2). • Landslide Deposits (map symbol Qls) – Landslide deposits were observed across the northwestern portion of the site. These materials were typically silty sand, sandy silt, clay and sandy clay, which were generally olive grey, pale yellow and brownish red, moist to wet, stiff to very stiff and medium dense to dense. These deposits were generally sheared and jumbled. • Pauba Formation (map symbol Qps) – Pauba Formation bedrock was observed in the south central and southwestern portion of the site overlying Silverado Formation bedrock. These materials were typically silty to gravely cemented sandstones with occasional small cobbles to boulders. These materials were generally brownish yellow to red, dry to moist, soft to hard, and moderately to highly weathered. • Silverado Formation Bedrock (map symbol Tsi) – Silverado Formation bedrock exposed on the site consisted of non-marine claystone with interbedded sandstone and siltstone. This unit consisted of iron-stained, bluish grey to grey to olive claystone with interbeds of iron-stained pale yellow, yellow to olive yellow, silty to clayey sandstone/siltstone. Bedding varied from laminated to DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 18 massive, dipping generally to the southwest or southeast. Bedrock was mapped at very shallow depths (approximately 3 feet below grade) in the southeastern portion of the property (B-4, TP-3 and TP-4). Test pit and boring locations are presented on the Field Exploration Map (Plate 1). Landslide Complex As noted above a large landslide complex exists in the vicinity of the site and intrudes onto the property. This landslide complex is located uphill from the property, with the onsite portion at the lowest elevation of the slide. It extends several thousand feet horizontally offsite, and several hundred onsite. The elevation gain is up to about 400 feet above the site. The area of the slide above the current logistics center site was previously investigated by Petra and another engineering firm. G.A. Nicoll & Associates, Inc. (Nicoll, 1990) conducted a geotechnical feasibility investigation of the Alberhill Ranch property and surrounding areas between August of 1987 and January of 1988. The purpose of their investigation was to provide geotechnical recommendations for a project Environmental Impact Report and to assist their client in determining what areas were most feas ible for development. Their investigation included the drilling of many large-diameter borings including within the portions of the landslide complex above the current site. Petra previously investigated the eastern portion of the slide complex in the area known as the “Hoist Property” (see Petra 1990, 2006). Our work did not look at the larger western portion above the current property. We have prepared a map showing the basic topographic relief in a hillshade of the site and uphill areas where the slide complex exists (see Plate 2a). We have then overlain that map with the locations of the previous borings by G.A. Nicoll including some by Petra from our 1990 investigation and they are shown on our landslide map (Plate 2b). The eastern portion of the slide complex on the “Hoist Property” was noted by Petra to have the following characteristics. The slopes within the site ascend towards the north approximately 400 feet in height and have slope ratios that range up to approximately 2:1 (horizontal to vertical). The majority of these slopes are underlain by landslides that have occurred within bedrock materials of the Silverado Formation. These landslides are generally on the order of 10 to 65 feet deep with slide plane angles of approximately 5 to 20 degrees to the southwest. Generally, the Silverado Formation bedrock was observed to dip to the south-DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 19 southwest at angles of approximately 5 to 35 degrees; however, variations of bedding strikes and dips are not uncommon. The western portion of the slide was noted to be deeper and larger, but the evaluation was limited as the property boundary ended part way into the deeper complex. Therefore, Petra has previously not fully evaluated the larger portion above the subject logistics center. It was recommended in the work on the “Hoist Property” that stabilization measures such as removals of the upper portion of the slide complex and the installation of shear keys to stabilize the land would be required. No work has been done on the land to date, and therefore no stabilization measures within the slide mass have been undertaken so far. Given that the current development proposed would attempt to remove the lower portion of the landslide which is the portion that would tend to provide stabilizing influence on the slide, further evaluation should be conducted. Surface Water No indication of surface water was observed on the site at the time of our recent field exploration, except for ponded water in the water quality basin in the west portion of the subject property. Dry, formerly ponded areas were observed in the northeasterly portion of the subject property, near the intersection of Pierce Street and Coal Avenue. The subject property is covered by one Flood Insurance Map (FIRM), FIRM 06065C2 028G. The subject property is mapped within Zone X, which is defined an area of minimal flood hazard, or “0.2 percent annual chance flood hazard, 1 percent chance of annual flood with average depth less than 1 foot, or with drainage areas of less than 1 square mile.” The FEMA FIRMette maps effective date is listed as August 28, 2008. Groundwater The site is located within the Elsinore Valley Groundwater Sub-Basin, (California Department of Water Resources, [CDWR], 2023). No public water wells are mapped in close proximity to the subject property. One groundwater well is mapped southwest of the subject site on the CDWR Water Data Library (CDWR, 2023), in McVicker Park. Between 2017 and 2021 groundwater depth is reported approximately 50 feet below the ground surface (bgs). Groundwater was encountered previously in geotechnical borings drilled within the subject property. Borings placed in Nichols Road near the northeast corner of the subject site reported groundwater at depths of 16.5 to 13.5 feet bgs (Petra, 2005). Near the north central portion of the subject property, groundwater DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 20 was encountered locally at a depth of approximately 50 feet bgs (Petra, 2007). Overall, a shallow groundwater table is not anticipated except in the northeasterly portion of the subject property, nearest Temecula Wash. Though flow direction beneath the subject site is unknown it is believed to be in an easterly direction toward Temescal Wash, which flows in a northerly direction. It should be noted that, based upon elevations of Temescal Wash south of the subject property, areas south of the subject property likely have groundwater flow to the south toward Lake Elsinore. As noted above, groundwater was encountered in several of our exploratory borings across the site (Petra, 2007). Groundwater levels were encountered at relatively shallow depths near the existing drainage channel and at greater depths in our deeper bucker auger exploration (Borings B-2, B-7, BA-1 and BA-2) at elevations ranging from approximately 1,253 to 1,281 feet above msl. Groundwater was also encountered during our previous exploratory drilling conducted in May 2005 (B-17, B-18 and B-19) along the northeastern property boundary at elevations ranging from approximately 1,258 to 1,260 feet msl (Petra, 2005). Expansive Soils Based on recent laboratory testing, onsite soils and bedrock materials were reported as Medium (EI=67) and high (EI=123) expansion potential. Previous reports (Petra, 2007) indicate the expansion index (EI) of onsite soils range from very low to very high (EI of 2 to 151). Expansion index testing provides a common framework for evaluation expansion potential by remolding soils at a saturation of 50 percent then inundating the soils and measuring the percentage of expansion with a very light load of 1 psi (144 psf) on it. There are limitations on the usefulness of EI for direct measurement of swell values and swell pressures . During the 2007 investigation two lab tests for consolidation indicated extremely high values of swelling when inundated at relatively higher confining pressures. They were inundated at 2 ksf normal pressures and swelled up to 5 percent. After swelling the load was further increased, and normal loads approaching 20 ksf were required to suppress the swelling forces. Therefore, we can conclude that the soils at the site may be subject to very high expansion/ swelling/ volume change with very high pressures. Faulting Based on our review of the referenced geologic maps and literature, no Holocene-active faults are known to project through the property. Furthermore, the site does not lie within the boundaries of an “Earthquake Fault Zone” as defined by the State of California in the Alquist-Priolo Earthquake Fault Zoning Act (CGS, 2018) or a Riverside County Fault Zone. The Alquist-Priolo Earthquake Fault Zoning Act (AP Act) defines an active fault as one that “has had surface displacement within Holocene time (about the last 11,700 DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 21 years).” The main objective of the AP Act is to prevent the construction of dwellings on top of Holocene- active faults that could displace the ground surface resulting in loss of life and property. However, it should be noted that according to the USGS Unified Hazard Tool website, or the California Geological Survey’s (CGS) interactive map of Earthquake Zones of Required Investigation (EQZapp, 2023), the Elsinore Fault zone (stepovers combined), located approximately 1.57 miles (2.53 km) west- southwest of the site, would probably generate the most severe site ground motions and, therefore, is the majority contributor to the deterministic minimum component of the ground motion models. Therefore, the subject site is located at a distance of less than 5 miles (8 km) from the surface projection of this fault system, which is capable of producing a magnitude 6 or larger event with a slip rate along the fault greater than 0.04 inch per year. As such, the site should be considered as a Near-Fault Site in accordance with ASCE 7-16, Section 11.4.1. Liquefaction Potential We have not done a specific look at the site’s liquefaction potential at this stage, as the client has not yet authorized our proposed liquefaction exploration activities. However, there are alluvial soils present onsite, and groundwater observed within these soils, therefore, liquefaction may be a consideration which would require further specific study. INFILTRATION TEST RESULTS Four infiltration test holes (P-1 through P-4) were completed within the subject property at depths of 3 feet to 8 feet bgs to assess infiltration rates of the near-surface onsite soils for preliminary design of water quality facilities to manage storm water runoff. These tests used the Falling Head Test Method (RCFCD, 2014). Infiltration rates were then calculated using the Porchet Method (RCFCD, 2014), commonly called the “inversed auger-hole method.” The infiltration tests were conducted at a different depth interval corresponding to 1, 2, and 3 feet below the bottom of the proposed basins. Each test hole consisted of an eight-inch diameter boring drilled with a truck-mounted hollow-stem auger drill rig. The holes were pre-soaked immediately after drilling. Variable soils or formational material were encountered in each of the test locations. In P-1 (Area 1), Old Alluvium soils within the percolation zone consisted of stiff, slightly plastic clay. In P-2 (Area 2), Old Alluvium soils within the percolation zone consisted of firm sandy silt. In P-3 (Area 3), hard siltstone of the Silverado formation was encountered. In P-4, moderately hard sandstone of the Silverado formation DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 22 was encountered. Test locations are shown on Plate 1. The un-factored infiltration test rate results are summarized below in Table 1. TABLE 1 Summary of Infiltration Test Rates Percolation Test Designation Depth of Test Zone (feet below surface) Percolation Rate (gallons/day/ft2) Infiltration Test Rate (inches/hour) P-1 1 - 5 0 0 P-2 1 - 4 0.13 0.01 P-3 0 – 3.5 0.74 0.06 P-4 4 - 8 0.85 0.07 The infiltration rates are less than the minimum threshold of 0.3 inches/hour. As a result, site soils are considered non-permeable and would be unsatisfactory for use in a storm water infiltration system. CONCLUSIONS AND RECOMMENDATIONS General Feasibility Based on our review or the prior reports and data from our recent geotechnical evaluation, development of the subject project is considered feasible from a geotechnical engineering standpoint; however, certain issues exist which will require addressing. It is recommended that the following geotechnical issues be considered by the Client during this preliminary phase of site design. Primary Geotechnical Issues Our professional opinion, from a geotechnical engineering viewpoint, regarding various aspects of site conditions and/or proposed development, is presented herein. The following items are the salient points of our preliminary geotechnical evaluation that will require addressing and/or we recommend be considered for future site development. • Liquefaction, Landslides, and Secondary Seismic Effects: Based on Riverside County’s mapping portal (see Figure 2 above), the eastern and west central portions of the site are located within areas subject to moderate liquefaction susceptibility (Riverside County, 2023). Further study is recommended for the central drainage and the eastern portion of the subject property to evaluate liquefaction. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 23 The subject property does not exhibit variable topography that is prone to landsliding; however, one of the most significant geotechnical factors affecting the project site is the presence of a landslide complex mapped on undeveloped land predominantly across Nichols Road from the subject property. Based upon previous field studies, the slide encroaches onto the northern portion of the subject property (Petra, 2007). Proposed cuts below Nichols Road range up to approximately 30 feet, which is anticipated to expose the toe of the landslide and/or remove a significant portion of the lateral sliding resistance. o Mitigation may include construction of an onsite buttress or stabilization fill slope to replace removal of the sliding resistance to create proposed grades on the subject property. o Buttressing offsite above Nichols Road may also be considered. o Further assessment is recommended for cut slopes along the south side of Nichols Road as well as the subject property as a whole to evaluate slope stability. o Relocating the planned building further to the south to increase the area along Nichols Road for a keyway/buttress construction is recommended. From the conceptual plans it appears that at least 40 to 50 feet of additional distance between Nichols Road on the north and the edge of the parking on the south of the cut slope could be easily achieved. Even more may be possible to be gained with adjustments to the parking footprints, in order to allow for as much room as possible for keyway/ buttress development. o Increasing site grades to reduce the amount of cut into the toe of the landslide could also be considered. • Groundwater: Recent test pits excavated to a maximum depth of 8 feet below the ground surface did not encounter groundwater or subsurface seepage. Previous studies reported groundwater at relatively shallow depths of 13 to 16.5 feet below the ground surface (bgs), predominantly in the northeastern portion of the subject site (Petra, 2005, 2007). Overall, groundwater was generally not encountered throughout the subject site, except in the landslide mass in the north central portion of the subject property at a depth of approximately 41 and 50 feet bgs (Petra, 2006, 2007) and near the upper end of the drainage flowing west to east through the north central portion of the site at a depth of 16 feet bgs. o Shallow groundwater may impact water quality basins proposed for the northeast portion of the property as well as liquefaction potential. In areas underlain by formation, groundwater is not anticipated to affect the subject development. o Installation of subdrains below the building footprint are likely to help facilitate groundwater flow after grading. • Expansive Soils: One of the most significant geotechnical factors affecting the project site is the presence of expansive soils onsite. Soils encountered previously onsite were reported to range from non-expansive to expansive with an expansion index (EI) of 2 to 151 (Petra, 2007). Recent laboratory testing of soils within the subject site reported an EI of 67 (medium) and 123 (high). While the claystone of the Silverado formation appears to be limited in extent, some of the other formation material that will be used as fill may potentially be expansive. As such, some selective grading may be considered to help mitigate the adverse effects of the expansive soils. o Selective grading would entail removing expansive material by over-excavation of the building pad to a depth by further study by most likely on the order of 6 to 15 feet to remove such materials, replacing them with less expansive native fill soils. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 24 o Pavement areas could be similarly over-excavated of expansive soils, typically to depths of 2 to 5 feet, replacing them with less expansive granular fill to reduce not only the pavement section but the potential for damage to curbs, sidewalks, and other shallow expansion-sensitive structures. o Further testing and evaluation of the quantities of various earth materials expansion potential should be conducted. o Final confirmation testing for expansion potential should also be performed during site grading for the purpose of final foundation design. o Other mitigation measures could include the use of cement or lime treatment to blend with the expansive soils to reduce their expansion potential. o Another potential mitigation measure may be the use of over-excavation and moisture conditioning of the expansive soils prior to recompaction into a suitable fill pad which would then be encapsulated in vapor retarders to seal in moisture and prevent further volume change. A cutoff trench around the perimeter would be required in conjunction with this method. • Excavation Characteristics: The existing site soils are expected to be readily excavated with conventional earthmoving equipment. Oversize rocks (i.e., 12-inches in one dimension or greater) exist along the north and east edges of the subject property and are locally stockpiled in proximity to the former railroad bed. Oversize rock may also be present in the main onsite drainage. Oversize rock should be disposed of either offsite or properly buried within the planned deeper fills in an approved engineered fashion, a minimum of 10 feet below finish pad grade(s). • Strong Ground Motions: The site is located in a seismically active area of southern California and will likely be subjected to very strong seismically related ground shaking during the anticipated life span of the project. Structures within the site should therefore be designed and constructed to resist the effects of strong ground motion in accordance with the 2022 California Building Code (CBC). A site-specific ground motion hazard analysis may be of benefit for a structure of this size and scope. A site-specific analysis would allow for the determination of the correct soil profile by conducting shear wave velocity measurements. Then an analysis could be performed with actual site response characteristics input instead of potentially conservative assumptions about the site behavior. Based on our past experience with soil materials such as those present onsite, after grading and establishing of the building pad, actual measurements of the site are potentially leading to a site class more likely that of a Site Class C site. This has implications for the required structural design, where significant savings may be possible in structural components that may be subject to the longer period waves. RECOMMENDATIONS FOR FURTHER STUDY Further supplemental evaluation is needed to address several issues identified within our current evaluation. Additional evaluation should be performed at this current planning level of site design work. However, that work may take place on a broader level associated with planning levels of site design. Further detailed supplemental investigations and studies could take place after at the design level . These areas of further study are outlined below. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 25 Planning Level Studies • Determine if further exploration is needed offsite as Petra only evaluated a portion of the landslide complex previously. Perform an initial stability analysis to evaluate the landslide potential with the cut- slope as proposed. • Perform an initial offsite stability analysis for a potential shear key north of Nichols Road. This may be done for one or two cross sections to determine a range of feasible features or potential configurations for such a shear key. Further studies and or field exploration may then be needed for earthwork and shear key optimization during detailed design. • Conduct further field work with CPT soundings to evaluate liquefaction potential in the alluvial areas. Design Level • Perform final design stability analysis to determine final cut-slope stabilization measures for the portion of the landslide below Nichols Road. Further exploration specific to the shear key locations may be needed for determination of bedrock contacts and other relevant parameters for shear key design. • Perform final design stability analysis for an offsite shear key north of Nichols Road if determined feasible during planning. Like noted above further exploration specific to the shear key locations may be needed for determination of bedrock contacts and other relevant parameters for shear key design. • Conduct further onsite exploration to evaluate the swell potential and swell pressures of the onsite expansive soils, and to evaluate the likely volumes of less expansive soils that may be suitable for mitigation by selective grading. Laboratory studies could also be undertaken to evaluate the potential for soil cement mixing to reduce the expansion potential of the soils. • Conduct shear wave velocity testing and a site specific ground motion hazard analysis. FUTURE IMPROVEMENTS AND GRADING As noted herein, additional geotechnical evaluation is needed to assess liquefaction and seismic settlement potential, slope stability, and expansive soils mitigation measures. These analyses would be required prior to grading plan approval. A proposal for some of these services has been provided to the client (revised date May 17, 2023). Further revisions to those proposed scopes of work may be undertaken based on the current findings. This report has been prepared for the exclusive use of NorthPoint Development LLC to assist the project engineers and architect in the design of the proposed development. It is recommended that Petra be engaged to review the final-design drawings and specifications prior to construction. This is to document that the recommendations contained in this report have been properly interpreted and are incorporated into the project specifications. If Petra is not accorded the opportunity to review these documents, we can take no responsibility for misinterpretation of our recommendations. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 26 We recommend that Petra be retained to provide soil-engineering services during construction of the excavation and foundation phases of the work. This is to observe compliance with the design, specifications, or recommendations and to allow design changes if subsurface conditions differ from those anticipated prior to start of construction. If the project plans change significantly (e.g., building loads or type of structures), we should be retained to review our original design recommendations and their applicability to the revised construction. If conditions are encountered during construction that appear to be different than those indicated in this report, this office should be notified immediately. Design and construction revisions may be required. REPORT LIMITATIONS This report is based on the proposed project and geotechnical data as described herein . The materials encountered on the project site, described in other literature, and utilized in our laboratory evaluation are believed representative of the project area, and the conclusions and recommendations contained in this report are presented on that basis. However, soil 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, observation and testing by a geotechnical consultant during the grading and construction phases of the project 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 guarantee or warranty. This report should be reviewed and updated after a period of one year or if the project concept changes from that described herein. The information contained herein 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. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 27 This report is subject to review by the controlling authorities for this project. Should you have any questions, please do not hesitate to call. Respectfully submitted, PETRA GEOSCIENCES, INC. Edward Lump J. Montgomery Schultz Associate Geologist Chief Engineer CEG 1924 GE 2941 EL/JMS/lv DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 28 REFERENCES American Society for Testing and Materials (ASTM) – Standard – Section Four – Construction, Volume 04.08 Soil and Rock American Society of Civil Engineers (ASCE) 7 -016 Minimum Design Loads for Buildings and Other Structures. Bryant, W.A., and Hart, E.W., 2007, Fault-Rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zones Maps, California Geological Survey, Special Publication 42. California Building Code (CBC), (2022), California Code of Regulations, Title 24, Par 2, Volume 2 of 2, Based on the 2021 International Building Code, California Building Standards Commission. California Department of Water Resources, 2023, Water Data Library, http://www.water.ca.gov/waterdatalibrary/ _______, 1991, California Well Standard, Bulletin 74-90, dated June. California Geological Survey, 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in California: CGS Special Publication 117A. California Geological Survey, 2010, Fault Activity Map of California, Geologic Data Map No. 6, http://maps.conservation.ca.gov/cgs/fam/ California Geological Survey (CGS), 2023, California Earthquake Hazards Zone Application (EQ Zapp), https://www.conservation.ca.gov/cgs/geohazards/eq-zapp, searched October 2023. County of Riverside, 2014, Low Impact Development BMP Design Handbook, June. G.A. Nicholl and Associates, Inc., 1990, Geotechnical Feasibility Investigation, Alberhill Ranch Project, Alberhill – Lake Elsinore Area, Riverside County, California, Project No. B3992 -02, dated March 23. Google Earth™ 2023, by Google Earth, Inc., http://www.google.com/earth/index.html, accessed September. Office of Statewide Health Planning and Development (OSHPD), 2023, Seismic Design Maps, U.S. Seismic Design Maps (seismicmaps.org) Petra Geotechnical, Inc. (Petra), 1990, Preliminary Soils Engineering and Engineering Geologic Investigation, 107.9 Acres, Alberhill Ranch, Riverside County, California (Hoist Property), J.N. 452-89, dated February 28. _______, 2003, Geotechnical Investigation, Tentative Tract No. 28214 (Alberhill West Property), Lake Elsinore, County of Riverside, California, J.N. 158 -03, dated September 10. _______, 2005, Geotechnical Investigation, Proposed Nichols Road Alignment, Lake Elsinore, Riverside County, California; J.N. 160-04, dated September 28, 2005). _______, 2006a, Geotechnical Investigation, Amended Vesting Tentative Tract No. 30836 (Hoist Property), Lake Elsinore, County of Riverside, California, J.N. 414-03, dated March 31. , 2006b, Updated Geotechnical Recommendations, Proposed Nichols Road Realignment (Stations 46+00 through 81+00), City of Lake Elsinore, Riverside County, California, J.N. 259 -06, dated August 30. , 2006c, Geotechnical Report of Rough Grading, Nichols Road (Stations 11+50 to 55+00), City of Lake Elsinore, Riverside County, California, J.N. 259-06, dated November 6. DRAFT NORTHPOINT DEVELOPMENT, LLC November 21, 2023 W. Nichols Logistics Center / Lake Elsinore J.N. 23-195 Page 29 REFERENCES ______, 2007a, Preliminary Geotechnical Investigation, Proposed 31.6-Acre Mixed-Use Site, South of Future Nichols Road (Alberhill Ranch Development), City of Lake Elsinore, Riverside County, California, J.N. 271 -07, dated August 8. ______, 2007b, Update Geotechnical Recommendations, Proposed Nichols Road Phase 2, Stations 55+00 through 82+00, Alberhill Ranch Area, City of Lake Elsinore, Riverside County, California, J.N. 259 -06, dated November 4. ______, 2009, Preliminary Soils Engineering and Engineering Geological Investigation, 388.1 Acres, Alberhill Ranch, Riverside County, California, J.N. 452-09, dated January 11. ______, 2011, Interim Geotechnical Report of Rough Grading, Nichols Road Phase II, Approximate Sta. 30+00 to Sta. 82+50, Tract 28214 (Alberhill Ranch Project) City of Lake Elsinore, Riverside County, California, J.N. 259-06, dated March 24. Petra Geosciences, Inc., 2023, Phase I Environmental Site Assessment; West Nichols Logistics Center Project, Southeast of Nichols Road and Terra Cotta Road, Lake Elsinore, Riverside County, California 92530, J.N. 23-195, dated October 20. United States Geological Survey (USGS), 2023, The National Map Viewer. DRAFT PLATES DRAFT TD=30'Tsi@25.5'BA-1BA-2QlsQoalQoal or QpsQlsB-1HS-18HS-17TD=21.5'GW@16.5'(EL. 1259.5')Tsi@12'(EL. 1264')TP-1TP-28HS-19B-3TP-4TP-2TP-7QalQalQoalQoalB-4TP-3TP-5TP-7TD=7.5'Tsi@3'QoalB-2HS-15HS-16Private WellWellTD=60'Qls@2'Qoal@36'Tsi@45'GW@41'(EL. 1,280')TD=21.5'NW GWTsi@10'(EL.1,280')TD=6'No GWTD=6.5'No GWTD=21.5'GW@14'(EL.1,258')TD=16.5'GW@13.5'(EL. 1259.5')Tsi@10'(EL. 1263')TD=31'GW@16'(EL.1,255')Tsi@24'TD=16.5'Tsi@3'TD=26.5'Tsi@10'TD=26.5'Tsi@5'B-32TD=16.5'No GWTsi@8'(EL. 1,307)TD=7'Qoal@5'Tsi@4'TD=6'Tsi@4'TD=6.5'Qoal@1.5'TD=5'TD=4'TD=3'TD=5.5'Qps@3'P-4TD=8'P-3P-2P-1QoalQlsTsiTsiBA-1QalQalQoalTP-6B-5TP-6TP-5TD=7'Qoal@1'TD=7'Tsi@2'TP-4TD=8'Qoal@6'B-7B-6TP-11TP-9TP-3TD=8'Qoal@6'TP-2TD=8.5'Qoal@2.5'TP-10TP-27TP-1TD=7'Qoal@1'QoalHS-13HS-12HS-11TP-8HS-14TP-12??TD=16.5'No GWTsi@5'(EL.1,307)TD=62'GW@50'(EL.1,277')Qoal@29'Tsi@35'TD=21.5'No GWTsi@20'(EL.1,291')TD=21.5'NW GWTsi@5'(EL.1,289')TD=5.5'No GWTsi@5'TD=6.5'No GWTD=21.5'GW@16'(EL.1,276)Tsi@4.5'TD=26.5'Tsi@6.5'TD=5'No GWTsi@4.3'TD=16.5'No GWTD=13'No GWTD=21.5'No GWTD=9'No GWTD=5.5'No GWQls@2'B-33TD=16.5'No GWTsi@15'(EL. 1,308)TD=4.5'Qls@3'TD=5.5'Qoal@2.5'QalQalafafPETRA GEOSCIENCES, INC.40880 County Center Drive, Suite MTemecula, CA 92591PHONE: (951) 600-9271COSTA MESA TEMECULA VALENCIA PALM DESERT CORONAGeologic and Field Exploration MapNichols Road Distribution Center,Lake Elsinore, Riverside Coutnty, CaliforniaPLATE 1DATE: OCT. 2023J.N: 23-195EXPLANATION(LOCATIONS ARE APPROXIMATE)ARTIFICIAL FILL, UNDOCUMENTEDALLUVIUMOLDER ALLUVIUMQUATERNARY PAUBA FORMATIONQUATERNARY LANDSLIDE DEPOSITSTERTIARY SILVERADO FORMATIONGEOLOGIC CONTACT (QUERIED WHERE UNCERTAIN)HSA BORING LOCATION (PETRA, 2007a)BUCKET AUGER BORING (PETRA, 2007a)BORING LOCATION (PREVIOUS INVESTIGATION, PETRA 2007a)BORING LOCATION (PREVIOUS INVESTIGATION, PETRA 2007b)TEST PIT LOCATION (PETRA, 2007a)TEST PIT LOCATION (PETRA, 2003)TEST PIT LOCATION (PETRA, 2023)PERCOLATION TEST LOCATION (PETRA, 2023)afuQalQoalQpsQlsTsi?B-7BA-2HS-21BA-1TP-12TP-28TP-7DRAFT 1741 ft N ic h ols R d 1294 ft NicholsRdH o f f A v e TerraCottaRdTerraCottaRdK in g s H w y K i n g s H w y K i n g s H w y C o a lA v e Carson Ave N i c h o l s R d T e r r a C o t t a Cor onaFwyWALKERCANYON1694 ft WAL KERCANYONNicholsRdB a k er S t N i c h o ls R d Hoist Landslide Esri Community Maps Contributors, County of Riverside, California State Parks, © OpenStreetMap, Microsoft, Esri, HERE, Garmin, SafeGraph, GeoTechnologies, Inc, METI/NASA, USGS, Bureau of Land Management, EPA, NPS, US Census Bureau, USDA Esri, NASA, NGA, USGS, FEMA World Hillshade 11/4/2023 0 0.1 0.20.05 mi 0 0.2 0.40.1 km 1:7,200 3186 Airway Avenue, Suite K Costa Mesa, California 92626 PHONE: (714) 549-8921 HILLSH A DE MA P West Nichols Logistics Center, Lake Elsinore, California DATE: November, 2023 J.N.: 23-195 Figure 2a PE T R A GE O SCIE NCE S, IN C. COSTA MESA TEMECULA LOS ANGELES PALM DESERT CORONA ESCONDIDO West Nichols Logistics Center Plate DRAFT ˆIW 1LFKROV5 G ˝IW 1 L F K R O V 5 G +RII$YH 7 HUUD&RWWD5G7HUUD&RWWD5G.LQJV +Z\.LQJV +Z\ .LQJV +Z \ &R D O $Y H & D UVRQ $YH 1 LFKROV 5 G 7HUUD &RWWD &RURQD)Z\:$/.(5&$1<21ˇ˝IW :$/.(5&$1<211LFKROV5G% D N H U 6 W 1 LFK R OV 5 G +RLVW/DQGVOLGH (VUL&RPPXQLW\0DSV&RQWULEXWRUV&RXQW\RI5LYHUVLGH&DOLIRUQLD 6WDWH 3DUNV ‰ 2SHQ6WUHHW0DS 0LFURVRIW (VUL +(5( *DUPLQ 6DIH*UDSK*HR7HFKQRORJLHV,QF0(7,1$6$86*6%XUHDXRI /DQG0DQDJHPHQW(3$13686&HQVXV%XUHDX86'$ (VUL1$6$1*$86*6)(0$ :RUOG+LOOVKDGH ˘PL NP ˛ˆ 3186 Airway Avenue, Suite K Costa Mesa, California 92626 PHONE: (714) 549-8921 H I L L S HAD E M AP w/ L AN DS L I DE West Nichols Logistics Center, Lake Elsinore, California DATE: November, 2023 J.N.: 23-195 Figure 2b P ETRA G E OS C I EN C ES, I N C. COSTA MESA TEMECULA LOS ANGELES PALM DESERT CORONA ESCONDIDO Overlay Map Reference: A portion of "Geological Map prepared by G.A. Nicoll & Associates, P.N. B3991-02, dated March 1990" West Nichols Logistics Center Landslide Complex Plate DRAFT United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Western Riverside Area, CaliforniaNatural Resources Conservation Service July 18, 2024 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 Western Riverside Area, California.................................................................14 AbF—Altamont cobbly clay, 8 to 35 percent slopes....................................14 AkC—Arbuckle loam, 2 to 8 percent slopes................................................15 CkF2—Cieneba rocky sandy loam, 15 to 50 percent slopes, eroded.........16 GaA—Garretson very fine sandy loam, 0 to 2 percent slopes....................18 GaC—Garretson very fine sandy loam, 2 to 8 percent slopes....................19 GdC—Garretson gravelly very fine sandy loam, 2 to 8 percent slopes.......20 HcC—Hanford coarse sandy loam, 2 to 8 percent slopes..........................21 PlD—Placentia fine sandy loam, 5 to 15 percent slopes.............................23 RaB2—Ramona sandy loam, 2 to 5 percent slopes, eroded......................24 RaD3—Ramona sandy loam, 8 to 15 percent slopes, severely eroded......25 RuF—Rough broken land............................................................................27 Wg—Willows silty clay, saline-alkali............................................................27 References............................................................................................................29 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map 372900037291003729200372930037294003729500372960037297003729800372900037291003729200372930037294003729500372960037297003729800465100 465200 465300 465400 465500 465600 465700 465800 465900 466000 466100 466200 466300 466400 465100 465200 465300 465400 465500 465600 465700 465800 465900 466000 466100 466200 466300 466400 33° 42' 28'' N 117° 22' 37'' W33° 42' 28'' N117° 21' 42'' W33° 41' 59'' N 117° 22' 37'' W33° 41' 59'' N 117° 21' 42'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 300 600 1200 1800 Feet 0 50 100 200 300 Meters Map Scale: 1:6,460 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Western Riverside Area, California Survey Area Data: Version 16, Aug 30, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 14, 2022—Mar 17, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 10 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI AbF Altamont cobbly clay, 8 to 35 percent slopes 111.5 57.2% AkC Arbuckle loam, 2 to 8 percent slopes 6.7 3.4% CkF2 Cieneba rocky sandy loam, 15 to 50 percent slopes, eroded 1.1 0.6% GaA Garretson very fine sandy loam, 0 to 2 percent slopes 0.1 0.0% GaC Garretson very fine sandy loam, 2 to 8 percent slopes 14.6 7.5% GdC Garretson gravelly very fine sandy loam, 2 to 8 percent slopes 2.2 1.1% HcC Hanford coarse sandy loam, 2 to 8 percent slopes 11.4 5.8% PlD Placentia fine sandy loam, 5 to 15 percent slopes 14.1 7.2% RaB2 Ramona sandy loam, 2 to 5 percent slopes, eroded 9.3 4.8% RaD3 Ramona sandy loam, 8 to 15 percent slopes, severely eroded 9.0 4.6% RuF Rough broken land 0.2 0.1% Wg Willows silty clay, saline-alkali 14.9 7.6% Totals for Area of Interest 195.0 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Custom Soil Resource Report 11 Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion Custom Soil Resource Report 12 of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 13 Western Riverside Area, California AbF—Altamont cobbly clay, 8 to 35 percent slopes Map Unit Setting National map unit symbol: hcqk Elevation: 200 to 3,000 feet Mean annual precipitation: 12 to 25 inches Mean annual air temperature: 59 to 63 degrees F Frost-free period: 250 to 310 days Farmland classification: Not prime farmland Map Unit Composition Altamont and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Altamont Setting Landform:Hills Landform position (two-dimensional):Backslope Landform position (three-dimensional):Side slope Down-slope shape:Concave Across-slope shape:Convex Parent material:Residuum weathered from sedimentary rock Typical profile H1 - 0 to 18 inches: cobbly clay H2 - 18 to 23 inches: silty clay H3 - 23 to 27 inches: bedrock Properties and qualities Slope:8 to 35 percent Depth to restrictive feature:20 to 40 inches to paralithic bedrock Drainage class:Well drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:10 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: Very low (about 2.7 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: D Ecological site: R019XD001CA - CLAYEY Hydric soil rating: No Custom Soil Resource Report 14 Minor Components Soper Percent of map unit:5 percent Gaviota Percent of map unit:5 percent Unnamed Percent of map unit:3 percent Hydric soil rating: No Unnamed Percent of map unit:2 percent Hydric soil rating: No AkC—Arbuckle loam, 2 to 8 percent slopes Map Unit Setting National map unit symbol: hcqp Elevation: 100 to 1,600 feet Mean annual precipitation: 12 to 35 inches Mean annual air temperature: 57 to 64 degrees F Frost-free period: 200 to 280 days Farmland classification: Prime farmland if irrigated Map Unit Composition Arbuckle and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Arbuckle Setting Landform:Alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium derived from metasedimentary rock Typical profile H1 - 0 to 12 inches: loam H2 - 12 to 26 inches: loam H3 - 26 to 45 inches: gravelly loam H4 - 45 to 68 inches: stratified sandy loam to very gravelly sandy clay loam Properties and qualities Slope:2 to 8 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: High Custom Soil Resource Report 15 Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.57 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Moderate (about 7.5 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: R019XD029CA - LOAMY Hydric soil rating: No Minor Components Garretson Percent of map unit:5 percent Hydric soil rating: No Cortina Percent of map unit:5 percent Hydric soil rating: No Perkins Percent of map unit:5 percent Hydric soil rating: No CkF2—Cieneba rocky sandy loam, 15 to 50 percent slopes, eroded Map Unit Setting National map unit symbol: hcsf Elevation: 500 to 4,000 feet Mean annual precipitation: 12 to 35 inches Mean annual air temperature: 57 to 64 degrees F Frost-free period: 200 to 300 days Farmland classification: Not prime farmland Map Unit Composition Cieneba and similar soils:75 percent Minor components:25 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Cieneba Setting Landform:Hills Landform position (two-dimensional):Backslope Landform position (three-dimensional):Side slope Down-slope shape:Concave Across-slope shape:Convex Custom Soil Resource Report 16 Parent material:Residuum weathered from igneous rock Typical profile H1 - 0 to 14 inches: sandy loam H2 - 14 to 22 inches: weathered bedrock Properties and qualities Slope:15 to 50 percent Depth to restrictive feature:14 to 22 inches to paralithic bedrock Drainage class:Somewhat excessively drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat):Very low to moderately low (0.00 to 0.06 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Very low (about 1.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 7e Hydrologic Soil Group: D Ecological site: R019XD060CA - SHALLOW LOAMY Hydric soil rating: No Minor Components Rock outcrop Percent of map unit:10 percent Hydric soil rating: No Vista Percent of map unit:3 percent Hydric soil rating: No Fallbrook Percent of map unit:3 percent Hydric soil rating: No Unnamed Percent of map unit:3 percent Hydric soil rating: No Friant Percent of map unit:3 percent Hydric soil rating: No Escondido Percent of map unit:3 percent Hydric soil rating: No Custom Soil Resource Report 17 GaA—Garretson very fine sandy loam, 0 to 2 percent slopes Map Unit Setting National map unit symbol: hcv1 Elevation: 490 to 1,480 feet Mean annual precipitation: 12 to 25 inches Mean annual air temperature: 61 to 64 degrees F Frost-free period: 220 to 280 days Farmland classification: Prime farmland if irrigated Map Unit Composition Garretson and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Garretson Setting Landform:Alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium derived from metasedimentary rock Typical profile H1 - 0 to 10 inches: very fine sandy loam H2 - 10 to 60 inches: loam Properties and qualities Slope:0 to 2 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.57 to 1.98 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Moderate (about 9.0 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 3c Hydrologic Soil Group: B Ecological site: R019XD029CA - LOAMY Hydric soil rating: No Custom Soil Resource Report 18 Minor Components Perkins Percent of map unit:5 percent Hydric soil rating: No Cortina Percent of map unit:5 percent Hydric soil rating: No Arbuckle Percent of map unit:5 percent Hydric soil rating: No GaC—Garretson very fine sandy loam, 2 to 8 percent slopes Map Unit Setting National map unit symbol: hcv2 Elevation: 430 to 1,740 feet Mean annual precipitation: 12 to 25 inches Mean annual air temperature: 61 to 64 degrees F Frost-free period: 220 to 280 days Farmland classification: Prime farmland if irrigated Map Unit Composition Garretson and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Garretson Setting Landform:Alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium derived from metasedimentary rock Typical profile H1 - 0 to 10 inches: very fine sandy loam H2 - 10 to 60 inches: loam Properties and qualities Slope:2 to 8 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.57 to 1.98 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Custom Soil Resource Report 19 Frequency of ponding:None Available water supply, 0 to 60 inches: Moderate (about 9.0 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: R019XD029CA - LOAMY Hydric soil rating: No Minor Components Arbuckle Percent of map unit:5 percent Hydric soil rating: No Cortina Percent of map unit:5 percent Hydric soil rating: No Perkins Percent of map unit:5 percent Hydric soil rating: No GdC—Garretson gravelly very fine sandy loam, 2 to 8 percent slopes Map Unit Setting National map unit symbol: hcv5 Elevation: 50 to 3,000 feet Mean annual precipitation: 12 to 25 inches Mean annual air temperature: 61 to 64 degrees F Frost-free period: 250 to 350 days Farmland classification: Prime farmland if irrigated Map Unit Composition Garretson and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Garretson Setting Landform:Alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium derived from metasedimentary rock Typical profile H1 - 0 to 10 inches: gravelly very fine sandy loam H2 - 10 to 53 inches: gravelly loam H3 - 53 to 72 inches: loam Custom Soil Resource Report 20 Properties and qualities Slope:2 to 8 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.57 to 1.98 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Moderate (about 7.4 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: R019XD029CA - LOAMY Hydric soil rating: No Minor Components Arbuckle Percent of map unit:5 percent Hydric soil rating: No Cortina Percent of map unit:5 percent Hydric soil rating: No Perkins Percent of map unit:5 percent Hydric soil rating: No HcC—Hanford coarse sandy loam, 2 to 8 percent slopes Map Unit Setting National map unit symbol: 2y8tk Elevation: 680 to 2,930 feet Mean annual precipitation: 9 to 17 inches Mean annual air temperature: 63 to 65 degrees F Frost-free period: 290 to 365 days Farmland classification: Prime farmland if irrigated Map Unit Composition Hanford and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 21 Description of Hanford Setting Landform:Alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium derived from granite Typical profile A - 0 to 8 inches: coarse sandy loam C1 - 8 to 40 inches: fine sandy loam C2 - 40 to 60 inches: stratified loamy sand to coarse sandy loam Properties and qualities Slope:2 to 8 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat):High (1.98 to 5.95 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: Moderate (about 7.0 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: A Ecological site: R019XD012CA - SANDY Hydric soil rating: No Minor Components Ramona Percent of map unit:5 percent Landform:Alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Hydric soil rating: No Greenfield Percent of map unit:5 percent Landform:Alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Hydric soil rating: No Tujunga Percent of map unit:2 percent Landform:Alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Custom Soil Resource Report 22 Across-slope shape:Linear Hydric soil rating: No Unnamed Percent of map unit:2 percent Hydric soil rating: No Unnamed Percent of map unit:1 percent Hydric soil rating: No PlD—Placentia fine sandy loam, 5 to 15 percent slopes Map Unit Setting National map unit symbol: hcxw Elevation: 50 to 2,500 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 61 to 64 degrees F Frost-free period: 200 to 300 days Farmland classification: Not prime farmland Map Unit Composition Placentia and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Placentia Setting Landform:Terraces, alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium derived from granite Typical profile H1 - 0 to 18 inches: fine sandy loam H2 - 18 to 39 inches: clay H3 - 39 to 57 inches: clay loam H4 - 57 to 60 inches: gravelly sandy loam Properties and qualities Slope:5 to 15 percent Depth to restrictive feature:More than 80 inches Drainage class:Moderately well drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat):Very low to moderately low (0.00 to 0.06 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Custom Soil Resource Report 23 Calcium carbonate, maximum content:5 percent Maximum salinity:Very slightly saline to moderately saline (2.0 to 8.0 mmhos/cm) Sodium adsorption ratio, maximum:50.0 Available water supply, 0 to 60 inches: Low (about 4.8 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: D Ecological site: R019XD061CA - CLAYPAN Hydric soil rating: No Minor Components Greenfield Percent of map unit:5 percent Hydric soil rating: No Hanford Percent of map unit:5 percent Hydric soil rating: No Ramona Percent of map unit:4 percent Hydric soil rating: No Unnamed, ponded Percent of map unit:1 percent Landform:Depressions Hydric soil rating: Yes RaB2—Ramona sandy loam, 2 to 5 percent slopes, eroded Map Unit Setting National map unit symbol: hcy5 Elevation: 250 to 3,500 feet Mean annual precipitation: 10 to 20 inches Mean annual air temperature: 63 degrees F Frost-free period: 230 to 320 days Farmland classification: Prime farmland if irrigated Map Unit Composition Ramona and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ramona Setting Landform:Terraces, alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear Custom Soil Resource Report 24 Across-slope shape:Linear Parent material:Alluvium derived from granite Typical profile H1 - 0 to 14 inches: sandy loam H2 - 14 to 23 inches: fine sandy loam H3 - 23 to 68 inches: sandy clay loam H4 - 68 to 74 inches: gravelly sandy loam Properties and qualities Slope:2 to 5 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.57 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:1 percent Available water supply, 0 to 60 inches: Moderate (about 8.1 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: R019XD029CA - LOAMY Hydric soil rating: No Minor Components Greenfield Percent of map unit:4 percent Hydric soil rating: No Arlington Percent of map unit:4 percent Hydric soil rating: No Hanford Percent of map unit:4 percent Hydric soil rating: No Tujunga Percent of map unit:3 percent Hydric soil rating: No RaD3—Ramona sandy loam, 8 to 15 percent slopes, severely eroded Map Unit Setting National map unit symbol: hcyb Elevation: 250 to 3,500 feet Custom Soil Resource Report 25 Mean annual precipitation: 10 to 20 inches Mean annual air temperature: 63 degrees F Frost-free period: 230 to 320 days Farmland classification: Not prime farmland Map Unit Composition Ramona and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ramona Setting Landform:Terraces, alluvial fans Landform position (three-dimensional):Tread Down-slope shape:Linear, concave Across-slope shape:Linear Parent material:Alluvium derived from granite Typical profile H1 - 0 to 8 inches: sandy loam H2 - 8 to 17 inches: fine sandy loam H3 - 17 to 68 inches: sandy clay loam H4 - 68 to 74 inches: gravelly sandy loam Properties and qualities Slope:8 to 15 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.57 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:1 percent Available water supply, 0 to 60 inches: Moderate (about 8.4 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: R019XD029CA - LOAMY Hydric soil rating: No Minor Components Greenfield Percent of map unit:5 percent Hydric soil rating: No Hanford Percent of map unit:5 percent Hydric soil rating: No Tujunga Percent of map unit:5 percent Hydric soil rating: No Custom Soil Resource Report 26 RuF—Rough broken land Map Unit Composition Rough broken land:100 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Rough Broken Land Setting Down-slope shape:Concave Across-slope shape:Convex Parent material:Residuum derived from mixed sources Typical profile H1 - 0 to 60 inches: unweathered bedrock Properties and qualities Slope:30 to 50 percent Depth to restrictive feature:0 to 3 inches to paralithic bedrock Runoff class: Very high Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8 Hydric soil rating: No Wg—Willows silty clay, saline-alkali Map Unit Setting National map unit symbol: hd08 Elevation: 0 to 1,700 feet Mean annual precipitation: 19 inches Mean annual air temperature: 61 degrees F Frost-free period: 210 to 250 days Farmland classification: Farmland of statewide importance Map Unit Composition Willows and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Willows Setting Landform:Basin floors Landform position (three-dimensional):Talf Down-slope shape:Linear Across-slope shape:Linear Custom Soil Resource Report 27 Parent material:Alluvium derived from mixed sources Typical profile H1 - 0 to 10 inches: silty clay H2 - 10 to 60 inches: clay Properties and qualities Slope:0 to 2 percent Depth to restrictive feature:More than 80 inches Drainage class:Poorly drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat):Very low to moderately low (0.00 to 0.06 in/hr) Depth to water table:About 0 inches Frequency of flooding:Rare Frequency of ponding:None Calcium carbonate, maximum content:5 percent Maximum salinity:Slightly saline to strongly saline (4.0 to 16.0 mmhos/cm) Sodium adsorption ratio, maximum:2.0 Available water supply, 0 to 60 inches: Low (about 5.1 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 4w Hydrologic Soil Group: D Ecological site: R019XD068CA - SILTY BASIN Hydric soil rating: No Minor Components Domino Percent of map unit:5 percent Hydric soil rating: No Chino Percent of map unit:5 percent Hydric soil rating: No Madera Percent of map unit:5 percent Hydric soil rating: No Custom Soil Resource Report 28 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 29 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 30 - 32 - Appendix 4: Historical Site Conditions Phase I Environmental Site Assessment or Other Information on Past Site Use - 33 - Appendix 5: LID Infeasibility LID Technical Infeasibility Analysis - 34 - Appendix 6: BMP Design Details BMP Sizing, Design Details and other Supporting Documentation RIVERSIDE COUNTY FLOODCONTROL AND WATERCONSERVATION DISTRICTIsohyetal Mapfor the 85th Percentile24 hour Storm EventJuly 2011Rain Gage Locations Date D85=0.72 inches DMA Type/ID DMA Area (square feet) Post-Project Surface Type Effective Imperivous Fraction, If DMA Runoff Factor DMA Areas x Runoff Factor Design Storm Depth (in) Design Capture Volume, VBMP (cubic feet) Proposed Volume on Plans (cubic feet) B 95647 Concrete or Asphalt 1 0.89 85317.1 B 162735 Ornamental Landscaping 0.1 0.11 17975.4 B 78423 Roofs 1 0.89 69953.3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 336805 173245.8 0.72 10394.7 12243 Notes: Total 85th Percentile, 24-hour Rainfall Depth, from the Isohyetal Map in Handbook Appendix E Insert additional rows if needed to accommodate all DMAs draining to the BMP Santa Ana Watershed - BMP Design Volume, VBMP (Rev. 10-2011) Legend:Required Entries Calculated Cells (Note this worksheet shall only be used in conjunction with BMP designs from the LID BMP Design Handbook ) Company Name KWC ENGINEERS 7/18/2023 Designed by Daniella Ginocchio Case No Company Project Number/Name Stockdale Industrial BMP Identification Drainage Management Area Tabulation Design Rainfall Depth BMP NAME / ID Basin A Must match Name/ID used on BMP Design Calculation Sheet WQMP BMP SIZING -Bioretention Facility BASIN A DATE OF LATEST REVISION: 7/26/2024 BASIN BMP Design Volume Required Vbmp1 Basin Top Area Basin Bottom Area Basin Average Area Basin Depth Media Volume Provided Basin Volume Provided Total Basin Volume Provided Total Basin Volume Provided (cu-ft)(s.f.)(s.f.)(s.f.)(ft)(cu.ft)(cu.ft)(cu.ft)(ac-ft) BASIN A 10,395 6,900 6,192 6,546 0.5 8,970 3,273 12,243 0.28 Assume Media: 36" sand filter media (30% void spacing) over 24" of gravel (40% void spacing) Note: 1)See BMP Design Volume Worksheet for Vbmp calculations. Bioretention Facility Design:(4:1 Side Slope) Tributary Area, AT=337,200 sf Design Volume, VBMP=10,395 cf Depth of Eng. Soil, dS=3 ft Depth of Ponding, dP=0.5 ft Top Width, WT=60 ft Total Effective Depth, dE=1.79 ft (note: calculated using LID Bioretention Facility design equation) Min. Surface Area Req'd, AM=5,813 sf (note: calculated using LID Bioretention Facility design equation) Min. Surface Area Provided=6,900 sf (greater than required, okay) R:\24\2425\PRELIM\REPORTS\PRELIM WQMP\Appendix 6- BMP Design Details\DMA A- WQMP BMPs Treatment Sizing Date D85=0.72 inches DMA Type/ID DMA Area (square feet) Post-Project Surface Type Effective Imperivous Fraction, If DMA Runoff Factor DMA Areas x Runoff Factor Design Storm Depth (in) Design Capture Volume, VBMP (cubic feet) Proposed Volume on Plans (cubic feet) A 298772 Ornamental Landscaping 0.1 0.11 33001.8 A 964947 Roofs 1 0.89 860732.7 A 795418 Concrete or Asphalt 1 0.89 709512.9 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2059137 1603247.4 0.72 96194.8 101170 Notes: Total 85th Percentile, 24-hour Rainfall Depth, from the Isohyetal Map in Handbook Appendix E Insert additional rows if needed to accommodate all DMAs draining to the BMP Santa Ana Watershed - BMP Design Volume, VBMP (Rev. 10-2011) Legend:Required Entries Calculated Cells (Note this worksheet shall only be used in conjunction with BMP designs from the LID BMP Design Handbook ) Company Name KWC ENGINEERS 7/18/2024 Designed by Daniella Ginocchio Case No Company Project Number/Name Stockdale Industrial BMP Identification Drainage Management Area Tabulation Design Rainfall Depth BMP NAME / ID Basin B Must match Name/ID used on BMP Design Calculation Sheet WQMP BMP SIZING -Bioretention Facility BASIN B DATE OF LATEST REVISION: 7/26/2024 BASIN BMP Design Volume Required Vbmp1 Basin Top Area Basin Bottom Area Basin Average Area Basin Depth Media Volume Provided Basin Volume Provided Total Basin Volume Provided Total Basin Volume Provided (cu-ft)(s.f.)(s.f.)(s.f.)(ft)(cu.ft)(cu.ft)(cu.ft)(ac-ft) BASIN A 96,195 38,051 34,916 36,484 1 64,687 36,484 101,170 2.32 Assume Media: 36" sand filter media (30% void spacing) over 12" of gravel (40% void spacing) Note: 1)See BMP Design Volume Worksheet for Vbmp calculations. Bioretention Facility Design:(4:1 Side Slope) Tributary Area, AT=2,078,627 sf Design Volume, VBMP=96,195 cf Depth of Eng. Soil, dS=3 ft Depth of Ponding, dP=1 ft Top Width, WT=207 ft Total Effective Depth, dE=2.29 ft (note: calculated using LID Bioretention Facility design equation) Min. Surface Area Req'd, AM=42,071 sf (note: calculated using LID Bioretention Facility design equation) Min. Surface Area Provided=38,051 sf (greater than required, okay) R:\24\2425\PRELIM\REPORTS\PRELIM WQMP\Appendix 6- BMP Design Details\DMA B- WQMP BMPs Treatment Sizing - 35 - Appendix 7: Hydromodification Supporting Detail Relating to Hydrologic Conditions of Concern - 36 - Appendix 8: Source Control Pollutant Sources/Source Control Checklist S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T How to use this worksheet (also see instructions in Section G of the WQMP Template): 1. Review Column 1 and identify which of these potential sources of stormwater pollutants apply to your site. Check each box that applies. 2. Review Column 2 and incorporate all of the corresponding applicable BMPs in your WQMP Exhibit. 3. Review Columns 3 and 4 and incorporate all of the corresponding applicable permanent controls and operational BMPs in your WQMP. Use the format shown in Table G.1on page 23 of this WQMP Template. Describe your specific BMPs in an accompanying narrative, and explain any special conditions or situations that required omitting BMPs or substituting alternative BMPs for those shown here. IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  A. On-site storm drain inlets  Locations of inlets.  Mark all inlets with the words “Only Rain Down the Storm Drain” or similar. Catch Basin Markers may be available from the Riverside County Flood Control and Water Conservation District, call 951.955.1200 to verify.  Maintain and periodically repaint or replace inlet markings.  Provide stormwater pollution prevention information to new site owners, lessees, or operators.  See applicable operational BMPs in Fact Sheet SC-44, “Drainage System Maintenance,” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.com  Include the following in lease agreements: “Tenant shall not allow anyone to discharge anything to storm drains or to store or deposit materials so as to create a potential discharge to storm drains.”  B. Interior floor drains and elevator shaft sump pumps  State that interior floor drains and elevator shaft sump pumps will be plumbed to sanitary sewer.  Inspect and maintain drains to prevent blockages and overflow.  C. Interior parking garages  State that parking garage floor drains will be plumbed to the sanitary sewer.  Inspect and maintain drains to prevent blockages and overflow. S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  D1. Need for future indoor & structural pest control  Note building design features that discourage entry of pests.  Provide Integrated Pest Management information to owners, lessees, and operators.  D2. Landscape/ Outdoor Pesticide Use  Show locations of native trees or areas of shrubs and ground cover to be undisturbed and retained.  Show self-retaining landscape areas, if any.  Show stormwater treatment and hydrograph modification management BMPs. (See instructions in Chapter 3, Step 5 and guidance in Chapter 5.) State that final landscape plans will accomplish all of the following.  Preserve existing native trees, shrubs, and ground cover to the maximum extent possible.  Design landscaping to minimize irrigation and runoff, to promote surface infiltration where appropriate, and to minimize the use of fertilizers and pesticides that can contribute to stormwater  pollution. Where landscaped areas are used to retain or detain stormwater, specify plants that are tolerant of saturated  soil conditions. Consider using pest-resistant  plants, especially adjacent to hardscape. To insure successful establishment, select plants appropriate to site soils, slopes, climate, sun, wind, rain, land use, air movement, ecological consistency, and plant interactions.  Maintain landscaping using minimum or no pesticides.  See applicable operational BMPs in “What you should know for…..Landscape and Gardening” at http://rcflood.org/stormwater/Error! Hyperlink reference not valid. Provide IPM information to new  owners, lessees and operators. S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  E. Pools, spas, ponds, decorative fountains, and other water features.  Show location of water feature and a sanitary sewer cleanout in an accessible area within 10 feet. (Exception: Public pools must be plumbed according to County Department of Environmental Health Guidelines.) If the Co-Permittee requires pools to be plumbed to the sanitary sewer, place a note on the plans and state in the narrative that this connection will be made according to local requirements.  See applicable operational BMPs in “Guidelines for Maintaining Your Swimming Pool, Jacuzzi and Garden Fountain” at http://rcflood.org/stormwater/  F. Food service  For restaurants, grocery stores, and other food service operations, show location (indoors or in a covered area outdoors) of a floor sink or other area for cleaning floor mats, containers, and equipment.  On the drawing, show a note that this drain will be connected to a grease interceptor before discharging to the sanitary sewer.  Describe the location and features of the designated cleaning area.  Describe the items to be cleaned in this facility and how it has been sized to insure that the largest items can be accommodated.  See the brochure, “The Food Service Industry Best Management Practices for: Restaurants, Grocery Stores, Delicatessens and Bakeries” at http://rcflood.org/stormwater/ Provide this brochure to new site owners, lessees, and operators.  G. Refuse areas  Show where site refuse and recycled materials will be handled and stored for pickup. See local municipal requirements for sizes and other details of refuse areas.  If dumpsters or other receptacles are outdoors, show how the designated area will be covered, graded, and paved to prevent run- on and show locations of berms to prevent runoff from the area.  Any drains from dumpsters, compactors, and tallow bin areas shall be connected to a grease removal device before discharge to sanitary sewer.  State how site refuse will be handled and provide supporting detail to what is shown on plans.  State that signs will be posted on or near dumpsters with the words “Do not dump hazardous materials here” or similar.  State how the following will be implemented: Provide adequate number of receptacles. Inspect receptacles regularly; repair or replace leaky receptacles. Keep receptacles covered. Prohibit/prevent dumping of liquid or hazardous wastes. Post “no hazardous materials” signs. Inspect and pick up litter daily and clean up spills immediately. Keep spill control materials available on-site. See Fact Sheet SC-34, “Waste Handling and Disposal” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.com S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  H. Industrial processes.  Show process area.  If industrial processes are to be located on site, state: “All process activities to be performed indoors. No processes to drain to exterior or to storm drain system.”  See Fact Sheet SC-10, “Non- Stormwater Discharges” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.com See the brochure “Industrial & Commercial Facilities Best Management Practices for: Industrial, Commercial Facilities” at http://rcflood.org/stormwater/ S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  I. Outdoor storage of equipment or materials. (See rows J and K for source control measures for vehicle cleaning, repair, and maintenance.)  Show any outdoor storage areas, including how materials will be covered. Show how areas will be graded and bermed to prevent run- on or run-off from area.  Storage of non-hazardous liquids shall be covered by a roof and/or drain to the sanitary sewer system, and be contained by berms, dikes, liners, or vaults.  Storage of hazardous materials and wastes must be in compliance with the local hazardous materials ordinance and a Hazardous Materials Management Plan for the site. Include a detailed description of materials to be stored, storage areas, and structural features to prevent pollutants from entering storm drains. Where appropriate, reference documentation of compliance with the requirements of Hazardous Materials Programs for:  Hazardous Waste Generation  Hazardous Materials Release Response and Inventory  California Accidental Release (CalARP)  Aboveground Storage Tank  See the Fact Sheets SC-31, “Outdoor Liquid Container Storage” and SC-33, “Outdoor Storage of Raw Materials ” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.com  Uniform Fire Code Article 80 Section 103(b) & (c) 1991  Underground Storage Tank www.cchealth.org/groups/hazmat / S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  J. Vehicle and Equipment Cleaning  Show on drawings as appropriate: (1) Commercial/industrial facilities having vehicle/equipment cleaning needs shall either provide a covered, bermed area for washing activities or discourage vehicle/equipment washing by removing hose bibs and installing signs prohibiting such uses. (2) Multi-dwelling complexes shall have a paved, bermed, and covered car wash area (unless car washing is prohibited on-site and hoses are provided with an automatic shut- off to discourage such use). (3) Washing areas for cars, vehicles, and equipment shall be paved, designed to prevent run-on to or runoff from the area, and plumbed to drain to the sanitary sewer. (4) Commercial car wash facilities shall be designed such that no runoff from the facility is discharged to the storm drain system. Wastewater from the facility shall discharge to the sanitary sewer, or a wastewater reclamation system shall be installed.  If a car wash area is not provided, describe any measures taken to discourage on-site car washing and explain how these will be enforced. Describe operational measures to implement the following (if applicable):  Washwater from vehicle and equipment washing operations shall not be discharged to the storm drain system. Refer to “Outdoor Cleaning Activities and Professional Mobile Service Providers” for many of the Potential Sources of Runoff Pollutants categories below. Brochure can be found at http://rcflood.org/stormwater/  Car dealerships and similar may rinse cars with water only. S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  K. Vehicle/Equipment Repair and Maintenance  Accommodate all vehicle equipment repair and maintenance indoors. Or designate an outdoor work area and design the area to prevent run-on and runoff of stormwater.  Show secondary containment for exterior work areas where motor oil, brake fluid, gasoline, diesel fuel, radiator fluid, acid-containing batteries or other hazardous materials or hazardous wastes are used or stored. Drains shall not be installed within the secondary containment areas.  Add a note on the plans that states either (1) there are no floor drains, or (2) floor drains are connected to wastewater pretreatment systems prior to discharge to the sanitary sewer and an industrial waste discharge permit will be obtained.  State that no vehicle repair or maintenance will be done outdoors, or else describe the required features of the outdoor work area.  State that there are no floor drains or if there are floor drains, note the agency from which an industrial waste discharge permit will be obtained and that the design meets that agency’s requirements.  State that there are no tanks, containers or sinks to be used for parts cleaning or rinsing or, if there are, note the agency from which an industrial waste discharge permit will be obtained and that the design meets that agency’s requirements. In the Stormwater Control Plan, note that all of the following restrictions apply to use the site:  No person shall dispose of, nor permit the disposal, directly or indirectly of vehicle fluids, hazardous materials, or rinsewater from parts cleaning into storm drains.  No vehicle fluid removal shall be performed outside a building, nor on asphalt or ground surfaces, whether inside or outside a building, except in such a manner as to ensure that any spilled fluid will be in an area of secondary containment. Leaking vehicle fluids shall be contained or drained from the vehicle immediately. No person shall leave unattended drip  parts or other open containers containing vehicle fluid, unless such containers are in use or in an area of secondary containment. Refer to “Automotive Maintenance & Car Care Best Management Practices for Auto Body Shops, Auto Repair Shops, Car Dealerships, Gas Stations and Fleet Service Operations”. Brochure can be found at http://rcflood.org/stormwater/ Refer to Outdoor Cleaning Activities and Professional Mobile Service Providers for many of the Potential Sources of Runoff Pollutants categories below. Brochure can be found at http://rcflood.org/stormwater/ S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  L. Fuel Dispensing Areas  Fueling areas6 shall have impermeable floors (i.e., portland cement concrete or equivalent smooth impervious surface) that are: a) graded at the minimum slope necessary to prevent ponding; and b) separated from the rest of the site by a grade break that prevents run-on of stormwater to the maximum extent practicable.  Fueling areas shall be covered by a canopy that extends a minimum of ten feet in each direction from each pump. [Alternative: The fueling area must be covered and the cover’s minimum dimensions must be equal to or greater than the area within the grade break or fuel dispensing area1.] The canopy [or cover] shall not drain onto the fueling area.  The property owner shall dry sweep the fueling area routinely.  See the Fact Sheet SD-30 , “Fueling Areas” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.com 6 The fueling area shall be defined as the area extending a minimum of 6.5 feet from the corner of each fuel dispenser or the length at which the hose and nozzle assembly may be operated plus a minimum of one foot, whichever is greater. S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  M. Loading Docks  Show a preliminary design for the loading dock area, including roofing and drainage. Loading docks shall be covered and/or graded to minimize run-on to and runoff from the loading area. Roof downspouts shall be positioned to direct stormwater away from the loading area. Water from loading dock areas shall be drained to the sanitary sewer, or diverted and collected for ultimate discharge to the sanitary sewer.  Loading dock areas draining directly to the sanitary sewer shall be equipped with a spill control valve or equivalent device, which shall be kept closed during periods of operation.  Provide a roof overhang over the loading area or install door skirts (cowling) at each bay that enclose the end of the trailer.  Move loaded and unloaded items indoors as soon as possible.  See Fact Sheet SC-30, “Outdoor Loading and Unloading,” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.com S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  N. Fire Sprinkler Test Water  Provide a means to drain fire sprinkler test water to the sanitary sewer.  See the note in Fact Sheet SC-41, “Building and Grounds Maintenance,” in the CASQA Stormwater Quality Handbooks at www.cabmphandbooks.com O. Miscellaneous Drain or Wash Water or Other Sources  Boiler drain lines  Condensate drain lines  Rooftop equipment  Drainage sumps  Roofing, gutters, and trim.  Other sources  Boiler drain lines shall be directly or indirectly connected to the sanitary sewer system and may not discharge to the storm drain  system. Condensate drain lines may discharge to landscaped areas if the flow is small enough that runoff will not occur. Condensate drain  lines may not discharge to the storm drain system. Rooftop equipment with potential to produce pollutants shall be  roofed and/or have secondary containment. Any drainage sumps on-site shall  feature a sediment sump to reduce the quantity of sediment in pumped water.  Avoid roofing, gutters, and trim made of copper or other unprotected metals that may leach into runoff. Include controls for other sources as specified by local reviewer. S T O R M W A T E R P O L L U T A NT S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T IF THESE SOURCES WILL BE ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of Runoff Pollutants 2 Permanent Controls—Show on WQMP Drawings 3 Permanent Controls—List in WQMP Table and Narrative 4 Operational BMPs—Include in WQMP Table and Narrative  P. Plazas, sidewalks, and parking lots.  Sweep plazas, sidewalks, and parking lots regularly to prevent accumulation of litter and debris. Collect debris from pressure washing to prevent entry into the storm drain system. Collect washwater containing any cleaning agent or degreaser and discharge to the sanitary sewer not to a storm drain. - 37 - Appendix 9: O&M Operation and Maintenance Plan and Documentation of Finance, Maintenance and Recording Mechanisms To be provided in the Final WQMP Report - 6 - Appendix 10: Educational Materials BMP Fact Sheets, Maintenance Guidelines and Other End-User BMP Information This Technical Assistance Memo (TAM) provides plant guidance for bioretention stormwater control measures. Bioretention systems are low impact development (LID) features that use a combination of soil, plants, and other design elements to slow, treat, retain, and infiltrate stormwater runoff to mimic the natural, pre-development hydrology of a site. While bioretention systems may look like regular landscaped areas, they are designed (engineered) to manage stormwater runoff volumes and pollutants created by urbanization. Specifying the appropriate plants and soil for a bioretention system is critical to its performance and community acceptance. Technical Assistance Memo (TAM) Central California Coast Low Impact Development Source: CannonLID Plant Guidance for Bioretention Which Bioretention Facility Type? There are two basic bioretention design types: planter and slope-sided. The flat-bottom planter type has a level soil surface, which allows stormwater to pond across the entire area. All plants in the planter type of bioretention must be able to tolerate stormwater inundation (Figure 1, Zone A). In comparison, the slope-sided type has two landscape conditions: the area that functions for stormwater management (Figure 2, Zone A) and the area above the ponding level. Similar to the planter type, plants in Zone A of a slope-sided bioretention type must be able to survive periodic ponding conditions. Plants in Zone B, however, are not located in the stormwater management area and the plants/trees can be selected from conventional plant palettes. For each project, it is important that the landscape designer understand where the delineation between Zone A and Zone Be occurs in order to develop a proper plant design. Slope-sided: This facility type has a lower area that ponds and conventional landscape on the side-slopes. Only plants in the functional, ponding area (Zone A) must be tolerant of periodic inundation. Flat-bottom Planter: This design type has a flat surface with consistent depth of ponding across the structure. The entire area functions for stormwater management and all plants in this facility must be tolerant of periodic inundation (Zone A). Source: Kevin Robert PerryZone A Entire Facility Functions for Stormwater Management Planting 6’-0” Min. 4:1 Sideslope typical 4:1 Sideslope typical Zone B Zone BZone A Planting Functions for Stormwater Management Conventional Landscape Conventional Landscape Figure 1 Figure 2 With the bioretention facility type known and ponding areas identified, the plants can be selected. A list of plants appropriate for Zone A conditions (periodic ponding) is available on the Central Coast Low Impact Development Initiative (LIDI) website. Choosing the Plants Source: Las Pilitas Nurserycentralcoastlidi.org/plants Plant Selection and Maintenance: Anticipating the level of maintenance a facility will receive informs plant selection and may improve long-term system function. Where irrigation levels and maintenance are expected to be low, select a tough plant palette using species with similar requirements. For example, on a road-side bioretention swale that will receive little or no irrigation and minimal maintenance after establishment, a planting of Juncus patens, Achillea millefolium and Muhlenbergia rigens could survive on rainfall once established. These tough plants, which look best when given supplemental water and cut back annually, will also tolerate mowing. The LIDI Bioretention plant list was developed using the following criteria: Source: William CullinaBioretention Workhorse: Juncus is a genus of plants, commonly known as rushes. They are found across the globe and frequently on bioretention plant lists because of their tolerance for inundation. Some Juncus perform better than others in arid environments. Juncus patens is an easy to grow California native rush. It tolerates poor drainage, flooding, drought, and shade. A strong bioretention performer, it is more drought tolerant than the commonly available Juncus effusus. Additional Juncus cultivars and varieties may also be available at nurseries. Ask growers which Juncus will perform well with both seasonal inundation and drought. The bioretention plants provided on the LIDI website represent a basic bioretention plant palette. When selecting plants, the landscape designer should determine whether a plant species is appropriate for the site considering proximity to cars, pedestrians, height limits, and anticipated levels of maintenance. Drought tolerant native plants are strongly encouraged to support water conservation, provide wildlife habitat, and for their ability to survive in local climate conditions. While plant selection for Zone B areas is at the discretion of the landscape designer, selection should take into account the sandy, free draining bioretention soil mix and the potentially erosive conditions where stormwater enters the facility. About Plant Substitutions Selection of different plant species may be appropriate based on the specific project objectives. However, the designer must ensure that plants selected for the Zone A location of a bioretention facility can tolerate periodic stormwater inundation. During construction, designers and/or construction managers should carefully review substitution requests. In the case of substitutions sought due to supplier availability, the contractor may need to broaden their search to locate a different supplier. • Tolerant of varied moisture conditions (wet and dry) • Tolerant of varied soil types and growing conditions • Low maintenance requirements • Not invasive weeds • Do not have aggressive/invasive root systems • Exhibit an attractive appearance. 2% TREES PLANTED ON SIDE SLOPES ALIGNED BETWEEN STALLS (select appropriate species for conditions) 3 1 maximum sideslope 2% A portion of stall length requirement may be accommodated in overhang of bioretention area. Specifying the correct soils for bioretention areas is critical in order to achieve stormwater objectives and plant health. Soils must balance three primary design objectives: Soils for Bioretention Landscape installation for bioretention areas is similar to that of traditional landscapes with a few added considerations: Plant Installation Trees provide additional aesthetic and performance benefits. Following these guidelines will maximize their success in bioretention areas: • Provide sufficient facility width (a rule of thumb is 8’ min.) • Trees should be located at least five feet from facility inlets to avoid erosion of soils around the root ball • Select trees that will tolerate seasonally wet soils and potential ponding • Typically, locate trees on side-slopes; not at the bottom of Zone A • Some trees may tolerate periodic shallow ponding, especially if native soils are highly infiltrative • Do not specify trees with invasive roots • Securely stake trees planted in bioretention areas Trees in Bioretention Areas Bioretention Soil Mix: Construction documents for any LID project should include a bioretention soil specification that defines the ratio of materials in the mix (approximately 35% aged compost to 65% concrete sand), and the gradation, quality analysis, and other requirements for the materials. Specifications should also include guidelines for blending and placement of the bioretention soil mix. • High enough infiltration rates to meet surface water draw down requirements • Infiltration rates that are not so high that they preclude pollutant removal function of soils • Soil composition that supports plant establishment and long-term health • Conditions differ greatly between the ponding area (Zone A) and side-slopes (Zone B); plant installation must accurately follow landscape plans. After planting, an inspection should ensure correct placement. • Plants should not block stormwater flows at inlets. The mature, full-size of plants should be estimated to determine proper setback from inlets, with adjustments made after installation, if plants are too close. • A two-inch layer of compost may be applied to retain moisture, prevent erosion, and suppress weed growth. Use the same compost from the bioretention soil mix specification and avoid bark mulches that can float during storm events. • Landscape installers should be aware to avoid compaction of the soil with machinery, or never working wet soils. Plant Nurseries LEGAL DISCLAIMER: This Technical Assistance Memo (TAM) is intended as guidance only and should not be used as a substitute for site specific design and engineering. Applicants are responsible for compliance with all code and rule requirements, whether or not described in this TAM. UC Davis LID Initiative Plant Establishment and Care Check with your local nursery for availability of plants on the LIDI Bioretention plant list. Additionally, LIDI’s Bioretention Vendor List, while it may not be inclusive of all suppliers, provides contact information for Central Coast nurseries that stock plants from the Bioretention plant list. For additional technical resources: www.centralcoastlidi.org For questions or to contact the Central Coast Low Impact Development Initiative: info@centralcoastlidi.org Source: Las Pilitas NurseryIrrigation is typically needed for two to three years following installation. After that period, native plants will need little to no supplemental irrigation to survive, however they may enter a dormant stage and appear dried up until rejuvenated by rains or supplemental irrigation. Because bioretention soils are formulated to infiltrate, irrigation application rates must be properly designed to avoid overwatering, and for systems with an underdrain prevent potential discharges through the underdrain. Compost Mulch (1” - 2”) may be reapplied to bioretention areas annually, or as the mulch layer breaks down. Use compost mulch (the same compost used in the bioretention soil mix) and avoid bark mulches that can float during storm events. Do not apply mulch just prior to the rainy season. Fertilizer should not be used in bioretention areas. Instead, a compost top dressing or application of compost tea can be used to introduce nutrients and beneficial microorganisms to the soil. Synthetic herbicides and pesticides should not be used in bioretention areas because of their potential toxicity risk to aquatic organisms. There are a variety of natural methods and products that can be used to control weeds and pests. Weeds compete with plants for nutrients, water, and sunlight. They should be regularly removed, with their roots, by hand pulling or with manual pincer-type weeding tools. Care should be given to avoid unnecessary compaction of soils while weeding. Replace plants that die due to unsuitable plant conditions, disease, underwatering, or other unforeseen issues. Dead and dying plants must be removed and replaced to avoid spreading disease, establishment of weeds in bare areas, and reduced LID function. Before replacing with the same species, determine if another species may be better suited to the conditions. Check tree staking, especially in high wind areas. Trees in bioretention areas may be more easily impacted by storms because of side- slope and saturated soil conditions. They should be inspected once or twice a year and following storm events to ensure they maintain a vertical, upright position during establishment. Stakes should be removed once they are no longer needed to encourage self supporting root systems (between one and two years). Like traditional landscapes, bioretention planting areas require care and ongoing maintenance for optimal health. Due to their functional nature as stormwater management facilities the following guidelines should be followed: Central Coast Low Impact Development Initiative Bioretention Plant List Plants for Zone A: Periodic inundation, area ponds following storm events (6" to 12" depth for 24 - 72 hours) and compost amended sand soil. 1 Refers to Sunset Western Garden Book Zones. The Central Coast includes the following Climate Zones: 1A, 2A, 3A, 7, 9, 14-24 www.sunset.com/garden/climate-zones/ Sun Part Shade Drought Inundation GRASS / GRASSLIKE Carex barbarae Santa Barbara Sedge/ Basket Sedge 1-2' / 1'-2'X X X X X 4 - 9, 14 - 23 Attracts butterflies, deer resistant, good for erosion control, can spread agressively and should be sited carefully. Carex divulsa Berkeley Sedge 1' / spreading X X X X X all, but 1A- 3A Attractive blue-grey leaves. Can be mowed 4 in high to keep clean look. Carex flacca Blue Sedge 1' / spreading X X X X 3A - 9, 14 - 23 Attractive blue-grey leaves. Can be mowed 4 in high to keep clean look. Carex praegracilis California Field Sedge 1' / spreading X X X X all, but 1A -3A Mounding, drought deciduous during summer months. Carex spissa San Diego sedge 3 - 4' / 2 - 3'X X X X X all, but 1A-3A Can handle foot traffic and is deer resistant. Chondropetalum tectorum Small Cape Rush 2 - 3' / 3 - 4'X X X X X all, but 1A-3A and 7 Needs very little maintenance. If trimmed too much plant will loose visual integrity. Leymus condensatus 'Canyon Prince' Canyon Prince Wild Rye 3'/3'X X X X all, but 1A-3A Tolerant of drought, poor soils, part shade and seasonal wet. Spreads by rhizomes, so nice planted in masses. Cut back annually in spring before new growth emerges. Juncus effusus Common Rush 2 - 3' / clumping X X X X all Easy to grow & very reliable. Needs more water than Juncus patens . Juncus patens 'Elk Blue' Elk Blue California Gray Rush 2' / clumping X X X X X all Very little maintenance, handles dry summers and wet winters. Muhlenbergia rigens Deer Grass 2 - 3' / 3 - 6'X X X X X all, but 1A-3A Can handle no watering, will stay green year round with watering, trim annually. Scirpus cernus Low Bulrush 1' / spreading X X X 7 - 24 Grow individually or in mass, cut back once a year, very attractive. NotesLight PreferencesScientific & Common Name Height / Width Sunset Climate Zones1 Water Tolerances CA Native Central Coast Low Impact Development Initiative Bioretention Plant List Plants for Zone A: Periodic inundation, area ponds following storm events (6" to 12" depth for 24 - 72 hours) and compost amended sand soil. 1 Refers to Sunset Western Garden Book Zones. The Central Coast includes the following Climate Zones: 1A, 2A, 3A, 7, 9, 14-24 www.sunset.com/garden/climate-zones/ Sun Part Shade Drought Inundation NotesLight PreferencesScientific & Common Name Height / Width Sunset Climate Zones1 Water Tolerances CA Native PERENNIALS Achillea millefolium californica Yarrow 1 - 3' / 2'X X X X X all Tolerates regular to no watering, foot traffic, attracts butterflies, stress deciduous. Anemopsis californica Yerba Mansa 1 - 2'/ spreading X X X X all, but 1A-3A Mat forming ground cover, interesting white flowers, prune back in late summer, likes moist conditions. Bidens laevis Joaquin Sunflower 2 - 3' / 1 - 2'X X X all but 1A Attracts beneficial insects, stress deciduous in summer, likes water but will survive drought if pruned back. Calliandra eriophylla Fairy Duster 1 - 3' / 1 - 3'X X X X 10 - 24 Very attractive 1 - 2 inch pink flowers , little water after established, semi-evergreen, attracts butterflies and hummingbirds. Epipactis gigantea Stream Orchid 1 - 2' / 2 - 3'X X X X all Will go dormant during drought, interesting muted pink and yellow flowers. Eschscholzia californica California Poppy 1 - 3 ' / 1 - 3"X X X X all Can handle periodic inundation, cut back yearly to prevent it from becoming weedy. Iris douglasiana Douglas Iris 1 - 2' / spreading X X X X all, but 1A-3A Needs moisture or shade inland, does well on coast, evergreen leaves, attractive lanvendar-blue flowers in Spring. Lilium pardalinum Leopard Lily 3 - 8' / 6"X X X X 2-7, 14-17 Attractive red-orange spotted blossoms in spring, needs regular water, will get large in moist, partial shade conditions. Lobelia cardinalis Cardinal Flower 2 - 3' / 2'X X X X X 1-7, 14-17 A bog plant, attracts hummingbirds, showy scarlet flowers. Mimulus cardinalis Scarlet Monkey Flower 1 - 3' / 1 - 3'X X X X X all but 1A Year round red color with regular water, attracts hummingbirds, reseeds itself & should not be used for small spaces. Mimulus guttatus Seep Monkey Flower 1 - 3' / 1 - 3'X X X X all but 1A Yellow flowers are abundant in spring-summer, attracts butterflies, will die back in drought and come back following year. Rudbeckia californica California Coneflower 2 - 5' / 1 - 2'X X X X all Yellow showy flowers late summer and fall, cut back in winter, can get large under ideal conditions and may require pruning. Salvia spathacea Hummingbird Sage 1 - 3' / spreading X X X X X all, but 1A-3A Very attractive foliage and flowers, fragrant, attracts hummingbirds, deer resistant, likes to grow in understory of trees. Sisyrinchium bellum Blue-Eyed Grass 6" - 1' / 6'' - 1 X X X X all, but 1A-3A Requires little to no maintenance. Summer dormant, will come back during wetter months on it's own. Can irrigate to prolong flowering. Solidago californica California Goldenrod 1 - 3' / 2 - 3'X X X X X X all, but 24 Attracts beneficial insects and butterflies. Attractive yellow flowering inflorescents in summer and fall. Dormant in winter, cut back to ground. Central Coast Low Impact Development Initiative Bioretention Plant List Plants for Zone A: Periodic inundation, area ponds following storm events (6" to 12" depth for 24 - 72 hours) and compost amended sand soil. 1 Refers to Sunset Western Garden Book Zones. The Central Coast includes the following Climate Zones: 1A, 2A, 3A, 7, 9, 14-24 www.sunset.com/garden/climate-zones/ Sun Part Shade Drought Inundation NotesLight PreferencesScientific & Common Name Height / Width Sunset Climate Zones1 Water Tolerances CA Native SHRUBS/SUBSHRUBS Baccharis pilularis Coyote Brush wide variation X X X X all, but 1A-3A Adaptable evergreen shrub, provides quick cover and bank stabilization, tolerant of coastal conditions, alkaline soil, sand, clay and seasonal wet, dwarf (low growing) varieties available. Zauschneria californica 'Catalina' Island California Fuchsia 1 - 3' / 2 - 3'X X X X X All but 1A Likes moisture but will survive through drought, attractive red flowers that hummingbirds like. This species is hardier and flowers last longer. Zauschneria californica 'Uvas Canyon' San Jose California Fuchsia 2 - 3' / spreading X X X X X All but 1A Grey foliage, attractive red- orange flowers, very showy in late fall. Full sun with regular watering or along coast. Can be mowed to look like lawn. Aesculus californica California Buckeye 15'X X X X X all but 1A-2A Small tree that has fragrant white panicles April - May.. Needs regular water for the first 2 years. Interesting form throughout all seasons. Good for native bee population. Amorpha californica California False Indigo Bush 6' / spreading X X X X X all, but 1A -3A Large shrub, with fragrant purple flowers. Needs no water after established. Provides larval food for California State butterfly. Cercis occidentalis Western Redbud 3 - 16' / 3 - 16'X X X X X all but 1A Needs winter chill to set flowers properly. Abundant amount of flowering purple-pink flowers in spring. Can be pruned to tree or left as shrub. Cornus californica California Dogwood 3 - 10'/ 3 - 10'X X X X all, but 1A -3A Attractive red branching stems with red deciduous leaves in winter. Good for erosion control. Showy white blooms in spring. Garrya elliptica 'James Roof' Silk Tassel 10 - 15'X X X X X all, but 1A -3A Drought tolerant where rainfall exceeds 20." Evergreen shrub - tree with hanging white catkins. Sambucus mexicana Tapiro, Blue Elderberry 6 - 15'X X X X X all but 1A Deciduous shub that can be pruned to a tree. Can handle extreme drought after first years. Needs maintenance to upkeep appearance. Attractive yellow flowers and edible blue berries. Great for ecosystem rehabilitation. Spiraea douglasii Western Spiraea 4 - 5'X X X X X all Deciduous shrub, fast growing. Attractive pink clustered flowers summer to early fall. Drought tolerant once established. Very adaptable. LARGE SHRUBS / TREES ���������������������������������������� ����������������������������������������������������������� ��������������������������������� ������������������������������������������� ������������������������������������������������������������� ������� ��������������������������������������������������������������� ���������������������������������������������������� ���������������������������� Protect Natural Features ���� ��� �������������������� ��������������������������������������� ���������������������������������������������������������������� ������������������������������������������������������ ������������������������������������������������������������� �������������������������������������������������������������� ������������������������������������������������������������� �������������������������������������������������������������� ���������������������������������� ����������������������������������������������������������� ��������������������������� Vegetative Buf fers �������������������������������������������������������� ����������������������������������������������������������������� ��������������������������������������������� ��������������������������������������������������������������������� ������������ ������������������������������������������������������������ Site Stabilization ��������������������������������������������������������������� ��������������������������������������������� � Silt Fencing ������������������������������������������������������������ ������������������������������������������� �������������������������������������������������� ���������������������������� ���������������������������������������������������� ������������������������������������� Dir t Stockpiles Storm Drain Inlet Protection �������������������������������� �������������������������������������������������������� ��������������������������������������������� �������������������������������������������������������������� ���������������������������������� ����������������������������������������������������������� ����������������������������������������������������������� ��������������� Slopes Construction Entrances ���� ��� ���� ��� ���� ��� ���� ��� ���� ��� ���� ��� ���� ��� ��� IN RIVERSIDE COUNTY ....Call 1-800-506-2555 TO REPORT ILLEGAL STORMDRAIN DISPOSAL E-mail: Flood.fcnpdes@co.riverside.ca.us Visit our website: www.floodcontrol.co.riverside.ca.us Brought to you by the Storm Water/Clean Water PollutionProtection Program..... REMEMBER, ONLY RAIN IN THE STORMDRAIN! Maintain your BMPs! Construction Phasing www.epa.gov/npdes/menuofbmps �������������������������������������������������������������������������������������������������������� ��������������������������������� n����������������� n���������������������������������������������� ������������������������������������������������������������������������� �������������������������������������������������������������������������� ���������������������������������������������������������������������������� �������������������������������������������������� �������������������� ������������������ n������������������� n������������������������������ n����������������������� n��������������������������������������� �� ����� ���������� ���� ���������� ���� ����������� ������� ���� ��� �������� ����������������������������������������������������������������� ����������������������������������������������������������������������� ����������������������������������������� 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Whyisstormwaterrunoff aproblem? Theeffectsofpollution Stormwater runoff occurs when precipitation from rain or snowmelt flows over the ground. Impervious surfaces like driveways, sidewalks, and streets prevent stormwater from naturally soaking into the ground. Stormwater can pick up debris, chemicals, dirt, and other pollutants and flow into a storm sewer system or directly to a lake, stream, river, wetland, or coastal water. Anything that enters a storm sewer system is discharged untreated into the waterbodies we use for swimming, fishing, and providing drinking water. Polluted stormwater runoff can have many adverse effects on plants, fish, animals, and people. Sediment can cloud the water and make it difficult or impossible for aquatic plants to grow. Sediment also can .destroy aquatic habitats Excess nutrients can cause algae blooms. When algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic organisms can’t exist in water with low dissolved oxygen levels. Bacteria and other pathogens can wash into swimming areas and create health hazards, often making beach closures necessary. Debris—plastic bags, six-pack rings, bottles, and cigarette butts—washed into waterbodies can choke, suffocate, or disable aquatic life like ducks, fish, turtles, and birds. Household hazardous wastes like insecticides, pesticides, paint, solvents, used motor oil, and other auto fluids can poison aquatic life. Land animals and people can become sick or die from eating diseased fish and shellfish or ingesting polluted water. Polluted stormwater often affects drinking water sources. This, in turn, can affect human health and increase drinking water treatment costs.AftertheStormEPA 833-B-03-002January 2003For more information contact:or visitwww.epa.gov/npdes/stormwaterwww.epa.gov/npsACitizen’sGuidetoUnderstandingStormwaterWHEN IT RAINSIT DRAINSWHEN IT RAINSIT DRAINSInternet Address (URL) HTTP://www.epa.govRecycled/Recyclable Printed With VegetableOil Based Inks on 100% Postconsumer,Process Chlorine Free Recycled Paper●● Auto care Washing your car and degreasing auto parts at home can send detergents and other contaminants through the storm sewer system. Dumping automotive fluids into storm drains has the same result as dumping the materials directly into a waterbody. Pet waste Pet waste can be a major source of bacteria and excess nutrients in local waters. When walking your pet, remember to pick up the waste and dispose of it properly. Flushing pet waste is the best disposal method. Leaving pet waste on the ground increases public health risks by allowing harmful bacteria and nutrients to wash into the storm drain and eventually into local waterbodies. Septic systems Leaking and poorly maintained septic systems release nutrients and pathogens (bacteria and viruses) that can be picked up by stormwater and discharged into nearby waterbodies. Pathogens can cause public health problems and environmental concerns. Lawn care Excess fertilizers and pesticides applied to lawns and gardens wash off and pollute streams. In addition, yard clippings and leaves can wash into storm drains and contribute nutrients and organic matter to streams. Education is essential to changing people's behavior. Signs and markers near storm drains warn residents that pollutants entering the drains will be carried untreated into a local waterbody.Recycle or properly dispose of household products that contain chemicals, such as insecticides, pesticides, paint, solvents, and used motor oil and other auto fluids. Don’t pour them onto the ground or into storm drains. Use a commercial car wash that treats or recycles its wastewater, or wash your car on your yard so the water infiltrates into the ground. Repair leaks and dispose of used auto fluids and batteries at designated drop-off or recycling locations. Don’t overwater your lawn. Consider using a soaker hose instead of a sprinkler. Use pesticides and fertilizers sparingly. When use is necessary, use these chemicals in the recommended amounts. Use organic mulch or safer pest control methods whenever possible. Compost or mulch yard waste. Don’t leave it in the street or sweep it into storm drains or streams. Cover piles of dirt or mulch being used in landscaping projects. Inspect your system every 3 years and pump your tank as necessary (every 3 to 5 years). Don't dispose of household hazardous waste in sinks or toilets. Dirt, oil, and debris that collect in parking lots and paved areas can be washed into the storm sewer system and eventually enter local waterbodies. Sweep up litter and debris from sidewalks, driveways and parking lots, especially around storm drains. Cover grease storage and dumpsters and keep them clean to avoid leaks. Report any chemical spill to the local hazardous waste cleanup team. They’ll know the best way to keep spills from harming the environment. Erosion controls that aren’t maintained can cause excessive amounts of sediment and debris to be carried into the stormwater system. Construction vehicles can leak fuel, oil, and other harmful fluids that can be picked up by stormwater and deposited into local waterbodies. Divert stormwater away from disturbed or exposed areas of the construction site. Install silt fences, vehicle mud removal areas, vegetative cover, and other sediment and erosion controls and properly maintain them, especially after rainstorms. Prevent soil erosion by minimizing disturbed areas during construction projects, and seed and mulch bare areas as soon as possible. Uncovered fueling stations allow spills to be washed into storm drains. Cars waiting to be repaired can leak fuel, oil, and other harmful fluids that can be picked up by stormwater. Clean up spills immediately and properly dispose of cleanup materials. Provide cover over fueling stations and design or retrofit facilities for spill containment. Properly maintain fleet vehicles to prevent oil, gas, and other discharges from being washed into local waterbodies. Install and maintain oil/water separators. Lack of vegetation on streambanks can lead to erosion. Overgrazed pastures can also contribute excessive amounts of sediment to local waterbodies. Excess fertilizers and pesticides can poison aquatic animals and lead to destructive algae blooms. Livestock in streams can contaminate waterways with bacteria, making them unsafe for human contact. Keep livestock away from streambanks and provide them a water source away from waterbodies. Store and apply manure away from waterbodies and in accordance with a nutrient management plan. Vegetate riparian areas along waterways. Rotate animal grazing to prevent soil erosion in fields. Apply fertilizers and pesticides according to label instructions to save money and minimize pollution. Permeable Pavement Rain Barrels Rain Gardens and Grassy Swales Vegetated Filter Strips —Traditional concrete and asphalt don’t allow water to soak into the ground. Instead these surfaces rely on storm drains to divert unwanted water. Permeable pavement systems allow rain and snowmelt to soak through, decreasing stormwater runoff. —You can collect rainwater from rooftops in mosquito- proof containers. The water can be used later on lawn or garden areas. —Specially designed areas planted with native plants can provide natural places for rainwater to collect and soak into the ground. Rain from rooftop areas or paved areas can be diverted into these areas rather than into storm drains. —Filter strips are areas of native grass or plants created along roadways or streams. They trap the pollutants stormwater picks up as it flows across driveways and streets. Residential landscaping Improperly managed logging operations can result in erosion and sedimentation. Conduct preharvest planning to prevent erosion and lower costs. Use logging methods and equipment that minimize soil disturbance. Plan and design skid trails, yard areas, and truck access roads to minimize stream crossings and avoid disturbing the forest floor. Construct stream crossings so that they minimize erosion and physical changes to streams. Expedite revegetation of cleared areas. Commercial StormwaterPollutionSolutions Construction Agriculture Automotive Facilities Forestry