Attachment 3 Final Mitigated Negative Declaration — Thousand Oaks City Council, March 25, 2025 (part 1 of 2)

FINAL
FEBRUARY 2025Prepared for:CITY OF THOUSAND OAKS2100 Thousand Oaks BoulevardThousand Oaks, California 91362Contact: Nader Heydari, PE, CCM, LEED AP, QSD, Deputy Public Works Director/City EngineerPrepared by:27271 Las Ramblas, Suite 340Mission Viejo, CA 92691Contact: Rachel Struglia, PhD, AICP

Printed on 30% post-consumer recycled material.

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Table of Contents SECTION PAGE Acronyms and Abbreviations ............................................................................................................................................. v 1 Introduction .......................................................................................................................................................... 1 1.1 Project Overview ..................................................................................................................................... 1 1.2 California Environmental Quality Act Compliance ................................................................................ 1 1.3 Public Review Process ........................................................................................................................... 1 1.4 Initial Study Checklist ............................................................................................................................. 2 2 Project Description ............................................................................................................................................... 3 2.1 Project Overview ..................................................................................................................................... 3 2.2 Project Location ...................................................................................................................................... 3 2.3 Environmental Setting ............................................................................................................................ 3 2.4 Project Background and Need ............................................................................................................... 4 2.5 Project Characteristics ........................................................................................................................... 4 2.5.1 Proposed Components ............................................................................................................. 4 2.5.2 Project Operational Characteristics ......................................................................................... 5 2.5.3 Project Construction and Scheduling ...................................................................................... 6 2.6 Project Approvals .................................................................................................................................... 6 2.7 Cumulative Projects ............................................................................................................................... 6 3 Initial Study Checklist........................................................................................................................................... 9 3.1 Aesthetics ............................................................................................................................................ 14 3.2 Agriculture and Forestry Resources ................................................................................................... 16 3.3 Air Quality ............................................................................................................................................. 17 3.4 Biological Resources ........................................................................................................................... 27 3.4.1 Environmental Setting ........................................................................................................... 27 3.5 Cultural Resources .............................................................................................................................. 52 3.6 Energy .................................................................................................................................................. 61 3.7 Geology and Soils ................................................................................................................................ 64 3.8 Greenhouse Gas Emissions ................................................................................................................ 69 3.9 Hazards and Hazardous Materials ..................................................................................................... 74 3.10 Hydrology and Water Quality ............................................................................................................... 78 3.11 Land Use and Planning ....................................................................................................................... 81 3.12 Mineral Resources .............................................................................................................................. 82 3.13 Noise .................................................................................................................................................... 83 3.14 Population and Housing ...................................................................................................................... 90 3.15 Public Services .................................................................................................................................... 91 3.16 Recreation ............................................................................................................................................ 92

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3.17 Transportation ..................................................................................................................................... 93 3.18 Tribal Cultural Resources .................................................................................................................... 95 3.19 Utilities and Service Systems ............................................................................................................ 101 3.20 Wildfire ............................................................................................................................................... 103 3.21 Mandatory Findings of Significance ................................................................................................. 106 4 References and Preparers .............................................................................................................................. 109 4.1 References Cited ............................................................................................................................... 109 4.2 List of Preparers ................................................................................................................................ 115 5 Response to Comments ................................................................................................................................. 137 6 Mitigation Monitoring and Reporting Program .............................................................................................. 143 TABLES 2-1 Cumulative Projects ............................................................................................................................................. 6 3-1 Construction Scenario Assumptions ................................................................................................................ 20 3-2 Estimated Maximum Daily Construction Criteria Air Pollutant Emissions ..................................................... 21 3-3 Vegetation and Land Cover Types within the BSA .......................................................................................... 28 3-4 Summary of City-Regulated Tree Species within the BSA .............................................................................. 30 3-5 Special-Status Plant Species Observed within the Biological Survey Area ................................................... 32 3-6 Special-Status Wildlife Species Observed or with a Moderate to High Potential to Occur ........................... 32 3-7 RWQCB Aquatic Resource Summary for the Biological Survey Area ............................................................. 36 3-8 CDFW Aquatic Resource Summary for the Biological Survey Area ................................................................ 37 3-9 Proposed Impacts to Vegetation and Land Cover Types within the BSA ....................................................... 49 3-10 Previous Technical Studies Within a 0.5-Mile Radius of the Project Site ...................................................... 53 3-11 Previously Recorded Cultural Resources within a 0.5-Mile Radius of the Proposed Project Site ................ 56 3-12 Total Project Construction Petroleum Demand ............................................................................................... 63 3-13 Estimated Annual Construction Greenhouse Gas Emissions ......................................................................... 71 3-14 Typical Sound Levels in the Environment and Industry .................................................................................. 84 3-15 Measured Noise Levels .................................................................................................................................... 85 3-16 Construction Noise Model Results Summary .................................................................................................. 88 6-1 Mitigation Monitoring and Reporting Program .............................................................................................. 144 FIGURES 1 Project Location .............................................................................................................................................. 117 2 Project Site ...................................................................................................................................................... 119 3 Biological Resources ....................................................................................................................................... 121 4 Project Improvements ..................................................................................................................................... 123

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5 Vegetation Communities and Land Cover Types........................................................................................... 125 6 City-Regulated Trees ....................................................................................................................................... 127 7 USFWS Critical Habitat ................................................................................................................................... 129 8 Potential Jurisdictional Aquatic Resources ................................................................................................... 131 9 Impacts to Biological Resources .................................................................................................................... 133 10 Noise Measurement Locations ...................................................................................................................... 135 APPENDICES A B1 B2 C1 C2 D Air Quality, Greenhouse Gas Emissions, Energy Calculations Biological Resources Assessment Report Aquatic Resources Delineation Report Archaeological Resources Assessment Built Environment Inventory and Evaluation Report Noise Modeling Results

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Acronyms and Abbreviations Acronym/Abbreviation Definition AB Assembly Bill AQMP Air Quality Management Plan ARDR Aquatic Resources Delineation Report BMP best management practice BRAR Biological Resources Assessment Report for the Hill Canyon Treatment Plant Stormwater Diversion Project BSA Biological Survey Area CAAQS California Ambient Air Quality Standards Cal/OSHA California Department of Industrial Relations Division of Occupational Safety and Health CalEEMod California Emissions Estimator Model Caltrans California Department of Transportation CARB California Air Resources Board CDFW California Department of Fish and Wildlife CEQA California Environmental Quality Act CFGC California Fish and Game Code cfs cubic feet per second CH4 methane CHRIS California Historical Resources Information System City City of Thousand Oaks CNEL Community Noise Equivalent Level CO carbon monoxide CO2 carbon dioxide CO2e carbon dioxide equivalent County Ventura County CRHR California Register of Historical Resources dB decibels dBA A-weighted decibel DPM diesel particulate matter DTSC Department of Toxic Substances Control EIR environmental impact report ESCP Erosion and Sediment Control Plan FTA Federal Transit Administration GHG greenhouse gas IGP Industrial General Permit ips inches per second IS Initial Study LACM IP Los Angeles County Museum Invertebrate Paleontology LACM VP Los Angeles County Museum Vertebrate Paleontology Ldn day/night average sound level

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Acronym/Abbreviation Definition Leq energy-equivalent sound level Lxx statistical sound level MBTA Migratory Bird Treaty Act MM Mitigation Measure MND Mitigated Negative Declaration MT metric ton N2O nitrous oxide NAAQS National Ambient Air Quality Standards NAHC Native American Heritage Commission NHMLA Natural History Museum of Los Angeles County NO2 nitrogen dioxide NONA Notice of Non-Applicability NOx oxides of nitrogen O3 ozone OPR P-L Public, Quasi-Public, and Institutional Lands and Facilities PM10 particulate matter less than 10 microns in diameter PPV peak particle velocity PRC California Public Resources Code PRIMP Paleontological Resources Impact Mitigation Program project Hill Canyon Treatment Plant Stormwater Diversion Project RCNM Roadway Construction Noise Model ROC reactive organic compound RTP/SCS Regional Transportation Plan/Sustainable Communities Strategy RWQCB Regional Water Quality Control Board SB Senate Bill SCAG Southern California Association of Governments SCAQMD South Coast Air Quality Management District SCCAB South-Central Coast Air Basin SCCIC South Central Coastal Information Center SLF Sacred Lands File SR State Route SSC Species of Special Concern SWPPP stormwater pollution prevention plan TAC toxic air contaminant Treatment Plant Hill Canyon Treatment Plant USACE U.S. Army Corps of Engineers USFWS U.S. Fish and Wildlife Service VCAPCD Ventura County Air Pollution Control District VCFD Ventura County Fire Department VMT vehicle miles traveled WEAP Worker Environmental Awareness Program

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1 Introduction 1.1 Project Overview This Draft Initial Study (IS) was prepared in accordance with the California Environmental Quality Act (CEQA) to evaluate the potential environmental effects associated with the Hill Canyon Treatment Plant Stormwater Diversion Project (project), proposed by the City of Thousand Oaks (City) and located within the City of Thousand Oaks. The project involves improvements to the Hill Canyon Treatment Plant (Treatment Plant), including the development of a new debris basin and storm drain improvements. 1.2 California Environmental Quality Act Compliance The City is the lead agency responsible for the preparation of the environmental documentation and for the approval of the project. Based on the findings of this Draft IS, the City has made the determination that a Mitigated Negative Declaration (MND) is the appropriate environmental document to be prepared in compliance with CEQA (California Public Resources Code, Section 21000 et seq.). This IS/MND has been prepared by the City and is in conformance with Section 15070(a) of the CEQA Guidelines (14 CCR 15000 et seq.). The purpose of the MND and the IS checklist is to determine any potentially significant impacts associated with the project and to incorporate mitigation measures into the project design, as necessary, to reduce or eliminate significant or potentially significant effects. As determined in this IS/MND, there is no substantial evidence, in light of the whole record before the agency, that the project would have a significant effect on the environment. 1.3 Public Review Process This IS/MND has been made available for public review to potentially affected agencies and individuals for a period of 30 days, in accordance with Section 15073 of the State CEQA Guidelines. During review of the IS/MND, affected and analyzing the potential environmental impacts and the ways in which the potentially significant effects of the project can be avoided or mitigated. Notices of the availability of the IS/MND for review and comment, as well as the environmental documentation, are available for review on the City https://www.toaks.org/departments/community-development/planning/environmental-impact

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Comments on the IS/MND must be received by 5:00 p.m., September 14, 2023, and should be sent:ViaEmailto:[email protected]:Nader Heydari, Deputy Public Works Director/City EngineerCity of Thousand Oaks2100 Thousand Oaks BoulevardThousand Oaks, California 91362Following the close of the public comment period, the City will consider this IS/MND and comments thereto in determining whether to approve the project.Following receipt and evaluation of comments from agencies, organizations, and/or individuals, the City will determine whether any substantial new environmental issues have been raised. If so, further documentationsuch as an environmental impact report (EIR) or an expanded IS/MNDmay be required. If not, the project and the environmental documentation will be scheduled to be submitted to the CityPlanning Commission for consideration.1.4 Initial Study ChecklistSections 1506315065. The CEQA Guidelines include a suggested checklist to indicate whether a project would have an adverse impact on the environment. The checklist is found in Section 3 of this document. Following the Environmental Checklist, Sections 3.1 through 3.21 include an explanation and discussion of each significance determination made in the checklist for the project. For this IS/MND, the following four possible responses to each individual environmental issue area are included in the checklist:

Potentially Significant Impact
Less-than-Significant Impact with Mitigation Incorporated Less-than-Significant Impact
No ImpactThe checklist and accompanying explanation of checklist responses provide the information and analysis necessary to assess relative environmental impacts of the project. In doing so, the City will determine the extent of additional environmental review, if any, for the project.

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2 Project Description 2.1 Project Overview This Draft IS was prepared in accordance with CEQA to evaluate the potential environmental effects associated with the project, proposed by the City. The project involves improvements to the Treatment Plant, including the development of a new debris basin and storm drain improvements. See Section 2.5, Project Characteristics, for additional detail. 2.2 Project Location The project site (Assessors Parcel Numbers: 552-013-001 and 667-012-017) is located at the Treatment Plant (Figure 1, Project Location). The address for the Treatment Plant is 9600 Santa Rosa Road at the confluence of north and south Arroyo Conejo Creek and within the western limits of the City in Ventura County, California. 2.3 Environmental Setting The project site is located within a 60-acre open space parcel that contains the Treatment Plant (Figure 2, Project Site). The Treatment Plant contains primary treatment facilities; secondary treatment facilities; tertiary treatment facilities; a receiving station to handle solids, fats, oil, and grease; energy facilities; and other facilities. The project site is located between two publicly owned open space systems, including Wildwood Regional Park, which is approximately 1,765 acres, and Conejo Canyons Open Space, which is approximately 1,430 acres. The project site is bound by Hill Canyon Fire Road to the northwest and undeveloped vegetated land to the north, east, and south. The area surrounding the project site is predominantly open space with residential and commercial properties approximately 0.25 miles south and east of the site. The City of Thousand Oaks General Plan Land Use Element designates the project site as Institutional (City of Thousand Oaks 2018). The Cityoning map designates the site as Public, Quasi-Public, and Institutional Lands and Facilities (P-L) (City of Thousand Oaks 2022). The land surrounding the project site has a land use designation of Existing Parks, Golf Courses, and Open Space (City of Thousand Oaks 2018). Additionally, the land surrounding the project site is zoned Open Space (OS) (City of Thousand Oaks 2022). The project is located within the boundaries of the fully developed Treatment Plant and on land adjacent to the Treatment Plant. The Treatment Plant is surrounded by undeveloped habitats that are characteristic of the adjacent open space areas. The natural undeveloped habitats are composed of a combination of vegetation communities, including chamise chaparral (Adenostoma fasciculatum), California brittle bush (Encelia californica)California sagebrush (Artemisia californica)black sage scrub (Salvia mellifera), lemonade berry scrub (Rhus integrifolia), and lemonade berry scrubCalifornia sagebrush scrub. Along with the scrub communities, several large shrubs of toyon (Heteromeles arbutifolia) and mature oak trees (California black oak [Quercus kelloggii], coast live oak [Quercus agrifolia]/interior live oak [Quercus wislizeni]) are present. California sycamore (Platanus racemosa)arroyo willow (Salix lasiolepis) woodlands were mapped along Arroyo Conejo Creek. Based on the California Department of Fish and Wildlife (CDFW) California Natural Communities List, and under CEQA, most of these vegetation communities within the project site would be considered sensitive. These resources are shown on Figure 3, Biological Resources.

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A number of special-status wildlife species are documented in the areas surrounding the project site and have a potential to occur in the undeveloped portions of the biological survey area. In the scrub areas, wildlife species include the coastal California gnatcatcher (Polioptila californica californica; federally threatened, CDFW Species of Special Concern [SSC]) and other CDFW SSC such as coast horned lizard (Phrynosoma blainvillii, CDFW SSC), San Bernardino ringneck snake (Diadophis punctatus modestus), legless lizards (Anniella sp.), and coastal whiptail (Aspidoscelis tigris stejnegeri). Along Arroyo Conejo Creek, special-status species may include the federally and State endangered Vireo bellii pusillus) and southwestern willow flycatcher (Empidonax traillii extimus), as well as CDFW SSC species such as arroyo chub (Gila orcuttii), western pond turtle (Emys marmorata), and two-striped garter snake (Thamnophis hammondii). Refer to Section 3.4, Biological Resources, for further details regarding biological resources. The project site is not located within a Natural Community Conservation Plan/ Habitat Conservation Plan. 2.4 Project Background and Need The Treatment Plant, which is owned and operated by the City, provides wastewater treatment for the City. The Treatment Plant is a 14-million-gallon-per-day-capacity wastewater treatment plant and currently treats an average of 8 million gallons of wastewater per day generated from its domestic, commercial, and industrial customers. The Treatment Plant is located at the confluence of two watersheds and experiences flooding in certain areas of the plant due to off-site run-on after large storm events that exceed the capacity of some drainage facilities for conveying off-site flows. These high runoff events are followed by a subsequent cleanup and debris removal associated with run-on flows from the tributary canyons that overflow into the Treatment Plant. Under existing conditions, flows are intercepted by a concrete swale that sits behind an existing reinforced concrete wall, directing flows to drain inlets that connect to an existing 30-inch storm drain system. To maintain compliance with the Industrial General Permit Notice of Non-Applicability (NONA) for the IGP requirements, the City disconnected the 30-inch storm drain from outletting off site and added a sump pump system to divert on-site storm flows to an on-site basin. The maximum capacity of the existing 30-inch storm drain is 50 cubic feet per second (cfs). The 10-year combined peak flow rate of the two watersheds is 105 cfs. The City determined that it was not feasible to increase the size of the 30-inch storm drain due to space constraints within the Treatment Plant. Therefore, the proposed design flow is limited to the capacity of the existing 30-inch storm drain and another design solution to intercept, capture, and contain stormwater flows is necessary. Implementation of the project would include the following: (1) re-establishing the existing 30--site outlet; (2) constructing new pipes to contain on-site flows within the site and maintain NONA status related to the IGP; and (3) constructing a debris basin to contain flooding and the accompanying debris after storm events associated with run-on flows from the tributary canyons that overflow onto the project site. 2.5 Project Characteristics 2.5.1 Proposed Components Existing 30-inch Storm Drain Under existing conditions, the existing 30-inch storm drain ties into a sump pump system that diverts flows to the adjacent sludge-drying beds. The diverted storm flows are combined with the wastewater flow through the Treatment Plant. The project would demolish the sump pump and re-establish the connection to the existing 30-inch

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to transport off-site flows from the adjacent canyon. The original outfall outlets to the South Arroyo Conejo Creek. The maximum capacity of the existing 30-inch storm drain is 50 cfs. The City determined that is not feasible to increase the size of the 30-inch storm drain due to space constraints within the Treatment Plant. Therefore, the project would be limited to the capacity of the existing 30-inch storm drain and another design solution to intercept, capture, and contain stormwater flows is necessary. Proposed Storm Drain Pipes Upstream of the demolished pipe segment, a proposed storm drain pipe (Pipe A) would divert on-site flows to the existing flow equalization basin overflow structure that is routed to the sludge-drying beds. The alignment of Pipe A would be within the existing flow equalization basin side slope. Pipe A would be 36 inches in diameter and have a full flow capacity of 55 cfs. The proposed Pipe A would be slightly larger in diameter by 6 inches and would increase flow by 5 cfs. This would allow for the preservation of the NONA status. A second proposed storm drain pipe (Pipe B) would receive off-site flows from the proposed channel at the upstream end and tie into the existing 30-inch storm drain at the downstream end. Pipe B would be 24 inches in diameter and have a full flow capacity of 93 cfs. There would not be any on-site stormwater connections to this pipeline. It would only transport flows captured off site in Pipe C through the Treatment Plant to the existing outfall. A third proposed storm drain pipe (Pipe C) would receive off-site flows from the proposed debris basin at the upstream end and outlet to the proposed channel at the downstream end. Pipe C would be 24 inches in diameter and would have a full flow capacity of 50 cfs. Proposed Debris Basin The proposed debris basin would be incorporated at the upstream end of the eastern side of the Treatment Plant to intercept all debris and allow clear water flows to continue downstream into the storm drain system pipe where it is routed to the outfall location. Proposed Channel The proposed channel would connect to the proposed debris basin at the upstream end by Pipe C. The proposed channel would convey 50 cfs flows. Figure 4, Project Improvements, shows the proposed improvements to the Treatment Plant. 2.5.2 Project Operational Characteristics Upon completion of construction, the project would continue providing off-site stormwater managment for the City. Similar to the existing conditions, staff would occasionally visit the project site for routine maintenance or in the event of an emergency. Operational impacts are considered to be minimal as operations would be very similar to the existing conditions.

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2.5.3 Project Construction and Scheduling Construction of the project is anticipated to occur over approximately 6 months. Project construction includes demolition of the sump pump associated with the existing 30-inch storm drain, demolition of the retaining wall structures, demolition of drainage features and vegetation in the area of the proposed debris basin, site preparation and grading, construction of three new storm drain pipes and concrete channel, a debris basin and retaining wall structures, and reconnection of the 30-inch storm drain pipe. Materials required for construction would include piping, concrete blocks for the walls, and concrete. Water for concrete installation, dust control, and erosion control would also be required. The heavy equipment listed in Table 3-1, Construction Scenario Assumptions, may be used during construction activities. 2.6 Project Approvals Discretionary Actions The actions and/or approvals that the City needs to consider for the project include, but are not limited to, the following: Project Approval and Adoption of the IS/MND. Following public review and comment of this IS/MND, the project and this IS/MND would require approval by the City Council. Subsequent nondiscretionary approvals would include: Aquatic Resource Permits. If required, based on aquatic resources delineation survey findings, the project would obtain permits pursuant to Section 404 and 401 of the Clean Water Act (U.S. Army Corps of Engineers [USACE]/Regional Water Quality Control Board [RWQCB]) and Section 1600 et. seq. of the California Fish and Game Code (CDFW). Construction General Permit. Because the project would involve ground disturbance greater than 1 acre, the project would require coverage under the General Permit for Construction Activities, which would involve the preparation of a stormwater pollution prevention plan (SWPPP). Oak/Landmark Tree Permit. If the project would remove an oak or landmark tree, then the project would require an Oak/Landmark Tree Permit from the City. 2.7 Cumulative Projects The table below includes the cumulative projects within the City. Table 2-1. Cumulative Projects Project Name Proposed Land Uses/Description Location Status/Operational Start Date Calleguas Las Virgenes Interconnection Calleguas will construct a new pump station/pressure-reducing station (PS/PRS) and the North Interconnection Pipeline segment. PS/PRS along Lindero Canyon Road just north of the Ventura The project began construction in April 2022 and is expected to be completed in 2024.

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Table 2-1. Cumulative Projects Project Name Proposed Land Uses/Description Location Status/Operational Start Date County/Los Angeles County line North Interconnection Pipeline segment along Lindero Canyon Road between the PS/PRS and Kanan Road Conejo Canyon Bridge The project includes construction of a steel bridge across the Arroyo Conejo Creek. Arroyo Conejo Creek southwest of Hill Canyon Road in the Conejo Canyons Open Space area Construction is expected to begin in September 2023 and will be completed by February 2024. Electric Vehicle (EV) Charging Station Project The project installs four EV charging stations at the Grant Brimhall Library and three EV charging stations at the Newbury Park Library. The Grant Brimhall Library at 1401 East Janss Road Newbury Park Library at 2331 Borchard Road The project will begin in March 2023 and is expected to be completed by December 2023. Flashing Yellow Arrow Traffic Signals Project The City is in the process of installing flashing yellow arrow traffic signals at multiple intersections to improve traffic flow. Throughout the City Ongoing Groundwater Recovery Project The City is studying the feasibility of groundwater within the Conejo Valley as an alternative to imported water for irrigation and potable use. The existing Los Robles Golf Course groundwater well, at 299 S Moorpark Road. Prior to planning for the full-scale treatment facility, the City intends to complete additional testing to further evaluate the groundwater basin's characteristics and well's sustainable yield. Janss Road Underground Project As part of the Utility Undergrounding Master Plan, the utilities aboveground on Janss Road will be placed underground. Janss Road The project is currently in the design phase to develop final project plans by Southern California Edison and the telecom companies. Once all project plans have been completed, a final construction time frame will be

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Table 2-1. Cumulative Projects Project Name Proposed Land Uses/Description Location Status/Operational Start Date developed, which is anticipated to be 2023. Construction is expected to begin in the first quarter of 2023. Lawrence Drive and Teller Road Intersection Improvements The project consists of widening and realigning Teller Road at Lawrence Drive to align the eastbound and westbound lanes; constructing roadway pavement, sidewalk, crosswalk, curb, gutter, and curb ramps; installing traffic signals, signing and striping; and landscaping and irrigation. Teller Road and Lawrence Road intersection Construction phase is expected to be completed in spring 2023. Meadows Reservoir Emergency Repairs Emergency work to repair unexpected failure at the Meadows Reservoir. Meadows Reservoir site In February 2022, the City Council approved the implementation of emergency remedial work. Upon completion of investigative and remedial work, staff will report back to the City Council with the required subsequent steps and the scope of required repairs. State Route (SR) 23 Rehabilitation Project A California Department of Transportation project, the SR-23 Rehabilitation Project will replace pavement on the outer two lanes from U.S. Highway 101 to SR-118. The on- and off-ramps, connectors, and adjacent shoulders also will be rehabilitated, and slabs will be replaced on the inner lane in both directions where needed. Existing curbs ramps will be upgraded where necessary to comply with the Americans with Disabilities Act, and approach slabs and bridge rails will be replaced at select locations. In Ventura County, from U.S. Highway 101 to SR-118 The project is anticipated to start construction in summer 2020 and be completed fall 2023. Unit-W The Public Works Department seeks to rehabilitate various wastewater lines and maintenance holes throughout the City with a non-invasive lining product. Throughout the City Construction has begun.

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3 Initial Study Checklist 1.Project title: Hill Canyon Treatment Plant Stormwater Diversion Project 2. Lead agency name and address: City of Thousand Oaks 2100 Thousand Oaks Boulevard Thousand Oaks, California 91362 3. Contact person and phone number: Nader Heydari, Deputy Public Works Director/City Engineer 805.449.2400 4. Project location: The project would be located at Hill Canyon Treatment Plant (Assessors Parcel Numbers: 552-013-001 and 667-012-017), which is located in the City of Thousand Oaks (City), Ventura County (County), within southern California. The project site would be located within a 60-acre open space parcel. 5. Nader Heydari City of Thousand Oaks 2100 Thousand Oaks Boulevard Thousand Oaks, California 91362 6. General plan designation: Institutional 7. Zoning: Public, Quasi-Public, and Institutional Lands and Facilities (P-L) 8. Description of project. (Describe the whole action involved, including but not limited to later phases of the project, and any secondary, support, or off-site features necessary for its implementation. Attach additional sheets if necessary): The project includes hydraulic improvements to the stormwater diversion system that would eliminate flooding and the accompanying debris experienced after storm events associated with flows from two tributaries that overflow onto the project site. Improvements would include re-establishing an existing 30-inch storm drain connection to its original off-site outlet and the development of a new debris basin, channel, and three storm drains. Project components are described in greater detail below.

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9.The project site is located between two publicly owned open space systems including Wildwood RegionalPark, which is approximately 1,765 acres, and Conejo Canyons Open Space, which is approximately 1,430acres. The project site is bound by Hill Canyon Fire Road to the northwest and undeveloped vegetated landto the north, east, and south. The area surrounding the project site is predominantly open space withresidential and commercial properties approximately 0.25 miles south and east of the site.10.Other public agencies whose approval is required (e.g., permits, financing approval, or participation agreement):Aquatic Resource Permits. If required, based on aquatic resources delineation survey findings, theproject would obtain permits pursuant to Section 404 and 401 of the Clean Water Act (USACE/RWQCB)and Section 1600 et. seq. of the California Fish and Game Code (CDFW).Construction General Permit. Because the project would involve ground disturbance greater than 1acre, the project would require coverage under the State RWQCB General Permit for ConstructionActivities, which would involve the preparation of a SWPPP.Oak/Landmark Tree Permit. If the project would remove an oak or landmark tree, then the projectwould require an Oak/Landmark Tree Permit from the City.11.Have California Native American tribes traditionally and culturally affiliated with the project area requestedconsultation pursuant to Public Resources Code section 21080.3.1? If so, is there a plan for consultationthat includes, for example, the determination of significance of impacts to tribal cultural resources,procedures regarding confidentiality, etc.?Note: Conducting consultation early in the CEQA process allows tribal governments, lead agencies, andproject proponents to discuss the level of environmental review, identify and address potential adverseimpacts to Tribal Cultural Resources, and reduce the potential for delay and conflict in the environmentalreview process (see Public Resources Code Section 21080.3.2.). Information may also be available from(PRC)Section 5097.96 and the California Historical Resources Information System administered by the CaliforniaOffice of Historic Preservation. Please also note that PRC Section 21082.3(c) contains provisions specificto confidentiality.Please see Section 3.18, Tribal Cultural Resources.

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Environmental Factors Potentially Affected The environmental factors checked below would be potentially affected by this project, involving at least one impact No boxes are checked because all project impacts would be no impact, less-than-significant impact, or less-than-significant impact with mitigation incorporated. Aesthetics Agriculture and Forestry Resources Air Quality Biological Resources Cultural Resources Energy Geology and Soils Greenhouse Gas Emissions Hazards and Hazardous Materials Hydrology and Water Quality Land Use and Planning Mineral Resources Noise Population and Housing Public Services Recreation Transportation Tribal Cultural Resources Utilities and Service Systems Wildfire Mandatory Findings of Significance Determination (To be completed by the Lead Agency) On the basis of this initial evaluation: I find that the proposed project COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared. I find that although the proposed project could have a significant effect on the environment, there will not be a significant effect in this case because revisions in the project have been made by or agreed to by the project proponent. A MITIGATED NEGATIVE DECLARATION will be prepared. I find that the proposed project MAY have a significant effect on the environment, and an ENVIRONMENTAL IMPACT REPORT is required. been adequately analyzed in an earlier document pursuant to applicable legal standards, and (2) has been addressed by mitigation measures based on the earlier analysis as described on attached sheets. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects that remain to be addressed. I find that although the proposed project could have a significant effect on the environment, because all potentially significant effects (a) have been analyzed adequately in an earlier ENVIRONMENTAL IMPACT REPORT or NEGATIVE DECLARATION pursuant to applicable standards, and (b) have been avoided or mitigated pursuant to that earlier ENVIRONMENTAL IMPACT REPORT or NEGATIVE DECLARATION, including revisions or mitigation measures that are imposed upon the proposed project, nothing further is required. Signature Date 112767 FEBRUARY 2025

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HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 13FEBRUARY 2025
EvaluationofEnvironmentalImpacts
A brief explanation is answer is adequately supported if the referenced information sources show that the impact simply does answer should be explained where it is based on project-specific factors as well as general standards (e.g., the project will not expose sensitive receptors to pollutants, based on a project-specific screening analysis).

All answers must take account of the whole action involved, including off-site as well as on-site, cumulative as well as project-level, indirect as well as direct, and construction as well as operational impacts.

Once the lead agency has determined that a particular physical impact may occur, then the checklist answers must indicate whether the impact is potentially significant, less than significant with mitigation, or determination is made, an Environmental Impact Report (EIR) is required. the mitigation measures, and briefly explain how they in (5) below, may be cross-referenced).

Earlier analyses may be used where, pursuant to the tiering, program EIR, or other CEQA process, an effect has been adequately analyzed in an earlier EIR or negative declaration. Section 15063(c)(3)(D). In this case, a brief discussion should identify the following:a. Earlier Analysis Used. Identify and state where they are available for review.b. Impacts Adequately Addressed. Identify which effects from the above checklist were within the scope of and adequately analyzed in an earlier document pursuant to applicable legal standards, and state whether such effects were addressed by mitigation measures based on the earlier analysis.c.Less Than Significant With Mitigation Measures document and the extent to which they address site-specific conditions for the project.

Lead agencies are encouraged to incorporate into the checklist references to information sources for potential impacts (e.g., general plans, zoning ordinances). Reference to a previously prepared or outside document should, where appropriate, include a reference to the page or pages where the statement is substantiated.

Supporting Information Sources: A source list should be attached, and other sources used or individuals contacted should be cited in the discussion.

This is only a suggested form, and lead agencies are free to use different formats; however, lead agencies effects in whatever format is selected.

The explanation of each issue should identify:a. The significance criteria or threshold, if any, used to evaluate each question; andb. The mitigation measure identified, if any, to reduce the impact to less than significance

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 14 FEBRUARY 2025

3.1 Aesthetics Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact I. AESTHETICS Except as provided in Public Resources Code Section 21099, would the project: a) Have a substantial adverse effect on a scenic vista? b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a State scenic highway? c) In non-urbanized areas, substantially degrade the existing visual character or quality of public views of the site and its surroundings? (Public views are those that are experienced from publicly accessible vantage point). If the project is in an urbanized area, would the project conflict with applicable zoning and other regulations governing scenic quality? d) Create a new source of substantial light or glare which would adversely affect day or nighttime views in the area? a) Would the project have a substantial adverse effect on a scenic vista? Less-than-Significant Impact. A scenic vista is typically defined as a public view of highly valued visual and scenic resources such as the ocean and distant mountain ranges, particularly from public vantage points. The project site is located between two publicly owned open space systems, including Wildwood Regional Park and Conejo Canyons Open Space, which both contain valuable scenic resources (City of Thousand Oaks 2013). The project, however, involves relatively minor improvements at an existing wastewater treatment plant to add a stormwater diversion basin. The proposed project would not substantially change the visual character of the project site. Therefore, the project would not have a substantial adverse effect on a scenic vista, and impacts would be less than significant. b) Would the project substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a State scenic highway? No Impact. The nearest State scenic highway is an eligible for designation stretch of U.S. Highway 101 located approximately 1.75-mile south of the project site (Caltrans 2018) and which is not visible from the project site. As such, the project would have no impact related to the damage of scenic resources within a State scenic highway.

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 15 FEBRUARY 2025
c) In non-urbanized areas, would the project substantially degrade the existing visual character or quality of public views of the site and its surroundings? (Public views are those that are experienced from publicly accessible vantage point). If the project is in an urbanized area, would the project conflict with applicable zoning and other regulations governing scenic quality? Less-than-Significant Impact. In 2021, the City (which includes the project site) had a population of 125,754. As such, the City is considered an urbanized area pursuant to PRC Section 21071. Therefore, the first question of Threshold 3.1(c) does not apply to the proposed project, as it is directed at non-urbanized areas. The proposed project would be located at the existing Treatment Plant, which is located on a 60-acre parcel between two publicly owned open space systems, including Wildwood Regional Park and Conejo Canyons Open Space. As previously discussed, the Treatment Plant, including the project site, has a zoning designation of Public, Quasi-Public, and Institutional Lands and Facilities (P-L). The facility is compliant with the zoning designation design standards listed in Section 9-ode, and would maintain compliance upon project implementation. The project site contains various undeveloped vegetation communities and Coast/interior live oak and California black oak trees. A portion of the project is proposed to be located within natural undisturbed habitat, which may result in impacts to sensitive and regulated resources such as sensitive vegetation communities, rare plants, special-status wildlife, nesting birds, oak trees, landmark trees, and aquatic resources. Although there would be some disturbance of natural undisturbed habitat, including permanent impacts to 0.09 acres of vegetation communities and potential removal of individual oak trees, the project site is situated at the junction of the existing developed Treatment Plant and a relatively small portion of the adjacent natural habitat. Under existing conditions, the wastewater treatment facility is developed with As such, the proposed project, including the highly localized disturbances adjacent to the existing Treatment Plant, would not constitute a substantial degradation of the existing visual character or quality and impacts would be less than significant. d) Would the project create a new source of substantial light or glare which would adversely affect day or nighttime views in the area? No Impact. Construction of the project would occur between the hours of 7:00 a.m. and 7:00 p.m. As such, no lighting would be needed for construction of the project. The project would not include any lighting components during operation and visible project components would be constructed of non-reflective materials such as concrete and concrete blocks. As such, the project would have no impact related to creation of a new source of light and glare.

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 16 FEBRUARY 2025

3.2 Agriculture and Forestry Resources Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact II. AGRICULTURE AND FORESTRY RESOURCES In determining whether impacts to agricultural resources are significant environmental effects, lead agencies may refer to the California Agricultural Land Evaluation and Site Assessment Model (1997) prepared by the California Dept. Conservation as an optional model to use in assessing impacts on agriculture and farmland. In determining whether impacts to forest resources, including timberland, are significant environmental effects, lead agencies may refer to information compiled by the California Department of Forestry and Fire Protection regarding the Sforest land, including the Forest and Range Assessment Project and the Forest Legacy Assessment project; and forest carbon measurement methodology provided in Forest Protocols adopted by the California Air Resources Board. Would the project: a) Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non-agricultural use? b) Conflict with existing zoning for agricultural use, or a Williamson Act contract? c) Conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public Resources Code section 12220(g)), timberland (as defined by Public Resources Code section 4526), or timberland zoned Timberland Production (as defined by Government Code section 51104(g))? d) Result in the loss of forest land or conversion of forest land to non-forest use? e) Involve other changes in the existing environment which, due to their location or nature, could result in conversion of Farmland, to non-agricultural use or conversion of forest land to non-forest use? a) Would the project convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non-agricultural use? No Impact. The project site and its vicinity is not located on Prime Farmland, Unique Farmland, or Farmland of Statewide Importance, as mapped by the Farmland Mapping and Monitoring Program (CDOC 2022). The site has a farmland designation of Urban and Built-Up Land (CDOC 2022). Therefore, the proposed project would not convert farmland to non-agricultural uses and there would be no impact.

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 17 FEBRUARY 2025
b) Would the project conflict with existing zoning for agricultural use, or a Williamson Act contract? No Impact. The project site is not zoned for agricultural use. The site has a zoning designation of Public, Quasi-Public, and Institutional Lands and Facilities (P-L). The project site is on publicly owned land that is not under a Williamson Act contract and would not be suitable for agricultural preservation. Therefore, the proposed project would not conflict with zoning for agricultural use or a Williamson Act contract, and there would be no impact. c) Would the project conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public Resources Code section 12220(g)), timberland (as defined by Public Resources Code section 4526), or timberland zoned Timberland Production (as defined by Government Code section 51104(g))? No Impact. As previously mentioned, the project site is zoned for Public, Quasi-Public, and Institutional Lands and Facilities (P-L) in the City. Section 9-land, timberland, or timberland production. As such, the project would not conflict with existing zoning or cause rezoning of forest land, timberland, or timberland production. There would be no impact. d) Would the project result in the loss of forest land or conversion of forest land to non-forest use? No Impact. As previously stated, the project site does not contain forest land. Additionally, the project site is an operating wastewater Treatment Plant under existing conditions. As such, the project would not result in the loss of forest land or conversion of forest land to non-forest use. There would be no impact. e) Would the project involve other changes in the existing environment which, due to their location or nature, could result in conversion of Farmland, to non-agricultural use or conversion of forest land to non-forest use? No Impact. As previously stated, the project site does not contain farmland or forest land. Additionally, the project site is an operating wastewater Treatment Plant under existing conditions. As such, the project would not result in the loss of forest land or conversion of farmland to non-agricultural use forest land to non-forest use. There would be no impact. 3.3 Air Quality Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact III. AIR QUALITY Where available, the significance criteria established by the applicable air quality management district or air pollution control district may be relied upon to make the following determinations. Would the project: a) Conflict with or obstruct implementation of the applicable air quality plan?

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 18 FEBRUARY 2025
Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact b) Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or State ambient air quality standard? c) Expose sensitive receptors to substantial pollutant concentrations? d) Result in other emissions (such as those leading to odors) adversely affecting a substantial number of people? The analysis presented in this section is based upon information found in the Ventura County Air Quality Assessment Guidelines, adopted by the Ventura County Air Pollution Control District (VCAPCD) in 2003. The VCAPCD is required to monitor air pollutant levels to ensure National Ambient Air Quality Standards (NAAQS) and California Ambient Air Quality Standards (CAAQS) are met. If the standards are met, then the bIf the standards are not met, then the basin is clto develop strategies to meet the standards. According to the California Air Resources Board (CARB) Area Designation Maps, the project site is in a region identified as being in nonattainment for ozone (O3) NAAQS and CAAQS and for particulate matter less than 10 microns in diameter (PM10) CAAQS (CARB 2022a). a) Would the project conflict with or obstruct implementation of the applicable air quality plan? Less-than-Significant Impact. The project site is located in the South-Central Coast Air Basin (SCCAB), which covers Ventura, Santa Barbara, and San Luis Obispo Counties. The VCAPCD monitors and regulates the local air quality in the County and manages the Air Quality Management Plan (AQMP). A project is non-conforming with an air quality plan if it conflicts with or delays implementation of any applicable attainment or maintenance plan. A project is conforming if it complies with all applicable VCAPCD rules and regulations, complies with all proposed control measures that are not yet adopted from the applicable plan, and is consistent with the growth forecasts in the applicable plan (or is directly included in the applicable plan). Zoning changes, specific plans, general plan amendments, and similar land use plan changes that do not increase dwelling unit density, do not increase vehicle trips, and do not increase vehicle miles traveled (VMT) are also deemed to comply with the applicable air quality plan (VCAPCD 2003). Consistency with land use and population forecasts in local and regional plans, including the AQMP, is required under CEQA for all projects. The VCAPCD further describes consistency with the AQMP for projects subject to these guidelines, which means that direct and indirect emissions associated with a project are adopted in the AQMP. The 2022 AQMP was adopted by the VCAPCD Board on December 13, 2022, and is the most recent applicable air quality plan. The 2022 AQMP is the 3-year update required by the State to show how VCAPCD plans to meet the 2015 federal 8-hour O3 standard (VCAPCD 2022).

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 19 FEBRUARY 2025
The AQMP relies primarily on the land use and population projections provided by the Southern California Association of Governments (SCAG) and the CARB on-road emissions forecast as a basis for vehicle emission forecasting. The current General Plan land use for the project site is Institutional and the zoning is Public, Quasi-Public, and Institutional Lands and Facilities (P-L). The project would occur entirely within the existing Treatment Plant property and does not propose changing the existing zoning or land use designations in the project area. Accordingly, the project is consistent with the SCAG Regional Transportation Plan (RTP)/Sustainable Communities Strategy (SCS) forecasts used in the VCAPCD 2022 AQMP development. As a result, the project would not conflict with or obstruct implementation of the AQMP, and associated potential impacts would be less than significant. b) Would the project result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or State ambient air quality standard? Less-than-Significant Impact. Air pollution is largely a cumulative impact. The nonattainment status of regional pollutants is a result of past and present development, and VCAPCD develops and implements plans for future attainment of ambient air quality standards. Based on these considerations, project-level individual emissions would have a cumulatively significant impact on air quality. Construction Emissions Proposed construction activities would result in the temporary addition of pollutants to the local airshed caused by on-site sources (i.e., off-road construction equipment, soil disturbance, and reactive organic compound [ROC] off-gassing) and off-site sources (i.e., on-road haul trucks, vendor trucks, and worker vehicle trips). Construction emissions can vary substantially from day to day, depending on the level of activity; the specific type of operation; and, for particulate matter, the prevailing weather conditions. Therefore, such emission levels can only be approximately estimated. Emissions from the construction phase of the project were estimated using the California Emissions Estimator Model (CalEEMod), Version 2022.1.1.7. For the purposes of modeling, it was assumed that construction of the project would commence in January 20251 and would last approximately 6 months, ending in June 2025. The analysis contained herein is based on the following schedule assumptions (duration of phases is approximate): Site Preparation and Vegetation Removal: January 2025February 2025 (1.5 months) Demolition: January 2025February 2025 (1 month) Grading: March 2025April 2025 (1 month) Basin Construction: April 2025June 2025 (2.5 months) Storm Drain/Outlet Pipe Construction: May 2025June 2025 (1.5 months) Paving (Trench Repair and Patching): June 2025 (1 month) 1 The analysis assumes a construction start date of January 2025, which represents the earliest year construction would initiate. Assuming the earliest start year for construction represents the worst-case scenario for criteria air pollutant emissions because equipment and vehicle emission factors for later years would be slightly less due to more stringent standards for in-use off-road equipment and heavy-duty trucks, as well as fleet turnover replacing older equipment and vehicles in later years.

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The anticipated construction scenario assumptions, including phase type and duration, vehicle trips, and equipment mix, used for estimating the construction emissions of the project are based on information provided by the project engineering team and are shown in Table 3-1. Detailed construction equipment modeling assumptions are provided in Appendix A, Air Quality, Greenhouse Gas Emissions, Energy Calculations. Table 3-1. Construction Scenario Assumptions Construction Phase Average Daily One-Way Vehicle Trips Equipment Workers Vendor Trucks Haul Trucks Equipment Type Quantity Usage Hours Demolition 8 4 4 Concrete/ Industrial Saws 1 8 Excavators 1 8 Tractors/Loaders/ Backhoes 1 8 Site Preparation and Vegetation Removal 6 4 2 Tractors/Loaders/ Backhoes 2 8 Grading 10 4 2 Excavators 1 8 Graders 1 8 Tractors/Loaders/ Backhoes 2 8 Basin Construction 8 2 0 Excavators 2 8 Graders 1 8 Tractors/Loaders/ Backhoes 2 8 Storm Drain/Outlet Pipe Construction Excavators 1 8 Graders 1 8 16 2 0 Rough Terrain Forklifts 1 8 Tractors/Loaders/ Backhoes 1 8 Paving 8 2 0 Pavers 1 8 Rollers 1 8 Tractors/Loaders/ Backhoes 1 8 Note: See Appendix A for details. For the analysis, it was assumed that heavy construction equipment would be operating 5 days per week (22 days per month) during project construction. During demolition, the project would result in approximately 215 tons of demolition material. During the grading phase, project construction would include approximately 165 cubic yards of export. Construction worker trips were based on CalEEMod default assumptions and rounded up to the nearest whole number to account for whole round trips. Vendor trucks reflect either water trucks for fugitive dust control or material delivery. The project would be required to comply with VCAPCD Rule 55 to control dust emissions generated during any dust-generating activities. Standard construction practices that would be employed to reduce fugitive

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dust emissions include watering of the active dust areas two times per day, with additional watering depending on weather conditions. Table 3-2 presents the estimated maximum daily emissions generated during construction of the project . Table 3-2. Estimated Maximum Daily Construction Criteria Air Pollutant Emissions Year ROC NOx CO SOx PM10 PM2.5 Pounds per Day 2025 1.98 17.00 25.30 0.03 1.20 0.79 Maximum Daily Emissions 1.98 17.00 25.30 0.03 1.20 0.79 VCAPCD Threshold 25 25 Threshold Exceeded? No No Notes: ROC = reactive organic compound; NOx = oxides of nitrogen; CO = carbon monoxide; SOx = sulfur oxides; PM10 = particulate matter less than 10 microns; PM2.5 = particulate matter less than 2.5 microns; = not available or applicable. Results See Appendix A for complete results. As shown in Table 3-2, project construction would not exceed 25 pounds per day of ROC or oxides of nitrogen (NOx) guidelines, construction-related impacts would be less than significant. Operational Emissions Once project construction is complete, the project would continue providing stormwater management for the City. Similar to existing conditions, staff would occasionally visit the project site for routine maintenance or in the event of an emergency; however, no net increase in operational activities associated with the project would occur (e.g., no routine daily equipment operation, vehicle trips, or energy use would be required). Because the project would not result in a net increase in long-term operational activities, there would be no potential air quality impacts associated with operational air pollutant emissions. Conclusion Based on the previous considerations, the project would not result in a cumulatively considerable increase in emissions of nonattainment pollutants, and cumulative impacts would be less than significant. c) Would the project expose sensitive receptors to substantial pollutant concentrations? Less-than-Significant Impact. Sensitive Receptors Sensitive receptors are those individuals more susceptible to the effects of air pollution than the population at large. People most likely to be affected by air pollution include children, the elderly, and people with cardiovascular and chronic respiratory diseases. The VCAPCD identifies sensitive receptors as facilities or land uses that include members of the population that are particularly sensitive to the effects of air

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 22 FEBRUARY 2025
pollutants, such as children, the elderly, and people with illnesses. Examples include schools, hospitals, and daycare centers (VCAPCD 2003). Sensitive receptors in the vicinity of the project site consist of residential land uses (single-family and multifamily residences to the south and southeast) and the closest receptors are residences located approximately 1,700 feet south of the proposed improvements. These sensitive receptors represent the nearest sensitive land uses with the potential to be impacted by construction of the project. Other sensitive receptors are located farther away from the project site and would be less affected by on-site emissions. Health Impacts of Toxic Air Contaminants In addition to impacts from criteria pollutants, project impacts may include emissions of pollutants identified by the State and federal government as toxic air contaminants (TACs) or hazardous air pollutants. A substance is considered toxic if it has the potential to cause adverse health effects in humans, including increasing the risk of cancer upon exposure or acute (immediate) and/or chronic (cumulative) non-cancer health effects. A toxic substance released into the air is considered a TAC. Adverse health effects associated with exposure to TACs may include carcinogenic (i.e., cancer-causing) and noncarcinogenic effects. Noncarcinogenic effects typically affect one or more target organ systems and may be experienced on either short-term (acute) or long-term (chronic) exposure to a given TAC. generally more stringent than the federal program and aimed at TACs that are a problem in California. The State has formally identified more than 200 substances as TACs, including the federal hazardous air pollutants, and has adopted appropriate control measures for sources of these TACs. Health effects from carcinogenic air toxics are usually described in terms of cancer risk. The VCAPCD recommends an incremental cancer risk threshold of 10 in a million (VCAPCD 2003). net increased likelihood that a person continuously exposed to concentrations of TACs resulting from a project over a 9-, 30-, and 70-year exposure period will contract cancer based on the use of standard Office of Environmental Health Hazard Assessment risk-assessment methodology. The greatest potential for TAC emissions during construction would be from diesel particulate matter (DPM) emissions, which are characterized as a TAC by the State of California, from heavy equipment operations and on-site heavy-duty trucks during construction of the project. DPM has established cancer risk factors and relative exposure values for long-term chronic health hazard impacts; however, no short-term, acute relative exposure level has been established for DPM. The following measures are required by State law to reduce DPM emissions: Fleet owners of mobile construction equipment are subject to the CARB Regulation for In-use Off-road Diesel Vehicles (13 CCR 2449), the purpose of which is to reduce DPM and criteria pollutant emissions from in-use (existing), off-road, diesel-fueled vehicles. All commercial diesel vehicles are subject to Title 13, Section 2485 of the California Code of Regulations, limiting engine idling time. Idling of heavy-duty diesel construction equipment and trucks during loading and unloading shall be limited to 5 minutes; electric auxiliary power units should be used whenever possible.

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 23 FEBRUARY 2025
Total project construction would last approximately 6 months, after which project-related TAC emissions would cease. A 6-month construction schedule represents a short duration of exposure (1.7% of a 30-year exposure period), while cancer and chronic risk from DPM are typically associated with long-term exposure. Thus, the project would not result in a long-term source of TAC emissions. In addition, the project would not require the extensive operation of heavy-duty diesel construction equipment, which is subject to a CARB Airborne Toxics Control Measure for in-use diesel construction equipment to reduce DPM emissions and would not involve extensive use of diesel trucks, which are also subject to a CARB Airborne Toxics Control Measure. Furthermore, as shown in Table 3-2, maximum daily particulate matter (i.e., PM10 or PM2.5) emissions generated by construction equipment operation and haul-truck trips during construction (exhaust particulate matter or DPM), combined with fugitive dust generated by equipment operation and vehicle travel, is minimal. Of importance, the closest sensitive receptors to the project are single-family residences located approximately 1,700 feet south, which is a substantial distance between the sources and receptors, whereas potential generation of TAC emissions is anticipated to be largely dispersed. As such, the potential for the project to result in a long-term exposure of receptors to TACs is limited. Therefore, the exposure of project-related TAC emission impacts to sensitive receptors would be less than significant. No residual TAC emissions and corresponding health risk are anticipated after construction, and no long-term sources of TAC emissions are anticipated during operation of the project. CARB has published the Air Quality and Land Use Handbook: A Community Health Perspective (CARB 2005), which identifies certain types of facilities or sources that may emit substantial quantities of TACs and therefore could conflict with s, nursing Air Quality and Land Use Handbook is a guide for siting of new sensitive land uses, and CARB recommends that sensitive receptors not be located downwind or in proximity to such sources to avoid potential health hazards. Of note, the project is not considered an air quality sensitive receptor. The enumerated facilities or sources include the following: high-traffic freeways and roads, distribution centers, railyards, ports, refineries, chrome plating facilities, dry cleaners, and large gas-dispensing facilities. The project would not include any of the above-listed land uses associated with generation of TAC emissions. Potential impacts associated with exposure of sensitive receptors to TACs would be less than significant. It is expected that operation of the project would not result in any non-permitted direct emissions (e.g., those from a point source such as diesel generators) that could be a TAC source and, as discussed previously, is not anticipated to result in any operational activity, including diesel vehicle travel. Therefore, the project would not result in exposure of sensitive receptors in the vicinity of the project site to substantial TAC concentrations due to either construction or operation and impacts would be less than significant. Health Impacts of Carbon Monoxide Mobile-source impacts occur on two basic scales of motion. Regionally, project-related travel would add to regional trip generation and increase the VMT within the local airshed and the basin. Locally, project-related - -inefficient speeds, and operates on roadways already crowded with non-project traffic, then there is a potential for the formation of microscale carbon monoxide (CO) hotspots in the area immediately around points of congested traffic.

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 24 FEBRUARY 2025
Because of continued improvement in mobile emissions at a rate faster than the rate of vehicle growth and/or congestion, the potential for CO hotspots in the basin is steadily decreasing. The VCAPCD recommends conducting a CO hotspot screening analysis using the California Department of Caltrans) CO Protocol for any project that meets both of the following conditions: 1. The project would generate indirect CO emissions are greater than the applicable ozone project significance thresholds (i.e., 25 pounds per day). 2. The project would generate traffic that would significantly impact congestion levels at roadway intersections currently operating at, or that are expected to operate at, LOS [level of service] E or F. Caltrans CO Protocol is intended to address operational CO impacts. Because the project would not result in operational vehicle trips, the project would not affect congestion levels at roadway intersections. As a result, the project does not trigger the need for a CO hotspot analysis and would not cause or contribute to a CO hotspot. Regarding construction traffic CO emissions, the project would generate minimal traffic during construction. The project would add up to eight one-way truck trips per day during the demolition phase and up to 16 one-way worker trips during the storm drain/outlet pipe construction phase; all other phases would be fewer trips per day. Per the Caltrans CO Protocol, that level of traffic would not meet the criteria for worsening air quality and causing a CO hotspot (Caltrans 2010). Therefore, the project would not expose sensitive receptors to substantial CO concentrations and impacts would be less than significant. Health Effects of Other Criteria Air Pollutants Construction of the pany criteria air pollutants and the project is not anticipated to result in operational activity that would generate criteria air pollutant emissions. Regarding ROCs, the majority of construction-related ROCs are associated with motor vehicles, construction equipment, and pavement off-gassing, and the associated In addition, ROC and NOx are precursors to O3, for which the SCCAB is designated as attainment with respect to the NAAQS and CAAQS. The health effects associated with O3 are generally associated with reduced lung function. The contribution of ROCs and NOx to regional ambient O3 concentrations is the result of complex photochemistry. The increases in O3 concentrations in the SCCAB due to O3 precursor emissions tend to be found downwind from the source location to allow time for the photochemical reactions to occur. However, the potential for exacerbating excessive O3 concentrations would also depend on the time of year that the ROC emissions would occur, because exceedances of the O3 ambient air quality standards tend to occur between April and October when solar radiation is highest. Regarding nitrogen dioxide (NO2), according to the construction emissions analysis, construction of the project would not contribute to exceedances of the NAAQS and CAAQS for NO2. Health effects from exposure to NO2 and NOx are associated with respiratory irritation, which could be experienced by nearby receptors during the periods of heaviest use of off-road construction equipment; however, nearby receptors are more than 1,700 feet from project construction activity, so any localized effects are unlikely and construction equipment operation would be short term. Additionally, off-road construction equipment would operate at

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various portions of the site and would not be concentrated in one portion of the site at any one time. Construction of the project would not require any stationary emission sources that would create substantial, localized NOx impacts. CO tends to be a localized impact associated with congested intersections and the most common effects of CO exposure are fatigue, headaches, confusion and reduced mental alertness, light-headedness, and dizziness due to inadequate oxygen delivery to the brain. The associated CO hotspots were discussed previously as a less-than-significant impact. Health effects associated with PM10 or PM2.5 depending on short- or long-term exposure include premature mortality, increased hospital admissions for heart or lung causes, acute and chronic bronchitis, asthma attacks, emergency room visits, respiratory symptoms, restricted activity days, and reduced lung function growth in children. Construction of the project would not exceed thresholds for PM10 or PM2.5 and would not contribute to exceedances of the NAAQS and CAAQS for particulate matter. Based on the preceding considerations, health impacts associated with criteria air pollutants would be less than significant. Valley Fever San Joaquin Valley Fever (formally known as coccidioidomycosis) is an infectious disease caused by the fungus Coccidioides immitis. Valley Fever is a disease of concern in the SCCAB. Infection is caused by inhalation of Coccidioides immitis spores that have become airborne when dry, dusty soil or dirt is disturbed by natural processes, such as wind or earthquakes, or by human-induced ground-disturbing activities, such as construction, farming, or other activities (VCAPCD 2003). The Valley Fever fungal spores are too small to be seen by the naked eye, and there is no reliable way to test the soil for spores before working in a particular place. Per the California Department of Public Health, the range over 8 years (20122020) for coccidioidomycosis cases in the County is 4.643.9 cases per 100,000 people per year. Statewide incidences in 2020 were 18.1 per 100,000 people (CDPH 2020). As such, it is considered endemic to the County. The California Department of Industrial Relations Division of Occupational Safety and Health, better known as Cal/OSHA, has oversight for Valley Fever regulations as they pertain to workers with potential exposure. Applicable regulations regarding Valley Fever protection and exposure can be found in the California Code of Regulations, Title 8. Construction employers must train workers on Valley Fever prevention in counties where Valley Fever is considered endemic, which includes the County. The project would disturb a portion of undisturbed land, with other portions within the existing built and/or paved area; it is not anticipated to result in substantial ground disturbance or fugitive dust impacts. The project would comply with VCAPCD Rule 55, which would limit fugitive dust, which can be a source of Valley Fever. Additionally, fugitive dust impacts are highly localized and would not affect off-site receptors. The primary concern for impacts would be to construction workers. Project construction would be subject to Cal/OSHA requirements which prescribe measures that would be applicable to minimize release of potential Valley Fever spores. Based on compliance with applicable regulatory measures, impacts associated with Valley Fever would be less than significant.

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Conclusion Based on the previous considerations, the project would not expose sensitive receptors to substantial pollutant concentrations and impacts would be less than significant. d) Would the project result in other emissions (such as those leading to odors) adversely affecting a substantial number of people? Less-than-Significant Impact. Based on available information, the project is not anticipated to result in other emissions that have not been addressed under Thresholds 3.3(a) through 3.3(c), above. As such, this analysis focuses on the potential for the project to generate odors. The occurrence and severity of potential odor impacts depend on numerous factors. The nature, frequency, and intensity of the source; wind speed and direction; and the sensitivity of receiving location each contribute to the intensity of the impact. Although offensive odors seldom cause physical harm, they can be annoying, cause distress among the public, and generate citizen complaints. Construction Emissions During project construction, exhaust from equipment may produce discernible odors typical of most construction sites. Potential odors produced during construction would be attributable to concentrations of unburned hydrocarbons from tailpipes of construction equipment. However, such odors would disperse rapidly from the project site and generally occur at magnitudes that would not affect substantial numbers of people. Therefore, impacts associated with odors during construction would be less than significant. Operational Emissions Land uses and industrial operations associated with odor complaints include agricultural uses, wastewater treatment plants, food-processing plants, chemical plants, composting, refineries, landfills, dairies, and fiberglass molding (VCAPCD 2003). The project includes improvements to the Treatment Plant, including the development of a new debris basin and storm drain improvements, which would not create new sources of odor during operation. Therefore, project operations would result in an odor impact that is less than significant.

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3.4 Biological Resources Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact IV. BIOLOGICAL RESOURCES Would the project: a) Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? c) Have a substantial adverse effect on State or federally protected wetlands (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? d) Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? e) Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? f) Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or State habitat conservation plan? 3.4.1 Environmental Setting Existing Conditions The following discussion is based on the Biological Resources Assessment Report for the Hill Canyon Treatment Plant Stormwater Diversion Project (BRAR) (Appendix B1; September 2022) and the Aquatic Resources Delineation Report (ARDR) (Appendix B2; September 2022). The BRAR was prepared to identify existing conditions, potential

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for sensitive biological resources to occur, impacts, and recommend measures to avoid and minimize impacts to biological resources within an adjacent the project. The ARDR was prepared to identify and map existing aquatic resources potentially subject to the regulatory jurisdiction of the USACE pursuant to Section 404 of the Clean Water Act (33 USC 1344), RWQCB pursuant to Section 401 of the Clean Water Act and the Porter-Cologne Water Quality Control Act, and/or CDFW pursuant to Section 1602 of the California Fish and Game Code (CFGC; collectively defined as jurisdictional aquatic resources). As part of the BRAR, Dudek biologist Melissa Blundell visited the site on February 8 and 17, 2021, to perform a biological site visit. During the visit, Ms. Blundell walked and examined areas within the Biological Survey Area (BSA), which included the project boundary and a 100-foot buffer. During the visit, Ms. Blundell mapped vegetation communities and used a GPS unit to delineate the located and boundaries of any potentially sensitive biological resources. Dudek biologist Heather Moine visited the site on March 21, 2022, primarily to perform an aquatic resources delineation survey and rare plant survey. Supplemental vegetation and oak tree mapping was also performed, which provided supplemental information related to slight project footprint changes and vegetation mapping refinement. Vegetation Communities and Land Covers A total of six vegetation communities and/or land cover types were mapped with the BSA as shown in Figure 5, Vegetation Communities and Land Cover Types. All four of the mapped vegetation communities are considered sensitive. Table 3-3 below lists descriptions of each of the vegetation community and land cover types within the BSA. Table 3-3. Vegetation and Land Cover Types within the BSA General Habitat Vegetation Community Global, State Ranka CDFW Sensitiveb Acres Native Scrub California brittle bushCalifornia sagebrush scrub Association G3 Y 0.08 ChamiseBlack sageSugarbush scrub Association G3, S3 Y 0.11 Lemonade berry scrub Alliance G3, S3 Y 0.44 Lemonade berry scrubCalifornia sage scrub Association Y 1.56 Other Land Cover Types Developed N/A N 2.87 Disturbed N/A N 0.30 Total 5.36 Notes: BSA = Biological Survey Area; CDFW = California Department of Fish and Wildlife; Y = yes; N/A = not applicable; N = no. G3 and S3 are ranks considered vulnerable. a For alliances with State Ranks of S1 to S3, all associations within them are considered highly imperiled. A question mark (?) denotes an inexact numeric rank due to insufficient samples over the full expected range of the type, but existing information points to this rank (CDFW 2022a). bSensitive based on CDFW (2022a). However, communities determined to not be sensitive may still be sensitive under local policies or provide suitable habitat for special-status plant and wildlife species.

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Native Scrub California Brittle BushCalifornia Sagebrush Scrub Association is considered vulnerable (G3) and a sensitive vegetation community by CDFW (2022a). Within this association, California brittle bush and California sagebrush are co-dominant in the shrub layer. Some plant species associated with this association include coyote brush (Baccharis pilularis), California buckwheat (Eriogonum fasciculatum), deer weed (Acmispon glaber), laurel sumac (Malosma laurina), lemonade berry, sage species (Salvia spp.), and blue elderberry (Sambucus mexicana). This scrub community provides suitable cover, nesting, and foraging opportunities for commonly occurring wildlife species, as described under ChamiseBlack SageSugarbush Scrub Association. In addition, the federally listed coastal California gnatcatcher is strongly associated with sage scrub habitats. Approximately 0.08 acres of this community was mapped near the proposed debris basin in the western portion of the BSA as shown in Figure 5. ChamiseBlack SageSugarbush Scrub Association is considered vulnerable (G3, S3) and a sensitive vegetation community by CDFW (2022a). Within this association, chamise and black sage are co-dominant in the shrub layer with sugarbush (Rhus ovata) present at lower cover. Some plant species typically associated with the alliance level include Arctostaphylos spp., California sagebrush, ceanothus (Ceanothus spp.), California buckwheat, laurel sumac, hollyleaf redberry (Rhamnus ilicifolia), and sugarbush (Sawyer et al. 2009). This scrub community provides suitable cover, nesting, and foraging opportunities for commonly occurring birds such as house finch (Haemorhous mexicanusCalypte anna), northern mockingbird (Mimus polyglottos), California towhee (Melozone crissalis), and wrentit (Chamaea fasciata); common mammals, such as rabbits and mice; and common reptile species, such as western fence lizard (Sceloporus occidentalis). Approximately 0.11 acres of this community was mapped near the proposed debris basin in the northeastern portion of the BSA as shown in Figure 5. Lemonade Berry Scrub Alliance is considered vulnerable (G3, S3) and a sensitive vegetation community by CDFW (2022a). Within this association, lemonade berry is dominant in the shrub layer. Some plant species associated with this alliance include California sagebrush, bush monkeyflower (Diplacus aurantiacus), California brittle bush, buckwheat species (Eriogonum spp.), toyon, sage species, and blue elderberry. Wildlife found in lemonade berry scrub is similar to that found in ChamiseBlack SageSugarbush Scrub Association. Approximately 0.44 acres of lemonade berry scrub was mapped near the manhole work area and proposed debris basin in the southern and western portions of the BSA, respectively, as shown in Figure 5. Lemonade Berry ScrubCalifornia Sagebrush Association is considered a sensitive vegetation community by CDFW (2022a). Within this association, lemonade berry and California sagebrush are co-dominant in the shrub layer. This association contains a similar composition and similar species as found with lemonade berry scrub. In addition, the federally listed coastal California gnatcatcher is strongly associated with sage scrub habitats. Approximately 1.56 acres of the Lemonade Berry ScrubCalifornia Sagebrush Association was mapped near the proposed debris basin in the western portion of the BSA as shown in Figure 5. Other Land Cover Types Developed areas are not listed in CDFW (2022a) and are not considered sensitive. Developed land refers to areas that have been constructed upon or otherwise physically altered to the extent that native vegetation communities are not supported. Developed areas are characterized by permanent or semi-permanent structures, hardscapes, and landscaped areas that require irrigation. Within the BSA, approximately 2.87 acres are mapped as developed areas, which include the entire Treatment Plant, including buildings, landscaping, access roads, and parking areas. Most of the developed areas in the BSA lack any vegetation to provide cover, feeding, or nesting opportunities for

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wildlife species. Limited ornamental landscaping may provide some temporary cover or nesting opportunities for common urban-adapted bird and reptile species. Disturbed areas are not listed in CDFW (2022a) and are not considered sensitive. Disturbed habitat refers to areas where soils have been recently or repeatedly disturbed by grading, compaction, or clearing of vegetation. Structures are typically not present within disturbed habitats, and these areas provide relatively low value for most plant and wildlife species. Within the BSA, approximately 0.30 acres of disturbed habitat occurs adjacent to the existing Treatment Plant near the proposed debris basin, along an access road near the manhole work area and near existing equipment adjacent to the manhole work area, as shown in Figure 5. Disturbed areas provide very limited to no cover for birds, reptiles, and small mammals as they traverse between more suitable habitats, and very minimal to no food resources. Soils Soils within the natural landscape of the BSA consist mainly of Hambright very rocky loam (HaG; 15% to 75% slopes), a shallow, well-drained soil that typically occurs on plateaus, basalt flows, and hillslopes (USDA-NRCS 2022a). Vina gravelly loam (VnC; 2% to 9% slopes) occurs along the northwestern portions of the BSA and primarily within the existing Treatment Plant. A third soil type, Vina loam (VaC; 2 to 9% slopes), also occurs in a portion of the existing Treatment Plant. The Vina soil series consist of very deep, well-drained soils (USDA-NRCS 2022a). These soils are not considered hydric soils (USDA-NRCS 2022b). City-Regulated Trees Section 9-regulation sets forth the policy of the City to require the preservation of all healthy oak trees, unless otherwise exempt and the conforming use of the property justifies removal, cutting, pruning, and/or encroachment into the protected zone of an oak tree. During the reconnaissance survey, approximately 19 oak tree species (Quercus sp.), great than 2 inches in diameter, were documented within the BSA (Figure 6, City-Regulated Trees). The majority of the oak trees were mapped near or within the proposed debris basin and pipeline work areas. Two additional oak trees occurred near, but outside the proposed footprint of, the manhole and inlet work area. Table 3-4 provides a summary of the City-regulated tree species encountered during the reconnaissance survey. Table 3-4. Summary of City-Regulated Tree Species within the BSA Tree No. Tree Species Approximate Diameter (inches)a 1 Coast/interior live oak 18, 17.5 3 Coast/interior live oak 35 4 Coast/interior live oak 20.8, 37.5 fused 5 Coast/interior live oak 16.2 6 Coast/interior live oak 7, 4, 5 7 Coast/interior live oak 14 8 Coast/interior live oak 9.3, 11 9 California black oak >2 10 Coast/interior live oak 28.7 11 Coast/interior live oak 39 12 Coast/interior live oak 8.8

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Table 3-4. Summary of City-Regulated Tree Species within the BSA Tree No. Tree Species Approximate Diameter (inches)a 13 Coast/interior live oak 8 14 Coast/interior live oak 14.5, 12.9, 13 15 Coast/interior live oak 17 16 Coast/interior live oak 7.1 17 Coast/interior live oak 8.1 18 Coast/interior live oak 8.8 19 Coast/interior live oak 8.7 20 Coast/interior live oak 26.7 Notes: BSA = Biological Survey Area. a Multiple measurements provided for multi-branched individuals. Measured at 4.5 feet above base of tree. Common Plant and Wildlife Species A total of 112 plant species were documented. In all, 72 (64%) were native and 40 (36%) were non-native. One special-status plant species, Conejo dudleya (Dudleya parva), was observed and is discussed further below. A total of 22 common wildlife species were observed during the site visit, including 1 reptile, 19 birds, and 2 mammals. Woodrat middens (presumably from the desert woodrat [Neotoma lepida ssp. intermedia], a CDFW SSC) were observed throughout the natural areas, and are described further below. Although ground squirrels (Otospermophilus beecheyi) were observed, areas of significant burrowing were not. In addition, one bird species, oak titmouse (Baeolophus inornatus), a U.S. Fish and Wildlife Service (USFWS) Bird of Conservation Concern, was observed. No fish or amphibians were observed during the field survey and the BSA lacks suitable aquatic habitat to support these species. Special-Status Plants and Wildlife Special-Status Plant Species The literature and database views resulted in 60 special-status plant species that have been documented in the nine U.S. Geological Survey 7.5-minute quadrangles surrounding the panalysis and rare plant surveys performed in 2022, 1 of the 60 special-status plant species, Conejo dudleya, was observed during the 2022 seasonally timed rare plant surveys. Table 3-5 provides a description of this special-status plant species. The remaining 59 species are considered to have a low potential or not expected to occur. Several species are considered to have low to no potential to occur primarily due to the lack of observations within the BSA during the 2022 focused surveys.

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Table 3-5. Special-Status Plant Species Observed within the Biological Survey Area Scientific Name Common Name Status (Federal/ State/ CRPR)a Primary Habitat Associations/Life Form/Blooming Period/Elevation Range (feet) Potential to Occur in the Biological Survey Area (BSA) Dudleya parva Conejo dudleya FT/None/1B.2 Coastal scrub, valley and foothill grassland; clay (sometimes), gravelly (sometimes), rocky (sometimes), volcanic (sometimes)/ perennial herb/ MayJune/ 1951,475 Observed. This species was observed during 2022 rare plant surveys. Approximately 151 individuals were observed along the southeastern edge of the BSA, with the closest observations to impact areas about 25 feet uphill from the proposed debris basin. Suitable coastal scrub habitat and rocky, gravelly substrate are present to support this species within the BSA. Regionally, there are two occurrences observed in 2010 that are both mapped approximately 0.6 miles southeast of the project site (CDFW 2022b). In addition, there are numerous occurrences within 5 miles of the project site (CDFW 2022b). Note: a The federal and State status of species is based on the Special Vascular Plants, Bryophytes, and Lichens List (CDFW 2022c). Status Designations Federal FT: Federally listed as threatened CRPR: California Rare Plant Rank 1B: Plants rare, threatened, or endangered in California and elsewhere Threat Rank 0.2 Moderately threatened in California (20%80% occurrences threatened/moderate degree and immediacy of threat) Special-Status Wildlife Species The literature and database views resulted in 57 special-status wildlife species that have been documented in the nine U.S. Geological Survey 7.5-minute quadrangles surrounding the panalysis, 6 of the 57 special-status wildlife species are expected to have a moderate to high potential to occur. In addition, direct sign (middens) for desert woodrat was observed within the BSA. Presumably these middens were established by the San Diego desert woodrat (N. lepida intermedia). Table 3-6 provides a description of these 7 special-status species. Table 3-6. Special-Status Wildlife Species Observed or with a Moderate to High Potential to Occur Species Name Common Name Status (Federal/State)a Habitat Potential to Occur in the Biological Survey Area (BSA) Reptiles Anniella spp. California legless lizard None/SSC Coastal dunes, stabilized dunes, beaches, dry washes, valleyfoothill, Moderate potential to occur. Sandy and loose loamy soils present within the BSA may be suitable to support this species. The nearest

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Table 3-6. Special-Status Wildlife Species Observed or with a Moderate to High Potential to Occur Species Name Common Name Status (Federal/State)a Habitat Potential to Occur in the Biological Survey Area (BSA) chaparral, and scrubs; pine, oak, and riparian woodlands; associated with sparse vegetation and moist sandy or loose, loamy soils CNDDB occurrence was documented in 2014 approximately 2.7 miles north of the BSA, where the species was observed in the leaf litter of an avocado orchard across the street from a sandy slope dominated by coastal sage scrub (CDFW 2022b). Aspidoscelis tigris stejnegeri San Diegan tiger whiptail None/SSC Hot and dry areas with sparse foliage, including chaparral, woodland, and riparian areas Moderate potential to occur. Although the nearest CNDDB occurrence is from 2017 and mapped approximately 6.0 miles east of the BSA (CDFW 2022b), vegetated portions of the BSA are contiguous with a larger open space and contain the open scrub and sandy and/or gravel bottom habitats preferred by this species. Phrynosoma blainvillii Blainville's horned lizard None/SSC Open areas of sandy soil in valleys, foothills, and semi-arid mountains including coastal scrub, chaparral, valleyfoothill hardwood, conifer, riparian, pinecypress, juniper, and annual grassland habitats Moderate potential to occur. Sandy and loose loamy soils present within the BSA may be suitable to support this species. In addition, the nearest CNDDB occurrence was observed in an agricultural field set for development in 2007 and mapped approximately 2.7 miles northwest of the BSA (CDFW 2022b). Birds Accipiter cooperii (nesting) Cooper's hawk None/WL Nests and forages in dense stands of live oak, riparian woodlands, or other woodland habitats often near water Moderate potential to nest. The oak trees within the BSA provide suitable nesting substrates for this species. In addition, this species is regularly observed within the surrounding open space, including Wildwood Regional Park (eBird 2022), where there are abundant prey resources available for this species. Aimophila ruficeps canescens Southern California rufous-crowned sparrow None/WL Nests and forages in open coastal scrub and chaparral with low cover of scattered scrub interspersed Moderate potential to occur. Suitable scrub and chaparral habitat is present to support this species. In addition, this species is regularly observed within the

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Table 3-6. Special-Status Wildlife Species Observed or with a Moderate to High Potential to Occur Species Name Common Name Status (Federal/State)a Habitat Potential to Occur in the Biological Survey Area (BSA) with rocky and grassy patches surrounding open space, including Wildwood Regional Park (eBird 2022), where there are abundant prey resources available for this species. Polioptila californica californica coastal California gnatcatcher FT, BCC/SSC Nests and forages in various sage scrub communities, often dominated by California sagebrush and buckwheat; generally avoids nesting in areas with a slope of greater than 40%; majority of nesting at less than 1,000 feet above mean sea level Moderate potential to occur. Suitable coastal sage scrub habitat dominated by California sagebrush is present within and adjacent to the BSA to support this species. In addition, the nearest CNDDB occurrence was observed in coastal sage scrub adjacent to a walking trail in 2016 and mapped approximately 0.6 miles southwest of the BSA (CDFW 2022b) and in 2019 approximately 0.9 miles southwest of the BSA (USFWS 2022a), and there are multiple and regularly occurring observations of this species in the adjacent Wildwood Regional Park (eBird 2022). Mammals Neotoma lepida intermedia San Diego desert woodrat None/SSC Coastal scrub, desert scrub, chaparral, cacti, rocky areas Observed. Multiple woodrat middens (Neotoma sp.) were documented throughout the BSA during field surveys. The BSA contains suitable coastal scrub and rocky outcrop habitat. In addition, the nearest documented occurrence was observed on a rocky outcrop in 2016 and is mapped approximately 4.3 miles south of the BSA (CDFW 2022b). Notes: CNDDB = California Natural Diversity Database. a The federal and State status of species is based on the Special Animals List (CDFW 2022d). Status Abbreviations Federal BCC: U.S. Fish and Wildlife Service Bird of Conservation Concern FT: Federally listed as threatened State SSC: California Species of Special Concern WL: California Watch List Species

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Critical Habitat A query of the Information for Planning and Consultation tool (USFWS 2022b) and review of the critical habitat mapper (USFWS 2022bPentachaeta lyonii) critical habitat within 5 miles of the project site; however, no critical habitat is within the project site as shown in Figure 7, USFWS Critical Habitat. Jurisdictional Aquatic Resources Potential jurisdictional aquatic features mapped include a concrete v-ditch, connecting swale, and an ephemeral channel. As described in the ARDR, of these features, only the ephemeral channel is anticipated to require additional permits pursuant to the Porter-Cologne Water Quality Control Act and California Fish and Game Commission for impacts to the channel. However, as recommended in the ARDR, written concurrence from the resource agencies (RWQCB, CDFW, and USACE) on the jurisdictional status for both features is highly recommended. Concrete V-Ditch The concrete v-ditch is an existing stormwater control feature within the Treatment Plant that directs flows to drain-inlets along the v-ditch as shown on Figure 8, Potential Jurisdictional Aquatic Resources. The drain inlets are regularly maintained by Treatment Plant staff as part of storm preparedness activities. These inlets capture storm flows and drain them to the sludge-drying beds as part of the stormwater capture program (Capron 2017; City of Thousand Oaks 2019). Because the flows associated with the v-ditch are currently subject to the adopted Waste Discharge Requirements and National Pollutant Discharge Elimination System permits for the Treatment Plant (Order No. R4-2019-0137, NPDES No. CA0056294), compliance with this existing permit should apply to this feature and further permits are not anticipated to be necessary from the RWQCB. The Treatment Plant had previously attained status as a zero-discharge facility. An IGP NONA was previously granted by the RWQCB, and the City is petitioning to retain this status with site modifications to re-route off-site flows from the natural canyon directly to Arroyo Conejo Creek (Capron 2017; City of Thousand Oaks 2019). In addition, the concrete v-ditch is unlikely to be jurisdictional to USACE under the Clean Water Act, as the feature is ephemeral and current flows lack a connection with a traditional navigable water. Similarly, the feature lacks a bed and bank often associated with CDFW jurisdictional rivers, stream, or lakes. Ephemeral Channel A narrow ephemeral channel is present in the BSA within and adjacent to the proposed debris basin, as shown in Figure 8. The channel is located within the natural canyon and extends to the existing concrete v-ditch. This channel is characterized by an ordinary high water mark and a bed, with portions of the channel containing a bank. Blue elderberry is present along this feature, providing limited riparian habitat. In addition, a short 12-foot swale connects the feature in the eastern portion of the BSA. These features are anticipated to be jurisdictional to CDFW and RWQCB. Given that the feature is ephemeral and lacks connection with a traditional navigable water, it is unlikely to be jurisdictional to USACE. Waters of the United States As discussed above, no features within the BSA are anticipated to be waters of the United States and, therefore, are not anticipated to be under the jurisdiction of the USACE. The concrete v-ditch is ephemeral and current flows lack a connection with a traditional navigable water. Additionally, the ephemeral channel does not have direct connection to a traditional navigable water, is characterized by low volume or infrequent flows, and flows through this feature are directed through the existing Treatment Plant.

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Waters of the State Regional Water Quality Control Board The concrete v-ditch and ephemeral channel, as described above, are anticipated to be under the jurisdiction of RWQCB. Therefore, approximately 0.04 acres (534 linear feet) of features are anticipated to be subject to regulation by RWQCB under the Porter-Cologne Water Quality Control Act. Table 3-7 below provides a summary of these features. However, based on existing permits, only the ephemeral channel is anticipated to require permitting for project-related activities. Table 3-7. RWQCB Aquatic Resource Summary for the Biological Survey Area Feature Name Location (Latitude/Longitude; Decimal Degrees) Biological Survey Area (Acres/Linear Feet) Non-Wetland Waters Ephemeral Channel (including top of bank) 34.210854; -118.920971 0.01 acres (530 square feet)/ 219 linear feet Upland Swale 34.210701; -118.920611 <0.01 acres (12 square feet)a/ 12 linear feet Concrete V-Ditch 34.211035; -118.921058 0.02 acres (758 square feet)/ 303 linear feet Riparian Blue Elderberry (outside of ephemeral channel and bank) 34.210892; -118.920957 <0.01 acres (332 square feet)/ 23 linear feetb Totalc 0.04 acres (1,632 square feet)/ 534 linear feetb Notes: a Swale width estimated at 1 foot. bRiparian linear feet not included in total due to overlapping with the ephemeral channel. c Totals may not sum due to rounding. California Department of Fish and Wildlife The ephemeral channel as described above is anticipated to be regulated by CDFW. Since CDFW regulates from bank to bank, certain portions of the BSA where the top of the channel bank extended beyond the ordinary high water mark are subject to regulation by CDFW as streambed. The oak trees adjacent to the channel feature may not be jurisdictional to CDFW (but will require confirmation by CDFW). The oak trees on site and along this channel feature do not readily appear to significantly benefit from the channel flows. The oaks trees near the channel originate uphill from the channel feature on upland slopes. Additionally, based on the surrounding environment, oak trees are scattered throughout the upland slopes and terrain, suggesting that the oaks along the channel would Therefore, the oaks adjacent to the channel are unlikely to be categorized as riparian vegetation that is typically under CDFW jurisdiction. However, one blue elderberry plant is located along the channel and is mapped as riparian under CDFW jurisdiction. Therefore, approximately 0.02 acres (231 linear feet) of features are subject to regulation by CDFW under CFGC Section 1600 et seq. However, the final determination will be made by this responsible agency. The full extent of areas are described in Table 3-8.

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Table 3-8. CDFW Aquatic Resource Summary for the Biological Survey Area Feature Name Biological Survey Area (Acres/Linear Feet) Streambed Ephemeral Channel (including top of bank) 0.01 acres (530 square feet)/ 219 linear feet Upland Swale <0.01 acres (12 square feet)a/ 12 linear feet Riparian Blue Elderberry <0.01 acres (332 square feet)/ 23 linear feetb Totalc 0.02 acres (874 square feet)/ 231 linear feetb Notes: a Swale width estimated at 1 foot. bRiparian linear feet not included in total due to overlapping with the ephemeral channel. c Totals may not sum due to rounding. Wildlife Corridors and Habitat Linkages Wildlife corridors are linear features that connect large patches of natural open space and provide avenues for dispersal or migration of animals and dispersal of plants (e.g., via wildlife vectors). Wildlife corridors contribute to population viability by ensuring continual exchange of genes between populations, which helps maintain genetic diversity. Habitat linkages are small patches that join larger blocks of habitat and help reduce the adverse effects of habitat fragmentation. They serve as connections between habitat patches and help reduce the adverse effects of habitat fragmentation. Although individual animals may not move through a habitat linkage, the linkage is a potential route for gene flow and long-term dispersal. Habitat linkages may serve both as habitat and avenues of gene flow for small animals such as reptiles, amphibians, and rodents. Habitat linkages may be represented by continuous stones for dispersal and movement (especially for birds and flying insects). Wildlife corridors and habitat linkages provide avenues for dispersal or migration of animals that also contribute to population viability in several ways, including the following: Ensuring continual exchange of genes between populations to aid in maintaining genetic diversity Providing habitat for some species Providing access to adjacent habitat areas representing additional territory for foraging and mating Allowing for a greater carrying capacity Providing routes for colonization of habitat lands following local population extinctions or habitat recovery from ecological catastrophes The project is located at the interface of existing development (Treatment Plant) and undeveloped open space. The Treatment Plant is located between two publicly owned open space systems, including Wildwood Regional Park, which is approximately 1,765 acres, and Conejo Canyons Open Space, which is approximately 1,430 acres. In addition, regional habitat connectivity and wildlife corridors are mapped in natural areas surrounding the Treatment Plant (SC Wildlands 2008; CDFW 2022c; Ventura County 2022).

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However, the existing Treatment Plant is fully enclosed with a chain-link fence. Therefore, the Treatment Plant provides no opportunities for wildlife movement and project activities within the Treatment Plant are not expected to affect wildlife corridors. Although the proposed debris basin is located within undeveloped open space, the location and proposed disturbed areas are adjacent to the existing fenced facility (extending out to approximately 47 feet southeast of the fence line). With abundant surrounding open spaces and opportunities for movement, the construction of the debris basin at this location is not anticipated to impede, interfere, or significantly affect wildlife movement, corridors, or linkages. a) Would the project have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? Less-than-Significant Impact with Mitigation Incorporated. The proposed project has the potential to impact candidate, sensitive, or special status species, as discussed below. With the incorporation of mitigation, however, impacts are less than significant. Vegetation Communities Direct Impacts The project will permanently impact approximately 0.09 acres of sensitive vegetation communities. In addition, inadvertent direct (temporary) impacts to sensitive communities may occur if construction activities accidentally trim, clear, trample, or grade sensitive vegetation communities outside of the proposed work areas (i.e., permanent impact areas). Impacts to sensitive vegetation communities are considered potentially significant. However, implementation of Mitigation Measures (MMs) MM-BIO-1 (Habitat Mitigation and Monitoring Plan), MM-BIO-2 (Worker Education Awareness Program), MM-BIO-3 (Delimiting Construction Area), and MM-BIO-4 (Biological Monitoring and Reporting) would reduce potential direct impacts to sensitive vegetation communities to less than significant. Indirect Impacts There is potential for indirect impacts to sensitive vegetation communities adjacent to and outside the proposed work areas. Indirect impacts may occur as the result of construction site runoff, accidental pollutant/chemical spills, discharge of materials from the use of concrete, oil/gas, water runoff, erosion, and fugitive dust. Impacts to sensitive vegetation communities are considered potentially significant. The implementation of MM-BIO-2, MM-BIO-3, MM-BIO-4, and MM-BIO-5 (Erosion and Sediment Control Plan) would reduce potential indirect impacts to sensitive vegetation communities to less than significant. City-Protected Trees The proposed work areas will be located outside the tree trunk base of mapped oak trees; however, the project will encroach within the City-established oak tree protected zone requirements (i.e., within 5 feet of the oak tree canopy or within 15 feet from the base of the tree trunk) for an estimated 8 oak trees overlapping with 0.04 acres (11%, 1,640 square feet) of the 0.33-acre mapped overhead canopy, suggesting these oaks trees may experience injury or mortality of the root systems. Additionally, inadvertent impacts to protected trees may occur if construction activities accidentally trim oak trees outside of the proposed work areas (i.e., permanent impact areas). These impacts are considered potentially significant;

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however, implementation of MM-BIO-2, MM-BIO-3, MM-BIO-4, and MM-BIO-6 (Protected Tree Removal, Replacement, and Protective Measures) would reduce potential direct impacts to individual oak trees to less than significant. Special Status Plant Species As previously discussed, one special-status plant species, Conejo dudleya, was observed within the BSA. Approximately 151 individuals were observed along the southeastern edge of the BSA, with the closest observations of impact areas about 25 feet uphill from the proposed debris basin. Direct Impacts The proposed work areas will be located outside the mapped Conejo dudleya population. However, inadvertent direct (temporary) impacts to Conejo dudleya may occur if construction activities accidentally trim, clear, trample, or grade individuals outside of the proposed work areas (i.e., permanent impact areas). Impacts to this special-status species are considered potentially significant. However, implementation of MM-BIO-2 (Worker Education Awareness Program), MM-BIO-3 (Delimiting Construction Area), and MM BIO-4 (Biological Monitoring and Reporting) would reduce potential direct impacts to this species to less than significant. Indirect Impacts There is potential for indirect impacts to Conejo dudleya adjacent to and outside of the proposed work areas to occur. Due to the species being located uphill from work areas, indirect impacts may occur as the result of fugitive dust. Impacts to this species is considered potentially significant. The implementation of MM-BIO-5 (Erosion and Sediment Control Plan), however, would reduce potential indirect impacts to this species to less than significant. Special-Status Wildlife Species As previously discussed, there is the potential for seven special-status wildlife species to occur within the BSA. These include three reptiles (California legless lizard, San Diegan tiger whiptail [Aspidoscelis tigris stejnegeri], and Accipiter cooperii], Southern California rufous-crowned sparrow [Aimophila ruficeps canescens], and coastal California gnatcatcher), and one mammal (San Diego desert woodrat). Reptiles Direct Impacts Project activities could result in direct permanent impacts to the California legless lizard, San Diegan tiger site. The project would result in permanent direct impacts to 0.09 acres of suitable on-site scrub habitat for these species. However, these impacts would be less than significant due to the abundant suitable habitat present in the vicinity of the project site.

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Individuals are cryptic and slow moving on the surface or are otherwise underground and, therefore, are highly vulnerable to injury and mortality during construction. Therefore, direct permanent impacts may result in mortality of these species, from heavy construction equipment, vehicle collisions, inadvertently stepping on individuals, or crushing occupied burrows. Impacts to special-status reptile individuals is considered potentially significant. However, implementation of MM-BIO-2 (Worker Education Awareness Program), MM-BIO-3 (Delimiting Construction Area), MM-BIO-4 (Biological Monitoring and Reporting), and MM-BIO-7 (Reptile Pre-Construction Survey) would reduce potential direct impacts to these species to less than significant. Indirect Impacts There is potential for indirect impacts to reptiles occurring adjacent to and outside of the proposed work areas. Indirect impacts may occur as the result of construction site runoff, accidental pollutant/chemical spills, discharge of materials from the use of concrete, oil/gas, water runoff, erosion, and fugitive dust. Impacts to these species is considered potentially significant. The implementation of MM-BIO-2, MM-BIO-3, MM-BIO-4, and MM-BIO-5 (Erosion and Sediment Control Plan) would reduce these impacts to less than significant. Avian Species Southern California rufous-crowned sparrow, and coastal California gnatcatcher have a potential to occur in the undeveloped open space areas throughout the BSA for perching, nesting, or foraging. The abundant prey (bird and rodent) populations in the adjacent open space would provide hunting the shrubs and vegetation in the BSA and greater open space would provide feeding, cover, and nesting opportunities for southern California rufous-crowned sparrow. Coastal California gnatcatcher are strongly associated with sage scrub habitats, which are present throughout the BSA. These habitats would provide feeding, cover, and nesting opportunities for this species, which is federally listed as threatened. Direct Impacts Due to the expansive open space surrounding the site, direct permanent impacts to 0.09 acres of scrub habitat (for foraging) and an estimated 8 individual oak trees (associated with 0.04 acres of overhead canopy) are not anticipated to adversely affect habitat for this species. The loss of nesting and foraging habitat would be less than significant because of the expansive habitat available surrounding the site. Individual adults are unlikely to be directly killed or injured during construction activities because they are highly mobile and would likely leave the area during construction. However, should any individuals nest within or adjacent to the project site, nesting could be disrupted (resulting in nest abandonment or reduced reproductive success) if construction occurs during the breeding season. In addition, should this species nest on site, nests, eggs, and young could be directly affected by oak tree vegetation clearing and grading. Any direct impacts to individuals, nests, eggs, or young, including nest abandonment, of this special-status species as a result of construction activities would be significant. Implementation of MM-BIO-8 (Pre-Construction Nesting Bird Survey) would reduce potential direct impacts to this species to less than significant.

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Indirect Impacts Short-term indirect impacts during construction that involve loud noise disruptions during the nesting season have the potential to impact nesting individuals on and adjacent to the existing facilities to the degree that the nests may be abandoned, resulting in a direct loss of an active nest. Impacts to nesting MM-BIO-8 would reduce potential indirect impacts to this species to less than significant. Southern California Rufous-Crowned Sparrow Direct Impacts Due to the expansive open space surrounding the site, direct permanent impacts to 0.09 acres of scrub habitat (for foraging) are not anticipated to adversely affect habitat for this species. The loss of nesting and foraging habitat would be less than significant because of the expansive habitat available surrounding the site. Individual adults are unlikely to be directly killed or injured during construction activities because they are highly mobile and would likely leave the area during construction. However, should any individuals nest within or adjacent to the project site, nesting could be disrupted (resulting in nest abandonment or reduced reproductive success) if construction occurs during the breeding season. In addition, should this species nest on site, nests, eggs, and young could be directly affected by scrub vegetation clearing and grading. Any direct impacts to individuals, nests, eggs, or young, including nest abandonment, of this special-status species as a result of construction activities would be significant. Implementation of MM-BIO-8 (Pre-Construction Nesting Bird Survey) would reduce potential direct impacts to this species to less than significant. Indirect Impacts Short-term indirect impacts during construction that involve loud noise disruptions during the nesting season have the potential to impact nesting individuals on and adjacent to the existing facilities to the degree that the nests may be abandoned, resulting in a direct loss of an active nest. Impacts to nesting Southern California rufous-crowned sparrow are considered potentially significant. Implementation of MM-BIO-8 would reduce potential indirect impacts to this species to less than significant. Coastal California Gnatcatcher Direct Impacts Due to the expansive open space surrounding the site, direct permanent impacts to 0.09 acres of sage scrub-associated habitats are not anticipated to adversely affect habitat for this species. The loss of nesting and foraging habitat would be less than significant because of the expansive habitat available surrounding the site. Individual adults are unlikely to be directly killed or injured during construction activities because they are highly mobile and would likely leave the area during construction. However, take in the form of harassment may occur if any individuals are present during construction activities. Additionally, take in the form of harm or mortality may occur if any individuals nest within or adjacent to the project site. Nesting could be disrupted (resulting in nest abandonment or reduced reproductive success) if construction occurs during

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the breeding season. In addition, should this species nest on site, nests, eggs, and young could be directly affected by sage scrub vegetation clearing and grading. Any direct impacts to individuals, nests, eggs, or young, including nest abandonment, of this special-status species as a result of construction activities would be significant. Implementation of MM-BIO-4 (Biological Monitoring and Reporting), MM-BIO-8 (Pre-Construction Nesting Bird Survey), and MM-BIO-9 (Coastal California Gnatcatcher Surveys and Avoidance) would reduce potential direct impacts to this species to less than significant. Indirect Impacts Short-term indirect impacts during construction that involve loud noise disruptions during the nesting season have the potential to impact nesting individuals on and adjacent to the existing facilities to the degree that the nests may be abandoned, resulting in a direct loss of an active nest. Impacts to nesting coastal California gnatcatcher are considered potentially significant. Implementation of MM-BIO-8 would reduce potential indirect impacts to this species to less than significant. Nesting Birds Removal of trees and vegetation associated with construction of the project have the potential to disturb nesting birds on and adjacent to the site, to the degree that the nests may be abandoned, resulting in a direct loss of an active bird nest. Bird nests with eggs or young of all migratory bird species are protected under the Migratory Bird Treaty Act (MBTA) and the CFGC. Active bird nests or nests with eggs or young of all native bird species are protected under the MBTA and the CFGC. Loss of active nests as a result of construction-related activities would conflict with these regulations and thus would be considered significant impacts. Direct Impacts Removal of vegetation associated with construction activities has the potential to disturb nesting birds on and adjacent to the site, to the degree that the nests may be abandoned, resulting in a direct loss of an active bird nest. Individual adults are unlikely to be directly killed or injured during construction activities because they are highly mobile and would likely leave the area during construction. However, should any individuals nest within or adjacent to the project site, nesting could be disrupted (resulting in nest abandonment or reduced reproductive success) if construction occurs during the breeding season. In addition, should these species nest on site, nests, eggs, and young could be directly affected by scrub vegetation clearing and grading. Any direct impacts to individuals, nests, eggs, or young, including nest abandonment, of bird species protected under the MBTA and/or CFGC as a result of construction activities would be significant. Implementation of MM-BIO-8 (Pre-Construction Nesting Bird Survey) would reduce potential direct impacts to these species to less than significant. Indirect Impacts Short-term indirect impacts during construction that involve loud noise disruptions during the nesting season have the potential to impact nesting individuals on and adjacent to the existing facilities to the degree that the nests may be abandoned, resulting in a direct loss of an active nest. Impacts to nesting birds protected under the MBTA and/or CFGC are considered potentially significant. Implementation of MM-BIO-8 would reduce potential indirect impacts to these species to less than significant.

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MM-BIO-1 Habitat Mitigation and Monitoring Plan. Prior to issuance of a project grading permit, the City of Thousand Oaks (City) shall contract with a qualified botanist/biologist to develop a Habitat Mitigation and Monitoring Reporting Plan (Plan) to provide compensatory mitigation for permanent impacts to 0.03 acres of lemonade berry scrub (Rhus integrifolia) and 0.06 acres of lemonade berry scrubCalifornia sagebrush scrub (Artemisia californica) (California Department of Fish and Wildlife sensitive vegetation communities). The Plan shall outline efforts to restore or enhance these sensitive vegetation communities and, therefore, preserve or provide wildlife habitat within similar upland habitats adjacent to the impacted biological resources. The Plan may focus on the following: In-kind restoration of lemonade berry scrub and/or lemonade berry scrubCalifornia sagebrush scrub through incorporation of these communities Restoration of areas occupied by non-native habitats or native habitats with large components of non-native vegetation, within similar habitats adjacent to the impacted biological resources Under the Plan, a total of 0.09 acres of permanently impacted upland vegetation communities shall be mitigated in-kind at a 2:1 ratio for a total of 0.18 acres of compensatory mitigation. A qualified biologist/botanist shall develop the Plan, which shall provide specific measures to restore or enhance habitat to replace the loss of permanently impacted communities. This Plan shall be focused on adaptive management principles and shall identify detailed enhancement areas and strategies based on the parameters outlined below, with long-term timing and monitoring requirements. The Plan shall also address the approximately 0.01 acres (315 square feet; 105 linear feet) of non-wetland waters of the State, including up to mapped top of bank; and 0.01 acres (332 square feet) of riparian (blue elderberry scrub [Sambucus mexicana]) permanently impacted by the project. The Plan shall provide for compensatory mitigation at a minimum 3:1 ratio for in-kind or similar mitigation, or other compensatory mitigation approved by the regulatory agencies. Specifically, the Plan will prescribe actions and measures to compensate for project impacts. The Plan will present project impacts, the site selection process, and a rationale for success; specifications regarding final mitigation acreages, site preparation, restoration implementation, plant and seed collection source and sizing; project implementation guidelines; interim and final ecological performance standards; requirements for long-term maintenance, monitoring, and reporting; and site protection and long-term management. The Plan will include the following elements: Mitigation ratios for permanent and temporary impacts (if any) to regulated aquatic resources including, but not limited to, riparian habitat, waters of the United States, waters of the State, and CDFW streambed and riparian habitat established in consultation with the U.S. Army Corps of Engineers, Regional Water Quality Control Board, and California Department of Fish and Wildlife Provide site selection and justification

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Detailed descriptions of mitigation components proposed to achieve the compensatory mitigation requirements of the resource agency permits Plant palette(s) for each target vegetation community proposed to be restored to the mitigation site Defined attainable and measurable mitigation goals and objectives to be achieved through implementation of the Plan A restoration work plan that details the mitigation approach, a restoration schedule, plant materials (containers, seed), and implementation strategies A detailed maintenance plan to include removal of invasives and non-native species Defined ecological performance standards for determining the success of the mitigation program A monitoring plan that includes method and analyses of results, goals for success or failure, and an adaptive management plan and suggestions for failed restoration efforts Restoration activities using native riparian and wetland species from locally collected stock, if applicable A description of protection measures and an estimate of long-term management funding An estimate of implementation costs Annual reports and the final report shall be submitted to the City and applicable regulatory agencies MM-BIO-2 Worker Education Awareness Program. Prior to the initiation of any site disturbance and/or construction activities, all personnel associated with the project shall attend a worker education awareness program (program) conducted by a qualified biologist. In general, it is recommended that the program discuss any potentially occurring sensitive biological resources or species and habitat preference(s), occupied habitat in the area, life histories, law and regulations, potential construction impacts and protection measures, and project limits. Protections and regulations for biological resources, special-status species, protection of aquatic resources and open space, and nesting birds shall also be included in the program. It is recommended that a species and habitat fact sheet also be developed prior to the training program and distributed at the training program to all contractors, employers, and other personnel involved with the construction of the project. After the kickoff meeting, the project proponent shall notify the qualified biologist in advance if additional contractors are employed during construction. A sign-in sheet will be circulated for signatures to all personal that attend the workers educational training to confirm that program materials were received and that they understand information presented. MM-BIO-3 Delimiting Construction Area. Prior to initiation of ground disturbance, grading, or equipment mobilization, the following measures shall be implemented to protect natural resources adjacent to construction areas: Temporary fencing or equivalent form of demarcation shall be installed along the perimeter of defined construction areas to protect natural resources.

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All construction-related activities shall be confined to the designated construction areas within the fenced/demarcated areas. Fencing/demarcation shall be maintained during the duration of the project, including fixing or replacing downed fence. Fencing/demarcation shall remain in place for the duration of the project until all project activities are complete. A qualified biological monitor shall monitor the condition of the fence to ensure avoidance of impacts to surrounding resources. When sizable construction equipment is working near oak trees, it is highly encouraged that flaggers are utilized to assist in equipment positioning to avoid impacts to oak tree canopies (not proposed for removal) during construction activities MM-BIO-4 Biological Monitoring and Reporting. A qualified biologist shall be present during initial ground-disturbing activities (i.e., grading, trenching, vegetation trimming or clearing) occurring within undeveloped areas (i.e., not the existing developed Hill Canyon Treatment Plant areas). Each day prior to equipment mobilization, the biologist shall perform a clearance survey in which the work area and equipment within undeveloped areas is inspected for wildlife. The biologist shall provide guidance and ensure that biological resource protection measures are in place to the maximum extent feasible. The monitor shall be experienced in construction monitoring and be able to identify potentially occurring sensitive biological resources in the area, including the coastal California gnatcatcher (Polioptila californica californica). The monitor shall survey the construction project footprint and surrounding areas for compliance with all environmental specifications. The biologist shall have authority to halt work if listed species are observed and immediately notify California Department of Fish and Wildlife and/or U.S. Fish and Wildlife Service (as applicable), and additional appropriate avoidance and minimization measures shall be implemented if determined necessary for the protection of special-status species. Sensitive wildlife species may only be moved from the work area by qualified biologists holding the required permits; however, endangered or threatened species will not be moved, harassed, or harmed and will be allowed to move out of harm on their own (unless other arrangements are approved by the regulatory agencies). Daily biological construction monitoring reports shall be prepared by the biologist and submitted to the appropriate permitting and responsible agencies on a weekly basis (weekly reporting). In addition, at the completion of monitoring activities, the biologist will submit a final monitoring report to the appropriate permitting and responsible agencies to document compliance with environmental requirements. MM-BIO-5 Erosion and Sediment Control Plan. Due to the project impact of less than 1 acre, the applicant shall prepare an Erosion and Sediment Control Plan (ESCP) to minimize the potential for discharge of pollutants during construction activities. The ESCP shall be designed to meet the local requirements and Ventura County permitting process (e.g., grading or building permit). The ESCP shall include both structural and non-structural best management practices (BMPs), including straw wattles around storm drains, silt fencing

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and or other physical controls to divert flows from exposed soil, spill prevention methods, and clean housekeeping methods for storing and refueling machinery. As part of the ESCP, the contractor shall include specifications, installation requirements, and locations of appropriate BMPs to control sediment, coarse particles, concrete, and other materials exposed during construction and drilling, to protect aquatic and riparian habitats adjacent to construction site. Erosion control measures shall be implemented to prevent runoff of these materials into potential jurisdictional aquatic features. Silt fencing, straw bales, and/or sandbags shall be used in conjunction with other methods to prevent turbid waters from entering the potential jurisdictional aquatic features. BMPs shall be implemented that minimize impacts from the generation of fugitive dust, fire hazards, and chemical pollutants. During construction activities, washing of concrete or equipment shall occur only in areas where polluted water and materials can be contained for subsequent removal from the site. Washing shall not be allowed in locations where the tainted water could enter potential jurisdictional aquatic features. MM-BIO-6 Protected Tree Removal, Replacement, and Protective Measures. The City of Thousand Oaks requires a permit for removal, pruning, or encroachment into the protected zone of any oak tree or landmark tree, which are defined as: Oak Tree: Any oak tree of the genus Quercus including, but not limited to, valley oak (Quercus lobata), California live oak (Quercus agrifolia) and scrub oak (Quercus berberidifolia), regardless of size (Thousand Oaks Municipal Code, Title 5, Chapter 14: Oak Tree Preservation and Protection). Landmark Tree: Specimens of the following species that have reached the designated maturity: California sycamore (Platanus racemosa), which exceed 12 inches in diameter when measured at a point 4.5 feet above the natural grade at the base of the tree; California bay laurel (Umbellularia californica), which exceed 8 inches in diameter when measured at a point 4.5 feet above the natural grade at the base of the tree; California black walnut (Juglans californica), which exceed 8 inches in diameter when measured at a point 4.5 feet above the natural grade at the base of the tree; and toyon (Heteromeles arbutifolia), which exceed 8 inches in diameter when measured at a point 4.5 feet above the natural grade at the base of the tree. Trees with multiple trunks shall be deemed to have reached maturity if the sum of the diameters of the multiple trunks exceeds the required diameter plus 2 inches of a single trunked tree. Landmark trees shall also include all designated historic trees. (Thousand Oaks Municipal Code, Title 5, Chapter 24: Landmark Tree Preservation and Protection). Prior to construction activities, an International Society of Arboriculture-certified arborist shall review the proposed construction plans, visit the project site, and assess the condition, health, and structure of oak and landmark trees with a potential to be directly (removed or encroached upon) impacted by project activities, including trees proposed to be trimmed or removed. Encroachment shall include project-related disturbances that will occur within the protected zone (a specifically defined area totally encompassing a

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landmark or historic tree within which work activities are strictly controlled). When depicted on a map, the outermost edge of the protected zone will appear as an irregularly shaped circle that follows the contour of the dripline of the tree. Using the dripline as a point of reference, the protected zone shall commence at a point 5 feet outside of the dripline and extend inward to the trunk of the tree. In no case shall the protected zone be less than 15 feet from the trunk of a landmark tree (both code sections). The certified arborist shall provide a letter/report (Oak Tree Report) containing specific information on the location, condition, potential impacts of development, recommended actions, and mitigation measures. At minimum, mitigation measures shall include requirements for arborist monitoring during work within the tree protected zone (i.e., within 5 feet of the oak tree canopy or within 15 feet from the base of the tree trunk) of any oak or landmark trees. The City of Thousand Oaks Oak Tree Preservation and Protection Guidelines mitigation requirements for tree removals associated with development projects are summarized as follows: one 15-gallon oak tree must be planted or donated for each dead or hazardous oak tree removed; two 24-inch box trees and one 36-inch or 60-inch box tree must be planted for each healthy oak tree removed for commercial, industrial, and new residential development projects; and, in the case of removal of oak trees larger than 48 inches in diameter, the applicant is required to obtain the largest nursery-grown oak tree available or plant two 60-inch box trees. MM-BIO-7 Reptile Pre-Construction Survey. A pre-construction survey for California legless lizard (Anniella sp.), San Diegan tiger whiptail (Aspidoscelis tigris stejnegeri)horned lizard (Phrynosoma blainvillii) shall be conducted 30 days prior to the initiation of project activities. If these species are observed, a salvage and relocation plan shall be implemented to allow a qualified biologist to capture and relocate the species away from ground disturbance and into protected open space. These survey and reporting measures are often a condition of the California Department of Fish and WildlifeStreambed Alteration Agreement. MM-BIO-8 Pre-Construction Nesting Bird Survey. A pre-construction survey for nesting birds shall be conducted by a City of Thousand Oaks-approved biologist to determine if active (nests containing eggs, nestlings, or associated with dependent fledglings) of special-status birds, or common bird species protected by the Migratory Bird Treaty Act and/or the California Fish and Game Code, are present in the construction zone or within 300 feet of the construction zone. The survey shall be conducted within 1 week prior to construction or site preparation activities that will occur during the nesting/breeding season of native bird species potentially nesting on the site (typically February 1 through August 31). The pre-construction nesting bird survey shall be repeated if there is a delay in the start of construction activity or if a lapse in construction activity of 2 weeks or greater has occurred. Within 1 week before the start of construction activities, a City of Thousand Oaks-approved biologist shall conduct the nesting bird survey. A pre-construction nesting bird report shall be completed and submitted to the City of Thousand Oaks within 48 hours of the survey.

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If active nests are found, a no-construction buffer shall be established at a minimum of 50 feet for non-raptor bird species and 200 feet for raptor species (this distance may be greater depending on the bird species and construction activity, as determined by the City of Thousand Oaks-approved biologist) around the nest site where it overlaps with work areas. Tree and vegetation clearing and construction within the no-construction buffer shall be postponed or halted, at the discretion of the City of Thousand Oaks-approved biologist, until the nest is vacated, juveniles have fledged, and there is no evidence of a second attempt at nesting. In addition, all active nests shall be mapped with a GPS unit and nest locations with 100-foot buffers overlain on aerial photographs to provide regular updated maps to inform the project manager/engineer and construction crew of areas to avoid. The City of Thousand Oaks-approved biologist shall also serve as a construction monitor during the breeding season to ensure that there are no inadvertent impacts to nesting birds. Bird nest surveys shall be conducted every 14 days following identification of an active bird nest until all birds have fled the nest and the nest is deemed inactive by the City of Thousand Oaks-approved biologist. A bird nest monitoring report shall be completed and submitted to the City of Thousand Oaks. MM-BIO-9 Coastal California Gnatcatcher Surveys and Avoidance. Prior to construction, protocol-level surveys for the coastal California gnatcatcher (Polioptila californica californica) shall be performed within 500 feet of proposed temporary and permanent impact areas. If any individuals are detected during the surveys, the results shall be communicated to the U.S. Fish and Wildlife Service for approvals prior to construction. In the absence of protocol surveys, the U.S. Fish and Wildlife Service shall be consulted for further guidance. b) Would the project have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? Less-than-Significant Impact with Mitigation Incorporated. As previously discussed, four sensitive vegetation communities (California brittle bushCalifornia sagebrush scrub, chamiseblack sagesugarbush scrub, lemonade berry, and lemonade berryCalifornia sagebrush scrub) were identified within the BSA. Of these four sensitive communities, permanent impacts will occur to 0.03 acres of lemonade berry scrub and 0.06 acres of lemonade berry scrubCalifornia sage brush scrub. Permanent impacts to lemonade berry scrub would include the removal of <0.01 acres (332 square feet) of blue elderberry, which is present along the existing ephemeral channel and provides limited riparian habitat. As previously mentioned, the ephemeral waterway is located within the proposed debris basin. Direct Impacts As shown in Figure 9, Impacts to Biological Resources, and Table 3-9, the project will permanently impact approximately 0.09 acres of sensitive vegetation communities, including 0.01 acres of riparian habitat. In addition, inadvertent direct (temporary) impacts to sensitive communities may occur if construction activities accidentally trim, clear, trample, or grade sensitive vegetation communities outside of the proposed work

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areas (i.e., permanent impact areas). Impacts to sensitive vegetation communities are considered potentially significant. However, implementation of MM-BIO-1 (Habitat Mitigation and Monitoring Plan), MM-BIO-2 (Worker Education Awareness Program), MM-BIO-3 (Delimiting Construction Area), and MM-BIO-4 (Biological Monitoring and Reporting) would reduce potential direct impacts to riparian and other sensitive vegetation communities to less than significant. Indirect Impacts There is potential for indirect impacts to sensitive vegetation communities adjacent to and outside of the proposed work areas. Indirect impacts may occur as the result of construction site runoff, accidental pollutant/chemical spills, discharge of materials from the use of concrete, oil/gas, water runoff, erosion, and fugitive dust. Impacts to sensitive vegetation communities are considered potentially significant. Therefore, MM-BIO-2, MM-BIO-3, MM-BIO-4, and MM-BIO-5 (Erosion and Sediment Control Plan) are recommended to avoid potential indirect impacts to sensitive vegetation communities. The implementation of these mitigation measures would reduce potential indirect impacts to riparian habitat or other sensitive natural communities to less than significant. Table 3-9. Proposed Impacts to Vegetation and Land Cover Types within the BSA General Habitat Vegetation Community Global, State Ranka CDFW Sensitiveb Permanent Impacts acres (square feet) Native Scrub California brittle bushCalifornia sagebrush scrub Association G3 Y None ChamiseBlack sageSugarbush scrub Association G3, S3 Y None Lemonade berry scrub Alliance G3, S3 Y 0.03 Lemonade berry scrubCalifornia sage scrub Association Y 0.06 Other Land Cover Types Developed N/A N 0.19 Disturbed N/A N 0.06 Total 0.35 Notes: BSA = Biological Survey Area; CDFW = California Department of Fish and Wildlife; Y = yes; N/A = not applicable; N = no. G3 and S3 are ranks considered vulnerable. a For alliances with State Ranks of S1 to S3, all associations within them are considered highly imperiled. A question mark (?) denotes an inexact numeric rank due to insufficient samples over the full expected range of the type, but existing information points to this rank (CDFW 2022a). b Sensitive based on CDFW (2022a). However, communities determined to not be sensitive may still be sensitive under local policies or provide suitable habitat for special-status plant and wildlife species. c) Would the project have a substantial adverse effect on State or federally protected wetlands (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? Less-than-Significant Impact with Mitigation Incorporated. As previously discussed, non-wetland waters are present within the BSA and project impact areas. This includes approximately 0.03 acres of non-wetland waters of the State and less than 0.01 acres (332 square feet) of riparian habitat that are regulated by the RWQCB and/or CDFW. None of the features on or within the project site are anticipated to be under the jurisdiction of the USACE.

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Direct Impacts The project will permanently impact approximately 0.01 acres (315 square feet; 105 linear feet) of non-wetland waters of the State, including up to mapped top of bank; and less than 0.01 acres (332 square feet) of riparian habitat would be directly (permanently) impacted as a result of the construction of the debris basin. This area is regulated by the RWQCB and/or CDFW, and final determination of the extent of jurisdictional impact is determined by these responsible agencies. In addition, inadvertent direct (temporary) impacts to jurisdictional waters may occur if construction activities accidentally grade or remove soils outside of the proposed work areas. Direct impacts to jurisdictional aquatic resources are considered potentially significant. However, implementation of MM-BIO-1 (Habitat Mitigation and Monitoring Plan), MM-BIO-2 (Worker Education Awareness Program), MM-BIO-3 (Delimiting Construction Area), and MM-BIO-4 (Biological Monitoring and Reporting) would reduce potential direct impacts to jurisdictional aquatic resources to less than significant. Indirect Impacts There is potential for indirect impacts to jurisdictional aquatic resources adjacent to and outside of the proposed work areas. Indirect impacts may occur as the result of construction site runoff, accidental pollutant/chemical spills, discharge of materials from the use of concrete, oil/gas, water runoff, and fugitive dust. Impacts to jurisdictional aquatic resources are considered potentially significant. Therefore, MM-BIO-2, MM-BIO-3, MM-BIO-4, and MM-BIO-5 (Erosion and Sediment Control Plan) are recommended to avoid potential indirect impacts to jurisdictional aquatic resources. The implementation of these mitigation measures would reduce indirect impacts to State or federally protected wetlands to less than significant. d) Would the project interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? Less-than-Significant Impact. As previously discussed, the Treatment Plant and project site are located between two large open space systems that provide regional habitat connectivity for a variety of wildlife. However, the existing Treatment Plant is fully enclosed with a chain-link fence. Therefore, the Treatment Plant provides no opportunities for wildlife movement and project activities within the Treatment Plant are not expected to affect wildlife corridors. Although the proposed debris basin is located within undeveloped open space, the location and proposed permanent impact areas (0.09 acres of scrub within the open space area) are adjacent to the existing fenced facility (extending out to approximately 47 feet southeast of the fence line). In addition, no new lighting is proposed within or adjacent to open space for this project. With abundant surrounding open spaces and opportunities for movement, the construction of the debris basin at this location is not anticipated to impede, interfere, or significantly affect wildlife movement, corridors, or linkages. Due to the relatively small size of the proposed project, direct impacts to wildlife corridors and habitat connectivity are not anticipated to occur and indirect impacts to wildlife corridors and habitat connectivity are anticipated to be minor. Therefore, impacts to wildlife corridors and habitat connectivity would be less than significant.

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e) Would the project conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? Less-than-Significant Impact with Mitigation Incorporated. Approximately 19 oak trees larger than 2 inches in diameter were identified within the BSA. The City protects oak trees and landmark trees through City ordinances. Municipal Code Section 9-4.42 provides the Oak Tree Preservation and Protection Ordinance and Municipal Code Section 9-4.42 provides the Landmark Tree Preservation and Protection Ordinance. In addition, all work involving impacts to oak trees within the City is required to abide by the provisions of the Oak Tree Ordinance, Title 5, Chapter 14 of the Thousand Oaks Municipal Code, and the Oak Tree Preservation and Protection Guidelines Res. No. 2010-014. The City requires a permit for removal, pruning, or encroachment into the protected zone of any oak tree or landmark tree, which are defined below. Direct Impacts As shown in Figure 9, the proposed work areas will be located outside the tree trunk base of mapped oak trees. However, the project will encroach within the City-established oak tree protected zone requirements (i.e., within 5 feet of the oak tree canopy or within 15 feet from the base of the tree trunk) for an estimated 8 trees and overlap with 0.04 acres (11%, 1,640 square feet) of the 0.33-acre mapped overhead canopy, suggesting these oak trees may experience injury or mortality of the root systems. In addition, inadvertent direct (temporary) impacts to sensitive communities may occur if construction activities accidentally trim oak trees outside of the proposed work areas (i.e., permanent impact areas). Impacts to oak trees are considered potentially significant. However, implementation of MM-BIO-2 (Worker Education Awareness Program), MM-BIO-3 (Delimiting Construction Area), MM-BIO-4 (Biological Monitoring and Reporting), and MM-BIO-6 (Protected Tree Removal, Replacement, and Protective Measures) would reduce potential direct impacts to individual oak trees to less than significant. Indirect Impacts There is potential for indirect impacts to oak trees adjacent to and outside of the proposed work areas. Indirect impacts may occur as the result of construction site runoff, accidental pollutant/chemical spills or discharge of materials from the use of concrete, oil/gas, water runoff, or on-site fueling stations. Impacts to oak trees are considered potentially significant. Therefore, MM-BIO-2, MM-BIO-3, MM-BIO-4, and MM-BIO-5 are recommended to avoid potential indirect impacts to oak trees. The implementation of these mitigation measures would reduce potential indirect impacts to oak trees to less than significant. f)Would the project conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or State habitat conservation plan? No Impact. According to the CDFW, there is no Natural Communities Conservation Plan on or within the vicinity of the project site. As such, there is no adopted, approved, or proposed Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or State habitat conservation plan that covers habitats located within the p. Therefore, no impact would occur.

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3.5 Cultural Resources Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact V. CULTURAL RESOURCES Would the project: a) Cause a substantial adverse change in the significance of a historical resource pursuant to §15064.5? b) Cause a substantial adverse change in the significance of an archaeological resource pursuant to §15064.5? c) Disturb any human remains, including those interred outside of formal cemeteries? A Phase 1 cultural resources investigation was conducted in support of the IS for the project (Appendix C1 to this IS/MND) and a built environment inventory and evaluation report (Appendix C2) was prepared. The cultural resources investigation included a cultural resources site records and literature search at the South Central Coastal Information Center (SCCIC), located on the campus of California State University, Fullerton, and an intensive surface survey covering the project site to document existing conditions and to assess the potential impacts of the project on cultural resources. In addition to the California Historical Resources Information System (CHRIS) records search at the SCCIC, the Phase 1 cultural resources investigation included a review of the California Native American Heritage Commission (NAHC) Sacred Lands File (SLF) and background research. California Historical Resources Information System Records Search On March 24, 2022, staff at the SCCIC provided the results of a CHRIS records search for the project site and a 0.5-mile radius. Due to COVID-19, the SCCIC notified researchers that they were only able to provide data for the County that have already been digitized. As such, not all available data known to CHRIS may be provided in the records search. The CHRIS records search results provided by the SCCIC included their digitized collections of mapped prehistoric and historic archaeological resources and historic built-environment resources, Department of Parks and Recreation site records, technical reports, archival resources, and ethnographic references. Additional consulted sources included historical maps of the project site, the National Register of Historic Places, the California Register of Historical Resources (CRHR), the California Historic Property Data File, and the lists of California State Historical Landmarks, California Points of Historical Interest, and the Archaeological Determinations of Eligibility. The SCCIC records were reviewed to determine whether the implementation of the project would have the potential to impact known cultural resources. The confidential records search results are also provided in Confidential Attachment C to the cultural resources report (Appendix C1). Previously Conducted Cultural Resource Studies Results of the cultural resources records search indicate that 19 previous cultural resource studies have been conducted within 0.5 miles of the proposed project site between 1975 and 2006. Of these studies, five overlap the proposed project site: VN-84, -101, -1527, -1573, and -1593. Table 3-10 lists all 19 previous cultural resources studies, followed by a brief summary of the available reports for sites overlapping the proposed project site.

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Table 3-10. Previous Technical Studies Within a 0.5-Mile Radius of the Project Site SCCIC Report No. (VN-) Authors Date Title Addresses Project Site 00033 Maxwell, T.J. 1975 Environmental Impact Report Sch. No. 75051421 Unit "y" Sewer Replacement I.D. No. 76-1258, F.Y. 1975-76 No 00059 Rosen, M.D. 1977 Evaluation of the Archaeological Resources and Potential Impact of Proposed Development of 632 Acres in Thousand Oaks, California No 00084 Clewlow, W.C. Jr. 1977 An Archaeological Resource Survey and Preliminary Impact Assessment of the MGM Ranch Property Thousand Oaks, California Yes 00101 Rosen, M.D. 1976 Conejo Canyons Study Yes 00103 Clewlow, W.C. Jr. 1978 Preliminary Archaeological Investigations on MGM Ranch: 4-VEN-170, 4-VEN-171, 4-VEN-272, 4-VEN-437, 4-VEN-449 No 00231 Lopez, R. 1980 A Re-evaluation of the Archaeological Resources Contained Within and Directly or Indirectly Impacted by the 633 Acres Proposed for Tract 3465 Thousand Oaks, Ventura County, California No 00403 Dillon, B.D. 1977 CA-VEN-171: Boundary Test Report No 00914 Whitley, D.S. 1985 Archaeological Survey of Portions of the Northrop Corporation Property, Newbury Park, Ventura County, California No 01087 Clewlow, W.C. Jr. 1991 Letter Report on Preliminary Archaeological Mitigative Procedures at Site CA-VEN-170 No 01088 Clewlow, T.A., and C.W. Clewlow 1991 Archaeological Investigations at CA-VEN-445 City of Thousand Oaks, California No 01130 Drover, C.E. 1988 Environmental Impact Evaluation: An Archaeological Assessment of Vesting Tentative Tract Map 4366--Rancho Conejo City of Thousand Oaks, California No 01419 Maxwell, T.J. 1976 Unit "Y" Sewer Replacement Sch. No. 75051421 City of Thousand Oaks No 01527 Allen, P.A. 1978 An Historic Study of the Property Known As the M.G.M Ranch a Planned Community by Shapell Industries Inc. Yes

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Table 3-10. Previous Technical Studies Within a 0.5-Mile Radius of the Project Site SCCIC Report No. (VN-) Authors Date Title Addresses Project Site 01573 Maki, M.K. 1997 Phase 1 Archaeological Survey and Impact Assessment of Approximately 4 Linear Miles for the Unit W & F Interceptor Replacement Project Arroyo Conejo Thousand Oaks, Ventura County, California Yes 01593 Bonner, W. 1997 Cultural Resources Assessment of the Hill Canyon Regional Recreational Facility, Thousand Oaks, Ca Yes 01864 Maki, M.K. 2000 Cultural Resource Monitoring Results for the Dewatering and Generator Building at the Hill Canyon Wastewater Treatment Plant No 01866 Romani, J.F. 2000 Results of Archaeological Phase II/ phase III Excavations Damage Assessment and Repatriation of Disinterred Native American Remains in Accordance With the Requirements of NAGPRA at CA-VEN-1602 Hill Canyon Waste Water Treatment Plant No 02505 Maki, M.K. 2006 Phase 1 Cultural Resources Investigation of Approximately 0.8 Ac for the Mesa Feeder Crossing Relocation Project Arroyo Conejo, Thousand Oaks, Ventura Co. No 02637 Whitley, D.S. 2002 Extended Phase I Archaeological Survey for the Hill Canyon Wetlands Mitigation Study Area, Thousand Oaks, Ventura County, California No Note: SCCIC = South Central Coastal Information Center. Report No. VN-84. Archaeological Resource Survey and Preliminary Impact Assessment of the MGM Ranch Property Thousand Oaks, California (Clewlow 1977) documents the results of an archaeological survey and impact assessment consisting of archival record search, literature review, and pedestrian survey. The area of study overlaps the southwest area of the current proposed project site, as well as the southernmost extent of the larger, primary section. The report relocated and re-evaluated five previously recorded sites and identified 21 new archaeological sites. None of the sites overlaps the current proposed project site. A variety of mitigations measures was recommended, including testing, capping, and the creation of open space to preserve the cultural resources noted. It was further recommended that a general research design be created for the area to carry out any mitigation efforts within the framework of a comprehensive research design. Report No. VN-101. Conejo Canyons Study (Rosen 1977) documents the results of a study to address existing environmental resources of the Conejo Canyons and to suggest planning policy, criteria, and standards for the future use of and conservation of those resources. The area of study overlaps all areas of the current proposed

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project site. The goal of the survey was to record existing resources; the archaeology analysis component included archival research and recounting of known resources. The records search indicated there were 2632 known sites recorded, of which 21 were either disturbed or destroyed. The large number of known sites led the study to indicate the area has a high degree of archaeological sensitivity. Report No. VN-1527. An Historic Study of the Property Known As the M.G.M Ranch a Planned Community by Shapell Industries Inc. (Allen 1978) documents the results of a historic study of the M.G.M. Ranch property as part of a greater study for a planned development. The area of study overlaps the southwest area of the current proposed project site, as well as the southernmost extent of the larger, primary section. The primary focus of the report, formally recorded by Patricia Allen, is the historic record of the M.G.M. Ranch property as documented through grants and purchases. Included in the appendix are records of three archaeological resource surveys, although the reports are not attached. The reports indicated that there were 24 known archaeological sites within the boundaries of the specific plan and made mitigation recommendations including avoidance, excavation, and cultural monitoring. Report No. VN-1573. Phase 1 Archaeological Survey and Impact Assessment of Approximately 4 Linear Miles for the Unit W & F Interceptor Replacement Project Arroyo Conejo Thousand Oaks, Ventura County, California (Maki 1997) documents the results of a Phase I cultural resources investigation in the Arroyo Conejo and selected tributary canyons, consisting of archival record research, literature review, consultation with local Native Americans, and a pedestrian survey. The area of study overlaps the southwestern area of the current proposed project site. The study referenced multiple archaeological sites located on the bluffs and hills above the Arroyo Conejo, but none ical monitoring and a temporary work halt order should archaeological resources or human remains be unearthed. Report No. VN-1593. Cultural Resources Assessment of the Hill Canyon Regional Recreational Facility, Thousand Oaks, Ca (Bonner 1997) documents the results of a Phase I cultural resources assessment of the Acacia Hill Canyon Regional Recreational Facility, consisting of archival records research, literature review, and a pedestrian survey of the subject property. The area of study overlaps the southwest area of current proposed project site and is adjacent to the larger, primary section. Mitigation recommendations included archaeological monitoring during any construction activity, including vegetation clearance near known prehistoric sites. The author further recommended subsurface testing should any buried midden component be encountered. Previously Recorded Cultural Resources The SCCIC records indicate that eight cultural resources have been previously recorded within 0.5 miles of the project site, none of which overlap or are adjacent to the project site; however, at least one of the prehistoric archaeological sites is located within 50 meters (165 feet) of the project site. Of these resources, seven are prehistoric-era archaeological sites and one is a historic-era archaeological site. Table 3-11 summarizes all previously recorded cultural resources identified within the search area.

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Table 3-11. Previously Recorded Cultural Resources within a 0.5-Mile Radius of the Proposed Project Site SCCIC ID Trinomial Description Recording Events NRHP Status Located within Project Site (Yes/No) P-56-000170 CA-VEN-000170 Prehistoric Site: Lithic scatter 1967 (C. King) 7R: Identified in Reconnaissance Level Survey: Not evaluated No P-56-000171 CA-VEN-000171 Prehistoric Site: Lithic scatter; ground stone 1967 (C. King); 1981 (B.D. Dillon); 1989 (R. Angula and K. Becker) 7R: Identified in Reconnaissance Level Survey: Not evaluated No P-56-000172 CA-VEN-000172 Prehistoric Site: Lithic scatter 1967 (C. King); 1989 (R. Angula and K. Becker) 7R: Identified in Reconnaissance Level Survey: Not evaluated No P-56-000173 CA-VEN-000173 Prehistoric Site: Lithic scatter; ground stone 1967 (C. King) 7R: Identified in Reconnaissance Level Survey: Not evaluated No P-56-000445 CA-VEN-000445 Prehistoric Site: Lithic scatter 1977 (Whitley and Ivie) 7R: Identified in Reconnaissance Level Survey: Not evaluated No P-56-000446 CA-VEN-000446 Prehistoric Site: Small lithic scatter 1977 (Whitley and Ivie) 7R: Identified in Reconnaissance Level Survey: Not evaluated No P-56-001602 N/A Prehistoric Site: Marine shell scatter, fire affected rock and projectile point 2000 (M. Maki) 7R: Identified in Reconnaissance Level Survey: Not evaluated No P-56-100078 N/A Historic Site: Steel plate storage tank 1997 (W. Bonner); 2001 (D. Whitley) 7R: Identified in Reconnaissance Level Survey: Not evaluated No Notes: SCCIC = South Central Coastal Information Center; NRHP = National Register of Historic Places; N/A = not applicable. Pedestrian Survey Methods: The intensive-level survey methods consisted of a pedestrian survey conducted in parallel transects, spaced no more than 5 meters apart (approximately 15 feet), where feasible. The ground surface was inspected for prehistoric artifacts (e.g., flaked stone tools, tool-making debris, ground stone tools, ceramics, fire-affected rock), soil discoloration that might indicate the presence of a cultural midden, soil depressions, features indicative of structures and/or buildings (e.g., standing exterior walls, post holes, foundations), and historical artifacts (e.g., metal, glass, ceramics, building materials). Ground disturbances such as rodent burrows, cut banks, trails, and drainages were also visually inspected for exposed subsurface materials. No artifacts were collected during the survey.

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All fieldwork was documented using field notes, an Apple Generation 7 iPad equipped with Esri Collector and Avenza PDF Maps software with close-scale georeferenced field maps of the proposed project site, and aerial photographs. Location--mega-pixel resolution camera. Cultural resources identified during this inventory within the proposed project site were to be recorded on Department of Parks and Recreation forms, using the Instructions for Recording Historical Resources (Office of Historic Preservation 1995). All field notes, photographs, and records related to the current study are on file with the City. All field practices met resources inventory. Results: An intensive-level archaeological pedestrian survey of the 0.5-acre proposed project site was completed on March 21, 2022. Careful attention was given to barren ground, including at the base of trees and bushes, within paths/trails, and any subsurface soils exposed by burrowing animals. Ground surface visibility within the proposed project site was variable and as such, in areas of dense ground coverage, surface scrapes were occasionally implemented, when necessary, to enhance detection of archaeological materials that may have been obscured on the surface. Survey results for the project site are detailed below. The proposed project site is currently partially developed and in use as a wastewater Treatment Plant. The majority of the proposed project area is undeveloped open space that borders the existing Treatment Plant. Two separate areas were surveyed on March 21, 2022. The small area near Edison Gate was surveyed first. The exposed ground area provided good to excellent visibility, but only comprised 10% of the whole area; the remaining 90% was paved, providing none to poor ground surface visibility. No cultural material was observed. The other survey area included two expanded locations, as well as linear sections connecting the two. Portions of the survey area were behind a chain-link fence, so both sides of the fence were surveyed where possible. The open space area was covered in oak and chapparal, as well as poison oak and non-native grasses. The edges of the proposed project site included slopes greater than 30 degrees where survey was not possible; all other areas were surveyed, including two drainages and a knoll above the southern drainage. More than 98% of the proposed project site is within the open space; 2% is north and west of the chain-link fence and has retaining walls and paved sections. Ground surface visibility within the proposed project site ranged from fair to good, depending on density of ground cover. Basalt bedrock outcrops and weathering volcanic rocks are abundant throughout the proposed project site. No cultural material was observed. Soils observed consist of brown to dark gray-brown sandy loams, with abundant angular rock and gravels. These soils appear consistent with the description of Hambright very rocky loam, 15% slopes. a) Would the project cause a substantial adverse change in the significance of a historical resource pursuant to §15064.5? No Impact. As part of the cultural resources study prepared for the proposed project (Appendix C1), the results of a CHRIS records search of the project site and a 0.5-mile radius were reviewed. The CHRIS archaeological resources and historic built-environment resources, Department of Parks and Recreation site records, technical reports, archival resources, and ethnographic references. The SCCIC records were reviewed to determine whether the implementation of the project would have the potential to impact known and unknown cultural resources. With respect to historical resources, the SCCIC records indicate that no built environment resources or known archaeological resources meeting the criteria of a historical resource pursuant to Section 15064.5 have been previously recorded within 0.5 miles of the project site.

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Although CEQA includes archaeological resources in the definition of historical resources, for purposes of this analysis, impacts to archaeological resources not meeting the criteria of a historical resource pursuant to Section 15064.5 are not addressed in Threshold 3.5(a). Please see Threshold 3.5(b) for analysis and findings addressing the potential for impacts to known unique archaeological resources, unidentified unique archaeological resources, and unidentified archaeological resources that may have the potential to meet the criteria of a historical resource pursuant to Section 15064.5. Background analysis revealed that the Treatment Plant property was originally developed in 1961 and several buildings and structures within the Treatment Plant property are over 45 years old. Therefore, the property as a whole was evaluated for historical significance, by Secretary of Interior-qualified architectural historians, in order to determine if there would be an impact to historical resources under CEQA. Efforts to identify historical resources within and adjacent to the project site, in addition to a review of the CHRIS records search results, included the following components: study area delineation; an intensive-level survey of the study area for built environment resources; archival and building development research; and the evaluation of properties for the National Register of Historic Places, CRHR, and City of Thousand Oaks Landmark and Point of Historical Interest eligibility criteria and integrity requirements. The investigation resulted in conclusion that the Treatment Plant property does not meet any eligibility requirement under national, State, or local designation criteria and the property is not considered a historical resource under CEQA. Therefore, determination of whether the project may cause a substantial adverse change in the significance of a historical resource pursuant to Section 15064.5 is no impact. b) Would the project cause a substantial adverse change in the significance of an archaeological resource pursuant to §15064.5? Less-than-Significant Impact with Mitigation Incorporated. As mentioned previously, a CHRIS records search of the project site and a 0.5-mile radius was conducted, the results of which revealed that that 19 previous cultural resource studies have been conducted within 0.5 miles of the proposed project site between 1975 and 2006. As a result of these studies stored in the CHRIS database and additional studies, eight cultural resources, including seven prehistoric archaeological resources and one historic archaeological resource, have been previously recorded within 0.5 miles of the project site. Although none of these resources are located within or adjacent to the project site, at least one of the prehistoric archaeological sites is located within 50 meters (165 feet) of the project site. The areas proposed for ground-disturbing improvements were surveyed for archaeological resources and evidence for the potential presence of archaeological resources. As mentioned previously, the results of the pedestrian survey conducted under less-than-reliable conditions (due to lack of access and existing pavement) were negative. The project site was constructed in 1961 prior to the enactment of cultural resource laws requiring the assessment of impacts to cultural resources; as a result, no pedestrian survey allowing for observation of native soils prior to development of the plant was conducted and the presence of cultural deposits is unknown. Given the presence of known archaeological sites within close proximity of the project site, the obscured nature of surface soils within the proposed improvement areas preventing the observation of native soils, and that portions of the proposed improvement areas area located within previously undisturbed soils, the potential to encounter unknown intact subsurface archaeological deposits and/or features is moderate during ground-disturbing activities within native soil. Additionally, this determination is consistent with previously conducted cultural assessments of the project property and surrounding area. In the event that unanticipated archaeological resources are encountered during project implementation, impacts to these resources would be potentially significant. Therefore, MM-CUL-1 (Cultural Resource

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Monitoring and Inadvertent Discovery Plan), MM-CUL-2 (Worker Environmental Awareness Program Training), MM-CUL-3 (Archaeological Monitoring), and MM-CUL-4 (Inadvertent Discovery Clause) shall be implemented to reduce potential impacts to unanticipated archaeological resources. Implementation of MM-CUL-1 through MM-CUL-4 would reduce potential impacts pertaining to the inadvertent discovery of archaeological resources to less than significant with mitigation incorporated. Mitigation Prior to commencement of construction activities for all phases of project implementation, the City shall retain a qualified archaeological principal investigator who meets Professional Qualification Standards for Archaeology, is approved by the City, and has experience and is well-acquainted with the history of the ancestral tribes geographically connected to the project site (referred ). MM-CUL-1 Cultural Resource Monitoring and Inadvertent Discovery Plan. The City of Thousand Oaks shall retain a Principal Investigator/Archaeologist to assess information available (final grading and construction plans, geotechnical testing results, as-built plans, etc.) and determine the depth at which native soils exist and would be impacted by project implementation. The depth of native soils shall be included in the cultural resource monitoring and inadvertent discovery plan (Plan) so as to guide when monitoring is required. Impacts to cultural resources shall be minimized through implementation of pre- and post-construction tasks. Tasks pertaining to cultural resources include the development of the Plan. The purpose of the Plan is to outline a program of treatment and mitigation in the case of an inadvertent discovery of cultural resources during ground-disturbing activities and to provide for the proper identification, evaluation, treatment, and protection of any cultural resources throughout the duration of the project. This Plan shall define the process to be followed for the identification and management of cultural resources in the project area during construction. Existence of and importance of adherence to this Plan shall be stated on all project site plans intended for use by those conducting the ground-disturbing activities. The Plan shall also include the conditions under which monitoring is required pursuant to MM-CUL-3 and the manner of facilitation. MM-CUL-2 Worker Environmental Awareness Program Training. Prior to commencement of construction activities for all phases of project implementation, the City of Thousand Oaks shall retain a Principal Investigator/Archaeologist to prepare a Worker Environmental Awareness Program (WEAP). The WEAP shall be submitted to the City of Thousand Oaks for review and approval. All construction personnel and monitors who are not trained archaeologists shall be briefed regarding inadvertent discoveries prior to the start of construction activities. A basic presentation and handout or pamphlet shall be prepared to ensure proper identification and treatment of inadvertent discoveries. The purpose of the WEAP training is to provide specific details on the kinds of archaeological materials and Tribal Cultural Resources that may be identified during construction of the project and explain the importance of and legal basis for the protection of significant archaeological resources. Each worker shall also learn the proper procedures to follow in the event that cultural resources, Tribal Cultural Resources, or human remains are uncovered during ground-disturbing activities. These procedures shall include work curtailment or redirection, and the immediate

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contact of the site supervisor and archaeologist retained for the project. This requirement shall be noted on all construction plans to ensure implementation. MM-CUL-3 Archaeological Monitoring. An archaeological technician/monitor overseen by a Principal Investigator/Archaeologist shall observe ground-disturbing activities during initial excavation in native soils. Initial excavation is defined as initial construction-related earthmoving of sediments from their place of deposition. As it pertains to archaeological monitoring, this definition excludes movement of sediments after they have been initially disturbed or displaced by project-related construction. A Principal Investigator/ Archaeologist shall oversee and establish monitoring efforts as needed (increase, decrease, or discontinue monitoring frequency) based on the observed potential for construction activities to encounter cultural deposits or material. The archaeological monitor shall be responsible for maintaining daily monitoring logs. This requirement shall be noted on all construction plans to ensure implementation. Upon completion of all ground-disturbing activities, an archaeological monitoring report shall be prepared within 60 days following completion of ground disturbance and submitted to the City of Thousand Oaks for review. This report shall document compliance with approved mitigation, all conducted monitoring efforts, and include an appendix with daily monitoring logs. The final report shall be submitted to the City of Thousand Oaks and the applicable California Historical Resources Information System information center. MM-CUL-4 Inadvertent Discovery Clause. In the event that potential prehistoric or historic-era archaeological resources and/or Tribal Cultural Resources (sites, features, or artifacts) are exposed during construction activities for the project, all construction work occurring not less than 50 feet of the find shall immediately stop and the Principal Investigator/ Archaeologist must be notified immediately to assess of the discovery and determine whether additional study is warranted. Depending upon the nature of the discovery, the Principal Investigator/Archaeologist may simply record the find and allow work to continue. If the discovery proves potentially significant under the California Environmental Quality Act (CEQA), additional work such as subsurface testing may be warranted. If the discovery is determined significant under CEQA and avoidance is not feasible, data recovery will be required. In the event that human remains are inadvertently encountered during construction activities, the remains and associated resources shall be treated in accordance with State and local regulations that provide requirements with regard to the accidental discovery of human remains, including California Health and Safety Code Section 7050.5, California Public Resources Code Section 5097.98, and CEQA Guidelines Section 15064.5(e). In accordance with these regulations, if human remains are found, the County Coroner must be immediately notified of the discovery. No further excavation or disturbance of the project site or any nearby (no less than 100 feet) area reasonably suspected to overlie adjacent remains shall occur until the County Coroner has determined if the remains are potentially human in origin. If the County Coroner determines that the remains are, or are believed to be, Native American, he or she is required to immediately notify the Native American Heritage Commission (NAHC). The NAHC must immediately notify those persons it believes

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to be the most likely descendant from the deceased Native American. The most likely descendant must then complete their inspection and determine, in consultation with the property owner, the treatment and disposition of the human remains. c) Would the project disturb any human remains, including those interred outside of formal cemeteries? Less-than-Significant Impact with Mitigation Incorporated. No prehistoric or historic burials were identified within the project site as a result of the CHRIS records search, NAHC SLF search, or pedestrian survey, nor are there any dedicated cemeteries within or surrounding the project site. The project site was constructed in 1961 prior to the enactment of cultural resource laws requiring the assessment of impacts to cultural resources; as a result, no pedestrian survey allowing for observation of native soils prior to development of the Treatment Plant was conducted and the presence of cultural deposits is unknown. Given the presence of known archaeological sites within close proximity of the project site, the obscured nature of surface soils within the proposed improvement areas preventing the observation of native soils, and that portions of the proposed improvement areas area located within previously undisturbed soils, the potential to encounter previously unknown human remains exists. Therefore, MM-CUL-1 (Cultural Resource Monitoring and Inadvertent Discovery Plan), MM-CUL-2 (Worker Environmental Awareness Program Training), MM-CUL-3 (Archaeological Monitoring), and MM-CUL-4 (Inadvertent Discovery Clause) shall be implemented to reduce potential impacts to human remains. Implementation of MM-CUL-1 through MM-CUL-4 would reduce potential disturbance to any human remains to less than significant with mitigation incorporated. 3.6 Energy Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact VI. Energy Would the project:a) Result in potentially significant environmental impact due to wasteful, inefficient, or unnecessary consumption of energy resources, during project construction or operation? b) Conflict with or obstruct a State or local plan for renewable energy or energy efficiency?

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a) Would the project result in potentially significant environmental impact due to wasteful, inefficient, or unnecessary consumption of energy resources, during project construction or operation? Less-than-Significant Impact. Construction Energy Use Electricity Temporary electric power for as-necessary lighting and electronic equipment would be provided by the existing Treatment Plant site. The amount of electricity used during construction would be minimal because typical demand would stem from electrically powered hand tools and no trailers are anticipated. The electricity used for construction activities would be temporary and minimal. Natural Gas Natural gas is not anticipated to be required during construction of the proposed project. Fuels used for construction would primarily consist of diesel and gasoline, which are discussed under the subsection at may be consumed as a result of proposed project construction would be temporary and negligible. Petroleum Petroleum would be consumed throughout construction. Fuel consumed by construction equipment would be the primary energy resource expended over the course of construction. Transportation of construction materials and construction workers would also result in petroleum consumption. Heavy-duty construction equipment, vendor trucks, and haul trucks would use diesel fuel. Construction workers would likely travel to and from the project area in gasoline-powered vehicles. Construction is expected to take approximately 6 months during 2025. While construction petroleum consumption is temporary and short, it was estimated for disclosure as shown in Table 3-12. Petroleum emissions associated with the use of construction equipment and vehicles, which were used to calculate gallons of petroleum consumed, were calculated using CalEEMod and are provided in Appendix A. Fuel consumption from construction equipment and vehicles was estimated by converting the total carbon dioxide (CO2) emissions from each construction phase to gallons using the conversion factors for CO2 to gallons of gasoline or diesel. The conversion factor for gasoline is 8.78 kilograms per metric ton (MT) CO2 per gallon, and the conversion factor for diesel is 10.21 kilograms per MT CO2 per gallon (The Climate Registry 2022). The estimated diesel fuel usage from construction equipment, haul trucks, and vendor trucks, as well as the estimated gasoline fuel usage from worker vehicles, is shown in Table 3-12. Appendix A A lists the assumed equipment usage and vehicle trips.

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Table 3-12. Total Project Construction Petroleum Demand Project Off-Road Equipment (Diesel) Haul Trucks (Diesel) Vendor Trucks (Diesel) Worker Vehicles (Gasoline) Gallons 2025 8,344 673 726 1,093 Total 8,344 673 726 1,093 Source: Appendix A. In total, project construction fuel consumption would be approximately 1,093 gallons of gasoline and 9,743 gallons of diesel. Because of the short-term nature of construction and relevantly small scale of the project, project construction would not result in wasteful, inefficient, or unnecessary consumption of electricity, natural gas, or petroleum, and impacts related to construction would be less than significant. Operational Energy Use As discussed in Section 3.3, Air Quality, once project construction is complete, the project would continue providing wastewater treatment services for the City. No net increase in operational activities associated with the project would occur (i.e., no routine daily equipment operation, vehicle trips, or energy consumption would be required). Because the project would not result in any long-term operational activities, there would be no potential impact associated with operational energy. Conclusion Based on the previous considerations, the project would result in a less-than-significant energy impact. b) Would the project conflict with or obstruct a State or local plan for renewable energy or energy efficiency? Less-than-Significant Impact. The project would be subject to State regulations for energy efficiency to the extent applicable. Because the project does not include newly constructed structures or alterations of existing buildings, the California Building Energy Efficiency Standards and California Green Building Standards, both of which are set forth in the California Code of Regulations, Title 24, would not apply. Because the project does not include routine operational vehicle trips, at a regional level, the project would be also not be RTP/SCS, Connect SoCal. Nonetheless, to the extent applicable, construction of the project would follow relevant energy standards and regulations. As such, the proposed roject would not conflict with existing energy standards and regulations and impacts would be less than significant.

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3.7 Geology and Soils Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact VII. GEOLOGY AND SOILS Would the project: a) Directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury, or death involving: i) Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42. ii) Strong seismic ground shaking? iii) Seismic-related ground failure, including liquefaction? iv) Landslides? b) Result in substantial soil erosion or the loss of topsoil? c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse? d) Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial direct or indirect risks to life or property? e) Have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water? f) Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature?

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a) Would the project directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury, or death involving: i) Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42. Less-than-Significant Impact. The project site is not located within an Alquist-Priolo Earthquake Fault Zone. The nearest Alquist-Priolo Earthquake Fault Zone is the Simi-Santa Rosa Fault Zone, which runs in a generally east-west direction approximately 1.75 miles north of the project site at its nearest point (CGS 2023). Due to the distance of the active faults from the site, fault rupture is not anticipated. As such, impacts would be less than significant. ii) Strong seismic ground shaking? Less-than-Significant Impact. Like the rest of Southern California, the project site is located in a seismically active region and, as such, would be subject to seismic ground shaking. As described in Threshold 3.7a(i) above, the closest fault zone to the project site is the Simi-Santa Rosa Fault Zone, which has the potential to produce an estimated maximum moment magnitude (Mw) 6.8 earthquake (DeVecchio et al. 2012). However, the project involves stormwater conveyance infrastructure improvements to an existing wastewater treatment facility and would not involve the construction of habitable structures that would put people at risk of collapse during a seismic event or increase the number of people exposed to existing seismic hazards. Additionally, the project would be designed and constructed to resist seismic forces in accordance with the criteria contained in the California Building Code. Through compliance with the relevant building standards, the hazards associated with strong seismic ground shaking would be minimized to the extent practical. Furthermore, the implementation of the proposed project would not increase the probability of or exacerbate the potential for strong seismic ground shaking to occur. As such, impacts would be less than significant. iii) Seismic-related ground failure, including liquefaction? Less-than-Significant Impact. The project site is located in a liquefaction zone (CGS 2023). However, the project involves stormwater conveyance infrastructure improvements to an existing wastewater treatment facility. The project would not involve the construction of habitable structures that would put people at risk of ground failure or increase the number of people exposed to ground failure risk. Additionally, the project would be designed and constructed in accordance with applicable standards based on conditions to resist the effects of liquefaction. Through compliance with the relevant building standards, the hazards associated with ground failure and liquefaction would be minimized to the extent practical. Furthermore, the implementation of the proposed project would not increase the probability of or exacerbate the potential for seismic-related ground failure to occur. As such, impacts would be less than significant. iv) Landslides? Less-than-Significant Impact. The project site is located in a landslide zone (CGS 2023). However, the project involves stormwater conveyance infrastructure improvements to an existing wastewater treatment facility. The project would not involve the construction of habitable structures that would put people at

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landslide risk or increase the number of people exposed to landslide risk. Additionally, the project would be designed and constructed in accordance with applicable standards conditions taking into account its location within a landslide zone. Through compliance with the relevant building standards, the hazards associated with landslide would be minimized to the extent practical. Furthermore, the implementation of the proposed project would not increase the probability of or exacerbate the potential for a landslide to occur. As such, impacts would be less than significant. b) Would the project result in substantial soil erosion or the loss of topsoil? Less-than-Significant Impact. Under existing conditions, the project site is located at the confluence of two watersheds and experiences flooding after large storm events. These storm events result in soil erosion upstream of the project site, which is transported to the project site where it collects behind a concrete swale and requires subsequent removal. The project would modify the Treatment Paccommodate storm flows and the associated debris, including eroded soil. It would include a debris basin at the upstream end of the eastern side of the Treatment Plant to intercept all debris and allow clear water flows to continue downstream into the storm drain system. As such, the project would accommodate existing soil erosion occurring upstream of the project site and would not contribute to additional erosion or loss of topsoil. As such, impacts would be less than significant. c) Would the project be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse? Less-than-Significant Impact. As described in Threshold 3.7a(iii) and Threshold 3.7a(iv) above, the project site is located within a liquefaction and landslide zone. However, as described throughout this section, the project would not involve the construction of habitable structures that would put people at risk, would not increase the number of people exposed to geologic hazards, would not exacerbate or contribute to existing instability, and would be designed and constructed in accordance with applicable standards based on the specific geologic conditions of the project site to minimize geologic hazard risks. As such, impacts would be less than significant. d) Would the project be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial direct or indirect risks to life or property? Less-than-Significant Impact. The project site is in an area identified as having moderate expansive soils (City of Thousand Oaks 2014). However, the project is limited to drainage improvements at an existing wastewater treatment facility and would not involve the construction of habitable structures or increase the number of people exposed to expansive soils. As such, impacts would be less than significant. e) Would the project have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water? No Impact. The project would not include septic tanks or alternative wastewater disposal systems. As such, no impact would occur.

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f) Would the project directly or indirectly destroy a unique paleontological resource or site or unique geologic feature? Less-than-Significant Impact With Mitigation Incorporated. Paleontological resources are the , per the Society of Vertebrate Paleontology (SVP 2010) guidelines, are older than written history or older than approximately 5,000 years. They are limited, nonrenewable resources of scientific and educational value, which are afforded protection under State laws and regulations. The project site is located within the Transverse Ranges Geomorphic Province, which extends from Point Conception in the west to the San Bernardino Mountains in the east. The province also includes the San Gabriel, Santa Monica, and Santa Ynez Mountains and the offshore San Miguel, Santa Rosa, and Santa Cruz Islands (CGS 2002; Morton and Miller 2006). This geomorphic province structure is east-west trending and is oblique to the normal northwest trend of coastal California. More specifically and according to surficial geological mapping by Dibblee and Ehrenspeck (1990) at a 1:24,000 scale and the International Chronostratigraphic Chart of Cohen et al. (2022), the project site is underlain by Holocene (<11,700 years ago) alluvial deposits (map unit Qa) and middle Miocene (approximately 11.63 to 15.97 million years ago) Conejo Volcanics (map unit Tcvb). Holocene alluvial deposits are typically an unconsolidated mixture of clay, silt, sand, and gravel; and the Conejo Volcanics is composed of extrusive basalts in this area (Dibblee and Ehrenspeck 1990). Dudek requested a paleontological records search from the Natural History Museum of Los Angeles County (NHMLA) on February 21, 2023, and the results were received on March 5, 2023. The NHMLA reported no fossil localities from within the project site; however, they did report nearby Pleistocene (approximately 11,700 years ago to 2.6 million years ago) vertebrate fossil localities and invertebrate localities from the Conejo Volcanics (NHMLA 2023). While Pleistocene sedimentary deposits are not mapped on the surface of the project site, they often underlie Holocene sedimentary deposits at variable depths. The closest locality (LACM VP [Los Angeles County Museum Vertebrate Paleontology]) 1680) produced a fossil mammoth (Mammuthus) and horse (Equidae) from 14 to 15 feet below ground surface within silty clay Pleistocene deposits in the Conejo Valley, approximately 1 mile northwest of Newberry Park (NHMLA 2023). A fossil mastodon (Mammut americanum) (LACM VP 7660) was collected on the surface of a stream bed near the Lakes at Thousand Oaks. Fossil locality LACM VP 3213, consisting of ground sloth (Paramylodon) and other vertebrates, was recovered from an unknown depth below ground surface within Pleistocene alluvial deposits along Westlake Boulevard (NHMLA 2023). Finally, the LACM reported unspecified invertebrates (LACM IP [invertebrate paleontology] 1692416926 and 16927) from an unknown depth below ground surface within the Cities of Calabasas and Agoura Hills and oyster beds (LACM IP 17148), also from an unknown depth, in the western Simi Hills. Both invertebrate localities were discovered in areas underlain by Conejo Volcanics. The surficial Holocene alluvial deposits, aged less than 11,700 years ago, have not been shown to produce any fossil resources and therefore have low paleontological sensitivity on the surface that increases with depth, where they can become old enough to preserve significant paleontological resources. While volcanic rocks do not normally preserve fossils, sedimentary portions of the Conejo Volcanics have produced significant paleontological resources. No paleontological resources were identified within the project site as a result of the institutional records search and desktop geological and paleontological review, and the project site is not anticipated to be

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underlain by unique geologic features. The Holocene alluvial deposits mapped within the project site are not known to produce significant paleontological resources because of their young age and are considered to have low paleontological resource sensitivity at shallow depths that increases to high with depth where they become old enough to contain fossils. Sedimentary portions of the Conejo Volcanics have produced invertebrate fossils and have high paleontological resource sensitivity. Artificial fill, if present, has no paleontological resource sensitivity. In the event that intact paleontological resources are located on the project site, ground-disturbing activities associated with construction of the project, such as grading during site preparation and trenching for pipelines or utilities, have the potential to destroy a unique paleontological resource or site. Without mitigation, the potential damage to paleontological resources during construction would be a potentially significant impact. However, upon implementation of MM-GEO-1 (Paleontological Resources Impact Mitigation Program and Paleontological Monitoring), impacts would be reduced to below a level of significance. Impacts of the proposed project are considered less than significant with mitigation incorporated during construction. MM-GEO-1 Paleontological Resources Impact Mitigation Program and Paleontological Monitoring. Prior to commencement of any grading activity on site, the applicant shall retain a qualified paleontologist per the Society of Vertebrate Paleontology (2010) guidelines. The qualified paleontologist shall prepare a Paleontological Resources Impact Mitigation Program (PRIMP) for the proposed project. The PRIMP shall be consistent with the Society of Vertebrate Paleontology (2010) guidelines and outline requirements for pre-construction meeting attendance and worker environmental awareness training. The PRIMP shall include where paleontological monitoring is required within the project site based on construction plans and/or geotechnical reports and also include procedures for adequate paleontological monitoring and discoveries treatment, paleontological methods (including sediment sampling for microinvertebrate and microvertebrate fossils), reporting, and collections management. The qualified paleontologist shall attend the pre-construction meeting and a qualified paleontological monitor shall be on site during initial rough grading and other significant ground-disturbing activities (including augering) in previously undisturbed Conejo Volcanics and below a depth of 5 feet below the surface in areas underlain by Holocene alluvial deposits. The qualified paleontological monitor shall also be on site during excavations to determine if the sedimentary portion of the Conejo Volcanics is being exposed and/or the Holocene alluvial deposits are old enough at depth to contain fossils. The qualified paleontologist shall determine how much monitoring is necessary based on subsurface conditions. In the event that paleontological resources (e.g., fossils) are unearthed during grading, the paleontological monitor will temporarily halt and/or divert grading activity to allow recovery of paleontological resources. The area of discovery will be roped off with a 50-foot radius buffer. Once documentation and collection of the find is completed, the monitor will allow grading to recommence in the area of the find.

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3.8 Greenhouse Gas Emissions Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact VIII. GREENHOUSE GAS EMISSIONS Would the project: a) Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment? b) Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of greenhouse gases? a) Would the project generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment? Less-than-Significant Impact. The greenhouse effect is a natural process that contributes to regulating additional greenhouse gas (GHG) emissions to the atmosphere increase the amount of infrared radiation that gets absorbed before escaping into space, thus enhancing the greenhouse effect and causing the this impact through its incremental contribution combined with the cumulative increase of all other sources of GHGs. Thus, GHG impacts are recognized exclusively as cumulative impacts (CAPCOA 2008). As defined in California Health and Safety Code Section 38505(g) for purposes of administering many of the S2, methane (CH4), nitrous oxide (N2O), hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride. The four GHGs evaluated for GHG emission impacts are CO2, CH4, N2O, and refrigerants. Hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride were not evaluated or estimated in this analysis because the project would not generate them in measurable quantities. Individual projects do not generate sufficient GHG emissions to influence climate change directly. However, physical changes caused by a project can contribute incrementally to significant cumulative effects, even if individual changes resulting from a project are limited. The issue of climate change typically involves an analysis of considerable. nificant when viewed in connection with the effects of past projects, other current projects, and probable future projects (14 CCR 15064[h][1]). While the City has taken steps toward development of a Climate Action Plan, the City has not formally adopted a Climate Action Plan or other GHG reduction plan that addresses community-wide emissions to date, which individual projects could use to tier from per CEQA Guidelines Section 15183.5(b). The VCAPCD

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has not established quantitative significance thresholds for evaluating GHG emissions in CEQA analyses, but it recommends using the CEQA and Climate Change: Addressing Climate Change through California Environmental Quality Act white paper (CAPCOA 2008) and other resources when developing GHG evaluations (VCAPCD 2006). The CEQA and Climate Change paper provides a common platform of information and tools to support local governments and was prepared as a resource, not as a guidance document. CEQA Guidelines Section 15064.4 expressly provides that discretion -to CEQA Guidelines Section 15064.4 that took effect in December 2018 further state that a lead agency evolving scientific In light of the lack of a specific GHG threshold or qualified GHG reduction plan recommended or adopted by the City or VCAPCD, it is appropriate to refer to guidance from other agencies when discussing GHG emissions. The City generally refers to the South Coast Air Quality Management District (SCAQMD) methodology for GHG significance analysis. The SCAQMD formed a GHG CEQA Significance Threshold Working Group to work with SCAQMD staff on developing GHG CEQA significance thresholds until Statewide significance thresholds or guidelines are established. In December 2008, the SCAQMD adopted an interim 10,000 MT of CO2 equivalent (CO2e) per year screening level threshold for stationary source/industrial projects for which the SCAQMD is the lead agency. From December 2008 to September 2010, the SCAQMD hosted Working Group meetings and revised the draft threshold proposal several times, although it did not officially provide these proposals in a subsequent document. The SCAQMD has continued to consider adoption of significance thresholds for general land use development projects. The most recent proposal, issued in September 2010, uses the following tiered approach to evaluate potential GHG impacts from various uses (SCAQMD 2010): Tier 1 Determine if CEQA categorical exemptions are applicable. If not, move to Tier 2. Tier 2 Consider whether or not the proposed project is consistent with a locally adopted GHG reduction plan that has gone through public hearing and CEQA review, that has an approved inventory, includes monitoring, etc. If not, move to Tier 3. Tier 3 Consider whether the project generates GHG emissions in excess of screening thresholds for individual land uses. The 10,000 MT CO2e per year threshold for industrial uses would be recommended for use by all lead agencies. Under option 1, separate screening thresholds are proposed for residential projects (3,500 MT CO2e per year), commercial projects (1,400 MT CO2e per year), and mixed-use projects (3,000 MT CO2e per year). Under option 2, a single numerical screening threshold of 3,000 MT CO2e per year would be used for all non-industrial projects. If the project generates emissions in excess of the applicable screening threshold, move to Tier 4.2 2 To evaluate whether a project may generate a quantity of GHG emissions with the potential to have a significant impact on the environment, some local air districts have developed bright-line significance thresholds. Bright-line significance thresholds are numeric mass emissions thresholds that identify the level at which additional analysis of project GHG emissions is necessary. If ould be less than significant.

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Tier 4 Consider whether the project generates GHG emissions in excess of applicable performance standards for the project service population (population plus employment). The efficiency targets were established based on the goal of AB 32 to reduce statewide GHG emissions to 1990 levels by 2020. The 2020 efficiency targets are 4.8 MT CO2e per service population for project level analyses and 6.6 MT CO2e per service population for plan level analyses. If the project generates emissions in excess of the applicable efficiency targets, move to Tier 5. Tier 5 Consider the implementation of CEQA mitigation (including the purchase of GHG offsets) to reduce the project efficiency target to Tier 4 levels. The City understands that the Tier 3 numeric thresholds were proposed a decade ago and were never adopted. However, the 3,000 MT CO2e per year threshold was developed and recommended by SCAQMD, an expert agency, based on substantial evidence as provided in the Draft Guidance Document Interim CEQA Greenhouse Gas Significance Threshold (SCAQMD 2008) and subsequent Working Group meetings (latest in 2010). This threshold uses the Executive Order S-3-05 goal as the basis, so it is not tied to only the 2020 target year and is thus not outdated. This threshold is also based on the 90% capture rate methodology, which means that 90% of total emissions from all new or modified projects would be subject to some type of CEQA analysis, which was the approach taken by SCAQMD to establish the stationary/industrial source threshold, as well as by CARB (for interim threshold for stationary source projects); it was also one of the options suggested by the California Air Pollution Control Officers Association (quantitative threshold based on market capture). Further, this threshold has been used for hundreds, if not thousands, of GHG analyses performed for projects located within the SCAQMD jurisdiction. The project is not residential or commercial, and it is also not an industrial project where the SCAQMD is the lead agency; as such, the recommended SCAQMD threshold to apply to the project is the 3,000 MT CO2e per year for all non-industrial projects. Per the SCAQMD guidance, construction emissions should be amortized over the operational life of the project, which is assumed to be 30 years (SCAQMD 2008). This impact analysis, therefore, adds amortized construction emissions to the estimated annual operational emissions and then compares operational emissions to the proposed SCAQMD threshold of 3,000 MT CO2e per year. Construction Emissions Construction of the project would result in GHG emissions, which are primarily associated with use of off-road construction equipment, on-road vendor and haul trucks, and worker vehicles. As previously stated, SCAQMD recommends that construction emissions be amortized over a 30-year project lifetime. CalEEMod was used to estimate GHG emissions during construction. Construction of the project is anticipated to last approximately 6 months. Table 3-13 shows the estimated annual GHG construction emissions associated with the project and the amortized construction emissions over a 30-year project life. Table 3-13. Estimated Annual Construction Greenhouse Gas Emissions Year CO2 CH4 N2O R CO2e Metric Tons per Year 2025 109 <0.01 <0.01 0.03 110 Total 110 Amortized 30-Year Construction Emissions 3.67

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Notes: CO2 = carbon dioxide; CH4 = methane; N2O = nitrous oxide; R = refrigerant; CO2e = carbon dioxide equivalent; <0.01 = reported value less than 0.01. See Appendix A for complete results. As shown in Table 3-13, the estimated total GHG emissions during construction would be approximately 110 MT CO2e over the construction period. Estimated project-generated construction emissions amortized over 30 years would be approximately 4 MT CO2e per year. As with project-generated construction air pollutant emissions, GHG emissions generated during construction of the proposed project would be short term in nature, lasting only for the duration of the construction period, and would not represent a long-term source of GHG emissions. As there is no construction GHG threshold, the amortized construction emissions are considered collectively with operation, below. Operational Emissions Once project construction is complete, the project would continue providing wastewater treatment services for the City. Similar to existing conditions, staff would occasionally visit the project site for routine maintenance or in the event of an emergency; however, no net increase in operational activities associated with the project would occur (no routine daily equipment operation, vehicle trips, energy consumption, water use or wastewater generation, solid waste generation, or refrigerants would be required). Because the project would not result in a net increase in long-term operational activities, there would be no potential GHG emissions impacts associated with operational GHG emissions. Conclusion As shown in Table 3-13, amortized project-generated construction emissions would be approximately 4 MT CO2e per year, which would not exceed the 3,000 SCAQMD threshold. Therefore, GHG emissions impacts would be less than significant. b) Would the project conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of greenhouse gases? Less-than-Significant Impact. The California State Legislature passed Assembly Bill (AB) 32 to provide S-range climate objectives. Since the passage of AB 32, the State of California has adopted GHG emissions reduction targets for future years beyond the initial 2020 horizon year. CARB is required to develop the Scoping Plan, which provides the framework for actions to achieve GHG emission targets. While the Scoping Plan is not directly applicable to specific projects, nor is it intended to be used for project-level evaluations,3 it is the official framework for the measures and regulations that will be implemented to 3 The Final Statement of Reasons for the amendments to the State CEQA Guidelines reiterates the statement in the Initial Statement ause it is conceptual at this stage and relies on the future development of regulations to implement the strategies identified in the

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found to not conflict with the statutes if it would meet the applicable Scoping Plan policies and would not impede attainment of the goals therein. For the project, the relevant GHG emissions reduction targets include those established by Senate Bill (SB) 32 and AB 1279, which require GHG emissions be reduced to 40% below 1990 levels by 2030, and 85% below 1990 levels by 2045, respectively. In addition, AB 1279 requires the State achieve net zero GHG 2017 Climate Change Scoping Plan Update was the first to address the S2030 GHG reduction target set forth in SB 32 (CARB 2017). The most recent 2022 Scoping Plan for Achieving Carbon Neutrality outlines the S2045 in alignment with AB 1279 and assesses progress toward the 2030 SB 32 target (CARB 2022b). As such, given that SB 32 and AB 1279 are the relevant GHG emission targets, the 2017 and 2022 Scoping Plan updates that outline the strategy to achieve those targets are the most applicable to the project. The 2017 Scoping Plan included measures to promote renewable energy and energy efficiency (including the mandates of SB 350), measures to increase stringency of the Low Carbon Fuel Standard, measures identified in the Mobile Source and Freight Strategies, measures identified in the proposed Short-Lived Climate Pollutant Plan, and measures to increase stringency of SB 375 targets. The 2022 Scoping Plan builds upon and accelerates programs currently in place, including moving to zero-emission transportation; phasing out use of fossil gas for heating homes and buildings; reducing chemicals and refrigerants with high global warming potential; providing communities with sustainable options for walking, biking, and public transit; and displacing fossil-fuel fired electrical generation through use of renewable energy alternatives (e.g., solar arrays and wind turbines) (CARB 2022b). The 2045 carbon neutrality goal required CARB to expand proposed actions in the 2022 Scoping Plan to include those that capture and store carbon in addition to those that only reduce anthropogenic sources of GHG emissions. Many of the measures and programs included in the Scoping Plan would result in the reduction of project-related GHG emissions with no action required at the project level, including GHG emission reductions through reduction in carbon intensity of transportation fuels (Low Carbon Fuel Standard) and the accelerated efficiency and electrification of the Statewide vehicle fleet (Mobile Source Strategy). Given that the project would generate no net increase in operational vehicle trips and associated mobile source GHG emissions, the pthrough reductions in VMT Statewide. Overall, the project includes a short duration of construction associated with proposed improvements and no operational activity that would result in a long-term source of GHG emissions. Accordingly, the project would not conflict with the State of Californiaits GHG reduction goals. Of note, the 2022 Scoping Plan emphasizes that reliance on carbon sequestration in the Sand working lands will not be sufficient to address residual GHG emissions, and achieving carbon neutrality will require research, development, and deployment of additional methods to capture atmospheric GHG emissions (e.g., mechanical direct air capture). Given that the specific path to neutrality will require development of technologies and programs that are not currently known or available, the ps role in supporting the Statewide goal would be speculative and cannot be wholly identified at this time.

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Overall, the project would comply with all regulations adopted in furtherance of the Scoping Plan to the extent applicable and required by law. The project would neither updates nor with the S Connect SoCal 2045 RTP/SCS, also referred to as Connect SoCal, is a regional growth-management strategy that targets per capita GHG reduction from passenger vehicles and light-duty trucks in the Southern California region (SCAG 2020). The RTP/SCS strives to integrate land use and transportation strategies that are forecasted to achieve reduction in GHG emissions to achieve the Sreduction goals. Connect SoCal incorporates local land use projections and circulation networks in city and county general plans. The following strategies are intended to be supportive of implementing the 20202045 RTP/SCS and reducing GHGs: focus growth near destinations and mobility options; promote diverse housing choices; leverage technology innovations; support implementation of sustainability policies; and promote a green region. Typically, a project would be consistent with the RTP/SCS if the project does not exceed the underlying growth assumptions within the RTP/SCS and would support the overall applicable goals of the RTP/SCS. Because the project requires short-term construction activities only with no routine, operational activities, including operational vehicle trips, the project would neither conflict with the RTP/SCS strategies listed above that are applicable to land use development operation, nor would it represent a net increase in VMT. Therefore, the project would not conflict with implementation of the strategies identified in the 2020 RTP/SCS that would reduce GHG emissions. Conclusion Based on the previous considerations, the project would not conflict with an applicable plan, policy or regulation adopted for the purpose of reducing GHG emissions and impacts would be less than significant. 3.9 Hazards and Hazardous Materials Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact IX. HAZARDS AND HAZARDOUS MATERIALS Would the project: a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials? b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment?

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Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? d) Be located on a site that is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, would it create a significant hazard to the public or the environment? e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard or excessive noise for people residing or working in the project area? f) Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan? g) Expose people or structures, either directly or indirectly, to a significant risk of loss, injury or death involving wildland fires? a) Would the project create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials? Less-than-Significant Impact. Construction of the project would involve the use of small amounts of hazardous materials typically used for construction, such as fuels and greases, to fuel and service construction equipment. The small quantities of chemicals to be stored at the site during construction would be stored in appropriate containers in an enclosed and secured location, such as portable outdoor hazardous materials storage cabinets equipped with secondary containment to prevent contact with rainwater. The use, storage, transport, and disposal of hazardous materials used in construction would be completed in accordance with federal, State, and County regulations. Construction of the project is not anticipated to produce, use, store, transport, or dispose of extremely hazardous substances (i.e., those governed pursuant to 40 CFR 335). Material Safety Data Sheets for all applicable materials present on site would be made readily available to on-site personnel. Throughout construction, waste materials would be sorted on site and transported to appropriate waste management facilities. Nonhazardous construction materials that cannot be reused or recycled would likely be disposed of at municipal county landfills. Although not anticipated for the project, any hazardous waste and electronic waste would not be placed in a landfill but would be transported to a hazardous waste handling facility (e.g., electronic-waste recycling). Operation of the project would not involve the use of any hazardous materials. Therefore,

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through compliance with applicable regulations, the proposed project would not create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials and impacts would be less than significant. b) Would the project create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment? Less-than-Significant Impact. As noted above, construction of the proposed project would involve the use of small amounts of hazardous materials, such as fuels and greases to fuel and service construction equipment. Improper handling and storage of these hazardous materials could result in accidental release if not managed appropriately. The small quantities of chemicals to be stored at the project site during construction would be stored in appropriate containers, in an enclosed and secured location, such as portable outdoor hazardous materials storage cabinets equipped with secondary containment to prevent contact with rainwater. Additionally, a SWPPP would be required for construction of the project, which would include a list of potential pollutants (i.e., hazardous materials, fugitive dust, sediment, concrete waste) and also include best management practices (BMPs) to prevent and limit these pollutants from reaching stormwater runoff. See Section 3.10, Hydrology and Water Quality, for a detailed discussion of SWPPPs. Operation of the project would not involve the use of any hazardous materials. Therefore, through compliance with SWPPP BMPs during construction, the proposed project would not create a significant hazard to the public or the environment through the reasonably foreseeable upset or accident conditions involving the release of hazardous materials into the environment and impacts would be less than significant. c) Would the project emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? No Impact. The project site is not located within 0.25 miles of an existing or proposed school. The nearest school to the site is Passageway School, located approximately 1.25 miles southwest of the site. As such, there would be no impact. d) Would the project be located on a site that is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, would it create a significant hazard to the public or the environment? No Impact. A search of the regulatory database listings of hazardous materials sites was conducted by accessing the California Department of Toxic Substances Control (DTSC) EnviroStor Hazardous Waste and Substances Sites (Cortese) List (DTSC 2022). The project site is not listed on the Hazardous Waste and Substances Sites List from DTSC (DTSC 2022). The site did contain a leaking underground storage tank, according to the List of Leaking Underground Storage Tank Sites from the State Water Resources Control Board (SWRCB 2022a). However, the site has been remediated and the case was marked closed as of 2004 (SWRCB 2022b). Further, the project site is not listed on the list of solid waste disposal sites, nor is it listed on the list of active Cease and Desist Orders and Cleanup and Abatement Orders. Therefore, the project would not create a significant hazard to the public or the environment due to being located on a site that is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5, and there would be no impact.

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e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard or excessive noise for people residing or working in the project area? No Impact. The project site is not located within 2 miles of a public airport or public use airport. The nearest airport is the Camarillo Airport located approximately 8.3 miles east of the project site. As such, the proposed project would not result in a safety hazard or excessive noise for people residing or working in the project area. There would be no impact. f)Would the project impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan? No Impact. The project site is within the coverage area for several City and County emergency plans including the 2022 Ventura County Multi-Jurisdictional Hazard Mitigation Plan, the 2021 Ventura County Emergency Operations Plan, and the City of Thousand Oaks 2020 Emergency Operations Plan. As previously discussed, the project would involve drainage improvements on an existing stormwater treatment facility. These improvements would not impact circulation on the site. Additionally, the project site is not accessible to the public and does not contain any adjacent public rights-of-way. As such, the project would not impact any evacuation routes. Further, the project would be constructed and operated in compliance with all applicable local and State regulations. Therefore, the project would not physically interfere with an adopted emergency response plan or emergency evacuation plan, and there would be no impact. g) Would the project expose people or structures, either directly or indirectly, to a significant risk of loss, injury or death involving wildland fires? Less-than-Significant Impact with Mitigation Incorporated. The project is located in a Very High Fire Hazard Severity Zone in a Local Responsibility Area (CAL FIRE 2022). Construction would involve the temporary deployment of construction personnel to the project site and the use of combustion engine- powered equipment that has the potential to produce sparks that could ignite a fire, the spread of which could have significant impacts related to exposing people or structures, either directly or indirectly, to a significant risk of loss, injury or death involving wildland fires. The incorporation of MM-FIRE-1 (Construction Fire Prevention Plan) would reduce the potential impacts to less than significant. During operation, the project would not result in increased on-site employees and would not involve the operation of any mechanical equipment with the potential to produce sparks. As such, impacts associated with wildfire during operations would be less than significant with mitigation incorporated. See Section 3.20, Wildfire, for additional discussion and analysis related to wildfire impacts and for the full language of MM-FIRE-1.

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3.10 Hydrology and Water Quality Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact X. HYDROLOGY AND WATER QUALITY Would the project: a) Violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or ground water quality? b) Substantially decrease groundwater supplies or interfere substantially with groundwater recharge such that the project may impede sustainable groundwater management of the basin? c) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river or through the addition of impervious surfaces, in a manner which would: i) result in substantial erosion or siltation on- or off-site; ii) substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or offsite; iii) create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff; or iv) impede or redirect flood flows? d) In flood hazard, tsunami, or seiche zones, risk release of pollutants due to project inundation? e) Conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan? a) Would the project violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or ground water quality? Less-than-Significant Impact. Construction of the proposed project would include earthwork activities that could potentially result in erosion and sedimentation, which could subsequently degrade downstream receiving water and violate water quality standards. Stormwater runoff during the construction phase may contain silt and debris, resulting in a short-term increase in the sediment load of the on-site storm drain

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system. Substances such as oils, fuels, and solvents may be inadvertently spilled on the project site and subsequently conveyed via stormwater to nearby drainages, watersheds, and groundwater. However, because the project would result in more than 1 acre of ground disturbance, it would be subject to the National Pollutant Discharge Elimination System stormwater program, which includes obtaining coverage subject to the Construction General Permit include clearing, grading, and disturbances to the ground such as stockpiling or excavation. The Construction General Permit requires development and implementation of a SWPPP. Among the required items that must be included within a SWPPP are project design features intended to protect against substantial soil erosion as a result of water and wind erosion, commonly known as BMPs. The implementation of a Construction General Permit, including preparation of a SWPPP and implementation of BMPs, would reduce stormwater runoff during project construction impacts to acceptable levels. It follows that because construction of the project would not violate any water quality standards or waste discharge requirements, the project would not otherwise substantially degrade surface or groundwater quality. Therefore, short-term construction impacts associated with water quality would be less than significant. During operation, the project would operate as flood control infrastructure for improved handling of existing periodic flows to the Treatment Plant. Operation of the project would not involve the use of chemicals, result in any new discharges, or otherwise degrade surface water or groundwater quality. The project would result in some increase in impervious surface area within the project site. The increase of impervious surfaces would be minimal, however, and the stormwater captured by the project improvements would be outlet to the South Arroyo Conejo Creek, located to the west of the facility. Further, implementation of the proposed project is not anticipated to violate any water quality standards or waste discharge requirements, nor degrade surface water or groundwater quality. Therefore, impacts would be less than significant. b) Would the project substantially decrease groundwater supplies or interfere substantially with groundwater recharge such that the project may impede sustainable groundwater management of the basin? Less-than-Significant Impact. The proposed project would result in the development of improved flood control infrastructure at an existing wastewater treatment facility. Operation of the project would not involve the use of groundwater and would thus not decrease groundwater supplies. A portion of the project site is within the boundary of a paved, operating wastewater treatment facility. The project, however, does include development within an adjacent, undeveloped area. As such, the project would result in an increase of impervious surfaces on the site, when compared to existing conditions. Although the project would involve paving of some currently unpaved areas and thus increase the imperviousness of the project site, the increase would be minimal and would not interfere substantially with groundwater recharge. Upon project implementation, the proposed p-site flows to the South Arroyo Conejo Creek, as under existing conditions. Therefore, impacts would be less than significant.

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c) Would the project substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river or through the addition of impervious surfaces, in a manner which would: i) Result in substantial erosion or siltation on- or off-site? Less-than-Significant Impact. The Treatment Plant is located at the confluence of two watersheds and experiences flooding after large storm events that exceed the capacity of some drainage facilities for conveying off-site flows. The project would alter the drainage pattern within the limited footprint of the project site, including slightly increasing the amount of impervious surface. However, the project would not impact upstream drainage patterns and would improve flooding conditions and flows into the existing Treatment Plant. Construction activities would have the potential to cause ground surface disruption during grading and excavation, which could create the potential for erosion to occur. Construction would be required to implement erosion and sediment control BMPs. Implementation of required BMPs would minimize erosion during construction to the extent feasible. As such, construction impacts would be less than significant. During operation, the project would provide improved flood control on the site. As such, the project would not result in increased erosion or siltation on or off site. Additionally, the proposed project would allow for improved stormwater management on the site, which would therefore decrease the likelihood of on- and off-site erosion and siltation from occurring. As such, impacts would be less than significant. ii) Substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or offsite? No Impact. The proposed project would introduce improved drainage management infrastructure at a primarily developed site associated with an existing water Treatment Plant. The introduction of the pcomponents would result in a slight increase in the amount of impervious surface but would not increase the rate or amount of surface runoff. Alternatively, the project would serve to decrease flooding at the site during high runoff events, which would also decrease the likelihood of flooding occurring adjacent to the wastewater facility. Therefore, the project would not increase the rate or amount of surface runoff in a manner that would result in flooding on or off site, and there would be no impact. iii) Create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff? Less-than-Significant Impact. As addressed under Threshold 3.10(b)(ii), the proposed project would not increase the amount of on-site runoff at the project site. The proposed project would introduce improved stormwater drainage infrastructure at the site that would serve to better manage stormwater during high runoff events. The project would also not introduce substantial sources of pollution to the project site. Therefore, impacts would be less than significant. iv) Impede or redirect flood flows? Less-than-Significant Impact. As described above, the project would redirect flows within the limited footprint of the project site, including slightly increasing the amount of impervious surface. However, the project would

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not impact upstream drainage patterns and would improve flooding conditions and flows into the existing Treatment Plant. As previously discussed, the project site experiences flooding after large storm events, which requires subsequent cleanup and debris removal at the site. The project would increase the flood control capacity of the Treatment Plant and decrease the likelihood and intensity of flooding during storm events. Therefore, impacts associated with impeding or redirecting flood flows would be less than significant. d) In flood hazard, tsunami, or seiche zones, would the project risk release of pollutants due to project inundation? Less-than-Significant Impact. The project site is not located near the coast and would therefore not be subject to tsunamis. Additionally, the project site is not in close vicinity to a body of water that would be subject to seiche. The site does experience occasional flooding due to it being located at the confluence of two watersheds. These flood events result in debris buildup on the site, which must be cleaned up and removed. The project, however, would develop new pipes to improve on-site flows and decrease flooding within the site and a debris basin to contain flooding and the accompanying debris experienced after storm events. As such, the project would not risk release of pollutants due to project inundation in the event of floods, tsunamis, or seiche, and impacts would be less than significant. e) Would the project conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan? Less-than-Significant Impact. As discussed throughout Section 3.10, the proposed project would not result in substantial impacts to water quality and would not result in impacts to groundwater recharge or groundwater supplies. Therefore, the proposed project would not conflict or obstruct implementation of a water quality control plan or sustainable groundwater management plan, and impacts would be less than significant. 3.11 Land Use and Planning Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XI. LAND USE AND PLANNING Would the project: a) Physically divide an established community? b) Cause a significant environmental impact due to a conflict with any land use plan, policy, or regulation adopted for the purpose of avoiding or mitigating an environmental effect? a) Would the project physically divide an established community? No Impact. The project site consists of drainage improvements at an existing wastewater treatment facility. The facility contains no adjacent development and is surrounded on all sides by open space. The project would not include the development of any on- or off-site infrastructure that would physically divide any

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nearby communities. Further, the project would not permanently affect or impede the movement of pedestrians or vehicles. As such, no impact would occur. b) Would the project cause a significant environmental impact due to a conflict with any land use plan, policy, or regulation adopted for the purpose of avoiding or mitigating an environmental effect? No Impact. The project site is located in the municipal boundaries of the City. It has a zoning designation of Public, Quasi-Public, and Institutional Lands and Facilities (P-L) and the General Plan Land Use designation of Institutional. Under existing conditions, the project is a publicly owned and operated wastewater treatment facility, which is an allowed use under its zoning and land use designation. With the implementation of the project, the site would continue to operate as a wastewater treatment facility, and project would not conflict with a land use plan, policy, or regulation, and there would be no impact. 3.12 Mineral Resources Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XII. MINERAL RESOURCES Would the project: a) Result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the State? b) Result in the loss of availability of a locally-important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan? a) Would the project result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the State? No Impact. Additionally, the California Geologic Energy Management District WellFinder indicates the project site is not located within an oil or gas field, nor is there an active or plugged well on site. The closest wells are located approximately 3,000 and 4,700 feet northwest, both of which are plugged (CalGEM 2022). Given this, the implementation of the project would not result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the State. As such, no impact would occur. b) Would the project result in the loss of availability of a locally-important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan? No Impact. As stated under Threshold 3.12(a), tplanning area (City of Thousand Oaks 2013).

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Additionally, the project site is zoned as Institutional and has a land use designation of Public, Quasi-Public, and Institutional Lands, which precludes mining activities. Therefore, the implementation of the proposed project would not result in the loss of availability of a locally important mineral resource recovery site delineated on a local general plan, specific plan, or other land use plan. No impact would occur. 3.13 Noise Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XIII. NOISE Would the project result in: a) Generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? b) Generation of excessive groundborne vibration or groundborne noise levels? c) For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? Noise and Vibration Characteristics Noise Noise is defined as unwanted sound. Sound may be described in terms of level or amplitude (measured in decibels [dB]), frequency or pitch (measured in hertz or cycles per second), and duration (measured in seconds or minutes). The standard unit of measurement of the amplitude of sound is the decibel. Because the human ear is not equally sensitive to sound at all frequencies, a special frequency-dependent rating scale is used to relate noise to human sensitivity. The A-weighted decibel (dBA) scale performs this compensation by discriminating against low and very high frequencies in a manner approximating the sensitivity of the human ear. Several descriptors of noise (noise metrics) exist to help predict average community reactions to the adverse effects of environmental noise, including traffic-generated noise, on a community. These descriptors include the energy-equivalent sound level over a given period (Leq), the statistical sound level (Lxxent period for which the indicated level is exceeded), the day/night average sound level (Ldn), and the Community Noise Equivalent Level (CNEL). Table 3-14 provides examples of A-weighted noise levels from common sounds. In general, human sound perception is such that a change in sound level of 3 dB is barely noticeable, a change of 5 dB is clearly noticeable, and a change of 10 dB is perceived as doubling or halving the sound level.

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Table 3-14. Typical Sound Levels in the Environment and Industry Common Outdoor Activities Noise Level (dBA) Common Indoor Activities 110 Rock band Jet flyover at 300 meters (1,000 feet) 100 Gas lawn mower at 1 meter (3 feet) 90 Diesel truck at 15 meters (50 feet), at 80 kilometers per hour (50 mph) 80 Food blender at 1 meter (3 feet) Garbage disposal at 1 meter (3 feet) Noisy urban area, daytime gas lawn mower at 30 meters (100 feet) 70 Vacuum cleaner at 3 meters (10 feet) Commercial area Heavy traffic at 90 meters (300 feet) 60 Normal speech at 1 meter (3 feet) Quiet urban daytime 50 Large business office Dishwasher, next room Quiet urban nighttime 40 Theater, large conference room (background) Quiet suburban nighttime 30 Library Quiet rural night time 20 Bedroom at night, concert hall (background) 10 Broadcast/recording studio Lowest threshold of human hearing 0 Lowest threshold of human hearing Source: Caltrans 2013. Note: dBA = A-weighted decibel. Leq is a sound energy level averaged over a specified period (typically no less than 15 minutes for environmental studies). Leq is a single numerical value that represents the amount of variable sound energy received by a receptor during a time interval. For example, a 1-hour Leq measurement would represent the average amount of energy contained in all the noise that occurred in that hour. Leq is an effective noise descriptor because of its ability to assess the total time-varying effects of noise on sensitive receptors. Unlike the Leq metrics, Ldn and CNEL metrics always represent 24-hour periods, usually on an annualized basis. Ldn and CNEL also differ from Leq because they apply a time-weighted factor designed to emphasize noise events that dn and CNEL penalize noise that occurs during certain sensitive periods. In the case of CNEL, noise occurring during the daytime (7:00 a.m.7:00 p.m.) receives no penalty. Noise during the evening (7:00 p.m.10:00 p.m.) is penalized by adding 5 dB, while nighttime (10:00 p.m.7:00 a.m.) noise is penalized by adding 10 dB. Ldn differs from CNEL in that the daytime period is defined as 7:00 a.m.10:00 p.m., thus eliminating the evening period. Ldn and CNEL are the predominant criteria used to measure roadway noise affecting residential receptors. These two metrics generally differ from one another by no more than 0.5 dB to 1 dB and, as such, are often treated as equivalent to one another. Vibration of displacement, velocity, or acceleration. Vibration can be a serious concern, causing buildings to shake and rumbling sounds to be heard. In contrast to noise, vibration is not a common environmental problem. It is unusual

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for vibration from sources such as buses and trucks to be perceptible, even in locations close to major roads. Some common sources of vibration are trains, buses on rough roads, and construction activities, such as blasting, piledriving, and heavy earthmoving equipment. Several different methods are used to quantify vibration. Peak particle velocity (PPV) is defined as the maximum instantaneous peak of the vibration signal. PPV is most frequently used to describe vibration impacts to buildings and is usually measured in inches per second (ips). The root mean square amplitude is most frequently used to describe the effect of vibration on the human body and is defined as the average of the squared amplitude of the signal. Decibel notation is commonly used to measure root mean square. The decibel notation acts to compress the range of numbers required to describe vibration. High levels of vibration may cause physical personal injury or damage to buildings. However, vibration levels rarely affect human health. Instead, most people consider vibration to be an annoyance that can affect concentration or disturb sleep. In addition, high levels of vibration can damage fragile buildings or interfere with equipment that is highly sensitive to vibration (e.g., electron microscopes). Most perceptible indoor vibration is caused by sources within buildings, such as operation of mechanical equipment, movement of people, or slamming of doors. Typical outdoor sources of perceptible vibration are construction equipment, steel-wheeled trains, and traffic on rough roads. If the roadway is smooth, the vibration from traffic is rarely perceptible. Sensitive Receptors Noise- and vibration-sensitive land uses are locations where people reside or where the presence of unwanted hospitals, guest lodging, churches, and some passive recreation areas would typically be considered noise and vibration sensitive and may warrant unique measures for protection from intruding noise (City of Thousand Oaks 2000). Sensitive receptors in the vicinity of the project site consist of residential land uses (single-family and multifamily residences to the south), approximately 1,700 feet or more away. These sensitive receptors represent the nearest sensitive land uses with the potential to be impacted by construction of the proposed project. Other noise-sensitive receptors are located farther away from the project site and would be less affected by on-site noise. Existing Noise Conditions Noise level measurements were conducted in the vicinity of the project site on January 20, 2023, to quantify and help characterize the existing outdoor ambient sound environment. Table 3-15 provides the locations, dates, and times the noise measurements were taken. The noise measurements were taken using a SoftdB Piccolo sound level meter equipped with a 0.5-inch, pre-polarized condenser microphone with pre-amplifier. The sound level meter meets the current American National Standards Institute standard for a Type 2 (General Grade) sound level meter. The accuracy of the sound level meter was verified using a field calibrator before and after the measurements, and the measurements were conducted with the microphone positioned approximately 5 feet above the ground. Table 3-15. Measured Noise Levels Receptors Location Date Time Leq (dBA) Lmax (dBA) ST1 South of project site adjacent to residence at 24 Rancho Conejo Boulevard 1/20/2023 11:30 a.m.11:51 a.m. 64.3 73.7

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Table 3-15. Measured Noise Levels Receptors Location Date Time Leq (dBA) Lmax (dBA) ST2 North of project site, along Hill Canyon Fire Road 1/20/2023 10:44 a.m.11:59 a.m. 54.7 64.4 Source: Appendix D. Notes: Leq = equivalent continuous sound level (time-averaged sound level); dBA = A-weighted decibels; Lmax = maximum sound level during the measurement interval. Short-term noise measurement at two locations (ST1 and ST2) were conducted in the vicinity of the project site, as shown in Figure 10, Noise Measurement Locations. The measured energy-averaged (Leq) and maximum (Lmax) noise levels are provided in Table 3-15. The field noise measurement data sheets are provided in Appendix D, Noise Modeling Results. The primary noise sources at the sites identified in Table 3-15 consisted of traffic on local and distant roadways; secondary noise sources included distant aircraft noise and bird song. As shown in Table 3-15, the measured sound levels ranged from approximately 55 dBA Leq at ST2 to approximately 64 dBA Leq at ST2. Applicable Noise Regulations and Standards Federal There are no federal noise regulations applicable to the project. However, various federal agencies have established rules and guidelines addressing noise and vibration. For example, in its Transit Noise and Vibration Impact Assessment Manual (FTA 2018), the Federal Transit Administration (FTA) offers guidance on the estimation of construction noise levels from a construction project site. It also provides suggested thresholds that include no more than 80 dBA Leq (over an 8-hour daytime period) as received at a residential land use. Since the City does not provide a quantified construction noise limit, this analysis adopts the 80 dBA Leq8h FTA guidance for quantitative construction noise impact assessment. With respect to vibration, the same abovementioned FTA manual provides guidance for the assessment of vibration impacts on people (i.e., potential annoyance), building damage risk, and disruption of vibration-sensitive processes. Vibration impact criteria suggested by the FTA vary both with the frequency of vibration event occurrence and the sensitivity of the building or process that may be exposed to groundborne vibration. By way of example, a modern commercial building constructed from reinforced concrete or steel would have a vibration impact threshold of 0.5 ips PPV, while a non-engineered timber or masonry structure more akin to a typical single-family or multifamily residence may have a more stringent 0.2 ips PPV vibration impact criteria against which project-attributed vibration due to construction could be assessed for the nearest such receptors in the surrounding community. State Government Code Section 65302(g) California Government Code Section 65302(g) requires the preparation of a Noise Element in a community general plan, which shall identify and appraise the noise problems for the community. The Noise Element shall recognize the guidelines adopted by the Office of Noise Control in the State Department of Health Services and shall quantify, to the extent practicable, current and projected noise levels for major noise sources such as highways and freeways, primary arterials and major local streets, rail lines, airports, and industrial plants.

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California General Plan Guidelines provides guidance for the acceptability of specific land use types within areas of specific noise exposure. OPR guidelines are advisory in nature. Local jurisdictions, including the City, have the responsibility to set specific noise standards based on local conditions (OPR 2017). Local City of Thousand Oaks General Plan Noise Element The project site is located within the City, as are the existing residences and other noise-sensitive land uses in the surrounding area. The noise criteria identified in the Noise Element of the Thousand Oaks General Plan are guidelines to evaluate the land use compatibility of outdoor environmental noise levels. The land use compatibility guidelines indicate that low-density and multifamily residential land uses are considered normally acceptable with noise levels below 60 dBA CNEL and conditionally acceptable with noise levels below 65 dBA CNEL (City of Thousand Oaks 2000). Furthermore, the Noise Element of the Thousand Oaks General Plan, Chapter 4.6, Noise Considerations in Environmental Impact Reports and Negative Declarations, Section 4.6.1, identifies standards for operational noise in which a significant impact would occur at receiving sensitive land uses (i.e., residences to the south and southeast of the project site) (City of Thousand Oaks 2000): Project-related increase of greater than 1.0 dBA at residences in areas where annual average noise level at General Plan buildout would be between 55 and 60 dBA CNEL Project-related increase of greater than 0.5 dBA at residences in areas where the annual average noise level at General Plan buildout would be greater than 60 dBA CNEL of the Noise Element, the project-attributed increase to the outdoor ambient sound environment (expressed as CNEL) encompasses both changes to local surface transportation noise (roadway noise) and on-site operation of stationary sources (e.g., rooftop heating, ventilation, air conditioning systems, standby generators, etc.). City of Thousand Oaks Municipal Code The Noise Ordinance presented in Title 5, Chapter 21, Noise, does not provide quantitative standards for noise regulation. However, Section 8-the hours of 7:00 a.m. and 7:00 p.m., Monday through Saturday, unless permission is specifically granted by the Public Works Department for work outside these hours (i.e., 7:00 p.m. to 7:00 a.m. Monday through Saturday and anytime on Sundays).

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a) Would the project result in generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? Short-Term Construction Noise Less-than-Significant Impact. Noise generated by project construction equipment would include a combination of heavy equipment including dozers, front end loaders, backhoes, and air compressors that, when combined, can reach relatively high levels. The number and mix of construction equipment would likely vary during the following phases: demolition, site preparation, grading, basin construction, storm drain/outlet pipe construction, and paving. No blasting or piledriving is anticipated as part of the proposed project. Using specific construction equipment assumptions similar to those as used for the air quality analysis (Section 3.3), a noise analysis was performed using a model emulating the Roadway Construction Noise Model (RCNM) that was developed by the Federal Highway Administration (FHWA 2008). Input variables for the RCNM consist of the receiver/land use types, the equipment type (i.e., backhoe, crane, truck, etc.), the number of equipment pieces, the duty cycle for each piece of equipment (i.e., percentage of each time period the equipment typically is in operation and operating at full load or power level), and the distance between the construction noise source and the sensitive receiver. The RCNM has default duty-cycle values for the various pieces of equipment, which were derived from an extensive study of typical construction activity patterns. Those default duty-cycle values were adopted for this noise analysis. Table 3-16 provides a summary of the predicted construction noise exposure levels by each phase at the nearest noise-sensitive receptor locations. The input and output data are provided in Appendix D. Noise-sensitive land uses in the vicinity of the project site include existing single-family and multifamily residences to the south. Consequently, project construction noise exposure levels at other receivers farther away from the site would be less, due primarily to natural distance-dependent attenuation factors such as geometric divergence, air absorption, ground surface absorption, and potential path-occluding structures and topography. Table 3-16. Construction Noise Model Results Summary Land Use Off-site Receptor Location Distance from Construction Activity to Noise Receptor (feet) Estimated Construction Noise Levels (dBA Leq8h) Demolition Site Preparation Grading Basin Construction Storm Drain/ Outlet Pipe Construction Paving Residential South of the project Nearest Construction Activity/ Receiver Distance (1,700 feet) 54 51 53 54 52 48 Source: Appendix D. Notes: dBA = A-weighted decibel; Leq = equivalent continuous sound level.

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As shown in Table 3-16, typical construction noise levels at the nearest noise-sensitive land uses (residences to the south) are estimated to range from approximately 48 dBA Leq during the paving phase to approximately 54 dBA Leq during the demolition and basin construction phases. Table 3-16 and Appendix D worksheets show construction noise level predictions at distances between the noise-sensitive receptor position and the anticipated nearest boundary associated with a construction phase. These noise levels would be well below the FTA-suggested threshold of 80 dBA Leq8h for construction noise. As discussed previously, City Municipal Code Section 8-11.01 does not permit construction noise that would create a noise disturbance between the hours of 7:00 p.m. and 7:00 a.m. or on Sunday. Construction during these hours is not expected to occur for the proposed project. During allowed construction hours, the eq8h. Therefore, noise from project construction would be less than significant. There are no cumulative projects with overlapping construction schedules within the vicinity of the project site. Although the predicted impact due to construction noise is less than significant, good construction practice (or as required by City regulations, policies, or expectations) would include providing off-site residences advance notice of expected construction periods. Long-Term Operational Noise No Impact. During operation, the proposed project would convey existing storm flows and would not include any pumps, motors, or other noise-producing mechanical equipment. As such, there would be no impact related to a permanent increase in ambient noise levels. b) Would the project result in generation of excessive groundborne vibration or groundborne noise levels? Less-than-Significant Impact. The main concern associated with groundborne vibration is annoyance; however, in extreme cases, vibration can cause damage to buildings, particularly those that are old or otherwise fragile. Some common sources of groundborne vibration are trains and construction activities such as blasting, piledriving, and heavy earthmoving equipment. No blasting or piledriving is anticipated as part of the proposed project; thus, the primary source of groundborne vibration from the proposed project is heavy earthmoving equipment during construction activity. Groundborne vibration information related to construction/heavy equipment activities has been collected by Caltrans. Information from Caltrans indicates that continuous/intermittent vibrations (such as from construction activity) with approximately 0.1 ips (Caltrans 2020). The heavier pieces of construction equipment, such as large bulldozers or hoe rams, would register up to approximately 0.089 ips PPV at a distance of 25 feet per FTA guidance (FTA 2018). Groundborne vibration is typically attenuated over relatively short distances. At the nearest existing noise/vibration-sensitive use distance to the nearest construction boundary (approximately 1,750 feet) and with the anticipated construction equipment, the vibration level would be approximately 0.0002 ips PPV and therefore would be well below the Caltrans guidance standard of 0.1 ips PPV. There would not be significant groundborne vibration impacts associated with annoyance. Construction vibration from construction equipment (an intermittent or continuous type of vibration) as a result of the proposed project would not result in structural building damage, which typically occurs at vibration levels of 0.2 ips PPV or greater for buildings of non-engineered timber and masonry buildings. Thus, impacts related to groundborne vibration would be less than significant.

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During operation, the proposed project would not include any pumps, motors, or other mechanical equipment that would produce vibrations. As such, there would be no impact related to groundborne vibration. c) For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? No Impact. No private airstrips exist in the vicinity of the project site. The project site is not located within 2 miles of a public airport or public use airport, nor is it located within the boundaries of any airport land use plans. The nearest airport is the Camarillo Airport, which is located approximately 8.3 miles east of the project site. As such, the proposed project would not result in excessive noise for people residing or working in the project area. There would be no impact. 3.14 Population and Housing Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XIV. POPULATION AND HOUSING Would the project: a) Induce substantial unplanned population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)? b) Displace substantial numbers of existing people or housing, necessitating the construction of replacement housing elsewhere? a) Would the project induce substantial unplanned population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)? No Impact. The proposed project involves the implementation of drainage infrastructure improvements at an existing wastewater treatment facility. The project does not involve the development of new housing or infrastructure that may result in indirect population growth. Additionally, the construction of the project would not require a substantial number of construction workers. The construction demand created by the project is anticipated to be fulfilled by the existing local labor force. The project would not result in an increase in operational employees at the wastewater treatment facility. As such, there would be no impact.

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b) Would the project displace substantial numbers of existing people or housing, necessitating the construction of replacement housing elsewhere? No Impact. As discussed above, the proposed project involves the implementation of drainage infrastructure improvements at an existing wastewater treatment facility. The project would not displace people or housing, and there would be no impact. 3.15 Public Services Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XV. PUBLIC SERVICES a) Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times, or other performance objectives for any of the public services: Fire protection? Police protection? Schools? Parks? Other public facilities? a) Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times, or other performance objectives for any of the public services: Fire protection? No Impact. The project site is located in the City, which receives fire protection services, medical aid, rescue, hazardous materials response, and a variety of other services from the Ventura County Fire Department (VCFD). The nearest fire station to the site is Ventura Fire Station 30, which is located approximately 2.75 miles southeast of the project site at 325 West Hillcrest Drive. The need for new or altered fire station facilities is usually associated with substantial population growth such that existing facilities cannot meet the increased demand for fire protection services. As mentioned in Section 3.14, Population and Housing, the proposed project would not require a substantial number of construction workers, nor would it result in an increase of operational employees at the site. The pactivities, however, may temporarily increase the likelihood of emergency calls coming from the site to VCFD. This increase would be nominal and would be adequately served by existing fire resources. Once operational, the project site would continue to operate as a wastewater treatment facility and would not see an increase in the demand for VCFD services when compared to existing conditions. Therefore, the project would not facilitate the need for new or physically altered fire protection facilities and there would be no impact.

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Police protection? No Impact. The project site receives police protection services from the Thousand Oaks Police Department, located at 2101 East Olsen Road approximately 5.5 miles northeast of the site. As previously discussed, the project would not result in population growth in the area, nor would it result in an increase of operational employees at the Treatment Plant. The project would continue to operate as a wastewater treatment facility after project implementation and would not see an increase in the demand for police protection services when compared to existing conditions. Therefore, the project would not facilitate the need for new or physically altered police protection facilities, and there would be no impact. Schools? No Impact. The proposed project would include the development of drainage infrastructure improvements at an existing wastewater treatment facility and would not induce population growth. As such, the proposed project would place no demand on local schools and would not facilitate the need for new or physically altered schools. There would be no impact. Parks? No Impact. The proposed project would include the development of drainage infrastructure improvements at an existing wastewater treatment facility and would not induce population growth. As such, the proposed project would place no demand on parks near the project site. Therefore, it would not facilitate the need for new or physically altered parks and there would be no impact. Other public facilities? No Impact. The proposed project would include the development of drainage infrastructure improvements at an existing wastewater treatment facility and would not induce population growth. As such, the proposed project would place no demand on libraries or other public facilities near the project site. Therefore, it would not facilitate the need for new or physically altered public facilities and there would be no impact. 3.16 Recreation Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XVI. RECREATION a) Would the project increase the use of existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated?

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Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact b) Does the project include recreational facilities or require the construction or expansion of recreational facilities which might have an adverse physical effect on the environment? a) Would the project increase the use of existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated? No Impact. The project would involve the development of drainage infrastructure improvements at an existing wastewater treatment facility. It would not include population growth and as such, would have no impact on the use of parks or recreational facilities. b) Does the project include recreational facilities or require the construction or expansion of recreational facilities which might have an adverse physical effect on the environment? No Impact. The project would not involve the development of recreational facilities. Therefore, the proposed project would have no impact related to adverse physical effects on the environment from the construction or expansion of such facilities. 3.17 Transportation Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XVII. TRANSPORTATION Would the project: a) Conflict with a program, plan, ordinance, or policy addressing the circulation system, including transit, roadway, bicycle, and pedestrian facilities? b) Conflict or be inconsistent with CEQA Guidelines section 15064.3, subdivision (b)? c) Substantially increase hazards due to a geometric design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment)? d) Result in inadequate emergency access?

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a) Would the project conflict with a program, plan, ordinance, or policy addressing the circulation system, including transit, roadway, bicycle, and pedestrian facilities? No Impact. The proposed project would involve the development of drainage improvements on a wastewater treatment facility that is not accessible to the public and contains no public rights-of-way. Therefore, the project would not impact transit, roadway, bicycle, or pedestrian facilities. Therefore, the project would not conflict with a program, plan, ordinance, or policy addressing the circulation system, and there would be no impact. b) Would the project conflict or be inconsistent with CEQA Guidelines section 15064.3, subdivision (b)? Less-than-Significant Impact. CEQA Guidelines Section 15064.3(b) focuses on VMT for determining the significance of transportation impacts. It is further divided into four subdivisions: (1) land use projects, (2) transportation projects, (3) qualitative analysis, and (4) methodology. The updated CEQA Guidelines -road passenger vehicles, specifically cars and light trucks. The OPR has clarified in its Technical Advisory (OPR 2018) that heavy-duty truck VMT is not required to be included in vant considerations may include the effects of a project on transit and non-motorized traveled. The City has established an interim Citywide policy using VMT as the metric to measure transportation impacts from proposed development projects and determine thresholds of significance on a case-by-case basis pursuant to Section 15064(b)(2). Hence this section uses VMT as the basis for evaluating transportation impacts of the proposed project under CEQA. However, it should be noted that the guidelines and thresholds apply to land use and transportation projects that are subject to CEQA analysis. The proposed project is not a land use or transportation project, and therefore neither Section 15064.3(b)(1) nor Section 15064.3(b)(2) of the CEQA Guidelines applies. Instead, the proposed project would be categorized under Section 15064.3(b)(3) qualitative analysis. The updated CEQA Guidelines do not establish a significance threshold; however, they recommend a threshold of significance for land use development (residential, office, and other land uses) and transportation projects. It should be noted that there is no significance threshold for construction or maintenance projects. The project would involve construction that would generate temporary construction-related traffic for approximately 6 months and no operational traffic. The highest number of construction workers is estimated at 16 and this is during the storm drain/outlet pipe construction phase. Every other phase will have 10 or fewer workers. The highest number of trucks will be 8 during the demolition phase. Measures to reduce the VMT generated by workers and trucks are limited, and there are no thresholds or significance criteria for temporary, construction-related VMT. The project construction would be generally consistent with common construction activities in terms of the temporary nature of activities, trip generation characteristics, and the types of vehicles and equipment required. Even though worker and haul trips would generate VMT, once construction is completed, the construction-related traffic would cease and would return to pre-construction conditions. The increase in VMT associated with the projects construction is expected to be temporary and would therefore have a less-than-significant VMT impact.

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The City considers any project that generates less than 100 p.m. peak hours trips based on the Institute of Transportation Engineers Trip Generation Manual (10th Edition; ITE 2017) to be screened out of conducting a detailed VMT analysis. During operation, the proposed project would consist of drainage infrastructure improvements at an existing wastewater treatment facility and would not result in an increase of employees at the Treatment Plant or generate new trips. Therefore, the proposed project would not conflict or be inconsistent with CEQA Guidelines Sections 15064.3(b)(1) and 15064.3(b)(3), and there would be no impact. c) Would the project substantially increase hazards due to a geometric design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment)? No Impact. The project involves the development of drainage improvements on a site that is not accessible to the public and contains no adjacent public rights-of-way. The proposed project would not result in any circulation changes. Additionally, the project site is currently an operational wastewater treatment facility and would continue to operate as such under project conditions. Therefore, the project would not substantially increase hazards due to a geometric design features or incompatible uses, and there would be no impact. d) Would the project result in inadequate emergency access? No Impact. As previously discussed, the proposed project would not result in changes to circulation on or within the vicinity of the site. The project would not have an effect on access to and from the site. The pThousand Oaks 2020). Therefore, there would be no impact to emergency access. 3.18 Tribal Cultural Resources Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XVIII. TRIBAL CULTURAL RESOURCES Would the project cause a substantial adverse change in the significance of a tribal cultural resource, defined in Public Resources Code section 21074 as either a site, feature, place, cultural landscape that is geographically defined in terms of the size and scope of the landscape, sacred place, or object with cultural value to a California Native American tribe, and that is: a) Listed or eligible for listing in the California Register of Historical Resources, or in a local register of historical resources as defined in Public Resources Code section 5020.1(k), or

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Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact b) A resource determined by the lead agency, in its discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of Public Resources Code Section 5024.1? In applying the criteria set forth in subdivision (c) of Public Resources Code Section 5024.1, the lead agency shall consider the significance of the resource to a California Native American tribe. The evaluation of potential impacts to Tribal Cultural Resources is based on the findings resulting from the Phase I cultural resources assessment conducted in 2022 (Appendix C1) and the findings pursuant to AB 52. Background research conducted to inform this analysis included an NAHC SLF search, ethnographic research, archival research, and CHRIS database records search, all of which are briefly summarized in this section and more fully summarized in Section 3.5, Cultural Resources, and in the Phase I cultural resources assessment (Appendix C1). To date, no Tribal Cultural Resource has been identified. Existing SettingEthnohistoric The history of the Native American communities prior to the mid-1700s has largely been reconstructed through later mission-period and early ethnographic accounts. The first records of the Native American inhabitants of the region come predominantly from European colonizers. These short, and generally peripheral, accounts were predominantly prepared with the direct or indirect purpose of furthering colonial and economic aims and should not be viewed as unbiased descriptions of Native American groups. Though the establishment of the missions in the region resulted in more documentation of Native American communities, these groups did not become the focus of formal and in-depth ethnographic study until the early twentieth century (Bean and Shipek 1978; Boscana 1846; Geiger and Meighan 1976; Harrington 1934; Laylander 2000; Sparkman 1908; White 1963). The principal intent of these early researchers was to record the precontact, culturally specific practices, ideologies, and languages that had survived the destabilizing effects of missionization and colonialism. Though many informants for early ethnographies provided first-hand knowledge about native life before European contact, the majority of the informants were born many years post-contact and were therefore relying on secondary or tertiary sources on indigenous lifeways, experiences, and culture (Heizer and Nissen 1973). As Robert F. Heizer (1978) stated, this is an important issue to note when examining these ethnographies, since considerable culture change had undoubtedly occurred by 1850 among the Native American survivors of California. Based on ethnographic information, it is believed that at least 88 different languages were spoken from Baja California Sur to the California/Oregon border at the time of Spanish contact (Johnson and Lorenz 2006). The distribution of recorded Native American languages has been dispersed as a geographic mosaic across California through six primary language families (Golla 2007). The project site is located within territory attributed to the

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Ventureño Chumash, less than 6 miles west of currently understood Fernandeño territory (Golla 2011) and approximately 30 miles east of currently understood Barbareño Chumash territory (Golla 2011). The position of the project site likely led to increased interaction between the two groups, conceivably realized through trade, intermarriage, or other means (Golla 2011). It is important to acknowledge that territorial borders of the local Native American groups are currently understood through limited information and that it is likely they were implicitly utilized in prehistoric times, employing different social constructual lenses than those that exist today. A brief ethnographic summary of the Ventureño Chumash is provided below. Ventureño Chumash The project site was occupied by speakers of Ventureño Chumash, a variety of Central Chumash spoken within the eastern third of the Central Chumash territory encompassing the area from Santa Maria in the north, Malibu in the south, the Pacific Ocean to the west, and Kern County to the east. The Central Chumash language includes three other linguistic-geographic entitiesPurisemeño, Inezeño, and Barbareñoand is itself a subset of the larger Chumash language group, which contains two other linguistic-geographic entities, Obispeño and Island Chumash. Chumash was formerly considered a Hokan language, but is now thought of as a distinct language group (Golla 2011). Central Chumash linguistic-geographic entities are a result of the mission-era restructuring of the dialect continuum within the region and all share a phonological and grammatical system (Golla 2011). Ventureño Chumash includes several dialectic entities, including Venutura, Mugu, Malibu, Matilija, Castac, Interior Venturño, Vayetano, and El Conejo. The language variety associated with the project site was El Conejo (Golla 2011). The area inhabited by the Ventureño Chumash extended from the west of modern-day City of Ventura throughout the Oxnard Plains, the Santa Monica Mountains, and the Conejo Valley, and south along the coast to Point Dume. The neighboring Native American groups were the Barbareño Chumash to the west, the Tongva to the east, and the Tatavium to the north (Golla 2007; Moratto 1984). The diverse ecological environment and plentiful resources in the area put the Ventureño Chumash in a position to facilitate complex trade networks with island Chumash, as well as their Barbareño, Tongva, and Tatavium neighbors (Grant 1978). The earliest European visits to the Chumash region began with the expeditions of Cabrillo, Vizcaíno, and other naval explorers to the Southern California coast in the 1500s. The first land expedition through the study area occurred in AD 1769 when Gaspar de Portolá led an overland expedition from the newly established settlement at San Diego to San Francisco Bay. Ventureño place-names were recorded very early on due to Spanish exploration throughout Alta California. The Spaniards first arrived in the study -day Ventura. In 1762, members of the Portolá expedition traveled through the study area and noted that their residential structures resembled those of the nearby Tongva and were rectangular and covered with mats made of natural plant materials. One difference noted by the explorer and his companions was the multitude of artifact types existent along the coast. The rectangular residential structural form was later determined to be associated with small, inlanof 30 large residential structures and 15 canoe-like watercraft being utilized by the inhabitants where Mission San Buenaventura would eventually be established in 1783 (Heizer 1978). Large, permanent Chumash villages, such emispherical dwellings covered by grass or tule mats arranged in close proximity through the top hole where smoke could also exit. Residences were usually very large (15 meters in diameter) and

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The villages also contained storehouses, one or more subterranean sweat lodges, and a semi-circular dance ground and associated sacred ceremonial enclosure, with a nearby game field surrounded by low walls (McCall and Perry 1986). Satellite gathering or processing areas include earth ovens used to roast yucca and other foods, rock shelters, quarries, and bedrock mortars for processing acorns and similar plant resources (King 1994). Each Chumash village had a formal cemetery, generally separate from the village proper. Ethnographic records indicate that cemeteries were marked by tall painted poles and frequently had an entrance area where ceremonies were performed. Within the cemetery, stone, wood, or bone markers identified burial sites. Chumash subsistence varied between coastal and inland resources, but like many indigenous Californian groups, the acorn was a dietary staple, especially for Chumash peoples residing inland without immediate access to marine resources. Acorns were harvested in the autumn and stored in the villages where they were ground to a meal, leached, and then cooked daily. In addition to acornsmainly from the coast live oakother nuts, such as pine nuts and walnuts, were collected. Chumash diet also included cattail roots, fruits and pads from Opuntia cactus, and bulbs and tubers of plants such as amole (Miller 1988). Yucca stalks were harvested and roasted, and the buds and flowers were also gathered. Staples included small hard seeds of several annual and perennial plants such as grass, chia and other sages, and buckwheat. Seasonal resources included berries (blackberry, elderberry, grape, madrone, laurel, wild cherry), mushrooms, and cress. The Ventureño region was well sources such as rivers, creeks, and tributaries and along the coast. King (1969) located 41 settlements within the Ventureño territory and estimated that the population was between 2,500 and 4,200 in 1770. Many modern towns took their names from Ventureño Chumash place-names, such as ma(Simi), and muwu (Mugu) (Heizer 1978). Archaeological investigations in the area indicate that coastal settlements have much higher quantity of material culture and that there is a direct relationship between proximity to the coast and amount of material culture within a site. Additionally, excavations have indicated that inland sites have tools of a generally lower quality than those produced on the coast (Heizer 1978). As mentioned previously, the protohistoric culture of the Chumash was terminated by the arrival of a Spanish expedition led by Gaspar de Portolá in 1769. Chumash culture changed dramatically with the establishment of the Missions of San Buenaventura and San Fernando Rey de España. The San Buenaventura Mission was established in 1782 located near the sizable village of Mitsquanaqa'n, which is estimated to have had approximately 500 inhabitants. With the secularization of mission lands after 1834, traditional Chumash lands were distributed among grants to private owners. Only in the areas of Mission Santa Barbara and Mission San Fernando del Rey were several small ranchos granted to neophytes of these missions, providing a secure home and gardens for a few people. Most Chumash managed to maintain a presence in the study area into the early twentieth century as cowboys, farm hands, and town laborers. The Catholic Church provided some land near Mission Santa Ynez for ex-neophytes. This land near Mission Santa Ynez was eventually deeded to the U.S. government in 1901 as a 127-acre reservation. This is the sole Chumash reservation, with a recent enrollment of 249 residents and 97 homes (SYBCI 2009). Since the 1970s, Chumash descendants living in the City of Santa Barbara and the rural areas of San Luis Obispo, Santa Barbara, and Ventura Counties have formed social and political organizations to aid in cultural revitalization, to protect sacred areas and archaeological sites, and to petition for federal recognition. Today, the Santa Ynez Band of Chumash Indians is the only federally recognized Chumash tribe.

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Regulatory Framework Assembly Bill 52 AB 52 of 2014 amended PRC Section 5097.94 and added PRC Sections 21073, 21074, 21080.3.1, 21080.3.2, 21082.3, 21083.09, 21084.2, and 21084.3. AB 52 established that Tribal Cultural Resources must be considered under CEQA and also provided for additional Native American consultation requirements for the lead agency. PRC Section 21074 describes a Tribal Cultural Resource as a site, feature, place, cultural landscape, sacred place, or object that is considered of cultural value to a California Native American Tribe. A Tribal Cultural Resource is either: On the CRHR or a local historic register Eligible for the CRHR or a local historic register A resource determined by the lead agency, in its discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of PRC Section 5024.1 AB 52 formalizes the lead agencytribal consultation process, requiring the lead agency to initiate consultation with California Native American groups that are traditionally and culturally affiliated with a project area, including tribes that may not be federally recognized. Lead agencies are required to begin consultation prior to the release of a negative declaration, MND, or EIR. Tribal Cultural Resources should be considered under CEQA. Section 6 of AB avoiding or substantially lessening potential significant impacts to a tribal cultural resource or alternatives that would avoid significant impacts to a tribal cultural consultation regarding project alternatives, mitigation measures, or significant effects to Tribal Cultural Resources, the consultation shall include those topics (PRC Section 21080.3.2[a]). The environmental document and the mitigation monitoring and reporting program (where applicable) shall include any mitigation measures that are adopted (PRC Section 21082.3[a]). Sacred Lands File Search A search of the NAHC SLF was conducted on December 6, 2022, to determine the presence of any reported Native American cultural resources within the project site as listed in the NAHC-maintained SLF (see Confidential Attachment C to Appendix C1). The NAHC SLF records search result was negative. The SLF maintained by the NAHC represents significance to Native Americans and known ancient graves and cemeteries of Native Americans on private and public NAHC 2021) provided by tribal entities and Native American representatives. For various reasons, tribal entities and Native American representatives do no not always report sacred lands or Tribal Cultural ResourceSLF is not necessarily a comprehensive list of known Tribal Cultural Resources and searches of the SLF must be considered in concert with other research and not used as a sole source of information regarding the presence of Tribal Cultural Resources. Additionally, results of the SLF provided relate to the general regional area within and surrounding the project site and do not necessarily equate to the existence of resources within the specific area occupied by the project site.

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Assembly Bill 52 Outreach/Consultation The project is subject to compliance with AB 52 (PRC Section 21074), which requires consideration of impacts to Tribal Cultural Resources as part of the CEQA process, and that the lead agency provide tribes who have requested notification with early notice of the proposed project and, if requested, consultation to inform the CEQA process with respect to Tribal Cultural Resources. No California Native American tribes have requested notification for ation letters pursuant to AB 52 were sent and no Tribal Cultural Resources were identified as a result of the AB 52 tribal outreach/consultation process. Would the project cause a substantial adverse change in the significance of a tribal cultural resource, defined in Public Resources Code section 21074 as either a site, feature, place, cultural landscape that is geographically defined in terms of the size and scope of the landscape, sacred place, or object with cultural value to a California Native American tribe, and that is: a) Listed or eligible for listing in the California Register of Historical Resources, or in a local register of historical resources as defined in Public Resources Code section 5020.1(k)? Less-than-Significant Impact. As described in Section 3.5 and in Appendix C1, a CHRIS records search, NAHC SLF search, and pedestrian survey were conducted for the project site. The SLF search was completed with negative results. The CHRIS records search identified eight cultural resources, including seven prehistoric archaeological resources and one historic archaeological resource, that have been previously recorded within 0.5 miles of the project site. However, no cultural resources listed or eligible for listing in the CRHR, or in a local register of historical resources as defined in PRC Section 5020.1(k), were identified within the project site as a result of either (1) several previous investigations or (2) the current investigation. Therefore, the project would not adversely affect Tribal Cultural Resources that are listed or eligible for listing in the State or local register. Impacts would be less than significant. b) A resource determined by the lead agency, in its discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of Public Resources Code Section 5024.1? In applying the criteria set forth in subdivision (c) of Public Resource Code Section 5024.1, the lead agency shall consider the significance of the resource to a California Native American tribe. No Impact. jurisdiction. As such, no notification letters pursuant to AB 52 were sent and no Tribal Cultural Resources were identified as a result of the AB 52 tribal outreach/consultation process. Therefore, the project would not adversely affect Tribal Cultural Resources determined by the lead agency, in its discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of PRC Section 5024.1. There would be no impact.

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3.19 Utilities and Service Systems Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XIX. UTILITIES AND SERVICE SYSTEMS Would the project: a) Require or result in the relocation or construction of new or expanded water, wastewater treatment or storm water drainage, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects? b) Have sufficient water supplies available to serve the project and reasonably foreseeable future development during normal, dry, and multiple dry years? c) Result in a determination by the wastewater treatment provider which serves or may serve the project that it has adequate existing commitments? d) Generate solid waste in excess of State or local standards, or in excess of the capacity of local infrastructure, or otherwise impair the attainment of solid waste reduction goals? e) Comply with federal, State, and local management and reduction statutes and regulations related to solid waste? a) Would the project require or result in the relocation or construction of new or expanded water, wastewater treatment or storm water drainage, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects? Less-than-Significant Impact. The project would result in the development of a new debris basin and storm drainage improvements at an existing stormwater treatment facility in order to prevent future flooding at the site. As such, the project involves the construction stormwater drainage facilities. The impacts of this development, however, are addressed throughout this IS/MND and are less than significant. The proposed project would not require or result in the relocation or construction of expanded water, wastewater treatment, electric power, natural gas, or telecommunications facilities. Therefore, impacts would be less than significant.

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b) Would the project have sufficient water supplies available to serve the project and reasonably foreseeable future development during normal, dry and multiple dry years? No Impact. Minimal use of water during construction of the project may be required for dust suppression. However, this demand would be nominal and temporary and would not significantly impact water supplies. The project proposed to develop stormwater drainage improvements at an existing stormwater treatment facility, which would not involve demand on water supplies during operation. As such, the project would not result in an increased need for water supplies. Therefore, there would be no impact. c) Would the project result in a determination by the wastewater treatment provider which serves or may No Impact. The proposed project would not result in an increased need for wastewater treatment services. Alternatively, the project proposed to develop drainage improvements at an existing stormwater treatment facility, which would assist the facility in managing existing flows. As such, there would be no impact. d) Would the project generate solid waste in excess of State or local standards, or in excess of the capacity of local infrastructure, or otherwise impair the attainment of solid waste reduction goals? No Impact. The proposed project would generate some waste during construction; however, the amount of waste generated would be limited due to the nature of the project and the lack of extensive demolition. Additionally, the project would be subject to the 2019 California Green Building Standards Code Construction Waste Management Requirements (No. 1639-NS) (City of Thousand Oaks 2021), which require recycling and/or salvage of a minimum 65% of the nonhazardous construction and demolition waste. As such, the amount of demolition and construction debris requiring disposal at a landfill would represent a tiny fraction of the permitted capacity of nearby landfills and would not significantly impact capacity. The proposed project would not generate solid waste during operation. The project would develop drainage improvements at a stormwater treatment facility. Therefore, the project would not generate solid waste in excess of State or local standards, or in excess of the capacity of local infrastructure, and there would be no impact. e) Would the project comply with federal, State, and local management and reduction statutes and regulations related to solid waste? No Impact. Except for a nominal amount of construction debris, the project would not result in the generation of solid waste. Waste generated during construction would comply with applicable statutes and regulations, as discussed under Threshold 3.19(d) above. Therefore, the project would not conflict with federal, State, or local management and reduction statutes and regulations related to solid waste and there would be no impact.

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3.20 Wildfire Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XX. WILDFIRE If located in or near State responsibility areas or lands classified as very high fire hazard severity zones, would the project:a) Substantially impair an adopted emergency response plan or emergency evacuation plan? b) Due to slope, prevailing winds, and other factors, exacerbate wildfire risks, and thereby expose project occupants to, pollutant concentrations from a wildfire or the uncontrolled spread of a wildfire? c) Require the installation or maintenance of associated infrastructure (such as roads, fuel breaks, emergency water sources, power lines or other utilities) that may exacerbate fire risk or that may result in temporary or ongoing impacts to the environment? d) Expose people or structures to significant risks, including downslope or downstream flooding or landslides, as a result of runoff, post-fire slope instability, or drainage changes? a) Would the project substantially impair an adopted emergency response plan or emergency evacuation plan? No Impact. As discussed in Section 3.9, Hazards and Hazardous Materials, the project site is located at an existing stormwater Treatment Plant. The plant is not accessible to the public. Therefore, construction would not require the closure of any public rights-of-way. Additionally, the project is not located in the vicinity of a designated evacuation route (City of Thousand Oaks 2014). As discussed in Section 3.15, the City would continue to provide an adequate level of emergency response service. Therefore, the project would not result in impairment of an adopted emergency response plan or an emergency evacuation plan, and there would be no impact. b) Due to slope, prevailing winds, and other factors, would the project exacerbate wildfire risks, and thereby expose project occupants to, pollutant concentrations from a wildfire or the uncontrolled spread of a wildfire? Less-than-Significant Impact with Mitigation Incorporated. The project site is located in a Very High Fire Hazard Severity Zone in a Local Responsibility Area (CAL FIRE 2022). The proposed project involves the construction of drainage improvements within an existing wastewater Treatment Plant and within an immediately adjacent undeveloped hilly area. Building materials used for the storm drain basin

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improvements would be non-flammable and the project does not entail the construction of habitable structures. Construction would involve the temporary deployment of construction personnel to the project site and the use of combustion engine-powered equipment that has the potential to produce sparks that could ignite a fire, the spread of which could have significant impacts on pollution concentrations and uncontrolled spread of wildfire. The incorporation of MM-FIRE-1 (Construction Fire Prevention Plan) would reduce the potential impacts. MM-FIRE-1 Construction Fire Prevention Plan. The City of Thousand Oaks shall prepare and implement a Construction Fire Prevention Plan (Plan) to ensure the safety of workers and the public during construction of the proposed project. The applicant must submit the Plan to the Ventura County Fire Department for review and approval prior to construction. The Plan shall include, but not be limited to, the following elements: Procedures for minimizing potential ignition, including vegetation clearing, parking requirements/restrictions, idling restrictions, smoking restrictions, proper use of gas-powered equipment, and hot work restrictions. Work restrictions during Red Flag Warnings and High to Extreme Fire Danger days. All internal combustion engines used at the proposed project site shall be equipped with spark arrestors. Spark arrestors shall be in good working order. and in other common areas. Equipment parking areas and small stationary engine sites shall be cleared of all flammable materials. Smoking shall be prohibited in all vegetated areas and within 50 feet of combustible materials storage and shall be limited to paved areas or areas cleared of all vegetation. During construction, fire extinguishers and fire-fighting equipment sufficient to extinguish small fires shall be available on site and all construction vehicles shall be equipped with a fire extinguisher. All construction workers visiting the project site shall receive training on fire prevention procedures, the proper use of fire-fighting equipment, and procedures to be followed in the event of a fire. Fires ignited on site shall be immediately reported to the Ventura County Fire Department. The engineering, procurement, and construction contract(s) for the proposed project shall provide reference to or clearly state the requirements of this mitigation measure. With the incorporation of MM-FIRE-1, impacts associated with pollutant concentrations from a wildfire and the uncontrolled spread of a wildfire during project construction would be reduced to less than significant with mitigation incorporated. During operation, the project would not result in increased on-site employees and would not involve the operation of any mechanical equipment with the potential to produce sparks. As such, impacts associated with pollutant concentrations from a wildfire or the uncontrolled spread of a wildfire during operations would be less than significant.

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c) Would the project require the installation or maintenance of associated infrastructure (such as roads, fuel breaks, emergency water sources, power lines, or other utilities) that may exacerbate fire risk or that may result in temporary or ongoing impacts to the environment? Less-than-Significant Impact with Mitigation Incorporated. The proposed project would involve the development of drainage improvements at an existing wastewater treatment facility and would not include installation or maintenance of roads, fuel breaks, emergency water sources, power lines, utilities, or other associated infrastructure. As discussed under Threshold 3.20(b) above, construction of the project would involve the use of combustion engine construction equipment that could temporarily exacerbate fire risk. However, adherence to MM-FIRE-1 during construction would reduce such impacts to less than significant. Also discussed under Threshold 3.20(b) above, operation of the project would not result in increased fire risk. All temporary or ongoing impacts to the environment have been addressed and mitigated throughout this MND. Therefore, impacts related to exacerbated fire risk during operation would be less than significant. d) Would the project expose people or structures to significant risks, including downslope or downstream flooding or landslides, as a result of runoff, post-fire slope instability, or drainage changes? Less-than-Significant Impact. There have been no known landslides on the project site; however, as discussed in Section 3.7, Geology and Soils, the project site is located in a landslide zone (CGS 2023). Additionally, landslides have occurred in the vicinity of the site (USGS 2022). However, the project would reduce flooding and improve drainage into an existing wastewater Treatment Plant and would not include elements that would increase the risk of landslide. Additionally, as discussed under Threshold 3.20(b), the project would not result in a significant increase in fire risk and as such would not contribute to a significant risk related to post-fire slope instability. The project would be constructed within and immediately adjacent to an existing water Treatment Plant that is located at the confluence of two watersheds and experiences flooding after large storm events that exceed the capacity of some drainage facilities for conveying off-site flows. The project would include highly localized drainage improvements that would allow the plant to better handle existing flows that occur after such storm events under existing conditions. As such, these drainage changes would reduce risks associated with flooding. Therefore, the project would not expose people or structures to significant risks as a result of runoff, post-fire slope instability, or drainage changes, and impacts would be less than significant.

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3.21 Mandatory Findings of Significance Potentially Significant Impact Less Than Significant Impact With Mitigation Incorporated Less Than Significant Impact No Impact XXI. MANDATORY FINDINGS OF SIGNIFICANCE a) Does the project have the potential to substantially degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, substantially reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? b) Does the project have impacts that are individually limited, but cumulatively means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects.) c) Does the project have environmental effects which will cause substantial adverse effects on human beings, either directly or indirectly? a) Does the project have the potential to substantially degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, substantially reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? Less-than-Significant Impact with Mitigation Incorporated. As discussed in Section 3.4, through compliance with MM-BIO-1 through MM-BIO-9, project impacts to biological resources would be less than significant. As discussed in Section 3.5, through compliance with MM-CUL-1 through MM-CUL-4, project impacts to cultural resources and Tribal Cultural Resources would be less than significant. As discussed in Section 3.7, through compliance with MM-GEO-1, impacts to paleontological resources would be less than significant. As discussed in Section 3.20, through compliance with MM-FIRE-1, project impacts related to wildfire would be less than significant. Therefore, with mitigation incorporated, the project would not degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal

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community, reduce the number or restrict the range of a rare or endangered plant or animal, or eliminate important examples of the major periods of California history or prehistory. Impacts would be less than significant with mitigation incorporated. b) the effects of past projects, the effects of other current projects, and the effects of probable future projects.) Less-than-Significant Impact with Mitigation Incorporated. When evaluating cumulative impacts, it is important to remain consistent with Section 15064(h) of the CEQA Guidelines, which states that an EIR indiveffects of an individual project are significant when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects. not cumulatively considerable through mitigation measures set forth in an MND or if the project will comply with the requirements in a previously approved plan or mitigation program that provides specific requirements that will avoid or substantially lessen the cumulative problem within the geographic area in which the project is located. The proposed project would potentially result in project-related impacts to biological resources, cultural resources, geology and soils, and wildfire that could be potentially significant without the incorporation of mitigation. Thus, when coupled with potential impacts related to the implementation of other related projects throughout the broader project area, the project would potentially result in cumulative-level impacts if these significant impacts were left unmitigated. biological resources, cultural resources, geology and soils, and wildfire would be reduced to less-than-significant levels and would not considerably contribute to cumulative impacts in the greater project region. In addition, any other nearby projects would presumably be bound by their applicable lead agency to (1) comply with all applicable federal, State, and local regulatory requirements; and (2) incorporate all feasible mitigation measures, consistent with CEQA, to further ensure that their potentially cumulative impacts would be reduced to less-than-significant levels. Although cumulative impacts are always possible, the proposed project, by incorporating all mitigation measures outlined herein, would reduce its contribution to any such cumulative impacts to less than cumulatively considerable. Therefore, the project would result in individually limited, but not cumulatively considerable, impacts that are less than significant with mitigation incorporated. c) Does the project have environmental effects which will cause substantial adverse effects on human beings, either directly or indirectly? Less-than-Significant Impact with Mitigation Incorporated. As evaluated throughout this IS/MND, with incorporation of the mitigation measures identified herein, all environmental impacts associated with the project would be less than significant. Thus, the project would not directly or indirectly cause substantial adverse effects on human beings. Impacts would be less than significant with mitigation incorporated.

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4 References and Preparers 4.1 References Cited 14 CCR 1500015387 and Appendices A through L. Guidelines for Implementation of the California Environmental Quality Act, as amended. Allen, P.A. 1978. An Historic Study of the Property Known As the M.G.M Ranch a Planned Community by Shapell Industries Inc. Prepared by Conejo Valley Historical Society. On file at the CHRIS South Central Coastal Information Center, California State University, Fullerton. Bean, L.J., and F.California, Robert F. Heizer (ed.), pp. 550-563, Handbook of North American Indians, Vol. 8, W.C. Sturtevant (general editor), Smithsonian Institution, Washington, D.C. Bonner, W. 1997. Cultural Resources Assessment of the Hill Canyon Regional Recreational Facility, Thousand Oaks, Ca. Prepared for City of Thousand Oaks. Prepared by W.H. Bonner and Associates. On file at the CHRIS South Central Coastal Information Center, California State University, Fullerton. Life in California, by Alfred Robinson, 227341. New York, New York: Wiley & Putnam. Brown, A.K. 2001. A description of distant roads: original journals of the first expedition into California, 1769-1770 by Juan Crespi. San Diego, California: San Diego State University. CAL FIRE. 2022. Fire Hazard Severity Zone (FHSZ) Viewer. Accessed December 19, 2022. https://egis.fire.ca.gov/FHSZ/. CalGEM (California Geologic Energy Management Division). 2022. Well Finder. Accessed December 2023. https://maps.conservation.ca.gov/doggr/wellfinder/#openModal. CAPCOA (California Air Pollution Control Officers Association). 2008. CEQA & Climate Change: Evaluating and Addressing Greenhouse Gas Emissions from Proposed Projects Subject to the California Environmental Quality Act. January 2008. CAPCOA. 2023. California Emissions Estimator Model (CalEEMod) Version 2022.1.1.7 https://www.caleemod.com/. Accessed March 2023. Caltrans (California Department of Transportation). 2010. CO Protocol. October. https://dot.ca.gov/-/media/dot-media/programs/environmental-analysis/documents/env/co-protocol-searchable-a11y.pdf. Accessed March 2023. Caltrans. 2013. Technical Noise Supplement to the Traffic Noise Analysis Protocol. September 2013.

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Caltrans. 2018. California State Scenic Highway System Map. Accessed December 2022. https://caltrans.maps.arcgis.com/apps/webappviewer/index.html?id= 465dfd3d807c46cc8e8057116f1aacaa. Caltrans. 2020. Transportation and Construction Vibration Guidance Manual. Division of Environmental Analysis, Environmental Engineering, Hazardous Waste, Air, Noise, Paleontology Office. Sacramento, California. April. California Public Resources Code, Section 2100021177. California Environmental Quality Act, as amended. Capron, M.E. 2017. City of Thousand Oaks, Hill Canyon Wastewater Treatment Plant (HCTP), Stormwater Permit Notice of Non-Applicability via No Discharge. Dated June 27, 2017. Water Board Date Processed: July 5, 2017. CARB (California Air Resources Board). 2005. Air Quality and Land Use Handbook: A Community Health Perspective. April 2005. http://www.aqmd.gov/docs/default-source/ceqa/handbook/california-air-resources-board-air-quality-and-land-use-handbook-a-community-health-perspective.pdf. CARB. 2017. Climate Change Scoping Plan. November. https://ww2.arb.ca.gov/sites/ default/files/classic/cc/scopingplan/scoping_plan_2017.pdf. Accessed May 2022. CARB. 2022a. Map of State and Federal Area Designations. https://ww2.arb.ca.gov/resources/documents/ maps-state-and-federal-area-designations. Accessed March 2023. CARB. 2022b. 2022 Scoping Plan For Achieving Carbon Neutrality. November 16, 2022. https://ww2.arb.ca.gov/our-work/programs/ab-32-climate-change-scoping-plan/2022-scoping- plan-documents. Accessed March 2023. CDFW (California Department of Fish and Wildlife). 2019. California Natural Community Conservation Plans. Updated April 2019. Accessed December 2022. https://nrm.dfg.ca.gov/FileHandler.ashx? DocumentID=68626&inline. CDFW. 2022aJuly 5. https://www.wildlife.ca.gov/Data/VegCAMP/Natural-Communities. CDFW. 2022b. Rarefind 5: Commercial version. Online database. California Natural Diversity Database. CDFW, Biogeographic Data Branch. Accessed March 2022. https://wildlife.ca.gov/Data/CNDDB/Maps-and-Data. CDFW. 2022c. Biogeographic Information and Observation System (BIOS). Layers: South Coast Missing Linkages (ds419) and Habitat Connectivity Ventura County (ds565). https://wildlife.ca.gov/Data/BIOS. CDFW. 2022d. April 2022. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=109406&inline=1. CDOC (California Department of Conservation). 2022. Well Finder. Accessed December 2022. https://maps.conservation.ca.gov/doggr/wellfinder/#openModal.

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DeVecchio, D.E., E.A. Keller, M. Fuchs, and L.A. Owen. 2012. Late Pleistocene structural evolution of the Camarillo fold belt: Implications for lateral fault growth and seismic hazard in Southern California. Dibblee, T.W., and H.E. Ehrenspeck (ed.). 1990. Geologic Map of the Camarillo and Newberry Park Quadrangles, Ventura County, California: Dibblee Geological Foundation, Dibblee Foundation Map DF-28, scale 1:24,000. DTSC (Department of Toxic Substances Control). 2022. List of Hazardous Waste and Substances sites. Accessed December 20, 2022. https://www.envirostor.dtsc.ca.gov/public/. eBird. 2022. eBird: An online database of bird distribution and abundance [web application]. eBird, Cornell Lab of Ornithology, Ithaca, New York. Available: http://www.ebird.org. FHWA. 2008. Roadway Construction Noise Model (RCNM), Software Version 1.1. U.S. Department of Transportation, Research and Innovative Technology Administration, John A. Volpe National Transportation Systems Center, Environmental Measurement and Modeling Division. Washington, D.C. December 8, 2008. FTA (Federal Transit Administration). 2018. Transit Noise and Vibration Impact Assessment Manual. FTA Report No. 123. September. Geiger, M., and C.W. Meighan. 1976. As the padres saw them: California Indian life and customs as reported by the Franciscan Missionaries 1813-1815. Santa Barbara: Santa Barbara Mission Archive LIbrary. California Prehistory: Colonization, Culture, and Complexity, edited by T.L. Jones and K.A. Klar, 7182. New York, New York: Altamira Press. Golla, V. 2011. California Indian languages. Berkeley: University of California Press. Grant, C. 1978. Eastern Coastal Chumash. In Handbook of North American Indians, edited by Robert F. Heizer, 509-519. Washington: Smithsonian Institution. Smithsonian Miscellaneous Collections 92(4). California, edited by R.F. Heizer, 16. Handbook of North American Indians, Vol. 8, edited by W.C. Sturtevant. Washington, D.C.: Smithsonian Institution. Heizer, R., and K.M. Nissen. 1973. The Human Sources of California Ethnography. Berkeley, California: University of California Archaeological Research Facility, Berkeley. ITE (Institute of Transportation Engineers). 2017. Trip Generation Manual. 10th Edition. Washington, D.C.: Institute of Transportation Engineers. Journal of California and Great Basin Anthropology 26:3364.

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-243): an investigation of social organization from -68. Los Angeles: University of California, Los Angeles. King, C.D. 1994. Native American Placenames in the Santa Monica Mountains National Recreation Area, Agoura Hills. Topanga Anthropological Consultants, California. Laylander, D. 2000. Early Ethnography of the Californias, 1533-1825. Salinas, California: Coyote Press Archives of California Prehistory. Maki, M.K. 1997. Phase 1 Archaeological Survey and Impact Assessment of Approximately 4 Linear Miles for the Unit W & F Interceptor Replacement Project Arroyo Conejo Thousand Oaks, Ventura County, California. Prepared for Conejo Archaeological Consultants. Prepared by Padre and Associates. On file at the CHRIS South Central Coastal Information Center, California State University, Fullerton. McCall, L., and R. Museum of the Nature History Education Center. Santa Barbara, California: John Daniel, Publisher. Miller, B.W. 1988. Chumash: A Picture of Their World. Los Osos, California: Sand River Press. Moratto, M.J. 1984. California Archaeology. Academic Press, Orlando, Florida. Moratto, M.J. 1984. California Archaeology. New York: Academic Press, Inc. Morton, D.M., and F.K. Miller. 2006. Geologic Map of the San Bernardino and Santa Ana 30-minute x 60-minute quadrangles, California, Geology and Description of Map Units, Version 1.0: U.S. Geological Survey, Open-File Report OF-2006-1217. 194 pp. NAHC (Native American Heritage Commission). 2021. About the Native American Heritage Commission. State of California Native American Heritage Commission, 2021, http://nahc.ca.gov/about/. Accessed April 22, 2021. NHMLA (Natural History Museum of Los Angeles County). 2023. Paleontological resources for the Hill Canyon Treatment Plant Stormwater Diversion Project (PN: 12767). Unpublished paleontological records search results letter. Dated: March 5, 2023. Appendix D, Noise Element Guidelines: Guidelines for the Preparation and Content of the Noise Element of the General Plan. OPR. 2018. Technial Advisory on Evaluating Tranportation Impacts in CEQA. Accessed December 2022. https://opr.ca.gov/ceqa/docs/20190122-743_Technical_Advisory.pdf. Rosen, M.D. 1977. Conejo Canyons Study. Prepared for Thousand Oaks Planning Department. On file at the CHRIS South Central Coastal Information Center, California State University, Fullerton. SC Wildlands (South Coast Wildlands). 2008. South Coast Missing Linkages: A Wildland Network for the South Coast Ecoregion. The South Coast Missing Linkages Project. http://www.scwildland.org/reports/ SCMLRegionalReport.pdf.

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SCAG (Southern California Association of Governments). 2020. The 20202045 Regional Transportation Plan/Sustainable Communities Strategy of the Southern California Association of Governments, Connect SoCal. Adopted September 3, 2020. https://scag.ca.gov/sites/main/files/file-attachments/ 0903fconnectsocal-plan_0.pdf?1606001176. Accessed March 2023. SCAQMD (South Coast Air Quality Management District). 2008. Draft Guidance Document Interim CEQA Greenhouse Gas (GHG) Significance Threshold. October 2008. September 28, 2010. Accessed November 2020. http://www.aqmd.gov/docs/default-source/ceqa/ handbook/greenhouse-gases-(ghg)-ceqa-significance-thresholds/year-2008-2009/ghg-meeting-15/ ghg-meeting-15-main-presentation.pdf?sfvrsn=2. SVP (Society of Vertebrate Paleontology). 2010. Standard Procedures for the Assessment and Mitigation of Adverse Impacts to Paleontological Resources. 11 p. Available; https://vertpaleo.org/wp-content/ uploads/2021/01/SVP_Impact_Mitigation_Guidelines-1.pdf. Sparkman, P. 1908. The Cultural of the Luiseño Indians. University of California Publications in American Archaeology and Ethnology 8:187234. Berkeley: University of California. SWRCB (State Water Resources Control Board). 2022a. List of Leaking Underground Storage Tank Sites. Accessed December 20, 2022. https://geotracker.waterboards.ca.gov/map/?myaddress= California&from=header&cqid=62521187664. SWRCB. 2022b. Hill Canyon Treatment Plan (T0611130305). Accessed December 20, 2022. https://geotracker.waterboards.ca.gov/profile_report.asp?global_id=T0611130305. SYBCI (Santa Ynez Band of Chumash Indians). 2009. Santa Ynez Band of Chumash Indianshttps://www.santaynezchumash.org/. Accessed September 2021. -content/ uploads/2022/11/2022-Default-Emission-Factors-Final.pdf. Accessed March 2023. USDA-NRCS (U.S. Department of Agriculture, Natural Resources Conservation Service). 2022a. Web Soil Survey. Accessed August 2022. https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm. USDA-https://www.nrcs.usda.gov/wps/portal/nrcs/ main/soils/survey/class/. USFWS (U.S. Fish and Wildlife Service). 2022a. Occurrence Data [GIS data]. Last accessed August 2022. USFWS. 2022b ecp/report/table/critical-habitat.html. USGS (U.S. Geological Survey). 2022. U.S. Landslide Inventory. Accessed December 19, 2022. https://usgs.maps. arcgis.com/apps/webappviewer/index.html?id=ae120962f459434b8c904b456c82669d.

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Ventura County. 2022. Habitat Connectivity and Wildlife Corridors Map. https://rma.maps.arcgis.com/apps/ webappviewer/index.html?id=92c5352af22a44a3a99dd41aa1b8d567. VCAPCD (Ventura County Air Pollution Control District). 2003. Ventura County Air Quality Assessment Guidelines. Accessed March 2023. http://www.vcapcd.org/pubs/Planning/VCAQGuidelines.pdf. -review.htm#What_about_greenhouse_gases_and_CEQA_ Accessed March 2023. VCAPCD. 2022. Final 2022 Ventura County Air Quality Management Plan. December 13. Accessed March 2023. http://www.vcapcd.org/pubs/Planning/AQMP/2022/Final-2022-AQMP-with-appendices-20221130.pdf. White, R. 1963. Luiseño Social Organization. University of California Publications in American Archaeology and Ethnology 48:91194. Berkeley: University of California. 4.2 List of Preparers Dudek Rachel Struglia, PhD, AICP Project Manager Laura Masterson Environmental Planner Armando Gonzales Environmental Planner Melissa Blundell Biologist Joshua Saunders Environmental Planner Jennifer Reed Air Resources Specialist Heather McDaniel McDevitt Archaeologist Michael Williams Paleontologist Michael Green Environmental Acoustician Dana Link-Herrera Fire Protection Planner Kirsten Zecher GIS Analyst Lia Kershaw Technical Editor Felisa Pugay Formatting Specialist

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GRAPHIC SCALEIMPROVEMENTS KEY MAPSTORMWATER DIVERSION KEY MAP3CITY OF THOUSAND OAKS DWG. _________SHEET ___ OCITY OF THOUSAND OAKSCITY OF THOUSAND OAKSDATECHECKEDDATEDATEDESIGNEDDRAFTED BYPREPARED BYC.T.O.DATER.C.E. DATEREV. SYMBOLDESCRIPTION OF CHANGE20-22ADATEENGINEERING DIVISION MANAGERDATEREVIEWED BY:APPROVED BY:DATEPROJECT ENGINEERREVIEWED BY:XX/XX/XXXX/XX/XXXX/XX/XXCHGXXXXCHARLES H. GREELY R.C.E. No. 69056 DATE3685 Main Street, Suite 250Riverside, CA 92501951.300.2100 Fax 951.300.2105NADER HEYDARI, CITY ENGINEERHILL CANYON TREATMENT PLANT STORMWATER DIVERSION (CI 5427Project ImprovementsHill Canyon Treatment Plant Stormwater Diversion Project Initial Study/Mitigated Negative DeclarationFIGURE 4 Path: ZZ:\Projects\j1276700\MAPDOC\ISMNDSOURCE:

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Noise Measurement LocationsHill Canyon Treatment Plant Stormwater Diversion Project Initial Study/Mitigated Negative DeclarationSOURCE: NAIP 2020Date: 4/7/2023 - Last saved by: kzecher - Path: Z:\Projects\j1276700\MAPDOC\ISMND\Figure10_NoiseMeaurementLocs.mxd0 320160FeetProject SiteShort-Term NoiseMeasurement LocationFIGURE 10

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5 Response to Comments This section includes a copy of the comment letter that was received after the public review period of the IS/MND (Comment Letter 1) concluded. The City has included the letter here even though the agency had no comments on the project at this time. Pursuant to CEQA Guidelines Section 15074(b), decision makers will consider the proposed IS/MND together with the comments received during the public review process.

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Response to Comment Letter 1 California Department of Transportation Miya Edmonson, LDR/CEQA Branch Chief September 12, 2023 California Department of Transportation has no comment at this time.

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6 Mitigation Monitoring and Reporting Program California Public Resources Code, Section 21081.6, requires that, upon certification of an initial study/mitigated project or conditions of project approval, adopted in order to mitigate or avoid significant effects on the environment. 4 This Mitigation Monitoring and Reporting Program (presented in Table 6-1) has been developed in compliance with Section 21081.6 of the California Public Resources Code and Section 15097 of the California Environmental Quality Act Guidelines5 and includes the following information: A list of mitigation measures The timing for implementation of the mitigation measures The party responsible for implementing or monitoring the mitigation measures The date of completion of monitoring The City of Thousand Oaks must adopt this Mitigation Monitoring and Reporting Program, or an equally effective program, if it approves the proposed Hill Canyon Treatment Plant Stormwater Diversion Project (project) with the mitigation measures that were adopted or made conditions of project approval. 4 California Public Resources Code, Sections 2100021189. California Environmental Quality Act (CEQA), as amended. 5 14 CCR 1500015387 and Appendices AN. Guidelines for Implementation of the California Environmental Quality Act, as amended.

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion Biological Resources MM-BIO-1 Habitat Mitigation and Monitoring Plan. Prior to issuance of a project grading permit, the City of Thousand Oaks (City) shall contract with a qualified botanist/biologist to develop a Habitat Mitigation and Monitoring Reporting Plan (Plan) to provide compensatory mitigation for permanent impacts to 0.03 acres of lemonade berry scrub (Rhus integrifolia) and 0.06 acres of lemonade berry scrubCalifornia sagebrush scrub (Artemisia californica) (California Department of Fish and Wildlife sensitive vegetation communities). The Plan shall outline efforts to restore or enhance these sensitive vegetation communities and, therefore, preserve or provide wildlife habitat within similar upland habitats adjacent to the impacted biological resources. The Plan may focus on the following: In-kind restoration of lemonade berry scrub and/or lemonade berry scrubCalifornia sagebrush scrub through incorporation of these communities Restoration of areas occupied by non-native habitats or native habitats with large components of non-native vegetation, within similar habitats adjacent to the impacted biological resources Under the Plan, a total of 0.09 acres of permanently impacted upland vegetation communities shall be mitigated in-kind at a 2:1 ratio for a total of 0.18 acres of compensatory mitigation. A qualified biologist/botanist shall develop the Plan, which shall provide specific measures to restore or enhance habitat to replace the loss of permanently impacted communities. This Plan shall be focused on adaptive management principles and shall identify detailed enhancement areas and strategies based on the parameters outlined below, with long-term timing and monitoring requirements. The Plan shall also address the approximately 0.01 acres (315 square feet; 105 linear feet) of non-wetland waters of the State, including up to Prior to issuance of grading permits City of Thousand Oaks Public Works Department

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 145 FEBRUARY 2025
Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion mapped top of bank; and 0.01 acres (332 square feet) of riparian (blue elderberry scrub [Sambucus mexicana]) permanently impacted by the project. The Plan shall provide for compensatory mitigation at a minimum 3:1 ratio for in-kind or similar mitigation, or other compensatory mitigation approved by the regulatory agencies. Specifically, the Plan will prescribe actions and measures to compensate for project impacts. The Plan will present project impacts, the site selection process, and a rationale for success; specifications regarding final mitigation acreages, site preparation, restoration implementation, plant and seed collection source and sizing; project implementation guidelines; interim and final ecological performance standards; requirements for long-term maintenance, monitoring, and reporting; and site protection and long-term management. The Plan will include the following elements: Mitigation ratios for permanent and temporary impacts (if any) to regulated aquatic resources including, but not limited to, riparian habitat, waters of the United States, waters of the State, and CDFW streambed and riparian habitat established in consultation with the U.S. Army Corps of Engineers, Regional Water Quality Control Board, and California Department of Fish and Wildlife Provide site selection and justification Detailed descriptions of mitigation components proposed to achieve the compensatory mitigation requirements of the resource agency permits Plant palette(s) for each target vegetation community proposed to be restored to the mitigation site Defined attainable and measurable mitigation goals and objectives to be achieved through implementation of the Plan A restoration work plan that details the mitigation approach, a restoration schedule, plant materials (containers, seed), and implementation strategies

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion A detailed maintenance plan to include removal of invasives and non-native species Defined ecological performance standards for determining the success of the mitigation program A monitoring plan that includes method and analyses of results, goals for success or failure, and an adaptive management plan and suggestions for failed restoration efforts Restoration activities using native riparian and wetland species from locally collected stock, if applicable A description of protection measures and an estimate of long-term management funding An estimate of implementation costs Annual reports and the final report shall be submitted to the City and applicable regulatory agencies MM-BIO-2 Worker Education Awareness Program. Prior to the initiation of any site disturbance and/or construction activities, all personnel associated with the project shall attend a worker education awareness program (program) conducted by a qualified biologist. In general, it is recommended that the program discuss any potentially occurring sensitive biological resources or species and habitat preference(s), occupied habitat in the area, life histories, law and regulations, potential construction impacts and protection measures, and project limits. Protections and regulations for biological resources, special-status species, protection of aquatic resources and open space, and nesting birds shall also be included in the program. It is recommended that a species and habitat fact sheet also be developed prior to the training program and distributed at the training program to all contractors, employers, and other personnel involved with the construction of the project. After the kickoff meeting, the project proponent shall notify the qualified biologist in advance if additional contractors are employed during Prior to construction City of Thousand Oaks Public Works Department

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 147 FEBRUARY 2025
Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion construction. A sign-in sheet will be circulated for signatures to all personal that attend the workers educational training to confirm that program materials were received and that they understand information presented. MM-BIO-3 Delimiting Construction Area. Prior to initiation of ground disturbance, grading, or equipment mobilization, the following measures shall be implemented to protect natural resources adjacent to construction areas: Temporary fencing or equivalent form of demarcation shall be installed along the perimeter of defined construction areas to protect natural resources. All construction-related activities shall be confined to the designated construction areas within the fenced/demarcated areas. Fencing/demarcation shall be maintained during the duration of the project, including fixing or replacing downed fence. Fencing/demarcation shall remain in place for the duration of the project until all project activities are complete. A qualified biological monitor shall monitor the condition of the fence to ensure avoidance of impacts to surrounding resources. When sizable construction equipment is working near oak trees, it is highly encouraged that flaggers are utilized to assist in equipment positioning to avoid impacts to oak tree canopies (not proposed for removal) during construction activities Prior to construction City of Thousand Oaks Public Works Department MM-BIO-4 Biological Monitoring and Reporting. A qualified biologist shall be present during initial ground-disturbing activities (i.e., grading, trenching, vegetation trimming or clearing) occurring within undeveloped areas (i.e., not the existing developed Hill Canyon Treatment Plant areas). Each day prior to equipment mobilization, the biologist shall perform a clearance survey in which the work area and equipment within undeveloped areas is inspected for wildlife. The biologist shall provide guidance and ensure that biological resource protection measures are in During construction City of Thousand Oaks Public Works Department

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion place to the maximum extent feasible. The monitor shall be experienced in construction monitoring and be able to identify potentially occurring sensitive biological resources in the area, including the coastal California gnatcatcher (Polioptila californica californica). The monitor shall survey the construction project footprint and surrounding areas for compliance with all environmental specifications. The biologist shall have authority to halt work if listed species are observed and immediately notify California Department of Fish and Wildlife and/or U.S. Fish and Wildlife Service (as applicable), and additional appropriate avoidance and minimization measures shall be implemented if determined necessary for the protection of special-status species. Sensitive wildlife species may only be moved from the work area by qualified biologists holding the required permits; however, endangered or threatened species will not be moved, harassed, or harmed and will be allowed to move out of harm on their own (unless other arrangements are approved by the regulatory agencies). Daily biological construction monitoring reports shall be prepared by the biologist and submitted to the appropriate permitting and responsible agencies on a weekly basis (weekly reporting). In addition, at the completion of monitoring activities, the biologist will submit a final monitoring report to the appropriate permitting and responsible agencies to document compliance with environmental requirements. MM-BIO-5 Erosion and Sediment Control Plan. Due to the project impact of less than 1 acre, the applicant shall prepare an Erosion and Sediment Control Plan (ESCP) to minimize the potential for discharge of pollutants during construction activities. The ESCP shall be designed to meet the local requirements and Ventura County permitting process (e.g., grading or building permit). The ESCP shall include both structural and non-structural best management practices (BMPs), including straw wattles around storm drains, silt fencing and or other physical controls to divert Prior to construction, during construction City of Thousand Oaks Public Works Department

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 149 FEBRUARY 2025
Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion flows from exposed soil, spill prevention methods, and clean housekeeping methods for storing and refueling machinery. As part of the ESCP, the contractor shall include specifications, installation requirements, and locations of appropriate BMPs to control sediment, coarse particles, concrete, and other materials exposed during construction and drilling, to protect aquatic and riparian habitats adjacent to construction site. Erosion control measures shall be implemented to prevent runoff of these materials into potential jurisdictional aquatic features. Silt fencing, straw bales, and/or sandbags shall be used in conjunction with other methods to prevent turbid waters from entering the potential jurisdictional aquatic features. BMPs shall be implemented that minimize impacts from the generation of fugitive dust, fire hazards, and chemical pollutants. During construction activities, washing of concrete or equipment shall occur only in areas where polluted water and materials can be contained for subsequent removal from the site. Washing shall not be allowed in locations where the tainted water could enter potential jurisdictional aquatic features. MM-BIO-6 Protected Tree Removal, Replacement, and Protective Measures. The City of Thousand Oaks requires a permit for removal, pruning, or encroachment into the protected zone of any oak tree or landmark tree, which are defined as: Oak Tree: Any oak tree of the genus Quercus including, but not limited to, valley oak (Quercus lobata), California live oak (Quercus agrifolia) and scrub oak (Quercus berberidifolia), regardless of size (Thousand Oaks Municipal Code, Title 5, Chapter 14: Oak Tree Preservation and Protection). Prior to construction City of Thousand Oaks Public Works Department

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 150 FEBRUARY 2025
Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion Landmark Tree: Specimens of the following species that have reached the designated maturity: California sycamore (Platanus racemosa), which exceed 12 inches in diameter when measured at a point 4.5 feet above the natural grade at the base of the tree; California bay laurel (Umbellularia californica), which exceed 8 inches in diameter when measured at a point 4.5 feet above the natural grade at the base of the tree; California black walnut (Juglans californica), which exceed 8 inches in diameter when measured at a point 4.5 feet above the natural grade at the base of the tree; and toyon (Heteromeles arbutifolia), which exceed 8 inches in diameter when measured at a point 4.5 feet above the natural grade at the base of the tree. Trees with multiple trunks shall be deemed to have reached maturity if the sum of the diameters of the multiple trunks exceeds the required diameter plus 2 inches of a single trunked tree. Landmark trees shall also include all designated historic trees. (Thousand Oaks Municipal Code, Title 5, Chapter 24: Landmark Tree Preservation and Protection). Prior to construction activities, an International Society of Arboriculture-certified arborist shall review the proposed construction plans, visit the project site, and assess the condition, health, and structure of oak and landmark trees with a potential to be directly (removed or encroached upon) impacted by project activities, including trees proposed to be trimmed or removed. Encroachment shall include project-related disturbances that will occur within the protected zone (a specifically defined area totally encompassing a landmark or historic tree within which work activities are strictly controlled). When depicted on a map, the outermost edge of the protected zone will appear as an irregularly shaped circle that follows the contour of the dripline of the tree. Using the dripline as a point of reference, the protected zone shall commence at a point 5 feet outside of the dripline and extend inward to the trunk of the tree. In no case shall the protected zone be less than 15 feet from the trunk of a landmark tree (both code sections).

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion The certified arborist shall provide a letter/report (Oak Tree Report) containing specific information on the location, condition, potential impacts of development, recommended actions, and mitigation measures. At minimum, mitigation measures shall include requirements for arborist monitoring during work within the tree protected zone (i.e., within 5 feet of the oak tree canopy or within 15 feet from the base of the tree trunk) of any oak or landmark trees. The City of Thousand Oaks Oak Tree Preservation and Protection Guidelines mitigation requirements for tree removals associated with development projects are summarized as follows: one 15-gallon oak tree must be planted or donated for each dead or hazardous oak tree removed; two 24-inch box trees and one 36-inch or 60-inch box tree must be planted for each healthy oak tree removed for commercial, industrial, and new residential development projects; and, in the case of removal of oak trees larger than 48 inches in diameter, the applicant is required to obtain the largest nursery-grown oak tree available or plant two 60-inch box trees. MM-BIO-7 Reptile Pre-Construction Survey. A pre-construction survey for California legless lizard (Anniella sp.), San Diegan tiger whiptail (Aspidoscelis tigris stejnegeriPhrynosoma blainvillii) shall be conducted 30 days prior to the initiation of project activities. If these species are observed, a salvage and relocation plan shall be implemented to allow a qualified biologist to capture and relocate the species away from ground disturbance and into protected open space. These survey and reporting measures are often a condition of the Agreement. Prior to construction City of Thousand Oaks Public Works Department MM-BIO-8 Pre-Construction Nesting Bird Survey. A pre-construction survey for nesting birds shall be conducted by a City of Thousand Oaks-approved biologist to determine if active (nests containing eggs, nestlings, or associated with dependent fledglings) of special-status birds, or common bird species protected by the Migratory Bird Treaty Act and/or the California Fish and Game Code, are present in the Prior to construction City of Thousand Oaks Public Works Department

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion construction zone or within 300 feet of the construction zone. The survey shall be conducted within 1 week prior to construction or site preparation activities that will occur during the nesting/breeding season of native bird species potentially nesting on the site (typically February 1 through August 31). The pre-construction nesting bird survey shall be repeated if there is a delay in the start of construction activity or if a lapse in construction activity of 2 weeks or greater has occurred. Within 1 week before the start of construction activities, a City of Thousand Oaks-approved biologist shall conduct the nesting bird survey. A pre-construction nesting bird report shall be completed and submitted to the City of Thousand Oaks within 48 hours of the survey. If active nests are found, a no-construction buffer shall be established at a minimum of 50 feet for non-raptor bird species and 200 feet for raptor species (this distance may be greater depending on the bird species and construction activity, as determined by the City of Thousand Oaks-approved biologist) around the nest site where it overlaps with work areas. Tree and vegetation clearing and construction within the no-construction buffer shall be postponed or halted, at the discretion of the City of Thousand Oaks-approved biologist, until the nest is vacated, juveniles have fledged, and there is no evidence of a second attempt at nesting. In addition, all active nests shall be mapped with a GPS unit and nest locations with 100-foot buffers overlain on aerial photographs to provide regular updated maps to inform the project manager/engineer and construction crew of areas to avoid. The City of Thousand Oaks-approved biologist shall also serve as a construction monitor during the breeding season to ensure that there are no inadvertent impacts to nesting birds. Bird nest surveys shall be conducted every 14 days following identification of an active bird nest until all birds have fled the nest and the nest is deemed inactive by the City of Thousand Oaks-approved biologist. A bird nest monitoring report shall be completed and submitted to the City of Thousand Oaks.

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion MM-BIO-9 Coastal California Gnatcatcher Surveys and Avoidance. Prior to construction, protocol-level surveys for the coastal California gnatcatcher (Polioptila californica californica) shall be performed within 500 feet of proposed temporary and permanent impact areas. If any individuals are detected during the surveys, the results shall be communicated to the U.S. Fish and Wildlife Service for approvals prior to construction. In the absence of protocol surveys, the U.S. Fish and Wildlife Service shall be consulted for further guidance. Prior to construction City of Thousand Oaks Public Works Department Cultural Resources MM-CUL-1 Cultural Resource Monitoring and Inadvertent Discovery Plan. The City of Thousand Oaks shall retain a Principal Investigator/Archaeologist to assess information available (final grading and construction plans, geotechnical testing results, as-built plans, etc.) and determine the depth at which native soils exist and would be impacted by project implementation. The depth of native soils shall be included in the cultural resource monitoring and inadvertent discovery plan (Plan) so as to guide when monitoring is required. Impacts to cultural resources shall be minimized through implementation of pre- and post-construction tasks. Tasks pertaining to cultural resources include the development of the Plan. The purpose of the Plan is to outline a program of treatment and mitigation in the case of an inadvertent discovery of cultural resources during ground-disturbing activities and to provide for the proper identification, evaluation, treatment, and protection of any cultural resources throughout the duration of the project. This Plan shall define the process to be followed for the identification and management of cultural resources in the project area during construction. Existence of and importance of adherence to this Plan shall be stated on all project site plans intended for use by those conducting the ground-disturbing activities. The Plan shall also include the conditions under which monitoring is required pursuant to MM-CUL-3 and the manner of facilitation Prior to construction, during construction, and post construction City of Thousand Oaks Public Works Department

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion MM-CUL-2 Worker Environmental Awareness Program Training. Prior to commencement of construction activities for all phases of project implementation, the City of Thousand Oaks shall retain a Principal Investigator/Archaeologist to prepare a Worker Environmental Awareness Program (WEAP). The WEAP shall be submitted to the City of Thousand Oaks for review and approval. All construction personnel and monitors who are not trained archaeologists shall be briefed regarding inadvertent discoveries prior to the start of construction activities. A basic presentation and handout or pamphlet shall be prepared to ensure proper identification and treatment of inadvertent discoveries. The purpose of the WEAP training is to provide specific details on the kinds of archaeological materials and Tribal Cultural Resources that may be identified during construction of the project and explain the importance of and legal basis for the protection of significant archaeological resources. Each worker shall also learn the proper procedures to follow in the event that cultural resources, Tribal Cultural Resources, or human remains are uncovered during ground-disturbing activities. These procedures shall include work curtailment or redirection, and the immediate contact of the site supervisor and archaeologist retained for the project. This requirement shall be noted on all construction plans to ensure implementation. Prior to construction City of Thousand Oaks Public Works Department MM-CUL-3 Archaeological Monitoring. An archaeological technician/monitor overseen by a Principal Investigator/Archaeologist shall observe ground-disturbing activities during initial excavation in native soils (outside the treatment plant boundary). Initial excavation is defined as initial construction-related earthmoving of sediments from their place of deposition. As it pertains to archaeological monitoring, this definition excludes movement of sediments after they have been initially disturbed or displaced by project-related construction. A Principal Investigator/ Archaeologist shall oversee and establish monitoring efforts as needed (increase, decrease, or discontinue monitoring frequency) based on the observed potential for construction During construction, post construction City of Thousand Oaks Public Works Department

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion activities to encounter cultural deposits or material. The archaeological monitor shall be responsible for maintaining daily monitoring logs. This requirement shall be noted on all construction plans to ensure implementation. Upon completion of all ground-disturbing activities, an archaeological monitoring report shall be prepared within 60 days following completion of ground disturbance and submitted to the City of Thousand Oaks for review. This report shall document compliance with approved mitigation, all conducted monitoring efforts, and include an appendix with daily monitoring logs. The final report shall be submitted to the City of Thousand Oaks and the applicable California Historical Resources Information System information center. MM-CUL-4 Inadvertent Discovery Clause. In the event that potential prehistoric or historic-era archaeological resources and/or Tribal Cultural Resources (sites, features, or artifacts) are exposed during construction activities for the project, all construction work occurring not less than 50 feet of the find shall immediately stop and the Principal Investigator/ Archaeologist must be notified immediately to assess of the discovery and determine whether additional study is warranted. Depending upon the nature of the discovery, the Principal Investigator/Archaeologist may simply record the find and allow work to continue. If the discovery proves potentially significant under the California Environmental Quality Act (CEQA), additional work such as subsurface testing may be warranted. If the discovery is determined significant under CEQA and avoidance is not feasible, data recovery will be required. In the event that human remains are inadvertently encountered during construction activities, the remains and associated resources shall be treated in accordance with state and local regulations that provide requirements with regard to the accidental discovery of human remains, including California Health and Safety Code Section 7050.5, California Public Resources Code Section 5097.98, and CEQA Guidelines Section During construction City of Thousand Oaks Public Works Department

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Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion 15064.5(e). In accordance with these regulations, if human remains are found, the County Coroner must be immediately notified of the discovery. No further excavation or disturbance of the project site or any nearby (no less than 100 feet) area reasonably suspected to overlie adjacent remains shall occur until the County Coroner has determined if the remains are potentially human in origin. If the County Coroner determines that the remains are, or are believed to be, Native American, he or she is required to immediately notify the Native American Heritage Commission (NAHC). The NAHC must immediately notify those persons it believes to be the most likely descendant from the deceased Native American. The most likely descendant must then complete their inspection and determine, in consultation with the property owner, the treatment and disposition of the human remains. Geology and Soils MM-GEO-1 Paleontological Resources Impact Mitigation Program and Paleontological Monitoring. Prior to commencement of any grading activity on site, the applicant shall retain a qualified paleontologist per the Society of Vertebrate Paleontology (2010) guidelines. The qualified paleontologist shall prepare a Paleontological Resources Impact Mitigation Program (PRIMP) for the proposed project. The PRIMP shall be consistent with the Society of Vertebrate Paleontology (2010) guidelines and outline requirements for pre-construction meeting attendance and worker environmental awareness training. The PRIMP shall include where paleontological monitoring is required within the project site based on construction plans and/or geotechnical reports and also include procedures for adequate paleontological monitoring and discoveries treatment, paleontological methods (including sediment sampling for microinvertebrate and microvertebrate fossils), reporting, and collections management. The qualified paleontologist shall attend the pre-construction meeting and a qualified paleontological monitor shall be on site during initial rough grading and other significant ground-disturbing activities (including augering) in previously undisturbed Conejo Volcanics Prior to construction, during construction City of Thousand Oaks Public Works Department

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 157 FEBRUARY 2025
Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion and below a depth of 5 feet below the surface in areas underlain by Holocene alluvial deposits. The qualified paleontological monitor shall also be on site during excavations to determine if the sedimentary portion of the Conejo Volcanics is being exposed and/or the Holocene alluvial deposits are old enough at depth to contain fossils. The qualified paleontologist shall determine how much monitoring is necessary based on subsurface conditions. In the event that paleontological resources (e.g., fossils) are unearthed during grading, the paleontological monitor will temporarily halt and/or divert grading activity to allow recovery of paleontological resources. The area of discovery will be roped off with a 50-foot radius buffer. Once documentation and collection of the find is completed, the monitor will allow grading to recommence in the area of the find. Hazards and Hazardous Materials See Wildfire for mitigation measure text. Prior to construction City of Thousand Oaks Public Works Department Wildfire MM-FIRE-1 Construction Fire Prevention Plan. The City of Thousand Oaks shall prepare and implement a Construction Fire Prevention Plan (Plan) to ensure the safety of workers and the public during construction of the proposed project. The applicant must submit the Plan to the Ventura County Fire Department for review and approval prior to construction. The Plan shall include, but not be limited to, the following elements: Procedures for minimizing potential ignition, including vegetation clearing, parking requirements/restrictions, idling restrictions, smoking restrictions, proper use of gas-powered equipment, and hot work restrictions. Prior to construction City of Thousand Oaks Public Works Department

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / FINAL INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 12767 158 FEBRUARY 2025
Table 6-1. Mitigation Monitoring and Reporting Program Applicant Proposed Measures/Mitigation Measures Implementation Timing Party Responsible for Implementation and Monitoring Date of Completion Work restrictions during Red Flag Warnings and High to Extreme Fire Danger days. All internal combustion engines used at the proposed project site shall be equipped with spark arrestors. Spark arrestors shall be in good working order. Fire rules shall be posted and visible all to employees at the Equipment parking areas and small stationary engine sites shall be cleared of all flammable materials. Smoking shall be prohibited in all vegetated areas and within 50 feet of combustible materials storage and shall be limited to paved areas or areas cleared of all vegetation. During construction, fire extinguishers and fire-fighting equipment sufficient to extinguish small fires shall be available on site and all construction vehicles shall be equipped with a fire extinguisher. All construction workers visiting the project site shall receive training on fire prevention procedures, the proper use of fire-fighting equipment, and procedures to be followed in the event of a fire. Fires ignited on site shall be immediately reported to the Ventura County Fire Department. The engineering, procurement, and construction contract(s) for the proposed project shall provide reference to or clearly state the requirements of this mitigation measure.

Appendix A Air Quality, Greenhouse Gas Emissions, Energy Calculations

HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 1 / 31
Hill Canyon Treatment Plant Stormwater Diversion Project Detailed ReportTable of Contents1. Basic Project Information1.1. Basic Project Information1.2. Land Use Types1.3. User-Selected Emission Reduction Measures by Emissions Sector2. Emissions Summary2.1. Construction Emissions Compared Against Thresholds2.2. Construction Emissions by Y ear, Unmitigated3. Construction Emissions Details3.1. Demolition (2025) - Unmitigated3.3. Site Preparation (2025) - Unmitigated3.5. Grading (2025) - Unmitigated3.7. Building Construction (2025) - Unmitigated3.9. Building Construction (2025) - Unmitigated3.11. Paving (2025) - Unmitigated HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 2 / 31

4. Operations Emissions Details4.10. Soil Carbon Accumulation By Vegetation Type4.10.1. Soil Carbon Accumulation By Vegetation Type - Unmitigated4.10.2. Above and Belowground Carbon Accumulation by Land Use Type - Unmitigated4.10.3. Avoided and Sequestered Emissions by Species - Unmitigated5. Activity Data5.1. Construction Schedule5.2. Off-Road Equipment5.2.1. Unmitigated5.3. Construction Vehicles5.3.1. Unmitigated5.4. Vehicles5.4.1. Construction Vehicle Control Strategies5.5. Architectural Coatings5.6. Dust Mitigation5.6.1. Construction Earthmoving Activities5.6.2. Construction Earthmoving Control Strategies HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 3 / 31

5.7. Construction Paving5.8. Construction Electricity Consumption and Emissions Factors5.18. Vegetation5.18.1. Land Use Change5.18.1.1. Unmitigated5.18.1. Biomass Cover Type5.18.1.1. Unmitigated5.18.2. Sequestration5.18.2.1. Unmitigated6. Climate Risk Detailed Report6.1. Climate Risk Summary6.2. Initial Climate Risk Scores6.3. Adjusted Climate Risk Scores6.4. Climate Risk Reduction Measures7. Health and Equity Details7.1. CalEnviroScreen 4.0 Scores7.2. Healthy Places Index Scores HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 4 / 31

7.3. Overall Health & Equity Scores7.4. Health & Equity Measures7.5. Evaluation Scorecard7.6. Health & Equity Custom Measures8. User Changes to Default Data HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 5 / 31

1. Basic Project Information1.1. Basic Project InformationData FieldValueProject Name Hill Canyon Treatment Plant Stormwater Diversion ProjectConstruction Start Date 1/7/2025Lead Agency —Land Use Scale Project/siteAnalysis Level for Defaults CountyWindspeed (m/s) 2.70Precipitation (days) 10.4Location 34.21170335634062, -118.92241248218829County VenturaCity Thousand OaksAir District Ventura County APCDAir Basin South Central CoastTAZ 3512EDFZ 8Electric Utility Southern California EdisonGas Utility Southern California GasApp Version 2022.1.1.71.2. Land Use TypesLand Use SubtypeSizeUnitLot AcreageBuilding Area (sq ft)Landscape Area (sqft)Special LandscapeArea (sq ft)PopulationDescriptionGeneral LightIndustry1.00 1000sqft 0.02 1,000 0.00 0.00 — — HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 6 / 31

1.3. User-Selected Emission Reduction Measures by Emissions SectorNo measures selected2. Emissions Summary2.1. Construction Emissions Compared Against ThresholdsCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)Un/Mit.TOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eDaily,Summer(Max)—————————————————— — 4,1732.220.070.174,1454,1450.790.110.681.200.600.740.0325.317.01.982.32Unmit.Daily,Winter(Max)—————————————————— — 2,1300.060.120.072,0922,0920.310.120.210.830.600.230.029.596.640.680.82Unmit.AverageDaily(Max)—————————————————— — 6650.200.020.036596590.120.030.090.220.120.100.013.692.530.280.34Unmit.Annual(Max)—————————————————— — 1100.03< 0.005< 0.0051091090.02< 0.0050.020.040.020.02< 0.0050.670.460.050.06Unmit.2.2. Construction Emissions by Y ear, UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)Y earTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eDaily -Summer(Max)—————————————————— HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 7 / 31
2025 2.32 1.98 17.0 25.3 0.03 0.74 0.60 1.20 0.68 0.11 0.79 — 4,145 4,145 0.17 0.07 2.22 4,173Daily -Winter(Max)— — — — — — — — — — — — — — — — — —2025 0.82 0.68 6.64 9.59 0.02 0.23 0.60 0.83 0.21 0.12 0.31 — 2,092 2,092 0.07 0.12 0.06 2,130AverageDaily— — — — — — — — — — — — — — — — — —2025 0.34 0.28 2.53 3.69 0.01 0.10 0.12 0.22 0.09 0.03 0.12 — 659 659 0.03 0.02 0.20 665Annual — — — — — — — — — — — — — — — — — —2025 0.06 0.05 0.46 0.67 < 0.005 0.02 0.02 0.04 0.02 < 0.005 0.02 — 109 109 < 0.005 < 0.005 0.03 1103. Construction Emissions Details3.1. Demolition (2025) - UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)LocationTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eOnsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.47 0.39 3.48 4.77 0.01 0.11 — 0.11 0.10 — 0.10 — 676 676 0.03 0.01 — 679Demolition— — — — — — 0.19 0.19 — 0.03 0.03 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00AverageDaily— — — — — — — — — — — — — — — — — — HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 8 / 31
Off-RoadEquipment0.03 0.03 0.24 0.33 < 0.005 0.01 — 0.01 0.01 — 0.01 — 46.3 46.3 < 0.005 < 0.005 — 46.5Demolition— — — — — — 0.01 0.01 — < 0.005 < 0.005 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Off-RoadEquipment0.01 < 0.005 0.04 0.06 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 7.67 7.67 < 0.005 < 0.005 — 7.70Demolition— — — — — — < 0.005 < 0.005 — < 0.005 < 0.005 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Offsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Worker 0.04 0.03 0.04 0.43 0.00 0.00 0.10 0.10 0.00 0.02 0.02 — 95.8 95.8 < 0.005 < 0.005 0.01 97.1Vendor 0.01 < 0.005 0.16 0.05 < 0.005 < 0.005 0.03 0.04 < 0.005 0.01 0.01 — 123 123 < 0.005 0.02 0.01 129Hauling 0.01 0.01 0.38 0.09 < 0.005 < 0.005 0.07 0.08 < 0.005 0.02 0.02 — 277 277 0.01 0.04 0.02 290AverageDaily— — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.03 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 — 6.61 6.61 < 0.005 < 0.005 0.01 6.71Vendor < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 8.45 8.45 < 0.005 < 0.005 0.01 8.84Hauling < 0.005 < 0.005 0.03 0.01 < 0.005 < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 — 19.0 19.0 < 0.005 < 0.005 0.02 19.9Annual — — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 1.09 1.09 < 0.005 < 0.005 < 0.005 1.11Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 1.40 1.40 < 0.005 < 0.005 < 0.005 1.46Hauling < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 3.14 3.14 < 0.005 < 0.005 < 0.005 3.30 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 9 / 31

3.3. Site Preparation (2025) - UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)LocationTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eOnsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.26 0.21 2.20 3.82 0.01 0.08 — 0.08 0.08 — 0.08 — 581 581 0.02 < 0.005 — 583DustFromMaterialMovement— — — — — — 0.00 0.00 — 0.00 0.00 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00AverageDaily— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.02 0.02 0.21 0.37 < 0.005 0.01 — 0.01 0.01 — 0.01 — 55.7 55.7 < 0.005 < 0.005 — 55.9DustFromMaterialMovement— — — — — — 0.00 0.00 — 0.00 0.00 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Off-RoadEquipment< 0.005 < 0.005 0.04 0.07 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 9.22 9.22 < 0.005 < 0.005 — 9.25 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 10 / 31
———————0.000.00—0.000.00——————DustFromMaterialMovementOnsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Offsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Worker 0.03 0.03 0.03 0.34 0.00 0.00 0.08 0.08 0.00 0.02 0.02 — 76.7 76.7 < 0.005 < 0.005 0.01 77.6Vendor 0.01 < 0.005 0.16 0.05 < 0.005 < 0.005 0.03 0.04 < 0.005 0.01 0.01 — 123 123 < 0.005 0.02 0.01 129Hauling 0.01 < 0.005 0.19 0.05 < 0.005 < 0.005 0.04 0.04 < 0.005 0.01 0.01 — 139 139 < 0.005 0.02 0.01 145AverageDaily— — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.03 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 — 7.40 7.40 < 0.005 < 0.005 0.01 7.51Vendor < 0.005 < 0.005 0.02 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 11.8 11.8 < 0.005 < 0.005 0.01 12.4Hauling < 0.005 < 0.005 0.02 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 13.3 13.3 < 0.005 < 0.005 0.01 13.9Annual — — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 1.23 1.23 < 0.005 < 0.005 < 0.005 1.24Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 1.96 1.96 < 0.005 < 0.005 < 0.005 2.05Hauling < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 2.20 2.20 < 0.005 < 0.005 < 0.005 2.313.5. Grading (2025) - UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)LocationTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eOnsite — — — — — — — — — — — — — — — — — — HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 11 / 31
Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.66 0.56 5.05 7.10 0.01 0.23 — 0.23 0.21 — 0.21 — 1,076 1,076 0.04 0.01 — 1,080DustFromMaterialMovement— — — — — — 0.40 0.40 — 0.04 0.04 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.66 0.56 5.05 7.10 0.01 0.23 — 0.23 0.21 — 0.21 — 1,076 1,076 0.04 0.01 — 1,080DustFromMaterialMovement— — — — — — 0.40 0.40 — 0.04 0.04 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00AverageDaily— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.05 0.04 0.35 0.49 < 0.005 0.02 — 0.02 0.01 — 0.01 — 73.7 73.7 < 0.005 < 0.005 — 74.0DustFromMaterialMovement— — — — — — 0.03 0.03 — < 0.005 < 0.005 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Off-RoadEquipment0.01 0.01 0.06 0.09 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 12.2 12.2 < 0.005 < 0.005 — 12.2 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 12 / 31
DustFromMaterialMovement— — — — — — < 0.005 < 0.005 — < 0.005 < 0.005 — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Offsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Worker 0.05 0.04 0.04 0.63 0.00 0.00 0.13 0.13 0.00 0.03 0.03 — 134 134 0.01 < 0.005 0.54 136Vendor 0.01 < 0.005 0.15 0.05 < 0.005 < 0.005 0.03 0.04 < 0.005 0.01 0.01 — 123 123 < 0.005 0.02 0.35 129Hauling 0.01 < 0.005 0.18 0.04 < 0.005 < 0.005 0.04 0.04 < 0.005 0.01 0.01 — 139 139 < 0.005 0.02 0.31 145Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Worker 0.05 0.04 0.05 0.57 0.00 0.00 0.13 0.13 0.00 0.03 0.03 — 128 128 0.01 < 0.005 0.01 129Vendor 0.01 < 0.005 0.16 0.05 < 0.005 < 0.005 0.03 0.04 < 0.005 0.01 0.01 — 123 123 < 0.005 0.02 0.01 129Hauling 0.01 < 0.005 0.19 0.05 < 0.005 < 0.005 0.04 0.04 < 0.005 0.01 0.01 — 139 139 < 0.005 0.02 0.01 145AverageDaily— — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.04 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 — 8.81 8.81 < 0.005 < 0.005 0.02 8.94Vendor < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 8.45 8.45 < 0.005 < 0.005 0.01 8.84Hauling < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 9.49 9.49 < 0.005 < 0.005 0.01 9.95Annual — — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 1.46 1.46 < 0.005 < 0.005 < 0.005 1.48Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 1.40 1.40 < 0.005 < 0.005 < 0.005 1.46Hauling < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 1.57 1.57 < 0.005 < 0.005 < 0.005 1.653.7. Building Construction (2025) - Unmitigated HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 13 / 31
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)LocationTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eOnsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.92 0.77 6.93 9.51 0.01 0.31 — 0.31 0.28 — 0.28 — 1,433 1,433 0.06 0.01 — 1,438Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Daily,Winter(Max)— — — — — — — — — — — — — — — — — —AverageDaily— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.13 0.11 0.95 1.30 < 0.005 0.04 — 0.04 0.04 — 0.04 — 196 196 0.01 < 0.005 — 197Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Off-RoadEquipment0.02 0.02 0.17 0.24 < 0.005 0.01 — 0.01 0.01 — 0.01 — 32.5 32.5 < 0.005 < 0.005 — 32.6Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Offsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Worker 0.04 0.03 0.04 0.50 0.00 0.00 0.10 0.10 0.00 0.02 0.02 — 107 107 < 0.005 < 0.005 0.43 109Vendor < 0.005 < 0.005 0.08 0.02 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 0.01 — 61.6 61.6 < 0.005 0.01 0.17 64.6Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 14 / 31
——————————————————Daily,Winter(Max)AverageDaily— — — — — — — — — — — — — — — — — —Worker 0.01 < 0.005 0.01 0.06 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 — 14.1 14.1 < 0.005 < 0.005 0.03 14.3Vendor < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 8.45 8.45 < 0.005 < 0.005 0.01 8.84Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 2.33 2.33 < 0.005 < 0.005 < 0.005 2.37Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 1.40 1.40 < 0.005 < 0.005 < 0.005 1.46Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.003.9. Building Construction (2025) - UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)LocationTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eOnsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.77 0.65 6.14 8.76 0.01 0.26 — 0.26 0.24 — 0.24 — 1,359 1,359 0.06 0.01 — 1,363Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Daily,Winter(Max)— — — — — — — — — — — — — — — — — —AverageDaily— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.06 0.05 0.50 0.72 < 0.005 0.02 — 0.02 0.02 — 0.02 — 112 112 < 0.005 < 0.005 — 112 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 15 / 31
Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Off-RoadEquipment0.01 0.01 0.09 0.13 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 18.5 18.5 < 0.005 < 0.005 — 18.6Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Offsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Worker 0.08 0.07 0.07 1.01 0.00 0.00 0.21 0.21 0.00 0.05 0.05 — 214 214 0.01 0.01 0.86 217Vendor < 0.005 < 0.005 0.08 0.02 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 0.01 — 61.6 61.6 < 0.005 0.01 0.17 64.6Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Daily,Winter(Max)— — — — — — — — — — — — — — — — — —AverageDaily— — — — — — — — — — — — — — — — — —Worker 0.01 0.01 0.01 0.08 0.00 0.00 0.02 0.02 0.00 < 0.005 < 0.005 — 16.9 16.9 < 0.005 < 0.005 0.03 17.2Vendor < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 5.07 5.07 < 0.005 < 0.005 0.01 5.30Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 2.80 2.80 < 0.005 < 0.005 0.01 2.84Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 0.84 0.84 < 0.005 < 0.005 < 0.005 0.88Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.003.11. Paving (2025) - UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)LocationTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2e HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 16 / 31
Onsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.47 0.39 3.58 4.97 0.01 0.17 — 0.17 0.15 — 0.15 — 748 748 0.03 0.01 — 751Paving — 0.03 — — — — — — — — — — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Daily,Winter(Max)— — — — — — — — — — — — — — — — — —AverageDaily— — — — — — — — — — — — — — — — — —Off-RoadEquipment0.02 0.02 0.15 0.20 < 0.005 0.01 — 0.01 0.01 — 0.01 — 30.7 30.7 < 0.005 < 0.005 — 30.8Paving — < 0.005 — — — — — — — — — — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Off-RoadEquipment< 0.005 < 0.005 0.03 0.04 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 5.09 5.09 < 0.005 < 0.005 — 5.11Paving — < 0.005 — — — — — — — — — — — — — — — —Onsitetruck0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Offsite — — — — — — — — — — — — — — — — — —Daily,Summer(Max)— — — — — — — — — — — — — — — — — —Worker 0.04 0.03 0.03 0.47 0.00 0.00 0.10 0.10 0.00 0.02 0.02 — 100 100 < 0.005 < 0.005 0.40 102Vendor < 0.005 < 0.005 0.08 0.02 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 0.01 — 61.6 61.6 < 0.005 0.01 0.17 64.6Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 17 / 31
Daily,Winter(Max)— — — — — — — — — — — — — — — — — —AverageDaily— — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 0.02 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 3.97 3.97 < 0.005 < 0.005 0.01 4.02Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 2.53 2.53 < 0.005 < 0.005 < 0.005 2.65Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00Annual — — — — — — — — — — — — — — — — — —Worker < 0.005 < 0.005 < 0.005 < 0.005 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 0.66 0.66 < 0.005 < 0.005 < 0.005 0.67Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 0.42 0.42 < 0.005 < 0.005 < 0.005 0.44Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.004. Operations Emissions Details4.10. Soil Carbon Accumulation By Vegetation Type4.10.1. Soil Carbon Accumulation By Vegetation Type - UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)VegetationTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eDaily,Summer(Max)— — — — — — — — — — — — — — — — — —Total — — — — — — — — — — — — — — — — — —Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Total — — — — — — — — — — — — — — — — — —Annual — — — — — — — — — — — — — — — — — — HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 18 / 31
Total — — — — — — — — — — — — — — — — — —4.10.2. Above and Belowground Carbon Accumulation by Land Use Type - UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)LandUseTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eDaily,Summer(Max)— — — — — — — — — — — — — — — — — —Total — — — — — — — — — — — — — — — — — —Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Total — — — — — — — — — — — — — — — — — —Annual — — — — — — — — — — — — — — — — — —Total — — — — — — — — — — — — — — — — — —4.10.3. Avoided and Sequestered Emissions by Species - UnmitigatedCriteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)SpeciesTOGROGNOxCOSO2PM10EPM10DPM10TPM2.5EPM2.5DPM2.5TBCO2NBCO2CO2TCH4N2ORCO2eDaily,Summer(Max)— — — — — — — — — — — — — — — — — —Avoided — — — — — — — — — — — — — — — — — —Subtotal — — — — — — — — — — — — — — — — — —Sequestered— — — — — — — — — — — — — — — — — —Subtotal — — — — — — — — — — — — — — — — — —Removed— — — — — — — — — — — — — — — — — — HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 19 / 31
Subtotal — — — — — — — — — — — — — — — — — —— — — — — — — — — — — — — — — — — — —Daily,Winter(Max)— — — — — — — — — — — — — — — — — —Avoided — — — — — — — — — — — — — — — — — —Subtotal — — — — — — — — — — — — — — — — — —Sequestered— — — — — — — — — — — — — — — — — —Subtotal — — — — — — — — — — — — — — — — — —Removed— — — — — — — — — — — — — — — — — —Subtotal — — — — — — — — — — — — — — — — — —— — — — — — — — — — — — — — — — — — —Annual — — — — — — — — — — — — — — — — — —Avoided — — — — — — — — — — — — — — — — — —Subtotal — — — — — — — — — — — — — — — — — —Sequestered— — — — — — — — — — — — — — — — — —Subtotal — — — — — — — — — — — — — — — — — —Removed— — — — — — — — — — — — — — — — — —Subtotal — — — — — — — — — — — — — — — — — —— — — — — — — — — — — — — — — — — — —5. Activity Data5.1. Construction SchedulePhase NamePhase TypeStart DateEnd DateDays Per WeekWork Days per PhasePhase Description HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 20 / 31
Demolition Demolition 1/27/2025 2/28/2025 5.00 25.0 —Site Preparation andVegetation RemovalSite Preparation 1/6/2025 2/21/2025 5.00 35.0 —Grading Grading 3/03/2025 4/04/2025 5.00 25.0 —Basin Construction Building Construction 4/7/2025 6/13/2025 5.00 50.0 —Storm Drain/Outlet PipeConstructionBuilding Construction 5/5/2025 6/13/2025 5.00 30.0 —Paving - Trench Repair andPatchingPaving 6/9/2025 6/27/2025 5.00 15.0 —5.2. Off-Road Equipment5.2.1. UnmitigatedPhase NameEquipment TypeFuel TypeEngine TierNumber per DayHours Per DayHorsepowerLoad FactorDemolition Concrete/IndustrialSawsDiesel Average 1.00 8.00 33.0 0.73Site Preparation andVegetation RemovalTractors/Loaders/BackhoesDiesel Average 2.00 8.00 84.0 0.37Grading Graders Diesel Average 1.00 6.00 148 0.41Grading Tractors/Loaders/BackhoesDiesel Average 2.00 7.00 84.0 0.37Basin Construction Tractors/Loaders/BackhoesDiesel Average 2.00 8.00 84.0 0.37Paving - Trench Repairand PatchingPavers Diesel Average 1.00 8.00 81.0 0.42Paving - Trench Repairand PatchingRollers Diesel Average 1.00 8.00 36.0 0.38Paving - Trench Repairand PatchingTractors/Loaders/BackhoesDiesel Average 1.00 8.00 84.0 0.37Storm Drain/Outlet PipeConstructionTractors/Loaders/BackhoesDiesel Average 1.00 8.00 84.0 0.37 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 21 / 31
Demolition Excavators Diesel Average 1.00 8.00 36.0 0.38Grading Excavators Diesel Average 1.00 8.00 36.0 0.38Basin Construction Graders Diesel Average 1.00 8.00 148 0.41Storm Drain/Outlet PipeConstructionRough Terrain Forklifts Diesel Average 1.00 8.00 96.0 0.40Storm Drain/Outlet PipeConstructionExcavators Diesel Average 1.00 8.00 36.0 0.38Storm Drain/Outlet PipeConstructionGraders Diesel Average 1.00 8.00 148 0.41Demolition Tractors/Loaders/BackhoesDiesel Average 1.00 8.00 84.0 0.37Basin Construction Excavators Diesel Average 2.00 8.00 36.0 0.385.3. Construction Vehicles5.3.1. UnmitigatedPhase NameTrip TypeOne-Way Trips per DayMiles per TripVehicle MixDemolition — — — —Demolition Worker 7.50 18.5 LDA,LDT1,LDT2Demolition Vendor 4.00 10.2 HHDT ,MHDTDemolition Hauling 4.00 20.0 HHDTDemolition Onsite truck 0.00 0.00 HHDTSite Preparation and VegetationRemoval— — — —Site Preparation and VegetationRemovalWorker 6.00 18.5 LDA,LDT1,LDT2Site Preparation and VegetationRemovalVendor 4.00 10.2 HHDT,MHDTSite Preparation and VegetationRemovalHauling 2.00 20.0 HHDT HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 22 / 31
Site Preparation and VegetationRemovalOnsite truck 0.00 0.00 HHDTGrading — — — —Grading Worker 10.0 18.5 LDA,LDT1,LDT2Grading Vendor 4.00 10.2 HHDT ,MHDTGrading Hauling 2.00 20.0 HHDTGrading Onsite truck 0.00 0.00 HHDTBasin Construction — — — —Basin Construction Worker 8.00 18.5 LDA,LDT1,LDT2Basin Construction Vendor 2.00 10.2 HHDT ,MHDTBasin Construction Hauling 0.00 20.0 HHDTBasin Construction Onsite truck 0.00 — HHDTPaving - Trench Repair and Patching — — — —Paving - Trench Repair and Patching Worker 7.50 18.5 LDA,LDT1,LDT2Paving - Trench Repair and Patching Vendor 2.00 10.2 HHDT ,MHDTPaving - Trench Repair and Patching Hauling 0.00 20.0 HHDTPaving - Trench Repair and Patching Onsite truck 0.00 — HHDTStorm Drain/Outlet Pipe Construction — — — —Storm Drain/Outlet Pipe Construction Worker 16.0 18.5 LDA,LDT1,LDT2Storm Drain/Outlet Pipe Construction Vendor 2.00 10.2 HHDT ,MHDTStorm Drain/Outlet Pipe Construction Hauling 0.00 20.0 HHDTStorm Drain/Outlet Pipe Construction Onsite truck 0.00 — HHDT5.4. Vehicles5.4.1. Construction Vehicle Control StrategiesNon-applicable. No control strategies activated by user.

HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 23 / 31

5.5. Architectural CoatingsPhase NameResidential Interior Area Coated(sq ft)Residential Exterior Area Coated(sq ft)Non-Residential Interior AreaCoated (sq ft)Non-Residential Exterior AreaCoated (sq ft)Parking Area Coated (sq ft)5.6. Dust Mitigation5.6.1. Construction Earthmoving ActivitiesPhase NameMaterial Imported (Cubic Y ards)Material Exported (Cubic Y ards)Acres Graded (acres)Material Demolished (Ton ofDebris)Acres Paved (acres)Demolition 0.00 0.00 0.00 215 —Site Preparation and VegetationRemoval0.00 0.00 52.5 0.00 —Grading 0.00 165 68.8 0.00 —Paving - Trench Repair andPatching0.00 0.00 0.00 0.00 0.185.6.2. Construction Earthmoving Control StrategiesNon-applicable. No control strategies activated by user.5.7. Construction PavingLand UseArea Paved (acres)% AsphaltGeneral Light Industry 0.18 100%5.8. Construction Electricity Consumption and Emissions FactorskWh per Y ear and Emission Factor (lb/MWh)Y earkWh per Y earCO2CH4N2O2025 0.00 532 0.03 < 0.005 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 24 / 31

5.18. Vegetation5.18.1. Land Use Change5.18.1.1. UnmitigatedVegetation Land Use TypeVegetation Soil TypeInitial AcresFinal Acres5.18.1. Biomass Cover Type5.18.1.1. UnmitigatedBiomass Cover TypeInitial AcresFinal Acres5.18.2. Sequestration5.18.2.1. UnmitigatedTree TypeNumberElectricity Saved (kWh/year)Natural Gas Saved (btu/year)6. Climate Risk Detailed Report6.1. Climate Risk SummaryCal-Adapt midcentury 2040–2059 average projections for four hazards are reported below for your project location. These are under Representation Concentration Pathway (RCP) 8.5 which assumes GHGemissions will continue to rise strongly through 2050 and then plateau around 2100.Climate HazardResult for Project LocationUnitTemperature and Extreme Heat 14.1 annual days of extreme heatExtreme Precipitation 4.95 annual days with precipitation above 20 mmSea Level Rise 0.00 meters of inundation depthWildfire 29.4 annual hectares burned HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 25 / 31
Temperature and Extreme Heat data are for grid cell in which your project are located. The projection is based on the 98th historical percentile of daily maximum/minimum temperatures from observedhistorical data (32 climate model ensemble from Cal-Adapt, 2040–2059 average under RCP 8.5). Each grid cell is 6 kilometers (km) by 6 km, or 3.7 miles (mi) by 3.7 mi.Extreme Precipitation data are for the grid cell in which your project are located. The threshold of 20 mm is equivalent to about ¾ an inch of rain, which would be light to moderate rainfall if received over a fullday or heavy rain if received over a period of 2 to 4 hours. Each grid cell is 6 kilometers (km) by 6 km, or 3.7 miles (mi) by 3.7 mi.Sea Level Rise data are for the grid cell in which your project are located. The projections are from Radke et al. (2017), as reported in Cal-Adapt (2040–2059 average under RCP 8.5), and consider differentincrements of sea level rise coupled with extreme storm events. Users may select from four model simulations to view the range in potential inundation depth for the grid cell. The four simulations makedifferent assumptions about expected rainfall and temperature are: Warmer/drier (HadGEM2-ES), Cooler/wetter (CNRM-CM5), Average conditions (CanESM2), Range of different rainfall and temperaturepossibilities (MIROC5). Each grid cell is 50 meters (m) by 50 m, or about 164 feet (ft) by 164 ft.Wildfire data are for the grid cell in which your project are located. The projections are from UC Davis, as reported in Cal-Adapt (2040–2059 average under RCP 8.5), and consider historical data of climate,vegetation, population density, and large (> 400 ha) fire history. Users may select from four model simulations to view the range in potential wildfire probabilities for the grid cell. The four simulations makedifferent assumptions about expected rainfall and temperature are: Warmer/drier (HadGEM2-ES), Cooler/wetter (CNRM-CM5), Average conditions (CanESM2), Range of different rainfall and temperaturepossibilities (MIROC5). Each grid cell is 6 kilometers (km) by 6 km, or 3.7 miles (mi) by 3.7 mi.6.2. Initial Climate Risk ScoresClimate HazardExposure ScoreSensitivity ScoreAdaptive Capacity ScoreVulnerability ScoreTemperature and Extreme Heat 1 0 0 N/AExtreme Precipitation N/A N/A N/A N/ASea Level Rise 1 0 0 N/AWildfire 1 0 0 N/AFlooding N/A N/A N/A N/ADrought N/A N/A N/A N/ASnowpack Reduction N/A N/A N/A N/AAir Quality Degradation 0 0 0 N/AThe sensitivity score reflects the extent to which a project would be adversely affected by exposure to a climate hazard. Exposure is rated on a scale of 1 to 5, with a score of 5 representing the greatestexposure.The adaptive capacity of a project refers to its ability to manage and reduce vulnerabilities from projected climate hazards. Adaptive capacity is rated on a scale of 1 to 5, with a score of 5 representing thegreatest ability to adapt.The overall vulnerability scores are calculated based on the potential impacts and adaptive capacity assessments for each hazard. Scores do not include implementation of climate risk reduction measures.6.3. Adjusted Climate Risk ScoresClimate HazardExposure ScoreSensitivity ScoreAdaptive Capacity ScoreVulnerability ScoreTemperature and Extreme Heat 1 1 1 2Extreme Precipitation N/A N/A N/A N/A HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 26 / 31
Sea Level Rise 1 1 1 2Wildfire 1 1 1 2Flooding N/A N/A N/A N/ADrought N/A N/A N/A N/ASnowpack Reduction N/A N/A N/A N/AAir Quality Degradation 1 1 1 2The sensitivity score reflects the extent to which a project would be adversely affected by exposure to a climate hazard. Exposure is rated on a scale of 1 to 5, with a score of 5 representing the greatestexposure.The adaptive capacity of a project refers to its ability to manage and reduce vulnerabilities from projected climate hazards. Adaptive capacity is rated on a scale of 1 to 5, with a score of 5 representing thegreatest ability to adapt.The overall vulnerability scores are calculated based on the potential impacts and adaptive capacity assessments for each hazard. Scores include implementation of climate risk reduction measures.6.4. Climate Risk Reduction Measures7. Health and Equity Details7.1. CalEnviroScreen 4.0 ScoresThe maximum CalEnviroScreen score is 100. A high score (i.e., greater than 50) reflects a higher pollution burden compared to other census tracts in the state.IndicatorResult for Project Census TractExposure Indicators —AQ-Ozone 51.0AQ-PM 40.6AQ-DPM 16.2Drinking Water 57.5Lead Risk Housing 8.94Pesticides 20.4Toxic Releases 24.4Traffic 82.7Effect Indicators — HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 27 / 31
CleanUp Sites 0.00Groundwater 50.9Haz Waste Facilities/Generators 74.1Impaired Water Bodies 96.8Solid Waste 0.00Sensitive Population —Asthma 3.33Cardio-vascular 9.61Low Birth Weights 30.6Socioeconomic Factor Indicators —Education 8.99Housing 2.62Linguistic 4.59Poverty 2.20Unemployment 29.47.2. Healthy Places Index ScoresThe maximum Health Places Index score is 100. A high score (i.e., greater than 50) reflects healthier community conditions compared to other census tracts in the state.IndicatorResult for Project Census TractEconomic —Above Poverty 99.21724625Employed 82.34312845Median HI 94.30257924Education —Bachelor's or higher 81.05992557High school enrollment 100Preschool enrollment 42.01206211 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 28 / 31
Transportation —Auto Access 98.98626973Active commuting 6.390350314Social —2-parent households 98.34466829Voting 95.13666111Neighborhood —Alcohol availability 92.62158347Park access 54.79276274Retail density 27.65302194Supermarket access 24.35519056Tree canopy 77.05633261Housing —Homeownership 99.40972668Housing habitability 98.57564481Low-inc homeowner severe housing cost burden 96.16322341Low-inc renter severe housing cost burden 85.05068651Uncrowded housing 96.93314513Health Outcomes —Insured adults 96.11189529Arthritis 11.9Asthma ER Admissions 90.4High Blood Pressure 5.0Cancer (excluding skin) 5.1Asthma 72.9Coronary Heart Disease 23.5Chronic Obstructive Pulmonary Disease 53.7 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 29 / 31
Diagnosed Diabetes 65.9Life Expectancy at Birth 58.9Cognitively Disabled 95.5Physically Disabled 88.8Heart Attack ER Admissions 79.4Mental Health Not Good 90.9Chronic Kidney Disease 45.1Obesity 80.7Pedestrian Injuries 19.6Physical Health Not Good 78.6Stroke 58.2Health Risk Behaviors —Binge Drinking 63.5Current Smoker 92.2No Leisure Time for Physical Activity 86.6Climate Change Exposures —Wildfire Risk 77.0SLR Inundation Area 0.0Children 94.5Elderly 6.6English Speaking 98.1Foreign-born 24.0Outdoor Workers 80.6Climate Change Adaptive Capacity —Impervious Surface Cover 89.8Traffic Density 64.9Traffic Access 23.0 HillCanyon Treatment PlantStormwater Diversion Project Detailed Report, 4/3/2023 30 / 31
Other Indices —Hardship 6.2Other Decision Support —2016 Voting 92.27.3. Overall Health & Equity ScoresMetricResult for Project Census TractCalEnviroScreen 4.0 Score for Project Location (a) 5.00Healthy Places Index Score for Project Location (b) 95.0Project Located in a Designated Disadvantaged Community (Senate Bill 535) NoProject Located in a Low-Income Community (Assembly Bill 1550) NoProject Located in a Community Air Protection Program Community (Assembly Bill 617) Noa: The maximum CalEnviroScreen score is 100. A high score (i.e., greater than 50) reflects a higher pollution burden compared to other census tracts in the state.b: The maximum Health Places Index score is 100. A high score (i.e., greater than 50) reflects healthier community conditions compared to other census tracts in the state.7.4. Health & Equity MeasuresNo Health & Equity Measures selected.7.5. Evaluation ScorecardHealth & Equity Evaluation Scorecard not completed.7.6. Health & Equity Custom MeasuresNo Health & Equity Custom Measures created.8. User Changes to Default DataScreenJustificationConstruction: Construction Phases Project-specific assumptions.Construction: Off-Road Equipment Project-specific assumptions.Construction: Trips and VMT Project-specific assumptions.

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Construction: Paving Project-specific assumptions.Construction: Dust From Material Movement Project-specific assumptions.

Hill Canyon Treatment Plant Stormwater Diversion Project Energy CalculationsConstructionSourcePercentTotal MT CO2DieselGasoline2025Off-road 78.1% 85 8,344Electricity0.0% 0Worker 8.8% 10 1,093Vendor 6.8% 7 726Hauling 6.3% 7 673Onsite Truck 0.0% 0 0Total100.0%1099,7431,093Gallons Appendix B1 Biological Resources Assessment Report

FINAL
MARCH 2023Prepared for:CITY OF THOUSAND OAKS2100 Thousand Oaks BoulevardThousand Oaks, California 91362Contact: Nader Heydari Prepared by:621 Chapala StreetSanta Barbara, California 93101Contact: Melissa Blundell

Printed on 30% post-consumer recycled material.

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Table of ContentsSECTION PAGE NO.Acronyms and Abbreviations............................................................................................................................................. v1 Introduction ..........................................................................................................................................................12 Project Description...............................................................................................................................................12.1 Project Background and Need...............................................................................................................12.2 Proposed Project Components..............................................................................................................22.3 Project Operational Characteristics.......................................................................................................32.4 Project Construction and Scheduling....................................................................................................33 Regulatory Framework.........................................................................................................................................33.1 Federal ....................................................................................................................................................33.2 State........................................................................................................................................................53.3 Local........................................................................................................................................................84 Methods............................................................................................................................................................. 114.1 Literature and Database Review ........................................................................................................ 114.2 Field Surveys........................................................................................................................................ 124.2.1 Vegetation Community and Land Cover Mapping ............................................................... 124.2.2 Flora........................................................................................................................................ 134.2.3 Fauna...................................................................................................................................... 144.2.4 Aquatic Resources Delineation............................................................................................. 154.2.5 Survey Limitations ................................................................................................................. 155 Results............................................................................................................................................................... 155.1 Summary.............................................................................................................................................. 155.2 Environmental Setting......................................................................................................................... 165.3 Vegetation Communities and Land Cover Types............................................................................... 175.4 City-Regulated Trees ........................................................................................................................... 195.5 Common Plant and Wildlife Species .................................................................................................. 195.6 Special-Status Plants and Wildlife...................................................................................................... 205.6.1 Special-Status Plant Species ................................................................................................ 205.6.2 Special-Status Wildlife Species............................................................................................. 215.7 Critical Habitat..................................................................................................................................... 245.8 Jurisdictional Aquatic Resources........................................................................................................ 245.9 Wildlife Corridors and Habitat Linkages............................................................................................. 256 Project Impacts ................................................................................................................................................. 256.1 Definition of Impacts........................................................................................................................... 25

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6.2 Explanation of Findings of Significance ............................................................................................. 266.3 Impacts to Vegetation Communities and Land Covers ..................................................................... 276.4 City-Regulated Trees ........................................................................................................................... 286.5 Impacts to Special-Status Plant Species ........................................................................................... 286.6 Impacts to Special-Status Wildlife Species........................................................................................ 296.6.1 Reptiles................................................................................................................................... 296.6.2 Special-Status Avian Species................................................................................................ 306.6.3 Birds Protected under the MBTA and/or CFGC.................................................................... 326.7 Impacts to Critical Habitat .................................................................................................................. 326.8 Impacts to Jurisdictional Aquatic Resources..................................................................................... 326.9 Impacts to Wildlife Corridors and Habitat Connectivity..................................................................... 336.10 Cumulative Impacts............................................................................................................................. 337 Recommended Measures ................................................................................................................................ 348 References ........................................................................................................................................................ 40TABLES1 Summary of Biological Survey Personnel and Conditions.............................................................................. 122 Vegetation and Land Cover Types within the BSA .......................................................................................... 173 Summary of City-Regulated Tree Species within the BSA .............................................................................. 194 Special-Status Plant Species Observed within the Biological Survey Area ................................................... 205 Special-Status Wildlife Species Observed or with a Moderate to High Potential to Occur........................... 226 Proposed Impacts to Vegetation and Land Cover Types within the BSA....................................................... 27FIGURES1 Project Location ................................................................................................................................................ 432 Project Site Plan................................................................................................................................................ 453 Vegetation Communities and Land Cover Types............................................................................................. 474 City-Regulated Trees ......................................................................................................................................... 495 Biological Resources......................................................................................................................................... 516 USFWS Critical Habitat ..................................................................................................................................... 537 Impacts to Biological Resources ...................................................................................................................... 55APPENDICESA 100% Site Plans (May 6, 2022)B Aquatic Resources Delineation ReportC Photo DocumentationD Plant and Wildlife Species Observed

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E Special-Status Plant Species Not Expected or with Low Potential to OccurF CDFW CNDDB FormG Special-Status Wildlife Species with Low Potential or Not Expected to Occur

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Acronyms and AbbreviationsAcronym/AbbreviationDefinitionARDR Aquatic Resources Delineation ReportBSA Biological Survey AreaCDFW California Department of Fish and WildlifeCEQA California Environmental Quality ActCESA California Endangered Species ActCFGC California Fish and Game Codecfs cubic feet per secondCNDDB California Natural Diversity DatabaseCNPS California Native Plant SocietyCRPR California Rare Plant RankFESA federal Endangered Species ActFP fully protectedIGP Industrial General PermitISA International Society of ArboricultureMBTA Migratory Bird Treaty ActMCV2 Manual of California Vegetation, Second EditionNONA Notice of Non-ApplicabilityRWQCB Regional Water Quality Control BoardTPZ tree protection zoneUSACE U.S. Army Corps of EngineersUSFWS U.S. Fish and Wildlife ServiceWL Watch List

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HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / BIOLOGICAL RESOURCES ASSESSMENT REPORT 127671MARCH 2023
1 IntroductionDudek has prepared this Biological Resources Assessment Report (report) on behalf of The City of Thousand Oaks (City) to identify the existing conditions, potential for sensitive biological resources to occur, identify impacts, and recommend measures to avoid and minimize impacts for biological resources within and adjacent the Hill Canyon Treatment Plant Stormwater Diversion Project (Project) site. The Project involves improvements to the Hill Canyon Treatment Plant (Treatment Plant) including the development of a new debris basin and storm drain improvements. The report also provides information which may be pertinent for review by other relevant regulatory resource agencies,including the U.S. Fish and Wildlife Service (USFWS), the U.S. Army Corps of Engineers (USACE), the Central CoastRegional Water Quality Control Board (RWQCB), and/or California Department of Fish andWildlife (CDFW).The Project site (552-013-001 and 667-012-017) is located at the Hill Canyon Treatment Plant (Figure 1, Project Location). The address for the Treatment Plant is 9600 Santa Rosa Road at the confluence of north and south Arroyo Conejo Creek and within the western limits of the City of Thousand Oaks in Ventura County, California. The Project site is bounded by Hill Canyon Fire Road to the northwest and undeveloped vegetated land to the north, east, and south. The area surrounding the Project site is predominantly open space, with residential and commercial properties approximately 0.25 miles south and east of the site.2 Project Description 2.1 Project Background and NeedThe Hill Canyon Treatment Plant, which is owned and operated by the City, provides wastewater treatment for the City of Thousand Oaks. The Treatment Plant is a 14 million gallon per day capacity wastewater treatment plant and currently treats an average of 8 million gallons of wastewater per day generated from its domestic, commercial, and industrial customers.The Treatment Plant is located at the confluence of two watersheds and experiences flooding after large storm events that exceed the capacity of some drainage facilities for conveying off-site flows. These high runoff events are followed by a subsequent cleanup and debris removal associated with run-on flows from the tributary canyons that overflow into the Treatment Plant. Under existing conditions, flows are intercepted by a concrete swale that sits behind an existing reinforced concrete wall, directing flows to drain inlets that connect to an existing 30-inch storm drain system. To maintain compliance with the Industria-Applicability (NONA) for the IGP requirements, the City disconnected the 30-inch storm drain from outletting off site and added a sump pump system to divert flows to an on-site basin. The City captures and treats all on-site stormwater flows through the wastewater treatment process. The maximum capacity of the existing 30-inch storm drain is 50 cubic feet per second (cfs). The 10-year combined peak flowrate of the two watersheds is 105 cfs. The City determined that it was not feasible to increase the size of the 30-inch storm drain due to space constraints within the Treatment Plant and therefore the proposed design flow is limited to the capacity of the existing 30-inch storm drain and another design solution to intercept, capture and contain storm water flows is necessary.Implementation of the Project would include reestablishing the existing 30-original off-site outlet, new pipes to contain on-site flows within the site and maintain NONA status related to the

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IGP, and a debris basin to contain flooding and the accompanying debris experienced after storm events associated with run-on flows from the tributary canyons that overflow onto the Project site.2.2 Proposed Project ComponentsProposed Project component are shown on Figure 2, Project Site Plan, and provided as Appendix A, 75% Site Plans (dated August 9, 2021). Existing30-inchStormDrainUnder existing conditions, the existing 30-inch storm drain ties into a sump pump system that diverts flows to the adjacent sludge drying beds. The diverted storm flows are combined with the wastewater flow through the Treatment Plant. The Project would demolish the sump pump and reestablish the connection to the existing 30-only to transport off-site flows from the adjacent canyon. No on-site stormwater flows will be captured in the pipeline and discharged off-site. The original outfall outlets to the South Arroyo Conejo Creek.The maximum capacity of the existing 30-inch storm drain is 50 cubic feet per second (cfs). The City determined that it is not feasible to increase the size of the 30-inch storm drain due to space constraints within the Treatment Plant. Therefore, the Project would be limited to the capacity of the existing 30-inch storm drain and another design solution to intercept, capture and contain storm water flows is necessary. ProposedStormDrainPipesUpstream of the demolished pipe segment, a proposed storm drain pipe (Pipe A) would divert on-site flows to the existing flow equalization basin (FEB) overflow structure which is routed to the sludge drying beds. The alignment of Pipe A would be within the existing FEB side slope. Pipe A would be 36-inches in diameter and have a full flow capacity of 55-cfs. A second proposed storm drain pipe (Pipe B) would receive off-site flows from the proposed channel at the upstream end and tie into the existing 30-inch storm drain at the downstream end. Pipe B would be 24-inches in diameter and have a full flow capacity of 93-cfs. A third proposed storm drain pipe (Pipe C) would receive off-site flows from the proposed debris basin at the upstream end and outlet to the proposed channel at the downstream end. Pipe C would be 24-inches in diameter and would have a full flow capacity of 50-cfs.ProposedDebrisBasinandChannelThe proposed debris basin would be incorporated at the upstream end of the eastern side of the Treatment Plant to intercept all debris and allow clear water flows to continue downstream into the storm drain pipe where it is routed to the outfall location. No other connections to the pipe are made. A proposed channel would connect to the proposed debris basin at the upstream end by Pipe C. The proposed channel would convey 50-cfs flows.ManholeandInletImprovementsAdditional improvements are proposed at the existing manhole and inlet area southwest of the proposed basin and drain pipe work areas. Manhole work area improvements include a combination of concrete grading and curb improvements.

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2.3 Project Operational CharacteristicsUpon completion of construction, the Project would continue providing wastewater treatment services for the City. Similar to the existing conditions, staff would occasionally visit the Project site for routine maintenance or in the event of an emergency. Operational impacts are considered to be minimal and very similar to the existing conditions.2.4 Project Construction and Scheduling Construction of the Project is anticipated to occur over approximately 6 months. Project construction includes demolition of the sump pump associated with the existing 30-inch storm drain, retaining wall structures, drainage features and vegetation, site preparation and grading, constructing three new storm drain pipes and concrete channel, a debris basin, retaining wall structures, and reconnection of the 30-inch storm pipe. Materials required for construction would include piping, concrete blocks for the walls, and concrete. Water for concrete installation, dust control and erosion control would also be required. The heavy equipment would include those typical for similar projects, including grading, dump trucks, backhoe loaders, skid steers, concrete mixers, etc. Staging and access work areas as well as fueling of equipment will occur within the existing Treatment Plant. Construction equipment will be restricted within the open space undeveloped areas (proposed debris basin). Work in this area will occur within the proposed basin impact areas and no staging or disturbances are proposed outside the Project component areas in undeveloped open space. No new lighting features are proposed adjacent to undeveloped open space (i.e., debris basin, storm drain pipes). Where present, oak tree overhead canopy will be preserved to the extent feasible. Some minor overhead clearance may be necessary where large equipment will require access or passage through a Project area. All oak tree work shall conform and abide by the provisions of the Oak Tree Ordinance, Title 5, Chapter 14 of the Thousand Oaks Municipal Code, and the Oak Tree Preservation and Protection Guidelines Res. No. 2010-014. As described under Section 6, all Project areas within undeveloped areas are considered permanent impacts and no temporary impact areas are proposed.3 Regulatory FrameworkThis section outlines the federal, State, and local regulations pertinent to the biological resources located on the Project site. Some of the biological resources that could be affected by the Project are regulated by resource agencies that often overlap in jurisdiction. This section identifies and discusses the various programs regulating federally and/or State-listed threatened or endangered plants and wildlife, sensitive vegetation communities, and jurisdictional aquatic resources, such as drainages, streambeds, riparian habitat, and wetlands.3.1 FederalFederalEndangeredSpeciesActThe federal Endangered Species Act (FESA) of 1973, as amended (16 USC 1531 et seq.), serves as the enacting legislation to list, conserve, and protect threatened and endangered species, and the ecosystems on which they depend, from extinction. In addition, for those wildlife species listed as federally endangered, FESA provides for the ability to designate critical habitat, defined as tha

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would potentially result in adverse impacts to threatened or endangered species includes any action that is authorized, funded, or carried out by a federal agency, that agency must consult with the USFWS to ensure that any such action is not likely to jeopardize the continued existence of any endangered species or threatened species or result in the destruction or adverse modification of designated critical habitat for that species. FESA Section 9(a)(1)(B) prohibits ass, 1532 (19)). With respect to any endangered species of plant, Sections 9(a)(2)(A) and 9(a)(2)(B) prohibit the possession, sale, and to possession any such species from areas under federal jurisdiction; maliciously damage or destroy any such species on any such area; or remove, cut, dig up, or damage or destroy any such species on any other area in knowing violation FESA Section 10(a)(1)(B), the USFWS may issue a permit for the take of threatened or endangered species provided MigratoryBirdTreatyActThe Migratory Bird Treaty Act (MBTA) regulates or prohibits taking, killing, possession of, or harm to migratory bird species listed in Title 50, Section 10.13 of the Code of Federal Regulations. The MBTA is an international treaty for the conservation and management of bird species that migrate through more than one country and is enforced in the United States by the USFWS. Hunting of specific migratory game birds is permitted under the regulations listed in Title 50, Section 20 of the Code of Federal Regulations. The MBTA was amended in 1972 to include protection for migratory birds of prey (raptors). Multiple federal and legal actions to the interpretation of the MBTA occurred between December 2017 and October 2021. The most recent action by the USFWS on the MBTA interpretation was published on October 4, 2021, and went into effect on December 3, 2021. In their summary of this final rule, the USFWS explained that the immediate effect of this final rule is to return to implementing the MBTA as prohibiting incidental take and applying enforcement discretion, consistent with judicial precedent and longstanding agency CleanWaterActSection404The objective of the Clean Water Act (CWA) is to restore and maintain the chemical, physical, and biological integrity waters. Under Section 404 of the CWA, USACE has the authority to regulate activities that could discharge fill or dredge material or otherwise adversely modify wetlands or other waters of the United States. The USACE implements the federal policy embodied in Executive Order 11990, which, when implemented, is intended to result in no net loss of wetland values or function.has been finalized under three successional rules.1More recently, USACE has interpreted waters of the United States consistent with the pre-ited States Rule is founded upon and generally consistent with the pre-2015 regulatory regime, with adjustments to the regulatory text for streamlining and increasing clarity.CleanWaterActSection401The State Water Resources Control Board has authority over wetlands through Section 401 of the CWA, as well as the PorterCologne Act, California Code of Regulations Section 3831(k), and California Wetlands Conservation 1The 2015 Clean Water Rule; 2019 Repeal Rule; and 2020 Navigable Waters Protection Rule.

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Policy. The CWA requires that an applicant for a Section 404 permit (to discharge dredge or fill material into waters of the United States) first obtain certification from the appropriate State agency stating that the fill is consistent certification or waive the requirement for permits is delegated by the State Water Resources Control Board to the nine regional boards. The Los Angeles RWQCB has authority for Section 401 compliance in the Project site. A request for certification is submitted to the regional board at the same time that an application is filed with the USACE.3.2 StateCaliforniaEndangeredSpeciesActUnder the California Endangered Species Act (CESA), the California Fish and Game Commission has the responsibility of maintaining a list of threatened and endangered species. CESA prohibits the take of State-listed threatened or endangered animals and plants unless otherwise permitted pursuant to CESA. Take under CESA is hunt, pursue, catch, capture, or kill, or attempt to hunt, pursue, catch, capture, or [CFGC] Section 86). Unlike the FESA, CESA does not include harassment or harm (e.g., habitat degradation) in its definition of take. Species determined by the State of California to be candidates for listing as threatened or endangered are treated as if listed as threatened or endangered and are, therefore, protected from take. Pursuant to CESA, a State agency reviewing a project within its jurisdiction must determine whether any State-listed endangered or threatened species, or candidate species, could be potentially impacted by that project.CaliforniaDepartmentofFishandWildlifeSpecial-StatusPlantsFor this analysis, special-status plant species are defined as plants that are legally protected or that are otherwise considered sensitive by federal, State, or local resource conservation agencies. These species fall into one or more of the following categories:Listed by the federal government under FESA or the State under CESA as endangered, threatened, or rareA candidate for federal or State listing as endangered or threatenedTaxa that are biologically rare, very restricted in distribution, or declining throughout their range but not currently threatened with extirpationwith extirpation in CaliforniaTaxa closely associated with a habitat that is declining in California at a significant rate (e.g., wetlands, riparian, vernal pools, old growth forests, desert aquatic systems, native grasslands, valley shrubland habitats)Rare Plant Rank (CRPR). The CDFW system includes six rarity and endangerment ranks for categorizing plant species of concern, as follows:CRPR 1A Plants presumed extirpated in California and either rare or extinct elsewhereCRPR 1B Plants that are rare, threatened, or endangered in California and elsewhereCRPR 2A Plants presumed to be extinct in California, but more common elsewhereCRPR 2B Plants that are rare, threatened, or endangered in California, but more common elsewhere

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CRPR 3 Plants about which more information is needed (a review list)CRPR 4 Plants of limited distribution (a watch list)Plants ranked as CRPR 1A, 1B, 2A, or 2B may qualify as endangered, rare, or threatened species within the definition of CEQA Guidelines Section 15380. CDFW recommends that potential impacts to CRPR 1 and 2 species be evaluated in CEQA review documents. In general, CRPR 3 and 4 species do not meet the definition of endangered, rare, or threatened pursuant to CEQA Guidelines Section 15380, but these species may be evaluated on a case-by-case basis.CaliforniaDepartmentofFishandWildlifeSpeciesofSpecialConcernbecause declining population levels, limited ranges, and/or continuing threats have made them vulnerable to extinction. A Species of Special Concern is a species, subspecies, or distinct population of an animal native to California that currently satisfies one or more of the following (not necessarily mutually exclusive) criteria: Is extirpated from the State or, in the case of birds, is in its primary seasonal or breeding roleIs listed as threatened or endangered federally, but not by the State Meets the State definition of threatened or endangered, but has not formally been listedIs experiencing, or formerly experienced, serious noncyclical population declines or range retractions (not reversed) that, if continued or resumed, could qualify it for threatened or endangered status by the StateHas naturally small populations exhibiting high susceptibility to risk from any factor(s) that, if realized, could lead to declines that would qualify it for threatened or endangered status by the StateImpacts to Species of Special Concern are typically evaluated and mitigated within the context of an environmental impact report or other document prepared pursuant to CEQA.CaliforniaFishandGameCodeSection1600LakeandStreambedAlterationAgreementUnder Sections 16001616 of the CFGC, CDFW regulates activities that would alter the flow, bed, channel, or bank of any river, stream, or lake designated by the department in which there is at any time an existing fish or wildlife resource limit at the top of the stream or bank, or at the outer edge of the riparian vegetation, whichever is wider.CaliforniaDepartmentofFishandWildlifeWetlandsProtectionRegulationsCDFW derives its authority to oversee activities that affect wetlands from State legislation. This authority includes CFGC Sections 16001616 (lake and streambed alteration agreements), CESA (protection of State-listed species and their habitats, which could include wetlands), and the KeeneNejedly California Wetlands Preservation Act of 1976 (states a need for an affirmative and sustained public policy program directed at wetlands preservation, restoration, and enhancement). In general, CDFW asserts authority over wetlands within the State through any of the following: review and comment on USACE Section 404 permits, review and comment on CEQA documents, preservation of State-listed species, or lake and streambed alteration agreements.

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CaliforniaFishandGameCode,Section1940SensitiveNaturalCommunitiesCFGC Section 1940 requires CDFW to develop and maintain a vegetation mapping standard for the State. More than half of the vegetation communities in the State have been mapped through the Vegetation Classification and Mapping Program.Natural vegetation communities are evaluated by CDFW and are assigned global and State (S) ranks based on rarity of and threats to these vegetation communities in California. Natural communities with ranks of S1 through S3 (S1: critically imperiled; S2: imperiled; S3: vulnerable) are considered sensitive. Sensitive natural communities are communities that have a limited distribution and are often vulnerable to the environmental effects of projects. These communities may or may not contain special-status species or their habitats. For California Natural Diversity Database (CNDDB) and communities listed in the Natural Communities List with a rarity rank of S1, S2, or S3. Additionally, all vegetation associations within the alliances with ranks of S1 through S3 are considered sensitive habitats. CEQA requires that impacts to sensitive natural communities be evaluated and mitigated to the extent feasible.CaliforniaFishandGameCode,Sections3503,3503.5,3511,3513Section 3503 of the CFGC states that it is unlawful to take, possess, or needlessly destroy the nests or eggs of any bird, except as otherwise provided by this code or any regulation made pursuant thereto. Section 3503.5 protects all birds of prey (raptors) and their eggs and nests. Section 3511 states that fully protected birds or parts thereof may not be taken or possessed at any time. Section 3513 states that it is unlawful to take or possess any migratory non-game bird as designated in the MBTA.CaliforniaFishandGameCode,Section4150CFGC Section 4150 states a mammal occurring naturally in California that is not a game mammal, fully protected mammal, or fur-bearing mammal is a non-game mammal. A non-game mammal may not be taken or possessed under this code. All bat species occurring naturally in California are considered non-game mammals and are therefore prohibited from take as stated in CFGC Section 4150.PorterCologneWaterQualityControlActThe PorterCologne Water Quality Control Act established the State Water Resources Control Board and each RWQCB as the principal state agencies responsible for the protection of water quality in California. As noted under the discussion of the CWA, the Los Angeles RWQCB has regulatory authority over the Project site. The PorterState are defined in Section 13050(e) of the PorterCologne Water StateCologne Water Quality Control Act, including both point and nonpoint source dischargers. The Los Angeles RWQCB has the authority to implement water quality protection standards through the issuance of permits for discharges to waters at locations within its jurisdiction. As noted in the discussion of the CWA, the Los Angeles RWQCB is the appointed authority for Section 401 compliance in the Project site.

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CaliforniaEnvironmentalQualityActCEQA Guidelines Section 15380(b) provides that a species not listed on the federal or State list of protected species may be considered rare or endangered if the species can be shown to meet certain criteria. These criteria have been generally modeled after the definition in FESA and Chapter 1.5 of the CFGC that addresses rare or endangered plants and animals. Appendix G of the CEQA Guidelines requires a lead agency to determine whether or not a project as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the requires that a lead agency find an impact to3.3 LocalCityofThousandOaksGeneralPlanincluding community forestry, conservation, forestry, housing, land use/circulation, noise, open space, public buildings, safety, scenic highway, and social resources. Policies are set forth for the protection of these resources accordingly. The relevant General Plan Community policies related to biological resources described within the Community Forest Element (City of Thousand Oaks 2017) and Conservation Element (City of Thousand Oaks 2013) are provided below.Community Forest ElementTree ProtectionF-13.Ordinances. City staff shall keep current with research and practices relating to oak tree preservation and should disseminate such information to maintenance personnel, property owners and others responsible F-15.Where practical, the City should strive to preserve mature trees of any species when associated with a development proposal.Tree Maintenance PracticesF-16.All tree pruning on City land not being undertaken by City crews shall be approved by City staff. All pruning shall comply with International Society of Arboriculture and City maintenance standards. Pruning should not be performed solely to reduce canopy coverage except as determined appropriate by the Public Works DirectorF-20.The City shall properly dispose of removed trees and clippings, to control the spread of pests and disease and recycle tree waste to the maximum extent feasible.

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Tree Selection F-23.Plant species which are well adapted to the planting site and which will create maximum benefits with minimum problems should be planted. Proposed species should be carefully evaluated as to their likely performance in a given situation, the problems they may pose, and their ability to deliver the benefits that the planting is intended to provide. Trees should be selected using species selection and design guidelines and the planting palette from the Forestry Master Plan.F-24.Adequate space and site conditions should be provided for healthy tree growth to full maturity. City staff should evaluate proposed planting sites and suggest modifications that will provide for the best possible growing conditions for the trees. In particular, adequate unconstricted, uncompacted root room and ample air space for the trees full growth should be provided. In new developments utilities should be undergrounded outside the root zone of street trees. Narrow existing parkways should be widened wherever possible. Larger planting areas with clusters of trees should be encouraged.Planting Native TreesF-30.A variety of oaks and other species native to this area should be planted in appropriate situations. The use of oaks should be encouraged where appropriate and adequate growing conditions can be provided. The design of major streets should seek to create spaces where oaks can be used as an accent tree. Oaks should be considered in special planting areas and at important intersections and other visually important spots. Any oak or landmark tree removed by development should be replaced with trees of the same species, as determined by the size of the tree removed and pursuant to the Oak and Landmark Tree Ordinances.Site Appropriate PlantingsF-38.Environmental factors should be given equal weight with aesthetic considerations when making planting decisions. Careful use of the City's tree selection criteria and planting palette should be required to assure environmentally appropriate selections that also enhance the aesthetic character of the community.Conservation Element B. Landform FeaturesCO-6.There should be no grading in slopes over 25% natural grade and the vertical height of manufactured slopes should be no higher than 25 feet.D. Streams and CreeksCO-10.Streams and creeks should be protected as open space and maintained in as natural a state as possible, and appropriate measures taken to manage urban runoff, in order to protect the City's and other downstream communities' water quality, wildlife diversity, native vegetation, and aesthetic value. This will contribute to the regional effort to improve the quality of Calleguas Creek, Malibu Creek and Mugu Lagoon. CO-11.Degraded sections of streams and creeks should be restored or enhanced as opportunities arise and financial resources become available.

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CO-13.Use of concrete for flood control improvements in natural drainage courses should occur only when no reasonable alternatives can be found that would maintain natural hydrological and ecological functions.F. Stormwater Retention and Debris BasinsCO-15. Every effort shall be made to design and construct stormwater retention and debris basins to minimize any potentially adverse impacts to significant landform features, aquatic resources, and associated native plant and animal communities.H. Native Plant and Wildlife ResourcesCO-21. The City shall encourage the proper management, conservation and protection of native plant communities throughouting developed areas and undeveloped open space lands.CO-23.Critical wildlife habitat resources such as movement corridors, surface water impoundments, streams and springs should be given special consideration for protection, restoration or enhancement, in order to maintain biodiversity, biological productivity and ecological integrity of natural open space areas.I. Wildlife Movement CorridorsCO-26.Isolation and fragmentation of natural open space areas should be prevented wherever possible. CO-27.Since natural stream drainages often serve as important movement corridors for wildlife, they should be preserved wherever it is feasible to do so.CO-28.Urban land uses adjoining natural open space areas should be designed in a manner that is sensitive to the needs of wildlife and avoids or minimizes any potentially adverse impacts to movement corridors.J. Oak and Landmark TreesCO-29. Continue to protect oak and landmark trees and their habitat in recognition of their historic, aesthetic and environmental value to the citizens of Thousand Oaks, in particular Valley Oak habitat.L. Rare, Threatened or Endangered SpeciesCO-32. The City shall encourage and promote the conservation and protection of all rare, threatened, endangered or sensitive species listed by State and Federal agencies (United States Fish and Wildlife Service and California Department of Fish and Wildlife), the California Native Plant Society (CNPS), the County of Ventura and the City of Thousand Oaks.CityofThousandOaksOakTreesandLandmarkTreesThe City protects oak trees and landmark trees through City Ordinance. Municipal Code Section 9-4.42 providesthe Oak Tree Preservation and Protection Ordinance and Municipal Code Section 9-4.43 provides the Landmark

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Tree Preservation and Protection Ordinance. The City requires a permit for removal, pruning, or encroachment into the protected zone of any oak tree or landmark tree, which are defined below. OakTree:Any oak tree of the genus Quercus including, but not limited to, valley oak (Quercus lobata), coast live oak (Quercus agrifolia), and Inland scrub oak (Quercus berberidifolia), regardless of size. (Thousand Oaks Municipal Code, Title 9, Chapter 4, Article 42: Oak Tree Preservation and Protection)LandmarkTree:Specimens of the following species which have reached the designated maturity: California sycamore (Platanus racemosainches in diameter when measured at a point four and one-half (4 1/2') feet above the natural grade at the base of the tree; California bay (Umbellularia californica-half (4feet above the natural grade at the base of the tree; Southern California black walnut (Juglans californica) -the natural grade at the base of the tree; toyon (Heteromeles arbutifoliain diameter when measured at a point four and one-the tree. Trees with multiple trunks shall be deemed to have reached maturity if the sum of the diameters trees shall also include all designated historic trees. (Thousand Oaks Municipal Code, Title 9, Chapter 4, Article 43: Landmark Tree Preservation and Protection)ProtectedZone:A specifically defined area totally encompassing a landmark or historic tree within which work activities are strictly controlled. When depicted on a map, the outermost edge of the protected zone will appear as an irregular shaped circle that follows the contour of the dripline of the tree. Using the dripline and extend inward to the trunk of feet from the trunk of a landmark tree (both code sections).LocallyImportantSpeciesListsThe Ventura County Planning Division maintains lists of locally important plants and locally important animals (Ventura County Planning Division 2014, 2018) that are significant biological resources to be protected from incompatible land uses and development.ChecklistofVenturaCountyRarePlantsThe Checklist of Ventura County Rare Plants (Magney 2020) expands upon the Locally Important Plant List (2018) and includes plants species that are rare (5 or fewer extant populations in the country) or uncommon (6 to 10 extant populations).4 Methods4.1 Literature and Database ReviewThe location of documented sensitive vegetation communities, special-status plant species, and special-status wildlife species present near the Project site and that have potential to occur in the Biological Survey Area (BSA) this report, were identified through a query of the CNDDB for a standard nine U.S. Geological Survey 7.5-minute quadrangles surrounding the Project site (CDFW 2022a); USFWS Information for Planning and Consultation (IPaC) website (USFWS

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2022a); and the Caa). The BSA covers the entire proposed impact areas plus an additional 100-foot buffer (Figure 2, Project Site Plan). Other data reviewed included aerial photographs and relevant policy and planning documents, including the Checklist of Ventura County Rare Plants (Magney 2020), U.S. Geological Survey National Hydrography Dataset (USGS 2022), USFWS Critical Habitat Mapper (USFWS 2022b), and USFWS National Wetlands Inventory (USFWS 2022c). 4.2 Field SurveysAs shown in Table 1, Dudek biologist Melissa Blundell visited the Project site on February 8 and 17, 2021, to perform a biological site visit. During the visit Ms. Blundell walked and examined areas within the Biological Survey Area (BSA), which included the Project boundary and a 100-foot buffer. During the visit Ms. Blundell mapped vegetation communities and used a GPS unit to delineate the location and boundaries of any potentially sensitive biological resources. Heather Moine visited the site on March 21, 2022, primarily to perform an Aquatic Resources Delineation Survey and Rare Plant Survey. Supplemental vegetation and oak tree mapping was also performed, which provided supplemental information related to slight Project footprint changes and vegetation mapping refinement. Details related to the survey methods are provided below. Table 1. Summary of Biological Survey Personnel and ConditionsDateTimeSurveyTypePersonnelWeatherConditions2/8/2021 09251450 Reconnaissance MB 54.5°F63°F,20%100% cc,05 mph winds2/17/2021 08501100aReconnaissance MB58°F60°F, 0% cc,01 mph winds3/21/2022 09071720 Aquatic Resources Delineation, Rare Plant Survey, Supplemental Vegetation and Oak Tree MappingHM 59°F73°F; 20%40% cc; 14 mph wind6/24/2022 08591334 Rare Plant Survey HM68°F89°F; 0% cc;05 mph windSurveyPersonnel:MB = Melissa Blundell; HM = Heather Moine.Notes:°F = degrees Fahrenheit; cc = cloud cover; mph = miles per hour.aEstimated end time. 4.2.1 Vegetation Community and Land Cover MappingThe California Natural Communities List (CDFW 2022b) provides the current list of vegetation alliances, associations, and special stands. State and global rarity ranks are indicated for alliances and some associations; those with ranks of 1-3 are considered Sensitive. The California Natural Communities List uses the scientific name of the dominant species in that alliance as the alliance name, which is based on the Manual of California Vegetation,Second Edition (MCV2; Sawyer et al. 2009). These classification systems focus on a quantified, hierarchical approach that includes both floristic (plant species) and physiognomic (community structure and form) factors as currently observed (as opposed to predicting climax or successional stages). Nomenclature for on-site vegetation communities reflects the most current system, MCV2 and California Natural Communities List. Vegetation communities were mapped based on these sources. CNPS launched a web-based version of MCV2 in 2015 that

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provides up-to-date rankings and vegetation community descriptions (CNPS 2022b). This web-based version of MCV2 was used to provide the vegetation community rankings.Vegetation mapping was performed in the field, through interpretation of field maps with a high-quality aerialphotographic base on an Esri ArcGIS mobile application and/or delineation using a Trimble Geo XT GPS unit for all vegetation. The maximum scale of the field map was 100-scale (1-inch = 100-foot) base. The GPS data was downloaded into GIS ArcView for placement onto an aerial figure. In combination with the GPS data, GIS technicians digitized the delineated vegetation boundaries from field maps using ARCVIEW to create the vegetation community map.4.2.2 FloraDudek biologist Heather Moine, who is familiar with the target special-status plant species and general flora of the Ventura County region, performed seasonally timed focused special-status plant surveys in accordance with the CNPS Botanical Survey Guidelines (CNPS 2001); Protocols for Surveying and Evaluating Impacts to Special Status Native Plant Populations and Sensitive Natural Communities (CDFW 2018); and USFWSSurvey Guidelines (Cypher 2002). All plant species encountered during the field surveys were identified to subspecies or variety, if applicable, to determine sensitivity status. If target species were encountered, field personnel recorded data points demarcating the edge of the polygon and assessed population numbers using the Esri ArcGIS mobile application. Special-status plant species are defined as: Designated as either rare, threatened, or endangered by CDFW or the USFWS and are protected under either the California Endangered Species Act (CESA) (Fish & Game Code, § 2050 et seq.) or federally Endangered Species Act (ESA) (16 U.S.C. § 1531 et seq.), or meet the CEQA definition for endangered, rare, or threatened (Cal. Code Regs., tit. 14, § 15380(b),(d)); orCandidate species being considered or proposed for listing under these same acts; orAre of expressed concern to resource/regulatory agencies or local jurisdictions. This includes plants included on the CDFW Special Vascular Plants, Bryophytes, and Lichens List (CDFW 2022c); orAre designated as rare in Ventura County (Magney 2020) In addition to State, federal, and County special-status designations, the CNPS assigns a CRPR to designate the degree of concern for and rarity of plant taxa in California. Special-status plants are assigned to one of six CRPR categories, as follows:CRPR1A:Plants presumed extirpated in California and either rare or extinct elsewhereCRPR1B:Plants rare, threatened, or endangered in California and elsewhereCRPR2A:Plants extirpated in California, but common elsewhereCRPR2B:Plants rare, threatened, or endangered in California, but more common elsewhereCRPR3:Needs reviewCRPR4:Plants of limited distribution (a watch list)In addition to the CRPR, CNPS assigns threat categories to the lists as follows:

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0.1Seriously threatened in California (over 80% of occurrences threatened/high degree and immediacy of threat) (e.g., 1B.1 would be a plant rare, threatened, or endangered in California and elsewhere and more than 80% of the occurrences threatened or with a high degree of threat).0.2Moderately threatened in California (20% to 80% of occurrences threatened/ moderate degree and immediacy of threat)0.3Not very threatened in California (less than 20% of occurrences threatened/low degree and immediacy of threat or no current threats known)The CNPS rarely assigns a threat category of 0.1 to CRPR 4 plants because they generally have large enough populations to not be significantly threatened in California.4.2.3 FaunaDuring the reconnaissance surveys, Dudek biologist Melissa Blundell walked all areas of the BSA and all wildlife species, as detected during field surveys by sight, calls, tracks, scat, or other signs, were identified and recorded. In addition to species actually observed, expected wildlife usage of the site was determined according to known habitat preferences of regional wildlife species and knowledge of their relative distributions in the area. No trapping or focused surveys for special-status or nocturnal species was conducted. Latin and common names for vertebrate species referred to in this report follow Crother (2017) for reptiles and amphibians, American Ornithological Society (AOS 2021) for birds, Mammal Diversity Database (2021) for mammals, North American Butterfly Association (NABA 2016) or SDNHM (2002) for butterflies, and Moyle (2002) for fish. Special-status wildlife species are defined as follows: Designated as either rare, threatened, or endangered by CDFW or the USFWS and are protected under either the California Endangered Species Act (CESA) (Fish & Game Code, § 2050 et seq.) or federally Endangered Species Act (ESA) (16 U.S.C. § 1531 et seq.), or meet the CEQA definition for endangered, rare, or threatened (Cal. Code Regs., tit. 14, § 15380(b),(d)); orCalifornia Species of Special Concern (CSC), as designated by CDFW (2022d) are vertebrate species that are of concern due to suspected declining populations, limited ranges, and or continuing threats that increase their chance of extinction or extirpation in California; orMammals and birds that are fully protected (FP) species, as described in Fish and Game Code, Sections 4700 and 3511; or Birds of Conservation Concern (BCC) are bird species the USFWS considers to be of high conservation priority beyond those listed as threatened or endangered (USFWS 2021).California Fully Protected (FP) species are vertebrate species that the State identified for special protection prior to Endangered Species Act protection due to rarity or a threat of extinction. Most FP species have been State- and/or federally listed as threatened or endangered, but there are some exceptions (e.g., white-tailed kite). California Bird Species of Special Concern (Shuford and Gardali 2008). Species on the WL are not currently State- or federally listed as threatened or endangered, CSC, or FP species.Special Animals (SA) are vertebrate and invertebrate species that do not have other State designations (i.e., CSC, FP, WL) that are listed on the Special Animals List (CDFW 2022dgeneral term for all species the CDFW is currently interested in tracking through the CNDDB. CDFW

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-W 2022d).4.2.4 Aquatic Resources DelineationDuring the reconnaissance-level biological survey Dudek biologist Melissa Blundell identified areas with aquatic resources within the western portion of the BSA. As the initial step of the aquatic resources delineation, the Dudek biologist conducted a literature review of publicly available sources documenting known or potential aquatic resources within the survey area and in the local vicinity. These included National Wetland Inventory (USFWS 2022c), the National Hydrography Dataset (USGS 2022), and historical aerial images. Following the literature review, the Dudek biologist Heather Moine surveyed the BSA to delineate aquatic features and determine the extent of potentially jurisdictional aquatic resources. The aquatic resources delineation was conducted in accordance with the procedures established in the Corps of Engineers Wetlands Delineation Manual (USACE 1987) and the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (USACE 2008a). In the absence of wetlands, the limits of USACE jurisdiction in non-tidal waters, such as intermittent streams, extend to the ordinary high water mark (OHWM) (33 CFR 328.3[e]), the delineation of which follows A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States (USACE 2008b). The aquatic resources delineation also included the collection of CDFW-jurisdictional boundaries subject to Sections 16001616 of the CFGC, which extend to the top of bank or the outermost edge of riparian vegetation, whichever is greater, associated with a stream channel or waterway. Lastly, the aquatic resources delineation included an evaluation of swales.4.2.5 Survey LimitationsAside from the methods described above, no additional protocol surveys or guidelines developed by responsible or trustee agency (e.g., USFWS, USACE, CDFW) were conducted as part of this of the biological survey. The seasonal timing of the of survey precluded the observation of many wildlife species not active or evident time of year the survey occurred. Additionally, no agencies were consulted regarding aquatic resources or special-status species; therefore, the conclusions and recommendations are based on the best available information including literature, databases, and the field surveys performed.5 Results5.1 SummaryThe Project site is partially located in existing development and partially located in the adjacent open space undisturbed landscape. A total of four sensitive communities occurs within the BSA, including California brittle brush California sagebrush scrub, chamise black sage sugarbush scrub, lemonade berry California sagebrush scrub, and lemonade berry scrub (Figure 3, Vegetation Communities and Land Cover Types). Multiple oak trees (approximately 19 over 2 inches in diameter) were mapped within the BSA (Figure 4, Trees). One special-status plant species, Conejo dudleya (Dudleya parva, federally listed as threatened, California Rare Plant Rank 1B.2) approximately 25 feet uphill from the proposed debris basin (Figure 5, Biological Resources). In addition, sign for one special-status mammal, San Diego desert woodrat (N. lepida intermedia), was observed throughout the BSA (Figure 5, Biological Resources). An additional 7special-status wildlife species, not directly observed, have a moderate to high potential to occur in the undeveloped open

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spaces of the BSA. There is no USFWS critical habitat within the BSA. Potential jurisdictional aquatic features were mapped within the BSA, including an ephemeral channel, connecting swale, and v-ditch (Figure 5, Biological Resources). Although wildlife corridors and linkages are present surrounding the Hill Canyon Treatment Plant, the proposed work within open space (debris basin) is adjacent to and extends approximately 47 feet from the existing Treatment Plant fence line and unlikely to impact wildlife movement in this area. Birds protected under the Migratory Bird Treaty Act (MBTA) and/or CFGC have a potential to utilize the habitats in the undeveloped open space for nesting opportunities. 5.2 Environmental SettingThe Project site is located within a 60-acre open space parcel that contains the Treatment Plant (Figure 2, Project Site Plan). The Treatment Plant contains primary treatment facilities, secondary treatment facilities, tertiary treatment facilities, a receiving station to handle solids and fats, oil and grease, energy facilities, and other facilities. The Project site is located between two publicly owned open space systems including Wildwood Regional Parkapproximately 1,765 acres, and Conejo Canyons Open Space, approximately 1,430 acres. The City of Thousand Oaks General Plan Land Use Element designates the Project site as Institutional (City of -Public, and Institutional Lands and Facilities (P-L) (City of Thousand Oaks 2022). The land surrounding the Project site has a land use designation of Existing Parks, Golf Courses, and Open Space (City of Thousand Oaks 2018). Additionally, the land surrounding the Project site is zoned Open Space (OS) (City of Thousand Oaks 2022). SoilsHistorically mapped soils within the Project site include Hambright very rocky loam (15% to 75% slopes), generally within the naturally vegetated areas on-site, Vina loam (2% to 9% slopes) and Vina gravelly loam (2% to 9% slopes) generally within the developed Treatment Plant. Currently, the Treatment Plant is fully developed and lacks natural soils on-site. Natural soils are present along the edge of the Treatment Plant associated with the Hambright Series, consisting of shallow, well drained soils (USDA 2022a). None of the soils mapped are listed on the National Hydric Soils List by State (USDA 2022b). Soils within and surrounding the BSA are shown in the Aquatic Resources Delineation Report (ARDR; Appendix B). TerrainThe Hill Canyon Treatment Plant is an existing development within a regional open space landscape. As a result, the Treatment Plant supports a flat terrain which gently slopes (roughly 1% slope) from north to southwest, towards Arroyo Conejo Creek. The location of the proposed debris basin is located within undeveloped open space. Most of the terrain at this location is moderately sloped (roughly 15% to 20% slope) from southeast to northwest, with quickly rising hills characterized by steep terrain (roughly 70% slope) surrounding the proposed debris basin footprint. Topography contours are shown on Figure 3, Vegetation Communities and Land Cover Types. HydrologyThe Project site is located within the Ventura-San Gabriel Coastal basin Hydrologic Unit (180701) and Upper Conejo Arroyo subwatershed Hydrologic Unit (180701030104). The Upper Conejo Arroyo subwatershed covers an area of 27,665 acres (112 square kilometers) and encompasses the areas of Potrero Valley, Conejo Valley, and east toOakbrook Regional Park. Watersheds within and surrounding the BSA are shown in the ARDR (Appendix B).

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5.3 Vegetation Communities and Land Cover TypesA total of six vegetation communities and/or land cover types were mapped within the BSA (Table 2; Figure 3). All fourof the mapped vegetation communities are considered sensitive. Below are descriptions of each of the vegetation community and land cover types within the BSA.,bare soils covered with an assemblage of cyanobacteria, mosses, lichens, and/or liverworts, were also observed in specific areas within the BSA. Although these resources are ecologically valuable (e.g., soil stability, water infiltration, invasive plant species suppression) they are not specifically regulated by resources agencies and, therefore, not discussed further in this report. Photo documentation is provided as Appendix C.Table 2. Vegetation and Land Cover Types within the BSAGeneralHabitatVegetationCommunityGlobal,StateRankaCDFWSensitivebAcresNative Scrub California brittle bush California sagebrush scrub Association G3 Y 0.08Chamise Black sage Sugarbush scrubAssociation G3, S3 Y 0.11Lemonade berry scrub Alliance G3, S3 Y 0.44Lemonade berry scrub California sage scrubAssociationY 1.56Other LandCover TypesDeveloped N/A N 2.87Disturbed N/A N 0.30Total5.36Notes:BSA = Biological Survey Area.aFor alliances with State ranks of S1 to S3, all associations within them are considered highly imperiled. A question mark (?) denotes an inexact numeric rank due to insufficient samples over the full expected range of the type, but existing information points to this rank (CDFW 2022b). bSensitive based on CDFW (2022b). However, communities determined to not be sensitive may still be sensitive under local policies or provide suitable habitat for special-status plant and wildlife species. NativeScrubCaliforniaBrittleBushCaliforniaSagebrushScrubAssociationis considered vulnerable (G3) and a sensitive vegetation community by CDFW (2022b). Within this association, California brittle bush (Encelia californica) and California sagebrush (Artemisia californica) are co-dominant in the shrub layer. Some plant species associated with this association include coyotebrush (Baccharis pilularis), California buckwheat, deer weed (Acmispon glaber), laurel sumac, lemonade berry (Rhus integrifolia), sage species (Salviaspp.), and blue elderberry (Sambucus mexicana). This scrub community provides suitable cover, nesting, and foraging opportunities for commonlyoccurring wildlife species, as described under Chamise Black Sage Sugarbush Scrub Association. In addition, the federally listed coastal California gnatcatcher (Polioptila californica californica), is strongly associated with sage scrub habitats. Approximately 0.08 acre of this community was mapped near the proposed debris basin in the western portion of the BSA (Figure 3).ChamiseBlackSageSugarbushScrubAssociationis considered vulnerable (G3, S3) and a sensitive vegetation community by CDFW (2022b). Within this association, chamise (Adenostoma fasciculatum) and black sage (Salvia

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mellifera) are co-dominant in the shrub layer with sugarbush (Rhus ovata) present at lower cover. Some plant species typically associated with the alliance level include Arctostaphylos spp., California sagebrush (Artemisia californica), ceanothus (Ceanothusspp.), California buckwheat (Eriogonum fasciculatum), laurel sumac (Malosma laurina), hollyleaf redberry (Rhamnus ilicifolia), and sugar bush (Rhus ovata) (Sawyer et al. 2009). This scrub community provides suitable cover, nesting, and foraging opportunities for commonly occurring birds such as house finch (Haemorhous mexicanusCalypte anna), northern mockingbird (Mimus polyglottos), California towhee (Melozone crissalis), and wrentit (Chamaea fasciata); common mammals, such as rabbits and mice; and common reptile species, such as western fence lizard (Sceloporus occidentalis). Approximately 0.11 acres of this community was mapped near the proposed debris basin in the northeastern portion of the BSA (Figure 3).LemonadeBerryScrubAllianceis considered vulnerable (G3, S3) and a sensitive vegetation community by CDFW (2022b). Within this association, lemonade berry is dominant in the shrub layer. Some plant species associated with this alliance include California sagebrush, bush monkeyflower (Diplacus aurantiacus), California brittle bush, buckwheat species (Eriogonumspp.), toyon, sage species, and blue elderberry. Wildlife found in lemonade berry scrub is similar to that found in Chamise Black Sage Sugarbush Scrub Association. Approximately 0.44 acresof Lemonade Berry Scrub was mapped near the manhole work area and proposed debris basin in the southern and western portions of the BSA, respectively (Figure 3).LemonadeBerryScrubCaliforniaSagebrushAssociationis considered a sensitive vegetation community by CDFW (2022b). Within this association, lemonade berry and California sagebrush are co-dominate in the shrub layer. This association contains a similar composition and similar species as found with Lemonade Berry Scrub. In addition, the federally listed coastal California gnatcatcher is strongly associated with sage scrub habitats. Approximately 1.56 acres of the Lemonade Berry Scrub California Sagebrush Association was mapped near the proposed debris basin in the western portion of the BSA (Figure 3).OtherLandCoverTypesDevelopedareas are not listed in CDFW (2022b) and not considered sensitive. Developed land refer to areas that have been constructed upon or otherwise physically altered to the extent that native vegetation communities are not supported. Developed areas are characterized by permanent or semi-permanent structures, hardscapes, and landscaped areas that require irrigation. Within the BSA, approximately 2.87 acres mapped as developed areas include the entire Hill Canyon Treatment Plant, including buildings, landscaping, access roads, and parking areas. Most of the developed areas in the BSA lack any vegetation to provide cover, feeding, or nesting opportunities for wildlife species. Limited ornamental landscaping may provide some temporary cover or nesting opportunities for common urban-adapted bird and reptile species. Disturbedareas are not listed in CDFW (2022b) and is not considered sensitive. Disturbed habitat refers to areas where soils have been recently or repeatedly disturbed by grading, compaction, or clearing of vegetation. Structures are typically not present within disturbed habitats, and these areas provide relatively low value for most plant and wildlife species. Within the BSA, approximately 0.30 acres of disturbed habitat occurs adjacent to the existing Treatment Plant near the proposed debris basin; along an access road near the manhole work area; and near existing equipment adjacent to the manhole work area (Figure 3). Disturbed areas provide very limited to no cover for birds, reptiles, and small mammals as they traverse between more suitable habitats, and very minimal to no food resources.

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5.4 City-Regulated TreesDuring the reconnaissance survey, approximately 19 oak tree species (Quercussp.), great than 2 inches in diameter, were documented within the BSA (Figure 4, City-Regulated Trees). The majority of the oak trees were mapped near or within the proposed debris basin and pipeline work areas. Two additional oak trees occurred near, but outside the proposed footprint, of the manhole and inlet work area. Table 3 provides a summary of the City-regulated tree species encountered during the reconnaissance survey. Table 3. Summary of City-Regulated Tree Species within the BSATreeNo.TreeSpeciesApproximateDiameter(Inches)a1 Coast/interior live oak 18, 17.53 Coast/interior live oak 354 Coast/interior live oak 20.8, 37.5 fused5 Coast/interior live oak 16.26 Coast/interior live oak 7, 4, 57 Coast/interior live oak 148 Coast/interior live oak 9.3, 119 California black oak > 210 Coast/interior live oak 28.711 Coast/interior live oak 3912 Coast/interior live oak 8.813 Coast/interior live oak 814 Coast/interior live oak 14.5, 12.9, 1315 Coast/interior live oak 1716 Coast/interior live oak 7.117 Coast/interior live oak 8.118 Coast/interior live oak 8.819 Coast/interior live oak 8.720 Coast/interior live oak 26.7Notes:BSA = Biological Survey Area.aMultiple measurements provided for multi-branched individuals. Measured at 4.5 feet above base of tree.5.5 Common Plant and Wildlife Species A total of 112 plant species were documented, as listed in Appendix D. In all, 72 (64%) were native and 40 (36%) were non-native. One special-status plant species, Conejo dudleya (Dudleya parva), was observed and is discussed further below. A total of 22 common wildlife species were observed during the site visit, including 1 reptile, 19 birds, and 2 mammals (Appendix D). Woodrat middens (presumably from the desert woodrat [Neotoma lepidassp. intermedia], a CDFW Species of Special Concern [SSC]) were observed throughout the natural areas, and are described further below. Although ground squirrels were observed, areas of significant burrowing were not. In addition, one bird species, oak titmouse (Baeolophus inornatus), a USFWS Bird of Conservation Concern, was observed. No fish or amphibians were observed during the field survey and the BSA lacks suitable aquatic habitat to support these species.

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5.6 Special-Status Plants and Wildlife5.6.1 Special-Status Plant SpeciesThe literature and database views resulted in 60 special-status plant species that have been documented in the nine U.S. Geological Survey 7.5-minute quadrangles surrounding the Project site. analysis and rare plant surveys performed in 2022, 1 of the 60 special-status plant species, Conejo dudleya, was observed during the 2022 seasonally timed rare plant surveys. Figure 5, Biological Resources, displays the location of the observed Conejo dudleya. Table 4 provides a description of this special-status plant species. The remaining 59 species are considered to have a low potential or not expected to occur and are described in Appendix E. Several species are considered to have low to no potential to occur primarily due to the lack of observations within the BSA during the 2022 focused surveys. The CNDDB report form for Conejo dudleyaobservation is provided as Appendix F. Conejo dudleya is further discussed in Section 6, Project Impacts, due to the potential direct, indirect, or cumulative impacts to occur to this species. No further analysis of special-status plant species described in Appendix E is included, because no direct, indirect, or cumulative impacts are expected.

Notes:aThe federal and State status of species is based on the Special Vascular Plants, Bryophytes, and Lichens List (CDFW 2022c). StatusDesignationsFT: Federally listed as threatenedCaliforniaRarePlantRank:CRPR 1B: Plants rare, threatened, or endangered in California and elsewhereCRPR Threat Designations:0.2 Moderately threatened in California (20%80% occurrences threatened/moderate degree and immediacy of threat) Table 4. Special-Status Plant Species Observed within the Biological Survey AreaScientificNameCommonNameStatus(Federal/State/CRPR)aPrimaryHabitatAssociations/LifeForm/BloomingPeriod/ElevationRange(feet)PotentialtoOccurintheBiologicalSurveyArea(BSA)Dudleya parvaConejo dudleyaFT/None/1B.2Coastal scrub, Valleyand foothill grassland; Clay (sometimes), Gravelly (sometimes), Rocky (sometimes), Volcanic (sometimes)/perennial herb/MayJune/1951,475Observed.This species was observed during 2022 rare plant surveys. Approximately 151 individuals were observed along the southeastern edge of the BSA, with the closest observations to impact areas about 25 feet uphill from the proposed debris basin. Suitable coastal scrub habitat and rocky, gravelly substrate are present to support this specieswithin the BSA.Regionally, there are two occurrences observed in 2010 that are both mapped approximately 0.6 miles southeast of the Project site (CDFW 2022a). In addition, there are numerous occurrences within 5 miles of the Project site (CDFW 2022a).

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5.6.2 Special-Status Wildlife SpeciesThe literature and database views resulted in 57 special-status wildlife species that have been documented in the nine U.S. Geological Survey 7.5-analysis, 6 of the 57 special-status wildlife species are expected to have a moderate to high potential to occur. In addition, direct sign (middens) for desert woodrat (Neotomasp.) was observed within the BSA (Figure 5). Presumably these middens were established by the San Diego desert woodrat (N. lepida intermedia). Table 5 provides a description of these 7 special-status species. The remaining 50 species with a low potential or not expected to occur are described in Appendix G, which includes the species potential to occur based on documented occurrences and site conditions.

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Table 5. Special-Status Wildlife Species Observed or with a Moderate to High Potential to OccurSpeciesNameCommonNameStatus(Federal/State)aHabitatPotentialtoOccurintheBiologicalSurveyArea(BSA)ReptilesAnniella spp.California legless lizardNone/SSCCoastal dunes, stabilized dunes, beaches, dry washes, valleyfoothill, chaparral, and scrubs; pine, oak, and riparian woodlands; associated with sparse vegetation and moist sandy or loose, loamy soilsModeratepotentialto occur. Sandy and loose loamy soils present within the BSA may be suitable to support this species. The nearest CNDDB occurrence was documented in 2014 approximately 2.7 miles north of the BSA, where the species was observed in the leaf litter of an avocado orchard across the street from a sandy slope dominated by coastal sage scrub (CDFW 2022a). Aspidoscelis tigris stejnegeriSan Diegan tiger whiptailNone/SSCHot and dry areas with sparse foliage, including chaparral, woodland, and riparian areas.Moderatepotentialto occur. Although the nearest CNDDB occurrence is from 2017 and mapped approximately 6.0 miles east of the BSA (CDFW 2022a), vegetated portions of the BSA are contiguous with a lager open space and contain the open scrub and sandy and/or gravel bottom habitats preferred by this species. Phrynosoma blainvilliiBlainville's horned lizardNone/SSC Open areas of sandy soil in valleys, foothills, and semi-arid mountains including coastal scrub, chaparral, valleyfoothill hardwood, conifer, riparian, pinecypress, juniper, and annual grassland habitatsModeratepotential to occur. Sandy and loose loamy soils present within the BSA may be suitable to support this species. In addition, the nearest CNDDB occurrence was observed in an agricultural field set for development in 2007 and mapped approximately 2.7 miles northwest of the BSA(CDFW 2022a).BirdsAccipiter cooperii (nesting)Cooper's hawkNone/WL Nests and forages in dense stands of live oak, riparian woodlands, or other woodland habitats often near waterModeratepotential to nest. The oak trees within the BSA provide suitable nesting substrates for this species. In addition, this species is regularly observed within the surrounding open space, including Wildwood Regional Park (eBird 2022), where there are abundant prey resources available forthis species.

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Table 5. Special-Status Wildlife Species Observed or with a Moderate to High Potential to OccurSpeciesNameCommonNameStatus(Federal/State)aHabitatPotentialtoOccurintheBiologicalSurveyArea(BSA)Aimophila ruficeps canescensSouthern California rufous-crowned sparrowNone/WLNests and forages in open coastal scrub and chaparral with low cover of scattered scrub interspersed with rocky andgrassy patchesModeratepotential to occur. Suitable scrub and chaparral habitat is present to support this species. In addition, this species is regularly observed within the surrounding open space, including Wildwood Regional Park (eBird 2022), where there are abundant prey resources available forthis species. Polioptila californica californicacoastal California gnatcatcherFT, BCC/SSCNests and forages in various sage scrub communities, often dominated by California sagebrush and buckwheat; generally avoids nesting in areas with a slope of greater than 40%; majority of nesting at less than 1,000 feet above mean sea levelModeratepotential to occur. Suitable coastal sage scrub habitat dominated by California sagebrush is present within and adjacent to the BSA to support this species. In addition, the nearest CNDDB occurrence was observed in coastal sage scrub adjacent to a walking trail in 2016 and mapped approximately 0.6 miles southwest of the BSA (CDFW 2022a); in 2019 approximately 0.9 miles southwest of the BSA (USFWS 2022d); and there are multiple and regularly occurring observations of this species in the adjacent Wildwood Regional Park (eBird 2022). MammalsNeotoma lepida intermediaSan Diego desert woodratNone/SSC Coastal scrub, desert scrub, chaparral, cacti, rocky areasObserved. Multiple woodrat middens (Neotomasp.) were documented throughout the BSA during field surveys. The BSA contains suitable coastal scrub and rocky outcrop habitat. In addition, the nearest documentedoccurrence was observed on a rocky outcrop in 2016 and is mapped approximately 4.3 miles south of the BSA (CDFW 2022a).Notes:aThe federal and State status of species is based on the Special Animals List (CDFW 2022d). StatusAbbreviationsFT: Federally listed as threatenedBCC: U.S. Fish and Wildlife Service Bird of Conservation ConcernSSC: California Species of Special ConcernWL: California Watch List Species

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5.7 Critical HabitatA query of the IPaC (USFWS 2022a) and review of the critical habitat mapper (USFWS 2022b) indicated that there is Lyons pentachaeta (Pentachaeta lyonii) critical habitat within 5 miles of the Project site; however, no critical habitat is within the Project site (Figure 6, USFWS Critical Habitat).5.8 Jurisdictional Aquatic ResourcesAs described in the ARDR (Appendix B) and shown on Figure 5, potential jurisdictional aquatic features mapped include a concrete v-ditch, connecting swale, and an ephemeral channel. As described in the ARDR, of these features, only the ephemeral channel is anticipated to require additional permits pursuant to the Porter-Cologne Water Quality Control Act and CFGC for impacts to the channel. However, as recommended in the ARDR, written concurrence from the resource agencies (RWQCB, CDFW, and USACE) on the jurisdictional status for both features is highly recommended. ConcreteV-DitchThe concrete v-ditch is an existing stormwater control feature within the Hill Canyon Treatment Plant that directs flows to drain-inlets along the v-ditch (Figure 5). The drain inlets are regularly maintained by Hill Canyon Treatment Plant staff as part of storm preparedness activities. These inlets capture storm flows and drain them to the sludge drying beds as part of the stormwater capture program (Capron 2017; City of Thousand Oaks 2019). Since the flows associated with the v-ditch are currently subject to the adopted Waste Discharge Requirements and National Pollutant Discharge Elimination System permits for the Hill Canyon Treatment Plant (Order No. R4-2019-0137, NPDES No. CA0056294), compliance with this existing permit should apply to this feature and further permits are not anticipated to be necessary from the RWQCB. We understand the Hill Canyon Treatment Plant had previously attained status as a zero-discharge facility. An Industrial General Permit Notice of Non-Applicability was previously granted by the RWQCB, and the City is petitioning to retain this status with site modifications to re-route off-site flows from the natural canyon directly to Arroyo Conejo Creek (Capron 2017; City of Thousand Oaks 2019). In addition, the concrete v-ditch is unlikely to be jurisdictional to USACE under the Clean Water Act, as the feature is ephemeral and current flows lack a connection with a traditional navigable water. Similarly, the feature lacks a bed and bank often associated with CDFW jurisdictional rivers, stream, or lakes. EphemeralChannelA narrow ephemeral channel is present in the BSA within and adjacent to the proposed debris basin (Figure 5). The channel is located within the natural canyon and extends to the existing concrete v-ditch. This channel is characterized by an OHWM and a bed, with portions of the channel containing a bank. Blue elderberry (Sambucus mexicana) is present along this feature providing limited riparian habitat. In addition, a short 12-foot swale connects the feature in the eastern portion of the BSA. These features are anticipated to be jurisdictional to CDFW and the RWQCB. Given that the feature is ephemeral and lacks connection with a traditional navigable water, it is unlikely to be jurisdictional to USACE.

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5.9 Wildlife Corridors and Habitat LinkagesWildlife corridors are linear features that connect large patches of natural open space and provide avenues for dispersal or migration of animals and dispersal of plants (e.g., via wildlife vectors). Wildlife corridors contribute to population viability by ensuring continual exchange of genes between populations, which helps maintain genetic diversity. Habitat linkages are small patches that join larger blocks of habitat and help reduce the adverse effects of habitat fragmentation. They serve as connections between habitat patches and help reduce the adverse effects of habitat fragmentation. Although individual animals may not move through a habitat linkage, the linkage is a potential route for gene flow and long-term dispersal. Habitat linkages may serve both as habitat and avenues of gene flow for small animals such as reptiles, amphibians, and rodents. Habitat linkages may be represented by continuous -stones for dispersal and movement (especially for birds and flying insects). Wildlife corridors and habitat linkages provide avenues for dispersal or migration of animals that also contribute to population viability in several ways, including the following:Ensuring continual exchange of genes between populations to aid in maintaining genetic diversityProviding habitat for some speciesProviding access to adjacent habitat areas representing additional territory for foraging and matingAllowing for a greater carrying capacity Providing routes for colonization of habitat lands following local population extinctions or habitat recovery from ecological catastrophesThe Project is located at the interface of existing development (Treatment Plant) and undeveloped open space. The Treatment Plant is located between two publicly owned open space systems including Wildwood Regional Parkapproximately 1,765 acres, and Conejo Canyons Open Space, approximately 1,430 acres. In addition, regional habitat connectivity and wildlife corridors are mapped in natural areas surrounding the plant (SCWildlands 2008;CDFW 2022e; Ventura County 2022). However, the existing Treatment Plant is fully enclosed with a chain-linked fence. Therefore, the Treatment Plant provides no opportunities for wildlife movement and Project activities within the plant are not expected to affect wildlife corridors. Although the proposed debris basin is located within undeveloped open space, the location and proposed disturbed areas are adjacent to the existing fenced facility (extending out to approximately 47 feet southeast of the fence line). With abundant surrounding open spaces and opportunities for movement, the construction of the debris basin at this location is not anticipated to impede, interfere, or significantly affect wildlife movement, corridors, or linkages. 6 Project Impacts6.1 Definition of ImpactsPermanentdirectimpactstypically refer to 100% permanent loss of a biological resource. It is also often referred to Projectmay include brush management zones or FMZs. Basically, wherever the existing vegetation or land cover would be permanently affected, it is considered to be a permanent direct impact.

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Directtemporaryimpactstypically refer to short-term removal of a biological resource where the resource is expected to fully recover its function upon completion of the Project. Areas subject to temporary disturbance may include slope remediation sites, construction access roads, staging areas, stockpiles, mowing, dredging, etc. Such sites would not have permanent structures. However, it should be noted that not all natural vegetation communities fully recover following disturbance (e.g., oak woodland).Indirectimpactsare reasonably foreseeable effects caused by Project implementation on remaining or adjacent biological resources outside the direct construction disturbance zone. Indirect impacts may affect areas within the defined Project Area but outside the construction disturbance zone, including open space and areas outside the Project Area, such as downstream effects. Indirect impacts include short-term effects immediately related to construction activities and long-term or chronic effects related to the human occupation of developed areas (i.e., development-related long-term effects). Project short-term indirect impacts include fugitive dust, changes inhydrology, runoff, sedimentation, and chemical pollutants. Fugitive dust can decrease the vigor and productivity of vegetation through light, penetration, photosynthesis, respiration, transpiration, increased penetration of phytotoxic gaseous pollutants, and increased incidence of pests and diseases. In most cases, indirect effects are not quantified, but in some cases quantification might be included, such as total dissolved solids released to downstream areas or using a noise contour to quantify indirect impacts to nesting birds. Cumulativeimpactsrefer to the combined environmental effects of the proposed Project and other relevant projects. In some cases, the impact from a single project may not be significant, but when combined with other projects, the cumulative impact may be significant. This section describes the approach to analyzing cumulative effects, including defining the cumulative effects study area, the method for including other projects (i.e., the list vs. the plan method). 6.2 Explanation of Findings of SignificanceCEQA Guidelines Section 15065(a) lists impacts that are helpful in defining whether a project may have a significant effect on the environment. Mandatory findings of significance occur when there is substantial evidence that a project could (1) substantially degrade the quality of the environment, (2) substantially reduce the habitat of a fish or wildlife species, (3) cause a fish or wildlife population to drop below self-sustaining levels, (4) threaten to eliminate a plant or animal community, or (5) reduce the number or restrict the range of a rare or endangered plant or animal.The following are the significance thresholds for biological resources provided in the CEQA Appendix G environmental checklist, which states that a project could potentially have a significant effect if it:Has a substantial adverse effect, either directly or through habitat modifications, on any species identified as being a candidate, sensitive, or special-status species in local or regional plans, policies, or regulations, or by CDFW or USFWSHas a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, or regulations, or by CDFW or USFWSHas a substantial adverse effect on State or federally protected wetlands (including, but not limited to marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other meansInterferes substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impedes the use of native wildlife nursery sitesConflicts with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance

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Conflicts with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or State habitat conservation plan.6.3 Impacts to Vegetation Communities andLand CoversAs discussed in Section 5.3, Vegetation Communities and Land Cover Types, four sensitive vegetation communities (California brittle brush California sagebrush scrub, chamise black sage sugarbush scrub, lemonade berry, lemonade berry California sagebrush scrub) were identified within the BSA. Of these four sensitive communities permanent impacts will occur to 0.03 acre of lemonade berry scrub and 0.06 acre of lemonade berry scrub California sage brush scrub. DirectImpactsAs shown in Figure 7, Impacts to Biological Resources, and Table 6, the Project will permanently impact approximately 0.09 acre of sensitive vegetation communities. In addition, inadvertent direct (temporary) impacts to sensitive communities may occur if construction activities accidentally trim, clear, trample, or grade sensitive vegetationcommunities outside of the proposed work areas (i.e., permanent impact areas). Impacts to sensitive vegetationcommunities is considered potentially significant. However, implementation of MitigationMeasure(MM)BIO-1(Habitat Mitigation and Monitoring Plan), MM-BIO-2(Worker Education and Awareness Program), MM-BIO-3(Delimiting Construction Area), and MM-BIO-4(Biological Monitoring) would reduce potential direct impacts to sensitive vegetation communities to less than significant.IndirectImpactsThere is potential for indirect impacts to sensitive vegetation communities adjacent to and outside of the proposed work areas. Indirect impacts may occur as the result of construction site run-off, accidental pollutant/chemical spills, discharge of materials from the use of concrete, oil/gas, water runoff, erosion, and fugitive dust. Impacts to sensitive vegetation communities is considered potentially significant. Therefore, MM-BIO-2, MM-BIO-3, MM-BIO-4, and MM-BIO-5(Erosion and Sediment Control Plan) are recommended to avoid potential indirect impacts to sensitive vegetation communities. Table 6. Proposed Impacts to Vegetation and Land Cover Types within the BSAGeneralHabitatVegetationCommunityGlobal,StateRankaCDFWSensitivebPermanentImpactsacres(squarefeet)Native Scrub California brittle bush California sagebrush scrub Association G3 Y NoneChamise Black sage Sugarbush scrub Association G3, S3 YNoneLemonade berry scrub Alliance G3, S3 Y 0.03Lemonade berry scrub California sage scrub AssociationY0.06Other Land Cover TypesDeveloped N/A N 0.19Disturbed N/A N 0.06Total0.35

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Notes:N/A = not applicable, BSA = Biological Survey Area.aFor alliances with State ranks of S1 to S3, all associations within them are considered highly imperiled. A question mark (?) denotes an inexact numeric rank due to insufficient samples over the full expected range of the type, but existing information points to this rank (CDFW 2022b). bSensitive based on CDFW (2022b). However, communities determined to not be sensitive may still be sensitive under local policies or provide suitable habitat for special-status plant and wildlife species. 6.4 City-Regulated TreesAs discussed in Section 5.4, City-Regulated Trees, approximately 19 oak trees over 2 inches in diameter were identified within the BSA. The City protects oak trees and landmark trees through City Ordinance. Municipal Code Section 9-4.42 provides the Oak Tree Preservation and Protection Ordinance and Municipal Code Section 9-4.43 provides the Landmark Tree Preservation and Protection Ordinance. In addition, as mentioned in Section 2.4, Project Construction and Scheduling, all oak tree work shall conform and abide by the provisions of the Oak Tree Ordinance, Title 5, Chapter 14 of the Thousand Oaks Municipal Code, and the Oak Tree Preservation and Protection Guidelines Res. No. 2010-014. The City requires a permit for removal, pruning, or encroachment into the protected zone of any oak tree or landmark tree, which are defined below. DirectImpactsAs shown in Figure 7, Impacts to Biological Resources, the proposed work areas will be located outside the tree trunk base of mapped oak trees. However, the Project will encroach within the City established oak tree protected zone requirements (i.e., within 5 feet of the oak tree canopy or within 15 feet from the base of the tree trunk) for an estimated 8 trees and overlapping with 0.04 acre (11%, 1,640 square feet) of the 0.33 acre mapped overhead canopy, suggesting these oak trees may experience injury or mortality of the root systems. In addition, inadvertent direct (temporary) impacts to sensitive communities may occur if construction activities accidentally trim oak trees outside of the proposed work areas (i.e., permanent impact areas). Impacts to oak trees is considered potentially significant. However, implementation of MM-BIO-2(Worker Education and Awareness Program), MM-BIO-3(Delimiting Construction Area), MM-BIO-4(Biological Monitoring), and MM-BIO-6(Protected Tree Removal, Replacement, and Protective Measures) would reduce potential direct impacts to individual oak trees to less than significant.IndirectImpactsThere is potential for indirect impacts to oak trees adjacent to and outside of the proposed work areas. Indirect impacts may occur as the result of construction site run-off, accidental pollutant/chemical spills, discharge of materials from the use of concrete, oil/gas, water runoff, erosion, and fugitive dust. Impacts to oak trees is considered potentially significant. Therefore, MM-BIO-2, MM-BIO-3, MM-BIO-4, and MMBIO-5(Erosion and Sediment Control Plan) are recommended to avoid potential indirect impacts to oak trees.6.5 Impacts to Special-Status Plant SpeciesAs discussed in Section 5.6.1, Special-Status Plant Species, one special-status plant species, Conejo dudleya, was observed within the BSA. Approximately 151 individuals were observed along the southeastern edge of the BSA, with the closest observations to impact areas about 25 feet uphill from the proposed debris basin.

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DirectImpactsAs shown in Figure 7, the proposed work areas will be located outside the mapped Conejo dudleya population. However, inadvertent direct (temporary) impacts to Conejo dudleya may occur if construction activities accidentally trim, clear, trample, or grade individuals outside of the proposed work areas (i.e., permanent impact areas). Impacts to this special-status species is considered potentially significant. However, implementation of MM-BIO-2(Worker Education and Awareness Program), MM-BIO-3(Delimiting Construction Area), and MM-BIO-4(Biological Monitoring) would reduce potential direct impacts to this species to less than significant.IndirectImpactsThere is potential for indirect impacts to Conejo dudleya adjacent to and outside of the proposed work areas. Due to the species location uphill from work areas, indirect impacts may occur as the result of fugitive dust. Impacts to this species is considered potentially significant. Therefore, MMBIO-5(Erosion and Sediment Control Plan) isrecommended to avoid potential indirect impacts to this species.6.6 Impacts to Special-Status Wildlife SpeciesAs discussed in Section 5.6.2, Special-Status Wildlife Species, there is a potential for seven special-status wildlife species to occur within the BSA. These include three reptiles (California legless lizard [Anniellaspp.], San Diegan tiger whiptail [Aspidoscelis tigris stejnegeri], and [Phrynosoma blainvillii]hawk [Accipiter cooperii], Southern California rufous-crowned sparrow [Aimophila ruficeps canescens], and coastal California gnatcatcher), and one mammal (San Diego desert woodrat).6.6.1 ReptilesDirectImpactsProject activities could result in direct permanent impacts to the California legless lizard, San Diegan tiger whiptail, and where activities occur in the natural undeveloped portions of the site. The Project would result in permanent direct impacts to 0.09 acres of suitable on-site scrub habitat for these species. However, these impacts would be less than significant due to the abundant suitable habitat present in the vicinity of the Project site. Individuals are cryptic and slow moving on the surface or are otherwise underground, and therefore, are highly vulnerable to injury and mortality during construction. Therefore, direct permanent impacts may result in mortality of these species, from heavy construction equipment, vehicle collisions, inadvertently stepping on individuals, or crushing occupied burrows. Impacts to special-status reptile individuals is considered potentially significant. However, implementation of MM-BIO-2(Worker Education and Awareness Program), MM-BIO-3(Delimiting Construction Area), MM-BIO-4(Biological Monitoring), and MM-BIO-7(Reptile Pre-Construction Survey) would reduce potential direct impacts to these species to less than significant.IndirectImpactsThere is potential for indirect impacts to reptiles occurring adjacent to and outside of the proposed work areas. Indirect impacts may occur as the result of construction site run-off, accidental pollutant/chemical spills, discharge of materials from the use of concrete, oil/gas, water runoff, erosion, and fugitive dust. Impacts to these species is

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considered potentially significant. Therefore, MM-BIO-2, MM-BIO-3, MM-BIO-4, and MMBIO-5(Erosion and Pollution Control Plan) are recommended to avoid potential indirect impacts to these species.6.6.2 Special-Status Avian SpeciesSouthern California rufous-crowned sparrow, and coastal California gnatcatcher have a potential to occur in the undeveloped open space areas throughout the BSA for perching, nesting, or foraging. The abundant prey (bird and rodent) populations in the adjacent open space would provide hunting opportunities and oak trees would greater open space would provide feeding, cover, and nesting opportunities for southern California rufous-crowned sparrow. Coastal California gnatcatcher are strongly associate with sage scrub habitats, which are present throughout the BSA. These habitats would provide feeding, cover, and nesting opportunities for this species, which is federally listed as threatened. DirectImpactsDue to the expansive open space surrounding the site, direct permanent impacts to 0.09 acres of scrub habitat (for foraging) and an estimated 8 individual oak trees (associated with 0.04 acre of overhead canopy) are not anticipated to adversely affect habitat for this species. The loss of nesting and foraging habitat would be less than significant because of the expansive habitat available surrounding the site. Individual adults are unlikely to be directly killed or injured during construction activities because they are highly mobileand would likely leave the area during construction. However, should any individuals nest within or adjacent to the Project site, nesting could be disrupted (resulting in nest abandonment or reduced reproductive success) if construction occurs during the breeding season. In addition, should this species nest on site, nests, eggs, and young could be directly affected by oak tree vegetation clearing and grading. Any direct impacts to individuals, nests, eggs, or young, including nest abandonment, of this special-status species as a result of construction activities would be significant. Implementation of MM-BIO-8(Pre-Construction Nesting Bird Surveys) would reduce potential direct impacts to this species to less than significant.IndirectImpactsShort-term indirect impacts during construction that involve loud noise disruptions during the nesting season have the potential to impact nesting individuals on and adjacent to the existing facilities to the degree that the hawk areconsidered potentially significant. Implementation of MM-BIO-8would reduce potential indirect impacts to this species to less than significant.

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Southern California Rufous-Crowned SparrowDirectImpactsDue to the expansive open space surrounding the site, direct permanent impacts to 0.09 acres of scrub habitat (for foraging) are not anticipated to adversely affect habitat for this species. The loss of nesting and foraging habitat would be less than significant because of the expansive habitat available surrounding the site. Individual adults are unlikely to be directly killed or injured during construction activities because they are highly mobileand would likely leave the area during construction. However, should any individuals nest within or adjacent to the Project site, nesting could be disrupted (resulting in nest abandonment or reduced reproductive success) if construction occurs during the breeding season. In addition, should this species nest on site, nests, eggs, and young could be directly affected by scrub vegetation clearing and grading. Any direct impacts to individuals, nests, eggs, or young, including nest abandonment, of this special-status species as a result of construction activities would be significant. Implementation of MM-BIO-8(Pre-Construction Nesting Bird Surveys) would reduce potential direct impacts to this species to less than significant.IndirectImpactsShort-term indirect impacts during construction that involve loud noise disruptions during the nesting season have the potential to impact nesting individuals on and adjacent to the existing facilities to the degree that the nests may be abandoned, resulting in a direct loss of an active nest. Impacts to nesting Southern California rufous-crowned sparrow are considered potentially significant. Implementation of MM-BIO-8would reduce potential indirect impacts to this species to less than significant.Coastal California GnatcatcherDirectImpactsDue to the expansive open space surrounding the site, direct permanent impacts to 0.09 acres of sage scrub associated habitats are not anticipated to adversely affect habitat for this species. The loss of nesting and foraging habitat would be less than significant because of the expansive habitat available surrounding the site. Individual adults are unlikely to be directly killed or injured during construction activities because they are highly mobileand would likely leave the area during construction. However, take in the form of harassment may occur if any individuals are present during construction activities. Additionally, take in the form of harm or mortality may occur if any individuals nest within or adjacent to the Project site. Nesting could be disrupted (resulting in nest abandonment or reduced reproductive success) if construction occurs during the breeding season. In addition, should this species nest on site, nests, eggs, and young could be directly affected by sage scrub vegetation clearing and grading. Any direct impacts to individuals, nests, eggs, or young, including nest abandonment, of this special-status species as a result of construction activities would be significant. Implementation of MM-BIO-4(Biological Monitoring), MM-BIO-8(Pre-Construction Nesting Bird Surveys), and MM-BIO-9(Coastal California Gnatcatcher Surveys and Avoidance) would reduce potential direct impacts to this species to less than significant.

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / BIOLOGICAL RESOURCES ASSESSMENT REPORT 1276732MARCH 2023
IndirectImpactsShort-term indirect impacts during construction that involve loud noise disruptions during the nesting season have the potential to impact nesting individuals on and adjacent to the existing facilities to the degree that the nests may be abandoned, resulting in a direct loss of an active nest. Impacts to nesting coastal California gnatcatcher are considered potentially significant. Implementation of MM-BIO-8would reduce potential indirect impacts to this species to less than significant.6.6.3 Birds Protected under the MBTA and/or CFGCRemoval of trees and vegetation associated with construction of the Project have the potential to disturb nesting birds on and adjacent to the site, to the degree that the nests may be abandoned, resulting in a direct loss of an active bird nest. Bird nests with eggs or young of all migratory bird species are protected under the MBTA and the CFGC. Active bird nests or nests with eggs or young of all native bird species are protected under the MBTA and the CFGC. Loss of active nests as a result of construction-related activities would conflict with these regulations. DirectImpactsRemoval of vegetation associated with construction activities have the potential to disturb nesting birds on and adjacent to the site, to the degree that the nests may be abandoned, resulting in a direct loss of an active bird nest. Individual adults are unlikely to be directly killed or injured during construction activities because they are highly mobileand would likely leave the area during construction. However, should any individuals nest within or adjacent to the Project site, nesting could be disrupted (resulting in nest abandonment or reduced reproductive success) if construction occurs during the breeding season. In addition, should these species nest on site, nests, eggs, and young could be directly affected by scrub vegetation clearing and grading. Any direct impacts to individuals, nests, eggs, or young, including nest abandonment, of bird species protected under the MBTA and/or CFGC as a result of construction activities would be significant. Implementation of MM-BIO-8(Pre-Construction Nesting Bird Surveys) would reduce potential direct impacts to these species to less than significant.IndirectImpactsShort-term indirect impacts during construction that involve loud noise disruptions during the nesting season have the potential to impact nesting individuals on and adjacent to the existing facilities to the degree that the nests may be abandoned, resulting in a direct loss of an active nest. Impacts to nesting birds protected under the MBTA and/or CFGC are considered potentially significant. Implementation of MM-BIO-8would reduce potential indirect impacts to these species to less than significant.6.7 Impacts to Critical HabitatNo federally designated critical habitat occurs within the BSA or the Project site. Therefore, no impacts to critical habitat would occur as a result of the Project. 6.8 Impacts to Jurisdictional Aquatic ResourcesAs discussed in Section 5.8, Jurisdictional Aquatic Resources, and the ARDR (Appendix B), non-wetland waters are present within the BSA and Project impact area.

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / BIOLOGICAL RESOURCES ASSESSMENT REPORT 1276733MARCH 2023
DirectImpactsAs shown in Figure 7, Impacts to Biological Resources, the Project will permanently impact approximately 0.01 acres (315 square feet; 105 linear feet) of non-wetland waters of the State, including up to mapped top of bank; and 0.01 acre (332 square feet) of riparian would be directly (permanently) impacted from construction of the debris basin. In addition, inadvertent direct (temporary) impacts to jurisdictional waters may occur if construction activities accidentally grade or remove soils outside of the proposed work aeras. Direct impacts to jurisdictional aquatic resources are considered potentially significant. However, implementation of MM-BIO-1(Habitat Mitigation and Monitoring Plan), MM-BIO-2(Worker Education and Awareness Program), MM-BIO-3(Delimiting Construction Area),and MM-BIO-4(Biological Monitoring) would reduce potential direct impacts to jurisdictional aquatic resources to less than significant.IndirectImpactsThere is potential for indirect impacts to jurisdictional aquatic resources adjacent to and outside of the proposed work areas. Indirect impacts may occur as the result of construction site runoff, accidental pollutant/chemical spills,discharge of materials from the use of concrete, oil/gas, water runoff, erosion, and fugitive dust. Impacts to jurisdictional aquatic resources are considered potentially significant. Therefore, MM-BIO-2,MM-BIO-3, MM-BIO-4, and MM-BIO-5(Erosion and Pollution Control Plan) are recommended to avoid potential indirect impacts to jurisdictional aquatic resources. 6.9 Impacts to Wildlife Corridors and Habitat ConnectivityAs discussed in Section 5.9, Wildlife Corridor and Habitat Linkages, the Treatment Plant and Project site is located between two large open space systems which provides regional habitat connectivity for a variety of wildlife. However, the existing Treatment Plant is fully enclosed with a chain-linked fence. Therefore, the Treatment Plant provides no opportunities for wildlife movement and Project activities within the Treatment Plant are not expected to affect wildlife corridors. Although the proposed debris basin is located within undeveloped open space, the location and proposed permanent impact areas (0.09 acres of scrub within the open space area) are adjacent to the existing fenced facility (extending out to approximately 47 feet southeast of the fence line). In addition, no new lighting is proposed within or adjacent to open space for this Project. With abundant surrounding open spaces and opportunities for movement, the construction of the debris basin at this location is not anticipated to impede, interfere, or significantly affect wildlife movement, corridors, or linkages. Due to the relatively small size of the proposed Project, direct impacts to wildlife corridors and habitat connectivity are not anticipated to occur and indirect impacts to wildlife corridors and habitat connectivity are anticipated to be minor. Therefore, impacts to wildlife corridors and habitat connectivity would be less than significant. 6.10 Cumulative Impacts(14 CCR 15355).

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Evaluation of the proposed Project by the lead agency in the context of cumulative impacts would need to take into account those projects in the vicinity that occur in similar habitat and environmental settings. Individually, the proposed Project (with implementation of recommended mitigation measures) is likely to result in minimal impacts to native habitat, special-status species, jurisdictional resources, and habitat connectivity, as described in the above sections. 7 Recommended MeasuresMM-BIO-1 Habitat Mitigation and Monitoring Plan. Prior to issuance of a Project grading permit, the Applicant shall contract with a qualified botanist/biologist to develop a Habitat Mitigation and Monitoring Reporting Plan (Plan) to provide compensatory mitigation for permanent impacts to 0.03 acre of lemonade berry scrub and 0.06 acre of lemonade berry scrub California sagebrush scrub (California Department of Fish and Wildlife (CDFW) sensitive vegetation communities). The Plan shall outline efforts to restore or enhance these sensitive vegetation communities, and, therefore, preserve or provide wildlife habitat within similar upland habitats adjacent to the impacted biological resources. The Plan may focus on the following:In-kind restoration of lemonade berry scrub and/or lemonade berry scrub California sagebrush scrub through incorporation of these communities; orRestoration of areas occupied by non-native habitats or native habitats with large components of non-native vegetation, within similar habitats adjacent to the impacted biological resources.Under the Plan, a total of 0.09 acres permanently impacted upland vegetation communities shall be mitigated in-kind at 2:1 for a total of 0.18 acre of compensatory mitigation. A qualified biologist/botanist shall develop the Plan, which shall provide specific measures to restore or enhance habitat to replace the loss of permanently impacted communities. This Plan shall be focused on adaptive management principles and shall identify detailed enhancement areas and strategies based on the parameters outlined below, with long-term timing and monitoring requirements. The Plan shall also address the approximately 0.01 acres (315 square feet; 105 linear feet) of non-wetland waters of the State, including up to mapped top of bank; and 0.01 acre (332 square feet) of riparian (blue elderberry scrub) permanently impacted by the Project. The plan shall provide for compensatory mitigation at a minimum 3:1 ratio for of in-kind or similar mitigation, or other compensatory mitigation approved by the regulatory agencies. Specifically, the Plan will prescribe actions and measures to compensate for project impacts. The Plan will present project impacts, the site selection process, and a rationale for success, specifications regarding final mitigation acreages, site preparation, restoration implementation, plant and seed collection source and sizing, project implementation guidelines, interim and final ecological performance standards, requirements for long-term maintenance, monitoring, and reporting, and identify site protection and long-term management. The Plan will include the following elements: Mitigation ratios for permanent and temporary impacts (if any) to regulated aquatic resources including, but not limited to, riparian habitat, waters of the U.S., waters of the State, and CDFW streambed and riparian habitat will be established in consultation with the U.S. Army Corps of Engineers (USACE), Regional Water Quality Control Board (RWQCB), and California Department of Fish and Wildlife (CDFW).

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Provide site selection and justification.Detailed descriptions of mitigation components proposed to achieve the compensatory mitigation requirements of the resource agency permits.Plant palette(s) for each target vegetation community proposed to be restored to the mitigation site. Defined attainable and measurable mitigation goals and objectives to be achieved through implementation of the Plan.A restoration work plan that details the mitigation approach, a restoration schedule, plant materials (containers, seed), and implementation strategies. A detailed maintenance plan to include removal of invasives and non-native species.Defined ecological performance standards for determining the success of the mitigation program. A monitoring plan that includes method and analyses of results, goals for success or failure, and an adaptive management plan and suggestions for failed restoration efforts. Restoration activities using native riparian and wetland species from locally collected stock, if applicable.A description of protection measures and an estimate of long term management funding.An estimate of implementation costs. Annual reports and the final report shall be submitted to the City and applicable regulatory agencies.MM-BIO-2 Worker Education Awareness Program. Prior to the initiation of any site disturbance and/or construction activities, all personnel associated with the project shall attend a worker education awareness program (program) conducted by a qualified biologist. In general, it is recommended that the program discuss any potentially occurring sensitive biological resources or species and habitat preference(s), occupied habitat in the area, life histories, law and regulations, as well as potential construction impacts and protection measures, and project limits. Protections and regulations for biological resources, special-status species, protection of aquatic resources and open space, and nesting birds shall also be included in the program. It is recommended that a species and habitat fact sheet also be developed prior to the training program and distributed at the training program to all contractors, employers and other personnel involved with the construction of the Projects. After the kickoff meeting, the Project proponent should notify the qualified biologist in advance if additional contractors are employed during construction. A sign-in sheet will be circulated for signatures to all personal that attend the workers educational training to confirm that program materials were received and that they understand information presented. MM-BIO-3 Delimiting Construction Area. Prior to initiation of ground disturbance, grading, or equipment mobilization, the following measures shall be implemented to protect natural resources adjacent to construction areas:Install temporary fencing or equivalent form of demarcation along the perimeter of defined construction areas to protect natural resources.All construction-related activities shall be confined to the designated construction areas within the fenced/demarcated areas.

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Fencing/demarcation shall be maintained during the duration of the project, including fixing or replacing downed fence.Fencing/demarcation shall remain in place for the duration of the project until all project activities are complete.A qualified biological monitor shall monitor the condition of the fence, to ensure avoidance of impacts to surrounding resources.When sizable construction equipment is working near oak trees it is highly encouraged that flaggers are utilized to assist in equipment positioning to avoid impacts to oak tree canopies (not proposed for removal) during construction activities.MM-BIO4 Biological Monitoring and Reporting. A qualified biologist shall be present during all initial ground-disturbing activities (i.e., grading, trenching, grubbing, vegetation trimming or clearing)occurring within undeveloped areas (i.e., not the existing developed Treatment Plant areas). Each day prior to equipment mobilization, the biologist shall perform a clearance survey in which the work area and equipment within undeveloped areas is inspected for wildlife. The biologist shall provide guidance and ensure that biological resource protection measures are in place, to the maximum extent feasible. The monitor shall be experienced in construction monitoring and be able to identify potentially occurring sensitive biological resources in the area, including the coastal California gnatcatcher. The monitor shall survey the construction project footprint and surrounding areas for compliance with all environmental specifications. The biologist shall have authority to halt work if listed species are observed and immediately notify CDFW and/or USFWS (as applicable) and additional appropriate avoidance and minimization measures shall be implemented if determined necessary for the protection of special-status species. Sensitive wildlife species may only be moved from the work area by qualified biologists holding the required permits; however, endangered or threatened species will not be moved, harassed, or harmed and will be allowed to move out of harm on their own (unless other arrangements are approved by the regulatory agencies).Daily monitoring reports shall be prepared by the biologist and submitted to the appropriate permitting and responsible agencies on a weekly basis (weekly reporting). In addition, at the completion of monitoring activities, the biologist will submit a final monitoring report to the appropriate permitting and responsible agencies to document compliance with environmental requirements.MM-BIO-5 Erosion and Sediment Control Plan (ESCP).Due to the Project impact of less than 1 acre, theApplicant shall prepare an ESCP to minimize the potential for discharge of pollutants during construction activities. The ESCP shall be designed to meet the local requirements and County permitting process (e.g., grading or building permit). The ESCP shall include both structural and non-structural best management practices, including straw wattles around storm drains, silt fencing and or other physical controls to divert flows from exposed soil, spill prevention methods, and clean housekeeping methods for storing and refueling machinery. As part of the ESCP, the Contractor shall include specifications, installation requirements, and locations of appropriate best management practices to control sediment, coarse particles, concrete, and other materials exposed during construction and drilling, to protect aquatic and

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riparian habitats adjacent to construction site. Erosion control measures shall be implemented to prevent runoff of these materials into potential jurisdictional aquatic features. Silt fencing, straw bales, and/or sandbags should be used in conjunction with other methods to prevent turbid waters from entering the potential jurisdictional aquatic features. Best Management Practices (BMPs) shall be implemented which minimize impacts from the generation of fugitive dust, fire hazard, and chemical pollutants. During construction activities, washing of concrete or equipment shall occur only in areas where polluted water and materials can be contained for subsequent removal from the site. Washing shall not be allowed in locations where the tainted water could enter potential jurisdictional aquatic features.MM-BIO-6 Protected Tree Removal, Replacement, and Protective Measures.The City of Thousand Oaks requires a permit for removal, pruning, or encroachment into the protected zone of any oak tree or landmark tree, which are defined as:Oak Tree: any oak tree of the genus Quercus including, but not limited to, Valley Oak (Quercus lobata), California Live Oak (Quercus agrifolia) and Scrub Oak (Quercus berberidifolia), regardless of size (Thousand Oaks Municipal Code, Title 5, Chapter 14: Oak Tree Preservation and Protection).Landmark Tree: Specimens of the following species which have reached the designated maturity: California Sycamore (Platanus racemosa), which exdiameter when measured at a point four and one-grade at the base of the tree; California Bay Laurel (Umbellularia californica), which oint four and one-feet above the natural grade at the base of the tree; California Black Walnut (Juglans californica),and one-t the base of the tree; and Toyon(Heteromeles arbutifolia),at a point four and one-Trees with multiple trunks shall be deemed to have reached maturity if the sum of the single trunked tree. Landmark trees shall also include all designated historic trees. (Thousand Oaks Municipal Code, Title 5, Chapter 24: Landmark Tree Preservation and Protection).Prior to construction activities an International Society of Arboriculture (ISA) certified arborist shall review the proposed construction plans, visit the project site, and assess the condition, health, and structure of oak and landmark trees with a potential to be directly (removed or encroached upon) impacted by project activities, including trees proposed to be trimmed or removed. Encroachment shall include project related disturbances that would occur within the protected zone (a specifically defined area totally encompassing a landmark or historic tree within which work activities are strictly controlled). When depicted on a map, the outermost edge of the protected zone will appear as an irregular shaped circle that follows the contour of the dripline of the tree. Using the dripline as a point of reference, the protected zone shall commence

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ca(both code sections).The certified arborist shall provide a letter/report (Oak Tree Report) containing specific information on the location, condition, potential impacts of development, recommended actions and mitigation measures. At minimum, mitigation measures shall include requirements for arborist monitoring during work within the tree protected zone (i.e., within 5 feet of the oak tree canopy or within 15 feet from the base of the tree trunk) of any oak or landmark trees. The City of Thousand Oaks Oak Tree Preservation and Protection Guidelines mitigation requirements for tree removals associated with development projects are summarized as follows: one (1) fifteen (15) gallon oak tree to be planted or donated for each dead or hazardous oak tree removed; two (2), twenty-, thirty-be planted for each healthy oak tree removed for commercial, industrial, and new residential development projects; in the case of removal of oak trees larger than forty-diameter, the applicant is required to obtain the largest nursery grown oak tree available or plant The letter descriptions and all project activities shall comply with local oak tree regulations (i.e., Municipal Code Section 9-4.42, Oak Tree Preservation and Protection Ordinance; Municipal Code Section 9-4.43, Landmark Tree Preservation and Protection Ordinance; Oak Tree Ordinance, Title 5, Chapter 14 of the Thousand Oaks Municipal Code; and the Oak Tree Preservation and Protection Guidelines Res. No. 2010-014). MM-BIO-7 Reptile Pre-Construction Survey. A pre-construction survey for California legless lizard, San 30 days prior to the initiation of Project activities. If these species are observed, a salvage and relocation plan would be implemented to allow a qualified biologist to capture and relocate the species away from ground disturbance and into protected open space. These survey and reporting measures are often a MM-BIO-8 Pre-Construction Nesting Bird Survey. A pre-construction survey for nesting birds shall be conducted by a City of Thousand Oaks-approved biologist to determine if active (nests containing eggs, nestlings, or associated with dependent fledglings) of special-status birds, or common bird species protected by the Migratory Bird Treaty Act and/or the California Fish and Game Code, are present in the construction zone or within 300 feet of the construction zone. The survey shall be conducted within 1 week prior to construction or site preparation activities that would occur during the nesting/breeding season of native bird species potentially nesting on the site (typically February 1 through August 31). The pre-construction nesting bird survey shall be repeated if there is a delay in the start of construction activity or there is a lapse in construction activity of 2 weeks or greater has occurred.Within 1 week before the start of construction activities, a City of Thousand Oaks-approved biologist shall conduct the nesting bird survey. A preconstruction nesting bird report shall be completed and submitted to the City of Thousand Oaks.If active nests are found, a no-construction buffer shall be established at a minimum of 50 feet for non-raptor bird species and 200 feet for raptor species (this distance may be greater depending

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on the bird species and construction activity, as determined by the City of Thousand Oaks-approved biologist) around the nest site where it overlaps with work areas. Tree and vegetation clearing and construction within the no-construction buffer shall be postponed or halted, at the discretion of the City of Thousand Oaks-approved biologist, until the nest is vacated, juveniles have fledged, and there is no evidence of a second attempt at nesting. In addition, all active nests shall be mapped with a GPS unit and nest locations with 100-foot buffers overlain on aerial photographs to provide regular updated maps to inform the Project manager/engineer and construction crew of areas to avoid. The City of Thousand Oaks-approved biologist shall also serve as a construction monitor during the breeding season to ensure that there are no inadvertent impacts to nesting birds.Bird nest surveys shall be conducted every 14 days following identification of an active bird nest until all birds have fled the nest and the nest is deemed inactive by the City of Thousand Oaks-approved biologist. A bird nest monitoring report shall be completed and submitted to the City of Thousand Oaks within 48 hours of each survey.MM-BIO-9 Coastal California Gnatcatcher Surveys and Avoidance. Prior to construction, protocol-level surveys for the coastal California gnatcatcher should be performed within 500 feet of proposed temporary and permanent impact areas. If any individuals are detected during the surveys, the results should be communicated to the USFWS for approvals prior to construction. In the absence of protocol surveys, the USFWS shall be consulted for further guidance.

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8 ReferencesAccessed July 2021. https://americanornithology.org/publications/north-and-middle-american-checklist/.Capron, M.E. 2017. City of Thousand Oaks, Hill Canyon Wastewater Treatment Plant (HCTP), Stormwater Permit Notice of Non-Applicability via No Discharge. Dated June 27, 2017. Water Board Date Processed: July 5, 2017. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=18959.CDFW. 2022a. Rarefind 5: Commercial version. Online database. California Natural Diversity Database. CDFW,Biogeographic Data Branch. Accessed March 2022. https://wildlife.ca.gov/Data/CNDDB/Maps-and-Data.CDFW. 2022bJuly 5. https://www.wildlife.ca.gov/Data/VegCAMP/Natural-Communities.CDFW. 2022c. Special Vascular Plants, Bryophytes, and Lichens List. July 2022. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=109383&inline.CDFW. 2022d.https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=109406&inline.CDFW. 2022e. Biogeographic Information and Observation System (BIOS). Layers: South Coast Missing Linkages (ds419) and Habitat Connectivity Ventura County (ds565). https://wildlife.ca.gov/Data/BIOSCity of Thousand Oaks. 2013. Conservation Element of the Thousand Oaks General Plan. Community Development Department. Adopted October 2013.City of Thousand Oaks. 2017. Community Forest Element of the Thousand Oaks General Plan. Community Development Department. Adopted April 11, 2017.City of Thousand Oaks. 2018. Land Use and Circulation Element of the Thousand Oaks General Plan. Community Development Department. Updated through Resolution 2018-017, adopted April 24, 2018. City of Thousand Oaks. 2019. Hill Canyon Treatment Plant (HCTP) Stormwater Permit Notice of Non-Applicability via No Discharge, Amended Technical Analysis. City of Thousand Oaks, Public Works Department. File Dated October 30, 2019. City of Thousand Oaks. 2022. City of Thousand Oaks Public Access Map. https://city-of-thousand-oaks-arcgis-hub-toaks.hub.arcgis.com/revised June 2, 2001. http://www.cnps.org/cnps/rareplants/pdf/cnps_survey_guidelines.pdf.

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CNPS. 2022a. Inventory of Rare and Endangered Plants of California. California Native Plant Society, Rare Plant Program. (online edition, v9-01 1.5). Accessed March 2022. https://www.rareplants.cnps.org.CNPS. 2022b. A Manual of California Vegetation. Online. Accessed August 2022. https://vegetation.cnps.org/Crother, B.I. 2017. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in our Understanding. 8th ed. Herpetological Circular No. 43. Edited by J.J. Moriarty. Shoreview, Minnesota: Society for the Study of Amphibians and Reptiles.te University, Stanislaus, Endangered Species Recovery Program. Revised July 2002. https://www.fws.gov/sacramento/es/Survey-Protocols-Guidelines/Documents/rare_plant_protocol.pdf.Magney, D.L. 2020. Checklist of Ventura County Rare Plants. California Native Plant Society, Rare Plant Program, Locally Rare Project. Updated September 21, 2020.Mammal Diversity Database. 2021. Mammal Diversity Database (Version 1.5) [Data set]. Zenodo. http://doi.org/10.5281/zenodo.4139818.Moyle, P.B. 2002. Inland Fishes of California. Berkley: University of California Press. of North American Butterflies, edited by B. Cassie, J. Glassberg, A. Swengel, and G. Tudor. 2nd ed. Morristown, New Jersey: NABA. Accessed February 23, 2017. http://www.naba.org/pubs/enames2_3.html.Sawyer, J., T. Keeler-Wolf, and J. Evens. 2009. A Manual of California Vegetation, Second Edition. California Native Plant Society, Sacramento, CA. 1300 pp.https://vegetation.cnps.org/.SC Wildlands (South Coast Wildlands). 2008. South Coast Missing Linkages: A Wildland Network for the South Coast Ecoregion. The South Coast Missing Linkages Project. http://www.scwildland.org/reports/SCMLRegionalReport.pdf.Shuford, W.D., and T. Gardali. 2008. California Bird Species of Special Concern: A Ranked Assessment of Species, Subspecies, and Distinct Populations of Birds of Immediate Conservation Concern in California. Studies of Western Birds 1. February 4, 2008. Sacramento: CDFG, and Camarillo, California: Western Field Ornithologists. SDNHM (San Diego Natural History Museum). 2002. "Butterflies of San Diego County. Revised September 2002." Accessed October 14, 2016. http://www.sdnhm.org/archive/research/entomology/sdbutterflies.html.USACE (U.S. Army Corps of Engineers). 1987.Corps of Engineers Wetlands Delineation Manual.U.S. Army Corps of Engineers, Environmental Laboratory.USACE. 2008a.Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region.U.S. Army Corps of Engineers, Environmental Laboratory.USACE. 2008b.A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States. U.S. Army Corps of Engineers, Environmental Laboratory.

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USDA (U.S. Department of Agriculture). 2022aNatural Resources Conservation Service, Soil Survey Staff. http://websoilsurvey.nrcs.usda.gov/.USDA. 2022b.National Hydric Soils List by State. https://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/use/hydric/.USFWS (U.S. Fish and Wildlife Service). Washington, DC: USFWS. May 19, 2021. https://www.fws.gov/media/birds-conservation-concern-2021pdf.March 2022. https://ecos.fws.gov/ipac/.https://ecos.fws.gov/ecp/report/table/critical-habitat.html.USFWS. 2022d. Occurrence Data [GIS data]. Last accessed August 2022. http://nhd.usgs.gov/data.html. Ventura County. 2022. Habitat Connectivity and Wildlife Corridors Map. https://rma.maps.arcgis.com/apps/webappviewer/index.html?id=92c5352af22a44a3a99dd41aa1b8d567.Ventura County Planning Division. 2014. Locally Important Animal List. https://docs.vcrma.org/images/pdf/planning/conservation/2014-Locally-Important-Animal-List.pdf.Ventura County Planning Division. 2018. Locally Important Plant List. https://docs.vcrma.org/images/pdf/planning/conservation/2018-Locally-Important-Plant-List.pdf.

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Appendix A 100% Site Plans (May 6, 2022)

Appendix B Aquatic Resources Delineation Report

MARCH 2023Prepared for:CITY OF THOUSAND OAKS2100 E. Thousand Oaks BoulevardThousand Oaks, California 91362Contact: Nader HeydariPrepared by:621 Chapala StreetSanta Barbara, California 93101Contact: Melissa [email protected]

Printed on 30% post-consumer recycled material.

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Table of ContentsSECTION PAGE NO.Acronyms and Abbreviations............................................................................................................................................ iii1 Introduction ..........................................................................................................................................................11.1 Disclaimer Statement ............................................................................................................................11.2 Contact Information ...............................................................................................................................12 Site Description and Landscape Setting ............................................................................................................12.1 Soils.........................................................................................................................................................22.2 Vegetation...............................................................................................................................................22.3 Watershed...............................................................................................................................................22.4 National Wetland Inventory ...................................................................................................................33 Aquatic Resources Delineation Methods ...........................................................................................................34 Aquatic Resources Narrative...............................................................................................................................44.1 Waters of the United States...................................................................................................................54.2 Waters of the State ................................................................................................................................55 Results and Conclusions .....................................................................................................................................76 References Cited..................................................................................................................................................8TABLES1 Applicant and Agent Contact Information...........................................................................................................12 Schedule of the Aquatic Resources Delineation...................................................................................................33 RWQCB Aquatic Resource Summary for the Biological Survey Area ................................................................64 CDFW Aquatic Resource Summary for the Biological Survey Area ...................................................................6FIGURES1 Project Location ...................................................................................................................................................92 Soils .............................................................................................................................................................. 113 Hydrologic Setting ............................................................................................................................................. 134 Potential Jurisdictional Aquatic Resources ..................................................................................................... 15APPENDICESA Photo DocumentationB Data Forms

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Acronyms and AbbreviationsAcronym/AbbreviationDefinitionCDFW California Department of Fish and WildlifeOHWM ordinary high-water markProject Hill Canyon Treatment Plant Stormwater Diversion ProjectRWQCB Regional Water Quality Control BoardUSACE U.S. Army Corps of Engineers

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1 IntroductionThis Aquatic Resources Delineation Report is being prepared for the City of Thousand Oaks for the Hill Canyon Treatment Plant Stormwater Diversion Project (Project). The delineation was performed to identify and map existing aquatic resources potentially subject to the regulatory jurisdiction of the U.S. Army Corps of Engineers (USACE) pursuant to Section 404 of the Clean Water Act (33 USC 1344); Regional Water Quality Control Board (RWQCB) pursuant to Section 401 of the Clean Water Act and the Porter-Cologne Water Quality Control Act; and/or California Department of Fish and Wildlife (CDFW) pursuant to Section 1602 of the California Fish and Game Code (collectively defined as jurisdictional aquatic resources).1.1 Disclaimer StatementThis reporRWQCB, and CDFW (i.e., regulatory agencies) within the Project site using the current regulations, written policies, and guidance from these regulatory agencies. The potential jurisdictional boundaries described in this report are subject to verification by the regulatory agencies. Only the regulatory agencies can make a final determination on whether the features present are subject to USACE, RWQCB, and/or CDFW regulation. 1.2 Contact InformationContact information for the Project applicant and agent are provided in Table 1. Access to the Project site is not restricted, but if a site visit is requested, the Project applicant or agent will accompany regulatory staff to the Project site. City of Thousand Oaks is the Project applicant and landowner. Table 1. Applicant and Agent Contact InformationApplicantCity of Thousand OaksAgentPhoenix Civil EngineeringContactNameNader HeydariContactNameJon TurnerAddress2100 E. Thousand Oaks BoulevardThousand Oaks, California 91362Address535 E. Main Street Santa Paula, California 93060Phone805.449.2392Phone805.658.6800FaxNAFaxNAEmailnheydari@[email protected] Site Description and Landscape SettingThe Hill Canyon Treatment Plant (552-013-001 and 667-012-017) is located at 9600 Santa Rosa Road, Thousand Oaks, California (Figure 1, Project Location). The Project site is located within U.S. Geological Survey 7.5-minute Newberry Park quadrangle, Section 00 of Township 2 North and Range 20 West; the approximate center of the Project site is longitude 34°1239.00118°5516.02

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(34.210832;118.921117). To drive to the Project site from Camarillo, take Santa Rosa Road east and turn right onto Hill Canyon Road, which will take you to the entrance of Hill Canyon Treatment Plant. The Project site is located between two publicly owned open space systems including Wildwood Regional Park, approximately 1,765 acres, and Conejo Canyons Open Space, approximately 1,430 acres. As a result, the surrounding area is predominantly open space with residential and commercial properties approximately 0.25 miles south and east of the site.A Biological Survey Area (BSA) was considered as the review area for this Project site. The BSA includes the proposed Project impact areas (Project site) and a 100-foot buffer. Topography within the BSA is variable, characterized by moderately steep slopes that lead down towards a vegetated canyon containing a linear aquatic feature. Thisunnamed feature originates southeast of the site within Wildwood Regional Park. Elevation ranges from approximately 280 feet above mean sea level in the southwestern portion of the BSA (near the manhole work area)to 400 feet above mean sea level south of the proposed debris basin. 2.1 SoilsSoil types within and surrounding the BSA are shown on Figure 2. As shown on Figure 2, soils within the natural landscapes of the BSA consist mainly of Hambright very rocky loam (HaG; 15% to 75% slopes), a shallow, well-drained soil which typically occurs on plateaus, basalt flows, and hillslopes (USDA-NRCS 2022a). Vina gravelly loam (VnC; 2% to 9% slopes) occurs along the northwestern portions of the BSA and primarily within the existing treatment plant. A third soil type, Vina loam (VaC; 2% to 9% slopes) also occurs in a portion of the existing treatment plant. The Vina soil series consists of very deep, well-drained soils (USDA-NRCS 2022a). These soils are not considered hydric soils (USDA-NRCS 2022b). 2.2 VegetationThe natural vegetated lands of the BSA are composed of a combination of vegetation communities including Chamise black sage sugarbush scrub, California brittlebrushCalifornia sagebrush scrub, lemonade berry scrub, and lemonade berry scrubCalifornia sagebrush scrub. Along with the scrub communities, mature oak trees (California black oak [Quercus kelloggii], coast/interior live oak [Q. agrifolia/wislizeni]) and scattered toyon (Heteromeles arbutifolia) and other scrub shrubs are present. In the southern portion of the BSA, near the manhole work area, California sycamorearroyo willow woodlands were mapped along Arroyo Conejo creek and non-native grasslands were present. Since the creek and majority of non-native grasslands are located outside of the BSA, only the fringes of these communities entered the edges of the BSA near the manhole work area. The scrub communities and oaks near the linear aquatic feature on site do not appear to be significantly supported by this channel, as individual oaks are present along the hillslope where the channel is not present and do not necessarily originate or line the linear aquatic feature banks (Appendix A, Photo Documentation). 2.3 WatershedThe BSA is located within the Ventura-San Gabriel Coastal basin Hydrologic Unit (180701) and Upper Conejo Arroyo subwatershed Hydrologic Unit (180701030104). The Upper Conejo Arroyo subwatershed covers an area of 27,665 acres (112 square kilometers) and encompasses the areas of Potrero Valley, Conejo Valley, and east to OakbrookRegional Park (ArcGIS 2022). See Figure 3, Hydrologic Setting.

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2.4 National Wetland InventoryThe BSA contains one(USFWS 2022; see Figure 4). This resource is located along the northeastern portion of the BSA (i.e., area associated with the debris basin), originates from the undeveloped hills along the east, and travels downslope to the treatment plant. This feature is categorized as Freshwater Forested/Shrub Wetland (PSAA Cowardin classification). This categorization would suggest the presence of a wetland feature consisting of an area dominated by woody vegetation, with surface water present for brief periods of time during the growing season. 3 Aquatic Resources Delineation MethodsDudek Biologist Heather Moine conducted an aquatic resources delineation for the BSA in March 2022. Table 2summarizes the site conditions and timing of the survey. Table 2. Schedule of the Aquatic Resources Delineation DateHours1PersonnelConditions03/21/2022 9:07 a.m.5:20 p.m. Heather Moine 59°F73°F; 20%40% cloud cover;14 mph windNotes:°F = degrees Fahrenheit, mph = miles per hour.1The total site visit included aquatic resources delineation, supplemental vegetation mapping, and rare plant surveys.Jurisdictional boundaries were mapped in the field using ESRI Field Maps and a Trimble® R1 GNSS Receiver with submeter accuracy and aerial imagery. Following the fieldwork, aquatic resources were digitized using ArcGIS. The jurisdiction-specific methods used to delineate USACE, CDFW, and RWQCB are described below.Maps are included at the end of this report, including Project Location (Figure 1), Soils (Figure 2), Hydrologic Setting (Figure 3), and Potential Jurisdictional Aquatic Resources (Figure 4). U.S.ArmyCorpsofEngineersJurisdictionalDelineationMethodsThe USACE wetlands delineation was conducted in accordance with the 1987 USACE Wetlands Delineation Manual (USACE 1987) and the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (USACE 2008a). A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States: A Delineation Manual (USACE 2008b) was used to determine the limits of non-wetland waters. Non-wetland waters were delineated on topographical maps in conjunction with ESRI Field Maps on a mobile device. The widths of each non-wetland water were determined in the field according to the OHWM manual. Wetland Determination Forms were taken at certain points within drainages or vegetation communities where a predominance of hydrophytic vegetation was present; hydrology, vegetation, and soils were assessed to determine whether USACE three-parameter wetlands were present. USACE OHWM Forms were completed at representative cross-sections of non-wetland waters to capture their characteristics and widths. Data forms can be found in Appendix B.

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CaliforniaDepartmentofFishandWildlifeJurisdictionalDelineationMethodsThe delineation defined areas under the jurisdiction of the CDFW pursuant to Sections 16001603 of the California Fish and Game Code. CDFW asserts jurisdiction over rivers, streams, and lakes to the extent of the top of bank. The away from it (Vyverberg 2010). Top of bank was mapped as the physical break in slope between the channel and surrounding upland. CDFW also asserts jurisdiction over riparian vegetation associated with these features. A predominance of hydrophytic vegetation, where associated with a stream channel, was used to determine CDFW-regulated riparian areas. Streambeds under the jurisdiction of CDFW were delineated using the Cowardin method of waters classification, which defines waters boundaries by a single parameter (i.e., hydric soils, hydrophytic vegetation, or hydrology). Additionally, waters of the state were delineated based on watercourse characteristics present in the field, which include surface flow, sediment transportation and sorting, physical indicators of channel forms, channel morphology, and riparian habitat associated with a streambed.RegionalWaterQualityControlBoardJurisdictionalDelineationMethodsIn 2019, the State Water Resources Control Board issued the State Wetland Definition and Procedures for Discharges of Dredged or Fill Material to Waters of the State (SWRCB 2019). These procedures define wetlands protected under federal law, and reflects current scientific understanding of the formation and functioning of the area has continuous or recurrent saturation of the upper substrate caused by groundwater, or shallow surface water, or both; (2) the duration of such saturation is sufficient to cause anaerobic conditions in the upper substrate; and (3) the Waters of the state regulated by the RWQCB were mapped in accordance with the State Wetland Definition and Procedures for Discharges of Dredged or Fill Material to Waters of the State (SWRCB 2019). Wetland waters subject to RWQCB jurisdiction were mapped based on methods described in the 1987 Corps of Engineers Wetlands Delineation Manual (USACE 1987) and the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (USACE 2008a). Non-wetland waters subject to RWQCB jurisdiction were delineated to the extent of the top of bank and riparian vegetation, as appropriate, as described above.4 Aquatic Resources NarrativeOn March 21, 2022, Ms. Moine performed an aquatic resources delineation. Potentially jurisdictional aquatic features mapped include a concrete v-ditch, connecting swale, and an ephemeral channel (Figure 4). These features are located within and directly adjacent to the proposed debris basin. Of these features, only the ephemeral channel is anticipated to require additional permits pursuant to the Porter-Cologne Water Quality Control Act and California Fish and Game Code for impacts to the channel. However, as recommended below, written concurrence from the resource agencies (RWQCB, CDFW, and USACE) on the jurisdictional status for both features is highly recommended.

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ConcreteV-Ditch(RWQCB)The concrete v-ditch is an existing stormwater control feature within the Hill Canyon Treatment Plant that directs flows to drain-inlets along the v-ditch (Figure 4). The drain inlets are regularly maintained by Hill Canyon Treatment Plant staff as part of storm preparedness activities. These inlets capture storm flows and drain them to the sludge drying beds as part of the stormwater capture program (Capron 2017; City of Thousand Oaks 2019). Since the flows associated with the v-ditch are currently subject to the adopted Waste Discharge Requirements and National Pollutant Discharge Elimination System permits for the Hill Canyon Treatment Plant (Order No. R4-2019-0137, NPDES No. CA0056294), compliance with this existing permit should apply to this feature and further permits are not anticipated to be necessary from the RWQCB. We understand the Hill Canyon Treatment Plant had previously attained status as a zero-discharge facility. An Industrial General Permit Notice of Non-Applicability was previously granted by the RWQCB, and the City is petitioning to retain this status with site modifications to re-route off-site flows from the natural canyon and directly to Arroyo Conejo Creek (Capron 2017; City of Thousand Oaks 2019). In addition, the concrete v-ditch is unlikely to be jurisdictional to USACE under the Clean Water Act, as the feature is ephemeral and current flows lack a connection with a traditional navigable water. Similarly, the feature lacks a bed and bank often associated with CDFW jurisdictional rivers, stream, or lakes. EphemeralChannel(RWQCB/CDFW)A narrow ephemeral channel is present in the BSA within and adjacent to the proposed debris basin (Figure 4). The channel is located within the natural canyon and extends to the existing concrete v-ditch. This channel is characterized by an OHWM and a bed, with portions of the channel containing a bank. Blue elderberry (Sambucus mexicana) is present along this feature providing limited riparian habitat. In addition, a short 12-foot swale connects the feature in the eastern portion of the BSA. These features are anticipated to be jurisdictional to CDFW and the RWQCB. Given that the feature is ephemeral and lacks connection with a traditional navigable water, it is unlikely to be jurisdictional to USACE. 4.1 Waters of the United StatesAs described above, no features observed are anticipated to be Waters of the United States; and therefore, not anticipated to be under the jurisdiction of the U.S. Army Corps of Engineers. The concrete v-ditch is ephemeral and current flows lack a connection with a traditional navigable water. The ephemeral channel does not have direct connection to a traditional navigable water, is characterized by low volume or infrequent flows, and flows through this feature are directed through the existing treatment plant. 4.2 Waters of the State RegionalWaterQualityControlBoard(RWQCB)The concrete v-ditch and ephemeral channel, described above, are anticipated to be under the jurisdiction of the RWQCB. Therefore, approximately 0.04 acre (534 linear feet) of features are anticipated to be subject to regulation by the RWQCB under the Porter-Cologne Water Quality Control Act. Table 3 provides a summary of these features. However, based on existing permits only the channel is anticipated to require additional permitting for project-related activities.

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Table 3. RWQCB Aquatic Resource Summary for the Biological Survey AreaFeatureNameLocation(Latitude/Longitude;DecimalDegrees)BiologicalSurveyArea(Acres/LinearFeet)Non-WetlandWatersEphemeral channel(including top of bank)34.210854,-118.9209710.01 acre (530 square feet)219 linear feetUpland Swale 34.210701-118.920611< 0.01 (12 square feet)212 linear feetConcrete v-ditch 34.211035,-118.9210580.02 acre (758 square feet)303 linear feetRiparianBlue Elderberry (outside of ephemeral channel and bank)34.210892-118.920957< 0.01 (332 square feet)23 linear feet3Total10.04acre(1,632squarefeet)534linearfeet3Notes:1Totals may not sum due to rounding.2Swale width estimated at 1 foot. 3Riparian linear feet not included in total due to overlapping with the ephemeral channel. CaliforniaDepartmentofFishandWildlifeThe ephemeral channel described above is anticipated to be regulated by CDFW. Since CDFW regulates from bank to bank, certain portions of the BSA where the top of a channel bank extended beyond the OHWM are subject to regulation by CDFW as streambed. These areas are displayed on Figure 4. The oak trees located adjacent to the channel feature may not be jurisdictional to CDFW (but will require confirmation from CDFW). The oak trees on-site and along this channel feature do not readily appear to originate from the channel feature or appear to significantly benefit from the channel flows. The oaks near the channel originate uphill from the channel feature on upland slopes. In addition, based on the surrounding environment, oak trees are scattered throughout the upland slopes and terrain suggesting that the presence of oaks along the channel would have been present irrespective of the . Therefore, the oaks adjacent to the channel are unlikely to be categorized as riparian vegetation that is typically under CDFW jurisdiction. However, one blue elderberry plant is located along the channel and is mapped as riparian under CDFW jurisdiction.Therefore, approximately 0.02 acres (231 linear feet) of features are anticipated to be subject to regulation by the CDFW under the California Fish and Game Code Section 1600 et seq. The full extent of CDFW jurisdictional areas are those described in Table 4. Table 4. CDFW Aquatic Resource Summary for the Biological Survey AreaFeatureNameLocation(Latitude/Longitude;DecimalDegrees)BiologicalSurveyArea(Acres/LinearFeet)StreambedEphemeral channel(including top of bank)34.210854,-118.9209710.01 acre (530 square feet)219 linear feet

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Table 4. CDFW Aquatic Resource Summary for the Biological Survey AreaFeatureNameLocation(Latitude/Longitude;DecimalDegrees)BiologicalSurveyArea(Acres/LinearFeet)Upland Swale 34.210701-118.920611< 0.01 (12 square feet)212 linear feetRiparianBlue elderberry (Sambucus mexicana)34.210892,-118.9210957< 0.01 (332 square feet)23 linear feet3Total10.02acre(874squarefeet)231linearfeet3Notes:1Totals may not sum due to rounding.2Swale width estimated at 1 foot. 3Riparian linear feet not included in total due to overlapping with the ephemeral channel. 5 Results and ConclusionsBased on the jurisdictional delineation and review of relevant information provided in this Aquatic Resources Delineation Report, approximately 0.03 acres (1,300 square feet) of non-wetland waters of the state and an additional < 0.01 acre (332 square feet) of riparian habitat are potentially regulated by the RWQCB and/or CDFW. The features described in this report are not anticipated to be under the jurisdiction of the USACE. This report can be used by those agencies to determine if they would regulate the features described herein.

HILL CANYON TREATMENT PLANT STORMWATER DIVERSION PROJECT / AQUATIC RESOURCES DELINEATION REPORT 127678MARCH 2023
6 References Citedhttps://www.arcgis.com/apps/mapviewer/index.html?layers=518ab8bc00dd4caea87d52694c7734d7.Capron, M.E. 2017. City of Thousand Oaks, Hill Canyon Wastewater Treatment Plant (HCTP), Stormwater Permit Notice of Non-Applicability via No Discharge. Dated June 27, 2017. Water Board Date Processed: July 5, 2017. City (City of Thousand Oaks). 2019. Hill Canyon Treatment Plant (HCTP) Stormwater Permit Notice of Non-Applicability via No Discharge, Amended Technical Analysis. City of Thousand Oaks, Public Works Department. File Dated October 30, 2019. SWRCB (State Water Resources Control Board). 2019. State Policy for Water Quality Control: State Wetland Definition and Procedures for Discharges of Dredged or Fill Material to Waters of the State. Adopted April 2, 2019, and revised April 6, 2021. USACE (U.S. Army Corps of Engineers). 1987. Corps of Engineers Wetlands Delineation Manual. Online ed. Environmental Laboratory, Wetlands Research Program Technical Report Y-87-1. Vicksburg, Mississippi: U.S. Army Engineer Waterways Experiment Station. January 1987. http://www.cpe.rutgers.edu/Wetlands/1987-Army-Corps-Wetlands-Delineation-Manual.pdf.USACE. 2008a. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0). Environmental Laboratory, ERDC/EL TR-08-28. Vicksburg, Mississippi: U.S. Army Engineer Research and Development Center. September 2008. https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1046489.pdf.USACE. 2008b. A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States: A Delineation Manual. ERDC/CRREL TR-08-12. Prepared by R.W. Lichvar and S.M. McColley. Hanover, New Hampshire: U.S. Army Engineer Research and Development Center, Cold Regions Research and Engineering Laboratory. August 2008. https://apps.dtic.mil/dtic/tr/fulltext/u2/a486603.pdf.USDA-NRCS (U.S. Department of Agriculture, Natural Resources Conservation Service). 2022a. Web Soil Survey.Accessed August 2022. https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm.USDA-NRCS. 2022bmain/soils/survey/class/.Vyverberg, K. 2010. A Review of Stream Processes and Forms in Dryland Watersheds. California Department of Fish and Wildlife. December 2010. 101
Project LocationSOURCE: Source0 2,0001,000FeetProject SiteFIGURE 1 Port HuenemeOxnardVenturaThousand OaksCamarilloMoorparkFillmoreOjaiSimi ValleyK e r n C o u n t yS a n t aB a r b a r aC o u n t yL o s A n g e l e sC o u n t yProject Site

Thousand Oaks City CouncilMarch 25, 2025

Thousand Oaks City Council
March 25, 2025