DraftFinal
Initial Study/Mitigated Negative
Declaration for the Riverview
Development Project, Santa Clarita,
California
JUNEOCTOBER 2024
PREPARED FOR
City of Santa Clarita
Planning Division
PREPARED BY
SWCA Environmental Consultants
DRAFT FINAL INITIAL STUDY/MITIGATED NEGATIVE
DECLARATION FOR THE
RIVERVIEW DEVELOPMENT PROJECT,
SANTA CLARITA, CALIFORNIA
Prepared for
City of Santa Clarita, Planning Division
23920 Valencia Boulevard
Santa Clarita, California 91355
Attn: Justin Sauder
Prepared by
SWCA Environmental Consultants
320 North Halstead Street, Suite 120
Pasadena, California 91107
(626) 240-0587
www.swca.com
SWCA Project No. 75841
June October 2024
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration i
CONTENTS
Acronyms and Abbreviations ................................................................................................................... iii 1 Introduction .......................................................................................................................................... 1
1.1 California Environmental Quality Act ...................................................................................... 1
1.2 Project Location and Environmental Setting ............................................................................. 1
1.3 General Plan and Zoning Designations ..................................................................................... 4
1.4 Project Description .................................................................................................................... 5
1.4.1 Project Overview ................................................................................................................ 5
1.4.2 Proposed Buildout ............................................................................................................... 5
1.4.3 Access, Circulation, and Parking ........................................................................................ 7
1.4.4 Landscaping ........................................................................................................................ 9
1.4.5 Utility and Drainage Improvements .................................................................................... 9
1.4.6 Grading ............................................................................................................................... 9
1.4.7 Lighting ............................................................................................................................. 10
1.4.8 Off-site Improvements ...................................................................................................... 10
1.4.9 Construction Schedule and Equipment ............................................................................. 10
1.5 Required Discretionary Approvals .......................................................................................... 10
1.6 Intended Uses of this Document.............................................................................................. 11 2 Environmental Checklist and Environmental Evaluation .............................................................. 12 I. Aesthetics ................................................................................................................................ 13 II. Agriculture and Forestry Resources ........................................................................................ 15 III. Air Quality ............................................................................................................................... 17 IV. Biological Resources ............................................................................................................... 27 V. Cultural Resources .................................................................................................................. 37 VI. Energy ..................................................................................................................................... 41 VII. Geology and Soils ................................................................................................................... 43 VIII. Greenhouse Gas Emissions ..................................................................................................... 49 IX. Hazards and Hazardous Materials ........................................................................................... 54 X. Hydrology and Water Quality ................................................................................................. 60 XI. Land Use and Planning ............................................................................................................ 67 XII. Mineral Resources ................................................................................................................... 69 XIII. Noise ........................................................................................................................................ 70 XIV. Population and Housing .......................................................................................................... 75 XV. Public Services ........................................................................................................................ 76 XVI. Recreation ................................................................................................................................ 79 XVII. Transportation ......................................................................................................................... 80 XVIII. Tribal Cultural Resources ........................................................................................................ 84 XIX. Utilities and Service Systems .................................................................................................. 89 XX. Wildfire ................................................................................................................................... 94 XXI. Mandatory Findings of Significance ....................................................................................... 99 3 Literature Cited ................................................................................................................................ 101 4 List of Preparers ............................................................................................................................... 108
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration ii
5 Mitigation Monitoring and Reporting Program ............................................................................ 109
5.1 Statutory Requirements ......................................................................................................... 109
5.2 Administration of the Mitigation Monitoring and Reporting Program ................................. 109
5.3 Mitigation Measures .............................................................................................................. 109
Appendices
Appendix A. Air Quality and Greenhouse Gas Analyses
Appendix B. Biological Resource Reports
Appendix C. Archaeological Resources Technical Report
Appendix D. Built Environment Report
Appendix E. Paleontological Resources Technical Memorandum Appendix F. Hazardous Materials Assessment
Appendix G. Hazardous Materials Technical Memorandum
Appendix H. Hydrology Technical Memorandum
Appendix I. Noise and Vibration Assessments
Appendix J. Transportation Assessment
Appendix K. LACSD Will Serve Letter
Figures
Figure 1. Project vicinity. .............................................................................................................................. 2 Figure 2. Project location. ............................................................................................................................. 3 Figure 3. Site plan. ........................................................................................................................................ 6 Figure 4. Site access. ..................................................................................................................................... 8 Figure 5. Fire Hazard Severity Zones for Local and State Responsibility Areas in a 1-mile radius from the project site. ................................................................................................................ 96
Tables
Table 1. Project Components Summary ....................................................................................................... 5 Table 2. Proposed Buildout by Planning Area .............................................................................................. 7 Table 3. SCAQMD Air Quality Significance Thresholds .......................................................................... 18 Table 4. Localized Significance Thresholds for Source-Receptor Area 13 (Santa Clarita Valley) ............ 19 Table 5. Estimated Maximum Daily Construction Criteria Air Pollutant Emissions ................................. 21 Table 6. Estimated Maximum Daily Operation Criteria Air Pollutant Emissions ...................................... 22 Table 7. Localized Significance Thresholds Analysis for the Project (Prior to Application of MM AIR-1) ...................................................................................................................................... 24 Table 8. Estimated Annual Operation GHG Emissions .............................................................................. 52 Table 9. Population and Employment Growth Forecast for the City of Santa Clarita ................................ 75 Table 10. Mitigation and Monitoring Program ......................................................................................... 110
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Draft Final Initial Study/Mitigated Negative Declaration iii
ACRONYMS AND ABBREVIATIONS
°F degrees Fahrenheit
µg/m3 micrograms per cubic meter
AB Assembly Bill
Alquist-Priolo Act Alquist-Priolo Earthquake Fault Zoning Act amsl above mean sea level
APN Accessor’s Parcel Number
Applicant Riverview Owner LPV, LCC
AQMP Air Quality Management Plan
Basin Plan Water Quality Control Plan for the Los Angeles Basin BMP best management practice
CAAQS California Ambient Air Quality Standards
CalEEMod California Emissions Estimator Model
CalEPA California Environmental Protection Agency
CAL FIRE California Department of Forestry and Fire Protection CALGreen California Green Building Standards Code
Caltrans California Department of Transportation
CAP Climate Action Plan
CAPCOA California Air Pollution Control Officers Association CARB California Air Resources Board
CBC California Building Code
CCR California Code of Regulations
CDFW California Department of Fish and Wildlife
CDOC California Department of Conservation
CEQA California Environmental Quality Act
CFR Code of Federal Regulations
CH4 methane
CHRIS California Historical Resources Information System City City of Santa Clarita
CNEL Community Noise Equivalent Level
CO carbon monoxide
CO2 carbon dioxide
CO2e carbon dioxide equivalents
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Draft Final Initial Study/Mitigated Negative Declaration iv
CRHR California Register of Historical Resources
dB decibel(s)
dBA A-weighted decibel(s)
Design Guidelines City of Santa Clarita Community Character and Design Guidelines DTSC Department of Toxic Substances Control
DWR California Department of Water Resources
EPA U.S. Environmental Protection Agency
FAR floor area ratio
Farmland Prime Farmland, Unique Farmland, or Farmland of Statewide Importance FEMA Federal Emergency Management Agency
FHSZ Fire Hazard Severity Zone
FTA Federal Transit Administration
GeoSoils GeoSoils Consultants, Inc.
GHG greenhouse gas
HVAC heating, ventilation, and air conditioning
I- Interstate
in/sec inch per second
IS Initial Study
IS/MND Initial Study/Mitigated Negative Declaration
JCOZ Jobs Creation Overlay Zone
LACDPW Los Angeles County Department of Public Works
LACFD Los Angeles County Fire Department
Ldn day-night average sound level
Leq hourly average
LOS level of service
LST localized significance threshold
MBTA Migratory Bird Treaty Act
mgd million gallons per day
MM Mitigation Measure
MND Mitigated Negative Declaration
MRZ Mineral Resource Zone
MS4 Municipal Separate Storm Sewer System
MT metric tons
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration v
MTCO2e metric tons of carbon dioxide equivalents
MXC Mixed Use Corridor
N2O nitrous oxide
NAAQS National Ambient Air Quality Standards
NAHC Native American Heritage Commission
Ninyo and Moore Ninyo and Moore Geotechnical and Environmental Sciences Consultants NO2 nitrogen dioxide
NOx oxides of nitrogen
NPDES National Pollution Discharge Elimination System
NRCS Natural Resources Conservation Service
NRHP National Register of Historic Places
O3 ozone
OEHHA Office of Environmental Health Hazard Assessment
OPR Governor’s Office of Planning and Research
PA/Lot planning area/lot
PEA preliminary endangerment assessment
Plan Cultural Resource Monitoring and Inadvertent Discovery Plan PM10 coarse particulate matter
PM2.5 fine particulate matter
ppm parts per million
PPV peak particle velocity
PRC California Public Resources Code
project Riverview Development project
RHNA Regional Housing Needs Allocation
RTP/SCS Regional Transportation Plan/Sustainable Communities Strategy RV recreational vehicle
RWQCB Regional Water Quality Control Board
S.A.F.E. Solvents/Automotive/Flammables/Electronics
SB Senate Bill
SCAB South Coast Air Basin
SCAG Southern California Association of Governments
SCAQMD South Coast Air Quality Management District
SCCIC South Central Coast Information Center
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Draft Final Initial Study/Mitigated Negative Declaration vi
SCE Southern California Edison
SCUDC Santa Clarita Unified Development Code
SCV-GSA Santa Clarita Valley Groundwater Sustainability Agency SCV Water Santa Clarita Valley Water Agency
SEMS Superfund Enterprise Management System
SoCalGas Southern California Gas Company
STC sound transmission class
SOx sulfur oxides
SR State Route
SRA source-receptor area
SVP Society of Vertebrate Paleontology
SWPPP Stormwater Pollution Prevention Plan
SWRCB State Water Resources Control Board
TAC toxic air contaminant
USFWS U.S. Fish and Wildlife Service
USGS U.S. Geological Survey
UWMP Urban Water Management Plan
VMT vehicle miles traveled
VOC volatile organic compound
WEAP Worker Environmental Awareness Program
WRP wastewater reclamation plant
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 1 1 INTRODUCTION
The Riverview Owner LPV, LCC (Applicant), is proposing to develop the Riverview Development project (project) in the city of Santa Clarita, California, which requires review under the California Environmental Quality Act (CEQA). This Initial Study/Mitigated Negative Declaration (IS/MND) evaluates the environmental effects of the project. The project would include the construction of 318 single-family units and a 126,790square foot building designated for light manufacturing use on a 35.2-acre property.
1.1 California Environmental Quality Act
CEQA (California Public Resources Code [PRC] Section 21000 et seq.), as amended, applies to proposed projects initiated by, funded by, or requiring discretionary approvals from state or local government agencies. The State CEQA Guidelines (Title 14, Section 15000 et seq. of the California Code of Regulations [CCR]), as revised) states that a “lead agency” is “the public agency which has the principal responsibility for carrying out or approving a project.” Therefore, the City of Santa Clarita (City) is the Lead Agency responsible for compliance with CEQA for the proposed project.
As Lead Agency, the City must complete an environmental assessment of the project to determine whether implementation of the project would result in significant adverse environmental impacts.
To fulfill the purpose of CEQA, this Initial Study (IS) has been prepared to consider the potential environmental impacts the project could cause.
Based on the nature and scope of the proposed project and the evaluation contained in the IS environmental checklist (contained herein), the City, as the Lead Agency, concluded that a Mitigated Negative Declaration (MND) is the proper level of environmental documentation for this project. The IS shows that impacts caused by the proposed project are either less than significant or significant but mitigable with incorporation of appropriate mitigation measures as defined herein. This conclusion is supported by State CEQA Guidelines Section 15070, which states that an MND can be prepared when “(a) the initial study shows that there is not substantial evidence, in light of the whole record before the agency, that the project may have a significant effect on the environment, or (b) the initial study identifies potentially significant effects, but (1) revisions in the project plans or proposals made by, or agreed to by the applicant, before a proposed mitigated negative declaration and initial study are released for public review would avoid the effects or mitigate the effects to a point where clearly no significant effects would occur; and (2) there is no substantial evidence, in light of the whole record before the agency, that the project as revised may have a significant effect on the environment.”
1.2 Project Location and Environmental Setting
The project site is located in the city of Santa Clarita, Los Angeles County, California (Figure 1). The site is south of Soledad Canyon Road and encompasses 35.2 acres (Figure 2). The address of the site is 22500 Soledad Canyon Way. The Assessor’s Parcel Number [APN] is 2836-011-018 and the site can be found within Section 23, Township 4 North, Range 16 West, as shown on the Newhall, California, U.S.
Geological Survey (USGS) 7.5-minute quadrangle.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 2 Figure 1. Project vicinity.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 3 Figure 2. Project location.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 4 The project site is located on the former Saugus Speedway in the City of Santa Clarita, and is bordered by Soledad Canyon Road to the north, Commuter Way to the east, and a Southern Pacific Railroad line to the south, which is used by the Los Angeles Metropolitan Transportation Authority, Metrolink.
The Metrolink Santa Clarita station is located adjacent to the project site and is shown in Figure 2. The project site is generally flat, with the exception of the northwestern portion of the site, which includes hillside terrain with native vegetation. The elevation across the project site ranges from approximately 1,185 to 1,295 feet above mean sea level (amsl) (GeoSoils Consultants, Inc. [GeoSoils] 2022). The project site is currently occupied by a decommissioned speedway track and associated structures and is now used primarily as the Santa Clarita Swap Meet, which is hosted every Tuesday and Sunday. The first outdoor market was held in 1963. The speedway was retired in 1995 due to decaying facilities and the grandstands were later demolished in 2012. The majority of the project site is paved with asphalt.
Surrounding land uses include the Santa Clara River and floodplain followed by residential to the north and northeast, commercial to the southeast and northwest, Metrolink rail stop and undeveloped hillsides to the south, and a family counseling center to the northwest.
The Santa Clarita region has a Mediterranean climate with cool, wet winters and hot, dry summers.
August is the average warmest month with an average high temperature of 92 degrees Fahrenheit (°F) and December is the coolest month on average with a low of 42°F. Rainfall occurs primarily between October and April, with the maximum average precipitation in January. The mean annual rainfall for the region is approximately 17.35 inches of rain per year (Los Angeles County Department of Public Works [LACDPW] 2022). Soils in the project site are characterized as a mix of Hanford series soils, river wash, sandy alluvial land, and the Saugus series soils (Natural Resources Conservation Service [NRCS] 2023).
The depth to groundwater on the project site ranges between approximately 20 to 30 feet below ground surface, and groundwater flow direction is toward the west-northwest (Dudek 2022). Yearly variation in depth to groundwater is common in the area where the project site is located; groundwater in this area is highly dependent on precipitation and recharge from the nearby Santa Clara River.
1.3 General Plan and Zoning Designations
As identified in the City of Santa Clarita General Plan, the project site has the land use and zoning designation of Mixed Use Corridor (MXC) and is within the Jobs Creation Overlay Zone (JCOZ).
The MXC zone is intended for mixed-use development along specified commercial corridors in which revitalization of underutilized parcels or aging buildings is encouraged. Mixed uses in the MXC may be either vertical or horizontal, provided that residential uses in these areas should be protected from high-volume arterial streets and should typically be located an appropriate distance from the roadway.
Non-residential uses consistent with the MXC zone include those in the Neighborhood Commercial (CN) and Community Commercial (CC) districts. The residential density range in this zone is between 11 to 30 dwelling units per acre, and maximum floor area ratio for the non-residential portion of the development is 1.0.
The purpose of the JCOZ is to support the General Plan objective of promoting the creation of strong regional and local economies via the implementation of strategic land use planning policies. Specifically, the JCOZ intends to 1) attract and promote the creation of high-quality jobs within the City’s four targeted industries—aerospace, biomedical, entertainment, and technology—and other industries at the discretion of the Director; 2) enhance the city’s overall jobs/housing balance; and 3) provide greater employment opportunities throughout the entire city.
The project site is identified as a Suitable Site (Housing Site 23) in the Housing Element of the General Plan. A Suitable Site is a site that may be feasibly developed for housing to meet the Regional Housing Needs Allocation (RHNA). The project site is suitable for very lower and moderate income units.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 5 1.4 Project Description
1.4.1 Project Overview
The Applicant proposes construction and operation of a mixed-use development with 318 single-family units and 126,790 square foot building that would be used by a light manufacturing tenant on an approximately 35.2-acre site (APN 2836-011-018). Table 1 provides a summary of project components, and each component is described further below.
Table 1. Project Components Summary
Project Component Description
Proposed Buildout
Single-family residential units 318 single-family residential units Manufacturing use 126,790 square feet of a light manufacturing use (one large building) Access, Circulation, Parking
Site access Access via four driveways along Soledad Canyon Road: two driveways for residential uses and two for the manufacturing use
Parking spaces and structure 819 residential parking spaces and 219 parking spaces for the light manufacturing use
Grading
Cut and fill Approximately 500,000 cubic yards of cut and 420,000 cubic yards of fill Utility Improvements
Sewer connections Site connection into County Los Angeles County Sanitation District Drainage basins Four drainage basins for stormwater management are proposed, one at the southern border of PA-4/Lot-4 and PA-3/Lot-3, one at the southern border of PA-3/Lot-3, one at the southern border of PA-2/Lot-2 and one between PA-4/Lot-4 and the manufacturing portion of the site (Lot 5).
Off-site Improvements
Transit improvements Bus stop along eastbound Soledad Canyon Road, including a permanent shelter structure with a bench, trash receptacle, and lighting
A new bus turnout along Soledad Canyon Road with a pedestrian path from the project site to the bus stop
Street improvements Curbs and gutters, base paving, and 5-foot minimum sidewalks along Soledad Canyon Road and Commuter Way, as well as modification of the Soledad Canyon Road median
The existing Southern California Edison–owned streetlights along Soledad Canyon Road and Commuter Way would be removed and replaced with current City standard streetlights
Telecommunications conduit Telecommunications conduit for the installation or future installation of fiber-optic cable along Soledad Canyon Road
1.4.2 Proposed Buildout
Figure 3 shows a general site plan for the project. The project site would be split into five planning areas/lots (PA/Lots). PA/Lots 1, 2, 3, and 4 are located on the southeast two-thirds of the parcel and would be dedicated to residential development, including landscaping improvements, recreational amenities, and a community open space area.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 6 Figure 3. Site plan.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 7 Planning area/Lot 5 is located on the northwest one-third of the parcel and would be dedicated to a 126,790square foot building that would be used by a light manufacturing tenant. A total of 1,038 parking spaces would be provided, with 819 for residential uses and 219 for the light manufacturing building.
Table 2 provides a summary of the project’s proposed buildout by planning area Table 2. Proposed Buildout by Planning Area
Planning Area/Lot Acreage Proposed Use Type Proposed Buildout Parking Spaces PA-1 8.64 Single Family Residential Attached
11 dwelling units per acre)
95 units 239
PA-2 5.45 Single Family Residential Detached 60 units 162 PA-3 5.64 Single Family Residential Detached 62 units 157 PA-4 9.18 Single Family Residential Attached 101 units 261 Residential Total 28.91 acres 318 units 819
PA-5 6.49 Light Manufacturing Building 126,790 square feet (including 10,000
square feet of
office/mezzanine space)
219
1.4.3 Access, Circulation, and Parking
Vehicular access to the residential portion of the project site would be provided by three proposed driveways along Soledad Canyon Road (Figure 4). The westerly residential driveway and center driveways would allow right and left turns into the residential portions of the project site, but only allow for and right turns out of the project site. The center residential driveway would allow right and left turns into the residential portion of the project site and right turns out of the project site. The easterly driveway would be a full access, signalized driveway at Commuter Way and Soledad Canyon Road, which would be shared with the traffic to and from the adjacent Santa Clarita Metrolink Station.
Vehicular access to the light manufacturing land use would be accessed via a main driveway at the northeast corner of PA-5/Lot-5 with a secondary right-turn in-and-out driveway at the northwest corner of PA-5/Lot-5.
All driveways providing access to the site would be 36 feet wide, and internal driveways would be 28 feet wide. Driveways and drive aisles serving trucks and other large vehicles would be wider as necessary to accommodate these vehicles. Sidewalks would be provided on all internal roadways that are not alley-type driveways.
A total of 819 parking spaces would be provided for the residential portions of the site.
The manufacturing portion of the project site would provide 219 parking spaces including 44 electric vehicle spaces and 2 parking spaces for truck trailers. Clean Air Vehicle parking spaces and electric vehicle charging stations would be provided for both commercial and residential portions of the site.
Short- and long-term bicycle parking would be provided for the commercial portions of the site, as required by the City. City standards indicate that bicycle parking spaces would be provided at minimum a ratio of one space per 25 vehicle parking stalls for nonresidential components, and one space per five units for residential components.
Pedestrian access would be provided by the existing sidewalk along Soledad Canyon Road. The sidewalk would connect to the proposed driveways, which lead into the residential portion of the project site.
Within the residential area, internal pathways would be located throughout the project site connecting to a series of open space and community recreation amenities, such as a central community lawn, a dog park, a community garden area, seating nooks, and reading areas.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 8 Figure 4. Site access.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 9 Access to the Metrolink Station would be provided via a pedestrian pathway connecting to Commuter Way. A new bus turnout along Soledad Canyon Road would be provided at a proposed bus stop, as well as a pedestrian path from the project site to the bus stop. Other street improvements include curbs and gutters, base paving, and 5-foot minimum sidewalks along Soledad Canyon Road and Commuter Way.
1.4.4 Landscaping
The development of the project site would include extensive landscaping consistent with those typical to support a residential community and a light manufacturing land use. The project design includes a landscaping plan, which provides for vegetation, plantings, amenities, and design features that would be included in the development. Features of the landscaping plan include, but are not limited to, community recreation areas, a dog park, shade structures, playgrounds, pool facilities, and the provision for a range of plant and tree species, which would be planted throughout the project site. In total, the landscaping plan shows that 647 trees would be planted, in addition to various shrubs, grasses, and groundcovers.
1.4.5 Utility and Drainage Improvements
The project would involve construction of new utility lines, connection to existing utilities, and off-site improvements to upgrade utility infrastructure. The project would be served by the following public utilities:
• Water – Santa Clarita Valley Water Agency
• Sewer – Los Angeles County Sanitation District
• Electric – Southern California Edison (SCE)
• Gas – Southern California Gas Company (SoCalGas)
• Telephone – AT&T
• Cable TV – Charter Communications
The project would connect to the Los Angeles County Sanitation District trunk sewer in Soledad Canyon Road. Prior to issuance of the first building permit, the site would be required to be annexed into the County Sanitation District, per the Development Review Committee Comments (City of Santa Clarita 2022a). The on-site sewer would be publicly maintained.
The project would also involve construction of a new telecommunications conduit for the installation or future installation of fiber-optic cable due to street improvements associated with the project along Soledad Canyon Road.
Four drainage basins for stormwater management are proposed, one at the southern border of PA-4/Lot-4 and PA-3/Lot-3, one at the southern border of PA-3/Lot-3, one at the southern border of PA-2/Lot-2 and one between PA-4/Lot-4 and the manufacturing portion of the site (Lot 5).
1.4.6 Grading
The project would require approximately 500,000 cubic yards of cut and approximately 420,000 cubic yards of fill. Grading would consist of lowering the isolated hill area at the western part of the site and raising most of the remaining site. The hilltop would be lowered by up to 100 feet and the area to the east would be raised by up to approximately 10 to 11 feet. Cut slopes at a gradient of 2:1 are proposed at the southern side of the site to a maximum height of approximately 25 feet. Fill slopes are proposed at a Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 10 gradient of 2:1 to a maximum height of approximately 10 feet. A 5-foot-high retaining wall is proposed along the northern part of the site, south of Soledad Canyon Road.
1.4.7 Lighting
Exterior lighting would be subject to compliance with the Santa Clarita Municipal Code (Section
17.51.050), which requires all lights to be directed downward and be of a cut-off design to prevent illumination of other properties and off-site glare. In addition, the Municipal Code requires that all light fixtures at building entrances be on between sundown and 10 p.m. or 1 hour past the close of the business.
All outdoor lighting would be required to be off between the hours of 10 p.m. and sunrise, except where uses are in operation past 10 p.m.
1.4.8 Off-site Improvements
Off-site improvements would be needed to upgrade transportation and utility infrastructure along Soledad Canyon Road and Commuter Way and accommodate the project and its proposed uses. The project would encourage transit use and provide a bus stop along eastbound Soledad Canyon Road, including a permanent shelter structure with a bench, trash receptacle, and lighting. A new bus turnout along Soledad Canyon Road would also be provided at the proposed bus stop. The bus turnout would be located and designed per Transit Division specifications. The bus stop may require construction in a City right-of-way as approved by the City Engineer. A pedestrian path from the project site to the bus stop would also be provided. Other street improvements include curbs and gutters, base paving, and 5-foot minimum sidewalks along Soledad Canyon Road and Commuter Way, as well as modification of the Soledad Canyon Road median.
Streetlights would be provided along Soledad Canyon Road and Commuter Way per the Applicant’s Street Light Plan, as approved by the City’s Engineering Services Division. Street lighting systems would be required to use light-emitting diode (LED) fixtures approved by the City’s Streetlight Maintenance District Division to maximize efficiency. The existing SCE-owned streetlights along Soledad Canyon Road and Commuter Way would be removed and replaced with current City standard streetlights. As described above, the project would also construct a new telecommunications conduit for the installation of fiber-optic cable along Soledad Canyon Road.
1.4.9 Construction Schedule and Equipment
The project would involve demolition of existing on-site structures, site preparation and grading, building construction, utility and infrastructure improvements, paving, and landscaping. It is anticipated that the project site would begin to be prepared and graded in late 2024, with this phase of construction concluded by December 2025. Building construction would begin in 2026 and be phased over four to five years, depending on market conditions.
1.5 Required Discretionary Approvals
The City has the primary authority over the project’s discretionary approvals. Permits and approvals required for implementation include the following:
• Architectural Design Review approval to ensure compliance with the City’s architectural standards.
• Conditional Use Permit approval to permit light manufacturing in the MXC zone.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 11 • Development Review approval to review the proposed development, including the site plan. • Landscape Plan Review approval to ensure the project conforms with the City’s landscaping standards.
• Hillside Development Review Class II approval to review the proposed development on parcels that have an average cross slope of 10 to 15 percent.
• Minor Use Permits (for both the residential and manufacturing components). • Oak Tree Permit Class IV approval to manage the removal of nine oak trees including one Heritage Oak.
• Tentative Tract Map approval to allow new lots and/or condominium units.
In addition, the South Coast Air Quality Management District (SCAQMD) could require air permits for new stationary emission sources and portable equipment, if the equipment requires air permits. The project would be required to comply with all applicable SCAQMD rules and permitting requirements prior to operating. If a permit is required from SCAQMD for project equipment or features, the agency would be considered a Responsible Agency for the project.
1.6 Intended Uses of this Document
The intent of this IS/MND is to 1) determine whether project implementation would result in potentially significant or significant impacts on the physical environment, and 2) incorporate mitigation measures into the project design, as necessary, to eliminate the project’s potentially significant impacts or reduce them to a less-than-significant level.
This document is intended to facilitate public involvement in the planning process by providing opportunities for public review and comment on the project. When the Lead Agency is a State agency or the project is of Statewide concern, the public review period shall be as long as the review period established by the State Clearinghouse, which is normally 30 days. Given the Lead Agency for this project is the City of Santa Clarita and not a State agency, this IS/MND will be circulated for at least 20 days for public and agency review, during which time individuals and agencies may submit comments on the adequacy of the environmental review. Following the public review period, the City will consider any comments received on the IS/MND when deciding whether to adopt the document.
Riverview Development Project
Final Initial Study/Mitigated Negative Declaration
12 2 ENVIRONMENTAL CHECKLIST AND ENVIRONMENTAL
EVALUATION
ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED
The proposed project could have a “potentially significant impact” for environmental factors checked below. Please refer to the attached pages for discussion on mitigation measures or project revisions to either reduce these impacts to less-than-significant levels or to require further study. ☐ Aesthetics ☐ Greenhouse Gas Emissions ☐ Public Services ☐ Agriculture and Forestry
Resources ☒ Hazards and Hazardous
Materials
☐ Recreation
☒ Air Quality ☐ Hydrology and Water Quality ☐ Transportation ☒ Biological Resources ☐ Land Use and Planning ☒ Tribal Cultural Resources ☒ Cultural Resources ☐ Mineral Resources ☐ Utilities and Service Systems ☐ Energy ☒ Noise ☐ Wildfire
☒ Geology and Soils ☐ Population and Housing ☐ Mandatory Findings of Significance
ENVIRONMENTAL DETERMINATION
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
DECLARATI
ON 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 t
he project have been made by or agreed to by the project proponent.
A MITIG
ATED 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.
☐ I find that the proposed project MAY have a “potentially significant impact” or “potentially significant unless mitigated” impact on the en
vironment, but at least one effect 1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and 2) has been addressed by mitigation measure based on the earlier analysis as described on atta
ched sheets. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects that remai
n 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 be
en analyzed adequately in an earlier ENVIRONMENTAL IMPACT REPORT (EIR) or
NEGATIVE
DECLARATION pursuant to applicable standards, and (b) have been avoided or mitigated pursuant to that earlier EIR or
NEGATIVE DECLARATION, including revisions or mitigation measures that are imposed upon the proposed p
roject, nothing further is required.
Date: Signed: 10/8/24
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 13 I. Aesthetics
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
Except as provided in PRC 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 a 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? ☐ ☐ ☒ ☐
Setting
The project site is located within the jurisdictional boundaries of the City of Santa Clarita on a site that was historically a speedway racetrack. The visual character of the project site is dominated by concrete and asphalt paved parking lots and a decommissioned speedway. Ancillary structures such as concession stands, office buildings, and horse stables are located across the project site. Trees border the perimeter of the speedway and are sparsely located throughout the parking lots and along Soledad Canyon Road.
The northeastern extent of the project site is an undeveloped lone hill, covered in sparse scrub vegetation.
To the north of the project site across Soledad Canyon Road is the Santa Clara River, which is braided and supports riparian vegetation. The Santa Clara River floodplain is approximately 1,000 feet across at its widest point adjacent the project site. The project site is immediately surrounded by undeveloped land to the south and the Santa Clarita Metrolink Station and the Villa Metro housing development to the east.
Undeveloped hillsides dominate the visual landscape to the southwest of the project site.
Environmental Evaluation
a) Would the project have a substantial adverse effect on a scenic vista? Less than Significant Impact. Scenic vistas generally refer to views of expansive open space or other natural features, such as mountains, undeveloped hillsides, large natural water bodies, or coastlines.
Scenic vistas generally refer to views that are accessible from public vantage points, such as public roadways and parks. The city is aesthetically characterized by scenic mountains and canyons, including backdrops, hillsides, and ridgelines. These landforms are considered important components of the city’s scenic views. However, the City’s General Plan Conservation Element does not specifically list any local scenic vistas (City of Santa Clarita 2011a). The City also designates certain ridgelines subject to development restrictions. There are no such protected ridgelines within the project site (City of Santa Clarita 2023). The project would involve the alteration of a hill located at the northwestern portion of the parcel, with the reduction of approximately 100 feet in height to accommodate the manufacturing portion of the project. The view from Soledad Canyon Road would be altered by the removal of this hill, however the City does not consider the existing site to be a scenic vista. The alteration of this hill would not change the viewshed significantly, as the project site is framed by mountainous landscape on the far side Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 14 of the railroad tracks. The proposed project would not affect a scenic vista and therefore 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 officially designated state scenic highway is a portion of State Highway 2 that extends through the San Gabriel Mountains, beginning just north of the city of La Cañada Flintridge (California Department of Transportation [Caltrans] 2019). The portion of State Highway 2 that is officially designated as a State Scenic Highway is located approximately 22 miles southeast of the project site. The nearest eligible state scenic highway is Interstate 5, which is approximately 2.6 miles west of the project site. Due to distance and intervening development/topography, the project site is not within the viewshed of a State Scenic Highway, and the proposed project would not substantially affect any scenic resources within State Highway 2 or Interstate 5. Therefore, no impact on scenic resources within a state scenic highway would occur as a result of the proposed project. 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 a 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?
No Impact. Per PRC Section 21071, an “urbanized area” is defined as “(a) An incorporated city that meets either of the following criteria: (1) Has a population of at least 100,000 persons [or] (2) Has a population of less than 100,000 persons if the population of that city and not more than two contiguous incorporated cities combined equals at least 100,000 persons.” Because Santa Clarita is an incorporated city that has a population that exceeds 100,000 persons, the project site is located within an urbanized area. Therefore, pursuant to this threshold, a potentially significant impact to visual character only would occur if the project were to conflict with applicable and/or other City of Santa Clarita regulations governing scenic quality.
Implementation of the project would result in the visual conversion of the site from parking lots and a speedway, to a housing development and manufacturing building with associated parking, access roads, utility infrastructure, landscaping, exterior lighting, and signage. The project would be compatible with the size, scale, and aesthetic/decorative architectural and landscaping features of other existing high- density housing subdivisions constructed to the north and east of the project site. Furthermore, the project would be required to comply with the applicable development standards and design guidelines contained in the Santa Clarita Zoning Ordinance, which regulates the visual quality of new development and ensures that new development does not detract from any scenic attributes/qualities in the surrounding area.
Because the project would be developed in an area that is generally urbanized and the project would not conflict with applicable regulations governing scenic quality, 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?
Less than Significant Impact. The project is located within an urbanized area with moderate levels of ambient lighting, including street lighting, vehicle headlights, architectural and security lighting, and indoor building illumination, all of which are common to densely populated areas.
Under existing conditions, the project site contains lights in the parking lot and stadium-style light towers at the speedway. The lights are used as needed during events are hosted at the speedway. In addition, streetlights are present along the project site’s frontage with Soledad Canyon Road. The Applicant Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 15 proposes to develop the site with a subdivision including 318 individual residential units and a 126,790square foot manufacturing building, 10,000 square feet of which would be dedicated to office space. New lighting elements to illuminate parking areas, building entrances, and residential uses would be introduced to the project site.
The development would be required to comply with lighting requirements as set forth in the City of Santa Clarita Municipal Code Section 17.51.050. All lights would be required to be directed downward and be of a cut-off design to prevent illumination of other properties and off-site glare. In addition, the Municipal Code requires that all light fixtures at building entrances be on between sundown and 10 p.m. or 1 hour past the close of the business. Outdoor lighting would be required to be off between the hours of 10 p.m. and sunrise, except where uses are in operation past 10 p.m. Mandatory compliance with the Municipal Code would ensure that the project would not introduce any permanent design features that would adversely affect day or nighttime views in the area. This impact would be less than significant.
With respect to glare, a majority of project building materials would consist of concrete panels, which are non-reflective. While window glazing has a potential to result in minor glare effects, such effects would not adversely affect daytime views of surrounding properties, including motorists along adjacent roadways, because proposed buildings would be set back from adjacent roadways at a distance, and proposed landscaping would provide a buffer between all proposed glass surfaces and the public right-of- way. Thus, glare impacts from proposed building elements would be less than significant.
Conclusion
The project would not result in a significant adverse impact to aesthetics; no mitigation measures are necessary.
II. Agriculture and Forestry Resources
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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 Department of 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 state’s inventory of forest 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 PRC Section 12220(g)),
timberland (as defined by PRC 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?
☐ ☐ ☐ ☐
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 16 Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
(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?
☐ ☒ ☐ ☒
Setting
The project site is designated Urban Built-Up Land classification by the Farmland Mapping and Monitoring Program (California Department of Conservation [CDOC] 2018). The project site is not located on land designated as Williamson Act contract land and is not designated or zoned as agricultural land. Additionally, the project site is not located on land designated as forest land or timberland and is not currently used for agricultural purposes.
Environmental Evaluation
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 is not within Prime Farmland, Unique Farmland, or Farmland of Statewide Importance, according to the CDOC’s Farmland Monitoring and Mapping Program (CDOC 2018).
The Farmland Monitoring and Mapping Program designates the project site as “Urban and Built-Up Land.” Examples of Urban and Built-Up Land include commercial, residential, industrial, airports, institutional facilities, golf courses, cemeteries, sewage treatment, water control structures, and sanitary landfills. No conversion of Prime Farmland, Unique Farmland, or Farmland of Statewide Importance to non-agricultural use would take place within the project site. Thus, no impact would occur, and no mitigation measures are necessary.
b) Would the project conflict with existing zoning for agricultural use, or a Williamson Act contract?
No Impact. As previously noted, the project site is zoned as MXC. No land is zoned for forest land, timberland, or Timberland Production within or near the project site. Therefore, the project would not conflict with existing zoning, or cause the rezoning of, forest land, timberland, or timberland zoned Timberland Production. No impact would occur, and no mitigation measures are necessary. c) Would the project conflict with existing zoning for, or cause rezoning of, forest land (as defined in PRC Section 12220(g)), timberland (as defined by PRC Section 4526), or timberland zoned Timberland Production (as defined by Government Code Section 51104(g))?
No Impact. As stated in the response above, the project site is zoned as MXC. No land is zoned for forest land, timberland, or Timberland Production within or near the project site. Therefore, the project would not conflict with existing zoning, or cause the rezoning of, forest land, timberland, or timberland zoned Timberland Production. No impact would occur, and no mitigation measures are necessary.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 17 d) Would the project result in the loss of forest land or conversion of forest land to non-forest use?
Less than significant impact. The project site is previously developed and does not support forest land on-site. Trees are located around the speedway providing intermittent shade, and along Soledad Canyon Road. There are 10 protected oak trees on the project site. Nine of the 10 oak trees are proposed for removal, including one Heritage Oak; an Oak Tree Permit Class IV approval would be acquired for their removal. As part of the project design, approximately 647 new trees would be planted throughout the subdivision and surrounding community areas. With the removal of sparse trees, and planting of new trees as part of project landscaping, the project would not result in the loss of forest land or conversion of forest land to non-forest use, and impacts would be less than significant. 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. The project site is not zoned for agricultural use and no agricultural activities occur on-site or within the project vicinity. Additionally, the project site is not zoned for forest land and there are no forestry operations occurring on-site or within the project vicinity. Therefore, no Farmland or forest land would be converted or otherwise affected by the project. No impact would occur, and no mitigation measures are necessary.
Conclusion
The project would not result in a significant adverse impact to agriculture and forestry resources; no mitigation measures are necessary.
III. Air Quality
Environmental Issues
Potentially
Significant
Impact
Less Than Significant
with Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
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?
☐ ☐ ☒ ☐
(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 for this section is based on the Air Quality, Energy, and Greenhouse Gas Technical Memorandum for the Riverview Development in Santa Clarita, California (LSA 2024a) and the Health Risk Assessment for the Riverview Development in Santa Clarita, California (LSA 2024b) which are both included in Appendix A.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 18 Setting
The project site is located within the South Coast Air Basin (SCAB), which includes all of Orange County and the urban portions of Los Angeles, Riverside, and San Bernardino Counties. Air quality in the SCAB is regulated by the South Coast Air Quality Management District (SCAQMD). The SCAQMD has adopted thresholds to address the significance of air quality impacts resulting from a project. A project would result in a substantial contribution to an existing air quality violation of the National Ambient Air Quality Standards (NAAQS) or California Ambient Air Quality Standards (CAAQS) for ozone (O 3), which is a
nonattainment pollutant, if the project’s construction mass emissions would exceed SCAQMD’s volatile organic compound (VOC) or oxides of nitrogen (NO x) significance thresholds (Table 3).
Table 3. SCAQMD Air Quality Significance Thresholds
Criteria Pollutants Mass Daily Thresholds
Pollutant Construction (pounds per day) Operation (pounds per day) VOCs 75 55
NOx 100 55
CO 550 550
SOx 150 150
PM10 150 150
PM2.5 55 55
Lead* 3 3
Toxic Air Contaminants and Odor Thresholds
TACs† Maximum incremental cancer risk ≥ 10 in 1 million Cancer burden > 0.5 excess cancer cases (in areas ≥ 1 in 1 million) Chronic and acute hazard index ≥ 1.0 (project increment) Odor Project creates an odor nuisance pursuant to SCAQMD Rule 402 Ambient Air Quality Standards for Criteria Pollutants‡
NO2 1-hour average
NO2 annual arithmetic mean
SCAQMD is in attainment; project is significant if it causes or contributes to an exceedance of the following attainment standards:
0.18 ppm (state)
0.030 ppm (state) and 0.0534 ppm (federal)
CO 1-hour average
CO 8-hour average
SCAQMD is in attainment; project is significant if it causes or contributes to an exceedance of the following attainment standards:
20 ppm (state) and 35 ppm (federal)
9.0 ppm (state /federal)
PM10 24-hour average
PM10 annual average
10.4 µg/m3 (construction)§
2.5 µg/m3 (operation)
1.0 µg/m3
PM2.5 24-hour average 10.4 µg/m3 (construction)§
2.5 µg/m3 (operation)
Source: SCAQMD (2019).
Notes:
SCAQMD = South Coast Air Quality Management District; VOCs = volatile organic compounds; NOx = oxides of nitrogen; CO = carbon monoxide; SOx = sulfur oxides; PM10 = coarse particulate matter; PM2.5 = fine particulate matter; TAC = toxic air contaminant; NO2 = nitrogen dioxide; ppm = parts per million; µ/m3 = micrograms per cubic meter.
Greenhouse gas (GHG) emissions thresholds for industrial projects, as added in the March 2015 revision to the SCAQMD Air Quality Significance Thresholds, were not include included in this table as they are addressed within the GHG emissions analysis and not the air quality study. * = The phaseout of leaded gasoline started in 1976. Since gasoline no longer contains lead, the project is not anticipated to result in impacts related to lead; therefore, it is not discussed in this analysis.
† = TACs include carcinogens and non-carcinogens.
‡ = Ambient air quality standards for criteria pollutants are based on SCAQMD Rule 1303, Table A-2, unless otherwise stated. § = Ambient air quality threshold is based on SCAQMD Rule 403.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 19 These emission -based thresholds for O 3 precursors are intended to serve as a surrogate for an “ozone significance threshold” (i.e., the potential for adverse O 3 impacts to occur) because O 3 itself is not emitted directly, and the effects of an individual project’s emissions of O 3 precursors (VOCs and NOx) on O3 levels in ambient air cannot be determined through air quality models or other quantitative methods. The SCAB is also nonattainment for the state coarse particulate matter (PM 10) and federal and state fine particulate matter (PM 2.5) standards.
In addition to the emission-based thresholds listed in Table 3, SCAQMD also recommends the evaluation of localized air quality impacts to sensitive receptors in the immediate vicinity of the project site as a result of construction activities. Such an evaluation is referred to as a localized significance threshold (LST) analysis.
SCAQMD published its Final Localized Significance Threshold Methodology in July 2008, recommending that all air quality analyses include an assessment of air quality impacts to nearby sensitive receptors.8 This guidance was used to analyze potential localized air quality impacts associated with construction of the proposed project. Localized significance thresholds (LSTs) are developed based on the size or total area of the emission source, the ambient air quality in the source-receptor area (SRA), and the distance to a project site. LSTs are based on the ambient concentrations of that pollutant within the project SRA and the distance to the nearest sensitive receptor. For the proposed project, the appropriate SRA for the LST is the Santa Clarita Valley area (SRA 13). SCAQMD provides LST screening tables for 25, 50, 100, 200, and 500-meter source-receptor distances. The nearest sensitive receptor land use is the Action Family Rehab facility, located approximately 65 feet west of the project site. In cases where receptors may be closer than 82 feet (25 meters), any distance within the 82-foot (25- meter) buffer zone can be used. As such, the minimum distance of 25 meters was used for purposes of the LST assessment.
Based on the anticipated construction equipment that would be used onsite, it is assumed that the maximum daily disturbed acreage for the proposed project would be 3.5 acres. As such, a 3.5-acre threshold was derived for construction of the proposed project using interpolation. The maximum 5-acre threshold was applied for project operation. Table 4 lists the emissions thresholds that apply during project construction and operation.
Table 4. Localized Significance Thresholds for Source-Receptor Area 13 (Santa Clarita Valley) Emission Source
Pollutant Emissions Threshold (lbs/day)
NOx CO PM10 PM2.5
Construction 205.0 1,261.0 9.0 5.0
Operations 246.0 1,644.0 3.0 2.0
Source: SCAQMD (2008).
Notes: Source Receptor Area 13, based on a 3.5-acre construction disturbance daily area and 5-acre operational disturbance area, at a distance of 25 meters from the project boundary.
NO2 = nitrogen dioxide; CO = carbon monoxide; PM10 = coarse particulate matter; PM2.5 = fine particulate matter.
Environmental Evaluation
a) Would the project conflict with or obstruct implementation of the applicable air quality plan?
Less than Significant Impact. The project site is located within the SCAB, which includes the non-desert portions of Los Angeles, Riverside, and San Bernardino Counties and all of Orange County, and is within the jurisdictional boundaries of SCAQMD.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 20 SCAQMD administers SCAB’s Air Quality Management Plan (AQMP), which is a comprehensive document outlining an air pollution control program for attaining all CAAQS and NAAQS. The most recent adopted AQMP for the SCAB is the 2016 AQMP (SCAQMD 2017), which was adopted by SCAQMD’s Governing Board in March 2017. The 2016 AQMP focuses on available, proven, and cost- effective alternatives to traditional strategies while seeking to achieve multiple goals in partnership with other entities seeking to promote reductions in greenhouse gases (GHGs) and toxic risk, as well as efficiencies in energy use, transportation, and goods movement (SCAQMD 2017).
The purpose of a consistency finding with the AQMP is to determine if a project is consistent with the assumptions and objectives of the regional air quality plans, and if it would interfere with the region’s ability to comply with federal and state air quality standards. SCAQMD has established criteria for determining consistency with the currently applicable AQMP in Chapter 12, Sections 12.2 and 12.3 of the SCAQMD CEQA Air Quality Handbook (SCAQMD 1993). These criteria are:
• Whether the project would result in an increase in the frequency or severity of existing air quality violations, cause or contribute to new violations, or delay timely attainment of the ambient air quality standards or interim emission reductions in the AQMP. • Whether the project would exceed the assumptions in the AQMP or increments based on the year of project buildout and phase.
To address the first criterion, project-generated criteria air pollutant emissions have been estimated and analyzed for significance and are addressed below in the analysis for threshold b). Detailed results of this California Emissions Estimator Model (CalEEMod) 2022.1 Emissions Outputs used for this analysis are included in Appendix A. As presented in threshold b), construction and operation of the project would not generate criteria air pollutant emissions that exceed SCAQMD’s thresholds.
The second criterion regarding the project’s potential to exceed the assumptions in the AQMP or increments based on the year of project buildout and phase is primarily assessed by determining consistency between the project’s land use designations and its potential to generate population growth.
In general, projects are considered consistent with, and not in conflict with or obstructing implementation of, the AQMP if the growth in socioeconomic factors is consistent with the underlying regional plans used to develop the AQMP (per Consistency Criterion No. 2 of the SCAQMD CEQA Air Quality Handbook). SCAQMD primarily uses demographic growth forecasts for various socioeconomic categories (e.g., population, housing, employment by industry) developed by the Southern California Association of Governments (SCAG) for its Regional Transportation Plan/Sustainable Communities Strategy (RTP/SCS) (SCAG 2020a). This document, which is based on general plans for cities and counties in the SCAB, is used by SCAQMD to develop the AQMP emissions inventory (SCAQMD 2017). The SCAG 2020 RTP/SCS and the associated Regional Growth Forecast are generally consistent with the local plans; therefore, the 2016 AQMP is generally consistent with local government plans.
The project site is located within the City’s MXC zone, which allows the use of the property as proposed.
In addition, the implementation of the project would not generate an increase in growth demographics that would conflict with existing projections within the region. Accordingly, the project is consistent with the SCAG RTP/SCS forecasts used in the SCAQMD AQMP development.
In summary, based on the considerations presented for the two criteria, impacts relating to the project’s potential to conflict with or obstruct implementation of the applicable AQMP would be less than significant.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 21 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 SCAQMD develops and implements plans for future attainment of ambient air quality standards. Based on these considerations, project-level thresholds of significance for criteria pollutants are relevant in the determination of whether a project’s 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 VOC off-gassing) and off-site sources (i.e., on-road 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.
The CalEEMod Version 20 22.1 was used to estimate emissions from construction of the p roject.
Internal combustion engines used by construction equipment, trucks, and worker vehicles would result in emissions of VOCs, NO x, CO, PM10, and PM2.5. PM10 and PM2.5 emissions would also be generated by entrained dust, which results from the exposure of earth surfaces to wind from the direct disturbance and movement of soil. The p roject would be required to comply with SCAQMD Rule 403 to control dust emissions generat ed during any dust -generating activities. Standard construction practices that would be employed to reduce fugitive dust emissions include watering of the active dust areas two times per day, with additional watering depending on weather conditions. The Ca lEEMod default assumptions were used for estimating fugitive dust emissions from grading on-site. The project would involve application of architectural coating (e.g., paint and other finishes) for painting the interior and exterior of the building as well as parking lot striping . The contractor is required to procure architectural coatings from a supplier that complies with the requirements of SCAQMD’s Rule 1113 (Architectural Coatings).
Table 5 presents the estimated maximum daily construction emissions generated during construction of the project. Details of the emission calculations are provided in Appendix A .
Table 5. Estimated Maximum Daily Construction Criteria Air Pollutant Emissions Year
VOC NOx CO SOx PM10 PM2.5
(pounds per day)
Year 1 (analysis assumed 2025) 8.2 50.0 40.7 0.02 22.2 5.0 Year 2 (analysis assumed 2026) 42.3 23.1 34.4 <0.1 4.9 1.7 Maximum 42.3 50.0 40.7 0.02 22.2 5.0
SCAQMD Threshold 75 100 550 150 150 55
Threshold Exceeded? No No No No No No
Note: VOC = volatile organic compound; NOx = oxides of nitrogen; CO = carbon monoxide; SOx = sulfur oxides; PM10 = coarse particulate matter; PM2.5 = fine particulate matter.
As shown in Table 5, project construction would not exceed SCAQMD ’s daily thresholds.
The construction schedule that was used in the air quality analysis contained in Appendix A was based on construction beginning in January 2025 and closing June 2026. However, construction is anticipated Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 22 be phased and is expected to occur over several additional years. Because the air quality analysis assumed all phases of construction (grading, site preparation, building construction, paving, and architectural coating /painting) in a single year (i.e., 2026), it is a very conservative analysis . A longer construction duration, as anticipated for the project and described in Section 1.4, Project Description, would only decrease the air quality emissions anticipated for the project. Therefore, construction impacts associated with criteria air pollutant emissions would be less than significant.
Operational Emissions
Emissions from the operational phase of the project were estimated using CalEEMod. Operational year 2026 was assumed to be the first year following completion of construction. Table 6 presents the emissions during operation.
Table 6. Estimated Maximum Daily Operation Criteria Air Pollutant Emissions Emissions Source
VOC NOx CO SOx PM10 PM2.5
(pounds per day)
Area 15.8 0.0 23.3 <0.1 <0.01 <0.1
Energy 0.0 0.0 0.0 0.0 0.0 0.0
Mobile 9.7 8.9 95.9 0.2 22.0 5.7
Offroad 1.0 6.5 8.0 <0.1 0.2 0.2
Stationary 0.1 0.3 0.3 <0.1 <0.1 <0,1
Total 26.6 15.7 127.5 0.3 22.2 5.9
SCAQMD Threshold 55 55 550 150 150 55
Threshold Exceeded? No No No No No No
Note: VOC = volatile organic compound; NOx = oxides of nitrogen; CO = carbon monoxide; SOx = sulfur oxides; PM10 = coarse particulate matter; PM2.5 = fine particulate matter.
As shown in Table 6, the project would not exceed SCAQMD’s significance thresholds during operations. Therefore, operational impacts associated with criteria air pollutant emissions would be less than significant.
Cumulative Impacts
In considering cumulative impacts from the project, the analysis must specifically evaluate a project’s contribution to the cumulative increase in pollutants for which the SCAB is designated as nonattainment for the CAAQS and NAAQS. If a project’s emissions exceed SCAQMD’s significance thresholds, it would be considered to have a cumulatively considerable contribution to nonattainment status in the SCAB. If a project does not exceed thresholds and is determined to have less-than-significant, project- specific impacts, it may still contribute to a significant cumulative impact on air quality. The basis for analyzing the proposed project’s cumulatively considerable contribution is if the project’s contribution accounts for a considerable proportion of the cumulative total emissions (i.e., it represents a “cumulatively considerable contribution” to the cumulative air quality impact) and consistency with SCAQMD’s 2016 AQMP, which addresses cumulative emissions in the SCAB.
The SCAB has been designated as a federal nonattainment area for O 3 and PM2.5 and a state nonattainment
area for O3, PM10, and PM2.5. The nonattainment status is the result of cumulative emissions from various sources of air pollutants and their precursors within the SCAB, including motor vehicles, off-road equipment, and commercial and industrial facilities. Construction of the project would generate VOC and NOx emissions (which are precursors to O3) and emissions of PM10 and PM2.5. As indicated in Tables 5 Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 23 and 6, project-generated construction and operational emissions would not exceed SCAQMD’s emission- based significance thresholds for VOCs, NOx, CO, PM10, or PM2.5.
Cumulative localized impacts would potentially occur if a construction project were to occur concurrently with another off-site project. Construction schedules for potential future projects near the project site are currently unknown; therefore, potential construction impacts associated with two or more simultaneous projects would be speculative. However, future projects would be subject to CEQA and would require an air quality analysis and, where necessary, mitigation if the project would exceed SCAQMD’s significance thresholds. Criteria air pollutant emissions associated with construction activity of future projects would be reduced through implementation of control measures required by SCAQMD. Cumulative PM 10 and
PM2.5 emissions would be reduced because all future projects would be subject to SCAQMD Rule 403 (Fugitive Dust), which sets forth general and specific requirements for all construction sites in the SCAQMD.
Since criteria pollutant mass emissions impacts shown in Tables 5 and 6 would not be expected to exceed any of the air quality significance thresholds, cumulative air quality impacts would also be expected to be less than significant. SCAQMD cumulative air quality significance thresholds are the same as project- specific air quality significance thresholds. Therefore, potential adverse impacts from implementing the project would not be “cumulatively considerable” as defined by State CEQA Guidelines Section 15064(h)(1) for air quality impacts. Per State CEQA Guidelines Section 15064(h)(4), the mere existence of significant cumulative impacts caused by other projects alone shall not constitute substantial evidence that the project’s incremental effects are cumulatively considerable.
The SCAQMD’s guidance on addressing cumulative impacts for air quality is as follows: “As Lead Agency, the SCAQMD uses the same significance thresholds for project specific and cumulative impacts for all environmental topics analyzed in an Environmental Assessment or EIR. … Projects that exceed the project-specific significance thresholds are considered by the SCAQMD to be cumulatively considerable.
This is the reason project-specific and cumulative significance thresholds are the same. Conversely, projects that do not exceed the project-specific thresholds are generally not considered to be cumulatively significant” (SCAQMD 2003:D-3).
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 with Mitigation Incorporated. 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. According to SCAQMD, sensitive receptors include residences, schools, playgrounds, childcare centers, long-term healthcare facilities, rehabilitation centers, convalescent centers, and retirement homes (SCAQMD 1993). The nearest sensitive receptor land use is the Action Family Rehab facility, located approximately 65 feet northwest of the project site and existing single and multi-family residences located approximately 1,110 feet northeast of the project site’s northern boundary. Additional sensitive receptors include single and multi-family residences located in the Villa Metro Gated Community approximately 1,220 feet east of the project site’s eastern boundary.
The SCAQMD recommends the evaluation of localized air quality impacts to sensitive receptors such as residential land uses in the immediate vicinity of a project site as a result of construction activities.
The thresholds are based on standards established by the SCAQMD in its LST Methodology and are measured against emissions that occur on a specific project site. However, as described by the SCAQMD, the use of LSTs is voluntary and only applies to projects that must undergo an environmental analysis Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 24 pursuant to CEQA and are five acres or less. The SCAQMD recommends that proposed projects larger than five acres in area undergo air dispersion modeling to determine localized air quality (SCAQMD n.d.).
The project site is greater than 5 acres; however, a localized significance analysis was prepared for informational screening purposes. As stated by the SCAQMD, if the calculated emissions for the proposed construction or operational activities are below the LST emission levels found on the LST lookup tables, then the proposed construction or operation activity is not significant. Proposed projects whose calculated emission budgets for the proposed construction or operational activities are above the LST emission levels found in the LST lookup tables should not assume that the project would necessarily generate adverse impacts. Detailed emission calculations and/or air dispersion modeling may demonstrate that pollutant concentrations are below recommended thresholds (SCAQMD 2008). Project construction and operation emission were compared to the LST screening tables in SRA 13, based on a 25-meter source-receptor distance. The results of the LST analysis are summarized in Tables 7.
As shown in Tables 7, results of the LST analysis indicate that the proposed project would result in an exceedance of the SCAQMD LST for PM
10 during project construction but would not result in an exceedance of the SCAQMD LST during project operation. However, as stated by the SCAQMD, if the project exceeds any applicable LST when the mass rate look-up tables are used as a screening analysis, then project specific air quality modeling may be performed. As discussed above, proposed projects whose calculated emission budgets for the proposed construction or operational activities are above the LST emission levels found in the LST lookup tables should not assume that the project would necessarily generate adverse impacts. Detailed emission calculations and/or air dispersion modeling may demonstrate that pollutant concentrations are below localized significance levels. As such, a project-specific Health Risk Assessment (HRA) was prepared for the proposed project (LSA 2024b). The results of the HRA are summarized in Table 7, which presents conditions prior to mitigation.
Table 7. Localized Significance Thresholds Analysis for the Project (Prior to Application of MM AIR-1)
Pollutant Emissions
(pounds per day)
LST Criteria
(pounds per day) Exceeds LST?
Construction
NOxx 48.8 205.0 No
CO 35.3 1,261.0 No
PM10 16.5 9.0 Yes
PM2.5 3.1 5.0 No
Operation
NOx 7.3 246.0 No
CO 36.7 1,644.0 No
PM10 1.3 3.0 No
PM2.5 0.5 2.0 No
Source: LSA (2024a)
Notes: LST = localized significance threshold; NOx = nitrogen oxides; CO = carbon monoxide; PM10 = coarse particulate matter; PM2.5 = fine particulate matter.
See Appendix A for detailed results.
Source Receptor Area 13, based on a 3.5-acre construction disturbance daily area, at a distance of 25 meters from the project boundary. The emissions represent worst-case operating scenario during construction.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 25 As shown in the table, construction emissions for PM10 could exceed the applicable LST. As demonstrated in the HRA, with implementation of MM AIR-1, all health risk levels to nearby receptors from project-related emissions of TACs would be below the SCAQMD’s thresholds. However, with implementation of MM AIR-1, all health risk levels to nearby receptors from project-related emissions would be below the SCAQMD’s thresholds. As such, no significant health risk would occur from project- related emissions with implementation of MM AIR-1.
Carbon Monoxide Hotspots
Traffic-congested roadways and intersections have the potential to generate localized high levels of CO.
Localized areas where ambient concentrations exceed federal and/or state standards for CO are termed CO “hotspots.” CO transport is extremely limited and disperses rapidly with distance from the source.
Under certain extreme meteorological conditions, however, CO concentrations near a congested roadway or intersection may reach unhealthy levels affecting sensitive receptors. Typically, high CO concentrations are associated with severely congested intersections operating at an unacceptable level of service (LOS) (LOS E or worse is unacceptable). Projects contributing to adverse traffic impacts may result in the formation of a CO hotspot. Additional analysis of CO hotspot impacts would be conducted if a project would result in a significant impact or contribute to an adverse traffic impact at a signalized intersection that would potentially subject sensitive receptors to CO hotspots.
Title 40 of the Code of Federal Regulations (CFR) Section 93.123(c)(5), Procedures for Determining Localized CO, PM10, and PM2.5 Concentrations (Hot-Spot Analysis), states that “CO, PM10, and PM2.5 hot-spot analyses are not required to consider construction-related activities, which cause temporary increases in emissions. Each site which is affected by construction-related activities shall be considered separately, using established ‘Guideline’ methods. Temporary increases are defined as those which occur only during the construction phase and last five years or less at any individual site” (40 CFR 93.123).
While project construction would involve on-road vehicle trips from trucks and workers during construction, construction activities would last five years or less and would not require a project-level hotspot analysis
In addition, at the time that the SCAQMD Handbook (1993) was published, the SCAB was designated nonattainment under the CAAQS and NAAQS for CO. In 2007, the SCAQMD was designated in attainment for CO under both the CAAQS and NAAQS as a result of the steady decline in CO concentrations in the SCAB due to turnover of older vehicles, introduction of cleaner fuels, and implementation of control technology on industrial facilities. Based on CO modeling the SCAQMD conducted for the 2003 AQMP, CO concentrations at congested intersections would not exceed the 1-hour or 8-hour CO CAAQS unless projected daily traffic would be at least over 100,000 vehicles per day (SCAQMD 2003). Because the project is not anticipated to increase daily traffic volumes at any study intersection to more than 100,000 vehicles per day (Gibson Transportation Consulting, Inc. 2023), a CO hotspot is not anticipated to occur.
Toxic Air Contaminants
A toxic substance released into the air is considered a toxic air contaminant (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.
As previously noted, an HRA was prepared for the project (LSA 2024b; see Appendix A). As demonstrated in the HRA, with implementation of MM AIR-1 all health risk levels to nearby receptors from project-related emissions of TACs would be well below the SCAQMD’s HRA thresholds. As these results show, with implementation of MM AIR-1, all health risk levels to nearby receptors from project- Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 26 related emissions of TACs would be well below the SCAQMD’s HRA thresholds. As such, no significant health risk would occur from project-related emissions.
Conclusion
Based on the analysis of LSTs, CO hotspots, and toxic air contaminants, the project’s construction emissions for PM10 could exceed the applicable LST. However, with implementation of MM AIR-1, all health risk levels to nearby receptors from project-related emissions would be below the SCAQMD’s thresholds. In addition, no other significant health risk impacts would have the potential of occurring. Impacts related to the exposure of sensitive receptors to substantial pollutant concentrations would be less than significant with implementation of MM AIR-1.
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. The project could have a significant impact if it would create objectionable odors affecting a substantial number of people. The SCAQMD CEQA Air Quality Handbook (SCAQMD 1993) identifies certain land uses as sources of odors. Land uses and industrial operations associated with odor complaints include agricultural uses, wastewater treatment plants, food- processing plants, chemical plants, composting operations, refineries, landfills, dairies, and fiberglass molding facilities (SCAQMD 1993).
Construction activities associated with the project may generate detectable odors from heavy-duty equipment exhaust and architectural coatings. However, the nearest sensitive receptor land use is located approximately 650 feet west of the project site and construction-related odors would be short-term in nature and cease upon project completion.
The project would be required to comply with CCR Title 13, Sections 2449(d)(3) and 2485, which requires either shutting off construction equipment when not in use or reducing the idling time to no more than 5 minutes. This would reduce the detectable odors from heavy-duty equipment exhaust. The project would also be required to comply with the SCAQMD Rule 1113–Architectural Coating, which would minimize odor impacts from emissions of reactive organic gases during architectural coating. Any odor impacts to existing adjacent land uses would be short term and not substantial. Therefore, the project would not result in other emissions (such as those leading to odors) adversely affecting a substantial number of people. Impacts would be less than significant.
Conclusion
The project would include implementation of MM AIR-1 to address potentially significant air quality impacts. Upon implementation of this project-specific mitigation measure, impacts to air quality would be less than significant with mitigation incorporated.
Mitigation Measures
MM AIR-1 Diesel-powered Construction Equipment Requirements. During construction of the proposed project, the project contractor shall ensure all off-road diesel-powered construction equipment of 50 horsepower or more used for the project construction at a minimum meets the California Air Resources Board Tier 2 emissions standards equipped with level 3 diesel particulate filters. Verification shall be provided to the City of Santa Clarita Planning Division for confirmation, to the satisfaction of City staff.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 27 IV. Biological Resources
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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?
☐ ☐ ☐ ☒
This section is based on Appendix B: Biological Resources Reports. Refer to Appendix B for full details of existing conditions, applicable regulations, and methodologies. A brief summary is provided below.
Setting
This section is based, in part, on the following documents included in Appendix B:
• Biological Resources Technical Report: Riverview Project Prepared by Dudek, dated March 2024 (Dudek 2024a).
• Focused California Gnatcatcher Survey Results for the Riverview Development Project, City of Santa Clarita, California, prepared by Dudek, dated July 31, 2023 (Dudek 2023a).
Refer to Appendix B for full details of existing conditions, applicable regulations, and methodologies.
A brief summary is provided below. For this section, “biological study area” refers to the project site and a 500-foot buffer around the project site. Nine vegetation communities and four land cover types were identified within the biological study area during the survey: California Buckwheat Scrub (Eriogonum fasciculatum Shrubland), California Sagebrush Scrub (Artemisia californica Shrubland), Chamise Chaparral (Adenostoma fasciculatum Shrubland), Coast Live Oak Woodland and Forest (Quercus agrifolia Forest and Woodland), Fremont Cottonwood Forest and Woodland (Populus fremontii- Fraxinus velutina- Salix gooddingii Forest and Woodland Alliance), Scale Broom Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 28 (Lepidospartum squamatum) scrub, eucalyptus–tree of heaven–black locust groves (Eucalyptus spp.– Ailanthus altissima–Robinia pseudoacacia), pepper tree or Myoporum groves (Schinus (mole, terebinthifolius)–Myoporum laetum), Upland Mustards or Star-Thistle Fields (Brassica nigra–Centaurea (solstitialis, melitensis) Herbaceous Semi-Natural), disturbed habitat, parks and ornamental plantings, urban/developed, and non-vegetated channel. These vegetation communities and land cover types are described in the Biological Resources Technical Report (see Appendix B).
Eleven species of wildlife were observed during the survey. Some common bird species observed were American crow (Corvus brachyrhynchos), California scrub-jay (Aphelocoma californica), mourning dove (Zenaida macroura), lesser goldfinch (Spinus psaltria), northern mockingbird (Mimus polyglottos), European starling (Sturnus vulgaris), red-tailed hawk (Buteo jamaicensis), Anna’s hummingbird (Calypte anna), and house finch (Haemorhous mexicanus). No amphibian species were observed.
One reptile species was observed: western fence lizard (Sceloporus occidentalis). One mammal species, California ground squirrel (Otospermophilus beecheyi), was observed. Other common mammal species that could occur within the biological study area include coyote (Canis latrans), common raccoon (Procyon lotor), striped skunk (Mephitis mephitis), and Virginia opossum (Didelphis virginica), with the possibility of bats foraging over the biological study area.
Thirty special-status plant and 45 wildlife species have potential to occur in the area mapped on the USGS
7.5-minute Newhall quadrangle and the surrounding eight USGS 7.5-minute quadrangles, as well as wildlife species included within the U.S. Fish and Wildlife Service (USFWS) Information for Planning and Consultation (IPaC) list generated for the biological study area (California Department of Fish and Wildlife [CDFW] 2022; California Native Plant Society 2022; USFWS 2022). No special-status bird species were observed within the biological study area during the survey. Eleven species have a moderate or high potential to occur within the biological study area, with five of those species with potential to occur within the project site.
Environmental Evaluation
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 with Mitigation Incorporated. Construction of the project would have the potential to result in direct removal of special-status plant species if present within the project site.
In addition, construction activities have the potential to result in direct (e.g., take) or indirect (e.g., noise, dust, light pollution) disturbance to special-status wildlife species if present within the project site.
Potential impacts to special-status plant and wildlife species and the mitigation measures to reduce the impacts to less than significant are described below.
Direct Impacts
SPECIAL-STATUS PLANTS
One special-status plant species, slender mariposa lily (Calochortus clavatus var. gracilis), has a moderate potential to occur in the biological study area (Dudek 2024a). The species could be directly impacted during vegetation removal and grading; however, this portion of the project site is not expected to support a large population of the species due to the limited suitable habitat present (approximately 11 acres) and the density of the shrubs that compose those habitats limiting interspatial potential for the species to occur. As such, impacts to slender mariposa lily would be less than significant with the Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 29 implementation of Mitigation Measure (MM) BIO-1 (Pre-Construction Rare Plant Survey and Seed Collection).
SPECIAL-STATUS WILDLIFE
Four species have a moderate potential to occur (Southern California legless lizard [Anniella stebbinsi], California glossy snake [Arizona elegans], Blainville’s horned lizard [Phrynosoma blainvillii], and San Diego desert woodrat [Neotoma lepida intermedia]) and one species (coastal whiptail [Aspidoscelis tigris stejnegeri]) has a high potential to occur in the project site. One mammal species (San Diego desert woodrat) has a moderate potential to occur. These species are all designated as CDFW Species of Special Concern. Due to the presence of suitable habitat, and/or documented occurrences of these species within the vicinity of the project site, there is potential for these species to occur on site. If these species are determined to occur on the project site prior to construction, project-related impacts could be considered significant if the impact causes the greater population of either species to drop below self-sustaining levels. These species are vulnerable to mortality or injury during vegetation and ground-disturbing activities associated with construction in the native vegetation communities. It is highly unlikely that short-term construction activities could cause the greater population of these special-status species to drop below self-sustaining levels due to the relatively small area of construction activity and the short-term nature of the construction schedule. However, mortality or injury to species individuals is a reasonable possibility, so direct permanent impacts are possible and would be significant. Implementation of MM BIO-2 (Pre-construction Wildlife Survey) and MM BIO-3 (Biological Monitoring) would reduce impacts to less than significant.
Coastal California gnatcatcher (Polioptila californica californica) habitat exists in the vicinity of the project site, and focused surveys were conducted between April 12 and June 16, 2023. The coastal California gnatcatcher is a CDFW Species of Special Concern and is listed as threatened under the federal Endangered Species Act. As shown in the Focused California Gnatcatcher Survey Results (see Appendix B), no California gnatcatchers were observed or audibly detected during the surveys. Coastal California gnatcatcher is currently considered absent from the biological study area, and it is not expected to occur on the project site. Therefore, the potential for impacts to coastal California gnatcatcher would be less than significant.
On July 11, 2024, CDFW requested additional information regarding the Crotch’s bumble bee (Bombus crotchii), a candidate species under the California Endangered Species Act. A habitat assessment and survey were conducted on July 19, 2024 by Helix Environmental Planning. As well, two follow-on surveys were completed at least two weeks apart within the Crotch’s bumble bee colony active period (April to August). Crotch’s bumble bee surveys were conducted by slowly walking throughout suitable habitat within the project site, accounting for suitable Crotch’s bumble bee nesting locations, pollen and nectar sources, and foraging bumble bee activity. Focused surveys were completed on August 23, 2024.
Crotch’s bumble bee individuals or nests were not detected during the survey effort and are presumed to be absent from the project site. Multiple honey bee (Apis mellifera) hives were observed within the project site, which may outcompete bumble bees for nectar sources at the project site (Helix Environmental Planning 2024).
Indirect Impacts
SPECIAL-STATUS PLANTS
Any special-status plants in the areas adjacent to the project site could be inadvertently impacted should construction workers or vehicles stray out of the project footprint. Invasive plant species could be introduced during construction and landscape installation, that could alter the habitat for special-status Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 30 plants in the project vicinity. Invasive plants could compete with special-status plants for resources (i.e., water) and space. These indirect impacts could be potentially significant.
SPECIAL-STATUS WILDLIFE
Indirect short-term and long-term impacts to special-status wildlife species may include both habitat degradation and effects on individuals. Indirect construction impacts to wildlife habitat may include fugitive dust; runoff, sedimentation, chemical pollution, and erosion; litter; and accidental clearing, grading, and trampling, as well as attracting predators. Trash and other garbage associated with construction activities can degrade vegetation communities and wildlife habitat and can attract nuisance and pest species that affect several of the wildlife guilds. Trash and debris include discarded construction- related materials, such as packaging materials, which may be dispersed into natural areas by wind. Trash generated by construction personnel, such as food packaging and cigarette butts, also can be dispersed by wind and water into natural areas. Additionally, invasive plant species could be introduced during construction and landscape installation that could alter the habitat for special-status wildlife. These indirect impacts could be potentially significant.
Implementation of MM BIO-1 through MM BIO-5 would reduce potential indirect impacts to plants and wildlife species to less-than-significant levels.
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. Potential indirect impacts to the Santa Clara River and the riparian and sensitive communities it supports (Populus fremontii-Salix laevigata and Eriogonum fasciculatum- Lepidospartum squamatum alluvial fan) could result from construction activities. Erosion and chemical pollution (releases of fuel, oil, lubricants, paints, release agents, and other construction materials) produced during construction may affect wetlands and jurisdictional waters downstream of the project site due to sheet wash flowing through the project site and passing through the culvert under Soledad Canyon Road and into the Santa Clara River.
The project would be subject to Regional Water Quality Control Board (RWQCB) requirements and the City’s Municipal Code Chapter 17.90 for preparation and implementation of a Stormwater Pollution Prevention Plan (SWPPP),
1 which includes erosion control measures, such as covering exposed soil stockpiles, lining the perimeter of construction areas with sediment barriers, and protecting storm drain inlets. In addition, through MM BIO-5, the SWPPP shall be required to include site-specific best management practices (BMPs) that specifically address the sensitive location of the project site near and upstream from wetlands and jurisdiction waters. As stipulated by MM BIO-5, the project would be required to incorporate the following into the SWPPP: (1) the regular use of water trucks or other means of site irrigation to minimize fugitive dust during earthmoving and prevent fugitive dust from escaping the property boundary; (2) prohibition of vehicle fueling on-site; and (3) requirement that secondary containment be used for the temporary use all hazardous materials during construction activities and such containment shall be located as far as feasible from jurisdictional resources.
In addition, a silt fence barrier shall be required prior to the start of construction activities, as described in MM BIO-5. Implementation of the SWPPP and the additional required measures in MM BIO-5 would
1 The Biological Resources Technical Report dated March 2024 (see Appendix B), includes a mitigation measure for the preparation and implementation of a project-specific SWPPP. This is a regulation for all projects based on requirements set forth by the RWQCB and per regulation in the City’s Municipal Code Chapter 17.90 National Pollutant Discharge Elimination System (NPDES) Compliance. Therefore, it is not included as a separate mitigation measure in this document as it is already considered a requirement of the project.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 31 address construction-related debris and sedimentation and would prevent the project from degrading water quality in the Santa Clara River. Therefore, indirect impacts to riparian habitat and sensitive communities would be less than significant.
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. Jurisdictional wetlands and waters were not identified on the project site.
Therefore, there would be no direct impacts to jurisdictional wetlands and waters.
As mentioned above, implementation of the SWPPP and project design features, including water quality treatment basins that would improve water quality before it flows downstream to the stormwater drainage basins, would reduce potential indirect impacts to the Santa Clara River system. Therefore, indirect impacts related to federally protected wetlands would be 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 with Mitigation Incorporated. The project site does not function as a wildlife corridor or habitat linkage and is not within any designated wildlife corridors or habitat linkages.
The project would not limit or prohibit the use of the Santa Clara River wash for movement of fish and terrestrial wildlife species. Direct impacts to wildlife corridors and habitat connectivity are not anticipated; implementation of MM BIO-6 (Invasive Plant Species Prevention) would ensure that construction activities would not introduce nonnative species to the project site and impacts would therefore be less than significant. Lighting associated with the completed development could cause indirect impacts to wildlife movement in the Santa Clara River wash and adjacent open space areas that could be significant. The implementation of MM BIO-7 (Exterior Permanent Lighting) would reduce impacts to less than significant.
The project would be required to comply with the Migratory Bird Treaty Act (MBTA) and Sections 3503, 3503.5, and 3513 of the California Fish and Game Code by preventing the disturbance of nesting birds during construction activities. This would generally involve clearing a project site of all vegetation outside the nesting season (from September 1 through January 31) or, if construction would commence within the nesting season (which generally runs from February 1 through August 31 and as early as February 1 for raptors), conducting a pre-construction nesting bird survey to determine the presence of nesting birds or active nests at a construction site. Any active nests and nesting birds must be protected from disturbance by construction activities through buffers between nest sites and construction activities.
The buffer areas may be removed only after the birds have fledged. Compliance with the MBTA would ensure that the implementation of the project would not interfere with the nesting of any native bird species. Therefore, direct and indirect impacts would be less than significant due to compliance with regulations. The implementation of MM BIO-8 (Nesting Bird Avoidance) would reduce impacts to less than significant.
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. The City of Santa Clarita’s Oak Tree Ordinance (Ordinance 88-34) is the only local policy or ordinance that protects biological resources within the city. The analysis in Appendix B shows that of the 10 protected oak trees on the project site, nine are proposed for removal as part of this project, including one Heritage Oak. The remaining Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 32 protected oak tree would not be encroached upon as it is approximately 135 feet from proposed development. Direct impacts to trees protected under City’s Oak Tree Ordinance would be significant.
With the implementation of MM BIO-9 (Protected Tree Replacement), impacts to oak trees would be reduced to less-than-significant levels.
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. The biological study area is not within an area covered by any Habitat Conservation Plan, Natural Communities Conservation Plan, or other approved local, regional, or state habitat conservation plan (CDFW 2023). The biological study area is not within a County of Los Angeles–designated Significant Ecological Area (County of Los Angeles 2023). Therefore, there is no impact to a Habitat Conservation Plan, Natural Communities Conservation Plan, or other approved local, regional, or state habitat conservation plan.
Conclusion
The project would include implementation of MM BIO-1 through MM BIO-9. Upon implementation of these project-specific mitigation measures, impacts to biological resources would be less than significant with mitigation incorporated.
Mitigation Measures
MM BIO-1 Pre-Construction Rare Plant Survey and Seed CollectionConservation. Prior to issuance of a grading permit, the Applicant shall have a qualified biologist (the Applicant shall submit the qualifications of the biologist to the City for review and approval) conduct a focused rare plant survey for slender mariposa lily within the undeveloped portion of the project site during the appropriate blooming period (March through June).
The survey would consist of three passes, with one in April, May, and June. The survey shall consist of a maximum of three passes from March to June. Reference site checks would be made for the species to determine if the species is blooming in the project vicinity. If the reference site check is positive for the species, then the following survey shall determine the presence or absence of the species at the project site. The surveys would conform to the California Native Plant Society’s Botanical Survey Guidelines (2001); CDFW’s Protocols for Surveying and Evaluating Impacts to Special Status Native Plant Populations and Natural Communities (2018); and USFWS’ Guidelines for Conducting and Reporting Botanical Inventories for Federally Listed, Proposed and Candidate Plants (2000). The results of the surveys would be documented in a report and submitted to the City.
S
hould the species be found at a count of 20 or higher, then construction of the occupied location shall be delayed until the individuals have gone to seed. Seeds shall be collected once the seed has matured, but prior to the seed capsules opening to disperse the seed.
Seeds shall be stored in breathable paper bags in a cool, dry, and dark place. The seeds would then be donated to a City-approved local conservation organization (e.g., Friends of the Santa Clara River) to be used in restoration projects.
If the species is found at the project site, then construction of the occupied location shall be delayed, and one of the following measures shall be implemented:
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 33 Alternative No. 1: The project shall compensate for the loss of the species at a 1:1 ratio through the planting of replacement slender mariposa lily bulbs within the landscaped areas of the residential portion of the project, which will be maintained by the future homeowner’s association in perpetuity.
Alternative No. 2: If replacement slender mariposa lily bulbs cannot be reasonably located to implement the first alternative, the project shall compensate for the loss of discovered specimens by collecting the seeds of the onsite individuals. Seed collection and storage will be conducted by an entity with extensive experience performing those tasks (such as S&S Seeds or the California Botanical Garden) and approved by the City. The project Applicant will then work with City-approved local conservation organization (e.g., Friends of Santa Clara River) to be used in restoration projects. The Applicant shall provide the City with documentation of the seeds use.
MM BIO-2 Pre-construction Wildlife Survey. Prior to issuance of a grading permit, a qualified biologist (the Applicant shall submit the qualifications of the biologist to the City for review and approval) shall conduct a survey of the proposed impact areas and 50-foot buffer within 72 hours of the proposed activities. Any coastal whiptail, Southern California legless lizard, California glossy snake, or Blainville’s horned lizard found would be relocated to a City-approved off-site location in suitable habitat for each species. If a San Diego desert woodrat midden is discovered during the survey, then the biologist would methodically relocate the midden material to suitable habitat (dense shrubs) within 50 feet of its location and outside of the project disturbance limits.
The procedure would be implemented at a rate that would allow for the woodrat to flush from the midden. The results of the survey would be documented in a letter report to be submitted to the City.
MM BIO-3 Biological Monitoring. Prior to the issuance of a grading permit, the Applicant shall submit the qualifications of the biologist(s) to the City for review and approval. The Applicant shall fund a City-approved Biological Monitor during project construction to monitor construction activities and to ensure compliance with all mitigation measures.
The Biological Monitor shall be present on-site during all native vegetation removal and initial ground-disturbing activities in undeveloped areas. Each day, before project activities begin, the Biological Monitor shall be responsible for conducting a pre-construction clearance survey and any wildlife (common or special-status) would be relocated off-site to a City-approved area.
With regard to the Crotch’s bumble bee only, if construction activity would impact the
6.04 acres of potential foraging and nesting habitat (native vegetation communities) during the Crotch’s bumble bee nesting period (February 1 through October 31), the Biological Monitor shall conduct a pre-construction survey for Crotch’s bumble bee within the aforementioned 6.04 acres of natural vegetation area prior to the start of ground-disturbing construction activities within that 6.04 acres occurring during the Crotch’s bumble bee nesting period (February 1 through October 31). The survey shall ensure that no nests for Crotch’s bumble bee are located within that 6.04-acre area. The pre-construction survey shall be based on recommendations described in the “Survey Considerations for California Endangered Species Act Candidate Bumble Bee Species,” released by CDFW on June 6, 2023, or the most current at the time of construction.
The focused survey shall be performed by a Biological Monitor with a CDFW-issued Scientific Collection Permit (SCP) in surveying for bumble bees and include at least three Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 34 (3) survey passes that are not on sequential days or in the same week, preferably spaced two to four weeks apart. The timing of these surveys shall coincide with the Colony Active Period (April 1 through August 31 for Crotch’s bumble bee). Surveys may occur between 1 hour after sunrise and 2 hours before sunset. Surveys shall not be conducted during wet conditions (e.g., foggy, raining, or drizzling) and surveyors shall wait at least 1 hour following rain. Surveys may be conducted earlier than April 1 if other bees or butterflies are flying in the native vegetation communities on the project site. Surveys shall not be conducted when it is windy (i.e., sustained winds greater than 8 mph). Within non-developed habitats, the Biological Monitor shall look for nest resources suitable for bumble bee use. Ensuring that all nest resources receive 100 percent visual coverage, the biologist shall watch the nest resources for up to five minutes, looking for exiting or entering worker bumble bees. Worker bees should arrive and exit an active nest site with frequency, such that their presence would be apparent after five minutes of observation.
If a bumble bee worker is detected, then a representative shall be identified to species. If a nest is suspected, the Biological Monitor can block the entrance of the possible nest with a sterile vial or jar until nest activity is confirmed (no longer than 30 minutes).
Identification shall include the SCP-permitted Biological Monitor netting/capturing the representative bumble bee in appropriate insect nets, per the protocol in U.S. National Protocol Framework for the Inventory and Monitoring of Bees. The bee shall be placed in a clear container for observation and photographic documentation if able. The bee shall be photographed using a macro lens from various angles to ensure recordation of key identifying characteristics. If bumble bee identifying characteristics cannot be adequately captured in the container due to movement, the container shall be placed in a cooler with ice until the bumble bee becomes inactive (generally within 15 minutes). Once inert, the bumble bee shall be removed from the container and placed on a white sheet of paper or card for examination and photographic documentation. The bumble bee shall be released into the same area from which it was captured upon completion of identification. Based on implementation of this method on a variety of other bumble bee species, they become active shortly after removal from the cold environment, so photography must be performed quickly.
If Crotch’s bumble bee nests are not detected, no further mitigation would be required.
The mere presence of foraging Crotch’s bumble bees would not require implementation of additional minimization measures because they can forage up to 10 kilometers from their nests. If nest resources occupied by Crotch’s bumble bee are detected within the construction area, no construction activities shall occur within 100 feet of the nest, or as determined by the SCP-permitted Biological Monitor through evaluation of topographic features or distribution of floral resources. The nest resources shall be avoided for the duration of the Crotch’s bumble bee nesting period (February 1 through October 31).
Outside of the nesting season, it is assumed that no live individuals would be present within the nest as the daughter queens (gynes) usually leave by September, and all other individuals (original queen, workers, males) die.
A written survey report shall be submitted to the City within 30 days of the pre- construction survey. The report shall include survey methods, weather conditions, and survey results, including a list of insect species observed and a figure showing the locations of any Crotch’s bumble bee nest sites or individuals observed. The survey report shall include the qualification/resume of the SCP-permitted Biological Monitor for identification of photo vouchers, detailed habitat assessment, and photo vouchers. If Crotch’s bumble bee nests are observed, the survey report shall also include recommendations for avoidance, and the location information shall be submitted to the Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 35 California Natural Diversity Database (CNDDB) at the time of, or prior to, submittal of the survey report.
MM BIO-4 Demarcation of Disturbance Limits. Prior to commencement of earthwork in the undeveloped portion of the project site, the construction limits shall be clearly demarcated (e.g., installation of flagging or temporary high-visibility construction fence), as recommended by the Biological Monitor. All construction activities including equipment staging and maintenance shall be conducted within the marked disturbance limits to prevent inadvertent disturbance to sensitive vegetation communities outside the limits of work. The flagging shall be maintained throughout construction.
MM BIO-5 Stormwater Pollution Prevention Plan. Prior to issuance of a grading permits for construction activity that would require more than one acre of earthwork, the project developer shall develop a Stormwater Pollution Prevention Plan (SWPPP) that provides for require erosion and sediment control Best Management Practices (BMPs) to be implemented during construction activities. The SWPPP shall be submitted to the City for review and approval prior to the issuance of a grading permit. For construction activities on individual lots that are less than one acre in size, a site-specific listing of BMPs shall be prepared using appropriate and feasible measures included in the primary SWPPP document and shall be submitted to the City for review and approval prior to the issuance of a grading permit. The site-specific SWPPP shall include measures including, but not be limited to: (1) the regular use of water trucks or other means of site irrigation to minimize fugitive dust during earthmoving and prevent fugitive dust from escaping the property boundary; (2) prohibition of vehicle fueling on-site; and (3) requirement that secondary containment be used for the temporary use all hazardous materials during construction activities and such containment shall be located as far as feasible from jurisdictional resources. Subsequent to approval by the City, the requirements of the SWPPP shall be implemented prior to and during construction activities, as specifically required in the SWPPP.
At the culvert in the northwest portion of the project site, a silt fence barrier shall be constructed around it prior to the start of construction activities. Wooden posts supporting the silt fence shall be spaced 2 to 3 feet apart and driven securely into the ground; a minimum of 18 to 20 inches deep. The bottom edge of the silt fence is required to extend across the bottom of the trench and the trench shall be backfilled and compacted to prevent stormwater and sediment from discharging underneath the silt fence. Silt fences shall be inspected weekly and immediately after storm events to ensure they are intact and that there are no gaps where the fence meets the ground or tears along the length of the fence. If gaps or tears are found during the inspection, the fabric is required to be repaired or replaced immediately.
MM BIO-6 Invasive Plant Species Prevention. The project shall not include invasive plant species listed on the California Invasive Plant Council inventory in project landscaping palettes.
Project landscape palettes shall be reviewed and approved by the City to ensure that invasive plant species are excluded. In addition, to prevent the spread of invasive plant species during construction and until the establishment of common landscaped areas associated with the project (for a period of up to 5 years):
• All equipment shall be washed prior to entering and prior to leaving the project site in an upland location where any seed material from invasive species would be contained.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 36 • All vegetative material removed from the project impact footprint shall be transported in a covered vehicle and would be disposed of at a certified disposal site.
MM BIO-7 Exterior Permanent Lighting. To address indirect impacts to special-status wildlife due to lighting, exterior lighting associated with final project development shall be designed to be minimal (only as needed for security and safety) to lessen the attraction of birds, bats, and other sensitive wildlife species.
MM BIO-8 Nesting Bird Avoidance. Project construction shall be conducted in compliance with the conditions set forth in the MBTA and California Fish and Game Code to protect active bird/raptor nests. To the maximum extent feasible, vegetation removal shall occur during the non-breeding season for nesting birds (generally late September to early March) and nesting raptors (generally early July to late January) to avoid impacts to nesting birds and raptors. If the project requires that work be initiated during the breeding season for nesting birds (March 1–September 30) and nesting raptors (February 1–June 30), in order to avoid direct impacts on active nests, a pre-construction survey shall be conducted for the project site and a 500-foot buffer around the project site by qualified biologists (someone who has more than 3 years of experience of conducting nesting bird surveys in the project region) for nesting birds and/or raptors within 3 days prior to project activities. If the biologist does not find any active nests within or immediately adjacent to the impact areas, the vegetation clearing/construction work shall be allowed to proceed.
If the biologist finds an active nest within or immediately adjacent to the construction area and determines that the nest may be impacted or breeding activities substantially disrupted, the biologist shall delineate an appropriate buffer zone around the nest depending on the sensitivity of the species and the nature of the construction activity.
To protect any nest site, the following restrictions to construction activities shall be required until nests are no longer active, as determined by a qualified biologist (someone who has more than 3 years of experience of conducting nesting bird surveys and monitoring active nests during construction): 1) clearing limits shall be established within a buffer around any occupied nest; and 2) access and surveying shall be restricted within the buffer of any occupied nest, unless otherwise determined by a qualified biologist (someone who has more than 3 years of experience of conducting nesting bird surveys and monitoring active nests during construction). The buffer shall be up to 300 feet for non-raptor nesting birds and up to 500 feet for nesting raptors, based upon the biologist’s determination of potential effect of project activities on the nest.
Construction can proceed into the buffer when the qualified biologist has determined that the nest is no longer active.
MM BIO-9 Protected Tree Replacement. The Applicant would comply with the City of Santa Clarita Oak Tree Ordinance and would obtain an oak tree permit prior to the issuance of the grading permit for the project. Conditions of the oak tree permit may include the payment of a fee, planting of replacement trees on the project site, or donation of boxed trees to the City or other approved public agency to be used elsewhere in the city.
The nine trees to be removed shall be replaced by a tree of the same species at a ratio determined by the Urban Forestry Division of the City of Santa Clarita, with a minimum of 55 replacement trees required. All replacement trees shall be at least a 24‐gallon specimen in size and measure 2 inches or more in diameter, as measured from approximately 4 feet above the base. Replacement trees shall be certified as being grown from a seed source collected in Los Angeles County.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 37 For replacement trees planted on the project site, the Applicant shall be responsible for submitting quarterly tree inspection reports to the City prepared by a certified oak tree expert that shall be required to document the condition of the trees. The inspection and reporting would be required for 2 years following the planting of the replacement trees.
Any tree that fails during the 2-year period would be replaced by a 24‐gallon specimen of the same species and then monitored for an additional 2 years.
V. Cultural Resources
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
Would the project:
(a) Cause a substantial adverse change in the significance of a historical resource pursuant to State CEQA
Guidelines Section 15064.5?
☐ ☐ ☐ ☒
(b) Cause a substantial adverse change in the significance of an archaeological resource pursuant to State CEQA
Guidelines Section 15064.5?
☐ ☒ ☐ ☐
(c) Disturb any human remains, including those interred outside of dedicated cemeteries?
☐ ☐ ☒ ☐
The analysis for this section is based on the Archaeological Resources Technical Report: Riverview Development Project, Santa Clarita Valley, provided as Appendix C: Archaeological Resources Technical Report (Dudek 2024b), and the Built Environment Inventory and Evaluation Report: Riverview Development Project, Santa Clarita Valley (Dudek 2024c), provided as Appendix D: Built Environment Report). Refer to Appendix C and Appendix D for a detailed discussion of the historic setting for the region and project site as well as the applicable regulations pertaining to cultural resources.
In support of the archaeological resources assessment prepared for the project (see Appendix C), an archaeological literature and records search was conducted through the California Historical Resources Information System (CHRIS); background research included a literature, archival document, historical map, and aerial photograph review; and an intensive pedestrian field survey was conducted. The CHRIS records search was completed at the South Central Coast Information Center (SCCIC), California State University, Fullerton, for the project site and a 1-mile radius and included a review of the National Register of Historic Places (NRHP), the California Register of Historical Resources (CRHR), the California Points of Historical Interest list, the California Historical Landmarks list, the Archaeological Determinations of Eligibility list, and the California State Historic Resources Inventory list. The geotechnical investigation prepared for the project site was also reviewed (see Appendix C).
Built environment features, dating between 1926 and post-1978, are located on the project site. As a result, a built environment assessment was completed. The built environment assessment for the project
included a review of the CHRIS search results obtained during the archaeological resources assessment, an intensive pedestrian field survey conducted by qualified architectural historians, online archival research, historical society outreach, the development of a historic context statement, preparation of a property-specific history of the project site, and a formal evaluation under the City’s local criteria for designating historic resources, along with the criteria used to list resources in the CRHR and the NRHP (see Appendix C).
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 38 Setting
As detailed in the archaeological and built environment assessments, the CHRIS records search determined that no cultural resources have been previously identified within the project site (Dudek 2024b, 2024c). Within 1 mile of the project site, 16 cultural resources have been previously identified: five prehistoric archaeological sites (the closest of which is 984 feet [0.2 mile]), six prehistoric isolates (the closest of which is 469 feet [0.1 mile]), and five built environment resources (the closest of which is 1,804 feet [0.3 mile]). In addition, 53 cultural resource investigations have been undertaken within 1 mile of the project site, one of which addressed a portion of the project site. The results of these investigations can be found in Appendices C and D.
The geotechnical investigation consisted of 10 boring locations within the central, northeastern, and southeastern portions of the project site (see Appendix C). Artificial fill soils were identified in two boring locations in the southeastern quadrant of the project site, extending between grade and 6 feet below grade. No artificial fill was observed in the remaining eight bore locations. Alluvial soil was identified between grade and 35 to 60 feet below current grade across the project site.
The field survey for the archaeological assessment was conducted on October 18, 2022, and the field survey for the built environment assessment was conducted on January 25, 2023. The majority of the property is developed with pavement and structures. There are extensive parking areas, both paved and covered in manufactured gravel fill, resulting in highly variable ground surface visibility ranging from no visibility (0%) to fair visibility (30%) in these areas. The remaining portion of the project site included undeveloped rugged hills with sparse to dense vegetation. The ground surface visibility within this area was very good to excellent (60%–90%). No archaeological resources were identified as part of the archaeological assessment (Dudek 2024b).
The project site is located on what was historically known as the Banker Ranch Rodeo/Bonelli Stadium.
The built environment field survey identified 19 permanent buildings and structures dating from between 1926 and post-1978. The evaluation of the project site concluded that the property is not eligible for listing under the City’s local criteria for designating historic resources, nor is it eligible for the NRHP or the CRHR due to lack of sufficient integrity (Dudek 2024c).
Environmental Evaluation
a) Would the project cause a substantial adverse change in the significance of a historical resource pursuant to State CEQA Guidelines Section 15064.5? No Impact. As stated in State CEQA Guidelines Section 15064.5(b)(1), a project causing a substantial adverse change in the significance of a historical resource is one that could result in the physical demolition, destruction, relocation, or alteration of the resource or its immediate surroundings, such that the significance of a historical resource would be materially impaired (i.e., altering those physical characteristics that convey its historical significance and that justify its inclusion in, or eligibility for inclusion in, the CRHR as determined by a Lead Agency [the City of Santa Clarita] for purposes of CEQA, or its inclusion in a local register of historical resources pursuant to Section 5020.1(k) of the PRC).
The built environment assessment identified 19 permanent buildings and structures dated between 1926 and post-1978. The evaluation of the project site concluded that the property is not eligible for listing under the City’s local criteria for designating historic resources, nor is it eligible for the NRHP or the CRHR due to its lack of sufficient integrity. As such, the structures are not considered to be historical resources for the purposes of CEQA (Dudek 2024c). Therefore, no historic resources would be Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 39 demolished, relocated, removed, or significantly altered with project implementation. No impact would occur.
b) Would the project cause a substantial adverse change in the significance of an archaeological resource pursuant to State CEQA Guidelines Section 15064.5? Less than Significant with Mitigation Incorporated. Ground disturbance associated with the project includes significant grading and terracing of the hillside in the northwestern portion of the proposed project site and cut slopes at a gradient of 2:1 in the southern area. Significant fill grading within the area currently occupied by structures and paved tracks and parking lots would occur. This latter area is proposed for construction of residential and commercial development including 318 single-family dwelling units and a 126,790square foot manufacturing building, recreational amenities, community open space, paved lots, and associated utility and landscaping installation. Additionally, ground disturbance would be required for off-site improvements. Given that the entire proposed project site elevation is currently between 1,190 and 1,290 amsl and the elevation after grading is proposed between approximately 1,196 and 1,209 amsl, the proposed grading and construction would require impacts to native soils within the northern portion of the site and along the southwestern boundary; however, much of the proposed construction within the central and eastern portions of the site would occur within fill soils only.
No archaeological resources were identified through the records search or field survey (Dudek 2023b).
However, due to the overall sensitive nature of the general area surrounding the project site, it is possible that previously unrecorded cultural material and features could be encountered during project implementation. Any impacts to archaeological resources would be potentially significant.
Implementation of MM CR-1 through MM CR-3—including archaeological monitoring after the preparation of a Cultural Resource Monitoring and Inadvertent Discovery Plan, the development of a Worker Environmental Awareness Program (WEAP) training, and an inadvertent discovery clause would ensure impacts of the project would be less than significant with mitigation incorporated. c) Would the project disturb any human remains, including those interred outside of dedicated cemeteries?
Less than Significant Impact. There are no known human remains in the project site (Dudek 2023b).
While the discovery of human remains is always a possibility in undisturbed soils, there is no evidence to suggest that there is more than a low potential for discovery. Section 7050.5 of the State of California Health and Safety Code states that in the event that human remains are discovered or suspected, the County Coroner must be contacted immediately, and that no further disturbance shall occur until the County Coroner has determined the origin and requisite disposition of the remains pursuant to PRC 5097.98. If the human remains are determined to be Native American in origin, the Coroner would notify the Native American Heritage Commission (NAHC), which would determine and notify the most likely descendent. Native American human remains would be treated in accordance with PRC 5097.98. These existing laws and regulations would ensure that in the event of unanticipated discovery, impacts to human remains would be less than significant.
Conclusion
The project would include implementation of MM CR-1 through MM CR-3. Upon implementation of these project-specific mitigation measures, impacts to cultural resources would be less than significant with mitigation incorporated.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 40 Mitigation Measures
MM CR-1 Archaeological Monitoring. Prior to ground-disturbing activities, the Applicant and/or subsequent responsible parties should retain a Principal Investigator/Archaeologist, meeting the Secretary of the Interior’s Standards, and with experience in California prehistoric and historic resources (experience within Los Angeles County preferred), to complete the following: compose a Cultural Resource Monitoring and Inadvertent Discovery Plan (Plan), manage archaeological monitoring, and address any inadvertent discoveries identified during project implementation. The Plan shall cover both development of the 35.2-acre project site as well as any necessary off-site improvements (e.g., transportation and infrastructure improvements) associated with the project. Proof of retainment of the Principal Investigator/Archaeologist should be provided to the City prior to the granting of a grading permit. The purpose of the Plan is to outline archaeological monitoring protocols and a program of treatment and mitigation in the case of an inadvertent discovery of archaeological resources during ground-disturbing phases and to provide for the proper identification, evaluation, treatment, and protection of any archaeological resources in accordance with CEQA throughout the duration of the project. Existence and importance of adherence to this Plan should be stated on all project site plans intended for use by those conducting the ground-disturbing activities.
The Principal Investigator/Archaeologist should manage archaeological monitoring conducted by archaeological technicians during initial ground disturbances. Initial excavation is defined as initial construction-related earth moving 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. The retained Principal Investigator/Archaeologist should oversee and establish monitoring efforts as needed (increase, decrease, or discontinue monitoring frequency) based on the observed potential for construction activities to encounter archaeological deposits or material. The archaeological monitor should be responsible for maintaining daily monitoring logs. The requirement for archaeological monitoring should be noted on all construction plans to ensure implementation. Upon completion of all ground-disturbing activities, an archaeological monitoring report should be prepared within 60 days following completion of ground disturbance and submitted to the City for review. This report should document compliance with approved cultural resource mitigation, all monitoring efforts, and include an appendix with daily monitoring logs.
The final report should be submitted to the City and the SCCIC.
MM CR-2 Worker Environmental Awareness Program (WEAP) Training. All construction personnel and monitors who are not trained archaeologists should be briefed regarding unanticipated discoveries prior to the start of ground-disturbing activities. A basic presentation should be prepared and presented by a qualified archaeologist to inform all personnel working on the project about the archaeological sensitivity of the area. The purpose of the WEAP training is to provide specific details on the kinds of archaeological materials 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 should also be instructed on the proper procedures to follow in the event that archaeological resources or human remains are uncovered during ground-disturbing activities. These procedures include work curtailment or redirection, and the immediate contact of the on-call archaeologist and if appropriate, tribal representative. Necessity of training attendance should be stated on all project site plans intended for use by those conducting the ground-disturbing activities.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 41 MM CR-3 Inadvertent Discovery Clause. In the event that potential prehistoric or historic-era archaeological resources (sites, features, or artifacts) are exposed during construction activities for the project, all construction work occurring within 50 feet of the find shall immediately stop and the Principal Investigator/Archaeologist notified immediately in order 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 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 shall be required. If archaeological resources are discovered or are suspected to be of Native American origin, each of the consulting tribes for the project should also be notified.
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, PRC Section 5097.98, and State 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 area (within 100 feet of the find) 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 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 should then complete their inspection and determine, in consultation with the property owner, the treatment and disposition of the human remains.
VI. Energy
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
Would the project:
(a) Result in a 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?
☐ ☐ ☒ ☐
Setting
Energy sources include energy in the form of electricity, natural gas, and petroleum-based transportation- related energy (gasoline and diesel). The project receives electricity from SCE and natural gas from SoCalGas. Transportation fuels are produced from crude oil, which can be domestically imported from various regions around the world.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 42 As stated in the project’s Air Quality, Energy, and Greenhouse Gas Technical Memorandum (LSA 2024a; see Appendix A), CalEEMod default values for energy consumption by land use were applied for the project analysis.
Environmental Evaluation
a) Would the project result in a potentially significant environmental impact due to wasteful, inefficient, or unnecessary consumption of energy resources, during project construction or operation?
Less than Significant Impact. Construction and operation of the project would require the consumption of energy resources in several forms at the project site and within the project vicinity. The project would consume energy in the form of electricity, natural gas, and petroleum-based transportation-related energy (gasoline and diesel).
Construction
The project’s construction process would consume electricity and fuel. Project-related construction activities would represent a “single-event” demand and would not require ongoing or permanent commitment of energy resources. The amount of energy and fuel use anticipated by project construction activities are typical for the type of scale of construction proposed and there are no aspects of the project’s proposed construction process that are unusual or energy intensive. Furthermore, construction equipment would be required to conform to the applicable California Air Resources Board (CARB) emissions standards, acting to promote equipment fuel efficiencies.
Temporary electric power for as-necessary lighting and electronic equipment, such as computers inside temporary construction trailers, would be provided by SCE. The electricity used for such activities would be temporary, would be substantially less than that required for project operation, and would therefore have a negligible contribution to the project’s overall energy consumption.
Construction activities typically do not involve the consumption of natural gas. Therefore, construction of the project would not consume natural gas in a wasteful, inefficient, or unnecessary manner.
Construction of the project would comply with state and federal regulations, such as the anti-idling regulation in accordance with Title 13 CCR Section 2485, and fuel requirements in accordance with Title 17 CCR Section 93116, which would reduce the consumption of petroleum-based transportation fuels from unnecessary idling fuel combustion. While these required regulations are intended to reduce construction emissions, compliance with anti-idling and emissions regulations would also result in reductions in fuel consumption. Project-related trips from on-road vehicles (i.e., delivery trucks, worker vehicles) would also benefit from the State’s Low Carbon Fuel Standards which are designed to reduce vehicle GHG emissions, resulting in fuel consumption reductions, in addition to compliance with the federal Corporate Average Fuel Economy standards. Therefore, construction of the project would not consume petroleum-based fuel in a wasteful, inefficient, or unnecessary manner. Impacts during project construction would be less than significant.
Operation
The operational phase would require electricity for multiple purposes, including building heating and cooling, lighting, and electronics. CalEEMod was used to estimate project emissions from electricity uses (see Appendix A). Default electricity generation rates in CalEEMod were used based on the proposed land use and climate zone.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 43 The project provides conventional manufacturing building use reflecting contemporary energy efficient/energy conserving designs and operational programs. The use proposed by the project is not inherently energy intensive, and the project energy demands in total would be comparable to, or less than, other mixed-use housing projects of similar scale and configuration. Furthermore, the project would be required to comply with Title 24 standards, which would ensure that the project’s energy demand would not be considered inefficient, wasteful, or otherwise unnecessary. Impacts during project operation would be less than significant and no mitigation measures are necessary. b) Would the project conflict with or obstruct a state or local plan for renewable energy or energy efficiency?
Less than Significant Impact. The proposed project would be subject to state regulations for energy efficiency, namely, California’s Building Energy Efficiency Standards and California Green Building Standards Code (CALGreen), both of which are set forth in the CCR, Title 24. California’s Building Energy Efficiency Standards were established in 1978, and serve to enhance and regulate California’s building standards. These standards include regulations for residential and nonresidential buildings constructed in California to reduce energy demand and consumption. The Building Energy Efficiency Standards are updated periodically (every 3 years) to incorporate and consider new energy-efficiency technologies and methodologies. CALGreen institutes mandatory minimum environmental performance standards for all ground-up, new construction of commercial, low-rise residential, and State-owned buildings, as well as schools and hospitals. The 2022 CALGreen standards became effective on January 1, 2022. The proposed project would meet Building Energy Efficiency Standards and CALGreen standards to reduce energy demand and increase energy efficiency.
The proposed project would follow applicable energy standards and regulations during construction and operations. In addition, the proposed project would be built and operated in accordance with all existing, applicable regulations at the time of construction. As such, the proposed project would not conflict with existing energy standards and regulations. Impacts would be less than significant, and no mitigation measures are necessary.
Conclusion
The project would not result in a significant adverse impact to energy; no mitigation measures are necessary.
VII. Geology and Soils
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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? ☐ ☒ ☐ ☐
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 44 Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
(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 wastewater disposal systems where sewers are not available for the disposal of
wastewater?
☐ ☐ ☐ ☒
(f) Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature?
☐ ☒ ☐ ☐
Environmental Evaluation
a) Would the project directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury, or death involving:
a-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 with Mitigation Incorporated. Southern California is a seismically active region with over 100 active faults in Los Angeles County alone. Active faults are those faults that are considered likely to undergo renewed movement within a period of concern to humans. These include faults that are currently slipping, those that display earthquake activity, and those that have historical surface rupture.
The Alquist-Priolo Earthquake Fault Zone Act (Alquist-Priolo Act) is a California state law that was developed to regulate development near active faults and mitigate the surface fault rupture potential and other hazards. The Alquist-Priolo Act identifies active earthquake fault zones and restricts the construction of habitable structures over known active or potentially active faults, requiring that habitable structures do not encroach on a 50-foot setback from the fault trace. The California Geological Survey designates the fault zones extending approximately 200 to 500 feet from known active faults as Alquist- Priolo Earthquake Fault Zones (CDOC 2023).
According to GeoSoils (2022), the project site is located within an Alquist-Priolo Earthquake Fault Zone, and the San Gabriel Fault is located at the western part of the site. Until disproven, an area within 50 feet of an active fault is presumed to be underlain by active branches of the fault. Although there is no evidence of displacement along the San Gabriel Fault, there are faults near the site that have evidence of displacement (Allan E. Seward Engineering Geology, Inc. 2007); therefore, a structural setback of 75 feet has been recommended as part of the design. With implementation of MM GEO-1 (Structural Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 45 Engineering and Setback Requirements), impacts related to earthquake fault rupture would be less than significant.
a-ii) Strong seismic ground shaking?
Less than Significant Impact with Mitigation Incorporated. Southern California is a seismically active region with over 100 active faults in Los Angeles County alone. Active faults are those faults that are considered likely to undergo renewed movement within a period of concern to humans. These include faults that are currently slipping, those that display earthquake activity, and those that have historical surface rupture.
Since Santa Clarita is in a seismically active region, the project site will likely be subject to strong seismic ground shaking at some point in the future. However, the risks of structural damage from an earthquake can be minimized through proper engineering design. The project would be designed and constructed in conformance with seismic design criteria (e.g., requirements for lateral force resisting system, building foundations, footings, etc.) set forth in Section 16.13 of the California Building Code (CBC) and City- adopted seismic design related measures set forth in the City’s Municipal Code. In addition, the project would be subject to project-specific geotechnical plan review. Further, all construction work is subject to building inspection by the City Department of Building and Safety during and after construction to ensure that code specifications are properly constructed.
GeoSoils (2022) has recommended a structural setback to be included as part of the design. In addition to the San Gabriel Fault, there are faults near the site that can cause moderate to intense ground shaking during the lifetime of the proposed development. Therefore, implementing earthquake-resistant design for the structures to resist strong seismic ground shaking is recommended. However, this hazard can be mitigated by implementing MM GEO-1, which consists of structural mitigation to withstand the anticipated ground shaking and static and seismic-induced settlement. With implementation of MM GEO-1 and conformance to standard engineering practices, design criteria set forth in the City’s Municipal Code, and recommendations of the project-specific geotechnical plan review would reduce the effects of seismic ground shaking. With implementation of MM GEO-1, impacts related to strong seismic ground shaking would be less than significant.
a-iii) Seismic-related ground failure, including liquefaction? Less than Significant Impact with Mitigation Incorporated. Soil liquefaction occurs when soil material loses strength in response to strong ground shaking. Liquefaction normally occurs under saturated conditions in soils, such as sand; however, liquefaction is not exclusively limited to sandy substrate.
In accordance with the State of California Seismic Hazard Zones Map (CDOC 2023), the site is within a potential liquefaction zone. The project-specific geotechnical study (GeoSoils 2022) evaluated the potential for liquefaction within the project site and indicates that there is a potential for liquefaction- induced seismic settlement in the area of study. Analyses indicate that the potentially liquefiable zone is at approximately 10 to 50 feet below the ground surface. Additional liquefaction settlement could occur due to structural loads. On the west side of the proposed development, where bedrock is at 60 feet deep, the bedrock formation will get shallower before reaching the ground surface on the property line.
Consequently, the seismic settlement may be zero on the western property line versus almost 150 to 200 feet away from it toward the east.
Therefore, seismic-related ground failure, including liquefaction, may occur unless mitigated within the design of the project. With implementation of MM GEO-1, impacts related to seismic-related ground failure, including liquefaction, would be less than significant.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 46 a-iv) Landslides?
No Impact. Landslides occur when the underlying geological support on a hillside can no longer maintain the load of material above it, causing a slope failure. Geologic mapping by Dibblee and Ehrenspeck (1996) indicate the presence of landslide deposits on the slopes on the northside of Soledad Canyon; however, geologic mapping by Campbell and others (2014) do not indicate the presence of landslide deposits within the bounds of the project site or within its adjacent hills. Additionally, GeoSoils (2022) did not indicate the presence of landslide deposits during the geotechnical investigation, but recommended the hillside located at the western part of the site be graded. Therefore, there is no impact potential for landslides within the project site.
b) Result in substantial soil erosion or the loss of topsoil? Less than Significant Impact. According to U.S. Department of Agriculture NRCS soil survey data, the project site contains a sandy loam with a slope of 2 to 9 percent. The site is considered well drained with a low runoff class (NRCS 2023). Classified as Hydrologic Soils Group A, the topsoil has very little silt or clay and has deep, permeable loess with a high infiltration rate (NRCS 2023). Grading and excavation activities could expose soils that could be susceptible to erosion. However, the project would be subject to RWQCB requirements for preparation of a SWPPP, which include erosion control measures, such as covering exposed soil stockpiles, lining the perimeter of construction areas with sediment barriers, and protecting storm drain inlets. These measures would control and reduce erosion and loss of topsoil to the maximum extent practical. Once construction is complete, exposed soils would be paved over or landscaped and operational impacts related to soil erosion or loss of topsoil would not occur. Therefore, impacts related to substantial soil erosion or loss of topsoil 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 with Mitigation Incorporated. Landslides occur when the underlying geological support on a hillside can no longer maintain the load of material above it, causing a slope failure. According to the project-specific geotechnical study conducted by GeoSoils (2022), the hillside located at the western part of the site would be removed during grading. Geologic structure is favorable relative to the slopes along the southern part of the site and the site is flat and not subject to landslides.
No landslides were previously mapped within the site boundaries and no landslides were observed on the site during the exploration. Therefore, no impact due to landslides (on- or off-site) would occur.
Lateral spreading is a phenomenon in which large blocks of intact, non-liquefied soil move downslope on a liquefied soil layer. Lateral spreading is often a regional event. For lateral spreading to occur, a liquefiable soil zone must be laterally continuous and unconstrained to move along sloping ground. The site is relatively flat; therefore, there is a very low potential for lateral spreading. Therefore, impacts related to lateral spreading would be less than significant.
Land subsidence is a gradual settling or sudden sinking of the earth’s surface owing to subsurface movement of earth materials; it is not the result of a landslide or slope failure. According to the USGS map of areas of land subsidence in California (USGS 2023), the project site is not located within a mapped area of subsidence. However, seismic shaking accompanying any earthquake may induce settlement of loose unconsolidated soils. Based on site subsurface conditions and the moderate to high seismicity of the region, any loose fill materials at the site could be vulnerable to this potential hazard, resulting in significant impacts. With implementation of MM GEO-1, impacts related to land subsidence due to seismic-related processes would be less than significant.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 47 Soil liquefaction occurs when soil material loses strength in response to strong ground shaking.
Liquefaction normally occurs under saturated conditions in soils, such as sand; however, liquefaction is not exclusively limited to sandy substrate. In accordance with the State of California Seismic Hazard Zones Map, the site is located within a potential liquefaction zone. The project-specific geotechnical study (GeoSoils 2022) evaluated the potential for liquefaction within the project site and concluded that there is a potential for liquefaction-induced seismic settlement in the area of study. With implementation of MM GEO-1, impacts related to soil liquefaction would be less than significant.
Soil collapse occurs when sediment moisture content increases substantially, leading to the densification of the soil, which can lead to structural damage from cracking foundations, walls, and floors. Typical causes of soil collapse include infiltration resulting from poor surface drainage, irrigation water, or leaking pipes into low-density, silty sandy soil in semi-arid and arid climates that are not regularly subjected to saturation. According to the NRCS (2023) soil survey data, the frequency of flooding and ponding in the project site is none. The soils within the project site are generally dense and moist with depth and are moderately compressible under saturated conditions. As such, construction of the project on these soils could result in significant impacts related to collapse. However, MM GEO-1, which requires the collapsible or weak soils to be removed during the site preparation phase of project construction,47ould be implemented. The soils would be moisture-conditioned to at least optimum moisture content and then recompacted to a minimum of 95% of the maximum dry density. With implementation of MM GEO-1, impacts related to collapse 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?
No Impact. Expansive soils are clay-based and tend to increase in volume due to water absorption and decrease in water volume due to drying. Expansive soils can result in structural damage, particularly if wetting and drying do not occur uniformly throughout the soil. The project-specific geotechnical study (GeoSoils 2022) concluded that soils within and underlying the project site have very low expansive potential. Additionally, implementation of MM GEO-1 would result in over-excavation and replacement of soils to specified depths (see above) that would ensure only engineered fill would be used within the project site, thereby eliminating the concern of expansive soils. Therefore, there is no impact potential for expansive soils within the project site.
e) Would the project have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater?
No Impact. The project includes the extension of sewer lines and does not involve construction of septic tanks or alternative wastewater disposal systems. Therefore, no impact would occur. 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. According to the Society of Vertebrate Paleontology (SVP), unique paleontological (i.e., scientifically significant fossils) are most intact large or small vertebrate fossils, or uncommon invertebrate, plant, and trace fossils (SVP 2010). Paleontological resources are considered to be older than recorded human history and/or older than middle Holocene (i.e., older than about 5,000 radiocarbon years) (SVP 2010). Significance criteria of fossil discoveries are linked to scientific, cultural, and/or educational importance, particularly in relation to taphonomic, taxonomic, phylogenetic, paleoecologic, stratigraphic, and/or biochronologic information that they can provide (Murphey et al. 2019; Scott and Springer 2003). Geologic units known to preserve significant Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 48 fossils or fossil localities are likely to contain additional undiscovered and potentially significant fossils and are generally considered sensitive for paleontological resources throughout their areal and stratigraphic extent. Unique geologic features may include, rock outcrops, rare sedimentary structures, arches, hoodoos, etc., and are generally irrelevant to urban settings, such as the project site.
SWCA conducted a paleontological resources assessment, provided as Appendix E: Paleontological Resources Technical Memorandum, which included a review of geotechnical information, geologic maps, scientific literature, and museum records (SWCA 2023; see Appendix E), to determine the potential for impacts to paleontological resources. The geotechnical investigation notes the presence of unmapped artificial fill at the surface to approximately depths as deep as 6 feet below ground surface (GeoSoils 2022), and geologic mapping by Campbell and others (2014) indicates the surficial sediments within the project site are Holocene and late Pleistocene young alluvium, undivided (Qya) and Pleistocene to late Pliocene Saugus Formation, undivided (QTs). Ground-disturbing activities greater than or equal to 5 feet below ground surface in areas mapped at the surface as Qya may result in adverse effects on significant paleontological resources. Moreover, ground-disturbing activities in areas mapped at the surface as QTs (regardless of depth) may also result in adverse effects on significant paleontological resources. The implementation of MM GEO-2 would ensure that fossils, if encountered, are assessed for significance and, if significant, salvaged and curated with an accredited repository.
Conclusion
The project would include implementation of MM GEO-1 and MM GEO-2. Upon implementation of these project-specific mitigation measures, impacts to geology and soils would be less than significant with mitigation incorporated.
Mitigation Measures
MM GEO-1 Structural Engineering and Setback Requirements. Prior to issuance of a grading permit, the Applicant shall consult a qualified structural engineer regarding the design of structural components (i.e., floor slab support) of the building to reduce adverse impacts associated with fault rupture, strong seismic ground shaking, ground failure, and liquefaction. Design elements of structures for human occupancy should include a setback of 75 feet from the San Gabriel Fault, and pipelines (including gas, water, storm drain, and sewer) shall be constructed to allow flexure (Allan E. Seward Engineering Geology, Inc. 2007).
During construction of the proposed project, the developer shall implement all recommendations provided in the project-specific geotechnical study, including, but not limited to, removal of unsuitable soils and uncertified fills, and over-excavation and recompacting of soils within the project site. Typical hillside grading development and grading ground improvement shall be implemented to withstand the anticipated ground shaking and static and seismic-induced settlement.
MM GEO-2 Paleontological Resource Monitoring. The developer shall implement the following:
a. Retain a Qualified Professional Paleontologist: A Project Paleontologist, defined as one who meets the Society of Vertebrate Paleontology standards for a qualified professional paleontologist, should be retained to carry out all regulatory compliance measures and protocols related to paleontological resources.
b. Conduct Worker Training: The Project Paleontologist should develop WEAP training to educate the construction crew on the legal requirements for preserving fossil resources, as well as the procedures to follow in the event of a fossil discovery. This training program should be given Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 49 to the crew before ground-disturbing work begins and should include handouts to be given to new workers as needed.
c. Monitor for Paleontological Resources: Full-time monitoring should be required in areas mapped as Holocene and late Pleistocene young alluvium, undivided (Qya) when ground- disturbing activities impact previously undisturbed sediments greater than or equal to 5 feet below ground surface, or in areas mapped as Pleistocene to late Pliocene Saugus Formation, undivided (QTs) (regardless of depth). Monitoring should not be required when ground- disturbing activities impact only artificial fill, previously disturbed sediments, and areas mapped as Qya at depths less than 5 feet below ground surface.
Monitoring should be conducted by a paleontological monitor who meets the standards of the SVP and should be supervised by the Project Paleontologist, who may periodically inspect construction activities to adjust the level of monitoring in response to subsurface conditions.
Monitoring efforts can be increased, reduced, or ceased entirely if determined adequate by the Project Paleontologist in consultation with the Applicant and the City. Paleontological monitoring should include inspection of exposed sedimentary units during active excavations within sensitive geologic sediments. The monitor should have authority to temporarily divert activity away from exposed fossils to evaluate the significance of the find and, should the fossils be determined significant, professionally and efficiently recover the fossil specimens and collect associated data.
The monitor should record pertinent geologic data and collect appropriate sediment samples from any fossil localities. Recovered fossils should be prepared to the point of curation, identified by qualified experts, listed in a database to facilitate analysis, and deposited in a designated paleontological repository (e.g., Natural History Museum of Los Angeles County). d. Prepare a Paleontological Resources Monitoring Report: Upon conclusion of ground- disturbing activities, the Project Paleontologist overseeing paleontological monitoring should prepare a final paleontological resources monitoring report that documents the paleontological monitoring efforts for the project and describes any paleontological resources discoveries observed and/or recorded during the life of the project. If paleontological resources are curated, the final report and any associated data pertinent to the curated specimen(s) should be submitted to the designated repository. A copy of the final report should be filed with the City.
VIII. Greenhouse Gas Emissions
Environmental Issues Potentially
Significant Impact
Less Than
Significant with
Mitigation
Incorporated
Less
Than
Significan
t Impact
No
Impact
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?
☐ ☐ ☒ ☐
The analysis for this section is based on the project’s Air Quality, Energy, and Greenhouse Gas Technical Memorandum, included as Appendix A (LSA 2024a).
Setting
Greenhouse gases (GHGs) are gases that absorb infrared radiation in the atmosphere. The greenhouse effect is a natural process that contributes to regulating the Earth’s temperature. Global climate change Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 50 concerns are focused on whether human activities are leading to an enhancement of the greenhouse effect.
Principal GHGs include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), O3, and water vapor.
Each GHG differs in its mass and ability to trap heat within the atmosphere based on factors such as capacity to directly absorb radiation, length of time in the atmosphere, and chemical transformations that create new GHGs. Because the warming potential of each GHG differs, GHG emissions are typically expressed in terms of CO
2 equivalents (CO2e), providing a common expression for the combined volume and warming potential of the GHGs generated by an emitter. Total GHG emissions from individual sources are generally reported in metric tons (MT) and expressed as metric tons of CO2 equivalents (MTCO2e).
Global climate change is a cumulative impact; a project participates in this potential impact through its incremental contribution combined with the cumulative increase of all other sources of GHGs. There are currently no established thresholds for assessing whether the GHG emissions of a project in the SCAB, such as the project, would be considered a cumulatively considerable contribution to global climate change; however, all reasonable efforts should be made to minimize a project’s contribution to global climate change. In addition, while GHG impacts are recognized exclusively as cumulative impacts (California Air Pollution Control Officers Association [CAPCOA] 2008), GHG emissions impacts must also be evaluated at a project level under CEQA. A detailed discussion of methodologies for performing project-level GHG assessments, including State CEQA Guidelines, SCAQMD recommendations, and the guidance set forth City of Santa Clarita General Plan, is provided in Appendix A.
State CEQA Guidelines Section 15064.4 recommends that lead agencies quantify GHG emissions of projects and consider several other factors that may be used in the determination of significance of GHG emissions from a project, including the extent to which a project may increase or reduce GHG emissions; whether a project exceeds an applicable significance threshold; and the extent to which a project complies with regulations or requirements adopted to implement a plan for the reduction or mitigation of GHG emissions. The State CEQA Guidelines do not establish a threshold of significance. Rather, lead agencies, such as the City of Santa Clarita, have the discretion to establish significance thresholds for their respective jurisdictions. In establishing those thresholds, the lead agency may appropriately look to thresholds developed by other public agencies or suggested by other experts, as long as any threshold chosen is supported by substantial evidence (State CEQA Guidelines Section 15064.7[c]).
A project’s incremental contribution to a cumulative impact can be found not cumulatively considerable if the project would comply with an approved plan or mitigation program that provides specific requirements that would avoid or substantially lessen the cumulative problem in the geographic area of the project. To qualify, such plans or programs must be specified in law or adopted by the public agency with jurisdiction over the affected resources through a public review process to implement, interpret, or make specific the law enforced or administered by the public agency. Examples of such programs include a water quality control plan (Basin Plan), air quality attainment or maintenance plan, integrated waste management plan, habitat conservation plan, natural community conservation plans, and plans or regulations for the reduction of GHG emissions.
Therefore, a lead agency can make a finding of less than significant for GHG emissions if a project complies with adopted programs, plans, policies, and/or other regulatory strategies to reduce GHG emissions. A project would be considered consistent with applicable plans, policies, and regulations adopted for the purpose of reducing GHG emissions if a qualitative analysis demonstrates that the project meets the general intent in reducing GHG emissions in order to facilitate the achievement of local- and State-adopted goals and does not impede attainment of those goals.
In the absence of any adopted numeric threshold, the significance of a project’s GHG emissions is evaluated consistent with State CEQA Guidelines Section 15064.4(b) by considering whether the project complies with applicable plans, policies, regulations, and requirements adopted to implement a statewide, Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 51 regional, or local plan for the reduction or mitigation of GHG emissions. For this project, as a land use development project, the most directly applicable adopted regulatory plan to reduce GHG emissions is SCAG’s 2020-2045 RTP/SCS, which is designed to achieve regional GHG reductions from the land use and transportation sectors as required by SB 375 and the State’s long-term climate goals (SCAG 2020a).
This analysis also considers consistency with regulations or requirements adopted by the 2008 Climate Change Scoping Plan and subsequent updates (CARB 2008, 2022).
Environmental Evaluation
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 City of Santa Clarita has not adopted a numerical significance threshold for assessing impacts related to GHG emissions. Similarly, the SCAQMD, CARB, and all state and regional agencies have not yet adopted numerical significance thresholds for assessing GHG emissions that are applicable to the project. Notwithstanding, the following analysis calculates the amount of GHG emissions that would be attributable to the project using the recommended air quality model, CalEEMod (see Section III, Air Quality). Further, in the absence of any adopted numerical threshold, the significance of project-related GHG emissions is evaluated by considering whether the project is consistent with applicable plans, policies, and regulations that have been established to reduce or mitigate GHG emissions. For the project, the relevant adopted regulatory plans include the CARB 2022 Scoping Plan, and the 2020-2045 RTP/SCS.
This following analysis describes the proposed project’s construction- and operation-related GHG emissions and contribution to global climate change.
Construction Emissions
Construction activities associated with the proposed project would produce combustion emissions from various sources. During construction, GHGs would be emitted through the operation of construction equipment and from worker and builder supply vendor vehicles, each of which typically use fossil-based fuels to operate. The combustion of fossil-based fuels creates GHGs such as CO 2, CH4, and N2O.
Furthermore, CH4 is emitted during the fueling of heavy equipment. Exhaust emissions from on-site construction activities would vary daily as construction activity levels change.
Exhaust emissions from on-site construction activities would vary daily as construction activity levels change. The SCAQMD does not have an adopted threshold of significance for construction-related GHG emissions. However, lead agencies are required to quantify and disclose GHG emissions that would occur during construction. The SCAQMD then suggests that the construction GHG emissions to be amortized over the life of the project, defined by the SCAQMD as 30 years, added to the operational emissions, and compared to the applicable interim GHG significance threshold tier.
As indicated above, the SCAQMD does not have an adopted threshold of significance for construction- related GHG emissions. However, lead agencies are required to quantify and disclose GHG emissions that would occur during construction. Using CalEEMod, it is estimated that the project would generate approximately 1,447.8 MT CO2e during construction of the project. When annualized over the 30-year life of the project, annual emissions would be 48.3 MT CO2e.
As with project-generated construction criteria air pollutant emissions, GHG emissions generated during construction of the 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.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 52 Operational Emissions
Long-term GHG emissions are typically generated from mobile sources (e.g., vehicle trips), area sources (e.g., maintenance activities and landscaping), offroad sources (e.g., use of the operational equipment), stationary sources (e.g., the diesel backup generator), indirect emissions from sources associated with energy consumption, waste sources (land filling and waste disposal), and water sources (water supply and conveyance, treatment, and distribution). Mobile-source GHG emissions would include project-generated vehicle trips to and from the project. Area-source emissions would be associated with activities such as landscaping and maintenance on the project site. Energy source emissions would be generated at off-site utility providers because of increased electricity demand generated by the project. Waste source emissions generated by the proposed project include energy generated by land filling and other methods of disposal related to transporting and managing project-generated waste. In addition, water source emissions associated with the proposed project are generated by water supply and conveyance, water treatment, water distribution, and wastewater treatment.
In accordance with CEQA Guidelines Section 15064.4(c), GHG emissions were estimated for the proposed project using CalEEMod. Table 8 shows the calculated operational GHG emissions for the project.
Table 8. Estimated Annual Operation GHG Emissions
Emissions Source CO2 CH4 N2O CO2e
Mobile Sources 3,939.1 0.2 0.2 3,997.4
Area Sources 26.7 <0.1 <0.1 26.8
Energy Sources 829.3 0.1 <0.1 832.4
Water Sources 85.9 1.3 <0.1 128.60
Waste Sources 35.2 3.5 0.1 123.20
Offroad Sources 350.5 <0.1 <0.1 351.7
Stationary Sources 9.5 <0.1 <0.1 9.6
Total Project Operational Emissions 5,469.7
Amortized Construction Emissions 48.30
Total Annul Emissions 5,518.0
Notes: CO2 = carbon dioxide; CH4 = methane; N2O = nitrous oxide; CO2e = carbon dioxide equivalent.
See Appendix A for complete results.
As shown in Table 8, estimated annual project-generated operational GHG emissions would be approximately 5,469.7 MT CO2e per year; with amortized construction emissions of approximately 48.3 MT CO2e per year, total project emissions would be approximately 5,518 MT CO2e per year.
As previously discussed, there are currently no established thresholds for assessing whether the GHG emissions of a project in the SCAB would result in a significant impact to the environment, and there are currently no mandatory GHG regulations or finalized agency guidelines that would apply to implementation of this project. In the absence of any adopted numeric threshold, the significance of a project’s GHG emissions is evaluated consistent with State CEQA Guidelines Section 15064.4(b) by considering whether the project complies with applicable plans, policies, regulations, and requirements adopted to implement a statewide, regional, or local plan for the reduction or mitigation of GHG emissions. This consistency analysis is provided below in Threshold VIII(b). Given the project is consistent with the regulations adopted for reducing GHG emissions, the project’s generation of greenhouse gas emissions would be less than significant.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 53 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. Appendix A provides analysis of the project’s consistency with the following regulations or requirements adopted for reducing GHG emissions: CARB’s 2022 Scoping Plan and SCAG’s 2020-2045 RTP/SCS. Additionally, the project would adhere to all requirements of the City of Santa Clarita General Plan.
CARB’s 2022 Scoping Plan
The Scoping Plan (approved by CARB in 2008 and updated in 2022) provides a framework for actions to reduce California’s GHG emissions and requires CARB and other state agencies to adopt regulations and other initiatives to reduce GHGs (CARB 2008, 2014, 2017). The Scoping Plan is not directly applicable to specific projects, nor is it intended to be used for project-level evaluations.2 It does provide recommendations for lead agencies to develop evidence-based numeric thresholds consistent with the Scoping Plan, the State’s long-term GHG goals, and climate change science. Under the Scoping Plan, however, there are several state regulatory measures aimed at the identification and reduction of GHG emissions. CARB and other state agencies have adopted many of the measures identified in the Scoping Plan. Most of these measures focus on area source emissions (e.g., energy usage, high-global warming potential GHGs in consumer products) and changes to the vehicle fleet (i.e., hybrid, electric, and more fuel-efficient vehicles) and associated fuels (e.g., Low Carbon Fuel Standard), among others.
The Scoping Plan recommends strategies for implementation at the statewide level to meet the goals of Assembly Bill (AB) 32 and establishes an overall framework for the measures that would be adopted to reduce California’s GHG emissions. Appendix A highlights measures that have been, or would be, developed under the Scoping Plan and presents the project’s consistency with Scoping Plan measures.
The project would comply with all regulations adopted in furtherance of the Scoping Plan to the extent required by law and to the extent that they are applicable to the project.
Senate Bill 375 (Southern California Association of Governments Regional Transportation Plan/Sustainable Communities Strategy)
The SCAG 2020-2045 RTP/SCS is a regional growth management strategy that targets per-capita GHG reduction from passenger vehicles and light trucks in the Southern California region pursuant to SB 375. In addition to demonstrating the region’s ability to attain the GHG emission-reduction targets set forth by CARB, the 2020-2045 RTP/SCS outlines a series of actions and strategies for integrating the transportation network with an overall land use pattern that responds to projected growth, housing needs, changing demographics, and transportation demands. Thus, successful implementation of the 2020-2045 RTP/SCS would result in more complete communities with a variety of transportation and housing choices, while reducing automobile use.
The strategies shown in Appendix A are intended to be supportive of implementing the 2020-2045 RTP/SCS and reducing GHGs: Better manage the existing transportation system through design management strategies, integrate land use decisions and technological advancements, create complete streets that are safe to all roadway users, preserve the transportation system and expand transit and foster development in transit-oriented communities (LSA 2024a). The project would not conflict with any strategies of the SCAG 2020-2045 RTP/SCS.
2 The Final Statement of Reasons for the amendments to the State CEQA Guidelines reiterates the statement in the Initial Statement of Reasons that “[t]he Scoping Plan may not be appropriate for use in determining the significance of individual projects because it is conceptual at this stage and relies on the future development of regulations to implement the strategies identified in the Scoping Plan” (California Natural Resources Agency 2009:97–98).
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 54 City of Santa Clarita General Plan
The City of Santa Clarita General Plan defines a local threshold of significance for GHG emissions for project-level submittals that trigger CEQA review. Because goals, objectives, and policies approved under the General Plan are forecast to meet the GHG emission reduction targets mandated by AB 32 and SB 375, development projects that can demonstrate consistency with the General Plan would by association demonstrate consistency with AB 32.
Summary
As discussed, the project is consistent with the GHG emission reduction measures in the CARB Scoping Plan and would not conflict with the state’s trajectory toward future GHG reductions. In addition, since the specific path to compliance for the state in regard to the long-term goals would likely require development of technology or other changes that are not currently known or available, specific additional mitigation measures for the project would be speculative and cannot be identified at this time.
The project’s consistency would assist in meeting the City’s contribution to GHG emission reduction targets in California. With respect to future GHG targets under SB 32 and Executive Order S-03-05, CARB has also made clear its legal interpretation is that it has the requisite authority to adopt whatever regulations are necessary, beyond the AB 32 horizon year of 2020, to meet SB 32’s 40% reduction target by 2030 and Executive Order S-03-05’s 80% reduction target by 2050; this legal interpretation by an expert agency provides evidence that future regulations would be adopted to continue the state on its trajectory toward meeting these future GHG targets. Based on the considerations previously outlined, the project would not conflict with an applicable plan, policy, or regulation adopted for the purpose of reducing the emissions of GHGs. Therefore, the project’s impact associated with an applicable plan, policy, or regulation adopted for the purpose of reducing the emissions of GHGs would be less than significant.
Conclusion
The project would not result in a significant adverse impact to greenhouse gas emissions; no mitigation measures are necessary.
IX. Hazards and Hazardous Materials
Environmental Issues Potentially
Significant Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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?
☐ ☐ ☒ ☐
(c) Emit hazardous emissions or handle hazardous or
acutely hazardous materials, substances, or waste
within 0.25 mile of an existing or proposed school?
☐ ☐ ☐ ☒
(d) Be located on a site which 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?
☐ ☐ ☐ ☒
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 55 Environmental Issues Potentially
Significant Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
(e) For a project located within an airport land use plan or, where such a plan has not been adopted, within 2
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 site?
☐ ☐ ☐ ☒
(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?
☐ ☐ ☒ ☐
The information in this section of this IS/MND is based on the following two reports:
• Hazardous Materials Assessment for Riverview Development Project, dated March 6, 2024, (Dudek 2024d) which is provided as Appendix F: Hazardous Materials Assessment. • Technical Review Memorandum and Summary of Environmental Activities – The Riverview Project, dated November 16, 2022, prepared by Ninyo & Moore Geotechnical & Environmental Sciences Consultants (Ninyo & Moore); included as Appendix G: Hazardous Materials Technical Memorandum to this IS/MND (Ninyo & Moore 2022)
Setting
The project site is located on the former Saugus Speedway in the city of Santa Clarita, which is bordered by Soledad Canyon Road and the Santa Clara River to the north-northeast and the Metrolink rail line to the south-southwest. The average elevation of the project site ranges approximately between 1,185 and 1,296 feet amsl. Surrounding land uses include the Santa Clara River and floodplain followed by residential to the north and northeast, commercial to the southeast and northwest, Metrolink rail line and undeveloped hillsides to the south, and a family counseling center, Action Family Rehab, located approximately 650 feet west of the project site. The depth to groundwater on the project site, according to 2020 groundwater monitoring, ranges between approximately 20 and 30 feet below ground surface, and groundwater flow direction is toward the west-northwest. Yearly variation in depth to groundwater is common in areas of the project site and is highly dependent on precipitation and recharge from the nearby Santa Clara River (Dudek 2024d). No active oil and gas wells were identified within 1 mile of the project site, and one natural gas pipeline is located approximately 0.6 mile southwest of the project site along Springbook Avenue (Dudek 2024d).
The closest water supply well was identified approximately 330 feet east of the project site.
A decommissioned municipal well, with no available water level data, was identified along the northern boundary of the project site. Six groundwater monitoring wells are located on the project site: two north of the racetrack, two near the center, and two on the hill in the west of the project site. These wells and a large number of additional monitoring wells located southeast of the project site are related to the Whittaker/Bermite cleanup site, which covered over 900 acres in the hills adjacent and to the south of the project site. The Whittaker/Bermite facility manufactured, stored, and tested explosives from 1934 to 1987. Contaminated groundwater was identified at the project site as a result of the Whittaker/Bermite facility, and remediation activities have successfully reduced the extent of groundwater contamination in the area, including that which impacted the project site. As of May 2020, groundwater monitoring wells on the project site do not have detectable concentrations of tetrachloroethylene (PCE) and trichloroethylene.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 56 The project site is identified in the EnviroStor database as a voluntary cleanup site. In 2007, a preliminary endangerment assessment (PEA) was completed for the project site (Avocet 2007). The PEA evaluated site conditions and the potential for environmental contamination related to historical site use and adjoining contaminated sites. This included historical agricultural use (pesticides/herbicides), automotive use (petroleum hydrocarbons, metals, polyaromatic hydrocarbons, polychlorinated biphenyls, and VOCs), the adjoining Whittaker/Bermite Facility (VOCs), and buildings with lead-based paint (lead).
The PEA identified VOCs and perchlorate in the groundwater on the project site that originated from the Whittaker/Bermite site (Avocet 2007). The PEA also identified lead concentrations in soil above regulatory screening levels applicable at that time, which were believed to be attributed to lead-based paint on existing site structures (Avocet 2007). The 2007 PEA references five underground storage tanks containing fuel and potentially heating oil. While all five former tanks were believed to have been removed, evidence of removal for only three was identified (Avocet 2007).
Additional investigations were completed between 2007 and 2021, and in that time groundwater remediation was conducted at the former Whittaker/Bermite Facility. Many of the structures believed to have lead-based paints were also removed. A 2021 Phase II subsurface investigation was completed on the project site, which included collection of 21 soil samples and installation and sampling of 12 dual- depth soil vapor probes on the project site. VOCs were not identified in soil vapor above applicable risk- based levels (with the exception of one sample, discussed below), and elevated concentrations of lead above applicable screening levels were not observed in soil (Department of Toxic Substances Control [DTSC] 2021; GSI Environmental, Inc. 2021). DTSC agreed that no further risk to human health was present and issued a no further action (NFA) determination for the project site with approved unrestricted land use (DTSC 2021).
The project site was also identified on the GeoTracker and California Environmental Protection Agency (CalEPA) databases (State Water Resources Control Board [SWRCB] 2022). The GeoTracker listing is for waste discharge requirements related to car wash activities beginning in 1975. This case was last inspected in August 2002 and is now closed and considered “historical.” The project site is listed on the CalEPA database as a hazardous waste generator and a chemical storage facility, containing propane and diesel fuel.
Environmental Evaluation
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 with Mitigation Incorporated. Construction activities associated with the project would involve the routine transport, use, or disposal of hazardous materials such as fuels, lubricants, paints, and solvents associated with construction vehicles, equipment, and supplies.
The project would require heavy equipment (e.g., dozers, excavators, tractors) operation at the project site during construction. Heavy equipment is typically fueled and maintained by petroleum‐based substances such as diesel fuel, gasoline, oil, and hydraulic fluid, which is considered hazardous if improperly stored or handled. Improper use, storage, or transportation of hazardous materials can result in accidental releases or spills, potentially posing health risks to workers, the public, and the environment. This is a standard risk on all construction sites, and there would be no greater risk for improper handling, transportation, or spills associated with the project than would occur on any other similar construction site. Construction contractors would be required to comply with all applicable federal, state, and local laws and regulations regarding the transport, use, and storage of hazardous construction-related materials.
Relevant state regulations include the California Occupational Safety and Health Administration, CCR Title 8, which establishes occupational health and safety standards related to employee training, availability of safety equipment, accident prevention programs, and hazardous substance exposure Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 57 warnings. CCR Title 8 also requires the construction contractor to implement a communication program that includes label warnings, safety data sheets, and information and training for workers about the chemicals to which they could be exposed. Relevant local requirements include Section 10.04.070 of the City Municipal Code, which identifies construction stormwater measures that would be implemented prior to and during construction.
Construction activities would also involve the excavation of soil; ground-disturbing activities associated with project construction include grading approximately 500,000 cubic yards of cut and approximately 420,000 cubic yards of fill, with the entirety of the site being graded and raised approximately 10 feet on average. Based on the environmental assessments and investigations prepared for the project as summarized in the findings of the Hazardous Materials Assessment (Dudek 2024d), it is possible that contaminated soils would have the potential to create a hazard to workers at the site during construction activities and impacts could be potentially significant. Implementation of MM HAZ-1 would include the preparation of a Soil Management Plan to identify the protocols for excavation, temporary stockpiling, handling, and disposal of impacted soil that may be encountered at the project site. The Soil Management Plan would also provide guidance for monitoring requirements to be followed during excavation activities, stockpiling procedures, excavated soil waste characterization requirements, soil disposal requirements based on waste characterization, sampling and analyses requirements in the event impacted soil is detected, soil screening levels, and regulatory reporting requirements.
Operation of the proposed project would include use of minor quantities of commercially available hazardous materials, such as paints, lubricants, pool cleaners/chlorine, cleansers, pesticides, fertilizers, and miscellaneous organics and inorganics that may be used by the residents of the new homes for landscaping, vehicle maintenance, household cleaning, and drainage maintenance activities. In the event that these materials are handled improperly or released to the environment during transport, use, and/or disposal, they can create hazards for the public and/or the environment. However, these materials are not considered acutely hazardous and are used routinely throughout urban environments for operation of commercial businesses. Handling, storage, and disposal of these hazardous materials would comply with all federal, state, and local requirements, including training of operational staff on proper handling.
Furthermore, the County of Los Angeles and the City have programs in place to encourage safe and proper disposal of such materials. For example, the City has household hazardous waste collections (1-day events hosted by the Los Angeles County Sanitation District and the LACDPW), which allow residents to safely dispose of their hazardous wastes. Residents are also able to dispose of their hazardous wastes safely at Solvents/Automotive/Flammables/Electronics (S.A.F.E.) collection centers, which are open every weekend and are operated by the City of Los Angeles Sanitation Department. The closest S.A.F.E. Center to the project site is located at 11025 Randall Street in Sun Valley, California. Through compliance with local, state, and federal regulations, in conjunction with local programs that encourage safe disposal of hazardous materials, implementation of the proposed project would not create a significant hazard to the public or to the environment through the routine transport, use, or disposal of hazardous materials. The proposed project would result in less-than-significant impacts regarding creation of hazards to the public or the environment through the routine transport, use, or disposal of hazardous materials, and no mitigation measures are necessary.
With adherence to applicable federal, state, and local laws and regulations regarding the transport, use, and storage of hazardous construction-related materials as well as implementation of MM HAZ-1 (Soil Management Plan), construction-related impacts associated with the routine transport, use, or disposal of hazardous materials would be less than significant with mitigation incorporated.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 58 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. Accidents involving hazardous materials that could pose a significant hazard to the public or the environment would be highly unlikely during the construction and long-term operation of the project and are not reasonably foreseeable. As discussed above, the transport, use, and handling of hazardous materials on the project site during construction is a standard risk on all construction sites, and there would be no greater risk for upset and accidents than would occur on any other similar construction site. Upon buildout, the project site would operate as a housing complex.
Based on the operational characteristics of homes, it is possible that hazardous materials could be used during the course of a future occupant’s daily operations; however, as discussed above, household items are not acutely hazardous, are used intermittently, and are disposed of in the recommended fashion.
The Applicant would be required to comply with all applicable local, state, and federal regulations related to the transport, handling, and use of hazardous material. Accordingly, impacts associated with the accidental release of hazardous materials would be less than significant during both construction and long-term operation of the project and no mitigation measures are necessary. c) Would the project emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within 0.25 mile of an existing or proposed school?
Less than Significant Impact. No schools are located within 0.25 mile of the project site. There are three schools located approximately 0.75 mile to the southeast on Centre Point Parkway: two preschools, Notre Dame Children’s Academy and Creative Years Infant Center and Preschool, and one high school, Bowman High School.
As described above, the use of and transport of hazardous substances or materials to-and-from the project site during construction and long-term operational activities would be required to comply with applicable federal, state, and local regulations that would preclude substantial public safety hazards. Accordingly, there would be no potential for existing or proposed schools to be exposed to substantial safety hazards associated with emission, handling of, or the routine transport of hazardous substances or materials to- and-from the project site and impacts would be less than significant.
Refer to Section III, Air Quality, for analysis pertaining to human health risks associated with air pollutant emissions associated with the project. As concluded in Section III, the project’s toxic air contaminant emissions (and their associated health risks) would be less than significant. d) Would the project be located on a site which 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? Less than Significant Impact. The Hazardous Materials Assessment, included as Appendix F, shows that Dudek performed a search of regulatory databases, including DTSC’s EnviroStor database (EDR), CalEPA’s SWRCB GeoTracker database, State Water Resources Control Board list of solid waste disposal sites, active Cease and Desist Orders and Cleanup and Abatement Orders, and hazardous waste facilities pursuant to Section 25187.5 of the Health and Safety Code.
The Dudek search identified that the GeoTracker and California Environmental Protection Agency (CalEPA) databases (State Water Resources Control Board [SWRCB] 2022) designate the project site as containing hazardous materials. The GeoTracker listing is for waste discharge requirements related to car wash activities beginning in 1975. This case was last inspected in August 2002, and is now closed and Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 59 considered “historical.” The project site is listed on the CalEPA database as a hazardous waste generator and a chemical storage facility, containing propane and diesel fuel, related to the previous use as a motor speedway.
The removal of existing infrastructure and hazardous materials from the project site during construction, and continued remediation of the Whittaker/Bermite Facility would ensure that inhabitants of the project site would not be impacted by hazardous materials and impacts would be less than significant. e) For a project located within an airport land use plan or, where such a plan has not been adopted, within 2 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 site?
No Impact. The project site is not located within 2 miles of a public use airport, nor is it located within an airport land use plan. In addition, according to correspondence between the City and the Applicant, the City confirms the proposed building roof elevation would not conflict with the helicopter flight path.
Therefore, the project would not result in a safety hazard or excessive noise for people residing or working in the area. No impact would occur.
f) Would the project impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan?
Less than Significant Impact. The City’s General Plan and the County of Los Angeles Operational Area Disaster Route map for the City designate Interstate 5 (I-5), State Route (SR-) 14 and SR-126 as emergency evacuation routes (LACDPW 2010). The project site is not located within the vicinity of these evacuation routes and is not expected to disrupt evacuation procedures along these highways. The County designates Soledad Canyon Road as a secondary evacuation route, which acts as the northeastern project boundary.
Any public right-of-way encroachments during project construction would require approval from the City. As described in Section XVII, Transportation, project-generated traffic would not substantially adversely affect the performance of nearby roadways, including Soledad Canyon Road. Therefore, emergency service response times and disaster evacuation routes would not be affected. Prior to operation, the proposed project would receive all required permits and certificates for occupancy and operation, including those issued by the City Department of Building and Safety. Therefore, the project would not substantially interfere with or impair local emergency response or emergency evacuation plans, and impacts would be less than significant.
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. The project site is not located within a Fire Hazard Severity Zone (FHSZ) The project site is located within a Very High Fire Hazard Severity Zone (FHSZ) in a Local Responsibility Area (California Department of Forestry and Fire Protection [CAL FIRE] 2024 Fire and Resource Assessment Program 2022; City of Santa Clarita 2020a). Regardless of the project’s location outside of an FHSZ, the The project is located adjacent to arid open space with low-lying vegetation, and wildfire potential exists. The project would be designed to comply with all fire safety rules and regulations, including the California Fire Code and Public Resources Code. Additionally, the Los Angeles County Fire Department would review the project site plans prior to issuance of building permits.
Therefore, impacts would be less than significant. For additional wildfire analysis, please refer to Section XX, Wildfire, below.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 60 Conclusion
With implementation of MM HAZ-1, impacts related to hazards and hazardous materials would be less than significant.
Mitigation Measures
MM HAZ-1 Soil Management Plan. The developer and/or project contractor shall prepare and implement a Soil Management Plan for the removal of any identified contaminated soils and their transportation off-site. The Soil Management Plan shall be prepared in coordination with the City and the Los Angeles County Fire Department (as the Certified Unified Program Agency) and in accordance with all relevant and applicable federal, state, and local laws and regulations that pertain to the transportation and disposal of hazardous materials and waste. The Soil Management Plan shall:
• describe the methodology to identify and manage (reuse or off-site disposal) contaminated soil during soil excavation and/or construction; and • provide protocols for confirmation sampling, segregation and stockpiling, profiling, backfilling, disposal, guidelines for imported soil, and backfill approval from the DTSC Information Advisory on Clean Imported Fill Material.
The Soil Management Plan shall be implemented during project construction.
X. Hydrology and Water Quality
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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 off-site;
☐ ☐ ☒ ☐
(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?
☐ ☐ ☒ ☐
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 61 The information provided in this section is based, in part, on the Hydrology Technical Memorandum for Riverview Development Project, prepared by Dudek, dated November 16, 2022 (Dudek 2022), provided as Appendix H): Hydrology Technical Memorandum.
Setting
The project site is located within the Santa Clara River watershed, which is the largest river system in Southern California that remains in a relatively natural state and drains approximately 1,200 square miles (RWQCB 2022a). The Santa Clara River originates in the northern slope of the San Gabriel Mountains in Los Angeles County and traverses through Ventura County where it eventually empties into the Pacific Ocean between San Buenaventura and Oxnard. The project site is located within the Reach 6 segment of the Santa Clara River of what is defined as the Upper Santa Clara River (Upper Santa Clara River Watershed Management Group 2015). Reach 6 runs between Bouquet Canyon Road Bridge and West Pier Highway 99. According to the RWQCB, Reach 6 of the Santa Clara River is impaired by chlorpyrifos (insecticide), coliform bacteria, diazinon (insecticide), toxicity, and chloride (salts) (RWQCB 2022b). The project site is located immediately southwest Soledad Canyon Road, which traverses the southern bank of the Santa Clara River. Therefore, the Santa Clara River would be considered the nearest receiving body of water for any stormwater runoff discharging from the site.
The Santa Clara River Valley groundwater basin has a total of six subbasins. The project site is located within the Santa Clara River Valley East subbasin (DWR Basin 4-004.07) (California Department of Water Resources [DWR] 2022), the easternmost of the six subbasins.
It is bounded on the north by the Piru Mountains, on the east and southeast by the San Gabriel Mountains, and on the south by the Santa Susannah Mountains (Santa Clarita Valley Groundwater Sustainability Agency [SCV-GSA] 2022). The city of Santa Clarita is near the eastern boundary of this 66,200-acre subbasin. Groundwater is found in the alluvial deposits, terrace deposits, and the Saugus Formation.
While the groundwater is generally unconfined it can also be found as confined or semi-confined within the Saugus Formation (SCV-GSA 2022). The two principal aquifer systems of the subbasin include the alluvial aquifer system which overlies the Saugus Formation (SCV-GSA 2022).
Average annual precipitation in the Santa Clara River Valley ranges from 14 to 16 inches. Rain falling in the upper elevations of the watershed infiltrates into the soil, where some of the water evaporates or is transpired by vegetation and the remainder becomes stormwater that can also infiltrate to underlying groundwater resources. A portion of the runoff occurs as overland flows into side canyons and tributaries to the Santa Clara River. In the urbanized areas, precipitation falling on impervious surfaces is directed to storm drains that flow to the river or the stormwater is directed to swales and allowed to infiltrate locally (SCV-GSA 2022).
The subbasin is not adjudicated and in accordance with the California Sustainable Groundwater Management Act is being managed by the SCV-GSA. As required by the Sustainable Groundwater Management Act, the DWR has evaluated the subbasin for sustainability and determined that it is a High Priority basin, with long-term hydrographs showing groundwater levels declining (DWR 2022).
The project site is currently predominantly covered by impervious surfaces (approximately 80%).
Stormwater runoff at the site currently occurs as sheet flows that move from southwest to northeast and into two existing storm drain pipe culverts that are owned/maintained by the County of Los Angeles (RDD 234, Cash Contract No. 2674). A third pipe also collects flows but for just a section of Soledad Canyon Road. These existing pipe culverts convey stormwater under Soledad Canyon Road and outlet to the Santa Clara River on the north side of Soledad Canyon Road. The hillsides southwest of the project site currently drain toward the Metrolink railroad and into three inlets leading to 24-inch pipes that convey the flow under the railroad. The stormwater then sheet-flows across the project site.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 62 According to mapping compiled by the Federal Emergency Management Agency (FEMA), the entire project site is outside of any 100-year flood zone and is located within an area of minimal flood hazard (Zone X) (FEMA 2021a). The floodplain associated with the Santa Clara River is confined and bounded on the south bank, nearest to the project site, by Soledad Canyon Road.
Environmental Evaluation
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. The project would be required to comply with Section 402 of the Clean Water Act, which authorizes the National Pollution Discharge Elimination System (NPDES) permit program that covers point sources of pollution discharging to a water body. The NPDES program also requires operators of construction sites 1 acre or larger to prepare a SWPPP and obtain authorization to discharge stormwater under an NPDES construction stormwater permit. The Applicant also would be required to comply with the California Porter‐Cologne Water Quality Control Act (Section 13000 et seq. of the California Water Code), which requires that comprehensive water quality control plans be developed for all waters within the State of California. The project site is located within the jurisdiction of the Los Angeles RWQCB.
Construction
The project would involve earthwork activities and soil disturbance over the course of construction that could expose soils to the effects of wind and water erosion and sedimentation. Earthwork activities would include grading, excavations for foundations, and trenching for placement of utilities on-site as well as some perimeter areas just outside of the project site boundary. The primary potential pollutant associated with construction activity is sediment (i.e., high turbidity) generated from site preparation and grading activities. Although Reach 6 of the Santa Clara River is listed under Clean Water Act Section 303(d) as impaired for sedimentation/siltation, a measurable increase in sedimentation/siltation from construction activities on the site could temporarily violate Basin Plan objectives, if not properly controlled.
In addition to sediment, other pollutants associated with construction activity could include heavy metals, oil/grease, fuels, demolition debris and trash, and other pollutants from accidental spills or releases of refuse, paints, solvents, sanitary wastes, and concrete curing compounds. Without adequate precautions, wind and/or rain events that occur during construction activities could generate pollutants and/or mobilize sediment such that it contributes to water quality degradation of receiving waters and/or violates Basin Plan objectives.
Standard construction management practices, as required through the Santa Clarita Municipal Code and the statewide NPDES Construction General Permit, would minimize construction-related impacts on water quality. The Construction General Permit would require implementation of a SWPPP to address potential construction-related impacts on water quality. The SWPPP must specify the location, type, and maintenance requirements for BMPs necessary to prevent stormwater runoff from carrying construction- related pollutants into the City’s municipal storm drain system, Santa Clara River, and/or the underlying groundwater basin. BMPs must be implemented to address potential release of fuels, oil, and/or lubricants from construction vehicles and equipment (e.g., drip pans, secondary containment, washing stations); release of sediment from material stockpiles and other construction related excavations (e.g., sediment barriers, soil binders); and other construction-related activities with the potential to adversely affect water quality. The number, type, location, and maintenance requirements of BMPs to be implemented as part of the SWPPP depend on site-specific risk factors such as soil erosivity, construction season/duration, and receiving water sensitivity.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 63 The following list includes examples of treatment control BMPs commonly employed during construction, although these could vary based on the nature of construction activities, the characteristics of the site, and the existing receiving waters impairments (these features would appear as notes on any final design plans):
• Silt fences installed along limits of work and/or the construction site • Stockpile containment (e.g., polyethylene plastic sheeting, fiber rolls, gravel bags) • Exposed soil stabilization structures (e.g., fiber matrix on slopes and construction access stabilization mechanisms)
• Street sweeping
• Tire washes for equipment
• Runoff control devices (e.g., drainage swales, gravel bag barriers/chevrons, velocity check dams) and slope protection
• Drainage system inlet protection
• Wind erosion (dust) controls
• Tracking controls
• Prevention of fluid leaks (inspections and drip pans) from vehicles • Materials pollution management
• Proper waste management (e.g., concrete waste management) • Regular inspections and maintenance of BMPs
The standard requirements contained in a SWPPP, and enforced through the Santa Clarita Municipal Code Chapters 10.04 and 17.90, are sufficient to minimize the project’s potential to violate water quality standards or waste discharge requirements during construction. Therefore, construction-related impacts of the project on water quality would be less than significant.
Operation
Project implementation would involve changes to existing drainage patterns. While the project site is already largely covered in impervious surfaces, estimated at 80%, the proposed changes would increase the impervious surfaces percentage to approximately 85% (Dudek 2022). These changes could become a source of pollution from incidental spills of vehicle oils and other chemicals that can be conveyed by storm and landscape irrigation flows. The impervious surfaces would prevent polluted surface waters from absorbing into the ground surface.
During storm events, pollutants from paved areas lacking in proper stormwater controls and BMPs could enter the municipal storm drain system, before eventually being discharged to the Santa Clara River.
The majority of pollutants entering the storm drain system in this manner could be sediment, nutrients, organic compounds, oxygen demanding substances, trash, debris, bacteria, residual petroleum products (e.g., motor oil, gasoline, diesel fuel), and metals. Certain metals, along with nutrients and pesticides from landscape areas, can also be present in stormwater runoff. Between periods of rainfall, surface pollutants tend to accumulate, and runoff from the first significant storm of the year (“first flush”) would likely have the largest concentration of pollutants.
However, all proposed improvements would be required to adhere to existing drainage control requirements including the Los Angeles County Municipal Separate Storm Sewer System (MS4) Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 64 NPDES permit and the City’s drainage control requirements (Municipal Code Chapter 17.95 - Stormwater Mitigation Plan). Before a building permit is issued, the Applicant would have to submit an Urban Stormwater Mitigation Plan to the City for review and approval. An Urban Stormwater Mitigation Plan has been prepared for the proposed project and demonstrates how the proposed drainage control improvements—a biofiltration basin and biofiltration treatment units—would be incorporated into project design plans to address the specific water quality issues at the site. As part of these requirements, the Urban Stormwater Mitigation Plan identifies that the applicable BMPs are consistent with low-impact development requirements that meet all applicable MS4 permit and City requirements. The proposed project would include this biofiltration basin and biofiltration treatment units to remove a majority of pollutants with a capacity that is adequate to treat all site runoff (Dudek 2022). With adherence to these drainage control requirements, and implementation of post-construction BMPs, water quality concerns would be minimized during operations.
Therefore, compliance with these existing regulatory requirements for drainage control design measures would reduce potential impacts related to water quality standards and waste discharge requirements.
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. There are no groundwater extraction wells currently at the project site and no extraction wells are proposed as part of the project. The project would not include any require deep excavation that would potentially encounter groundwater and thus no dewatering activities would be anticipated during construction.
The proposed project would be served by the Santa Clarita Valley Water Agency (SCV Water) for all water supply demands. The developed project would receive all of its water from a piped water system, connected to an SCV Water water transmission main. According to the 2020 Urban Water Management Plan (UWMP), SCV Water obtains approximately 26% of its water supplies from groundwater (SCV Water 2021). Analysis of projected growth that would include the proposed project and projected supplies, the SCV Water’s demands can be met by supplies in normal, single dry year, and multiple dry- year scenarios, although demands may require some passive and active conservation measures to end up below projected supplies (SCV Water 2021). In addition, according to the groundwater sustainability plan for the underlying groundwater subbasin, “the Basin is not likely to be in an overdraft condition under a sustained level of pumping at the full-build-out level of human demand for groundwater, even under the average climate change scenarios for 2030 and 2070; and the operating plan for the Basin’s groundwater resources is expected to continue maintaining a condition that does not create an overdraft condition (chronic long-term declines in groundwater levels) in the future” (SCV-GSA 2022, Page 6-136).
In addition, the City’s Stormwater Mitigation Plan (Municipal Code Chapter 17.95) requires that projects develop and implement a mitigation plan to lessen the water quality impacts of the project by using smart growth practices and BMPs and integrate low-impact development design principles to mimic pre- development hydrology conditions through infiltration, evapotranspiration, rainfall harvest, and use. The project would include construction of an on-site biofiltration basin would allow much of the stormwater runoff from the site to provide local groundwater recharge.
Therefore, while the project would increase the amount of new impervious surfaces at the site, the site also includes landscaped areas and the biofiltration basin where infiltration would occur during rainstorms. Therefore, the project would not contribute to depletion of groundwater or interfere with recharge of a managed groundwater supply source. Impacts would be less than significant.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 65 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:
c-i) Result in substantial erosion or siltation on- or off-site? Less than Significant Impact. As noted above, the project would alter the existing drainage patterns of the site, although there would only be an approximate 5% increase in impervious surfaces at the site.
The proposed improvements would be required to adhere to MS4 permit requirements and local City drainage control requirements. All runoff from the project would be captured in a private drainage control system that routes through an underground system before eventually tying into the existing storm drainpipe culverts owned/maintained by Los Angeles County (Dudek 2022). Before discharging to the existing storm drain system, the stormwater would be routed to a low-flow splitter. The splitter would send the first-flush flows to the biofiltration basin to be treated. The splitter would convey high flows to the existing downstream storm drain system. For the portion of the site that cannot be treated in the basin, the low flow would be treated in one of two proprietary biofiltration units. Therefore, with adherence to the MS4 permit and local City drainage control requirements (Municipal Code Chapter 17.95 - Stormwater Mitigation Plan), the proposed changes to drainage patterns would not result in erosion or siltation on- or off-site. Impacts would be less than significant. c-ii) Substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off-site;
Less than Significant Impact. As described above under Threshold X(c(i)), the project would alter the existing drainage patterns of the site, although the increase in impervious surfaces would only be from approximately 80% to 85% of the site. However, the project would be required to adhere to MS4 permit requirements and local City drainage control requirements The project’s drainage plan is required to be reviewed and approved by the LACDPW, which would ensure no increase in runoff. Therefore, implementation of the project would not substantially increase the rate or amount of surface water runoff discharged from the site in a manner that would result in flooding on- or off-site. Impacts would be less than significant.
c-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 detailed in the Hydrology Technical Memorandum prepared for the project site, stormwater flows from the site currently occur as sheet flows in a northeast direction and into the two storm drain culverts as well as a third culvert that picks up flow for a section of Soledad Canyon Road (Dudek 2022). According to the analysis of the proposed drainage condition, all developed flows would be below the culvert capacities, and it was determined that these existing culverts can adequately convey the developed flow condition from the project (Dudek 2022). As a result, the project would not increase the rate or amount of surface runoff that would result in flooding on- or off-site, nor would it exceed the capacity of existing stormwater drainage systems. There would also be no other source of polluted runoff that is not already discussed above. Impacts would be less than significant. c-iv) Impede or redirect flood flows?
No Impact. According to FEMA Flood Insurance Rate Map No. 06037C0817G, the project site is within Zone X (FEMA 2021b). The Zone X designation represents areas of minimal flood hazard and is not considered a special flood hazard area. Accordingly, the project site is not expected to be inundated by Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 66 flood flows during the lifetime of the project and the project would not impede flood flows. No impact would occur.
d) In flood hazard, tsunami, or seiche zones, would the project risk release of pollutants due to project inundation?
Less than Significant Impact. The Pacific Ocean is located over 26 miles southwest of the project site; consequently, there is no potential for the project site to be impacted by a tsunami as tsunamis typically only reach up to a few miles inland. The nearest large body of water to the project site is Upper Van Norman Lake, with the dam located approximately 10 miles southeast of the project site. According to City of Santa Clarita General Plan Figure S-4, Special Flood Hazard Areas and Dam Inundation Areas, the project site is not located in an identified inundation area (City of Santa Clarita 2022b); therefore, risk of inundation by dam failure or seiche is low. Additionally, there are no levees in the vicinity of the project site. 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. The project site falls within the jurisdiction of the Los Angeles RWQCB (Region 4) Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties; and the RWQCB is given authority to issue waste discharge requirements, enforce actions against stormwater discharge violators, and monitor water quality. In California, the NPDES stormwater permitting program is administered by the SWRCB. The County of Los Angeles and the City are two of the co-permittees under the Los Angeles County NPDES MS4 permit, and, as such, are required to implement development planning guidance and control measures regarding water quality impacts from new development. The MS4 permit contains provisions for implementation and enforcement of the City’s Urban Stormwater Mitigation Plan. The City supports the requirements of the MS4 permit through Municipal Code Chapters 10.04 and 17.95, which identify requirements for pre- and postconstruction stormwater activities, respectively, for development projects to comply with the NPDES and MS4 permits. The project would comply with the requirements of the City’s Municipal Code Section 10.04.070 (Construction Activity Stormwater Measures) and Chapter 17.95 (Stormwater Mitigation Plan) to ensure impacts to water quality would be less than significant. In addition, as discussed above, the project would be subject to the requirements of the NPDES Construction General Permit, which includes the preparation and implementation of a SWPPP. In regard to sustainable groundwater management, the SCV-GSA has prepared and is implementing the groundwater sustainability plan for the subbasin (SCV-GSA 2022). As the water supplier for the project, SCV Water is also complying with the groundwater sustainability plan and the project is consistent with the projected growth that is accounted for in the plan. Accordingly, the project would not conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan. Impacts would be less than significant.
Conclusion
The project would not result in a significant adverse impact to hydrology and water quality, and no mitigation measures are necessary.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 67 XI. Land Use and Planning
Environmental Issues Potentially
Significant Impact
Less Than Significant
with Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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?
☐ ☐ ☒ ☐
Setting
As identified in the City’s General Plan, the project site’s existing zoning designation is Mixed Use Corridor (MXC) with a Jobs Creation Overlay Zone (JCOZ). The MXC designation encourages development along specified commercial corridors in which revitalization of underutilized parcels or aging buildings is desired. Allowable uses in this designation include single-family, two-family, and multifamily dwellings, banks, lodging, medical services, light manufacturing, schools, public services, and supportive commercial uses with a maximum floor area ratio (FAR) of 1.0. Land use plans, policies, and regulations applicable to the project site and included in the analysis below include the City of Santa Clarita General Plan and Zoning Ordinance.
Environmental Evaluation
a) Would the project physically divide an established community? No Impact. Development of the project would not physically disrupt or divide the arrangement of an established community. Under existing conditions, the project site is vacant and undeveloped. The project vicinity is generally characterized by urban land uses and development, although undeveloped hillsides define the area southwest of the project site. Land uses surrounding the project site include Soledad Canyon Road and Los Angeles Metro rail line to the south, the Los Angeles Metrolink station to the east, and undeveloped hillside to the west. The project would add residential and light manufacturing development to the community that is generally consistent with the land use pattern in the area and what is allowed for and planned in the City’s General Plan. There are no existing communities surrounding or near the project site that are situated in a way that the project would affect how those communities connect or travel between or within themselves. This is largely because the project site does not currently serve as a connection point and is self-contained due to the natural and man-made barriers surrounding the site (e.g., roadways, hillsides/landforms, the Metrolink station, the Santa Clara River and floodplain).
For these reasons, the project would not physically divide an established community. 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?
Less than Significant Impact. Land use plans and policies applicable to the project site are set forth in the City’s General Plan and Zoning Ordinance. An overview of the General Plan and Zoning Ordinance is provided below.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 68 City of Santa Clarita General Plan
The City’s General Plan sets forth an overall vision for the City and the Santa Clarita Valley as a whole, as well as guiding principles for development in the city and goals, policies, and objectives for each of the topics covered by the General Plan elements (i.e., land use, economic development, circulation, noise, conservation and open space, safety, and housing). The overall vision, as stated in the Introduction to the Santa Clarita General Plan, page I-24, is a “mosaic of unique villages with growing ethnic diversity, each with individual identities, surrounded by a greenbelt of forest lands and natural open spaces.” The vision further states that “Life in the Santa Clarita Valley will continue to be exciting, enjoyable, and rewarding through a broad range of housing types, an increase in quality jobs in close proximity to all neighborhoods, and transit-oriented villages complemented by excellent schools, attractive parks and other recreational amenities, expanded trail networks, and preserved natural resource areas.” The guiding principles set forth in the General Plan specifically provide for environmental protection in the Santa Clarita Valley. The guiding principles pertaining to environmental protection include planning growth within or on the periphery of previously developed areas; siting multi-family housing and mixed- use projects adjacent to transit corridors, stations, and key activity centers, such as the Valencia Town Center and portions of Newhall and Soledad Canyon Road; preserving the natural buffer area surrounding the Santa Clarita Valley; preserving the Santa Clara River as open space; and designing new development to improve energy efficiency.
The proposed project would be consistent with these goals. The project would establish a mixed-use housing development along a transit corridor (Soledad Canyon Road) within a previously disturbed parcel that is generally surrounded by developed land uses.
The project site has a zoning designation of MXC. The MXC zone is intended for commercial and residential uses that would provide opportunities for local residents to live and work. In this context, and as set forth in the General Plan, this definition of commercial includes uses such as light manufacturing and public services. Residences in the mixed-use corridors must be protected from high-use arterial streets. Multiple family dwellings shall have a minimum density of 11 dwelling units and a maximum density of 30 dwelling units per acre. Commercial uses are to have a maximum FAR 3 of 1.0.
The project includes a mixed-used housing development and, therefore, would be consistent with the MXC zone’s allowable land uses. Further, the project would conform to the zone’s density and FAR requirements, as the project would have a density of eight dwelling units per acre and a FAR below the prescribed maximum. Given the project’s consistency with the overall vision and development standards described in the General Plan, the project would not conflict with the City’s General Plan, and impacts would be less than significant.
City of Santa Clarita Zoning Ordinance
The project is zoned as MXC. As provided for by the Santa Clarita Zoning Ordinance, the MXC zones are used for mixed-use development in specific commercial corridors. An intent of the zone is to revitalize underused parcels and older buildings. The corridors can be either horizontal or vertical but must include residences protected from the impacts caused by high-volume arterial roads.
Conclusion
The project would not result in a significant adverse environmental impact related to land use and planning; no mitigation measures are necessary.
3 FAR calculated as total building floor area (in gross square feet [gsf]) divided by the total lot area (in gross square feet).
Total building floor area is 126,790gsf. Total lot area is approximately 1,533,312 gsf.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 69 XII. Mineral Resources
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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?
☐ ☐ ☐ ☒
Environmental Evaluation
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. The Surface Mining and Reclamation Act of 1975 regulates all mining activities in California and requires that significant mineral resources be protected from encroachment by incompatible development, as they provide a needed resource to support the construction of new homes, businesses, and roads. An area classified by the presence or absence of significant mineral deposits is known as a Mineral Resource Zone (MRZ).
According to the City’s General Plan Conservation and Open Space Element, Exhibit Co-2, Mineral Resources, the project site is not within MRZ-2 and does not have mineral deposits on-site. In addition, according to mapping by the California Geological Survey (2021), the project site is within MRZ-3, which is considered “areas containing known or inferred Portland cement concrete aggregate resource of undetermined mineral resource significance.” The California Geologic Energy Management Division’s Well Finder map (2019) shows no oil wells present within the project site. No known mineral resources that would be of value to the region and residents of the state would be lost. Therefore, no impact would occur, and no mitigation measures are necessary.
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. The City’s interactive map shows that the project site is not within any mineral or oil conservation overlay zones. The nearest zone is 1.5 miles southeast of the project site. As a result, the proposed project would not result in any loss of availability of a locally important mineral resource recovery site delineated on a general plan, specific plan, or other land use plan. Thus, no impact would occur, and no mitigation measures are necessary.
Conclusion
The project would not result in a significant adverse impact to mineral resources; no mitigation measures are necessary.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 70 XIII. Noise
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
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 2 miles of a public airport or public use airport, would the project expose people residing or working in the project site to excessive noise levels?
☐ ☐ ☐ ☒
The information provided in this section is based on the Environmental Noise and Vibration Assessment for Riverview Development prepared by Dudek, dated March 2023 (Dudek 2023b) and the Noise Technical Memorandum prepared by Dudek, dated June 19, 2024 (Dudek 2024e). These reports are provided as Appendix I: Noise and Vibration Assessment.
Setting
The project site is in the city of Santa Clarita and is therefore subject to the noise requirements outlined in the City of Santa Clarita General Plan Noise Element and the City of Santa Clarita Municipal Code (Dudek 2023b). The Noise Element identifies noise-generating uses and activities within city limits, the most dominant of which include major freeways and highways such as I-5, SR-14, and Sierra Highway; arterial streets; railroads; and attractions including Magic Mountain and the former Saugus Speedway (which currently is used for swap meets and special events, and is the location of the proposed project). The City’s Noise Element also identifies future growth and development within the city limits as a major contributor to future noise increases.
Given the nature of the area surrounding the project site, existing ambient noise levels are expected to be in the range of 60 to 65 A-weighted decibels (dBA) day-night average sound level (Ldn)/Community Noise Equivalent Level (CNEL) (Dudek 2023b). The primary noise source in the project vicinity is local and distant traffic noise.
Noise-sensitive receptors near the project site are relatively limited. The nearest noise-sensitive land uses is a family counseling center, Action Family Rehab, located approximately 65 feet west of the project site. The nearest residences to the project site are in the River Village neighborhood off Millhouse Drive and off Craftsman Court, approximately 1,150 feet to the northeast and separated from the project site by the Santa Clara River. Other, non-sensitive land uses in the project vicinity include commercial uses to the west and the Metrolink Station to the east.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 71 Environmental Evaluation
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?
Less than Significant Impact with Mitigation Incorporated. The noise analysis for the project, contained in its entirety in Appendix I, considers potential noise impacts associated with the project based on desktop resources and on data obtained during on-site pre-project outdoor ambient sound level monitoring. Noise impacts that could be caused by the project include those attributable to on-site construction, off-site construction (construction vehicle traffic), and project operation. As described in the following analyses, potentially significant impacts requiring mitigation would occur during project construction, specifically related to construction activities associated with the light manufacturing land use. All other noise impacts would be less than significant.
On-site Construction Activities
Construction noise levels usually vary from hour-to-hour and day-to-day, depending on the equipment in use, the operations being performed, and the distance between the source and receptor. Equipment that would be used during construction would include, graders, backhoes, concrete saws, rubber-tired dozers, loaders, cranes, forklifts, cement mixers, pavers, rollers, and air compressors. The typical maximum noise levels for various pieces of construction equipment at a distance of 50 feet are provided as Table 4 in Environmental Noise and Vibration Assessment for Riverview Development (Dudek 2023b), contained in Appendix I.
The noise assessment, guidance and methodologies from the Federal Transit Administration’s (FTA’s) Transit Noise and Vibration Impact Assessment Manual (FTA 2018) pertaining to construction noise and vibration are used in this analysis. FTA’s guidance provides evaluation criteria that construction noise should be 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 Leq 8-hour FTA guidance threshold for quantitative construction noise impact assessment.
Short-term, construction-related noise effects were assessed with respect to nearby noise-sensitive receptors. These include the nearest existing residential areas and the Action Family Rehab center, 4 which is next to the project site to the northwest. The potential exposure to the noise-sensitive receptors has been calculated (accounting for intervening topography, barriers, distance, etc.) using the Federal Highway Administration (FHWA) Roadway Construction Noise Model emulator. The emulator was used to evaluate construction noise in two ways: 1) “nearest distance” representing the closest distances (ranging from 65 feet to 1,315 feet) from the noise-sensitive receptors to each construction phase area on the project site, and 2) the “centroid distance” represents the distances (ranging from 370 feet to 2,050 feet) from the noise-sensitive receptors to the geographic center of each studied construction phase area on the project site. Predicted construction noise exposure levels at these studied offsite noise-sensitive receptors are then compared with the FTA guidance threshold of 80 dBA Leq (8-hour) for the exterior of residential land uses, which would be applicable only during daytime hours as defined by Santa Maria Clarita Municipal Code 11.44.020 and when construction activity is permitted by the City per Santa
4 Although the Action Family Rehab facility is on lands designated for commercial use, patients at the rehab center may stay overnight and, thus, create conditions that emulate those of a residential-type receiver. For this reason, the FTA guidance limit of 80 dBA for construction noise is applied to both the Action Family Rehab facility and the nearest existing offsite residential community.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 72 Maria Clarita Municipal Code 11.44.080. Detailed information regarding methodologies used to estimate construction noise levels for the project is provided in Appendix I.
Using the Roadway Construction Noise Model-emulating Excel workbook (provided in Appendix I), the predicted noise level exposures from the proposed concurrent construction activities at the nearest distances to the existing residential community range from 56 dBA to 62 dBA 8-hour Leq and are thus quieter than the FTA guidance limit of 80 dBA 8-hour Leq during daytime hours. Offsite construction noise exposures at this noise-sensitive receptor as calculated from sound sources at the project construction site centroid range from 52 dBA to 59 dBA 8-hour Leq and are also thus quieter than the FTA guidance-based noise limit. These predicted construction noise exposure levels are also less than the magnitude of the sampled daytime sound level of 63.8 dBA Leq and would thus be considered comparable to the pre-project outdoor ambient sound environment. They are also coincidentally less than the City’s 65 dBA exterior noise limit per Section 11.44.040 that applies to project operation (post- construction). Based on these findings, construction noise exposures at these existing residences are considered less than significant impacts.
At the neighboring Action Family Rehab, aggregate noise levels from concurrent phases of construction activity may exceed 80 dBA when the active construction equipment is at their closest distances. These predicted exceedances are no more than 3 decibels and only expected for at most ten months of the five- year project construction schedule when the Lot 5 light manufacturing portion of the project is under construction. However, these exceedances would be a potentially significant impact requiring noise abatement. Noise control and sound abatement measures shall be required during construction of the light manufacturing portion of the project, as described in MM NOISE-1. With implementation of MM NOISE-1 (Noise Abatement during Construction of Light Manufacturing Lot), construction-related noise impacts would be less than significant with mitigation incorporated.
Off-site Construction Activities
The project would result in local, short-term increases in roadway noise because of construction traffic.
Project-related traffic would include workers commuting to and from the project site as well as vendor and haul trucks bringing or removing materials. Based upon the fundamentals of acoustics, a doubling (i.e., a 100% increase) would be needed to result in a 3-dB increase in noise levels, which is the level corresponding to an audible change to the typical human listener. A maximum of 100 workers per day is anticipated during the construction phase; this would not create a significant increase in traffic noise as Soledad Canyon Road experiences approximately 3,771 vehicles per hour at peak flow.
Therefore, traffic related to construction activities would not result in 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. Impacts from project-related construction traffic noise would be less than significant.
Operation
Long-term operational noise associated with the project includes on-site operational noise from residential mechanical equipment, parking lot activity, and activity related to the light manufacturing land use.
Project-generated traffic noise off-site is also considered long-term operational noise. Each operational noise source is addressed below.
The proposed project would result in the creation of additional vehicle trips on local roadways in the vicinity of the project (i.e., North California Street and East Harding Way), which could result in increased traffic noise levels at noise-sensitive land uses adjacent to area roadways. Actual traffic noise exposure levels at noise-sensitive receptors in the project vicinity would vary depending on a combination Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 73 of factors such as variations in daily traffic volumes, vehicle types, relative distances between sources and receiver locations, shielding provided by existing and proposed structures, and meteorological conditions.
Refer to Appendix I for modeling inputs and results. Soledad Canyon Road experiences approximately 3,771 vehicles per hour at peak flow, the project is expected to create approximately 257 trips during the morning peak flow (167 trips associated with residential, and 87 trips associated with the manufacturing uses), and 307 trips in the afternoon peak hour (214 trips associated with residential, and 93 trips associated with the manufacturing uses).
Mechanical equipment associated with the long-term operation of various uses which include conditioned spaces generally can include heating, ventilation, and air conditioning (HVAC) equipment, backup generators, and various fans, pumps, and compressors that can be significant noise sources. HVAC equipment serving commercial spaces is often mounted on rooftops, partially enclosed at-grade adjacent to buildings, or located within enclosed mechanical equipment rooms, with residential HVAC outdoor equipment located at-grade. Noise levels generated by the HVAC and other mechanical equipment vary significantly depending on unit size, efficiency, location, type of rotating or reciprocating components, and orientation of openings. HVAC associated the manufacturing building would generate a noise exposure of 98.1 dBa during peak operations. During off-peak periods, the HVAC systems would operate under reduced loads and cycle times, reducing generated noise levels commensurately. Sound exposure levels at the nearest offsite sensitive receptor (Action Family Rehab) are expected to be below 55 dBA (see Appendix I for more detail). Further, sound exposure levels at the nearest residential uses are expected to be well below 35 dBA. Therefore, the HVAC noise levels modeled for the proposed project are anticipated to comply with the City of Santa Clarita non-transportation noise level thresholds.
Development of the proposed project is not predicted to result in exposure of existing noise-sensitive receptors to absolute noise levels exceeding the City’s 60 dBA Ldn land use compatibility thresholds or result in relative increases in the ambient noise environment of 3 dB or more. Therefore, impacts from traffic noise levels associated with the proposed project would be less than significant. b) Would the project result in generation of excessive groundborne vibration or groundborne noise levels?
Less than Significant Impact. Construction activities on the project site may result in varying degrees of temporary ground vibration, depending on the specific construction equipment used and operations involved. For the potential for continuous/frequent intermittent vibration to result in damage to structures, Caltrans indicates a threshold of 0.5 inch per second (in/sec) peak particle velocity (PPV) for “new residential construction” (Caltrans 2020), such as the types of structures in the proposed project vicinity.
Representative groundborne vibration levels for various types of construction equipment that may be associated with the proposed project are summarized in Appendix I at a reference distance of 25 feet (FTA 2018).
Groundborne vibration attenuates rapidly, even over short distances, with vibration levels varying depending on soil conditions, construction methods, and the equipment used. The attenuation of groundborne vibration as it propagates from source to receptor through intervening soils and rock strata can be estimated with expressions found in FTA and Caltrans guidance. Based on the 25-foot reference levels, construction vibration levels were calculated using standard Caltrans and FTA equations at a distance of 65 feet to the west, to represent the closest existing structure to the project site, the Action Family Rehab. The maximum PPV generated by construction activities at 65 feet would be 0.021 in/sec PPV, which would be far below the established damage criteria 0.5 in/sec PPV; therefore, construction vibrational impacts would be less than significant.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 74 The proposed project does not incorporate any project elements that would generate substantial groundborne noise and vibration levels at nearby sensitive receptors during its long-term operation.
Therefore, this impact would be less than significant.
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 2 miles of a public airport or public use airport, would the project expose people residing or working in the project site to excessive noise levels?
No Impact. There are no private airstrips in the project vicinity. The nearest airport is Whiteman Airport, located approximately 13 miles southeast of the project site. The project site is not within 2 miles of any public airport, nor is it located within the boundaries of any airport land use plans. Therefore, the project would not expose or result in excessive noise for people residing or working in the project site. No impact would occur.
Conclusion
With implementation of MM NOISE-1, noise impacts would be less than significant.
Mitigation Measures
MM NOISE-1 Noise Abatement during Construction of Light Manufacturing Lot. The following noise control and/or sound abatement measures shall be implemented during construction of Lot 5, which is the lot that is planned for the light manufacturing land use:
A. Site Preparation:
1. To the extent practicable, earthwork on the east side of the existing hill on Lot 5 shall start as far east and possible and proceed in an east-to-west direction to take advantage of the distance between the site preparation activity and the Action Family Rehab facility and the sound-blocking effects of the unworked terrain that should naturally occlude line-of-sight between this construction process and this noise-sensitive land use to the northwest.
Consistent with acoustical principles for noise reduction afforded by such natural features, this line-of-sight occlusion should yield the needed decibel reduction at this receptor and result in 8-hour Leq exposure levels that are compatible with FTA guidance (80 dBA).
2. Should line-of-sight occlusion not be feasible per A.1 above, then along or within the property line where the project site adjoins the Action Rehab facility, a 20-foot-tall temporary barrier shall be installed made of typical outdoor-appropriate plywood sheeting, acoustical sound blankets, or other materials (having sound transmission class [STC] 20 or better) to ensure line- of-sight occlusion between operating project construction equipment and the Action Family Rehab land use.
B. Grading and Paving: An appropriate temporary barrier shall also be constructed prior to the grading and paving phases and shall remain in place until these phases of the construction are completed. The grading and phasing barrier shall be at least a 12- foot-tall temporary barrier made of typical outdoor-appropriate plywood sheeting, acoustical sound blankets, or other materials (having sound transmission class [STC] 20 or better) along or adjacent to the property line where the project site adjoins the Action Family Rehab facility,
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 75 XIV. Population and Housing
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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?
☐ ☐ ☐ ☒
Setting
The project site is located on undeveloped land that does not contain residential uses and people do not currently reside on-site. The project site has a land use designation of MXC and is located within the City’s JCOZ, which is intended to encourage future development that supports employment growth within the city.
The SCAG 2020-2045 RTP/SCS forecasts for population, household, and employment growth. Table 9 provides a summary of the anticipated changes in these characteristics from 2016 to 2045 for the city of Santa Clarita.
Table 9. Population and Employment Growth Forecast for the City of Santa Clarita Year Population Households Employment
2016 218,200 71,800 91,200
2045 258,800 95,200 105,200
Net Change 40,600 23,400 14,000
Source: SCAG (2020b)
Environmental Evaluation
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)? Less than Significant Impact. Construction of the project would result in temporary employment increases. Employment increases have the potential to cause population growth, as they may draw additional people and their households to the city. However, given the relatively common nature of the project (i.e., does not involve highly specialized construction skills), construction personnel would likely be sourced from the local region, and the project would not require the relocation of construction personnel.
The proposed project would result in development of the subject property mixed use development that would add employment opportunities to the area. It is anticipated that the employment base the construction phase of the project would come from the existing population in the city of Santa Clarita.
According to the Bureau of Labor Statistics (EDD 2023), the City of Santa Clarita civilian labor force contains approximately 111,000 persons with approximately 106,200 people employed and an Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 76 unemployment rate of approximately 4.3% (approximately 4,800 persons). Accordingly, the project region already contains an ample supply of potential employees under existing conditions and the project’s labor demand is not expected to draw substantial numbers of new residents to the area.
Furthermore, approximately 75% of City of Santa Clarita residents commute outside of the city for work (SCAG 2019:21); therefore, the project would provide job opportunities closer to home for existing and future Santa Clarita residents.
With regard to direct population growth, the nature of the project is the development of 318 single-family units. The project site is identified as a Suitable Site (Housing Site 23) in the Housing Element of the General Plan. A Suitable Site is a site that may be feasibly developed for housing to meet the Regional Housing Needs Allocation (RHNA). The project site is suitable for very low– and low-income units.
As addressed above, the expected population growth of the city of Santa Clarita is approximately 40,000 by 2045. With the creation of 318 additional single-family units, it can be estimated that with four individuals per unit, the population growth as a result of the project would be 1,272 individuals. The addition of 1,272 residents would account for approximately 3% of the city’s expected population growth.
With the preferred zoning for residential development, and designation as a Suitable Site for the RHNA, population growth as a result of the project is anticipated and impacts would be less than significant.
The project site would be served by existing transportation and utility infrastructure and these connections would support the proposed project only. Therefore, the project would not result in the extension of infrastructure or roads such that additional, unplanned growth would be facilitated. b) Would the project displace substantial numbers of existing people or housing, necessitating the construction of replacement housing elsewhere? No Impact. The project site does not currently contain any residential structures and no people live on the site under existing conditions. Accordingly, implementation of the project would not displace substantial numbers or existing housing or people and would not necessitate the construction of replacement housing elsewhere. No impact would occur.
Conclusion
Based on the analysis above, the project would not result in significant environmental impacts related to population and housing; no mitigation measures are necessary.
XV. Public Services
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
Would the project:
(a) 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? ☐ ☐ ☒ ☐
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 77 Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
Schools? ☐ ☐ ☒ ☐
Parks? ☐ ☐ ☒ ☐
Other public facilities? ☐ ☐ ☒ ☐
Setting
Fire protection services for project site are provided by the Los Angeles County Fire Department (LACFD), with the nearest fire station being LACFD Station 111, located at 26829 Seco Canyon Road, Valencia, California, approximately 1.5 miles, by road, from the project site. The Los Angeles County Sheriff Department provides police protection services to the project site and is housed at the Santa Clarita Valley Station, located at 26201 Golden Valley Road in Santa Clarita, which is approximately 1.4 2.5 miles (distance by road travel), to the east and south. The project site is located within the William S. Hart Union High School District and Saugus Union School District, with nearest school to the project site being Bowman High School located 0.75 mile east of the project site. The nearest park, Duane R Harte Park, is located approximately 0.25 mile northeast of the project site, and Central Park is located approximately 0.75 mile northeast. The nearest library to the project site is the Valencia Public Library located at 23743 West Valencia Boulevard, approximately 1.15 miles west of the project site.
Environmental Evaluation
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?
Less than Significant Impact. The LACFD serves as a urban and wildland fire protection agency.
CAL FIRE has designated the LACFD as a wildland firefighting unit. The nearest fire station is Station 111, located at 26829 Seco Canyon Road, Valencia, California, approximately 1.5 miles, by road, from the project site. There are approximately 11 fire stations within a 5-mile radius of the project site (LACFD 2023). Additional fire protection could be provided by other fire stations in Santa Clarita, including Station 126 (Battalion 6 Headquarters), located at 26329 Citrus Street, approximately 1.3 miles west of the project site. Based on the project site’s proximity to the two existing fire stations, the project would be adequately served by fire protection services, and no new or expanded unplanned facilities would be required.
Additionally, the project would be subject to current LACFD requirements for sprinkler systems, fire alarm systems, and equipment and firefighter access. LACFD stations would provide a sufficient level of fire protection service to the project site, and this level of service would not be adversely affected by the project. California law (PRC 4291) requires a minimum defensible space of 100 feet around residential homes, which must consist of the 0 to 30-foot firebreak that requires removal of flammable vegetation and the 30- to 70-foot reduced fuel zone (or to the property line, whichever is nearer to the structure).
Per Section 21.03.060, California Model Water Efficient Landscape Ordinance, of the City’s Zoning Ordinance, the homes would also be subject to the City’s requirements for defensible space, proper fire- Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 78 safe plant and tree selection, sufficient irrigation, and design features to control erosion and drainage.
Compliance with requirements for fire prevention, fire flow, emergency access, and protection from wildland fire hazards would reduce the likelihood of a fire emergency at the project site, thereby reducing potential demand for fire services.
Due to the availability of fire services within proximity to the project site, and required compliance with fire code standards, the construction or expansion of existing fire facilities is not expected to be required as a result of the project. Therefore, substantial adverse physical impacts associated with the provision of new or physically altered facilities would not occur. Impacts would be less than significant, and no mitigation measures are necessary.
Police protection?
Less than Significant Impact. The Los Angeles County Sheriff Department provides police protection in the vicinity of the project site. The Santa Clarita Sheriff’s Station, located at 26201 Golden Valley Road is approximately 2.5 1.4 miles (distance by road travel) east and south of the project site.
The project would add approximately 1,272 residents to the City’s population and could place increased demand on police protection services. However, the project would not result in the construction or expansion of police facilities, as the current staffing and facilities are expected to be sufficient to serve the project. Therefore, the project would not result in substantial adverse physical impacts associated with the provision of new or physically altered police facilities. As such, impacts would be less than significant, and no mitigation measures are necessary.
Schools?
Less than Significant Impact. Implementation of the project would create a direct demand for public school services, as the project site would create 318 new single-family residences. According to the California School Board, the average number of students generated per dwelling unit is 0.7 students (California Department of General Services, Office of Public School Construction 2009). Therefore, the proposed project could result in approximately 222 new students.
The proposed project would be served by the William S. Hart Union High School District, which provides junior high and high school education, and the Saugus Union School District, which provides elementary school education. Students from the residences at the project would attend Emblem Academy Elementary School, located at 22635 Espuella Drive in Saugus, California, approximately .08 mile north of the project site. Middle school–aged children would attend La Mesa Junior High School, located at 26623 May Way, Santa Clarita, approximately 2.5 miles east of the project site. High school–aged students would attend Golden Valley High School, located at 27051 Robert C. Lee Parkway in Santa Clarita, approximately 2.1 miles southeast of the project site.
The Applicant would be required to contribute development impact fees to the William S. Hart Union High School District and Saugus Union School District in compliance with SB 50, which allows school districts to collect fees from new developments to offset the costs associated with increasing school capacity needs. Mandatory payment of school fees would be required prior to the issuance of building permits. Additionally, as addressed previously, the expected population growth of the city of Santa Clarita is approximately 40,000 by 2045. With the creation of 318 additional single-family units, the addition of 1,272 residents would account for approximately 3% of the city’s expected population growth. On average, a 3% increase to each public school attendance does not put an unexpected burden on education facilities and impacts to public schools would therefore be less than significant.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 79 Parks?
Less than Significant Impact. As discussed previously, the project would be located in the vicinity of numerous parks and open space. Central Park and Duane R Harte Park are located to the north across the Santa Clara River, and the Quigley Canyon Open Space, covering nearly 160 acres with equestrian ranches and trails, is approximately 2 miles to the southeast. The project design includes open space for the residents, including a pool facility (see Section XVI Recreation, below). Due to the access to ample public parks and recreation opportunities, the existing park facilities would be able to accommodate the increase in new residents introduced by the proposed project. Thus, impacts would be less than significant.
Other public facilities?
Less than Significant Impact. Other public facilities and services provided within the city include library services and City administrative services. Library services are provided by the Valencia Public Library located at 23743 West Valencia Boulevard, approximately 1.15 miles west of the project site.
The population increase expected to result from the proposed project represents approximately 0.3% of the expected population growth of the City of Santa Clarita by 2045. This would result in a negligible increase in the service population for the Valencia Public Library and City administration. This minor increase in population is not anticipated to result in the need for additional library facilities or City administrative facilities. The proposed project would not require expansion of existing library, City administration, or other public service facilities or construction of new facilities. Therefore, impacts to other public facilities would be less than significant.
Conclusion
In summary, and based on the analyses presented earlier in this section, the project would not result in a significant adverse environmental impact related to public services; no mitigation measures are necessary.
XVI. Recreation
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
Would the project:
(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?
☐ ☐ ☒ ☐
(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?
☐ ☐ ☒ ☐
Environmental Evaluation
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?
Less than Significant Impact. The proposed project includes the development of recreational uses for the residential properties within the project parcel. Recreational facilities of the new residential properties Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 80 would include a large neighborhood park and an aquatic center. With the development of the proposed recreational facilities, surrounding neighborhood and regional recreational facilities would not likely see a substantial increase in use. Therefore, the impacts to surrounding recreational facilities would be less than significant.
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?
Less than Significant Impact. The proposed project includes an aquatic center and recreational park.
However, the construction of these facilities would be beneficial to the wellbeing of residents and their inclusion in design does not create unique or additional adverse effects on the environment. Therefore, environmental effects related to the construction or expansion of recreational facilities would be less than significant.
Conclusion
The project would not result in a significant adverse environmental impact related to recreation; no mitigation measures are necessary.
XVII. Transportation
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
Would the project:
(a) Conflict with a program plan, ordinance, or policy
addressing the circulation system, including transit,
roadway, bicycle, and pedestrian facilities?
☐ ☐ ☒ ☐
(b) Would the project conflict or be inconsistent with State 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? ☐ ☐ ☐ ☒
The information in this section is based on Transportation Assessment for the Riverview Mixed-Use Development Project, Santa Clarita, California, dated August 2023, and the EIR Supplemental Transportation Analysis for the Revised River Mixed-Use Project, Santa Clarita, California, dated February 2024, prepared for the project by Gibson Transportation Consulting, these documents are provided as Appendix J: Transportation Assessment (Gibson Transportation Consulting, Inc. 2023; (Gibson Transportation Consulting, Inc. 2024).
Setting
The project site is located along the southern border of Soledad Canyon Road, approximately 0.5 mile to the east of the intersection with Bouquet Canyon Road. According to the City of Santa Clarita General Plan Circulation Element, the segment of Soledad Canyon Road next to the project site has a roadway classification defined as Major Highway (City of Santa Clarita 2011b). Soledad Canyon Road provides four to six travel lanes (two to three in each direction) with additional left-turn lanes. On-street parking is generally not provided within the project site. Major highways can accommodate approximately Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 81 54,000 vehicles per day (City of Santa Clarita 2011b). Street sections may include striped, on-street bike lanes, or separated bike paths.
Chuck Pontius Commuter Rail Trail is a bike path north of the project site running in the east-west direction, parallel to Soledad Canyon Road. Farther north, the Santa Clara River Trail is a Class I bike path north of the Santa Clara River that generally runs parallel to Soledad Canyon Road within the vicinity of the project site. Pedestrian access to the project site would be provided via proposed sidewalks along Soledad Canyon Road.
There are bus stops along Newhall Ranch Road, Commuter Way, Soledad Canyon Road, Bouquet Canyon, and at the Santa Clarita Metrolink Station, served by Santa Clarita Transit Routes 4, 5, 6, 12, 14, 501, 502, 796, 797, and 799, Kern Transit Service Route 130, and Metrolink Rail Green Antelope Valley Line. Santa Clarita Metrolink Station is located adjacent to project site on Soledad Canyon Road.
Background and Analysis Methodology
SB 743, which was codified in PRC Section 21099, was signed by the Governor in 2013 and directed the OPR to identify alternative metrics for evaluating transportation impacts under CEQA. Pursuant to Section 21099, the criteria for determining the significance of transportation impacts must “promote the reduction of greenhouse gas emissions, the development of multimodal transportation networks, and a diversity of land uses.” Recently adopted changes to the State CEQA Guidelines in response to Section 21099 include a new section (Section 15064.3) that specifies that vehicle miles traveled (VMT) is the most appropriate measure of transportation impacts. The primary purpose of SB 743 is eliminating LOS as a measure of vehicular capacity and traffic congestion as a basis for determining significant transportation impacts under CEQA. Rather, SB 743 requires lead agencies to shift the focus from evaluating traffic impacts based on metrics that only consider vehicle travel time and delay (i.e., impacts to drivers) to metrics that capture the State’s goals of improved air quality, reduced GHG emissions, and improved public health (i.e., impacts of driving). In response to SB 743, the OPR selected VMT as the new transportation impact metric for which lead agencies are required to define methodologies, thresholds, and mitigation measures consistent with their respective General Plan goals. A separate Technical Advisory issued by OPR provides additional technical details on calculating VMT and assessing transportation impacts for various types of projects.
The City of Santa Clarita prepared and adopted the Transportation Analysis Updates in Santa Clarita in June 2020 to address changes to CEQA pursuant to SB 743 to include VMT analysis methodology, screening tools, and VMT thresholds (City of Santa Clarita 2020b).
Environmental Evaluation
a) Would the project conflict with a program plan, ordinance, or policy addressing the circulation system, including transit, roadway, bicycle, and pedestrian facilities? Less than Significant Impact. The project proposes to construct a mixed-use housing and commercial development on a currently underutilized parcel along Soledad Canyon Road, which is classified as a Major Highway in the City’s General Plan Circulation Element (City of Santa Clarita 2011b). As shown in Appendix J and below, the project does not conflict with the following applicable plans.
Circulation Element of the General Plan
The Circulation Element plans for the continued development of transportation systems that are consistent with regional plans, local needs, and the community’s character. The Circulation Element identifies and promotes a variety of techniques for improving mobility including the development of alternative travel Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 82 modes and support facilities; increased efficiency and capacity of existing systems through management strategies; and coordination of land use planning with transportation planning by promoting concentrated, mixed-use development near transit facilities. The project is consistent with the applicable objectives of the Circulation Element and would help to improve the vehicular and bicycle network, provide end-of-trip facilities, encourage alternative travel modes, and support electric vehicles.
Non-Motorized Transportation Plan
The Non-Motorized Transportation Plan guides future pedestrian and bicycle infrastructure, policy, and planning in the city. The project would promote walking and biking to and from home and work and support bicycling through the provision of bike parking facilities throughout the project site. Further, the project would provide a pedestrian-friendly design and facilitate transit use by developing residential and employment opportunities immediately adjacent to the Santa Clarita Metrolink Station.
Specific Plans
The project site is not within an area currently governed by a Specific Plan. However, the project site is located within the Saugus Speedway JCOZ. The Santa Clarita Unified Development Code states, “The purpose of the JCOZ is to support the General Plan objective of promoting the creation of strong regional and local economies via the implementation of strategic land use planning policies.” The development would support the local economy with employment and housing opportunities and would strategically locate them next to transit. Thus, the project would support the goals of the JCOZ.
Santa Clarita Unified Development Code (SCUDC) Title 17 Division 5 (Use Classifications and Required Parking)
The project would provide residential parking in accordance with the SCUDC. The project would provide parking consistent with other similar uses in Southern California as shown in Appendix J. The project’s provision of approximately 983 1,038 spaces for project uses would meet the requirements of the SCUDC.
2016 California Green Building Standards Code (CALGreen) Sections 5.106.4.1.1 and 5.106.4.1.2 (Bicycle Parking)
CALGreen Sections 5.106.4.1.1 and 5.106.4.1.2 detail the bicycle parking requirements for new developments. Based on its parking supply of approximately 983 1,038 vehicular parking spaces, per CALGreen’s requirement for the provision of bicycle parking at a rate of at least 5% of vehicular spaces, the project would be required to provide 50 bicycle parking spaces. The project would meet or exceed the CALGreen requirements for on-site bicycle parking supply.
Streetscape Plans
There are no streetscape plans near the project site; therefore, streetscape plans do not apply to the project. However, the project design is intended to promote a balanced approach to all modes of transportation and provide safe and adequate space for sidewalks, bicycle paths, transit, parking, vehicular traffic, street trees, landscaping, lighting, and street furnishings, consistent with the goals of nearby streetscape plans.
Community Character and Design Guidelines
City of Santa Clarita Community Character and Design Guidelines (RRM Design Group, March 24, 2009) (Design Guidelines) identifies urban design principles to guide architects and developers in designing high-quality projects that meet the City’s functional, aesthetic, and policy objectives and help Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 83 foster a sense of community. The Design Guidelines are organized around four design goals: Sense of Timelessness, Sense of Ownership, Sense of Place and Identity, and Sense of Community. The project meets the objectives and goals set in the Design Guidelines and is therefore consistent with all applicable policies.
The project is consistent with each of the City documents discussed above. Therefore, impacts to applicable plans and policies would be less than significant and no mitigation measures are necessary. b) Would the project conflict or be inconsistent with State CEQA Guidelines Section 15064.3, subdivision (b)?
Less than Significant Impact. As previously discussed, SB 743, approved in 2013, was intended to change the way transportation impacts are determined according to CEQA. Updates to the State CEQA Guidelines that were adopted in December 2018 included the addition of State CEQA Guidelines Section 15064.3, of which subdivision “b” establishes criteria for evaluating a project’s transportation impacts based on project type and using automobile VMT as the metric. As a component of the OPR’s revisions to the State CEQA Guidelines, lead agencies were required to adopt VMT thresholds of significance by July 1, 2020. In 2020, the City of Santa Clarita adopted guidelines for transportation in their Transportation Analysis Updates in Santa Clarita, which is used in this analysis to determine the significance of project-related VMT.
The first step of a VMT study is to determine what type of analysis, if any, is needed. Based on the OPR Technical Advisory, the City of Santa Clarita adopted four screening criteria that the City may use to identify if a proposed project is expected to cause a less-than-significant impact without conducting a detailed study:
• The project is located in a Transit Priority Area, defined as being within 0.5 mile of an existing or planned major transit stop or an existing stop along a high-quality transit corridor • The project has a FAR of more than 0.75
• The project does not contain more parking for use by residents, customers, or employees than required by the City
• The project is consistent with the 2020-2045 RTP/SCS (SCAG 2020a), the regional plan to reach State air quality and GHG reduction targets
• The project does not replace affordable residential units with a smaller number of moderate- or high-income residential units
The project, due to its location immediately adjacent to the Santa Clarita Metrolink Station, was evaluated under the accessibility to transit screening criteria. As outlined in Appendix J, the project meets all screening criteria related to transit proximity. As such, the project can be presumed to have a less than significant VMT impact and no further VMT analysis is needed. 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)?
Less than Significant Impact. A significant impact may occur if a project includes new roadway design or introduces a new land use or features into an area with specific transportation requirements and characteristics that have not been previously experienced in that area, or if project site access or other features are designed in such a way that creates hazard conditions.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 84 The project site would provide vehicular access via four new access points, and one existing access point at Commuter Way and Soledad Canyon Road. A sufficient number of inbound and outbound lanes would be provided to avoid backups.
The project includes the provision of crosswalks across the new signalized intersection serving the project’s main gate driveway. These amenities would serve to reduce hazardous conflicts between vehicles and pedestrians.
The new driveways would be constructed to City of Santa Clarita design standards5 and would be similar to existing access routes for land uses in the project vicinity. Therefore, the project would not introduce any hazardous geometric design features that would create significant hazards to the surrounding roadways. Furthermore, the project site would be accessed by vehicles and trucks that normally travel on city streets and the project would not introduce any incompatible uses that would create significant hazards to the surrounding roadways. Therefore, project roadway improvements would not substantially increase hazards due to a design feature. Impacts would be less than significant, and no mitigation measures are necessary.
d) Would the project result in inadequate emergency access? No Impact. A significant impact may occur if the project design would not provide emergency access that meets the requirements of the Los Angeles County Sheriff Department or the LACFD, or threatened the ability of emergency vehicles to access and serve the project site or adjacent uses. Vehicular access to the project site would be provided via four new access points, one of which would provide emergency access only, and one existing access point at Commuter Way and Soledad Canyon Road. These driveways would be constructed to City of Santa Clarita design standards, which would allow for access of emergency vehicles. Therefore, there would be no impact related to emergency access, and no mitigation measures are necessary.
Conclusion
The project would not result in a significant adverse transportation impact; no mitigation measures are necessary.
XVIII. Tribal Cultural Resources
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
(a) Would the project cause a substantial adverse change in the significance of a tribal cultural resource, defined in PRC 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:
(i) Listed or eligible for listing in the California
Register of Historical Resources, or in a local
register of historical resources as defined in PRC
Section 5020.1(k), or
☐ ☒ ☐ ☐
5 Santa Clarita design standards are based on California Building Codes, City of Santa Clarita Amendments, City of Santa Clarita Municipal Code, and Local Design Criteria.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 85 Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
(ii) 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. In applying
the criteria set forth in subdivision (c) of PRC
Section 5024.1, the lead agency shall consider
the significance of the resource to a California
Native American tribe.
☐ ☒ ☐ ☐
The analysis for this section is based on confidential information provided during a search of the Sacred Lands File through the NAHC and tribal consultation with the City of Santa Clarita. Refer to Appendix C for a detailed discussion of the prehistoric and ethnographic settings for the region and applicable regulations pertaining to tribal cultural resources.
Setting
In a letter dated January 31, 2023, the NAHC indicated that their search of the Sacred Lands File returned positive results and that the Fernandeño Tataviam Band of Mission Indians (FTBMI) should be contacted to discuss the findings. As reported in the archaeological resources assessment report prepared for the project (see Appendix C), a CHRIS search was conducted on September 12–13, 2022 at the SCCIC.
No resources were found within the project site; within 1 mile of the project site, there have been five archaeological sites and six isolated resources with Native American components recorded, the closest of which is 469 feet (0.1 mile) to the project site. An archaeological survey of the project site did not identify any Native American archaeological resources that may also be a tribal cultural resource (Dudek 2024b). There are extensive parking areas, both paved and covered in manufactured gravel fill, resulting in highly variable ground surface visibility ranging from no visibility (0%) to fair visibility (30%) in these areas. The remaining portion of the project site included undeveloped rugged hills with sparse to dense vegetation. The ground surface visibility within this area was very good to excellent (60%–90%). After considering the geophysical setting, past historical developments, proximity to the Santa Clara River, and presence of Native American archaeological resources identified in the vicinity through the CHRIS search, the investigators concluded that there is moderate potential for a buried archaeological resource, including those that may be a tribal cultural resource.
Pursuant to PRC Section 21080.3.1(c), the NAHC’s response letter included a list of 18 contacts who represent tribes that are traditionally and culturally affiliated with the project site (Tribal Consultation List) and require written notification in compliance with PRC Sections 21080.3.1(d). The 18 individuals identified on the NAHC’s Tribal Consultation List include representatives from 14 tribal organizations whose cultural affiliations
6 include the following (in alphabetical order): Cahuilla, Chumash, Gabrielino, Kitanemuk, Luiseno, Tataviam, and Vanyume. The City mailed notification letters on March 10, 2023 to all of the tribal contacts.
The City received written responses to the notification letters from six tribes, one letter (to the Gabrielino- Tongva Tribe) was returned as undeliverable, and no responses were received to the remaining 11 notification letters. Responses were received from the following tribal organizations:
Barbareño/Ventureño Band of Mission Indians (BVBMI), FTBMI, Gabrieleño Band of Mission Indians –
6 There are variations in the preferred names and spellings of cultural affiliations and/or identities from those used by the NAHC to classify California Native American tribes. The cultural affiliations reported here are those given in the NAHC’s Tribal Consultation List, which includes some individual tribal organizations who report multiple cultural affiliations. Refer to the NAHC Tribal Consultation List for details on the preferred names and cultural affiliations that were given at the date of the letter.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 86 Kizh Nation (Kizh Nation), Gabrielino-Tongva Indians of California (GTIOC), Santa Ynez Band of Chumash Indians, and San Fernando Band of Mission Indians (SFBMI). BVBMI, Kizh Nation, and GTIOC responded by deferring to other groups without specifying an individual tribal organization.
On March 10, 2023, the City received a written response from the Santa Ynez Band of Chumash Indians and requested additional information (e.g., CHRIS records, cultural resource studies, or maps) to assist in their review. The reply was sent from Crystal Mendoza, an Administrative Assistant in the Cultural Resources department. In an email sent April 30, 2024, the City provided additional information on the project design and the latest draft of Dudek’s archaeological resources report (Dudek 2024b), which included the results of a CHRIS search and field survey, and contained multiple maps depicting various types of information considered in the study. On May 5, 2024, the City received a response via email and stated the information provided was received and would be reviewed. This was also confirmed in a follow-up phone call made the following week. As part of this correspondence, the City requested that any comments be submitted by May 31, 2024. The City sent regular emails and made follow-up phone calls to confirm the status of the review, the last of which was on June 3, 2024. To-date the City has Santa Ynez Band of Chumash Indians has not replied to the City’s request for input.
On March 10, 2023, the City received a written response from Donna Yocum, chairwoman for the SFBMI. In the response, Chairwoman Yocum attached a letter acknowledging that the project falls within their traditional tribal lands and is likely to have a tribal cultural resource. No specific resource was identified but as a means of protecting and preserving potential resources, SFBMI requested that a tribal representative be present during ground disturbing activities, and named a specific individual as a tribal partner who is qualified to act in the capacity of a Native American monitor. The letter also includes brief descriptions of SFBMI’s traditional lands and cultural heritage.
On March 13, 2023, the City received an email from Sarah Brunzell, Manager in the Cultural Resources Management Division of FTBMI’s Tribal Historic and Cultural Preservation Department. The message requested that the formal notification be submitted digitally through their intake process. This was completed by the City and verified on March 16, 2023. With the verification, Sarah Brunzell stated that the project could be susceptible to the highest sensitivity category due to its proximity to sensitive tribal cultural resources. Sarah Brunzell requested additional information, such as the cultural resources assessment or geological report. In an email sent April 30, 2024, the City provided additional information on the project design and results of the archaeological assessment published in the latest draft of Dudek’s report (Dudek 2024b). After reviewing the information, FTBMI requested to consult with the City on a conference call, which was held on May 9, 2024. During the consultation, the tribal representatives confirmed that the FTBMI’s records indicate the project is in or near to a tribal cultural resource and that due to the culturally sensitive status of the resource, more details about its nature and location must remain strictly confidential. To address the tribal cultural resources sensitivity, FTMBI proposed three measures to be included as mitigation, which includes the following provisions: full-time monitoring by an FTBMI representative; consultation with FTBMI if any tribal cultural resources are discovered; and a protocol to comply with existing regulations regarding the discovery of human remains.
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Draft Final Initial Study/Mitigated Negative Declaration 87 Environmental Evaluation
a) Would the project cause a substantial adverse change in the significance of a tribal cultural resource, defined in PRC 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-i) Listed or eligible for listing in the California Register of Historical Resources, or in a local register of historical resources as defined in PRC Section 5020.1(k)?
a-ii) 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. In applying the criteria set forth in subdivision (c) of PRC Section 5024.1, the lead agency shall consider the significance of the resource to a California Native American tribe.
Less than Significant with Mitigation Incorporated. Ground disturbance associated with the project includes significant grading and terracing of the hillside in the northwestern portion of the proposed project site and cut slopes at a gradient of 2:1 in the southern area. Significant fill grading within the area currently occupied by structures and paved tracks and parking lots would occur. This latter area is proposed for construction of residential and commercial development including 318 single-family dwelling units and a 126,790 square foot manufacturing building, recreational amenities, community open space, paved lots, and associated utility and landscaping installation. Given that the entire proposed project site elevation is currently between 1,190 and 1,290 amsl and the elevation after grading is proposed between approximately 1,196 and 1,209 amsl, the proposed grading and construction would require impacts to native soils within the northern portion of the site and along the southwestern boundary; however, much of the proposed construction within the central and eastern portions of the site would occur within fill soils only.
The NAHC’s SLF search returned positive results and recommended contacting FTBMI for additional information. During the City’s consultation with FTBMI, no specific resource was identified as being listed or eligible for the CRHR or listed in a local register. A search of the CHRIS was conducted on September 12–13, 2022, and did not identify any previously recorded archaeological sites or other type of resource that are affiliated with Native Americans in the project site. The CHRIS search also indicated that there have been five archaeological sites and six isolated discoveries affiliated with Native Americans recorded within a 1-mile radius of the project site, the closest of which is 469 feet (0.1 mile) away. An archaeological survey of the project site did not identify any archaeological resources. Based on these findings, there are no tribal cultural resources identified in the project site that can be confirmed as listed or eligible for the CRHR or identified on any registers maintained by the City.
The archaeological resources assessment concluded that there is moderate potential to encounter an as-yet unrecorded archaeological resource preserved below ground within the project site, especially those preserved within naturally deposited alluvial sediments, but potentially also objects that have been redistributed within fill soils. The potential for a buried archaeological resource includes sites and features that are Native American in origin, which could be eligible for listing on the CRHR and meet the definition of a tribal cultural resource.
The City consulted with FTBMI and SFBMI pursuant to PRC Sections 21080.3.1 and 21084.3(d).
FTBMI stated that their records confirmed the SLF results and indicated that there is either an undisclosed Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 88 tribal cultural resource or a high potential to encounter a tribal cultural resource in the project site; because of the highly sensitive nature of their records and the need to maintain its confidential status, FTBMI could not provide additional detail regarding these results, and instead emphasized the highly sensitive nature of the location and provided three mitigation measures that they requested be incorporated. SFBMI also indicated that there is potential for a tribal cultural resource to be in the project site but did not provide specific details to indicate whether there is a specific known resource, or if there is a potential to encounter an as-yet unidentified tribal cultural resource during ground-disturbing activities for the project. Based on the confidential information provided during the tribal consultation and supporting information provided in the archaeological assessment, the City, in its discretion, lacks the substantial evidence needed to confirm the presence of a specific known tribal cultural resource, but finds there is substantial evidence indicating there is a potential to encounter a tribal cultural resource during ground-disturbing activities for the project. Any impacts to tribal cultural resource from ground- disturbing activities would be potentially significant.
Under MM CR-1 through MM CR-3 project workers would be provided a training on the procedures to follow if an archaeological resource is discovered, an archaeologist would be on-site to monitor for archaeological resources, and a process for the inadvertent discovery of human remains would be followed. This would ensure impacts to archaeological resources would be less than significant with mitigation incorporated and would also apply to tribal cultural resources that are archaeological in nature.
MM TCR-1 and MM TCR-2 would ensure that tribal cultural resources, whether archaeological in nature or not, are identified and assessed by California Native American tribes who are geographically and culturally affiliated with the project site, by requiring tribal monitoring and consultation on any tribal cultural resource discoveries. MM TCR-2 would also ensure that if preservation in place is not feasible for any as-yet unidentified tribal cultural resources encountered during the project, affiliated tribes are consulted to identify appropriate forms of treatment that consider their cultural value.
Conclusion
The project would include implementation of MM CR-1 through MM CR-3 as mitigation for archaeological resources and includes addressing inadvertent discovery of archaeological resources and human remains. These measures would also apply to tribal cultural resources that are archaeological in nature. The project would also include implementation of MM TCR-1 and MM TCR-2 as mitigation for tribal cultural resources, including but not limited to those that are archaeological in nature. Upon implementation of these project-specific mitigation measures for tribal cultural resources, when carried out in concert with those for archaeological resources, impacts to tribal cultural resources would be less than significant with mitigation incorporated.
Mitigation Measures
MM TCR-1 Tribal Monitoring. The project developer shall retain a professional Tribal Monitor procured by the Fernandeño Tataviam Band of Mission Indians and San Fernando Band of Mission Indians (Tribes) to observe all ground-disturbing activities including, but not limited to, clearing, grubbing, grading, excavating, digging, trenching, plowing, drilling, tunneling, quarrying, leveling, driving posts, auguring, blasting, stripping topsoil or similar activity. Tribal Monitoring Services shall continue until confirmation is received from the project developer, in writing, that all scheduled activities pertaining to Tribal Monitoring are complete. If the project’s scheduled activities require the Tribal Monitor to leave the project for a period of time and return, confirmation shall be submitted to the Tribes by the project developer, in writing, upon completion of each set of scheduled activities and reasonable notice shall be submitted to the Tribes by project developer, in writing, prior to the start of each set of scheduled activities. If tribal cultural resources are encountered, the Tribal Monitor will have the authority to request that ground-disturbing Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 89 activities cease within 60 feet of discovery and a qualified archaeologist meeting Secretary of Interior standards retained by the project developer as well as the Tribal Monitor shall assess the find.
MM TCR-2 Disposition and Treatment of Inadvertent Discoveries of Tribal Cultural Resources.
The City of Santa Clarita and/or developer shall, in good faith, consult with the Fernandeño Tataviam Band of Mission Indians and San Fernando Band of Mission Indians on the disposition and treatment of any Tribal Cultural Resource encountered during all ground disturbing activities.
XIX. Utilities and Service Systems
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
Would the project:
(a) Require or result in the relocation or construction of new or expanded water, wastewater treatment or
stormwater 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 capacity to serve the project’s projected
demand in addition to the provider’s 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?
☐ ☐ ☒ ☐
Setting
The project site would require the construction of new utility infrastructure to connect to existing lines and mains along Soledad Canyon Road. SCV Water is the water purveyor serving the project site.
Wastewater facilities are operated and maintained by the Los Angeles County Sanitation District and the project site is within the jurisdictional boundaries of the Santa Clarita Valley Sanitation District. Storm drain facilities in the project site vicinity are within the Los Angeles County Storm Drain System, operated by the LACDPW. The project receives electricity from SCE and natural gas from SoCalGas.
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Draft Final Initial Study/Mitigated Negative Declaration 90 Environmental Evaluation
a) Would the project require or result in the relocation or construction of new or expanded water, wastewater treatment or stormwater drainage, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects?
Water Facilities
Less than Significant Impact. The project would include the installation of a new water line that would connect to an existing water line within Soledad Canyon Road. The demand and installation of new water supply lines and fire hydrants are evaluated and managed by SCV Water and LACFD, respectively, under their own independent environmental analysis. Construction of the new water line would be limited to on-site water distribution and minor off-site work associated with connections to the public main along Golden Valley Road. Prior to ground disturbance, the project construction contractor would notify SCV Water of proposed ground-disturbing activities to avoid water lines and disruption of water service.
Wastewater Facilities
Less than Significant Impact. The project would include the installation of a new sewer line that would connect to an existing wastewater line within Soledad Canyon Road. The project’s wastewater would be treated by the Santa Clarita Valley Sanitation District, which operates two wastewater reclamation plants (WRPs): Saugus WRP and Valencia WRP. The Saugus WRP provides primary, secondary, and tertiary treatment with a design capacity of 6.5 million gallons of wastewater per day. In 2020, the Saugus WRP produced an average of 4.6 million gallons per day (mgd) of tertiary recycled water (SCV Water 2021).
The Valencia WRP is a tertiary treatment plant with solids processing facilities. The plant provides primary, secondary, and tertiary treatment with a design capacity of 21.6 mgd of wastewater. In 2020, the Valencia WRP produced an average of 13.8 mgd of tertiary recycled water. The Valencia WRP processes all wastewater solids generated in the Santa Clarita Valley Sanitation District. In addition to these WRPs, new water reclamation facilities would be constructed by other developments in the Santa Clarita Valley, including Newhall Ranch and Vista Canyon. Given that the project is consistent with the population projections provided in the 2020 SCV Water UWMP, it is not anticipated that the project would require the construction of new wastewater treatment facilities, as the WRPs have sufficient capacity to accommodate additional growth. This is affirmed by the will-serve letter received from the Los Angeles County Sanitation District and included as Appendix K: LACSD Will Serve Letter. Therefore, the project would not result in the need to construct new or expanded wastewater treatment (reclamation) plants.
The project would require construction of a new on-site sewer to serve the new residential and manufacturing buildings. Impacts associated with wastewater infrastructure would primarily be confined to trenching for miscellaneous utility lines and connections to public infrastructure. Installation of wastewater infrastructure would be limited to on-site wastewater distribution, and minor off-site work associated with connections to the public main under Soledad Canyon Road. All off-site work would be performed in consultation and under the approval of the Los Angeles County Sanitation District, which operates the Santa Clarita Valley Sanitation District. The environmental impacts of construction and installation of new infrastructure associated with the project within the project site boundaries have been considered in the other resource-specific topical sections of this IS/MND (e.g., biological resources, cultural resources); mitigation measures identified in this IS/MND apply not only to the development of the residences and manufacturing building, but they are also applicable to the associated infrastructure within the project site boundaries. No additional physical impacts related to the construction of new wastewater facilities beyond physical disturbance of the project site itself are anticipated. Impacts related to the construction of new wastewater facilities would be less than significant.
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Draft Final Initial Study/Mitigated Negative Declaration 91 Stormwater Drainage Facilities
Less than Significant Impact. Refer to Section X, Hydrology and Water Quality, above, for an in-depth discussion of stormwater drainage facilities. As discussed therein, BMPs would be required to control stormwater runoff designed to capture stormwater runoff to the 85th percentile storm event. As such, stormwater runoff from the project site would not be expected to exceed the capacity of the existing or planned stormwater drainage systems and would not be expected to require the construction of new facilities. Therefore, impacts related to the construction of new stormwater facilities would be less than significant.
Energy Infrastructure
Less than Significant Impact. SCE would supply the project electricity from the existing electrical system. All electrical facility installation and connection to the existing system would be implemented in coordination and under the approval of the SCE. Therefore, the construction of new electric power facilities would not result in significant environmental effects. Accordingly, impacts would be less than significant.
Telecommunication Facilities
Less than Significant Impact. Construction-related activities, including grading and excavation, could encroach on telecommunication facilities. However, before construction begins, the Applicant would be required to coordinate with applicable regulatory agencies and telecommunication providers to locate and avoid or implement the orderly relocation of telecommunication facilities that would be affected. 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?
Less than Significant Impact. Water supply for the Santa Clarita Valley is provided by SCV Water, which was created on January 1, 2018, through the merger of the three water agencies in the Santa Clarita Valley. SCV Water serves 273,000 customers through 70,000 retail water connections, in an area approximately 195 square miles in size (SCV Water 2022). SCV Water receives water from four sources:
groundwater, recycled water, imported water, and banked water. According to Table 4-1 of the SCV Water 2020 UWMP, in 2020, SCV Water received approximately 26% of its water supply from groundwater, 0.7% from recycled water, 38.9% from imported water, and 34.4% from banked water.
SCV Water groundwater supply in this region is pumped from the Santa Clara River Valley East Groundwater Basin (SCV Water 2021).
The SCV Water 2020 UWMP has planned growth within the Santa Clarita Valley service area over the next 30 years. SCV Water has made an allowance for future water demand estimates. Future demand services are based on historical growth rates in the service area. As discussed in the SCV Water 2020 UWMP, adequate water supplies are projected to be available to meet SCV Water’s estimated water demand through 2045 under normal, single-dry, and multiple-dry year conditions (SCV Water 2021).
SVC Water forecasts for projected water demand are based on the population projections of SCAG, which rely on the adopted land use designations contained within the general plans that cover the geographic area within SVC Water’s service. The water use projections used in the 2020 SVC Water UWMP were based on the site’s existing “Mixed Use Corridor” land use designation on the City of Santa Clarita Land Use Map. The project would develop the site with a mixed use housing and manufacturing building, which is consistent with the MXC land use designation. Therefore, the project is in line with the population estimates of the 2020 SCV Water UWMP. As a result, SCV Water would incorporate the Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 92 water demands of the project site into future water demand projections in order to ensure a reliable supply of water for the project and future anticipated projects.
Furthermore, as long-term water supply is a significant concern in California, SCV Water can increase supply to meet future demands by 1) increasing the use of groundwater banking programs to ensure reliable water supply from wet to dry years; 2) increasing imported water purchases if available and if there is sufficient storage capacity; and 3) purchasing additional recycled water, if available. Collectively, these additional measures would ensure a reliable source of water for SCV Water and the project, currently and into the future. Therefore, impacts would be less than significant. c) Would the project result in a determination by the wastewater treatment provider which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments? Less than Significant Impact. As stated under Threshold XIX(a), above, the sewage flow from operation of the project would ultimately be conveyed to Santa Clarita Valley Sanitation District (operated by Los Angeles County Sanitation District). A will-serve letter received from the Los Angeles County Sanitation District states that there is sufficient capacity for the project (Los Angeles County Sanitation District 2019). Therefore, impacts would be less than significant. 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?
Less than Significant Impact. Implementation of the project would generate an incremental increase in solid waste volumes requiring off-site disposal during short-term construction and long-term operational activities. Solid waste generated by the project would be disposed at the Chiquita Canyon Landfill, the Antelope Valley Landfill, and/or the Sunshine Canyon Landfill.
Construction
The Chiquita Canyon Landfill, located approximately 10.2 miles to the northwest of the project site, has a maximum permitted throughput of 12,000 tons per day, has a cease operation date of January 1, 2047, and has a remaining capacity of approximately 54,420,179 tons, when last measured in 2020. The Antelope Valley Landfill is located approximately 33.9 miles to the northeast of the project site, has a maximum permitted throughput of 5,548 tons per day, has a cease operation date of April 1, 2044, and has a remaining capacity of 10,178,644 tons, when last measured in 2020. The Sunshine Canyon Landfill is located approximately 8.0 miles to the south of the project site, has a maximum permitted throughput of 12,100 tons per day, has a cease operation date of October 31, 2037, and has a remaining capacity of 54,079,158 tons when last measured in 2020 (LACDPW 2021).
Construction of the project would result in the generation of solid waste such as scrap lumber, concrete, residual wastes, packing materials, and plastics. Per CALGreen, 65% of construction and demolition waste must be diverted from landfills. As such, at least 65% of all construction and demolition debris from the site would be diverted. Additionally, CALGreen requires 100% of trees, stumps, rocks, and associated vegetation and soils resulting primarily from land clearing to be reused or recycled.
Any hazardous wastes that are generated during demolition and construction activities would be managed and disposed of in compliance with all applicable federal, state, and local laws. The remaining 35% of construction and demolition materials that are not required to be recycled would either be disposed of or voluntarily recycled at a solid waste facility with available capacity. The project would also be required to comply with the City’s Construction and Demolition Materials Management Ordinance (Municipal Code Chapter 15.46). Per the requirements of this ordinance, a Construction and Demolition Materials Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 93 Management Plan would be prepared for the project and submitted for approval to the City’s Environmental Services Division. This plan must be approved before grading or building permits are issued for the project. The City’s Construction and Demolition Materials Ordinance also requires a minimum of 65% of the entire project’s inert waste (dirt rock, bricks, etc.) and 65% of the remaining construction waste to be recycled or reused.
Construction waste is typically disposed of at inert landfills, which are facilities that accept materials such as soil, concrete, asphalt, and other construction and demolition debris. As of 2019, the Azusa Land Reclamation Landfill, located approximately 40 miles to the southeast of the project site, is the only permitted inert landfill within Los Angeles County. The landfill has a remaining capacity of 55,705,480 tons and is expected to remain open for approximately 26 years, as of 2019 (LACDPW 2021).
There are other facilities that process other construction and demolition waste in the county. Collectively, these facilities have a remaining capacity of approximately 148.4 million tons. The closest facility to the project site is the East Valley Diversion (formerly Looney Bins), located at 11616 Sheldon Street in Sun Valley. This facility is approximately 14.5 miles to the southeast of the project site and has a permitted capacity of 750 tons of waste per day. This facility has a mixed construction and demolition waste recycling rate of 75% (LACDPW 2021). Therefore, any construction and demolition debris requiring disposal at an inert landfill would be sufficiently accommodated by existing landfills.
For reasons stated above, project construction would not 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.g., CALGreen standards).
Non-recyclable construction waste generated by the project would be disposed at the Chiquita Canyon Landfill, the Antelope Valley Landfill, and/or the Sunshine Canyon Landfill. As described above, these landfills receive well below their maximum permitted daily disposal volume; thus, the construction waste generated by the project is not anticipated to cause the landfills to exceed their maximum permitted daily disposal volume. Furthermore, the Chiquita Canyon Landfill, the Antelope Valley Landfill, and/or the Sunshine Canyon Landfill are not expected to reach their total maximum permitted disposal capacities during the project’s construction period, which would end in 2026. The Chiquita Canyon Landfill, the Antelope Valley Landfill, and/or the Sunshine Canyon Landfill have sufficient daily capacity to accept solid waste generated by the project’s construction phase; therefore, impacts to landfill capacity associated with the project’s near-term construction activities would be less than significant.
Operational
Based on a daily waste generation factor of 1.42 pounds of waste per 100 square feet of industrial building area obtained from CalRecycle, long-term, ongoing operation of the project would generate approximately 1.61 tons of solid waste per day ([227,790 square feet ÷ 100 square feet] × 1.42] ÷ 2,000 pounds = 1.61 tons per day) (CalRecycle 2019). Pursuant to AB 939, at least 50% of the project’s solid waste is required to be diverted from landfills; therefore, the project would generate approximately
0.80 tons of solid waste per day requiring landfilling (1.61 tons per day × 50% = 0.80 tons per day).
Non-recyclable solid waste generated during long-term operation of the project would be disposed at the Chiquita Canyon Landfill, the Antelope Valley Landfill, and/or the Sunshine Canyon Landfill.
As described above, these landfills receive well below their maximum permitted daily disposal volume; thus, waste generated by the project’s operation is not anticipated to cause the landfills to exceed their maximum permitted daily disposal volume. Because the project would generate a relatively small amount of solid waste per day as compared to the permitted daily capacities at the receiving landfills, impacts to the Chiquita Canyon Landfill, the Antelope Valley Landfill, and/or the Sunshine Canyon Landfill facilities during the project’s long-term operational activities would be less than significant.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 94 e) Would the project comply with federal, state, and local management and reduction statutes and regulations related to solid waste?
Less than Significant Impact. Solid waste generated by the project site would be collected by Waste Management, then transferred to a transfer station where the waste would be sorted, processed, and sorted. From there, the waste would be taken to either the Chiquita Canyon Landfill, the Antelope Valley Landfill, or the Sunshine Canyon Landfill. These facilities are regulated under federal, state, and local laws. Additionally, the City is required to comply with relevant solid waste reduction and diversion requirements, including AB 939, AB 341, and AB 1327. Collectively, these regulations set statewide waste diversion goals as well as established solid waste and recycling governing standards for local agencies.
In addition, waste diversion and reduction during project construction and operations would be completed in accordance with CALGreen standards and City diversion requirements. As a result, the proposed project would comply with federal, state, and local management and reduction statutes and regulations related to solid waste. Impacts would be less than significant.
Conclusion
The project would not result in significant adverse environmental impacts related to the provision of utilities and service systems; no mitigation measures are necessary.
XX. Wildfire
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
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?
☐ ☐ ☒ ☐
Setting
The project site is located within a Very High Fire Hazard Severity Zone (FHSZ) in a Local Responsibility Area (Figure 5). The project site (approximately 35.2 acres) predominantly consists of disturbed habitat and is paved with asphalt, with the exception of a lone hill at the northwestern portion of the parcel. With the exception of the hill on the western portion of the subject property, the project site is flat. The hill is sparsely vegetated with sagebrush scrub, chamise chaparral, and upland mustards or star- thistle fields. Directly southwest of the project site are undeveloped hillsides with slopes averaging from 12 to 18 percent, the vegetation communities on the surrounding hillsides is dominated by sagebrush Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 95 scrub, coast live oak woodland, and disturbed habitat. The project site’s designation as a Very High FHSZ because of its proximity to these undeveloped hillsides (see Figure 5).
FHSZs are defined as a mapped area that designates zones (based on factors such as fuel, slope, and fire weather) with varying degrees of fire hazard (i.e., moderate, high, and very high). FHSZ maps analyze wildfire hazards and identify where wildfire hazards could be more severe and cause the greatest concern.
CAL FIRE is legally responsible for providing fire protection on all State Responsibility Area lands.
State Responsibility Area lands “are defined based on land ownership, population density and land use” and include over 31 million acres across the state. Because the project site is within a Very High FHSZ in a Local Responsibility Area, the local government is responsible for providing wildfire protection and suppression services.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 96 Figure 5. Fire Hazard Severity Zones for Local and State Responsibility Areas in a 1-mile radius from the project site.
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 97 Environmental Evaluation
a) If located in or near State Responsibility Areas or lands classified as very high fire hazard severity zones, would the project substantially impair an adopted emergency response plan or emergency evacuation plan?
Less than Significant Impact. The City has identified that the terrain and layout of the Santa Clarita Valley can affect evacuation during a wildfire event (City of Santa Clarita 2021). The City ensures that impacts to evacuation are addressed through collaboration with Los Angeles County Fire and Sheriff’s Departments and through implementation of the Hazard Mitigation Plan, which outlines several mitigation actions intended to facilitate emergency evacuation, including coordinating with the Los Angeles County Fire and Sheriff’s Departments to coordinate the Public Alert and Warning Notification System, coordinating with the LACFD to enhance emergency services to increase the efficiency of wildfire response and recovery activities, and incorporating mass notification procedures (e.g., text, social media) into evacuation notification efforts (City of Santa Clarita 2021). The Hazard Mitigation Plan also includes a goal of identifying safe evacuation routes in high-risk natural disaster areas and coordinating with the County of Los Angeles to identify emergency transportation routes.
The City’s General Plan and the County of Los Angeles Operational Area Disaster Route map for the City designate I-5, SR-14, and SR-126 as emergency evacuation routes (LACDPW 2010). The project site is not located within the immediate vicinity of these evacuation routes and is not expected to disrupt evacuation procedures along these highways. The County designates Soledad Canyon Road, which borders the project site on the north, as a secondary evacuation route (LACDPW 2010).
Any public right-of-way encroachments during project construction would require approval from the City. As described in Section XVII, Transportation, project-generated traffic would not substantially adversely affect the performance of nearby roadways, including Golden Valley Road. Therefore, emergency service response times and disaster evacuation routes would not be affected. Prior to operation, the project would receive all required permits and certificates for occupancy and operation, including those issued by the City Department of Building and Safety. Therefore, the project would not substantially interfere with or impair local emergency response or emergency evacuation plans, and impacts would be less than significant.
b) Due to slope, prevailing winds, and other factors, if located in or near State Responsibility Areas or lands classified as very high fire hazard severity zones, 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. The project is located within a Very High FHSZ. Topography of the project and surrounding area can increase fire behavior due to the hills and steep slopes. The region is subject to continual strong winds and seasonal Santa Ana winds, a local weather phenomenon that produces very dry, strong winds that historically spread wildfires. Fuels in the surrounding area are flashier fuels (grass and pyric shrubs), which can have faster rates of spread, particularly on steeper terrain and when winds align with topography. The project would also increase the potential for ignitions during construction and maintenance. Increased ignition sources may include mechanized equipment, vehicles, heavy equipment, cigarettes, and additional electrical infrastructure (power lines if overhead).
However, the project would be subject to the City Building Code pertaining to permits, building design and exterior materials, fire suppression systems, and backfilling and erosion control on slopes and in a Very High FHSZ. This includes local fire department approval of heavy equipment for grading activities and dust control compliance, which would include a water supply on-site. The project would be compliant with the City Fire Code, which incorporates, by reference, the 2022 California Fire Code, including Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 98 amendments made and adopted by the County of Los Angeles County and referred to as Title 32 of the Los Angeles County Code. These requirements include requirements pertaining to fire apparatus, access roads, turning radii, building identification, and marking of other structures, defensible space, vegetation clearance and maintenance (fuel modification areas), and water supply. The closest fire station to the project is LACFD Station 111, located at 26829 Seco Canyon Road, Valencia, California, approximately
1.2 miles from the project site. Additional fire protection could be provided by other fire stations in Santa Clarita, including Station 126 (Battalion 6 Headquarters), located at 26329 Citrus Street, approximately
1.3 miles west of the project site. The Santa Clarita General Plan Safety Element has an objective of fire response times of no more than 5 minutes in urbanized areas, 8 minutes in suburban areas, and 12 minutes in rural areas (City of Santa Clarita 2022b).
The project site’s proximity to undeveloped land with flashy fuels (fuels that ignite readily and are consumed rapidly when dry, e.g., grass, dried leaves) would potentially expose occupants to wildfire, however the implementation of mandatory design features such as fuel breaks, designated evacuation routes, and the accessibility to local fire stations would reduce the potential impacts from wildfire spread to less-than-significant levels.
c) If located in or near State Responsibility Areas or lands classified as very high fire hazard severity zones, 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. The project would have minimal associated infrastructure beyond what exists for adjacent development. As presented in the Section XIX, Utilities and Service Systems, the project would use or connect to existing water lines, sewer drainages, energy lines, and improved roads.
The project would be compliant with the City Fire Code pertaining to removal of vegetation a minimum of 30 feet from any structure and vegetation maintenance around any electrical equipment, resulting in minimal exacerbation of fire risk for the life of the project and minimal impacts to the environment.
Therefore, impacts would be less than significant.
d) If located in or near State Responsibility Areas or lands classified as very high fire hazard severity zones, 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. Extreme fire behavior can cause sterilized and hydrophobic soils, a main contributor to runoff issues post-fire that can lead to flooding and landslides, particularly in steeper terrain. However, fire behavior in the project site would be moderated due to vegetation clearing and maintenance per the Fire Code. The project site has been previously graded and does not pose a risk of landslides or downstream flooding. Project stormwater design would direct water flows to catchment basins as discussed in Section X, Hydrology and Water Quality. The location of the project site does not expose people or structures to downslope or downstream risk, therefore, impacts would be less than significant.
Conclusion
The project would not result in a significant adverse wildfire impact; no mitigation measures are necessary.
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Draft Final Initial Study/Mitigated Negative Declaration 99 XXI. Mandatory Findings of Significance
Environmental Issues
Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporated
Less Than
Significant
Impact
No Impact
(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 considerable? (“Cumulatively
considerable” 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?
☐ ☒ ☐ ☐
Environmental Evaluation
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 IV, Biological Resources, the project site supports suitable habitat for one special-status animal species (coastal California gnatcatcher) which has moderate potential to occur. If this species is present within the project site during construction, the project construction could result in a significant impact on this species. However, Mitigation Measures BIO-1 through BIO-9 have been identified to reduce potentially significant impacts to the coastal California gnatcatcher and other plant and animal species to less- than significant levels. These mitigation measures would require preconstruction surveys, biological monitoring during construction, exclusion areas, and protected tree replacement.
The project site does not support riparian habitat or other sensitive natural communities. However, to reduce potential indirect impacts to federally protected wetland due to impaired water quality downstream and the degradation of adjacent habitats, implementation of a SWPPP and project design features, including water quality treatment basins that would improve water quality before it flows downstream to the stormwater drainage basins, would reduce potential indirect impacts to the Santa Clara River system.
Therefore, indirect impacts related to federally protected wetlands would be less than significant.
As described in Section V, Cultural Resources, the project site does not support any known important examples of major periods in California history or prehistory. However, the significant grading and terracing of the hillside in the northwestern portion of the project site has the potential to produce previously unrecorded cultural material. The implementation of MM CR-1 through CR-3 and MM TCR-1 and TCR-2 would ensure that impacts to inadvertent discoveries would be less than significant.
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b) Does the project have impacts that are individually limited, but cumulatively considerable? (“Cumulatively considerable” 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.) Less than Significant Impact with Mitigation Incorporated. The project would result in potentially significant project-level impacts involving air quality, biological resources, cultural resources, geology and soils, hazards and hazardous materials, noise, and tribal cultural resources. However, mitigation measures have been identified that would reduce these impacts to less-than-significant levels.
Furthermore, the air quality, GHG, and transportation and traffic analyses presented in Section III, Section VIII, and Section XVII, respectively, of this IS/MND consider cumulative impacts. Specifically, the cumulative impacts analyses in this IS/MND consider to transportation may occur due to other projects in the vicinity of the Riverview project.
Of note, the Metrolink station adjacent to the project site is subject to improvements as described in the Antelope Valley Line (AVL) Capacity and Service Improvements Program EIR, which was finalized on November 16, 2021. The AVL project is scheduled to be completed between 2028 and 2030 and has been considered in the environmental analyses contained in this assessment.
All reasonably foreseeable future development in the city would be subject to the same land use and environmental regulations that have been described throughout this document. Furthermore, all development projects are guided by the policies identified in the City’s General Plan and by the regulations established in the City’s Municipal Code. Compliance with applicable land use and environmental regulations would ensure that environmental effects associated with the proposed project would not combine with effects from reasonably foreseeable future development in the city to cause cumulatively considerable significant impacts. Cumulative impacts would therefore be 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 detailed throughout this IS/MND, the proposed project would not exceed any significance thresholds or result in significant impacts in the environmental categories typically associated with indirect or direct effects on human beings, with the implementation of mitigation measures. As discussed in Section VII Geology and Soils, and Section XX Wildfire, the project could result in potentially significant impacts by natural disaster in the form of earthquake, landslide, or wildfire. However, specific design features such as siting outside of a landslide zone, and designing the project with ample evacuation options, mitigate the severity of these potential impacts. Therefore, impacts would be less than significant with mitigation incorporated.
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———. 2024a. Biological Resources Technical Report: Riverview Project. March 2024. Prepared for The Riverview Owner, LLC.
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———. 2024d. Hazardous Materials Assessment for Riverview Development Project. March 2024.
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4 LIST OF PREPARERS
CITY OF SANTA CLARITA
David Peterson, Senior Planner
Justin Sauder, Associate Planner
Hai Nguyen, Associate Planner
SWCA ENVIRONMENTAL CONSULTANTS
Bobbette Biddulph, Senior Project Manager
Shannon Pagan, Project Environmental Planner
Lucas Leibold, Staff Environmental Planner
Stuart Muerth, Staff Environmental Planner
Rob MacAller, Natural Resources Director
Stephanie Cimino, Cultural Resources Director
Liz Denniston, Senior Cultural Resources Team Lead
Chris Millington, Senior Archaeologist
Susan Zamudio-Gurrola, Architectural History Project Manager Erica Nicolay, Cultural Resources Project Manager
Mathew Carson, Paleontology Team Lead
Jasmyn Nolasco, Staff Paleontologist
Marty Kooistra, GIS Analyst
Danielle Desruisseaux, Project Technical Editor
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5 MITIGATION MONITORING AND REPORTING PROGRAM
This Mitigation Monitoring and Reporting Program (MMRP) has been prepared for the Riverview Development Project (project) based on the findings of the Initial Study/Mitigation Negative Declaration (IS/MND) prepared for the project.
5.1 Statutory Requirements
When a Lead Agency makes findings on significant environmental effects identified in an Mitigated Negative Declaration (MND), the agency must also adopt a “reporting or monitoring program for the changes to the project which it has adopted or made a condition of approval in order to mitigate or avoid significant effects on the environment” (Public Resources Code [PRC] Section 21081.6(a) and California Environmental Quality Act [CEQA] Guidelines Sections 15091(d) and 15097). The Mitigation Monitoring and Reporting Program (MMRP) is implemented to ensure that the mitigation measures and project revisions identified in the IS/MND are implemented. Therefore, the MMRP must include all changes in the project either adopted by the project proponent or made conditions of approval by the Lead or Responsible Agency.
5.2 Administration of the Mitigation Monitoring and
Reporting Program
The City of Santa Clarita (City) is the Lead Agency responsible for the adoption of the MMRP. The Riverview Owner LPV, LCC (Applicant), is responsible for implementation of the MMRP, in coordination with the City and other identified entities. According to State CEQA Guidelines Section 15097(a), a public agency may delegate reporting or monitoring responsibilities to another public agency or to a private entity that accepts the delegation. The City may delegate responsibility for verifying and documenting compliance with the MMRP to the Applicant as coordinator of the project and its construction, and the Applicant will be responsible for compliance. However, until mitigation measures have been completed, the City, as the Lead Agency, remains responsible for ensuring that the implementation of the measures occurs in accordance with the program.
5.3 Mitigation Measures
The MMRP table below is structured to enable quick reference to mitigation measures and the associated monitoring program based on the environmental resource. The numbering of mitigation measures correlates with numbering of measures found in the corresponding environmental analysis provided in the project’s IS/MND. The table also describes the timing for mitigation measure implementation (e.g.., when the measure shall be implemented) and the responsible parties—such as the Construction Contractor, Applicant, and/or City of Santa Clarita—that are responsible for ensuring implementation of all aspects of each measure.
Riverview Development Project
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Table 10. Mitigation and Monitoring Program
Mitigation
Measure Requirements of Measure Compliance
Method
Verification
Timing
Responsible
Parties
Air Quality
MM AIR-1 Diesel-powered Construction Equipment Requirements. During construction of the proposed project, the project contractor shall ensure all off-road diesel-powered construction equipment of 50 horsepower or more used for the project construction at a minimum meets the California Air Resources Board Tier 2 emissions standards equipped with level 3 diesel particulate filters. Verification shall be provided to the City of Santa Clarita Planning Division for confirmation, to the satisfaction of City staff.
Use construction
equipment specified,
meeting Tier 2
emissions standards
equipped with level 3
diesel particulate
filters
During construction
activities
Implementation:
Applicant and
Construction
Contractor
Verification:
City of Santa Clarita
Biological Resources
MM BIO-1 Pre-Construction Rare Plant Survey and Seed CollectionConservation. Prior to issuance of a grading permit, the Applicant shall have a qualified biologist (the Applicant shall submit the qualifications of the biologist to the City for review and approval) conduct a focused rare plant survey for slender mariposa lily within the undeveloped portion of the project site during the appropriate blooming period (March through June).
The survey
would consist of three passes, with one in April, May, and June. The survey shall consist of a maximum of three passes from March to June. Reference site checks would be made for the species to determine if the species is blooming in the project vicinity. If the reference site check is positive for the species, then the following survey shall determine the presence or absence of the species at the project site. The surveys would conform to the California Native Plant Society’s Botanical Survey Guidelines (2001); CDFW’s Protocols for Surveying and Evaluating Impacts to Special Status Native Plant Populations and Natural Communities (2018); and USFWS’ Guidelines for Conducting and Reporting Botanical Inventories for Federally Listed, Proposed and Candidate P lants
(2000). The results of the surveys would be documented in a report and submitted to the City.
Should the species be found at a count of 20 or higher, then construction of the occupied location shall be delayed until the individuals have gone to seed. Seeds shall be collected once the seed has matured, but prior to the seed capsules opening to disperse the seed. Seeds shall be stored in breathable paper bags in a cool, dry, and dark place.
The seeds would then be donated to a City-approved local conservation organization (e.g., Friends of the Santa Clara River) to be used in restoration projects.
If the species is found at the project site, then construction of the occupied location shall be delayed, and one of the following measures shall be implemented:
Alternative No. 1: The project shall compensate for the loss of the species at a 1:1 ratio through the planting of replacement slender mariposa lily bulbs within the landscaped areas of the residential portion of the project, which will be maintained by the future homeowner’s association in perpetuity.
Alternative No. 2: If replacement slender mariposa lily bulbs cannot be reasonably located to implement the first alternative, the project shall compensate for the loss of discovered specimens by collecting the seeds of the onsite individuals. Seed collection and storage will be conducted by an entity with extensive experience performing those tasks (such as S&S Seeds or the California Botanical Garden) and approved by the City. The project Applicant will then work with City-approved local Retain a City-
approved project
biologist
to ensure
compliance with
biological resource
mitigation measures
Prior to issuance of
grading permits
Implementation:
Applicant
Verification:
City of Santa Clarita
Riverview Development Project
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conservation organization (e.g., Friends of Santa Clara River) to be used in restoration projects. The Applicant shall provide the City with documentation of the seeds use.
MM BIO-2 Pre-construction Wildlife Survey. Prior to issuance of a grading permit, a qualified biologist (the Applicant shall submit the qualifications of the biologist to the City for review and approval) shall conduct a survey of the proposed impact areas and 50-foot buffer within 72 hours of the proposed activities. Any coastal whiptail, Southern California
legless lizard, California glossy snake, or Blainville’s horned lizard found would be relocated to a City-approved off-site location in suitable habitat for each species. If a San Diego desert woodrat midden is discovered during the survey, then the biologist would methodically relocate the midden material to suitable habitat (dense shrubs) within 50 feet of its location and outside of the project disturbance limits. The procedure would be implemented at a rate that would allow for the woodrat to flush from the midden. The results of the survey would be documented in a letter report to be submitted to the City.
Retain a City-
approved project
biologist
to ensure
compliance with
biological resource
mitigation measures
Prior to issuance of
grading permits
Implementation:
Applicant
Verification:
City of Santa Clarita
MM BIO-3 Biological Monitoring. Prior to the issuance of a grading permit, the Applicant shall submit the qualifications of the biologist(s) to the City for review and approval. The Applicant shall fund a City-approved Biological Monitor during project construction to monitor construction activities and to ensure compliance with all mitigation measures.
The Biological Monitor shall be present on-site during all native vegetation removal and initial ground-disturbing activities in undeveloped areas. Each day, before project activities begin, the Biological Monitor shall be responsible for conducting a pre-construction clearance survey and any wildlife (common or special-status) would be relocated off-site to a City-approved area.
With regard to the Crotch’s bumble bee only, if construction activity would impact the
6.04 acres of potential foraging and nesting habitat (native vegetation communities) during the Crotch’s bumble bee nesting period (February 1 through October 31), the Biological Monitor shall conduct a pre-construction survey for Crotch’s bumble bee within the aforementioned 6.04 acres of natural vegetation area prior to the start of ground- disturbing construction activities within that 6.04 acres occurring during the Crotch’s bumble bee nesting period (February 1 through October 31). The survey shall ensure that no nests for Crotch’s bumble bee are located within that 6.04-acre area. The pre- construction survey shall be based on recommendations described in the “Survey Considerations for California Endangered Species Act Candidate Bumble Bee Species,” released by CDFW on June 6, 2023, or the most current at the time of construction.
The focused survey shall be performed by a Biological Monitor with a CDFW-issued Scientific Collection Permit (SCP) in surveying for bumble bees and include at least three (3) survey passes that are not on sequential days or in the same week, preferably spaced two to four weeks apart. The timing of these surveys shall coincide with the Colony Active Period (April 1 through August 31 for Crotch’s bumble bee). Surveys may occur between 1 hour after sunrise and 2 hours before sunset. Surveys shall not be conducted during wet conditions (e.g., foggy, raining, or drizzling) and surveyors shall wait at least 1 hour following rain. Surveys may be conducted earlier than April 1 if other bees or butterflies are flying in the native vegetation communities on the project site.
Surveys shall not be conducted when it is windy (i.e., sustained winds greater than 8 mph). Within non-developed habitats, the Biological Monitor shall look for nest resources Retain a City-
approved project
biologist
to ensure
compliance with
biological resource
mitigation measures
Prior to issuance of
grading permits
Implementation:
Applicant
Verification:
City of Santa Clarita
Riverview Development Project
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Responsible
Parties
suitable for bumble bee use. Ensuring that all nest resources receive 100 percent visual coverage, the biologist shall watch the nest resources for up to five minutes, looking for exiting or entering worker bumble bees. Worker bees should arrive and exit an active nest site with frequency, such that their presence would be apparent after five minutes of observation. If a bumble bee worker is detected, then a representative shall be identified to species. If a nest is suspected, the Biological Monitor can block the entrance of the possible nest with a sterile vial or jar until nest activity is confirmed (no longer than 30 minutes).
Identification shall include the SCP-permitted Biological Monitor netting/capturing the representative bumble bee in appropriate insect nets, per the protocol in U.S. National Protocol Framework for the Inventory and Monitoring of Bees. The bee shall be placed in a clear container for observation and photographic documentation if able. The bee shall be photographed using a macro lens from various angles to ensure recordation of key identifying characteristics. If bumble bee identifying characteristics cannot be adequately captured in the container due to movement, the container shall be placed in a cooler with ice until the bumble bee becomes inactive (generally within 15 minutes). Once inert, the bumble bee shall be removed from the container and placed on a white sheet of paper or card for examination and photographic documentation. The bumble bee shall be released into the same area from which it was captured upon completion of identification.
Based on implementation of this method on a variety of other bumble bee species, they become active shortly after removal from the cold environment, so photography must be performed quickly.
If Crotch’s bumble bee nests are not detected, no further mitigation would be required.
The mere presence of foraging Crotch’s bumble bees would not require implementation of additional minimization measures because they can forage up to 10 kilometers from their nests. If nest resources occupied by Crotch’s bumble bee are detected within the construction area, no construction activities shall occur within 100 feet of the nest, or as determined by the SCP-permitted Biological Monitor through evaluation of topographic features or distribution of floral resources. The nest resources shall be avoided for the duration of the Crotch’s bumble bee nesting period (February 1 through October 31).
Outside of the nesting season, it is assumed that no live individuals would be present within the nest as the daughter queens (gynes) usually leave by September, and all other individuals (original queen, workers, males) die.
A written survey report shall be submitted to the City within 30 days of the pre- construction survey. The report shall include survey methods, weather conditions, and survey results, including a list of insect species observed and a figure showing the locations of any Crotch’s bumble bee nest sites or individuals observed. The survey report shall include the qualification/resume of the SCP-permitted Biological Monitor for identification of photo vouchers, detailed habitat assessment, and photo vouchers. If Crotch’s bumble bee nests are observed, the survey report shall also include recommendations for avoidance, and the location information shall be submitted to the California Natural Diversity Database (CNDDB) at the time of, or prior to, submittal of the survey report.
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MM BIO-4 Demarcation of Disturbance Limits. Prior to commencement of earthwork in the undeveloped portion of the project site, the construction limits shall be clearly demarcated (e.g., installation of flagging or temporary high-visibility construction fence), as recommended by the Biological Monitor. All construction activities including equipment staging and maintenance shall be conducted within the marked disturbance limits to prevent inadvertent disturbance to sensitive vegetation communities outside the limits of work. The flagging shall be maintained throughout construction.
Retain a City-
approved project
biologist to ensure
compliance with
biological resource
mitigation measures
Prior to issuance of
grading permits,
during construction
Implementation:
Applicant and
Construction
Contractor
Verification:
City of Santa Clarita
MM BIO-5 Stormwater Pollution Prevention Plan. Prior to issuance of a grading permits for construction activity that would require more than one acre of earthwork, the project developer shall develop a Stormwater Pollution Prevention Plan (SWPPP) that provides for require erosion and sediment control Best Management Practices (BMPs) to be implemented during construction activities. The SWPPP shall be submitted to the City for review and approval prior to the issuance of a grading permit. For construction activities on individual lots that are less than one acre in size, a site-specific listing of BMPs shall be prepared using appropriate and feasible measures included in the primary SWPPP document and shall be submitted to the City for review and approval prior to the issuance of a grading permit. The site-specific SWPPP shall include measures including, but not be limited to: (1) the regular use of water trucks or other means of site irrigation to minimize fugitive dust during earthmoving and prevent fugitive dust from escaping the property boundary; (2) prohibition of vehicle fueling on-site; and (3) requirement that secondary containment be used for the temporary use all hazardous materials during construction activities and such containment shall be located as far as feasible from jurisdictional resources. Subsequent to approval by the City, the requirements of the SWPPP shall be implemented prior to and during construction activities, as specifically required in the SWPPP.
At the culvert in the northwest portion of the project site, a silt fence barrier shall be constructed around it prior to the start of construction activities. Wooden posts supporting the silt fence shall be spaced 2 to 3 feet apart and driven securely into the ground; a minimum of 18 to 20 inches deep. The bottom edge of the silt fence is required to extend across the bottom of the trench and the trench shall be backfilled and compacted to prevent stormwater and sediment from discharging underneath the silt fence. Silt fences shall be inspected weekly and immediately after storm events to ensure they are intact and that there are no gaps where the fence meets the ground or tears along the length of the fence. If gaps or tears are found during the inspection, the fabric is required to be repaired or replaced immediately.
Retain a City-
approved project
biologist to ensure
compliance with
biological resource
mitigation measures
Prior to issuance of
grading permits
Implementation:
Applicant
Verification:
City of Santa Clarita
MM BIO-6 Invasive Plant Species Prevention. The project shall not include invasive plant species listed on the California Invasive Plant Council inventory in project landscaping palettes.
The City shall review and approve project landscape palettes to ensure that invasive plant species are excluded. In addition, to prevent the spread of invasive plant species during construction and until the establishment of common landscaped areas associated with the project (for a period of up to 5 years):
• All equipment shall be washed prior to entering and prior to leaving the project site in an upland location where any seed material from invasive species will be contained.
Prevent spread of
invasive plant species
to ensure compliance
with biological
resource mitigation
measures
Prior to issuance of
grading permits,
during construction
Implementation:
Applicant
Verification:
City of Santa Clarita
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 114
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Measure Requirements of Measure Compliance
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Responsible
Parties
• All vegetative material removed from the project impact footprint shall be transported in a covered vehicle and will be disposed of at a certified disposal site.
MM BIO-7 Exterior Permanent Lighting. To address indirect impacts to special-status wildlife due to lighting, exterior lighting associated with final project development shall be designed to be minimal (only as needed for security and safety) to lessen the attraction of birds, bats, and other sensitive wildlife species.
Design exterior lights
to be minimal
Prior to approval of
building permits
Implementation:
Applicant
Verification:
City of Santa Clarita
MM BIO-8 Nesting Bird Avoidance. Project construction shall be conducted in compliance with the conditions set forth in the MBTA and California Fish and Game Code to protect active bird/raptor nests. To the maximum extent feasible, vegetation removal shall occur during the non-breeding season for nesting birds (generally late September to early March) and nesting raptors (generally early July to late January) to avoid impacts to nesting birds and raptors. If the project requires that work be initiated during the breeding season for nesting birds (March 1–September 30) and nesting raptors (February 1–June 30), in order to avoid direct impacts on active nests, a pre-construction survey shall be conducted in the study area (defined as a 500-foot buffer around the project site) by qualified biologists (someone who has more than 3 years of experience conducting nesting bird surveys in the project region) for nesting birds and/or raptors within 3 days prior to project activities. If the biologist does not find any active nests within or immediately adjacent to the impact areas, the vegetation clearing/construction work shall be allowed to proceed.
If the biologist finds an active nest within or immediately adjacent to the construction area and determines that the nest may be impacted or breeding activities substantially disrupted, the biologist shall delineate an appropriate buffer zone around the nest, depending on the sensitivity of the species and the nature of the construction activity.
To protect any nest site, the following restrictions to construction activities shall be required until nests are no longer active, as determined by a qualified biologist:
1) clearing limits shall be established within a buffer around any occupied nest; and 2) access and surveying shall be restricted within the buffer of any occupied nest, unless otherwise determined by a qualified biologist. The buffer shall be up to 300 feet for non- raptor nesting birds and up to 500 feet for nesting raptors, based upon the biologist’s determination of potential effect of project activities on the nest. Construction can proceed into the buffer when the qualified biologist has determined that the nest is no longer active.
Conduct vegetation
removal and site
distance between
September 30 and
January 31. If this is
not possible, conduct
preconstruction
nesting bird and
raptor surveys.
During construction
activities on the
project site, between
February 1 and
September 30.
Implementation:
Applicant and
Construction
Contractor
Verification:
City of Santa Clarita
MM BIO-9 Protected Tree Replacement. The Applicant would comply with the City of Santa Clarita Oak Tree Ordinance and would obtain an oak tree permit prior to the issuance of the grading permit for the project. Conditions of the oak tree permit may include the payment of a fee, planting of replacement trees on the project site, or donation of boxed trees to the City or other approved public agency to be used elsewhere in the city.
The nine trees to be removed shall be replaced by a tree of the same species at a ratio determined by the Urban Forestry Division of the City of Santa Clarita, with a minimum of 55 replacement trees required. All replacement trees shall be at least a 24‐gallon specimen in size and measure 2 inches or more in diameter, as measured from Obtain an oak tree
permit, and submit
quarterly tree
inspection reports
prepared by a City-
approved oak tree
expert
Prior to issuance of
grading permits, and 2
years following
planting of
replacement trees
Implementation:
Applicant
Verification:
City of Santa Clarita
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 115
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Parties
approximately 4 feet above the base. Replacement trees shall be certified as being grown from a seed source collected in Los Angeles County.
For replacement trees planted on the project site, the Applicant shall be responsible for submitting quarterly tree inspection reports to the City prepared by a certified oak tree expert that shall be required to document the condition of the trees. The inspection and reporting would be required for 2 years following the planting of the replacement trees.
Any tree that fails during the 2-year period would be replaced by a 24‐gallon specimen of the same species and then monitored for an additional 2 years.
Cultural Resources
MM CR-1 Archaeological Monitoring. Prior to ground-disturbing activities, the Applicant and/or subsequent responsible parties should retain a Principal Investigator/Archaeologist, meeting the Secretary of the Interior’s Standards, and with experience in California prehistoric and historic resources (experience within Los Angeles County preferred), to complete the following: compose a Cultural Resource Monitoring and Inadvertent Discovery Plan (Plan), manage archaeological monitoring, and address any inadvertent discoveries identified during project implementation. The Plan shall cover both development of the 35.2-acre project site as well as any necessary off-site improvements (e.g., transportation and infrastructure improvements) associated with the project. Proof of retainment of the Principal Investigator/Archaeologist should be provided to the City prior to the granting of a grading permit. The purpose of the Plan is to outline archaeological monitoring protocols and a program of treatment and mitigation in the case of an inadvertent discovery of archaeological resources during ground-disturbing phases and to provide for the proper identification, evaluation, treatment, and protection of any archaeological resources in accordance with CEQA throughout the duration of the project. Existence and importance of adherence to this Plan should be stated on all project site plans intended for use by those conducting the ground-disturbing activities.
The Principal Investigator/Archaeologist should manage archaeological monitoring conducted by archaeological technicians during initial ground disturbances. Initial excavation is defined as initial construction-related earth moving 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. The retained Principal Investigator/Archaeologist should oversee and establish monitoring efforts as needed (increase, decrease, or discontinue monitoring frequency) based on the observed potential for construction activities to encounter archaeological deposits or material. The archaeological monitor should be responsible for maintaining daily monitoring logs. The requirement for archaeological monitoring should be noted on all construction plans to ensure implementation. Upon completion of all ground-disturbing activities, an archaeological monitoring report should be prepared within 60 days following completion of ground disturbance and submitted to the City for review. This report should document compliance with approved cultural resource mitigation, all monitoring efforts, and include an appendix with daily monitoring logs. The final report should be submitted to the City and the SCCIC.
Retain a qualified
archaeologist, prepare
required Plan, and
conduct monitoring
Prior to
commencement of
construction,
monitoring to occur
during construction
Implementation:
Applicant
Verification:
City of Santa Clarita
Riverview Development Project
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Verification
Timing
Responsible
Parties
MM CR- 2 Worker Environmental Awareness Program (WEAP) Training. All construction personnel and monitors who are not trained archaeologists should be briefed regarding unanticipated discoveries prior to the start of ground-disturbing activities. A basic presentation should be prepared and presented by a qualified archaeologist to inform all personnel working on the project about the archaeological sensitivity of the area.
The purpose of the WEAP training is to provide specific details on the kinds of archaeological materials 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 should also be instructed on the proper procedures to follow in the event that archaeological resources or human remains are uncovered during ground- disturbing activities. These procedures include work curtailment or redirection, and the immediate contact of the on-call archaeologist and if appropriate, tribal representative.
Necessity of training attendance should be stated on all project site plans intended for use by those conducting the ground-disturbing activities.
Retain a qualified
archaeologist to
create a Worker
Environmental
Awareness Program
Prior to
commencement of
construction
Implementation:
Applicant
Verification:
City of Santa Clarita
MM CR-3 Inadvertent Discovery Clause. In the event that potential prehistoric or historic-era archaeological resources (sites, features, or artifacts) are exposed during construction activities for the project, all construction work occurring within 50 feet of the find shall immediately stop and the Principal Investigator/Archaeologist notified immediately in order 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 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 shall be required. If archaeological resources are discovered or are suspected to be of Native American origin, each of the consulting tribes for the project should also be notified.
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, PRC Section 5097.98, and State 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 area (within 100 feet of the find) 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 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 should then complete their inspection and determine, in consultation with the property owner, the treatment and disposition of the human remains.
Immediately cease
work in the vicinity of
an archaeological
resource find and
retain a qualified
archaeologist to
assess the find.
During ground-
disturbing activities
Implementation:
Applicant
Verification:
City of Santa Clarita
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 117
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Measure Requirements of Measure Compliance
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Verification
Timing
Responsible
Parties
Geology and Soils
MM GEO-1 Structural Engineering and Setback Requirements. Prior to issuance of a grading permit, the Applicant shall consult a qualified structural engineer regarding the design of structural components (i.e., floor slab support) of the building to reduce adverse impacts associated with fault rupture, strong seismic ground shaking, ground failure, and liquefaction. Design elements of structures for human occupancy should include a setback of 75 feet from the San Gabriel Fault, and pipelines (including gas, water, storm drain, and sewer) shall be constructed to allow flexure (Allan E. Seward Engineering Geology, Inc. 2007).
During construction of the proposed project, the developer shall implement all recommendations provided in the project-specific geotechnical study, including, but not limited to, removal of unsuitable soils and uncertified fills, and over-excavation and recompacting of soils within the project site. Typical hillside grading development and grading ground improvement shall be implemented to withstand the anticipated ground shaking and static and seismic-induced settlement.
Retain a City-
approved structural
engineer to ensure
compliance with
engineering
requirements
Prior to issuance of
building permits and
during construction
Implementation:
Applicant
Verification:
City of Santa Clarita
MM GEO-2 Paleontological Resource Monitoring. The developer shall implement the following:
a. Retain a Qualified Professional Paleontologist: A Project Paleontologist, defined as one who meets the Society of Vertebrate Paleontology standards for a qualified professional paleontologist, should be retained to carry out all regulatory compliance measures and protocols related to paleontological resources.
b. Conduct Worker Training: The Project Paleontologist should develop WEAP training to educate the construction crew on the legal requirements for preserving fossil resources, as well as the procedures to follow in the event of a fossil discovery. This training program should be given to the crew before ground-
disturbing work begins and should include handouts to be given to new workers as needed.
c. Monitor for Paleontological Resources: Full-time monitoring should be required in areas mapped as Holocene and late Pleistocene young alluvium, undivided (Qya) when ground-disturbing activities impact previously undisturbed sediments greater than or equal to 5 feet below ground surface, or in areas mapped as Pleistocene to late Pliocene Saugus Formation, undivided (QTs) (regardless of depth). Monitoring should not be required when ground- disturbing activities impact only artificial fill, previously disturbed sediments, and areas mapped as Qya at depths less than 5 feet below ground surface.
Monitoring should be conducted by a paleontological monitor who meets the standards of the SVP and should be supervised by the Project Paleontologist, who may periodically inspect construction activities to adjust the level of monitoring in response to subsurface conditions. Monitoring efforts can be increased, reduced, or ceased entirely if determined adequate by the Project Paleontologist in consultation with the Applicant and the City. Paleontological monitoring should include inspection of exposed sedimentary units during active excavations within sensitive geologic sediments. The monitor should have authority to temporarily divert activity away from exposed fossils to Prepare and
implement a
Paleontological
Resources Monitoring
and Mitigation Plan
Prior to and during
construction activities
Implementation:
Applicant
Verification:
City of Santa Clarita
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 118
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Responsible
Parties
evaluate the significance of the find and, should the fossils be determined significant, professionally and efficiently recover the fossil specimens and collect associated data. The monitor should record pertinent geologic data and collect appropriate sediment samples from any fossil localities. Recovered fossils should be prepared to the point of curation, identified by qualified experts, listed in a database to facilitate analysis, and deposited in a designated paleontological repository (e.g., Natural History Museum of Los Angeles County).
d. Prepare a Paleontological Resources Monitoring Report: Upon conclusion of ground-disturbing activities, the Project Paleontologist overseeing paleontological monitoring should prepare a final paleontological resources monitoring report that documents the paleontological monitoring efforts for the project and describes any paleontological resources discoveries observed and/or recorded during the life of the project. If paleontological resources are curated, the final report and any associated data pertinent to the curated specimen(s) should be submitted to the designated repository. A copy of the final report should be filed with the City.
Hazards and Hazardous Materials
MM HAZ-1 Soil Management Plan. The developer and/or project contractor shall prepare and implement a Soil Management Plan for the removal of any identified contaminated soils and their transportation off-site. The Soil Management Plan shall be prepared in coordination with the City and the Los Angeles County Fire Department (as the Certified Unified Program Agency) and in accordance with all relevant and applicable federal, state, and local laws and regulations that pertain to the transportation and disposal of hazardous materials and waste. The Soil Management Plan shall:
• describe the methodology to identify and manage (reuse or off-site disposal) contaminated soil during soil excavation and/or construction; and • provide protocols for confirmation sampling, segregation and stockpiling, profiling, backfilling, disposal, guidelines for imported soil, and backfill approval from the DTSC Information Advisory on Clean Imported Fill Material.
The Soil Management Plan shall be implemented during project construction.
Prepare and
implement a Soil
Management Plan
Prior to and during
construction activities
Implementation:
Applicant and
Construction
Contractor
Verification:
City of Santa Clarita
Noise
MM NOISE-1 Noise Abatement during Construction of Light Manufacturing Lot. The following noise control and/or sound abatement measures shall be implemented during construction of Lot 5, which is the lot that is planned for the light manufacturing land use:
A. Site Preparation:
1. To the extent practicable, earthwork on the east side of the existing hill on Lot 5 shall start as far east and possible and proceed in an east-to-west direction to take advantage of the distance between the site preparation activity and the Action Family Rehab facility and the sound-blocking effects of the unworked terrain that should naturally occlude line-of-sight between this construction process and this noise-sensitive land use to the northwest.
Approach earthwork
as prescribed on the
light manufacturing
lot; install specified
noise barriers during
construction
During construction,
specifically during the
site preparation,
grading, and paving
phases of the light
manufacturing lot
Implementation:
Applicant and
Construction
Contractor
Verification:
City of Santa Clarita
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 119
Mitigation
Measure Requirements of Measure Compliance
Method
Verification
Timing
Responsible
Parties
Consistent with acoustical principles for noise reduction afforded by such natural features, this line-of-sight occlusion should yield the needed decibel reduction at this receptor and result in 8-hour Leq exposure levels that are compatible with FTA guidance (80 dBA).
2. Should line-of-sight occlusion not be feasible per A.1 above, then along or within the property line where the project site adjoins the Action Rehab facility, a 20-foot-tall temporary barrier shall be installed made of typical outdoor-appropriate plywood sheeting, acoustical sound blankets, or other materials (having sound transmission class [STC] 20 or better) to ensure line-of-
sight occlusion between operating project construction equipment and the Action Family Rehab land use.
B. Grading and Paving: An appropriate temporary barrier shall also be constructed prior to the grading and paving phases and shall remain in place until these phases of the construction are completed. The grading and phasing barrier shall be at least a 12-foot- tall temporary barrier made of typical outdoor-appropriate plywood sheeting, acoustical sound blankets, or other materials (having sound transmission class [STC] 20 or better) along or adjacent to the property line where the project site adjoins the Action Family Rehab facility,
Tribal Cultural Resources
MM TCR-1 Tribal Monitoring. The project developer shall retain a professional Tribal Monitor procured by the Fernandeño Tataviam Band of Mission Indians and San Fernando Band of Mission Indians (Tribes) to observe all ground-disturbing activities including, but not limited to, clearing, grubbing, grading, excavating, digging, trenching, plowing, drilling, tunneling, quarrying, leveling, driving posts, auguring, blasting, stripping topsoil or similar activity. Tribal Monitoring Services shall continue until confirmation is received from the project developer, in writing, that all scheduled activities pertaining to Tribal Monitoring are complete. If the project’s scheduled activities require the Tribal Monitor to leave the project for a period of time and return, confirmation shall be submitted to the Tribes by the project developer, in writing, upon completion of each set of scheduled activities and reasonable notice shall be submitted to the Tribes by project developer, in writing, prior to the start of each set of scheduled activities. If tribal cultural resources are encountered, the Tribal Monitor will have the authority to request that ground-disturbing activities cease within 60 feet of discovery and a qualified archaeologist meeting Secretary of Interior standards retained by the project developer as well as the Tribal Monitor shall assess the find.
Tribal Monitor
procured by the
Fernandeño Tataviam
Band of Mission
Indians and San
Fernando Band of
Mission Indians
(Tribes) to observe all
ground-disturbing
activities
Prior to and during
construction
Implementation:
Applicant
Verification:
City of Santa Clarita
MM TCR-2 Disposition and Treatment of Inadvertent Discoveries of Tribal Cultural Resources.
The City of Santa Clarita and/or developer shall, in good faith, consult with the Fernandeño Tataviam Band of Mission Indians and San Fernando Band of Mission Indians on the disposition and treatment of any Tribal Cultural Resource encountered during all ground disturbing activities.
Fernandeño Tataviam
Band of Mission
Indians and San
Fernando Band of
Mission Indians
should Tribal Cultural
Resources be
encountered
During ground-
disturbing activities
Implementation:
Applicant
Verification:
City of Santa Clarita
Riverview Development Project
Draft Final Initial Study/Mitigated Negative Declaration 120
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