Exhibit H - Initial Study/Mitigated Negative Declaration — Rialto City Council, February 24, 2026 (part 1 of 2)

PUBLIC REVIEW DRAFT
Cit
y of Rialto 6th Cycle Housing Element Update (2021-2029) Initial Study and Mitigated Negative Declaration
October 2025
Le
ad Agency:

City of Rialto
Sandra Robles - Senior Planner
Community Development Department
150 South Palm Avenue
Rialto, CA 92376
909-820-2505
[email protected]

CITY OF
RIALTO
Rialto 6th Cycle HEU
Initial Study/Mitigated Negative Declaration
Page i October 2025
Table of Contents

1.0 Introduction ........................................................................................................................... 1

1.1 Project Overview................................................................................................................... 1

1.2 Statutory Authority And Requirements .................................................................................. 1

1.3 Incorporation By Reference ................................................................................................... 3

1.4 Environmental Resource Topics ............................................................................................. 4

1.5 Summary Of Findings ............................................................................................................ 4

1.6 Initial Study Public Review Process ........................................................................................ 5

1.7 Project Applicant(S)/Sponsor(S) ............................................................................................. 5

1.8 Document Organization ........................................................................................................ 6

2.0 Project Description ................................................................................................................. 7

2.1 Location ................................................................................................................................ 7

2.2 Environmental Setting ........................................................................................................... 7 Physical Setting ..................................................................................................................... 7 Population ............................................................................................................................ 7 Housing ............................................................................................................................ 8 General Plan ......................................................................................................................... 8 Zoning ............................................................................................................................ 9

2.3 Background ......................................................................................................................... 11 Housing Element State Law Mandates ................................................................................ 11 Regional Housing Needs Assessment .................................................................................. 12 Rhna Allocation .................................................................................................................. 13

2.4 Project Characteristics ........................................................................................................ 14 Goals And Policies ............................................................................................................... 14 Housing Programs............................................................................................................... 15 Candidate Housing Sites Realistic Development Capacity .................................................... 17

2.5 Housing Element Implementation Program – Ceqa Project .................................................. 19

2.6 Future Development ........................................................................................................... 20 Ministerial (By Right) Review .............................................................................................. 20 Discretionary Review .......................................................................................................... 21

2.7 Project Phasing ................................................................................................................... 21

2.8 Discretionary Actions, Permits, And Other Project Approvals ............................................... 22 Rialto 6th Cycle HEU
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3.0 Initial Study Checklist ........................................................................................................... 35

4.0 Environmental Analysis ........................................................................................................ 37

4.1 Aesthetics ........................................................................................................................... 38

4.2 Agriculture and Forestry Resources .................................................................................... 41

4.3 Air Quality .......................................................................................................................... 43

4.4 Biological Resources ........................................................................................................... 50

4.5 Cultural Resources .............................................................................................................. 56

4.6 Energy ................................................................................................................................ 62

4.7 Geology and Soils ............................................................................................................... 65

4.8 Greenhouse Gas Emissions ................................................................................................ . 73

4.9 Hazards and Hazardous Materials ....................................................................................... 76

4.10 Hydrology and Water Quality.............................................................................................. 83

4.11 Land Use and Planning ........................................................................................................ 89

4.12 Mineral Resources .............................................................................................................. 98

4.13 Noise ................................................................................................................................ 100

4.14 Population and Housing .................................................................................................... 109

4.15 Public Services .................................................................................................................. 114

4.16 Recreation ........................................................................................................................ 118

4.17 Transportation .................................................................................................................. 120

4.18 Tribal Cultural Resources .................................................................................................. 126

4.19 Utilities and Service Systems ............................................................................................. 128

4.20 Wildfire ............................................................................................................................ 133

4.21 Mandatory Findings Of Significance .................................................................................. 135

5.0 References ......................................................................................................................... 137 Appendix A: Candidate Housing Sites Inventory

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1.0 INTRODUCTION

1.1 Project Overview
The Housing Element is one of the State -mandated General Plan elements and must be updated every eight years to address existing and forecast housing needs across all segments of the community. In accordance with these requirements, the City of Rialto (“City”) has completed the City of Rialto 6th Cycle Housing Element Update (2021 -2029), which is a comprehensive update to the City’s 5 th Cycle Housing Element. The 6th Cycle Housing Element provides policies, programs, and actions that support and create the framework for production, preservation, and maintenance of the City’s housing stock for all income levels for the 2021 to 2029 planning period.

Kimley-Horn and Associates (Kimley -Horn) has prepared this Initial Study for the City to assess whether there may be significant environmental impacts associated with the proposed 6th Cycle Housing Element Update Project (“Project” or “HEU”). The Project involves 258 candidate housing sites (i.e., parcels) for rezoning within the City’s boundaries. The HEU estimates a total potential housing development capacity of 16,197 dwelling units (“DU”), including accessory, entitled Specific Plans, and proposed rezones. This shows a surplus of approximately 96 percent ( 7,925 DU) over the City’s Regional Housing Needs Assessment (RHNA) of 8,272 DU. The proposed rezone strategies on the candidate housing sites have a realistic housing development capacity of 8,587 DU and a maximum housing development capacity of 16,198 DU. This Initial Study evaluates the potential environmental impacts from a maximum hou sing development capacity of 13,674 DU when accounting for a maximum of 128 accessory dwelling units (ADU) and an existing housing development capacity of 2,652 DU. To facilitate the future development of housing on the candidate housing sites, and to be found in substantial compliance with State law pursuant to California Government Code (“ Government Code ”) § 65583, subdivision (c)(1)(A) and § 65583.2, subdivision (c), the Project includes amendments to the Rialto General Plan (“General Plan”) and Rialto Municipal Code (“Rialto Code”).

1.2 Statutory Authority and Requirements
This Initial Study has been prepared in accordance with the California Environmental Quality Act (CEQA) (Public Resources Code § 21000 et seq.) and the State CEQA Guidelines (California Code of Regulations [CCR], Title 14, § 15000 et seq.). Pursuant to State CEQA Guidelines § 15063, the purpose of this Initial Study is to determine whether the proposed Project may have a significant effect on the environment and to inform the decision whether to prepare an Environmental Impact Report (EIR), Negative Declaration (ND), or Mitigated Negative Declaration (MND).

Lead Agency
The Lead Agency is the public agency with primary responsibility for approving or carrying out a project.

When multiple public agencies are involved, State CEQA Guidelines § 15051 provides criteria for determining the Lead Agency. In accordance with State CEQA Guidelines § 15051(b) (1), “the Lead Agency will normally be the agency with general governmental powers, such as a city or county, rather than an agency with a single or limited purpose.” Based on this criterion and pursuant to State CEQA Guidelines § 15367, the City of Rialto is the Lead Agency for the proposed Project.

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Responsible and Trustee Agencies
Responsible and Trustee Agencies are defined in State CEQA Guidelines § § 15381 and 15386. A Responsible Agency is a public agency, other than the Lead Agency , which has discretionary approval authority over some aspect of the project. A Trustee Agency is a state agency with jurisdiction over natural resources that may be affected by the project. This Initial Study and proposed MND have been submitted to the State Clearinghouse for distribution to applicable Responsible and Trustee Agencies. These agencies may rely on this document for any necessary permits or approvals related to implementation of the proposed Project.

Initial Study
State CEQA Guidelines § 15063(b) states that if the Lead Agency determines, based on substantial evidence in the record, that a project may have a significant effect on the environment, the Lead Agency shall prepare an EIR. If there is no substantial evidence of a significant effect, the Lead Agency may instead prepare a ND. If potentially significant impacts are identified but can be reduced to a less than significant level through mitigation, the Lead Agency may prepare an MND.

The purposes of an Initial Study, as described in State CEQA Guidelines § 15063(c), include:
• Provide the Lead Agency with information to use as the basis for deciding whether to prepare an EIR or a ND;
• Enable an applicant or Lead Agency to modify a project, mitigating adverse impacts before an EIR is prepared, thereby enabling the project to qualify for a ND; • Assist in the preparation of an EIR, if one is required; • Facilitate environmental assessment early in the design of a project; • Provide documentation of the factual basis for the finding in a ND that a project will not have a significant effect on the environment;
• Eliminate unnecessary EIRs; and
• Determine whether a previously prepared EIR could be used with the project.

This Initial Study is intended to serve as an informational document for the Lead Agency and Responsible Agencies considering discretionary actions related to the proposed Project, if any.

Determination to Prepare a Negative or Mitigated Negative Declaration State CEQA Guidelines § 15070 provides that a public agency shall prepare a proposed ND or MND when:
a) The Initial Study shows no 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 the 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
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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.

Mitigation Measures
Under State CEQA Guidelines § 15041, a Lead Agency may require feasible changes to a project to substantially lessen or avoid significant environmental effects. “Feasible” is defined in State CEQA Guidelines § 15364 as capable of being accomplished in a successful manner within a reasonable period of time, considering economic, environmental, legal , social, and technological factors. State CEQA Guidelines § 15126.4 requires mitigation measures to meet applicable constitutional requirements, including:
• A clear nexus between the mitigation measure and a legitimate governmental interest; and • A rough proportionality between the mitigation required and the project’s impact.

Mitigation measures take various forms as defined in State CEQA Guidelines § 15370:
• Avoiding the impact altogether by not taking a certain action or parts of an action. • Minimizing impacts by limiting the degree or magnitude of the action and its implementation. • Rectifying the impact by repairing or restoring the affected environment. • Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action.
• Compensating for the impact by replacing or providing substitute resources or environment , including through permanent protection of such resources in the form of conservation easements.

Mitigation Monitoring and Reporting Program (MMRP)
Pursuant to State CEQA Guidelines § 15097, a Mitigation Monitoring and Reporting Program (MMRP) will be adopted to ensure implementation of all mitigation measures identified in this Initial Study MND. The MMRP will specify the mitigation measures, the timing of implementation, the responsible party, and the method of verification.

For future housing projects developed consistent with the Housing Element and within the scope of this IS/MND, compliance with all applicable mitigation measures would be required as a condition of project approval. Project applicants would be responsible for incorporating relevant measures into project plans and for funding or conducting the necessary monitoring, subject to City oversight. The City would verify compliance with the MMRP during the entitlement, permitting, and construction plans, and would impose conditions of approval, permit requirements, or mitigation agreements as necessary to ensure implementation.

1.3 Incorporation by Reference
Pertinent documents relating to this Initial Study have been cited in accordance with State CEQA Guidelines § 15148 or have been incorporated by reference in accordance with State CEQA Guidelines § 15150, which encourages incorporation by reference as a means of reducing redundancy and the length Rialto 6th Cycle HEU
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of environmental reports. The following documents are hereby incorporated by reference into this Initial Study and are available for review at, or can be obtained through, the City of Rialto Planning Division. • City of Rialto. (2010). Rialto General Plan, adopted December 2010. (General Plan) • City of Rialto. (2010). City of Rialto General Plan Update EIR, certified December 2010. (General Plan EIR)
• City of Rialto. (2024). Foothill Central Specific Plan, adopted February 2024. (FCSP) • City of Rialto. (2024). Addendum to the Foothill Boulevard Specific Plan Mitigated Negative Declaration, adopted February 2024.
• City of Rialto. (2012). Lytle Creek Specific Plan, adopted August 2012. (LCSP) • City of Rialto. (2012). Lytle Creek Specific Plan EIR, certified August 2012. (LCSP EIR) • City of Rialto Municipal Code (Municipal Code)

1.4 Environmental Resource Topics
This Initial Study evaluates the proposed Project’s impacts concerning the following environmental resource topics:
• Aesthetics
• Agricultural and Forestry Resources
• Air Quality
• Biological Resources
• Cultural Resources
• Energy
• Geology and Soils
• Greenhouse Gas Emissions
• Hazards and Hazardous Materials
• Hydrology and Water Quality
• Land Use and Planning
• Mineral Resources
• Noise
• Population and Housing
• Public Services
• Recreation
• Transportation
• Tribal Cultural Resources
• Utilities and Service Systems
• Wildfire
• Mandatory Findings of Significance

1.5 Summary of Findings
Section 3.0 contains the Environmental Checklist that was prepared for the proposed Project pursuant to State CEQA Guidelines Appendix G. The Environmental Checklist indicates that the proposed Project would result in no impact or less than significant impact for all resource areas analyzed, except the following for which the Project would result in less than significant impacts with mitigation measure incorporated.
• Biological Resources
• Cultural Resources
• Greenhouse Gas Emissions
• Hazards and Hazardous Materials
• Noise
• Transportation
• Tribal Cultural Resources
Descriptions of the applicable mitigation measures are provided in the environmental analyses for each environmental resource topic. See Section 4.4: Biological Resources, Section 4.5: Cultural Resources, Section 4.7: Greenhouse Gas Emissions, Section 4.9: Hazards and Hazardous Materials, Section 4.13:

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Noise, Section 4.17: Transportation, and Section 4.18: Tribal Cultural Resources for detailed descriptions of the mitigation measures applicable to those topics.

1.6 Initial Study Public Review Process
In accordance with State CEQA Guidelines § 15073 and Assembly Bill 819 (AB 819), the Notice of Intent (NOI) to adopt an MND has been filed with the State Clearinghouse and County of San Bernardino Clerk and distributed to responsible and trustee agencies, other affected agencies, and interested parties.

Pursuant to State CEQA Guidelines § 15206, this IS/MND has been submitted to the State Clearinghouse for a 30-day public review period because the Housing Element Update constitutes a project of statewide, regional, or area-wide significance. Specifically, the Housing Element is required by State law (Government Code § 65580 et seq.) and implements the City’s assigned share of the 6th Cycle RHNA.

In accordance with AB 819, this IS/MND has also been made available on the City’s website for the full 30- day public review period. The document is accessible at:
https://www.rialtoca.gov/633/Plan-to-House-Our-Rialto-Housing-Element.

Hard copies of th is IS/MND are also available for public review at the following location during normal business hours:

City of Rialto
Community Development Department, Planning Division
150 South Palm Avenue
Rialto, CA 92376
During the public review period, affected public agencies and interested members of the public should review and comment on the adequacy of the IS/MND’s environmental analysis and proposed mitigation measures. Written comments may be submitted to:

Sandra Robles, Senior Planner
City of Rialto
Community Development Department, Planning Division
150 South Palm Avenue
Rialto, CA 92376
Email: [email protected]
Email c omments should include the Project title (“6 th Cycle Housing Element Update Project ”) in the subject line and provide a valid mailing address. All comments received during the public review period will be considered prior to adoption of the MND.

1.7 Project Applicant(s)/Sponsor(s)
City of Rialto
150 South Palm Avenue
Rialto, CA 92376

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1.8 Document Organization
This document has been organized into the following sections:

Section 1.0: Introduction describes the purpose , legal context, and organization of the document , including the public review process and applicable CEQA provisions.

Section 2.0: Project Description provides details regarding the Project’s location, environmental setting, background and history, key characteristics, discretionary actions, construction program, phasing, agreements, and required permits and approvals. This section also outlines the intended uses of the Initial Study, including a list of anticipated permits and other approvals.

Section 3.0: Initial Study Checklist includes the Lead Agency’s formal environmental determination and CEQA certification statement.

Section 4.0: Environmental Analysis provides specific analysis for each environmental resource topic, incorporating background information, applicable regulations, thresholds of significance, impact evaluations, and mitigation measures as needed to avoid/ reduce potential impacts to a less than significant level.

Section 5.0: References lists all references and source materials used in the preparation of this Initial Study.

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2.0 Project Description

2.1 Location
The City of Rialto (City) is situated at the southwest portion of the County of San Bernardino (“County”), within the Western San Bernardino Valley. It is bordered by unincorporated County areas to the northeast and southwest, Riverside County to the south, the Cities of Colton and San Bernardino to the east, and the City of Fontana to the west. Interstate 210 (I -210) and Interstate 10 (I -10) provide regional access, traversing the City in an east -west orientation in the northern and southern sections, res pectively.

Exhibit 2-1: Regional Vicinity Map depicts the City’s location in a regional context, while Exhibit 2-2: Local Vicinity Map depicts it in a local context.

This Initial Study evaluates 258 candidate housing sites (parcels) within the City’s boundaries; see Appendix A: Candidate Housing Sites Inventory. Exhibit 2-3: Map of Candidate Housing Sites depicts the Project area, the seven Opportunity Areas (“OA”), and candidate housing site locations. Opportunity Areas are areas within the City where opportunity exists for rezoning to higher -density residential use. For analysis purposes, these candidate housing sites have been assigned numeric labels, as shown on Exhibits 2-4 through 2-12.

Rialto is predominantly residential, with significant commercial areas along Foothill Boulevard (Historic Route 66), Riverside Avenue, Valley Boulevard, and Baseline Road at Riverside Avenue. Additionally, industrial and warehouse uses are concentrated along the City’s rail lines north of I-210 and south of I-10.

2.2 Environmental Setting
Physical Setting
Rialto encompasses approximately 15,424 acres or 24.1 square miles. The City is approximately 4.0 miles wide by 8.5 miles long. 1 It is bordered by unincorporated County areas to the northeast and southwest, Riverside County to the south, the cities of Colton and San Bernardino to the east, and the City of Fontana to the west. The Lytle Creek Wash and Cajon Wash lie north of the City.

Population
This Initial Study uses the most current population data available as of this writing;2 see Table 2-1: County and City Population . As of May 1, 2024, Rialto’s estimated existing population was 103,097 persons, representing approximately 5.0 percent of the County’s total population of 2,181,433 persons. As indicated in Table 2-1, Rialto’s population decreased slightly (by approximately 0.88 percent) from its estimated 2020 population of 104,013 persons. In comparison, the County’s population decline between 2020 and 2024 was slightly less (approximately 0.01 percent).

1 City of Rialto. Available at https://yourrialto.com/488/History -of-Rialto. Accessed on April 3, 2025. 2 The City of Rialto 2021-2029 Housing Element (“Housing Element”) uses 2010 and 2019 data.

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Table 2-1: County and City Population
Jurisdiction 2020 Population 2024 Population Number Change 2020:2024
Percent Change
2020:2024
County 2,181,654 2,181,433 -221 -0.01%
City 104,013 103,097 -916 -0.88%
Source: State of California, Department of Finance. (May 2024). E-5 Population and Housing Estimates for Cities, Counties, and the State - January 1, 2021 -2024. Retrieved from: https://dof.ca.gov/forecasting/demographics/estimates/e -5-population-and-housing-estimates-for- cities-counties-and-the-state-2020-2024/.

Housing
This Initial Study uses the most current housing and household data available as of this writing; see Table 2-2: County and City Households and Housing . As of May 1, 2024, the City’s existing estimated housing stock totaled 28,523 DUs, with single-family detached homes comprising the majority (i.e., approximately 72 percent). As indicated in Table 2-2, the City’s 2024 housing stock increased by approximately 2 percent from the estimated 27,954 DUs in 2020. In comparison, the County’s housing stock increased by approximately 3 percent during the same period.

Table 2-2: County and City Households and Housing
Jurisdiction
Households Housing (DUs)
2020 2024
Number
Change
2020:2024
Percent
Change
2020:2024
2020 2024
Number
Change
2020:2024
Percent
Change
2020:2024
County 2,140,452 2,144,499 +4,047 +0.2% 731,899 753,826 +21,927 +3.0% City 103,552 102,636 -916 -0.9% 27,954 28,523 +569 +2.0% Source: State of California Department of Finance. (May 2024). E-5 Population and Housing Estimates for Cities, Counties, and the State - January 1, 2021- 2024. Retrieved from: https://dof.ca.gov/forecasting/demographics/estimates/e -5-population-and-housing-estimates-for-cities- counties-and-the-state-2020-2024/.

General Plan
The Rialto General Plan (“ General Plan”), adopted in 2010, outlines the City’s long -range planning goals and policies for development. It serves as the City’s vision for growth through 2040. General Plan Chapters 2 through 7 include the following elements: Land Use, Open Space, Community Design , Conservation, Economic Development, Redevelopment, Infrastructure, Public Services and Facilities, Circulation, Safety and Noise, and Housing.

The General Plan Land Use Element describes the City’s existing land use characteristics and development patterns, and it establishes a plan for future development and redevelopment. The candidate housing sites’ existing General Plan land use designations are described in Table 2-3: Candidate Housing Sites - Existing General Plan Land Use Designations.

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Table 2-3: Candidate Housing Sites - Existing General Plan Land Use Designations Land Use Designation Description
R6 - Residential 6
(Density: 2.1-6 du/ac)
Allows development of single-family detached residences with a density of

2.1 to 6 dwelling units per acre (“du/ac”).

R21 - Residential 21
(Density: 12.1-21 du/ac)
Allows development of low-scale attached units with private/shared open space, and groups of attached housing with larger common open space areas with a density of 12.1 to 21 du/ac.

O – Office
(Intensity: maximum 0.75 FAR)
Allows development of small - and large -scale professional offices and related uses to accommodate a broad range of low -intensity, service - oriented, and employment-generating uses.

DMU - Downtown Mixed Use
(Intensity: 6.1- 60 du/ac; maximum

1.50 FAR)
Allows development of single-family attached or detached residences with a density of 22.1 to 30 du/ac.

CC – Community Commercial
(Intensity: maximum 0.35 FAR)
Allows development of variety of retail, office, and service -oriented business activities that serve the local community, including supermarkets, restaurants, small-scale service businesses, and specialty retail stores.

GC – General Commercial
(Intensity: maximum 0.50 FAR)
Allows development of general retail, commercial services, restaurants, lodging, commercial recreation, professional offices, and medical and financial institutions.

BP – Business Park
(Intensity: maximum 1.0 FAR)
Allows development of a mix of commercial, office, research and development, laboratories, and light industrial uses developed in a complementary manner and displaying high-quality architecture and site design.

OSRC – Open Space – Recreation Applies to open space areas set aside for active and passive recreation, including public and private parks of all sizes, sports fields, recreational facilities, plazas, trails, and golf courses.

OSRS -Open Space – Resources Applies to open space areas necessary for the protection and preservation of unique areas for such purposes as groundwater recharge and flood control, habitat and wildlife corridor enhancement, the managed production of aggregate resources, agricultural heritage, transmission of energy resources, and public safety.

SP – Specific Plan Specific plans create and specify the land use designations for the areas that they contain. However, the land use designations must be consistent with the General Plan.

Source: City of Rialto. (2010). City of Rialto General Plan. Pages 2-4 through 2-9. Retrieved from:
https://yourrialto.com/DocumentCenter/View/1494/2010 -General-Plan.

Zoning
The City’s Zoning Code is found in Rialto Municipal Code (“Rialto Code”) Title 18. The Zoning Code’s purpose is to establish permitted land uses and development standards for each zone. It was also adopted to reduce street congestion; ensure safety from fire, panic and other dangers; promote health and general welfare; provide adequate light and air; prevent the overcrowding of land; avoid undue concentration of population; and facilitate the adequate provision of transportation, water, sewerage, schools, parks and other public requirements. The candidate housing sites ’ existing zones are described in Table 2 -4:

Candidate Housing Sites – Existing Zoning.

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Table 2-4: Candidate Housing Sites - Existing Zoning
Zone Description
R-1 A-10,000 Single Family Allows for development of a single one -family dwelling on a minimum 10,000 square foot lot.

R-1 B Single Family Allows for development of a single one -family dwelling on a minimum 8,400 square foot lot.

R-1 C Single Family Allows for development of a single one -family dwelling on a minimum 7,700 square foot lot.

Multi-Family
Allows for development of multiple family attached dwellings of up to four units. Five or more units can be conditionally allowed.

Lots must be a minimum of one acre.

A-P Administrative-Professional-
Institutional
Allows for development of offices for the practice of a profession, administration of a business.

C-1 Neighborhood Commercial Allows for the development of retail stores, offices (business or professional), and certain services.

C-1A Community Shopping Center Allows for the development of uses permitted in C-1 and additional uses.

Foothill Central Specific Plan
Foothill Boulevard Specific Plan: Allows for development of high density residential, residential uses mixed with less -intense commercial uses, and muti -story development to encourage revitalization of existing development.

Central Area Specific Plan: Allows for development of commercial manufacturing or light industrial land uses, commercial uses, and increased density residential uses.

Lytle Creek Ranch Specific Plan
Allows for the development of residential uses with density of 5 - 14 du/ac and for open space, neighborhood parks, golf, and recreation areas.

Renaissance Specific Plan Allows for the development or residential uses with a density of 3- 35 du/ac.

Gateway Specific Plan Allows for the development of retail commercial, office park, and industrial park uses.

Rialto Airport Specific Plan Allows for a range of uses including commercial, office, industrial, and residential uses.

Residential Overlay
Allow for attractive high density residential development in appropriate areas of the City while allowing existing development to remain and retain the development potential of the underlying zoning.

Source: City of Rialto. (2010). City of Rialto Municipal Code Title 18 . Available at https://library.municode.com/ca/rialto/codes/code_of_ordinances?nodeId=TIT18ZO.

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2.3 Background
Housing Element State Law Mandates
California State Housing Element Law, established in 1969 under Government Code Article 10.6, requires all cities and counties to adopt a Housing Element as part of their General Plans . The Housing Element serves as the City’s strategy for addressing current and future housing needs across all income levels. It includes an analysis of demographic and housing trends, an inventory of sites available for residential development, and goals, policies, and programs to facilitate housing production, conserve the e xisting housing stock, and affirmatively further fair housing.

Per Government Code § 65583, local governments must review and update their Housing Elements on an eight-year cycle. Government Code § 65583 further requires that the Housing Element remain internally consistent with the rest of the General Plan and be revised periodically to reflect changing housing conditions, new statutory mandates, and updated RHNA. For jurisdictions within the Southern California Association of Governments (SCAG) region, including the City of Rialto, the State has established the following Housing Element update cycles:
• 5
th Cycle: October 2013 – October 2021
• 6th Cycle: October 2021 – October 2029
• The proposed 6th Cycle HE (the HEU) updates the 5th Cycle Housing Element to incorporate goals, policies, and programs to support housing development throughout the City for the 2021 -2029 planning period.

The City’s 6th Cycle HEU was adopted to comply with these statutory requirements and to demonstrate the City’s ability to accommodate its assigned RHNA obligation of 8,27 2 DUs. Implementation of the Housing Element includes amendments to the General Plan and Zoning Code to rezone sites that are appropriately located and adequately sized to facilitate housing development, particularly for lower - income households, as State law requires.

Failure to comply with Housing Element l aw may result in serious consequences for a local jurisdiction, including exposure to “Builder’s Remedy” projects under Government Code § 65589.5(d), the loss of State housing and infrastructure funding, and potential enforcement actions by the California Attorney General or the California Department of Housing and Community Development (HCD).

Household Income
California state law requires that local jurisdictions plan for the housing needs of all income levels, as defined by HCD. HCD establishes standard income categories based on a percentage of the County’s Median Family Income (MFI), which are used for RHNA allocations and Housing Element planning. These categories include:
• Very Low-Income: 31 and 50 percent of MFI
• Low-Income: 51 percent and 80 percent of MFI
• Moderate Income: 81 percent and 120 percent of MFI
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In addition, state law separately defines extremely low-income households as those earning less than 30 percent of the MFI. Together, the extremely low, very low, and low- income groups are referred to as lower-income households.3
The Department of Housing and Urban Development (HUD) Comprehensive Housing Affordability Strategy (CHAS) estimates, based on the 2013 -2017 American Community Survey, indicate that approximately 44.7 percent of Rialto households earned extremely low, very low, or low incomes, while approximately 55.3 percent of households earned incomes in the moderate to above -moderate range; see Table 2-5: Households by Income Category in Rialto.

Table 2-5: Households by Income Category in Rialto
Income Category (Percent of County MFI) Households Percent Extremely Low (30% MFI or less) 2,920 11.2%
Very Low (30% to 50% MFI) 3,560 13.7%
Low (50% to 80% MFI) 5,140 19.8%
Moderate or Above (Over 80% MFI) 14,395 55.3%
Total 26,015 100%
Source: Department of Housing and Urban Development (HUD) Comprehensive Housing Affordability Strategy (CHAS), 2013 -2017.

Regional Housing Needs Assessment
As previously noted, Government Code § 65583 outlines the specific content requirements of a jurisdiction’s Housing Element. Among these requirements is the obligation for local jurisdictions to provide their “fair share” of regional housing needs. Local governments and Councils of Governments (COGs) must determine existing and future housing needs, and HCD must approve the allocation of these needs.

The City of Rialto is a member agency of SCAG, which is responsible for preparing the RHNA for all jurisdictions within the SCAG region. SCAG acts as the COG for San Bernardino County. State Housing Law mandates the RHNA as part of the periodic process of updating local General Plan Housing Elements. 4 SCAG quantifies the housing need in each jurisdiction for all economic segments of the community, known as RHNA allocation plan, across four income categories: very low, low, moderate, and above moderate.

Per Government Code § 65584(d), the RHNA allocation plan determines existing and projected housing need with the following objectives:
• Increasing the housing supply and the mix of housing types, tenure, and affordability in all cities and counties within the region in an equitable manner, which shall result in each jurisdiction receiving an allocation of units for low- and very low-income households. • Promoting infill development and socioeconomic equity, the protection of environmental and agricultural resources, the encouragement of efficient development patterns, and the achievement of the region’s greenhouse gas reduction targets provided by the State Air Resources Board pursuant to Government Code § 65080.

3 Federal housing and community development programs typically assist households with incomes up to 80 percent of the AMI and use different terminology. For example, the Federal Community Development Block Grant (CDBG) program refers households with incomes between 51 and 80 percent AMI as moderate income (compared to low-income based on State definition). 4 Southern California Association of Governments (SCAG). What is RHNA? Available at https://scag.ca.gov/rhna.

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• Promoting an improved intraregional relationship between jobs and housing, including an improved balance between the number of low -wage jobs and the number of housing units affordable to low-wage workers in each jurisdiction.
• Allocating a lower proportion of housing need to an income category when a jurisdiction already has a disproportionately high share of households in that income category, as compared to the countywide distribution of households in that category from the most recent American Community Survey.
• Affirmatively furthering fair housing.

Each jurisdiction must demonstrate in its Housing Element that it can accommodate its RHNA allocation at all income levels. The California Department of Finance’s (DOF) population estimates and RHNA are also used for regional transportation planning purposes. Senate Bill (SB) 375 integrates RHNA with SCAG’s Regional Transportation Plan (RTP) and Sustainable Communities Strategy (SCS).

Previously, RHNA calculations were conducted independently of the RTP. However, in 2008, the California Legislature passed SB 375 as the land use and transportation planning component of the State’s effort to reduce vehicle miles traveled (VMT) to achieve the Global Warming Solutions Act of 2006 (Assembly Bill [AB] 32) greenhouse gas ( GHG) emission reductions. AB 32 recognizes the importance of planning for housing and land use in creating sustainable communities where residents of all income levels have access to jobs, services, and housing by using transit, walking, or bicycling.

RHNA Allocation
The 6th Cycle RHNA allocates housing needs based on projected growth in housing units over the planning period from 2021 to 2029. The RHNA allocation identifies the number of housing units needed to accommodate estimated future growth at specified levels of affordability. While the length and structure of RHNA cycles are established by state statute (generally 8 years for jurisdictions with a certified Housing Element), HCD sets the specified planning period dates in coordination with regional councils of government. For jurisdictions in the SCAG region, HCD established that the 6 th Cycle RHNA planning period
extends from October 15, 2021, through October 15, 2029. (Note: Northern California regions may follow different cycles based on their respective councils of government.) Table 2-6: RHNA Housing Needs Allocation outlines the City’s regional share of housing units by income category. Rialto’s total housing need for the 6th Cycle is 8,272 DU, comprising 2,218 very low-income units, 1,206 low-income units, 1,371 moderate-income units, and 3,477 above-moderate-income units.

Table 2-6: RHNA Housing Needs Allocation
Income Level % of Average Median Income (AMI) RHNA Allocation (Housing Units)
Very Low Income <50% 2,218
Low-income 50-80% 1,206
Moderate Income 80-120% 1,371
Above Moderate Income >120% 3,477
Total 8,272
Source: SCAG, 2021
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Under State Housing Law, local governments must ensure that projected housing needs can be fully accommodated at all times during the Housing Element planning period. The HEU provides a framework for evaluating the adequacy of local zoning and regulatory actions to ensure each local government designates sufficient land use appropriately throughout the planning period.

The Housing Element must identify and analyze the City’s housing needs , establish reasonable goals, objectives, and policies to address those needs, and implement effective strategies to achieve them .

Additionally, the HEU must identify candidate housing sites with the potential to accommodate housing at higher densities to meet the City’s assigned low -income (extremely low, very low, and low- income) RHNA category needs.

2.4 Project Characteristics
The City is proposing the 6 th Cycle Housing Element (2021–2029 planning period) as a comprehensive update to the City’s 5th Cycle 2014-2021 Housing Element. The HEU includes the City’s Housing Plan, which addresses the City’s identified housing needs. It also outlines goals, policies, and programs related to housing and housing-related services, as well as the City’s approach to addressing its share of the regional housing need.

The HEU has four sections and four appendices:
• Section 1: Introduction summarizes the Housing Element’s content, organization, and statutory considerations.
• Section 2: City of Rialto Community Profile contains an analysis of the City’s population, household and employment base, and housing stock characteristics. • Section 3: Housing Constraints, Resources, and Affirmatively Furthering Fair Housing (AFFH) examines governmental and non-governmental constraints on housing production, maintenance, and affordability, and summarizes housing resources, including identification of housing sites, and funding and financial considerations.
• Section 4: Housing Plan addresses Rialto’s identified housing needs, including housing goals, policies, and programs.
• Appendices:
o Appendix A: Review of Past Performances
o Appendix B: Inventory of Adequate Sites
o Appendix C: Summary of Community Engagement
o Appendix D: Glossary.

Goals and Policies
As required by State Housing Element law, the Housing Plan facilitates and encourages the provision of housing and identifies sites to accommodate RHNA growth needs . The Housing Plan would implement strategies and programs intended to address the City’s housing needs and meet the City’s housing goals, which are:

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• Housing Goal #1 : Maintain and improve the quality of existing housing and neighborhoods in Rialto.
• Housing Goal #2: Promote and encourage housing development that adequately meets the needs of all socioeconomic segments of the community and region. • Housing Goal #3 : Maximize the use of available financial resources and pursue creative and resourceful methods to reduce the overall cost of housing. • Housing Goal #4 : Alleviate any potential governmental constraints to housing production and affordability.
• Housing Goal #5 : Promote equal opportunity for all residents to reside in the housing of their choice.

The goals listed above are described throughout the Housing Plan, along with accompanying policies and programs designed to achieve them. The goals and policies are provided in their entirety in the HEU.

Housing Programs
The housing policy programs proposed to implement each goal and policy are included in their entirety in Housing Element Section 4 - Housing Plan.

Housing Conservation and Improvement
• Housing Program 1A: Acquisition, Rehabilitation, and Resale Program • Housing Program 1B: Funding for Housing Rehabilitation Programs • Housing Program 1C: Code Enforcement
• Housing Program 1D: Multi-Family Improvement Districts • Housing Program 1E: Citywide Homeowner Association Survey • Housing Program 1F: Targeted Neighborhood Approach
• Housing Program 1G: Receivership
Housing Availability and Production
• Housing Program 2A: Provide Adequate Sites to Accommodate the RHNA • Housing Program 2B: Rezone to Provide Adequate Sites to Accommodate RHNA • Housing Program 2C: Replacement Housing
• Housing Program 2D: Accessory Dwelling Unit Construction • Housing Program 2E: Accessory Dwelling Unit Monitoring Program • Housing Program 2F: Non-Vacant Adequate Sites to Satisfy By-Right Requirements of AB 1397 Rialto 6th Cycle HEU
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• Housing Program 2G: Objective Design Standards
• Housing Program 2H: SB 35 Streamlining
• Housing Program 2I: Emergency Shelters
• Housing Program 2J: Transitional and Supportive Housing • Housing Program 2K: Manufactured Housing
• Housing Program 2L: Condominium Conversion
• Housing Program 2M: Single-Room Occupancy (SRO)
• Housing Program 2N: Alternative Housing Concepts
• Housing Program 2O: Lot Consolidation
• Housing Program 2P: Small Lot Consolidation
• Housing Program 2Q: Subdivision of Specific Plan Areas • Housing Program 2R: Residential Incentives
• Housing Program 2S: Surplus Land Act
• Housing Program 2T: Inclusionary Housing Ordinance
• Housing Program 2U: Site Assembly
Housing Affordability
• Housing Program 3A: Down Payment Assistance Program
• Housing Program 3B: Acquisition, Rehabilitation, and Rental Program • Housing Program 3B: Preserve and Monitor At-Risk Units • Housing Program 3C: Mobile Home Park Preservation
• Housing Program 3D: County Homeownership Program
• Housing Program 3E: Good Neighbor Next Door Program
• Housing Program 3F: County Housing Voucher Program
• Housing Program 3G: Tenant-Based Rental Assistance
• Housing Program 3H: Parking Near Public Transit
Removing Governmental Constraints
• Housing Program 4A: Density Bonus
• Housing Program 4B: Remove Development Constraints
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• Housing Program 4C: Water and Sewer Service Providers • Housing Program 4D : Availability of Zoning, Development Standards, Fees and Inclusionary Requirements Online
• Housing Program 4E: Annual Review of Site Requirements • Housing Program 4F: Residential Incentives
• Housing Program 4G: Permit Processing and Findings
Equal Housing Opportunity
• Housing Program 5A: Affirmatively Furthering Fair Housing Services • Housing Program 5B: Fair Housing Services
• Housing Program 5C: Reasonable Accommodations
• Housing Program 5D: Emergency Shelters, Transitional and Supportive Housing • Housing Program 5E: Supportive Housing/Low Barrier Navigation Centers • Housing Program 5F: Housing for Persons with Developmental Disabilities • Housing Program 5G: Agricultural Employee and Farmworker Housing • Housing Program 5H: Residential Care Facilities
Candidate Housing Sites Realistic Development Capacity
To comply with AB 1397, the City must specify the number of DUs that can realistically be accommodated on each candidate housing site and determine whether the site is adequate to accommodate lower- income housing in accordance with existing regulations, or if future implementation actions are necessary.

Table 2-7 shows the City’s 6th Cycle RHNA needs by income category and candidate housing sites to meet those needs. The analysis demonstrates that Rialto has the capacity to meet its 6th Cycle RHNA allocation through the following methods:
• Identification of development capacity on entitled private specific plans • Identification of development capacity on sites that permit development of residential uses at or above 30 du/ac
• Development of approved projects that do not yet have certificates of occupancy • Future development of Accessory Dwelling Units (ADUs) • Identification of opportunity areas for rezoning to higher-density residential use

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Table 2-7: Summary of RHNA Status and Sites Inventory

Very
Low
Income
Low
Income
Moderate
Income
Above
Moderate
Income
Total
RHNA (2021-2029) 2,218 1,206 1,371 3,477 8,272
Pipeline & Units Constructed
Pipeline Projects 0 0 0 916 916
Units Constructed/Issued Permits in
Projection Period
(Begins June 31, 2021)
0 0 0 285 285
Total Pipeline & Units Constructed 0 0 0 1,201 1,201
Remaining Unmet RHNA 2,218 1,206 1,371 2,276 7,071
Existing Zoning
Accessory Dwelling Unit Projection 40 26 6 72
Total Existing Zoning 40 26 6 72
Entitled, Private Specific Plans (SP)
Lytle Creek Ranch Specific Plan 0 621 5,638 6,259
Renaissance Specific Plan 0 405 874 1,279
Total Entitled/Private SPs 1,026 6,512 7,538
Rezone Strategies – Unit Capacity
Opportunity Areas with Rezone/Upzone Programs
1 - Foothill Boulevard Specific Plan 2,443 227 1,767 4,437 2 - North Riverside Avenue 369 40 264 673
3 - Gateway Specific Plan 307 28 223 558
4 - Central Area Specific Plan 189 8 153 350
5 - Baseline Parcels 88 5 70 163
6 - Baseline Shopping Center 744 70 539 1,353
7 – Housing Opportunity Overlay 583 50 420 1,053
Total Rezone Strategies 4,723 428 3,436 8,587
Total Potential Development
Capacity 4,763 1,480 9,954 16,197
Sites Surplus/Shortfall (#) 1,339 109 6,477 7,925
Sites Surplus/Shortfall (%) 39% 8% 186% 96%
Source: City of Rialto. (2025). Plan to House Our Rialto: 2021-2029 Housing Element Update Table B-1: Summary of RHNA Status and Sites Inventory. Available at: https://www.rialtoca.gov/633/Plan -to-House-Our-Rialto-Housing-Element.

As indicated in Table 2 -7, the candidate housing sites and ADU have a realistic development capacity of approximately 16,197 DU, including accessory, entitled Specific Plans, and proposed rezones. This realistic development capacity is based on a realistic development density, which considers previous development patterns and existing development. The realistic development capacity of 16,197 DU shows a 96 percent (7,925 DU) buffer over the City’s RHNA of 8,272 DU. This buffer recognizes that the candidate h ousing sites may not be developed to the greatest density and thus serves as a contingency that may be considered to address future “no net loss,” if it becomes necessary to identify a replacement site during the 6th Cycle. The No Net Loss Law ( Government Code § 65863) aims to ensure development opportunities remain available throughout the planning period to accommodate a jurisdiction’s RHNA, Rialto 6th Cycle HEU
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especially for lower- and moderate-income households. Therefore, the analysis shows that the City can meet its 6th Cycle RHNA.

2.5 Housing Element Implementation Program – CEQA Project State CEQA Guidelines § 15378(a) defines a “project” as “the whole of an action, which has a potential for resulting in either a direct physical change in the environment, or a reasonably foreseeable indirect physical change in the environment.” The HEU does not propose specific housing projects or physical development at this time; instead, it establishes the regulatory framework and zoning capacity necessary to accommodate the City’s RHNA obligations.

The City would meet its RHNA allocation through implementation programs described in HEU Section 4.

Several of these programs involve zoning actions or policy changes that could result in future physical changes to the environment and therefore constitute part of the CEQA “project” evaluated in this Initial Study.

Housing Program 2B: Rezone to Provide Adequate Sites to Accommodate RHNA. To accommodate the RHNA for lower-income and moderate-income households, the City has identified seven OAs, comprising approximately 325 acres and 258 parcels/candidate housing sites, for rezoning; see Exhibit 2-3. A Zoning Code Amendment is proposed to establish a residential overlay that allows up to 50 du/ac on these sites.

In compliance with Government Code § 65583.2(c) and the Clovis decision (Clovis v. County of Fresno, 2022), the City must, and will, establish a minimum density of at least 20 du/ac on sites intended to accommodate lower -income housing. The residential overlay would establish both the minimum (20 du/ac) and maximum (50 du/ac) density limits accordingly.

Housing Program 2D: Accessory Dwelling Unit Construction . Accessory dwelling units (ADUs) are an accepted method of increasing the City’s affordable housing stock . Although the City adopted an ADU ordinance in 2020 and subsequently amended it, additional updates are proposed to ensure full compliance with recent State housing law changes. The City will continue to support and facilitate ADU construction and assumes that at least 128 ADUs will be developed on residential properties throughout the City during the 2021 to 2029.planning period.

Assumed density refers to the realistic buildout capacity of an area based on previous development patterns, market conditions, and existing development. Planned density, on the other hand, refers to the zoning envelope, which is the minimum and maximum allowable densities, without accounting for development constraints or the likelihood of buildout . For candidate housing sites proposed to receive the new residential overlay, the planned density would range from a minimum of 20 du/ac (consistent with Government Code § 65583.2 and the Clovis decision) to a maximum of 50 du/ac.

Table 2-8: Planned/Maximum Development Capacity by Opportunity Area summarizes the upper bound of development capacity for each site, assuming full buildout at the planned maximum density of 50 du/ac. Together, the maximum capacity of the seven OAs is estimated at 16,198 DU , and an additional 128 ADUs are assumed throughout the City, resulting in a total planned development capacity of 16,326 DU. Considering the existing zoning capacity of 2,652 DU on the candidate housing sites, the proposed rezoning would allow for up to 13,674 additional DUs, which constitutes the net increase analyzed in this Initial Study. This increase in housing capacity is forecast to result in approximately 50,320 additional persons; see Response 4.14a.

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Table 2-8: Planned/Maximum Development Capacity by Opportunity Area Opportunity Area (OA)
Number of
Candidate Housing
Sites
Total Acres
(Buildable)
Maximum Allowable
Dwelling Units
1 – Foothill Boulevard Specific Plan 110 160.43 7,992
2 – North Riverside Avenue 15 21.77 1,086
3 – Gateway Specific Plan 2 19.94 997
4 – Central Area Specific Plan 60 12.71 628
5 – Baseline Parcels 10 5.98 296
6 – Baseline Shopping Center 35 56.91 2,836
7 – Housing Opportunity Overlay 26 47.40 2,363
Total OA 258 325.14 16,198
Accessory Dwelling Units (ADU) - - 128
Total OA + ADU 16,326
Existing Development Capacity2 -2,652
Net Development Capacity (CEQA Project) 13,674

2. The City has identified existing residentially -zoned sites. City of Rialto. (2022). City of Rialto 6 th Cycle Housing Element Update (2021 -2029) Initial Study/Mitigated Negative Declaration, Table 2 -7: Summary of RHNA Status and Sites Inventory (Housing Units). Available at:
https://ceqanet.opr.ca.gov/2022010077

2.6 Future Development
Ministerial (By Right) Review
Multiple state laws now require that cities allow by -right (ministerial) residential development under specified conditions. For candidate housing sites included in the City’s Housing Element sites inventory, ministerial approval is required for qualifying projects under Government Code § 65583.2(h) (e.g., projects that provide at least 20 percent of units as affordable to lower-income households and do not involve a subdivision). These projects are exempt from CEQA and are not subject to discretionary review. However, they must comply with applicable zoning and design standards , including Rialto Code Chapter 18.65 :

Precise Plan of Design. Compliance with the applicable mitigation measures identified in this Initial Study would also be required.

In addition to qualifying lower -income housing developments under Government Code § 65583.2(h), other housing categories are allowed ministerially under recent state legislation, including:
• SB 9 (2021): Two-unit residential developments and urban lot splits in single-family zones • SB 684 (2023): Ministerial approval of 10-unit residential subdivisions near transit or in infill areas • SB 2011 (2022): By -right affordable housing development on commercially zoned properties by qualified developers
• Mixed-income projects in commercial corridors, as authorized by various state housing laws These laws provide additional ministerial pathways for residential development outside the scope of traditional RHNA compliance programs. The City’s Housing Element candidate housing sites inventory includes a range of properties that may qualify for one or more of these streamlined approval processes, and is not limited solely to projects meeting the criteria of Government Code § 65583.2(h).

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Discretionary Review
Future development that does not qualify as a use by right under state law as described above would be subject to discretionary review and permitting under the City’s standard entitlement procedures. This includes, but is not limited to, subdivision map approvals, use permits, and design review actions. These projects would also be subject to CEQA review, unless otherwise exempt. Where appropriate, subsequent review may tier from this Initial Study in accordance with State CEQA Guidelines § 15152, provided that the future project is consistent with the assumptions and findings of this analysis.

Precise Plan of Design
Before issuance of a building permit for residential development, a Precise Plan of Design (PPD) must be approved in accordance with Rialto Code Chapter 18.65 . Projects that also require discretionary entitlements (e.g., subdivisions or use permits) or that are not CEQA-exempt shall have their PPD reviewed by the Planning Commission. For ministerial projects that qualify for CEQA exemptions and do not require other discretionary entitlements, the PPD may be reviewed by the Community Development Director as an administrative action.

Subdivision
Residential projects that propose a subdivision would be subject to Rialto Code Title 17 (Subdivisions) and may trigger discretionary review and CEQA compliance unless eligible for a by-right process under SB 9 or similar statutes. Subdivision review procedures will depend on the project type, location, and applicable state housing law.

2.7 Project Phasing
The Housing Element is a policy document that outlines the City’s goals, policies, and programs to accommodate projected housing needs during the 6th Cycle planning period (2021-2029). State law requires that the City demonstrate that it has sufficient zoned capacity (at appropriate densities and by - right allowances) at the time of Housing Element adoption to meet its RHNA. This means that the necessary land use designations and zoning must be in place now, rather than being gradually implemented by 2029.

The forecast growth analyzed in this Initial Study reflects the maximum theoretical development capacity that could result from full buildout of all candidate housing sites identified in the Housing Element sites inventory, totaling up to 16,326 DU, which includes 16,198 DU from candidate housing sites in OAs 1 through 7, and 128 ADUs throughout the City. This number reflects the upper limit of development potential based on zoning and land use designations, including proposed changes, and is used to provide a conservative environmental analysis under CEQA.

Although the zoning capacity must be established now, t he actual rate and pattern of housing construction would occur incrementally over time, influenced by market demand, developer interest, infrastructure capacity, financing availability, and other external factors beyond the City’s control. While this Initial Study assumes full buildout by the end of the planning period (i.e., by 2029) to evaluate a worst- case scenario for environmental impacts, actual development may occur at a slower pace or extend beyond the 6
th Cycle planning period.

To support long -term growth, the City may need to plan for future infrastructure improvements (e.g., water, sewer, transportation) to serve the total potential housing development accommodated by the Rialto 6th Cycle HEU
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Housing Element. However, this Initial Study focuses on the environmental impacts associated with the theoretical full buildout housing development capacity established by the proposed land use and zoning changes, not on a forecast of what will be built by 2029.

2.8 Discretionary Actions, Permits, and Other Project Approvals This Initial Study analyzes and discloses the potential environmental impacts of the Project and the related discretionary actions, in accordance with CEQA. Under State CEQA Guidelines §§ 15050 and 15367, the City of Rialto serves as the Lead Agency and holds primary responsibility for CEQA compliance and project approvals.

Responsible agencies may exercise discretionary approval over certain aspects of the Project (e.g., utility connections, regional transportation improvements). Trustee Agencies are state entities with jurisdiction over natural resources that may be affected by the Project.

As the Lead Agency, the City will take the following legislative and discretionary actions to implement the HEU:

1. General Plan Amendment: The City will amend the Land Use Element of the General Plan to reclassify land use designations of candidate housing sites for consistency with the zoning changes proposed in the Housing Element.

2. Zoning Code Amendment: The City will amend the Rialto Zoning Code to:
a. Apply the Residential Overlay (Rialto Code Chapter 18.116) to the candidate housing sites; b. Establish a minimum residential density of 20 du/ac for candidate housing sites identified to accommodate the lower-income RHNA;
c. Specify that the overlay governs residential development standards where conflicts exist with the base zoning (e.g., minimum density), thereby ensuring compliance with Government Code § 65583.2(c) and the Clovis v. Fresno (2022) decision.

3. Zoning Map Amendment: The City will update its Zoning Map to apply the seven OAs to the candidate housing sites identified in the Housing Element.

Additional Agency Oversight
HCD oversees and certifies the City’s Housing Element under Government Code § 65585. HCD evaluates whether the Housing Element and its implementation programs, including the required rezoning actions, comply with state housing law and fulfill the RHNA assigned to Rialto by SCAG for the 2021-2029 planning period.

City of Rialto
County Boundary
Legend
Regional Vicinity Map
City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
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City of Rialto 6 Cycle Housing Element Update
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Map of Candidate Housing Sites
City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
0 1 20.5
Miles
Legend
City Boundary
5th Cycle Sites
1 – Foothill Boulevard
Specific Plan
2 – North Riverside
A
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3 – Gateway Specific
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4 – Central Area
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5 – Baseline Parcels
6 – Baseline Shopping
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City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
0 630 1,300320
Feet
299299
298298
296296 293293 295295
294294 297 297
Legend
Renaissance Speciﬁc Plan

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City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025.

Legend
5th Cycle Site
Lytle Creek Ranch
Specific Plan
R-1A
th
0 1,000 2,000500
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e Ave
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edar Ave
N Cactus Ave
N Cactus AveW Base Line RdW Base Li ne Rd
S Cactus Ave
W Etiwanda Ave
S Cedar
Ave
W Rialto A ve
W Me rrill A ve
W Foothill Blvd
E 3rd St
N Euc
alyptus
A
ve
N Sycamore Ave
S Eu
calyptus Av
e
E Victoria St
E Holly St
W 2nd St
E South St
E Wilson St
S
Riverside Ave
N
Riv
er
sid
e A
ve
N Willow Ave
S Pepper Ave
N Pepper Ave
N Acacia Av
e
E Rialto Ave
E Base Line Rd
E Mer r ill Ave
S Willow Ave
E Foothill Blvd
North Rialto
Shopping
Center
Downtown
Rialto
Rialto
202
215
209
219 203
204
220
227228210232233
208
216
217206
212
229
236
200 222223214 225218211205
28 35
44 81
1 31
61373374 7545
4656 546355
1113834 8283
84 247
9716
9651032670
105
68 4 95
24 4121 64 87
40 27106 22
25 4923
88 77
89 19
396650 20867 58
7 51
69 7643230
4292
98 4302971
18 400 48401
169
159154
181
126
168
145144
128
134
184 162
178
434
190
176
124
133
185
158
101
417
199
193195
197
15786053 57 4379
1180
104 699 1094
300
Map of Opportunity Area 1 (Foothill Boulevard Specific Plan) City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
0 1,000 2,000500
Feet
W Grove St
W Ramona Dr
N Lilac AveW 3rd St
Holladay Pl
N W
illow A ve
W Foothill Blvd
28 44
81 131
61 32
3736
33 7545 56
429
42 430
297112
400
401
W Grove St
WSS
66 Lorraine Pl
W Foot hill Blvd
82 83
84 2
9716
62 41
18 101
Not to scale.Not to scale.

Coffee
Spectrum
ExtraMile
W
ild
rose
Ave
La ven der Ln
N
Eu
calyptus
Ave
So sa Ln
De Anza Dr
Woo dpi ne Ave
Indig
o
Av
e
De Carm en Dr
San Bernardino Av e
Colton Golf Club
George E Brown
Jr Park
Southern P aci fic RR
10 10
W Valley Blv d
6968
120
121
Map of Opportunity Area 3 (Gateway Specific Plan)
City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
0 400 800200
Feet
Legend
City Boundary
5th Cycle Sites
Opportunity
Area
1 – Foothill Boulevard
Specific Plan
2 – North Riverside
A
venue
3 – Gateway Specific
Plan
4 – Central Area
Specific Plan
5 – Baseline Parcels
6 – Baseline Shopping
Center
7 – Housing Opportunity
Overlay
N Palm A
ve
W 1st St
W 2nd St
S
Palm Ave
W Rialto Ave
S Willow Av
e
N Wi
llow
Ave
Rialto
Burlington Northern and San te Fe Railro ad
S Palm Ave
S
W
ill
ow
Ave
Rialto Station
S Riverside Ave
Trickleside Ln
N Orange Ave
W 1st St
N Date Av
e
N
Oliv e A
ve
S Orange Ave
E 1st St
S O
live Av e
S D
ate Av e
N R
ive
rside
Ave
N Riverside
Ave
S Riverside Av
e
S Riverside Ave
E Rialto AveW Rialto Av e
S Date
Ave
S Olive Ave
S Orange Ave
S R
ive
rside
Ave
S
Rive
rside
Ave
N Sycam
or
e A
ve
E 1st St
S S
ycamo
re Ave
Bur li ngton Nort hern and Sante Fe Ra ilroad
S Sy
camor
e Av
e
170169
159160146
157154
187 167181
126
182174
147
179
168166 165183173
137149 161
164
140
145141142 143144
128134
163184 162
178
177
434
131
136
190189
176
191
138
129
139
124
188
133
186
185
158152132 153
175 180
130
155
125
Map of Opportunity Area 4 (Rialto Central Area Specific Plan) City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
0 180 36090
Feet
Legend
City Boundary
5th Cycle Sites
Opportunity
Area
1 – Foothill Boulevard
Specific Plan
2 – North Riverside
A
venue
3 – Gateway Specific
Plan
4 – Central Area
Specific Plan
5 – Baseline Parcels
6 – Baseline Shopping
Center
7 – Housing Opportunity
Overlay
N O
live Ave
W Ja ckson St
E Wabash St
E Virg inia St
E Mad rona St
W Shamrock St
E Jackson St
N Gardena AveN A
lice Ave
N
Date Ave
E Home St
Eisenhower
High School
Baker's Drive
Thru
Walmart
Neighborhood
Market
Superior
Grocers
Big Lots
McDonald's
Bank of
America
Stater Bros.

E Cascad e Dr
N
Syca
m
oreA
ve
E Mesa Dr
N O
akda
le Ave
E Shamrock St
E Jackson St
N
Joyce AveN
Sage
Ave
N Marcella Ave
E Mar gari ta Rd
E Virg inia St
E Home St
E Maripos a Dr
E Base Line Rd
202
215
209219
203
204220
227228210232233
226
208
216217207206213
212
229
235
236
230 221
234
222223 224214 225231 218211205
198
199
195
Map of Opportunity Areas 5 (Baseline Parcels)
City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
0 300 600150
Feet
Not to scale.

Legend
City Boundary
5th Cycle Sites
Opportunity
Area
1 – Foothill Boulevard
Specific Plan
2 – North Riverside
A
venue
3 – Gateway Specific
Plan
4 – Central Area
Specific Plan
5 – Baseline Parcels
6 – Baseline Shopping
Center
7 – Housing Opportunity
Overlay
N
Fillm
or
e A
ve
N Iri
s
Ave
N
Cact us Av
e
W Walnut Ave
N
Lilac
Av
e
N Ve
rde Av e
N Cact
us A
ve
N Cactus Ave
W Base Line Rd
E Walnu t Ave
E Casc ad e Dr
W Walnut Av e E Walnut Ave
Frisbie Middle
School
N Mill
ar
d Av
e
N Sycamore Ave
E Holly St E Holly St
E Shamrock St E Shamrock St
E Jackson St
E Vir ginia S t
N
Vist
a
Ave
E Home St
N
Riverside AveN Wi
llow A ve
N Acac
ia Ave
W Etiwanda Ave
E Base Line Rd
E Etiwanda Ave
W Base Line Rd
North Rialto
Shopping
Center
Eisenhower
High School
202
215
209219
203
204
220
227228210232233
192
226
208
216217207206213
212
229235 236
230 221
200
234
222223 224214 225231 218211205
198
199
193
194195
196
197
300
Map of Opportunity Area 6 (Baseline Shopping Center)
City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
0 480 960240
Feet
E Mesa Dr
E Base Line Rd
198199
193194195
196197
Not to scale.

Legend
City Boundary
5th Cycle Sites
Opportunity
Area
1 – Foothill Boulevard
Specific Plan
2 – North Riverside
A
venue
3 – Gateway Specific
Plan
4 – Central Area
Specific Plan
5 – Baseline Parcels
6 – Baseline Shopping
Center
7 – Housing Opportunity
Overlay
Map of Opportunity Area 7 (Opportunity Overlay)
City of Rialto 6 Cycle Housing Element Update
Source: San Bernardino County, Cities and Towns, 2023; Ibid, Countywide Parcels, 2025. th
0 730 1,500370
Feet
Legend
City Boundary
5th Cycle Sites
Opportunity
Area
1 – Foothill Boulevard
Specific Plan
2 – North Riverside
A
venue
3 – Gateway Specific
Plan
4 – Central Area
Specific Plan
5 – Baseline Parcels
6 – Baseline Shopping
Center
7 – Housing Opportunity
Overlay
210
Miller Ave
Sie
rr
a AveCitrus A
ve
Arrow B lvd
Merr ill Av e
Foothi ll Blv d Foothil l Blvd
Sierra Lakes
Golf Course
Fontana
Cypress
Elementary
School
210
N River
sid
eAv
e
Ayala
Dr
N Cactus Ave
W Casmalia St
N Willow Ave
Locust Ave
Merr ill Ave
W Rialto Av e W Rialto Ave
Alde
r Ave
W Base Line Rd
N Locust Ave
W Merr ill Ave
E Base Line Rd
W Foothill Blvd
California
Gardens
Terrace West
Rancho West
Downtown
Rialto
San Anselmo
Muscoy
Rialto
N
Ran
cho
Ave
S Willow Ave
Ceda
r
Av
e
Alder Ave
W Highland Ave
W 30t h St
W Mill St
W 5th St
Lytle Creek
Shirrells
Shandin Hills
Carverdale
Delmann
Heights Muscupiabe
Ridgeline
Amtrak
Roosevelt
Blair Park
La Plaza
Valley College
407
118
112114
115
116
202220
227233
192
208
200
234
225218205
28 353774
75 56
5463
111
38 96103
62105
68 4 9524
106 22
25 49
23 88
3920
67 5876432430
71 400
401
159
179
168173
144
134
434124
101
418
417
196
15 57
11 80104
94 410
411
421
300
416
408
405
424
413
415
414
423428426
425
N R
iversi
de Ave
410
409
412
411
Not to scale.

N
Lin
den
Ave
N Maple
Ave
W Summi t Ave
W Via Be
llo D
r
W Persi mmon St
NCe
dar Ave
421 424
420
413
423422428 427426
425
Not to scale.

S Date Ave
E 1st St
E 1st St
S Olive Ave
E Erwin St
S R
iverside Ave S
Sycamore Ave
170169
159
157
168
145
163
434
136
155
Not to scale.

N CedarAve
415
414
Not to scale.

Not to scale.

N
Euca
lyptu
s A
ve
E Vict oria St
E Van Ko eve ring St
N Acacia Ave
E Etiwanda Ave
417
Not to scale.

Page 35 ends

3.0 INITIAL STUDY CHECKLIST
ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED:

The environmental factors checked below would be potentially affected by this Project, involving at least one impact that is a “Potentially Significant Impact” as indicated by the checklist on the following pages.

The analysis concludes that no Potentially Significant Impacts would occur.

Aesthetics Agr icultural Resources Air Quality
Biological Resources Cul tural Resources Energy
Geology / Soils Gre enhouse Gas Emissions Hazards and Hazardous Materials
Hydrology and Water
Quality Land Use Planning Miner al Resources
Noise Pop ulation and Housing Public Services
Recreation Tra nsportation Tribal Cultural Resources
Utilities and Service
Systems Wildfire Mandatory Findings of
Significance
Determination
On the basis of this initial evaluation, the following finding is made:

I find that the proposed Project COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared.

I find that although the proposed Project could have a significant effect on the environment, there will not be a significant effect in this case because revisions in the project have been made by or agreed to by the project proponent. A MITIGATED NEGATIVE DECLARATION will be prepared.

X
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 or a potentially significant unless mitigated impact on the environment, but at least one effect (1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and (2) has been addr essed by mitigation measures based on the earlier analysis as described on attached sheets. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects that remain to be addressed.

I find that although the proposed Project could have a significant effect on the environment, because all potentially significant effects (a) have been analyzed adequately in an earlier IS/MND or NEGATIVE DECLARATION pursuant to applicable standards, and (b) have been avoided or mitigated pursuant to that earlier IS/MND or NEGATIVE DECLARATION, including revisions or mitigation measures that are imposed upon the proposed project, nothing further is required.

CERTIFICATION
Sandra Robles, Senior Planner
(Prepared by)
_____________________________________ _____________________________ Signature Date
10/26/2025
Rialto 6th Cycle HEU
Initial Study/Mitigated Negative Declaration

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Rialto 6th Cycle HEU
Initial Study/Mitigated Negative Declaration

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4.0 Environmental Analysis
This section presents the environmental analysis of the Project, structured in accordance with State CEQA Guidelines Appendix G. The analysis evaluates potential environmental effects across the full range of environmental resource topics, incorporating both qualitative and quantitative assessments to determine whether the Project would result in significant environmental impacts.

Each topic includes an evaluation of potential direct, indirect, short -term (construction), and long -term (operational) impacts, as well as cumulative impacts where applicable. The analysis considers the whole of the Project, including on-site and off-site components and related foreseeable development resulting from the Project’s implementation. For each environmental resource topic, the analysis:
• Identifies the applicable significance thresholds or criteria used to evaluate impacts; • Describes the environmental setting and relevant regulatory context; • Evaluates the nature and extent of potential environmental impacts; • Identifies mitigation measures, if needed, to reduce impacts to a less -than-significant level in compliance with State CEQA Guidelines § 15126.4.

Responses are provided for each checklist question, using the following standard CEQA impact determination categories:
• No Impact. The Project would not result in any measurable environmental impact, or the impact would clearly fall below any threshold of significance. • Less Than Significant Impact. The Project may result in impact s on the environment, but those impacts would not exceed applicable significance thresholds and would not require mitigation. • Less Than Significant With Mitigation Incorporated. The Project has the potential to result in impacts that, without mitigation, would exceed applicable significance thresholds. However, implementation of the identified mitigation measures would reduce those impacts to a level less than significant.
• Potentially Significant Impact. The Project could result in impacts that may exceed applicable thresholds and may cause a significant effect on the environment. Additional environmental analysis or mitigation is necessary to fully evaluate and address these impacts.

For responses identified as “No Impact,” this Initial Study provides appropriate justification based on site conditions, regulatory protections, or supporting technical information. For all other determinations, a rationale and discussion are provided. Where feasible and appropriate, the analysis uses applicable quantitative data, modeling results, or adopted thresholds from the City of Rialto or other responsible or trustee agencies.

Rialto 6th Cycle HEU
Initial Study/Mitigated Negative Declaration

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4.1 AESTHETICS
Environmental Issue
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
Except as provided in Public Resources Code § 21099, Would the project:
a) Have a substantial adverse effect on a scenic vista? X b) Substantially damage scenic resources, including but not limited to trees, rock outcroppings, and historic
buildings within a state scenic highway?
X
c) S ubstantially 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?
X
d) C reate a new source of substantial light or glare,
which would adversely affect day or nighttime views
in the area?
X

IMPACT ANALYSIS

4.1a Would the project have a substantial adverse effect on a scenic vista? Less Than Significant Impact. Scenic vistas can be defined as views or vistas that are generally panoramic in nature and identified as viewpoints or vistas (e.g., formal turnouts along roadways) or as specified in planning documents. A substantial adverse effect on a scenic vista or view would occur where most of an existing public view would be blocked or substantially interrupted. The City’s General Plan Chapter 2 identifies views of the San Gabriel and San Bernardino Mountains and the foothills as scenic vistas. A substantial adverse effect could result in situations where a development project introduces physical features that are not characteristic of current development, obstruct an identified public scenic vista, impair views from other properties, or cause a substantial change to the natural landscape.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HE U. Depending on their location, design, and orientation concerning the identified scenic vistas, future housing development could have a substantial adverse impact on a scenic vista . Future development on candidate housing sites would be subject to project - specific review, including design review. It would be required to comply with the General Plan goals and policies, as well as Rialto Code standards. Future housing developments would be required to adhere to General Plan Community Design Goal 2-15 and Policies 2-15.1 and 2-15.2, which encourage the protection of scenic resources and views, as follows:

Rialto 6th Cycle HEU
Initial Study/Mitigated Negative Declaration

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Policy 2-15.1: Protect views of the San Gabriel and San Bernardino Mountains by ensuring that building heights are consistent with the scale of surrounding, existing development; and Policy 2-15.2: Protect views of the La Loma Hills, Jurupa Hills, Box Spring Mountains, Moreno Valley, and Riverside by ensuring that building heights are consistent with the scale of surrounding, existing development.

Therefore, following compliance with the existing regulatory framework described above, future housing development facilitated by the Project would not have an adverse effect on a scenic vista. Impacts would be less than significant, and no mitigation is required.

4.1b Would the p roject substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a State scenic highway? No Impact. No designated or eligible State scenic highways traverse or are located adjacent to the City.7 Therefore, future housing development facilitated by the Project would not damage scenic resources within a State scenic highway. No impact would occur, and no mitigation is required.

4.1c In non-urbanized areas, would the project substantially degrade the existing visual character or quality of public views of the site and its surroundings? (Public views are those that are experienced from publicly accessible vantage point s.) If the project is in an urbanized area, would the project conflict with applicable zoning and other regulations governing scenic quality?
Less Than Significant Impact. Future housing development facilitated by the Project would be in an urbanized area. As such, impacts would occur if the future housing development conflicted with applicable zoning and other regulations governing scenic quality.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. The City proposes to establish a Residential Overlay Zone on selected properties to permit increased residential density. This overlay constitutes a zoning change and would be codified in the City’s Zoning Code. It would apply to the 258 candidate housing sites, of which 108 are currently vacant, and the remaining 150 sites are already developed with residential, commercial, or other urban land uses. All candidate housing sites are located in urbanized areas of the City, where surrounding land uses already define the visual character. New housing development would occur incrementally and must conform to applicable General Plan policies and zoning regulations that govern visual character, scale, and massing, new density standards, and use allowances.

Future housing development would be required to comply with General Plan Policies 2.14.1 through

2.14.3, which address height, massing, and material compatibility with surrounding development, as well as Rialto Code Chapter 18.61: Design Guidelines, which promote high -quality design and architectural consistency across new development. Compliance with existing height, setback, and zoning regulations would ensure that new development facilitated by the Project does not substantially degrade visual character or conflict with applicable scenic quality regulations. As a result, i mpacts would be less than significant, and no mitigation is required.

7 California Department of Transportation (Caltrans). (2021). California State Scenic Highway System Map. Retrieved from:
https://caltrans.maps.arcgis.com/apps/webappviewer/index.html?id=465dfd3d807c46cc8e8057116f1aacaa. Accessed April 10, 2025.

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Initial Study/Mitigated Negative Declaration

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4.1d 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. Existing outdoor lighting at and near the candidate housing sites is similar to residential lighting found in urbanized areas. Future housing development would generate lighting from two primary sources: lighting from building interiors that would pass through windows, and lighting from exterior sources (e.g., street lighting, parking lot lighting, building illumination, security lighting, and landscape lighting). The introduction of new lighting could adversely affect nighttim e views in the area.

However, future housing development would be required to comply with all applicable City standards related to light and glare, including the California Energy Code.

The California Energy Code contains energy efficiency requirements for new construction and building additions. The California Energy Code requires energy efficiency measures concerning indoor and outdoor lighting performance. These energy requirements aim to prevent excess lighting energy, minimize the potential for excessive light, and thereby reduce spillover. Additionally, future housing development facilitated by the Project would be required to comply with Rialto Code Chapter 18.61, which includes lighting design standards that regulate exterior lighting and prevent light spillage and glare.

Future housing development facilitated by the Project could also add new sources of glare. Glare is commonly associated with reflective surfaces such as glass, rooftop solar panels, windows, heat-reflective roofing materials, and other building elements. As discussed above, future housing development would be required to comply with Rialto Code Chapter 18.61, which would minimize potential glare impacts.

Further, to minimize glare, future projects would be required to use glass with low reflectivity, in compliance with California Building Code Title 24 standards (California Code of Regulations, Title 24) , as adopted by reference in Rialto Code Chapter 15.08. Compliance with these standards would ensure that future housing development facilitated by the Project would not create new sources of substantial light or glare that would adversely affect day or nighttime views . Therefore, impacts would be less than significant, and no mitigation is required.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No standard conditions of approval (“SCA”) or mitigation measures (“MM”) are applicable to the proposed Project.

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Initial Study/Mitigated Negative Declaration

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4.2 AGRICULTURE AND FORESTRY RESOURCES
Environmental Issue
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 D epartment 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?
X
b) Conflict with existing zoning for agricultural use, or a Williamson Act contract?
X
c) Conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public Resources Code §
12220(g)), timberland (as defined by Pub. Res. Code
§ 4526), or timberland zoned Timberland Production
(as defined by Government Code § 51104(g))?
X
d) Result in the loss of forest land or conversion of
forest land to non-forest use?
X
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?
X

IMPACT ANALYSIS

4.2a Would the project c onvert 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 City is predominantly categorized as urban and built -up, and there are no properties within or near the candidate housing sites designated Prime Farmland, Unique Farmland, or Farmland of Statewide Importance, as classified by the State Department of Conservation Farmland Mapping and Rialto 6th Cycle HEU
Initial Study/Mitigated Negative Declaration

Page 42 ends

Monitoring Program (FMMP). 8 Therefore, the Project would not convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance to non-agricultural use or conversion. No impact would occur.

4.2b Would the p roject c onflict with existing zoning for agricultural use, or a Williamson Act contract?
No Impact. There is no existing zoning for agricultural use in the City or property subject to a Williamson Act contract. 9 Therefore, the Project would not conflict with existing zoning for agricultural use or a Williamson Act contract. No impact would occur.

4.2c Would the project conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public Resources Code § 12220(g)), timberland (as defined by Pub. Res. Code § 4526), or timberland zoned Timberland Production (as defined by Government Code § 51104(g))? No Impact. T here is no existing zoning for forest land or timberland in the City. Therefore, Project implementation would not conflict with existing zoning for, or cause rezoning of, forest land or timberland, and no impact would occur.

4.2d Would the project result in the loss of forest land or conversion of forest land to non-forest use? No Impact. There is no forest land located within the City. Therefore, Project implementation would not result in the loss of forest land or conversion of forest land to non-forest use, and no impact would occur.

4.2e 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 land?
No Impact. The City is predominantly urban ized, and there are no Farmlands or forest lands within the City; see Responses 4.2a and 4.2d . Therefore, Project implementation would not cause environmental changes that would result in the conversion of Farmland to non -agricultural use or forest land to non- forest use, and no impact would occur.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA or MM are applicable to the proposed Project.

8 California Department of Conservation, California Important Farmland Finder . https://maps.conservation.ca.gov/DLRP/CIFF/. Accessed April 10, 2025.
9 California Department of Conservation, California Williamson Act Enrollment Finder . https://maps.conservation.ca.gov/dlrp/WilliamsonAct/App/index.html . Accessed April 10, 2025.

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Initial Study/Mitigated Negative Declaration

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4.3 AIR QUALITY
Environmental Issue
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? X
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?
X
c) Expose sensitive receptors to substantial pollutant
concentrations?
X
d) Result in other emissions (such as those leading to
odors) adversely affecting a substantial number of
people?
X

BACKGROUND
SCAQMD Thresholds
The South Coast Air Quality Management District (SCAQMD) CEQA Air Quality Handbook provides significance thresholds for volatile organic compounds (VOC) (also referred to as reactive organic gases [ROG]), nitrogen oxides (NOX), carbon monoxide (CO), sulfur oxides (SO X), particulate matter 10 microns or less in diameter (PM10), and particulate matter 2.5 microns or less in diameter (PM2.5). The thresholds apply to both project construction and operation s within the SCAQMD jurisdictional boundaries. If the SCAQMD thresholds are exceeded, a potentially significant impact could result. However, ultimately, the Lead Agency determines the thresholds of significance for impacts. If a project proposes development in excess of the established thresholds outlined in Table 4.3-1: South Coast Air Quality Management District Significance Thresholds, a significant air quality impact may occur, and additional analysis is warranted to fully assess the significance of impacts.

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Table 4.3-1: South Coast Air Quality Management District Significance Thresholds

Pollutant
Mass Daily Thresholds (pounds per day)
Construction Operations
Nitrogen Oxides (NOX) 100 55
Volatile Organic Compounds (VOC)1 75 55
Particulate Matter up to 10 Microns (PM10) 150 150
Particulate Matter up to 2.5 Microns (PM2.5) 55 55
Sulfur Oxides (SOX) 150 150
Carbon Monoxide (CO) 550 550
Notes:

1. VOCs and reactive organic gases (ROGs) are subsets of organic gases that are emitted from the incomplete combustion of hydroc arbons or other carbon -based fuels. Although they represent slightly different subsets of organic gases, they are used interchangea bly for the purposes of this analysis.

Source: South Coast Air Quality Management District. (2023). South Coast AQMD Air Quality Significance Thresholds . Retrieved from:
https://www.aqmd.gov/docs/default -source/ceqa/handbook/south- coast-aqmd-air-quality-significance-thresholds.pdf?sfvrsn=25. Accessed October 2024.

IMPACT ANALYSIS

4.3a Would the project conflict with or obstruct implementation of the applicable air quality plan? Less Than Significant Impact. As part of its enforcement responsibilities, the U.S. Environmental Protection Agency ( EPA) requires each state with nonattainment areas to prepare and submit a State Implementation Plan (SIP) that demonstrates how it will attain federal standards. The SIP must integrate federal, state, and local plan components and regulations to identify specific measures to reduce pollution in nonattainment areas, using a combination of performance standards and market -based programs.

Similarly, under State law, the California Clean Air Act (CCAA) requires an air quality attainment plan for areas designated as nonattainment with respect to federal and state ambient air quality standards. These plans establish emissions limits and control measures to achieve and maintain these standards by the earliest practical date.

The Project is located within the South Coast Air Basin (SCAB), which is under the jurisdiction of the SCAQMD. According to the Federal Clean Air Act (FCAA), SCAQMD must reduce emissions of criteria pollutants for which the SCAB is in nonattainment. To meet this requirement, SCAQMD prepared the 2016 and 2022 Air Quality Management Plans (AQMPs). The AQMPs establish a program of rules and regulations to reduce air pollutant emissions and achieve compliance with applicable federal and state ambient air quality standards ( i.e., California Ambient Air Quality Standards (CAAQS) and National Ambient Air Quality Standards (NAAQS) ). Preparation of AQMPs involves a regional, multi-agency effort among SCAQMD, the California Air Resources Board ( CARB), SCAG, and the U.S. EPA. The AQMP ’s pollutant control strategies rely on the latest scientific and technical information and planning assumptions, including SCAG’s 2024-2050 Regional Transportation Plan /Sustainable Communities Strategy (“Connect SoCal 2024”),10 updated emission inventory methodologies, and SCAG’s latest growth

10 The latest RTP/SCS (Connect SoCal 2024) was approved by SCAG in April 2024. However, the current AQMP incorporates growth pro jections from the 2020-2024 RTP/SCS (Connect SoCal) and Connect SoCal 2024 is pending approval by the Federal Highway Administration (FHWA) and Federal Transit Administration (FTA).

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forecasts, which were developed in consultation with local governments and reflect local general plans.

The Project is subject to the AQMPs.

The following indicators define criteria for determining consistency with the AQMPs:
• Consistency Criterion No. 1: The Project will not result in an increase in the frequency or severity of existing air quality violations, or cause or contribute to new violations, or delay the timely attainment of air quality standards or the interim emissions reductions specified in the AQMPs. • Consistency Criterion No. 2: The Project will not exceed the assumptions in the AQMPs or increments based on the years of the Project build-out phase.

According to the SCAQMD’s CEQA Air Quality Handbook, the purpose of the consistency finding is to determine if a project would interfere with the region’s ability to comply with CAAQS and NAAQS. 11 The violations referenced in Consistency Criterion No. 1 refer to CAAQS and NAAQS.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. A maximum housing development capacity of 13,674 DUs (including 128 ADUs) is anticipated. This number is based on full buildout of the candidate housing sites at the planned maximum density identified in the HEU and considers the net increase in development capacity above the 2,652 DU currently allowed under existing zoning; see Table 2-8.

With respect to Consistency Criterion No. 1, operations associated with future housing development facilitated by the Project would generate criteria air pollutant emissions from area, energy, and mobile sources; see Responses 4.3b and 4.3c below. However, future housing development would be required to comply with SCAQMD Rules 402, 403, and 1113, which are SCAQMD construction regulations that control and minimize emissions of non- attainment criteria pollutants. Given the nature and scale of the anticipated housing development, SCAQMD thresholds are not anticipated to be exceeded. Therefore, the Project would not conflict with Consistency Criterion No. 1.

With respect to Consistency Criterion No. 2, the AQMP incorporates air pollutant reduction strategies based on SCAG’s latest regional growth forecasts, which are informed by consultation with local governments and references to local general plans. The 2022 AQMP was prepared to accommodate growth, reduce pollutant levels within the areas under SCAQMD jurisdiction, return clean air to the region, and minimize economic impacts. Projects considered consistent with the AQMP would not interfere with attainment, as any growth associated with those projects would have been included in the AQMP’s projections.

In accordance with State Housing Element law, the purpose of the HEU is to facilitate adequate housing development to meet the City’s RHNA allocation, consistent with SCAG’s regional growth forecasts. SCAG assigned the City of Rialto a RHNA of 8,272 DUs for the 6 th Cycle (2021-2029); see Table 2-7: Summary of
RHNA Status and Sites Inventory . While the Project would increase the City’s housing capacity, this increase is necessary to meet RHNA obligations. Additionally, the HEU emphasizes infill and higher-density development near existing jobs and services, which aligns with Connect SoCal 2024 objectives to reduce

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vehicle miles traveled (VMT) and associated emissions . Actual development is expected to occur incrementally and not reach full buildout within the planning period.

Therefore, although the Project would accommodate up to 13,674 additional DU and an associated population increase of approximately 50,320 persons, the growth is consistent with regional planning assumptions and would not exceed growth projections used in the AQMP. The Project would not conflict with implementation of applicable air quality plans. Impacts would be less than significant, and no mitigation is required.

4.3b 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?
The SCAB has been designated as a federal nonattainment area for O 3 and PM 2.5 and a s tate nonattainment area for O 3, PM 10, and PM 2.5. PM 10 and PM 2.5 emissions associated with construction generally result in nearfield impacts. The nonattainment status is the result of cumulative emissions from all sources of these air pollutants and their precursors within the SCAB.

Construction: Less Than Significant Impact. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development facilitated by the Project would be subject to the City’s development review process and would occur as market conditions allow and at the discretion of the individual property owners. Future housing development could result in temporary, short -term pollutants from construction -related soil disturbances, fugitive dust emissions, and combustion pollutants from on-site construction equipment, as well as from off- site trucks hauling construction materials. Emissions resulting from construction would be temporary, and construction activities and associated emissions would cease following completion of the housing development. Furthermore, construction emissions can vary substantially from day to day, depending on the activity level, the specific operation type, and, for dust, prevailing weather conditions.

The SCAQMD’s approach to assessing cumulative impacts is based on the AQMP forecasts of attainment of ambient air quality standards in accordance with the requirements of the FCAA and CCAA. The AQMP is designed to assist the region in attaining the applicable State and national ambient air quality standards and is intended to bring the SCAB into attainment for all criteria pollutants.

All future housing development facilitated by the Project would be subject to the City’s development review process and required to demonstrate compliance with federal, state, and local regulations in effect at the time of development, including the General Plan policies and Rialto Code standards. Future housing development facilitated by the Project would be required to comply with federal, State, and local regulations in effect at the time of development, including SCAQMD Rules 402, 403, and 1113 . Rule 402 requires that air pollutant emissions not be a nuisance to off -site areas. Rule 403 requires that fugitive dust be controlled with Best Available Control Measures so that the presence of such dust does not remain visible beyond the property line of the emission source. Rule 1113 requires contractors to use low -VOC architectural coatings to minimize emissions. Emissions resulting from construction would be temporary, and construction activities and associated emissions would cease following completion of each housing development.

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development facilitated by the Project would generate long -term operational emissions. Operational emissions generated by both stationary and mobile sources would result from normal day -to-day activities. Stationary area source emissions would be generated by space and water heating devices, consumer products , and the operation of landscape maintenance equipment. Energy emissions are associated with building electricity and natural gas. Mobile emissions would be generated by the vehicles traveling to and from potential development and destination sites within the City. Because the SCAB is in nonattainment for O 3, PM 10, and PM 2.5, future housing development facilitated by the Project could contribute to the existing nonattainment status for these pollutants. However, future housing development facilitated by the Project, at a minimum, would be required to meet California Green Building Standards Code (“CALGreen”) and the Energy Code (Title 24, CCR § 6) mandatory energy requirements in effect at the time of the development application, and would benefit from the efficiencies associated with these regulations as they relate to building heating, ventilation, and air conditioning (HVAC), water heating systems, and lighting. Considering these requirements, future housing development facilitated by the Project would not result in a cumulatively considerable net increase of any criteria pollutant for which the SCAB is in nonattainment under an applicable federal or State ambient air quality standard. Therefore, the Project would result in a less than significant impact, and no mitigation is required.

4.3c Would the project expose sensitive receptors to substantial pollutant concentrations? Less Than Significant Impact. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development facilitated by the Project would be located throughout the City, which is an urbanized area, consistent with State housing laws. This future housing is evaluated in this Initial Study at a programmatic level, as discussed above. Future housing development would be assessed on a case-by-case basis. As a result, no air modeling was conducted for this analysis.

Toxic Air Contaminants
Future housing development facilitated by the Project could include emissions of pollutants identified by the State and federal government as toxic air contaminants (TACs) or hazardous air pollutants. State law has established the framework for the state’s TAC identification and control program, which is generally more stringent than the federal program and is aimed at TACs that pose a problem in the state. The greatest potential for TAC emissions during construction would be diesel particulate matter (DPM) emissions from heavy equipment operations and heavy-duty trucks, and the associated health impacts to sensitive receptors. The following measures are required by State law to reduce DPM emissions:
• Fleet owners of mobile construction equipment are subject to the CARB Regulation for in-use off- road diesel vehicles (Title 13, CCR § 2449), the purpose of which is to reduce DPM and criteria pollutant emissions from in-use (existing) off-road diesel-fueled vehicles. • All commercial diesel vehicles are subject to Title 13, CCR § 2485, limiting engine idling time. Idling of heavy-duty diesel construction equipment and trucks during loading and unloading shall be limited to five minutes; electric auxiliary power units should be used whenever possible.

CARB’s Air Quality and Land Use Handbook: A Community Health Perspective recommends against siting sensitive receptors within 500 feet of a freeway, urban roads with 100,000 vehicles per day, or rural roads with 50,000 vehicles per day. The primary concern regarding the adjacency of heavy-traffic roadways is Rialto 6th Cycle HEU
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the long-term impact of TACs, such as diesel exhaust particulates, on sensitive receptors. The primary source of diesel exhaust particulates is heavy-duty trucks on freeways and high-volume arterial roadways.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU . The construction and operation of future housing developments could result in direct impacts through TAC emissions. All future housing developments would be subject to the City’s development review process and would be required to demonstrate consistency with the General Plan policies and Rialto Code standards. This may involve additional studies for future projects near TAC emitters.

Carbon Monoxide Hot Spots
Mobile-source impacts, including those related to CO, would occur essentially on two scales. Regionally, construction travel associated with future housing development would add to regional trip generation and increase VMT within the local airshed and the S CAB. Locally, construction traffic would be added to the roadway system in the vicinity of future housing development sites. There is a potential for the formation of microscale CO “hotspots” to occur immediately around points of congested traffic. Hotspots can form when traffic occurs during periods of poor atmospheric ventilation, characterized by a large number of vehicles cold-started and operating at pollution-inefficient speeds, and/or on roadways already congested with existing traffic.

Typically, high CO concentrations are associated with congested roadways. Traffic associated with future housing development facilitated by the Project could contribute to traffic congestion that could form CO hotspots. Because vehicular emissions continue to improve at a rate faster than vehicle growth and/or congestion, the potential for CO hotspots in the SCAB is steadily decreasing. All future housing development facilitated by the Project would require further evaluation under this criterion through the City’s development review process to demonstrate that both daily construction emissions and operations would not exceed SCAQMD’s significance thresholds for any criteria air pollutant.

As previously discussed, construction activities associated with future housing facilitated by the Project must comply with SCAQMD Rules 402 and 403. Compliance with Rules 402 and 403 would limit fugitive dust (i.e., PM
10 and PM2.5) that may be generated during grading and construction activities. Additionally, future housing developments would also be subject to SCAQMD Rule 113, which requires manufacturers, distributors, and end-users of architectural and industrial maintenance coatings to reduce reactive organic gas (ROG) emissions from the use of these coatings.

Therefore, future housing development facilitated by the Project would not expose sensitive receptors to substantial concentrations of pollutants. Impacts would be less than significant , and no mitigation is required.

4.3d 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 would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU . Future housing development facilitated by the Project could result in odors generated from vehicles and/or equipment exhaust emissions during construction. Odors produced during construction would be attributable to concentrations of unburned hydrocarbons from the tailpipes of construction equipment and architectural Rialto 6th Cycle HEU
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coatings. Such odors would be temporary and generally would occur at magnitudes that would not affect substantial numbers of people.

Land uses and industrial operations associated with odor complaints typically include agricultural uses, wastewater treatment plants, food processing plants, chemical plants, composting, refineries, landfills, dairies, and fiberglass molding. The Project w ould facilitate future housing development, which is not a land use typically associated with generating odors. Therefore, future housing development facilitated by the Project would not expose a substantial number of people to odors. Impacts would be less than significant, and no mitigation is required.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA or MM are applicable to the proposed Project.

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4.4 BIOLOGICAL RESOURCES
Environmental Issue
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 Fis h
and Wildlife or U.S. Fish and Wildlife Service?
X
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 Wildlife or U.S. Fish and Wildlife Service?
X
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?
X
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?
X
e) Conflict with any local policies or ordinances
protecting biological resources, such as a tree
preservation policy or ordinance?
X
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?
X

IMPACT ANALYSIS

4.4a 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 Wildlife or U.S. Fish and Wildlife Service?
Less Than Significant W ith Mitigation Incorporated. The California Department of Fish and Wildlife (CDFW) and the U.S. Fish and Wildlife Service (USFWS) list species as threatened or endangered under the Rialto 6th Cycle HEU
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California Endangered Species Act (CESA) or the Federal Endangered Species Act (FESA), respectively.

Additionally, the USFWS designates critical habitat, which identifies specific areas essential to the conservation of a listed species.

Small pockets of open space exist east of the former Rialto Municipal Airport and south of 7 th Street; however, most of the City’s biological resources are associated with Lytle Creek Wash ,12 which occupies the City’s northern edge. Lytle Creek Wash provides a unique and valuable habitat for diverse plants and wildlife within the following plant communities: Riversidian sage scrub, Riversidian alluvial fan sage scrub, riparian habitat, and ruderal. Additionally, according to San Bernardino County’s Biotic Resources Overlay Maps, the City is within the Burrowing Owl Overlay Zone; therefore, the burrowing owl has a low to moderate potential to occur on candidate housing sites. The burrowing owl is a candidate species for listing under the California Endangered Species Act. Of the 258 candidate housing sites, 108 are currently vacant, and habitat for candidate, sensitive, or special-status species could be present.

It is noted that the potential adverse effects on species identified as a candidate, sensitive, or special - status species, riparian habitats , or other sensitive natural communities, and wetlands from future housing development within the Lytle Creek Ranch Specific Plan (LCRSP) were evaluated in the 2010 LCRSP EIR and found to be less than significant impact with mitigation incorporated .13 As such, these potential impacts are not analyzed in this Initial Study or further discussed.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development on candidate housing s ites with sensitive biological resources could have a n adverse effect on species identified as candidate, sensitive, or special status. Additionally, a potentially significant impact on the burrowing owl could occur if owls are present. Such impacts, if they were to occur, are potentially significant due to the direct reduction in local populations and loss of genetic diversity. In addition, impacts on the burrowing owl could occur if owls were to enter an active construction site. Burrowing owls are known to use manmade materials, such as pipes and culverts, for shelter and nesting. Impacts on the burrowing owl, if they were to inhabit the site subsequently, are potentially significant.

However, future housing development facilitated by the Project wo uld undergo the City’s development review process and may require permits from regulatory agencies, including the CDFW and USFWS. Future housing development would be necessary to comply with the permit processing procedures. F uture housing developments would be required to incorporate MM BIO -1, which stipulates that site -specific surveys be conducted prior to approval to determine if biological resources are present and the extent of any potential impacts . To avoid direct impacts on burrowing owls, pre -construction clearance surveys, buffers, and CDFW consultation, as outlined in MM BIO-2A and MM BIO-2B, would be incorporated. Direct impacts on burrowing owls, if present, would be mitigated to less than significant by the incorporation of MM BIO-2A and MM BIO-2B.

Furthermore, all future housing developments would be required to comply with applicable federal, State, and local requirements concerning potential impacts on biological resources, including plant and wildlife species identified as candidate , sensitive, or special -status, riparian habitats and other sensitive natural

12 City of Rialto. (2010). Rialto General Plan, Chapter 2 (Managing our Land Supply: Land Use, Community Design, Open Space, and Conservation). https://www.rialtoca.gov/DocumentCenter/View/1494/2010- General-Plan. Accessed April 17, 2025. 13 City of Rialto. (2010). Volume I Draft Environmental Impact Report (SCH No. 2009061113) Lytle Creek Ranch Specific Plan, March 2010.

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communities, and jurisdictional waters. Incorporation of mitigation measures would ensure that proper assessment of potential impacts to candidate, sensitive, and special -status species is conducted on a project-by-project basis.

Therefore, following compliance with the existing regulatory framework and incorporation of MM BIO-1, MM BIO -2A, and MM BIO -2B, the Project’s adverse effects on candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the CDFW or USFWS would be mitigated to less than significant.

4.4b 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 Wildlife or U.S. Fish and Wildlife Service? Less Than Significant With Mitigation Incorporated. As previously discussed, most of the City’s biological resources are associated with Lytle Creek Wash, which provides unique and valuable habitat for a diverse collection of plants and wildlife within the following plant communities: Riversidean sage scrub, Riversidean alluvial fan sage scrub, as well as riparian and ruderal habitats. 14 Small pockets of open space
also exist in the City. There are no candidate housing sites within Lytle Creek ; however, 108 vacant candidate housing sites exist, where riparian habitat or other sensitive natural communities may be present.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development could have an adverse effect on riparian habitat or other sensitive natural communities. Where riparian habitat or other sensitive vegetation communities are potentially present on a candidate housing site, future housing development would incorporate MM BIO-1, which requires that site-specific surveys be conducted prior to approval of future developments to determine if biological resources, including riparian habitat or other sensitive vegetation communities, and the extent of any potential impacts. Future housing development facilitated by the Project would be required to adhere to all federal, State, and local requirement s and incorporate MM BIO-1 to avoid and minimize construction and operational impacts on riparian habitats and other sensitive natural communities. Following compliance with the existing regulatory framework and the incorporation of MM BIO -1, future housing development facilitated by the Project would not have a substantial adverse effect, either directly or indirectly, on any sensitive vegetation communities.

Therefore, impacts would be mitigated to less than significant.

4.4c Would the project h ave a substantial adverse effect on state or federally protected wetlands (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means?
Less Than Significant Impact With Mitigation Incorporated. Lytle Creek Wash is located in the City’s northernmost portion. There are no candidate housing sites within Lytle Creek ; however, 108 vacant candidate housing sites exist , some of which may be located in areas with wetlands . Furthermore, the General Plan EIR notes that the City contains no known wetlands; however, due to the presence of major natural drainage areas within the City (i.e., Lytle Creek and the Santa Ana River), there is some potential for wetlands to exist. The Project would not directly construct new housing but would facilitate housing

14City of Rialto. (2023). The City of Rialto General Plan Land Use Element. Retrieved from: 2023 City of Rialto Focused General Plan Update | Rialto, CA. Accessed April 10, 2025.

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development by implementing actions associated with the HEU. Future housing development could have an adverse effect on wetlands. Where wetlands are potentially present on a candidate housing site, future housing development would incorporate MM BIO -1, which requires that site -specific surveys be conducted prior to approval of future developments to determine if biological resources are present and the extent of any potential impacts. With MM BIO -1 incorporated, potential impacts to wetlands would be mitigated to less than significant.

4.4d 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 With Mitigation Incorporated. Although Lytle Creek Wash contains potential habitat for important species, it does not act as a regional wildlife corridor.15 However, it does function as a local (small-scale) corridor for wildlife movement within the creek and the San Bernardino Mountains. None of the candidate housing sites are within the Lytle Creek Wash. Moreover, the candidate housing sites are of limited value for wildlife movement and corridors due to existing surrounding development and infrastructure. Therefore, future housing development facilitated by the Project is not expected to interfere with wildlife corridors.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Of the 258 candidate housing sites, 108 are vacant and could potentially support nesting birds. Although the remaining sites are developed, ornamental landscaping associated with the existing developed sites can also provide habitat for native birds. Future housing development facilitated by the Project could impact nesting birds , which have acclimated to urban life and nest and forage in the local trees and shrubs. These bird species are protected under the Migratory Bird Treaty Act (16 U.S.C. §§ 703 -712). If vegetation clearing were to occur during the bird breeding season (February 1 to July 15 for raptors and January 15 to August 31 for other birds), direct impacts to nesting birds could occur. The loss of any active nests of a native bird during construction would be considered a significant impact. Future housing development would be required to incorporate MM BIO-3, which requires compliance with California Fish and Game Code §§ 3503, 3503.5, and 3513, avoidance of nesting season if feasible, nesting bird surveys three days prior to site disturbance, and buffers around active nests . Therefore, with MM BIO -3 incorporated, future housing development facilitated by the Project would not interfere with the movement of any native resident or migratory fish or wildlife species or impede the use of native wildlife nursery sites. Impacts would be mitigated to a less than significant level.

4.4e Would the project conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance?
Less Than Significant With Mitigation Incorporated. The City does not have a local ordinance protecting biological resources. However, the General Plan include s policies protecting biological resources, as identified above. Additionally, according to San Bernardino County’s Biotic Resources Overlay Maps, Rialto is within the Burrowing Owl Overlay Zone; therefore, the burrowing owl has a low to moderate

15 City of Rialto. (2010). Rialto General Plan, Chapter 2 (Managing our Land Supply: Land Use, Community Design, Open Space, and Conservation). https://www.rialtoca.gov/DocumentCenter/View/1494/2010- General-Plan. Accessed April 17, 2025 Rialto 6th Cycle HEU
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potential to occur on candidate housing sites; see Response 4.4a. Future housing development could occur on a candidate housing site, subject to local policies or ordinances protecting biological resources.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU . Future housing development would be subject to compliance with all General Plan policies intended to protect biological resources, as discussed above and detailed in the General Plan Managing Our Land Supply Element. Compliance would be verified through the project’s entitlement review process. Future housing development facilitated by the Project would be required to incorporate MM BIO -2A, which requires pre-construction clearance surveys for burrowing owls, where appropriate. Therefore, with MM BIO-2A incorporated, the Project would not conflict with any local policies or ordinances protecting biological resources, including the San Bernardino County Biotic Resources Overlay Zones. Impacts would be mitigated to less than significant.

4.4f 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 City is not located within a Habitat Conservation Plan or a Natural Community Conservation Plan.
16 Therefore, no impact would occur, and no mitigation is required.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA are applicable to the proposed Project.

MM BIO-1 Biological Resources Survey. H ousing development facilitated by the Project, in areas where the City has identified a potential presence of sensitive biological resources, shall comply with the following mitigation framework: Prior to any ground-disturbing activity, a qualified biologist shall conduct a site-specific survey of general biological resources. A biological resources report shall be submitted to the City to document the results of the biological resources survey. The report shall inclu de (1) the methods used to determine the presence of sensitive biological resources; (2) vegetation mapping of all vegetation communities and/or land cover types; (3) the locations of any sensitive plant or wildlife species; (4) an evaluation of the potent ial for occurrence of any listed, rare, and narrow endemic species; (5) an evaluation of the significance of any potential direct or indirect impacts from the proposed project ; and (6) recommended mitigation to reduce the impacts to below a level of signif icance. If potentially significant impacts to sensitive biological resources are identified, future project -level grading and site plans shall incorporate project design features to avoid/ minimize direct impacts on sensitive biological resources to the extent feasible. If avoidance is not feasible, additional mitigation measures shall be proposed to reduce impacts to a level that is less than significant.

MM BIO 2A Burrowing Owl Preconstruction Survey s. No less than 14 days prior to any ground - disturbing activities, a qualified biologist shall survey the project site’s construction limits plus a 500-foot buffer for the presence of burrowing owls (BUOW) and occupied nest

16 California Department of Fish and Wildlife. California Natural Community Conservation Plans . Available at https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=68626&inline . Accessed on April 14, 2025.

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burrows. A second survey shall be conducted within 24 hours prior to any ground - disturbing activities. The surveys shall be conducted in accordance with the most current survey methods of the California Department of Fish and Wildlife (CDFW).

If burrowing owls are not observed during the clearance survey, no additional conditions are required to avoid impacts to burrowing owl. A t least one burrowing owl pre - construction survey report shall be submitted to the City to document compliance with this mitigation measure. For the purposes of this measure, ‘qualified biologist’ is a biologist who meets the requirements set forth in the BUOW Guidelines (CDFW 2012).

MM BIO-2B Burrowing Owl Avoidance and Coordination. If burrowing owl is documented on the project site or within 500 feet of the site during either focused surveys or pre-construction surveys, occupied burrowing owl burrows shall not be disturbed. The City and California Department of Fish and Wildlife ( CDFW) shall be contacted within 48 hours of the burrowing owl observation, and a qualified biologist shall set up disturbance avoidance buffers in accordance with CDFW guidance or recommendations.

No work shall occur within avoidance buffers until consultation with CDFW and issuance of permits, if required. If avoidance of burrowing owls is not possible, either directly or indirectly, consultation with CDFW shall be pursued to determine the appropriate course of action. CDFW may require an Incidental Take Permit (ITP) or a Burrowing Owl Relocation and Mitigation Plan. The conditions of the ITP or measures outlined in the Plan shall be adhered to, and any required compensatory mitigation of habitat would be provided. If the burrowing owl is no longer a candidate or listed species under CESA at the time of construction, an ITP would not be required.

MM BIO-3 Nesting Bird Surveys. To ensure compliance with California Fish and Game Code Sections 3503, 3503.5, and 3513 and to avoid potential impacts to nesting birds, vegetation clearing and ground-disturbing activities shall be conducted outside of the bird nesting season (generally February 15 through August 31), if feasible. Regardless of the time of year, a qualified biologist shall conduct a nesting bird survey within three (3) days prior to any disturbance of the site, including but not limited to vegetation clearing, disking, demolition activities, staging, or grading.

If active nests are identified, the biologist shall establish suitable buffers around the nests depending on the level of activity within the buffer and the species observed. Buffer areas shall be avoided until the nests are no longer occupied, and the juvenile birds can survive independently from the nests. During construction activities, the qualified biologist shall continue biological monitoring activities at a frequency recommended by the qualified biologist using their best professional judgment. If nesting birds are documented, avoidance and minimization measures may be adjusted and construction activities stopped or redirected by the qualified biologist to avoid take of nesting birds.

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4.5 CULTURAL RESOURCES
Environmental Issue
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
§15064.5?
X
b) Cause a substantial adverse change in the
significance of an archaeological resource pursuant
to §15064.5?
X
c) Disturb any human remains, including those interred
outside of dedicated cemeteries?
X

IMPACT ANALYSIS

4.5a Would the project cause an adverse change in the significance of a historical resource pursuant to § 15064.5?
Less Than Significant With Mitigation Incorporated. State CEQA Guidelines § 15064.5 defines “historical resources” as resources listed in the California Register of Historical Resources17 (CRHR) or determined to be eligible by the California Historical Resources Commission for listing in the CRHR.18 A resource included in a local register of historical resources, like the City Register, is also presumed to be historically or culturally significant. Generally, a resource is considered to be “historically significant” if the resource meets the criteria for listing on the CRHR ( Pub. Res. Code § 5024.1; Title 14 CCR, § 4852), including the following:
a) Is associated with events that have made a significant contribution to the broad patterns of California’s history and cultural heritage;
b) Is associated with the lives of persons important in our past; c) Embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of an important creative individual, or possesses high artistic values; or d) Has yielded, or may be likely to yield, information important in prehistory or history.

The fact that a resource is not listed in, or determined to be eligible for listing in the CRHR, not included in a local register of historical resources (Pub. Res. Code § 5020.1(k)), or identified in a historical resources survey (Pub. Res. Code § 5024.1(g)) does not preclude the City from determining that the resource may

17 California Office of Historic Preservation. California Register of Historical Resources . Available at: https://ohp.parks.ca.gov/?page_id=21238 .

Accessed June 30, 2025.
18 California Public Resources Code §5020.1(k), §5024.1(g).

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be a historical resource. State CEQA Guidelines § 15064.5 defines a “substantial adverse change in a historical resource” as 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.

The City’s historical or cultural resources, as identified in the City’s General Plan, are listed in Table 4.5-1:

City of Rialto Historical and Cultural Resources. Table 4.5-1 also summarizes the locations of historical resources and any nearby candidate housing sites, based on General Plan information. As indicated in Table 4.5-1, some candidate housing sites are near known historical resources.

Table 4.5-1: City of Rialto Historical and Cultural Resources Resource Location Opportunity Area
Final Christian Church of Rialto* 201 North Riverside Avenue None Grapeland Homesteads and Water
Works (Boundary of Grapeland
Irrigation District)**
Generally, the City’s northwest
portion
Opportunity Area 2:

Renaissance Specific Plan (Site
Nos. 293 through 299)
Agua Mansa Community** Generally, the City’s southern
portion None
National Old Trails Highway (Route 66)** Foothill Boulevard Opportunity Area 1: Foothill
Boulevard Specific Plan (all
sites)
San Bernardino County Museum
(Demolished)**
Northwest Corner of Slover Avenue
and Larch Avenue None
Notes: *National Register of Historic Places; **California Historical Landmarks and Points of Interest Source: City of Rialto. (2010). The City of Rialto General Plan. Retrieved from: https://yourrialto.com/DocumentCenter/View/1 494/2010- General-Plan. Accessed April 14, 2025.

As Project implementation has the potential for development over the next several years, existing buildings or other structures on the candidate housing sites could reach an age of 50 years or older during Project implementation. Generally, structures 50 years of age or older have the potential to be historic resources, based on the National Register of Historic Places 19 (NRHP) guidelines. Structures must have retained their original integrity and context to be considered a historical resource. Any housing site that is presently developed has the potential, however, to contain a historical structure(s) during Project implementation. Of the 258 housing sites, 150 are developed and therefore have the potential to contain a structure that meets the criteria as a historical resource, as determined by the NRHP or the CRHR (50 years or greater), during the future construction of housing units.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. However, as discussed above, a historic structure (≥50 years) could occupy a candidate housing site now or in the future. Therefore, future housing development facilitated by the Project could result in a substantial adverse change to the significance of a historical resource.

Future housing development facilitated by the Project would be subject to the City’s development review process and required to comply with applicable regulations. F uture development would be required to

19 National Park Service. National Register of Historic Places . Available at: https://www.nps.gov/subjects/nationalregister/index.htm . Accessed June 30, 2025.

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comply with applicable federal, State, and local laws that concern the preservation of historical resources, including the National Historic Preservation Act and State CEQA Guidelines.

Further, all future development facilitated by the Project would be subject to compliance with the City’s General Plan Cultural and Historic Resources Element, which includes several policies aimed at historical preservation, including Policy 7 -1.1, which protects the historical resources in Rialto. Additionally, since structures on candidate housing sites could age beyond 50 years during Project implementation, the City may require future housing development on sites with potential historic resources to conduct site-specific evaluation prior to any alteration, demolition, relocation, or new development. Historically significant resources would be identified through site -specific evaluation in conjunction with future development prior to the approval of any development permits. This site -specific evaluation would be used to determine if the proposed development has the potential to impact a significant historical resource or whether the existing development or property is eligible for listing on the NRHP, CRHR, or local listing.

Future housing development on a site with structures aged 50 years or more, having their original structural integrity intact, would be required to incorporate MM CUL-1, which requires the applicant to retain a qualified professional historian to determine whether the affected buildings or structures are historically significant. Following compliance with the established regulatory framework described above, and incorporation of MM CUL -1, the Project’s potential impacts concerning adverse changes in the significance of a historical resource would be mitigated to less than significant.

4.5b Would the project c ause a substantial adverse change in the significance of an archaeological resource pursuant to § 15064.5?
Less Than Significant With Mitigation Incorporated . The 1893- 1894 U.S. Geological Survey ( USGS) topographic map for the Rialto area shows a great many existing structures scattered throughout the City’s downtown area. The lots upon which these structures once were located are now potential historical archaeological sites; thus, the City’s historical town center has a high potential to yield historical archaeological resources, the surrounding areas that were platted later have a moderately high potential, and the remaining areas, to the north and south, have a moderate potential to yield resources. 20 Therefore, future development facilitated by the Project could directly or indirectly impact undiscovered subsurface archaeological resources.

Of the 258 candidate housing sites, 108 are currently vacant/undeveloped. All other candidate housing sites have been graded and developed previously. Undeveloped sites often have a higher potential for unknown archaeological resources, as the likelihood of encountering archaeological resources is greatest on sites that have been minimally excavated in the past (e.g., vacant properties). Previously excavated areas generally have a lower potential for archaeological resources, as the soil containing these resources has been removed or previously disturbed. Any surface and shallow subsurface archaeological deposits at the candidate housing sites have likely been destroyed or heavily disturbed because of previous development.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU . Archaeological resources on the candidate housing sites have likely been destroyed or heavily disturbed because of previous development . Notwithstanding,

20 City of Rialto. City of Rialto General Plan Update Draft Environmental Impact Report , Certified March 2010. See Section 4.5, Cultural Resources, page 113.

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future development facilitated by the Project w ould involve ground-disturbing activities such as grading or excavation that could directly or indirectly impact undiscovered subsurface archaeological resources.

The depth of subsurface excavation would influence whether previously undisturbed areas may be affected. Should archaeological deposits be encountered during project ground disturbance, a n adverse change in the significance of the archaeological resource could occur.

However, future development facilitated by the Project would be subject to compliance with General Plan Policy 7 -3.1, Policy 7- 3.3 and Policy 7- 3.4, which require archaeological surveys in archaeologically sensitive areas, avoidance of impacts to potentially significant archaeological resources, and the reduction of adverse effects to significant archaeological resources that cannot be protected in place through data recovery excavations, respectively.

In addition, SC CUL -1 requires archaeological monitoring in areas of high archaeological sensitivity, as determined by a qualified archaeologist. Further, as a result of Assembly Bill 52 and Senate Bill 18 , tribal consultation with the Yuhaaviatam of San Manuel Nation (YSMN), the City has identified MM CUL-2, MM CUL-3, MM TCR-1, and MM TCR-2 to reduce the potential for adverse effects on archaeological and tribal cultural resources. These measures would ensure that tribal representatives are appropriately engaged in identifying, evaluating, and treating archaeological resources, consistent with State CEQA Guidelines § 15064.5 and the State’s intent under AB 52 to respect tribal sovereignty and cultural heritage.

Following compliance with General Plan policies and standard condition SC CUL -1, and with MM CUL-2 and MM CUL-3 incorporated, potential impacts to archaeological resources would be effectively reduced.

Therefore, the Project’s potential to cause a substantial adverse change in the significance of an archaeological resource would be less than significant with mitigation incorporated.

4.5c Disturb any human remains, including those interred outside of dedicated cemeteries? Less Than Significant Impact. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. As previously noted, cultural resources on the candidate housing sites have likely been destroyed or heavily disturbed because of previous development. Notwithstanding, g round-disturbing activities such as demolition and grading could accidentally discover human remains. In the unlikely event that human remains are found, those remains would require proper treatment in accordance with applicable laws, including Health and Safety Code §§ 7050.5, 7051, and 7054, and Public Resources Code §§ 5097.98 and 5097.99. HSC Health and Safety Code §§7050.5, 7051, and 7054 describe the general provisions for the treatment of human remains. Specifically, Health and Safety Code § 7050.5 outlines the requirements for the treatment of any human remains accidentally discovered during site excavation. Health and Safety Code section HSC §7050.5 also requires that all activities cease immediately and that a qualified archaeologist and a Native American monitor be contacted immediately. T As required by State law, the future devel opment facilitated by the Project would implement the procedures outlined in Public Resources Code § 5087.98, including evaluation by the County Coroner and notification of the Native American Heritage Commission in California ( NAHC) in the unlikely event that Native American human remains are discovered during ground disturbing activities. The NAHC would designate the “Most Likely Descendant ” of the unearthed human remains. If excavation results in the discovery of human remains, future development would halt excavation near the find, and any area reasonably suspected to overlay adjacent remains shall remain undisturbed until the County Coroner has investigated and made appropriate recommendations for the treatment and disposition of the remains. Therefore, following compliance with the established Rialto 6th Cycle HEU
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regulatory framework described above, future development facilitated by the Project would have a less than significant impact concerning human remains, and no mitigation is required.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES SC CUL-121 Archaeological Resources . For development projects or land use plans in areas determined to have a high potential for archaeological resources as determined through field surveys required by General Plan Policy 7-3.1, grading shall be monitored by trained archeological crews workin g under the direction of a qualified professional, so that resources exposed during grading can be recovered and the scientifically important information preserved. Archaeological monitors shall be equipped to recover resources as they are unearthed and to avoid construction delays. Monitors shall be empowered to temporarily halt or divert equipment to allow the removal of abundant or large specimens. Qualified archaeological personnel shall prepare recovered specimens to the point of identification and permanent preservation. Qualified archaeological personnel shall identify and curate specimens into the collections of an appropriate, established, and accredited museum repository with permanent retrievable archaeological storage as determined in consultation with the Community Development Director. Qualified archaeological personnel shall prepare a report of findings with an appendix itemizing specimens subsequent to implementation of curation. A preliminary report shall be submitted to and approved by the Community Development Director before granting of building permits, and a final report shall be submitted to and approved by the Community Development Director before granting of occupancy permits. (General Plan EIR MM C-1.)

MM CUL-1 Historic Resources Evaluation. Prior to issuing a demolition permit or engaging in other ground-disturbing activities on sites containing structures that are more than 50 years old, the City shall determine whether the proposed development could potentially impact historical resources. If a potential impact is identified, the applicant shall retain a qualified professional meeting the Secretary of the Interior’s Professional Qualification Standards for History or Architectural History to prepare a Historic Resource Evaluation Report to determine whether the affected building/structure is historically significant. The evaluation of historic architectural resources shall be based on criteria such as age, location, context, association with an important person or event, uniqueness, or structural integrity, as indicated in State CEQA Guidelines § 15064.5. The applicant shall submit a historical resource report to the City and shall include: (1) the methods used to determine the presence or absence of historical resources; (2) an identification of potential impacts from the proposed project; and (3) an evaluation of the significance of any historical resources identified.

MM CUL-2 Inadvertent Discovery of Cultural or Tribal Cultural Resources. If cultural resources are discovered during ground-disturbing activities, all work within a 60-foot radius of the find shall cease immediately. A qualified archaeologist meeting the Secretary of the Interior’s Professional Qualification Standards shall evaluate the nature and significance of the find.

Work may continue outside the buffered area during this evaluation.

21 Rialto General Plan Environmental Impact Report Mitigation Measure C -1 Rialto 6th Cycle HEU
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If the discovery is determined to be a pre -contact archaeological resource, the Yuhaaviatam of San Manuel Nation Cultural Resources Department (YSMN) shall be notified and invited to participate in the evaluation , as specified in MM TCR-1. The archaeologist shall prepare a Monitoring and Treatment Plan that outlines procedures for avoidance, documentation, and recovery, in coordination with YSMN. A draft of the plan shall be provided to YSMN for review and comment. The plan shall be submitted to the Lead Agency for approval prior to resumption of work within the buffered area.

MM CUL-3 Inadvertent Discovery of Human Remains . If human remains or funerary objects are encountered during any ground-disturbing activities associated with the project, all work within a 100- foot radius of the discovery shall cease immediately. The County Coroner shall be contacted pursuant to Health and Safety Code § 7050.5 to determine the nature and origin of the remains.

If the Coroner determines that the remains are of Native American origin, the Coroner shall notify the Native American Heritage Commission (NAHC) in accordance with Public Resources Code § 5097.98. The NAHC shall identify a Most Likely Descendant (MLD), who shall be afforded the opportunity to make recommendations regarding the treatment or disposition of the remains and any associated grave goods. The project applicant shall coordinate with the MLD and the Yuhaaviatam of San Manuel Nation (YSMN) to ensure that treatment and disposition of the remains are carried out in accordance with the law and tribal preferences, as appropriate.

Work may not resume within the 100 -foot buffer until the remains have been properly removed or protected, and all applicable procedures under state law have been completed.

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4.6 ENERGY
Environmental Issue
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?
X
b) Conflict with or obstruct a state or local plan for
renewable energy or energy efficiency?
X

IMPACT ANALYSIS

4.6a Would the project r esult in a potentially significant environmental impact due to wasteful, inefficient, or unnecessary consumption of energy resources during Project construction or operation?
Construction: Less Than Significant Impact. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Construction activities associated with future housing development facilitated by the Project would consume energy in two general forms: (1) the fuel energy consumed by construction vehicles and equipment; and (2) bound energy in construction materials, such as asphalt, steel, concrete, pipes, and manufactured or processed materials such as lumber and glass.

Fossil fuels are used for construction vehicles and other energy-intensive equipment during site clearing, grading, and construction. Fuel energy consumed during construction would be temporary and would not represent a significant demand for energy resources. In addition, some incidental energy conservation would occur during construction through compliance with State requirements, which specify that equipment not used for more than five minutes must be turned off. Project construction equipment would also be required to comply with the latest U.S. EPA and CARB engine emissions standards, which require highly efficient combustion systems that maximize fuel efficiency and reduce unnecessary fuel consumption. Due to increasing transportation costs and fuel prices, contractors and owners have a strong financial incentive to avoid wasteful, inefficient, and unnecessary energy consumption during construction. There is also growing recognition among developers and retailers that sustainable construction is not prohibitively expensive, and that there is a significant cost -saving potential in green building practices and materials.

Substantial reductions in energy inputs for construction materials can be achieved by selecting building materials composed of recycled materials that require substantially less energy to produce than non- recycled materials. The Project-related incremental increase in the use of energy bound in construction materials such as asphalt, steel, concrete, pipes, and manufactured or processed materials (e.g., lumber and gas) would not substantially increase energy demand compared to overall local and regional demand Rialto 6th Cycle HEU
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for construction materials. It is reasonable to assume that production of building materials such as concrete, steel, etc., would employ all reasonable energy conservation practices in the interest of minimizing the cost of doing business.

Future housing development facilitated by the Project would meet the residents’ varied housing needs.

The majority of future housing development facilitated by the Project would occur on fully improved sites.

Unlike an individual project for which project -specific construction information is available, it is impractical to quantify construction -related energy consumption from all future housing developments that would contribute incrementally to construction energy demand throughout the City. Although construction equipment would primarily use energy in the form of fuel consumption, the amount of construction-related fuel cannot be determined at this time due to the lack of project -specific construction information associated with future development on each of the housing sites. Instead , construction energy consumption would be evaluated for individual future housing development projects through the City’s development review processes. It is noted that construction fuel use is temporary and would cease upon c ompletion of construction activities. Furthermore, there are no unusual Project characteristics that would necessitate the use of construction equipment that is less energy-efficient than at comparable construction sites in the region or State. Therefore, construction fuel consumption associated with future housing development facilitated by the Project would not be any more inefficient, wasteful, or unnecessary than other similar housing developments. A less than significant impact would occur, and no mitigation is required.

During construction, some incidental energy conservation would occur through compliance with State requirements that construction equipment not used for more than five minutes be turned off.

Construction equipment would also be required to comply with the latest U.S. EPA and CARB engine emissions standards. These engines use highly efficient combustion engines to minimize unnecessary fuel consumption. Project-related construction activities would consume energy, primarily in the form of diesel fuel (e.g., mobile construction equipment) and electricity (e.g., power tools).

Future housing development facilitated by the Project, subject to CALGreen regulations, would be required to divert 65 percent of the waste generated during construction from landfills. Recycling construction and demolition waste not only prevents it from being transported to landfills but also reduces the “upstream” energy consumption associated with manufacturing virgin materials.

Future construction activities associated with future housing development would also be required to monitor air quality emissions using applicable regulatory guidance, such as the SCAQMD CEQA Guidelines.

This requirement indirectly relates to construction energy conservation because reducing air pollutant emissions through monitoring and the efficient use of equipment and materials results in lower energy consumption.

As discussed above, there are no unusual characteristics that would necessitate the use of less energy - efficient construction equipment than at comparable construction sites in the region or State. Therefore, it is expected that construction fuel consumption associated with the Project would not be any more inefficient, wasteful, or unnecessary than that of other similar projects of this nature. Therefore, impacts to energy resources associated with the future development’s construction activities would be less than significant, and no mitigation is required.

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Operations: Less Than Significant Impact. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development facilitated by the Project would consume energy during operations through the use of electricity, water, and natural gas in buildings, as well as fuel for on-road vehicles. Passenger vehicles would be powered mainly by gasoline, with some fueled by diesel or electricity. Public transit would be powered by diesel or natural gas and could pot entially be fueled by electricity. Future housing development facilitated by the Project would be subject to the City’s development review process, which requires that development comply with General Plan policies and Rialto Code regulations, as well as any applicable specific plan and its objectives. Future housing development facilitated by the Project would also be required to adhere to all federal, State, and local requirements for energy efficiency, including SB 32’s Scoping Plan, which includes a 50 percent reduction in petroleum use in vehicles, as well as the latest Title 24 standards. It is also noted that future project design and materials would be subject to compliance with the most current Building Energy Efficiency Standards. Future projects would also be required to adhere to the provisions of the California Green Building Standards Code, Title 14 CCR part 11 (CALGreen), which establishes planning and design standards for sustainable site development, energy efficiency (in excess of the Califor nia Energy Code requirements), water conservation, material conservation, and internal air contaminants. Considering these requirements, future housing development facilitated by the Project would not result in a substantial increase in energy use, such that it would result in wasteful, inefficient, or unnecessary consumption of energy resources. Therefore, impacts would be less than significant, and no mitigation is required.

4.6b Would the project conflict with or obstruct a state or local plan for renewable energy or energy efficiency?
Less Than Significant Impact. As discussed in Response 4.5a, the energy conservation policies and plans relevant to the Project include the California Title 24 energy standards and the 2022 CALGreen. F uture housing development facilitated by the Project would be required to comply with these existing energy standards or applicable updated standards. Compliance with State and local energy efficiency standards would ensure that future development facilitated by the Project meets all applicable energy conservation policies and regulations. As such, the Project would n ot conflict with applicable renewable energy or energy efficiency plans. SCAG’s Connect SoCal 2024, adopted in April 2024, integrates transportation, land use, and housing to meet GHG reduction targets set by CARB (Connect SoCal 2024). The document establishes GHG emissions goals for automobiles and light -duty trucks, as well as an overall GHG target for the region, consistent with the target date of AB 32 and the post -2020 GHG reduction goals outlined in SB 375. The Project would not conflict with the stated Connect SoCal 2024 goals. Impacts would be less than significant, and no mitigation is required.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA or MM are applicable to the proposed Project.

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4.7 GEOLOGY AND SOILS
Environmental Issue
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?
X
ii) Strong seismic ground shaking? X
iii) Seismic-related ground failure, including
liquefaction?
X
iv) Landslides? X
b) Result in substantial soil erosion or the loss of
topsoil?
X
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?
X
d) B e 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? X
e) H ave 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?
X
f) Directly or indirectly destroy a unique
paleontological resource or site or unique geologic
feature?
X

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IMPACT ANALYSIS

4.7a Would the project directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury or death involving:
i)
Rupture of a known earthquake fault, as delineated on the most recent Alquist -P riolo
Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault?
L
ess than Significant Impact. The State Alquist-Priolo Earthquake Fault Zoning Act (Act), Pub. Res. Code §§ 2621-2630, was passed in 1972 to mitigate the hazard of fault rupture by prohibiting buildings along active fault lines. Under the Act, cities are required to regulate development within the mapped zones of active earthquake faults. Specifically, cities and counties must establish setback requirements prohibiting the construction of certain structures for human occupancy wit hin 50 feet of an active fault trace. They must also require that structures located within 500 feet of an active fault undergo additional geologic investigations to identify potential hazards and incorporate building design considerations to ensure seismic safety. Finally, cities and counties must notify property owners of any known or suspected fault zones on their property. The California Geologic Survey (CGS) Maps indicate that the San Jacinto Alquist- Priolo Earthquake fault zone traverses the City’s northern portion 22 The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Review of these Maps and the General Plan Safety Element Exhibit 5.4 indicates that candidate housing sites are located near identified fault zones , with some potentially within 500 feet of an active fault. For these sites, housing development facilitated by the Project could cause substantial adverse effects, including the risk of loss, injury , or death involving fault rupture.

Future housing development facilitated by the Project would be subject to the City’s development review process and required to demonstrate compliance with federal, State, and local regulations in effect at the time of development, including General Plan policies and Rialto Code standards. General Plan Policy 5-5.1 requires geotechnical investigations by certified engineer geologists or other qualified professionals for all grading and construction projects subject to geologic hazards, including fault rupture, severe ground shaking, liquefaction, landslides, and collapsible or expansive soils , with particular attention to areas within Alquist -Priolo Earthquake Fault Zones. General Plan Policy 5 -5.2 requires all construction to conform to the California Building Code and be consistent with the Rialto Code, which provides for earthquake-resistant design, excavation, and grading. As previously noted, the Act requires that structures located within 500 feet of an active fault undergo additional geologic investigations to identify potential hazards and inform building design considerations, ensuring seismic safety. Several other laws set requirements and standards for mitigating seismic hazards, including the California Building Standards Code (Title 24 of the California Code of Regulations ), which sets minimum requirements for building design and construction to resist seismic forces. Compliance with the California Building Standards Code requires proper construction of building footings and foundations to withstand the effects of potential ground movement. It also includes provisions to reduce impacts caused by potential major structural failures or loss of life resulting from geologic hazards. The City has adopted the California Building

22 California Geological Survey. (2024). Earthquake Zones of Required Investigation. Retrieved from:
https://maps.conservation.ca.gov/cgs/informationwarehouse/eqzapp/#data_s=id%3AdataSource_4 -191d8e93088-layer-27%3A13680.

Accessed April 2025.

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Standards Code, so any design and construction within Rialto must be consistent with the State building codes. Furthermore, pursuant to the California Disaster Act, Rialto has developed and adopted a hazard mitigation plan to minimize the impact of natural disasters, including earthquakes. Following compliance with the existing regulatory framework described above, future housing development facilitated by the Project implementation would not directly or indirectly cause substantial adverse effects involving rupture of a known earthquake fault. Impacts would be less than significant, and no mitigation is required.

4.7a Would the project directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury, or death involving:
ii) Strong seismic ground shaking?
Less Than Significant Impact. The City is within a seismically active area that could be subject to strong seismic ground shaking , with the highest risks originating from the San Jacinto, San Andreas, and the Cucamonga faults, which have the potential to generate earthquakes of maximum magnitudes ranging from 6.7 to 8.0. 23 Large earthquakes can cause widespread property damage, injury, and loss of life.

Secondary impacts include fires and disruption of utilities and service systems.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development facilitated by the Project would subject people and structures to potential earthquake hazards due to the seismically active nature of Southern California. Therefore, future housing development could cause substantial adverse effects, including the risk of loss, injury, or death, involving strong seismic ground-shaking.

All future housing development facilitated by the Project would be subject to the City’s development review process and required to demonstrate compliance with federal, State, and local regulations in effect at the time of development, including General Plan policies and Rialto Code standards. As discussed above, General Plan Policy 5 -5.1 requires geotechnical investigations by certified engineer geologists or other qualified professionals for all grading and construction projects subject to geologic hazard s, including fault rupture, severe ground shaking, liquefaction, landslides, and collapsible or expansive soils, with particular attention to areas within Alquist-Priolo Earthquake Fault Zones. The City’s existing building plan check and building code compliance procedures include requirements to design structures following the appropriate ground -shaking design parameters outlined in the California Building Code. These parameters are based on the seismic setting and potential intensity levels of the earthqu ake faults most likely to generate significant ground-shaking in the City. Following compliance with the existing regulatory framework, future housing development facilitated by the P roject would not directly or indirectly cause substantial adverse effects involving strong seismic ground shaking . Impacts would be less than significant, and no mitigation is required.

23 City of Rialto. (2023). City of Rialto General Plan Safety Element. Retrieved from: https://www.rialtoca.gov/DocumentCenter/View/4458/2023- Safety-Element?bidId=. Accessed April 14, 2025.

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4.7a Would the project directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury or death involving:
i
ii) Seismic-r
elated ground failure, including liquefaction?
iv
) Landslides?
Less Than Significant Impact. Liquefaction is a geologic phenomenon that causes ground failure in loose, saturated, and sandy-textured soils during strong ground shaking. Seismically induced landslides are a form of slope failure that occurs due to strong ground shaking. The General Plan Safety Element indicates that, in general, liquefaction is unlikely to occur in most areas of Rialto. However, liquefaction is a concern in the Lytle Creek Wash area, where sandy soils and a high water table are present, as well as in areas near the Santa Ana River due to an extremely high water table.24 Although landslides and mudslides can be caused by earthquakes, heavy storms, human activity, or other events that disturb at -risk slopes, Rialto has no recorded history of landslides or liquefaction by the California Geological Survey.
25 It is noted that the potential adverse effects involving liquefaction from future housing development within the Lytle Creek Ranch Specific Plan (LCRSP) were evaluated in the 2010 LCRSP EIR and found to be less than significant with mitigation incorporated. 26 As such, these potential impacts are not analyzed in this Initial Study or further discussed.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. None of the candidate housing sites are located in the Lytle Creek area; however, some sites may be situated in areas where liquefaction is a concern. Future housing development facilitated by the Project could cause substantial adverse effects, including seismic- related ground failure, such as liquefaction. However, liquefaction (and landslide ) potential does not necessarily limit development potential . General Plan Policy 5 -5.1 requires site-specific geotechnical studies to determine the soil properties and specific potential for liquefaction and landslides in a specific area for all grading and construction projects. Furthermore, future development facilitated by the Project would be subject to the City’s development review process and would be required to adhere to all federal, State, and local requirements for avoiding and minimizing seismic -related impacts. Compliance with the California Building Code would require an assessment of hazards related to liquefaction and landslides , and the incorporation of design measures into structures to mitigate these hazards, if development were considered feasible. F ollowing compliance with all relevant regulations for minimizing seismic impacts from development, future development facilitated by the Project would not directly or indirectly cause substantial adverse effects involving seismic-related ground failure, including liquefaction and landslides.

Impacts would be less than significant, and no mitigation is required.

4.7b Would the project result in substantial soil erosion or the loss of topsoil? Less Than Significant Impact. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Therefore, future housing development facilitated by the Project would involve grading activities that could disrupt soil profiles and

24 City of Rialto. (2023). The City of Rialto General Plan Safety and Noise Element. Retrieved from: 2023 City of Rialto Focused General Plan Update | Rialto, CA. Accessed April 10, 2025.
25 Ibid.
26 City of Rialto. (2010). Volume I Draft Environmental Impact Report (SCH No. 2009061113) Lytle Creek Ranch Specific Plan, March 2010.

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soil composition, potentially resulting in increased exposure of soils to wind and rain. Erosion on graded slopes could cause downstream sedimentation impacts. Other related impacts resulting from substantial short-term erosion or loss of topsoil include changes in topography and the creation of impervious surfaces.

Future housing development facilitated by the Project would be subject to the City’s development review process and would be required to comply with General Plan Policy 5 -24, which requires implementation of adequate erosion control measures for development projects to minimize sedimentation damage to drainage facilities. In addition, future housing development facilitated by the Project would be require d to adhere to all federal, State, and local requirements for avoiding and minimizing impacts concerning soil erosion or loss of topsoil , including compliance with the National Pollution Discharge and Elimination System (NPDES) program, which requires implementation of a Storm Water Pollution Prevention Plan (SWPPP) and best management practices (BMPs) intended to reduce soil erosion ; see Response 4. 10a.

Following compliance with the established regulatory framework described above, future housing development facilitated by the Project would not result in substantial soil erosion or loss of topsoil.

Therefore, impacts would be less than significant.

4.7c 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 . Slope stability is affected by the degree of the slope, the slope’s geologic structure, and existing surface and subsurface water. Subsidence occurs when a large portion of land is displaced vertically, usually due to the withdrawal of groundwater, oil, or natural gas. Soils that are particularly subject to subsidence include those with high silt or clay content.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU . According to the USGS, the City experiences land subsidence due to groundwater pumping.27 Future housing development facilitated by the Project would not include further groundwater extraction, which would contribute to regional land subsidence.

Therefore, future housing development facilitated by the Project could be located on a geologic unit or soil that is unstable. However, future housing development facilitated by the Project would be subject to the City’s development review process and applicable federal, State, and local requirements for avoiding and minimizing impacts concerning land failure and unstable soils , including General Plan Policy 5- 5.1, which requires geotechnical investigations by certified engineer geologists or other qualified professionals for all grading and construction projects subject to geologic hazards, including fault rupture, severe ground shaking, liquefaction, landslides, and collapsible or expansive soils. The geotechnical investigation would confirm site -specific soil composition and include conclusions and recommendations addressing grading procedures, soil stabilization, and foundation design. Following compliance with the established regulatory framework, future housing development facilitated by the Project would not create substantial risks to life or property associated with being located on a geologic unit or soil that is unstable or that is likely to become unstable. Impacts would be less than significant, and no mitigation is required.

27 U.S. Geological Survey. (2024). Areas of Land Subsidence in California. Retrieved from: https://ca.water.usgs.gov/land_subsidence/california - subsidence-areas.html. Accessed April 14, 2025.

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4.7d 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? L
ess Than Significant Impact. Most of Rialto is underlain by alluvial units that are composed of granular soils (predominantly sand, gravel, and boulders).28 Such units typically have a low potential for expansion.

However, alluvial units frequently contain lenses or layers of fine -grained soils (silts and clays) that are typically in the moderately expansive range. Such sediments are most likely to be found in the more distal parts of the alluvial fans, away from the San Gabriel and Jurupa Mountains.

Future housing development facilitated by the Project would be subject to compliance with General Plan Policy 5-5.1, which requires geotechnical investigations by certified engineer geologists or other qualified professionals for all grading and construction projects subject to geologic hazards, including expansive soils. Future housing developments would be required to comply with the applicable provisions of the California Building Code regarding soil hazard -related design. The California Building Code sp ecifically requires soil testing in areas likely to have expansive soils. Soil testing would determine the expansive index and include special design and construction provisions for the foundations of structures founded on expansive soils, as necessary. Additionally, Rialto Code § 15.08.020: Building Code , adopts the 2022 California Building Code by reference , which also requires geotechnical investigations that identify potentially unsuitable soil conditions and contain appropriate recommendations for foundation type and design criteria that conform to the analysis and implementation criteria described in Rialto Code Title 15:

Building and Construction. Following compliance with the existing regulatory framework described above, future housing development facilitated by the Project would not pose substantial direct or indirect risks to life or property related to expansive soils. impacts would be less than significant, and no mitigation is required.

4.7e 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. Future housing development facilitated by the Project would be in areas served by the City’s sanitary sewer system . Since sewers would be available for wastewater disposal, future housing developments would not rely on septic tanks or other alternative wastewater disposal systems. Therefore, no impact would occur, and no mitigation is required.

4.7f Would the project directly or indirectly destroy a unique paleontological resource or site , or a unique geologic feature?
Less Than Significant Impact. Previous geologic mapping of Rialto indicates that the City contains surface exposures of several sedimentary rock units, including (from oldest to youngest): older fan deposits of middle to late Pleistocene age , older eolian deposits, younger eolian deposits, younger alluvial fan deposits, younger axial channel deposits, and recent wash deposits. 29 Of these sedimentary units, the

28 City of Rialto. General Plan Update Final Environmental Impact Report State Clearinghouse Number 2008071100 (2010). 29 City of Rialto. General Plan Update Final Environmental Impact Report State Clearinghouse Number 2008071100 (2010).

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Pleistocene sediments mapped at the surface have a high potential to contain significant non-renewable paleontological resources and are therefore assigned a high paleontological sensitivity.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Excavation and other earthmoving activities within surface and subsurface exposures of Pleistocene -era alluvium materials could disturb a unique paleontological resource.30 Although a majority of housing sites are currently developed and disturbed, future construction activities associated with development could affect unidentified paleontological resources through grading and other earthwork activities. Therefore, ground-disturbing activities associated with future housing development facilitated by the Project could directly or indirectly destroy a unique paleontological resource, site, or unique geologic feature, and the impacts could be potentially significant.

Future housing development facilitated by the Project would be subject to the City’s development review process and required to comply with City regulations, including SC GEO-1 through SC GEO-4, which require paleontological field surveys, monitoring, recovery, identification, curation, and the preparation of a report of paleontological findings. Following c ompliance with SC GEO-1 through SC GEO-4, the Project’s potential impacts concerning directly or indirectly destroying a unique paleontological resource would be reduced to less than significant. No mitigation would be required.

STANDARD CONDITIONS OF APPROVAL
31 AND MITIGATION MEASURES
No MM are applicable to the proposed Project.

SC GEO-1 Paleontological Field Surveys . In areas containing middle to late Pleistocene era sediments (Qof) , where it is unknown if paleontological resources exist, field surveys prepared by a qualified paleontological professional before grading shall be conducted to establish the need for paleontological monitoring. Should paleontological monitoring be required after recommendation by the professional paleontologist and approval by the Community Development Director, SC GEO-2 shall be implemented. (General Plan EIR MM C-2)
SC GEO-2 Paleontological Monitoring. A project that requires grading plans and is located in an area of known fossil occurrence or that has been demonstrated to have fossils present in a field survey , as described in SC GEO-1, shall have all grading monitored by trained palaeontologic crews working under the direction of a qualified professional, so that fossils exposed during grading can be recovered and preserved. Palaeontologic monitors shall be equipped to salvage fossils as they are unearthed, to avoid construction delays, and to remove samples of sediments that are likely to contain the remains of small fossil invertebrates and vertebrates. Monitors shall be empowered to temporarily halt or divert equipment to allow removal of abundant or large specimens. Monitoring is not necessary if the potentially fossiliferous units described for the property in question are not present or if present are determined upon exposure and examination by qualified palaeontologic personnel to have low potential to contain fossil resources. Should paleontological resources require recovery, SC GEO-3 shall be implemented. (General Plan EIR MM C-3.)

30 City of Rialto. General Plan Update Final Environmental Impact Report State Clearinghouse Number 2008071100 (2010). Page 121. 31 Rialto General Plan Environmental Impact Report Mitigation Measure s C-2 through C-5 Rialto 6th Cycle HEU
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SC GEO-3 Paleontological Recovery, Identification, and Curation . Qualified paleontological personnel shall prepare recovered specimens to a point of identification and permanent preservation, including washing of sediments to recover small invertebrates and vertebrates. Qualified palaeontologic personnel shall identify and curate specimens into the collections of the Division of Geological Sciences, San Bernardino County Museum, an established, accredited museum repository with permanent , retrievable palaeontologic storage. The paleontologist must have a written repository agreement in hand prior to the initiation of mitigation activities. This measure is not considered complete until curation into an established museum repository has been fully completed an d documented. (General Plan EIR MM C-4.)
SC GEO-4 Paleontological Findings. Qualified palaeontologic personnel shall prepare a report of findings with an appendix itemized of specimens subsequent to implementation of SC CUL-2. A preliminary report shall be submitted to and approved by the Community Development Director before gra nting of building permits , and a final report shall be submitted to and approved by the Community Development Director before granting of occupancy permits. (General Plan EIR MM C-5.)

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4.8 GREENHOUSE GAS EMISSIONS
Environmental Issue
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
Would the project:
a) Generate greenhouse gas emissions, either directly
or indirectly, that may have a significant impact on
the environment?
X

b) Conflict with applicable plan, policy or regulation
adopted for the purpose of reducing the emissions
of greenhouse gases?
X
Background
The “greenhouse effect” is the natural process that retains heat in the troposphere, the bottom layer of the atmosphere. Without the greenhouse effect, thermal energy would “leak” into space, resulting in a much colder and inhospitable planet. With the greenhouse effect, the global average temperature is approximately 61°F (16 °C). Greenhouse gases (GHGs) are the atmospheric components responsible for the greenhouse effect. The amount of heat retained is proportional to the concentration of GHGs in the atmosphere. As more GHGs are released into the atmosphere, GHG concentrations increase and the atmosphere retains more heat, increasing the effects of climate change. Six gases were identified by the Kyoto Protocol for emission reduction targets: carbon dioxide (CO 2), methane (CH4), nitrous oxide (N2O),
hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulfur hexafluoride (SF 6). When accounting for GHGs, all types of GHG emissions are expressed in terms of CO 2 equivalents (CO 2e) and are typically quantified in metric tons (MT) or million metric tons (MMT).

Approximately 80 percent of the total heat stored in the atmosphere is caused by CO2, CH4, and N2O. Both human activities and natural sources emit these three gases. Each GHG affects climate change at different rates and persists in the atmosphere for varying lengths of time. The relative measure of the potential for a GHG to trap heat in the atmosphere is called global warming potential (GWP). The GWP was developed to allow comparisons of the impacts of different gases on global warming. Specifically, it m easures how much energy the emissions of one ton of a gas will absorb over a given period, relative to the emissions of one ton of CO2. The larger the GWP, the more that a given gas warms the Earth compared to CO2 over that period. GWPs provide a common unit of measure, which enables analysts to aggregate emissions estimates of different gases (e.g., to compile a national GHG inventory) and allows policymakers to compare emissions reduction opportunities across sectors and gases.

Greenhouse gases, primarily CO
2, CH4, and N 2O, are directly emitted because of the stationary source combustion of natural gas in equipment such as water heaters, boilers, process heaters, and furnaces.

GHGs are also emitted from mobile sources, such as on- road vehicles and off- road construction equipment, which burn fuels like gasoline, diesel, biodiesel, propane, or natural gas (in compressed or Rialto 6th Cycle HEU
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liquefied form ). Indirect GHG emissions result from electric power generated elsewhere (i.e., power plants) used to operate process equipment, lighting, and utilities at a facility. Included in GHG quantification are electric power, used to pump the water supply (e.g., aqueducts, wells, pipelines), and the disposal and decomposition of municipal waste in landfills.32

IMPACT ANALYSIS

4.8a Would the project g enerate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment?
Less Than Significant With Mitigation Incorporated. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. As discussed in Section 4.14: Population and Housing, the HEU could accommodate up to 13,674 additional DU and an associated population increase of approximately 50,320 persons. These increases in development intensity would result in indirect GHG emissions from both construction activities and long -term and operational sources, such as building energy use, transportation, water consumption, and solid waste generation.

Future housing development facilitated by the Project would be subject to the City’s development review process and would be required to demonstrate consistency with General Plan policies, Rialto Code standards, and other applicable local and State requirements. The SCAQMD has not yet adopted a specific significance threshold for housing development. As previously mentioned, a 3,000 MTCO2e threshold was proposed for non-industrial projects but has not been formally adopted. The increase in GHG emissions from the Project would exceed 3,000 MTCO2e.

A case-by-case review of future housing development would provide flexibility to incorporate the latest analysis methods, technological advancements, mitigation options, and GHG significance thresholds (including using thresholds that meet the latest GHG reduction goals). Future housing development projects would need to demonstrate compliance with the City’s GHG thresholds. MM GHG -1 requires future housing development to conduct a project -level GHG emissions impact assessment and mitigate potentially significant emissions to the extent feasible. A future development project with GHG emissions below SCAQMD thresholds is considered to have a less than significant impact. Future housing development that is allowed “by right” (e.g., without a discretionary action) would be required to submit documentation to the City demonstrating GHG emissions would be less than significant or otherwise have to prepare CEQA documentation. Therefore, with MM GHG-1 incorporated, future housing development facilitated by the Project would not result in GHG emissions that would have a significant impact on the environment. Impacts are less than significant with mitigation incorporated.

4.8b Would the project conflict with an applicable plan, policy, or regulation adopted for the purpose of reducing the emissions of greenhouse gases?
Less Than Significant Impact. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development facilitated by the Project would be subject to compliance with CALGreen and the California Energy Code in effect at the time of construction. These regulations require that new development incorporate design

32 California Air Resources Board. (2022). Climate Change Scoping Plan. Retrieved from: https://ww2.arb.ca.gov/our -work/programs/ab-32- climate-change-scoping-plan/2022-scoping-plan-documents. Accessed April 14, 2025.

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features to capture energy efficiencies associated with energy-efficient building heating, ventilation, and air conditioning mechanical systems, water heating systems, and lighting. In addition, future housing development would be required to adhere to the goals and policies outlined in State plans, such as the 2022 AQMP, as discussed in Section 4.3: Air Quality , and regional plans, including both Connect SoCal 2020 and 2024 (analyzed in Section 4.11: Land Use and Planning).

As addressed in Section 4.11, future housing development facilitated by the Project would be subject to compliance with policies outlined in the General Plan’s Land Use, Community Design, Open Space, and Conservation Element (Chapter 2) that would minimize GHG emissions . Furthermore, future housing development would be required to comply with mandatory energy requirements of CALGreen and the Energy Code in effect at the time of development. Compliance with these regulations would further incorporate design features to capture energy efficiencies associated with building heating, ventilat ion, and air conditioning mechanical systems, water heating systems, and lighting, which ultimately would reduce GHG emissions. Therefore, future development facilitated by the Project would not conflict with an applicable plan, policy, or regulation adopted to reduce emissions of greenhouse gases. Impacts would be less than significant, and no mitigation is required.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA are applicable to the proposed Project.

MM GHG-1: Project-Level Greenhouse Gas Emissions Assessment. Prior to demolition, grading, or building permit approval, and in accordance with South Coast Air Quality Management District (SCAQMD) guidance, a project -specific Greenhouse Gas Emissions Assessment shall be prepared for housing developments facilitated by the Project that would exceed SCAQMD’s recommended threshold of 3,000 MTCO
2e, or any applicable threshold in
effect at the time of development application . If the analysis identifies that project emissions would exceed the applicable threshold, the project shall incorporate feasible mitigation measures to reduce GHG emissions to below the applicable threshold of significance, or as close to that level as feasible, in accordance with CEQA Guidelines § 15126.4(c).

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4.9 HAZARDS AND HAZARDOUS MATERIALS
Environmental Issue
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?
X
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?
X
c) Emit hazardous emissions or handle hazardous or
acutely hazardous materials, substances, or waste
within one-quarter mile of an existing or proposed
school?
X
d) Be located on a site which is included on a list of
hazardous materials sites compiled pursuant to
Government Code § 65962.5 and, as a result, would
it create a significant hazard to the public or the
environment?
X
e) For a project located within an airport land use plan or, where such a plan has not been adopted, within
two miles of a public airport or public use airport,
would the project result in a safety hazard or
excessive noise for people residing or working in the
project area?
X
f) Impair implementation of or physically interfere with an adopted emergency response plan or emergency
evacuation plan?
X
g) Expose people or structures, either directly or
indirectly, to a significant risk of loss, injury or death involving wildland fires?
X

REGULATORY SETTING
Toxic Substances Control Act/Resource Conservation and Recovery Act/Hazardous and Solid Waste Act The federal Toxic Substances Control Act of 1976 and Resource Conservation and Recovery Act (RCRA) established a program administered by the U.S. EPA to regulate the generation, transportation, treatment, storage, and disposal of hazardous waste. The RCRA was amended in 1984 by the Hazardous Rialto 6th Cycle HEU
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and Solid Waste Act, which affirmed and extended the “cradle-to-grave” system of regulating hazardous wastes. Underground Storage Tanks (USTs) are regulated under Subtitle I of RCRA and its regulations, which established construction standards for UST installations installed after December 22, 1988, as well as standards for upgrading existing USTs and associated piping. Since 1998, all non-conforming tanks have been required to be either upgraded or closed.

Emergency Planning and Community Right-to-Know Act
The federal Emergency Planning and Community Right -To-Know Act (EPCRA) was enacted to inform communities and residents of chemical hazards in their area. Businesses are required to report the locations and quantities of chemicals stored on-site to both State and local agencies. EPCRA requires the U.S. EPA to maintain and publish a digital database list of toxic chemical releases and other waste management activities reported by specific industry groups and federal facilities. This database, known as the Toxic Release Inventory, empowers the community to hold companies more accountable for their chemical management.

Hazardous Materials Transportation Act
The U.S. Department of Transportation (DOT) receives authority to regulate the transportation of hazardous materials from the Hazardous Materials Transportation Act (HMTA), as amended and codified (49 U.S.C. § 5101 et seq.). The DOT is the primary regulato ry authority for the interstate transport of hazardous materials and establishes regulations for safe handling procedures (i.e., packaging, marking, labeling, and routing).

The Pipeline and Hazardous Materials Safety Administration was delegated the responsibility to prepare the hazardous material regulations, which are contained in Title 49 of the Code of Federal Regulations (CFR) Parts 100 -180. Title 49 of the CFR, which includes regulations set forth by the HMTA, specifies requirements and regulations related to the transportation of hazardous materials. It required that every employee who transports hazardous materials receive training to recognize and identify hazardous materials and become familiar with hazardous material requirements under the HMTA, the Secretary of Transportation “may authorize any officer employee, or agent to enter upon, inspect, and examine, at reasonable times and in a reasonable manner, the records and properties of persons to the extent such records and properties related to (1) the manufacture, fabrication, marking, maintenance, reconditioning, repair, testing, or distribution of packages or containers for use by any “persons” in the transportation of hazardous materials in commerce; or (2) the transportation or shipment by any “person” of hazardous materials in commerce.”
California Environmental Protection Agency
The California Environmental Protection Agency ( CalEPA) has jurisdiction over hazardous materials and wastes at the State level. The California Department of Toxic Substances Control (DTSC) is the department within CalEPA responsible for implementing and enforcing California’s hazardous waste laws, collectively known as the Hazardous Waste Control Law. DTSC regulates hazardous waste in California primarily under the authority of the federal and the California Health and Safety Code (primarily Division 20, Chapters 6.5 through 10.6, and Title 22, Division 4.5). Although similar to RCRA, the California Hazardous Waste Control Law and its associated regulations define hazardous waste more broadly and regulate a larger number of chemicals. Hazardous wastes regul ated by California but not by the U.S. EPA are called “non -RCRA hazardous wastes .” Other laws that affect hazardous waste are specific to handling, storage, Rialto 6th Cycle HEU
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transportation, disposal, treatment, reduction, cleanup, and emergency planning. Government Code § 65962.5 (commonly referred to as the Cortese List) includes DTSC -listed hazardous waste facilities and sites, Department of Health Services lists contaminated drinking water wells, sites listed by the State Water Resources Control Board ( SWRCB) as having UST leaks and have had a discharge of hazardous wastes or materials into the water or groundwater and lists from local regulatory agencies of sites that have had a known migration of hazardous waste/material.

DTSC directive enforcement is handled at the local level, in this case , the San Bernardino County Department of Environmental Health (DEH). The Regional Water Quality Control Board (RWQCB) also has the authority to implement regulations regarding the management of soil and groundwater investigations.

Hazardous Waste Control Act
The Hazardous Waste Control Act created the State hazardous waste management program, which is similar to but more stringent than the federal RCRA program. The act is implemented by regulations contained in CCR Title 26, which describes the following required aspects for the proper management of hazardous waste: identification and classification; generation and transportation; design and permitting of recycling, treatment, storage, and disposal facilities; treatment standards; operation of facilities and staff training; and closure of facilities and liability requirements. These regulations list over 800 materials that may be hazardous and establish criteria for identifying, packaging, and disposing of such materials .

Under the Hazardous Waste Control Act and Title 26, the generator of hazardous waste must complete a manifest that accompanies the waste from the generator to the transporter to the ultimate disposal location. Copies of the manifest must be filed with the DTSC.

IMPACT ANALYSIS

4.9a 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. Exposure of the public or the environment to hazardous materials can occur through transportation accidents, environmentally unsound disposal methods, improper handling of hazardous materials or hazardous wastes (particularly by untrained personnel), and/or emergencies, such as explosions or fires. The severity of these potential effects varies by the type of activity, concentration, and/or type of hazardous materials or wastes, as well as proximity to sensitive receptors.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. For operations associated with future housing development, hazardous materials would be limited to those commonly found in household fertilizers, pesticides, paint, solvents, and petroleum products. Because these materials would be used in minimal quantities, they are not considered a significant hazard to the public. The proposed Project’s impact on creating signifi cant hazards to the public or the environment through the routine transport, use, or disposal of hazardous materials would be less than significant since all uses and facilities would be required to comply with all applicable federal, State, and regional regulations, which are intended to avoid impacts to the public or environment.

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4.9b 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 With Mitigation Incorporated. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU . Excavation and grading activities associated with future housing development may expose construction workers and the general public to hazardous materials present in soil or groundwater that are unknown . All future housing development on the candidate housing sites in the City would be reviewed to confirm compliance with all applicable requirements, including the City’s development review process, and be subject to compliance with the established regulatory framework for minimizing upset associated with hazardous materials. Compliance with MM HAZ -1, which requires preparation of a project -specific Phase I Environmental Site Assessment (ESA) for any property currently or historically involving hazardous materials or waste, would be required. The Phase I ESA may require further sampling/remedial activities by a qualifie d hazardous materials Environmental Professional with Phase II/site characterization experience. The future developments facilitated by the Project would be required to comply with all applicable federal, State, and local regulations regarding hazardous materials. Following compliance with the established regulatory framework described above and MM HAZ-1, potential impacts involving the accidental discovery of unknown wastes or suspect materials during construction would be mitigated to less than significant.

4.9c Would the project e mit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? Construction: Less Than Significant With Mitigation Incorporated. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development on housing sites facilitated by the Project could have a potentially significant impact on the environment , particularly if it emits hazardous emissions or substances within

0.25 miles of an existing or proposed school. However, as concluded in Response 4.9 b, through compliance with the established regulatory framework, which includes MM HAZ 1, construction activities associated with future housing development on the candidate housing sites would not 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. Further, as concluded in Section 4.3:

Air Quality , through compliance with the established regulatory framework, construction activities associated with future housing development would not expose sensitive receptors to substantial pollutant concentrations or result in other emissions (such as those leading to odors) adversely affecting a substantial number of people.

Therefore, although construction activities associated with future housing development could occur within 0.25 miles of an existing or proposed school, through compliance with the established regulatory framework and incorporation of MM HAZ-1, any potential handling of hazardous or acutely hazardous materials, substances, or waste construction activities would not create a significant hazard to the public or the environment. A less than significant impact would occur with mitigation incorporated.

Operations: Less Than Significant Impact. Operations of future housing development facilitated by the Project would involve the use of small quantities of hazardous materials for cleaning and maintenance purposes, such as paints, household cleaners, fertilizers, and pesticides. No manufacturing, industrial, or Rialto 6th Cycle HEU
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other uses using substantial amounts of hazardous materials would occur as a result of the Project. With proper use and disposal, household maintenance chemicals are not expected to pose a significant hazard to the public or the environment. Additionally, residential uses do not generate hazardous emissions or involve the handling of hazardous materials, substances, or waste in significant quantities that would have an impact on surrounding schools. Therefore, operations associated with future housing devel opment facilitated by the Project would not emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school, and a less than significant impact would occur.

4.9d Would the project b e located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code § 65962.5 and, as a result, would it create a significant hazard to the public or the environment?
Less Than Significant With Mitigation Incorporated. Government Code § 65962.5 (commonly referred to as the Cortese List) includes Department of Toxic Substances Control ( DTSC) listed hazardous waste facilities and sites, Department of Health Services lists of contaminated drinking water wells, sites listed by the State Water Resources Control Board as having underground storage tank leaks and having had a discharge of hazardous wastes or materials into the water or groundwater, and lists from local regulatory agencies of sites that have had a known migration of hazardous waste/material.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. F uture housing development facilitated by the Project would be evaluated using appropriate databases , including the California DTSC database that, pursuant to Government Code § 65962.5, lists Federal Superfund, State Response, Voluntary Cleanup, School Cleanup, Hazardous Waste Permit, and Hazardous Waste Corrective Action sites. The potential to create a significant hazard to the public or the environment would be assessed at the time the projects are proposed. Compliance with MM HAZ -1, which requires preparation of a project -specific Phase I Environmental Site Assessment (ESA) for any property currently or historically involving hazardous materials or waste, would be required. With MM HAZ-1 incorporated, future development facilitated by the Project would not create a significant hazard to the public or the environment in this regard. Impacts would be mitigated to less than significant.

4.9e For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard or excessive noise for people residing or working in the Project area? No Impact. Rialto is not located within an airport land use plan or within two miles of a public airport, public use airport, or private airstrip. The Rialto Airport, previously known as Miro Field, was closed in 2014. Therefore, future housing development facilitated by the Project would not result in a safety hazard or excessive noise associated with airport operations; no impact would occur.

4.9f Would the project i mpair implementation of an emergency response plan or emergency evacuation plan?
Less Than Significant Impact. The City’s Emergency Operations Plan (EOP) (also referred to as the SEMS Multi-Hazard Functional Plan) provides guidance for the City’s response to emergencies associated with Rialto 6th Cycle HEU
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natural disasters and technological incidents. 33 The EOP provides an overview of operational concepts, identifies components of the City’s emergency management organization within both the Standardized Emergency Management System (SEMS) and the National Incident Management System (NIMS) , and describes the overall responsibilities of the federal, state, and county entities and the City for protecting life and property and assuring the overall well-being of the population.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future development facilitated by the Project would increase housing density in some regions of the City, resulting in greater population concentrations within certain areas. However, the Project would not result in changes to the City’s existing circulation network.

No land uses are proposed that would impair the implementation of, or physically conflict with, the City’s EOP. The City would continue to comply with EOP requirements. Therefore, the Project would not conflict with any State or local plan aimed at preserving and maintaining adopted emergency response or emergency evacuation plans. Impacts would be less than significant, and no mitigation is required.

4.9g 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. As discussed in Section 4.20: Wildfire, none of the candidate housing sites are located within a Very High Fire Hazard Severity Zone, as mapped by the California Department of Forestry and Fire Protection (CAL FIRE) within a Local Responsibility Area (LRA). However, candidate housing sites 409 through 412 are within a High Fire Hazard Severity Zone, and a portion of 413 is within a Moderate Fire Hazard Severity Zone in an LRA, based on CAL FIRE’s most recent draft LRA Fire Hazard Severity Zone maps.
34 Despite being mapped within high and moderate Fire Hazard Severity Zones, these candidate housing sites are located in developed areas with existing infrastructure, adjacent development, and readily available emergency services, rather than areas characterized by wildland vegetation or the wildland - urban interface. Moreover, future housing development facilitated by the Project would be subject to the City’s development review process and the California Fire Code as adopted in Rialto Code Chapter 15.28, which includes requirements for fire -resistant building materials and construction methods; emergency vehicle access and evacuation standards; fire suppression infrastructure; and vegetation management or defensible space where applicable. Compliance with these regulations would reduce the potential risk of wildfire-related exposure for future residents or structures. Therefore, while a few candidate sites are located in mapped high or moderate Fire Hazard Severity Zones, the Project would not expose people or structures, either directly or indirectly, to a significant risk of loss, injury, or death involving wildland fires, and impacts would be less than significant.

STANDARD CONDITIONS STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA are applicable to the proposed Project.

33 City of Rialto. SEMS/NIMS Multi -Hazard Functional Plan. Retrieved from: https://www.rialtoca.gov/DocumentCenter/View/943/Emergency - Operations-Plan-PDF. Accessed April 14, 2025.
34 California Department of Forestry and Fire Protection. “Fire Hazard Severity Zones.” Office of the State Fire Marshal , Community Wildfire Preparedness and Mitigation. Available at: https://osfm.fire.ca.gov/what -we-do/community-wildfire-preparedness-and-mitigation/fire-hazard- severity-zones. Accessed July 1, 2025.

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MM HAZ-1 Phase I Environmental Site Assessment. Future housing development facilitated by the Project, on a site where the City has determined potential for risk of upset and accident conditions involving the release of hazardous materials into the environment, shall be subject to the following requirements prior to the issuance of grading permits:
1) Preliminary Site Screening. The project applicant shall conduct a Phase I Environmental Site Assessment (ESA) or an equivalent preliminary environmental assessment to determine whether the project site or immediately adjacent properties have a history of hazardous material use or contamination. If evidence of contamination is found , the report shall characterize the type, location, and potential extent of contamination , and recommend whether additional sampling or remediation is warranted prior to site disturbance.
2) Additional Investigation and Remediation, If Needed. If contamination is identified on the project site, the City, in coordination with the appropriate regulatory agencies (e.g., the San Bernardino County Department of Environmental Health Services or the Regional Water Quality Control Board) , shall determine whether further site investigation (e.g., Phase II ESA) or remediation is necessary. If required, the project applicant shall be responsible for preparing and implementing an agency -approved investigation or remediation plan prior to initiation of construction activities. 3) Completion of Remediation. If the applicable oversight agency requires remediation, it shall be completed in compliance with all applicable regulatory standards and guidance, and to a level that reduces risk to below the applicable thresholds. Remediation shall be completed prior to issuance of any building or occupancy permits for the affected site.
4) Documentation of Completion. Closure reports, no further action (NFA) letters, or other documentation acceptable to the San Bernardino County Department of Environmental Health Services or other applicable oversight agency shall be submitted to the City for review and approv al prior to the issuance of grading permits. No construction shall occur in the affected area until the City accepts such documentation.

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4.10 HYDROLOGY AND WATER QUALITY
Environmental Issue
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 groundwater quality?
X
b) Substantially decrease groundwater supplies or
interfere substantially with groundwater recharge
such that the project may impede sustainable
groundwater management of the basin?
X
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?
X
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?

d) In flood hazard, tsunami, or seiche zones, risk release of pollutants due to project inundation?
X
e) Conflict with or obstruct implementation of a water
quality control plan or sustainable groundwater
management plan?
X

IMPACT ANALYSIS

4.10a Would the project v iolate water quality or waste discharge requirements or otherwise substantially degrade surface or groundwater quality?
Construction: Less Than Significant Impact. The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. C onstruction Rialto 6th Cycle HEU
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activities for future housing development facilitated by the Project would include excavation, grading, and trenching, which would displace soils and temporarily increase the potential for soils to be subject to wind and water erosion.

However, construction activities disturbing one acre or more would be required to comply with the Construction General Permit issued under the NPDES program, as administered by the Santa Ana RWQCB.

To obtain coverage under the Construction General Permit, project applicants are required to submit a Notice of Intent (NOI) and associated documents to the State Water Resources Control Board (SWRCB).

The Construction General Permit requires the preparation and implementation of an SWPPP that identifies and implements BMPs for erosion control, sediment control, and pollution prevention during construction.

These measures, along with ongoing site inspections and required corrective actions, are designed to prevent discharges that would violate water quality standards or waste discharge requirements.

Compliance with the Construction General Permit and other applicable local and state requirements would ensure that future housing development facilitated by the Project does not result in substantial degradation of surface water or groundwater quality. Therefore, construction-related impacts would be less than significant, and no mitigation is required.

Operations: Less Than Significant Impact. The City is under the jurisdiction of the Santa Ana RWQCB, which establishes water quality objectives and standards for both surface and groundwater , as well as applicable waste discharge requirements. Under the Santa Ana RWQCB ’s NPDES permit program , all existing and future municipal discharges to surface waters within the City are subject to regulations. NPDES permits are required for operators of Municipal Separate Storm Sewer Systems (MS4s), as well as for construction projects and certain industrial activities.

Future housing development facilitated by the Project could result in increased stormwater runoff from impervious surfaces such as rooftops, streets, and parking lots. Operational activities, such as landscaping, vehicle use, waste disposal, and pet waste, could contribute pollutants to stormwater runoff, potentially affecting water quality if not properly managed.

However, all future development would be subject to the City’s development review process, which includes evaluation under CEQA where applicable, and compl iance with the City’s General Plan policies and Rialto Code Chapter 12.60, which outlines requirements to protect and enhance the water quality of local, state, and federal watercourses, water bodies, groundwater, and wetlands in a manner pursuant to and consistent with the Clean Water Act , 33 U.S.C. § 1251- 1387, and the Porter-Cologne Water Quality Control Act, Water Code § 13000 et seq..

Future housing development facilitated by the Project would be subject to General Plan Measure 8.17 (NPDES Compliance), which requires the following:
• Use of structural and non-structural BMPs to reduce pollutant loads and runoff volumes. • Minimization of impervious surface areas and flow velocity. • Maximization of on-site infiltration and temporary stormwater retention. • Avoidance of disturbance to natural watercourses.
• Implementation of source control and treatment measures close to pollutant sources.

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Rialto Code Chapter 12.60 further requires that developers install, implement, and maintain BMPs for erosion control, materials storage, routine maintenance, and preparation of a SWPPP . Residential developments are required to include BMPs for landscaping, property maintenance, and motor vehicle care.

Compliance with these local, regional, and state, including MS4 permit conditions and NPDES objectives, would prevent violation of water quality standards or waste discharge requirements and ensure that future housing development facilitated by the Project does not substantially degrade surface or groundwater quality. Therefore, impacts would be less than significant, and no mitigation is required.

4.10b 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. In 2014, the State of California adopted the Sustainable Groundwater Management Act (SGMA) to improve long -term groundwater management. SGMA requires that Groundwater Sustainability Agencies (GSAs) be established for all high- and medium-priority basins and implement Groundwater Sustainability Plans (GSPs) to avoid adverse impacts such as overdraft, land subsidence, and water quality degradation.

The City’s potable water is supplied by three water agencies: the City of Rialto Department of Public Works Water Division, the West Valley Water District (WVWD), and the Fontana Water Company (FWC).35 These agencies draw from adjudicated water supplies sourced in part from four groundwater basins : the Lytle Creek Surface Water Basin, the Rialto Groundwater Basin, the Bunker Hill Groundwater Basin, and the Chino Hill Groundwater Basin. E ach of these basins has a designated safe yield to avoid overdrafting groundwater resources. Local water agencies operate within those limits and are not permitted to extract water beyond sustainable thresholds.

Of the 258 candidate housing sites, 150 are already developed with impervious surfaces that limit groundwater infiltration. The intensification of existing development on these sites would not result in a significant change in recharge potential . However, development of the 108 currently vacant candidate housing sites could reduce the pervious surface area and, if not properly managed, could interfere with groundwater recharge.

To reduce such impacts, future housing development facilitated by the Project would be required to comply with applicable stormwater management regulations, including the NPDES program and Rialto Code Chapter 12.60. These regulations require the incorporation of low -impact development features such as stormwater retention basins, infiltration areas, and permeable paving, which support on- site retention and infiltration of stormwater to aid groundwater recharge. Additionally, treatment control and hydromodification management facilities would be implemented as necessary to reduce runoff and promote infiltration, thereby assisting with groundwater recharge.

The Project does not propose the use of any new wells or other direct groundwater extraction activities.

All future development would be served by municipal water providers operating within regulated groundwater allocations. Further more, General Plan Policy 2 -28.2 requires minimizing impervious surfaces and protecting open space recharge areas to maximize recharge of local groundwater basins.

35 City of Rialto. (2010). Rialto General Plan. https://www.rialtoca.gov/653/General -Plan. Accessed April 15, 2025.

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Policy 2-28.3 requires sidewalks, roads, and driveways to be designed to minimize impervious surfaces and provide flood control channels with permeable bottoms to help restore groundwater aquifers.

Although future housing development on currently vacant candidate housing sites would incrementally reduce open land available for recharge, compliance with the existing regulatory framework (i.e., General Plan policies and Rialto Code standards) would ensure that groundwater supplies are not substantially depleted and that recharge is not significantly impaired. Therefore, impacts would be less than significant, and no mitigation is required.

4.10c Would the project substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or through the addition of impervious surfaces, in a manner which would:
i) Result in substantial erosion or siltation on- or off-site? Less Than Significant Impact. Development on a majority of candidate housing sites would occur in areas that are already developed and, as such, would not alter the existing course of a stream or river. Of the 258 candidate housing sites, 108 are currently vacant. Future housing development facilitated by the Project would increase impervious surface area, potentially altering existing site-specific drainage patterns and increasing the risk of soil erosion.

However, all future housing development, regardless of site conditions, would be subject to the Construction General Permit under the NPDES program, administered by the Santa Ana RWQCB. The Construction General Permit requires the preparation and implementation of a SWPPP, which must include erosion control and sediment control BMPs designed to reduce or prevent construction -related pollutant discharge; see also Response 4.10a.

In addition, the General Plan also contains policies designed to minimize stormwater and erosion impacts during construction. Policy 2 -23.3 requires the use of drainage improvements designed, with native vegetation where possible, to retain or detain water runoff and minimize pollutants into the drainage system. Policy 5-2.4 requires the implementation of adequate erosion control measures for development projects to minimize sedimentation damage to drainage facilities.

Compliance with the Construction General Permit, local stormwater regulations, and applicable General Plan policies would prevent or minimize soil erosion and siltation resulting from future housing development facilitated by the Project. Therefore, impacts related to substantial erosion or siltation would be less than significant.
ii) Substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off-site?
iii) Create or contribute runoff water which would exceed the capacity of existing or planned storm water drainage systems or provide substantial additional sources of polluted runoff??
Less Than Significant Impact. As discussed above, on currently developed sites, future housing development facilitated by the Project would not substantially alter existing drainage patterns, as these areas are already developed with existing uses, impervious surfaces, and stormwater infrastructure .

However, the development of currently vacant sites with pervious surfaces, such as bare soil or vegetation, would increase impervious surface area, potentially increasing the volume and rate of stormwater runoff.

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This increased runoff, if not properly managed, could exceed the capacity of existing or planned stormwater infrastructure and contribute to localized or downstream flooding. To address these risks, General Plan Policy 2 .28-2 and Policy 2.28- 3 require the minimization of impervious surfaces and the incorporation of features that promote groundwater recharge and reduce runoff volume . Policy 5 -2.6 requires new developments to be designed with water retention devices and permeable surfaces to minimize flooding of the surface drainage system by peak flows.

Additionally, City Ordinance No. 1318 (Rialto Code Chapter 18.75) mandates that new development and redevelopment projects prepare and implement stormwater management plans to control runoff and prevent pollutant discharges into the municipal storm drain system. It also prohibits activities that could degrade water quality.

Furthermore, future housing development facilitated by the Project would be subject to federal, state, and local stormwater regulations, including the Construction General Permit under the NPDES program and the City’s erosion control requirements codified in Rialto Code § 17.40.010.

Collectively, these regulations and General Plan policies would ensure that future housing development facilitated by the Project would not substantially increase runoff in a manner that would result in flooding or exceed stormwater system capacity . Impacts would be less than significant, and no mitigation is required.
iv) Impede or redirect flood flows?
Less Than Significant Impact. According to the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps, most of the City is in Flood Hazard Zone X, which is identified as a 500-year floodplain, an area of minimal flood hazard. However, portions of Rialto are vulnerable to inundation from 100-year flood events associated with Lytle Creek and in a low-lying area of Sycamore Flat. 36 The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future housing development facilitated by the Project on sites located in or adjacent to mapped flood areas could potentially impede or redirect flood flows.

However, the General Plan Safety Element establishes Goal 5 -2 to create a more flood -safe community through development standards and infrastructure improvements. Flood-related policies, including Policy 5-2.3, require properties located within designated 100-year flood zones to submit information prepared by qualified specialists that certify compliance with development standards established for 100-year flood zones. Policy 5-2.7 requires any structure proposed within an officially designated 100-year floodplain, or other floodplain as determined through geotechnical investigation, to be designed in a manner that does not negatively impede or redirect floodwaters or raise anticipated flood heights.

Future housing development facilitated by the Project would be subject to site-specific review during the City’s development review process, which would ensure conformance with these policies and relevant FEMA and local floodplain management standards. Therefore, compliance with the existing regulatory framework and General Plan policies would ensure that future development would not substantially impede or redirect flood flows. Impacts would be less than significant, and no mitigation is required.

4.10(d) Would the project, i n flood hazard, tsunami, or seiche zones, risk release of pollutants due to project inundations?

36 City of Rialto. (2023). Rialto Focused General Plan Update 202 3. https://www.rialtoca.gov/773/2023- City-of-Rialto-Focused-General-Plan, adopted by the City Council on November 12, 2024. Accessed April 15, 2025.

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Less Than Significant Impact. The City is located approximately 45 miles inland from the Pacific Ocean.

Given the distance from the coast, the potential for the candidate housing sites to be inundated by a large, catastrophic tsunami is extremely low. No steep slopes are in the City’s vicinity; therefore, the risk of mudflow is insignificant. Additionally, as previously noted, FEMA identifies most of the City to be in Flood Hazard Zone X, which is defined as a 500-year floodplain, an area of minimal flood hazard.

Future housing development could occur in an area of minimal flood hazard, creating a potential risk of pollutant release. However, f uture housing development facilitated by the Project would be subject to Rialto Code Chapter 18.75: Floodplain Management Ordinance, which is designed to restrict or prohibit development within areas subject to flooding. Should housing development be permitted within a flood zone, compliance with General Plan Policy 5-2.3, which requires the submittal of information prepared by qualified specialists to certify compliance with development standards established for 100 -year flood zones, would be required. These regulations minimize impacts by preventing the destruction of housing units and thereby protecting life and property.

As concluded in Response 4.9a, operations associated with future housing development would involve only limited quantities of hazardous materials such as common household fertilizers, pesticides, paint, solvents, and petroleum products. T hese materials , used in limited amounts, are not considered a significant hazard to the public. As concluded in Response 4.10a, future housing development is also expected to have a less than significant impact on water quality.

Therefore, although the Project could facilitate housing and population within a 100- year floodplain, compliance with the existing regulatory framework would ensure the Project result s in a less than significant impact concerning the risk of pollutant release due to project inundation . Impacts would be less than significant, and no mitigation is required.

4.10e Would the project conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan?
Less Than Significant Impact. See Response 4. 10a regarding water quality control . Additionally, future housing development facilitated by the Project would comply with the existing regulatory framework and would not substantially decrease or interfere with groundwater recharge, thereby ensuring the Project does not impede sustainable groundwater management of the basin. Therefore, the Project would not conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan, and a less than significant impact would occur.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA or MM are applicable to the proposed Project.

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4.11 LAND USE AND PLANNING
Environmental Issue
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
Would the project:
a) Physically divide an established community? X
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?
X

IMPACT ANALYSIS

4.11a Would the project physically divide an established community? No Impact. Projects that divide an established community typically involve large -scale linear infrastructure, such as freeways, highways, or drainage channels that bisect neighborhoods or create barriers to movement within a community. The Project would not directly construct new housing but would facilitate housing development through implementation of the HEU.

Future housing development facilitated by the Project would occur on sites zoned for residential uses. As previously noted, of the 258 candidate housing sites, 150 are currently developed and would be considered infill development. Additionally, candidate housing sites are dispersed throughout the City, rather than concentrated in a single location. The Project does not propose infrastructure improvements that would bisect or physically divide existing communities. T herefore, future housing development facilitated by the Project would not physically divide an established community. No impact would occur, and no mitigation is required.

4.11b Would the project conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to, the general plan, specific plan, local coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect?
SCAG Connect SoCal 2024: Less Than Significant Impact. SCAG adopted Connect SoCal 2024, the region’s current RTP/SCS, on April 4, 2024. The plan guides long -term land use and transportation planning throughout the SCAG region and was adopted, in part, to reduce environmental impacts such as GHG emissions, air pollution, and vehicle miles traveled. The proposed Project would facilitate future housing in infill areas served by transit and existing infrastructure, aligning with the regional growth strategy envisioned in Connect SoCal 2024. As shown in Table 4 .11-1: Connect SoCal 2024 and 2020 Goal Consistency Analysis, the Project would not conflict with any applicable goal or policy of Connect SoCal 2024 and would further regional and statewide goals related to VMT reduction , resource conservation, and equitable housing development. Therefore, the Project would not cause a significant environmental Rialto 6th Cycle HEU
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impact due to a conflict an applicable plan adopted for the purpose of avoiding or mitigating an environmental effect. Impacts would be less than significant, and no mitigation is required.

Table 4.11-1: Connect SoCal 2024 Consistency Analysis
Connect SoCal 2024 Goal Consistency
Connect SoCal 2024
Mobility: Build and maintain an integrated multimodal transportation network.

SG1: Support investments that are well-maintained and
operated, coordinated, resilient, and result in improved safety, improved air quality, and minimized greenhouse
gas emissions.

No Conflict . While the Project is not a transportation improvement project, housing development facilitated
by the Project w ould provide diverse and affordable
housing (including multi-family and ADUs) near jobs and commercial centers, thereby reducing VMT and
associated GHG emissions.

SG2: Ensure that reliable, accessible, affordable , and appealing travel options are readily available, while
striving to enhance equity in the offerings in high -need communities.

No Conflict. Future housing development facilitated by
the Project would be located near existing transit and
active transportation networks, offering residents
accessible mobility options and improving equitable
access to jobs and services.

Communities: Develop, connect, and sustain livable and thriving communities.

SG3: Create human -centered communities in urban,
suburban, and rural settings to increase mobility options and reduce travel distances.

No Conflict. The Project would facilitate infill housing in established areas, reducing travel distances and
increasing access to transit, consistent with smart
growth principles.

Environment: Create a healthy region for the people of today and tomorrow.

SG4: Develop communities that are resilient and can
mitigate, adapt to, and respond to chronic and acute
stresses and disruptions, such as climate change.

No Conflict. See SG3. Facilitated housing would meet
current energy and water efficiency codes, contributing to resilience and resource conservation.

SG5: Integrate the region’s development pattern and
transportation network to improve air quality, reduce
greenhouse gas emissions, and enable more sustainable
use of energy and water.

No Conflict. As discussed in Section 4.6: Energy and
Section 4.19: Utilities and Service Systems , housing
facilitated by the Project would comply with energy- and water-efficiency standards, reducing emissions and
improving sustainability.

SG6: Conserve the region’s resources. No Conflict. The Project would support resource conservation through compliance with Title 24
standards and local General Plan policies promoting
water conservation and sustainable construction
practices.

Rialto General Plan: Less Than Significant Impact. The General Plan serves as the overarching policy framework for managing the City’s physical, economic, and human resources. The proposed Project includes a General Plan Amendment to the Land Use Element to align land use designations with the zoning changes proposed under the Housing Element Program. This amendment is necessary to facilitate the future development of approximately 20 to 50 DU on candidate housing sites and to ensure consistency between the General Plan’s Land Use and Housing Elements.

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Following approval of the proposed General Plan amendment, the Project would remain consistent with all applicable General Plan goals and policies adopted for the purpose of avoiding or mitigating environmental effects. As summarized below in
Table 4.11-2: General Plan Consistency Analysis, future housing development facilitated by the Project would not conflict with the intent or implementation of relevant General Plan policies. Where applicable, such development would be subject to the City’s standard development review process, including compliance with the Rialto Code and applicable design guidelines.

Therefore, the Project would not cause a significant environmental impact due to a conflict with any General Plan policy adopted for the purpose of avoiding or mitigating an environmental effect. Impacts would be less than significant, and no mitigation is required.

Table 4.11-2: General Plan Consistency Analysis
General Plan Policy Project Consistency
Chapter 2: Managing Our Land Supply
Goal 2 -1: Revitalize and enhance the Foothill Boulevard Corridor into a place that supports economic development and creates a sense of place and identify through the use of appropriate streetscape design inspired by the Rialto Bridge.

Policy 2-1.1: Provide new opportunities along the
Foothill Boulevard Corridor for mixed -use
residential, retail, and commercial uses.

No Conflict. The Project would facilitate future housing development along the Foothill Boulevard Corridor.

Goal 2-15: Protect scenic vistas and scenic resources.

Policy 2 -15.1: Protect views of the San Gabriel
and San Bernardino Mountains by ensuring that
building heights are consistent with the scale of
surrounding, existing development.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. See also Section 4.1: Aesthetics . Future housing projects would be subject to development review by the City.

Policy 2-15.2: Protect views of the La Loma Hills,
Jurupa Hills, Box Spring Mountains, Moreno
Valley, and Riverside by ensuring that building
heights are consistent with the scale of
surrounding, existing development.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. See also Section 4.1: Aesthetics
. Future housing projects would be
subject to development review by the City.

Policy 2 -15.3: Ensure use of building materials
that do not produce glare, such as polished
metals or reflective windows.

Goal 2-17: Improve the architectural and design quality of development in Rialto.

Policy 2 -17.1: Require new development and
construction to exhibit a high level of quality
architectural design to emphasize community
uniqueness, individuality, and historical
references.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City.

Policy 2 –17.5: Require developers to vary
building and parking setbacks along the
streetscape to create visual interest.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City.

Policy 2 –17.6: Require architectural treatments
on all façades facing rights-of-way, public streets,
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General Plan Policy Project Consistency
and alleys, including windows, doors,
architectural details, and landscape treatment.
housing projects would be subject to development review by the City.

Goal 2-18: Provide high-quality and environmentally sustainable landscaping.

Policy 2 -18.2: Require all new development to
incorporate tree plantings dense enough to
shade and beautify residential and commercial
areas.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City.

Policy 2 -18.3: Require the use of drought -
tolerant, native landscaping and smart irrigation
systems for new development to lower overall
water usage.

Goal 2-20: Encourage neighborhood preservation, stabilization, and property maintenance.

Policy 2 -20.1: Require that new construction,
additions, renovations, and infill developments
be sensitive to neighborhood context and
building form and scale.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City.

Policy 2–20.2: Encourage property maintenance
by requiring new development to submit precise
plans of design to maintain landscape areas that
incorporate property maintenance standards
from the City’s property maintenance ordinance.

Goal 2-24: Minimize the visual impact of parking lots
Policy 2 -24.1: Require mature trees and
landscaping in off -street parking areas to make
them more inviting and aesthetically appealing,
and to provide sufficient shading to reduce heat.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City and would be required to comply with Rialto Code Chapter 18.58.060 : Residential Parking Requirements, which includes landscaping provisions for multiple -family residential projects.

Policy 2 -24.3: Require use of drainage
improvements designed, with native vegetation
where possible, to retain or detain water runoff
and minimize pollutants into drainage system.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City and would be required to comply with Rialto Code Chapter 12.60: Municipal Separate Storm Sewer System (MS4), which includes regulations to control discharges into the City’s municipal storm sewer system.

Goal 2-29: Protect and enhance Rialto’s surface waters and groundwater basins.

Policy 2 -29.3: Design sidewalks, roads, and
driveways to minimize impervious surfaces;
provide flood control channels with permeable
bottoms to help restore groundwater aquifers.

Goal 2-30: Conserve water resources.

Policy 2-30.1: Require new development to use
features, equipment, technology, landscaping,
and other methods to reduce water
consumption.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City and would be required to adhere to Rialto Code Chapter Rialto 6th Cycle HEU
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General Plan Policy Project Consistency

18.61: Design Guidelines, which include s standards for automatic irrigation systems and the use of drought -tolerant landscape materials to foster long-term water conservation.

Goal 2-31: Incorporate green building and other sustainable building practices into development projects.

Policy 2-31.1: Explore and adopt the use of green
building standards and Leadership in Energy and
Environmental Design (LEED) or similar in both
private and public projects.

No Conflict . Future housing development facilitated by the Project would be required to comply with applicable CALGreen standards (24 CCR, Part 11), which include requirements for water efficiency, construction waste reduction, recycling, and electric vehicle facilitation.

Policy 2 -31.3: Support sustainable building
practices that integrate building materials and
methods that promote environmental quality,
economic vitality, and social benefit through the
design, construction, and operation of the built
environment.

No Conflict . Future housing development facilitated by the Project would be required to comply with regulatory
requirements to (a) divert at least 50 percent of construction and demolition waste from landfills; (b) mandatory inspections of energy systems to ensure optimal working efficiency; (c) low pollutant emitting exterior and interior finish materials, such as paints, carpets, vinyl flooring and particle boards; and (d) a 20% reduction in indoor water use.

Goal 2-32: Conserve energy resources.

Policy 2 -32.1: Require the incorporation of
energy conservation features into the design of
all new construction and site development
activities.

No Conflict. See Policy 2-31.2.

Goal 2-35: Achieve waste recycling levels that meet or exceed State mandates. Achieve maximum waste recycling in all sectors of the community: residential, commercial, industrial, institutional, and construction.

Policy 2-35.2: Utilize source reduction, recycling,
and other appropriate measures to reduce the
amount of solid waste generated in Rialto that is
disposed of in landfills.

No Conflict . Future housing development facilitated by the Project would include measures to recycle during construction and operation when feasible. See also the response to Policy 2-

31.3. Policy 2-35.3: Encourage the maximum diversion
from landfills of construction and demolition
materials through recycling and reuse programs.

No Conflict. See the response to Policy 2-31.3.

Goal 2-36: Reduce air pollution emissions from both mobile and stationary sources in the City.

Policy 2 -36.2: Require that new development
projects incorporate design features that
encourage ridesharing, transit use, park and ride
facilities, and bicycle and pedestrian circulation.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City.

Goal 2-37: Reduce the amount of fugitive dust released into the atmosphere.

Policy 2–37.2: Support programs and policies of
the South Coast Air Quality Management District
regarding restrictions on grading operations at
construction projects.

No Conflict . As discussed in Section 4.2: Air Quality , future housing development facilitated by the Project would be required to comply with SCAQMD Rules 402, 403, and 1113.

Rules 402 and 403 include measures to minimize the generation of construction dust. Rule 1113 includes measures to reduce ROG emissions associated with architectural coatings.

Chapter 3: Investing in Our Future: Economic Development, Redevelopment, and Infrastructure Goal 3-8: Promote affordable and quality water service capable of adequately meeting normal and emergency water demands to all areas in Rialto.

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General Plan Policy Project Consistency
Policy 3-8.1: Require that all new development or
expansion of existing facilities bear the cost of
expanding the water system to handle the
increased demands which they are expected to
generate.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City, which would ensure future development projects provide their fair share of the cost of expanding the water system, as applicable.

Policy 3 -8.10: Support water conservation
through requirements for landscaping with
drought-tolerant plants and efficient irrigation for
all new development and City projects.

18.61: Design Guidelines, which include s standards for automatic irrigation systems and the use of drought -tolerant landscape materials to foster long-term water conservation.

Goal 3-9: Upgrade and maintain an improved wastewater system with adequate plant efficiency and capacity to protect the health and safety of Rialto residents, businesses, and institutions.

Policy 3-9.1: Require that all new development or
expansion of existing facilities bear the cost of
expanding the wastewater disposal system to
handle the increased loads which they are
expected to generate.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City, which would ensure future development projects provide their fair share of the cost of expanding the wastewater disposal system, as applicable.

Goal 3-10: Minimize the volume of solid waste that enters local and regional landfills.

Policy 3 -10.2: Encourage the recycling of
construction and demolition materials in an effort
to divert these items from entering landfills.

No Conflict. See the response to Policy 2-31.3.

Chapter 4: Making the Connections: The Circulation Chapter Goal 4-1: Provide transportation improvements to reduce traffic congestion associated with regional and local trip increases.

Policy 4 -1.20: Design City streets so that
signalized intersections operate at Level of
Service (LOS) D or better during the morning and
evening peak hours, and require new
development to mitigate traffic impacts that
degrade LOS below that level. The one exception
will be Riverside Avenue south of the Metrolink
tracks all the way to the City’s southern border,
which can operate at LOS E.

No Conflict. Automobile delay, as measured by LOS, no longer constitutes a significant environmental effect under CEQA.

Notwithstanding, future housing development facilitated by the Project would be required to pay the City’s Regional and Local Traffic Development Imp act Fee, which would be used to improve regional and local traffic networks.

Goal 4-8: Establish and maintain a comprehensive system of pedestrian trails and bicycle routes that provide viable connections throughout the City.

Policy 4 -8.5: Require major developments to
include bicycle storage facilities, including bicycle
racks and lockers.

No Conflict. Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City and would be required to comply with Rialto Code Chapter 18.61: Design Guidelines, which includes requirements for bicycle storage.

Goal 4-9: Promote Walking.

Policy 4-9.2: Require sidewalks and parkways on
all streets in new development.

No Conflict. See Policy 4-9.4.

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General Plan Policy Project Consistency
Policy 4 -9.4: Accommodate pedestrians and
bicyclists — in addition to automobiles — when
considering new development projects.

18.61: Design Guidelines, which include requirements for accommodating pedestrians, bicyclists, and automobiles.

Chapter 5: Safety and Noise
Goal 5–1: Continue to build the City’s ﬁre protection and prevention programs and requirements to minimize ﬁre hazards.

Policy 5 –1.3: Require that all site plans,
subdivision plans, and building plans be reviewed
by the Fire Department to ensure compliance with
appropriate fire regulations, such as California Fire
Safe Regulations.

No Conflict . Future housing development facilitated by the Project would not conflict with the intent of this policy. Future housing projects would be subject to development review by the City. Applicable City departments would review project plans to ensure compliance with General Plan policies
, Rialto Code
standards, and all emergency response and fire safety
requirements of the Rialto Fire Department and the California Fire Code.

Goal 5–2: Create a more ﬂood-safe community through development standards and infrastructure improvements.

Policy 5 –2.4: Require the implementation of
adequate erosion control measures for
development projects to minimize sedimentation
damage to drainage facilities.

No Conflict. Future housing projects facilitated by the Project would require a SWPPP and WQMP, which would include
erosion control Best Management Practices (BMPs) to minimize potential impacts associated with erosion. See
Section 4.7:

Geology and Soils and Section 4.9: Hydrology and Water Quality.

Policy 5 –2.6: Design new developments with
water retention devices and permeable surfaces
to minimize flooding of the surface drainage
system by peak flows. Consult with water agencies
and the San Bernardino County Flood Control
District to consider the potential for la rger-scale
capture via diversion to large -scale spreading
grounds or other options on a site-by-site basis.

No Conflict. Future housing projects facilitated by the Project would be designed with water retention devices and permeable surfaces to minimize flooding of the surface drainage system by peak flows, in accordance with regulatory requirements.

Goal 5-5: Minimize impacts to public health, safety, and welfare as a result of seismic and geologic hazards.

Policy 5–5.1: Require geotechnical investigations
by certified engineering geologist or other
qualified professionals for all grading and
construction projects subject to geologic hazards,
including fault rupture, severe ground shaking,
liquefaction, landslides, and col lapsible or
expansive soils. Particular attention should be
paid to areas within Alquist -Priolo Earthquake
Fault Zones.

No Conflict. As addressed in Section 4.7: Geology and Soils , future housing development facilitated by the Project would be required to provide a site -specific, design -level geotechnical investigation for review and approval to the City of Rialto Community Development Department and Public Works
Department. The City would review all Project plans for grading, foundation, structural, inf
rastructure, and all other relevant
construction permits relative to the Preliminary Geotechnical Investigation’s recommend ations and Rialto C ode
requirements.

Policy 5 –5.2: Require all construction to be in
conformance with the California Building Code
(CBC), and to be consistent with the Municipal
Code as it provides for earthquake resistant
design, excavation, and grading.

No Conflict. State laws and local ordinances require that, prior to construction, potential seismic hazards be identified and mitigated, as needed, to protect public health and safety from substantial risks through appropriate engineering practices. As addressed in Section 4. 7: Geology and Soils , f uture housing Rialto 6th Cycle HEU
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General Plan Policy Project Consistency
development facilitated by the Project would be required to conform to California Building Code and California Health and Safety Code seismic design requirements (or applicable adopted code at the time of plan submittal or grading and building permit issuance for construction). The buil ding and safety standards established by these codes have been developed to ensure structural integrity during seismic events.

Goal 5–8: Ensure that first responders and the Emergency Operations Center (EOC) have adequate capacity to respond to hazard events.

Policy 5 –8.7: Require that development be
phased in relation to the City’s ability to provide
an adequate level of fire protection, pursuant to
the City standard of cover and fire department
strategic plan.

No Conflict. All future housing development facilitated by the Project would be subject to the City’s development review process and would be assessed on a case -by-case basis, and would need to demonstrate that an adequate level of fire protection exists or if the construction or expansion of existing fire services or facilities is required. See Section 4.17: Public Services for further information and analysis regarding public services, including fire protection.

Goal 5–10: Provide effective, timely and comprehensive policing services that meet the safety needs of Rialto.

Policy 5 -10.3: Continue to encourage design
concepts that inhibit and discourage criminal
behavior such as Crime Prevention Through
Environmental Design (CPTED) techniques.

No Conflict. As addressed in Section 4.14: Public Services, prior to commencement of construction activities, future
development facilitated by the Project would be reviewed by the City to ensure compliance with General Plan policies and Rialto Code standards, including the applicable regulations associated with site signage, lighting, perimeter control, and other crime safety preventative measures.

Chapter 7: Our Roots: Cultural and Historical Resources Goal 7-1: Preserve Rialto’s significant historical resources as a source of community identity, stability, aesthetic character, and social value.

Policy 7-1.1: Protect the architectural, historical,
agricultural, open space, environmental, and
archaeological resources in Rialto.

No Conflict. As discussed in Section 4.4: Cultural Resources, the future housing development facilitated by the Project would have a less than significant impact on unknown archaeological resources with the implementation of SC CUL-1 and MM CUL-1.

Source: City of Rialto. (2010). Rialto General Plan. https://www.rialtoca.gov/653/General-Plan. Accessed April 15, 2025.

City of Rialto. (2023). Rialto Focused General Plan Update 2024. https://www.rialtoca.gov/773/2023-City-of-Rialto-Focused-General-Plan.

Accessed April 15, 2025.

Rialto Code: Less Than Significant Impact. The Project proposes two zoning amendments:
• A Zoning Code Amendment to Rialto Code Title 18 to rezone the added sites to apply the Residential Overlay (Rialto Code Chapter 18.116 – Residential Overlay. The Project would amend the Rialto Code by adding Chapter 18.116: Residential Overlay , over approximately 60 acres distributed throughout the City (i.e., the 30 added sites) . The residential overlay aims to permit attractive, high-density residential development in suitable areas of the City, while preserving existing development and maintaining the development potential of the underlying zone . The residential overlay allows housing development at densities ranging from 20 to 50 dwelling units per acre.

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• A Land Use Element and Zoning Map amendment to update the land use designations for the added sites to apply the Residential Overlay.

The proposed Project intends to provide the capacity (i.e., through modifications to existing zoning and land use designations) for the housing market to adequately address housing needs for all income groups, rather than generating the full development capacity housing within the planning cycle. Future housing development facilitated by the Project would be processed in accordance with the applicable zoning regulations and development standards in effect at the time a project is submitted. Future housing development facilitated by the Project would be subject to compliance with the Rialto Code, which is intended to allow the most appropriate use of land and prevent land use incompatibility . Compliance would be verified on a project- by-project basis. Overall, the proposed zoning changes described above would be required to meet the City’s RHNA. Following approval of the proposed zoning amendments, the Project would not conflict with the Rialto Code. Therefore, the Project would not cause a significant environmental impact due to a conflict with any Rialto Code standards adopted to avoid or mitigate an environmental effect. Impacts would be less than significant, and no mitigation is required.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA or MM are applicable to the proposed Project.

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4.12 MINERAL RESOURCES
Environmental Issue
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact

12. MINERAL RESOURCES. Would the project:
a) Result in the loss of availability of a known mineral resource that would be of value to the region and the
residents of the state?
X
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?
X

IMPACT ANALYSIS

4.12a 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?

4.12b 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? Less Than Significant Impact. The City’s General Plan Conservation Element identifies generalized Mineral Resources Zones (MRZs) in the City.37 The City is predominantly classified as MRZ-2, where geologic data indicate that significant Portland Cement Concrete (PCC) -grade aggregate resources are present, and MRZ-3, where mineral occurrences are known or inferred but the resource significance is undetermined.

The Project would not directly construct new housing but would facilitate housing development by implementing actions associated with the HEU. Future development would primarily occur in already urbanized and developed areas, including infill development on candidate housing sites that are not located within or near active or planned mineral extraction areas. The Rialto Code includes provisions to protect existing mining operations from encroachment by incompatible land uses and encourages mineral extraction in compatible areas. These provisions reduce the potential for land use conflicts with valuable mineral resources by guiding the siting and r egulation of both mining operations and surrounding development.

Although the General Plan does not include explicit goals or policies aimed at preserving access to mineral resources, it does include policies in the Managing Our Land Supply Element that are intended to minimize land use conflicts with mining operations and to support the appropriate reclamation and reuse of mining sites. While the City contains mapped mineral resources, none of the candidate housing sites are currently used, or designated, as important mineral resource recovery areas, and the Project would not displace or restrict access to such resources. Therefore, future development facilitated by the Project on candidate housing sites would not result in the loss of availability of a known mineral resource that would be of value

37 City of Rialto. (2023). Rialto Focused General Plan Update 2024. https://www.rialtoca.gov/773/2023- City-of-Rialto-Focused-General-Plan.

Accessed April 15, 2025.

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to the region or to the residents of California. Therefore, impacts would be less than significant, and no mitigation is required.

STANDARD CONDITIONS OF APPROVAL AND MITIGATION MEASURES No SCA or MM are applicable to the proposed Project.

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4.13 NOISE
Environmental Issue
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 , noise ordinance,
or applicable
standards of other agencies?

X
b) Generation of excessive ground -borne vibration or
ground-borne noise levels?
X

c) For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a
plan has not been adopted, within two miles of a
public airport or public use airport, would the project expose people residing or working in the project area
to excessive noise levels?

REGULATORY SETTING
California Government Code § 65302(f)
Government Code § 65302(f) requires that all General Plans include a Noise Element to address noise concerns in the community. State law also requires that current and future noise level contours be developed for the following sources:
• Highways and freeways
• Primary arterials and major local streets
• Passenger and freight on-line railroad operations and ground rapid transit systems • Commercial, general aviation, heliport, and military airport operations, aircraft flyovers, jet engine test stands, and all other ground facilities and maintenance functions related to airport operation
• Local industrial plants, including, but not limited to, railroad classification yards • Other stationary ground noise sources identified by local agencies as contributing to the community noise environment
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Rialto City CouncilFebruary 24, 2026

Rialto City Council
February 24, 2026