Corona City Council
July 1, 2026

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LIST OF TABLES
Table Number/Title Page
Page v
Table 41 Operational Noise Level Compliance .............................................................................................. 2-194 Table 42 Daytime Project Operational Noise Level Increases....................................................................... 2-195 Table 43 Nighttime Project Operational Noise Level Increases..................................................................... 2-195 Table 44 Existing with Project Traffic Noise Level Increases.......................................................................... 2-196 Table 45 Opening Year with Project Traffic Noise Increases.......................................................................... 2-196 Table 46 Vibration Source Levels for Construction Equipment..................................................................... 2-198 Table 47 Typical Construction Equipment Vibration Levels........................................................................... 2-198 Table 48 Project Consistency with General Plan Policies Related to Noise................................................... 2-201 Table 49 Project Emergency Response Analysis using Speed Limit Formula ................................................ 2-211 Table 50 Project Emergency Response Analysis using ISO Formula.............................................................. 2-211 Table 51 Project Consistency with General Plan Policies Related to Public Services and Recreation........... 2-217 Table 52 Trip Generation Comparison........................................................................................................... 2-228 Table 53 Project Consistency with General Plan Policies Related to Transportation .................................... 2-230 Table 54 Project Consistency with General Plan Policies Related to Utilities and Service Systems.............. 2-243

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1.0 INTRODUCTION

1.1 Background
On February 1, 2017, the City of Corona City Council certified the Final Environmental Impact Report (EIR) for the Skyline Heights project (herein, “SHP”). The EIR prepared for the SHP (herein, “SHP EIR”) evaluated the environmental effects associated with implementation of the SHP, which at the time was located within the western portion of the City of Corona Sphere of Influence (SOI). The location of the SHP site is depicted on Figure 1, Regional and Vicinity Map. The SHP included applications for General Plan Amendment No. 13-003 (GPA13- 003), Change of Zone No. 13-002 (CZ13-002), and Tentative Tract Map No. 36544 (TTM 36544). The SHP also included an application (Annexation No. 117) to prezone the approximately 394.8-acre property within the City of Corona’s Sphere of Influence (SOI) to facilitate annexation of this area into the jurisdictional limits of the City of Corona. As required by the Riverside Local Area Formation Commission (LAFCO), Annexation No. 117 also required City approval of a Plan of Service (PoS) as required by the Riverside Local Area Formation Commission (LAFCO).

Following certification of the SHP EIR, the City Council approved GPA13-003, CZ13-002, and TTM 36544 and approved the PoS for Annexation 117 on February 1, 2017, while Annexation 117 ultimately was approved by LAFCO on December 7, 2017 as part of LAFCO Application No. 2017-06-2.

As shown on Figure 2, General Plan Amendment No. 13-003, GPA13-003 was a proposal to change the City of Corona General Plan Sphere of Influence Land Use Plan (West Sphere) to amend 394.8 acres from “Rural Residential 1 (0.2 – 0.5 dwelling units/acre)” to “Low Density Residential (3-6 dwelling units/acre)” on 357.14 acres and “Open Space” on 37.61 acres. As shown on Figure 3, Change of Zone No. 13-002, CZ13-002 was a proposal to prezone 37.61 acres to Open Space, 86.23 acres to Agriculture, and 270.9 acres to R-1-7.2 (single-family residential, 7,200 square-foot minimum lot size) located in the City’s SOI (Westerly Sphere) to facilitate the annexation of property into the City of Corona. As shown on Figure 4, Tentative Tract Map No. 36544, TTM 36544 was a proposal to subdivide the property to include a total of 292 single-family lots on approximately 270.9 acres, including numerous lettered lots to be set aside for open space, slope landscaping, streets, and utilities in the R-1-7.2 zone that were proposed as part of CZ13-002. TTM 36544 also was designed in a manner so as to facilitate the completion of the Foothill Parkway Westerly Extension, which consisted of two miles of new four-lane highway from Trudy Way to Paseo Grande at Green River Road that would connect Sierra del Oro to south Corona and that would include connections to the new section of Foothill Parkway from both Border Avenue and Mangular Avenue, via Chase Drive. As shown on Figure 5, Annexation No. 117, was a proposal for a Plan of Service and prezoning associated with the annexation of approximately 395 acres into the City from the unincorporated area of Riverside County, generally located southwest of Foothill Parkway and east of Paseo Grande within the City’s southwest SOI.

Richland Ventures, Inc. (herein, “Project Applicant”) has filed applications with the City of Corona for a Specific Plan (SP No. SP2025-0001) and a Revised Tentative Tract Map (TTM 36544R1), which collectively are referred to herein as the “Project” or “proposed Project.” As more fully discussed in Subsection 1.3, approval of these applications would allow for development of the 249.39-acre property with 92 single-family detached housing units (on 7,200 square foot [s.f.] lots), three custom single-family lots, 104 eight-cluster single-family detached housing units, and 77 four-cluster single-family detached housing units for a total of 276 units, along with private parks, public parks, pump stations/water tanks, and open space.

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Figure 1 Regional and Vicinity Map

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Figure 2 General Plan Amendment No. 13-003

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Figure 3 Change of Zone No. 13-002

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Figure 4 Tentative Tract Map No. 36544

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Figure 5 Annexation No. 117

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1.2 Location and Surrounding Land Uses
As shown above on Figure 1, the Project site is located approximately 3 miles west of Interstate 15 (I-15) along the southwestern boundary of the City of Corona and is adjacent to, and southwest of, the Foothill Parkway Westerly Extension.

To the northeast of the Project site and the Foothill Westerly Extension, established single-family neighborhoods are situated. These areas are primarily zoned for low-density residential use (R-1-7.2, R-1-8.4, and R-1-9.6).

Interspersed among these residential neighborhoods are large, undeveloped parcels within the Open Space (OS) zone.

To the west and south of the project site lies the Cleveland National Forest, easily accessible via Skyline Drive, a graded forest service road located to the south. This road provides local and regional residents with recreational opportunities, including hiking and mountain biking, within the scenic and expansive National Forest.

1.3 Proposed Project Modifications
On February 1, 2017, the City of Corona City Council approved the Skyline Heights project (herein, “Approved Project”) and certified the Skyline Heights EIR (herein, “SHP EIR”). The Approved Project consisted of applications for a General Plan Amendment, Change of Zone, and a Tentative Tract Map (TTM 36544) to allow for future development of a 270.9-acre property1 located west of Foothill Parkway and north of Skyline Drive within the City of Corona, California. TTM 36544 entailed the subdivision of the property into 292 single family residential lots, as well as lettered lots for open space and landscaping. The Skyline Heights Project EIR determined that implementation of the Approved Project would result in significant and unavoidable impacts under the issue of Aesthetics but determined that all other impacts associated with the Approved Project would be less than significant or would be reduced to less-than-significant levels with the implementation of mitigation measures.

Subsequent to approval of the Approved Project, the Project Applicant, Richland Ventures, has identified design issues with the previously approved design and is proposing the Skyline Heights Specific Plan (SHSP) and Revision No. 1 to TTM 36544 (TTM 36544R1). These applications are described below.

1.3.1 Skyline Heights Specific Plan (SHSP)
The Skyline Heights Specific Plan (SHSP) is proposed to establish a master-planned community that accommodates 276 homes on 65.41 acres, 11.42 acres of private and public park space, two pump station/tank sites on 1.5 acres, HOA-maintained slopes on 49.07 acres, and the preservation of approximately 121.99 acres of undisturbed open space. Approval of the SHSP would provide the City of Corona with a set of regulations and guidelines to help create a high-quality planned residential community, ensuring the orderly development of the Project site and systematic implementation of the City’s General Plan. A description of the proposed SHSP is provided below, while a copy of the draft SHSP is included as Technical Appendix A to this EIR Addendum. 1 While the SHP EIR indicated that the property was 270.9 acres in size, approximately 21.51 acres of the Project site previously were dedicated to the City of Corona to accommodate the City’s Foothill Parkway Expansion Project, reducing the size of the Project site to 249.39 acres.

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a) Proposed Land Use Plan
As shown on Figure 6, Skyline Heights Specific Plan Land Use Plan, and as summarized in Table 1, Skyline Heights Specific Plan Land Use Allocation Summary, the SHSP would establish three (3) separate planning areas, as follows:
• Planning Area 1: SHSP Planning Area (PA) 1 would comprise approximately 35.72 acres in size, and would allow for 104 single-family dwelling units on minimum 7,200 square-foot (s.f.) lots in a cluster configuration on approximately 13.10 acres, with an overall residential density of 2.9 dwelling units per acre (du/ac) and an allowable density range of 3 to 6 du/ac. PA 1 also would accommodate 6.28 acres of slopes to be maintained by the Homeowners’ Association (HOA), along with 16.34 acres of undisturbed natural open space.
• Planning Area 2: SHSP PA 2 would encompass approximately 143.43 acres in size, and would allow for up to 95 single-family dwelling units on approximately 36.24 acres on minimum 7,200 s.f. lots, with an overall residential density of 0.7 du/ac and an allowable density range of 3 to 6 du/ac. PA 2 also would accommodate a 1.95-acre private park, 9.25 acres of public parks (that include 3.61 acres of natural open space), a 0.38-acre site for a proposed pump station/water tank, 30.19 acres of HOA-maintained slopes, and 65.42 acres of undisturbed natural open space.
• Planning Area 3: SHSP PA 3 would encompass approximately 70.24 acres in size, and would allow for up to 77 single-family dwelling units in a cluster configuration on approximately 16.07 acres, with an overall residential density of 1.1 du/ac and an allowable density range of 3 to 6 du/ac. PA 3 also would accommodate a private park on 0.22-acre, a 1.12-acre site for a pump station/water tank, 12.60 acres of HOA-maintained slopes, and 40.23 acres of natural open space.

Table 1 Skyline Heights Specific Plan Land Use Allocation Summary Planning Area Land Use Acres Density Range Density Units 1 Single Family District Cluster1 13.10 3-6 du/ac 2.9 du/ac 104 HOA Maintained Slopes 6.28 -- -- --
Natural Open Space 16.34 -- -- --
2 Single Family District1 36.24 3-6 du/ac 0.7 du/ac 95
Private Parks 1.95 -- -- --
Public Parks2 9.25 -- -- --
Pump Station/Tank Site 0.38 -- -- --
HOA Maintained Slopes 30.19 -- -- --
Natural Open Space 65.42 -- -- --
3 Single Family District Cluster1 16.07 3-6 du/ac 1.1 du/ac 77 Private Parks 0.22 -- -- --
Pump Station/Tank Site 1.12 -- -- --
HOA Maintained Slopes 12.60 -- -- --
Natural Open Space 40.23 -- -- --
Totals: 249.39 -- 1.1 du/ac 276
Notes:

1. Planning areas include local streets.

2. Public Park (Lot I) includes 3.61 acres of natural open space.

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Figure 6 Skyline Heights Specific Plan Land Use Plan

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b) Proposed Circulation Plan
The SHSP would establish a general layout and design standard of roadways throughout the site to safely meet the transportation needs of the community. Primary access to the site would be from Foothill Parkway, approximately 100 feet north of its intersection with Mabey Canyon. A second access along Foothill Parkway is proposed to the south of Mabey Canyon, which would align with Border Avenue, a local street. The primary entry road, “B” Street, would intersect with “A” Street to provide public access to the three public community parks proposed along “E” Street. “E” Street would provide a connection road through the public park sites, extending to a small residential enclave to “M” Street. “M” Street would provide a third access/egress to the project from Trudy Way, an existing local street. Internal roadways would provide access to individual lots within PA 2, while private common driveways would provide access to the proposed cluster homes within PAs 1 and 3.

An emergency access also is proposed within PA 1 at “P” Street from Mabey Canyon Drive to provide access for emergency vehicles and vehicular ingress and egress of surrounding residents and future residents only in the case of an emergency. Vehicular access would be restricted via a gate, designed to be opened electronically by emergency services, while full pedestrian access would be accommodated at the emergency access gate. c) Public Facilities
i) Conceptual Domestic and Reclaimed Water Facilities
Domestic and Reclaimed Water service for the proposed SHSP would be provided by the City of Corona. Domestic and recycled water service would be accommodated via connections to existing facilities and by expanding the existing domestic and recycled water system.

For domestic (potable) water service, the SHSP occurs within City of Corona Pressure Zones 5 and 6A. Proposed Planning Area 1 of the SHSP is the only portion of the Project site that can receive service from the Zone 5 system.

An 8-inch domestic water line is proposed to be constructed on site within Planning Area 1 (i.e., within “P” Street) to connect to an existing 16-inch water line within Foothill Parkway. A series of 8-inch water lines would be constructed within local roadways within Planning Area 1 to provide domestic water service to individual homes.

In addition, the City has identified the need for an additional Zone 5 reservoir in this area to hydraulically balance the system due to the distance between Planning Area 1 and the existing Zone 5 storage tanks. As such, the SHSP accommodates a proposed 2.5-million gallon Zone 5 reservoir within the central portion of the Project site. A 16- inch transmission line would be constructed on site to connect the reservoir to the existing 16-inch Zone 5 water main located within Foothill Parkway.

The remaining portions of the SHSP area would be served by the Zone 6A system, which is a new Zone that would be formed by pumping water from the new Zone 5 reservoir to an on-site Zone 6A water tank that is proposed within the western portions of the Project site (northwest of the proposed Zone 5 reservoir). The proposed Zone 6A tank would be sized to serve only future development proposed on site, and would have a minimum capacity of 0.40 million gallons.

For reclaimed water service, the Project would be served by the City of Corona 1380 Zone (Zone 3) water lines, which currently are supplied by the Water Recycling Facility (WRF) 3 Booster Station and Border Avenue Booster Station. Under existing conditions there is a 12-inch reclaimed water line within Foothill Parkway adjacent to the

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Project site. The Project would connect to the existing 12-inch reclaimed water line at two separate locations at the entrances to Planning Areas 1 and 2. A proposed 1380/1625 Zone closed booster station is proposed along Border Avenue within the Project site to boost pressures in the system in order to supply reclaimed water to the upper elevations of the site. In addition to common landscape areas, the proposed reclaimed water system also would provide water service to fire hydrants proposed along local roadways throughout the site. ii) Conceptual Wastewater Management Plan
The SHSP is located within the City of Corona Master sewer collection system that is tributary to the City’s Wastewater Treatment Plant No. 1. As part of the Project a gravity sewer system would be developed to provide sanitary sewer service to all proposed lots within the Project. Sewer flows for the Project have been separated into three drainage areas. Proposed SHSP Planning Area 1 would comprise the northernmost drainage area, and 8-inch sewer lines would be constructed within the local roadways to connect to an existing 8-inch sewer line within Mabey Canyon Road. Sewer service for approximately 17 dwelling units within the southern portions of the Project site would be provided via a proposed 8-inch sewer line to be constructed on site within “E” Street, which would connect to an existing 8-inch sewer line within Trudy Way. For the remaining portions of the Skyline Specific Plan area, a series of 8-inch sewer lines would be constructed within local roadways on site, which would extend northeasterly across Foothill Parkway within Border Avenue to an existing point of connection at the intersection of Raven Circle and Border Avenue.
iii) Conceptual Drainage Master Plan
As part of the Project a publicly-maintained storm drain system would be constructed on site. This system would consist of drainage inlets to intercept runoff from the undeveloped open space areas, catch basins within the public roadways to intercept runoff within public streets, storm drain structures and manholes, storm drain pipelines and outlet facilities into four proposed water quality basins. These basins would discharge into four existing inlet facilities and the City of Corona storm drain system. At both discharge points to the city system, the existing capacities for each storm drain system would be able to adequately accept the site’s 100-year flow rates following detention by the two detention basins proposed on site. Permanent Best Management Practices (BMPs) for post construction mitigation primarily would consist of extended detention basins at the primary discharge points near the perimeter of the Project. Other BMP’s may be available and these improvements, if any, would be identified in the development of the site-specific Storm Water Pollution Prevention Program (SWPPP) and operational Water Quality Management Plan (WQMP ). All water quality facilities would be maintained by the HOA.
d) Conceptual Phasing Plan
Buildout of the SHSP is anticipated to occur in two separate phases. Phase 1 would consist of the development of residential uses within Planning Area 1 within the northern portions of the Specific Plan area (i.e., north of Mabey Canyon Road). Phase 2 would consist of development of the remaining portions of the Skyline Heights Specific Plan area. While it is anticipated that Phase 1 would consist of mass grading of the entire Specific Plan area, infrastructure needed to serve each phase of development would be constructed as part of each individual phase.

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e) Development Regulations
Section 4 of the SHSP includes development regulations that establish definitions of terms; generalized development standards; permitted uses, accessory uses, and conditionally-permitted uses; residential development standards; development standards for signage; development regulations for walls, fences, and landscaping; and development standards for natural open space and public parks. f) Community Design Guidelines
Section 5 of the SHSP includes community design guidelines that are intended to provide general design criteria for future development on site. This Section includes architectural design criteria related to siting, setbacks, building elevations, building forms, exterior materials/finishes, garages, doors/windows, exterior details, and lighting. Also included in this section are a description of allowable architectural styles, which include Spanish Eclectic, Transitional Craftsman, Tuscan Farmhouse, Italian Revival, European Cottage, Modern American Farmhouse, Midwest Traditional, and any other architectural design as may be approved by the City of Corona.

Finally, Section 5.3 of the SHSP includes a Landscape Master Plan, which establishes landscaping design criteria for future development on site, identifies design criteria for Project walls and signage, identifies design criteria for Project streetscapes, and establishes an overall Master Plant Palette for general development on site, a Plant Palette for the Project’s required fuel modification zones, and a Plant Palette for the Project’s proposed detention basins. The Community Design Guidelines also provide design criteria for walls and fencing within the SHSP area. g) Implementation and Administrative Procedures
Section 6 of the Skyline Heights Specific Plan sets forth the policies and procedures for the City of Corona’s review and approval of implementing development projects within the Skyline Heights Specific Plan area and describes the methods and procedures for interpreting and amending the Skyline Heights Specific Plan. This section also describes infrastructure financing mechanisms as well as requirements related to maintenance.

1.3.2 Revision No. 1 to Tentative Tract Map No. 36544 (TTM 36544R1) In addition to the SHSP, the Project evaluated herein also includes an application for the Revision No. 1 to Tentative Tract Map No. 36544 (TTM 36544R1). As previously noted, Tentative Tract Map No. 36544 (TTM 36544) originally was approved by the City of Corona City Council on February 1, 2017, and entailed the subdivision of the property into 292 single family residential lots, as well as lettered lots for open space and landscaping. Subsequent to approval of TTM 36544, the Project Applicant, Richland Ventures, identified design issues with the previouslyapproved design and is proposing Revision No. 1 to TTM 36544 to address these concerns. Assummarized in Table 2, Revision No. 1 to TTM 36544 Statistical Summary, and as shown on Figure 7, Revision No. 1 to Tentative Tract Map No. 36544, TTM 3654R1 would subdivide the 249.39-acre property to provide for 144 residential lots on 45.75 acres to accommodate up to 276 dwelling units (including 93 single-family detached housing units on minimum 7,200 s.f. lots, three custom single-family lots, 104 eight-cluster single-family detached housing units, and 77 fourcluster single-family detached housing units); open space, drainage, and HOA-maintained slopes on 171.06 acres; public streets on 19.66 acres; pump stations/tank sites on 1.50 acres; three public parks on 9.25 acres; and five private parks on 2.17 acres.

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Figure 7 Revision No. 1 to Tentative Tract Map No. 36544

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Table 2 Revision No. 1 to TTM 36544 Statistical Summary Lot Nos. Land Use Acreage Dwelling Units
1 through 144 Residential 45.75 276
A-D, H, J, L, N-O, Q, S-T, VFF, HH-SS, and UU-WW Open Space/Drainage/HOA Maintained Slopes 171.06 0 Streets “A” through “T” Public Streets 19.66 0
G, M, P, and R Pump Station/Tank Site 1.50 0
F, I, and K Public Parks 9.25 0
E, U, GG, TT, and XX Private Parks 2.17 0
Totals: 249.39 276
In comparison to the approved TTM 36544, TTM 36544R1 would result in a reduction in the number of dwelling units by 16 dwelling units (from 292 dwelling units to 276 dwelling units). Areas planned for physical disturbance would be substantially reduced, as TTM 36544 included disturbances to approximately 170.70 acres of the site, while TTM 36544R1 would include disturbances to only 151.8 acres of the property. In general, areas proposed for physical disturbance by TTM 36544R1 mostly would occur within the limits of disturbance identified by TTM 36544. In addition, the proposed Project would result in a substantial reduction in the amount of grading proposed on site. Specifically, the Approved Project required 5.01 million cubic yards (cy) of cut and 4.93 million cy of fill with 421,805 cy of soil import, while the proposed Project would require 4.14 million cy of cut and 4.36 million cy of fill, with 215,000 cy of raw fill and 11,000 cy of adjusted fill. Consistent with the project evaluated in the SHP EIR, the proposed Project likely would require blasting during grading activities as it is likely that ledges and zones of extremely hard rock may be encountered.

1.4 Prior Environmental Documentation
The Skyline Heights Project (SHP) was approved by the City of Corona (“City”) City Council on February 1, 2017 (herein, “Approved Project”), at which time the City Council also certified the Skyline Heights Environmental Impact Report (herein, “prior EIR”; SCH No. 2014021003).

Richland Ventures previously applied to the City of Corona for certain land use entitlements necessary to develop 292 single-family residences on an approximately 270.9-acre site within an undeveloped hillside area to the south/southwest of the Foothill Parkway Westerly Extension. At the time the Skyline Heights EIR was prepared, the site was located within the City of Corona Sphere of Influence (SOI) in unincorporated Riverside County. In order to facilitate development of the Foothill Parkway Westerly Extension, the Applicant proposed the annexation of the Project site and surrounding parcels totaling approximately 294.8 acres to the City of Corona, and therefore the City of Corona was the lead agency for the Approved Project. The Approved Project involved the review of Tentative Tract Map 36544 for the development of the 292 single-family homes. In order to facilitate the development of the residential subdivision, the following entitlements were necessary:
• Annexation 117: Application for annexation of 394.8 acres from unincorporated Riverside County in the City of Corona’s southwest Sphere of Influence (SOI) to the City of Corona. The northernmost portion of the annexation (identified as Property 1) is located south of Green River Road where it intersects with Paseo Grande, and the southernmost portion of the annexation (identified as Property 2) is located generally south of the westerly extension of Foothill Parkway, and west of Trudy Way.

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• General Plan Amendment No. GPA13-003: General Plan Amendment to change 357.14 acres from Rural Residential I (0.2-0.5 dwelling units/acre) to Low Density Residential (3-6 du/ac) and 37.61 acres to Open Space located generally south of the westerly extension of Foothill Parkway, east of Paseo Grande and west of Trudy Way.
• Change of Zone No. CZ13-002: Application to pre-zone 37.61 acres to Open Space, 86.23 acres to Agriculture, and 270.9 acres to R-1-7.2 (Single Family Residential, 7,200 square foot minimum lot size) located generally south of the westerly extension of Foothill Parkway, east of Paseo Grande and west of Trudy Way.
• Tentative Tract Map No. 36544: Application to subdivide approximately 271 acres into 292 single family residential lots and lettered lots for open space and landscaping located generally south of the westerly extension of Foothill Parkway, east of Paseo Grande and west of Trudy Way. The shaded area of Property 2 is the location of TTM 36544.

A Draft EIR for the Approved Project was made available for public comment beginning on 12/4/2015 and ending on 1/19/2016. The Draft EIR for the Approved Project was recirculated and made available for public comment beginning on 11/16/2016 and ending on 12/30/2016. The Draft EIR was recirculated to include additional information and analysis on biological resources on the Project site, as well as the potential impacts to such resources from implementing the project. Revised mitigation measures were identified and included to address the biological impacts considered potentially significant. The Final EIR was certified by the City of Corona City Council in conjunction with its approval of the above applications on February 1, 2017.

1.5 Basis for an Addendum
The CEQA Guidelines allow for the updating and use of a previously-certified EIR for projects that have changed or are different from the previous project or conditions analyzed in the certified EIR. In cases where changes or additions occur with no new or more severe significant environmental impacts, the Lead Agency is required to prepare an Addendum to a previously certified EIR. See CEQA Guidelines § 15164. The following describes the requirements of an Addendum, as defined by CEQA Guidelines § 15164:
a. The lead agency or responsible agency shall prepare an Addendum to a previously certified EIR if some changes or additions are necessary but none of the conditions described in § 15162 calling for preparation of a Subsequent EIR have occurred.
b. An Addendum to an adopted negative declaration may be prepared if only minor technical changes or additions are necessary or none of the conditions described in § 15162 calling for the preparation of a subsequent EIR or negative declaration have occurred.
c. An Addendum need not be circulated for public review but can be included in or attached to the Final EIR. d. The decision-making body shall consider the Addendum with the Final EIR prior to making a decision on the project.

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e. A brief explanation of the decision not to prepare a Subsequent EIR pursuant to § 15162 should be included in an Addendum to an EIR, the lead agency’s findings on the project, or elsewhere in the record. The explanation must be supported by substantial evidence.

As noted above, CEQA Guidelines § 15164(a) and (b) allow for the preparation of an Addendum if none of the conditions described in § 15162 are met. CEQA Guideline § 15162 describes the conditions under which a Subsequent EIR must be prepared, as follows:
a. When an EIR has been certified or a negative declaration adopted for a project, no subsequent EIR shall be prepared for that project unless the lead agency determines, on the basis of substantial evidence in the light of the whole record, one or more of the following:

1. Substantial changes are proposed in the project which will require major revisions of the previous EIR due to the involvement of environmental effects or a substantial increase in the severity of previously identified significant effects;

2. Substantial changes occur with respect to the circumstances under which the project is undertaken, which will require major revisions of the previous EIR due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects; or

3. New information of substantial importance, which was not known and could not have been known with the exercise of reasonable diligence at the time the previous EIR was certified as complete, shows any of the following:
a. The project will have one or more significant effects not discussed in the previous EIR; b. Significant effects previously examined will be substantially more severe than shown in the previous EIR;
c. Mitigation measures or alternatives previously found not to be feasible would in fact be feasible, and would substantially reduce one or more significant effects of the project, but the project proponents decline to adopt the mitigation measure or alternatives; or d. Mitigation measures or alternatives which are considerably different from those analyzed in the previous EIR would substantially reduce one or more significant effects on the environment, but the project proponents decline to adopt the mitigation measure or alternative. (See CEQA Guidelines § 15162)
b. If changes to a project or its circumstances occur or new information becomes available after adoption of a negative declaration, the lead agency shall prepare a subsequent EIR if required under subdivision (a).

Otherwise, the lead agency shall determine whether to prepare a subsequent negative declaration, an addendum, or no further documentation.
c. Once a project has been approved, the lead agency's role in project approval is completed, unless further discretionary approval on that project is required. Information appearing after an approval does not require reopening of that approval. If after the project is approved, any of the conditions described in subdivision (a) occurs, a subsequent EIR or negative declaration shall only be prepared by the public agency which grants the next discretionary approval for the project, if any. In this situation no other responsible

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agency shall grant an approval for the project until the subsequent EIR has been certified or subsequent negative declaration adopted.
d. A subsequent EIR or subsequent negative declaration shall be given the same notice and public review as required under Section 15087 or Section 15072. A subsequent EIR or negative declaration shall state where the previous document is available and can be reviewed.

If none of the circumstances listed above occur and only minor technical changes or additions are necessary to update the previously approved/certified CEQA document, an Addendum shall be prepared (See CEQA Guidelines § 15164(a)). As described in detail in the Initial Study provided herein in Section 2.0, Environmental Checklist, none of the above circumstances that warrant the preparation of a Subsequent EIR are present.

1.6 Mitigation Measures
Below is a list of mitigation measures provided in the SHP EIR. Because construction for the Project has yet to commence, the majority of the mitigation measures from the previously certified EIR are still relevant. Any modifications to mitigation measures are shown in strikeout/underline format in the table below.

Mitigation No. Mitigation Measure/Implementing Action
Biological Resources
BIO-MM1 Biological Monitor/BMPs. The project impact areas and avoidance areas shall be flagged or fenced prior to clearing to prevent incursion into unsurveyed or avoided areas. A qualified biological monitor(s) shall monitor work activities during the initial clearing and grading phase of construction (including any ground or vegetation disturbance, demolition, fence installation, grading of existing roads, material delivery, etc.). The monitoring biologist shall ensure the flagging or fencing remains intact and no incursions into avoided areas occurs. The monitoring biologist shall examine each area of impact as the clearing/grading operations move into an uncleared native habitat area or into any area that has had a lapse in construction for more than 30 days to ensure no sensitive wildlife species are present. The biologist shall inspect debris piles, pipes, burrows, vegetation, leaf litter piles, and other potential refugia for sensitive wildlife species prior to initiation of clearing, grubbing, grading, or any other Project activity that may injure or kill sensitive wildlife species.

If wildlife is discovered, the biological monitor shall take appropriate action as defined in the mitigation measures, permit conditions, and regulations. The biological monitor may move wildlife or humanely encourage it to move out of harm’s way, if safe and feasible and permitted to do so.

Potential day roosts for pallid bat (e.g., caves, crevices, mines, hollow trees, buildings, etc.) shall be inspected by a qualified bat biologist prior to initial ground disturbance. If bats are roosting, a bat exclusion plan shall be prepared and submitted to CDFW for review prior to impacts. If a colony is discovered during the breeding season (March 1 -October 1), the biologist shall determine appropriate avoidance measures, including, but not limited to sound walls, buffers, and Project phasing/timing, to prevent disturbance to the colony until all young are weaned and capable of foraging independently.

Monitoring and survey activities shall be documented on a daily basis. All monitoring reports and communications shall be retained in Project files to allow review by the City of Corona, CDFW, and USFWS, if requested.

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BIO-MM2 Special Status Botanical Species. Mitigation shall be provided forThe following measures shall apply to address and minimize potential impacts to Coulter’s matilija poppy, intermediate mariposa lily, and chaparral nolina to the extent feasible.
 Impacts shall be minimized and avoided to the extent feasible. Prior to commencement of ground-disturbing activities (i.e., clearing and grading), Coulter’s matilija poppy and intermediate mariposa lily plants within the development footprint shall be salvaged for use in the Project area, avoidance area, or reuse in local restoration projects. In addition, a qualified botanist shall collect seeds from plants within the grading impact area during the spring or summer before grading commencement.
 Prior to commencement of ground-disturbing activities (i.e., clearing and grading), Iimpacts to chaparral nolina shall be mitigated through translocation and seed collection with propagation to an on-site or off-site preserved property acceptable to the City. Prior to any ground disturbance, the Applicant shall prepare a Chaparral Nolina Planting Plan (Plan) for chaparral nolina. The property shall be composed of habitat characteristics suitable to support chaparral nolina, including but not limited to: appropriate soils, elevation, and supporting chaparral or coastal sage scrub (or a combination thereof) habitat. The property shall be conserved via recordation of a conservation easement or deed restriction in favor of a California Department of Fish and Wildlife (CDFW)-due diligence approved local conservation entity to protect chaparral nolina on the property in perpetuity. Alternatively, the land may be transferred in fee title to a CDFW-approved local conservation entity. A management fund shall be established by the Applicant and will consist of an interest-bearing account with the amount of capital necessary to generate sufficient interest and/or income to fund all monitoring, management, and protection of the conservation area(s), including but not limited to, reasonable administrative overhead, biological monitoring, invasive species and trash removal, signage replacement and repair, law enforcement measures, long-term management reporting (as described below), and other actions designed to maintain and improve the habitat of the conserved land(s), in perpetuity.
 Prior to commencement of ground-disturbing activities, a Property Analysis Record, or substantially equivalent analysis, shall be conducted by the Applicant and approved by the City to determine the management needs and costs described above, which then will be used to calculate the capital needed for the management of the fund. This management fund shall be held and managed by a CDFW-approved local conservation entity. To protect the mitigation area(s), the Project Applicant shall place appropriate signage around the perimeter of each site.

Except for uses appropriate to a habitat conservation area, the public shall not have access to the mitigation area(s), and no activities shall be permitted within the mitigation areas, except maintenance of habitat, including the removal of nonnative plant species, trash, and debris, and the installation of native plant materials. Prior to any ground disturbance, the Applicant shall prepare a Chaparral Nolina Planting Plan (Plan) for chaparral nolina. The Plan shall require a replacement ratio of 1:1 by area, and ensure a minimum 90 percent survivorship at the end of a five-year monitoring period, which shall be verified by the monitoring biologist (minimum qualifications of the monitoring biologist are specified below). At a minimum, the five-year plan shall include the following information:

1. a description of the existing conditions of the receiver site(s) characterizing the suitability of the site(s) for chaparral nolina, and documenting the acreage of the site,

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2. a description of how the site will be preserved in perpetuity, e.g., conservation easement, deed restriction, etc., and the name of the CDFW-approved due diligence entity that will hold the easement/deed restriction, etc.,

3. qualifications of the monitoring biologist. At a minimum the monitoring biologist will possess a minimum of five-year's experience conducting habitat restoration projects in coastal sage scrub and/or chaparral habitat in Riverside County, California,

4. receiver site preparation for transplanting,

5. goals for success,

6. schedule,

7. propagation techniques,

8. transplant and seedling installation methods,

9. plant spacing,

10. performance criteria for success, including provision for control of non-native and invasive species,

11. monitoring and reporting procedures for each of the five years of the monitoring period,

12. adaptive management strategies, including a contingency plan should the site fail to meet the specified success criteria, and

13. maintenance requirements that will be reviewed and approved by the City. The Plan shall also ensure a mixture of both male and female plants.

BIO-MM3 Compensation Parcel. Prior to issuance of a grading permit, the project Applicant shall preserve a minimum of ten (10) acres (a 1:1 ratio) of natural habitat, which shall be biologically equivalent or superior to the Public/Quasi-Public (PQP) land the project site surrounds, and shall be located adjacent to USFS land. The compensation parcel shall either be:

1. Deeded in fee title to the United States Forest Service (USFS) or Western Riverside County Regional Conservation Authority (RCA) to ensure appropriate protection and permanent habitat management in perpetuity, or

2. Conserved via recordation of a conservation easement or deed restriction in favor of a CDFWdue diligence approved local conservation entity.

BIO-MM4 Designate Unimpacted Areas as Open Space. Prior to recordation of Final Maps for each phase of the proposed development, Tthose areas of the project site not impacted by the project footprint, including Riparian/Riverine and excluding the minimum 10-acre preservation area identified in BIOMM3, shall be conserved in perpetuity via the recordation of a conservation easement or deed restriction in favor of a CDFW-approved local conservation entity; or transferred in fee title to a CDFW-approved local conservation entity. The avoided Riparian/Riverine areas shall be conserved prior to issuance of a grading permit. The CDFW-approved local conservation entity shall manage the conservation areas to protect the long-term conservation, functions and values in-perpetuity.

BIO-MM5 Other Species to Avoid in Landscaping. Prior to issuance of grading permits, building permits, and/or road improvement plans, the Project Applicant shall prepare a landscape plan for review and approval by the City of Corona The landscape plan shall prohibit the use of The project Applicant shall add more common cultivar forms of Coulter’s matilija poppy to the list of plants to be avoided in site landscaping, including White Cloud matilija poppy. Additional non-native plants to be

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avoidedthat shall not be planted within any onsite mitigation or landscaping include coyote brush (Baccharis pilularis) and fourwing saltbush (Atriplex canescens). In addition, the landscape plan shall exclude those species identified in Table 6-2, Plants that Should be Avoided Adjacent to the MSHCP Conservation Area, of the Western Riverside County Multiple Species Habitat Conservation Plan (MSHCP). To ensure these non-native plants are not used in landscaping within the project site, the project Applicant shall include a list of plant species to avoid within the CC&Rs for the development.

The project applicant shall also develop and distribute a suitable homeowner education package to residents / new owners covering the species to avoid.

BIO-MM6 Oak Tree Replacement. The project Applicant shall replace oak trees impacted by the project at a ratio consistent with the City of Corona oak tree conservancy policy (10.10.5), at no less than a 2:1 ratio. Replacement trees shall be located in undeveloped natural areas suitable to support these trees or in onsite mitigation areas where possible. If spacing requirements limit the number of replacement trees in these areas additional plantings may be located in landscaped areas as close to open space as feasible. All replacement trees shall be planted prior to issuance of the Certificate of Occupancy.

BIO-MM7 Riparian/Riverine. Prior to issuance of a grading permit, the project Applicant shall provide mitigation for ±10.5107 acres of Riparian/Riverine impacts at no less than a 2:1 basis, as determined through consultation with the City of Corona and wWildlife aAgencies based on their approval of the Determination of Biologically Equivalent or Superior Preservation (“DBESP”; see SHP EIR Addendum No. 1 Technical Appendix D2) that provides a functions and values analysis pursuant to the requirements of the MSHCP. The project Applicant proposes mitigation in the form of offsite mitigation with the Riverside-Corona Resource Conservation District (RCRCD) or other suitable approved organization with available credits. Currently, mitigation in banks is favored to preserve large areas of habitat where it is needed to fulfill the conservation goals of the MSHCP. In the event mitigation with the RCRCD is not finalized for any reason, the project Applicant shall provide equal or greater value mitigation in one or more of the following forms: offsite acquisition and preservation, participation in an approved mitigation bank, onsite creation, offsite creation, enhancement, or reestablishment. If offsite mitigation is incorporated, the preferred choice shall be to find mitigation within or adjacent to the Santa Ana Watershed and in or adjacent to Corona if possible. In addition, some avoided resources within the open space areas shall be preserved to the extent feasible pursuant to a in an open space area and deed restrictioned or other appropriate legal mechanism to prevent future development.

If onsite mitigation is proposed as an alternative mitigation, the project Applicant shall prepare a Habitat Mitigation and Monitoring Plan (HMMP) shall be developed and provided for review and approval by local and regulatory agencies, which and shall include at a minimum the following components:
• Quantitative success criteria (vegetation cover and species richness); • Recommendations for soil preparation;
• A plant palette to include native species occurring on the site, such as coast live oak and Coulter’s matilija poppy;
• Planting methods;
• Irrigation and maintenance requirements; and
• A long-term mitigation maintenance and monitoring plan with remedial measures.

BIO-MM8 Storm Water Pollution Prevention Plan. Prior to the first ground disturbance issuance of a grading permit, the project Applicant shall prepare and implement a Storm Water Pollution Prevention Plan or for City of Corona review and approval of a Stormwater Pollution Prevention Plan (SWPPP), which

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shall identify all standard best management practices (BMPs) to prevent discharges from entering avoided jurisdictional drainages WoUS during construction. The required SWPPP shall at a minimum include BMPs shall that include but are not be limited to:
• Use of erosion control or sedimentation prevention methods, such as fiber rolls, sand bags, rice mats, straw wattles, or similar measures, where appropriate; and • Proper use and disposal of oil, gasoline, diesel fuel, antifreeze, and other toxic substances will be enforced.

Compliance with the City-approved SWPPP shall be required as a condition of grading permit approval, compliance with the SWPPP shall be required by bid documents issued to prospective construction contractors, and the Project construction contractors shall permit periodic inspection of the construction site by City of Corona staff or its designee to confirm compliance during all construction activities.

BIO-MM9 Regional Water Quality Control Board Permit. Prior to the issuance of a grading permit, to mitigate for the loss of 1.4857 acres and temporary loss of ±0.25-acre of State waters regulated by nonwetland WoUS due to project construction, project Applicant shall enter into an agreement with the U. S. Army Corps of Engineers (via issuance and implementation of a Nationwide permit or Individual permit) and with the California Santa Ana Regional Water Quality Control Board (via issuance and implementation of a Clean Water Act [CWA] Section 401 Certification) to replace permanentlyimpacted State waters as specified by the agreement with RWQCB affected WoUS and wetlands at a ratio specified by the U. S. Army Corps of Engineers and California Regional Water Quality Control Board, but at not less than a 2:1 basis, through offsite acquisition and preservation, participation in an approved mitigation bank, and/or on or offsite creation, enhancement, or reestablishment of WoUS State waters or a combination of these options. Temporary impacts to RWQCB State waters shall be mitigated through on-site restoration within the temporarily impacted areas or as otherwise specified by the CWA Section 401 certification. The exact ratio shall be based on a functions and values assessment included in the Project’s Determination of Biologically Equivalent or Superior Preservation (“DBESP”; see SHP EIR Addendum No. 1 Technical Appendix D1) and pursuant to RWQCB’s approval. Preparation of a Habitat Mitigation and Monitoring Plan (HMMP) outlining the details of the mitigation shall be required for any on-site mitigation or off-site mitigation on lands not already subject to an RWQCB-approved HMMP.

BIO-MM10 California Department of Fish and Wildlife Permit. Prior to the issuance of a grading permit, to mitigate for the loss of ±10.5107 acres of streambed and wetlands and the temporary loss of ±1.13 acres of streambed due to project construction, the project Applicant shall enter into an agreement with the California Department of Fish and Wildlife (CDFW) via issuance and implementation of a Section 1600 Streambed Alteration Agreement , Section 1600) to replace affected streambed at not less than a 2:1 basis (mitigation:impact) for permanent impacts and restoration of temporarily impacted areas to their existing/former condition, as specified by the California Department of Fish and Wildlife, through a combination of offsite acquisition and preservation, participation in an approved mitigation bank, and/or on or offsite creation, enhancement, or reestablishment of the streambed. The exact ratio shall be based on a functions and values assessment pursuant to CDFW’s approval of the required Streambed Alteration Agreement. Preparation of a Habitat Mitigation and Monitoring Plan (HMMP) outlining the details of the mitigation shall be required for on-site mitigation or off-site mitigation on lands not already subject to a CDFW-approved HMMP.

BIO-MM11 Nesting Birds. To prevent impacts to sensitive, migratory, and nesting birds (including raptors), clearing, or other work in native habitats, should shall be avoided during the critical nesting period

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of January 1 – September 1. If work cannot be avoided during this timeframe, a nesting bird survey shall be conducted by a qualified biologist within three (3) days prior to initiation of clearing and/or grading. A letter report documenting the clearance survey and its results shall be provided to the City of Corona prior to any disturbance to the Project site. If nesting birds are present, a nesting bird plan will shall be developed and implemented and to include appropriate measures to mitigate potential impacts, including maintaining a buffer area until fledging has occurred. Active bird nests should shall be mapped utilizing a hand-held global positioning system (GPS) (getting as close as possible without disturbing the nest) and a buffer will be flagged around the nest (typically 300 feet for most species, 500-foot buffer for raptor nests), as determined appropriate by the biologist. Construction should not be permitted within the buffer area while the nest continues to be active (eggs, chicks, etc.).

Once fledging has occurred no further avoidance is required.

BIO-MM12 Burrowing Owl. A pre-construction burrowing owl clearance survey shall be conducted by an experienced burrowing owl qualified biologist no more than 30 days before earth disturbance (construction). The survey will be conducted as close to the actual construction initiation date as possible. A letter report documenting the clearance survey and its results shall be provided to the City of Corona prior to any disturbance to the Project site and prior to commencement of grading activities. If owls are present, the project biologist will shall consult with local and state agencies, as appropriate, and develop a mitigation plan. Mitigation will be based on the following goals and requirements included in the MSHCP:

1. If the site contains or is part of an area supporting less than 35 acres of suitable habitat or the survey reveals that the site and the surrounding area supports fewer than three (3) pairs of burrowing owls, the onsite burrowing owls will be passively or actively relocated following accepted protocols.

2. Occupied nests shall be avoided during the nesting season (February 1 – August 31) and a buffer of 300 to 500 feet shall be employed, depending on the level of disturbance surrounding the burrow.

3. Burrow exclusion shall be utilized outside of the nesting season by installing a one-way door in burrow openings. The burrow shall be closed following verification burrows are empty (through site monitoring and scoping).

4. If the site (including adjacent areas) supports three (3) or more pairs of burrowing owls, supports greater than 35 acres of suitable habitat, and is non-contiguous with MSHCP Conservation Area lands, at least 90 percent of the area with long-term conservation value and burrowing owl pairs will be conserved onsite.

BIO-MM13 AMountain Lion Program. Prior to issuance of a grading permitthe first Certificate of Occupancy for each phase of development, a mountain lion (Puma concolor) program shall be developed by the project Applicant for City review and approval in an effort to reduce likelihood of human-lion conflicts. The program shall include the following components:

1. A suitable homeowner education package for distribution to residents / new owners;

2. A suitable road sign program warning of the presence of mountain lions and the need for reduced speeds and increased caution;

3. A suitable CC&R provision limiting unsupervised outdoor pets and pet feeding practices that may encourage mountain lions to enter residential yards in search of food; and

4. A suitable mountain lion safety plan.

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The Project’s CC&Rs shall include a provision specifically requiring future homeowners to comply with the requirements of the Mountain Lion Program.Compliance with the mountain lion program shall be made a condition of grading and building, and an appropriate provision shall be included in the Project’s CC&Rs.

BIO-MM14 A qualified biologist shall monitor clearing and grubbing activities as they impact vegetation on the site. A qualified biologist shall inspect debris piles, pipes, burrows, vegetation, leaf litter piles, and other potential refugia for sensitive wildlife species prior to initiation of clearing, grubbing, grading, or any other project activity that may injure or kill sensitive wildlife species. If wildlife is discovered, the qualified biologist shall move it out of harm’s way or allow it to move safely out of the work area prior to initiation of project activities.

Potential day roosts for pallid bat (e.g., caves, crevices, mines, hollow trees, buildings, etc.) shall be inspected by a qualified bat biologist prior to initial ground disturbance. If bats are roosting, a bat exclusion plan shall be prepared and submitted to CDFW for review prior to impacts. If a colony is discovered during the breeding season (March-October), the biologist shall determine appropriate avoidance measures, including, but not limited to sound walls, buffers, and project phasing/timing, to prevent disturbance to the colony until all young are weaned and capable of foraging independently.

BIO-MM15 Homeowner Education Package (Invasive Species). Prior to issuance of occupancy permits, the Project Applicant shall develop for review and approval by the City of Corona, a homeowner education package providing and informing future occupants that the list of plant species identified in Mitigation Measure BIO-5 are prohibited and may not be planted on any individual lot. The homeowner education package also shall include a list of recommended non-prohibited plant species. A copy of the City-approved homeowner education package shall be provided to future owners/tenants as part of all future lease/sales agreements. Design guidelines for the proposed project shall provide the new homeowners with a list of native landscaping materials permitted within the development area. These materials have been selected for their contribution to the project theme, adaptability to local climatic and soil conditions, and for their compatibility with the unique natural environment in the area. None of the plants listed in Section 6.1.4 of the MSHCP will be utilized in the development and their use by future homeowners will be prohibited. The MSHCP has identified invasive plants that should be removed from open space areas. This list is included in Table 6-2 of the MSHCP and in Appendix C, and shall be included in the CC&Rs prepared for the subdivision.

BIO-MM16 Invasive Vegetation Control – Heavy Equipment. All heavy equipment used onsite shall be washed, particularly the wheels and under carriage, prior to bringing it onto the project site from other construction sites to prevent the spread of weedy species.

BIO-MM17 Invasive Vegetation Control – Staging Areas. Staging areas shall be placed in areas that have been previously disturbed or have degraded habitat within the project footprint but do not show an infestation of non-native species. Staging areas shall be maintained in a weed/noxious weed-free condition.

BIO-MM18 All refuse created or brought onsite by clearing personnel or contractors shall be placed in covered containers, removed from the site daily, and disposed of properly.

BIO-MM19 Field crews shall maintain the speed limit on posted roads and limit vehicle/truck speeds on unpaved surfaces to 15 miles per hour or less.

BIO-MM20 Urban/Wildlands Interface. Prior to issuance of grading or building permits, the City of Corona shall review the grading/building plans to ensure that measures Applicant shall ensure that the grading and building plans have incorporated the measures to meet the requirements of the The proposed

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project shall incorporate measures to meet MSHCP Urban/Wildlands Interface guidelines and requirements (see MSHCP Volume I, Part 2 of 2, subsection 6.1.4) with respect to These measures will address Drainage, Toxics, Lighting, Noise, Barriers, Access, Pets, and Grading/Land Development (See Section 9.5 of the BRA Report included in Appendix D to this Draft EIR).

BIO-MM21 Crotch’s Bumble Bee. In the event the Crotch’s bumble bee (Bombus crotchii) status is listed as candidate, threatened or endangered by the CDFW at the time of construction, the following measures shall be implemented.
• Clearing/ground-disturbing activities shall be prohibited from February 1 through September 30 within suitable habitat for the Crotch’s bumble bee. As part of this requirement, if construction is proposed during this period, a qualified biologist shall go out and mark all of the suitable habitat on site, which must be avoided and fencing provided around any accessible areas until at least September 30. A letter report documenting the actions performed and completion of this measure shall be provided to the City of Corona prior to any disturbance of the Project site. Construction activities may commence in areas outside of suitable habitat for the bee.
• For construction between October 1 and January 31, a pre-construction survey is required within suitable habitat to confirm that no nests occur on site. Should any nests be identified, the Project biologist shall consult with CDFW to determine if permits are required. Clearance within that portion of the property determined by the biologist to support a nest and a suitable buffer shall be avoided until consultation with the CDFW determines activities can resume or the site is no longer occupied. If the pre-construction survey identifies no nests, then construction activities may proceed as normal. A letter report documenting the actions performed and completion of this measure shall be provided to the City of Corona prior to any disturbance of the Project site. If consultation with the CDFW is required a second letter report shall be provided documenting the CDFW determination, requirements and approval prior to moving forward with construction activities on that portion of the Project site. • Pesticides considered harmful to the Crotch bumble bee shall be prohibited during construction.

BIO-MM22 Workers Environmental Awareness Program. All persons employed or otherwise working on the Project site during the vegetation clearing and grading phase of construction shall attend a Workers Environmental Awareness Program (WEAP) training. All workers must attend WEAP training prior to performing any work on-site. The WEAP shall consist of a presentation (either provided in person by the biological monitor or a recorded training session) that includes a discussion of the biology of the habitats and species that may be present at the site. The WEAP shall also include information about the special-status plant and wildlife species that may be present, legal protections for those species, penalties for violations, and mitigation measures. The WEAP shall include but not be limited to burrowing owl, nesting birds, and other special-status species. The WEAP shall also include information on weed control practices, appropriate trash disposal, fire prevention and procedures for smoking, spill prevention and procedures, jurisdictional waters and SWPPP, BMPs, biological monitors and compliance responsibilities, and other issues such as pets, firearms, etc. Attendance at training shall be documented and construction workers provided with a hardhat sticker. Supporting materials shall be provided to all personnel during the training program, including contact information for the biological monitor and/or other compliance personnel. Informal or formal refresher training shall be conducted as needed to maintain compliance.

BIO-MM23 Restoration. Prior to final grading inspection, temporary impact areas associated with the haul road required during site mass grading activities shall be restored to its former condition.

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BIO-MM24 Invasive Species Restrictions and CC&Rs. Prior to issuance of occupancy permits, the Project Applicant shall provide the City of Corona with a copy of the Project’s Codes, Covenants, and Restrictions (CC&Rs). The Project CC&Rs shall explicitly prohibit the planting of the non-native plant species identified by Mitigation Measure BIO-5.

PDF BIO-1 Drainage. The project incorporates project streets, open channels and natural drainage courses as well as a comprehensive system of underground storm drains to handle storm runoff from the project site. Storm water from the project site and off-site areas will be directed to storm drains. The design and operation of the drainage channel shall be adequate to preclude discharge of water into open space areas that are of lower quality or higher quality than current conditions. The proposed development shall incorporate measures, including measures required through the NPDES requirements, to ensure that the quantity and quality of runoff discharged to the open space area is not altered in an adverse way when compared with existing conditions. In particular, measures shall be put in place to avoid discharge of untreated surface runoff from developed and paved areas into open space areas. Stormwater systems shall be designed to prevent the release of toxins, chemicals, petroleum products, exotic plant materials, or other elements that might degrade or harm biological resources or ecosystem processes within open space areas. This will be accomplished using a variety of methods including natural detention basins, grass swales, or mechanical trapping devices. Regular maintenance shall occur to ensure effective operations of runoff control systems.

PDF BIO-2 Toxics. The proposed project is designed to utilize natural drainage patterns for the flow of surface water. Water Quality Best Management Practices (BMPs) include education, storm drain stenciling, and street sweeping in compliance with the City of Corona’s requirements. The earthen channel shall be signed to filter potential toxics in the storm water prior to its discharge into open space areas.

These BMPs will be implemented as part of the storm water pollution prevention measures for the project, in accordance with all appropriate NPDES requirements. The project would result in the additional use of hazardous materials in limited quantities associated with normal residential use such as cleaning products, solvents, herbicides, and insecticides. However, compliance with regulations will reduce the potential risk of hazardous material exposure to a level that is less than significant. An information pamphlet has been prepared for each homeowner regarding the use of toxics.

PDF BIO-3 Lighting. Outdoor lighting of residences will be designed so that all direct beams would be confined to dwelling sites. Project lighting will not intrude into the open space conservation areas. Street lighting, parking lot lighting, and other project-related illumination sources will be positioned, directed, and shielded so as to avoid “light spill” into the conserved areas. The proposed project will avoid any night lighting adjacent to the open space areas. Night lighting will not be used during the course of construction unless absolutely necessary. If necessary, the lights will be directed and shielded to minimize lighting of the surrounding habitat. The level of off-site lighting and lighting fixtures would comply with the applicable requirements and policies of the City of Corona.

PDF BIO-4 Noise. The proposed project incorporates landscape elements including trees, shrubs, and groundcover, which will assist in noise reduction on the project site. In addition, a noise analysis prepared for the project found that no proposed on-site or surrounding sensitive land uses would experience long-term noise levels in excess of 65 dBA during the daytime hours under build-out of the proposed project. This daytime noise level would not result in exterior nighttime levels greater than 45 dBA. Therefore, no noise created on the project site would exceed residential noise standards.

PDF BIO-5 Invasives. Exotic Vegetation Control – Design guidelines for the project will provide the homeowners with a list of native landscaping materials permitted within the project site. These materials have been selected for their contribution to the project theme, adaptability to local climatic and soil

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conditions, and for their compatibility with the unique natural environment in the project site. The MSHCP has identified exotic invasive plants that should be areas avoided adjacent to the MSHCP Conservation Area in Table 6-2, Section 6.1.4 of the MSHCP; none of these plants will be utilized for the proposed project and their use by future homeowners will be prohibited.

PDF BIO-6 Barriers. The proposed project will include theme walls along project perimeter streets adjacent to public streets, and will include walls and fencing located where public view and/or important interfaces are of concern. The proposed project will incorporate special edge treatments designed to separate development areas from open space areas. These areas of native landscaping and fencing will serve to minimize unauthorized public access, domestic animals predation, and illegal trespass and dumping. Exclusion fencing will be permanently placed where development abuts avoided and adjacent open space areas. The exclusion fence will be a minimum of eight feet in height and will be installed and maintained for the purposed of controlling human and pet access (cats and dogs) into the open space area and be in compliance with MSHCP requirements. The fencing will be permanent and will be maintained in perpetuity. Approval of the fencing design will be required by the City of Corona prior to project initiation.

PDF BIO-7 Access. Access points between native habitats and the project development will be posted with signage requesting residents to stay on the trails and not to disturb habitat. Yard fencing with no back gate will reduce access to native habitats adjacent to the project.

PDF BIO-8 Pets. Uncontrolled pets, feral dogs and cats can predate on native wildlife species. Appropriate signage will be posted requesting residents leash their pets. Homeowner Educational pamphlets will be used to inform them of the potential impacts by uncontrolled pets on native habitats and to request residents be good stewards of the land and prevent or limit their domestic cats from being allowed to openly hunt in the avoidance area.

PDF BIO-9 Grading/Land Development. All manufactured slopes associated with site development will be within the project site and there will be no impact to the MSHCP Conservation Area. All manufactured slopes that abut the natural open space will be retained as open space buffer zones.

All manufactured slopes and areas disturbed by construction of these slopes will be revegetated with appropriate non-invasive buffer species during project construction.

Cultural Resources
CR-1 Tribal Monitoring. Prior to the issuance of a grading permit the applicant shall contact the consulting Native American Tribe(s) that have requested monitoring through consultation with the City during the SB 18 process ("Monitoring Tribes”). The applicant shall coordinate with the Tribe(s) to develop individual Tribal Monitoring Agreement(s). A copy of the signed agreement(s) shall be provided to the City of Corona Planning Department prior to the issuance of a grading permit. The Agreement shall address the treatment of any known tribal cultural resources (TCRs) including the project's approved mitigation measures and conditions of approval; the designation, responsibilities, and participation of professional Tribal Monitors during grading, excavation and ground disturbing activities; project grading and development scheduling: terms of compensation for the monitors; and treatment and final disposition of any cultural resources, sacred sites, and human remains/burial goods discovered on the site per the Tribe(s) customs and traditions and the City’s mitigation measures/conditions of approval. The Tribal Monitor will have the authority to stop and redirect grading in the immediate area of a find in order to evaluate the find and determine the appropriate next steps, in consultation with the Project archaeologist.

If changes are made to the project footprint to include earth-moving activities in areas not previously studied, additional archaeological investigations shall be required.

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In the event that archaeological materials are discovered during construction, all earth-moving activity within and around the immediate discovery area shall be diverted until a qualified archaeologist can assess the nature and significance of the find, and, if necessary, develop appropriate treatment measures. Treatment measures typically include development of avoidance strategies, capping with fill material, or mitigation of impacts through data recovery programs such as excavation or detailed documentation. If during cultural resources monitoring the qualified archaeologist determines that the sediments being excavated are previously disturbed or unlikely to contain significant cultural materials, the qualified archaeologist can specify that monitoring be reduced or eliminated.

Native American monitors from affected Tribes shall observe all project-related grading activities, and the treatment of any recovered artifacts shall be carried out in accordance with the provisions of a Treatment Agreement between affected Tribes. The Treatment Agreement shall be executed by the consulting Tribes prior to the issuance of grading permits for each construction phase. All cultural materials that are collected during the grading monitoring program and from any previous archaeological studies or excavations on the project site shall be curated according to the current professional repository standards. The collections and associated records shall be transferred, including title, to an appropriate curation facility which meets the standards set forth in 36 CFR Part 79 for federal repositories. All sacred sites, should they be encountered within the project area, shall be avoided and preserved as the preferred mitigation.

If changes are made to the project footprint to include earth-moving activities in areas not previously studied, additional archaeological investigations shall be required.

CR-2 Archaeological Monitoring. At least 30-days prior to application for a grading permit and before any grading, excavation and/or ground disturbing activities on the site take place, the Project Applicant shall retain a Secretary of Interior Standards qualified and RPA-certified archaeological monitor to monitor all ground-disturbing activities in an effort to identify any unknown archaeological resources/TCRs and assist with avoidance, preservation and/or mitigation per the City's Mitigation Measures on known resources.

The Project Archaeologist in consultation with the Monitoring Tribe(s), the Developer and the City, shall develop a Cultural Resources Monitoring Plan (CRMP) to address the details, timing and responsibility of all archaeological and cultural activities that will occur on the project site. Details in the Plan shall include:
a. Project grading and development scheduling;
b. The Project archeologist and the Monitoring Tribe(s) shall attend the pre-grading meeting with the construction manager and any contractors and will conduct a mandatory Cultural Resources Worker Sensitivity Training to those in attendance. The Training will include a brief review of the cultural sensitivity of the Project and the surrounding area: what resources could potentially be identified during earthmoving activities; the requirements of the monitoring program: the protocols that apply in the event inadvertent discoveries of cultural resources are identified, including who to contact and appropriate avoidance measures until the find(s) can be properly evaluated; and any other appropriate protocols. All new construction personnel that begin work on the Project following the initial Training must take the Cultural Sensitivity Training prior to beginning work and the Project archaeologist and Monitoring Tribe(s) shall make themselves available to provide the training on an as-needed basis.

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c. The coordination of a monitoring schedule as agreed upon by the Monitoring Tribe(s), the Project archaeologist and the applicant;
d. The protocols and stipulations that the Developer. City, Monitoring Tribe(s) and Project archaeologist will follow in the event of inadvertent cultural resources discoveries, including any newly discovered cultural resource deposits that shall be subject to a cultural resources evaluation.

Prior to issuance of any grading permit, the Applicant shall retain a qualified vertebrate [sic] to develop a paleontological resource impact mitigation program (PRIMP) for excavations into the Upper Cretaceous Ladd Canyon Formation [sic], the Upper Cretaceous Williams Formation, ; and the Paleocene Silverado Formation. A qualified vertebrate paleontologist is defined as a paleontologist meeting the criteria established by the Society of Vertebrate Paleontology. The qualified vertebrate paleontologist shall conduct a preconstruction field assessment to locate fossils at surface exposures.

The qualified vertebrate paleontologist shall supervise a paleontological monitor who shall be present at such times as required by the paleontologist during construction excavations into the fossiliferous formations referenced above. Monitoring shall consist of visually inspecting fresh exposures of rock for larger fossil remains and, where appropriate, collecting wet or dry screened sediment samples of promising horizons for smaller fossil remains. The frequency of monitoring shall be determined by the paleontologist and shall be based on the rate of excavation and grading activities, the materials being excavated, and the depth of excavation, and if found, the abundance and type of fossils encountered. If resources are located, monitoring hours shall be increased if needed.

CR-3 Treatment and Disposition of Tribal Cultural Resources. In the event that Tribal Cultural Resources (TCRs) are inadvertently discovered during the course of grading for this Project and avoidance of the TCRs is not feasible, the following procedures will be carried out for treatment and disposition of the discoveries:

1. Temporary Curation and Storage: During the course of construction. All discovered resources shall be temporarily curated in a secure location onsite or at the offices of the project archaeologist. The removal of any artifacts from the project site will need to be thoroughly inventoried with tribal monitor oversight of the process; and

2. Treatment and Final Disposition: The landowner(s) shall relinquish ownership of all cultural resources, including all archaeological artifacts and non-human remains as part of the required mitigation for impacts to tribal cultural resources. Human remains, sacred/ceremonial items and burial good will be addressed per State Law. Mitigation Measure CR-1 and the Agreement required in Mitigation Measure CR-1. The applicant shall relinquish the artifacts as indicated below and provide the City of Corona Planning Division with evidence of same:
a. Professional curation, including a curation agreement with a qualified repository in Riverside County that meets federal standards per 36 CFR Part 79, and which shall be made available to all qualified researchers upon application. The collections and associated records shall be transferred, including title, to an appropriate curation facility within Riverside County, to be accompanied by payment of the fees necessary for permanent curation; b. At the completion of grading, excavation and ground disturbing activities on the site, a Phase IV Monitoring Report shall be submitted to the City Planning Division documenting monitoring activities conducted by the project Archaeologist and Native Tribal Monitors within 60 days of completion of grading. This report shall document the impacts to the

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known resources on the property; describe how each mitigation measure was fulfilled; document the type of cultural resources recovered and the disposition of such resources; provide evidence of the required cultural sensitivity training for the construction staff held during the required pregrade meeting; and, in a confidential appendix, include the daily/weekly monitoring notes from the archaeologist. All reports produced will be submitted to the City of Corona, Eastern Information Center and Monitoring Tribe(s).

If a potential fossil is found, the qualified vertebrate paleontologist or paleontological monitor shall be allowed to temporarily divert or redirect grading and excavation activities in the area of the exposed fossil, as determined appropriate by the monitor, to assess the significance of the find and, if necessary, develop appropriate treatment measures. Treatment measures may include avoidance or preservation in place, if feasible. If preservation or avoidance of the resource is not feasible, then the resource shall be removed from its location. Removal activities may consist of the relatively rapid removal of small isolated fossils from an active cut, to hand-quarrying of larger fossils from a bone bed over several days. These activities may include the assistance of the grading and excavation contractor’s equipment to facilitate removal. Any fossils encountered and recovered shall be prepared to the point of identification and catalogued before they are donated to their final repository. Any fossils collected shall be donated to a public, non-profit institution with a research interest in the materials, such as the Natural History Museum of Los Angeles County, San Bernardino County Museum, the John D. Cooper Archaeological and Paleontological Curation Center at the California Sate University, Fullerton, or Western Science Center in Hemet, California. Accompanying notes, maps, and photographs shall also be filed at the repository.

CR-4 Sacred Sites. All sacred sites, should they be encountered within the project area, shall be avoided and preserved as the preferred mitigation, if feasible. Prior to the release of the grading bond, the paleontologist shall prepare a report summarizing the results of the monitoring and salvaging efforts, the methodology used in these efforts, as well as a description of the fossils collected and their significance. The report shall be submitted by the Applicant to the Community Development Director or his/her designee for approval. In addition, the report shall be submitted to at least one of the repositories mentioned in Mitigation Measure CR-3 and other appropriate or concerned agencies to signify the satisfactory completion of the project and required mitigation measures.

CR-5 Discovery of Human Remains. In the event that human remains (or remains that may be human) are discovered at the project site during grading or earthmoving. the construction contractors, project archaeologist, and/or designated Native American Monitor shall immediately stop all activities within 100 feet of the find. The project applicant shall then inform the Riverside County Coroner and the City of Corona Planning Division immediately, and the coroner shall be permitted to examine the remains as required by California Health and Safety Code Section 7050.5(b). Section 7050.5 requires that excavation be stopped in the vicinity of discovered human remains until the coroner has made the necessary findings as to origin If human remains are determined to be Native American,, the applicant shall comply with the state law relating to the disposition of Native American burials that fall within the jurisdiction of the NARC (PRC Section 5097). The coroner shall contact the NAHC within 24 hours and the NAHC will make the determination of most likely descendant(s). The MLD shall complete his or her inspection and make recommendations or preferences for treatment within 48 hours of being granted access to the site. Treatment and disposition of the remains shall be determined in consultation with the most likely descendant(s) to determine the most appropriate disposition of human remains and any associated grave artifacts. In the event that the applicant and the MLD are in disagreement regarding the disposition of the remains. State law will apply and the mediation process will occur with the NAHC. if requested (see PRC Section 5097.98(e) and 5097.94(k)).

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The specific locations of Native American burials and reburials are confidential and may not be disclosed to the general public. The locations will be documented by the consulting archaeologist in conjunction with the various stakeholders and a report of findings will be filed with the Eastern Information Center (EIC). A Sacred Lands File form will be submitted to the NAHC by the project archaeologist and the Monitoring Tribe(s).

According to the California Health and Safety Code, six or more human burials at one location constitutes a cemetery (Section 8100), and disturbance of Native American cemeteries is a felony (Section 7052).

CR-6 Prior to issuance of any grading permit, the Applicant shall retain a qualified vertebrate paleontologist [sic] to develop a paleontological resource impact mitigation program (PRIMP) for excavations into the Upper Cretaceous Ladd Canyon Formation [sic], the Upper Cretaceous Williams and Ladd Formations (undifferentiated), the Early Pleistocene Very Old Alluvial Fan Deposits; the Upper Cretaceous Ladd Formation/Baker Canyon Conglomerate member; and Paleocene Silverado Formation. A qualified vertebrate paleontologist is defined as a paleontologist meeting the criteria established by the Society for Vertebrate Paleontology. The qualified vertebrate paleontologist shall conduct a pre-construction field assessment to locate fossils at surface exposures. The qualified vertebrate paleontologist shall supervise a paleontological monitor who shall be present at such times as required by the paleontologist during construction excavations into the fossiliferous formations mentioned above. Monitoring shall consist of visually inspecting fresh exposures of rock for larger fossil remains and, where appropriate, collecting wet or dry screened sediment samples of promising horizons for smaller fossil remains. The frequency of monitoring shall be determined by the paleontologist and shall be based on the rate of excavation and grading activities, the materials being excavated, and the depth of excavation, and if found, the abundance and type of fossils encountered. If resources are located, monitoring hours shall be increased as needed.

CR-7 If a potential fossil is found, the qualified vertebrate paleontologist or paleontological monitor shall be allowed to temporarily divert or redirect grading and excavation activities in the area of the exposed fossil, as determined appropriate by the monitor, to assess the significance of the find and, if necessary, develop appropriate treatment measures. Treatment measures may include avoidance or preservation in place, if feasible. If preservation or avoidance of the resource is not feasible, then the resource shall be removed from its location. Removal activities may consist of the relatively rapid removal of small isolated fossils from an active cut, to hand-quarrying of larger fossils over several hours, to excavations of large fossils or large numbers of smaller fossils from a bone bed over several days. These activities may include the assistance of the grading and excavation contractor’s equipment to facilitate removal. Any fossils encountered and recovered shall be prepared to the point of identification and catalogued before they are donated to their final repository. Any fossils collected shall be donated to a public, non-profit institution with a research interest in the materials, such as the Natural History Museum of Los Angeles County, San Bernardino County Museum, the John D. Cooper Archaeological and Paleontological Curation Center at the California State University, Fullerton, or Western Science Center in Hemet, California. Accompanying notes, maps, and photographs shall also be filed at the repository.

CR-8 Prior to the release of the grading bond, the paleontologist shall prepare a report summarizing the results of the monitoring and salvaging efforts, the methodology used in these efforts, as well as a description of the fossils collected and their significance. The report shall be submitted by the Applicant to the Community DevelopmentPlanning Director or his/her designee for approval. In addition, the report shall be submitted to at least one of the repositories mentioned in Mitigation

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Measure CR-7 and other appropriate or concerned agencies to signify the satisfactory completion of the project and required mitigation measures.

Geology and Soils
GEO-1 Site Preparation and Removals. All grading shall be accomplished under the observation and testing of the Project Geotechnical Engineer and Engineering Geologist in accordance with the recommendations contained in the Project Geotechnical Report, contained in Appendix F of this Draft EIR), the current codes practiced by the City of Corona and the Earthwork Specifications contained in Appendix IV of the Project Geotechnical Report.

Loose, compressible residual soil, non-engineered onsite fill, colluvium, alluvium, landslide debris, older alluvium and weathered bedrock shall be removed from fill areas prior to placement of fill and shall be removed from shallow cut areas, where exposed at finish grades. Guidelines to determine the depth of removals are presented below; however, the exact extent of the removals must be determined in the field during grading, when observation and evaluation of the greater detail afforded by those exposures can be performed by the Geotechnical engineer and/or Engineering Geologist.

The minimum backcut ratio shall be 1:1 (horizontal to vertical). The bottoms of all removal areas shall be observed, mapped and approved by the Engineering Geologist prior to fill placement. It is recommended that the bottoms of removals be surveyed and documented by the Project Civil Engineer.

Groundwater, if encountered during grading, shall be evaluated by the Geotechnical Engineer and/or Engineering Geologist. In general, groundwater is not anticipated to adversely affect grading although saturated soils and free water may be encountered along canyons and within alluvium removals. If groundwater is excessive, remedial measures such as horizontal drains or under drains may need to be installed. Further, settlement monuments and plates (see Plate VI of the Geotechnical Report) shall be installed during and after completion of grading to monitor settlement monuments and plates shall be used to determine when the majority of the primary settlement has been completed to allow for the release of affected lots for construction. • Stripping: Vegetation, debris and other deleterious materials are unsuitable as structural fill material and shall be disposed of offsite prior to commencing removals and placement of compacted fills. The thick, natural vegetative growth onsite is significant and will require consideration for removal. An onsite mulching operation may be considered. The mulched materials could then be used in future landscape areas. • Soil and Weathered Bedrock (unmapped): Loose, compressible onsite soils and underlying weathered bedrock shall be removed to expose the underlying competent bedrock materials prior to placement of compacted fill and when exposed in shallow cut area. An average removal depth of 5 feet is anticipated for removal of topsoil and weathered bedrock. In general, onsite soils and weathered bedrock are suitable to be re-used as structural fill when properly moisture-conditioned.
• Undocumented Artificial Fill (locally mapped as AFu): Fills associated with "recreational" grading, construction of unpaved access roads, mining operations and existing trench backfill shall be removed prior to fill placement. Generally, these artificial fills range from a depth of 3 to 20 feet. Local areas of undocumented fill associated with previous geotechnical investigations are not plotted on the map. Other fills, including roadway fills and trench backfill, are not mapped due to their localized extent and minor thickness.

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Removals shall extend below the undocumented fill until competent materials are encountered.
• Alluvium/Colluvium (map symbol Qal): All alluvium deposits exposed at existing or cut grades shall be entirely removed prior to fill placement. These deposits range in thickness from approximately 5 feet to 35 feet. Ginter and Associates recommends that all alluvial and colluvial soils below proposed fill areas and in cut areas be removed to expose competent bedrock or terrace deposits. Anticipated average removal depths for alluvium/colluvium areas are expected to vary to an estimated maximum thickness of 35 feet.
• Groundwater was not encountered during PSE's subsurface investigation within the alluvium onsite. However, access was limited and certain alluvial areas could not be investigated such as within Krooner Canyon. If "saturated" alluvium is encountered that possesses a degree of saturation of 85% of more and is consistent with depth to bedrock, consideration may be given to leaving the saturated alluvium in-place, provided that settlement time-delay consequences are acceptable to the owner. If saturated alluvium is encountered and is going to remain in-place, an additional liquefaction investigation may be required and dynamic settlement recommendations for those areas will likely change. • Older Alluvium (Qoa): All older alluvium shall be removed to expose the underlying competent bedrock. Generally, these deposits range in depth from 10 to about 20 feet. • Landslide Debris (Qls): All landslide debris that could adversely affect the proposed development shall be removed to expose the underlying competent bedrock. Generally, these deposits range in depth from 10 to about 29 feet, but may range up to around 35 feet in depth.
• Removals Along Grading Limits: Removals of unsuitable soils shall be required prior to fill placement along the grading limit. A 1:1 projection, from toe of slope or grading limit, outward to competent materials shall be established, when possible. Where removals are not possible due to grading limits, property line or easement restrictions, removals shall be initiated at the grading boundary (property line easement, grading limit or outside the improvement) at a 1:1 ratio inward to competent materials. Where this reduced removal criterion is implemented, special maintenance zones may be necessary. Affected areas shall be established, minimally, as a 1:1 projection from suitable removal bottom to finish ground surface. This condition is mainly expected in the slope areas. Where the projection intersects the face of the slope, the potential for distortion of the slope in response to postgrading settlements exists and provisions for future maintenance of such slopes shall be provided.

GEO-2 Slope Stability and Remediation
• Cut Slopes: The majority of cut slopes have been designed at a slope ratio of 2:1. The Engineering Geologist shall observe cut slopes and cut slope stabilization backcuts during grading. Modifications to the recommendations presented herein will likely be required based upon conditions exposed by grading.
• Williams Formation (KW): Cut slopes within the Williams Formation may expose adverse bedding that shall require remediation. The cut slope superjacent to Lots 278 and 279 is anticipated to require replacement with a buttress fill. Probable buttresses are anticipated

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for the cut slope above Lots 261 through 267 and the cut slope below the WQMP Basin and Lots 247 through 255, as depicted on Figure 1 and Figure 2 (pocket) of the Geotechnical Report.
• Ladd Formation: Cut slopes within the Ladd Formation may expose adverse bedding that shall require remediation. The majority of the cut slopes should expose bedding dipping into the slope or at an angle steeper than the proposed cut slopes (greater than 60 degrees).

Cut slopes within the Ladd Formation that expose bedding dipping into the slope or at an angle steeper than the proposed cut slopes are expected to be grossly stable; however, the final determination shall be made based on exposed conditions during grading. Cut slopes within the Ladd Formation may expose conglomerate resulting in poorly cemented sands, cobbles and boulders at finish grade, producing a rough uneven surface. These cut slopes shall be evaluated in the field by the Project Engineering Geologist or Geotechnical Engineer.

Replacement of those slopes with compacted stabilization fills may be required. Future exploration and in-grading observation could reveal more favorable geology in these specific areas.
• Alluvium/Colluvium: Cut slopes exposing alluvial/colluvial soils (Qal) shall require replacement with a drained stabilization fill. Typically, such corrective grading would be constructed with a minimum key width corresponding to one-half the full height of the superjacent slope, but not less than 15 feet. Minimum key depths at the toe shall be 2 feet.

All stabilization fills shall be provided with a backdrain and outlet system as detailed in Appendix IV of the Geotechnical Report.
• Silverado Formation: Cut slopes within the Silverado Formation are expected to be grossly stable; however the final determination shall be made based on exposed conditions during grading. Cut slopes within the Silverado Formation may expose poorly cemented sands, cobbles and boulders at finish grade, which would produce a rough uneven surface. These cut slopes shall be evaluated in the field by the Project Engineering Geologist or Geotechnical Engineer. Replacement of those slopes with compacted stabilization fills may be required.
• Fill Slopes: The majority of fill slopes on the project are designed at a maximum slope ratio of 2:1. The highest fill slope is approximately 160 feet in height and located subjacent to Lot

68. Based on the results of the calculations, the 2:1 fill slopes 160 feet and less in height, when properly constructed with onsite materials, are expected to be grossly stable, as designed. Keys shall be constructed at the toe of all fill slopes where unsuitable soil removals do not accomplish a minimum key width of one-half the slope height plus bench widths or twenty (20) feet, whichever is greater. Minimum key depths at the toe shall be 2 feet. Due to grading limit restrictions, removals of unsuitable soils beyond the proposed toe may be limited; therefore, additional slope maintenance shall be expected in the areas where a 1:1 projection into approved materials cannot be achieved.

GEO-3 Subsurface Drainage. Canyon subdrains are proposed as depicted on Figures 1 through 7 of the Geotechnical Report and shall consist of 6-inch and 8-inch diameter pipes and shall be constructed in accordance with the details shown in Appendix IV of the Geotechnical Report. Final determination of drain locations shall be made in the field. Outletting of subdrain systems shall require coordination with the Project Civil Engineer in determining suitable facilities to accept to drain water.

GEO-4 Overexcavation. Where a transition of cut and fill occurs across a finished lot, it shall be necessary to overexcavate the bedrock portions and replace it with compacted fill. The depth of bedrock

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overecavation shall be equal to 1/3 the maximum fill depth (after removals) on the fill side of the transition. Anticipated transition lots are shown on figures 1-7 of the geotechnical report. Cut pads shall be overexcavated a minimum of 5 feet to provide a uniform foundation material. Some highly expansive soils of the silverado formation may be encountered at grade in some areas. Consideration shall be given to increasing the overexcavation depth to mitigate for highly expansive soils, if warranted. Difficult excavation with a backhoe can be expected in some street areas. Ginter & associates recommends street overexcavation and replacement with compacted fill to facilitate utility emplacement in these street areas and driveways. Depths of overexcavation shall extend one (1) foot below the deepest utility line.

GEO-5 Fill Materials. Excavated on-site soils may be used as compacted fill. The fill materials to be used as compacted engineered fill shall be free of organics, debris, deleterious materials, and rocks over 6 inches maximum dimension, and must be approved by the project geotechnical engineer or project geologist prior to use. Import soils, if required, shall be evaluated by the project geotechnical engineer for suitability prior to delivery. Import soils shall be free of trash, debris or other objectionable materials. All import fill shall have engineering characteristics similar to the on-site soils.

GEO-6 Fill Placement, Moisture Conditioning, And Compaction. After approval of the over-excavation and prior to placement of any compacted engineered fill materials, the exposed removal bottoms shall be scarified to a minimum depth of six (6) inches. The area shall then be moisture conditioned approximately 1 to 2 percentage points above the optimum moisture content, and compacted to a minimum of 90 (or 93) percent of the applicable maximum density. The planned development will involve deep fills in the canyon areas and side-hill fill slopes. In order to reduce the amount of fill settlement, the fill shall be compacted to the minimum relative compaction shown below:

Fill Depth (Feet) Minimum Relative Compaction (ASTM: D1557) (%) 0 – 50 90
Below 50 93
Fill slopes shall also be constructed at the minimum relative compactions shown above, with the exception of the outer 3 feet of the slope face which can be placed at 90% relative compaction. Deep fill areas requiring 93% relative compaction are delineated in Plate VI of the Geotechnical Report.

Generation of oversized rock (over 8 inches in maximum dimension) from excavations in the bedrocks is anticipated. Oversize rock shall be placed in single file windrows not exceeding three feet in height and six (6) feet in width with a minimum equipment width (15 feet) separating each windrow or a rock blanket fill not exceeding two (2) to three (3) feet in height. Large erratic rocks shall be buried individually. Granular fill shall be thoroughly flooded in the rock voids and covered with a minimum two feet compacted fill blanket. Successive windrows shall be staggered and none shall be placed within 10 feet of finished grade or closer than 15 feet to compacted fill slope surfaces. Typical rock placement construction detail is provided in Appendix IV of the Geotechnical Report. Placement of rock windrows shall be performed under the observation and recommendations of the Project Geotechnical Engineer.

Fill materials shall be spread in thin lifts, moisture conditioned to about 1 to 2 percentage points over optimum moisture content and compacted to a minimum of 90 (or 93) percent of the laboratory maximum dry density as determined in accordance with ASTM Test Method D-1557. Each lift shall be treated in a like manner until the desired finished grades are achieved. The grading contractor shall have suitable and sufficient compaction equipment in operation to achieve the required

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compaction. When necessary, earthmoving equipment may be utilized for compaction or temporarily halted in order to permit adequate compaction of fills.

GEO-7 Slope Construction

1. Care shall be taken during grading to prevent spillage of loose materials over slopes to remain natural. Should loose soil be spilled onto natural slopes by the grading contractor, removal of the loose fill shall be required.

2. Fill shall be properly benched into firm bedrock or compacted fill as directed by the Project Engineering Geologist and/or Geotechnical Engineer during grading. Typical benching shall include 4-foot verticals exposing approved, competent material (see Appendix D – Typical Benching Detail of the Geotechnical Report).

3. In order to minimize surficial slumps on compacted fill slopes, the following grading procedures shall be used:
a) Where possible, fill slopes shall be constructed by overfilling a minimum of three (3) horizontal feet and then trimming back to expose the dense inner core of the slope surface. Compacted fill slopes shall be back-rolled during construction at intervals not exceeding four (4) vertical feet. Care shall be taken to construct the slope in a workmanlike manner so that it is positioned at its designed orientation and slope ratio. Achieving a uniform slope surface by subsequent thin wedge filling must be avoided. Any add-on correction to a fill slope shall be done by overfilling the affected area in horizontal, compacted lifts which must be benched into the existing fill prism. The overfilled slope may then be trimmed to the design gradient. b) Where fill slopes are planned above natural slopes and cannot be overfilled and trimmed back, the slopes shall be rolled for the entire height of the slope with a sheepsfoot roller and then finished with a grid roller. If the desired compaction is not obtained in this manner, a vibratory sheepsfoot roller may be required. To be most effective, this equipment shall be anchored and manipulated from a sideboom tractor. In lieu of a grid roller, the slope may be track rolled with a John Deere 450, Caterpillar D-8 dozer or equivalent. To obtain the required compaction and appearance of the slope face, the soil moisture shall be maintained at above optimum from the time of mass filling to the completion of grid rolling. c) The grading contractor shall take proper care to avoid spillage of loose material down the face of the slopes during grading and during drainage terrace and downdrain construction. Fine grading operations for benches and down-drains shall not deposit loose trimmed soils on the finished slope surfaces. Loose soil materials shall require removal.
d) Seeding and planting of slopes shall proceed as rapidly as possible to achieve a well-established and deep-rooted vegetal cover requiring minimal watering. The type of vegetation and watering schedule shall be established by a landscape architect familiar with hillside maintenance.

GEO-8 Earthwork Observations And Testing
a) The site preparation, over-excavation, and earthwork shall be performed under the observation and testing by a representative of the Project Geotechnical Engineer or Project Geologist.

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b) The fill shall be tested at the time of placement to verify that the required compaction is achieved.
c) The fill compaction shall be determined in the field by the Sand Cone Method (ASTM: D 1556) or Nuclear Gauge Method (ASTM: D 2216), or other test method approved by the Project Geotechnical Engineer.
d) During grading, an adequate number of field density tests shall be performed using approved test procedures in order to determine compliance of earthwork to the project requirements. The frequency of field density testing shall be in accordance with the recommendations of the Project Geotechnical Engineer.
e) Quality control testing performed to determine the acceptability of the fill compaction shall be based on the laboratory maximum dry density and optimum moisture content determined in accordance with ASTM: D 1557 test procedure. f) Any surface or subsurface obstructions, or questionable materials encountered during grading shall be brought immediately to the attention of the Project Geotechnical Engineer.

Deeper excavations may be required, should unsuitable soils be encountered locally, as determined by the Project Geotechnical Engineer and/or Project Geologist.

GEO-9 Deep Fill Settlement Monitoring. In deep fill areas, settlement monuments shall be installed and periodically surveyed by the project civil engineer to evaluate the magnitude and progress of settlements. Ginter & associates proposes positioning settlement monuments at strategic locations in the deeper fill areas as shown on figure vi of the geotechnical report. These shall be monitored on a regular basis until the primary settlement has stabilized before those areas released for construction.

GEO-10 Foundation Design. The compacted engineered fill at the project site is anticipated to be low to medium soil expansion potential. Presented below are preliminary geotechnical criteria for design of building foundations, based on medium soil expansion potential for the on-site soils:

Option 1 - Conventional Footing:

Allowable Bearing Pressure (1) = 1,500 pounds per square foot (psf) Minimum Footing Depth (2) = 24 inches
Minimum Footing Width = Continuous: 12 inches
Isolated: 24 inches
Passive Soil Pressure (3) = 250 psf/ft.

Friction Coefficient = 0.30 (ultimate)
Minimum Footing Reinforcement = Four No. 4 bars, 2 each at top and bottom Garage Door Grade Beam = 18 inches deep, Four No. 4 bars, Two each at top and bottom, tied into foundation elements

1. The above value may be increased 250 psf for each additional foot exceeding the minimum embedment depth and/or width, subject to a maximum of 2,500 psf. Allowable bearing pressures may be increased by one-third for short term loading due to wind or seismic forces.

2. Footing depth is from lowest adjacent finished soil grade. Footings shall be deepened, as necessary, to provide setback distance from adjacent slope in conformance with CBC criteria.

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3. Value applies to level soil condition, and is subject to a maximum of 2000 psf.

Option 2 – Post-Tensioned Foundation:

If post-tensioned slab/footing system is selected for the subject project, the design may be based on the geotechnical criteria shown below for medium soil expansion potential. These are based on the guidelines presented in the PTI, Third Edition design manual.

Thornthwaite Moisture Index = -20
Equilibrium Suction = 3.6
Edge Lift Moisture Variation Distance, em = 5.1 feet
Edge Lift, ym = 1.1 inches
Center Lift Moisture Variation Distance, em = 9.0 feet
Center Lift, ym = 0.47 inches
Minimum Footing Depth (Exterior) = 18 inches below adjacent grade The above foundation criteria are based on medium soil expansion consideration only. Foundation design shall consider anticipated post-construction settlements, as appropriate. Foundation design details such as slab thickness, concrete strength, reinforcements, etc. shall be established by the Project Structural Engineer considering medium soil expansion and settlement potential provided below.

GEO-11 Foundation Settlement. Total static and differential post-construction settlements for footings designed and constructed in accordance with the criteria given below and supporting loads not exceeding the typical loadings for residential construction (column and wall loads on the order of 30 kips and 3 kips/lineal foot, respectively) are not anticipated to exceed the values shown below. The settlement estimates shall be confirmed based on review of the foundation plans. Structures shall be designed for the following post-construction settlements:
- Total settlement = 1 inch
- Differential settlement = ¾-inch (*)
(*) Between similarly loaded column footings and for continuous footings and slabs over a distance of approximately 30 feet.

General Remarks:
i. Footing depths shall not be allowed to be affected adversely, such as through erosion softening, digging, landscaping, etc.
ii. Where foundations encroach closer than five (5) feet horizontally from the flow line of drainage swales, the footing shall be deepened sufficiently to maintain the required embedment depth below the adjacent flow line.
iii. Foundation details such as concrete strength, reinforcements, etc. shall be established by the Project Structural Engineer, considering the loading and medium soil expansion potential. The footing and slab reinforcements recommended in the Geotechnical Report are minimum requirements. More restrictive criteria based on structural design considerations or Code requirements shall govern.

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iv. Foundation excavations shall be observed and approved by the Project Geotechnical Engineer prior to the placement of reinforcement or concrete. Forming of footing excavations may be required. Excavations shall be free of slough and debris and thoroughly moisture conditioned prior to placing concrete.
v. Excavated material from footing and utility trenches shall not be placed in slab-on-grade areas unless properly compacted and tested.

GEO-12 Slab-On-Grade.

Recommended Minimum Criteria For Slab-On-Grade Are Shown Below:

Concrete Floor Slabs: Concrete floor slabs shall be 5 inches thick (minimum) and shall be reinforced with No. 3 bars at 18 inches on center, each way at mid height. No. 3 bars at 18 inches on center shall be provided connecting floor slabs to footings. In order to minimize migration of moisture up the concrete slab from soil subgrade and damage to floor coverings, a moisture barrier/water vapor retarder is recommended beneath floor slabs as discussed hereinafter.

Moisture/Water Vapor Retarder for Concrete Slab-on-Grade: In order to reduce the potential for moisture/water vapor migration up through the slab and possibly affecting floor covering, a moisture/vapor retarder is recommended under concrete floor slab-on-grade. The moisture barrier shall be properly installed, lapped and sealed in accordance with the manufacturer’s specifications.

Punctures and rips shall be repaired prior to placement of sand. At a minimum, this moisture/water vapor retarder shall consist of 10- millimeter thick polyethylene (“Visqueen”), lapped and sealed, and placed mid-height within a 4-inch coarse sand layer. This moisture/water vapor retarder shall be installed in accordance with manufacturer’s specifications. The following recommendations are based on the tentative guidelines by the American Concrete Institute (ACI, April 2001) to reduce the potential moisture/water vapor intrusion in concrete slab-on-grade. Based on Ginter & Associates’ review of available literature, it appears that the ACI procedure would be more effective to help reduce potential moisture/water vapor migration up through concrete slab-on-grade.

Recommendations based on the ACI guidelines are presented below:
• The moisture/water vapor retarder shall consist of high strength polyethylene membrane and shall meet or exceed the ASTM: E-1745-97 Class C material requirements for water vapor permeance, tensile strength and puncture resistance. The vapor retarder shall consist of “Moistop Plus” (Fortifiber Building Products Systems) or “Vapor Block” VB 15 (Americover, Inc.), or approved equal. The vapor retarder shall be underlain by a capillary break comprised of minimum 4 inches thick pea gravel layer. The gravel layershall be placed and compacted on approved soil sub-grade.
• The membrane shall be placed on approved gravel layer and properly lapped and sealed.

Membranes intersecting utility pipes, sewer lines, ducts or drains shall be properly wrapped around the penetrations and sealed. All punctures and rips in the membrane shall be repaired prior to placement of concrete, following manufacturer’s recommendations. The vapor retarder shall be installed in general accordance with the procedures outlined in ASTM: E-1643, and in conformance with the installation procedures recommended by the manufacturer.
• To minimize slab curling, a low slump concrete (low shrinkage mix design) shall be used for the slab construction, as determined by the Project Structural Engineer.

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The moisture/water vapor protection for concrete slab-on-grade shall be selected based on cost and construction considerations, and considering potential future problems resulting from improper and uncontrolled landscape irrigation practices. Regardless of the moisture/water vapor retarder option selected, it should be emphasized that proper control of irrigation and landscape water adjacent to the structure is of paramount importance.

GEO-13 Driveways. Driveway concrete slabs shall be 5 inches thick (minimum) with no. 3 bars at 18 inches on center, each way at mid-height. The slab may be placed directly on properly prepared sub-grade.

No moisture barrier is required under driveway slabs.

GEO-14 Exterior Flatwork. Exterior concrete flatwork (e.g. Sidewalks, walkways) shall be 4 inches thick (minimum), with no. 3 bars at 24 inches on center, each way at mid-height and placed on properly prepared sub-grade. Hardscape areas within two feet of the descending slopes shall include a thickened edge deepened to provide a minimum five (5) feet horizontal setback between the bottom outside face of the thickened edge and slope face.

GEO-15 Sub-Grade Pre-Saturation. Prior to concrete placement, the soil sub-grade shall be thoroughly wetted to about 12 inches in depth at a moisture condition of about 2 to 3 percentage points above the optimum moisture content.

GEO-16 General. Interior floor slabs and exterior concrete flatwork, including driveway, shall be properly designed for the construction and service loading conditions, potential settlements and soil expansion. The structural details, such as slab thickness, concrete strength, reinforcing criteria, joint spacing, etc. Shall be established by the project structural engineer. The recommended minimum reinforcements for concrete slabs provided above are intended for preliminary design only. More restrictive criteria as dictated by structural design or regulatory requirements shall govern.

GEO-17 Retaining Walls
• Foundations: Retaining wall foundations may be supported on either compacted engineered fill or competent bedrock. If a bedrock/fill transition is encountered, the bedrock portion shall be overexcavated minimum 2 feet and replaced with approved compacted fill. Alternatively, a cold joint shall be constructed in both the footing and the wall. Footings may be designed in accordance with the foundation design criteria presented in the Geotechnical Report when embedded at least two feet below lowest adjacent grade.

Footings located on or at top of slopes shall be deepened, as necessary, to provide minimum lateral setback between footing and slope faces in accordance with CBC requirements. • Lateral Earth Pressures: The earth pressures acting on retaining walls depend primarily on allowable wall movement, type of backfill materials, backfill slopes, wall inclination, surcharges, and any hydrostatic pressure. The following lateral earth pressures are recommended for vertical walls with no hydrostatic pressure and no surcharge loading:

Wall Condition Backfill Type Lateral Earth Pressure (Equivalent Fluid Pressure) (pcf)
Level 2:1 (H:V)
Active (Cantilever) Sandy Soils 40 65
The surcharge effect of anticipated loads on the wall backfill (i.e. traffic, construction equipment, footings, etc.) shall be included in the wall design. If the wall is free to deflect, 33 percent of the maximum surcharge load located within a distance equal to the height of wall shall be used in the design.

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• Backfill: Retaining wall backfill shall consist of predominantly granular non-expansive soils.

The backfill shall extend within a 45-degree plane from the wall footing. Retaining wall backfill shall be mechanically compacted to minimum 90 percent of the applicable laboratory maximum density and performed under the observation and testing of the Project Geotechnical Engineer. No jetting, ponding, or flooding shall be permitted. No backfill shall be placed against concrete until minimum design strengths are attained. • Backfill Drainage: The wall design shall include waterproofing and weep holes or sub-drains or backdrains, as appropriate, for relieving possible hydrostatic pressures. If on-site soils are utilized for wall backfill, the design shall include a prefabricated drainage blanket (such as Miradrain 2000, or equivalent). At a minimum, sub-drains shall consist of 4-inch diameter, perforated Schedule 40, PVC pipe or equivalent, embedded in approximately 3 cubic feet per lineal foot of ¾-inch (maximum) rock, or approved alternate. This permeable material shall be enveloped in Geofabric consisting of Mirafi 140 or equivalent. The pipe and trench bottom shall be sloped at a gradient of 2+ percent to a suitable discharge outlet. Sub-drains placed behind retaining walls shall be approved by the Project Geotechnical Engineer prior to backfill placement.

GEO-18 Soil Corrosion. The previous geotechnical consultants, Pacific Soils Engineering, Inc., performed preliminary testing and indicated that the site soils are corrosive to metals. Therefore, representative finished grade samples shall be tested for corrosion suites (sulfate, chloride, ph and resistivity) upon completion of grading. It may be necessary to retain a corrosion engineer for consultation.

GEO-19 Utility Trench Backfill
• Bedding material shall consist of on-site sandy or imported materials exhibiting a San Equivalent (S.E.) value of 30 or greater.
• The on-site soils are considered suitable for trench backfill, provided they are free of organic materials and oversize rocks.
• Backfill of all exterior and interior trenches shall be placed in thin lifts not exceeding 4 inches and mechanically compacted to achieve a relative compaction of not less than 90% based on ASTM: D1157. Care shall be taken not to damage utility lines. • Utility trenches shall not be located within the influence of footings. This is defined as a zone located below the footing and a line sloping at an inclination of 1:1 (horizontal to vertical) outward from the outside edge of footings. If utility lines are located within the zone of footings, the backfill shall be compacted to a minimum 95 percent relative compaction or slurry backfilled (minimum 1-1/2 sack cemented sand mix. • To reduce potential water migration into building subgrade through the granular bedding/shading layer and/trench backfill, utility trenches shall be backfilled with the onsite finer grained materials or sand-cement slurry for minimum 3 feet length at their entry points.
• Trenches in fill soils and alluvial deposits greater than 4 feet in depth shall be shored or sloped back as required by the local regulatory agency, the state of California Division of Industrial Safety Construction Safety Orders, and Federal OSHA requirements.

GEO-20 Asphalt Concrete Pavement. Preliminary asphalt concrete pavement sections for the planned streets in the development were developed utilizing the Caltrans method of design and the structural section design guide for California cities and counties. The following recommended pavement

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sections were computed assuming an “r” value of 30 for site soils compacted as sub-grade material, and assumed traffic indices. The actual “r” value will depend on the soil conditions exposed at the planned street sub-grade elevations. During rough grading, “r” value testing shall be performed on the pavement sub-grade soils to confirm the pavement design basis. Further analysis and evaluation are necessary if the design traffic index and the sub-grade “r” value are different from those used in Ginter & Associates’ analyses.

Traffic Index Recommended Minimum Pavement Section
Asphalt Concrete
(inches)
Aggregate Base
(inches)
Total (inches)

5.0 6.0

7.0 8.0

3.0 4.0

4.0 5.0

6.0 8.0

10.0 12.0

9.0 12.0

14.0 16.0
Aggregate base shall consist of crushed aggregate base (CAB) or crushed miscellaneous base (CMB) and shall comply with the specifications outlined in the “Standard Specifications for Public Works Construction”, (“Green Book”). The base material shall be compacted to minimum 95 percent of the maximum laboratory density, determined in accordance with ASTM: D-1557. The soil sub-grade shall be compacted to minimum 90 percent relative compaction. The subgrade soils shall exhibit a firm and unyielding surface, in addition to the recommended minimum compaction. Final compaction and testing of pavement sub-grade shall be performed just prior to placement of aggregate base.

GEO-21 Site Drainage. All roof and surface drainage shall be directed away from structures and their appurtenances and slopes to approved drainage facilities. Ponding of water shall be avoided. For graded soil areas, a minimum gradient of 2 percent away from structures shall be maintained. The drainage patterns designed by the project civil engineer shall be established at the time of fine grading and maintained throughout the life of the structure or, if altered, shall be replaced with a properly designed area drain system. Irrigation activities at the site shall be monitored and controlled to prevent overwatering. Planter areas adjacent to structures shall be avoided. If utilized, such planters shall include measures to contain irrigation water and prevent moisture migration into walls and under foundations and slabs-on-grade.

GEO-22 Slope Planting, Irrigation And Maintenance. General guidelines for slope planting, irrigation and maintenance are shown below:
a) Slope planting shall consist of appropriate drought resistant vegetation as recommended by the Landscape Architect. Landscaping of slopes shall be completed as soon as possible and properly maintained.
b) The property owner is responsible for proper irrigation and for maintenance and repair of installed irrigation systems. Leaks shall be repaired immediately. Sprinklers shall be adjusted to provide maximum coverage with a minimum of water usage and overlap. Over-watering with consequent excessive runoff and ground saturation shall be avoided. c) If automatic sprinkler systems are installed, their use shall be adjusted to account for natural rainfall conditions.
d) All interceptor ditches, drainage terraces, down-drains, and any other drainage devices that have been installed shall be maintained and cleaned.

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e) If rodent activity is present, the property owner shall undertake a program for the elimination of burrowing animals. This shall be an ongoing program in order to promote slope stability.
f) Water shall not be allowed to flow over the constructed or natural slopes. This may require the construction of berms or ditches along the top of slopes, if such devices are not in place.

GEO-23 Additional Investigation. Additional geologic and geotechnical investigation may be necessary during the 40-scale grading plan review phase to obtain supplemental information relative to the site geologic conditions and engineering properties of onsite materials and to confirm the preliminary recommendations provided herein.

Greenhouse Gas Emissions
GHG-1 Climate Action Plan Compliance. Prior to issuance of building permits, the Project Applicant shall demonstrate that appropriate building construction measures shall apply to achieve a minimum of 100 points per Appendix C to the City of Corona 2019 Climate Action Plan (CAP) Update. The conceptual measures anticipated for the Project are listed in Attachment C of the Project’s Air Quality and Greenhouse Gas Assessment (AQ/GHG Assessment), which is appended to this EIR Addendum as Technical Appendix C. The conceptual measures may be replaced with other measures as listed in the CAP Screening Tables (Appendix C to the CAP Update), as long as they are replaced at the same time with other measures that in total achieve a minimum of 100 points per Appendix C to the City of Corona CAP Update.

Hazards and Hazardous Materials
PS-1 Prior to issuance of building permits, the project Applicant shall obtain CFD review and approval of the site plan, fuel modification plan, and project design features including, but not limited to roadway design to meet or exceed minimum fire and emergency access requirements including ingress/egress; driveway and fire lane width; turning radii inside and outside; grades/elevations; adequate on-site space to park CFD apparatus; fire hydrant sizing, spacing and locations; fire protection systems including automatic fire sprinkler systems and fire alarms installed in each residence; availability of adequate firefighting water flow; and approved building materials. The project Applicant shall implement the fuel modification plan and other CFD-required fire life safety features prior to issuance of a certificate of occupancy.

PS-2 Prior to the issuance of building permits, the project Applicant shall pay the required service and development fees pursuant to the “Fire Facilities Fund” as amended in Chapter 3.36 of the CMC to the City of Corona for the public improvements and facilities associated with the CFD.

Hydrology and Water Quality
HYD-1 For Drainage Management Area C, the final engineering for the drainage of Area C shall include a concrete impact basin energy dissipater and rip-rap pad and shall be designed in accordance with City standards. The outlet velocity shall be at or below the existing condition .. The plans shall be submitted to the City for review and approval.

Land Use and Planning
PDF LU-1 The project applicant will survey and post the location of the private property boundary line where it abuts NFS lands within the project area.

Noise
NS-1 Construction and demolition shall be restricted to the hours of 7:00 A.M. to 8:00 P.M. Monday through Saturday, and 10:00 A.M. to 6:00 P.M. on Sundays and Federal holidays.

NS-2 Noise and groundborne vibration construction activities whose specific location on the project site may be flexible (e.g., operation of compressors and generators, cement mixing, general truck idling) shall be conducted as far as possible from the nearest noise-and vibration-sensitive land uses.

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NS-3 Construction and demolition activities shall be scheduled so as to avoid operating several pieces of equipment simultaneously, which causes high noise levels.

NS-4 The use of construction equipment or construction methods with the greatest peak noise generation potential shall be minimized (i.e., use of drills, jackhammers).

NS-5 The project contractor shall use power construction equipment with state-of-the-art noise shielding and muffling devices.

NS-6 Barriers such as, but not limited to, plywood structures of flexible sound control curtains shall be erected between the proposed project and the adjacent existing residences to the northeast and west, to minimize the amount of noise to the maximum extent feasible during construction.

NS-7 All construction truck traffic shall be restricted to truck routes approved by the City of Corona Public Works Department, which shall avoid residential areas and other sensitive receptors to the extent feasible.

NS-8 Adjacent land uses within 300 feet of the construction site shall be notified about the estimated duration and hours of construction activities at least 30 days before the start of construction.

NS-9 Prior to approval of any grading permits that require blasting activities and a blasting permit, the Project Applicant shall prepare and submit for City review and approval of a Blasting Noise and Vibration Monitoring and Abatement Plan (“Noise and Vibration Abatement Plan”). At a minimum, the required Noise and Vibration Abatement Plan shall include the following:
 Specified blasting hours, restricting blasting only to Monday through Friday and only between the hours of 8:00 a.m. and 3:00 p.m.
 Conceptual blast designs. Conceptual blast designs shall be based on “scaled distance” criteria (i.e., defined as the distance in feet between a blast drill hole and the structure of concern, divided by the square root of the explosives loading per delay period in poundsunits in feet per pound1/2). The scaled distance chosen for the initial design should be supported by statistical analysis indicating the resulting ground vibration will be less than the criteria set for the Project. The scaled distance used for production blasts may be modified based on the results of the test blast(s) but should be conservative enough to produce vibration and airblast levels within the project specifications. It should be noted that the conceptual blast designs are general and will need to be modified during the project based on actual conditions encountered in the field and the results of site-specific blasting.  Test Blasts. One or more test blasts shall be performed in an area outside of critical distance of residential structures or other improvements of concern; the critical distance shall based on the scaled distance calculations with a 10 percent distance increase.  Controlled Blasting Techniques. Include techniques and procedures to control and monitor flyrock, airblast, and ground vibration:
o Flyrock mitigation measures may include: soil cover, leaving alluvial materials in place over materials to be blasted, and/or blast mats.
o Crushed rock (i.e., 3/8”) should be used for stemming materials o Drill cuttings are not acceptable.
o All stemming materials should be tamped in-place.
 The Blasting Noise and Vibration Abatement Plan shall include procedures for the submittal of blast reports and record keeping.

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 The Blasting Noise and Vibration Abatement Plan shall outline safety measures and procedures to notify property owners that blasting will occur.  If specified vibration limits are exceeded, the Noise and Vibration Abatement Plan shall require blasting operations to cease immediately, and a revised blasting plan shall be submitted to the City of Corona. Blasting shall not resume until a revised blasting plan has been reviewed and the Contractor has expressed in writing the conditions that will be applied to further blasting work.
 Pre-Blast Survey Requirements. The following measures shall be specified in the Noise and Vibration Abatement Plan:
o Prior to the commencement of any blasting, a pre-blast survey of the conditions of all existing property and aboveground utilities located within 1500 feet of any potential blasting areas shall be conducted or as specified by the City of Corona, whichever is a lesser distance.
o Prior to the commencement of any blasting, notification of neighbors withing 1,500 feet of the blasting area shall be made via first class mail or hand delivery of written notice. o The pre-blast survey shall be conducted by a third-party company with a minimum of five years of experience performing pre-blast and similar type surveys. o The pre-blast survey shall include a photographic record of all visible and accessible structures, facilities, utilities, or other improvements. If property owners refuse surveys, provide copies of certified mail letters documenting attempts to provide the survey. o The required surveys shall include a description of the interior and exterior condition of the various structures examined. Descriptions shall include the locations of any cracks, damage, or other existing defects and shall include information needed to identify and describe the defect, if any, and to evaluate the construction operations on the defect.

Survey records shall include photos of all cracks and other damaged, weathered, or otherwise deteriorated structural conditions. If necessary, macro lenses and flash illumination shall be used to ensure defects are shown clearly in the photographs. Photos shall contain an accurate date stamp. No blasting shall occur prior to the completion of surveys of surrounding residential properties.
o Surveys shall be repeated at facilities or properties where damage concerns have been expressed by individual residents, property owners, or other concerned parties. Details of any observed changes to surveyed structures and documenting photos shall be reported and submitted.

Project grading and blasting contractors shall be required to ensure compliance with the Blasting Noise and Vibration Abatement Plan requirements and shall permit periodic inspection of the construction site by City of Corona staff or its designee to confirm compliance. The requirements of the Blasting Noise and Vibration Abatement Plan shall also be specified in bid documents issued to prospective construction contractors. The City of Corona shall review all monitoring reports to ensure compliance with the Blasting Noise and Vibration Abatement Plan and shall have the authority to stop all blasting activities on site if it is determined that blasting activities are not being conducted in conformance with the Blasting Noise and Vibration Abatement Plan. Additionally, project grading and blasting contractors shall be required to ensure compliance with the Corona Fire Department publication, “Explosives, Blasting and Pyrotechnics Permit Guidelines per 2022 CFC,” dated

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Mitigation No. Mitigation Measure/Implementing Action
December 5, 2023, and included as Technical Appendix L of Addendum No. 1 to the Skyline Heights Project Environmental Impact Report.

Public Services
PS-1 Prior to issuance of building permits, the project Applicant shall obtain CFD review and approval of the site plan, fuel modification plan, and project design features, all of which shall implement the recommendations of the Project’s Fire Protection Plan (“FPP”; Technical Appendix K to Addendum No. 1 to the Skyline Heights Project (SHP) Environmental Impact Report [“EIR”; State Clearinghouse No. 2014021003]). CFD shall review the site plan, fuel modification plan, and project design features to ensure that they incorporate all applicable recommendations of the FPP including, but not limited to roadway design to meet or exceed minimum fire and emergency access requirements including ingress/egress; driveway and fire lane width; turning radii inside and outside; grades/elevations; adequate onsite space to park CFD apparatus; fire hydrant sizing, spacing and locations; fire protection systems including automatic fire sprinkler systems and fire alarms installed in each residence; availability of adequate firefighting water flow; and approved building materials.

PS-2 Prior to the issuance of building permits, the project Applicant shall pay the required service and development fees pursuant to the “Fire Facilities Fund” as amended in Chapter 3.36 of the CMC to the City of Corona for the public improvements and facilities associated with the CFD.

PS-3 Prior to the issuance of building permits, the project Applicant shall reserve a portion of the project site for a future radio facility site, the specific size and location of which is subject to review and approval of CPD.

PS-4 Prior to the issuance of building permits, the project Applicant shall pay the required service and development fees to the City of Corona for the public improvements and facilities associated with the CPD.

PS-5 Prior to the issuance of building permits, the project Applicant shall comply with the City of Corona Municipal Code (Chapter 16.35, Park Dedication and In Lieu Fees). The City’s subdivision map review authority shall determine whether land dedication, an in lieu fee, or a combination of the two shall be required in conjunction with its approval of a subdivision map.

PS-6 Pursuant to Section 65995 of the California Government Code, the project Applicant shall pay the required SB 50 mitigation fees to the CNUSD.

PS-7 Prior to the issuance of a building permit for the construction of the proposed project, the project Applicant shall pay the required service and development fees pursuant to the Section 16.23.080 of the CMC and in the City’s Library Facility and Collection section of the Master Facility Plan to the City of Corona for the public improvements and facilities associated with the CPL.

Transportation
TR-1 Intersection 3 – Paseo Grande at Ontario Avenue: If the project is developed prior to the construction of the Foothill Parkway Extension then prior to issuance of any building permit for the project, the Applicant shall install a traffic signal and design for two-phase operation.

TR-2 Intersection 4 - Border Avenue at Ontario Avenue: Prior to issuance of any building permit for the project, a traffic signal designed for two-phase operation shall be installed. Intersection improvements shall include: 1) restriping of the eastbound shared left-through lane and the exclusive right-turn lane on Ontario Avenue to an exclusive left-turn lane and a shared through-right turn lane and 2) restriping of the westbound shared left-through lane and the exclusive right-turn lane on Ontario Avenue to an exclusive left-turn lane and a shared through-right turn lane.

TR-3 Intersection 10 - Elysia Street at Foothill Parkway: Prior to issuance of any building permit for the project, the Applicant shall install a traffic signal and design for five-phase operation to the satisfaction of the City.

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TR-4 Intersection 11 - Trudy Way at Foothill Parkway: Prior to issuance of any building permit for the project, the Applicant shall install a traffic signal and design for three-phase operation to the satisfaction of the City.

TR-5 Roadway Segment 2 – Paseo Grande between Ontario Avenue and Green River Road: If the project is developed prior to the construction of the Foothill Parkway Extension then the Applicant shall improve this roadway segment to a 4-Lane Secondary Roadway to the satisfaction of the City prior to issuance of any building permit for the project.

Utilities and Service Systems
UTIL-1 Prior to issuance of the first certificate of occupancy, the project Applicant shall pay the required Corona Utilities Department water connection fees as set forth in Section 13.04.040 and Section

13.14.050 of the CMC.

UTIL-2 Prior to the issuance of the first certificate of occupancy, the project Applicant shall pay the required Corona Utilities Department sewer connection fees as set forth in Section 13.08.600 of the CMC.

UTIL-3 Prior to the issuance of any demolition or construction permit, the project Applicant shall provide a copy of the receipt or contract indicating that the construction contractor shall only contract for waste disposal services with the City’s exclusive franchise contract hauler, Waste Management of the Inland Empire. The contract specifying recycled waste service shall be presented to the Municipal OperationsUtilities Department prior to approval of the first certificate of occupancy for the project.

UTIL-4 In order to facilitate onsite separation and recycling of construction related wastes, the construction contractor shall provide temporary waste separation bins on-site during demolition and construction activities.

UTIL-5 Waste Diversion. The project Applicant shall demonstrate a plan to ensure adherence to the City of Corona Waste Diversion Program, which diverts 75 percent of all waste away from landfills. The City shall ensure that the project proponent implements the waste diversion plan objectives. These requirements shall be specified in the final architectural plans to be approved by the City of Corona Planning and Building AgencyDivisions prior to issuance of building permits.

1.7 Summary of Findings
The EIR Addendum evaluates the potential environmental impacts of the revised Skyline Heights Project (SHP) in the City of Corona. The proposed development includes residential structures, associated infrastructure (such as roads, utilities, and fire protection measures), parks, and open space. The revised Project involves some modifications to the Approved Skyline Heights Project, but the general scope of the development remain consistent with the Approved Project.

Based on the analysis presented in this EIR Addendum, the revised Skyline Heights Project would not result in any new significant environmental impacts compared to those identified in the original SHP EIR. All impacts, with the exception of those related to aesthetics, would be reduced to less-than-significant levels through the implementation of mitigation measures. Impacts to aesthetics, however, would remain significant and unavoidable, consistent with the findings of the original EIR. The Project incorporates additional biological mitigation measures to further reduce potential impacts to biological resources, ensuring that all environmental impacts are effectively addressed.

In accordance with the analysis presented in Section 2.0, and pursuant to Sections 15162, 15164, and 15183 of the State CEQA Guidelines, the City of Corona has determined that:

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Environmental Impact Report Addendum

• The Proposed Project Modifications do not result in substantial changes that would require major revisions to the previously prepared EIR due to new or substantially more severe significant environmental effects than previously analyzed; and
• No substantial changes in circumstances have occurred that would result in new or more severe significant environmental impacts than previously analyzed; and
• No new information of substantial importance as described in Section 15162 (a)(3) has been identified that would require major revisions to the analysis or conclusions presented in the previously-prepared EIR.

1.8 Cumulatively-Considerable Impacts
Cumulative effects that would result from implementation of the Project have been evaluated throughout this EIR Addendum, which concludes that, with exception of significant and unavoidable impacts to aesthetics as disclosed by the SHP EIR, such impacts would not occur, would be less than significant, or would be reduced to a level below significant with implementation of the mitigation measures specified by the SHP EIR (as modified/ supplemented herein), standard County COAs, and/or regulatory requirements. Additionally, this EIR Addendum concludes that the Project as proposed would not result in any new or more severe cumulative effects beyond what was already evaluated and disclosed by the SHP EIR. All applicable mitigation measures identified as part of the SHP EIR and that were imposed to address cumulatively-considerable effects would continue to apply to the Project as revised, except as modified or supplemented by this Addendum to the SHP EIR. The analysis throughout this EIR Addendum demonstrates that all Project impacts would be less than significant, or would be reduced in comparison to the analysis and conclusions of SHP EIR. Additionally, the analysis herein demonstrates that physical impacts associated with the Project (e.g., biological resources, cultural resources, geology/soils, etc.) would not substantially change or increase compared to the analysis presented in SHP EIR. Therefore, because the Project would have similar or reduced cumulative impacts to the environment as compared to what was evaluated and disclosed in SHP EIR, the Project would not result in any new or increased impacts to the environment beyond what was evaluated, disclosed, and mitigated for by the SHP EIR. Therefore, implementation of the Project would not result in any new impacts not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.

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2.0 ENVIRONMENTAL CHECKLIST
State CEQA Guidelines Section 15164(a) requires that a lead agency or responsible agency shall prepare an addendum to a previously-certified Environmental Impact Report (EIR) if some changes or additions are necessary but none of the conditions described in Section 15162 of the State CEQA Guidelines calling for preparation of a subsequent EIR have occurred. State CEQA Guidelines 15168(c)(4) clarifies that where later activities involve sitespecific operations, the agency should use a written checklist or similar device to document the evaluation of the site and the activity to determine whether the environmental effects of the operation are within the scope of the prior EIR. The focus of this analysis is on the identified changes associated with the proposed Skyline Heights Specific Plan (SHSP) and Revision No. 1 to Tentative Tract Map No. 36544 (TTM 36544R1) (referred to herein as the “Project” or “proposed Project”) and whether the changes proposed as part of the Project would result in any new or more severe impacts to the environment beyond what was evaluated and disclosed in the prior EIR and whether changes or additions to the mitigation measures presented in the Skyline Heights Project EIR (herein, “SHP EIR”) are necessary to address the current Project’s environmental effects.

The following analysis is used to: (1) compare the environmental impacts of the currently-proposed Project with the impacts identified and disclosed in the previously-certified Skyline Heights Project EIR (herein, “SHP EIR”); (2) to identify whether the proposed Project would result in new or more severe significant environmental impacts beyond what was evaluated and disclosed by the SHP EIR; and (3) to identify if there have been substantial changes with respect to the circumstances under which the currently-proposed Project would be undertaken since certification of the SHP EIR that would result in new or more severe significant environmental effects. This analysis confirms that the currently-proposed Project’s impacts are within the scope of the previously-certified Skyline Heights Project EIR, and that the proposed Project would cause no new or more severe significant effects and no new or revised mitigation measures are required.

The following discussion has been undertaken pursuant to the provisions of CEQA Guidelines Section 15164 to provide the City of Corona with the factual basis for determining whether any of the conditions listed in State CEQA Guidelines Section 15162 calling for the preparation of a Subsequent EIR have occurred with respect to the currently-proposed Project. Pursuant to State CEQA Guidelines Section 15164(a), if none of the conditions listed in State CEQA Guidelines Section 15162 are met, then the City of Corona, as Lead Agency for the proposed Project, is required to prepare an EIR Addendum for the currently-proposed Project.

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Environmental Impact Report Addendum

2.1 Aesthetics
New
Significant
Impact
More
Severe
Impacts
New Ability to
Substantially
Reduce
Significant
Impact
No Substantial
Change from
Previous
Analysis
Except as provided in Public Resources Code Section 21099, would the Project:
a. Have a substantial adverse effect on a scenic vista? ☐ ☐ ☐ ☒ b. Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic
buildings within a state scenic highway?
☐ ☐ ☐ ☒
c. In non-urbanized areas, substantially degrade the
existing visual character or quality of public views of the site and its surroundings? (Public views are those
that are experienced from publicly accessible vantage
point). If the project is in an urbanized area, would
the project conflict with applicable zoning and other
regulations governing scenic quality?
☐ ☐ ☐ ☒
d. Create a new source of substantial light or glare,
which would adversely affect day or nighttime views
in the area?
☐ ☐ ☐ ☒

ENVIRONMENTAL ANALYSIS
a) Would the Project have a substantial adverse effect on a scenic vista? Skyline Heights Project EIR Findings: Significant and Unavoidable Impact. The SHP EIR found that construction and operation of the SHP would permanently alter the viewshed at the site and views of scenic resources in the local area. Therefore, the SHP EIR identified significant and unavoidable impacts relative to views and scenic vistas. (Corona, 2015, pp. 4.A-14 to 4.A-15)
EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. The currently-proposed Project would result in reduced impacts to scenic vistas in comparison to the project evaluated in the SHP EIR. Specifically, the proposed Project would decrease the number of dwelling units by 16 (from 292 to 276 units). It also would reduce the area of physical disturbance, with the Approved Project affecting approximately 170.70 acres of the property, while the proposed Project would disturb only 151.8 acres on site and approximately 7.0 acres off site, with the off-site impact areas mostly comprising developed/disturbed/ornamental vegetation types. In general, the proposed Project's areas of disturbance would remain within the limits identified in the Approved Project.

Furthermore, the proposed Project would increase open space (i.e., natural open space, manufactured slopes, drainage basins, and public/private parks) from 149.55 acres under the Approved Project to 182.48 acres under the proposed Project, which represents an increase of 22.0% compared to the Approved Project. Areas of additional open space include the southern portion of the property that is located at higher elevations. Moreover, the land uses proposed as part of the Project, including proposed residential and park uses, would be substantially

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Environmental Impact Report Addendum

consistent with the project evaluated in the SHP EIR. Furthermore, future development on site would be subject to compliance with the development standards and design guidelines contained in the proposed Skyline Heights Specific Plan, whereas the Approved Project was not subject to any approved specific plans. Based on these considerations, it can be concluded that the currently-proposed Project would result in an overall reduction in impacts to scenic vistas as compared to the project evaluated in the SHP EIR.

Although the Project would result in reduced impacts to scenic vistas, consistent with the findings of the SHP EIR the currently-proposed Project still would result in a significant and unavoidable impacts to scenic vistas due to its location west of Chase Drive, a City-designated scenic corridor; due to the extensive amount of grading and landform alteration required on site; and due to adverse effects to views of the Santa Ana Mountains from Chase Drive. However, these impacts would be reduced in comparison to the project evaluated in the SHP EIR due to the increase in open space areas by approximately 22.0%, the reduction in the amount of grading required on site, the reduction in the number of proposed residential dwelling units from 292 to 276 units, and due to mandatory compliance with the development standards and design guidelines set forth in the proposed Skyline Heights Specific Plan. Therefore, the proposed Project would result in reduced impacts to scenic vistas as compared to the significant and unavoidable impacts previously identified by the SHP EIR, although these impacts would remain significant and unavoidable with implementation of the proposed Project.

Based on the foregoing analysis, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR. b) Would the Project substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway? Skyline Heights Project EIR Findings: Significant and Unavoidable Impact. The SHP EIR found that although the SHP would alter the foothills of the Santa Ana Mountains, long-distance views of the mountains from Chase Avenue would remain. The SHP EIR found that there are no trees, rock outcroppings, or historic buildings designated in the area that would be affected by the SHP. Nonetheless, the SHP EIR found that due to the substantial modification of on-site topography and introduction of urban uses into an existing undeveloped area, impacts to scenic resources were disclosed as a significant and unavoidable impact. (Corona, 2015, pp. 4.A-15 to 4.A-16) EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. Consistent with the discussion presented above for Threshold a), the currently-proposed Project would result in reduced impacts to scenic resources in comparison to the project evaluated in the SHP EIR. Specifically, the proposed Project would decrease the number of dwelling units by 16 (from 292 to 276 units). It also would reduce the area of physical disturbance, with the Approved Project affecting approximately 170.70 acres of the property, while the proposed Project would disturb only 151.8 acres on site and approximately 7.0 acres off site, with the off-site impact areas mostly comprising developed/disturbed/ ornamental vegetation types. In general, the proposed Project's areas of disturbance would remain within the limits identified in the Approved Project. Furthermore, the proposed Project would increase open space (i.e., natural open space, manufactured slopes, drainage basins, and public/private parks) from 149.55 acres under the Approved Project to 182.48 acres under the proposed Project, which represents an increase of 22.0% compared to the Approved Project. Areas of additional open space include the southern portion of the property that is located at higher elevations. Moreover, the land uses proposed as part of the Project, including proposed residential and park uses, would be substantially consistent with the project

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Environmental Impact Report Addendum

evaluated in the SHP EIR. Furthermore, future development on site would be subject to compliance with the development standards and design guidelines contained in the proposed Skyline Heights Specific Plan, whereas the Approved Project was not subject to any approved specific plans. Based on these considerations, it can be concluded that the currently-proposed Project would result in an overall reduction in impacts to scenic resources visible from a State scenic highway as compared to the project evaluated in the SHP EIR.

Although the Project would result in reduced impacts to scenic resources visible within a State scenic highway, consistent with the findings of the SHP EIR the currently-proposed Project still would result in a significant and unavoidable impacts to scenic resources visible from a State scenic highway. Impacts to scenic highways would occur due to the Project site’s location west of Chase Drive, a City-designated scenic corridor; the extensive amount of grading and landform alteration required on site; and adverse effects to views of the Santa Ana Mountains from Chase Drive. However, these impacts would be reduced in comparison to the project evaluated in the SHP EIR due to the increase in open space areas by approximately 22.0%, the reduction in the amount of grading required on site, the reduction in the number of proposed residential dwelling units from 292 to 276 units, and due to mandatory compliance with the development standards and design guidelines set forth in the proposed Skyline Heights Specific Plan. Therefore, the proposed Project would result in reduced impacts to scenic resources visible within a State scenic highway as compared to the significant and unavoidable impacts previously identified by the SHP EIR, although these impacts would remain significant and unavoidable with implementation of the proposed Project.

Based on the foregoing analysis, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR. c) In non-urbanized areas, would the Project substantially degrade the existing visual character or quality of public views of the site and its surroundings? (Public views are those that are experienced from publicly accessible vantage point). If the Project is in an urbanized area, would the Project conflict with applicable zoning and other regulations governing scenic quality? Skyline Heights Project EIR Findings: Significant and Unavoidable Impact. The SHP EIR found that implementation of the SHP would alter the topography of the foothills of the Santa Ana Mountains. In addition, the SHP EIR found that the existing views would be altered with the development of 292 single-family residences. While the SHP EIR found that the SHP would incorporate project design features to minimize impacts, such as the clustering of residences, the SHP EIR found that the SHP would alter the visual character or quality of the site and its surroundings. Therefore, the SHP EIR found that the SHP would result in a significant and unavoidable impact to the visual character and quality of the site. (Corona, 2015, pp. 4.A-16 to 4.A-21) EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. The proposed Project would result in a substantial change to the visual character or quality of public views of the site and surroundings due to the extensive amount of grading required to implement the Project and due to the substantial change in the site’s character from open space to that of a master-planned residential community. However, the currently-proposed Project would result in reduced impacts related to visual character and quality as compared to the project evaluated in the SHP EIR. Specifically, the proposed Project would decrease the number of dwelling units by 16 (from 292 to 276 units). It also would reduce the area of physical disturbance, with the Approved Project affecting approximately 170.70 acres of the property, while the proposed Project would disturb only 151.8 acres on site and

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Environmental Impact Report Addendum

approximately 7.0 acres off site, with the off-site impact areas mostly comprising developed/disturbed/ ornamental vegetation types. In general, the proposed Project's areas of disturbance would remain within the limits identified in the Approved Project. Furthermore, the proposed Project would increase open space (i.e., natural open space, manufactured slopes, drainage basins, and public/private parks) from 149.55 acres under the Approved Project to 182.48 acres under the proposed Project, which represents an increase of 22.0% compared to the Approved Project. Areas of additional open space include the southern portion of the property that is located at higher elevations. Moreover, the land uses proposed as part of the Project, including proposed residential and park uses, would be substantially consistent with the project evaluated in the SHP EIR.

Furthermore, future development on site would be subject to compliance with the development standards and design guidelines contained in the proposed Skyline Heights Specific Plan, whereas the Approved Project was not subject to any approved specific plans. Based on these considerations, the currently-proposed Project would result in an overall reduction in impacts to scenic resources visible from a State scenic highway as compared to the project evaluated in the SHP EIR.

Although the Project would result in reduced impacts compared to the project evaluated by the SHP EIR, consistent with the findings of the SHP EIR, the currently-proposed Project still would result in a significant and unavoidable impacts to scenic resources visible from a State scenic highway. Impacts to scenic highways would occur due to the Project site’s location west of Chase Drive, a City-designated scenic corridor; the extensive amount of grading and landform alteration required on site; and adverse effects to views of the Santa Ana Mountains from Chase Drive. However, these impacts would be reduced in comparison to the project evaluated in the SHP EIR due to the increase in open space areas by approximately 22.0%, the reduction in the amount of grading required on site, the reduction in the number of proposed residential dwelling units from 292 to 276 units, and due to mandatory compliance with the development standards and design guidelines set forth in the proposed Skyline Heights Specific Plan. Therefore, the proposed Project would result in reduced impacts to scenic resources visible within a State scenic highway as compared to the significant and unavoidable impacts previously identified by the SHP EIR, although these impacts would remain significant and unavoidable with implementation of the proposed Project.

Based on the foregoing analysis, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR. d) Would the Project create a new source of substantial light or glare, which would adversely affect day or nighttime views in the area?
Skyline Heights Project EIR Findings: Less-than-Significant Impact. The SHP EIR found that implementation of the SHP would not create substantial light or glare which would adversely affect views in the area. Therefore, the SHP EIR found that the SHP would result in less-than-significant impacts with respect to light and glare.

EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. The Project site does not currently generate significant light or glare under existing conditions. Existing sources of light and glare in the surrounding area are mainly from exterior lighting associated with residential properties to the north and east and associated street lighting. The ambient nighttime lighting in the vicinity is typical of residential neighborhoods.

Consistent with the project evaluated in the SHP EIR, the proposed Project would introduce new sources of light due to the construction of 276 residential units, seven public/private parks, and streetlights along proposed onPage 3217 of 3613

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site roadways. These new light sources would include residential lighting on the houses, security lighting in yards and garages, streetlights, and vehicle headlights from Project-related traffic. The exteriors of the proposed homes are expected to be finished with a mix of materials such as stucco, brick, wood, and tile, similar to other existing homes in the area. At night, interior lighting and vehicle movement on the new streets would contribute additional light. However, and consistent with the findings of the SHP EIR, interior lighting from the residences is generally small-scale and well-contained, meaning it would not significantly affect nearby properties. Also consistent with the findings of the SHP EIR, the movement of vehicles within the development would be partially shielded by buffer walls and landscaping between the Project site and neighboring properties. Moreover, the total amount of lighting required on site would be reduced in comparison to what was assumed by the SHP EIR due to the reduction in the number of dwelling units from 292 dwelling units under the approved TTM 36544 to 276 dwelling units under the proposed TTM 36544R1.

Regarding street lighting, the City of Corona’s Municipal Code specifies standards for the design, placement, and operation of public lighting. It mandates that all lighting must be directed downward to minimize spillover onto adjacent properties, sensitive areas, and open space. This regulation ensures that any new development complies with lighting standards to prevent significant light pollution. Therefore, adherence to these guidelines, which are enforced during the approval process for the Project, would help minimize any potential impacts from street lighting.

In summary, the site is currently vacant and does not produce glare. Consistent with the findings of the SHP EIR, while the addition of new sources of lighting and reflective surfaces, such as windows, vehicles, and rooftops, may introduce new sources of light and glare to the Project area, due to the distance from neighboring homes, the site’s natural topography, and the similar lighting characteristics of the surrounding residential areas, impacts due to light and glare would be less than significant and reduced in comparison to the project evaluated in the SHP EIR. Based on the foregoing analysis, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.

2.2 Agriculture/Forestry Resources
New
Significant
Impact
More
Severe
Impacts
New Ability to
Substantially
Reduce Significant
Impact
No Substantial
Change from
Previous
Analysis
Would the Project:
a. Convert Prime Farmland, Unique Farmland, or
Farmland of Statewide Importance (Farmland), as
shown on the maps prepared pursuant to the
Farmland Mapping and Monitoring Program of the
California Resources Agency, to non-agricultural
use?
☐ ☐ ☐ ☒
b. Conflict with existing zoning for agricultural use, or a Williamson Act contract? ☐ ☐ ☐ ☒

SKYLINE HEIGHTS
Environmental Impact Report Addendum

New
Significant
Impact
More
Severe
Impacts
New Ability to
Substantially
Reduce Significant
Impact
No Substantial
Change from
Previous
Analysis
c. Conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public Resources Code
Section 12220(g)), timberland (as defined by Public
Resources Code Section 4526), or timberland
zoned Timberland Production (as defined by
Government Code Section 51104(g))?
☐ ☐ ☐ ☒
d. Result in the loss of forest land or conversion of
forest land to non-forest use? ☐ ☐ ☐ ☒
e. Involve other changes in the existing environment
which, due to their location or nature, could result
in conversion of Farmland, to non-agricultural use
or conversion of forest land to non-forest use?
☐ ☐ ☐ ☒

ENVIRONMENTAL ANALYSIS
a) Would the Project convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non-agricultural use? d) Would the Project result in the loss of forest land or conversion of forest land to non-forest use? e) Would the Project involve other changes in the existing environment which, due to their location or nature, could result in conversion of Farmland, to non-agricultural use or conversion of forest land to non-forest use?
Skyline Heights Project EIR Findings: Less-than-Significant Impact. The SHP EIR found that the SHP would not directly convert or otherwise result in the conversion of any existing agricultural land to non-agricultural uses, or forest land to non-forest use, and would not trigger a significant impact per the Land Evaluation and Site Assessment (LESA) Model. As such, the SHP EIR found that impacts related to conversion of farmland and forest land would be less than significant. (Corona, 2015, pp. 4.O-5 to 4.O-7) EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. No land designated as forest land exists within the Project boundaries, and therefore, implementation of the proposed Project would not directly convert any forest land to a non-forest use. Additionally, although the Cleveland National Forest is located to the west and south of the Project site, the proposed development would not affect any forest land or forestry resources. As such, and consistent with the findings of the SHP EIR, impacts related to the conversion of forest land would be less than significant.

The general conditions at the Project site have not substantially changed since with SHP EIR was certified. Based on the LESA model that was included as Appendix B to the SHP EIR, the final LESA score for the Project site was calculated at 21.79 points out of a possible 100 points, with a Land Evaluation score of 6.79 and a Site Assessment

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score of 15.00. The total LESA score is between 0 and 39 points, and both of the scores associated with the Land Evaluation factors and the Site Assessment factors were below the threshold of 20 points, indicating that soils on the Project site are not considered to comprise Farmland. Therefore, and consistent with the conclusion reached by the SHP EIR, the proposed Project would not convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland) to non-agricultural use, and impacts would be less than significant. Additionally, due to the lack of agricultural activities in the local area, the Project also would have no potential to result in indirect impacts to existing agricultural uses, and as such impacts due to the conversion of Farmland to a nonagricultural use also would be less than significant.

Based on the foregoing analysis, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR. b) Would the Project conflict with existing zoning for agricultural use, or a Williamson Act contract? c) Would the Project conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public Resources Code Section 1220(g)), timberland (as defined by Public Resources Code Section 4526), or timberland zoned Timberland Production (as defined by Government Code Section 51104(g))? Skyline Heights Project EIR Findings: Less-than-Significant Impact. The SHP EIR found that the SHP would not conflict with existing zoning for agricultural uses or forest land or a Williamson Act contract, and concluded that impacts in this regard would be less than significant. (Corona, 2015, pp. 4.O-7 and 4.O-8) EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. The Project site is currently zoned Single-Family Residential (R-1-7.2), with a minimum lot size of 7,200 square feet. No portion of the Project site currently is zoned for agricultural or forestry uses, and the proposed Skyline Heights Specific Plan would not result in any changes to the site’s existing zoning classifications. Additionally, no lands surrounding the Project site are zoned primarily for agricultural uses under existing conditions. Therefore, the proposed Project would not conflict with zoning for agricultural use and would not conflict with existing zoning of forest land, timberland, or timberland zoned Timberland Production. Accordingly, and consistent with the findings of the SHP EIR, Project impacts due to a conflict with existing zoning for agricultural or forestry uses would be less than significant.

According to mapping information available from Riverside County Geographic Information Systems (GIS), no portion of the Project site is located within an Agricultural Preserve. The nearest lands located within an Agricultural Preserve occur approximately 642 feet to the south of the southeastern corner of the Project site (Tin Mine Canyon 1 Agricultural Preserve). Under the State Williamson Act, only lands within a County-adopted Agricultural Preserve are eligible for a Williamson Act contract. Accordingly, the Project site is not subject to any Williamson Act contracts, and the Project therefore would have no potential to conflict with any Williamson Act contracts affecting the Project site. Additionally, although the Tin Mine Canyon 1 Agricultural Preserve is located approximately 642 feet south of the Project site, a review of aerial photographs shows that these lands only appear to be used for dryland farming. Due to the distance between the Project site and the Tin Mine Canyon 1 Agricultural Preserve and because agricultural activities within the Tin Mine Canyon 1 Agricultural Preserve are limited to dryland farming, the residential uses proposed as part of the Project would have no potential to result in a conflict with existing agricultural uses within the Tin Mine Canyon 1 Agricultural Preserve. Consistent with the findings of the SHP EIR, impacts would be less than significant. (RCIT, n.d.; Google Earth, 2024)

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Environmental Impact Report Addendum

Based on the foregoing analysis, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.

2.3 Air Quality
New
Significant
Impact
More
Severe
Impacts
New Ability to
Substantially
Reduce Significant
Impact
No Substantial
Change from
Previous
Analysis
Would the Project:
a. Conflict with or obstruct implementation of the
applicable air quality plan? ☐ ☐ ☐ ☒
b. Violate any air quality standard or contribute
substantially to an existing or projected air quality
violation?
☐ ☐ ☐ ☒
c. Result in a cumulatively considerable net increase
of any criteria pollutant for which the project
region is nonattainment under an applicable
federal or state ambient air quality standard
(including release of emissions which exceed
quantitative thresholds for ozone precursors)?
☐ ☐ ☐ ☒
d. Expose sensitive receptors to substantial pollutant
concentrations? ☐ ☐ ☐ ☒
e. Create objectionable odors that would affect a
substantial number of people? ☐ ☐ ☐ ☒
f. Conflict with any applicable plan, policy, or
regulation of an agency with jurisdiction over the
project (including, but not limited to, the general
plan and municipal code) adopted for the purpose
of avoiding or mitigating an environmental effect?
☐ ☐ ☐ ☒

ENVIRONMENTAL ANALYSIS
In order to evaluate the proposed Project’s potential to result in significant air quality impacts, a Project-specific technical study was prepared for the Project by Urban Crossroads, Inc. (herein, “UC”). This report is titled, “Skyline Heights Air Quality and Greenhouse Gas Assessment” (herein, “AQ/GHG Assessment”), is dated February 14, 2024, and is included as Technical Appendix C to this EIR Addendum (UC, 2024). It should be noted that the Project’s AQ/GHG Assessment evaluates the Project’s potential air quality and greenhouse gas (GHG) emissions assuming buildout of the 276 dwelling units accommodated by proposed TTM 36544R1. Furthermore, environmental effects associated with development of the Project site with up to 292 dwelling units previously were fully evaluated as part of the SHP EIR. Accordingly, the focus of this subsection is on the current Project’s potential impacts due to air quality emissions in comparison to what was evaluated and disclosed by the SHP EIR based on a reduction in the number of proposed units from 292 units as evaluated by the SHP EIR to 276 units under the proposed Project.

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a) Would the Project conflict with or obstruct implementation of the applicable air quality plan? Skyline Heights Project EIR Findings: Less-than-Significant Impact. The SHP EIR found that implementation of the SHP would not conflict or obstruct implementation of the South Coast Air Quality Management District (SCAQMD) Air Quality Management Plan (AQMP). Thus, the SHP EIR concluded that the SHP would result in a lessthan-significant impact. (Corona, 2015, pp. 4.B-25 to 4.B-27) EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. The Project site is located within the South Coast Air Basin (SCAB), which is characterized by relatively poor air quality. The SCAQMD has jurisdiction over an approximately 10,743 square-mile area consisting of the four-county Basin and the Los Angeles County and Riverside County portions of what use to be referred to as the Southeast Desert Air Basin. In these areas, the SCAQMD is principally responsible for air pollution control, and works directly with the Southern California Association of Governments (SCAG), county transportation commissions, local governments, as well as State and federal agencies to reduce emissions from stationary, mobile, and indirect sources to meet State and federal ambient air quality standards. Currently, these State and federal air quality standards are exceeded in most parts of the SCAB. In response, the SCAQMD has adopted a series of AQMPs to meet the state and federal ambient air quality standards. AQMPs are updated regularly in order to more effectively reduce emissions, accommodate growth, and to minimize any negative fiscal impacts of air pollution control on the economy. (UC, 2024, p. 20) In December 2022, and subsequent to certification of the SHP EIR, the SCAQMD released the Final 2022 AQMP.

The 2022 AQMP continues to evaluate current integrated strategies and control measures to meet the California Ambient Air Quality Standards (CAAQS), as well as explore new and innovative methods to reach its goals. Some of these approaches include utilizing incentive programs, recognizing existing co-benefit programs from other sectors, and developing a strategy with fair-share reductions at the federal, State, and local levels. Similar to the 2012 AQMP that was evaluated by the SHP EIR, the 2022 AQMP incorporates scientific and technological information and planning assumptions, including the 2020-2045 Regional Transportation Plan/Sustainable Communities Strategy (2020-2045 RTP/SCS). The 2020-2045 RTP/SCS was approved on April 4, 2024, subsequent to certification of the SHP EIR, and is a planning document that supports the integration of land use and transportation to help the region meet the federal metropolitan planning organization (MPO) requirements under the Sustainable communities and Climate Protection Act. The proposed Project would be developed in accordance with all applicable rules and regulations contained in those plans. (UC, 2024, p. 20) The Project’s consistency with the AQMP will be determined using the 2022 AQMP. Criteria for determining consistency with the AQMP are defined in Chapter 12, Section 12.2 and Section 12.3 of the 1993 CEQA Handbook.

These indicators are discussed below. (UC, 2024, p. 20) • Consistency Criterion No. 1: Potential to 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 AQMP.

The violations under this criterion refer to the California Ambient Air Quality Standards (CAAQS) and National Ambient Air Quality Standards (NAAQS). CAAQS and NAAQS violations would occur if Regional or localized significance thresholds were exceeded. As discussed under the analyses of Thresholds b), c), and d) below, the Project’s Regional and localized construction and operational-source emissions would not exceed any of the

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SCAQMD’s Regional or localized significance thresholds. As such, the proposed Project would 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 AQMP. On the basis of the preceding discussion, the Project is determined to be consistent with the first criterion. (UC, 2024, pp. 20-21)
• Consistency Criterion No. 2: Potential to exceed the assumptions in the AQMP based on the years of Project build‐out phase.

The 2022 AQMP demonstrates that the applicable ambient air quality standards can be achieved within the timeframes required under federal law. Growth projections from local general plans adopted by cities in the district are provided to the SCAG, which develops regional growth forecasts, which are then used to develop future air quality forecasts for the AQMP. Development consistent with the growth projections in City of Corona General Plan is considered to be consistent with the AQMP. (UC, 2024, p. 21) Peak day emissions generated by construction activities are largely independent of land use assignments, but rather are a function of development scope and maximum area of disturbance. Irrespective of the site’s land use designation, development of the site to its maximum potential would likely occur, with full disturbance of the portions of the site proposed for development occurring during construction activities. As such, when considering that no emissions thresholds would be exceeded, the Project’s construction emissions would not exceed the assumptions in the AQMP. (UC, 2024, p. 21)
As previously shown on Figure 2, and as described herein in Subsection 1.1, the City of Corona previously approved GPA13-003, which redesignated the 249.39-acre Project site for “Low Density Residential (3-6 dwelling units/acre)” land uses. As noted above, the AQMP bases its growth forecasts, in part, on the land use designations provided in each local jurisdiction’s General Plan. The site’s adopted General Plan land use designation allows for development of the Project site at a maximum density of 3-6 dwelling units per acre (du/ac). Thus, based on the site’s adopted General Plan land use designation, the AQMP assumed development of the 249.39-acre Project site with up to 1,496 dwelling units (249.39 acres x 6 du/ac = 1,496.34 du).

The Project Applicant is proposing a revision to the previously-approved Tentative Tract Map (TTM 36544R1), which would reduce the number of dwelling units allowed on site by 16 units, from 292 units under the Approved Project to 276 dwelling units under the proposed Project. Specifically, TTM 36544R1 would subdivide the Project site to provide for 92 single family-detached housing units on minimum 7,200 square foot lots, three custom singlefamily lots, 104 eight-cluster single-family detached housing units, and 77 four-cluster single-family detached housing units. The proposed 276 residential units would occur in the same general location as previously-approved 292 dwelling units, and all of the dwelling units that are proposed as part of TTM 36544R1 are located within the portions of the Project site that are designated by the General Plan for “Low Density Residential (3-6 dwelling units/acre)” and zoned for R-1-7.2 (single-family residential, 7,200 square-foot minimum lot size). The 276 dwelling units proposed under the Project is far less than the 1,496 dwelling units allowed on site based on the site’s existing “Low Density Residential (3-6 dwelling units/acre)” land use designation.

Thus, given that the 2022 AQMP relies on growth inputs based on the existing General Plan land use designations for the various jurisdictions within the SCAB region, and because the proposed Project includes far fewer dwelling

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units than otherwise is allowed based on the site’s adopted “Low Density Residential (3-6 dwelling units/acre)” land use designation, the proposed Project would not exceed the assumptions in the 2022 AQMP based on the years of Project build-out phase. Accordingly, the proposed Project would be consistent with the 2022 AQMP based on this criterion.

Conclusion
Consistent with the conclusion reached by the SHP EIR, because the proposed Project is consistent with site’s land use designations, would not exceed any applicable regional or local thresholds, and would not result in or cause NAAQS or CAAQS violations, the Project is therefore considered to be consistent with the 2022 AQMP and a lessthan-significant impact is expected. Therefore, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.
b) Would the Project violate any air quality standard or contribute substantially to an existing or projected air quality violation?
c) Would the Project result in a cumulatively considerable net increase of any criteria pollutant for which the region is nonattainment under an applicable federal or state ambient air quality standard (including release of emissions which exceed quantitative thresholds for ozone precursors)? Skyline Heights Project EIR Findings: Less-than-Significant Impact. The regional significance analysis for construction and operational emissions as provided in the SHP EIR demonstrated that emissions would be below the regional significance thresholds. Therefore, the SHP EIR found that implementation of the SHP would not violate any air quality standard, would not result in a cumulatively considerable net increase of any criteria pollutant for which the region is nonattainment under an applicable federal or State ambient air quality standard (including releasing emissions which exceed quantitative thresholds for ozone precursors), and would not contribute substantially to an existing or projected air quality violation. (Corona, 2015, pp. 4.B-27 to 4.B-32) EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. Both the U.S. Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) have established ambient air quality standards for common pollutants. These ambient air quality standards are levels of contaminants representing safe levels that avoid specific adverse health effects associated with each pollutant. The ambient air quality standards cover what are called “criteria” pollutants because the health and other effects of each pollutant are described in criteria documents. The six criteria pollutants are ozone (O3) (precursor emissions include NOX and reactive organic gases [ROG]), Carbon Monoxide (CO), particulate matter smaller than 10 microns (PM10), particulate matter smaller than 2.5 microns (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), and lead. Areas that meet ambient air quality standards are classified as attainment areas, while areas that do not meet these standards are classified as nonattainment areas. The Riverside County portion of the SCAB is designated as a nonattainment area for the federal O3 and PM2.5 standards and is also a nonattainment area for the State standards for O3, PM10, and PM2.5. (UC, 2024, p. 6)
The SCAQMD has developed regional significance thresholds for criteria pollutants, as summarized in Table 3, Maximum Daily Regional Emissions Thresholds. The SCAQMD’s CEQA Air Quality Significance Thresholds (March 2023) indicate that any projects in the South Coast Air Basin (SCAB) with daily emissions that exceed any of the

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indicated thresholds should be considered as having an individually and cumulatively significant air quality impact. (UC, 2024, p. 10)
Table 3 Maximum Daily Regional Emissions Thresholds
Pollutant Construction Operations
NOX 100 lbs/day 55 lbs/day
VOC 75 lbs/day 55 lbs/day
PM10 150 lbs/day 150 lbs/day
PM2.5 55 lbs/day 55 lbs/day
SOX 150 lbs/day 150 lbs/day
CO 550 lbs/day 550 lbs/day
(UC, 2024, Table 1)
The proposed Project has the potential to exceed the SCAQMD Regional Thresholds during both near-term construction activities and long-term operation. Provided below is a discussion of the assumptions and modeling inputs for the Project’s construction and operational phases, along with an evaluation as to whether the proposed Project would exceed any of the SCAQMD Regional thresholds identified in Table 3 and a comparison of the proposed Project’s construction and operational emissions to the emission levels reported by the SHP EIR for the Approved Project.

Regional Construction-Related Emissions
Construction activities associated with the Project would result in emissions of VOCs, NOX, SOX, CO, PM10, and PM2.5. Construction-related emissions are expected from the following construction activities: demolition, site preparation, grading/blasting, building construction, paving, and architectural coating. Each is briefly discussed below. (UC, 2024, pp. 11-12)
Construction Modeling Inputs and Assumptions
Grading Activities
Dust is typically a major concern during grading activities. Because such emissions are not amenable to collection and discharge through a controlled source, they are called “fugitive emissions.” Fugitive dust emissions rates vary as a function of many parameters (soil silt, soil moisture, wind speed, area disturbed, number of vehicles, depth of disturbance or excavation, etc.). The California Emissions Estimator Model (CalEEMod) was utilized to calculate fugitive dust emissions resulting from this phase of activity. Per client provided data, this analysis assumes that earthwork activities are expected to balance on site and no import or export of soils would be required.

Blasting Activities
The Project site may require blasting. While the need for blasting is not known at this point, the emissions effects of blasting are included in this analysis. For modeling purposes, it is anticipated no more than two blasting events could occur per day for logistics and safety reasons. The estimated emissions of NOX, CO, and SOX from explosives used for blasting were determined using emission factors in Section 13.3 (Explosives Detonation) of AP-42, Compilation of Air Emissions Factors from Stationary Sources, and PM10 and PM2.5 emissions were determined using Section 11.9 of AP-42. According to AP-42, “Unburned hydrocarbons also result from explosions, but in most instances, methane is the only species that has been reported”; methane is not a VOC, and a methane emission

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factor has not been determined for ammonium nitrate/fuel oil (ANFO). While equipment emissions are included in overall construction emission estimates blasting activities would limit onsite activity for safety reasons and no other significant activities would occur on the same day other than a few pieces of equipment supporting the blasting activity. Blast emissions are based on a maximum of 1-ton ANFO per day for CO, NOX, and SO2, PM10, and PM2.5 emissions estimates are conservative and assuming the entire 123.0 acres of the Project site proposed for grading as the blast areas. Blasting is anticipated to result in 0.84 pounds (lbs.) of CO, 0.21 lbs. of NOX, 0.03 lbs. of SO2, 10.3 lbs. of PM10, and 6.12 lbs. of PM2.5 per day. (UC, 2024, p. 12) On-Road Trips
Construction generates on-road vehicle emissions from vehicle usage for workers, vendors, and haul trucks commuting to and from the site. Worker and hauling trips are based on the CalEEMod defaults. It should be noted that for vendor trips, specifically, CalEEMod only assigns vendor trips to the Building Construction phase. Vendor trips would likely occur during all phases of construction. As such, the CalEEMod defaults for vendor trips have been adjusted based on a ratio of the total vendor trips to the number of days of each subphase of activity. (UC, 2024, p. 12)
Construction Duration
For purposes of analysis, construction of Project is expected to commence in January 2025 and would last through December 2028, as summarized in Table 4, Construction Duration. The construction schedule utilized in the analysis represents a “worst-case” analysis scenario should construction occur any time after the respective dates since emission factors for construction decrease as time passes and the analysis year increases due to emission regulations becoming more stringent2
. The duration of construction activity and associated equipment represents a reasonable approximation of the expected construction fleet as required per CEQA Guidelines. (UC, 2024, pp. 12-13)
Table 4 Construction Duration
Phase Name Start Date End Date Days
Demolition 1/7/2025 1/13/2025 5
Site Preparation 1/14/2025 2/21/2025 29
Grading/Blasting 2/24/2025 2/27/2026 265
Building Construction 3/2/2026 12/29/2028 740
Paving 2/28/2028 12/29/2028 220
Architectural Coating 4/26/2027 12/29/2028 440
(UC, 2024, Table 3)
Construction Equipment
As shown on Table 5, Construction Equipment, equipment based on Project Applicant provided data have been used. Consistent with industry standards and typical construction practices, each piece of equipment will operate up to a total of eight (8) hours per day, or more than two-thirds of the period during which construction activities are allowed pursuant to the code. (UC, 2024, p. 13)
2 As shown in the CalEEMod User’s Guide Version 2022.1, Section 4.3 “Off-Road Equipment” as the analysis year increases, emission factors for the same equipment pieces decrease due to the natural turnover of older equipment being replaced by newer less polluting equipment and new regulatory requirements.

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Table 5 Construction Equipment
Activity Equipment Amount Hours Per Day
Demolition
Concrete/Industrial Saws 1 8
Excavators 2 8
Rubber Tired Dozers 1 8
Site Preparation
Rubber Tired Dozers 1 8
Crawler Tractors 2 8
Grading
Excavators 3 8
Graders 2 8
Rubber Tired Dozers 2 8
Scrapers 8 8
Crawler Tractors 4 8
Building Construction
Cranes 2 8
Forklifts 5 8
Generator Sets 2 8
Tractors/Loaders/Backhoes 5 8
Welders 2 8
Paving
Pavers 2 8
Paving Equipment 2 8
Rollers 2 8
Architectural Coating Air Compressors 1 8
(UC, 2024, Table 4)
Regional Construction Emissions Summary
The proposed Project’s estimated maximum daily construction emissions without mitigation are summarized in Table 6, Proposed Project Regional Construction Emissions Summary. Detailed construction model outputs are presented in Attachment A to the Project’s AQ/GHG Assessment (Technical Appendix C). Under the assumed scenarios, emissions resulting from construction of the proposed Project would not exceed thresholds established by the SCAQMD for emissions of any criteria pollutant. Therefore, and consistent with the findings of the SHP EIR, the proposed Project would result in less-than-significant regional air quality impacts during construction and no mitigation would be required. (UC, 2024, p. 14)
For purposes of disclosure, Table 7, Original Project Construction Emissions Summary, shows the construction emissions summary for the Approved Project as reported by the SHP EIR, while Table 8, Comparison of Regional Construction Emissions – Approved Project vs. Proposed Project, compares the proposed Project’s regional construction emissions to the regional construction emissions reported by the SHP EIR for the Approved Project.

As shown, in comparison to the Approved Project, the proposed Project would result in a slight decrease in daily construction emissions of VOC, NOX, and PM2.5, and would result in a slight increase in daily emissions of CO, SO2, and PM10. The increase in emissions of CO, SO2, and PM10 likely is the result of changes to the CalEEMod emission factors and modeling assumptions, given that there has been no change in the Project’s construction-related characteristics other than a reduction in areas proposed for grading and a reduction in the number of proposed dwelling units. Additionally, the proposed Project’s emissions of CO, SO2, and PM10 would be far below the SCAQMD Regional thresholds for these pollutants, as shown in Table 6. Accordingly, and consistent with the conclusion reached by the SHP EIR, construction-related Regional air quality emissions associated with the proposed Project would not violate any air quality standard or contribute substantially to an existing or projected air quality violation and would not result in a cumulatively-considerable net increase of any criteria pollutant for

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Table 6 Proposed Project Regional Construction Emissions Summary Source Emissions (lbs/day)
VOC NOX CO SOX PM10 PM2.5
Summer
2025 10.18 92.17 84.19 0.19 11.20 5.99
2026 2.57 20.70 32.53 0.05 2.24 1.05
2027 12.28 20.90 34.75 0.05 2.45 1.07
2028 12.93 26.56 45.03 0.07 2.82 1.28
Winter
2025 10.17 92.21 83.29 0.19 11.20 5.99
2026 9.68 84.49 81.04 0.19 10.85 5.66
2027 12.25 20.99 32.83 0.05 2.45 1.07
2028 12.89 26.65 43.01 0.07 2.82 1.28
Maximum Daily Emissions 12.93 92.21 84.19 0.19 11.20 5.99 SCAQMD Regional Threshold 75 100 550 150 150 55
Threshold Exceeded? No No No No No No
1PM10 and PM2.5 source emissions reflect 3x daily watering per SCAQMD Rule 403 for fugitive dust. (UC, 2024, Table 5)
Table 7 Original Project Construction Emissions Summary Source
Emissions (pounds per day)
VOC NOX CO SO2 PM10 PM2.5
Site Preparation 5.34 56.98 43.77 0.04 1.18 6.77
Grading 6.89 79.15 52.1 0.06 7.24 4.97
Paving 2.15 22.45 15.67 0.02 1.43 1.21
Building Construction 3.68 29.19 26.02 0.05 3.2 2.09
Architectural Coatings 54.9 1.59 2.59 0.01 0.33 0.16
Maximum Daily Emissionsa 54.9 79.15 52.1 0.06 7.24 6.77 Significance Threshold 75 100 550 150 150 55
Significant Impact? No No No No No No
a. The maximum daily emissions refer to the maximum emissions that would occur in one day; it was assumed that the grading activities do not occur at the same time as the other construction activities; therefore, their emissions are not summed.
(Corona, 2015, Table 4.B-6)
Table 8 Comparison of Regional Construction Emissions – Approved Project vs. Proposed Project
Source
Emissions (pounds per day)
VOC NOX CO SO2 PM10 PM2.5
Proposed Project 12.93 92.21 84.19 0.19 11.20 5.99
Approved Project 54.9 79.15 52.1 0.06 7.24 6.77
Net Emissions (Proposed – Approved) -41.97 -13.06 +32.09 +0.13 +3.96 -0.78 which the region is nonattainment under an applicable federal or State ambient air quality standard. Impacts would be less than significant. Therefore, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.

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Regional Operational-Related Emissions
Proposed Project Regional Operational Emissions Summary Operational activities associated with the Project would result in emissions of VOCs, NOX, CO, SOX, PM10, and PM2.5.

Operational-related emissions are expected from the following primary sources: area source emissions, energy source emissions, and mobile source emissions. (UC, 2024, p. 15) The Project-related operational air quality impacts primarily would result from vehicle trips generated by the Project. Trip characteristics available from the Project’s Traffic Analysis (“TA”; included herein as Technical Appendix J) were utilized in the analysis. (UC, 2024, p. 15)
The estimated operation-source emissions for the proposed Project are summarized in Table 9, Proposed Project Regional Operational Emissions Summary. Detailed operation model outputs are presented in Attachment A to the Project’s AQ/GHG Assessment (Technical Appendix C). As shown on Table 9, operational-source emissions associated with the proposed Project would not exceed the applicable SCAQMD regional thresholds for emissions of any criteria pollutant. Thus, and consistent with the finding reached by the SHP EIR, long-term operation of the proposed Project would not violate any air quality standard or contribute substantially to an existing or projected air quality violation, and impacts would be less than significant. (UC, 2024, p. 15) Table 9 Proposed Project Regional Operational Emissions Summary Source Emissions (lbs/day)
VOC NOX CO SOX PM10 PM2.5
Summer
Mobile Source 10.27 10.55 103.14 0.28 25.80 6.68
Area Source 14.07 4.73 17.63 0.03 0.38 0.38
Energy Source 0.15 2.48 1.05 0.02 0.20 0.20
Total Maximum Daily Emissions 24.49 17.76 121.83 0.33 26.37 7.25 SCAQMD Regional Threshold 55 55 550 150 150 55
Threshold Exceeded? No No No No No No
Winter
Mobile Source 9.68 11.31 85.55 0.26 25.80 6.68
Area Source 12.71 4.58 1.95 0.03 0.37 0.37
Energy Source 0.15 2.48 1.05 0.02 0.20 0.20
Total Maximum Daily Emissions 22.53 18.37 88.56 0.31 26.37 7.25 SCAQMD Regional Threshold 55 55 550 150 150 55
Threshold Exceeded? No No No No No No
(UC, 2024, Table 7)
Skyline Heights EIR Regional Operational Emissions Summary As previously noted, the SHP EIR assumed development of the Project site with up to 292 single-family residential dwelling units. Table 10, SHP EIR Regional Operational Emissions Summary, shows the Regional emissions summary for the Approved Project as reported by the SHP EIR. As shown in Table 10, the SHP EIR determined that

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Table 10 SHP EIR Regional Operational Emissions Summary Source
Emissions (pounds per day)
VOC NOX CO SO2 PM10 PM2.5
Area 12.70 0.28 24.09 0.00 0.46 0.46
Energy 0.23 1.97 0.84 0.01 0.16 0.16
Mobile 8.43 23.08 91.35 0.31 21.69 6.08
Maximum Daily Emissionsa 21.36 25.33 116.28 0.33 22.31 6.70 Significance Threshold 55 55 550 150 150 55
Significant Impact? No No No No No No
a The maximum daily emissions refer to the maximum emissions that would occur in one day. (Corona, 2016, Table 4.8-7)
the Approved Project’s operational-related emissions would be below all of the SCAQMD Regional thresholds of significance. Thus, the SHP EIR concluded that the Approved Project would have a less-than-significant impact due to regional air quality emissions.

Approved Project Updated Regional Emissions Summary
The Regional air quality emissions calculations presented in the SHP EIR were based on CalEEMod version 2013.2.2.

Since preparation of the Draft SHP EIR, the CalEEMod software has undergone numerous updates to more accurately calculate air quality emissions for development projects. Accordingly, the Regional air quality emissions for the Approved Project were calculated with CalEEMod version 2022.1.1.21, which was released by the California Air Pollution Control Officers Association (CAPCOA) in 2022. The updated calculations were prepared in order to present a comparison between the air quality emissions associated with the Approved Project and the proposed Project using the same version of the CalEEMod modeling software, which is an “apples to apples” comparison, and uses the most accurate and current information. Table 11, Updated Approved Project Regional Operational Emissions, presents the Approved Project’s Regional air quality emissions based on CalEEMod version 2022.1.1.21 and buildout of the Project site with 292 single-family residential dwelling units3 . Detailed operation model outputs
for the Approved Project are presented in Attachment B to the Project’s AQ/GHG Assessment (Technical Appendix C). (UC, 2024, p. 15)
Regional Operational Emissions Comparison – Approved Project vs. Proposed Project Table 12, Regional Emissions Comparison – SHP EIR vs. Proposed Project, presents a comparison between the Regional operational emissions reported by the SHP EIR to the proposed Project’s emissions. As shown, the proposed Project would result in a slight reduction in emissions of VOC and NOX, and a slight increase in emissions of CO, SOX, PM10, and PM2.5. The increase in emissions of CO, SOX, PM10, and PM2.5 likely is the result of changes to the CalEEMod emission factors and modeling assumptions, given that there has been no change in the Project’s operational-related characteristics other than a reduction in the number of proposed dwelling units from 292 units under the Approved Project to 276 units3 under the proposed Project. However, the proposed Project’s emissions

3 It should be noted that although the Project Applicant is proposing to develop the site with only 276 dwelling units, the Project’s AQ/GHG Assessment assumes the Project site would be developed with up to 292 dwelling units; thus, the Project’s AQ/GHG Analysis provides a “worst-case” analysis of the Project’s potential impacts due to air quality and greenhouse gas emissions.

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Table 11 Updated Approved Project Regional Operational Emissions Source Emissions (lbs/day)
VOC NOX CO SOX PM10 PM2.5
Summer
Mobile Source 10.91 11.21 109.58 0.30 27.41 7.10
Area Source 14.89 5.00 18.66 0.03 0.40 0.40
Energy Source 0.15 2.62 1.12 0.02 0.21 0.21
Total Maximum Daily Emissions 25.96 18.83 129.36 0.35 28.02 7.71 SCAQMD Regional Threshold 55 55 550 150 150 55
Threshold Exceeded? No No No No No No
Winter
Mobile Source 10.28 12.02 90.90 0.28 27.41 7.10
Area Source 13.44 4.84 2.06 0.03 0.39 0.39
Energy Source 0.15 2.62 1.12 0.02 0.21 0.21
Total Maximum Daily Emissions 23.88 19.49 94.07 0.33 28.01 7.70 SCAQMD Regional Threshold 55 55 550 150 150 55
Threshold Exceeded? No No No No No No
(UC, 2024, Table 6)
Table 12 Regional Emissions Comparison – SHP EIR vs. Proposed Project Source
Peak Emissions (lbs/day)
VOC NOX CO SOX PM10 PM2.5
Proposed Project 24.49 18.37 121.83 0.33 26.37 7.25
Approved Project 54.90 79.15 52.10 0.06 7.24 6.77
Net Emissions (Proposed - Approved) -30.41 -60.78 +69.73 +0.27 +19.13 +0.48 of CO, SOX, PM10, and PM2.5 would be far below the SCAQMD Regional thresholds for these pollutants, as shown in Table 9.

Table 13, Updated Emissions Comparison – Approved Project vs. Proposed Project, presents a comparison of the air quality emissions associated with the Approved Project and the proposed Project using the same version of the CalEEMod modeling software. As shown, and would be expected from the less intense Project, the proposed Project is anticipated to generate fewer emissions per day for VOC, NOX, CO, SOX, PM10, and PM2.5 as compared to emissions generated by the Approved Project. (UC, 2024, p. 16) Conclusion - Regional Operational Emissions
As demonstrated in Table 9 and Table 13, the proposed Project would result in Regional air quality emissions that are well below the SCAQMD Regional thresholds of significance, and when comparing emissions between the Approved Project and proposed Project using the same version of the CalEEMod modeling software, the proposed Project would result in a reduction in emissions of all criteria air pollutants. Accordingly, and consistent with the conclusion reached by the SHP EIR, operational-related Regional air quality emissions associated with the proposed Project would not violate any air quality standard or contribute substantially to an existing or projected

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Table 13 Updated Emissions Comparison – Approved Project vs. Proposed Project Source Emissions (lbs/day)
VOC NOX CO SOX PM10 PM2.5
Summer
Proposed Project 24.49 17.76 121.83 0.33 26.37 7.25
Approved Project 25.96 18.83 129.36 0.35 28.02 7.71
Net Emissions (Proposed - Approved) -1.47 -1.08 -7.52 -0.02 -1.64 -0.45 Winter
Proposed Project 22.53 18.37 88.56 0.31 26.37 7.25
Approved Project 23.88 19.49 94.07 0.33 28.01 7.70
Net Emissions (Proposed - Approved) -1.35 -1.12 -5.52 -0.02 -1.64 -0.45 (UC, 2024, Table 8)
air quality violation and would not result in a cumulatively-considerable net increase of any criteria pollutant for which the region is nonattainment under an applicable federal or State ambient air quality standard. Impacts would be less than significant. Therefore, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.
d) Would the Project expose sensitive receptors to substantial pollutant concentrations? Skyline Heights Project EIR Findings: Less-than-Significant Impact. The SHP EIR found that implementation of the SHP would not expose sensitive receptors to substantial pollutant concentrations during operational or construction activities. The SHP EIR found that construction and operation of the SHP would not result in emissions that exceed the localized significance thresholds, and that the SHP would not cause or contribute to the formation of CO hotspots. The SHP EIR also found that construction and operation of the SHP would not expose sensitive receptors to substantial sources of Toxic Air Contaminant (TAC) emissions. Therefore, the SHP EIR found that construction and operation of the SHP would be less than significant. (Corona, 2015, pp. 4.B-32 to 4.B-35) EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. During both construction and operation, the Project has the potential to expose nearby sensitive receptors to substantial pollutant concentrations. The following provides an analysis based on the applicable Localized Significance Thresholds (LSTs) established by the State of California and SCAQMD and an analysis of the Project’s potential to result in or contribute to CO “hot spots.”
Localized Significance Thresholds
The analysis of Project impacts due to localized emissions uses the methodology included in the SCAQMD Final Localized Significance Threshold Methodology (LST Methodology). The SCAQMD has established that impacts to air quality are significant if there is a potential to contribute or cause localized exceedances of the federal and/or State ambient air quality standards (NAAQS/CAAQS). Collectively, these are referred to as Localized Significance Thresholds (LSTs). The SCAQMD established LSTs in response to the SCAQMD Governing Board’s Environmental

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Justice Initiative I-44. LSTs represent the maximum emissions from a project that will not cause or contribute to an exceedance of the most stringent applicable federal or state ambient air quality standard at the sensitive receptor.

The SCAQMD states that lead agencies can use the LSTs as another indicator of significance in its air quality impact analyses. (UC, 2024, p. 17)
Sensitive Receptors
The SCAQMD recommends that the nearest sensitive receptor be considered when determining a project’s potential to cause an individual or cumulatively significant impact. The nearest land use where an individual could remain for 24 hours to the Project site has been used to determine localized construction and operational air quality impacts for emissions of PM10 and PM2.5 (since PM10 and PM2.5 thresholds are based on a 24-hour averaging time). The nearest receptor used for evaluation of localized impacts of PM10 and PM2.5 is location R3 represented by the existing residence at 1490 Clearview Circle, approximately 53 feet (16 meters) east of the Project site (refer to Figure 8, Sensitive Receptor Locations). (UC, 2024, p. 17) Consistent with LST Methodology, the nearest industrial/commercial use to the Project site is used to determine construction and operational LST air impacts for emissions of NOX and CO as the averaging periods for these pollutants are shorter (8 hours or less) and it is reasonable to assume that an individual could be present at these sites for periods of one to 8 hours. Based on review of the Project area, construction activity surrounds the Project site. As such, it can be assumed that an individual can be present at these construction areas for a period of 8 hours. It should be noted that the existing residence (Location R3 as shown on Figure 8) is located at a closer distance than the nearest industrial/commercial use. As such, Location R3 also was be used for evaluation of localized NOX and CO impacts. (UC, 2024, p. 17)
It should be noted that the LST Methodology explicitly states that “It is possible that a project may have receptors closer than 25 meters. Projects with boundaries located closer than 25 meters to the nearest receptor should use the LSTs for receptors located at 25 meters.” As such, a 25-meter distance has been used for evaluation of localized PM10, PM2.5, NOX, and CO. (UC, 2024, pp. 17-18)
Localized Construction Emissions
Table 14, Project Localized Construction Emissions, identifies the localized impacts at the nearest receptor location in the vicinity of the Project. Outputs from the model runs for construction LSTs are provided in Attachment A to the Project’s AQ/GHG Assessment (Technical Appendix C). For analytical purposes, emissions associated with peak demolition, site preparation, and grading activities are considered for purposes of LSTs since these phases represent the maximum localized emissions that would occur. Any other construction phases of development that overlap would result in less emissions and consequently less impacts than what is disclosed herein. As shown in Table 14, emissions resulting from construction of the proposed Project would not exceed the numerical thresholds of significance established by the SCAQMD for any criteria pollutant. Thus, and consistent with the 4 The purpose of SCAQMD’s Environmental Justice program is to ensure that everyone has the right to equal protection from air pollution and fair access to the decision-making process that works to improve the quality of air within their communities.

Further, the SCAQMD defines Environmental Justice as “…equitable environmental policymaking and enforcement to protect the health of all residents, regardless of age, culture, ethnicity, gender, race, socioeconomic status, or geographic location, from the health effects of air pollution.”

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Figure 8 Sensitive Receptor Locations
(UC, 2024, Exhibit 2)

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Table 14 Project Localized Construction Emissions
On-Site Emissions Emissions (lbs/day)
NOX CO PM10 PM2.5
Demolition
Maximum Daily Emissions 12.29 11.39 0.93 0.52
SCAQMD Localized Threshold 92 508 3 2
Threshold Exceeded? No No No No
Site Preparation
Maximum Daily Emissions 14.19 12.46 2.75 1.61
SCAQMD Localized Threshold 144 841 5 4
Threshold Exceeded? No No No No
Grading
Maximum Daily Emissions 91.70 80.44 10.51 5.82
SCAQMD Localized Threshold 270 1,700 12 8
Threshold Exceeded? No No No No
(UC, 2024, Table 9)
conclusion reached by the SHP EIR, a less-than-significant impact would occur for localized Project-related construction-source emissions and no mitigation is required. (UC, 2024, p. 19) For purposes of disclosure, Table 15, SHP EIR Construction-Related Localized Emissions Summary, provides a summary of the Approved Project’s localized emissions as reported by the SHP EIR. Table 16, Construction-Related Localized Emissions Comparison – SHP EIR vs. Proposed Project, provides a comparison between the proposed Project’s construction-related localized emissions in comparison to what was disclosed for the Approved Project by the SHP EIR. As shown, the proposed Project would result in a slight increase in localized emissions of NOX, CO, and PM10, and would result in reduced localized emissions of PM2.5. The increase in emissions of NOX, CO, and PM10 likely is the result of changes to the CalEEMod emission factors and modeling assumptions, given that there has been no change in the Project’s construction-related characteristics other than a reduction in areas proposed for grading and a reduction in the number of proposed dwelling units. Additionally, the proposed Project’s emissions of NOX, CO, and PM10, and PM2.5 would be below the SCAQMD LSTs for these pollutants, as shown in c)Table 6. On this basis, and consistent with the conclusion reached by the SHP EIR, Project-related construction emissions would not expose sensitive receptors to substantial pollutant concentrations, and the Project’s impacts due to localized emission impacts would be less than significant. (UC, 2024, p. 19) Localized Operational Emissions
According to SCAQMD LST methodology, LSTs would apply to the operational phase of a proposed project if the project includes stationary sources, or attracts mobile sources that may spend long periods queuing and idling at the site (e.g., transfer facilities and warehouse buildings). The proposed project does not include such uses, and thus, due to the lack of significant stationary source emissions, no LST analysis is needed for operations. Although the SHP EIR did include calculations of the Approved Project’s operational localized emissions in comparison to the LSTs, which showed that operational-related localized emissions would be below all of the SCAQMD operational LSTs, because the Project does not include any stationary sources or mobile sources associated with long periods of queuing, an updated analysis of the proposed Project’s operational-related localized impacts is not

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Table 15 SHP EIR Construction-Related Localized Emissions Summary Activity
Onsite Emissions (pounds per day)
NOX CO PM10 PM2.5
Site Preparation 56.89 42.63 0.98 6.71
Grading 79.05 50.84 7.02 4.91
Paving 22.39 14.82 1.26 1.16
Building Construction 26.41 18.13 1.78 1.67
Architectural Coating 1.53 1.82 0.09 0.09
Maximum Daily Emissions a 79.05 50.84 7.02 6.71
Localized Significance Threshold 270 1,700 12 8
Exceed Threshold? No No No No
a
Each of the above activities does not occur at the same time; therefore, the maximum daily emissions represent the maximum emissions that would occur in one day. (Corona, 2015, Table 4.B-8)
Table 16 Construction-Related Localized Emissions Comparison – SHP EIR vs. Proposed Project Source Maximum Daily Localized Emissions (lbs/day)
NOX CO PM10 PM2.5
Proposed Project 91.70 80.44 10.51 5.82
Approved Project 79.05 50.84 7.02 6.71
Net Localized Emissions (Proposed - Approved) +12.65 +29.60 +3.49 -0.89 warranted. Notwithstanding, given that the proposed Project would include 276 single-family residential dwelling units, or 16 fewer dwelling units than the 292 dwelling units evaluated by the SHP EIR, it can be concluded that the proposed Project’s localized operational emissions would be slightly less than the localized emissions associated with the Approved Project. Therefore, and consistent with the conclusion reached by the SHP EIR, Project-related construction emissions would not expose sensitive receptors to substantial pollutant concentrations, and the Project’s impacts due to localized emission impacts would be less than significant. (UC, 2024, p. 19)
CO “Hot Spot” Analysis
As discussed below, the Project would not result in potentially adverse CO concentrations or “hot spots.” An adverse CO concentration, known as a “hot spot”, would occur if an exceedance of the state one-hour standard of 20 parts per million (ppm) or the eight-hour standard of 9 ppm were to occur (UC, 2024, p. 23).

It has long been recognized that CO hotspots are caused by vehicular emissions, primarily when idling at congested intersections. In response, vehicle emissions standards have become increasingly stringent in the last twenty years.

Currently, the allowable CO emissions standard in California is a maximum of 3.4 grams/mile for passenger cars (there are requirements for certain vehicles that are more stringent). With the turnover of older vehicles, introduction of cleaner fuels, and implementation of increasingly sophisticated and efficient emissions control technologies, CO concentration in the SCAB is now designated as attainment. (UC, 2024, p. 23)

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To establish a more accurate record of baseline CO concentrations affecting the SCAB, a CO “hot spot” analysis was conducted in 2003 for four busy intersections in Los Angeles at the peak morning and afternoon time periods5 .

This “hot spot” analysis did not predict any exceedance of the 1-hour (20.0 ppm) or 8-hour (9.0 ppm) CO standards, as shown on Table 10 of the Project’s AQ/GHG Assessment (Technical Appendix C). (UC, 2024, p. 23) Based on the SCAQMD's 2003 AQMP and the 1992 Federal Attainment Plan for Carbon Monoxide (1992 CO Plan), peak carbon monoxide concentrations in the SCAB were a result of unusual meteorological and topographical conditions and not a result of traffic volumes and congestion at a particular intersection. As evidence of this, for example, of the 8.4 ppm 8-hr CO concentration measured at the Long Beach Boulevard and Imperial Highway. intersection (i.e., the highest CO generating intersection within the “hot spot” analysis), only 0.7 ppm was attributable to the traffic volumes and congestion at this intersection; the remaining 7.7 ppm were due to the ambient air measurements at the time the 2003 AQMP was prepared. In contrast, an adverse CO concentration, known as a “hot spot”, would occur if an exceedance of the state one-hour standard of 20 ppm or the eight-hour standard of 9 ppm were to occur. (UC, 2024, pp. 23-24)
The ambient 1-hr and 8-hr CO concentration within the Project study area is estimated to be 1.6 ppm and 1.2 ppm, respectively (data from Metropolitan Riverside County station for 20226 ). Therefore, even if the traffic volumes for
the proposed Project were ten times the traffic volumes generated at the Long Beach Boulevard and Imperial Highway intersection, due to the on-going improvements in ambient air quality and vehicular emissions controls, the Project would not be capable of resulting in a CO “hot spot” at any study area intersections. As noted above, only 0.7 ppm were attributable to the traffic volumes and congestion at one of the busiest intersections in the SCAB. Therefore, if these traffic volumes were multiplied by ten times, it could be expected that the CO attributable to traffic would increase tenfold as well, resulting in 7 ppm – even if this were added to either the 1-hour or 8- hour CO concentrations within the Project study area, this would result in 8.6 ppm and 8.2 ppm for the 1-hr and 8-hr timeframes, respectively, and neither would exceed the applicable 1-hr standard of 20 ppm or the 8-hr standard of 9 ppm. (UC, 2024, p. 24)
Similar considerations are also employed by other Air Districts when evaluating potential CO concentration impacts. More specifically, the Bay Area Air Quality Management District (BAAQMD) concludes that under existing and future vehicle emission rates, a given project would have to increase traffic volumes at a single intersection by more than 44,000 vehicles per hour (vph) – or 24,000 vph where vertical and/or horizontal air does not mix – in order to generate a significant CO impact. Traffic volumes generating the CO concentrations for the “hot spot” analysis are shown on Table 11 of the Project’s AQ/GHG Assessment (Technical Appendix C). The busiest intersection evaluated was that at Wilshire Boulevard and Veteran Avenue, which had AM/PM traffic volumes of 8,062 vph and 7,719 vph respectively. (UC, 2024, p. 24) As shown in Table 12 of the Project’s AQ/GHG Assessment (Technical Appendix C), the highest trips on a segment of road for the proposed Project during AM/PM traffic is 2,848 vph and 3,173 vph, respectively, on Serfas Club Dr. & Green River Road. As such, Project-related traffic volumes are less than the traffic volumes identified in the 2003 AQMP. The Project considered herein would not produce the volume of traffic required to generate a CO “hot 5 The CO “hot spot” analysis conducted in 2003 is the most current study used for CO “hot spot” analysis in the SCAB. 6 It should be noted that the Metropolitan Riverside County monitoring station CO data was utilized in lieu of the Corona/Norco Area monitoring station, as no CO data is available for 2022 at this monitoring station.

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spot” either in the context of the 2003 Los Angeles hot spot study or based on representative BAAQMD CO threshold considerations. Therefore, CO “hot spots” are not an environmental impact of concern for the Project.

Accordingly, and consistent with the findings of the SHP EIR, the Project’s localized air quality impacts related to mobile-source emissions would therefore be less than significant. (UC, 2024, p. 25) Conclusion
As demonstrated in the preceding analysis, the proposed Project’s localized emissions during construction and long-term operation would not exceed any of the SCAQMD LSTs, and the Project would not generate traffic levels that have the potential to cause or contribute to a CO “hot spot.” Therefore, and consistent with the findings of the SHP EIR, the proposed Project would not expose sensitive receptors to substantial pollutant concentrations, and impacts would be less than significant. Accordingly, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.
e) Would the Project create objectionable odors that would affect a substantial number of people? Skyline Heights Project EIR Findings: Less-than-Significant Impact. The SHP EIR found that implementation of the SHP would not create objectionable odors affecting a substantial number of people, and concluded that odors associated with construction and operation of the SHP would be less than significant. (Corona, 2015, pp. 4.B-35 to 4.B-36)
EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. The potential for the Project to generate objectionable odors has also been considered. Land uses generally associated with odor complaints include agricultural uses (livestock and farming), wastewater treatment plants, food processing plants, chemical plants, composting operations, refineries, landfills, dairies, fiberglass molding facilities. Similar to the project evaluated in the SHP EIR, the Project does not contain land uses typically associated with emitting objectionable odors. Potential odor sources associated with the proposed Project may result from construction equipment exhaust and the application of asphalt and architectural coatings during construction activities and the temporary storage of typical solid waste (refuse) associated with the proposed Project’s (long-term operational) uses.

Standard construction requirements would minimize odor impacts from construction. The construction odor emissions would be temporary, short-term, and intermittent in nature and would cease upon completion of the respective phase of construction and is thus considered less than significant. It is expected that Project-generated refuse would be stored in covered containers and removed at regular intervals in compliance with the solid waste regulations. The proposed Project would also be required to comply with SCAQMD Rule 402 to prevent occurrences of public nuisances. Therefore, and consistent with the conclusion reached by the SHP EIR, odors associated with the proposed Project construction and operations would be less than significant and no mitigation is required. Accordingly, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR. (UC, 2024, pp. 25-26)

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f) Would the Project conflict with any applicable plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to, the general plan and municipal code) adopted for the purpose of avoiding or mitigating an environmental effect? Skyline Heights Project EIR Findings: Less-than-Significant Impact. The SHP EIR included an analysis of the Approved Project’s consistency with the City of Corona General Plan, which demonstrated that the Approved Project would not result in a conflict with any applicable plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to, the general plan and municipal code) adopted for the purpose of avoiding or mitigating an environmental effect. As such, the SHP EIR concluded that impacts would be less than significant.

EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. The SHP EIR was certified in 2017.

However, subsequent to certification of the SHP EIR, the City of Corona City Council adopted an update to the City’s General Plan in 2020, with the most recent amendment to the General Plan occurring in April 2024. Table 17, Project Consistency with General Plan Policies Related to Air Quality, provides an analysis of the proposed Project’s consistency with the air quality-related goals and policies from the 2020 General Plan, which are included in the General Plan Open Space and Conservation Element. As indicated in Table 17, the proposed Project would be consistent with or otherwise would not conflict with the General Plan policies related to air quality. Therefore, and consistent with the finding of the SHP EIR, the proposed Project would not conflict with any applicable plan, policy, or regulation of an agency with jurisdiction over the project adopted for the purpose of avoiding or mitigating an environmental effect, and impacts would be less than significant. Accordingly, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.

Table 17 Project Consistency with General Plan Policies Related to Air Quality Goal/Policy Project Consistency
Goal OS-7: Improve air quality and seek to reduce
greenhouse gas emissions.

Consistent. As demonstrated by the analysis presented
herein, the proposed Project would result in less-thansignificant impacts due to air quality and GHG emissions.

Policy OS-7.1: Development Design and Practices. Reduce the amount of air pollution emissions from mobile and
stationary sources, and enhance the South Coast Air Basin by using best management practices in development
proposals and project implementation.

Consistent. As demonstrated by the analysis presented
herein, the proposed Project would result in less-thansignificant impacts due to air quality emissions. In addition, the Project would be subject to compliance with all applicable SCAQMD Rules and regulations, and the
Project would be constructed in conformance with the
incumbent Title 24 regulations that include best
management practices intended to reduce air quality
emissions.

Policy OS-7.2: Public Transportation Pursue expansion of the public transportation system, as well as bicycle and pedestrian trails, that are linked to the regional transit network, to reduce vehicle trips.

Consistent. Public transit is not currently available in the Project area, and the expansion of public transit service in the local area is beyond the scope of the Project evaluated herein. However, proposed trails and trail head
improvements within the Project site would provide
connectivity for hikers and bicyclists to the public park amenities and would allow connections to existing trails.

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Goal/Policy Project Consistency
This connectivity to the existing trails would allow public access to City owned properties and trails and connectivity from Foothill Parkway to the Skyline Ridge Trail.

Policy OS-7.3: Alternative Vehicles Promote the use of fuelefficient and low-emissions vehicles, including neighborhood electric vehicles (NEVs).

Consistent. Policy OS-7.3 provides direction to City staff and decision makers to promote the use of fuel-efficient and low-emissions vehicles, including NEVs, and is not
applicable to the proposed Project. Notwithstanding, the Project would be subject to the incumbent Title 24
regulations. Under the current version of the 2022
California Green Building Standards Code, Title 24, Part 11 (CALGreen), all dwelling units are required to be provided with a complete Electric Vehicle (EV) charging circuit and receptacle. The circuit must be 208/240 volt, 40 amp rated, with an EV charging receptacle and ready to charge EVs.

Mandatory compliance with applicable CALGreen
requirements would serve to promote the use of fuelefficient and low-emissions vehicles, including NEVs.

Policy OS-7.4: Municipal Fleet Manage the municipal fleet to achieve the highest possible number of fuel-efficient and low emissions vehicles commercially available.

Not Applicable. Policy OS-7.3 provides direction to City staff and decision makers related to management of the
municipal fleet, and is not applicable to the proposed
Project.

Policy OS-7.5: Trip Reduction Encourage a mix of housing types that are affordable to all segments of the population and are near job opportunities to further reduce vehicle trips.

Consistent. In conformance with this policy, the Project accommodates a mix of three different housing types,
including 92 single family detached housing units (on 7,200 square foot lots), three custom single-family lots, 104 8- cluster single family detached housing units, and 77 4- cluster single family detached housing units. The clustered dwelling units are intended to be more affordable than
typical single-family uses. In addition, the Project site is located in close proximity to employment opportunities, including a concentration of employment-generating uses located along the northern side of State Route 91 (SR 91), or approximately 2.0 miles north of the Project site, with a variety of other employment opportunities available along the southern side of SR 91.

Policy OS-7.6: Transportation Trip Management Encourage employers to implement transportation demand
management (TDM) measures to reduce trips and vehicle
miles traveled.

Not Applicable. Policy OS-7.6 applies to employmentgenerating land uses, and the proposed Project does not include any such uses. Thus, Policy OS-7.6 is not applicable to the proposed Project.

Policy OS-7.7: Clean Technologies Encourage businesses to use clean, innovative technologies and promote the use of alternative clean-fueled vehicles, new transportation
technologies, and other alternatives to the combustion
engine for City vehicles and individual use.

Not Applicable. Policy OS-7.7 applies to businesses and City-owned vehicles. The proposed Project does not
include any commercial or industrial uses, and the Project would not include any City vehicles. Thus, Policy OS-7.7 is not applicable to the proposed Project.

Policy OS-7.8: Green Building Techniques Encourage green building techniques that improve indoor air quality, energy efficiency and conservation in buildings, and utilization of Consistent. The proposed Project would be constructed in accordance with the incumbent Title 24 regulations, which include a number of provisions, including requirements

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Goal/Policy Project Consistency
renewable energy sources. related to EV charging equipment, that would serve to improve indoor air quality, energy efficiency, and
conservation in the Project’s proposed residential
buildings.

Policy OS-7.9: Stationary Source Pollution Continue to
minimize stationary source pollution through the
following:
• Ensure that industrial and commercial land uses are
meeting existing South Coast Air Quality Management
air thresholds by adhering to established rules and
regulations.
• Encourage the use of new technology to neutralize
harmful criteria pollutants from stationary sources.
• Reduce exposure of the City’s sensitive receptor s to poor air quality nodes through smart land use
decisions.

Not Applicable. The proposed Project consists of a
proposed residential subdivision and would not include
any stationary pollution sources, nor would the Project include any commercial or industrial land uses. Thus,
Policy OS-7.9 is not applicable to the proposed Project.

Policy OS-7.10: Sensitive Receptors Locate sensitive
receptors (i.e., residences, playgrounds, childcare centers, athletic facilities, churches, long-term health care facilities, rehabilitation centers, convalescent centers, and
retirement homes) away from significant pollution sources to the maximum extent feasible.

Consistent. As evaluated herein under Air Quality
Threshold d), the proposed Project would not expose any nearby sensitive receptors to substantial pollutant
concentrations. In addition, the land uses surrounding the Project site are not associated with substantial pollution sources.

Policy OS-7.11: Fugitive Dust Reduce the amount of
fugitive dust released into the atmosphere by construction and demolition, materials handling, paved roads, unpaved roads, and stock piles through development standards and compliance with CEQA regulations.

Consistent. The proposed Project would be required to
comply with SCAQMD Rule 403 for fugitive dust, which
would minimize the amount of fugitive dust that would be generated during the Project’s construction phase.

Policy OS-7.12: Best Management Practices Ensure all
applicable best management practices are used in
accordance with South Coast Air Quality Management
District (SCAQMD) to reduce emitting criteria pollutants during construction.

Consistent. The proposed Project would be subject to
compliance with all applicable SCAQMD best management
practices, rules and regulations, which would serve to
reduce the Project’s level of criteria pollutants during construction. In addition, and as demonstrated herein
under the analysis of Air Quality Thresholds b), c), and d) the Project’s construction-related emissions would be
below the SCAQMD’s Regional thresholds of significance
and also would be below the SCAQMD’s LSTs.

Policy OS-7.13: Partnerships Continue to work with the
WRCOG Regional Air Quality Task Force to implement
regional and local programs designed to meet federal,
state, and regional air quality planning requirements.

Not Applicable. Policy OS-7.13 provides direction to City staff and decision makers to coordinate with other
agencies to implement regional and local programs
designed to meet federal, state, and regional air quality planning requirements, and is not applicable to the
proposed Project.

Policy OS-7.14: Public Education Protect the air from
contamination by working with South Coast Air Quality
Management District and other interested organizations to elevate public awareness regarding air pollution sources and pollutant reduction initiatives.

Not Applicable. Policy OS-7.14 provides direction to City staff and decision makers to work with SCAQMD and other organizations to elevate public awareness regarding air pollution sources and pollutant reduction initiatives, and is not applicable to the proposed Project.

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Goal/Policy Project Consistency
Policy OS-7.15: State Updates Consult and coordinate with State resource and emergency management agencies
regarding updates to climate change science and
development of adaption priorities.

Not Applicable. Policy OS-7.15 provides direction to City staff and decision makers to consult and coordinate with State resource and emergency management agencies
regarding updates to climate change science and
development of adaption priorities, and is not applicable to the proposed Project.

2.4 Biological Resources
New
Significant
Impact
More
Severe
Impacts
New Ability to
Substantially
Reduce Significant
Impact
No Substantial
Change from
Previous
Analysis
Would the Project:
a. Have a substantial adverse effect, either directly or through habitat modifications, on any species
identified as a candidate, sensitive, or special status species in local or regional plans, policies, or
regulations, or by the California Department of Fish
and Game or U.S. Fish and Wildlife Service?
☐ ☐ ☐ ☒
b. Have a substantial adverse effect on any riparian
habitat or other sensitive natural community
identified in local or regional plans, policies,
regulations or by the California Department of Fish
and Game or U.S. Fish and Wildlife Service?
☐ ☐ ☐ ☒
c. Have a substantial adverse effect on federally
protected wetlands as defined by Section 404 of
the Clean Water Act (including, but not limited to,
marsh, vernal pool, coastal, etc.) through direct
removal, filling, hydrological interruption, or other
means?
☐ ☐ ☐ ☒
d. Interfere substantially with the movement of any
native resident or migratory fish or wildlife species
or with established native resident or migratory
wildlife corridors, or impede the use of native
wildlife nursery sites?
☐ ☐ ☐ ☒
e. Conflict with any local policies or ordinances
protecting biological resources, such as a tree
preservation policy or ordinance?
☐ ☐ ☐ ☒
f. Conflict with the provisions of an adopted Habitat
Conservation Plan, Natural Community ☐ ☐ ☐ ☒

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New
Significant
Impact
More
Severe
Impacts
New Ability to
Substantially
Reduce Significant
Impact
No Substantial
Change from
Previous
Analysis
Conservation Plan, or other approved local,
regional, or state habitat conservation plan?

ENVIRONMENTAL ANALYSIS
In order to evaluate the proposed Project’s potential impacts to biological resources, two Project-specific technical studies have been prepared by L&L Environmental, Inc. (herein, “L&L”). The first report provides a general biological resources assessment, is titled, “An Updated Biological Resources Assessment and Crotch Bumble Bee Survey for TTM 36544; Skyline Heights Project, City of Corona, Riverside County, California” (herein, “BRA”), dated November 2024, and included as Technical Appendix D1 (L&L, 2024). The second report addresses the Project’s potential impacts to riparian/riverine resources and the burrowing owl as required by the Western Riverside County Multiple Species Habitat Conservation Plan (MSHCP), is entitled, “Revised Determination of Biologically Equivalent or Superior Preservation Report for TTM 36544, Skyline Heights Project, City of Corona, Riverside County, California” (herein, “DBESP”), is dated January 2025, and is included as Technical Appendix D2 (L&L, 2025). a) Would the Project have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service?
Skyline Heights Project EIR Findings: Less-than-Significant Impact With Mitigation Incorporated. The draft SHP EIR was recirculated in order to address public comments related to impacts to biological resources. The Recirculated SHP EIR (herein, “REIR”) found that five (5) sensitive plant species were observed on the SHP site during the focused plant surveys, including intermediate mariposa lily (IML), paniculate tarplant, chaparral nolina, Fish’s milkwort, and Coulter’s matilija poppy (CMP). Mitigation Measures BIO-MM2, BIO-MM3, and BIO-MM4 were identified in the REIR to ensure that impacts to these species were reduced to a less than significant level.

Three (3) other sensitive plant species were determined by the to have a moderate or high potential of occurrence on the SHP site based on the presence of suitable or potentially suitable habitat, including western spleenwort, Payson’s jewel-flower, and intermediate Mo Nardella. The REIR noted that no occurrences of these three sensitive plant species previously were documented within the SHP site, nor were they observed during focused surveys.

However, the REIR found that their potential presence is not completely eliminated because the species may occur in the chaparral understory. The REIR also disclosed that focused surveys conducted for burrowing owl (BUOW), least Bell’s vireo (LBV), and California gnatcatcher (CAGN) were negative. The REIR imposed Mitigation measures BIO-MM11 and BIO-MM12 to ensure no future impacts would occur to migratory and nesting birds or BUOW, respectively, prior to construction. With the implementation of the proposed mitigation measures, which the REIR found would provide protection to the special-status species if they are found on the SHP site, the REIR concluded that impacts would be reduced to a less than significant level. Mitigation measures also were identified in the REIR to address indirect impacts. (Corona, 2016, pp. 4.C-42 through 4.C-50)

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EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. The following discussion examines the potential impacts to sensitive plants and wildlife that would occur as a result of the proposed Project.

Special-Status Plant Species
Impacts to Observed Plant Species
A total of 278 botanical species were observed on or adjacent to the Project site and off-site improvement areas (herein, “Survey Areas”) during all the biological surveys, including the 2013, 2016, 2017, and 2024 focused botanical surveys. Portions of the site are undisturbed and support native habitats. A list of all observed botanical species is included in Table 12 within Appendix A to the Project’s BRA (Technical Appendix D1). (L&L, 2024, p. 45) Botanical species State and/or federally listed as threatened, endangered, proposed, or candidate species for listing as endangered or threatened were evaluated as part of the Project’s BRA. A description of these species and their potential for occurrence is summarized in Table 14 within Appendix A to the Project’s BRA (Technical Appendix D1). These species were either documented by the California Natural Diversity Database (CNDDB) or California Native Plant Society (CNPS) as occurring within the same quadrangle as the survey area or adjacent quadrangles, addressed in previous reports, or were identified by the United States Fish and Wildlife Service (USFWS), U.S. Forest Service (USFS), or other agency as potentially occurring in the area. (L&L, 2024, p. 47) The Survey Area was evaluated for potential presence or absence of suitable habitat to support State- and/or federally-listed plant species. Braunton’s milk-vetch, Munz’s onion, San Diego ambrosia, slender-horned spineflower, Santa Ana River woollystar, and thread-leaved brodiaea were determined to have potentially suitable habitat in the Survey Area. These species were not observed during surveys in 2013, 2016, 2017 or 2024 and have low probability of occurrence in the survey area. As such, no impacts to federal or State-listed plants are anticipated and no mitigation is required. (L&L, 2024, p. 99) Six (6) special-status species, intermediate mariposa lily (IML), paniculate tarplant, chaparral nolina, Fish’s milkwort, Coulter’s matilija poppy (CMP), and Brewer’s calandrinia, were observed in the Survey Area during L&L’s focused surveys. Three (3) other special status-species have suitable or potentially suitable habitat in the Survey Area and the species were determined to have moderate or high potential of occurrence: western spleenwort, intermediate monardella, and San Diego County viguiera. No occurrences of these additional plants previously were documented within the Survey Area, nor were they observed during the current surveys, but the species may occur in inaccessible areas. (L&L, 2024, p. 99)
The California Rare Plant Rank (CRPR) was used to evaluate the significance of impacts for special-status plants.

The CNPS, in coordination with the California Department of Fish and Wildlife (CDFW), has cataloged California's rare and endangered plants into lists according to population distributions and viability. These lists are numbered and indicate the following CRPRs: (1A) presumed extinct in California; (1B) rare, threatened, or endangered throughout their range; (2A) presumed extirpated in California, but more common in other states; (2B) threatened or endangered in California, but more common in other states; (3) more information is needed to establish rarity; and (4) plants of limited distribution in California (i.e., naturally rare in the wild), but whose populations do not appear to be susceptible to threat. A CRPR may also have an extension (e.g., 1B.x) that indicates current level of threat: seriously threatened (x.1), moderately threatened (x.2), or not very threatened (x.3). (L&L, 2024, p. 99)

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The design of the proposed Project would impact 18 of the 30 (60 percent) observed Fish’s milkwort, all 342 (100 percent) paniculate tarplant, the one (100 percent) Brewer’s calandrinia, 463 of the 676 (71 percent) observed intermediate mariposa lily (IML), 316 of the 716 (44 percent) Coulter’s matilija poppy (CMP), and ±2,180 of the estimated 5,343 (41 percent) chaparral nolina based on the number of individuals recorded on site (refer to Table 16 in Appendix A to the Project’s BRA, included as Technical Appendix D1). (L&L, 2024, p. 100) IML, Fish’s milkwort, and CMP are covered species under the MSHCP and adequately conserved under the Plan.

The MSHCP does not require surveys or mitigation for these species. Accordingly, Project-related impacts to IML, Fish’s milkwort, and CMP are a covered impact under the MSHCP, and impacts to these species would be less than significant with mandatory compliance with the MSHCP and payment of the MSHCP Mitigation Fee as required pursuant to Corona Municipal Code (CMC) Section 16.33.070. (L&L, 2024, p. 100) Brewer’s calandrinia has a CRPR rank of 4.2 and is not a covered species under the MSHCP. This species has a wide range in California from Sacramento south, largely near the coast, continuing all the way to Mexico. Calflora identifies 47 records within the Santa Ana Mountains, and all but one are located within Public/Quasi-Public (PQP) conserved lands. Impacts to a single Brewer’s calandrinia represents an adverse but less-than-significant impact requiring no mitigation. (L&L, 2024, p. 100)
Paniculate tarplant has a CRPR rank of 4.2 and is not a covered species under the MSHCP. This species has a wide range in southern California from San Luis Obispo south through Orange and Riverside County and continuing into San Diego County. Calflora identifies over 317 records within western Riverside County. Numerous populations are located within PQP and Western Riverside County Regional Conservation Authority (RCA) conserved lands. Projectrelated impacts would not substantially affect regional populations of paniculate tarplant. Additionally, although this species is not covered under the MSHCP, the conservation lands that comprise the MSHCP reserve assembly include habitat suitable to support this species. Therefore, any potential impact would be addressed through Project consistency with the MSHCP, as suitable habitat for these species has been conserved on a regional level.

Based on the wide distribution, number of locations within western Riverside County, and known locations of this species within MSHCP conservation areas, impacts to paniculate tarplant would be adverse but less than significant and no additional mitigation is required. (L&L, 2024, pp. 100-101) Chaparral nolina has a CRPR rank of 1B.2 (plants rare, threatened, or endangered in California and elsewhere, moderately threatened in California) and is not covered under the MSHCP. Chaparral nolina is recorded over a wide area in the coastal mountains from Ventura County south through San Diego County. The majority of populations are recorded in the Cleveland National Forest and/or on the western slopes of the Santa Ana Mountains. Often these populations include numerous individuals. Half of the CNDDB records document populations over 50 individuals or identify the population as common or abundant. Thirteen (13) populations are between 100 and 900 plants, six (6) populations are over 1000 plants, and one (1) is recorded as over 10,000. The Santa Ana Mountains appear to support the largest population of chaparral nolina and, according to the CNPS, the principal populations of this species are found in the northern Santa Ana Mountains. Chaparral nolina is, however, represented by few occurrences within Riverside County, having only two (2) recorded populations in the CNDDB.

The population within the survey area is estimated at ±5,343 plants. Impacts to chaparral nolina are estimated based on acres impacted for the three (3) largest populations. The chaparral nolina population south of the 10- acre USFS Parcel (NAP) is not proposed for impact. Due to the rarity of this species in Riverside County, impacts

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would be considered significant and mitigation measures are proposed to avoid and minimize impacts to chaparral nolina. (L&L, 2024, p. 101)
REIR Mitigation Measure BIO-2 (as modified/supplemented herein) requires preparation of a Chaparral Nolina Planting Plan and collection of nolina seed from the Project site with propagation to an onsite or offsite preserved property. SHP EIR Mitigation Measure BIO-3 requires the conservation in perpetuity of an area that supports approximately ±1,396 chaparral nolina. SHP EIR Mitigation Measure BIO-4 requires the preservation of an area that supports ±1,767 chaparral nolina and further requires that this area be deed restricted so as to prevent future development or disturbance. In total, an estimated 3,163 chaparral nolina would be conserved, preserving the largest recorded population in Riverside County. Implementation of the required mitigation would reduce Project impacts to chaparral nolina to less-than-significant levels. (L&L, 2024, p. 101) Impacts to Plant Species Not Observed but with the Potential to Occur Special status plants western spleenwort, intermediate monardella, and San Diego County viguiera have not been observed during surveys but have a moderate potential to occur in the survey area. If present, these species may be impacted by the proposed Project. (L&L, 2024, p. 101) Western spleenwort is distributed over the foothills and mountains of southern California in Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura Counties into Baja California, Mexico. Calflora records 21 locations within the Cleveland National Forest. There are also several locations within western Riverside County, Santa Ana Mountains, and MSHCP identified PQP lands. Although this species is not covered under the MSHCP, the conservation lands that comprise the MSHCP reserve assembly include habitat suitable to support this species.

Therefore, any potential impact would be addressed through consistency with the MSHCP, as suitable habitat for this species has been conserved on a regional level. If western spleenwort is present, impacts would be adverse but not significant and no additional mitigation is required. (L&L, 2024, p. 102) Intermediate monardella is restricted to the Santa Ana and Palomar Mountains. It is recorded in 38 locations spread throughout the Santa Ana Mountains and into the adjacent foothills in Orange, Riverside, and San Diego Counties. There are also a few records from the northwestern foothills of the Palomar Mountains. Nineteen (19) of the 38 records are located within the Cleveland National Forest, three (3) are within parks or preserves, and two (2) are on tribal lands. Although this species is not covered under the MSHCP, the conservation lands that comprise the MSHCP reserve assembly include habitat suitable to support this species. Therefore, any potential impact would be addressed through consistency with the MSHCP, as suitable habitat for this species has been conserved on a regional level. If intermediate monardella is present, impacts would be adverse but not significant and no additional mitigation is required. (L&L, 2024, p. 102)
San Diego County viguiera is identified as locally common in southern San Diego County but shows limited records north of San Diego County. Calflora shows only two recorded observations in the Santa Ana Mountains north of Ortega Highway, with one located in the Cleveland National Forest (CNF). The closest record is approximately 7.2 miles southwest, in Santiago Canyon. The CNPS indicates that all occurrences outside of San Diego County are introduced. If this species is present on the site, individuals may be impacted but the natural distribution of the species would not be affected. Impacts would be less than significant, and no additional mitigation is required. (L&L, 2024, p. 102)

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Indirect Impacts to Sensitive Plant Species
Indirect impacts to special status botanical species in the immediate Project vicinity would result from long-term “edge effects.” A potential increase in non-native species over time, which could impact native plant species, could occur along the Project margins where newly exposed soils, not developed or landscaped, could provide fertile ground. Invasive species occur within the impact area and could, therefore, disperse seed to newly turned soil.

Invasive and noxious weed species seed could be spread or introduced into the area by vehicles or machinery. SHP EIR Mitigation Measure BIO-MM5 requires the preparation of landscape plans that exclude the use of certain plant species in site landscaping, including White Cloud matilija poppy, and further requires the recordation of CC&Rs prohibiting the planting of invasive plant species. SHP EIR Mitigation Measure BIO-MM15, which has been modified as part of this Addendum No. 1 to the SHP EIR, required the preparation and distribution to new home owners an education package informing future residents regarding prohibited plant species. SHP EIR Mitigation Measures BIO-MM16 and BIO-MM17 address potential construction-related impacts due to invasive species that may occur as a result of heavy construction equipment or due to the proximity of proposed construction staging areas. (L&L, 2024, pp. 98-99)
Human and pet encroachment into surrounding habitat areas supporting sensitive plant species may increase over time due to its proximity to increased occupied residential units and recreational use of the natural environment, including Off-Road Vehicle (ORV) and pedestrian uses. Encroachment would be reduced by the incorporation of barriers between avoided areas and development in the Project design, signage requesting that people remain on the existing trails, and Homeowner education materials. SHP Mitigation Measure BIO-MM20, which has been modified as part of this Addendum No. 1 to the SHP EIR, requires the incorporation of measures that address the MSHCP Urban/Wildlands Interface Guidelines (UWIG) requirements. Compliance with SHP EIR Mitigation Measure BIO-20 (as modified herein) would ensure that indirect impacts affecting the conservation areas are reduced to less-than-significant levels. (L&L, 2024, p. 99) Changes that would occur within impacted areas of the unnamed blueline stream located in the middle of the Survey Area (and identified herein as “Feature 3”) could cause downstream impacts and would require special design features to reduce changes to the flood regime. Post-development changes to flooding and water flow through the drainage and its alluvial terraces could negatively impact downstream habitat and individual species, such as Coulter’s matilija poppy. Design features would be required to ensure post-development flow volume and energy levels are consistent with pre-Project levels to prevent impacts to avoided resources. In addition, cultivated and hybrid breeds of matilija poppy can change the wild populations of Coulter’s matilija poppy with an influx of the gene material from these cultivars. Implementation of SHP EIR Mitigation Measures BIO-MM5 and BIO-MM15 and new Mitigation Measure BIO-MM20 would reduce the Project’s potential indirect impacts to Coulter’s matilija poppy to below a level of significance. Implementation of SHP EIR Mitigation Measure BIO-MM5 (as modified herein) would ensure that the Project’s landscape plans do not include any common cultivar forms of Coulter’s matilija in the plant palette, and further would ensure that the landscaping plant palette excludes those plant species identified by MSHCP Table 6-2, Plants that Should be Avoided Adjacent to the MSHCP Conservation Area.

SHP EIR Mitigation Measure BIO-MM15 (as modified herein) requires the Project Applicant to prepare and provide to future homeowners an education package informing future tenants/homeowners of the list of prohibited plant species identified by Mitigation Measure BIO-MM5. Implementation of New Mitigation Measure BIO-MM20 would ensure that the Project’s Codes, Covenants, and Restrictions (CC&Rs) include a provision prohibiting the

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planting of any of the plant species identified by Mitigation Measure BIO-5, which would help ensure that such plant species are not planted by future homeowners/tenants. Implementation of the required mitigation would reduce the Project’s indirect impacts to sensitive plant species to below a level of significance. (L&L, 2024, pp. 102- 103)
Special-Status Wildlife Species
Direct Impacts to Special-Status Wildlife Species
Mountain lion and Crotch’s bumble bee, both candidates for State listing, were observed in the Survey Area. No other listed wildlife was detected in the Survey Area. Three (3) listed or fully protected wildlife species (golden eagle, Coastal California Gnatcatcher [CAGN], and Quino Checkerspot Butterfly [QCB]) have been determined to have a high or moderate potential for occurrence in the Survey Area. Focused coastal California gnatcatcher surveys conducted in 2013 were negative. (L&L, 2024, p. 103) Habitat potentially suitable to support Stephen’s kangaroo rat (SKR) is present in the Survey Area. The Project site is not within the boundaries of the Stephens’ Kangaroo Rat Habitat Conservation Plan (SKR HCP). The MSHCP covers impacts to Stephens’ kangaroo rat because the Project site is located within the MSHCP boundaries but is located outside of the boundaries of the SKR HCP. Stephens’ kangaroo rat is a covered species under the MSHCP and adequately conserved under the Plan. Project-related impacts (if any) to Stephens’ kangaroo rat would be a covered impact under the MSHCP and would therefore be less than significant, with no mitigation required. (L&L, 2024, p. 103)
Ten (10) special-status wildlife species were observed or detected during biological surveys: coastal whiptail, orange-throated whiptail, red-diamond rattlesnake, Cooper’s hawk, southern California rufous-crowned sparrow, Vaux’s swift, black-chinned sparrow, California horned lark, Lawrence’s goldfinch, and San Diego black-tailed jackrabbit. (L&L, 2024, p. 103)
Thirteen (13) other special-status wildlife species were not observed during surveys but have a high or moderate potential for occurrence in the survey area: American bumble bee, southern California legless lizard, California glossy snake, San Bernardino ringneck snake, California mountain kingsnake, coast horned lizard, coast patchnosed snake, Bell’s sage sparrow, oak titmouse, pallid bat, Dulzura pocket mouse, hoary bat, and San Diego desert woodrat. (L&L, 2024, p. 103)
Two (2) USFS Management Indicator Species (mountain lion and song sparrow) were observed and one (1) was determined to have a high potential to occur (mule deer). (L&L, 2024, p. 103) Crotch’s bumble bee was observed during focused surveys in 2024 and could be impacted by loss of individuals or colonies. At the time The SHP EIR was certified in 2017, the Crotch’s bumble bee was not listed as endangered or threatened; however, the Crotch’s bumble bee has since been listed as a candidate for State listing as an endangered species. The Crotch's bumble bee is not a covered species under the MSHCP. In the event the Crotch bumble bee is listed as endangered or threatened by the CDFW, Project impacts to this species would be potentially significant. New Mitigation Measure BIO-MM21 has been imposed on the Project and would apply in the event that the Crotch’s bumble bee ultimately is listed as endangered or threatened. The mitigation prohibits clearing/ground disturbing activities from February 1 through September 30 within suitable habitat. For

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construction between October 1 and January 31, Mitigation Measure BIO-MM21 requires a pre-construction survey within suitable habitat to confirm that no nests occur on site. Should any nests be identified, the mitigation requires the Project biologist to consult with CDFW to determine if a permit is required. In addition, Best Management Practices (BMP) measures during construction would be employed to prohibit the use of pesticides considered to be harmful to the Crotch bumble bee. SHP EIR Mitigation Measure BIO-MM4 also requires the conservation of the unimpacted portions of the Survey Area to preclude potential impacts to Crotch bumble bee habitat within the planned open space area on site. Impacts to Crotch bumble bee would be less than significant with implementation of proposed mitigation. (L&L, 2024, p. 104) Mountain lion was detected on the Project site during surveys. Mountain lion is a covered species under the MSHCP and adequately conserved under the Plan. The MSHCP does not require surveys or mitigation for this species. Implementation of SHP EIR Mitigation Measure BIO-13 (as modified herein) would further ensure that human-lion interactions are minimized and avoided. Regardless, any Project-related impacts to mountain lion are a covered impact under the MSHCP; thus, impacts to the mountain lion would be less than significant and no additional mitigation is required. (L&L, 2024, p. 104)
CAGN, QCB, and golden eagle were not observed during surveys but have high or moderate potential for occurrence within the Survey Area. These species are covered under the MSHCP and adequately conserved under the Plan. The MSHCP does not require surveys or mitigation for these species (since the Project site is not within Criteria Cells, restrictions on vegetation clearing during the CAGN nesting season do not apply). Project-related impacts to these species, if any, are a covered impact under the MSHCP and therefore Project impacts to these species would be less than significant. (L&L, 2024, p. 104) Of the remaining special-status species that occur or potentially occur in the Survey Area, the following are covered under the MSHCP and adequately conserved under the Plan: orange throated whiptail, coastal whiptail, reddiamond rattlesnake, coast horned lizard, California horned lark, Cooper’s hawk, southern California rufouscrowned sparrow, Bell’s sage sparrow, San Diego desert woodrat, and San Diego black-tailed jackrabbit. The MSHCP does not require surveys or mitigation for these species. Project-related impacts to these species are a covered impact under the MSHCP and thus would be less than significant. (L&L, 2024, p. 104) Although Project impacts to CAGN, QCB, golden eagle, orange throated whiptail, coastal whiptail, California horned lark, Cooper’s hawk, southern California rufous-crowned sparrow, and Bell’s sage sparrow would be less than significant because these species are considered adequately conserved under the MSHCP, the MSHCP does not provide take authorization for nesting birds. The Project has the potential to result in impacts to these species if construction activities were to occur during the critical nesting period (January 1 through September 1). SHP EIR Mitigation Measure BIO-MM11 (as supplemented/modified herein) would apply, which requires pre-construction surveys and avoidance of any active nests during the breeding season. Implementation of the revised SHP EIR Mitigation Measure BIO-MM11 would reduce the Project’s potential impacts to nesting birds, including nesting CAGN, QCB, golden eagle, orange throated whiptail, coastal whiptail, California horned lark, Cooper’s hawk, southern California rufous-crowned sparrow, and Bell’s sage sparrow individuals, to below a level of significance.

In addition, the Project site is located in the MSHCP required survey area for the Burrowing Owl (BUOW). No BUOW or BUOW sign was observed in the survey area during the 2013 focused survey nor any of the other subsequent biological field surveys. Supplemental habitat assessments and burrow surveys were performed in 2016 and 2024.

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No BUOW, BUOW sign or suitable burrows were observed in the Survey Area. This species is migratory and has potential to relocate to the Project site. Potentially suitable habitat for BUOW is present on the site and the MSHCP requires a protocol survey for all projects located within the MSHCP Burrowing Owl Survey Area. However, the Project would be subject to compliance with SHP EIR Mitigation Measure BIO-12 (as revised/supplemented herein), which requires a 30-day preconstruction survey for BUOW to be conducted to prevent impacts to the species and details actions to be taken if BUOW are observed. Impacts would be less than significant with implementation of the required mitigation. (L&L, 2024, p. 105) The remaining species with a potential to occur on site are not covered under the MSHCP. This includes American bumble bee, southern California legless lizard, California glossy snake, San Bernardino ringneck snake, coast patchnosed snake, oak titmouse, Vaux’s swift, Lawrence’s goldfinch, black-chinned sparrow, pallid bat, Dulzura pocket mouse, and hoary bat. The California mountain kingsnake is covered under the MSHCP but is not adequately conserved. In evaluating the rarity of these species, the CNDDB ranks species from S1 to S5 and 0.1-0.3 with the rarest as S1.1 and most common as S5. The definitions of these rankings identify S4 and S5 as secure in California and S3 as vulnerable, but not currently rare. Species ranked S4 and S5 typically exhibit relatively widespread distribution and species ranked S3 have not reached a level of threat and numbers or populations have not declined to a point that would cause them to be considered “rare”. S3 species are either uncommon or require more data to monitor their status. These species utilize a wide variety of habitats with specialized, but generally available, microhabitats (moisture, loose soil nectar plants). The wide range and diversity of habitats utilized indicates the development of the proposed Project would not substantially decrease available habitat or reduce regional populations for these species. Large tracts of suitable habitat would remain adjacent to and in the Project vicinity, including ±97.6 acres of avoided habitats. Although these species are not covered under the MSHCP, the conservation lands that comprise the MSHCP reserve assembly include habitat suitable to support these species.

Therefore, any potential impact would be addressed through consistency with the MSHCP, as suitable habitat for these species has been conserved on a regional level. Project-related impacts to these species are not expected to appreciably affect overall population or range. Impacts would be considered adverse, but not significant and no additional mitigation is required. (L&L, 2024, p. 105)
Loss of foraging habitat for wildlife species would add to cumulative regional loss of habitat for these species. This is considered an adverse, but less-than-significant impact because of extensive foraging habitat available in the Project vicinity. (L&L, 2024, p. 106)
In addition to the mitigation measures described above, the Project also would be subject to several additional mitigation measures to further avoid and minimize potential impacts to special-status wildlife species that may be present. SHP EIR Mitigation Measure BIO-MM1 (which has been modified/supplemented as part of this Addendum No. 1 to the SHP EIR) includes measures to preclude potential encroachment into preserved areas on site during construction, including a requirement to delineate the conservation areas with flagging/fencing to prevent inadvertent impacts to these areas. The revised SHP EIR Mitigation Measure BIO-MM1 further requires biological monitoring during construction activities. SHP EIR Mitigation Measure BIO-MM3 obligates the Project Applicant to conserve a minimum 10-acre parcel composed of natural habitat adjacent to USFS land. SHP EIR Mitigation Measure BIO-MM4 (as modified herein) the permanent conservation of planned open space areas on site through deed restrictions or conservation easements, including areas containing Riparian/Riverine areas that have been avoided by the design of the proposed Project. Implementation of SHP EIR Mitigation Measures BIOMM1, BIO-MM3, and BIO-MM4 (as modified herein) would ensure that future landscaping on site does not result

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in the introduction of invasive species into the conserved habitat areas on site. In addition, SHP EIR Mitigation Measures BIO-MM1, BIO-MM4, BIO-MM16 through BIO-MM19 (as modified/supplemented herein) impose construction-related requirements to preclude indirect construction-related impacts to the on-site conservation areas. New Mitigation Measure BIO-22 requires the implementation of a Workers Environmental Awareness Program (WEAP) training, which would ensure that construction contractors and employees are fully educated regarding biological habitats and the need to avoid such areas. Implementation of the required mitigation would reduce indirect impacts to sensitive wildlife species to below a level of significance.

Indirect Impacts to Special-Status Wildlife Species
Habitat fragmentation would consist of the permanent loss of ±157.1 acres and temporary loss of 1.7 acres of habitats and isolation of habitats east of the Project from the larger Core B habitat area. The Project would incorporate barriers to prevent both common and special status wildlife species from entering the residential development, thereby decreasing the potential for impact by humans, vehicles, pets, or other urban hazards. The barriers also would prevent human and pet encroachment and reduce potential for direct impacts by those means.

These preventative measures, while incorporated for the safety of wildlife and adjacent habitat, also would restrict wildlife movement and add to habitat fragmentation. Movement restriction and habitat fragmentation can be especially important for large mammals, like the mountain lion population. The proposed Project would not remove movement corridors but would reduce the overall habitat and further constrict the available range habitat for this species. Impacts to mountain lions are addressed above. Management of “edge effects” pursuant to the MSHCP UWIG (as required by SHP EIR Mitigation Measure BIO-20, which has been modified herein) would reduce indirect impacts to all wildlife species, including mountain lions, and would ensure indirect impacts to this species remain below a level of significance. (L&L, 2024, p. 106) Amphibian, reptile, avian, mammal, and insect species may experience impacts from construction, including increases in noise, chemical emissions, and vibration, resulting in avoidance and abandonment of the area.

Movement of species could concentrate populations, increase competition for resources in adjacent habitats, and leave displaced individuals vulnerable to predation. Those species that may use the Project area for foraging still would have access to large expanses of relatively undisturbed habitat in the Project vicinity, including Cleveland National Forest lands to the west. In addition, the MSHCP considers development throughout western Riverside County and balances development with conservation of contiguous blocks of native habitats. The MSHCP determined the survey area is not a Conservation Area or Criteria Area. (L&L, 2024, p. 106) After completion of construction, noise levels adjacent to the site would be increased over current conditions but would not exceed residential noise standards. In addition, barriers are proposed between residential development and conservation areas, which would reduce the amount of noise, chemical emissions, and fugitive dust from the development crossing into or affecting wildlife in the conservation areas after completion of construction. As such, impacts would be less than significant. (L&L, 2024, p. 107) A potential increase in invasive species could occur along the perimeter of the impact area, where newly exposed soils could provide fertile ground. Invasive species that may occur along the current roadway and within the impact area could disperse seed to newly turned soil. SHP Mitigation Measures BIO-MM5 and BIO-MM15 through BIOMM17 would apply (as modified/supplemented herein), along with new Mitigation Measure BIO-MM22.

Mitigation Measure BIO-5 imposes requirements to ensure that invasive plant species are excluded from

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landscaped areas on site, while SHP EIR Mitigation Measures BIO-MM16 through BIO-MM19 impose requirements on heavy equipment, storage areas, refuse, and vehicle speeds to further prevent the potential for invasive plant species. Implementation of the SHP EIR mitigation measures (as modified/supplemented herein) would ensure that the Project’s indirect impacts to sensitive wildlife species would be less than significant. (L&L, 2024, p. 106) Conclusion
With implementation of the biological mitigation measures identified by the SHP EIR (as modified/supplemented herein), Project direct and indirect impacts to special-status plant and wildlife species would be reduced to lessthan-significant levels. It also bears noting that the Project would disturb essentially the same area as identified for disturbance by the SHP EIR, and in fact, result in less total disturbance in comparison to the Approved Project.

Thus, as a general matter, the SHP EIR already anticipated and analyzed all of the impacts to biological resources that would occur from the currently proposed Project. For all these reasons, the proposed Project would not result in any new impact not already analyzed in the SHP EIR or increase the severity of a significant impact previously identified and analyzed in the SHP EIR.
b) Would the Project have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the California Department of Fish and Game or U.S. Fish and Wildlife Service?
Skyline Heights Project EIR Findings: Less-than-Significant Impact With Mitigation Incorporated. The REIR found that implementation of the SHP project would result in significant impacts to three riparian habitat alliances and a sensitive natural sage scrub community. However, the REIR found that implementation of mitigation measures BIO-MM6 through BIO-MM10 would reduce potentially significant impacts to a less-than-significant level. (Corona, 2016, pp. 4.C-50 through 4.C-55)
EIR Addendum No. 1 Finding: No Substantial Change from Previous Analysis. Under existing conditions, three (3) general vegetation types currently exist in the immediate vicinity of the Survey Area: riparian/woodland, upland, and unvegetated/altered. These vegetation types include multiple plant communities that make up the landscape of the survey area (as summarized in Table 5 and depicted on Figures 6, 6a, and 6b of the Project’s BRA, included as Technical Appendix D1). Non-native ornamental species (eucalyptus and pepper trees) are located adjacent to urban areas. The majority of the Survey Area is undisturbed and consists of a variety of chaparral habitats on the north-facing slopes and coastal sage scrub habitats on the dry south facing slopes. Needle grass grasslands are present in previously cleared areas on the ridgelines. Grasslands occur throughout the survey area and primarily are composed of non-native species including bromes (Bromus species), short-pod mustard (Hirschfeldia incana), filaree (Erodium species), and Russian thistle (Salsola tragus), and native species such as doveweed (Croton setigerus) and deerweed (Acmispon glaber). There is a concentration south of the offsite flood control basin at the eastern end of Mabey Canyon Wash. (L&L, 2024, p. 27)
Of the vegetation communities found in the Survey Area, eight (8) are considered sensitive: foothill needle grass grassland, purple needle grass grassland, scale broom scrub (SBS), California sycamore woodlands, California brittle bush scrub, bush penstemon scrub, Eastwood manzanita chaparral, and toyon chaparral (L&L, 2024, p. 44).

In addition, L&L found six (6) main jurisdictional ephemeral drainage features with 56 tributaries, for a total of 62 drainage features. Vegetation in and adjacent to jurisdictional features includes coastal live oak woodland,