Sunnyvale City Council
March 24, 2026

De Guigne Drive Residential Project
Prepared for:

City of Sunnyvale
Community Development Department, Planning Division
January 2026
Attachment 6

De Guigne Drive Residential Project
Prepared for:

City of Sunnyvale
Community Development Department,
Planning Division
456 W. Olive Avenue
Sunnyvale, California 94086
Contact:

Momoko Ishijima
Senior Planner
408.730.7532
Prepared by:

Ascent
455 Capitol Mall, Suite 300
Sacramento, CA 95814
Contact:

Pat Angell
Principal
916.732.3324
January 2026
20250189.01
Attachment 6

City of Sunnyvale
De Guigne Drive Residential Project Environmental Review i

TABLE OF CONTENTS
Section Page
LIST OF ABBREVIATIONS ................................ ................................ ................................ ................................ ................................ .......... III 1 INTRODUCTION ................................ ................................ ................................ ................................ ................................ ........ 1-1

1.1 Purpose of the Environmental Checklist ....................................................................................................................1-1

1.2 Land Use and Transportation Element Update and Project overview .............................................................1-1 2 PROJECT DESCRIPTION ................................ ................................ ................................ ................................ ........................... 2-1

2.1 Project Overview ................................................................................................................................................................ 2-1

2.2 Project Location ................................................................................................................................................................. 2-1

2.3 Existing Setting ................................................................................................................................................................... 2-1

2.4 Project Objectives .............................................................................................................................................................. 2-1

2.5 Project Description ........................................................................................................................................................... 2-4

2.6 Construction ..................................................................................................................................................................... 2-25

2.7 Required Actions ............................................................................................................................................................ 2-25 3 INTRODUCTION TO THE ENVIRONMENTAL CHECKLIST ................................ ................................ ............................... 3-1

3.1 Explanation of Checklist Evaluation Categories ...................................................................................................... 3-1

3.2 Discussion and Mitigation Sections ........................................................................................................................... 3-2 4 ENVIRONMENTAL CHECKLIST................................ ................................ ................................ ................................ .............. 4-1

4.1 Aesthetics ............................................................................................................................................................................. 4-1

4.2 Agriculture and Forest Resources ............................................................................................................................... 4-4

4.3 Air Quality ........................................................................................................................................................................... 4-5

4.4 Biological Resources ...................................................................................................................................................... 4-15

4.5 Cultural Resources ......................................................................................................................................................... 4-19

4.6 Energy................................................................................................................................................................................. 4-21

4.7 Geology and Soils ......................................................................................................................................................... 4-24

4.8 Greenhouse Gas Emissions ......................................................................................................................................... 4-29

4.9 Hazards and Hazardous Materials .......................................................................................................................... 4-34

4.10 Hydrology and Water Quality ................................................................................................................................... 4-40

4.11 Land Use and Planning ................................................................................................................................................ 4-45

4.12 Mineral Resources .......................................................................................................................................................... 4-47

4.13 Noise .................................................................................................................................................................................. 4-48

4.14 Population and Housing .............................................................................................................................................. 4-52

4.15 Public Services ................................................................................................................................................................ 4-54

4.16 Recreation ......................................................................................................................................................................... 4-57

4.17 Transportation/Traffic ................................................................................................................................................... 4-59

4.18 Tribal Cultural Resources ............................................................................................................................................ 4-64

4.19 Utilities and Service Systems ...................................................................................................................................... 4-66

4.20 Wildfire ............................................................................................................................................................................... 4-71

4.21 Mandatory Findings of Significance ......................................................................................................................... 4-73 5 LIST OF PREPARERS ................................ ................................ ................................ ................................ ................................ ..5-1 6 REFERENCES ................................ ................................ ................................ ................................ ................................ ............... 6-1

Attachment 6

Table of Contents Ascent
City of Sunnyvale
ii De Guigne Drive Residential Project Environmental Review Figures
Figure 2-1 Regional Location ............................................................................................................................................................. 2-2 Figure 2-2 Project Site .......................................................................................................................................................................... 2-3 Figure 2-3 Site Plan ............................................................................................................................................................................... 2-5 Figure 2-4a Design Rendering 1 – Looking Northeast from the Intersection of De Guigne Drive and Stewart Drive. ................................................................................................................................................................................................ 2-7 Figure 2-4b Design Rendering 2 – Looking Northwest from Stewart Drive ........................................................................ 2-9 Figure 2-4c Design Rendering 3 – Looking Southwest from De Guigne Drive ................................................................. 2-11 Figure 2-5a Building Elevations – Alley Homes ........................................................................................................................... 2-13 Figure 2-5b Building Elevations – Court Homes .......................................................................................................................... 2-15 Figure 2-5c Building Elevations – Attached Row Townhomes ............................................................................................... 2-17 Figure 2-5d Building Elevations – Attached Interlocking Townhomes ................................................................................ 2-19 Figure 2-6 Circulation Plan ............................................................................................................................................................... 2-21 Figure 2-7 Landscape Plan .............................................................................................................................................................. 2-23

Tables
Table 4.3-1 Attainment Status Designations for Santa Clara County .................................................................................... 4-7 Table 4.3-2 Summary of Annual and Average Daily Exhaust Emissions of Criteria Air Pollutants and Precursors Associated with Project Construction ........................................................................................................................ 4-9 Table 4.3-3 Summary of Annual and Average Daily Exhaust Emissions of Criteria Air Pollutants and Precursors Associated with Project Operation ........................................................................................................................... 4-10

Table 4.3-4 Estimated Health Risks and Hazards during Project Construction – Unmitigated ................................... 4-11 Table 4.3-5 Estimated Health Risks and Hazards during Project Construction –Mitigated .......................................... 4-11 Table 4.3-6 Summary of Cumulative Health Impacts at the Off-site MEI .......................................................................... 4-12 Table 4.3-7 Summary of the Cumulative Health Impacts at the Proposed Project Site during Project Operations ..... 4-12 Table 4.6-1 Project Consistent with the City of Sunnyvale Climate Action Playbook Update/Game Plan 2028 . 4-22

Attachment 6

Ascent List of Abbreviations
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review iii

LIST OF ABBREVIATIONS
µg/m³ micrograms per cubic meter
2-DCE 2-dichloriethylene
AB Assembly Bill
ACC II Advanced Clean Cars II
ACE Altamont Corridor Express
ADU accessory dwelling unit
AFY acre-feet per year
BAAD Bay Area Air District
BAAQMD Bay Area Air Quality Management District (now Bay Area Air District) BMP best management practice
BRA Biological Resources Assessment
CAAQS California Ambient Air Quality Standards
CAFE Corporate Average Fuel Economy
CARB California Air Resources Board
CBC California Building Code
CEQA California Environmental Quality Act
CHRIS California Historical Resources Information System City City of Sunnyvale
CLUP comprehensive land use plan
CO carbon monoxide
dBA A-weighted decibels
DDD dichlorodiphenyldichloroethane
DDE dichlorodiphenyldichloroethylene
DDT dichlorodiphenyltrichloroethane
EIR environmental impact report
EO Executive Order
EPA US Environmental Protection Agency
ESA Environmental Site Assessment
ESL environmental screening level
EV electric vehicle
Attachment 6

List of Abbreviations Ascent
City of Sunnyvale
iv De Guigne Drive Residential Project Environmental Review GHG greenhouse gas
gpd gallons per day
HI chronic health index
lb pound
Leq equivalent noise level
LID low-impact design
Lmax equivalent noise level
LOS level of service
LUTE Land Use and Transportation Element
MEIR Maximally Exposed Individual
MEIW Maximally Exposed Individual Worker
MGD million gallons per day
MRP Municipal Regional Stormwater Permit
MS Industrial and Service
MTCO2e million tons of carbon dioxide equivalent
NAAQS National Ambient Air Quality Standards
NOX nitrogen oxides
NPDES National Pollutant Discharge Elimination System
OCP organochlorine pesticide
OPR Office of Planning and Research
OSHA California Occupational Safety and Health Administration PCE perchloroethylene or tetrachloroethylene
PG&E Pacific Gas and Electric Company
PM particulate matter
PM10 respirable particulate matter with an aerodynamic diameter of 10 microns or smaller PM2.5 fine particulate matter with an aerodynamic diameter of 2.5 microns or smaller PPV peak particle velocity
PRC Public Resources Code
Project De Guigne Drive Residential Development Project PV photovoltaic
R&D research and development
Attachment 6

Ascent List of Abbreviations
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review v REC Recognized Environmental Conditions
RMED Medium Density Residential
ROG reactive organic gases
SAFE Safer Affordable Fuel-Efficient
SB Senate Bill
SMP Site Management Plan
SO2 sulfur dioxide
SR State Route
SVCE Silicon Valley Clean Energy
SWPPP stormwater pollution prevention plan
TAC toxic air contaminant
TCE trichloroethene
US US Highway
UWMP Urban Water Management Plan
VIMS vapor instruction mitigation systems
VMT vehicle miles traveled
VOC volatile organic compound
VTA Valley Transportation Authority
WPCP Donald M. Sommers Water Pollution Control Plant
WSA water supply assessment
ZEV zero-emission vehicle

Attachment 6

List of Abbreviations Ascent
City of Sunnyvale
vi De Guigne Drive Residential Project Environmental Review This page is intentionally left blank.

Attachment 6

City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 1 1 INTRODUCTION
This Environmental Checklist has been prepared by the City of Sunnyvale (City) , pursuant to Public Resources Code Section 21094.5 of the California Environmental Quality Act (CEQA) (Public Resources Code [PRC] Section 21000 et seq.) and implementing regulations in the CEQA Guidelines (Title 14, Section 15000 et seq. of the California Code of Regulations).

1.1 PURPOSE OF THE ENVIRONMENTAL CHECKLIST
Article 12 (Special Situations) of the State CEQA Guidelines identifies situations for which certain CEQA -compliance procedures may apply. Specifically, Section 15183(a) of the State CEQA Guidelines states that:

CEQA mandates that projects which are consistent with the development density established by existing zoning, community plan, or general plan policies for which an EIR was certified shall not require additional environmental review, except as might be necessary to examine whether there are project -specific significant effects which are peculiar to the project or its site. This streamlines the review of such projects and reduces the need to prepare repetitive environmental studies.

Pursuant to Section 15183(c) of the State CEQA Guidelines, “(i)f an impact is not peculiar to the parcel or to the project, has been addressed as a significant effect in the prior EIR, or can be substantially mitigated by the imposition of uniformly applied development policies or standards…then an additional EIR need not be prepared for the project solely on the basis of that impact.”
Accordingly, the purpose of the analysis contained herein is to evaluate whether the project would result in impacts not previously addressed or impacts substantially more severe than those addressed in the City of Sunnyvale Land Use and Transportation Element (LUTE) Update EIR (LUTE EIR). Alternatively, if the project does not result in any impacts beyond what was evaluated and disclosed as part of the LUTE EIR (i.e., the project is consistent with the findings of the LUTE EIR), then no additional environmental review under CEQA is required.

Because the LUTE EIR analyzed anticipated growth in Sunnyvale, including development of the project site with a mix of residential and commercial uses, this checklist identifies potential environmental impacts that qualify for streamlined review under Section 15183 of the CEQA Guidelines. Consistent with the requirements of State CEQA Guidelines Section 15183, this checklist determined that the project would not result in significant impacts peculiar to the project or project site or any significant impacts that were not analyzed or discussed in the LUTE EIR and/or are substantially mitigated by the imposition of uniformly applied development policies or standards. Additionally, the project would not result in any potentially significant off-site or cumulative impacts that were not discussed in the LUTE EIR. There are no significant effects that substantial new information shows would be more severe than discussed in the LUTE EIR. Thus, the City may rely upon the analysis in the certified LUTE EIR, and no further CEQA review is required.

1.2 LAND USE AND TRANSPORTATION ELEMENT UPDATE AND

PROJECT OVERVIEW
The Sunnyvale City Council adopted the updated LUTE of the General Plan in April 2017. The LUTE establishes the fundamental framework for the layout of streets and buildings in the City and the future establishment of various land uses, developments, and transportation facilities. The LUTE and accompanying policies were developed to help guide decision making regarding land use and transportation for an approximate 20 -year horizon—a time frame that is referred to as Horizon 2035. The LUTE land use policies provide direction for the amount, location, and direction of future change. The City prepared and certified the LUTE EIR (State Clearinghouse No. 2015062013) for the LUTE that evaluated the environmental impacts associated with development of the land uses and implementation of transportation planning efforts in Sunnyvale as regulated and guided by the LUTE.

Attachment 6

Introduction Ascent
City of Sunnyvale
1-2 De Guigne Drive Residential Project Environmental Review The project site is designated Medium Density Residential (RMED) in the Land Use and Transportation Element (LUTE) of the City of Sunnyvale General Plan; the designation provides for neighborhood-serving commercial uses integrated with residential uses. The project site is within the area covered by the East Sunnyvale Sense of Place Plan, which provides circulation and street-life improvement recommendations to aid the transition of East Sunnyvale from industrial to residential.

The project site is within proximity to multiple Valley Transportation Authority (VTA) transit stops. Several VTA route stops are accessible within less than 0.5-mile from the project site. According to the vehicle miles traveled (VMT) map (Appendix B) in the City of Sunnyvale Transportation Analysis Guidelines for Vehicle Miles Traveled and Local Transportation Analysis, the project site is located within a VMT area below the 15 percent threshold for residential uses (City of Sunnyvale 2021a). The City’s transportation policies create incentives for non-vehicular modes of transportation (transit, pedestrian, and bicycle networks), but recognize that driving will remain a significant transportation mode in Sunnyvale, while offering options for car-free or car-light living. The transportation policies integrate with the land use policies, in part by reducing travel distances by promoting compact, mixed-use development.

The proposed De Guigne Drive Residential Development Project (hereinafter referred to as the project) is located on approximately 20.55 acres at 510, 920, 930, and 950 De Guigne Drive and 935 and 945 Stewart Drive. The proposed project would consist of the demolition of six two-story office buildings and construction of a new residential community including up to 370 units, consisting of 329 primary units and 41 accessory dwelling units (ADUs). A total of 651 parking spaces would be available for residents as well as a publicly accessible multi-use path.

Attachment 6

City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 1 2 PROJECT DESCRIPTION

2.1 PROJECT OVERVIEW
The proposed De Guigne Drive Residential Development Project (project) would involve demolition of six two-story office buildings and construction of a new residential community on approximately 20.55 acres in the City of Sunnyvale (City). The new residential community would include up to 370 units, consisting of 329 primary units and 41 accessory dwelling units (ADUs), parking, internal circulation and access roads, landscaping, and a publicly accessible multi-use path. The project would be all electric (no natural gas) and would include water efficient landscaping.

2.2 PROJECT LOCATION
The approximately 20.55-acre site (project site) is located at 510, 920, 930, and 950 De Guigne Drive and 935 and 945 Stewart Drive (Assessor Parcel Numbers 205-22-022 and 205-22-023) (Figures 2-1 and 2-2). The project site is bounded by De Guigne Drive to the west and north, Stewart Drive to the south, and a park and residential uses to the east. Freeways that provide regional access to the project site include US Highway (US) 101, State Route (SR) 82, and SR 237. Access to the project site is provided via six driveways on Stewart Drive and De Guigne Drive.

2.3 EXISTING SETTING
The project site is designated as Medium Density Residential (RMED) in the Land Use and Transportation Element (LUTE) of the City of Sunnyvale General Plan and is zoned for Industrial and Service (MS) uses. Land uses adjacent to the project site include restaurant, office/R&D, recreation, and residential uses. Within one block of the project site, there are additional commercial and residential uses, as well as parks and schools.

The project site is currently developed with an existing business park, consisting of six office/research and development (R&D) buildings that were constructed between 1990 and 1995 with a combined 381,000 square feet, surface parking lots, and ornamental landscaping. The project site contains 580 trees, of which 57 are street trees, and 226 are protected under Section 19.94 of the City of Sunnyvale Municipal Code.

Onsite contamination, including but not limited to lead; tetrachloroethylene, also known as perchloroethylene (PCE); and trichloroethene (TCE) have been identified within the project site through Phase I/II Environmental Site Assessment investigations (AEI 2024a, 2024b, 2024c). The project site has developed a Site Management Plan (SMP) to address the remediation efforts required for the development of residential land uses proposed by the project.

2.4 PROJECT OBJECTIVES
The project objectives are to:
 replace outdated, energy-inefficient office/R&D buildings with housing that is similar in density and building types to surrounding residential uses;
 enhance connectivity and walkability within the existing urban fabric by providing a trail system that ties into Swegles Park and by connecting the property to the City’s existing and planned bicycle/pedestrian network;  improve water quality by upgrading on-site stormwater facilities that are outdated;  provide recreational amenities for project residents and well-maintained landscaping that enhances the community;  provide sufficient on-site parking to meet the project’s need, while also encouraging alternative modes of transportation; and
 mitigate onsite hazardous materials as necessary for the proposed use.

Attachment 6

Project Description Ascent
City of Sunnyvale
2-2 De Guigne Drive Residential Project Environmental Review

Source: Image produced by Ascent in 2025.

Figure 2-1 Regional Location
Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-3

Source: Image produced by Ascent in 2025.

Figure 2-2 Project Site
Attachment 6

Project Description Ascent
City of Sunnyvale
2-4 De Guigne Drive Residential Project Environmental Review

2.5 PROJECT DESCRIPTION
The project would involve demolition of the existing business park and redevelopment of the project site with 370 dwelling units, consisting of up to 329 primary, for-sale units and 41 ADUs, with an overall density of 18 dwelling units per acre. Figure 2-3 depicts the proposed site plan. The primary dwelling units would consist of a mix of 178 townhomes, 71 single-family alley homes, and 80 single-family court homes that would provide a range of sizes and price points to encourage diversity in the future community. All residences would be three-story units with a maximum building height of 45 feet. Figures 2-4a through 2-4c depict design renderings of the residences from public viewpoints on De Guigne Drive and Stewart Drive. Figures 2-5a through 2-5d depict building elevations of the various residence types. Fifteen percent of the primary units would be reserved for moderate-income households. These units would be dispersed throughout the new community and would have a proportionate mix of unit types as the market-rate units.

The project would include several on-site amenities to serve the recreational needs of the project residents. The project features include a 2,021-square-foot clubhouse with a lounge and meeting space, kitchen and dining area, office space, storage areas, restrooms, and 597-square-foot rear porch. Short-term bicycle parking would be provided at the clubhouse. In addition, the project would include a community pool and 711-square-foot pool building with restrooms, showers, and storage areas. The project would also include a pedestrian/bicycle trail connecting Stewart Drive to De Guigne Drive and Swegles Park along the eastern edge of the project site.

The project meets applicable floor area requirements and is eligible for waivers, as needed, through State Density Bonus Law. The applicant has requested one concession and multiple waivers from City development standards under the Sunnyvale Municipal Code.

2.5.1 Access and Parking
Access to the community would be provided via De Guigne Drive and Stewart Drive. Private streets would be provided to enhance circulation and access to the residences within the community (Figure 2-6). Each primary unit would contain a garage that fits one to two vehicles , which would provide a total of 651 covered parking spaces for project residents. An additional 116 uncovered parking spaces, including 34 electric vehicle (EV) capable stalls (i.e., infrastructure would be installed for future EV charging), would be provided for guests of the community. Project plans are included in Appendix A.

2.5.2 Landscaping and Tree Removal
In accordance with the minimum landscaped area requirements in Section 19.37.040 of the Sunnyvale Municipal Code, the project would include approximately 179,962 square feet of landscaping (Figure 2-7). Landscaping would consist of drought-tolerant plants and trees that provide color and shade without using excessive water. Paved areas would cover approximately 450,000 square feet of the project site, resulting in a net decrease in impervious surfaces from existing conditions. Additionally, the project would involve replacement of the existing, outdated on-site stormwater facilities with low-impact design (LID) features, such as bioswales and bioretention basins that that capture and filter stormwater runoff from both hardscape within the project site and the public sidewalk and roadway, encourage groundwater recharge, and reduce the speed of water flowing into the storm drain system.

The project would require removal of up to 580 trees within the project site. Of the 580 onsite trees, 226 are considered protected under the City of Sunnyvale Municipal Code Chapter 19.94 -. The project includes planting o157 24-inch box size replacement trees, resulting in a tree replacement deficit of 548 trees. Consistent with Municipal Code Section 19.94.080(b), the applicant will be required to pay a tree replacement in-lieu fee of approximately $279,480 to offset the 548 tree-replacement balance.

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-5

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-3 Site Plan
Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-7

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-4a Design Rendering 1 – Looking Northeast from the Intersection of De Guigne Drive and Stewart Drive Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-9

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-4b Design Rendering 2 – Looking Northwest from Stewart Drive Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-11

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-4c Design Rendering 3 – Looking Southwest from De Guigne Drive Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-13

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-5a Building Elevations – Alley Homes
Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-15

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-5b Building Elevations – Court Homes
Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-17

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-5c Building Elevations – Attached Row Townhomes Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-19

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-5d Building Elevations – Attached Interlocking Townhomes Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-21

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-6 Circulation Plan
Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-23

Source: Image produced by WHA Architects from project plan set dated June 4, 2025.

Figure 2-7 Landscape Plan
Attachment 6

Attachment 6

Ascent Project Description
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 2-25

2.5.3 Utility Infrastructure
Existing utility infrastructure in and around the project area includes a natural gas main, 10-inch water pipeline, 27-33- inch storm drains pipelines, and a 12-inch sanitary sewer pipeline, and electric and communication infrastructure along De Guigne Drive. Along Stewart Drive, existing utilities include a gas main, 10 -inch water pipeline, 21-inch storm drain pipeline, 10-inch sanitary sewer pipeline, and electric and communication infrastructure. As described above, much of the outdated stormwater infrastructure would be replaced with LID features within the project site. The project would include installation of the following utility infrastructure: additional storm drainpipes, sanitary sewer pipelines, water laterals, irrigation water laterals, fire service laterals, fire hydrants, and Pacific Gas and Electric transformers. The project would be all-electric design and would not connect to existing natural gas infrastructure in the project area.

2.5.4 Design Features
The project design incorporates sustainable features, including rooftop solar, wiring for electric vehicle chargers (i.e., EV-capable spaces), energy efficient lighting, low-water fixtures, and an all-electric design.

The project site has undergone several investigations, including soil gas sampling, for hazardous conditions, as lead, PCE, TCE, Benzene, and chloroform have been identified in areas of the site through site investigations (AEI 2024 a; AEI 2024b; AEI 2025a; SWRCB 2025). Results of the sampling will continue to inform appropriate site cleanup procedures, as well as the site design, including the installation of vapor intrusion mitigation systems in select residential buildings as determined by the Site Management Plan (SMP) (AEI 2025b). Section 4.9, “Hazards and Hazardous Materials,” below, includes further information related to onsite conditions.

2.6 CONSTRUCTION
Construction activities would occur in at least three phases with an estimated construction duration of 18 months.

Consistent with General Plan Policy LT-1.10e, the City will require the applicant to evaluate and ensure mitigation of potential biological impacts of development projects in a manner consistent with applicable local, state, and federal laws and regulations, including conducting nesting bird and bat surveys. Consistent with Section 16.08.030 of the Sunnyvale Municipal Code, working hours would be limited to between 7:00 a.m. and 6:00 p.m., Monday through Friday, and 8:00 a.m. to 5:00 p.m. on Saturday. The stages of construction are anticipated to include demolition (50 working days), grading (35 working days), building construction (300 working days), paving (20 working days), and architectural coatings (20 working days). Remediation also would occur as required by the oversight authority and in compliance with the SMP. Off-road equipment used during construction would include air compressors, concrete/industrial saws, cranes, excavators, forklifts, generators, graders, dozers, rollers, scrapers, tractors/loaders/back hoes, and welders. Approximately 34,514 tons of demolition debris would be generated and up to 10,000 cubic yards of material would be exported during construction due to spoils. Approximately 9,910 haul trips are anticipated for removal of construction and demolition debris. Worker trips are estimated to range from 15 to 211 daily trips. In accordance with Bay Area Air Quality Management District regulations, all active construction areas would be watered twice daily for dust control.

As noted above, the project is developing a SMP to address on-site contamination. Implementation of the SMP may include soil contamination management and disposal standards that would be implemented during construction.

2.7 REQUIRED ACTIONS
The project would require the following discretionary actions by the City:
 Approval of a use permit to allow for development of single-family homes in the medium density residential zoning district (R-3);
Attachment 6

Project Description Ascent
City of Sunnyvale
2-26 De Guigne Drive Residential Project Environmental Review  Approval of a tree removal permit consistent with Municipal Code Chapter 19.94 for the removal of onsite trees and associated approval of replacement tree in-lieu fee pursuant to Section 19.94.080(b); and  Approval of a vesting tentative map.

In addition, the following permits and approvals are anticipated to be required from other agencies:
 Site Management Plan approval from the San Francisco Bay Regional Water Quality Control Board (Region 2) ;  Construction General Permit from the State Water Resources Control Board; and  Demolition Permit from the Bay Area Air District.

Attachment 6

City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 1 3 INTRODUCTION TO THE ENVIRONMENTAL CHECKLIST

3.1 EXPLANATION OF CHECKLIST EVALUATION CATEGORIES
The LUTE EIR was prepared as a program EIR consistent with the requirements of CEQA. The analysis considered the environmental impacts of development buildout that could occur under the LUTE (assumed to be year 2035) .

As discussed in Chapter 1, the proposed project is consistent with the LUTE policy provisions. State CEQA Guidelines Section 15183 dictates that, in circumstances such as these, a lead agency “shall not require additional environmental review, except as might be necessary to examine whether there are project-specific significant effects which are peculiar to the project or its site.” Section 15183 further indicates that an initial study or other analyses should be prepared by a lead agency to determine the scope of environmental review in light of this prohibition. The purpose of this process is to streamline the review of covered projects and reduce the need for the preparation of repetitive environmental studies.

Under Section 15183, the lead agency’s initial study checklist (based on State CEQA Appendix G and the impact analysis provided in the LUTE EIR) is used to determine whether the following types of impacts may merit additional environmental analysis:

1. Are peculiar to the project or the parcel on which the project would be located,

2. Were not analyzed as significant effects in a prior EIR on the zoning action, general plan , or community plan with which the project is consistent,

3. Are potentially significant off-site impacts and cumulative impacts which were not discussed in the prior EIR prepared for the general plan, community plan or zoning action, or

4. Are previously identified significant effects which, as a result of substantial new information which was not known at the time the EIR was certified, are determined to have a more severe adverse impact than discussed in the prior EIR.

The purpose of this checklist is to evaluate the categories listed in CEQA Guidelines Section 15183 to determine whether, in light of the LUTE EIR, there are any significant environmental effects requiring additional environmental analysis. The purpose of each column of the checklist is described below.

Where Impact Was Analyzed in LUTE Draft and Final EIR?
This column cross-references the pages of the LUTE EIR where information and analysis may be found relative to the environmental issue listed under each topic.

Any Peculiar Impact?
Pursuant to CEQA Guidelines Sections 15183(b)(1) and 15183(f), this column indicates whether the project could result in a peculiar impact, including a physical change that belongs exclusively or especially to the proposed project or that is a distinctive characteristic of the project or the project site and that peculiar impact is not substantially mitigated by the imposition of uniformly applied development policies or standards.

Any Impact Not Analyzed as Significant Effect in LUTE EIR? Pursuant to CEQA Guidelines Section 15183(b)(2), this column indicates whether the proposed project would result in a significant effect that was not analyzed as significant in the LUTE EIR. A new EIR is not required if such a project impact can be substantially mitigated by the imposition of uniformly applied development policies or standards.

Attachment 6

Environmental Review Ascent
City of Sunnyvale
3-2 De Guigne Drive Residential Project Environmental Review Any Significant Off-Site or Cumulative Impact Not Analyzed? Pursuant to CEQA Guidelines Section 15183(b)(3), this column indicates whether the proposed project would result in a significant off-site or cumulative impact that was not discussed in the LUTE EIR. A new EIR is not required if such an off-site or cumulative impact can be substantially mitigated by the imposition of uniformly applied development policies or standards.

Any Adverse Impact More Severe Based on Substantial New Information?
Pursuant to CEQA Guidelines Section 15183(b)(4), this column indicates whether there is substantial new information that was not known at the time the LUTE EIR was certified, indicating that there would be a more severe adverse impact than discussed in the LUTE EIR. A new EIR is not required if such an impact can be substantially mitigated by the imposition of uniformly applied development policies or standards.

Do EIR Mitigation Measures or Uniformly Applied Development Policies or Standards Address/Resolve Impacts?
This column indicates whether the LUTE EIR and adopted CEQA Findings incorporate mitigation measures to address effects in the related impact category. In some cases, the mitigation measures have already been implemented. This column also indicates whether uniformly applied development standards or policies address identified impacts. A “yes” response will be provided if the impact is addressed by a LUTE mitigation measure or uniformly applied development standards or policies. If “NA” is indicated, this Environmental Checklist review concludes that there was no impact, the adopted mitigation measures are not applicable to this proposed project, or the impact was less than significant with implementation of City requirements and, therefore, no mitigation measures are needed.

3.2 DISCUSSION AND MITIGATION SECTIONS
Discussion
The elements of the checklist are discussed under each environmental category to clarify the answers. The discussion provides information about the particular environmental issue, how the proposed project relates to the issue, and the status of any mitigation that may be required or that has already been implemented.

Mitigation Measures
Applicable mitigation measures from the prior environmental review that would apply to the proposed project are listed under each environmental category.

Conclusions
A discussion of the conclusion relating to the need for additional environmental documentation is contained in each section.

Attachment 6

City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 1 4 ENVIRONMENTAL CHECKLIST

4.1 AESTHETICS
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

1. Aesthetics. Would the project:
a) Have a substantial adverse effect
on a scenic vista?
Draft EIR Setting
pp. 3.12-1 to

3.12-5
Impacts 3.12.1
and 3.12.5
No No No No NA, no impact would
occur
b) Substantially damage scenic
resources, including but not limited
to, trees, rock outcroppings, and
historic buildings within a state
scenic highway?
Draft EIR Setting
pp. 3.12-1 to

3.12-5
Impacts 3.12.2
and 3.12.5
No No No No NA, no impact would
occur
b) 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?
Draft EIR Setting
pp. 3.12-1 to

3.12-5
Impacts 3.12.3
and 3.12.5
No No No No NA, impact remains
less than significant
c) Create a new source of
substantial light or glare which
would adversely affect day or
nighttime views in the area?
Draft EIR Setting
pp. 3.12-1 to

3.12-5
Impacts 3.12.4
and 3.12.5
No No No No NA, impact remains
less than significant

4.1.1 Discussion
No substantial change in the environmental and regulatory settings related to aesthetics, described in LUTE Draft EIR Section 3.12, “Visual Resources and Aesthetics,” has occurred since certification of the EIR in April 2017. a) Have a substantial adverse effect on a scenic vista? As discussed under Impact 3.12.1 of the LUTE Draft EIR, Sunnyvale does not have any designated scenic vistas, but there are several trees and historic resources, as well as the Libby Water Tower, the Murphy Station Heritage Landmark District, and the cherry orchards on Mathilda Avenue, that comprise important local scenic attributes. The LUTE Draft EIR identified no significant project or cumulative (Impact 3.12.5) impacts on scenic vistas that would occur with buildout under the General Plan.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-2 De Guigne Drive Residential Project Environmental Review The project site is located in an existing developed area with office and residential uses and does not include any visual resources, features, or scenic vistas, and redevelopment of the site would not alter public views of City attributes designated as scenic. Therefore, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required. b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway? Impact 3.12.2 of the LUTE Draft EIR identified that there are no designated state scenic highways in the City. There remains no designated state scenic highways in the City. Therefore, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required 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?
Impact 3.12.3 of the LUTE Draft EIR identified that new development under the LUTE would mostly be concentrated around transit nodes and other areas that are visually appropriate for increased development intensities and densities and structure heights compared to existing developed conditions. The LUTE would result in new urban uses that would complement the City’s existing urban character. The LUTE policies and associated actions require compliance with design guidelines for future development subsequent to the LUTE and would maintain compatibility with existing surrounding neighborhoods. The LUTE Draft EIR identified that no significant project or cumulative (Impact

3.12.5) impacts on visual character would occur.

The project site is located in an existing developed, urbanized area that includes residential, and office uses and is consistent with applicable zoning and design guideline regulations. The proposed project would be designed to comply with applicable standards (those standards not made inapplicable through State Density Bonus Law) in Municipal Code

18.12 (i.e., design standards for subdivisions) and Citywide Objective Design Standards, and would be visually consistent with developed residential uses surrounding the De Guigne Drive and Stewart Drive corridors (see Figures 2-4a through 2-4c and 2-5a through 2-5d). Project landscaping would enhance the existing visual character of the street frontage along De Guigne Drive and Stewart Drive (see Figure 2-7). Therefore, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required. d) Create a new source of substantial light or glare which would adversely affect day or nighttime views in the area?
Impact 3.12.4 of the LUTE Draft EIR identified that future development under the LUTE would not result in substantial increases in existing daytime glare or nighttime lighting conditions in the City. Citywide Design Guideline 3.B9 provides guidance on reducing light impacts and associated glare. Guideline 2.E3 cites design considerations to address glare, such as avoiding large expanses of highly reflective surfaces and mirror glass exterior walls.

Furthermore, compliance with Sunnyvale Municipal Code Section 19.42.050 regarding restrictions on lighting would ensure that all lights, spotlights, floodlights, reflectors, and other means of illumination are shielded or equipped with special lenses in such a manner as to prevent any glare or direct illumination on any public street or other property.

The LUTE Draft EIR identified that no significant project or cumulative (Impact 3.12.5) impacts from glare and nighttime lighting would occur.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-3 The project site is located in a developed area of the City that contains existing sources of daytime glare from buildings as well as nighttime lighting from buildings, street lighting, and parking lot lighting. The proposed residential buildings would include architectural treatments designed to address glare. The proposed project is also subject to compliance to the lighting requirements in Sunnyvale Municipal Code Section 19.42.050 regarding the shielding of lighting. The project would be required to meet the City’s lighting requirements and policies designed to prevent glare and direct illumination beyond the project’s property line. Project plan set sheet SL-1 and SL-2 address the extent of illumination as required by the City (Appendix A). Therefore, with application of uniformly applied development standards and policies, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required.

Mitigation Measures
No significant aesthetic impacts were identified in the LUTE EIR, and no mitigation measures were required.

Conclusion
There are no significant impacts that are peculiar to the proposed project or the site on which it would be located. No new aesthetic impacts have occurred nor has any new information been found requiring new analysis or verification.

The project is consistent with applicable general plan and zoning standards related to aesthetics, would not affect scenic resources or views, and would be required to comply with lighting standards under Sunnyvale Municipal Code Section 19.42.050. Thus, the project would not have any potentially significant off-site impacts or cumulative impacts that were not discussed in the LUTE EIR. Therefore, the conclusions of the LUTE EIR remain valid and approval of the proposed project would not
require additional environmental review.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-4 De Guigne Drive Residential Project Environmental Review

4.2 AGRICULTURE AND FOREST RESOURCES
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or
Uniformly Applied
Development Policies
or Standards Address/
Resolve Impacts?

2. Agriculture and Forestry Resources. 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?
Scoped out at
Notice of
Preparation stage.

Resources do not
exist in the City.

No No No No NA
b) Conflict with existing zoning for
agricultural use, or a Williamson
Act contract?
Scoped out at
Notice of
Preparation stage.

No agricultural
zoning or
Williamson Act
contracted lands
exist in the City.

No No No No NA
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))?
Scoped out at
Notice of
Preparation stage.

Resources do not
exist in the City.

No No No No NA
d) Result in the loss of forest land or
conversion of forest land to non-
forest land?
Scoped out at
Notice of
Preparation stage.

Resources do not
exist in the City.

No No No No NA
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?
Scoped out at
Notice of
Preparation stage.

Resources do not
exist in the City.

No No No No NA

4.2.1 Discussion and Conclusion
Agricultural and forestry impacts were scoped out of the LUTE EIR at the Notice of Preparation stage , as these resources do not exist in Sunnyvale. The project site does not contain any of these resources and would also have no impact.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-5

4.3 AIR QUALITY
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any
Peculiar
Impact?
Any Impact Not
Analyzed as
Significant Effect
in LUTE EIR?
Any Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or
Uniformly Applied
Development
Policies or
Standards
Address/Resolve
Impacts?

3. Air Quality. Would the project:
a) Conflict with or obstruct
implementation of the
applicable air quality plan?
Draft EIR Setting
pp. 3.5-1 to 3.5-13
Impact 3.5.1
No No No No NA, impact
remains less than
significant
b) Violate any air quality standard
or contribute substantially to an
existing or projected air quality
violation?
Draft EIR Setting
pp. 3.5-1 to 3.5-13
Impacts 3.5.2,

3.5.3, and 3.5.8
No No No No Yes, but impact
remains significant
and unavoidable
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 releasing
emissions which exceed
quantitative thresholds for
ozone precursors)?
Draft EIR Setting
pp. 3.5-1 to 3.5-13
Impacts 3.5.2,

3.5.3, and 3.5.8
No No No No Yes, but impact
remains significant
and unavoidable
d) Expose sensitive receptors to
substantial pollutant
concentrations?
Draft EIR Setting
pp. 3.5-1 to 3.5-13
Impacts 3.5.4,

3.5.5, 3.5.6, and

3.5.8 No No No No NA, but impact
remains significant
and unavoidable
e) Create objectionable odors
affecting a substantial number
of people?
Draft EIR Setting
pp. 3.5-1 to 3.5-13
Impact 3.5.7
No No No No NA, impact
remains less than
significant

4.3.1 Discussion
There have been changes in the regulatory setting related to air quality, described in LUTE Draft EIR Section 3.5, “Air Quality,” since certification of the EIR in April 2017, but these changes do not result in any new analysi s requirements such that any new or more severe significant effects would occur than were analyzed in the LUTE EIR. The following notable changes to the regulatory setting regarding vehicle emissions standards have occurred since certification of the LUTE EIR.

On June 12, 2025, Public Law No. 119-16, enacting House Joint Resolution 88, became law. The law also relied on the Congressional Review Act to disapprove the EPA’s December 2024 waiver under the CAA that allowed California to implement and enforce the Advanced Clean Cars II (ACC II) regulation. ACC II included a zero-emission vehicle (ZEV) mandate targeting 100 percent new light-duty ZEV sales by 2035. The implications of this law on the State’s capability to enforce its independent fuel economy standards are uncertain at this time, as the California Attorney General filed a lawsuit challenging P.L. No. 119-16 on June 12, 2025. Whether this action will be successful is unknown, as is the possibility that a federal judge will issue a stay to halt the implementation of the ACC II regulation during the legal Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-6 De Guigne Drive Residential Project Environmental Review process. Notably, the LUTE EIR was drafted and adopted prior to the introduction of the ACC II regulation and thus would not have accounted for any emissions reductions associated with the regulation.

Public Law 119–17, enacted on June 12, 2025, disapproves, under the Congressional Review Act, the EPA’s rule titled “California State Motor Vehicle and Engine and Nonroad Engine Pollution Control Standards; The ‘Omnibus’ Low NOX Regulation; Waiver of Preemption; Notice of Decision.” The law disapproves the EPA’s January 6, 2025, Low-NOX rule that would have granted California a waiver to enforce stricter emissions standards for both on-road and non-road heavy-duty engines. Similar to the other CRA resolutions listed above targeting emissions waivers, this law prohibits the EPA from reissuing the same or substantially similar rule without new authorization from Congress. The law effectively blocks California, and any states following its standards, from implementing this omnibus Low-NO X
regulatory package. Again, the implications of this federal law on the State’s capability to enforce its independent Low NO
X regulatory package are uncertain at this time, as the California Attorney General filed a lawsuit challenging Public Law No. 119-17 on June 12, 2025. Whether this action will be successful is unknown, as is the possibility that a federal judge will issue a stay to halt the implementation of the Low NOX regulatory package during the legal process.

Notably, the LUTE EIR was drafted and adopted prior to the introduction of the Low-NOX rule and thus would not have accounted for any potential emissions reductions associated with the rule.

In consideration of new sources of criteria air pollutant and ozone precursor emissions associated with new stationary and land use development, as well as mobile source emissions associated with statewide and regional population growth, the attainment status of Santa Clara County, where the project site is located, has changed since the certification of the LUTE Update EIR. The US Environmental Protection Agency (EPA) does not enforce a 1- hour ozone standard unless an area is designated as non-attainment for the 8-hour ozone national ambient air quality standards (NAAQS). On February 7, 2024, EPA updated the NAAQS for PM to 9.0 micrograms per cubic meter (µg/m³). As shown in Table 4.3-1, Santa Clara County is in nonattainment for the 8-hour ozone standard and is thus subject to enforcement of the 1-hour standard. Santa Calara County has attained the 1-hour ozone and respirable particular matter NAAQS. Attainment status refers to whether the air quality for specific pollutants in a geographic area meets or is cleaner than adopted national and/or state standards. This analysis reflects the current understanding of the attainment standards for air quality and relies upon the most recent NAAQS and California a mbient air quality standards (CAAQS). Areas that meet the NAAQS/CAAQS for those pollutants are called attainment areas, and those that do not meet the NAAQS/CAAQS are called nonattainment areas.

Since certification of the LUTE EIR in April 2017, the Bay Area Air District (formerly Bay Area Air Quality Management District [BAAQMD]) updated its CEQA Guidelines in May of 2017 but did not make any substantive changes to its recommended thresholds. In December 2018, the Governor’s Office of Land Use and Climate Innovation [LCI, formerly the Office of Planning and Research (OPR)] finalized updates to the CEQA Guidelines. The final adopted text included revisions to the significance criteria in Appendix G of the CEQA Guidelines. The following impact analysis uses the most recent iteration of the Appendix G guidelines and, where appropriate, have been aligned with the significance criteria used in the LUTE EIR. On April 20, 2022, the Bay Area Air District u pdated its CEQA Guidelines (2022 CEQA Guidelines) establishing new methodologies, protocols, and thresholds of significance for climate impacts; however, this update did not include any updates to air quality thresholds. The 2022 CEQA Guide has undergone several revisions; however, no revisions have affected the Bay Area Air District’s recommended mass emissions thresholds of significance for criteria air pollutants or cancer and non- cancer risk for TACs.

On April 19, 2017, the Bay Area Air District adopted an updated Clean Air Plan. Like the 2010 Clean Air Plan, the 2017 Clean Air Plan contains a regional strategy to protect public health and protect the climate. The 2017 Clean Air Plan updates the most recent Bay Area ozone plan, the 2010 Clean Air Plan, pursuant to air quality planning requirements defined in the California Health and Safety Code. To fulfill state ozone planning requirements, the 2017 control strategy includes all feasible measures to reduce emissions of ozone precursors —reactive organic gases (ROG) and nitrogen oxides (NO
X)—and reduce transport of ozone and its precursors to neighboring air basins. In addition, the 2017 Clean Air Plan builds on the Bay Area Air District’s efforts to reduce emissions of fine particulate matter (PM) and toxic air contaminants (TACs).

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-7 Table 4.3-1 Attainment Status Designations for Santa Clara County Pollutant NAAQS CAAQS
Ozone Attainment (1-hour)1 Nonattainment (1-hour) Classification2 Nonattainment (8-hour)3 Classification – Marginal Nonattainment (8-hour)

Nonattainment (24-hour)
Respirable particulate matter (PM10) Attainment (24-hour) Nonattainment (24-hour) Nonattainment (Annual)
Fine particulate matter (PM2.5) Attainment (24-hour) (No State Standard for 24-Hour) Attainment (Annual) Nonattainment (Annual)
Carbon monoxide (CO) Attainment (Maintenance) (1-hour) Attainment (1-hour) Attainment (Maintenance) (8-hour) Attainment (8-hour)
Nitrogen dioxide (NO2) Attainment (Maintenance) (1-hour) Attainment (1-hour) Attainment (Maintenance) (Annual) Attainment (Annual)
Sulfur dioxide (SO2)4 Attainment (1-Hour) Attainment (1-hour) Attainment (3-month rolling avg.) Attainment (24-hour) Lead (Particulate) Attainment (3-month rolling avg.) Attainment (30-day average) Hydrogen Sulfide Unclassified (1-hour)
Sulfates No Federal Standard Attainment (24-hour)
Visibly Reducing Particles Unclassified (8-hour)
Vinyl Chloride Unclassified (24-hour)
Notes: NAAQS = national ambient air quality standards; CAAQS = California ambient air quality standards 1 Air Quality meets federal 1-hour Ozone standard (77 FR 64036). EPA revoked this standard, but some associated requirements still apply. 2 Per Health and Safety Code Section 40921.5(c), the classification is based on 1989–1991 data, and therefore does not change. 3 2015 Standard.
4 2010 Standard.

Source: EPA 2025; CARB 2023.

An air quality analysis was completed for the project as part of preparation of the Air Quality, Greenhouse Gas Emissions, and Energy Analysis Report (AQ, GHG, and Energy Report) and subsequent memorandum detailing the findings of the analysis for the proposed project (FirstCarbon Solutions 2025 a). The results of this analysis are summarized below.
a) Conflict with or obstruct implementation of the applicable air quality plan? Impact 3.5.1 of the LUTE Draft EIR evaluated whether the LUTE would conflict with or obstruct implementation of the applicable air quality plan. Bay Area Air District’s 2010 Clean Air Plan includes various control strategies to reduce emissions of local and regional pollutants and to promote health and energy conservation. As stated in Impact 3.5.1, the LUTE supports the goals of, includes applicable pollutant control mechanisms, and is consistent with the 2010 Clean Air Plan. Therefore, this impact was determined to be less than significant.

No changes in the air quality conditions for the project site have occurred since adoption of the LUTE. The proposed project would be consistent with land use designations and would not include any development beyond that assumed and analyzed in the LUTE EIR. Table 2 of the AQ, GHG, and Energy Report provides a summary of the proposed project’s design features which are consistent with the control measures of the 2017 Clean Air Plan (FirstCarbon Solutions 2025a).

Additionally, projects which exceed Bay Area Air District thresholds for operational and construction emissions would conflict with the goal of the 2017 Clean Air Plan to attain the NAAQS and CAAQS and limit health impacts from TACs. As demonstrated in Tables 4 and 5 of the AQ, GHG, and Energy Report, the project would not exceed the Bay Area Air Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-8 De Guigne Drive Residential Project Environmental Review Districts numerical thresholds for construction-related or operational emissions. Additionally, per Bay Area Air District guidance, projects must implement mandatory best management practices (BMPs) during construction to achieve less than significant construction-related dust emissions. The City’s LUTE EIR includes a mitigation measure requiring projects to incorporate basic construction mitigation measures from Table 8-1 of the Bay Area Air District’s 2011 CEQA Air Quality Guidelines (or subsequent updates) on the construction documents. Accordingly, the latest applicable Bay Area Air District’s CEQA 2022 CEQA Guidelines air pollution control measures shall be implemented during construction activities consistent with LUTE EIR MM 3.5.3 New Policy 1 (subsequently adopted as General Plan Policy EM-11.10 [EJ]). In addition, the proposed project would comply with all applicable district rules, including Regulation 6, Rule 1 (General Requirements) and Regulation 6, Rule 6 (Prohibition of Trackout), which require dust generating operations to limit PM emissions.

With the incorporation of LUTE EIR MM 3.5.3 New Policy 1 (subsequently adopted as General Plan Policy EM-11.10 [EJ]), there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR concerning consistency with air quality plans remain valid and no further analysis is required. b) Violate any air quality standard or contribute substantially to an existing or projected air quality violation? and
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?
Impacts 3.5.2, 3.5.3, and 3.5.8 of the LUTE Draft EIR identified that implementation of the LUTE would result in short - term construction and long-term operational emissions that would substantially contribute to air pollution or result in a cumulatively considerable net increase of a criteria pollutant. The analysis noted that, while contribution of the LUTE to adverse impacts to air quality would be cumulatively considerable, the Bay Area Air District’s significance thresholds, as applied to each individual project, would be used to determine whether a project’s contribution to a significant impact to air quality would be cumulatively considerable.

The City adopted Mitigation Measure 3.5.3 (subsequently adopted as General Plan Policy EM-11.10 [EJ]) which requires construction projects to implement the Bay Area Air District’s basic construction mitigation measures as well as use construction equipment that is California Air Resources Board (CARB) Tier 3 Certified or better to address construction emissions. The LUTE Draft EIR identified that the LUTE would improve the viability of walking, biking, and transit that would reduce vehicle use. However, the LUTE EIR concluded that construction and operational air quality impacts of LUTE implementation were significant and unavoidable under project and cumulative conditions (Impact 3.5.8).

Construction– and operations-related emissions of air pollutants as a result of the project were calculated using the California Emissions Estimator Model, as recommended by Bay Area Air District and other air districts in the state. Air quality modeling input and output parameters, detailed assumptions, and construction and operational emissions estimates are provided in the AQ, GHG, and Energy Report (FirstCarbon Solutions 2025a).

For purposes of the air quality impact analysis in the Air Quality, GHG, and Energy Analysis Report, the duration of activity and associated equipment represent a reasonable approximation of the expected construction fleet. Demolition of the surface parking lot and solar canopies could generate fugitive dust emissions and exhaust NO X, respirable
particulate matter with an aerodynamic diameter of 10 microns or smaller (PM 10), and fine particulate matter with an aerodynamic diameter of 2.5 microns or smaller (PM2.5). New construction could generate dust and particulate matter from soil disturbance. The use of heavy-duty equipment for demolition and construction activities would generate exhaust emissions such as NOX, sulfur dioxide (SO2), carbon monoxide (CO), ROG, PM10, and PM2.5. Construction of the project is estimated to begin in third quarter 2026 and last approximately 18 months. Vertical construction of the units would be conducted in three phases. However, for the purpose of emission modeling, home construction is modeled as one phase. Notably, construction emissions would likely decrease if the construction schedule were deferred to later years because of improvements in emissions control technology and more stringent regulatory requirements. The duration of construction activity and associated equipment represents a reasonable approximation of the expected construction fleet as CEQA Guidelines require.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-9 Table 4.3-2 Summary of Annual and Average Daily Exhaust Emissions of Criteria Air Pollutants and Precursors Associated with Project Construction
Construction Year ROG NOX PM10 (Exhaust) PM2.5 (Exhaust) 2026 (tons/yr) 0.1 1.4 <0.1 <0.1
2027 (tons/yr) 0.2 1.6 0.1 <0.1
2028 (tons/yr) 6.2 0.4 <0.1 <0.1
Total Emissions (tons) 6.5 3.5 0.1 0.1
Total emissions (lbs) 13,013 6,900 221 204
Average Daily Emissions (lbs/day) 34 18 1 1
Significance Threshold (lbs/day) 54 54 82 54
Exceeds Significance Threshold? No No No No
Notes: lbs/day = pounds per day; tons/yr = tons per year; ROG = reactive organic gases; NOX = oxides of nitrogen; PM10 = respirable particulate matter; PM2.5 = fine particulate matter
Maximum Daily Exhaust Emissions represent maximum daily level for each pollutant over the entire construction period.

Source: Modeling performed by FirstCarbon Solutions in 2025.

As shown in Table 4.3-2, the construction emissions from all construction activities would not exceed Bay Area Air District’s applicable thresholds of significance. However, fugitive PM10 and PM2.5 dust emissions could contribute to localized pollutant concentrations that exceed applicable national ambient air quality standards and/or California ambient air quality standards if dust control measures are not implemented. As noted above, LUTE EIR Mitigation Measure 3.5.3 requires construction projects to implement the Bay Area Air District’s basic dust BMPs which include the following dust control measures:
 All exposed surfaces (e.g., parking areas, staging areas, soil piles, graded areas, and unpaved access roads) shall be watered two times per day.
 All haul trucks transporting soil, sand, or other loose material off-site shall be covered.  All visible mud or dirt trackout onto adjacent public roads shall be removed using wet power vacuum street sweepers at least once per day. The use of dry power sweeping is prohibited.  All vehicle speeds on unpaved roads shall be limited to 15 mph.  All roadways, driveways, and sidewalks to be paved shall be completed as soon as possible. Building pads shall be laid as soon as possible after grading unless seeding or soil binders are used.  All excavation, grading, and/or demolition activities shall be suspended when average wind speeds exceed 20 mph.  All trucks and equipment, including their tires, shall be washed off prior to leaving the site.  Unpaved roads providing access to sites located 100 feet or further from a paved road shall be treated with a 6 - to 12-inch layer of compacted layer of wood chips, mulch, or gravel.  Publicly visible signs shall be posted with the telephone number and name of the person to contact at the lead agency regarding dust complaints. This person shall respond and take corrective action within 48 hours. The Air District’s General Air Pollution Complaints number shall also be visible to ensure compliance with applicable regulations.

The project would be required to implement Mitigation Measure 3.5.3 (subsequently adopted as General Plan Policy EM-11.10 [EJ]), identified in the LUTE EIR, to reduce the air quality impacts of short-term construction.

Operation of the project would begin following the end of the construction period in 2028. Operational emissions would include area, energy, mobile, and stationary sources. Area sources would include emissions from architectural coatings, consumer products, and landscape equipment. Consistent with the City’s Reach Code, the project would be all electric and would not result in any direct emissions related to building energy use for space or water heating.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-10 De Guigne Drive Residential Project Environmental Review Mobile sources include exhaust and road dust emissions from the vehicles that would travel to and from the project site. CalEEMod defaults for trip generation were used for this analysis. The project would replace the existing commercial uses on-site, but for conservative purposes, the analysis does not account for the removal of the existing emissions such as car trips that would be replaced by the project. Pollutants of concern include ROG, NOX, PM10, and PM2.5. The estimated maximum daily net emissions are summarized in Table 4.3-3.

Table 4.3-3 Summary of Annual and Average Daily Exhaust Emissions of Criteria Air Pollutants and Precursors Associated with Project Operation
Source ROG NOX PM10 (Total) PM2.5 (Total)
Annual Emissions
Mobile 1.4 0.9 2 0.5
Area 4.1 <0.1 <0.1 <0.1
Energy — — — —
Total (tons/year) 5.5 0.9 2 0.5
Significance Threshold (tons/year) 10 10 15 10
Exceeds Significance Threshold? No No No No
Average Daily Emissions
Average Daily Emissions (lbs/day) 30 5 11 3
Significance Threshold (lbs/day) 54 54 82 54
Exceeds Significance Threshold? No No No No
Notes: lbs/day = pounds per day; ROG = reactive organic gases; NOX = oxides of nitrogen; PM10 = respirable particulate matter; PM2.5 = fine particulate matter
Source: Modeling performed by FirstCarbon Solutions in 2025.

As shown in Table 4.3-3, the project would not result in net operational-related air pollutants or precursors that would exceed the Bay Area Air District’s thresholds of significance, exceedance of which would indicate that proposed operation would be considered to have the potential to generate a significant quantity of air pollutants (FirstCarbon Solutions 2025a).

With application of Mitigation Measure 3.5.3 (subsequently adopted as General Plan Policy EM-11.10 [EJ]), construction and operational emissions would not exceed Bay Area Air District thresholds. Therefore, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required.
d) Expose sensitive receptors to substantial pollutant concentrations? Impacts 3.5.4, 3.5.5, 3.5.6, and 3.5.8 of the LUTE Draft EIR evaluated whether construction and operational activities would expose sensitive receptors to substantial pollutant concentrations of TACs. Sensitive receptors include residences, schools, medical facilities, family day cares, and places of worship. Construction-related TACs potentially affecting sensitive receptors include off-road diesel-powered equipment, and operational TACs include mobile and stationary sources of diesel particulate matter. Both of these impacts are identified in the LUTE EIR as potentially significant. Implementation of Mitigation Measures 3.5.5 and 3.5.6 (subsequently adopted as General Plan Policy EM-

11.4 [EJ]), in addition to Bay Area Air District permitting requirements, were determined in the LUTE EIR to provide adequate mitigation to reduce these impacts to less than significant under project conditions, but found that the LUTE’s contribution to significant cumulative impacts would be cumulatively considerable (Impact 3.5.8).

The Maximally Exposed Individual (MEIR) is a multi-family residence located immediately adjacent to the southeast of the project site. Additionally, consistent with Bay Area Air District guidance, the cancer risks, chronic health index (HI), and PM

2.5 concentration at the MEI Worker (MEIW) and school within 1,000 feet of the project site are also disclosed.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-11 Table 4.3-4 summarizes the project’s construction cancer risk, chronic non-cancer hazard, and annual PM2.5 concentration impacts at the MEIR prior to and after the application of any equipment -related mitigation.

Additionally, consistent with BAAD guidance, the cancer risks, HI, and PM2.5 concentration at the MEIW and school within 1,000 feet of the project site are also disclosed.

Table 4.3-4 Estimated Health Risks and Hazards during Project Construction – Unmitigated Scenario Average DPM
(µg/m3)
Cancer Risk
(risk per million)
Chronic Non-Cancer
Hazard Index
Annual PM2.5
(µg/m3)
Maximum Exposed Individual Resident (MEIR) 0.05428 11.9 0.011 0.10576 Maximum Exposed Individual Worker (MEIW) 0.06617 1.1 0.013 0.12893 The Kings Academy (Middle and High School) 0.00126 0.13 <0.001 0.00251 Maximum Exposed Individual 11.9 0.013 0.129
Bay Area Air District Thresholds of Significance 10 1 0.3 Exceeds Individual Source Threshold? Yes No No
Notes: µg/m3 = micrograms per cubic meter; DPM = diesel particulate matter; MEIR = Maximally Exposed Individual Receptor; PM2.5 = articulate matter less than 2.5 microns in diameter.

Source: Modeling performed by FirstCarbon Solutions in 2025.

As identified in Table 4.3-4, construction of the proposed project without LUTE EIR MM 3.5.3 New Policy 2 (subsequently adopted as General Plan Policy EM-11.10 [EJ]) (Tier 3 construction equipment with diesel particulate filter) would result in the exceedance of one of the three applicable Bay Area Air District cancer risk thresholds.

Table 4.3-5 summarizes construction related health risks and hazards with application of LUTE EIR MM 3.5.3 New Policy 2 (subsequently adopted as General Plan Policy EM-11.10 [EJ]).

Table 4.3-5 Estimated Health Risks and Hazards during Project Construction –Mitigated Scenario Average DPM
(µg/m3)
Cancer Risk
(risk per million)
Chronic Non-Cancer
Hazard Index
Annual PM2.5
(µg/m3)
Maximum Exposed Individual Resident (MEIR) 0.02032 4.45 0.004 0.06857 Maximum Exposed Individual Worker (MEIW) 0.02477 0.40 0.005 0.08358 The Kings Academy (Middle and High School) 0.00048 0.05 <0.001 0.00165 Maximum Exposed Individual 4.45 <0.01 0.08358
Bay Area Air District Thresholds of Significance 10 1 0.3 Exceeds Individual Source Threshold? No No No
Notes: µg/m3 = micrograms per cubic meter; DPM = diesel particulate matter; MEIR = Maximally Exposed Individual Receptor; PM2.5 = articulate matter less than 2.5 microns in diameter.

Source: FirstCarbon Solutions 2025a.

As identified in Table 4.3-5, construction of the proposed project without LUTE EIR MM 3.5.3 New Policy 2 (subsequently adopted as General Plan Policy EM-11.10 [EJ]) (Tier 3 construction equipment with diesel particulate filter) would not result in the exceedance of one of the three applicable Bay Area Air District cancer risk thresholds.

The Bay Area Air District recommends assessing the potential cumulative impacts from sources of TACs within 1,000 feet of a project. As a result, the AQ, GHG, and Energy Report includes a cumulative health risk assessment which examined the cumulative impacts of the project’s emissions and existing sources of TAC emissions within 1,000 feet of the project at the MEIR. As demonstrated in Table 4.3-6, the cumulative impacts from project construction and existing sources of TACs would not exceed the Bay Area Air District’s cumulative thresholds of significance for cancer risk and non-cancer chronic hazard and annual PM2.5 concentrations (FirstCarbon Solutions 2025a).

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-12 De Guigne Drive Residential Project Environmental Review Table 4.3-6 Summary of Cumulative Health Impacts at the Off-site MEI Source Source Name/Type Distance from
MIR (feet)
Cancer Risk
(per million)
Chronic
Hazard Index
Maximum Annual PM2.5
Concentration (µg/m3)
Project Impacts
Construction (with implementation of Tier
3 equipment and diesel particulate filter)1
Diesel Construction
Equipment 75 4.45 0.004 0.06857
Existing Roadways
Existing Roadways See footnote 5.828 0.0279 0.2532
Existing Rail/Railyards See footnote 0.4923 0 0
Permitted Stationary Sources
Facility ID 20339–Sandis (Generator) 1500 0.5 0 0
Facility ID 17728–Fry’s Electronics, Inc. 825 3.58 0 0.01 Cumulative Health Risks
Cumulative Total with Project Construction 14.8503 0.0319 0.33177 Bay Area Air District Cumulative Thresholds
of Significance 100 10 0.8
Threshold Exceedance? No No No
Notes: µg/m3 = micrograms per cubic meter; MEI = Maximally Exposed Individual; PM2.5 = particulate matter less than 2.5 microns in diameter; TAC = toxic air contaminant.
1 The construction cancer risk and chronic non-cancer hazard estimates incorporate the use of Tier 3 engines with Level 3 particulate filters for all construction equipment rated for 50 horsepower or greater, in accordance with LUTE EIR MM.

Source: Modeling performed by FirstCarbon Solutions in 2025.

Lastly, while not an impact criterion under CEQA, General Plan Policy EM-11.4 requires development projects that are located within 1,000 feet of a major pollution source and that include sensitive uses to implement BMPs (e.g., separation/setbacks, landscaping, barriers, ventilation systems, air filters/cleaners, and/or other effective measures to minimize potential impacts from air pollution)to reduce exposure to TACs or, alternatively perform a site-specific HRA. Table 4.3-7, below, demonstrates that the cumulative health impacts to the future on-site residents from existing TAC emission sources located within 1,000 feet of the project site would be below the Bay Area Air District’s cumulative thresholds for health risks (FirstCarbon Solutions 2025a).

Table 4.3-7 Summary of the Cumulative Health Impacts at the Proposed Project Site during Project Operations
Source Name/Type Cancer Risk
(per million)
Chronic
Hazard Index
Maximum Annual PM2.5
Concentration (mg/m3)
Existing Road and Rail
Existing Roadways 9.3658 0.03097 0.2321
Rail and Railyards 0 0 0
Permitted Stationary Sources of TACs
Facility ID 20339–Sandis (Generator) 0.5 0 0
Facility ID 17728–Fry’s Electronics, Inc. 3.58 0 0.01
Cumulative Total 13.446 0.03097 0.2421
Bay Area Air District Cumulative Thresholds of Significance 100 10 0.8 Threshold Exceedance? No No No
Notes: µg/m3 = micrograms per cubic meter; Bay Area Air District = Bay Area Air Quality Management District; MEI = Maximally Exposed Individual; PM2.5 = particulate matter less than 2.5 microns in diameter; TAC = toxic air contaminant.

Source: FirstCarbon Solutions 2025a.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-13 Regarding operational TAC emissions, the project proposes residential uses and would not have on-site source TACs during operation. Thus, operation of the project would not expose sensitive receptors to substantial pollutant concentrations for an extended period of time.

Therefore, with project implementation of LUTE EIR MM 3.5.3 New Policy 2 (subsequently adopted as General Plan Policy EM-11.10 [EJ]) based on the analysis above, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR concerning the exposure of sensitive receptors to substantial pollutant concentrations remain valid and no further analysis is required. e) Create objectionable odors affecting a substantial number of people? Impact 3.5.7 of the LUTE Draft EIR identified that development associated with the LUTE could create objectionable odors affecting a substantial number of people. The LUTE Draft EIR concluded that implementation of Mitigation Measure 3.5.7 would reduce this impact to less than significant.

Odorous emissions generated by heavy-duty diesel equipment and the laying of fresh asphalt during future project- related construction activities would be intermittent and temporary and would dissipate rapidly from the source with an increase in distance. Construction of the project would be implemented over a period of approximately 18 months and any potential odor-generating activities would not occur in a single location, or within proximity to off-site receptors, for an extended period. The type and level of construction activity would be typical of new residential development. Given the temporary and intermittent nature of odor-generating construction activities, construction of the project would not expose a substantial number of people to objectionable odors for an extended period.

The project does not include any long-term uses that are considered to be sources of objectionable odors (e.g., landfill, wastewater treatment plant). Operation of the project is not expected to produce any offensive odors that would result in odor complaints. During project operation, odors would primarily be generated by passenger vehicles traveling to and from the site. These occurrences would not produce objectionable odors affecting a substantial number of people. Thus, the project would not be a source of objectionable odors, the surrounding development, which consists of primarily commercial and residential uses, is not a source of objectionable odors, and there is no cumulative impact related to objectionable odors. Therefore, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR related to odors remain valid and no further analysis is required.

Mitigation Measures
The following adopted mitigation measures were identified in the LUTE EIR and are General Plan policies that are applicable to the project and were addressed in the analysis above.

Adopted LUTE EIR Mitigation Measure MM 3.5.3 Short-Term Construction Emissions (subsequently adopted as General Plan Policy EM-11.10 [EJ])
The following will be added as policies to the Environmental Management Chapter of the General Plan:
 Prior to the issuance of grading or building permits, the City of Sunnyvale shall ensure that BAAQMD basic construction mitigation measures from Table 8-1 of the BAAQMD 2011 CEQA Air Quality Guidelines (or subsequent updates) are noted on the construction documents.  In the cases where construction projects are projected to exceed the BAAQMD’s air pollutant significance thresholds for NO
X, PM10, and/or PM2.5, all off-road diesel-fueled equipment (e.g., rubber-tired dozers, graders, scrapers, excavators, asphalt paving equipment, cranes, tractors) shall be at least CARB Tier 3 Certified or better.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-14 De Guigne Drive Residential Project Environmental Review Adopted LUTE EIR Mitigation Measure MM 3.5.5 Short-Term Construction Emissions The following will be added as policies to the Environmental Management Chapter of the General Plan:
 In the case when a subsequent project’s construction span is greater than 5 acres and/or is scheduled to last more than two years, the subsequent project applicant shall be required to prepare a site -specific construction pollutant mitigation plan in consultation with Bay Area Air Quality Management District (BAAQMD) staff prior to the issuance and grading permits. A project-specific construction-related dispersion modeling acceptable to the BAAQMD shall be used to identify potential toxic air contaminant impacts, including diesel particulate matter. If BAAQMD risk threshold (i.e., probability of contracting cancer is greater than 10 in one million) would be exceeded, mitigation measures shall be identified in the construction pollutant mitigation plan to address potential impacts and shall be based on site-specific information such as the distance to the nearest sensitive receptors, project site plan details, and construction schedule. The City shall ensure construction contracts include all identified measures and that the measures reduce the health risk below BAAQMD risk thresholds.

Construction pollutant mitigation plan measures shall include but not be limited to:

1. Limiting the amount of acreage to be graded in a single day.

2. Restricting intensive equipment usage and intensive ground disturbance to hours outside of normal school hours.
 Notifying affected sensitive receptors one week prior to commencing on -site construction so that any necessary precautions (such as rescheduling or relocation of outdoor activities) can be implemented. The written notification shall include the name and telephone number of the individual empowered to manage construction of the project. In the event that complaints are received, the individual empowered to manage construction shall respond to the complaint within 24 hours. The response shall include identification of measures being taken by the project construction contractor to reduce construction-related air pollutants. Such a measure may include the relocation of equipment.

Conclusion
While project-specific analyses provide additional detail for the project site, the analysis confirms that with application of LUTE mitigation measures and/or uniformly applied development standards and policies the project would result in no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The conclusions of the LUTE EIR regarding air quality impacts remain valid and no additional analysis is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-15

4.4 BIOLOGICAL RESOURCES
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

4. Biological Resources. Would the project:
a) Have a substantial adverse effect,
either directly or through habitat
modifications, on any species
identified as a candidate,
sensitive, or special-status
species in local or regional plans,
policies, or regulations, or by the
California Department of Fish
and Wildlife or US Fish and
Wildlife Service?
Draft EIR Setting pp.

3.9-1 to 3.9-13
Impacts 3.9.1 and

3.9.5 No No No No NA, impact remains
less than significant
b) Have a substantial adverse effect
on any riparian habitat or other
sensitive natural community
identified in local or regional
plans, policies, and regulations or
by the California Department of
Fish and Game or US Fish and
Wildlife Service?
Draft EIR Setting pp.

3.9-1 to 3.9-13
Impacts 3.9.2 and

3.9.5 No No No No NA, impact remains
less than significant
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?
Draft EIR Setting pp.

3.9-1 to 3.9-13
Impacts 3.9.2 and

3.9.5 No No No No NA, impact remains
less than significant
d) Interfere substantially with the
movement of any native resident
or migratory fish and wildlife
species or with established native
resident or migratory wildlife
corridors, or impede the use of
native wildlife nursery sites?
Draft EIR Setting pp.

3.9-1 to 3.9-13
Impacts 3.9.3 and

3.9.5 No No No No NA, impact remains
less than significant
e) Conflict with any local policies or
ordinances protecting biological
resources, such as a tree
preservation policy or ordinance?
Draft EIR Setting pp.

3.9-1 to 3.9-13
Impacts 3.9.4 and

3.9.5 No No No No NA, impact remains
less than significant
f) Conflict with the provisions of an
adopted Habitat Conservation
Plan, Natural Community
Conservation Plan, or other
approved local, regional, or state
habitat conservation plan?
Draft EIR Setting pp.

3.9-1 to 3.9-13
Impacts 3.9.4 and

3.9.5 No No No No NA, impact remains
less than significant
Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-16 De Guigne Drive Residential Project Environmental Review

4.4.1 Discussion
No new information pertaining to biological resources has become available since the LUTE EIR was certified in April 2017.

A Biological Resources Assessment (BRA) was conducted for the project site in April 2024. A site visit was conducted in December 2024 to verify general site conditions and to survey for potential nesting habitat in areas adjacent to the site. Results of the BRA indicated that the project site is highly developed and that no special status plant species have the potential for occurrence within the project site and surrounding area. Three special -status wildlife species (Pallid bat [Antrozous pallidus], Swainson's hawk [Buteo swainsoni], and Hoary bat [Lasiurus cinereus]) were identified as having a low potential of occurrence in the project site and surrounding area due to the presence of surrounding trees as potential habitat. Because there is occurrence of these species near the project site, the BRA included recommendations for pre-construction nesting bird and roosting bat surveys in addition to protection recommendations in the event that raptor nests or roosting habitat is observed (e.g., established/protected construction buffers, removal of trees outside of pup season [May-August], two-step tree removal under the supervision of a qualified biologist) (Madrone Ecological Consulting 2024). The BRA and Pre-Development Assessment Arborist Report, prepared in January 2025, indicated that 113 onsite trees are within the Tree Protection Zone (Madrone Ecological Consulting 2024; Atlas Tree Service, Inc. 2025). Of the total 580 onsite trees, 269 are considered protected under the City of Sunnyvale Municipal Code Chapter 19.94. Recommendations in the BRA related to tree removal include implementation of a tree replanting plan, and compliance with avoidance and minimization measures outlined in Municipal Code Chapter 19.94 through obtaining a tree removal permit. No naturally occurring aquatic resources are present within the site (Madrone Ecological Consulting 2024). 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 Wildlife or the US Fish and Wildlife Service?
As identified in LUTE Draft EIR Impact 3.9.1, the urbanized portions of the City are largely built out and do not have large areas of natural habitat. Ruderal infill lots could support burrowing owl and Congdon’s tarplant. Urban parks, open space, and riparian areas, as well as any place with trees, could support nesting birds. Active nests of all migratory birds, including raptors, are protected by state and federal law. The LUTE EIR notes that direct impacts on special-status species could occur as a result of the construction of private development and/or public projects supporting future uses (e.g., trails). The LUTE policies and actions include protections that address natural habitat conditions in the City. Specifically, Policy 10, Action 5 requires the City to continue to evaluate and ensure mitigation of potential biological impacts of future development and redevelopment projects in a manner consistent with applicable local, state, and federal laws and regulations. The City of Sunnyvale is also required to comply with all applicable federal and state laws and regulations pertaining to species and habitat protection. This would include ensuring that nesting birds and raptors are not impacted during construction activities. Thus, the LUTE Draft EIR identified this impact as less than significant under project and cumulative (Impact 3.9.5) conditions.

The developed project site consists of office buildings, paved parking areas, and landscaped areas with trees. No natural habitat conditions exist to support special-status plant species. However, there is a low potential for the presence of migratory birds and roosting bats within the project site as a result of existing trees and buildings (Madrone Ecological Consulting 2024). Consistent with General Plan Policy LT-1.10e and standard conditions of approval, the project will be conditioned on conducting pre-construction bat and nesting bird surveys, as well as any necessary protection procedures/recommendations provided by the qualified biologist. The project is required to comply with the federal and state provisions, including the Migratory Bird Treaty Act, which constitute uniformly applied development standards, that prohibit harm to nesting birds and raptors. In addition , the project would be subject to LUTE Policy 10, Action 5 to evaluate and ensure mitigation of impacts to biological resources, including nesting birds.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-17 With the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required.
b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, or regulations or by the California Department of Fish and Wildlife or the US Fish and Wildlife Service? LUTE Draft EIR Impacts 3.9.2 and 3.9.5 addressed potential impacts to wetlands and other sensitive habitats from implementation of the LUTE. The analysis identified that subsequent projects under the LUTE are required to comply with all applicable federal and state laws and regulations pertaining to species and habitat protection in addition to LUTE policies and actions and the City’s Municipal Code. This impact was identified as less than significant under project and cumulative (Impact 3.9.5) conditions.

The developed project site consists of office buildings, paved parking areas, and landscaped areas with ornamental vegetation, including trees. No riparian habitat or other sensitive community exists on the site. The project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding biological impacts remain valid and no further analysis is required. 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?
LUTE Draft EIR Impacts 3.9.2 and 3.9.5 addressed potential impacts to wetlands from implementation of the LUTE.

The analysis identified that subsequent projects under the LUTE are required to comply with all applicable federal and state laws and regulations pertaining to species and habitat protection in addition to LUTE policies and actions and the City’s Municipal Code. This impact was identified as less than significant under project and cumulative (Impact

3.9.5) conditions.

As identified above, the project site contains no aquatic resources. The proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding wetlands and waters of the United States remain valid and no further analysis is required. 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?
LUTE Draft EIR Impacts 3.9.3 and 3.9.5 identified no significant impacts to wildlife movement, as planned development of the City under the LUTE would occur in existing developed areas of Sunnyvale and would not extend into wetlands and open space areas along San Francisco Bay that provide habitat and movement corridors for wildlife species in the region. In addition, creek and waterway corridors in the City (i.e., Stevens Creek, Calabazas Creek, and Moffett Channel) would be retained in their current condition under the LUTE. This impact was identified as less than significant under project and cumulative (Impact 3.9.5) conditions.

The project site is located in an existing developed area that is surrounded by parcels developed with urban uses and contains no wildlife movement corridors, including no wetlands and open spaces, creeks or waterway corridors, or native wildlife nursery sites. The proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-18 De Guigne Drive Residential Project Environmental Review substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding migratory fish and wildlife movement and use of native wildlife nursery sites remain valid and no further analysis is required. e) Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance?
As identified in Impact 3.9.4 of the LUTE Draft EIR, the LUTE includes policies that support the objectives of the San Francisco Bay Plan and would comply with the City’s tree protection provisions in Sunnyvale Municipal Code Chapter

19.94 through obtaining a tree removal permit. Thus, no significant impacts were identified.

The proposed project would involve removal of up to 580 onsite trees, 226 of which are protected under City Code

19.94,. The City’s tree replacement requirements would include a minimum of two 24-inch box trees to be planted on site for protected tree removal. The project includes planting of 157 trees, representing a tree replacement balance of 548 trees. Because of this, the project applicant would be required to pay tree replacement in-lieu fee, consistent with City of Sunnyvale Municipal Code Section 19.94.080(b) (Appendix A). As stated in Municipal Code 19.94.080(b), replacement tree fees could result in new trees in parks or other public areas of the C ity. Because the project applicant would adhere to the City’s tree replacement requirements in the form of onsite replanting and payment of in-lieu fees, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding consistency with local policies and ordinances protecting biological resources remain valid and no further analysis is required.
f) Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan?
Sunnyvale is not located in a habitat conservation plan area. As a result, the LUTE Draft EIR determined that no conflict with an adopted habitat conservation plan would occur and no impact would result . Therefore, no significant impact was identified under project or cumulative conditions. No new conservation plans have been adopted since approval of the LUTE. Therefore, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR concerning conflicts with adopted conservation plans remain valid and no further analysis is required.

Mitigation Measures
No significant biological resource impacts were identified in the LUTE EIR, and no additional mitigation measures would be required for the proposed project.

Conclusion
With the application of uniformly applied development standards and policies, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding biological resources remain valid and no further analysis is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-19

4.5 CULTURAL RESOURCES
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation.

Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

5. Cultural Resources. Would the project:
a) Cause a substantial adverse
change in the significance of a
historical resource as defined in
Section 15064.5?
Draft EIR Setting pp.

3.10-1 to 3.10-11
Impacts 3.10.1 and

3.10.3 No No No No NA, but impact
remains significant and
unavoidable. Project
would not contribute
to this impact
b) Cause a substantial adverse
change in the significance of an
archaeological resource
pursuant to Section 15064.5?
Draft EIR Setting pp.

3.10-1 to 3.10-11
Impact 3.10.2
No No No No NA, impacts would
remain less than
significant
c) Disturb any human remains,
including those interred outside
the formal cemeteries?
Draft EIR Setting pp.

3.10-1 to 3.10-11
Impact 3.10.2
No No No No NA, impacts would
remain less than
significant

4.5.1 Discussion
No new information pertaining to cultural resources has become available since the LUTE EIR was certified in April 2017.

An Archaeological Due Diligence Literature Review (Archaeological Review) was prepared for the project in April 2025 and California Historical Resources Information System (CHRIS) records search request results were received from the Northwest Information Center in December 2024 (Basin 2025, CHRIS 2024). Results of the CHRIS records search results indicated that no recorded cultural resources were identified within the project area or within a 0.25 -mile radius of the project site (CHRIS 2024). Results of the Archaeological Review indicated that no known pre-historic, historic-era, or historic built-environment features or structures were identified within the project site or adjacent areas. Further, the project area was noted as having a low archaeological sensitivity for both prehistoric and historic- era resources (Basin 2025).

Refer to Section 4.18, below, for a discussion of tribal cultural resources. a) Cause a substantial adverse change in the significance of a historical resource as defined in Section 15064.5?
Impact 3.10.1 of the LUTE Draft EIR identified that the City contains numerous buildings that have historical value associated with previous industrial and military-related industries and that subsequent actions under the LUTE have the potential to directly (i.e., demolition) or indirectly (i.e., adverse effects to historical setting from adjacent construction) impact historic buildings and structures that qualify as historic resources under CEQ A. The Community Character chapter of the Sunnyvale General Plan includes various policies addressing this issue. Policy CC-5.1 states that the City will preserve existing landmarks and cultural resources and their environmental settings, Policy CC-5.3 seeks to identify and work to resolve conflicts between the preservation of historic resources and alternative land uses, and Policy CC-5.4 states that the City will seek out, catalog, and evaluate heritage resources that may be significant. The LUTE EIR concluded that implementation of the LUTE would result in significant and unavoidable impacts under project and cumulative (Impact 3.10.3) conditions.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-20 De Guigne Drive Residential Project Environmental Review As described above, the project site does not contain any known historic resources (Basin 2025). Therefore, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off - site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding historical resources remain valid and no further analysis is required. b) Cause a substantial adverse change in the significance of an archaeological resource pursuant to Section 15064.5?
Impact 3.10.2 of the LUTE Draft EIR noted that implementation of the LUTE could impact buried archaeological resources during construction activities. The LUTE Draft EIR concluded that implementation of Policy 10 Action 6 (now Policy LT-1.10f), quoted below, would ensure that impacts to archaeological resources and human remains (in combination with Health and Safety Code Section 7050.5[b]) are reduced to a less-than-significant level under project and cumulative (Impact 3.10.3) conditions.

LT-1.10f: Continue to condition projects to halt all ground-disturbing activities when unusual amounts of shell or bone, isolated artifacts, or other similar features are discovered. Retain an archaeologist to determine the significance of the discovery. Mitigation of discovered significant cultural resources shall be consistent with Public Resources Code Section 21083.2 to ensure protection of the resource.

The project site and surrounding area does not include any known archaeological resources or human remains, and the project site was noted as having a low potential for unrecorded archaeological resources (Basin 2025). The proposed project would be required to comply with General Plan Policy LT-1.10f, which would require any project activities to halt in the event that amounts of shell or bone, isolated artifacts, or other similar features are discovered during construction. This policy would also require a qualified archaeologist to assess the significance of any discoveries to ensure protection of potential resources. Therefore, with the application of uniformly applied development standards and policies, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding historical and archaeological resources remain valid and no further analysis is required. c) Disturb any human remains, including those interred outside of formal cemeteries? See analysis in item b) above. In addition, projects must comply with state laws that protect human remains, including Health and Safety Code Section 7050.5 and Public Resources Code Section 5097.98, which protect human remains from adverse impacts.

Mitigation Measures
No mitigation measures pertaining to cultural resources were identified in the certified LUTE EIR, and no additional mitigation measures are required for the proposed project.

Conclusion
With the application of uniformly applied development standards and policies, t he proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding cultural resources remain valid and no further analysis is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-21

4.6 ENERGY
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any
Peculiar
Impact?
Any Impact
Not
Analyzed as
Significant
Effect in
LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

6. Energy. Would the project:
a) Result in potentially significant
environmental impact due to wasteful,
inefficient, or unnecessary consumption
of energy resources, during project
construction or operation?
Draft EIR Setting
pp. 3.11-30 to

3.11-31
Impact 3.11.4.1
No No No No NA, impact remains
less than significant
b) Conflict with or obstruct a state or local
plan for renewable energy or energy
efficiency?
Draft EIR Setting
pp. 3.5-18 and

3.11-32
Impact 3.13.1
Final EIR pp. 3.0-5
to 3.0-6
No No No No NA, impact remains
less than significant

4.6.1 Discussion
Since completion of the LUTE EIR, the City of Sunnyvale and the cities of Campbell, Cupertino, Gilroy, Los Altos, Los Altos Hills, Los Gatos, Milpitas, Monte Sereno, Morgan Hill, Mountain View, and Saratoga, and unincorporated Santa Clara County became members of Silicon Valley Clean Energy (SVCE), which serves as the Community Choice Aggregation for its member communities. SVCE works in partnership with the Pacific Gas and Electric Company (PG&E) to deliver direct, renewable electricity to customers within its member jurisdictions. Consistent with s tate law, all electricity accounts in Sunnyvale were automatically enrolled in SVCE; however, customers can choose to opt out or remain with PG&E. With the creation of SVCE in 2017 to increase renewable energy use , 97 percent of homes and businesses in Sunnyvale receive carbon-free electricity, primarily from SVCE. A small number of residents and businesses still source their electricity from PG&E (City of Sunnyvale 2024). Electricity is supplied to the City using infrastructure built and maintained by PG&E. An energy analysis was completed for the project as part of the AQ, GHG, and Energy Report prepared by FirstCarbon Solutions (FirstCarbon Solutions 202 5a). The results of this analysis are summarized below.
a) Result in potentially significant environmental impact due to wasteful, inefficient, or unnecessary consumption of energy resources, during project construction or operation?
As described in Impact 3.11.4.1 of the LUTE EIR, implementation of the LUTE would increase the consumption of energy. However, subsequent development would comply with Building Energy Efficiency Standards included in Title 24 of the California Code of Regulations and implement the energy efficiency requirements of the City’s Climate Action Plan. This would include obtaining carbon-free electricity from SVCE. Implementation of the LUTE would also result in an improvement in VMT per capita as compared to citywide level of service (LOS) under the previous General Plan. This impact was identified as less than significant under project and cumulative conditions.

Diesel fuel would primarily be consumed during the project construction period through use of heavy equipment, off-road trucks, and on-road haul trucks, while gasoline consumption would primarily be associated with worker commute trips. As identified in the AQ, GHG, and Energy Report, construction of the project would result in the consumption of approximately 58,773 gallons of diesel fuel and 75,702 gallons of gasoline (FirstCarbon Solutions 2025a). Construction contractors typically attempt to maximize efficiency in terms of equipment and fuel use to avoid Attachment 6

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City of Sunnyvale
4-22 De Guigne Drive Residential Project Environmental Review unnecessary additional costs. Additionally, the project involves a relatively short construction period (i.e., 18 months) after which construction-related energy consumption would cease. Therefore, it is not anticipated that construction of the project would result in wasteful, inefficient, and unnecessary construction of energy.

During operation, the project would result in electricity consumption to power appliances, lighting, and building utilities (e.g., water heaters and heating and air conditioning systems) and landscaping and maintenance activities.

Gasoline, compressed natural gas, and diesel fuel would be during passenger vehicle trips to and from the project site. The project would be all-electric and would not include any natural gas utility connections. The project would be required to comply with Title 24 requirements as well as the City’s Playbook and associated code requirements, as shown in Table 4.6-1, below.

Table 4.6-1 Project Consistent with the City of Sunnyvale Climate Action Playbook Update/Game Plan 2028 Strategies and Play Project Consistency
Strategy 1: Promoting Clean Electricity. Consistent. The proposed project would include installation of solar photovoltaic (PV) panels consistent with the 2022 Energy Code 150.1(c)(14) or applicable updates.

Play 1.1: Promoting 100 clean energy with 100 clean
energy participation by 2030.

Consistent. Silicon Valley Clean Energy (SVCE) delivers 100 carbon-free electricity. As a result, the proposed project would operate on clean energy at initiation. Customers are automatically enrolled in SVCE’s electric generation service. Should the residents opt out of SVCE, which is beyond the project applicant’s control, they would receive electricity generation from Pacific Gas and Electric Company (PG&E), which does not deliver 100 carbon-free electricity. However, Senate Bill (SB) 100 requires that renewable energy and zero-carbon resources supply 100 percent of electric retail sales by 2045, with SB 1020 furthering these objectives by mandating 100 percent renewable and zero-carbon energy resources by December 31, 2045. Therefore, those residents’ electricity would still come from increasingly renewable sources and entirely from renewable energy and zero-carbon resources by 2045.

Play 1.2: Increase local solar photovoltaics with 3 of
load from local solar by 2030 and 5 by 2045.

Consistent. The proposed project would include installation of solar PV panels consistent with the 2022 Energy Code 150.1(c)(14) or applicable updates.

Continue to enforce the solar panel requirements of
the new building Reach Codes and Moffett Park
Specific Plan policies to increase solar energy
generation and storage in Moffett Park and
throughout the community.

Strategy 2: Decarbonizing Buildings. Consistent. The proposed project would be all electric in design, without natural gas plumbing, and electricity is or would be decarbonized.

Play 2.3: Achieve all-electric new construction with
100 all-electric new buildings by 2030.

Consistent. The proposed project would be all electric in design, without natural gas plumbing.

Strategy 3: Decarbonizing Transportation and
Sustainable Land Use.

Consistent. The proposed project is in close proximity to the bus stops serving several bus routes (along Stewart Drive south of the site and Duane Avenue 500 feet north of the site). Bus stop proximity would promote public transit use, leading to reduced greenhouse gas (GHG) emissions.

Play 3.2: Increase transportation options and
support shared mobility to reduce vehicle miles per
person by 20 by 2030 and 25 by 2045.

Consistent. The proposed project would include dedicated bike parking to encourage bike transportation per City of Sunnyvale requirements for new development.

Additionally, the proposed project is in close proximity to several bus stop within walking distance.

Play 3.3: Increase Zero-Emission Vehicles (ZEVs) with
42 of all vehicles on the road being ZEVs by 2030
and 90 by 2045.

Consistent. The proposed project would include EV parking infrastructure consistent with the City’s Reach Code. These project features would promote the adoption of ZEVs by providing infrastructure to facilitate their use.

Strategy 4: Managing Resources Sustainably.

Consistent. The proposed project would include installation of new on -site trees in the landscaping, which would enhance natural carbon sequestration at the site, aligning with the City’s Urban Forest Management Plan and benefiting stormwater infiltration capacity.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-23 Strategies and Play Project Consistency
Play 4.1: Achieve zero waste goals of reducing
landfilled garbage to 1 pound (lb) per person per
day and achieve 75 diversion of landfilled organics
by 2030 and <1 lb per day and achieve 75 diversion
of landfilled organics by 2045
Consistent. The proposed project would not conflict with implementation of the City’s Zero Waste Strategic Plan and the entire project would be served by municipal waste companies that must comply with SB 1383, which set Statewide targets to reduce organic waste disposed of in landfills of 75 by 2025.

Play 4.2: Ensure resilience of water supply. Consistent. This proposed project would comply with all water conservation requirements.

Play 4.3: Enhance natural carbon sequestration
capacity.

Consistent. The landscape design for this proposed project would incorporate new trees and shrubs to support carbon sequestration and reduce urban heat island effect.

Source: FirstCarbon Solutions 2025a.

It is estimated that vehicle fuel consumption per year of project operation would be approximately 185,528 gallons of gasoline, 18,296 gallons of diesel fuel, 892 gallons of compressed natural gas, and 135,575 kWh of electricity per year of operation. The project is in close proximity to existing bus stops serving several bus routes (along Stewart Drive south of the site and Duane Avenue 500 feet north of the site). Bus stop proximity would promote public transit use and reduce transportation-related fossil fuel consumption. Additionally, the project would promote EV use through the inclusion of EV charging infrastructure consistent with the City’s Reach Code.

The project would consume 3,148,973 kWh of electricity and no natural gas. The project would source its electricity from SVCE, the area’s electricity provider, which delivers 100 percent carbon-free electricity. The project would also include solar photovoltaic (PV) panels as part of project design.

For these reasons, the project’s construction and operational energy consumption would not be wasteful, inefficient, or unnecessary. Therefore, with the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR pertaining to energy consumption remain valid and no further analysis is required. b) Conflict with or obstruct a state or local plan for renewable energy or energy efficiency?
The project would not conflict with or obstruct a state or local plan for renewable energy or energy efficiency. The project would be consistent with the Energy Code and the City’s Playbook as identified in Table 4.6-1 in item a) above (FirstCarbon Solutions 2025a). The project also is infill development near transit, which is the type of development that is consistent with state goals to reduce passenger vehicle and related energy use.

Mitigation Measures
No mitigation measures were identified in the certified LUTE EIR regarding energy, nor are any additional mitigation measures required for the project.

Conclusion
No new circumstances or project changes have occurred nor has any new information been identified requiring new analysis or verification. Therefore, with the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The conclusions of the LUTE EIR pertaining to energy remain valid and no further analysis is required.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-24 De Guigne Drive Residential Project Environmental Review

4.7 GEOLOGY AND SOILS
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any
Peculiar
Impact?
Any Impact
Not
Analyzed as
Significant
Effect in
LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

7. Geology and Soils. Would the project:
a) Directly or indirectly cause substantial
adverse effects, including the risk of
loss, injury, or death involving:
i) Rupture of a known earthquake
fault, as delineated on the most
recent Alquist-Priolo Earthquake
Fault Zoning Map issued by the
State Geologist for the area or
based on other substantial
evidence of a known fault? Refer
to Division of Mines and Geology
Special Publication 42.
ii) Strong seismic ground shaking?
iii) Seismic-related ground failure,
including liquefaction?
iv) Landslides?
Draft EIR Setting
pp. 3.7-1 to 3.7-13
Impact 3.7.1 and
Impact 3.7.5
No No No No NA, impact remains
less than significant
b) Result in substantial soil erosion or the
loss of topsoil?
Draft EIR Setting
pp. 3.7-1 to 3.7-13
Impacts 3.7.2 and

3.7.5 No No No No NA, impact remains
less than significant
c) Be located on a geologic unit or soil
that is unstable, or that would become
unstable as a result of the project, and
potentially result in on- or off-site
landslide, lateral spreading, subsidence,
liquefaction, or collapse?
Draft EIR Setting
pp. 3.7-1 to 3.7-13
Impacts 3.7.3 and

3.7.5 No No No No NA, impact remains
less than significant
d) Be located on expansive soil, as defined
in Table 18-1-B of the Uniform Building
Code (1994), creating substantial risks to
life or property?
Draft EIR Setting
pp. 3.7-1 to 3.7-13
Impact 3.7.3
No No No No NA, impact remains
less than significant
e) Have soils incapable of adequately
supporting the use of septic tanks or
alternative waste water disposal systems
where sewers are not available for the
disposal of waste water?
Scoped out in
Draft EIR on page

3.7-14
No No No No NA
f) Directly or indirectly destroy a unique
paleontological resource or site or
unique geologic feature?
Draft EIR Setting
pp. 3.7-1 to 3.7-13
Impacts 3.7.4 and

3.10.3 No No No No NA, impact remains
less than significant
Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-25

4.7.1 Discussion
No substantial change in the environmental and regulatory settings related to geology and soils, described in LUTE Draft EIR Section 3.7, “Geology, Soils, and Paleontological Resources,” has occurred since certification of the LUTE EIR.

The regional and local settings remain the same as stated in Section 3.7 of the LUTE Draft EIR.

Since preparation of the LUTE Draft EIR, a California Supreme Court decision (California Building Industry Association v. Bay Area Air Quality Management District [2015] 62 Cal.4th 369, 377) clarified CEQA with regard to the effects of existing environmental conditions on a project’s future users or residents. The effects of the environment on a project are generally outside the scope of CEQA unless the project would exacerbate these conditions. Changes to the CEQA Guidelines to reflect this decision are in process by the State but have not been adopted. Local agencies are not precluded from considering the impact of locating new development in areas subject to existing environmental hazards. However, CEQA cannot be used by a lead agency to require a developer or other agency to obtain an EIR or implement mitigation measures solely because the occupants or users of a new project would be subjected to the level of hazards specified. However, previous discussions of effects of the environment related to geology and soils is included herein for disclosure purposes.
a) Directly or indirectly cause substantial adverse effects, including the risk of loss, injury, or death involving:
i) Rupture of a known earthquake fault, as delineated on the most recent Alquist- Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? (Refer to California Geological Survey Special Publication 42.);
ii) Strong seismic ground shaking;
iii) Seismic-related ground failure, including liquefaction; and iv) Landslides?
As discussed in Impact 3.7.1 and 3.7.5 of the LUTE Draft EIR, the City has adopted the California Building Code (CBC) by reference in Municipal Code Section 16.16.020, with changes and modifications providing a higher standard of protection. All new development and redevelopment would be required to comply with the current adopted CBC, which includes design criteria for seismic loading and other geologic hazards. Compliance with the CBC requires that new developments incorporate design criteria for geologically induced loading that governs sizing of structural members and provides calculation methods to assist in the design process. While ground shaking could result in damage to structures, incorporation of CBC criteria that recognize this potential would lessen those impacts. The CBC includes provisions for buildings to structurally survive an earthquake without collapsing and includes specific measures such as anchoring structures to the foundation and structural frame design. The LUTE EIR concludes that impacts related to landslides would be less than significant under project and cumulative conditions.

A Draft Geotechnical Investigation was prepared for the project in 2024. The project site is not within an Alquist- Priolo earthquake fault zone. The nearest fault segment, the Monte-Vista-Shannon fault, is located approximately 5.5. miles west, whereas other major fault zones, including the Hayward and San Andreas faults are located approximately 8 miles northeast and 9 miles southwest of the project site, respectively. While the project site is mapped within potential liquefaction zone, Cone Penetration Tests and a liquefaction analysis conducted as part of the geotechnical investigation indicate that thick, non-liquefiable subsurface soils overlay thin, potentially liquefiable soils within the site. As a result, the potential liquefaction within the site was considered low. Similarly, the potential for onsite lateral spreading was considered very low. The project site is located in a developed, flat area within the City; the site is not located within any mapped landslide zones (Rockridge Geotechnical 2024).

The proposed project would be subject to CBC and Sunnyvale Municipal Code provisions for geologic stability. The project applicant’s Draft Geotechnical Investigation (Rockridge Geotechnical 2024) addresses project-specific geologic and seismic stability conditions, as described above. The final project design would incorporate foundation Attachment 6

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4-26 De Guigne Drive Residential Project Environmental Review and seismic recommendations as necessary, which would safeguard against significant damage to structures that could result from seismic activity. With the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding geologic hazards remain valid.
b) Result in substantial soil erosion or the loss of topsoil? As identified in Impact 3.7.2 of the LUTE Draft EIR, implementation of the LUTE would allow for new development, redevelopment, and infrastructure improvements. Grading and site preparation activities associated with such development could temporarily remove buildings and pavement, which could expose the underlying soils to wind and water erosion. Ground-disturbing activities would be required to comply with CBC Chapter 70 standards, which would ensure implementation of appropriate site-specific measures during grading activities to reduce and control soil erosion. Additionally, any development involving clearing, grading, or excavation that causes soil disturbance of one or more acres would be required to prepare and comply with a stormwater pollution prevention plan (SWPPP), which includes a schedule for the implementation and maintenance of erosion control measures and a description of the erosion control practices, including appropriate design details and a time schedule. The SWPPP would consider the full range of erosion control BMPs, including any additional site-specific and seasonal conditions. As further discussed in LUTE Draft EIR Section 3.8, “Hydrology and Water Quality,” the State Water Resources Control Board has adopted a Construction General Permit (Order No. 20090009-DWQ, as amended by Order No. 2010-0014-DWQ and Order 2012-0006-DWQ) that provides additional standards and requirements to avoid soil erosion. In addition, the City’s grading standards (Municipal Code Section 18.12.110) specify that when grading will create a nuisance or hazard to other properties, public way, or public facilities due to erosion from storm runoff or rainfall, grading cannot commence or continue without specific consent in writing from the Director of Public Works or the Director of Community Development. The grading standards also regulate gradients for cut -and-fill slopes. The LUTE EIR concluded that impacts from soil erosion and loss of topsoil would be less than significant under both project and cumulative (Impact 3.7.5) conditions.

The project is subject to the above standards, including the requirement to prepare and comply with the SWPPP and Construction General Permit. With the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off- site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding loss of topsoil and erosion remain valid. c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction, or collapse?
The LUTE Draft EIR indicated that future structures and improvements developed in the City under the LUTE could experience stresses on various sections of foundations and connected utilities, as well as structural failure and damage to infrastructure if located on expansive or unstable soils (Impact 3.7.3). Pursuant to Sunnyvale Municipal Code Section 18.20.100 the City requires preparation of geotechnical reports for all development projects, which include soil sampling and laboratory testing to determine the soil’s susceptibility to expansion and differential settlement and would provide recommendations for design and construction methods to reduce potential impacts, as necessary. The LUTE EIR concluded that impacts from geologic instability would be less than significant under both project and cumulative (Impact 3.7.5) conditions.

The CBC includes common engineering practices requiring special design and construction methods to reduce potential expansive soil and settlement-related impacts. Preparation of final geotechnical reports and required compliance with CBC regulations would ensure the adequate design and construction of the building foundations, and ground preparation to resist soil movement. Adherence to the City’s Municipal Code and the CBC would reduce Attachment 6

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City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-27 potential impacts associated with development on unstable soils to a less- than-significant level for the LUTE under project and cumulative conditions.

The proposed project is subject to the above standards and includes soil stability and erosion controls on project plans. The project applicant has submitted a geotechnical report (Rockridge Geotechnical 2024) that addresses project-specific geologic and soil stability issues. The project would not cause a geologic unit or soil to become unstable and with the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding geologic and soil stability remain valid.
d) Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994, as updated), creating substantial risks to life or property? See analysis under item c) above.
e) Have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water?
As described in the LUTE EIR, development in Sunnyvale would use the City’s existing wastewater conveyance and treatment systems. Septic systems or alternative wastewater disposal systems are not proposed or required as part of the proposed project; therefore, no impact under project or cumulative conditions would occur. The project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding waste disposal systems where sewers are not available remain valid and no further analysis is required. f) Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature?
Impact 3.7.4 of the LUTE Draft EIR noted that implementation of the LUTE could impact undiscovered paleontological resources during construction activities. The LUTE Draft EIR concluded that implementation of Policy 10 Action 6 (now Policy LT-1.10f), as identified below, would ensure that impacts to paleontological resources are reduced to a less - than-significant level under project and cumulative (Impact 3.10.3) conditions.

LT-1.10f: Continue to condition projects to halt all ground-disturbing activities when unusual amounts of shell or bone, isolated artifacts, or other similar features are discovered. Retain an archaeologist to determine the significance of the discovery. Mitigation of discovered significant cultural resources shall be consistent with Public Resources Code Section 21083.2 to ensure protection of the resource.

According to the LUTE EIR, the above policy is intended to result in halting work when a paleontological resource may be encountered. The project area does not include any known paleontological resources , and the project would be required to comply with General Plan Policy LT-1.10f as a condition of approval. Therefore, with the application of uniformly applied development standards and policies, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding paleontological and unique geologic features remain valid and no further analysis is required.

Mitigation Measures
No significant geologic impacts were identified in the LUTE EIR, and no mitigation measures were required.

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4-28 De Guigne Drive Residential Project Environmental Review Conclusion
With the application of uniformly applied development standards and policies, t he proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the conclusions of the LUTE EIR regarding geology and soils remain valid and no additional analysis is required.

Attachment 6

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City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-29

4.8 GREENHOUSE GAS EMISSIONS
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact Not
Analyzed as
Significant Effect
in LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based
on Substantial
New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

8. Greenhouse Gas Emissions. Would the project:
a) Generate greenhouse gas
emissions, either directly or
indirectly, that may have a
significant impact on the
environment?
Draft EIR Setting pp.

3.13-1 to 3.13-9
Impact 3.13.1
Final EIR pp. 3.0-5 to

3.0-6
No No No No NA, impact remains
less than significant
b) Conflict with an applicable
plan, policy, or regulation
adopted for the purpose of
reducing the emissions of
greenhouse gases?
Draft EIR Setting pp.

3.13-1 to 3.13-9
Impact 3.13.1
Final EIR pp. 3.0-5 to

3.0-6
No No No No NA, impact remains
less than significant

4.8.1 Discussion
On August 13, 2019, the City adopted the Climate Action Playbook (Playbook) , which builds upon the City’s previous Climate Action Plan (CAP 1.0) in 2014. Through implementation of measures in CAP 1.0, the City experienced a 12 percent decrease below 1990 emissions levels in 2016. In 2016, the City emitted 880,000 million metric tons of carbon dioxide equivalent. To demonstrate compliance with the state’s long-term climate change reduction goals, the City must achieve an interim target of a 56 percent reduction below 1990 levels by 2030 (SB 32) with the goal of meeting the state’s target of 80 percent below 1990 emissions by 2050 (Executive Order [EO] S-3-05).

Since the adoption of the LUTE EIR, there have been several new or updated greenhouse gas (GHG) executive orders, plans, policies, or regulations issued that include the following:
 EO B-55-18: This executive order, signed September 10, 2018, sets a goal “to achieve carbon neutrality as soon as possible, and no later than 2045, and achieve and maintain net negative emissions thereafter.”  Scoping Plan Update: EO B-30-15 and SB 32 require the California Air Resources Board (CARB) to prepare another update to the Scoping Plan to address the 2030 target for the state. On December 24, 2017, CARB approved the 2017 Climate Change Scoping Plan Update, which outlines potential regulations and programs, including strategies consistent with Assembly Bill (AB) 197 requirements, to achieve the 2030 target.  2017 Update to the SB 375 Targets: Under SB 375, CARB is required to update the emission reduction targets for the metropolitan planning organizations every 8 years. CARB adopted the updated targets and methodology in March 2018. Subsequent sustainable community strategies adopted after this date are subject to these new targets.  SB 100: SB 100 raises California’s Renewables Portfolio Standard requirements to 60 percent by 2030, with interim targets, and 100 percent by 2045. The bill also establishes a state policy that eligible renewable energy resources and zero-carbon resources supply 100 percent of all retail sales of electricity to California end -use customers and 100 percent of electricity procured to serve all state agencies by December 31, 2045. Under the bill, the state cannot increase carbon emissions elsewhere in the western grid or allow resource shuffling to achieve the 100 percent carbon free electricity target.
 SB 1020: SB 1020 builds on SB 100. With SB 1020, eligible renewable energy resources and zero -carbon resources must supply 90 percent of all retail sales of electricity to California end-use customers by December 31, 2035, 95% of all retail sales of electricity to California end-use customers by December 31, 2040, 100% of all retail sales Attachment 6

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4-30 De Guigne Drive Residential Project Environmental Review of electricity to California end-use customers by December 31, 2045, and 100% of electricity procured to serve all state agencies by December 31, 2035.
 Building Energy Efficiency Standards: Energy conservation standards for new residential and nonresidential buildings were adopted by the California Energy Resources Conservation and Development Commission (now the California Energy Commission) in June 1977 and most recently revised in 2016 (Title 24, Part 6, of the California Code of Regulations). Title 24 requires the design of building shells and building components to conserve energy. The standards are updated periodically to allow for consideration and possible incorporation of new energy efficiency technologies and methods. The 2019 Building Energy Efficiency Standards, which were adopted on May 9, 2018, went into effect starting January 1, 2020. The 2022 Building Energy Efficiency Standards went into effect on January 1, 2023, and will result in more energy efficiency buildings than the 2019 standards.  CALGreen Updates: CALGreen established planning and design standards for sustainable site development, energy efficiency (in excess of the California Energy Code requirements), water conservation, material conservation, and internal air contaminants. The recently adopted 2019 standards went into effect on January 1, 2020. Each iteration of the CALGreen standards improves the energy efficiency and sustainability of new development from the prior iteration. The next iteration will go into effect on January 1, 2023. Discussed below, AB 130 freezes the residential building code, including the CALGreen Code, until 2031; however, the requirements of the 2025 nonresidential CALGreen Code will be applied to new nonresidential development effective January 1, 2026.  AB 130: On June 30, 2025, the Governor signed AB 130, which institutes a six -year freeze on updates to state and local residential building standards, through 2031, with exceptions only for emergency measures, energy/fire safety, accessibility, and wildland-urban code updates. During this period, local jurisdictions may not adopt new residential building code amendments unless they are confirmed by the Building Standards Commission as emergency or health-and-safety necessities. The law also guarantees that model-home building standards remain locked in for up to 10 years or until the design significantly changes, ensuring long- term planning stability and guarding builders against sudden code shifts. Overall, the exact level of energy efficiency and allowed on- site natural gas associated with future versions of the California Energy Code are unknown at this time because the specific requirements of such future code versions are not known; therefore, emissions from building energy consumption in 2035 may be overestimated.
 SB 743: Requires transportation CEQA impacts to no longer consider congestion but instead focus on the impacts of VMT. The OPR technical advisory explains that this criterion is consistent with Public Resources Code Section 21099, which states that the criteria for determining significance must “promote the reduction in greenhouse gas emission” (Governor’s Office of Planning and Research 2018). This metric is intended to replace the use of delay and level of service to measure transportation-related impacts.  SAFE Rule: Part One of the Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule revokes a waiver granted by the US Environmental Protection Agency (EPA) to the State of California under Section 209 of the federal Clean Air Act to enforce more stringent emission standards for motor vehicles than those required by EPA for the explicit purpose of GHG emission reduction, and indirectly, criteria air pollutant and ozone precursor emission reduction.

On March 31, 2020, Part Two of the SAFE Rule was published and would amend existing Corporate Average Fuel Economy (CAFE) and tailpipe carbon dioxide emissions standards for passenger cars and light trucks and establish new standards covering model years 2021 through 2026. On December 21, 2021, the National Highway Traffic Safety Administration published its CAFE Preemption rule, which finalizes its repeal of 2019’s SAFE Rule and reopens pathways for state and local fuel economy laws.  Public Law No. 119-15: On June 12, 2025, Public Law 119-15, enacting House Joint Resolution 87, was signed into law. The law utilized the Congressional Review Act to disapprove EPA’s rule that had granted California a waiver to enforce stricter emissions standards for heavy-duty vehicles under the Clean Air Act. The disapproved rule included programs such as the Advanced Clean Trucks regulation and zero -emission requirements for airport shuttles. Passed under the Congressional Review Act, the law prevents EPA from implementing or reissuing the same or similar rules without new congressional authorization. This effectively blocks California, and other states that follow its standards, from enforcing these specific vehicle emission and warranty regulations. However, the Attachment 6

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De Guigne Drive Residential Project Environmental Review 4-31 implications of this federal law on the State’s capability to enforce its independent heavy-duty vehicle emissions standards are uncertain at this time, as the California Attorney General filed a lawsuit challenging P.L. No. 119- 15 on June 12, 2025. Whether this action will be successful is unknown, as is the possibility that a federal judge will issue a stay to halt the implementation of the heavy-duty vehicle regulations during the legal process.  Public Law No. 119-16: On June 12, 2025, Public Law No. 119-16, enacting House Joint Resolution 88, became law.

The law also relied on the Congressional Review Act to disapprove the EPA’s December 2024 waiver under the CAA that allowed California to implement and enforce the Advanced Clean Cars II (ACC II) regulation. ACC II included a zero-emission vehicle (ZEV) mandate targeting 100 percent new light-duty ZEV sales by 2035. The implications of this law on the State’s capability to enforce its independent fuel economy standards are uncertain at this time, as the California Attorney General filed a lawsuit challenging P.L. No. 119 -16 on June 12, 2025.

Whether this action will be successful is unknown, as is the possibility that a federal judge will issue a stay to halt the implementation of the ACC II regulation during the legal process. Notably, the LUTE EIR was drafted and adopted prior to the introduction of the ACC II regulation and thus would not have accounted for any emissions reductions associated with the regulation.
 Public Law No. 119-17: Public Law 119–17, enacted on June 12, 2025, disapproves, under the Congressional Review Act, the EPA’s rule titled “California State Motor Vehicle and Engine and Nonroad Engine Pollution Control Standards; The ‘Omnibus’ Low NOX Regulation; Waiver of Preemption; Notice of Decision.” The law disapproves the EPA’s January 6, 2025, Low-NOₓ rule that would have granted California a waiver to enforce stricter emissions standards for both on-road and non-road heavy-duty engines. Similar to the other CRA resolutions listed above targeting emissions waivers, this law prohibits the EPA from reissuing the same or substantially similar rule without new authorization from Congress. The law effectively blocks California, and any states following it s standards, from implementing this omnibus Low-NO
X regulatory package. Again, the implications of this federal law on the State’s capability to enforce its independent Low NOX regulatory package are uncertain at this time, as the California Attorney General filed a lawsuit challenging P.L. No. 119-17 on June 12, 2025. Whether this action will be successful is unknown, as is the possibility that a federal judge will issue a stay to halt the implementation of the Low NO
X regulatory package during the legal process. Notably, the LUTE EIR was drafted and adopted prior to the introduction of the Low-NOx rule and thus would not have accounted for any potential emissions reductions associated with the rule.

The plan-level thresholds of significance in the 2022 BAAQMD (now known as the Bay Area Air District) CEQA Guidelines were developed to assist lead agencies with determining significance for long- range local and regional plans. Local long-range plans are discretionary, program-level planning activities, such as general plans and general plan elements, specific plans, area plans, community plans, congestion management plans, and annexations of lands and service areas. Pursuant to CEQA Section 15064.7 (b)(c), a lead agency may adopt its own significance thresholds to evaluate environmental impacts. Thus, this analysis utilizes the Bay Area Air District’s plan-level thresholds to evaluate impacts related to energy from the implementation of the VCMP. The 2022 CEQA Guidelines includes thresholds for evaluating climate impacts, which include determining consistency with a local GHG reduction strategy that meets the criteria under State CEQA Guidelines Section 15183.5(b). The GHG plan most relevant to the VCMP is the 2024 Sunnyvale Climate Action Playbook.

A GHG report was completed for the project as part of preparation of the Air Quality, Greenhouse Gas Emissions, and Energy Analysis Report (AQ, GHG, and Energy Report) and subsequent memorandum detailing the findings of the analysis for the proposed project (FirstCarbon Solutions 2025a). The results of this analysis are summarized below. a) Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment?
The LUTE EIR determined significance by comparing the 2016 LUTE’s emissions to the City’s efficiency metric threshold of GHG emissions per service population based on the City’s GHG emissions inventory and emissions targets at that time.

Attachment 6

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4-32 De Guigne Drive Residential Project Environmental Review With respect to GHG emissions, State CEQA Guidelines Section 15064.4(a) states that lead agencies “shall make a good-faith effort, based to the extent possible on scientific and factual data, to describe, calculate or estimate” GHG emissions resulting from a project. The State CEQA Guidelines note that an agency has the discretion to either quantify a project’s GHG emissions or rely on a “qualitative analysis or performance-based standards” (Section 15064.4[a]). A lead agency may use a “model or methodology” to estimate GHG emissions and has the discretion to select the model or methodology it considers “most appropriate to enable decision makers to intelligently take into account the project’s incremental contribution to climate change” (Section 15064.4[c]). The State CEQA Guidelines provide that the lead agency should consider the following when determining the significance of impacts from GHG emissions on the environment (Section 15064.4[b]): (1) The extent a project may increase or reduce GHG emissions as compared to the existing environmental setting; (2) Whether the project emissions exceed a threshold of significance that the lead agency determines applies to the project; (3)The extent to which the project complies with regulations or requirements adopted to implement a statewide, regional, or local plan for the reduction or mitigation of GHG emissions. Thus, the project is analyzed for consistency with the City’s Playbook. The project’s GHG emissions, discussed below, were quantified for informational purposes only.

Generally, GHGs could be generated from a variety of activities and emission sources (e.g., exhaust emissions from off-road construction equipment, material delivery trips, and construction worker -commute trips). These emission types and associated levels fluctuate greatly depending on the type, number, and duration of usage for the varying equipment. The site preparation phase typically generates the most substantial emission levels because of the on-site equipment and ground-disturbing activities associated with grading, compacting, and excavation. Site preparation equipment and activities typically include backhoes, bulldozers, loaders, and excavation equipment (e.g., graders and scrapers). As shown in Table 12 of the AQ, GHG, and Energy Report, the project would generate a total of 1,294 MTCO
2e during the construction phase.

Operation activities related to the project would result in mobile-source GHG emissions associated with vehicle trips to and from the project site, area-source emissions from the operation of landscape maintenance equipment, energy-source emissions from the utilization of electricity, indirect water-related energy consumption associated with water use and the conveyance and treatment of wastewater, and waste-generated emissions from the transport and disposal of solid waste. As shown in Table 13 of the AQ, GHG, and Energy Report, operation of the project would generate a total of 2,019 MTCO2e per year (FirstCarbon Solutions 2025a).

The City’s Playbook identifies GHG reduction strategies that set the foundation for climate action and Plays (i.e., policies) that identify opportunities for action to achieve the City’s overall GHG reduction targets. The Playbook lays out six strategies that outline the overarching approach to achieve 80 percent GHG emissions reductions below 1990 levels by 2050. In each strategy, there are several Plays that identify areas for action and measurable targets to define progress. Consistency with the Playbook and the City’s long-term goal of carbon neutrality are being demonstrated through multiple project features. Table 4.6-1 in Section 4.6 “Energy,” above, summarizes in detail the project’s consistency with the Playbook (strategies and Plays that are not applicable to the project are not included in the consistency analysis) (FirstCarbon Solutions 2025a). As identified below, the project would attain the objectives of the Playbook. As identified in Table 4.6-1, the project would be consistent with the City’s Playbook due to the inclusion of project design features such as installation of solar PV panels, use of 100 percent carbon free electricity sourced from SVCE, all-electric project design, nearby proximity to existing transit services, and inclusion of electric vehicle ( EV) charging stations consistent with the City’s Reach Code.

The project’s land use and development intensities are consistent with the LUTE and what was assumed in the GHG analysis in the LUTE EIR. No changes in the GHG conditions for the project site have occurred since approval of the LUTE and the LUTE EIR. The project would not include any development beyond that assumed and analyzed in the LUTE EIR. Therefore, with the application of uniformly applied development standards and policies, t here are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding GHG emissions remain valid and no further analysis is required.

Attachment 6

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City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-33 Mitigation Measures
No mitigation measures are required.

Conclusion
The project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the conclusions of the LUTE EIR regarding climate change impacts remain valid and no additional analysis is required. b) Conflict with an applicable plan, policy, or regulation adopted for the purpose of reducing the emissions of greenhouse gases?
The project would be consistent with the City’s Playbook as identified in Table 4.6-1 in Section 4.6 “Energy,” above and discussed in item a) above (FirstCarbon Solutions 2025a). The project also is generally consistent with Plan Bay Area as an infill residential project near transit and would not impede any state- level Scoping Plan programs.

Mitigation Measures
No mitigation measures are required.

Conclusion
The project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the conclusions of the LUTE EIR regarding consistency with GHG reduction plans remain valid and no additional analysis is required.

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4-34 De Guigne Drive Residential Project Environmental Review

4.9 HAZARDS AND HAZARDOUS MATERIALS
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based
on Substantial
New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

9. Hazards and Hazardous Materials. Would the project:
a) Create a significant hazard to the
public or the environment through
the routine transport, use, or
disposal of hazardous materials?
Draft EIR Setting
pp. 3.3-1 to 3.3-9
Impacts 3.3.1 and

3.3.6 No No No No NA, impacts would
remain less than
significant
b) Create a significant hazard to the
public or the environment through
reasonably foreseeable upset and
accident conditions involving the
release of hazardous materials into
the environment?
Draft EIR Setting
pp. 3.3-1 to 3.3-9
Impacts 3.3.2 and

3.3.6 No No No No NA, impacts would
remain less than
significant
c) Emit hazardous emissions or handle
hazardous or acutely hazardous
materials, substances, or waste
within one-quarter mile of an
existing or proposed school?
Draft EIR Setting
pp. 3.3-1 to 3.3-9
Impacts 3.3.3 and

3.3.6 No No No No NA, impacts would
remain less than
significant
d) Be located on a site which is
included on a list of hazardous
materials sites compiled pursuant to
Government Code Section 65962.5
and, as a result, would it create a
significant hazard to the public or
the environment?
Draft EIR Setting
pp. 3.3-1 to 3.3-9
Impacts 3.3.2 and

3.3.6 No No No No NA, impacts would
remain less than
significant
e) For a project located within an airport
land use plan or, where such a plan
has not been adopted, within two
miles of a public airport or public use
airport, would the project result in a
safety hazard for people residing or
working in the project area?
Draft EIR Setting
pp. 3.3-1 to 3.3-9
Impacts 3.3.4 and

3.3.6 Final EIR pp 3.0-2
to 3.0-3
No No No No NA, impact would
remain less than
significant
f) For a project within the vicinity of a
private airstrip, would the project
result in a safety hazard for people
residing or working on the project
area?
Draft EIR Setting
pp. 3.3-1 to 3.3-9
and p. 3.6-28
Impacts 3.3.4 and

3.3.6 No No No No NA, no impact would
occur
g) Impair implementation of or
physically interfere with an adopted
emergency response plan or
emergency evacuation plan?
Draft EIR Setting
pp. 3.3-1 to 3.3-9
Impacts 3.3.5 and

3.3.6 No No No No NA, impacts would
remain less than
significant
h) Expose people or structures to a
significant risk of loss, injury, or
death involving wildland fires?
Draft EIR Setting
p. 3.3-15
No impact
No No No No NA, no impact would
occur
Attachment 6

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De Guigne Drive Residential Project Environmental Review 4-35

4.9.1 Discussion
No substantial change in the environmental and regulatory settings related to hazards and hazardous materials, described in LUTE Draft EIR Section 3.3, “Hazards and Human Health,” has occurred since certification of the LUTE Draft EIR.

A Phase I Environmental Site Assessment (ESA) was prepared for the southern portion of the project site (510 De Guigne Drive and 935, 945 Stewart Drive) in March 2024, while a separate Phase I ESA was prepared for the northern portion of the site (920, 930, 950 De Guigne Drive) in August 2024 (AEI 2024a, 2024b). A Limited Phase II Subsurface Investigation Report was prepared for the entire project site in November 2024 (AEI 2024c). In August 2025, an Additional Soil Vapor Investigation Report was prepared (AEI 2025a). Recognized Environmental Conditions (RECs) observed within portions of the project site include two known groundwater contamination plumes containing tetrachloroethylene, also known as perchloroethylene (PCE), cis-1, 2-dichloriethylene (2-DCE), trichloroethene (TCE), and total petroleum hydrocarbons. Both plumes are in the process of remedial activities and groundwater monitoring. Soil and soil gas samples were conducted as part of the Limited Phase II Subsurface Investigation Report.

Results of the sampling indicated that pesticide dieldrin, benzene, and ethylbenzene, PCE, and TCE were detected at levels above the residential ESLs, though benzene and ethylbenzene were determined not to pose an unacceptable risk to site users (AEI 2024c). An additional soil vapor investigation was performed at the site in 2025. Results of the 2025 investigation revealed that PCE, TCE, benzene, chloroform were detected at levels in exceedance of residential vapor ESLs during sampling, though it was determined that benzene levels would not pose an unacceptable risk to onsite users (AEI 2025a).

The project site is listed as an open site (as of May 2025) on the State Water Resources Control Board GeoTracker database (SWRCB 2025). As described in Chapter 2, “Project Description,” results of site investigations will continue to determine appropriate mitigation processes within the project site, including implementing the Site Management Plan (SMP), and installation of vapor intrusion mitigation systems (VIMS), where determined necessary. Implementation of the SMP would supplement and be consistent with federal, state, and local regulations regarding the handling of contaminated media and regulations addressing worker exposure including Federal and California Occupational Safety and Health Administration (OSHA) training and worker protection rules and regulations, Code of Federal Regulations Title 29, Part 1910.120 and California Code of Regulations Title 8, S ection 5192. The SMP includes protocols for appropriate soil management procedures, as they relate to the contaminants of potential concern, include measures to minimize potential exposure risks to workers and the community during excavation and grading, measures to reduce soil vapor intrusion, and provide for the proper management of hazardous materials that may be encountered during construction (AEI 2025b).
a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials?
Impact 3.3.1 in the LUTE Draft EIR evaluated whether implementation of the LUTE would increase the routine transport, use, or disposal of hazardous materials. The analysis concluded that although LUTE policies provide for additional nonresidential growth, hazardous materials use would not be expected to expand appreciably because the types of new businesses that would be expected would not involve extensive use of hazardous materials, as has occurred historically.

The analysis also stated that the transport, storage, use, and disposal of hazardous materials in land use activities associated with the LUTE would be required to comply with all applicable federal, state, and local regulations during construction and operation. Facilities that use hazardous materials are required to obtain permits and comply with appropriate regulatory agency standards designed to avoid hazardous materials releases. Compliance with federal, state, and local regulations and implementation of LUTE policies (Policy LT-1.11 and associated actions LT-1.11a though j) would ensure that the LUTE would have less-than-significant impacts related to creating a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials and that the LUTE would have a less than cumulatively considerable contribution to significant cumulative impacts (Impact 3.3.6).

Construction of the project would involve demolition of existing site structures and construction of residential uses.

As described above, RECs are present within the site and remedial actions related to contaminants (described above) Attachment 6

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4-36 De Guigne Drive Residential Project Environmental Review from the two groundwater plumes are ongoing. Operation of the project would result in residential uses on the project site that use common hazardous materials, such as cleaners, solvent, fuels, oils, or lubricants, typically used for routine cleaning and maintenance activities. The project would be subject to the federal, state, and local regulations that regulate hazardous material transport, use, and safety measures during construction and operation as discussed in the LUTE EIR. With the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding impacts from the routine transport, use, or disposal of hazardous materials remain valid and no further analysis is required.
b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and/or accident conditions involving the release of hazardous materials into the environment?
In the LUTE Draft EIR, Impact 3.3.2 evaluated whether implementation of LUTE policies and actions would provide for land uses that would involve the transportation, storage, use, and disposal of hazardous materials. These activities could result in the release of hazardous materials into the environment and exposure of the public to hazardous materials as a result of inadvertent releases or accidents. The analysis states that the transport, storage, and use of hazardous materials by developers, contractors, business owners, and others must occur in compliance with local, state, and federal regulations. Facilities that store or use hazardous materials are required to obtain permits and comply with appropriate regulatory agency standards designed to avoid hazardous material releases. Special regulations apply to operations that may result in hazardous emissions or use large quantities of regulated materials to ensure accidental release scenarios are considered and measures included in project design and operation to reduce the risk of accidents. In addition, transportation of hazardous materials into and within Sunnyvale is regulated to reduce the potential for transportation accidents involving hazardous materials. The LUTE EIR concludes that such impacts would be less than significant under project conditions and less than cumulatively considerable under cumulative conditions (Impact 3.3.6).

The project would have minimal hazards on the site from routine use of residential products. The project would be subject to the federal, state, and local regulations that regulate hazardous material use and safety measures associated with construction as discussed in the LUTE EIR. Therefore, with the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR related to hazardous materials handling remain valid and no further analysis is required.

Impact 3.3.2 also identified that implementation of the LUTE could expose the public to hazardous materials if new development or redevelopment were to be located on a site where historical uses have resulted in hazardous materials contamination of soil or groundwater due to discharges that may not have been regulated prior to the enactment of stringent regulations in place today, or through illegal waste disposal activities. In addition, buildings and/or sites could contain electrical transformers containing polychlorinated biphenyls and persistent residual chemicals, including pesticides, herbicides, and fertilizers. In addition, redevelopment activities associated with the LUTE could result in exposure to hazardous materials by disturbing and thus releasing asbestos and/or lead during demolition and remodeling activities. Prior to approving any project at a site that is known to have contamination from historical uses or at a site where the potential exists based on historical or current uses but has not yet been evaluated, the City must ensure the project is consistent with Policy SN-1.1 in the General Plan Safety and Noise Chapter. This policy directs that land use decisions be based on an awareness of the hazards and potential hazards for the specific parcel of land. In addition, under Policy SN-1.5, the City intends to promote a living and working environment safe from exposure to hazardous materials. Additionally, development would be subject to State regulations related to the disposal and handling of hazardous materials. The Resource Conservation Recovery Act includes requirements for the transportation, treatment, storage, and disposal of hazardous materials. The City’s Department of Public Services is the Certified Unified Program Agency for Sunnyvale and is responsible for managing enforcement activities for the storage, use, and disposal Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-37 of hazardous materials in the City. The LUTE EIR concludes that the potential for impacts from hazards released through redevelopment of contaminated sites would be less than significant under project conditions and less than cumulatively considerable under cumulative conditions (Impact 3.3.6).

As described above, the project site is listed as an open site (as of May 2025) on the State Water Resources Control Board GeoTracker database (SWRCB 2025). The Phase I ESAs conducted for the project site identified PCE, cis-1, 2- DCE, TCE, and total petroleum hydrocarbons. The Limited Phase II Subsurface Investigation Report included current and historical soil and soil gas samples. Samples of DDD, DDE, DDT, endrin, and lead were detected and did not exceed the levels above the residential screening levels. The pesticide dieldrin was observed above the ESLs . In addition, soil gas samples of benzene, ethylbenzene, PCE, and TCE were detected at levels above the residential ESLs.

However, the presence of benzene and ethylbenzene were determined to be consistent with minor spills from the presence of automobiles in the parking lots on the site, and therefore determined not to pose an unacceptable risk to site users (AEI 2024c). As discussed above, the project site continues to undergo additional investigation and sampling to determine the appropriate remediation process for presence of onsite RECs. Remedial actions would likely include implementation of a SMP and installation of VIMS. Through application of uniformly applied requirements for the handling of hazardous materials, the disturbance and disposal of contaminated soil would not exacerbate the existing hazard or result in a foreseeable accidental release that could result in a public health impact consistent with LUTE policies identified above.

The proposed project is required to comply with Sunnyvale Municipal Code requirements for the management of hazardous materials. Therefore, with the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR related to hazardous material handling remain valid and no further analysis is required. c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? Impact 3.3.3 in the LUTE Draft EIR analyzed the potential for implementation of the LUTE to locate schools in the vicinity of land uses involving the use, transport, disposal, or release of hazardous materials. The LUTE EIR concluded that such impacts would be less than significant under project conditions and less than cumulatively considerable under cumulative conditions (Impact 3.3.6).

Portnov Computer School, Sunnyvale KinderCare, and San Miguel Elementary School are located within one-quarter mile of the project site. Additionally, former Rainbow Montessori School classrooms located within one-quarter mile of the project site may potentially be used for King’s Academy elementary and middle school classrooms in the future. Construction activities would involve onsite demolition, ground disturbance and construction of new residential structures. As discussed above, RECs are present at the site, and a SMP would be implemented as part of the construction process, prior to construction of new structures. VIMS would be incorporated within select residential buildings of the site as well. Onsite conditions are limited to the project site and project construction would not result in the expansion (or emission) of RECs such that surrounding uses would be adversely affected.

Once operational, the project would include residential uses and would not result in any use or handling of substantial hazardous materials.

As discussed in impact a) and b), the project would be subject to the federal, state, and local regulations, including compliance with Sunnyvale Municipal Code requirements for the management of hazardous materials, that regulate hazardous material transport, use, and safety measures during project construction and operation. Therefore, with the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding impacts from hazardous materials near schools remain valid and no further analysis is required.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-38 De Guigne Drive Residential Project Environmental Review d) Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, would it create a significant hazard to the public or the environment?
See discussion under item b) above.
e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard for people residing or working in the project area? LUTE Draft EIR Impact 3.3.4 evaluated the potential for hazards associated with exposing additional workers and visitors to aircraft-related safety hazards by locating additional development within the approach path of Moffett Federal Airfield. The analysis noted that the Moffett Federal Airfield Comprehensive Land Use Plan (CLUP) includes land use policies and height restrictions for construction and new structures near the airfield. The LUTE also contains several policies and actions that would assist in reducing airport hazards (Policy 8 and associated Actions 1, 4, and 5).

In the LUTE Draft EIR, this impact was determined to be less than significant because compliance with Federal Aviation Administration regulations and airport land use commission requirements, including CLUP restrictions, as well as implementation of LUTE policies and actions, would reduce airport safety hazards. The LUTE EIR concludes that the LUTE’s contribution to aircraft-related safety hazards would be less than cumulatively considerable under cumulative conditions (Impact 3.3.6).

The project site is located approximately 2.8 miles southeast of Moffett Federal Airfield and is outside the CLUP boundaries. Therefore, with the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR related to airport safety hazards remain valid and no further analysis is required. f) For a project within the vicinity of a private airstrip, would the project result in a safety hazard for people residing or working in the project area? As identified on page 3.6-28 of the LUTE Draft EIR, Sunnyvale does not include and is not proximate to any private airfields. Therefore, no impacts related to private airfield safety under project or cumulative conditions were identified in the LUTE EIR.

No new private airports have been developed near the project site. The proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding hazards from proximity to private airstrips remain valid and no further analysis is required. g) Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan?
The potential for implementation of the LUTE to interfere with the City of Sunnyvale Emergency Plan was evaluated in Impact 3.3.5 of the LUTE Draft EIR. The analysis specified that the proposed roadway system in the LUTE would improve city roadway conditions from existing conditions, allowing better emergency vehicle access to residences as well as evacuation routes for area residents. Thus, impacts from implementation of the LUTE would result in a less - than-significant impact under project conditions and would have a less than cumulatively considerable contribution under cumulative conditions related to interference with an adopted emergency response plan or emergency evacuation plan.

The project is infill development to construct residential uses and would not modify the roadway network in the City in a manner that would obstruct emergency access. Street improvements resulting from the project would be limited to the project site and would promote traffic flow and emergency access on site. With the application of uniformly Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-39 applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR related to impacts from interference with emergency plans remain valid and no further analysis is required.
h) Expose people or structures to a significant risk of loss, injury, or death involving wildland fires?
As discussed on page 3.3-15 of the LUTE Draft EIR, the LUTE was determined to have no impact under project or cumulative conditions related to this threshold.

No changes to the location of the project have occurred and no changes to the risks from wildfires have occurred since approval of the LUTE. The project site is not in a high wildfire severity zone or near a wildland-urban interface. The proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off - site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR related to impacts from wildland fires remain valid and no further analysis is required.

Mitigation Measures
No significant hazard impacts were identified in the LUTE EIR, and no mitigation measures were required.

Conclusion
With the application of uniformly applied development standards and policies, t he proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the conclusions of the LUTE EIR related to impacts from hazards and hazardous materials remain valid and no additional analysis is required.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-40 De Guigne Drive Residential Project Environmental Review

4.10 HYDROLOGY AND WATER QUALITY
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not
Analyzed as
Significant
Effect in
LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based
on Substantial
New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

10. Hydrology and Water Quality. Would the project:
a) Violate any water quality standards
or waste discharge requirements or
otherwise substantially degrade
surface or groundwater quality?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impacts 3.8.1 and

3.8.4 No No No No NA, impacts would
remain less than
significant
b) Substantially deplete groundwater
supplies or interfere substantially with
groundwater recharge such that the
project may impede sustainable
groundwater management of the
basin?
Draft EIR Setting
pp. 3.11-1 to 3.11-11
Impacts 3.11.1.1 and

3.11.1.3 No No No No NA, impacts would
remain less than
significant
c) Substantially alter the existing drainage
pattern of the site or area, including
through the alteration of the course of
a stream or river, in a manner which
would result in substantial erosion or
siltation on- or off-site?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impacts 3.8.1 and

3.8.4 No No No No NA, impacts would
remain less than
significant
d) Substantially alter the existing
drainage pattern of the site or area,
including through the alteration of the
course of a stream or river, or
substantially increase the rate or
amount of surface runoff in a manner
which would result in flooding on- or
off-site?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impacts 3.8.2 and

3.8.5 No No No No NA, impacts would
remain less than
significant
e) Create or contribute runoff water
which would exceed the capacity of
existing or planned storm water
drainage systems or provide
substantial additional sources of
polluted runoff?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impacts 3.8.1 and

3.8.4 No No No No NA, impacts would
remain less than
significant
f) Otherwise substantially degrade
water quality?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impacts 3.8.1 and

3.8.4 No No No No NA, impacts would
remain less than
significant
g) Place housing within a 100-year flood
hazard area as mapped on a federal
Flood Hazard Boundary or Flood
Insurance Rate Map or other flood
hazard delineation map?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impacts 3.8.2 and

3.8.5 No No No No NA, impacts would
remain less than
significant
h) Place within a 100-year flood hazard
area structures which would impede
or redirect flood flows?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impacts 3.8.2 and

3.8.5 No No No No NA, impacts would
remain less than
significant
Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-41 Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not
Analyzed as
Significant
Effect in
LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based
on Substantial
New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

10. Hydrology and Water Quality. Would the project:
i) Expose people or structures to a
significant risk of loss, injury, or death
involving flooding, including flooding
as a result of the failure of a levee or
dam?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impacts 3.8.2 and

3.8.5 No No No No NA, impacts would
remain less than
significant
j) In flood hazard, tsunami, or seiche
zones, risk release of pollutants due
to project inundation?
Draft EIR Setting
pp. 3.8-1 to 3.8-15
Impact 3.8.3
No No No No NA, impacts would
remain less than
significant

4.10.1 Discussion
No substantial change in the environmental and regulatory settings related to hydrology and water quality, described in LUTE Draft EIR Section 3.8, “Hydrology and Water Quality,” have occurred since certification of the LUTE EIR. a) Violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or groundwater quality?
As analyzed in Impact 3.8.1 of the LUTE Draft EIR, construction activities associated with development of projects allowed under the LUTE would include grading, demolition, and vegetation removal, which would disturb and expose soils to water erosion, potentially increasing the amount of silt and debris entering downstream waterways. In addition, refueling and parking of construction equipment and other vehicles on site during construction could result in oil, grease, or related pollutant leaks and spills that may discharge into storm drains. Individual development projects would be required to comply with Chapter 12.60, Stormwater Management, of the Sunnyvale Municipal Code, as well as to implement BMPs for the prevention of erosion and the control of loose soil and sediment, to ensure that construction does not result in the movement of unwanted material into waters within or outside the plan area. The Municipal Code’s Stormwater Management chapter provides regulations and gives legal effect to certain requirements of the National Pollutant Discharge Elimination System (NPDES) permit issued to Sunnyvale regarding municipal stormwater and urban runoff requirements. During construction of projects in the City, the dischargers, through individual coverage under the State’s General Construction NPDES permit, must develop and implement a SWPPP and perform monitoring of discharges to stormwater systems to ensure compliance with state regulations and General Plan Policy EM-8.5.

Construction impacts would be less than significant under project and cumulative (Impact 3.8.4) conditions.

As indicated in the LUTE EIR, urban runoff pollutants such as heavy metals, oil and grease, sediment, and other chemicals would continue to be generated, but because the changes in land use are primarily related to increased intensity of development and not new land uses, the types and amounts of pollutants in stormwater runoff would not vary considerably from existing conditions. All private development projects would be required to include appropriate features to meet applicable Municipal Regional Stormwater Permit (MRP) Provision C.3 requirements and implement LID. Common LID strategies that would be appropriate for the plan area would include treatment methods such as bio-retention basins and flow-through planters, green roofs, media filtration devices, and pervious surfaces. These features would be included on individual sites on a project-by-project basis. Compliance with existing requirements of the City’s Municipal Code Chapter 12.60, the City of Sunnyvale Urban Runoff Management Plan, and MRP Provision C.3 requirements, along with implementation of General Plan policies EM-8.6, EM-10.1, and EM-10.3, would reduce surface water quality impacts associated with occupancy of projects in the L UTE to a less-than-significant level under project and cumulative (Impact 3.8.4) conditions.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-42 De Guigne Drive Residential Project Environmental Review The project is subject to the water quality control requirements identified above. Project design plans include replacing existing outdated stormwater facilities with low-impact design (LID) features such as bioswales and bioretention which improve water quality compared to existing conditions for the site (Appendix A). With the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR related to impacts from conflicts with water quality standards and waste discharge requirements remain valid and no further analysis is required. b) Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that the project may impede sustainable groundwater management of the basin?
The LUTE EIR indicated that implementation of projects allowed by the LUTE would have little or no effect on groundwater recharge because the City is largely built out and the LUTE would not reduce the amount of permeable surfaces. The City has historically relied on groundwater to meet between 4 and 11 percent of its total demand (approximately 1,000–2,700 acre-feet per year [AFY]). The City projects producing approximately 1,000 AFY from the groundwater basin through 2035 (LUTE Draft EIR page 3.11-5). Groundwater production is not expected to increase beyond 1,000 AFY except in multiple dry year conditions and is actively managed by the Santa Clara Valley Water District to avoid groundwater overdraft through its conjunctive use efforts. The LUTE EIR conclude d that impacts related to groundwater would be less than significant under project conditions and less than cumulatively considerable under cumulative conditions (Impact 3.11.1.3). No mitigation was required.

The project is not located within a groundwater basin subject to a sustainable groundwater management plan. The project would include connections to existing potable water mains within De Guigne and Stewart Drive; no groundwater use is proposed. The project would not substantially change development patterns and the areas of impermeable surfaces from that approved in the LUTE. The project decreases the project site’s impervious surface area from 737,649 sf (82 percent of the site) to 587,502 sf (66 percent of the site). Approximately 347,580 sf (39 percent) of the site would be covered by landscaped areas including lawns, shrubs, and trees as well as pervious pavers (Appendix A). Therefore, with the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off- site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR related to groundwater impacts remain valid and no further analysis is required. c) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, in a manner which would result in substantial on- or off-site erosion or siltation?
The project site lacks a stream or river. As discussed above, while the project may alter onsite drainage patterns, it would not result in substantial on- or off-site erosion or siltation due to the requirements to comply with the City’s Municipal Code Chapter 12.60, the City of Sunnyvale Urban Runoff Management Plan, MRP Provision C.3 requirements, and General Plan policies EM-8.6, EM-10.1, and EM-10.3. See discussion and impact conclusions under item a) above. d) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner which would result in on- or off-site flooding? Impact 3.8.2 in the LUTE Draft EIR identified locations in the City that are within 100-year flood hazard Zone AO, as designated by the Federal Emergency Management Agency, or could be inundated from levee failure. Chapter 16.62, Prevention of Flood Damage, of Sunnyvale’s Buildings and Construction Ordinance includes standards for construction in 100-year flood hazard areas. The standards for construction generally require the elevation of the lowest floor of any structure to or above the base flood elevation, anchoring, and the use of flood damage-resistant materials and methods. Individual development projects are required under Municipal Code Section 12.60.160 to demonstrate that Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-43 each individual development project would not increase runoff over pre-project rates and durations. In addition, General Plan Policy EM-9.1 requires that the City maintain and operate the storm drain system so that stormwater is drained from 95 percent of the streets within one hour after a storm stops. For flood-prone locations, Policy EM-10.2 requires incorporation of appropriate controls to detain excess stormwater. Compliance with the existing regulations in the City’s Municipal Code would reduce potential impacts associated with flooding and stormwater drainage to a level that is less- than-significant for the LUTE under project and cumulative (Impact 3.8.5) conditions.

The project site is not located within the 100-year flood hazard Zone AO. The project site is in Flood Zone X (an area with reduced flood risk due to a levee). The proposed project is required to comply with Section 12.60.160 of the City’s Municipal Code. Project design plans include water quality control and drainage features for the site (Appendix A), and the project would not increase stormwater runoff compared to existing conditions. With the application of uniformly applied development standards and policies, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR related to flooding impacts remain valid and no further analysis is required. e) Create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff?
See discussion under items a) and d) above.
f) Otherwise substantially degrade water quality?
See discussion under item a) above.
g) Place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? See discussion under item d) above.
h) Place within a 100-year flood hazard area structures that would impede or redirect flood flows?
See discussion under item d) above.
i) Expose people or structures to a significant risk of loss, injury, or death involving flooding, including flooding as a result of the failure of a levee or dam? See discussion under item d) above.

The project site is not located in an inundation area. Therefore, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding impacts from levee and dam failure remain valid and no further analysis is required.
j) In flood hazard, tsunami, or seiche zones, risk release of pollutants due to project inundation?
As described in LUTE Draft EIR Impact 3.8.3, seiches and tsunamis would not be expected to affect areas developed as part of the LUTE. It is probable that an earthquake similar to the 1906 earthquake would be the largest to occur in the Bay Area; consequently, seiches with an increase in water elevation of more than 4 inches would be considered unlikely. Tsunamis would only be expected to affect low-lying marsh areas and bayward portions of sloughs. Mudflow (a type of landslide) would not be a hazard in Sunnyvale because of the city’s generally flat terrain and distance from hilly or mountainous areas. The LUTE EIR concludes that impacts related to inundation by seiche, tsunami, or Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-44 De Guigne Drive Residential Project Environmental Review mudflow would be less than significant under project conditions. The LUTE would not exacerbate the likelihood for inundation by seiche, tsunami, or mudflow.

The project site is located on flat terrain in the inland portion of the City and outside of the marsh areas of the Bay.

The project site is not in a flood hazard, tsunami, or seiche zones. The project is required to comply with Section

12.60.160 of the City’s Municipal Code, and project design plans include water quality control and drainage features for the site. The project would not exacerbate the likelihood for inundation by seiche, tsunami, flood hazard, or mudflow. Therefore, there are no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off - site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR related to impacts from inundation by seiche, tsunami, flood hazard, and mudflow remain valid and no further analysis is required.

Mitigation Measures
No significant hydrology impacts were identified in the LUTE EIR, and no mitigation measures were required.

Conclusion
No new circumstances or project changes have occurred, nor has any new information been found requiring new analysis or verification. Therefore, with the application of uniformly applied development standards and policies, t he proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off - site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there are no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The conclusions of the LUTE EIR regarding impacts to hydrology and water quality remain valid and no additional analysis is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-45

4.11 LAND USE AND PLANNING
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

11. Land Use and Planning. Would the project:
a) Physically divide an established
community?
DEIR EIR Setting pp.

3.1-1 to 3.1-10
Impacts 3.1.1 and 3.1.5
No No No No NA, this impact would
remain less than
significant
b) Conflict with any applicable land
use plan, policy, or regulation of
an agency with jurisdiction over
the project (including, but not
limited to the general plan,
specific plan, local coastal
program, or zoning ordinance)
adopted for the purpose of
avoiding or mitigating an
environmental effect?
DEIR EIR Setting pp.

3.1-1 to 3.1-10
Impacts 3.1.2, 3.1.3,
and 3.1.5
No No No No NA, this impact would
remain less than
significant

4.11.1 Discussion
No substantial change in the environmental and regulatory settings related to land use and planning, described in LUTE Draft EIR Section 3.1, “Land Use,” has occurred since certification of the LUTE EIR. a) Physically divide an established community?
Impact 3.1.1 of the LUTE Draft EIR identified that the LUTE does not include large-scale infrastructure projects such as new freeways or high-volume roadways that would divide an established community. Likewise, critical transportation infrastructure linking one neighborhood to another would not be removed as part of the LUTE. Implementation of the policy provisions of the LUTE would ensure integration and compatibility of new development with existing land use conditions. This impact was determined to be less than significant under project and cumulative (Impact 3.1.5 ) conditions.

The project proposes residential development on an existing office park in an area surrounded by additional residential, office, and commercial uses, and is considered infill development. The proposed project would not alter local land use patterns or obstruct movement through the area. The project provides a new trail that would better link together the community. Therefore, with the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off- site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR pertaining to physical divisions of established communities remain valid and no further analysis is required.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-46 De Guigne Drive Residential Project Environmental Review b) Conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to, a general plan, specific plan, local coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect?
Impacts 3.1.2 and 3.1.3 of the LUTE EIR evaluated whether the LUTE would be consistent with adopted City and regional land use plans and policies and concluded that the LUTE’s impact would be less than significant under project and cumulative (Impact 3.1.5) conditions.

The project is consistent with the LUTE and City land use regulations. It is consistent with the LUTE’s land use designation and policy provisions for RMED (i.e., residential). Therefore, with the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regarding consistency with applicable land use plans, policies, and regulations adopted for the purpose of avoiding or mitigating environmental effects remain valid and no further analysis is required.

Mitigation Measures
No significant land use impacts were identified in the LUTE EIR, and no mitigation measures were required.

Conclusion
No new circumstances or project changes have occurred, nor has any new information been identified requiring new analysis or verification. Therefore, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. T he conclusions of the LUTE EIR regarding land use and planning remain valid and no additional analysis is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-47

4.12 MINERAL RESOURCES
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not
Analyzed as
Significant
Effect in
LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

12. Mineral Resources. Would the project:
a) Result in the loss of availability
of a known mineral resource
that would be of value to the
region and the residents of the
state?
Draft EIR p. 3.7-14.

Scoped out of
impact analysis.

No No No No NA, no impact would
occur
b) Result in the loss of availability
of a locally important mineral
resource recovery site
delineated on a local general
plan, specific plan, or other land
use plan?
Draft EIR p. 3.7-14.

Scoped out of
impact analysis.

No No No No NA, no impact would
occur

4.12.1 Discussion
a) Result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the state?
b) Result in the loss of availability of a locally important mineral resource recovery site delineated on a local general plan, specific plan, or other land use plan? Sunnyvale does not contain any active mines or known areas with mineral resource deposits or resources of statewide importance. The project site does not contain any of these resources and would also have no impact .

Conclusion
As discussed on page 3.7-14 of the LUTE Draft EIR, no active mines and no known areas with mineral resource deposits or resources of statewide importance are located in Sunnyvale. Therefore, no impact to availability of a known mineral resource would result. The proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR pertaining to mineral resources remain valid and no further analysis is required.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-48 De Guigne Drive Residential Project Environmental Review

4.13 NOISE
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based
on Substantial
New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

13. Noise. Would the project result in:
a) Generation of a substantial
temporary or permanent increase
in ambient noise levels in the
vicinity of the project in excess of
standards established in the local
general plan or noise ordinance,
or in other applicable local, state,
or federal standards
Draft EIR Setting
pp. 3.6-1 to 3.6-27
Impact 3.6.1
No No No No NA, impact remains
less than significant
b) Generation of excessive
groundborne vibration or
groundborne noise levels?
Draft EIR Setting
pp. 3.6-1 to 3.6-27
Impact 3.6.3
No No No No NA, impact remains
less than significant
with mitigation
c) For a project located within the
vicinity of a private airstrip or an
airport land use plan or, where
such a plan has not been adopted,
within two miles of a public airport
or public use airport, would the
project expose people residing or
working in the project area to
excessive noise levels?
Draft EIR p. 3.6-28
Scoped out of
impact analysis.

No No No No NA, no impact would
occur

4.13.1 Discussion
No substantial change in the environmental and regulatory settings related to noise and vibration, described in LUTE Draft EIR Section 3.6, “Noise,” has occurred since certification of the LUTE EIR. No new substantial noise sources have been introduced near the project site since the LUTE EIR was prepared.

A Noise Impact Analysis Report was prepared for the project in April 2025 (FirstCarbon Solutions 2025b). Results of the analysis are summarized below.
a) Generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or in other applicable local, state, or federal standards? Impact 3.6.1 of the LUTE EIR identified less-than-significant impacts related to subsequent development generating noise levels that exceed City noise standards. However, the City does not establish noise level thresholds for construction activities, this analysis uses the noise limits established by the FTA of 80 dBA Leq,8hr to identify the potential for impacts due to substantial temporary construction noise Implementation of the proposed project would include construction noise from equipment ranging up to approximately 85 A-weighted decibels (dBA) equivalent noise level (Lmax) at a distance of 50 feet. The site preparation phase, which includes excavation and grading of the site, tends to generate the highest noise levels because the noisiest construction equipment is earthmoving equipment. Earthmoving equipment includes excavating machinery and compacting equipment, such as bulldozers, draglines, backhoes, front loaders, roller compactors, scrapers, and Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-49 graders. The nearest residential receptor includes multi-family homes located west and east of the project site, approximately 90 feet and 50 feet from the nearest acoustical center of construction where the heaviest pieces of equipment would operate. At this distance, reasonable worst-case hourly average construction noise levels would attenuate up to 76 dBA Leq. When averaged over an 8-hour workday, construction noise levels during the loudest phase of construction as equipment operates across the project site could range up to 70 dBA L eq,8hr as measured at the nearest sensitive receptors. These reasonable worst-case construction noise levels would not exceed the FTA’s daytime exterior threshold of 80 dBA Leq,8hr as measured at the nearest residential land use (FTA 2018:179).

In addition, existing trips along Stewart Drive, adjacent to the project site, average 5,920 daily trips. Based on the air quality analysis prepared for the project, the building construction phase would generate the highest daily trips, with an approximate total of 249 average daily trips (FirstCarbon Solutions 2025a). These average daily trips would not double traffic volumes along roadway segments accessing the project site (FTA 2018:201).

Implementation of the project would include operation of new mechanical ventilation equipment. Noise levels for residential-grade mechanical ventilation equipment systems range up to approximately 70 dBA Leq at a distance of 3 feet. The project would include residential-grade mechanical ventilation equipment for each unit. The nearest residential receptor includes multi-family homes located east of the project site, approximately 60 feet from the nearest location where new mechanical ventilation equipment could be located. The combined reasonable worst-case operational noise level of multiple mechanical ventilation systems operating simultaneously would be 30 dBA Leq as measured at the property line of the nearest off-site residential receptor (assuming minimal shield reduction for the existing 6-foot cement brick wall), based on the noise technical study prepared for this project (FirstCarbon Solutions 2025b). These reasonable worst-case mechanical ventilation equipment operational noise levels would not exceed the City’s most restrictive daytime or nighttime noise performance thresholds as measured at the nearest receiving residential land uses.

In addition, these noise levels would not exceed documented existing ambient noise levels in the project vicinity.

Therefore, the mechanical ventilation equipment operation noise levels would not result in a substantial permanent increase in ambient noise levels in excess of any of the City’s noise performance thresholds.

The project would be designed to comply with the City’s Noise Ordinance and not result in an increase in noise levels at existing adjacent properties. In addition, the project would result in a net increase of 2,896 daily trips from existing 5,920 daily trips. Therefore, project trips would not result in a doubling of trips on access roadway segments in the project vicinity and would not result in increase in traffic-related noise at existing adjacent properties. Therefore, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR pertaining to exposure of persons to noise in excess of applicable standards remain valid and no further analysis is required. b) Generation of excessive groundborne vibration or groundborne noise levels? Impact 3.6.3 of the LUTE Draft EIR evaluated the potential for construction activities to generate excess groundborne vibration and identified that damage to older buildings can occur at 0.25 inches per second of peak particle velocity (PPV) and at 0.5 inches per second PPV for conventional buildings. This impact was identified as potentially significant. Mitigation Measure 3.6.3 requires noise- and vibration-reducing pile-driving techniques to be employed during construction and monitoring to ensure no damage to nearby structures occurs (i.e., vibrations above PPVs of

0.25 inches per second at nearby structures). The LUTE Draft EIR identified that implementation of M itigation Measure 3.6.3 (restated below) would reduce the construction vibration impact to a less-than-significant level.

The project would not entail the use of pile drivers or unusual construction equipment beyond what was evaluated in the LUTE EIR and would be required to comply with the same mitigation measures in the LUTE EIR. The Noise Impact Analysis Report prepared for the project concluded that vibration levels during construction are not expected to generate excess groundborne vibration (FirstCarbon Solutions 2025b). Any project stationary noise levels (i.e., those that may be associated with transformers, HVAC systems, etc.) would be required to comply with the City’s noise level standards. Therefore, the project would (1) have no peculiar impacts, (2) not result in impacts that were not analyzed in the LUTE EIR, (3) not result in any significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-50 De Guigne Drive Residential Project Environmental Review LUTE EIR. The findings of the certified LUTE EIR pertaining to groundborne vibration and noise remain valid and no further analysis is required.
c) For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels?
Impact 3.6.5 of the LUTE Draft EIR identified that compliance with the CLUP for Moffett Field Airfield and with the City’s normally acceptable noise level standards effectively reduces potential aircraft noise impacts. LUTE Draft EIR page 3.6-28 identified that no private airfields are located near the City and thus there would be no impact.

No private airstrips have been developed in the project area since certification of the LUTE EIR. Therefore, there are no new circumstances or new information requiring new analysis or verification. The project site is located outside of the CLUP noise contours of Moffett Field Airfield. Therefore, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR regardi ng exposure of people to excessive noise from airports remain valid and no further analysis is required.

Mitigation Measures
The following mitigation measure was identified in the LUTE EIR and would continue to remain applicable if the proposed project were approved. Adopted LUTE EIR Mitigation Measures MM 3.6.3 includes requirements for pile driving. The project would not require pile driving and the vibration portion of the measure is not applicable to the project.

LUTE EIR Adopted Mitigation Measure MM 3.6.3
New development and public projects shall employ site-specific noise attenuation measures during construction to reduce the generation of construction noise and vibration. These measures shall be included in a Noise Control Plan that shall be submitted for review and approval by the City. Measures specified in the Noise Control Plan and implemented during construction shall include, at a minimum, the following noise control strategies:
 Equipment and trucks used for construction shall use the best available noise control techniques (e.g., improved mufflers, equipment redesign, use of intake silencers, ducts, engine enclosures, and acoustically attenuating shields or shrouds);
 Impact tools (e.g., jackhammers, pavement breakers, and rock drills) used for construction shall be hydraulically or electrically powered wherever possible to avoid noise associated with compressed air exhaust from pneumatically powered tools; and
 Stationary noise sources shall be located as far from adjacent receptors as possible, and they shall be muffled and enclosed within temporary sheds, incorporate insulation barriers, or include other measures.  Noise and vibration reducing pile-driving techniques shall be employed during construction and will be monitored to ensure no damage to nearby structures occurs (i.e., vibrations above peak particle velocity [PPVs ] of

0.25 inches per second at nearby structures). These techniques shall include:
 Installing intake and exhaust mufflers on pile-driving equipment;  Vibrating piles into place when feasible, and installing shrouds around the pile- driving hammer where feasible;
 Implementing “quiet” pile-driving technology (such as pre-drilling of piles and the use of more than one pile driver to shorten the total pile driving duration), where feasible, in consideration of geotechnical and structural requirements and conditions;
Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-51  Use cushion blocks to dampen impact noise, if feasible based on soil conditions. Cushion blocks are blocks of material that are used with impact hammer pile drivers. They consist of blocks of material placed atop a piling during installation to minimize noise generated when driving the pile. Materials typically used for cushion blocks include wood, nylon and micarta (a composite material); and  At least 48 hours prior to pile-driving activities, notifying building owners and occupants within 600 feet of the project area of the dates, hours, and expected duration of such activities.

Conclusion
No new circumstances or project changes have occurred, nor has any substantially important new information been found requiring new analysis or verification. Therefore, with the application of uniformly applied development standards and policies, the proposed project would (1) have no peculiar impacts, (2) not result in impacts that were not analyzed in the LUTE EIR, (3) not result in any significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. In addition, as required by the LUTE EIR, the applicant must comply with LUTE Mitigation Measures 3.6.3, which ensures the project’s compliance with the requirements of the LUTE that address construction noise. The conclusions of the LUTE EIR regarding noise and vibration remain valid and no further analysis is required.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-52 De Guigne Drive Residential Project Environmental Review

4.14 POPULATION AND HOUSING
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

14. Population and Housing. Would the project:
a) Induce substantial unplanned
population growth in an area, either
directly (for example, by proposing
new homes and businesses) or
indirectly (for example, through
extension of roads or other
infrastructure)?
Draft EIR Setting
pp. 3.2-1 to 3.2-3
Impacts 3.2.1 and

3.2.3 No No No No NA, impacts would
remain less than
significant
b) Displace substantial numbers of
existing housing, necessitating the
construction of replacement
housing elsewhere?
Draft EIR Setting
pp. 3.2-1 to 3.2-3
Impacts 3.2.2 and

3.2.4 No No No No NA, impacts would
remain less than
significant.

4.14.1 Discussion
No substantial change in the regulatory setting related to population and housing, described in LUTE Draft EIR Section 3.2, “Population, Housing, and Employment,” has occurred since certification of the LUTE EIR. As described in the project description, the proposed project is consistent with the LUTE. a) Induce substantial unplanned population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)?
LUTE Draft EIR Impact 3.2.1 evaluated whether new development in Sunnyvale would induce new growth under the LUTE. The analysis noted that the number of additional jobs that would be generated by the LUTE would be within the overall employment growth projections identified by the Association of Bay Area Governments . The LUTE does not propose any new housing and would not directly induce population growth in the area under project or cumulative (Impact 3.2.3) conditions.

The applicant proposes a new residential community with a total of 370 residential units and an overall density of 18 dwelling units per acre, consistent with the RMED designation for the project site in the LUTE and generally considered in the adopted Housing Element Update. The project would provide infill housing to accommodate existing growth in the City. Because the proposed project is consistent with the land use designation set forth in the LUTE, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR pertaining to population growth remain valid and no further analysis is required. b) Displace substantial numbers of people, necessitating the construction of replacement housing elsewhere?
As described in Impact 3.2.2 of the LUTE Draft EIR, the intent of the LUTE is to accommodate anticipated growth through a compact urban form that seeks to make efficient use of existing infrastructure and public services, thus minimizing the need for new or significantly expanded infrastructure that could be the impetus for the removal of housing units and/or businesses. Because most of Sunnyvale has been developed with urban uses, the LUTE focuses Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-53 on redeveloping existing properties. It is not expected that residential uses would convert to nonresidential uses. The LUTE EIR concludes that impacts related to displacement of people are less than significant under project conditions and less than cumulatively considerable under cumulative conditions (Impact 3.2.4).

The project site does not include any existing housing and the project would have no impact related to the displacement of housing or people. Rather, the proposed project would provide housing to accommodate growth in the City. Therefore, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR pertaining to displacement remain valid and no further analysis is required.

Mitigation Measures
No significant population and housing impacts were identified in the LUTE EIR, and no mitigation measures were required.

Conclusion
No new circumstances or project changes have occurred, nor has any new information been found requiring new analysis or verification. Therefore, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The conclusions of the LUTE EIR pertaining to population and housing remain valid and no further analysis is required .

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-54 De Guigne Drive Residential Project Environmental Review

4.15 PUBLIC SERVICES
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

15. Public Services.
a) Would the project result in
substantial adverse physical impacts
associated with the provision of new
or physically altered governmental
facilities, need for new or physically
altered governmental facilities, the
construction of which could cause
significant environmental impacts, to
maintain acceptable service ratios,
response times or other performance
objectives for any public services:

i) Fire protection? Draft EIR Setting
pp. 4.0-1 – 4.0-3
Impacts 4.1.1 and

4.1.2 No No No No NA, impact remains
less than significant
ii) Police protection? Draft EIR Setting
pp. 4.0-6
Impacts 4.2.1 and

4.2.2 No No No No NA, impact remains
less than significant
iii) Schools? Draft EIR Setting
pp. 4.0-9 – 4.0-10
Impacts 4.3.1 and

4.3.2 No No No No NA, impact remains
less than significant
iv) Parks? Draft EIR Setting
pp. 4.0-15
Impact 4.4.1 and

4.4.2 No No No No NA, impact remains
less than significant

4.15.1 Discussion
No substantial change in the regulatory setting related to public services, described in LUTE Draft EIR Chapter 4, “Public Services,” has occurred since certification of the LUTE EIR. a) Result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, or the need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times, or other performance objectives for any of the public services:

Fire protection?
Impact 4.1.1 in the LUTE Draft EIR evaluated whether implementation of the LUTE would increase the demand for fire protection and emergency medical services. The analysis noted that it is anticipated that population and employment Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-55 growth resulting from implementation of the LUTE would increase the demand for fire protection services. The LUTE includes Policy 104 that provides general direction regarding how public services should be provided . The Sunnyvale General Plan contains fire protection policies that address maintaining timely response to emergencies and ensuring adequate equipment and facilities are maintained (Policies SN-3.1 and SN-5.1). Additionally, Impact 4.1.2 notes that development under the LUTE would be subject to developer fees, which would provide sufficient resources to serve the projected needs of the Sunnyvale Department of Public Safety Bureau of Fire Services (Fire Bureau) under cumulative conditions. Implementation of the LUTE would result in a less- than-significant impact under project conditions and a less than cumulatively considerable impact under cumulative conditions (Impact 4.1.2).

The proposed project would be required to meet all City requirements regarding fire protection and public safety, including fire access. The project would redevelop an existing business park to a new residential community with a total of 370 residential units. The proposed project could result in a net increase in demand for fire protection and emergency medical services; however, this increase is within the increase contemplated by the LUTE and its EIR. In addition, consistent with the LUTE, the project applicant will be required to pay developer fees to provide sufficient resources to serve the City. The project would not trigger the need to construct new fire facilities that could result in physical environmental impacts. Thus, with the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR pertaining to fire protection services remain valid and no further analysis is required.

Police protection?
Impact 4.2.1 in the LUTE Draft EIR evaluated whether implementation of the LUTE would increase the demand for law enforcement services. The analysis noted that it is anticipated that population, the number of housing units, and the increase in employment resulting from implementation of the LUTE would increase the demand for law enforcement services. The LUTE includes Policy LT-14.9 that provides general direction regarding how public services should be provided. The Sunnyvale General Plan contains Policy SN-3.1 that addresses maintaining timely response to emergencies. Implementation of the LUTE would result in a less-than-significant impact under project conditions and a less than cumulatively considerable impact under cumulative conditions (Impact 4.2.2) The proposed project would redevelop an existing business park to a new residential community with a total of 370 residential units. It would result in a net increase in demand for law enforcement services; however, this increase is within the increase contemplated by the LUTE and its EIR. In addition, consistent with the LUTE, the project applicant would be required to pay developer fees to provide sufficient resources to serve the City. The proposed project would not trigger the need to construct new law enforcement facilities that could result in physical environmental impacts. With the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR pertaining to law enforcement services remain valid and no further analysis is required.

Schools?
Impact 4.3.1 in the LUTE Draft EIR evaluated whether implementation of the LUTE would increase population in the local school districts’ service areas, which would subsequently increase student enrollment in local schools.

Subsequent development under the Draft LUTE, including residential and commercial development, would be subject to school facility fees to pay for additional school facility needs. With payment of school facility fees, th e impact from buildout of the LUTE would be less than significant under project conditions and less then cumulatively considerable under cumulative conditions (Impact 4.3.2).

The proposed project would redevelop an existing business park to a new residential community with a total of 370 residential units. In accordance with the LUTE, the project applicant is required to pay school facility fees to ensure that impacts would be less than significant. The project would not trigger the need to construct school facilities that Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-56 De Guigne Drive Residential Project Environmental Review could result in physical environmental impacts. Thus, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR pertaining to schools remain valid and no further analysis is required.

Parks?
See discussion under item b) in Section 4.16, Recreation.

Mitigation Measures
No mitigation measures were required for the certified LUTE EIR regarding public services. No additional mitigation measures are required for the project.

Conclusion
With the application of uniformly applied development standards and policies, t he proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The conclusions of the LUTE EIR pertaining to public services remain valid and no further analysis is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-57

4.16 RECREATION
Environmental Issue Area
Where Impact Was
Analyzed in LUTE
Draft and Final EIR
Any
Peculiar
Impact?
Any Impact
Not Analyzed
as Significant
Effect in LUTE
EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based
on Substantial
New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

16. Recreation.
a) Would the project increase the use
of existing neighborhood and
regional parks or other
recreational facilities such that
substantial physical deterioration
of the facility would occur or be
accelerated?
Draft EIR Setting
p. 4.0-15 and 4.0-16
Impacts 4.4.1 and

4.4.2 No No No No NA, impact remains
less than significant
b) Does the project include
recreational facilities or require the
construction or expansion of
recreational facilities which might
have an adverse physical effect on
the environment?
Draft EIR Setting
p. 4.0-15 and 4.0-16
Impacts 4.4.1 and

4.4.2 No No No No NA, impact remains
less than significant

4.16.1 Discussion
No substantial change in the regulatory setting related to recreation, described in LUTE Draft EIR Chapter 4, “Public Services,” has occurred since certification of the LUTE EIR. a) Increase the use of existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated?
See discussion under item b) below.
b) Include recreational facilities or require the construction or expansion of recreational facilities that might have an adverse physical effect on the environment? Impact 4.4.1 of the LUTE Draft EIR evaluated whether the increase in employees and residents from implementation of the LUTE would increase demand for public parks. Per the City’s Municipal Code, new residential development would be required to dedicate land, pay a fee in lieu thereof, or both, for park or recreational purposes at a ratio of 5 acres per 1,000 residents. These fees may be used to upgrade existing park facilities. The LUTE Draft EIR also programmatically evaluated the environmental impacts of upgrading existing parks and the development of new park facilities as part of the overall development analyzed in the EIR (LUTE Draft EIR page 4.0-17). Therefore, the impact conclusions in the LUTE EIR capture the impacts from construction of new parks and recreational facilities. The LUTE EIR concludes that the LUTE’s impact on recreational facilities and parks would be less than significant under project conditions and less than cumulatively considerable under cumulative conditions (Impact 4.4.2).

The proposed project would redevelop an existing business park to a new residential community with a total of 370 residential units, which would create additional park and recreation demands. The proposed project would include several on-site recreational amenities for project residents, including community gathering spaces, a pool, and a pedestrian/bicycle trail. In addition, the project applicant would be required to pay a fee for park or recreation purposes associated with the increase in population per the City’s Municipal Code. Therefore, with the payment of the necessary fees, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, Attachment 6

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4-58 De Guigne Drive Residential Project Environmental Review or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. T he findings of the certified LUTE EIR pertaining to recreation remain valid and no further analysis is required.

Mitigation Measures
No mitigation measures pertaining to parks and recreational facilities were identified in the certified LUTE EIR regarding recreation, and no additional mitigation measures are required for the project.

Conclusion
The proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the conclusions of the LUTE EIR pertaining to recreation remain valid and no further analysis is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-59

4.17 TRANSPORTATION/TRAFFIC
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any
Peculiar
Impact?
Any Impact Not
Analyzed as
Significant Effect
in LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based on
Substantial New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

17. Transportation/Traffic. Would the project:
a) Conflict with a program, plan,
ordinance, or policy addressing
the circulation system, including
transit, roadway, bicycle, and
pedestrian facilities?
Transit: Draft EIR
Setting pp. 3.4-34
to 3.4-40
Impacts 3.4.1 and

3.4.2 Bicycle: Draft EIR
Setting pp. 3.4-33
Impact 3.4.3
Pedestrian: Draft
EIR Setting pp.

3.4-33
Impact 3.4.4
No No No No NA, impact remains
less than significant
and significant and
unavoidable for
impacts to transit
travel times.
b) Conflict or be inconsistent with
CEQA Guidelines Section 15064.3,
subdivision (b)?
Draft EIR Setting
pp. 3.4-47 to

3.4-48
No impact
conclusion
No No No No NA
c) Substantially increase hazards
due to a geometric design
feature (e.g., sharp curves or
dangerous intersections) or
incompatible uses (e.g., farm
equipment)?
Draft EIR Setting
pp. 3.4-1 to

3.4-45
Impact 3.4.5
No No No No NA, impact remains
less than significant
d) Result in inadequate emergency
access?
Draft EIR Setting
pp. 3.4-1 to

3.4-45
Impact 3.4.6
No No No No NA, impact remains
less than significant

4.17.1 Discussion
Pursuant to SB 743, PRC Section 21099, and California Code of Regulations Section 15064.3(a), generally, VMT is the most appropriate measure of transportation impacts and a project’s effect on automobile delay no longer constitutes a significant impact under CEQA. Additionally, on June 30, 2020, the Sunnyvale City Council adopted a resolution and Council Policy (Policy 1.2.8, Transportation Analysis Policy) establishing VMT as the primary threshold of significance for analysis of transportation impacts under CEQA. Policy 1.2.8 notes that the City will retain LOS as an operational measurement of intersection efficiency but reiterates that a project’s effect on LOS (i.e., automobile delay) is no longer considered an environmental impact under CEQA. The LUTE EIR was completed prior to these changes to CEQA and City Council Policy 1.2.8.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-60 De Guigne Drive Residential Project Environmental Review a) Conflict with a program, plan, ordinance, or policy addressing the circulation system, including transit, roadway, bicycle, and pedestrian facilities? Potential conflicts with public transit, bicycle, and pedestrian facilities and uses are addressed in Impacts 3.4.1 and

3.4.2 (public transit), 3.4.3 (bicycle facilities), and 3.4.4 (pedestrian facilities) of the LUTE EIR.

Public Transit
As identified in Impacts 3.4.1 and 3.4.2 of the LUTE Draft EIR, the LUTE would increase the demand for transit and transit travel times would be adversely impacted due to the degradation of LOS associated with implementation of the LUTE. Impact 3.4.1 pertaining to the increased demand for transit was determined to be less than significant; however, Impact 3.4.2 concluded that impacts related to transit travel times would be significant and unavoidable with implementation of all feasible mitigation measures.

The proposed project would redevelop an existing business park to a new residential community with a total of 370 residential units. The project site is in proximity to multiple Valley Transportation Authority (VTA) transit stops. The nearest stops to the project site are an Altamont Corridor Express (ACE) Gray Shuttle within 400 feet (an approximately 2-minute walk), VTA Routes 55 and 255 within 0.2 mile (an approximately 5-minute walk), and VTA Route 20 and an ACE Grey Shuttle within 0.3 mile (an approximately 7-minute walk). The proposed project would encourage transit use, which is consistent with the goals of a transit priority area. Per the Technical Advisory on Evaluating Transportation Impacts in CEQA, the addition of new transit users is not considered an adverse impact to the transit network (Governor’s Office of Planning and Research 2018). Finally, the proposed project would not introduce any features that would block access to a transit stop or block a transit route. Therefore, the proposed project would not disrupt existing or planned transit services or facilities, nor would it create inconsistencies with any adopted programs, plans, ordinances, or policies related to transit. Thus, no new significant impacts or substantially more severe impacts would occur. The findings of the certified LUTE EIR remain valid and no further analysis is required.

Bicycle and Pedestrian Facilities
As identified in Impact 3.4.3 of the LUTE Draft EIR, the LUTE includes policies and actions including improving bicycle facilities as part of transportation improvement projects, providing linkages to all modes of travel, and implementing a citywide bike plan to improve bicycle access. Impact 3.4.3 related to bicycle facilities was determined to be less than significant. As identified in Impact 3.4.4 of the LUTE Draft EIR, the LUTE includes policies and actions including closing existing sidewalk gaps, building new pedestrian connections, enhancing pedestrian intersection crossings, and enhancing pedestrian comfort level on sidewalks. Impact 3.4.4 related to pedestrian facilities was determined to be less than significant.

The project would include on-site pedestrian and bicycle facilities and connections to local and regional facilities to encourage resident use. Specifically, the project includes a 20-foot-wide, 0.48-acre multi-use public trail from Stewart Drive to Swegles Park along the eastern boundary of the project site. In addition, the project includes short- and long-term bicycle parking facilities, consisting of bicycle racks near the clubhouse and other shared common areas for guests and visitors, as well as bike parking hooks in secured parking garages for residents. Bicycle fix-it repair stations would be installed at the clubhouse and at one location along the trail. Due to the proposed and planned pedestrian and bicycle improvements and project consistency with LUTE policies, no new significant impacts or substantially more severe impacts would occur. The proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required. b) Conflict or be inconsistent with CEQA Guidelines Section 15064.3, subdivision (b)? Introduction
The LUTE EIR concluded that impacts related to traffic operational impacts would be significant and unavoidable with implementation of all feasible mitigation measures. However, pursuant to SB 743, PRC Section 21099, and California Code of Regulations Section 15064.3(a), generally, VMT is the most appropriate measure of transportation impacts and Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-61 a project’s effect on automobile delay no longer constitutes a significant impact under CEQA. Additionally, on June 30, 2020, the Sunnyvale City Council adopted a resolution and Council Policy (Policy 1.2.8, Transportation Analysis Policy) establishing VMT as the primary threshold of significance for analysis of transportation impacts under CEQA. Policy 1.2.8 notes that the City will retain LOS as an operational measurement of intersection efficiency but reiterates that a project’s effect on LOS (i.e., automobile delay) is no longer considered an environmental impact under CEQA. Therefore, the transportation analysis herein evaluates impacts using VMT and does not include LOS analysis.

VMT Methodology
The City of Sunnyvale has developed and adopted VMT guidelines and thresholds (i.e., Council Policy 1.2.8) to meet the state requirements set by SB 743 and to address CEQA Guidelines Section 15064.3. Therefore, the VMT analysis herein primarily relies on the guidance provided in Council Policy 1.2.8 and CEQA Guidelines Section 15064.3. State CEQA Guidelines Section 15064.3(b) identifies four criteria for analyzing the transportation impacts of a project. To determine how the proposed project should be considered, the applicable criteria are discussed below.

Section 15064.3(b)(1) addresses land use projects. The proposed project would be considered a land use project.

Section 15064.3(b)(1) describes that projects with specified proximity to “major” or “high-quality” transit should be presumed to cause a less than significant transportation impact. As defined in PRC Section 21064.3, a “major transit stop” means a site containing an existing rail transit station, a ferry terminal served by either a bus or rail transit service, or the intersection of two or more major bus routes with a frequency of service interval of 15 minutes or less during the morning and afternoon peak commute periods. PRC Section 21155(b) defines a high- quality transit corridor as a corridor with fixed route bus service with service intervals no longer than 15 minutes during peak commute hours. Additionally, Section 15064.3(b)(1) describes that projects resulting in a decrease of VMT in the project area as compared to existing conditions should also be presumed to have a less -than-significant effect.

Section 15064.3(b)(4), Methodology, explains that the lead agency (in this case, the City of Sunnyvale) has discretion to choose the most appropriate methodology to evaluate VMT subject to other applicable standards, such as CEQA Guidelines Section 15151 (standards of adequacy for EIR analyses).

Sunnyvale Council Policy 1.2.8 defines the requirements for VMT analysis by project type, the criteria under which projects are presumed to result in a less-than-significant VMT impact and are not required to analyze it, and the thresholds of significance for determining VMT-based transportation impacts under CEQA. As detailed in Council Policy 1.2.8, a set of criteria is set forth under which conforming projects are assumed to be exempt from preparing a detailed VMT analysis. By virtue of conforming to the exemption criteria, a project would further the City’s goals and policies and would be presumed to result in a less-than-significant impact to VMT. For residential land use projects, Council Policy 1.2.8 established the Countywide Average VMT as the City’s baseline with a VMT reduction threshold set at 15 percent below the baseline to identify potential transportation impacts. The Countywide average (baseline) residential VMT per capita is 13.33, resulting in a VMT threshold of 11.33 (City of Sunnyvale 2021a).

As detailed in State CEQA Guidelines Section 15064.3(b)(1) and Section 2, Exemptions, of Council Policy 1.2.8, small infill projects (i.e., projects generating 110 daily trips or less) should generally be presumed to cause a less- than- significant transportation impact. This exemption criterion is generally consistent with the guidance in the OPR Technical Advisory on Evaluating Transportation Impacts, which states that projects that generate or attract fewer than 110 trips per day generally may be assumed to cause a less-than-significant transportation impact.

Analysis
The LUTE EIR did not include an impact analysis or significance determination related to VMT , as it was not required under CEQA at the time. However, the LUTE EIR did disclose the results of a VMT assessment , which determined that implementation of the LUTE would result in a net increase in total VMT as compared to existing conditions and the 2035 no-project scenario, but a lower countywide VMT per capita as compared to the countywide existing and 2035 no-project scenarios.

A transportation demand management plan was prepared for the project, which outlines a strategy to reduce project-generated VMT and encourage sustainable commuting by project residents (TDM Specialists, Inc. 2025). The plan promotes walking, biking, carpooling, and transit use through providing physical infrastructure, including Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-62 De Guigne Drive Residential Project Environmental Review bicycle/pedestrian access improvements, secure bicycle parking, and on-site bicycle fix-it stations. In addition, the plan outlines programmatic measures, such as retaining an on-site coordinator and maintaining a website to distribute informational materials that encourage residents to use transit, shared rides, walking, and biking.

The project site is located in a high-quality transit corridor and is mapped in area below the City’s 15 percent threshold for residential VMT (City of Sunnyvale 2021a). The per capita VMT associated with existing uses at the project site is 11.5, while the proposed project is anticipated to generate a per capita VMT of 9.32 or 10.35, depending on the types of VMT reductions implemented (TDM Specialists, Inc. 2025). Therefore, the proposed project would reduce per capita VMT in the project area compared to existing conditions. In addition, the proposed project would result in a per capita VMT below the City’s VMT threshold of 15 percent below baseline VMT (i.e., per capita VMT below 11.33). Therefore, the proposed project is exempt from further analysis. For the reasons detailed above, the proposed project would conform to the criteria set forth in Council Policy 1.2.8 for the presumption of a less-than- significant VMT impact for small infill projects and analysis of the project’s VMT confirms that conclusion. Thus, no new significant impacts or substantially more severe impacts would occur. Therefore, the findings of the certified LUTE EIR remain valid and no further analysis is required.
c) Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment)? As identified in Impact 3.4.5 in the LUTE Draft EIR, the LUTE incorporates a “complete streets” approach for circulation planning that accommodates all travel modes. Complete streets are designed and operated to enable safe and convenient access for all users, including pedestrians, bicyclists, and motorists. Additionally, as detailed in Impact

3.4.5, the anticipated circulation improvements in the LUTE would help reduce the potential for pedestrian/bicycle and vehicle conflicts, and all roadway and pedestrian/bicycle facilities would be designed in accordance with City standards. Impact 3.4.5 related to transportation hazards was determined to be less than significant.

Access improvements associated with the proposed project would be constructed in accordance with applicable City of Sunnyvale design and safety standards. Additionally, the project is subject to the City ’s review process, which would ensure that adequate sight distance would be provided at all access points. The project does not propose incompatible uses and services that are inconsistent with the surrounding uses. Therefore, with application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required. d) Result in inadequate emergency access?
As identified in Impact 3.4.6 in the LUTE Draft EIR, the LUTE incorporates a “complete streets” approach for circulation planning that accommodates all travel modes. Complete streets are designed and operated to enable safe and convenient access for all users, including pedestrians, bicyclists, and motorists. Additionally, all improvements associated with the LUTE would be required to meet City of Sunnyvale roadway design standards. Impact 3.4.6 related to emergency access was determined to be less than significant.

Emergency access would be subject to review by the City of Sunnyvale and responsible emergency service agencies, thus ensuring the proposed project would be designed to meet all City emergency access and design standards.

Therefore, adequate emergency access would be provided, and no new significant impacts or substantially more severe impacts would occur. The project does not propose altering any existing or planned emergency access route.

Therefore, with application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, and (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR remain valid and no further analysis is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-63 Mitigation Measures
LUTE EIR Mitigation Measures MM 3.4.7a and 3.4.7b are directed at the City to update its transportation impact fee program to incorporate additional transportation improvements; the measures are not applicable to the proposed project. No additional mitigation measures are required for the project. Nonetheless, the project developer would pay the applicable transportation impact fees.

Conclusion
With application of generally uniformly applied development policies and standards, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the conclusions of the LUTE EIR pertaining to transportation and traffic remain valid.

Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-64 De Guigne Drive Residential Project Environmental Review

4.18 TRIBAL CULTURAL RESOURCES
Environmental Issue Area
Where Impact
Was Analyzed in
LUTE Draft and
Final EIR
Any
Peculiar
Impact?
Any Impact
Not
Analyzed as
Significant
Effect in
LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based
on Substantial
New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

18. Tribal Cultural Resources.

Would the project cause a substantial adverse change in the significance of a tribal cultural resource, defined in Public Resources Code Section 21074 as either a site, feature, place, cultural landscape that is geographically defined in terms of the size and scope of the landscape, sacred place, or object with cultural value to a California Native American tribe, and that is:
a) Listed or eligible for listing in the California
Register of Historical Resources, or in a
local register of historical resources as
defined in Public Resources Code Section
5020.1(k)?
NA NA NA NA NA NA. No project impact
would occur because
no tribal cultural
resources have been
identified in the site.
b) A resource determined by the lead agency,
in its discretion and supported by
substantial evidence, to be significant
pursuant to criteria set forth in subdivision
(c) of Public Resources Code Section
5024.1? In applying the criteria set forth in
subdivision (c) of Public Resources Code
Section 5024.1, the lead agency shall
consider the significance of the resource to
a California Native American tribe.

NA NA NA NA NA NA. No impact would
occur because no tribal
cultural resources have
been identified in the
site.

4.18.1 Discussion and Conclusion
Assembly Bill (AB) 52 (Chapter 532, Statutes of 2014) established a formal consultation process for California Native American tribes as part of CEQA and equates significant impacts on tribal cultural resources with significant environmental impacts (Public Resources Code [PRC] Section 21084.2). AB 52 consultation requirements went into effect on July 1, 2015, for all projects that had not already published a Notice of Intent to Adopt a Negative Declaration or Mitigated Negative Declaration, or published a Notice of Preparation of an Environmental Impact Report prior to that date (Section 11 [c]). Specifically, AB 52 requires that “prior to the release of a negative declaration, mitigated negative declaration, or environmental impact report for a project, the lead agency shall begin consultation” (21808.3.1 [a]), and that “the lead agency may certify an environmental impact report or adopt a mitigated negative declaration for a project with a significant impact on an identified tribal cultural resource only if” consultation is formally concluded (21082.3[d]). The General Plan (LUTE) EIR begun prior to the passage of AB 52. Nevertheless, pursuant to Senate Bill (SB) 18, the City initiated a tribal consultation process. As a result, the City received a letter from the Native American Heritage Commission indicating a records search failed to identify the presence of Native American cultural resources in the immediate project area. The Native American Heritage Commission also provided a list of tribes for the City to contact, which the City did and did not receive additional responses.

In the case of the current project, the lead agency has prepared this checklist to the previously certified LUTE EIR, in accordance with the CEQA Guidelines. A consistency checklist was determined to be the most appropriate document because none of the conditions described in Section 15162, calling for preparation of a subsequent EIR, have occurred. The checklist is consistent with what was previously analyzed under the LUTE EIR. The checklist is not a negative declaration, mitigated negative declaration, or environmental impact report ; therefore, the AB 52 procedures specified in PRC Sections 21080.3. 1(d) and 21080.3.2 do not apply and no additional tribal consultation under AB 52 is required.

Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-65 As discussed in Section 4.5, Cultural Resources, an Archaeological Review was prepared for the project in April 2025 and CHRIS records search request results were received from the Northwest Information Center in December 2024.

Results of both the Archaeological Review and CHRIS records search indicated no recorded cultural resources and low archaeological sensitivity (pre-historic and historic-era) within the project area (Basin 2025, CHRIS 2024).

Mitigation Measures
No mitigation measures pertaining to tribal cultural resources were identified in the certified LUTE EIR, and no additional mitigation measures are required for the project.

Conclusion
With the application of uniformly applied development standards and policies, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. Therefore, the findings of the certified LUTE EIR regarding tribal cultural resources remain valid and no further analysis is required.

Attachment 6

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City of Sunnyvale
4-66 De Guigne Drive Residential Project Environmental Review

4.19 UTILITIES AND SERVICE SYSTEMS
Environmental Issue Area
Where Impact Was
Analyzed in LUTE Draft
and Final EIR
Any
Peculiar
Impact?
Any Impact
Not
Analyzed as
Significant
Effect in
LUTE EIR?
Any
Significant
Off-Site or
Cumulative
Impact Not
Analyzed?
Any Adverse
Impact More
Severe Based
on Substantial
New
Information?
Do EIR Mitigation
Measures or Uniformly
Applied Development
Policies or Standards
Address/Resolve
Impacts?

19. Utilities and Service Systems. Would the project:
a) Exceed wastewater treatment
requirements of the applicable
Regional Water Quality Control
Board?
Draft EIR Setting pp.

3.11-17 to 3.11-19
Impacts 3.11.2.1 and

3.11.2.3 No No No No NA, impact remains
less than significant.
b) Require or result in the relocation or
construction of new or expanded
water, wastewater treatment, electric
power, natural gas, or
telecommunications facilities, the
construction or relocation of which
could cause significant
environmental effects?
Water and wastewater:

Draft EIR Setting pp.

3.11-1 to 3.11-9 and

3.11-17 to 3.11-19
Impacts 3.11.1.2 and

3.11.2.2 Electric power, natural
gas, or
telecommunications
facilities:

Draft EIR Setting pp.

3.11-30 to 3.11-31
Impact 3.11.4.1
No
No
No
No
No
No
No
No
Water and wastewater:

NA, impact remains
less than significant
Electric power, natural
gas, or
telecommunications
facilities:

NA, impact remains
less than significant
c) Require or result in the construction
of new storm water drainage
facilities or expansion of existing
facilities, the construction of which
could cause significant
environmental effects?
Draft EIR Setting pp.

3.8-1 to 3.8-3
Impacts 3.8.1 and 3.8.4
No No No No NA, impact remains
less than significant
d) Have sufficient water supplies available
to serve the project from existing
entitlements and resources, or are new
or expanded entitlements needs?
Draft EIR Setting pp.

3.11-1 to 3.11-9
Impacts 3.11.1.1 and

3.11.1.3 No No No No NA, impact remains
less than significant
e) Result in a determination by the
wastewater treatment provider which
serves or may serve the project that
it has adequate capacity to serve the
project’s projected demand in
addition to the provider’s existing
commitments?
Draft EIR Setting pp.

3.11-17 to 3.11-19
Impacts 3.11.2.2 and

3.11.2.3 No No No No NA, impact remains
less than significant
f) Generate solid waste in excess of
state or local standards, or in excess
of the capacity of local infrastructure,
or otherwise impair the attainment
of solid waste reduction goals?
Draft EIR Setting pp.

3.11-24
Impacts 3.11.3.1 and

3.11.3.3 No No No No NA, impact remains
less than significant
g. Comply with federal, state, and local
statutes and regulations related to
solid waste?
Draft EIR Setting pp.

3.11-24
Impacts 3.11.3.2 and

3.11.3.3 No No No No NA, impact remains
less than significant
Attachment 6

Ascent Environmental Checklist
City of Sunnyvale
De Guigne Drive Residential Project Environmental Review 4-67

4.19.1 Discussion
A water supply assessment (WSA) was prepared that addressed the LUTE as well as the Peery Park Specific Plan and the Lawrence Station Area Plan in accordance with state water planning law. The information about existing and planned supplies, historic and future demand, and supply reliability presented in Section 3.11.1, Water Supply and Service, of the LUTE Draft EIR is taken from the WSA. Since completion of the WSA, the City adopted a 2020 Urban Water Management Plan (UWMP) (City of Sunnyvale 2021b) that is not reflected in the WSA. While there is some variation in the estimates for water demand and supply between the WSA and the 2020 UWMP, both documents conclude that there is adequate water supply for growth anticipated under the Draft LUTE under normal year and drought conditions.

Thus, the 2020 UWMP does not substantially change water supply impact analysis provided in the LUTE Draft EIR. a) Exceed wastewater treatment requirements of the applicable Regional Water Quality Control Board?
Impact 3.11.2.1 in the LUTE Draft EIR evaluated whether implementation of the LUTE would exceed wastewater treatment requirements of the San Francisco Bay RWQCB. The analysis noted that the increase in wastewater flows under the LUTE would be within the permitted design flow capacity of the Donald M. Sommers Water Pollution Control Plant (WPCP) and would be within the design flow capacity assumed in the Water Pollutant Control Plant Master Plan (City of Sunnyvale n.d.). The City would regulate any new industrial or commercial facilities through the pretreatment program. The analysis concluded that implementation of the LUTE would not exceed the requirements, and the impact would be less than significant under project conditions and less than cumulatively considerable under cumulative conditions (Impact 3.11.2.3).

Based on a Sewer Impact Analysis (CBG 2025) that was prepared for the proposed project, the existing uses on the project site generate approximately 30,825 gallons per day (gpd) of wastewater, while the proposed project would generate approximately 49,950 gpd, which is a net increase of 19,125 gpd. During peak wet weather flows, the existing uses on the project site generate approximately 112,511 gpd of wastewater, while the proposed project would generate approximately 169,830 gpd, which is a net increase of 57,319 gpd or 0.0573 million gallons per day (MGD).

The existing 12-inch sewer main in De Guigne Drive has a full flow capacity of 1.15 MGD. Therefore, the net increase in peak wet weather flows of 0.0573 MGD would represent a 5 percent increase in the full flow pipe capacity of the existing sewer main. Although the proposed project would increase wastewater flows compared to existing conditions, the increase would be minimal and no existing downstream capacity issues were identified with respect to the existing sewer main (CBG 2025).

Wastewater flows from the proposed project would be conveyed to the WPCP, which has a design capacity of 29.5 MGD of wastewater per day. Current average flows to the WPCP are around 12 MGD, resulting in a current excess capacity of approximately 17.5 MGD (City of Sunnyvale n.d.). Therefore, the WPCP has sufficient capacity to accommodate the net increase of 0.0573 MGD of wastewater flows generated by the proposed project.

Based on the above discussion, the proposed project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR . The findings of the certified LUTE EIR pertaining to wastewater treatment remain valid and no further analysis is required. b) Require or result in the relocation or construction of new or expanded water, wastewater treatment, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects? Water and wastewater
Impacts 3.11.1.2 and 3.11.2.2 in the LUTE Draft EIR evaluated whether implementation of the LUTE would require the construction of new or expanded water and wastewater infrastructure and treatment facilities. The analysis identified that the City’s wastewater collection system has the capacity to convey sewage and industrial wastes generated when Sunnyvale is fully developed in accordance with the City’s development potential (with an approximately 55.7 million gallons per day [mgd] collection capacity). The City’s Wastewater Collection System Master Plan, Water Master Plan, Attachment 6

Environmental Checklist Ascent
City of Sunnyvale
4-68 De Guigne Drive Residential Project Environmental Review and Capital Improvement Program identify the conveyance improvement projects including improvements to lift stations, pump stations 1 and 2, and pipeline improvements. Wastewater treatment capacity is addressed under item a) above. The LUTE EIR concludes that impacts related to construction of wastewater treatment facilities would be less than significant under project conditions and less than cumulatively considerable under cumulative conditions (Impact 3.11.2.2).

The proposed project could result in a net increase in demand for water and wastewater treatment; however, this increase is within the increase contemplated by the LUTE. As described under item a) above, the existing 12-inch sewer pipeline in De Guigne Drive and the WPCP have sufficient capacity to convey and treat the approximately

0.0573 MGD net increase in peak wet weather wastewater flows generated by the proposed project. Therefore, the increase in wastewater flows attributable to the proposed project would not necessitate the construction of new or expanded sewer or wastewater treatment infrastructure. Total water demand for the proposed project is estimated to be 14,667,432 gallons per year, which is equivalent to approximately 45 acre -feet per year (FirstCarbon Solutions 2025a). The project would include connections to the existing 10-inch water pipelines in De Guigne Drive and Stewart Drive for domestic and fire water service and would not require the construction of new or expanded water facilities.

Landscape water would comply with City and state low-water-use requirements, which would further reduce water demand. Therefore, with the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off -site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR pertaining to the construction or expansion of water or wastewater treatment facilities remain valid and no further analysis is required.

Electric power, natural gas, and telecommunications facilities See Section 4.6, Energy, item b) regarding energy use. The project would connect to existing electrical, natural gas, and telecommunication infrastructure adjacent to the project site. The project is not expected to require offsite improvements to these facilities that could create environmental impacts. c) Require or result in the construction of new storm water drainage facilities or expansion of existing facilities, the construction of which could cause significant environmental effects?
LUTE Draft EIR Impact 3.8.1 evaluated whether buildout under the LUTE would increase impervious surfaces and as a result, alter drainage patterns and increase drainage rates and runoff over existing conditions. The analysis note d that the amount and type of runoff generated by various projects under the LUTE would be greater than that under existing conditions due to increases in impervious surfaces. These impacts would be reduced through compliance with existing regulatory programs, including Sunnyvale Municipal Code Chapter 12.60 and the City’s Urban Runoff Management Plan. Implementation of the LUTE would result in a less-than-significant impact under project conditions and would be less than cumulatively considerable under cumulative conditions (Impact 3.8.4) .

The proposed project is consistent with development assumptions analyzed in the LUTE Draft EIR. As described in Section 2.5.2, “Landscaping,” paved areas would cover approximately 450,000 square feet of the project site, resulting in a net decrease in impervious surfaces from existing conditions. In accordance with applicable regulatory programs related to stormwater management, the project would involve replacement of the existing, outdated on- site stormwater facilities with new on-site LID features, such as bioswales and bioretention basis, that filter stormwater runoff, encourage recharge, and reduce the speed of water flowing into the storm drain system. Therefore, with the application of uniformly applied development standards and policies, the project would have no (1) peculiar impacts, (2) impacts not analyzed in the LUTE EIR, or (3) significant off-site impacts and cumulative impacts not discussed in the LUTE EIR, and (4) there is no substantial new information indicating that an impact would be more severe than discussed in the LUTE EIR. The findings of the certified LUTE EIR pertaining to the construction or expansion of storm water drainage facilities remain valid and no further analysis is required.

Attachment 6