Yountville City Council
January 13, 2026

Town of Yountville
YOUNTVILLE COMMONS PROJECT:

ADDENDUM NO. 1 TO THE

ENVISION YOUNTVILLE GENERAL PLAN UPDATE

ENVIRONMENTAL IMPACT REPORT
December 2025 | Addendum
State Clearinghouse No. 2018082008
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December 2025| Addendum
State Clearinghouse No. 2018082008
YOUNTVILLE COMMONS PROJECT:

ADDENDUM NO. 1 TO THE

ENVISION YOUNTVILLE GENERAL PLAN UPDATE

ENVIRONMENTAL IMPACT REPORT
for the Town of Yountville
Prepared for:

Town of Yountville
Aaron Hecock, Planning and Building Director
6550 Yount Street
Yountville, California 94599
707.944.8851
Prepared by:

PlaceWorks
Contact: Amber Sharpe, Senior Associate
2040 Bancroft Way, Suite 400
Berkeley, California 94709
510.848.3815
[email protected]
www.placeworks.com
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December 2025 i

TABLE OF CONTENTS

1. Introduction ...................................................................................................1-1

1.1 Purpose of the Addendum .................................................................................1-1

1.2 Environmental Procedures .................................................................................1-2

2. Project Description.........................................................................................2-1

2.1 Location and Setting ...........................................................................................2-1

2.2 Background and Existing Conditions...................................................................2-1

2.3 Proposed Project Features..................................................................................2-2

2.4 Required Permits and Project Approvals ............................................................2-8

3. Environmental Analysis ..................................................................................3-9

3.1 Aesthetics.........................................................................................................3-10

3.2 Air Quality.........................................................................................................3-15

3.3 Biological Resources.........................................................................................3-27

3.4 Cultural Resources............................................................................................3-39

3.5 Energy...............................................................................................................3-47

3.6 Geology and Soils .............................................................................................3-52

3.7 Greenhouse Gas Emissions...............................................................................3-57

3.8 Hazards and Hazardous Materials ....................................................................3-62

3.9 Hydrology and Water Quality ...........................................................................3-70

3.10 Land Use and Planning .....................................................................................3-77

3.11 Noise ................................................................................................................3-79

3.12 Population and Housing....................................................................................3-89

3.13 Public Services..................................................................................................3-90

3.14 Recreation ........................................................................................................3-92

3.15 Transportation ..................................................................................................3-93

3.16 Tribal Cultural Resources..................................................................................3-99

3.17 Utilities and Service Systems..........................................................................3-102

3.18 Wildfire...........................................................................................................3-107

3.19 Mandatory Findings of Significance................................................................3-109

4. Conclusion......................................................................................................4-1

4.1 Substantial Changes to the Project.....................................................................4-1

4.2 Substantial Changes in Circumstances................................................................4-1

4.3 New Information ................................................................................................4-1

YOUNTVILLE COMMONS PROJECT
ADDENDUM NO. 1 TO THE ENVISION YOUNTVILLE GENERAL PLAN EIR

TABLE OF CONTENTS
ii PlaceWorks
List of Tables
Table 1-1 General Plan Land Use Development Assumptions....................................1-2 Table 2-1 Project Components...................................................................................2-3 Table 3-1 Construction-Related Criteria Air Pollutant Emissions..............................3-17 Table 3-3 Construction Risk Summary......................................................................3-21 Table 3-4 Construction Risk Summary with Project-Specific Measures....................3-23 Table 3-5 Cumulative Community Risk Summary.....................................................3-24 Table 3-6 Project-Related Construction Noise Levels...............................................3-80 Table 3-7 Project-Related Increases in Traffic Noise, dBA CNEL at 50 Feet..............3-83 Table 3-8 Vibration Impact Levels for Typical Construction Equipment...................3-85

APPENDICES
Appendix A: Air Quality and Greenhouse Gas Emissions
Appendix B: Construction Health Risk Assessment
Appendix C: Biological Resource Assessment
Appendix D: Cultural Resources Report
Appendix E: Geotechnical Investigation Report
Appendix F: Environmental Site Assessments
Appendix G: Noise Data
Appendix H: Transportation Impact Study
In addition to these appendices, all documents cited in this report and used in its preparation are hereby incorporated by reference into this Addendum. Copies of documents referenced herein are available for review at the Town of Yountville, Planning and Building Department, at 6550 Yount Street Yountville, California 94599.

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1. INTRODUCTION
This is an Environmental Impact Report (EIR) Addendum, prepared in accordance with California Environmental Quality Act (CEQA) Guidelines Section 15168.

1.1 PURPOSE OF THE ADDENDUM
The Town of Yountville (Town) has prepared this Addendum to the certified Envision Yountville General Plan Update Environmental Impact Report (Certified EIR), State Clearinghouse (SCH) Number 2018082008. The Yountville Town Council adopted the Envision Yountville General Plan (adopted General Plan) and certified the General Plan EIR in May 2019.

This Addendum has been prepared to document that the project is within the scope of the adopted General Plan covered by the Certified EIR, pursuant to the California Environmental Quality Act (CEQA) Guidelines Section 15168(c), and that none of the conditions described in CEQA Statute (Public Resources Code [PRC]) Section 21166 or CEQA Guidelines (California Code of Regulations [CCR]) Sections 15162 and 15163 that would call for preparation of a subsequent or supplemental EIR has occurred. Pursuant to the provisions of the CEQA Statute and CEQA Guidelines, the Town, acting as the lead agency, is charged with the responsibility of deciding whether to approve the project. This Addendum evaluates the environmental impacts associated with the project.

Certified General Plan EIR
The Town prepared the Certified EIR to evaluate the environmental impacts associated with the implementation of the adopted General Plan. The Certified EIR included a program-level analysis of the environmental impacts of General Plan buildout. Table 1-1, General Plan Land Use Development Assumptions, includes the adopted General Plan development assumptions analyzed in the Certified EIR. Table 1-1 also shows the number of residential units and nonresidential square footage that have been constructed or approved but not yet constructed since the certification of the General Plan EIR, and the remaining development allowed under the adopted General Plan.

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Table 1-1 General Plan Land Use Development Assumptions Type of
Development
Residential
(units)
NonResidential
(sf)
Constructed
Development
(units or sf)
Approved
Development but
not yet Constructed
(units or sf)
Remaining
Development
Potential
Single Family 155 -- 0 10 145 units
Multifamily 76 -- 0 5 71 units
Commercial -- 81,582 0 2,606 78,976 sf
Office -- 21,684 0 0 21,684 sf
Agricultural -- 66,380 0 0 66,380 sf
Total 231 169,646
Note: sf = square feet
The Certified EIR includes a program-level analysis of the following environmental topics:
 Aesthetics and Visual Resources  Hydrology and Water Quality  Agricultural Resources  Land Use
 Air Quality  Noise
 Biological Resources  Population and Housing
 Cultural and Tribal Cultural Resources  Public Services and Recreation  Geology and Soils  Transportation and Circulation
 Greenhouse Gases and Energy  Utilities
 Hazards and Hazardous Materials
The Certified EIR includes General Plan policies and programs that future projects would be required to implement to reduce environmental impacts. As described in the Certified EIR, significant and unavoidable impacts were identified for the topics of agricultural resources, noise, and transportation, but with the implementation of General Plan policies and programs, potential future development over the adopted General Plan 2040 horizon would have no impacts or less-than-significant impacts related to the remaining environmental topics.

1.2 ENVIRONMENTAL PROCEDURES
Pursuant to the CEQA Statute Section 21166, and CEQA Guidelines Section 15162, when an EIR has been certified for a project, no subsequent EIR shall be prepared for the project unless the lead agency determines that one or more of the following conditions are met:

YOUNTVILLE COMMONS PROJECT
ADDENDUM NO. 1 TO THE ENVISION YOUNTVILLE GENERAL PLAN EIR

1. INTRODUCTION
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 Substantial project changes are proposed that will require major revisions of the previous EIR or negative declaration due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects;  Substantial changes would occur with respect to the circumstances under which the project is undertaken that require major revisions to the previous EIR or negative declaration due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects; or  New information of substantial importance that was not known and could not have been known with the exercise of reasonable diligence at the time the previous EIR was certified, or the negative declaration was adopted shows any of the following:
a. The project will have one or more significant effects not discussed in the previous EIR or negative declaration.
b. Significant effects previously examined will be substantially more severe than identified in the previous EIR.
c. Mitigation measures or alternatives previously found not to be feasible would in fact be feasible and would substantially reduce one or more significant effects of the project, but the project proponent declines to adopt the mitigation measures or alternatives. d. Mitigation measures or alternatives that are considerably different from those analyzed in the previous EIR would substantially reduce one or more significant effects on the environment, but the project proponent declines to adopt the mitigation measures or alternatives.

Where none of the conditions specified in CEQA Guidelines Section 15162 are present,1 the lead agency must determine whether to prepare an Addendum or whether no further CEQA documentation is required (CEQA Guidelines Section 15162[b]). An Addendum is appropriate where some changes or additions to the previously Certified EIR are necessary, but there are not any new or substantially more severe significant impacts (CEQA Guidelines Section 15164).

In accordance with the CEQA Guidelines, as demonstrated in Section 2, Project Description, and Section 3, Environmental Analysis, of this Addendum, the Town has determined that an Addendum to the Certified EIR is appropriate for the project. 1 See also Section 15163 of the CEQA Guidelines, which applies the requirements of Section 15162 to supplemental EIRs.

YOUNTVILLE COMMONS PROJECT
ADDENDUM NO. 1 TO THE ENVISION YOUNTVILLE GENERAL PLAN EIR

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2. PROJECT DESCRIPTION

2.1 LOCATION AND SETTING
The 7.7-acre project site is in the town of Yountville, which is in Napa County, California.

Regional access to the site is provided by State Route (SR) 29, approximately 0.2 miles west of the site, and the Silverado Trail, approximately two miles east of the site.

The project site is surrounded by condominiums to the north, Yount Street and single-family residences to the west, Finnell Road, multifamily residences, a hotel, and agricultural uses to the south, and Hopper Creek and townhouses to the east.

2.2 BACKGROUND AND EXISTING CONDITIONS

2.2.1 Site Background Information
Approximately 6.8 acres (Assessor’s Parcel Number [APN] 036-070-026-000) of the site was formerly owned by the Napa Valley Unified School District and was occupied by Yountville Elementary School. The elementary school ceased operations in June 2020. The site was purchased by the Town in June 2024. The remainder of the site consists of the 1.1-acre parcel that accommodates Yountville Town Hall (APN 036-070-025-000). The project would not result in changes to the Town Hall building; however, the Town Hall parcel is a part of the project site due to the need for a lot line adjustment, as explained below. Since acquiring the elementary school site in 2024, the Town has implemented the following changes:
 Installation of a new dog park in the northeast corner of the site.  Conversion of the former school library into Yountville Fit, a privately-owned fitness center that leases the building from the Town.
 Conversion of the former school multipurpose room into the Don and Sally Schmitt Hall, which is a community gathering place where day camps and other Town Parks and Recreation programming take place.
 Restoration of the abandoned school fruit and vegetable plot into a new Farmstand Garden along the northern edge of the site.
 Conversion of the former athletic field snack shack into a café and farmstand that sells locally grown produce, including that grown at the on-site garden.

YOUNTVILLE COMMONS PROJECT
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2. PROJECT DESCRIPTION
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2.2.2 Existing Site Conditions
The project site is generally flat and ranges from approximately 105 to 110 feet above mean sea level (AMSL).

The site is developed with the former elementary school, including the 5,000-square-foot school administration building, the 5,400-square-foot fitness center (formerly the school library), and the 4,500-square-foot Don and Sally Schmitt Hall (formerly a classroom building).

As noted, the site also includes the 5,800-square-foot Town Hall building. The site also accommodates paved surfaces in the parking and playground areas and an unpaved athletic field and open space area (which also accommodates the dog park, farmstand garden, and farmstand). The site contains landscaping, including mature trees, shrubs, and an open field with grass. Some of the trees are protected under the Town’s Tree Protection Ordinance.2 The site currently has General Plan land use designations of Public Facilities and Parks and Playfields and is within the Public Facilities and Parks and Playfields zoning districts.

2.3 PROPOSED PROJECT FEATURES

2.3.1 Key Project Components
The project would include construction of new buildings and recreational areas to accommodate housing, retail, and civic uses. To accommodate this development, the project would involve demolition of the former school administration building. The remaining on-site buildings would be retained and reused.

The project would include subdivision of the site into a total of 18 parcels, which would include a lot line adjustment for the parcel currently accommodating Town Hall. The project would retain Yountville Fit, Schmitt Hall, the Farmstand, and the Farmstand Garden described in Section 2.2.2, Existing Conditions.

The project would include construction of up to 150 multifamily units, distributed across 15 three-story buildings. The units would be rented out through a local preference policy that gives preference to local employees, so the Town expects that most units would be occupied by 2 Trees protected by the Town include Heritage Trees, native oak trees with a trunk that is 10 inches in diameter breast height (DBH), any tree with a 12-inch DBH trunk, or any multi-stemmed perennial plant having an aggregate DBH of 20 inches.

Town of Yountville. Why Trees? Website: https://www.townofyountville.com/DocumentCenter/View/788/TreeProtection--Removal-PDF. Accessed July 24, 2025.

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local employees. The proposed units would primarily be designated for residents that work within the town.

The project would also include up to 1,500 square feet of food-oriented commercial on the ground floor of the three multifamily buildings on the southern portion of the site and up to 1,500 square feet of other local-serving businesses such as dog grooming and training services as well as up to 8,000 square feet of civic and commercial space in three two-story buildings along Yount Street that would accommodate potential uses, such as, but not limited to, a Town archive, small local-serving businesses such as a small garden center, and/or art studios. Table 2-1, Project Components, shows the key components of the project.

Table 2-1 Project Components
Type of Development Existing
To be
Removed New
Project
Total
Multifamily Residential Units 0 0 150 units 150 units
Civic and Commercial Space 20,000 sf 5,000 8,000 sf 23,000 sf Retail 0 0 1,500 sf 1,500 sf
Food-Oriented Service Space 0 0 1,500 sf 1,500 sf
Farmstand 385 sf 0 385 sf 385 sf
Open Space 140,000 sf a 48,100 91,900 sf b 91,900 sf b
Notes. sf = square feet, numbers are rounded
a. Existing open space includes the open field, baseball diamond, outdoor basketball hoops, restrooms, dog park, and community garden.
b. Proposed open space includes outdoor seating areas, lawns, recreation areas, dog park, and pedestrian paths.

In addition, the maximum height of multifamily buildings along Hopper Creek and the civic building along Yount Street would be 40 feet, and the community/laundry building in the center of the project site would have a maximum height of 50 feet.

2.3.2 Open Space, Recreation, and Landscaping
The project would include a variety of open space, recreation, and landscaping components:
 A civic promenade along Yount Street consisting of a paved walkway, trees, and building overhangs.
 An open space area with outdoor seating areas, lawns, and a recreation area at the center of the site.
 An exercise pool adjacent to Schmitt Hall, along with new pool locker rooms to be constructed in the Schmitt Hall building.

YOUNTVILLE COMMONS PROJECT
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 Relocation of the existing dog park to the southeast corner of the site along Finnell Road, adjacent to the existing Hopper Creek Trail.
 A pedestrian path on the northern end of the site to connect to Hopper Creek Trail.

Ground cover, shrubs, and trees would be planted throughout the project site. The project would include new trees and landscaping on-site as well as street trees, all of which would be selected in accordance with the Town’s recommended tree list found in the Yountville Municipal Code (YMC) Section 12.16.110. Additionally, the removal of any trees protected under the Town’s Tree Protection Ordinance would be replaced pursuant to the Ordinance.

Three trees would be removed and transplanted from the Town-owned South Parking Lot along Mulberry Street.

2.3.3 Access and Parking
The project would include retention of the two parking lots currently serving Town Hall, removal of the existing parking lot on the north side of the former elementary school along Yount Street, and construction of a new parking lot on the north side of the site adjacent to the Hopper Creek Condominiums. Parking spaces would be consistent with the YMC.

Vehicles would enter and exit the new parking lots from a driveway entering the site from the site’s northwest corner along Yount Street and the existing curb cut along Finnell Road. The driveway would be consistent with the standards of the YMC. Pedestrians and bicyclists would be able to access the site using the new driveways, sidewalks, and paths connecting to Yount Street, Finnell Road, and Hopper Creek Trail.

The project would include bicycle parking facilities such as bike racks, bike lockers, and secure bike corrals as consistent with adopted General Plan Policy MO-7.3.

The project would include several off-site pedestrian improvements described in Section 2.3.6.

2.3.4 Lighting and Glare
Exterior lighting would be included in the project for the purpose of orienting residents and visitors and for safety along the streets and sidewalks. All permanent on-site lighting would be low-level illumination, downward directed and shielded to reduce light spill or glare into surrounding residences consistent with YMC Chapter 17.132. In landscaped areas, light sources would be concealed. All exterior surface and aboveground mounted fixtures would be complementary to the architectural theme and to the surrounding residential uses.

The project would not include reflective glass, and none of the exterior glass would have a high light reflectance value. The residential units, including any balcony railing elements, would have

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a combination of ultraviolet (UV) coatings, frosting, and fritting to reduce glare and reflections and make the glass visible to birds to reduce collisions.

2.3.5 Utilities

WATER SUPPLY
The project’s potable and fire service water lines would connect to the existing water main in Finnell Road. Any new connections or replaced water lines would not encroach on undisturbed areas. The project would include water conservation features, such as low-flow plumbing fixtures, drought-tolerant landscaping, and irrigation scheduling, as required by State and local regulations.

STORMWATER
The project would remove existing asphalt and paving. The project’s impervious areas would be building roofs and water features such as the fitness pool and surrounding decks; all groundlevel surfaces (parking areas, walkways, and landscaping areas) would consist of pervious materials. The project would reduce impervious areas by approximately 30 percent when compared to existing conditions.

The stormwater currently drains via overland flow to existing catch basins in the paved areas on the project site. An existing 18-inch storm drainpipe on the east side of the site connects to an outfall structure at Hopper Creek. The project would continue to drain to this existing storm drainpipe via roof drains that would be directed to on-site landscape bioretention areas.

Stormwater runoff from the site would be held and treated in the bioretention areas before being discharged. In addition, all parking areas, driveways, and pedestrian walkways would be pervious surfaces such as permeable interlocking concrete pavers or pervious concrete pursuant to the final civil design. Sheet flow to the pervious paving would go to a stone reservoir base in an underdrain system. The project would also include an overflow system with landscape bioretention area overflow connections to a subsurface conveyance system.

Additionally, the project would be subject to a Stormwater Control Plan to be developed prior to project construction and consistent with Town, County, State, and federal stormwater regulations.

SANITARY SEWER SERVICE
Wastewater generated at the project site would be collected by the existing sanitary sewer main on Finnell Road. Wastewater would flow to the Town’s sewer pump station, which would then be pumped to the Yountville Wastewater Reclamation Facility (WRF), which reclaims

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water for use in agriculture, potable water supplies, groundwater replenishment, industrial processes, and environmental restoration.

OTHER UTILITIES
Electric, cable, and telephone service would connect to existing service lines along Yount Street and Finnell Road. Many existing elements from Town-owned infrastructure would remain in place where feasible.

The project would be “all electric,” without any natural gas connections. The project would include solar panels and battery storage at the multifamily residential buildings. Pacific Gas and Electric Company (PG&E) would also supply electricity to the project site via existing infrastructure. The project would provide electric vehicle charging spaces in conformance with the California Green Building Standards Code (CALGreen) voluntary Tier 2 electric vehicle (EV)-Ready Multifamily (Level 2) standards. Additionally, the project will achieve compliance with off-street electric vehicle requirements in the most recently adopted version of CALGreen Tier 2.

SOLID WASTE SERVICES
Solid waste and recycling services would be provided by Upper Valley Disposal and Recycling, which serves the entire town. Waste and recycling trucks would access the site via the driveway coming from Yount Street and collect waste and recycling along the site’s main artery in the parking lots and along the driveway connecting the parking lots. Yountville’s waste is disposed of at the Clover Flat Landfill, while its recycling is handled at the Whitehall Lane Recycle Center.

2.3.6 Off-Site Improvements
The project would include the following off-site improvements:
 Reconstruction of sidewalks on Yount Street and Finnell Road along the project site frontage  Addition of new crosswalks at Webber Street and Yount Street and Humboldt Street and Yount Street
 Installation of a new speed table (traffic calming device like a speed hump that runs traverse to the direction of traffic) at Finnell Road, adjacent to Hopper Creek  Repairing the existing crosswalk, mid-block on Finnell Road, which would connect to the site’s farmstand

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2.3.7 Demolition and Construction
The project would demolish the school administration building and paved areas to make way for the new development. Construction is estimated to begin on April 1, 2026, and the duration for all demolition and construction activities would be phased over 24 months, with all demolition occurring in the first two months. Activities would include site preparation, grading, building construction, landscaping, and paving.

No pile driving, rock blasting, or crushing would occur during the construction phase. Typical equipment to be used during construction of the project would include cranes, forklifts, generator sets, tractors, loaders, backhoes, welders, cement and mortar mixers, pavers, paving equipment, and rollers. The construction site and staging areas would be clearly marked, and construction fencing would be installed as needed to prevent disturbance and safety hazards. A combination of on- and off-site parking facilities for construction workers would be identified during demolition, grading, and construction.

No significant grading is anticipated, although spot grading would be necessary to accommodate buildings and landscaping. No significant soil import or export would be required, although some topsoil would be imported to support new landscaping.

2.3.8 General Plan Land Use and Zoning District
Approximately 4 acres of the 7.7-acre site is currently designated in the Town’s General Plan as Public Facilities, while the remainder of the site is designated as Parks and Playfields. A Creekside Overlay zone overlays the Parks and Playfields zoning district along the eastern edge of the site. The existing site is within zoning districts that reflect the site’s General Plan land use designations.

The project would include a General Plan Amendment and Zoning Amendment to create new General Plan land use designation and zoning district that accommodates the entire project as described in this Addendum. Under the General Plan and Zoning Amendments, the site would have a new General Plan land use designation and zoning district of Commons. The Commons land use designation would primarily be intended for civic and workforce housing uses; other compatible uses would be permitted. The General Plan land use designation would also allow a minimum of eight dwelling units per acre, a maximum 16 units per acre, and a maximum floorarea ratio of 0.25. The project also includes an amendment to General Plan Policy LU-2.5 and Policy LU-2.6 to increase height limits on the project site only to accommodate the proposed height limits as described in this Addendum. The new zoning district would be consistent with the General Plan land use designation.

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2. PROJECT DESCRIPTION
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2.4 REQUIRED PERMITS AND PROJECT APPROVALS
The project would require the Town’s approval of this Addendum to the Certified EIR. In addition, the following discretionary permits and approvals from the Town would be required for the project:
 General Plan Amendment
 Zoning Amendment
 Tentative Map for Subdivision
 Architectural and Site Approval
 Tree Removal Permit
 Demolition Permit(s)
 Grading Permit(s)
 Building Permit(s)
 Encroachment Permit(s) for off-site work in the
public right-of-way.
 Certificate(s) of Occupancy
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3. ENVIRONMENTAL ANALYSIS
This chapter assesses the project in regard to all topics required under CEQA. For each topic, it provides an excerpt from the environmental checklist included in CEQA Guidelines Appendix G, Environmental Checklist Form. It then summarizes the conclusions of the Certified EIR and assesses the conditions described in CEQA Guidelines Section 15162 that would trigger preparation of a subsequent EIR.

In each case, this Addendum finds that the conditions triggering preparation of a subsequent EIR would not occur. This Addendum documents that the project would not result in any new significant environmental impacts, an increase in the severity of significant impacts previously identified and studied in the Certified EIR, or require the adoption of any new or considerably different mitigation measures or alternatives.

This Addendum has been prepared to satisfy the requirements of CEQA Guidelines Sections 15164. Mitigation measures referenced are from the Certified EIR and are modified as appropriate.

While the Certified EIR relied on the CEQA Guidelines Appendix G, Environmental Checklist Form, that was in place prior to December 2018 and a new version of this checklist now exists, changes in laws, regulations, or guidelines are not “new information” as that term is used in CEQA Guidelines Section 15162, provided that information about newly required issues was known at the time the original EIR was certified. As described in this chapter, information about each of the newly required environmental topics and questions were known at the time the Envision Yountville General Plan EIR was certified. Accordingly, this Addendum is the appropriate form of environmental review for the project.

There are no agricultural, forestry, or mineral resources on the project site. Therefore, the project would not result in a new, significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to these topics and as such, they are excluded from the discussion that follows.

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3.1 AESTHETICS
Except as provided in PRC Section 21099, would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum?
a) Have a substantial adverse effect on a scenic vista? LTS Yes b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway?
LTS Yes
c) In nonurbanized 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?
LTS Yes
d) Create a new source of substantial light or glare which would adversely affect day or nighttime views in the area? LTS Yes Key: LTS = less than significant
Note: With respect to criterion (c), PRC Section 21071, Urbanized Area Definition, has several metrics by which a town can be defined as an urban area. PRC Section 21071(a)(2) states that a town can be classified as an urban area if the town has a population of less than 100,000 people and if the population of that town, and not more than two contiguous incorporated cities combined, equals at least 100,000 persons. According to the U.S. Census, the 2025 population estimates for the Town of Yountville is 3,308 residents. There are no cities that are contiguous to Yountville; therefore, Yountville is considered a nonurbanized area under PRC Section 21071 and impacts of potential future development in Yountville are based on part two of the question regarding whether a project would substantially degrade the existing visual character or quality of public views of the site and its surroundings.

DISCUSSION
The Certified EIR found that the adopted General Plan would have a less-than-significant impact on scenic vistas, would have a less-than-significant impact on the substantial degradation of the existing visual character of the town, and would in a less-than-significant impact on increased light and glare. The Certified EIR identified that Napa County does not have an officially designated State Designated Scenic Highway.

The Certified EIR describes scenic vistas as views provided from the cemetery along the town’s northern limits as a scenic vista and view corridors as north to south view corridors looking north along Washington, Jefferson, and Yount Streets and east to west corridors looking west from Oak Circle and Creek and Webber Streets and looking east along Finnell Road and Mulberry Street. The project site is on Yount Street and Finnell Road. The project would be behind the current Town Hall buildings and set back from Yount Street consistent with Policy LU-

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3. ENVIRONMENTAL ANALYSIS
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2.3. Therefore, the project would not block or obstruct any views of the cemetery or the identified view corridors along Yount Street. The view corridor along Finnell Road where the project would be is currently partially obstructed with mature trees. Therefore, while the project would be visible from Finnell Road looking north, it would not obstruct views of hillsides to the east. The Certified EIR recognizes that new development within the General Plan area has the potential to interrupt views of the surrounding foothills, hillsides, and agricultural lands from numerous vantage points within Yountville. As previously described, the proposed buildings would be set back from Finnell Road and Yount Street and would be surrounded by a mature tree canopy and as such, would not interrupt views of the foothills, hillsides, and agricultural lands. Accordingly, the project would be in an area of town where it would not have a substantial effect on a scenic vista or view corridor.

The project would be in the developed area of Yountville. The project has been designed to be compatible with the surrounding neighborhood and Town Hall setting. As stated in Section

2.3.1, the maximum height of multifamily buildings along Hopper Creek and the civic buildings along Yount Street would be 40 feet, and the community/laundry building in the center of the project site would have a maximum height of 50 feet. The project would be fully landscaped with new trees, and replacement trees consistent with YMC Section 17.98.130. Accordingly, the project and would not substantially degrade the existing visual character and quality surrounding Yountville.

The changes to the light environment from the project would be considered typical of suburban areas, consistent with the findings of the Certified EIR. The project would be required to comply with the Town’s Outdoor Lighting Ordinance, which requires that all outdoor lighting fixtures be designed, installed, and directed to prevent glare, light trespass, and light pollution. As stated in Section 2.3.4, the exterior lighting would be for the purpose of orienting residents and visitors and for safety along the streets and sidewalks and all permanent on-site lighting would be lowlevel illumination, downward directed, and shielded to reduce light spill or glare into surrounding residences. In landscaped areas, light sources would be concealed, and all exterior surface and aboveground mounted fixtures would be complementary to the architectural theme and to the surrounding residential uses. The project would not include reflective glass, and none of the exterior glass would have a high light reflectance value. The residential units, including any balcony railing elements, would have a combination of UV coatings, frosting, and fritting to reduce glare and reflections and make the glass visible to birds to reduce collisions.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in table, the project would be consistent with the applicable mitigating General Plan policies and program identified in Chapter 3.1, Aesthetics, of the Certified EIR.

YOUNTVILLE COMMONS PROJECT
ADDENDUM NO. 1 TO THE ENVISION YOUNTVILLE GENERAL PLAN EIR

3. ENVIRONMENTAL ANALYSIS
3-12 PlaceWorks
Policy Consistency Finding
Policy LU-2.1 Compatibility of Development.

Require that new development, remodels, and
additions be of a scale, intensity, and design that
integrates with the immediate neighborhood,
the town as a whole, and the natural
surroundings.

Yes. The project would be set back from Yount
Street, Finnell Road, and from residences to the
north and east, and would be within the scale of
the surrounding mature tree canopy. While the
project would range in height from 35 to 50 feet,
the surrounding housing is primarily 20 to 25 feet
with surrounding tree canopy of 30 to 50 feet. The
project’s building materials and roof styles will be
similar to the existing surrounding development.

Therefore, the project’s design and scale would be
compatible with the existing neighborhood and
development within the town.

Policy LU-2.3 Setbacks. Provide building setback
along streets, pedestrian and bike paths, and
easements for proposed new development and
additions.

Yes. The proposed buildings would be set back
from Yount Street, Finnell Road, and adjacent
residential properties to the north. The project
would also be set back from the pedestrian path
along Hopper Creek to the east. Therefore, the
project would not substantially impact public
views from surrounding areas.

Policy LU-2.4 Building Massing. Require use of
massing techniques that mitigate heavy or bulky
forms (such as modulating building mass, partial
upper stories, setbacks for upper story volume,
variety of roof forms), building placement that
does not obstruct view corridors, and building
design that is compatible with adjacent
structures to ensure that new buildings do not
overwhelm their sites or their neighborhoods.

Yes. The project would be consistent with Chapter

17.40, Residential Design Standards and
Guidelines, and YMC Chapter 17.72, NonResidential and Mixed-Use Design Standards, pertaining to building scale and massing and roof
forms. For example, in compliance with YMC
Chapter 17.40, multifamily unit facades without
doors, that are visible from Yount Street or Finnell
Road, will be less than 30 feet in length. The
project site is not within a view corridor identified
on General Plan Figure OS-2. The nearest view
corridor starts at Finnell Road, immediately east of
Vista Drive, approximately 400 feet east of the site.

Policy LU-2.5 Maximum Building Height. Permit
two-story buildings. All buildings shall adhere to
the requirements for massing in Policy LU-2.4.

Yes. Although the project’s building heights are not
consistent with the current Policy LU-2.5, the
project would comply with the proposed
amendment to Policy LU-2.5. The amendment text
will identify that two-story buildings are permitted
provided that additional stories may be allowed in
accordance with Policy LU-2.6. The project site
would have a General Plan land use designation of
Commons and would be consistent with the
heights allowed in the proposed amendment to
Policy LU-2.6.

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ADDENDUM NO. 1 TO THE ENVISION YOUNTVILLE GENERAL PLAN EIR

3. ENVIRONMENTAL ANALYSIS
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Policy Consistency Finding
Policy LU-2.6 Consideration of Limited ThreeStory Building Elements. The Town is open to consideration of limited three-story building
elements on the west side of Washington Street
between Mulberry and Humboldt Streets and on
the west side of Highway 29 between California
Drive and Humboldt Street as shown in Figure
LU-1. Three-story buildings will be considered
only if a significant portion of the project and its
uses provide a community benefit
such as affordable housing and/or underrepresented businesses and services that provide an opportunity for resident use. Such
buildings shall not exceed 35 feet at the highest
point, shall adhere to the requirements for
massing in Policy LU-2.4, shall be stepped-back,
located near the center of the development, and
avoid flat, vertical planes and three-story
development fronting Washington or other
streets or highways, and shall address parking
requirements and placement. Three-story
elements are discretionary and not a matter of
right.

Yes. Although the project’s building heights are not
consistent with the current Policy LU-2.6, the
project would comply with the proposed
amendment to Policy LU-2.6. The amendment to
the General Plan Policy LU-2.6 would include text
that states that buildings in the Commons land use
designation may exceed these height and story
limits.

With the approval of the General Plan
Amendment, the project would have Commons
General Plan land use designation. The project
would include three-story buildings with a
maximum height of 50 feet above the ground
surface. The three-story multifamily buildings
would include affordable housing and would
primarily be in the eastern portion of the project
site. The site would be surrounded by landscaping,
including trees, which is consistent with visual
character of the project area. The project would
provide affordable housing, which is considered a
community benefit. The project will be consistent
with building massing requirements described in
General Plan Policy LU-2.4.

Policy LU-2.5 Maximum Building Height. Permit
three-story buildings only to the west of
Washington Street between California Drive and
Humboldt Street on the condition that the
project and its uses will provide a community
benefit such as affordable housing, non–food or
non–wine retail, standalone office, or services.

Permit two-story buildings for the remainder of
town. All buildings shall adhere to the
requirements for massing in Policy LU-2.4.

Yes. The project includes an amendment to the
adopted General Plan to create a new land use
designation and to this policy to allow three-story
multifamily buildings on the project site to
accommodate the housing that would be on the
eastern portion of the project site. Although the
site is to the east of Washington Street, the project
would be set back from Yount Street and Finnell
Road. The site would be surrounded by
landscaping, including trees, which is consistent
with visual character of the project area. The
project would provide affordable housing, which is
considered a community benefit. The project will
be consistent with building massing requirements
described in General Plan Policy LU-2.4.

Policy LU-2.10 Natural Grade. Prohibit raising
the natural grade in excess of that necessary for
adequate drainage.

Yes. The project would not significantly raise or
lower the project site relative to existing grade.

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Policy Consistency Finding
Policy LU-5.1 Scale of Development. Require
new residential development, remodels, and
additions to avoid a design approach that
exaggerates height, bulk, or mass or results in
design that is not compatible with neighboring
properties.

Yes. Refer to Policy LU-2.4. The project would be
consistent with YMC Chapter 17.40, Residential
Design Standards and Guidelines, pertaining to
building massing and scale. The existing
surrounding residences are up to two stories.

Although the proposed multifamily residences
would be up to three stories (i.e., up to 50 feet
above grade), the proposed residences would be
set back from the streets and residential property
lines and compatible with neighboring properties.

Policy LU-6.9 Integrate Natural Beauty. Ensure
that all new development, remodels, and
additions include an appropriate landscape
buffer between building and street. The goal is
to soften the building edge and avoid an
overemphasis on hardscape.

Yes. The project would have landscaping, including
trees along the perimeter of the site that would
serve as a buffer between the proposed
development and Finnell Road as well as Yountville
Street. The project would have unpaved open
space areas, outdoor community lawn areas, and a
dog park.

Policy OS-3.1 Scenic Views. Maintain the scenic
beauty of Yountville and protect view corridors
from the Town towards the surrounding
vineyards and mountains.

Yes. Views of hillsides to the east are partially
visible from Finnell Road. The views of the hillsides
to the east are limited from Yount Street given that
existing development and landscaping currently
blocks views of these hillsides. The project is not
within or adjacent to a view corridor and would
not block views from these corridors.

Program OS-3.1a Existing View Corridors.

Require all new development to maintain
existing view corridors shown in Figure OS-2
View Corridors. These include: North view
corridors, including Washington, Jefferson, and
Yount Streets and Stags View Lane; and East
view corridors, including Lande Way, Mount
Avenue extension, Forrester Lane, Finnell Road,
Heritage Way, Mulberry Street, and Oak Circle;
and West view corridors, including Creek Street
extension, Webber Street, driveway south of V
Marketplace, Mulberry Street extension, and
Oak Circle extension.

Yes. Based on General Plan Figure OS-2, the
nearest view corridor is on Finnell Road, east of
Vista Drive, approximately 400 feet east of the site.

The project would not be within or adjacent to an
existing view corridor; therefore, the project would
not impact views for these existing corridors.

Policy HO-1.3 Multifamily Design. Encourage
the design of multifamily units to integrate with
the Town’s character.

Yes. See Policies LU-2.4 and LU-5.1.

YOUNTVILLE COMMONS PROJECT
ADDENDUM NO. 1 TO THE ENVISION YOUNTVILLE GENERAL PLAN EIR

3. ENVIRONMENTAL ANALYSIS
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CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to aesthetics.

3.2 AIR QUALITY
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum?
a) Conflict with or obstruct implementation of the applicable air quality plan? LTS Yes
b) Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard? LTS Yes
c) Expose sensitive receptors to substantial pollutant
concentrations? LTS Yes
d) Result in other emissions (such as those leading to odors) adversely affecting a substantial number of people? LTS Yes Key: LTS = less than significant

DISCUSSION
Consistency with Applicable Air Quality Plan
The Certified EIR concluded that the adopted General Plan would result in less-than-significant impacts with respect to conflicts with an applicable air quality plan. The Certified EIR identified the Bay Area Air District (formerly the Bay Area Air Quality Management District) 2017 Clean Air Plan: Spare the Air, Cool the Climate (2017 Clean Air Plan) as the applicable air quality plan for Yountville. The Certified EIR noted that the 2017 Clean Air Plan contains 85 individual control measures that describe specific actions to reduce emissions of air and climate pollutants from emission sources. The Certified EIR found that an increase in criteria air pollutants and other emissions would occur from future project construction activities, and from the future operation of residences, businesses, and other land uses in the town of Yountville. Although it was determined that these emissions could interfere with the Air District’s San Francisco Bay Area Air Basin (SFBAAB) attainment of state and national air quality standards, the Certified EIR concluded that compliance with the adopted General Plan policies and programs that were established to reduce potential air pollutant emissions and sensitive receptors’ exposure to toxic air contaminants, would ensure that future development supports the primary goals of the 2017 Clean Air Plan, and would not disrupt the implementation of or conflict with the 2017 Clean Air Plan.

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Similarly, the project would comply with the adopted General Plan policies and programs listed in this section under the subheading “Mitigating Policies and Programs Applicable to the Project,” which would support the 2017 Clean Air Plan goals to reduce air pollutant emissions and impacts to public health. Therefore, the project would not disrupt the implementation of or result in a conflict with the 2017 Clean Air Plan; as a result, the impact would be less than significant.

Criteria Air Pollutants and Applicable Air Quality Standards Construction Criteria Pollutant Emissions
The Certified EIR recognized that General Plan buildout would result in short-term construction criteria pollutant emissions. In addition, the Certified EIR concluded that although the Air District does not maintain recommended plan-level thresholds of significance for construction emissions, the Air District does maintain and recommend project-level thresholds that potential future development would be subject to. The Certified EIR indicated that future projects would be required to implement the Air District’s Basic Construction Measures/Best Management Practices (BMPs) to reduce construction fugitive dust emissions levels and comply with adopted General Plan Open Space and Conservation Element policies and programs that reduce construction emissions. Therefore, the Certified EIR concluded that future development under the adopted General Plan would not result in a cumulatively considerable net increase in construction criteria pollutant emissions.

The San Francisco Bay Area (including the town of Yountville) is within a State-designated nonattainment for ozone and fine particulate matter (PM10 and PM2.5), and is designated unclassified or attainment for all other criteria pollutants, as stated in the Certified EIR.3 The project’s construction activities would generate combustion emissions from various sources, such as on-site heavy-duty construction vehicles, vehicles hauling materials to and from the site, and motor vehicles transporting the construction crew. Fugitive dust emissions (PM10 and PM2.5) would mainly be caused by construction activities that disturb soil or generate debris, such as demolition and grading activities. Air pollutant emissions from construction activities on-site would vary daily as construction activity levels change. Estimates of construction emissions associated with construction of the project are shown in Table 3-2, ConstructionRelated Criteria Air Pollutant Emissions. 3 “Attainment” status for a pollutant means that the Air District meets the standard set by the U.S. Environmental Protection Agency (federal) or California Environmental Protection Agency (state).

Bay Area Air District. 2025, November 5. Air Quality Standards and Attainment Status. https://www.baaqmd.gov/en/about-air-quality/research-and-data/air-quality-standards-and-attainment-status.

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Table 3-1 Construction-Related Criteria Air Pollutant Emissions Construction Phase
Pollutants (tons/year) a

ROG NOX
Fugitive
PM10
b
Exhaust
PM10
Fugitive
PM2.5
b
Exhaust
PM2.5
Project
2026 <1 2 <1 <1 <1 <1
2027 <1 1 1 <1 <1 <1
2028 <1 1 <1 <1 <1 <1
Total Construction Emissions 1 3 1 <1 <1 <1
Pollutants (average lbs./day) a
Average Daily Construction
Emissions c
3 13 4 <1 1 <1
Air District’s Average Daily ProjectLevel Threshold54 54 Implement BMPs
82 Implement
BMPs
54 Significant? No No No No No No
Source: CalEEMod, Version 2022.1.

Notes: Highest winter or summer emissions are reported (see Appendix A, Air Quality and Greenhouse Gas Emissions, of this Addendum); BMP = Best Management Practices; NA = not applicable; emissions may not total to 100% due to rounding; shading represents the fugitive dust component of the emissions that are mitigated through the Air District’s BMPs.
a. Construction modeling assumed a 24-month construction duration, based on the schedule provided by the Town. Where specific information regarding project-related construction activities was not available, construction assumptions were based on CalEEMod defaults, which are based on construction surveys conducted by South Coast Air Quality Management District of construction equipment and phasing for comparable projects.
b. Includes implementation of BMPs for fugitive dust control required by the Air District. Implementation of the Air District’s construction BMPs is considered to result in construction-related fugitive dust emissions that are acceptable.
c. Average daily emissions are based on the construction emissions divided by the total number of active construction days. The total number of construction days is estimated to be 523 days.

Table 3-1 shows that criteria air pollutant emissions from construction equipment exhaust would not exceed the Air District’s average daily thresholds of significance for construction criteria pollutants. Further, pursuant to Program OS-7.1d, which requires appropriate measures to be implemented to address short-term (e.g., construction) air quality impacts, the Air District construction BMPs to reduce fugitive dust emissions will be implemented.

In compliance with Program OS-7.1d, the following project-specific measure is required to be implemented during construction.

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Project-Specific Measures Pursuant to Program OS-7.1d: The Bay Area Air District construction BMPs will be implemented by the Town or the Town’s contractor prior to and during construction:
 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 transportation soil, sand, or other loose material off-site shall be covered.  All visible mud or dirt track-out 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 miles per hour  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.
 Idling times shall be minimized either by shutting equipment off when not in use or reducing the maximum idling time to 5 minutes (as required by the California airborne toxics control measure 13 CCR 2485). Clear signage shall be provided for construction workers at all access points.
 All construction equipment shall be maintained and properly tuned in accordance to manufacturer’s specifications. All equipment shall be checked by a certified mechanic and determined to be running in proper condition prior to operation.  Post a publicly visible sign with the telephone number and person to contact at the Lead Agency regarding dust complaints. This person shall respond and take correction active within 48 hours. The Air District’s phone number shall be visible to ensure compliance with applicable regulations.

Pursuant to the Air District, the implementation of BMPs reduce the construction-related fugitive dust emissions to a less-than-significant level. With implementation of the Air District’s construction BMPs and compliance with adopted General Plan Program OS-7.1d, the project would not result in a cumulatively considerable net increase of any construction criteria pollutant for which the region is in nonattainment under an applicable federal or state ambient air quality standard.

Operational Criteria Pollutant Emissions
The Certified EIR concluded that long-term criteria pollutant emissions would result from the operation of potential residential, retail, light industrial, commercial, and institutional uses supported by the adopted General Plan. The Certified EIR also indicated that development of future projects within the General Plan area would be subject to the Town’s standard CEQA

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review process and would be required to assess project-specific emissions in relation to the Bay Area Air District’s significance thresholds.

The primary source of long-term criteria air pollutant emissions generated by the project would be mobile emissions from project-generated vehicle trips. Section 4.1 of the Air District’s Guidelines recommends that projects with multiple land use types use the Mixed-Use Screening Tool for Criteria Pollutants and Precursors to determine whether operational emissions would exceed the applicable significance thresholds.
4 Accordingly, the Air District’s Screening Tool was
used in lieu of a full calculation of operational criteria pollutant emissions. For projects that fall below the Air District’s screening criteria, it can be reasonably concluded that operational emissions would not exceed the applicable Air District operational thresholds. Because the project does not exceed these screening criteria for residential, retail, and commercial uses, its operational emissions would not exceed the Air District’s operational thresholds (screening results provided in Appendix A, Air Quality and Greenhouse Gas Emissions, of this Addendum).

In addition, emissions from building energy use would be reduced because the new buildings would be designed all-electric and exceed the current Building Energy Efficiency Standards and CALGreen standards for energy efficiency. These standards would be an improvement over the energy standards applied to the future development under the adopted General Plan. Given the project would be all-electric and comply with or exceed the most recent building standards, the project would support the adopted General Plan Program OS-7.1d and Policy OS-8.1 by including strategies to improve on-site energy efficiency and to reduce operational air pollutant emissions. For these reasons and consistent with the Certified EIR conclusions, operation of the project would not result in a substantial increase in operation-phase emissions compared to what was analyzed in the Certified EIR.

Carbon Monoxide Hotspots
Since the Certified EIR was a programmatic analysis and project-specific information was not available to analyze carbon monoxide hotspots (CO), the following evaluation uses the Air District’s 2022 CEQA Air Quality Guidelines to assess potential CO hotspot impacts to nearby sensitive receptors.
5 Areas of vehicle congestion have the potential to create pockets of CO, called hotspots. These pockets have the potential to exceed the State 1-hour standard of 20 parts per million (ppm) or the 8-hour standard of 9.0 ppm. Because CO is produced in the greatest quantities from vehicle 4 Air District. 2023, April 20. California Environmental Quality Act Air Quality Guidelines. https://www.baaqmd.gov/?sc_itemid=CDA5FAE5-BBDC-4337-A10C-5648BCD2D71F. 5 Air District. 2023, April 20, California Environmental Quality Act Air Quality Guidelines. https://www.baaqmd.gov/?sc_itemid=CDA5FAE5-BBDC-4337-A10C-5648BCD2D71F.

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combustion and does not readily disperse into the atmosphere, adherence to applicable Ambient Air Quality Standards (AAQS) is typically demonstrated through an analysis of localized CO concentrations. Hotspots are typically produced at intersections, where traffic congestion is highest because vehicles queue for periods of time and are subject to reduced speeds. A project would need to increase traffic volumes at a single intersection to more than 44,000 vehicles per hour, or 24,000 vehicles per hour where vertical and/or horizontal mixing is substantially limited, to generate a significant CO impact.
6 Based on turning movement volumes provided by W-Trans, the intersection of Yount Street and Washington Street near the project site is projected to experience approximately 532 AM peakhour vehicle trips and 503 PM peak-hour vehicle trips at buildout year (see Appendix G, Transportation Impact Study, of this Addendum). Accordingly, the addition of project-generated trips to existing traffic volumes would remain below the Air District’s recommended hourly screening criteria. Thus, the project would not introduce additional vehicle trips that could result in a CO hotspot when combined with existing traffic volumes. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to CO hotspots.

Sensitive Receptors and Health Risks
The Certified EIR recognized that implementation of General Plan policies and programs intended to minimize exposure of toxic air contaminants (TACs) to sensitive receptors would limit air pollution during construction and operational activities within the town and its surrounding environment, consistent with the Air District recommendations intended to reduce health risks associated with TACs. The Certified EIR stated that future development under the adopted General Plan would be subject to all applicable adopted General Plan policies and programs that provide protections for risks associated with TACs, including Policy OS-7.2 and Program OS-7.2a (see Table 3-3). The Certified EIR indicated that implementation of these adopted General Plan policy and program would ensure that mitigation measures and BMPs are incorporated to minimize the potential for TACs to impact sensitive receptors within the town.

The Certified EIR concluded that with the implementation of the applicable adopted General Plan policies and programs, future development under the adopted General Plan would result in less-than-significant impacts related to the exposure of sensitive receptors to air pollutant concentrations.

Project impacts related to increased health risk can occur by generating emissions of TACs and air pollutants. Construction activity under the project will generate dust and equipment exhaust that can affect nearby sensitive receptors. The closest existing sensitive receptors to the project site are the adjacent condominiums to the north and the Bardessono Hotel and Spa to the 6 Air District. 2023.

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south along Finnell Road. Thus, in compliance with adopted General Plan Program OS-7.2a, a construction health risk assessment (HRA) has been prepared for the project (see Appendix B, Construction Health Risk Assessment, of this Addendum) to assess potential air quality impacts to sensitive receptors. The results of the construction HRA are based on the maximum sensitive receptor concentration over the approximately 24-month construction exposure period for offsite receptors, assuming 24-hour outdoor exposure, and averaged over a 30-year lifetime. Risk is based on the updated Office of Environmental Health Hazard Assessment (OEHHA) Guidance for the Maximally Exposed Receptor (MER) of each receptor type (e.g., residential, worker) within 1,000 feet of the project site. The project’s maximally exposed receptor (MER) is identified as the sensitive receptor that is most impacted by the project’s construction. The residential MER is approximately 50 feet north of the project site and the worker MER is approximately 100 feet south of the project site at the Bardessono Hotel and Spa. Table 3-3, Construction Risk Summary, summarizes the maximum cancer risks, PM2.5 concentrations, and health Hazard Index for construction-related activities.

Table 3-3 Construction Risk Summary
Receptor
Cancer Risk
(per million) Chronic Hazards
PM2.5
(µg/m3)
MER – Resident 29 <0.1 0.35
MER – Worker <1 <0.1 0.17
Air District Significance Threshold 10 1.0 0.30
Significant? Yes No Yes
Source: Lakes AERMOD View, Version 13.0.0. (see Appendix B, Construction Health Risk Assessment, of this Addendum)
Notes: Cancer risk calculated using 2015 OEHHA HRA Guidance Manual. Bold = exceeds threshold. MER = maximally exposed receptor.

As shown in Table 3-3, cancer risk for the residential MER from the project-related construction emissions was calculated to be approximately 29 in one million and the worker MER to be less than one in one million. Therefore, the residential MER would experience a cancer risk that exceeds the Air District’s significance threshold of 10 in one million and the worker MER would be below the significance threshold. Consequently, cancer risks experienced by nearby receptors would not be within acceptable limits.

For non-carcinogenic effects, the chronic hazard index identified for each toxicological endpoint equaled less than one for each identified receptor. Therefore, chronic non-carcinogenic hazards are within acceptable limits. The annual average PM2.5 concentration at the residential MER would reach 0.35 µg/m3 and the worker MER would reach 0.17 µg/m3. Therefore, the residential MER would experience an annual average PM2.5 concentration that would exceed Air District’s significance threshold of 0.30 µg/m3. Because the cancer risk and annual average PM2.5 concentration for the residential MER would exceed the Air District’s significance

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thresholds during the project’s construction, the project-related construction activities could expose sensitive receptors to substantial TAC concentrations.

Therefore, consistent with adopted General Plan Policy OS-7.2 and Program OS-7.2a, which requires projects to minimize exposure of sensitive receptors to concentrations of air pollutant emissions and the Town staff to ensure mitigation measures and best management practices are implemented to reduce significant emissions of criteria pollutants to the greatest extent feasible, project-specific measures will be implemented as required. The following projectspecific measure requires the Town to use US Environmental Protection Agency (USEPA)- approved construction equipment that reduce diesel exhaust air pollutant emissions (including particulate matter).

In compliance with Program OS-7.2a, the following project-specific measure is required to be implemented during construction.

Project-Specific Measures Pursuant to Program OS-7.2a: The Town shall specify in the construction bid that the project construction contractor(s) and subcontractor(s) comply with the following requirements for all off-road equipment used over the entire duration of the construction activities at the site:
 Use engines that meet either US Environmental Protection Agency or California Air Resources Board (CARB) Tier 4 Final emission standards for engines that are greater than 25 horsepower. Ensure that all construction plans submitted to the Town’s Planning and Building Department clearly show the selected emission reduction strategy for construction equipment over 25 horsepower.
 If Tier 4 Final equipment is not available for use for a specific piece of off-road construction equipment, documentation shall be provided to the Town demonstrating that such equipment is not available for the project. If Tier 4 Final equipment is not available, the construction contractor(s) and subcontractor(s) affected shall use Tier 4 Interim equipment instead. If Tier 4 Interim equipment is not available for use for the project for a specific piece of off-road construction equipment, documentation shall be provided to the Town demonstrating that such equipment is not available for the project. If Tier 4 Interim equipment is not available, the construction contractor(s) and subcontractor(s) affected shall use Tier 3 equipment outfitted with a level 3 diesel particulate filter instead.

Table 3-4, Construction Risk Summary with Project-Specific Measures, shows the cancer risk, chronic hazard index, and PM2.5 concentrations, with the implementation of project-specific measures, at the MER.

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Table 3-4 Construction Risk Summary with Project-Specific Measures Receptor
Cancer Risk
(per million)
Chronic Hazard
Index
PM2.5
(µg/m3)
MER – Resident 8.73 <0.1 0.24
Air District’s Significance Threshold 10 1.0 0.30
Significant? No No No
Source: Lakes AERMOD View, Version 13.0.0. (See Appendix B, Construction Health Risk Assessment, of this Addendum)
Notes: Cancer risk calculated using 2015 OEHHA HRA Guidance Manual. Bold = exceeds threshold. MER = maximally exposed receptor.

Assumes project-specific measures that require off-road diesel-powered construction equipment over 25 horsepower to meet USEPA Tier 4 Final emissions standards or higher. Modeling conservatively includes Tier 4 Interim engines.

Table 3-4 shows that with implementation of project-specific measures pursuant to adopted General Plan Program OS-7.2a, cancer risk, chronic hazard index, and PM2.5 concentrations, which result from the project’s construction emissions, would be below the Air District’s significance thresholds at the residential MER. Therefore, the project would not expose off-site sensitive receptors to substantial concentrations of air pollutant emissions during construction at the residential MER.

Types of land uses that typically generate substantial quantities of criteria air pollutants and TACs include industrial (stationary sources), manufacturing, and warehousing (truck idling) land uses. While the project operation may involve temporary idling from delivery vehicles, the severity of the potential impact would be nominal as these types of major air pollutant emissions sources (e.g., warehouses) are not included as part of the project. The project would not include stationary sources that emit TACs and would not generate a significant amount of heavy-duty truck trips (a source of diesel particulate matter). Therefore, the project would not expose sensitive receptors to substantial concentrations of air pollutant emissions during operation, and impacts would be less than significant.

Consistent with the Certified EIR conclusions, with the implementation of adopted General Plan policies and project-specific measures pursuant to Programs OS-7.1d and OS-7.2a to reduce air pollutant emissions, the project would result in a less-than-significant impact with respect to the exposure of sensitive receptors to air pollutant emissions generated by the project.

Cumulative Health Risks
The Certified EIR concluded that with the implementation of adopted General Plan policies and programs in the Open Space and Conservation Element, which have a goal to reduce air pollutant emissions, the exposure of sensitive receptors to substantial pollutant concentrations,

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the adopted General Plan buildout would result in a less than cumulatively considerable contribution to an air quality impact.

The Air District recommends assessing the potential cumulative impacts from sources of TACs within 1,000 feet of a project, in addition to addressing these impacts for an individual project.

The existing TACs that the Air District recommends a cumulative analysis be completed for include permitted stationary sources, marine sources, roadway sources, rail sources, and highway sources. Risks from permitted stationary sources within 1,000 feet of the project site were identified using the Air District’s Stationary Source Screening Map. 7 Risks from roadway
and rail sources are released periodically from the Air District in the form of risk assessment screening tools (RAST), which were used in determining associated risks at the residential MER during the project’s construction period.
8 The residential MER was used in the cumulative
community risk assessment as it represents the greatest impact to nearby receptors during project construction.

Table 3-5, Cumulative Community Risk Summary, summarizes the existing TAC source risks at the residential MER from project construction emissions in combination with existing TAC sources within 1,000 feet of the project site.

Table 3-5 Cumulative Community Risk Summary
Source Source Type
Distance
to MER a
Cancer Risk
(per million)
Chronic
Hazards
PM2.5
(µg/m3)
Project Impacts
Project Construction with
Project-Specific Measures
Pursuant to Program OS7.2a b
Diesel
Construction
Equipment
N/A 9 <0.1 0.24
Permitted Stationary Source Impacts
Pacific Bell (Facility ID
13559)
Generator 870 <1 <0.1 <0.1
Town of Yountville-Yountville
Town Hall (Facility ID 22240)
Generator 540 <1 <0.1 <0.1
Roadway & Highway Impacts
Air District provided
roadway values c
Vehicles N/A 5 <0.1 0.10
Rail Impacts
7 Air District, 2025, Stationary Source Screening Map. 8 Air District, 2025, Stationary Source Screening Map.

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Table 3-5 Cumulative Community Risk Summary
Source Source Type
Distance
to MER a
Cancer Risk
(per million)
Chronic
Hazards
PM2.5
(µg/m3)
Air District provided rail
values c
Rail N/A <1 <0.1 <0.1
Cumulative Health Impacts
Cumulative Project Health Impacts 14 <0.1 0.34
Air District’s Significance Threshold 100 10.0 0.80
Significant? No No No
Source: Appendix B, Construction Health Risk Assessment, of this Addendum.

Notes: N/D = No Data; N/A = Not Applicable; Bold = exceeds threshold. a. Values expressed in feet. Residential MER is a residence adjacent to the southwestern project boundary. b. Includes project-specific measures pursuant to Program OS-7.2a, which requires that off-road diesel-powered construction equipment over 25 horsepower to meet USEPA Tier 4 Final emissions standards or higher.

Modeling conservatively includes Tier 4 Interim engines. c. Air District-provided values correspond with risks experienced at the residential MER.

Table 3-5 shows the project’s construction emissions with Tier 4 Interim equipment incorporated combined with existing TAC emissions within 1,000 feet would not exceed the Air District’s cumulative community health risk significance thresholds at the residential MER location. Pending and approved projects within 1,000 feet of the MER would be required to comply with the Town’s adopted General Plan programs and policies and the Air District’s guidelines to reduce operational TAC emissions. Consistent with the Certified EIR conclusions, the project would not result in a substantial increase in cumulative health-risk impacts to sensitive receptors (air pollutant emissions) compared to the adopted General Plan, analyzed in the Certified EIR.

Odor Emissions
The Certified EIR identified a less-than-significant impact associated with the generation of substantial odors that would affect a substantial number of people. The type of facilities that are typically considered to have objectionable odors include wastewater treatment plants, compost facilities, landfills, solid waste transfer stations, fiberglass manufacturing facilities, paint/coating operations (e.g., auto body shops), dairy farms, petroleum refineries, asphalt batch plants, chemical manufacturing, and food manufacturing facilities. As discussed in Chapter 2, Project Description, the project would replace the former school administration building with a mixed-use development featuring 150 multifamily units, groundfloor retail/restaurant space, three two-story buildings for local-serving businesses and civic/commercial space, which for a conservative analysis is assumed to potentially include food-oriented services, and associated surface improvements. Therefore, the proposed mixeduse development is not a type of land use that would generate substantial odors affecting a significant number of people and would comply with Policy OS-7.2, which would minimize the public’s exposure to odors.

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During construction activities on the project site, construction equipment exhaust and application of asphalt and architectural coatings would temporarily generate odors. Any construction-related odor emissions would be temporary and intermittent. Additionally, noxious odors would be confined to the immediate vicinity of the construction equipment. By the time such emissions reach any sensitive receptor sites, they would be diluted to well below any level of air quality concern. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to odors.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.3, Air Quality, of the Certified EIR.

Policy or Program Consistency Finding
Program OS-7.1b Air Quality Management
District. Support the Bay Area Air Quality
Management District’s plans and programs to
improve air quality.

Yes. The project would comply with the Air
District’s CEQA Air Quality Guidelines during
construction by implementing the Air District’s
Basic Control Measures and project-specific
measures to reduce emissions below the Air
District’s thresholds. In addition, the proposed
development’s size and number of units are below
the Air District’s screening thresholds for
operational emissions.

Program OS-7.1d Air Quality Impact of New
Development. Review development projects to
ensure compliance with the current regional air
quality plan and to ensure that appropriate
measures are implemented to address both
short-term (e.g., construction) and long-term
(e.g., operational) air quality impacts.

Yes. As shown in the analysis in this section, the
project’s compliance with the 2017 Clean Air Plan,
construction (short-term), and operational (longterm) criteria pollutant emissions, and short-term and long-term health risk impacts from exposure
to TACs and construction dust, with
implementation of the Air District’s mandatory
construction BMPs, was completed as a part of
this Addendum.

Policy OS-7.2 Air Quality Impacts to Sensitive
Receptors. Minimize exposure of sensitive
receptors to concentrations of air pollutant
emissions, toxic air contaminants, and odors.

Yes. As described in the analysis, implementation
of project-specific measures would reduce the
project’s impact from construction air pollutant
emissions and TACs to a less-than-significant level.

The proposed construction and land uses would
generate substantial odors that would significantly
affect sensitive receptors.

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Policy or Program Consistency Finding
Program OS-7.2a Project Review. Review all
development projects for potential air quality
impacts to residences, congregate housing,
schools, and other sensitive receptors, including
impacts associated with exposure to toxic air
contaminants for proposed development located
within the Community Risk and Hazard (Toxic Air
Contaminants) Overlay Zone associated with
State Route 29 (see Figure OS-8). Staff shall
ensure that mitigation measures and best
management practices are implemented to
reduce significant emissions of criteria pollutants
to the greatest extent feasible.

Yes. The project site is not within the Community
Risk and Hazard (Toxic Air Contaminants) Overlay
Zone, associated with State Route 29, shown on
General Plan Figure OS-8. As described in the
analysis, a construction health risk assessment was
completed to evaluate the impact of the project’s
air pollutant emissions on sensitive receptors. The
project will implement project-specific measures
that reduce the impacts of construction emissions
on sensitive receptors to a less-than-significant
level.

Policy OS-8.1 Conserve Energy and Use
Renewable Energy. Increase energy efficiency
and conservation and encourage the use of
renewable energy.

Yes. The project will be all-electric and will not
include natural gas use (which would result in less
air pollutant emissions). The project will comply
with the most recent CALGreen standards, which
increase energy efficiency and reduce emissions.

Program OS-8.1a Design of Buildings. Encourage
the design of new buildings and remodel of
existing buildings with consideration of reducing
the environmental impacts and costs of heating,
cooling, and lighting through the use of efficient
mechanical equipment, solar orientation, natural
light and airflow, and shade trees.

Yes. The project will include the planting of new
trees to provide shading. The proposed buildings
include energy-efficient heating and cooling
systems and mechanical equipment.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to air quality.

3.3 BIOLOGICAL RESOURCES
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum?
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 U.S. Fish and Wildlife Service?
LTS Yes

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Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum?
b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the California Department of Fish and Wildlife or U.S. Fish and Wildlife Service?
LTS Yes
c) Have a substantial adverse effect on state or federally protected wetlands (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means?
LTS Yes
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?
LTS Yes
e) Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? LTS Yes 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?
NI Yes
Key: NI = no impact; LTS = less than significant

DISCUSSION
Special-Status Species
The Certified EIR recognized that construction and maintenance activities associated with future development under the adopted General Plan could result in the direct and indirect loss or indirect disturbance of special-status plant or wildlife (i.e., mammal, bird, amphibian, or reptile) species or their habitats. The Certified EIR concluded that implementation of the Town’s adopted General Plan mitigating policies and programs, including Program OS-5.4b, which requires preparation of a Biological Resources Assessment (BRA) to address project-related impacts to special-status species, as well as adopted federal, State, and local regulations that are aimed to protect special-status species, future development would have less-thansignificant impacts on special-status species and their habitat.

Special-Status Plant Species
In compliance with Program OS-5.4b, a BRA was completed for the project. The BRA includes a record search of the California Department of Fish and Wildlife’s (CDFW’s) California Natural Diversity Database (CNDDB), together with other relevant information, which indicates that

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occurrences of numerous plant and animal species with special status have been recorded from or are suspected to occur in the Napa Valley vicinity.

The CNDDB records search showed the distribution of known occurrences of six special-status plant species within about a three-mile radius of the site. These consist of Jepson’s coyotethistle (Eryngium articulatum), Jepson’s leptosiphonepson (Leptosiphon jepsonii), Sebastopol meadowfoam (Limnanthes vinculans), Sonoma beardtongue (Penstemon newberryi var. sonomensis), Sanford’s arrowhead (Sagittaria sanfordii), and Napa bluecurls (Trichostema ruygtii). These species have a California Rare Plant Rank of 1B (rare, threatened, or endangered in California and elsewhere) according to the California Native Plant Society (CNPS) in their electronic Inventory of Rare and Endangered Plants of California. Sebastopol meadowfoam is the only species with formal listing status, listed as endangered under the federal Endangered Species Act (FESA) and California ESA.

Based on the results from the project’s BRA and a review of special-status plant species documented for the region as a part of the Certified EIR, given the extent of past disturbance associated with the previous school facilities and ongoing open space use, there is no potential for special-status plant species to occur on the site. The narrow band of riparian habitat along Hopper Creek has been routinely managed as part of former school facilities and native groundcover species have been replaced by non-native species at the site. Suitable seasonal wetland and marsh habitat conditions necessary to support vernal pool and other aquaticdependent species are absent along the creek channel. Based on these existing conditions, no special-status plant species have been reported and are not anticipated to occur on the site.

Therefore, there is no suitable habitat for special-status plant species at the project site or adjacent to the site, the project would not have a substantial adverse effect on any specialstatus plant species, and this impact would be less than significant.

Special-Status Animal Species
The BRA record search showed the distribution of known occurrences of five special-status animal species within about a three-mile radius of the site. These species consist of occurrences of northwestern pond turtle (Actinemys marmorata), California giant salamander (Dicamptodon ensatus), white-tailed kite (Elanus leucurus), foothill yellow-legged frog (Rana boylii), and Cowan’s amphipod (Stygobromus cowani), and designated critical habitat for steelhead along the Napa River and northern spotted owl observations in the woodland and forest habitat to the west of Napa Valley. A habitat suitability analysis was completed during the field reconnaissance survey conducted as part of the BRA, and the potential for the occurrence of any special-status species known or expected to occur in the Yountville vicinity was evaluated.

Surface flows in the Hopper Creek segment adjacent to the site are seasonal; the creek segment adjacent to the site does not provide suitable breeding habitat or allow for permanent occupation for aquatic-dependent special-status invertebrates, fish, amphibians, and reptiles

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known from the Napa Valley, including steelhead, western pond turtle, Cowan’s amphipod, California giant salamander, foothill yellow-legged frog, and the federally threatened California red-legged frog. Based on the records search, there is a potential for occasional dispersal of the red-legged frog in Hopper Creek since individuals can be flushed downstream during winter storms or move along the creek in search of suitable habitat when surface flows are present.

The project would be outside of the creek corridor’s setback area (except for the proposed graveled pedestrian path that would be adjacent to the existing path) and would comply with best management practices and National Pollutant Discharge Elimination System (NPDES) requirements that would reduce the amount of runoff from the site (refer to Riparian Habitat/Sensitive Natural Communities and Wetlands discussion below). Therefore, the project would not result in a substantial adverse impact on aquatic-dependent special-status species.

Special-Status Bird Species
Given the extent of past disturbance associated with the previous school facilities and ongoing open space use, there is limited potential for special-status animal species to occur on most of the site. However, the mature trees and seasonal aquatic habitat along Hopper Creek provide foraging and possibly roosting, nesting, and dispersal habitat for native wildlife and may be used by a number of special-status animal species. Most of these species are native bird species that are relatively common and are protected under the federal Migratory Bird Treaty Act (MBTA) and California Fish and Game Code, such as great egret (Ardea alba), great blue heron (Ardea Herodias), white-tailed kite (Elanus leucurus), sharp-shinned hawk (Accipiter striatus), and Cooper’s hawk (Astur cooperii), as well great horned owl (Bubo virginianus), red-shouldered hawk (Buteo lineatus), and red-tailed hawk (Buteo jamaicensis). A full list of bird species that could occur along the Hopper Creek corridor is provided in Appendix C, Biological Resources Assessment, of this Addendum. No signs of any large stick raptor nests or staining from longterm roosting were observed during the field reconnaissance survey, and use of the riparian corridors and remaining ruderal grasslands on the site may be limited to occasional foraging by these species, although new nests or roost locations could be established in the future.

Based on the MBTA regulations, if a project could impact native or migratory bird species and/or cause the loss or degradation of native/migratory bird habitat, and such work cannot occur outside the nesting season, the U.S. Fish and Wildlife Service (USFWS) recommends that the impacted portions of a project area be surveyed to determine if migratory birds are present and nesting. Construction in proximity to nests in active use could lead to nest abandonment, unless appropriate seasonal restrictions are implemented. Destruction of bird nests in active use or activities that could lead to nest abandonment would be a violation of the MBTA and California Fish and Game Code.

Adopted General Plan Policy OS-5 requires projects to protect biological resources, including migratory birds, and threatened and endangered species. In addition, adopted General Plan Program OS-5.4b requires BRAs to include mitigation measures, if necessary, to reduce impacts

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to special-status species identified by the CDFW or USFWS. In compliance with the MBTA regulations and adopted General Plan policies and programs to protect native and migratory bird species during construction, the following project-specific measure will be implemented to reduce the project’s impacts on special-status species birds and active nests.

In compliance with Program OS-5.4b, the following project-specific measure is required to be implemented if construction occurs between September 1 and February 28.

Project-Specific Measures Pursuant to Program OS-5.4b (Nesting Bird Survey): If project construction is scheduled to occur between September 1 and February 28, which is considered to be outside of the nesting bird season in Napa County, impacts to nesting birds will not occur. If construction occurs between February 1 and August 31, the following conditions of approval would avoid impacts to active nests shall be implemented:

A survey for active bird nests will be conducted by a qualified biologist no more than seven days prior to the start of project activities (vegetation removal, grading, tree removal, building demolition or other initial ground-disturbing activities) if they commence during the nesting season (March 1 through August 31). The survey shall be conducted to determine whether any active nests are present that could potentially be directly or indirectly affected by project activities. Active nests must be protected until any young have fledged and are no longer dependent on the nest. Upon completion of the surveys, any nests discovered shall be avoided through a work exclusion buffer determined by a qualified biologist to avoid impacts. Buffers will be sufficiently large and long in duration such that nest abandonment is avoided. The qualified biologist will determine the buffer based on the species and the type of disturbance anticipated to result from project activities.

With the implementation of the project-specific measure, which would protect special-status bird species, bird species protected under the MBTA, and their habitats during tree removal and construction, the project would not have a substantial adverse effect on special-status bird species.

Special-Status Bat Species
Pallid bat (Antrozous pallidus) and Townsend’s big-eared bat (Corynorhinus townsendii) are known to roost in a variety of habitats, including abandoned buildings and tree cavities. The western red bat (Lasiurus blossevillii) typically roosts in forest and riparian woodlands, including snags and trees with moderately dense canopies. The existing buildings on the site are well maintained and show no signs of access by bats; however, there is a potential for roosting in the larger trees adjacent to the Hopper Creek riparian corridor where trunk cavities, exfoliating bark, and dense foliage for both special-status and more common bat species. Tree removal and

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construction disturbance in the immediate vicinity of an active bat roost could affect specialstatus bats and other more common bats, if present. Direct impacts on bats could occur if construction activities resulted in direct mortality or the disruption or abandonment of an active bat roost. Anticipated impacts on bat foraging and movement opportunities would be minimal, as the mature trees adjacent to Hopper Creek would be retained.

In compliance with Program OS-5.4b and recommendations in the BRA, the following projectspecific measure is required to be implemented prior to and during construction.

Project-Specific Measure Pursuant to Program OS-5.4b (Roosting Bats Survey): The Town or the Town’s contractor shall conduct a roosting survey within seven days prior to initial tree removal and construction to determine whether any active roosts are present that must be protected until any young have fledged and are no longer dependent on the roost. Protection of the roost, if present, will require a qualified biologist to provide construction setbacks, with the setbacks depending on the type of bat species and the degree to which the individuals have acclimated to ongoing disturbance.

With implementation of the Program OS-5.4b project-specific measure, which would protect special-status bat species and their habitats during tree removal and construction, the project would not have a substantial adverse effect on special-status bat species.

The project would have a less-than-significant impact on special-status species with respect to individuals and their habitat modifications, with the implementation of the project-specific measures. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to special-status species.

Riparian Habitat/Sensitive Natural Communities and Wetlands The Certified EIR determined that future development would have the potential to result in significant impacts to protected habitats (including riparian habitats) and federally or state protected wetlands and that compliance with the mitigating General Plan policies and programs, in conjunction with existing federal and State regulations protecting riparian habitat/ sensitive natural communities and protected wetlands, would ensure that this impact is reduced to a less-than-significant level.

CDFW tracks the occurrences of special plant communities that are either known or believed to be of high priority for inventory in the CNDDB. Based on the project’s BRA, these sensitive natural communities are ranked according to rarity and listed online in the VegCAMP program of the CNDDB. Based on NatureServe’s Heritage Methodology, natural communities with a State Rank of 3 or less are considered sensitive. The oak-dominated riparian woodland along Hopper Creek is classified as Valley Oak Riparian Forest and Woodland alliance. This riparian woodland

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community type along Hopper Creek has a State Rank of 3 and qualifies as a sensitive natural community type.

The eastern edge of the site is within the Creekside Overlay zone, which is the Hopper Creek setback area measured 35 feet from the centerline of the creek and not less than 10 feet from the creek bank. The Valley Oak Riparian Forest and Woodland alliance community is within this setback area. The project would comply with adopted General Plan Policy OS-5.2, which encourages consideration of native vegetation preservation during development review. No trees within the riparian setback area would be removed, and the construction of structures, walls, or fences would not occur within this setback area, in compliance with YMC Chapter

17.76 C, Creek Overlay. A graveled path would be added on the west side of the existing pedestrian path, away from the creek, to avoid impacts to the riparian habitat area. Given the project would comply with mitigating General Plan Policy OS-5.2 and the YMC setback requirements for Creekside Overlay areas, the project would not result in a substantial adverse effect on Hopper Creek riparian habitat or any sensitive natural community. Therefore, consistent with the Certified EIR, the project would have a less-than-significant impact on riparian habitat and sensitive natural communities.

Wetlands are recognized as important features on a regional and national level due to their inherent value to fish and wildlife, use as storage areas for storm and floodwaters, and water recharge, filtration, and purification functions. Jurisdiction of the US Army Corps of Engineers (Army Corps) is established through provisions of Section 404 of the Clean Water Act, which prohibits the discharge of dredged or fill material into “waters of the US” without a permit.

Projects with water features under Regional Water Quality Control Board (RWQCB) jurisdiction require certification or waiver to control discharges into waters of the State. CDFW’s jurisdiction over wetland areas requires permits for activities that could disrupt the natural flow or alter the channel, bed, or bank of any lake, river, or stream. Hopper Creek is considered a water of the State and is under the RWQCB and CDFW’s jurisdiction.

There are no wetlands within the project site. Based on the preliminary wetland assessment completed as a part of the BRA field reconnaissance survey, Hopper Creek, approximately 50 feet east of the site, is the only regulated wetland near the site. The project would not require removal or fill of Hopper Creek. In compliance with mitigating General Plan Programs OS-6.4a and OS-6.4b (described below), the project would include the addition of pervious surfaces and bioretention/treatment areas to reduce the volume of stormwater runoff and the amount of polluted runoff from the project site that could enter the creek (refer to Section 3.9, Hydrology and Water Quality, of this Addendum). Compliance with these programs will reduce impacts to the creek/wetland due to pollution and sedimentation that causes hydrological interruption.

Since the project will comply with mitigating General Plan policies and programs that protect Hopper Creek, the project would not have a substantial adverse effect on a protected wetland, and the impact would be less than significant. Thus, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in

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the Certified EIR related to wetlands, riparian areas, or sensitive natural communities, identified in the Certified EIR.

Wildlife Movement Corridors and Wildlife Nursery Sites
The Certified EIR acknowledged that a CNDDB record search completed from the General Plan area and that the record search did not show in documented wildlife corridors or wildlife nursery sites. The Certified EIR also recognized that Hopper Creek could provide movement habitat for a limited variety of wildlife species. The Certified EIR concluded that future development has the potential to result in significant impacts to protected wildlife movement corridors and with the implementation of the mitigating policies and programs, as well as federal and State regulations to protect movement corridors, impacts to wildlife movement would be reduced to a less-than-significant level.

The project site is surrounded by roadways and residential development to the north, west, and south, and Hopper Creek to the east. Residential development is also immediately to the east of Hopper Creek. Based on the CNDDB record search completed for the project site and area, the site and Hopper Creek were not identified as a protected wildlife movement corridor or a native wildlife nursery site. However, native and non-native trees and shrubs along the Hopper Creek corridor provide temporary/seasonal foraging, perching, and nesting opportunities for specialstatus birds; therefore, it is possible that native bird species could move along the creek corridor. Given that steelhead and other anadromous fish have been reported from the Napa River and tributary drainages, there is a remote possibility that individuals could move along the Hopper Creek corridor during wet weather and periods of prolonged seasonal flows. Pacific chorus frogs, western toad, and possibly foothill yellow-legged frog could use the aquatic habitat along the project reach of Hopper Creek when surface water is present, likely moving to locations with permanent water as the creek dries out in the summer and early fall months.

Since the project would be surrounded by development, set back from Hopper Creek, and would preserve the native vegetation (that could serve as foraging and nesting opportunities for native or migratory bird species) along the creek corridor, in compliance with mitigating Program OS-2.3a, and Policies OS-5.2 and OS-5.3, the project would not interfere with the movement of wildlife species along the Hopper Creek corridor. With implementation of these mitigating General Plan programs and policies, the project would not interfere substantially with the movement of native resident migratory fish or wildlife species, and the impact is less than significant. The project would not result in a new, significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR with respect to wildlife and aquatic fish movement.

Tree Protection
The Certified EIR determined that future development would be required to comply with mitigating General Plan policies, as well as the YMC, pertaining to the protection of trees and

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that impacts related to conflicts with local policies and ordinances protecting biological resources, such as trees, were identified as less than significant.

Trees along the Hopper Creek corridor mostly consist of mature native trees, including valley oaks, coast live oaks, black walnut, and California buckeye. Scattered mature and sapling oaks occur along the Finnel Road frontage and the fenced northern property line of the site, many growing with the cyclone fencing. Non-native trees in the immediate vicinity of the former school building and parking lots include Monterey pines, crape myrtle, Raywood ash, coast redwood, tan oak, olive, fruitless mulberry, ironbark eucalyptus, and London plane.

The project would comply with YMC Chapter 17.128, Tree Preservation and Management, for the removal of trees. The Town defines a protected tree as follows:
 A heritage tree identified in the Heritage Tree Survey;  Any native oak tree with a trunk that measures 10 inches diameter at breast height (DBH) (equal to 31 inches in circumference) or more;
 Any tree with a trunk that measures 12 inches DBH (equal to 38 inches in circumference) or more or a multi-stemmed perennial plant having an aggregate DBH of 20 inches (equal to 63 inches in circumference) or more;
 A tree shown to be preserved on an approved development entitlement or specifically required by the Town Council or Zoning and Design Review Board to be retained as a condition of approval of an entitlement; or
 A tree required to be planted as a replacement tree.

Pursuant to YMC Section 17.128.050, the Town’s consulting arborist shall prepare an arborist report for review and use by the Town’s Planning and Building Department. Adopted General Plan Policy 5.1 and Program OS-5.1a requires projects to regulate the removal, cutting, and other activities detrimental to trees, and require the replanting of replacement trees as feasible.

Program OS-5.1b requires projects to identify and protect heritage trees that warrant additional tree protection measures to best manage and maintain a healthy urban forest.

In compliance with YMC Chapter 17.128 and General Plan Policy 5.1 and Programs OS-5.1a and OS-5.1b, the following project-specific measure is required to be implemented prior to construction.

Project-Specific Measure Pursuant to YMC Chapter 17.128 and General Plan Policy 5.1 and Programs OS-5.1a and OS-5.1b: The Town’s consulting arborist shall prepare an arborist report for review and use by the Town’s Planning and Building Department in reviewing the application and making decisions and findings pursuant to YMC Section 17.128.060. The arborist report shall identify the size, species, and location of trees on-site. The arborist report shall also identify which trees are protected under the Town’s ordinance and require replacement or payment of in-lieu fees.

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YMC Chapter 17.128 also requires measures to be implemented, such as establishing a tree protection zone prior to construction, to reduce impacts to trees designated for preservation.

With the implementation of the project-specific measure that reduces impacts to trees, the project would not conflict with a tree preservation policy or ordinance, and the impact would be less than significant. The project would not result in a new, significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to conflicting with the Town’s regulations for the protection of trees.

Habitat Conservation Plan or Natural Community Conservation Plan The Certified EIR recognized that the General Plan area is not subject to an adopted habitat conservation plan or natural community conservation plan and that implementation of the adopted General Plan would have no impact with respect to with an adopted habitat conservation plan or natural community conservation plan.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.4, Biological Resources, of the Certified EIR.

Policy or Program Consistency Finding
Policy OS-2.2 Existing Open Space. Preserve and
protect existing open space areas, including
parks, trails, greenways and Hopper Creek,
shown in Figure OS-1 Parks and Open Space
Areas.

Yes. The project will preserve Hopper Creek,
approximately 50 feet east of the site by
complying with YMC Chapter 17.76 C. Creekside
Overlay, riparian corridor setback criteria and
implementing General Plan Programs OS-6.4a and
OS-6.4b (see Section 3.9, Hydrology and Water
Quality) by including best management practices
and NPDES requirements to reduce the impacts of
the project on water quality.

Policy OS-2.3 Natural Watercourses. Protect and
maintain existing natural watercourses.

Yes. See Policy OS-2.2.

Program OS-2.3a Hopper Creek. Maintain the
existing watercourse of Hopper Creek and native
vegetation within its bank and along its frontage.

Yes. See Policies OS-2.2 and OS-2.3. The project
will not remove native vegetation, including native
oak trees, along the Hopper Creek frontage. The
project will comply with YMC Chapter 17.128,
which requires measures that shall be
implemented, prior to and during construction, to
protect trees designated for preservation.

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Policy or Program Consistency Finding
Policy OS-5.1 Tree Planting. Encourage the
planting and preservation of trees to provide
shade, promote wildlife habitat, and benefit the
air quality and beauty of Yountville.

Yes. The project will include the planting of new
trees throughout the site, including the planting of
street trees. Replacement trees will be planted in
accordance with the Town’s tree replacement
standards outlined in YMC Chapter 17.128.

Program OS-5.1a Tree Management. Continue
to regulate the removal, cutting, and other
activities detrimental to trees, and require the
replanting of replacement trees as feasible.

Yes. See OS-5.1. The removal of trees on-site will
be in accordance with the Town’s tree
requirements for removal of protected trees. The
project will prepare an arborist report that
identifies protected trees and which trees require
replacement.

Program OS-5.1b Heritage Trees. Continue to
identify and protect heritage trees that warrant
additional tree protection measures to best
manage and maintain a healthy urban forest.

Yes. The project is required to comply with the
YMC and prepare an arborist report to confirm
which trees are considered heritage trees on the
site. The project will comply with measures to
protect heritage trees provided in YMC Chapter

17.128.

Policy OS-5.2 Preservation of Native
Vegetation. Encourage preservation of native
vegetation during the development review.

Yes. The project will preserve native oak trees
along the eastern edge of the site, adjacent to
Hopper Creek. The project will implement
measures in YMC Chapter 17.128 to protect trees
designated for preservation.

Policy OS-5.3 Native Riparian Vegetation.

Protect and preserve native vegetation adjacent
to Hopper Creek and Beard Ditch during
construction.

Yes. See Policy OS-5.2.

Policy OS-5.4 Species Diversity and Habitat.

Protect biological resources, including migratory
birds, threatened and endangered species,
sensitive and riparian habitat, wildlife movement
corridors, nursery sites, and open space, that are
necessary to maintain a diversity of plant and
animal species.

Yes. The project will protect biological resources,
including special-status bird and bat species, by
implementing project-specific measures pursuant
to the recommendations the BRA and General Plan
programs. The project will comply with YMC
Chapter 17.76 C, Creekside Overlay, riparian
corridor setback criteria and would not result in
significant impacts to these habitats.

Program OS-5.4b Species and Sensitive Habitat
Analysis. Require development and
infrastructure projects to address potential
impacts to special-status species and sensitive
habitats, including sensitive natural
communities, wetlands, vernal pools, waters of
the U.S, and wildlife migration corridors. Prior to
approval, a Biological Resources Assessment
shall be completed for the project site that
Yes. A BRA was completed for the project (see
Appendix C, Biological Resource Assessment, of
this Addendum). The BRA and this Addendum
identify the existing conditions related to
biological resources and addresses impacts these
resources, such as special-status species, sensitive
natural communities, and wetlands. The BRA
includes recommendations to reduce impacts to

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Policy or Program Consistency Finding
evaluates the potential for biological resources
(including any plant or animal species identified
as a candidate, sensitive, or special-status
species in local or regional plans, policies, or
regulations, or by the California Department of
Fish and Wildlife or U.S. Fish and Wildlife
Service) and sensitive habitats to be found on
the subject site or affected by the project. The
Biological Resources Assessment shall include
mitigation measures, if necessary, to reduce
impacts to the associated species and/or
habitats.
special-status species, including special-status bird
and bat species.

Policy OS-6.4 Water Quality. Protect water
resources from pollution and sedimentation.

Yes. See Policy OS-2.2.

Program OS-6.4a Best Management Practices.

Require new development, redevelopment, and
infrastructure projects to implement best
management practices as feasible, including lowimpact development techniques, the minimal use of non-pervious surfaces in landscape
design, and the integration of natural features
into the project design, to naturally filter and
biodegrade contaminants and to minimize
surface runoff into drainage systems and creeks.

Yes. See Policy OS-2.2 and Section 3.9, Hydrology
and Water Quality, of this Addendum. The project
will include best management practices, such as
pervious surfaces, inclusion of bioretention/
treatment areas, and landscaping.

Program OS-6.4b NPDES Compliance. Ensure
that new development, redevelopment, and
infrastructure projects comply with the
requirements of the National Pollutant
Discharge Elimination System (NPDES) permit
and the applicable Stormwater Discharge System
Ordinance and do not substantially degrade
water quality.

Yes. See Program OS-6.4a. The project will comply
with NPDES requirements that would reduce
impacts to water quality.

Program OS-6.4c Permeable Surfaces.

Encourage use of pervious materials to aid in
stormwater treatment and infiltration.

Yes. The project will include the addition of
pervious surfaces, including landscaping and
bioretention/treatment areas.

Program OS-6.4e Fertilizer Use. Continue to
encourage the use of organic soil amendments
to replace chemical fertilizers as practicable on
public and private property.

Yes. The project will use organic soil amendments,
which would replace chemical fertilizers where
practicable.

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CONCLUSION
The project would not result in a new, significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to biological resources.

3.4 CULTURAL RESOURCES
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum?
a) Cause a substantial adverse change in the significance of a historical resource pursuant to Section 15064.5? LTS Yes b) Cause a substantial adverse change in the significance of an archaeological resource pursuant to Section 15064.5? LTS Yes c) Disturb any human remains, including those interred outside of dedicated cemeteries? LTS Yes
Key: LTS = less than significant

DISCUSSION
Historic Buildings and Structures
The Certified EIR includes General Plan policies that require that all future development in the Old Town Historic District is compatible with the architectural style of the district and that new developments maintain significant historic characteristics respective of their sites. The Certified EIR concluded that with the implementation of the adopted General Plan policies and programs related to the preservation of historic resources, future development under the adopted General Plan would not result in a substantial adverse change in the significance of a historical resource. The impact related to historic resources was found to be less than significant.

The project would involve the demolition of the 5,000-square-foot administration building that was a part of the former Yountville Elementary School; the building was constructed in 1951.

Ancillary structures such as the baseball dugouts, storage sheds, and shade structures (constructed in 1976) would also be removed from the site. Given the Yountville Elementary School administration building is more than 50 years old, a Historical Resources Evaluation (HRE) was completed for the property, which is included in Appendix D, Cultural Resources Report, of this Addendum. The Yountville Elementary School library building, constructed in 1976, the farmstand (former snack shack), constructed in 1976, and Schmitt Hall, constructed in 2003, would remain on-site and no alterations would be made to these structures. The HRE was based on the California Register of Historic Resources (CRHR) criteria for historic resources designation.

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CRHR Criterion 1
The school facilities would need to be associated with events that have made a significant contribution to the broad patterns of California’s history and cultural heritage to meet CRHR Criterion 1. The former Yountville Elementary School facilities were initially developed in the early 1950s to provide for the expansion of Yountville Elementary School and provide extra classroom space. The project site was the third location of the school and the previous 1920sera Yountville Elementary School campus to the south is currently used as the Town Hall. The school represents a common trend of postwar public school growth in California. Also, based on research of historical records, the school is not associated with specific events or patterns of development that have historical significance at the state level. For these reasons, the former Yountville Elementary School facilities are not eligible for the CRHR under Criterion 1.

CRHR Criterion 2
The school facilities would need to be associated with the lives of persons important in the past to meet CRHR Criterion 2. Based on archival research, the former Yountville Elementary School’s staff and students changed multiple times throughout the years and did not include an individual of notable historical significance; therefore, the former Yountville Elementary School facilities are not associated with the lives of persons significant in the past and are not eligible for the CRHR under Criterion 2.

CRHR Criterion 3
The school facilities would need to embody the distinctive characteristics of a type, period, region, or method of construction, or represent the work of an important creative individual or possess high artistic values to meet CRHR Criterion 3. The former school’s buildings exhibit minimal architectural ornamentation and do not reflect a cohesive or intentional planning concept. The administration, library, and Schmitt Hall building are modest in scale and detailing, which is consistent with public school construction during the postwar period. Therefore, the school facilities are not eligible for CRHR under Criterion 3.

CRHR Criterion 4
The school facilities would need to have yielded, or likely yield, information important in prehistory or history. The information potential of the former Yountville Elementary School facilities is shown through its built form and in the historical record. The buildings for the school have not yielded, nor are they likely to yield, information important in history or prehistory.

Therefore, the school is not eligible for the CRHR under Criterion 4.

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Integrity
The buildings at the former school retain aspects of workmanship, materials, and design because its primary buildings have experienced few alterations. However, the overall appearance of the school has evolved since the first building was constructed in the 1950s due to continued expansion and building additions throughout its development; therefore, the school has diminished integrity of setting, feeling, and association.

Based on the HRE, the existing school facilities are not eligible for CRHR under any criteria, either individually or as a part of an existing historic district. Therefore, demolition of the former administrative building would not cause a substantial adverse change in the significance of a historical resource.

The Town Hall building (6550 Yount Street) on-site was the former location of the Yountville Elementary School and was constructed in 1820. The building is included on the Napa County Historic Resources Inventories. No changes or alterations would be made to the Town Hall building. Based on the construction vibration analysis included in Section 3.11, Noise, of this Addendum, the project’s construction vibration would not result in physical damages to the Town Hall building. In compliance with adopted General Plan Policy LU-2.10, the architectural characteristics of the project’s proposed buildings would be compatible with the Town Hall building. Thus, the project would result in a less-than-significant impact on historic resources.

Additionally, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to historic resources.

Archaeological Resources
The Certified EIR concluded that with the implementation of the adopted General Plan policies and programs that require future projects to complete a records search at the Northwest Information Center (NWIC), and archaeological survey, and measures to reduce impacts to archaeological resources, future development under the adopted General Plan would not result in a substantial adverse change in the significance of an archaeological resource. The impact related to archaeological resources was found to be less than significant.

Adopted General Plan Program OH-2.1a requires projects to identify archaeological resources and Native American sacred sites and burial grounds by working with the NWIC and California Native American Heritage Commission (NAHC). Accordingly, a requested cultural resources records search for the project site at the NWIC of the California Historical Resources Information System (CHRIS) at California State University, Sonoma, in May 2025 (NWIC File No. 24-1823) was completed. The purpose of the records search was to determine the extent of previous surveys within a 0.25-mile radius of the project site and whether previously documented pre-contact or historic archaeological sites, architectural resources, or traditional cultural properties exist within this area.

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Based on the records search of previous investigations and cultural studies by other firms, no archaeological resources were recorded within the project site. A pedestrian field survey for cultural resources was completed at the site in June 2025 and a new cultural resource was found within the project site (YOU-1-I), which was a pre-contact isolated find. The isolated find consisted of two lithic flakes that were on separate patches and approximately 30 feet apart.

The ground surface in the vicinity of isolated find YOU-1-I was disturbed; it was used as a school field since at least 1958, and a baseball diamond was constructed and maintained near the isolated find between 1968 and 2020. Isolates are unassociated artifacts or minor features that represent either accidental inclusion or are otherwise disconnected from the human activity that produced it. It was determined that the find is not eligible for listing on the CRHR under any of the criteria. However, the discovery of an isolated pre-contact resource increases the potential for buried pre-contact archaeological sites closest to the creek. Therefore, consistent with adopted General Plan Programs OH-2.1b and OH-2.1d, which require appropriate measures to be implemented to reduce adverse impacts to the cultural/archaeological resources identified during the archaeological survey, the following project-specific measures requiring archaeological monitoring and contractor awareness training are required to be implemented during construction.

In compliance with Programs OH-2.1b and OH-2.1d, the following project-specific measure is required to be implemented during construction.

Project-Specific Measures Pursuant to Programs OH-2.1b and OH-2.1d (Archaeological Monitoring): The following measures shall be implemented for areas where grounddisturbing activities are within the vicinity of the existing dog park and within 100 feet of Hopper Creek to reduce impacts to archaeological resources:
 Prior to the start of construction, the Town shall retain a qualified professional archaeologist to monitor all ground-disturbing activities associated with project construction within 100 feet of Hopper Creek. The qualified monitoring archaeologist shall meet with or work under the direct supervision of someone meeting the Secretary of the Interior’s professional qualifications standards for prehistoric and historic archaeology. The qualified monitoring archaeologist and tribal monitor shall have the authority to temporarily halt ground-disturbing or construction-related work within 100 feet of any discovery of potential historical or archaeological resources in order to address unanticipated discoveries.
 Monitoring will be required for ground disturbing activities but would not be required for the placement of equipment or fill inside excavations that were monitored, aboveground construction activities, or the redistribution of soils that were previously monitored (such as the return of stockpiles to use in backfilling).

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Project-Specific Measures Pursuant to Programs OH-2.1b and OH-2.1d (Contractor Awareness Training): The following measures shall be implemented prior to construction to reduce impacts to archaeological resources:
 The Town shall ensure that a Contractor Awareness Training Program is delivered to train equipment operators about cultural resources. The program shall be designed to inform construction personnel about state regulations pertaining to cultural resources; the subsurface indicators of resources that shall require a work stoppage; procedures for notifying the lead agency of any occurrences; project-specific requirements and required measures; and enforcement of penalties and repercussions for non-compliance with the program.
 The training shall be prepared by a qualified professional archaeologist and may be provided either through a brochure, video, or in-person tailgate meeting, as determined appropriate by the qualified archaeologist. The training shall be provided to all construction supervisors, forepersons, and operators of ground-disturbing equipment.

All personnel shall be required to sign a training roster. The Construction Manager shall be responsible for ensuring that all required personnel receive the training. The Construction Manager shall provide a copy of the signed training roster to the lead agency as proof of compliance.

Project-Specific Measures Pursuant to Programs OH-2.1b and OH-2.1d (Discovery of Unrecorded Resources): The following measures shall be implemented prior to construction to reduce impacts to unrecorded cultural, archaeological, and paleontological resources:
 If subsurface deposits believed to be cultural, archaeological, or paleontological in origin are discovered during construction, all work must halt within a 100-foot radius of the discovery. A qualified professional archaeologist, meeting the Secretary of the Interior’s Professional Qualification Standards for prehistoric and historic archaeology, shall be retained to evaluate the significance of the find, and shall have the authority to modify the no-work radius as appropriate, using professional judgment. The following notifications shall apply, depending on the nature of the find:
- If the professional archaeologist determines that the find does not represent a cultural resource, work may resume immediately, and no agency notifications are required.
- If the professional archaeologist determines that the find does represent a cultural resource from any time period or cultural affiliation, the archaeologist shall immediately notify the lead agencies. The agencies shall consult on a finding of eligibility and implement appropriate treatment measures, if the find is determined to be a Historical Resource under CEQA. Work may not resume within the no-work radius until the lead agencies, through consultation as appropriate, determine that

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the site either: (1) is not a Historical Resource under CEQA; or (2) that the treatment measures have been completed to their satisfaction.

With implementation of the adopted General Plan Programs OH-2.1b and OH-2.1d, projectspecific measures including archaeological monitoring, construction awareness training, and halting work if an unrecorded resource is discovered, and applicable mitigating General Plan programs and policies, which would reduce impacts to archaeological resources encountered during construction, the project would not result in a substantial adverse change in the significance of an archaeological resource. The impact would be less than significant, and the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to archaeological resources.

Human Remains
The Certified EIR found that excavation and construction activities, regardless of depth, may yield human remains that may not be interred in marked, dedicated burials. The Certified EIR concluded that General Plan Program OH-2.1c, which would ensure that all future construction activities avoid any known burial grounds, and Program OH-2.1e, which requires that the Town be notified if an inadvertent discovery of human remains occurs during a development, the future development under the adopted General Plan would result in less-than-significant impacts with respect to the disturbance of human remains.

Similar to the conclusions in the Certified EIR, the project could result in the inadvertent discovery of human remains as there have been indications that humans have occupied Napa County for over 10,000 years.

In compliance with adopted General Plan Program OH-2.1b, the following project-specific measure is required to be implemented during construction to reduce impacts on human remains if they are discovered during construction.

Project-Specific Measures Pursuant to Program OH-2.1b and OH-2.1e (Human Remains):

The following measure shall be implemented during construction or ground-disturbing activities to reduce impacts on human remains:
 If subsurface deposits believed to be human in origin are discovered during construction, all work must halt within a 100-foot radius of the discovery. A qualified professional archaeologist, meeting the Secretary of the Interior’s Professional Qualification Standards for prehistoric and historic archaeology, shall be retained to evaluate the significance of the find, and shall have the authority to modify the no-work radius as appropriate, using professional judgment. The following notifications shall apply, depending on the nature of the find:
- If the find includes human remains, or remains that are potentially human, they shall ensure reasonable protection measures are taken to protect the discovery from

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disturbance (AB 2641). The archaeologist shall notify the Napa County Coroner (pursuant to Health and Safety Code Section 7050.5). The provisions of Section Health and Safety Code Section 7050.5, PRC Section 5097.98, and AB 2641 will be implemented. If the coroner determines the remains are Native American and not the result of a crime scene, the coroner will notify the NAHC, which then will designate a Native American Most Likely Descendant (MLD) for the Project (PRC Section 5097.98). The designated MLD will have 48 hours from the time access to the property is granted to make recommendations concerning treatment of the remains. If the landowner does not agree with the recommendations of the MLD, the NAHC can mediate (PRC Section 5097.94). If no agreement is reached, the landowner must rebury the remains where they will not be further disturbed (PRC Section 5097.98). This will also include either recording the site with the NAHC or the appropriate Information Center; using an open space or conservation zoning designation or easement; or recording a reinternment document with the county in which the property is located (AB 2641). Work may not resume within the no work radius until the lead agencies, through consultation as appropriate, determine that the treatment measures have been completed to their satisfaction.

With the implementation of the adopted General Plan Programs OH-2.1b, OH-2.1d, and OH2.1e, the project would result in a less-than-significant impact with respect to the disturbance of human remains. Therefore, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to human remains.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.5, Cultural and Tribal Cultural Resources, of the Certified EIR.

Policy or Program Consistency Finding
Policy LU-2.10 Preservation of Site
Characteristics. Require new developments to
maintain significant natural, historic, and cultural
characteristics of their respective sites.

Yes. The Town will ensure the historic
characteristics of the Town Hall building are
protected during project construction. The Town
Hall building would remain in place; no physical
changes would be made to the building. The
project would not use high vibration-generating
construction equipment (see Section 3.11, Noise,
of this Addendum) and construction vibration
would not result in physical damage to the
building. The project’s buildings would have an

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Policy or Program Consistency Finding
architectural style that is compatible with the
Town Hall building.

Policy OH-2.1 Archaeological and Cultural
Resources. Recognize the importance of
protecting significant archaeological and cultural
resources and implement measures to preserve
such resources.

Yes. The Town will implement the conditions of
approval described for Programs OH-2.1b, OH2.1d, and OH-2.1e to protect archaeological and cultural resources.

Program OH-2.1a Identification of Resources.

Work with the Northwest Information Center
and Native American Heritage Commission to
determine existence of significant archaeological
and cultural resources, including Native
American sacred sites and burial grounds.

Yes. A cultural resources records search was
completed at the NWIC for the project site and a
radius within 0.25 mile of the site in May 2025. No
archaeological resources/cultural resources were
identified based on a records search of previous
cultural resources studies. A request to complete a
Sacred Lands File (SLF) search was submitted to
the NAHC in May 2025. The results of the SLF
search are discussed in Section 3.16, Tribal Cultural
Resources.

Program OH-2.1b Protection and Preservation
of Resources. Require a cultural or
archaeological survey prior to approval of any
project where a known historical, cultural, or
archaeological resource is located or in an area
sensitive for cultural or archaeological resources.

If significant resources are identified and
recorded, require appropriate measures to
reduce adverse impacts to the resource, such as
avoidance, capping of the site, documentation
or conservation.

Yes. An archaeological survey of the project site
was completed in June 2025. Based on the survey,
one pre-contact isolated archaeological find was
discovered. Project-specific measures, pursuant to
Programs OH-2.1b and OH-2.1d (Archeological
Monitoring), which require archaeological
monitoring for construction or ground-disturbing
activities within 100 feet of Hopper Creek, will be
implemented. The Town will also implement
project-specific measures, pursuant to Programs
OH-2.1b and OH-2.1d (Contractor Awareness
Training), which require contractor awareness
training. Implementation of these conditions of
approval will reduce impacts to the isolated find to
less than significant.

Program OH-2.1d Inadvertent Discovery of
Cultural, Paleontological, and Archaeological
Resources. Require new development,
infrastructure, and other ground-disturbing
projects to stop work and notify the Town in the
event that construction or grading activities
result in an inadvertent discovery of significant
historic, cultural, paleontological or
archaeological resources. Such resources shall
be examined by a qualified historian or
archeologist for potential protection and
Yes. The Town will implement project-specific
measures, pursuant to Programs OH-2.1b and OH2.1d, Discovery of Unrecorded Resources) which require contractors to stop work and notify the
Town in the event that construction or grounddisturbing activities result in an inadvertent discovery of unrecorded resources, that could
include cultural, archaeological, or paleontological
resources. The resources will be examined by a
qualified archaeologist, and appropriate measures

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Policy or Program Consistency Finding
preservation measures, and appropriate
measures shall be implemented to preserve,
relocate, and/or record the find, as appropriate.
will be implemented to reduce impacts to these
resources to a less-than-significant level.

Program OH-2.1e Inadvertent Discovery of
Human Remains. Require new development,
infrastructure, and other ground-disturbing
projects to stop work and notify the Town in the
event that construction or grading activities
result in an inadvertent discovery of human
remains.

Yes. The Town will implement project-specific
measures pursuant to Programs OH-2.1b and OH2.1e (Human Remains) during construction or ground-disturbing activities in accordance with
this program. Contractors will be required to stop
work and notify the Napa County Coroner and the
Town in the event of an inadvertent discovery of
human remains.

Policy LU-3.1 Future Growth Conditions. Allow
future development where: it contributes to
walkability, view corridors, and an active
streetscape; the Town has capacity to provide
necessary public services; natural, historic, and
cultural assets are protected; the costs and
revenues associated with new development are
balanced; and impacts to traffic circulation are
mitigated.

Yes. The historical characteristics of the historic
Town Hall will be protected during construction.

The project’s buildings will also be compatible with
Town Hall’s architectural style. Refer to General
Policy LU-2.10.

CONCLUSION
The project would not result in a new, significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to cultural resources.

3.5 ENERGY
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum?
a) Result in potentially significant environmental impact due to wasteful, inefficient, or unnecessary consumption of energy resources, during project construction or operation?
LTS Yes
b) Conflict with or obstruct a state or local plan for renewable energy or energy efficiency? LTS Yes
Key: LTS = less than significant

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DISCUSSION
The Certified EIR did not include an evaluation of energy impacts pursuant to these new questions, because these criteria were not introduced to the CEQA Guidelines Appendix G, Environmental Checklist Form, and effective until December 28, 2018, and therefore not required by CEQA at that time. As previously described, changes in law, regulation, or guidelines adoption are not “new information” as that term is used in CEQA Guidelines Section 15162 if the information about the issue (i.e., energy conservation) was known or should have been known at the time the original EIR was certified. The Certified EIR, Chapter 3.7, Greenhouse Gases and Energy, addressed energy impacts associated with the buildout of the adopted General Plan, pursuant to Appendix F, Energy Conservation. The Certified EIR recognized that future development under the adopted General Plan would result in operational energy use such as the future developments’ electricity and natural gas usage. Further, the Certified EIR identified other major sources of energy consumption for future projects, which include fuel used by vehicle trips generated during construction and operation activities, and fuel used by off-road construction vehicles during construction.

The Certified EIR, Appendix A, Air Quality, GHG, and Energy Modeling, data (based on the size and type of land uses within the proposed General Plan) included energy usage estimates for off-road construction equipment. However, the Certified EIR recognized that the estimates were based on model defaults that typically provide an overestimate of off-road construction emissions. The modeling data also included energy output data for General Plan buildout operations. The data consisted of estimated electricity and natural gas usage for future development, including 231 residential units and approximately 81,500 square feet of retail/commercial space.

The Certified EIR concluded that future project applicant(s)/developer(s) would be responsible for conserving energy, to the extent feasible through the implementation of statewide and local measures. The Certified EIR recognized that Statewide strategies to improve energy efficiency included the California Appliance Energy Efficiency regulations, California Building Standards (e.g., CALGreen and the Building and Energy Efficiency Standards), the Renewables Portfolio Standard [RPS], and changes in the corporate average fuel economy standards (Pavley I and California Advanced Clean Cars). In addition, the Certified EIR noted that the General Plan consisted of policies and programs to reduce energy consumption and encourage the use of renewable energy, including Policy OS-8.1 and associated programs that would also reduce energy use. The Certified EIR recognized that future development under the adopted General Plan would comply with all applicable federal, state, and local regulations regulating energy use.

Therefore, the Certified EIR concluded that buildout of the adopted General Plan would not be expected to cause an inefficient, wasteful, or unnecessary use of energy resources and that the impact was less than significant.

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Project Construction and Operations Energy Impacts
The project would include the construction and operation of 150 residential units and 11,000 square feet of retail/restaurant and civic uses. Based on Table 1-1, General Plan Land Use Development Assumptions, the remaining development capacity allowed in the General Plan area for residential uses is 216 units and approximately 78,980 square feet for commercial uses.

Therefore, the project would be consistent with and within the adopted General Plan’s buildout projections and land uses.

Construction of the project would create temporary increased demands for electricity and vehicle fuels compared to existing conditions and would result in short-term transportationrelated energy use. The use of electricity would be temporary and would fluctuate according to the phase of construction. Additionally, it is anticipated that most electric-powered construction equipment would be hand tools (e.g., power drills, table saws, compressors) and lighting, which would result in minimal electricity use during construction activities. It is not anticipated that construction equipment used for the project would be powered by natural gas, and no natural gas demand is anticipated during construction. Furthermore, future development facilitated by the project would not introduce new types of construction processes or activities compared to what was previously considered in the Certified EIR because the project site does not contain peculiar conditions that would require highly unique or atypical construction equipment use. In addition, use of all construction equipment would cease upon completion of project construction. Therefore, energy impacts with respect to project construction would be less than significant.

Transportation energy use depends on the type and number of trips, vehicle miles traveled (VMT), fuel efficiency of vehicles, and travel mode. Transportation energy use during construction would come from the transport and use of construction equipment, delivery vehicles and haul trucks, and construction employee vehicles that would use diesel fuel and/or gasoline. The use of energy resources by these vehicles would fluctuate according to the phase of construction. It is anticipated that the majority of off-road construction equipment, such as those used during demolition and grading, would be gas or diesel powered. To limit wasteful and unnecessary energy consumption, the construction contractors are anticipated to minimize nonessential idling of construction equipment during construction, in accordance with CCR Section 2449, Title 13, Article 4.8, Chapter 9. Construction vehicle trips would also not result in unnecessary use of energy since the project site is centrally located and is served by numerous regional freeway systems (State Route 29) that provide direct routes from various areas of the region. Thus, impacts related to transportation energy use during construction would not require expanded energy supplies or the construction of new infrastructure.

The Certified EIR accounted for the energy consumption of off-road construction equipment used for future development under the adopted General Plan. Given the project would be consistent with the construction of development types assumed in the Certified EIR and that

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the project’s construction equipment would be more energy and fuel efficient than the equipment assumed in the Certified EIR, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to wasteful, inefficient, or unnecessary consumption of energy resources during project construction.

Project operation would involve the use of electricity and transportation energy use.

Operational use of electricity would include heating, cooling, and ventilation of buildings; water heating; operation of electrical systems; use of on-site equipment and appliances; and lighting.

Electrical service to the project site would be provided by PG&E through connections to existing off-site and on-site electrical lines and new on-site infrastructure. The project would incorporate an all-electric design, with no use of natural gas for building systems or appliances. The project would include solar PV panels and battery storage at the proposed multifamily buildings. The project would comply with the California Energy Commission (CEC’s) 2022 Building Energy Efficiency Standards that require low-rise multifamily developments to include solar photovoltaic (PV) systems to offset the electrical consumption of the proposed buildings and support the RPS goals in advancing renewable energy. In addition, the project would be consistent with the current CEC’s Building Energy Efficiency Standards, including the Title 24 Energy Code and CALGreen requirements, which would be more stringent than the standards assumed in the Certified EIR. Therefore, the proposed development would be more energy efficient than what was modeled for the development in the Certified EIR and operation of the project would result in less-than-significant impacts with respect to operational energy use.

The project would consume fuel and other forms of transportation energy during operations from the use of motor vehicles. Appendix A, Air Quality, Greenhouse Gas, and Energy Modeling, of the Certified EIR assumed approximately 1,917 daily vehicle trips would be generated from the 231 residential units and 3,332 daily trips would be generated by the 81,500 square feet of commercial/retail space. Based on the project’s Transportation Impact Study (refer to Appendix G, Transportation Impact Study, of this Addendum), the project would result in 594 daily trips for the 150 multifamily residential units and 485 daily trips for the civic and retail/restaurant uses. The estimated trips for the residential component are conservative estimates since parking at the multifamily residential buildings would not be allowed.

The project is intended to provide affordable housing targeted toward the local workforce, which would help reduce automobile reliance and the amount of VMT generated by the residents. Since the project would generate less trips than assumed in the Certified EIR, and trip lengths associated with the retail/restaurant and civic uses are not anticipated to exceed those analyzed in the Certified EIR, the project would not exceed fuel consumption estimated for the residential and commercial land uses evaluated in the Certified EIR. Additionally, due to ongoing improvements in State and federal vehicle fuel efficiency standards, the average fuel efficiency for vehicles used by employees of the project is expected to improve over time as older, less fuel-efficient vehicles are retired and replaced with newer models or alternative fuel vehicles

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(e.g., electricity, hydrogen). Therefore, energy impacts with respect to project operations would be less than significant and the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to the wasteful, inefficient, or unnecessary consumption of energy resources, during project operations.

State/Local Plan for Renewable Energy or Energy Efficiency As described previously, the project would include solar PVs, which would be consistent with RPS goals to advance renewable energy and the 2022 Building Efficiency Standards. The project would include EV infrastructure and an all-electric building design, which directly supports the goals of the California Public Utilities Commission (CPUC) Energy Action Plan by promoting clean energy use and improving energy efficiency. Consistent with the Certified EIR conclusions, the project would not conflict with or obstruct a state or local plan for renewable energy or energy efficiency, and this impact would be less than significant. The project would not result in a new, significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to renewable energy or energy efficiency.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policy and program identified in Chapter 3.7, Greenhouse Gases and Energy, of the Certified EIR.

Policy or Program Consistency Finding
Policy OS-8.1 Conserve Energy and Use
Renewable Energy. Increase energy efficiency
and conservation and encourage the use of
renewable energy.

Yes. The project would be consistent with Policy
OS-8.1. See Program OS-8.1a.

Program OS-8.1a Design of Buildings. Encourage
the design of new buildings and remodel of
existing buildings with consideration of reducing
the environmental impacts and costs of heating,
cooling, and lighting through the use of efficient
mechanical equipment, solar orientation, natural
light and airflow, and shade trees.

Yes. The project would comply with the CEC’s 2022
Building Efficiency Standards, RPS goals and Energy
Action Plan. The project would include solar PV
panels and battery storage, which would provide
renewable energy and efficient cooling, heating,
lighting, and mechanical equipment. In addition,
the project would include the planting of trees
which would provide shading.

CONCLUSION
The project would not result in a new, significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to energy.

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3.6 GEOLOGY AND SOILS
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum?
a) Directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury, or death involving:
i) Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning
Map, issued by the State Geologist for the area or based on other substantial evidence of a known fault? (Refer to Division of Mines and Geology Special Publication 42.)
LTS Yes
ii) Strong seismic ground shaking? LTS Yes
iii) Seismic-related ground failure, including liquefaction? LTS Yes iv) Landslides? LTS Yes
b) Result in substantial soil erosion or the loss of topsoil? LTS Yes 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?
LTS Yes
d) Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial direct or indirect risks to life or property?
LTS Yes
e) Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater?
LTS Yes
f) Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature? LTS Yes
Key: LTS = less than significant

DISCUSSION
The Certified EIR concluded that development under the adopted General Plan would not directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury, or death, related to faulting, seismic shaking, or landslides. The Certified EIR also concluded that with the implementation of General Plan policies and associated programs, there would be lessthan-significant impacts with respect to the loss of topsoil, unstable soil or expansive soil, soils incapable of adequately supporting the use of septic tanks or alternative wastewater systems, and unique paleontological resources.

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The Certified EIR found there were no Alquist-Priolo earthquake fault zones in the town but that the Green Valley Fault was approximately 10 miles to the southeast and 11.5 south of the town.

The Certified EIR acknowledged that fault rupture could cause seismic ground shaking.

Therefore, the Certified EIR concluded that future development in the General Plan area could expose people or structures to potential adverse effects associated with a seismic event, including strong ground shaking and seismic-related ground failure.

The Certified EIR noted that future projects within the General Plan area would be required to comply with the provisions of the California Building Standards Code (CBSC), which requires development to complete geotechnical investigations in accordance with State law. The Certified EIR concluded that with implementation of adopted General Plan Policy SH-1.1 and associated programs that outline requirements to reduce the risk of loss of life, as well as applicable CBSC and YMC standards, impacts associated with a seismic event, including rupture of an earthquake fault, seismic ground shaking, liquefaction, and landslides would be less than significant.

Seismic Hazards
In compliance with adopted General Plan Program SH-1.1a, which mandates projects to address potential seismic and geologic hazards and conform to seismic requirements, and the CBSC, which requires projects to prepare site-specific geotechnical studies, a geotechnical study report was prepared for the project in September 2025 (refer to Appendix E, Geotechnical Investigation Report, of this Addendum). Pursuant to the geotechnical study report and the California Geological Survey’s Earthquake Zones of Required Investigation Map, there are no active faults on the project site, and the site is not within an Alquist-Priolo fault zone. Thus, there is a low risk of fault rupture to occur on the project site. However, like much of California, the site is within an area affected by strong seismic activity; thus, the project could be subject to hazards from seismic shaking. Thus, it will be necessary to design and construct the project in strict adherence with current standards for earthquake-resistant construction. In compliance with adopted General Plan Program SH-1.1a, which requires projects to address potential seismic and geologic hazards and conform to seismic requirements, the Town would implement the project-specific measures presented in the geotechnical study report to reduce impacts related to seismic hazards to a less-than-significant level.

In compliance with adopted General Plan Program SH-1.1a, the following project-specific measure is required to be implemented.

Project-Specific Measures Pursuant to Program SH-1.1a (Seismic Hazards): In accordance the CBSC’s requirements, the Town shall implement the following measures to reduce impacts from seismic hazards:

Prior to and during construction, the Town shall implement the recommendations described in the design-level Geotechnical Study Report dated September 16, 2025,

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prepared by RGH Consultants by incorporating the recommendations from the Geotechnical Study Report into the final construction-level project designs.

The recommendations in the geotechnical study report address soil hazards such as unstable, liquefiable, and expansive soils and include geotechnical strategies that shall be implemented to mitigate the potential for structural damage. The study also addresses potential seismic and ground failure issues and includes recommendations related to earthquake-resistant construction techniques. With the implementation of the project-specific measure, the project would not cause potential substantial adverse effects, including the risk of loss, injury, or death due to seismic-related events and landslides. This impact would be less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR with respect to fault rupture, seismic shaking, liquefaction, or landslides.

Erosion
The Certified EIR recognized that construction-related erosion could result in the loss of a substantial amount of nonrenewable topsoil and could adversely affect water quality in nearby surface waters. The Certified EIR concluded that with the implementation of the adopted General Plan policy and programs related to erosion and sediment control and drainage and erosion requirements (shown in the table below), development under the adopted General Plan would result in a less-than-significant impact related to erosion and the loss of topsoil.

The project’s ground-disturbing activities could temporarily increase soil erosion rates during project construction. In compliance with adopted General Plan Program OS-6.4b, the project would implement RWQCB SWPPP erosion-control measures such as installation of mulching and silt fences. With the implementation RWQCB SWPPP erosion-control measures, the project would not result in substantial erosion or the loss of topsoil. Thus, the impacts related to erosion and topsoil would be less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to erosion and loss of topsoil.

Unstable and Expansive Soils
The Certified EIR could result in the exposure of people and structures to conditions that have the potential for adverse effects associated with ground instability or failure. The Certified EIR found that soils and geologic conditions in the General Plan area may have the potential for landslides, lateral spreading, subsidence, liquefaction, or collapse. In addition, the Certified EIR concluded that with the implementation of General Plan programs and policies and CBSC, including preparation of geotechnical soils investigations to address soil instability and safety issues, development under the adopted General Plan would have a less-than-significant impact related to unstable geologic units/soils and expansive soils.

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The project is not in a California Geological Survey liquefaction hazard zone. Accordingly, the site is relatively flat and is not in a landslide hazard zone. A Geotechnical Study Report has been prepared for the project and the recommendations are required to be adhered to as identified in the project-specific measure pursuant to Program SH-1.1a (Seismic Hazards). With the implementation of project-specific measure pursuant to Program SH-1.1a, the project would result in a less-than-significant impact related to unstable geologic units/soils and expansive soils.

Septic Tanks/Alternative Wastewater Disposal Systems
The Certified EIR concluded that the adopted General Plan would not result in the use of septic tanks or alternative wastewater disposal systems. Therefore, the impact related to soils that are incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems was determined to be less than significant. Accordingly, the project would connect to the Town’s existing sewer facilities and would not require the use of septic tanks or alternative wastewater disposal systems. Thus, project would have no impact related to the use of alternative wastewater systems.

Paleontological Resources
The Certified EIR found that no paleontological resources were identified within the General Plan area, based on an online search of the University of California Museum of Paleontology.

The Certified EIR concluded that future projects would be subject to the requirements of General Plan Program OH-2.1d, which requires that future development stop work if a resource is encountered and notify the Town of the find, impacts to paleontological resources would be less than significant. As discussed in Section 3.4, Cultural Resources, the implementation of the project-specific measures pursuant to Program OH-2.1b and OH-2.1d (Discovery of Unrecorded Resources), including halting work if an unrecorded resource is discovered, would reduce impacts to potential paleontological resources encountered during construction, the project would not result in a substantial adverse change in the significance of a paleontological resource.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.6, Geology and Soils, of the Certified EIR.

Policy or Program Consistency Finding
Policy SH-1.1 Seismic and Geologic Hazards.

Reduce the risk of loss of life, personal injury and
property damage resulting from seismic and
geologic hazards including ground shaking, land
sliding, liquefaction and slope failure.

Yes. A site-specific geotechnical study report has
been prepared for the project (see Appendix E)
which identifies the geologic and soil conditions,
such as liquefaction and associated lateral
spreading and settlement, at the site and includes

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Policy or Program Consistency Finding
recommendations to address seismic and soil
stability concerns. The Town would implement
project-specific measures pursuant to Program SH1.1a, to require compliance with the recommendations for the project design (such as
recommendations pertaining to seismic design,
building foundation support, and grading), which
would reduce seismic and geologic hazards to a
less-than-significant level.

Program SH-1.1a Seismic and Geologic Safety.

Require new subdivision and development
proposals and infrastructure projects and
additions and remodels, as applicable, to
address potential seismic and geologic hazards
and to conform to seismic requirements of the
California Building Code and, when applicable,
the California Environmental Quality Act.

Yes. Refer to Policy SH-1.1.

Policy OS-6.4 Water Quality. Protect water
resources from pollution and sedimentation.

Yes. The project will implement NPDES SWPPP
measures to reduce impacts on water quality.

Measures to reduce impacts related to
sedimentation could include the installation of
mulching and silt fences during construction. See
Section 3.9, Hydrology and Water Quality, of this
Addendum.

Program OS-6.4b NPDES Compliance. Ensure
that new development, redevelopment, and
infrastructure projects comply with the
requirements of the National Pollutant
Discharge Elimination System (NPDES) permit
and the applicable Stormwater Discharge System
Ordinance and do not substantially degrade
water quality.

Yes. Refer to Policy OS-6.4.

Program OH-2.1d Inadvertent Discovery of
Cultural, Paleontological, and Archaeological
Resources. Require new development,
infrastructure, and other ground-disturbing
projects to stop work and notify the Town in the
event that construction or grading activities
result in an inadvertent discovery of significant
historic, cultural, paleontological or
archaeological resources. Such resources shall
be examined by a qualified historian or
archeologist for potential protection and
Yes. The Town will implement project-specific
measures pursuant to Program OH-2.1b and OH2.1d (Discovery of Unrecorded Resources), which requires contractors to stop work and notify the
Town in the event that construction or grounddisturbing activities result in an inadvertent discovery of unrecorded paleontological resources.

The resources will be examined by a qualified
archaeologist, and appropriate measures will be
implemented to reduce impacts to these resources
to a less-than-significant level.

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Policy or Program Consistency Finding
preservation measures, and appropriate
measures shall be implemented to preserve,
relocate, and/or record the find, as appropriate.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to geology and soils.

3.7 GREENHOUSE GAS EMISSIONS
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum?
a) Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment? LTS Yes b) Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of greenhouse gases? LTS Yes Key: LTS = less than significant

DISCUSSION
The Certified EIR acknowledged that the State’s implementation of California Air Resources Board (CARB) 2017 Climate Change Scoping Plan, which ensured consistency with the statewide greenhouse gas (GHG) reduction targets provided by Assembly Bill (AB) 32, Senate Bill (SB) 32, and Executive Order (EO) S-3-05, which called for a statewide GHG reduction in emissions to 1990 levels by 2020, 40 percent below 1990 levels by 2030, and 80 percent below 1990 levels by 2050, respectively. The Certified EIR also notes that the Bay Area Air District (formerly the Bay Area Air Quality Management District, referred to here as the Air District) established a plan-level GHG emissions threshold for operational emissions of 6.6 metric tons of carbon dioxide equivalent (MTCO2e)/service population/year in effort to assist the State in meeting its GHG emission reduction goals. Based on the estimated 4,278 MT CO2e that the adopted General Plan buildout would generate and an estimated service population of 764 (439 residents and 325 employees), the Certified EIR determined that General Plan buildout would generate approximately 5.6 MT CO2e/service population/year, which was below the Air District’s plan-level threshold for operational emissions of 6.6 MT CO2e/service population/year. The Certified EIR concluded that since development under the adopted General Plan would be consistent with statewide regulations, the Air District’s GHG thresholds, and applicable General Plan policies, General Plan buildout would not generate GHG emissions that would have a

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significant impact on the environment or conflict with an applicable plan, policy, or regulation adopted for the purposes of reducing GHG emissions. The impacts associated with GHG emissions and consistency with applicable GHG policies or regulations were considered less than significant.

Long-term operation of the project would result in water demand, wastewater, and solid waste generation, area sources (e.g., consumer cleaning products), energy usage (i.e., electricity), refrigerant use, and vehicle trips. The CARB 2022 Scoping Plan for Carbon Neutrality identified strategies and actions to achieve statewide carbon neutrality by 2045, while also meeting the interim 2030 GHG reduction goal established by SB 32. As described in Section 3.5, Energy, of this Addendum, the project development is consistent with Certified EIR’s development assumptions pertaining to development type, size, and number of units and, therefore, would not result in an increase GHG emissions above what was assumed in the Certified EIR. The Air District released 2022 CEQA Guidelines that identify the necessary design elements required of new land use projects and plans being built to achieve California’s long-term climate goal of carbon neutrality by 2045. Based on the Air District’s Climate Impact Thresholds of Significance for land use projects, a project that complies with a local GHG reduction strategy that is consistent with State guidance (State CEQA Guidelines Section 15183.5[b]) or incorporates the Air District’s project design element requirements, would be determined to make a less-thansignificant contribution to GHG emissions. The Town’s Climate Action Plan (CAP), published in 2016, was developed as an advisory document only and is not considered a qualified GHG reduction plan per CEQA Guidelines Section 15183.5(b]). Therefore, the project would be required to include the Air District’s minimum project design elements, listed below.

Air District Climate Impact Thresholds of Significance
Projects must include, at a minimum, the following project design elements:
 Buildings
 The project will not include natural gas appliances or natural gas plumbing (in both residential and nonresidential development).
 The project will not result in any wasteful, inefficient, or unnecessary energy use as determined by the analysis required under CEQA Statute Section 21100(b)(3) and CEQA Guidelines Section 15126.2(b).
 Transportation
 The project will achieve a reduction in project-generated vehicle miles traveled (VMT) below the regional average consistent with the current version of the California Climate Change Scoping Plan (currently 15 percent) or meet a locally adopted Senate Bill 743 VMT target that reflects the recommendations provided in the California Governor’s Office of Land Use and Climate Innovation (LCI) Technical Advisory: Evaluating Transportation Impacts in CEQA:

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- Residential projects: 15 percent below the existing VMT per capita - Office projects: 15 percent below the existing VMT per employee - Retail projects: no net increase in existing VMT
 The project will achieve compliance with off-street electric vehicle requirements in the most recently adopted version of CALGreen Tier 2.

The project would be all-electric and would not include the use of natural gas infrastructure. As described in Section 3.6, Energy, the project would be constructed in compliance with the most current Building Energy Efficiency Standards, including Title 24 Energy Code and CALGreen requirements, and would not result in any wasteful, inefficient, or unnecessary energy use.

Based on Section 3.17, Transportation, the proposed 11,000 square feet of retail and civic uses would be local serving and below 50,000 square feet. Therefore, the proposed retail and civic uses would have a less-than-significant impact on VMT, i.e., at least 15 percent below the VMT per capita in the town. Given the project’s residential density, based on California Air Pollution Officers Association’s (CAPCOA’s) guidance, the project would have a VMT per capita of 11.98, which would meet the 15 percent below the VMT per capita in the town. Furthermore, the project’s proximity to central Yountville and the ability for residents to easily walk and bicycle to nearby destinations provide further support for the premise that the project would have a lessthan-significant VMT impact (Appendix G, Traffic Impact Study, of this Addendum). Lastly, as described in Section 2.3.5, Utilities, under the subheading “Other Utilities,” the project electric vehicle charging spaces in conformance with the CALGreen voluntary Tier 2 EV-Ready Multifamily (Level 2) standards, as well as off-street electric vehicle requirements in the most recently adopted version of CALGreen Tier 2.

Given that the project would be consistent with the current Air District’s project design elements, the project would not generate GHG emissions, either directly or indirectly, that would have a significant impact on the environment. The impact is considered less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to GHG emissions impacts.

Additionally, given the project would incorporate the project design elements required under the Air District’s climate impact thresholds, the project would be consistent with the CARB 2022 Scoping Plan in implementing measures to helping the state reach carbon neutrality by 2045. As part of the implementation framework for Plan Bay Area 2050, local governments have identified Priority Development Areas (PDAs) to focus growth.

The project would replace the former school administration building with a mixed-use development in an already developed part of town, which would be consistent with the overall goals of Plan Bay Area 2050 in concentrating future development in locations where there is existing infrastructure. Specifically, the project would include future multifamily housing,

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commercial space, and civic facilities to serve both the future residents and existing local population. Placing residential and nonresidential uses together and promoting mixed-use development shortens travel distances between homes, workplaces, and amenities. This would also contribute to minimizing VMT and mobile emissions. Overall, the project would not conflict with the land use concept plan in Plan Bay Area 2050. Furthermore, the project would comply with the Town’s CAP measures to reduce GHG emissions (see table below). Consistent with the Certified EIR conclusions, the project would have a less-than-significant impact with respect to consistency with an applicable plan, policy or regulation adopted for the purpose of reducing GHG emissions. Therefore, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to consistency with applicable plan, policy, or regulations for reducing GHG emissions.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.7, Greenhouse Gas Emissions and Energy, of the Certified EIR, and the recommended measures in the Town of Yountville CAP.

Policy, Program, or CAP Measures Consistency Finding
Policy OS-8.1 Conserve Energy and Use
Renewable Energy. Increase energy efficiency
and conservation and encourage the use of
renewable energy.

Yes. Refer to Section 3.6, Energy, of this
Addendum. The project would in solar PV panels
and battery storage which would provide
renewable energy. The project will be consistent
with CARB’s 2022 Building Efficiency Standards.

Program OS-8.1a Design of Buildings. Encourage
the design of new buildings and remodel of
existing buildings with consideration of reducing
the environmental impacts and costs of heating,
cooling, and lighting through the use of efficient
mechanical equipment, solar orientation, natural
light and airflow, and shade trees.

Yes. Refer to Section 3.6, Energy, of this
Addendum. The project would be all-electric and
would not include natural gas use (which would
reduce GHG emissions). The project would also
include EV charging and EV ready stations which
would encourage the use of electric vehicles, and
reduce GHG emissions.

Program OS-8.4b Climate Action Plan.

Implement the Town’s Climate Action Plan and
periodically update the plan to incorporate
updated emission levels and new emission
reduction targets.

Yes. Refer to the Town’s CAP Measures below.

CAP 2-1: Pedestrian Travel. Encourage walking as
an alternative to vehicular travel
Yes. See CAP 2-1a and 2-1d.

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Policy, Program, or CAP Measures Consistency Finding
CAP 2-1a: Establish and maintain a system of
pedestrian facilities and crossing enhancements
that are consistent with the Town’s Bicycle
Master Plan.

Yes. The project would replace the existing
sidewalks along Yount Street and Finnell Road and
replace them with new sidewalks along the project
frontage. The project would include the addition
of new raised crosswalks at Webber Street and
Yount Street and Humboldt Street and Yount
Street. The existing crosswalk mid-block on Finnell
Road would be repaired and would connect to the
proposed farmstand.

CAP 2-1d: Enhance the safety of any pedestrian
crossings in the Town. (General Plan C 2.9)
Yes. See CAP 2-1a.

CAP 2-6: Electric Vehicles. Increase ownership of
electric vehicles.

Yes. See 2-6b below.

CAP 2-6b: Consider requiring new and
redeveloped commercial and multifamily
projects to provide electric vehicle charging
stations.

Yes. The proposed parking lot for the retail and
civic uses would include EV charging and EV-ready
stations.

CAP 3-2: Outdoor Water Use. Reduce outdoor
water use.

Yes. See CAP 3-2a below.

CAP 3-2a: Continue to implement the State’s
model Water Efficiency Landscape Ordinance
that requires water efficient landscaping through
the design, installation, and maintenance of new
and rehabilitated landscape projects.

Yes. The project would include water-efficient
landscaping, which would reduce water
consumption and reduce reliance on fossil-fuel
powered equipment for landscape maintenance,
thereby reducing fossil fuel emissions.

CAP 3-6: Water-Efficient Landscaping. Continue
to replace spray irrigation with drip irrigation
systems and utilize weather-based irrigation
controllers wherever feasible. Continue to
replace plants with drought-tolerant species
when renovating landscaping.

Yes. The project would include drip irrigation
systems and utilize weather-based irrigation
controllers, where feasible. The project would
include drought-tolerant landscaping which will
require approval by the Town’s landscaping
consultant.

CAP 4-1: Community Waste. Reduce waste sent
to the landfill by composting organic materials,
increasing recycling, reusing materials, and
reducing consumption.

Yes. The project would include recycling and
composting bins. This would encourage residents
and employees of the project to recycle and
compost, which would reduce the amount of
waste being delivered to landfills.

CAP 5-1: Tree Planting on Private Land. Increase
Yountville’s tree cover.

Yes. See CAP 5-1a through 5-1c below.

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Policy, Program, or CAP Measures Consistency Finding
CAP 5-1a: Require new development and
significant remodeling projects to plant trees
along street frontages or in front yard areas,
wherever feasible.

Yes. The project would plant trees throughout the
site, including the site’s parking areas. Trees would
also be planted around the multifamily buildings
and within open space areas. The project would
include street trees along Finnell Road and Yount
Street frontages.

CAP 5-1b: Require new and renovated parking
lots to plant trees, wherever feasible.

Yes. CAP 5-1a.

CAP 5-1c: Require replacement of trees that are
removed.

Yes. The project would plant new trees proposed
for removal in accordance with YMC Section

17.128.060.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to greenhouse gas emissions.

3.8 HAZARDS AND HAZARDOUS MATERIALS
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions for
an Addendum
a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials?
LTS Yes
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?
LTS Yes
c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school?
LTS Yes
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?
LTS Yes
e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard or excessive noise for people residing or working in the project area?
NI Yes

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Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions for
an Addendum
f) Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan? LTS Yes g) Expose people or structures, either directly or indirectly, to a significant risk of loss, injury or death involving wildland fires? LTS Yes Key: NI = no impact; LTS = less than significant

DISCUSSION
Routine Transport, Use, or Disposal of Hazardous Materials The Certified EIR acknowledged that future development allowed under the adopted General Plan may involve the transportation, use, and/or disposal of hazardous materials. The Certified EIR recognized that the use, transportation, and disposal of hazardous materials is regulated and monitored by local fire departments (including the Napa County/California Department of Forestry and Fire Protection [CAL Fire]), Certified Unified Program Agencies (CUPAs), the State Division of Occupational Safety and Health, and the Department of Toxic Substances Control.

The Certified EIR concluded that with the implementation of the above General Plan programs and compliance with federal, State, and local regulations, the project would not create a significant hazard to the public or the environment with respect to the routine transport, use, or disposal of hazardous materials. The impact was determined to the less than significant.

The project would be used for residential, retail/restaurant, and civic uses. Operation of the project could include the use and storage of small quantities of chemicals for janitorial cleaning and landscape maintenance. The use of these materials would be in regulated quantities and in accordance with the manufacturers’ instructions for use, storage, and disposal of these products. The Town will comply with applicable federal, state, and local handling, storage, and disposal requirements, which would result in a less-than-significant impact on public or the environment with respect to the routine transport, use, or disposal of these substances. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to the transport, use, or disposal of these substances.

Reasonably Foreseeable Accident Conditions Involving the Release of Hazardous Materials
The Certified EIR recognized that future project activities may involve equipment or construction activities that use hazardous materials (e.g., coatings, solvents and fuels, and diesel-fueled equipment), the transportation of excavated soil contaminants, or disposal of contaminated materials at an approved disposal site. The Certified EIR recognized that future

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development allowed under the adopted General Plan would be subject to all applicable General Plan policies and programs as well as federal and State regulations pertaining to hazardous materials. Additionally, the Certified EIR concluded that future developments’ compliance with adopted General Plan policies and programs as well as applicable federal, state, and local regulations pertaining to hazardous materials would ensure the impact on the public and environment, with respect to reasonably foreseeable accident conditions involving the release of hazardous materials, would be less than significant.

The project site was used for agricultural purposes and included a rural residence until approximately 1950. Construction of the Yountville Elementary School administration building was completed in 1951 and subsequent structures/buildings associated with the school were constructed until 2003. Operations of the school ended in 2020, and the site is currently used for recreational, Town employee meeting hall, farmstand, and civic (i.e., Town Hall) purposes.

Since the project site was formerly used for agricultural purposes, the Phase I Environmental Site Assessment (Phase I ESA) recommendations included the completion of a screening level assessment of shallow soil for the potential presence of organochlorine pesticides (OCPs) and associated metals (see Appendix F, Environmental Site Assessments, of this Addendum). Based on the conclusions of the Phase I ESA, the potential presence of elevated OCPs and associated metals in soil was a potential environmental concern. In accordance with the Phase I ESA recommendations, on March 13, 2024, soil samples were collected at about 0.5 feet below ground surface at the project site. Most of the samples were analyzed for OCPs and arsenic. A sample near the former residence was analyzed for OCPs, arsenic, and lead. The arsenic and lead were detected below background concentrations for alluvial soils. OCPs and diesel range organics were not detected above the laboratory reporting limits. Therefore, residual OCPs and associated metals from pesticides are not a significant environmental concern at the site.

Given the age of the former school buildings on-site (including the administration building proposed for demolition), the buildings may consist of asbestos-containing materials (ACMs) and lead-based paint (LBP). The demolition of the administration building could result in the release of ACMs and LBP into the environment and result in the exposure of construction workers to these materials. General Plan Program SH-1.8a requires project-specific measures to protect the public health from the hazards associated with the transportation, storage, and disposal of hazardous wastes and materials. Therefore, the following project-specific measures shall be implemented to reduce the impacts related to the release of ACM, LBP, and termiticides.

In compliance with Program SH-1.8a, the following project-specific measures are required to be implemented prior to and during construction.

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Project-Specific Measures Pursuant to Program SH-1.8a (Reducing ACMs, LBP, and Termiticide Exposure):
 In accordance with state and local laws, a visual inspection/pre-demolition survey, shall be completed prior to the demolition of on-site building(s) to determine the presence of ACMs, LBP, and termiticides.
 Removal of older structures with LBP is subject to requirements outlined by the California Division of Occupational Safety and Health (Cal/OSHA) Lead in Construction Standard, CCR Title 8, Section 1532.1 during demolition activities.  Potentially friable ACMs are required to be removed prior to building demolition in accordance with The National Emission Standards for Hazardous Air Pollutants (NESHAP) guidelines. Removal of materials containing more than one-percent asbestos are required to be completed in accordance with Bay Area Air District requirements and notifications.
 Termiticides are required to be removed in accordance with the U.S. Environmental Protection Agency regulations.

The adopted General Plan Program SH-1.7b requires a soils analysis for all new residential developments and other sensitive receptors when there is a history of agricultural or industrial use. As stated previously, some soils have already been tested in March 2024 and found low levels of OCPs and associated metals and are not considered an environmental concern.

However, some additional soil testing is still required pursuant to General Plan Program SH-1.7b.

Soils around the administrative building, which is proposed to be demolished, are currently covered by paved concrete and hardscape, which was not accessible at the time of the March 2024 soil testing.

In compliance with adopted General Plan Program SH-1.7b, the following project-specific measure is required to be implemented at the demolition phase.

Project-Specific Measures Pursuant to Program SH-1.7b (Reducing OCP and Lead Exposure): Shallow soil samples shall be conducted within two feet of the administrative building foundation after demolition, and prior to construction of the proposed development. The samples shall be analyzed for OCPs and lead to confirm the concentrations of OCPs and lead around the building. The Town’s contractors will comply with state regulatory requirements for the proper handling and disposal of soils from the site.

With the implementation of the project-specific measures that are in compliance with regulatory requirements and adopted General Plan Programs SH-1.7b and SH-1.8a described in this section, the project would not create a significant hazard to the public or the environment through reasonably foreseeable accident conditions involving the release of hazardous materials into the environment. The project would not result in a new significant impact or a

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substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to the release of hazardous materials.

Hazardous Materials Impacts on Schools
The Certified EIR acknowledged that all hazardous materials would be handled in accordance with federal, State, and local requirements, which would limit the potential for a project to expose nearby uses, including schools, to hazardous emissions or an accidental release. The Certified EIR concluded that with future projects’ compliance with these General Plan policies and programs that require compliance with regulations that reduce hazards associated with the transportation, storage, and disposal of hazardous wastes and materials, development allowed under the adopted General Plan would not emit hazardous emissions or handle hazardous or hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school. The impact was determined to be less than significant.

There are no schools located within one-quarter mile of the project site and the project would have no impact related to hazardous materials impacts on schools. Therefore, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to hazardous materials impacts on schools.

Hazardous Materials Sites Compiled Pursuant to Government Code Section 65962.5
The Certified EIR concluded that the General Plan area did not contain any hazardous materials sites compiled pursuant to Government Code Section 65962.5. Therefore, the impact related to a hazardous materials site that could create a significant hazard to the public or environment, was determined to be less than significant.

The project site is not listed on a hazardous materials site compiled pursuant to Government Code Section 65962.5 and, therefore, the project would not be located on a hazardous materials site that would create a significant hazard to the public or the environment. 9The impact would be less than significant. Therefore, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to a hazardous materials site creating an impact on the public or environment.
9 California Environmental Protection Agency. 2025, November 13 (accessed). “Cortese List Data Resources.” CalEPA.ca.gov. https://calepa.ca.gov/sitecleanup/corteselist/. November 13, 2025.

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Airport Hazards
The Certified EIR acknowledged that the nearest airport to the General Plan area was Parrett Field, which is approximately 12 miles north of the General Plan area. The Certified EIR recognized that the General Plan area is not in any protection or safety zones identified in an airport land use plan and is not within two miles of a public airport or private airstrip. Therefore, the Certified EIR concluded there was no impact with respect to airport safety hazards and noise.

Like all of Yountville, the site is not in any protection or safety zones identified in an airport land use plan and is not within two miles of a public airport or private airstrip and the project would result in no impact related to airport hazards. Therefore, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to airport hazards.

Consistency with an Adopted Emergency Response Plan
The Certified EIR acknowledged that future development under the adopted General Plan would be subject to the Napa County Operational Area Hazard Mitigation Plan (HMP) which addresses disasters that could affect Napa County and provides plans for reducing or mitigating these threats. The Certified EIR concluded that compliance with adopted General Plan programs and policies pertaining to the HMP would ensure that future development under the adopted General Plan would not impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan. The impact was considered less than significant.

The project would include driveways on Finnell Road and Yount Street which would allow vehicles to enter and exit the site in the event of an emergency. With the addition of project traffic, delays would be up to 8.8 seconds per vehicle during AM and PM peak hours at nearby intersections (which include Yount Street and Madison Street, Yount Street and Finnell Road, and Yount Street and Washington Street). Therefore, significant delays that would affect emergency vehicle response times are not anticipated at the site’s nearby intersections. The project would not impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan. The impact would less than significant. Therefore, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to interference with an emergency response/evacuation plan.

Wildfire
Chapter 3.8, Hazards and Hazardous Materials, of the Certified EIR addressed the impacts to wildfire hazards associated with buildout of the adopted General Plan. Impacts were found to be less than significant with full buildout of the adopted General Plan with implementation of

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General Plan policies and programs, that would ensure potential wildland fire hazards are mitigated through requirements for adequate water supply and water flow availability, ensuring adequate emergency access and adequate fire protection services. As discussed in the other sections of this Addendum, the project would not result in a new significant impact or substantial increase in the severity of impacts identified in the Certified EIR for water supply and flow availability (Section 3.17, Utilities and Service Systems), emergency access (Section 3.15, Transportation), and adequate fire protection services (Section 3.13, Public Services). Therefore, the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to related to wildfire.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.8, Hazards and Hazardous Materials, of the Certified EIR.

Policy or Program Consistency Finding
Program SH-1.3f Fire Risk in New Development.

1. Review all development proposals for fire
risk and require mitigation measures to
reduce the probability of fire. Encourage
attractive native and drought-tolerant, lowmaintenance landscaping responsive to fire hazards. Require all new development to
meet the adopted State and local fire codes.

2. Require adequate access for emergency
vehicles, adequate street width and vertical
clearance, driveway access and parking
restrictions for new development.

3. Require sprinkler systems for new
commercial and residential development
and substantial remodels and additions.

Yes. The project would include driveway access on
Finnell Road and Yount Street. The driveways
would be at least 24 feet wide, in accordance with
the Town’s design standards. Emergency vehicles
would have adequate access to the site. In
addition, the project would include native and
drought-tolerant landscaping and sprinkler
systems.

Policy SH-1.7 Soil Quality. Protect and preserve
soil as a natural resource.

Yes. See Programs 1.7a and 1.7b below.

Program SH-1.7a Toxic Chemicals. Ensure the
proper use, storage, and disposal of toxic
chemicals to prevent soil contamination.

Yes. The project could include the use and storage
of cleaning and landscaping maintenance
chemicals in small quantities. The project would
comply with applicable federal, State, and local
regulations pertaining to the use, storage, and
transport of toxic chemicals, as described in this
section.

Program SH-1.7b Soils Analysis. Require soils
analysis for all new residential developments
Yes. Phase II ESA sampling was completed at the
site for OCPs and associated metals (given the

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Policy or Program Consistency Finding
and other sensitive receptors when there is a
history of agricultural or industrial use.
site’s former agricultural use) in March 2024. The
sample results showed the concentrations of OCPs
and associated metals at the site were below
laboratory reporting limits and background
concentrations, which is not considered significant
environmental concern. In an area that is currently
covered by hardscape, shallow sampling will be
completed after demolition of the administration
building, and prior to construction of the proposed
development. The samples will be analyzed for
OCPs and lead.

Policy SH-1.8 Hazardous Materials. Minimize
risks and health impacts from environmental
and human-induced disasters.

Yes. Based on the Phase II ESA sample results,
there is no known contamination at the site that
would be hazardous to the public or environment.

The project would comply with applicable
regulations for the handling, transport, and
disposal of soil during project construction.

Program SH-1.8a Measures to Reduce Hazards.

Require measures to protect the public health
from the hazards associated with the
transportation, storage, and disposal of
hazardous wastes and materials.

Yes. Regulatory measures pertaining to the survey
and disposal of ACMs, LBP, and termiticides will be
implemented prior to, during, and after
demolition, in accordance with regulatory
requirements. Measures requiring compliance
with regulatory standards pertaining to soil
sampling and analysis for OCPs and lead, as well
the transport and soil will be implemented after
demolition. The purpose of these measures is to
protect the environment and the public from being
exposed to contaminants.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to hazards and hazardous materials.

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3.9 HYDROLOGY AND WATER QUALITY
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions for
an Addendum
a) Violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or groundwater quality?
LTS Yes
b) Substantially decrease groundwater supplies or interfere substantially with groundwater recharge such that the project may impede sustainable groundwater management of the basin? LTS Yes
c) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river or through the addition of impervious surfaces, in a manner which would:
i) result in substantial erosion or siltation on- or off-site; LTS Yes ii) substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off-site; LTS Yes iii) create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff; or LTS Yes
iv) impede or redirect flood flows? LTS Yes
d) In flood hazard, tsunami, or seiche zones, risk release of pollutants due to project inundation?
2018 CEQA
Guidelines Yes
e) Conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan? 2018 CEQA
Guidelines Yes
Key: LTS = less than significant

DISCUSSION
The Certified EIR did not include checklist questions pertaining to conflicts with a water quality control plan and sustainable groundwater management plan and the risk release of pollutants in a flood hazard, tsunami or seiche zone because these checklist questions were not introduced to the CEQA Guidelines Appendix G, Environmental Checklist Form, until December 28, 2018, and therefore the topics were not required to be addressed under CEQA at that time.

As previously described, changes in law, regulation, or guidelines adoption are not “new

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information” as that term is used in CEQA Guidelines Section 15162 if the information about the issue was known or should have been known at the time the original EIR was certified.

Water Quality Standards
The Certified EIR acknowledged that future development applicants would be required to submit a Stormwater Pollution Prevention Plan (SWPPP) with a Notice of Intent to the RWQCB to obtain a General Permit. In addition, the Certified EIR acknowledged that the SWPPP should specify best management practices that would be implemented to reduce the amount of pollutants and sediment in stormwater during construction. Additionally, the Certified EIR identified that the amount of runoff generated by future projects would be greater than under 2015 conditions, due to increases in impervious surfaces. The Certified EIR concluded that with the implementation of adopted General Plan policies and programs, and compliance with applicable RWQCB regulations that would reduce water pollution from future development, implementation of the adopted General Plan would result in less-than-significant impacts pertaining to the violation of water quality standards, waste discharge requirements, or degradation of surface or groundwater quality.

The project would comply with the RWQCB Construction General Permit regulations. The Town would submit a SWPPP to RWQCB that includes best management practice to control the discharge of sediment and pollutants associated with construction activities. The best management practices that would be implemented during construction include but are not limited to the measures herein:

Measures to Reduce Polluted Runoff and Erosion at Construction Sites Prior to and during construction, the Town (or the Town’s contractor) would comply with the RWQCB Construction General Permit (Order No. 2022-0057-DWQ, as amended) and best management practices, which could include, but are not limited to, those listed herein:

Erosion and Sediment Controls
 Install fiber rolls (wattles) along downslope perimeters of disturbed areas  Install silt fence barriers at storm drain inlets and property boundaries  Place gravel bag berms at curb inlets
 Stabilize construction entrance/exit (with a minimum 50-foot rock pad)  Conduct hydroseeding or place erosive control blankets on slopes steeper than 3:1  Water exposed soil surfaces daily (a minimum of two times per day or as needed for dust control)
 Cover soil stockpiles with anchored tarps during non-work periods  Immediately revegetate completed slopes within 14 days

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Stormwater Run-On and Run-Off Controls
 Install drainage swales to divert off-site runoff around construction areas  Install temporary detention basins (if needed based on SWPPP calculations)  If dewatering operations are required, ensure filtration and sediment settling is conducted before water is discharged, win compliance with the NPDES permit Materials and Waste Management
 Designate concrete washout areas at least 50 feet away from storm drains/creek  Store and cover any on-site chemicals, fertilizers, and liquid materials  Use secondary containment for the storage of fuel
 Remove litter/debris from the site daily
 Conduct street sweeping on Yount Street and Finnell Road weekly during the earthwork phases of construction
Good Housekeeping
 Maintain sanitary facilities based on the California Department of Industrial Relations, Division of Occupational Safety and Health requirements  Conduct vehicle/equipment maintenance off-site; if vehicle maintenance must be done onsite, perform work over a drip pans large enough to collect fluids  Keep spill prevention kits at strategic locations including in areas where fuel and materials are stored
 Post 24-hour emergency contact information at the site entrance Monitoring and Reporting
 Ensure that a Qualified SWPPP Practitioner (QSP) conducts weekly inspections during the rainy season
 QSP shall complete storm event inspections within 48 hours of 0.5-inch precipitation  Implement a rain event action plan (REAP) when NOAA forecast predicts a 50 percent or greater chance of 0.5 inches or more of rain within a 24-hour period  Report results of inspections monthly to the RWQCB via the SMARTS database Bioretention Area Protection During Construction
 Protect areas designated for permanent bioretention facilities from construction traffic and compaction.

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 Conduct final planting and mulch installation after upstream construction activities are complete to prevent sediment accumulation in bioswales
The project would add pervious surfaces to the site, which would result in an approximately 30 percent decrease in impervious surfaces. The project would replace approximately 5,500 square feet of impervious surfaces at the proposed pool area. Based on the RWQCB Municipal Regional Stormwater NPDES Permit for the San Francisco Bay Region, projects that will add and/or replace more than 5,000 square feet of impervious surfaces are required to design and construct stormwater treatment controls to treat post-construction stormwater runoff.

Stormwater treatment controls proposed by the project include bioretention/treatment areas and the addition of pervious pavement. With the implementation of SWPPP construction best management practices, NPDES stormwater treatment controls, and General Plan programs, the project would not violate any water quality standards or substantially degrade surface or groundwater quality. The proposed project’s impact would be less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to water quality.

Groundwater Recharge
The Certified EIR found that future development allowed under the adopted General Plan would result in new impervious surfaces and could reduce stormwater infiltration and groundwater recharge. The Certified EIR concluded that with the implementation of General Plan policies and programs which encourage the implementation of best management practices that reduce the amount of pervious surfaces converted to impervious surfaces, development allowed under the adopted General Plan would not interfere substantially with groundwater recharge. The impact was considered less than significant.

The proposed project would add pervious surfaces to the site which would result in a decrease in impervious surfaces, compared to existing conditions. The proposed project would increase groundwater recharge potential at the site. The project site is in the Napa-Sonoma Valley Basin.

The proposed project would not require substantial groundwater pumping. If shallow groundwater is encountered during project construction, temporary dewatering may be required. Temporary dewatering would be conducted in compliance with regulations under the NPDES permit and would not result in the depletion of groundwater supplies. Therefore, the proposed project would not substantially decrease groundwater supplies or interfere with groundwater recharge. The impact would be less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to groundwater supply and recharge.

Stormwater Drainage
The Certified EIR acknowledged that development allowed under the adopted General Plan could potentially alter surface drainage patterns as a result of directly altering flow patterns,

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which could yield increased amounts of stormwater runoff. The Certified EIR concluded that with the implementation of General Plan policies and programs that would reduce the potential for future development to result in increased flooding, runoff, siltation, or erosion, development allowed under the adopted General Plan would have a less than significant impact related to the alteration of the existing drainage pattern on the site or area.

The project would include the addition of pervious surfaces which would decrease the amount of impervious surfaces at the site by approximately 30 percent. The addition of pervious surfaces would result in a decrease in runoff from the site, compared to existing conditions. The project would comply with Municipal Regional Permit Provision C.3 Low Impact Development (LID) requirements. Stormwater runoff from the project site would be held and treated in the bioretention areas before being discharged through the existing 18-inch storm drain outfall into Hopper Creek, located to the east side of the project site. The Town would implement SWPPP best management practices during construction to reduce the potential for erosion. The project site is not in a FEMA-designated special flood hazard area; thus, stormwater runoff from the site is not expected to redirect flood flows. Therefore, the impact related to the alteration of the existing drainage pattern on the site or area would be less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to drainage alteration.

Risk Release of Pollutants Due to Inundation
The Certified EIR recognized that the General Plan area is not located in a tsunami hazard area or a seiche zone. The Certified EIR also acknowledged approximately 80 percent of the General Plan area is outside of the 100-year flood zone (i.e., special flood hazard area). The Certified EIR concluded that risks related to tsunamis, seiches and flood hazards (with the implementation of General Plan programs and policies) would be less than significant. Because the project site is not located in a tsunami hazard area,10 a seiche zone, or a flood hazard area, the project would have no impact related to the risk release of pollutants due to project inundation.

Water Quality Control Plan and Sustainable Groundwater Management Plan In addition, the project would not interfere with groundwater recharge or deplete groundwater supplies in the Napa-Sonoma Valley Groundwater Basin and, therefore, would not conflict with a groundwater management plan. The project would comply with the NPDES requirements regarding stormwater treatment and reducing runoff as well as RWQCB requirements related to SWPPP best management practices g construction water quality. Therefore, the project would 10 California Geological Survey. “Tsunami Hazard Area Map.” Accessed November 13, 2025. https://maps.conservation.ca.gov/cgs/informationwarehouse/ts_evacuation/.

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not obstruct the implementation of a water quality control plan or a sustainable groundwater management plan. Therefore, the impact would be less than significant.

The project would comply with the mitigating General Plan policies and programs identified shown in the below table and identified in Chapter 3.9, Hydrology and Water Quality, of the Certified EIR.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROPOSED PROJECT As shown in the table, the proposed project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.9, Hydrology and Water Quality, of the Certified EIR.

Policy or Program Consistency Finding
Program SH-1.2g Storm Drainage System.

Maintain unobstructed water flow in the storm
drainage system to the maximum extent
feasible. Continue to carry out inspections and
maintenance of drainage systems.

Yes. The project will utilize a distributed LID
approach with pervious surfaces and bioretention
facilities, minimizing traditional storm drain
infrastructure. The project would include pervious
pavements on all proposed parking areas,
driveways, and pedestrian walkways. The
bioretention areas would include landscaped areas
throughout the site.

Stormwater would be collected via roof drains
which would be directed to landscape bioretention
areas. Stormwater would also be directed to
pervious paving. Any overflow that would occur in
bioretention areas during storm events would be
directed a subsurface conveyance.

The Town's Stormwater Control Plan will be
submitted to the RWQCB prior to construction as
required by the Municipal Regional Stormwater
NPDES Permit. Final civil engineering plans will
include detailed drainage calculations, bioretention
sizing worksheets, and long-term maintenance
provisions. Compliance with the NPDES and LID
requirements for storm drainage and treatment, the
project would not obstruct the Town’s storm
drainage system. Routine inspections and
maintenance of drainage systems will be conducted
throughout the life of the project. Stormwater
runoff from the site would be held and treated in
the bioretention areas before being discharged

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Policy or Program Consistency Finding
through the existing outfall into Hopper Creek to the
east of the site.

Program SH-1.2l Napa County Stormwater
Pollution Prevention Program. Work with the
Napa County Flood Control District to implement
the Stormwater Pollution Prevention Program to
minimize negative impacts of storm runoff.

Yes. The Town will coordinate outfall the Napa
County Flood Control District to implement
Stormwater Pollution Prevention Program best
management practices discussed in this section to
reduce impacts related to stormwater runoff.

Policy SH-1.6 Erosion and Runoff Control.

Implement measures to reduce soil erosion and
surface runoff during and after construction.

Yes. The Town will prepare SWPPP best
management practices that would be implemented
to reduce the amount of polluted stormwater runoff
generated from the construction site and soil
erosion. The best management practices are
discussed in this Addendum section.

Program SH-1.6a Soil Stabilization Measures.

Encourage soil stabilization measures that
prevent soil erosion.

Yes. The project will implement SWPPP
construction best management practices to prevent
soil erosion at construction sites, as discussed in the Addendum section.

Policy OS-6.4 Water Quality. Protect water
resources from pollution and sedimentation.

Yes. SWPPP best management practices that would
be implemented to reduce the amount of polluted
stormwater runoff generated from the construction
site, soil erosion, and sedimentation, as noted in
Policy SH-1.6. In addition, the project would comply
with NPDES requirements regarding stormwater
treatment controls, including the addition of
pervious pavement and bioretention areas on-site.

Program OS-6.4a Best Management Practices.

Require new development, redevelopment, and
infrastructure projects to implement best
management practices as feasible, including lowimpact development techniques, the minimal use of non-pervious surfaces in landscape
design, and the integration of natural features
into the project design, to naturally filter and
biodegrade contaminants and to minimize
surface runoff into drainage systems and creeks.

Yes. The project would include low impact
development techniques including the addition of
pervious surfaces that include landscaping,
bioretention areas, and pervious pavement. The
bioretention areas would treat the stormwater
runoff before it directed to the Hopper Creek
outfall, which would minimize the amount of
contaminants that would enter the creek.

Program OS-6.4b NPDES Compliance. Ensure
that new development, redevelopment, and
infrastructure projects comply with the
requirements of the National Pollutant
Discharge Elimination System (NPDES) permit
and the applicable Stormwater Discharge System
Ordinance and do not substantially degrade
water quality.

Yes. The proposed project would comply with the
NPDES permit requirements. The project would
include stormwater treatment controls such as
bioretention areas and pervious pavement, which
would reduce the amount of runoff, including
polluted runoff, that would enter Hopper Creek.

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Policy or Program Consistency Finding
Program OS-6.4c Permeable Surfaces.

Encourage use of pervious materials to aid in
stormwater treatment and infiltration.

Yes. The proposed project would utilize pervious
pavement within the design on the project’s ground
level surfaces (i.e., parking areas, walkways and
landscaping areas). The project would also include
biotreatment areas that will treat stormwater runoff
generated from the site.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to hydrology and water quality.

3.10 LAND USE AND PLANNING
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
a) Physically divide an established community? LTS Yes
b) Cause a significant environmental impact due to a conflict with any land use plan, policy, or regulation adopted for the purpose of avoiding or mitigating an environmental effect?
LTS Yes
Key: LTS = less than significant

DISCUSSION
The Certified EIR recognized that the adopted General Plan does not include any new areas designated for urbanization or new roadways, infrastructure, or other features that would divide existing communities and impacts would be less than significant.

The project would not involve the construction of roadways or other infrastructure that would divide the community. The project would be a net benefit to the Town’s overall connectivity. The project would involve the replacement of sidewalks along project frontages on Yount Street and Finnell Road. The project would include a pedestrian path on the northern end of the site, which would connect to Hopper Creek trail. The project would improve the connectivity of the pedestrian facilities in the area and would not physically divide the community. The project’s impact would be less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to physically dividing an established community.

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The Certified EIR acknowledged that development allowed under the adopted General Plan would be required to be consistent with all applicable policies, standards, and regulations, including those land use plans, policies, and regulations adopted to mitigate environmental effects by the Town. The Certified EIR concluded that any potential environmental impact associated with conflicts with land use plans, policies, and requirements would be less than significant.

The project would require approval of a General Plan Amendment and rezoning of the site from Public Facilities and Parks and Playfields to a Yountville Commons zoning district and General Plan land use designation to allow for the proposed mixed-use development. The Creekside Overlay zone at the eastern edge of the site would remain. The existing site is within zoning districts that reflect the site’s General Plan land use designations. Although the project would require rezoning and a General Plan Amendment, the project’s land uses are consistent with the land uses evaluated in the Certified EIR and identified in the adopted General Plan, including residential, retail, and other commercial uses. The proposed General Plan Amendment would include an increase in allowed height in the area from two stories to three stories. The proposed three-story multifamily development would be set back from the surrounding streets and properties. The proposed development would be compatible with the adjacent land uses.

The project would result in potential environmental impacts, including those related to aesthetics and noise, as described in the Certified EIR. These conflicts are addressed in Sections

3.1, Aesthetics and Section 3.11, Noise. The project would result in a less-than-significant impact. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to land use conflicts.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT Applicable mitigating land use policies and programs are listed in the remaining environmental topic areas included in the Certified EIR and this Addendum.

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CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to land use and planning.

3.11 NOISE
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
a) Result in the generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies?
SU Yes
b) Result in the generation of excessive groundborne vibration or groundborne noise levels? LTS Yes
c) Be 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 and if so expose people residing or working in the project area to excessive noise levels?
NI Yes
Key: NI = no impact; LTS = less than significant

DISCUSSION
Temporary or Permanent Increase in Ambient Noise Levels The Certified EIR indicated that General Plan Policy NS-1.2 and associated programs, along with future conditions of approval, could reduce excessive exterior and interior traffic noise levels that exceed 60 A-weight decibels (dBA) community noise equivalent level (CNEL) at sensitive receptors. Furthermore, the traffic noise impacts were determined to be less than significant.

The Certified EIR found that with the implementation of the adopted General Plan policies and programs, as well as compliance with the YMC Chapter 8.04, Noise Control Regulations, impacts of short-term construction noise exceeding noise standards would remain significant and unavoidable. General Plan Program NS-1.2f requires future projects to address constructionrelated noise impacts and employ standard best practice controls to alleviate construction noise. However, the Certified EIR determined that it was unlikely that this program could guarantee compliance with the Town’s Noise Ordinance standards.

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Construction Noise Impacts
Noise generated by on-site construction equipment is based on the type of equipment used, its location relative to sensitive receptors, and the timing and duration of noise-generating activities. Each phase of construction involves different types of equipment and has distinct noise characteristics. Noise levels from construction activities are typically dominated by the loudest three pieces of equipment. The dominant equipment noise source is typically the engine, although work-piece noise (such as dropping of materials) can also be noticeable.

The construction equipment mix was estimated and categorized by construction activity using the Federal Highway Administration Roadway Construction Noise Model (RCNM). Average noise levels from project-related construction activities are calculated by modeling the three loudest pieces of equipment per activity phase. Equipment for grading and site preparation is modeled at spatially averaged distances (i.e., from the acoustical center of the general construction site to the property line of the nearest receptors) because the area around the center of construction activities best represents the potential average construction-related noise levels at the various sensitive receptors for mobile equipment. Building construction and architectural coating are measured from the edge of the proposed buildings to the nearest sensitive receptors. Additionally, paving is measured from the edge of the nearest paving areas to the nearest sensitive receptors. Construction noise modeling does not account for existing masonry walls at adjacent residential property lines, which could provide up to 6 dBA reduction based on existing wall heights. Results are summarized in Table 3-6, Project Related Construction Noise Levels, at the nearest receptors. Exterior construction noise levels at a reference distance of 50 feet would range between 74 dBA and 85 dBA Leq throughout the construction period.

Table 3-6 Project-Related Construction Noise Levels
Construction
Activity Phase
Noise Levels in dBA Leq
RCNM
Reference
Noise
Level
Multi-Family
Receptor to
North
MultiFamily/Hotel
Receptor to
South
Townhouse
Receptor to
East
Single-Family
Receptor to
West
Ext Int Ext Int Ext Int Ext Int
Distance in feet 185 a 210 a 225 a 225 a 260 a 265 a 135 a 150 a Demolition 85 74 53 72 52 71 51 76 55
Site Preparation 83 72 51 70 50 69 49 74 53
Grading 84 73 52 71 51 70 50 75 54
Distance in feet 75 a 100 a 105 a 105 a 110 a 125 a 105 a 120 a Building Construction 78 74 52 72 52 71 50 72 50
Architectural Coating 74 70 48 68 48 67 46 68 46
Distance in feet 90 a 115 a 100 a 100 a 110 a 125 a 100 a 115 a Paving 79 74 52 73 53 72 51 73 52
Distance in feet 100 a 125 a 95 a 95 a 135 a 150 a 95 a 110 a

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Table 3-6 Project-Related Construction Noise Levels
Finish/Landscaping 80 74 52 74 54 71 50 74 53
Source: FHWA’s RCNM software.

Notes.
a. Distances measured using Google Earth (2025).
dBA Leq = Energy-Average (Leq) Sound Levels; Ext = Exterior; Int = Interior See Appendix G, Noise Data, of this Addendum for modeling inputs and results.

The nearest sensitive receptors under the project include single-family homes and multifamily/hotel receptors as close as 95 feet to the west and south, respectively, of the various construction stages, as shown in Table 3-6. The construction equipment mix is similar to what was described in the Certified EIR and includes concrete saws, dozers, excavators, tractors, loaders, backhoes, excavators, graders, forklifts, generators, welders, and air compressors, pavers and paving equipment, and rollers. These items were modeled using RCNM. Project exterior construction noise levels would range between 67 dBA to 76 dBA Leq at the nearest sensitive receptors throughout the construction phases. Assuming a 20 dBA reduction due to residential building facades with windows open condition, project construction noise would be reduced to a range of 47 dBA to 56 dBA Leq at the interior spaces of the nearest noise sensitive residential uses.

The project would not result in a substantial increase in construction noise, compared to what was analyzed in the Certified EIR, since the project would involve similar types of construction equipment and construction techniques. However, the project could cause significant noise impacts to the neighboring receptors during construction. General Plan Program NS-1.2f requires future development to implement construction best management practices to reduce construction noise at nearby residences and sensitive receptors. Therefore, the Town will implement project-specific measures pursuant to Program NS-1.2d to reduce impacts related to construction noise to a less-than-significant level.

In compliance with Program NH-1.2d, the following project-specific measures are required to be implemented during construction.

Project-Specific Measures Pursuant to Program NS-1.2d (Construction Noise):

Implementation of the following measures by the Town or the Town’s contractor will reduce the construction noise to limits.
 Construct temporary noise barriers, where feasible, to screen stationary noisegenerating equipment. Temporary noise barrier fences would provide a 5 dBA noise reduction if the noise barrier interrupts the line-of-sight between the noise source and receptor and if the barrier is constructed in a manner that eliminates any cracks or gaps.

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 At a minimum, the construction contractor shall implement the following control measures: improved mufflers, equipment redesign, use of intake silencers, ducts, engine enclosures, and acoustically-attenuating shields or shrouds.  Equipment used for project construction shall be hydraulically or electrically powered impact tools (e.g., jack hammers) wherever possible to avoid noise associated with compressed air exhaust from pneumatically-powered tools. Where use of pneumatically powered tools is unavoidable, an exhaust muffler on the compressed air exhaust shall be used. A muffler could lower noise levels from the exhaust by up to about 10 dBA.
 External jackets on the tools themselves shall be used where feasible; this could achieve a reduction of 5 dBA. Quieter procedures shall be used (such as drilling rather than impact equipment) wherever feasible.
 The construction contractor shall not allow any construction equipment, trucks, or vehicles to idle.
 Locate stationary noise-generating equipment, such as air compressors or portable power generators, as far as possible from sensitive receptors as feasible. If they must be located near receptors, adequate muffling (with enclosures where feasible and appropriate) shall be used to reduce noise levels at the adjacent sensitive receptors.

Any enclosure openings or venting shall face away from sensitive receptors.  Construction staging areas shall be established at locations that will create the greatest distance between the construction-related noise sources and noisesensitive receptors nearest the project site during all project construction.  Locate material stockpiles, as well as maintenance/equipment staging and parking areas, as far as feasible from residential receptors.
 Control noise from construction workers’ radios to a point where they are not audible at existing residences bordering the project site.  Designate a "disturbance coordinator" who would be responsible for responding to any complaints about construction noise. The disturbance coordinator will determine the cause of the noise complaint (e.g., bad muffler, etc.) and will require that reasonable measures be implemented to correct the problem. Conspicuously post a telephone number for the disturbance coordinator at the construction site and include in it the notice sent to neighbors regarding the construction schedule.

Operational Off-Site Traffic Noise Impacts
Based on the conclusions in the Certified EIR, a project would have a have a significant effect on the environment related to traffic noise if it substantially increases the ambient noise levels for adjoining areas. Most people can detect changes in sound levels of approximately 3 dBA under normal, quiet conditions, and changes of 1 to 3 dBA under quiet, controlled conditions. Changes of less than 1 dBA are usually indiscernible. A change of 5 dBA is readily discernible to most

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people in an outdoor environment. Noise levels above 60 dBA CNEL are normally unacceptable at sensitive receptor locations such as residences, schools, and noise environments in these areas would be considered degraded. Based on this, a significant impact would occur if the following traffic noise increased by 5 dBA or more relative to the existing noise environment or exceed 60 dBA CNEL.

Table 3.11-12 of the Certified EIR shows that traffic noise increases of approximately 0.9 dBA along Finnel Road and 1.2 dBA along Yount Street would occur with adopted General Plan buildout (without the project). Traffic volume data for the net new trips associated with the project provided in Appendix H, Transportation Impact Study, of this Addendum. The traffic data presents the street and locations with scenarios for existing, existing with project conditions, future, and future with project conditions. With project trip additions, noise levels along the segments of Yount Street would increase by less than 2 dBA over existing ambient noise levels; all other roadway segments would increase by less than 1 dBA. Table 3-7, Project-Related Increases in Traffic Noise, dBA CNEL at 50 Feet, shows the project trip addition of project trips would not result in a 5 dBA increase over existing conditions. Therefore, traffic noise impacts would be less than significant.

Table 3-7 Project-Related Increases in Traffic Noise, dBA CNEL at 50 Feet Roadway
Segment Traffic Noise Increase Existing CNEL at 50 Feet From To
Existing
No
Project
Existing
with
Project
Existing
Increase
Baseline
(2028)
No
Project
Baseline
with
Project
(2028)
Future
(2028)
Increase
Madison
Street
Yount
Street
the
West 55 56 <1 56 56 <1
Yount
Street
Madison
Street
the
North 52 53 <2 53 54 <1
Yount
Street
Madison
Street
Finnel
Road 55 55 <1 56 56 <1
Yount
Street
Finnel
Road
Washington
Street
54 55 <2 55 56 <2
Finnel
Road
Yount
Street
the
East 49 49 <1 49 49 <1
Washington
Street
Yount
Street
the
North 57 57 <1 58 58 <1
Washington
Street
Yount
Street
the
South 57 57 <1 58 58 <1
Source: W-Trans (2025).

See Appendix G, Noise Data, of this Addendum, for calculations.

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Existing land uses adjacent near the project site would not be exposed to significant project traffic noise increases or exceed 60 dBA CNEL. Thus, the project would not result in a substantial permanent increase in traffic noise above the Town’s standards. Thus, the impact related to traffic noise would be less than significant and the project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to traffic noise impact.

Stationary Noise
The project would include rooftop heating, ventilation, and cooling (HVAC) equipment for the proposed on-site buildings. Rooftop HVAC units would generate noise levels of up to 74 dBA at 3 feet and due to distance attenuation alone would be reduced to 50 dBA at 45 feet (York 2006).

The nearest residential receptors would be approximately 55 feet to the north of the nearest project building with rooftop HVAC. Not accounting for rooftop parapets, HVAC noise levels at the residential receptors to the north would be approximately 49 dBA. The project’s HVAC noise would comply with the YMC Section 8.04.026 (Noise Ordinance) and would not exceed daytime or nighttime base ambient noise level standards of 55 dBA and 50 dBA Leq, respectively.

Therefore, no significant stationary noise changes to existing uses would occur and the noise generated by the project’s HVAC equipment would not exceed the Town’s noise standards at adjacent properties. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to new stationary noise impact.

Groundborne Vibration Impacts
The Certified EIR concluded that vibration impacts from future development under the adopted General Plan were determined to be less than significant with the implementation of the adopted General Plan Policy NS-1.3 and associated programs.

Potential vibration impacts associated with future development are usually related to the use of heavy construction equipment during the demolition or grading phases of construction.

Construction equipment generates vibration that spreads through the ground and diminishes with distance from the source. The effects from vibration can range from no perceptible effects at the lowest vibration levels, to low rumbling sounds and perceptible vibrations at moderate levels, to slight structural damage at the highest levels. Vibration from construction activities rarely reaches the levels that can damage structures.

For reference, a peak particle velocity of 0.20 in/sec Peak Particle Velocity (PPV) is used as the limit for nonengineered timber and masonry buildings (which would apply to the off-site surrounding residential structures). The Certified EIR applied a 0.30 in/sec PPV cosmetic damage at buildings of normal conventional construction threshold and a 0.08 in/sec PPV historical structure threshold. Table 3-8, Vibration Impact Levels for Typical Construction Equipment, shows typical construction equipment vibration levels and reference vibration levels at a

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distance of 25 feet. The nearest construction activity would occur closest to the multi-family and hotel uses to the south of the Project site. The closest multi-family and hotel buildings to the project site are 95 feet south.

Table 3-8 Vibration Impact Levels for Typical Construction Equipment Equipment
Inches per Second Peak Particle Velocity (PPV)
Reference
Levels
MultiFamily
Receptor to
North
MultiFamily/Hotel
Receptor to
South
Townhouse
Receptor to
East
Single-Family
Receptor to
West
at 25 Feet at 100 feet at 95 feet at 125 feet at 110 feet Vibratory Roller 0.21 0.026 0.028 0.019 0.023
Large Bulldozer 0.089 0.011 0.012 0.008 0.010
Caisson Drilling 0.089 0.011 0.012 0.008 0.010
Loaded Trucks 0.076 0.010 0.010 0.007 0.008
Jackhammer 0.035 0.004 0.005 0.003 0.004
Small Bulldozer 0.003 0.000 0.000 0.000 0.000
Source: FTA 2018.

See Appendix G, Noise Data, of this Addendum for modeling inputs and results.

As shown in Table 3-8, typical construction equipment, aside from vibratory rollers, produce vibration levels of less than 0.2 in/sec PPV at 25 feet. Assuming construction would occur along the project site boundary, the nearest structures to the proposed construction activities would be approximately 95 feet south of the project site. Vibration levels attributable to a vibratory roller would attenuate to approximately 0.026 in/sec PPV at 100 feet. Program NS-1.3a requires future development to minimize vibration impacts to adjacent uses during demolition and construction. For sensitive historic structures, a vibration limit of 0.08 in/sec PPV will be used to minimize the potential for cosmetic damage to the building. A vibration limit of 0.30 in/sec PPV will be used to minimize the potential for cosmetic damage at buildings of normal conventional construction, pursuant to the Certified EIR, is applied for assessing vibration impacts from Project construction-related activities. Construction vibration levels would not exceed the Certified EIR 0.3 in/sec PPV threshold at adjacent off-site structures to the project. Furthermore, heavy duty construction roller equipment would maintain a distance of at least 48 feet from the on-site historical building (i.e., the Town Hall building) and a distance of at least 27 feet for large bulldozers to ensure compliance with the historical vibration limit of 0.08 in/sec PPV for on-site structures. Therefore, vibration impacts from construction would be less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to vibration.

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Airport Noise
The Certified EIR determined that with the implementation of the adopted General Plan Policy NS-1.2, and associated programs, as well as compliance with the YMC Section 8.04.026, temporary or periodic increases in ambient noise levels from stationary sources would be less than significant. The Certified EIR determined that future development under the adopted General Plan would not expose people residing or working in the project area to excessive aircraft noise levels. The General Plan area is not located within two miles of a public airport or private airstrip and would result in no impact.

The nearest airports to the project site are the Napa County Airport and Sonoma Valley Airport, approximately 13 miles south and southeast, respectively. Given the distance the project site to the nearest airport and the project would be outside of an airport influence area, the proposed would not expose people residing or working in the area to excessive aircraft/airport noise levels. Therefore, no impact related to aircraft or airport noise would occur. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to aircraft/airport noise.

Traffic Noise Compatibility (Non-CEQA Effects)
Based on the 2015 California Building Industry Association (CBIA) versus the Air District California Supreme Court decision, CEQA generally requires analysis of a project's impact on the environment, not the environment's impact on the project. However, the adopted General Plan Program NS-1.2c requires an acoustical study for all new residential and noise-sensitive projects with a future exterior noise exposure of 60 dBA average day-night noise level (Ldn)or greater.

Therefore, a traffic noise compatibility analysis was completed for the proposed residential uses.

The Town’s exterior traffic noise compatibility standard for residential uses is 60 dBA Ldn (which is considered as normally acceptable). The project would primarily be affected by traffic on Yount Street and Finnel Road, which borders the project site to the west and south, respectively.

Based on the traffic noise levels shown in Table 3.11-12 of the Certified EIR, the project’s land uses would be compatible with Yount Street and Finnel Road traffic noise levels per Policy NS1.2. The future 60 dBA Ldn traffic noise contour would only extend 18 feet from Finnel Road centerline and 25 feet from Yount Street centerline. At these distances, traffic noise levels would be below 60 dBA Ldn at the nearest proposed multi-family residences. The exterior noise levels at the proposed multi-family residential buildings would not exceed the normally acceptable land use compatibility standard of 60 dBA Ldn. Furthermore, assuming an exterior to interior noise reduction of 25 dBA attributable to common building practices, interior traffic noise levels would be below 45 dBA Ldn. Therefore, the project’s residential uses would be consistent with adopted General Plan Table NS-3 Land Use Compatibility Standards.

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MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.11, Noise, of the Certified EIR.

Policy or Program Compliance
Policy NS-1.1 Noise in the Community. Protect
the livability and quality of life in Yountville by
reducing unwanted noise as feasible.

Yes. Based on the noise analysis completed for the
project, the project would not exceed the Town’s
thresholds for operational noise, including traffic
noise and stationary mechanical equipment noise
levels at adjacent properties.

Policy NS-1.2 Noise Impacts of Development.

Prevent land uses and new development that
increase noise levels above acceptable standards
as feasible.

Yes. The project would not exceed the Town’s
thresholds for operational noise, including traffic
noise and stationary mechanical equipment noise
levels at adjacent properties. Operational noise
levels will acceptable and would not exceed the
Town’s thresholds.

Program NS-1.2a Land Use Compatibility
Standards. Apply the Land Use Compatibility
Standards in Table NS-3 in locating and designing
new development.

Yes. Although not required under CEQA as this is
an impact of the environment on the project, a
traffic noise compatibility analysis was completed
for the proposed residential uses as described in
the discussion above. The exterior noise levels at
the proposed multi-family residential buildings
would not exceed the normally acceptable land
use compatibility standard of 60 dBA Ldn.

In addition, the noise analysis completed for the
project found with the addition of project traffic,
traffic noise levels would be less than 60 dBA Ldn at
adjacent land uses, which is consistent with the
allowed noise levels at land uses shown in the
adopted General Plan Table NS-3 Land Use
Compatibility Standard.

Program NS-1.2c Acoustical Compatibility
Study. Require an acoustical study for all new
residential and noise-sensitive projects with a
future exterior noise exposure of 60 dBA Ldn or
greater as shown on Table NS-3 [reproduced as
Figure 3.11-2] and incorporate mitigation
measures to lower interior noise exposure to a
maximum indoor noise level of 45 dBA Ldn.

Yes. Although not required under CEQA since
traffic the compatibility study addresses the
effects of the environment on the project, the
traffic noise compatibility analysis was completed
for the proposed multi-family residential uses as
described in the analysis above. The exterior noise
levels at the proposed multi-family residential
buildings would not exceed the normally
acceptable land use compatibility standard of 60
dBA Ldn. The interior traffic noise levels at the

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Policy or Program Compliance
proposed residences would be less than 45 dBA
Ldn.

Program NS-1.2d Noise Mitigation. Consider
mitigation measures for new projects or land
uses that would cause a substantial increase in
noise (i.e., cause an increase above 60 dBA Ldn or
cause an increase of 5 dBA Ldn or more in the
ambient noise levels) in adjacent residential
areas or in residential areas affected by traffic
generated by the project.

Yes. As described in traffic noise analysis above,
with project traffic trip additions, noise levels
along the segments of Yount Street would increase
by less than 2 dBA over existing ambient noise
levels; all other roadway segments would increase
by less than 1 dBA at nearby land uses. Existing
land uses adjacent near the project site would not
be exposed to significant project traffic noise
increases or exceed 60 dBA CNEL. Therefore, no
mitigation measures to reduce traffic noise are
required.

Program NS-1.2f Construction Best Practices.

During review of development, infrastructure,
and other projects involving construction
activities, determine if proposed construction
projects could exceed the Town’s Noise
Ordinance standards at nearby residences and
sensitive receptors and, if necessary, require
mitigation measures in addition to the standard
best practice controls.

Yes. A construction noise analysis was completed
which compared project-generated noise levels to
the Town’s ordinance standards and General Plan
policies. The project’s construction noise could
temporarily exceed the Town’s noise ordinance
standards at adjacent properties, which is
common for new development. The Town will
implement project-specific measures pursuant to
Program NH-1.2d (Construction Noise) that will
reduce construction noise from the project to
meet the Town’s standards.

Policy NS-1.3 Vibration Impacts of
Development. Reduce vibration impacts from
demolition and construction projects.

Yes. Refer to Program NS-1.3a.

Program NS-1.3a Vibration Mitigation. Require
new development to minimize vibration impacts
to adjacent uses during demolition and
construction. For sensitive historic structures, a
vibration limit of 0.08 in/sec PPV (peak particle
velocity) will be used to minimize the potential
for cosmetic damage to the building. A vibration
limit of 0.30 in/sec PPV will be used to minimize
the potential for cosmetic damage at buildings
of normal conventional construction.

Yes. A construction vibration analysis was
completed for the project, as described in the
above discussion. The analysis shows that
construction vibration levels would be below the
thresholds outlined in this program at adjacent
buildings and the historic Town Hall building onsite.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to noise.

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3.12 POPULATION AND HOUSING
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
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)?
LTS Yes
b) Displace substantial numbers of existing people or housing, necessitating the construction of replacement housing
elsewhere?
LTS Yes
Key: LTS = less than significant

DISCUSSION
The Certified EIR concluded that the adopted General Plan would result in less-than-significant impacts on inducing substantial unplanned population growth and would not displace people or housing.

At full buildout, the proposed General Plan would accommodate approximately 231 new residential units and 169,646 square feet of new non-residential building square footage within the town limits. This equates to approximately 439 residents and 325 employees at full buildout. The project would increase the Town’s population by 240 residents11 and 31 employees,
12 which is within the General Plan buildout evaluated in the Certified EIR.

Additionally, future development is anticipated to occur through implementation of the General Plan 1) within the change areas identified in Section 5.3, Change Areas, of the General Plan Land Use Chapter, and 2) on vacant and infill sites throughout the Town. The project site is considered an infill site; therefore, the project would be within the anticipated growth area in the adopted General Plan.

The Certified EIR also recognizes that while the adopted General Plan may result in development that would remove residences, development under the adopted General Plan would result in an increase in the total number of residences and provide housing opportunities for persons that may be displaced as a result of development. There are currently no residences on the project site; therefore, the project would not result in the displacement of substantial numbers of existing people or housing. Accordingly, the project would not result in a new 11 150 units*1.6 persons per resident from (Department of Finance 2025) = 240 residents 12 11,000 square feet/350 square feet per employee (County of Napa 2014) = 31 employees

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significant impact or a substantial increase in the severity of the existing impacts analyzed in the Certified EIR related to population and housing.

MITIGATING POLICIES ON MEASURES APPLICABLE TO THE PROJECT There are no mitigating policies or programs that are applicable to the project.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to population and housing.

3.13 PUBLIC SERVICES
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
a) Result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times, or other performance objectives for any of the public services:

Fire protection? LTS Yes
Police protection? LTS Yes
Schools? LTS Yes
Parks? LTS Yes
Other public facilities? LTS Yes
Key: LTS = less than significant

DISCUSSION
The Certified EIR found that the adopted General Plan would have a less-than-significant impact on fire protection services, police protection services, schools, parks, and other public facilities.

The primary purpose of the public services impact analysis is to examine the impacts associated with physical improvements to public service facilities required to maintain acceptable service ratios, response times or other performance objectives. Public service facilities need improvements (i.e., construction, renovation, or expansion) as demand for services increase.

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Increased demand is typically driven by increases in population. The proposed project would have a significant environmental impact if it would exceed the ability of public service providers to adequately serve residents, thereby requiring construction of new facilities or modification of existing facilities.

As discussed in Section 3.12, Population and Housing, the project would result in a net increase of 150 dwelling units and 11,000 square feet of retail/restaurant and civic uses resulting in a net increase of approximately 240 residents and 31 employees. Based on Table 1-1, General Plan Land Use Development Assumptions, the remaining development capacity allowed in the General Plan area for residential uses is 216 units and approximately 78,980 square feet for commercial uses. Therefore, the project would not exceed the maximum buildout potential evaluated in the Certified EIR. As described in the Certified EIR, adopted General Plan includes a range of policies and programs that future development would funds its fair share of services and impacts to public services would be less than significant. Because impacts to public service providers were determined to be less than significant in the Certified EIR and the proposed project would not exceed the buildout considered in the Certified EIR, impacts to public service providers would also be less than significant.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.13, Public Services and Recreation, of the Certified EIR.

Policy or Program Consistency Finding
Policy LU-3.1 Future Growth Conditions. Allow
future development where: it contributes to
walkability, view corridors, and an active
streetscape; the Town has capacity to provide
necessary public services; natural, historic, and
cultural assets are protected; the costs and
revenues associated with new development are
balanced; and impacts to traffic circulation are
mitigated.

Yes. As discussed in this Addendum, the project
would include infill housing and jobs in a walkable,
central part of Town and contribute to the
pedestrian experience with new sidewalks and
pedestrian facilities; would not exceed the buildout
evaluated in the Certified EIR; would protect
natural, historic, or cultural assets in Yountville; and not result in transportation or circulation impacts.

Policy OS-1.2 New Development. Evaluate
proposals for new development to maximize onsite recreational space or access to recreational opportunities in the area, including trails. New
residential development shall contribute
towards communitywide park facilities. Maintain
or exceed a recreation standard of 5 acres of
park and recreation facilities per 1,000 residents.

Yes. The project would not exceed the buildout
evaluated in the Certified EIR. While the project
would result in a loss of 48,100 square feet of open
space as shown in Table 2-1, the project would
include a civic promenade, open space areas, a new
public pool and accommodate the relocation of the
public dog park resulting in a 91,900-square-feet (2
acres) of open space. Accordingly, because the
project would add only 240 new residents it would

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Policy or Program Consistency Finding
be required to contribute 1.1 acres of park and
recreation space, the project would contribute to
maintaining the Town’s park standards.

Policy OS-2.2 Existing Open Space. Preserve and
protect existing open space areas, including
parks, trails, greenways and Hopper Creek,
shown in Figure OS-1 Parks and Open Space
Areas.

Yes. The project would not encroach on any existing
open space and would expand the public spaces
available to residents and visitors to Yountville.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to public services.

3.14 RECREATION
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
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? LTS Yes
b) Include recreational facilities or require the construction or expansion of recreational facilities which might have an adverse physical effect on the environment?
LTS Yes
Key: LTS = less than significant

DISCUSSION
The Certified EIR concluded that the adopted General Plan would result in less-than-significant impacts on existing neighborhood and regional parks, and could require the construction or expansion of recreational facilities as the town grows.

As discussed in Section 3.12, Population and Housing, the project would result in a net increase of 150 dwelling units and 11,000 square feet of retail/restaurant and civic uses resulting in a net increase of approximately 240 residents and 31 employees. Based on Table 1-1, General Plan Land Use Development Assumptions, the remaining development capacity allowed in the General Plan area for residential uses is 216 units and approximately 78,980 square feet for commercial uses. As described in Section 2.3.2, Open Space, Recreation, and Landscaping, the project would include on-site public recreation which would help to offset the project’s fair

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share of impacts to parklands. Therefore, considering the proposed project’s provision of onsite public open space and recreational facilities, in conjunction with the collection of any required impact fees that support the Town’s parks and recreation fund, the impacts to the Town’s recreational facilities would be less than significant.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.13, Public Services and Recreation, of the Certified EIR.

Policy Consistency Finding
Policy OS-1.2 New Development. Evaluate
proposals for new development to maximize
on-site recreational space or access to
recreational opportunities in the area, including
trails. New residential development shall
contribute towards communitywide park
facilities. Maintain or exceed a recreation
standard of 5 acres of park and recreation
facilities per 1,000 residents.

Yes. The project would not exceed the buildout
evaluated in the Certified EIR and as such would
not exceed the Town’s park standards. The project
would include a civic promenade, open space
areas, a new pool and accommodate the
relocation of the public dog park and would
contribute towards meeting the Town’s park and
recreation facilities.

Policy OS-2.1 Open Space. Establish open space
within unbuilt parcels where needed to
reinforce or extend the existing network of
open space throughout the town.

Yes. See Policy OS-01.2.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to recreation.

3.15 TRANSPORTATION
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
a) Conflict with a program, plan, ordinance or policy addressing the circulation system, including transit, roadway, bicycle and pedestrian facilities?
LTS Yes
b) Conflict or be inconsistent with CEQA Guidelines Section 15064.3, subdivision (b)?
2018 CEQA
Question Yes

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Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
c) Substantially increase hazards due to a geometric design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment)?
LTS Yes
d) Result in inadequate emergency access? LTS Yes
Key: LTS = less than significant

DISCUSSION
The Certified EIR did not include an evaluation of vehicle miles traveled (VMT) pursuant to criterion (b) because this criterion was not compulsory until 2020 and Yountville had not yet adopted VMT-based significance thresholds or begun implementation of the new transportation-related CEQA guidelines. With the passage of Senate Bill (SB) 743 (September 2013), which was codified in PRC Section 21099 (CEQA Statute), and the subsequent adoption of revised CEQA Guidelines (December 2018), level of service can no longer be used as a criterion for identifying significant transportation impacts for most projects under CEQA. SB 743 changed the focus of transportation impact analysis in CEQA from measuring quality-of-life impacts to drivers, to measuring the physical impacts of driving on the environment. Changes in law, regulation, or guidelines adoption are not “new information” as that term is used in CEQA Guidelines Section 15162 if the information about the issue (i.e., VMT) was known or should have been known at the time EIR was certified (in this case 2019). The Certified EIR included a discussion of the generation of additional daily automobile trips in Chapter 3.14, Transportation, of the Certified EIR.

Plans and Policies Addressing the Circulation System
The Certified EIR recognized that with the additional traffic generated under existing plus General Plan buildout and cumulative plus General Plan buildout conditions, the SR 29 and Madison Street intersection would not operate at an acceptable level of service. The Certified concluded that since there was no certainty that recommended interchange improvements would be completed since there was no funding mechanism for the improvements and the Town did not have the jurisdiction to implement the interchange improvements, the conflict with the Town’s adopted General Plan Chapter 7, Mobility, Table MO-1, Intersection Level of Service Criteria, was considered significant and unavoidable.

The Certified EIR also acknowledged that implementation of the adopted General Plan would not conflict with the Town’s Bicycle Master Plan, the Napa County Transportation and Planning Agency Countywide Bicycle Plan, the Napa Countywide Pedestrian Plan, or other plans and

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policies to address public transit, bicycle, and pedestrian facilities. The Certified EIR concluded that with the implementation of applicable plans and policies related to public transit, bicycle, and pedestrian facilities, the buildout of the adopted General Plan would not conflict with a program, plan, ordinance or policy addressing these facilities. The impact was considered less than significant.

Nearby transit includes the VINE bus system’s Route 10 Up Valley Connector which is operated by the Napa County Transportation and Planning Agency (NCTPA), and the Yountville Bee Line, which is an on-demand transit service (shuttle) within Yountville. The nearest bus stops are on Washington Street, within 0.2 miles of the site. Bicycle facilities in the project area include a multi-use path which is adjacent to Hopper Creek and connects to Yount Street. A planned bicycle facility would be on Finnell Road. Pedestrian facilities include the multi-use path along Hopper Creek and sidewalks along Finnell Road and Yount Street.

The project would improve pedestrian facilities and include the replacement of existing sidewalks on Finnell Road and Yount Street along the project frontages. In addition, the project would also add raised crosswalks at Webber Street and Yount Street and Humboldt Street and Yount Street. In addition, the project would repair the existing crosswalk, mid-block on Finnell Road. The project would add a new graveled path adjacent to the existing Hopper Creek trail.

Furthermore, the project would include a pedestrian/bicycle path that extends from Yount Street, through the northern end of the property, to the existing Hopper Creek trail (a pedestrian and bicycle path).

The project would not interfere with any existing or planned pedestrian, transit, or bicycle facilities (such removing a transit stop, sidewalk or bus stop) described in the Town’s Circulation Element, NVTA’s Countywide Bicycle Plan (which includes the Town’s Bicycle Plan), or NVTA’s Countywide Pedestrian Plan (which includes the Town’s Pedestrian Plan). Therefore, the would not conflict with a program, plan, ordinance or policy addressing these facilities and the impact would be less than significant. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR with respect to a conflict with a plan, policy, or ordinance addressing the circulation system.

Vehicle Miles Traveled
The potential for the project to conflict or be inconsistent with CEQA Guidelines Section 15064.3, subdivision (b) was evaluated based on the project’s VMT performance metrics.

The Town applies the VMT significance criteria and screening measures in a Memorandum that outlines the Town’s VMT policy, which was developed in coordination with NVTA. For residential development, a significant VMT impact may occur if the project’s home-based VMT per capita exceeds 85 percent of the Yountville town average of 15.98 VMT per capita, which corresponds to a significance threshold of 13.58 VMT per capita. Applicable VMT performance metrics and averages were obtained from the Solano Napa Activity-Based Model (SNABM).

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The project would also include up to 11,000 square feet of non-residential space that is expected to include a mix of food-oriented commercial space, local-serving service uses, and civic uses such as a town archive and/or art studios. Pursuant to the Town’s VMT policy, these types of uses would qualify as local-serving retail and can be screened from further VMT analysis. The local-serving retail uses included in the project have a total floor area of less than 50,000 square feet and have a less-than-significant impact on VMT since the uses serve the surrounding area and either shift or reduce, rather than generate new, VMT.

The project site is located within traffic analysis zone (TAZ) 159 of the SNABM model, which has an unadjusted baseline VMT per capita of 15.99 miles. This value forms the basis upon which project-specific adjustments to VMT are made. The VMT associated with a residential development is influenced by its density. The project’s VMT per capita was adjusted to account for residential density using a methodology contained in the publication Handbook for Analyzing Greenhouse Gas Emission Reductions, Assessing Climate Vulnerabilities, and Advancing Health and Equity, California Air Pollution Control Officers Association. This methodology was developed in consideration of research that has shown per capita VMT to reduce as residential density has increased. Based on this methodology, density was calculated by dividing the proposed 150 units by the 7.7-acre residential portion of the project site. The resulting 19.5 units per acre density was calculated to correspond to a 25.1 percent reduction in baseline per capita VMT according to the CAPCOA methodology.

Accounting only for the reduction associated with the project’s residential density, the baseline residential VMT per capita for the project would be reduced from 15.99 VMT per capita to 11.98 VMT per capita, which is below the VMT significance threshold of 13.58 VMT per capita.

Accordingly, the project would result in a less-than-significant VMT impact.

Geometric Design Features
The Certified EIR concluded that future development under the adopted General Plan would be required to comply with the adopted General Plan, Land Use Code, and applicable state and local regulations related to design standards pertaining to a transportation improvements and safe intersections. The impact was considered less than significant.

The project would include a driveway on Finnell Road and Yount Street. The driveway would be at least 24 feet wide, which is consistent with the Town’s design standards for residential and commercial developments. The project would include pedestrian access from the proposed sidewalks on Yount Street and Finnell Road, in compliance with adopted General Plan Policy MO-1.2. The project also includes traffic calming improvements such as the installation of a new speedtable at Finnell Road, adjacent to Hopper Creek, to reduce vehicle hazards, in accordance with Policy MO-2.1. Therefore, with the implementation of General Plan policies, the project would have a less-than-significant impact with respect to hazards related to the project’s geometric design. The project would not result in a new significant impact or a substantial

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increase in the severity of the impacts that were analyzed in the Certified EIR related to the geometric design hazards.

Emergency Access
The Certified EIR acknowledged that General Plan buildout could result in an increase in the volume of users accessing the transportation network. The Certified EIR concluded that with the implementation of General Plan policies that ensure adequate emergency access, buildout of the adopted General Plan would result in a less-than-significant impact with respect to emergency access.

The project would include one project driveway on Finnell Road and a second project driveway on Yount Street. The proposed driveways would be at least 24 feet wide, in accordance with the Town’s design standards, and would provide adequate access for emergency vehicles. The project would have a less-than-significant impact with result to emergency access. The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to emergency access.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.14, Transportation and Circulation, of the Certified EIR.

Policy or Program Consistency Finding
Policy MO-1.4 Circulation Network Impact
Analysis. When analyzing impacts to the
circulation network created by new
development or roadway improvements,
consider the needs of all users including those
with disabilities, ensuring that pedestrians,
bicyclists, and transit riders are considered at an
equal level to the needs of automobile drivers.

Yes. In analyzing the project’s impacts to the
circulation network, the impacts to pedestrian,
bicycle, and transit facilities and riders were
considered. The project would improve pedestrian
facilities by replacing the existing sidewalks on
Yount Street and Finnell Road, along the project
frontages to improve pedestrian safety. The project
would also add a graveled pedestrian path adjacent
to the existing Hopper Creek trail.

The project will also include raised crosswalks at the
at Webber Street and Yount Street and Humboldt
Street and Yount Street, and improvements to an
existing sidewalk mid-block on Finnell Road. Bus
stops are located on Washington Street, within
walking distance of the site. The project would
improve the connection to bicycle facilities; the
project would include a path that connects from

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Yount Street, along the northern end of the site, to
Hopper Creek trail, a pedestrian and bicycle path.

Policy MO-1.6 Safe Travel. Maintain safe travel
conditions for all modes of travel.

Yes. The pedestrian and bicycle facilities
improvements discussed in Policy MO-1.4 will
comply with the Town’s design standards and would
be safe for pedestrians and bicycles to travel.

Policy MO-2.2 Viewpoint. Retain the viewpoint
of pedestrians and bicyclists as the primary
perspective when identifying any traffic
improvements.

Yes. See Policy MO-1.4. The pedestrian and bicycle
facilities improvements will improve safety and
connections to existing facilities.

Policy MO-6.3 New Development. Require
development projects to construct sidewalks
and walkways on and offsite in order to maintain
consistency with the Town’s Bicycle Plan and
Pedestrian Plan, and as dictated by the location
of transit stops and common pedestrian
destinations.

Yes. The project would replace new sidewalks with
existing sidewalks on Yount Street and Finnell Road
(see Policy MO-1.4). The project’s bicycle and
pedestrian improvements are consistent with the
Town’s Circulation Element and NVTA Countywide
Bicycle Plan and Countywide Pedestrian Plan (which
includes the Town of Yountville Bicycle Plan and
Pedestrian Plan).

Policy MO-6.5 Gaps in Pedestrian Network.

With the exception of the Old Town Historic
district, gaps in sidewalks and walkways should
be identified and a plan to fill these gaps
completed.

Yes. See Policy MO-1.4. The project would replace
new sidewalks with existing sidewalks along the
project frontage to improve pedestrian facility
connectivity.

Policy MO-6.10 Pedestrian Crossings. Enhance
the safety of pedestrian crossings in the Town.

Yes. See Policy MO-1.4.

Policy MO-7.1 Bicycle Plan. Establish and
maintain bicycle facilities that are consistent
with the network depicted in the Town’s Bicycle
Plan.

Yes. See Policy MO-6.3.

Policy MO-7.3 Bicycle Parking. Bicycle parking
facilities such as bike racks, bike lockers, and
secure bike corrals shall be provided at locations
where there is a concentration of residents,
visitors, students, or employees.

Yes. The project would include bicycle parking
facilities such as bike racks, bike lockers, and secure bike corrals.

Policy MO-7.4 Connections with Residential
Areas. Provide pedestrian and bike connections
which link residential areas with businesses and
recreational facilities, including parks, schools,
the US Post Office, Town Hall, Community Hall
and the commercial core.

Yes. The project includes a pedestrian/bicycle path
that connects from Yount Street, and transects the
northern portion of the site, and connects to the
multi-use path/trail adjacent to Hopper Creek.

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3. ENVIRONMENTAL ANALYSIS
December 2025 3-99
Policy or Program Consistency Finding
Program SH-1.3f Fire Risk in New Development.

1. Review all development proposals for fire
risk and require mitigation measures to
reduce the probability of fire. Encourage
attractive native and drought-tolerant, lowmaintenance landscaping responsive to fire hazards. Require all new development to
meet the adopted State and local fire codes.

2. Require adequate access for emergency
vehicles, adequate street width and vertical
clearance, driveway access and parking
restrictions for new development.

3. Require sprinkler systems for new
commercial and residential development
and substantial remodels and additions.

Yes. The project would include 24-foot wide
driveways on Yount Street and Finnell Road, in
accordance with the Town’s standards for residential
and commercial driveways. The project’s driveway
design is consistent with the Town’s design
standards; therefore, the project would provide
adequate emergency vehicle access.

In addition, the project’s proposed buildings would
include fire sprinkler systems. The project would
include drought-tolerant landscaping which will
consist of fire resistant materials. The project will
comply with adopted the California Fire Code and
YMC Chapter 15.32.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to transportation.

3.16 TRIBAL CULTURAL RESOURCES
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
a) Cause a substantial adverse change in the significance of a tribal cultural resource, defined in PRC Section 21074 as either a site, feature, place, cultural landscape that is geographically defined in terms of the size and scope of the landscape, sacred place, or object with cultural value to a California Native American tribe, and that is:
i) Listed or eligible for listing in the California Register of Historical Resources, or in a local register of historical resources as defined in PRC Section 5020.1(k), or
LTS Yes
ii) A resource determined by the lead agency, in its discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of PRC Section 5024.1. In applying the criteria set forth in subdivision (c) of PRC Section 5024.1, the lead agency shall consider the significance of the resource to a California Native American tribe.

LTS Yes

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3. ENVIRONMENTAL ANALYSIS
3-100 PlaceWorks
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
Key: LTS = less than significant

DISCUSSION
The Certified EIR recognized that cultural resources were identified within the General Plan area, according to files maintained by the NWIC. The cultural resources span both the prehistoric and historic periods and range from a Native American village site to historic period commercial buildings and homes and two historic districts. The Certified EIR also outlined that it has been generally held that prehistoric Native American sites are most likely to occur where several environmental factors combine to provide readily available resources, such as at the interface between valley and hills, as well as near sources of water (including creeks). The Certified EIR concluded that with the implementation of General Plan policies and programs that reduce impacts to cultural and tribal cultural resources, future development under the adopted General Plan would have a less-than-significant impact on these resources.

Senate Bill (SB) 18 requires local governments to notify California Native American tribes (on the contact list maintained by the NAHC), culturally and traditionally affiliated with the jurisdiction, of the opportunity to conduct consultations for the purpose of preserving, or mitigating impacts to, cultural places located on land within the local government's jurisdiction that are affected by the plan adoption or amendment.

In accordance with SB 18, the California Native American Heritage Commission (NAHC) was contacted on May 16, 2025 to request a Sacred Land Files (SLF) search for the project site. The SLF search indicates whether the California Native American tribes within the project area have recorded Sacred Lands in the SLF search. The NAHC indicated there was a positive result indicating that there is a Native American cultural resource in the vicinity of the project area. On May 28, 2025, notification letters were sent to the tribes (based on a list provided by NAHC) that included an invitation to consult about the project under SB 18. No tribes responded to the invitation for consultation after the 90-day period that the tribes are allowed by law to respond to a consultation request or indicated the presence of a tribal cultural resource on-site.

Therefore, no known tribal cultural resources (TCR) have been identified on the project site.

However, it is possible that the inadvertent discovery of TCRs could occur during project construction or ground disturbance. Therefore, the project specific measures for contractor awareness training and discovery of archaeological resources described in Section 3.4, Cultural Resources, of this Addendum would be implemented to reduce impacts to potential TCRs.

Programs OH-2.1d and OH-2.1e, which require the Town’s contractors to stop work in the event of an inadvertent discovery of significant cultural resources during construction or grading

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3. ENVIRONMENTAL ANALYSIS
December 2025 3-101
activities, would also be implemented to reduce impacts to cultural resources (which could include tribal cultural resources). With the implementation of the adopted General Plan programs and policies in this section and included in Section 3.4, Cultural Resources, of this Addendum, the project would have a less-than-significant impact on tribal cultural resources and would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to tribal cultural resources

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan programs identified in Chapter 3.5, Cultural and Tribal Cultural Resources, of the Certified EIR.

Policy or Program Consistency Finding
Program OH-2.1a Identification of Resources.

Work with the Northwest Information Center
and Native American Heritage Commission to
determine existence of significant archaeological
and cultural resources, including Native
American sacred sites and burial grounds.

Yes. A cultural resources records search was
completed at the NWIC for the project site and a
radius within 0.25-mile of the site, in May 2025.

No archaeological resources/cultural resources
were identified based on a records search of
previous cultural resources studies. A request to
complete a sacred land files SLF search was
submitted to NAHC in May 2025.

Program OH-2.1d Inadvertent Discovery of
Cultural, Paleontological, and Archaeological
Resources. Require new development,
infrastructure, and other ground-disturbing
projects to stop work and notify the Town in the
event that construction or grading activities
result in an inadvertent discovery of significant
historic, cultural, paleontological or
archaeological resources. Such resources shall
be examined by a qualified historian or
archeologist for potential protection and
preservation measures, and appropriate
measures shall be implemented to preserve,
relocate, and/or record the find, as appropriate.

Yes. The Town will implement project-specific
measures pursuant to Program OH-2.1b and OH2.1d (Discovery of Unrecorded Resources) which requires contractors to stop work and notify the
Town in the event that construction or ground
disturbing activities result in an inadvertent
discovery of unrecorded cultural/archaeological
resources (which could include tribal cultural
resources). The resources will be examined by a
qualified archaeologist, and appropriate measures
will be implemented to reduce impacts to these
resources to a less-than-significant level.

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3. ENVIRONMENTAL ANALYSIS
3-102 PlaceWorks
Policy or Program Consistency Finding
Program OH-2.1e Inadvertent Discovery of
Human Remains. Require new development,
infrastructure, and other ground-disturbing
projects to stop work and notify the Town in the
event that construction or grading activities
result in an inadvertent discovery of human
remains.

Yes. The Town will implement project-specific
measures pursuant to Program OH-2.1b and OH2.1e (Human Remains) during construction or ground disturbing activities in accordance with this
program. Contractors will be required to stop work
and notify the Napa County Coroner and the Town
in the event of an inadvertent discovery of human
remains (which could include tribal cultural
resources) occurs.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to tribal cultural resources.

3.17 UTILITIES AND SERVICE SYSTEMS
Would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
a) Require or result in the relocation or construction of new or expanded water, wastewater treatment or storm water drainage, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects?
2018 CEQA
Guidelines Yes
b) Have sufficient water supplies available to serve the project and reasonably foreseeable future development during normal, dry and multiple dry years?
LTS Yes
c) Result in a determination by the wastewater treatment provider which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments?
LTS Yes
d) Generate solid waste in excess of state or local standards, or in excess of the capacity of local infrastructure, or otherwise impair the attainment of solid waste reduction goals?
LTS Yes
e) Comply with federal, state, and local management and reduction statutes and regulations related to solid waste? LTS Yes Key: LTS = less than significant

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3. ENVIRONMENTAL ANALYSIS
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Construction or Relocation of New or Expanded Utility Systems The Certified EIR acknowledged that projected water supplies were adequate to meet buildout demand generated from implementation of the adopted General Plan. Therefore, the Certified EIR concluded that implementation and General Plan buildout would not result in the need to construct or expand water supply and treatment facilities that were not already described and accounted for in the Town’s Water Use Efficiency Plan. Accordingly, the impact was found to be less than significant.

The Certified EIR concluded that implementation of adopted General Plan policies and programs would ensure there is adequate stormwater drainage and flood control infrastructure to serve future development under the adopted General Plan and that future drainage and flood control infrastructure projects would not result in adverse environmental impacts. The impact of new or expanded stormwater drainage facilities was considered less than significant. In addition, the Certified EIR concluded that future development’s fair share contribution to wastewater infrastructure improvements would reduce impacts to wastewater infrastructure.

The project would drain to pervious surfaces including pervious pavement and bioretention areas on-site. Therefore, the project would comply with NPDES requirements and best management practices to reduce stormwater runoff, in accordance with adopted General Plan Policy OS-6.4 and Program OS-6.4a. Stormwater would then be directed to an existing outfall at Hopper Creek. The project would not require construction or relocation of new storm drains.

The project would include new water lines that would connect to an existing water main on Finnell Road. In addition, the project’s sewer lines would connect to a new sewer main on Finnell Road. Wastewater would flow to an existing sewer pump station, which would then be pumped to the Yountville WRF. The proposed project’s electric and telecommunication lines would connect to existing service lines along Yount Street and Finnell Road. Since the project’s proposed utilities would connect to existing Town’s utility systems that can accommodate the project, the project would not result in the construction or relocation of utility systems that would cause significant environmental effects. Therefore, the impact would be less than significant.

Water Supply
The Certified EIR concluded that future water demand from General Plan buildout is within the Town’s existing normal and dry year supply and future projects would implement General Plan policies and programs to ensure adequate public infrastructure, impacts associated with water supplies were considered less than significant.

Based on the projected water demand described in the Certified EIR, the water demand for residential development at General Plan buildout (i.e., 231 residential units) is estimated to be

57.3 acre-feet per year. Chapter 2, Introduction, Table 1-1, General Plan Land Use Development

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Assumptions, of this Addendum shows that 10 of the residential have been approved and, therefore, the remaining number of residential units allowed under the adopted General Plan is 216 units. The project would include the development of up to 150 residential units; therefore, the project would not cause an exceedance in the water projected demand for residential development under the adopted General Plan.

The projected water demand for approximately 81,580 square feet of commercial uses at General Plan buildout is 33.6 acre-feet per year, based on the Certified EIR. The project would include 11,000 square feet for commercial space (including retail, restaurant, and civic uses).

Therefore, the project would not cause an exceedance in water demand for the commercial uses. Given the Certified EIR concluded there is adequate water supply for the adopted General Plan buildout, and the project is within with the buildout assumptions evaluated in the Certified EIR, there would be sufficient water supplies available to serve the project. The impact related to water supply would be less than significant and the project would not result in a new significant impact or increase in severity of an impact related to water supply.

Wastewater
Wastewater within the town is primarily treated at the Joint Wastewater Treatment Plant (JWTP). Based on the analysis in the Certified EIR, the JWTP has an average daily flow (ADWF) design capacity of 0.55 million gallons per day (MGD) for normal flows and 2 MGD for high flows. The JWTP can accommodate up to 2.8 MGD through its primary system during peak wet weather conditions. Flows in excess of the JWTP’s secondary treatment capacity are stored in a

3.8-million-gallon effluent holding pond for later treatment.

The wastewater generation of 0.065 MGD associated with adopted General Plan buildout combined with 2017 flows would result in approximately 0.4305 MGD average daily flows, which is within the 0.55 MGD treatment capacity of the JWTP. Since project would be consistent with the development assumptions in the Certified EIR (as described in this section), the JWTP would have adequate wastewater treatment capacity for the project. The project would not result in an exceedance of wastewater flow projects for the adopted General Plan buildout.

Therefore, The project would not result in a new significant impact or increase in severity of an impact related to wastewater treatment capacity.

Solid Waste
The Certified EIR concluded that the adopted General Plan buildout would not exceed the permitted capacity of the Clover Flat Landfill serving Yountville and development under the adopted General Plan would comply with regulations related to solid waste. Therefore, impacts to solid waste were considered less than significant and no mitigation was determined to be necessary.

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3. ENVIRONMENTAL ANALYSIS
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The new growth under General Plan buildout would result in an increase of approximately 2,195 pounds per day of solid waste, which equals 1.1 tons per day or 401.5 tons of solid waste per year, as described in the Certified EIR. Since the project is consistent with adopted General Plan buildout development assumptions, the project would not exceed the General Plan buildout projections for solid waste and there would be sufficient landfill capacity to accommodate the project. Therefore, the impact related to landfill capacity is less than significant.

In addition, the project would include recycling and composting bins to encourage residents to reduce solid waste in accordance with adopted General Plan Policy OS-8.2. The project would comply with federal, State, and the Town’s statutes and regulations related to solid waste reduction. Therefore, the project impact would be less than significant with respect to compliance with federal, State, and local statutes and regulations related to solid waste.

MITIGATING POLICIES AND PROGRAMS APPLICABLE TO THE PROJECT As shown in the table, the project would be consistent with the applicable mitigating General Plan policies and programs identified in Chapter 3.15, Utilities and Service Systems, of the Certified EIR.

Policy or Program Consistency Finding
Program LU-3.6a Impacts of New Development
on Infrastructure and Services. Analyze project
impacts on infrastructure capacity and services
as part of CEQA review. If a project would result
in a significant deterioration of service or would
cause available capacity to be exceeded,
respond in one or more of the following ways as
permitted by State law:
a. Require project redesign in order to prevent
service from deteriorating or capacities
being exceeded, provided that all economic
use of the property is not prevented;
b. Condition the project on developer funding
of improvements needed to maintain
services and/or provide additional
infrastructure capacity;
c. Approve the project if it can be found that
the project will generate substantial
overriding public benefits, be in compliance
with all of the other goals and policies of the
General Plan, or benefit the public health,
safety, and general welfare of the
community.

Yes. This Addendum includes an analysis of impacts
to water, wastewater, stormwater, electric power,
telecommunications and solid waste facilities. The
analysis discussed in this section shows that given
the project would not exceed the maximum
buildout potential evaluated in the Certified EIR, the
project would result in a less-than-significant impact
on utility systems.

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Policy or Program Consistency Finding
d. Deny the project.

Policy OS-6.1 Adequate Water Supply. Ensure
there is adequate water supply and associated
infrastructure to meet the needs of existing and
future development.

Yes. Based on the analysis in Addendum there
would be adequate water supplies to serve the
project.

Policy OS-6.2 Groundwater Recharge. Preserve
and protect open space and, where appropriate,
other natural areas that assist in the recharge of
groundwater basins.

Yes. The project would result in a net addition of
pervious surfaces (including pervious pavement and
bioretention areas) at the site and, therefore,
improve groundwater recharge potential.

Program OS-6.3b Water-Efficient Landscapes.

Continue to encourage the use of native,
drought-resistant plants and water-efficient
landscapes in accordance with State
requirements.

Yes. The project would include drought-tolerant and
water efficient landscaping in accordance with State
requirements. The project includes a landscaping
plan which was reviewed and approved by a
certified arborist and a qualified landscape
architect.

Program OS-6.3c Reclaimed Water. Continue to
provide reclaimed water for irrigation purposes,
where possible.

Yes. There are no existing recycled water lines
adjacent to the site. Therefore, the use of reclaimed
water for irrigation is not feasible. However, the
project would include drought tolerant landscaping
to conserve water, in accordance with State
requirements.

Policy OS-6.4 Water Quality. Protect water
resources from pollution and sedimentation.

Yes. See Section 3.9, Hydrology and Water Quality,
of this Addendum.

Program OS-6.4a Best Management Practices.

Require new development, redevelopment, and
infrastructure projects to implement best
management practices as feasible, including lowimpact development techniques, the minimal use of non-pervious surfaces in landscape
design, and the integration of natural features
into the project design, to naturally filter and
biodegrade contaminants and to minimize
surface runoff into drainage systems and creeks.

Yes. See Section 3.9, Hydrology and Water Quality,
of this Addendum.

Program OS-6.4b NPDES Compliance. Ensure
that new development, redevelopment, and
infrastructure projects comply with the
requirements of the National Pollutant
Discharge Elimination System (NPDES) permit
and the applicable Stormwater Discharge System
Ordinance and do not substantially degrade
water quality.

Yes. See Section 3.9, Hydrology and Water Quality,
of this Addendum.

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Policy or Program Consistency Finding
Program OS-6.4c Permeable Surfaces.

Encourage use of pervious materials to aid in
stormwater treatment and infiltration.

Yes. See Section 3.9, Hydrology and Water Quality
of this Addendum.

Policy OS-8.2 Solid Waste Reduction. Encourage
solid waste reduction, recycling, food waste
recovery, composting of organic waste, and
reuse of materials.

Yes. The project would include recycling and
composting bins at the multi-family residences as
well as the retail, civic, and restaurant buildings.

Policy HO-10.1 Energy and Water Conservation.

Encourage energy and water conservation in the
design or modification of housing units.

Yes. The project would comply with the current
CBSC and include energy efficient features such as
solar PV panels and battery storage at the multifamily buildings. The project would include droughttolerant landscaping to conserve water used for irrigation.

Program SH-1.3g Water Supply for Fire Fighting.

Maintain an adequate water supply, fire hydrant
system, and water pressure to effectively
suppress fires.

Yes. The project would include fire hydrants at each
of the proposed buildings and maintain adequate
water pressure to suppress fires.

CONCLUSION
The project would not result in a new significant impact or a substantial increase in the severity of the impacts that were analyzed in the Certified EIR related to utilities and service systems.

3.18 WILDFIRE
If located in or near state responsibility areas or lands classified as very high fire hazard severity zones (FHSZ), would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
a) Substantially impair an adopted emergency response plan or emergency evacuation plan?
2018 CEQA
Question Yes
b) Due to slope, prevailing winds, and other factors, exacerbate wildfire risks, and thereby expose project occupants to pollutant concentrations from a wildfire or the uncontrolled spread of a wildfire?
2018 CEQA
Question Yes
c) Require the installation or maintenance of associated infrastructure (such as roads, fuel breaks, emergency water sources, power lines or other utilities) that may exacerbate fire risk or that may result in temporary or ongoing impacts to the environment?
2018 CEQA
Question Yes

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If located in or near state responsibility areas or lands classified as very high fire hazard severity zones (FHSZ), would the project:

Level of
Impact in
Certified EIR
Meets the
Conditions
for an
Addendum
d) Expose people or structures to significant risks, including downslope or downstream flooding or landslides, as a result of runoff, post-fire slope instability, or drainage changes? 2018 CEQA
Question Yes
Key: N/A = not applicable

DISCUSSION
The Certified EIR did not include an evaluation of wildfire impacts pursuant to these new questions, because these criteria were not introduced to the CEQA Guidelines Appendix G, Environmental Checklist Form, and effective until December 28, 2018, and therefore not required by CEQA at that time. As previously described, changes in law, regulation, or guidelines adoption are not “new information” as that term is used in CEQA Guidelines Section 15162 if the information about the issue (i.e., wildfire) was known or should have been known at the time the original EIR was certified. Chapter 3.8, Hazards and Hazardous Materials, of the Certified EIR addressed the impacts to wildfire hazards associated with buildout of the adopted General Plan. Impacts were found to be less than significant with full buildout of the adopted General Plan, which includes the project, with implementation of General Plan policies and programs, that would ensure potential wildland fire hazards are mitigated through requirements for adequate water supply and water flow availability, ensuring adequate emergency access, adequate fire protection services, and ensuring public awareness regarding fire safety.

The town is not in or near a State Responsibility Area. The town is in a Local Responsibility Area (LRA) that is served by the Napa County Fire Department (NCFD), which contracts with California Department of Forestry and Fire Protection (CAL FIRE) for fire protection services. The majority of the town, including the project site, is not categorized as a fire hazard severity zone (FHSZ) by CAL FIRE (California Department of Forestry and Fire Protection, 2025). Therefore, the project increase in the severity of wildfire-related impacts when compared to the Certified EIR as shown Chapter 3.8, Hazards and Hazardous Materials, development in the town is not subject to these standards of significance.
13 13 California Department of Forestry and Fire Protection website, https://experience.arcgis.com/experience/6a9cb66bb1824cd98756812af41292a0, accessed 10/26/25.

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3. ENVIRONMENTAL ANALYSIS
December 2025 3-109

MITIGATING POLICIES OR PROGRAMS APPLICABLE TO THE PROJECT While the Town has adopted General Plan policies and programs in place to ensure the protection of the residents from the effects of wildfire, no mitigating policies or programs are applicable to this topic given the project site is not in or near a very high wildfire hazard severity zone. Section 3.8, Hazards and Hazardous Materials, of this Addendum, under subheading “Wildfire” describes how wildfire is addressed in the Certified EIR.

3.19 MANDATORY FINDINGS OF SIGNIFICANCE
Would the project:

Level of
Impact in
Certified
EIR
Meets the
Conditions
for an
Addendum
a) Have the potential to substantially degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below selfsustaining levels, threaten to eliminate a plant or animal community, substantially reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory?
LTS Yes
b) Have impacts that are individually limited, but cumulatively considerable? (“Cumulatively considerable” means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects.) LTS Yes
c) Have environmental effects which will cause substantial adverse effects on human beings, either directly or indirectly? LTS Yes

DISCUSSION
With respect to biological resources and cultural resources, the project would not require the expansion of General Plan area boundaries that would result in a greater impact to biological or cultural resources, compared to the impacts identified in the Certified EIR. Mitigating General Plan policies, programs, and related measures described in Section 3.3, Biological Resources, and Section 3.4, Cultural Resources, of this Addendum would be implemented to reduce impacts to these resources to a less-than-significant level. As discussed throughout this Addendum, the project would not result in a new significant impact or a substantial increase in the severity of impacts, with respect to biological and cultural resources, described in the Certified EIR.

CEQA Guidelines Section 15355, Cumulative Impacts, defines cumulative impacts as two or more individual effects which, when considered together, are considerable or which compound

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or increase other environmental impacts. Cumulative impacts may result from individually minor, but collectively significant projects taking place over a period of time. Buildout of the project, in addition to past and pending projects since certification of the General Plan EIR, is within the net new buildout analyzed in the Certified EIR. The project would incrementally contribute to, but would not exceed, the cumulative impacts analyses in the Certified EIR.

Therefore, the project would not contribute to significant cumulative impacts when considered along with other projects constructed under the Certified EIR.

The project would be consistent with the adopted General Plan buildout projections and the impacts on human beings, directly and indirectly, would be consistent with the impacts described in the Certified EIR. The implementation of the required mitigating General Plan policies and programs specified in the Certified EIR and incorporated into this Addendum would reduce impacts to human beings, as well as the environment, to a less-than- significant level. As discussed throughout this Addendum, the project would not result in a new significant impact or a substantial increase in severity of impacts with respect to direct and indirect effects on human beings identified in the Certified EIR.

December 2025 4-1

4. CONCLUSION
As summarized below, and for the reasons described in Section 3, Environmental Analysis, of this Addendum, the Town has concluded that the project would not result in any new significant impacts not previously identified in the Certified EIR; nor would it result in a substantial increase in the severity of any significant environmental impact previously identified in the Certified EIR.

For these reasons, a subsequent EIR is not required, and an Addendum to the Certified EIR is the appropriate CEQA document to address the project.

4.1 SUBSTANTIAL CHANGES TO THE PROJECT
The project is not a substantial change to the adopted General Plan because it is within the study area and the buildout and population projections described and evaluated in the Certified EIR. Consequently, there are no substantial changes proposed to the adopted General Plan that will require major revisions of the Certified EIR due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects.

4.2 SUBSTANTIAL CHANGES IN CIRCUMSTANCES
The project would not result in substantial changes in physical circumstances that would cause a new significant impact or substantially increase the severity of a previously identified significant impact, and there have been no other changes in the circumstances that meet this criterion.

There have been no changes in the environmental conditions in the study area that were not contemplated and analyzed in the Certified EIR and that would result in new or substantially more severe environmental impacts in association with implementation of the project.

4.3 NEW INFORMATION
There is no new information of substantial importance (which was not known or could not have been known at the time of the Envision Yountville General Plan adoption on May 2019) that identifies a new significant impact; a substantial increase in the severity of a previously identified significant impact; mitigation measures or alternatives previously found infeasible that would now be feasible and would substantially reduce one or more significant effects of the adopted General Plan; or mitigation measures or alternatives that are considerably different from those analyzed in the Certified EIR and would substantially reduce one or more significant effects on the environment.

YOUNTVILLE COMMONS PROJECT:

ADDENDUM NO. 1 TO THE ENVISION YOUNTVILLE GENERAL PLAN EIR

4. CONCLUSION
4-2 PlaceWorks
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