September 9, 2026
Ralph Robinson, Consulting Planner
City of Brisbane
50 Park Place
Brisbane, CA 94005
Via email: <rrobinson@brisbaneca.org>
Re: Scoping Comments on the Recirculated Draft Environmental Impact Report for the Quarry Innovation Center Project (SCH No. 2022060358)
Dear Mr. Robinson,
Thank you for the opportunity to comment on the scope of the Recirculated Draft Environmental Impact Report (EIR) for the Quarry Innovation Center Project.
The Sierra Club Loma Prieta Chapter, the San Mateo County Bird Alliance, the Santa Clara County Bird Alliance and Green Foothills have thousands of members in and around the City of Brisbane who are very concerned with keeping our ecosystems healthy for wildlife habitat as well as for residents. San Bruno Mountain is known ecologically as a rich, isolated "island" of biodiversity that supports rare endemic plant communities and endangered butterfly species. It is surrounded by urban development and this proposed project, rather than supporting this unique biodiversity, encroaches into this sensitive habitat area.
We are concerned that the revised project presents substantially different environmental issues from the previously proposed warehouse development and therefore requires a revised new project-specific environmental analysis. The project site is bordered on three sides by San Bruno Mountain State and County Park, a Habitat Conservation Plan area, and includes undeveloped hillside habitat supporting sensitive and threatened species.
The revised project replaces the previously proposed warehouse development with an approximately 895,000-square-foot light-fabrication building, a parking structure and surface parking around the facility. It also includes new roads, a 49.9-MW project substation, a PG&E switching station, and approximately 2,820 feet of new transmission line with three approximately 200-foot towers. Proposed uses, as indicated in the NOP, include assembling, processing, treating, and packaging, together with accessory research and development, storage, sales, distribution, and office uses.
Because the project has changed substantially, the EIR should evaluate the new project proposed rather than rely on assumptions, impact conclusions, or mitigation measures developed for the former warehouse project.
- Project Description, Development Footprint, and Alternatives
The substantial reduction in building area provides an opportunity to reduce habitat disturbance. The EIR should distinguish previously disturbed quarry lands from undeveloped or recovering habitat, quantify temporary and permanent disturbance, and explain why the overall disturbance footprint cannot be reduced commensurately with the reduction in building area.
The EIR should evaluate a reasonable range of alternatives that meaningfully reduce environmental impacts.
- This should include an alternative that redesigns access and other infrastructure to avoid permanent loss or degradation of Central Coast Riparian Scrub and provides meaningful riparian buffers.
- It should also evaluate limits on routine nighttime outdoor work, loading, construction, and other high-activity uses to reduce nighttime light, noise, traffic, and wildlife disturbance.
- It should evaluate whether the proposed industrial uses could be accommodated with significantly lower electrical demand and correspondingly reduced substation, switching, and transmission infrastructure.
- Biological Resources
Because the project is surrounded on three sides, actually on almost all sides at present, by natural habitat supporting multiple sensitive and threatened species, the EIR should conduct additional studies and analyses specific to the revised project and its new infrastructure.
Supplemental Biological Resources Evaluation and Field Study
The potential impacts of the revised project are sufficiently different from those of the former warehouse proposal to warrant a supplemental biological resources study and impact evaluation. This analysis should specifically address new project elements, including the substation, switching station and transmission line, as well as the manufacturing facility.
The field studies supporting the Draft DEIR analysis for special-status plant species occurred from 2018 through 2023. The DEIR states that colonization with these species could occur “if the project does not start construction within 5 years, (i.e., prior to 2029).” The biological basis for the five-year period is unclear. If this language is retained, the year should be corrected to 2028.
In addition, California Department of Fish and Wildlife (CDFW) stated in its comments on the Draft EIR that preconstruction surveys for special-status plants must be conducted within a year of initial grading, including during specific flowering periods. The EIR should incorporate this requirement into its analysis and mitigation.
Central Coast Riparian Scrub
CDFW previously recommended avoiding impacts to Central Coast Riparian Scrub to the greatest extent feasible and establishing protective riparian buffers. The redesigned project provides a new opportunity to achieve that avoidance.
The EIR should evaluate redesigning access and other infrastructure to avoid riparian habitat. Where impacts cannot be avoided, the EIR should demonstrate why avoidance is infeasible before relying on compensatory mitigation.
Wildlife Movement and Habitat Connectivity
The EIR should analyze the combined effects of buildings, roads, traffic, fencing, noise, lighting, drainage infrastructure, electrical infrastructure, transmission facilities, and human activity on wildlife movement between the quarry and surrounding San Bruno Mountain habitat.
The analysis should determine whether the project would interfere with wildlife movement or habitat connectivity within surrounding habitat, including connectivity protected or managed under the San Bruno Mountain Habitat Conservation Plan (HCP).
Nitrogen Deposition
The EIR should evaluate increased nitrogen deposition from automotive traffic and other project-related emission sources and its effects on surrounding San Bruno Mountain habitat. Increased nitrogen deposition can lead to overgrowth of invasive plants and degradation of grassland habitat, with potential effects on native vegetation and related HCP-covered species.
The Sierra Club supports the comments submitted by Ramona Arechiga, field ecologist and former habitat supervisor of San Bruno Mountain, on this issue, which apply equally to the revised project.
Artificial Light at Night
Artificial light at night (ALAN) should be analyzed as a biological impact of the revised project, including effects on birds, bats, insects, and other wildlife. ALAN can result in habitat fragmentation, barriers to movement, changes in reproductive and migratory behavior, attraction of insects and their predators to light sources, increased bird collisions, and other adverse effects.
The analysis should encompass the buildings, parking structures, roads, loading areas, security lighting, signage, vehicle headlights, project substation, PG&E switching station, and construction lighting. The EIR should evaluate light spillover under the maximum reasonably foreseeable operating conditions and identify specific measures to reduce impacts from both indoor and outdoor lighting.
Mitigation should minimize unnecessary nighttime lighting and establish enforceable requirements for shielding, warm-spectrum lighting, intensity, controls, dimming, curfews, and stringent illumination limits at habitat boundaries. Outdoor construction and other avoidable activities requiring substantial outdoor lighting should not occur at night except in emergencies or other extraordinary circumstances.
The DEIR does not propose specific ALAN mitigation other than referencing the Brisbane Dark Skies Ordinance. That ordinance is designed to protect residents and the local environment from spillover from commercial and residential properties and is not sufficiently rigorous to avoid impacts on wildlife in the heart of the San Bruno Mountain HCP from light generated by the proposed industrial project. For example, a manufacturing facility may operate in shifts, which could effectively exempt restrictions on outdoor lighting.
The EIR should therefore evaluate the project's wildlife impacts under maximum reasonably foreseeable nighttime operations and disclose and evaluate any anticipated exception from the City's Dark Skies Ordinance, including the activities or equipment for which such an exception would be required.
Bird-Safe Design
The approximately 895,000 square foot light fabrication building and parking structure adjacent to natural habitat create potential bird-collision hazards. The EIR should require bird-safe design addressing reflective glazing, transparent corners and passageways, glass railings, vegetation-facing glass, and other hazardous features. These requirements should be coordinated with ALAN mitigation.
- Noise and Vibration
The EIR should evaluate construction and operational noise and vibration affecting wildlife and adjacent habitat rather than relying solely on standards intended to protect people.
The analysis should include loading and trucks, mechanical and ventilation equipment, high-voltage power lines, transformers and switching equipment, generators, road traffic, construction, helicopters, and maintenance, with particular attention to continuous, tonal, low-frequency, and nighttime noise.
Noise and Physical Pollution from switching station acoustics (humming)
Transformers produce a continuous, low-frequency hum (magnetostriction). While usually localized, this noise pollution can affect neighboring communities or disturb nearby wildlife behavior if the station is positioned in a quiet rural area.
Electromagnetic Fields (EMF) and Localized Radiance
High-voltage equipment and connecting power lines emit extremely low-frequency electromagnetic fields. While EMF levels drop off sharply outside the property boundary, they can potentially affect highly sensitive local wildlife, or specific insect populations, directly bordering the perimeter and under the high voltage lines. Switching stations rely on tall structures, overhead busbars, portals, and incoming high-voltage transmission towers. These power lines emit low-frequency electromagnetic fields.The EIR should examine the effects on wildlife.
The EIR should disclose the maximum reasonably foreseeable nighttime operations and associated noise. Outdoor construction and other avoidable noisy activities adjacent to habitat should not occur at night. Appropriate operational noise limits should be established at habitat boundaries and should address tonal and other intrusive noise characteristics, not merely overall sound levels.
The EIR should also disclose and evaluate any anticipated exception from the City's Noise Control Ordinance and identify the activities or equipment for which such an exception would be required.
Energy and Electrical Infrastructure
The revised project introduces substantial new electrical infrastructure, including a 49.9-MW project substation, a PG&E switching station, approximately 2,820 feet of new transmission line, and three approximately 200-foot transmission towers.
The unusually large electrical infrastructure warrants a clear explanation of the electrical demand it is intended to serve. If the 49.9-MW substation is substantially larger than the demonstrated needs of the proposed 895,000-square-foot use, the EIR should disclose what future or alternative uses the infrastructure is intended to accommodate and analyze the reasonably foreseeable environmental consequences.
A 49.9-MW substation could theoretically supply:- 49,900 kW of instantaneous electrical load,
- At 895,000 sf of building area, that is approximately 55.8 watts per square foot if the entire 49.9 MW were attributable to the building.
- A”light industrial” building would normally plan for 10-15 watts per square foot.
For comparison, that is a very substantial power density for a building described as light fabrication/assembly, processing, treating and packaging. What specific electrical loads justify a 49.9-MW substation for an 895,000-square-foot light-fabrication facility? If the substation is being designed around a potential future use that is not clearly identified in the project description—such as a very electricity-intensive operation—the EIR should not simply analyze the building as ordinary light fabrication but as a potentially electric- intensive facility. Therefore, the EIR should include the following.
- An explanation of why a 49.9-MW substation is necessary
- Whether the substation has capacity for future uses, expansion, or additional tenants
- The EIR should disclose the purpose, capacity, ownership, and intended service area of the project substation, PG&E switching station, and associated transmission facilities, including whether they would serve only the project or provide capacity for uses beyond the proposed project
- Identification of the specific industrial processes assumed in calculating the electrical demand.
- Whether the electrical infrastructure could support a data center or other high-energy use, even if that use is not currently identified as part of the project
- The associated air-quality, greenhouse-gas, noise, electromagnetic-field, water-use, and land-use implications of the inclusion of the substation and its associated equipment
- Whether the project would require future backup generation for continuous power and, if so, the type, capacity, fuel, operating assumptions, testing protocols and emissions
- The EIR should also evaluate whether the proposed industrial uses could be accommodated with lower electrical demand and correspondingly reduced electrical infrastructure
Undergrounding of Transmission Lines
The EIR should evaluate both underground and overhead configurations for the proposed electrical connection and compare their respective impacts on sensitive biological resources. Where overhead facilities would create avian collision or electrocution risks, those impacts should also be evaluated. If any portion is proposed overhead, the EIR should explain why undergrounding is infeasible and require current Avian Power Line Interaction Committee (APLIC) guidance for siting, avian-safe design, collision and electrocution prevention, and line marking to minimize avian collision with lines as well as electrocution risks.
The EIR should also evaluate avian risks from the substation itself, including whether the design incorporates current avian-safe practices. APLIC notes that portions of substations can pose electrocution risks.
Conversely, undergrounding should not be presumed to be environmentally preferable where trenching, vegetation removal, soil disturbance, construction access, or long-term maintenance could adversely affect HCP habitat or covered species. Given that the San Bruno Mountain HCP specifically has a process for activities that disturb conserved habitat, identify whether the proposed electrical connection, regardless of whether it is overhead or underground, would trigger HCP review and what habitat disturbance would result.
The analysis should encompass the entire utility project, including towers, transmission corridors, construction and staging areas, access, vegetation removal, helicopter operations, and maintenance. The revised project proposes helicopters for installation of the off-site tower and transmission lines, and those operations should be included in the analysis.- Habitat Conservation Plan, Conserved Lands, and Ecological Reserve
The EIR should map all project components in relation to the San Bruno Mountain Habitat Conservation Plan (HCP) area, existing and proposed conserved lands, San Bruno Mountain State and County Park, and the San Bruno Mountain Ecological Reserve.
California Department of Fish and Wildlife (CDFW) previously identified uncertainty about whether Quarry Road expansion would affect the Ecological Reserve. The new EIR should resolve this question and analyze direct and indirect effects on protected lands.
The EIR should clearly identify the 82 acres proposed as public open space or conserved habitat, including the 36 acres proposed for protection by conservation easement, and describe the applicable protections and management.
The EIR should also evaluate nitrogen deposition from project-related traffic and other emission sources on surrounding San Bruno Mountain habitat, including potential effects on native vegetation and related HCP-covered species through increased invasive plant growth.
- Land Use, Zoning, and the Full Range of Permitted Industrial Uses
The proposed “light fabrication” designation encompasses assembling, processing, treating, and packaging, together with research and development and other accessory uses. Environmental impacts could vary substantially depending on the activities ultimately conducted. Since the 49.9KW electrical substation is substantially larger than the demonstrated needs of the proposed 895,000-square-foot “light fabrication” uses, the EIR should analyse what future or alternative uses the infrastructure could accommodate and analyze the reasonably foreseeable environmental consequences.
The EIR should therefore analyze the full range and reasonable maximum intensity of uses permitted by the proposed entitlements and allowable without subsequent discretionary environmental review.
The analysis should address, as applicable, 24-hour operations, process and stationary-source emissions, emergency and backup generators, hazardous materials and accidental releases, water demand and industrial wastewater, contaminated runoff, fire and wildfire ignition risk, operational noise and vibration, nighttime lighting, and truck and employee traffic.
The EIR should clearly identify the uses permitted or conditionally permitted under the proposed TC-3 zoning and evaluate whether uses materially different from those analyzed could subsequently be approved without additional environmental review.
If potentially more intensive uses are not analyzed, project approvals should contain enforceable restrictions preventing such uses without subsequent discretionary review and environmental analysis.
Hazards and Hazardous Materials
Phase I and Phase II site investigations were conducted, as well as targeted sampling of soil and groundwater in areas of imported fill and visual staining. While these investigations did not find substantial contamination, diesel and gasoline-range hydrocarbons were detected in many samples at levels exceeding Tier 1 Environmental Screening Levels. The site investigation records (Appendix E of the DEIR) report many instances where the borings encountered asphalt and construction debris below the ground surface. These findings indicate that there is a significant likelihood that unanticipated contamination will be encountered during site preparation and construction. The EIR should fully evaluate the requirements for investigating and managing unanticipated contamination if encountered, including potential lead paint, polychlorinated biphenyls (PCBs) , and other hazardous chemicals.
The EIR should also address concerns identified in the comments by the Brisbane Open Space and Ecology Committee, on the old DEIR, regarding water quality in the sediment ponds, including sediment and metals; stormwater runoff, including excess stormwater that will go to Guadalupe Valley Creek; and placement of bioretention basins above known asphalt contamination.
Electric Substation and Switching Station Hazards, Hazardous Chemicals and Spill Risks from Dielectric Oil Spills
The inclusion of an electric substation and switching station brings with them many industrial risks and impacts to wildlife and the environment that the EIR should identify and disclose in detail. Its principal risks are electrical, fire-related, chemical/oil-related, land-use issues and noise that affects nearby homes and wildlife. Utility-scale transformers, for example, contain thousands of gallons of mineral oil or synthetic fluids used for insulation and cooling. The EIR should evaluate the risk if a leak or catastrophic equipment failure occurs, since these non-biodegradable oils can contaminate the soil and nearby groundwater unless secondary containment pits (shielding pools) are built.
SF6 Gas Emissions
High-voltage circuit breakers in switching stations traditionally use Sulfur Hexafluoride (SF6), which is a highly potent greenhouse gas with a global warming potential 23,500 times greater than CO2. The EIR should study the impacts of even minor leaks during operation or maintenance and how these contribute directly to climate impact.
Fire Risk and Wildfires
The proposed 49.9-MW substation/switching station is immediately adjacent to San Bruno Mountain habitat, San Bruno Mountain has a significant wildfire history and is considered an area of wildfire concern.
San Mateo County's Community Wildfire Protection Plan says that the only documented major wildfires in the San Mateo Bayside planning area have occurred on San Bruno Mountain. It reports six wildfires larger than 100 acres since 1962, with the most recent major fire occurring in 2008.
Therefore, wildfire is a material issue that deserves a detailed site-specific analysis, rather than treating it as a routine industrial facility.
A substation/switching station located in a natural habitat can present a fire risk to the surrounding habitat, particularly if the area has dry grass, brush, woodland, or is in a wildfire-prone region. The EIR should analyse issues related to increased fire risks from the sub-station and the switching station. For example- How much transformer oil is on site? The gallons of oil in each transformer and the total.
- What happens if the largest transformer fails catastrophically? What is the fire-modeling analysis and expected flame/radiant-heat footprint.
- Is there secondary oil containment to prevent spilled oil from spreading and reduce the size of aresulting fire.
- How far is the equipment from vegetation and habitat? What extent of habitat will be cleared for fire safety?
- What is the wildfire hazard rating for the site?
- What happens when there are extreme winds and red-flag conditions?
- Can fire engines reach the facility from multiple directions?
- What fire protection is available if firefighters cannot safely approach energized equipment?
- Can the overhead transmission lines associated with the project create additional wildfire and wildlife risks beyond the substation itself.
Conversely, a wildfire entering the project area and electrical substation can be particularly important in a habitat area. Wildland fire can expose a substation to radiant heat, flames, smoke, and embers. IEEE's substation fire-protection guidance specifically identifies forest and grassland fires as external hazards to substations.
- Transportation and Traffic-Related Biological Impacts
The EIR should evaluate project-related traffic in relation to impacts on surrounding habitat and wildlife, including traffic associated with the full range of reasonably foreseeable industrial uses.
The analysis should address the contribution of automotive traffic to increased nitrogen deposition (covered also in Biological Impacts) as well as impacts from toxic brake and tire dust on surrounding San Bruno Mountain habitat. Traffic should also be considered in evaluating wildlife disturbance, wildlife mortality, nighttime activity, vehicle headlights and associated artificial light, and the combined effects of roads and traffic on wildlife movement and habitat connectivity.
- Combined Effects on Surrounding Habitat
The EIR should evaluate the combined effects of the project's components on surrounding San Bruno Mountain habitat rather than considering each component in isolation.
The analysis should address the combined effects of buildings, roads, traffic, fencing, noise and vibration, artificial light, drainage infrastructure, the project's large electrical substation, PG&E switching station, transmission lines and towers, construction and staging areas, helicopter operations, vegetation removal, and ongoing human activity.
The EIR should evaluate how these components collectively affect wildlife movement, habitat connectivity, habitat quality, nighttime conditions, and surrounding HCP-protected or managed habitat.
Conclusion
The revised Quarry Innovation Center Project presents an opportunity to reduce the impacts associated with the previous proposal while introducing new environmental issues and impacts associated with substantial electrical infrastructure and a broader range of potential industrial activities not specified at this time.
The revised project requires a project-specific analysis. The EIR should not carry forward assumptions, impact conclusions, or mitigation measures developed for the former warehouse proposal without demonstrating clearly that they remain applicable to the substantially changed project.
EIR should prioritize avoidance.
Most importantly, the EIR should prioritize avoidance. The reduced building area should result in a correspondingly reduced disturbance footprint. Central Coast Riparian Scrub should be avoided wherever feasible, meaningful riparian buffers should be provided, and wildlife movement and habitat connectivity should be maintained. The EIR should address the biological effects of nighttime light and noise, incorporate bird-safe design, evaluate nitrogen deposition, and fully analyze the effects of the new electrical infrastructure. Overhead lines versus undergrounding of the new transmission connection should be evaluated as the preferred avoidance approach.
Finally, the EIR must analyze the full range and reasonable maximum intensity of industrial uses that could be developed under the proposed entitlements without subsequent discretionary environmental review.
Where potentially more intensive uses are not analyzed, enforceable restrictions should prevent their approval without subsequent discretionary review and environmental analysis.
A complete and project-specific EIR addressing these issues is necessary
A complete and project-specific EIR addressing these issues is necessary to provide the public and decision-makers with a meaningful understanding of the revised project's potential effects on the sensitive habitat and wildlife surrounding the Quarry Innovation Center site.
We look forward to working with the City of Brisbane on helping to review this complex project in the critical habitat conservation area of San Bruno Mountain.
Respectfully submitted,
Gita Dev, Chair
Sustainable Land Use Committee
Sierra Club Loma Prieta
Alexandra Mendoza
Environmental Associate
Green Foothills
Naomi Goodman
Conservation Committee
San Mateo County Bird Alliance
Shani Kleinhaus
Environmental Advocate
Santa Clara Valley Bird Alliance