Planning Commission opens public review of draft EIR for replacement groundwater well at 800 Carlisle Way

Sunnyvale — The Planning Commission on June 23 opened a public hearing on the draft environmental impact report (EIR) for a Cal Water project to replace a groundwater extraction well and install a roughly 56,000‑gallon, 24‑foot‑tall water storage tank and associated equipment at 800 Carlisle Way.

The draft EIR is focused on noise and vibration, and the consultant hired by the city concluded that drilling for the replacement well would create "significant unavoidable impacts," primarily because drilling activities could occur outside the city’s typical construction hours, project manager Nick Tostopia of David J. Powers and Associates said. The EIR’s analysis and associated appendices also examine air quality, geotechnical, arborist and other technical topics.

Why it matters: Commissioners and nearby residents pressed city staff and the applicant — California Water Service (Cal Water) — on the adequacy of the EIR, asking about nighttime lighting during drilling, disposal of drilling water, soil stability, potential soil or groundwater contamination and generator emissions. A member of the public said health effects were experienced previously near the site and submitted an eight‑page written comment asking the city to address what she described as multiple deficiencies in the draft EIR.

The project and the draft EIR Mary J. Prakash, the city planner assigned to the project, told commissioners the hearing’s purpose was to collect comments on the adequacy of the draft EIR, not to decide on the project itself. "The purpose of this hearing is to collect comments on the adequacy of the draft EIR," Prakash said. Staff said comments will be compiled and responded to in a final EIR, anticipated in July; separate planning commission and city council hearings will follow to decide on certification of the final EIR and any project permits.

Nick Tostopia, project manager for David J. Powers and Associates, said the city prepared an initial study that found no or less‑than‑significant impacts in most categories but identified potential significant impacts for noise and vibration. He said the EIR therefore focused on those topics and that the analysis concluded drilling could cause significant unavoidable noise impacts despite feasible mitigation measures. Tostopia also summarized alternatives analyzed in the EIR, including a no‑project option, a no‑project redevelopment scenario (assumed for analysis as four single‑family homes), and a shallower well alternative (600 feet rather than up to 1,000 feet).

Public and commissioner concerns Resident Mei Ling Stephan, who submitted written comments, urged the commission to address multiple perceived gaps in the draft EIR: "Nighttime lighting during the 20‑day drilling phase for up to 27 days should not have been ignored," she said, and added concerns about disposal of roughly 1,700,000 gallons of water, soil stability from land discharge, diesel exhaust and construction noise. Stephan told commissioners she had supplied an eight‑page written response asking the city to review the draft EIR’s analyses.

Commissioners asked staff and the applicant for specifics. Commissioner Sarony asked who initiated the project and who paid; staff said Cal Water initiated the proposal and that Cal Water hired consultants and paid for studies. Commissioners also asked whether the EIR compares noise from the proposed equipment with noise levels when the site previously operated; staff said Cal Water and the consultants visited an operational pump site and the EIR includes modeled and measured ambient noise and predicted increases, but the consultants do not have measurements from before 2016.

Several commissioners asked about contamination testing. The record includes a phase I environmental site assessment and other appendices; staff and the applicant said water and soil would be tested during drilling and well development under California requirements. The Cal Water representative said water samples would be tested under California Department of Public Health rules (identified in the hearing as "Title 22") and that regulators would not allow a contaminated source into service.

Applicant response and operational details A Cal Water representative, speaking on behalf of the applicant, said the prior well failed and could not be rehabilitated. The representative said the company attempted rehabilitation before proposing a new well and that the 1,000‑foot depth is necessary to restore the prior production capacity. On chemicals, the applicant said the station would store sodium hypochlorite and ammonia to disinfect water and described double containment, alarms and other safety features.

On generators and emissions, the applicant said newer diesel gensets and enclosures have substantially lower noise and emissions than older equipment and that the company now uses engines meeting Tier 4 emission standards. "The diesel gensets, they are not loud," the Cal Water representative said, and noted the district’s generators are tested periodically and are designed to meet current emissions requirements. City staff noted the EIR includes an air quality assessment and a health‑risk screening using Bay Area Air District thresholds; the consultant reported operational and construction emissions would fall below district significance thresholds with standard mitigation measures.

Process and next steps Staff reminded the public that the draft EIR public‑comment period closes at 5 p.m. June 30 and provided an email and mailing address for written comments. Prakash and staff said all comments received will be addressed in the final EIR, which the city expects to release in July; separate public hearings before the planning commission and city council will follow to consider certification of the final EIR and project permits. No decision or motion was taken at the June 23 meeting.

Community context and site details The project site is approximately 0.7 acres at 800 Carlisle Way in an R0 low‑density residential zoning district with a single‑story overlay; it is adjacent to Panama Park and surrounded by single‑family homes. The proposal would install a new groundwater extraction well drilled to about 800–1,000 feet below ground surface, a roughly 56,000‑gallon, 24‑foot‑tall storage tank, a booster pump, a backup generator and chemical storage buildings, and plant 12 new trees. Staff and the applicant said the consultant package includes a geotechnical feasibility study, a noise assessment (peer reviewed by the city), an air quality assessment and an initial study with appendices including a phase I environmental site assessment.

Quotations in this story come from the hearing transcript and were attributed to speakers during the June 23 Planning Commission meeting; the first reference to each person includes their full name and role.