Monterey County presses for independent toxicology review as PG&E seeks to return Elkhorn battery system to service

Monterey County supervisors voted May 20 to have county staff commission an independent toxicologist to review air and soil sampling from the January Moss Landing battery storage fire after residents and state agencies raised ongoing public-health and cleanup concerns.

County staff and federal officials briefed the Board of Supervisors on ongoing debris and battery-module removal planning at the Vistra Moss Landing facility, and on air- and soil-sampling work that Monterey County Environmental Health is overseeing. PG&E representatives told the board the utility intends to re‑energize its Elkhorn battery system in June to support grid reliability; several supervisors and dozens of public commenters said more independent review and community involvement are needed before any restart.

Why it matters: The January blaze at Vistra’s Moss Landing battery facility — the largest battery storage fire in the United States — raised urgent questions about emergency response, air quality impacts and how to remove and dispose of damaged battery modules. Residents and local officials said communication and monitoring gaps during the response eroded trust and asked for stronger oversight and independent technical review.

County, state and federal update Kelsey (county staff member) told the board U.S. EPA is overseeing Vistra’s removal planning and that “each step of the process is being done in a very strategic fashion.” She said Vistra has been characterizing roughly 100,000 battery modules and is preparing plans for deenergizing, removal, treatment and off‑site transport under EPA oversight; she added earlier work removed asbestos from the burned building and that no battery material had yet been transported off site. (Kelsey is listed as county staff in the meeting file and spoke during the county’s briefing.)

Rick Encarnacion, director of the county’s Environmental Health Bureau, said county staff and state Department of Toxic Substances Control have accompanied the contractor that is collecting community soil samples. He told supervisors that 16 of 27 sample locations in phase 1 had been completed and that lab results were expected in several weeks. Nikki Fowler, the county GIS coordinator, said a public dashboard with sampling locations and screening-level comparisons had been published on the county’s incident website.

Public-health and community concerns Public Health Director Ed Moreno said the county’s community health survey — conducted Feb. 19–Mar. 6 and intended to inform the local response — remains under analysis; he said a public summary was expected to be posted in May. Multiple residents who spoke during general public comment said they remain ill, reported ongoing animal and crop impacts, and urged delay of any restart of nearby batteries until cleanup, restoration and independent health review are complete.

PG&E presentation and questions PG&E’s government relations representative Jasmine Venegas and regional vice president Teresa Alvarado briefed the board on PG&E’s Elkhorn battery storage system, a 182.5‑megawatt, 256‑“megapack” installation adjacent to the Vistra site. PG&E said Elkhorn is separated from Vistra’s building by concrete barriers, that the Elkhorn system disconnected automatically during the Vistra fire and has remained de‑energized, and that Elkhorn staff have implemented additional safety features including continuous air-monitoring and revised emergency action procedures.

Tim Wisdom, PG&E director of power generation, described prior work after a 2022 PG&E megapack incident at the Elkhorn site, saying a root‑cause analysis found a misinstalled vent that allowed water ingress and that PG&E had inspected every megapack, performed ‘‘dam’’ water tests, upgraded training with North Monterey County Fire District and added continuous emissions monitoring. "We have the ability to monitor continuously any chemical constituents and the wind direction," Wisdom said.

Board action and direction Supervisor John Church moved that the county engage an independent toxicologist to review the sampling and monitoring data produced so far; the motion was seconded, called and carried without recorded opposition. The board’s motion directs county staff to scope and hire an appropriate independent expert and to report back on costs and a timeline.

What the community asked for Residents and community organizations urged additional steps: independent third‑party air monitoring under authority of the Monterey Bay Air Resources District, public release of plume and dispersion modeling, health‑care support and restoration for impacted farms and households, a full community involvement plan for the cleanup, and delay of any restart until more of those steps are complete. Several speakers said prior monitoring and public information had been insufficient during the January incident.

Next steps County staff said they will work with county counsel and the budget office to scope the toxicologist contract and identify funding. U.S. EPA continues to oversee Vistra’s planning under its emergency response authority (CERCLA), and the county’s environmental health team will publish and update sampling results on the incident website as lab results are returned.

Residents may follow the county incident site for documents and the new GIS dashboard posted by the Health and Environmental Health bureaus.

Sources and attribution: County briefings and documents provided to the board May 20; statements to the board from Rick Encarnacion, Ed Moreno, Nikki Fowler (Monterey County), and PG&E representatives Jasmine Venegas, Teresa Alvarado and Tim Wisdom; public comments recorded in the May 20 meeting transcript.