A report concludes there’s no long-term health risk from the Moss Landing battery fire.

How many agencies does it take to analyze the aftermath of a fire at Vistra’s battery facility in Moss Landing?

Katie Rodriguez here, reporting that the answer is at least 13, not including the fire districts that responded to the Jan. 16, 2025, lithium-ion battery fire, not including Vistra and its consultants, and not including watchdog groups in Monterey and Santa Cruz counties.

Today, July 29, the County’s Environmental Health Bureau released its final, 343-page Preliminary Environmental Assessment report. The report examined whether the Moss Landing battery fire left off-site contamination posing long-term risks to people or the environment by analyzing nearby soils, sediments and surface waters.

In short, the report—prepared by Vistra’s environmental consultant Terraphase Engineering Inc.—found the samples did not pose an unacceptable risk to human health or the environment. 

“There is no hesitancy on the Environmental Health Bureau standing by this report,” said Ric Encarnacion, bureau chief and director of environmental health with the County during a July 29 news briefing. “It was highly coordinated. A lot of experts in the room at the state agency levels, and holding Vistra accountable in this report.”

If the study sounds familiar, it’s because a draft version was released earlier this year, in February. Since then, it has been updated in response to comments from various agencies.

The assessment looked at soil samples from 27 locations within a 10-mile radius of the site, along with sediment and surface water samples from 16 locations across Hester Marsh, a mosquito abatement observation area and one site north of the facility.

The complexity of understanding this event and its true impacts is intertwined with tracking who is doing the study, what is being studied and when. In the last year-and-a-half since the incident erupted, what’s frustrated residents is dealing with this patchwork of responses and what they see as conflicting evidence. 

The report released today offers a small window into what specific areas looked like months after the fire—the soil sampling began in May, and the sediment and surface water began in September, four and eight months after the January fire, respectively.

Many wonder about groundwater impacts; that is being managed by the Central Coast Regional Water Quality Control Board. Many also wonder about air quality; that has been looked at by Vistra’s environmental contractor CTEH, alongside the U.S. Environmental Protection Agency. The state’s Department of Toxic Substances has conducted its own preliminary soil and surface water testing, which found no hazardous conditions posing a risk to public health.

Next Friday, Aug. 7, researchers with EMBER (Estuary Monitoring of Battery Emissions and Residues) will host a public symposium featuring presentations from scientists at Moss Landing Marine Labs studying the impacts of the 2025 fire. Past presentations from this group have shown us that timing and sampling methodology matter—initially finding high concentrations of heavy metals that dispersed following heavy rainfall and tidal inundation. 

It’s worth noting that the cause of the fire is still unknown. If you'd like to attend the symposium by Zoom, you can do so here.