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Current Emergency Information

2025 Moss Landing Vistra Power Plant Fire

Webpage updated 08/11/2026 05:19 PM

Update: Characterization and Screening-Level Risk Evaluation Report Available

Commonly referred to as the Preliminary Environmental Assessment (PEA) Equivalent Report

Prepared by Terraphase Engineering, dated June 22, 2026

State agency partners reviewed the preliminary report and presented their initial findings to the County of Monterey Board of Supervisors on March 17, 2026. Terraphase then prepared the revised report dated June 22, 2026. The County does not expect further revisions.

Report Conclusions

Terraphase concluded that:

  • Chemicals measured in the sampled off-site soil, sediment, and surface water do not indicate lasting conditions expected to pose an unacceptable risk to people or ecological receptors.
  • For purposes of the risk evaluation, Terraphase used conservative, health-protective assumptions and treated measured chemical concentrations as if they were related to the fire.
  • Some nickel concentrations in sediment exceeded ecological screening levels in Hester Marsh and the Mosquito Abatement Observation Area. Terraphase attributed these results to natural variability and marsh conditions rather than lasting fire-related impacts.
  • No further human-health or ecological-risk evaluation, off-site investigation, or response action is warranted at this time for the sampled locations and environmental media.

These conclusions do not apply to conditions within the power plant property, groundwater, unsampled areas, or broader watershed conditions that may be addressed through separate regulatory work.

The report also reviewed air-monitoring and air-sampling data collected by U.S. EPA and CTEH. Terraphase stated that the limited number, generally low magnitude, and short duration of metals-in-air detections above screening levels did not indicate sustained exposure at levels of health concern.

Questions about the report or Terraphase’s conclusions may be submitted to EHB for referral to Terraphase: EHInfo@countyofmonterey.gov

State Agency Review of Report

The following agencies reviewed both the preliminary and revised reports:

Questions about each agency’s comments may be directed to:

U.S. EPA did not participate in the review because its oversight role is focused on on-site battery-removal activities. The County directed the off-site community sampling, and the participating CalEPA agencies reviewed the reports.

What happens next?

Publishing the revised report and state agency comments completes the County’s planned Community Sampling Plan and PEA-equivalent review process.

Completion of this County-directed process does not end other investigations or regulatory work. Separate work may continue regarding:

  • Groundwater;
  • Broader watershed or Elkhorn Slough conditions; and
  • Follow-up recommended or required by state agencies.

Separate work continues within the power plant property

Vistra’s battery removal and the related demolition, treatment, and preparation of batteries for recycling or disposal remain under U.S. Environmental Protection Agency oversight. Information and updates are available through the U.S. EPA Moss Landing Vistra Battery Fire response webpage:  https://www.epa.gov/ca/moss-landing-vistra-battery-fire

Latest News

Phase 2 of Moss Landing testing is set to start Mid-September

Focus of testing moves to marshes in the area

Post Date:09/15/2025 12:32 PM

Sampling of sediment, surface-water and pore-water around Moss Landing is set to begin in Mid-September.  This testing is a continuation of the County-led Community Sampling Plan in response to the January 2025 fire at the Vistra Battery Storage location.

Phase 1 consisted of testing  soil in neighborhoods and open spaces where people live, work, and play, with results expected to become available this month. Phase 2 shifts to marshes as these are ecologically sensitive areas that may have been impacted differently by the fire.

Fieldwork will be conducted by Terraphase Environmental on behalf of Vistra Corp. and is expected to require about five days total, spread across a two-week period. The work is scheduled in this manner because many of the marsh areas are tidal, meaning water levels and access conditions change daily. Spreading the effort out allows sampling to take place during favorable tides and ensures accurate, representative results while maintaining safe working conditions for field staff.

The approved plan for Phase 2 sampling, map, and Frequently Asked Questions are available at 2025 Moss Landing Vistra Power Plant Fire | County of Monterey, CA

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Timeline of Environmental and Public Health Response 

More Information

Stay Informed

To receive ongoing updates, residents are encouraged to register for alerts at Register | Portal Registration or visit Emergency | County of Monterey, CA. To check your zone, please visit Genasys Protect.

US EPA - Moss Landing Vistra Battery Fire Response

See Yellow Smoke?

Yellowish or brownish smoke can occur during turbine start-ups at the facility. When turbines start, emissions are temporarily higher than during steady operation—similar to starting a car engine. This is a normal, permitted part of facility operations. More information is available here

Concerns or Complaints?

You can submit a report to the Monterey County Health Department's Environmental Health Bureau online at http://www.mtyhd.org/mosslanding-concern-form or by leaving a voice message at 831-755-4505.