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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

County of Monterey Environmental Health Bureau Launches Environmental Testing and Monitoring Dashboard in Response to the Moss Landing Vistra Battery Fire

Post Date:05/20/2025 10:35 AM

A new GIS-based data dashboard is now online and available to the public to track where environmental testing and monitoring have taken place across the tri-county area in response to the 2025 Moss Landing Vistra Battery Fire. www.mtyhd.org/MossLandingBatteryFireDashboard

This new interactive dashboard allows the user to find results of water, soil testing and screening results collected throughout the area, beginning January 17, 2025. It will continue to be updated as additional testing results are analyzed, including the most recent samples collected as part of the Community Sampling Plan.

Due to the large volume of air monitoring data, the dashboard is being updated in phases. Some of this data has already been incorporated, and the remaining information will be added over time to ensure accuracy and completeness.

The GIS dashboard brings together data from a range of reliable sources to provide a comprehensive view of environmental conditions. Contributors include

  • U.S. EPA,
  • CTEH (Vistra’s environmental consultant)
  • the California Department of Toxic Substances Control (DTSC)
  • Monterey County Environmental Health Bureau
  • The Santa Cruz County Agricultural Commissioner
  • Santa Cruz County Environmental Health
  • Never Again Moss Landing, a grassroots community group, contributed screening data to support transparency and public awareness

County staff collaborated with toxicologists and subject matter experts at the Office of Environmental Health Hazard Assessment and California Department of Public Health to identify relevant regulatory criteria used to screen and/or assess for potential health-related concerns.  The dashboard can filter for test results that are at or above these health-related criteria or simply show when a detection occurred. 

Environmental assessment is a complex and ongoing process. Monitoring will continue throughout the debris removal and site cleanup phases. As a result, data updates may not always occur immediately or on a set schedule. 

Return to full list >>

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.