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2025 Moss Landing Vistra Power Plant Fire

Webpage updated 05/05/2026 04:14 PM

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Update on Toxicologist Data Review and Next Steps

Post Date:07/08/2025 11:21 PM

The County of Monterey pursued a Human Health Risk Assessment (HHRA) related to the Moss Landing battery fire following direction from the Board of Supervisor’s on May 20, 2025.

Early input from these experts indicated that before an HHRA could be meaningfully completed, the first step was to perform a comprehensive review of the existing environmental data for completeness and quality. As a result, the County revised the project scope to focus on this data evaluation phase.

On June 25, 2025, the County received the data evaluation report from Cornerstone Earth Group outlining the results of this review, finding the data is not yet complete to support an HHRA and providing recommendations.

Cornerstone Earth Group, Data Review for Moss Landing Vistra Battery Fire, dated June 25, 2025 

The recommendations make clear that data used for a Human Health Risk Assessment (HHRA) needs a thorough technical analysis, as it should be a complete, high-quality dataset. The Environmental Health Bureau is now taking steps to strengthen and organize the data:

  • Conducting a full quality assurance review of all data included in the County’s public dashboard
  • Incorporating recommendations provided by the toxicologist to improve data organization and completeness
  • Implementing a policy that all new data will be reviewed and quality checked before being added to the dashboard

 

These efforts aim to ensure the county has a full database of reliable information should an HHRA be pursued in the future.

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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.