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  1. Home
  2. EPA in California
  3. Moss Landing Vistra Battery Fire
  4. Frequently Asked Questions

Ongoing Work: What are the contaminants of concern?

Return to: Frequently Asked Questions

We require Vistra to monitor and sample for the “contaminants of concern” we identified for the site, some of which are referenced in our order and in our notice (pdf) to Vistra.

These substances are based on:

  • what we know is in the batteries,
  • what we know are byproducts of battery fires
  • what was in the building that caught fire (Moss Landing 300).

In short, these are the contaminants we would expect in a flare-up (should one occur) and in the material in the burned building.

The contaminants of concern identified for the site, based on our current knowledge, include:

  • particulate matter from the fire and ash and as an indicator for metals,
  • asbestos* from the building materials,
  • metals from the battery make-up, including:
    • Aluminum
    • Cobalt
    • Copper
    • Lead
    • Lithium
    • Manganese
    • Nickel
  • hydrogen fluoride (byproduct of lithium-ion battery fires)
  • hydrogen cyanide (Hydrogen cyanide is a potential byproduct from plastic should it catch fire. This is a concern in the work zone but will also be measured at air monitoring stations and using a roaming air monitor if needed.)

*Note: When Vistra renovated the ML300 building, much of the asbestos was removed (this is called “asbestos abatement”) from the building. Only small amounts of asbestos in a limited number of materials were left on property.

Under our oversight, Vistra is taking measures to ensure any contamination on the property does not leave the site until the waste is properly managed for transport and disposal.

Air monitoring and sampling around the site and in the community since the fires confirms this.

Related Questions

  • Ongoing Work: Can the building be covered or tented?
  • Ongoing Work: How is the air monitoring and air sampling data being used to protect the community and the environment?
  • Ongoing Work: What will EPA and Vistra do if there are elevated readings detected by the air monitors?
  • Ongoing Work: How will you control dust and particles during operations?
  • Ongoing Work: How will you prevent the contamination from moving off site when it rains?

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Last updated on September 22, 2025
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