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

Moss Landing Soil: Did EPA use X-ray fluorescence (XRF) to test soil on and around the site?

Return to: Frequently Asked Questions

Monterey County is overseeing the soil sampling in the community to assess exposure, while EPA remains focused on overseeing the battery removal work at the site.

X-ray fluorescence (XRF) is a screening tool used to detect metals in soil. Screening tools are helpful to assess where additional sampling may be needed.

  • Results can help assess potential contamination levels but require soil sampling and laboratory analysis for confirmation.

Soil Sample Accuracy for Community Sampling

As part of Monterey County’s community soil sampling effort, Vistra sampled soil around the Moss Landing community. The samples were collected to support a human health risk assessment. Monterey County collected “split samples” with Vistra. This means the county took samples from the same locations and times as Vistra.

  • These samples are sent to different, independent labs.
  • The results are compared to each other for quality control.

Find more information about community sampling efforts on Monterey County’s Moss Landing website.

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Last updated on September 22, 2025
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