Concerned about fire contaminants in your soil? A new expert guide can help

A new guide from a group of local scientists helps Angelenos affected by the 2025 L.A. fires navigate questions about soil testing and clean up.

The guidelines are based on soil tests conducted by USC CLEAN and Community Action Project Los Angeles on more than 6,000 lots in and around burn zones in the Pacific Palisades and Altadena.

Sujeet Rao, the health and well-being practice director at Public Exchange at USC, who contributed to the guide, said it's a response to questions that he and other contributors knew residents had.

“We all came together … to help fire affected families understand and navigate questions they may have about environmental contamination related to the fires,” Rao said.

The guide includes information about soil contamination, testing, cleanup methods and ways to reduce your exposure risk.

The dangers of soil contamination

When the Eaton and Palisades fires burned down houses and garages, items including paint, kitchen appliances and car batteries released dangerous substances into the environment.

Exposure to these substances can increase the risk of respiratory, neurological and reproductive problems, as well as certain cancers.

Lead was the most common concern, according to the scientists’ testing.

Rao said that’s worrying because lead is a neurotoxin.

“What that means is that [for] especially young children whose brains are still developing or women who are pregnant, lead can affect the development of the brain,” Rao said.

Should you test your soil? 

Rao said it’s hard to say whether any specific property needs soil testing or cleanup, but gave some general guidelines.

If your house burned, definitely.

If you saw ash in the air, on the ground or otherwise near your house during the fires, get your soil tested.

If not, testing is likely unnecessary.

Other things to consider are the age of the houses that burned and their proximity to your property.

“We do know that if you’re in a neighborhood that has a lot of old housing, it is more likely that there is lead that could have been mobilized,” Rao said. “The inverse of that is, in the Palisades, we generally see much lower levels of lead contamination because the housing there tends to be so much newer.”

What to know about soil testing

The guide suggests two main options for going about testing.

One option is to hire specialists to come to your house to collect and test samples.

The other option is collect samples yourself and submit them to a testing program, such as USC CLEAN.

In the testing results, look for contaminant levels that exceed the residential limits set by the Environmental Protection Agency or the California Department of Toxic Substances Control.

Both account for how the area is used, including whether children are playing outside or people are gardening.

Cleanup methods

If your soil test results are above the EPA or DTSC limits, the guide offers four main methods to clean it up.

1. Excavation: Removing the soil, throwing it out at a disposal facility and replacing it with clean soil.
2. Capping: Putting clean soil, gravel or another physical barrier between the contaminated soil and the people and animals who may come into contact with it.
3. Immobilization: Adding compost, phosphorus or other materials to stop the spread of contaminants.
4. Bioremediation: Putting plants, bacteria or fungi into the affected soil to break down biodegradable contaminants.

Some soil remediation can be paid for through insurance. Costs will depend on the size of your yard and which contaminants are present. The guide estimates that the least costly options are capping and immobilization, which can run around $10,000.

The full soil remediation guide is on the Consortium website.