Researchers call for more comprehensive soil testing after LA fires. But who should do it?

A group of environmental researchers is calling for more comprehensive soil testing in the L.A. region after January’s fires. In a letter sent to Gov. Gavin Newsom last week, a dozen experts said the state should pay for widespread testing to ensure lots are safe to rebuild on.

The federal government has been in charge of cleaning up after the Eaton and Palisades fires, but have said they will not test soil for heavy metals and other toxins once lots are cleared.

The U.S. Army Corps of Engineers, which has lead debris removal after the U.S. Environmental Protection Agency cleared hazardous debris first, has said clearing 6 inches of topsoil should be enough to eliminate the most harmful levels of toxins. But independent testing by researchers and L.A. County has found high levels of toxins such as lead in lots already cleared by the Army Corps.

“We've been really alarmed in some cases by the higher levels of lead that we are seeing, especially within the urban burn scar,” said Seth John, a USC earth sciences professor who signed on to the letter. His lab is leading independent soil testing research and free testing for residents.

“The variability in lead concentrations can be very high, even within a very small area,” John said.

The governor's office hasn't responded to the researchers’ letter, but did tell LAist that California "continues to push for our federal partners to conduct comprehensive soil sampling as part of the debris removal process."

Who’s in charge of soil testing?

In L.A., no one is taking charge of comprehensive soil testing.

Here’s how it’s worked in the past: The U.S. Army Corps of Engineers, through funding from FEMA has historically tested soil after clearing private properties destroyed by recent wildfires — they did so after the 2023 Maui fire that burned down Lahaina, as well as after the 2017 fires in Northern California.

As for other fires in between — including the Woolsey, Thomas, Tubbs and Camp fires, the last of which burned down the town of Paradise and remains California’s most destructive fire on record — the state has been in charge of clearing private property and paying for soil testing afterward. Those efforts were led by California’s Office of Emergency Services and carried out by the California Environmental Protection Agency and CalRecycle (the state agency for waste management, which has a disaster debris cleanup program).

FEMA changed its position on soil testing in 2020, according to a letter from the agency in response to Newsom’s recent request asking that they pay for comprehensive soil testing in the Eaton and Palisades burn zones.

“FEMA ... has consistently determined in California that removing the top 3-6 inches of soil beneath fire debris is sufficient to address fire-related contamination and protect public health,” Curtis Brown, a federal coordinating officer with FEMA, wrote in the letter.

Brown wrote that until 2018, the agency’s policy was to initially remove three inches of soil, then test it before removing another three inches of soil and testing it again.

“This practice was tedious, inefficient, and a barrier to timely clean up and recovery,” Brown wrote. “Furthermore, such testing efforts across various wildfire events in California showed that any positive results from testing were primarily due to contaminants in the soil pre-fire, not due to the declared fires themselves. Because of this, FEMA’s position since 2020 has been to fund the removal of the full 6 inches of soil right away but not fund any further testing.” (The agency made an exception, which Hawaii requested, for the 2023 Maui fire because of a lack of historical soil data.)

State pushes feds for more testing

The state requested the federal government lead cleanup in the case of the Eaton and Palisades fires “due to the size, complexity and resources needed. This includes testing and appropriate remediation,” a spokesperson for CalEPA wrote in an emailed statement to LAist.

In February, California formally requested that FEMA conduct comprehensive soil sampling at affected properties as part of the debris removal process. FEMA denied the request in under 24 hours.

Eight California members of Congress have called on FEMA to reverse its refusal to conduct soil testing after wildfires.

How concerned should you be about the soil?

John, the USC professor, said determining how much lead or other toxins were in the soil before the fire is difficult.

“ We know that lead concentrations are high all over Los Angeles and have been high in Los Angeles long before these fires ... just [from] the decades of burning leaded fuel and gasolines,” John said.

FEMA may be right, he added, that it may not be possible “ or it may be very, very difficult to get lead concentrations down below that target threshold.”

Beyond lead, he and the other researchers say a comprehensive test for toxic substances, including asbestos and lithium, is important before rebuilding. But the level of concern will depend on where the substances are and how much is present.

For lead, for example, California’s state standards for residential properties say levels should not exceed 80 parts per million. The federal EPA’s standard is 200 parts per million.

“I think it's important not to take any of these numbers as a hard line between safety and danger,” John said.

While no amount of lead is considered safe, we live in an environment with a certain level of toxicity, John said. But the higher the lead levels are, the more you want to reduce exposure. And that will depend on where exactly that concentration is on the property.

“So if you have very high lead concentrations, but it's going under the foundation of a house where you won't be exposed to it, it's really not something for concern,” John said. “If you have a more moderate amount of lead contamination, but it's in an area where your children or your pets are playing in the soils, then that would be something that you might really want to think about remediation. So you both have to consider the amount of lead in these various soils and how likely you and those you love are to be exposed to those soils.”

How to get your soil tested

• L.A. County's free soil testing program for properties downwind of the Eaton Fire.
• Free soil testing via USC in Eaton and Palisades burn zones.
• Find the latest data on soil testing — and other environmental testing after January’s fires — here.