The U.S. Environmental Protection Agency has reported that soil tests from properties affected by the Eaton Fire show most cleared lots do not contain hazardous levels of lead, though some experts question whether the sampling fully captures potential risks in the Altadena area.
The Eaton Fire, which tore through the Los Angeles-area community in January 2025, destroyed 9,400 homes and structures. Smoke from the blaze carried lead, arsenic and asbestos that settled on nearby land. Lead, a known neurotoxin, poses particular risks to children’s development. The Army Corps of Engineers handled debris removal on roughly two-thirds of the burned properties, scraping away ash and up to six inches of soil, but did not conduct soil tests before or after the work.
In response to concerns from residents and elected officials, the EPA tested soil at 100 randomly selected homes within the debris cleanup zone. Only five of those lots exceeded federal screening standards for lead, while 17 surpassed California’s stricter limits. The median lead concentration across the tested properties stood at 31 milligrams per kilogram in surface soil and 43 mg/kg at a depth of about six inches—both well below the EPA’s 200 mg/kg threshold and California’s 80 mg/kg guideline.
“That should really give residents confidence that the work that the Army Corps did addressed the fire-related contaminants, particularly lead,” said Michael Montgomery, director of the EPA Region 9 Superfund and Emergency Management Division. “The Army Corps did remove ash and debris and the soil beneath that ash and debris to an adequate level.”
Montgomery added that the agency can state with 95 percent confidence that addressed homes and burn areas in Altadena and Pasadena fall below both state and federal screening levels. The EPA selected properties where residents agreed to testing and access was possible, then collected soil from 30 locations within each property’s ash footprint at two depths before combining them into composite samples.
One surface sample reached 705 mg/kg, exceeding federal standards. The EPA has not previously conducted this type of post-wildfire soil testing, according to Montgomery, who noted that the Federal Emergency Management Agency requested the study to address local worries.
Andrew Whelton, a professor of civil, environmental and ecological engineering at Purdue University, expressed skepticism about the EPA’s approach. He argued that the results are not representative of the full Eaton Fire area and that the pooling method used can mask localized hot spots of contamination.
“The results they have are not representative of the Eaton Fire area,” Whelton said. “They were collected in a way that cannot be compared to existing data other organizations are collecting or to what Californians or California businesses have come to expect for property safety.”
Whelton pointed out that the testing focused only on areas the Army Corps chose to scrape, leaving other parts of properties unexamined. He also noted that hot spots have appeared after previous California wildfire cleanups when contractors left behind ash and debris.
“We know, based on prior experiences in California, that hot spots are real after debris removal — where contractors fail to remove ash and debris,” Whelton said. “Even individuals that pass this individual testing may have lead levels that exceed lead levels on parts of their property, but this testing wasn’t designed to figure that out.”
Two whistleblowers recently told NBC News that the cleanup process appeared rushed and inconsistent compared with earlier wildfire responses. One said workers left more debris behind than in past events, raising fears that residents could face ongoing contamination issues.
Altadena’s older housing stock, much of it built before lead was removed from paint and pipes, has added to residents’ concerns. Academic scientists, consultants for the Los Angeles County Department of Public Health and private groups have conducted their own soil tests, with scattered results that have sometimes heightened alarm.
The EPA’s findings apply specifically to the tested properties and are intended to offer a broad picture rather than pinpoint every possible contaminated spot. Officials have said the data should reassure most residents whose lots were cleared by the Army Corps.
Questions remain about properties outside the sampled areas and about long-term monitoring. Local health officials and independent researchers continue to gather additional data as cleanup and rebuilding efforts move forward in the region.