ALTADENA — The U.S. Environmental Protection Agency reported that soil testing at 100 homes in the Altadena area destroyed by the January 2025 Eaton Fire found median lead levels below state and federal levels of concern. Only five lots exceeded EPA screening standards for lead, while 17 lots exceeded California's stricter screening standards.

The testing covered about 1% of the 9,400 homes and structures destroyed by the Eaton Fire, which sent smoke containing lead, arsenic and asbestos into the air to settle in surrounding areas. Lead is a potent neurotoxin associated with developmental problems in children.

The Federal Emergency Management Agency asked the EPA to conduct the testing to address concerns voiced by elected officials and residents. The agency had not performed this kind of testing after past wildfires.

The EPA randomly selected properties from the debris cleanup zone and then sampled sites where residents agreed to testing and where access was feasible. At each property, soil was collected at two different depths from 30 locations within the "ash footprint" and then pooled to produce two composite samples per property — one at the surface and another about 6 inches below.

The median concentration of lead in surface soil was 31 milligrams per kilogram, and the median in subsurface soil was 43 milligrams per kilogram. California's level of concern for lead in soil is 80 milligrams per kilogram, and the EPA's screening level is 200 milligrams per kilogram. Five surface composite samples tested above federal screening standards, including one that measured 705 milligrams per kilogram.

"We can say with 95% confidence that the homes that were addressed, or that burn areas that were addressed in Altadena and Pasadena, were below both the California and the federal screening level," said Michael Montgomery, director of the EPA Region 9 Superfund and Emergency Management Division. "That should really give residents confidence that the work that the Army Corps did addressed the fire-related contaminants, particularly lead."

The Army Corps began debris removal in 2025 and cleared ash, debris and underlying soil on about two-thirds of the homes that burned down. Soil testing before and after the cleanup was not a requirement, and the Army Corps did not perform it. According to Montgomery, the Army Corps "did remove ash and debris and the soil beneath that ash and debris to an adequate level."

Academic scientists, consultants for the Los Angeles County Department of Public Health and private groups have also been testing soil in the area. Andrew Whelton, a professor of civil, environmental and ecological engineering at Purdue University in Indiana, questioned the EPA's approach.

"The results they have are not representative of the Eaton Fire area. 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 said. "We know, based on prior experiences in California, that hot spots are real after debris removal — where contractors fail to remove ash and debris."