Federal contractors tasked with clearing ash and debris from the Eaton and Palisades wildfires improperly sent truckloads of asbestos-tainted waste to nonhazardous landfills, including one where workers were not wearing respiratory protection, according to state and local records.

From Feb. 28 to March 24, federal cleanup crews gathered up wreckage from six burned-down homes as part of the wildfire recovery efforts led by the U.S. Army Corps of Engineers and its primary contractor Environmental Chemical Corp.

However, prior to reviewing mandated tests for asbestos, crews loaded the fire debris onto dump trucks bound for Simi Valley Landfill and Recycling Center, and possibly Calabasas Landfill in unincorporated Agoura and Sunshine Canyon Landfill in Los Angeles’ Sylmar neighborhood, according to reports by the California Office of Emergency Services and Ventura County.

Later on, federal contractors learned those tests determined that the fire debris from these homes contained asbestos, a fire-resistant building material made up of durable thread-like fibers that can cause serious lung damage if inhaled.

The incident wasn’t reported to landfill operators or environmental regulators until weeks later in mid-April.

Many Southern California residents and environmental groups had already objected to sending wildfire ash and debris to local landfills that were not designed to handle high levels of contaminants and potentially hazardous waste that are often commingled in wildfire debris. They feared toxic substances — including lead and asbestos — could pose a risk to municipal landfill workers and might even drift into nearby communities as airborne dust.

The botched asbestos disposal amplifies those concerns and illustrates that in some cases federal contractors are failing to adhere to hazardous waste protocols.

“You have to wonder if they caught it here, how many times didn’t they catch it?” asked Jane Williams, executive director of the nonprofit California Communities Against Toxics. “It’s the continued failure to effectively protect the public from the ash. This is further evidence of that failure. This is us deciding those who work and live around these landfills are expendable.”

As of May 1, nearly 1 million tons of disaster debris has been taken to four landfills in Southern California. Simi Valley, an 887-acre landfill in Ventura County, has taken two-thirds of the tonnage. Several residents who live nearby voiced their disappointment ahead of the June 24 Ventura County Board of Supervisors vote to approve emergency waivers to allow fire debris to continue to be disposed of at Simi Valley Landfill — without a cap on tonnage — until Sept. 3.

“When I told my kids about the fire debris being dumped at the landfill, they asked me, why would anyone allow us to be exposed to this?” said Nicole Luekenga, a resident of nearby Moorpark, at the June 24 board meeting. “We are deeply concerned about the potential health risks from the fire debris being dumped at a residential landfill in our community. It feels as though profit and convenience are being prioritized over public safety, and that is unacceptable.”

An Environmental Chemical Corp. official acknowledged the lapse in asbestos protocols led to the improper disposal in February and March. He said the ash and debris from the six homes — four in Altadena, one in Pacific Palisades and one in Malibu — contained “trace amounts” of asbestos but did not elaborate on the specific type of building material that contained asbestos, or why the debris wasn’t flagged.

Asbestos has historically been used in a variety of construction materials — large and small — including roofing shingles, cement pipes, popcorn ceilings and insulation.

The company official said the improper disposal may have been due to a failure of either its workers or subcontractors to properly review paperwork. He also said he was unaware of any other cases in which asbestos or hazardous waste were improperly disposed. The Army Corps of Engineers declined to comment on the matter.

Environmental Chemical officials told Simi Valley Landfill that the asbestos should be presumed to be friable, a form of the fibrous mineral that is more easily broken down into smaller pieces and considered hazardous waste, according to an April letter from the landfill’s owner, Waste Management, to the Los Angeles Regional Water Quality Control Board.

During the time the asbestos waste was taken to the landfills, workers handling fire debris at Simi Valley Landfill had not been wearing protective masks or respirators, according to inspection reports. Typically municipal landfill workers don’t wear face coverings because they are mostly handling trash and nonhazardous waste.

But experts say protective masks are essential for protecting worker health at landfills. Landfill workers or hired contractors regularly drill pipelines extending hundreds of feet underground into the layers of the waste to extract gases that can build up when garbage decomposes. Experts say drilling into hazardous waste, such as asbestos waste, could expose workers to harmful substances if they aren’t wearing appropriate protective equipment.

During at least one visit in March, a Ventura County inspector found workers without masks in parts of the landfill designated for fire debris. Waste Management staff told the county inspector that mask-wearing was voluntary for employees. In April, county inspectors observed at least four workers constructing a new well in the fire debris area without respiratory protection, and another worker with only a cloth face mask.

High-filtration respirators are typically considered the best form of protection against asbestos. Protective masks, such as N95 masks, can guard against breathing in small particles, but should not be used to protect against asbestos.

Since learning about the asbestos-containing fire debris, local regulators have ordered the operators of Simi Valley Landfill to consult with safety professionals to determine the appropriate level of protective gear needed to protect against breathing in hazardous contaminants.

Army Corps officials had previously vowed that contractors would test for asbestos and take steps to segregate this waste and to take it to the appropriate disposal locations, such as Azusa Land Reclamation Co., a 300-acre landfill in the San Gabriel Valley that is also owned by Waste Management.

Waste Management officials said the company intends to leave the asbestos-containing waste in place, because attempting to excavate it could increase the likelihood that some of the toxic material would be released into the air. Nicole Stetson, district manager at Waste Management, urged the Los Angeles Regional Water Quality Board to ask Environmental Chemical what actions it would take to prevent more asbestos from inadvertently being dumped there.

The landfill staff “followed all relevant procedures during affected period and could not have prevented these events through any reasonable means,” Stetson wrote in a letter in April.

So far, regulators have been mum on whether any enforcement action has been taken after the lapse in hazardous waste protocols. The regional water board declined to comment. CalRecycle referred questions to local authorities that it partners with to provide oversight and ensure compliance.

The Army Corps of Engineers is more than halfway through its mission of clearing the wildfire debris from the vast majority of homes and schools that were razed in the Eaton and Palisades wildfires. So far, it has overseen the removal of fire debris from nearly 9,000 properties.

The wildfire ash and debris the Army Corps has moved from disaster sites to landfills probably contains elevated levels of toxic metals. For example, Nick Spada, a researcher with the UC Davis Air Quality Research Center, has collected dozens of ash samples from the burn scars and, in preliminary findings, found elevated levels of lead, arsenic, cadmium and antimony in the test materials.

Spada is sampling the air near Simi Valley Landfill in hopes of identifying the levels of dust pollution from the site. The air sampling will help determine the types of metals in the air along with the particle sizes. (Smaller particles can cause more health complications because after they are inhaled into lungs, some are tiny enough to enter the bloodstream.)

Spada said the forthcoming results should provide communities with important greater insight into public health risks associated with the wildfire debris that continues to be dumped there. But, beyond the community, Spada is also concerned with those who are the closest to the debris: the workers.

“I see our role as raising concerns and then exploring them and trying to help out our friends in the regulatory agencies and the government that are all working as hard as they can trying to get a handle on this massive tragedy,” he said. “I’m concerned about all the workers who are in the burn areas, who are doing this work without respirators. It’s really hot, so heat-related illnesses is a primary concern, as is respiration of these particles.”