When the flames in Los Angeles County are finally extinguished, the region will face the costly, time-consuming and heart-wrenching task of hauling away tons of toxic rubble. Given the scale of devastation in and around America’s second-largest city, that cleanup could become one of the country’s most complex debris removal efforts ever.

In each of the thousands of ash piles where homes once stood, there are remnants of lives upended. But the photo albums, football cards and family heirlooms are intermixed with a noxious cocktail of asbestos, gasoline and lead, a reality that will make cleanup extremely complicated.

“We kind of treat each of these properties as its own hazardous waste cleanup site,” said Cory Koger, a debris expert with the Army Corps of Engineers who has responded to several major wildfires, including the fire that destroyed much of Lahaina, Hawaii, in 2023.

“Recovery planning really begins as soon as the fire starts,” said Jenn Hogan, the deputy director for disaster debris recovery operations at CalRecycle, a state agency that focuses on waste management and climate. “Once the fire is contained, you’ll start seeing a lot of those recovery resources hit the ground.”

Mark Pestrella, the Los Angeles County public works director, described a “tremendous amount of debris” that had already made its way into local reservoirs and filtration systems, hurting water quality. He said the debris was being moved in some cases to help firefighters maneuver through hard-hit areas, but stressed that the most significant handling and removal of the detritus would take time.

Unlike in some rural areas or mountain towns hit by fires, which might be hard to access with heavy machinery, recovery crews in Los Angeles will have the advantage of robust road infrastructure and a large local workforce. But experts said they anticipated challenges in finding landfills to take the huge quantities of toxic material.

“If it takes two hours to dump a load, I mean, do the math on 1,000 properties,” said Alyssa Carrier, the founder and CEO of AC Disaster Consulting, a private emergency management company that has worked on wildfire responses in Colorado, Florida and Oregon. “One house could be 15 loads,” she added, “so that’s going to be one of the biggest challenges.”

Cleanup generally occurs in distinct phases over several months. After an initial assessment of damage, workers wearing full hazardous material gear remove dangerous items in clear view. Later, crews return to haul away ash, burned trees and other remaining debris. Before rebuilding begins, officials test the soil to ensure that no toxins remain from the fire.

The cleanup process also is filled with dangers. Bryan Schenone, the director of the emergency services office in Siskiyou County, Calif., a rural area that has seen a series of devastating fires, including the Mill fire in 2022, said common household items become an environmental threat when they burn. Propane tanks or loose ammunition can explode and present a safety risk.

“Imagine what’s in your garage: all the paint, all the chemicals underneath your sink,” Schenone said. “That leaches into the ground, and that all has to be cleaned up and becomes a toxic footprint.”

Another challenge, experts said, is securing landowner permission, parcel by parcel, for workers to enter the property and begin the cleanup. There can also be delays as officials line up work crews and dump sites, or when nesting season for birds requires work to be paused on certain properties. It can be painful, officials said, to tell residents that they should not return to search for mementos in the rubble.

As destructive wildfires become more common because of climate change, a muscle memory has developed among the government officials and private contractors who respond to calamity after calamity.

Each of those disasters has its own complexities, but many of the processes and lessons are the same. And no state has as much practical expertise in responding to wildfires as California, which even publishes a handbook on how to make fire-scarred parcels safe to inhabit again.