The fires in Los Angeles have created another problem – unsafe drinking water

Depressurization, the other big contributor to contamination, occurs when firefighting efforts pull massive amounts of water from the system in a short amount of time. “A water line that connects to a house can usually put about 9 gallons per minute,” says Whelton. “Firefighters can take 500 gallons or up to 1,500 gallons of water per minute. So if you were to launch five or six pumper trucks out of a water line, you’re looking at thousands of gallons of water that are extracted from the water system in a very short period.

When this happens, the water pressure drops, and the system becomes vulnerable to bacteria or chemicals entering the system from the surrounding environment. Usually, the high water pressure in the system prevents any external contaminants – such as soil or ground water – from being able to find their way into the system components.

Structural damage from fire can also result in pressure losses, Whelton says. In the case of a large-scale fire like the palisades or Eaton fire, you can have huge volumes of water dumping, uncontrolled, outside the system, due to pipes and other parts of the system being ruptured. Where there is damage, smoke and debris can be sucked into the water system, while damaged sewer lines can leak into drinking water pipes that run nearby. “When the water system utilities start trying to repress, they start pushing contaminated water through the infrastructure again,” says Whelton.

During the Marshall Fire in Louisville, Colorado in 2021, which burned more than 1,000 homes, city officials advised residents to use tap water only for washing until extensive testing confirmed its safety . Since more than 12,000 structures have burned in Los Angeles since Monday morning, the potential for widespread contamination is significant, Kearns warned.

The next few days and weeks will be crucial. Once water experts assess the damage, they will determine if the system can be flushed clean or if infrastructure repairs are needed. If it’s burned enough, workers have to replace pumps, pipes and even tanks. For parts of Los Angeles County served by LADWP, McCurry estimates that this recovery could take anywhere from a few days to weeks.

Altadena and the surrounding regions, however, are served by several smaller water suppliers, such as the Lincoln Avenue Water Company, Las Flores Water Company, Association Rubio Canon Land and Waterand Kinneloa Irrigation District– all who have issued Do Not Drink notices. “In the case of a large water system like LADWP, you’re probably going to see things pick up a little faster,” Kearns says. “For smaller water providers, who sometimes may only have a couple of employees and don’t have the budget for these types of events, they can have some struggles.” Santa Cruz experienced similar challenges during the CZU Lightning Complex Fire in 2020, with water service taking months to stabilize. McCurry warns that some regions may need years to build from scratch or overhaul large systems that have burned down.

It’s vital for residents to stay informed about recovery efforts, because alert systems can be complicated, and many residents don’t even receive them, Kearns says. People should “proactively look for any boil water or Do Not Drink notices from your water supplier, your city, your county,” he advises. “Share those with your neighbors and make sure people who may have languages ​​other than English as a first language get these alerts and understand what’s going on.”

Some places, such as Louisville in Colorado, and Maui in Hawaii, released public access maps that tracked the water quality at each site, which helped keep residents informed during the months and years that followed.

Before lifting the advisory, water suppliers are legally required by the State of California to monitor for benzene. However, Whelton warns that benzene is not the only chemical of concern and the list of potential contaminants is long. Government and third-party testing services do not always account for every possible exposure. “It is possible that some of these chemicals may persist beyond the perspective of water suppliers,” McCurry says. He always recommends staying vigilant. Activated carbon filters can help remove some organic pollutants, but they cannot completely eliminate the risks.

“Safe water can be restored after a fire,” says Whelton. “The communities that recover the fastest and strongest are the ones that work together and support each other.”