Depressurization, another major source of contamination, occurs when firefighting efforts draw large amounts of water from the system over a short period of time. “Water pipes leading into your home typically produce about 9 gallons of water per minute,” says Welton. “Firefighters can pump 500 gallons of water per minute, up to 1,500 gallons, so if you run five or six pumpers from a water line, you can pump thousands of gallons of water in a very short period of time. It will be extracted from the water system.”
When this happens, water pressure drops rapidly and the system becomes vulnerable to bacteria and chemicals entering the system from the surrounding environment. The high pressure of the water in the system typically prevents external contaminants, such as soil or groundwater, from entering the system’s components.
Structural damage from a fire can also cause pressure loss, Welton says. In large fires like the Palisades and Eaton fires, large amounts of water can be released uncontrollably out of the system as pipes and other parts of the system burst. If there is damage, smoke and debris can be sucked into the water system, and damaged sewer pipes can leak into nearby drinking water pipes. “When water utilities start trying to repressurize, they start pumping contaminated water back into the infrastructure,” Welton said.
In the 2021 Marshall Fire in Louisville, Colorado, which destroyed more than 1,000 homes, city officials advised residents to use tap water only for flushing until extensive testing proves it safe. A recommendation was made to residents. Given that more than 12,000 structures were burning in Los Angeles as of Monday morning, the potential for widespread contamination is significant, Kearns warned.
The next few days and weeks will be crucial. Once a water professional has assessed the damage, they will determine if the system can be flushed out and cleaned, or if infrastructure repairs are needed. If it burns enough, workers will have to replace the pump, pipes, and even the tank. In parts of Los Angeles County served by LADWP, McCurry estimates that recovery could take days or weeks.
However, Altadena and the surrounding areas are served by several smaller water utilities, including: Lincoln Avenue Water Company, Las Flores Water Company, Rubio Cannon Land and Water Associationand Kineloa Irrigation District— all of which have issued no-drink notices. “For large water systems like LADWP, things will probably reopen a little sooner,” Kearns said. “Small water utilities may struggle with only a few employees and may not have the budget to host this type of event.” In Santa Cruz, the 2020 CZU A similar challenge occurred during the lightning facility fire, and it took several months for water service to stabilize. McCurry warned that in some areas it could take years to build from scratch or overhaul large systems that have broken down.
Kearns said it’s important for residents to stay informed about recovery efforts because alert systems can be complex and many residents may not have received alerts. People should “actively look for warnings from their water provider, city, or county that they should not boil or drink the water,” she advises. “Please share this information with your neighbors and help alert those whose first language may not be English so they understand what is happening.”
Some places, such as Louisville, Colorado, and Maui, Hawaii, published public access maps that track water quality on each parcel of land, helping to keep residents informed in the months and years that followed. .
Water utilities are legally required by California to monitor benzene before lifting advisories. But Welton warns that benzene is not the only chemical of concern, and there is a long list of potential contaminants. Both government and third-party testing services do not always account for all possible exposures. “Some of these chemicals may linger longer than the water provider expects,” McCurry agrees. He still advises continued vigilance. Activated carbon filters can help remove some organic contaminants, but they do not completely eliminate the risk.
“Safe water” can It can be repaired after a fire,” Welton said. “Communities that recover quickly and strongly are communities that work together and support each other.”
