Depressurization, the other major contributor to contamination, occurs when firefighting efforts extract enormous amounts of water from the system over a short period of time. “A water line connected to a house can typically produce about 9 gallons per minute,” says Whelton. “Firefighters can draw 500 gallons or up to 1,500 gallons of water per minute. So if you were to run five or six pump trucks from one water line, you get thousands of gallons of water pulled out of the water system in a very short period of time.
When this happens, water pressure drops and the system becomes vulnerable to bacteria or chemicals entering the system from the environment. Usually, the high water pressure inside the system prevents any outside contaminants, such as soil or groundwater, from making their way inside the system components.
Structural damage from fires can also lead to pressure losses, Whelton says. In large-scale fires like the Palisades or Eaton fires, huge volumes of water can spill uncontrolled out of the system due to ruptured pipes and other parts. of the system. If damaged, smoke and debris can be drawn into the water system, while damaged sewer lines can leak into nearby drinking water lines. “When the water system utility starts trying to repressurize, it starts pushing that contaminated water through the infrastructure again,” Whelton says.
During the 2021 Marshall Fire in Louisville, Colorado, which burned more than 1,000 homes, city officials advised residents to use mains water only for flushing toilets until Extensive testing confirms safety. Given that more than 12,000 structures burned in Los Angeles as of Monday morning, the potential for widespread contamination is significant, Kearns warns.
The coming days and weeks will be crucial. Once water experts assess the damage, they will determine if the system can be flushed or if infrastructure repairs are necessary. If enough fuel has burned, workers will need to replace pumps, pipes and even tanks. For the parts of Los Angeles County served by LADWP, McCurry estimates this recovery could take anywhere from a few days to a few weeks.
Altadena and surrounding areas are, however, served by several small water suppliers, such as Lincoln Avenue Water Company, Las Flores Water Company, Canon Rubio Land and Water AssociationAnd Kinneloa Irrigation District– all of whom have issued advisories not to drink. “In the case of a large water system like LADWP, you’ll probably see things pick up a little quicker,” Kearns says. “For small water suppliers, who sometimes only have a few employees and do not have the necessary budgets for these kinds of events, they can have some difficulties. » Santa Cruz experienced similar challenges during the CZU Lightning Complex fire in 2020, with water service taking months to stabilize. McCurry warns that some areas could need several years to build from scratch or overhaul large systems that burned.
It’s critical that residents stay informed about recovery efforts, because alert systems can be complicated and many residents may not even receive them, Kearns says. People should “proactively look for any boil or do not drink water alerts with your water supplier, your city, your county,” she advises. “Share them with your neighbors and make sure everyone whose native language is a language other than English receives these alerts and understands what’s happening.”
Some places, such as Louisville, Colorado and Maui, Hawaii, have published public access maps to track water quality on each property, which has helped keep residents informed over the months and years that followed.
Before lifting advisories, water suppliers are legally required by the State of California to monitor for benzene. However, Whelton cautions that benzene is not the only chemical of concern and that the list of potential contaminants is long. Government and third-party testing services do not always account for all possible exposures. “It is possible that some of these chemicals will persist longer than water suppliers expect,” McCurry echoes. He still recommends remaining vigilant. Activated carbon filters can help remove some organic contaminants, but they may not completely eliminate the risks.
“Safe water can be restored after a fire,” says Whelton. “Communities that recover quickly and stronger are those that work together and support each other. »
