January 14, 2025
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Wildfires may contaminate Los Angeles water with harmful chemicals
Fires can make drinking water, pipes and tanks dangerous. An environmental engineer explains why this is and what to do about it

Water flows through a pipe that was destroyed by the Palisades Fire on January 8, 2025, in the Pacific Palisades community of Los Angeles, California, where a home once stood.
Jay L. Clendenin/Getty Images
The following text is reprinted with the user’s permission The conversationan online publication featuring the latest research.
The fires around Los Angeles have destroyed it thousands of structuresmany of them homes, and firefighters continue to battle the inferno. Parts of Pacific Palisades, Altadena, Pasadena and other California communities are now unrecognizable.
As evacuation orders are lifted, drinking water should be kept in mind for residents who are able to return to their homes.
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What many people don’t know is how much fire can damage a community’s drinking water system, how it affects the water, and what they can do about it.
as an environmental engineerI work with communities affected by wildfires and other disasters. Over the years, my team and I have been called to help after some of the most devastating wildfires in US history. In some cases, we have advised far-flung state and local officials.
Various local water Systems in the Los Angeles area have started giving warnings about not to use has potentially unsafe drinking water. Here’s what residents in the area and anyone living near where a fire breaks out need to know.
How fires can make water dangerous
Fires can produce drinking water, and water pipes and tanks themselves, safe. This happens for several reasons.
One reason is when heavy use of firefighting water drains the water system.
Water systems are not designed to fight forest fires. They also require damaged and destroyed structures without control water leaks The powerthe loss it also prevents water drainage systems from filling up quickly enough. Combined, these factors can depressurize the water system, making water unavailable.
When there is water sold outthe system is vulnerable to chemical contamination.
Contamination of drinking water may also occur from the air and due to damage to the infrastructure of the water system. Heat can partially melt plastic pipes and water meters, releasing chemicals; smoke can be drawn into water systems; and disruptions in water infrastructure can cause pollution.
Many cancer-causing chemicals have been found in damaged water systems after wildfires. Sometimes these chemicals, such as benzeneIf someone drinks or uses the water, someone can get sick immediately. Symptoms can include nausea, headache and rashes.
These chemicals stick to infrastructure surfaces and can also penetrate some plastic pipes and joints. Removing them can take days or months. Some plastics can absorb chemicals like a sponge and slowly release them into clean drinking water, making that water unsafe for a long time.
How communities can reduce risk
Residents and businesses drinking water suppliers and health officials should pay attention to water safety announcements.
Safety can be determined by appropriate chemical testing. Fortunately, the former guide to water systems fire response and recovery was published in 2024. Property owners can find more information From groups like our research group at Purdue University.
When to test and treat your water
Care must be taken when testing domestic drinking water.
After the fires of 2023 Maui, Hawaiiand in the 2018 Camp Paradise, CaliforniaI met with many households who spent hundreds or thousands of dollars to hire companies to do their water testing. However, many of the results were nonsignificant. In some cases:
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Residents were charged for water analysis, even though their samples were mishandled.
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Potentially contaminated water was flushed from the plumbing before a sample was collected.
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The water samples were not screen for direct fire-related chemicals.
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Samples were not collected from the right places or from enough places in the house.
Treatment of water is not recommended until contamination levels are known. Nearby water systems they have given such warnings.
Residents should also be aware that household water treatment devices are not guaranteed making highly polluted water safe.
To help properties make the best decisions, water utilities need to quickly test and share with the public what chemicals are in their water systems. Once testing is done and the risks are known, homeowners may want to do their own testing if plumbing is damaged or contaminated water has entered.
Water systems can be restored
It can be frustrating to wait for information, but immediately after fires it is not safe for water officials to enter affected areas to begin testing.
History has shown that safe water can be restored. Support from experts who have helped others respond can speed recovery. In my experience, communities that recover faster and stronger are those that work together and support each other.
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