As LA wildfires rage on, high winds are expected to worsen conditions, amplifying the destruction and raising new concerns about drinking water safety. Last week, Pasadena Water and Power issued its first-ever “Do Not Drink” notice to a third of its customers, citing the risk of toxic chemicals infiltrating the water supply after infrastructure damage. Although the advisory has since been lifted for most areas, the incident highlights the hidden dangers urban fires pose to water systems.
Unlike wildfires in forests, urban fires wreak havoc on critical infrastructure. Andrew Whelton, a Purdue University professor, explains that ash, soot, and debris can enter water systems when pressure drops during a fire. Compounds released from burning synthetic materials are especially harmful, even in trace amounts, potentially causing health risks from nausea to cancer.
Water systems rely on steady internal pressure to block contaminants. Fires disrupt this balance through high water demand from firefighting, damaged pipes, and power outages that disable pumps. This pressure loss, observed during the 2023 Maui fires, not only risks contamination but also hampers firefighting efforts.
Exposure to fire-related toxins like benzene a carcinogen can lead to serious health issues. For instance, benzene levels detected during California’s 2018 Camp Fire posed acute risks to children. Experts warn even minimal exposure can increase lifetime cancer risks.
Utilities across Los Angeles are testing for contaminants while ensuring adequate water for firefighting. However, recovery is slow, as seen in Paradise, California, where rebuilding water infrastructure after the 2018 fire will take a decade and cost $50 million.
Residents are advised to wait for utilities to declare water systems safe before considering professional home water testing, as standard tests may not detect fire-related contaminants.
As high winds threaten to intensify the fires, the focus remains on safeguarding both lives and resources. The ongoing crisis underscores the urgent need for resilient infrastructure and robust safety measures to combat the compounded threats of wildfires and water contamination.