Like burning stay lit by Los Angeles, various utilities have declared their drinking water unsafe until extensive testing can prove otherwise.
A warmer, drier climate means wildfires are getting worse and encroaching on cities – with devastating consequences. Toxic chemicals from these burns can leach into damaged drinking water systems, and even filtering or boiling won’t help, experts say.
Last week, for the first time since the company began distributing water more than a century ago, Pasadena Water and Power issued a “Do Not Drink” notice to about a third of its customers. With at least one burned pump, several damaged storage tanks and burned homes, they knew there was a chance that toxic chemicals had entered their pipes.
“Out of an abundance of caution, you really have to assume the worst,” said Stacie Takeguchi, the utility’s chief assistant general manager.
This week she has withdrawn the notification for most of the area after testing.
When large fires rage in towns and cities, rather than in forests and grasslands, infrastructure can be severely damaged. When drinking water systems are damaged by a fire, “ash, smoke, soot, other debris and gases can be drawn into the water supply network,” said Andrew Whelton, an engineering professor at Purdue University who researches water pollution in affected communities. by water. firework.
These elements can be particularly toxic because chemically manufactured synthetics in building materials and households heat, burn and release particles and gases, he said. Some of these chemicals are harmful even at low concentrations, experts say.
Drinking water systems are designed to be airtight to keep harmful elements out. But that critical pressure can be lost in many ways during a fire, allowing toxins to enter.
There is normal demand for the water system from people who did not have to evacuate. Firefighters use a lot of water. Pipes in burned buildings can become damaged, causing the release of water.
Loss of power can also cause loss of pressure pumps no longer worksays Greg Pierce, professor of urban environmental policy at the University of California. This happened during the 2023 Maui fires.
“It’s really difficult, if not impossible, to maintain power to the entire water system in the event of a fire, because you either shut off the power, because the power could contribute to the fire, or the power just goes out. ,” said Pierce. “And then at best you rely on generators.”
The pressure loss can affect not only water quality, but also the availability of water for firefighting. Hydrants were dry in the Pacific Palisades neighborhood as surrounding homes burned. The utility says it was due to high demand and the pumps workedbut California Governor Gavin Newsom said the state will investigate.
Toxic chemicals in drinking water after a fire pose risks ranging from temporary nausea to cancer, experts say.
“In Paradise (California), benzene levels were high enough to acutely give a child a blood disorder,” said Dr. Lynn Goldman, dean of the Milken Institute School of Public Health at George Washington University, referring to the 2018 Camp Fire that burned most of the city.
Even very low levels of some chemicals can be a problem. In California, say state regulators only one part per billion of benzene – a known carcinogen – is considered a safe level in drinking water, calculated over 70 years of exposure. The national recommendation is not more than five parts per billion.
“In terms of cancer risk, we’re really interested in the cumulative amount that you’re exposed to over your lifetime,” Goldman says. “And if a short-term exposure adds a lot to that, that is a real risk.”
Benzene and similar compounds are known to be volatile because they tend to become airborne, like gasoline turning to vapor as it drips from the pump onto your car. A group of heavier compounds, called semi-volatile, were found in water pipes in Louisville, Colorado after the 2021 Marshall Fire, even when benzene and other better known chemicals were not. Whelton says it’s critical testing for both.
Vast Los Angeles County has more than 200 water suppliers, but only so far a handful believe that damage or loss of pressure may have resulted in chemical contamination and have issued warnings stating that you should not drink. Utilities are focused on ensuring there is enough water to fight fires, although some are beginning to test for contaminants. It can take weeks to months before the water can be declared safe to drink in areas with minimal damage.
That’s sometimes the best case scenario.
During the Paradise Fire, most buildings burned. The city has rebuilt a reservoir and is working to replace 10,000 service lines. It expects to spend $50 million over the next decade to replace about 17 of the 170 miles of contaminated trunk lines.
Whelton does not recommend that people pay for expensive water testing in their homes until their utility company has declared the public water system safe.
Many publicly available water quality tests are “unable to find fire-related drinking water contamination,” Whelton wrote on X this week. Having your water professionally tested once the water has been declared safe by the utility would be the best way to find out if your pipes are contaminated, he said.
People should follow their utility company’s or local health department’s guidelines on safety measures until their water is declared safe.
__
The Associated Press receives support from the Walton Family Foundation for reporting on water and environmental policy. The AP is solely responsible for all content. For all AP environmental reporting, visit https://apnews.com/hub/climate-and-environment