WILDFIRESA Lawsuit to Protect Streams Could Take Away an Important Firefighting Tool

By Max Graham

Published 16 May 2023

The U.S. Forest Service uses millions of gallons of fire retardant to fight wildfires. There have long been concerns about what happens when that mix of ammonium phosphate, emulsifiers, and colorants finds its way into water.

Every summer, wildland firefighters across the West gear up for a monumental task, aiming to stop fires that are burning hotter and moving faster with climate change. They accomplish this in two ways: on the ground and out of the sky. From above, helicopters sling buckets of water, while airplanes dump fire retardant — a thick red solution made mostly of fertilizer. The United States Forest Service uses millions of gallons of retardant each year. 

But there have long been concerns about what happens when that mix of ammonium phosphate, emulsifiers, and colorants finds its way into water. Some environmentalists worry spraying the stuff on forests does more harm than good. The main chemical in retardant — ammonium phosphate — is known to poison fish and other aquatic life, including vulnerable species like Chinook salmon. Some research suggests the slurry also could spur the growth of weeds that threaten native plants. Now, Forest Service Employees for Environmental Ethics — a nonprofit that represents current and former Forest Service employees — is suing the Forest Service over its use. They allege that the federal agency has been violating the Clean Water Act by dumping the flame-stopping chemicals into waterways. 

For firefighters and some foresters, the lawsuit presents its own threat. Curbing use of fire retardants would “have a catastrophic effect on California’s ability to protect communities and infrastructure,” said Ken Pimlott, former director of Cal Fire, the country’s second biggest retardant-sprayer after the Forest Service. More than half the retardant in the country is dumped in California, where a record 4.3 million acres burned in 2020. “I don’t think people fully understand the implications” of the lawsuit, Pimlott said.

As climate change fuels more intense wildfires and threatens more people and property across the West, the lawsuit has exposed a tension between stemming those blazes and protecting lakes and streams. The Forest Service’s defenders — including city officials from Paradise, California, where a 2018 wildfire killed 85 people — say a ruling against the agency could risk lives, houses, and critical infrastructure in a region where a third of the population is vulnerable to wildfires. Critics argue that a decision in the agency’s favor could enable more pollution, continued harm to fish, and further violations of federal clean water law. Dana Christensen, a U.S. district judge in Montana, heard oral arguments in the case last month. He could rule any day.