The U.S. government can keep using chemical retardant dropped from aircraft to fight wildfires, despite finding that the practice pollutes streams in western states in violation of federal law, a judge ruled Friday.
Halting the use of the red slurry material could have resulted in greater environmental damage from wildfires, said U.S. District Judge Dana Christensen in Missoula, Montana.
The judge agreed with U.S. Forest Service officials who said dropping retardant into areas with waterways was sometimes necessary to protect lives and property.
The ruling came after environmentalists sued following revelations that the Forest Service dropped retardant into waterways hundreds of times over the past decade.
Government officials say chemical fire retardant can be crucial to slowing the advance of dangerous blazes. Wildfires across North America have grown bigger and more destructive over the past two decades as climate change warms the planet.
More than 200 loads of retardant got into waterways over the past decade. Federal officials say those situations usually occurred by mistake and in less than 1% of the thousands of loads used annually.
A coalition that includes Paradise, California — where a 2018 blaze killed 85 people and destroyed the town — said a court ruling that stopped the use of retardant would have put lives, homes and forests at risk.
"This case was very personal for us," Paradise Mayor Greg Bolin said. "Our brave firefighters need every tool in the toolbox to protect human lives and property against wildfires, and today's ruling ensures we have a fighting chance this fire season."
State and local agencies lean heavily on the U.S. Forest Service to help fight fires, many of which originate on, or include federal land.
Fire retardant is a specialized mixture of water and chemicals including inorganic fertilizers or salts. It's designed to alter the way fire burns, making blazes less intense and slowing their advance.
That can give firefighters time to steer flames away from inhabited areas and in extreme situations to evacuate people from danger.
"Retardant lasts and even works if it's dry," said Scott Upton, a former region chief and air attack group supervisor for California's state fire agency. "Water is only so good because it dries out. It does very well to suppress fires, but it won't last."
The Oregon-based group Forest Service Employees for Environmental Ethics argued in its lawsuit filed last year that the Forest Service was disregarding federal law by continuing to use retardant without taking adequate precautions to protect streams and rivers.
Christensen said stopping the use of fire retardant would "conceivably result in greater harm from wildfires — including to human life and property and to the environment." The judge said his ruling was limited to 10 western states where members of the plaintiff's group alleged harm from pollution in waterways that they use.
After the lawsuit was filed the Forest Service applied to the Environmental Protection Agency for a permit that would allow it to continue using retardant without breaking the law. The process could take several years.
Forest Service spokesperson Wade Muehlhof said the agency believes retardant can be used "without compromising public health and the environment."
"The Forest Service is working diligently with the Environmental Protection Agency on a general permit for aerially delivered retardant that will allow us to continue using wildfire retardant to protect homes and communities," Muehlhof said.
Climate change, people moving into fire-prone areas, and overgrown forests are creating more catastrophic megafires that are harder to fight.
Many areas of the western U.S. experienced heavy snowfalls this past winter, and as a result fire dangers are lower than in recent years across much of the region.