In 2011, prompted by lawsuits from a nonprofit dedicated to national forests, the U.S. Forest Service released a study on the ecological impacts of fire retardant. Aerial drops are “one of the most important tactical tools for wildland firefighters,” the study noted, slowing fire’s progress and helping protect personnel. However, retardant use has killed fish and harmed vegetation, and the study recommended restrictions like avoiding drops on sensitive areas and near water, better monitoring, and protection of cultural resources (“Fire fight: Forest Service explores chemical retardant hazards,” HCN, 6/15/11).
The Forest Service’s usage of retardant has spiked in recent years — it used 19 million gallons in 2016, compared to just under 9 million in 2014. This summer is no different. Huge blazes, including California’s Carr and Mendocino Complex fires, are being fought with aerial retardant by both federal and state agencies; in August, more than a million gallons were dropped on the Mendocino Complex alone. But environmental groups continue to question the usefulness of such drops and the harm done to fish and other wildlife. The Forest Service is planning to complete a multi-year study on the effectiveness of the strategy, due next year.