PORTLAND, Ore. (KOIN) — On Aug. 25, firefighters battling the Camp Creek Fire performed multiple fire-retardant drops to slow the spread of the wildfire burning in the Bull Run Watershed — Portland’s primary source of freshwater. While no significant amount of retardant is believed to have entered Portland’s water at this time, officials say that any impacts from retardant drops would be “negligible” to human health.

As of Aug. 29, no retardant has been used within the “defined exclusion zone” that drains into the Bull Run Reservoirs, Portland Bureau of Emergency Management spokesperson Jaymee Cuti told KOIN 6 News. Firefighters have been directed to avoid drops in this area in order to protect the quality of the drinking water. However, if the Camp Creek Fire seriously threatens the Portland Water Bureau’s water treatment plant, officials said that firefighters may have to perform retardant drops in the area.

“If the U.S. Forest Service decides that fire retardant must be used to prevent a catastrophic fire in the watershed, the Multnomah County Health Department has determined that the risk to human health would be negligible,” Cuti said. “First, because of the retardant’s components: 85% water, 10% fertilizer and 5% minor ingredients. And second, because of dilution by the billions of gallons of water in the reservoirs. At all times, water quality from the Bull Run is rigorously monitored.”

The retardant drops were made on the southernmost perimeter of the Camp Creek Fire (seen in red), officials said. This was roughly 3 to 4 miles southeast of PWB’s water treatment plant. (Camp Creek Fire incident management team)

While local government officials have not publicly disclosed the “minor” ingredients that make up 5% of the federally regulated retardant solution, Sierra Hellstrom, an information officer with the Camp Creek Fire incident command team, told KOIN 6 News that, thanks to fire retardant studies performed in recent decades, all of the ingredients used in the retardant are now USDA food-grade quality that “pose no risk no danger to people or animals if ingested directly.”

“We’re continuously making sure we minimize that impact as much as possible,” Hellstrom said.

Fire retardants used by government officials in past decades have sometimes contained potentially hazardous “forever chemicals” and sodium ferrocyanide, an anticorrosive agent that produces cyanide when exposed to ultraviolet light. However, Hellstrom said that these issues have been resolved and all public and private makers of fire retardant used by U.S. wildland firefighters are regularly inspected to ensure they are following strict ingredient guidelines.

Hellstrom said that the “5% minor ingredients” used in the retardant include colorant — essentially food dye — and “natural gum and clay thickeners” that makes the solution stickier and water absorbent.

The Camp Creek Fire threatening the Portland Water Bureau’s water treatment plant. (Camp Creek Fire incident management team)

While the retardant solution is said to be moderately safe for ingestion by humans and animals, the retardant drops to have a measurable impact on plant life, Hellstrom said. The use of fertilizer in the retardant formula, studies show, can change soil chemistry and aid in the spread of invasive species.

“We still try to avoid waterways and those areas as much as possible to avoid any impact to drinking water and plant life,” Hellstrom said.

Other than being ingested, the USDA studies show that the retardant can have minor impacts on skin or eyes, especially if the people who come in contact with the retardant are allergic to any of its ingredients. However, this type of exposure is not thought to be fatal.

“Even though it’s not going to kill you, they recommend washing your hands [if you touch it],” Hellstrom said.

The fire-retardant drops made near the Bull Run Watershed were performed roughly three to four miles east of the PWB treatment plant along Forest Road 14 to prevent the fire from jumping the road. Access to this region of the Mount Hood National Forest is already off-limits for public recreation due to water-protection laws.

If firefighters are unable to protect the trees surrounding the Bull Run reservoirs, the City of Portland said that losing forest cover could also affect water quality. This could have impacts on Portland’s drinking water and the habitat of the federally protected species that live within the watershed — including the endangered spotted owl and the “threatened” steelhead, Chinook and Coho salmon.