FAIRBANKS—Two North Pole-area lakes that were recently closed to fishing because of water pollution had concentrations of contaminants well above Environmental Protect Agency advisory levels.
Alaska’s Department of Fish and Game announced the closure Wednesday of both Kimberly Lake, which is northwest of North Pole High School off of Roseanne Court, and Polaris Lake on Eielson Air Force Base.
In addition to closing these two lakes, the Alaska Department of Fish and Game has suspended the stocking of hatchery fish to all lakes on Eielson Air Force Base, said Tim Viavant regional management coordinator for the Department of Fish and Game in a phone interview Friday.
The contaminants in the water — and likely in the fish — are types of man-made chemicals known as PFAS, which stands for per- and polyfluoroalkyl substances. They’re used in numerous consumer products from nonstick frying pans to raincoats, although most of the water contamination in Alaska is linked to firefighting foam. They’re a type of pollutant that’s known as an “emerging contaminant” because it’s been found to cause sickness in animals, but the extent of its risks to humans isn’t well understood.
The sport fishing closure came about because the Alaska Department of Environmental Conservation approached Fish and Game about testing for the contaminant at Kimberly Lake. A subsequent discussion of the contamination at Polaris Lake led to the closure of both lakes to fishing.
Viavant said this is the first fishing closure he knows of in Alaska triggered by the presence of PFAS in water.
“This is a brand new issue for the Alaska Department of Fish and Game, and ADFG’s leadership is trying to figure out the best way to proceed,” he said.
Back in the 1990s, Eielson Air Force Base began instructing anglers not consume fish caught in Garrison Slough on base because of a different type of contaminant, polychlorinated biphenyls, also known as PCBs.
Laura Achee, a spokeswoman for the Department of Environmental Conservation, said no other fish-bearing bodies of water in Alaska besides Kimberly and Polaris lakes have been found to have PFAS concentrations higher than the EPA standards.
However, not much testing has been done on the surface of lakes.
“The primary focus on PFAS sampling and response has been aimed at potential drinking water impacts. Limited surface water sampling has been conducted to date,” Achee said by email.
Water testing on Polaris Lake was done in October 2016 after firefighting foam was accidentally discharged into the lake, Achee said.
At Polaris Lake, the concentrations at the top of the water column were the highest, totaling 249 parts per trillion for one specific type of PFAS called PFOS or perfluorooctanesulfonic acid.
The EPA health advisory level for PFOS is 70 parts per trillion. An advisory level is a nonbinding standard used while the agency determines formal standards.
Last year, the state stocked Polaris Lake with more than 7,000 chinook salmon, rainbow trout, and Arctic char from the Ruth Burnett Sport Fish Hatchery in Fairbanks.
Kimberly Lake was tested for PFAS in October 2018, Achee said. Testing at the lake was done as part of testing for groundwater PFAS near the former Flint Hills Refinery near the lake.
Kimberly Lake was stocked with about 300 rainbow trout last year.