Montana officials will remove Soda Butte Creek, which flows into Yellowstone National Park, from a list of impaired streams next year.
The move is an acknowledgement of strides made to remove heavy metals leached into the creek from abandoned mine sites.
According to the Bozeman Daily Chronicle, the Montana Department of Environmental Quality received preliminary approval from the Environmental Protection Agency to remove Soda Butte Creek from their Impaired Waters List. According to Autumn Coleman, manager of the DEQ’s abandoned mine lands program, this is the first time a stream has been delisted due to a mine cleanup. From the Chronicle:
Soda Butte Creek flows past the town of Cooke City and into Yellowstone National Park, where it feeds the Lamar River. Until 1953, the McLaren Mill operated on its banks just outside of the town. The mill processed ore that miners pulled out of a pit in the mountains.
While the mill was in operation, Soda Butte Creek was rerouted and mill waste was dumped behind a primitive dam, creating a tailings pond. The dam leaked, sending acid mine drainage into the creek.
Cleanups in the area began in the late 1990s, after a settlement between the federal government and Crown Butte Mining Inc. The Forest Service removed some of the tailings in the mid-2000s, and DEQ began construction there in 2010.
DEQ pulled out the rest of the tailings and buried them in a repository on a hill above the creek. DEQ also moved Soda Butte Creek back to the center of the meadow and planted vegetation. The entire project cost around $24.5 million and was completed in 2014.
Darrin Kron, a water quality specialist for DEQ, said water sampling shows that the loads of heavy metals in the stream are far below what they once were.
“The data showed that the cleanup made the water in the stream meet all of our metals standards,” he said. “That’s pretty significant.
The DEQ will release its water quality report next year and solicit public comment. After that, the EPA will review the report.
The Chronicle reports that mine cleanup has had a noticeable benefit on the stream’s fish population, especially cutthroat trout. For the past few years, Yellowstone biologists have put down piscicide to kill non-native trout species in streams like Soda Butte, in order to restore native cutthroat trout.