Mining in the West often results in polluted watersheds, but a new study shows efforts to clean up leaking mines are extremely effective.
Researchers from Colorado State University, the University of California Santa Barbara and the U.S. Geological Survey worked on the study, which looked at the effects of mine remediation on four mountain streams in California, Idaho, Montana and Colorado.
The streams were all designated by the Environmental Protection Agency as Superfund sites, which means they were extremely polluted.
“They started off as being, if not devoid of life, pretty close to that,” said Will Clements, one of the researchers. “And then in a fairly short period of time, 10 to 15 years, they all had made this remarkable recovery.”
The researchers used data collected over the course of 20 to 29 years at each site. They looked at ecological factors, like which species recovered most quickly, as well as chemical factors like what metals were present in the water.
They used samples from nearby streams to determine what recovery looked like.
David Herbst, another author of the study, said it’s the first time researchers have looked at the effect of mine remediation on different streams over a long period of time.
“It gives us a much more accurate idea of how long it takes for these things to be successful, because typically a restoration project doesn't happen overnight,” he said.
Despite the fact that each site had different contaminants and different ecology, they all recovered in approximately the same amount of time. Herbst said that means the results can likely be applied to polluted streams across the mountain west.
Clements said that includes the San Juan River in Southeast Utah, which was polluted by the Gold King Mine Spill in 2015. That mine is currently undergoing remediation by the EPA.
There are currently 17,000 abandoned mine openings across Utah, according to the state's Division of Oil, Gas and Mining. Not all of them are polluting waterways.
