The Environmental Protection Agency has named four areas in the Animas River basin where it plans to focus on improving water quality for aquatic life.
The EPA recently released a study assessing risks in aquatic habitats, a result of years of sampling and testing water quality in the Animas River basin around Silverton.
Andrew Todd, an aquatic toxicologist for the EPA, said the study confirmed many suspicions throughout the watershed: In areas where water had low pH and elevated metals, fish and other aquatic life populations were highly impaired or non-existent.
But the study also helped inform the EPA about what areas the agency could focus on with cleanup projects, he said, where marked benefits, such as restoring aquatic populations, could be achievable.
The areas include:
The Animas River just below the confluence of Elk Creek, about 5 miles downstream of Silverton.The upper Animas River from Howardsville to just above the confluence with Cement Creek.The south fork of Mineral Creek.Upper Mineral Creek from Mill Creek to just above the confluence with the middle fork of Mineral Creek.Dan Wall, with the EPA’s Superfund program, said establishing early goals is important, allowing the agency to have targets and focus. He said an estimated 12,000 water and soil samples have been taken in the Silverton area since 2009.
“This is an impaired fishery right now,” Wall told a crowd at the EPA’s Community Advisory Group meeting Thursday at the La Plata County Fairgrounds.
Christina Progress, Bonita Peak Mining District Superfund site manager, said a final decision on the EPA’s quick-action plan that seeks to address 26 mining sites over the next five years or so should be announced in the next month or two.
Progress said the cleanup projects in the proposed plan are in line with the EPA’s four identified priority areas.
Weather permitting, Progress told The Durango Herald, the EPA plans to conduct four or five projects this summer. The low water year in 2017-18 and the high water year in 2018-19 are also allowing the EPA to get a better idea of the hydrology of the mountains.
Because Cement Creek has never been known to support aquatic life, it was not considered in this part of the EPA’s process, Progress said. The mines draining into upper Cement Creek are considered some of the worst loaders of heavy metals in the basin.
“We need a lot more understanding of the groundwater system to understand how best to address those (mine) sources,” she said. “We know it’s a significant area of contamination and prohibitive to our overall success.”
Progress said the EPA’s human health risk assessment should also be released in the next month or so. A terrestrial health risk assessment is expected this fall, she said.
This article has been updated to correct the number of samples the Environmental Protection Agency has taken since 2009.