The upper Blackfoot River of southeastern Idaho receives runoff from 12 large phosphate mines. Waste shales removed during mining are highly enriched in selenium, resulting in high selenium concentrations in runoff from the mine waste dumps. Beginning in 2001, the USGS, in cooperation with the Bureau of Land Management has monitored streamflow and collected water-quality samples from the Blackfoot River just upstream of Blackfoot Reservoir. Read more >
In this report, hdyrologist Greg Clark analyzes water-quality data that the USGS has collected on behalf of the Environmental Protection Agency in and around the Bunker Hill Superfund site in northern Idaho. The data show that concentrations of three trace metals of concern—cadmium, lead, and zinc—have declined significantly since the 1990s.
USGS and Idaho Department of Environmental Quality scientists combined and analyzed data sets from two separate water-quality monitoring efforts in the upper Blackfoot River basin in southeastern Idaho. Naturally occuring selenium washed into the river from phosphate mines has raised concerns about possible impacts to fish and other aquatic life forms in the basin, as well as grazing livestock.