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Water quality and discharge data from draining mine tunnels near Silverton, Colorado 1993-2015

May 7, 2021

The American Tunnel, the Black Hawk mine, the Gold King mine, the Mogul mine, and the Red and Bonita mine are located in the Cement Creek watershed, tributary to the upper Animas River near Silverton, Colorado. All five sites have tunnels that drain groundwater from abandoned underground mine workings to the surface. This draining water has elevated concentrations of metals and degrades water quality in Cement Creek. Water quality (pH, and dissolved copper, manganese, and zinc concentrations) and discharge data were compiled from multiple sources to examine changes in these parameters through time. Copper, manganese, and zinc loads calculated from these data are included in the data files. Data are reported for the American Tunnel (November 1988 through July 2015), the Black Hawk mine (September 1991 through September 2005), the Gold King mine (August 1993 through July 2015), the Mogul mine (July 1992 through July 2015), and the Red and Bonita mine (June 1997 through July 2015).