HYDROLOGY OF THE PROPOSED NATIONAL UNDERGROUND SCIENCE LABORATORY AT THE HOMESTAKE MINE IN LEAD, SOUTH DAKOTA

摘要

The proposed National Underground Science Laboratory will behoused in the former Homestake Gold Mine at Lead, South Dakota.Uses will include underground neutrino experiments that must beshielded by several thousand feet of rock, as well as ground-waterresearch in fracture-flow environments, and investigation of themicrobiology of extreme environments. The Homestake Mine hasabout 300 miles of underground workings. Seepage of ground waterinto the mine openings is approximately 500 gallons per minute.Average annual precipitation in the northern Black Hills isapproximately 28 inches per year. The majority of this becomessurface-water runoff or evapotranspiration, with little ground-waterrecharge because of the low permeability of the Precambrian rocks inthe area. Dewatering of the workings over the 125 years of operationof the mine has influenced the subsurface hydrology of the 8,000-footdeep mine.