Hydrologic and Geophysical Studies at Midnite Mine, Wellpinit, WA.: Summary of1995 Field Season

摘要

The Midnite Mine is an inactive, hard-rock uranium mine on the Spokane IndianReservation in Washington State. Long-term changes in water quality and the results of slug tests and two geophysical surveys are described. Of the locations monitored, only two exhibited water quality degradation over time. Hydraulic conductivity measurements from slug tests are reported for five additional locations in the bedrock. Relative values of hydraulic conductivity from slug tests agreed well with ranked specific capacity data. A geophysical survey identified buried constructed features that channel subsurface water to a contaminated seep. Historic aerial photos corroborated the results of the geophysical study. A new geophysical technique was successfully used to monitor hydraulic and geochemical responses to a pumping test in saturated waste rock.