Factors affecting residential water well yield in the vicinity of room and pillar mines.
Proceedings of the third workshop on surface subsidence due to underground mining, June 1-4, 1992, Morgantown, West Virginia. Peng SS, Holland CT, ed. Morgantown, WV: West Virginia University, 1992 Jun; :244-252
The Bureau of Mines is conducting an investigation to develop remediation techniques for residential water wells whose yield has been affected in the long term, by underground mining. Initial work relating to this project was conducted in 1984-1987 at a room and pillar mine in Indiana County, Pennsylvania. This paper reports that piezometer nest data from the room and pillar mine reveals that a downward gradient in piezometric head exists in shallow strata as a result of drainage into the underlying mine void. The vertical gradient in head in turn results in well bore leakage in open-hole water wells. The relative yield of valley wells is only slightly affected however because the high surficial recharge rate through fractures more than compensates for fracture leakage into the underlying mine. The relative affect of well bore leakages on well yield is greater in certain hillside and hilltop wells that have comparatively low inflow rates at shallow depths. The static water level of such wells is determined to a much greater extent by the chance interception of deep outflow fractures, than is the case for wells drilled in a more intensively fractured valley bottom.
Mining-industry; Underground-mining; Environmental-pollution; Environmental-protection; Environmental-contamination
Proceedings of the third workshop on surface subsidence due to underground mining, June 1-4, 1992, Morgantown, West Virginia