Mine Hydrology: Former Oil Shale Mine
Garfield County, Colorado
Western Water & Land is conducting closure activities for a former oil shale mine in western Colorado. As part of closure operations, Western Water & Land conducted a comprehensive underground hydrologic reconnaissance and groundwater sampling program from underground wells. Reconnaissance findings supported development of a hydrologic conceptual flow model which was used in combination with the sampling analytical results to demonstrate that mine operations had not contaminated the aquifer underlying the mine workings. In addition, mine water management actions implemented by Western Water & Land resulted in a decrease in mine water discharge and inactivation of a National Pollutant Discharge Elimination System (NPDES) permit for the mine, resulting in significant cost savings to the mine owner. Western Water & Land worked closely with the Colorado Division of Reclamation, Mining, and Safety and Colorado Department of Public Health and Environment to accomplish permit inactivation.
Mine water discharging from the underground retorts (large chambers constructed to test oil shale retort options) pose one of the greatest challenges for ultimate mine closure. Historically, the water has been managed by being discharged to an evaporation pond, which is not an acceptable long-term remedy for the mine. Subsequently, Western Water & Land has evaluated treatment options for the retort water including construction and testing of a passive bioreactor cell. We are currently evaluating the feasibility of alternative management options for the retort water to avoid long-term operation and maintenance obligations. The alternatives being considered include bioremediation, grout seals, underground injection, and natural attenuation.
Garfield County, Colorado
Western Water & Land is conducting closure activities for a former oil shale mine in western Colorado. As part of closure operations, Western Water & Land conducted a comprehensive underground hydrologic reconnaissance and groundwater sampling program from underground wells. Reconnaissance findings supported development of a hydrologic conceptual flow model which was used in combination with the sampling analytical results to demonstrate that mine operations had not contaminated the aquifer underlying the mine workings. In addition, mine water management actions implemented by Western Water & Land resulted in a decrease in mine water discharge and inactivation of a National Pollutant Discharge Elimination System (NPDES) permit for the mine, resulting in significant cost savings to the mine owner. Western Water & Land worked closely with the Colorado Division of Reclamation, Mining, and Safety and Colorado Department of Public Health and Environment to accomplish permit inactivation.
Mine water discharging from the underground retorts (large chambers constructed to test oil shale retort options) pose one of the greatest challenges for ultimate mine closure. Historically, the water has been managed by being discharged to an evaporation pond, which is not an acceptable long-term remedy for the mine. Subsequently, Western Water & Land has evaluated treatment options for the retort water including construction and testing of a passive bioreactor cell. We are currently evaluating the feasibility of alternative management options for the retort water to avoid long-term operation and maintenance obligations. The alternatives being considered include bioremediation, grout seals, underground injection, and natural attenuation.