Groundwater Hydrologic Regimes Within Reclaimed Surface Coal Mined Landscapes in Alberta

Between 1979 and 1988, the Plains Hydrology and Reclamation Project (PHRP) investigated interactions of groundwater, soils, and geology and successful reclamation of surface coal mines in the plains of Alberta. Among the objectives of the study was to document the processes by which a steady-state hydrologic regime was re-established following reclamation and to determine the rate at which steady-state conditions were attained. Instrumentation was installed in spoil at two study areas: the Battle River area, which included Diplomat, Vesta and Paintearth Mines, and the Wabamun area, which included the Highvale and Whitewood Mines. Our work demonstrated that the processes by which water enters the spoil and the rate at which the post-reclamation steady-state equilibrium hydrologic regime is established differ both within and between mine sites depending on the hydraulic conductivity of the spoil and the landscape setting within the reclaimed terrain. In lowland settings at mines characterized by high permeability spoil, steady-state equilibrium conditions are established within 5 to 10 years of regrading. In upland settings at mines characterized by low permeability spoil, on the other hand, many decades are required to establish steady-state equilibrium conditions.