Author(s): Cecilia Y. Jeje; Ben Parsons; Tim R. Ezzy; Chris Langton
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Keywords: No Keywords
Abstract: The Alberta Oil Sands are located in one of the world's largest intact ecosystems, an area rich in fauna and flora. The Fort Hills Oil Sands Mine area includes the large regionally sensitive boreal McClelland Lake Wetland Complex (MLWC) located north of Fort McMurray in Alberta. The complex located at the foot of the Fort Hills moraine, is one of the largest wetlands in the province, approximately 6,695 hectares in size and comprises a rich fen with a patterned component and the McClelland Lake located to the east. The low lying fen is a sink for shallow groundwater sources, each contributing various quantities and qualities of water. A regional groundwater model was established to understand the quantity of groundwater flowing into the fen under natural conditions. The patterned fen is recognized as regionally significant, and a portion of the patterned fen will not be disturbed during the life of the mine. Similarly, the unpatterned fen will remain undisturbed before it will be impacted by mining activities. These activities bring challenge to maintaining the integrity of the fen during operations and at closure. This has necessitated the development of a mitigation plan which includes the creation of a hydraulic break to prevent drainage of the fen into the nearby mine and the creation of a mechanism to sustain the fen with a water source of similar composition. The fundamental forces which interact to create the ecology and structure of the MLWC ecosystem include the hydrology, geomorphic setting, hydrogeology and physical, biological and biogeochemical processes. The groundwater model provides a tool for assessing mining impacts, and the potential effectiveness of mitigation options. This paper presents technical details of groundwater hydraulics and modeling in relation to the current ecological integrity of MLWC, option selection for a water source to sustain the fen, and evaluation of preferred performance standards.
Year: 2009