UBC Theses and Dissertations
An electric analog simulation of ground water flow patterns at a potash waste disposal pond located near Esterhazy, Saskatchewan Bourne, Douglas Randal
This study reports the results of an investigation of the potential pollution hazard of a potash brine disposal pond located near Esterhazy, Saskatchewan. The most serious problems associated with the brine pond are the potential pollution of groundwater resources and the possible contamination of a nearby stream by groundwater discharge. The primary geologic feature is a glacial buried valley aquifer consisting of highly-permeable sands and gravels. A three dimensional electric analog model was constructed to simulate the steady state and transient groundwater flow systems in the buried valley aquifer. The steady state analysis enabled the author to calculate the convective travel times of the brine from the brine pond to the nearby creek. The transient analysis was used to assess the feasibility of reversing the hydraulic gradient in the buried valley aquifer. Steady state results indicate that the most serious potential pollution hazard is brine seepage onto the surface immediately east of the brine pond. At a distance of 5600 feet from the brine pond, this seepage will occur within 30 years; nearer to the brine pond, it will occur sooner. This type of brine seepage could enter the nearby stream as a result of surface drainage. Brine pollution by groundwater discharge directly into the creek will take between 640 to 1260 years, so this mechanism does not pose an immediate pollution hazard. Transient results indicate that low-rate injection wells (up to 50 IGPM) would not reverse the hydraulic gradient in the buried valley aquifer. Injection rates between 370 to 575 IGPM would be required, but fresh water supplies of this magnitude are not available. The design of future brine ponds should include seepage calculations in the initial phases of design instead of after the fact.
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