Groundwater Flow and Contaminant Transport at the Interface Between Fractured Bedrock and Surface Water

点击翻译按钮获取中文摘要

This research concerns contaminated groundwater in bedrock discharging directly from rock fractures into surface water, most notably rivers and ocean estuaries. Research will be conducted in two study areas: along the Eramosa River in Guelph, Ontario where the river water flows directly on the exposed dolostone, and an area of springs along the shoreline of an ocean estuary receiving nitrate-contaminated groundwater in Prince Edward Island (PEI). Many industrial and municipal activities in Guelph have caused groundwater contamination in the underlying fractured bedrock (dolostone) that flow towards the Eramosa River. In PEI, groundwater contaminated with nitrates as a result of potato farming flows in fractured bedrock towards ocean estuaries which are important to the shellfish industry. These two study areas were selected for their favourable features such as access (i.e., public land) and exposed rock surfaces, which are suitable to begin this exploration of bedrock groundwater-surface water interactions. New methods for sampling and monitoring groundwater in the bedrock will be developed and tested, including adaptation of small portable drills, used globally in mineral exploration, for use in ecologically sensitive and/or with difficult access area such as rivers and estuaries. Miniaturized monitoring devices will be installed in holes made by these small portable drills creating holes up to 50 m deep in a manner that minimizes environmental damage. These drills make holes much smaller in diameter than larger conventional drills and therefore equipment to acquire information from these small diameter holes must be developed. Monitoring of the groundwater and surface water temperature and salinity using novel methods will be used to locate and understand the nature of the groundwater discharge to the surface water. The goal is to develop a comprehensive approach for examining groundwater-surface water interactions at bedrock-surface water interfaces. Once developed, this approach will advance understanding in many other areas, such as along bedrock shorelines of the Great Lakes and along numerous rivers and ocean shorelines where contaminated groundwater discharges from bedrock.