UNVEILING AQUIFER RESPONSES TO GLACIATIONS USING RESIDENTIAL WATER-WELL DATA

The occurrence and rate of groundwater movement depend on storativity and transmissivity of an aquifer. Tectonic movements and glacial drifts can generate enough stresses to the bedrock that can influence these aquifer parameters. The scopes of this research were i) study the variations in hydraulic conductivity of the bedrock aquifer due to cyclic loading and unloading of glaciation, ii) compare the hydraulic conductivity of the bedrock aquifer under glaciated and unglaciated regions, and iii) relate the thickness of glacier cover to aquifer yield. We assumed that glacial loading and unloading developed secondary porosity in the bedrock aquifers due to changes in principal stress conditions. Thus, we hypothesized that glaciated regions would have higher hydraulic conductivity than unglaciated regions and the thicker glacial drift would correlate with higher aquifer yield. To test these hypotheses, we chose two counties in the state of Ohio, one along the maximum glacial extent, Holmes County and another north of it, Portage County. Data obtained from ODNR consists of well location, well construction details, well production test, and rudimentary lithologic descriptions. The results suggested that glacial loading and unloading had significantly impacted bedrock aquifers resulting in higher yield in glaciated areas than in unglaciated areas. Within the glaciated regions, the thicker the glacier drift, the higher the aquifer yield. Such findings are important to anyone interested in withdrawing high volume of groundwater regularly. Besides the local scale, it could also give insights into how bedrock would respond to the change in stress conditions due to glacier melting in context to global warming.