REVEALING 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 change in principal stress conditions thus influencing those aquifer parameters. The scopes of this research were to 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) correlate the aquifer parameters (thickness and depth) with hydraulic conductivity of the aquifer. It was 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, data collected from 14 counties in northeastern Ohio that consist of well location, well construction details, well production test, and rudimentary lithological descriptions. These results suggested that glacial loading and unloading had significantly impacted bedrock aquifers resulting in higher yield for glaciated areas than for unglaciated areas. Generally, the northern counties had higher median hydraulic conductivity than the southern counties. The distribution curves of hydraulic conductivity of the aquifer was tighter and shifted right significantly for glaciated regions than that for unglaciated regions. Such findings are important to anyone interested in withdrawing high volume of groundwater on regular basis. 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 and subsequent change in the stress field in the bedrock which have implications to the slope stability.