An Investigation of Geologic Influences on Groundwater Quality in Douglas County
Hydrology Jack Frame
The North American Midcontinent Rift System (MCR), a geologic formation of igneous and sedimentary rocks formed during the Mesoproterozoic era, runs directly through Douglas County, Wisconsin. There has been extensive research on geologic influences on groundwater quality, though specific geologic influences on groundwater quality in Douglas County are less documented. Prior analysis of private well water quality in Douglas County has revealed an area of high groundwater salinity concentrated around the Douglas fault, a feature of the larger MCR system. The objective of this study was to delineate the area of high groundwater salinity using private well water quality and well construction data from private wells in Douglas County. Private well bedrock geology and proximity to the Douglas fault were analyzed in relation to a suite of groundwater quality data for common groundwater impurities (sodium, chloride, calcium, magnesium, sulfate, etc.). The main bedrock materials found in Douglas County were basalt, sandstone, and unconsolidated material. Preliminary analyses indicate that wells drilled into sandstone or basalt have significantly higher salinity than wells drilled into unconsolidated material. More sampling is required in the area to better understand the role that geological material plays in impacting groundwater salinity in Douglas County. This study could provide useful information for private well owners and water resource managers to better understand the impact of geology on drinking water.
Advisors: Cayla Cavey
Subject Area: Fisheries and Water
Type: Poster
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Jim and Katie Krause CNR Student Research Symposium
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