Aquifer susceptibility and GIS: Illustrating the need for scrutiny and localized reconnaissance work.

The city of Cedar Falls, Iowa and the University of Northern Iowa rely heavily on a highly productive carbonate bedrock aquifer underlying this portion of the state as a municipal water supply and a source of once through cooling-water, respectively. This high quality groundwater resource is also tapped by local residents, businesses, and other entities for private drinking water and an ever-growing number of geothermal installations.

Detailed hydrogeological and historical work recently completed in this area used geographic information system (GIS) software to reveal, analyze, and illustrate some significant findings regarding aquifer susceptibility, source water protection, groundwater contaminant sources, and past hydrogeological misconceptions about the area. This presentation will highlight how GIS was combined with a simple mix of primary and secondary data to uncover and illustrate a much more representative picture of this aquifer’s characteristics and vulnerability to surface contamination. Findings show that more focused, detailed efforts are needed to accurately characterize local hydrogeological conditions and provide more reliable data needed for source water protection, planning and zoning decision making, municipal well siting, and watershed restoration efforts.