Linn County water studies will pay dividends

Linn County has joined with University of Iowa researchers to conduct studies of surface water and underground aquifers in the county. At an estimated price tag of $130,000, it’s a bargain, given the importance of the information it will provide.

The studies include an aquifer vulnerability map, a contaminant plume map and a surface water sampling assessment to be completed in collaboration with UI researchers through Sept. 30, 2026.

Among the researchers are Marty St. Clair, a research scientist at IIHR-Hydroscience and the Engineering Center for Health Effects of Environmental Contamination. Keith Schilling is the State Geologist with the IA Geological Survey, IGS, a Research Engineer and adjunct assistant professor of Earth and Environmental Sciences.

Researchers say groundwater studies aim to determine where groundwater is recharged, identify potential contaminant sources, and map areas with the highest risk of contamination, either from point sources like contaminated sites or nonpoint sources, including cropland.

There also will be research into “groundwater contaminant plumes,” mapping known sources of pollution such as underground tanks and landfills. The studies will study groundwater “travel time,” or how much time it takes water to move from the surface to the aquifer. Analysis will include records of 3,000 wells in the county.

“The goal will be to put all the plumes on a map (aka GIS database) so anyone installing a well in the county knows where contamination has been found,” Schilling said in an email.

Large water users will be mapped and assessed to measure the risk of plume migration.

Also, a surface water study will pull together known data currently scattered in different databases. It will provide data to the county for developing a monitoring plan.

“One of the goals is to get existing data (and future) into an easily accessible form that the public can see and utilize,” St. Clair said.

Combined, the studies will create a much clearer picture of groundwater uses and contamination, map pollution threats and pull together valuable data on surface waters.

Again, we think collaborative research will pay dividends in the future. County water policy will be smarter and more effective thanks to the data. County residents who want to know if their wells are threatened by contamination can get answers. It’s money well spent.

(319) 398-8262; editorial@thegazette.com