CHAMPAIGN, Ill., 5/18/23: A new database compiling information from a decade of Prairie Research Institute (PRI) studies on the unique geology and hydrology of Jo Daviess County is designed to help residents and officials understand the karst features of the land where they live and to better protect their water supply from surface contamination.
The Karst Feature Database, https://bit.ly/JDC_KarstFeatures, is a product of the long-term collaboration of the Illinois State Water Survey (ISWS) and the Illinois State Geological Survey (ISGS) at PRI, the League of Women Voters (LWV) of Jo Daviess County, and the U.S. Fish and Wildlife Service, which hosts the site and has provided funding. The collaboration began when a large dairy operation was built in the area. Residents were concerned that the liquid manure would contaminate the aquifer that supplies the county’s water.
Jo Daviess County is in a karst area of northwestern Illinois, characterized by sinkholes, caves, springs, and crevices. The terrain is unique in that the aquifer used for water supplies is open to the surface—and surface contamination—through crevices. Although the dairy facility was not completed, karst studies showed the aquifer’s vulnerability to various land uses and practices due to the area’s geology.
“The research provided by PRI scientists has resulted in a better understanding of how karst terrain underlying the entire county is particularly sensitive to human activities conducted on the thin surficial materials overlying highly fractured and erodible bedrock,” said Don Luman, ISGS geologist affiliate, who conducted studies in the county.
PRI studies in Jo Daviess County
During the drought of 2012, an interesting phenomenon happened in alfalfa fields in Jo Daviess County. Green, healthy alfalfa grew in crisscross patterns, but the remaining crop turned brown and died. Walt Kelly, ISWS groundwater geochemist, explained that the deep-rooted alfalfa plants found their way through the cracks and crevices in the bedrock to the water source below, so they thrived even in drought conditions.
Sam Panno, retired ISGS geologist, photographed these patterns from an airplane to target alfalfa fields displaying crop lines. Low-altitude vertical aerial photography acquired by the Illinois Department of Transportation, as well as other imagery sources, were digitized, and Luman used geographic information systems (GIS) to accurately map the complex networks of buried bedrock crevices. In their investigations, they delineated nearly 18,000 crevices, as well as more than 500 sinkholes in the county using light detecting and ranging (LiDAR) technology, which are now showcased in the Karst Feature Database.
In 2018, Kelly and a team of scientists conducted a study on water quality in the county, looking specifically for microplastics. The team found microplastic fibers in most of the water samples they collected from springs. They also found medications and household contaminants that originated from septic waste.
“The water quality in karst regions of the state can be pretty bad since the water sources are open to surface contaminants full of bacteria, viruses, nitrates, and PPCPs,” Kelly said. “Microplastics were becoming a big issue at that time, but no one had ever looked for them in groundwater. This was the first time that anyone had ever reported microplastics found in a groundwater system.”
The results were published in the journal Groundwater in an article titled Microplastic Contamination in Karst Groundwater Systems.
Database applications
All the PRI scientific research from the county and publications have been brought together into the Karst Feature Database, now available to the public. The database contains eight layers that can be viewed together or separately. These layers include watershed boundaries, bedrock crevices and extents, sinkhole locations, groundwater sources including springs and wells, mining boreholes, and named and unnamed mine locations. Five videos describing karst features and a tutorial for the database are also available at http://bit.ly/VideosKFD.
The database has broad application and benefits for the county, according to Beth Baranski, LWV project coordinator and initiator of the entire project a decade ago. The Sheriff’s Department is interested in the location of mine shafts, and the Emergency Management department can use the data on crevices and their orientation in dealing with spill containment, she said. The Planning and Development Office will use the data for project planning and zoning. The County Board of Jo Daviess County has agreed that the county will host the database starting in 2024.
“The database has so many practical applications, but its primary goal is to raise broad awareness of the people of Jo Daviess County about the nature of the hydrogeology in our landscape so we can make better, more thoughtful land use decisions as we go forward,” Baranski said.
The studies also provided baseline data to determine the water quality status now to compare with future conditions when land use and climate changes may have taken a toll, Kelly said.
Protecting the county’s water quality
At an Earth Day event hosted by the LWV to announce the database to the public locally, Kelly answered questions about what property owners and landowners can do to protect their water quality.
“If you live in a karst area, you need to assume that what you and your neighbor are doing at the land surface is going to get into the shallow aquifer,” Kelly said. “You want to be careful about the pesticides and fertilizers you’re using on lawns and in gardens, and don’t use them if it’s raining. Education is really important for things like this.”
Stormwater management is also critical, Baranski said. The city of Galena has a stormwater ordinance in place, and Baranski plans to talk about ordinances with officials in other towns of the county.
“We think stormwater management is the key piece to almost all our problems here,” she said. “Anything that can be done to reduce water runoff will improve a lot of things here, including poor water quality, infrastructure damage, flooding, and erosion.”
For questions about the Karst Feature Database, contact Beth Baranski at beth@bhms-arch.com, 563-580-6192.
----
Media contacts: Walt Kelly, wkelly@illinois.edu, 217-333-3729; Beth Baranski, beth@bhms-arch.com, 563-580-6192; Don Luman, luman@illinois.edu
news@prairie.illinois.edu