A study published in Hydrogeology Journal https://doi.org/10.1007/s10040-024-02871-2 reveals new information about groundwater age (residence time) in the distinctive karst landscape within Minnesota’s Driftless Area, USA.
Researchers examined current concentrations of a discontinued row-crop herbicide, popular in the 1970s and 1980s, in springs and wells, then compared these data against its historical use. These results were combined with independent age-dating methods to reveal a mixture of groundwater ages, ranging from 10 to 40 years old in many of the region’s shallower springs and wells to thousands of years old in deeper aquifers.
The combination of groundwater residence time, historical land use, and climatic information was also applied to the interpretation of nitrate concentration trends for nearly 1,200 well, spring, and stream monitoring locations over the past 20 years.
Groundwater emanating from a spring and flowing into a cold-water trout stream in Minnesota’s karst landscape. Photograph accreditation: Kevin Kuehner
Discover groundwater’s fascinating, complex movement in Minnesota’s karst landscape (Minnesota Department of Agriculture). https://www.youtube.com/playlist?list=PL8pqzQfMH1BgX_AIw4TXhmF6Ogcl-8_Fm
Explore the distribution of springs across Minnesota (Minnesota Department of Natural Resources).
https://www.dnr.state.mn.us/waters/groundwater_section/mapping/springs-msi.html
