Jenny Kozak, a master’s student at South Dakota Mines, pours Big Sioux River water into a collection bottle on Sept. 26 near Egan. The sample will be tested for PFAS compounds. (Makenzie Huber/South Dakota Searchlight)
The murky brown Big Sioux River consistently receives poor marks for its water quality , but eastern South Dakota water systems near the river don’t know if that pollution includes “forever chemicals.”
To find out, researchers from South Dakota Mines are testing for per- and polyfluoroalkyl substances (PFAS) at the behest of the East Dakota Water Development District.
The study will cost the district at least $100,000 to test 11 sites from northeast South Dakota to the Iowa border past Sioux Falls, including four more sample runs throughout 2025.
“Ideally, we’ll find nothing, and we’ll have spent a lot of money to do that,” said Jay Gilbertson, district manager. “But right now, we don’t know if there is PFAS in the river. It’s hard to be proactive and plan if you don’t have information.”