Home / Environment / Forever Chemicals Plague Big Sioux River
Forever Chemicals Plague Big Sioux River
12 Apr
Summary
- Highest PFAS concentrations found in Sioux Falls and near Watertown.
- Study found 15 types of PFAS compounds, some exceeding EPA limits.
- PFAS linked to health risks; filtration system development is underway.
The Big Sioux River in South Dakota is showing concerning levels of per- and polyfluoroalkyl substances (PFAS), commonly known as "forever chemicals." A comprehensive study conducted between September 2024 and the end of 2025 identified the highest concentrations in Sioux Falls and near Watertown.
The research tested water at 13 sites and detected 15 different PFAS compounds. Notably, some samples exceeded the Environmental Protection Agency's (EPA) established limits for drinking water, particularly near the Sioux Falls Regional Airport and Falls Park. PFAS compounds, used in various industrial and consumer products since the 1940s, are persistent in the environment and the human body and are linked to potential negative health effects.
Concerns are amplified as the Big Sioux River's water can infiltrate nearby wells. While EPA finalized limits for drinking water in 2024 with phased implementation starting in 2027, these limits do not directly apply to surface water. However, managers of public drinking water systems near the river are advised to be aware of the findings.
In response to these detections, researchers are developing water filtration systems specifically for PFAS. The South Dakota Department of Agriculture and Natural Resources is also conducting its own study on PFAS in the state's surface waters, expected to conclude this year. Water sampling for PFAS in the Big Sioux River is planned to continue in 2026.
