Big Sioux Water Quality Impact Study

The Big Sioux Water Quality Impact Study will determine the impact of water quality changes in the Big Sioux River on public water supply wellfields in the Big Sioux aquifer. The objectives of this study are to:

• Quantify contribution of river to select wellfields in the upper Big Sioux River watershed.
• Determine potential path of chemical constituents from the river to wellfields.
• Determine chemical constituent concentration gradients between the river and the wellfield.

Tasks in progress include installing observation wells between the river and the wellfields, conducting aquifer tests, determining water quality patterns in the aquifer, and building ground water models to simulate the Big Sioux aquifer under different conditions.