Sample well water to ensure its safety after flooding

Farm Forum

BROOKINGS, S.D. — Flooding increases the risk of surface water entering the well bore, and surface water may carry contaminants into the well such as harmful bacteria, nitrate or chemicals from fuel storage tanks or pesticide containers, said Jeppe Kjaersgaard, Assistant Professor in the Agricultural & Biosystems Engineering Department at South Dakota State University.

“These contaminants may all pose a health risk for humans and animals, but in particular, babies, pregnant women and those who are sick or elderly,” Kjaersgaard said.

If you suspect surface water has entered your well, Kjaersgaard said a good precaution is to stop using the water.

“Boiling water does NOT rid water of all contaminants. The best way to determine whether your well water is safe to use is to collect a water sample and submit it to a laboratory for analysis,” said Kjaersgaard.

The State of South Dakota maintains a list of laboratories certified for the analysis of drinking water.

Kjaersgaard references an on-line tool homeowners can use for a first-cut interpretation of the water analysis results: Water Quality Intrepretation Tool found at For a complete interpretation, contact the South Dakota Water Resources Institute or the South Dakota Department of Environment and Natural Resources to discuss any questions or concerns you have about the quality of your drinking water.

If your well is contaminated at unsafe levels, stop using it for drinking or cooking. In the short term, buy or bring in water from a safe water source.

Contact a commercial water treatment vendor or the South Dakota Water Resources Institute for remediation options. More information about nitrates in drinking water can be found at iGrow.