State officials say now that the spring thaw has passed, residents with private wells should consider having them tested.
Mark Putra with the DNR says the spring thaw can cause problems because of infiltration and water movement, which usually becomes more apparent this time of year. Municipal water is tested frequently, but private wells should test at least once a year, too.
Putra says having a test done is fairly simple. Owners can order a bottle from state or private labs, collect a sample, and then send it in for testing.
The most common contaminants are simple bacteria, but wells located in agricultural areas may also experience pesticide or fertilizer contamination. Putra says an estimated 10-12% of the state's wells exceed nitrate standards.
If your well water smells like rotten eggs or iron, don't worry. It's likely a harmless iron or sulfur bacteria problem.
Nearly one million Wisconsin households get their drinking water from private wells.