Brown, orange or cloudy well water often comes from iron, manganese or stirred-up sediment. But if it changed after heavy rain or flooding, surface water may be reaching the well and can carry bacteria. In that case, stop drinking it, use bottled water, and test for coliform bacteria before drinking it again.
Updated October 2026
Safety first: well pumps run on 230/240-volt circuits. Don’t open the pressure switch, control box or well cap wiring.
Well water brown after heavy rain
- Driftless soils are thin and the bedrock is fractured, so rainwater can reach wells quickly. State geologists rate the area highly susceptible to contamination.
- In April 2026, the DNR warned well owners about contamination risk after heavy rain.
- If the well flooded or the water changed, stop drinking it. Use bottled water, or boil for 1 minute if you have no safe option.
- Test for coliform bacteria before drinking it again. DNR says disinfection is best done by a licensed driller or pump installer.
Public Health Madison & Dane County’s lab closed on October 1, 2025, but its staff still help interpret results at 608-243-0357. After the 2018 Black Earth Creek flood, the agency handed out free test kits in affected villages.
Why is my well water brown, orange or cloudy?
| Likely cause | What you can safely check | Needs a licensed pro? |
|---|---|---|
| Surface water after rain | Change followed a storm or flood | Test first; a pro to disinfect and find the entry point |
| Damaged cap or short casing | Look only: is the cap tight and the casing at least 12 inches above ground? | Yes |
| Iron | Orange stains in sinks and toilets | Test; treatment is plumbing work |
| Manganese | Brown or black stains | Test; treatment is plumbing work |
| Stirred-up sediment | Started after an outage; clears with running | No |
| Tiny air bubbles | Cloudy white water clears from the bottom of a glass up | No |
Where to test
- Wisconsin State Laboratory of Hygiene: bacteria $35 (prices from July 1, 2026). 800-442-4618.
- Iowa County Health Department: $35 per test, samples Monday to Thursday. 608-930-9870.
- Green County Public Health: bacteria $30, drop-off Monday to Wednesday. 608-328-9390.
- WellTAP: free testing for eligible households through your local health department.
When you need a licensed professional
- A bacteria test comes back positive.
- The well was flooded, or the cap or casing is damaged.
- Iron or manganese treatment: a licensed plumber, since pump installers’ work ends at the pressure tank.
Wisconsin rules require a DNR-licensed pump installer for pump and pressure-tank work on a drinking-water well; check with DNR if you’re unsure.
