Fouled wells require disinfection

The state Department of Public Health is reminding private well owners that wells can become contaminated due to flooding and can require disinfection.

Flooding is anticipated due to heavy rainfall and storm surges from Tropical Storm Irene.

Water should be pumped or allowed to recede from around the well before the well is disinfected, the health department said in a news release Friday. Homeowners with dug wells should expose their wells and clean them of debris. If the electrical panel or connections have been submerged, a licensed electrician should evaluate the electrical panel and connections prior to the homeowner handling them.

To ensure water is free from bacteriological contaminants, the well should be sampled after it has been disinfected and tested by a certified laboratory. If there are other suspected contaminants, people should notify their local health department.

For information, contact the state Department of Public Health, Environmental Health Section, Private Well Program at (860) 509-7296.

To disinfect a private well:

• Use non-scented chlorine bleach in a bleach solution greater than 5.25 percent.

• If you have water treatment devices, remove all membranes, filters, cartridges, charcoal filters, etc. after the chlorination process is completed.

• If the water is discolored or if you have debris in your dug well, clean the well of debris.

• Do not disinfect the well until floodwaters have receded.

• Run water until it is relatively clear.

• Drain your storage tank and hot water tank, so that chlorinated water will also enter that tank.

• Mix up a batch of chlorinated water in a 5-gallon pail and use this mixture to clean along the top of the well. One-half cup to 1 cup of bleach (5.25 percent) in 5 gallons of water is a good concentration.

• A licensed plumber, pump installer or well driller can also be contacted to do the disinfection.

• The chlorine batch in the 5-gallon bucket should be poured into the well so that it swirls around the interior casing.

• Re-cap the well and then proceed to open each hot and cold faucet (inside and outside the house), until a distinct chlorine odor is observed. Then shut each faucet.

• If you do not detect a strong chlorine odor you may want to add more bleach and repeat the process.

• Allow the chlorinated water to remain in the water system for at least 6 hours and preferably overnight.

• Backwash water softeners, sand filters and iron removal filters with chlorinated water.

• Open all faucets individually and run the water until there is no chlorine smell - may take 15 minutes or more.

• Make sure on outside faucets that chlorinated water is diverted from plants and shrubs because chlorinated water will kill the vegetation.

Additional Resources:;; EPA website:;
"What To Do After The Flood"- private wells and septic systems:;

For information on food and water safety during hurricanes, power outages, and floods, visit:


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