Heather N. Kolich, ANR Agent, UGA Extension Forsyth County

A stream of water splashing in a puddle.
Heavy rainfall and flooding can carry surface pollutants and pathogens into wells.

While well water in Georgia is generally very safe for drinking, cooking, and household use, UGA and EPD recommend annual testing of well water to monitor pH, naturally occurring mineral levels, and bacterial contamination. Weather events, well damage, and geographic region may warrant additional testing.

Heavy rainfall and flooding can carry surface pollutants and pathogens into wells. Wells that are situated on low ground are more likely to become contaminated with pollutants and bacteria from being overtopped with standing rainwater runoff and rising flood waters than higher placed wells are.

Drinking well water that has been contaminated with bacteria, viruses, and parasites can cause immediate illness. If your well was overtopped with flood water during a storm, it’s advisable to act immediately to cleanse the well rather than wait for test results.

As soon as possible after flooding, use an outside spigot to pump a minimum of 2 to 3 times the well volume out of the well. This action helps to clear the well of flood water and potential contaminants, including bacteria. Discarding this water from an outside spigot keeps potentially contaminated water out of the indoor plumbing system and avoids overwhelming your septic system with an excess volume of water.

After the initial pump out, pour 3 pints per 100 gallons of well capacity of plain, unscented household chlorine bleach into your well to disinfect it. The bleach must stay in the system for 12-24 hours. At the end of the treatment period, pump out another 3 or 4 times the volume of the well. Again, the majority of this water should be discarded from an outside faucet with only a small portion being discarded through indoor faucets. If discharged into the septic tank, this highly chlorinated water could cause problems with bacterial colonies necessary for waste breakdown. For complete directions on shock chlorinating your well, visit http://extension.uga.edu/publications/detail.html?number=C858-4 .

Finally, 1-2 weeks after the shock chlorination treatment, have the water tested by a qualified lab to ensure that there is no microbial contamination. Until the lab report confirms the water is safe, boil water that is used for drinking, cooking, and brushing teeth.

In north Georgia, well owners should also periodically test for the presence of uranium and radon in their water. Wells located above the fall line are typically drilled into granitic bedrock. Uranium is naturally present in granite and can be present in the water of wells deeper than 100 feet. Uranium decays into radon gas. Radon ingested through well water can increase risk of stomach cancer, but of more concern is that radon in water can be released as gas into homes through showering and washing dishes and clothes. Radon gas is the second leading cause of lung cancer in the U.S., trailing only tobacco smoke. Radon can also seep into homes through the building foundation. Radon is odorless, colorless, and tasteless. UGA labs offer radon testing for well water and household air.

Fortunately, filtration and mitigation systems can remove radon from well water and granite soil beneath foundations before it enters your home. For information on testing well water or testing for radon in your home, contact UGA Extension Forsyth County at 770-887-2418 or Forsyth.extension@uga.edu.

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