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Indiana Well-Water Risks After a Flood

Do you know how flooding can affect your drinking water quality? Find out how Indiana wells have been contaminated by flooding and how you can protect yourself.

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Indiana has about 400,00 wells throughout the state supplying water to residents. Simultaneously, about 13 percent of properties in the state are at risk of flooding. 

What happens when flooding occurs near private drinking wells? Let’s break down the risks of water contamination and what you can do to protect your water quality. 


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What Type of Contaminants Are in Floodwaters?

During a flood, the water will be contaminated by anything it encounters. So if the flooding near your home includes agricultural runoff, there could be pesticides in the floodwater. Similarly, flooding could be contaminated by industrial waste, chemicals, car fluids, and more. There is an especially high risk of floodwaters containing sewage from septic systems or sewage treatment plants. This makes it very likely that floodwaters will contain bacteria such as E.coli or coliform. 

The toxins and contaminants in your floodwaters will depend on what infrastructure is near you. However, the risks are so high that the CDC recommends not having direct contact with floodwaters, and if you do, use soap and clean water to wash exposed skin as soon as possible. Contact with floodwaters can cause rashes, wound infections, vomiting, gastrointestinal illnesses, and other serious health risks. 

Why Is Flooding a Risk for Well Water?

Water easily mixes with itself, and if floodwaters come in contact with your well head, contaminants from the flood will likely leach into your drinking water. Even watertight well caps may not be enough to fully protect your drinking water from bacteria, pathogens, and contaminants. 

Even more concerning is that floodwater doesn’t even need to come in direct contact with your well for it to contaminate your drinking water. Groundwater is also moving underground below the surface of the soil. As nearby floodwaters begin to saturate the soil, the groundwater could become contaminated. Underground spread could cause these contaminants to leach into your well if the well reaches the groundwater tables below. 

How Has Flooding Affected Well Water In Indiana?

One of the most notable Indiana floods in recent history was the Midwestern flooding of 2019. Even though the state was spared the worst damage compared to the flooding that occurred in other Midwestern states, many wells in Indiana were still contaminated. 

A report from the National Ground Water Association (NGWA) estimates that the 2019 flooding potentially contaminated 25,257 wells in Indiana. Throughout the Midwest, more than one million wells were affected across the 300 counties where flooding occurred. 

How to Disinfect Your Well Water After a Flood

Disinfecting your well is just one of the many steps to take after a flood. If you think your well may have been contaminated by flooding, follow all precautions from health agencies. Owners of private wells are independently responsible for their safety. Use the eight steps below to help restore your well water quality after a flood.

1. Test your well.

The only way to be certain about your water quality is to get the well tested. Indiana’s Well Water Quality resources offer helpful well testing information including a list of state-certified laboratories and how to interpret your results. Additional help is available via EPA’s Safe Drinking Water Hotline at 1-800-426-4791.

2. Clear out any sediment. 

When you’re ready to disinfect your well, begin the process by using an outside water line to flush out any sediment. Run the water from a hose or spigot until it becomes clear. 

3. Shock well with bleach. 

Adding bleach to your well can kill any bacteria that’s in the water or your pipes. Follow the manufacturer’s guidelines to remove the well cover and add the recommended amount of bleach to the well casing. Mix the bleach into the water by using an outdoor hose to add water to the well. Continue adding water until you smell bleach coming out of the hose.

4. Populate the lines, wait, and flush system.

To distribute the bleached well water through your house, run the cold water on each faucet in your home until you smell bleach, and then turn off the water. Remember to do both indoor and outdoor faucets. Wait six to 24 hours without using the water to allow the bleach to kill any germs. Afterward, use an outdoor hose to run the water until you no longer smell bleach. Flush any remaining bleach from the system by running the water on each faucet.

5. Re-test water.

About seven to 10 days after disinfection, re-test your well water for bacteria. Testing too soon after shocking the well can give you a false negative because small amounts of bacteria could be lurking in your pipes and repopulating. Remember that because contamination can move through the area’s groundwater, it’s useful to take a long-range view of water quality after a flood and test your water every few months.

6. Don’t use septic systems immediately after a flood.

Septic systems rely on dry soil, and after a flood, using your septic system can cause sewage to back up into your basement or crawl space, bubble out of the ground, or leach into your well water. Follow the recommendation of a plumber or safety inspection about when your plumbing is safe to use.

7. Drink bottled water until you are certain water is free of contaminants.

Until you know that your well water is safe, don’t use it. Contaminated well water can have serious health consequences, and after a flood, you’ll likely need to spend your energy on flood cleanup, mold remediation, foundation repairs, installing a sump pump, or improving drainage.

8. Get a professional foundation inspection to identify hidden damage.

Just as the water below the ground could be affecting your drinking water, the soil below your home could be affecting its structural stability. Foundation experts at Indiana Foundation Service can use signs of foundation damage to decipher what’s happening to the foundation below your home. If foundation damage after a flood is left unresolved, a process called differential settlement could cause your home to tilt, bow, or crack. 

Learn if flooding affected your home with a free inspection from Indiana Foundation Service.

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