Can Flood Water Contaminate Your Home's Well Water Supply?

Flood water can enter a well in several ways. If the well casing is cracked or the cap is not sealed, surface water can flow directly inside. Flooding can also saturate the ground around the well, pushing contaminated water through the soil into the aquifer.

Even a small amount of standing water near the wellhead can be a risk. The pressure from floodwater can force contaminants past seals that normally keep the well safe. The longer the flooding lasts, the higher the chance of contamination.

• Cracked or loose well casing
• Unsealed or damaged well cap
• Flooded well pit or basement
• Surface water pooling near the wellhead
• Soil saturation pushing water into the well

If your well area has been flooded, stop using the water for drinking, cooking, or brushing teeth right away. Use bottled water or another safe source until you know the well is clean. Boiling water is not enough to remove chemicals.

Check the wellhead for visible damage. If the cap is loose or the casing is cracked, do not turn on the pump. Contact a local well driller or pump installer to inspect the system before you restart it.

If tests show contamination, the well needs to be cleaned and disinfected. This usually involves flushing the system with a chlorine solution, letting it sit, and then pumping it out. A well professional can guide you through the process or do it for you.

After disinfection, test the water again to confirm it is safe. You may need to repeat the process if the first attempt does not clear the contamination. Protect the wellhead from future floods by raising it above ground level and sealing any openings.