Well Water After a Hurricane or Flood: Test, Disinfect, Retest

If a hurricane or flood reached your well, do not drink the water until the well has been disinfected and the water has tested clean. That is the guidance from CDC and EPA, and it applies even if the water looks and tastes normal. Floodwater can carry bacteria, sewage, and chemicals into a well, and you cannot see or smell most of them.

Well Water After a Hurricane or Flood: What to Do First

• •Stop using the water for drinking, cooking, brushing teeth, and baby formula. Use bottled water or boiled water (rolling boil for 1 minute, per CDC).
• •Turn off power to the well pump if the wellhead or wiring was underwater, and have it checked before turning it on.
• •Look at the well. Damage, a missing cap, or standing water around the wellhead are warning signs.
• •Call a licensed well contractor if the well was submerged or damaged.

Step 1: Disinfect

The usual method is shock chlorination: household bleach is added to the well, circulated through the plumbing, left to sit, and then flushed out. The amount depends on your well's depth and diameter, so use the instructions from CDC, EPA, or your county health department, or hire a licensed contractor. Be careful with bleach and keep it out of your septic system beyond what the instructions allow.

Step 2: Test

After disinfecting and flushing, collect a sample with the bottle and instructions from a certified lab or your county health department. The standard test is for total coliform and E. coli bacteria. University extension programs, including UF/IFAS in Florida, publish guidance on flooded wells and where to get testing.

Step 3: Retest

One clean result is good news, not the end. Follow your lab's or health department's advice on retesting, since contamination can show up later. If a sample shows bacteria, disinfect again and test again.

After the Water Is Safe

Once your well has a clean test, we can help with the other things floods stir up: sediment, iron, sulfur smell, and hardness. RainSoft of the Wiregrass offers a free in-home water test and treatment options for private wells, including the EC4 OxyTech for iron and sulfur. A water-treatment system does not replace disinfecting and testing a flooded well.