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Flooded Private Water Supply

What to do if your private water well has flooded

​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​What can cause my well water to be unsafe?

Your water might be contaminated (unsafe to use) with harmful bacteria or chemicals if:

  • your water well has flooded
  • surface water got into the wellhead (the part of the well you can see above ground) and down into the well casing (material that supports the sides of the well)

Wells in pits or basements can also flood or be contaminated. 

When flooding happens, you need to have your well checked by a licensed water-well contractor. Even if your well looks fine, bacteria and chemicals can still get in.

If my water well has flooded, can I use the water?

If your well has flooded, don’t use the water to drink, cook, or bathe. Use a different​ safe water source instead, such as municipal truck-fill, bottled water, or a neighbour’s well that isn’t flooded. If this isn’t possible, boil your water for 1 minute in a rolling boil to kill harmful bacteria before you use it. Learn more about boiling water to kill bacteria. If your well is contaminated with chemicals, boiling won’t help to make the water safe.

Don't use the water until a licensed water-well contractor has checked your well and the floodwater has been flushed or purged from the casing, shock chlorinated​, and tested.

      What do I need to do to the well and pump?

      Floodwaters can carry waste (such as wood, rocks, and metal) that can damage the well casing, electrical parts, and the pump.

      When the floodwaters have gone down, call a licensed water-well contractor to check your well system. The pump (including valves and gears) might need to be cleaned to remove any soil or sand.

      Don’t turn on the pump after a flood until a qualified electrician or a licensed water-well contractor checks the wiring system. You could damage the well and pump or even get electrocuted (harmed by electric shock).

      Do I need to have my well and plumbing disinfected after flooding?

      After flooding, your well and the whole plumbing system connected to it need to be shock chlorinated. This is a way to kill harmful bacteria.

      Do I need to have my well water tested?

      Before you use your well again after it has flooded, have the water tested for bacteria​

      You can get sample bottles and testing instructions from an Alberta Health Services Environmental Public Health​ office. After testing, they will tell you if your water is safe to use. Learn more about drinking water bacteria test results.

      If you think your well has been contaminated with chemicals, contact Environmental Public Health​ for testing.

      How do I protect my well from flooding again?

      When the flood is over and your well is safe again, check with a licensed water-well contractor or Environmental Public Health to learn how to protect your well from future floods. This may include:

      • extending your well casing
      • installing a flood-proof cap with an extended vent
      • moving your well
      • upgrading pit wells​​


Current as of: May 17, 2024

Author: Safe Healthy Environments, Alberta Health Services