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Flooded Private Water Supply

Testing your water after your well has flooded

​​​​​​​​​​​​​​​​​​How can flooding affect my well water?

Heavy rain and flooding can cause surface water to enter your private water well. This means there is a risk of harmful germs like bacteria getting in and making the water unsafe (contaminated).

When should I test my water to make sure it’s safe?

After the heavy rain stops and the floodwaters go down, send a water sample to a lab to test for bacteria.

Is it safe to drink my well water while I’m waiting for my water test results?

Don’t drink untreated well water until you get your test results back. If you think your well is contaminated with floodwater, you should boil your water while you’re waiting for your results.

What lab tests well water in Alberta?

The Provincial Laboratory for Public Health (ProvLab) tests private drinking water systems. The ProvLab can’t test water for every type of harmful germ. It does 2 standard tests on water samples to check for bacteria.

What bacteria does ProvLab test for?

ProvLab can test your water for the following bacteria:

  • Total coliforms are a group of bacteria found everywhere (such as in soil, on plants, in lakes and rivers). They can get into your drinking water because of floodwater or well maintenance problems.
  • E. coli is a type of bacteria that people and some types of animals have in their bowels. If you have E. coli in your drinking water, the water is not safe. Your water has been contaminated by human or animal waste (stool).

What do my water test results mean?

If your first water sample results show no bacteria​, then send another sample 14 to 30 days later to make sure the water is still safe.

If your first water sample results show there are bacteria, then a public health inspector will call you. They may tell you to shock chlorinate your well.

Where can I learn more about water safety?

Visit Alberta Health Services Environmental Public Health​ to learn more about drinking water safety, including:

  • collecting a water sample for testing
  • picking up and dropping off water sample bo​ttles
  • understanding your water sample test results

Current as of: February 18, 2021

Author: Environmental Public Health, Alberta Health Services