Private Well Water Testing

Regular testing of your private well is important to make sure your water is safe for you and your family to drink. Bacteria such as E. coli can contaminate your well making it unsafe to drink. The risk is higher if you have animals in the area – especially on farms with livestock and other animals – but the bacteria can also occur naturally in the soil.


How often should the water be tested?

For testing, the TBDHU recommends:

  • Drilled Well - at least three times per year; once after the spring melt and then summer and fall
  • Dug Well - at least four times per year; one after the spring melt, and three more times during the summer and fall

Heavy rainfalls or flooding? Additional testing is recommended as there is a greater risk of surface water washing into your well (drilled or dug).


How do I get a kit?

Free bacterial testing is available for private well owners through Ontario’s Public Health Laboratory (the Lab), located at 336 South Syndicate Avenue. The Lab does not test for other contaminants, such as chemicals.

To have your water tested, it must be collected in a proper water collection kit.

You can get a kit from:

  • The TBDHU’s main office at 999 Balmoral Street in Thunder Bay
  • The Lab at 336 South Syndicate Avenue in Thunder Bay
  • Any TBDHU branch office in the district communities

When you pick up your kit, make sure it includes:

  • A water bottle with a barcode sticker on the side
  • A plastic bag containing a submission form for the Lab and a small card for your records called "WATER RESULTS BY TELEPHONE"
  • Check the lid of the bottle to make sure the tamper ring is not damaged – if it has snapped off, get another bottle.
  • Instructions for how to take a water sample correctly.


How is the sample collected?

Before you take a sample, complete the submission form. you must fill in all of the shaded areas or the water will not be tested. There is a checklist on the first page to help. Follow these steps to take the sample:

  1. Take the sample when you’re sure you can deliver it to the Thunder Bay Laboratory within 48 hours. However,  the sooner the better. Your water sample should not be left any longer as this can lead to inaccurate results.
  2. Take all attachments off your faucet, including aerators. If you can’t do this, take a sample from an inside tap with no aerator, like the bathtub. Do not take a sample from an outside faucet or the garden hose.
  3. Disinfect the end of the faucet spout with an alcohol swab or diluted bleach solution (1 part household bleach to 10 parts water) before running water to remove debris or bacteria. Do not use a flame because it can damage the faucet.
  4. Turn on the cold water and let it run for two to three minutes to remove standing water from your plumbing system.
  5. Look at the lid of the water bottle to make sure it hasn’t been snapped. If the tamper ring has been broken, use another collection kit. Do not touch the inside of the lid or place it down when you take it off the bottle.
  6. Fill the bottle to the level that is marked and close the lid tightly.
  7. Take off one of the barcodes from the bottle and stick it to the WATER RESULTS BY TELEPHONE card in the collection kit. This is your PIN information so you can get your results over the telephone through the Interactive Voice Response (IVR).  Keep this card so have what you need to use the IVR.
  8. Keep the sample cool (but not frozen) until it’s returned to the Thunder Bay Laboratory. Do not store samples in warm places like your car trunk.
  9. Bring the sample to the Thunder Bay Laboratory within 48 hours or it may not be tested. see back for a map.


An instructional video, produced by the Grey-Bruce Health Unit, is also helpful:

How do I get my results?

Results are usually ready within 2 to 4 business days after submitting. They are automatically mailed to the name and address on the form unless you check the box that shows you want to pick up the results at the Thunder Bay Laboratory with photo ID. Using the information from your WATER RESULTS BY TELEPHONE card, you can call toll-free at 1-877-723-3426 (TTY 1-866-828-2238). The service is available 24 hours a day, 7 days a week  What should I do if my well tests positive for contamination?


What should I do if my well tests positive for bacterial contamination?

  1. Stop drinking the water and find other sources such as bottled water or municipal water if it’s available.
  2. If you have to use the well water, bring it to a rolling boil for at least one minute before using it for drinking, making baby formula, juice, ice, cooking, brushing teeth, rinsing contact lenses and washing food or dishes. Keep boiled water in the fridge until you use it.
  3. Disinfect your well. Instructions for how to disinfect your well can be found by visiting Public Health Ontario's Well Disinfection Tool
  4. Call the TBDHU for help with carrying out the instructions you will get from the Lab. You can reach a public health inspector at (807) 625-5900 or toll-free at 1-888-294-6630, Monday through Friday from 8:30 am to 4:30 pm.


For Further Information

Call the Environmental Health program at (807) 625-5900

or toll-free at 1-888-294-6630

Last Updated: 25/04/2022