Well Water Testing

HealthLinkBC File Number: 
Last Updated: 
March 2018

Is my well water safe to drink?

If your drinking water comes from a private well, it should be tested by a lab to see if it is safe for you and your family to drink.

Unsafe drinking water can make you sick. Even if you are not sick right now, your well water may not be safe. Some contaminants found in well water can cause long-term health problems.

All water suppliers in B.C. are required to test their water regularly. This includes including small private systems, such as restaurants or trailer parks, cooperatively owned systems, such as strata properties, and larger municipal systems owned by local govern ents. Water samples are sent to qualified labs for testing.

If you own a private well, you need to have your own well water tested to determine if your water is safe to drink. Just because your neighbour's well has been tested and found to be safe, this does not mean yours is too. The safety of your well water depends on surface and underground geology, the depth and construction of the well, and other factors.

Be aware that tests will only tell you about the water quality on the day you test it. Well water quality can change over time. Weather, seasons, drought, floods or other events may cause contamination. You need to test your well water on a regular basis, and keep all testing results for future reference.

Why might my well water be unsafe?

Your well water may taste and look fine, however, there can be many harmful substances that you cannot taste, see or smell, such as bacteria and chemicals that could affect your health. These can enter well water both from the surface and ground, and can be from natural sources or human activities. For example, nearby farming and agricultural activities or septic systems, if built or maintained improperly, could lead to increased nitrates and fertilizers seeping into soil and contaminating your well water. Poor well maintenance may also cause contamination of your well water.

What do I test my well water for?

There are 2 categories of testing for well water:

  1. Bacteriological testing
  2. Chemical testing

Bacteriological Testing

Bacteriological testing should be done 2 or 3 times a year. Two common types of bacteria found in water are: Total Coliforms and E.coli.

Total Coliforms

Total Coliforms include bacteria found in soil, surface water, and the intestinal tracts of animals. Finding total coliforms in a well may not mean that the water is unsafe to drink, but does indicate:

  • The well may require improved sanitation or physical upgrades
  • The well may be subject to surface contamination

Escherichia coli (E. coli)

E. coli originates in the intestinal tracts of animals. The presence of E. coli in your well water may mean fecal matter has entered the well. Fecal organisms cause stomach and intestinal illnesses, including diarrhea and nausea, and may even lead to death. Babies, children, elderly or people with immune deficiencies or other illnesses may be affected more severely.

E. coli in your drinking water is an immediate health concern and the water is not safe to drink.

For more information, see the Ministry of Environment’s fact sheet on Total, Fecal & E. coli Bacteria in Groundwater www2.gov.bc.ca/assets/gov/environment/air-land-water/water/water-wells/coliform020715_fin2.pdf (PDF 179 KB).

Chemical Testing

Chemical testing should be done on a routine basis, typically at a minimum every 5 years. Chemicals commonly of concern in B.C. groundwater are: nitrates, fluoride and metals such as arsenic, lead, copper and manganese.


High levels of nitrates have been found in a number of wells throughout B.C. This usually occurs in areas where groundwater may be contaminated by surface activities such as agriculture or farming. For more information, see HealthLinkBC File #05a Nitrate in Well Water.


Since well water comes from underground, different metals in the soil and rock can leach into the water. Some metals, such as arsenic can have serious and long-term health effects if they are found in high amounts. Other metals such as lead and copper can also leach out of pipes and soldered joints. For some, but not all metals, you may notice taste, odor, or staining of fixtures.

Other chemicals

Chemicals found in well water can come from human activity and natural sources. Most naturally occurring chemicals are found in small quantities that are little or no risk to human health. For example, low levels of fluoride have dental benefits, but high levels can have a negative impact on the development of healthy bones and teeth in children. For more information see HealthLinkBC File #28 Water Fluoridation Facts.

If you live in an agricultural or farm area, you may also want to test for pesticides. If you live near a gas station, industrial area, or there is a history of chemical spills or known contaminants in your community consider testing for a broader combination of chemicals.

For more information, see the Safe Water Supply: Vital to Your Health report, available at your local Health Authority office or at www2.gov.bc.ca/assets/gov/environment/air-land-water/safe-water-supply-vital-health.pdf (PDF 183 KB).

How do I get my well water tested?

For information on where to get your well water tested or to report possible contaminants in your area, contact your Drinking Water Officer (DWO) through your health authority. Visit the Ministry of Health - Drinking Water Quality website for health authority contact information www2.gov.bc.ca/gov/content/environment/air-land-water/water/water-quality/drinking-water-quality/health-authority-contacts.

The DWO may advise you on where to find a lab that can test well water. The lab will send you the necessary sample bottles and instructions. Read the instructions carefully and follow them exactly. The lab (or your local health authority) may provide information to help you understand the test results and determine if there is a problem with the water.

What if the tests show possible contamination?

If the results are at or near the guidelines, immediate health concerns are unlikely, however long term treatment should be considered to remove contaminants. Anytime test results are well above the guideline limits, you should contact the DWO for advice.

Poor bacteriological test results are an immediate health concern. Where E. coli is found, you must treat your drinking water before drinking it, using it for food preparation, or brushing your teeth. For short term treatment options such as boiling water, see HealthLinkBC File #49b Disinfecting Drinking Water. You should investigate the source of all E. coli results and if they cannot be corrected, find a long term treatment solution for your water.

For more information on disinfecting your well, consult the DWO or see ‘Water Well Disinfection: Using the Simple Chlorination Method’ at www2.gov.bc.ca/assets/gov/environment/air-land-water/water/water-wells/bc_gov_5402_water_well_disinfection_webbrochure.pdf (PDF 3.42 MB).

Health Canada’s Guidelines for Canadian Drinking Water Quality recommend maximum acceptable concentrations for a wide range of possible contaminants in drinking water at www.canada.ca/en/health-canada/services/environmental-workplace-health/water-quality/drinking-water/canadian-drinking-water-guidelines.html.

What is long term treatment?

There are many types of water treatment devices that remove contaminants. Your local DWO can provide some general advice on your treatment options and a water treatment supply company can provide solutions for your specific water quality problem.

The final selection and costs of treatment devices and their maintenance, follow-up sampling, and ongoing testing are the responsibility of the private well owner.

For more information on well water, visit the Ministry of Environment – Water Protection & Sustainability Branch at www2.gov.bc.ca/gov/content/environment/air-land-water/water/groundwater-wells-aquifers or contact the DWO.

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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