Testing Your Well Water

According to the Canadian Water and Wastewater Association, more than 14-15% of all Canadians rely on private wells. Even more people rely on private wells in smaller rural communities like those in Tulameen, Coalmont, Missezula Lake and Bankeir. I receive many questions from clients asking about the drinking water source, how it works, if it's safe to drink and how to test it. Much of the information found in this guide is referenced from CARO Analytical Laboratory Services and will provide answers to some of the most common questions regarding well water. You may visit www.caro.ca for more information.

How Often Should I Test My Drinking Water?
As a homeowner, the Canadian guidelines recommend that you test your well water at least once a year for total coliforms and E.coli. Spring, once snow melt and surface runoff have finished, is a good time for testing. If you test during these conditions, it is likely to be safe the rest of the year.  Test regularly even if your water seems fine, because you can’t always taste, smell or see bacteria or other contaminants. Do not rely on your neighbour’s test results – wells that are only a short distance apart can have different water quality. Any new source of water must be tested before consumption to be sure that the water is safe (new subdivisions, properties without an existing well). 

Common contaminants in drinking water

Total coliforms and E.coli can be present as a result of nearby septic systems, sewage discharges, and domestic or wild animal life. Heavy metals naturally occur in groundwater in many regions. However, a high concentration of metals in your drinking water can be poisonous. Uranium and Arsenic are common metals of concern in the BC interior. Lead and Copper can be concerns in homes with brass fixtures, lead solders and fittings, or copper pipes. Agricultural contamination from nearby farming activity may include nitrogen compounds. General drinking water parameters relate to the physical characteristics of your water.

How do I sample for bacterial contamination

The following directions apply to routine sampling for total coliforms and E.coli. It is important to follow these steps or your sample may be contaminated leading to false results. Use the water sample bottle provided by your testing laboratory to collect your sample. A preservative that is in the bottle is intended to be there.

  • Remove the screen (aerator) from the end of the cold water tap or faucet.
  • Sterilize the end of the tap, faucet or spigot. If there are no plastic components, this can be done by flaming the end of the tap with a lighter. Alternatively, wash it with a strong disinfectant solution of 10 ml (two tsp) of unscented, detergent-free household bleach added to 1 L (four cups) of water.
  • Allow the tap, faucet or spigot to run with cold water for three to five minutes before taking the sample.
  • Cut the flow of water to a gentle stream to avoid splashing or overfilling the sample bottle.
  • Remove the cap from the sample bottle by carefully breaking the protective seal. Do not use a sample bottle if the seal is broken or if you cannot see the preservative (white residue). Do not rinse the bottle – it contains a preservative needed for the test.
  • Hold the cap in one hand while you fill the bottle. Do not lay the cap down or touch the inside of the cap. Keep fingers below the threaded rim of the bottle.
  • Fill the bottle to the level indicated, or as directed by the laboratory. Replace the cap and tighten.
  • Label the bottle and identify the location (e.g., kitchen tap – untreated well water) and the date and time the sample was taken.
  • Keep the sample bottle sealed and in a cool place such as a refrigerator. 
  • Fill out the submission form provided by the laboratory. Make sure to indicate where the sample was taken, your address and contact information (include a cell number or email address for emergency notification) on the form.
  • Pack the sample in a cooler with an ice pack and packing paper to keep it cool and secure until it gets to the laboratory. If you’re shipping by bus or courier, put the completed sample submission form in a sealable plastic bag, seal it and put it inside the cooler.
  • Drop off the sample and completed form at the laboratory or at the bus or courier location for transport.
NOTE: Water samples must be kept cool. Water samples that get too warm, freeze or sit too long will give incorrect results. Samples must arrive at the laboratory within 24 hours of collection.

The government of British Columbia mentions how microbiological testing is the highest priority. This is especially the case for homeowners with a well or a private drinking water source. 

Total Coliforms, E.coli and Fecal Coliforms: Exists naturally in soil, water, and vegetation. Nearby septic systems, sewage discharges, and domestic or wild animal life can promote coliform growth. E.coli is considered the type of coliform that is the best indicator of fecal contamination with the possibility to carry pathogens. The total coliform bacteria test is a primary indicator of “potability”, or suitability for consumption, of drinking water.

Heterotrophic Plate Count (HPC): This test measures colony formation on culture media of heterotrophic bacteria in drinking water. Can be used to measure the overall bacteriological quality of drinking water in public, semi-public and private water systems. High levels of HPC bacteria in a distribution or plumbing system result from bacteria regrowth where bacteria that resisted treatment can grow.

Iron-Related Bacteria (IRB): Iron-related bacteria naturally occur in soil and water. These bacteria combine iron and manganese with oxygen to form deposits of “rust” and slimy build up. Taste and odor problems and “red water” are common symptoms of problems due to iron-related bacteria.

Sulphur Reducing Bacteria (SRB): Sulphur-reducing bacteria get their energy by reducing elemental sulphur to hydrogen sulfide. They also oxidize acetate or other organic compounds. These bacteria can cause corrosion, clogging, fouling of the water, and increased hygiene risks. 

Background Growth: Usually seen as yellow colonies. An indicator of a general bacterial population in a sample. This can lead to many other health concerns. Any microbiological test can determine if there is bacterial background growth.


Some metals are essential for life and are naturally availble in our food, soil, and water. However, our drinking water can contain a poisonous concentration of metals. 

Lead: Lead is a neurotoxin, a carcinogen, and a heavy metal that bioaccumulates in the body. Children and pregnant mothers are the most vulnerable since even extremely low levels of exposure are toxic and very difficult to eliminate. Lead gets into the water most commonly from the corrosion of plumbing parts.

Copper: Even though copper poisoning from water is rare, it does happen. People who drink from well water are at a higher risk for copper poisoning because their water isn’t as regulated as a public system. Copper contamination usually occurs from corrosion in the water delivery system. Copper piping and fittings are widely used in household plumbing. The longer water has stood idle in the pipes, the more copper it is likely to have absorbed. Newer homes with copper pipes are more likely to have this problem because these pipes haven’t developed a coating to help insulate the water passing through. Short-term exposure to high levels of copper can cause gastrointestinal distress. Long-term exposure and severe cases of copper poisoning can cause anemia and disrupt liver and kidney functions.

Arsenic: An odourless and tasteless semimetal that occurs naturally in the earth and the seas. Consumption of food and water are the major sources of arsenic exposure. Exposure can come from industrial sources as well. An arsenic test is common for people using a private water source. This is because wells are more susceptible to pollutants from weathering and surface arsenic-related pollutants are easily distributed by rain and snow weathering the ground.

Mercury: A naturally occurring element found in air, water and soil. There are several ways humans can be exposed to it and the EPA describe it very well in this article. Nearly all methylmercury exposures in the U.S. occur through eating fish and shellfish that contain higher levels of methylmercury. Other than Mercury being highly toxic, there are many signs and symptoms that you may be a victim of mercury poisoning.

Common General Parameters

Generally, these are for the physical characteristics of the water.

Turbidity: Measures the cloudiness of water. Turbidity assesses suspended particulate in the water. These particles, or suspended solids, can contain bacteria and viruses. Some particles are large enough and heavy enough to eventually settle to the bottom of a container if the sample is left still. Health risks may increase as turbidity rises.

Conductivity: Impurities in the water can affect the water’s ability to conduct electricity. Pure, distilled water is a poor conductor of electricity. When salts and other inorganic chemicals dissolve in water, they break into tiny, electrically charged particles called ions. Ions increase the water’s ability to conduct electricity. Common ions in water that conduct electrical current well include sodium, chloride, calcium, and magnesium. 

Total Dissolved Solids: Water is a good solvent and picks up substances easily. Dissolved solids refer to any minerals, salts, metals, cations or anions dissolved in water. Total dissolved solids (TDS) comprises of inorganic salts and some small amount of organic matter that dissolve in the water. TDS in drinking water originates from natural sources, sewage, urban runoff, industrial wastewater, and chemicals used in the water treatment process. 

Temperature: A key factor of water quality. The temperature of the released water can affect downstream habitants. Temperature affects the dissolved oxygen levels in water, the rate of photosynthesis, metabolic rates of organisms, etc. Aquatic organisms depend on particular temperature ranges for their health. Each species of organism thrives in a specific temperature range, and many animals use temperature as a signal for when to reproduce and when to migrate. If there is an abnormality in temperature this can disrupt the balance of aquatic ecosystems with devastating effect. Water temperature also impacts water density; differences in water temperature and density can cause stratification.

Anions: These compounds include Chloride, Fluoride, Nitrate, Nitrite and Sulfate. Each of these compounds have different symptoms and affects to our body. If enough organic and inorganic salts enter into the water system, they make water toxic and poisonous to drink.

Cyanide: One of the most commonly used chemicals in the world. Its widespread use and highly reactive nature increases the potential for cyanide to enter the environment. Mining clients and environmental consultants are concerned with cyanide due to manufacturing, combustion, or other sources. People can be exposed by breathing air, drinking water, eating food, or touching soil that contains cyanide. Survivors of serious cyanide poisoning may develop heart, brain and nerve damage.

Sulfide: Two forms of sulphur are commonly found in drinking water: sulphate and hydrogen sulfide. Sulfate minerals can cause scale to build up in water pipes similar to other minerals and may be associated with a bitter taste in water that can have a laxative effect on humans and young livestock. Hydrogen Sulfide gas produces a “rotten egg” or “sulphur water” odour and taste in the water. The nuisance associated with hydrogen sulfide includes its corrosiveness to metals such as iron, steel, copper, and brass. It can tarnish silverware and discolor copper and brass utensils. Also, sulfide can cause yellow or black stains on kitchen and bathroom fixtures.

Hardness: Hardness in water is caused by dissolved calcium, magnesium, and mineral ions which makes a significant concentration. Hardness in the water can cause scaling in pipes and water heaters, which can cause energy loss in your home’s water system, such as boilers, cooling systems, plumbing, and heating appliances. This causes excessive soap consumption and scaling. 


Chemicals can enter waterways from an industrial site and also the movement of rainwater over land picks up pollutants such as fertilizers, insecticides and make water toxic. 

Chemical Oxygen Demand: Tests for the capacity of water to consume oxygen during decomposition of organic matter and the oxidation of inorganic chemicals such as ammonia and nitrite. COD measurements are commonly made on samples of wastewater or natural waters contaminated by domestic or industrial waste.

Biochemical Oxygen Demand: BOD is used as a gauge of wastewater treatment effectiveness. It tests for the amount of dissolved oxygen that must be present in a sample to allow microorganisms to decompose the organic material. The higher the BOD value, the greater amount of organic matter or “food” available for oxygen-consuming bacterias.

pH: Stands for the “power of hydrogen”. It measures how acidic/basic the water is. pH’s of less than 7 indicates acidity, where pH above 7 says its basic, or alkaline. Since pH can be affected by chemicals in the water, pH is an important indicator of water that is chemically changing. Pollution can change a water’s pH, which in turn can harm plants and animals that live in or depend on the water.

Alkalinity: Total Alkalinity is the measurement of the water’s ability to resist a change in pH. Measuring alkalinity is important for determining a river’s ability to neutralize acids. Also known as the water’s capacity to resist changes in pH that could make water more acidic. This is important for aquatic life because they function best in a pH from 6 to 9.

Nitrate: Usually introduced into groundwater by leaching of chemical fertilizers, animal manure, or groundwater pollution from septic or sewage discharge. The can be hard to detect. The health concern tied to nitrates is how it can harm infants by reducing their ability of blood transporting oxygen. The Government of BC recommends well owners to test for Nitrates in their well annually.

Pesticides: These include a large group of chemical agents that attempt to eliminate destructive biological forces in agriculture. For example; herbicides for killing plants, insecticides for killing insects, fungicides for killing fungus, and bactericides for killing bacteria. While these chemicals supposedly only target specific species, repeated use inevitably kills the microbial life that is beneficial to the soil system. Pesticides can contaminate soil, water, turf, and other vegetation. Also, pesticides can be toxic to a host of other organisms including birds, fish, beneficial insects, and non-target plants. The use of pesticides has been too effective to the point that it is causing considerable pollution to our environment. 

Fluoride: Fluoride occurs naturally in the environment and in groundwater. At low levels, fluoride helps clean teeth and reduce the chance of dental cavities, but at high concentrations of exposure, it can cause dental fluorosis: yellowing of teeth, pitting and alteration of tooth enamel. High fluoride levels are known in parts of the Okanagan and Shuswap regions of BC. It is common for well owners to be concerned about their water’s fluoride levels.

Corrosivity: Corrosion can impact your families health and damage your household piping and fixtures. Corrosion is an oxidation/reduction reaction between the water and metal surfaces. Having corrosive water in your plumbing system or private water system, it raises the chance toxic metals being present in your water. These metals include lead, copper, chromium, and zinc. Also, there are many aesthetic concerns tied to corrosivity. Water that is known to be corrosive tastes bitter, can stain laundry, and create greenish-blue stains around basins and drains.

Chlorine: Used to disinfect water for almost a century because of its incredible ability to kill bacteria and viruses in the water. In water, chlorine reacts to form hypochlorous acid and hypochlorites and could be potentially harmful if consumed. It is vital that you make sure water is tested correctly and that there are no short-term or long-term risks present in their water before suggesting treatment or pretreatment.

Trihalomethanes (THM): Byproduct of chlorination. THMs occur when chlorine reacts with organic matter in water. According to The Government of Canada, animals exposed to very high levels of THM have increased the risk of cancer. THMs can be easily absorbed by the body when: water containing high levels comes in contact with the skin, if they are consumed in food prepared in water, or if they’re inhaled during showering or bathing.

Haloacetic Acids (HAA): Byproduct of chlorination. Excessive levels can cause nervous system and liver effects. Exposure to a high concentration of HAA over a short period of time in drinking water can cause severe irritation to the skin. The Environmental Protection Agency has classified the acid as a Group 2B cancer classification, which means it may cause cancer in humans.

Aesthetic concerns: Aestheic Concerns are one of the two main classifications for water contamination. This relates to the way it looks, tastes, and smells. CARO's aesthetics concerns package covers Colour, Transmissivity, Ammonia, Sulfide, and Total Organic Carbon.

Disinfection by-products: Our Disinfection By-Products package, tests for Chlorate, Chlorite (total and free), Trihalomethane (THM), and Haloacetic Acids (HAA). As a residential pool or hot tub/spa owner, it is your responsibility to regularly check chlorine concentration to help protect yourself, family and your friends from recreational water illnesses .

Water Testing Packages:

Century 21 Horizon recommends a professional testing laboratory to complete any water test. We will generally use CARO Analytical Services in Kelowna to complete our test samples. CARO is an industry leading Canadian based, full service environmental laboratory that provides testing services to public and private clients throughout the world. In operation for over 30 years, CARO specializes in providing chemical analysis, microbiological analysis, food analysis, and contaminated site testing of soil vapour, drinking water, wastewater, water, vegetation, tissue, soil and sediments. Below is a list of common water testing packages offered by CARO. There are other testing options offered to your specific needs.

1. Basic Bacteria Test

This indicates the influence of surface water, septic and animal fecal matter. This also meets the definition of potability for most mortgages.
Includes: Total Coliforms, E.coli
Approximate Cost: $99.00

2. Basic Drinking Water Package 

This tests for most common concerns for potability without microbiology. 
Includes: Alkalinity, Aluminum, Antimony, Arsenic, Barium, Boron, Cadmium, Calcium, Chloride, Chromium, Copper, Conductivity, Cyanide, Fluoride, Hardness (total), Iron, Lead, Magnesium, Manganese, Mercury, Nitrate, Nitrite, pH, Potassium, Selenium, Sodium, Sulfate, Total Dissolved Solids, Turbidity, Uranium, Zinc $225.00 ORDER NOW
Aesthetic Concerns Aesthetic effects (e.g. taste, odour) are taken into account when these play a role in determining whether consumers will consider the water drinkable. Colour, Transmissivity, Ammonia, Sulfide, Total Organic Carbon Approximate Cost: $125.00

3. Essential Drinking Water Test Kit (Comprehensive)

Parameters frequently required for drinking water approval. This meets requirements of Environmental Health Officers in North, Central and & South Okanagan.
Includes: Total Coliforms, E. Coli, Alkalinity, Aluminum, Antimony, Arsenic, Barium, Boron, Cadmium, Calcium, Chloride, Chromium, Copper, Conductivity, Cyanide, Fluoride, Hardness (total), Iron, Lead, Magnesium, Manganese, Mercury, Nitrate, Nitrite, pH, Potassium, Selenium, Sodium, Sulfate, Total Dissolved Solids, Turbidity, Uranium, Zinc
Approximate Cost: $324.00

4. COMPLETE Potability Drinking Water Test Kit

Everything in the Comprehensive drinking water list plus everything else in the CDWQG. If you want complete peace of mind by testing for all parameters that health Canada has identified as potential concerns in water, this package is for you.
Includes: everything listed in above packages and basically everything in the Canadian Drinking Water Quality Guidelines.
Approximate Cost: $1999.00

Laboratory Contact Information

Kelowna, British Columbia
#102 – 3677 Highway 97N
Kelowna, BC, V1X 5C3, Canada
Phone: (250) 765-9646
Toll Free: 1 (888) 311-8846 Fax: (250) 765-3893
Email: Kelowna@caro.ca
After Hours Emergency: 1 (888) 311-8849