The Alberta Centre for Toxicology tests drinking water to make sure it’s safe to drink. They use the
Guidelines for Canadian Drinking Water Quality set by Health Canada to report levels of trace metals in drinking water that can be harmful to your health. To understand your drinking water trace metals analysis results, use the information below.
Depending on the metal, the guidelines that are used to test your water can be based on health and safety (maximum acceptable concentration), effects like taste and smell (aesthetic objective), or impacts on water systems (operational guidance values).
Maximum acceptable concentration (MAC) is the highest amount of a metal in drinking water that is safe for a person to drink. This value is set to protect an average person from getting sick based on the average amount of water we drink.
Aesthetic objective (AO) looks at metals that can change the taste, smell, and look of your drinking water. The AO is used to decide if people will use or drink the water.
Operational guidelines (OG) are followed when a metal in the water may affect water treatment, damage pipes, or damage plumbing fixtures. OG values are meant for large water treatment systems and do not normally apply to private well water supplies.
Drinking water test results
If your water test shows high levels of any of the following metals, contact Alberta Health Services
Environmental Public Health. They can give you information about treatment devices for your home water supply.
Talk to your doctor if you have questions about metals in your drinking water and if they could affect your heath.
Aluminum
Guideline:
MAC: 2.9 mg/L
OG: 0.05 mg/L (for treatment systems that use aluminum flocculation)
OG: 0.1 or 0.2 mg/L (for other treatment types)
How it can get into water:
- Aluminum can get into well water from bentonite clay. Bentonite clay is used to seal the space between the well's drill hole and casing (annular seal).
- New wells that are not properly flushed may have high concentrations of bentonite clay and high levels of aluminum. Pressure tanks or sites that have not been purged or flushed since the construction of the well may also have high levels of bentonite clay and aluminum.
- Aluminum is found naturally in ground and surface water, but it is more common in surface water.
- Acidic soil (having a pH below 6.5) can lead to higher amounts of aluminum in water.
What you need to know:
Studies in animals and humans have found that high levels of aluminum can cause problems with the nervous system.
Antimony
Guideline:
MAC: 0.006 mg/L
How it can get into water:
- natural weathering (erosion) of rocks
- runoff (water that flows over soil and gets into a water supply)
- water used for mining and manufacturing
- plumbing fixtures with antimony
What you need to know:
Antimony levels higher than the MAC may cause small changes in organs, including the thymus, kidney, liver, spleen, and thyroid.
Arsenic
Guideline:
MAC: 0.01 mg/L
How it can get into water:
- natural weathering (erosion) of rocks
- runoff (water that flows over soil and gets into a water supply)
- mining and manufacturing (especially glass and electronics) wastewater
- air pollution
What you need to know:
Arsenic levels should be kept as low as reasonably achievable. Drinking water that has arsenic levels above the MAC may increase your risk of:
- arsenic poisoning, which includes symptoms such as pain, vomiting, diarrhea, and nerve problems
- lung, bladder, liver, and skin cancer
Learn more:
Is there arsenic in my drinking water?
Barium
Guideline:
MAC: 2 mg/L
How it can get into water:
- Barium can be found naturally in the water.
- Barium can get into untreated groundwater from runoff (water that flows over soil and gets into a water supply) or contact with manufacturing waste.
What you need to know:
Barium levels above the MAC may increase your risk of getting high blood pressure and heart disease.
Boron
Guideline:
MAC: 5 mg/L
How it can get into water:
Boron is found naturally in soil. It gets into groundwater from:
- weathering (erosion) of rock
- soil erosion
- manufacturing waste and wastewater
What you need to know:
- People mostly get boron through food.
- Drinking water that has boron levels above the MAC may increase your risk of reproductive problems.
Learn more:
Is there boron in my drinking water?
Cadmium
Guideline:
MAC: 0.007 mg/L
How it can get into water:
- plumbing systems that have cadmium in them (such as galvanized or polyethylene pipes)
- solder (metal that is used to bind other pieces of metal together)
- industrial and city or town (municipal) waste
What you need to know:
Cadmium levels above the MAC may increase your risk of kidney damage. It can also soften your bones.
Chromium 6 (VI)
Guideline:
MAC: 0.05 mg/L
How it can get into water:
- industrial waste
- water cooler systems that use chromium to prevent rust
- runoff (water that flows over soil and gets into a water supply)
What you need to know:
- Drinking water is tested for chromium 6 (VI).
- Chromium 6 can cause lung cancer or damage to other organs.
- We need chromium 3 (III) to stay healthy so it’s not included in drinking water testing.
Learn more:
Is there chromium in my drinking water?
Copper
Guideline:
MAC: 2 mg/L
AO: less than 1 mg/L
How it can get into water:
- industrial waste
- water systems that use copper piping
What you need to know:
We need a small amount of copper in our diets to stay healthy. Drinking water that has copper levels higher than the MAC can cause:
- nausea, vomiting, and diarrhea
- pain
- kidney problems (if you drink it over a long time)
Lead
Guideline:
MAC: 0.005 mg/L
How it can get into water:
- lead pipes used in older plumbing systems (commonly used before 1945, but most lead pipes have been replaced)
- solder (metal that is used to stick other pieces of metal together)
- unplasticized polyvinyl chloride (uPVC) pipes
- landfill runoff (water that flows over soil and gets into a water supply)
- industrial and city or town (municipal) wastewater
- storm water
In Alberta, high levels of lead in drinking water usually comes from solder or lead pipes.
What you need to know:
Lead levels should be kept as low as reasonably achievable. Higher levels of lead in drinking water can cause:
- development problems in children under 6 years of age
- development problems in unborn babies
- learning and memory problems
- kidney problems
- stomach and lung cancer (if you drink it over a long time)
Manganese
Guideline:
MAC: 0.12mg/L
AO: less than 0.02 mg/L
How it can get into water:
Manganese is common in soil, rocks, surface water, and groundwater. In Alberta, it is common at high levels in groundwater and surface water. Manganese can get into water from:
- weathering (erosion) of rock and soil
- landfill runoff (water that flows over soil and gets into a water supply)
- manufacturing waste and wastewater
What you need to know:
Manganese can:
- stain plumbing fixtures and laundry
- give drinking water a bad taste
- cause bacteria to grow in pipes
- form coatings on pipes, which can come off and look like black liquid or specks in the water
We need a small amount of manganese in our diets to stay healthy. But drinking water high in manganese can lead to:
- learning, memory, and behavioural problems
- having trouble paying attention (concentrating)
- movement problems
You are at the highest risk of developing these health problems if you:
- are very young
- are pregnant
- are older
- have liver disease
Babies also have a high risk of developing these health problems if they drink formula that is made with water with high levels of manganese.
Mercury
Guideline:
MAC: 0.001mg/L
How it can get into water:
Mercury is found naturally in soil, water, air, plants, and animals. Mercury can get into water from:
- natural weathering (erosion) of rocks
- industrial waste (effluents)
- water used for mining and manufacturing
- pesticides (things used to kill or control weeds, insects, and other pests)
What you need to know:
- The amount of mercury in drinking water is usually below the MAC.
- Canadians are exposed to mercury mostly from food, especially those who eat a lot of fish and seafood.
- Mercury levels above the MAC may cause nerve problems that can’t be cured.
Selenium
Guideline:
MAC: 0.05 mg/L
How it can get into water:
- Higher levels of selenium can be found in groundwater in Alberta.
- Selenium gets into an untreated water supply from:
- petroleum refineries
- mine and industrial waste
- natural breakdown of rock and soil
- Selenium may also be found in unleaded brass, which is used to replace lead.
What you need to know:
We need a small amount of selenium to stay healthy. We get most selenium from food. Eating food or drinking water with high levels of selenium can cause:
- hair loss
- tooth decay
- weak nails
- numbness and tingling of your arms and legs
- muscle weakness
Learn more:
Is there selenium in my drinking water?
Strontium
Guideline:
MAC: 7 mg/L
How it can get into water:
- natural weathering (erosion) of rocks
- runoff from soil (water that flows over soil and gets into a water supply)
- water used for mining and manufacturing
What you need to know:
- Strontium can replace calcium in bones.
- Strontium levels above the MAC may raise the risk of rickets, which is a bone disorder that may:
- weaken or soften the bones
- slow or stop (stunt) growth
- cause bone deformities
- The risk is highest for babies because their bones are growing so quickly.
Uranium
Guideline:
MAC: 0.02 mg/L
How it can get into water:
- Uranium is found naturally in some types of soil and rocks, like sandstone, shale, and granite bedrock.
- Uranium may be found in well water when the well is drilled in bedrock that has uranium. Wells that are shallow (dug or bored wells) and surface water supplies usually have less uranium.
- Low levels of uranium may also be found in food, water, and air.
What you need to know:
Drinking water with higher levels of uranium over a long time can cause kidney problems.
Learn more:
Is there uranium in my drinking water?
Zinc
Guideline:
AO: 5 mg/L or less
How it can get into water:
- weathering (erosion) of rock and soil
- burning fuel
- using pesticides (things used to kill or control weeds, insects, and other pests)
- manufacturing waste from industries that make things from iron, steel, copper, and nickel
- zinc coating on galvanized pipe
- zinc parts in hot water tanks
- brass fittings
What you need to know:
- Water with zinc levels higher than the AO will look cloudy or milky. It will have a greasy film when boiled.
- Health Canada has not found any health concerns related to drinking water with zinc.
- If your drinking water supply comes from a system that uses galvanized pipes, run your tap for 1 minute before drinking the water .
The following metals aren’t included in the
Guidelines for Canadian Drinking Water Quality.
- beryllium
- cobalt
- molybdenum
- nickel
- silver
- thallium
- titanium
- vanadium
At this time, Health Canada has not found that these metals are related to any health concerns. Alberta Health Services collects information about these trace metal levels to better understand if they get into our drinking water from natural causes or from industrial activity.
