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Water Testing

Understanding Your Drinking Water Chemical Test Results

​​​​​​​​​​​​​​​​The Alberta Centre for Toxicology tests drinking water to make sure it’s safe to drink. They use the Guidelines for Canadian Drinking Water​ set by Health Canada to report safe levels of substances in drinking water, including those that can be harmful to your health. To understand your drinking water test results, use the information below.

Some of the results are reported using maximum acceptable concentration and the aesthetic objective.

Maximum acceptable concentration (MAC) is the highest amount of a substance in drinking water that is safe for a person to drink. This value is set to protect an average person from a substance in drinking water, if they drink 1.5 litres of water each day over 70 years.

Aesthetic objective (AO) looks at the taste, odor, and appearance of drinking water. The AO is the level of a substance used to decide if people will use or drink the water.

If you have any questions about your dri​nking water test results, please contact a Public Health Inspector in your area.

Drinking water test results

Talk to your doctor if you have questions about substances in drinking water and if they could affect your heath.​

Result Guideline Information

7.0 to 10.5

  • pH is a measure of how acidic or how basic the water is. A pH of 7 is neutral (not acidic or basic).
  • A pH below 6.5 can cause rusting or corrosion (eating away) of metal in plumbing and parts of appliances such as washing machines, dishwashers, and water heaters. If metals from pipes such as lead, cadmium, zinc, or copper get into drinking water, it can lead to health problems.
  • As pH gets higher, you’re more likely to notice ​a build-up of minerals (called scaling) on cookware, plumbing, and appliance parts.

200 mg/L or less


  • Water with more than 200 mg/L of sodium tastes salty.
  • Water treated with a water softener may have a sodium level over 300 mg/L. This may not be safe if you follow a diet to limit sodium.
  • Talk to your doctor if you follow a diet that limits sodium to 1500 mg per day or less and have concerns about the level of sodium in your drinking water.
PotassiumNo guideline
  • Most drinking water is low in potassium and is not a concern for healthy people.
  • Water softeners using potassium chloride can cause high levels of potassium in drinking water. If you have health problems such as kidney disease, heart disease or diabetes, ask your doctor if you can drink water treated with a water softener.
CalciumNo guideline
  • Calcium is safe for healthy people and is normally found in food and drinking water.
  • Calcium makes water harder (see section on total hardness in water below).
  • Calcium levels higher than 200 mg/L may cause scaling on cookcare, plumbing and appliance parts.
MagnesiumNo guideline
  • Magnesium is safe for healthy people and is normally found in food and drinking water.
  • Magnesium makes water harder (see section on total hardness in water below). Levels higher than 150 mg/L may cause loose bowel movements (diarrhea) if people are not used to drinking it.
Total hardnessNo guideline

  • Total hardness is a measure of calcium, magnesium and other minerals that affect the hardness of water. These minerals can get into water as it moves through the ground.
  • Soft water causes corrosion and hard water causes scaling on pipes and appliances. When water is hard, you need to use more soap to wash things. Water softeners lower hardness, but raise sodium or potassium levels.
Hardness Level
soft0 to less than 60 mg/L
medium hard60 to more than 120 mg/L
hard120 to less than 180 mg/L
very hard180 mg/L or more

Total dissolved solids​​ (TDS)
500 mg/L or less
  • TDS is a measure of all minerals in water. A high TDS can cause scaling and change the way water tastes and smells. Water with a low amount of TDS may taste flat. A high TDS can also prevent water treatment devices from working properly.
  • Water with a TDS level over 1000 mg/L can have a different taste and smell and cause a lot of scaling.

0.3 mg/L or less


  • Iron levels above 0.3 mg/L can cause a reddish-brown stain on laundry, taps, and other plumbing fixtures. It can also make water taste like metal.
  • High iron levels can cause iron bacteria to grow on parts of water systems, wells, and plumbing. Adding chlorine to water through a process called shock chlorination can help control iron bacteria. This may need to be done each year. If iron levels are above 0.3 mg/L, you can use an iron filter to lessen the effects of iron in water.
Total AlkalinityNo guideline
  • Alkalinity is the measure of the water’s ability to keep a stable pH.
  • Alkalinity is based on the amount of bicarbonate, carbonate, and hydroxide in water.
  • A low alkalinity level (less than 80 mg/L) can cause corrosion. A high alkalinity level (more than 120 mg/L) can cause scaling.
Bicarbonate, carbonate, and hydroxideNo guideline
  • Bicarbonates, carbonates, and hydroxides are related to alkalinity, salinity (the amount of salt in water), and total dissolved solids (the total amount of minerals in water). High levels of these measurements can cause scaling.

250 mg/L or less


  • Chloride levels higher than 250 mg/L can make water taste salty.
  • High levels of chloride in water can also cause corrosion of plumbing fixtures if there is also a low alkalinity level.
  • Chloride levels in water may suddenly get higher when a water supply is polluted such as from road salt, watering farm land (irrigation drainage), or wastewater from sewers.

1.5 mg/L


  • For good dental health, Health Canada recommends that drinking water has 0.7 mg/L of fluoride.
  • Fluoride levels higher than 1.5 mg/L may cause white spots to form on tooth enamel (called dental fluorosis) in children up to the age of 8.
  • Fluoride levels of 2.5 mg/L or higher may increase the risk of bone fractures and skeletal fluorosis (a bone disease that can cause pain and damage to bones and joints).
  • There are ways to remove fluoride from drinking water with equipment that purifies it using reverse osmosis and water filtering. If you are concerned about fluoride levels in your drinking water, contact your dentist or Alberta Health Services, Environmental Public Health.




1.0 mg/L


10 mg/L


  • High levels of nitrite and nitrate in water can cause methemoglobinemia (blue baby syndrome), a condition that makes it hard for blood to carry oxygen through the body.
  • Women who are pregnant or breastfeeding can pass nitrites and nitrates to their baby which can cause them to develop methemoglobinemia.
  • Infants younger than 3 months of age have the highest risk of developing methemoglobinemia.
  • Talk to your doctor to see if you are at risk of developing methemoglobinemia. People at risk for methemoglobinemia should not eat food prepared with water that has a high nitrite or nitrate level or use water that is untreated for nitrites and nitrates.
  • High levels of nitrites and nitrates in drinking water can be caused by:
    • fertilizer and other agricultural waste
    • decaying plant matter
    • septic systems that aren’t working properly​
  • Boiling drinking water will not remove nitrites and nitrates. When water is boiled, it can make nitrate and nitrite levels even higher.
  • Nitrites and nitrates can be removed by reverse osmosis and other processes to purify water such as distillation or ion exchange. It’s important to find out what is causing high levels of nitrites and nitrates in drinking water and fix or remove the source.

500 mg/L or less


  • Drinking water normally has sulphates. Sulphates can also get into drinking water when plants, animals, and human waste breaks down. Water with sulphates may have sulphate bacteria which turn sulphates into a gas (called hydrogen sulphide) that smells like rotten eggs. Water with sulphate bacteria can cause corrosion.
  • Well water may have hydrogen sulphide. To lower levels, you can add air or chlorine to the water and the filter it.
  • High levels of sulphate can cause loose bowel movements (diarrhea). Babies are more sensitive to sulphate levels than adults. Don’t make formula for babies using water with a sulphate level over 400 mg/L.


The results for conductivity, cation/anion sum, ion balance, and percentage difference on your water test results are only used for lab purposes.

For more information about drinking water, visit:

Alberta Health Services – Information for your Home

Alberta Environment and Parks – Working Well

Current as of: October 11, 2018

Author: Environmental Public Health, Alberta Health Services