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 chemicals in your drinking water, including those that can be harmful to your health.
To understand your drinking water chemical test results, use the information below. Depending on the chemical, the guidelines that are used to test your water can be based on:
-
Maximum acceptable concentration (MAC): This is about health and safety. It is the highest amount of a chemical 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): This is about the taste, smell, and look of your drinking water. The AO is used to decide if people will use or drink the water.
If you have any questions about your drinking water test results, contact Alberta Health Services
Environmental Public Health.
Talk to your doctor if you have questions about chemicals in your drinking water and if they could affect your health.
Drinking water chemical test results
pH
Guideline:
7 to 10.5
What you need to know:
- pH is a measure of how acidic or how basic your water is.
- A pH of 7 is neutral (not acidic or basic). A pH lower than 7 is acidic. A pH higher than 7 is 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. This metal can then end up in your water. If metals like lead, cadmium, zinc, or copper from pipes get into drinking water, it can lead to health problems.
- As pH gets higher, you’re more likely to see a build-up of minerals (called scaling) on cookware (like pots and pans), plumbing, and appliance parts.
Sodium
Guideline:
AO: 200 mg/L or less
What you need to know:
- 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 for you if you follow a diet that limits sodium.
- Talk to your doctor if you follow a diet that limits sodium to 1,500 mg or less per day and have concerns about the level of sodium in your drinking water.
Potassium
Guideline:
No guideline
What you need to know:
- Most drinking water is low in potassium. It is not a concern if you are healthy.
- Water softeners that use 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.
Calcium
Guideline:
No guideline
What you need to know:
- Calcium is safe for people who are healthy. It is normally found in food and drinking water.
- Calcium makes water harder. See the section on total hardness below for more information about hard and soft water.
- Calcium levels higher than 200 mg/L may cause scaling on cookware (like pots and pans), plumbing, and appliance parts.
Magnesium
Guideline:
No guideline
What you need to know:
- Magnesium is safe for people who are healthy. It is normally found in food and drinking water.
- Magnesium makes water harder. See the section on total hardness below for more information about hard and soft water.
- Magnesium levels higher than 150 mg/L may cause loose bowel movements (diarrhea) if people are not used to drinking it.
Total hardness
Guideline:
No guideline
What you need to know:
- Total hardness is a measure of calcium, magnesium, and other minerals that affect the hardness of your 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.
- There are 4 levels of water hardness:
- soft: 0 to 60 mg/L
- medium hard: 60 to 120 mg/L
- hard: 120 to 180 mg/L
- very hard: 180 mg/L or higher
Total dissolved solids (TDS)
Guideline:
AO: 500 mg/L or less
What you need to know:
- TDS is a measure of all minerals in your water. A high TDS can cause scaling and change the way your water tastes and smells.
- Water with a low amount of TDS may taste flat.
- A high TDS can prevent water treatment devices from working properly.
- Water with a TDS level over 1,000 mg/L can have a different taste and smell and can cause a lot of scaling.
Iron
Guideline:
AO: 0.3 mg/L or less
What you need to know:
- 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. You may need to do this every year.
- If your water’s iron levels are above 0.3 mg/L, you can also use an iron filter to lessen the effects of iron in your water.
Total alkalinity
Guideline:
No guideline
What you need to know:
- Alkalinity is the measure of your 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 hydroxide
Guideline:
No guideline
What you need to know:
- Bicarbonates, carbonates, and hydroxides are related to alkalinity, salinity (the amount of salt in water), and TDS.
- High levels of these measurements can cause scaling.
Chloride
Guideline:
AO: 250 mg/L or less
What you need to know:
- Chloride levels higher than 250 mg/L can make your water taste salty.
- If you also have a low alkalinity level, high levels of chloride in water can cause corrosion of your plumbing fixtures.
- Chloride levels in water may suddenly get higher when a water supply is polluted, like from road salt, watering farmland (irrigation drainage), or wastewater from sewers.
Fluoride
Guideline:
MAC: 1.5 mg/L
What you need to know:
- 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.
- High fluoride levels 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 your drinking water with equipment that purifies it using reverse osmosis and distillation. If you are concerned about
fluoride levels in your drinking water, contact your dentist or public health inspector.
Nitrite and nitrate
Guideline:
Nitrite
MAC: 1 mg/L
Nitrate
MAC: 10 mg/L
What you need to know:
- 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.
- If you are pregnant or breastfeeding, you can pass nitrites and nitrates to your baby, which can cause them to develop methemoglobinemia.
- Babies younger than 3 months of age have the highest risk of developing methemoglobinemia.
- Talk to your doctor to see if you or your baby is at risk of developing methemoglobinemia. If there is a risk, don't eat food prepared with water that has a high nitrite or nitrate level and don’t use water that has not been treated for nitrites and nitrates.
- High levels of nitrites and nitrates in drinking water can be caused by:
- fertilizer and other agricultural waste
- dying plant matter
- septic systems that aren’t working properly
- Boiling your water will
not remove nitrites and nitrates. When water is boiled, it can make nitrate and nitrite levels even higher.
- You can remove nitrites and nitrates from your water 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 your water so that you can fix or remove the source of the problem.
- Learn more about
nitrate and nitrite in your drinking water.
Sulphate
Guideline:
AO: 500 mg/L or less
What you need to know:
- Drinking water normally has sulphates. Sulphates can also get into drinking water when plants, animals, and human waste break down.
- Water with sulphates may also have sulphate bacteria. These bacteria 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 of hydrogen sulphide in your water, you can add air or chlorine to the water and then filter it.
- High levels of sulphates can cause loose bowel movements (diarrhea).
- Babies are more sensitive to sulphate levels than adults. Don’t make infant formula using water with a sulphate level over 400 mg/L.
Your drinking water chemical test results will also show results for conductivity, cation/anion sum, ion balance, and percentage difference. These results are only used for lab purposes.
