The City’s Water Quality and Regulatory Assurance (WQRA) division provides scientific, technical and regulatory services to the utility protecting the environment, public health and City infrastructure. The management and staff of WQRA are committed to high-quality professional practices through continual improvement ensuring the quality of its services and accuracy of the analytical testing.

The City of Calgary WQRA laboratories are accredited for those tests listed on the Scope of Testing through the Canadian Association for Laboratory Accreditation (CALA) to ensure we meet and maintain the requirements of the ISO/IEC 17025:2017(E). WQRA laboratories produce data of high quality through accurate and reliable testing. Calgarians can be assured that our water is safe and high quality.

Calgary's water is considered hard because of the amount of calcium and magnesium in the water from the Bow and Elbow Rivers.

Water hardness is caused by calcium and magnesium in the ground and surface water. These minerals come from rock such as limestone that dissolves in our river system. The results of having hard water can include difficulty making lather or suds while washing and/or a build-up of minerals on taps and other fixtures.

The hardness of Calgary's water varies seasonally and by location:

• The Bow and Elbow Rivers each have different hardness levels. 
• The lowest hardness levels are typically during spring snowmelt and the highest. hardness levels are between December and February.

Generally, people in the northern half of the city receive water from the Bow River through the Bearspaw Water Treatment Plant. Residents in the south receive most of their water from the Elbow River through the Glenmore Water Treatment Plant.

Water Hardness, mg/L CaCO₃

*ranges for 2025

There are no known health effects associated with calcium and magnesium minerals in drinking water. However, conventional water softening systems (those that use salts) may not be suitable for people on sodium-reduced diets.

We recommend that consumers thoroughly research the various water softener systems available before deciding whether or not to soften their water.

For more information on water hardness please see the Canadian drinking water quality guidelines. 

Limit specified by Guidelines for Canadian Drinking Water Quality (Health Canada December 2025) or Alberta Government operating approval for aesthetic, health, and operational rationale.

• CU = Color Units.
• NTU = Nephelometric Turbidity Units, a measure of water clarity.
• MPN = Most-Probable Number.
• mg/L = milligrams per litre, or parts per million (ppm)
• (a) Aesthetic objective
• (b) Limit based on annual average
• (c) Operational guidance objective.

• Watershed Surface Water Quality Data
• Watershed Monitoring Program sampling locations
• City of Calgary Water Sonde data
• Wastewater Treatment Plants Effluents (as reported to AEPA)