HOW WE GRADE YOUR WATER SUPPLY SOURCE

The Canadian Water Quality Index (CWQI) is an effective method to rate the water quality and determine its suitability for drinking purposes. CWQI measures a wide variety of parameters of water quality and then cumulatively translate them into one score.

The CWQI method requires a group of parameters that have drinking water objectives that have been set either by the Canadian government or a province to ensure that the water intended for human consumption.

• Health- Related Standards: shall not contain disease-causing organisms or unsafe concentrations of toxic chemicals
• Aesthetic Objectives: should be aesthetically acceptable and palatable
• Operational Guidelines: should not contain undesirable concentrations of parameters that, if not controlled, may negatively affect the efficient and effective treatment, disinfection, and distribution of water

HOW TO READ YOUR REPORT CARD

A summary of the results is presented in a donut-like chart.
The colouring system is represented by:

• Green — All parameters that are below the objectives/standards
• Red — A parameter that has a concentration above the local provincial or the Canadian objective

The sample example provided has a CWQI of 62 (out of 100). The quality is fair.
A detailed summary of the parameters tested, why each parameter is important, and treatment options are provided in Appendix A.