North Saskatchewan River - Water Quality
Alberta Environment and the City of Edmonton monitor and study the water quality of the North Saskatchewan River for:
- Bacteria, nutrient and heavy metal levels
- Health of organisms living on the river bottom
Muddy Appearance of the River
The natural state of the river changes dramatically throughout the year. In the spring, the river appears muddy due to naturally occurring sediments which are washed into the river by increased flow. In late summer and fall, the river flow slows down and the water clears up.
Water Quality Investigations
An Alberta Environmental Protection report (AEP, January 1994) on the water quality of the North Saskatchewan River concludes that "The water quality of the North Saskatchewan River downstream of Edmonton has improved considerably since the 1950's. . . " . However, there was still a concern in this report about the levels of bacteria and nutrients resulting from municipal discharges.
Impacts on River Water Quality
The City of Edmonton affects the river through discharges from
- Storm sewer outfalls
- Combined sewer overflows (CSOs)
- Gold Bar Wastewater Treatment Plant
Studies have found increases in bacteria levels during wet weather (rainfall) discharges, mostly due to combined sewer overflows. The increase in bacteria could cause concern for people in direct contact with the river during or immediately following wet weather.
The combined sewer overflows and the Gold Bar Wastewater Treatment Plant also introduce a large amount of nutrients into the river. Nutrient enrichment can upset the natural balance of the ecosystem by providing more "food" for certain organism and plants than normally would be available. Excessive plant growth is undesirable because it blocks the sunlight.
Watershed Contaminant Reduction
The Edmonton Watershed Contaminant Reduction Index was developed to support the City’s Environmental strategic plan, The Way We Green. One of the corporate outcomes in The Way We Green is “Edmonton strives to be a leader in environmental advocacy, preservation, and conservation”, and the index is one of the measures of that outcome.
This index also reflects the City’s progress on other programs such as the Combined Sewer Overflow Control Strategy and the Total Loadings Plan, which are requirements of the Approval to Operate, issued by Alberta Environment and Water.
Water Quality and Fish
You should not eat fish from the North Saskatchewan River more than once a week; pregnant women should not consume the fish at all. And do not eat the liver or other organs that accumulate mercury. Fish in the North Saskatchewan River can have high enough mercury levels to take caution.
The mercury in many areas of the province, including the North Saskatchewan River, is likely from natural sources.