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Restoring the integrity of aquatic ecosystems in Mountain National Parks

30 years of monitoring shows improved water quality is directly related to better park management practices

A long-term water-monitoring program conducted by Parks Canada and Environment Canada reveals significant improvements in overall water quality for key headwater aquatic systems in Alberta. The positive trend in water quality over the past 30 years is directly related to improved water-quality management practices within Banff National Park of Canada and Jasper National Park of Canada.

Water quality has been monitored monthly in the Mountain Parks since 1973, in the watersheds of the Bow, North Saskatchewan and Athabasca rivers. Improvements in concentrations of nutrients and bacteria were recorded at downstream sites, and were particularly evident in the lower Bow River below the town of Banff.

This assessment examined over 60 water-quality parameters, paying particular attention to nutrient levels. Nutrients are essential for aquatic life, but an excessive nutrient build-up (especially phosphorus and nitrogen resulting from human activities) can lead to eutrophication. Eutrophication results in algal blooms that can adversely affect water supply, livestock watering, irrigation, navigation, angling and water sports.

The significant improvements observed in the lower Bow, particularly in the last decade, are directly related to improvements to Banff.s sewage treatment facility. The extreme coliform concentrations observed in the early years of the study period (1970s-1980s) have virtually disappeared. Increasing phosphorus trends, which began before 1989, have significantly dropped off and average concentrations have been reduced.

Although the lowering of nutrient concentrations is substantial so far, nutrient enrichment remains the main concern for aquatic ecosystems within these national parks. Treatment plants can remove significant amounts of wastewater contaminants such as grit, debris, suspended solids, pathogens, oxygen-depleting wastes, nutrients, roughly 200 different metals, persistent organic compounds and other chemicals. A "tertiary treatment" capacity allows for an advanced wastewater treatment approach, using additional filtering or chemical or biological processes to remove specific compounds or materials that remain after the initial treatment.

In 2003, after the completion of upgrades raising the Banff, Lake Louise and Jasper municipal treatment facilities to a full tertiary treatment level (including phosphorus removal), the downstream sites on the Bow and Athabasca rivers are expected to recover even more. These upgrades are major steps toward maintaining and restoring water quality and aquatic biodiversity to park waters. Parks Canada will continue to monitor water quality and the relationship to the ecosystems these waters support.

Responsibility for the management of water resources in Canada is shared among municipal, provincial, territorial and federal governments. The extensive data gathered by this program monitoring Canadian rivers advances efforts to standardize information about the quality of surface and ground water sources across Canada and about the ecological effects of pollutants in aquatic ecosystems.

The drinking water for Alberta cities flows out of the Mountain National Parks. Success in protecting water quality in these parks is good news for Albertans and good news for the parks' ecosystems.

Results

• Improved concentrations of nutrients and bacteria at downstream sites, especially in the lower Bow River.
   
• Improvements are directly related to upgrading the sewage treatment facility in Banff.
   
• The extreme coliform concentrations observed in 1970s and 1980s have virtually disappeared.
   
• The increasing phosphorus trends seen before 1989 have been curtailed and average phosphorus concentrations have been reduced.
   
• Continuous, long-term and broad coverage of this monitoring program provides unique data on key Canadian rivers and sets the standard for coordinating and integrating data from provincial, national and other sources.
   
• The quality of drinking water in Alberta's cities has improved.

Bow River surrounded by mountains © Parks Canada / T. Grant / 1978