Edmonton's Gold Bar Wastewater Treatment Plant

In the past year, Edmonton's Gold Bar Wastewater Treatment Plant has hosted more than 20 international delegations from Mexico, Europe, Asia and Africa eager to learn about advanced wastewater treatment from one of Canada's environmental leaders.

Gold Bar is the largest biological nutrient removal-based (BNR) wastewater treatment plant in the northern hemisphere. BNR technology was scrupulously tested prior to its implementation, creating a body of knowledge second to none among global practitioners - and one of the reasons that scientists, engineers and municipal officials from around the world travel to Edmonton.

Generating even greater interest this year is the commissioning of a new membrane filtration plant that enables the City of Edmonton to recycle municipal wastewater as industrial process water. This "industrial ecology" approach enables the city to convert a waste stream into an industrial input, eliminating the need to draw additional water from the North Saskatchewan River, and enhancing protection of the downstream ecology.

Accelerated population growth, economic development, and more stringent government regulations make it even more important for cities like Edmonton to manage the urban environment with a view to the future. The innovative practices of the Gold Bar plant contribute to the realization of EcoVision Edmonton,® the city's comprehensive response to the environmental challenges of the 21st century.

Wastewater Treatment Process

Edmonton's Gold Bar plant treats the sanitary sewage and some stormwater for the city of 700,000, and has long prided itself on being a "natural" treatment facility, strongly committed to environmental protection. The plant uses no chemicals to treat wastewater; instead, biological nutrient removal harnesses the natural properties of wastewater to remove phosphorus and ammonia-nitrogen from wastewater. After these harmful substances have been removed, high-intensity ultra-violet light disinfects effluent prior to its discharge back into the river. Every day, 260 million litres of wastewater take a 17-hour journey through the plant, undergoing rigorous, multi-stage treatment.

But the city's drainage branch knew it could do even better.

"Edmonton has always considered itself an environmental protection leader," says John Hodgson, drainage branch manager. "We're one of Canada's first cities to get involved in ISO 14000 [environmental management systems] and we are always working on continual improvement. Looking ahead, we knew that...