Located in the Canadian Rockies, the town of Banff is famous for its spectacular natural beauty and each year hosts about four million visitors. The town is the first municipality incorporated in a na...
Located in the Canadian Rockies, the town of Banff is famous for its spectacular natural beauty and each year hosts about four million visitors. The town is the first municipality incorporated in a national park.
Recognizing their role as park stewards, the 7,000+ residents implemented a “No-Net-Negative Environmental Impact Philosophy,” and decided to upgrade the wastewater treatment plant in order to improve the quality of the wastewater it discharges to the Bow River.
Associated Engineering were the program managers for the $12 million upgrade, which was completed in February 2002. The consulting engineers helped the town decide the project delivery method, secure agency funding, obtain approvals and manage public relations. They also developed the conceptual design for the upgraded plant and managed the design and construction. Earth Tech Canada is the design-build-operator.
The effluent standards for the upgraded plant are among the most stringent in North America. Three federal regulatory bodies govern the plant — Parks Canada, Environment Canada, and Alberta Environment — so the effluent standards had to satisfy them as well as stakeholders who are interested in preserving Banff as a UNESCO World Heritage Site. After a comprehensive consultation process, the town moved beyond effluent criteria suggested by Alberta Environment and established their own “Banff Leadership Targets” (see table).
The existing plant used a high rate activated sludge biological wastewater treatment process. It had a limited ability to remove nutrients such as nitrogen and phosphorous without chemicals.
For the upgrade, the town favoured biological nutrient removal (BNR) over chemical treatment methods. The town also encouraged an innovative design that would reuse existing equipment, tanks, piping and buildings. As a result, the plant upgrade uses the same site footprint as the existing plant.
The upgrades include: fine mechanical screens, an upgraded odour control, primary clarifier, bioreactors retrofitted to a three-stage BNR process; secondary clarifier, dual-media sand filters, ultraviolet disinfection and biosolids composting.
In addition to improving the water and air quality, the upgraded plant has more energy efficient processes, such as re-using waste heat from the plant air compressor to heat the building. The plant’s electrical energy consumption has been reduced by more than 15%. In addition, the plant’s natural gas consumption has been reduced by more than 50%. The town and Earth Tech share the energy savings.
Owner: Town of Banff
Program manager: Associated Engineering, Burnaby, B.C. (Ian Wright, P.Eng., Richard Watson, P.Eng., Rick Corbett, P.Eng.)
Subconsultants: Highwood Environmental Management
Design-build-operators: Earth Tech Canada/Maple Reinders (Bill Berzins, P.Eng., Joe Zwaagstra, P.Eng.)