November 2009 issue
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The Summit Series
More People, More Wastewater
Growing cities constantly struggle to meet the demand residents place on their infrastructure.
The City of Calgary, however, is 50 years ahead of the game when it comes to wastewater treatment
BY CHRISTINE COTTRELL
Editorial Assistant
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TREATMENT TREK |
Like many industrialized cities, Calgary continues to grow — and experience growing pains. But thanks to a new and environmentally sound treatment facility, the city can strike wastewater worries off its list of challenges.
The plant will ultimately meet wastewater requirements for 50 years or up to 1.75 million people. Located in the extreme south end of the city, the site of the Pine Creek Water Management Centre covers 300 acres and has been designed to blend into the landscape.
“Esthetics has been very important,” says project manager Warren Switzer, P.Eng., CH2M HILL. “The plant was designed to integrate into the landscape, so the layout of the structures have low visual impact.”
This Project Achievement Award winner in the 2009 APEGGA Summit Awards has been built on land the city has owned since 1965. In 2004 CH2M HILL was retained as the prime consultant to lead the design, construction and commissioning for the wastewater treatment plant.
The plant is sited alongside the Bow River, an important natural resource to the City of Calgary and surrounding region. With Phase 1 now completed, CH2M HILL and its sub-consultants have used a multi-objective management approach to protect the quality of the Bow River and to provide other environmental and societal benefits.
“The biggest difference in this project compared to others I have worked on has been the frequency of changes, for reasons beyond the city’s immediate control,” notes Mr. Switzer. Consultants have respected and protected wildlife and used the natural shapes of the area for screening, while responding to economic challenges facing the city and the world since the project was tendered.
Special measures were taken during the first phase of the development to protect against wildlife displacement. The city will also ensure measures in future phases minimize the impact on natural resources and wildlife corridors.
The location of the site takes into account the value of the riverbank vegetation. The development setback from the Bow River will protect natural habitats while creating an open space.
The first phase of the tertiary wastewater treatment plant processes 100 megalitres per day. Pine Creek has been designed to meet short- and long-term requirements, with provisions for future modules to be added to increase capacity, as required, to reach up to 700 ML/d, anticipated by 2060.
The disinfection process uses ultra-violet light, eliminating the risks of using chlorination and dechlorination. The biological nutrient removal process takes phosphorus and nitrogen from the water through the use of micro-organisms instead of chemicals, reducing chemical discharges to the environment. A portion of the treated effluent is used to irrigate local golf course and tree nursery developments.
Being a Good Neighbour
Local residents were concerned about noise from the plant, both during and after construction. City of Calgary officials ensured that all contractors adhered to noise bylaws. Water trucks were deployed to control dust. Trees and berms are permanent fixtures, along with noise abatement technology, to mitigate any noise the plant generates.
Odour mitigation received significant attention. Once again city officials were able to reassure those living nearby, explaining that the facility will meet stringent standards established by the city for the project. Mitigation measures will mean that odour is barely noticeable at the fenceline and will be imperceptible at the nearest residence.
An historical resources overview identified no significant paleontological sites in the Phase 1 development. The city conducted an historical resources impact assessment, which identified options for mitigation, such as avoidance, capping, excavation and monitoring.
Wetlands will be developed and the city’s mandate is to continue to expand public pathways along the river.
Pine Creek will also house a University of Calgary research facility, a visitor interpretive centre and a public education area focusing on water technology. Research components include a small wastewater treatment plant, up to 12 research streams that mimic natural flows, riffles and pools. These will be used to examine the behaviour of constituents found in waters near urban development.
In addition to APEGGA’s Project Achievement Award, Pine Creek attained a gold rating in the Leadership in Energy and Environmental Design program. The centre also received two awards of excellence from the Consulting Engineers of Alberta.
Mr. Switzer is pleased with the plant’s performance during the commissioning of Phase 1. “It took just six days for the plant to become fully compliant with very strict Alberta Environment regulations. Normally, it would take up to several months.”
The Project Achievement Award is presented to a project demonstrating engineering, geological or geophysical skills and representing a substantial contribution to technical progress and the betterment of society.