TREE FOR LIFE AWARD | CH2M HILL Pine Creek Wastewater Treatment Plant

The Pine Creek Wastewater Treatment Plant in Calgary is a facility that incorporates advanced technology and provides the highest quality of treated effluent among all major cities in western Canada. The plant also protects the integrity of the Bow River, which is an important habitat for fish and wildlife and one of the province’s vital water resources.

The facility is designed to accommodate the city of Calgary’s immediate and long-term needs in an efficient, economic and environmentally responsible manner. It has an initial capacity of 100 ML/d to serve a population of 250,000. It also allows for expansion to an ultimate capacity of 700 ML/d to serve 1.75 million people.

As prime consultant, CH2M HILL together with its subconsultants provided conceptual, functional, and detailed design; construction services; commissioning; and post-construction services. Construction was completed in October 2009 although the plant has been treating wastewater since October 2008.

Groundbreaking Treatment Processes

The plant incorporates next generation treatment processes, including biological nutrient removal (BNR), effluent filtration employing filter disk technology, and ultra-violet (UV) light disinfection. BNR technology reduces the volume of waste sludge produced and increases the nutrient value of the biosolids so that they can be used as a soil conditioner and fertilizer. The treatment process also generates biogas that is used to generate process heat plus centralized space heating for the entire plant. In the future, the biogas will be used to generate electrical power for the plant.

The BNR, effluent filtration and UV disinfection processes reduce the need for chemical treatment.

The tertiary filtration facility is the largest of its kind in the world. The technology uses low-head fabric disk filters that produce high quality effluent with very little amounts of suspended solids or phosphorus. The project team used a collaborative pilot project to address the performance and risks of advancing this technology to such a large-scale installation.

Once treated, the effluent is discharged to the Bow River via diffusers constructed below the river bed to avoid affecting the river’s flow regime.

The plant exceeds all treatment guidelines and regulatory requirements, easily achieving the following effluent criteria even though the facility is now approaching design capacity: CBOD (15 mg/L); TSS (20 mg/L); total phosphorus (0.5 mg/L); total nitrogen (15 mg/L); ammonia (summer/winter) (5/10 mg/L); and fecal coliforms (200 per 100 mL).

A portion of Pine Creek’s treated effluent is reused within the plant and to irrigate a nearby city-owned tree nursery and the Blue Devil golf course. This use of the treated effluent helps Calgary achieve its long-term water efficiency goal, which is to reduce the use of potable water for non-potable needs.

Reduced Ecological Footprint

The city of Calgary embraced sustainable development principles for the project to minimize its ecological footprint and use of resources. Triple-bottomline analyses that balance environmental, societal, and economic needs were an integral part of the decision-making process.

The plant is surrounded by established and future residential neighbourhoods, and two golf courses. It is a highly visible facility overlooked by a 50-metre high escarpment with an important wildlife corridor at its base. Additionally several archaeological sites are located along the Bow River’s banks.

The approach to the planning and design was therefore to work with the natural elements of the site and to integrate the facility into the landscape. Between the plant and the river and escarpment, for example, landscape buffers were laid out in vegetation patterns found elsewhere along the valley. Also the landscaping provides stormwater treatment and river edge protection.

The LEED (Leadership in Energy and Environmental Design) green building rating system guided the design and led to features such as green roofs, the use of locally-available and recycled construction materials, and the minimization of construction waste. The heating and cooling systems maximize energy efficiency and reduce greenhouse gas emissions. The Operations, Maintenance and Administration Building has achieved LEED Gold Status.

Managing the project in Alberta’s overheated economy and construction environment demanded the project team operate with both flexibility and agility.

The project involved 31 construction and procurement contracts. To manage them the team developed the following three-pronged approach: establish an appropriate size for the contract packages, adopt a risk-sharing approach, and customize the construction schedule.

A future addition to the site will be the Pine Creek Research Centre, which is in design development. A collaborative effort between the city and the University of Calgary, the centre will be used for operator training and for testing new treatment technologies. It will have a research pilot plant and a series of research streams to study the fate of micro-constituents in the natural environment.

Project name: Pine Creek Wastewater Treatment Plant, Calgary

Award-winning firm (prime consultant, project management, and process mechanical engineering lead): CH2M HILL, Calgary (J. Warren Switzer, P. Eng., M. Kim Fries, P . Eng.) Owner: City of Calgary

Other key players: Stantec (process mechanical, civil, structural); AECOM Canada (process mechanical, building mechanical, electrical, instrumentation & controls); GEC (architecture); O2 Planning & Design (landscape); Thurber Engineering (geotechnical); Hydroconsult EN3 (water quality, hydrotechnical); Designworks (LEED); BTY (costing); Robinson, Stafford & Rude (value engineering)

Supplier: Trojan Technologies (UV disinfection)