Confederation Way Sanitary Sewer facilitates growth and alleviates sewer flooding in Fort McMurray

Over the past two decades, the Timberlea Neighbourhood in Fort McMurray has been subject to flooding during heavy rainfall events. These storm events overwhelm the sanitary sewer system, causing the sewer to surcharge and backup, resulting in basement flooding. In 2014, the Regional Municipality of Wood Buffalo developed a Wastewater Master Plan (WWMP) for Fort McMurray with a focus to prioritize resolving this problem. The Municipality defined the Confederation Way Sanitary Sewer Upgrade capital project to address areas prone to sewer surcharging.

Project Manager, Owen Mierke, tells us, "The scope of the project sought to address sewer back-up and failing infrastructure, and accommodate future growth. The first phase of the project addressed localized basement flooding, while the second phase delivered larger system upgrades."

Phase 1 traverses through the existing Timberlea neighbourhoods, along the top of the bank, and terminates at the existing trunk sewer in the north boulevard of Confederation Way.

Phase 2 extends from Phase 1 and includes replacing an existing 450 millimetre gravity trunk sewer with a 750 millimetre gravity trunk sewer, a siphon inlet control structure, upgrading an existing double-barrel (500 millimetre and 300 millimetre) siphon with a triple-barrel (650 millimetre, 650 millimetre, and 550 millimetre) siphon, metering chambers, a flow control structure, and a rock trap structure at the wastewater treatment plant.

Using an integrated design approach, the project team collaborated with the Municipality, geotechnical specialists, trenchless contractors, residents, regulatory agencies, general contractors, and multiple stakeholders to develop an innovative design that addressed the complex geotechnical issues and built-up environment. Associated Engineering implemented a tailored project management plan to help address the project’s many challenges.

"Risk management, an integrated project delivery approach, contractor pre-qualification, proactive communication, and extensive stakeholder engagement with the residents and municipal stakeholders contributed to public acceptance and the success of the project."

The 2016 Fort McMurray wildfire had a large impact on this project, affecting the scheduled completion and transportation and construction logistics. The Municipality had to minimize traffic disruptions on the wildfire rebuild haul routes for Stone Creek, within the residential neighbourhood of Timberlea, in which wildfire destroyed 379 structures, and was located beside the project site. Owen tells us, "Offloading of materials and equipment was restricted to single-lane temporary closures, as total closure would have impacted the contractor’s completion of wildfire restoration works."

Extending from the Timberlea Neighbourhood to the wastewater treatment plant two kilometres away, with 100+ metre elevation difference, the Confederation Way Sanitary Sewer upgrade traversed unstable slopes; crossed several pipelines, shallow utilities, and two interchanges; and passed through the built-up residential neighbourhood and a busy wastewater treatment plant site that never shuts down. Using trenchless technologies, including horizontal directional drilling (HDD), microtunnelling, and pilot-tube auger boring, minimized impact on the environment, residential neighbourhoods, and the public.

Substantially completed in 2023, the $40 million Confederation Way Sanitary Sewer Bypass (Phase 2) project provides the Timberlea Neighbourhood with additional sewer capacity, supporting growth and reducing risks associated with basement flooding due to sewer back-up. In addition to providing a resilient sanitary sewer trunk, the Municipality received the added benefit of modern flow control and metering, regulating flows to the treatment plant and easing plant operations. The project demonstrates an integrated design and construction approach and proactive and open stakeholder engagement to implement infrastructure that benefits the community.

The project received an Award of Merit at the Consulting Engineers of Alberta Showcase Awards in 2024.