The City of Saskatoon’s wasterwater treatment plant received a $48 million upgrade that will protect the people, property, and environment downstream from Saskatoon along the South Saskatchewan River.

Designated as a Class 4 treatment facility, the highest level of certification in Canada, the treatment of wastewater is regulated by provincial and national criteria.

Originally built in 1971, the Plant has had numerous improvements and expansions to meet new environmental laws and serve the growing population of Saskatoon.

The upgrade included the installation of a fourth digester tank as well as improvements and upgrades to the plantwide heating system including the installation of new boilers, biogas treatment, and flare stacks at the existing City of Saskatoon Wastewater Treatment Plant, says John Lacny, Project Manager. The upgrades included a capacity increase to the existing digester process system and the improvements to the plant heating system which allows the plant to reliably utilize the biogas produced from the digester process to power the boilers that are used to heat the entire plant.

“After completing an assessment of the Wastewater Treatment Plant’s digester process area, it was determined that a fourth digester tank would be required for the plant to meet the required solids retention time for a digester as set out by the Saskatchewan Water Security Agency’s (WSA) sewage works design standards,” says Mike Sadowski, Wastewater Plant Manager.

The primary objective of the project was to address the capacity concerns associated with the digester process area. Adding a fourth digester tank provided the plant additional capacity and because the digester process area is linked to the plant heating system, there was a great opportunity to improve the heating system for the entire plant.

The project also addressed the concern surrounding the excess biogas that was already being produced at the plant. “After completing this upgrade, the plant is now able to capture the biogas produced from the digester tanks and turn it into a renewable energy source where it can be run through the plant boiler system instead of using natural gas,” says Lacny.

Finally, the project upgraded the existing biogas flare system to now include two enclosed flare stacks which allows for excess biogas to be efficiently flared off to the atmosphere.

“With this being the only wastewater treatment plant for the City of Saskatoon, all citizens will benefit from the upgrades of this project as this project ensures that the City of Saskatoon can continue to maintain wastewater processing standards that protect our environment,” says Kelsea Doll, Project Manager. “With the ability to utilize biogas for heating, this project has also reduced the City’s overall natural gas consumption.”

“The City of Saskatoon Wastewater Treatment Plant staff were very supportive throughout the entire project,” Doll adds. “Staff participated in performing design reviews, accommodating the contractor on the plant site during construction, and commissioning the actual system that was installed while still operating and maintaining the other areas of the plant. Other major groups to thank include the City project team, the construction contractor team from Graham Construction, and the design consultant team from Jacobs.”

With the addition of a fourth digester tank, it is anticipated that the Wastewater Treatment Plant will not require a digester capacity increase for another 30 years though this projection is dependent on population growth and operating permit requirements set out by the WSA.

Other process areas of the plant will still require upgrades in the coming years since this upgrade only increased capacity in the digester process area within the wastewater treatment process.

Building a strong project team and developing strong relationships between the plant, design consultant, and construction contractor contributed to the success of the project, says Doll. “There was open and honest communication between the different work groups involved in the project which in turn ensured the project kept moving forward in the right direction and challenges that arose were able to be dealt with quickly and efficiently.”

Although jokingly described as “not the sexiest piece of infrastructure” by city Mayor Charlie Clark, this upgrade has been vital in keeping Saskatoon a great place to live, work, and play everyday by protecting its environment and communities.