Construction underway for Thompson, Manitoba’s new SBR wastewater treatment plant

The foundation is laid and construction is underway for the City of Thompson’s new $36.5-million single centralized wastewater treatment facility, featuring a sequencing batch reactor (SBR) process to service a projected population of 15,000 people.

The City of Thompson, 740 km north of Winnipeg, Manitoba, was formally established with the discovery of nickel, following several years of mining exploration in the region. Population dropped more than 30% between 1971 and 2011, potentially influenced by the drop in local mining activity. The City currently has a wastewater system built in the early 1960s, and operates a primary plant that treats 70% of its flows. An aerated lagoon handles the remaining 30%. With that system beyond its life cycle, the City has undergone significant financial and environmental analysis to find the best fit for the future of Thompson.

Following the successful startup and commissioning of the new centralized plant, the existing facilities, including the lagoon, will be decommissioned, and the single new facility will handle all wastewater generated by the City.

“Setting this project in motion has been one of the flagship achievements of our council, and it’s exciting to see this massive investment becoming a reality,” said Mayor Dennis Fenske, following a council tour of the construction site in October 2017. “This facility is a key step in securing the future of Thompson’s infrastructure and the community as a whole, and I’m proud to say that this facility will be part of the legacy of our current council.”

According to a report by project manager Stantec Consulting Ltd., the new SBR tanks are based on the principles of an activated sludge process and are designed for organics removal, nitrification and denitrification along with phosphorus removal. A disinfecting stage will use ultraviolet light to destroy foreign bacteria and viruses before the effluent is returned to the environment. The new filtration system will eliminate foul smells, addressing a long-standing issue with the City of Thompson’s existing wastewater infrastructure, according to a City press release.

Stantec indicates that two sequencing batch reactor trains are proposed. The sequencing batch reactor basins will decant treated wastewater by gravity to an effluent equalization chamber on an intermittent basis. As the sequencing batch reactor is a batch process, this decant rate is higher than influent flow to the SBR basin, states the consultant.

Manitoba Conservation and Water Stewardship indicated that the design should be developed to achieve maximum denitrification possible with current wastewater quality. In the Stantec report, the group said it “hopes that, with proper water conservation and maintenance of the sewer collection system to reduce inflow and infiltration in the future, the City will be able to improve the strength of the raw wastewater which will ultimately favour better denitrification.” Stantec indicated that, based on preliminary process modeling, it is anticipated that the effluent total nitrogen would vary from 15 mg/L to 25 mg/L.

New force mains and lift station upgrades are also taking place for the treatment facility. The new main will carry sewage and run-off that previously would have fed into the sewage lagoon on the south side of the City. The main will render the sewage lagoon obsolete, eliminating another source of sewage smells due to wastewater treatment.

The total estimated cost of the project is $36.5 million, with $12.1 million coming from the New Building Canada Fund’s Provincial-Territorial Infrastructure Component-National and Regional Projects, $12.1 million coming from the Government of Manitoba, and the City of Thompson covering the remaining amount.

Bird Construction is the general contractor for the project, which has an estimated completion date of March 2019.