The city will soon begin a public consultation program on the future of wastewater management
Nelson City Council decided at its Aug. 19 meeting to apply for a grant of up to $7 million toward the replacement of the pipe that carries sewage from the city to the treatment plant at Grohman Narrows.
The total cost of replacing the pipeline, known as the force main, is an estimated $11.6 million. The force main runs 30 feet below the surface of the Kootenay River.
The grant would be provided by a branch of the federal Community Building Fund, formerly known as the Gas Tax Fund, that funds community infrastructure.
The proposal to apply for the grant received immediate endorsement from council.
“There is infrastructure and there is critical infrastructure, and there is a difference there,” said Councillor Jesse Woodward at the meeting. “I cannot think of a more critical piece of infrastructure, other than the water coming into our town, as the waste leaving it. So I hope this application will carry some serious weight.”
The force main has been in service since 1972, when the Grohman Narrows treatment plant went into service, City of Nelson spokesperson Stephanie Delnea said in an email to the Nelson Star.
“It was considered state of-the-art at the time it was installed, utilizing tar-coated steel, sunk into place and held down by concrete anchors. There have been very few incidents over the decades, but over time the corrosive and abrasive nature of the wastewater is eroding the inner lining.”
There was one major repair in 1992 following damage by a suspected underwater landslide. Since then there have been repairs of holes no larger than a toonie.
That includes a leak that released about one million litres of sewage per day into the Kootenay River between March 27 and April 3, 2024. The city’s then-public works manager said at the time that the amount released was negligible given the fact that Kootenay River flow at that location is 36 billion litres per day.
Delnea said the volume of waste water in the force main is monitored 24-7 by an automated alarm system. The force main is inspected at least once per year by a professional dive team to identify any new hazards around the pipe and the condition of the pipe itself, and to inspect the condition of the repairs that have already been done.
“The next scheduled inspection is in mid-September when the water is still warm, but river flows are lower, and it is safer to conduct the inspection.”
Nelson’s sewage treatment plant releases sewage into the Kootenay River that has been given primary and secondary treatment.
Primary treatment means filtering and settling out of solids, while secondary treatment sees the remaining material broken down by bacteria and ultraviolet light.
The City of Nelson plans to replace the wastewater treatment plant, which it has been described for several years as obsolete and operating beyond its capacity.
As a prerequisite to building a new plant, Nelson is in the midst of the multi-year development of a Liquid Wastewater Management Plan, to be complete by December 2026. The plan, which must meet provincial government requirements, involves hiring technical consultants, producing reports, studying public health impacts, exploring environmental issues and consulting the public.
Public consultation will begin in September.