City of Castlegar staff say a rotary press is doing exactly what they hoped it would at the south sewage treatement plant, but it’s too soon to tell whether similar equipment will be the permanent solution to problems at the facility.
Assistant utilities manager Aaron Geck and project manager Anne Simonen presented an update to council this week on the latest efforts to deal with the city’s biosolids. In recent years Woodland Park residents have been nauseated by a foul stench that the city hasn’t been able to fix.
In late March, the city brought in a rotary press to dry out biosolids, following an expensive and failed attempt at using geotube technology.
“The team in general is pretty happy with what we’re dealing with now,” Geck said. “It’s a game changer. This is a good news story.”
Geck said there were some hurdles to overcome to get the equipment working, but the unit is now being operated more than expected. The resulting sludge is hauled to the landfill twice a week, unlike the geotube system that remained on site for months before being cut open for removal.
Geck said it’s not ideal to send organic material to the landfill and they have been talking to the Regional District of Central Kootenay about bringing the material to the new organics facility near Salmo to be composted instead.
The city’s three-month contract with the company that provided the press is being renewed for another six months while the city works on a longer-term solution for managing biosolids. The city has already awarded a separate contract to a consultant to find that solution.
Simonen said the consultant has done sampling and testing to understand the biosolids and sludge at the site. They used that information to develop a long list of options, which have since been narrowed down to three, including a permanent rotary press, although if the city goes that route, it will need one with greater capacity. The other two options haven’t been revealed yet.
The city hopes to receive a design by the end of the year for whatever the permanent treatment solution turns out to be and have it built early in 2027. It would remain in place until the sewage plant is decommissioned as part of the city’s even longer-term plans.
Councillors sold on press
But councillors were ready to embrace the rotary press as the solution.
Councillor Sue Heaton-Sherstobitoff, who lives in Woodland Park, said the temporary fix has already proved its worth. She said the smell was particularly bad last year when it got hot, but the only time there has been any odour this year was when the last geotube was decommissioned.
Councillor Sandy Bojechko was leery about choosing a different long-term option when the current one appears to be working.
Simonen said they were “taking a lot of care” with design and concept development to make sure they don’t see another failure along the lines of the geotubes.
“We’ve already validated that we have a system that can work effectively, that doesn’t lead to odours, and we certainly expect that that’s one of the three concepts,” she said. “We have proof of concept that there are solutions that work effectively at the site. I think we can be confident that the future solution would not lead to the same odour issues that we experience with the geotubes.”
Simonen said it’s helpful for the consultant to know the equipment on site is working as well as it is, and they have factored that into their list of options. But she said just because the press works doesn’t mean that other options wouldn’t work.
“So making sure that we’re not pigeonholing ourselves into one solution is important and making sure that we’re considering operational needs and city needs,” she said.
Engineering manager Ryan Niddery said a key to keeping odours away is that the biosolids are kept aerated, processed immediately, and removed within days.
“If that was sitting on site for as long as the geotubes were, you would end up with the same problem,” he said. “It’s just that we’re able to process and get it off site in a quick turnaround.”
As for the operational costs of the temporary system, Geck said he believes it’s similar to what they were paying to operate the geotubes. Treatment plant operators are spending more time running the press, but less time doing other duties as a result.
“Staff in general are way happier,” he said.
