It’s taken three years—and $9 million—but things are flowing well at the upgraded secondary water pollution control plant in the west end of Fort Frances.
The new plant, which switched from a mechanical to hydraulic operation, is allowed a maximum 25 mg/litre each of biological oxygen demand (BOD) and suspended solids per day (averaged over the month).
That’s half of what it was allowed before.
On its second day running, though, samples from the wet side showed nine mg/litre BOD and six mg/litre suspended solid.
“The plant, under normal running, is designed for 10 [mg/litre per day],” Bruce Spottiswood, superintendent of works (facilities), noted Friday. He added it is designed to flow 19 million litres of sewage a day, with a maximum peak flow of 25 million litres.
“Today we’re running at about five [million litres]. We’ll run all winter at five,” he said.
In April, with the spring runoff, Spottiswood said the plant averages about 10 million litres per day.
Fort Frances was first notified about eight years ago that it was one of 40 primary treatment plants across the province that would have to include a secondary treatment into the process.
Construction started on the site in August, 1996, with Jan. 20, 1998 being the project’s commissioning date.
“When we were ready to start up, it was right before Christmas. But the plant is so complex to get going that we made an arrangement with the contractor that we would extend his contract for a couple weeks,” Spottiswood said.
And it took a week once the process started. The consultant arrived Jan. 5, and two days later, they started introducing the “activated sludge" or "sweetener stock.”
Spottiswood explained these were “bugs” that break down the waste. The plant received 30,000 gallons of the activated sludge from Boise Cascade in International Falls.
“The bugs have got to have a lot of air to get them to multiply. And then they also have to have raw sewage so they have something to eat,” he noted.
“This is what they call a biological process.”
The trick is to get a balance so that the bugs will eat everything but not to let their population climb too high.
The secondary clarifier, new to the system, removes the chlorine and kills the bugs with ultra-violet light so they aren’t dumped back into the river.
Another big change is converting the anaerobic digester to aerobic, which cuts down on gases being emitted as the sewage is broken down. And the “grits system” is now automated so foreign matter no longer will have to be manually removed.
The automation and revamped electrical system will be a big plus, Spottiswood said. Now if there is a failure somewhere in the system, even at one of the lift stations, the computer will phone the person on call and relay exactly what is wrong and where.
The first line to the sewage treatment plant—representing about 15 percent of the town’s flow—opened Jan. 8. Another line opened the next day to bring the flow up to 50 percent.
By Jan. 12, the flow to the new portion of the facility were brought up to 100 percent.
“It’s up and running now but we had to have part of the plant that could still run while they were doing all of this,” Spottiswood noted, adding other work was expected to be completed next month.
But while the upgrade has made a big difference to the plant itself, Spottiswood admitted people probably wouldn’t notice any difference with their sewage.
“It could affect them in the sense that now that we have state-of-the-art primary and secondary treatment that meets all the criteria from the Ministry of Environment, it could allow for secondary industry to come into the community,” he noted.
“I look forward to what this secondary treatment plant can do in regards to expanded opportunity,” Mayor Glenn Witherspoon enthused Monday.
The public will have a chance to tour the new facility during open houses which will be slated shortly.