City looking at bio reactor to improve Kampeska water quality

In an effort to clean up Lake Kampeska’s waters, the Upper Big Sioux River Watershed Project is looking at building a photo bio reactor.

Project Coordinator Roger Foote appeared before the Watertown Parks, Recreation and Forestry Board Tuesday night to sound out board members’ thoughts on a project that would essentially allow for the artificial growth of algae. That algae could then be used to filter out some nutrients within lake waters and thus make for a clearer looking lake. The proposed project is part of the Lake Kampeska master plan approved last year.

“It’s a series of clear tubes that we would shine light in. The algae would grow like a plant in the water,” Foote said Wednesday. “It’s not a silver bullet for Lake Kampeska. It’s part of a large series of things we need to do to improve water quality.”

With a location yet to be determined, Foote would seek to work with adjacent residents to limit the disruption caused by artificial pink lights that would shine at night. A greenhouse would also be attached using sunlight for algae growth during the day.

As of now, costs and a timeline for the project have yet to be determined. Foote said a total of $4 million has been preliminarily budgeted in the city’s capital improvement program for the 2023 and 2024 fiscal years.

The proposed photo bio reactor project would follow a trial project at the old water treatment plant from 2014 to 2016. During that project, Foote and others monitored the effect algae had in treating contained waters. Foote said that trial produced promising results.

“We basically installed a photo bio reactor in a 100,000 gallon tank,” he said.

Further discussions will likely take place in the coming months among the Park and Rec Board and City Council.