FOND DU LAC (NBC 26) — Phosphorus can act as an important nutrient for all living beings. But high concentrations in water can cause algae blooms, which can interfere with local wildlife and activity on lakes like Lake Winnebago.
"You would be limiting the fish habitat, you’d also be limiting the area where you’d want to swim, or boat or recreate. It’s just not pleasant to be around," said, Paul DeVries, the Fond du Lac Director of Public Works.
That could create problems for families like Shane Miller's, who frequently swim, fish, boat and jet ski in Lake Winnebago. Miller said he enjoys the clear water currently at the lake, but more algae could interfere with some of their favorite activities.
"Especially here out at the park it would definitely make things less enjoyable," Miller said.
The Fond du Lac Wastewater Treatment Facility averages about 0.3 milligrams per liter of phosphorus exiting the treatment plant, which is currently under the Department of Natural Resources's standard of 0.8 milligrams per liter. For every pound over 0.2 milligrams per liter, the city has to pay counties surrounding the watershed $50. That includes Fond du Lac, Calumet and Winnebago counties.
The Department of Natural Resources is lowering that limit to 0.19 by 2027. And while the city of Fond du Lac is still negotiating with the DNR to determine the limit for next year, they are making adjustments now.
“Over the course of the last four to five years, my staff here has really done an excellent job at making modifications here at the plant to improve treatment, both chemically and biologically," Cody Shoepke, the Fond du Lac Wastewater Facility Superintendent said. "Our facility was not designed for Biological Phosphorus Removal. So in our secondary treatment process, we've made a lot of modifications.”
The wastewater treatment plant treats water from sewer, residential and industrial waste. But heavy rain can increase the total amount of water flowing through the plant, making it more difficult to treat for phosphorus.
“Clean Water shouldn't need to be treated, but because of old plumbing or decaying pipes within the collection system that rainwater gets in there," Schoepke said. "And Fond du Lac has a significant problem with that.”
Schoepke said the city is currently on track to meet future goals.
“Phosphorus is definitely one of those pollutants that is of concern, and Wisconsin has really hit it head on in addressing impaired water bodies, such as for us Lake Winnebago.”