Village on track to meet phosphorus benchmarks

Sustainable farming practices, wastewater treatment improvements key to meeting DNR requirements
Ozaukee Press Staff

The Village of Grafton is on track to hit water phosphorus reduction benchmarks in coming years by encouraging farmers to practice sustainable farming and by making improvements to its wastewater treatment facility.

The village contracted Milwaukee-based engineering firm Symbiont in 2020 to help the village reduce the concentration of phosphorus found in the Milwaukee River as it flows through Grafton. The effort is the result of new Wisconsin Department of Natural Resources requirements regarding phosphorus levels in groundwater.

Phosphorus is a mineral often used in fertilizers that can cause rapid plant growth  when highly concentrated in water. High levels of phosphorus can cause algae blooms, reduce biodiversity and impact recreation in bodies of water.

The DNR is requiring municipalities throughout the state to bring the phosphorus concentrations of their waterways to .075 milligrams per liter, either through improvements to wastewater treatment facilities to remove phosphorus or by preventing phosphorus from entering waterways through other means.

Coming into compliance with the requirement allows municipalities to maintain their Wisconsin Pollution Discharge Elimination System, which allow wastewater treatment sites to discharge treated water into waterways.

Jon Butt of Symbiont provided an update on the firm’s efforts to reduce phosphorus in the village during the April 4 Board of Public Works meeting.

He said Symbiont has been tackling the issue with a watershed-based approach, or a method which removes phosphorus from ever entering the water rather than trying to remove it.

“Our plan is to lower the phosphorus concentration in the Milwaukee River as it flows through the village,” Butt said.

In the past year, Butt said his firm has been working with two local farms totaling 700 acres to promote farming practices that improve soil health and prevent phosphorus runoff.

“There’s a pretty good correlation between good soil and healthy water quality,” he said.

Two methods that farmers have employed are planting cover crops in the late summer and adopting a no-till policy.

Butt said cover crops are crops planted after a farmer’s main crop. The cover crops help hold soil in place and prevent water runoff, keeping phosphorus on the field instead of in waterways.

The no-till method is also a practice that keeps soil and the phosphorus in it sturdy. Butt said without tilling, plant roots are left behind, which keeps the soil structure intact. Seeds are also drilled into the ground by special equipment on no-till fields, meaning that far less soil is disturbed.

The village’s initial median phosphorus level was .084 mg/L but in 2021 it had dropped to .079 mg/L, pushing the village more than halfway to its goal of .075 mg/L.

“We’re more than 50% of the way to our target so we are very encouraged by that,” he said.

Butt said in terms of mass, 2,000 pounds of phosphorus were prevented from entering the Milwaukee River last year, though Symbiont can only account for about 330 of that through work at the farms, according to Butt. He said the discrepancy is likely the effect of other efforts being made to reduce phosphorus upstream of Grafton.

“We’re hopeful that this trend continues,” he said.

For the village to come into compliance with the DNR regulation, Butt said an additional 3,000 pounds of phosphorus will have to be kept out of the river.

To continue toward that goal, Butt said Symbiont plans on expanding the number of farms it works with and will begin looking for one-time purchase opportunities, like buffer strips of grass along farm fields that can catch runoff water.

He added that the villages of Saukville and Grafton have approved contracts to improve phosphorus removal at their wastewater treatment facilities, which could each account for about 1,000 pounds of phosphorus reduction.

Board chairman Tom Krueger asked if the village has to continually provide farmers with financial support on cover crops and other practices for the reduction to remain.

Butt said he believes farmers will see the benefits of the new practices and continue them on their own after several years.

“What we’re providing is a little bit of seed to get that farmer to try something that might be a little uncomfortable for them but what is very clear is that when these guys try this for a year or two or three, this becomes a very sustainable practice,” he said.

He added that with high gas prices, he has heard farmers prefer the no-till method, which only requires farmers to drive in their fields a couple times each year.

This year the village budgeted $157,970 to continue the project — $75,470 for professional services, $80,000 for farm practice improvements and $2,500 for field monitoring.



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Wisconsin’s largest paid circulation community weekly newspaper. Serving Port Washington, Saukville, Grafton, Fredonia, Belgium, as well as Ozaukee County government. Locally owned and printed in Port Washington, Wisconsin.

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