Pollutants Are Abundant In Waterways Surrounding Milwaukee County

May 7, 2019

In older cities like Milwaukee, lead pipes are a potential threat. But there are different problems in rural areas.

Ulao Creek is a tiny stream tucked into a quiet neighborhood in Mequon. On a recent afternoon, the water was high due to heavy rains the night before. And members of environmental group Milwaukee Riverkeeper are testing the water.

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Using a plastic bottle mounted to a pole, Paul Lindquist stands on a bridge and scoops some water from the creek. He then pours it into a long tube. He’s checking for murkiness and the presence of nitrates.

“Now we slowly pull the piece of string that’s in the tube to raise the washer, and we typically just go slowly. We are at about 20 centimeters, which is showing that the water has enough sediment in it that we are unable to see much further than 20 centimeters through the water column,” he says.

Lindquist is a volunteer for Riverkeeper’s citizen monitor program. The manager of the program, Cheryl Nenn, watches the debris as it floats by. She says much of it is contaminated with nitrates – a toxin generated from agriculture.

Paul Lindquist (left) and Cheryl Nenn (right) conduct tests on the murky water at Ulao Creek.
Credit Marti Mikkelson

“We had an inch of rain yesterday. You get a lot of soil that’s running off of farm fields and lands into the water,” she says.

Nenn says about half of the land in this area is used for agriculture. At the same time, she says Mequon and Thiensville are growing communities, and runoff from residential developments is also a threat to the creek.

“We have more and more parking lots and rooftops and paved areas, and so often when it rains you get a lot more water washing off of our streets and our roads and our rooftops, and bringing a lot of sediment and dirt and pollutants with that,” she says.

Nenn says sediment from Ulao Creek floats down to the Milwaukee River, then drains into Lake Michigan, which is a major source of the drinking water supply. But there aren’t just concerns about what’s in treated water that comes from the lake.

Debris in the Ulao Creek after an April rainstorm.
Credit Marti Mikkelson

According to the Department of Natural Resources (DNR), about half of residents, including many in Milwaukee’s surrounding counties, get it from private wells. The DNR’s Bruce Rheineck says nitrate is the most widespread contaminant found in the wells, and it usually comes from farm runoff, animal waste and faulty septic systems. But he says nitrates aren’t as much of an issue in southeastern Wisconsin as in other parts of the state.

“Overall, about 10% of wells are estimated to have a problem with nitrate. In southeast Wisconsin counties, it ranges from under 1% to about 4% having it above the standard,” he says.

Particularly in Washington County, Rheineck says 4% of private wells exceed nitrate standards. Roy Irving, of the Department of Health Services, says scientific evidence suggests that nitrates might be linked with serious illnesses. He says children and pregnant women are most at risk.

“Probably the most well-known health condition associated with nitrates is called infant methemoglobinemia, or blue baby syndrome. There’s also scientific evidence that suggests that nitrates may be associated with certain types of birth defects,” he says.

Irving advises women who become pregnant to immediately stop drinking water with high levels of nitrates.

Jim Holte, president of the Wisconsin Farm Bureau Federation, says his members have been taking steps to mitigate the flow of nitrates into the waterways. He says some producers have installed what’s known as “grass waterways” in their fields. The channels help move surface water across farmland without causing soil erosion – limiting the amount of contaminants that can get into wells.

“We have designs for different grass waterways that will slow the movement of that water, restrict how much water moves off and also restrict the nutrients that can leave the soil,” he says.

Holte was one of several people who testified last month before the Assembly Speaker’s Task Force on Water Quality. It’s concerned about threats to clean water in 11 areas of the state.

Beginning Wednesday, task force members will tour Wisconsin and hold public hearings at each site. The task force is expected to stop in southeastern Wisconsin this summer. The panel hopes to make policy recommendations by fall, designed to improve water quality.