Wetland Wastewater Treatment Facility

Helps Protect the Great Lakes

The Kettle Moraine Lutheran High School replaced an old septic tank with an engineered wetland to filter their wastewater, thereby removing excess nutrients from the water supply and creating a habitat for local wildlife.


Wetland environments are known as natural filtration systems, removing or capturing nutrients to prevent algal blooms downstream. The Kettle Moraine Lutheran High School has harnessed this power of wetland biology to naturally filter the wastewater from the school. The engineered wetland system uses a mix of bacteria populations, a solar powered nitrate pump, and windmill for aeration, as well as wildflower and prairie grasses to digest and filter the nutrients from human waste. This process makes the water safe by the time it enters the ground water. After flowing through the school’s wetland, the water makes its way through the Jackson Marsh, then the Milwaukee River, and finally into Lake Michigan. Besides being an effective way of preventing excess nutrients from entering the watershed, the engineered wetland is used by the teachers as a hands- on lesson about the water cycle and water quality. Students of all ages—not just those attending the high school—are educated about the importance of wetland ecosystems and the roll they play in filtering water.

Resource Challenges Addressed

  • Excess nutrients in the water cycle
  • Lack of habitat for wildlife
  • Old septic tank in need of replacement


A windmill near a solar panel

A windmill and solar panel stand in the constructed wetland. The solar panel provides power to run monitoring equipment, while the windmill aerates the aerobic bacteria tank that processes the effluent. Credit: Tom Mellon.

Results and Accomplishments

By using an engineered wetland to treat wastewater, the Kettle Moraine Lutheran High School has improved water quality and increased community understanding of the importance of wetland ecosystems. The wetland has also created a space on campus for waterfowl, amphibians, and even beavers to live. In 2012, they upgraded their system by adding a vertical flow wetland, which allows already treated water to percolate through sand and plants to be further cleaned. About 10 percent of this water is redirected for further treatment, decreasing the likelihood that excess nutrients will find their way into the Great Lakes. The filtration system works so well that in about 25 years the water filtered by this wetland would be drinkable.