Mattoon WWTP - Secondary Treatment Plant in Mattoon, Wisconsin

Mattoon WWTP is a municipal wastewater treatment facility located in Mattoon, Wisconsin, a small community in Shawano County. The plant serves a population of 435 and is part of the region's water infrastructure, handling domestic wastewater from the local area. The plant provides secondary treatment, which is the standard level required by the US Clean Water Act for municipal facilities. With a designed capacity of 143.85 million gallons per year and an annual discharge volume of 136.28 million gallons, the plant operates near its capacity. As a small facility, it is subject to state-level NPDES permitting under EPA oversight. The treated effluent is discharged into a local waterway that flows into the Wolf River system, ultimately reaching Lake Michigan via Green Bay. The plant plays a key role in protecting downstream water quality in this ecologically important watershed, which supports diverse aquatic life and recreational uses.

The plant discharges into a tributary of the Wolf River, which flows into Lake Michigan via Green Bay. This watershed supports a variety of fish species and is part of the larger Great Lakes ecosystem. The plant's secondary treatment helps reduce nutrient and organic pollutant loads, protecting downstream water quality and aquatic habitats.