MELLEN WWTP - Mellen, Wisconsin Wastewater Treatment Plant

MELLEN WWTP is a municipal wastewater treatment facility located in Mellen, Wisconsin, a small community in Ashland County. The plant serves a population of 730 and operates under the regulatory framework of the United States Clean Water Act, which requires secondary treatment for municipal discharges. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 776.01 units and an actual discharge volume of 719.23 units, the facility operates near its capacity. As a US plant, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Wisconsin Department of Natural Resources, ensuring compliance with water quality standards. The treated effluent is discharged into a local water body that ultimately drains into the Lake Superior basin. This region is ecologically sensitive, supporting diverse aquatic life and providing important habitat for fish and wildlife. The plant plays a key role in protecting downstream water quality in the Lake Superior watershed.

The plant discharges into a receiving water body that flows into the Lake Superior basin, the largest of the Great Lakes. This watershed supports coldwater fisheries, including lake trout and whitefish, and is a critical resource for regional biodiversity. The secondary treatment process helps reduce nutrient loading and protect downstream aquatic ecosystems.