Marathon City WWTP - Advanced Wastewater Treatment in Marathon City, Wisconsin

Marathon City WWTP is a municipal wastewater treatment facility located in Marathon City, Wisconsin, serving a population of approximately 1,758 residents. The plant is situated in the central part of the state, within Marathon County, and provides essential sanitation services to the community. The facility employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 1,332.46 million gallons per day and a current discharge volume of 999.35 million gallons per day, the plant operates well within its capacity. As a US facility, it is subject to the Clean Water Act and National Pollutant Discharge Elimination System (NPDES) permitting, typically administered by the Wisconsin Department of Natural Resources. The treated effluent is discharged into a local receiving water body, which ultimately drains into the Wisconsin River and then the Mississippi River system. This downstream connection highlights the plant's role in protecting water quality in the Mississippi River Basin, a major ecological and economic resource. The advanced treatment level helps minimize nutrient loading and supports aquatic life in the receiving waters.

The plant discharges into a local waterway that flows into the Wisconsin River, a tributary of the Mississippi River. The Mississippi River Basin supports diverse aquatic ecosystems and is a critical migratory corridor for fish and birds. Advanced treatment at this plant reduces nutrient pollution, helping to mitigate downstream hypoxia in the Gulf of Mexico.