Central Lake STP - Secondary Wastewater Treatment in Central Lake Township, Michigan

Central Lake STP is a municipal wastewater treatment facility located in Central Lake Township, Antrim County, Michigan. The plant serves a small population of 860 residents, providing secondary treatment to meet state and federal water quality standards. Its location in the northern Lower Peninsula places it within a region of inland lakes and streams that drain toward Lake Michigan. The plant operates with a secondary treatment process, which is the minimum standard required under the U.S. Clean Water Act for municipal wastewater facilities. With a designed capacity of 416.39 megaliters per year and an actual discharge volume of 227.13 megaliters, the plant operates well below its capacity, indicating room for future growth or seasonal flow variations. The facility is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Michigan Department of Environment, Great Lakes, and Energy (EGLE). Treated effluent from Central Lake STP is discharged to a local water body that ultimately drains into Lake Michigan, one of the largest freshwater lakes in the world. The plant plays a critical role in protecting the water quality of the Great Lakes basin, supporting aquatic life, recreational use, and drinking water supplies downstream.

The plant discharges into a local stream or lake within the Lake Michigan watershed. Lake Michigan supports a diverse ecosystem, including native fish species such as lake trout and whitefish, and provides drinking water for millions. The plant's secondary treatment helps reduce nutrient loading and pathogen levels, protecting downstream water quality and recreational uses like swimming and fishing.