Michigan City STP - Wastewater Treatment Plant in Michigan City, Indiana

Michigan City STP is a municipal wastewater treatment facility located in Michigan City, Indiana, serving a population of approximately 32,900. The plant is situated near the southern shore of Lake Michigan, within the Great Lakes Basin, one of the largest freshwater systems in the world. As a U.S. facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Indiana Department of Environmental Management. For a population of this scale, secondary treatment is typically required, with additional nutrient removal standards applicable to Great Lakes states to address eutrophication concerns. The plant's treated effluent ultimately drains into Lake Michigan, which supplies drinking water to millions and supports diverse aquatic life, including native fish species and migratory birds. The Great Lakes ecosystem is sensitive to nutrient loading and contaminants, making effective wastewater treatment critical for water quality and ecological health.

Michigan City STP discharges into the Lake Michigan watershed, part of the Great Lakes Basin. Lake Michigan is a major freshwater resource that supports drinking water, recreation, and a complex aquatic ecosystem. The plant's location within 50 km of the coast underscores its influence on nearshore water quality, where nutrient inputs can contribute to algal blooms and habitat degradation.