Oconto WWTP - Secondary Wastewater Treatment Plant in Oconto, Wisconsin

Oconto WWTP is a municipal wastewater treatment facility located at 161 Main Street in Oconto, Wisconsin, United States. The plant serves a population of approximately 6,063 residents and operates as a secondary treatment facility, which is the standard level required by the U.S. Clean Water Act for municipal wastewater treatment. As a secondary treatment plant, Oconto WWTP uses biological processes to remove organic matter and suspended solids from wastewater. The plant has a designed capacity of 6,851.57 thousand cubic meters and currently discharges 859.29 thousand cubic meters annually, indicating significant available capacity. Under the U.S. National Pollutant Discharge Elimination System (NPDES), the plant is required to meet effluent limits that protect water quality in the receiving water body. The plant is located within 10 kilometers of the coast, meaning its treated effluent likely discharges into a water body that flows into Lake Michigan or Green Bay. This proximity to the Great Lakes places the plant in a sensitive environmental context, as the lakes are a vital freshwater resource supporting diverse aquatic life and providing drinking water for millions. The plant's operations are regulated to minimize nutrient and pollutant loading into this important ecosystem.

Oconto WWTP discharges treated wastewater into a water body that ultimately flows into Green Bay, an arm of Lake Michigan. Lake Michigan is part of the Great Lakes system, which holds 21% of the world's surface freshwater and supports a rich aquatic ecosystem, including native fish species and migratory birds. The plant's coastal location means its effluent can influence nearshore water quality, making nutrient management and pathogen control critical for protecting recreational uses and aquatic habitats.