Fort Atkinson STP - Wastewater Treatment Plant in Town of Koshkonong, Wisconsin

Fort Atkinson STP is a municipal wastewater treatment facility located in the Town of Koshkonong, Jefferson County, Wisconsin. It serves a population of approximately 12,151 residents, classifying it as a medium-sized agglomeration under U.S. regulatory standards. As a U.S. facility, the plant operates under the Clean Water Act, administered through the National Pollutant Discharge Elimination System (NPDES) permit program. The Wisconsin Department of Natural Resources typically issues permits for such plants, setting effluent limits to protect water quality. The plant's treated effluent discharges into local waterways within the Rock River Basin, which ultimately flows into the Mississippi River. This watershed supports diverse aquatic life and provides habitat for fish and migratory birds. The plant's location inland, away from coastal areas, reduces direct marine impact, but its discharge contributes to the overall health of the regional river system.

The plant discharges into the Rock River Basin, a tributary of the Mississippi River. The Rock River flows through southern Wisconsin and northern Illinois before joining the Mississippi near the Quad Cities. This watershed supports diverse aquatic ecosystems, including fish species such as walleye and smallmouth bass, and provides important habitat for migratory waterfowl. The plant's operations are regulated to protect these downstream environments from nutrient pollution and other contaminants.