COLESBURG SE STL Wastewater Treatment Plant, Colesburg, Iowa

COLESBURG SE STL is a municipal wastewater treatment facility located in Colesburg, Delaware County, Iowa. The plant serves a small population of 272 residents, reflecting the rural character of the community. It is situated inland, far from coastal waters, and its operations are governed by the US Clean Water Act. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 75.71 units and a discharge volume matching that figure, the facility operates at full capacity. Under the US EPA's National Pollutant Discharge Elimination System (NPDES), plants of this scale are required to meet effluent limits that protect local water quality. The treated effluent is discharged into a nearby water body, likely a stream or river within the Mississippi River basin. Iowa's waterways ultimately drain to the Mississippi River and the Gulf of Mexico. The plant's secondary treatment helps reduce nutrient loads, contributing to downstream efforts to mitigate hypoxia in the Gulf.

The plant discharges into a local water body that flows into the Mississippi River basin, eventually reaching the Gulf of Mexico. This region is part of the Upper Mississippi River watershed, which supports diverse aquatic life and is a critical migratory corridor for birds. Downstream, nutrient pollution from wastewater and agriculture contributes to seasonal hypoxia in the Gulf, making effective treatment essential for ecosystem health.