Donnellson STP Wastewater Treatment Plant, Donnellson, Iowa

Donnellson STP is a municipal wastewater treatment plant located in Donnellson, Lee County, Iowa. The facility serves a population of approximately 940 residents, classifying it as a small community system under U.S. regulatory frameworks. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal wastewater. With a designed capacity of 1,192.40 megaliters and an annual discharge volume of 567.81 megaliters, the facility operates within its capacity. As a U.S. plant, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Iowa Department of Natural Resources, ensuring compliance with effluent limits. The treated effluent is discharged into a local water body that ultimately drains into the Mississippi River basin. This watershed supports diverse aquatic life and provides drinking water for downstream communities. The plant's operation helps protect water quality in the region's streams and rivers.

The plant discharges into a tributary of the Mississippi River, which flows south to the Gulf of Mexico. The local watershed supports agricultural and ecological resources, including fish and wildlife habitats. Proper treatment is essential to prevent nutrient loading and protect downstream water quality in this major river system.