Kimballton STL Wastewater Treatment Plant, Kimballton, Iowa

Kimballton STL is a municipal wastewater treatment plant located in Kimballton, a small town in Audubon County, Iowa, United States. The plant serves a population of 289 residents, reflecting the rural character of the community. The plant provides secondary treatment, which is the standard level required under the U.S. Clean Water Act for municipal wastewater facilities. With a designed capacity of 189.27 megaliters and an annual discharge volume of 151.42 megaliters, the plant operates below its design capacity. As a U.S. facility, it operates under a National Pollutant Discharge Elimination System (NPDES) permit issued by the Iowa Department of Natural Resources, ensuring compliance with federal water quality standards. The treated effluent is discharged into a local waterway that ultimately drains into the Missouri River basin. The plant plays a key role in protecting downstream water quality in the region, which supports agricultural and ecological uses.

The plant discharges into a tributary of the Nishnabotna River, which flows into the Missouri River and eventually the Mississippi River. This watershed supports diverse aquatic life and is an important corridor for migratory birds. The region's agricultural landscape means that nutrient management is critical to prevent downstream eutrophication.