Sutherland STL Wastewater Treatment Plant, Sutherland, Iowa

Sutherland STL is a municipal wastewater treatment plant located in Sutherland, O'Brien County, Iowa, United States. The facility serves a population of approximately 707 residents, providing essential sanitation services for this small rural community. The plant is situated on East 4th Street and operates under the regulatory framework of the U.S. Clean Water Act, which governs wastewater discharges through the National Pollutant Discharge Elimination System (NPDES) permit program. The plant employs secondary treatment, a standard biological process that removes organic matter and suspended solids from wastewater. With a designed capacity of 738.15 volume units and an actual discharge volume of 439.11 units, the facility operates below its maximum capacity, indicating room for future growth. As a secondary treatment plant, it meets the minimum federal requirements for municipal wastewater treatment, ensuring that effluent quality protects receiving waters. The treated effluent from Sutherland STL is discharged into a local water body, likely a stream or river within the Missouri River basin. The plant's inland location, more than 50 km from the coast, means its discharge primarily affects freshwater ecosystems. Proper treatment helps maintain the ecological health of downstream waters, supporting aquatic life and recreational uses in the region.

The plant discharges into a local waterway that flows into the Little Sioux River, a tributary of the Missouri River, which eventually reaches the Mississippi River and the Gulf of Mexico. The watershed supports diverse aquatic habitats and is important for regional biodiversity. Effective secondary treatment reduces nutrient and pollutant loads, protecting downstream water quality and minimizing impacts on sensitive freshwater ecosystems.