Wall Lake STL Wastewater Treatment Plant, Wall Lake, Iowa

Wall Lake STL is an advanced wastewater treatment plant located in Wall Lake, Iowa, serving a population of 840. The plant is situated in Sac County and is part of the municipal infrastructure for the community. The plant provides advanced treatment, which goes beyond secondary treatment to remove nutrients and other pollutants. It has a designed capacity of 416.39 thousand cubic meters and discharges 605.67 thousand cubic meters annually. As a US facility, it operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Iowa Department of Natural Resources. The treated effluent is discharged into local waterways that ultimately drain into the Mississippi River basin. The plant's advanced treatment helps protect downstream water quality and aquatic ecosystems in the region.

The plant discharges into local streams that flow into the North Raccoon River, a tributary of the Des Moines River, which eventually reaches the Mississippi River. This watershed supports diverse aquatic life and is important for regional water supply. Advanced treatment at this plant helps reduce nutrient loading, protecting downstream habitats from eutrophication.