Little Rock WWTP, Lyon County, Iowa: Secondary Treatment for a Rural Community

Little Rock WWTP is a municipal wastewater treatment facility located in Lyon County, Iowa, United States. It serves a small population of 157 residents, reflecting its role in a rural community. The plant is situated near 140th Street in the northwestern part of the state, close to the Minnesota border. The facility provides secondary treatment, which is the standard biological treatment process required by the U.S. Clean Water Act for municipal wastewater. With a designed capacity of 211.98 and a discharge volume of 196.84, the plant operates efficiently within its capacity. Under the National Pollutant Discharge Elimination System (NPDES), plants of this scale must meet effluent limits to protect water quality. The treated effluent is discharged into local streams that drain into the Rock River, a tributary of the Big Sioux River, which ultimately flows into the Missouri River. This watershed supports diverse aquatic life and is important for regional agriculture and recreation. The plant's operation helps maintain the ecological health of these downstream water bodies.

The plant discharges into the Rock River watershed, which flows into the Big Sioux River and then the Missouri River. This river system supports a variety of fish and wildlife, including migratory birds and aquatic species. The region's agricultural landscape means that nutrient management is critical to prevent eutrophication in downstream waters.