ROYAL WSP Wastewater Treatment Plant, Clay County, Iowa

ROYAL WSP is a municipal wastewater treatment plant located on 400th Street in Clay County, Iowa, United States. The facility serves a small population of 466 residents, reflecting its role in a rural community within the state's agricultural landscape. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 264.98 megaliters and an annual discharge volume of 151.42 megaliters, the plant operates within its capacity. As a U.S. facility, it is subject to the Clean Water Act and National Pollutant Discharge Elimination System (NPDES) permitting, which sets effluent limits to protect water quality. The treated effluent is discharged into local waterways that drain into the Missouri River basin, ultimately reaching the Mississippi River and the Gulf of Mexico. The plant's operation helps protect downstream aquatic ecosystems and supports water quality in the region's agricultural watershed.

The plant discharges into streams within the Missouri River basin, which flows into the Mississippi River and then the Gulf of Mexico. This watershed supports diverse aquatic life and is important for migratory birds. The surrounding area is primarily agricultural, so the plant's nutrient removal helps reduce downstream eutrophication risks in the Gulf of Mexico hypoxic zone.