OYENS LAGOON Wastewater Treatment Plant, Plymouth County, Iowa

OYENS LAGOON is a municipal wastewater treatment facility located in Plymouth County, Iowa, serving a small population of 113 residents. The plant is situated in a rural area of the state, reflecting the decentralized wastewater infrastructure common in sparsely populated regions of the United States. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal wastewater facilities. With a designed capacity of 37.85 million gallons per year, the plant operates under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Iowa Department of Natural Resources. This regulatory framework ensures that treated effluent meets water quality standards before discharge. The treated wastewater from OYENS LAGOON is discharged into local waterways that ultimately drain into the Missouri River basin. The plant's operations help protect downstream aquatic ecosystems and maintain water quality in the region's surface waters, which support diverse wildlife and recreational uses.

The plant discharges into tributaries of the Missouri River, which flows into the Mississippi River and eventually the Gulf of Mexico. The local watershed supports agricultural runoff and natural habitats, making proper wastewater treatment essential to prevent nutrient pollution and protect downstream water quality.