ONSLOW WWTP - Secondary Wastewater Treatment in Jones County, Iowa

ONSLOW WWTP is a municipal wastewater treatment facility located in Jones County, Iowa, United States. The plant serves a small population of 216 residents, reflecting its role in a rural community. It operates under secondary treatment standards, which is the minimum required by the US Clean Water Act for municipal plants. The plant has a designed capacity of 113.56 units and currently processes 75.71 units of wastewater daily, indicating it operates below its full capacity. As a US facility, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Iowa Department of Natural Resources, which set effluent limits to protect water quality. The treated effluent is discharged into a local water body, likely a tributary of the Wapsipinicon River or the Maquoketa River, both of which flow into the Mississippi River. The Mississippi River system supports diverse aquatic life and is a major migratory corridor for birds and fish. The plant's secondary treatment helps reduce organic pollutants and suspended solids before discharge.

The plant discharges into a local stream that drains into the Mississippi River basin, ultimately reaching the Gulf of Mexico. The region's watershed supports agricultural runoff and natural habitats, making nutrient management important. The Mississippi River downstream provides critical habitat for fish and migratory birds, and its delta faces hypoxia issues linked to nutrient loading.