ST PAUL STP Wastewater Treatment Plant, St. Paul, Iowa

ST PAUL STP is a municipal wastewater treatment facility located in St. Paul, Iowa, United States. The plant serves a small community of approximately 150 residents, reflecting its role in a rural setting. As a secondary treatment plant, it meets the standard requirements for organic matter and suspended solids removal under the U.S. Clean Water Act. The plant has a designed capacity of 37.85 cubic meters per day, matching its discharge volume. Secondary treatment typically involves biological processes such as activated sludge or trickling filters. The facility operates under the National Pollutant Discharge Elimination System (NPDES) permit program, which sets effluent limits to protect water quality. The treated wastewater is discharged into a local waterway, contributing to the Mississippi River basin. The plant's operations help maintain the ecological health of downstream waters, supporting aquatic life and recreational uses. Its inland location reduces direct marine impact, but careful management is essential to prevent nutrient loading in the watershed.

The plant discharges into a tributary of the Mississippi River, which ultimately flows to the Gulf of Mexico. The local watershed supports diverse aquatic habitats and is part of a larger system affected by agricultural runoff. The plant's secondary treatment helps reduce organic pollutants, but nutrient removal may be limited, contributing to downstream eutrophication concerns.