ATALISSA STL Wastewater Treatment Plant, Muscatine County, Iowa

ATALISSA STL is a municipal wastewater treatment plant located in Muscatine County, Iowa, United States. The plant serves a small population of 357 residents, reflecting its role in a rural or small community setting within the state. The plant provides secondary treatment, which is the standard level required under the US Clean Water Act for most municipal facilities. Secondary treatment typically involves biological processes to remove organic matter and suspended solids. The plant's designed capacity matches its discharge volume at 113.56 units, indicating consistent operation at capacity. The treated effluent is discharged into local waterways that ultimately drain into the Mississippi River basin. The Mississippi River system supports diverse aquatic life and is a major migratory corridor for birds and fish. The plant's operations are subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Iowa Department of Natural Resources, ensuring compliance with water quality standards.

The plant discharges into local streams that flow into the Mississippi River, one of the largest river systems in North America. The Mississippi River basin supports a wide range of aquatic species and provides critical habitat for migratory birds. Downstream, the river drains into the Gulf of Mexico, where nutrient loading from upstream sources can contribute to hypoxic zones. The plant's secondary treatment helps reduce organic pollutants but may not fully address nutrient removal, which is a concern for the broader watershed.