CALLENDER STL Wastewater Treatment Plant, Webster County, Iowa

CALLENDER STL is a municipal wastewater treatment plant located in Webster County, Iowa, United States. The facility serves a small population of 384 residents, reflecting its role in a rural or small-town setting. The plant is situated in the central part of the state, within the Mississippi River Basin. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal wastewater facilities. Secondary treatment typically involves biological processes to remove organic matter and suspended solids. The plant has a designed capacity of 189.27 megaliters and currently treats 151.42 megaliters annually, indicating it operates below its full capacity. The treated effluent is discharged into local waterways that ultimately drain into the Mississippi River system. This river system is ecologically significant, supporting diverse aquatic life and providing habitat for migratory fish species. The plant's discharge contributes to the overall water quality management in the region, helping to protect downstream ecosystems.

The plant discharges into tributaries of the Des Moines River, which flows into the Mississippi River. The Mississippi River is a major ecological corridor supporting diverse fish, birds, and plant species. The watershed is primarily agricultural, so the plant's nutrient removal helps mitigate eutrophication risks downstream.