Tripoli STL Wastewater Treatment Plant - Tripoli, Iowa

Tripoli STL is a municipal wastewater treatment plant located in Tripoli, Iowa, United States. The facility serves a population of 1,310 residents in this small community within Bremer County. As a secondary treatment plant, it provides biological treatment to remove organic matter and suspended solids from wastewater before discharge. The plant operates under the regulatory framework of the U.S. Clean Water Act, which requires National Pollutant Discharge Elimination System (NPDES) permits for all wastewater discharges. For small agglomerations like Tripoli, secondary treatment is the standard requirement to protect water quality. The plant's designed capacity of 2,725.49 thousand gallons per day indicates it has capacity to handle future growth, while current discharge volume is 454.25 thousand gallons per day. The treated effluent is discharged into a local water body that ultimately drains into the Mississippi River basin. The plant plays a key role in protecting downstream water quality in Iowa's streams and rivers, which support diverse aquatic life and are used for recreation and drinking water supply. By maintaining secondary treatment standards, the facility helps reduce nutrient and pollutant loads to the regional watershed.

The plant discharges into a local stream that is part of the Upper Mississippi River basin. This watershed drains into the Mississippi River, which flows to the Gulf of Mexico. The region's aquatic ecosystems support diverse fish and macroinvertebrate communities, and the plant's secondary treatment helps control nutrient pollution that could contribute to downstream hypoxia in the Gulf.