Hartley WWTP - Secondary Treatment Plant in Hartley, Iowa

Hartley WWTP is a municipal wastewater treatment facility located in Hartley, Iowa, United States. The plant serves a population of approximately 1,672 residents, classifying it as a small-scale treatment facility within the state's wastewater infrastructure. The plant provides secondary treatment, which is the standard level required by the US Clean Water Act for municipal wastewater. With a designed capacity of 3,141.88 thousand cubic meters, the plant operates at about 30% capacity utilization based on the annual discharge volume of 957.71 thousand cubic meters. As a facility in the US, it operates under the National Pollutant Discharge Elimination System (NPDES) permit program, which sets effluent limits to protect water quality. The treated effluent is discharged into a local water body within the Mississippi River basin. The plant's location in rural Iowa means its discharge supports local streams and rivers that eventually flow to the Mississippi River and the Gulf of Mexico. Proper treatment helps reduce nutrient loading and protects downstream aquatic ecosystems.

The plant discharges into a tributary of the Little Sioux River, which flows into the Missouri River and eventually the Mississippi River and Gulf of Mexico. The receiving waters support diverse aquatic life and are part of an important migratory corridor for fish. Nutrient management is critical in this region to minimize downstream impacts on the Gulf of Mexico hypoxic zone.