HURLEY STP - Secondary Wastewater Treatment in Turner County, South Dakota

HURLEY STP is a municipal wastewater treatment plant located in Hurley Township, Turner County, South Dakota, United States. The facility serves a small population of 372 residents, reflecting its role in a rural community. As a secondary treatment plant, it provides biological treatment to reduce organic matter and suspended solids before discharge. The plant operates under the U.S. Clean Water Act, which requires National Pollutant Discharge Elimination System (NPDES) permits for all wastewater discharges. For small agglomerations like this, secondary treatment is the standard requirement. The plant's designed capacity is 189.27 megaliters, and it treats an annual discharge volume of 113.56 megaliters, indicating moderate capacity utilization. The treated effluent is discharged into local waterways that drain into the Missouri River basin, ultimately reaching the Gulf of Mexico. The plant plays a key role in protecting local water quality in the Big Sioux River watershed, supporting aquatic life and downstream ecosystems.

The plant discharges into tributaries of the Big Sioux River, which flows into the Missouri River and eventually the Mississippi River and Gulf of Mexico. The surrounding area is primarily agricultural, so the plant helps reduce nutrient loading that could contribute to hypoxia in the Gulf. The local watershed supports diverse aquatic species and is an important resource for irrigation and recreation.