CASTLEFORD STP - Secondary Wastewater Treatment in Twin Falls County, Idaho

CASTLEFORD STP is a wastewater treatment facility located in Twin Falls County, Idaho, United States. The plant serves a small population of 226 residents, reflecting its role in a rural or small community setting within the state. The plant provides secondary treatment, a standard level of purification that removes biodegradable organic matter and suspended solids. With a designed capacity of 151.42 units and a current discharge volume of 75.71 units, the facility operates below its maximum capacity. Under the U.S. Clean Water Act, such plants are typically regulated through National Pollutant Discharge Elimination System (NPDES) permits issued by the Idaho Department of Environmental Quality, ensuring compliance with water quality standards. The treated effluent is discharged into a local water body, likely a tributary of the Snake River basin, which ultimately drains into the Columbia River and the Pacific Ocean. The plant's operations help protect downstream aquatic ecosystems and support water quality in the region's agricultural and natural landscapes.

The plant discharges into a local watercourse within the Snake River basin, which flows into the Columbia River and then the Pacific Ocean. The surrounding area is characterized by agricultural land and the Snake River Plain, where water quality is important for irrigation and wildlife. The plant's secondary treatment helps reduce nutrient and organic loads, supporting the ecological health of downstream waters.