MITCHELL STP - Secondary Wastewater Treatment Plant in Mitchell, Oregon

MITCHELL STP is a municipal wastewater treatment plant located in Mitchell, Oregon, United States. The facility serves a small population of 270 residents in this rural community within Wheeler County. As a secondary treatment plant, it provides biological treatment to reduce organic matter and suspended solids before discharge. The plant's designed capacity is 102.21 volume units, with a corresponding discharge volume of 102.21, indicating full utilization of its capacity. Under the U.S. Clean Water Act, such facilities operate under National Pollutant Discharge Elimination System (NPDES) permits issued by the Oregon Department of Environmental Quality, which set effluent limits to protect water quality. The treated effluent is discharged into a local water body, likely a tributary of the John Day River, which flows into the Columbia River and ultimately the Pacific Ocean. The plant plays a key role in protecting the region's water resources, supporting aquatic life and downstream uses.

The plant discharges into a local watercourse that drains into the John Day River basin, a major tributary of the Columbia River. The John Day River is known for its diverse aquatic habitat, including salmon and steelhead runs. The downstream environment includes the Columbia River estuary and the Pacific Ocean, making proper wastewater treatment critical for maintaining water quality and ecosystem health.