Prairie City STP - Secondary Wastewater Treatment Plant in Prairie City, Oregon

Prairie City STP (Sewage Treatment Plant) serves the community of Prairie City, Oregon, a small town in Grant County. The plant provides secondary treatment for a population of approximately 1,145 residents, handling an average daily flow of 465.61 cubic meters with a designed capacity of 681.37 cubic meters. As a secondary treatment facility, Prairie City STP meets the standard requirements under the U.S. Clean Water Act, which mandates secondary treatment for municipal wastewater plants. The plant's operations are likely regulated under an EPA NPDES permit issued by the Oregon Department of Environmental Quality, ensuring compliance with discharge limits. The treated effluent from Prairie City STP is discharged into a local waterway that ultimately drains into the John Day River, a major tributary of the Columbia River. The John Day River basin supports diverse aquatic life, including salmon and steelhead, making water quality protection critical for downstream ecosystems.

Prairie City STP discharges into a local stream that flows into the John Day River, which joins the Columbia River. The John Day River basin is an important habitat for native fish species, including Chinook salmon and steelhead trout. Maintaining high water quality in this watershed is essential for supporting these migratory fish and the broader riverine ecosystem.