HEPPNER STP - Secondary Wastewater Treatment Plant in Heppner, Oregon

HEPPNER STP is a municipal wastewater treatment plant located at 698 Riverside Avenue in Heppner, Morrow County, Oregon. The facility serves a population of approximately 1,290 residents and operates under the regulatory framework of the U.S. Clean Water Act, which requires secondary treatment for municipal discharges to surface waters. The plant provides secondary treatment, a standard level for small communities in the United States. With a designed capacity of 946.35 m³/day and an average daily discharge of 340.69 m³/day, the facility operates well below its capacity, indicating room for future growth. The plant's discharge is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Oregon Department of Environmental Quality. The treated effluent is discharged to a receiving water body, likely a tributary of the Columbia River basin. The plant's inland location, over 50 km from the coast, means its discharge affects freshwater ecosystems rather than marine environments. The facility plays a key role in protecting local water quality in the semi-arid region of eastern Oregon.

HEPPNER STP discharges into a local watercourse that flows into the Columbia River system, ultimately reaching the Pacific Ocean. The receiving waters support aquatic life and are used for irrigation and recreation. The plant's secondary treatment helps reduce organic pollutants and suspended solids, protecting downstream habitats in the Columbia Basin.