Bay City STP - Idaville, Oregon Wastewater Treatment Plant

Bay City STP is a municipal wastewater treatment plant located in Idaville, Tillamook County, Oregon, serving a small community of 1,295 residents. The plant operates under the U.S. Clean Water Act, which requires secondary treatment for municipal discharges to protect water quality. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. Its designed capacity is 794.93 million gallons per year, with an actual discharge volume of 454.25 million gallons per year, indicating operational headroom. The treated effluent is discharged into a local water body that drains to the Pacific Ocean via the Tillamook Bay estuary. This coastal environment supports salmon runs, shellfish beds, and migratory birds, making water quality management critical for ecological health.

The plant discharges into a tributary of the Tillamook Bay, which flows into the Pacific Ocean. The bay is an ecologically productive estuary that supports diverse aquatic life, including salmon and steelhead, and provides critical habitat for migratory waterfowl. The coastal location means that nutrient and pathogen removal is important to protect downstream marine ecosystems and shellfish harvesting areas.