Shoreline Sanitary District STP - Advanced Wastewater Treatment in Clatsop County, Oregon

Shoreline Sanitary District STP is a wastewater treatment facility located in Clatsop County, Oregon, United States. The plant serves a small population of 350 residents and operates with advanced treatment processes, ensuring high-quality effluent. Its designed capacity is 189.27 million gallons per year, with a current discharge volume of 87.06 million gallons per year. The plant provides advanced treatment, which goes beyond secondary treatment to remove nutrients and other pollutants. Under the U.S. Clean Water Act, such facilities must comply with National Pollutant Discharge Elimination System (NPDES) permits issued by the Oregon Department of Environmental Quality. These permits set strict limits on effluent quality to protect receiving waters. The treated wastewater is discharged into the local watershed, which ultimately drains to the Pacific Ocean via the Columbia River estuary. The coastal location means the plant's discharge can affect sensitive marine ecosystems, including nearshore habitats and migratory fish populations. Advanced treatment helps minimize environmental impact.

The plant discharges into a watershed that flows to the Columbia River estuary and then to the Pacific Ocean. This coastal region supports diverse aquatic life, including salmon and steelhead, which are sensitive to nutrient loading and pollutants. The advanced treatment helps protect these downstream ecosystems from eutrophication and toxic effects.