Aurora STP - Secondary Wastewater Treatment in Marion County, Oregon

Aurora STP is a municipal wastewater treatment plant located in Marion County, Oregon, serving a small community of 970 residents. The facility operates under the regulatory framework of the U.S. Clean Water Act, which requires secondary treatment for municipal plants discharging to surface waters. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 299.05 million gallons per day and an actual discharge volume of 94.64 million gallons per day, the facility operates well within its capacity, ensuring reliable treatment for the local population. The treated effluent is discharged into nearby streams that flow into the Willamette River, a major tributary of the Columbia River. This river system supports diverse aquatic life and is an important ecological corridor in the Pacific Northwest. The plant's operations help protect water quality in this sensitive watershed.

The plant discharges into local tributaries of the Willamette River, which flows north through Oregon's Willamette Valley before joining the Columbia River. The Willamette River basin supports salmon, steelhead, and other native fish species, making water quality protection critical. The region's agricultural and urban land uses require effective wastewater treatment to prevent nutrient pollution and maintain ecosystem health.