SANDY STP Wastewater Treatment Plant, Clackamas County, Oregon

SANDY STP is a municipal wastewater treatment plant located in Clackamas County, Oregon, serving a population of approximately 6,240 residents. The facility is part of the region's wastewater infrastructure, managing flows from the Sandy area and surrounding communities. Under the U.S. Clean Water Act, plants of this scale are typically required to meet secondary treatment standards through National Pollutant Discharge Elimination System (NPDES) permits issued by the Oregon Department of Environmental Quality. These permits set effluent limits to protect water quality in receiving streams. The treated effluent from SANDY STP is discharged to local tributaries that flow into the Sandy River, a major tributary of the Columbia River. The Sandy River supports salmon and steelhead runs and is an important ecological corridor in the Pacific Northwest.

The plant's discharge enters a local watercourse that drains into the Sandy River, which flows into the Columbia River and ultimately reaches the Pacific Ocean. The Sandy River watershed supports diverse aquatic life, including threatened salmonid species, and is a key migratory route for anadromous fish. The region's forested landscape and seasonal rainfall influence runoff patterns and water quality.