MORTON STP - Secondary Wastewater Treatment Plant in Morton, Washington

MORTON STP is a municipal wastewater treatment plant located in Morton, Lewis County, Washington, United States. The facility serves a population of approximately 1,125 residents, classifying it as a small-scale treatment operation within the state's wastewater infrastructure. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal wastewater facilities. Under the National Pollutant Discharge Elimination System (NPDES), plants of this scale are typically permitted by the Washington State Department of Ecology, ensuring compliance with effluent limits that protect water quality. The treated effluent is discharged into a local waterway within the Cowlitz River basin, which ultimately flows into the Columbia River and then to the Pacific Ocean. The plant plays a role in safeguarding downstream aquatic habitats and supporting the ecological health of the region's watershed.

The plant discharges into a tributary of the Cowlitz River, which flows into the Columbia River and then to the Pacific Ocean. The Cowlitz River basin supports diverse aquatic life, including salmon runs, and the plant's secondary treatment helps reduce nutrient and pollutant loads that could impact downstream water quality and ecosystem health.