Pullman STP - Wastewater Treatment Plant in Pullman, Washington

Pullman STP is a municipal wastewater treatment facility located in Pullman, Washington, serving a population of about 46,820. The plant is situated in Whitman County, within the Palouse region, and is part of the city's essential infrastructure for managing domestic and commercial wastewater. As a medium-sized agglomeration, the plant is expected to meet secondary treatment standards under the U.S. Clean Water Act. The National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Washington State Department of Ecology, governs its discharge limits and monitoring requirements to ensure compliance with federal and state regulations. The treated effluent is discharged into the local watershed, which ultimately drains to the Snake River and then the Columbia River, a major Pacific Northwest waterway. The plant's operations are critical for protecting downstream aquatic ecosystems, including fish habitats and recreational waters, from nutrient pollution and pathogens.

Pullman STP discharges into the South Fork Palouse River, a tributary of the Palouse River, which flows into the Snake River and then the Columbia River before reaching the Pacific Ocean. The watershed supports diverse aquatic life, including salmonid species, and is important for regional agriculture and recreation. Proper treatment helps prevent eutrophication and maintains water quality in this sensitive river system.