Glenwood STP and Collection | Secondary Wastewater Treatment in Glenwood, Washington

Glenwood STP and Collection is a municipal wastewater treatment facility located in Glenwood, Klickitat County, Washington, United States. The plant serves a small population of 808 residents and provides secondary treatment, which is the minimum standard required by the US Clean Water Act for municipal wastewater. Its designed capacity is 378.54 megaliters, and it treats an annual discharge volume of 208.20 megaliters. As a secondary treatment plant, Glenwood STP meets the regulatory requirements for biological treatment of organic matter and suspended solids. Under the US Clean Water Act, such facilities are typically permitted through the National Pollutant Discharge Elimination System (NPDES), administered by the Washington State Department of Ecology. The plant's scale places it in the small community category, where operational focus is on maintaining compliance with state water quality standards. The plant's treated effluent is discharged into a local waterway within the Columbia River basin. The Columbia River system is a major ecological and economic resource in the Pacific Northwest, supporting salmon runs, irrigation, and hydroelectric power. Downstream, the river flows to the Pacific Ocean, making the plant's discharge quality important for both local aquatic life and regional water quality.

Glenwood STP discharges into a tributary of the Columbia River, which flows through the Columbia River Gorge and ultimately reaches the Pacific Ocean. The Columbia River basin supports diverse aquatic ecosystems, including critical salmon and steelhead habitats. The plant's secondary treatment helps protect these downstream environments from excessive nutrient loading and organic pollution, which is vital for maintaining water quality in a region known for its ecological significance.