Sand Dunes WWTP, Grant County

Overview

Sand Dunes WWTP serves 16,836 people in Grant County, Washington. The plant operates under the US Clean Water Act, with NPDES permits regulating its discharge to protect local water quality.

Sand Dunes WWTP is a municipal wastewater treatment facility located in Grant County, Washington, serving a population of approximately 16,836. The plant is situated inland in the Columbia River basin, an arid region of the Pacific Northwest. As a medium-sized agglomeration, it plays a key role in managing wastewater for the surrounding community. Under the US Clean Water Act, the plant is required to meet secondary treatment standards and operate under a National Pollutant Discharge Elimination System (NPDES) permit issued by the Washington State Department of Ecology. These permits set effluent limits to protect receiving waters. Facilities of this scale typically employ biological treatment followed by disinfection. The plant's treated effluent is discharged into the Columbia River watershed, which flows to the Pacific Ocean. The Columbia River supports diverse aquatic life, including salmon runs, and is a critical water resource for irrigation, recreation, and hydropower in the region. Proper treatment helps maintain water quality in this ecologically significant basin.

Environmental context

Sand Dunes WWTP discharges into the Columbia River basin, which drains into the Pacific Ocean via the Columbia River estuary. The watershed supports important salmon and steelhead populations, as well as other native fish species. The region's semi-arid climate means water quality is especially sensitive to nutrient loading and pollutants, making effective wastewater treatment essential for maintaining ecological balance.

Frequently asked questions

Sand Dunes WWTP is located at 11015 Baseline Road East, Grant County, Washington, in the United States.

The plant serves approximately 16,836 people in the Grant County area.

The plant discharges treated effluent into the Columbia River basin, which ultimately flows to the Pacific Ocean. Discharge is regulated under an NPDES permit to protect water quality.

The plant operates under the US Clean Water Act, which requires NPDES permits for wastewater discharges. Washington State Department of Ecology oversees compliance with secondary treatment standards and effluent limits.

For a plant of this scale, typical treatment includes primary sedimentation followed by biological secondary treatment (such as activated sludge or trickling filters) and disinfection. Advanced nutrient removal may be required if the receiving water is sensitive.