Hoquiam Wastewater Treatment Plant - Coastal Facility in Grays Harbor, Washington

The Hoquiam Wastewater Treatment Plant is a municipal facility serving the city of Hoquiam, Washington, located on Moon Island Road at the Port of Grays Harbor. With a population served of 8,650, it is classified as a small-to-medium agglomeration under U.S. regulatory frameworks. The plant is situated in Grays Harbor County, a coastal region in the Pacific Northwest. As a U.S. facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Washington State Department of Ecology. Plants of this scale typically employ secondary treatment to meet federal and state standards for organic and solids removal. The designed capacity is 1.00 million gallons per day, indicating the plant's scale. The plant discharges treated wastewater into Grays Harbor, an estuary that connects to the Pacific Ocean. This water body supports diverse aquatic life, including salmon runs and migratory birds. The estuary is ecologically sensitive, and the plant's discharge must comply with water quality standards to protect downstream habitats and recreational uses.

The plant discharges into Grays Harbor, a large estuary on the Washington coast that receives freshwater from the Chehalis River and other tributaries before flowing into the Pacific Ocean. The estuary supports critical habitats for salmon, steelhead, and migratory shorebirds. As a coastal water body, it is subject to tidal influences and requires careful management of nutrients and pollutants to prevent eutrophication and protect marine life.