Overview
Montesano WWPCP serves 3,232 people in Montesano, Washington, discharging treated wastewater into the Chehalis River basin. The plant operates under the US Clean Water Act NPDES permit program.
Montesano WWPCP is a municipal wastewater treatment facility located in Montesano, Grays Harbor County, Washington. The plant serves a population of approximately 3,232 residents, placing it in the small community category for US wastewater infrastructure. As a US facility, the plant operates under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Washington State Department of Ecology. The plant has a designed capacity of 1.00 million gallons per day, indicating it is sized for modest flows. The plant discharges into the Chehalis River basin, which flows westward through Grays Harbor County before emptying into Grays Harbor estuary and the Pacific Ocean. The Chehalis River supports diverse aquatic life, including salmon runs, and the estuary provides critical habitat for migratory birds and marine species.
Environmental context
The Chehalis River basin drains the Olympic Mountains and flows through agricultural and forested lands before reaching Grays Harbor, a large estuary on the Washington coast. This estuary is a vital nursery for juvenile salmon and supports a rich ecosystem of shellfish, birds, and marine mammals. The plant's discharge contributes to the river's flow, which ultimately reaches the Pacific Ocean, making nutrient and pollutant management important for downstream water quality.
Frequently asked questions
Montesano WWPCP is located on South Main Street in Montesano, Grays Harbor County, Washington, United States.
The plant serves a population of 3,232 residents in the Montesano area.
The plant discharges treated wastewater into the Chehalis River basin, which flows into Grays Harbor estuary and eventually the Pacific Ocean.
As a US facility, it operates under the Clean Water Act via an NPDES permit issued by the Washington State Department of Ecology, which sets discharge limits for pollutants.
Small communities in Washington typically use secondary treatment processes such as activated sludge or lagoons, followed by disinfection, to meet NPDES permit requirements.
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