Overview
Soap Lake STP is a secondary treatment plant serving approximately 1,735 residents in Soap Lake, Washington. It discharges treated wastewater into the local watershed, supporting water quality in the region.
Soap Lake STP is a municipal wastewater treatment facility located in Soap Lake, Washington, a small community in Grant County. The plant serves a population of about 1,735 people, reflecting its role as a key infrastructure component for this rural area. The plant provides secondary treatment, which is the standard level required under the U.S. Clean Water Act for municipal facilities. With a designed capacity of 681.37 cubic meters per day and an average discharge volume of 643.52 cubic meters per day, it operates near its design capacity, ensuring effective treatment of local wastewater. The treated effluent is discharged into the local watershed, which ultimately drains into the Columbia River Basin. This discharge supports the ecological health of downstream water bodies, including the Columbia River, which is vital for regional aquatic life and water supply.
Environmental context
The plant's discharge enters the Soap Lake area, part of the larger Columbia River Basin. The receiving waters support diverse aquatic ecosystems, including fish species such as salmon and trout. Maintaining secondary treatment helps protect water quality in this semi-arid region, where water resources are critical for both ecological and human uses.
Frequently asked questions
Soap Lake STP is located in Soap Lake, Washington, United States, in Grant County. The facility serves the local community.
The plant serves approximately 1,735 residents, making it a small-scale municipal wastewater treatment facility.
The plant discharges treated effluent into the local watershed, which flows into the Columbia River Basin. The discharge supports downstream water quality.
As a U.S. facility, Soap Lake STP operates under the Clean Water Act, with National Pollutant Discharge Elimination System (NPDES) permits issued by the Washington State Department of Ecology.
For small communities like Soap Lake, secondary treatment is standard under the Clean Water Act. This level effectively removes organic matter and suspended solids to protect receiving waters.
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