S Frk Coeur D Alene Rvr SD Mullan, Mullan

Overview

S Frk Coeur D Alene Rvr SD Mullan is a secondary treatment plant serving 692 people in Mullan, Idaho. It discharges treated wastewater into the South Fork Coeur d'Alene River, a key tributary of the Coeur d'Alene Lake system.

S Frk Coeur D Alene Rvr SD Mullan is a municipal wastewater treatment facility located in Mullan, Idaho, within the Coeur d'Alene River watershed. The plant serves a small community of 692 residents in this mountainous region of the Idaho Panhandle. As a secondary treatment plant, it provides biological treatment to reduce organic pollutants and suspended solids before discharge. The plant has a designed capacity of 567.81 cubic meters per day and currently handles an average daily flow of 492.10 cubic meters. Under the U.S. Clean Water Act, the facility operates under a National Pollutant Discharge Elimination System (NPDES) permit issued by the Idaho Department of Environmental Quality, which sets effluent limits to protect water quality in the receiving stream. The treated effluent is discharged into the South Fork Coeur d'Alene River, which flows into the main stem Coeur d'Alene River and eventually into Coeur d'Alene Lake. This lake is a major recreational and ecological resource in northern Idaho, supporting diverse aquatic life and serving as a critical habitat for fish species such as westslope cutthroat trout.

Environmental context

The plant discharges into the South Fork Coeur d'Alene River, a headwater stream that flows into the Coeur d'Alene River and then into Coeur d'Alene Lake. The lake is a large, deep lake that drains into the Spokane River, ultimately reaching the Columbia River and the Pacific Ocean. The watershed is historically impacted by mining activities, making nutrient and metal removal important for downstream water quality. The region supports diverse aquatic ecosystems, including cold-water fisheries and migratory bird habitats.

Frequently asked questions

The plant is located along the Trail of the Coeur d'Alenes in Mullan, Shoshone County, Idaho, United States.

The plant serves a population of 692 people in the Mullan area.

The plant discharges treated effluent into the South Fork Coeur d'Alene River, which flows into the Coeur d'Alene River and then into Coeur d'Alene Lake.

The plant operates under the U.S. Clean Water Act and is subject to an NPDES permit issued by the Idaho Department of Environmental Quality, which sets effluent limits for secondary treatment.

For small communities in the U.S., secondary treatment is standard, providing biological treatment to reduce BOD and suspended solids. Many such plants also incorporate disinfection and nutrient removal depending on local water quality requirements.