Challis Airport Lagoon System - Secondary Wastewater Treatment in Challis, Idaho

Challis Airport Lagoon System is a municipal wastewater treatment facility located near Challis, Idaho, in the United States. The plant serves a small population of 649 residents, providing secondary treatment to manage domestic wastewater from the community. The plant operates under the U.S. Clean Water Act, which requires secondary treatment for municipal wastewater. With a designed capacity of 783.58 cubic meters per day and an average discharge volume of 454.25 cubic meters per day, the facility is sized to handle the local demand. As a lagoon system, it relies on natural biological processes to treat wastewater before discharge. The treated effluent is released into the local environment, ultimately draining into the Salmon River, a major tributary of the Snake River. The Salmon River supports diverse aquatic life, including salmonid species, and is an important ecological corridor in the Pacific Northwest. The plant's inland location reduces direct marine impact, but its discharge influences the health of the river ecosystem.

The plant discharges into the Salmon River watershed, which flows into the Snake River and eventually the Columbia River, reaching the Pacific Ocean. The Salmon River is known for its cold-water fisheries, including Chinook salmon and steelhead trout, making water quality protection critical. The plant's secondary treatment helps reduce organic pollutants and suspended solids, supporting the ecological health of this important river system.