North Tomer Butte Lagoon Wastewater Treatment Plant, Latah County, Idaho

North Tomer Butte Lagoon is a wastewater treatment facility located in Latah County, Idaho, United States. The plant serves a small population of 250 residents, providing secondary treatment to meet local environmental standards. As a lagoon-based system, it is typical for rural communities in the region, offering a cost-effective solution for wastewater management. The plant operates under the regulatory framework of the U.S. Clean Water Act, which requires secondary treatment for municipal wastewater discharges. With a designed capacity of 79.49 units and a current discharge volume of 64.35 units, the facility operates below its capacity, indicating room for future growth. The treatment process involves biological degradation in aerated or facultative lagoons, common for small-scale systems in Idaho. The treated effluent is discharged into local waterways that eventually drain into the Palouse River basin, contributing to the Columbia River system. This watershed supports agricultural activities and provides habitat for aquatic species. The plant's inland location reduces direct marine impact, but careful management is needed to protect local water quality and downstream ecosystems.

The plant discharges into the Palouse River watershed, which flows into the Snake River and ultimately the Columbia River before reaching the Pacific Ocean. This inland basin supports diverse aquatic life, including salmonid species, and is vital for regional agriculture. The secondary treatment level helps reduce nutrient loads, protecting downstream water quality in this ecologically sensitive river system.