Round Mountain WWTP - Custer County, Colorado Wastewater Treatment Plant

Round Mountain WWTP is a municipal wastewater treatment plant located in Custer County, Colorado, United States. It serves a small population of 1,056 residents, typical of rural mountain communities in the region. The plant provides secondary treatment, which is the standard level required by the US Clean Water Act for inland facilities discharging to freshwater bodies. The plant has a designed capacity of 529.96 megaliters and an actual discharge volume of 302.83 megaliters, indicating it operates below capacity. As a US facility, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Colorado Department of Public Health and Environment, which set effluent limits to protect water quality. The treated effluent is discharged into local waterways that drain into the Arkansas River basin, ultimately reaching the Mississippi River and the Gulf of Mexico. The plant plays a key role in protecting the headwaters of this major river system from nutrient and pathogen pollution.

The plant discharges into streams that feed the Arkansas River, a major tributary of the Mississippi River system. The Arkansas River flows through the Great Plains and into the Mississippi, which empties into the Gulf of Mexico. The watershed supports diverse aquatic life and is important for irrigation and recreation. The plant's secondary treatment helps reduce organic loads and nutrients, mitigating downstream eutrophication risks.