Otis SD Wastewater Treatment Plant, Washington County, Colorado

Otis SD is a municipal wastewater treatment plant located in Washington County, Colorado, United States. The facility serves a small population of 544 residents, reflecting its role in a rural agricultural community. The plant is situated on County Road SS, operating as part of the local infrastructure for wastewater management. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal facilities discharging to surface waters. With a designed capacity of 302.83 thousand cubic meters per year and an actual discharge volume of 227.13 thousand cubic meters, the plant operates below its capacity. The U.S. Environmental Protection Agency (EPA) and Colorado Department of Public Health and Environment regulate such facilities through National Pollutant Discharge Elimination System (NPDES) permits, ensuring compliance with water quality standards. The treated effluent from Otis SD is discharged into local waterways that ultimately drain into the South Platte River basin, a critical water source for agriculture and ecosystems in the region. The plant's operations help protect downstream water quality in the Platte River system, which flows into the Missouri River and eventually the Mississippi River. By maintaining secondary treatment, the facility reduces organic pollutants and suspended solids, supporting aquatic life in the receiving waters.

Otis SD discharges into the South Platte River basin, which flows through the High Plains region of Colorado and Nebraska. The South Platte River is a vital water source for irrigation, municipal supply, and wildlife habitat. Downstream, the river joins the Platte River, a key migratory corridor for sandhill cranes and other waterfowl. The plant's secondary treatment helps mitigate nutrient loading and protect the ecological health of these prairie river systems.