HOLCOMB WWTP - Secondary Treatment Plant in Dunklin County, Missouri

HOLCOMB WWTP is a municipal wastewater treatment facility located on County Road 330 in Dunklin County, Missouri, United States. The plant serves a small population of 740 residents, reflecting its role in a rural community within the Mississippi River watershed. The plant provides secondary treatment, a standard level required by the U.S. Clean Water Act for municipal wastewater. With a designed capacity of 454.25 million gallons per year and an actual discharge volume of 314.19 million gallons per year, the facility operates below its capacity. Under the National Pollutant Discharge Elimination System (NPDES), plants of this scale must meet effluent limits to protect water quality. The treated effluent is discharged into a local water body that ultimately drains into the Mississippi River, a major river system flowing into the Gulf of Mexico. The plant's operations contribute to protecting downstream aquatic ecosystems and maintaining water quality in the region.

The plant discharges into a tributary of the Mississippi River, which flows through the central United States and empties into the Gulf of Mexico. The Mississippi River supports diverse aquatic life and is a critical migratory corridor for fish and birds. The plant's secondary treatment helps reduce nutrient and pollutant loads, mitigating impacts on downstream water quality and the Gulf's hypoxic zone.