Calico Rock WWTP: Secondary Treatment Plant on the White River, Arkansas

Calico Rock WWTP is a municipal wastewater treatment facility located in Calico Rock, Arkansas, along the White River. The plant serves a small population of 1,545 residents and operates with a designed capacity of 946.35 million gallons per year, treating an average discharge volume of 317.98 million gallons annually. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal wastewater facilities. Under the National Pollutant Discharge Elimination System (NPDES), plants of this scale are permitted by the Arkansas Department of Energy and Environment - Division of Environmental Quality, ensuring compliance with effluent limits that protect water quality. Treated effluent from Calico Rock WWTP is discharged into the White River, which flows southeast through Arkansas and eventually joins the Mississippi River near the Arkansas-Mississippi border. The White River supports diverse aquatic life and is an important recreational and ecological resource in the region.

The plant discharges into the White River, a major tributary of the Mississippi River. The White River basin supports a variety of fish and wildlife, including several species of freshwater mussels and migratory birds. Downstream, the river flows through the Mississippi Alluvial Plain before reaching the Gulf of Mexico, making the plant's discharge important for maintaining water quality in this ecologically sensitive watershed.