St Johns WWTP - Secondary Treatment Plant in Saint Johns, Arizona

St Johns WWTP is a municipal wastewater treatment plant located in Saint Johns, Apache County, Arizona. The facility serves a population of about 3,340 people, reflecting a small community in the high desert region of the southwestern United States. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal wastewater. With a designed capacity of 2,384.80 units and a current discharge volume of 492.10 units, the plant operates well below its capacity, indicating room for future growth. The facility is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Arizona Department of Environmental Quality. The treated effluent is discharged into local waterways that ultimately drain into the Little Colorado River watershed, a tributary of the Colorado River. This region is ecologically sensitive, supporting riparian habitats and species adapted to arid conditions. The plant's operations help protect downstream water quality in this important basin.

The plant discharges into the Little Colorado River watershed, which flows into the Colorado River and eventually to the Gulf of California. This arid region supports fragile riparian ecosystems and is home to species such as the southwestern willow flycatcher. Protecting water quality is critical for maintaining habitat and recreational uses downstream.