Marana High School WWTP: Secondary Treatment in Pima County, Arizona

Marana High School WWTP is a municipal wastewater treatment facility located in Pima County, Arizona, United States. The plant serves a population of approximately 2,400 people and operates under the regulatory framework of the US Clean Water Act, which governs wastewater discharges through the National Pollutant Discharge Elimination System (NPDES) permit program. The plant provides secondary treatment, a standard level required for most municipal facilities in the United States. Its designed capacity is 264.98 units, with an actual discharge volume of 68.14 units, indicating operational headroom. As an inland facility, it does not discharge directly to coastal waters. The treated effluent from Marana High School WWTP likely enters a local watercourse within the Santa Cruz River watershed, which flows southward into Mexico. The surrounding Sonoran Desert ecosystem relies on treated wastewater for sustaining riparian habitats and supporting local biodiversity.

The plant discharges into the Santa Cruz River basin, an intermittent river system that flows through arid southern Arizona. Treated wastewater contributes to baseflow in the river, supporting riparian vegetation and wildlife in a water-scarce region. Downstream, the river crosses into Mexico, where it eventually dissipates in the Sonoran Desert. The effluent helps maintain aquatic habitats and groundwater recharge in this ecologically sensitive area.