Mesa Greenfield WRP - Gilbert, Arizona Wastewater Treatment Plant

Mesa Greenfield WRP is a wastewater treatment facility located in Gilbert, Arizona, within the Phoenix metropolitan area. The plant serves a population of around 143,640, classifying it as a large agglomeration under U. S. regulatory frameworks. As a U. S. facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Arizona Department of Environmental Quality. For plants serving over 100,000 people, secondary treatment is standard, with potential requirements for nutrient removal to protect downstream water quality. The treated effluent from Mesa Greenfield WRP likely discharges into the Gila River watershed, which flows into the Colorado River and ultimately the Gulf of California. The facility plays a key role in protecting local water resources in the arid Southwest, where water reuse and conservation are critical.

The plant's discharge enters the Gila River basin, a tributary of the Colorado River. This watershed supports diverse aquatic life and is a vital water source for agriculture and communities in the arid Southwest. Downstream, the Colorado River delta in the Gulf of California is an ecologically sensitive area important for migratory birds and estuarine species.