Cetys Wastewater Treatment Plant, Mexicali, Baja California, Mexico

Cetys is a wastewater treatment plant located in Mexicali, Baja California, Mexico. It serves a small population of approximately 3,100 people, providing secondary treatment for municipal wastewater. The plant operates within the urban infrastructure of Mexicali, a city in the arid Colorado River region near the U.S.-Mexico border. The plant employs secondary treatment, which is the standard biological process for removing organic matter and suspended solids. With a designed capacity of 604.80 volume units and an average discharge of 293.76, the plant operates below its maximum capacity. Under Mexican regulations (NOM-001-SEMARNAT-1996), secondary treatment is required for discharges into water bodies, ensuring compliance with national water quality standards. The treated effluent is discharged into the local drainage system, which ultimately flows into the Colorado River basin. The Colorado River is a critical water source for the arid southwestern United States and northwestern Mexico, supporting agriculture, urban water supply, and ecosystems in the Colorado River Delta. The plant's operation helps protect downstream water quality in this sensitive desert environment.

The plant discharges into the Colorado River basin, which flows through the arid Mexicali Valley and eventually reaches the Gulf of California (Sea of Cortez). This region supports important wetland and estuarine habitats, including the Colorado River Delta, which is a critical stopover for migratory birds and supports diverse aquatic life. Secondary treatment helps reduce nutrient and organic pollution, mitigating impacts on downstream ecosystems.