Santa Ana del Valle Wastewater Treatment Plant, Oaxaca, Mexico

Santa Ana del Valle is a wastewater treatment plant located in the town of Santa Ana del Valle, Oaxaca, Mexico. It serves a population of approximately 2,738 residents, making it a small-scale municipal facility. The plant is situated in the Tlacolula Valley, a semi-arid region in the central valleys of Oaxaca. The plant provides secondary treatment, which is the standard biological treatment required under Mexican regulations (NOM-001-SEMARNAT) for municipal wastewater. With a designed capacity of 432.00 m³/day and an actual discharge volume of 259.20 m³/day, the plant operates below its full capacity. The treated effluent is discharged into local watercourses that drain into the Río Salado, a tributary of the Río Atoyac, which eventually flows into the Pacific Ocean via the Río Verde. The plant plays a crucial role in protecting the region's water resources, particularly the groundwater and surface waters used for agriculture and domestic purposes in the Tlacolula Valley.

The plant discharges into the Río Salado watershed, part of the Río Atoyac basin that drains into the Pacific Ocean. The Tlacolula Valley is an arid to semi-arid region where water resources are scarce, making the treatment and reuse of wastewater critical for sustaining local agriculture and ecosystems. The downstream environment supports diverse aquatic life and provides irrigation for crops such as maize and agave.