San Francisco del Mezquital Wastewater Treatment Plant, Durango, Mexico

San Francisco del Mezquital is a municipal wastewater treatment plant located in the town of San Francisco del Mezquital, within the Mezquital municipality of Durango, Mexico. The facility serves a population of 2,958 and is classified as a small-scale treatment plant under Mexican wastewater regulations. The plant employs secondary treatment, which is the standard biological process required by Mexican law (NOM-001-SEMARNAT-1996) for municipal wastewater before discharge. With a designed capacity of 604.80 volume units and an average daily flow of 432.00, the plant operates at approximately 71.4% of its capacity, indicating adequate headroom for current demand. The treated effluent is discharged into local waterways that eventually drain into the Pacific Ocean via the Mezquital River system. The plant plays a crucial role in protecting downstream aquatic ecosystems and communities from untreated sewage, particularly in this semi-arid region where water resources are limited.

The plant discharges into the Mezquital River basin, which flows through Durango and ultimately reaches the Pacific Ocean via the San Pedro Mezquital River. This watershed supports diverse aquatic life and provides water for agriculture and local communities. Secondary treatment reduces organic pollutants and pathogens, helping to maintain water quality in a region where seasonal droughts stress freshwater resources.