El Largo Wastewater Treatment Plant, Chihuahua, Mexico

El Largo wastewater treatment plant is located in the town of El Largo, within the municipality of Madera, in the state of Chihuahua, Mexico. The facility serves a population of approximately 4,466 people, making it a small-scale municipal treatment plant in a rural mountainous region of northern Mexico. The plant provides secondary treatment, which is the standard biological treatment process that removes organic matter and suspended solids. With a designed capacity of 777.60 cubic meters per day and an average daily discharge of 691.20 cubic meters, the plant operates at about 89% of its design capacity. As a Mexican facility, it operates under the national water quality regulations (NOM-001-SEMARNAT-1996 and subsequent updates), which set discharge limits for pollutants into national waters. The treated effluent is discharged into local watercourses that eventually drain into the Rio Grande/Rio Bravo basin, which flows to the Gulf of Mexico. The plant plays a crucial role in protecting downstream water quality in the arid Chihuahuan Desert ecosystem, where water resources are scarce and sensitive to pollution.

The plant discharges into the Rio Grande/Rio Bravo watershed, which flows through the Chihuahuan Desert and ultimately reaches the Gulf of Mexico. This region is ecologically sensitive due to its arid climate and limited water resources. The treated effluent supports base flows in local streams, which are vital for riparian habitats and migratory bird species along the Central Flyway.