Las Meladas Wastewater Treatment Plant, Durango, Mexico

Las Meladas is a wastewater treatment plant located in the small community of Las Meladas, within the municipality of San Dimas, Durango, Mexico. The plant serves a population of 73, reflecting its role in a rural setting. As a secondary treatment facility, it provides biological treatment to reduce organic pollutants and suspended solids before discharge. The plant operates under Mexico's national water regulatory framework, which includes the Federal Water Rights Law and standards such as NOM-001-SEMARNAT-1996 for wastewater discharge. For small communities like Las Meladas, secondary treatment is typical to meet environmental quality objectives. The plant has a designed capacity of 8.64 volume units and currently treats 6.91 volume units, indicating it operates below capacity. The treated effluent is discharged into a local watercourse that ultimately drains into the Pacific Ocean via the Presidio River basin. This region in Durango features mountainous terrain and seasonal rainfall, making water quality management important for downstream ecosystems and agricultural uses. The plant's operation helps protect local streams and the broader watershed from untreated sewage impacts.

The plant discharges into a tributary of the Presidio River, which flows westward through Durango and Sinaloa before emptying into the Pacific Ocean near Mazatlan. The watershed supports diverse aquatic life and is used for irrigation and livestock watering. Downstream ecosystems include riparian habitats and coastal lagoons that rely on adequate water quality. The plant's secondary treatment reduces organic load and pathogens, mitigating eutrophication risks in the river and coastal zone.