Sauz de Arriba Wastewater Treatment Plant, Durango, Mexico

Sauz de Arriba is a wastewater treatment plant located in the town of Sauz de Arriba, within the municipality of San Juan del Río, Durango, Mexico. The plant serves a small population of 849 residents, reflecting its role in a rural or semi-urban setting. It operates with secondary treatment, which is a standard biological process for removing organic matter and suspended solids. As a secondary treatment facility, Sauz de Arriba meets the basic requirements for wastewater treatment in Mexico, where the national water law (Ley de Aguas Nacionales) and NOM-001-SEMARNAT-1996 set discharge standards. For small communities like this, secondary treatment is typically adequate to protect local water quality. The plant's designed capacity of 235.87 m³/day indicates it is sized appropriately for the current population, with a reported discharge volume of 99.36 m³/day. The plant's treated effluent is discharged into the local watershed, which ultimately drains into the Nazas River basin, part of the larger hydrological region that flows towards the Laguna de Mayrán, an endorheic basin in northern Mexico. The surrounding environment is semi-arid, making water quality management crucial for sustaining local ecosystems and agricultural uses.

The plant discharges into the Nazas River basin, which flows into the Laguna de Mayrán, a closed basin that supports local agriculture and wildlife. The semi-arid climate means that water resources are limited, and maintaining good effluent quality is essential to prevent contamination of groundwater and surface water used for irrigation. The region's aquatic ecosystems depend on consistent water quality to sustain biodiversity.