El Refugio Wastewater Treatment Plant, Tepezalá, Aguascalientes, Mexico

El Refugio is a wastewater treatment plant located in Tepezalá, Aguascalientes, Mexico. It serves a small population of 730 people, typical of a rural community in the central highlands of Mexico. The plant provides secondary treatment, which is the standard level for municipal wastewater in Mexico under NOM-001-SEMARNAT-1996, ensuring removal of organic matter and suspended solids. The plant has a designed capacity of 112.32 m³/day and currently discharges 69.12 m³/day, indicating it operates below its full capacity. As a secondary treatment facility, it meets the regulatory requirements for discharge into inland water bodies. The plant is not located near the coast, reducing marine impact risks. The treated effluent likely discharges into a local arroyo or stream that feeds into the Rio San Pedro, part of the Lerma-Santiago basin, which ultimately drains into the Pacific Ocean via the Rio Grande de Santiago. The surrounding region is semi-arid, and the plant plays a key role in protecting local water quality and supporting agricultural reuse or downstream ecosystems.

The plant discharges into the Lerma-Santiago basin, which flows through central Mexico to the Pacific Ocean. The receiving water body is likely an intermittent stream in the semi-arid Aguascalientes region, supporting local agriculture and wildlife. Downstream, the Rio San Pedro and Rio Grande de Santiago provide habitat for diverse aquatic species, including endemic fish. The plant's secondary treatment helps reduce nutrient and organic pollution, safeguarding water quality for downstream communities and ecosystems.