Mesa Grande Wastewater Treatment Plant, Aguascalientes, Mexico

Mesa Grande is a wastewater treatment plant located in the community of Mesa Grande, within the municipality of Calvillo, Aguascalientes, Mexico. The plant serves a population of 1,917 and operates with secondary treatment, which is the standard level for small communities under Mexican water quality regulations (NOM-001-SEMARNAT). The plant has a designed capacity of 224.64 cubic meters per day and currently discharges 181.44 cubic meters per day, indicating it operates below its full capacity. As a secondary treatment facility, it removes organic matter and suspended solids, meeting typical discharge standards for inland waters. The treated effluent is discharged into local watercourses that eventually drain into the Rio Grande de Santiago basin, which flows westward to the Pacific Ocean. The plant plays a key role in protecting local streams and groundwater from untreated wastewater, supporting both community health and downstream ecosystems.

The plant discharges into the Rio Grande de Santiago watershed, which drains into the Pacific Ocean via the Santiago River. This region is part of the Central Mexican Plateau, characterized by semi-arid climate and seasonal rainfall. The receiving waters support agricultural irrigation and local biodiversity, including fish and migratory birds. Proper wastewater treatment is essential to prevent nutrient pollution and protect downstream water quality.