Carrillo Wastewater Treatment Plant, Zacatecas, Mexico

Carrillo is a wastewater treatment plant located in the town of Carrillo, within the municipality of Fresnillo, Zacatecas, Mexico. It serves a population of 1,095 people, making it a small-scale facility in a rural inland setting. The plant is part of Mexico's national wastewater infrastructure managed under the Ley de Aguas Nacionales. The plant provides secondary treatment, a standard level for small communities in Mexico, which typically involves biological processes to reduce organic matter and suspended solids. It has a designed capacity of 170.21 cubic meters per day and currently treats an average daily volume of 103.68 cubic meters, operating well within its capacity. Mexican regulations require compliance with NOM-001-SEMARNAT-1996 for discharge quality. The treated effluent is discharged into local watercourses that drain into the endorheic basin of northern Mexico, eventually reaching the Rio Grande de Santiago or other inland basins. This region is semi-arid, so the plant's operation is important for protecting local groundwater and surface water resources used for agriculture and livestock.

The plant discharges into local streams that are part of the endorheic drainage system of the Mexican Plateau, which does not reach the ocean. The surrounding watershed supports semi-arid ecosystems and agricultural activities. Proper treatment is critical to prevent contamination of groundwater and surface water used for irrigation and livestock, as the region faces water scarcity and relies on these resources.