Santiago Mexquititlán Wastewater Treatment Plant, Querétaro, Mexico

The Santiago Mexquititlán wastewater treatment plant is located in the community of Santiago Mexquititlán Barrio 1ro., within the municipality of Amealco de Bonfil, Querétaro, Mexico. It serves a population of approximately 6,581 residents, classifying it as a small-scale municipal facility. The plant operates under Mexico's national water regulations, which require secondary treatment for urban wastewater before discharge. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 604.80 m³/day and an actual discharge volume of 622.94 m³/day, the facility operates near its capacity. This level of treatment meets the basic requirements for protecting local water quality. The treated effluent is discharged into the local watershed, which ultimately drains into the Lerma River basin, a major hydrological system in central Mexico. The Lerma River flows into Lake Chapala, Mexico's largest freshwater lake, supporting diverse aquatic ecosystems and providing water for agriculture and human consumption. Proper treatment at this plant helps reduce nutrient and pollutant loads to these downstream water bodies.

The plant discharges into the Lerma River basin, which flows into Lake Chapala, a critical freshwater resource in central Mexico. The watershed supports irrigated agriculture and provides habitat for native fish species. Secondary treatment at this facility reduces organic pollution and helps maintain water quality in the downstream lake, which is ecologically sensitive to nutrient loading.