Valtierrilla Wastewater Treatment Plant, Guanajuato, Mexico

Valtierrilla wastewater treatment plant is located in the town of Valtierrilla, within the municipality of Salamanca, Guanajuato, Mexico. The facility serves a population of approximately 22,452 residents, classifying it as a medium-sized municipal treatment plant in the region. As a Mexican wastewater facility, Valtierrilla operates under the framework of the Ley de Aguas Nacionales (National Water Law) and NOM-001-SEMARNAT-2021, which sets discharge limits for pollutants into national waters. Plants serving communities of this size are typically required to provide at least secondary treatment to meet effluent quality standards for organic matter and suspended solids. The plant's treated effluent is discharged into the local watershed, which ultimately drains into the Lerma River basin. The Lerma River flows westward through Guanajuato and into Lake Chapala, Mexico's largest freshwater lake, before continuing to the Pacific Ocean. This basin supports diverse aquatic ecosystems and provides water for agriculture and urban use downstream.

The Valtierrilla plant discharges into the Lerma River basin, a major hydrological system in central Mexico. The Lerma River flows into Lake Chapala, which is ecologically significant as a critical habitat for migratory birds and endemic fish species. Downstream, the river continues to the Pacific Ocean, making proper wastewater treatment essential for protecting both freshwater and coastal ecosystems in the region.