Villas de San Juan Wastewater Treatment Plant, León, Guanajuato

Villas de San Juan is a wastewater treatment plant located in León, the largest city in Guanajuato, Mexico. The facility serves a population of approximately 27,008 residents, placing it in the medium-agglomeration category for Mexican wastewater infrastructure. The plant is situated in the Zona Centro district, an urban area with mixed residential and commercial activity. As a Mexican wastewater facility, Villas de San Juan operates under the framework of the National Water Law (Ley de Aguas Nacionales) and NOM-001-SEMARNAT-1996, which sets maximum permissible limits for pollutants in treated wastewater discharged into national waters. The plant's treated effluent ultimately drains into the Lerma River basin, which flows through central Mexico and into Lake Chapala, the country's largest freshwater lake. This watershed supports diverse aquatic ecosystems and provides water for agricultural and municipal use downstream. The plant plays a key role in protecting water quality in the Lerma-Chapala basin, a region facing pressures from urbanization and industrial activity.

The Villas de San Juan plant discharges into the Lerma River basin, which flows into Lake Chapala, Mexico's largest freshwater lake. This watershed is ecologically significant, supporting a variety of fish species and migratory birds. The lake is a critical water source for the Guadalajara metropolitan area and surrounding agriculture. Protecting water quality in this basin is essential to prevent eutrophication and maintain biodiversity in the lake ecosystem.