San Pedro Atocpan Wastewater Treatment Plant, San Pablo Oztotepec, Ciudad de México

San Pedro Atocpan is a wastewater treatment plant located in the Pueblo San Pedro Atocpan area of San Pablo Oztotepec, within the Milpa Alta borough of Ciudad de México, Mexico. The plant serves a population of approximately 17,351 people, classifying it as a medium-sized agglomeration under Mexican wastewater regulations. In Mexico, wastewater treatment plants of this scale are typically regulated under the National Water Law (Ley de Aguas Nacionales) and must comply with official Mexican standards (NOM-001-SEMARNAT-1996) for discharge quality. These standards set limits on pollutants based on the receiving water body type. The plant discharges treated wastewater into the local watershed, which ultimately drains into the Valley of Mexico basin. This region is hydrologically closed, meaning water does not naturally flow to the sea; instead, it is managed through a complex system of canals, tunnels, and drainage works. The treated effluent contributes to the local water cycle and supports agricultural and ecological uses in the area.

The plant is located in the Valley of Mexico, an endorheic basin with no natural outlet to the sea. Treated wastewater from the plant likely flows into local streams or canals that are part of the region's artificial drainage system, eventually reaching the Tula River or the Mezquital Valley via the Central Drainage System. This water supports irrigation in the Mezquital Valley, one of Mexico's largest agricultural areas, but also carries implications for water quality and soil health. The surrounding ecosystem includes remnants of the original lacustrine environment, which is ecologically sensitive and supports diverse aquatic life.