Ocotlán Wastewater Treatment Plant, Jalisco, Mexico

The Ocotlán wastewater treatment plant is located in Ocotlán, Jalisco, Mexico, within the Región Ciénega. It serves a population of approximately 164,834, classifying it as a large agglomeration under Mexican water management standards. The plant is situated near the eastern shore of Lake Chapala, Mexico's largest freshwater lake, and its operations are critical for protecting this vital water resource. As a large-scale facility in Mexico, the plant is subject to federal water quality regulations under the Ley de Aguas Nacionales and Normas Oficiales Mexicanas (NOMs), which set discharge standards for municipal wastewater. Plants of this scale typically employ secondary or advanced treatment to meet regulatory requirements. The designed capacity is reported as 1.00 (likely in cubic meters per second or similar unit), indicating a substantial infrastructure investment. The plant's discharge ultimately reaches Lake Chapala, which drains into the Río Grande de Santiago and eventually flows to the Pacific Ocean. Lake Chapala is an ecologically sensitive water body that supports diverse aquatic life and provides water for irrigation and drinking. The plant plays a key role in preventing nutrient and pathogen pollution in this important lake and downstream river system.

The plant discharges into the Lake Chapala watershed, which is part of the Río Grande de Santiago basin. Lake Chapala is Mexico's largest freshwater lake and a critical habitat for endemic fish species and migratory birds. The lake's health is sensitive to nutrient loading from municipal and agricultural sources. Downstream, the Río Grande de Santiago flows through the states of Jalisco and Nayarit before reaching the Pacific Ocean, supporting diverse ecosystems along its course.