Ejido Santa Rosa Wastewater Treatment Plant, Tacotalpa, Tabasco, Mexico

Ejido Santa Rosa is a municipal wastewater treatment plant located in Tacotalpa, within the state of Tabasco, Mexico. The facility serves a population of approximately 2,191 residents, classifying it as a small-scale treatment system in a rural or peri-urban setting. Its location in the tropical lowlands of southeastern Mexico places it within a region characterized by high rainfall and extensive river networks. The plant provides secondary treatment, which is the standard biological process for removing organic matter and suspended solids. With a designed capacity of 259.20 m³/day and an actual discharge volume of 207.36 m³/day, the facility operates below its design capacity, indicating adequate hydraulic capacity for current loads. Under Mexican regulations (NOM-001-SEMARNAT-1996 and subsequent updates), secondary treatment is required for discharges into water bodies, and the plant's performance aligns with these national standards. The treated effluent is discharged into local waterways that ultimately drain into the Grijalva River basin, one of Mexico's major hydrological systems. The Grijalva River flows northward through Tabasco and empties into the Gulf of Mexico, supporting diverse aquatic ecosystems and providing water for agriculture and communities downstream. The plant's operation helps protect these water resources from untreated sewage pollution.

The plant discharges into the Grijalva River basin, which drains into the Gulf of Mexico. The Grijalva River is a critical waterway in southeastern Mexico, supporting wetlands, mangroves, and estuarine habitats near its mouth. The region's high rainfall and flat terrain make it susceptible to flooding, and the plant's secondary treatment reduces organic load and pathogens, mitigating impacts on downstream aquatic life and human uses such as fishing and recreation.