Rio Viejo Wastewater Treatment Plant, Centro, Tabasco, Mexico

Rio Viejo is a wastewater treatment plant located in Centro, Tabasco, Mexico, serving a population of 9,127. The facility operates with primary treatment, which is the initial stage of wastewater processing involving physical separation of solids. The plant has a designed capacity of 864 cubic meters per day and discharges a similar volume of treated effluent. As a Mexican treatment plant, Rio Viejo operates under the national water quality regulations enforced by CONAGUA (Comision Nacional del Agua). For a plant serving approximately 9,000 people, primary treatment may be considered basic, though Mexican standards often require secondary or advanced treatment for larger agglomerations. The plant's capacity utilization appears to be at full capacity based on the discharge volume matching the designed capacity. The treated wastewater from Rio Viejo is discharged into local water bodies within the Grijalva-Usumacinta basin, one of Mexico's most significant hydrological systems. This basin drains into the Gulf of Mexico, supporting diverse aquatic ecosystems and providing water resources for agriculture and communities in Tabasco. The plant plays a role in protecting downstream water quality in this ecologically sensitive region.

Rio Viejo discharges into the Grijalva-Usumacinta river system, which flows through the state of Tabasco into the Gulf of Mexico. This basin is one of the largest in Mexico, supporting extensive wetlands and floodplains that provide critical habitat for fish, birds, and other wildlife. The region's tropical climate and heavy rainfall make effective wastewater treatment essential to prevent nutrient pollution and protect downstream aquatic ecosystems.