Ejido Arroyo Wastewater Treatment Plant, Tabasco, Mexico

Ejido Arroyo is a wastewater treatment plant located in the town of Arroyo, within the municipality of Nacajuca, Tabasco, Mexico. The plant serves a population of 1,825 and is part of the local municipal wastewater infrastructure, providing essential sanitation services to this small community in southeastern Mexico. The plant operates with secondary treatment, which is the standard biological treatment level required under Mexican regulations (NOM-001-SEMARNAT) for municipal wastewater. With a designed capacity of 259.20 m³/day and an actual discharge volume of 172.80 m³/day, the plant operates below its full capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into local water bodies that ultimately drain into the Grijalva River basin, one of Mexico's major hydrological systems. This region is ecologically significant, supporting diverse aquatic life and wetlands that are crucial for flood control and biodiversity in the Gulf of Mexico coastal plain.

The plant's discharge enters the local drainage network within the Grijalva River basin, which flows northward into the Gulf of Mexico. This watershed is characterized by extensive wetlands and floodplains that provide critical habitat for fish, birds, and other wildlife. The secondary treatment helps reduce organic pollutants and suspended solids, protecting downstream water quality and the ecological health of the Grijalva River delta and coastal lagoons.