El Pozo Wastewater Treatment Plant, Culiacán, Sinaloa, Mexico

El Pozo wastewater treatment plant is located in the town of El Pozo, within the municipality of Culiacán, Sinaloa, Mexico. The plant serves a small population of 1,029 residents, reflecting its role in a rural or peri-urban setting. Its designed capacity is 181.44 cubic meters per day, with an actual discharge volume of 138.24 cubic meters per day. The plant provides secondary treatment, which is the standard biological treatment required under Mexican regulations (NOM-001-SEMARNAT-1996) for municipal wastewater. This level of treatment typically involves biological processes to reduce organic matter and suspended solids before discharge. For small communities like this, secondary treatment is appropriate and aligns with national water quality standards. The treated effluent is discharged into the local watershed, which ultimately drains into the Pacific Ocean via the Culiacán River system. The plant's operation helps protect downstream water bodies from untreated sewage, supporting aquatic life and reducing health risks for communities that rely on these water resources. Its inland location, more than 50 km from the coast, reduces direct marine impact.

The plant discharges into the Culiacán River basin, which flows through the state of Sinaloa and empties into the Pacific Ocean near the city of Culiacán. This watershed supports diverse aquatic habitats and is important for local agriculture and fisheries. The secondary treatment provided by the plant helps reduce organic pollution and nutrient loading, protecting downstream ecosystems from eutrophication and maintaining water quality for human use.