San Pedro Lagunillas Wastewater Treatment Plant, Nayarit, Mexico

San Pedro Lagunillas wastewater treatment plant is located in the town of San Pedro Lagunillas, Nayarit, Mexico. It serves a population of 4,453, classifying it as a small-scale municipal facility. The plant is situated inland, more than 10 km from the coast, and discharges treated effluent into local water bodies. The plant provides secondary treatment, which is the standard level required under Mexican regulations (NOM-001-SEMARNAT-1996) for municipal wastewater. Its designed capacity is 950.40 m³/day, with a reported discharge volume of 864.00 m³/day, indicating operational utilization. The facility is part of the national wastewater infrastructure managed by local water authorities. The treated effluent likely drains into the Río Grande de Santiago basin, which flows westward into the Pacific Ocean. This watershed supports agricultural activities and diverse aquatic ecosystems. Proper treatment helps protect downstream water quality and public health in the region.

The plant's treated effluent enters the local drainage network, which is part of the Río Grande de Santiago basin. This river system flows through Nayarit and eventually discharges into the Pacific Ocean near San Blas. The downstream environment includes coastal lagoons and mangrove ecosystems that support migratory birds and marine life. Secondary treatment reduces organic load and pathogens, mitigating impacts on these sensitive habitats.