Las Piedras Wastewater Treatment Plant, Compostela, Nayarit

Las Piedras is a wastewater treatment plant serving the community of Compostela in the state of Nayarit, Mexico. With a population served of 274, it is a small-scale facility that provides secondary treatment to municipal wastewater. The plant has a designed capacity of 37.15 m³/day and currently discharges 25.92 m³/day of treated effluent. As a secondary treatment plant, Las Piedras meets the standard level of treatment required for municipal wastewater in Mexico under the national water quality regulations (NOM-001-SEMARNAT-1996). These regulations set discharge limits for parameters such as biochemical oxygen demand (BOD) and total suspended solids (TSS), which secondary treatment typically achieves. The plant's small scale aligns with the needs of a rural or peri-urban community. The treated effluent from Las Piedras is discharged into a local water body that eventually drains to the Pacific Ocean, given the plant's proximity to the coast (within 10 km). The Nayarit coastline is ecologically significant, supporting mangroves, estuaries, and marine biodiversity. Proper treatment at this plant helps protect coastal water quality and the health of downstream ecosystems.

The plant discharges into a local watercourse that flows toward the Pacific Ocean, passing through coastal ecosystems in Nayarit. The region's watershed supports diverse aquatic life, including fish and crustaceans, and the nearby coast features important habitats such as mangroves and estuaries. Effective wastewater treatment is crucial to prevent nutrient loading and contamination that could harm these sensitive environments.