San Isidro Wastewater Treatment Plant, Angostura, Sinaloa

San Isidro is a wastewater treatment plant located in Angostura, Sinaloa, Mexico. It serves a population of 1,825 and operates with secondary treatment, which is appropriate for small communities in Mexico. The plant has a designed capacity of 190.08 m³/day and currently discharges 172.80 m³/day, indicating it is operating near its design capacity. As a small-scale facility, it falls under Mexico's national water regulations (Ley de Aguas Nacionales) and is subject to standards for wastewater discharge. The treated effluent is likely discharged into local water bodies that drain into the Pacific Ocean via the Sinaloa River system. The region's agricultural activities and proximity to the Gulf of California make proper wastewater treatment important for protecting downstream ecosystems and coastal water quality.

The plant is located in the Sinaloa River basin, which drains into the Gulf of California (Sea of Cortez), a biologically rich marine environment. The region supports important fisheries and migratory bird habitats. Effective secondary treatment helps reduce nutrient loading and organic pollution that could otherwise impact coastal ecosystems and local water resources used for agriculture.