McAllen Plant 3 North Wastewater Treatment Plant, McAllen, Texas

McAllen Plant 3 North is a municipal wastewater treatment facility located in McAllen, Texas, serving an estimated population of 39,380. The plant is situated in Hidalgo County, part of the Rio Grande Valley region near the U.S.-Mexico border. As a medium-sized agglomeration, it plays a key role in managing wastewater for this growing urban area. Under the U.S. Clean Water Act, municipal wastewater treatment plants of this scale are typically required to provide secondary treatment through the National Pollutant Discharge Elimination System (NPDES) permitting program. The plant's operations are regulated by the Texas Commission on Environmental Quality (TCEQ), which issues permits that set effluent limits to protect water quality. The plant's treated effluent is discharged into local waterways that ultimately drain into the Rio Grande, a major river that forms the border between the U.S. and Mexico. The Rio Grande flows into the Gulf of Mexico, supporting diverse aquatic ecosystems and providing water for agriculture and communities. Proper treatment at this facility helps protect downstream water quality and ecological health.

The plant discharges into the Rio Grande basin, which flows southeast to the Gulf of Mexico. This watershed supports critical habitats for fish, birds, and other wildlife, including migratory species along the Central Flyway. The region's semi-arid climate makes water quality management essential for maintaining ecosystem health and meeting downstream water needs.