Dauphin Island WWTP - Coastal Wastewater Treatment in Alabama

Dauphin Island WWTP is a municipal wastewater treatment facility located on Dauphin Island, a barrier island in Mobile County, Alabama, United States. The plant serves a population of approximately 4,678 residents, providing essential wastewater treatment for this coastal community. As a small-scale facility, it plays a critical role in protecting the sensitive marine environment surrounding the island. The plant operates under the U.S. Clean Water Act, which requires secondary treatment for municipal wastewater discharges. The National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Alabama Department of Environmental Management, governs the plant's discharge limits to ensure compliance with water quality standards. The designed capacity of 1.00 million gallons per day suggests the facility is sized to handle peak flows from the seasonal tourist population. The plant's treated effluent is discharged into the waters surrounding Dauphin Island, which ultimately flow into the Gulf of Mexico. This coastal discharge location necessitates stringent treatment to protect the ecologically sensitive barrier island environment, including seagrass beds, oyster reefs, and critical bird nesting habitats. The facility's operations are vital for maintaining water quality in the Mississippi Sound and the broader Gulf ecosystem.

Dauphin Island WWTP discharges into the coastal waters of the Mississippi Sound, which connects to the Gulf of Mexico. The island's position along the Gulf Coast makes it a critical habitat for migratory birds, sea turtles, and marine species. The surrounding waters support oyster reefs and seagrass beds that are sensitive to nutrient pollution, requiring effective wastewater treatment to prevent algal blooms and hypoxia.