Madisonville STP - Advanced Wastewater Treatment in Madisonville, Louisiana

Madisonville STP is a municipal wastewater treatment facility located in Madisonville, St. Tammany Parish, Louisiana, United States. The plant serves a small population of 659 residents and operates as part of the local infrastructure managed by the parish. The plant provides advanced treatment, which goes beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 302.83 m³/day and a current discharge volume of 189.27 m³/day, the facility operates below its capacity. Under the U.S. Clean Water Act, such plants must comply with National Pollutant Discharge Elimination System (NPDES) permits issued by the Louisiana Department of Environmental Quality. The treated effluent is discharged into the local watershed, which drains into Lake Pontchartrain via the Tchefuncte River. Lake Pontchartrain is a large estuary connected to the Gulf of Mexico, supporting diverse aquatic life and recreational activities. The plant's advanced treatment helps protect this sensitive coastal ecosystem from nutrient pollution.

The plant's discharge enters the Tchefuncte River, which flows into Lake Pontchartrain, a major estuary in southeastern Louisiana. Lake Pontchartrain drains into the Gulf of Mexico through the Rigolets and Chef Menteur Pass. The lake supports a rich ecosystem of fish, shellfish, and migratory birds, and is a vital resource for fishing and recreation. Advanced treatment at the plant reduces nutrient loads, helping to prevent algal blooms and hypoxia in the lake and downstream coastal waters.