Natural pollution filters such as forests and wetlands have been replaced with parking lots and subdivisions. Sediment runoff from construction sites chokes the Pontchartrain Basin's rivers and bayous. Click here for full size photo. Urban storm water is the largest single pollution source in Lake Pontchartrain. With every rain, storm water carries pollution from the streets, lawns, roofs, and parking lots of the New Orleans metropolitan area into the lake through the storm-drain system.
Storm water contains oil and grease, heavy metals, sediments, and lawn chemicals.
Many communities throughout the Pontchartrain Basin have antiquated sewerage systems plagued by cracked lines and overloaded Click here for full size photo. treatment plants. These systems allow large amounts of untreated or partially treated sewage to enter the storm-drain system, introducing more pollution into the lake. In some areas, untreated sewage from fishing camps is discharged directly into Lake Pontchartrain and the surrounding waters. During the past 60 years, almost 67,000 acres of wetlands have been lost in the Pontchartrain Basin. Wetlands, which serve as natural pollution filters, have been channeled, drained, dredged, and filled, resulting in severe impacts to the basin's ecosystem.