Facility: Active Landfill
Location: Freeport, The Bahamas
Owner/Operator: Sanitation Services
System: Constructed Wetland Treatment System
Installation Completion Year: 2020
Design: Three-Stage Aeration Wetland with a Waste Tire Berm
A constructed wetland treatment system was constructed at the landfill to treat up to 15,000 gallons per day of leachate. The liquid is pumped to an aerated pond, followed by an aerated nitrification wetland, then to a tertiary polishing wetland. The process flow was designed to effectively remove ammonia, organics, and suspended solids from the leachate.
To ensure long-term operation and protection against extreme weather events, key innovative design techniques were applied. The wetland was constructed using a unique berm structure to an elevation higher than the normal hurricane flood level for the area. Specifically, the berm consists of approximately 400,000 waste tires and aggregate mixed together under a secured liner system. The use of waste tires as berm material for a wetland is an unprecedented way to reuse the tires that would have otherwise been shredded and disposed in the landfill or end up in the ocean during flood events. The wetland was also designed with breakwater structures and surge inlets. These berm design considerations proved successful by remaining intact as Hurricane Dorian caused massive destruction to the islands in September 2019.
The hurricane caused some equipment and vegetation damage, so repairs and replanting are underway and start-up testing has resumed. Early results show that the system is operating as designed.
Installation of the aeration wetland tubing
Testing aeration during start-up of the system