Alacua County Southwest Landfill
On June 15th, the Bioenergy interns took a tour of the Alachua County’s southwest Landfill. Ron Bishop of Alachua County Public Works and Scott Kerwin, a University of Florida mechanical engineer, guided the 2010 interns around the 28 acre land fill that has pioneered many different solutions for mitigating landfill pollution.
The South West Landfill was opened in 1973 and later capped in 1998. At that time, it was one of the first landfills in the state that used capping as a way to reduce the emission and maximize the capture of landfill gas. Capping involves using a special liner that captures the methane produced by the decomposition of the landfill contents. The liner is also covered by topsoil, which was actually brought to the South West site from Wood Resource Recovery. Once the landfill was capped, they re-circulated leachate and ground water to maximize the production of biogas which was used to produce energy in a collaborative project with GRU. They had three gas fed generators; each one capable of producing 920 KW.
Scott also explained an ongoing project involving UF engineering students in which reverse osmosis (RO) is used to clean the landfill leachate. By adding an additional membrane to the RO system, they were able to clean the leachate to near drinking water standards. RO filters have to be replaced periodically and are very costly making this process expensive as well as energy intensive.
As a result of the need to clean landfill leachate, the Bioenergy Lab’s algae team, are currently researching the use of phycoremediation. This process involves using the nutrient rich leachate to grow algae, which not only uses up the nutrients but also removes some of the pollutants. Lindsey, Kaitlyn, and Grier described the details of their project, which includes growing both macro and micro algae in various dilutions of landfill leachate.
Ron and Scott were able to paint a very detailed picture as to the life of the landfill and the various steps that were taken to develop best practices which are now used at many sites around the state. One final point of interest; the landfill was open during a time in Florida’s history when recycling programs were just beginning to develop and gain popularity. He believes that the success of recycling extended the life of the landfill by three years.