Fukuoka City Environmental Agency and Fukuoka University announced on July 26, 2011, that their jointly developed landfill technology to "improve current landfill sites with 'semi-aerobic landfill structure (Fukuoka method)'" was accredited as a new method for Clean Development Mechanism (CDM), as defined in the United Nations Framework Convention on Climate Change (UNFCCC). This new landfill technology is the world's first accredited method to control methane emissions at landfill sites.
"Semi-aerobic landfill structure (Fukuoka method)" refers to a mechanism whereby leachate (waste water) is quickly removed from waste materials, allowing the inflow of air by installing perforated collection pipes and vertical perforated gas venting pipes at the bottom of the landfill. As the outlet of the perforated collection pipe is always open to air, by using internal fermentation heat, air flows naturally, without the need for an external energy source.
By maintaining aerobic conditions in the waste bed interior, the Fukuoka Method accelerates the decomposition of waste materials, improves leachate water quality and inhibits the emission of methane gas. At present, because most of the world's landfill sites, including those of developing countries, are anaerobic landfills, the Fukuoka Method will enable substantial reductions in greenhouse gas emissions.