MITIGATION OF METHANE EMISSIONS AT LANDFILL SITES IN NEW-ENGLAND, USA

Field measurements of methane emissions from landfills are essential i f one is to accurately constrain uncertainties in current estimates of global methane emissions from landfills and document emissions reduct ions realized by currently available control technology. Two experimen tal techniques for the measurement of methane flux from landfills, flu x chamber measurements and tracer flux techniques, have been evaluated at a 24 hectare landfill site in New England. Agreement between the t wo techniques was quite good, with the flux chamber technique giving a landfill wide methane flux of 16.4 m(3) CH4 min(-1) while a series of seven tracer flux tests resulted in a mean flux of 17.8 m(3) CH4 min( -1). Model estimates suggest that the installation of gas recovery mea sures at the five largest landfill sites in the state of New Hampshire and the ten largest sites in Massachusetts would reduce landfill emis sions in each state by approximately 75%, resulting in a total emissio ns reduction of 65 x 10(9) g CH4/yr.