Gas Emission Control by Remediation of a Mountain of Inappropriate Waste Disposal

Remediation of an industrial waste dumpsite that resulted from inappropriate disposal was conducted by removing buried wastes, placing a soil cover and installing several ventilation pipes. We observed methane gas fluxes from investigations over six years before and after the remediation, and estimated the reduction of methane gas emission. The gas fluxes from the ground were observed by using a closed static chamber technique. Meanwhile, a simplified method for the measurement of methane gas fluxes from the ventilation pipes and their surrounding areas was developed using a large chamber and a laser methane detector. Because the diameters of the ventilation pipes including their surrounding areas were more than 30 cm, existing measurement methods could not be used. After the remediation, the methane emissions decreased from 25-150 L/min to 3 . 8-9 . 5 L/min, and most of those emissions were from the areas surrounding the ventilation pipes. The danger to the nearby environment and the contribution to global warming were reduced by the remediation because landslides could be avoided and methane gas emission was reduced. However, stabilization of the abandoned waste is still in progress because methane gas continues to exist inside the site after the remediation.