Assessment of gases emission from the operation of the semi-aerobic landfill site by solid waste of Kathmandu Valley, Nepal

Many landfill sites around the world have been poorly engineered and operated and hence face vociferous public opposition and criticism for their adverse environmental impacts. Because of the concerns arising from poor operation and management, siting and operation of landfill sites are very sensitive public issues in Nepal. The aim of this study was to assess the environmental impacts due to the foul odour during the operation of the the Sisdol landfill in Okharpauwa VDC, Nuwakot, Nepal. The study focused on identifying the composition of gases from the Kathmandu Valley's solid waste and impacts on local areas air flow moments from the land fill site. LandGEM Ver.3.02 Model was used for the emission calculation of the landfill gases. Furthermore, the gastec and specified ditector tubes were used for the measurement of H2S gas at the study area. Among nine sites, the H2S gas concentration at site (Vent pipe of landfill site) was 1.4 ppm (recorded maximum). The gas was found to be diluted at 208m downwind location and reached the value near to clean air, i.e., 0.2 ppb. The observed gas concentration was lower than the toxic range though the concentration level was found to have characteristic odour. The significant level of adverse impact was found nearby the landfill site. People working surrounding area of the landfill site were more vulnerable to different impacts