Leachate Characterization and Surface Groundwater Pollution at Municipal Solid Waste Landfill of Gohagoda, Sri Lanka

As a developing country, protecting groundwater resources is extremely essential in Sri Lanka. Landfills are one of the main sources of water pollution. The filling of the Gohagoda disposal yard, takes place at a distance about 50m from Gohagoda water intake plant. In addition, there is several boreholes located close proximity of the landfill, which used for drinking and domestic purposes. A study of composition of landfill leachate and groundwater pollution conducted at Gohagoda landfill site, which is located at north-west of Kandy city. The Leachate sampled at nine different locations of the landfill. Groundwater samples were collected using auguring at five locations. In addition, to detect the seasonal variation of the water quality in the nearby water wells, four water samples obtained during both wet and dry seasons. Leachate and groundwater were physically and chemically characterized. Parameters measured were pH, Sulphate, Nitrate, Nitrites, Heavy metals (Pb, Zn, Ni, Cr, CO, Fe, Mn, Cu). The results showed that leachate of the landfill were most likely methanogenic phase, based on the alkaline pH value recorded. These results also showed that significant number of borehole were contaminated where concentration of physio-chemical parameters are above the W.H.O standards required for drinking water. Therefore, this landfill is a threat for the environment, and government should do sanitary landfill to prevent further contamination of groundwater as well as soil.