Spreading of leachates to soil, surface and groundwater aquifers is a prevailing problem with unlined landfills, causing many problems with adverse impacts on the surrounding environment. The impact of leachate contamination on groundwater quality was investigated from unlined ex-landfill site at Taman Beringin in Malaysia to identify the characteristics of the groundwater, and the possible impacts on the environment. Various physico-chemical parameters including: temperature, pH, color, TDS, TSS, BOD, COD, S2−, F−, Cl−, NH3-N, SO42-\documentclass[12pt]{minimal}
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\begin{document}$${\text{NO}}_{3}^{ - }$$\end{document}, and heavy metals: Ag, As, Cd, Cu, Cr3+, Cr6+, Fe, Hg, Ni, Pb, Zn, Mn, B, Se, Sn and Ba, were collected from four (4) monitoring wells and six (6) surface raw leachate points between December 2012 and January 2013. Physico-chemical analyses of sampled leachates and groundwater followed standard analytical methods. The results showed considerable impact of leachates on groundwater with high concentration of most chemical parameters in groundwater samples: COD (101.75 ± 99.42), BOD (28 ± 30.99), NH3-N (31.10 ± 19.12), F− (0.72 ± 0.32) and heavy metal; Pb (0.042 ± 0.045), Ni (0.016 ± 0.006), Fe (0.41 ± 0.68) have exceeded the Malaysian National Drinking Water Quality Standard and National Water Quality Standards CLASS II A. Remedial measures are suggested to prevent further spreading of leachates into rivers via groundwater flow. In addition, combined process of routine chemical treatment prior to biological treatment is necessary to improve the existing leachate quality to minimize the effects on the surrounding environment.
