Assessing the risk of landfill leachate on the groundwater quality of Chandigarh

Aim: Unscientific dumping of municipal solid waste (MSW) is still prevalent in the developing world, leading to adverse environmental and human health consequences. This study was conducted to assess the groundwater contamination due to leachate from the MSW dumping site in Chandigarh. Methodology: Leachate and groundwater samples from different sources were collected for two sampling periods from the vicinity of dumping site within a radius of 3 km. Collected samples were analyzed for physico-chemical parameters, heavy metals and microbiological examination. Results: The result showed high load of organic and inorganic contaminants in leachate as it had a higher COD value (10008 mgl(-1) and 18280 mg l(-1)) whereas ammoniacal nitrogen (NH4+-N) levels were 2389 mg l(-1) and 5796 mg l(-1) for two sampling periods. The concentration of Cu and Zn were highest amongst all the analyzed heavy metals in leachate samples. Almost all parameters in groundwater samples exceeded the BIS and WHO standard limits, which showed high contamination of groundwater surrounding the dumping site. Interpretation: Higher concentrations of COD and NH4+-N in most groundwater samples indicates percolation of landfill leachate into the groundwater aquifer, leading to its contamination. Groundwater samples collected near the dumping sites of lower depth have higher levels of pollutants than the samples collected from higher depth.