Application of Principal Component Analysis and Correlation for Assessing Groundwater Contamination in and around Municipal Solid Waste Landfill of Ghazipur, Delhi

The present study has been executed to assess the groundwater quality and to investigate the possible sources of contamination in the adjoining areas of Ghazipur landfill site, Delhi. The groundwater samples were collected during pre and post monsoon seasons and various physico-chemical and heavy metals concentration were also analyzed. The results show that the samples which were taken adjacent to landfill site had a higher concentration of total dissolved solids (2383 mg/l), chloride (991mg/l), total hardness (659 mg/l), ammonical nitrogen (2.3mg/l), sodium (350 mg/l), calcium (534 mg/l) and sulphate (631 mg/l). Most of the heavy metals concentration in groundwater samples was found within the prescribed limit except Cu and Pb. The principal component analysis (PCA) extracted 3 factors which collectively explained 80.1% of the variation in data during post-monsoon whereas 75.4% of the variation in pre-monsoon season. The obtained results clearly show that K+, Mg2+, Na+, SO42−, and NO3− ions significantly contribute towards the high temporal pollution load to groundwater quality. Factor analysis also suggested that the continuous percolation of these contaminants from the nearby landfill could be the possible sources of contamination into groundwater aquifer system. The concentration of heavy metals in leachate have followed the order as- Fe>Zn>Cu>Pb>Ni>Cr>Cd. The overall result indicates that the landfill leachate is significantly affecting the nearby groundwater quality through continuous leaching over a long period of time. As the groundwater is used by some local residents for domestic purposes, immediate action and alternative effort should be made to supply clean water.