Assessment of pollution potential of leachate from the municipal solid waste disposal site and its impact on groundwater quality, Varanasi environs, India

Open dumping of municipal solid waste is prone to groundwater contamination because of leachate production. In this paper, an attempt has been made to assess the pollution potential of leachate generated from the solid waste disposal site and its impact on aquifers in the Varanasi environs, Uttar Pradesh, India. Physico-chemical parameters of leachate and groundwater samples were determined to evaluate leachate pollution index (LPI) as well as water quality index (WQI). The leachate pollution index indicates that the leachate generated from the landfill site is moderately contaminated. The pH (7.5) of the leachate indicates that the Varanasi solid waste dumping shows mature stage of landfill site. WQI indicate that 61, 23, 9, and 4 % of the groundwater is good, poor, unsuitable for drinking purpose, and very poor water, respectively. The principal component analysis identified four major components (cumulative variance is 80.4 %), in which maximum percent of variance (36 %) was observed in the first component that suggests the natural and anthropogenic influences. Hierarchical cluster analysis depicts three types of clusters such as Ca-HCO3, Na-Mg-HCO3, and Na-HCO3 type of water in the study area. Due to the impact of leachate on the groundwater resources, it is suggested to develop an engineered landfill site to control the leachate percolation into the groundwater.