Assessment of groundwater quality using WQI and GIS near the Karsara municipal landfill site, Varanasi, India

Abstract

The present paper reports the evaluation of the groundwater quality around the municipal landfill site in Varanasi City, Uttar Pradesh, India. Leachate pollution index (LPI) and water quality index (WQI) have been used to determine the quality of leachate of landfill and groundwater in the study area. LPI value (16.81) of landfill leachate revealed the presence of significant amount of the pollutants. WQI of groundwater samples near the landfill site has been calculated and water quality map has been prepared by using WQI in GIS environment for both pre- and post-monsoon periods of the year 2016. Results of WQI revealed that 35% groundwater samples are good, 35% marginal, 20% excellent, and 10% are in fair category in pre-monsoon period while in post-monsoon 70% samples are marginal, 15% excellent, 10% fair, and 5% are in good category. WQI map shows that most of the study area near the landfill site is in fair category during pre-monsoon season but in threatened category during post-monsoon season. The results of the physicochemical analysis of groundwater have shown that the water is not safe for drinking purpose as some parameters like TDS, hardness, total alkalinity, and nitrate and iron content were observed to be above the acceptable limit (WHO and BIS) of drinking water quality. This study revealed that WQI and LPI can also be an important monitoring tool for landfill policy makers and the public to safeguard groundwater pollution risk from the landfill.