Assessment of groundwater quality of Cossipore and Garia using WA-WQI and CCME-WQI methods

Abstract

ABSTRACT Water Quality Index (WQI) is a standard tool that is internationally accepted for assessing water quality. This WQI reduces a large number of water quality indicators into helpful for the selection of appropriate treatment techniques to meet the concerned issues. In the present study, an attempt has been made to assess the WQI of groundwater at Garia and Cossipore areas situated in the south and north Kolkata of West Bengal in India. In these two areas, there are two groundwater sampling points which are being monitored by the West Bengal Pollution Control Board (WBPCB). The WBPCB usually collect groundwater samples from the above two stations in the months of April and October each year i.e., two times a year. For the present study, eleven years, from the year 2011 to 2021, of groundwater quality data were collected from the WBPCB website. In this study, only physical and chemical parameters have been considered to determine the quality of ground water according to the data available from WBPCB. No radioactive substances have been considered. For these two locations, groundwater was assessed using WQI under the influence of several physical and chemical parameters by using the Weighted Arithmetic Water Quality Index (WA-WQI) and the Canadian Council of Ministers of Environment Water Quality Index (CCME-WQI) methods. The evaluation was done for seven physico-chemical parameters i.e. pH, turbidity, magnesium, total alkalinity chloride, calcium, and total hardness for the eleven consecutive years from 2011 to 2021 and by comparing their values with the standards set by the Bureau of Indian Standards. The obtained CCME-WQI values for Garia (out of 15 values,4 are found fair,11are found marginal) and for Cassipore (out of 14 values, one is found fair, two are found marginal,11 are found poor) and three remaining values indicate the “poor” and not suitable for drinking without treatment. The WA-WQI values for Garia (out of 15 values,2 are found good, 5 are poor,3 are very poor and 5 are >100indicate the groundwater quality is unfit for the consumption of humans without proper treatment. WQI values for Cossipore (out of 14 values one is poor, one is very poor and the other 12 are >100) i.e. indicates the groundwater quality is unfit for humans consumption without proper treatment.