Evaluation Of Drinking Water Quality of Filtration Plants and Related Health Risk in Urban Communities of Lahore, Pakistan

Abstract

The present study investigated the drinking water quality evaluation of WASA installed filtration plants in Lahore. Water quality assessment is based on the 15 most important water parameters by physio-chemical analysis of untreated and treated water from concerning sites of filtration plants in comparison with a permissible range of WHO and Pak-EPA. Almost 75 water sampling sites including 42 sites with both treated and untreated water were analyzed to reveal the water chemistry of each water type. The results revealed the alkaline pH from all sites providing evidence of bicarbonates (HCO3-) major anions availability in water. The major cationic trend followed in both types of water samples based on a mean and individual basis is Na+>Ca2+>Mg2+>K+. Hydrogeochemical facies by Piper diagram revealed the major water type in both types of water samples (Na-HCO3and Na-Cl) is the same with little variation (Ca-Mg-Cl) by cationic exchange phenomenon may occur. Mean-based Water Quality Index (WQI) of treated and untreated water provides the estimation of better water quality than percentage-based calculated for each site. Further drinking water investigation by health risk assessment (HRI) proved arsenic health risk to both age groups drinking the filtration plant water. While fluorides in most sites range within a permissible range. The socio-economic evaluation of plants through detail official survey results makes us clear of some important drawbacks of filtration plants regarding monitoring, consumption, related health of the population. There is a need for much more active arsenic removal methods, investigating and regulating individual programs to assuring better water quality from filtration plants