Calculation of Water Quality Index

Water quality indices (WQI) calculated for water distribution system parameters measured from household water samples using method described in Akter (2016). Four WQI were calculated: regulated, technical, aesthetic, and microbial. Regulated WQI include parameters that were measured in household tap water that are regulated in National Primary Drinking Water Regulations. Technical and aesthetic WQI include parameters in the USEPA Secondary Drinking Water Standards, which are not enforced but have an impact on non-health aspects of drinking water quality. Microbial WQI includes indicators of microbial activity such as turbidity, ATP, chlorine, and TOC.