Quality of drinking water in Kathmandu valley, Nepal

Present study was undertaken to analyze drinking water quality of Kathmandu valley with the estimation of essential minerals of public health concern. Twenty water samples of each source, viz. public water supply, private water supply, and processed drinking water supply, were randomly collected. Sample analysis was carried out for physical (temperature, pH, and electrical conductivity), chemical (calcium, magnesium, sodium, and potassium), and microbiological (total coliform—TC) parameters. It was found that the physical parameters such as temperature, pH, and electrical conductivity (EC) were within the World Health Organization (WHO) drinking water quality guidelines. Generally, for all the water sources the average concentration of calcium was below the WHO drinking water quality guidelines as well as DRI (Dietary Reference Index) recommendations. Moreover, the concentration of magnesium, sodium, and potassium was also found below the DRI recommendations for all the water sources. Microbiological parameter enumerated for TC in processed drinking water depicted bacterial population from 0 CFU/100 mL to 46 CFU/100 mL. The presence of TC in processed drinking water makes the water unacceptable for drinking purpose, although the physical parameters were almost within the WHO drinking water quality guidelines. The presence of required amount of minerals plays a critical role in maintaining human health system and vitality. Therefore, this study explores the quality of drinking water in the Kathmandu valley in terms of minerals and TC bacteria.