Quantitative assessment of underground drinking water pollution of water of India Mark II (IM2) hand pumps at Moradabad for seven different sites, which are also deprived of other source of drinking water, has been carried out on the basis of calculated values of water quality indices (WQI). Water quality index for all the sites has been calculated with the help of estimated values of thirteen different physio-chemical parameters and drinking water standards prescribed by W.H.O. Underground drinking water was found to be severely polluted invariably at all the sites of study. People dependent on the water of source of study are prone to health hazards of polluted drinking water and water quality management is needed in the catchment area of study. Estimated higher values of different water quality parameters also verify the extent of drinking water pollution. Hence, assessment of water quality on the basis of calculated values of WQI is once again proved to be an effective tool.