Mumbai topped the city-wise ranking of tap water quality, while Delhi finished at the bottom of the list, according to results of a study released by Union Cabinet Minister Ram Vilas Paswan on Saturday.
The study conducted by the Bureau of Indian Standards (BIS) said that all 11 water samples collected from various locations of Delhi failed on 19 parameters.
Out of 20 state capitals where the study was conducted, all 10 samples of tap water from Mumbai were found to comply with all 11 parameters, while other cities failed in one or more categories.
Similarly, samples drawn from 17 other state capitals were not as per the specification 'Indian Standard (IS)-10500:2012' for drinking water.
For instance, the sample in Hyderabad failed in one parameter 'phenolic compounds' and Bhubaneswar in 'Chloramines', while Chandigarh in two parameters 'Aluminium and Coliform'.
"None of the samples drawn from 13 of the state capitals -- Chandigarh, Guwahati, Bengaluru, Gandhinagar, Lucknow, Jammu, Jaipur, Dehradun, Chennai, Kolkata --complied with the requirements of the IS," he said.
In Chennai, all 10 samples failed in nine parameters like turbidity, odor, total hardness, chloride, fluoride, Ammonia, Boron and Coliform, while all nine samples in Kolkata failed in 10 quality parameters, the study showed.