Good tap water is something we do have in the UK.
Honestly bro, no offense, but the stuff that comes of my tap in the UK tastes so full of chemicals that drinking it does not seem like a good idea.
I can honestly say that the tap water in Sri Lanka, India and Nepal, where I lived for a few years, tasted healthier. And no, I didn't get ill drinking what the locals drank. I was actually pretty disgusted at the waste caused by the discarded 'Mineral Water' bottles discarded by others.
Were you in the south east / London? the tap water there is pretty poor, but the rest of the UK is better than most bottled water. The Isle of white water tastes so pure, i'll never forget how nice it tasted.
Never been to India, ill take your word for it, but I find that hard to believe based on the population, the demographics and level of development. I guess it depends where in India.