Yeah, about that, the UN DID declare clean safe water as a human right, ofcourse the US did not sign it and does not want it as an enforceable federal law for... reasons:

The right to water.

One of the most important recent milestones has been the recognition in July 2010 by the United Nations General Assembly of the human right to water and sanitation. The Assembly recognized the right of every human being to have access to enough water for personal and domestic uses, meaning between 50 and 100 litres of water per person per day. The water must be safe, acceptable and affordable. The water costs should not exceed 3 per cent of household income. Moreover, the water source has to be within 1,000 metres of the home and collection time should not exceed 30 minutes.

Ah, yes, the pesky UN again... the US shouldn't be beholden to that, it has so many more atrocities planned!