Here in Singapore, we've had a national water purification process for some years now. The water from sewers are purified (by reverse osmosis, plus other processes to remove the toxic stuff) and mixed with reservoir water for national consumption. Everyone in Singapore drinks it (ever transited or visited at our Changi Airport?) - yucky to the mind, no difference after a while. So, yeah, all Singaporeans and our esteemed visitors have been drinking it. Bottoms up! (Incidentally, our Cabinet Ministers drank it on national TV to kick off.)