Is it illegal to charge for water or is it mandatory to give water when asked for by customer

Question

Is it illegal to charge for water or is it mandatory to give water when asked for by customer

Answer

If you are a food service establishment and you were to refuse water to a customer, or you were to attempt to charge for it, forget the legalities, this would be posted to Yelp.com within minutes. If you are beset with bums who only want free water, point them to your sign or menu that says We Reserve The Right To Refuse Service To Anyone.

Answer

I cannot find any law on the subject, one way or the other.