Water

8 glasses, 2 litres or even half a gallon. Thats the recommended amount that we humans need to drink to keep ourselves hydrated on a daily basis. Then there's your teas, your coffees, the washing up etc etc.... the amount we use, even waste in a day is incredible.
It's worth knowing that whatever quantity we use as a business, we are paying a fair price for it. 
Just like your electric and your water, with a few details I can be telling you just how much it will cost you for the future.