The average American uses 90 gallons of water each day [PDF], of which only about two gallons go toward drinking and cooking. In fact, we use twice as much water—four gallons—washing dishes than we do in preparing and eating our meals. Laundry uses, on average, 8.5 gallons of water a day per person, while 25 gallons of water a day per person go toward lawn watering and pools. But our topic today, toilet flushing, requires between1.5 and five gallons per flush, depending on the age of toilet one uses. Combined, the typical American flushes away 24 gallons of water each day, nearly a quarter of our total water consumption. We don’t naturally quantify all that flushing in dollars and cents, but like everything else in life, toilet water costs money. The OGWDW estimates that the average cost of water is $2 for 1,000 gallons, or, approximately 4.8 cents per person, per day, for 24 gallons of toilet water. In total, the roughly 300 million Americans spend more than $5 billion dollars a year flushing their toilets.
Source: Dan Lewis, "Americans Flush $5 Billion Down the Toilet Every Year," GOOD, Mar. 28, 2012. http://www.good.is/post/americans-flush-5-billion-down-the-toilet-every-... [verified 4/25/14]