So, where does all of a household's tap water go? Roughly one-quarter ends up flushed down the toilet. Nearly as much goes for bathing. Clothes washers use 8 gallons per person daily, and homes with garbage disposals and automatic dishwaters send another 4.1 gallons down the drain. And then there are plenty of outdoor uses. Nationally, lawn watering and swimming pools consume roughly 25 gallons per day on average, and car washing another 2.5 gallons. In contrast, cooking and drinking consume, on average, a mere 2 gallons per person daily.
These statistics disturb hydrogeologist Peter J. Schreuder, a Tampa-based water consultant who also teaches at the University of South Florida. He bristles at tap water used for purposes other than ingestion. Throughout much of the world, water is a tight commodity. Even in the United States, competing interests have been waging heated battles - usually in the courtroom - over rights to the nation's supplies of freshwater. Ironically, Schreuder observes, municipally delivered tap water never was intended as a source of irrigation water for gardens or slurry for food scraps entering garbage disposals. Nations began providing water to individual homes as a way to fight disease. Subsidizing the delivery of disinfected - and often deodorized - water was justified as a means of improving public health. However, he points out, that was before most people had toilets, much less showers and garden hoses.