Most of the used water will eventually become wastewater that must be treated before it can be discharged into nature. And that treatment uses a lot of energy. According to the U.S. Environmental Protection Agency, water and wastewater facilities account for more than a third of municipal energy budgets. On average, every Americans uses about 60 gallons of water per day for purposes that include flushing toilets, showering and doing laundry. This figure can easily double if outdoor uses, such as watering lawns and filling swimming pools, are also included. More >>