Fresh water is critical to human survival, settlement and development. Although fresh water is often viewed as an inexhaustible resource with unlimited renewable capacity, only 2.5% of all the water on earth is fresh, most of the world's fresh water supply is locked in glaciers and ice caps. Fresh water is, in fact, a finite resource, limited by availability constraints, affected by development, population growth, and polluting activities. Inefficiency and overuse of water are among the most problematic characteristics of water use in the United States . According to a report by the American WaterWorks Association, consumers in the United States could greatly reduce pressure on water supplies and save as much as $35 billion in water dcosts by using water-efficient home strategies and practices. Their survey of 3,700 households revealed that the use of more efficient plumbing fixtures along would reduce the amount of water used by Americans by more than three billion gallons per day. Americans could save a third or more o the water they now used in homes by reducing water consumption for landscaping, using non-leaking, low-flush toilets, aerated shower heads and top-loading washing machines, reusing water in washing machines and dishwashers, decreasing rinsing in washing machines and dishwashers, using water efficiently for personal hygiene uses and washing dishes and reusing water from washing and cooking for activities such as watering lawns and plants and washing cars.