As population and industry grow, water demand increases, and water supply becomes more of a problem. It has been estimated that the total gross water intake for all purposes in the United States will exceed the total available water supply of 650 billion gal/day (2.5 billion cu m/day) by the year 2000. Therefore, wastewater reclamation will become a more significant means of augmenting water supply. Reclamation of municipal wastewater for industry, nonpotable domestic usages, and groundwater recharge has been practiced in the United States over the past several decades. In a 1971 United States Environmental Protection Agency supported (EPA) nationwide survey, it was estimated that current reuse of treated municipal wastewater for industrial water supply, irrigation, and groundwater recharge was 53.5 billion gal/yr, 77 billion gal/yr, and 12 billion gal/yr, respectively.