Stockholm Vatten, a water treatment and distribution plant in Stockholm, Sweden, proves that the provision of safe drinking water can go hand in hand with environmental protection. Since 1933, the facility has not only supplied Stockholm and a dozen other cities with potable water but collected and purified domestic and industrial wastewater, which is then discharged into the Baltic Sea. Heat generated during the purification process is recycled to heat some 15,000 nearby apartments. Sewage sludge recovered during treatment is used to produce biogas, which runs up to 1500 buses and other public vehicles in Stockholm.