reservoirs were completed in 1989 in Susakadā, both 40,000 cubic meters. The water in Miyakojima is hard water, which is unsatisfactory both in taste and in the handling of metallic tableware. In 1999, adjustments to the pH were started at Sodeyama with water softening using lime softening in a pellet-reactor. Strict surveillance of the quality of the water supply is being done to prevent contamination through infiltration by fertilizers and other sources of local drainage. References Kuniki Shimoji, Nature of Miyakojima and Water in Miyakojima, 2001, Okinawa Kankyo Club. Miyakojima Water Supply Record Editing Committee. Miyakojima Water Supply Records, 1967, Miyakojima Water Supply Organization. Miyakojima Water Supply Organization, Miyakojima Water Supply Records 2 1996. Hirara City History Editing Committee, History of Miyakojima City,Vol. 1 Prehistory-Modern History, 1979, Hirara City. Yasuhiro Nakanishi, Ground Water Conservation in a sub-tropical coral island, 2002, Miyako Groundwater Conservation Council. Masaji Nakasone, Miyako Fudoki 1988, Hirugisha. Naha. Akira Tokuyama,Culture of Water in Miyakojima 2008, In second series of Nature and Culture of Miyakojima'' pp 99. . Footnotes Water supply and sanitation in Japan Landscape history Miyako Islands