GENERALThis section reviews literature on technologies, regulations and projects for the use of treated wastewater to supplant water demands that would otherwise consume "higher"quality waters.Extent of Reuse. Pinjing et al. (2001) presented an overview of the current status and potential for water reuse in China. Agricultural reuse of municipal wastewater has existed since 1950, but most of the sewage used for agricultural irrigation did not meet water quality requirements. Industrial and urban reuse totaled 48,000 m 3 /yr in 1994 and the potential demand for reclaimed water in China was estimated to be 28,000 million m 3 /yr. Water reuse in Japan, on the other hand, has been highly developed. (Ogoshi et al., 2001) The annual reuse volume in Japan totaled 206 million m 3 /yr in 1998, and was greatly oriented toward urban reuse applications such as toilet flushing and industrial reuse. Of the more than 150 water reuse schemes identified in the United Kingdom, 21 grey water, 12 combined grey and rainwater, and 6 sewage effluent recycling schemes were identified (Diaper et al., 2001).