1. Sewage irrigation: The utilization of urban sewage in Beijing began with sewage irrigation. In the early 1950s, the industrial wastewater from Shijingshan Iron and Steel Plant was used for irrigation in Shijingshan area. With the construction of urban sewage pipelines and sewage pumping stations, the sewage irrigation area is expanding. At present, there are more than a dozen irrigation canals along the four rivers of Qinghe, Bahe, Tonghui and Liangshui in the urban area. Sewage irrigation is mainly concentrated in Fengtai District, Chaoyang District, Daxing County and Tongzhou District, located in the lower reaches of the urban area. In 200 1 year, the total agricultural water consumption in Beijing was 46 million m3, accounting for 2.8% of the total agricultural water consumption.

2. Water facilities in buildings: In 1980s, sewage was treated and reused in cities. Reclaimed water reuse is first implemented in a single building, that is, the sewage or less polluted washing water generated by the building itself is treated and used for flushing toilets and municipal miscellaneous water such as courtyard greening. 1987, the municipal government formulated and promulgated the Trial Measures for the Construction and Management of Reclaimed Water Facilities in Beijing, stipulating that hotels, restaurants and other public buildings with a building area of over 20,000 square meters and over 30,000 square meters in the whole city should be equipped with reclaimed water facilities. This experimental plan has further promoted the construction of water supply facilities in buildings. According to statistics, at present, 200 sets of reclaimed water facilities have been built in Beijing, including 50 sets of 100 in normal operation and more than 0 sets of100 under construction, and the consumption of reclaimed water is about 24,000 cubic meters per day.

3. Regional sewage recycling: In 1990s, the construction progress of Beijing sewage treatment plant was accelerated, which created better conditions for urban sewage recycling. 1999 worked out the comprehensive utilization scheme of reclaimed water in Gaobeidian sewage treatment plant. Part of secondary effluent from Gaobeidian Sewage Treatment Plant is sent to Huaneng Gaobeidian Thermal Power Plant and No.1 Thermal Power Plant as cooling water for power plants, and part is sent to No.6 Water Plant (industrial low-quality water plant). After further treatment, part of it is used as industrial cooling water in the industrial area in the southeast suburb, and the rest is sent to Cheng Nan area as green water for parks and roads. The total reuse amount of sewage is 30. The project has been completed and put into operation.