■Liede Wastewater Treatment PlantSituated east of Liede village of Tianhe District and at the north bank of the Pearl River close to the South China Bridge, Guangzhou Liede Plant is the city's second large-scale wastewater treatment plant. Occupying an area of 390,000 square meters, it collects and treats the wastewater discharged mainly from the central city area of the North Waterway of the Pearl River, including the wastewater from Xihao Stream, the self-discharge system of the Pearl River, Donghao Stream, Ersha Island and some parts of Tianhe District, serving an area of 228 square kilometers and a population of 2.96 million.The plant is constructed in three phases. The first stage, approved to start in 1991, was put into operation in 1999 with a designed treatment capacity of 220,000 tons of wastewater per day and supported by a biological treatment technology of two-section (AB) adsorption and degradation. The second phase was started in April 2002 and put into operation in October 2003 with a daily treatment capability of 220,000 tons. The technology adopted is composite alternating activated sludge processing. The third stage, started in 2004, was put into operation in November 2006 with daily handling capability of 200,000 tons, and backed up by the modified A2/O (anoxia/anaerobic/benign oxygen) technology. Upon completion of the three phases, the total treatment capability will reach 640,000 tons a day.Since operation, a scientific management system has been constructed by incorporating the three management systems of ISO9001 in quality, ISO14001 in environment and OHSAS18001 in occupational health safety to ensure that the water standards exceed the B criteria of the national A-level. The factory also leads the country in terms of technical innovations and renovations, R&D of the equipment management software and the long-distance communication system between pumping stations, particularly the sealed deodorization technology.