Spread out between the Qinghe industrial zone and the Olympic Park in Beijing's Haidian district is a new, 30-hectare plant for treating and recycling waste water. Each second, more than four tonnes of waste water comes into the plant the colour of chocolate and leaves crystal clear. Yang Xiangping , general manager of the state-owned Beijing Drainage Group that owns and operates the facility, says the plant's technology is some of the most sophisticated in the world, removing not only toxic pollutants, but also nutrients such as nitrogen and phosphorus that can build up and cause algae outbreaks. 'Beijing will win the battle against [water] pollution and shortages,' he said. Mr Yang's confidence partly comes from the fact that the Qinghe plant, which took nearly 1 billion yuan and more than five years to build, is neither the biggest nor the most advanced waste-water treatment plant in Beijing. The capital now has nine huge water-treatment facilities, each day cleaning 2.5 million cubic metres of waste water - about as much as the city produces. Half the amount of water treated is recycled. While tens of thousands of water-treatment plants on the mainland struggle for the official support needed to guarantee the quality of their output, Beijing is going at full throttle to meet top international standards, regardless of the cost. According to the Beijing Water Authority's drainage department director, Qi Jingjun, a successful tactic in the capital's overall water strategy was the decision to change the city's industrial structure. Within half a decade, Beijing shed its third-world industries and acquired those of a developed society, he said. Gone is Beijing Steel, one of the mainland's largest steel companies, and the many smaller but equally energy-intensive industries and environmentally damaging factories and plants. In their place are businesses based on advanced machinery, information technology, cars, pharmaceuticals, education and scientific research, and development. At the same time, the city government made huge investments in its water-treatment infrastructure. By the end of last year, the city had about 4,000km of drainage pipes, about twice the distance between Hong Kong and Beijing. The pipes are monitored and maintained by tens of thousands of digital sensors and robots, which detect leaks and remove blockages. The city has also built seven water-recycling facilities that together supply nearly a million cubic metres of water a day. 'We are learning from the latest experience of the United States, Japan and Israel, and developing equipment and technology suitable for Beijing,' Mr Qi said. In all, Beijing has invested more than 10 billion yuan in water-treatment infrastructure since 2000 and conservative estimates put the operational costs of the facilities last year at 1 billion yuan. Mr Qi says the cost of water treatment is mainly covered by a charge included in water bills paid by the city's residents, but was lower than elsewhere in the country because of the efficiency of the technology. 'Per-unit water-treatment expenditure in Beijing is actually lower than other cities on the mainland,' he said. But Beijing consumers still pay the highest water prices on the mainland, with a cubic metre of tap water costing 2.8 yuan. Shanghai consumers pay about one-third that price. At the Qinghe plant, the cost of treating one cubic metre of waste water is 0.75 yuan, and double that to recycle it for reuse. At another factory in Beixiaohe, where the best technology has been adopted, a cubic metre of recycled water can cost 3.5 yuan, well above the one yuan per cubic metre price for industrial consumers. 'The water-treatment charge of [0.9 yuan per cubic metre] is absolutely not enough,' Dr Wang said. 'Most of the infrastructure and operating costs have to be paid by the city and national debt.' There is no official figure, but some researchers estimate that less than a tenth of the newer water-treatment plants on the mainland are running at full capacity because most of them do not have the financial strength to sustain operations. 'It's not only the cost of electricity, chemicals and workers,' a researcher said, 'but also the burden of paying back loans and taking care of the waste removed from the water.' In a 2004 paper in the Southwest University of Nationalities' Natural Science Journal, professors Liu Dong and Zhou Xiantao estimated that most of the water pollution on the mainland comes from small and medium-sized cities. 'More than 80 per cent of the waste water is coming from small cities, townships and villages where public finances are weak, incomes are low and water-treatment facilities do not exist,' they wrote.