The quality of water in the upper reaches of the Yangtze River and the Three Gorges Dam, the world's largest hydroelectric project, has improved in recent years.

The improvement comes after five regions, including Chongqing, Hubei and Sichuan, built more wastewater and garbage treatment plants, Zhang Lijun, deputy minister of environment protection, said in Chongqing Thursday.

The regions had 240 wastewater treatment plants at the end of 2009, 114 more than in 2007. In addition, the regions had 300 garbage treatment plants, Zhang told a conference on Yangtze River water pollution.

Some 88.1 percent of the water in the Three Gorges Dam and the upper reaches of the Yangtze River was of grade I, II and III quality last year, an increase of 19.1 percentage points from 2005.

China uses a six-grade classification scheme for water quality. Grade I is the best. Water no worse than grade III can be used for drinking, sometimes after treatment. Water worse than grade V cannot even be used for irrigation.

Chongqing has rejected applications of high-polluting projects to protect the Yangtze River. Last year, it rejected 136 high-polluting projects that has a combined investment value of 18.8 billion yuan (US$2.8 billion), said Tan Xiwei, vice mayor of Chongqing.

(Xinhua News Agency July 2, 2010)