Beijing has made great efforts in recent years to improve water quality, according to Bi Xiaogang, vice director of Beijing Water Authority.

Updating the press on the water environment amelioration in China's capital city and host of the 2008 Olympic Games, Bi said great importance has been given to sewage treatment. At the moment, nine of the 14 planned large-scale sewage treatment plants have been built and the five remaining ones are under construction.

In 2006, sewage treatment reached 70 percent in the urban area, with 962 million cubic meters of waste water treated. In the city's eight central districts, the rate of waste water treatment reached 90 percent.

Beijing has also emphasized the ecological protection at the upper reaches of its 52 waterways with a total length of 520 kilometers. More than 300 waste water treatment plants have been built in these areas.

In addition, the urban areas have seen the tear-down of 410,000 square meters of illegal buildings to alleviate pollution threats to the rivers and lakes. Water plants have been planted on some of the waterways to clean up the underwater environment. Oxygen pumping equipments have been placed on the Tongzihe River to raise the oxygen level of the river water.

Beijing is thirsty for water especially after seven successive years of drought since 1999. Under such circumstances, the authorities have continued to supplement recycled water into the waterways to keep the water clean. Another supplement is rain water. Beijing puts some 10 million cubic meters of rain water into the rivers and lakes yearly.

The efforts have resulted in a remarkable improvement of the water quality. For instance, the chemical oxygen demand (COD) in the Qinghe River dropped to 11.9 per milliliter in 2006, as against 37.2 in 2004, Bi said.

In 2007, he said, a number of new sewage treatment plants will be built in suburbs and rural townships, the water supply to Miyun Reservoir will increase, water quality monitoring will be enhanced and the environment of the 29km-long urban rivers within the Sixth Ring Road will be upgraded.