The market scale for China's sewage treatment industry stands at more than 500 billion yuan (about 60 billion US dollars), said Qiu Baoxing, vice construction minister, Tuesday.

China welcomes overseas capital to invest in sewage treatment projects, said Qiu at a press conference held here by the State Council Information Office.

In 2004, the discharge of sewage in China amounted to 35.6 billion cubic meters, of which half is released without any treatment. This has resulted in a serious degradation of the urban water environment, said Qiu.

China's urban wastewater treatment facilities fall short of what is needed, said Qiu. The construction of pipelines for sewage collection is often delayed due to funding shortages.

The central government has realized the importance of addressing this problem, said Qiu. Since 2000, China has stepped up efforts to build wastewater treatment factories. In 2004, the number of these factories in China have increased by 66 percent to 708 compared with 2000. The sewage treatment rate went up by 12 percent to about 45 percent in the same period.

China now encourages private and overseas investors to participate in the sewage treatment projects, said Qiu.

"We will try our best to safeguard the legitimate rights of the investors," said Qiu.