In a ruling aimed at resolving months of debate, the national environmental regulator on Thursday ordered that most of the plastic sheeting covering the lakebed in Beijing's Yuanmingyuan (the Old Summer Palace) should be removed.

The State Environmental Protection Administration (SEPA) said it upheld the conclusions of Tsinghua University's environmental impact assessment, and that natural materials such as clay should be used to help prevent seepage instead.

Pan Yue, SEPA vice-minister, said in a statement yesterday that a comprehensive plan for the park's water supply should be made in line with environmental requirements.

Yuanmingyuan Administrative Bureau was criticized over the US$3.6 million project after March 22 -- World Water Day -- when Zhang Zhengchun, from Lanzhou University's Life Sciences School in Gansu Province, found the sheeting being put down on the drained lakebed.

Park officials said the project would save water by stopping it leaking from the lake, but Zhang and other environmentalists said the membrane could cause serious damage to the environment.

Zhang said many plant and animal species in and around the lake would die and that the water would become stagnant and filthy. There were also concerns that reducing drainage would affect the capital's already low groundwater levels.

The SEPA called for a stop to the project on March 31 after Beijing Municipal Environmental Protection Bureau revealed it had not received approval from environmental authorities before commencing work the previous September.

The project was restarted and completed in the first week of April despite this, and a public hearing, the first of its kind, held on April 13 with park authorities, scientists and environmentalists taking part.

The SEPA announced on March 17 that Tsinghua University would undertake an environmental impact assessment, after criticizing the park authorities six days earlier for delaying such work.

Environmentalists are now hailing the SEPA's latest ruling to have the sheeting removed, with Zhang calling it a "perfect solution."

Speaking yesterday afternoon, the director of the Yuanmingyuan Administrative Bureau, Li Jingqi, said the bureau would study how to implement the SEPA's resolution.

Liao Xiaoyi, president of the Global Village of Beijing, a non-governmental organization, also welcomed the decision.

(China Daily, China.org.cn July 8, 2005)