LEGISLATORS Albert Chan Wai-yip and Lee Wing-tat yesterday urged the Government to build Chek Lap Kok airport's aviation fuel supply depot on a deserted island in Chinese waters. In a meeting with the Deputy Secretary for Planning, Environment and Lands, Canice Mak Chun-fong, the two United Democrats said Juishan Island was the most suitable site. The Provisional Airport Authority, which has shortlisted four tenders for the construction of the fuel supply depot in four locations, will make a decision by the end of the year. One proposal is to build the depot on Tsing Yi. Another two would use sites in Bluff Point and Sham Wat, which are both close to Chinese waters. These sites were not favoured by the legislators because they are dolphin breeding grounds. The two legislators urged the Government not to locate the depot on Tsing Yi. ''If the depot is built on Tsing Yi it will create great environmental problems and will also affect the marine traffic near Tsing Yi,'' Mr Chan said. He said Mr Mak promised to carefully consider the environmental impact of the various proposals. Mr Chan said Juishan Island was the best option as it was not near residential areas.