The clean-up of the oil that leaked from a cargo ship on the Huangpu River the day before yesterday will take some time and the effects of spill will be felt for one or two years, as the dykes and wetland along the river have also been contaminated, according to the Shanghai Maritime Authority.

At 4:50 am on August 5, the fuel tank of the anchored vessel Changyang, operated by the China Shipping Group, reported being rammed by an unidentified boat, near Wujing in the Minhang District.

The collision put a big hole in the fuel tank of the ship, resulting in 85 tons of fuel being spilled into the waters of the upper reaches of the river, where there are 13 water supply stations serving both industrial and residential users.

An area of 150,000 square meters of water and land has been polluted, making it the most serious accident on the river since 1996 when several barrels of sulphuric acid fell into the water and later were fished out intact according to Zhou Zhengbao, a spokesman for the Shanghai Maritime Authority, which is responsible for safety issues on the water.

Though oil spill professionals were called to the site immediately to prevent the spread of the spill and huge quantities of oil have been removed, the spread of the spill along a more than 10-kilometre- stretch of water still poses a serious problem for authorities.

"Up till now, water supplies have not been affected thanks to the quick prevention measures,'' Zhou said. "But the oil still in the water and on the banks is still a potential threat.''

A dozen experts from the water authority, environmental protection organs and other departments were called to the site yesterday (August 6) to assess the spill and discuss measures to minimize the damage.

As the use of chemicals to disperse the oil will affect the water quality of the water supply stations, the clearing is limited to the use of manpower and mechanical methods.

The pollution has covered coastal wet land and seeped into the mud which is abundant with biological species, which is a serious worry for environmental experts because of its possible long-term effects.

They agreed that it is urgent but very challenging to clean up the oil stuck on the dykes and in the seaweed as rising waves will wash the oil back into the water again.

The boat responsible for the accident has not yet been identified and the maritime authority has notified neighboring provinces to keep a close eye on any suspects, and nine patrol boats have been sent out to look for it, he said.

(China Daily August 7, 2003)