In an effort to prevent a large oil spill from polluting a main source of Shanghai's tap water, a sluice gate in Jiangsu Province was opened yesterday afternoon to release water from Taihu Lake at the upper reaches of the Huangpu River.

　　The oil spill is downstream from the tap-water source, but due to low water levels in the river officials were worried the oil would travel upstream. To stop that from happening, they opened the Taipu River Sluice Gate to raise water levels and push the spill further downstream, according to Zhang Zhenyu, a spokesman for the city's anti-flooding headquarters.

　　The tap-water source supplies about 70 percent of the city's water. PLA soldiers were rushed to the scene yesterday in an effort to clean up as much of the spill as possible before tomo-rrow's high tide on the river.

　　According to Zhou Zhengbao, a spokesman for the Shanghai Maritime Safety Administration, more than 2,000 people and 173 vessels are working to clean up the spill area, which is about 10 kilometers long.

　　The soldiers began removing oil-soaked plants from along the banks of the river at about 3:30 am yesterday.

　　After a stretch of the banks was cleared of polluted plants, workers began to hose the area to push the oil back into the water where it is easier to clean up, according to the Shanghai Maritime Safety Admi-nistration.

　　The work is not only dirty, it also poses health risks as many of the soldiers suffered from allergic reactions to the toxic oil, which spilled after a small vessel collided with a cargo ship last Tuesday.

　　More than 100 soldiers were treated at a temporary clinic set up along the river bank.

　　Nine oil-blocking nets were also placed along the river yesterday to contain the spill, which the government hopes to have cleaned up by tomorrow when the tide is expected to rise, possibly making the situation worse.

　　Local officials together with counterparts in neigh-boring Jiangsu and Zhejiang provinces are still searching for a 500-ton vessel blamed for the spill.

　　When the vessel collided with an anchored cargo ship early in the morning last Tuesday, it caused 85 tons of fuel to spill into the river.