GUANGZHOU: Measures were launched on Friday to try to disperse a toxic cadmium slick on Guangdong's Beijiang River.

The slick, caused by excessive discharges from Shaoguan Smelting Plant on December 15, had stalled by the dam gate at the Baishiyao Hydropower Plant near Yingde, 90 kilometres downstream from Shaoguan, said Huang Zhensheng, spokesman of Yingde municipal government in the southern Chinese province.

To ensure water safety to downstream residents, the local environmental watchdogs on Friday began dumping 1,200 tons of polymer chemicals into the polluted area to try to neutralize and dilute the water.

"Toxicity is expected to be reduced by 30 per cent by the chemicals," said Xu Zhenqiang, vice-director of South China Environmental Science Institute.

Tests showed the cadmium content of the toxic slick dropped to 0.032 milligrams per litre on Friday, still higher than the safety level of 0.01 milligrams per litre.

The content had reached 0.1 milligrams per litre on Tuesday.

As Baoshiyao Hydropower Plant could not stall all of the toxic flow, a small amount of polluted water is still flowing downstream, said Xiao Yanbing, an official with the Guangdong Provincial Environmental Protection Department.

The slick is 110 kilometres upstream from Qingyuan, 180 kilometres from Foshan, and 250 kilometres from Guangzhou.

As the speed of the flow is 4.5 kilometres per day, he said he believed the cadmium content would return to normal water levels when the slick arrives in Qingyuan.

Though the polluted water has not yet reached Guangzhou and Foshan, local authorities of both cities have initiated drinking water emergency response schemes.

Both cities are holding water testing more frequently than ever before, examining equipment and facilities for drinking water supplies in case of emergency, Wang Hongshan, spokesman of Guangzhou municipal government, told China Daily on Friday.

Source: China Daily