Environment authorities in Jilin have reassured local people that the chemical pollution in a tributary of the Songhua River will have little influence on water quality.
Jilin Provincial Environmental Protection Bureau also confirmed the culprit as Changbaishan Jingxi Chemical Co, based in Jilin City, capital of northeast China's Jilin Province.
The company dumped 10 tons of industrial waste into the Mangniu River on Monday, which formed a five-kilometer slick of mainly xylidine. It has been ordered to stop production and culprits have been punished.
High or repeated exposure to xylidine can damage liver and kidneys, and even cause death.
An interception dam and another two dams of active carbons have been built in the Mangniu River to slow the slick's speed and absorb pollutants.
The bureau has now lifted the ban prohibiting people along the Mangniu River from using river water, and no cases of human or animal poisoning have been reported.
The slick is expected to arrive in Harbin, capital of Heilongjiang Province, in 12 days at the current speed, said Yu Guiyun, deputy director of Harbin Environment Surveillance Station.
"The concentration of the pollutants will be greatly diluted and will not pose any danger after such a long time," Yu said.
"Normal water supply can be guaranteed," said Liu Yurun, manager of Harbin Water Supply and Discharge Company, which supplies most of the urban population of 3.8 million.
Liu said that they had carried on using active carbons to filter water after the chemical slick in the Songhua River in November.
Residents were much calmer than on Wednesday, when long queues formed as residents stockpiled water.
"Didn't you see the news?" said a 65-year-old man surnamed Wang. "It (the pollution) is not a big deal,"
"Even if there is a little pollution, I can't see it being more serious than that one last year."
(China Daily August 25, 2006)