A chemical company in Lanzhou, capital of Gansu Province in northwest China, dumped concentrated chemical compounds into the Yellow River on Friday, but officials from the local environmental protection bureau said the situation was under control.

The company responsible, Lanzhou Xinxibu Vinylon Company Ltd, is considered one of the most-polluting companies in the country.

"Lanzhou Xinxibu Vinylon, a chemical company, dumped calcium hydroxide and calcium carbonate into the river on Friday. The materials had a minimal impact on the water quality of the Yellow River," Lu Zhaowen, director of the Pollution Control Department of the Lanzhou Environment Protection Bureau, told China Daily yesterday.

Lu said his bureau had received a report on Friday morning that white material had polluted a 30-kilometre stretch of the Yellow River, which traverses Lanzhou. The bureau dispatched officials and technicians to investigate.

The officials found that the chemical firm had illegally dumped chemical waste into the river. They fined the company and ordered it to stop polluting, the director said.

Tests by the Lanzhou Environment Protection Detection Station showed that the water quality had returned to normal three days after the spill. Further investigations are underway to determine whether the spill would harm to lower reaches of the river.

Lu said the spill had disrupted the water supply to some 2,000 households in the city's Xigu District for about 5 hours. The water supply in other parts of the city was normal.

Lanzhou Xinxibu Vinylon, which is located in Lanzhou's Xigu District and sits about 30 metres from the Yellow River, was previously listed by the State Environment Protection Administration (SEPA) as one of the 11 most-polluting companies in the country.

Huang Lihui, the company's general manager, said Lanzhou Xinxibu Vinylon did not have enough money to ensure pollution control.

"Our company lost some 10 million yuan (US$1.25 million) when it halted production for nearly month after being criticized by the SEPA early this year," Huang was quoted as saying by the West Business News.

Since late October, the river has been polluted four times by production waste and sewage.

Lu said local authorities would make more of efforts to better protect the river from pollution.

(China Daily December 26, 2006)