A pollution spill on a branch of the Yangtze River has affected water supply for 200,000 people in central China's Hubei Province, according to local authorities.

The serious pollution on the Hanjiang River has affected residents along its three tributaries, namely the Xinglong, Tianguan and Dongjing rivers, local environmental and water company sources said.

The latest tests on water samples from the three tributaries showed the permanganate index as well as ammonia and nitrogen levels were slightly higher than the standard.

The water became red with large amounts of bubbles, said Gao Qijin, head of Xingou Township Tap Water Company in Jianli County, which is along the Dongjing River.

He said the pollution was found on Sunday afternoon and the company immediately stopped drawing water from the Dongjing River as it did not meet the tap water standard.

Water supply has been cut for about 60,000 residents in the town. Five schools have also stopped classes, while many could not provide food to students.

Residents now have to rely on bottles of purified water and limited underground water. The town does not have alternate emergency underground water sources.

Qianjiang City had ordered tap water companies in five towns to stop drawing water from the polluted sections, said Zheng Jiarong, vice mayor of the city.

Three have to exert to emergency water supply while the other two were still facing water outage.

Local authorities were assessing the effect of water pollution on farming, but no result had been available.

Local authorities have shut down a gate through which the Hanjiang River pollution spilled into the affected rivers and began on Tuesday afternoon to link water from Changhu Lake nearby to dilute the pollutants.

"The fresh water is flowing at 100 cubic meters per second and is expected to arrive on Wednesday morning. Then the water supply would resume once the dilution is over," said a Jianli City official.

The environmental protection authorities were investigating the source of the contamination. Four inspection teams have been dispatched along the rivers to identify the polluters.

The government was being cautious against the case the stoppage would cause mass fears or panic buying of water, local authorities said.

Hanjiang River was polluted in September when a paper mill upstream dumped waste water directly into the river, causing a week-long water cut in some areas.

Last week, water pollution from homemade fertilizer affected the drinking water of 9,000 people in two towns in southwestern Yunnan Province and killed 20 tons of fish in a fishery.

Police have detained the farmer Zhou Shunfu, who dumped 120 tons of waste residues with phosphor onto his own fields, thinking that it could be used as fertilizer, and wiped out a neighbor’s fish farm.

(Xinhua News Agency February 27, 2008)