No major incidence of water pollution has been detected on a river that serves as a source of drinking water for nearly 5 million people in central China's Wuhan City after four vessels carrying methanol were engulfed by fire on Sunday, local authorities said on Monday.

Workers detected up to six milliliters of methanol per liter in the Hanjiang River, far less than the national standard of 200 ml per liter for alcohol production, and it is unlikely that the water has been badly contaminated, said a spokesman with the city's environment monitoring authorities.

Four docked vessels carrying a total of 576 tons of methanol caught fire at the Chenjiadun pier on the river Sunday afternoon, injuring one sailor. One vessel loaded with 49 tons of methanol sank soon after it caught fire.

"But most of the chemicals had been burnt off before some seeped into the river and no sign of a large-scale leakage of methanol has been found," the spokesman said.

The water authorities said that the supplies of drinking water to local residents have not been affected and the Zongguan Water Plant in Wuhan is still taking water from the river to serve Wuhan's 5 million residents with the operation of five pumps.

A spokesman with the plant said if contamination was detected in the river, it could stop taking water from the river in one minute, and its water reserves could guarantee consumption for up to three hours for local residents.

The four vessels belong to a water transport company from east China's Jiangxi Province. They were carrying methanol used to produce pesticides from central China's Henan Province to eastern Jiangsu Province when the fire broke out.

Methanol is a colorless, toxic and flammable liquid, and exposure to it may cause headaches, severe abdominal, leg and back pains, loss of vision, and even death.

Experts are still monitoring the water quality. An investigation into the cause of the fire is underway.

(Xinhua News Agency September 4, 2007)