THE soldiers unloaded their trucks faster than the Songhua river flowed.

Their challenge was to fill tanks with charcoal to filter water for China’s northernmost city once the poisonous slick of benzene has floated by and the taps are turned on again. Hundreds of men were emptying their sacks as fast as they could into deep holds at the Harbin No 3 water supply plant that pumps 80 per cent of the city’s needs.

It is not an exaggeration to say that what has been happening in Harbin happens in some shape or form almost every day across China. Be it a horrific mine accident or choking pollution, China is paying a heavy environmental cost for its breakneck growth.

Nearly four million of Harbin’s nine million residents have been without water since the middle of the week after the Government shut off the pipes until the contamination that had spewed out from a petrochemical factory explosion upstream more than two weeks ago had flowed past. Officials have promised that the stoppage will last no more than four days.

Central government has sent investigators to assign responsibility for the crisis, and state media have attacked authorities for hiding the extent of the problem as they did with the Sars epidemic a couple of years ago.

Queues of hundreds of people waiting for water long snaked around an army tanker. Neighbours jostled and argued. And then the military stepped in. “It’s one container per person. That’s it,” the driver said. People lined up their cooking pots, rubbish bins and buckets.

Tempers frayed. “I’ve been here for six hours. There’s just not enough water for everyone,” grumbled one woman.

When the water is switched on again, it could be hours or even days before it will be pure enough to drink. Warnings are being issued to use the first flow only to flush the toilet because benzene, an industrial solvent, is highly carcinogenic.

To speed up the process, the charcoal is being used to filter any remaining benzene from the water. Li Guibai, a Harbin engineering professor, said: “It can take two years for benzene to decompose, but because it’s heavier than water and doesn’t mix we can use charcoal to filter and absorb it.” Sacks by the ton are being shipped into Harbin from all across China.

The disaster that has cut off water to a city the size of London is a symptom of far wider problems. More than 70 per cent of China’s rivers are contaminated, more than a third of the country is plagued by acid rain and in the past 50 years it has lost more than 1,000 lakes. China is home to seven of the ten most-polluted cities in the world and urban smog causes more than 400,000 early deaths a year, the International Energy Agency says.

Harbin may have a water problem this week, but international assessments estimate that 980 million of China’s 1.3 billion people drink partially polluted water every day. “Our country’s environmental situation remains grim,” Wen Jiabao, China’s Prime Minister, said this week.

In the hunt for profits and market share, factories and power stations often ignore environmental rules. Even those that have installed equipment to process waste sometimes leave it unused in order to cut costs.

()Others run it for too long, risking accidents from human error or faltering machinery. This may be particularly tempting in the petrochemical sector, which supplies the building blocks of everything from fertiliser to drugs, and is racing to keep up with demand.

China has promoted economic growth to keep its people content and the Communist Party in power. But now that people have higher incomes they are starting to worry about the quality of life, and that is leading to the very social unrest the party most fears. This summer, hundreds of angry farmers rioted in eastern Zhejiang province about effluent from a pharmaceutical plant which, they said, had ruined crops. Officials admit pollution costs China 8 per cent to 15 per cent of its gross domestic product.

Zhu Chunquan, of the WWF, said of the Harbin crisis: “This accident is like a warning, and an opportunity for all stakeholders in China to protect the natural ecosystem.”

China had plenty of laws and regulations to protect its environment, but many, if not most, were ignored. “Enforcement is a big challenge,” Dr Zhu said. For days on end, a yellow-brown smog can hide the skyscrapers of Beijing, lifting only when a wind blows across from the Gobi desert. In province after province, factory towers belch smoke above green paddy fields. Roadsides everywhere are blanketed with a carpet of plastic bags and discarded bottles.

Environmental activists say that the greatest problem is the lack of awareness. This week the State Council, or Cabinet, set an ambitious target for a significant improvement in environmental quality by 2020. Competing interests may hinder that. Beijing also aims to have quadrupled its economy by 2020 compared with 2000.

Only this week an explosion in southwestern Chongqing at another chemical plant killed one person, forced the evacuation of more than 6,000 people and raised fears of a second benzene spill. Officials gave house-to-house warning to residents not to use river water. Mr Wen quickly issued instructions demanding that safe drinking water be provided.

But now other cities lie in the path of the 50-mile slick of pollution oozing down the Songhua river. It will enter Russian territory on Tuesday or Wednesday and is expected to reach water collection points for the city of Khabarovsk on December 4. Russian media described the unfolding crisis as a big ecological catastrophe. Public drinking water taps in the city will be shut off days before the benzene slick reaches the city.

In Harbin officials were vague about exactly when the water supply would resume or how long it would take to flush out all trace of the toxic chemical. But they were certain that Harbin’s famed Ice Festival would begin, as usual, on January 5.

The ice needed for the vast sculpted lanterns that will draw tens of thousands of tourists to China’s coldest city will not be cut out of the Songhua river for another month. “The festival definitely won’t be affected,” a city spokesman said.

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