China's heavy industries have tipped so much waste into the river that enormous stretches of it, amounting to over a third of its entire length, cannot be used at all anymore, either for drinking, fishing, farming or even in factories, according to criteria used by the United Nations Environmental Programme.
The Yellow River is the second-longest waterway in China after the Yangtze and the sixth-longest in the world, at 3,398 miles. Originating in the mountains around the Tibetan plateau at Qinghai, it empties out into the Bohai Sea on China's East coast.
It is tremendously important in Chinese culture, and the first signs of civilisation in northern China sprang up around the Yellow River basin, despite its frequent and devastating flooding. The river flows through are China's industrial heartland, and many of the regions it passes are short on water.
But in recent years it has suffered from heavy pollution and from projects to divert its waters to cities. Li Xiaoqiang, a spokesman for the Yellow River Conservation Committee, said 4.3 billion tonnes of polluting effluent were tipped into the river last year, mostly by factories.
Mr Li called for "urgent action" to save the river, and added forlornly: "I wish that a harmony could be achieved between development, utilisation and protection of the river someday."
He said a move by the State Council, China's cabinet, to force factories to save energy and reduce pollution could eventually pay dividends. "It is a good thing, but it will take an arduous effort," he said.
Two years ago, the pollution levels of the Yellow River gained national attention when a stretch of water around the western city of Lanzhou turned magenta. Xinhua, the state news agency, blamed the "red and smelly" slick on a sewage discharge.
China boasts some of the world's most polluted cities. In February, 200,000 people had their water cut off in central China because of a spill into a river system. In September, a major lake near Kunming was heavily polluted with arsenic, leading to several cases of poisoning.
In one of China's worst cases of river pollution, potentially cancer-causing chemicals, including benzene, spilt into the Songhua River in November 2005. The northeastern city of Harbin was forced to sever water supplies to 3.8 million people for five days.
Pollution in China's waterways remains "grave," according to a June report by the Ministry of Environmental Protection on the state of the environment in 2007. More than 20 per cent of water tested in nearly 200 rivers was not safe to use, it said.