An estimated 4 million people in one of China's most prosperous industrial towns have been deprived of drinking water for nearly a week, as a carpet of algae scum makes local lake water unusable.
The lake's most vocal defender, meanwhile, who has been drawing attention to its pollution for more than a decade, is languishing in police detention on what his wife says are trumped-up charges brought by vengeful local officials.
The sorry state of Lake Taihu, once a famed beauty spot 90 miles west of Shanghai, has drawn unusually harsh criticism from Beijing. "What's shameful is the [Wuxi] municipality's allowing its city's source of drinking water to be a dumping ground" for waste, the state-run China Daily said in an editorial Friday.
Wu Lihong, an environmental activist from Yixing, on the shore of Lake Taihu, has been saying the same thing for years. His temerity has resulted in being fired from his job, tailed by the police, beaten by hired thugs, and receiving repeated threats, according to his wife, Wu Jiehua.
In mid-April he was arrested. He complained to his lawyer last week that he had been tortured during interrogation. He is due to stand trial next week on charges of blackmail and extortion.
"My husband was trapped by the local government," claims Mrs. Wu. "They are very unhappy with what he has been saying and doing. They are 100 percent responsible for his arrest. They are doing their best to get their revenge."
Mr. Wu has been highly successful in drawing Chinese media attention to the way in which breakneck industrialization around Lake Taihu, China's third-largest body of fresh water, has turned it into a sewer.
"The lake is in one of the world's most heavily populated areas, with the highest rate of economic development in the world," points out Ma Jun, head of the Institute of Public and Environmental Affairs, a research group in Beijing. "The water resources there are under huge pressure."
Since Tuesday of last week, a bloom of algae has covered 70 percent of the lake's surface, according to local reports, turning it blue-green and making tap water stink of decomposing vegetation. Several million residents of Wuxi have been forced to rely on bottled water, and local authorities said Sunday they did not know when normal water supplies would be resumed.
Experts blame the explosion of algae on unusually warm weather and low water levels, compounded by the unnaturally high levels of nutrients in the lake, pumped in by polluters. Nitrogen and phosphorous, occurring in effluent from chemical factories, household waste, and agricultural run-off favor development of algae.
Environmental activists, using official data, have fingered 300 local factories – including ones owned by the Swiss elevator manufacturer Schindler, the Japanese electronics firm Sharp, and South Korea's Samsung – as particular offenders. "This part of China has become the workshop of the world," says Mr. Ma. "It supplies many Western countries and companies. We export the products, but we dump the waste in our own backyard."
The latest catastrophe occurred despite efforts by local and central government agencies over the past decade, costing $1.3 billion, to clean up the lake. All polluters were ordered, without result, to halt production in 1999, and water has been diverted from the Yangtze River to try to flush out the lake, to little avail.
Lake Taihu is not an isolated case in a country where economic growth has ridden roughshod over environmental concerns. There are tentative signs, however, that this might be changing.
One is the tone of the China Daily editorial, which warned that "this disaster should put many more cities on guard. It should be a wake-up call to many other local government leaders to move away from their overemphasis on economic growth."
Another possible indicator was the decision last week by the mayor of the southern city of Xiamen to suspend approval of a massive chemical factory slated for construction near a residential district. The plan sparked days of street protests.
Environmental activists are looking to Wu's trial June 12 for evidence to confirm or deny the trend.
"The authorities claim this is a criminal case," says Ma. "They need to show real evidence to the public, otherwise people have the right to question why he, a very outspoken critic" of officials and industrialists in Wuxi, should have been targeted.
"The work he has done to report polluters and to preserve the water resources of his home town is very good work," adds Ma. "That deserves support."