The polluting blue-green algae outbreak in the Taihu Lake last May disrupted the water supply to half of the 2.3 million residents in Wuxi, Jiangsu Province.

It is estimated that the cost of providing fresh water to local residents totaled 50 million yuan (US$7.14 million) in June alone, and the annual economic loss reached 5 billion yuan.

The algae's dense growth and its decomposition depletes the supply of oxygen in the lake, leading to the death of other plant and animal life in the lake. The deadly process is known as eutrophication.

After the water crisis, Jiangsu province officials vowed to take strict environmental standards to reduce pollution, even if that means a slowdown in economic growth.

The province has planned a total of 108 billion yuan investment to curb the eutrophication of Taihu Lake within five years, and to clean up the lake in eight years.

Statistics show that emissions of chemical oxygen demand, a key measurement of water pollution, and ammonia nitrogen, a major chemical compound that boosts the growth of blue-green algae, from area textile, chemical, iron and steel, paper making, electroplating, and brewing industries account for 65 percent and 63.4 percent respectively of the total industrial pollution in the Taihu Lake basin. Untreated sewage dumped into the lake is another major factor.

Jiangsu officials have pledged that by the end of 2008 all 2,150 polluting companies operating in the lakeside cities will be closed.

The Jiangsu provincial environmental protection bureau also issued what is considered the strictest environmental standard in the nation - DB32 Discharge Standard of Main Water Pollutants for Municipal Wastewater Treatment Plant and Key Industries of Taihu Area - which took effect at the beginning of this year.

In addition, officials have also launched large-scale ecological restoration experiments across the province's developed southern region.

(China Daily April 21, 2008)