The good, the bad and the ugly
Wuxi, a city in East China's Jiangsu Province that recently experienced a serious drinking water crisis, has two contradictory examples of water treatment. The bad example is the heavily polluted Taihu Lake; the good one is the Lihu Lake, an inland body of water connected with the Taihu Lake.
Last year at the Fifth World Water Congress held in Beijing, the city's Lihu Lake treatment project won the Award for Excellent Water Treatment in China. Wuxi started a comprehensive treatment project on heavy pollution in the Lihu Lake in 2002, after the lake had been frequently attacked by blue-green algae since the 1980s.
The first step was to isolate the Lihu Lake from the Taihu Lake and neighboring rivers with gates and dams. A pump station was also built on an island near the estuary to ensure the necessary dynamic water change between the lakes. Then, about 2.34 million cubic meters of silt and sullage were removed from the lake through environmentally friendly dredging using advanced global positioning systems. Fishing was stopped, and enterprises and residential houses were relocated to restore the natural status of the lake.
Most importantly, the experts suggested rebuilding the biological system in the lake by growing water plants, such as water lilies and reeds, and introduce more aquatic life that could absorb the eutrophic substance or nutrients from the lake.
The above measures have greatly improved the water environment and help rebuild its reputation as a natural tourist resort. Today, the coverage of water plants in the lake have increased to 30 percent. And the real estate value surrounding the lake has also appreciated by almost 10 times. However, water treatment is a considerably long and tough job.
Lihu Lake is still in its initial stage of improvement. More funds and technologies are needed to help sustain its future.
China Daily
(China Daily 07/04/2007 page19)
