Environmental authorities said they will not allow new factories to set up shop near Taihu Lake if there is a chance those factories could further pollute the algae-plagued body of water.

Taihu Lake, which is located in Wuxi, east China's Jiangsu Province, has been hit by an algae bloom that has contaminated the drinking water of two million people.

Chemical factories in the Taihu Lake basin that release excessive amounts of pollution will be closed down immediately, and even those that meet emissions standards will be told to limit their waste discharge in accordance with the lake's capacity to absorb it, said Zhang Lijun, deputy director of the State Environmental Protection Administration (SEPA) yesterday.

The SEPA is also planning to apply the rehabilitation program currently in place for the Songhua River basin to the heavily polluted Taihu Lake basin.

The program includes banning small and heavy-polluting chemical firms and clamping down on unchecked waste discharges.

"Measures and experiences drawn from the Songhua River program will be applied to Taihu Lake," said Zhang, adding that the program is to be expanded to other major polluted water basins in coming years.

Zhang said at a press conference yesterday that the bloom of blue-green algae in Taihu Lake was caused by both natural factors and serious man-made pollution.

Initial investigations showed that the water level of Taihu Lake has plunged to its lowest point in 50 years this summer due to high temperatures and a lack of rainfall.

The situation has allowed excess amounts of the nutrients the algae feed off of to spread in the water.

By last year, industrial pollution and household sewage had boosted the amount of nitrogen in the lake to three times what it was in 1996. Phosphate-based pollutants increased by 1.5 times during the period.

The presence of algae in Taihu Lake resulted in the suspension of tap water supplies to two million people in Wuxi.

Wuxi, an economically dynamic city that administers six districts in the city proper and two other small cities on the outskirts, has a population of 4.57 million. Of that, about 2.32 million people live in city districts.

Eighty percent of the people affected by the suspension of water supplies live in the city districts, according to the local government.

To reduce the bloom, the SEPA, in cooperation with local environment authorities, has been diverting water from the Yangtze River to dilute the lake.

(China Daily June 6, 2007)