A cofferdam of Dushan flood control works is breached to discharge water of Taihu lake in Wuxi, east China's Jiangsu Province, June 1, 2007. Breaches were made on some cofferdams of China's third-largest Taihu lake to sluice water polluted by an blue-green algae bloom. Water authorities had also diverted the Yangtze River to dilute the lake water.(Xinhua Photo)

    BEIJING, June 5 (Xinhua) -- China's main environmental protection body has vowed to close all factories that are discharging pollutants into the Taihu Lake, which has been hit by an algae bloom contaminating the drinking water of two million people.

    The bloom of blue-green algae in the east China lake was caused by natural factors and serious man-made pollution, said Zhang Lijun, deputy director of the State Environmental Protection Administration (SEPA), on Tuesday.

    He told a press conference that the content of nitrogen in the lake in 2006 tripled that in 1996, while the content of phosphate pollutants had increased by 150 percent.

    The SEPA would investigate all the enterprises releasing nitrogen and phosphate pollutants in the area. Those exceeding emission standards would be shut down, and production restrictions would be imposed on the rest according to the lake's water quality.

    The SEPA has ordered the government of Jiangsu Province to ban the construction of new factories discharging nitrogen and phosphate pollutants, Zhang said.

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

    Workers have collected 6,000 tons of algae from the lake, according to an environmental protection official of Wuxi.

    "The city is facing more risks of blue-green algae bloom in the future. Local governments should make an emergency response plan to deal with the outbreak," said Zhang.

    According to the SEPA, surface water suffered from "medium" pollution overall across China in 2006. Forty percent of the 745 monitoring sections under the national environmental monitoring program were relatively good.

    The Taihu, Dianchi and Chaohu lakes, and Liaohe and Haihe rivers suffered from serious pollution in 2006. The Songhuajiang, Yellow and Huaihe rivers had medium contamination.

    Zhang blamed industrial and household sewage and the excessive use of fertilizers as the major sources of the pollutants in water.

    He said the government would implement stricter pollutant discharge standards for industries, and upgrade sewage treatment facilities and control the use of chemical fertilizers.

    "The safety of drinking water is our priority in environmental protection," Zhang added.

A cofferdam of Dushan flood control works is breached to discharge water of Taihu lake in Wuxi, east China's Jiangsu Province, June 1, 2007. Breaches were made on some cofferdams of China's third-largest Taihu lake to sluice water polluted by an blue-green algae bloom. Water authorities had also diverted the Yangtze River to dilute the lake water.(Xinhua Photo) Photo Gallery>>>