Chao Lake in Anhui province is at risk of another algal bloom caused by pollution, the South China Morning Post reported. The lake was covered by an outbreak of blue-green algae last month, as was Tai Lake in Jiangsu province. Ma Jun, director of the Institute of Public and Environmental Affairs, a non-governmental group in Beijing, said an algae outbreak could occur in Chao Lake at any time. One of the main sources of pollution is the nearby Hefei Industrial Park, one of the country's largest. A Hitachi factory in the park was ordered to stop operations because it was dumping more than 160 tons of acid waste into the lake daily. The Tai Lake algae outbreak last month caused water shortages to more than 2 million people in Wuxi city, sparking public outrage.