(Xinhua)
Updated: 2008-02-27 19:28

QIANJIANG - Algae bloom in some sections of Hanjiang river caused the pollution spill in central China's Hubei Province, which once affected supply of drinking water for over 100,000 residents, according to local authorities on Wednesday.

Five water companies in Qianjiang City resumed water supplies at 9 a.m.Wednesday and another tap water company in Jianli County will resume its water supply on Wednesday afternoon, according to the provincial environment bureau.

The companies have been forced to cut off their supply or use backup water sources when it was suspected that three rivers feeding water to them have been polluted.

The three rivers, namely Xinglong, Tianguan and Dongjing, are all tributaries of the Hanjiang River. Suspicion of pollution arose when it was observed Sunday that the water of the three rivers had a strange color.

Laboratory tests show that the boom of maroon cyclotella is to be blamed for the abnormal color of the water.

Different from the toxic blue-green algae, the maroon cyclotella with a fishy smell, is innocuous and will not affect the drinking water for the residents, said He Shibiao, deputy chief of the provincial environment protection bureau.

Experts attributed the algae bloom to the worst snow disaster in decades in the province. The abrupt rise of temperature after the snow thawed lead to the death and rotting of aquatic species and excess nutrients in the water which produces unpleasant tastes and odors.