(Xinhua)
Updated: 2008-02-27 22:04

QIANJIANG - Water supplies resumed on Wednesday to almost 200,000 people along the three tributaries of Hanjiang river affected by an algae bloom, local authorities of central China's Hubei Province said.

The algae bloom had turned the water red since Sunday, forcing authorities to cut supplies to nearby residents and eight schools.

Five water companies in Qianjiang City resumed supplies at 9:00 a.m. and another company in Jianli County resumed supply at 5:00 p.m., according to the provincial environment bureau.

"Laboratory tests show that a bloom of maroon cyclotella has been identified as the cause of the abnormal water color," said He Shibiao, vice director of Hubei Provincial Environmental Protection Bureau.

Unlike the toxic blue or green algae, maroon cyclotella has a fishy smell, is innocuous and will not affect drinking water, He said.

Tests on the water from Jianli and Qianjiang sections of Hanjiang river showed the amount of cyclotella reached 100 million parts per liter, ten times the amount that could cause algae bloom.

Experts attributed the bloom to the worst snow in decades in the province. The abrupt rise in temperatures after the snow thawed killed a large amount of aquatic life which decayed and lead to excess nutrients, producing an unpleasant taste and odor.

The Xinglong, Tianguan and Dongjing rivers are all tributaries of the Hanjiang River. Pollution was suspected as the cause when it was reported on Sunday that the water had turned a strange color.

Water companies were forced to cut supplies and use contingency sources.