Water supplies were turned back on Friday morning two days after they were suspended in a south China county, as local authorities say the heavy metals detected in treated water were within safe limits.

On Tuesday, the Yantan water supply plant in Dahua Yao Autonomous County of southwest China's Guangxi Zhuang Autonomous Region reported excessive lead and other heavy metals along a 100-kilometer stretch of the Hongshui River. Water was turned off early Wednesday to the county of 150,000 residents.

A second water sample on Thursday showed the level of lead at 0.056 milligrams per liter, slightly higher than the country's potable water source standard of 0.05 milligrams per liter.

"The heavy metals contained in the river, including lead, chrome, arsenic and zinc, won't endanger people's health after it is treated by water plants," said Zhong Bing, vice head of Guangxi Bureau of Environmental Protection.

The Yantan water supply plant was authorized to resume operation on Friday morning.

The lead and other heavy metals may be caused by illegal discharge of waste water from some smelters on the river's upper reaches, Zhong said.

On June 2, last year, a large section of the Beipan River, a tributary on the upper reaches of the Hongshui River, was contaminated when a power plant in the neighboring Guizhou Province released 300,000 cubic meters sludge. The pollutants affected the Hongshui River, depriving 150,000 dwellers of drinking water for six days.

(Xinhua News Agency April 6, 2007)