About 50, 000 people had their tap water cut off due to a water pollution incident in the Qianzhangyan Reservoir in Wushan County, in southwest China's Chongqing Municipality. Water in the reservoir was polluted by untreated waste water discharged by a sulfur concentrate washery in neighboring Hubei Province last week. Following 11 hours of purification treatment, local government announced that water in the reservoir is clear again. [Photo/Xinhua]