HANCHENG -- The water source area of Hancheng City in northwest China's Shaanxi Province, which has been under a threat of chemical pollution, is now out of danger.

A local government official said Sunday that the Xuefeng Reservoir at the water source area would resume water supply for the city soon.

Around 9:00 p.m. Friday, a tank truck loaded with 25 tons of liquid caustic soda fell into an upstream river of the reservoir in Hancheng partly due to slippery road caused by rains, the official said.

One person in the truck was killed on the spot, and another was seriously burned.

The local government had a dam built at the site where the truck fell, about five kilometers away from the reservoir, which is the source of drinking water for about 100,000 residents.

Meanwhile, at least 10 tons of acetic acid and hydrochloric acid was transported from the provincial capital of Xi'an to neutralize the caustic soda that remained inside the truck and flew into the river.

According to local environmental protection authorities, the neutralization process will not cause new pollution, and the pH value of the water in the Xuefeng Reservoir is at a normal level.

Ten spare wells have been put into use after the chemical spill to ensure drinking water supply for residents in Hancheng.