HANCHENG, Shaanxi -- A chemical spill has left one person dead and another seriously burnt, and polluted a source of drinking water for 100,000 residents in northwest China's Shaanxi province, a local official said Saturday.

A tank car loaded with 25 tons of liquid caustic soda fell into the upper reaches of the Xuefeng Reservoir in the Hancheng City, Weinan City of Shaanxi due to slippery road caused by rains at about 9 p.m. on Friday, said Duan Xuanmin, director of the Hancheng Environment Protection Bureau.

One person in the car was killed on the spot and another was seriously burnt, Duan said.

Local government has built a dam at the site where the car fell, about 5 km away from the reservoir, which is the source of drinking water for about 100,000 local residents, Duan said.

Meanwhile, the government has transported 10 tons of hydrochloric acid from the provincial capital of Xi'an to neutralize the water contaminated by liquid caustic soda, he said.

So far, a small amount of pollutants has flown into the reservoir, but that is not enough to constitute a threat to the water quality, which is now being closely watched by technical workers, the official said.

Local government has ordered departments concerned, such as environmental protection, health, and water resources, to monitor the water quality of the riverway at several sites and report the result every hour, he said.

In addition, the government has issued an urgent notice to the residents along the river, reminding them about the chemical spill and not to use the water.

A spare well has been put into use to provide drinking water at intervals for about 100,000 residents, and so far, the water supply have not been affected much, Duan said.