BEIJING (AP) – A chemical spill in a northwestern Chinese river has polluted a reservoir serving 100,000 residents, state media reported on Saturday. A tanker truck loaded with 25 tons of liquid caustic soda fell into a river on Friday three miles away from the Xuefeng reservoir in the Shaanxi province city of Hancheng, Xinhua News Agency said. Local government officials built a dam at the site after the vehicle fell in and ordered residents not to use the water from the reservoir, the report said.