Arsenic and old nails

Students from the Rural International Student Exchange program at Tsinghua University are helping villagers in Shanxi province purify drinking water. Zhang Zefeng reports.

Even in his childhood, Liang Honggang had the impression the water quality in his village was poor. However, he didn't fully realize how bad it was until he attended high school in the nearby city of Pingyao and had access to tap water.

"The water just tastes different," says Liang, now a 23-year-old graduate of Taiyuan University of Technology. "Back home, the water is smelly, especially during summer."