SHIJIAZHUANG, Nov. 22 (Xinhua) -- Each morning, 48-year-old Wang Huiyi joins his fellow cyclists on a bike ride around a local lake, which was once a sinkhole filled with industrial wastewater.
South Lake in Tangshan, north China's Hebei Province, used to be a place that locals would avoid getting close to as it was swarmed with flies and mosquitos, and waste used to pile tens of meters high.
