Yunnan Shuangjie Environmental Sanitation Service Co., Ltd. According to the National Enterprise Credit Information Publicity System, Chenggong construction waste can be cleaned up at Yunnan Shuangjie Environmental Sanitation Service Company. The company is located in Dounan Jiangyun Hotel Expo Center, Chenggong District, Kunming City, Yunnan Province. Its business scope includes construction waste recycling and cleaning. Chenggong District, affiliated to Kunming City, Yunnan Province, is the seat of the Kunming Municipal Committee of the Communist Party of China and the Kunming Municipal People's Government. It is located on the east bank of Dianchi Lake in Yunnan Province and is an important hub leading to eastern and southern Yunnan.