Staff members of China Railway Xiongan Construction Co., Ltd. clear up wastes for a pond at Yipuxi village of Xiongzhou town in Xiongan New Area, north China's Hebei Province, Aug. 14, 2019. Xiongan New Area started the work to clean up all its polluted ponds in 2018. By now, over 800 polluted ponds have been finished in stages of refuse disposal, wastewater filtration and comprehensive environmental improvement. The main work now has turned to the ecological restoration to those treated ponds, which is expected to be finished by end of 2019. (Xinhua/Xing Guangli)

Photo taken on Aug. 14, 2019 shows a pond after pollution treatment at Mazhuang village of Zhugezhuang Township in Xiongan New Area, north China's Hebei Province. Xiongan New Area started the work to clean up all its polluted ponds in 2018.(Xinhua/Xing Guangli)

Aerial photo shows a pond after pollution treatment at Yipuxi village of Xiongzhou town in Xiongan New Area, north China's Hebei Province, Aug. 14, 2019. Xiongan New Area started the work to clean up all its polluted ponds in 2018. By now, over 800 polluted ponds have been finished in stages of refuse disposal, wastewater filtration and comprehensive environmental improvement. The main work now has turned to the ecological restoration to those treated ponds, which is expected to be finished by end of 2019. (Xinhua/Xing Guangli)

In this aerial photo, staff members of China Railway Xiongan Construction Co., Ltd. clear up wastes of a pond at Yipuxi village of Xiongzhou town in Xiongan New Area, north China's Hebei Province, Aug. 14, 2019. Xiongan New Area started the work to clean up all its polluted ponds in 2018. By now, over 800 polluted ponds have been finished in stages of refuse disposal, wastewater filtration and comprehensive environmental improvement. The main work now has turned to the ecological restoration to those treated ponds, which is expected to be finished by end of 2019. (Xinhua/Xing Guangli)