Beijing Huaifang Reclaimed Water Project is the largest underground reclaimed water plant project in Asia. After completion, the reclaimed water plant can convert 200 million tons of wastewater into usable reclaimed water at full capacity throughout the year. In 100 Kunming Lakes, it is called “Groundwater City” in Beijing. The treatment scale of the water plant is 600,000 tons/day, the reclaimed water treatment system adopts the world's advanced technology, and the effluent water quality meets the national surface water environment IV standard. The reclaimed water is injected into the wetland landscape on the ground and transported to the nearby Xiaolong River, where the beauty of an acre of spring that has disappeared in Beijing for decades has reappeared.