To protect the public drinking water source against pollution, more than 60 mine processing plants, 2800 mines, private open mill and mines in Miyun county, Beijing have been shut down since the early 1990s.

Despite the prohibition of government, there are local residents illegally mine iron ore using the rented mining equipment. The basic reason lies in the huge profits. The traditional local livelihood of local residents is plant chestnut with around RMB 6,000 net income a year. However, the illegal miner can make that money in one day. They would be lucky if successfully dig out iron, and if not, they can still make a little fortune by selling gravel.

The illegal mining can not only bring a lot of inconvenience but also pose potential threats to nearby residents. The road has been full of bumps and hollows and the large bare rocks of debris slope are formed after mining. Many villagers are more concerned with the possibility of landslide, mud flow in the future raining seasons.