Beijing has an administrative area of 16800 square kilometer with 62% of mountainous area and 38% of plain area. The registered population was 11.70 million in 1995, among them are 6.5 million urban dwellers; besides, there are 3 million floating population. The solid waste in Beijing can be classified into industrial solid waste (waste residue), which account for 71.86% of the total; and domestic solid waste, which account for 28.14%. Domestic solid waste is also called domestic garbage, and garbage for short.