Beijing has completed a survey of around 55,000 companies and other organizations emitting pollutants into the air and water and producing solid waste, the municipal environmental authority said on Wednesday.

Some 54,970 units including companies and institutes have been identified during the one-year census, of which businesses such as restaurants and vehicle repair shops accounted for the majority, around 36,885, said Zhao Zhiwei, deputy head of the Beijing Environmental Monitoring Bureau on Wednesday.

Sources related to the manufacture of chemical products, steel and vehicles followed with around 16,511 units identified. The third major pollution source was agriculture and poultry breeding, at around 1,574 units, he said.

More than 27,000 companies in 20 major polluting industries have been listed for priority monitoring, which will see records closely supervised, Yao said.

According to the municipal environmental supervision bureau, Beijing imposed penalties on 1,773 companies in the first seven months of the year, with fines exceeding 78.3 million yuan ($12.3 million), and increase of 86.8 percent on the same period last year.