As a subsidiary of CNEEC, Beijing Xingqiao International Engineering Technology Co. Ltd undertakes the Princess House sewage disposal project with the disposal capacity of 50000m3/d, including 20000m3/d used water as water resource for river and 30000 m3/d used water for industry and municipal facilities.

Because of the sewage disposal factories in Princess House and Zhanggaiying, the sewage disposal capacity of Hohhot rises from 100,000tons to 210,000tons per day and the sewage disposal rate increase from 42% to more than 85% with an increased COD-reduced capacity of 10,000tons per year.

The successful performance of the sewage disposal factories plays a very important role in the improvement o the water environment of Hohhot.