Sansha City in Hainan province is celebrating the fourth anniversary of its establishment on Sunday. It's the country's largest city in terms of gross area including territorial sea, and infrastructure construction has been ongoing since its establishment in 2012.

A sewage disposal system and a garbage sorting facility have been recently commissioned on the city's largest island, Yongxing. Through 9,000 meters of newly-built or renovated pipelines, all the waste water on the island can be collected into this sewage disposal system.

After procedures such as sedimentation and sterilization, the disposed water can then be used for irrigation and construction purposes. Nearly all the city's rubbish can be processed through the garbage sorting facility. A desalination plant is also under construction and is expected to be put into use at the end of August.