In eastern China, Lake Tai (Tai Hu) has become almost surrounded by urban development in recent decades. Three cities — Huzhou, Suzhou, and Wuxi — have grown dramatically since 1985, their collective populations increasing from 1.7 million to more than 12.5 million. In 2007, the Chinese government pledged more than $14 billion to clean up Lake Tai, which had been contaminated for years by improper disposal of chemicals and sewage.