I've done some research for a friend who considered sending her son to a school in Tseung Kwan O. Yes, TKO is cheap because it has 3 huge, and still expanding landfills (2 of them were full and closed). You can find the detail info on landfills in HK in the govt site at:
There are a total of 3 phases of landfills in TKO. In year 2004, the HK govt announced that the landfill in TKO will be expanded by 15,000 cubic metres, to lengthen its usage by 12 more years.
In Nov 19, 2004, a research done by a professor of the Chinese University of HK (Dr. Yu of the Faculty of Medicine – Family Medicine) was reported in a Chinese newspaper. The title of the news was "The air quality in Tseung Kwan O is carcinogenic". Dr. Yu analysed 16 organic pollutants in the air samples from the landfill areas of Tseung Kwan O, and 2 other places. The result is that the possibility of getting cancer in Tseung Kwn O is 86.3 person per 1 million. The 2 other landfills have the figures of 75.1 and 104.95. (This news report is in Chinese. If you want to read the original text, drop me your email address and I’ll email it to you.)
Jockey Club and the govt have put in a lot of money to construct very nice playgrounds and grasslands (as park) just above 2 of the landfills already full and closed. But the toxic gases from decomposition will sip through the ground over time.... It depends on how lucky to you are in bumping into those toxic gases.