From the Economist:
Malaysia banned sand exports as long ago as 1997. Indonesia followed suit in 2007 on environmental and, some say, political grounds. Ever since, it has become harder for Singapore to secure supplies for its booming construction industry and sea-fill plans.
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So Singaporean contractors turned to Cambodia, where prices are low and environmental standards almost non-existent. But this May Hun Sen, Cambodia’s prime minister, outlawed exports of sand. Again, environmental pressures were cited, but there may also have been a political motive.
After the Cambodian ban Vietnam’s sand exports surged, achieving volumes seven times as big as last year, with Singapore the main customer. Then last month Vietnam’s construction ministry called for a temporary halt to the trade, to assess its impact on the environment and the local building industry. NGOs in Thailand and Bangladesh have also pressed their governments to reject recent requests to allow sales of sand to Singapore.