Opinion | Dongguan authorities admit water from Dongjiang not fit to drink

Dongguan authorities have admitted for the first time that water from the city's section of the Dongjiang, or East River, contains excessive levels of heavy metals and industrial pollutants and is not suitable for drinking for at least six months of the year.

The Dongjiang, one of the world's most polluted rivers, supplies drinking water to Hong Kong and a dozen Pearl River Delta cities including Shenzhen, Guangzhou, Dongguan and Huizhou . The water used by Hong Kong does not come from the Dongguan section but from further upstream.

A study conducted by Dongguan's water resources bureau found that the quality of water in the river had worsened steadily in recent years, with most of the pollutants being heavy metals from untreated sewage discharged directly into the river, The Southern Metropolis News reported.

The authorities said levels of carcinogenic nickel had increased dramatically.

In 2010, Dongguan authorities found that only 54 per cent of 114 water samples taken from the Dongjiang met the mainland's drinking standard.

In May, laboratory tests showed that many water samples from the river contained too much ammonia nitrogen and were not even suitable for industrial use or swimming.