River pollution culprit remains a mystery

Illegal waste dumping has been blamed for a tap water scare in the eastern city of Jingjiang early last month, but who did it remains a mystery.

Tests conducted by Jiangsu Province's environmental protection authority showed the pollutant causing foul-smelling river water was ethyl disulfide, a chemical compound used in the production of pesticide.

However, pinpointing the source is difficult as there are a number of plants in the China Fine Chemical Park in Taixing, a city upstream of Jingjiang, producing ethyl disulfide and several built along the Yangtze River, yesterday's Legal Weekly reported.

The Jinjiang water authority detected the foul smell in the river on May 9. The city government quickly shut off tap water supplies to almost 700,000 residents, causing a rush for bottled water.

Tap water supplies resumed two days later after samples were found to meet national drinking water standards.

In a report issued on June 3, Cheng Wei, a section chief of Jiangsu's environmental protection department, pinpointed illegal dumping as the cause but he couldn't confirm whether an individual or a plant was the source.

Just four days after tap water supplies resumed in Jingjiang, the canal in another upstream city, Taizhou, was giving off a foul smell.

The local environmental protection bureau offered a reward of 100,000 yuan (US$16,000) for anyone who had any information about the pollution.

On May 27, the local Binjiang Industrial Park identified the pollutant as ethyl disulfide but said none of its plants was at fault. There have been no further developements since then.

In recent years, polluted water has become a major issue along the Yangtze.

Nearly a third of cities on the Chinese mainland are situated along the river. But there are also almost 10,000 chemical plants — half of China's total — posing potential health risks to nearly 400 million people, the newspaper said.

In 2010, the Yangtze River Water Source Protection Bureau said nearly 33.9 billion tons of waste was discharged into the river that year, mostly from smaller cities.