Open valve

Normally in the event of a chemical spill, toxic liquids are directed into an emergency holding pool. But in this case, the pollutants were instead carried through a drainage canal for rainwater and ended up flowing into the river.

Here the details become sketchy, but Xinhua reported that an open valve allowed the liquid to flow into the river. The valve is only supposed to be opened on especially stormy days to allow rainwater to flow out of the plant, but it was open when the leak occurred and the investigation has yet to establish why.

Media criticism has also focused on an expensive monitoring facility that for some reason failed to respond during the spill.

In 2008, the automatic monitoring center, the first in China and costing 850 million yuan, was established in Shanxi. The center, under the direction of the leader of the provincial department of environmental protection, monitors discharges of pollutants from a number of companies, including Tianji Coal Chemical Industry Group and sends real-time reports to the department via wireless Internet.

The provincial administration has yet to respond to the question of why the monitoring system didn't work when the aniline spill occurred.

The website of Tianji Coal Chemical Industry Group claims that the company was commended in 2011 for its achievements in environmental protection, energy conservation and emissions reductions.

However, according to Xinhua, in both 2011 and 2012 the company was investigated and punished by the provincial environment department for the excessive discharge of pollutants and irregular use of monitoring equipment.

Contact the reporters at wuwencong@chinadaily.com.cn and pengyining@chinadaily.com.cn

Tang Yue contributed to this story.