Chinese authorities tried to slow a river hit with a toxic spill by building 51 dams and were trucking polluted water upstream to dump it back into the river to filter it with cotton, straw and activated carbon, state media said yesterday.
The spill of about 60 tonnes of coal tar into the Dasha River in north China's Shanxi Province was the latest in a series of mishaps to degrade the country's already polluted waterways. Officials said there have been at least 76 water pollution accidents in the last six months.
In a separate incident on Thursday, a series of explosions rocked the Longxin Chemical Plant in the city of Longquan, Zhejiang Province, destroying two factories and threatening to contaminate the Oujiang River, which empties into the East China Sea, the official Xinhua news agency reported.
A spring that feeds the Oujiang lies close to the blast site. Large amounts of sand and stones were trucked to the site to stem the intake of the spring in an effort to prevent any waste water from contaminating the river, Xinhua said.
One person was injured and two people, a 38-year-old woman and a 42-year-old man, were reported missing after the blast, it said.
Earlier state media reports claimed the blasts released huge amounts of toxic fumes.
But an official at the Environmental Protection Bureau in Longquan said monitoring had found no serious impact to water or air quality from the disaster.
Like many Chinese bureaucrats, the official refused to give his name. He said he could not provide any further information.
The plant mainly produces hydrogen peroxide -- a chemical commonly used for bleaching, antiseptics and deodorants, the official Xinhua news agency reported late on Thursday. Industrial hydrogen peroxide contains arsenic, heavy metals and other toxic ingredients.
As a precaution, about 800 people were evacuated from the area near the factory, a female official at the Chinese Communist Party publicity office in Longquan said yesterday.
She said firefighters were standing by to help prevent further explosions, but that the blazes set off by the multiple explosions were brought under control on Thursday evening.
Some 4.7 million people live along the Oujiang.
The cause of the explosions was under investigation, the party official said.
In the Dasha River spill, a truck overloaded with 60 tonnes of coal tar -- a substance linked to cancer -- crashed and dumped its contents into the river.
Cleanup crews were scrambling yesterday to absorb the toxic substance before it reaches the Wangkuai Reservoir of Baoding, a city of about 10 million people, Xinhua said.
The pollution was said to be traveling about 1kph downstream toward Baoding, which is about 70km from the site of the accident.
The day after the spill, the pollution had reached Hebei's Fuping County, where some 50,000 residents rely on the river for drinking water. Fuping residents were told to take water from nearby reservoirs and seven standby wells until the river could be cleaned, Xinhua said.
Prolonged exposure to coal tar has been linked to cancer.