The water supply was turned off in one district, and officials
warned citizens not to drink tapwater for the next 24 hours.
"Lanzhou has shut down the contaminated water supply pipe and
deployed activated carbon to absorb the benzene," local authorities
said in a statement.
The water supply company, Lanzhou Veolia Water Co, is majority-owned
by the city government, with Veolia China, a unit of French firm
Veolia Environnement, holding a 45-percent stake.
"Initial investigation showed the high levels of benzene were caused
by industrial contamination at one of the two culverts that transfer
raw water from a sedimentation plant to the water treatment plant,"
Veolia said in a statement.
Authorities said they found 200 micrograms of benzene per liter of
water. The national safety standard is 10 micrograms.
Lanzhou, a heavily industrialized city of 3.6 million people in the
northwestern province of Gansu, ranks among China's most polluted
Preliminary inspection showed the benzene came from chemical plants,
the local government said on its website, although no culprit was
named. The environmental bureau is carrying out further
Operation of the polluted culverts has been suspended, Veolia said.
Lanzhou Veolia Water was working to redirect to its water treatment
plant water which usually goes to a power plant, which should
restore normal supply as soon as possible, Veolia said.
China's official Xinhua news agency said an initial investigation
had found problems in a three-km (two-mile) channel which links a
plant that pre-processes the water and the plant that supplies the
Closure of that channel would halve Lanzhou's water supply, the
report quoted Tian Hong, head of Lanzhou's water quality monitoring
station, as saying.
Fire engines would carry water to affected areas, it added.
[to top of second column]
Pictures circulating widely on Chinese Internet sites showed long
lines at grocery stores where people were loading up on anything
drinkable. Other images showed barren shelves cleared of bottled
"It's not just bottled water that is gone. Even all the beer and
milk has been snatched up," one resident wrote on the Twitter-like
The Yellow River, which runs through Lanzhou, has not been
contaminated, Xinhua said.
Xinhua said it was the second water-related incident in Lanzhou in
as many months.
In March, residents reported a strange odor when they turned on
their taps. It was found to be a high concentration of ammonia, but
was still within national limits.
In 2005, water supplies to the northeastern city of Harbin were cut
off after an explosion at a chemical plant spilled benzene into the
Songhua River, pushing levels to more than 100 times safe limits.
(Reporting by Stian Reklev, Kathy Chen, Ben Blanchard and Michael
Martina in China and Geert De Clercq in Paris; editing by Andrew
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