A court rejected a lawsuit against Lanzhou's sole water supplier for delaying reports about severe water pollution.

The Lanzhou Intermediate People's Court in Gansu Province said yesterday that the five residents who filed the lawsuit were not qualified to sue in cases involving harm to the public's interest. Only institutions and organizations have that right, the court said.

The five residents said the Sino-French joint venture, Veolia, had a duty to supply safe water. They also said Veolia let the toxic water flow despite being aware of the contamination. It didn't take any measures until 18 hours later, according to their lawsuit.

The residents demanded an apology be published in a newspaper or on television and compensation of 5,972 yuan (US$961.49) for mental distress and financial losses, Caixin.com reported.

Levels of benzene, a cancer-inducing chemical, in the city's tap water rose 20 times above national safety levels on Friday, forcing the city to turn off supplies and warn residents not to use it for the next 24 hours.

The Lanzhou government said tests on Friday had found 200 micrograms of benzene per liter of water. The national safe standard is 10 micrograms.

Benzene is known to damage human blood cell production.

By yesterday morning, the city's water had been declared safe after tests showed benzene levels met national standards.