The recent contamination of tap water in Lanzhou, the capital of Gansu province, has exposed weaknesses in the city's management, especially its failure to supervise Lanzhou Veolia Water Co, the main supplier of water to the city, according to a city government spokesperson.
On Friday, authorities found levels of benzene, a chemical used in making plastics and which is known to cause cancer, that far exceeded national safety limits in the tap water of two districts in Lanzhou. Authorities turned off the supply of water to one district and warned residents not to drink the tap water for the next 24 hours. The contamination affected more than 2 million residents.
The water supply was resumed in all of the city's districts on Monday after test results showed that the level of benzene was below the national limit of 10 micrograms per liter.
On Tuesday, Wang Ning, spokesman for the Lanzhou city government, said at a news conference that the incident exposed the city's failure to adequately manage Lanzhou Veolia, a joint venture established in 2007 that supplies water to 2.4 million people in four districts of downtown Lanzhou.
The city has a total population of more than 3.6 million.
Wang said at the conference that the city government will regularly test for benzene in the tap water "in accordance with the industry structure of the city". Veolia will also brief local residents on the quality of its water on a monthly basis.
Zheng Zhiqiang, deputy head of a government team tasked with investigating the incident, told China National Radio that the team will look into whether the company delayed its reporting of the contamination.
Zheng said the team found that the company detected levels of benzene in the tap water as early as April 2, although the level of benzene was only slightly above the national limit.
Veolia Water Co said on Monday that the company's detection of benzene in the tap water on April 10 was "pure coincidence" because benzene is an item that the company only tests for every six months.
The company said it was testing the tap water quality in Lanzhou as part of a project with the Ministry of Housing and Urban-Rural Development when it detected the contamination.
The city government has begun a project to retrofit the concrete duct between Veolia's water stations with iron pipelines. The project is expected to be completed in three months.
But the authority's actions have failed to comfort many local residents. On Monday, the Lanzhou Intermediate People's Court rejected a lawsuit filed by five city residents who sought civil damages, a public apology and data from water quality tests over the past year from Lanzhou Veolia.
The court said on its official micro blog that it rejected the lawsuits based on Chinese law. According to China's Civil Procedure Law, the only parties that can file lawsuits are government agencies and related organizations.
Wu Tianying, a lawyer who lives in the city's Chengguan district, said he has filed a lawsuit against Lanzhou Veolia at the court in Lanzhou's Xigu district. Wu demanded data from water quality tests over the past year, a health examination for him and his family members and compensation of 1 yuan (16 US cents).
Xue Chaohua in Lanzhou contributed to this story.