Residents of Lanzhou rushed to buy mineral water after the city's water supply was contaminated. 
An oil leak last Thursday caused an increase in the benzene levels in the drinking water of Lanzhou, a city in northwestern China. Since benzene is a toxic and carcinogenic liquid chemical, the city’s residents rushed to local supermarkets to stock up on bottled water, before city officials had a chance to deal with the problem. But many residents feel the authorities failed to warn them of the serious health risks they faced.
Veolia, a French company that co-manages water treatment in Lanzhou along with a Chinese company, detected unusually elevated levels of benzene in the local water at around 5 pm on April 10. Further measurement revealed 118 to 200 micrograms of benzene per litre, whereas the national threshold for safe drinking water is only 10 micrograms.
And yet, the public was only alerted to the hazard at noon the next day when Xinhua, an official press agency, published a statement regarding the spike in benzene levels. The government of Lanzhou issued a public warning around 5 pm on Friday afternoon. It remains unclear whether Veolia or the local government is responsible for the delay in warning residents. An investigation was launched to determine whether Veolia was in any way responsible.
Lanzhou’s stores were ransacked for their bottled water. Long queues formed in front of the stores, as can be seen on photos shared on social media. Likewise, an amateur report of an American English teacher in Lanzhou shows the public’s frenzied reaction.
On Weibo, China’s equivalent of Twitter, one user took it upon himself to perform electrolysis of Lanzhou’s tap water and mineral water. Electrolysis is a process that decomposes and reveals the solids dissolved in water. The results are worrying.
The authorities’ delay in alerting residents has caused a great deal of irritation, and Lanzhou residents have taken to Weibo to express their anger, attacking both Veolia and the local government. Their anger is exacerbated by the fact that a month ago, residents from certain neighbourhoods had complained that their tap water had an unpleasant taste. Moreover, Lanzhou is one of China’s most polluted cities.
"Veolia, apologise and get out of here! Let’s remember that this is not the first time our water has been polluted. Yet there are never any explanations or persons held accountable. We are lied to constantly, and there’s nothing we can do about it! We drank this water at work, children drank it at school, and then only in the evening do we hear that we shouldn’t be drinking tap water? Abroad, such a company would already be out of business, if only because of the fines!”
“These are the demands that every Lanzhou resident should make: 1. Veolia should be kicked out of the water market in Lanzhou; 2. Those responsible for the contamination should be punished; 3. Public officials in charge of water and the environment should be fired; 4. Lanzhou residents should receive compensation, notably by providing water free of charge for the coming years. We’ve been speaking about polluted water since March, but the government accused those who shared this information of spreading rumours. What happened in March needs to be investigated!”

“The authorities tried to hide the seriousness of the situation, which is irresponsible”

Yun (not his real name) is a business manager in Lanzhou.
I learned that the water had been contaminated when it was announced by the city authorities. But I already had my suspicions, because the water had been odd since last month; it had a strange odour that reminded me of antiseptic.
In the first two days following the alert, residents rushed to supermarkets to purchase bottled water. Prices spiked [a small 50 or 55 cl bottle was selling for 3 to 6 yuan, whereas it costs 1 yuan normally], but it has stabilised and it is now possible to buy water bottles at a normal price. At home, we exclusively use bottled water to wash ourselves, cook, and clean our dishes. The government is distributing two bottles of water per resident per day, but it’s not enough to live normally, so we are forced to buy our own.
Many people have been pointing the finger at Veolia, but in my opinion, it’s mostly the local government that is at fault. I think they wanted to hide the seriousness of the situation and so they gave the alert far too late. As a result, pregnant women and old people drank water that is detrimental to their health. It’s an extremely irresponsible attitude. They are now saying that tap water is no longer dangerous, but I don’t really trust them and I prefer to remain cautious.
According to a preliminary investigation by local authorities, the leak is the result of two explosions in 1987 and then 2002 in a factory in Lanzhou belonging to a subsidiary of CNPC, a Chinese oil company. Following these explosions, 34 tonnes of chemical residues were released and then absorbed by the soil, which eventually contaminated underground water resources. The local authorities claim that 800 tonnes of polluted water were pumped after the leak’s detection.
Post written with FRANCE 24 journalists Man Ho Kam (@kam_manho) and Corentin Bainier (@cbainier).