Well firstly China's a big place especially out West around Urumqi, and secondly they don't want you to know about it.
A couple of years back there was a news report of 1000 dead pigs in the river that supplied Shanghai with its water, but I posted to prevent loss of face that it was more than likely 10,000, multiply by 10, in fact it was 16,000 and that was probably a lie too.