The Huai River in China has been found "unfit for human contact" at half of its checkpoints as a result of directly dumping effluent and industrial waste into the river. That sounds horrible, but look at the how many people depend on its water:
The rivers posed a "threat to the water safety of one sixth of theIt's not that the water is unfit to drink. It's unfit to have any contact with. The groundwater to 300 meters is also contaminated. Read more in China Rivers Threaten Sixth of Population.
country's 1.3 billion population", the China Daily said.