From the article :The most infamous mine in China is Bayan-Obo,...

From the article :The most infamous mine in China is Bayan-Obo, the largest REE mine in the world. Even more infamous than the mine itself is the tailing pond it has produced: there are over 70,000 tons of radioactive thorium stored in the area. This has become a larger issue recently because the tailing pond lacks proper lining. As a result, its contents have been seeping into groundwater and will eventually hit the Yellow River, a key source of drinking water. Currently, the sludge is moving at a pace of 20-30 meters per year, a dangerously rapid rate.

70kt of thorium does sound like a lot,might have meant thorium contaminated, either way I wouldn't like to live there......or downstream.
kcf