Excerpt from 3-page article:

BEIJING (Caixin Online) — One crack in a wall is all it would take for a dark gray oval that sits across 11 square kilometers of land to create a massive disaster.

Situated just to the west of Baotou, a city in the resource-rich region of Inner Mongolia, the mine dump for Baotou Iron and Steel Group (Baosteel) (CN:600019) is enclosed by a concrete wall that stands 20 meters high. It is one of China’s largest tailings pools, and contains roughly 180 million tons of metal waste powder.

Until recently, few outside the city knew about the mine dump, which was created 60 years ago. The mine has gained attention on reports that the hazardous slurry contains large amounts of rare earths and other minerals, estimated by some to have a total value as high as 80 trillion yuan ($12.8 trillion) (US:USDCNY).

But the dump has attracted its share of negative news as well. At least 4,000 hectares of farmland have already been contaminated by seepage. Over 130 hectares of farmland are unable to support crops or have extremely low output.

A number of villagers living nearby have also cited several health problems which they attribute to poor controls on the hazardous waste.

[Page 2] … Dalahai Village is 1.5 kilometers to the west of the Baosteel tailings pool. According to data from the Baotou Environmental Monitoring Station for the years 1995, 2000 and 2006, the sulfate, chloride and fluoride content of well water in the village exceeds national irrigation water quality standards by several dozen times…