30 years ago, 1,600 hectares (3,953.6 acres) of farmland in Gifu Prefecture, Japan, was contaminated with cadmium.  The cadmium came from a mine.

What happened was that the mine was dumping cadmium into the river, the local farms used the river for irrigation.  The contamination caused a debilitating condition among local residents, called “itai-itai disease“.

A ceremony was held in Toyama City, on March 17, 2012, to mark to end of 30 years of replacing the contaminated soil!  It is considered the biggest restoration project for farm land in history!