There is a really good Chinese language article on pollution of Lhasa River and problems associated with mining at Gyama village of Meldro Gungkar county by Woser, the premier Tibetan blogger. You can read an English translation of the article by High Peaks Pure Earth. Check out the striking photographic evidences of the problems with water pollution and mining in the region.
The Gyama mine is now owned by a Canadian company named Jinshan. I have written about human rights implications and Canada's involvement in these projects. See: Canada and Crime Against the Tibetan People