Lao Dams, Mining Ruining Sekong Water Quality in Cambodia

Now, dredging for gold on the river’s tributaries in southern Laos’s Attapeu and Sekong provinces has become a bigger issue than the muddiness caused by dam construction, he said. 

“The main problem now is the dredging of the Xekaman and Xesou Rivers in Attapeu province and the Sekong River in Sekong province for gold by Vietnamese companies and Lao companies working with Vietnamese companies.” 

The companies use back hoes to scoop up soil from streams and riverbanks, then extract the gold onsite using chemicals, which likely include mercury, he said. 

“This obviously causes a lot of turbidity downstream,” he said, referring to a measure of how much particulate is suspended in the water.

Previously, dredging had been done by Chinese-owned boats in the Sekong River, but now the heavy machinery used by Vietnamese companies is causing more sediment to flow downstream. 

Chemicals such as mercury are often used in the mining process to get gold out of rock, and residents in southern Laos have complained of toxic pollution from gold mining along the Sekong waters for years.
http://www.rfa.org/english/news/laos/sekong-06252013190742.html