Yukon River Unified Watershed Assessment - Yukon River Inter ...

Yukon River Unified Watershed Assessment
Mining
Mining presents a major
concern throughout the
drainage. Mining has been in
existence within the drainage
since the mid 1800’s. Hard
rock (underground tunnels),
open pit, and placer (surface)
mining present unique
concerns for effluent runoff,
chemical spills and sediment
loading. “…regulations did not
exist until after 100 or more
years of unregulated mining
occurred in Alaska.” Mining
represents a major economic
base in Alaska and Canada.
Old mines present a particular challenge for people responsible for protecting the Yukon’s
environment. It is difficult to determine how the environment has changed when you do not
know what was there in the first place. And when the concern is about pollution in moving
water, the task becomes even more challenging. …But many of the Yukon’s old mines were
established before there was much concern about potential impacts on the environment "It
is very important to have good baseline data because a definition of impact is only as good
as your ability to prove it," says Benoit Godin, head of Environmental Contaminants with
Environment Canada in the Yukon. A 1985 study showed that there were significantly
higher levels of heavy metals in the creek sediments than on other parts of the property.
There were also fewer types of benthic invertebrates in the creek. "Abandoned mines will
continue to haunt us in the Yukon," says Godin. (your Yukon, column #126)
Abandoned and aging mines are a problem throughout the drainage. This problem results
from mines that do not fall into a specific category for clean-up/remediation and there is
technically no responsible party who is required to maintain and reclaim the site. Not only
are the mines themselves a potential risk to the watershed through the breaching of tailing
ponds, but also the machinery and petroleum products, which are left after the mine closes.
Many mining practices were not regulated until the 1970’s in the US. There is a need to
inventory all the mining sites, present and historic to determine the actual remaining areas
of concern and the locations of these sites. Once these sites are inventoried, a priority
ranking could be established for clean-up. However, there is currently no financial support
to clean-up these abandoned mines which were in existence over 100 years ago and which
are still a source of non-point source pollution to the watershed.
Sewage and Landfills
Figure 6 - Mined Watersheds in the Yukon River
Sewage disposal represents a unique challenge in the Yukon Watershed. Most villages within
the Alaska portion of the drainage use sewage lagoons to dispose of and treat raw sewage.
June 2002 Page 13 of 44