Water Stewardship Information Sources

Citation Royal Military College and University of British Columbia. 2010. An environmental investigation of the Quinsam watershed. Prepared for the Canadian Water Network.
Organization Canadian Water Network
URL http://www.coalwatch.ca/sites/default/files/Environmental-Investigation-of-the-Quinsam-Watershed_Cullen-and-Lai_April2010.pdf
Abstract/Description or Keywords An environmental investigation of the Quinsam watershed, located on Vancouver
Island, British Columbia was directed by Dr. William R. Cullen.
This study was initiated to investigate whether the mine was introducing arsenic
into the watershed and if so, what the effects of arsenic input were on biota in the
watershed. To determine natural and anthropogenic elemental loadings in sediments in
the area, sediments were collected from a number of background lakes and lakes on the
mine property, including the lake of highest concern, Long Lake. These results were
compared with waste material from the mine site. The uptake of arsenic was investigated
by using mussels in both short and long-term monitoring studies. A short-term caged
mussel experiment was designed to investigate the potential for arsenic uptake, while
long-term monitoring of mussels downriver of the mine was used to investigate current
and historical arsenic loading in mussels.
Anthropogenic inputs of elements, including arsenic, to the watershed were
identified after collected lake sediments were analyzed. In particular, Long Lake
sediments were found to be elevated in arsenic. Further speciation analysis and
bioaccessibility, or solubility, testing indicated that the introduced arsenic contamination
can be easily solubilized and is more soluble than arsenic in the waste rock from the mine
site. These speciation and bioaccessibility tests indicate that Long Lake sediments have
forms and solubilities of arsenic similar to those from surrounding lakes. Further study is
required to identify which of many potential sources around Long Lake is responsible for
the elevated arsenic concentrations. The lake that flows into Long Lake, No Name Lake,
was previously identified as also having elevated arsenic concentrations (Nordin, 2006)
and the current study obtained similar results.
Elevated arsenic concentrations in sediments were found to correlate with
elevated arsenic concentrations in biota. During the short-term caged mussels experiment
higher arsenic loadings were found in mussels in Long Lake than in surrounding
Quinsam watershed lakes. Higher loadings were seen in mussels collected from the
Quinsam River in relation to the same species of mussel monitored in a nearby
watershed, Simms Creek.
Arsenic concentrations are elevated in Long Lake as a result of acid rock drainage
and other chemical process associated with mine waste. The high arsenic levels are
associated with high concentrations of sulphate. The arsenic is available to bivalves, and
presumably other biota. Further studies to identify the points of arsenic input should be
undertaken to allow for corrective action. In particular sediment cores would provide
evidence of the extent of anthropogenic arsenic inputs since the mine opening.
Information Type report
Regional Watershed Vancouver Island North
Sub-watershed if known Quinsam River
Aquifer #
Comments
Project status complete
Contact Name
Contact Email