According to Mining News Pro - For those who work at a mine site on a day-to-day basis, seeing huge
mountains of organic matter aimed at future site reclamation may be a
common occurrence that doesn’t provoke much thought. But for Lauchlan
Fraser, those mountains represent an unexplored universe ready to be
scrutinized.
For a while now, a question has been roaming the mind of the Biology
professor: “Can soil from an old, large stockpile still retain viable
organics, nutrients and microorganisms for successful site
reclamation?”.
Luckily for Fraser, he and his team at Thompson Rivers University
have just received funding to look for answers to such a question at
some of British Columbia’s mine sites. In the western Canadian province,
operators are required to reclaim disturbed land to a defined condition
upon mine closure.
So far we are focused on stockpiles from New Gold’s New Afton mine. We have also
discussed the possibility of sampling at Teck’s Highland Valley copper mine, and are in
discussions to expand sampling to other mines,” the researcher told MINING.com.
According to Fraser, it is important to look at these soil reserves
because some of them can reach heights of 30 metres and sit untouched
for decades. “I expect height to matter, at least to a certain degree. I
wonder, though, whether there is a threshold height, after which there
is little change,” he said.
By analyzing the age and depth of the stockpiles and running DNA
sequencing tests on the soil samples they collect, the researchers also
want to see if there are any variations in the microbial communities
that are key for the restoration of the ecosystems in exhausted mine sites. They
anticipate that older, deeper piles will show a reduction in the
abundance and diversity of such microbial aggregations.
If this is the case, then Fraser and his team would test a second
hypothesis: Is it possible to rejuvenate stockpiled soil at the time of
site reclamation? “Perhaps we need to add specific microbes, or another
soil amendment such as biosolids, ash or wood chips to encourage
microbial development,” he said.
Fraser’s project involves five more people, among them post-doctoral
fellows and master students, and it is expected to last for at least
five years. Both the federal government and local non-profit Geoscience
BC are funding it.