EJQ4 - Spring 2025 - Journal - Page 52
Managing impacted soil
There are also impacted soils associated with historical mine sites to consider. Typically, heavier molecular contaminants with lower solubility remain after decades of exposure. For smaller volumes of impacted soil, it’s
common to simply dig up the soil and ship it to a licensed waste disposal
facility. However, the scale of impacted soil with historical mine sites requires innovative approaches to make these projects cost-e昀昀ective. This
requires consideration of new technology, technology from other sectors,
or technology that bene昀椀t from economies of scale (i.e., extra space and
longer remedial time periods), such as thermal desorption, soil washing,
solidi昀椀cation/stabilization, landfarming, or ex situ bioremediation (i.e.,
biopiles).
It’s also vital to develop soil management plans to characterize the soil
on site and de昀椀ne di昀昀erent management options depending on the level of contamination and associated risk. Soil that has high concentrations
of contaminants that are not leachable would be managed di昀昀erently
than soil that has high concentrations of contaminants that are leachable.
Having a soil management plan that outlines the types of soil on site and
the management options allows clear direction for construction and op-
erations sta昀昀 and an understanding of the cost to manage the impacted
soil — and having that soil management plan approved by regulators allows operational 昀氀exibility for construction and development of the mine.
Bringing creativity and technology to the forefront
Mining is an important economic driver in Canada and provides the critical minerals essential for the energy transition. The redevelopment of
historical mines requires innovative strategies, emphasizing creative
problem-solving and close collaboration among environmental scientists, engineers, and mine design engineers.
Collaboration and innovation between disciplines needs to occur at the
early planning stages of the mine and must consider every phase of a
mine’s life cycle, including post closure. Through this approach to redevelop historical mines, we can more e昀昀ectively tackle legacy environmental impacts and reduce seepage risks from new mine infrastructure,
ultimately enhancing overall environmental conditions.
Michelle Fraser is a Senior Hydrogeologist and Canadian
Water Resources Technical Discipline Leader at Stantec.
E N V I RON M E N T J OURN A L QUA RT E RLY RE PORT • S PRI N G 2 0 2 5 • P AGE 5 2
