Beyond remediation: Containing, confronting and caring for the Giant Mine Monster

Mine remediation entails long-term risks associated with the containment and monitoring of dangerous materials. To date, research on mine remediation in Canada has focused primarily on technical fixes; little is known about the socio-political and colonial aspects of remediation. Using the Giant Mine in Yellowknife (Northwest Territories, Canada) as a case study, this research investigates the story of the Giant Mine ‘Monster’, how it was defined, how it has changed and how nearby communities will care for the mine in the future. Using a mixed-methods approach, this research combines literature reviews, archival analysis, key informant interviews and participant observation in analyzing the multiple experiences, practices and stories of the Giant Mine Remediation Project. Directed by the frameworks of ecological restoration, Indigenous environmental justice and science and technology studies theories of care, this research reveals that, by focusing on the technical containment of arsenic trioxide pollution, the Giant Mine Remediation Project sidelined community objectives for compensation, independent oversight and a perpetual care plan. However, through the ongoing activism of the Yellowknives Dene First Nations and community allies, the Giant Mine Monster is being creatively reframed as something to care for and live with for generations to come – a responsibility for mining wastes that settlers across Canada have yet to meaningfully reckon with. I argue that the Giant Mine case points to a critical reconceptualization of environmental remediation as an anti-colonial mechanism to (re)structure, or (re)mediate, relationships with both land and people. Without a community objectives based approach to remediation, such projects risk continuing systems of colonization, marginalization and environmental injustice.

Biocement stabilization of an experimental-scale artificial slope and the reformation of iron-rich crusts

Novel biotechnologies are required to remediate iron ore mines and address the increasing number of tailings (mine waste) dam collapses worldwide. In this study, we aimed to accelerate iron reduction and oxidation to stabilize an artificial slope. An open-air bioreactor was inoculated with a mixed consortium of microorganisms capable of reducing iron. Fluid from the bioreactor was allowed to overflow onto the artificial slope. Carbon sources from the bioreactor fluid promoted the growth of a surface biofilm within the artificial slope, which naturally aggregated the crushed grains. The biofilms provided an organic framework for the nucleation of iron oxide minerals. Iron-rich biocements stabilized the artificial slope and were significantly more resistant to physical deformation compared with the control experiment. These biotechnologies highlight the potential to develop strategies for mine remediation and waste stabilization by accelerating the biogeochemical cycling of iron.

Thiocyanate biodegradation: harnessing microbial metabolism for mine remediation

Thiocyanate (SCN–) forms in the reaction between cyanide (CN–) and reduced sulfur species, e.g. in gold ore processing and coal-coking wastewater streams, where it is present at millimolar (mM) concentrations1. Thiocyanate is also present naturally at nM to µM concentrations in uncontaminated aquatic environments2. Although less toxic than its precursor CN–, SCN– can harm plants and animals at higher concentrations3, and thus needs to be removed from wastewater streams prior to disposal or reuse. Fortunately, SCN– can be biodegraded by microorganisms as a supply of reduced sulfur and nitrogen for energy sources, in addition to nutrients for growth4. Research into how we can best harness the ability of microbes to degrade SCN– may offer newer, more cost-effective and environmentally sustainable treatment solutions5. By studying biodegradation pathways of SCN– in laboratory and field treatment bioreactor systems, we can also gain fundamental insights into connections across the natural biogeochemical cycles of carbon, sulfur and nitrogen6.