Giant Mine Oversight Board Strategic Research Plan Development

Lefebvre, René ORCID: https://orcid.org/0000-0002-7938-9930 (2023). Giant Mine Oversight Board Strategic Research Plan Development Rapport de recherche (R2176). INRS Centre Eau Terre Environnement, Québec. (Soumis)

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Résumé

The Giant Mine is located just north of Yellowknife in the Northwest Territories, and it produced gold from 1948 to 1999. Ore processing generated arsenic trioxide dust, of which 237,00 tonnes were collected and stored underground at the mine site in “chambers” built for that purpose as well as in open mine “stopes”. The Proponents of the Giant Mine Remediation Project are the Governments of Canada and of the Northwest Territories. The “Frozen Block”, involving freezing outside and within the dust storage chambers and stopes, was selected as the arsenic trioxide dust remediation alternative to be implemented. The Environmental Assessment judged appropriate the remediation alternative, but it was considered an interim solution for a maximum of 100 years and required its periodic review every 20 years. The Giant Mine Oversight Board (GMOB) was established as an independent entity to ensure the responsible management of the remediation of the Giant Mine site and to manage a research program to seek a permanent solution to the arsenic trioxide dust. This document was produced to guide GMOB in the development of a formal research strategy. Section 1 of this report describes the context and purpose of the research strategy, which is to provide GMOB with a rational framework to carry out its mandate to manage a research program to seek a permanent solution to the arsenic trioxide dust at the Giant Mine site. Section 2 provides an overview of the characteristics and storage of arsenic trioxide dust at the Giant Mine site. The process followed for the selection and implementation of a remediation alternative is described because it provides an analog for the process of developing a permanent solution. This process also involved the definition of criteria for the selection of a remediation alternative that could also be relevant regarding a permanent solution (Table 2.2). Furthermore, the conditions under which the arsenic trioxide dust is found after the implementation of the Frozen Block remediation alternative must be considered for the implementation of a permanent solution. Section 3 provides a vision of the desired nature of a permanent solution for the remediation of arsenic trioxide dust. As the remediation alternative, the permanent solution would have to minimize the risk of long-term arsenic release, but its nature should not require monitoring and maintenance, so that it would have a “perpetual” nature. The Environmental Assessment indicates that it would be the responsibility of the Proponents of the Remediation Project to design and implement a permanent solution. Section 3 also describes the components of a permanent solution that would involve 1) the removal of dust from the underground mine, and 2) the stabilization of the dust in a form that prevents arsenic leaching, so that 3) storage of the stabilized dust would require no, or minimal, monitoring and maintenance. The development of a permanent solution must thus consider each of the components, which present specific constraints and challenges requiring scientific and technical developments (Table 3.1). Finally, based on the historical timelines of the Giant Mine Remediation Project, potential timelines are established for the processes related to the search for and the implementation of a permanent remediation solution for arsenic trioxide dust (Table 3.2). Section 4 briefly describes the previous studies and the current research activities supported by GMOB. Research activities and studies were first carried out for the selection and design of an arsenic trioxide dust remediation alternative and these studies covered a wide range of topics. However, most of these studies were carried out 20 years ago. Recently, GMOB thus sponsored a State of Knowledge (SOK) Review “to provide an assessment of technologies, methods, or integrated combinations of technologies and methods that are potentially relevant to arsenic trioxide management” (Table 4.1). One of the findings is that advances in hydraulic borehole mining imply “that dust extraction could be performed effectively and safely” at the Giant Mine site. Finally, the top-ranked dust stabilization and processing method was Vitrification, and it was recommended to devote further research to vitrification-based technologies. GMOB is currently supporting seven (7) studies through the TERRE-NET research network (Table 4.2). Their emphasis is on the development of a better fundamental understanding of the nature of arsenic trioxide dust and on potential methods to achieve its passivation by transforming the dust into another form. One of these studies notably looked at the leaching behavior of vitrified Giant Mine dust using a commercial process. This is a key study to further assess the potential of vitrification for the transformation of arsenic trioxide dust. These studies should be completed in 2023. Section 5 specifically describes the potential content of the GMOB Strategic Research Plan, which aims to define 1) the role of GMOB in the development of a permanent solution for the arsenic trioxide dust present at the Giant Mine site, 2) the strategic actions that will structure the development of a permanent solution that would meet the hopes of the community, 3) the topics to be covered by the studies sponsored by the Research Program and their priorities, and 4) the process that will be followed to carry out the Research Program and the criteria that will be used to measure the progress made. The report outlines the issues needing to be addressed regarding roles of GMOB and the Proponents, the permanent solution development process, the criteria to be used to assess a potential permanent solution, and the timeline to develop and implement a solution. An initial step would thus require GMOB to seek an agreement with the Proponents regarding these issues. In priority, it would also be important to take actions ensuring the full involvement of the community in the development of an acceptable permanent solution. Another step would be to secure adequate funding for the Research Program. Whatever the level of financial resources available to carry out the Research Program, GMOB could strive to leverage its research spendings by supporting proposals to research granting organizations. GMOB could also adopt a long-term continuous research approach to ensure coherent development of the components of a permanent solution. This “continuity” could be achieved by the support of a research chair at a local education institution. GMOB could also ensure the development of local “capacity” and the training of Highly Qualified Personnel from NWT. Section 5 provides indicators that could be used to measure progress regarding the orientation of the Strategic Research Plan (Table 5.1). The priority of research topics previously identified is also provided to guide the allocation of funds. Finally, potential initial steps for the development of a Research Strategy are provided at the end of Section 5.

Type de document:	Rapport
Mots-clés libres:	arsenic trioxide dust; remediation of mine site; research program; permanent solution; remediation alternative; arsenic release; vitrification-based technologies
Centre:	Centre Eau Terre Environnement
Date de dépôt:	26 mai 2025 19:17
Dernière modification:	26 mai 2025 19:17
URI:	https://espace.inrs.ca/id/eprint/16421

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