Panel Report

10.1 The Cigar Lake Mine Site

The intent of decommissioning activities is to dismantle mine infrastructure and make the sites safe. The objective of reclamation activities is to return a site to a productivity level equal to or better than that which existed before mining activities.

The mining regulations administered by both federal and provincial governments require that a site-specific conceptual decommissioning plan be submitted, reviewed and approved prior to the issuance of an approval to operate a mine. Mining companies are encouraged to conduct decommissioning and reclamation activities as soon as possible after an area is removed from production. This allows the conceptual decommissioning plan and the associated financial surety to be updated continually to reflect existing conditions.

At the end of mining, the operator must submit, for review and approval, a detailed final decommissioning plan based on existing mine conditions and the best technology available at the time. Once decommissioning and reclamation work have been completed, the site must be monitored for a number of years, the length of time being dictated by the stability of the site and the levels of any contaminants being discharged into the receiving environment. After monitoring has confirmed that decommissioning has been successful, the proponent is released from further obligations and the Province accepts responsibility for the site.

At the Cigar Lake mine site, the majority of the underground openings would be backfilled with waste or cement as mining progressed. At the conclusion of mining, all salvageable materials would be removed from the mine, the remaining underground openings would be utilized for the final disposal of contaminated surface materials and the mine shafts would be sealed. Decommissioning, as proposed in the EIS, would include removal of all surface facilities and infrastructure with the possible exception of the permanent camp, the airstrip and the access road to Provincial Road 905. Based on discussions with northern communities at the time of decommissioning, the camp, the airstrip and the access road might be sold to interested parties to develop some type of commercial venture or community facility.

Reclamation, conducted on all areas that had been subject to surface disturbance, would include a gamma scan to ensure that radioactivity had returned to original background levels. The land would then be appropriately contoured and revegetated.

Certain features of the Cigar Lake proposal suggest that decommissioning of the mine site to a near "zero footprint" legacy should be possible: the milling of the ore would be at a location remote from the mine site; some of the waste would be placed in mined-out drifts underground; and custom-designed waste rock management strategies have been proposed. Therefore, no significant environmental concern should remain at the site after decommissioning and reclamation. All activities during operation should be planned and implemented in a manner that supports the overall objective of reducing or eliminating the size and duration of the footprint of mining at the Cigar Lake site.

During public hearings, northern residents indicated a desire for consultation on the conceptual and final decommissioning plans. It is important that local people be involved because it is they who must live with the decommissioned site in their backyard. Their involvement should include input into the proposed decommissioning plans and active participation in reclamation and postdecommissioning monitoring activities. The Environmental Quality Committees, now established in northern Saskatchewan, provide an ideal vehicle through which local people can be consulted on decommissioning issues, activities and monitoring.

10.2 The JEB Tailings Management Facility

If the JEB TMF is approved for disposal of mill tailings, the proponents propose to decommission it by covering the tailings with a cap consisting of about 20 m of sand, waste rock and till. [The Midwest Project Environmental Impact Statement, Tailings Management - Additional Information, Cogema Resources Inc., April, 1997, pp. 13-1 to 13-6.] The purposes of the cap would be to prevent plants, animals, birds and people from accidentally coming in direct contact with tailings, and to drain groundwater away from the pit.

Once the tailings reach a predetermined level, they would be covered by two metres of sand. The water cover would then be reduced to about 1 m and, during the following winter, 2 m of clean waste rock would be placed on the ice. When the ice melts during the subsequent summer, a leachate collection system would be installed to dewater the sand layer.

Temperature and pressure transducers would be installed in the tailings and, when instrumentation has indicated that all of the ice has melted, the remainder of the pit would be filled with sufficient waste rock to create a mound over the pit. It is anticipated that the weight of this mound would cause approximately 14 m of settling due to consolidation of the tailings. This consolidation process would expel porewater into the sand layer where it would be recovered by the leachate collection system and sent to the water treatment plant.

During the consolidation stage, occasional recontouring of the mound would be necessary to maintain a well-drained surface. When consolidation is complete, a final cover of till would be placed to bring the top of the mound above the artesian water level in that area. The mound would then be graded and revegetated.

Do you have some examples of other mine sites that have used the solid cap and was it effective?

G. Ross, Mayor of Pinehouse, Transcript of Supplementary Public Hearings for Midwest and Cigar Lake, La Ronge, Saskatchewan, August 26, 1997, p. 153.

During hearings, members of the public questioned the ability of Cogema to place waste rock on top of a pit filled with semi-solid tailings. In particular, it was suggested that, over time, the rock cover might sink into the pit and the tailings, instead of consolidating, might ooze up over the edges of the pit. When asked directly for examples of other places where this approach had been successfully applied, the company's reply was evasive.

In our opinion, the method proposed for decommissioning the JEB TMF is conceptually acceptable. Theoretical indications are that capping of the pit in the manner proposed would provide for the greatest environmental security in the long term. However, experimental verification of the effectiveness of the proposed approach should be sought before deposition begins. Experiments designed to test the response of aged paste tailings to pressure should, therefore, be undertaken. If the application of pressure causes them to flow rather than to consolidate, a more acceptable method for decommissioning the pit should be developed. Unless experimental evidence indicates that it can be successfully decommissioned, the JEB pit should not be licensed as a tailings management facility.

10.3 Financial Guarantees

Both the federal and provincial governments have introduced legislation and/or regulations requiring mining companies to provide financial guarantees, prior to mine start-up, that will be available to cover the full cost of all decommissioning activities. The financial guarantee is intended to ensure that uranium mine and mill sites can and will be decommissioned at no cost to tax payers. The amount of the financial guarantee required by government is based on the requirements outlined in the conceptual decommissioning plan. The plan is subject to regular review to ensure that it reflects existing site conditions.

10.4 Uranium Mining Contingency Fund

The financial guarantees outlined in Section 10.3 would cover monitoring and mitigation costs for, at most, a few decades after mining ceases. However, tailings areas have the potential to pose a threat to the receiving environment for centuries. Uranium mill tailings, in particular, require that containment facilities function efficiently for a very long time.

Decommissioned tailings management facilities would be required to contain contaminants for millennia, during which time many aspects of both the bio-physical and institutional environments will change. Some mechanism must be established to provide for regular investigation of the integrity of contaminant containment and the performance of mitigative measures, should they be required, in the period after institutional responsibility for the area has been transferred from the mining company back to the Province.

For this reason, the panel's report on the McArthur River Project [D.G. Lee, J.F. Archibald, and R. Neal, McArthur River Uranium Mine Project, Supply and Services Canada, 1997, p. 48.] recommended that a fund be established to provide for monitoring and any mitigation required after the responsibility for the sites is returned to Province. The Province of Saskatchewan, in its response stated:

Recognizing its responsibility for long-term management of the site, the Province is investigating options, including a contingency fund as proposed by the Panel, for implementation of monitoring and the funding of possible mitigation, should it be required. [The Government's Position on Proposed Uranium Mining Developments in Northern Saskatchewan, McArthur River Project, Government of Saskatchewan, May 1997, p. 21.]

It is recommended that Saskatchewan move as expeditiously as possible to implement this recommendation.

The value of the contingency fund should be sufficiently large to cover the full costs of the long-term monitoring and maintenance of tailings management facilities and the potential implementation of mitigative measures. Rather than establishing such a fund for each mine independently, there may be merit in considering the establishment of an industry-wide fund which could be called the Uranium Mining Contingency Fund. Such a fund could provide better overall fiscal protection to future generations and cost less to establish than individual funds for each site. There should also be a single authority to oversee the management of the fund and the maintenance, monitoring and mitigation activities, at all decommissioned uranium mine sites in Saskatchewan.

10.5 Conclusions and Recommendations

Decommissioning, since it will take place in the future, is only described conceptually at this stage; the scrutiny and acceptance of specific details must be entrusted to the regulatory agencies. These agencies should ensure that they receive advice from local residents at each stage, and for all elements, of the decommissioning process. Because of the proximity of the mine site to northern communities, this involvement should extend beyond consultation, to participation in the decommissioning, reclamation and postdecommissioning monitoring activities. The Environmental Quality Committees are appropriate vehicles through which northern community residents could be consulted on decommissioning issues, activities and monitoring.

This project, and in particular the JEB Tailings Management Facility, if it is approved, would require long-term monitoring and possible mitigative activities in the future. Arrangements should be made to guarantee that monitoring and any required mitigation could occur without placing a financial burden on future generations. For this reason, the panel reiterates its recommendation for the establishment of a contingency fund to provide for the ongoing costs of long-term monitoring and mitigation, after the responsibility for the sites is returned to the Province.