Tailings Management Plan – Ready-to-Reclaim Criteria – Fluid Tailings Profiles – Water-capping Technology
In this decision, the AER considered Canadian Natural Upgrading Limited’s (“CNUL”) application pursuant to section 13 of the Oil Sands Conservation Act (“OSCA”) for approval of its tailings management plan (“TMP”) for the Jackpine Mine (“JPM”).
For the reasons summarized below, the AER approved CNUL’s application, subject to terms and conditions (the “Approval Conditions”) to address uncertainties and deficiencies, including requiring a new application be submitted by September 30, 2022.
The AER approved CNUL’s TMP for the short term management of fluid tailings, finding that there was sufficient information in the application to demonstrate CNUL’s ability to manage JPM tailings for the next few years.
However, the AER was unable to assess whether CNUL would be able, over the medium- and long-term, to manage its fluid tailings and treated tailings deposits to meet the Lower Athabasca Region: Tailings Management Framework for Mineable Athabasca Oil Sands (“TMF”). objective and Directive 085: Fluid Tailings Management for Oil Sands Mining Projects (“Directive 085”) requirements due to uncertainties and deficiencies in the application, including the following:
(a) CNUL’s TMP was inconsistent with existing approvals;
(b) CNUL’s new and legacy fluid tailings profiles were not aligned with existing approvals, the TMF, or Directive 085;
(c) CNUL’s proposed ready-to-reclaim (“RTR”) criteria, RTR trajectory, and targeted ecosites have a degree of uncertainty over the medium- and long-term; and
(d) the AER had concerns with CNUL’s proposed tailings treatment technology.
The AER required CNUL to submit an amendment application by September 30, 2022, addressing the uncertainties and deficiencies identified in the AER’s decision report.
Original Jackpine Mine Approval
The JPM was approved by a joint Alberta Energy and Utilities Board (“EUB”) and Government of Canada panel in 2004 (“Decision 2004-009”). The JPM started production in August 2010, and tailings placement began in the external tailings facility (“ETF”). An expansion to the JPM was approved by a joint panel established by the Energy Resources Conservation Board and the Government of Canada in 2013 (see: 2013 ABAER 011). The application for the expansion under Environmental Protection and Enhancement Act (“EPEA”) was still under review at the time of this decision. In-pit tailings placement started in Fluid Cell (“FC”) 1 in 2016.
Regulatory Scheme
Tailings are a by-product of the process used to extract bitumen from mined oil sands and consist of water, silt, sand, clay and residual bitumen.
The AER regulates tailings from oil sands mining operations to ensure that the tailings are managed in an efficient, safe, orderly and environmentally responsible manner over their entire life cycle.
The AER applies a risk-based approach to regulating, where higher-risk activities receive the greatest regulatory oversight. Given the nature and scale of fluid tailings generated by oil sands mine operations and the ongoing research and development of tailings treatment technology, fluid tailings management is one of Alberta’s higher-risk industrial activities.
The Government of Alberta regulates tailings under the TMF. The AER noted that following regarding the TMF:
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The TMF’s objective is to minimize fluid tailings accumulation by ensuring that fluid tailings are treated and reclaimed progressively during the life of a project, and all fluid tailings associated with a project are ready-to-reclaim within 10 years of the end of mine life.
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The TMF establishes four outcomes: land use must be returned to Albertans, sustainable ecosystem, liability is minimized to Albertans, and environmental effects are managed.
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As part of the implementation of the TMF, the AER released Directive 085, which sets out requirements for fluid tailings TMPs, including both existing fluid tailings (i.e., legacy) and new fluid tailings.
TMP and Existing Approval Alignment – End of Mine Life and Tailings Solvent Recovery Unit Tailings
The AER found that aspects of the TMP were not aligned with existing approvals:
The AER found that the following information indicated in the TMP was inconsistent with what was proposed in the JPM expansion applications:
(a) the TMP indicated no planned bitumen production expansion, which extended the end of mine life date from 2052 to 2105; and
(b) JPM froth would continue to be transferred to the Muskeg River Mine (“MRM”), and tailings solvent recovery unit (“TSRU”) tailings would continue to be managed at the MRM until JPM’s end of mine life.
Fluid Tailings Profile
The AER found that the new and legacy fluid tailings profiles in CNUL’s application were not aligned with existing approvals, the TMF or Directive 085 over the medium- and long-term, based on the following:
the proposed time to accumulate the peak volume was longer than the duration guided by the TMF and Directive 085, since the end of mine life target was greater than five years of fluid tailings production at JPM;
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the proposed profiles did not demonstrate that fluid tailings treatment capacity was equal to or greater than the new fluid tailings production rate;
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the proposed profiles were premised on an end of mine life of 2115, whereas the current authorized end of mine life was 2052; and
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the proposed profiles did not demonstrate that all legacy fluid tailings would be RTR by the JPM’s end of mine life (2052) and that all new fluid tailings generated at the JPM would be RTR within ten years from JPM’s end of mine life.
Given its finding that new and legacy fluid tailings profiles were aligned only for the short term, the AER approved CNUL’s new and legacy fluid tailings profiles only until 2023. CNUL was required to submit new and legacy fluid tailings profiles in the amendment application.
The AER did not authorize CNUL’s proposed end of mine life of 2115. The AER found that CNUL’s application did not include sufficient information to support the change, such as an updated mine plan and life of mine closure plan.
Thresholds
The volume of accumulated fluid tailings is the primary indicator in the TMF used to manage and decrease liability and environmental risk resulting from the accumulation of fluid tailings. Triggers and a limit (collectively referred to as “thresholds”) are set relative to the fluid tailings profiles. The thresholds ensure that fluid tailings are not accumulating beyond a volume or at a rate that precludes operators from meeting the TMF’s objective. Various management actions are required when thresholds are exceeded.
Three project-specific thresholds are set based on an operator’s fluid tailings profiles in accordance with the TMF and Directive 085:
(a) Profile deviation trigger:
(i) occurs when the volume of fluid tailings is growing 20 percent faster than that approved for the profile;
(ii) additional management action is required when the profile deviation trigger is exceeded;
(iii) is based on when the fluid tailings volume growth is 20 percent higher than that in the approved profile; and
(iv) allows a five-year rolling average to account for year-over-year variability. The profile deviation trigger applies to both legacy fluid tailings and new fluid tailings profiles.
(b) Total volume trigger:
(i) occurs when the volume of fluid tailings has exceeded its approved maximum accumulation and requires additional management action;
(ii) level is based on 100 percent of the greater of the maximum approved fluid tailings volume profile or the end of mine life target (volume of fluid tailings that can achieve RTR state within 10 years after end of mine life and is the equivalent of 5 years, or less, of fluid tailings volume accumulation); and
(iii) applies to the new fluid tailings profile.
(c) Total volume limit:
(i) under the TMF is the volume of fluid tailings above which presents an unacceptable risk to the environment and potential long-term liability;
(ii) up exceedance compromises the ability of an operator to have all of their fluid tailings in an acceptable management state (i.e., RTR) within ten years of the end of mine life. Therefore, the most severe management responses are initiated;
(iii) is based on 140 percent of the greater of the maximum approved fluid tailings volume profile or the end of mine life target; and
(iv) applies to the new fluid tailings profile.
The AER considered that its decision to authorize the new fluid tailings profile only until December 31, 2023, affected the approach to set the total volume trigger and total volume limit. The total volume trigger and limit are based on the greater of the maximum approved fluid tailings volume profile or end of mine life target. As there was no end of mine life target authorized, the AER set the total volume trigger at 26 million cubic metres (Mm3) and the total volume limit at 36 Mm3.
Ready-to-reclaim (RTR) Criteria
Due to the degree of uncertainty in CNUL’s proposed RTR criteria, RTR trajectory and targeted ecosites over the medium- and long-term, the AER required CNUL to address the following deficiencies in the amendment application updated RTR criteria for each type of deposit in the amendment application.
For the mixed deposits formed by thickened tailings, whole tailings, and coarse sand tailings in the ETF (mixed deposits), the AER specified the following RTR criteria: 70 percent solids by weight, based on deposit sampling, within five years of tailings placement and groundwater monitoring in accordance with the EPEA approval.
CNUL cannot remove centrifuge tailings from the fluid tailings inventory until the revised RTR criteria are approved.
Treatment Technology Selection and Performance
CNUL uses thickeners and combines the thickened tailings with whole tailings and coarse sand tailings to form a mixed deposit. CNUL was also using four centrifuge units to treat tailings. The thickener operation began at the JPM start-up in 2010, with the placement of thickened tailings in the ETF’s Dedicated Disposal Area (DDA) 1. Centrifuge tailings treatment technology was commissioned in 2014 with the placement of centrifuge tailings in DDA1.
The AER authorized CNUL to continue to:
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use thickeners and combine the thickened tailings with whole tailings and coarse sand tailings to form a mixed deposit, subject to the approval conditions; and
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operate its four centrifuge units, subject to the approval conditions.
The AER expressed concerns with CNUL’s treatment technologies and the ability of the tailings deposits to support future reclamation activities, achieve stable targeted ecosites and meet the TMF’s outcomes. Therefore, the AER required CNUL to address the following in the amendment application:
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assess the performance and limitations of tailings deposits containing mixed deposits, and monitor quarterly and report annually on the performance of the mixed deposits; and
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assess, describe, and propose the selected treatment technologies that ensure that the treatment capacity is equal to or greater than the production rate of new fluid tailings and that all legacy fluid tailings would be RTR by JPM’s end of mine life.
The AER did not authorize CNUL to use fluid tailings drying or atmospheric fines drying (“AFD”), based on its finding that CNUL’s TMP did not provide sufficient information to evaluate the use of these technologies at the JPM.
With respect to water-capping technology, the AER noted that CNUL was not proposing to have any water-capped pit lakes at the JPM at this time. The AER noted that water-capping technology was subject to further assessment, research and future policy. Therefore, the approval prohibited water-capped pit lakes and requires CNUL to meet future policy on water-capped pit lakes.
Stakeholder and Indigenous Community Engagement
The TMF and Directive 085 describe the importance of transparency, engagement, and enhancing stakeholder and indigenous community understanding of fluid tailings management.
The AER noted that, as part of its original approval decision, the AER’s predecessor commended the original applicant, Shell, for its proactive, inclusive and constructive engagement of genuine-interest stakeholders.
To ensure continued transparency, information sharing and involvement in tailings management, the AER required CNUL to engage stakeholders and indigenous communities on tailings management activities undertaken pursuant to the approval.
The AER also required CNUL to:
(a) hold an annual forum with stakeholders and indigenous communities regarding tailings management activities; and
(b) report to the AER annually on its engagement efforts.
Environmental Effects
For approved projects, the proposed TMP should be consistent with the previously predicted environmental outcomes or identify any inconsistencies. The existing and proposed monitoring plans will confirm that environmental performance is achieved.
No EPEA approval air emission limits were being amended as a result of the TMP.
The AER found that there were no changes arising from the TMP that resulted in changes to previously-assessed impacts to surface water and groundwater quality during the mine’s operating phase. The AER found that CNUL’s existing surface water and groundwater control measures managed the environmental risks and effects during the mine’s operating phase.
