Tailings Management Plan – Water-capping – Directive 085
In April 2016, Suncor Energy Inc. (“Suncor”) filed an application (the “TMP Application”) requesting that the AER approve its proposed tailing management plan for new and legacy fluid tailings associated with the Suncor base plant (the “Proposed TMP”). Suncor also filed a concurrent related application requesting amendments to previous approvals affected by Suncor’s Proposed TMP (the “Amendment Application”).
The Amendment Application described the construction, operation, and reclamation and closure modifications to Suncor’s mine, tailings, dedicated disposal areas, and reclamation and closure plans.
The AER denied both the TMP Application and the associated Amendment Application (the “Applications”) on the basis that the Proposed TMP did not satisfy the requirements of the Lower Athabasca Region: Tailings Management Framework for the Mineable Athabasca Oil Sands (the “Lower Athabasca TM Framework”) or Directive 085: Fluid Tailings Management for Oil Sands Mining Projects (“Directive 085”).
Water-capping
The AER noted that Directive 085 requires a TMP to describe the risks, benefits, and trade-offs associated with tailings treatment technologies; and to describe the environmental risks and how they will be managed during operation, reclamation, and closure.
The AER found that the Proposed TMP did not provide adequate information regarding environmental effects and mitigations measures during operation, reclamation, and closure stages. The AER found that the Proposed TMP provided high-level information on the benefits and trade-offs of its technologies, but water-capping was not included in the comparison.
The AER found that Suncor provided insufficient information to allow the AER to conclude that the water-capping technology – a new and unproven technology – will result in an aquatic ecosystem in the time predicted. Therefore, the AER held that the Proposed TMP did not meet the requirements of Directive 085.
Alternatives
The AER noted that both the Lower Athabasca TM Framework and Directive 085 require a tailings management plan to consider alternatives where water-capped fluid tailings technologies are proposed, given that water-capping is considered an unproven technology.
The Proposed TMP recommended that the decision to employ water capping or solid capping be made in 2039, 6 years after the expected life of the mine.
The AER found that the Proposed TMP did not provide adequate information on how the in-pit terrestrial landform would be constructed.
The AER noted that timelines for reclamation of the terrestrial option are 150 years or more. The AER found that this would be delayed by a 2039 decision milestone, and is significantly longer than the 30 year timeline associated with the proposed use of water-capping technology.
Deficient RTR Performance Criteria
Directive 085 requires a TMP to include ready-to-reclaim (“RTR”) criteria to track the performance of the treated fluid tailings during depositing operations to ensure that the deposit can be reclaimed as predicted. RTR criteria must address a deposit’s physical properties and environmental effects. Tailings deposits with higher uncertainty or more complexity may require more criteria.
The AER found that the Suncor failed to establish that its RTR criteria would ensure that lands affected by deposits can be reclaimed as predicted. The AER also found that Suncor failed to provide RTR criteria addressing potential effects the deposits may have on the environment or future reclamation.
Insufficient Information
The AER found that Suncor did not provide adequate information as follows:
(a) Plans to reduce uncertainties with:
(i) the deposits, the types of mitigation proposed and associated challenges for their implementation, or the triggers for initiating their implementation; and
(ii) the duration to operate pollution prevention and mitigation measures and the consideration of this duration in the environmental risk and trade-offs assessment; and
(b) Evidence to demonstrate assurance of progressive reclamation of tailings ponds as shown in the progressive reclamation status maps.
Decision and Direction
The AER denied the Applications, without prejudice to future Suncor applications. The AER directed Suncor to file a new fluid tailings management plan application and any additional amendment applications required to support changes to the approved project.
