Kaybob Region – Abandonment and Flare Pit Remediation

Previous investigations, including a Phase II/III ESA and Tier 2 evaluation, identified petroleum hydrocarbon (PHC) impacts confined to deep subsoil within the former flare pit. Groundwater and nearby surface water were not impacted, and risk to receptors was considered low.

The remaining challenges included:

• A defined deep subsoil source area within the flare pit
• Existing flare stack infrastructure acting as a physical constraint
• The need to align abandonment, investigation, and remediation to support efficient site closure

Alta Tech integrated abandonment, investigation, and remediation into a single execution program.

Work included:

• Review of previous ESA work, conceptual site model (CSM), and Tier 2 evaluation
• Nitrogen purging and isolation of process lines between the knockout tank and flare system to enable safe decommissioning
• Coordination and supervision of flare stack removal
• Excavation and profiling of the former flare pit to delineate impacts
• Confirmatory soil sampling and laboratory analysis for PHCs, assessed against Alberta Tier 1 and Tier 2 guidelines for coarse-grained soils and a domestic use aquifer
• Implementation of ex situ chemical oxidation to treat impacted subsoil

Hydrogeologic conditions and receptor pathways were reviewed throughout to confirm risk and guide decision making.

A targeted and risk-based remediation approach addressed residual impacts while avoiding unnecessary excavation.

• Chemical oxidation treatment reduced contaminant mass in deep subsoil
• Removal of flare infrastructure eliminated site constraints and enabled full access to source areas
• Integrated execution improved efficiency across abandonment and remediation activities
• Follow-up confirmatory sampling supports continued progress toward regulatory closure and reclamation

The program established a technically defensible and efficient path forward for final site closure.