Alberta-Pacific Forest Industries, Boyle, Alberta

The Alberta-Pacific Landfill (site) is a pulp mill landfill accepting fly ash, grate ash, reject lime, dregs/grits, alum sludge and biosolids wastes from the on-Site pulp plant. XCG undertook the detailed design for the new engineered landfill expansion in 2019 in anticipation of construction in 2020.

The project included a conceptual landfill plan design brief and a staged detailed design of a new engineered landfill expansion including design drawings, specifications, and a construction quality assurance and quality control (QA/QC) plan. Additional work including a review of potential options to expand the existing cell using a berm extension, and a slope stability assessment for the waste material.

The conceptual landfill plan design brief covered site operational issues including fencing, stockpiling, material management (overburden and topsoil), on-site borrow pit; sloping requirements, volume and site life, and filling and covering strategy. The conceptual landfill plan design brief also included plans to address haul and access road requirements, leachate management, surface water management, base grades, composite liner, future expansion, and final cover. The conceptual landfill plan design brief formed a basis for the detailed design of the landfill expansion.

The detailed design was completed up to and including the 100% (Issued for Regulatory Review) design. 50% and 90% conference call design meetings were held to review relevant design issues and to allow Alberta-Pacific to provide input on the design. The design included a composite landfill liner system, leachate collection system and piping, surface water management, and perimeter berms and roads. The composite landfill liner system composed a compacted clay liner and a HDPE geomembrane. Drainage on top of the liner was provided using drainage stone on the landfill base and a geocomposite drainage layer on the landfill side slopes.

The following deliverables were completed for the project:

• Conceptual Landfill Plan Design Brief;

• Cell 2B Berm Extension Letter;

• Waste Slope Stability Assessment Letter;

• 50%, 90%, and 100% completed drawings package including:

- Complete drawing list;

- Existing site plan;

- Plan of proposed works;

- Sections; and

- Details.

• Construction QA/QC Plan; and

• 90%, and 100% completed design specifications.