PFAS Landfill Cells to support West Gate Tunnel Project

In early 2020, Symal joined forces with the Hi-Quality Group to craft a specialized facility tailored for the receipt, storage, testing, and sorting of PFAS materials from the West Gate Tunnel Project (WGTP). This collaboration aimed to address the significant volume of excavated material, estimated at around three million tonnes, slated for transportation to this facility. Hi-Quality had originally earmarked the proposed PFAS sorting area on their site for future industrial redevelopment and enlisted Symal through early contractor involvement to helm the design and construction process.

The project involved the construction of a bespoke PFAS facility within the existing landfill, featuring 58-68 storage cells covering an estimated total area of 275,000m², along with three pre-treatment ponds designed to capture site runoff. Also, the project entailed the development of specific access and haul roads spanning approximately 65,000m².

With a construction duration slated for six months, the project called for substantial earthwork totaling 220,000m³, in addition to 320,000m² each of lining materials and pavement. Notably, the project also involved the installation of 7,000 meters of slip-formed barrier and the creation of three large lined retention basins.

Symal's collaborative approach with the client and project consultants facilitated the exploration of various pavement designs and costing options, leading to the adoption of cost-effective solutions during the early contractor involvement phase. Symal actively engaged in providing multiple program options, including acceleration strategies, which bolstered confidence and flexibility in delivering the purpose-built PFAS EcoHub.

Addressing the potential permeability of PFAS materials, extensive pavement and cell formations were implemented to mitigate seepage within the site.

Drawing upon their experience and network of specialised subcontractors, Symal evaluated cost-effective solutions to enhance pavement strength while minimising permeability. The incorporation of foam bitumen stabilisation emerged as a superior alternative, offering both structural integrity and reduced permeability at a considerable cost-saving advantage.