Landfill Gas Assessment – Works Approval Upgrades at a Former Landfill Facility
Enpoint was commissioned to complete a Landfill Gas (LFG) Assessment at a former putrescible landfill facility currently operating as a Waste Transfer Station, which holds an operating licence under the Environmental Protection Act.
The Client submitted a Works Approval application to the Department of Environment Regulation (DER) to upgrade the waste transfer facility at the site in accordance with their plans for development of its waste strategy. As part of the Works Approval, the DER requested that a landfill gas assessment be undertaken given that the proposed upgrade works overlay landfilled material.
Based on previous investigations conducted at the site and reports submitted to the DER, the site was classified as “possibly contaminated – investigation required” in accordance with Western Australia’s Contaminated Sites Act 2003 (the Act).
Enpoint undertook a landfill gas assessment in order to satisfy the Works Approval Conditions imposed by the DER. The landfill gas assessment was designed to determine the following:
- If landfill gas was being generated in the area of the upgrade works at the site
- If sealed areas proposed as part of the upgrade works at the site may cause any landfill gas that has the potential to pose risk to migrate laterally
- The potential gas-related risk to the proposed buildings
- If any gas mitigation measures are required to be incorporated in the proposed buildings and/or hardstand areas, based on the identified gas risk
The landfill gas assessment involved the installation of eight landfill gas monitoring wells in the area of the upgrade works and completion of six monitoring events at these wells over a three month period. A report was then prepared documenting the outcomes of the landfill gas assessment and submitted to the DER for their consideration in satisfying the Works Approval Conditions.
The landfill gas assessment identified that the building proposed to be constructed as part of the upgrade works require gas protection measures to be incorporated into their design to mitigate potential landfill gas ingress into these buildings. The design requirements were incorporated into Enpoint’s report documenting the landfill gas assessment which was submitted to the DER. The DER subsequently approved the upgrade works subject to implementation of the measures outlined in our report.