Mangrove Mountain Landfill Capping

Unicivil, led remediation and upgrade works at Mangrove Mountain landfill for NSW Public Works and the NSW Department of Primary Industries. The project included constructing a new access road, a perimeter cut-off wall, and a capping layer for the waste cell.

With stringent biosecurity measures and tight tolerances, logistics, public interaction, environmental management, and safety were carefully coordinated.

A 5-metre-deep leachate barrier system lined with geosynthetic clay required innovative installation methods to ensure worker safety.

Capping works featured a gas extraction system, filtration layers, geogrid reinforcement, and a geosynthetic clay liner to prevent water ingress.

The final structure, with compacted clay layers meeting strict permeability standards, safeguards groundwater. Collected water drains to a leachate sump linked to the newly upgraded pump station for off-site disposal.