Environment / Remediation / Waste

Onslow Landfill Closure works and rehabilitation

Shire of Ashburton

The Onslow Landfill is being decommissioned and remediated in preparation for the development of the Onslow Ring Road.

EWebsiteOnslow LandfillExp

Fast Facts

Location: Onslow, WA

Start: August 2015

Completion: December 2015

Peak Workforce: 30

Ertech’s scope of works included:

  • Excavation of approximately 25,500m3 of waste and 13,200m3 of natural materials
  • Transportation and disposal of excavated waste and natural materials to designated locations on site
  • Excavation and placement of stockpiled materials as restorations soils on top of the capping layer
  • Re-profiling the existing landfill slopes to gradients of 1V:5H (sides) and 1V:20H (top)
  • Installation of a capping system comprising a 300mm sand layer, geosynthetic clay liner, geonet, 1200mm restoration soils and jute layer
  • Construction of a surface water management system comprising drains and a lagoon
  • Installation of a passive landfill gas management system
  • Construction of an access road and security fencing

Work was carried out under the strict supervision of DER appointed Environmental Supervisors due to the site’s sensitive environmental factors, which included asbestos and potential biomedical/clinical waste. A full time on-site CQA Consultant oversaw the stringent quality aspect of the GCL lining works.