Cape Lambert Landfill Relocation
Location:
Cape Lambert
Value:
$30.3 million
Client:
Hammersley Iron
Capabilities:
Remediation, Resources
Contract Type:
Lump Sum and Schedule of Rates
Start Date:
April 2011
Duration:
April 2011 to March 2012
Garlanja, a joint venture between Hicks Civil & Mining Pty Ltd, Thiess Pty Ltd & Thiess Services Pty Ltd, was awarded a contract as part of the Rio Tinto Cape Lambert Port B – Phase A Expansion Project in the Pilbara Region of Western Australia.
To facilitate construction of the stockyards for the new port facility, Garlanja were contracted to relocate the existing Cape Lambert landfill to a new landfill at Cape Lambert.
The project includes excavation, sorting, stockpiling, classification and testing of approximately 250,000 cu.m of waste from the existing landfill which was established in the 1970’s as part of the original Cape Lambert Port.
To ensure any contaminated materials were handled without risk, ongoing monitoring and sampling of ground water, dust, fibrous building materials, hydrocarbons, gases and heavy metal contamination was undertaken throughout the excavation process. The landfill contained iron ore, fibrous building materials, heavy metals, concrete, general waste and scrap steel.
Once sorted, tested and classified, the waste is hauled in road trains via a public road to the new 7kP landfill site. The new landfill is predominantly class I and contains an HDPE lined class II cell. Upon completion, the landfill will be encapsulated with over 48,000 cu.m of clean material including a 1m thick topsoil cap, rendering it inert. The works also include security fencing, access road construction & future cell preparation.
All machines are fitted with HEPA filters for potentially working in asbestos contaminated soil and work practices modified daily to provide a safe workplace for all involved.
A first for treatment of contaminated material
Upon excavation and classification of highly contaminated class III & class IV materials at the existing landfill, Garlanja, in consultation with the client, SKM and the Western Australia Department of Environment and Conservation (DEC) proposed a method to chemically treat the class IV contaminated soils on site to reduce their classification to a lower class and enabling the re-classified material to be relocated to the new 7kP cell. The method involves chemical immobilisation and stabilisation of heavy metals contained within the soil.
These works are the first of their kind in the Pilbara region with only a handful of projects where this has been undertaken in the Perth Metropolitan area.
The proposal and approval by the WA DEC for treatment of the class IV material enabled Garlanja to eliminate hauling over 20,000 tonnes of contaminated waste over 1,600km to Perth for disposal at specified landfills. This technology, along with significant savings to the client and the environment has set the precedent as to how contaminated waste will be managed in the future in the Pilbara.
