Remediation Works at a Decommissioned Colliery

Remediation Works at a Decommissioned Colliery

We were engaged to undertake remediation works at a decommissioned colliery in the Illawarra. Recent investigations revealed that parts of the existing protective capping layer had degraded, exposing hazardous materials like asbestos, heavy metals, and oil-contaminated soil.

Our team had to clear overgrown vegetation, lay down a geotextile marker layer and jute mesh, and cover the area with 1,200 tonnes of Virgin Excavated Natural Material (VENM) clay and 200 tonnes of topsoil. The finished capping layer was revegetated with a mix of native shrubs and plants and fenced off with 200 metres of chain link fencing.

While clearing the vegetation, our team discovered a significant watercourse running through the proposed capping area. This posed a risk of future erosion, which would eventually break down the capping layer and spread contaminated water downstream. To address this, our team provided a drainage solution with the installation of stormwater pipe, headwalls and rip-rap, to divert the water under the capping layer, preventing erosion and ensuring the longevity of the reconstructed cap.


  • Cleared overgrown vegetation
  • Covered the area with VENM clay and topsoil
  • Revegetated the capping layer with a mix of native shrubs and plants

12 Months
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