Contaminated Site Project Profile

Job site/ location: Former James Hardie Manufacturing Plant, Welshpool, WA
Client: Devcon
Value of Works: ~$ 300,000
Commencement of Works: July 2008
Completion of Works: July 2010

Description of Works

Upon decommissioning, the site was classified ‘Possibly Contaminated – Investigation Required’ under the Contaminated Sites Act 2006. A Mandatory Audit Report was required as a regulatory condition on development, and the client required works to be undertaken to amend the classification to ‘Remediated for Restricted Use’. The working site was 10ha in size and was subsequently divided into three stages of environmental investigative works.

Work Undertaken

  • Review and assessment of previous investigations
  • Collection and targeted analysis of >300 in-situ soil samples
  • Collection and analysis of several rounds of groundwater samples from the unconfined aquifer
  • Waste management of 2,000m3 of spoil produced during onsite excavation activities
  • Identification of buried asbestos pipework and other forms of ACM
  • Regular consultation with Auditor and regulatory bodies
  • Compilation of DEC-compliant Preliminary Site Investigation (PSI), Detailed Site Investigation (DSI), Remediation and Validation Plan (RVP) and Site Management Plan (SMP).


The site was further developed by the client during the investigation and remediation process. The works completed on-site by SERS enabled the reclassification of the site for planning purposes from ‘Possibly Contaminated – Investigation Required’ to ‘Remediated for Restricted Use’.

SERS implemented a ‘capping’ strategy, to contain residual asbestos in soil at the site, conservatively saving the client around $10 000 000 in remediation costs and allowing the site to be developed without the need to import and compact material to achieve the desired surface levels for development.

Development at the site is now nearing completion, with the client able to lease out a number of warehouses for industrial purposes.