Summary The EPA (as it was then known, now the Department of Environment and Climate Change (DECC)) issued a Remediation Order to PCCS on 1 July 2003. The Remediation Order declared the site, in part, as a ‘remediation site’ and in doing so determined the site represented a Significant Risk of Harm (‘SRoH’), as defined in the Contaminated Land Management Act 1997.
The Remediation Order effectively required the preparation of a Remedial Action Plan (‘RAP’) that addressed the SRoH issues and the implementation of the remediation measures identified in the RAP.
The Remediation Order required the engagement of a site auditor accredited under the Contaminated Land Management Act. In response to the RO, Dr Bill Ryall (Accreditation No.9809) employed by ENSR Australia Pty Ltd (HLA ENSR) was engaged as the site auditor. In August 2008, Dr Bill Ryall withdrew from being an Auditor and Graeme Nyland (Accreditation No. 9808) of Environ was then appointed to fulfill this role.
The two main areas of concern for the DECC consist of the migration of air borne dust containing lead and the migration of lead, zinc, cadmium and manganese from the site via the surface water and groundwater. Remedial Action Plan (RAP) The RAP addresses the significant risk of harm issues, based on the current industrial site usage, as required in the DECC’s Remediation Order.
The purpose of the RAP is to document the possible extent of contamination on-site relative to SRoH, address these contamination issues and provide recommended remedial actions so that the site no longer represents a SRoH and is suitable for ongoing industrial land use. As part of the generation of the RAP, all available historical information and contamination data was examined. In addition 16 on-site groundwater wells were installed during October 2003 and a comprehensive analysis program implemented.
The review of data revealed the major pathways contributing to SRoH at the site, in its current non-operational state, are:
• Surface water overflows from dam systems, generally only associated with significant rainfall;
• Dust from the northern waste disposal areas (known as the slag stockpiles); and
• Groundwater migration. Note that soil contamination is not considered a SRoH issue based on the current site usage however, contamination of the soil will be addressed in the development of the total site remediation strategy.
Slag Mound Covering The closure of the on-site operations and the implementation of short term dust mitigation measures have yielded a 72-95% reduction in ambient lead in air measured by the high volume samplers located in the community surrounding the site.
The covering of the ISF slag stockpiles with an industrial grade plastic liner to eliminate air borne dust which may contribute to elevated lead in air readings in the neighbouring suburbs was completed in May 2004.
A program to cover the slurry stockpiles with industrial grade plastic and associated drainage system was completed in December 2004 by GCE. Documentation certifying the covering of the mounds in accordance with the requirements of the License was prepared by GCE (product & installation) and Umwelt (stormwater drainage system) was provided to DECC.
Return to Home