Environmental Investigations Overview
The Deed Administrators and Fitzwalter Group have been working with various environmental consultants to complete extensive site characterisation investigations. These investigations were in addition to those required by the DEC as a result of the obligations arising out of the Remediation Order
The investigations included a comprehensive soil testing procedure, surface water and ground water analysis and the identification of contamination management options. The results of the various site assessments and investigations were used to inform the development of the overall site remediation strategy – the Remediation Project
Remediation Order
Background
The NSW DEC issued a Remediation Order to PCCS on 1 July 2003. The Remediation Order required the preparation of a Remedial Action Plan ('RAP') (Provide as internal link to ‘Remedial Action Plan (RAP)’ that addressed the serious risk of health (SRoH) issues and the implementation of the remediation measures identified in the RAP supported by a properly accredited site auditor.
The two main areas of SRoH concern for the DEC consist of the migration of air borne dust containing lead and the migration of lead and other known metals from the site via the surface water and groundwater.
Remedial Action Plan (RAP)
The RAP addresses issues and documents possible causes of the SRoH and provides recommended remedial actions so that the site 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.
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 remediation project.
Slag Mound Covering
The closure of the on-site operations and the implementation of dust mitigation measures have yielded up to a 90% reduction in ambient lead in the 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 airbourne dust which may contribute to elevated lead in air readings in the neighbouring suburbs was completed in May 2004. The slurry stockpiles were also covered with industrial grade plastic together with an associated drainage system which was completed in December 2004. Documentation certifying the covering of the mounds in accordance with the requirements of the License was prepared and delivered to the DEC. Representatives from the DEC’s Newcastle office also inspected the mounds following completion.
Surface water and Groundwater
Post closure measures have been taken to minimise runoff from the site. The existing dam systems are being upgraded to be more effective in capturing the surface run-off during rainfall events. The Effluent Treatment Plant ('ETP c') located on-site continues to be used to treat water from these dams before discharging treated water off-site in accordance with an EPA licence.
Further surface water flow investigations continue and regular monitoring of Cockle Creek water quality is demonstrating that the on-site control measures are proving effective.
Investigations relating to the characterisation and modelling of groundwater passing under the site is complete.
PCCS plans to install a number of systems to collect and treat the groundwater before it leaves the site. Subject to authority approval, these systems will be installed in early 2007 and monitored to demonstrate their efficiency.
Monitoring results
Since the closure of the site in September 2003 lead in air and metal concentrations in water have fallen dramatically to be around 90 percent below the levels pre-September 2003.
Pasminco continues to monitor the Lead-in-Air in the community surrounding the PCCS site. Instruments are used which act like vacuum cleaners, pulling a known volume of air across a filter. The particles in the air are filtered out, collected, weighed and then analysed for lead.
There are 8 monitoring sites placed at locations around the site. Different locations were sampled at different times, but monitoring occurred 24 hours a day, 7 days a week. Some locations were monitored every day while others produced a single daily sample every 6 days.
The lead in air results since the closure of the smelter in September 2003 have decreased dramatically as are shown in the graph below.
Remediation Project
PCCS has been undertaking various actions to clean up the site in response to the Remediation Order including dust control, removal of materials from the site for reuse, demolition of the plant and environmental management of surface and groundwater.
Furthermore, PCCS has been investigating the best means to remediate the site. After considering a range of options and having sought appropriate technical advice and the views of government on the regulations the most appropriate remediation methodology for the site’s slag materials and contaminated soils has been determined to be containing them in a cell on the site.
Preliminary concept design studies have been completed which determined the engineering and environmental requirements for the construction of the containment cell as the central component of the proposed on-site remediation strategy.
A formal submission to the Minister for Planning under Part 3A of the Environmental Planning and Assessment Act 1979 to obtain approval for the remediation project was made in July 2006. The submission outlined the proposed remediation strategy for the PCCS site.
The application seeks to obtain approval from the Minister for Planning for works including:
- the staged remediation of PCCS owned lands at Boolaroo;
- the acceptance onto the Main Site of certain specified waste materials from nominated residential properties in Boolaroo, Speers Point and Argenton (and possibly from the Incitec-Pivot site at Boolaroo);
- the construction of a containment cell (or two cells) on the Main Site for the receipt and long term storage of materials arising from the sources noted above; and
- associated environmental controls and site management during and after remediation.
As the various site areas are remediated, they will become available for development for the future uses of industrial, commercial, residential or open space. Residential uses will not be permitted on the cell. Approvals for the redevelopment phases will be sought independently.
Further information on the remediation project can be found in the Community Report August 2006 and Community Report December 2005 including details of the proposed location of the cell on the site and the preliminary remediation staging plan.
A copy of the Environmental Assessment Report prepared in support of the Remediation Project can be downloaded here [document missing].
Environmental Assessment Report [document missing]
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