Orica has produced several other reports as part of its management and remediation investigation for the Car Park Waste Encapsulation (CPWE).
Groundwater Level Logging
Datalogging of groundwater levels in the area of the CPWE and Hensley Athletics Field have been undertaken in response to a request from the Department of Environment and Climate Change (now the Office of Environment and Heritage, OEH) to determine whether the groundwater flow is affected by operation of the groundwater production bores at and nearby the field. The report was submitted to DECC in March 2009. It concluded that deep groundwater levels are significantly influenced by groundwater extraction from bores located along Denison Street, but the effect is transient (levels quickly restore themselves when the bore is switched off) and localised (levels are only drawn down close to the operating bores). Pumping from the bores has no observable effect on shallow groundwater levels, and the shallow groundwater flow directions are not significantly altered.
Soil Vapour Monitoring
Orica conducted soil vapour sampling at Hensley Athletics Field in September 2008. The data was used to undertake human health risk assessments for chlorinated and non-chlorinated hydrocarbons (the latter are thought to be associated with a non-Orica pipeline in the vicinity).
Results indicated that there was only one volatile chlorinated hydrocarbon detected in all of the soil gas sampling locations, and showed a clear distribution from the CPWE. The non-chlorinated hydrocarbons showed no discernible patterns or trends. Assessment of the data concluded that the chlorinated and non-chlorinated hydrocarbons reported in the soil gas beneath Hensley Athletics Field are not considered to be significant with respect to long-term inhalation exposures by any workers or recreational users at Hensley Athletics Field. The reports were provided to the OEH and the City of Botany Bay Council, and results were reported to Hensley Athletic field users.
Human Health Risk Assessment Report
The human health risk assessment (HHRA) associated with the CPWE was undertaken in accordance with the requirements of the HCB Management Plan set out by Australian and New Zealand Environment and Conservation Council (ANZECC). Since the initial assessment in 2002, the HHRA for the CPWE has been incorporated into the Consolidated Human Health Risk Assessment (CHHRA), which was conducted in 2005 and reported under the Groundwater Cleanup Project.
The CHHRA conclusions are considered in light of all monitoring results as they become available, and any changes to the risks are reported to appropriate authorities and the local community through the Community Participation & Review Committee (CPRC).