The overall objectives of this report are to provide an independent audit of the remediation works. The specific objectives, set out in the audit brief, were to assess:
2.1 Objectives
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the remediation of the persistent organochlorine pesticide contaminants present on the site;
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compliance with the remediation soil acceptance criteria;
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whether “clean-up to extent practicable” of the marine sediments has been achieved;
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the adequacy of the draft Site Management Plan;
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the current status of the groundwater;
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whether the land is fit for purpose; and
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the actual and potential environmental effects of the residual contamination on the site.
Further, the audit is to assess what, if any, monitoring (including from contaminants resulting from the remedial processes used e.g. copper and ammonia) is required to:
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ensure the continued safe use of the site; and
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determine the nature and effect of any on going discharges from the site.
Should the site not be fit for purpose, the Auditor shall determine the necessary steps to be taken to ensure the site is suitable for its intended use.
2.2 Scope
The scope is restricted to assessing the quality of soil, marine sediments and groundwater against various consent conditions, using the Site Validation Report, Groundwater and Sediment Monitoring Report, draft Site Management Plan and such other information as may be provided by MfE. The basis for the Auditor’s1 review was set out in the audit brief as follows:
| Medium | Assessment criteria | Scope of site auditor assessment |
|---|---|---|
| Soil | Compliance with the relevant soil acceptance criteria and an assessment of whether the land is fit for purpose. | Assessment of compliance with relevant SAC. Review of draft Site Management Plan prepared for MfE. Provision of comments and variations to the draft Site Management Plan, following review. |
| Marine sediments | Compliance with relevant soil acceptance criteria and an assessment of whether “clean-up to extent practicable” has been achieved. | Assessment of compliance with relevant SAC. If SAC have not been achieved, assessment of whether “clean-up to extent practicable” has been achieved. Review of draft Site Management Plan prepared for MfE. Provision of comments and variations to the draft Site Management Plan, following review. |
| Groundwater | Threshold values in the Resource Consents and applicable New Zealand Standards. | Review Groundwater Sediment Monitoring Report prepared for MfE and any additional material provided by MfE including the TDC groundwater and biota monitoring reports. Comment on the current status of the groundwater. Assessment of implications of groundwater on foreshore and marine environments and neighbouring properties. Recommendations of monitoring and management required for the site and neighbouring properties, if not covered in the draft Site Management Plan. |
| Ammonia and Copper | Human health and environmental effects. | Comment on information provided by the Ministry for the Environment. Recommendations of monitoring and management required for the site and neighbouring properties, if not covered in the draft Site Management Plan. |
The review of the draft Site Management Plan will be reported separately. However, where relevant, the audit comments on aspects that need to be controlled by the SMP.
The scope does not include:
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consideration of air quality;
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assessment of material that was taken off site for disposal;
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assessing compliance with consent conditions that do not relate to achieving relevant site acceptance criteria (SAC) or threshold values for soil, water and sediment; or
- a review of the conduct of the remediation process. The audit focuses on the current site status rather than ‘how it got there’, except where the process itself could affect the interpretation of data or the suitability of the site for its intended use.
1 Note: A Site Auditor was appointed as a consent condition to provide overview and technical advice during the remediation process – see Section . This is not the same as the current audit function.
2.0 Objectives and Scope
June 2009
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