DETAILED REMEDIATION ACTION PLAN PHASE 2 COCKLE CREEK SITE REDEVELOPMENT BOOLAROO, NEW SOUTH WALES 25 MARCH 2010 DOC. REF: SG061313 RP06 REVISION 3 FOR INCITEC FERTILIZERS LIMITED Soil & Groundwater Consulting ADELAIDE MELBOURNE 207 The Parade • NORWOOD • SA • 5067 ACN 100 220 479 43 Stubbs Road • KENSINGTON • VIC • 3031 T: + 61 8 8431 7113 • F: + 61 8 8431 7115 ABN 62 100 220 479 T: + 61 3 9372 6800 • F: +61 3 9372 6900 EXECUTIVE SUMMARY This Detailed Remediation Action Plan (Detailed RAP) addresses the remediation of the Phase 2 portion of the Incitec Fertilizers Limited (IFL) Cockle Creek manufacturing and distribution site located on Main Road, Boolaroo, New South Wales. The overall site is identified as Lot 1 DP225720 and is shown in Figure 1. Phase 2 of the remediation works comprises: the Northern Area remediation; cell construction for the containment of contaminated soils from the Northern Area and the remainder of the site; and the construction of Ponds 1 and 2. It is noted that this Detailed RAP has been prepared for Phase 2 of the remediation works only and that subsequent Detailed RAPs are proposed to be prepared for Phase 3 (Central Area demolition and remediation works) and Phase 4 (Southern Area remediation) of the staged remediation works program for the site. It is noted that previous documents, in particular the Conceptual RAP, have referred to each phase of works as stages (i.e Stage 2, Stage 3 etc.). The nomenclature has changed although the overall programs remain essentially the same. The Detailed RAP has been prepared for the following purposes: 1 To form the basis for the remediation program to be instituted in the Northern Area of the site; 2 To provide a detailed framework for the development of a Construction Environment Management Plan (CEMP) which will retain the detail for the physical on site remediation implementation and the scope and monitoring associated with the health and environment management programs to be implemented throughout the Phase 2 remediation program; 3 To comply with the Director-General’s Environmental Assessment Requirements (the Requirements) pursuant to section 75F(3) of the Environmental Planning and Assessment Act 1979; 4 To comply with the Voluntary Management Plan (VMP) entered into with the Department of Environment and Climate Change (DECCW) pursuant to section 26 of the Contaminated Lands Management Act 1997 (CLM ACT 1997); 5 To remove the Declaration of Remediation Site and the Significant Risk of Harm orders for the site; and 6 To satisfy IPL Company Values. The objective of the Phase 2 Detailed RAP is to provide the framework for the remediation of the Northern Area of the site from its current industrial use, with historical impacts associated with Page ES(i) Revision 3 waste disposal from the former smelting operations which occurred at the adjacent site, to a site containing an area dedicated to a engineered containment cell (suitable for controlled open space uses). Following detailed soil and groundwater investigations across the site over a number of years, the extent and nature of contamination in soil and groundwater has been identified and delineated. This data set is considered to provide a sound basis on which to the develop the remediation strategy and ensure a successful outcome for the ongoing utilisation of the site for controlled public open space in the Northern Area and for residential uses within the Central and Southern Areas. An assessment of a number of potential remedial options was undertaken. This assessment determined that the most appropriate management approach at the site is to consolidate and isolate all the contaminated soil and other materials unsuitable for use within a residential setting in an engineered, fully lined containment cell located on the northern portion of the site (Phase 2) within the site boundaries. The removal of the heavy metal impacted soils (resulting from slag waste from the former smelter operations) which are the primary source of the identified groundwater contamination to a fully lined engineered containment cell will also remove the primary ongoing source of groundwater contamination at the site. In time, this would be expected to remove the Significant Risk of Harm posed by the residual groundwater contamination at the site and allow the order to be rescinded. Some targeted and short term groundwater remediation was undertaken and is ongoing for the Northern Area (within and adjacent the proposed containment cell area) to reduce the contaminant mass present in the groundwater system prior to the construction of the containment cell. To ensure ongoing environmental management of the area of the site incorporating the containment cell and a suitable buffer zone, IFL will retain the ownership and responsibility for this area, including the groundwater environment. This will ensure accessibility to the area for any future management requirements and will provide a viable entity for the implementation of the longer term environment management plan into the future. Page ES(ii) Revision 3 TABLE OF CONTENTS 1. INTRODUCTION.....................................................................................................................................1 1.1 Background ..................................................................................................................................1 1.2 RAP Objectives ............................................................................................................................1 1.3 Review of RAP by Auditor ............................................................................................................5 2. SITE IDENTIFICATION ...........................................................................................................................7 2.1 Site Details ...................................................................................................................................7 2.2 Site Boundaries............................................................................................................................8 2.3 Easements ...................................................................................................................................8 3. SITE HISTORY........................................................................................................................................9 4. SITE CONDITIONS...............................................................................................................................12 4.1 Topography ................................................................................................................................12 4.2 Geology......................................................................................................................................12 4.3 Hydrogeology .............................................................................................................................13 5. SOIL AND WATER ASSESSMENT CRITERIA.....................................................................................18 5.1 Contaminants of Concern...........................................................................................................18 5.2 Soil Assessment Criteria ............................................................................................................18 5.2.1 Potential Human Health Risks ....................................................................................... 19 5.2.2 Potential Ecological Risks.............................................................................................. 19 5.2.3 Leachability ....................................................................................................................20 5.2.4 Aesthetics ......................................................................................................................20 5.2.5 Building and Structures.................................................................................................. 20 5.2.6 Soil Remediation Assessment Criteria Summary........................................................... 21 5.3 Groundwater Assessment Criteria..............................................................................................23 5.3.1 Groundwater Remediation Assessment Criteria Summary............................................ 25 5.4 Buildings and Structures ............................................................................................................27 5.5 Surface Water Assessment Criteria ...........................................................................................27 5.6 Rationale for and Appropriateness of the Adopted Criteria ........................................................28 6. SITE CHARACTERISATION.................................................................................................................29 6.1 Contamination Status of Soils ....................................................................................................29 6.2 Contamination Status of Groundwater .......................................................................................32 6.3 Assessment of Possible Exposure Pathways and Receptors ....................................................37 7. REGULATORY COMPLIANCE REQUIREMENTS ...............................................................................39 7.1 State Planning............................................................................................................................39