COMMUNITY BRIEFING PAPER BOTANY GROUNDWATER PROJECT

Transcription

1 COMMUNITY BRIEFING PAPER BOTANY GROUNDWATER PROJECT ORICA AUSTRALIA PTY LTD 16 DECEMBER 2003 PURPOSE This briefing paper has been prepared as part of Orica s commitment to the Botany community to provide an update on the current status of discussions between Orica, NSW EPA and Department of Infrastructure Planning and Natural Resources (DIPNR) regarding the remediation of the Botany Groundwater and the Notice of Clean Up Action issued by the NSW EPA. BACKGROUND The NSW EPA issued Orica with a Notice of Clean Up Action (Notice) under the Protection of the Environment Operations (POEO) Act regarding chlorinated hydrocarbon (CHC) contamination in the Botany Groundwater resulting from historical operations at Botany. The Notice, issued on 26 September 2003, required Orica to prepare and submit by 31 October 2003 a Groundwater Cleanup Plan (Plan) for EPA s consideration. Orica submitted the Groundwater Cleanup Plan by the required date, and whilst the final acceptance of the Plan by the NSW EPA is still pending, Orica has been actively implementing the Plan. NOTICE OF CLEAN UP ACTION The Notice in broad terms requires Orica, to the maximum extent practicable, to contain and treat contaminated groundwater; to identify, contain and remove free phase chemicals, referred to as Dense Non-Aqueous Liquids (DNAPLs); and to regularly monitor and report on the state of contamination and remediation progress. A copy of the Notice is available on the EPA's web site The Notice refers to Primary and Secondary Containment Areas. The primary containment area is defined as part of Orica land known as Block 2 of Southlands. This is the parcel of open land bounded by McPherson Street, Springvale Drain and Floodvale Drain, where the highest concentrations of chlorinated hydrocarbons including ethylene dichloride (EDC) have been detected. In the primary containment area the Notice requires hydraulic containment and ex situ (above ground) treatment. The hydraulic containment aims to stop the contaminated groundwater moving further downgradient by pumping out the groundwater from a line of extraction bores. The above ground treatment will then be required to remove the contaminants from the groundwater that is extracted from the aquifer. The Notice also requires the reduction of concentrations of contaminants in the primary containment area to the maximum extent practicable. This must be achieved using above ground treatment. The Notice also stipulates that a secondary containment area is required to ensure that any contamination that has already passed the primary containment area does not reach Botany Bay. This secondary containment area needs to be installed in the vicinity of Foreshore Road and the Botany Golf Course. Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 1 of 9

2 The Notice also requires Orica to identify, contain and remove to the maximum extent practicable, sources of free phase chemicals (referred to as Dense Non-Aqueous Phase Liquids or DNAPLs). Orica is also required to maintain concentrations in surface and groundwater discharges within the relevant requirements of the Australia and New Zealand Guidelines for Fresh and Marine Water Quality (2000), and to regularly monitor and report the status of groundwater contamination and remediation system performance. TIMING ISSUES The Notice, and the Plan by necessity, require a focused approach to project implementation. The Plan includes, in many cases, simultaneous development of more than one option to achieve the remedial objectives pending the results of bioremediation field trials currently under construction on Orica Southlands. Some of the projects are interim measures until the Groundwater Treatment Plant (proposed as the major ex situ treatment process) can be constructed and become operational. Orica wants to complete these interim projects as early as practicable to facilitate faster capture and treatment of the highest concentration sections of the contaminant plumes. The ability to meet the timing obligations specified in the Notice is dependent to a significant extent on the planning and development process requirements under the Environmental Planning and Assessment Act, which DIPNR administers. Orica will work closely with both the EPA and DIPNR to resolve these potential timing impacts. THE GROUNDWATER CLEAN-UP PLAN (Plan) Approval of the Plan by the EPA is still pending. When finalised it is expected to be made available by the EPA and it will be publicly available in local libraries. In the meantime, the following is an outline of what Orica has proposed in the Plan it submitted to the EPA on 31 October Orica has proposed a large number of projects to meet the requirements of the Notice to the maximum extent practicable. These are listed on the following pages. For the primary containment area Orica proposes the construction and operation of a Groundwater Treatment Plant at Botany Industrial Park (BIP). While planning for this major project gets underway, a number of interim projects will also be undertaken. The interim projects aim to provide early interception of the groundwater until the ex situ treatment plant can be constructed and starts operating. Of these, the most significant (in capacity and complexity) is the recommissioning (if feasible) of a redundant steam stripping unit at BIP. Orica would prefer to put in place full-scale bioremediation instead of extraction and above ground treatment of the groundwater. However, the feasibility of bioremediation must first be proven during the field trials currently under construction on Block 2 of Southlands. Nevertheless, Orica is also developing a number of contingency projects for the primary containment area. The contingency projects are intended to operate in the event that the bioremediation field trials fail. The secondary containment area proposes bioremediation as the preferred technology. Once again, if the bioremediation trials fail, it is proposed that infrastructure for hydraulic containment and above ground treatment will be established as a contingency. Treatment would occur at the Groundwater Treatment Plant at BIP, or in the recommissioned steam stripping unit at BIP. Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 2 of 9

3 The Plan highlighted several practical concerns with hydraulic containment relating to the potential adverse impact on the regional aquifer particularly relating to the rate of extraction required to capture the groundwater. Orica maintains that if the bioremediation trials prove to be successful, once scaled up into full operation, primary containment of contamination can be achieved in a shorter timeframe than is required to establish the Groundwater Treatment Plant, and will minimise the potential adverse impacts because groundwater would not be extracted. A. Primary Containment Area Projects Major Project: Design and Construct Groundwater Treatment Plant Interim Projects: 1. Off-site disposal trial through Waste Service NSW Liquid Treatment Plant at Lidcombe 2. Block 2 interim Storage and Tanker Loading Facility 3. Recommissioning of Vinyls Plant Steam Stripping Unit 4. Hydraulic Containment Infrastructure (e.g. extraction wells network, pipeline to BIP) to support major project and interim projects. B. Secondary Containment Area Projects 5 Passive Bioremediation Barrier on Foreshore Road 6. Active Bioremediation in the vicinity of Botany Golf Course Contingency Plans for Secondary Containment 7. Hydraulic Containment Infrastructure (to feed into the ex situ Groundwater Treatment Plant or Steam Stripping Unit) 8. Interim Storage and Tanker Loading in secondary containment area 9. Reactive Iron Barrier for Southern Plumes 10. Passive Bioremediation Barrier for Southern Plumes C. DNAPL Containment Projects 11. Passive Bioremediation Barrier EDC Storage/Vinyls Plant Source Area 12. Hydraulic Containment EDC Storage/Vinyls Plant Source Area 13. Passive Bioremediation Barrier Springvale Drain Protection 14. Hydraulic Containment Springvale Drain Protection 15. Reactive Iron Barrier Solvents Plant/TCE Plant/Southlands Block Passive Bioremediation Barrier downgradient from Reactive Iron Barrier CTC/PCE Storage Area 18. Passive Bioremediation Barrier CTC/PCE Storage Area 19. Hydraulic Containment CTC/PCE Storage Area 20. Passive Bioremediation Barrier HCB Drum Store/Redrumming Areas 21. Hydraulic Containment HCB Drum Store/Redrumming Areas 22. Passive Bioremediation Barrier Open Drum Storage Areas, Northern BIP 23. Hydraulic Containment Open Drum Storage Areas, Northern BIP These projects are described in more detail below. Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 3 of 9

4 A. PRIMARY CONTAINMENT AREA PROJECTS MAJOR PROJECT Design and Construct Groundwater Treatment Plant Indicative duration implementation: November 2003 August 2005 Orica expects that the proposed Groundwater Treatment Plant (GTP) will be two-streamed. Stream 1 capacity will be designed to meet the extraction requirements for the primary containment area. Orica s preliminary estimate of the volume of groundwater to be extracted to effect hydraulic containment of the primary containment area is between 1 million and 1.3 million litres per day (1-1.3 ML/d). As an indication of scale, this is roughly standardsized road tanker loads per day. The Notice requires additional extraction from the primary containment area to maximise concentration reduction. Preliminary modelling indicates this additional rate may be limited to approximately 1 ML/d to control adverse impacts on the Botany aquifer (drawdown, subsidence). Stream 2 capacity will be designed to treat the volume of groundwater being extracted from the secondary containment area, as well as the DNAPL groundwater containment lines. Preliminary estimates of total extraction for these areas is 5 ML/d. This stream will be required if the bioremediation trials prove to be ineffective, leaving hydraulic containment and above ground treatment as the only practicable containment technology. If bioremediation trials are successful, Stream 2 would not be required. Stream 1 would also only proceed if the EPA did not accept that bioremediation can deliver required contaminant containment in lieu of hydraulic containment and ex-situ treatment. This proposed plant would be located on BIP for easy integration with existing site operations and infrastructure. Recycling of the treated groundwater on BIP is preferred, however disposal by reinjection to the aquifer, to stormwater, or to sewer may be required. These options will all be evaluated when implementing the Plan. An environmental impact statement (EIS) will probably be required for this plant. There are potential timing constraints imposed by the Notice that may impact on the planning obligations stipulated under the Environment Planning and Assessment Act. Orica will work closely with both DIPNR (the consent authority) and the EPA to ensure the objectives of the Environmental and Planning Assessment Act can be met and the potential impact this process will have on timing compliance with the Notice can be minimised. INTERIM PROJECTS There are a number of interim projects proposed that will run in parallel to the major projects and these are described below. The interim projects will be implemented and operated sequentially until ultimately the ex situ Groundwater Treatment Plant is fully operational. These proposed interim projects all require statutory approval processes in their own right, and Orica is working closely with DIPNR to establish a framework that can allow the groundwater clean-up without compromising due planning and development processes. 1 Off-site disposal trial through Waste Services NSW Lidcombe Indicative timing - February 2004 Orica cannot commission a treatment plant immediately to treat extracted groundwater. Therefore Orica has looked for short-term offsite disposal options for the contaminated groundwater. One such option is the Liquid Treatment Plant operated by Waste Service NSW at Lidcombe. Following discussions with Waste Services NSW, Orica proposes to trial the disposal of a small volume of groundwater to the Liquid Treatment Plant at Lidcombe. The trial will consist of one tanker load each weekday for one month. The trial is to determine whether the groundwater can be accepted and treated at the Lidcombe Plant. If Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 4 of 9

5 successful, Waste Service NSW advise they may be able to process up to 100m 3 /day (5 tanker loads). The trial will be abandoned if Waste Services NSW is unable to treat the groundwater. 2 Block 2 Interim Storage and Tanker Loading Facility Indicative duration implementation:- December 2003 August 2004 Indicative duration operation: August 2004 October 2004 This proposed project is to establish an interim storage and tanker loading facility on Block 2 for both the offsite disposal (assuming the Lidcombe trials are successful) and the road tanker transport to the steam stripping unit. Two key issues to be addressed include emission control for tanker loading and management of potential spills. Installation of a full-scale pipeline to the steam stripping unit and the Groundwater Treatment Plant is also being investigated as an option for transporting the extracted groundwater rather than using tankers. 3 Recommissioning of Steam Stripping Unit (SSU) Indicative duration implementation: November 2003 October 2004 Indicative duration operation: October 2004 August 2005 Orica is currently assessing the feasibility of recommissioning the Steam Stripping Unit (SSU) of the redundant Vinyls Plant on the Botany Industrial Park as an interim measure so that a limited amount of groundwater can be treated sooner than A number of issues including the pumping and storage of groundwater, and the management of emissions will be addressed as part of the feasibility study. If the plant can be converted, if emission standards can be met, and if all planning approvals are granted, it is expected to have the plant commissioned by October Establish Hydraulic Containment Timing to meet above projects for disposal and treatment The Notice requires hydraulic containment downgradient of the site boundaries to intercept the spread of groundwater contamination from the primary containment area. This means installing groundwater extraction wells, in-well extraction pumps, collection piping, and piping to the Groundwater Treatment Plant, as well as necessary infrastructure for interim projects described above. The location of extraction wells, and the commencement and rate of extraction of groundwater from the primary containment area may compromise the integrity of the bioremediation field trials being conducted in the same area. Orica understands the need to comply with the timing requirements of the Notice and is working with the EPA to help overcome this issue. Early installation of a full-scale pipeline for the Groundwater Treatment Plant (with branch line to the steam stripping unit) is being investigated as an option for transporting the extracted groundwater to the steam stripping unit rather than using road tankers. B. SECONDARY CONTAINMENT AREA (SCA) PROJECTS The secondary containment area is defined by the Notice as an area upgradient of Botany Bay/Penrhyn Estuary for the capture of any contaminants that have, or may, migrate from the primary containment area. The intent of the secondary containment area is to intercept groundwater from the central EDC plume before reaching Botany Bay. Secondary containment is required by the Notice to be established by 31 October It is hoped that the bioremediation projects described below will meet that date. Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 5 of 9

6 5 Passive Bioremediation Barrier Indicative duration implementation: December 2003 October 2004 This passive barrier is expected to be located along Foreshore Road, on the southern side of the Golf Course. It requires installing a row of injection wells so nutrients can be added to the aquifer. These nutrients will promote the natural degradation of chlorinated hydrocarbons by microorganisms already present in the aquifer. The construction of the injection wells will commence before the bioremediation field trials are completed to avoid delays in intercepting the contaminated groundwater. These nutrients will be injected as soon as the success of the bioremediation field trials is determined and relevant approvals have been obtained. 6 Active Bioremediation Barrier Indicative duration implementation: December 2003 December 2004 The active bioremediation barrier is a replica of the proposed full-scale active bioremediation system from Block 2 Southlands (already under construction). A process is required to promote the survival and growth of the existing bacteria, as they only seem to breakdown CHCs at concentrations less than 1000 ppm. By extracting the high concentrations of contaminated groundwater from the core of the plume, mixing it with the lower concentrations extracted at the edges of the plume, and reinjecting it at less than 1000 ppm, the bacteria will survive and the CHCs will be degraded. By adding electron donors (nutrients) the population growth will expand and the rate of degrading the CHCs will increase. The system will require extraction wells (at the Botany Road side of Botany Golf Course), and reinjection wells (probably on the Foreshore Road side of Botany Golf Course), in-well extraction pumps, above ground mixing and electron donor storage and injection facilities. Design, procurement and construction will proceed in the expectation that the bioremediation field trials prove successful. This system would only become operational after the bioremediation field trials are proven successful and regulatory consent is obtained. 7 Hydraulic Containment Indicative duration implementation December 2003 to August 2005 Should the bioremediation field trials fail, groundwater extraction and ex situ treatment will be required to create secondary containment. Design, procurement and construction for this system will commence in parallel with the bioremediation options for the secondary containment area, as there is not time available under the Notice or time to intercept the plume given its rate of migration, to wait until a definitive result is obtained from bioremediation field trials. This project will require extraction wells, in-well extraction pumps, associated power supply, and piping back to the Groundwater Treatment Plant at BIP. Issues such as road crossings, and the need for easements will be managed in conjunction with the appropriate stakeholders. The extent of hydraulic containment at the secondary containment area is dependent on treatment options available. The duration shown is for the Groundwater Treatment Plant. Alternative schemes e.g, early installation of the pipeline to BIP to feed groundwater to the steam stripping unit, or storage and tanker loading at the secondary containment area (refer 8 below) will be required for earlier (partial) hydraulic containment. Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 6 of 9

7 CONTINGENCY PLANS FOR SECONDARY CONTAINMENT 8 Storage and Tanker Loading at secondary containment area This project is a contingency project. If the bioremediation trials are not providing encouraging results early on, and the schedule is indicating a late start up date for the Groundwater Treatment Plant, Orica may need to consider extraction of groundwater for road tanker transfer back to the Steam Stripping Unit. This would be to extract as much of the core of the central plume as practicable at the secondary containment area. 9 Reactive Iron Barrier for Southern Plumes A secondary containment installation using a reactive iron barrier for the Southern Plumes is discussed in the Plan. It would be required if: a) a study of the contaminant levels in Penrhyn Estuary suggests that groundwater discharge concentrations are exceeding ANZECC (2000) guidelines for fresh and marine waters, and further toxicity studies indicate the need for groundwater remediation, and b) bioremediation is inappropriate for the Southern Plumes at the secondary containment area (e.g.,if compounds that hinder the biological degradation such as carbon tetrachloride and chloroform are present in significant concentrations and/or the prevailing geochemical conditions do not favour bioremediation). 10 Passive Bioremediation Barrier for Southern Plumes A passive bioremediation barrier may be needed for the Southern Plumes at the secondary containment area if: a) a study of the contaminant levels in Penrhyn Estuary suggest that groundwater discharge concentrations are exceeding ANZECC (2000) guidelines for fresh and marine waters, and further toxicity studies indicate the need for groundwater remediation, and b) bioremediation is determined appropriate for the Southern Plumes at the secondary containment area based on microcosm studies and the success of the bioremediation field trials, or c) it is required downgradient of a reactive iron barrier to remove CHCs not degraded within the reactive iron barrier (primarily EDC) to meet ANZECC guidelines. It would effectively be a continuation of the line of the passive bioremediation barrier described in 5 above located further to the east to treat the Southern Plumes. C. DNAPL INVESTIGATION AND CONTAINMENT PROJECTS The Notice requires investigation to identify DNAPL source areas by 31 May The history of past work and proposed further investigations is detailed in the Plan. The Notice then requires contaminant containment around identified DNAPL source zones by 30 November The preliminary schedule in the Plan indicates that the bioremediation projects in general offer the best chance of meeting the latter target date. Inferred source areas of DNAPLs include: EDC Storage/Vinyls Plant Source Area Former Solvents Plant/TCE Plant/Block 1 Southlands Former CTC/PCE Storage Tank (Alkatuff Plant) HCB Drum Store/Redrumming Areas Open Drum Storage Areas, Northern BIP The following technologies are proposed at the inferred source locations listed above. Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 7 of 9

8 Passive Bioremediation Barriers Passive bioremediation barriers will require the installation of a row of injection wells. Nutrients can then be added to the aquifer via these wells to promote the natural biological degradation of chlorinated hydrocarbons in the groundwater. The systems for each of the passive remediation locations will only become operational after the field trials are proven successful. The indicative duration for implementation of these projects is dependent on bioremediation field trials success, i.e., December 2003 to October Hydraulic Containment Should the bioremediation field trials fail, groundwater extraction and ex situ treatment will be required for DNAPL containment. Design, procurement and construction for these systems will commence in parallel with the bioremediation options for DNAPL containment, as there is not time available under the NCUA to wait until a definitive result is obtained from bioremediation field trials. These projects will require extraction wells, in-well extraction pumps, associated power supply and piping back to the Groundwater Treatment Plant. The indicative implementation duration for these projects is therefore consistent with the Groundwater Treatment Plant project, i.e., November 2003 to August Reactive Iron Barriers As well as the bioremediation processes and hydraulic containment, two reactive iron barriers are likely to be installed to address some DNAPL source areas. This will be to address DNAPL containment at Solvents Plant/TCE Plant/Southlands Block 1 and at the CTC/PCE Storage Area (where the Alkatuff Plant is now located). A permeable reactive iron barrier will be installed to intercept and destroy CHCs from shallow and deep groundwater moving in the Southern Plume. It will be installed on Block 1 of Southlands, using either biopolymer trench or hydrofracturing technology. The alignment of the wall will probably run parallel and adjacent to Springvale Drain and McPherson Street. This project is one that had commenced under the Voluntary Remediation Agreement. The indicative implementation duration for this project in the Plan is November 2003 to April Another reactive iron barrier may be required at the former CTC/PCE Storage Area, to remove carbon tetrachloride to ensure that downgradient treatment for the overlapping plume from the HCB Store area can be contained using a passive bioremediation barrier. It will be installed downgradient of the Alkatuff Plant, using either biopolymer trench or hydrofracturing technology. The indicative duration for this project in the Plans is November 2003 to February D. DNAPL REMOVAL PROJECTS The Notice requires DNAPL removal from identified source zones to the extent practicable before 31 October Projects to achieve this objective are still being determined and will depend upon the results of further DNAPL investigations detailed in the Plan. Removal of DNAPL source zones is an inherently difficult exercise as the source areas are hard to delineate and then target with accuracy. Additionally, technologies and their application are still developmental. Complete removal is generally regarded as impossible, and the focus is on source depletion. Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 8 of 9

9 E. MONITORING AND REPORTING Orica will use appropriately structured project management practice to monitor and control progress of the Plan. Orica proposes to provide EPA with a progress report quarterly in conjunction with the monitoring report. Orica proposes to supply EPA with a copy of the 2003 Groundwater Monitoring Report as the first groundwater monitoring report under the Plan. Orica also commits to keeping the community informed of progress through the Community Liaison Committee and the quarterly CLC Newsletters. A community hotline is also available for feedback by local residents for further information. For further information contact: Orica Community Hotline Number: Community Briefing Paper GCP - 16 Dec 03 (Issued).doc Page 9 of 9