Ecologically Sustainable Development

Transcription

1 29 Ecologically Sustainable Development Ecologically Sustainable Development CHAPTER Introduction The EP&A Act requires Ecologically Sustainable Development (ESD) principles to be considered in the environmental impact assessment and decision making process. Schedule 2 of the EP&A Regulation requires the justification of the development or activity to be carried out in the manner proposed, having regard to biophysical, economic and social considerations, including the principles of ESD. Justification for the BGC Project from a biophysical, economic and social perspective has been considered in Chapters 3 to 5 and 10 to 26 of this EIS. This chapter describes the application of ESD principles to the BGC Project s design, development and environmental impact assessment. Project construction and operational outcomes are considered in respect of their support for, or consistency with, ESD principles Ecologically Sustainable Development In June 1990, the Commonwealth Government released the document Ecologically Sustainable Development: A Commonwealth Discussion Paper which provided a definition of the term ecologically sustainable development and aimed to institute a process of discussion on what Australians need to do to embrace ESD. The Commonwealth Government defined ESD as: using, conserving and enhancing the community s resources so that ecological processes, on which life depends, are maintained, and the total quality of life, now and in the future, can be increased. As part of the process of discussion instigated by the Commonwealth Discussion Paper, nine sectoral ESD Working Groups comprising government officials, industry, environment, unions, welfare and consumer groups were set up to provide advice on future ESD policy directions and to develop practical proposals for their implementation. The policy directions and recommendations made by the ESD Working Groups provided the foundation on which the National Strategy for Ecologically Sustainable Development (DEH, 1992) was developed. In December 1992, the Council of Australian Governments endorsed the strategy as a response to the need to implement a coordinated national approach to ensure that Australia s future development is ecologically sustainable. The Council of Australian Governments (COAG) agreed that the future development of all relevant policies and programs, particularly those that are national in character, should take place within the framework of the National Strategy for Ecologically Sustainable Development and the Intergovernmental Agreement on the Environment (IGAE) (DEH, 1992). The IGAE is an initiative that attempts to devise a national environmental strategy for Australia through intergovernmental cooperation. Botany Groundwater Cleanup Project Environmental Impact Statement 29-1

2 CHAPTER 29 Ecologically Sustainable Development The principles that would assist in the achievement of ESD have been clearly set out in Schedule 2 of the EP&A Regulation. These principles are: the precautionary principle namely, that if there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation. inter-generational equity namely, that the present generation should ensure that the health, diversity and productivity of the environment is maintained or enhanced for the benefit of future generations. conservation of biological diversity and ecological integrity namely, that a full and diverse range of plant and animal species should be maintained. improved valuation, pricing and incentive mechanisms these mechanisms would enable environmental factors to be included in the valuation of assets and services. The four principles are inter-related. For instance, inter-generational equity can only be achieved in many instances if biodiversity is conserved for the use and enrichment of future generations. The linking of these four principles means that they must be considered both individually and collectively when assessing whether the BGC Project would contribute to ESD in Australia Application of ESD to Project Design and Development The BGC Project as a whole is focused on the principles of ESD, as it is designed to clean up the contamination legacies of many years of industrial activity on the BIP for the current and future generations in the local communities, through: protecting the aquatic environments in Penrhyn Estuary and Botany Bay from harm; restoring and maintaining the full recreational uses of Foreshore Beach and Botany Bay for the local communities; cleaning up the groundwater aquifers, to potentially enable future ongoing sustainable use of this valuable resource; and reusing the treated groundwater where possible, to maximise the output from the resources required in the containment and treatment process, and to reduce the current demands on the water supply from Sydney Water from the BIP and from other industrial operations in the Project Area. However, Orica (and the DEC, through its NCUA) recognise that proceeding with a containment/treatment project that merely transferred the contamination from the groundwater to another environmental medium, such as the air, with other potential impacts, would not be an acceptable approach, nor would it meet the principles of ESD. Orica has therefore adopted an iterative approach to the development and conceptual design of the BGC Project. This has involved extensive research, technology assessment and expert technical input, as well as stakeholder and community consultation, to ensure that measures to protect the environment and socio-economic amenity have been adequately incorporated into all aspects of the project. The GTP 29-2 Botany Groundwater Cleanup Project Environmental Impact Statement

3 Ecologically Sustainable Development CHAPTER 29 design was developed in accordance with the precautionary approach, and would use best practice techniques and technologies to minimise uncertainty and to avoid, minimise or mitigate potential environmental and socio-economic impacts. The concept of inter-generational equity was a driving force behind the BGC Project, and the principle of conservation of ecological integrity was also incorporated into the project s design and development. These four principles of ESD, and their relationship to the proposed BGC Project, are outlined below Precautionary Principle The EP&A Regulation 2000 provides the following definition of the precautionary principle: Where there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation. In the application of the precautionary principle, public and private decisions should be guided by careful evaluation to avoid, wherever practicable, serious or irreversible damage to the environment; and an assessment of the risk-weighted consequences of various options. To satisfy the precautionary principle, emphasis must be placed on anticipation and prevention of environmental damage (i.e. being proactive rather than reactive). The environmental impact assessment process itself is precautionary in nature, as it provides a public procedure to assess and evaluate uncertainty about the environmental consequences of a development prior to a project proceeding. Throughout the development of the BGC Project, Orica has adopted an anticipatory approach to the identification and mitigation of the risk of serious or irreversible ecological damage, by using proactive design solutions and undertaking an appropriate level of environmental research and assessment. This approach was adopted from the start of the BGC Project, through the extensive research and technology assessment undertaken by Orica, and separately by URS in an independent study (as detailed in Chapter 4), to identify best practice techniques and technologies for the containment, extraction and treatment of the contaminated groundwater. As a result, the BGC Project will utilise the best available technologies that have been proven to be effective for use in similar groundwater cleanup applications around the world, particularly in nations that have very strict environmental policies and regulations, such as Japan, the USA and the European Union. Having identified the technologies for the GTP, eight detailed investigations and assessments were undertaken as part of the impact assessment process. These were completed by relevant specialists, and separate detailed reports have been prepared. These assessments included: site contamination and geotechnical assessment; hydrogeological assessment of groundwater containment and extraction; hydraulic assessment; noise assessment; Botany Groundwater Cleanup Project Environmental Impact Statement 29-3

4 CHAPTER 29 Ecologically Sustainable Development ecological assessment; air emissions and air quality assessment; preliminary hazard assessment; and health risk assessment. These investigations have been used as source materials for this EIS and have been appended to support the various chapters. The findings from the key studies air quality assessment, preliminary hazard assessment and health risk assessment have shown the following results: Air quality (detailed in Chapter 22): The assessment shows that the maximum emissions to air from the BGC Project would not be expected to have a significant impact on air quality in the Project Area, and would be fully compliant with applicable assessment criteria. Preliminary hazard assessment (detailed in Chapter 23): The assessment shows that the risk associated with the BGC Project complies with DIPNR guidelines for all tolerable fatality, injury, irritation and societal risks. Health risk assessment (detailed in Chapter 24): The assessment shows that the level of risk associated with exposure to chemicals which may be emitted from the GTP is considered to be low, and representative of negligible or zero risk to human health. This EIS identifies mitigation measures and environmental management procedures that would be implemented to minimise and monitor impacts that may occur as a result of uncertainties in the impact assessment. Such uncertainties would not pose a risk of serious or irreversible damage, because they have been considered in the context of worst case scenarios that conservatively anticipate environmental impacts, and would be appropriately managed during the construction and operation of the BGC Project. In addition, in light of such potential uncertainties, extensive regular monitoring would be carried out (as detailed in Chapter 28) in accordance with regulatory requirements. In the unlikely event that deviations from expected conditions were recorded, the matter would be investigated immediately and appropriate action taken as necessary, to prevent any adverse environmental impact Inter-generational Equity Inter-generational equity has been defined in the IGAE as: The present generation should ensure that the health, diversity and productivity of the environment is maintained or enhanced for the benefit of future generations. The principle includes both intra-generational equity (within generations) and inter-generational equity (between generations) Botany Groundwater Cleanup Project Environmental Impact Statement

5 Ecologically Sustainable Development CHAPTER 29 Intra-generational equity requires that the economic and social benefits of development be distributed appropriately among all members of the community. Inter-generational equity requires that the development be managed so that the environment is maintained or enhanced and future generations are not disadvantaged by long-term impacts of the development. The most significant aspect of this concept is that future generations should not inherit a degraded environment. The overall aim of the BGC Project is based on the principle of inter-generational equity, since the hydraulic containment and treatment of the contaminant plumes would: redress contamination from past operations, when environmental standards and scientific understanding of potential environmental impacts were not what they are today; and avoid the future potential environmental impacts of contaminant discharge into Penrhyn Estuary and Botany Bay, and hence ensure that the existing environment is preserved for the benefit of future generations. Therefore, through containment of the plumes, the BGC Project would maintain the health and diversity of the environment for the benefit of future generations. The BGC Project also has benefits in terms of maintaining and enhancing the productivity of the environment. Preventing discharge of the contaminants would protect the extensive recreational uses of Foreshore Beach and Botany Bay. This would be a positive benefit for both intra-generational and intergenerational equity, because it would maintain the health and productivity of the biological environment for current and future generations. Similarly, removal of the contaminant plumes is positive for intergenerational equity, since it may enable the future ongoing sustainable use of the valuable groundwater resource. In addition, through its commitment to contaminant containment with concurrent treatment (i.e. destruction) using best practice technologies, Orica s approach is designed to ensure that future generations are not exposed to, or required to manage, a contamination legacy or a waste stream (such as an inventory of a stored waste EDC liquid recovered from a steam stripping operation). The three key project studies have identified no issues for human health, air quality or risk that would have negative impacts on inter- or intra-generational equity from the operation of the BGC Project through its estimated 30 year time frame. In summary, since the BGC Project would deliver long-term environmental and social benefits without degrading the broader environment, it is consistent with the principles of inter- and intra-generational equity Conservation of Biological Diversity and Ecological Integrity Preserving biological diversity and ecological integrity requires that ecosystems, species and genetic diversity within species be maintained. The primary objective of the BGC Project is to contain the contaminant plumes and stop contaminant discharge into Penrhyn Estuary and Botany Bay. While the potential impact of discharge of the contaminant plumes into the estuary and bay is uncertain (see Chapters 12 and 20), it would be expected that ongoing and increasing exceedances of the ANZECC guidelines for the contaminants in Botany Groundwater Cleanup Project Environmental Impact Statement 29-5

6 CHAPTER 29 Ecologically Sustainable Development the groundwater may lead to significant impacts on the biological diversity and ecological integrity of both Penrhyn Estuary and Botany Bay. Therefore, the primary objective is directly linked to preserving biological diversity and ecological integrity through maintaining ecosystems, species and genetic diversity within species. As discussed in Chapter 20, no significant potential impacts on the aquatic or bird life in Penrhyn Estuary have been identified as a result of the reduced discharge of groundwater and surface water into the estuary (due to the containment of the groundwater). In addition, the different works sites within the Project Area are all in areas subject to significant disturbance and modification by existing and previous industrial and construction activities and operations, which have resulted in a significant lowered historical biological diversity in the area. It is therefore concluded that, overall, the BGC Project would maintain biological diversity and ecological integrity in the Botany region, through its primary objective of preventing the contaminant plumes discharging into Penrhyn Estuary and Botany Bay Improved Valuation and Pricing of Environmental Resources The IGAE and the Protection of the Environment Administration Act 1991 both call for improved valuation, pricing and incentive mechanisms, which should form an element of policy making and program implementation. In other words, environmental factors should be included in the valuation of assets and services. Cost-benefit analysis can be applied to help decide how to proceed towards sustainable development. It is a means of reaching decisions in an objective and rational manner, by allowing the costs of proceeding with a proposal to be measured against the benefits arising from the proposal. It is difficult, however, to assign a monetary value to the environment of a locality or to environmental resources not considered for commercial use. Nevertheless, it is widely recognised and accepted that the environment of Botany Bay is of immense value. Therefore, the approach taken for the BGC Project has been twofold: committing Orica s extensive financial, commercial and technical resources to addressing the groundwater problem, both in the long term (since the early 1990s) and in the more immediate term, to achieve the objectives of containment and cleanup of the contamination, thus demonstrating its commitment to local communities and meeting the requirements of the NCUA. As discussed in Chapter 25, Orica has committed a total of $102 million to the capital cost of the BGC Project; and managing the potential environmental impacts of the project by identifying appropriate safeguards to mitigate adverse environmental effects, and incorporating the cost of implementing these safeguards in the total cost of the BGC Project Botany Groundwater Cleanup Project Environmental Impact Statement

7 Ecologically Sustainable Development CHAPTER Conclusion The BGC Project has been designed to achieve containment and cleanup of the identified contaminant plumes in the groundwater in the Project Area. The principal objective of the project is to avoid discharge of the contaminants into Penrhyn Estuary and Botany Bay, thereby protecting the biological diversity and ecological integrity of the area, and maintaining recreational activities for local communities. The project is a significant and long-term commitment to cleaning up legacy contamination arising from many years of industrial activities, and represents a significant step towards an ecologically sustainable future for the important groundwater aquifer of the Botany region. It has been developed and designed in accordance with four key principles of ESD, and appropriate mitigation measures have been identified where necessary. Based on the analyses outlined in this chapter, and the implementation of mitigation measures as identified throughout this EIS, undertaking the BGC Project in the manner proposed is justifiable, taking into consideration the principles of ESD. Botany Groundwater Cleanup Project Environmental Impact Statement 29-7

8 30 Justification and Conclusion Justification and Conclusion CHAPTER Introduction To assess whether the BGC Project is justified, the following aspects of the proposal (as defined by the DGRs and other comments from regulatory authorities, presented in Chapter 7 and Appendix C) must be considered: ability to meet the identified needs and objectives for the project; consistency with regulatory requirements and policy objectives; environmental benefits and impacts; social benefits and impacts; economic benefits and impacts; and consistency with the principles of Ecologically Sustainable Development (ESD). The consequences of not proceeding should also be examined. These issues are discussed throughout this EIS and summarised below The Proposal The BGC Project, which has been developed to achieve hydraulic containment and treatment of the identified contaminant plumes in the Project Area, consists of a number of integrated works, as illustrated in Figure 1.3 and summarised as follows: Primary Containment Area: Extraction of contaminated groundwater from wells installed in Southlands Block 1 and Block 2, and transfer of the groundwater via the primary pipeline to the ex situ GTP located on the BIP (interim transfer and treatment would be in the SSU, until the GTP was commissioned); Secondary Containment Area: Extraction of contaminated groundwater from wells installed on the median strip of Foreshore Road, and transfer of the groundwater via the secondary pipeline to the ex situ GTP located on the BIP (interim transfer and treatment would be in the SSU, until the GTP was commissioned); DNAPL Containment Line: Extraction of contaminated groundwater from wells installed along and parallel to the western boundary of the BIP, and transfer of the groundwater via the DNAPL pipeline to the ex situ GTP located on the BIP; treatment of contaminated groundwater, using a process consisting of air stripping and thermal destruction of the extracted contaminants, plus several water treatment stages to render the groundwater suitable for other uses, by achieving a water quality based on a combination of the ANZECC Marine Guidelines (ANZECC, 2000), Australian Drinking Water Guidelines and process standards for reuse; and Botany Groundwater Cleanup Project Environmental Impact Statement 30-1

9 CHAPTER 30 Justification and Conclusion transfer of treated groundwater for use in process operations across the BIP and by other industrial users in the Botany area, with excess discharged to Botany Bay via Brotherson Dock, through a discharge pipeline into Bunnerong Canal. The design of the GTP is based on a total groundwater extraction rate of up to 15 ML/day across the three containment lines, with continuous operation for an operating life of up to 30 years Ability to Meet the Needs and Objectives for the Project This EIS has considered various technical alternatives, as described in Chapter 4. The preferred alternative has been described in detail and the potential impacts of the preferred alternative on the environment have been assessed. In doing so, the EIS has demonstrated that the preferred alternative meets the needs and objectives of the project, as identified in Chapter 3. The overall objective of the BCG Project is to achieve the hydraulic containment and contaminant reductions specified by the NCUA, through the use of best practice techniques and processes. The means by which the proposed BCG Project would meet the specific objectives of the NCUA are summarised in Table Table 30.1 Ability to meet identified project needs and objectives Need/Objective Achieve groundwater containment in both the Primary Containment Area and the Secondary Containment Area to contain the contaminant plumes and prevent discharge of the contaminants at levels greater than the ANZECC (2000) values for slightly to moderately disturbed ecosystems into Penrhyn Estuary and Botany Bay Achieve a reduction in the concentration of the contaminants in the groundwater at the Primary Containment Area, to the maximum extent practicable, using ex situ treatment by 31 October 2005, with a target of an 80%reduction on the levels set out in the Orica 2002 Annual Report to the EPA (Orica, 2003). Ways In Which Need/Objective Is Met The groundwater containment network has been specifically designed to achieve hydraulic containment of the contaminant plumes, through the extensive groundwater modelling work undertaken to identify the optimum locations for the extraction pumps on the primary and secondary containment lines. The modelling incorporated validation work, based on particle tracking, which demonstrates the capture effectiveness of the extraction well network, meeting the contaminant containment requirements of the NCUA (see Appendix A). The groundwater modelling work included targeting the primary containment line to achieve containment of the plumes in the Primary Containment Area. The process selection and design of the ex situ GTP have been undertaken to maximise the effective treatment of the extracted contaminants, and it is expected that the contaminant concentrations would be rapidly reduced once operational. Additional modelling work is currently being undertaken to assess and confirm the concentration reductions and timescales to be achieved Botany Groundwater Cleanup Project Environmental Impact Statement

10 Justification and Conclusion CHAPTER 30 Need/Objective Contaminant plume cleanup to include: prevention of further contaminant migration beyond containment lines, allowing gradual cleanup of down gradient areas; and assisting DNAPL removal projects by providing containment for potentially increased concentrations of mobilised contaminants. Undertake sufficient monitoring, under the monitoring framework presented in the GCP, to monitor changes in concentrations of the contaminants, their spatial distribution and groundwater levels, to assess the effectiveness of the hydraulic containment and treatment within the treatment plant. Ensure that any emissions to the environment from works and measures required by the NCUA would be strictly controlled through the adoption of best practice, including the adoption of specific measures to minimise air emissions, and to ensure no detrimental effects to the environment and human health. Ways In Which Need/Objective Is Met The design of the groundwater containment network includes three containment lines to achieve containment of contaminant plumes, with the DNAPL containment line on the BIP, the primary containment line on Southlands, and the secondary containment line on Foreshore Road. The aim is to provide as comprehensive containment as possible for the identified plumes, to capture and clean up down-gradient migration. The modelling has shown the capture effectiveness of the network, preventing migration beyond the containment lines, and allowing gradual cleanup through extraction and treatment of the contaminants. The BGC Project includes the DNAPL containment line, specifically designed for the containment and treatment of mobilised contaminants within the BIP; and the PCA line, designed for the containment and treatment of mobilised contaminants between the BIP and Southlands. The operation of the contaminant containment and extraction network would incorporate an extensive monitoring program to assess the effectiveness of the BGC Project. This monitoring program would incorporate two specific aspects: containment lines: monitoring of groundwater levels, flows and electrical conductivity, to gauge the effectiveness of the containment, preventing further movement of the groundwater and contaminants; and contaminant plumes: use of existing monitoring wells, downgradient of the containment lines, to monitor changes in concentrations of the contaminants and their spatial distribution. The technology selection and process design for the GTP was based on extensive review of applicable technologies and selection of process technology that would achieve the required treatment capacity to be operational within the timescale required by in the NCUA, and achieve best practice emissions to atmosphere. As well as the high destruction efficiency of the thermal oxidiser to minimise emissions of VOCs, the technology selection includes proven design to minimise dioxin formation and the acid absorber and caustic scrubber to minimise acid gas emissions Environmental Benefits and Impacts The BCG Project would deliver the following environmental benefits: hydraulic containment of the contaminant plumes identified in the groundwater aquifers to prevent further movement of the contaminant plumes, in turn preventing the potential discharge of high concentrations of contaminants from both groundwater and surface water into Penrhyn Estuary and Botany Bay, thereby avoiding potential impacts to human health and/or on the biological diversity and ecological integrity of the area; Botany Groundwater Cleanup Project Environmental Impact Statement 30-3

11 CHAPTER 30 Justification and Conclusion treatment of the contaminated groundwater to achieve a high water quality, based on ANZECC Marine Guidelines, Australian Drinking Water Guidelines and process water standards for reuse; treatment of the contaminated groundwater to produce a high quality marine discharge stream, based on ANZECC Marine Guidelines to allow discharge to be safely returned to the environment; effective destruction of the volatile organic compounds (VOCs) in the contaminated groundwater, using best practice technologies with high destruction efficiencies to break down the contaminants into simpler compounds that can be safely disposed of; and maximising reuse of treated water by the BIP and other nearby users to reduce demand on towns water supply. Potentially adverse environmental impacts would include: short-term impacts on the Penrhyn Estuary and part of Foreshore Beach ecosystems, and potential long-term changes in species composition, due to the reduced discharge of groundwater; emissions to air from the destruction of the VOCs, with potential associated risks to human health; greenhouse gas emissions from the treatment process, through the inherent energy consumption of the high destruction efficiency technology selected; and construction related impacts such as noise and traffic. Construction impacts would be temporary, and would be minimised by the selection of appropriate construction methodologies and the implementation of mitigation measures identified in this EIS and detailed in Environmental Management Plans to be developed in consultation with, and subject to approvals from, relevant government agencies. These plans would include environmental management and monitoring measures as described in Chapters 27 and 28. The potential impacts on the nearby ecosystems have been assessed as detailed in Chapter 20, with the conclusion that the operation of the BGC Project would not cause significant impacts on the terrestrial or marine flora and fauna. Those impacts identified would be significantly less than if there were no containment and the contaminant plumes were discharged into the estuary. The potential impacts on air quality in the Project Area have been assessed as detailed in Chapter 22, with the conclusion that the operation of the BGC Project would not cause significant impacts on local or regional air quality, with no potential exceedances of air quality criteria. Similarly, the potential risks to human health, arising from the very low level emissions of remaining VOCs and dioxins and furans, have been assessed in Chapter 24, and are considered to be negligible, with no implications for human health impacts Botany Groundwater Cleanup Project Environmental Impact Statement

12 Justification and Conclusion CHAPTER Socio-Economic Benefits and Impacts The key social benefits of the BGC Project would arise through reducing the local community s concerns about the potential ecological and human health impacts of contaminant discharge to Penrhyn Estuary and Botany Bay, and the potential for future lifting of the current restrictions on the use of the groundwater and on recreational activities in and around Foreshore Beach (subject to approval from DIPNR). The major economic impact of the project would be positive, since the construction phase of the project would be likely to increase demand for local goods, services and labour. Some additional economic activities would also be likely to be generated by the construction and operation of the GTP. In addition, the project would create a significant economic benefit by avoiding the potential economic and social costs that would be likely to arise from the impact of unrestricted contaminant discharges for example, ecological impacts on flora and fauna in Penrhyn Estuary with consequences for the wider ecosystem and recreational fishing in Botany Bay, potential impacts on human health, and ongoing restrictions on recreational activities on Foreshore Beach and Botany Bay Consistency with Ecologically Sustainable Development Consideration and incorporation of the principles of ESD in the design and development of the BCG Project are discussed in Chapter 29. Undertaking the BCG Project in the manner proposed is justifiable, taking into consideration the principles of ESD Consequences of Not Proceeding The need for the BCG Project has been discussed in Chapter 3, and centres on the need to achieve the hydraulic containment and treatment of the identified contaminant plumes in the groundwater in the Project Area to meet the requirements of the NCUA. If this need were to be disregarded, and the do nothing option pursued, Orica would not be able to extract groundwater at the rates required (up to 15 ML/day) to contain the plumes and provide treatment of this volume of groundwater. The SSU as a contingency is limited to an approximate volume of 2 ML/day. Consequently, Orica would not be able to implement a proven process for the long-term containment and treatment of the contaminant plumes. As a result, the identified chlorinated contaminants in the groundwater plumes would be expected to discharge into Penrhyn Estuary and Botany Bay at increasing concentrations. Such discharges would likely result in a number of unacceptable outcomes, including: impacts on the terrestrial and marine flora and fauna in the Foreshore Beach and Penrhyn Estuary ecosystems, which could affect the migratory shorebirds listed under the EPBC Act 1999, with associated implications for compliance with Commonwealth obligations under international treaties (such as CAMBA and JAMBA); increased risks to human health for recreational users on the foreshore and within Botany Bay, diminished quality of life for residents and workers in the area; and Botany Groundwater Cleanup Project Environmental Impact Statement 30-5

13 CHAPTER 30 Justification and Conclusion failure to achieve the aims of the NCUA and the associated GCP, through failure to provide hydraulic containment and hence prevent contaminant discharges below the level required by the ANZECC (2000) trigger values for protection of slightly to moderately disturbed ecosystems. The do nothing option would be socially and environmentally unacceptable Sustainability of the Proposal The proposal is sustainable in terms of: efficiently meeting the project needs and objectives; the adoption of a precautionary approach to the design of the elements of the BGC Project, and the analysis, assessment and management of impacts and risks to the environment; social and inter-generational equity considerations; conservation and protection of biodiversity and ecological integrity; and reflecting the value of environmental resources through the inclusion of environmental protection activities, initiatives and mitigation measures in the total project cost Conclusion The BGC Project is designed to meet the requirements of the NCUA by achieving hydraulic containment of the identified contaminant plumes, to prevent discharge from the groundwater into Penrhyn Estuary and Botany Bay, and to remove and destroy the contaminants safely and effectively. Hydraulic containment is a proven technique for groundwater cleanup. The operation of the three containment lines would implement this technique for containment of the identified contaminant plumes to prevent contaminant discharge from the groundwater into Botany Bay. The selected treatment technologies to be used in the GTP are based on the use of best practice and proven equipment to achieve effective destruction of the contaminants, and to control and minimise emissions to air, including dioxins and furans. The treatment technologies have also been selected to ensure that the groundwater treatment achieves a water quality that meets a combination of recognised standards, comprising the ANZECC Marine Guidelines, Australian Drinking Water Guidelines and process water standards for reuse. The BGC Project also incorporates an extensive monitoring program, to continually assess the effectiveness of the containment and treatment. As the project has been designed for flexibility, the results of the monitoring can be incorporated into the operation of the BGC Project (for example, by varying pumping rates to respond to changes in groundwater), so that the containment and treatment can be maximised throughout the project lifetime Botany Groundwater Cleanup Project Environmental Impact Statement

14 Justification and Conclusion CHAPTER 30 While the project would have significant environmental benefits, it is recognised that it would also have some unavoidable environmental impacts; however, these are relatively minor, and have to be balanced against the impacts that would occur if the containment and treatment were not implemented, and uncontrolled groundwater contaminant discharge occurred. A range of mitigation measures have been identified to minimise the impact on the environment. The environmental performance of the project would be monitored to ensure that the adopted environmental standards are met and maintained. It is considered that the construction and operation of the BCG Project is justified on the basis of its environmental acceptability, taking into account biophysical, economic and social considerations, and is in accordance with the principles of ESD. The BGC Project meets the identified project objectives, including the need to minimise the impact on the environment and the community. The BGC Project is consistent with key government policy objectives and the principles of ESD. Based on these conclusions, and considering the BGC Project against a wide range of criteria, undertaking the BGC Project in the manner proposed is justifiable. Botany Groundwater Cleanup Project Environmental Impact Statement 30-7