Long Term Residue Management Strategy

Pinjarra 2016

Long Term Residue Management Strategy

Pinjarra 2016

Contents

Executive Summary 7 6.4 Flora 36 6.5 Fauna 36 1.0 Introduction 10 6.6 Heritage 36 1.1 Background and Site Overview 10 6.7 Existing Land Use and Tenure 37 1.2 Purpose of the Long Term Residue 10 6.8 Local, Regional and State Planning Policies and Visions 38 Management Strategy (LTRMS) 7.0 Existing Environmental Issues and 1.3 Structure of Report 10 Management Strategies 40 2.0 Background and History of the LTRMS 12 7.1 Environmental Management Systems 40 2.1 Initial LTRMS Development 12 7.2 Dust 40 2.2 2005 LTRMS Review 14 7.3 Odour and VOCs 44 2.3 2011 LTRMS Review 14 7.4 Radiation 46 2.4 2016 LTRMS Review 15 7.5 Residue Emissions and Health 47 2.5 Sustainability 15 7.6 Oxalate 49 2.6 Stakeholder Engagement 15 7.7 Water Use 49 2.7 Pinjarra LTRMS Stakeholder Consultation Process 16 7.8 Surface Water 51

3.0 Alumina Refining Process 20 7.9 Groundwater Impacts 52 7.10 Land Use Management and Visual Amenity 54 3.1 Overview 20 7.11 Residue Area Rehabilitation 57 3.2 Digestion 20 3.3 Clarification 20 8.0 Short and Medium Term Residue 3.4 Precipitation 20 Development Strategies 60

3.5 Calcination 20 8.1 Residue Planning and Design Framework 60 3.6 Power and Steam Generation 20 8.2 Constraints on Forward Planning of Residue Operations 60 3.7 Residue and Waste 21 8.3 Future Residue Planning 60 3.8 Refinery aterW Circuit 21 8.4 Future Development 62

4.0 Bauxite Residue Management 22 8.5 Future Plans with Current Technology 62 8.6 Future Plans with Residue Filtration 67 4.1 Overview 22 4.2 Residue Characteristics 23 9.0 Residue Closure and Rehabilitation 70

4.3 Physical Structure of Storage Areas 23 9.1 Closure Strategy Options 70 4.4 Footprint Design 24 9.2 Current Closure Strategy 71 4.5 Construction of New Residue Facilities 24 9.3 Water Balance/Discharge Management 72 4.6 Bauxite Residue Research and Development Activities 25 9.4 Future Land Use Options and Revegetation 72

5.0 Economic and Social Setting 28 9.5 Closure Funding 73 9.6 Closure Guiding Principles and Alcoa’s Commitments 73 5.1 Description of the Local Community 28 5.2 Overview of Alcoa’s Economic and Social Contribution 30 10.0 Stakeholder Reference Group Guiding Principles 74

5.3 Social Contribution 30 10.1 Summary of Guiding Principles and Alcoa’s Response 74

6.0 Environmental, Heritage and Planning Setting 32 11.0 Glossary 80

6.1 Climate 32 12.0 References 81 6.2 Geology, Soils and Topography 33 6.3 Hydrology 34 6 Pinjarra Long Term Residue Management Strategy Alcoa of Australia Limited 7 Executive Summary

Introduction Purpose of LTRMS This report is designed to enable The Pinjarra Long Term Residue The LTRMS document is designed to stakeholders to review both the longer- Management Strategy (LTRMS) was inform local and state governments, as term strategy and those projects on initially developed in response to a well as the wider community of Alcoa’s the immediate planning horizon. The voluntary commitment to develop long long term management strategies and LTRMS is anticipated to address the key term and closure management plans for commitments for a sustainable future information requirements of the planning residue deposits in line with Ministerial in residue management. In particular and approval mechanisms for the five Conditions applied to the Wagerup Unit it outlines the current short term (5-7 to seven year period to which it relates, Two Expansion in 1990. In order to years), mid-term (25 years) and life-of- so that endorsement of this document keep the LTRMS current it is reviewed mine (2045) management strategies for by the Residue Planning and Liaison and updated on a five yearly basis. This residue at Pinjarra Refinery, including Group (RPLG) and Ministers for State LTRMS represents the fourth published issues such as: Development and Environment ensures Strategy for Alcoa’s Pinjarra Refinery. streamlined approvals processes. • where future residue infrastructure Similarly, endorsement of the 25-year A reference group of key stakeholders areas will be located, and life-of-mine planning footprints is including community members, local • the proposed height requirements designed to provide a basis for approval and state government, and Alcoa for the residue drying areas, and applications required for the longer term. representatives actively participated in the • how environmental risks associated development of the Strategy over a three with residue storage will be managed. The outcomes of this LTRMS will also be month period from June – August 2015. incorporated into the ongoing planning processes for the Pinjarra residue area. The LTRMS document is designed to Consultation and Key Issues inform local and state governments, as The contents of this document are based well as the wider community of Alcoa’s on issues and information discussed during consultation with a Stakeholder long term management strategies and Reference Group (SRG) formed from members of the community, local and commitments for a sustainable future in state government departments and residue management. Alcoa. The purpose of consulting broadly with the community and government stakeholders in the development of the The majority of the document’s content The LTRMS also addresses closure of updated LTRMS was to: reflects presentations to, and outcomes the residue storage area, future land use from, the Stakeholder Reference Group options for the residue storage area after • have stakeholders directly involved (SRG) process, with additional contextual closure and current research into residue in the planning process, information provided as required. management, re-use and revegetation. • ensure that the concerns and It is not intended to duplicate documents queries of the local community, The LTRMS is a reflection of current or processes already in place to address local governments and regulatory knowledge, technology and regulatory current operational management issues. authorities were considered, and standards. The document is not intended These issues are managed via the • ensure Alcoa’s responses to to provide detailed engineering information Environmental Management System (EMS) these issues were transparent for future residue management. and Environmental Improvement Plan (EIP) and documented. processes for the Pinjarra Refinery. 8 Pinjarra Long Term Residue Management Strategy

A summary of the SRG’s deliberations while providing the required open area for Alcoa is currently undertaking the was provided in the form of 30 Guiding drying or storage, defines the minimum comprehensive residue management Principles for Alcoa to consider in the residue footprint that can be achieved. planning processes for the short-term (5 development of the LTRMS. These were year), medium term (25 years), and life developed for environmental and social Alcoa believes that many sustainability of the current mining lease (life-of-mine, issues considered particularly significant by aspects of its residue operations 2045). These planning processes give the group and include: (social, environmental and financial) are consideration to the guidance provided improved by seeking to minimise the final through the LTRMS SRG process. • efficiency of water use, footprint of the residue area. Minimising the potential land area affected by residue Constraints on Forward Planning • management of current or potential can contribute to: Despite the level of effort which goes into surface and groundwater contamination, forward planning, significant changes in • A smaller residue area footprint from direction are occasionally required as a • dust control, which groundwater contamination result of a range of factors, including: could potentially occur, • residue reuse options, • changes in technology, • a reduction in contaminated run- • residue area footprint, height and off water requiring treatment and • changes at the refinery affecting the footprint reduction opportunities, discharge after refinery closure, rate of production,

• land zoning and compatible land use • less surface area requiring • changes in quality of bauxite and/ planning, rehabilitation, and or characteristics of residue material streams (the drying area required • visual amenity, and • greater separation between residue can be affected by small changes and neighbouring properties. in the percentage of mud in the • residue closure and rehabilitation. residue, with higher percentages of The following social and environmental mud requiring a greater drying area), These Guiding Principles, together with aspects of minimising the final footprint Alcoa’s responses, are documented in have potential if not properly managed, • weather conditions, in so far as they Section 10. Details of the current and to be negatively impacted: can affect mud drying rates and future management strategies proposed the construction schedules of new to address these issues are contained • structural stability of a higher residue areas, within the body of the document. residue stack, • input from the community and Residue Footprint Options • visual amenity of a higher residue regulatory agencies while obtaining The ultimate land area used for residue stack, and the necessary statutory approvals storage will be affected by: for new residue areas, • dust emissions associated with • the volume of residue requiring higher wind speeds at increased • internal funding availability, which is storage, stack heights. influenced by a number of factors including the global aluminium • the rate at which residue is A minimised footprint is being sought by market, and produced, research and commercialisation efforts into residue reuse options, as well as • the availability of key equipment and • the residue drying treatment utilised, opportunities to reduce the active drying contractors. and area requirements for residue mud. In addition, the design of the residue stack The plans presented in this LTRMS • the way the residue stack is is optimised wherever possible to ensure are therefore subject to change. The constructed. the most efficient use of land. five yearly review process undertaken for the LTRMS is designed to allow The most significant factor affecting the The SRG members supported this these changes and their impact on final volume of residue requiring storage is approach and design heights of between long term planning for the residue area the availability of alternative uses for residue. 60 metres and 80 metres above ground to be reviewed with community and level for the residue areas. While doing this government stakeholders. In the event The other significant factor affecting the they also encouraged Alcoa to continue that a significant change will impact the size of the final footprint of the residue to investigate alternate technologies and five to seven year plan presented in this area is the stack design. Specifically the processes to reduce the overall footprint. document, additional consultation may height to which the stack can be created, be required. Alcoa of Australia Limited 9

Short-Term Construction Strategy • rezoning, if required, of Alcoa • a reduction in dust potential from Key issues to be managed within the five- owned agricultural land for future residue storage areas, and year time frame are: residue drying and infrastructure requirements, and • reduction of residue storage costs. • maintaining the residue storage and drying capacity to meet the • continued investigations into post Closure Strategy requirements of the refinery, closure water management options. The process of defining the closure strategy will be ongoing, recognising that • maintaining the water storage, surge Life-of-Mine Strategy it will be many years before closure, and capacity, cooling and process water For the purposes of this planning that available technology and community supply functions for the refinery, process, the life-of-mine is considered attitudes at the time may have changed. ensuring they can service the the life of Alcoa’s current bauxite mining increased drying areas, lease, Mineral Lease 1SA (2045). The current closure strategy has three main objectives; that decommissioned • rezoning, if required, of Alcoa owned Alcoa has developed a proposed life- residue areas should have the capability agricultural land for future residue of-mine development envelope. This to be used for productive community storage and drying and infrastructure area reflects the most likely extent for benefit, be safe and self-sustaining in requirements, and development of residue storage within the long-term, and allow future access the current life-of-mine period. The actual to bauxite residue for alternate uses. Key • development and/or commercialisation extent of the area required for storage and considerations at closure relate to the final of strategies to reduce residue associated infrastructure within this period form of the residue area, management of footprint. will be primarily affected by the extent contaminated stormwater, management of developmental constraints identified of leachate and final land use. The current Mid-Term Construction Strategy within the areas to the north and east. closure strategy aims to rehabilitate the Alcoa’s focus for the mid-term strategy The proposed area assumes maximum residue area to allow it to be used for a is to consolidate the existing residue heights within the stack of between 60 range of activities for future generations. area to make more efficient use of the metres and 80 metres above ground level. drying area, improve dust management Ongoing Stakeholder and Community and reduce the risk of groundwater Residue Filtration Engagement and Review Schedule contamination. The mid-term strategy Pinjarra Refinery is currently undertaking The LTRMS will be periodically reviewed. beyond the next five years includes: a feasibility assessment on new The frequency of these reviews is technology for residue storage (residue determined in conjunction with the • implementation or further filtration). The filtration process produces Residue Planning Liaison Group and is development of residue reuse and a dry residue cake by filtering mud slurry currently five yearly. The process of future commercialisation strategies, through a membrane. Residue filtration stakeholder consultation is anticipated to would provide a number of potential be similar to that undertaken in this review. • ensuring the current or expanded benefits including: refinery has timely access to Concluding Remarks adequate storage capacity and • a reduction in water usage, The development of this LTRMS has open drying area, been a constructive means of engaging • a reduction in the future residue the community. Alcoa is very appreciative • ensuring the current or expanded footprint, of the Pinjarra LTRMS Stakeholder refinery can maintain an adequate Reference Group members who provided water balance through access to • impr oved residue dam stability, a considerable amount of personal time adequate water storage facilities, and commitment in working with Alcoa during 2015 to produce this important Strategy for the Pinjarra Refinery. 10 Pinjarra Long Term Residue Management Strategy

Introduction

11.1 Background and site overview 1.2 Purpose of the Long Term Section 3: Overview of Pinjarra In Western Australia, Alcoa owns and Residue Management Strategy Refinery’s operations and the alumina operates alumina refineries at Kwinana, This Long Term Residue Management refining process. Pinjarra and Wagerup, with a combined Strategy (LTRMS) document is designed capacity of approximately 9 million tonnes to inform the local and state government Section 4: Bauxite residue per annum (mtpa), equivalent to 45% and the community of Pinjarra Refinery’s characteristics, design and construction of Australian production and more than long term residue management strategy of storage areas, and current residue 10% of world demand. The company also and associated commitments. The research and development activities. operates the Huntly and Willowdale bauxite contents of this document provide mines in the Darling Range, south of Perth. information on the issues requiring Section 5: Social and economic setting A map of Alcoa’s operations in Western consideration in the management of in which the Pinjarra Refinery operates. Australia is provided in Figure 1-1. bauxite residue and Alcoa’s strategies in relation to future residue facilities. Section 6: Environmental, heritage and Alcoa’s Pinjarra Alumina Refinery is planning setting of the Pinjarra site. located 90 kilometres south of Perth and A reference group of key stakeholders approximately 5 kilometres east-southeast including community members, local Section 7: Environmental management of the township of Pinjarra. The refinery is and state government, and Alcoa strategies for residue storage, changes situated at the foot of the Darling Scarp, in representatives actively participated in in management since the last LTRMS the Peel region of Western Australia, within the development of the LTRMS during review, and management of an the Shire of Murray. The land surrounding a three month period. The majority expanded footprint. the Pinjarra Refinery and residue area is of the document’s content reflects predominantly operated as a beef farming presentations to, and outcomes from, Section 8: Short, medium and life-of-mine enterprise by Alcoa Farmlands. the Stakeholder Reference Group (SRG) residue development strategies, focusing with additional contextual information on major infrastructure requirements and The Pinjarra Refinery commencedprovided as required. projects for each period. operations in 1972 producing 250,000 tonnes of alumina per year. Production The LTRMS is a reflection of current Section 9: Alcoa’s closure strategy and capacity has steadily increased to the knowledge, technology and regulatory future land use options. present level of approximately 4.5 million standards. The document is not intended tonnes per annum. to provide detailed engineering information Section 10: Guiding Principles for residue for future residue management. management as developed through the Bauxite is supplied to the refinery from Pinjarra LTRMS Stakeholder Reference Alcoa’s Huntly Bauxite Mine, located in 1.3 Structure of report Group process. State forest to the east of the refinery. The contents of the key sections of this Alumina produced at Pinjarra Refinery report are outlined below: Section 11: Glossary of terms and units. is transported by rail to Alcoa’s Bunbury and Kwinana shipping terminals and then Section 2: Background and history to Section 12: References. exported to overseas markets or to Alcoa’s the development of the LTRMS and the aluminium smelter in Victoria. The bauxite evolution of the stakeholder engagement is low grade by world standards, requiring process used to support its development. three tonnes of bauxite to produce one tonne of alumina. As a result, large volumes of bauxite residue are generated and stored in bauxite residue storage areas (RSAs) west of the refinery. Alcoa of Australia Limited 11

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Figure 1-1: Location map. 12 Pinjarra Long Term Residue Management Strategy 2Background and history of the LTRMS

Alcoa has had an active 2.1 Initial LTRMS Development The RPLG agreed to the following main As part of the 1989 Consultative elements of the LTRMS: residue management Environmental Review (CER) for the program for over 50 Wagerup Unit Two Expansion, Alcoa • identification of the major years that has focused agreed to develop long term and stakeholders in the planning process closure management plans for residue and a listing of the key issues of on emissions control, deposits in consultation with relevant concern to them, improvement in engineering state government agencies, as well as to submit design reports and monitoring • discussion of the key issues, the management practices and results from the RSAs to the then environmental concerns stemming alternative uses for residue. Water Authority of Western Australia from them, and the current and (WAWA). In March 1990 the Minister recommended future management for the Environment authorised the strategies to address them, proposed expansion, subject to certain conditions including the development of • conceptual plans for the expansion a satisfactory “walk-away solution” for of drying facilities over the 50 year the residue deposits. planning period,

In response to these conditions the • recommendation of a closure RPLG was formed in 1992. The role of strategy for the deposits which the RPLG was to facilitate the planning satisfies, as far as possible, the concerns activity and to review and endorse the of the major stakeholders, and plans developed by Alcoa for submission to the Minister for State Development • analysis of the gaps between the and the Minister for the Environment. The current situation and the desirable RPLG initially included representatives end condition and thereby identify from the Department of Resources and improvement opportunities and Development (chair), Department of research and development needs. Environmental Protection, Water and Rivers Commission, Department of Minerals and In addition, the RPLG agreed on a Energy, Ministry of Planning, Agriculture process and schedule (five yearly) for Western Australia, The Peel Development review of the LTRMS. Alcoa voluntarily Commission, Department of Conservation agreed to extend this process to its and Land Management, and Alcoa. Pinjarra and Kwinana refineries.

In August 1995 an expansion of the Wagerup Refinery was authorised by the Minister for the Environment. The Minister’s statement (Number 390) replaced the earlier 1989 Ministerial Alcoa of Australia Limited 13

conditions with expanded and clarified implementation shall be determined The Pinjarra Refinery LTRMS was conditions related to long term residue on advice from the Minister developed in 1997 as a single document management. These required Alcoa to: responsible for administering the to meet the requirements of both the Alumina Agreement Act), and long term management plan and closure • develop a closure strategy and long strategy for the residue area. In order term management plan for the RSAs • periodically review the long term to complete the closure strategy, a at Wagerup in consultation with the management plans for the residue detailed study was undertaken of the RPLG, to the satisfaction of the deposit in consultation with the residue storage facility requirements to Minister for Environment, RPLG. sustain 50 years of alumina production at the refinery. The primary focus of • report annually on progress towards Although no such conditions have been the original Pinjarra LTRMS (Alcoa, developing the closure strategy, set for the Pinjarra Refinery, Alcoa has 1997) was on detailing the engineering voluntarily committed to meeting these elements of residue planning and closure, • implement the closure strategy conditions for the Pinjarra operations. demonstrating sound environmental to the satisfaction of the Minister management of residue and compliance for Environment (the timing of with legal and corporate requirements. 14 Pinjarra Long Term Residue Management Strategy

2.2 2005 LTRMS Review and feedback on issues raised and, where allow for residue storage and RSA9 was Alcoa initiated a review of the 1997 applicable, provide Guiding Principles constructed in the agreed position on the LTRMS in February 2004 and it was for the company to consider in the east of the stack. published in 2005. During this review development of the Long Term Residue the approach to residue management Management Strategy (LTRMS).” Additionally, in response to Guiding was expanded to embrace stakeholder Principles developed by the SRG, engagement, with local community and The main outcomes of the 2005 LTRMS Alcoa increased its focus on areas stakeholders directly involved in the review included agreement on the: of environmental management of the planning process for the first time. This residue areas, including the management aimed to ensure that the concerns and • 25 year drying area footprint, and monitoring of residue dust. queries of the local community, local government and regulatory authorities, • location of the next green field 2.3 2011 LTRMS Review and Alcoa’s response to these residue storage area (RSA9), and The 2011 LTRMS review addressed issues, were transparent and clearly residue infrastructure requirements for documented. • strategy of minimising the footprint of the life of the mine (2045) as well as the the residue storage area by increasing 25 year footprint requirements and the This was achieved by engaging a the height of the stack, as long as 5-7 year development plan. Stakeholder Reference Group (SRG). visual amenity and dust issues can The role of the SRG was “To assist be appropriately managed. Alcoa in developing a long term strategy for bauxite residue management at the On the basis of this LTRMS, the 25 year Pinjarra Refinery by providing opinions footprint was subsequently rezoned to

Environmental Life Cycle Assessment, Product Design Social Sustainability Consumer Awareness, Suppy Chain Management of Products Economic Economic Value of Products

Environmental Land Management, Biodiversity, Water Conservation Social Sustainability Purchasing Standards, Conservation Investments of Resources Economic Security of Supply, Competitive Pricing

Environmental Climate Change, Energy, Water Material Use, Recycling, Emissions & Waste Social Health, Safety, Our People, Wealth Generation, Sustainability Community, Stakeholder Engagement of Operations Economic Financial Performance, Shareholder Value, Capturing Growth

Figure 2-1: Alcoa’s global sustainability model. Alcoa of Australia Limited 15

Key changes in environmental environmental excellence, and social 2.6 Stakeholder Engagement management and performance since responsibility in partnership with all Alcoa recognises that talking to the 2005 review were also presented; stakeholders. Our objective is to communities, seeking input into plans, however, the focus on routine operational be transparent with respect to our sharing environmental performance environmental issues was reduced in sustainability issues and progress and to and understanding community needs is recognition of the development of the provide significant information to all of our critical to maintaining its social licence Environmental Improvement Plan (EIP) stakeholders. to operate. Consequently a range of process. The EIP process, implemented informal and formal consultation methods in 2006, is designed to address We view sustainability through three are employed by Alcoa to involve and environmental improvement opportunities lenses: inform the community of the company’s for the refinery and residue area. activities. The following section provides 1. Advancing our vision – we strive to an overview of the current consultative 2.4 2016 LTRMS Review achieve a net-positive result between groups in place at Pinjarra and details of The current review of the LTRMS our impacts and the sustainable value the process used to establish the Pinjarra commenced in June 2015 and used an our innovation creates for customers, LTRMS Stakeholder Reference Group. SRG to obtain advice and feedback on consumers and the world. strategy options from local community 2.6.1 Community Consultative representatives, local government and 2. Growing our handprint – creating a Network regulatory authorities. more sustainable world by helping solve Alcoa established a Community some of society’s biggest challenges. Consultative Network (CCN) at Pinjarra The 2016 LTRMS review followed to provide an interactive and open forum a similar format to the 2011 review, 3. Reducing our footprint - efficient use that enables members of the community addressing residue infrastructure of resources and effective control of and Alcoa to freely discuss topics requirements for the life-of-mine (2045), emissions, waste and land use to drive and issues relevant to Pinjarra Refinery the 25 year footprint requirements and improved environmental performance. operations and the community. the 5-7 year development plan; and key changes in environmental management Alcoa integrates sustainability into its core CCN membership is drawn from and performance since the 2011 review. business through targets, roadmaps, and neighbours, community leaders, scorecards. The comparison between environmental groups and local 2.5 Sustainability our impacts (footprint) and the benefits government representatives within the Alcoa’s sustainability objective is reflected that we provide to our customers and region. The CCN meets with Pinjarra in the emphasis of this document. Alcoa’s society (handprints) is what we refer to as Refinery management and representatives approach to residue management is our “net-positive” approach. on a bi-monthly basis with an expectation built on an overarching framework of that information obtained through the CCN sustainability and embraces stakeholder Alcoa was recognised in 2016 for its is then shared with their wider community engagement, with local community and sustainability efforts through inclusion networks. Meeting reports are published stakeholders directly involved in the in the Dow Jones Sustainability North in the local newspaper. planning process. America Index for the 15th consecutive time and in the World Index. Alcoa defines sustainability as using our values to build financial success, 16 Pinjarra Long Term Residue Management Strategy

2.6.2 Environmental Improvement is to establish targets for environmental • community involvement, and Plan (EIP) Consultation improvement and subsequently devise Process actions to achieve those targets. • environmental regulation. EIPs represent Alcoa’s public commitment to continuously improve The EIPs cover areas such as: 2.7 Pinjarra LTRMS Stakeholder environmental performance, reduce Consultation Process environmental impacts and develop • air quality, including greenhouse gas The development of this LTRMS was more sustainable operating practices. and energy efficiency, informed by feedback from the LTRMS EIPs in WA are a voluntary initiative stakeholder consultation process. by Alcoa which, in many cases, go • noise and waste management, beyond the environmental management This process involves formation of an requirements specified in Alcoa’s formal • water conservation, advisory group, with stakeholder groups licence conditions. represented, to work with the company • groundwater management, in their development of the LTRMS. Pinjarra Refinery’s EIPs are developed The independently facilitated group by a working group made up of • land management, including visual works together to provide the company representatives from the local amenity, rehabilitation and fauna/ with a series of ‘Guiding Principles’, or community, local and state government flora management, recommendations, for the company to and Alcoa. The aim of the working group consider in the development of the LTRMS.

The Pinjarra LTRMS SRG is given an opportunity to review the draft LTRMS State Government before it is presented to the Residue Planning Liaison Group (RPLG) for its Local Government comments. Once Alcoa has responded Form Residue to the RPLG comments on the LTRMS, SRG Community Alcoa submits it to the Minister for State Development. Input is then sought from Alcoa the Minister for Environment before the Minister for State Development endorses the Strategy. Stakeholder Reference ALCOA PROJECT TEAM Group Meetings • Operations The LTRMS is intended to address the • Environment key information requirements of the • Research and planning and approval mechanisms for Development the 5-7 year period to which it relates, • Technical Support so that endorsement of this document SRG reviews by the Residue Planning Liaison Draft Long Term Residue Group (RPLG) and Ministers for State Management Strategy Development and Environment ensures (LTRMS) streamlined approvals processes. Similarly, endorsement of the 25 year and life-of-mine planning footprints is Residue Planning designed to provide a basis for rezoning Liason Group (RPLG) applications required for anticipated Government Depts review • Co-ordination of agencies longer term residue infrastructure. Draft LTRMS advice • Endorsement through The stakeholder consultation framework Government Departments for the Pinjarra Refinery LTRMS review is presented schematically in Figure 2-2 and proceeded as follows:

Final LTRMS submitted to 2.7.1 Formation of the Pinjarra Minister for State Minister for Environment Development for endorsement LTRMS Stakeholder Reference Group The Pinjarra LTRMS SRG was formed in Figure 2-2: Framework for SRG participation in LTRMS development. June 2015 and met regularly over a three month period. Alcoa of Australia Limited 17

2.7.1.1 Affiliation Name Community Membership

Community Advertisements inviting community participation were placed in three local Greening Australia (Non Profit Organisation - Environment) Bayden Smith newspapers: the Murray Mail, Mandurah Coastal Times and Pinjarra Murray Times. Community Member Stewart Evans

Community Member Alan Edgar Current members of the CCN were also invited to participate in the LTRMS Local Government consultation process. Three of the members of the Pinjarra Refinery SRG Shire of Murray – Executive Manager Strategic Development Leanne McGuirk were community members. State Government 2.7.1.2 Government Representation Department of Environment Regulation Chris Malley Government representation was sought from a range of agencies and received Department of State Development Phil Knight from the Shire of Murray, the Department Employee of Environment Regulation and the Department of State Development. Pinjarra Residue Employee Peter Hornburg

Alcoa 2.7.1.3 Alcoa Representation WA Operations Residue Manger David Honey Alcoa was represented on the LTRMS SRG by its WA Operations Residue Senior Environmental Scientist, WA Operations – Residue Kathryn Forrest Manager, David Honey, the WA Residue Operations and Maintenance Manager, Residue Operations and Maintenance Manager Matthew Cox Matthew Cox, Pinjarra Refinery Pinjarra Refinery Environmental Manager Anne Price Environmental Manager, Anne Price, WA Operations Residue Senior Environmental Community Relations Officer Fiona Bell Scientist, Kathryn Forrest, Pinjarra Residue Employee, Peter Hornburg and Table 2-1: Pinjarra LTRMS SRG membership. Community Relations Officer, Fiona Bell.

Meeting reports were produced by Kathryn Forrest and Fiona Bell. 18 Pinjarra Long Term Residue Management Strategy

2.7.2 Stakeholder Reference • provide a summary of their 2.7.3 Key Outcomes of the Group Terms of Reference deliberations to be included in the Stakeholder Reference and Operating Procedures development of the LTRMS, and Group Process Independent facilitator, Andrew Huffer, As a result of the process undertaken, was appointed to the Stakeholder • conform to the Terms of Reference 30 Guiding Principles were developed by Reference Group. The initial meeting (TOR) agreed to by the SRG. the SRG over 16 topics. These Guiding of the SRG involved the clarification of Principles have been considered by the group’s role in the LTRMS planning It was agreed to hold meetings every Alcoa and addressed, where possible, process. It was agreed that the week until all issues were resolved. in the Pinjarra LTRMS. The complete responsibilities of the SRG were to: table of Guiding Principles, together with A list of agenda items and a proposed Alcoa’s responses, is provided in Section • consider the long-term planning meeting schedule was developed for the 10. Guiding Principles on individual topics and strategic issues in residue SRG. Issues dealt with at SRG meetings are also referenced throughout the body management in areas such as health, were tabled in meeting reports. Eight of the report, as appropriate. dust suppression, water usage, meetings were held in Pinjarra to address compatible land use, residue reuse the issues raised by the SRG. and impacts on neighbouring land, Table 2-2 contains the meeting schedule • provide advice to Alcoa on factors and topics addressed by the group. that influence long term residue management,

As a result of the process undertaken thirty (30) Guiding Principles have been developed by the SRG over sixteen (16) topics. These Guiding Principles have been considered by Alcoa and addressed, where possible, in the Pinjarra LTRMS. The complete table of Guiding Principles, together with Alcoa’s responses, is provided in Section 10.

Meeting 2.7.4 Consultation Guiding Date Topics Covered No. Principles and Alcoa’s Commitments 1 9 June 2015 Welcome and team formation In response to the information provided, Long term residue management strategy overview the Pinjarra LTRMS SRG developed one Residue management overview Guiding Principle relating specifically to stakeholder engagement. This is 2 16 June 2015 Pinjarra residue storage area tour presented below, together with Alcoa’s 3 23 June 2015 Residue development strategies and future options response.

4 30 June 2015 Environmental management and performance, including: Guiding Principle: 16) Reporting of Dust, odour, water use, surface and groundwater, waste, the Progress of Guiding Principles oxalate and residue reuse Alcoa to report annually to the CCN on its 5 7 July 2015 Environmental management and performance, including: progress against the “Guiding Principles” Rehabilitation research, visual amenity, closure planning developed by the 2015 Pinjarra and final land use options LTRMS SRG.

6 14 July 2015 Guiding Principle development Alcoa’s Response

7 21 July 2015 Guiding Principle development Alcoa accepts and agrees with this principle. 8 4 August 2015 Alcoa’s response to Guiding Principles

Table 2-2: LTRMS SRG meeting schedule. Alcoa of Australia Limited 19 20 Pinjarra Long Term Residue Management Strategy 3Alumina Refining Process

3.1 Overview 3.4 Precipitation The Pinjarra Refinery produces alumina The hot “green” liquor is cooled from from bauxite using the Bayer Process. approximately 100°C to 60-75°C and The process involves four main steps: seed alumina hydrate crystals are added digestion, clarification, precipitationcausing alumina hydrate to crystallise. and calcination. In addition, two other The liquor and hydrate are separated. important activities occur on site; the The hydrate crystals are sized, and generation of power and steam for the crystals of a suitable size are removed. Bayer Process and the storage of bauxite Undersized hydrate crystals are returned residue (the material left over after to the process as seed crystals. alumina is extracted) in impoundment areas known as the RSAs. 3.5 Calcination Sized hydrate is washed and dried, 3.2 Digestion then heated to 1000°C to drive off Bauxite is milled to sand size particles chemically bonded water leaving and hot concentrated caustic soda aluminium oxide (alumina). solution is added making a bauxite slurry. The hot caustic dissolves the available 3.6 Power and Steam Generation alumina within the bauxite. Power and steam requirements for the refinery are met by an onsite power 3.3 Clarification station and a cogeneration facility. The Sand and clay (red mud) are settled out primary fuel supply for the power station leaving an alumina rich “green” liquor. The boilers is natural gas. settled out sand and mud are washed and then pumped out to the residue area. Alcoa of Australia Limited 21

3.7 Residue and Waste Included within the residue complex are mud and sand, and some seepage from The material remaining after the alumina a number of other facilities that support the residue area. Some areas of elevated has been extracted from the bauxite ore the refining operations. These include alkalinity have been identified beneath the is commonly termed “residue”. Residue is ponds designed to cool the plant process residue area which suggest some losses produced at a rate of approximately two dry waters (cooling ponds) and to store occur from historical residue areas (see tonnes per tonne of alumina. This material rainfall run-off water from the refinery site Section 7.9 for further details). Make-up is stored in RSAs adjacent to the refinery. and residue area (run-off water storage water is taken from licensed surface and (ROWS) ponds). The ROWS pond is groundwater sources, including recovery The residue consists of a coarse sand designed to contain the accumulated bores within the refinery in areas identified fraction (often termed “red sand”) and a run-off from a 1:100 wet year so that no to have elevated alkalinity, and the Pinjarra fine silt fraction (often termed “red mud”). contaminated water is released to the townsite waste water treatment plant. The mud and sand streams are pumped environment. Water is recycled back to During years of low rainfall, make-up together to the residue area and separated the refinery via the cooling pond. water may be sourced from the Water in the sand separation building located at Corporation. Onsite sources of make- the residue area. Approximately 50% of 3.8 Refinery aterW Circuit up water include water contained in the the residue stream is sand and 50% is Pinjarra Refinery currently usescaustic soda, rainfall runoff and the refinery mud. The mud density is increased at approximately 3.1 kilolitres (kL) of water sewerage system. All rainfall runoff from the residue area by thickening prior to per tonne of alumina product (annualised the refinery site and RSAs is captured, its final discharge into RSAs. The sand figure). The refinery has been designed stored in lined ponds and recycled back is stockpiled and subsequently used to operate an efficient closed water into the refinery process. for internal construction activities at the circuit, which is supplemented for water residue storage area. losses. Losses of water primarily occur Residue area water management is as steam from the process, evaporation discussed in more detail in Section 7-8. Oxalate, another process by-product, is from water storage areas and residue also stored in approved areas on site. surfaces, water bound within the residue 22 Pinjarra Long Term Residue Management Strategy

Bauxite Residue 4Management

4.1 Overview improvements to the methods of RSA In 1987, Pinjarra Refinery adopted an construction, have provided a sound alternative storage technology termed basis on which the original residue ‘dry stacking’. This process involves management strategies can be updated. pre-thickening the residue and then Alcoa is now able to project, with depositing it in layers which are dried confidence, the facilities required to through solar evaporation. The process sustain the dry stacking operation well is assisted by physically turning over the into the future. mud and produces a high-density, stable stack of residue upon which the next Alcoa commenced commissioning of its mud layer can be placed. first residue filtration facility at Kwinana Refinery in the first half of 2016. The Dry stacking of residue is fully operational filtration facility utilises large scale filter at all three of Alcoa’s Western Australian to force the moisture out of the residue, refineries and this type of storage is leaving behind a dry filter cake. This now being adopted by other minerals filtration process dramatically reduces industries as a best practice. The the required drying time of the residue advantages of this method include: from approximately 100 days to 30 minutes. Residue filtration is expected • a significantly educedr footprint, to provide many potential benefits for residue management including: • reduced environmental risks, such as groundwater impact, and • a reduction in water usage,

• a more stable landform that enables • a reduction in the future residue direct rehabilitation and a wider footprint, range of potential future land uses. • improved residue dam stability, In 1985, Alcoa compiled a detailed report of the proposed residue drying operation • a reduction in dust potential from for the Pinjarra Refinery. This report residue storage areas, and formed the basis for government approval of the changes to residue management. • reduction of residue storage costs.

Operating experience gained at Pinjarra, Kwinana and Wagerup and continual Alcoa of Australia Limited 23

RESIDUE SAND USED FOR DYKE WALL BAUXITE IN CONSTRUCTION Bauxite Residue FLOCCULENT

DILUTE MUD/SAND SLURRY FROM PLANT OVERFLOW RECYCLE ALUMINA REFINING SAND SEPARATION PROCESS MUD Management THICKENER

UNDERFLOW HIGH DENSITY MUD HIGH PRESSURE MUD PUMPING

SUN TO MUD DROPPERS RECYCLE TO VIA MUD LINE PROCESS CLOUD

EVAPORATION DECANT SPRINKLERS

RUNOFF DRY DISPOSAL AREA

UNDER DRAINAGE

Figure 4-1: Coarse particles are separated from fine tailings using cyclones and counter-current wash towers.

Alcoa is currently looking at also (RL 70). The residue footprint expansion solids in the residue (Alcoa, 1997). introducing residue filtration at Pinjarra is planned to the east in the next five Refinery. More information about this can to seven years, and to the north and From an environmental viewpoint, the be found in Chapter 8. east of the current footprint within the alkalinity of the bauxite residue imparted next 35 years. The rate of expansion by the addition of caustic soda and Alcoa believes the bauxite reserve Mineral of the residue area footprint will depend lime that is of most note. Typically, the Lease 1SA will sustain the company’s on the actual production rates over solution entrained with the residue has operations for at least another 50 years. time and the height of the stack. a total alkalinity of between 20 and During this time, it is anticipated that The height of the RSAs will also influence 30 grams per litre (g/L) expressed as alumina production will become more the direction and timing of the footprint sodium carbonate, and a pH of 13. efficient and residue reuse options will expansion; a higher stack height allows Specifically, the alkalinity of the residue assist in reducing the volumes of residue the footprint to be contained to a smaller affects the mud drying rate and the to be stored. For the purposes of this overall footprint. dusting potential of the residue surface. planning process, the life-of-mine is considered the life of the current lease 4.2 Residue Characteristics 4.2.2 Physical Conditions (2045). However given the capacity of Bauxite residue is composed primarily the mine and renewal options on the 4.2.1 Chemical Condition of iron and silica minerals. Residue from bauxite lease, at present the exact date As described in Section 3, bauxite is Darling Range bauxite is characterised of closure and volume of residue requiring crushed, ground and leached with a by a high coarse fraction, due to silica in storage remains uncertain. caustic soda solution during the alumina the bauxite. The coarse fraction can be refining process. The remaining residue considered as a fine to medium grained As at December 2015, the total residue consists of both solids and entrained sand with a specific gravity of 2.9. This storage footprint at Pinjarra, including alkaline solution. During alumina residue sand has proved to be an ideal water storage facilities, was 780 hectares extraction, raw caustic soda solution, material for embankment and road and the maximum residue height was lime and small quantities of chemical construction within the dry stacking 50 metres above natural ground level reagents are added. Side reactions occur operation, as a free draining material which form small quantities of alkaline 24 Pinjarra Long Term Residue Management Strategy

B

Side view A D c

Figure 4-2: Schematic diagram of the dry stacking process.

suitable for surface rehabilitation, and for 4.3.1 Environmental Concerns failure of the outer stack slope. While such the construction of drainage layers at the The main concern relating to the physical a failure might cause short term operational base of the RSAs (Alcoa, 1997). condition of the residue is the potential for problems (such as ruptured pipelines) it embankment failure, which could result should not result in any flow of residue into The fine fraction of the residue, commonly in the release of residue slurry or liquor the surrounding environment. termed ‘red mud’, is silt to clay sized into the surrounding environment. Also material with a specific gravity of 3.2. of possible concern are the more gradual All major embankments are monitored The higher specific gravity of the fine processes of wind and water erosion, regularly to check on their structural fraction results from the relatively high particularly on the sloped embankments condition and visual inspections are iron content. This fine fraction settles of the residue deposits. carried out routinely. In addition, the very slowly and has little strength unless structural integrity of water storage ponds dewatered or dried. When in slurry form, 4.3.2 Current Management and RSA embankments are inspected the fine fraction must be contained within Strategies annually by a third party consultant. approved engineered embankments From the commencement of Alcoa’s (Alcoa,1997). operations in Western Australia, RSAs 4.4 Footprint Design have been designed and constructed in The two main factors affecting the design 4.3 Physical Structure of accordance with accepted engineering of the residue area are the volume of mud Storage Areas standards. Prior to the introduction of to be stored and the open area required A schematic diagram of the dry stacking dry stacking, residue embankments were to dry the mud. process used at Alcoa’s Residue Storage designed as water retaining structures Area is presented in Figure 4-1. in recognition of the need to contain The volume of mud required to be stored the residue leachate, which added depends on the rate and timeframe over The fine tailings are pumped to a conservatism to their design. which residue is produced. The volume thickener vessel where they are settled of a stack is a result of the footprint using flocculent, producing a higher- The introduction of dry stacking of the geometry and the height of the stack. density underflow slurry of around 50% residue has reduced the likelihood of The geometry of the stack (embankments weight for weight (w/w) solids. This slurry the release of residue slurry or liquor to and internal dyke slopes) is influenced is pumped to one of a number of RSAs the surrounding environment, as the red by structural stability and visual amenity where it is placed in layers and allowed to mud is contained initially by residue sand requirements. A lower stack height dry through solar evaporation. embankments and then dried to achieve requires a larger area of land to store the a minimum strength which ensures same volume of mud. To assist the natural drying process, the deposit is stable. The lack of any the surface of the RSAs is mechanically significant volume of free water either Available drying area is a function of turned over using bulldozers and within or on the surface of the deposit, length and width of the open stack, less amphirols. The final dry density of the further decreases the risk of slope failure. the internal areas taken up by dykes and tailings is around 70% solid material. This infrastructure. As the mud elevation in compares to the final density of 60 - 65% The overall stability of the residue storage RSAs increases over time, perimeter solids typically achieved using earlier wet area stacks has been designed in embankments progressively move disposal methods. accordance with international standards to inwards and the net available drying area accommodate both static and earthquake reduces. As a consequence, to maintain The coarse tailings (residue sand) are used loadings. The analysis has been taken the minimum drying area required to for construction of embankment walls, further to demonstrate the mode of failure dry mud it is necessary to periodically drainage layers, rehabilitated surfaces and should it occur under extreme conditions. construct new RSAs. roads within the residue area. A finite element analysis showed the failure to be limited to small horizontal and vertical Figure 4-2 illustrates the process of displacements, rather than a circular slip developing the overall stack. Area A Alcoa of Australia Limited 25

would need to be built and filled before • a containment system to prevent stack to be self- supporting is periodically you can start to build B, and similarly uncontrolled and/or untreated verified through density analysis and Area C would need to be built and filled discharge of contaminated runoff computer generated stability models that before you can create a new area D. from the RSA (note: the existing consider a range of loadings. system is designed to cater for 4.5 Construction of New run-off generated from the residue Residue areas are subject to inspection Residue Facilities system as a whole during both a by an independent consultant every year Prior to the design of a new residue 1:100 wet year, and a 1:100 year to ensure that they are being constructed facility, the area concerned is subject to storm event), and operated correctly. If the independent a detailed site investigation that includes consultant recommends further stability an evaluation of geotechnical and • design and layout to minimise the investigations, stability assessments are hydrogeological conditions. A preliminary risk and impact of spillage from carried out using a cone penetrometer design report is prepared for each new pipelines and pumping systems (CPT) which gives a profile of material residue area 6 to 12 months prior to the including primary and secondary strength by measuring the resistance commencement of construction and spillage containment structures at generated by forcing a probe through the forms the basis for government agency high risk areas, and residue stack. The results are then used review and environmental approval. as input into a stability software program • embankment design to ensure which calculates a factor of safety for the The RSAs are designed in accordance long term stability against slippage stack configuration. If stability issues are with the applicable edition of the and erosion including thorough suspected, detailed geotechnical studies ‘Tailings Management’ issued by the assessment of the risks and are carried out and corrective actions Australian Government Department of effects of dynamic loads such as are implemented to ensure ongoing Industry, Tourism and Resources, and earthquakes. Factors of safety are adequate stability. guidelines produced by the International adopted in accordance with the Commission on Large Dams (ICOLD) and guidelines. 4.6 Bauxite Residue Research the Australian National Committee on and Development Activities Large Dams (ANCOLD). These guidelines Subsequent lifting of embankment 4.6.1 Overview include design criteria for earthquake walls is completed using an upstream Development of alternative uses for risk, long term stability and management embankment methodology and is bauxite residue has been one of the major of storm events. subject to rigorous design criteria. objectives of Alcoa’s residue research This ensures stability both during program since 1978. By identifying and In addition, Alcoa has mandated standard construction and in the long term. The demonstrating a range of technically and internal design guidelines for all new RSAs ultimate ability of the overall residue economically feasible alternative uses, in Western Australia to ensure the risk of ground and surface water contamination is minimised. These standards require all new residue areas to have:

• a constructed low permeability base and embankment seal that is at equivalent to approximately 0.45 metres depth of mechanically compacted clay with a hydraulic conductivity of less than 10-9 m/s, with a synthetic geomembrane (HDPE) placed directly on top of the clay seal,

• a base drainage system which reduces the hydrostatic pressure on the seal above the ‘composite liner’ referred to above,

• monitoring systems to indicate leakage or spillage outside of the containment system, 26 Pinjarra Long Term Residue Management Strategy

bauxite residue may become a resource retention properties compared to local 4. An independent peer review rather than a waste. The company also sands. Red SandTM has also been of the Red SandTM project recognises that if significant reuse can assessed as a growth medium for turf has been conducted by be achieved, the rate of expansion of the production, as a top dressing soil for KMH Environmental. The RSAs can be slowed, and the long term golf courses, as a bunker sand for golf peer review process was impacts of residue storage can be reduced. courses, for concrete production and as commissioned to identify a general fill material for land reclamation. any potential risk associated 4.6.2 Reuse Strategies with use of Red SandTM, Bauxite residue is comprised of two main The technology to produce Red SandTM review these risks against the fractions that are treated to produce two has been demonstrated through a pilot technical assessments and distinct products. The coarse fraction plant operated at Alcoa’s Wagerup specialist investigations already (>150 μm) can be treated to produce a Refinery with the sand produced from conducted on Red SandTM, material known as Red Sand™ and the this plant used by the Department of and identify any technical fine component (<150 μm) into a material Main Roads in a road construction trial gaps and recommendations known as Red Mud™ or Alkaloam®. on Greenlands Road (Pinjarra, Western for further work. The review Australia), and by Fairbridge Village concluded that Alcoa has A number of opportunities for residue (Pinjarra, Western Australia) to top- taken an expansive approach re-use continue to be investigated dress its main oval. The pilot plant has to evaluating and assessing as part of Alcoa’s research and also been operated at Alcoa’s Kwinana the Red SandTM material. No development program based at Kwinana. Refinery with the sand produced being significant gaps were identified Alcoa’s primary focus is currently on used to top-dress the Alcoa Social Club in the review. commercialisation of Red SandTM. oval, a series of trials with various golf clubs, and an industrial land development One of the major hurdles for the use Alkaloam® trial in conjunction with Landcorp. and commercialisation of Red Sand™ Further opportunities for re-use of has been the lack of a clear regulatory Alkaloam® have been put on hold until Various health and risk assessments approval process within Western Red SandTM has been formally approved have been conducted on Red SandTM to Australia. In December 2014, the by the Department of Environment ensure its safe utilisation. These include: Department of Environment Regulation Regulation (DER) for re-use following (DER) released guidelines for the use of assessment under the Waste Derived 1. A radiological assessment waste derived materials (WDM). These Materials framework. In the interim, which has resulted in approval guidelines provide a pathway for the an extensive leaching assessment on by the Radiological Council of removal of the waste classification of Alkaloam® is underway at the Chemistry Australia for road construction WDM’s to facilitate their reuse. Alcoa Centre of Western Australia as a pre- and top dressing. has conducted the necessary risk requisite for submitting an application to assessment required as part of the the DER to have the material assessed as 2. A health risk assessment which guidelines resulting in the development a Waste Derived Material for re-use. has been reviewed by the a set of material specifications based on Department of Health, resulting soil and water quality limits endorsed by Reuse of Red Sand™ in their endorsement of Red the DER. Alcoa submitted an application Alcoa’s residue sand is currently used for SandTM for top dressing, road for the reuse of Red Sand™ to the DER the construction of RSAs, with excess construction, and industrial in June 2016 and is awaiting a response. being stored within the RSAs. Alcoa land development. has developed a process to wash and Alcoa has also led the implementation carbonate the sand so that it can be 3. An independent technical of leaching test methods developed in considered for use as a building and assessment, conducted by the European Union by the ECN into construction material. The resulting the Energy Research Centre Western Australia, which has now been product is known as Red SandTM. of the Netherlands (ECN), has endorsed by the DER and referenced been undertaken to assess in their WDM guidelines as a part of It is proposed that Red SandTM be used in Red SandTM against the Dutch their risk assessment process. Under a a number of applications which has been Building Material Decree, a joint project with the Minerals Research trialled and proven to perform equal to or well-established set of criteria Institute of Western Australia (MRIWA), better than virgin sand materials. These that are well referenced and the Chemistry Centre of WA and other include top dressing of turf for recreational used widely. The review did not industry sponsors, these leaching uses, road construction, and industrial identify any issues with the use methods are currently being developed, land development. Red SandTM is well of Red SandTM in construction applied and validated in WA. structured and has improved phosphate works within their framework. Alcoa of Australia Limited 27

4.6.3 Residue Reuse Guiding Principles and Alcoa’s Commitments In response to the information provided, the Pinjarra LTRMS SRG developed two Guiding Principles related to alternate uses for residue. These are presented below, together with Alcoa’s response.

Guiding Principle: 2a) Residue Reuse - Priority The SRG encourages Alcoa to continue with its efforts to have government develop a simplified approvals process and legislative framework that will enable residue re-use products to go to market on a commercial basis.

Alcoa’s Response Alcoa accepts and agrees with this principle. Our initial focus is on gaining approval for reuse of the sand fraction of the residue. Once sand is being successfully marketed, we will focus on gaining approval for reuse of the mud fraction of the residue.

Guiding Principle: 2b) Residue Reuse - Reporting Alcoa to report to the CCN annually on the status of research into residue re- use, including the status of any approvals required for its use.

Alcoa’s Response Alcoa accepts and agrees with this principle. 28 Pinjarra Long Term Residue Management Strategy Economic and 5 Social Setting 5.1 Description of the Local Despite proximity to these urban centres, During the period 2003 – 2013, the Community the Shire of Murray is predominantly highest population growth area in The Pinjarra Refinery is locatedsemi-rural. The smaller town of North the Peel Region was the Serpentine- approximately 5 kilometres east- Pinjarra is located approximately Jarrahdale Shire (5.7%), followed by the southeast of the township of Pinjarra, 2.5 kilometres northeast of Pinjarra. Shire of Murray (3.5%) and the City of within the Shire of Murray and the Mandurah (4.5%). The Shire of Murray broader Peel Region. Pinjarra is located Peel is the fastest growing region in currently makes up 13% of the Peel on the banks of the Murray River and Western Australia, the estimated resident region’s population. situated on the South Western Highway population of the Peel Region was approximately 86 kilometres south of 124,500 in 2013, accounting for five per Perth and 20 kilometres from the coastal cent of Western’s Australia’s population. centres of Mandurah and Rockingham.

Alcoa of Australia Limited 29

Alcoa plays a critical role in sustaining Hallam (1975) states that in pre- Different Aboriginal groups in the South the Peel Region’s workforce as a settlement times, Aborigines maintained West Region had their own myths and major employer in the region and a the Swan Coastal Plain as open forest Dreaming stories, which were specific contributor to the Peel Region’s Gross and grassland through repeated and to the tracts of land that they inhabited. Regional Product. An overview of Alcoa’s deliberate burning. The forest habitat However, members of adjoining economic and social contribution to provided for a variety of mammals, and groups intermarried, traded, passed Australia and the Peel Region is provided the grassland provided for pastures on information, held joint religious in Section 5.3. for kangaroos as well as facilitating the ceremonies and had other festivities movement of people. (Berndt, 1979; de Gand, 1999). 5.1.1 Aboriginal Community The Aboriginal people of the South Because of the abundance of food Aboriginal people believed that the West region are a rich component of the resources on the Pinjarra Plain and the actions of Ancestral Beings created all society in and around Pinjarra. In 2011, absolute dependence of Aboriginal life forms as known today including tribal the Australian Bureau of Statistics census people upon the land and its resources, territories and languages. All living things reported approximately 2600 aboriginal a substantial Aboriginal population was therefore shared a life force that stemmed Australians lived in the Peel region. maintained in the region. from the Dreaming. Individual Aboriginal people were close to particular animals or In 2000, Alcoa commissioned a report Bindjareb Nyungar people (Berndt, 1980) plants because they shared this life force describing the Aboriginal people of historically populated the region of the and regarded these animals or plants as Pinjarra. The report took 12 months to Swan Coastal Plain, on which the Pinjarra soul brothers or sisters. Affinities with the produce and is now held in the Battye Refinery is located. Family groups who plant or animal world were expressed in Library. This comprehensive work belonged to the Bindjareb Nyungar daily life as well as ritually. For example, describes the history of the region and were further defined by the location of an individual would not eat the plant or the genealogies of nine of the most their home territory. For example, the the flesh of the animal they shared this prominent Aboriginal families and elders Darbalung were the people that occupied form of kinship with. However, on ritual of today. the estuary (Mandurah), Buyun-gur were occasions they would consume their the people that occupied the hills and the totem in order to demonstrate affinity This work was conducted in parallel with ‘river people’ were called Bilgur (beel or with it. an archaeological and ethnographical bil meaning ‘river’) (Bates, 1985). review of the land surrounding the refinery Other specific affinities to the Nyungar and residue area. Results of heritage site As the Swan Coastal Plain was so individual could be specific localities surveys are discussed in Section 6.6.1. abundant in food resources, the Nyungar in the person’s tribal territory where people came to the area on a yearly basis significant events had taken place, and/ In 2004, Alcoa commissioned an in February, from the surrounding regions or totems that were associated with Ethnographic Report on an Aboriginal such as Brookton, Pingelly, Bunbury, Collie religious categories and were part of the Community Consultation Project (de and Perth, to harvest, fish and attend progression in the religious knowledge Gand, 2004) to ensure that appropriate meetings (Contos, 1998). This information that correlated with progressive initiations. elders of the Aboriginal community was confirmed by Joe Walley who stated in Pinjarra were consulted regarding that “People came through Oakley Brook This rich culture and background potential impacts associated with from Brookton, Beverley and Pingelly provides the foundation for the Aboriginal the Pinjarra operations. The process on their way west to Mandurah” (Joe people in Pinjarra today. concluded that Alcoa is communicating Walley, pers. comm.). Places where other with the appropriate elders and such meetings were held were Burugup, confirmed the processes of consultation Mandurah and Pinjarra. into the future. The following comments have been extracted from the report and provide an insight into the Aboriginal communities in the Pinjarra region. 30 Pinjarra Long Term Residue Management Strategy

5.2 Overview of Alcoa’s 5.2.2 Meeting Global Demand Economic and Social During the past 50 years Alcoa has grown Contribution into one of Australia’s major mineral exporters. Alcoa of Australia Limited 5.2.1 Economic Contribution operates the largest integrated bauxite, Alcoa contributes to the economy directly alumina refining and aluminium smelting through spending on goods and services system in the world. and by paying salaries and wages to its workforce. Alcoa also contributes The Pinjarra Refinery is currently one indirectly through flow-on spending. Each of the world’s most efficient alumina year, Alcoa contributes more than AUD refineries. In order to maintain its global $2 billion to the WA economy through competitiveness, Alcoa is pursuing wages and salaries, taxes and royalties, ways to further improve efficiencies and the purchase of goods and services. and increase production to meet global demand at its existing operations, as well The Pinjarra Refinery is a major regional as investigating potential new projects. employer with approximately 1000 employees. Alcoa encourages local 5.3 Social Contribution suppliers to conduct business with the The Pinjarra Refineryprovides company and the refinery. It invites local partnerships and sponsorships to business to bid on locally supplied or community organisations in a range of manufactured goods or services and gives fields and capacities. Recent partnerships preference to local business in a competitive in the region have assisted with situation. Alcoa also works with local improvements to the Community Centre, business groups to identify and utilise local the Murray Regional Equestrian Centre, suppliers and where possible, structures Murray Leisure Centre Clubrooms, bids to enable local supplier participation. Cantwell Park and Kingfisher Park.

During the past 50 years Alcoa has grown into one of Australia’s major mineral/energy exporters. Alcoa of Australia Limited operates the largest integrated bauxite, alumina refining and aluminium smelting system in the world. Alcoa of Australia Limited 31 32 Pinjarra Long Term Residue Management Strategy

Environmental, Heritage 6 and Planning Setting

Understanding the 6.1 Climate 6.1.3 Wind environmental, heritage and Pinjarra has a Mediterranean type climate Winds at Pinjarra are controlled by characterised by warm, dry summers and synoptic weather patterns, local features planning setting of the Pinjarra mild, wet winters. Detailed climatic data is such as the topography, and sea and residue area provides a available from the Bureau of Meteorology land breezes. Pinjarra Refinery is located monitoring location in Pinjarra town and at the base of the Darling Scarp. This context for the environmental Alcoa’s weather station. topographic feature: aspects associated with the 6.1.1 Temperature and Humidity operations. The following • generates very strong easterly Pinjarra temperatures are characteristic “foothill” winds (up to a factor of two section provides an overview of the South West region of Western or more times higher than elsewhere of the physical and cultural Australia and are similar to those on the coastal plain) that are typically recorded in Perth. The warmest months experienced during the summer setting of Alcoa’s Pinjarra at Pinjarra are January and February, months from early evening to several Refinery operations. when maximum temperatures average hours after sunrise, over 30 degrees and can exceed 40 degrees. The coldest months are • creates rotars or reversals near the July and August, when the maximum foothills during easterly winds, temperature is around 17 degrees. • channel or deflect westerly winds up Humidity at Pinjarra generally peaks in the the escarpment, and early mornings and drops during the day. Humidity is higher in winter than summer. • create katabatic flows down the escarpment. 6.1.2 Rainfall Pinjarra has been experiencing a The most pronounced of these localised significant decreasing annual rainfall effects is the generation of very strong trend since the late 1960s and this easterly winds, up to a factor of two times decrease has further accelerated since higher than elsewhere on the Coastal 1993. Average annual rainfall over the Plain. These winds can extend up to last decade (2006 to 2015) was 706 mm. eight kilometres west of the escarpment Approximately 80% of the total annual but are usually more localised. rainfall is recorded between April and September. The average annual rainfall In summer, the predominant winds are recorded at the Pinjarra Post Office has moderate to strong east-southeasterly decreased markedly since the 1970s. winds and moderate southwesterly This trend is consistent across the south- winds. The strong southeasterlies are west of Western Australia. The change to the result of the frequent synoptic a lower rainfall regime in the late-1960s easterlies at this time of the year and the shows a reduction of 166 mm from 996 development of accelerated flows down mm in the period 1917 to 1968 to 830 the escarpment. The southwesterly mm in the period 1969 to 2014. winds are associated with development of the sea breeze. For the winter months, the winds are predominantly north- northeasterly, due to prevailing synoptic patterns and katabatic winds. Alcoa of Australia Limited 33

6.2 Geology, Soils and as the Yilgarn Craton. The Yilgarn Craton The topography and underlying geology Topography is characterised by outcropping granites on the site influence the patterns of The geology of an area has a large effect and deep lateritic soils, which are some development, with the most heavily on the shape of the land and the type of of the oldest in the world. developed areas being flat, cleared soil that is formed. The land surrounding regions of the Coastal Plain. Undeveloped the Pinjarra Refinery lies at elevations The refinery and residue areas are areas lie in inaccessible parts of the between 25 metres and 50 metres above underlain by geological formations that escarpment or poorly drained locations. mean sea level (AMSL). The land slopes are not laterally continuous. The upper gently to the west and rises to 75 metres section of the Leederville Formation is It is also important to note that the AMSL in the foothills of the Darling Range, composed of silts, clays, siltstones and South West region of Western Australia and up to 200-300 metres AMSL on top silty or clayey sands. is of particular interest to seismologists of the scarp, east of the refinery. Figure 6 as there is an apparent concentration -1 illustrates the geology of the area. The Leederville Formation is found at a of earthquakes in the area. This area, depth of approximately 20-30 metres and roughly between Geraldton and Albany, The Pinjarra Refinery and residue area extends to about 120 metres beneath the is known as the South West Seismic are located next to a boundary between residue facilities. The Cattamarra Coal Zone. The zone exists on the Yilgarn two geological regions: the Swan Coastal Measures then extend to a greater depth Craton and runs in a northwest- Plain and the Yilgarn Craton. The Swan and are characterised by sandstone, southeast direction inland from the Coastal Plain is generally flat with siltstone, shale and some minor coal. Darling Escarpment (although the exact gentle undulations and predominantly This underlying geology is covered by boundaries of the zone are still imprecise) comprises sedimentary material which, a relatively shallow superficial formation (Seismicity WA, 2004). In accordance geologically speaking, is quite young. comprising clay, clayey sand and sand with the West Australian Department of East of the Alcoa site, the Darling (with the Guildford Clay and the Yoganup Mines and Petroleum Tailings Storage Escarpment rises abruptly to a height of Formation being the most dominant) up facilities code of practice, design criteria around 300 metres. This area is known to 20 metres thick. for RSAs account for earthquake risk and long term stability.

Figure 6-1: Perspective view showing schematic geological section. 34 Pinjarra Long Term Residue Management Strategy

6.3 Hydrology The low permeability clays form an Cattamarra Coal Measures are part of important barrier to vertical and horizontal the Cockleshell Gully Formation, which 6.3.1 Groundwater groundwater flow. Pathways for local extends from Rockingham in the north to The Pinjarra site lies at the eastern groundwater movement are nonetheless Kemerton in the south. edge of the Perth Basin, the major provided by the presence of sandy zones, groundwater feature of the Swan dissected clays and lateritic intrusions. The The superficial aquifer has limited Coastal Plain. The Perth Basin extends Guildford Clays are underlain by sands and groundwater supply potential. Recharge from north of Geraldton to the lower clayey sands in the Yoganup Formation. is predominantly by infiltration of rainfall southwest of Western Australia. The and groundwater discharges as base- Perth Basin comprises several aquifers, Beneath the Yoganup Formation lies the flow to the surface drainage. Near many of which are important sources of Leederville Formation. The upper section the residue area, the top part of the groundwater. Shallow aquifers include of the Leederville Formation comprises superficial formation is dominated by the superficial formations (lying near the gravelly silts, clays, siltstones and silty the Guildford Clay formation. The low surface of the soil) and the Leederville or clayey sands. A layer of dark silty permeability clays of this formation Formation, which is found at a depth clay or shale often identifies the top of form an important barrier to vertical and of approximately 20-30 metres, and the Leederville Formation, and forms horizontal groundwater flow. reaches a thickness of up to 650 metres. an effective hydraulic barrier. In some A major aquifer, known as the Yaragadee locations, however, this layer is not There is little evidence of discernible Formation, underlies the majority of the present and the Yoganup and upper alteration of groundwater conditions Perth Basin. The Yaragadee aquifer is Leederville Formations are hydraulically beyond the boundaries of the residue extremely deep (up to 3000 metres) and continuous (PPK, 2002). area due to contaminant migration. There old (with groundwater of tens to hundreds is some evidence of localised alteration of thousands of years age). The major aquifer underlying the of groundwater conditions in the shallow Leederville Formation is the Yarragadee, Leederville Formation directly under the Near the residue areas, the Guildford which is replaced in the Pinjarra region residue area. Clays dominate the shallow soil type. by the Cattamarra Coal Measures. The Alcoa of Australia Limited 35

6.3.2 Surface Hydrology The two creek lines directly associated Pumpback Dam, which are designed Regional surface hydrology is strongly with the refinery and residue area are to hold surge following rainfall events. determined by the underlying geology Oakley Brook to the south and Barritt Overflow from these dams continues and regional topography. The Murray Brook to the north. During construction on its original course. The overflow from River is the major drainage pathway for of the refinery and residue area, surface Barritt Brook was redirected around the the region, and is fed by sub-catchments water dams were created for both brooks northern boundary of the residue area draining the foothills. The Murray with the water being used for refinery and in 1996 redirected into an Alcoa River ultimately drains into the Peel- purposes. Alcoa has two structures created clay borrow pit. Harvey Estuary. Surface flows ultimately at Oakley Brook; the Oakley Brook discharge into the Murray River. Detention Dam and the Lower Oakley

Figure 6-2: Surface water and catchment map. 36 Pinjarra Long Term Residue Management Strategy

6.4 Flora 6.5 Fauna 6.6 Heritage The vegetation surrounding the Pinjarra Prior to construction of the refinery, the Refinery was cleared many years before presence of native fauna at the Pinjarra 6.6.1 Aboriginal Heritage Sites the construction of the refinery and the site was limited. Species diversity and Surveys of heritage sites are carried land used for cattle grazing. populations were consistent with those out prior to any proposed changes to expected on agricultural grazing lands. A the refinery footprint. These surveys are As the Pinjarra Plain unit contains the best land management program has been in conducted according to the Guidelines soils for pasture development and irrigation, place since 1992 which has focused on for Aboriginal Heritage Assessment there is no virgin vegetation left. Relict revegetating large areas surrounding the released by the Minister for Aboriginal wooded areas would have been selectively Pinjarra Refinery and residue area. Affairs in October 1993 and involve the culled for timber during the earlier years local Aboriginal people. of settlement and their original shrub and In 1994, Alcoa commissioned a vertebrate ground layers have been replaced by fauna survey of farmland and wetlands Horizon Heritage Management was pasture plants (Beard 1990). surrounding the Pinjarra Refinery. The engaged by Alcoa in September 2012 survey had two purposes: to undertake an ethnographic site Since 1992 substantial revegetation identification survey for the Pinjarra work has been conducted within the • To obtain accurate baseline data Farmlands. The survey was undertaken refinery site, with a focus on establishing so that the needs of fauna could be with members of both the Bilya native vegetation corridors, primarily taken into account in rehabilitation and Noongar Organisation and the Winjan along natural watercourses and roads. habitat management programs, and Corporation. No new ethnographic sites Comprehensive reviews of vegetation were identified under Section 5 of the are conducted to evaluate changes over • To record the distribution and Aboriginal Heritage Act 1972, however, time. These surveys have identified one abundance of fauna so that the the continuing existence of two registered species, Synaphea stenobola, that is success of fauna management sites was confirmed during the survey. on the Department of Parks and Wildlife could be evaluated. (DPaW) declared rare flora species list. Given the presence of heritage sites within A protection program to safeguard In 2002, 2005, 2008 and 2012 Pinjarra Farmlands, Alcoa will actively this species has been established in follow-up surveys were conducted. work with the local Aboriginal people and consultation with DPaW. These were designed to assess changes the DIA to ensure compliance with all in the fauna populations over time, and heritage conservation requirements and A level 2 flora and vegetation assessment develop recommendations for ongoing protection of aboriginal heritage sites. was undertaken in December 2012 management of fauna. by Mattiske over the areas of remnant 6.6.2 European Heritage Sites bush land surrounding Pinjarra Refinery. Alcoa engaged Environmental While some European heritage sites In general, the condition of remnant Management Services (EMS) in 2012 to are protected near the Jarrahdale and vegetation surveyed during this survey undertake a level two fauna survey of the Huntly mines, the closest protected site was very good. There was little evidence Pinjarra Refinery landholdings. This survey to the Pinjarra Refinery is an airstrip just of other forms of disturbance, such as identified no new species for the coastal/ over one kilometre to the north of the grazing, in the majority of remnant sites. scarp area. The survey comprised of 659 residue area. This airstrip was used by A total of 235 vascular plant taxa which fauna captures consisting of 65 species. a squadron of Beaufort Bomber aircraft are representative of 125 plant genera crews during World War II. and 47 plant families were recorded The study identified four conservation within the quadrats. The relatively high significant fauna species occurring in the The Fairbridge Farm School is also species richness still reflects the diversity Pinjarra farmlands, including Carnaby’s located within Alcoa’s landholdings. The of habitats founds in the area. The Cockatoo, Chuditch, Southern Brown Farm School was established at the site majority of recorded taxa are widespread Bandicoot and Rainbow Bee-eater. in 1921 and closed in 1981. In 1993, throughout the region. Fairbridge began a re-development The significance of the Pinjarra Refinery program. Funding has come in the site for fauna appears to be strongly form of grants from both the Australian linked to the revegetated areas, Ridge and Western Australian Governments, Hill Shelf vegetation and the jarrah forest sponsorship by corporations, including to the east (Environ, 2003). Alcoa, and by private donations.

All 50 buildings within Fairbridge are heritage listed, including the Chapel of the Holy Innocents and Fairbridge House. Alcoa of Australia Limited 37

Figure 6-3: Pinjarra Refinery land ownership and surrounding development proposals.

6.7 Existing Land Use and Tenure portion of Alcoa’s landholdings are zoned of the residue area and is owned and Alcoa’s landholdings include the land “industrial” to allow for operation of the operated by the Water Corporation of WA. required for residue storage, refinery refinery and storage of residue, and activities and surrounding farmlands. The “Special Use - Refinery Water storage and The majority of property surrounding extent of Alcoa’s land holdings are shown incidental infrastructure and equipment Alcoa’s site is privately owned. Historically in pink on Figure 6-3. associated with the alumina refinery with the majority of surrounding landholdings the exclusion of Residue Storage Areas”. have been zoned rural and used for Alcoa’s original Pinjarra RefineryThe zoning boundaries are illustrated in agricultural purposes. However, in the landholdings were purchased under a State Figure 8-1. Further industrial rezoning recent past there has been increased Agreement Act to allow for future residue of Alcoa’s rural landholdings may be interest in the development of surrounding storage areas and refinery infrastructure, required to allow expansion of the current land for a variety of uses, such as rural and to provide some separation between residue storage area and associated residential, special use – equestrian, the refinery operations and neighbouring infrastructure. The long term expansion and urban. A summary of current land communities. Land not currently required of the residue area is planned entirely on developments and proposals is shown for operational use is put to productive use Alcoa owned land. on Figure 6-3. as Alcoa Farmlands. There has not been any requirement for Alcoa to purchase a Section 8 outlines Alcoa’s long term This changing situation has highlighted ‘buffer’ and none has ever been defined or development envelope and the strategy for to Alcoa, local and state planning incorporated in planning documents. its incorporation into State planning policies. authorities, the need to clarify Alcoa’s long term development intentions so that A portion of the land to the north of the The bulk of Crown Land adjacent to the Alcoa’s operations can be considered by main refinery site contains Fairbridge Pinjarra site is on the face of the Darling the relevant government agencies when Village. Fairbridge Village is used for Escarpment. This land is State forest and assessing development applications for holiday accommodation, training, is administered by the Department of neighbouring properties. conventions and conferences, however, Parks and Wildlife (DPaW). A wastewater several of the Fairbridge Cottages are treatment plant, which serves the Pinjarra permanently occupied. Currently, a township, is located immediately west 38 Pinjarra Long Term Residue Management Strategy

6.8 Local, Regional and State The State Planning Strategy 2050 guides Pinjarra Refinery industrial area is referred Planning Policies and Visions and informs: to in the Strategic Industry section, and the The development of the LTRMS and final proposed future residue areas are shown land use planning objectives are informed • local community plans, growth plans as an “Industrial Investigation” area. by current planning policies and visions and local planning schemes and for the region by the Western Australian strategies with structure planning 6.8.2 State Planning Policies Planning Commission, the Shire of Murray and development assessments, and the Peel Development Commission. SPP4.1 • project approvals through the State Planning Policy 4.1: State Industrial The need for Alcoa to continue to Government’s Lead Agency Buffer Policy (SPP4.1) was adopted in work with planning agencies to ensure Framework, 1997 to provide a consistent Statewide long term development objectives for approach for the protection and long- Alcoa’s landholdings are understood • planning for the coordination term security of industrial zones, transport and included in appropriate planning of physical and community terminals (including ports), other utilities instruments was identified in the LTRMS infrastructure, and special uses. SRG meetings. • region scheme amendments, SPP4.1 notes that industry and Together with a commitment to best regional planning and infrastructure infrastructure, by their very nature, practice environmental controls, frameworks, regional investments may generate a range of emissions of compatible land use planning is and service delivery programs, and pollutants including noise, dust, gas, considered necessary to prevent conflict odour, fumes, lighting overspill as well as from encroachment of conflicting land • investment proposals into areas risk levels which may not be compatible uses. Compatible development does not and sectors of the State most likely with other land uses. As a result, most seek to quarantine land from development, to generate a return in the public industries and infrastructure as well as but to ensure the development is interest. some other uses need to be separated appropriate in order to protect the from residential areas and other sensitive interests of potential neighbours, Alcoa’s Directions 2031 and Beyond uses with a buffer area to ensure that employees and shareholders, local Directions 2031 and Beyond is the highest amenity (environmental quality, health contractors and businesses, and local level spatial framework and strategic and safety standards) is maintained at and state government agencies who field plan for the metropolitan Perth and Peel acceptable levels. and investigate any complaints. Region. One of its purposes is to set the framework for urban development until The specific objectives of SPP4.1 are: 6.8.1 State Planning Strategies and 2031 and beyond. Structure Plans • To provide a consistent State wide Draft Perth and [email protected] approach for the definition and State Planning Strategy 2050 The Draft Perth and [email protected] securing of buffer areas around The State Planning Strategy provides strategic suite of documents provide industry, infrastructure and some the strategic context for planning and guidance on sustainable development special uses. development decisions throughout over the next three decades to ensure Western Australia. It is based on a the impact of urban growth on areas of • To protect industry, infrastructure and framework of planning principles, environmental significance is minimised, special uses from the encroachment strategic goals and State strategic to protect heritage, and to maximise the of incompatible land uses. directions that respond to the challenges benefits of available land and existing and opportunities that drivers of change infrastructure. The Draft Perth and • To provide for the safety and amenity present for the future land-use planning [email protected] has four planning and of land uses surrounding industry, and development of Western Australia. infrastructure frameworks for the Central, infrastructure and special uses. North-West, North-East and South The Strategy supports a collaborative Metropolitan Peel sub-regions. • To recognise the interests of existing approach to planning for the State’s landowners within buffer areas who land availability, physical and social Draft South Metropolitan Peel Sub- may be affected by residual emissions infrastructure, environment, economic Regional Planning Framework and risks, as well as the interests, development and security. The Draft South Metropolitan Peel Sub- needs and economic benefits of Regional Planning Framework (SMPSPF) existing industry and infrastructure was released for public comment in 2015. which may be affected by encroaching The draft SMPSPF identified proposed incompatible land uses. industrial investigation areas for the proposed residual storage areas. The Alcoa of Australia Limited 39

6.8.3 Regional Scheme These principles collectively form the Rural Planning Precinct Plan’s objectives, Peel Regional Scheme which include: The Peel Region Scheme (PRS) is the principal land-use planning instrument for • Protect the regionally and locally the Peel Region and allocates all land in significant scenic qualities of the the Peel Region into zones and reserves. Darling Scarp; Region planning schemes are designed to guide land-use planning in the long • Protect important areas of remnant term through the use of broad zones and vegetation; reservations, intended to minimise land use conflicts. • Protect productive agricultural land within the study area from land uses The Peel Region Scheme sets out the and development that lead to its following purposes and aims: alienation or diminished productivity; and • Provision for the zoning of land for living, working and rural land uses; • To inform long term strategic planning projects for the Shire of • Identification and protection of land Murray. having strategic importance for industrial and future urban use; 6.8.5 Local Planning Scheme Town Planning Scheme 4 (TPS4) • Promotion of the sustainable Town Planning Scheme 4 (TPS4) is the development of land taking into local planning scheme applicable to the account relevant environmental, Shire of Murray’s municipal boundaries. social and economic factors; and TPS4 sets out the Shire’s strategic direction through statutory provisions • Provision for industrial development which prescribe how development and in planned estates where land use use of land may proceed. conflicts and environmental impacts will be minimised and efficient Part 2 of TPS4 sets out the scheme’s production facilitated. objectives, which include:

6.8.4 Relevant Local Planning • To secure the amenity, health and Strategies convenience of the scheme area and its inhabitants; Hills Landscape Rural Planning Strategy (HLRPS) • To encourage industrial uses to The Hills Landscape Rural Planning establish within the area set aside Strategy (HLRPS) provides the 15- for that purpose; and 20 year strategic planning framework guiding development within the Shire of • To preserve the special environment Murray, including the area east of South associated with the lakes and Western Highway and the proposed waterways within the scheme area. Pinjarra Bypass alignment. The document is underpinned by principles which relate This scheme does not identify any to the conservation of agricultural land, buffer around Alcoa’s Pinjarra Refinery the protection of the Darling Scarp’s operations. regional and local visual significance, the protection of remnant vegetation, and the co-location of Rural Residential development with existing urban centres. 40 Pinjarra Long Term Residue Management Strategy

Existing Environmental Issues 7 and Management Strategies

7.1 Environmental Management • detailed procedures for managing The SRG members were provided with Systems key system elements including, detailed information on the current issues Environmental issues at the residue area but not limited to, environmental and management strategies for the are managed through a comprehensive training, incident reporting and residue area to enable them to provide environmental management system internal auditing, informed input into the development of (EMS). The EMS was initially developed the LTRMS. for the residue area in recognition of the • detailed procedures for the control importance of a rigorous, documented of operations to minimise potential 7.2 Dust process of environment management and impacts, certified to ISO 14001 in December 1999. 7.2.1 Background Subsequently the EMS was extended to • extensive process emission and One of the key community concerns the remainder of the Pinjarra Refinery, environmental impact monitoring, discussed by the Pinjarra LTRMS SRG which gained ISO 14001 certification and related to dust from the residue area and in June 2002. The key elements of the management strategies to control this system are: • an annual process of reviewing key potential impact. environmental issues and developing • an environmental policy, environmental improvement Dust generated from the residue area initiatives for each operating area. mostly consists of fine clay particles • processes to identify environmental and sodium carbonate crystals. The legislation, The remainder of this section describes sodium carbonate is precipitated on the the key potential environmental issues surface of residue as entrained moisture • a risk based process for identifying for the residue area. These have been evaporates. Residue dust is alkaline key environmental aspects and identified through risk assessment and could be an irritant to the eyes, potential impacts, processes and also reflect issues of nose, throat and lungs if high enough concern to stakeholders as identified by concentrations occurred, however, the Pinjarra LTRMS SRG. extensive monitoring data shows this is Alcoa of Australia Limited 41

very unlikely. If dry residue surfaces are not correctly managed, wind speeds in excess of 6.5 m/s (23 km/h) can lift and transport the fine residue and carbonate particles. The distance over which these particles are transported depends on a variety of factors including atmospheric conditions and the size, shape and mass of the particles.

As well as the residue drying beds, surrounding infrastructure such as roads, embankments and drains can also be a source of airborne dust and are managed accordingly.

October to April is the period when risk of airborne dust generation is potentially Figure 7-1: Complaints for residue dust from 2000 to 2015. greatest, however Alcoa implements Note – only 4 of the 14 complaints registered in 2006 were attributable to Alcoa’s operations. a detailed dust management program throughout the year irrespective of the season. In summer, the predominant 7.2.2 Current Management extended period are planted winds are moderate to strong Strategies with native vegetation or grasses east-southeasterly and moderate The nature of bauxite residue and the during winter to allow them to southwesterly winds. Strong and gusty deposition and drying processes result establish an effective long term east-southeasterly often start around in a range of differing materials and dust control cover, midnight, peaking between 2am and surface textures that have the potential to 5am, and abating mid-morning. The generate dust under windy conditions. As »» embankments or areas that are speed of these winds together with such the dust management systems in not required in the shorter term the higher ambient temperatures over place are complex and consist of a range are covered with aggregate or summer, and therefore faster mud drying of proactive and reactive strategies. mulch, and rates, require careful control mechanisms Significant effort is invested in planning, to prevent dust being released. implementing and monitoring the dust • the frequency for application of dust control measures to ensure best possible suppressants to exposed surfaces, There were 19 complaints Alcoa received management of dust generated from the such as roadways, is specified. between 2010 and 2015 that related embankments, stockpiles, roads, verges to dust. The number of residue dust and drains. Mid-Term Controls (weekly) complaints received since 2000 is shown Dust management is reviewed at weekly in Figure 7-1 below. Long term, mid-term and day to day meetings, which include the personnel controls are in place to manage residue involved in dust control. Weekly field Residue dust emissions are historically dust at Pinjarra. An overview of each inspections and surveys are carried out to well within licence limits, with no follows. check the effectiveness of dust controls exeedance of licence limits attributable to and identify areas needing attention. Alcoa between 2010 and 2015. Long Term Controls (annual) These reviews monitor the ongoing risk On an annual basis, dust control of exposure to dust events. The SRG made a point of acknowledging measures for the coming year are the significant improvement in dust planned to ensure: A specialist consulting company supplies management practices since the 2011 seven day and seasonal weather review (Guiding Principle 1a). The sprinkler • dust control mechanisms are in forecasts, which are reviewed weekly and upgrade project completed in January place for any newly constructed allow Alcoa to maintain preparedness for 2009, together with increased operational or exposed embankments before conditions conducive for dust generation focus on dust control measures, is stronger winds are forecast, by, for example, operating sprinklers well perceived to have made a significant ahead of forecast winds. difference to overall dust performance. »» new or exposed internal embankments likely to remain in place undisturbed for an 42 Pinjarra Long Term Residue Management Strategy

In addition, the following specific mid- term dust control methods are employed by Alcoa to minimise dust generation:

• regularly turning over the mud in the drying area thereby leaving wet mud on the surface,

• spraying exposed banks and roads with dust suppressants,

• restricting vehicle access to exposed areas, and

• detailed investigations into exceedences of internal targets to prevent reoccurrences.

Day to Day Controls On a daily basis the specialist consulting Figure 7-2: Licensed dust monitoring locations. company also supplies a local rolling three day weather forecast, which includes a Dust Risk Rating that takes into account monitored historically at Pinjarra is as accordance with DER licence conditions. rainfall, wind speed and wind direction. follows: These licence conditions specify the maximum target concentration of TSP The main day to day control mechanism • TSP (Total Suspended Particulate at the premise boundary as a 24 hour to manage dust emissions from the Matter) – particles with an average, as determined by continuous drying beds is the use of the sprinkler aerodynamic diameter <50 µm, and monitoring using high volume air system. The sprinkler system is operated samplers (Hi-Vols).

in response to daily weather forecasts • PM10 (particulate matter <10 µm) and residue area conditions, and – particles with an aerodynamic Dust Performance feedback from continuous dust monitors diameter <10 µm. All licensed dust monitoring data is around the residue area. Internal alarms presented in annual environment reports are triggered in the event of dust levels Currently TSP is monitored around to the DER. rising above internal targets. Sprinklers the refinery and residue area at nine

are operated in response to alarms and dust monitoring locations. PM10 was Between 2010 and 2015 there have been proactively to wet down areas prior to monitored at Pinjarra for a period in order no exceedances of Alcoa’s licence target. forecast weather conditions. to collect data for a residue dust health A number of exceedances of internal risk assessment (HRA), however this targets for the licensed monitors have 7.2.3 Dust Monitoring monitoring ceased in 2007. Results of been recorded and investigated during the Particles exist in the atmosphere the health risk assessment are discussed period 2010-15. Of these exceedances, contributed from a range of sources, in Section 7.5. six were potentially attributable to Alcoa. both natural and man-made. Alcoa’s dust Dust monitoring results are reviewed at monitoring program is in place to monitor Pinjarra Refinery’s DER licence requires each CCN meeting. the contribution of dust particles from the continuous operation of High Volume residue areas to the local surrounding Air Samplers (Hi-Vols) which produce 7.2.4 Residue Dust Studies environment, as well as monitor overall daily averaged dust concentrations. Following on from the Wagerup PM10 ambient air quality in the area surrounding These are located at three compliance and PM2.5 study performed in 2002-03, the Pinjarra Refinery. sites: the Pinjarra Racecourse, Fairbridge Alcoa conducted a detailed study into Airstrip and Oakley South. residue dust to quantify the chemical Dust particles are present in a range makeup of the dust emissions and the of various size fractions with larger Figure 7-2 shows the current residue particle size distribution of residue dust. size fractions typically responsible for dust monitoring network. The study aimed to assess the quantity of amenity impacts, whilst smaller size PM10 and PM2.5 in dust emissions and at fractions are respirable and may therefore Ambient Dust Standards receptors, compare these concentrations present potential health concerns. Ambient dust emissions monitoring at to NEPM standards and assess the The terminology for dust size fractions the Pinjarra residue area is carried out in physical and chemical properties of Alcoa of Australia Limited 43

residue dust. The information was then used in a quantitative HRA of residue emissions and to further understand the impacts on amenity.

The results from the residue dust study and associated health risk assessment are discussed in Section 7.5.

Impact of Expanded Residue Footprint on Dust Emissions As a result of the identification of potential development areas via the life- of-mine planning process, as discussed in Section 8, modelling will be conducted on various expansion scenarios. Results will be used to confirm the suitability of the preferred development areas and to inform Alcoa’s position on compatible land use development around our operations required to protect our ability to operate to our life-of-mine timeframes.

This modelling will also take into account the projected required stack heights on dust emissions for the various scenarios. 44 Pinjarra Long Term Residue Management Strategy

7.2.5 Guiding Principles and VOCs are a class of chemical compounds The VOCs emitted at the highest Alcoa’s Commitments that are readily released from water or air rates from residue were (in order of In response to the information provided, emissions at normal temperatures. While significance): the Pinjarra LTRMS SRG developed a some are contributors to odour (such number of Guiding Principles. Those as acetaldehyde, benzaldehyde and • acetone, related to the issue of dust are presented propanol), others are more of interest from below, together with Alcoa’s response. a health perspective (eg formaldehyde, • acetaldehyde, and benzene and toluene). Guiding Principle: 1a) Residue Dust • 2-butanone (methyl ethyl ketone). Control and Improvement There have been very few odour The SRG acknowledges that dust control complaints at Pinjarra over recent years The study also confirmed that a number at Pinjarra residue has significantly and none relating specifically to the of environmental factors affected the improved since the last LTRMS. residue area itself. The SRG advised release of odour and VOCs from sources that odour was not currently an issue of in the residue area. The rate of release of Alcoa to maintain the current dust control concern in the community. odour and VOCs from residue sources is measures and seek to research and affected by surrounding air temperature, implement improved methods of control, 7.3.2 Odour and VOC Monitoring with lower release rates at night than where possible. Results during the day, and lower rates in winter In 2004, odour and VOC emissions from than in summer. The release rate is also Alcoa’s Response various residue sources at Wagerup affected by local wind speeds, with lower Alcoa is committed to maintaining our Refinery were measured directly for the release rates at lower wind speeds. current dust control measures and first time. The emissions monitoring seeking opportunities to improve the program targeted VOCs, carbonyls and 7.3.3 Current Management implementation of these measures. In odour and used a flux chamber monitoring Strategies addition we will continue to evaluate new technique. The results of this monitoring Odour and VOC emissions from the surface dust control measures as they become enabled an understanding of the relative of the residue area are a function of the available. significance of diffuse emission sources temperature and odour/VOC concentration within the residue area. Because of at the residue surface. The higher the Guiding Principle: 1b) Dust the similarities in process between the temperature and compound concentration – Reporting of Results Wagerup and Pinjarra refineries these of the liquor surface, the higher is the The SRG request dust monitoring findings can be applied to Pinjarra. emission of odour/VOC to air. The main results presented to the CCN include source of VOC input into the residue area assessments against the internal targets, Tests results indicated that odour comes from refinery cooling water. In most and that any changes to dust monitoring emission rates are a function of surface cases, cooling water that makes contact programs are discussed with, or moisture levels, temperature and liquor with refinery liquor streams will condense presented to, the CCN. concentrations. Consequently the major and absorb VOCs from the liquor. sources of odour and VOCs from residue Alcoa’s Response were those receiving liquor at higher There are currently no management Alcoa accepts and agrees with this temperatures. For Pinjarra these are (in strategies in place to actively manage principle. order of significance): VOC concentrations to the residue area via the cooling circuit. 7.3 Odour & VOCs • Cooling pond, 7.3.4 Impact of Expanded 7.3.1 Background • Super-thickener, Residue Footprint Odorous emissions from alumina refineries It is expected that the direction of are caused by the breakdown of organic • Sand discharge pond, proposed future residue expansion to the material contained in the bauxite, additives northeast will directly influence the areas to the liquor stream and by-products of • Drying beds (wet), in which odour emissions may increase. fuel combustion processes. Odour comes Modelling will help determine the extent of from a range of compounds, including • Drying beds (dry), and increases for different sensitive premises. some volatile organic compounds (VOCs), potential ammonia sources and others, • Low concentration, cool liquid Any increase in wind speed associated and is an amenity issue of concern for the surfaces (such as Run-off Water with an increase in stack height has the local community. Storage and Run-off Collection effect of diluting and dispersing odour. ponds). Therefore, with any height increase of the stack, the impact is likely to be a lessening of ambient odour from residue. Alcoa of Australia Limited 45

RSA10 Odour Impact sensitive receptors were generally 7.3.5 Guiding Principles and The construction of RSA10, within low. Odour assessors were unable to Alcoa’s Commitments Pinjarra’s current industrial zoned distinguish refinery and residue odours In response to the information provided, footprint, contributed a further 90 at a distance from the refinery. The the Pinjarra LTRMS SRG developed a hectares of drying area. This represents highest odour levels detected were to number of Guiding Principles. Those an increase in total drying area for the north-east, close to the refinery. related to the issue of odour and VOC Pinjarra of approximately 27%. One of Some odour was also detected to emissions are presented below, together the commitments of the RSA10 Works the south and west of the refinery at with Alcoa’s response. Approval was to produce an Odour distances of approximately four to six Assessment Plan. The objectives of the kilometres. Refinery odours were not Guiding Principle: 3a) Odour plans are to: detected at North Pinjarra. A post RSA10 - Significance commissioning field odour survey was The SRG acknowledges that odour from »» Determine worst case conducted during late 2015 and early residue is not currently considered a meteorological conditions for 2016. The post commissioning survey major issue for the community. However odour from the Refinery and/or results indicated that the resulting odour odour impacts of an expanded residue Residue Storage Area to impact observations were lower than predicted footprint, including wet lake relocations, Pinjarra, North Pinjarra (Carcoola) by the baseline odour survey, for both the should be considered. or the undeveloped urban zone maximum odour level and frequency. The along South Western Highway post commissioning survey concluded Alcoa’s Response between these two sites, that RSA 10 has not perceptibly Odour impacts will be addressed in increased ambient odour attributable to environmental and planning approval »» Establish baseline odour intensity Alcoa’s Pinjarra operations. The survey applications, as required. levels at nearby receptors also concluded that odour levels at near through a Baseline Field Odour sensitive receptors attributable to Alcoa’s Guiding Principle: 3b) Odour – Survey targeting worst case Pinjarra are low. Control and Improvement meteorological conditions, and Pinjarra Refinery to implement, where Cooling Pond Relocation possible, any odour reduction strategies »» Determine if the operation of The impact of odour emissions from the identified as part of Alcoa’s broader the new Residue Storage Area, Cooling Pond was considered in the research programs. RSA10 causes a perceptible decision to relocate the pond from its increase in odour at these previous location. Emissions from the Alcoa’s Response receptor locations under worst Cooling Pond in its current and previous Where opportunities for odour reduction case meteorological conditions location were modelled and provided to from residue are identified as part of (Post RSA10 Commissioning the DER as part of the Works Approval Alcoa’s broader research programs, Field Odour Survey). application process. Pinjarra Refinery will assess these for their applicability, effectiveness, cost and benefit An RSA10 pre-commissioning baseline to its operations. Appropriate long term odour survey was undertaken in 2014. strategies for the implementation of odour Results showed that odour levels near reduction opportunities will be developed. 46 Pinjarra Long Term Residue Management Strategy

7.4 Radiation Radon Total Dose Monitor Gamma Standard Progeny (Ann) 7.4.1 Background Residue Operator <0.12 <0.12 <0.24 Radiation is widespread in our environment. It comes from sources Residue Maintainer 0.16 0.42 0.58 outside the earth’s atmosphere, rocks Dozer Driver 0.12 <0.12 <0.24 1 and soils and from building materials such as bricks, mortar, concrete and Residue Super Thickener <0.12 <0.11 <0.43 tiles. It also comes from the food and RSA Central <0.12 <0.10 <0.42 drinks we consume, and from man-made sources such as dental and chest x-rays. Table 7-1: 2008-09 NORM monitoring results for residue personnel.

Background radioactivity levels are quite • whether potential end-uses of the Therefore, while bauxite and bauxite variable. Levels associated with the rocks residue materials are radiologically residue contain traces of radioactive and soils of the Darling Range are usually acceptable. materials, exposures associated with this higher than those found on the coastal have been comprehensively studied and plain. Darling Range soils, including the This has involved comprehensive all levels have been demonstrated to be bauxite deposits, contain small amounts monitoring of air, water and soil, and well within acceptable limits prescribed of thorium and uranium. The extraction has included both fixed location (area) for both the workforce and the public. of around 30% of the bauxite as alumina monitoring and personal sampling of results in a proportional increase in the members of the workforce who spend 7.4.3 Changes in Radiation concentration of these elements per most of their time working on the Management Since 2011 volume of residue. The dry stacked residue surface. Results are documented Recently the International Atomic Energy residue mud itself therefore exhibits in scientific reports, and have been Agency developed guidelines on the levels of gamma radiation marginally provided to relevant government management of materials that contain above background levels found in Darling agencies. Sampling equipment, methods naturally occurring radioactive material Range soils (O’Connor, 1989). It should and techniques have been endorsed by (NORMs) Australia has adopted these be noted that no radiation is added relevant statutory bodies such as the guidelines which require materials with through the refining process. Radiological Council of WA. radiation levels above 1 Bq/g to implement specific monitoring and reporting, however 7.4.2 Radiation Monitoring Results The accepted international and national Western Australia is yet to implement these Alcoa has been studying the radiological radiation limit for occupational exposure guidelines. aspects of its bauxite processing is 20 mSv (millisieverts) averaged over a operations in Western Australia for more period of five consecutive calendar years. Once the guidelines have been than 25 years. The various studies have The accepted international and national implemented in Western Australia, Alcoa considered the following major issues: radiation limit for the general public is will request exemption to the reporting 1 mSv per annum (above background). requirements if it can demonstrate • whether the low levels of natural All personal exposure readings for the exposure levels to radiation for radioactivity in feedstock, Alcoa residue workforce are below the employees are less than 1 mSv/year intermediate and final materials limit set for the general public. That is, (public exposure). (products and residue) pose readings have been more than 20 times discernible problems from a radiation less than the limit allowed for workers. There has been no additional monitoring health perspective and, if so, what focused on NORM since the previous actions might be required for the Studies have also found that in the campaign undertaken in 2008-09 where operations to be managed in a unlikely event that a member of the Alcoa performed NORM monitoring responsible and acceptable manner, public would spend 24 hours per day, focused at mining and residue to provide 365 days per year at the edge of the information required to support a future • whether the processing of bauxite residue area, then the exposure received application for exemption. The results, materials poses discernible would be approximately 0.12 mSv above as shown in Table 7-1, are well below the radiological hazards for the local background. This level is well within public exposure standard. workforce and for members of the the limits that are applied to the general general public, including impacts public and well below the background from the residue area prior to and levels experienced in many residential following rehabilitation, and areas on the Darling Scarp. Alcoa of Australia Limited 47

7.4.4 Current Management 7.5 Residue Emissions and Health 7.5.2 Health Risk Assessment Strategies Results Although radiation levels are low 7.5.1 Background An HRA is a risk assessment process that enough that no specific management Air emissions from residue that have the compares the ground level concentrations strategies are required to meet accepted potential to impact on community health (GLCs) of compounds with their health exposure standards. Alcoa uses the include dust from RSAs, embankments guidelines set by national and international three principles of radiation protection and other sources as detailed in Section health agencies. The GLCs are predicted to minimise exposure of employees to 7.2, and chemical compounds emitted by air dispersion computer modelling. The radiation. These are: from wet storage areas and other sources HRA considers the: as detailed in Section 7.3. • time: radiation dose is directly • risk of short-term (acute) health proportional to duration of exposure, The potential health impacts of dust are effects in relation to short term related to the size of the dust particles, exposures (one-hour & 24 hour • distance: the distance of exposure their chemical composition, and most averages), determines the dose rate according importantly their concentration in the air to the inverse square law, and near residential areas. Very small dust • risk of long-term (chronic) health

particles (PM10 and PM2.5) can be breathed effects in relation to long term • shielding: the effectiveness of a into the lungs and in major cities have been exposures (annual averages), and material for radiation shielding associated with heart and lung disease. is determined by its density and Additionally some chemicals in residue • incremental risk of cancer in relation atomic number. dust and vapour, such as formaldehyde to long term exposures (annual and acetaldehyde, and the alkalinity of the averages over 70 years). Personal exposure monitoring has dust, are potentially irritants if high enough determined that the exposure to concentrations occurred. To increase confidence in the 2008 HRA employees from radiation is below for dust, the 2008 HRA contained several accepted health standards. Some compounds such as acetaldehyde layers of conservatism. It assumed have low odour thresholds and can be sources were emitting at peak emission 7.4.5 Impact of Expanded detected at concentrations which are rates simultaneously, and assumed Residue Footprint too low to cause health effects. Similarly the risks of emissions were additive in The nature of radiation exposure means larger dust particles can cause an nature. The model took into account that changes to the height or footprint amenity impact even though they do not local meteorological conditions including of the residue area will not increase constitute a potential health impact. northerly winds. the risk of radiation to the public. Immediately adjacent to the boundary In 2004, Alcoa voluntarily committed The 2008 HRA considered inhalation of an expanded residue area the levels to a major research program aimed at exposure to the following substances/ of radiation exposure will remain well further improving our understanding of the elements: below exposure standards and less than contribution made to regional dust by the natural background levels in many local alumina refineries in WA. An independent • PM10 (Particulate Matter < 10 µm residential areas. Health Risk Assessment (HRA) was then diameter), and performed to investigate the health risks 7.4.6 Guiding Principles and associated with residue dust. In 2008 • The metals arsenic, selenium, Alcoa’s Commitments another HRA was undertaken for the manganese, cadmium nickel, In response to the information provided, Refinery and residue as a part of the Pinjarra mercury, chromium, beryllium, lead the Pinjarra LTRMS SRG determined Efficiency Upgrade (PEU) to 4.2 million and vanadium. that no Guiding Principles for radiation tonnes per annum. Results of these HRAs were required. Radiation management were detailed in the 2011 Pinjarra LTRMS. and reporting was considered to be adequately managed through government reporting processes. 48 Pinjarra Long Term Residue Management Strategy

Other metals analysed but for which These results reinforce that Alcoa’s The results of the revised 2014 Health Risk health guidelines were not available operations are safe for both our employees Screening Assessment (Environ, 2014) were not included in the 2008 HRA. The and neighbouring communities. They indicated that, in relation to the proposed full details of the 2008 HRA (Environ, indicate that the composition of the dust incremental increase in the alumina 2008) can be found on Alcoa’s website: has extremely low levels of trace metals, production capacity of the Pinjarra http://www.alcoa.com/australia/en/ and the estimated cancer risk level is well Refinery up to 5 Mtpa, the potential for sustainability/health-wellbeing.asp below the global recommendation set by emissions to cause acute or chronic non- the United States EPA of one in a million. carcinogenic health effects as well as the Based upon the results of the HRA it can potential for emissions to contribute to be concluded that: 7.5.3 Impact of Expanded the incidence of cancer in the exposed Residue Footprint population remains low. The results of • the potential for emissions from the The most significant factor affecting the the 2014 air modelling and health risk baseline or upgraded RSA to cause short term exposure contours around the screening assessment were subjected

acute health effects presents no residue area is the PM10 component of to peer reviews (Pacific Environment cause for concern, residue dust emissions. Limited, 2015 and Weinstein, 2015), with the outcomes of the peer reviews • the acute Hazard Index (HI) is Alcoa will update the dust modelling and submitted to the EPA. The results of the

primarily driven by exposure to PM10, HRA as required in the future to inform 2014 HRA were presented to the Pinjarra not to individual metals in RSA dust, plans that involve making significant CCN in early 2016. changes to the residue area. • the potential for emissions from the 7.5.4 Guiding Principles baseline or upgraded RSA to cause In 2014, the Air Quality Model for the and Commitments chronic health effects represents no refinery was updated (Air Assessments, In response to the information provided, cause for concern, and 2014) to reflect the proposed incremental the Pinjarra LTRMS SRG determined increase in alumina production capacity that a Guiding Principle relating to health • the potential for emissions from to 5 million tonnes per annum (Mtpa). impacts of residue dust was not required. the baseline or upgraded RSA to The model update included changes contribute to the incidence of cancer to the residue area since the previous based on inhalation exposure is modelling in 2008. The results from the low, below the USEPA de minimis updated model were used to revise threshold of one in a million. the 2008 Pinjarra Refinery Health Risk Screening Assessment using the latest health protective guidelines. Alcoa of Australia Limited 49

7.6 Oxalate However this was not the preferred 7.7 Water Use long term strategy for Alcoa as oxalate 7.6.1 Background disposed with the residue returns 7.7.1 Background Bauxite ore contains some organic impurities to the process, rather than Pinjarra Refinery sources over 90% of matter (plant and animal matter) that removing them permanently. its water from groundwater bores and forms oxalate during the alumina surface water dams located within the refining process. Over time, the level 7.6.2 Management Strategies refinery premises. The remainder comes of oxalate builds up in the recycled Currently the Pinjarra Refinery generates from the Pinjarra waste water treatment caustic liquor circuit, which negatively approximately 80 tonnes per day (tpd) of plant, refinery sewage and rainfall that impacts upon the alumina product quality oxalate. This is predicted to rise to up falls on the Pinjarra Refinery and residue and the production yield of alumina. to 85 – 95 tpd with increases in organic area. At times of low annual rainfall, Consequently, as part of the alumina levels in bauxite and alumina production additional water may be sourced from refining process, oxalate needs to be over the next five years. the Water Corporation. removed from the liquor. Although oxalate is a compound which is commonly found There are currently two methods of The refinery has been designed to in the environment and is not intrinsically managing sodium oxalate at Pinjarra operate an efficient closed water circuit, harmful, the oxalate extracted from Refinery; firstly via the oxalate kiln and which is supplemented for water losses. the refining process has a high caustic secondly via the oxalate bio-removal Losses of water primarily occur as steam concentration and hence requires plant. The oxalate bio- removal plant was from the process, evaporation from water appropriate storage and treatment. commissioned in 2013 and uses naturally storage areas and residue surfaces, occurring biomass to convert sodium water bound within the residue mud Prior to 2001, sodium oxalate was oxalate to sodium carbonate and sodium and sand, and some seepage from the destroyed by incineration in a kiln, bicarbonate. The bio-removal plant residue area. See Section 7.9 for further producing sodium carbonate, which is consumes significantly less energy than details. The largest use of water at the then converted to sodium hydroxide the oxalate kiln. This is then converted residue facilities is for operating sprinklers (caustic soda) and returned to the to sodium hydroxide and returned to to control dust. process. From 2001, sodium oxalate the process. Currently, excess oxalate is slurry was exported to Vanadium stored in lined ponds at the residue area. Process and potable water supplies Australia’s processing facilities at This will be recovered and processed as at Pinjarra Refinery are sourced, Windimurra for use as a fluxing agent. capacity becomes available. under licence from the Department of This allowed operation of the oxalate kiln Water (DoW), from six bores from the to be ceased. In 2003 the Windimurra 7.6.3 Guiding Principles Cattamarra aquifer, beneath the Alcoa operation closed and a search for and Commitments property. The Pinjarra Refinery currently alternative markets was unsuccessful. In response to the information provided, draws groundwater from the Cattamarra the Pinjarra LTRMS SRG developed one aquifer under groundwater licences. Before the oxalate kiln was Guiding Principle relating to oxalate. recommissioned it required an upgrade This is presented below, together with The refinery also holds a licence to take to its emissions controls systems. This Alcoa’s response. groundwater from the superficial aquifer involved installation of a wet scrubber to under the refinery and residue areas. remove particulates and a regenerative Guiding Principle: 6) Oxalate This licence allows for water to be drawn thermal oxidiser to destroy volatile The SRG notes that there is a commitment from the superficial aquifer by subliner organic compounds (VOCs) and carbon to recover all oxalate from residue storage drains and depressurising bores that monoxide. In the period between ponds, and that the preferred method of reduce upwards pressure on the RSA Windimurra closing and the oxalate kiln destruction of the stored oxalate is via bi- liners and also by recovery bores or being brought back online at Pinjarra ox, rather than via the oxalate kiln. wells for alkali recovery. in 2005, oxalate was reacted with lime and placed in the residue mud. This Alcoa’s Response Barritt Brook and Oakley Brook are method of disposal was approved by Alcoa is committed to recovering stored natural, seasonal creek systems which the Department of Environment after a oxalate from the residue area. Oxalate cross the Alcoa Pinjarra Refinery property risk assessment showed that the risk stored at residue is intended to be from east to west. Impoundments have of environmental or health impacts was destroyed via the biological oxidation been created on the main channels very low. facility, however the continued operation of Oakley and Barritt Brook as a of the oxalate kiln is required to treat contribution to plant water requirements. ongoing oxalate production. Uncontaminated stormwater flows into these impoundments and is then pumped 50 Pinjarra Long Term Residue Management Strategy

to the fresh Water Storage Reservoir. Alcoa committed to a water conservation • Implementation of managed aquifer Both systems discharge into the Murray program and participates in the recharge and recovery to reduce River well beyond the Alcoa property Water Corporations’ Water Efficiency natural evaporation losses. A hydro- boundary. The Lower Oakley Brook Management Plan programme. The geological feasibility study has been pumpback impoundment was designed objectives of Alcoa’s water efficiency completed. A further review is to be to only retain winter surge volumes. action plan are to: undertaken to determine if recharge Environmental flows are maintained by is a cost effective option. continuous release at the weir to ensure • Assess current water used on site riparian rights are observed. from all sources, • Implementation of residue filtration technology to recover more water The three water supply impoundments • Identify inefficiencies and potential from residue. Construction of a are operated under surface water water conservation measures, residue filtration facility at Kwinana licences issued by the DoW. Refinery is nearing completion and • Prepare an action plan to implement it will allow an assessment of the In addition, treated water from the water conservation actions, and applicability of the technology to Water Corporation’s Pinjarra wastewater Pinjarra Refinery to be undertaken. treatment plant is also accepted into the • Provide a platform for annual residue Runoff Collection Pond (ROCP) reporting on implementation of 7.7.3 Impact of Expanded and subsequently into the refinery water conservation actions. Residue Footprint process. In a typical year, Alcoa accepts With a stable production rate, the amount approximately 300ML of treated water. Water efficiency achievements relevant to of drying area will oscillate around a This water conservation initiative was residue include: relatively constant area (new areas will implemented in full consultation with the increase the open area but will then be Department of Environment Regulation, • Increase in water harvesting from consumed over time until new areas are and results in a significantly lower nutrient farmlands to reduce reliance on required to off-set the losses). In the load in the Murray River, which leads to scheme water as a backup. The event residue filtration is implemented at the Peel-Harvey Estuary. onsite dam capacity has been Pinjarra Refinery, the amount of drying increased to capture more run-off area required is expected to reduce The RSAs have base drainage systems from Alcoa’s farmlands. significantly. that collect residue leachate and rainfall infiltration. All rainfall runoff from the • Maintenance of the refinery water 7.7.4 Guiding Principles Refinery, RSAs and process water ponds is treatment plant to reduce reliance and Commitments transferred to the Cooling Pond or ROWS on scheme water as a backup. In In response to the information provided, Pond during winter and then used as make- 2013 a major replacement of the the Pinjarra LTRMS SRG developed a up water for the Refinery during summer. whole aeration tower at the water number of Guiding Principles. Those treatment plant was completed. related to water use are presented below, 7.7.2 Current Management together with Alcoa’s response. Strategies • Completion of a number of energy Operation of the residue sprinkler system efficiency improvements to reduce Guiding Principle: 5a) Water Use contributes significantly to water usage vapour losses to the atmosphere in - Conservation volumes. While this results in effective 2014. Alcoa to continue to conserve water dust management, Alcoa is also focused through reuse and reduction initiatives, on maintaining dust performance while A number of initiatives were reviewed identification of alternative sources and using water efficiently. or are undergoing investigation with the commitment to their use. long term view of reducing fresh water usage. These include: Alcoa’s Response Alcoa accepts and agrees with this • Use of an alternative water principle. supply from the Gordon Road wastewater treatment plant. The cost effectiveness of this project is dependent on other parties. While Alcoa is interested, the infrastructure would likely need to service and be funded by a broader customer group. Alcoa of Australia Limited 51

Guiding Principle: 5b) Water Use Under normal rainfall conditions water – Regional Water Requirements collected on the surface of the RSA is The SRG encourages Alcoa, where allowed to drain freely to the ROCP. Under practicable, to maximise the broader severe storm conditions water may need regional benefit of any future to be retained in the RSAs by closing infrastructure projects. the decant weirs in order to prevent an unmanageable amount of water reporting Alcoa’s Response to the ROCP. Operational guidelines Alcoa accepts and agrees with this stipulate that storm surge capacity must principle. We will cooperate with be maintained on the residue area to government initiatives for economic capture 100% of any storm event, based reuse of alternative water resources. on a 1:100 year, 72 hour storm, and a 12 to 13 day recovery period. 7.8 Surface Water The ROWS pond is used to accommodate 7.8.1 Background the surges in total water storage capacity The refinery has been designed to operate (i.e. cooling lake and the ROCP) as the an efficient closed water circuit, which evaporation and rainfall vary throughout is supplemented for water losses. See the year. This ensures that in exceptionally Section 3.8 for further details. Stormwater wet years, water collected from the that runs off the residue or refinery areas refinery and residue areas will not exceed is characteristically alkaline. This renders the residue area’s storage capacity. the water unsuitable for direct discharge to the environment. Therefore all rainfall The overall stability of the residue runoff from the refinery and residue area storage facilities has been designed in is collected and stored in lined ponds accordance with international standards within the residue area for recycling via to accommodate both static and the refinery process as make-up water. earthquake loadings. The structural integrity of water storage ponds and RSA In addition, fresh water only leaves the embankments are inspected annually by refinery’s operations via the fresh water a third party consultant. storage dams. The surface streams in the immediate vicinity of the Pinjarra Surface Water Monitoring residue areas include Oakley and Barritt A surface water monitoring program is in Brooks, which flow into the Murray River place at the refinery to measure long term (see Figure 6-2). quality changes associated with refinery and neighbouring activities. It also 7.8.2 Current Management Strategies provides data to ensure that abstraction Alcoa manages the risk of surface water levels do not exceed the water contamination from the residue area, by requirements of the local environment. implementing practical measures to ensure Surface water monitoring results are no contaminated stormwater is released. collated and reported annually to the DER and the DoW. The residue area has a 100% surface water containment policy. Surface water Water collected at Oakley and Barritt runoff and underdrainage is collected Brooks has exhibited seasonal variations in the ROCP and then pumped to the that parallel rainfall patterns at one of ROWS or Cooling Pond. Alcoa’s monitoring sites which is located upstream from the confluence of the 52 Pinjarra Long Term Residue Management Strategy

Murray River and Oakley Brook, and as 7.8.5 Guiding Principles and The need to contain the residue such, provides baseline conditions prior Commitments leachate meant that the embankments to any influence from Alcoa’s operations. In response to the information provided, the were originally designed as water Collected data indicates that Alcoa’s Pinjarra LTRMS SRG chose not to develop retaining structures that added further operations have no measureable impact any Guiding Principles relating solely to conservatism to their design. Their on water quality in the Murray River. surface water. However Guiding Principle construction included base and 4C, described in Section 7.8, refers to the embankment clay sealing layers. Flow data is obtained from v-notch protection of surface and groundwater weirs located near the junction of Barritt through appropriate design and construction The introduction of dry stacking of the Brook and the South West Highway, of future residue storage areas. residue in 1987 reduced the potential the junction of Oakley Brook and the for release of residue leachate to the railway bridge near the Pinjarra Williams 7.9 Groundwater Impacts surrounding environment as the lack Road, and Oakley Brook upstream of the of any significant water level within the Oakley Brook detention dam. Each weir 7.9.1 Background deposit decreases the pressure on the is equipped with a data logger to record Groundwater of useable quality is present base liners. stream levels which are used to calculate in the superficial strata within the region flow rates. of the existing and proposed residue All RSAs have base drainage systems. deposits. The quantity and quality of this These drainage systems provide a More detailed information relating to water generally renders it suitable for major defence against seepage to the surface and groundwater quality can stock watering only. ground water by substantially lowering be found in the Review of Groundwater the hydraulic head at the base of the and Surface Water Management report A more significant groundwater resource deposit. All RSAs constructed since which is submitted annually to the DER (the Cattamarra Coal Measure) is present 1983 have included PVC or HDPE liners and the DoW. in a sub artesian aquifer approximately to further mitigate seepage. A schematic 150 metres beneath the surface. This representation of RSA construction is 7.8.3 Changes in Management water is good quality and is utilised by the provided in Figure 7-3. Since 2011 refinery for potable and process make-up To maintain the relevance of the water. It is believed that this deep aquifer 7.9.2 Current Management surface water monitoring program, is recharged in the vicinity of the Darling Strategies ongoing reviews of the relevance of the Scarp, but in the vicinity of the residue Alcoa has a comprehensive groundwater monitoring parameters and frequencies area it is isolated from the surface by soils monitoring program to monitor changes are undertaken (the latest round was with very low permeability (Wainwright to groundwater levels and quality. Any undertaken in 2015). and Associates, 1984). The aquifer flows losses from the residue areas are typically in a westerly direction and discharges characterised by elevated total dissolved 7.8.4 Impact of Expanded into the Peel-Harvey Estuary. salts and elevated pH in the groundwater. Residue Footprint RSA10, the most recently constructed An increased residue footprint requires The potential impact of residue leachate RSA at Pinjarra, was commissioned in an increased storm surge capacity and on ground water quality was recognised 2015. RSA10 has a tri-liner consisting increased long term storage capacity when the Pinjarra Refinery was built and of a geosynthetic clay liner sandwiched for winter rainfall. The amount of as a result, the residue areas were located between two layers of HDPE. required water storage is a function of on areas of low-permeability clay soils. the total residue footprint, as water is Alcoa provided a report in 2007 to the collected from RSAs, embankments Alcoa has a number of management DER in accordance with the requirements and infrastructure areas to prevent any strategies for protecting groundwater, of the Contaminated Sites Act 2003, that contamination leaving the site. including pipe and process equipment identified the residue area as “Possibly integrity and containment management Contaminated – investigation required” Future residue areas and associated water programs. From the commencement of due to seepage from the RSAs. Alcoa storage infrastructure will be constructed Alcoa’s operations in Western Australia, is committed to implementing the in accordance with the current strict residue areas have been designed requirements of the Contaminated Sites residue engineering guidelines and and constructed in accordance with Act 2003, in line with DER Contaminated controls outlined in Section 4.5, ensuring contemporary accepted engineering Sites Guidelines, as agreed between Alcoa no additional likelihood of impact on standards which include containment and the DER. Alcoa provides regular surface water bodies. and leachate recovery systems. These updates to stakeholders on the progress design standards have improved since of these actions through consultation Alcoa constructed its first residue areas processes such as the CCN, the Pinjarra at Pinjarra. Refinery EIP, and the Pinjarra Refinery LTRMS SRG. Alcoa of Australia Limited 53

atura Sois omated ay rainage Pies omated ay Synteti Sea ater Tae

Sand Layers it Soar ried Storm ater nder rainage Mud oetion rain

Figure 7-3: Schematic showing construction method of residue drying beds.

The following areas within the residue RSA1 (Previous Cooling Pond) actions, which have been approved by area are identified to have elevated RSA1 was the first residue area the DER as part of the Works Approval alkalinity: constructed at Pinjarra Refinery and was for the pond conversion, are described in commissioned in 1972. This pond was built Section 8.5.3.2. • The western dyke of the ROWS to the standards of the day, which involved Pond, construction of the embankments and floor RSA2 with low-permeable clayey material. Plastic RSA2 is one of the older RSAs and does • The northern dyke of RSA1, liner was placed over an area of the floor not have an underdrainage system. where higher permeability material was • The northwestern corner of RSA 2, found. As other RSAs were constructed, Localised elevated alkalinity has been and RSA1 became the cooling water pond, and identified in the upper superficial aquifer after dry stacking was implemented, it was bores located around the northwestern • The southwestern corner of RSA 5. used as a ‘bypass’ area. corner of RSA2. The data from this area suggest a source of alkaline leakage into A summary of the strategies put in place Over the 37-year period of operation the upper superficial formations in the to address these issues follows. an alkaline plume has developed in the northwestern part of RSA2. superficial formation beneath RSA1. The ROWS Pond plume’s movement has been restricted The extent of the plume in the vicinity of Depressurising bores and a sub-liner by the low permeability of the strata and RSA2 and the requirement for remediation drainage system is in place for the ROWS natural chemical attenuation of the plume is being investigated. pond to reduce upward pressure from by aquifer materials. groundwater in the area and prevent RSA5 damage to the pond’s base seal. Water RSA1 North has now been relined as part In 2007, monitoring data in two upper levels in bores adjacent to the ROWS of a conversion project and RSA1 South superficial aquifer bores on the southwest Pond are monitored as part of the will also be converted in the future. This corner of RSA5 indicated a sudden groundwater level management program. is to allow dry stacking to take place and large increase in alkalinity and electrical its functionality has been replaced by conductivity, however, only a small Localised elevated alkalinity has been construction of a new, composite lined increase in pH was seen. This indicated found in one lower superficial aquifer Cooling Pond. a possible local source of alkaline bore on the western embankment of leakage. Subsequent monitoring has the ROWS Pond. The plume is moving As part of the conversion of RSA1 to dry shown parameters in one bore increasing northwest from the ROWS pond and stacking a number of actions are required and the other decreasing. Ongoing its shape indicates a localised source. to de-liquor the pond and address the monitoring of these bores is scheduled Alcoa is investigating the installation of a groundwater contamination. These with the need for future investigations to down gradient recovery system, possibly be determined. located on the northwest side of RSA10. 54 Pinjarra Long Term Residue Management Strategy

7.9.3 Changes in Management Current design, operational control Alcoa’s Response Since 2011 and monitoring systems in place Currently the ROWS pond conversion is Alcoa has established and maintains are demonstrated to be effective in planned as the next wet lake conversion. an intensive groundwater monitoring minimising the risk of any new residue However this is dependent on a number network consisting of residue area areas on the groundwater. of factors including funding and the perimeter bores and regional bores. ability to obtain the necessary approvals 7.9.5 Guiding Principles in the required timeframe (rezoning, and Changes in groundwater quality resulting and Commitments environmental approvals). from impact by Bayer liquor or residue In response to the information provided, leachate are primarily assessed using the Pinjarra LTRMS SRG developed a Guiding Principle: 4c) Groundwater pH, alkalinity, and electrical conductivity. number of Guiding Principles. Those – Integrity of the Sealed System and Of these, alkalinity is considered the most related to groundwater are presented Liquor Containment definitive. Alkalinity is a measure of the below, together with Alcoa’s response. Construction of all future residue quantitative capacity of a water solution drying areas at Pinjarra Refinery to be to neutralise an acid. Guiding Principle: 4a) Groundwater - conducted in a manner that ensures safe Monitoring and Response and secure storage of residue and does Detailed information relating to the Alcoa will continue to monitor not compromise ground water or surface groundwater monitoring program and groundwater quality around the residue water resources or restrict others’ use. current groundwater quality can be area to identify seepage and leaks from found in the Review of Groundwater the residue areas. Alcoa’s Response and Surface Water Management Report Alcoa accepts and agrees with this (Rockwater, 2015) which is submitted Where leakage is identified, Alcoa is principle. The current construction annually to the DER and the DoW. to commit to timely action to prevent method applied by Alcoa is designed to migration of contamination from the achieve this outcome. To maintain the relevance of the footprint, where possible. groundwater monitoring program, ongoing 7.10 Land Use Management and reviews of the monitoring parameters and Alcoa’s Response Visual Amenity frequencies are undertaken. Alcoa will continue to monitor groundwater quality around the 7.10.1 Background With the construction of RSA10, residue area to identify any potential Alcoa has significant landholdings around monitoring bores located along the contamination issues. Where issues the refinery and residue area. Original northern embankments of RSA6 and are identified, these will be investigated landholdings were acquired under the the ROWS pond were decommissioned. and appropriate management strategies Alumina Refinery (Pinjarra) Agreement New monitoring bores were installed developed to minimise their impact on Act 1969 to allow for future residue on the perimeter embankments of the environment and prevent any impact storage areas and refinery infrastructure RSA10 and were added to the ongoing on surrounding land/water users. As and to provide some separation between monitoring schedule. many of the monitoring bores are on the refinery operations and neighbouring the external perimeters of the residue communities. This land creates a visual 7.9.4 Impact of Expanded area, it is often not possible to detect buffer to the refinery and associated Residue Footprint contamination until it reaches the external infrastructure. There was no government Expansion of the residue footprint perimeter of the residue area. Monitoring requirement to purchase a buffer and increases the area over which there is results and progress on management there is no buffer defined for planning a potential risk to the groundwater from strategies are reported to the DER purposes for the refinery. caustic leakage. For this reason there annually in the Review of Groundwater are strict standards governing the design and Surface Water Management report. For the landholdings required for residue and construction of new residue areas. storage in the medium to long term future, Significant improvements in residue Guiding Principle: 4b) Groundwater interim land use management strategies design and construction techniques – ROWS Remediation are in place. Three main strategies are in have been made in recent years, with The SRG notes the remediation strategy in place to manage the current landholdings the inclusion of base drainage and clay- place to address identified contamination (not under residue) east of the South geomembrane liners into standard design. under the ROWS pond (RSA7). West Highway: The success of these improvements is reflected by groundwater monitoring The SRG recommends the ROWS pond • agricultural production, results. Groundwater monitoring be considered as the priority over the systems will continue to be constructed Water Storage Pond for the next wet • ecological protection and for new residue areas to ensure their lake conversion, to allow contamination restoration, and performance can be monitored and issues to be resolved. managed appropriately. • visual screening of Alcoa’s operations. Alcoa of Australia Limited 55

Due to the relatively flat landscape 7.10.2 Current Management It is acknowledged that there are locations surrounding the Pinjarra Refinery, and Strategies on private properties surrounding the the volume of residue to be stored, the A Land Management Program at Pinjarra refinery from which the residue areas residue area is becoming a prominent Refinery has been ongoing for the past 20 and the refinery are visible. Embankment feature on the local landscape. The area years and is focused primarily on the land rehabilitation will continue to minimise the occupied by residue is also visible from surrounding the residue area. A number of visual amenity impact from these locations. viewpoints along the Darling Range. ecological restoration and visual amenity projects have been undertaken. In some 7.10.3 Future Management Changes From the plain adjacent to the residue cases, these projects will require ongoing It is recognised that work to screen areas, the perimeter embankment slopes maintenance and management to ensure the expanding residue area from the are visible from some locations. However, their ongoing effectiveness. Weed community and to blend the residue the vertical dimension of the current control, feral animal management and fire areas into the surrounding landscape will deposits (approximately 45 metres above control activities are also managed under be ongoing. ground level), is low when compared to the Land Management Program. the Darling Range which rises to a height While the benefits of modifying of just under 200 metres in the area east As part of Alcoa’s visual amenity planning embankment shape will continue to be of the refinery. process, where the refinery creates assessed on a case by case basis, Alcoa a visual impact on the rural / natural believes that the most effective way to The Pinjarra LTRMS SRG raised visual landscape are identified and prioritised incorporate the residue area into the amenity as an important aspect and noted for visual amenity works. local surroundings is through appropriate the residue area is visible from a number of revegetation of the outer slopes. Natural locations other than major access routes. The focus of visual amenity efforts will variability to the appearance of slopes is The preference is to blend the residue continue on the rehabilitation of external hoped to be achieved through vegetation areas into the natural landscape. residue batters which will be increasingly selection. visible as the height of the residue area increases. However landscape planting Residue revegetation programs are is also undertaken along roadsides and outlined in Section 7.11. in farmland areas to complement this. 56 Pinjarra Long Term Residue Management Strategy

7.10.4 Impact of Expanded The SRG notes that the residue area is e.g. Between the residue area Residue Footprint more visible from locations at a greater and Fairbridge. The impact on visual amenity of an distance and height than the major e.g. Between the residue area and expanded residue area depends on access routes identified in the Visual South West Highway. the proposed layout and height of the Amenity Plan. Although screening from residue areas. Alcoa’s visual amenity these vantage points is not necessarily Alcoa’s Response planning process is continually reviewed possible, the visual amenity impact from Alcoa accepts and agrees with this in line with the long term expansion plans other locations should be noted. principle. Alcoa has a WA wide visual and additional planting may be required amenity lead team that meets regularly to screen planned future infrastructure, Alcoa’s Response to review planning and progress with preferably well before it is constructed. Alcoa accepts and agrees with this visual amenity plantings. The identified Future development footprint options principle. opportunities will be included in the take into consideration the positioning of Pinjarra Visual Amenity Plan. current visual barriers. Guiding Principle: 8b) Visual Amenity – Definition of Buffer Guiding Principle: 8d) Visual Amenity – 7.10.5 Guiding Principles The SRG notes that the purpose of any Amend Shape of Residue Storage Area and Commitments ‘buffer’ around the residue area needs to Alcoa to investigate opportunities to amend In response to the information provided, be well understood. There is a perception the rectilinear form of RSAs to make them the Pinjarra LTRMS SRG developed a among some that the sole purpose of resemble a ‘rolling hill’ rather than the number of Guiding Principles. Those a ‘buffer’ is for planting trees. While current rectangular style landform. related to visual amenity are presented visual amenity plantings should be a key below, together with Alcoa’s response. component of compatible land use, the Alcoa’s Response SRG notes this is not the sole purpose of Alcoa will consider this suggestion during Guiding Principle: 8a) Visual Amenity a buffer. the design phase of future embankment – Reporting and Review lifts. It should be noted that changing The SRG supports the implementation Alcoa’s Response the shape of the residue areas can and ongoing review and update of the Alcoa accepts and agrees with this introduce significant additional cost into Visual Amenity Plan. principle. the operations. Our preference is to use shrub and tree plantings to break up the The SRG requests any updates to the Guiding Principle: 8c) Visual Amenity linear profile of the residue areas. The Plan be reviewed by, or discussed with, – Revegetation Screening slope of the outer embankments is also the CCN and an annual report on the Alcoa to identify proactive opportunities reduced to 1:6 to provide more natural implementation of the plan is provided to to enhance and improve visual amenity profile for the areas. The effectiveness the CCN. through revegetation screening. of this approach is well demonstrated on the eastern side of the Kwinana residue area, adjacent to the Kwinana Freeway.

Plate 7-2: Current landscape, including the existing residue area. Alcoa of Australia Limited 57

7.11 Residue Area Rehabilitation residue area, and all leachate is collected Fifteen months after residue rehabilitation and returned to the refinery water has taken place botanical monitoring is 7.11.1 Background circuit. Refer to Sections 3.8 and 9.3 for undertaken to assess the performance There are two categories for the information about leachate management. of the rehabilitation. This botanical rehabilitation of the residue areas; these monitoring covers species diversity, are progressive rehabilitation and final Pinjarra’s existing rehabilitation program species abundance and percent rehabilitation. Progressive rehabilitation for residue areas uses native species, coverage. (Stage 5, Figure 7-4). is rehabilitation of an area concurrent primarily found on limestone outcrops with the operation of the area, which and in coastal heath lands. 7.11.3 Further Research is carried out on the external batters of Alcoa’s residue research program is the upstream sand embankments. Final The incorporation of gypsum (Stage regularly reviewed. These reviews form rehabilitation is the final sand spreading, 1, Figure 7-4) alters the properties of a basis for future research directions contour shaping, revegetation and residue to better reflect those of coastal aimed at developing a sustainable dewatering of the residue after closure of sandy soils common to the Swan Coastal vegetation cover on RSAs, maximising an RSA. Plain of Western Australia. Previous establishment of native vegetation, and rehabilitation practice incorporated optimising water and fertiliser use. The This section outlines the strategy for gypsum to a depth of 0.8 metres, but primary aims of residue rehabilitation progressive rehabilitation of the residue this has been increased to 1.5 metres to research are to: area. Final rehabilitation is addressed as allow deeper rooting of vegetation. part of the closure strategy discussion in (1) determine fundamental Section 9.4. To provide a supply of plant nutrients at characteristics (chemical, the time of planting, a custom blend of physical and biological) of The objectives of the residue rehabilitation fertiliser is applied (Stage 2, Figure 7-4). residue sand controlling water- program are to improve visual amenity Approximately 2.7 t/ha of di-ammonium nutrients-plant dynamics. of the external embankments, prevent based inorganic fertiliser is applied the generation of dust, and enhance the and incorporated to a depth of about (2) continue to refine the residue conservation value of the area in order to 0.2 metres. rehabilitation prescription achieve the progressive rehabilitation of to produce a sustainable the residue deposits. A mix of native seeds is broadcast over vegetation coversystem based the area. The seed mix contains a range on sound scientific principles in 7.11.2 Current Management of species found on sandy soils over the most cost-effective manner. Strategies limestone and is reviewed progressively The current focus of the rehabilitation in response to their relative success. (3) assist in developing strategies work undertaken at the Pinjarra residue A 30 millimetre deep layer of coarse for long term management of area is on external embankments (external wood mulch is subsequently spread to operating and closed RSAs. embankments are embankments on prevent the generation of dust from the the boundary of the life-of-mine residue bare surface before plant cover has been footprint which are unlikely to be established (Stage 3, Figure 7-4). disturbed in the medium term). The final step in rehabilitation operations Outer embankments are commonly is the hand planting of tree, shrub and constructed using residue sand, groundcover seedlings at an approximate produced after separation of the density of 1,200 stems/ha. (Stage 4, residue sand (>150 μm) from the Figure 7-4). The native species used are residue mud (<150 μm). The alkaline adapted to the local climatic conditions (pH >10) and saline (> 10 dS/m) nature and draw the water they need from of residue, coupled with its poor water the residue deposit. Water extraction retention properties, poses numerous by native vegetation will assist in restrictions for optimal plant growth. To reducing the total volume of water that help overcome these restrictions, the will eventually need to be treated prior residue sand embankments are left for a to release or reuse at closure. Alcoa’s minimum of two years to allow leaching residue rehabilitation research has shown of excess alkalinity and salinity. Leaching that rooting depth and therefore available of the sand prior to final revegetation water is strongly linked to the depth of occurs with within the confines of the gypsum presence in the soil profile. 58 Pinjarra Long Term Residue Management Strategy

7.11.4 Guiding Principles and Commitments The SRG’s Guiding Principles regarding Stage 1: rehabilitation are presented below, Gypsum incorporation together with Alcoa’s response. However, Gypsum for soil improvement further Guiding Principles focussed on (225 t/ha to 1.5 m depth) final land use closure and rehabilitation are presented in Section 9.6.

Guiding Principle: 7a) Rehabilitation – Integration with Surrounding Stage 2: Environment Fertiliser incorporation Alcoa aims its residue area rehabilitation DAP-based fertiliser for nutrient supply research at producing healthy sustainable (2.7 t/ha to 0.2 m depth) ecosystems that can provide habitats for native Western Australian fauna. Rehabilitated residue to be integrated with surrounding vegetation and local wetlands and creeks. The value of Stage 3: providing an east-west vegetation corridor Seeding and mulching for dust control and should be considered in preparation for protection of seedlings closure, using the rehabilitated external Seeding residue area embankments. (2-3 kg/ha of native coastal species) Woodmulch (600 m3/ha or 30 mm depth) Alcoa’s Response Alcoa accepts and agrees with this principle. Integration of the residue area into the local environment will not be Stage 4: possible until operations cease. However, Tube stock planting Alcoa will take measures to ensure Planting density that the revegetated embankments (approx. 1200 stems/ha; species not will be readily integrated into the local able to be grown from seed) environment at this time.

Guiding Principle: 7b) Rehabilitation – Fauna Monitoring Fauna in rehabilitated residue embankments and surrounding Current Vegetation target vegetation and wetlands should be Performance assessed through monitored to determine the effectiveness botanical monitoring of rehabilitation.

Alcoa’s Response Alcoa accepts and agrees with this Figure 7-4: Residue rehabilitation process. principle. Alcoa of Australia Limited 59 60 Pinjarra Long Term Residue Management Strategy

Short and Medium Term Residue 8 Development Strategies 8.1 Residue Planning and Design • changes in technology, • current proposed area over which Framework the residue area may expand during Alcoa is currently undertaking the • changes at the refinery affecting the the next 25 years (to 2040), and comprehensive residue management rate of production, planning processes for the short-term • current preferred area over which the (5 year), medium term (25 years), and • changes in quality of bauxite and/ residue area may expand during the life of the current mining lease (life-of- or characteristics of residue material life-of-mine (2045). mine, 2045). These planning processes streams (the drying area required give consideration to the guidance can be affected by small changes 8.3 Future Residue Planning provided through the LTRMS SRG in the percentage of mud in the Alcoa’s future residue planning work is process. Mud drying, embankment residue, with higher percentages of focussed on two key streams of work that construction, planned maintenance and mud requiring a greater drying area), are progressed in parallel: other sustaining activities are carried out in accordance with a detailed annual • weather conditions, in so far as they (1) Resear ch to identify program of work, which is developed can affect mud drying rates and mechanisms to reduce the within the context of the five year residue the construction schedules of new area required for future residue management planning process. residue areas, storage, and

Planning and design of all new residue • input from the community and (2) Futur e planning based on facilities is completed in accordance with regulatory agencies while obtaining current storage techniques. Alcoa’s Bauxite Residue Management the necessary statutory approvals Standard as well as relevant regulatory for new residue areas, 8.3.1 Research to Reduce standards and guidelines. In addition Residue Areas to outlining the process to be followed • internal funding availability which is Alcoa is dedicated to continually when selecting and confirming the social, influenced by a number of factors investigating new markets, products and environmental and engineering suitability including the global aluminium technologies that may lead to a reduction of areas for new residue facilities, these market, and in the area required for future residue documents prescribe minimum design storage. This work is currently focused in standards for all new facilities. For • the availability of key equipment three key areas: instance, detailed analysis is completed and contractors. to confirm that the short and long (1) Alternative uses for residue. term stability of earthen embankments The plans presented in the LTRMS are exceeds minimum requirements and therefore subject to change, particularly (2) Reducing required drying area/ investigations are completed to ensure the timing and sequence. The five time. that all storm water generated from the yearly review process undertaken for residue area in a 1:100 wet year is able the LTRMS is designed to allow these (3) Alter native storage technologies to be contained within the area without changes and their impact on long- and processes. release to the environment. term planning for the residue area to be reviewed with community and Alternative Uses for Residue 8.2 Constraints on Forward government stakeholders. In the event Alcoa has been developing alternative Planning of Residue Operations that a significant change will impact the uses for bauxite residue since 1978. Despite the level of effort which goes into five year plan presented in this document, Alcoa recognises that if significant forward planning, significant changes additional consultation may be required. alternative uses of residue can be are occasionally required as a result of a achieved, the rate of expansion of the range of factors including: This LTRMS identifies the: residue area can be slowed, and the long-term impacts of residue storage can • current projected residue footprint be reduced. See Section 4.6 for more for 2016-2020, detail on Alcoa’s residue reuse research. Alcoa of Australia Limited 61

Reducing Required Drying Area • Residue water use would be 8.3.3 Residue Storage Techniques and Time significantly reduced, Guiding Principles Alcoa uses a drying model formula to In response to the information provided, assist in its residue planning. This formula • Reduced potential to produce dust the Pinjarra LTRMS SRG developed helps Alcoa to determine the drying area from the RSAs, and one Guiding Principle relating to residue required to ensure that the mud can dry storage techniques. This is presented sufficiently to gain the required strength. • Reduced potential to impact below, together with Alcoa’s response. This formula can be simplistically groundwater. represented as: Guiding Principle: 15) Footprint Alcoa is currently installing the filtration Reduction Opportunities drying area required = tonnes mud per process at the Kwinana Refinery, with The SRG requests Alcoa works towards day x 100 days / mud density / pour depth commissioning due to commence in implementing processes that will enable the first half of 2016. If the filtration a reduction in the drying area required Alcoa is continuously looking for ways to process proves to be a success, Alcoa for Pinjarra’s residue operations. reduce the number of days of required drying will investigate the feasibility of installing The SRG notes that Alcoa is currently time, and hence the drying area required. the filtration process at Pinjarra Refinery. investigating the application of residue If improved drying times can be achieved filtration technology. The SRG supports whilst maintaining the structural integrity of 8.3.2 Future Planning active consideration of implementing this the residue areas, this would reduce the Although Alcoa is actively pursuing technology. Progress in this evaluation rate new residue areas are required. Alcoa mechanisms to reduce the area required should be reported to the CCN on a recently trialled alternative amphirolling for future residue storage, due to the long regular basis via the LTRMS update. cycles and the use of flocculants to assist lead times required for planning, Alcoa with residue dewatering. must continue its future residue planning Alcoa’s Response based on the current storage techniques, Alcoa accepts and agrees with this A flocculant product called Rheomax was until any alternative mechanism is proven principle. Pinjarra Refinery is currently trialled. Rheomax is a polyacrylamide/ and fully implemented. investigating new technologies for acrylate mixture that is chemically additional residue storage, including equivalent to the flocculants currently The future residue strategies presented residue filtration. Final adoption of the used in the super-thickener. It was in Section 8.5 are therefore based on next residue storage technology will added at the end of the residue pipe at the current residue storage techniques. include a number of factors, including very low rates, just before the residue Information on how these plans would be cost effectiveness. is deposited in the RSA. Unfortunately, modified if residue filtration is introduced these trials demonstrated that no at Pinjarra Refinery are presented in significant reduction in drying time was Section 8.6. achieved and the use of Rheomax was discontinued.

However, the trials of alternative amphirolling cycles were successful and changes were made to the amphirol operations as a result.

Alternative Storage Technologies and Processes Alcoa is currently investigating the feasibility of introducing large scale filter presses to the Pinjarra Refinery. The filter presses essentially work by forcing the moisture out of the residue, leaving behind a dry filter cake. If these filter presses prove a viable option for the Pinjarra Refinery’s residue area, this could have a number of advantages:

• Residue operations could be sustained within the current footprint for approximately the next 20 years, Current Pinjarra Refinery Residue Area Layout 62 Pinjarra Long Term Residue Management Strategy

8.3.4 Residue Area Planning The impact of stack height on visual neighbours, Alcoa’s ability to develop Considerations amenity, dust and footprint area have the whole of this area will be determined As the mud elevation in RSAs increases over also been taken into account. by our ability to adequately address time, perimeter embankments progressively the impacts of the environmental and move inwards and the net available drying 8.5 Future Plans with heritage issues noted above. area reduces. As a consequence, to Current Technology maintain the minimum drying area required This section details Alcoa’s future residue East and Northeast Expansion to dry mud it is necessary to periodically plans based on the current storage Alcoa and the SRG considered easterly construct new RSAs. Alcoa uses a number techniques. expansion of the residue area suitable of principles in its planning processes to subject to some constraints. The extent plan for new residue areas. These include 8.5.1 Life-of-Mine Construction of the eastern expansion of the residue greenfield site assessment, footprint Strategy (2045) area is constrained by Alcoa’s property development direction, residue stack boundary, the topography of the area, heights, and proximity to neighbours. Development Direction and the cost and ability to relocate critical Alcoa has assessed options to expand infrastructure currently located in the area. The refinery has no defined statutory the residue area to the north, south, east In addition to the cost and engineering buffer at either local or state level, nor any and west in accordance with Alcoa’s constraints of the topography, development requirement under the State Agreement sustainability criteria, as outlined in Table to the east would require relocation of the Act or any other legislation to provide one. 8-1. A summary of this assessment for major gas pipelines and power lines. The The provision of an adequate buffer for each option is presented below. cost and ability to move this infrastructure, the refinery’s operations was, and still is, together with the availability of alternate intended by the State to be provided through Northern Expansion routes, requires further investigation. appropriate compatible land use planning. Alcoa and the SRG considered northerly Alcoa acknowledges that in order to inform expansion of the residue area suitable While the area identified in Figure 8-1 compatible future land use planning at both subject to some constraints. The extent represents the maximum extent of east a local and state level, the Shire of Murray of the northern expansion of the residue and northeast development currently and the Department of Planning require a area is constrained by Fairbridge Village to considered possible, Alcoa’s ability clear indication of our future residue storage the north, the township of North Pinjarra to develop the whole of this area will land use requirements. Accordingly, this to the northwest, and Alcoa’s property be determined by our ability to cost LTRMS review has sought to identify an boundary to the northeast. Hence any effectively address the impacts of area into which we require the ability to be northern expansion will only provide part the environmental and infrastructure able to expand. of the required future residue area for the constraints noted above. life-of-mine requirements. 8.4 Future Development Southern Expansion Alcoa assesses the various options for Other issues requiring further investigation The southern expansion of the residue new residue area development based on to the north include areas of aboriginal area is considered suitable subject to sustainability criteria. Table 8-1 provides artefact scatter, European heritage sites, some potential constraints. The extent examples of the considerations that are wetlands and the potential presence of of any southern expansion of the residue made in this assessment of each option. declared rare flora. area depends on whether a contiguous stack is able to be developed. A range of options for the life-of-mine Alcoa will seek to maximise the separation development direction for the refinery distance from Fairbridge Village and A contiguous stack would allow a more have been considered. The benefits and the cemetery. While the area identified efficient stack design and reduce the constraints to expanding the current in Figure 8-1 represents the maximum overall residue area footprint. However residue footprint to the north, south, north- extent of northern development currently this would only be possible if Oakley east and west of the current residue area considered possible, on the basis of Brook is able to be significantly realigned, have been considered and are discussed in anticipated separation requirements from aboriginal artefacts identified in the area further detail in Section 8.5.1. relocated, and the rail-loop to the refinery

Social Economic Environmental

» Potential amenity impacts on neighbours » Cost of construction and associated » Potential impact on ecological sensitive » Potential impact on heritage sites infrastructure relocation areas and species (Aboriginal and European) » Efficiency of stack design » Potential dust impacts » Visual Amenity » Flexibility to respond to uncertainty in » Water levels and contamination compliance requirements pathways » Ability to achieve necessary approvals

Table 8-1: Sustainability criteria used to assess footprint options. Alcoa of Australia Limited 63

able to be realigned. Water storage only), area to the north and east is not utilisable, then development of RSAs to the south The ability to realign the Hotham Valley • Expansion to the north and east will also be required within the life-of-mine railway to the west, and to clear native were preferred, as this would allow timeframe. The extent of any southern vegetation to the east, will also determine a consolidated drying footprint to be expansion will depend on the extent the extent of available area for a southern developed in one area and provide of constraints to the north and east. It expansion, regardless of whether it is a the most efficient stack design (and should be noted that if the development separate or contiguous stack. hence smallest overall footprint), and of a separate storage area is required to the south, a much larger footprint will be The development of a separate stack would • Expansion to the south is an required to the south than the footprint also require modelling to ensure projected acceptable option, if required, to that could have otherwise been utilised stack heights would not tunnel wind offset any loss of development to the north or east. between the two stacks towards Pinjarra. area to the north and east as a result of potential environmental If there is insufficient developable land The area proposed to the south, shown or development constraints. available to the north and east and in Figure 8-1, does not represent However, because of railway residue filtration is not implemented the maximum extent of the southern infrastructure and potential heritage and a separate southern storage area development currently considered possible, and environmental constraints to is required south of Oakley Brook or the but represents the area outer perimeter or the south, development of residue identified aboriginal heritage site, then land required in the event that development storage to the south would likely the southernmost extent of the footprint to the north and east is constrained and a be in the form of a separate stack required for the life-of-mine footprint may separate stack is required to be developed which would result in an increased be required to extend further to Alcoa’s south of Oakley Brook. total footprint of the residue area. southern property boundary. This will be reviewed in the next LTRMS review, when Western Expansion Although constraints to the south require a decision on residue filtration will have Alcoa proposed, and the 2010 SRG further consideration to determine their been made and the extent of constraints supported, that construction of future feasibility of being overcome, the current to the north and east are better known. RSAs between the current residue area view is that these constraints are greater and the township of Pinjarra was not than those to the north and east, and Alcoa has developed a proposed life-of- a suitable option on the basis of the consequently development to the south is mine development envelope as presented increased visual amenity impact, together the least feasible and sustainable option. in Figure 8-1. This area reflects the most with the potential difficulty of managing Development of RSAs to the west of the likely extent for development of residue dust impacts to acceptable levels any current residue storage footprint were not storage within the current life-of-mine closer to residents. The 2010 SRG considered by the 2016 LTRMS SRG. period (2045). The actual extent of the agreed that the area west of the residue area required for storage and associated area would be suitable for relocation of There is estimated to be between 380 infrastructure within this period will Refinery Water storage infrastructure, and 430 Ha of land suitable for residue be primarily affected by the extent of such as the Run-Off Water Storage storage development to the north and developmental constraints identified (ROWS) Pond and the Water Storage east of the current industrial zoned residue within the areas to the north and east, Reservoir (WSR), subject to acceptable footprint. The total area is estimated to as explained above. The proposed area odour modelling outcomes for the town. be able to accommodate approximately assumes maximum heights within the The Peel Region Scheme and Shire of 35 years of alumina production at stack of between 60 metres and 80 Murray Town Planning Scheme No. 4 current planned refinery rates under metres above ground level. were amended in 2013 to facilitate this. existing storage methods. If this entire north-eastern area is able to be developed The proposed western area is bounded Preferred Strategy it would be able to accommodate the by easements for high voltage power In relation to the discussion on the current life-of-mine (to 2045) residue area lines and the Dampier to Bunbury Natural preferred direction of an expanded requirements. Additional areas would be Gas Pipeline. This area and has been residue footprint for the Life-of-Mine required if the mining lease is extended or included in the total residue footprint area Strategy, the SRG and Alcoa agreed on the refinery production rate significantly to provide for additional water storage the following general principles: increased. This scenario does not take areas, such as the ROWS and fresh into consideration the possibility of water storage facilities. • Expansion of the drying area implementing residue filtration. In the footprint should not go west due event residue filtration is implemented the Height to the need to maintain the current future residue area required is likely to be The current residue strategy is to distance between the RSAs and significantly reduced. maximise stack heights because Alcoa the Pinjarra townsite (this area was believes this is the most sustainable considered suitable for Refinery If further studies find the whole identified 64 Pinjarra Long Term Residue Management Strategy

option. Economically an increased stack height has the benefit of requiring less land to store residue, and hence reduces capital costs. Socially, increased stack heights allows greater separation distances from RSAs to neighbours and reduces the overall land area which may have long term planning constraints. Environmentally a reduced footprint reduces the area at risk of future groundwater contamination and supports a range of alternate use and land use options.

It is acknowledged that increased stack heights are likely to be more visible than lower stack height options, and may provide a greater challenge for dust management. Increased stack heights also require careful management of hydraulic head, leaching time and structural stability. However previous SRG’s supported the principle of increased stack heights so long as management of these issues continued to improve. The current SRG acknowledged significant improvements in dust performance since Figure 8-1 Proposed Life of Mine Development Area. the last LTRMS review and supported final stack heights of between 60 metres and 80 metres above ground level for the used to develop the Northern footprint. future plans. final residue landform. The DER and Shire of Murray note The SRG recognises that rezoning will 8.5.1.1 Guiding Principles and that further necessary assessments or also be required to allow this land use. Alcoa’s Commitments approvals may be required. In response to the information presented, Alcoa’s Response the Pinjarra LTRMS SRG developed five Alcoa’s Response Alcoa accepts and agrees with this Guiding Principles relating to the Life of Alcoa accepts and agrees with this principle. As discussed during the LTRMS Mine Footprint. These are presented principle. The final development strategy stakeholder engagement meetings, below, together with Alcoa’s response. will be subject to required approvals and 2045 is the life of the current lease, but a detailed assessment of the best overall there are further provisions for the lease Guiding Principle: 12a) Footprint option at the time the individual RSA renewal which would extend the life- Development – Life of Mine (2045) development is required. of-mine. Were these extensions to be granted, the life-of-mine footprint options The SRG notes the basis for developing Guiding Principle: 12b) Footprint would require further review. new RSAs to the north and east of the Development – Life of Mine (2045) current residue area is to maximise The SRG agrees it is desirable to present Guiding Principle: 12c) Footprint separation of these areas from the the life-of-mine footprint (2045) based Development – Life of Mine (2045) majority of existing neighbours, and that on current technology and assumed The SRG notes that Alcoa will need Alcoa’s current strategy is to endeavour to production rates to provide certainty to consider any strategic mineral maintain a 2 km separation from current to other stakeholders. The SRG resource areas and associated buffers in residences in Carcoola/North Pinjarra recommends that the proposed life- development of the final footprint. where practicable, and a reasonable of-mine footprint be included in both separation from the Fairbridge Village regional and local strategic plans for the Alcoa’s Response settlement and cemetery. area to inform stakeholders of Alcoa’s Alcoa accepts and agrees with this principle. The SRG supports the logic of building the residue area to the north first, and then to the east, to allow cut from the east to be Alcoa of Australia Limited 65

Guiding Principle: 13) Compatible event residue filtration is not implemented A range of options for the life-of-mine Land Use Planning Around Alcoa’s include: development direction for the refinery Operations have been considered. The benefits and The SRG encourages Alcoa to continue • construction of a new ROWS pond, constraints to expanding the current working with relevant Local and State residue footprint to the north, south, government authorities to ensure future • conversion of RSA7 to residue north-east and west of the current land use development of surrounding storage, residue area have been considered and properties are compatible with their are discussed in further detail in Section current and planned operations. • construction of a new Water Storage 8.5. The impact of stack height on visual Reservoir (WSR), amenity, dust and footprint area have Alcoa’s Response also been taken into account. Alcoa accepts and agrees with this • conversion of RSA8 to residue principle. storage, Although the range of potential future RSAs required for the next 25 years has Guiding Principle: 14) Height • construction of a new RSA12, been determined, the actual footprint for The SRG recognises that the life-of-mine these areas will be confirmed following footprint is based on residue heights of • construction of a new RSA13, and further studies of the area and any between 60 and 80m above ground level. changes in residue storage technology. • relocation of infrastructure, as These studies, which are underway or Alcoa’s Response required, to support the above planned to support any required planning Alcoa accepts and agrees with this projects. applications and other required approvals, principle. will identify any potential environmental There may be a requirement to obtain or heritage constraints in the area. 8.5.2 Mid-Term Construction planning approvals to allow the A more detailed sequencing of residue Strategy (25 years) construction of RSA12 and RSA13 within areas to the north and east should be The key construction issues to be this timeframe. possible in the next 5 yearly LTRMS review. managed within the mid term include: The remaining mid-term residue It must be noted that the rate at which • maintaining the residue storage construction activities required in the the mid-term drying area footprint is and drying capacity to meet the event residue filtration is implemented consumed will be a function of the same requirements of the refinery, include: constraints discussed in Section 8.2, in addition to the following variables: • maintaining the water storage, surge • construction of a new ROWS pond, capacity, cooling and process water • design stack height, supply functions for the refinery, • conversion of RSA7 to residue ensuring they can service the storage, • residue reuse commercialisation increased residue area, and opportunities, • construction of a new Water Storage • relocation of infrastructure required Reservoir, and • implementation of residue filtration, to support the provision of adequate and residue drying and water storage • conversion of RSA8 to residue capacity. storage. • ability to locate wet lakes (Water Storage Reservoir and ROWS Pond) Within the next 25 years, assuming In developing a mid-term strategy, the key outside of the mid-term drying area current production rates, approximately consideration is the final footprint of the footprint in the required timeframe. 350 hectares of additional drying area is residue area and detailing a sequence of required. Projects designed to provide development which supports flexibility in the 8.5.2.1 Water Storage Reservoir 110 hectares of the 350 hectares drying final closure form. The proposed locations Relocation and Conversion area required are currently planned for the 350 hectares of potential additional The WSR currently provides storage to be constructed between 2016 and greenfield RSAs required in the next 25 for surface water from Oakley and 2020 assuming residue filtration is not years cannot be considered in isolation of Barritt Brooks, groundwater from implemented, and are presented in the longer term life-of-mine development licensed abstraction bores, good quality Section 8.5.3. In the event residue filtration requirements. Determining the life-of-mine condensate from the refinery and on is implemented it is anticipated RSA14 will development strategy is critical to informing occasions, makeup water purchased not need to be constructed. the medium term development. from the Water Corporation. Water stored in this reservoir is predominately used for The remaining mid-term residue dust control at the residue area and as construction activities required in the cooling water in the refinery. 66 Pinjarra Long Term Residue Management Strategy

The current WSR is surrounded by current and future drying area footprint, preventing surrounding areas from being consolidated. Maintaining the WSR in its current location will increase the rate of loss of drying area as new internal embankments are built, bringing forward the requirement for new RSAs.

Options for the location of a new WSR have been investigated, and were discussed with the previous 2010 SRG. As the WSR is basically a fresh water dam, with the least potential of any residue infrastructure to impact on the local community, the preferred location was agreed to be west of the current residue drying area. This location also preserves areas to the north, south and north-east of the current footprint for Figure 8-2: Proposed WSR location. future dry storage. The indicative location of WSR is shown in Figure 8-2. Alcoa’s Response • construction of a greenfield drying 8.5.2.2 Planning Strategy to Alcoa accepts and agrees with area, RSA14, to the east of the Support Future Residue this principle. current residue footprint, which Development Requirements will provide approximately 65Ha Rezoning of sections of Alcoa’s 8.5.3 Short Term Construction of drying area, or alternatively the landholdings from “rural” to “industrial” Strategy (5-7 years) implementation of a new residue may be required under the Peel Region Key issues to be managed within the handling technology (such as Scheme to allow construction of residue short term strategy are: residue filtration – see Section 8.6). storage infrastructure in new areas. The Shire of Murray’s Local Planning Scheme • maintaining the residue storage As outlined in Figure 8-3. would then also be required to be updated and drying capacity to meet the to reflect the Peel Region Scheme. requirements of the refinery, 8.5.3.1 Business as Usual Construction Activities 8.5.2.3 Guiding Principles and • maintaining the water storage, surge The following ‘business as usual’ Alcoa’s Commitments capacity, cooling and process water construction activities will be carried out In response to the information presented, supply functions for the refinery, over the period 2016 to 2020: the Pinjarra LTRMS SRG developed one ensuring they can service the Guiding Principle relating to the mid-term increased residue area, and • periodic raising of perimeter and construction strategy. This is presented internal embankments to maintain below, together with Alcoa’s response. • relocation of infrastructure required the freeboard necessary to support to support the provision of adequate proposed mud deposition activities Guiding Principle: 11) ROWS and residue drying and water storage and provide the capacity needed to WSR Locations capacity. contain runoff during extreme 1:100 The SRG notes the strategy for locating year, 72 hour storm conditions wet lakes to the west of the current Over the period 2016-2020, the following within the individual RSAs. Individual residue area is designed to minimise the potential new RSAs may be required dyke raises involve construction of a overall impact on the community from to accommodate expected refinery new embankment with a crest level residue infrastructure, as it allows new production: typically between 4 metres and 10 RSAs to be developed further from the metres higher than the previous crest existing community. • conversion of RSA1S to an active level, construction and/or relocation drying area, providing approximately of infrastructure associated with the The DER and the Shire of Murray note 35Ha of additional drying area, embankment lifts, that further detailed assessments or approvals may be required. • construction of a greenfield• construction of new underdrainage drying area, RSA11, within the systems associated with current residue footprint, providing hydraulic placement of sand in approximately 20Ha of additional new embankment walls and/or drying area, and stockpiles, Alcoa of Australia Limited 67

• installation of new decant structures, installed on top of this deposit which will Guiding Principle: 10) Footprint and/or relocation of existing then be covered with a synthetic liner. Development (5-9 years) decant structures, and associated The pressure of the residue stacked on The SRG encourages Alcoa to convert pipework, top of the liner will then allow the liquid in the ROWS pond prior to additional the existing stack to be pushed up and greenfield developments. • extension/modification of mud and out of the deposit, rather than down into sand distribution pipework, the groundwater. The synthetic liner will Alcoa’s Response minimise any additional contribution of Alcoa will consider this suggestion when • extension/modification of the liquor from the dry stacking operation. updating the residue master plan. The groundwater bore monitoring network, current master plan flags the possible This process will be aided by the installation construction of a small (20 Ha) greenfields • extension of sprinkler risers, and of wick drains which will feed into the RSA in the north east corner of the underdrainage layer to relieve the pore existing residue area (east of RSA10) • construction of new roads. pressure in the existing material. The wick as the earliest opportunity to reduce the drains will increase the permeability of current drying area deficit. Maintaining A number of techniques are used to the mud and speed up the consolidation adequate drying area is critical to the raise embankments. Where practical process, allowing the entrained liquid within long-term stability of the residue area. and cost effective, the preferred method the stack to be removed more quickly. In is to construct the embankments using addition, sediment de-liquoring will reduce 8.6 Future Plans with Residue hydraulically placed residue sand. leakage from the pond after the RSA Filtration However, it is sometimes necessary to conversion is complete. If investigations determine that residue construct residue sand embankments filtration is a feasible option for Pinjarra using mechanical placement techniques 8.5.3.3 RSA11 Construction Refinery, Alcoa would look to develop a (e.g. using scrapers or dump trucks) The indicative size and location of RSA11 filtration facility at Pinjarra Refinery within and/or raise embankments using is shown in Figure 8-3. The exact location the period covered by this LTRMS. mud sourced from the RSAs whereby and size will be accurately reflected in the mechanical placement and compaction required statutory approval applications This section details Alcoa’s future residue techniques are again necessary. after detail design is complete. plans based on the implementation of residue filtration 8.5.3.2 Cooling Pond Conversion 8.5.3.4 Guiding Principles and The second half of the conversion of Alcoa’s Commitments 8.6.1 About Filtration RSA1S (formally the refinery cooling pond) In response to the information presented, Pinjarra Refinery is currently undertaking a to dry storage is expected to be completed the Pinjarra LTRMS SRG developed one feasibility assessment on new technology by 2020. Guiding Principle relating to the short term for residue storage (residue filtration). construction strategy. This is presented The filtration process produces a dry The process for conversion of RSA1 has below, together with Alcoa’s response. residue cake by filtering mud slurry through been subject to detailed environmental a membrane. review by the DER via a Works Approval application. The conversion methodology is designed to reduce the source of existing groundwater contamination from the area and minimise any further contamination resulting from the area’s ongoing use as a dry storage area.

The RSA will be filled with a mixture of residue mud and sand which will then be covered with a residue sand layer. An under-drainage system will then be

Figure 8-3: 2016-2020 Residue area construction activities. 68 Pinjarra Long Term Residue Management Strategy

The technology Alcoa is evaluating 8.6.2 Life-of-Mine Construction The mid-term residue construction is called “plate and frame” pressure Strategy (2045) with Filtration activities that will be required with the filtration. The introduction of filtration development and implementation of to Pinjarra’s residue operations would 8.6.2.1 Requirement for Life-of-Mine residue filtration include: involve commissioning a filtration building Land Use Planning and mechanical system to place the dried Alcoa currently has sufficient industrial • construction of a new ROWS pond, mud in the RSAs (a conveyor system and zoned land to provide RSAs for the life- mechanical spreading equipment). of-mine if a filtration facility is developed • conversion of RSA7 to residue and fully implemented. This is based on storage, Alcoa has been regarded as the global the assumption the RSAs are developed benchmark in bauxite residue storage to 80 metres above ground level, and • construction of a new WSR, and will be the first major mining that the existing ROWS Pond and WSR company in Australia to introduce are relocated. • conversion of RSA8 to residue residue filtration with a facility currently storage, and under construction at Kwinana Refinery. 8.6.3 Mid-Term Construction Residue filtration is expected to provide Strategy (25-years) with • relocation of infrastructure, as a number of potential benefits including: Filtration required, to support the above The key construction issues to be projects. • a reduction in water usage, managed within the mid-term strategy include: New RSAs 12-14 will no longer • a reduction in the future residue be required. footprint, • maintaining the residue storage capacity to meet the requirements 8.6.3.1 Water Storage Reservoir • improved residue dam stability, of the refinery, Relocation and Conversion The Water Storage Reservoir (WSR) • a reduction in dust potential from • maintaining the water storage, surge currently provides storage for surface residue storage areas, and capacity, cooling and process water water from Oakley and Barritt Brooks, supply functions for the refinery, • reduction of residue storage costs. ensuring they can service the RSAs, As outlined in Section 8.5.2.1, Alcoa and plans to relocate the WSR to allow the The location of infrastructure for the existing residue area to be consolidated. potential residue filtration facility has • relocation of infrastructure required If filtration is introduced to Pinjarra not been finalised. The majority of the to support the provision of adequate Refinery, the WSR will still need to be conveying and dried residue handling residue and water storage capacity. relocated however this relocation would system will be located inside the current be delayed, most likely until 2032-34. residue storage footprint. Two possible locations for a residue filtration equipment building have been identified for more detailed evaluation – on the western side adjacent to the existing ROCP (inside the current industrial zoned area) and on the eastern side of the existing residue storage area (in an area that may require rezoning). These areas are shown above in Figure 8-4.

Figure 8-4: Proposed Filtration Facility Location Options. Alcoa of Australia Limited 69

8.6.4 Short Term Construction 8.6.4.1 Business as Usual • extension/modification of the Strategy (5-7 years) with Construction Activities groundwater bore monitoring Filtration The following ‘business as usual’ network, Key issues to be managed within the construction activities will be carried out short term strategy are: over the period 2016 to 2020: • extension of sprinkler risers, and

• maintaining the residue storage • periodic raising of perimeter and • construction of new roads. capacity to meet the requirements internal embankments to maintain of the refinery, the freeboard necessary to support A number of techniques are used to proposed mud deposition activities raise embankments. Where practical • maintaining the water storage, surge and provide the capacity needed to and cost effective, the preferred method capacity, cooling and process water contain runoff during extreme 1:100 is to construct the embankments using supply functions for the refinery, year, 72 hour storm conditions hydraulically placed residue sand. ensuring they can service the RSAs, within the individual RSAs. Individual However, it is sometimes necessary to and dyke raises involve construction of construct residue sand embankments a new embankment with a crest using mechanical placement techniques • relocation of infrastructure required level typically between 4m and 10m (e.g. using scrapers or dump trucks) to support the provision of adequate higher than the previous crest level, and/or raise embankments using residue water storage capacity. construction and/or relocation of mud sourced from the RSAs whereby infrastructure associated with the mechanical placement and compaction Over the period 2016-2020, the following embankment lifts, techniques are again necessary. construction activities are planned: • construction of new underdrainage 8.6.5 Guiding Principles and • conversion of RSA1S to an active systems associated with Alcoa’s Commitments RSA, providing approximately 35Ha hydraulic placement of sand in The Guiding Principles developed by the of additional RSA, new embankment walls and/or Pinjarra LTRMS SRG have been presented stockpiles, in this LTRMS in the sections relating • construction of a greenfield to Alcoa’s future residue plans based drying area, RSA11, within the • installation of new decant structures, on current technology. If investigations current residue footprint, providing and/or relocation of existing determine that residue filtration is a approximately 20Ha of additional decant structures, and associated feasible option for Pinjarra Refinery RSA, and pipework, and that it will be introduced, Alcoa will consider these Guiding Principles in the • construction and implementation • extension/modification of mud and detailed development of the revised plans of the new residue filtration and sand distribution pipework, for the Pinjarra residue area. handling facility.

These areas can be seen in Figures 8-1, 8-2 and 8-3. 70 Pinjarra Long Term Residue Management Strategy

Residue Closure and 9 Rehabilitation At closure, many of the The process of defining the closure will report to the underdrainage system. impacts arising during strategy will be ongoing. Final closure of There are two basic options for closure the Pinjarra residue area is many years of the residue deposits which have operations will no longer be away, and available technology and been considered. The first is to provide significant, for example dust community opinions regarding final land an impermeable cover to the residue use may change over time. deposits, effectively encapsulating the generation and water use. alkalinity within the deposit and shedding Key additional considerations The current closure strategy has rainfall. The second is to allow rainfall to three main objectives, being that infiltrate the deposit and set up ongoing at closure relate to the final de-commissioned residue areas should: collection and treatment facilities for form of the residue area, the alkaline water that will be collected. management of contaminated • have the capability to be used for These two options are further discussed productive community benefit, below. stormwater, management of leachate and final land use. • be safe and self-sustaining 9.1.1 Encapsulation structures in the long term, and At the time of closure, a surface seal (with This section outlines the similar permeability characteristics to the key issues discussed with • allow future access to residue for base seal) would be installed over the the Pinjarra LTRMS SRG for alternate uses. deposit and the drainage system turned off. This surface seal would exclude closure. Development of alternative uses for rainfall infiltration to prevent re-saturation bauxite residue has been one of the of the deposit which, if allowed to occur, major objectives of Alcoa’s residue would increase the head on the base seal development program since 1978. The and increase the rate of seepage. The current programs are described in detail surface seal would be protected by a in Section 4.6.2. The focus on reuse of residue sand layer. the product to reduce the final volume of residue remaining on the site after closure With this option, the leachable alkali is a key consideration in assessing remaining in the deposit at the time alternate closure strategies. of closure would be ‘encapsulated’ within the deposit. The surface runoff 9.1 Closure Strategy Options water may initially be alkaline due to the The rehabilitation of the residue deposits will alkalinity of the surface residue sand be ongoing during the operating life of the layer. Continuous rainfall leaching of this refinery. The perimeter embankments will surface sand layer would, over several be rehabilitated as the height of the stack years, reduce the alkalinity of the runoff grows, and revegetation of the surface of to the point where no treatment would be the RSAs will occur as each reaches its necessary prior to release. nominated final elevation. At the time of refinery closure, much of the rehabilitation 9.1.2 Continued Leaching will be complete with only minimal area This option assumes that leaching of remaining to be closed. the deposit would continue beyond the operating life of the refinery. Seepage of At the time the residue deposits are rainfall through the residue stack would closed, the residue will still contain large be encouraged, maximising the recovery quantities of leachable alkali. If rainfall is of leachable alkali, while maintaining a allowed to infiltrate the deposit, the alkali low hydrostatic head on the base seal. will be leached from the residue and Alcoa of Australia Limited 71

As for the encapsulation option, it should When the refinery closes, the alkaline • establishment of a wide range of be possible to release surface runoff water collected via surface runoff and vegetation types will be possible, water without treatment after several under drainage will no longer have a use limited initially by the alkalinity of the years of rainfall leaching of the residue as makeup water. If there are no other residue, but progressively improving sand capping layer. However the water commercial uses for the water, it will need as leaching continues, which passes through the stack and is to be treated and safely released to the collected via the internal drainage system environment. The surface runoff water • the deposit will be suitable for a would continue to leach alkalinity from and drainage water from the deposit wider range of end uses, and the stack. This water is likely to require will be managed to ensure the alkalinity treatment for some further period of time does not cause environmental damage. • the residue will be readily accessible if it is to be released to the environment. The volume of water to be collected, the if alternate uses for the residue are alkalinity of the water, and the timeframe able to be commercialised. 9.2 Current Closure Strategy over which treatment will be required are Based upon current storage technology currently unknown. However, options Decommissioned residue areas will have and the experience Alcoa has gained for treatment and discharge of this water the capability to be used for productive over the past 50 years in Western have been investigated and a likely community benefit. Currently, the residue Australia, the company presently range of costs developed for inclusion in rehabilitation research is focussed on believes that continued leaching of the closure funding. Options for the treatment establishing a native vegetation cover deposit beyond the time of closure is of leachate from the residue stack are using coastal dune species. We consider the preferred approach for closure of discussed in Section 9.3. this to be appropriate as: bauxite residue deposits. The advantages of this closure strategy • it is self sustaining once established, A schematic representation of a residue include: stack area at closure is provided in Figure • provides an aesthetic buffer to the 9-1. During construction, a sand drainage • continued leaching of the residue landform, and layer containing drainage pipes is placed will reduce its alkalinity, therefore above a compacted clay liner and a suitable reducing the potential for • can be readily adapted to other land liner at the base of the stack. Residue environmental impacts over time, uses (agriculture, industrial) at a is then stacked within the sand dykes future time if required. which form the perimeter embankments. • during the life of the refinery the Upon closure, the area is revegetated in a drainage will be returned to the Alcoa has undertaken research to quantify manner that meets the agreed future land refinery thereby eliminating the need the soil-water plant dynamics in residue use objectives for the site. for treatment, rehabilitation. This research is designed to inform the closure cover vegetation This may include placing a sand capping • contouring and revegetation of the options and our understanding of the layer over the stack prior to revegetation, outer slopes of the deposits can be post closure water balance within the which will assist in controlling wind and done progressively, residue stack. water erosion of the stack.

Liner

Sand Drainage Perimeter Layers Embankment Dried Sand Mud Capping Layer Sand Drainage Dykes Pipes Water Vegetation Table Cover

Figure 9-1: Preferred closure strategy for the residue areas at Pinjarra. 72 Pinjarra Long Term Residue Management Strategy

To date, much of this work has focussed processes for discharge. It is anticipated of land uses for the Western Australian on the residue sand embankments as that further analysis of water management residue areas. These land use options these areas are being progressively options will be included in future LTRMS included plantations of native trees, native rehabilitated. More complex studies will reviews. shelterbelts, irrigated lucerne, olives, be required to understand and model vine rootstocks, dryland and irrigated water transport in the entire stack. The benefits of successfully reducing pastures. Soil and plant analyses were the pH of the residue leachate will be undertaken routinely to determine 9.3 Water Balance/Discharge recognised at closure when the level of productivity and fertiliser requirements Management treatment of waters prior to reuse, and and to monitor soil development on As the residue deposits are closed, a the timeframe over which treatment the demonstration area. The results are revegetated surface will be established. is required, should be reduced. Water described in detail in a number of annual Both rainfall and liquor will continue to treatment options post closure will be reports and triennial reports to the DER. leach through the deposit and will be impacted by Alcoa’s ability to implement collected by the base drainage system methods of pH reduction of residue or to Sheep and cattle have also been grazed as an alkaline leachate. These waters manage alkalinity levels reporting to the on pastures on the demonstration area, will need to be treated prior to release, or residue area during active operations. and blood and tissue samples monitored reuse through other industries, once the routinely to identify any effects on animal refinery has closed. 9.4 Future Land Use Options and health. The results show that sheep and Revegetation cattle grazed on residue areas maintain The volume of alkaline drainage water The Pinjarra Refinery is located on land good health and do not develop marked produced will depend on the water use of which was used for general agriculture mineral imbalances. There is also no the established vegetation and the land prior to the construction of the refinery. evidence of heavy metal retention. area covered by residue. Minimising the Alcoa continues to graze cattle on parts footprint of the residue area is the most of the property not currently occupied by In addition, Alcoa’s commitment to effective way of reducing the volume of the refinery or residue area. focussed research will result in the alkaline drainage water requiring ongoing development of guidelines for establishing management. The selection of vegetation The Pinjarra SRG stated its preference a sustainable ecosystem on RSAs, both planted on the closed area has the next that, after closure and rehabilitation of under operating and closed conditions. biggest impact on the volume of water the residue area, the land will have the Current research is identifying ways to passing through the residue stack. capability to be used for productive improve the characteristics of residue to community benefit without detrimental make it more favourable to plant growth, One of the current focus areas for effect. Rather than identify specific and to evaluate whether the current residue rehabilitation research is to land uses for consideration, the SRG rehabilitation prescription can produce maximise the water use from vegetation developed a set of guidelines to assess an effective store-release cover system so that the volume of leachate requiring appropriate final land use options. In to help manage deep drainage. treatment is reduced. Guiding Principle 9a it states that “the group believes the choice of future land At Kwinana Refinery, a motor sports A range of options for the management use should consider: complex has been developed on a of the excess water have been identified, section of land previously used for including: • a range of land uses including rural residue storage and the requirement for or industrial uses, that site is that closed residue areas are • treatment and discharge to the ocean suitable for light industrial use. or a local surface water source, • the existing natural and heritage values of the area, The dry stacks are being constructed in • managed aquifer recharge, and a manner that leaves the way open for • the existing surrounding land uses, a number of possible future land uses. • treatment and reuse (eg for stock and and Residue sand is being used to construct irrigation, industry or potable use). the outer embankments and base • the needs of Pinjarra and the broader drainage systems, and to provide a layer Further assessment of these options Peel Region. of free draining sand on the outer slopes requires identification of background water of the deposits. The high permeability of quality parameters for potential receiving This recommendation is consistent with residue sand ensures all water entering water bodies, a review of the pertinent Alcoa’s commitment to demonstrate a the residue surface is retained within standards relating to different water range of possible land use options for the stack, and negligible runoff occurs. sources and their uses, assessment of the the residue deposits. In 1994, a section The current design therefore eliminates treatment options, cost implications and of closed drying area at Pinjarra Refinery was established to demonstrate a range Alcoa of Australia Limited 73

Plate 9-1: Agricultural land uses demonstrated at Pinjarra residue area. significant erosion of the embankment 9.6 Closure Guiding Principles documented in an agreement with Alcoa. surface under wet weather conditions. and Alcoa’s Commitments The community and local government In response to the information provided, shall be involved in developing the The height and shape of the residue the Pinjarra SRG LTRMS developed a closure strategy. area at closure is also an important number of Guiding Principles. Those characteristic. As the height of the stack related to closure are presented below, Adequate financial provisions shall be increases, the outer slopes created by together with Alcoa’s response. made so that the State, local community raising the perimeter embankments and the Shire of Murray are not left with a will be progressively contoured using Guiding Principle: 9a) Closure legacy of adverse impacts. residue sand and vegetated. Also, – Final Land Use any requirements for drainage and After closure and rehabilitation of the Alcoa’s Response runoff control will be installed as the refinery and residue area, the land Alcoa will abide by all government embankments are raised. These outer should have the capability to be used for requirements that apply to closure slopes will comprise approximately one productive community benefit without funding and ensure that adequate third of the total area occupied by residue. detrimental effect. The SRG believes the provision is made so that there is no choice of future land use should consider: liability is left to the State. At each review of the LTRMS the opportunities for future use will be • a range of land uses including rural Guiding Principle: 9c) Closure – reviewed with the community and or industrial uses, Leachate Treatment strategies will be updated on a five yearly Alcoa to identify new options for basis. This will ensure the options being • existing natural and heritage values leachate treatment onsite to minimise investigated remain consistent with the of the area, environmental risk post-closure. needs of the community and Alcoa. • existing surrounding land uses, and Alcoa’s Response 9.5 Closure Funding Specific leachate treatment options will Alcoa will abide by all statutory, corporate • needs of Pinjarra and the broader be identified closer to closure. Given the and relevant accounting standards that Peel region. rapid developments in new technology, it apply to residue management and ensure would be premature to identify options so that adequate provision is made so that Alcoa’s Response far out from closure. there is no liability to the State. Alcoa accepts and agrees with this Principle.

Guiding Principle: 9b) Closure – Long Term Responsibility The ultimate responsibility for enforcement of compliance with closure management requirements lies with the state government and shall be 74 Pinjarra Long Term Residue Management Strategy

Stakeholder Reference Group 10 Guiding Principles 10.1 Summary of Guiding These Guiding Principles are discussed Principles and Alcoa’s further in the body of this document, Response together with the information discussed The Pinjarra LTRMS has been significantly on each of the issues to which they relate. influenced by input from the community, via the SRG process. As reflected The Guiding Principles will be reviewed throughout this document, the SRG and updated during the next review of the participated in extensive discussion LTRMS by future SRGs. on residue management and planning issues, enabling them to develop well-informed Guiding Principles for consideration by Alcoa.

Table 10-1 Stakeholder Reference Group Guiding Principles and Alcoa’s Response.

Guiding Principle Alcoa’s Response

1 DUST

a) Control and Improvement Alcoa is committed to maintaining its current dust control The SRG acknowledges that dust control at Pinjarra residue measures and seeking opportunities to improve the has significantly improved since the last LTRMS. implementation of these measures. In addition we will continue Alcoa to maintain the current dust control measures and seek to evaluate new dust control measures as they become to research and implement improved methods of control, where available. possible.

b) Reporting of Results The SRG request dust monitoring results presented to the CCN include assessments against the internal targets, and that any Alcoa accepts and agrees with this principle. changes to dust monitoring programs are discussed with, or presented to, the CCN.

2 RESIDUE REUSE

a) Priority Alcoa to continue actively pursuing alternative uses of residue. Alcoa accepts and agrees with this principle. Initial emphasis is to be placed on residue sand.

b) Reporting Alcoa to report to the CCN annually on the status of research Alcoa accepts and agrees with this principle. into residue re-use, including the status of any approvals required for its use. Alcoa of Australia Limited 75

Guiding Principle Alcoa’s Response

3 ODOUR a) Significance The SRG acknowledges that odour from residue is not currently Odour impacts will be addressed in environmental and planning considered a major issue for the community. However odour approval applications, as required. impacts of an expanded residue footprint, including wet lake relocations, should be considered.

Where opportunities for odour reduction from residue are b) Control and Improvement identified as part of Alcoa’s broader research programs, Pinjarra Refinery to implement, where possible, any odour Pinjarra Refinery will assess these for their applicability, reduction strategies identified as part of Alcoa’s broader effectiveness, cost and benefit to its operations. Appropriate research programs. long term strategies for the implementation of odour reduction opportunities will be developed.

4 GROUNDWATER

Alcoa will continue to monitor groundwater quality around the residue area to identify any potential contamination issues. a) Monitoring and Response Where issues are identified, these will be investigated and Alcoa will continue to monitor groundwater quality around the appropriate management strategies developed to minimise residue area to identify seepage and leaks from the residue their impact on the environment and prevent any impact on areas. surrounding land/water users. As many of the monitoring bores are on the external perimeters of the residue area, it is often not Where leakage is identified, Alcoa to commit to timely action possible to detect contamination until it reaches the external to prevent migration of contamination from the footprint, where perimeter of the residue area. Monitoring results and progress possible. on management strategies are reported to the DER annually in the Review of Groundwater and Surface Water Management report. b) ROWS Remediation Currently the ROWS pond conversion is planned as the next The SRG notes the remediation strategy in place to address wet lake conversion. However this is dependent on a number identified contamination under the ROWS pond (RSA7). of factors including funding and the ability to obtain the The SRG recommends the ROWS pond be considered as the necessary approvals in the required timeframe (rezoning, and priority over the Water Storage Reservoir for the next wet lake environmental approvals). conversion, to allow contamination issues to be resolved. c) Integrity of the Sealed System and Liquor Containment Alcoa accepts and agrees with this principle. Construction of all future RSAs at Pinjarra Refinery to be The current construction method is designed to achieve this conducted in a manner that ensures safe and secure storage outcome. of residue and does not compromise ground water or surface water resources or restrict others’ use.

5 WATER USE a) Conservation Alcoa to continue to conserve water through reuse and Alcoa accepts and agrees with this principle. reduction initiatives, identification of alternative sources and commitment to their use. b) Regional Water Requirements Alcoa accepts and agrees with this principle. We will cooperate The SRG encourages Alcoa, where practicable, to maximise with government initiatives for economic reuse of alternative the broader regional benefit of any future infrastructure projects. water resources. 76 Pinjarra Long Term Residue Management Strategy

Guiding Principle Alcoa’s Response

6 OXALATE

Alcoa is committed to recovering stored oxalate from the The SRG notes that there is a commitment to recover all residue area. Oxalate stored at residue is intended to be oxalate from residue storage ponds, and that the preferred destroyed via the biological oxidation facility; however, the method of destruction of the stored oxalate is via bi-ox, rather continued operation of the oxalate kiln is required to treat than via the oxalate kiln. ongoing oxalate production.

7 REHABILITATION

a) Integration with Surrounding Environment Alcoa aims its residue area rehabilitation research at producing Alcoa accepts and agrees with this principle. Integration of the healthy sustainable ecosystems that can provide habitats for residue area into the local environment will not be possible until native Western Australian fauna. Rehabilitated residue to be operations cease. However, Alcoa will take measures to ensure integrated with surrounding vegetation and local wetlands and that the revegetated embankments will be readily integrated creeks. The value of providing an east-west vegetation corridor into the local environment at this time. should be considered in preparation for closure, using the rehabilitated external residue area embankments.

b) Fauna Monitoring Fauna in rehabilitated residue embankments and surrounding Alcoa accepts and agrees with this principle. vegetation and wetlands should be monitored to determine the effectiveness of rehabilitation.

8 VISUAL AMENITY

a) Reporting and Review The SRG supports the implementation and ongoing review and update of the Visual Amenity Plan. The SRG requests any updates to the Plan be reviewed by, or discussed with, the CCN and an annual report on the implementation of the plan is provided to the CCN. Alcoa accepts and agrees with this principle. The SRG notes that the residue area is more visible from locations at a greater distance and height than the major access routes identified in the Visual Amenity Plan. Although screening from these vantage points is not necessarily possible, the visual amenity impact from other locations should be noted.

b) Definition of Buffer The SRG notes that the purpose of any ‘buffer’ around the residue area needs to be well understood. There is a perception among some that the sole purpose of a ‘buffer’ is for Alcoa accepts and agrees with this principle. planting trees. While visual amenity plantings should be a key component of compatible land use, the SRG notes this is not the sole purpose of a buffer.

c) Revegetation Screening Alcoa accepts and agrees with this principle. Alcoa has a WA- Alcoa to identify proactive opportunities to enhance and wide visual amenity lead team that meets regularly to review improve visual amenity through revegetation screening. planning and progress with visual amenity plantings. The e.g. Between the residue area and Fairbridge identified opportunities will be included in the Pinjarra Visual e.g. Between the residue area and South West Highway. Amenity Plan.

Alcoa will consider this suggestion during the design phase of future embankment lifts. It should be noted that changing the shape of the residue areas can introduce significant additional d) Amend Shape of Residue Storage Areas cost into the operations. Our preference is to use shrub and Alcoa to investigate opportunities to amend the rectilinear form tree plantings to break up the linear profile of the residue areas. of RSAs to make them resemble a ‘rolling hill’ rather than the The slope of the outer embankments is also reduced to 1:6 to current rectangular style landform. provide more natural profile for the areas. The effectiveness of this approach is well demonstrated on the eastern side of the Kwinana residue area, adjacent to the Kwinana Freeway. Alcoa of Australia Limited 77

Guiding Principle Alcoa’s Response

9 CLOSURE a) Final Land Use After closure and rehabilitation of the refinery and residue area, the land should have the capability to be used for productive community benefit without detrimental effect.

The SRG believes the choice of future land use should Alcoa accepts and agrees with this principle. consider: • a range of land uses including rural or industrial uses, • existing natural and heritage values of the area, • existing surrounding land uses, and • needs of Pinjarra and the broader Peel region. b) Long Term Responsibility The ultimate responsibility for enforcement of compliance with closure management requirements lies with the State government and shall be documented in an agreement with Alcoa will abide by all government requirements that apply to Alcoa. The community and local government shall be involved closure funding and ensure that adequate provision is made so in developing the closure strategy. that there is no liability left to the State.

Adequate financial provisions shall be made so that the State, local community and the Shire of Murray are not left with a legacy of adverse impacts. c) Leachate Treatment Specific leachate treatment options will be identified closer to Alcoa to identify new options for leachate treatment onsite to closure. Given the rapid developments in new technology, it minimise environmental risk post-closure. would be premature to identify options so far out from closure. 78 Pinjarra Long Term Residue Management Strategy

Guiding Principle Alcoa’s Response

10 FOOTPRINT DEVELOPMENT (5-9 years)

Alcoa will consider this suggestion when updating the residue master plan. The current master plan flags the possible construction of a small (20 Ha) green-fields RSA in the north The SRG encourages Alcoa to convert the ROWS pond prior to east corner of the existing residue area (east of RSA10) as the additional greenfield developments. earliest opportunity to reduce the current drying area deficit. Maintaining adequate drying area is critical to the long-term stability of the residue area.

11 ROWS AND WSR LOCATIONS

The SRG notes the strategy for locating wet lakes to the west of the current residue area is designed to minimise the overall impact on the community from residue infrastructure, as it allows new RSAs to be developed further from the existing community. Alcoa accepts and agrees with this principle.

The Department of Planning, Department of Environment Regulation and the Shire of Murray note that further detailed assessments or approvals are required.

12 FOOTPRINT DEVELOPMENT - LIFE-OF-MINE (2045)

a) The SRG notes the basis for developing new RSAs to the North and East of the stack is to maximise separation of these areas from the majority of existing neighbours, and that Alcoa’s current strategy is to maintain a 2 km separation from current residences in Carcoola/North Pinjarra and a reasonable Alcoa accepts and agrees with this principle. The final separation from the Fairbridge Village settlement and cemetery. development strategy will be subject to required approvals and a detailed assessment of the best overall option at the time the The SRG supports the logic of building the stack to the North individual RSA development is required. first, and then to the East, to allow cut from the East to be used to develop the Northern footprint. Dept of Planning, DER and Shire of Murray note that further necessary assessments or approvals are required.

b) The SRG agrees it is desirable to present the life-of-mine footprint (2045) based on current technology and assumed Alcoa accepts and agrees with this principle. As discussed production rates to provide certainty to other stakeholders. during the LTRMS stakeholder engagement meetings, 2045 The SRG recommends that the proposed life of mine footprint is the life of the current lease, but there are further provisions be included in both regional and local strategic plans for the for the lease renewal which would extend the life of mine. area to inform stakeholders of Alcoa’s future plans. Were these extensions to be granted, the life of mine footprint The SRG recognises that rezoning will also be required to allow options would require further review. this land use.

c) Footprint Limitations The SRG notes that Alcoa will need to consider any strategic Alcoa accepts and agrees with this principle. mineral resource areas and associated buffers in development of the final footprint. Alcoa of Australia Limited 79

Guiding Principle Alcoa’s Response

13 COMPATIBLE LAND USE PLANNING AROUND ALCOA’S OPERATIONS

The SRG encourages Alcoa to continue working with relevant Local and State government authorities to ensure future land Alcoa accepts and agrees with this principle. use development of surrounding properties are compatible with their current and planned operations.

14 HEIGHT

The SRG recognises that the life of mine footprint is based on Alcoa accepts and agrees with this principle. stack heights of between 60 and 80m above ground level.

15 FOOTPRINT REDUCTION OPPORTUNITIES

The SRG requests Alcoa works towards implementing processes that will enable a reduction in the drying area Alcoa accepts and agrees with this principle. Pinjarra Refinery required for Pinjarra’s residue operations. The SRG notes is currently investigating new technologies for additional residue that Alcoa is currently investigating the application of residue storage, including residue filtration. Final adoption of the next filtration technology. The SRG supports active consideration of residue storage technology will include a number of factors, implementing this technology. Progress in this evaluation should including cost effectiveness. be reported to the CCN on a regular basis via the LTRMS update.

16 REPORTING ON THE PROGRESS OF GUIDING PRINCIPLES

Alcoa to report annually to the CCN on its progress against the “Guiding Principles” developed by the 2016 Pinjarra LTRMS Alcoa accepts and agrees with this principle. SRG. 80 Pinjarra Long Term Residue Management Strategy

11Glossary CCN Community Consultative Network CSIRO Commonwealth Scientific and Industrial Research Organisation DEC Department of Environment and Conservation (now the Department of Environment Regulation) DER Department of Environmental Regulation DIA Department of Indigenous Affairs DoW Department of Water EIP Environmental Improvement Plan GLC Ground Level Concentration HDPE High Density Polyethylene Hi-Vol High Volume Air Sampler HRA Health Risk Assessment LTRMS Long Term Residue Management Strategy Mtpa Million Tonnes Per Annum NEPM National Environment Protection Measures NORM Naturally Occurring Radioactive Material PM2.5 Particulate Matter less than 2.5 μm in diameter PM10 Particulate Matter less than 10 μm in diameter PVC Polyvinyl Chloride ROCP Runoff Collection Pond ROWS Run Off Water Storage RPLG Residue Planning Liaison Group RSA Residue Storage Area SRG Stakeholder Reference Group TEOMs Tapered Element Oscillating Microbalances tpd Tonnes Per Day TSP Total Suspended Particulate VOC Volatile Organic Compound VWP Vibrating Wire Piezometer Alcoa of Australia Limited 81

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