mineral residue facilities and water management …

1 MINERAL RESIDUE FACILITIES AND WATER MANAGEMENT STRUCTURES STANDARD

MINERAL RESIDUE FACILITIES AND WATER MANAGEMENT STRUCTURESSTANDARD AND TECHNICAL SPECIFICATIONSVERSION 5, MAY 2019

The El Torito tailings facility at El Soldado, Chile


SectionPage

Number1 Mineral residue facilities and water management structure standard

AA TS 602 001

1. Purpose and Objectives 2

2. Scope 2

3. Planning and Design 3

3.1. Consequences Classifications of Structures (CCS) 3

3.2. Design Requirements for Mineral Residue and Water Containment Facilities 3 - 4

3.3. Design Requirements for SFRMP and Associated Infrastructure 4

4. Implementation and Management 5

4.1. Competent Person 5

4.2. Engineer of Record (EoR) 5

4.3. Technical Review Panel (TRP) 5

4.4. Operational Phase Stewardship 5 - 6

4.5. Engagement and Communication 6

4.6. Closure and Post-closure Phases Stewardship 6

5. Performance Monitoring 7

Appendix 8

2 Standard applicability (specification)AA TS 602 101


2. Applicability 10

3. Exclusions 10

Appendix 11

3 Classification, design criteria, and surveillance requirements (specification)AA TS 602 102


2. Consequence Classification of Structures (CCS) 13

3. Minimum Design Criteria Requirements 13

4. Minimum Surveillance and Inspection Requirements 13

Table 1: Consequence Classification of Structures 14 - 15

Table 2: Minimum Design Criteria for Containment Facilities, Tailings and Water Retaining Dams 16

Table 3: Minimum Design Criteria for Waste Rock Dumps, Stockpiles, Coarse Residue Deposits and Heap Leach Pads 17

SectionPage

Number3 Table 4: Minimum Required Frequency for Surveillance and Inspection of Containment

Facilities, Tailings and Water Retraining Dams 18

Table 5: Minimum Required Frequency for Surveillance and Inspection of Waste Rock Dumps, Stockpiles, Coarse Residue Deposits and Heap Leach Pads

19

Appendix 20

4 Required documents (specification)AA TS 602 103


2. Required Documents 22

Table 2.1: Required Documents for Mineral Residue Facilities and Water Management Structures 23 - 25

Appendix 26

5 Surface flooding risk management plan development and implementation (specification)AA TS 602 104


2. Contents 28

3. Establish the Site Surface Flooding Context 28

4. Characterization of Surface Flooding Risk 28

5. Develop Surface Flooding Risk Management Plan (SFRMP) 29

6. Implementation and Monitoring 29

7. SFRMP Review, Updating, and Change Management 29

8. Emergency Preparedness and Response 29

Appendix 30

6 Definitions 31 - 37

CONTENTS

Cautionary Statement to Third PartiesThis document sets out an internal technical standard that applies to Anglo American’s managed businesses and operations as set out in section 2 (“Scope”). Deviations from this standard may be permitted in exceptional circumstances and subject to an internal approval process.This information is made available to third parties for information purposes only. It is not intended to amount to any form of advice, recommendation or information on which any party is intended to rely. Reference is made to Anglo American plc’s annual report and other public disclosures by RNS that we may make from time to time. Neither Anglo American plc nor any of its subsidiaries (the “Anglo American Group”) nor any of its directors, officers, employees or consultants assumes any responsibility or liability for the accuracy, content or completeness of the information contained in this document. No warranties, promises and/or representations of any kind, express or implied, are given, nor is any duty of care assumed by the Anglo American Group or by any of its directors,

officers, employees or consultants as to the nature, standard, completeness, accuracy or otherwise of the information provided in this document nor to the suitability or otherwise of the information to any particular circumstances. No warranties, promises and/or representations of any kind, express or implied, are given, nor is any duty of care assumed by the Anglo American Group or by any of its directors, officers, employees or consultants, as to the compliance with, or enforcement of, any policies, guidelines or technical standards adopted by the Anglo American Group. To the fullest extent permitted by applicable law, neither the Anglo American Group nor any of its or their directors, officers, employees or consultants accepts responsibility or liability for any loss or damage of whatever nature (direct, indirect, consequential, or other) whether arising in contract, tort or otherwise, which may arise as a result of use of or reliance upon any information contained in this document.

Document to be referenced as: Anglo American (2019): Anglo American Technical Standard AA TS 602 001 Mineral Residue Facilities and Water Management Structures Standard and Technical Specifications. Original version released February 2014.

MINERAL RESIDUE FACILITIES AND WATER MANAGEMENT STRUCTURES STANDARDTechnical Specification AA TS 602 001

Surveying operations at the El Torito tailings facility at El Soldado, Chile


This Group Technical Standard defines the minimum requirements for Mineral Residue Facilities (MRFs) management, water containment, and water diversion structures management in Anglo American, throughout the life-cycle, from site selection and early studies, through design, operation and to post-closure.

2. SCOPEThis Standard relates to the siting, safe design, operation and closure of all mining and mineral process wastes or by-products storage facilities and deposits, as well as water containment and diversion structures, at either greenfield or brownfield projects and operations, including those that are either removed, relocated or being reprocessed. This Standard also covers the requirements of the preparation and implementation of Surface Flooding Risk Management Plans (SFRMPs).

This Standard applies to all tailings dams, water dams, and mineral waste dumps and stockpiles, either temporary or permanent, as described in AA TS 602 101, that are found at Anglo American Group managed businesses and operations, including contractors when involved in activities covered under this Standard. The Standard also applies to diversion structures and workings necessary to protect Group employees, property and infrastructure from surface flooding and potential inrush of water, snow, ice, and mudslides.

1. PURPOSE AND OBJECTIVES

Technical Standard AA TS 602 001

Dayna Meredith, Environmental Technician at Gahcho Kué Mine in Canada, takes a water sample from Kennady Lake


3.1 Consequences Classifications of Structures (CCS)

3.1.1 This Group Technical Standard defines the minimum requirements for Mineral Residue Facilities (MRFs) management, water containment, and water diversion structures management in Anglo American, throughout the life-cycle, from site selection and early studies, through design, operation and to post-closure.

3.1.2 The CCS evaluation shall be completed by an interdisciplinary team, formally documented by the Engineer of Record (EoR), and approved by the Head of Mineral Residue Facilities (MRF).

3.1.3 The CCS ratings shall be reviewed, and the rating updated based on the review, on an annual basis, with changes to be approved by the Head of MRF.

3.1.4 For mineral residue facilities with a CCS rating of “Major”, or a rating of “High” due to potential human or environmental impacts (on or off property), either a dam breach analysis and inundation study (for containment facilities) or a run-out analysis (for dumps and stockpiles) shall be undertaken to quantitatively estimate area of influence, Population at Risk (PAR), Potential Loss of Life (PLL), and potential additional impacts per the CCS consequence types. The results of these analyses, which shall be completed under both “Induced” and “Sunny day” failure scenarios, shall inform and support the CCS ratings.

3.1.5 For structures with all other CCS ratings, the Head of MRF shall determine if a detailed dam breach and inundation study, or run-out analysis, is necessary to be completed.

3.1.6 Emergency Response Plans (ERPs) and Emergency Preparedness Plans (EPPs) shall be informed by inundation maps or impact area maps, from dam breach analyses and waste dumps run-out analyses, and incorporating stakeholders’ interests and concerns, in accordance with Anglo American Social Way requirements.

3.2 Design Requirements for Mineral Residue and Water Containment Facilities

3.2.1 All MRFs and their appurtenant structures shall meet or exceed the minimum design criteria detailed in Tables 2 and 3 of AA TS 602 102. Where differences in design criteria exist between this Standard and local, regional, or national legislations or codes of practice, the more stringent criteria shall apply.

3.2.2 Where two or more containment structures are associated with the same tailings storage facility or water management reservoir, each structure shall be designed based on its own site-specific conditions and its own CCS evaluation.

3.2.3 Where tailings storage facilities or water retaining dams have a fully enclosed layout (such as a ring dike or closed perimeter dike), there shall only be one set of design criteria for the containment structures, based on the highest CCS rating determined around the facility.

3.2.4 Where two facilities (containment structures or dumps / stockpiles) are adjacent to each-other, within the area of inundation or run-out influence of one another, or share a common structure, dam breach analyses, run-out analyses,

and CCS ratings shall include potential impacts from one facility onto the other.

3.2.5 Comprehensive alternative analyses for site selection, facility layout, disposal methods, operation alternatives, and closure options shall be completed, documented, and evaluated at project design stages, as per Investment Criteria by Stage (ICbS) requirements.

3.2.6 Designs shall suit facility and mine requirements, be cost-effective, have the lowest CCS and lowest risk possible, incorporate social and environmental performance standards, minimise water and energy use, and be designed for closure while considering minimum long term post-closure liabilities and potential for useful land usage at the end of mine life.

3.2.7 Dewatered or filtered mineral residue deposition alternatives, or a hybrid of such methods, shall be included in all mineral residue disposal option analyses from the onset, at least at Opportunity, Concept, and Pre-Feasibility A stages, as per ICbS.

3. PLANNING AND DESIGN



3.2.8 Where the Life of Mine (LOM) exceeds a MRF’s life, total and final capacity requirements and final footprint of the MRF shall be estimated and considered when evaluating impacts and developing an integrated mine plan.

3.2.9 Designs shall include the necessary infrastructure for each MRF, for their construction, commissioning, operation and maintenance, as well as emergency ingress, egress and related emergency support and communication equipment (for daytime and night-time unwanted events).

3.2.10 The Owner’s team for each design phase of a project shall include input from at least one Competent Person with sufficient mineral residue knowledge to manage or co-manage the scope of work required, and be accountable for meeting the requirements of this Standard.

3.2.11 The design team for each phase of a project shall be competent, fully cognizant of this Standard, approved by the Owner’s team representative, and be capable of fulfilling the mineral residue design requirements of the project.

3.2.12 The project team shall ensure that there is full design integration between the different plant, mining and MRF discipline areas, as well as environmental, social and sustainable development aspects and that battery limits and responsibilities are well defined.

3.2.13 Given the evolving and dynamic nature of mineral residue facilities and their designs, a formal change management process shall be developed and adhered to in respect of material design, construction, and operational issues for all MRFs.

3.3 Design Requirements for SFRMP and Associated Infrastructure

3.3.1 Each Operation shall have a SFRMP in place, prepared and signed off by a Hydrological or Hydraulics Engineer (internal or external to the Group) and accepted by the General Manager (GM) or designate, with technical content updated as deemed necessary by the responsible person, and the emergency contacts updated annually.

3.3.2 The SFRMP and the design of associated infrastructure shall be based on sufficiently up-to-date and reliable climatic and hydrologic data, as obtained from weather stations and instrumentation at or near the site that have been calibrated and monitored regularly.

3.3.3 Each Operation shall have a map identifying all catchment and sub-catchment basins, with surface runoff flow directions, overlaying a topographic map of the mining property which includes both mine operation infrastructure and public infrastructure.

3.3.4 Storm events and resulting surface floods within the property boundaries shall be calculated for various return period increments, up to and including the PMP (Probable Maximum Precipitation), as outlined in Technical Specification AA TS 602 104.

3.3.5 Inundation maps shall be prepared for each storm event noted in AA TS 602 104, and overlapped or compounded (where necessary), with tailings and water dam breach analyses, snow avalanches, ice jams build-ups, debris or mud flows.

3.3.6 The level of protection of Operational infrastructure from surface flooding shall be based on cost-benefit analysis and the design storm events agreed and

signed-off by the GM. Where the employee loss of life due to surface flooding or inrush (into open pit, surface or underground mine workings) is considered a potential outcome of an extreme unwanted event, the level of flood protection selected shall be more stringent, commensurate with the gravity and catastrophic nature of the estimated consequence.

3.3.7 Storm water management facilities shall be designed such that they maximize, where possible, the capture and storage of surface runoff, as long as diversion and containment facilities are built for that purpose, and retention of water from extreme rainfall events, snow melt and spring freshet does not add undue risk to the operation.

3.3.8 The SFRMP shall reflect the current risk management and emergency response to floods across the mine site, and shall identify any diversion structures that need to be constructed in the future to achieve the level of risk accepted and signed-off by the GM.

3.3.9 Separation and segregation of process, impacted and non-impacted site water shall be evident in design and operation, and maximized across the entire property (refer to the Water Management Standard), including diversions around open pits and surface mine workings with sediment control dams, polishing ponds, and energy dissipation structures being designed as per technical specifications AA TS 602 102 and AA TS 602 103.

3.3.10 Concept development, design verification and preparation of the SFRMP shall be completed in accordance with the technical specification AA TS 602 104.



4. IMPLEMENTATION AND MANAGEMENT4.1 Competent Person

4.1.1 Each Operation with at least one MRF having a CCS rating of “Major” or “High” shall have a Competent Person assigned on site, in charge of the construction and / or operation of such facility. A Competent Person may be shared by several facilities or operations, depending on the complexity of the sites, distances, logistics, and the amount of work expected in that position.

4.1.2 The Competent Person shall implement and monitor the Standard and the Critical Controls at the respective MRF to which they are assigned.

4.1.3 The Competent Person shall ensure proper completion, sign-off, and control of the required documents, as noted in AA TS 602 103.

4.1.4 SFRMPs shall be prepared and signed off by an experienced Civil Engineer with Hydrology or Hydraulics background (internal or external to the Group). For risks associated with snow avalanches, ice build-up, debris flow, or natural slope failures / mudslides, the Head of MRF shall appoint or confirm that a suitable specialist is engaged to prepare or assist with preparation of relevant document sections and calculations, in these particular specialty areas.

4.2 Engineer of Record (EoR)

4.2.1 Each operation shall appoint an EoR for each MRF.

4.2.2 The EoR appointment letter shall clearly stipulate roles, responsibilities and authorities of both the Operation and the EoR.

4.2.3 Where an MRF includes more than

one dam or containment structure, the EoR shall be appointed for the entire MRF, including appurtenant structures (such as spillways, water management system, sedimentation ponds, pump-back systems, cyclone stations, etc.).

4.2.4 The EoR appointment letter shall clearly stipulate roles, responsibilities and authorities of both the Operation and the EoR.

4.2.5 The EoR shall be contracted by the Operation and report to the Competent Person on site, which could be the mineral residue manager or person responsible for the construction and operation of the MRFs.

4.2.6 For tailings facilities, fine residue facilities, and water-retaining dams, the EoR shall conduct an on-site training workshop for key site and operations personnel at least once per year, to impart to site personnel a full understanding of design requirements and key construction and operational parameters to achieve those requirements.

4.2.7 Change management between two EoRs at any given facility shall include, as a minimum, a one month overlap in service contracts to ensure outgoing EoR has sufficient time to transfer all documentation and knowledge about the facility to the incoming EoR, to complete a smooth and uninterrupted transition between the two firms.

4.3 Technical Review Panel (TRP)

4.3.1 Each Business Unit shall have an appointed independent TRP (TRP) for their MRFs.

4.3.2 The TRPs shall be appointed jointly by the Head of MRF and the BU.

The Head of MRF shall approve in writing the composition of the TRPs and their Terms of Reference (ToR), to ensure independence, and proper technical specialty coverage related to the complexities of the structure(s).

4.3.3 The TRP contract shall clearly stipulate TRP member roles, responsibilities and communication authorities.

4.3.4 TRPs shall meet as often as the TRP deems necessary depending on project or operational complexity, risk profile, or urgency of recommendations or issues at hand. The frequency of meetings shall be at least annually for those BUs with Operations that have one or more MRF rated as having a “Major” or “High” CCS rating.

4.3.5 TRP members shall be kept informed of the risk mitigation measures either delayed or implemented based on the risk register, and incidents or non-compliance issues that may have arisen in between reviews, or since the last TRP meeting.

4.3.6 The TRP shall report directly to the General Manager (GM) of the Operation, with copies of reports submitted to the BU, and to the Head of MRF.

4.3.7 Change management within the membership of the TRP, when and as necessary, shall be based on membership rotation - one member at a time, to ensure knowledge transfer to the new or incoming TRP member by the Panel members that are already in place. Simultaneous replacement of all TRP members shall be avoided.

4.4 Operational Phase Stewardship

4.4.1 The financial and human resources needed to support continued mineral

residue facilities management and governance shall be maintained. Operating and capital costs, and human resource needs, are included in relevant business planning processes.

4.4.2 All plant, equipment and infrastructure used in the handling, deposition and management of mineral residues shall be appropriately maintained, fit for purpose, and operated to ensure that each facility is constructed and developed in accordance with the design and permit conditions.

4.4.3 Where a mine plan or mineral extraction process changes during the operational phase, the impacts on the mineral residue properties, production rate, and facility operating plan shall be re-evaluated and any new risks identified and appropriately managed. The design, equipment selection and operating procedures shall be amended to suit the changes and, if necessary, the authorities informed and permits revised.

4.4.4 All changes shall be documented and approved by the Competent Person and the EoR, adhering to the formal change management process. The TRP shall be made aware of all changes deemed material by the EoR or the Operation.

4.4.5 Where changes in design or operational procedures are needed, they shall be completed, approved and signed-off by the EoR. Documentation of such changes shall include consideration of implications of the change for the full life-cycle of the facility in question, and shall be included in the Annual Dam Safety Inspection report or the Annual Continuation report (see AA TS 602 103).



4.4.6 Performance monitoring systems shall be put in place to ensure that the facility is constructed and operated in accordance with the design, operating manual, permit conditions and closure objectives. Unexpected changes in environmental, operational or structural behaviour shall be investigated and remedied as early as possible, involving the EoR, to proactively and effectively manage change, and to minimize potential long term liabilities.

4.4.7 The safety and stability of all MRFs shall be reviewed according to the requirements set in AA TS 602 102, together with the results of the social targets and environmental compliance indicators to be reported to the Head of MRF on an annual basis, as part of the annual request for information on CCS ratings and risk levels.

4.4.8 The frequency of monitoring, inspection and surveillance of MRFs shall be consistent with the CCS rating, and completed according to the requirements set in AA TS 602 102.

4.4.9 During the construction phase of a facility, which may extend through to the end of the operational phase of the life-cycle, appropriate site supervision shall be in place to ensure that each facility is built in accordance to design and permit conditions. A Competent Person shall be appointed to supervise the construction of the facility, starting from the early phase of site preparation. This shall extend into the commissioning phase where the design and the operating plan demand more specialised management.

4.4.10 Where a Competent Person is not present on site in charge of the facility operation, a more frequent involvement of the EoR (beyond set minimums in AA TS 602 102) is required to support the site management team in conducting regular

monitoring and surveillance of the facility, and this shall be reflected in the EoR appointment letter for such Operations, until a Competent Person is in place.

4.4.11 Quality Assurance tests and documentation during start-up and construction shall be signed off by a Competent Person, representing the EoR. The EoR shall verify and confirm in writing that the design criteria and design requirements are met, thereby satisfying design intent.

4.4.12 Where a MRF is operated by a third party contractor (outsourced operation), the contract documents shall be reviewed for technical scope and content by the Head of MRF or a delegate, with written approval provided prior to sign-off and execution of the contract. Legal and commercial reviews of such contracts shall be undertaken at Operation and BU level.

4.4.13 SFRMPs shall be assigned an owner at the Operation level, responsible for the plan’s management, updates and related employee training, as well as inspection of diversion channels and structures at least twice a year, that is before and during the wet season.

4.5 Engagement and Communication

4.5.1 Engagement and communication shall be planned and undertaken at least annually with community, regulators, and other stakeholders taking into account risks and actual and anticipated changes such as demographics, regulations, and land use particularly downstream of MRFs, and considering interests and concerns of stakeholders. The nature and extent of ongoing engagement and communication will be directly related to the level of interest and concern, as well as complexity of the MRF and actual and potential social and environmental risks.

4.6 Closure and Post-closure Phases Stewardship

4.6.1 Progressive rehabilitation shall be maximized and undertaken during the operational phase in accordance with the closure plan, drawing down on closure funds and reducing post-operational efforts, expenditures, and risks.

4.6.2 All plant, equipment and infrastructure required in the decommissioning, rehabilitation, closure and after-care of each facility shall be appropriately managed to ensure that the facility is closed in accordance with the design and permit requirements.

4.6.3 Facility closure design criteria and requirements, including monitoring, inspection and surveillance, shall meet, as a minimum, the requirements set in AA TS 602 102.

4.6.4 In situations where the Closure Plan is not prepared by the EoR, it shall be reviewed and approved by the EoR for aspects related to the stability and safety of the MRF.

4.6.5 Surface flooding risk management in a post-closure condition shall be designed such that minimum human intervention is necessary and diversion and containment structures have built-in redundancies to withstand such extreme climatic events over long periods, in perpetuity.

4.6.6 All design, operation and closure documentation for each facility shall be stored appropriately, readily accessible and available whenever required for up to 10 years after permanent closure of the facility.



5. PERFORMANCE MONITORING5.1 Each structure shall have its own set

of assessments and reports, as per the requirements set in AA TS 602 103; exceptions include where several small size structures are replicated across the property, having the same CCS ratings, design criteria and operational processes.

5.2 Structures with a CCS rating of Insignificant, Minor, or Moderate shall review document requirements with the Competent Person at the Operational level and the EoR.

5.3 Performance monitoring of quality Standard implementation shall be completed through set governance processes and shall include, as a minimum, the following evaluations:

• Quality of design, construction, operation and closure of facilities;

• Quality of required technical documentation, including sign-off, as outlined in AA TS 602 103;

• Quality of design, implementation, reporting and verification of critical controls, as applicable and relevant to each structure;

• Quality of monitoring, surveillance and governance processes;

• Appointment of the Competent Person;

• Appointment and proper engagement of EoR; and

• Appointment and proper engagement of TRP.

• Availability of quality documentation updated annually and implementation of SFRMP, including semi-annual structural inspections, review

of annual training material and training workshop participation.

5.4 Required documents shall be made available for audits and inspections.


Artisan fitter Kagiso Matlhomancho working on the UHDMS plant project at Sishen Iron Ore Mine in South Africa


APPENDIX A: REFERENCED DOCUMENTS

APPENDIX B: RECORD OF AMENDMENTS

Document number Previous number(s) Title

AA TS 000 001 New document Master List of Definitions

AA TS 601 001 New document Water Management Standard

AA TS 401 001 New document Geotechnical Standard for Underground Excavations and Slope Stability

AA TS 602 101 New document Mineral Residue Facilities and Water Management Structures Standard - Standard Applicability

AA TS 602 102 New document Classification, Design Criteria, and Surveillance Requirements for Mineral Residue Facilities and Water Management Structures, Specification

AA TS 602 103 New document Required Documents for Mineral Residue Facilities and Water Management Structures, Specification

AA TS 602 104 New document Surface Flooding Risk Management Plan Development and Implementation, Specification

Issue 0: GTS 18 New document, February 2011.

Versions 1,2: GTS 18 Standard, minor references updated, October 2012.

Version 3: GTS 18 Standard complete revision (new standard) by Caius Priscu. Internal review and comments by: T. Verbeek, M. Motselebane, P. Renner, D. Cameron, G. Mabula, C. Mapani,T. Gardner, L. Pohl. External reviewers: K. Lyell - K. Lyell Consulting Engineer, South Africa; K. Seddon – ATC Williams, Australia; A. Small – AMEC, Canada; H. McLeod – Klohn Crippen Berger, Canada. Released in February 2014.

Version 4: Revised Standard design criteria updates by Caius Priscu and Todd Martin, new template format applied. Content of GTS 15 Surface Flooding Standard (retired) and part of GTS 16 Inrush Standard (retired) were assimilated into the current standard and associated technical specification AA TS 602 104, December 2016.

Version 5: Updated document format by Caius Priscu, May 2019.


STANDARD APPLICABILITYTechnical Specification AA TS 602 101

Overview of the main wall of the Las Tórtolas tailings dam at Los Bronces, Chile

10 MINERAL RESIDUE FACILITIES AND WATER MANAGEMENT STRUCTURES STANDARDTech reference section 2 - AA TS 602 101

1. Purpose and Objectives

The purpose of this Technical Specification is to stipulate and clarify the structures and facilities to which the Mineral Residue Facilities and Water Management Structures Standard AA TS 602 001 (hereafter noted as “the Standard”) is applicable, and those to which it is not applicable.

2. Applicability

The Standard applies to all dams and containment structures, temporary or permanent, that meet either of the following criteria:

• Their height is equal to or greater than 2.5 m (as measured vertically from lowest foundation level to highest final approved crest elevation); or

• Their maximum containment volume could be at any given time, including process and meteoric water, equal to or greater than 25,000 cubic meters (liquid, solids, or a mix).

This Standard applies to all waste rock dumps, stockpiles, heap leach pads, slag, earthen materials or fill dumps, temporary or permanent, which meet either of the following criteria:

a) Their height is equal to or greater than 5.0m (as measured vertically from lowest foundation level to highest final approved top platform or crest elevation); or

Their maximum volume could be, at any given time, equal to or greater than 50,000 cubic meters.

For structures that do not meet the criteria noted herein (i.e., of smaller size), the Mineral Residue Facilities (MRF) team shall decide, together with the responsible Competent Person and the Engineer of Record (EoR), on the

minimum requirements applicable. This shall be based on sound engineering principles and on the Consequence Classification of Structures (CCS) rating (as per AA TS 602 102), in an effort to minimize associated risks. Structures of lesser size or CCS rating are by no means totally exempt from this Standard, and professional judgement shall be applied.

The specific types of structures and facilities to which the Standard applies include the following:

• Overburden stockpiles and waste rock dumps

• Spoils, discards, reject and processed kimberlite dumps

• Smelter waste, slag piles, and heap leach pads

• Stockpiles (low or high grade ore) and fill or earthen materials

• Gypsum and industrial mineral dumps and stockpiles

• Conventional slurry, thickened, paste, dry stack or filtered tailings (wet / dry deposition)

• Co-disposed mineral residue (e.g. tailings and waste rock, fines and coarse discards, etc.)

• Surface and underground backfill

• Sludge and sediment containment facilities from process, water treatment plants, or runoff

• Water retaining dams for fresh, contact, non-contact or impacted waters

• Containment structures for storm water, return water, sedimentation or polishing ponds

• Dams, dikes and embankment structures for water diversion and / or flood protection

• Appurtenant structures for water management in and around water storage and mineral residue facilities (contour / drainage channels, spillways, gates, decant towers, discharge structures, energy dissipators)

• Conveyance structures for water and / or slurry

Surface flooding issues for which this standard is applicable are as follows:

c) Surface flooding of property from runoff and extreme precipitation events in and around the property and adjacent catchment basins;

d) Surface flooding risks associated with tailings and water dam breach analyses, snow avalanches, ice jams build-ups, debris or mud flows

e) Storm water management;

f) Inrush to mine openings and work areas

3. Exclusions

The following structures and facilities are excluded from the application of the Mineral Residue Facilities and Water Management Structures Standard:

a) Seabed disposal of mineral residue;

b) Domestic, demolition and other industrial wastes including hydrocarbon-contaminated soils (Anglo Environmental Way);

c) Hazardous wastes / substances / chemicals (SHE Way);

d) Site selection and sizing of waste rock dumps and heap leach pads (AA TS 401 001 Geotechnical Standard for Underground Excavations and Slope Stability;

e) Water security, water quality, water efficiency, water management and water treatment (Water Management Standard, AA TS 601 001);

f) Surface and groundwater supply, management and resources (Water Management Standard, AA TS 601 001);

g) Responsible water usage and water savings strategies (Water Management Standard, AA TS 601 001); and

h) Emergency planning, crisis manuals, government and community engagements (Anglo Social Way).

b)





AA TS 401 001 New document Geotechnical Standard for Underground Excavations and Slope Stability

AA TS 601 001 New document Water Management Standard

AA TS 602 001 AA GTS 18 Mineral Residue Facilities and Water Management Structures Standard

AA TS 602 102 AA GTS 18 (appendix) Classification, Design Criteria, and Surveillance Requirements for Mineral Residue Facilities and Water Management Structures, Specification

AA TS 602 103 AA GTS 18 (appendix) Required Documents for Mineral Residue Facilities and Water Management Structures, Specification

AA TS 602 104 AA GTS 15 (retired)

AA GTS 16 (retired)

Surface Flooding Risk Management Plan Development and Implementation, Specification

Inrush (retired)

AA TS 601 001 AA GTS 21 Water Management Standard

Anglo American Social Way

Anglo American Environmental Way

Anglo American SHE Way

Version 1: New document format. Content based entirely on select technical requirements extracted from GTS 18 Mineral Residue Management, Version 3, dated February 2014. This update prepared by Caius Priscu and Todd Martin, December 2016.


Tech reference section 2 - AA TS 602 101

CLASSIFICATION, DESIGN CRITERIA, AND SURVEILLANCE REQUIREMENTSTechnical Specification AA TS 602 102

Operators Patricio Guajardo and Carlos Vasquez supervising operations at the Las Tórtolas tailings dam at Los Bronces, Chile



The purpose of this technical specification is to provide required framework to be used for evaluating the Consequence Classification of Structures (CCS) ratings, minimum design criteria requirements, and minimum surveillance and inspection requirements for mineral residue facilities and water management structures, stipulated within the Mineral Residue Facilities and Water Management Structures Standard (hereafter noted as “the Standard”).

2. Consequence Classification of Structures (CCS)

The Consequence Classification of Structures (CCS) framework is provided in Table 1. This framework shall be used to evaluate the CCS rating for each and every mineral residue facility and water containment structure in the Group that is subject to the Standard applicability, as presented in technical specification AA TS 602 101.

3. Minimum Design Criteria Requirements

Minimum design criteria requirements are outlined in Tables 2 and 3 as follows:

• Table 2 – containment facilities, tailings dams, and water retaining dams

• Table 3 – waste rock dumps, stockpiles, coarse residue deposits, and heap leach pads

4. Minimum Surveillance and Inspection Requirements

Minimum requirements for surveillance and inspection are outlined in Tables 4 and 5 as follows:

• Table 4 – containment facilities, tailings dams, and water retaining dams

• Table 5 – waste rock dumps, stockpiles, coarse residue deposits, and heap leach pads stockpiles, coarse residue deposits, and heap leach pads


Processing operator Aline Oliveira at Minas Rio, Brazil


ANGLO AMERICAN OPERATIONAL RISKMANAGEMENT (ORMP) RISK MATRIX -ADAPTED FOR MINERAL RESIDUE AND WATER CONTAINMENT FACILITIESMANAGEMENT

CONSEQUENCE CLASSIFICATION OF STRUCTURES (CCS) RATING FOR MINERAL RESIDUE AND WATER CONTAINMENT FACILITIES NOTES 1 and 2

(Where an unwanted event has more than one ‘Consequence Type’, choose the ‘Consequence Type’ with the highest rating)Applies to tailings and water retaining dams, and containment facilities with H > 2.5 m or V > 25,000 m3

Applies to waste rock dumps, stockpiles and heap leach pads with H > 5 m or V > 50,000 m3

Consequence Type 1 - Insignificant 2 - Minor 3 - Moderate 4 - High 5 - Major

FinancialSee NOTE 3

No disruption to operation.

Losses < 0.01% of AnnualRevenue & Total Assets

Brief disruption to operation.

0.01% < Losses < 0.1% of Annual Revenue & Total Assets

Partial shutdown of operation.

0.1% < Losses < 1.0 % of Annual Revenue & Total Assets

Partial loss of operation.

1.0 % < Losses < 5.0 % of Annual Revenue & Total Assets

Substantial or total loss of operation.

Losses > 5.0% of Annual Revenue & Total Assets

HumanImpacts

Employee Safety & Health

(on property)First aid case Medical treatment case Lost time injury Permanent disability

or single fatalityNumerous permanent disabilities

or multiple fatalities

PAR (Population at Risk) - Public,

off propertyNone Temporary only 10 or fewer 100 or fewer Greater than 100

PLL (Potential Loss of Life) - Public,

off propertyNone PLL highly improbable PLL is possible but not expected 1 to 10 Greater than 10

Occupational Health Exposure to health hazard resulting in temporary discomfort

Exposure to health hazard resulting in symptoms requiring

medical intervention and full recovery (no lost time)

Exposure to health hazards / agents (over the OEL) resulting in reversible impact on health (with lost time) or permanent

change with no disability or loss of quality of life

Exposure to health hazards / agents (significantly over the OEL) resulting in irreversible impact on health with loss of quality of life or single fatality

Exposure to health hazards / agents (significantly over the OEL) resulting in irreversible impact on health with loss of

quality of life of a numerous group / population or multiple fatalities

TABLE 1: CONSEQUENCE CLASSIFICATION OF STRUCTURES (CCS)



Consequence Type 1 - Insignificant 2 - Minor 3 - Moderate 4 - High 5 - Major

Environment & Infrastructure

Environmental aspects

Lasting days or less; limited to small area (< 1 km2); receptor of low significance / sensitivity (industrial area); no long term

losses (less than a week)

Lasting weeks; reduced area (< 5 km2); no environmentally sensitive species / habitat); no significant loss or deterioration of habitat; restoration or compensation

in kind is highly possible

Lasting months; impact on an extended area (< 10 km2); area with some environmental sensitivity

(scarce / valuable environment); restoration or compensation

in kind is highly possible

Lasting years; impact on sub-basin or area < 20 km2; environmentally sensitive environment / receptor (endangered species / habitats); restoration or compensation in kind is possible but impractical

Permanent impact; affects a whole basin or region > 20 km2;

highly sensitive environment (endangered species, wetlands,

protected habitats); restoration or compensation in kind impossible

Public and private infrastructure

(excluding mine site)

Low economic losses to the region; area contains limited

or no infrastructure.

Losses to recreational facilities, seasonal workplaces

and infrequently used transportation routes.

High economic losses to the region, impacting public infrastructure, transportation

and commercial facilities.

Very high economic losses to the region, affecting important public

infrastructure or services (e.g., highways, power lines, railways, water supply, commercial and

industrial areas, storage facilities of dangerous substances)

Extreme losses affecting major or critical public infrastructures

(highways, bridges, railways, power lines, water supply

mains, large commercial and industrial areas, storage facilities

of dangerous substances)

Social / Communities Minor disturbance of culture / social structures

Some impacts on local population, mostly repairable. Single stakeholder complaint

in reporting period

Ongoing social issues. Isolated complaints from community

members / stakeholders

Significant social impacts. Organized community protests threatening

continuity of operations

Major widespread social impacts. Community reaction affecting business continuity. “License to operate” under jeopardy

Reputation Minor impact; awareness / concern from specific individuals

Limited impact; concern / complaints from certain groups

/ organizations (e.g. NGOs) within local communities.

Local impact; local / regional public concern, adverse publicity

localized within regional and neighbouring communities.

Suspected reputational damage; local / regional / national

public concern and reactions

Noticeable reputational damage; national / international public attention and repercussions

TABLE 1: CONSEQUENCE CLASSIFICATION OF STRUCTURES (CCS)...CONT

NOTE 1: When CCS evaluations are undertaken, both “Sunny day” and “Induced” failure modes shall be included in the dam breach and inundation studies.

NOTE 2: CCS ratings shall be evaluated irrespective of the probability of occurrence of an unwanted event, i.e. Likelihood column of the Risk matrix is completely ignored. Consider the maximum reasonable potential consequence of the selected unwanted event, irrespective of its probability of occurrence.

NOTE 3: This matrix refers to the ORMP matrix values. For BU or Group level financial impact values, please refer to AA_RD_02_22 IRM RISK MATRICES document. Financial consequences include all potential financial losses, from government fines and clean-up costs, to reconstruction, legal costs, and community compensations.

LEGEND: PAR (Population at Risk) = Total number of people from within the public (outside mine property) who would be directly exposed to water, tailings, debris flow or waste rock runout, assuming they took no action to evacuate. PAR shall be used solely for estimating the CCS and not for estimating actual potential loss of life from an unwanted event. Impacts from potential surface water or groundwater contamination on population to be included (such as potential impacts on drinking water sources, etc.)

PLL (Potential Loss of Life) = Incremental number of people from among the PAR (defined above) that would potentially lose their life in case of an unwanted event taking place, even after emergency response and preparedness plans have been in place and activated.

Incremental number is defined as the additional potential loss of life caused by a dam breach / structural failure / loss of containment / surface or groundwater contamination compared to the same climatic event occurring without the dam breach or structural / containment failure or loss.



CCS RATING FOR CONTAINMENT FACILITIESApplies to containment structures, tailings & water retaining dams with:

H > 2.5 m or V > 25,000 m3

Area Parameters Insignificant Minor Moderate High Major Observations

Flood DesignLevels1

IDF – Inflow Design Flood (for operating facilities) 1:100 1:500 1:1,000 1:5,000 1:10,000 or PMF

Flood events consider AEP (annual exceedance probability) on top of normal operating water levels. The rainfall event with the most detrimental effect for the specific facility is to be used (e.g., 12, 24, 48 or 72 hours). For certain geographic regions, rainfall events calculated for 7, 30 and 60 days or longer may need to be verified as well. Where applicable, an equivalent inflow from minimum 1:10 year snowpack must be added.

For well-defined ring dikes or fully closed containment facilities, the PMF (Probable Maximum Flood) would refer to direct precipitation and PMP (Probable Maximum Precipitation) assuming no other amount of water enters the facility (from runoff, avalanches, topographic highs, or similar, etc.); i.e. the catchment basin is the facility itself. NOTE: PMP and PMF have no associated AEP value.

EDF – Environmental Design Flood (for operating facilities) – “no spill” or “zero discharge” climatic event requirements

1:10 1:50 1:100 1:200 1:200

IDF – Inflow Design Flood (for operating facilities) for contour /

diversion channels, contact or non-contact waters

1:10 1:10 1:20 1:20 1:50

IDF - Inflow Design Flood (for closed facilities) 1:500 1:1,000 1:10,000 or PMF 1:10,000 or PMF 1:10,000 or PMF

EarthquakeDesignLevels

EDGM – Earthquake (EQ) Design Ground Motion (for

operating or closed facilities)1:500 1:1,000 1:10,000 or MCE 1:10,000 or MCE 1:10,000 or MCE

EDGM value to be justified using FMEA risk analysis, based on societal norms and acceptable risk levels. In regions with significant and / or complex tectonic and seismic activities, deterministic approaches may be used to derive MCE (Maximum Credible Earthquake) or selection of design criteria, in which case it would need to be justified based on technical evaluations, societal norms and acceptable risk levels. NOTE: MCE has no associated AEP value.

Slope Stability Analyses –

Safety Factors2

Static FoS > 1.3 (operating) & 1.5 (closed) Includes end-of-construction condition before filling (for new structures)

Pseudo-static FoS > 1.1 (operating) & 1.2 (closed) Includes end-of-construction condition before filling (for new structures)

Dynamic (post-earthquake) FoS > 1.1 (operating or closed) Includes end-of-construction condition before filling (for new structures). Assume full

dynamic analysis with post-liquefaction conditions.

Static liquefaction potential FoS > 1.3 (operating or closed)Required for certain situations where low consolidation levels are attained in tailings / slimes / sand deposition, or where high rate of rise is used. Laboratory or in situ piezocone testing (or similar) required to support the evaluation.

Full or partial rapid drawdown FoS > 1.2 (operating) & 1.3 (closed) Where frequent drawdown conditions exist, higher safety factors may be required.

TABLE 2: MINIMUM DESIGN CRITERIA FOR CONTAINMENT FACILITIES, TAILINGS AND WATER RETAINING DAMS


1Freeboard requirements above the IDF or EDF pond levels to be determined on a facility-specific basis.

2Minimum Factors of Safety (FoS) to be evaluated considering both drained and undrained shear strength. Undrained shear strength analyses are required for all upstream tailings dams designs, with geotechnical parameters supported by laboratory testing and / or piezocone in situ testing. Minimum FoS shall be at least 1.3 considering undrained shear strengths, and 1.5 considering drained shear strengths (both strength cases applicable for operating and closed facilities).


CCS RATING FOR WASTE DUMPS, STOCKPILES, COARSE RESIDUE DUMPS AND HLPsApplies to structures with H > 5.0 m or V > 50,000 m3

Area Parameters Insignificant Minor Moderate High Major Observations

Surface Water Management Design levels

IDF – Inflow Design Flood (operating or closed facilities) for contour / diversion / perimeter channels around the dump, for contact or non-contact waters

1:10 1:20 1:50 1:100 1:200

Flood events consider AEP (annual exceedance probability). The rainfall event with the most detrimental effect for the specific facility is to be used (e.g., minimum for 12, 24, 48 or 72 hours). For certain geographic regions, rainfall events calculated for 7, 30 and 60 days or longer may need to be verified as well. Where applicable, an equivalent inflow from minimum 1:10 year snowpack must be added. For sediment control ponds, see Table 2.

The EoR shall consider designing water, snow and ice management structures including rock drains, water control structures and energy dissipators, pore pressure relief zones, flow-through or drainage zones, groundwater relief or catchment wells and snow / ice thawing diversion workings.

Time-dependent behaviour of the fill material (such as rock breakage and degradation, internal blinding effects, geochemical activity or combustion) shall be taken into considerations at all design levels.

Additional surface water, drainage, surface impact water, groundwater, sediment control, debris, snow and ice controls

As determined by EoR

EarthquakeDesignLevels

EDGM – Earthquake (EQ) Design Ground Motion (for

operating or closed facilities)1:500 1:1,000 1:10,000 or MCE 1:10,000 or MCE 1:10,000 or MCE

EDGM value to be justified using FMEA analyses. In regions with significant and / or complex tectonic and seismic activities, deterministic approaches may be used to derive MCE (Maximum Credible Earthquake) or selection of design criteria, which would need to be justified based on technical evaluations, societal norms and acceptable risk levels.NOTE: MCE has no associated AEP value.

Slope Stability Analyses –

Safety Factors

Static (dump face / shallow stability) FoS > 1.0 (operating) & 1.1 (closed)

The degree of uncertainty in the available information, engineering parameters, site and foundation characterization, operating and QA practices in the field, hydro-geochemical processes and environmental constrains need be taken into account when deciding on safety factors beyond minimum requirements. The higher the CCS rating, the more restrictive the requirements.

Static (overall / global stability)l FoS > 1.3 (operating) & 1.5 (closed)Considerations must also be given to potential settlements and allowable deformations (short term and long term) of the dump / stockpile, required equipment and personnel access, and future closure activities.

Seismic (pseudo-static or dynamic analyses) FoS > 1.1 (operating) & 1.2 (closed) Where pseudo-static analyses yield a FoS of 1.1 or less, and the CCS of the structure

is High or Major, a full dynamic stress-deformation analysis is required.

TABLE 3: MINIMUM DESIGN CRITERIA FOR WASTE ROCK DUMPS, STOCKPILES, COARSE RESIDUE DEPOSITS AND HEAP LEACH PADS



MINIMUM INSPECTION FREQUENCIES BASED ON CCS RATING FOR CONTAINMENTFACILITIES, TAILINGS AND WATER RETAINING DAMS

Applies to all dams, dikes and embankments with H > 2.5 m or V > 25,000 m3

ResponsibleLevel

SurveillanceTask

Insignificant Minor Moderate High Major ObservationsFormalReport

EoRPresence

BUPresence

T&SPresence

Operations

Routine visual site inspection (short version

inspection forms)

Quarterly Monthly Every two weeks Weekly Daily

Visual walk-around or drive along facilities, looking for abnormal conditions. Short version checklist and photos to be used. No formal report required beside the checklist.

No No No No

Routine visual monitoring

inspection (long version

inspection forms)

Twice per year Quarterly Every two months Monthly Every two weeks

This frequency or more often, as dictated by instrumentation monitoring reading frequency. Long version checklist (with photos) to be completed. Monitoring data to be collected and provided to EoR for interpretation.

NoSee Clause

4.4.10 in Standard

No No

Quarterly inspections

As required by legislation


As required by legislation Yes Yes

Formal report to be prepared by EoR. Report to be reviewed and approved by BU Champion and submitted to regulators, as per local legislation.

Yes Yes Optional Optional

Annual Dam Safety Inspections Yes Yes Yes Yes Yes

Annual DSI report, to be completed by EoR and to include results and interpretation of findings in routine inspections and quarterly reports. Shall include interpretation and impact of monitoring data and trends.

Yes Yes Yes Optional

BU

Technical Review Panel (TRP) for mineral residue

facilities

As deemed necessary by

the TRP


the TRPEvery two years Annually Annually

TRP members may decide to meet more frequent, as they deem necessary. Several MRFs within a BU may be reviewed in the same session. TRPs may request further detailed dam safety reviews by external engineering firms, depending on design or operational changes, major climatic changes (after a major flood or earthquake), or as requested by the EoR

Yes Yes Yes

As deemed necessary by T&S, or requested by the BU

T&S GroupProjects

Mineral Residue Facilities team or designate – site visits and

/ or audits

Every five years or as deemed

necessary by T&S


necessary by T&S

Every three years Every two years AnnuallyT&S dam safety inspections or audits may take place at the same time as the TRP meetings or ABAS audits. T&S to determine timing.

Yes Yes Yes Yes

TABLE 4: MINIMUM REQUIRED FREQUENCY FOR SURVEILLANCE AND INSPECTION OF CONTAINMENT FACILITIES, TAILINGS AND WATER RETRAINING DAMS



MINIMUM INSPECTION FREQUENCIES BASED ON CCS RATING FOR CONTAINMENTFACILITIES, TAILINGS AND WATER RETAINING DAMS

Applies to all dams, dikes and embankments with H > 2.5 m or V > 25,000 m3

ResponsibleLevel

SurveillanceTask

Insignificant Minor Moderate High Major ObservationsFormalReport

EoRPresence

BUPresence

T&SPresence

Operations

Routine visual site inspection (short version

inspection forms)

Quarterly Monthly Every two weeks Weekly Daily

Visual walk-around or drive along facilities, looking for abnormal conditions. Short version checklist and photos to be used. No formal report required beside the checklist.

No No No No

Routine visual monitoring

inspection (long version

inspection forms)

Twice per year Quarterly Every two months Monthly Every two weeks

This frequency or more often, as dictated by instrumentation monitoring reading frequency. Long version checklist (with photos) to be completed. Monitoring data to be collected and provided to EoR for interpretation.

NoSee Clause

4.4.10 in Standard

No No

Quarterly inspections



As required by legislation Yes Yes

Formal report to be prepared by EoR. Report to be reviewed and approved by BU Champion and submitted to regulators, as per local legislation.

Yes Yes Optional Optional

Annual Dam Safety Inspections Yes Yes Yes Yes Yes

Annual DSI report, to be completed by EoR and to include results and interpretation of findings in routine inspections and quarterly reports. Shall include interpretation and impact of monitoring data and trends.

Yes Yes Yes Optional

BU

Technical Review Panel (TRP) for mineral residue

facilities


the TRP


the TRPEvery two years Annually Annually

TRP members may decide to meet more frequent, as they deem necessary. Several MRFs within a BU may be reviewed in the same session. TRPs may request further detailed dam safety reviews by external engineering firms, depending on design or operational changes, major climatic changes (after a major flood or earthquake), or as requested by the EoR.

Yes Yes Yes

As deemed necessary by T&S, or requested by the BU

T&S GroupProjects

Mineral Residue Facilities team or designate – site visits and

/ or audits


necessary by T&S


necessary by T&S

Every three years Every two years AnnuallyT&S dam safety inspections or audits may take place at the same time as the TRP meetings or ABAS audits. T&S to determine timing.

Yes Yes Yes Yes

TABLE 5: MINIMUM REQUIRED FREQUENCY FOR SURVEILLANCE AND INSPECTION OF WASTE ROCK DUMPS, STOCKPILES, COARSE RESIDUE DEPOSITS AND HEAP LEACH PADS







AA TS 602 101 AA GTS 18 (appendix) Mineral Residue Facilities and Water Management Structures Standard – Standard Applicability, Specification



AA GTS 16 (retired)


Inrush (retired)

Version 1: New document format. Content based entirely on select technical requirements extracted from GTS 18 Mineral Residue Management, Version 3, dated February 2014. This update prepared by Caius Priscu and Todd Martin, October 2016.



REQUIRED DOCUMENTSTechnical Specification AA TS 602 103

The solar panels installed on the Las Tórtolas tailings facility at Los Bronces, Chile



The purpose of this technical specification is to list the 25 documents required for mineral residue and water containment structures referenced in the Mineral Residue Facilities and Water Management Structures Standard AA TS 602 001, hereafter referred to as “the Standard”. The Surface Flooding Risk Management Plan (SFRMP) is required on an Operation-specific rather than structure-specific basis, so is not included in the listed documents herein – refer instead to AA TS 602 104.

2. Required Documents

The following list of 25 required documents is mandatory for facilities covered by the Standard (refer to AA TS 602 101) and having a Major or a High CCS rating (refer to AA TS 602 102). In some instances, the contents of one listed document may be included in another, in which case separate documents are not required; cross-referencing between the listed 25 shall then suffice.

Structures with an Insignificant, Minor or Moderate CCS rating require only select few key documents, as agreed between the Mineral Residue Facilities (MRF) discipline in T&S and the Operation. Guidance is provided in the Self-assessment evaluation spreadsheet for the Standard implementation.

Each structure shall have its own set of assessments and reports; exceptions include where several small size structures are replicated across the property, having the same CCS ratings, design criteria and operational processes. Documents without proper sign-offs are not considered complete.

The only two documents requiring approval by the MRF discipline in T&S are the CCS rating evaluation report (Document No. 2) and the composition and appointment of the Technical Review Panel (TRP) (Document No. 12).

Surveying operations at the El Torito tailings dam at El Soldado, Chile


Doc No. Title Prepared by Approved By / Accepted By Details and Clarifications

1 EIA (Environmental Impact Assessment) report EoR / Project Engineering team

Ops / As per Anglo American Project Way / Environmental

Way / Social Way

The latest version submitted to the local Government department responsible for environmental approvals shall be provided.

For cases where no EIA was required by the regulatory authorities, the Environmental Management Plan (EMP – Document No. 16) or equivalent shall be provided.

2 CCS (Consequence Classification of Structure) report EoR / Ops Head of MRF discipline, T&S

The CCS report shall be reviewed and approved by the Head of MRF (or delegate). All AA mineral residue facilities shall follow the same CCS rating system (see AA TS 602 102) for consistency.

CCS classification shall follow the adjusted ORMP risk matrix and definitions as included in AA TS 602 102 (Insignificant, Minor, Moderate, High, and Major). The CCS report shall be reviewed (and updated, if necessary) annually to ensure upstream or downstream conditions within the potential areas of influence did not change, therefore impacting the CCS rating from previous year.

3 Design criteria memorandum EoR OpsDesign criteria must meet minimum requirements as outlined in AA TS 602 102, and minimum requirements for the applicable local legislation. The most stringent criteria shall apply. Design criteria must be up to date, and used as part of the key controls at the operation.

4 Design report(s) EoR Ops

The design report documentation shall be up to date, and fully reflective of the current design / construction of the facility. Design addenda reports shall clearly reference the preceding design documentation. Design reports shall include all supporting design assumptions, design and operating parameters, and geotechnical analyses, including stability and seepage analyses as a minimum. Design reports shall include, or make reference to supporting reports, outlining site investigation / characterization aspects, including as a minimum: geological, geotechnical, geochemical, hydrology, hydrogeology, seismicity, mineral residue geotechnical and geochemical characterization, and climate.

5 Short term deposition plan EoR / Ops Ops The short term deposition plan, usually covering a 6 months to maximum 3 years outlook, shall match the EIA / permit in place, as well as the Master Plan (see item #6).

6 Master deposition plan (based on LOM) EoR / Ops Ops

This document shall demonstrate how mineral residue deposition over the Life of Mine (LOM) would fit within the property boundaries and topographic restrictions, and be safely stored and operated within the approved design and permitted context, while maintaining the overall closure plan objectives, philosophy and method. The final projected outline or layout in a post-closure condition must be shown as well.

7 Detailed engineering reports & construction drawings EoR Ops

Must include construction specifications and detailed engineering drawings, including plan views and cross-sections. Must be reflected within the permit and the OMS manual. The status of specifications and drawings (design, issued-for-tender, and issued-for-construction) shall be indicated.

8 Construction and as-built reports EoR / Ops Ops

Must include construction or deposition reports, changes from design or permit requirements, as-built drawings annotated with changes from design, QC (Quality Control) documents, and QA (Quality Assurance) documents. Must clearly show any deviations from design drawings or concepts. Must be updated either annually, or with any new dam lift or waste dump lift completion, or as often as required by local legislation – whichever requirement is the most stringent. Reports shall include statement of confirmation from the designer / EoR that construction satisfied design intent.

9 Internal inspection reports Ops Ops Must reflect routine visual inspections carried out internally, at a frequency specified in AA TS 602 102.

10 Quarterly reviews (or semi-annual) Ops / EoR OpsThe reports must include a site visit by the EoR accompanied by the Ops representative. Must include a compilation and evaluation of internal inspection reports (during the period prior) as well as a compilation of any monitoring data. Reports must be prepared at a frequency specified in AA TS 602 102.

TABLE 2.1: REQUIRED DOCUMENTS FOR MINERAL RESIDUE FACILITIES AND WATER MANAGEMENT STRUCTURES




11 Annual Dam Safety Inspection (DSI) Report EoR GM

The DSI report shall be completed annually by the EoR and shall include (as a minimum) a detailed site visit of facilities, photographic record, review of structural condition of the facility, verification of compliance with the design criteria and permit requirements, confirmation of operations taking place in line with the OMS manual, evaluation of instrumentation readings and effectiveness of the monitoring system, overall evaluation of the structural and environmental performance of the containment structures and water management structures, and recommendations for action items to implement investigations, re-design work or remedial measures. A review with the Ops and BU representatives of the facility risk matrix shall be included. The report shall either reference Document No. 15 (noted in this table) or append the most recent stability analyses and confirm these to be sufficiently up to date as to be representative.

12TRP (Technical Review

Panel) Reports for Mineral Residue Facilities

TRP GM / T&STRP reports must include as a minimum: a site visit report and photographic record (where site visits are required); reviews and analyses of topics tabled and discussed or tasks at hand included in the scope of work or identified in the field. A report shall be issued pursuant to each TRP meeting, whether on site, or if reviews were conducted remotely”.

13 T&S review / audit report MRF Discipline, T&S Ops A site visit report shall be provided, with a focus on key risks and recommendations for mitigations of those risks.

14 Water balance EoR / Ops OpsA water balance of the facility shall to be included as part of the site-wide water balance, and shall to be updated at least once a year. The water balance shall include both a schematic chart showing flow inputs and outputs / losses, as well as a report with backup documentation (data used).

15 Stability and seepage analyses report (updates / continuation reports) EoR Ops These reports shall be updated on a regular basis at key milestones, or depending on the rate of rise of the facility,

during any performance reviews, changes in geometry, or following an incident or major climatic event.

16 EMP (Environmental Management Program) report EoR / Ops Ops / S&SD

An EMP report shall be prepared and updated as deemed necessary by the Ops / BU in agreement with local legislative requirements and in line with the current permits and community requirements. The EMP shall outline as a minimum the approved limits for water quality (surface and groundwater), air and noise emissions and other potential environmental impacts, environmental monitoring plans, sampling, laboratory testing, instrumentation, certificates for instrumentation calibration and quality assurance processes. The EMP shall also contain a risk matrix related to key risks from an environmental perspective and corresponding mitigation measures, unless already included in document No. 21, noted below.

17 OMS (Operation, Maintenance and Surveillance) manual EoR / Ops Ops

This is a key document that outlines procedures for the safe operation, maintenance and surveillance of tailings facilities, water management facilities and mineral residue dumps and stockpiles over the life of the mine and through closure. The OMS manual should be available upon commissioning, providing clear and concise framework for actions at site and operation level. The level of detail in the OMS manual should reflect site requirements and provide a solid base for demonstrating due diligence. An OMS manual shall be prepared by the EoR, incorporating input from the Ops and BU. OMS manuals shall be reviewed and updated (as required) no less frequently than annually.

18

ERP (Emergency Response Plan)

(internal emergency plan of actions) EoR / Ops Ops / GM

An ERP manual shall be prepared jointly by the EoR, and Ops / BU, including Sustainability / Environmental and HSE Managers at Ops levels, and shall be approved, as a minimum, by the GM, the Operations Manager, and the SHE Manager. And the Superintendent of the facility. The ERP shall outline key emergency roles and responsibilities of the staff, in order of action priority, as well as required notifications, communication directory, contact information, and action items to be undertaken. The contacts within the ERP’s communication directory shall be updated at least twice a year. For Major and High CCS-rated structures, ERPs shall be based on the potential failure modes identified for the structures (see Document No. 21), and as reviewed by the TRP. TARPs (Trigger Action Response Plans) shall identify trigger levels either in instrumentation, measured parameters or visual observations, for which certain pre-defined actions are to be initiated. Areas of influence upon which ERPs are based shall consider sunny day and induced failure scenarios for dam breach analyses, slope instability run-out and debris flows, or avalanche simulations, and are to be determine for structures and residues deposited in either wet or dry conditions.

TABLE 2.1: REQUIRED DOCUMENTS FOR MINERAL RESIDUE FACILITIES AND WATER MANAGEMENT STRUCTURES CONT




19

EPP (Emergency Preparedness Plan)

(external emergency plan of action, also known at times as Crisis Manual)

EoR / Ops Ops / GM / GSA

An EPP manual shall be prepared jointly by the EoR / Ops / BU, under the guidance and direction of the Social Performance team, including input from Sustainability / Environmental, Community Relations, Public Relations and HSE Managers at Ops levels, and shall be approved by the GM, the Head of Engineering / Discipline, S&SD and Communications departments. The notification contacts within the EPP shall be verified and updated (where required) at least twice a year. Local and regional agencies shall be involved in the process and provide input into the document.

For a Major CCS rated structure, or a structure with a rating of High due to Human Impact criteria or Environmental criteria, EPPs shall be based on the inundation / run-out maps, derived from detailed dam breach analysis and inundation studies. Live drills / simulations shall be carried out at least once every 5 years, or as recommended by the TRP. For CCS ratings of Moderate and below, an EPP is not required, unless the TRP and / or the Ops / BU recommends it. A TARP document shall be included with every EPP.

20 Closure Plan EoR / Specialist engineering firm / Ops Ops

A facility-specific closure plan shall be prepared and kept up to date, and revised if mine planning and / or mineral residue deposition plans change. The closure plan shall be in consistent with the long term deposition planning (Item n° 6). If specialist mine closure consultants are used for closure plan development, EoR input must be provided. The level of detail of the Closure Plan and corresponding financial closure liabilities shall be evaluated to a detail level dictated by the local regulatory framework in each country. The Anglo American Closure Toolbox shall be used as a guiding document in preparing Closure Plans.

21 Risk Assessment report EoR / Ops Ops

The Risk Assessment (RA) report shall be prepared for each mineral residue facility and water retaining dam. FMEA (Failure Modes and Effects Analyses) methodologies (or equivalent) shall be used for all Major and High consequence rated structures. Tailings dam RAs must be reviewed by the EoR for completeness as part of the annual DSI reporting (item n°11). TARPS (Trigger Action Response Plans) shall be developed and updated by EoR in agreement with the Operation and BU Champion. Risk registers for each structure / facility shall be submitted annually to the Head of MRF, in the required format.

22 Confirmatory letters of appointment Ops / BU Ops / T&SConfirmatory letters of appointment shall be prepared and executed (signed) to ensure an EoR, a contractor or operator (where applicable), and a Mineral Residue TRP have been dully appointed and their scope of work, contract duration, responsibilities, and authorities are clearly defined.

23 Permit compliance report summary Operation Contractor / Ops Ops

Every Operation shall prepare a summary report outlining compliance (or non-compliance) status with all permit requirements related to the MRF(s) and its appurtenant structures (spillways, settling, polishing ponds, etc.). This report shall be prepared by the Ops, together with the Operating Contractor (where applicable) and reviewed by EoR and BU (Sustainable Development and Head of Engineering representatives). Where non-compliance is noted, it shall be mentioned why, what happened, consequences and any additional risks, who was informed, actions to be implemented, by whom and by when and any associated budgets allocated to rectify the non-compliance situation.

24 Applicable local legislation Ops / BU Ops / BU This document shall be a compilation of current local regulations applicable to the design, operation and closure of the facility. Related laws and regulations shall be included.

25 Incident registerEoR / Ops

Ops / BUOps / GM / BU

An up to date incident register shall be kept at all facilities, updated with a description of the incident(s) as they occur. It shall include a description of the incident, the extent (accident or failure), photographic record, and technical reasons behind the occurrence as reflected based on design criteria and / or regulatory requirements and / or governance practice or irregularities. Rehabilitation measures, activities, audits and review reports and drawings shall be included to ensure technical aspects have been addressed and are properly controlled.

Incidents (accidents or failures) must be reported, as an absolute minimum, to the GM of the Ops, the EoR and the MRF team, as per AA policies and procedures, depending on the incident level and complexity.

TABLE 2.1: REQUIRED DOCUMENTS FOR MINERAL RESIDUE FACILITIES AND WATER MANAGEMENT STRUCTURES CONT










AA GTS 16 (retired)


Inrush (retired)

Version 1: New document format. Content based entirely on select technical requirements extracted from GTS 18 Mineral Residue Management, Version 3, dated February 2014. This update prepared by Caius Priscu and Todd Martin, October 2016.



SURFACE FLOODING RISK MANAGEMENT PLAN DEVELOPMENT AND IMPLEMENTATIONTechnical Specification AA TS 602 104

Construction work underway at Minas Rio tailings dam, Brazil



The purpose of this specification is to provide minimum requirements and define the framework to be used for the development and implementation of the Surface Flooding Risk Management Plan (SFRMP) at each Operation, as stipulated in AA TS 602 001.

2. Contents

1. Establish the site surface flooding context

2. Characterization of surface flooding risk3. Develop Surface Flooding Risk

Management Plan (SFRMP)4. Implementation and monitoring5. SFRMP review, updating, and

change management6. Emergency preparedness and response

3. Establish the site surface flooding context

3.1 Prepare maps delineating all catchment and sub-catchment basins that report to or overlap the mining property, indicating surface runoff flow directions, topography, geomorphology, land uses, runoff characteristics, and mine property boundaries.

3.2 Characterize site climate, hydrology, topography and runoff characteristics, and define flood events for each catchment basin covering a range of return periods and event durations. Return periods shall span as a minimum the following: 20 years, 50 years, 100 years, 200 years, 500 years, 1,000 years, 5,000 years, and 10,000 years. Probable Maximum Flood (PMF) events shall also be estimated. Event durations shall span a sufficient range to fully capture flooding risks and identify the most critical event duration, specific to the site context and local climate conditions,

for a given return period (or PMF) event.

3.3 Identify and characterize potential flood hazard sources within and around the property, such as creeks, rivers, lakes, ocean, tailings and water retaining dams, water reservoirs, snow avalanche tracks, debris flows, mudslides, flash flooding, river ice-jams, in-rush to open pit and underground workings, and other flood-related geo-hazards relevant to the terrain, climate, and mine site context and setting.

3.4 Develop intensity-duration-frequency rainfall curves (hyetographs) to derive extreme storm runoff hydrographs. Include snowmelt and rain-on-snow events under applicable climatic settings.

3.5 Identify on-site and off-site people, facilities and infrastructure at potential risk under flooding. Where applicable, flood risk is to be evaluated for the following sources of exposure:

• Mining areas (open pits, openings to underground workings – shafts, portals, vent raises, unsealed exploration boreholes)

• Roads, railways, bridges, culverts

• Emergency access and egress roads

• Process plant facilities, crusher, conveyors, yards, office buildings

• Mineral residue facilities (tailings facilities, fine residue deposits, coarse residue deposits, waste rock dumps, heap leach pads)

• Water retaining dams

• Water supply and water treatment facilities

• Utilities (pipelines, power lines)

• Pipeline corridors (ore, tailings, recycled water, etc.)

• Employees (on site)

• Communities (off site)

• Off-site infrastructure

• Runoff diversion and collection works

• Environmentally / culturally sensitive areas

• First aid and emergency areas

• Fresh / potable water sources

• Hazardous / non-hazardous waste and chemicals storage facilities

4. Characterization of surface flooding risk

4.1 Prepare flood inundation maps, inclusive of mine and surrounding infrastructure, and areas with potential life at risk (on-site and off-site), considering various return period events and event durations, generated from pertinent flooding hazard sources.

4.2 Based on the flood inundation maps, prepare a matrix indicating flood event return period (with annual probability) versus consequences, considering affected infrastructure. Consequences considered and costed, shall include, as a minimum:

• Temporary business interruption for duration of submergence and of post-event recovery

• Permanent structural damage requiring reconstruction

• Loss of equipment; carried away by the flow of water or buried under sediment

• Loss of power supply

• Release of polluted water to river systems or environmentally sensitive land, with associated breach of law, and

• Reputational damage

4.3 Where potential loss of life or injuries to employees or the public could occur, particularly due to drowning (from water, mud flow, surface or underground in-rush events, or other flood-related geo-hazards), flood protection workings shall be designed to the most stringent criteria.

4.4 A formal and comprehensive risk analysis and evaluation shall be conducted for the applicable flood risk exposures identified in the section above. Determine, with the current controls in place, whether the possible flooding related to these exposures poses an acceptable risk, or whether risk reduction / mitigation is required, on an exposure-specific basis.


5. Develop surface flooding risk management plan (SFRMP)

5.1 Evaluate flood protection and flood mitigation works across the entire property for the various storm / flood events and for various return periods.

5.2 Cost estimates shall be completed for implementing infrastructure protection and mitigation works for each of the flood events across the property.

5.3 Design criteria for the various specific flood protection workings shall be selected following a cost-benefit analysis; that is the cost incurred to construct and maintain the diversion works versus the reduction of damage costs (mining infrastructure, production stoppage, etc, as noted in 2.2) for the same flood event. Transform annual exceedance probability of the flood event to cumulative probability considering the life of mine (LOM) or remaining risk exposure. For closure flooding risks, cumulative probabilities will consider the extended closure time frame and corresponding duration of risk exposure. Transformation from annual to cumulative flood event probabilities shall be estimated as follows:

P[ƒ]i=1– (1– P0)i

Where:

5.4 Determine design criteria that define acceptable flooding risk (or protection level) for each vulnerable asset. Different design criteria (or return period events) may be found appropriate for flood protection / mitigation of various infrastructure or operation areas, considering vulnerability-specific consequences.

5.5 Document the site context, surface flooding risk, and the risk management plan in a Surface Flooding Risk Management Plan (SFRMP) report. Alternatively, these could be incorporated into the Operation’s overall Water Management Plan.

5.6 Design criteria and flood protection levels shall be signed off by the GM.

6. Implementation and monitoring

6.1 Surface flooding risk reduction / mitigation measures shall be designed by person(s) competent in hydrology and hydraulics engineering. Designs for constructed works shall include statement of design criteria, construction quality assurance / quality control plan, detailed specifications and construction drawings, and a monitoring and maintenance plan. As-built reports shall be prepared documenting the constructed works and achievement of design intent.

6.2 A monitoring system shall be in place, to track / check: a) The climatic conditions which might precede an extreme storm event; b) The integrity and maintenance of water containment structures e.g. pipelines and flood mitigation controls; and c) That tailings and water dams representing potential flood hazards are performing in accordance with their design and Operation, Maintenance and Surveillance (OMS) manuals, in accordance with AA TS 602 001.

6.2 For monitoring the state of water containment structures and flood mitigation controls: a) Routine inspections shall

be conducted to ensure that structures e.g. pipes, reservoirs, berms, trenches, dam walls, bridges, tunnels, are in a good condition, and b) A maintenance and inspection program shall be in place, associated with monitoring the condition of the structures. Threshold levels shall be set for the monitored parameters, where applicable, which would “trigger an alarm” if exceeded, to enable early detection of potential risks.

6.4 Routine quarterly inspections shall be carried out, and they shall be planned and scheduled at critical times, three of the four inspections each taking place before, during and after the rainy / wet seasons, depending on site-specific climatic conditions.

7. SFRMP review, updating, and change management

7.1 Each SFRMP shall have an owner, responsible for its content, reviews, updates, implementation, communication, and related training.

7.2 A change management process shall be in place to identify the risks associated with changes in the plan, and to ensure that the SFRMP adapts to incorporate additional controls to manage the “new” or “changed” risks. The process shall define the magnitude of change required to trigger a review and update of the SFRMP.

7.3 The following updates of the SFRMP shall be completed:

1.1.1 Climate data and site hydrology – frequency of updates determined by the Competent Person

1.1.2 Changes in site infrastructure (construction, removal, expansions) – inundation maps reviewed annually and updated, as required

1.1.3 SFRMP updates – no less frequent than once every three years.

8. Emergency preparedness and response

8.1 Emergency response plans specific to identified flooding risks shall be prepared to define on-site actions and mitigations to be undertaken if severe flood events occur, and shall be incorporated into the overall site emergency response plan.

8.2 Emergency response plans shall include both water and tailings floods, as well as debris flows and related geo-hazards noted in Section 1.3.

8.3 The emergency response plan is to be triggered when warning systems, embedded within Trigger Action Response Plans (TARPs) for surface flooding risks, indicate an unsafe situation based on pre-determined indicators. The warning systems shall be linked to the threshold values for the monitored parameters. Typically there will be a series of response levels and escalation within the TARPs, from first response to final evacuation.

8.4 Where there is potential surface flooding impact off-site, an emergency preparedness plan associated with surface flooding risks outside property boundaries shall be developed and embedded into the overall site emergency preparedness plan defining off-site notifications, communications, and actions. Relevant external parties shall also be included in the simulation exercises to ensure they are familiar with requirements. The plan shall include all actions and communication chains associated with warning, first response and evacuation phases of an emergency situation, as well as a repair and recovery plan to restore site operational status as quickly as possible.

8.5 Mock runs of the emergency response plan shall be carried out every year for high risk sites and every two years for moderate risk sites so that responsible and affected parties understand the various responses for various trigger levels, and knows the escape routes.

P[ƒ]i =

=

Probability of flood event occurring in i years

Probability that flood of agiven return period is equalled or exceeded in i years

P0 =

=

Probability of flood occurrence in any one year

Reciprocal of the flood event return period

i =

=

Remaining mine life (in years), or mine closure period

Duration of exposure to flooding risk





AA TS 602 001 AA GTS 18

AA GTS 15 (retired)

AA GTS 16 (retired)

Mineral Residue Facilities and Water Management Structures Standard

Surface Flooding

Inrush (retired)




Version 1: New document prepared in part based on excerpts of GTS 15 Surface Flooding and GTS 16 Inrush technical standards (now both retired). Prepared by Caius Priscu and Todd Martin, December 2016.




Term Definition

AEW Anglo American Environmental Way

AHW Anglo American Occupational Health Way

Ash The burnt by-product from coal thermal power stations or from heat generation equipment

ASW Anglo American Safety Way

BackfillMaterial used to fill in mining voids. In underground mines backfill typically constitutes tailings, but could be mixed with a binder or other materials, including waste rock or other fill materials or binders. In open cast / open pit mines, backfill typically constitutes overburden or waste rock, but could include tailings, slag or other mineral wastes, or a mixed deposition of materials.

BU Business Unit

Coal Discards A coarse by-product from coal processing plants with a caloric value below the limit required by the customer. Such material may be susceptible to spontaneous combustion.

CCS

Consequence Classification of Structures – refers to an established classification protocol for mineral residue deposits and associated containment facilities, including water retaining dams, based on the consequences of a potential failure or loss of integrity (without a necessarily a breach) of the respective structure or facility. CCS provides a useful and consistent basis for determining minimum design requirements, minimum safety management requirements and minimum inspection and surveillance protocols.

Most importantly, CCS assists with understanding public safety, PAR (Population at Risk) and PLL (Potential Loss of Life) within the area of influence, helping to define potential corporate risks and liabilities.

The CCS evaluation uses a modified version of the ORMP (Operational Risk Matrix Protocol) risk matrix (AA RD 02 22 IRM Risk Matrices), included and explained in this Standard, but maintaining the same overall Consequence categories: Insignificant, Minor, Moderate, High and Major.

The CCS analyses are completed independently of the probability of occurrence of the unwanted event that could trigger the failure. CCS is determined based on a number of parameters, as described in the Consequences section of the risk matrix, the area of influence of a slope or debris failure or a dam failure, including preparation of impact area maps, run-out maps and / or inundation maps.

DEFINITIONS


Term Definition

Competent Person

Individual with a recognized engineering degree / registered professional engineer (where jurisdictions include such legislated professional associations, such as Australia, Canada, South Africa, UK, the United States, etc.), with extensive experience in Mineral Residue facility design, construction, operation and closure and related legal, environmental and techno-economic requirements.

Engineering degree would include: Civil Engineering (Geotechnical or Hydraulics), Geological Engineering, or Mining Engineering with specialty in mining geotechnics and / or mineral residue management.

EoR

Engineer of Record (EoR) – typically, the engineering company or entity that is either:

a) The Design Engineer who completed the detailed engineering, construction drawings and specification to construct the structure, or

b) A replacement of the Design Engineer when the latter is no longer available, the company does not exist anymore, or duties of the Design Engineer have been transferred to another engineering company for various reasons, also known in certain reasons as the Continuation Engineer

The EoR appointment shall be completed by the Operation management team, in agreement with the Head of Engineering / Head of Technical of the respective BU, on a term contract with specific roles, responsibilities and authorities (typically over a 3 to 5 year period). Appointment of the EoR shall be based on the qualifications and competencies of its staff, the depth and breadth of knowledge of its engineers and scientists and not primarily on financial considerations.

The EoR shall be the close advisor of the on-site mineral residue manager / superintendent for the structure or facility for which the EoR has been appointed to, and shall maintain close contact and coordination with the delegated contact person at Operational and BU levels. The EoR shall be contracted by the Operation and reports to the Competent Person on site, which could be the mineral residue manager or person responsible for the construction and operation of the facility(ies).

The EoR is typically an engineering firm, company or organization, outside the Group, which includes the various specialties necessary to provide relevant and necessary support to the Operation in the area of Mineral Reside Management. Where the EoR is a subcontractor to a major firm or EPC / EPCM contractor or where the EoR resides within the Group, a special evaluation (technical and legal) must be carried out and appointment approved by Group Mining, Head of Mineral Residue Facilities and Water Management.

EPP

Emergency Preparedness Plan – typically a document that refers to and describes communication and action plan with external stakeholders in case an unwanted event takes place that could potentially impact areas beyond mine property (mainly a dam failure, a water quality impact, a groundwater plume, etc.). The EPP clearly identifies communication protocols with other organizations outside property boundaries, such as communities and residents in potential areas of influence, local and regional government agencies and officers, government departments or officials.

The EPP defines main contact persons for emergency units, logistical units, corporate communications and media communications on and off site (among other) and their backup or replacements. Areas of influence on which EPPs are based on shall be evaluated using FMEA analyses for both “Sunny day” and “Induced” failure modes, dam breach analyses, slope instability run-out and debris flows, or avalanche simulations. They apply to structures and residues deposited either in wet or dry condition.

DEFINITIONS


Term Definition

ERP

Emergency Response Plan – typically a document that refers to and describes the internal action plan in case of an emergency, roles and responsibilities, failure modes, trigger levels, evacuation routes, communication protocols and emergency response team contacts, among other.

Areas of influence, on which ERPs are based on, shall be evaluated using FMEA analyses for both “Sunny day” and “Induced” failures, dam breach analyses, slope instability run-out and debris flows, or avalanche simulations. They apply to structures and residues deposited either in wet or dry condition

Facility Refers to all aspects of a mineral residue deposit, including associated water and sediment management structures

FEL Front End Loading – refers to inputs to project phases, where FEL 0 refers to pre-conceptual phase, FEL1 refers to the conceptual phase, FEL2 for the pre-feasibility phase, and FEL3 for the feasibility phase.

FMEA

Failure Modes and Effects Analyses – refers to a systematic technique of failure analysis of a system or a sub-system. The FMEA activity is completed in a workshop environment with experienced multi-disciplinary team at the table and independent moderator. It helps to identify potential failure modes based on experience with similar structures and processes, based on engineering and common physics of failure logic, and a thorough understanding of failure mechanisms related to geo-engineered structures.

The FMEA is used to evaluate risks, as well as mitigation measures for risk reduction based on the failure mode, either reducing its severity or consequence level, or lowering the probability of failure / occurrence, or both.

FMEAs shall include both “Sunny Day” and “Induced” failure scenarios.

Group Technical Guideline

Group Technical Standards normally have an associated Group Technical Guideline. In some cases these may be public domain documents.

Group Technical Guidelines shall expand on requirements set in the Group Technical Standards, providing more detail including generic documentation, interpretations, and examples of leading practice and support of implementation aspects. A basis for producing Procedures, Work Instructions, Forms and Templates.

Group Technical Standards Group Technical Standards (or GTSs) define minimum requirements to be implemented across the Anglo American Group. They are driven by risk or value-based criteria or are needed to enable governance where a common and consistent approach should be taken across the Group.

Hazardous wasteAny solid or liquid waste(s) that individually or in combination can impact human health and / or the environment through the contamination of air or water, direct skin contact, temperature and / or radiation at levels exceeding toxic or health limits. Some mineral residues have the potential to be classified as hazardous waste depending on local waste classification legislation.

IDM Investment Development Model

DEFINITIONS


Term Definition

Leached material

Ore bearing material (typically oxide) that in some instances has been crushed to a boulder, cobble or gravel size, placed in a vat or on a prepared base overlying a drainage medium and has been saturated with chemical solution to leach out the minerals. The leachate solution is collected from the base of the vat / facility for mineral recovery. The material may be temporarily or permanently placed on these facilities. In the case of temporary or dynamic facilities, the leached material is moved to a more permanent storage facility. Vat leached material is commonly referred to as ripios (refer to heap leach guideline AEW – AA SSD R 2). Many of the leaching processes are conducted over a lined area that allows collection of leachate and protection of the subsurface.

Life-cycles stages

An operation’s life-cycle could include all or some of the following stages (green and brown field projects);

a) exploration,

b) project evaluation (conceptual, pre-feasibility and feasibility studies),

c) project execution (detailed design, construction, commissioning and ramp-up)

d) operation (including care and maintenance, or dormant phase) and

e) closure, (progressive reclamation, decommissioning, demolition, rehabilitation, maintenance, short term and long term after-care and monitoring)

LOM Life of mine

Mineral Residue

All mining and mineral process waste / by-products. This includes mining residues, waste rock, overburden, spoils, discards, reject material, processed kimberlite, stockpiles, tailings, backfill, smelter waste, slag, leached material, water treatment or process sludge, impacted sediments. The material may be in liquid, brine, slurry, paste, dry or solid form.

Mineral residue excludes domestic, medical, industrial and hazardous substances (chemicals).

Mining Waste

Material required to be removed to expose or extract ore bearing strata. This would include overburden or spoil stripped during open cast mining, waste rock from open pit mining, and shot rock from underground mine development and mining areas (e.g. shafts, adits, declines or tunnels).

It excludes topsoil / organic soil layer removal ahead of strip mining or advance of a mineral residue facility, which is strategically stockpiled as a resource for future rehabilitation purposes.

It excludes spoil generated from on and off-site construction work associated with building a mine / plant, which should be handled according to local regulations.

OMS manual

Operation, Maintenance and Surveillance manual – refers to a key document that outlines procedures for the safe operation, maintenance and surveillance of tailings facilities, water management facilities and mineral residue dumps and stockpiles over the life of the mine and through closure. The OMS manual should be available upon commissioning, providing clear and concise framework for actions at site and operation level.

The level of detail in the OMS manual should reflect site requirements and provide a solid base for demonstrating due diligence.

DEFINITIONS


Term Definition

Rejects A low grade by-product from a mineral processing plant often placed on a managed stockpile to allow for future processing / sale.

ResidueThis term is intended to include any by-product or waste from a mining or processing operation and the terms residue or waste can be used inter-changeably for clarity or ease of translation. Where the word ‘waste’ is used, it does not necessarily mean that the material is waste, since many residues contain minerals that are currently uneconomic to recover, but could become a future resource.

Smelter Waste Slag, residue, sludge and flue dust in solid or slurry form, from beneficiation processes such as smelters or furnaces.

SMP Stakeholder Management Plan

SOP Standard Operating Procedure

SSD Safety and Sustainable Development

Stockpiles Strategically placed piles of material that contain fill materials or minerals that may be used, processed, retreated, or sold in future and could include among other high grade ore, low grade ore (discards) and slag.

TailingsGenerally the residue or waste that comes out of the mineral processing plant, transported and / or deposited in dry or wet (slurry) form. Tailings are a fine-grained material product as a result of rock crushing, pre-existing grain sizes or chemical precipitation, remaining after mineral extraction. This includes sands, slimes, ash, rejects, discards and any other plant residue.

Tailings dam A fill structure or embankment that is built to retain tailings and / or to manage water associated with the disposal and/or storage of tailings. Tailings dams can be built using the total tailings or a fraction of them or import fill materials (random, selected, or man-made).

Tailings storage A site where processing wastes are temporarily or permanently stored, not necessarily formed by a dam structure.

Tailings Storage Facility (TSF) Includes the tailings storage, containment embankments, appurtenant slurry and water management structures and associated infrastructure.

T&S Anglo American Technical and Sustainability function, where standard owner and lead author reside.

DEFINITIONS


Term Definition

Mineral Residue TRP

Technical Review Panel (TRP) for mineral residue and water management structures – a group of typically 3 to 6 senior engineers external to the Group, each with a minimum of 20 years’ national and / or international experience, that act as independent reviewers and advisors for each respective BU.

Members of the TRP shall be independent professionals that have not been involved in the design, construction or operational engineering assignments carried out in the last 10 years (minimum) at the mineral facility to be reviewed. TRPs meet as often as they deem necessary (typically on an annual basis) depending on project or operational complexity or urgency of recommendations or issues at hand.

As an absolute minimum, the TRP shall include the following specialist engineers:

• hydrology / hydraulics;

• geotechnical;

• hydrogeology / groundwater / contaminant transport

Depending on local conditions, the type of dam and solids deposition method, and the Consequence Classification of the Structure (CCS) rating, the TRP could also include additional specialist engineers or scientists in the following areas of expertise:

• dam safety and risk management;

• closure planning;

• hydrogeology / groundwater / contaminant transport

• seismic analysis of dams;

• geochemistry;

• tailings rheology, thickened tailings, alternative tailings disposal methods and related mechanical equipment.

TRPs are appointed jointly by Group Mining, Head of Mineral Residue Facilities and Water Management and the Head of Engineering or Head of Technical at BU level. Approval shall be received from the Head of Mineral Residue Facilities and Water Management prior to confirmation of appointments and TRP’s contractual scope of work.

Catchment Basin (Water Management,

Surface Flooding)

The extent of a geographical area or an area of land where all surface water from rain, melting snow, or ice drains and converges to a single point at a lower elevation, usually the exit or outlet of the catchment basin, where the waters join another body of water, or merge with flows from an adjoining catchment basin. The perimeter of the catchment basin is referred to as the catchment divide. Depending on the site-specific conditions, equivalent terms include drainage basin, or watershed (for major rivers).

Debris Flow A fast-moving landslide or moving mass of liquefied, unconsolidated, and saturated solids and fluids, including fine and coarse solids, cobbles, boulders, rocks, as well as natural debris (dead vegetation, etc). Debris flows comprising only mud and water, and lacking gravels and larger sizes, constitute mud flows.

DEFINITIONS


Term Definition

Extreme Storm Event(s)

A single storm event, or consecutive storm events, that could cause extreme harm.

For example, a single storm with a return period of not less than 1 in 100 years of high intensity (< 24 hour duration), or consecutive large storm events with a combined run-off exceeding the single 1 in 100 year event. Risk assessments /design requirements may require consideration of 1 in 500 year, 1 in 1000 year, or greater return period events (1 in 10,000 year) for design purposes.

The reciprocal of the return period (in years) of a storm event represents the annual probability of that event.

Regional Maximum Flood (RMF) or Probable Maximum Flood (PMF) are often defined by local codes of practice, but if not, use should be made of the International Commission for Large Dams (ICOLD) guidelines.

Flash Flood Rapid and potentially destructive flooding of geomorphic low-lying areas: washes, rivers, dry lakes and basins. Flash flooding can occur in arid regions, and may be caused by heavy rain associated with a severe thunderstorm, hurricane, tropical storm, or meltwater from ice or snow flowing over ice sheets or snowfields.

InrushThe unintended / uncontrolled movement of liquid, gas or other substance can enter into the mining workplace (surface or underground) with the potential to create an emergency situation and present a risk to health and safety of workers. Under high pressure, these substances can swiftly flow or release into or within a mine.

Probable Maximum Flood (PMF)

The largest flood that could conceivably occur at a particular location, usually estimated from probable maximum precipitation, and where applicable, snow melt, coupled with the worst flood producing catchment conditions. A PMF has no equivalent annual exceedance probability (AEP).

Probable Maximum Precipitation (PMP)

The greatest depth of precipitation for a given duration meteorologically possible for a given size storm area at a particular location at a particular time of year, with no allowance made for long-time climatic trends (i.e. climate change). A PMP has no equivalent annual exceedance probability (AEP).

Return Period Also known as a recurrence interval (sometimes repeat interval) is an estimate of the likelihood of an event, such as an earthquake, flood or a river discharge flow to occur. The reciprocal of the return period is the annual probability of occurrence / exceedance of the event.

River Ice Jam

Ice jams in rivers can develop near river bends, mouths of tributaries, points where the river slope and flow velocities decrease, downstream of dams and upstream of bridges or obstructions, and where frazil ice and solid ice build-up could develop in cold weather conditions. The water held back by the ice build-up can cause flooding upstream, and if the obstruction suddenly breaks, flash flooding can then occur downstream as well, releasing both water and ice, with massive destructive potential.

Snow Avalanche A rapid flow of snow down a hill or mountainside. Although avalanches can occur on any slope given the right conditions, certain times of the year and certain locations are naturally more dangerous than others. Winter and early spring are times when most avalanches tend to happen.

DEFINITIONS