Australian Centre for Sustainable Mining Practices

Leading Practice and Mine Closure

David Laurence

Australian Centre for Sustainable Mining Practices

With thanks to Graeme McIlveen and Daniel Franks, SMI, University of Queensland

What is Leading Practice?

• the best way of doing things for a given site

• It’s flexible and innovative in developing solutions that match

site-specific requirements.

• It’s about approach and attitude as it is about a fixed set of

practices or a particular technology.

• an evolving target—it is adaptive to changing standards and

situations

• to allow mining companies to maintain their social licence to

operate

Leading Practice Sustainable Development Program for the Mining Industry

The Leading Practice Program provides practical

guidance to the mining industry through handbooks and

workshops

Assist with the implementation of

leading practice

Offering a continual challenge to

the industry and other stakeholders

to improve their social &

environmental performance

Leading Practice Sustainable Development

14 HANDBOOKS PRODUCED TO DATE…

• Community Engagement &

Development

• Managing Acid & Metalliferous

Drainage

• Mine Rehabilitation

• Mine Closure & Completion

• Stewardship

• Biodiversity Management

• Tailings Management

• Working with Indigenous

Communities

• Water Management

• Cyanide Management

• Risk Assessment &

Management

• Hazardous Materials

Management

• Evaluating Performance:

Monitoring & Auditing

• Airborne Contaminants, Noise &

Vibration

The Guide to Leading Practice

The Guide to Leading Practice

• “This new publication provides a single point of reference for information on implementing and improving leading practice principles through the life of a mine by bringing together the major lessons of the leading practice books and case studies from around the world.”

Why Do Mines Close?

Mines close!

• Resource depletion: ideal case

• Economic: cost or price changes

• Reserves and resources: uncertainty or errors

• Transition from open pit to underground

• Geological issues: unpredictability or errors

• Geotechnical problems: instability, stresses and failures, hardness

• Mining technical: rock hardness, errors in choice of technique

• Metallurgy: unpredicted mineralogy effects, errors in choice in technology

• Safety and health: fatal accidents

• Flooding

• Change in corporate ownership or strategy

• Loss of markets

• Community opposition

• Government intervention

• Combination of these reasons or factors

Reasons Why Mines Close

School of Mining

Engineering,

Mine Closures 1981-2005

0%

5%

10%

15%

20%

25%

30%

Reso

urce D

eplete

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rices

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dministra

tor

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Geo

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/geot

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sues

Did

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Low g

rades

Loss

of m

arkets/

downst

ream

Regu

lato

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ent inte

rv.

Flood

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wea

ther/i

nrush

Pro

ductio

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lties

Equ

ipm

ent/t

echni

cal d

ifficultie

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Lack

of e

xplora

tion

Saf

ety

Env

ironm

ent

Poo

r gra

de e

stim

ation

Indu

stria

l relat

ions

Met

allurg

ical

Uncl

assifie

d

Primary Reason for Closure

Perc

en

tag

es o

f C

losu

res

The Impacts

School of Mining

Engineering,

Mine Closures 1981-2005

Primary Environmental Impacts

AMD

Tailings

Open pit voids

Waste dumps

Water quality

Land/soil degradation

Poor rehabilitation

Infrastructure

Underground impacts general

Rivers/creek impacts

Heap leach issues

Slope stability

Heritage issues

Aesthetics

Others

AMD

School of Mining

School of Mining

Engineering,

Tailings

School of Mining

School of Mining

Engineering,

School of Mining

Engineering,

Waste rock dumps

School of Mining

School of Mining

Engineering,

Mine Closures 1981-2005

Socio-economic impacts

40%

21%

12%

10%

7%5% 2% 2%

Employees

Regional/local (businesses

etc)

Indirect employee

Sterilised ore

Loss of investment

Industry image

Death/loss of

community/town

Indigenous opportunities

Employees

Major stakeholders – often neglected

School of Mining

Engineering,

Indigenous community

Failed joint ventures

Trust?

School of Mining

Engineering,

School of Mining

Engineering,

Mine Closures 1981- 2005

Primary OHS Impact

18%9%

9%

9%

18%

36%

Vertical openings

Voids

Subsidence

Landslips

Hazardous materials

Other

Vertical openings

From drill holes to shafts to…

School of Mining

Engineering,

Open pit voids

School of Mining

Engineering,

Subsidence

Block cave & SLC;

Crown pillar collapse

Longwall

School of Mining

Engineering,

Subsidence

School of Mining

Engineering,

Longwall damage

School of Mining

Engineering,

Courtesy A. Waddington & BHP-Billington

Hazardous substances

School of Mining

Engineering,

– Australian legislation and regulation are both national and state-based:• Nine states and territories

• Minerals are reserved to state governments

• Conditions for mine closure and rehabilitation are set at state level

– National laws address national issues such as impact assessment and exports, but not mine closure or rehabilitation directly

• National Environmental Protection Measures, such as for hazardous waste

• National Strategic Frameworks for mining (guidance documents) on Tailings Management, Abandoned Mines (legacy sites) , Water Management and Mine Closure

– State and Territory laws address mining, land use planning and pollution control

• State laws address mining title and conditions, management plans and financial guarantees for mine closure and rehabilitation

• State pollution control regulation is detailed and onerous, with financial penalties not in mining law

Legislative and Policy Requirements for Mine Closure

– Key elements:• Predictability and availability of Policy guidelines

• Consistency and scientific rigor in enforcement

• Resources for enforcement

• Future may lie in risk-based and non-prescriptive approach to regulation

• Being in compliance is mandatory requirement for certification in ISO14001

• Pressure to publish information on closure liabilities in sustainability reporting

– Resources and guidelines:• State Guidelines

• Leading Practice handbooks

• Research and training

Regulatory and Planning Issues for Mine Closure

National Strategic Framework for Mine Closure

The importance of risk and of management of risk as the key management tool

– Critical aspects and impacts of the mining cycle (closure and rehabilitation) are risks to be managed

– They can be managed using new research-based risk methodologies

Closure risks– For the company

• Corporate risk, reputational risk and business risk (liabilities)

• Operational; compliance, environmental liabilities

– For the regulators• Long-term liabilities

• Financial Guarantees [performance guarantees]

– For the community• Economic development and employment issues

• Long-term environmental impacts and liabilities

Planning and Risk Assessment are essential steps in mine closure

PLANNING ISSUES ANDAPPLICATION OF RISK MANAGEMENT

Manage the Risks for Mine Closure

The likelihood that an event will happen and the consequences of that event happening

Our aim is to make ourselves aware of all the risks, to understand all the risks and to manage them systematically– We can develop a ‘risk matrix’ and quantify the risks

– allowing us to rank them, to cost them and to prioritize them

– We can design control strategies for risks, we can insure against them or we can accept them

What are the Risks of Mine Closure and how do we manage them?

Planning, large scale open pit coal mining

Mt Owen Coal Mine, Hunter Valley, NSW

Financial Guarantees, Bonds or Securities are aimed at penalising

failure to adequately rehabilitate closed sites

Form of risk assessment and management

Forms of guarantees: insurance, up-front bonds, bank guarantees

Regulator methodologies are not systematic

Policy guidelines available

FINANCIAL GUARANTEES

[Performance guarantees]

Financial Assurance for Mine Closure

Financial Assurance for Mine Closure

Leading Practice Handbook:Mine Closure and Completion

Domains

Planning principles for each domain

Voids and open pits

– Understanding the long-term geotechnical and hydro-geological behaviour of the pit walls

– Water balance

Waste Rock

– Planning shape – natural and final

– Planning encapsulation and optimization of mass handling

– Water balance and surface hydrology and infiltration

– Run-off and erosion

– Soils and plants: ‘store and release’ example

Mine site domains and elements

Tailings facilities

– Final design and capacity

– Settlement and consolidation

– Outer slopes and surface covers

– Potential for AMD

Processing and Plant site

– Hazardous waste

– Soil contamination

– Demolition and recycling

– Final use

– Heritage aspects

Mine site domains and elements

Leading Practice Handbook:

Mine Closure and Completion

Progressive rehabilitation

Mt Owen Coal Mine, Hunter valley, NSW

Large-scale open pit coal mining in State forest, Hunter Valley, NSW

Variously termed Orphan, Derelict, Abandoned and Legacy sites

Unrehabilitated

Serious risks to public safety

Contaminated land– Health risks

– Environmental impacts

Contaminated waterways– Health risks

– Environmental impacts

Heritage and Tourism issues– Social connection with local communities

– Economic connection with local communities

Closed mines and Legacy Sites

Mining heritage and tourismMt Morgan gold mine, Queensland, and Sovereign Hill gold mine, Victoria

Key Messages

• All mines close and many close prematurely.

• Mine management needs to develop and implement mine closure planning.

• Taking more integrated approach to mine closure planning, and doing it earlier, can achieve effective mine closure and completion, and ameliorate negative effects of unexpected or unplanned closures.

• Community engagement at earliest possible time is essential.

• Goal should be community ownership as community will inherit project eventually.

• Community liaison or advisory groups established specifically for mining project can help operation focus its engagement program.

• Rehabilitation planning and implementation need to take place early and progressively throughout life of mine.

• Leading practice techniques can provide guidance for successful landform design, topsoil usage and revegetation outcomes.

LEADING PRACTICE IN MINE CLOSURE and REHABILITATION

Key Messages• Costing for closure and rehabilitation is essential and tools are available to

calculate realistic costs.

• Risks (to company reputation etc) are significant and are long term in nature and companies can expect to have rehabilitation and closure liabilities long after production has ceased.

• Quantitative and qualitative risk assessment techniques to demonstrate to community and regulators that closure issues have been identified and appropriate security deposit can be calculated.

• Leading practice biodiversity management goes beyond minimising long-term impacts from operations.

• It identifies opportunities for improvement in lease and adjacent areas by introducing innovative and sustainable land management practices.

• Leading practice techniques during operation of mine will reduce potential for long term issues associated with acid mine drainage.

LEADING PRACTICE IN MINE CLOSURE and REHABILITATION

LEADING PRACTICE HANDBOOK:BIODIVERSITY MANAGEMENT

Measuring the height of saplings,

rehabilitated land

University of Newcastle researchers, Mt Owen coal mine, Hunter

Valley, NSW

Ongoing assessment of the success of

rehabilitation

Kidston gold mine, Queensland

Closure: What does it mean to leave a positive legacy?

Leaving a positive legacy means that the region around the mine and the people who live in it are left with assets that have value beyond the life of the mine.

It is not just about mitigating the negative impacts of closure

Assets may take a variety of forms and will not necessarily be physical, economic or fixed in one place.

Mt Leyshon & Agricola – courtesy SMI

The Guide to Leading Practice

The Guide to Leading Practice

The Guide to Leading Practice

New England Sapphires (1990)

New England Sapphires

(2012)

New England Sapphires

• Excellence in enviro management

• Suitable final land use

• Regular information sharing with landowner

• Pay the landowner well

• Invited onto other farms for exploration

• 1979-1999, 5 mines successfully closed

Thank you for your kind attention