16. Rehabilitation and Mine Closure - · PDF fileArmour rock is required for erosion...

Chapter 16

Mount Peake ProjectDraft Environmental Impact Statement

16.

16.1 The Project is expected to disturb a total area of approximately 1,060 habreakdown of area according to individual mine feature. In the context of rehabilitation and closure, these mine features can be broadly separated into two categories:

m

mbe rehabilitated.

The first category comprises the major earthwork mine componentsCombined, these three be approximately 77 ha in area, will remain as an open void and not be rehabilitated.

This leaves a total of approximately 98

Rehabilitation can be separated into two broad phases:

m

mconclusion of oper

Progressive rehabilitation is defined as rehabilitation that can be undertaken through the life of mine.However, arehabilitation of these features is not possible.rehabilitated during the life of mine, however the nature ofprogressive rehabilitation is not feasible. Justification for this position is as follows:

TSF

long term stockpiles

infrastructure

TNG has prepared a Conceptual Mine Closure Plan been prepared consistent with the Western Australian Environmenreleased in 2011.

Chapter 16 – Rehabilitation and Mine Closure


16. Rehabilitation and Mine Closure

BackgroundThe Project is expected to disturb a total area of approximately 1,060 habreakdown of area according to individual mine feature. In the context of rehabilitation and closure, these mine features can be broadly separated into two categories:

mine features that remain on site after closure, essentially in

mine features that are demolished and removed from site at closure, leaving a bare land surface to be rehabilitated.

The first category comprises the major earthwork mine componentsCombined, these three be approximately 77 ha in area, will remain as an open void and not be rehabilitated.



mine features where progressive rehabilitation methods can be applied; and

mine features that are fully operational until closureconclusion of oper

Progressive rehabilitation is defined as rehabilitation that can be undertaken through the life of mine.However, a number of mine features remain in operation until the very end of mine life, so progressive rehabilitation of these features is not possible.rehabilitated during the life of mine, however the nature ofprogressive rehabilitation is not feasible. Justification for this position is as follows:

TSF

ong term stockpiles

nfrastructure

TNG has prepared a Conceptual Mine Closure Plan been prepared consistent with the Western Australian Environmental Protection Authority (EPA) released in 2011.

Rehabilitation and Mine Closure

Mount Peake Project Draft Environmental Impact Statement


Background The Project is expected to disturb a total area of approximately 1,060 habreakdown of area according to individual mine feature. In the context of rehabilitation and closure, these mine features can be broadly separated into two categories:

ine features that remain on site after closure, essentially in

ine features that are demolished and removed from site at closure, leaving a bare land surface to be rehabilitated.

The first category comprises the major earthwork mine componentsCombined, these three features comprise 642 ha or 60% of the total be approximately 77 ha in area, will remain as an open void and not be rehabilitated.



ine features where progressive rehabilitation methods can be applied; and

ine features that are fully operational until closureconclusion of operation.

Progressive rehabilitation is defined as rehabilitation that can be undertaken through the life of mine.number of mine features remain in operation until the very end of mine life, so progressive

rehabilitation of these features is not possible.rehabilitated during the life of mine, however the nature ofprogressive rehabilitation is not feasible. Justification for this position is as follows:

Tailings drequired for the tailings surfac

These ore stockpiles will be constructed according to grade and will largely function as an extension to the ROM. These stockpiles will allow blending of ore into the processing plant. that will be reclaimed towards the end of the mine life. At mine closure, all stockpiles will have been removed and the base pad arearehabilitation

nfrastructure This comprises primary mine infrastructure (process plant, power station, process water damborefield, access roads). closure. There is almost no ability to progressively rehabilitate parts of this infrastructure.

TNG has prepared a Conceptual Mine Closure Plan been prepared consistent with the Western Australian

tal Protection Authority (EPA) released in 2011. The DMP /


Draft Environmental Impact Statement


The Project is expected to disturb a total area of approximately 1,060 habreakdown of area according to individual mine feature. In the context of rehabilitation and closure, these mine features can be broadly separated into two categories:


ine features that are demolished and removed from site at closure, leaving a bare land surface to

The first category comprises the major earthwork mine componentsfeatures comprise 642 ha or 60% of the total

be approximately 77 ha in area, will remain as an open void and not be rehabilitated.

This leaves a total of approximately 983 ha of land that requires rehabilitation



ine features that are fully operational until closure


rehabilitation of these features is not possible.rehabilitated during the life of mine, however the nature ofprogressive rehabilitation is not feasible. Justification for this position is as follows:

Tailings deposition will continue until the site closes. A period of time is then required for the tailings surfac

These ore stockpiles will be constructed according to grade and will largely function as an extension to the ROM. These stockpiles will allow blending of ore into the processing plant. that will be reclaimed towards the end of the mine life. At mine closure, all stockpiles will have been removed and the base pad arearehabilitation.

comprises primary mine infrastructure (process plant, power station, process water dam, rail siding) as well as ancillary infrastructure (accommodation village, borefield, access roads).

There is almost no ability to progressively rehabilitate parts of this infrastructure.

TNG has prepared a Conceptual Mine Closure Plan been prepared consistent with the Western Australian

tal Protection Authority (EPA) / EPA released a revised version of this Guideline in May 2015.







ha of land that requires rehabilitation



ine features that are fully operational until closure


rehabilitation of these features is not possible. Portions of the WRD can potentially be progressively rehabilitated during the life of mine, however the nature ofprogressive rehabilitation is not feasible. Justification for this position is as follows:

eposition will continue until the site closes. A period of time is then required for the tailings surface to dry sufficiently to allow vehicle movement.

These ore stockpiles will be constructed according to grade and will largely function as an extension to the ROM. These stockpiles will allow blending of ore into the processing plant. They will also provide a storage area for low grade ore that will be reclaimed towards the end of the mine life. At mine closure, all stockpiles will have been removed and the base pad area

comprises primary mine infrastructure (process plant, power station, process ) as well as ancillary infrastructure (accommodation village,

borefield, access roads). This infrastructure is required to be operational until mine There is almost no ability to progressively rehabilitate parts of this

TNG has prepared a Conceptual Mine Closure Plan (MCP) been prepared consistent with the Western Australian

tal Protection Authority (EPA) Guidelines for preparing mine closure plansEPA released a revised version of this Guideline in May 2015.



ine features that remain on site after closure, essentially in perpetuity; and




ha of land that requires rehabilitation



ine features that are fully operational until closure, so rehabilitation can only commence at the


Portions of the WRD can potentially be progressively rehabilitated during the life of mine, however the nature of most of the other mine features are such that progressive rehabilitation is not feasible. Justification for this position is as follows:

eposition will continue until the site closes. A period of time is then e to dry sufficiently to allow vehicle movement.

These ore stockpiles will be constructed according to grade and will largely function as an extension to the ROM. These stockpiles will allow blending of ore

They will also provide a storage area for low grade ore that will be reclaimed towards the end of the mine life. At mine closure, all stockpiles will have been removed and the base pad area


his infrastructure is required to be operational until mine There is almost no ability to progressively rehabilitate parts of this

(MCP) for the projectbeen prepared consistent with the Western Australian Department of Mi

Guidelines for preparing mine closure plansEPA released a revised version of this Guideline in May 2015.


The Project is expected to disturb a total area of approximately 1,060 ha. Table 2breakdown of area according to individual mine feature. In the context of rehabilitation and closure, these

perpetuity; and


The first category comprises the major earthwork mine components; the open pit, the WRD and the TSFfeatures comprise 642 ha or 60% of the total Project envelope. The pit, which will


ha of land that requires rehabilitation at


, so rehabilitation can only commence at the


Portions of the WRD can potentially be progressively most of the other mine features are such that

progressive rehabilitation is not feasible. Justification for this position is as follows:



They will also provide a storage area for low grade ore that will be reclaimed towards the end of the mine life. At mine closure, all stockpiles will have been removed and the base pad area will be



for the project (Appendix MDepartment of Mines and Petroleum (DMP) and

Guidelines for preparing mine closure plansEPA released a revised version of this Guideline in May 2015.

. Table 2-2 provides a breakdown of area according to individual mine feature. In the context of rehabilitation and closure, these

perpetuity; and


the open pit, the WRD and the TSFoject envelope. The pit, which will


at closure.





progressive rehabilitation is not feasible. Justification for this position is as follows:



They will also provide a storage area for low grade ore that will be reclaimed towards the end of the mine life. At mine closure, all

will be available for



ppendix M). This MCP has nes and Petroleum (DMP) and

Guidelines for preparing mine closure plans, originally EPA released a revised version of this Guideline in May 2015.

16

2 provides a breakdown of area according to individual mine feature. In the context of rehabilitation and closure, these


the open pit, the WRD and the TSFoject envelope. The pit, which will


Progressive rehabilitation is defined as rehabilitation that can be undertaken through the life of mine. number of mine features remain in operation until the very end of mine life, so progressive




They will also provide a storage area for low grade ore that will be reclaimed towards the end of the mine life. At mine closure, all

available for



This MCP has nes and Petroleum (DMP) and

, originally EPA released a revised version of this Guideline in May 2015.

16-1

breakdown of area according to individual mine feature. In the context of rehabilitation and closure, these


the open pit, the WRD and the TSF. oject envelope. The pit, which will

number of mine features remain in operation until the very end of mine life, so progressive

most of the other mine features are such that

his infrastructure is required to be operational until mine

This MCP has nes and Petroleum (DMP) and

Chapter 16


16.2 The key rehabilitation objectives for the

aw

p

16.3

16.3.1

Rehabilitation and closure can be

Progressive

Closure

Post closure

As described in Section remain active until closure. However, progressive rehabilitation can occur in places suborrow pits, embankments of the WRD and TSF and disused access tracks.

At closure, decommissioning, demolition and removal of the bulk of the process plant infrastructure, power station and the majority of the accommodation village can landforms (WRD and open pit) can also occur.

The size and scale of demolition and rehabilitation works, the weather (wet and dry seasons) and the TSF, that needs to dry sufficiently before rehabilitation works can beclosure and rehabilitation works often need to be scheduled over a number of years.

This extended closure period also requires maintaining some essential infrastructure at the site post closure, to support successive campaiworks

a

pfacilities; and

a

16.3.2

ClearingVegetation clearing in advance of mine activities needs to be managed to ensure clearing is confined tthe appropriate area and any specific locations to be avoided are identified and protected. Clearing be managed through an internal clearing procedure contained in the site

A key aspect to consider for cleared and stockpiled vegetrehabilitation. The primary role of reinstated vegetation debris is to provide a seed store (if directly reapplied) and also as fauna habitat. Storage for longer than a few days or weeks at most, means that any attached seed pods will usually have dried out and dropped their seed, negating this benefit.



ObjectivesThe key rehabilitation objectives for the

as far as practicable, rehabilitation achieves a stable and functioning landform which is comparable with the surrounding landscape and other environmental values; and

prevent and mitigat

Rehabilitation and

16.3.1 Closure Planning Phases


Progressive

Closure

Post closure

As described in Section remain active until closure. However, progressive rehabilitation can occur in places suborrow pits, embankments of the WRD and TSF and disused access tracks.



This extended closure period also requires maintaining some essential infrastructure at the site post closure, to support successive campai

s. At a minimum, this infrastructure is likely to include:

a portion of the accommodation village that remains connected to the WWTP;

power generation to power the accommodation village, comfacilities; and

a water supply bore that allows a potable water supply to be produced.

16.3.2 Rehabilitation Techniques

Clearing Vegetation clearing in advance of mine activities needs to be managed to ensure clearing is confined tthe appropriate area and any specific locations to be avoided are identified and protected. Clearing

managed through an internal clearing procedure contained in the site

A key aspect to consider for cleared and stockpiled vegetrehabilitation. The primary role of reinstated vegetation debris is to provide a seed store (if directly reapplied) and also as fauna habitat. Storage for longer than a few days or weeks at most, means that

ny attached seed pods will usually have dried out and dropped their seed, negating this benefit.



Objectives The key rehabilitation objectives for the

s far as practicable, rehabilitation achieves a stable and functioning landform which is comparable ith the surrounding landscape and other environmental values; and

and mitigate risks assoc

Rehabilitation and

Closure Planning Phases


During the operational (life of mine) phase.

At or immediately after the mine ceases to operate.

For a number of number of years rather than being undertaken as a single, uninterrupted exercise.

As described in Section 16.1, the Mt Peake mine configuration is such that most of the mine features remain active until closure. However, progressive rehabilitation can occur in places suborrow pits, embankments of the WRD and TSF and disused access tracks.



This extended closure period also requires maintaining some essential infrastructure at the site post closure, to support successive campai

. At a minimum, this infrastructure is likely to include:

portion of the accommodation village that remains connected to the WWTP;

ower generation to power the accommodation village, com

water supply bore that allows a potable water supply to be produced.

Rehabilitation Techniques

Vegetation clearing in advance of mine activities needs to be managed to ensure clearing is confined tthe appropriate area and any specific locations to be avoided are identified and protected. Clearing






The key rehabilitation objectives for the Project are:


risks associated with closure and rehabilitation of the Project.

Rehabilitation and Closure

Closure Planning Phases

Rehabilitation and closure can be broken into the following key mine phases:



For a number of reasons, mine closure works number of years rather than being undertaken as a single, uninterrupted exercise.

, the Mt Peake mine configuration is such that most of the mine features remain active until closure. However, progressive rehabilitation can occur in places suborrow pits, embankments of the WRD and TSF and disused access tracks.



This extended closure period also requires maintaining some essential infrastructure at the site post closure, to support successive campaigns of contractors mobilising to site to conduct a program of





Rehabilitation Techniques





roject are:


iated with closure and rehabilitation of the Project.

losure Planning

broken into the following key mine phases:



reasons, mine closure works number of years rather than being undertaken as a single, uninterrupted exercise.




This extended closure period also requires maintaining some essential infrastructure at the site post gns of contractors mobilising to site to conduct a program of











lanning




reasons, mine closure works often number of years rather than being undertaken as a single, uninterrupted exercise.


At closure, decommissioning, demolition and removal of the bulk of the process plant infrastructure, power station and the majority of the accommodation village can occur. Rehabilitation of completed mine





ower generation to power the accommodation village, communications and water treatment




A key aspect to consider for cleared and stockpiled vegetation is the storage time before its rerehabilitation. The primary role of reinstated vegetation debris is to provide a seed store (if directly reapplied) and also as fauna habitat. Storage for longer than a few days or weeks at most, means that






often need to be scheduled over a number of years rather than being undertaken as a single, uninterrupted exercise.


At closure, decommissioning, demolition and removal of the bulk of the process plant infrastructure, occur. Rehabilitation of completed mine

The size and scale of demolition and rehabilitation works, the weather (wet and dry seasons) and the TSF, that needs to dry sufficiently before rehabilitation works can be undertaken, are all reasons why closure and rehabilitation works often need to be scheduled over a number of years.



munications and water treatment



managed through an internal clearing procedure contained in the site Construction EMP.

ation is the storage time before its rerehabilitation. The primary role of reinstated vegetation debris is to provide a seed store (if directly reapplied) and also as fauna habitat. Storage for longer than a few days or weeks at most, means that


s far as practicable, rehabilitation achieves a stable and functioning landform which is comparable


need to be scheduled over a number of years rather than being undertaken as a single, uninterrupted exercise.

, the Mt Peake mine configuration is such that most of the mine features remain active until closure. However, progressive rehabilitation can occur in places such as completed


The size and scale of demolition and rehabilitation works, the weather (wet and dry seasons) and the undertaken, are all reasons why

closure and rehabilitation works often need to be scheduled over a number of years.





Construction EMP.

ation is the storage time before its rerehabilitation. The primary role of reinstated vegetation debris is to provide a seed store (if directly reapplied) and also as fauna habitat. Storage for longer than a few days or weeks at most, means that


16


need to be scheduled over a number of years rather than being undertaken as a single, uninterrupted exercise.

, the Mt Peake mine configuration is such that most of the mine features ch as completed


The size and scale of demolition and rehabilitation works, the weather (wet and dry seasons) and the undertaken, are all reasons why



Vegetation clearing in advance of mine activities needs to be managed to ensure clearing is confined to the appropriate area and any specific locations to be avoided are identified and protected. Clearing will

Construction EMP.

ation is the storage time before its re-use in rehabilitation. The primary role of reinstated vegetation debris is to provide a seed store (if directly reapplied) and also as fauna habitat. Storage for longer than a few days or weeks at most, means that


16-2


ch as completed

occur. Rehabilitation of completed mine

o will

reapplied) and also as fauna habitat. Storage for longer than a few days or weeks at most, means that

Chapter 16


TopsoilFor the purpose of this document, topsoil is defined as the soil profile that contains the majority of the seed store, organic matter and biological (the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able to remove a layer generally determines the topsoil 100 –

Topsoil storage methods topsoil stockpiles of approximately 2 m high minimise the potential of composting and anaerobic conditions formi

Storage time is another key factor. It is generally recognised the storage time is inversely proportional to topsoil viability (activity).

Materials for In addition to topsoil, which is required for all mine features, some mine features require a supply of specific material. Competent rock is required for the following purposes:

adischarges and to protect sections of the base of elevated landforms and abandonment bunds that are subject to erosion from surface floodwaters. Armour rock used for these purposes is usually in th

athe pit void to prevent vehicular access. To reduce the potential of erosion of these features over time that then allows vehicle entry, these features are required to be construct(rocky) material.

RippingA number or ripping methods and types of bulldozer rippers (tines) are used in mine rehabilitation. All ripping should be done on contour, to maximise resistance to surface water flow.

Break soil compaction

Depencreated from earthmoving equipment, ripping to depths of 1.0 plant roots and water to penetrate the soil profile to depth. lateral wings used to break compaction on floors of bauxite mine pits. A single or multiple tines without wings can also be successfully used to break soil compaction in dry soil conditions.



Topsoil For the purpose of this document, topsoil is defined as the soil profile that contains the majority of the seed store, organic matter and biological (the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able to remove a layer generally determines the topsoil

– 200 mm.

Topsoil storage methods topsoil stockpiles of approximately 2 m high minimise the potential of composting and anaerobic conditions forming at depth.

Storage time is another key factor. It is generally recognised the storage time is inversely proportional to topsoil viability (i.e.activity).

Materials for RehabilitationIn addition to topsoil, which is required for all mine features, some mine features require a supply of specific material. Competent rock is required for the following purposes:

armour rock. Armour rock is required for erosion protection on discharges and to protect sections of the base of elevated landforms and abandonment bunds that are subject to erosion from surface floodwaters. Armour rock used for these purposes is usually in the order of 300

abandonment bundsthe pit void to prevent vehicular access. To reduce the potential of erosion of these features over time that then allows vehicle entry, these features are required to be construct(rocky) material.

Ripping A number or ripping methods and types of bulldozer rippers (tines) are used in mine rehabilitation. All ripping should be done on contour, to maximise resistance to surface water flow.


Depending on the extent of soil compaction created from earthmoving equipment, ripping to depths of 1.0 – 1.5plant roots and water to penetrate the soil profile to depth. Figure 16lateral wings used to break compaction on floors of bauxite mine pits. A single or multiple tines without wings can also be successfully used to break soil compaction in dry soil conditions.



For the purpose of this document, topsoil is defined as the soil profile that contains the majority of the seed store, organic matter and biological (the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able to remove a layer generally determines the topsoil

Topsoil storage methods are atopsoil stockpiles of approximately 2 m high minimise the potential of composting and anaerobic

ng at depth.

Storage time is another key factor. It is generally recognised the storage time is inversely proportional to i.e. the longer the storage time, the greater the loss of seed viability and biological

Rehabilitation In addition to topsoil, which is required for all mine features, some mine features require a supply of specific material. Competent rock is required for the following purposes:

. Armour rock is required for erosion protection on discharges and to protect sections of the base of elevated landforms and abandonment bunds that are subject to erosion from surface floodwaters. Armour rock used for these purposes is usually in

e order of 300 – 500 mm diameter; and

bandonment bunds. An abandonment bund is required to be constructed around the perimeter of the pit void to prevent vehicular access. To reduce the potential of erosion of these features over time that then allows vehicle entry, these features are required to be construct(rocky) material.

A number or ripping methods and types of bulldozer rippers (tines) are used in mine rehabilitation. All ripping should be done on contour, to maximise resistance to surface water


ding on the extent of soil compaction created from earthmoving equipment, ripping to

1.5 m will occurplant roots and water to penetrate the soil profile

16-1 shows a single tine with lateral wings used to break compaction on floors of bauxite mine pits. A single or multiple tines without wings can also be successfully used to break soil compaction in dry soil conditions.



For the purpose of this document, topsoil is defined as the soil profile that contains the majority of the seed store, organic matter and biological (the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able to remove a layer generally determines the topsoil

a key factor in maximising topsoil viability. It is generally recognised that topsoil stockpiles of approximately 2 m high minimise the potential of composting and anaerobic

Storage time is another key factor. It is generally recognised the storage time is inversely proportional to the longer the storage time, the greater the loss of seed viability and biological

In addition to topsoil, which is required for all mine features, some mine features require a supply of specific material. Competent rock is required for the following purposes:


mm diameter; and

. An abandonment bund is required to be constructed around the perimeter of the pit void to prevent vehicular access. To reduce the potential of erosion of these features over time that then allows vehicle entry, these features are required to be construct



will occur. This allows plant roots and water to penetrate the soil profile

shows a single tine with lateral wings used to break compaction on floors of bauxite mine pits. A single or multiple tines without wings can also be successfully used to break soil compaction in dry soil conditions.

For the purpose of this document, topsoil is defined as the soil profile that contains the majority of the seed store, organic matter and biological (bacterial and fungthe depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able to remove a layer generally determines the topsoil depth

key factor in maximising topsoil viability. It is generally recognised that topsoil stockpiles of approximately 2 m high minimise the potential of composting and anaerobic




mm diameter; and




. This allows plant roots and water to penetrate the soil profile

shows a single tine with lateral wings used to break compaction on floors of bauxite mine pits. A single or multiple tines without wings can also be successfully used to break soil

Figure

For the purpose of this document, topsoil is defined as the soil profile that contains the majority of the bacterial and fungal) activity. There is no universal definition of

the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able depth. In most mining operati






of bauxite mine pits. A single or multiple tines without wings can also be successfully used to break soil

Figure 16-1

For the purpose of this document, topsoil is defined as the soil profile that contains the majority of the ) activity. There is no universal definition of

the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able most mining operati




. Armour rock is required for erosion protection on drainage diversion structures, spillway discharges and to protect sections of the base of elevated landforms and abandonment bunds that are subject to erosion from surface floodwaters. Armour rock used for these purposes is usually in



Single lateral winged tine


the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able most mining operations this is accepted at



In addition to topsoil, which is required for all mine features, some mine features require a supply of

drainage diversion structures, spillway discharges and to protect sections of the base of elevated landforms and abandonment bunds that are subject to erosion from surface floodwaters. Armour rock used for these purposes is usually in

. An abandonment bund is required to be constructed around the perimeter of the pit void to prevent vehicular access. To reduce the potential of erosion of these features over time that then allows vehicle entry, these features are required to be constructed of competent


ingle lateral winged tine

16


the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able ons this is accepted at



In addition to topsoil, which is required for all mine features, some mine features require a supply of


. An abandonment bund is required to be constructed around the perimeter of the pit void to prevent vehicular access. To reduce the potential of erosion of these features over

ed of competent


ingle lateral winged tine

16-3

) activity. There is no universal definition of the depth of topsoil layer. In a mining context, the practical depth to which earthmoving equipment is able

ons this is accepted at

Storage time is another key factor. It is generally recognised the storage time is inversely proportional to


. An abandonment bund is required to be constructed around the perimeter of


Chapter 16


Water and seed containment on slopes

At Mountpushed down during rehabilitation using a bulldozer to the final batter angle of situation is different tocompacted. Soil compaction on the embankments of these landforms is not likely to achieve the same compaction as pit floor

Retaining rainfall and applvegetation establishment and reducerip to depths of approximately 0.6 and applied seed on slopes. Furrows from this tine are shown in

Figure

Figure




ount Peake, the pushed down during rehabilitation using a bulldozer to the final batter angle of situation is different tocompacted. Soil compaction on the embankments of these landforms is not likely to achieve the same compaction as pit floor

Retaining rainfall and applvegetation establishment and reduce

to depths of approximately 0.6 and applied seed on slopes. Furrows from this tine are shown in

Figure 16-2 Single vertical winged tine

Figure 16-4 Three tine




Peake, the WRD and ROMpushed down during rehabilitation using a bulldozer to the final batter angle of situation is different to pit floors that have been traversed repeatedly by mine equipment and are highly compacted. Soil compaction on the embankments of these landforms is not likely to achieve the same compaction as pit floors.

Retaining rainfall and applyingvegetation establishment and reduce

to depths of approximately 0.6 and applied seed on slopes. Furrows from this tine are shown in

Single vertical winged tine

Three tine ripper




WRD and ROM pad will bepushed down during rehabilitation using a bulldozer to the final batter angle of

pit floors that have been traversed repeatedly by mine equipment and are highly compacted. Soil compaction on the embankments of these landforms is not likely to achieve the same

ying seed and fertilisevegetation establishment and reduced erosion.

to depths of approximately 0.6 – 0.8m but to produce a wide open furrow capable of holding water and applied seed on slopes. Furrows from this tine are shown in


ripper

pad will be constructed from tipped mine waste which is then pushed down during rehabilitation using a bulldozer to the final batter angle of


seed and fertiliser on these slopes erosion. Figure

0.8m but to produce a wide open furrow capable of holding water and applied seed on slopes. Furrows from this tine are shown in


constructed from tipped mine waste which is then pushed down during rehabilitation using a bulldozer to the final batter angle of


r on these slopes Figure 16-2 shows a tine with vertical wings designed to

0.8m but to produce a wide open furrow capable of holding water and applied seed on slopes. Furrows from this tine are shown in Figure

Figure 16-3

Figure 16-5

constructed from tipped mine waste which is then pushed down during rehabilitation using a bulldozer to the final batter angle of


r on these slopes are key criteria in achieving successful shows a tine with vertical wings designed to

0.8m but to produce a wide open furrow capable of holding water Figure 16-3.

3 Winged tine furrows

5 Rip spacing

constructed from tipped mine waste which is then pushed down during rehabilitation using a bulldozer to the final batter angle of less than 20


key criteria in achieving successful shows a tine with vertical wings designed to

0.8m but to produce a wide open furrow capable of holding water

Winged tine furrows

Rip spacing

16

constructed from tipped mine waste which is then 20o. This



0.8m but to produce a wide open furrow capable of holding water

Winged tine furrows

16-4



Chapter 16


Using a single tine on a ‘trackbetween rip furrows is flattened by the bulldozer trackswhere landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. Multiple tines hook these rocks and the dozer drags them, creating a deep this risk as the rock is usually turned by the tine with minimal earth displacement.

On WRD’s that do not consist of minimum of two winged tines behind each track. This would eliminate the embankment. Use of a third tine improved water holding and spacing using double tines (solid lines) and triple tines (dotted line). The dozer passes arthe previous pass so not to drive over previous rip lines.

Seed and FertiliserWhere seeding is specified, the following criteria apply:

swhich

s

fertiliser may be applied to maximise the success of plant growth. Seed and fertiliser application will be preferably done in oappropriate.

16.3.3

As the site is yet to commence operations, no defined list of trials and studies has yet been determined. There is a clear need to implement some rehabilitation programmes early in the project’s life, in order to establish a monitoring life of mine with a successful track record.

16.3.4

Completion criteria are necessary to provide the basis on which successful rehabilitation and mine closure, and achievements of cldeveloped from the closure objectives, in order to provide distinct and measurable criteria for successful rehabilitation of the Mount Peake operation.

Completion criteria allow for verificatifeatures final design and rehabilitation. Verification methods include monitoring results, management audits, design signselected to allow quantitative assessment of rehabilitation performance.

At the current early stage of the mine’s life, it is unrealistic to establish final completion criteria. Results of progressive rehabilitation and monitoring of other mine feathat the stated criteria can be achieved. Therefore, interim completion criteria have been proposed. Target (final) completion criteria have also been documented. Future versions of the MCP will review these cr

The MCP includes a table that identifies closure objectives, completion criteria and measurement tools for each mine feature. An abbreviated version of this table



Using a single tine on a ‘trackbetween rip furrows is flattened by the bulldozer trackswhere landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. Multiple tines hook these rocks and the dozer drags them, creating a deep

s risk as the rock is usually turned by the tine with minimal earth displacement.

On WRD’s that do not consist of minimum of two winged tines behind each track. This would eliminate the embankment. Use of a third tine improved water holding and spacing using double tines (solid lines) and triple tines (dotted line). The dozer passes arthe previous pass so not to drive over previous rip lines.

Seed and FertiliserWhere seeding is specified, the following criteria apply:

surfaces that have been covered with topsoil and ripped will be seeded with local native species which are compatible with other species in the area;

seeding will be carried out prior to the onset of the main rainfall period; and

ertiliser may be applied to maximise the success of plant growth. Seed and fertiliser application will be preferably done in oappropriate.

16.3.3 Future Trials and Studies

As the site is yet to commence operations, no defined list of trials and studies has yet been determined. There is a clear need to implement some rehabilitation programmes early in the project’s life, in order to establish a monitoring life of mine with a successful track record.

16.3.4 Completion Criteria


Completion criteria allow for verificatifeatures final design and rehabilitation. Verification methods include monitoring results, management audits, design signselected to allow quantitative assessment of rehabilitation performance.

At the current early stage of the mine’s life, it is unrealistic to establish final completion criteria. Results of progressive rehabilitation and monitoring of other mine feathat the stated criteria can be achieved. Therefore, interim completion criteria have been proposed. Target (final) completion criteria have also been documented. Future versions of the MCP will review these criteria against the developing body of closure knowledge and revise the criteria if necessary.




Using a single tine on a ‘trackbetween rip furrows is flattened by the bulldozer trackswhere landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. Multiple tines hook these rocks and the dozer drags them, creating a deep


On WRD’s that do not consist of minimum of two winged tines behind each track. This would eliminate the embankment. Use of a third tine improved water holding and seed retention surface thaspacing using double tines (solid lines) and triple tines (dotted line). The dozer passes arthe previous pass so not to drive over previous rip lines.

Seed and Fertiliser Where seeding is specified, the following criteria apply:

urfaces that have been covered with topsoil and ripped will be seeded with local native species are compatible with other species in the area;

eeding will be carried out prior to the onset of the main rainfall period; and

ertiliser may be applied to maximise the success of plant growth. Seed and fertiliser application will be preferably done in one pass with ripping to reduce soil compaction if hand seeding is not

Future Trials and Studies

As the site is yet to commence operations, no defined list of trials and studies has yet been determined. There is a clear need to implement some rehabilitation programmes early in the project’s life, in order to establish a monitoring – feedback life of mine with a successful track record.

Completion Criteria


Completion criteria allow for verificatifeatures final design and rehabilitation. Verification methods include monitoring results, management audits, design sign-off and comparison against reference documents. selected to allow quantitative assessment of rehabilitation performance.

At the current early stage of the mine’s life, it is unrealistic to establish final completion criteria. Results of progressive rehabilitation and monitoring of other mine feathat the stated criteria can be achieved. Therefore, interim completion criteria have been proposed. Target (final) completion criteria have also been documented. Future versions of the MCP will review

iteria against the developing body of closure knowledge and revise the criteria if necessary.




Using a single tine on a ‘track-to-track’ ripping method has a disadvantage in that the intervening space between rip furrows is flattened by the bulldozer trackswhere landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. Multiple tines hook these rocks and the dozer drags them, creating a deep


On WRD’s that do not consist of large rockyminimum of two winged tines behind each track. This would eliminate the embankment. Use of a third tine (Figure 16

seed retention surface thaspacing using double tines (solid lines) and triple tines (dotted line). The dozer passes arthe previous pass so not to drive over previous rip lines.

Where seeding is specified, the following criteria apply:



ertiliser may be applied to maximise the success of plant growth. Seed and fertiliser application will ne pass with ripping to reduce soil compaction if hand seeding is not

Future Trials and Studies

As the site is yet to commence operations, no defined list of trials and studies has yet been determined. There is a clear need to implement some rehabilitation programmes early in the project’s life, in order to

feedback – improvelife of mine with a successful track record.

Completion Criteria

Completion criteria are necessary to provide the basis on which successful rehabilitation and mine closure, and achievements of closure objectives are determined. Completion criteria have been developed from the closure objectives, in order to provide distinct and measurable criteria for successful rehabilitation of the Mount Peake operation.

Completion criteria allow for verification of environmental outcomes for the features final design and rehabilitation. Verification methods include monitoring results, management

off and comparison against reference documents. selected to allow quantitative assessment of rehabilitation performance.




track’ ripping method has a disadvantage in that the intervening space between rip furrows is flattened by the bulldozer trackswhere landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. Multiple tines hook these rocks and the dozer drags them, creating a deep


large rocky mine waste, minimum of two winged tines behind each track. This would eliminate the

16-4) may be trialled, to determine if the final profile provides an seed retention surface tha

spacing using double tines (solid lines) and triple tines (dotted line). The dozer passes arthe previous pass so not to drive over previous rip lines.






improvement cycle to life of mine with a successful track record.

Completion criteria are necessary to provide the basis on which successful rehabilitation and mine osure objectives are determined. Completion criteria have been

developed from the closure objectives, in order to provide distinct and measurable criteria for successful rehabilitation of the Mount Peake operation.

on of environmental outcomes for the features final design and rehabilitation. Verification methods include monitoring results, management





track’ ripping method has a disadvantage in that the intervening space between rip furrows is flattened by the bulldozer tracks. However, where landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. Multiple tines hook these rocks and the dozer drags them, creating a deep


mine waste, multiple winged tines are recommended, with a minimum of two winged tines behind each track. This would eliminate the

ay be trialled, to determine if the final profile provides an seed retention surface than two tines.

spacing using double tines (solid lines) and triple tines (dotted line). The dozer passes arthe previous pass so not to drive over previous rip lines.






ment cycle to develop rehabilitation prescriptions over the


developed from the closure objectives, in order to provide distinct and measurable criteria for successful

on of environmental outcomes for the features final design and rehabilitation. Verification methods include monitoring results, management


At the current early stage of the mine’s life, it is unrealistic to establish final completion criteria. Results of progressive rehabilitation and monitoring of other mine features is required before that the stated criteria can be achieved. Therefore, interim completion criteria have been proposed. Target (final) completion criteria have also been documented. Future versions of the MCP will review


The MCP includes a table that identifies closure objectives, completion criteria and measurement tools for each mine feature. An abbreviated version of this table is provided

track’ ripping method has a disadvantage in that the intervening space However, this single tine technique is preferred

where landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. Multiple tines hook these rocks and the dozer drags them, creating a deep gully.


multiple winged tines are recommended, with a minimum of two winged tines behind each track. This would eliminate the track print on the landform

ay be trialled, to determine if the final profile provides an two tines. Figure 16-5

spacing using double tines (solid lines) and triple tines (dotted line). The dozer passes ar

urfaces that have been covered with topsoil and ripped will be seeded with local native species




develop rehabilitation prescriptions over the



on of environmental outcomes for the Project area as well as each features final design and rehabilitation. Verification methods include monitoring results, management

off and comparison against reference documents. Measurement tools haselected to allow quantitative assessment of rehabilitation performance.

At the current early stage of the mine’s life, it is unrealistic to establish final completion criteria. Results of tures is required before

that the stated criteria can be achieved. Therefore, interim completion criteria have been proposed. Target (final) completion criteria have also been documented. Future versions of the MCP will review


The MCP includes a table that identifies closure objectives, completion criteria and measurement tools is provided Table 16

track’ ripping method has a disadvantage in that the intervening space this single tine technique is preferred

where landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. gully. The single tine reduces


multiple winged tines are recommended, with a track print on the landform

ay be trialled, to determine if the final profile provides an 5 shows a conceptual rip

spacing using double tines (solid lines) and triple tines (dotted line). The dozer passes are off








roject area as well as each features final design and rehabilitation. Verification methods include monitoring results, management

Measurement tools ha

At the current early stage of the mine’s life, it is unrealistic to establish final completion criteria. Results of tures is required before TNG can be confident



The MCP includes a table that identifies closure objectives, completion criteria and measurement tools 16-1.

16


where landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. The single tine reduces

multiple winged tines are recommended, with a track print on the landform

ay be trialled, to determine if the final profile provides an shows a conceptual rip

e off-set from







roject area as well as each features final design and rehabilitation. Verification methods include monitoring results, management

Measurement tools have been

At the current early stage of the mine’s life, it is unrealistic to establish final completion criteria. Results of can be confident



The MCP includes a table that identifies closure objectives, completion criteria and measurement tools

16-5


where landforms can include large rocks. In these situations, ripping can bring these rocks to the surface. The single tine reduces

multiple winged tines are recommended, with a

ay be trialled, to determine if the final profile provides an shows a conceptual rip

set from

ertiliser may be applied to maximise the success of plant growth. Seed and fertiliser application will




roject area as well as each

At the current early stage of the mine’s life, it is unrealistic to establish final completion criteria. Results of can be confident

The MCP includes a table that identifies closure objectives, completion criteria and measurement tools


Table



Table 16-1 Closure objectives and criteria

Domain Mine feature

All General / site wide

1 Open pit

2 WRD and ROM pad

3 TSF

4 Process plant and power station

5 Rail siding



Closure objectives and criteria

eature Interim c

General / site Hazardous environmental impact.Infrastructure removed.Disturbed areas rehabilitated.

Open pit Abandonment bund effectively restricts access to open pit. Abandonment bund is constructed in accordance with the Safety Bund Walls Mines Guidelines (DoI

WRD and ROM pad

The landform is stable and safe.There areor salt in the vicinity of the landform.

The landform is stable and safe.Erosion of any waste rock cap does not liberate tailings material.Stability assessment defined procedures or standards.Water quality parameters in groundwater monitoring bores do not exceed values representative of analogue sites andThere are no mass vegetation deaths in the vicinity of the landform.

Process plant and power station

Hazardous materials confined to prevent off site environmental impact.Infrastructure removed.Disturbed areas rehabilitated.

Rail siding All infrastructure not subject to a sequential use agreement is removed.Disturbed areas rehabilitated.



Closure objectives and criteria

completion criteria

Hazardous materials confined to prevent off site environmental impact. Infrastructure removed. Disturbed areas rehabilitated.Abandonment bund effectively restricts access to open pit. Abandonment bund is constructed in accordance with the Safety Bund Walls Around Mines Guidelines (DoIR 1997).The landform is stable and safe.There are no mass vegetation deaths caused by AMD or salt in the vicinity of the landform.

The landform is stable and safe.Erosion of any waste rock cap does not liberate tailings material. Stability assessment undertaken in accordance with defined procedures or standards.Water quality parameters in groundwater monitoring bores do not exceed values representative of analogue sites and / or baseline data.There are no mass vegetation deaths in the vicinity of

landform. Hazardous materials confined to prevent off site environmental impact. Infrastructure removed. Disturbed areas rehabilitated.All infrastructure not subject to a sequential use agreement is removed. Disturbed areas rehabilitated.

materials confined to prevent off site

Disturbed areas rehabilitated. Abandonment bund effectively restricts access to

Abandonment bund is constructed in accordance with round Abandoned Open Pit

R 1997). The landform is stable and safe.

no mass vegetation deaths caused by AMD or salt in the vicinity of the landform.

The landform is stable and safe. Erosion of any waste rock cap does not liberate

undertaken in accordance with defined procedures or standards. Water quality parameters in groundwater monitoring bores do not exceed values representative of

or baseline data. There are no mass vegetation deaths in the vicinity of

Hazardous materials confined to prevent off site

Disturbed areas rehabilitated. All infrastructure not subject to a sequential use

Disturbed areas rehabilitated.

Measurement

materials confined to prevent off site Contaminated sites audit. Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Rehabilitation monitoring results.

Abandonment bund effectively restricts access to

Abandonment bund is constructed in accordance with Open Pit

Visual inspections and completed checklist.Decommissioning audit to confirm initial rehabilitation works have been constructed according to design.

no mass vegetation deaths caused by AMD Stability assessment undertaken in accordance with defined procedures.Visual inspections and completed checklist.Decommissioning audit to confirm initial rehabilitation worconstructed according to design. Rehabilitation monitoring results

Erosion of any waste rock cap does not liberate

undertaken in accordance with

Water quality parameters in groundwater monitoring

There are no mass vegetation deaths in the vicinity of

Stability assessment undertaken in accordance with defined procedures or standards. TSF monitoring register to be maintainedVisual inspections and completed checklist.Water quality monitoring results. Water quality records of local surface Rehabilitation monitoring results

Hazardous materials confined to prevent off site Contaminated sites audit. Decommissioningconstructed according to design. Rehabilitation monitoring results.

All infrastructure not subject to a sequential use Decommissioning auditconstructed according to design. Rehabilitation monitoring results.

Measurement tools / performance indicators

Contaminated sites audit. Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Rehabilitation monitoring results.Visual inspections and completed checklist.Decommissioning audit to confirm initial rehabilitation works have been constructed according to design.

Stability assessment undertaken in accordance with defined procedures.Visual inspections and completed checklist.Decommissioning audit to confirm initial rehabilitation worconstructed according to design. Rehabilitation monitoring resultsStability assessment undertaken in accordance with defined procedures or standards. TSF monitoring register to be maintainedVisual inspections and completed checklist.Water quality monitoring results. Water quality records of local surface Rehabilitation monitoring results

Contaminated sites audit. Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Rehabilitation monitoring results.Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Rehabilitation monitoring results.

erformance indicators

Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Complete audit inspection checklist.Rehabilitation monitoring results. Visual inspections and completed checklist. Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Complete audit inspection checklist.

Stability assessment undertaken in accordance with defined procedures.Visual inspections and completed checklist. Decommissioning audit to confirm initial rehabilitation worconstructed according to design. Complete audit inspection checklist.Rehabilitation monitoring results. Stability assessment undertaken in accordance with defined procedures or

TSF monitoring register to be maintained. Visual inspections and completed checklist. Water quality monitoring results. Water quality records of local surface and ground water.Rehabilitation monitoring results

to confirm initial rehabilitation works have been constructed according to design. Complete audit inspection checklist.Rehabilitation monitoring results.

to confirm initial rehabilitation works have been constructed according to design. Complete audit inspection checklist.Rehabilitation monitoring results.

Decommissioning audit to confirm initial rehabilitation works have been audit inspection checklist.

Decommissioning audit to confirm initial rehabilitation works have been Complete audit inspection checklist.

Stability assessment undertaken in accordance with defined procedures.


Stability assessment undertaken in accordance with defined procedures or

and ground water.

to confirm initial rehabilitation works have been Complete audit inspection checklist.


16-6

Decommissioning audit to confirm initial rehabilitation works have been audit inspection checklist.


Stability assessment undertaken in accordance with defined procedures.

ks have been Complete audit inspection checklist.

Stability assessment undertaken in accordance with defined procedures or






Domain Mine feature

6 Access road

7 Bore field

8 Pipelines and power lines

9 Ancillary infrastructure areas



eature Interim c

Access road Roads are reshaped in order to redrainage lines and waters are not impounded.Roads required for monitoring and maintenance are in useable condition.Rehabilitated road areas are stable and non

Bore field All infrastructure removed.Rehabilitated areas are stable and non

Pipelines and power lines

Above ground pipelines, pumping and power infrastructure are removed.Buried pipelines are flushed, emptied, grouted at either end and buried at least 600 mm below the surface.

Ancillary infrastructure

All infrastructure, mobile plant, transportable structures and consumables are removed. Concrete is buried to a depth of at least 1 m below ground level.



completion criteria

Roads are reshaped in order to redrainage lines and waters are not impounded.Roads required for monitoring and maintenance are in useable condition. Rehabilitated road areas are stable and nonAll infrastructure removed. Rehabilitated areas are stable and non

Above ground pipelines, pumping and power tructure are removed.

Buried pipelines are flushed, emptied, grouted at either end and buried at least 600 mm below the surface. All infrastructure, mobile plant, transportable structures and consumables are removed. Concrete is buried to a depth of at least 1 m below ground level.

Roads are reshaped in order to re-instate natural drainage lines and waters are not impounded. Roads required for monitoring and maintenance are in

Rehabilitated road areas are stable and non-eroding.

Rehabilitated areas are stable and non-eroding.

Above ground pipelines, pumping and power tructure are removed.

Buried pipelines are flushed, emptied, grouted at either end and buried at least 600 mm below the

All infrastructure, mobile plant, transportable structures and consumables are removed. Concrete is buried to a depth of at least 1 m below

Measurement

instate natural

Roads required for monitoring and maintenance are in

eroding.

Visual inspections and completed checklist.Decommissioning audit toconstructed according to design. Rehabilitation monitoring results

eroding. Visual inspections and completed checklist.Decommissioning audit to confirm initial rehabilitation works have been constructed according to design.

Buried pipelines are flushed, emptied, grouted at either end and buried at least 600 mm below the

Decommissioning audit to confirm initial rehabilitation works have been constructed according to design.

Concrete is buried to a depth of at least 1 m below

Decommissioning audit to confirm initial rehabilitatconstructed according to design. Complet

Measurement tools / performance indicators

Visual inspections and completed checklist.Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Rehabilitation monitoring results

inspections and completed checklist.Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Decommissioning audit to confirm initial rehabilitation works have been constructed according to design.

Decommissioning audit to confirm initial rehabilitatconstructed according to design. Complet

erformance indicators

Visual inspections and completed checklist. confirm initial rehabilitation works have been

constructed according to design. Complete audit inspection checklist.Rehabilitation monitoring results

inspections and completed checklist. Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Complete audit inspection checklist.Decommissioning audit to confirm initial rehabilitation works have been constructed according to design. Complete audit inspect

Decommissioning audit to confirm initial rehabilitatconstructed according to design. Complete audit inspection c

confirm initial rehabilitation works have been Complete audit inspection checklist.



Decommissioning audit to confirm initial rehabilitation works have been audit inspection checklist

16-7

confirm initial rehabilitation works have been Complete audit inspection checklist.


Decommissioning audit to confirm initial rehabilitation works have been ion checklist.

ion works have been hecklist.

Chapter 16


16.3.5

Should visual inspections or monitoring results indicate the need for maintenance works or remedial action to be undertaken, TNG will mobilise contractors to site to undemaintenance works may include:

vmay be required. Also, weed w

erehabilitation is not progressing towards a selfmay be considered:

o

o

aaccess.

16.3.6

Maintaining an effective data management system is essential to ensure rehabilitation and closure related information is stored and maintained during the life of mine.

TNG will establish and maintain a document management system to store all relevant rehabilitation and closure information for the Mount Peake

16.3.7

Ultimately, the goal of all mine closure and rehabilitation works is to leave a final landfstakeholder objectives and achieves the completion criteria. The mine operator can then apply for relinquishment of the mining tenement and return of environmental securities.

16.4

16.4.1

The oand / or reshallow

aAround geotechnical studies conducted to

sthe



16.3.5 Post Closure Maintenance


vegetation - if rehabilitation is failing, additional application of fertiliser, additional seeding or planting may be required. Also, weed w

erosion - if significant rehabilitation is not progressing towards a selfmay be considered:

o construct, improve, or repair drainage control measures to reduce water slopes of the landform; and

o areas of deep erosion and

access - remedial works will be required if access prevention measures fail to restrict unauthorised access.

16.3.6 Data Management



16.3.7 Relinquishment


Rehabilitation Design

16.4.1 Open Pit

The open pit will be left safeand / or re-profiled mine landforms. shallow pit lake. Rehabilitation actions include:

abandonment bunds will be constructed around the pit in accordance with the Safety Bund Walls Around Abandoned geotechnical studies conducted to

surfaces outside the abandonment bund the rehabilitation



Post Closure Maintenance


f rehabilitation is failing, additional application of fertiliser, additional seeding or planting may be required. Also, weed w

f significant embankment erosion on the TSF, WRD or ROM pad is identified or rehabilitation is not progressing towards a selfmay be considered:

construct, improve, or repair drainage control measures to reduce water slopes of the landform; and

areas of deep erosion and

emedial works will be required if access prevention measures fail to restrict unauthorised

a Management



Relinquishment



Open Pit

pen pit will be left safe, restricting unauthorised public access by utilising abandonment bunding profiled mine landforms.

pit lake. Rehabilitation actions include:

bandonment bunds will be constructed around the pit in accordance with the Safety Bund Walls Abandoned Open Pit Mines Guidelines (DoIR 1997)

geotechnical studies conducted to

outside the abandonment bund rehabilitation strategies de



Post Closure Maintenance


f rehabilitation is failing, additional application of fertiliser, additional seeding or planting may be required. Also, weed will be implemented if required;

embankment erosion on the TSF, WRD or ROM pad is identified or rehabilitation is not progressing towards a self

construct, improve, or repair drainage control measures to reduce water slopes of the landform; and

areas of deep erosion and / or instability may need to be remediated with appropriate material.



TNG will establish and maintain a document management system to store all relevant rehabilitation and closure information for the Mount Peake P



, restricting unauthorised public access by utilising abandonment bunding profiled mine landforms. Groundwater recovery post closure will result in the formation of a


bandonment bunds will be constructed around the pit in accordance with the Safety Bund Walls Open Pit Mines Guidelines (DoIR 1997)

geotechnical studies conducted to determine

outside the abandonment bund strategies detailed in Section

Should visual inspections or monitoring results indicate the need for maintenance works or remedial action to be undertaken, TNG will mobilise contractors to site to unde

f rehabilitation is failing, additional application of fertiliser, additional seeding or planting ill be implemented if required;

embankment erosion on the TSF, WRD or ROM pad is identified or rehabilitation is not progressing towards a self-sustaining community, the following remedial actions

construct, improve, or repair drainage control measures to reduce water

or instability may need to be remediated with appropriate material.



TNG will establish and maintain a document management system to store all relevant rehabilitation and Project.


, restricting unauthorised public access by utilising abandonment bunding roundwater recovery post closure will result in the formation of a


bandonment bunds will be constructed around the pit in accordance with the Safety Bund Walls Open Pit Mines Guidelines (DoIR 1997)

determine the extent of bunding to be constructed; and

outside the abandonment bund will be covered with topsoil, ripped and seeded according to tailed in Section 16.3.2

Should visual inspections or monitoring results indicate the need for maintenance works or remedial action to be undertaken, TNG will mobilise contractors to site to unde

f rehabilitation is failing, additional application of fertiliser, additional seeding or planting ill be implemented if required;

embankment erosion on the TSF, WRD or ROM pad is identified or sustaining community, the following remedial actions





TNG will establish and maintain a document management system to store all relevant rehabilitation and



bandonment bunds will be constructed around the pit in accordance with the Safety Bund Walls Open Pit Mines Guidelines (DoIR 1997) (Figure

the extent of bunding to be constructed; and

will be covered with topsoil, ripped and seeded according to 16.3.2.

Should visual inspections or monitoring results indicate the need for maintenance works or remedial action to be undertaken, TNG will mobilise contractors to site to undertake these works. Such

f rehabilitation is failing, additional application of fertiliser, additional seeding or planting









bandonment bunds will be constructed around the pit in accordance with the Safety Bund Walls Figure 16-6),


will be covered with topsoil, ripped and seeded according to

Should visual inspections or monitoring results indicate the need for maintenance works or remedial rtake these works. Such



construct, improve, or repair drainage control measures to reduce water movement down outer



Maintaining an effective data management system is essential to ensure rehabilitation and closure


Ultimately, the goal of all mine closure and rehabilitation works is to leave a final landform that meets all stakeholder objectives and achieves the completion criteria. The mine operator can then apply for


bandonment bunds will be constructed around the pit in accordance with the Safety Bund Walls , or in accordance with



16

Should visual inspections or monitoring results indicate the need for maintenance works or remedial rtake these works. Such



movement down outer



Maintaining an effective data management system is essential to ensure rehabilitation and closure


orm that meets all stakeholder objectives and achieves the completion criteria. The mine operator can then apply for


bandonment bunds will be constructed around the pit in accordance with the Safety Bund Walls or in accordance with



16-8


sustaining community, the following remedial actions

movement down outer




orm that meets all


Chapter 16


Figure

16.4.2

Given the nature of embankment. Capping of the TSF surface will occur after closure when it has dried sufficiently to allow machine access.

Figure

A ‘store and release’ cover design is considered a valid rehabilitation option for the store and release cover design uses select materials as a monolithic storage layer able to absorb precipitation into the soilevapotranspiration, to manage the water with minimal or no runoff.



Figure 16-6 Conceptual pit abandonment bund design

16.4.2 TSF

Given the nature of embankment. Capping of the TSF surface will occur after closure when it has dried sufficiently to allow machine access.

Figure 16-7 TSF design

A ‘store and release’ cover design is considered a valid rehabilitation option for the store and release cover design uses select materials as a monolithic storage layer able to absorb precipitation into the soilevapotranspiration, to manage the water with minimal or no runoff.



Conceptual pit abandonment bund design

Given the nature of the operating TSF, progressive rehabilitation will be limited to the perimeter embankment. Capping of the TSF surface will occur after closure when it has dried sufficiently to allow machine access. Figure 16-7

TSF design

A ‘store and release’ cover design is considered a valid rehabilitation option for the store and release cover design uses select materials as a monolithic storage layer able to absorb precipitation into the soil / rock mass rather than pondievapotranspiration, to manage the water with minimal or no runoff.




operating TSF, progressive rehabilitation will be limited to the perimeter embankment. Capping of the TSF surface will occur after closure when it has dried sufficiently to allow

shows the TSF design.

A ‘store and release’ cover design is considered a valid rehabilitation option for the store and release cover design uses select materials as a monolithic storage layer able to absorb

rock mass rather than pondievapotranspiration, to manage the water with minimal or no runoff.



shows the TSF design.


rock mass rather than pondievapotranspiration, to manage the water with minimal or no runoff.




rock mass rather than ponding on top, then either allowing infiltration or evapotranspiration, to manage the water with minimal or no runoff.



ng on top, then either allowing infiltration or evapotranspiration, to manage the water with minimal or no runoff. The intention


A ‘store and release’ cover design is considered a valid rehabilitation option for the TSF (Figure store and release cover design uses select materials as a monolithic storage layer able to absorb

ng on top, then either allowing infiltration or he intention will be to limit infiltration.

16


Figure 16-8). A store and release cover design uses select materials as a monolithic storage layer able to absorb

ng on top, then either allowing infiltration or to limit infiltration.

16-9

embankment. Capping of the TSF surface will occur after closure when it has dried sufficiently to allow

. A

to limit infiltration.

Chapter 16


Figure Source: Zornberg

The following general rehabilitation tasks will be applied to

acommissioned prior to rehabilitation works commencing;

a

the (Figure

aconstruct a waste

the TSF capped surface will be covered with topsoil, ripped and seeded according to the actionsdetailed in Section

16.4.3

The following general actions will be applied to close and rehabilitate the WRD:

a

oalternative design approved by a suitably

wdirected to a sump

sdetai



Figure 16-8 Conceptual TSF closure designSource: Zornberg et al.


a review of the TSF by a suitably qualified geotechnical or engineering specialist will be commissioned prior to rehabilitation works commencing;

all process pipe work and general refuse will be removed;

he closed TSF will Figure 16-8);

a materials balance assessment will be undertaken to identify the inert waste rock to be used to construct a waste

he TSF capped surface will be covered with topsoil, ripped and seeded according to the actionsdetailed in Section

16.4.3 WRD


all refuse and remaining infrastructure will be removed;

outer slopes of the facility will be battered alternative design approved by a suitably

water runoff from the odirected to a sump

surfaces will be covered with topsoil, ripped and seeded according to the detailed in Section



Conceptual TSF closure designet al. (2010)


review of the TSF by a suitably qualified geotechnical or engineering specialist will be commissioned prior to rehabilitation works commencing;

ocess pipe work and general refuse will be removed;

TSF will have an);

materials balance assessment will be undertaken to identify the inert waste rock to be used to construct a waste rock cap (Zornberg

he TSF capped surface will be covered with topsoil, ripped and seeded according to the actionsdetailed in Section 16.3.2


ll refuse and remaining infrastructure will be removed;

uter slopes of the facility will be battered alternative design approved by a suitably

ater runoff from the outer slopes of directed to a sump(s) prior to release into natural drainage systems;

urfaces will be covered with topsoil, ripped and seeded according to the led in Section 16.3.2



Conceptual TSF closure design




have an inert waste rock cap designed as a ‘store and release’ cover system

materials balance assessment will be undertaken to identify the inert waste rock to be used to rock cap (Zornberg

he TSF capped surface will be covered with topsoil, ripped and seeded according to the actions16.3.2.



uter slopes of the facility will be battered alternative design approved by a suitably

uter slopes of the prior to release into natural drainage systems;

urfaces will be covered with topsoil, ripped and seeded according to the 16.3.2.

Conceptual TSF closure design




inert waste rock cap designed as a ‘store and release’ cover system

materials balance assessment will be undertaken to identify the inert waste rock to be used to rock cap (Zornberg et al. 2010);

he TSF capped surface will be covered with topsoil, ripped and seeded according to the actions



uter slopes of the facility will be battered to the conceptual design shown in alternative design approved by a suitably qualified geotechnical

the landform will be contained by a toe drain / bund wall and prior to release into natural drainage systems;

urfaces will be covered with topsoil, ripped and seeded according to the

The following general rehabilitation tasks will be applied to the TSF:




materials balance assessment will be undertaken to identify the inert waste rock to be used to 2010); and




to the conceptual design shown in qualified geotechnical

landform will be contained by a toe drain / bund wall and prior to release into natural drainage systems;

urfaces will be covered with topsoil, ripped and seeded according to the

TSF:

review of the TSF by a suitably qualified geotechnical or engineering specialist will be


materials balance assessment will be undertaken to identify the inert waste rock to be used to



to the conceptual design shown in qualified geotechnical engineer;

landform will be contained by a toe drain / bund wall and prior to release into natural drainage systems; and

urfaces will be covered with topsoil, ripped and seeded according to the rehabilitation






to the conceptual design shown in Figure 16

landform will be contained by a toe drain / bund wall and

rehabilitation

16





16-9, or an

landform will be contained by a toe drain / bund wall and

rehabilitation strategies

16-10

Chapter 16


Figure

16.4.4

General actions for rehabilitation of infrastructure areas are as follows:

ademolition works;

sdemolition plan;

s

cA

s

b

n

aretained;

a

16.4.5

The following actions wi

s

w

wdrainage paths;

s16.3.2



Figure 16-9 Conceptual WRD design

16.4.4 Infrastructure


all structures will be decontaminated (if necessary) and washed down prior to the commencement of demolition works;

structural engineers will determine a safe and efficient dismandemolition plan;

structures will be pulled to the ground and dismantled;

concrete slabs and footings will be broken down to a depth of 1 m below the finished ground surfaceAlternatively concrete could be covered to provide

services will be removed or buried at a depth at least 1 m below the final ground surface;

buried pipes left

non-recyclable and inert waste will be disposed of in

access roads required to be left for post closure monitoring purposes need to be defined and retained; and

all areas will be ripped

16.4.5 Site Roads

The following actions wi

sumps, bunding and bitumen will be removed (where applicable);

windrows respread over the road surface and road crown reshaped (where applicable);

where haul roads disrupt surface drainage, excavatidrainage paths;

surfaces will be covered with topsoil, ripped and seeded according to the action detailed in Section 16.3.2.



Conceptual WRD design

Infrastructure


ll structures will be decontaminated (if necessary) and washed down prior to the commencement of demolition works;

tructural engineers will determine a safe and efficient dismandemolition plan;

tructures will be pulled to the ground and dismantled;

oncrete slabs and footings will be broken down to a depth of 1 m below the finished ground surfacelternatively concrete could be covered to provide

ervices will be removed or buried at a depth at least 1 m below the final ground surface;

uried pipes left in situ will be flushed and sealed at each end;

recyclable and inert waste will be disposed of in

ccess roads required to be left for post closure monitoring purposes need to be defined and and

ll areas will be ripped to break compaction

Roads

The following actions will be taken to rehabilitate roads and hardstand areas:

umps, bunding and bitumen will be removed (where applicable);

indrows respread over the road surface and road crown reshaped (where applicable);

here haul roads disrupt surface drainage, excavatidrainage paths; and

urfaces will be covered with topsoil, ripped and seeded according to the action detailed in Section





ll structures will be decontaminated (if necessary) and washed down prior to the commencement of

tructural engineers will determine a safe and efficient disman




will be flushed and sealed at each end;


ccess roads required to be left for post closure monitoring purposes need to be defined and

to break compaction

ll be taken to rehabilitate roads and hardstand areas:



here haul roads disrupt surface drainage, excavati












to break compaction prior to overburden and




here haul roads disrupt surface drainage, excavati






oncrete slabs and footings will be broken down to a depth of 1 m below the finished ground surfacelternatively concrete could be covered to provide the necessary cover depth;



recyclable and inert waste will be disposed of in an onsite lan


prior to overburden and




here haul roads disrupt surface drainage, excavation will occur at low points to re




tructural engineers will determine a safe and efficient dismantling procedure and prepare a

oncrete slabs and footings will be broken down to a depth of 1 m below the finished ground surfacethe necessary cover depth;



onsite landfill or similar;


prior to overburden and / or topsoil application.




on will occur at low points to re



tling procedure and prepare a

oncrete slabs and footings will be broken down to a depth of 1 m below the finished ground surfacethe necessary cover depth;


dfill or similar;


or topsoil application.


on will occur at low points to re-establish natural


16


tling procedure and prepare a

oncrete slabs and footings will be broken down to a depth of 1 m below the finished ground surface



or topsoil application.


establish natural


16-11


oncrete slabs and footings will be broken down to a depth of 1 m below the finished ground surface.

establish natural


Chapter 16


16.5 Stakeholder engagement is a key component of mine closure planning. Mines developed in remote regions often require construction of a range of infand should be retained after mine closure. Retention of any infrastructure must be on the basis of a formal sequential use agreement, where the details of retained infrastructure are described and matof tenure,

At this point in the infrastructure is listed as items most likely to be retained by

the rail siding may be required to remain as a passing bay or parking lo

w

a



Infrastructure to be Retained after ClosureStakeholder engagement is a key component of mine closure planning. Mines developed in remote regions often require construction of a range of infand should be retained after mine closure. Retention of any infrastructure must be on the basis of a formal sequential use agreement, where the details of retained infrastructure are described and mat

tenure, ongoing maintenance liability and legal liability are clearly

At this point in the infrastructure is listed as items most likely to be retained by

he rail siding may be required to remain as a passing bay or parking lo

water bores, storage dams and water tanks m

access roads may be retained for pastoral use, fire brea




ongoing maintenance liability and legal liability are clearly

At this point in the Project’s development, no sequential use agreements are in place. The following infrastructure is listed as items most likely to be retained by


ater bores, storage dams and water tanks m

ccess roads may be retained for pastoral use, fire brea





roject’s development, no sequential use agreements are in place. The following infrastructure is listed as items most likely to be retained by


ater bores, storage dams and water tanks m


Infrastructure to be Retained after ClosureStakeholder engagement is a key component of mine closure planning. Mines developed in remote regions often require construction of a range of infrastructure that other stakeholders consider have value and should be retained after mine closure. Retention of any infrastructure must be on the basis of a formal sequential use agreement, where the details of retained infrastructure are described and mat


roject’s development, no sequential use agreements are in place. The following infrastructure is listed as items most likely to be retained by


ater bores, storage dams and water tanks may be retained for pastoral use; and


Infrastructure to be Retained after Closure Stakeholder engagement is a key component of mine closure planning. Mines developed in remote

rastructure that other stakeholders consider have value and should be retained after mine closure. Retention of any infrastructure must be on the basis of a formal sequential use agreement, where the details of retained infrastructure are described and mat


roject’s development, no sequential use agreements are in place. The following infrastructure is listed as items most likely to be retained by other parties:


ay be retained for pastoral use; and

ccess roads may be retained for pastoral use, fire breaks and general access.

Stakeholder engagement is a key component of mine closure planning. Mines developed in remote rastructure that other stakeholders consider have value

and should be retained after mine closure. Retention of any infrastructure must be on the basis of a formal sequential use agreement, where the details of retained infrastructure are described and mat

ongoing maintenance liability and legal liability are clearly established.

roject’s development, no sequential use agreements are in place. The following other parties:

he rail siding may be required to remain as a passing bay or parking location for general rail traffic;


ks and general access.


and should be retained after mine closure. Retention of any infrastructure must be on the basis of a formal sequential use agreement, where the details of retained infrastructure are described and mat

established.

roject’s development, no sequential use agreements are in place. The following

cation for general rail traffic;


ks and general access.

16


and should be retained after mine closure. Retention of any infrastructure must be on the basis of a formal sequential use agreement, where the details of retained infrastructure are described and matters

roject’s development, no sequential use agreements are in place. The following


16-12

rastructure that other stakeholders consider have value

ters


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