Conference shares international insights to manage the rehabilitation of mined lands

Leading international professionals, stakeholders and companies within the mine rehabilitation sector will share and learn industry insights at a conference tomorrow, hosted by the University of Newcastle’s environmental outreach arm, the Tom Farrell Institute for the Environment (TFI).
Now in its 8th year, the Best Practice Ecological Rehabilitation of Mined Lands Conference will attract more than 260 delegates and feature presentations from international speakers including soils and restoration ecology expert Professor Eduardo Arellano from Chile, forestry expert Professor Yudi Firmanul Arifin from Indonesia, and geomorphic mine rehabilitation expert Professor José Martín Duque from Spain.

The conference, on Thursday 12 April, provides a valuable opportunity for industry practitioners, government regulators, service professionals and academia from across the world to network and promote the use of best-practice approaches in the management of rehabilitation of mined lands.  
For more information and the conference program, go to www.tomfarrellinstitute.org/mlrc2018.

Media are invited for a photo/interview opportunity at the conference: 10.30am – 11am, Thursday 12 April in the Starlight Auditorium at Wests New Lambton.
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Director of the Tom Farrell Institute for the Environment (TFI), Professor Tim Roberts, is available for interview on 0418 205 664.  To organise an interview with an international speaker, please phone Belinda McNab on 0407 655 594.
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Principles of Soilscape and Landscape Evolution by Garry Willgoose to be launched at the 2018 Mine Rehab Conference

Computational models are invaluable in understanding the complex effects of physical processes and environmental factors which interact to influence landform evolution of geologic time scales. This book provides a holistic guide to the construction of numerical models to explain the co-evolution of landforms, soil, vegetation and tectonics, and describes how the geomorphology observable today has been formed. It explains the science of the physical processes and the mechanics of how to solve them, providing a useful resource for graduates studying geomorphology and sedimentary and erosion processes. It also emphasises the methods for assessing the relative importance of different factors at field sites, enabling researchers to select the appropriate processes to model. Integrating a discussion of the fundamental processes with mathematical formulations, it guides the reader in understanding which processes are important and why; and creates a framework through which to study the interaction of soils, vegetation and landforms over time.

'This book was worth the wait! What started as a description of a pioneer modelling effort thirty years ago ended up as a comprehensive treatise on soil and landscape evolution enriched by the experience of Dr Willgoose. Hydrologists and geomorphologists interested in a quantitative understanding of what goes on the critical surface zone of the geosphere must read this book.'

Rafael L. Bras - Georgia Institute of Technology

'If it moves, model it! There is no better synthesis of all the various elements in landscapes and soil than this lifetime compilation in which Willgoose examines the many mechanisms operating in the landscape, at scales from continental tectonics down to the soil profile, demonstrating how he and others have built them into functional, mutually consistent and inter-connecting models. Its greatest strengths lie in the incorporation of soil processes - physical breakdown, mixing and weathering; and in how principles and models have been applied to the management of degrading spoil heaps.'

Mike Kirkby - University of Leeds

'An outstanding synthesis that thoroughly addresses both the theoretical basis and practical application of landscape evolution modelling - a benchmark of its kind.'
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Stuart Lane - Université de Lausanne

To order online goto: http://bit.ly/2GLjItz

Book Launch - Spoil to Soil: Mine Site Rehabilitation and Revegetation - to be launched at the 2018 Mine Rehab Conference on Thursday 12th April
- Alec Roberts

Spoil to Soil looks at both the fundamental and practical aspects of remediation and revegetation of mine sites and provides a narrative of how inert soil can be converted to living soil.
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This book is a collaboration from researchers across the world, including: South Korea, United States, Australia, New Zealand, Malaysia and Canada.

The three editors, Dr Ok from Korea University, Prof Kirkham from Kansas State University and our own Prof Nanthi Bolan from University of Newcastle, have provided a framework for their research colleagues and students to guide their research on Mine Rehab.

These researchers include 15 from the Global Centre for Environmental Remediation at the University of Newcastle, many of who are in the room today.
 
The book examines the fundamental properties of mine site spoil through:

• Hydrochemical and geochemical dynamics of mining wastes;
• Bio-waste amendments to improve the physical, chemical, and biological properties of mine impacted soils [Nanthi and Hasintha];
• Biochar amendments; and
• Predictive techniques for acid mine drainage.

 
Spoil to Soil illustrates various approaches to mine site rehab practices.  Importantly the biological characteristics of mine tailings and the ecological inputs required to rehabilitate soil-like biological properties and conditions which allow soil formation (pedogenesis) and reduction in the mobility of heavy metals in the soil using plant communities (or phytostabilization) are addressed in significant detail.

 
New research is presented looking at using nanotechnology for mine site remediation for organic contaminants (such as PCB’s) and inorganic contaminants such as heavy metals.
 
The book also looks at the post mine site land-use practices of beef cattle production on rehab mine lands including the pasture and grazing trials here in the Hunter Valley.

Case studies are presented from the Appalachian coalfields including reforestation approaches following surface coalmining [read controversial mountain top removal]; and recreating headwater stream systems using Natural Channel Design techniques.

The book also covers interesting topics on key issues on mine closure planning for pit lakes and the potential for soil carbon sequestration for lands disturbed by mining.
  
Spoil to Soil is not only relevant to mined land rehabilitation in Australia but with its international case studies much can be learnt from the descriptions of successful mine rehabilitation in:

• Malaysia – tin mines;
• New Zealand; and
• Canada – including an innovative technique in freezing the ground to prevent the release of soluble arsenic.

The publishers have a special deal for conference delegates and are providing 20% off when you order online.  A flyer detailing this is in your delegates bag.

It gives me much pleasure to launch the book Spoil to Soil.

Please join with me in congratulating Nanthi and his colleagues.

To order online goto: bit.ly/SpoiltoSoil

José F. Martin Duque is a visiting academic at the Tom Farrell Institute from Complutense University of Madrid, Spain.

The standard of rehabilitation has improved significantly with increasing environmental knowledge and requirements over time with non-viable mine sites now viable due to these changes.  For example, Kaolin deposits in Spain that adjoin the Alto Tajo National Park are able to be accessed.  This is possible using geomorphic rehabilitation. Existing abandoned Kaolin mines have significant environmental issues in the area with 5-6m gullies formed and over 350 t/ha/yr of erosion resulting in decreased trout populations in the national park due to kaolin sediment.  Gabion check dams used to contain the sediment load have proved ineffective. For example in 2009-2010 800,000€ was spent on these dams which was supposed to last 10 years - they lasted only 3 months.

Active Kaolin mines are using sediment ponds.  Terraces which are not stable are to be replaced by Geomorphic Rehabilitation as gullies form following rain events which are expensive to repair.

Concave slopes reduce erosion - landforms in nature are convex to concave. A stable drainage network is also needed that should integrate with existing watercourses.

The recommended solution was Geomorphic catchment rehabilitation using GeoFluv - Natural Regrade to replicate stable landforms in natural catchments. 

Landscape modelling tools such as SIBERIA provide complementary capabilities to geomorphic design methods such as GeoFluv - Natural Regrade where iterative use provides optimal stable designs for mine rehabilitation.

Geomorphic rehabilitation provides the path for restoring hydrologic and ecologic function of the land, resulting in increased land use and a visually appealing landscape.

Geomorphic rehabilitation is relatively new practice which works best with progressive rehabilitation of the mine site but is popular with both the public and regulators.  Watch this space!

For more information (in Spanish) and papers (in Spanish/English) supporting this practice:  
www.restauraciongeomorfologica.es
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Report: Mangoola Open Cut Coal mine and rehabilitation site
by
Jose F. Martin Duque, Alec Roberts, Korbinian Kraus, Nigel Stace
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Mangoola Open Cut Coal mine is located approximately 20 km western direction from Muswellbrook. The exploration of Mangoola began in the early 2000’s as they found coal in a very shallow depth.  Mangoola mine is owned and operated by Glencore.
 
Mangoola mine produces thermal coal principally for export, with 25% being supplied to AGL for local use at the Hunter Valley Coal-powered thermal power stations Liddell and Bayswater. The mine employs 294 people.  The mine has really high visibility, as they promote trips to the mine by schools, and the public. They receive more than 700 visitors in a year.
 
In Mangoola the coal is very close to the surface, which makes truck and shovel mining the adequate mining procedure (not dragline seen at other open cut mines in the Hunter). On a total area of 10,200 ha, with the mine currently 2299 ha in size, the vast amount of 13.5 MT per annum is harvested. But what to do with the land after being mined?
 
The magic words are good mine rehabilitation. Good progressive rehabilitation is necessary for a mine in order to stay accepted in the community.
 
In Mangoola 380 ha have already been rehabilitated and it is planned to treat 100 ha per year over the next 5 years. The mine also has an additional 3000 ha of offsets and approximately 4,800 ha setup for grazing.
The mine owners Glencore are required to lodge a security bond with the NSW Government to cover the full cost of rehabilitation. The size of the rehabilitation security bond is set each year, and varies from year to year depending on the amount of land requiring rehabilitation.  Currently $54 million is held as a rehabilitation deposit.
 
Progressive rehabilitation allows the mine owner to reduce the amount of security bond held by the government.  Progressive rehabilitation involves the staged restoration of disturbed areas during the mine operation, instead of large-scale works at the end of the mines life.  Progressive rehabilitation is undertaken at Mangoola, with the driver for this being the size of the security bonds.  The mine has an annual rehabilitation and land management plan which includes the management of the buffer lands.   The Environment manager meets weekly with operations staff to ensure mine operations and rehab are in synch.
 
With the help of Software such as GIS and GEOFLUV – Natural Regrade geomorphologists can create a landscape that comes very close to natural territory. They can plan hills, valleys and everything else natural landscape has.  One of the mines goals is to produce a sustainable landform and drainage design with the mining planning working towards a final geomorphic landform design.  The mine also uses the best practice Landscape Evolution Model SIBERIA to test landform stability.
 
The mine says that it is economically worthwhile to do GeoFluv, because even if it would be more expensive, it has high community acceptance. They also specifically recognize the advantages of geomorphic-based progressive rehabilitation: reduction of dust, bond release, liability, commitment, and cost saving by the absence of drop structures (down drains) in the final design.
With the shallow depth of operation, the cost of extracting the coal is less than other sites, however the rate of progressive rehabilitation in greater (as more ground is covered to extract the same amount of coal). 
 
External contractors are used for the rehab preparation which is:

1. Bulk Shaping
2. Top Soil placement
3. Gypsum application

 
Bulk shaping is done using a GPS guided dozer (D6). Top soil stockpiles are kept onsite for use within a couple of weeks to maintain topsoil viability.  Where possible, top soil is placed directly in its target location.
 
Following the application of gypsum, the land is deep ripped and approximately 100m of mulch is applied and then a sterile cover crop of oats and Japanese millet is hand sown.  Hand sowing is an effective method compared to other techniques as no heavy vehicles are required onsite and can be done at short notice.  The mine land was originally 700 ha of grassland with the remaining land light woodland.  The plan is to put back the ecological communities that were once here.
 
A seed collection program in the buffer lands and offsets provides a good source of viable indigenous plant and tree species seed which are then hand sown into the rehab.
Salvaged timber with hollows are placed upright (stag trees) presumably for birds of prey. Big rocks are placed on the land and together with the stage trees deliver some shadow and shelter for animals and vegetation.  All this creates an artificial landscape that improves the quality of the land and decreases the negative effects of the coal mining.
 
Nesting boxes are placed throughout the rehab and offsets to encourage wildlife.  Tiger orchids have been transplanted to more established trees and stag trees. 
 
The GeoFluv landforms have a main role in the design of the valleys. It is what we could term an adapted version of GeoFluv, in which large mines try to simplify procedures of rehabilitation, to include them in mine production but keeping the principles of the method.  The mining plan works towards the final landform (which is the most difficult part to achieve).
 
Rehab is a rather slow an ongoing business, it takes a while until the first success can be seen. However, Mangoola can act as a kind of role model for other mines. They started five years ago with moving and replanting parts of the mine.  In Mangoola birds and other animals start to repopulate the land again, which is a sign of successful rehab.
 
Compared to other mines in the Hunter Valley, Mangoola is doing a very good job. In general, the mine is a VERY good example of progressive rehabilitation and also the consideration of landforms, soils, revegetation, and fauna.
 
For more information see:
Kelder, I, Waygood CG & Willis, T 2016, 'Integrating the use of natural analogues and erosion modelling in landform design for closure', in AB Fourie & M Tibbett (eds), Proceedings of the 11th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 99-106.

Tim Roberts, Elspeth Pottie & Steven Lucas

Keynote Address: “Dealing with Derelict Mines: Novel risk-based management approaches to dealing with problems, issues and policy challenges” International Conference 6-8 December 2016. Singleton, NSW.

Abstract:
Since time immemorial the mining of the earth’s riches has been a universal and necessary function of societies across the world.  The situation in Australia has been no different, from the agates of the stone implements of the indigenous peoples through to the sandstone quarries of the First Fleeters, the gold rushes, the miners in general and most recently the huge excavations of the coal miners.  The riches have been there for the taking for individual wealth creation and through the taxing with licences and royalties national wealth creation.  Also since time immemorial abandonment of the mine when the resource has been exhausted has been the common practice, with the cleanup, the restoration, the reinstatement of the landscape left to the community that has lived in that space premining.
With some 50,000 abandoned mines across Australia the impact on these communities is manifold, from an innocuous hole in the ground that can be used for recreation, to disturbed land prone to sinkholes and subsidence, through to the highly dangerous toxic and acidic leachate emitters. Although governments have been quick to set in place the taxing implements related to active mining, it is only in recent decades that rehabilitation requirements have been enshrined in legislation. 
A derelict mine is one that no longer has an owner, but indeed it is in fact “owned” by the community of that area.  That community was associated with that landscape before it was disturbed and lives with the disturbance presently and into the future.  Similarly the government has moral ownership of the derelict mine as it had been party to approval, and implantation of the mine through licencing, taxing, and royalty collection.
The socio-cultural legacies of abandoned mines are intimately intertwined with the environmental legacies which are often all too visible.  Communities endure and the derelict mines whilst inducing solastalgia in the individual generations that lived through the active mine life; offer in some cases opportunities for new use of the landscape and in other cases an enduring environmental hazard.