U n i v

U n i v
University of Pretoria etd – Tsivhandekano, N A (2005)
Documenting reclamation and closure of Ermelo coal mines (Mpumalanga
Province): Implications for developing a national strategy for mine reclamation
in South Africa.
by
Ndinannyi Aubrey Tshivhandekano
9929855
Submitted in partial fulfilment of the requirements for course:
Research Report: Environment and Society
as part of the degree
Master of Arts (Environment and Society),
Department of Geography, Geoinformatics & Meteorology,
Faculty of Humanities,
University of Pretoria,
Pretoria,
20 December 2004
University of Pretoria etd – Tsivhandekano, N A (2005)
ABSTRACT
Documenting reclamation and closure of Ermelo coal mines: Implications for
developing a national strategy for mine reclamation in South Africa.
AUBREY NDINANNYI TSHIVHANDEKANO
Supervisor:
Prof. K.I. Meiklejohn
Department of Geography, Geoinformatics & Meteorology
Abstract
The reclamation and closure successes and challenges of Ermelo Mine Services in
Mpumalanga Province in South Africa are documented and evaluated. It was found that
most of the impacts of the mine on the environment and the surrounding areas were
associated with the operational phase of Ermelo Mines Services. Major impacts and
concerns that arose during the closure were the stability of the mined areas, contamination
of the surrounding area, contamination and pollution in the study and surrounding areas,
particularly of ground water aquifers, visual impacts, particularly of the discard dumps and
slurry dams, the decommissioning of mining shafts, and monitoring the environment
following the mine’s closure.
It is apparent that reclamation has been effective particularly as a private concern
was contracted to undertake aftercare, notably the re-vegetation of the dump. The aftercare
activities have contributed to decreased surface runoff and a reduction in surface and
ground water pollution, as well as greatly reduce dust levels. The implications of the findings
from this study are presented, particularly in view of there being a strong need to develop a
national strategy for mining in South Africa.
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ACKNOWLEDGEMENTS
ACKNOWLEDGEMENTS
I would like to humbly thank God for giving me strength from the beginning until the final
completion of this challenging and rewarding work.
I would also like to extend and convey my sincere gratitude to the following people who
contributed to this dissertation, each in their unique way:
• My supervisor: Prof. K.I. Meiklejohn for his academic support and guidance in
putting this work together.
• My parents, Sampson and Emma Tshivhandekano for the countless moral
support.
• My friend Z.D. Nevondo for providing me with stationery and moral support.
My greatest thanks to the Department of Minerals and Energy, Ingwe Coal Corporation,
Chamber of Mines of South Africa for providing me with the most recent data in relation to
reclamation of coal mines. My final gratitude goes to the University of Pretoria for giving me
logistical support and a great opportunity to further my studies with limited financial
resources.
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University of Pretoria etd – Tsivhandekano, N A (2005)
CONTENTS
TABLE OF CONTENTS
LIST OF TABLES.................................................................................................................................... v
LIST OF FIGURES.................................................................................................................................. v
CHAPTER 1: INTRODUCTION .............................................................................................................. 1
1.1.
Background ...................................................................................................................... 1
1.2.
The Importance of Mining................................................................................................. 4
1.3.
The Impact of Mining on the Environment ....................................................................... 6
1.3.1.
Soil..................................................................................................................... 7
1.3.2.
Water ................................................................................................................. 8
1.3.3.
Dust Pollution .................................................................................................... 8
1.3.4.
Biological Impacts.............................................................................................. 8
1.3.5.
Social and Development Issues ........................................................................ 9
1.4.
Reclamation Philosophies ..............................................................................................10
1.4.1.
Establishing Landuse Objectives ....................................................................10
1.5.
Benefits of Mining Derelict Land Reclamation ...............................................................13
CHAPTER 2: LEGISLATION ................................................................................................................14
2.1.
Development of Mining Environmental Laws in South Africa ........................................14
2.2.
The Minerals Act 1991 ...................................................................................................15
2.3.
Aide-Me’moire ................................................................................................................16
2.4.
Aims of the Environmental Management Program ........................................................17
2.5.
Responsibilities of the Mine Holder................................................................................17
2.6.
Impediments to Legislation.............................................................................................19
2.7.
Other Legislation (United States Reclamation Legislation)............................................20
2.7.1.
Surface Effects of Underground Coal Mining: Minimum Requirements and
Remedies. ......................................................................................................20
2.8.
Utah Coal Regulatory Program (Technical and Findings Review Guide 2002).............21
2.8.1.
General Minimum Requirements of Reclamation of Coalmines .....................21
2.9.
Spoil and Waste Materials..............................................................................................22
2.9.1.
Disposal of Non-Coal Mine Wastes.................................................................22
2.9.2.
Coal Mine Waste .............................................................................................23
2.9.3.
Burning and Burned Waste Utilization.............................................................24
CHAPTER 3: ACADEMIC CONTEXT AND SETTING .........................................................................25
3.1.
Research Problem..........................................................................................................25
3.2.
Aims and Objectives.......................................................................................................25
3.3.
The Purpose of the Study...............................................................................................25
3.4.
The Study Area ..............................................................................................................26
3.5.
Data Collection and Methodology ..................................................................................26
CHAPTER 4: CASE STUDY: RECLAMATION OF ERMELO MINES ..................................................27
4.1.
Reclamation Processes of Ermelo Mine Services .........................................................27
4.1.1.
Reclamation of the Coal Processing Plant......................................................27
4.1.2.
Concrete and Slurry Dams ..............................................................................29
4.1.3.
Reclamation of the Remhoogte Shaft Area.....................................................30
4.1.4.
Tafelkop Shaft Reclamation ............................................................................30
4.1.5.
Major Challenges of the Tweefontein Shaft Reclamation ...............................31
4.1.6.
Tweefontein Reclamation................................................................................33
4.1.7.
Reclamation of the Coal Discard Dump and Associated Remhoogte
Rehabilitated Areas........................................................................................34
4.1.8.
Safe Access to the Dump During and After Reclamation ...............................35
4.1.9.
Suitable Water Management Structures .........................................................35
4.1.10. Minimization of Water Ingress into the Discard Material and Monitoring of
Pollution Plume from the Discard Dump to the Natural Watercourse............36
4.2.
Aftercare of the Reclaimed Areas ..................................................................................39
4.3.
Reclamation of the Water Supply...................................................................................39
4.4.
The Environmental Management Programme Report – Closure Process.....................40
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CONTENTS
4.5.
4.6.
4.7.
Reclamation Challenges For Mining Industry In Reaching Mine Closure......................41
4.5.1.
Key Issues from the Past ................................................................................41
4.5.2.
Future Closure Challenges..............................................................................41
Current Dilemma ............................................................................................................43
The Way Forward...........................................................................................................44
CHAPTER 5: RECOMMENDATIONS ..................................................................................................45
5.1.
Ermelo Mines Services...................................................................................................45
5.2.
Other Recommended Mining Derelict Land Solutions ...................................................46
5.2.1.
Top Soil Conservation .....................................................................................46
5.2.2.
Top Soil Application.........................................................................................47
5.2.3.
Re-vegetation ..................................................................................................48
5.3.
Re-Vegetation Techniques and Landuse.......................................................................49
5.3.1.
Direct Seeding .................................................................................................50
5.4.
Surface Improvement and Covering Systems................................................................50
5.5.
Dilution............................................................................................................................51
5.6.
Simple Coverings ...........................................................................................................52
5.7.
Barrier or Isolating Layers ..............................................................................................53
5.8.
Re-Vegetation of Tailings and Waste Rock Deposit ......................................................54
5.9.
Open Pit Mining..............................................................................................................54
5.10. Management and Aftercare............................................................................................55
5.11. Prevention and Management of Self-Heating (Fires) in Coal Mining.............................56
5.11.1. Best Practice Principles...................................................................................56
5.11.2. Best Methods for Control.................................................................................57
5.11.3. Guiding Management and Fire Control Principles ..........................................57
5.11.4. Top Soil Grafting Averts Self Heating..............................................................58
CHAPTER 6: CONCLUSION ................................................................................................................59
REFERENCES ....................................................................................................................................64
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LIST OF TABLES AND FIGURES
LIST OF TABLES
TABLE 1.1:
Commonly mined materials and end uses (U.S. Bureau of Mines, 2002).................... 4
TABLE 2.1:
Specific aims for the South African Environmental Management Programme Report
(South Africa, 2002). ...................................................................................................18
LIST OF FIGURES
FIGURE 1.1:
South Africa’s mining industry: employment by province (South Africa, 2001a). ......... 6
FIGURE 1.2:
South Africa’s mining industry: Employment by sector (South Africa, 2001a). ............ 6
FIGURE 3.1:
Locality map for the Ermelo Mines complex (Paulsen et al, 2002).............................26
FIGURE 4.1:
Topocadastral Map of Ermelo Mine Surface Infrastructures ......................................28
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INTRODUCTION
CHAPTER 1: INTRODUCTION
1.1.
BACKGROUND
Destructive environmental impacts through mining activity often appear in
newspaper headlines the world over (Mining Magazine, 1995). Some examples of recent of
negative environmental effects from mining that have made media impact are at Summitville,
Colorado, USA; a cyanide leak at Cambria Resource’s Omail Operation in Guyana; the
Austin Gold Venture mine; an unprofitable mine built at high elevations in the Toiyable
Mountains, south of Austin, Nevada, that destroyed a pristine area, and the Mt Hamilton
mine, which destroyed a 10,700 foot mountain in the north end of the White Pine range west
of Ely (Great Basin Mine Watch, 2002).
In South Africa, early mines that have long been exhausted and abandoned are
notorious for their legacy of sterilized and unstable land, fires and acid drainage (South
Africa 2001a).
Many of the previously mined areas in South Africa have not been
rehabilitated, particularly the mine dumps in parts of Mpumalanga, which bear testimony to
the province’s coal mining history (South Africa 2001a); the T&DB Sarga Mines near
Witbank are the typical examples (see Sowetan, 2001).
Perhaps the most well known
evidence for early mining are the towering dumps surrounding Johannesburg that are
monuments to the pioneers and entrepreneurs who uncovered the richest gold deposits in
the world (South Africa, 2001a).
Coal mining has partially contributed to the development of South Africa’s economy,
providing the impetus and fuel for industrialization of what was previously a largely agrarian
country (Baxter & Wicomb, 2000). Coal was, and still is, the predominant energy source for
power stations and during the country’s years of (apartheid) isolation and economic
sanctions, coal conversion technology provided the only legal source of petroleum, oil and
gas (South Africa, 2001b).
The impact of mining activities on the land and the manner in which natural
resources are affected is well documented (Harrison & Hester, 1994). Inadequate mining
regulations, and when existing, their non-implementation in many countries (e.g. South
Africa, Democratic Republic of Congo, Brazil) has meant that mines are often not
rehabilitated after mineral extraction has been completed. Abandoned coal-mines in South
Africa have negatively impact thousands of hectares of agricultural land through subsidence,
underground fires, gas emissions, and surface and ground water discharges (Attewell,
1993). Negative mining impacts are documented to indirectly influence the lives of large
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INTRODUCTION
numbers of people, by curtailing industrial and agricultural development, limiting housing and
infrastructure development and placing ordinary people at risk on a daily basis (Mining
Magazine, 1995).
Unfortunately, derelict mining sites from earlier activities cannot be
“wished away” and require substantial reclamation efforts (Chamber of Mines, 1996). One of
the primary challenges of the world’s mining industry is a pragmatic response to the rapid
evolution of environmental consciousness and the need to protect and conserve natural
resources (Fox, 1984).
Currently, a challenge for the mining industry is how mining and the protection of
the environment can co-exist (Robbins, 1996). South Africa is a perceived world leader in
deep mining, but in many other developing countries (e.g. Democratic Republic of Congo)
mining process are thought to be understood less and there exists a tendency to leave the
environment to fend for itself (South Africa, 2001b). In the nineteen-sixties, ordinary miners
seldom considered the environment and the consequences of their activities thereon
(Chamber of Mines, 1981). However, there has been a recent upsurge in social and political
forces initiated by a concern for the environment (International Committee for Coal
Research, 2000). Environmental concerns are now essential part of governance, particularly
in more “developed” countries (e.g. United States of America, Australia), where stringent
environmental legal frameworks exist (Toy & Griffith, 2001).
The need to reclaim and restore derelict mining lands is now accepted in South
Africa as a priority by the government and other non-governmental bodies (South Africa,
2001a). In certain countries (e.g. United States of America, Britain, Australia), investing in
improving environmental performance, is viewed as providing competitive economic benefits
(World Commission for Environment & Development, 1987). Such countries have accepted
that sustainable development is an integral part of their agenda, and are, therefore, proactively improving environmental performance, without waiting to be mandated to do so
(Parrota & Knowles, 2000). It is, therefore, imperative that mining operations should be
designed, run and maintained to the best professional standards rather than to those ways,
which appear to be the most economic in a short-term view (U.S. Bureau of Mines, 2002).
The focus of the research for this dissertation is the South African coal mining
industry; in particular on the closure of the Ermelo Coal Mine. Two methods for extracting
coal are used in South Africa, namely: surface, open cast and underground mining. Each of
the types of mining, and the abandoned sites that remain after extraction has been
completed, have their own unique environmental problems and challenges that are identified
below (Chamber of Mines, 1999):
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INTRODUCTION
a. Surface mines:
• large-scale landuse change,
• the removal and disposal of overburden,
• the disturbance of hydrology and run-off,
• acid mine drainage,
• visual intrusion,
• noise and blast vibration,
• fly-rock and fugitive dust,
• burning coal discard dumps,
• air pollution,
• transportation/traffic, and
• the stability of the neighbouring network.
b. Underground mines:
• direct damage to the site,
• unstable spoil disposal sites
• spontaneous combustion in spoil disposal sites,
• the creation of large “lagoons”,
• subsidence,
• aquifer disturbance,
• mine water drainage/disposal,
• methane emissions,
• fugitive dust, and
• visual intrusions.
c. Abandoned mines:
• methane migration,
• flooding,
• ground water contamination,
• structural integrity, and
• land rehabilitation.
Coalmines in South Africa have tended to be abandoned, after completion of the
extraction process in a disturbed state, with limited or no reclamation (Baxter & Wicomb,
2000). The abandoned areas influence the lives of large numbers of people by curtailing
industrial and agricultural development, limiting housing and infrastructure development, and
health risks (Austin & Peter, 1971).
Baker et al., (1995) view abandoned mines as
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INTRODUCTION
“eyesores” that have destructive environmental impacts, and are an unwelcome legacy for
the government (local and national), and communities to deal with. The past and, in some
cases, continuing, negative impacts often severely damage the reputation of the mining
industry (Elliot et al., 1996). Mines, as a result, are often unwelcome developments, and
developers are, consequently, often denied access to land, especially where potential
conflicts with the environment are foreseen.
1.2.
THE IMPORTANCE OF MINING
Mining and minerals have an essential role in global development, by raising and
maintaining living standards (Laurence, 2001). Extracting minerals is one of the oldest and
most important human endeavours, because it provides the raw ingredients for most of the
World and, like agriculture, is the lifeblood of civilization (Eagles, 1984). The Earth has
many natural resources on which humans depend, that can be mined (Table 1). Coal, oil,
gas, and other mineral fuels are used for heating, electricity and numerous industrial
processes (Juwarkar et al., 1993) (Table 1). Non-fuel minerals such as iron ore, precious
metals, industrial metals, and non-metallic materials, like sodium and potassium, are used in
chemical and agricultural applications (Griffith et al., 1996) (Table 1). Even the crushed
stone used in road building and other construction projects must be mined. Mining affects
our standard of living and impacts almost everything we do. A variety of items that are use
in homes, offices, transportation, communications, and national defence all require minerals
(U.S. Bureau of Mines, 2002) (Table 1). For example, more than 30 different minerals are
needed to make a single television set or a telephone.
TABLE 1.1:
Commonly mined materials and end uses (U.S. Bureau of Mines, 2002).
Mined material
End uses
Coal
Generating electricity, making iron and steel, manufacturing chemicals
and other products.
Building roads, homes, schools, offices, and factories.
Steel products (kitchen utensils, automobiles, ships, buildings).
Military aircraft, naval vessels, pots and pans, beverage cans.
Electrical motors, generators, communications equipment, wiring.
Electric and electronics circuitry, coins, jewellery, photographic film.
Jewellery, satellites, sophisticated electronic circuits.
Die-casting, galvanizing brass, and bronze, protective coatings on steel,
chemical compounds in rubber and paints.
Batteries, solder, electronic components.
Bricks, paper, paint, glass, pottery, linoleum, concrete, wallboard,
spackling, pencils, microwavable containers, vegetable oil.
Concrete, wallboard, spackling, caulking, potting soil.
Plant fertilizers.
Cooking, drinking water, plastics, and detergents.
Sand and gravel
Iron ore
Aluminium ore (bauxite)
Copper ore
Silver ore
Gold ore
Zinc
Lead
Clay
Gypsum
Phosphate
Salt (halite)
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INTRODUCTION
Minerals are vital to any industrialized nation; the United States uses more than 3.6
billion tonnes of mineral materials yearly, or about 18,000 kg per person, with about half
constituting mineral fuels and the other half being metals and non-metals (U.S. Bureau of
Mines, 2002).
Stable and economic domestic mining, mineral, metal, and mineral
reclamation industries are essential to the economy and a country’s national defence. The
U.S. Bureau of Mines (2002) calculated that the value of processed (non-fuel) materials of
mineral origin produced in the United States in 1994 totalled approximately $360 billion. It is
estimated that during the lifetime of an average American, he or she will use (U.S. Bureau of
Mines, 2002):
• 1,600 kg of aluminium,
• 360 kg of zinc,
• 11,300 kg of clay,
• 25,400 kg of steel,
• 360 kg of lead,
• 680 kg of copper,
• 12,200 kg of copper,
• more than 226,000 kg of coal, and
• more than 453, 000 kg of stone, sand, gravel, and cement.
In South Africa, for more than a century, the mineral industry, largely supported by
gold, diamond, coal, and platinum production, has made an important contribution to the
national economy (South Africa, 2001a). The mining industry has provided the impetus for
the development of an extensive and efficient physical infrastructure, and has contributed
greatly to the establishment of the country’s secondary industry (South Africa, 2001a). In
1999, South Africa produced 55 different minerals from 713 mines and quarries; 44 mines
produced gold, 11 platinum-group minerals, 60 coal and 74 diamonds (Chamber of Mines,
1999). Mineral commodities from South Africa are exported to 87 countries (South Africa,
2001b).
Mining is a major employer in South Africa and mining employment rates vary
considerably in different provinces; 14% of those employed in mining are in the Mpumalanga
province (Fig. 1.1). Given the importance of mining as an employer in Mpumalanga, it is
obvious that the Ermelo case study is significant.
In 2001, South Africa’s mining
employment rate by sector (e.g. employment in the coal mining industry) (Fig. 1.2) was 12%
(South Africa, 2001b).
As previously indicated, the mineral extraction industries play a
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INTRODUCTION
critical role in the vitality of our country’s economy, in our standard of living, and in our
personal lives. It is, therefore, imperative to maintain the co-existence between economic
development (mining) without damaging the environment.
While mining is, by its very
nature, destructive, it should never be an anathema to environmentalism (Kundu & Heiva,
1994).
0.6%
Western Cape
1.7%
KwaZulu-Natal
4.4%
Northern Cape
0.1%
Eastern Cape
9.4%
Limpopo
30.8%
North West
14.0%
Mpumalanga
23.9%
Gauteng
FIGURE 1.1:
15.1%
Free State
South Africa’s mining industry: employment by province (South Africa, 2001a).
Other
Minerals
9%
Diamonds
4%
Gold
52%
FIGURE 1.2:
1.3.
Coal
12%
Platinum
Group
23%
South Africa’s mining industry: Employment by sector (South Africa, 2001a).
THE IMPACT OF MINING ON THE ENVIRONMENT
When mining takes place, particularly in the case of open cast mining, the land is
usually cleared of all vegetation, the landscape drastically altered, and the ecosystem is,
therefore, disrupted (Elliot et al., 1996). If inappropriately managed, mining activities can
also result in significant off-site impacts, particularly from the discharge of drainage
contaminated with sediments, chemicals, metals or altered acidity (Owens & Cowell, 1994).
Mining operations can also introduce pests, predators and diseases into natural ecosystems,
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INTRODUCTION
and can open up isolated areas to further human-induced disturbances (Marcus, 1997).
Mining affects a number of important elements of the environment that are discussed below
(Elliot et al., 1996).
1.3.1.
Soil
The most important part of the land resource is the biological active portion near the
surface, in other words, the soil (Anon, 1997a). Soil provides the rooting medium for plants
and is the source of almost all the nutrients they require (Anon, 1997b). As vegetation
develops to maturity over periods, so does soil; it often take centuries for the soil structure
and fertility develop (Bradshaw, 1983; Anon, 1998b).
Unfortunately the active soil-
vegetation system is easily destroyed or degraded when mining processes produce derelict
land (Anon, 1998b). In open-cast mining the soil is turned upside down and a thin layer of
topsoil is usually contaminated with toxic or hostile substances from deep below the ground
surface and, as a result, vegetative growth is harmed (Richter, 1993).
Mining waste is often dumped in steep-sided spoil heaps: the steep slopes are
unstable and subject to erosion (Bradshaw, 1997). Handling and tipping very often result in
compaction and loss of soil structure; some materials may be very fine and be left loose and
porous (U.S. Bureau of Mines, 2002). Poor drainage or drought, particularly when it occurs
often, exacerbates the already negative impacts of mining (Bradshaw, 1997). The damaged
ground surface conditions may lead to extremes of surface temperature, wind erosion and
sand blasting effects (Anon, 1998b).
Negative environmental impacts from mining often result in an inhospitable physical
environment for plant growth. Added to these effects, are various potential chemical impacts
that may negatively alter spoil characteristics that inhibit plant growth (Bradshaw, 1987),
such as a reduction in nutrients or particular toxic problems (Anon, 1998b). Fresh waste
material usually lacks the soil micro organisms and animals that are responsible for
producing characteristics of soil that render it fertile medium for plant growth (Bradshaw,
1987).
Negative mining impacts on the soil could be overcome if the land is upgraded from
its derelict state so that it is able to support soil development and plant growth, which are
able to support mature and stable plant and animal communities (Bradshaw, 1997).
Successful implementation of rehabilitation procedures allows the substrate to begin taking
on some of the features of a fertile soil (Bradshaw, 1997).
Plants will grow more
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INTRODUCTION
successfully and in turn give rise to residues that will improve the physical and chemical
characteristics of the substrate (Bradshaw, 1987, 1997). The beginning of the successful
renewal of the degraded land resource is the aim of derelict land reclamation (Harrison &
Hester, 1994).
Total extraction of an underground ore body may lead to surface subsidence that
forms pans, and causes water-logging the soil or causes cracks in the overlying strata
through which soil is washed though the breaks in the strata into the underground
excavations to cause subterranean cavities and eventually sinkholes (Environment Australia,
1998). In all cases the water holding capability of the soil is detrimentally affected, resulting
in a lower productivity capability (Street, 1986).
1.3.2.
Water
Water pollution from coal mining presents a more complex problem than the large
physical challenge of reshaping and rehabilitation (Elliot et al., 1996). During mining people
disturb the drainage pattern, which has established and stabilized itself over many years,
thereby causing erosion (Griffith et al., 1996).
Materials are exposed which, although
originally harmless, react with air and/or water to form hazardous wastes that pollute surface
and ground water (Griffith et al., 1996). Polluted water seeps out of the bases of discard
dumps throughout coalfields; it is able to ooze from fissures in hillsides that were mined via
ducts and underground tunnels that are above drainage levels (Richter, 1993).
1.3.3.
Dust Pollution
In South Africa, mine dumps accumulate approximately 400-million tons of residues
annually with a surface area of hundreds of hectares; this results in air pollution by dust,
fortunately this dust has only nuisance value (Chamber of Mines, 1999). In addition, burning
coal dumps and coalmines and stack emission at recovery plants, and smelters are
particularly damaging in the atmosphere (Richter, 1993).
1.3.4.
Biological Impacts
Mining destroys thousands of hectares of natural vegetation and habitat annually,
through the deposit of residues and infrastructure development (Laurence, 2001). Habitats
are directly lost through open cast mineral extraction, and that may have considerable
consequent impacts on the local wildlife (van der Moolen et al., 1998).
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INTRODUCTION
1.3.5.
Social and Development Issues
The environmental and physical impacts of mines are severe and very visible, but
also have a major impact on the lives of the local inhabitants and on the commercial and
social development of the community at large (Bradshaw, 1987). Derelict land problems are
not only concerned with a reduction in usable land surface areas, but also with the derelict
land itself (Bradshaw, 1983). The presence of derelict land can have considerable effects
over a very wide area. Each day, lives are put at risk as men, women and children walk
across dangerous mining sites to reach schools and places of employment (South Africa,
2001a). Severe injuries and fatalities in South Africa have been attributed to people falling in
crown holes or burning areas (South Africa, 2001b).
Mine dumps can dominate an entire landscape, which may be very unsightly
(Attewell, 1993). The material that blows from the heaps may give rise to obvious dust in the
air (Kundu & Heiva, 1994). Waste material that is burnt or catches fire spontaneously (e.g.
coal waste) adds noxious gases to the atmosphere (Kundu & Heiva, 1994).
Old mine
workings can produce large quantities of acid drainage water containing toxic substances in
solution that pollute streams, rivers and lakes (Bradshaw, 1987). Heavy rain can give rise to
flash floods which cause severe erosion of waste heaps and severe contamination of
watercourses (Anon, 1998b). The results of heavy metal mining in Wales, America and
Australia in the last century still have their effects on aquatic organisms of streams that pass
through the area, and there are many areas that are still degraded as result of mining in the
early part of this century (Bradshaw, 1983).
All the above problems can combine, resulting in degraded landscapes. The effect
that such landscapes have on humans often results from an irresponsible attitude towards
the environment in which the community lives, in the form of litter, vandalism and a lack of
planning (Alcoa World Alumina Australia, 2001). A rapid downward spiral of deterioration,
then often takes place (Baxter & Wicomb, 2000). The deterioration can involve the land
values, housing and job opportunities of a whole region (Baxter & Wicomb, 2000).
Economic deterioration can be so great that there is complete collapse of communities
(Bradshaw, 1983).
Similar situations are clearly seen in the coal mining areas of the
Appalachians (Chadwick & Bradshaw, 1980). Therefore, the ultimate challenge of derelict
land problems and land restoration is to counteract all these tendencies and to bring about a
complete environmental renewal. “As people we must learn to base our needs not on death,
destruction, waste, but on renewal” (Berger, 1990:54).
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INTRODUCTION
1.4.
RECLAMATION PHILOSOPHIES
Reclamation in any mining environment requires an overarching philosophy and
rationale (Rainbow, 1987).
If properly implemented, reclamation is one way to achieve
sustainable development (South Africa, 2001a). The success of programs in Great Britain,
United States and the decreasing derelict land surface areas in those countries, suggest that
the reclamation of previously mined land is viable (Cochrane, 2002).
An American
reclamation expert’s maxim was, “If you can’t put it back like it was before you got it out, then
don’t do it”, (Chadwick & Bradshaw 1980:64). The statement embodies the sentiments that
land is a valuable and scarce resource that should be treated with care (Chadwick &
Bradshaw, 1980).
Wasteful use of land, or careless and irresponsible attitudes to land
reclamation, cannot be condoned (Anon, 1998a). Therefore, mining industries across the
globe should adopt the principle of Responsible Care towards the land and to voluntarily
comply with environmental international standards (e.g. the ISO 14OO1). In addition, careful
and thorough planning of landuse after decommissioning of mining operations should form
an integral part of the mining operations (Baxter & Wicomb, 2000).
1.4.1.
Establishing Landuse Objectives
The first task in developing an effective mine reclamation programme is to set a
clearly defined post-mining landuse objective (Alcoa World Alumina, 2001). Reclamation
programmes should be compatible with the surrounding landuse, they should support
species diversity, be consistent with the expectations of the local community, and the
landowners and regulatory agencies must agree to the implementation (Elliot et al., 1996).
An understanding of future landownership is critical (Bradshaw, 1997). Despite the best
intentions, it might not be worthwhile trying to establish a productive landuse like fruit
growing on undeveloped common land because maintenance of an area may become a
major problem after mine decommissioning (Department of Conservation and Land
Management, 1994).
When appropriate landuse objectives are set, then reclamation can commence
(Stephenson & Sanders, 1996). First, the disturbed mined areas need to be returned to a
safe and stable physical state that is integrated into the surrounding landscape (Cochrane,
2002). Safety should be considered in terms of risks to humans, domestic animals and
wildlife, but the rehabilitated site should also reflect the surrounding landscape, if natural cliff
faces or steep and rocky slopes occur locally, these features may be acceptable for
aesthetic or habitat values (Nichols & Gardner, 1998). Stable soils are more likely to revegetate effectively and sustain productivity, and will maintain a protective cover over any
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hostile materials buried beneath them, such as acid-generating rocks or sub soils with toxic
salt or metal concentrations (Fox, 1984). Stable soils prevents many off-site impacts; such
as turbidity (muddiness) and siltation of watercourses (Shankar & Kapoor, 1993). Most
reclamation programmes also involve some form of vegetation establishment (re-vegetation)
(Bradshaw, 1997). Regardless of the landuse objective, the chosen vegetation must be
productive and sustainable (Cook, 1990).
If the vegetation is for commercial use, then
productivity levels need to be competitive with similar enterprises on natural soils (Anon,
1998a).
Where native vegetation is restored, productivity levels must be sufficient to
establish and maintain a self-sustaining ecosystem (Gardner et al., 1991). Restoration of
species diversity can be a critical objective for reclamation programmes aimed at reestablishing native ecosystems (Davies & Bigg, 1995). Success in this endeavour is often
dependent on first establishing the appropriate habitat and ecosystem recovery processes
that will subsequently encourage the full suite of flora and fauna to re-colonize (Gaunt &
Bliss, 1993). Possible landuses that follow successful land reclamation are (Davies & Bigg,
1995):
• the original landuse,
• agriculture,
• forestry,
• fish farming,
• intensive recreation and sport,
• extensive recreation and parks,
• nature conservation and wildlife,
• water storage and supply,
• housing and industry, and
• landfill and waste disposal.
The above are examples of reclamation where land that has been impacted on by
mining operations and has subsequently been restored to its former or an improved
condition (Giammar, 1997). Some experts believe that prior landuse should only serve as a
guide in the development of reclamation and not strictly adhered to as the ultimate target
because most mining regulations set the pre-mine landuse as the main target for restoration
(U.S. Bureau of Mines, 2002).
Plans for using an area after mine decommissioning need not be the catalyst to
begin reclamation, (Whiffen and Walker as quoted by Rainbow, 1987).
Reclamation is
generally undertaken either for economic or for aesthetic (topography inclusive) reasons
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INTRODUCTION
(Rainbow, 1987). The former vary widely and they range from the return to economics use
by agriculture to planning of new industries (Rainbow, 1987). Examples include: housing
development, road construction, increased amenity of the area, development of facilities for
out door recreation and protection against wind and water erosion (Rainbow, 1987). The
latter reason might be solely for preservation of nature and the improvement of visual
impacts. There are many examples of land that has suffered the upheaval of mining and
has been restored to its former use in the same way or in an improved condition (South
Africa, 2001b). Other mining activities have been followed by reclamation to some form of
biological productivity that represents a change in the landuse from its original condition
(Anon, 1997a).
Agricultural land that has been disturbed through mining and tipping operations is
often returned to productive forestry or vice versa (Giammar, 1997). If it is not appropriate to
restore agricultural activity, an area can be restored for recreational purposes (e.g. playing
fields, boating and yachting lakes) to provide amenity areas and public open space to allow
areas to develop for conservation of wild species which can be used for education or to
provide areas for housing, industrial purposes, public services and commerce (Laurence,
2001). Whatever final landuse is adopted following reclamation, it is imperative that it should
fit in to the needs of the surrounding area and be compatible with other forms of landuse that
occur nearby (Krige, 1993a). It is not sensible to establish grazing areas for sheep close to
high density housing where domestic pets are severe threat to farm livestock (Rainbow,
1987). Similarly, it is not appropriate to establish nature reserves in areas where the need is
for recreation and there will be heavy public pressure (Rainbow, 1987).
The eventual landuse following mining must take account of overall plans for the
area (South Africa, 2001b). Further, the objective of reclamation needs careful scrutiny as it
depends on the potential of the mined area and the resulting waste (Harrison & Hester,
1994). The disposal of waste should take account of the orientation and shape of the tips to
be formed and the way in which different waste materials are deployed on site (Chamber of
Mines, 1999). Waste disposal operations require knowledge of the chemical and physical
properties of the waste material; to some extent this knowledge will place constraints on the
formulation of ecological goals for the restored area (Parrota & Knowles, 2000). If the aim of
reclamation is for re-vegetation, it is important to know that certain machinery employed in
excavation and placement could seriously impede root penetration, which is essential for
provision of water to plants, especially during dry seasons (Krige, 1993a). However, if site
operations and re-vegetation procedures are planned well, there will be minimum delay
between the use of the land for mining or waste disposal and its reclamation to some other
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form (Anon, 1997a). Too often, the time that elapses between the beginning of the use of
site for mining or waste disposal and its eventual reclamation to some other use is a period
of many years, so the whole of an area remains unsightly and unproductive (Anon, 1998b).
If the aim of reclamation is for development (i.e. the erection of buildings for
residential or industrial purposes), then the product of soil construction must satisfy the
following below-mentioned requirements (Harrison & Hester, 1994):
• It must be strong enough to support its own weight and the structural load on it.
• It must not settle or deform to the extent of causing damage to the structure on it.
• It must not undergo excessive swelling or shrinkage.
• Its strength must be retained permanently.
• Its physical and chemical characteristics must be environmentally acceptable.
1.5.
BENEFITS OF MINING DERELICT LAND RECLAMATION
Land previously mined should be restored to biological productivity or to a condition
where it can once again be utilized for a range of purposes valuable to a community
(Marcus, 1997). Rehabilitated areas represent a direct improvement of the area on which
the restoration has been carried out (Mining Magazine, 1995). In addition, the surrounding
areas will also improve. The improvement of a site to a condition that integrates well into the
surrounding landscape and removes intrusive landscape characteristics, upgrades the
environment of a region far beyond the confines of the site that is restored (Moffat, 2001).
Visual improvement of the mined out area can begin to upgrade a whole range of
environmental characteristics: the built environment is kept in better repair, road surfaces
and verges become worth maintaining, panning consents are more rigorously considered,
there is less vandalism and the general appearance is respected (Berger, 1990).
To
improvement of a site can be added specific improvements of environmental conditions,
reduction of dust burden in the air, reduction or elimination of gaseous additions to the
atmosphere due to tip burning, reduction of particulate matter and noxious chemicals
deposited in streams and water courses, and elimination of illegal tipping (Berger, 1990).
The transformation that occurs in an area where planned and sensitive land restoration is
practiced enables whole communities and areas to begin to upgrade social and economic
conditions (Paulsen & Naude, 2002). One improvement will follow another and amenities
and facilities are improved (Paulsen & Naude, 2002). However, it is difficult to provide a
cost-benefit analysis of this situation although it is not difficult to find examples of where this
has occurred (Baxter & Wicomb, 2000).
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CHAPTER 2: LEGISLATION
This chapter places emphasis on the gradual development of environmental laws in
South Africa.
In addition, a comparison is made between South African rehabilitation
procedures and those in certain other parts of the World. In South Africa, much of the
driving force behind the development of a consistent environmental policy and its associated
legislation has stemmed from the international environmental law, and is now having to live
and operate within an increasingly complicated and expensive framework of laws and
regulations expressly designed to both protect and improve the environment (South Africa,
2001a).
2.1.
DEVELOPMENT OF MINING ENVIRONMENTAL LAWS IN SOUTH AFRICA
The Mineral and Petroleum Resources Development Act, promulgated on the 1st of
May 2004, is the cornerstone that promotes local, rural, social and economic development in
South Africa (South Africa, 2002). Provision for equitable access to the nation’s mineral and
petroleum resources is enshrined as a principle of the current Act (South Africa, 2002). The
Minerals Act, promulgated in 1991, was a major contributor in promoting optimal exploitation,
processing and utilization of minerals within the constraints of sound environmental practice
(South Africa, 2001a). An important component of all the recent “minerals-related” acts is
adequate financial provision for reclamation during and after mining operations in all South
African mines. However, in the old dispensation there were provisions of the Mines and
Works Act 1956, regulation 5.12.1 and 5.12.2 that required only open-cast mines to submit
rehabilitation programmes to be approved by the DME (Department of Minerals and Energy)
and according to which rehabilitation had to be undertaken (Voogd, 2001). Rehabilitation
was not linked to any mining authorizations and the only penalty one could incur for
defaulting was a fine of R300 (South Africa, 2001b).
With a growing awareness of
environmental conservation worldwide, measures have had to be introduced to bring
irresponsible operators to task and to ensure that all mines rehabilitate the effects of their
mining operations on the environment, minimise pollution, and prevent the destruction of
natural resources (Chamber of Mines, 1999).
Rehabilitation has been given a high priority in the Minerals Act (1991) and the
Mineral and Petroleum and Resources Development Act (2002). The term “rehabilitation” is
incorporated in the concept “environmental management” and is now more encompassing
than previous definitions (South Africa, 2001b).
Stringent requirements have now been
established that deal with the commencement of new mining operations and also to the
closure of old mines (Robbins, 1996). Companies wishing to commence mining must fully
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describe the pre-mining environment, compile a Scoping report, conduct an Environment
Impact Assessment (EIA), and submit an Environment Management Program (South Africa,
2002). Evaluations of fauna and flora and soil types, ground and surface water quality and
quantity, agricultural potential, and archaeological sites must be incorporated into a mine’s
EMPR (Environmental Management Programme Report) (South Africa, 1992). The EMPR
outlines the actions to be taken and standards that are to be achieved in all operational
phases from initiation of mining operations to decommissioning and closure. According to
the International Association for Impact Assessment (IAIA), recognised areas of impact
assessment should include (Voogd, 2001):
• Sustainability,
• Project Evaluation,
• Risk Assessment,
• Environmental Auditing,
• Technology Assessment,
• Social Impact Assessment,
• Health Assessment,
• Demographic Impact Assessment,
• Climate Impact Assessment,
• Ecological Impact Assessment,
• Environmental Impact Assessment,
• Environmental Management Systems, and
• Public Consultation/ Public Participation.
Previously, the Aide-Me’moiré document was used as a guideline to compile an
EMPR, which has to be approved by more than one government department (i.e. Minerals
and Energy, Water Affairs and Forestry, Agriculture, and Environmental Affairs and Tourism,
amongst others) and other relevant authorities. The document was legally binding on the
mining company; therefore, unless a mine’s environmental management system is in order,
a closure certificate will not be issued, and operators will remain liable for rehabilitation of the
disturbed land (South Africa, 2001b).
2.2.
THE MINERALS ACT 1991
The Minerals Act is built on three pillars, namely optimal exploitation, orderly
processing and utilization of minerals (while providing for the safety and health of workers at
mines), and the rehabilitation of land disturbed by mining or any related process (Richter,
1993).
Application and administration of the Act regards each of the three pillars as being
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equal in importance. It is apparent that the DME is now concerned with the introduction of
environmentally protective laws, unlike in the past, when rehabilitation received little or no
attention in the planning of a mining project.
Now, with considerable geological and
technical knowledge at our disposal, the most profitable methods that ensure the safety and
health of workers are carefully considered (Cochrane, 2002). Previously, mining practices
led to endless problems for the Department of Minerals and Energy and the Department was
considered liable when a company went bankrupt or an operator simply disappeared without
rehabilitating a mine (Chamber of Mines, 1999). Currently, because in the Minerals Act
rehabilitation is regarded as important as profits, and safety and health, it forms an integral
part of planning in any mining developments (Cochrane, 2002).
Rehabilitation is now
considered at an early stage of the mining process, when a feasibility study of new mining
project is conducted; the result is that an Environmental Impact Assessment is integral to the
entire operation (South Africa, 2001b). When a mining layout is planned, capital is provided
and during the life of the mine money is set-aside for rehabilitation (South Africa, 2001b).
Therefore, sufficient funds should be available at any point in time to execute the full
rehabilitation programme (South Africa, 2001b).
2.3.
AIDE-ME’MOIRE
The Department of Minerals and Energy (DME) has long realized that it should not
be necessary to burden the mining industries with negotiations with four or five different
departments, each of which has their own agenda for the rehabilitation process (South
Africa, 2001b). A holistic and integrated policy forms part of the DME vision in respect of
rehabilitation of mines. In this regard, guidelines have been established for the preparation
of an Environmental Management Programme Report (EMPR), published as an Aide
Me’moire, to assist prospecting and mining entrepreneurs in the preparation of
Environmental Management Programmes (South Africa, 2001a). The Aide-Me’moire was
intended as a guideline document that aims to achieve the following objectives (South Africa,
1992):
• To meet the environmental requirements and directives of the Minerals Act, No.
50 of 1991, and its regulations;
• To provide a single document that will satisfy the various authorities concerned
with the regulation of the environmental impacts of mining;
• To give reasons for the need for, and the overall benefits of a proposed project;
• To describe the relevant baseline environmental conditions at and around a
proposed site;
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• To describe briefly the prospecting or mining method and associated activities so
that an assessment can be made of the significant impacts that a project is likely
to have on the environment during and after mining;
• To describe how the negative environmental impacts will be managed and how
the positive impacts will be maximized;
• To set out the environmental management criteria that will be used during the life
of a project so that the stated and agreed land capability and closure objectives
can be achieved and a closure certificate can be issued; and
• To indicate that resources will be made available to implement the environmental
management programme.
In terms of the current Act (MPRDA), guidelines supplementing the Aide-Me’moire
have
been
introduced
(e.g.
Environmental
Management
Plan
(prospecting)
and
Environmental Management Plan (mining) to assist the applicants to compile the EMPR
(South Africa, 2002). Applicants are further required to provide details of the quantum and
the financial provision for rehabilitation should be itemized (South Africa, 2002).
2.4.
AIMS OF THE ENVIRONMENTAL MANAGEMENT PROGRAM
The aims of the Environmental Management Programme have been defined by the
Aide-Me’moire for specific categories (Table 2.1) (South Africa, 2002). It is clear that the
aims are to operate in a manner that is as sustainable as possible. However, what are not
included are aims that relate to the implementation of the objectives of the government and
Department of Minerals and Energy policies.
2.5.
RESPONSIBILITIES OF THE MINE HOLDER
The mine holder becomes responsible for compliance with all the provisions of the
Act (MPRDA) relating to rehabilitation. A guiding principle of the controlling legislation is that
the polluter (holder) pays for the costs of rectifying the impacts of pollution (Chamber of
Mines, 1999; South Africa, 2001b). The same ideology is enshrined in the Rio Declaration
on Environment and Development Principle 16: “National authorities should endeavour to
promote the internalization of environmental costs and the use of economic instruments,
taking into account the approach that the polluter should, in principle bear the costs of
pollution, with regard to the public interest and without distorting international trade and
investment” (South Africa, 2001a: 4). Other Acts, administered by departments that also
have a bearing on mine rehabilitation, are the Water Act (1956), Atmospheric Pollution
Prevention Act (1965), Conservation of Agricultural Resources Act (1983), Environmental
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Conservation Act (1989), and the National Environmental Management Act (1998)
(Cochrane, 2002).
TABLE 2.1:
Specific aims for the South African Environmental Management Programme Report
(South Africa, 2002).
Aspect
Aim
Soil
To prevent subsidence and to establish stable land, profiled in such a way to
prevent erosion and to prevent the pollution of both surface and groundwater by
contact with contaminated water or potentially contaminant spoil or substances,
creating land capable of achieving the predetermined, post-mining productivity and
usage as close as possible to the pre-mining conditions.
Water
To establish a water management system that prevents erosion and the
contamination and wastage of water resources and ensures compliance with the
water quality management objectives as determined by the department of Water
Affairs for the specific catchments area.
Air
To prevent dissemination of any form of pollution (including noise) emanating from
any mining related process, operation or residue. Therefore attention is drawn to
the rehabilitation of slimes dams and especially to the angle of outer walls that have
a direct bearing on the permanence of the rehabilitation measures, particularly in
respect of erosion and vegetation. It is important to achieve a stable and permanent
cover on the dams and dumps.
Vegetation
To establish a stable vegetation cover, capable of natural survival and propagation.
Final Closure
To successfully adhere to all the requirements of the Mineral and Petroleum
Resources Development Act in order to obtain the closure certificate.
Result
To leave the rehabilitated land as close as possible in a maintenance-free state,
aesthetically acceptable and usable for future generations.
Stringent environmental control systems are necessary in South Africa for the
sustainable utilisation of the country’s natural resources (Baxter & Wicomb, 2000). While it
is accepted that mine operators transgressing the law should be prosecuted (Baxter &
Wicomb,2000; Cochrane, 2002), the intention of legislation is that disputes are settled
through negotiation and consensus (Baxter & Wicomb, 2000). The aim of mining laws in
South Africa is that those involved in mining, even in the tentative stage of prospecting, will
not be able to avoid a direct environmental responsibility (Krige, 1993b). It is intended that
policy and principles are accepted and implemented throughout the entire life of a mine.
Realizing that mines have finite lives, are place bound, and impact on the physical
environment, the industry needs a strong commitment to protecting the environment
(Attewell, 1993). In order to achieve an adequate balance between development and the
environment, the objectives of a mining company should be clearly stated and be
measurable in terms of environmental quality and quantity (South Africa, 2001a).
The
realisation is that mining in South Africa is part of “a new game with new rules” (Cochrane,
2002: 32); “the game” should be played in a transformed industry that aims to use the
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country’s mineral wealth in a more accountable and responsible manner towards the
environment (Cochrane, 2002). Mining companies should, therefore, not be defensive, but
explain their policies, discuss environmental issues and involve the people (Chamber of
Mines, 1999).
2.6.
IMPEDIMENTS TO LEGISLATION
In many Third World countries, poverty is cited as the main reason for the disregard
of environmental legislation (United Kingdom, 1989). The concern is that “if third world
countries adopt the type of stringent environmentalist policies Western countries now
pursue, third world countries will never attain the hope of faster development” (Shankar &
Kapoor, 1993:27). On the other hand, people who are hungry are seldom concerned about
the aesthetics of nature and are not moved by an ideal of ensuring sustainable development
so that future generations are not compromised; “they care more about today’s dinner and
tonight’s shelter” (Baxter & Wicomb, 2000:45). At present, the Third World is absolutely
dependent on Western finance, markets and technology (Anon, 1997a). Such dependence
gives leverage to the environmental levers; it could, therefore, be suggested that
environmental conditionality be attached to loans and perhaps even private bank loans. It is
an unfortunate reality that so-called “Developed Nations” have an unfair advantage over
under-developed countries and are, therefore, able to exhaust Third World natural resources
(Anon, 1997b). It is unlikely that existing unfair international trade practices will be easily
relinquished (Anon, 1997b). As a result of the unfair trade practices, environmental controls
are viewed by some countries with hostility. Even though South Africa and many developing
countries are on a learning curve in terms of the environmental protection, it is clear that
these countries do not wish to follow or emulate the Western path (Anon, 1997a).
One of the most serious problems encountered in South Africa is that insolvency of
mining companies and the insolvency laws superseded the Minerals Act in Section 38(2)
(Cochrane, 2002). The insolvency of companies is still one of the problematic obstacles the
department of Minerals and Energy is facing today; for example, a company “Rand London”
with mining enterprises in a number of South African areas was liquidated in London.
However, all its operating mines were successfully making profits in South Africa.
In
KwaZulu-Natal, there are three collieries owned by “Rand London” that are now state
entities, namely, Zoetmelksvlei, Kempslutand Aloe Minerals, but have apparent financial
liabilities of approximately R20 million (Cochrane, 2002).
When a mining company runs into financial difficulties, the easiest option in South
Africa is to liquidate and move into another region where the mining Directors would start a
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new company (South Africa, 2001b). All of the above experiences of the past have resulted
in the development of the new Minerals and Development Bill, where not only companies,
but the Directors, whether from the company or the State, will be held responsible for
disturbance to the environment and water resources (South Africa, 2001a). Therefore, the
state has ensured that it does not inherit the liabilities of rehabilitation by ensuring that
adequate financial provision is in place equal to the disturbance created. Mining houses
now seeking mining rights are required to ensure that adequate financial provision is made
for rehabilitation after their activities have been concluded (South Africa, 2001b).
The
concept of creating a National State Rehabilitation Fund is also being considered (South
Africa, 2001a).
2.7.
OTHER LEGISLATION (UNITED STATES RECLAMATION LEGISLATION)
In the United States, each state is responsible for its mining policies, although all
environmental regulations must be in agreement with federal Environmental Protection
Agency (EPA) policies (U.S. Government’s Bureau of Land Management, 2001).
2.7.1.
Surface Effects of Underground Coal Mining: Minimum Requirements and
Remedies.
According to US regulations on coal mining, the Regulatory Authority promulgates
rules and regulations directed toward the surface effects of underground coal mining
operations, and embodying the following requirements (U.S. Bureau of Mines, 2002). In
adopting any rules and regulations, the Regulatory Authority considers the distinct
differences between surface coal mining and underground coal mining. Each permit issued
and relating to underground coal mining requires that operators (U.S. Government’s Bureau
of Land Management, 2001):
• adopt measures consistent with available technology to prevent subsidence that
may cause material damage, except where the mining methods used require
planned subsidence in a predictable and controlled manner. It is clearly stated
that this does not prohibits standard room and pillar mining methods.
• seal all entrances and openings between the surface and underground mine
working when they are no longer required for mining operations.
• fill or seal exploratory holes no longer necessary for mining, while, where
possible returning mine and processing waste, tailings and any other waste from
the mining operation, to the mine workings or excavations.
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• stabilise all waste piles through construction in compacted layers using
incombustible and impervious materials and also ensure that leachate will not
degrade waters below accepted water quality standards.
• ensure that the topography of the waste accumulation is compatible with natural
surroundings and that the site is stabilized and re-vegetated appropriately.
• operate all existing and new coal mine wastes according to the standards and
criteria developed by the regulatory authority.
• establish permanent vegetative cover, capable of self-regeneration and plant
succession that is at least equal in extent of cover to the natural vegetation of the
area following mining operations.
• protect offsite areas from damages that may result from mining operations.
• eliminate fire hazards and otherwise eliminate conditions that constitute a hazard
to health and safety of the public.
• minimize hydrologic disturbances at the mine site and in associated offsite areas
during and after coal mining operations and during reclamation.
2.8.
UTAH COAL REGULATORY PROGRAM (TECHNICAL AND FINDINGS REVIEW GUIDE 2002)
As already indicated above each State in the United States is responsible for its
own environmental regulations. The Utah Coal Regulatory Program will be outlined and
minimum requirements in terms of reclamation procedures will be examined.
2.8.1.
General Minimum Requirements of Reclamation of Coalmines
A mine operator must provide a plan for the reclamation of the lands within the
proposed permit area, showing how the applicant will comply with the regulatory program
and the environmental protection performance standards (United States of America, 2002).
The plan should include, at a minimum, the following information for the proposed permit
area (United States of America, 2002):
• a detailed timetable for the completion of each major step in the reclamation
plan,
• a detailed estimate of the cost of the reclamation of the proposed operations
required to be covered by a performance bond, with supporting calculations for
the estimates, and
• a plan for the backfilling, soil stabilization, compacting and grading, including
contour maps or cross sections that show the anticipated final surface
configuration of the proposed permit area.
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• a plan for the redistribution of topsoil, subsoil and other material, along with a
demonstration of the suitability of topsoil substitutes or supplements, should be
based upon analysis of the thickness of soil horizons, total depth, texture,
percent course fragments, pH, and area extent of the different kinds of soils,
other chemical and physical analyses, field-site trials, or greenhouse tests if
determined to be necessary or desirable to demonstrate the suitability of the
topsoil substitutes or supplements may also be required (U.S. Government’s
Bureau of Land Management, 2001).
• a plan for re-vegetation including, but not limited to, descriptions of the schedule
of re-vegetation, species and amounts per acre of seeds and seedlings to be
used, methods to be used in planting and seeding, mulching techniques,
irrigation, if appropriate, and pest and disease control measures, if any,
measures proposed to be used to determine the success of re-vegetation, and a
soil testing plan for evaluation of the results of topsoil handling and reclamation
procedures related to re-vegetation (Marcus, 1997).
• a description of the measures to be used to maximize the use and conservation
of the coal resource, a description of measures to be employed to ensure that all
debris, acid-forming and toxic-forming materials, and materials consisting a fire
hazard are disposed of accordingly and a description of the contingency plans
which have been developed to preclude sustained combustion of such materials
(Marcus, 1997).
• a description including appropriate cross sections and maps of the measures to
be used to seal or manage mine openings within the proposed permit area.
• a description of steps to be taken to comply with the requirements of the Clean
Air Act, the Clean Water Act, and other applicable air and water quality laws and
regulations and health and safety standards (U.S. Bureau of Mines, 2002).
2.9.
SPOIL AND WASTE MATERIALS
Specific regulatory requirements are specified for the management of mine wastes
in Utah (United States of America, 2002); these are discussed below.
2.9.1.
Disposal of Non-Coal Mine Wastes
Non-coal mine wastes that include, but are not limited to grease, lubricants, paints,
flammable liquids, garbage, abandoned mining machinery, lumber and other combustible
materials generated during mining activities should be placed and stored on a controlled
manner in a designated portion of the permit area (United States of America, 2002).
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Placement and storage should ensure that leachate and surface runoff do not degrade
surface or ground water, that fires are prevented, and that the area remains stable and
suitable for reclamation and re-vegetation compatible with the natural surroundings
(Giammar, 1997).
Final disposal of non-coal mine wastes should be in a designated disposal site in
the permit area or a State approved solid waste disposal area. Disposal sites in the permit
area should be designed and constructed to ensure that leachate and drainage from the
non-coal mine waste area does not degrade surface or underground water. Wastes should
be routinely compacted and covered to prevent combustion and windborne waste. When
the disposal is completed, a minimum of 2 feet of soil cover should be placed over the site,
slopes stabilized and re-vegetated. Operation of the disposal site should be conducted in
accordance with all local, State and Federal requirements. At no time should any non-coal
mine waste be deposited in a refuse pile or impounding structure, nor should any excavation
for a non-coal mine waste disposal site be located within 8 feet of any coal outcrop or coal
storage area. Any none-coal mine waste defined, as “hazardous” should be handled in
accordance with the requirements of any implementing regulations.
2.9.2.
Coal Mine Waste
Reclamation of coal mines should contain descriptions, including appropriate maps
and cross-section drawings of the proposed disposal methods and sites, for placing
underground development waste and excess spoil generated at surface areas affected by
surface operations and facilities (United States of America, 2002). Each reclamation plan
should
describe
the
geotechnical
investigation,
design,
construction,
operation,
maintenance, and removal, if appropriate, of the structures (Giammar, 1997).
All coalmine waste should be placed in new or existing disposal areas within a
permit area. Coal mine waste should be placed in a controlled manner to (United States of
America, 2002):
• minimize adverse effects of leachate and surface-water runoff on surface and
ground water quality and quantity;
• ensure mass stability and prevent mass movement during and after construction;
• ensure that the final disposal facility is suitable for reclamation and re-vegetation
compatible with the natural surroundings and the approved post-mining landuse;
• not create a public hazard; and
• prevent combustion.
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LEGISLATION
Coal mine waste materials from activities located outside a permit area may be
disposed of in the permit area only if approved by the relevant authority. The disposal facility
should be designed using current, prudent engineering practices and should meet any
design criteria established by the Division (Griffith et al., 1996).
2.9.3.
Burning and Burned Waste Utilization
Coal mine waste fires should be extinguished by the person who conducts the
surface mining activities, in accordance with a plan approved by the Division and the Mine
Safety and Health Administration (United States of America, 2002).
The implemented
management plan contains, at minimum, provisions to ensure that only those persons
authorized by the operator, and who have an understanding of the procedures to be used,
should be involved in the extinguishing operations. No burning or unburned coalmine waste
may be removed from a permitted disposal area without a removal plan approved by the
Division. Consideration is given to potential hazards to persons working or living in the
vicinity of the structure (United States of America, 2002).
After carefully conducting a literature review of coal mine reclamation in other
countries, it is now possible to redirect reclamation challenges that mining companies face in
South Africa. In order to improve or minimise the environmental impacts in the South African
mining industry, research in the form of a case study (Ermelo Mine Services) was conducted
and the research procedures, aims and objectives, the study area and data collection and
methodology will be discussed in the next chapter, followed by the research case study.
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ACADEMIC CONTEXT AND SETTING
CHAPTER 3: ACADEMIC CONTEXT AND SETTING
3.1.
RESEARCH PROBLEM
The study aims to investigate identified problems relating to mine rehabilitation in
South Africa; the country is faced with many major problems, some of which are (South
Africa, 2002):
• abandonment of mining areas without rehabilitation,
• inadequate Environmental Impact Assessment before, during and after mine
closure,
• lack of adequate management of identified impacts,
• inadequate financial provision for rehabilitation, and
• a lack of monitoring and aftercare systems after post mine closure.
3.2.
AIMS AND OBJECTIVES
Ermelo Mines are used as an example to investigate reclamation in the South
African mining industry; at a superficial level it was seen as being representative. The
general aim of the study is to evaluate the closure and rehabilitation of Ermelo mines and to
specifically:
• verify whether an Environmental Impact Assessment was conducted and how
the identified impacts were managed;
• evaluate monitoring and aftercare systems after post mine closure;
• contextualise issues at Ermelo mines with the whole mining industry in South
Africa, and
• provide recommendations for a national strategy for reclamation and closure of
mines.
3.3.
THE PURPOSE OF THE STUDY
In South Africa, environmental problems especially in mining industries are diverse
and escalating; therefore, the purpose of the study is to compile a documentation of the
successes and failures of the closure of Ermelo Mine Services and provide a foundation for
other South African mining companies to develop models for reclamation and closure. In
addition, recommendations for amendments to the existing reclamation and closure policies
are made in order to provide for a continual progression of environmental improvement in
the mining industry.
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ACADEMIC CONTEXT AND SETTING
3.4.
THE STUDY AREA
Ingwe Ermelo Mines Services is located between Bethal and Ermelo in the
Mpumalanga Highveld, in Tafelkop farm district in an area dominated by farming (Fig. 3.1).
The study site lies within the Ermelo magisterial district and access to the mine is gained via
the N17 and N11 routes. Ermelo Mines specialised in C lower seam bituminous coals
(South Africa, 2002); the extraction of coal was conducted using an underground mining
method and mechanized conventional coal extraction methods were used (Naude, 2002).
3.5.
DATA COLLECTION AND METHODOLOGY
The study was qualitative in nature; interviews were held with selected officials:
• directors of the rehabilitation division,
• coal specialists,
• local authorities,
• interested and affected people ,and
• waste management personnel in the government as well as in Ermelo mine
services were interviewed.
Breyten
Study Area
Davel
Ermelo
Mines
BETHAL
ERMELO
Mining Areas
0
Diggings
FIGURE 3.1:
5
10 km
Locality map for the Ermelo Mines complex (Paulsen & Naude, 2002).
Site visits and spot check observations were also conducted at the mine.
Supporting documents (e.g. surface subsistence study conducted by D.C. Oldroyd, geology
study of the study area conducted by G.W. Blunden and the interested and affected parties
meeting co-ordinated by Jannie Cronje and Amanda van Wyk) to the EMPR were examined
and evaluated. The information relevant to the study is presented in the following chapter.
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CASE STUDY: RECLAMATION OF ERMELO MINES
CHAPTER 4: CASE STUDY: RECLAMATION OF ERMELO MINES
The emphasis in this chapter is on how Ermelo Mines Services tackled the
challenges associated with reclamation following their decommissioning. As the mine was
no longer producing coal, the most critical issue was to ensure that the remaining land
should be rehabilitated so that it can once again be useful for future developments (Naude,
2002). Different reclamation methods were tried and those deemed fit were implemented in
order to return the disturbed mining area to an environmentally friendly site that is
sustainable and that can be useful to the future generations (Paulsen & Naude, 2002).
Ermelo Mine closure is still in process (no time frames for closure have been
announced) and the mine committed itself to reclaim the affected mining areas to the
satisfaction of the State and affected parties (Paulsen & Naude, 2002). After cessation of the
Ermelo Mine’s production phase, the following reclamation issues were attended to using
various reclamation methods (Viljoen, 2002) (see Fig. 4.1 for orientation):
• The coal processing plant was demolished and reclaimed.
• The Remhoogte main shaft was closed and demolished.
• The Tafelkop shaft complex with its infrastructure was closed and reclaimed.
• The Tweefontein shaft complex with its inclined shaft and buildings was
reclaimed.
• The ventilation shafts were closed and reclaimed.
• The coal discard dump presented a black ugly spot, which had to be reclaimed.
• Water supply affected by mining activities had to be remedied.
Each of the above challenges required specific reclamation methods and offered
unique challenges that were outlined in the documentation of the processes (Paulsen &
Naude, 2002).
4.1.
RECLAMATION PROCESSES OF ERMELO MINE SERVICES
The processes discussed below form part of the reclamation processes which were
implemented or conducted by Ermelo Mine Services; each site-specific reclamation process
will be examined closely but separately.
4.1.1.
Reclamation of the Coal Processing Plant
Although the coal processing plant required a sizeable chunk of work to rehabilitate,
it also contained assets, which could be turned into capital to fund some of its rehabilitation
liabilities (Paulsen & Naude, 2002). The liability was mainly the demolition of the structures,
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CASE STUDY: RECLAMATION OF ERMELO MINES
cleaning up of the dirty surroundings associated with the plant, rehabilitating the slurry dams
used as silt traps when the mine was operating and reclamation of the stockpile areas
(Viljoen, 2002).
FIGURE 4.1:
Topocadastral Map of Ermelo Mine Surface Infrastructures
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CASE STUDY: RECLAMATION OF ERMELO MINES
Buildings that were previously used as offices, workshops and a training centre,
offered ideal opportunities for future use (Naude, 2002). The main mine complex, the silos
and associated conveyor system was not demolished but sold to an entrepreneur who
intended to utilize it as a storage facility for grain (Paulsen & Naude, 2002). Silos had to be
cleaned out before being handed over to the future owner (Naude, 2002). The bottom
sections of the silos were filled with coal. Initial attempts to loosen the coal containing
material in the bottom of the silos by blasting were not successful (Paulsen & Naude, 2002).
The eventual method employed was to lower bobcats into the silos and excavate the
material to the chute opening in the structures floor (Paulsen & Naude, 2002). To get these
bobcats into the silos, a suitable mobile hydraulic crane had to be brought to the site to place
and move them from the one silo to the other (Paulsen & Naude, 2002). The loose material
was removed though the chutes at the bottom and the silos were washed to free them of any
coal containing material (Naude, 2002)
4.1.2.
Concrete and Slurry Dams
Concrete dams were used as thickeners and dirty water reservoirs; the coal slurry
from the plant area was washed into the dams (Viljoen, 2002). The recovery of the plant
equipment demanded careful planning and execution; after salvaging from the plant,
equipment was stacked and stored in such a way that it could easily be found for potential
customers to view (Naude, 2002). Where possible, the equipment was accompanied with a
service history and associated literature (Naude, 2002).
Corrugated iron from the plant building was also stripped and sold (Paulsen &
Naude, 2002). A demolition company used a technique called jet blasting to collapse the
main support beams to bring down the plant building (Viljoen, 2002). Excavators fitted with
grabs then separated the steel beams from the heap to cut it up in short pieces of steel
(Viljoen, 2002). The steel was sold to scrap metal merchants (Naude, 2002). Once the steel
was successfully removed, coal debris and concrete foundations were all that remained
(Naude, 2002). The coal debris was removed and buried more than a meter below the
surface (Paulsen & Naude, 2002). Concrete foundations were demolished with hydraulic
peckers, mounted on the booms of excavators (Paulsen & Naude, 2002).
The raw coal and product coal stockpiles had to be reclaimed by shaping the areas
to be free draining and then covering the area with a layer of topsoil (Naude, 2002). Slurry
dams were no longer needed for their intended purpose and many were still very wet,
making rehabilitation difficult (Viljoen, 2002). Rehabilitation involved first shaping the walls
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CASE STUDY: RECLAMATION OF ERMELO MINES
of the dams into the dams to flatten the area (Viljoen, 2002).
The dams were then
demolished to prevent ponding or wet spots when the area was completely reclaimed
(Viljoen, 2002). When the shaping process was completed, the area was covered with a
layer of topsoil (Paulsen & Naude, 2002). The final part of reclamation was the re-vegetation
the area so that the area was ready for use by the future owner (Paulsen & Naude, 2002).
4.1.3.
Reclamation of the Remhoogte Shaft Area
The Remhoogte shaft comprised sturdy concrete with a wide underground entrance
(Naude, 2002).
There was reluctance to demolish the shaft, which jeopardised the
demolishing process (Paulsen & Naude, 2002). The winder conveyances, ropes and winder
propelling gear were reclaimed (Naude, 2002). Once the valuable items were salvaged, the
shaft headgear was demolished and dropped into the vertical shaft (Paulsen & Naude,
2002). All surrounding concrete rubble, which emanated from the demolition process, was
dropped down the shaft (Paulsen & Naude, 2002).
The Remhoogte shaft area was not properly rehabilitated because the rubble
materials used as filling was insufficient to stabilise the area (Chamber of Mines, 1999).
International reclamation standards require that all portals, entryways, drifts, shafts and other
openings between the surface and underground mine workings, should be sealed properly
when not required (United States of America, 2002). A beacon was placed in the centre
position of the shaft to mark its original position; a requirement for shafts that are closed
(South Africa, 2001a).
The buildings associated with the Remhoogte shaft were not
demolished as they formed part of the complex sold to a private entrepreneur (Naude,
2002).
4.1.4.
Tafelkop Shaft Reclamation
The Tafelkop shaft complex was rehabilitated by clearing of all structures
associated with mining (Naude, 2002). First, the vertical shaft was stripped of the winder
conveyances, ropes and winders (Naude, 2002). The steel headgear was taken down and
sold as scrap metal (Naude, 2002). It was imperative to separate metal from other rubble,
because corrosion may adversely effect the environment (United States of America, 2002).
International standards require that non-coal mine wastes should be placed in a designated
disposal site in the permit area or a state approved solid waste disposal area (Chamber of
Mines, 1999). All concrete foundations and concrete slabs at Tafelkop were destroyed and
dropped down the shaft together with contaminated soils and material (Viljoen, 2002).
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International reclamation standards require that all contaminated soil and materials
should be separated and buried with a protection layer to minimise the contamination of the
mine site and the associated offsite mine areas (U.S. bureau of Mines, 2002). The Tafelkop
area was shaped to smooth the contours, so that the landscape fitted visually with the
surrounding areas (Naude, 2002; United States of America, 2002). The next step was to reestablish vegetation. A vegetation contractor re-vegetated the area and established the
grass (Viljoen, 2002); currently the area cannot be recognised as a previous mine shaft
complex.
4.1.5.
Major Challenges of the Tweefontein Shaft Reclamation
The Tweefontein shaft complex required reclamation of the following structures
(Paulsen & Naude, 2002):
• closure of the incline shaft;
• removal of the surface conveyor system and bins;
• clearing of refuse and unsightly mining remnants; and
• shaping of the steep and unsightly slurry dam area.
The incline shaft was closed by constructing a plug wall in the shaft entrance a few
meters below surface (Viljoen, 2002). The area above the shaft plug wall was then filled with
soil (Naude, 2002). Part of the closure process was to monitor the methane concentrations
in the mine (Viljoen, 2002). Methane gas was first allowed to rise through the explosive
range before it was considered safe. At the shaft plug, measuring pipes were installed to
measure the methane content (Naude, 2002). The methane level rose as expected at the
Tweefontein shaft area (Naude, 2002). Methane started leaking past the plug wall and some
methane was measured in the shaft buildings (Paulsen & Naude, 2002).
The rise of
methane level could result in an unsafe situation if not addressed timeously. A problem was
that the buildings were earmarked for use by a local farmer and they obviously had to be
transferred to the new owner in a safe condition (Viljoen, 2002). International reclamation
standards require that the mine out area should not cause the health hazards to the
community (Mining Magazine, 1995).
The following dynamic processes could potentially have led to the reduction of free
space in the underground workings at the Ermelo Coal Mine (Naude, 2002):
• Water seeping into the mine through the rock strata. This is a slow process but
reduces the amount of open space of underground mine workings.
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CASE STUDY: RECLAMATION OF ERMELO MINES
• If methane gas in the mine was released from the rock strata and escaped into
the open space of the mine workings.
• If natural barometric changes associated with changes in the weather conditions,
caused continuous pressure fluctuations in the underground workings.
The
result would have been that the mine could “breath in” fresh air (containing
oxygen) and release methane gas when the pressure inside the mine workings
became higher than the ambient pressure outside the mine workings (Naude,
2002). Methane gas is lighter than the other gasses and can, therefore, be
found in the higher spaces, and as such it will be released first into the
atmosphere (Toy & Griffith, 2001). The danger of oxygen entering the mine is
that oxygen is one three components (oxygen, fuel and heat/spark) that
commonly cause explosions (Schab & Postma, 2002). It was, thus undesirable,
to have fresh oxygen entering the mine (Chamber of Mines, 1999).
The following measures were introduced to solve the problem of free space
reduction in the Ermelo Coal Mines (Viljoen, 2002):
• The shaft area where the gas leaked through was inspected thoroughly and it
was found that the sidewalls of the shaft were initially constructed using hollow
cement bricks. Although the plug was properly sealed against the sides of the
shaft, the methane gas escaped into the atmosphere through a conduit in the
hollow bricks. The hollow bricks, from the plug to the collar of the shaft were
removed, and the area was sealed with soil suitably compacted to resist the
pressure from the gas.
• A monitoring borehole was opened to sample the water; a pressure release of
gas (mostly methane) could potentially have escaped from the borehole. In itself
the gas from the borehole could have resulted in an unsafe situation. The other
problem is that the instruments used to sample water could have been rendered
ineffective when dropped down the borehole, as the upward flow of gas may
potentially have been sufficient to keep the instrument in suspension, preventing
the sampler from taking the required samples. As such, it was necessary to
provide pressure release points to cope with the continuous reduction of open
space of the underground working which caused the pressure to rise.
• Special gas release valves were installed to release gas from the mine. The aim
remained to increase the methane concentration of the gas in the mine (to get
through the explosive range). To achieve the optimum build-up of methane and
simultaneous release of pressure, the gas release valves were installed in
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CASE STUDY: RECLAMATION OF ERMELO MINES
carefully selected positions in the mine to withdraw gas with a relatively low
concentration of methane (Viljoen, 2002). Three boreholes were drilled for this
purpose. One was positioned just above the water level; another was placed
higher up on the roof contours of the mine, while the third was placed at a
position presenting the highest position of the mine above the mean average sea
level (Viljoen, 2002). The gas with relatively low methane concentrations was,
thus, released to the atmosphere while the lighter methane was trapped in the
higher lying areas of the mine (Viljoen, 2002). The gas release boreholes were
constructed with a dual function; their primary purpose was to release gas, and
second, when the water level reaches the borehole, they allowed water
monitoring from the same borehole (Naude, 2002).
4.1.6.
Tweefontein Reclamation
During the life of a mine, a considerable amount of scrap, rubble and carbonaceous
material accumulates on the site (Paulsen & Naude, 2002). During reclamation, unwanted
materials must be removed and the area cleared up. Generally, the ferrous metals are
gathered and sold, but the non-usable materials and scrap are buried (U.S. Bureau of Mines,
2002). This was applied to Tweefontein and it can be argued that the reclamation processes
were, therefore, in accordance with the international standards. The shaft was properly
sealed, conveyors were removed, and the ventilation fan complex was cleared as required.
The side slopes of the slurry dams were shaped to better withstand possible soil erosion
(Paulsen & Naude, 2002). In the process, debris such as building rubble, pieces of conveyor
belt and old steel wire rope were unearthed, and then re-buried, one meter below the
surface (Paulsen & Naude, 2002). Redundant concrete foundations were also demolished
and buried one meter below the surface (Naude, 2002). Burying the scrap one meter below
the surface made it possible to work the area afterwards with farming implements (Viljoen,
2002).
The ventilation shafts at Tweefontein were reclaimed (Paulsen & Naude, 2002).
The bulky fans had to be dismantled and removed and thereafter sold (Naude, 2002). The
shafts were then sealed; sealing of all orifices into the mine is an important step to prevent
exchange of oxygen and methane through the entrances in order to get the underground
gas concentration through the explosive range (Naude, 2002).
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CASE STUDY: RECLAMATION OF ERMELO MINES
4.1.7.
Reclamation of the Coal Discard Dump and Associated Remhoogte
Rehabilitated Areas.
Discard dumps are generally the most prominent visible features remaining after a
mine closes down (South Africa, 2001a), and can result in pollution problems if not
rehabilitated correctly (Chamber of Mines, 1999). Pollution is generated from a dump if rain
water is allowed to infiltrate the discard material with the consequential effects of water being
contaminated as it migrates through the discard material and eventually decants on the toe
line of the dump as a high saline and normally as low pH water (International Committee for
Coal Research, 2000).
Proper reclamation can, however, reduce the negative effects
associated with discard dumps (Chamber of Mines, 1999). Insufficient reclamation prevents
a mine from obtaining the closure certificate (South Africa 2001b).
An un-rehabilitated
discard dump associated with a mine can tarnish the image of the mining group, as the
discard dump is directly associated with the mine (Viljoen, 2002). Rehabilitated dumps are
image boosters (Viljoen, 2002). The purpose of the reclamation of the mine’s discard dump
is to turn the mine into something useful for the future; a self-sustainable project (Naude,
2002).
In this regard, the Ermelo Mines Services discard dump was demarcated for
agriculture, specifically livestock grazing (Naude, 2002).
The construction of the discard dump during the operating life of the mine can vastly
reduce the amount of shaping required for a discard dump when the final reclamation has to
be undertaken (Laurence, 2001). In the case of the Ermelo Mines Services discard dump
construction was planned in such a way that the efforts in final shaping were reduced
considerably (Paulsen & Naude, 2002).
The Ermelo Mine Services discard dump was
designed, located, constructed, modified, and rehabilitated in accordance to the reclamation
standards and criteria developed pursuant to the international authority’s regulations
(Paulsen & Naude, 2002).
Reclamation of the Ermelo discard dump required proper design to ensure (Naude,
2002):
• safe access to the dump during and after reclamation;
• suitable water management structures on the discard dump and from the discard
up to the natural water courses;
• minimisation of water ingress into the discard material and monitoring of pollution
plume from the discard dump to the natural water courses;
• topsoil and vegetation requirements; and
• topsoil borrow-pit design.
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CASE STUDY: RECLAMATION OF ERMELO MINES
4.1.8.
Safe Access to the Dump During and After Reclamation
Safety is a priority when a dump is being constructed and when aftercare on the
dump is undertaken (South Africa, 2001b). The final shape of a discard dump plays a major
roll in enhancing safety (Laurence, 2001). In addition, if the long-term safety of the dump is
not addressed in the design, it may then happen that the successor utilising the dump may
encounter an accident or hazardous situations (Chamber of Mines, 1999). The purpose of
appropriated design is to cater for the long-term use of the dump (Viljoen, 2002). The
maximum inclination of the side slopes plays an important role in the safety of a dump.
Naude (2002) stated that the Ermelo Mines side slopes were shaped to have a maximum
gradient of 1:5 (Paulsen & Naude, 2002); farm implements can be easily used with these
gradients (Naude, 2002).
4.1.9.
Suitable Water Management Structures
The Ermelo Mines’ discard dump covers 60Ha of land (Viljoen, 2002).
A
considerable amount of water falls on the dump during a rainstorm; if this is put in
perspective: it means that for every 25mm of rain, 15000 tons of water falls on the dump
(Viljoen, 2002). A certain percentage of the water is absorbed by the soil and later released
by evaporation and evapo-transpiration (Paulsen & Naude, 2002). The remaining water
finds its way through the soils (and discard material) to infiltrate the dump and end up as
ground water (Paulsen & Naude, 2002).
It is important that runoff from rainwater is
accommodated in the drainage system of the dump (Paulsen & Naude, 2002). The design
criterion that was used for the drains and contours in the Ermelo case was to cater for a
storm event equal to the calculated regional maximum flood (Naude, 2002). Drain design on
dumps can be problematic and require expert knowledge and design skills (South Africa,
2001a).
Historically, mistakes have been made with drain designs in the mining industry in
general (Cochrane, 2002).
Spiral contour drains were designed for the Ermelo Mines
discard dump in order to minimise erosion. Spiral contour drains are considered unique to
Ingwe and were previously implemented with great success on two other Ingwe mines
(Paulsen & Naude, 2002). Spiral contour drains are easy to construct, and they reduce the
margin for error that can occur during the construction phase (U.S. Bureau of Mines, 2002);
they eliminate the need for specialised inlet structures and expensive runoff chutes (Naude,
2002). Ermelo spiral contour starts on top of the discard dump and spirals down the slopes
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of the dump until it reaches the natural ground elevation at the toe of the dump (Paulsen &
Naude, 2002).
There are two main spiral contours on the dump with various smaller and shorter
contours (Viljoen, 2002). The smaller drains followed the same design principles, but did not
start on top of the dump (Viljoen, 2002). Approximately 70% of the runoff water drains to the
north-west and the remainder to the south-east (Paulsen & Naude, 2002). Once the water
reaches the natural ground level, at the toe line of the dump, it is channelled through
armourflex drains into the natural streams (Paulsen & Naude, 2002). The water run-off if not
properly channelled and treated may cause serious health hazards to people and the water
eco-system, therefore, the water was treated and then channelled through the armourflex
into the stream (Naude, 2002).
In addition to the implemented processes for closure it is suggested that the
following options identified in South Africa, (2001b) would have facilitated the reclamation;
preventing and removing water from contact with toxic materials and treating water drainage
to reduce toxic content to be released to water courses. The two natural, watercourses on
the north-western and south-eastern sides, run through a set of evaporation dams, which
also capture other potentially, affected water (Paulsen & Naude, 2002). The evaporation
dams are designed to spill only in high rainfall conditions, when there is abundance of clean
water in the natural streams, providing sufficient water for dilution purposes (Laurence,
2001). Water should be properly channelled to avoid the release of contaminated water
from discard dumps to watercourses.
4.1.10. Minimization of Water Ingress into the Discard Material and Monitoring of
Pollution Plume from the Discard Dump to the Natural Watercourse
Ingress of water into the discard material of a discard dump must be minimised to
limit the effects of pollution (Paulsen & Naude, 2002). Water that infiltrates into the discard
material starts of as clean rainwater and gets contaminated the further it seeps through the
discard material (Laurence, 2001). When water on the discard dumps eventually decants at
the lowest lying toe line areas, it is normally heavily polluted (Paulsen & Naude, 2002).
Water pollution from discard dumps should be prevented as far as possible (South Africa,
2001b). One of the concepts applied universally is by way of cladding (U.S. Bureau of
Mines, 2002); topsoil is used for this purpose.
The Water Research Commission, through tests, indicated that infiltration of both
oxygen and water is effectively limited if the soil layer thickness is in excess of 500mm
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(Naude, 2002). At Ermelo it was, therefore, decided to clad the dump with a layer of 500mm
of topsoil (Naude, 2002). The topsoil used to clad the Ermelo dump contributed to the longterm sustainability of the dump, both as growth medium and as an impervious layer to
prevent infiltration (Paulsen & Naude, 2002). Although the topsoil acts as an impervious
layer to prevent water entering the discard material, it also acts as a “store and release”
mechanism for rainwater, making water available to the plants (Paulsen & Naude, 2002). A
farm adjacent to the dump was purchased to find suitable soil for the dump (Viljoen, 2002).
If swelling clay minerals are present in high proportions in a dump, uncontrolled
infiltration through cracks in the clay is possible, which will limit growth by limiting release of
water to the plants in dry periods (Viljoen, 2002). The soil used on the Ermelo dump was of
near ideal clay content (Viljoen, 2002). Boreholes were constructed at different positions
from the discard dump to serve as monitoring points (Paulsen & Naude, 2002). Samples
were taken regularly, the soil physical and chemical properties were analysed, and the
results recorded (Naude, 2002). By building boreholes as monitoring points, Ermelo Mine
Services were acting in accordance with the international Standards and criteria to keep acid
or other toxic drainage from entering the underground water (Paulsen & Naude, 2002).
4.1.10.1.
Topsoil and Vegetation Requirements
The volume of topsoil placed on the discard dump and the associated reclamation
areas was approximately 500 000m3 (Paulsen & Naude, 2002). The bottom layers of the soil
in the area of the discard dump were more of a gravel type of soil (Paulsen & Naude, 2002).
The gravel soil, if mixed with the fertile top layers of the soil, has specific benefits that
complemented the overall benefits on the soil used to cover the discard dump (Viljoen,
2002). The gravel type of material contains a relatively high concentration of trace elements
that boost plant fertility, while the coarse particles in the soil mixture also limit raindrop
erosion (Viljoen, 2002).
The selection of the grass species plays an important part in the vegetation process
(Anon, 1997a). In Ermelo mines, the species selection approach was based on the following
principles (Naude, 2002):
• The initial cover of grass had to be quick-growing to stabilise the soil against
erosion, particularly when the soils were vulnerable to be washed away during
the first summer rains; Eragrostis teff (known as tef) grows fast and was used.
• The soil of the dump had to be held together with creeper grasses. Horizontal
growth, as with creepers, covers the area like a lawn if managed correctly. In
this regard, the following creepers were introduced in the seed mix: Cynodon
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dactylon (known as kweek) and Chloris gayana (known as Rhodes grass). On
the contours, Pennisetinum clandestinum (known as Kikuyu) was introduced to
offer more resistance to erosion.
• The initial management strategy was to graze the area after the second growing
season. Strong growers, which are palatable for cattle and which can be cut and
baled, were used for “high production pastures”; the species chosen included
Digitaria eriantha (known as Smutsfinger) and Chloris gayana. During the first
season the grass could be cut and baled; the area was later utilised for livestock
grazing.
• At a later stage it is intended to introduce species of grass that are endemic to
the area. The purpose is to slowly change the appearance of the dump to that of
the surrounding natural environment.
Should the dump not be managed
intensively, it will revert to natural veld conditions (Naude, 2002). Grasses for
this stage are Melinis repens (known as “fluweel grass”) and Themeda triandra
(known as Redgrass or “Rooigras”) (Naude, 2002). The Themeda triandra is a
highly palatable natural grass good for grazing (Naude, 2002).
The Ermelo Mine Services have apparently complied with the international
standards by establishing a diverse and permanent vegetation cover capable of selfregeneration and at least equal in extent of cover to the natural vegetation of the
surrounding areas on reclaimed areas and all other lands affected by mining.
4.1.10.2.
Topsoil Borrow Pit Design
The borrow pits for stripping the topsoil were designed to be free draining and,
when rehabilitated, leaving a landscape hardly recognisable as an area previously used as a
borrow pit (Viljoen, 2002).
The sides or boundaries of the borrow pit were designed
according to the same principles applied to the discard dump, namely to have slopes not
exceeding 1:5 (Viljoen, 2002). Excavation process were done to preserve the fertility of the
soil in the borrow pit to ensure that the area can be used in the future (Paulsen & Naude,
2002). Strips of soil were left behind while the rest was removed and placed on areas where
it was needed (Viljoen, 2002). The strips of soil that were left behind were then spread
across the entire borrow pit area (Viljoen, 2002). By applying the above method, the soil
containing organic matter and a portion of the natural seedbed was distributed across the
borrow area (Naude, 2002). The resultant was that the topography was lowered to fit in with
the landscape and had a limited influence on the soil fertility (Naude, 2002). Borrow pit
areas were later seeded at the end of the vegetation project (Naude, 2002).
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4.2.
AFTERCARE OF THE RECLAIMED AREAS
Aftercare on the Ermelo Mines Services reclamation areas required that the
following issues were addressed (Naude, 2002):
• aftercare management,
• cutting and baling of grass,
• weed control,
• erosion control,
• re-establishing of denuded areas with a suitable grass cover,
• grazing the area,
• fertilising and topdressing,
• establishing of fire breaks, and
• evaluation and auditing the re-vegetation process.
4.3.
RECLAMATION OF THE WATER SUPPLY
Negative impacts from the underground mining activities are said to have affected
farmers in the area of the Ermelo Coal Mine (Paulsen & Naude, 2002).
As coal was
extracted, the natural tendency was that the rock strata above the mined areas cracked and
drained some of the water into the mine at a faster rate than normal (Chamber of Mines,
1996). The cracks apparently caused some boreholes to dry up as the water table dropped
(Chamber of Mines, 1999). A further complication was that the subsidence of the surface
topography resulted when remaining underground pillars collapsed (Viljoen, 2002). Where
the subsidence reached the surface above the mine, the land was apparently impacted on;
in a cultivated land area, it caused drainage problems and ponding (Naude, 2002).
During the life of the mine, some farmers experienced impacts on their water supply
from boreholes (Paulsen & Naude, 2002). The mine then provided water to farmers by
carting water to the affected areas, which became a full time job (Viljoen, 2002). Ermelo
Mines Services committed itself to the successful solution of the problem that satisfied both
the mine and the affected farmers. In order to solve the problem, the mine contracted
specialists in the field of geohydrology and agriculture (Paulsen & Naude, 2002). Amongst
others, a specialist in the agricultural field, a government related agricultural institute and the
Ingwe Rock Engineering Department, provided valuable inputs for solutions to the problem
(Paulsen & Naude, 2002).
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Meetings were set up between the mine, farmers, and the consulted specialists
(Naude, 2002). A framework for solving the encountered problems was agreed upon. The
meeting involved the following steps (Paulsen & Naude, 2002):
• documenting case histories relating to the problem;
• obtaining the technical details of the mining activities, the boreholes, the farming
activities and other relevant environmental related issues;
• quantifying the impacts up to then and estimating future potential impacts; and
• reaching an agreement on settlements or finding solutions to the problem.
The Ermelo Mine Services acted in line with the international reclamation standards
by involving public participation in order to solve water problems and hydrologic balance at
the offsite mine areas through water carting.
4.4.
THE ENVIRONMENTAL MANAGEMENT PROGRAMME REPORT – CLOSURE PROCESS
The final Environmental Management Programme assessment report forms part of
the standard practice when applying for the granting of a Closure Certificate in instances
where a mine ceases to operate (South Africa, 2002). The focal point of this section will be
the Ermelo Mine Services’ closure plan.
Reclamation and closure of a mine are intertwined; one cannot happen without the
other (Chamber of Mines 1996).
The closure plan for Ermelo focuses on sustainability
(Viljoen, 2002). Examples of some sustainability indicators are (Viljoen, 2002):
• Aftercare costs for the discard dump (all rehabilitated areas) must show a decline
over time. Eventually, there must be no expenditure to support the rehabilitated
areas.
• Trend lines for water quality samples, taken at strategic positions agreed with the
State must show a definite improvement over time. Final values for water quality
for water released into public streams must meet the agreed standards. An
important issue here is that, if closure is applied for before the final state of
equilibrium is reached, the water qualities as predicted by the consultants must
be in line with field measurements.
If the actual water qualities are in
accordance with the predicted water qualities, it boosts the confidence levels and
will give the State more reason to grant closure.
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At the time of writing this report, the Environmental Management Programme
Performance Assessment Report (EMPR) was in its final stages before being presented to
the State for approval (Viljoen, 2002).
4.5.
RECLAMATION CHALLENGES FOR MINING INDUSTRY IN REACHING MINE CLOSURE
Reclamation challenges based on the past experiences in mining will be outlined
and future anticipated reclamation challenges in South Africa would be discussed below.
4.5.1.
Key Issues from the Past
Mine closure and its reclamation are interdependent because one cannot happen
without the other, therefore both should be given equal attention (South Africa, 2001a). In
South Africa, ground and surface water pollution have provided the most common problems
(van Zyl, 1999). Several South African mines have been awarded closure certificates and
developed serious environmental impacts thereafter through water pollution (Naude, 2002).
In South Africa, new strategies need to be developed and implemented by the
mining industry, the State, land owners, NGO’s, and communities to work together to solve
the problems associated reclamation challenges to attain mine closure (Cochrane, 2002).
Much has been learnt about acid mine drainage (AMD) and that some of the AMD decants
should be treated to meet legal standards and societal expectations (South Africa, 2001a).
A major stumbling block to mine closure is to determine the legal and regulatory
requirements (van Zyl, 1999).
What makes the above more difficult is that the various
authorities have differing requirements and expectations that are exacerbated by personnel
changes (Naude, 2002). It appears that the state is not willing to make clear-cut decisions
when it comes to mine closure because it fears that the measures implemented will not
withstand the test of time and become a cost to the taxpayer (Viljoen, 2002). For example,
is rehabilitation conducted effectively to ensure the change in landuse from mining to
agriculture, or any other landuse (Viljoen, 2002)? The other problem is secondary mining by
individuals who re-mine mine dumps that have just been rehabilitated (Viljoen, 2002).
4.5.2.
Future Closure Challenges
The greatest challenge the mining industry face is to get a closure certificate when
the mine closure plans approved by the state and other stakeholders have been
implemented (South Africa, 2001b). In South Africa, while surface reclamation is preferred,
underground mines or parts of the mines tend to be neglected (Cochrane, 2002).
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Surface (and visible) components of Ermelo Mines were rehabilitated, but little was
done about the underground workings. International regulations require mine holders to
rehabilitate the surface and underground working in order to avoid subsidence (U.S. Bureau
of Mines, 2002). South Africa needs clear guidelines that will provide direction for effective
and efficient mine reclamation and closure (Naude, 2002). Many reclamation and closure
plans have been caught up in a web of uncertainty and by the lack of decision-making
criteria (Voogd, 2001). The cost of clear decision process to both industry and government
is not appreciated and has not been quantified (Naude, 2002). When it takes longer than
ten years to get a closure certificate, there is a clear indication of something wrong and
people have to develop innovative procedures to break the drought of closure certificates so
that people can move on and invest their time and resources on developments that can
deliver jobs, returns and deliver people from poverty (Voogd, 2001).
Most of the past challenges were viewed from a technical mining and environmental
perspective (Naude, 2002). A new era, of sustainable mine reclamation and mine closures
arrived when South Africa hosted the World Summit on Sustainable Development in
Johannesburg (Cochrane, 2002). From the Summit and other developments, notably the
new Minerals Bill and the Mining Charter, new approaches to mine reclamation and mine
closure were suggested (Paulsen & Naude, 2002). The best way to achieve the required
mine closure results would be to develop the right “reclamation/closure habit” (Walde, 2002).
The right “closure habit” should rest on four cornerstones, namely (Walde, 2002):
• knowledge,
• skills and ability,
• financial capability, and
• a will to do the right thing.
Knowledge refers to how to assess performance, understanding the relationship
between cause and effect and being able to implement known mitigation measures that will
deliver a known result (Walde, 2002). The skills existing in South Africa to apply established
knowledge are limited.
Therefore, some action is required in order to raise the
implementation skills levels.
Most of the mines in South Africa can afford to close their mines sustainably,
because adequate financial provision for closure requirements has now been put in place for
existing mines; rehabilitation funds are apportioned to cover mine closure costs (South
Africa, 2001b).
For effective mine closure, it is essential that appropriate checks and
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balances are put in place (Walde, 2002). Even in a self-regulatory environment, one needs
effective sanction against those who do not comply with the requirements on a voluntary
basis (Viljoen, 2002). In South Africa, the government and the mining industry must develop
a plan of action that will consider at least the following factors (Walde, 2002):
• A clear government policy developed in close collaboration with the mining
industry, which addresses the key environmental issues.
• The issues surrounding co-ordination and co-governance that hamper
implementation of the current system should be resolved at a government level.
• A systematic process for closure procedures should be developed. In this regard,
reliance should be placed on best practice guidelines such as those already
developed in Australia and other parts of the world.
• Regulations that provide appropriate checks and balances should be put in
place.
It is important that the perception that mine closure represents anything more than
relief from specific requirements of the Minerals and Health Act should be corrected (South
Africa, 2001a).
4.6.
CURRENT DILEMMA
The current legislation applicable to mine closure in South Africa has either
changed or is in the process of being changed (Naude, 2002). Policies and guidelines are,
however, still under revision or waiting approval of legislation to be updated (South Africa,
2001a). The major problem is that the success of the applicant for mine closure is thus
judged in terms of the compliance with the requirements of the latest applicable legislation
but the applicant has no written guidance on the method of complying with the new
legislation in the form of both on policy and technical levels (Schab & Postma, 20002).
The mining industry as well as the department of Water Affairs and Forestry
(DWAF) also experiences the dilemma of lack of clear guidance procedures (Voogd, 2001).
Mines are constantly confronted with a lack of clear direction and guidance for the
application of technical requirements.
Proposed changes in legislation influence the
requirements for improved water resource management and inconsistency in application of
legislation, amongst others (Schab & Postma, 2002). The DWAF is confronted with a lack of
technical information to support decision making, a continued risk of accepting unreasonable
liability, uncertainty regarding long term sustainability, lack of capacity, and various other
problems influencing the assistance to the industry towards mine closure objectives (Voogd,
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2001). It is clear that the current situation is prone to lead to confusion, frustration and
conflict both within the government departments and the mining industry (Walde, 2002).
The costly exercise to rehabilitate abandoned mines or remediation of pollution due
to abandoned mining activities encountered by the DWAF does not reflect the current policy
statements with regards to mine closure (Schab & Postma, 2002). It is, thus, clear that the
way forward for rehabilitation and mine closure can not only be lodged in a “vision
statement” but what is needed is practical way forward addressing the requirements of both
the mining industry and still achieving the mandate of the DWAF by the development of
clear, feasible and written guidelines on achieving a sustainable long-term solution (Schab &
Postma, 2002).
4.7.
THE WAY FORWARD
Currently, various new legislation, policies, and strategies are under revision or in
development (South Africa, 2001b).
Probably the biggest legislative influence on mine
rehabilitation and closure is the current Minerals and Petroleum Resources Development Act
(Schab & Postma, 2002).
Furthermore, the development of the Mining Environmental
Management Series (MEM) of guidelines is perceived as a positive incentive by the DME
(Walde, 2002). The process of revising the Aide-Me'moire guideline and replacing it with an
Environmental
Management
Plan
(for
reconnaissance
and
prospecting)
and
an
Environmental Management Program (for mining) is a clear indication that the DME needs
more guidance on mining technical requirements (South Africa, 2002).
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CHAPTER 5:
RECOMMENDATIONS
The central focus of this chapter is the recommendations of mitigation measures in
order to guarantee successful reclamation of derelict mines. As previously indicated, mining
industry by its very nature generates significant pollutants that differ in type and volume.
Therefore, it is imperative that the long-term environmental protection and management
must be given priority over short-term economic gain (Giammar, 2002). The concern is
underpinned by the legacy of past mining in many parts of the world. Recognition of the
need for environmental assessment is also emphasized or contained in the Rio Declaration
on Environment and Development, principle 17 states “Environmental impact assessment,
as a national instrument, shall be undertaken for any proposed activities that are likely to
have a significant adverse impact on the environment and are subject to a decision of a
competent national authority” (Attewell, 1993:65).
It is important to realize that the consumers pay for the amelioration of pollution,
whether it is generated by the mining industry or by the consumers or by any other activities
(Baxter & Wicomb, 2000).
It has to be recognized that environmental improvement is
justified on a quality of life and resources basis (Laurence, 2001). Continuing environmental
damage arising from polluted waters and dispersal of contaminated solid waste is a feature
of old mines in South Africa, North America, Australia and Europe (Chamber of Mines,
1999). It is, therefore, becoming standard practice for reclamation measures to be
considered as an integral part of mine planning and operations, even to the extent that
financial provisions are made during the operational life of mine to effect reclamation
measures upon closure (South Africa, 2001a). The higher environmental profile attached to
modern mining is linked not only to social acceptability but also to legal requirements in
many countries (Harrison & Hester, 1994).
5.1.
ERMELO MINES SERVICES
The recommendations in this section should be viewed as a complimentary process
to supplement on Ermelo Mine Services’ reclamation processes in order to achieve
reclamation objectives as per the mining guidelines in South Africa. The recommendations
below are the stepping-stones that are recommended, which would have improved Ermelo
Mines Services’ reclamation processes (Chamber of Mines, 1999):
• All disturbed areas are restored in a timely manner to conditions that are capable
of supporting the uses they were capable of supporting before any mining or
higher or better uses.
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• The underground activities are consistent with the surface owner plans and
applicable to local landuse plans and programs.
• The local authorities and interested and affected parties are encouraged to
initiate and authorize the proposed landuse following reclamation.
• Additional drainage systems are installed at the disposal areas to prevent
leaching.
• Water runoff from the undisturbed areas is not commingled with water runoff
from the surface of the refuse pile or dump area.
• Organic material is used as mulch or is included in the topsoil to control erosion,
promote growth of vegetation or increase the moisture retention of the soil.
• There should be no permanent impoundments on the rehabilitated dump.
• Monitoring boreholes and methane release valves are serviced regularly to
control the concentration of methane and the contamination of ground water.
• The stability of disturbed areas is monitored annually to prevent unexpected
subsidence.
• Armourflex drains and rock underdrains are constructed of durable, non-acid,
non-toxic forming rock (e.g. natural sand and gravel, sandstone, limestone or
other durable rock) that does not slake in water or degrade to soil materials and
which is free from coal, clay or other non-durable material.
• Perforated pipe underdrains are corrosion resistant and have characteristics
consistent with the long-term life of the fill (refuse pile).
• Where spontaneous combustion occurs in the future, (e.g. burning coal waste),
waste should not be removed from the permitted disposal area without a removal
plan.
5.2.
OTHER RECOMMENDED MINING DERELICT LAND SOLUTIONS
Because derelict land includes a wide variety of materials, the methods of
reclamation have to be tailored to specific problems of each material (Bradshaw, 1997).
5.2.1.
Top Soil Conservation
The most obvious solution to the problem of derelict land is that “prevention is better
than cure” (Bradshaw, 1987). If a area is to be disturbed by surface mining or tipping, the
fertile surface layers of soil, the top soil (30cm) and sub-soil (60cm) have to removed
separately and stored, and then replaced later where disturbance occurred, so that the
original soil is restored immediately (Attewell, 1993). It is easy to do in a progressive, strip
mining operation where the extraction operation moves quickly over the area taking a
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relatively thin layer of material, such as coal and sand lying under overburden (Naude,
2002). To expose the initial working face, the topsoil, subsoil and overburden must be
dumped (U.S. Bureau of Mines, 2002). Thereafter the overburden can be removed and
replaced when extraction is finished, followed by subsoil and finally topsoil, with sequent
savings in handling, in a continuous, progressive operation (Bradshaw, 1987). Topsoil loses
should be minimal and topsoil care should taken for future soil use (Anon, 1997a). In nearly
all modern progressive operations, topsoil replacement will soon be standard practice and
should be required by authorities permitting mining developments (Great Basin Mine Watch,
2002). However, in modern large-scale strip-mining it may be difficult and expensive to
transfer the topsoil across the working face to the replaced overburden (Hoffman, 1997). It is
possible that the overburden with a little improvement can form a better soil than the
previous topsoil (Cochrane, 2002).
5.2.2.
Top Soil Application
It may be possible to obtain good soil from a site that is being developed for other
purposes and spread it over an area of derelict land from which the topsoil has been lost
(Bradshaw, 1987). The process provides in one operation a fully developed soil, of good
structure and texture containing an adequate store of nutrients (Anon, 1998b). The organic
matter and nutrients constitute a buffer against any extremes of toxicity or other adverse
factors that may be present in the derelict land material, and the good structure ensures
satisfactory water retention even if the waste material underneath has a poor water retaining
capacity (Toy & Griffith, 2001). As a result, establishment and growth of plants when topsoil
is used as covering material are excellent (Toy & Griffith, 2001); planting can be spread out
over a long period (Krige, 1993a). If the correct procedures are followed, growth after the
period of establishment should be good, since the soil has a store of nutrients, which are
released slowly (Bradshaw, 1987); aftercare, in the form of fertilizer additions, may not be
necessary (Bradshaw, 1987). There is usually no need to know what is wrong with the
material making up the derelict land, since the topsoil provides a totally new environment in
which the plants can grow (Toy & Griffith, 2001). As a result, topsoil is an obvious and widely
recommended solution (Chamber of Mines, 1999); it is one that appeals to many people,
especially those who believe erroneously that topsoil has a unique quality that cannot be
reproduced (Schab & Postma, 2002).
The question is: why is the above not the universal solution (Schab & Postma,
2002)? A simple answer is cost and availability (Cook, 1990). To be effective, the layer of
topsoil must at least be 10cm thick (Baxter & Wicomb, 2000). That will be sufficient only to
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RECOMMENDATIONS
provide a good seedbed and a moderate store of nutrients for subsequent growth (Cook,
1990). Plants will have to be able to root into the underlying material and obtain much of
their water and nutrient from it (Alcoa World Alumina Australia, 2001). To be totally sufficient,
a grass sward will need at least 25cm (Shankar & Kapoor, 1993); trees will need far more.
Loading, handling and spreading more quantities of soil, even with modern machinery, at
present cost considerably more than $500 (± R3500) per ha and will cost much more when
the soil has to be carried more than one or two kilometres (Bradshaw, 1987). Where such
costs cannot be met out of immediate income in an active industry and the land is therefore
truly derelict, they may be prohibitive (Elliot et al., 1996). Even if finance is provided, people
will ask whether it is appropriate to spend money in that manner, when it could be put to
other aspects of the restoration such as the establishment of playgrounds, or even building
houses or schools (Baxter & Wicomb, 2000). There are many situations, such as areas
where there is a large amount of derelict land, where even if the money is available, the
topsoil is not (Baxter & Wicomb, 2000); for example, in many mined areas around
Johannesburg, the use of topsoil would mean that other areas would have to be made
derelict in order to acquire the topsoil (Voogd, 2001). The same is true in remote country
districts and national parks where there is no construction work that would provide topsoil
(Voogd, 2001). However, where a large heap of waste is being reduced in height and
spread over a larger area than it originally occupied it is often practical to remove the topsoil
from the areas where the heap will be and then spread it back thinly over the whole heap
(Bradshaw, 1997).
5.2.3.
Re-vegetation
The objectives of vegetation establishment are: long-term stability of the land
surface which ensures that there is no surface erosion by water or wind, reduction of
leaching, lessening the amounts of potentially toxic elements released into local
watercourses and to ground waters, development of a related landscape or ecosystem in
harmony with the surrounding environment, and positive value in an aesthetic, productivity,
or nature conservation context (Street, 1986). The approaches to re-vegetation can be
described in terms of two different basic philosophies: (1) adaptive, and (2) agricultural
(Harrison & Hester, 1994).
5.2.3.1. The Adaptive Approach:
The adaptive approach emphasizes the selection of the most suitable species, subspecies, cultivars and ecotypes to meet the rigors of the extreme conditions. It is not
necessarily true that the mine wastes may be improved using amendments to achieve
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optimum establishment and long-term growth (Harrison & Hester, 1994). The approach is
simple but is constrained by the availability of suitable indigenous species in some areas.
5.2.3.2. The Agricultural and Forestry Approach:
Agriculture and forestry has been used directly on less toxic media such as iron
stone, coal and bauxite wastes and on wastes covered over with deep layers of soil or
overburden (Harrison & Hester, 1994). Agricultural crops or livestock or woodland and scrub
species are established using conventional or specialized techniques (Giammar, 1997). In
practice, it is the combinations of the above approaches based on site-specific
considerations that produce the final re-vegetation strategy (Harrison & Hester, 1994). An
extension to the above philosophies and their combination, is the “ecological approach”
which places emphasis on the importance of establishing biological processes such as
nitrogen fixation, decomposition, nutrient cycling and retention and important biotic
interactions (e.g. pollination) (Harrison & Hester, 1994). The above are some of the issues
that indicate proper ecosystem functioning, which is as important as the careful selection of
plant species in providing the primary vegetation structure (Harrison & Hester, 1994).
Whether the reclamation goals are to restore the original natural ecosystem or to produce an
acceptable alternative, ecological principles should underlie all good reclamation schemes
(Schab & Postma, 2002).
5.3.
RE-VEGETATION TECHNIQUES AND LANDUSE
This section deals with the different re-vegetation techniques applicable to specific
landuse.
Various techniques have been developed to suit particular waste problems,
ranging from cultivation with conventional agricultural machinery followed by fertilization and
direct seeding for innocuous wastes, to specialist procedures such as placement of a barrier
layer or deep coverings of non-toxic materials for very toxic sites (Anon, 1998a). However,
many factors have to be considered in the choice of plant materials, and their method of
establishment, in particular the nature of the spoil, the prevailing climate and the eventual
landuse (Rainbow, 1987). Identification of the problems preventing plant growth coupled with
careful selection of species and appropriate long-term management is the basis of
successful re-vegetation (Rainbow, 1987). Details of each re-vegetation technique
(presented by Rainbow, 1987) are discussed below.
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5.3.1.
Direct Seeding
5.3.1.1. Normal Species
Unfortunately, straightforward direct seeding with conventional species and
fertilizers is often unsuccessful as a re-vegetation measure, at least an older mine tailings,
because of the toxic residual levels of metals that are often associated with high acidity
levels (Juwarkar & Malhorta, 1991). Under these circumstances grass and other seedlings
persist for only a few weeks (Juwarkar & Malhorta, 1991); however, the procedure remains
an attractive option in principle, because direct seeding is cheaper than any other method
(Baxter & Wicomb, 2000). In situations where the waste contains little residual metal, or
where the metal is not available to plants, normal species can be established directly with
the assistance of fertilizer (Bradshaw, 1997). The long-term growth of vegetation depends on
an adequate supply of nitrogen, legumes such as white cover or bird-foot trefoil (Lotus
corniculatus) are an important component of the seed mixture, since they have the capacity
to supply nitrogen B fixation of atmospheric sources (Parrota & Knowles, 2000). Trees with
rapid growth such as Black Locust (Robinia pseudoacacia) can be effective in visual screen
plantations for tailings ponds, waste heaps and mine buildings (Toy & Griffith, 2001).
5.3.1.2. Competition
Species that grow favourably with other components of a seed mixture should be
chosen; for example, establishment of young trees in lush ground cover vegetation may be
adversely affected by competition (Robbins, 1996).
5.3.1.3. Availability
Species that are available commercially should be selected for planting (Rainbow,
1987).
If companies can foresee requirements and order from reputable commercial
nurseries giving at least a year’s notice, unusual requirements can often be met (Gaunt &
Bliss, 1993). For full reinstatement of a diverse native flora, a company should consider
establishing its own nursery facilities (Rainbow, 1987).
5.4.
SURFACE IMPROVEMENT AND COVERING SYSTEMS
In terms of lapsing, cancellation and cessation of the mining operations the surface
area should be improved and properly covered to provide a base for plant growth (South
Africa, 2002). The method of selection for improving plant growth conditions should be
based on (International Committee for Coal Research, 2000):
• alleviating toxicity and acidity,
• augmenting supplies of essential plant nutrients,
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RECOMMENDATIONS
• improving the physical properties, and
• achieving maximum benefit from the materials available on site or nearby.
Fertilizer application to tailings is always necessary and use of organic matter is
advisable if it can be obtain locally (Griffith et al., 1996). There should be correction of
acidity or alkalinity, because a wider range of plants can then be established, while toxicity is
alleviated and the availability of nutrients for plants is increased (Giammar, 1997). The
principle behind the addition of materials to tailings or covering of a surface is to dilute or
avoid toxicity problems rather than counter them by direct seeding of tolerant populations
(Marcus, 1997). The covering of mine waste to isolate it from the establishing vegetation is
a common approach to reclamation and can succeed if a suitable depth of material can be
introduced into which the chosen vegetation can root and develop satisfactorily (Moffat,
2001). Usually the cover material is topsoil, subsoil, or overburden (Chamber of Mines,
1999). It is rarely feasible for economic reasons, to provide depths of cover greater than 300
mm, and in the case of some modern tailings the load bearing capacity precludes the use of
most forms of civil engineering equipment required to apply the cover (U.S. Bureau of Mines,
2002). On wastes of low to medium toxicity, covering layers can provide a cheap method of
improvement, whilst very toxic materials require barrier layers or isolating materials between
the wastes and growing medium to reduce upward movement of metals. In some cases,
especially where toxicity is marginal, simple dilution of the waste with innocuous material
may suffice (Nichols & Gardner, 1998).
5.5.
DILUTION
Dilution is one of the most vital approaches used for preparation of re-vegetation to
improve the soil capability as a medium for plant growth. This next section outlines the
dilution method.
The simplest approach to re-vegetation using amendments is to incorporate
suitable material into the mine waste surface on the principle of diluting the influence of the
residual metal values below phytotoxic thresholds (Merryweather, 1993). Organic matter in
particular is used in dilution, because it has important beneficial effects both on the physical
characteristics and the nutrient status of mine wastes (Nichols & Gardner, 1998). Organic
material increases the water and nutrient holding capacity, improves surface stability,
aeration and water penetration by alteration of the soil structure, whilst decreasing surface
run-off and improving the seed bed (Juwarkar et al., 1993). In addition, mine discard can be
temporarily complex by organic material that binds them in an innocuous form until natural
decay of the organic matrix causes remobilization (Juwarkar et al., 1993). Amendments
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RECOMMENDATIONS
such as farmyard or poultry manure or sewage sludge are usually incorporated into the
surface to 150 mm depth by dicing (Parrota & Knowles, 2000). The aim is to achieve about
3 – 6% organic matter content, which is a level expected in normal soils (Parrota & Knowles,
2000). Modern high analysis, compound fertilizers are used in association with the dilution,
and cover approaches to re-vegetation (Anon, 1998b). Compound fertilizers are formulated
from compatible chemicals and are easy and clean to handle whilst occupying less storage
and transport space than the more bulky organic sources of nutrients (Anon, 1998b).
Compound fertilizers are available to cover most needs (e.g. NPK fertilizer 17.17.17
which supplies 17% N, 17% P2O5 and 17% K2O by weight) (Cook, 1990). Slow release
commercial fertilizers, which release their nutrients in a time graded pattern over months and
even years, are more expensive but can produce good results and reduce labour costs
(Cook, 1990). Coal, lead–zinc mine tailings in the Peak District National Park in the UK,
represent a successful example of the dilution approach to reclamation (United Kingdom,
1989). Another recommended method is hydro-seeding technique, which could be used to
residual levels mine discard that is not toxic in order to establish a commercial grass legume
seed mix, with the use of air dried, digested sewage sludge, and phosphate fertilizer applied
directly to the dewatered tailings surface (Fox, 1984). In many cases, the establishment of
grassland together with subsequent planting of trees and shrubs has proved to be very
successful and also led to colonization by wildlife (Coetzee, 1998). Surface leaching using
overhead sprinkler system as the basis for dilution of acidity has been used successfully
along the Witwatersrand near Johannesburg for controlling acid-sulphate levels in the
surface layers of gold mine tailings (Coetzee, 1998). Regular mist-spraying regulates the
acidity in surface layers at a sufficiently low level to permit the establishment of grasses and
legumes after treatment of tailings with lime and fertilizer (Chamber of Mines, 1996).
5.6.
SIMPLE COVERINGS
Soil or surface cover has been extensively used in many areas for re-vegetation
schemes to avoid toxicity and to improve the texture and stability of waste surfaces so that
vegetation can be established (Gardner et al., 1991). The simple covering approach has
worked well in many areas but failures have also resulted mainly because of (Gardner et al.,
1991):
• the lack of penetration of roots into the underlying material leading to poor
binding at the soil/waste interface;
• contamination of the covering through upward migration and accumulation of
toxic metals, salts and acidity; and
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RECOMMENDATIONS
• penetration of plant roots into toxic material beneath, with subsequent regression
of the vegetation.
Experience suggests that the minimum depth of such surface coverings should be
300 mm; any thing less than that could lead to erosion of the coverings (Bradshaw, 1987).
5.7.
BARRIER OR ISOLATING LAYERS
Barriers or isolating layers are used in mining of coal minerals and if properly
implemented, they prevent self-heating or spontaneous combustion. Details of barrier or
isolating layer method are extensively outlined below.
The use of barrier layers, although less common than the simpler methods,
because of higher costs, are currently popular for wastes that present a particular hazard to
local communities through toxic pollution, and also where there is a pressing need to
develop a specific landuse (e.g. sports fields, grazing land), or where vegetative stabilization
cannot otherwise be considered due to extremes of toxicity and acidity (Berger, 1990). If
simple covering layers such as soil are used on toxic waste, then even with deep layers
(>300mm) upward migration of contaminants may in time cause regression of vegetation
(Cochrane, 2002). In the above cases, it is necessary to use barrier layers of material
designed to inhibit the upward movement of solutes (Berger, 1990). The main requirement
is that the barrier layer should disrupt the capillary water columns established within the
waste (Alcoa World Australia, 2001). Therefore, the layer should be at least 300mm deep,
and should consist of a course-textured material such as screened gravel with no fines, rock
waste or coarse non-toxic mine spoil (Hoffman, 1997). The approach has been used and
proved to be successful at the copper tailings dam of the old Avoca mine in the Republic of
Ireland (Harrison & Hester, 1994). A tailings dam was subject to serious problems before
the enactment of a re-vegetation scheme (Harrison & Hester, 1994). Erosion became so
serious that direct seeding using tolerant seed presented too great a risk in view of the
relative slowness of sward establishment by this method (Harrison & Hester, 1994).
Accordingly, a two layered cover approach was adopted in which a layer of shale, 200300mm deep, was placed on the tailings surface to isolate the material and then overlaid
with a skin of 75-100mm of topsoil and subsoil to provide the supportive medium cover
vegetation (Harrison & Hester, 1994).
Following preparation, the surface was treated with conventional limestone and
fertilizers before being sown with a traditional agricultural seed mixture (Harrison & Hester,
1994).
With careful management, the results were outstanding in the first two years
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RECOMMENDATIONS
(Harrison & Hester, 1994). A crop of hay was taken from the reclaimed surface in the
summer following the year of reclamation (Harrison & Hester, 1994). The quality of the
product was such that there were no constraints upon feeding the product to livestock
(Harrison & Hester, 1994). The grass surface now supports a wide range of herbaceous
species and is now carrying complement of wild life (Harrison & Hester, 1994).
5.8.
RE-VEGETATION OF TAILINGS AND WASTE ROCK DEPOSIT
Tailings and waste rock deposits pose dangers to structures, animals and human
beings and have not all been re-vegetated to acceptable standards; hence, in this section revegetation processes for tailings and waste rock deposit will be discussed in detail (Voogd,
2001).
During the operating life of the mine, deposited tailings are normally largely covered
by the supernatant mill effluents leaving only the beaches exposed (Tacey, 1979). It is
important to minimize wind erosion that can become a serious problem where prolonged dry
seasons are encountered (Krige, 1993a). At “close out” or cessation of active operations, it
is now usual for regulations to require a permanent system for the management of tailings
and waste-rock areas so that they are not a health hazard to their human beings or animals,
nuisance is minimized and continued contamination of water courses does not occur
(Robbins, 1996). Improvement of aesthetics should be a significant objective; flat sandy
areas can be visually obstructive in wooded or mountainous terrain (Street, 1986). Tailings
contain major proportions of slimes; the eventual total “dry out” process can be very
prolonged and can be accelerated by transpiration from suitable tree plantations (Bradshaw,
1997). When tailings have adequately dried, it is possible to establish vegetation on barren
and hostile substrate using techniques that have developed rapidly over the last 10-15 years
(Bradshaw, 1997).
Control of pH by heavy liming is usually essential, followed by the
application of plant nutrients such as nitrogen and phosphorus (Baxter & Wicomb, 2000).
Grasses, and other vegetation, indigenous to an area, are often the most promising
candidates for successful re-vegetation (Baxter & Wicomb, 2000). Once a limited natural
humus cover has been established, legumes can also be incorporated (Gardner et al, 1991).
Where tailings or waste-rock is highly pyretic, re-vegetation is more difficult, due to the
generation of acid (Bradshaw, 1987). Areas can be top soiled before re-seeding but such a
procedure is usually inordinately expensive (Bradshaw, 1997).
5.9.
OPEN PIT MINING
Open pit mining is a mining operation whereby minerals are extracted from the
surface of the earth not underground. The open pit mining can be rehabilitated, depending
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RECOMMENDATIONS
on the weather and hydrology of the area; it may be possible to allow the pit to fill with water,
provided it is acceptable for recreational or fishing purposes and does not contaminate local
surface or ground water (Rainbow, 1987).
5.10.
MANAGEMENT AND AFTERCARE
Management and post mine closure aftercare involves the neutralisation of the toxic
substances and proper monitoring system of the rehabilitate lands (South Africa, 2002).
Details of management and aftercare are explained in this section. Where toxic wastes are
reclaimed, regression of a well-established sward could occur (Mining Magazine, 1995).
Regression may be due to one or more of the following (Mining Magazine, 1995):
• weathering of pyritic wastes producing acidity, which in turn alters the variability
of plant nutrients and toxic metals,
• gradual decomposition of organic amendments releasing metals previously held
in stable organic complexes,
• depletion of nutrients required for growth,
• extreme weather conditions, and
• upward migration of acidity, heavy metals, or salts into surface layers of
amendments.
It is vital that long-term management should be considered as an integral part of
any reclamation scheme and should be planned at an early stage (South Africa, 2001a).
However, the programme of long-term management depends upon the species sown and
the landuse objective (Toy & Griffith, 2001). Re-fertilization and management of a legume
component, cutting/grazing, pruning, and tying of trees, and fencing maintenance, may all be
regarded as components of a management programme for a reclamation site (van Gessel,
1993). “Rome was not built in a day”, and neither can a self-sustaining soil/plant ecosystem
be rebuilt in a single act (Laurence, 2001). The process of restoring the chemical, physical,
and biological functions of a soil takes time (Laurence, 2001); if the soil is being made from
raw waste the restoration will obviously take a very long time (Street, 1986). Even if a soil is
removed from an area and replaced almost immediately, it will take time to recover (Street,
1986). The vegetation that will have been completely destroyed will take several years to be
properly restored, unless the land is being used for annual crops (Bradshaw, 1987).
Aftercare will be problematic in all land restoration, and failure to realize that, has
been the cause of failure of very many reclamation schemes (South Africa, 2001a). Less
successful reclamation requires greatest attention. Sometimes a structure will be imperfect
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RECOMMENDATIONS
(Toy & Griffith, 2001). Imperfect structure can be restored by cultivation and the growth of
plants (Toy & Griffith, 2001); it will, however, take several years for the plants to exert their
maximum effect in breaking up soil aggregations by root growth and contributing sufficient
organic matter to lighten the material (Laurence, 2001). Until such a situation occurs, the
material will need to be treated with care, or it could be damaged (Bradshaw, 1997). A
considerable input of nutrients is always necessary (Bradshaw, 1997); this cannot be done in
one operation by providing more fertilizers than the plants can take up, so fertilizer may
leach away and be wasted (U.S. Bureau of Mines, 2002). The need is moderate input that
continues for a number of years (Walde, 1992). Yet, that is often forgotten, and after the
initial application no more is provided and this can lead to serious regression of vegetation
(Walde, 1992). If aftercare is not given all the money, effort expended on the reclamation
can be wasted (Laurence, 2001).
Like many other problems aftercare can easily be
overcome if the right steps are taken (Laurence, 2001).
5.11.
PREVENTION AND MANAGEMENT OF SELF-HEATING (FIRES) IN COAL MINING
Prevention and management of self-heating processes are outlined in this section;
the processes are only applicable to coal mining. In open cut or surface mining, large
volumes of coal and carbonaceous material are exposed to oxygen in air (U.S. Bureau of
Mines, 2002). Once exposed, the materials oxidize and liberate heat. If the heat is not
dissipated sufficiently rapidly, the temperature rises; this drives the oxidation and heat
generation process at a faster rate and if unchecked, spontaneous combustion may result
(Cochrane, 2002). The consequences of spontaneous combustion in spoil piles may be
significant (Mining Magazine, 1995). For example, open fires and smouldering combustion
can give rise to toxic fumes such as carbon monoxide, carbon dioxide, nitrogen dioxide, and
sulphur dioxide, as well as the ‘tarry’ emission products associated with incomplete coal
combustion. Further consequences arise from the danger of fire spreading to surrounding
land, the destabilization of the landform with possible subsidence, landslides, and the death
of vegetation in the vicinity of the ‘hot’ spoil (Mining Magazine, 1995). The final landform
design provides the fundamental solution in preventing self-heating in coal mine spoil.
Planning spoil dumps and the ongoing management of spoil prevents outbreaks of
spontaneous combustion (Shankar & Kapoor, 1993)
5.11.1. Best Practice Principles
The “Best Practice Principles” applied to the prevention of self-ignited fires in mines
include (Mining Magazine, 1995):
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RECOMMENDATIONS
• defining all fuel sources, ensuring the correct placement of carbonaceous
materials;
• minimizing the quantity of fuel (carbonaceous materials) going to spoil;
• reducing oxygen pathways in spoil piles;
• avoiding dumping carbonaceous or hot materials over dump batters; and
• using a “prevention is better than cure” principle.
5.11.2. Best Methods for Control
The self-heating management practices for dragline and truck-shovel operations,
truck-dumping practices that can be effective in prevention of self heating include
(Environment Australia, 1998):
• controlled placement of carbonaceous overburden and partings with inert
“pockets”;
• limiting lift height to a maximum of 15 m;
• covering all final surfaces with a 5 m layer of inert material;
• compacting final surfaces, as well as intermediate surfaces wherever possible;
• spreading out and track rolling carbonaceous material to prevent heat build-up
and oxygen ingress;
• sealing hot spoil with a cover of clay as an effective technique to control heating
(for this to succeed, careful planning, execution and commitment to seal
maintenance over many years are keys to successfully reducing soil
temperatures below acceptable levels; i.e. below 70oC); and
• grouting with inert material such as flyash as a potential alternate technique for
fire control (the objection is exclude air from the fire by filling the voids between
the spoil particles, while the advantage of this method over sealing is that it
creates an in situ barrier to air transport rather than a potentially unstable surface
barrier).
5.11.3. Guiding Management and Fire Control Principles
The US Bureau of Mines (2002) suggested the following actions as principles for
controlling fires:
• close oxygen pathways into spoil piles by surface capping or bulk void reduction;
• maintain surface seals;
• if it is not possible or practical to seal an area, spreading the material will prevent
heat build-up;
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RECOMMENDATIONS
• promote cooling by encouraging rainwater ponding; and
• early intervention is the key to prevent longer-term problems.
5.11.4. Top Soil Grafting Averts Self Heating
The above methods were applied in the Leigh Creek Coalfield mine; one of the
largest open-cut operations in Australia (Barker et al., 1995). The site covers area of 70 sq
km and has produced 2.6 to 2.8 million tones per annum of sub-bituminous hard brown coal.
Site operators controlled self-heating at Leigh Creek by compacting the final surface and by
placing freshly stripped topsoil over the compacted material (Alcoa World Alumina Australia,
2001). Observations indicate that method has prevented self-heating. The topsoil was
stripped from the areas to be mined and placed immediately over the compacted overburden
material. The “top soil grafting” method has also led to very early natural regeneration of
suitable native plants (Barker et al., 1995).
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CONCLUSION
CHAPTER 6: CONCLUSION
It can be concluded that, if the mining industry is to contribute effectively to future
sustainable development, it must develop and consistently apply sound environmental
management practices worldwide (Moffat, 2001). As a matter of urgency, mining industries
should minimize environmental impacts on and off-site during the operational mining phase.
Mining industries should extract and use resources efficiently and to encourage the efficient
processing and use of their products (The World Commission for Environment and
Development, 1987). While minerals are a non-renewable resource, in many cases they can
be efficiently reused and recycled.
Consistent with sustainable development principles,
mining operations should be intended as a transient landuse (Nichols & Gardner, 1991).
This means that after mining, the condition of the land should be reclaimed so that its value
is similar to or greater than it was before disturbance.
There are many examples in which mined land has been effectively rehabilitated to
agriculture, forestry, and nature conservation or urban or industrial landuses (Laurence,
2001). A typical example in this regard is the Ermelo Mines in South Africa. In some of
these instances the pre-mining landuse was reclaimed, while in others the landuse was
changed. Some of the changed landuses were carefully planned and implemented, while
others have evolved, sometimes after the land has undergone a lengthy period as
abandoned or waste land (Moffat, 2001). Therefore, mine reclamation (also referred as
rehabilitation) should be the process of converting mined land to its future valuable use; not
a process of burying wastes, smoothing out the landscape and applying a green mantle of
relatively valueless vegetation (Bradshaw, 1997).
The severity of the environmental problems created by mining activities and colliery
waste depends on the characteristics of the waste materials and the situation of the site
(Anon, 1998a). As mentioned above, environmental problems vary from physical visual
intrusion to land instability, pollution of run-off, land sterilization, dust blow, spontaneous
combustion, erosion on steep slopes, and improper drainage, amongst others.
The
formulation of solutions to most of the above-mentioned problems would depend on proper
analyses of the data from the initial choice of dumpsite, stockpiling location, site screening
technique, material placement method, and proper landscaping (Hoffman, 1997).
Few
would dispute that the damage done to the earth due to mining is reprehensible and should
be corrected. Certainly, as a society and as ordinary people in our own rights we must make
heroic efforts at this time in our history to protect all remaining relatively pristine resources to
prevent any further loss of land and species (Hoffman, 1997).
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CONCLUSION
Threatened and endangered species should unquestionably not have to wait any
longer for effective protection (Laurence, 2001). Rehabilitation should be a moral obligation.
It is hardly ever practical to wait for nature to take its course, and certain sorts of derelict
land have particular problems, which time and nature will not heal. On the other hand, it is
worth noting that with modern mining methods, increased environmental awareness and
regulations, and the requirement for post-mining rehabilitation have reduced the incidences
of post-closure environmental damage due to mining (South Africa, 2001a).
However,
environmental and physical problems within the earlier abandoned mine lands are, in many
cases, not yet fully developed and the problems presently visible at the older sites are likely
to increase in magnitude (Owens & Cowell, 1994). Moreover, unless action is taken to
rehabilitate sites or mitigate their impacts, they will continue to have a significant effect upon
the natural environment.
As human populations grow and the pressure for land for
habitation, agriculture and industry increases, abandoned mines will obviously represent a
continued safety risk to inhabitants and an ever more significant stumbling block to the social
and commercial developments of mining regions (Parrota & Knowles, 2000). The severance
and the extent of surface subsidence and underground fires at the Delagoa Bay mine
(Mpumalanga) site is a typical example (see Sowetan, 2001). Similar problems are evident
in other old mines in the Witbank and Ermelo areas, and in isolated instances elsewhere in
the South African coal fields (South Africa, 2001b). A large number of old mines remain in
the portfolio of current mining houses, which retain responsibility for their management and
liability for final rehabilitation and closure.
The previously mentioned concerns are
legitimate, because in a number of cases, the mining or holding companies responsible for
derelict and onerous mines have ceased to exist and in many instances the owners of the
mines cannot be traced, and the responsibility for their rehabilitation becomes the
responsibility of the State (South Africa, 2001a). The prospects for rehabilitation in the near
future of derelict mined land held by the state are very uncertain (Chamber of Mines, 1996).
The reclamation checklists used by the DME are also a cause of great concern and have
some notable shortcomings (Voogd, 2001). More often than not, the use of checklists has
been criticized; however, checklists do provide a valuable summary of expert knowledge in
an easily accessible format.
The study found that checklists, in particular the checklists used by the DME,
needed to be improved. While the DME checklist provided a relatively comprehensive list of
the baseline information required from the initial site survey, it failed to highlight the need to
interpret that information and link it to the development of the three components
(landscaping, re-vegetation, and monitoring and aftercare) of the rehabilitation programme
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CONCLUSION
(Voogd, 2001). As a result, the majority of rehabilitation reports merely describe the local
conditions without attempting to indicate how they would influence the implementation of the
rehabilitation programme (van Gessel, 1993). It appears that the majority of rehabilitation
reports drawn up in South Africa are simply approached as legal requirements and are not
documents aimed at providing achievable, long-term solutions to the disturbances caused by
mining (Schab & Postma, 2002).
Unless rehabilitation reports can function as effective
working documents, the commitment to rehabilitation will remain doubtful (Viljoen, 2002).
The reports/guidelines should be seen as legal documents that will bind the mining operator
to follow the outlined procedures.
Mining operators should be held accountable if
rehabilitation is not carried out according to the respective reports (South Africa, 2001a).
Both the operator and the authorities should undertake monitoring and after-care (Chamber
of Mines, 1999). At present, it seems that the first time the authorities see the reports is also
the last time they concern themselves with rehabilitation aspects. On the other hand, it is
worth noting that the regulations that were incorporated in the Mines and Works Act in 1980
introduced, for the first time, an environmental dimension to the work of the government
mining engineer (Voogd, 2001).
Whereas in the past, a government mining engineer had been concerned solely
with matters relating directly to the operation of mines, the person now has to consider the
safety, health and welfare of workers and the public. With the new regulations, a number of
specialized tasks such as environmental impact assessments, re-vegetation procedures, soil
analyses, aesthetic and visual impact analyses were introduced (Voogd, 2001).
Government mining engineers are to a certain extent, not suitably qualified to determine
whether a report is a good one or not. The impression is that if the report says the “right”
things (mentions climate, soils, overburden, stockpiling, re-vegetation, etc.), it is passed
(Voogd, 2001). In addition, a government mining engineer is also unlikely to be suitably
qualified to comment on the progress of a rehabilitation project; this kind of lack of
commitment often promotes the so-called “walk-away” or “mediocrity” options, which are
regrettably the reality of many mining sites in South Africa (Chamber of Mines, 1999).
Rehabilitation of mines should go hand in hand with the growth of the mines. Governments,
mining companies, and the minerals industries should in a nutshell and as a minimum
(Cochrane, 2002):
• Recognize environmental management as a high priority, notably during the
licensing process and through the development and implementation of
environmental management systems.
These should include early and
comprehensive environmental impact assessments, pollution control and other
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CONCLUSION
preventive and mitigating measures, monitoring and auditing activities, and
emergency response procedures.
• Establish environmental accountability in the mining industry and the government
at the highest management and policy-making levels.
• Encourage employees at all levels to recognize their responsibility for
environmental management, ensure adequate resources, staff, and requisite
training should be made available to implement environmental plans, ensure the
participation and dialogue with the affected community and other directly
interested parties on the environmental aspects of all phases of mining activities.
• Adopt the best practices to minimize environmental degradation, notably in the
absence of specific environmental regulations.
• Adopt environmentally sound technologies in all phases of mining activities and
increase the emphasis on the transfer of appropriate technologies which mitigate
environmental impacts, including those from small-scale mining operations.
• Seek to provide additional funds and innovative financial arrangements to
improve environmental performance of existing mining operations.
• Adopt risk analysis and risk management in the development of regulation and in
the design, operation, and decommissioning of mining activities including the
handling and disposal of hazardous mining and other wastes.
• Reinforce the infrastructure, information systems, service, training and skills in
environmental management in relation to mining activities.
• Review environmental regulations that act as unnecessary barriers to trade and
investment.
• Evaluate and adopt wherever appropriate, economic and administrative
instruments such as tax-incentive policies, and emission-rights trading to
encourage the reduction of pollutant emissions and the introduction of innovative
technology.
Notwithstanding the progress that has already been made towards finding solutions
to the problems associated with historic mined land in South Africa, a concerted and
sustained effort involving the State and the mining industry is necessary to ensure that future
developmental potential of mined land is realized (Chamber of Mines, 1999). Reclamation to
achieve environmental improvement is also essential in order to attract investors and provide
an attractive setting for development (South Africa, 2001a).
To create big holes in the
ground and mountains of waste is no longer a fashionable activity. There must be no more
of digging a hole in the ground, making money, declaring bankruptcy, running away and
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CONCLUSION
leaving the mess behind (Anon, 1998a). The time has come for us all to send a clear
message to the world that South Africa is not a haven for glory hunting prospectors and
diggers with one arm and a wheelbarrow (Voogd, 2001).
But where such insensitivity
towards the environment occurs, they (diggers) too are obliged by the law to lift a shovel for
the environment. The new rule of the mining game should be “Anyone who scratches the
surface to make money will be made to roll the rocks back” (Krige, 1993a:89). Tourists like
to visit historical mine sites with “son et lumiere” and wax figures of historical miners, but
they do not journey to valleys and mountains where real mines spew out dirt and smoke
(Walde, 1992: 33). In other countries (e.g. some in Europe), it is not even enough to return a
mined out area to an acceptable aesthetic appearance; it must be also capable of supporting
vegetation (Mining Magazine, 1995). Yes, derelict land can be transformed into something
for people to enjoy, now and in the future; It is time to win back the land.
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REFERENCES
REFERENCES
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