A case of tailing storage.pdf
Resources Policy XXXXXXXXXX–128
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esourpol
Environmentally sustainable mining: The case of tailings storage
facilities
Erica Schoenberge
Department of Geography and Environmental Engineering, The Johns Hopkins University, Baltimore, MD 21210, USA
a r t i c l e i n f o
Article history:
Received 13 November 2015
Received in revised form
24 April 2016
Accepted 25 April 2016
Available online 18 May 2016
Keywords:
Sustainability
Mining
Mine tailings
Environment and society
Environmental regulation
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a b s t r a c t
This paper addresses the question of whether mining can be done in a way that contains and remediates
environmental impacts and thereby safeguards the livelihoods of local populations. It focuses on tailings
storage facilities (TSF) as the source of most mining-related disasters. It compares outcomes at three
mines – two which ended in disaster and one notable success – to try to get at what factors are critical in
producing these outcomes. Although the design and construction of TSFs is technically challenging,the
paper concludes that the basic causes of TSF failure are political, not technical. A second purpose of this
paper is to suggest that a social scientific analysis of engineered projects needs to pay attention to the
engineering.
& 2016 Elsevier Ltd. All rights reserved.
1. Introduction
Mining is unavoidably environmentally disruptive. Huge
quantities of earth and rock are moved, some of it processed to
ecover valuable minerals, the rest discarded as waste. The mate-
ials that are left over after processing, known as tailings, are es-
timated to be produced at a rate of anywhere from five to fourteen
illion tons per year. They may include sulfide minerals that can
induce the formation of acid drainage, other processing chemicals,
and process water. Tailings can be disposed of in a variety of ways.
In the worst of the cases, they are dumped into adjacent water-
odies, whether rivers, lakes or the sea. They may be backfilled
into pits left over from underground mining. Much of the time
however, tailings are stored behind dams constructed of mine
wastes (Edraki et al., 2014; Adiansyah et al., 2015).
Environmental disruption related to mining is inevitable. En-
vironmental disaster, on the other hand, should not be, the more
so as environmental disasters often trigger social disasters. The
most critical arena for reducing the likelihood of mining-related
environmental disasters lies in the handling of tailings.
Tailings dam failures account for about three-fourths of majo
mining-related environmental disasters (MMSD, 2002a). A tailings
storage facility (TSF) can occupy several square kilometers of land
with dams that can reach in the tens of meters. Tailings dams are
not like water retention dams. They are built in stages as mining
and waste production progresses and they are built usually of
mine wastes rather than concrete. Water management is the cri-
tical problem. An adequate amount of freeboard must be main-
tained, cali
ated on maximum likely storm activity. If water is
adjacent to the dam itself, erosional or seepage processes may lead
to
eaching. The foundational geology is also a critical issue
earing on the stability of the embankments. TSFs in seismically
active or unusually high rainfall areas are especially vulnerable
(Vick, 1990; McLeod and Mu
ay, 2003).
The technical challenges of storing mine wastes are significant.
Nevertheless, I will argue here that the principal causes of TSF
failures are political rather than technical. Much is known within
the mine engineering community about how to manage tailings in
an environmentally sustainable way (Vick, XXXXXXXXXXThis generally
involves different techniques for removing the water. These tech-
niques are costly, however. Some companies may adopt them
voluntarily. It seems reasonable to suppose, however, that until the
companies generally are held to higher standards of best practice
in managing tailings, we will continue to see catastrophic TSF
failures.
Best practice bears on two issues in particular for the purposes
of this paper. The first concerns when and how environmental
considerations – in particular, the design of TSFs – are built into the
mine development process. The second concerns the actual tech-
niques involved.
I will show that when mining companies are held to the
highest standards, they can and do meet them. Whether or not
they are held to those standards depends in significant measure on
the regulatory environment. How exigent are the regulations, how
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comprehensive are they, and how well are they enforced? The
answers to these questions, I will suggest, have in part to do with
the influence of the industry in particular jurisdictions compared
with other land-intensive uses, especially as this bears on reg-
ulatory capacity and competence. Second, the social composition
of the su
ounding population also matters. Local populations with
political and financial resources will have a much greater chance of
escaping environmental disasters than those without such
esources.
In this paper, I will explore the histories of three mines. Two of
them suffered major TSF dam collapses with widespread and on-
going environmental damage: the Ok Tedi mine in Papua New
Guinea (PNG), and the Mount Polley mine in British Columbia. The
third mine – the McLaughlin mine in Northern California – is a rare
success story in which all of the environmental dislocations ne-
cessarily associated with mining were confined on site and, to a
significant degree, remediated after active mining ceased. The TSF
has retained its integrity. I have explored the Ok Tedi and
McLaughlin mine histories elsewhere and will summarize them
iefly here (Schoenberger, XXXXXXXXXXThe third case is more recent,
dating to August 2014. I will focus on the construction and
maintenance of tailings dams.
What I want to work through in this paper is why the failures
failed and why the McLaughlin mine succeeded at mining in an
environmentally sound and responsible way. Because the en-
vironmental damages of mining are closely linked to social harms
(through impacts on livelihoods, exposure to environmental toxins
and the like), it is particularly worthwhile getting at the causes of
oth success and failure in an effort to determine whether mining
can increasingly be done in a way that contains and remediates
environmental harms.
A second purpose of this paper is to suggest that a social sci-
entific analysis of engineered projects needs to pay attention to
the engineering. Because of the complex interplay among the
environmental, the social and the engineered, we risk missing
important information if we treat the engineered as a kind of black
ox. The reverse is probably also true. A quick search through
ecent journal publications on the topic of tailings storage facilities
shows that they are all in technical journals unlikely to reach a
social science or policy audience.
An important and promising exception to this is the 2011 pape
y Franks et al. in the journal Resources Policy. It provides an as-
sessment of the advantages and disadvantages of a range of waste
disposal methods and proposes a set of principles that could be
used to guide industry practice (Franks et al., XXXXXXXXXXI think we
need to press further in three ways.
First, it is clear that best practice under these principles will be
more expensive than many of the approaches that are in use today.
The industry as a whole has expressed its commitment to more
socially and environmentally responsible methods and, all othe
things equal, many operations can afford the additional costs and
may well implement them voluntarily (ICMM, XXXXXXXXXXBut marginal
operations may be hard-pressed or simply unwilling to adopt
them. Declining ore grades and declining commodity prices se-
parately and together are no doubt putting considerable pressure
on mining companies at the margin (Mudd, XXXXXXXXXXSo we need to
consider the degree to which voluntary adherence to the princi-
ples proposed by Franks et al. can be relied upon.
Second, I will try to show that the way the design of TSFs is
integrated into the overall development plan of the mine matters.
In
ief, it needs to be an integral part of the process of designing
the mine itself rather than being viewed as a separate problem.
Third, there is a question of who is able to comment author-
itatively on the design and operation of TSFs. The industry as a
whole is increasingly committed to meaningful participation by
local communities which is all to the good. Here, though, I want to
argue in favor of binding independent peer review of both the
design and operation of TSFs in additional to local stakeholde
participation.
Section 2 of this paper describes the research method. Sub-
sequent sections (3 through 5) describe and analyze the perfor-
mance of the three mines in question. Section 4 considers the
problems of TSFs more generally, focusing on what is considered
est practice by the engineering community and what conditions
might foster the wider implementation of this knowledge in the
design, construction, maintenance and closure of TSFs. Section 5
offers some concluding thoughts. An epilogue
ings some aspects
of the story up to date.
2. Research method
This research is qualitative and, in a sense, forensic. It is based
on a review of published and unpublished documents related to
the specific cases and to the engineering of TSFs in general. These
documents include technical post mortems of the two failed TSFs.
Other information was gathered from co
espondence with and
conference presentations of practicing engineers with many dec-
ades of experience in the construction and maintenance of TSFs.
Information was also gathered from company websites, govern-
ment websites and newspaper accounts.
I have only been able to make one site visit. This was to the
McLaughlin mine where I was guided by the former environ-
mental manager and the cu
ent manager of the TSF. One very
experienced field engineer was kind enough to review this
manuscript for technical accuracy. Some of my co
espondents
have prefe
ed to remain anonymous and I am obliged to respect
that request.
Case studies do not allow for statistical validation or general-
ization. They can, however, shed light on highly complex situations
and possibly provide the grounds for developing testable hy-
potheses (Schoenberger, 1991).
3. Tailings storage facilities: lessons from three mines
3.1. Ok Tedi
The Ok Tedi is an open pit copper and gold mine in Papua New
Guinea (PNG) developed from the early1980s by a consortium
headed by the Australian firm, BHP Billiton. It cost about US$1.4
illion to develop the mine