The Fundão Tailings Dam Catastrophe …
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left abutment was moved from its previous position, placing the mass directly on top
of the previously deposited sludge. All conditions for liquefaction were created.
The expression “complexity-awareness” has recently been adopted in the context
of social change, participatory research, and project management by nongovernmental organizations (USAID 2018). Complexity awareness recognizes the prevalence
and importance of nonlinear and unpredictable interrelationships, nonlinear causalities, the existence of emergent properties, and that cause-effect analyses can only
be conducted retrospectively. With hindsight, it can be seen that the development
of an originally robust engineering project, because of implementation difficulties,
concept and design revisions and unanticipated conditions of use, led to a disaster
waiting to happen.
The trigger was the seismic shocks that struck the region approximately 45 min
before the dam ruptured. Although small in magnitude (2.5° on the Richter scale,
according to reports from the Center of Seismology of the University of São Paulo),
the mathematical model developed by the Panel indicates that this earthquake would
have caused a displacement of 5 mm in the left abutment, where mud and sand were
mixed. The Fundão Tailings Dam, already in critical condition, collapsed because
of a seismic shock that would have gone unnoticed had it occurred in a densely
populated urban area.
The Fundão Tailings Dam Review Panel emphasized technical issues; organizational failures are not explicitly affirmed. This is nothing new. Some authors have
repeatedly stated that it is difficult to place or assume responsibility for disaster events,
with studies generally focusing on technical issues, as they are the main cause of
the inevitability of disasters (Weick 1987; Turner 1994; Sagan 1996; Rijpma 1997;
Perrow 1999; Sutcliffe 2011; Aase and Tjensvoll 2014; Caro 2016). All these authors
reiterate the need for managers to pay special attention to weaknesses, warning signs,
different world views and unexpected situations.
In the Mariana disaster, not only the company but also public agencies and other
organizations failed in their missions to analyze and monitor mining projects and
activities. Again, with hindsight, the Minas Gerais Civil Police reported failures in
the continuous monitoring of the water level and water pressure. They also noted
the existence of defective monitoring equipment, whose readings were not carried
out when the dam safety report was issued, and poor monitoring due to the reduced
amount of equipment installed in the dam. They also found that the dam was rising
by approximately 20 m per year, on average, twice the maximum recommended in
the technical literature.
The Minas Gerais State Attorney’s Office, in turn, stated that the company had
been notified of risks related to the Fundão Dam as early as 2013. Indeed, the Public
Prosecutor of Minas Gerais considered that the disaster began in 2007, when Samarco
requested and received authorization from the Minas Gerais State Government to
build the dam, providing only some basic data about the project. These incomplete
data were considered sufficient by the Minas Gerais State Environmental Foundation.
According to the office, this was the first fault in the list of failures.
In addition, the lack of evaluation of geological studies on rainwater runoff, which
would make it possible to certify the safety of the structure, was considered the
393
left abutment was moved from its previous position, placing the mass directly on top
of the previously deposited sludge. All conditions for liquefaction were created.
The expression “complexity-awareness” has recently been adopted in the context
of social change, participatory research, and project management by nongovernmental organizations (USAID 2018). Complexity awareness recognizes the prevalence
and importance of nonlinear and unpredictable interrelationships, nonlinear causalities, the existence of emergent properties, and that cause-effect analyses can only
be conducted retrospectively. With hindsight, it can be seen that the development
of an originally robust engineering project, because of implementation difficulties,
concept and design revisions and unanticipated conditions of use, led to a disaster
waiting to happen.
The trigger was the seismic shocks that struck the region approximately 45 min
before the dam ruptured. Although small in magnitude (2.5° on the Richter scale,
according to reports from the Center of Seismology of the University of São Paulo),
the mathematical model developed by the Panel indicates that this earthquake would
have caused a displacement of 5 mm in the left abutment, where mud and sand were
mixed. The Fundão Tailings Dam, already in critical condition, collapsed because
of a seismic shock that would have gone unnoticed had it occurred in a densely
populated urban area.
The Fundão Tailings Dam Review Panel emphasized technical issues; organizational failures are not explicitly affirmed. This is nothing new. Some authors have
repeatedly stated that it is difficult to place or assume responsibility for disaster events,
with studies generally focusing on technical issues, as they are the main cause of
the inevitability of disasters (Weick 1987; Turner 1994; Sagan 1996; Rijpma 1997;
Perrow 1999; Sutcliffe 2011; Aase and Tjensvoll 2014; Caro 2016). All these authors
reiterate the need for managers to pay special attention to weaknesses, warning signs,
different world views and unexpected situations.
In the Mariana disaster, not only the company but also public agencies and other
organizations failed in their missions to analyze and monitor mining projects and
activities. Again, with hindsight, the Minas Gerais Civil Police reported failures in
the continuous monitoring of the water level and water pressure. They also noted
the existence of defective monitoring equipment, whose readings were not carried
out when the dam safety report was issued, and poor monitoring due to the reduced
amount of equipment installed in the dam. They also found that the dam was rising
by approximately 20 m per year, on average, twice the maximum recommended in
the technical literature.
The Minas Gerais State Attorney’s Office, in turn, stated that the company had
been notified of risks related to the Fundão Dam as early as 2013. Indeed, the Public
Prosecutor of Minas Gerais considered that the disaster began in 2007, when Samarco
requested and received authorization from the Minas Gerais State Government to
build the dam, providing only some basic data about the project. These incomplete
data were considered sufficient by the Minas Gerais State Environmental Foundation.
According to the office, this was the first fault in the list of failures.
In addition, the lack of evaluation of geological studies on rainwater runoff, which
would make it possible to certify the safety of the structure, was considered the