About dams and tailings
Some technical terms with regards to dams can be found throughout this page. We have developed a
glossary that will help you to understand all of the information contained on this webpage.
- What is a dam and how does it work?
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- What are tailings?
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Tailings are the material that is left over after natural moisture processing of iron ore.
Tailings are composed of iron ore, sand, and water, and are not toxic, corrosive, or
flammable.
- What are the possible methods for construction and raising that can be used with dams?
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When a dam is built, a dyke is constructed in order to contain the iron ore tailings. This
is the starter dam. As the dam continues to receive more tailings, new layers are built onto
the starter dam - an operation that is referred to as raising. There are different types of
raising works that can be executed with dams. The main types of raising used by Vale are the
downstream construction method (the conventional model) and the upstream construction
method. In addition to these models, “Single stage” dams, which are not raised, are also
used. Learn more about single stage dams below:
Since the dam collapse at Brumadinho, Vale has committed itself to eliminating dam
structures that have been raised using the upstream construction method in line with
recent dam legislation that determined that these types of structures are to be
decommissioned.
Single stage tailings dams
No raising is executed under this model. The dam is constructed on soil or
compacted rockfill (large groups of rocks), without subsequent raising works
carried out to increase its capacity.
Downstream / conventional dam construction method
The dam shell is constructed on compacted soils regardless of the type of
tailings that are deposited into the dam. Raising is carried out in the
direction of the flow of water (downstream). The dam is built up on top of
itself, in the same direction as the current of waste, which improves the
stability of the structure.
Upstream dam construction method
The dam’s body is built using tailings through successive raising works that are
executed on the deposited tailings themselves. Raising is carried out against
the flow of water (upstream). Upstream tailings dams require thick tailings in
order to build the dam shell. The dam is built up on top of the initial dyke
using embankments that are made from the tailings themselves.
“Centerline” dam construction method
The centerline construction method is a variant of the upstream construction
method, in which successive raising is carried out in such a manner that the dam
crest remains in its initial position or, in other words, coincides with the
crest of the starter dam. Raises are built up on top of one another, maintaining
a symmetrical dam crest.
- Why do they exist?
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Dams exist for various purposes. A water dam, for example, can help generate hydroelectric
energy or increase water availability in a given location. In Mining, dams are part of the
ore production process that, after being extracted from the ground, undergoes the separation
of impurities. What remains of this process is deposited in the dams, which are reservoirs
for containing this material.
Vale’s dams
Vale’s dams
Do you know how many dams Vale has?
In Brazil, Vale has 110 dams, including active, paralyzed, defaced or under construction
structures. Of these, all those built in the upstream method, the same as the B1 dam in
Brumadinho, are being eliminated by the decharacterization process.
And where are they?
85 are in Minas Gerais, 19 in Pará and 3 in Mato Grosso do Sul. Of these, Vale has 67 dams in
operation and 37 inactive. We also have three other structures under implementation.
* Data according to structures registered under the National Dam Safety Policy (PNSB, in
Portuguese). Updated September/2021
The elimination of upstream structures
The process to eliminate the dams upstream of Vale, the decharacterization, encompasses many
stages, studies and care with the particularities of each dam. Our commitment is to eliminate 30
dams in Minas Gerais and Pará, 7 of which have already been delivered.
Understand which dams will be eliminated, the deadlines, locations and all the steps of this
process:
Dam Locations
Dam Locations
We have created a map in which it is possible to see where our dams are located, view photos and
documents
from the Emergency Action Plan for Mining Dams (PAEBM), as well as maps of the flood and emergency
procedures. The map can be viewed below:
Click under the states to see the dams concerned
Dams located in Brazil
Global Industry Standard on Tailings Management ("GISTM")
Vale has been reviewing and structuring its new tailings management policy day by day. This policy
is based on market best practices and ensures that our dams are safe.
To learn more about GISTM,visit
Vale’s ESG Portal
- Regular Safety Inspection Report (RISR)
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This report is reviewed twice a year in adherence to the requirements of DNPM (National
Department of Mineral Production)
Ordinance 70.389/17 from the Brazilian federal government, which allows us to monitor
Stability Condition Declarations (DCEs) and better understand the conditions found in
structures. This in turn allows us to provide increased quality in our processes for dam
monitoring and safety reviews.
Another important change in the monitoring of tailings dams is the inclusion of the Engineer
of Record. Previously, the standard was to contract engineering companies to perform
biannual audits in order to complete reports based on available information and often a
field inspection. EORs are now able to regularly monitor the structure of dams, which allows
us to provide RISRs that contain more information and that are more assertive in their
findings. Additionally, the EOR accompanies the implementation of recommendations for dams.
Vale’s goal is to achieve positive results for all structures that are assessed. For this
reason, we are investing in technology and optimizing factors related to safety at Vale.
- Independent Audit
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Performed by international companies, these audits are used to issue periodic reports that
meet the requirements of the Public Prosecutor’s Office. Whenever actions for reinforcement
are recommended, monitoring of dam stability is carried out by the same company that
performed the audit for a period of a year after work is completed on the dam.
- Partner in safety
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Vale has implemented the function of an Engineer of Record (EoR) as an additional step
towards strengthening its governance. The Engineer of Record is responsible for performing
regular safety inspections and issuing monthly technical reports with regards to the
situations found at tailings dams. If any changes in safety conditions are found at a
structure, a new Declaration of Stability (DCE) can be issued at any moment.
- Dam monitoring technology
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Vale’s dams are monitored 24 hours per day, seven days a week. High-tech instruments are
used to provide precise data, including video cameras that use artificial intelligence,
radar capable of detecting movements within a millimeter, inspection drones, piezometers
(which measure water pressure), and geophones (sensors used to measure both induced and
natural seismic waves).
Structure data is collected in real time and sent to Geotechnical Monitoring Centres (CMG)
located in Itabira and Nova Lima in the state of Minas Gerais and Parauapebas in Pará. All
information is continuously analyzed by Vale’s technicians. This allows us to verify
structure conditions and take preventative and corrective measures quickly and safely.
Emergency Action Plan for Mining Dams (PAEBM)
Structures that present a high potential for social, environmental, and cultural damages must
possess an Emergency Action Plan for Mining Dams (PAEBM). Additionally, dams with an average DPA
(Associated Potential Damage) are assessed and, if they are found to possess other characteristics
included on the list of criteria, they must also have a PAEBM in place.
The Action Plan is prepared, developed, implemented, and managed in accordance with the the
requirements provided for under legislation and protocols from municipalities and the municipal and
state Civil Defense.
The action plan established immediate actions that are to be taken in case of an emergency. Its main
objective is to plan measures that minimize risks and damages. The PAEBM includes:
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Flooding areas, in case the dam breaches;
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Arrival time at each structure;
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Meeting points and escape route;
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How to proceed in case the sirens sound;
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Information on monthly testing and geolocation of the sirens;
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Important contact numbers in case of emergency.
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Through technical studies that indicate the path of the tailings in a hypothetical dam rupture,
called a flood spot, the PAEBM establishes escape routes and meeting points. Periodically, the
ZAS community is oriented and trained on how to act in the event of an emergency.
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The PAEBM indicates where and how many emergency alert sirens need to be installed in each
location, covering all points in the spot area.
- The sirens undergo tests periodicals, including silent ones. In monthly tests, the sound emitted
by the sirens is an instrumental song. Thus, residents can differentiate when it is a test or
when the alert is real.
Discover the types of simulations below:
The drills are exercises for preparing and evaluating the protocols and procedures proposed for real
emergency situations. Through them, plans, protocols, agreements and procedures are tested and
validated, in addition to clarifying roles and responsibilities and identifying opportunities for
improvement.
These actions involve several teams, regions and disciplines, with tactical and strategic functions,
involved in the response to an emergency situation, such as command posts, monitoring centers and
hierarchical scale in decision-making.
The community's participation in the simulations is fundamental for the correct understanding of how to
behave in the event of a real emergency situation.
Constant dialogue
All PAEBM actions are discussed with the competent bodies and with the community itself. Professionals
explain when there will be simulated emergencies and what measures need to be taken by residents.
Learn more about the Self-Rescue Zones (ZAS) and Secondary Safety Zones (ZSS):
- Self-Rescue Zone (ZAS)
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All regions in which the competent authorities do not have sufficient time to intervene
in emergency situations. A distance is therefore adopted that corresponds to the arrival
of a flood wave which is equal to 30 minutes, or 10 km.
- Secondary Safety Zone (ZSS)
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This is the region located after the 10 km or 30 minutes that constitutes the ZAS. There
is sufficient time available in the ZSS for individuals with the proper training to
proceed with self-rescue and move towards the established meeting points. We wish to
reiterate that, when a level 2 or 3 emergency is determined to be occurring at a dam,
the ZAS is evacuated and those individuals in the ZSS are notified of the event.
Innovations
Safety innovations for operations and communities
Vale understands the importance of technology and is therefore investing in new dam monitoring
technologies. This is how we are able to provide agility and safety with our initiatives. Learn
more about the technologies used by Vale below:
Hover the mouse to learn more about these technologies.
Frequently Asked
Frequently Asked Questions regarding our dams
- What is Vale doing to guarantee that its tailings dams are safe?
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Vale monitors its dams at its Geotechnical Monitoring Centre 24 hours per day, 7 days a
week. The CMG integrates data from instruments located at more than 100 structures, using
various sensors and remote monitoring systems that provide real time transmission. In
addition, technicians periodically inspect dam structures. We also have a variety of
equipment installed at dams that measure different aspects of the structure. Internal and
external audits are also performed in which the work of technicians is verified by other
individuals both within and outside Vale.
There are also sirens that integrate dam alert systems. In addition to these sirens, we also
have a redundant operational system in place, which is part of dam management processes and
requires Vale to have infrastructure prepared to support systems in cases of a failure. For
example, if an operator fails to engage the siren, it engages automatically through means of
an automated system. We have redundant operational phases in place in electrical,
telecommunications, network, power, and other systems.
At Vale, we are focused on developing our Tailings Dam Management System in accordance with
rigorous international practices and legal requirements. We have also created channels that
allow for open and transparent dialogue with members of society, regulatory bodies, and
government agencies in order to reinforce safety at our operations.
- I keep hearing about the Emergency Action Plan for Mining Dams (PAEBM). What are the goals of
PAEBM?
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Create a culture of prevention within the communities in which we operate, identifying a
variety of situations and events that may put the integrity of dam structures at risk. PAEBM
also establishes resources and strategies for avoiding or minimizing social, environmental,
and economic impacts in a dam collapse scenario.
- What are some of the actions taken under PAEBM?
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Highlighted measures taken to ensure that PAEBM is correctly executed include:
- Emergency signaling: in partnership with municipal Civil Defense, signage displaying
evacuation routes and meeting points have been installed in Self-Rescue Zones (ZAS)
located within municipalities. Evacuation routes are routes that must be followed by
individuals in the event of an emergency. Meeting points are locations in which
individuals must gather when it is necessary to evacuate an area.
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Hypothetical dam break simulations provide communities and agents located in Self-Rescue
Zones (ZAS) with knowledge of the actions that are to be taken in case of an emergency
and training in how to proceed in case of a real-life emergency situation. These
simulations are carried out in partnership with municipal and state civil defense and
other emergency response organs.
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Siren tests are part of legal requirements that ensure the proper function of emergency
alert systems, verifying that sirens are functioning correctly and meet all necessary
requirements. The local population is notified of siren tests in advance and tests are
carried out in partnership with municipal Civil Defense. Commissioning consists of the
initial test verifying that the emergency alert system is functioning once it has been
implemented. After this initial stage, siren tests are carried out monthly at
pre-determined dates and times in accordance with schedules that are established
together with competent bodies.
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Training: in addition to simulations held in the community, we also carry out internal
training with Vale and third-party employees in order to ensure an appropriate rapid
response from all areas involved in an emergency situation.
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Risk communication: Vale maintains an informative communication system with communities
that are located near its operations. The themes that are touched upon in the training
include risk scenarios, evacuation routes, meeting points, signage, sirens, and
simulations.
- Are Vale’s tailings dams governed by any type of legislation?
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All of Vale’s dams in Brazil comply with legal requirements provided for under Federal Law
12.334, DNPM Ordinance 70.389, and resolution 51 from the National Mining Agency, as well as
Federal Law 14.066 of 2020.
- How will I be informed of a real emergency situation involving a dam?
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In a real emergency situation, you will hear the siren sound intermittently followed by the
following message: “Attention! Attention! This is an emergency. This is a real emergency
situation involving a dam collapse. Immediately exit your residences and follow the
evacuation route to the meeting point and await further instructions
The technical content on this webpage has been simplified to facilitate the comprehension of the
general public.
The PAEBM is to comply with Brazilian legislation and does not apply abroad.
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