Water

Reparation

Water

Recovery Measures

It is Vale's duty and priority to carry out actions aimed at the environmental recovery of the entire area impacted by the collapse of Dam B1 in Brumadinho.

Environmental restoration is divided into five fronts:

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Preservation of local flora and fauna;

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Removal of tailings on land and in the river, allocating them to safe and controlled areas;

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Containment of tailings, preventing them from reaching the river during rainy periods;

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Monitoring and restoration of water and soil quality;

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Human and ecological health risk assessment studies.

On this page, you will learn a little better about the activity of monitoring the water quality of the Paraopeba River.

In order for you to better understand all the information on this page, we have produced a glossary. Click here

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Water quality monitoring

Since January 2019, Vale has been carrying out water quality monitoring work in the Paraopeba River basin, its tributaries, as well as stretches of the São Francisco River, although the latter were not affected by the B1 Dam failure.

In addition to the monthly monitoring carried out by the Minas Gerais Water Management Institute (Igam), the quality of the waters of the Paraopeba River and its tributaries is monitored by Vale, respecting the commitment assumed with the responsible public bodies. All this work is accompanied  by an independent technical and environmental audit, appointed by the Public Ministry of Minas Gerais (MPMG).

The data obtained by the monitoring works are  eriodically delivered to Organs inspection bodies and to the Public Ministry of Minas Gerais.

Discover here all the monitoring points that exist today

Hover the Mouse over the map to see more details

Hover the Mouse over the map to see more details


But, after all, how is water monitoring done?

Mouse over the icons to learn about the process

Conventional monitoring is carried out by sampling surface water in several stretches of the Paraopeba River and in main tributaries, at frequencies that vary between weekly and monthly. Samples of sediment deposited in river beds are also collected.

The collected samples are sent to specialized laboratories for analysis of physical, chemical and biological parameters, totaling more than 150 variables. Following validated analytical methods, it is possible to identify any change in the quality of water, sediments and local ecosystems.

Automatic monitoring is also carried out to obtain water quality data. In total, 11 telemetric stations are installed on the Paraopeba River, which allow the remote measurement of physical and chemical water parameters, every hour, with data transmission via satellite, increasing the efficiency of information.

The work carried out is validated and monitored by supervisory bodies and national and international educational institutions: Coppe-UFRJ, UFMG, UFLA, IFTM, UNESP, University of Illinois (USA) and University of Trás-Os-Montes and Alto Douro (Portugal ).

What results have been obtained so far?

  • The tailings were retained at the Retiro Baixo Hydroelectric Plant, in Pompéu (MG), not reaching the São Francisco River;
  • There was no contamination in the waters of the Três Marias Hydroelectric Power Plant reservoir, as shown in studies by environmental agencies;
  • Heavy metal levels are progressively decreasing during the dry period;
  • Statistical tests show a significant trend towards improvement in water quality during the dry season.

Metal concentration

Since January 2019, a complete list of metals has been analyzed in water and sediment samples from the Paraopeba River, main tributaries and also in points in the reservoirs of the Retiro Baixo and Três Marias Hydroelectric Power Plants.

The presence of metals in water can also be associated with the dissolution of compost from the soil, and the contents of these metals are directly related to the geological composition of the places where water bodies are inserted or discharge of industrial effluents and other human activities.

How to interpret maps

To verify the quality condition of the Paraopeba river stretches, a comparison is made of the monthly maximum result of each parameter with the maximum of the seasonal periods obtained before the disruption by Igam monitoring.

The result of this comparison with the pre-disruption period (called baseline) is graphically represented by colors, ranging from the best result (blue) to the worst (red), as follows:

pre-breakup condition

worst condition

Dissolved iron

Total manganese

The Paraopeba river basin crosses the region known as the Iron Quadrangle of Minas Gerais, and records of naturally high concentrations of iron and manganese in the waters are common, even above the quality standards, even in the historical series of data from Igam before the break.

In the monitoring carried out by Vale,   significant results of these metals were identified in stretches more impacted by the input of tailings, with attenuation as we move away from the region where the Ferro-Carvão stream meets the Paraopeba river. The contents of manganese and iron, in total form, show an increase in the rainy season and a reduction in the dry season, and the current condition indicates that the water quality is in a transition phase, with a progressive reduction in concentrations.

Dissolved aluminum

The analysis of aluminum metal has shown significant concentration levels, which may be associated with the tailings. However, specifically in the stretch of the Paraopeba River after the municipality of Maravilhas, it is observed that natural geological factors influence the increase in the concentration of this element.

Trace metals

Other metals can also be found in water in much smaller amounts and sporadically, they are called "trace metals". Some analytical results pointed to isolated occurrences of pronounced concentrations for trace metals.

However, for these elements, which are also present in the tailings, the data analyzed currently show that the levels in the Paraopeba River are similar or even lower than those recorded in public databases for the pre-rupture period.

Turbidity

Turbidity is a basic parameter for assessing water quality, easily influenced by rainfall and related to the transparency and quantity of suspended particles

The presence of suspended solid materials such as clay, organic and inorganic matter, microscopic organisms and algae cause water turbidity.

The origins of these materials can be diverse:

  • River bottom sediments;
  • Soils on the banks and in areas with suppression of vegetation;
  • Mining;
  • Sand removal or clay exploration;
  • Industrial waste;
  • Domestic sewage .

Understand the difference in water behaviour in the rainy x dry season

Climatic aspects have a relevant influence on water quality. During rainy periods, the water tends to become more turbid, mainly due to the carrying of materials from the banks and the resuspension of sediments from the bottom of the river. On the other hand, in periods of drought (drought), the rivers present reduced flow, low flow velocity and less resuspension of sediments, resulting in better measurements of some parameters.

Regarding the Paraopeba River, we can say that, in periods of drought, the water quality approaches the conditions prior to the break.

The joint analysis of the dissolved aluminum, dissolved iron and total manganese parameters shows that there is a progressive reduction in the concentration of these parameters, indicating recovery close to the conditions of a class 2 river in periods of drought.

During the rainy season, the water quality worsens, as has happened in the past. The increase in the concentration of some of these parameters such as aluminum, iron, manganese and turbidity may be related to the suspension of the material deposited on the riverbed and the new contributions caused by natural soil materials in the region, or due to other activities historically carried out in the region.

The evaluation of the water quality of the Paraopeba River and its tributaries continues to show results that indicate the  reduction of several physicochemical parameters, regardless of the influence of climatic factors.

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Monitoring in numbers

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Monitoring of the Paraopeba River by IGAM

Vale signed the Term of Commitment (TC) with the Public Ministry of the State of Minas Gerais (MPMG), which establishes the  transfer of all monitoring actions of water resources and sediments along the Paraopeba River Basin and in the São Francisco River for the Minas Gerais Water Management Institute (IGAM). To absorb the monitoring data after the breakup, Vale is developing, together with IGAM, a water monitoring software for the entire State of Minas Gerais. Vale  hires a technical and independent auditor, who is responsible for overseeing the entire transfer process, which is expected to take 33 months after the signing of the Global Agreement.

Access the Igam newsletters here
What is the role of Igam in overseeing the monitoring and analysis of the recovery of the Paraopeba River?

Igam has a fundamental role as a supervisory body, in the scope of evaluating the results and studies related to the sampling carried out by Vale, as well as in requesting responses and proposing changes in the way the work is being carried out.

Liberation of the use of water from the Paraopeba river

Igam reinforces that the recommendation of not using raw water from the Paraopeba River for any purpose is still maintained, as a preventive measure, in the stretch that covers the municipalities of Brumadinho up to the limit of the Retiro Baixo HPP, in Pompéu (approximately 250 km from distance from the break). The use of water in the stretches before the municipality of Brumadinho (before the stretch affected by the rupture) and after the Retiro Baixo HPP are authorized for a wide range of purposes and there is no restriction by public bodies.

Monitoring the quality of the water is essential to subsidize the agency and, in the future, allow the resumption of use. This is a decision that does not depend on Vale, and to support the assessment of the water quality condition, the monitoring results are periodically sent to the State's supervisory bodies.

Cycle Closing Report: understand what it is for and what is done with it

The Cycle Closing Report contemplates the evaluation of monitoring data within the scope of the Monitoring Plans.

It presents the behaviour of the results of monitoring of surface waters and sediments in the Paraopeba river basin up to the Três Marias reservoir, in different seasonal periods.

The document aims to present an assessment of the quality of water and sediment, bringing into consideration the variations that occur during the rainy and dry periods of the hydrological cycles, over the years of monitoring.

Click here to see the complete report

Water Distribution

Vale supplies water for rural properties and residences that depended on water withdrawal from Paraopeba river or water tables located less than 100 meters from the river bank. Demands are met according to each action front:

Corrective actions

Actions towards animal and human consumption, as well as production irrigation.

Preventive actions

To guarantee water safety in locations affected by B1 dam breach, Vale is conducting several construction works, such as drilling of artesian wells, installation of high-performance filter systems, and implementation of stations for water withdrawal and treatment.

Location

See below the municipalities to which Vale works on water supply.

  • Brumadinho
  • São Joaquim de Bicas
  • Mário Campos
  • Betim
  • Esmeraldas
  • Juatuba
  • Florestal
  • Pará de Minas
  • São José da Varginha
  • Pequi
  • Pompéu
  • Curvelo
  • Maravilhas
  • Papagaios
  • Paraopeba
  • Fortuna de Minas

Volume of Water Distributed

Up to now, Vale has already distributed a total of

805.7
million liters of water

Irrigation
415.3 million liters
Animal consumption
253.6 million liters
Human consumption
136.8 million liters
Data from August 2nd, 2020

Construction Works for Water Supply

Water Supply Systems

Construction works of new water supply systems to serve the population of Pará de Minas and metropolitan area of Belo Horizonte are underway. The systems include the construction of three new pipelines. Two of them are for water withdrall, one on the Pará River, in Pará de Minas, and the other on the Paraopeba River, located 12 km above the current withdrall structure, in Brumadinho. The other will interconnect the water supply systems of the Paraopeba River Basin to that of the Rio das Velhas Basin, located in the Novo Glória neighborhood in Belo Horizonte.

The pipeline that will make the interconnection between the systems will guarantee the improvement in the current distribution system and was designed to meet a flow rate of 430 l/ s.The others construction works will guarantee the same flow rate of the interrupted withdrawal systems, and operations will be carried out by the Water Utility Company of Pará de Minas (Capam, Concessionária Águas de Minas Gerais) and Sanitation Company of Minas Gerais (Copasa, Companhia de Saneamento de Minas Gerais).

Protection of Bela Fama

Although it was not impacted by the Dam I breach, the Das Velhas river is receiving a preventive investment. Among the initiatives contemplated in the investment is the installation of a containment barrier that surrounds the catchment of Bela Fama, in Nova Lima. This barrier is approximately 3 meters high and 300 meters long and its works were completed in december 2019. In addition to the barrier, Vale is also studying a complementary system for the Bela Fama Treatment Station, with the aim of strengthening the system, increasing the efficiency of current treatment processes and ensuring water potability.

R$559 million are being invested

The water supply system in Pará de Minas is expected to be delivered in July 2020

The RMBH water supply system, in Brumadinho, is expected to be delivered in September 2020

The pipeline system that will interconnect systems in Belo Horizonte is expected to be delivered in March 2020

Drilling and Reactivation of wells

Another action that Vale has taken is the drilling of tubular wells in some regions for water supply.

Until now, Vale has already drilled

76 wells in 15 municipalities
  • Pará de Minas
  • Paraopeba
  • Caetanópolis
  • Barão de Cocais
  • Brumadinho
  • Betim
  • Esmeraldas
  • Fortuna de Minas
  • Maravilhas
  • Mario Campos
  • Papagaios
  • Pequi
  • Pompéu
  • São Joaquim de Bicas
  • São José da Varginha

High performance filters

Vale is making water filtration equipment available to rural producers using wells and cisterns near the Ferro-Carvão stream and the Paraopeba river. The forecast is that by the month of June, around 250 systems will be available in 20 municipalities, from Brumadinho to Três Marias. The filters aim to make the water potable, complying with the regulations. The different technologies for treatment are selected for each property, according to the level of water quality in wells or cisterns, in order to guarantee the safety of users.

River Water Treatment Plant

The River Water Treatment Plant (ETAF, Estação de Tratamento de Água Fluvial), located in the region of Alberto Flores, started its operations in May 2019; it can treat almost two million liters of water per hour, which corresponds to almost 20 Olympic-size swimming pools a day. It aims to clean the Ferro-Carvão stream and dispose the treated water in the Paraopeba River.

About ten billion liters of clean water have already been treated and returned to Paraopeba river

How Does It Work?

A sheet pile curtain has been installed for river tailings containment. The water from this area is withdrawn and pumped to the ETAF

In the ETAF, solids are separated by decantation; then, the water is filtered and returns clean to the tributary of the Paraopeba

The solids decanted in the sedimentation basin are sent to large containers – known as geotextile tubes – to contain, store, and dewater the tailings

The water drained from these containers is sent to the filtering system installed and, then, to the river

Solids retained in the geotextile tubes are removed and transferred to an area previously defined and authorized by relevant authorities

Learn More about the Impact of Tailings on Paraopeba River

What Is Water Turbidity?

It is a physical property of liquids that reduces transparency due to the presence of suspended material that affects the path of light through the fluid. It works as an important parameter for the adequate conditions of drinking water.

What Causes Turbidity?

Turbidity is caused by the presence of some suspended solids, such as silt, clay, silica or colloids, organic and inorganic matter, microscopic organisms, and algae. These materials come from several sources – soil, mining, sand withdrawal or clay exploration, industries, or domestic sewage. After heavy rainfall, surface waters also become turbid due to sediments flow from the banks.

Are Tailings in Paraopeba River Harmful to Health?

Iron ore tailings are mostly composed of ferrous minerals and quartz, considered inert, as per NBR 10.004 from the Brazilian Technical Standards Association.

Are There Studies about the Impact of Toxic Substances on the Environment?

Vale has concluded ecotoxicity tests with bacteria and aquatic invertebrates (according to ABNT standards) on water and sediment samples collected along the Paraopeba River to the São Francisco River, in order to understand the consequences of tailings deposits in the watercourse for biodiversity.

So far, there are more than 10,000 ecotoxicological analyzes, including the periods before and after the passage of the tail plume. In addition, about 4 million physical-chemical analyzes of water, soil and sediments have already been carried out on more than 31 thousand samples. These analyzes monitor various parameters, such as the presence and quantity of metals, pH and water turbidity.

The tests carried out during the dry season indicated an attenuation of the concentrations of the analyzed elements, resulting in a greater number of parameters within the limits allowed by the legislation. Studies continue to be carried out during the rainy season.

The work is conducted by independent specialized laboratories and involves approximately 250 professionals.

Is It True that Heavy Metals Are Native to the Region?

Analyses of 1,019 historical soil samples from the region conducted by the Brazilian Geological Survey Organization (CPRM, Companhia de Pesquisa de Recursos Minerais), and 124 sediment samples collected by Vale’s Mineral Development Center (CDM, Centro de Desenvolvimento Mineral) at the watershed, show that arsenic and lead concentrations in the area affected by tailings are in line with those of other regions and below the acceptable threshold established by the resolution 420/2009 from the National Council for the Environment (Conama, Conselho Nacional de Meio Ambiente). Historical geochemical data have shown that metal concentrations in tailings are below or at the same level as those recorded in public databases about soil.

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