Fundação Renova

Common Questions

Are you looking for information about the actions managed by the Renova Foundation in the municipalities affected by the collapse of the Fundão dam? See the frequently asked questions list or, if you prefer, contact our team through Contact Us.


The levels of metals found in the water of the Doce River do not cause cancer. After the Fundao dam collapse, the Doce River water that was monitored showed peaks of metals predominant in the tailings of the dam (iron, manganese and aluminum), but also of other metals and elements. This occurred because the riverbeds and riverbanks where they were stirred up by the passing mud, generating high turbidity and bringing to the surface a great amount of contaminants, originating from activities carried out in the region over time – mining, industries, use of agrochemicals in crops, untreated sewage discharge etc.

Mercury, cadmium, copper and chromium, for example, are typical of the steel industry and mining areas. The arsenic identified in samples, especially in the coastal zone, is related to the rocks of the coastal region of Espirito Santo. The increased concentration of fecal bacteria and coliforms has to do with the discharge of untreated domestic sewage, which occurs in 80% of the affected area.

The main evidence that all these contaminants/elements were already present in the Doce River are records of more than twenty years of analysis logged by the Institute for Water Management of Minas Gerais (Igam).

Other evidence is the recurrence of iron and manganese in the soil of the region and they even sometimes appear in well water. The identification of cadmium in Ipatinga and Belo Oriente, in turn, probably has to do with some industrial activity.

When it rains, it is normal for the water in the river to get cloudy and muddy, because it mixes with the soil that gets loose from the banks. The Doce River always gets very cloudy in the rainy season. After the dam collapse, it became even more turbid because of the ore tailings.

As for the smell, it is due to domestic untreated sewage that is released in the river, generating this strong odor. Other causes are decaying organic matter, such as leaves and woods.

According to the Ministry of Health, no untreated water should be consumed by people. This is also true for water collected from the Doce River.

Regarding health risks – and regardless of the pollution caused by the tailings mud – the waters of the Doce may eventually cause health problems, like any other water, at any time, if consumed without proper treatment.

Nevertheless, to have a technical foundation, the Renova Foundation contracted an Epidemiological and Toxicological Sanitary Study. The bases of this study have been structured and it is being analyzed by the Technical Board of Health. This means that it has not been initiated yet, as it is waiting for approval by the Interfederative Committee (CIF).

What can be said at this moment is that, considering the Doce River’s historically, at times, high turbidity and high levels of fecal coliforms, caused by the discharge of domestic sewage, direct contact is not recommended.

It is important to know that, currently, the water of the Doce River has, in general, the same standards (characteristics) as before the Fundao dam collapse. This information can be confirmed by the reports issued by the Institute for Water Management of Minas Gerais (Igam), which has compared the pre-collapse results with the current ones. Igam has been monitoring the Doce River for more than 20 years, making it possible to consistently compare the results prior to the dam collapse with the current results.

The tailings are a residue, the remainder of iron mining. It arises because part of the existing iron ore in the Mariana region of Minas Gerais is of a type that appears in particles mixed with the soil itself. Thus, its mining requires large blocks of rock and earth to be crushed, washed and sifted continuously. Gradually, the iron is separated. What is left is a mud (the tailings), which is kept in dams, like the Fundao.

What leaked was non-toxic, since it essentially contained soil elements (rich in iron, manganese and aluminum) and water.

The high concentrations of metals and other contaminants found in the region’s rivers after the Fundao collapse appeared because the wave of tailings was mixed with waste that it dragged along from the banks and stirred up from the bottom of the rivers. This way it brought to the surface many potentially toxic substances deposited over centuries of economic exploitation in the region – not only mining, but also industry and agriculture.

The Institute for Water Management of Minas Gerais (Igam) has been monitoring the Doce River since 1997, through the Minas Water Program. This means there are extensive historical records on the quality of the river water. In the month of the Fundao dam collapse (November 2015), Igam expanded its monitoring, deploying more sampling points and increasing its frequency.

After the collapse, several monitoring activities were carried out, including emergency monitoring. In July 2017, the Renova Foundation implemented the Quali-Quantitative Systematic Monitoring Program (PMQQS).

In all, there are 92 monitoring points, distributed along the Doce River and its Gualaxo do Norte and Carmo tributaries, which were also directly impacted by the tailings of the Fundao dam. Of these, 56 points collect monthly samples for laboratorial analyses to monitor the water and sediments along the Doce River and 36 other points along the coastal zone. In 22 of the 56 river points, there are also automatic monitoring stations (which generate hourly data in real time).

Some 80 indicators are evaluated, such as turbidity, flow, presence of metals, contamination by bacteria, pesticides, etc. The information is stored in a database that can be accessed by public agencies that regulate and supervise Brazilian waters (Igam, National Water Agency, Ibama, ICMBio and AGERH*).

Specific investments in sewage and solid waste treatment complete the actions of the Renova Foundation to improve the water situation throughout the region affected by the Fundao dam collapse.

* AGERH is the State Water Resources Agency of Espirito Santo.

It is important to clarify that there is no official information by any environmental body on the release, or not, of water for irrigation and animal watering.

What is known is that the water of the Doce River currently has the same verified standards (characteristics) as before the Fundao dam collapse. Reports issued by Igam – the Institute for Water Management of Minas Gerais – confirm this information, comparing the results of pre-collapse with the current results.

And it is known that the waters of the Doce River for many years have had high rates of fecal coliforms (intestinal bacteria that reach the river, mainly due to the discharge of untreated sewage), besides other parameters outside the limits of legislation, such as, occasionally, certain types of metals and turbidity.