News

Tests done by specialized laboratories bring forth the results related to the Doce River sediments and water quality after the passage of the plume in the region of Linhares (ES).

– Sediments: metals present in the sediments (material deposited at the bottom of the river) are below the amount established by the Conama Resolution 454/12- level 1. That means that no anomalies have been identified, even after the passage of the plume. That is, the settled material in the Doce River does not present any danger to the environment. This result is in line with the report made available by CPRM (Brazilian Geologic Service), which presents data updated until November 18th, in the Minas Gerais region, closer to the dams.

– Metals in the fresh water: with the passage of the plume, some metals which were at the bottom of the river have moved and come up to the surface. Thus, some rates which were over the limit established by Conama for the class II rivers (Doce River classification) have been detected; however, still similar to the Doce River data from previous years, according to Minas Gerais IGAM monitoring. Regarding dissolved iron and aluminum, some values over the river parameters have been observed. Nevertheless, based on the reports concerning other impacted cities, these rates tend to decrease with time, after the passage of the plume.

– pH in the fresh water: since the beginning of the monitoring, the pH results have presented themselves normal, between the 6 and 9 rates, as established by the environmental legislation. These rates are appropriate for water life maintenance and show that the tailings are neither reacting with the water nor changing the river neutrality conditions.

-Turbidity: the turbidity, that is, the indication of solid presence in the water, has presented decrease throughout the days. The gathered materials present few solids, only colloids (small sized substances), which justify the reddish color of the river.

– Ecotoxicity: five different analyses of acute ecotoxicity (with a specific microorganism type) have been made, which point out that the Doce River water in the region of Linhares is not toxic to the environment.

– Tailings: the tailings coming from the Fundão dam were analyzed by the SGS Geosol – a company specialized in environmental and geochemical soils analyses. The report confirms that the material is not hazardous to people, based on the hazard classification of the material according to Brazilian standard of material hazardousness (ABNT 10.004). The samples were collected at several points close to the site of the accident to assure better representativeness of the tailings contained in the dams. These tests showed that the tailings are not toxic and do not present any hazard to human health, as they do not generate water contaminants, even when exposed to rain. In addition, since it is inert to all metals (except for iron and manganese, characteristic of local geology), one can conclude that the tailings do not contribute to the increase of other metals in the water.

In Linhares, Samarco has seven Rio Doce monitoring points (besides other 24 points in Povoação, Regência and at sea). Reports and analyses are generated periodically from the samples collected on these sites.