Subproject 9+11

Surface Water and Sediment Sampling in the Paraopeba River and Tributaries

The research will perform water and sediment monitoring after the breach of the B1 dam. It will assist in the diagnosis of the quality of the affected ecosystems and allow, for example, the suggestion of mitigation measures for impacts in the medium and long term. The collection of surface water and sediments along the river and over the months will allow the intensity of the disturbances caused by the mining tailings spill along the Paraopeba River and its tributaries to be evaluated, thus allowing such impacts to be catalogued along different parts of the river and reservoirs and compared to reference areas. However, for such impact analysis to be carried out, it is necessary to systematically, rigorously and carefully collect samples, thus ensuring the reliability of the results found so that they can serve as subsidies for damage mitigation plans and can meet the main objective  which is the assessment of the environmental impact caused by the disaster of the dam break. To this end, surface water samples will be collected from the Ribeirão Ferro-Carvão and the Paraopeba River to the Retiro Baixo Reservoir, where it is planned to include some points within the reservoir. Control points will also be evaluated in a more preserved water body, which will be taken as a reference, for the purpose of comparison with impacted water bodies. These objectives unfold in the following actions:

• Discuss the sampling plan with the Committee;
• Purchase consumables and equipment that will be used to collect the surface water and sediment samples;
• Organize and train collection teams with the participation of auditors;
• Coordinate the collection of surface water and sediment samples; 
• Transport and pack the samples in a location determined by the Committee;

Methodological Steps: 

Surface water and sediment collections will be conducted at 44 points, following the  sampling delineation of Annex III of the induced internal public calls # 09/2019 and  11/2019. The sampling points are located in the Paraopeba River, Ferro Carvão creek and the Retiro Baixo HPP. As a reference, a microbasin of the  Paraopeba with a more preserved water body, the Macaúbas River, in Brumadinho, will be used. 

The proposal was divided into five stages (described below). Complementary information  to the methodology is in the form of Appendices. 

Stage 1 - Procedures preceding the start of field sampling;

Stage 2 - Validation of the sampling points; 

Stage 3 - Field team training;

Stage 4- Preparation and collection of surface water and sediment samples;

Stage 5- Delivery of products (samples and reports); 

Meet the team!

9+11 Subproject Timeline