Análise das experiências de outorga de diluição de efluentes em prática no Brasil e proposições de aperfeiçoamento.

Abstract

The granting of usage rights is an instrument of the National Policy on Water Resources that aims to ensure the quantitative and qualitative control of water uses and the effective exercise of access rights to water resources. In this context, the granting of dilution of effluents is attached, and it's goal is to assist in the qualitative management of water bodies. The three basic pieces of information for a decision support system for the granting of dilution of effluents are: natural water availability, the quality threshold allowed (framing of water bodies in use classes) and the total amount of resources already committed to existing uses. With these three pieces of information, the system will be apt to start the control operation; the more accurate the information s are, the more faithful to reality will be the information returned by the system. The main objective of this study was to analyze the Brazilian granting experiences of dilution of effluents, identify their strengths and limitations in their application and present proposals for improvement. The seven experiences in effect in Brazil were analyzed, namely: Union (União), Bahia, Espírito Santo, Paraná, Mato Grosso, Minas Gerais and Federal District (Distrito Federal). The research developed comprised extensive bibliographic revision and interviews/discussions with specialists on the area. The results showed that there is an oversimplification in the application of the granting of dilution of effluents, making it so that none of the experiments analyzed managed to achieve the fullness of their potential. It was also possible to conclude that the lack of framings of water bodies, based on technical criteria and with realistic goals, makes the application the granting of dilution of effluents extremely hard, distorting its functionality and causing inconveniences to entities of the water resources management system. Finally, proposals were general guidelines on the granting of dilution of effluents in order to make it an important tool for qualitative management of water bodies, preventing that the quality thresholds set by society are exceeded and drawing attention to the commitment level of water availability.