Cumulative Impact Assessment (CIA) is not disseminated in Brazil, although Environmental National Counsel (CONAMA) requires cumulativity and synergistic processes to be identified in the scope of Environmental Impact Assessment due to environmental permitting processes. Part of it is caused by methodological and technical issues, and part is caused because of public information gaps. In Brazil there are no consolidated methodologies to identify and analize social and environmental impacts caused by cumulative and synergistic processes, unlike United States, Canada and European Union which are considered benchmarks concerning CIA. Once analyzed, these methodologies show that not only CIA may be used as part of the environmental permitting process in Brazil, but also may be integrated to other planning, ordering and management territorial tools, such as the Ecological and Economic Zoning, since considering the chalenges, dificulties and responsabilities concerning the separated or combined adoption of these two instruments. This approach may be considered as an alternative to social and environmental management and planning concerning Sepetiba Bay, where, since the 1970 s there is a severe social and enviromental degradation process in course, intensified by the 2000 s because of the expansion of the Sepetiba’s Industrial Center, where three enterprises may be highlighted: Companhia Siderúrgica do Atlântico (CSA), o Porto Sudeste and Complexo Naval de Itaguaí.