Strategic Environmental Assessment (SEA) is a major policy evaluation tool, for institutional processes, when they need to cope with fundamental risks, give voice to non-human agents, manage commons, and address environmental justice. The interplay of SEA with planning, unravels key issues and criticalities in both urban governance and environmental democracy. How can evaluation be developed to support the process? Structured evaluation methods applied in environmental assessment are maybe not sufficient to solve complex social conflicts. We point out some key reflections with the aim of opening up the discussion, by taking the case study of the environmental assessment of pollutant activities in the main industrial port cities of Southern Italy. They represent, at the moment, the most significant social criticality in our country, related to the interplay between environmental assessment and risk for labor. The paper focuses on the case study by mentioning the evolution of some thoughts about the red stripe that links sustainability, environmental democracy, and social evaluation, and illustrates the issues of these aspects in the case study, with the aim of underlining the difficulty of environmental assessment tools as a major support for planning processes, when social conflicts arise.