The Quintero-Puchuncavi area, internationally known as an environmental "sacrifice zone," is legally declared as a "saturated zone" due to atmospheric pollution (PM2,5) associated with the Ventanas Industrial Complex (VIC). While contamination problems date back to the late 1960s, they have persisted and grown in the last 25 years despite the existence of an environmental impact assessment system (EIAS) that ultimately should have allowed a sustainable development. Based on a retrospective analysis of the environmental assessment processes developed for different projects exiting in the VIC, this research finds that a great majority (i.e., 87% of 68 projects) entered the EIAS in the form of a Declaration of Environmental Impact. This implies low requirements and depth of analysis in the evaluation processes, normally lack of public participation processes, and operates, in practice, in a "case-by-case" analysis. Also, the research finds that the evaluation processes have been distorted by limitations in the estimation of emissions and atmospheric pollutants transport and fate modeling. The lessons obtained from this case study, and the proposals for improvement made in this work, transcend this single case and are relevant for other countries with similar EIASs that are facing parallel sustainable development challenges. Improvements are required in the environmental impact assessment system, so that this instrument can effectively fulfill its role in terms of ensuring the sustainable development of the localities where projects are carried out, especially in areas of high industrial concentration such as the VIC.