Since the 1970s, the outer suburban areas of Montréal, including Blainville, experienced substantial expansion, diversification of activities and increased management complexity. How can the social impacts arising from the development of major industrial projects be evaluated in such a complex environment? A temporal analysis of Blainville for the period 1977 to 1993, which includes the arrival of STABLEX (hazardous waste management), reveals the actors and development processes involved in the area's transformation. Information was taken from archives, local newspapers and census sources as well as a set of structured interviews with several local actors. After identifying the different events associated with or consequent upon the development of STABLEX, the direct and indirect impacts for land use planning and for managing the social environment are analyzed. In the discussion, the increased diversity of interests and of conflicts involved in the management of this area and of the role of STABLEX in this dynamic are highlighted.