F. Silvestri, G. Di Filippo (ISPESL, Productive Settlements and Environmental Deptartment, via Urbana 167, 00184 Rome, Italy)

E. Cardarelli (University "La Sapienza", Department of Hydraulics, Transport and Roads, Geophysical Area, Rome, Italy)

Natural risks may interact witl the risks coming from the industrial plants, especially from the high risk ones giving rise to a negative synergism. In Italy, as in other countries, the topical interest for this problem is proved by the increasing number of risk situations linked to a wrong approach to their analysis. In oder to get a complete evaluation of the interactions between industrial settlements and environment, it's necessary to consider their double connection: the effects both of a natural event on the plant and of the plant itself on the surrounding environment. Therefore, we need inforniation about territorial features, like hydrogeological and geomorphologic factors, and suitable safety measures, which are nowadays not available for specific situations. Finally, we suggest a standardization of evaluation procedures and risk mapping, aimed, in the preventive phase, at the localization and planning of industrial plants and, in the following phase, at the reclaiming, recovery and reinstatement of the environment. The paper examines the causes and the mechanism of the environmental risk, in particular hydrogeological factors, and its evaluation in one industrial area and illustrates the methodology and the results of its application.