The paper presents and develops the issue of Cumulative Effect Assessment (CEA) in the Environmental Impact Assessment (EIA) screening procedure established by the State and Regional regulations In Italy. In the period 2001-15 in the territory of the Venice province (north east Italy, Veneto region) n. 328 projects (and the related environmental preliminary/definitive studies) were applied to competent Authorities (6% to the State, 39% to the Region and 55% to the Province). All the Environmental Impact Studies (EISs) and Environmental Preliminary Studies (EPSs) referring to the this territory officially applied to competent Authorities in the period 2001-2010, have been analysed with focus on the identification and assessment of cumulative effects (CEs); the projects considered and analysed for this purpose comprise a total of n. 181 EIA screening and ordinary procedures; the remaining 147 projects in the period 2011-15 (for a total of 328) are here considered only for statistical reason to an update assessment of project typologies in the same territory.
The methodology applied for the analysis of the sample of environmental studies in the period 2001-10 refers to that presented by Cooper and Sheate (2002) with modifications. The investigation has been developed looking for the way in which the topic is performed by practitioners in the environmental studies as from qualitative as well as quantitative point of view. Specific attention has been paid to waste management plants which are always subject to EIA screening procedure since 2008 according to Directive 97/11/EEC and in case to the whole EIA procedure. The approach proposed by Lombardia Region (North Italy; 2010) for EIA screening procedure of waste management plants has been applied to identify CEs and modified according to the characteristics of the considered territory; it allows the performance of the project-based approach and must be completed with a regional-based approach (Dubè, 2003). The proposed approach can be useful in case of waste management and IPPC (Integrated Pollution Prevention and Control, Directive 96/61/EEC, amended with Directives 2008/1/EC and 2010/75/EU) plants to define the financial warranties required for the authorization of operative activity of the plants to cover potential environmental damages produced in cases of accidents and other conditions as required in Europe (art. 14 Directive 2004/35/EC on environmental liability).
Several project categories were chosen and their EISs analysed as an exemplificative case according to the potential generation of cumulative impacts and the characteristics of the territory. With reference to the completed procedures where the competent Authority presented a final judgement, it has been observed that the CEA has been seldom developed due to not compulsory legal requirements as already observed by Burris and Canter (1997). Moreover, when it is considered, the methodology is limited and not systemized. Indices of impact have been identified according to emission for the main environmental components focussed with the analysis of the pressure factors of the plants. The study points out the need to analyse and evaluate the cumulative effects (CEs) at a strategic level (within the Strategic Environmental Assessment-SEA- procedure) with a view to preparing the study for EIA/EPS framework procedure for the projects derived from the corresponding plan/program. A sound knowledge of the considered territory and in particular of its pressure sources is of main importance for CEA assessment and impacts’ prevention. Geographic Information Sytesm (GIS) application is strongly needed for pressure sources’ census and control data storing.