We publish below the article by Carmen Chierchia published on Il Sole 24 Ore on March 18, 2019 on the criterion "of the most probable that not" in the matter of identification of the responsible party in case of pollution.

A "good degree of probability" is enough to identify the subject that caused or contributed to cause environmental contamination. In other words, it is possible to apply the principle "of the most probable that does not", ie the criterion that identifies the causal link between a given effect and the conduct of a given economic operator. With sentence no. 7121 of December 16, 2018, the Council of State reiterated that to affirm the existence of a causal link between the action of the responsible subject and environmental contamination it is not necessary to reach a level of probability close to the certainty of the test, since subsistence is sufficient of plausible indications that allow the overcoming of contamination thresholds to be attributed to a given subject. With regard to pollution, the "polluter pays" principle applies, but in practice, it is often difficult to accurately identify the responsible party. Corporate changes of the owner, transfers of property rights to the polluted area, changes in the industrial activity that generated the pollution, are some of the many hypotheses that cause confusion in identifying the subject who, with his productive activity, has caused or contributed to contamination. When the reliable identification of the person responsible for the pollution is difficult, the principle "of the most likely that is not" is triggered. A type of proof, developed in a civil law context, which differs considerably from the penal law according to which responsibility can be attributed only if there is certainty beyond any reasonable doubt. But because the circumstances of the "most probable that do not" occur:

  • plausible indications, according to the Council of State, the competent authority must have plausible indications capable of giving foundation to its presumption. The circumstantial elements that the jurisprudence has evaluated as plausible are attributable to two categories: the geographical one, given by the proximity of the plant to the pollution and the objective one, which derives from the correspondence between the polluting substances and the components used in the activity's activity;
  • in-depth investigations, the principle of "more likely than not" does not mean approximate investigations or unfulfilled reasons for the identification of the responsible party.

The investigations that lead to the identification of the responsible must be based on meticulous reconstructions of the type of production, of the substances used, of the plant and production modifications occurred over time, as well as on the analysis of the morphological trend of the polluted territory and of the other factors that can having influenced the contamination (Tar Brescia, sentence 24 September 2018, no. 897). The subject identified as being responsible by the Province, who wants to contest this qualification, is instead required a less circumstantial probative effort: it must in fact provide evidence that, while not assuming the characteristics of "certainty", is capable of seriously questioning the thesis of the administration. In particular,