General Principles and the Duty to Undertake an EIA: Relationship, Requirements and Practice

The aim of the chapter is to revisit the ICJ judgment Pulp Mills on the River Uruguay case, decided in 2010, in order to appreciate the evolution of the EIA under international law and its relationship with other fundamental international law principles and rulesof international law. The scope is limited to transboundary EIAs. After briefly analysing the most significant international decisions regarding the duty to undertake an EIA, the question that will be answered is not to assess whether, but how and under which circumstances an EIA must be undertaken. It will be argued that an EIA is a flexible tool and that its content is impossible to define in general terms under customary international law, except for some basic requirements, including public consultation, which must be considered as a fundamental part of the process. As a consequence, EIAs must be shaped according to the geographical area and the type of project under analysis. The article will then explore the relationship between the duty to undertake an EIA, on the one hand, and some “traditional” principles of international environmental law, such as, for example, the “do not harm” principle. The second part will examine the relationship of EIAs with sustainable development, precaution, biodiversity, and human rights. It may be stated that transboundary EIAs have evolved from an element of the general obligation of due diligence in the prevention and control of transboundary harm, therefore with a focus on inter-State procedure, to an essential component of the relation human rights-environment. It will eventually be argued that the relation human rights-environment must also include a gender dimension.