Like in many countries, polluted industrial sites also exist in Belgium. Although the contamination is purely chemical in most cases, they may also contain a radioactive component. For chemically contaminated sites, extensive regulations and methodologies were already developed and applied by the different regional authorities. However and essentially because radioactivity is a federal competence, there was also a necessity for developing a legal federal framework (including an ER-methodology [1]) for remediation of radioactive contaminated sites. Most of the so-called radioactive contaminated sites are exhibiting a mixed contamination (chemical and radiological), and hence the development of such methodology had to be in line with the existing (regional) ones concerning chemical contamination. Each authority having their own responsibilities with regard to the type of contamination, this makes it more complicated and time-consuming finding the best solution satisfying all involved parties. To overcome these difficulties the legal framework and methodology — including the necessary involvement of the stakeholders and delineation of each party’s responsibilities — has to be transparent, clear and unambiguous. Once the methodology is developed as such and approved, the application of it is expected to be more or less easy, logic and straightforward. But is this really true? The aim of this document is to investigate as well the impact of factors such as the type of radioactive contamination — levels of contamination, related to NORM activity or not, homogeneous or heterogeneous, the differences in licensing procedures,… — on the application of the developed methodology and what could be the consequences in the long run on the remediation process. Two existing case studies in Belgium will be presented ([2]). The first case deals with a historical radium contaminated site, the second one with a phosphate processing facility still in operation, both with (very) low levels of radioactivity but containing very large volumes of contaminated materials. These case studies will demonstrate that, although the applied methodology will be the same in both cases, the impact of e.g. sampling strategy, scenario definitions, modelisations, final destination of the land, presence of chemotoxic components, dose or risk assessments, uncertainties, derivation of clean-up radionuclide guidelines, stakeholder involvement and waste treatment could be important on licensing, cost-estimate, planning and final outcome of the environmental remediation activities to be executed.
