The Procedure for Institutional Compatibility Assessment (PICA) has been developed within the SEAMLESS project as a formalised methodology to assess ex-ante the compatibility between a policy option and different institutional contexts. As a first empirical test of the tool, PICA was applied to the implementation of the Nitrate Directive in two study areas in Auvergne, France: the "départements" of Allier and Puy-de-Dôme. The paper presents the main conclusions that can be drawn from the empirical test in Auvergne regarding the practicability and quality of results of the procedure.