Recital 17

(17)Tertiary treatment should also be mandatory in agglomerations of 10 000 p.e. and above that are discharging into areas subject to, or at risk of, eutrophication. In order to ensure that efforts to limit eutrophication are coordinated at the level of the relevant basins for the whole catchment zone, and to ensure the consistent designation of sensitive areas across the Union, areas where eutrophication is considered an issue according to currently available data should be listed in this Directive. Additionally, in order to ensure the coherence of relevant Union law, Member States should identify other areas subject to, or at risk of, eutrophication on their territory, and identify whether those areas are nitrogen- or phosphorus-sensitive, or both nitrogen- and phosphorus-sensitive in particular on the basis of data collected under Council Directive 91/676/EEC ¹⁰ , Directive 2000/60/EC and Directive 2008/56/EC. The reinforcement of the limit values, the more coherent and inclusive identification of the areas sensitive to eutrophication and the obligation to ensure tertiary treatment for all large facilities would, in combination, contribute to limit eutrophication. Since this will require additional investment at national level, Member States should be given sufficient time to establish the required infrastructure.