L 78/40 Official Journal of the European Union 24.3.2015 COMMISSION IMPLEMENTING DECISION (EU) 2015/495 of 20 March 2015 establishing a watch list of substances for Union-wide monitoring in the field of water policy pursuant to Directive 2008/105/EC of the European Parliament and of the Council (notified under document C(2015) 1756) (Text with EEA relevance) THE EUROPEAN COMMISSION, Having regard to the Treaty on the Functioning of the European Union, Having regard to Directive 2008/105/EC of the European Parliament and of the Council of 16 December 2008 on environmental quality standards in the field of water policy, amending and subsequently repealing Council Directives 82/176[EEC, 83/513EEC, 84/156/EEC, 84/491/EEC, 86/280/EEC and amending Directive 2000/60/EC of the European Parliament and of the Council (), and in particular Article 8b(5) thereof, Whereas: (1) Article 8b(1) of Directive 2008/105/EC provides for the establishment of a watch list of, in the first instance, up to 10 substances or groups of substances for which Union-wide monitoring data are to be gathered for the purpose of supporting future prioritisation exercises in accordance with Article 16(2) of Directive 2000/60/EC of the European Parliament and of the Council (). The list should include an indication of the monitoring matrices and possible methods of analysis not entailing excessive costs. (2)  Article 8b of Directive 2008/105/EC specifies, inter alia, the conditions and modalities for the monitoring of the substances included in the watch list, for the reporting of the monitoring results by the Member States, and for the updating of the list. (3)  The substances in the watch list should be selected from amongst those for which the information available indicates that they may pose a significant risk, at Union level, to or via the aquatic environment, but for which monitoring data are insufficient to come to a conclusion on the actual risk posed. Highly toxic substances, used in many Member States and discharged to the aquatic environment but not or rarely monitored, should be considered for inclusion in the watch list. That selection process should take into account information as itemised in points (a) to (¢) of Article 8b(1) of Directive 2008/105/EC, giving particular consideration to emerging pollutants. (4)  The monitoring of the substances in the watch list should generate high-quality data on their concentrations in the aquatic environment, fit for the purpose of supporting, in a separate review exercise according to Article 16(4) of Directive 2000/60/EC, the risk assessments that underpin the identification of priority substances. In that review, substances found to pose a significant risk should be considered for inclusion in the priority substances list. An environmental quality standard would then also be set, which Member States would have to meet. The proposal of a substance for inclusion in the priority substances list would be subject to an impact assessment. (5)  In accordance with Article 8b(1) of Directive 2008/105/EC, diclofenac, 17-beta-estradiol (E2) and 17-alpha- ethinylestradiol (EE2) should be included in the first watch list, in order to gather monitoring data for the purpose of facilitating the determination of appropriate measures to address the risk posed by those substances. Estrone (E1) should also be included in the watch list because of its close chemical relationship to 17-beta- estradiol, of which it is a breakdown product. (6)  During 2014, the Commission gathered data on a range of other substances that could be included in the watch list. It took account of the information sources referred to in Article 8b(1) of Directive 2008/105/EC, and consulted experts from Member States, and stakeholder groups. A ranking process was conducted. This considered in particular substances which came close to being prioritised in the most recently completed priority substances review, but for which monitoring data were still needed to confirm a significant risk. It also () OJL 348, 24.12.2008, p. 84. () Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy (O] L 327, 22.12.2000, p. 1).