Recital (31)

The judgments of the Court of Justice of the European Union, combined with additions to the lists of substances as well as stricter standards for existing pollutants, have rendered the application of the non-deterioration principle of Directive 2000/60/EC more challenging, in particular for projects that have a negative short-term impact on water bodies or projects and activities that have a negative impact on water bodies due to relocation of water or sediments containing pollutants. In the case of projects causing a negative short-term impact on one or more quality elements of a water body, it is essential to confirm that the negative impact on those quality elements is no longer detectable after one year or, for biological quality elements, after a maximum of three years. To ascertain that the negative impact is no longer present, it should be possible for Member States to use existing monitoring arrangements. However, such arrangements might not be sufficient, for instance where status is usually determined by extrapolation, or if the affected quality elements are different from those considered most sensitive to routine pressures and impacts, and thus not regularly monitored. In those cases, the ex-post verification should be done through supplementary and tailored monitoring. In the case of projects or activities having a negative impact on water bodies due to relocation of polluted water or sediments, the pollutant concentrations in the source-water body might decrease and those in the receiving water body might increase despite there being no overall change in pollutant mass balance. Such activities include the discharge of contaminated drainage water from construction works or the relocation of dredged sediments for flood protection or navigation and should be allowed, provided that several criteria are met. Those criteria should include a requirement that all practicable steps, including treatment, be taken to mitigate any adverse impact and that the receiving surface water body is already in less-than-good chemical status with respect to most of the substances relocated, and in particular with respect to the most persistent and bioaccumulative substances, such as PFAS, and that information relating to the criteria, and reasons for the relocation, are provided in the relevant river basin management plan. The criteria are intended to ensure that the overall level of protection of human health and the environment provided by Directive 2000/60/EC is maintained. The relocation of polluted water or sediment should not detract from the quality of drinking water resources, and a zone should therefore be established adjacent to any drinking water abstraction point where stricter precautions are needed. If Member States have already established safeguard zones under Article 7 of Directive 2000/60/EC, or Article 8 of Directive (EU) 2020/2184, those zones might serve the purpose.