Applicability of H14 Protocol for Sediments in Order to Consider Their Valorization: Limits and Benefits

International audienceCommunity and national regulations impose to do not discharge harbor sediments into the sea without first measured the level of pollution and assessed the risk of impacts on the marine environment by the use of ecotoxicity tests on marine species. If the immersion is impossible, sediment has to be directed to inland areas where they have the status of waste. Then, it must identify whether the waste is hazardous or not. The H14 "ecotoxic" property of the EU Waste Directive, which is conventionally used for the characterization of hazardous waste in case of multiple contaminations, can be applied to sediments. In case of strong positive response to ecotoxicity tests on terrestrial species, the sediment must be managed as a hazardous waste and it must be oriented to regulated waste storage sites. For sediments that do not have a significant toxicity, two alternatives are available for the decision makers: the deposit of sediment in landfills or the valorization of sediments as secondary raw materials (SRM). The SEDIVALD project aimed to test the application of H14 protocol on a set of marine, lake and river sediments where the main regularly pollutants were dosed. The results of these tests showed first a large variability in levels of sediment pollution, which was fairly predictable because of the types of activities for the concerned ports and watersheds. In numerous cases, the H14 protocol was effective for characterizing the level of hazard of sediment and seemed correlated with the levels of pollutants measured. In contrast, other sediments were identified as ecotoxic by the H14 protocol without that the dosed pollution left it supposed. According to classical chemical analyzes, sediments appeared not to be polluted and logically should not have to meet H14 protocol. The origin of the pollution (pesticides or other) must be sought because these hazardous wastes could be used in beach nourishment. The SEDIVALD project has demonstrated the applicability of the H14 protocol to characterize the hazard level of sediments from the ecotoxicological point of view, but it also showed the importance of further investigations to detect contaminants that are not usually taken into account. This is particularly important because the sediments managed in land should be treated by physicochemical and biological processes to enable their valorization as SRM