EU WFD Organic Priority Substances in Water, Suspended Particulate Matter, Sediments, and Biota in the Danube

Abstract

Since its publication in the year 2000, the EU Water Framework Directive (WFD) became the most important legal act for water protection not only within the European Union but also in the Danube River Basin. In its strategy against water pollution, the WFD identifies priority substances (PS). PS are hazardous chemical compounds forming a special threat to the quality of surface waters. The goal is to reduce concentrations of all PS at least below substance-specific environmental quality standards (EQS). EQS are concentration limit values derived on the basis of ecotoxicological substance data and additional information. In the Danube River Basin, the level of contamination of the Danube and its tributaries by PS was investigated within the monitoring activities of the International Commission for the Protection of the Danube River Basin (ICPDR). Especially the results of ICPDR’s research expeditions in 2001 and 2007, the Joint Danube Surveys, revealed the exposure situation for PS in different aquatic matrices. For the subgroup of organic PS, widespread pollution problems with partial exceedance of the respective water EQS were found for nonylphenol, a decomposition product of surfactants, the plasticizer di(2-ethylhexyl) phthalate, and tributyltin compounds, formerly used in antifouling paints for ships. The mostly banned pesticide atrazine could also be found in many water samples. For all other PS, only local problems were identified or they have not been detected at all. The results for suspended particulate matter, sediment, and biota support the findings above.