Peces y sedimentos: Dos matrices para la vigilancia de la contaminacion por sustancias peligrosas en la cuenca del rio Ebro

Abstract

According to European Directive 76/464/EEC, Member States must take appropriate action to eliminate pollution of waters by the dangerous substances included in List I. Two basic approaches will achieve this objective, i.e. an emission limit value (ELV) approach, and a water quality objective (WQO) based approach. The ELV approach requires that all discharges into waters including substances in List I need authorisation. Thus, emission standardsfor substances in List I must be laid down. The WQO-based approach ensures that the area affected by discharges complies with fixed quality objectives for water: sediments and biota. The Confederacion Hidrográfica del Ebro (CHE) has implemented the Directive by limiting all discharges including List I compounds. In discharge authorisations by CHE, emission limits are fixed. In addition, CHE has established a "DangerousSubstances Monitoring Network", to test the compliance of waters, sediments and biota with quality standards (i.e. the WQO-based aproach), downstream of every point source. The network was standardised in 1997. Today, there are nine sampling stations, and samples are analysed for the following pollutants: mercury, cadmium; HCH and isomers; DDT and metabolites; carbon tetrachloride; pentachlorophenol; aldrin, dieldrin, endrin and isodrin; hexachlorobenzene; hexachlorobutadiene; chloroform; 1,2- dichloroethane (EDC); trichloroethylene (TRI); perchloroethylene (PER); and trichlorobenzene (TCB). These substances are monitored in water; sediments and biota. This article exposes the criteria applied to design the Dangerous Substances Monitoring Network, with an aim to informing about proper implementation of Directive 76/464/EC. © Asociación Española de Limnologia.