As DGT results cannot be directly compared to marine water AA-EQS, the general objective of this document is to propose a methodology so that DGT results can be applied in a regulatory context for waterbody quality assessment. Using a pragmatic approach applied to the context of the WFD, this methodology is based on the study of European reports, European technical and scientific guidance documents, publications of network of experts and processing of MONITOOL dataset.
For this purpose, the document is organised in two parts:
- a bibliographic part with a review of the derivation process of EQSs, a description of the differences between DGT and spot sampling based measurements, the proposed methodology for the use of DGT results in a regulatory framework, by comparing DGT results to EQS ;
- a data processing part carried out using MONITOOL datasets in order to adapt EQS marine water in EQSDGT for Cd, Ni and Pb. Moreover, another methodology is proposed, which is to predict the concentrations measured by DGT into its corresponding dissolved concentrations, so they can be directly compared to EQSmarine water.