Assessment of sediment quality in the Modular Stepwise Procedure
Sediments can adsorb persistent pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), thereby acting as a long-term source of pollution for surface waters. The compounds can be taken up by aquatic organisms and can accumulate through the food chain. In Switzerland, so far no harmonised method exists for the assessment of sediment quality. Therefore, the Ecotox Centre together with the Federal Office for the Environment has started to work on a new sediment module within the Modular Stepwise Procedure. The aim is to develop the missing methods in order to help the cantonal water protection agencies in assessing the sediment quality and thus ensuring the water quality.
In the first project phase, the Ecotox Centre is developing a harmonized protocol for sediment sampling and pre-treatment. Then it will derive sediment quality criteria for a list of prioritized substances and propose a system for assessing sediment quality that is compatible with the classification of the Modular Stepwise Procedure. As a basis for the prioritization of substances, their presence in Swiss waters and their potential for toxic effects on organisms are used.