Expert report: Strategy for assessing sediment quality in Switzerland
Sediments play a crucial role for surface water quality. However, until now there has been no uniform method for the cantons to monitor sediment quality. On behalf of the Federal Office for the Environment, experts from the Ecotox Centre have drawn up a proposal on how sediments in Switzerland should be sampled, processed and assessed.
One of the aims of the Swiss Water Protection Ordinance is to ensure that sediments do not contain persistent chemicals or accumulate substances that have a harmful effect on organisms. This is because these compounds can deteriorate surface water quality. However, Switzerland still lacks a uniform strategy for the assessment of sediment quality. The Ecotox Centre has now developed such a strategy during 6 years in exchange with the cantonal water protection agencies, the VSA and experts from several research institutions.
In the expert report that has just been published, a robust strategy for monitoring and assessing the quality of sediments on the basis of their chemical status is presented. The strategy includes procedures for sampling and sample pre-treatment for chemical analysis. In addition, it contains a substance list proposed for monitoring campaigns, sediment quality criteria (EQSsed) for these pollutants, and a multi-level assessment system that is based on the modular stepwise procedure. The strategy is designed for routine use and builds on methods already used in the cantons.