(organic trace substances)
The recommendation for the investigation and assessment of micropollutants will consist of 2 documents. Not all substances are regulated in the Waters Protection Ordinance (WPO) and the toxicity of mixtures of different substances is also not taken into account. In addition to the intercantonal recommendation for substances with numerical requirements in Annex 2 of the WPO, a recommendation for assessing the ecotoxicity of organic trace substances will therefore be developed.
Since April 2020, numerical requirements for organic trace compounds have been included in the WPO. In the intercantonal recommendation “Organic micropollutants – numerical requirements Annex 2 WPO”, instructions were drawn up on the procedure for collecting and assessing the organic trace substances explicitly regulated in Annex 2.
The recommendation was published by Lab’eaux, the competence network of cantonal water protection and environmental protection laboratories, and the VSA. The report was drawn up in close cooperation with an advisory group of experts from the cantonal water protection agencies, Eawag, the Ecotox Center and the FOEN.
The method is based on the following documents:
- Assessment concept for substances from municipal WWTPs
- Assessment concept for substances from diffuse sources
Note: This publication is not a federal implementation aid, but an intercantonal recommendation.
Recorded parameters:
Pharmaceutical residues, biocides, pesticides and other organic trace compounds.
Evaluation:
Comparison of concentrations with numerical requirements that must be met at all times and the requirements that must not be exceeded over a period of two weeks (persistent pollution).
Legal assessment: Requirements met / not met.
A large number of organic trace compounds occur in water bodies. However, only substances that have shown many exceedances in the past are regulated in the WPO. The toxicity of mixtures of different substances is also not taken into account in the WPO. In addition to the intercantonal recommendation for substances with numerical requirements in Annex 2 of the WPO, a recommendation for assessing the ecotoxicity of organic trace substances is therefore being developed.
The method is based on the following documents:
- Assessment concept for substances from municipal WWTPs
- Assessment concept for substances from diffuse sources
- Artikel Aqua & Gas: Junghans, M., Kunz, P., & Werner, I. (2013). Toxizität von Mischungen. Aktuelle, praxisorientierte Ansätze für die Beurteilung von Gewässerproben. Aqua & Gas, 93(5), 54-61.
Recorded parameters:
All organic trace compounds (micropollutants) for which robust ecotoxicological quality criteria are available. Mixture toxicity for vertebrates, invertebrates and plants.
Assessment:
Comparison of concentrations with chronic and acute quality criteria (CQC and AQC).
Evaluation in 5 categories.