Contamination of surface waters with organic micro pollutants poses a challenge to water protection. The FOEN-project “micropollutants from diffuse sources” is dealing with compounds which enter surface waters not via points sources, such as waste water treatment plants, but rather via diverse diffuse entry paths. Such entries mainly stem from agriculture, material protection in urban areas or gardens. Thus, the project focuses mainly on compound groups such as plant protection agents, biocides or veterinary pharmaceuticals.
The department of environmental chemistry works on several aspects of the above described project. The goals of the works within the department are to give an overview on the pollution situation in Switzerland caused by diffuse inputs as well as to develop a concept to assess micropollutants from diffuse sources to Swiss surface waters. To do so, a procedure was developed to prioritize and categorize the more than 500 plant protection agents and biocides in to “relevant for surface waters” and “surface water irrelevant” compounds. Based on this prioritization a list of Swiss-specific compounds was compiled which are recommended for future monitoring studies by cantonal authorities. For the selected compounds ecotoxicologycally based environmental quality standards (EQS) according to European guidelines are derived by the Ökotoxzentrum. Besides the substance selection the concept includes a sampling strategy which should be feasible in practice and yields sound data. In the last step an evaluation scale is developed to judge the surface water quality (from bad to very good) based on the measurements and the EQS.
The concept to assess micropollutants from diffuse sources will be together with the concept for communal waste water, the basis for a guideline by the federal office of environment (FOEN).
The work is also supported by a group of stakeholders from cantons, industry and further federal offices.
The work is in close connection to the following projects: „ Exposure and Fate of Insecticides and Fungicides in Swiss Surface Waters “ as well as „NAWA SPEZ Screening plant protection products an biocides“ and in close cooperation/co-work with the Ökotoxzentrum der Eawag/EPFL.