Elevated concentrations of Dimethenamide in the Rhine near Bad Godesberg

On 23 May, the Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen (LANUV) reported elevated concentrations of the plant protection products Dimethenamide and Metolachlor in the Rhine near Bad Godesberg. Since 17 May 2024, these elevated values have been observed at Rhine kilometre 647.5 on the left bank. No abnormalities were initially found on the right bank, at Bad Honnef (Rhine-kilometre 640).  

The observations were transmitted through the International Warning and Alarm system of the ICPR as information and search reports. Traces of both substances were also found in Worms, Rhineland-Palatinate.   A previous report (number 4) reported that markedly elevated concentrations have since been measured on both banks near Bad Honnef and Bad Godesberg. The values rose to 0.43 μg/L for Dimethenamide and 0.14 μg/L for Metolachlor in Bad Godesberg, and 0.22 μg/L for Dimethenamide and 0.11 μg/L for Metolachlor in Bad Honnef.

In its most recent report, LANUV reports that pollution waves have arrived unabated in Kleve-Bimmen and Lobith, indicating that the pollution has moved downstream and is now affecting these areas as well.

These increased concentrations of Dimethenamide and Metolachlor represent a worrying development for the water quality of the Rhine. RIWA-Rijn is closely monitoring this situation and working with relevant agencies to assess the impact and take appropriate measures to safeguard water quality. It is essential to identify and address the sources of this contamination to prevent recurrence and protect the Rhine as a source of our drinking water.

SETAC Europe 34th Annual Meeting: the importance of facts

From 5 to 9 May 2024, the 34th annual meeting of SETAC Europe took place in Seville, Spain. This year’s theme was “Science-Based Solutions in Times of Crisis: Integrating Science and Policy for Environmental Challenges”. This meeting attracted more than 3,000 participants and offered a wide range of interesting sessions and poster presentations.  

With a total of 500 presentations and 2,300 posters, there was something for everyone to discover. One notable contribution came from RIWA-Rijn, which presented a poster entitled “Watch on the Rhine – RIWA-Rijn – Turning River Water Quality Data into a River of Quality Water Data”. This presentation fell under the theme “Science Communication: Reaching Outside of the Scientific Bubble” and focused on how data from the Rhine is being used to provide insight into water quality.

RIWA-Rhine’s poster showed how the concentrations are compared with target values from the European River Memorandum (ERM) and how the data have been used to determine the treatment task index and evaluate the 30% reduction target. The main message was that decision-making should be based on facts. This highlights the importance of collecting, interpreting, visualising and sharing quality data, especially when it comes to drinking water sources.

Another interesting contribution at the SETAC meeting was the presentation of the CREED method. This method provides a framework for systematically and transparently assessing both the reliability and relevance of environmental exposure datasets. The meeting demonstrated that a RIWA-Rijn dataset on the presence of hexa(methoxymethyl)melamine (HMMM) in Dutch surface waters, after completing missing information, was assessed as ‘usable without limitations’ at the silver level for reliability.

The SETAC Europe 34th Annual Meeting provided a platform for valuable knowledge exchange and collaboration between scientists and policy makers. The event highlighted the crucial role of scientific data in environmental decision-making and the importance of effective communication of these data to a wider audience.