This RIWA-Rijn annual report describes the water quality of the Dutch part of the Rhine river basin in 2023 at the border crossing at Lobith and at the abstraction points at Nieuwegein, Nieuwersluis and Andijk. We compare the measured values with the target values set out in the European River Memorandum (ERM) and give specific attention to substances that exceed these target values. We also report on the development of the required level of treatment for drinking water production (WFD Article 7.3) at these locations by means of the treatment challenge index. In addition, at Lobith we assess the emission reductions set as objectives by the Rhine Ministers’ Conference in 2020 in the ICBR Action Programme 2040.
It has now been three years since we were first informed about—and drew attention to—the more or less unlimited discharge of PFAS in treated industrial wastewater in the Rhine river basin due to the absence of emission limit values for PFAS in discharge permits. This practice is remarkable, particularly given that the revised Drinking Water Directive now sets limit values for these same PFAS—limits that the Dutch National Institute for Public Health and the Environment (RIVM) considers insufficiently stringent to protect drinking water quality.
We also once again scrutinize lithium, partly in response to exceedances of indicative environmental risk thresholds for lithium in the surface waters of the Rhine and the Rhine river basin. Unfortunately, this year as well we conclude that a large number of substances exceed the ERM target values, preventing drinking water companies from producing clean and healthy drinking water using simple natural treatment methods. The objective of WFD Article 7.3 (reducing the required level of treatment) is therefore not being achieved.
In particular, we observe increasing loads of substances originating from urban wastewater, such as pharmaceutical residues. This runs counter to the 30% reduction target set by the Rhine Ministers’ Conference in 2020. To improve this situation, it is essential that industrial discharge permits include emission limit values that protect the river’s drinking water function, and that progress is accelerated in upgrading wastewater treatment plants by adding a fourth treatment stage.
Recently, we expanded our monitoring with non-target screening (NTS), enabling us to monitor the presence of both known and unknown substances. The Water Laboratory in Haarlem, which carries out this screening on our behalf, provides an explanation in this annual report of how this process works.