van Leerdam RC, Janssen PJCM, van der Aa NGFM, Versteegh JFM
RIVM Report 2018-0080
To ensure that drinking water remains clean, water managers and drinking water companies monitor whether 'new' pollutants are present in the surface water. These substances are called 'new' because they are newly found contaminants for which there is no legal standard yet. To ensure that these substances are detected in surface water at an early stage, it is monitored if the concentration exceeds the signalling value of 0.1 micrograms per litre. If this is the case, the substance's potential health risks are further investigated. From 2013 to 2015, 42 substances appear to have exceeded this signalling value in surface water used for the drinking water supply. Research by the RIVM shows that they do not pose a health risk via drinking water.
The 42 researched substances include pesticides, medicine residues, sweeteners and industrial substances. They have ended up in surface water via discharges from industry, the sewage treatment plant or via agriculture. Most of these substances are not completely removed with a simple surface water purification process.
In order to identify potential health risks, the RIVM has set up 'provisional guideline values for drinking water' for these new substances - if they did not already exist. These are the concentrations at which the water is still safe to drink. These target values are not laid down by law but serve as a health guideline. In this study, the provisional guideline values were compared with the highest concentrations of the 42 substances found in the surface water sources for drinking water. For each substance, the measured concentration remained well below the provisional guideline value; for most substances with more than a factor of 10.
This risk assessment was carried out for the Ministry of Infrastructure and Water Management (IenW) to support the assessment of the targets in the Water Framework Directive (WFD).
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