In the Netherlands, many different pesticides are detected in surface waters. Some of these compounds exceed the water quality standards. An inventory of RIVMNational Institute for Public Health and the Environment and the Dutch Ministry for Infrastructure and the Environment on how other countries deal with pesticides and water quality shows that other countries face similar problems, but the substances may differ depending on the finding location.
At present, only a limited number of pesticides are regulated at the European level under the Water Framework Directive. Harmonised water quality standards only apply to these “priority” substances. For other substances, each Member State sets national water quality standards themselves. These standards differ in each Member State, according to the RIVMNational Institute for Public Health and the Environment study.
It is recommended to coordinate the derivation of water quality standards for pesticides in Europe. An option could be to set mutually approved standards already during the European process of pesticide authorisation.
The present research shows that for some pesticides, revision of the Dutch water quality standards is needed to draw conclusions. A revision based on the latest methodology and using all available data may show that problems are less serious than assumed now. However, there are also substances that are not identified as problematic but possibly will be if a new standard is derived.
The English management summary is available as download in right-hand column.