Abstract

The RIVM has developed a stepwise method that can be used by groundwater managers to take into account the quality of groundwater intended for human consumption during the risk assessment and status assessment of groundwater bodies.
The Water Framework Directive (WFD) requires that each Member State of the EU provides such information to the European Commission at 6-year intervals. The first river basin management plans of the Netherlands contained incomplete information on the quality of the groundwater intended for human consumption despite this being a requirement of the report. The root of the problem at that time was the uncertainty by the groundwater managers on how to integrate such information into both the risk assessment and status assessment. Two case studies form the basis of the stepwise plan.
To dissipate any remaining uncertainties, the RIVM has described how the risk assessment has a cyclic relationship with the status assessment. The risk assessment can lead to new or modified monitoring approaches to determine whether potential problematic substances are present. The monitoring data form the basis for environmental quality standards, which can then be used to assess the status of groundwater bodies. Based on this assessment against the established norms, measures can be taken when necessary, and the effect of these measures can then be evaluated in the next risk assessment.
The method developed by the RIVM can be used to select substances that form a risk for groundwater intended for human consumption and which should be approached on a groundwater body scale. The results of the two cases that have been performed reveal that the stepwise method identifies substances for which no national or European environmental quality standard currently exists.
A similar method can be developed for the other relevant functions of groundwater, namely surface water- and groundwater-dependent terrestrial ecosystems.