Groundwater Atlas for pesticides launched

Such a current and public overview of the presence of pesticides in groundwater is unique in the context of our neighbouring countries. There is a great deal of societal and scientific interest in pesticides and their effects, and one regularly hears calls for increased ‘pesticidovigilence’: alertness to the use and effects of pesticides, such as recently in Science magazine. The Groundwater Atlas will help in cases of early detection of signs of undesirable effects, despite all the precautionary measures in the authorisation procedure.

The Groundwater Atlas provides a picture of which pesticides, biocides and their metabolites are present, where they are, and in what concentrations. The measurement data in the atlas come from monitoring wells of the drinking water companies and from the provinces. They cover the period from 1990 until the present. Keeping the picture updated will require further agreements and automation of the information interchange on the basis of the original data. Although large quantities of data are included, additional data from the provincial measurement networks could also be included, and a tighter quality control is needed regarding the exact location and depth of the monitoring points.

Earlier this year, a KWR report was published showing that the pesticide contamination of groundwater in the Netherlands is widespread, including outside of the groundwater protection areas. A current and accessible overview of these data can be of assistance to a number of stakeholders – think for example of the ministries of Infrastructure and the Environment and of Economic Affairs, which are responsible for national policy on plant protection products, biocides and groundwater; the CTGB as the approvals authority; the provinces as groundwater managers; and the users of groundwater such as the drinking water companies and breweries.

At this moment a project is underway, on a commission from the ministries of Economic Affairs and of Infrastructure and the Environment, to study how the data from the Groundwater Atlas might be incorporated into the more detailed levels of the authorisation evaluation. In this case the spatial density of the data is important since, as in the case of surface water data, the connection has first to be shown between the use of a pesticide on a cultivation and its presence in groundwater, before an existing product authorisation can be affected. In this regard, knowledge of the relevant abstraction area and the stream channels is also important.