Pesticides in Dutch drinking water sources

Pesticides are a challenge for the quality of drinking water sources

Pesticides and their metabolites represent a challenge to the quality of drinking water sources because they are one reason why the targets of the Water Framework Directive (WFD) for drinking water sources are not yet within reach. The most recent information about the presence of plant protection products on a national scale dates from March 2019 (the KWR report ‘Gewasbeschermingsmiddelen en hun afbraakproducten in Nederlandse drinkwaterbronnen’) and from 2020 (overall description in the RIVM report ‘Staat Drinkwaterbronnen’). Because the report in the interim evaluation of the Water Framework Directive (WFD) is expected in 2024 and a number of other processes are in progress (such as the elaboration of the De Groot motion, discussion with the Ministry of Agriculture, Nature and Food Quality and the Ministry of Infrastructure and Water Management about amendments to the authorisation policy, discussions with the pesticides sector about measures in addition to the statutory requirements, and internal discussions at Vewin), an up-to-date picture is required of plant protection products in sources used for drinking water supplies. The aim of this study is therefore to update the available information about the present of pesticides in those sources.

Overview based on monitoring data

The aim of this project is to establish a picture of the presence of pesticides and their metabolites in Dutch drinking water sources for the years 2018-2022. That overview is being established on the basis of the RIWA surface water database and data from all drinking water utilities. A distinction is made based on the type of extraction and the position of the monitoring in the water extraction system. In the case of the intake points in surface water, the treatment required due to pesticides is also being identified.

Update of KWR report

This project updates the 2019 KWR report referred to above, ‘Gewasbeschermingsmiddelen en hun afbraakproducten in Nederlandse drinkwaterbronnen’. This factual basis for the challenges faced by drinking water utilities serves as input for discussions with the competent authorities and the pesticides sector. The discussions cover areas such as a possible ban on the use of pesticides in groundwater protection areas, and improving the low-emission use of pesticides in practice.