Drinking water company Dunea has temporarily ceased drawing water from the Afgedamde Maas River because of elevated pesticide concentrations.

These pesticides are fungicides used by farmers to protect crops from fungal attacks. For the coming weeks, Dunea will source water for purification from the Lek River instead.

The increased use of these antifungal agents is likely due to the heightened risk of mold formation in wet weather. Recent rainfall has washed more pesticides into surface water, leading to the current issue, Dunea explained. This situation is impacting drinking water production.

"This event underscores the need for better protection of drinking water sources against pesticides and pollution from industry and households," the company stated. Dunea highlighted the European Water Framework Directive (WFD), established for this purpose. The Netherlands, however, still falls short of compliance in many areas. The directive, which came into force in 2000, aims for full compliance by 2027.

Dunea serves 1.3 million people in Zuid-Holland. A significant portion of their water comes from the Afgedamde Maas, a tributary of the Maas between Woudrichem and Wijk en Aalburg. Water is extracted there, pre-purified in Bergambacht, and then pumped to the dune area between Monster and Katwijk. After one to two months, the water is pumped up again for further purification before being distributed to taps in The Hague, Leiden, Zoetermeer, and Noordwijk, among other places.

During this pause in water intake, Dunea is conducting maintenance work on the infrastructure near the river branch. "Every disadvantage has an advantage," the water company remarked. Photo by klankbeeld, Wikimedia commons.