Water company stops extracting drinking water from Maas river over pesticides

Drinking water company, Dunea has temporarily stopped taking water from the Afgedamde Maas River because it contains too high concentrations of pesticides. These are fungicides, agents that farmers use to prevent fungi from attacking their crops. In the coming weeks, Dunea will take water for further purification from another river, the Lek.

The antifungal agents have probably been used more often lately, as there is more risk of mold formation in wet weather. The rainfall of the past period has also caused pesticides to be washed into the surface water, Dunea explains. That now has consequences for drinking water production.

"The event confirms the need for better protection of drinking water sources against pesticides and pollution from industry and households," the company stated. Dunea pointed out that the European Water Framework Directive (WFD) was created for this purpose. In most places, the Netherlands still does not comply with this directive, which came into force in 2000. The goal is for this to comply with the directive in all places by 2027.

The drinking water company serves 1.3 million people in Zuid-Holland. A significant portion of the water comes from the Afgedamde Maas, a tributary of the Maas that flows between Woudrichem and Wijk en Aalburg. The water is taken in there. Further, in Bergambacht, it is pre-purified and pumped to the dune area between Monster and Katwijk. There, it is pumped up again after a month or two, after which more purification steps are performed. Ultimately, the purified Maas water comes out of the tap in The Hague, Leiden, Zoetermeer, and Noordwijk, among other places.

Dunea is immediately carrying out maintenance work on the infrastructure near the river branch, as they now have time to do so due to the intake stops. "Every disadvantage has an advantage," the water company said.