2021

Interview Joyce Nelissen (WML) on the prosulfocarb incident

What did the prosulfocarb incident mean for drinking water company WML? WML director Joyce Nelissen: "First, it's important to state that if we're talking about water quality, we see an increase of all sorts of new substances in the Meuse. This demands not only increasing alertness, but also cross-border cooperation. After all, the Meuse starts in France.

This means coordination with all our partners along the Meuse to ensure that we try to manage the quality of the Meuse as well as possible. This is problematic due to the differing interests that multiple stakeholders have and the ways in which they think they ought to use the Meuse. Prosulfocarb is an example of this. It's a substance that you absolutely do not want to come across in your water."

Managerial impression

In 2019, the incident with this herbicide led to major abstraction interruptions. "We had to suspend the abstraction of Meuse water for so long that we almost switched over to the abstraction of groundwater. This is a drastic measure that was avoided just in time.

If we must stop the abstraction of Meuse water, we first use water from our stock basin. Depending on the weather, we can maintain production in the summer for 1½ months and in the winter for 2½ months. But then of course the basin needs to be refilled from the Meuse.

I still remember that just a couple of days before we definitely had to switch to our groundwater wells, we heard what the issue was. There was an untraced discharge of prosulfocarb, somewhere in Wallonia. Only when it became clear where the polluter was situated, we could call a halt to it.

To this end, we contacted the Network Development Director of Rijkswaterstaat Zuid-Nederland, Karin Weustink. Because Rijkswaterstaat, the water manager of the Meuse, was facing the same problem."

Round the table with SWP

"We then went together to the offices of the Service Public de Wallonie (SPW) to raise the problem there. We sat at the table with the management team to discuss the seriousness of this case. We also expressed our desire and expectation of SPW would go into action.

To be honest, the reaction to this was disappointing. From SPW's perspective there wasn't a problem, because they apply different standards from ours. In other words: the polluter was still meeting the standard there. It was also strange to consider that WML and SPW are only a few kilometres apart geographically, but nonetheless work with completely different standards and legislation. Our Wallonian colleagues therefore enforce different standards from ours.

We then steered the discussion about the different standards towards making practical working agreements, and we emphasised the importance of cross-border cooperation for the future. Our response to SPW was clear: if there's no problem in Wallonia, but there is downstream, then we need to solve it together.

This was the starting point for the development of an international protocol with which cross-border incidents on the Meuse can be tracked down quicker in the future. RIWA-Meuse drafted this."

Tracking protocol proves successful

"When high concentrations of prosulfocarb were found again in the Meuse in 2021, there was no more discussion about standardisation. Thanks to the protocol and the cooperation we had built up between 2019 and 2021, we were able to track the culprit quicker. In 2021, the discharge proved to originate from a waste-processing company that processes drums with plant protection products. SPW then initiated an enforcement procedure against the company. I'm happy that we see the fruits of our cooperation in this tracking protocol."