News » 09.07.2025 - Precise tracing of pollution in surface water discussed at Water Day
On Tuesday afternoon during Water Day, Stijn van Boxmeer explained how the Delfland Water Board monitors water quality in the Netherlands. As he himself admitted at the end of his presentation, his message wasn't exactly "uplifting" for growers. Or perhaps it's better framed as a call for greater awareness?
Van Boxmeer stressed that leaks and/or discharges not only harm water quality but also damage the public image of the horticultural sector. "And that's something we simply cannot afford," he said. The consequences, he warned, could be significant.
Stijn van Boxmeer, Delfland Water Board
Surface water monitoring
Each month, the Delfland Water Board carries out inspections across all 26 regions featuring greenhouses in its district. These checks include monitoring for no fewer than 241 crop protection substances. You might think, "There aren't that many products in use anymore,"and that's true, but the inspections also target unauthorized substances.
The graphs presented by Stijn van Boxmeer reveal that improvements in water quality have stalled. His data clearly highlights which regions are performing well and which are falling behind, making the situation highly transparent.
In regions that show poor results, further investigations follow. Small drone boats are deployed to examine the surface water in local ditches, allowing the source of contamination to be pinpointed with precision. "And before you know it, the NVWA is at your doorstep," Stijn warned.
"Please do everything you can to prevent this. The stakes are too high to ignore. We've already seen cases where growers have faced operational restrictions, crop protection products are being reassessed earlier, and phased out more quickly. Nutrient use may also become more tightly regulated."
He acknowledged that the sector faces a daunting challenge in meeting the new Water Framework Directive targets by the end of 2027. "Whether it seems realistic or not, it is the reality. So growers, take action. Question yourself. Question whether you might unknowingly be discharging. Do the leakage check. Work with a water coach," he urged in closing.
Arthur van den Berg of Glastuinbouw Nederland
Water coach
Arthur van den Berg of Glastuinbouw Nederland wrapped up the plenary session of Water Day with a presentation on the water coach initiative. He emphasized that in order to achieve (virtually) closed-loop greenhouse systems, the last remaining leakage flows must be addressed. Even a small leak can result in exceeding environmental thresholds.
To move toward (near) zero-emission horticulture, it's essential for growers to have a clear understanding of all water flows within their operation. That's where the watercoach comes in: helping growers identify and map out these flows, spot weak points, and take targeted action.
With this hands-on guidance, growers are better equipped to meet environmental standards and contribute to a cleaner, more sustainable sector.
Source: www.floraldaily.com
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