Deltares study does not lead to origin of dinoterb

Deltares makes the following recommendations in its report: 

1. Investigate whether past potentially stored dinoterb in the water bottom is released by stirring; 
2. Sample whether dinoterb from possible industrial or human use inflows into the sewage treatment plant; 
3. Additional analysis once dinoterb is found in regular measurements to rule out possible variations in future measurements.  

HHNK is working on these recommendations and remains fully committed to improving water quality.  

Jos Beemsterboer, portfolio holder for integral water management in rural areas at HHNK: "The presence of a banned substance such as dinoterb, years after the substance has no longer been used, makes it clear once again how important it is to continue to work with all parties on water quality. This is a joint task. Whereby the starting point as far as we are concerned must be: what does not come in, does not have to go out. HHNK continues unabated with its approach to the Water Framework Directive (WFD) and is committed to source control, pollution prevention and reduction. In addition, an extra impulse for water quality is in preparation. HHNK will emphatically hold parties accountable for their role in this." 

Big push for clean water 

HHNK's ambition is that in 2027 all the water in its management area should be clean and healthy and meet the WFD standards. This is a tough challenge and not entirely achievable. It is highly dependent on, among other things, nutrient richness, with the natural substances nitrogen and phosphorus. The historical load on the soil also plays a role in the task of achieving the targets. Since 2009, HHNK has been working hard on the joint WFD task to improve water quality. This includes minimizing the impact of agriculture and other human activities on the water and promoting fish migration. Over the past two years there has been a broad political and social awareness that more is needed to achieve the WFD goals in 2027. Therefore, HHNK is preparing an additional package of measures. Among these measures are the reduction of emissions, updating the origin of substances such as nitrogen and phosphorus, reducing indirect discharges and, of course, the deployment of its own instruments. 

About the study  

The study was commissioned by HHNK and conducted by the renowned and independent research and knowledge institute Deltares.The reason for this research was that measurements taken by HHNK showed that dinoterb, a substance banned since 1998, had been found in surface water at various locations. The research included literature research, interviews with involved parties and experts, Map of possible spread routes, analysis of existing dinoterb data. Several organizations contributed knowledge, such as Wageningen Environmental Research, RIVM and Ctgb, CML - Leiden University and the Environmental and Transport Inspectorate. The report was provided with feedback by an external sounding board group consisting of RIVM, ILT and CML. 

Full report available 

You can download the full research report at the bottom of this page.    

About HHNK 

In terms of water quality, HHNK is responsible for regional surface water and sewage treatment. In addition, HHNK works every day to protect the land against water, against flooding and water shortage, for clean and healthy surface water and for safe (navigable) roads. We do this in North Holland above the North Sea Canal: Hollands Noorderkwartier. More information about the clean and healthy water approach can be found at www.hhnk.nl/gezond-water

See also

• Substances in the water
• Frequently asked questions about dinoterb