The Delfland Water Board and the Netherlands Food and Consumer Product Safety Authority (NVWA) have identified the suspected culprit behind the discharge of the banned plant protection product dichlorvos. This substance was detected during a routine monitoring round in December 2023. The Hoogheemraadschap found a significant excess—6,000 times the legal limit—of the plant protection product in surface water within the municipality of Westland.
Following this discovery, authorities investigated which cultivation companies were located upstream from the measuring point. The NVWA and Delfland then visited these farms to identify the source or sources of the illegal discharge. One company admitted responsibility for using the banned substance, and additional evidence was collected to support this admission.
The discovery of the culprit was made early this year, and the Delfland Water Board has now released a statement on the matter.
Tracing the discharge
After investigating the company, authorities traced and terminated the suspected route of discharge from the greenhouse to the surface water. In the recent period, repeated measurements in the area have shown no new violations of pesticide standards. Delfland continues to monitor water quality on a monthly basis.
The NVWA and Delfland have drawn up official reports and submitted them to the Public Prosecutor's Office.
Concern raised
Water board member Stijn van Boxmeer commented, "Discharges like this are very concerning, especially since they involve a toxic plant protection product that has been banned for years. Tracing offenders is complex due to the extensive greenhouse horticulture in our region, which means there are potentially many culprits when we detect a violation. I am therefore very pleased with the strong cooperation between Delfland and the NVWA, which enabled us to identify the suspected perpetrator. I trust that the polluter will face a punishment that reflects the severity of this pollution."
Van Boxmeer continued, "The quality of surface water in and around greenhouse horticulture needs to improve. While many growers adhere to the rules, unfortunately, there are still some who do not. The high concentrations of pollutants discharged into surrounding ditches kill fish and insects that live there. Moreover, the requirements set by EU framework directives are not being met. This underscores the importance of even closer cooperation among the involved organizations."
The Delfland Water Board monitors surface water quality through regular measurement rounds and has noted the presence of substances in the water that do not belong there. It is important to remember that before these substances enter the water, an entire chain is involved in their development and use, including producers, intermediaries, and greenhouse horticulture as the end users. The Delfland Water Board reminds everyone in this chain of their responsibilities.
Source: Delfland Water Board