Together with the Haaglanden Environment Service (ODH), municipalities, and NVWA, the Delftland Water Board conducted extra supervision during the past six months according to the Risk-Based Approach in the Zuidpolder van Delfgauw and Boschpolder. In half of the businesses visited, the water board had to take enforcement action.
Delfland introduced the follow-up to the Area-Based Approach in early 2023: the Risk-Based Approach. With their knowledge of greenhouse stock, growing conditions, and local water quality, the Delfland Water Board determines where to focus in the new approach. The district water board saw that the Zuidpolder van Delfgauw and Boschpolder in Honselersdijk were the most polluted polders. Therefore, they started the Risk-Based Approach in these polders.
Besides common violations, the district water board had its eye on surface water. Besides the Risk-Based Approach, they also implement the agreements from the Emission-free Greenhouse Agreement Framework together with the province, water boards, and horticulture. Each, with its own responsibility and tasks, contributes to achieving (virtually) zero emissions in 2027. The cooperation serves as a catalyst by coordinating actions and putting new initiatives on the agenda. In parallel, the parties developed a perspective from 2028 in which zero emissions is the norm.
Non-working recirculation system: discharge of drain water from rockwool slabs into the soil.
Detection methods Risk-based approach
Supervisors used various detection methods, including mobile devices for measuring conductivity and nitrate (salinity and nutrients), thermal imaging cameras, and conducting surveillance rounds. Using a boat with sensors, "heatmaps" of water quality were created. That map shows where the water quality is worst within a polder. The new detection method using eDNA has also been successfully used to identify the source of pollution.
Half of companies in violation
Based on the risks and findings in the preliminary process, the parties carried out inspections at 30 percent of the companies (18) in both polders. Of this selection, about 50 percent were in violation for leaks, in particular: soil discharges with high values of nitrate and plant protection products.
Penalty fine
If a company commits an offense, immediate enforcement action is taken. The growers are given a short time to end the violation. Failure to do so will result in a penalty payment ranging from €5,000 to a maximum of €15,000 per violation. Even if the violation is now terminated, the penalty remains valid for three years at the company concerned.
In the first six months, Delfland has already imposed 15 penalty fines for violations. Together with the ODH, the council and other parties have observed soil discharges on several occasions. The ODH has also taken enforcement action for these violations several times. For serious violations, a fine is imposed immediately.
Continued Risk-Based Approach
In October, supervisors will start the approach in the Oude Campspolder and Groeneveldsepolder in the municipality of Midden-Delfland and the municipality of Westland. These polders are also among the most polluted polders in the area. The Delfland Water Board is deploying all their detection methods and are paying extra attention to rental greenhouses, greenhouses where some changes have been made, unresolved bottlenecks and crops prone to leaks.
Source: Delfland Water Board