A collective water treatment plant for greenhouses was opened in Hoek van Holland on Wednesday afternoon. During the official opening, the greenhouse horticulture sector received compliments. After all, it is far from just things going 'wrong', although you would sometimes think so if you read the news about crop protection products, among other things.
Today, also in Hoek van Holland, the sector is showing that growers are willing to take steps. Then, just down the road, the Beyond Experience opens. Later, the opening of that initiative by chrysanthemum grower Beyond Chrysanthemum and partners will be discussed.
95% purification efficiency
On Wednesday afternoon, the partners involved in the realization of a PACAS installation, at the sewage treatment plant Nieuwe Waterweg, met. The installation will ensure that more than 300 horticulturists, representing more than 1,000 hectares, have their water purified of crop protection agents centrally. For example, gardeners are still joining after mergers. The sector cooperated with the Delfland Water Board, three municipalities, and the province of South Holland, among others.
The project took quite some doing. Bart van Meurs spoke as project leader on behalf of the growers. He spoke about how the first steps were taken as early as 2013, in response to legislation demanding 95% purification efficiency for crop protection products.
The initial business strategy was conceived in 2016, with a key focus on securing sufficient irrigation water to facilitate the construction of a plant. This was crucial because the water from the greenhouse, which is not separately identified, merges with a collective pool of wastewater from residential areas and various commercial operations.
Bart van Meurs highlighted figures in his presentation
25% horticultural water
Ultimately, 25% of 'horticultural water' arrives at the Hoek van Holland sewage treatment plant. "That's a lot by Dutch standards," Bart indicated. Thanks to the initiative from greenhouse horticulture, the remaining 75% is also purified of medicine residues, among other things.
At the wastewater treatment plant on the premises of the Delfland Water Board in Hoek van Holland, an extra treatment step has been created so that crop protection agents are removed and the wastewater becomes even cleaner. An additional advantage is that medicine residues are also filtered out of the water. It is a big step towards cleaner surface water.
Werner Krijger, project manager on behalf of the Delfland Water Board, explained by that a stricter bromate standard has delayed a project in Vlaardingen even more. Purifying a swimming lake on top of the Blankenburgtracé from blue-green algae is therefore still some time away.
Pressure pipe
Bart has been involved in the project since 2019. In 2020, the Water Purification Cooperative Westland was set up. This includes growers of various kinds, large and small, soil and substrate cultivation, ornamental plants, and vegetables. The more growers get involved, the more beneficial it is, including financially.
A significant hurdle for the project, as highlighted in Werner Krijger's presentation, the project leader at the Delfland Water Board, was the unexpected implementation of a much stricter bromate standard in 2021. Until that point, the project had been adhering to a Swiss standard, as Werner pointed out. However, the new regulation is 50 times more stringent. This change has made the use of ozone for purification unfeasible. Consequently, the project is revisiting the use of activated charcoal for purification. This method involves using powdered charcoal, which aids the bacteria in 'eating' the wastewater clean, effectively removing pesticides and medicinal residues and resulting in cleaner treated wastewater.
The project officially opened on 27 November, yet it remains unfinished. A crucial component still under development is a pressure pipeline intended to transport water from growers in De Lier to Hoek van Holland. This pipeline is expected to be operational by 2027. Despite this, Bart emphasized that growers are not simply waiting idly. They have proactively implemented nine measures on their own accord to enhance water quality.
Janwillem de Jong on behalf of Mobilis Croonwolter&dros is not cycling himself but is looking forward to the finish of the project after a final mountain stage
Compliments
After Janwillem de Jong on behalf of contractor Mobilis Croonwolter&dros has also taken the audience in the Keringhuis next to the Maeslantkering through the construction process, it is time to board the bus. Five minutes later, right next to a radish greenhouse, the group arrives at the sewage treatment plant. It houses two identical, so-called PACAS plants. This ensures that purification can always continue, even if one of the two plants needs maintenance.
South Holland deputy Arne Weverling, Westland municipality alderman Michiel Ferwerda, board member of the Water Purification Cooperative Martin Boers, and high water board member Robert Tieman all spoke briefly just before the official push of the button. Fine words about the greenhouse sector follow. Compliments too, for the decisiveness of a sector that is not always seen in a positive light.
It could all be more positive, Alderman Ferwerda stressed. The sector is helping the entire region with this initiative. Thanks to the PACAS plant, the Hoek van Holland treatment plant is also well on its way to meeting new stringent European treatment standards.
Arne Weverling, member of the Provincial Executive of South Holland, Michiel Ferwerda, alderman of the Municipality of Westland, Martin Boers, board member Waterzuiveringscoöperatie Westland, and Robert Tieman, Hoogheemraadschap van Delfland
Growers pay
The growers affiliated with Waterzuiveringscoöperatie Westland will pay the costs of this collective purification, supplemented by subsidies from the Westland municipality, among others. Discussions are still ongoing with the Ministry of I&W and the Province about a possible subsidy contribution.
Jacco Vooijs, chairman of Waterzuiveringscoöperatie Westland: "Treating waste water is not an everyday task for an entrepreneur. We are proud of the realization of the joint PACAS installation together with Delfland, but also of the fact that we managed to unite so many horticulturists in this collective."
Alternative to collective
There are no similar initiatives in the Netherlands. Guus Meis, Policy Specialist Water & Environment at Glastuinbouw Nederland, does point to the Bommelerwaard, where the greenhouse horticulture sector also purifies collectively, but on a smaller scale, and in a different way. The wastewater from the greenhouses enters here separately from regular wastewater. That makes it different. There are no places in the Netherlands where the percentage of wastewater from greenhouse horticulture at a sewage treatment plant is high enough to make an initiative from the sector itself profitable.
In the Westland/Delfland region, not all growers are connected. That doesn't mean they don't have to comply with the treatment rules themselves, or don't take steps themselves. Guus explains that there is a list of purification techniques from which growers can choose individually. This is the BZG list.
The design of the Collective Purification has come about in a Construction Team with Sweco, Combination Mobilis Croon Wolter & Dros, RWB, and ABB. Construction was carried out by Combination Mobilis Croon Wolter & Dros with RWB as subcontractor.
Application for the Westland collective purification can be made by emailing this address [email protected]. More information on this can be found on the webpage of Glastuinbouw Nederland here.