Verhoeve News 2025

Soil remediation Elnor Haacht commissioned by OVAM

Published Oct. 30, 2025

A soil remediation project at Haacht was commissioned by OVAM. Electric motors have been manufactured on the site since 1916. Contamination with VOCl occurs in the solid part of the soil and groundwater. This contamination is due to the former use of degreasing baths.

Implementation of soil remediation

The soil remediation was carried out as part of demolition and new construction of the existing warehouses. Here, the production processes continued on site, and close cooperation with the general contractor of the demolition/new construction project was necessary.

At the level of the source plot, soil remediation was performed by in-situ bioremediation of the core zone. Bioremediation is the process of using microorganisms to break down contamination. Prior to in-situ bioremediation, an intensive soil air campaign was carried out. Carbon source injection to stimulate the microorganisms was carried out through direct-push injections over an area of about 1,500 m². Injections were made in different zones over an injection trajectory between 2.0 m-mv and 12.0 m-mv.

Results and follow-up

After completion of the injections and during the construction of the new warehouse, about 10 fixed injection filters were installed as backup. Meanwhile, the 1st monitoring results are known, which show a clear decrease in contamination. No more violations of the clean-up values are observed. The total duration of the soil remediation work is estimated at five years.

Contact

For more information, contact project engineer Michaela Soeters (+32(0)471812351 or m.soeter s@verhoevemw.com) or project manager Wil Brabers (+32(0)473174269 or w.brabers@verhoevemw.com).

Verhoeve News 2025

Successful Forfait remediation in Destelbergen

Published Oct. 31, 2025

After an extensive screening of available soil contamination files, Verhoeve signed a contract in 2017 to perform a forfait remediation in Destelbergen. In this type of contract, Verhoeve takes over the entire contamination problem from the client (from design to final delivery) in order to unburden the client as much as possible.

VOCI contamination in soil and groundwater.

This particular case involved VOCl contamination, both in soil and groundwater, spread over an area of approximately 6,000 m2 and to a depth of 13 m-mv. Initially, 2 shallow core zones were excavated. This was followed by deeper excavation (with formwork) to 6 m-mv. In total, about 2,900 tons of soil were removed. To be able to carry out the deep excavation dry, several deep wells were installed, including a downstream water treatment system of 50 m3/hour.

After the various excavations, a switch was made to stimulated biodegradation to further address the VOCl contamination in the groundwater. For this purpose, a total of 392 direct-push injections were carried out from 1m -mv to max 13 m-mv at the level of the different source zones and the plume zone. As a carbon source to stimulate the microorganisms, our in-house developed V-CS® was applied which was diluted 1:1 with water. A total of 155 m3 of injection solution was injected into the soil.

Redevelopment

After the remediation work was completed, the entire area was intensively sampled to monitor the evolution of the degradation. This was always found to be good so there was no need to carry out additional injections. In the meantime (from 2020), the plot was completely redeveloped. From the beginning, the remediation design was handled in such a way that soil remediation and redevelopment could go well together.

Contact

If you have any questions about this project, or if you would like to talk to us about a similar approach, please contact project manager Jonas Wittocx (+32(0)483270932 or j.wittocx@ver hoevemw.com) or project manager Wil Brabers (+32(0)473174269 or w.brabers@verhoevemw.com).

Verhoeve News 2025

Verhoeve performs function-oriented soil remediation for construction of Rafelder solar farm in Etten

Published Sept. 29, 2025

Construction of solar parks on former landfills is seen as a sustainable solution. Many times landfills lie aimless and are often used as nothing more than pasture. Remediating the landfill is not economically feasible. Nor, except for a few landfills, do they pose a threat to the environment. The top of the landfill often already has a sufficiently thick cover of soil. Groundwater quality is monitored periodically. More and more solar parks are springing up on former landfills in the Netherlands.

Situation Rafelder (Etten, Achterhoek).

The area has historically been home to brick factories that mined clay in the area as material for bricks and roof tiles. The resulting "clay holes" were then filled with waste from the region. This is also how the former Rafelder landfill site came into existence.

Soil testing revealed that in addition to landfill material, the soil contains heavy metals and PAH, creating a potential contact risk in the current situation. The covering layer on site was found to be insufficiently thick. Ensuring an adequate covering layer is then the task. What could be better than to combine this with the construction of a solar park.

Solar farm construction, Verhoeve expertise

Verhoeve was asked by the client to contribute its expertise right from the design phase. This resulted in the execution of a function-oriented soil remediation.

Client had high requirements for the slope and finish heights of the capping layer. And no grain of landfill material was allowed to be diverted from the site, well re-suspended.

Verhoeve recorded the baseline situation of the site and entered this data into a 3D model. From the computational model came the optimal earth-moving model, suitable as input for the earth-moving machinery that performed the work.

After setting aside the existing cover layer, the landfill material was rearranged. After rearrangement, the cable trenches were dug and backfilled with sand. Afterwards, the capping layer was set back and covered with a 20-cm package of sand (signal layer), which was then covered with tissue fabric.

Verhoeve's expertise has resulted in the realization of a 60,000 m2 solar park that will provide sustainable green energy to the region for decades to come and, not unimportantly, give a former landfill a function again. Completion of the park will take place in October 2025.

Contact

Do you have any questions? Please contact Jan Henk Schuurman(jan-henk.schuurman@verhoevemw.com or +31(0)6 1296 6057).

Verhoeve News 2025

Applying ozone in Industrial process water? Do's and Dont's!

Published Sept. 29, 2025

Verhoeve has been working with the active substance ozone (O3) for more than 20 years. A special oxidizing substance (in gas form) that is produced 'on site' via a generator from oxygen and has a good cleaning and disinfecting effect.

Dealing with contaminants in the soil, dealing with pathogens and bacteria in irrigation or process water, 'cleaning ín place' of airflows: it is all possible, but of course the proper and efficient application requires the necessary know-how and experience. But also to comply with certain rules within the (European) legislation!

It is definitely not the case that every company can 'just' ozone and many applications fall under the so-called Biocide legislation. Verhoeve, together with its sister company Agrozone, is admitted to this via membership of the European association of companies specialized in ozone 'Euota'.

If ozone is used as a technical solution with the aim of reusing industrial process water (e.g. disinfection of human pathogens and bacteria such as E-coli), approved application is guaranteed on the basis of a certified (self-developed) ozone generator that has demonstrated its ability to fulfill the intended purpose (or better claim). Verhoeve manufactures ozone generators in the range of 7 grams per hour to 2,000 grams per hour. In indiction, this enables water flows of 5 to 200 m3/hour to be treated within the aforementioned goal. Ozone as an active substance has been approved at the European level since 2023.

Another example of an ozone application in industrial process water is decolorization and deodorization and (if possible) the frequently associated high COD content. In this case, incidentally, there is 'oxidation' of certain substances in a water stream and Biocide legislation is also not automatically applicable.

In industrial process water, application generally takes place in the context of reusing that water: COD removal, decolorization, deodorization and disinfection. It is also used in support of other techniques such as activated carbon (longer retention time) or UV. Used mainly in the food industry, chemicals and textiles.

The advice is to always work with an approved supplier of ozone products (see, for example, www.euota.org for international suppliers). This can quickly establish feasibility in consultation. Further establish design parameters in the laboratory or through a pilot, but always deploy ozone on its strengths: oxidation of specifically difficult to degrade components, decolorization, deodorization. If properly applied and care is taken with proper design, formation of unwanted byproducts such as bromate, for example, can never occur.

Contact

For more information: Art Lobs(06-51107067 or a.lobs@verhoevemw.com) or Edward van de Ven(06-51864919 e.vd.ven@verhoevemw.com), Dordrecht office.

Verhoeve News 2025

Biological soil remediation of Fenol at Moerdijk

Published Sept. 29, 2025

At an industrial storage site at Moerdijk, Verhoeve removed phenol contamination using an in-situ method during the period 2023-2025. Both implementation and process monitoring were part of the work.

It involved phenol contamination in soil and groundwater from a recent spill. The spill had resulted in phenol being deposited on and in the soil, with locally solidified product present. The contamination was mainly present in the shallow soil layer up to about 3.5 m-mv. In total, 1,250 m3 of soil and 5,000 m3 of groundwater were contaminated. The maximum phenol concentration detected was 10,000,000 µg/l. The presence of company infrastructure prevented removal by excavation and Pump & Treat. To prevent the contamination from spreading further, a management system consisting of Pump & Treat had been put into operation by third parties. The pumped up groundwater containing phenol was temporarily collected in buffer tanks and disposed of by axle at high cost.

Prior to construction, Verhoeve demonstrated by means of a laboratory test in its own test facility in Dordrecht that the contamination could be removed biologically well aerobically. Based on this, Verhoeve drew up a design and Plan of Action. After approval of the Plan by the competent authority, the remediation operation was started.

Biological remediation consisted mainly of administering oxygen, nutrients and bacteria to the soil to facilitate aerobic degradation in the soil. Biosparging filters were installed for oxygenation. A groundwater circulation system (the 3 existing deep wells from the containment and 13 additional infiltration drains) with an above-ground aerobic bioreactor was installed for the administration/dispersal of nutrients and bacteria in the soil.

During the implementation of the remediation, additional phenol contamination was found in places, where it did not appear to be present during the investigation. At these locations, the system was expanded with additional filters/drains, which were connected to the existing system. For this, the system was designed to be sufficiently flexible and robust.

Beforehand, 2 years of remediation was planned to remove the remediation target. Despite the additional contamination found, we were able to remove the contamination to the agreed remediation target within this time frame (2023 - 2025).

Contact

Do you have any questions? Please contact Jeroen Schoovers(j.schoovers@verhoevemw.com or +31(0)6 2255 2057).

Verhoeve News 2025

Large-scale cleanup of petrochemical site

Published June 23, 2025

At a petrochemical site in the Rotterdam port area, Verhoeve Netherlands is currently remediating a large-scale oil / aromatics contamination in soil and groundwater. Much of our proverbial "toolbox" is being used to complete this job.

The unsaturated zone is remediated by compartmentalized excavation and external soil cleaning. Subsequently, the pure product present (in the form of a floating layer) is removed by multiphase extraction (MFE).

Once this bulk is removed, post-treatment of soil and groundwater takes place through groundwater extraction, biological above-ground stimulation and subsequent infiltration of treated water provided with nutrients. In addition, simultaneous biosparging takes place to further stimulate aerobic degradation in-situ. The set of techniques will remain operational until 2030.

This project is also characterized by limiting inconvenience and seeking combination benefits by making "work with work." Simultaneously with the soil remediation work, we are realizing a sewer renovation (GRE sewer) and tank dike renovation.

Contact

Do you have any questions? Please contact Jeroen Schoovers(j.schoovers@verhoevemw.com or +31(0)6 2255 2057).

Verhoeve News 2025

Verhoeve performs groundwater remediation at former Gijzenrooi landfill site Eindhoven

Published June 20, 2025

In the southeast of Eindhoven in the hamlet of Gijzenrooi is a former landfill site. Waste was dumped at this site in the past by nearby industries. The dump material consists of house waste, demolition waste, waste oil and chemical waste, including paint residues and solvents. As a result, the groundwater in the plume has become contaminated over the years. Several years ago, the landfill material was rearranged to a limited extent within the landfill and the landfill was provided with a sufficiently thick cover layer of clean soil. The site is located in a difficult-to-access natural area which makes equipment accessibility challenging.

Addressing VOCL contamination.

Groundwater quality has been monitored annually since 2011. Recent groundwater monitoring showed that achieving the agreed stable final situation is not feasible with groundwater monitoring alone. It proved necessary to fall back on a fallback scenario. The fallback scenario consists of two components:

1. Address the source of solvents in the landfill so that solvents are no longer dispersed from the landfill.

2. Halfway up the plume to optimize solvent degradation conditions and stimulate degradation.

Implement source approach (1a)

Work began early this year to remove the portion of the landfill from which the contamination in the groundwater plume originated. The purpose of this measure is to prevent secondary delivery of contamination from the landfill to groundwater.

Stimulate anaerobic degradation near the landfill (tap closed) (1b)

The purpose of stimulating anaerobic biodegradation is to prevent groundwater contamination from causing long-term recharge to the plume zone. In the area near the landfill with the highest concentrations, anaerobic biodegradation is stimulated.

The approach adopted was grid-wise direct injections to 10 m -mv for the purpose of anaerobic degradation/chemical reduction to terminate subsequent delivery of contamination to the plume. Distributed over an area of approximately 650 m2, zero-valent ferrous organic substrate was injected with bacterial graft.

Supplemented by verification of the process of occurrence of optimal degradation conditions for chlorinated hydrocarbons and decreasing concentrations. Carried out by periodic sampling of groundwater monitoring well filters in the treated area.

Measures midway through the plume (2)

A remediation measure is currently being devised by Verhoeve Nederland together with Royal Haskoning DHV and the client, the Municipality of Eindhoven, and will soon be implemented. The goal is to achieve effective cargo removal in the plume zone in order to realize a stable contamination plume with more certainty in the long term. In line with the source approach, direct injection has also been chosen here, but now in the 20-30 m-mv zone. Simultaneously with the monitoring of the source, the plume will also be monitored in the coming years.

Leveraging market expertise

Give Verhoeve a soil problem or research question and we will look for a solution. In this project, too, we worked with the client to find the best technique with the best value for money. We are good at that, so challenge us!

Contact

Do you have any questions? Please contact Jan Henk Schuurman(jan-henk.schuurman@verhoevemw.com or +31(0)6 1296 6057).

Verhoeve News 2025

Lab testing for the purpose of water treatment design

Published May 26, 2025

Verhoeve not only builds water treatment plants, but can also play a role in the preparation in determining the starting points for the treatment. We are regularly asked to provide solutions to challenges in water problems. A small selection of these projects:

A new factory site requires significant drainage. The water to be extracted is contaminated with heavy metals (cadmium and zinc) and has a low pH of 4. Verhoeve was engaged by the company to devise a suitable solution to meet the discharge requirements;
An existing Ultrafiltration plant at a Dutch grower in Africa keeps clogging up, despite multiple settling and pre-filtration steps. Stable operations are hampered as a result. The exact cause is unclear. Verhoeve was asked to first determine the cause and then offer a solution.

Verhoeve has a testing facility for such issues. For the former project, the new plant site, several tests were conducted with representative water samples. These tests focused on filtration with and without the addition of various additives at different concentrations. The additives include pH correction, coagulant and flocculant.

Attached below is a picture of water with different additives in the tests performed.

Findings

Based on such tests, the nature and quantity of products to be added was determined. For the drainage water contaminated with heavy metals, the concentration of heavy metals before and after treatment was of course also examined. The findings have since been translated for this site into a design for a full-scale water treatment plant with a capacity of 70 m3/hour.

Contact

We can imagine that you have questions, but perhaps you have a problem of your own as described here. If so, please contact Edward van de Ven,(e.vd.ven@verhoevemw.com, +32(0)483270932)

Verhoeve News 2025

Facilities sewage treatment plant at Lommel (Belgium)

Published May 24, 2025

Verhoeve Belgium performs a wide range of activities. For example, we recently performed work on behalf of Aquafin at the sewage treatment plant in Lommel in Belgium.

Cover influent basin

Part of the work involved installing an aluminum cover over the influent basin. The purpose of the cover is to limit nuisance to the surrounding area. From the point of view of safety, the cover was made overflowable, and fitted with a handrail, access ladder and access hatches.

Buffer

Another part of the work involved making facilities in the buffer itself. The purpose of these facilities is to better enable future work in the buffer from an ergonomic point of view. For example, safety ladders and intermediate landings were installed, as well as additional access hatches. In the future, installation parts can now be reached in a better way and lifted out of the basin if necessary.

For more information, please contact Toine Donkers, project manager(t.donkers@verhoevemw.com, +32(0)48 3475 809)

Verhoeve News 2025

Groundwater treatment plant in Hamme, PFAS removal in groundwater

Published May 22, 2025

The client for this project is Besix Unitec. Besix is currently carrying out work on utility lines in Hamme (Belgium), for which the groundwater level must be temporarily lowered over a distance of approximately 800 metres. The drainage area is located near a fire station, where there is PFAS contamination in the groundwater. In the preparation of the project, it was investigated how the drainage can best take place, and a groundwater purification plant is provided for the execution.

Removing PFAS from drainage water

Verhoeve Belgium takes care of removing the PFAS from the drainage water. To this end, a groundwater treatment plant has been built with a capacity of 50 m3/hour. This installation consists of several buffers, a sand filter, 2 activated carbon filters (connected in series) and a central control cabinet. The total installation can be read out remotely and adjusted if necessary.

Good results

The groundwater treatment plant has been running for some time now and the results are more than satisfactory. The entire plant is expected to be in operation at the site for about 8 months.

To learn more about this project, or if you have any questions please contact Jonas Wittocx, project engineer(j.wittocx@verhoevemw.com, +32(0)48 3270 932)