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.
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!
