AECOM’s environmental experts developed the remediation strategy to clean up Blue Gate, a former petrochemical brownfield site in Antwerp. Located along the Scheldt River, Blue Gate was first developed in 1902. At its peak it was one of Europe’s main gateways for petrochemical products.
Today, around 305,000 cubic metres of soil is contaminated with total petroleum hydrocarbons (TPH), and 2,500 cubic metres with light non-aqueous phase liquid (LNAPL). Some 1 million cubic metres contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and heavy metals.
AECOM is performing the work as part of the Blue O’pen consortium, the private partner in the public private partnership (PPP) delivering the project. DEME Environmental Contractors (DEC) is leading on the remediation and appointed us to redevelop the contaminated 100-hectare site.
In addition to the remedial strategy, our services include further mapping of contaminations and providing environmental follow-up of the remediation works.
Challenges
A big challenge in the remediation strategy was setting eco-friendly remediation goals which met regulatory requirements. Our environmental experts defined these based on risk, and selected them using the Best Available Technology Not Entailing Excessive Costs (BATNEEC) principle.
A main goal was to remove all mobile LNAPL, the formation of which is complex and dependent on many criteria. Blue Gate has several types of soil textures and oil, so using a generic target value would be inconclusive. Therefore, we developed an innovative protocol to rapidly screen the potential of LNAPL formation during remediation works.
Sustainability
Our remediation specialists used a number of strategies to minimise the project’s environmental footprint and enable the sustainable development of the site. These included:
On-site soil treatment
- This cut the environmental impact related to transporting and remediating contaminated soil by 90 per cent, and costs by 40 per cent.
Waterway transport
- We transport contaminated soil not eligible for on-site treatment by ship, minimising the impact on Antwerp’s already congested roads
Re-using soil
- Our soil management strategy re-used 400,000 cubic metres of soil and gravel to help reshape the terrain — rather than sending it to landfill
Digital solutions
As part of the remediation strategy, AECOM implemented a number of digital innovations during the works. We used drones to calculate volumes of stockpiles and monitor the re-use of materials. Our experts also developed a GPS smartphone app to pinpoint their exact location. An extensive new database enabled us to monitor the flow of raw materials.