On 23 April 2026, the Belgian Constitutional Court ruled that a provision of the Walloon Decree of 1 March 2018 on soil management and remediation violates the constitutional principle of equality and non-discrimination. The case (n°50/2026) concerns an operator who ran a site under an environmental permit transferred from the site owner and was required to fulfil soil remediation obligations, despite the fact that the contamination was demonstrably caused by the transferor of that permit. The Court concludes that the fact that in such circumstances the transferee is prohibited from being exempted from those obligations constitutes an unjustified difference in treatment that is incompatible with the "polluter pays" principle.
The Facts
In 2009, an environmental permit for a hydrocarbon distribution site was granted for twenty years. In 2012, a Liège-based company began operating the site as a tenant holding a lease stating that the installations complied with legal standards and were free from pollution, even though signs of soil contamination had been identified years earlier. After ceasing operations in 2017, the company notified the Walloon Soil Remediation Directorate (DAS) and commissioned a soil study. The 2018 orientation study revealed exceedances of pollutant values and recommended a characterisation study. Although the company sought an exemption on the ground that the contamination predated its operation of the site, the DAS required the characterisation study to be completed, approved it, and subsequently required the company to prepare a remediation project. On 21 January 2021, the DAS refused the exemption request, holding that Article 30 of the Walloon Decree of 1 March 2018 barred exemption where the party responsible for the pollution was the transferor of the environmental permit. That decision was challenged before the Council of State, which referred a preliminary question to the Constitutional Court.
The Challenged Rule in Plain Terms
The Walloon Decree of 1 March 2018 establishes a system of obligations relating to soil management and remediation. When an operator ceases an installation or activity that poses a risk to the soil, it must in principle carry out a series of investigations and remediation measures. The decree does, however, provide an escape route: an operator can be exempted from the obligations that follow the initial orientation study if it can demonstrate that the contamination is attributable to another, solvent party.
There is, however, an important catch. The provision expressly excludes the operator from relying on this exemption when the identified responsible party is the transferor of the environmental permit. In concrete terms, this means the following: if a company operates a site under an environmental permit that it acquired from another company, and that other company caused the contamination, the transferee can never obtain an exemption — even if it is perfectly clear who the actual polluter is. Operators who did not acquire their permit through a transfer can, in an identical situation, obtain an exemption by pointing to the actual polluter. This difference in treatment lies at the heart of the preliminary question referred to the Constitutional Court.
The Legal Reasoning
Comparability of the Categories
To assess whether the principle of equality and non-discrimination (Articles 10 and 11 of the Constitution) has been breached, the Court must first examine whether the categories concerned are comparable. It considered that operators who acquired an environmental permit through a transfer are in a comparable position to operators who did not, insofar as both may be able to prove that pre-existing contamination was caused by another party. The contractual link between transferor and transferee was not, in itself, enough to make those situations incomparable. The Court also accepted that the distinction in treatment was based on an objective criterion, namely the operator's status as transferee and the fact that the identified polluter was the transferor.
Assessment Against the Pursued Objectives
The Court then examined two objectives put forward by the Walloon Government.
The first objective is to prevent an operator from unduly discharging itself of its obligations through a deliberately organised transfer of the permit. The Court acknowledges that this objective is legitimate but holds that the challenged provision produces precisely the opposite effect: by exempting the transferor from the decree's obligations when it is the actual polluter, the provision allows it to discharge itself of those obligations through an organised transfer. The measure is therefore not conducive to achieving this objective.
The second objective is to promote contractual freedom by preserving the continuity of economic activities and avoiding the blocking or slowing down of real estate and commercial transactions. The Court also acknowledges this objective as legitimate but finds that the challenged provision does not contribute to it either. On the contrary, the risk of a transferee having to bear the initial cost of contamination caused by the transferor that is only discovered after the fact creates an uncertainty that may delay transactions. The Court further notes that the challenged provision does not preclude the transferee from recovering the costs of its obligations from the transferor, but that this does not justify the validity of the provision.
The "Polluter Pays" Principle
The Court places its analysis under the umbrella of the "polluter pays" principle, which is enshrined in EU law, and observes that the decree of 1 March 2018, and in particular the exemption regime, is inspired by this principle. Conversely, the Court holds that the challenged exclusion goes against that same principle, as it results in a non-responsible transferee being unable to obtain an exemption while the actual polluter — the transferor — is effectively shielded.
The Court's Decision
Consequently, the Constitutional Court rules that Article 30, § 1, paragraph 1, 2°, of the Decree of the Walloon Region of 1 March 2018 on soil management and remediation violates the principle of equality and non-discrimination. The violation exists insofar as the provision prohibits the transferee of a permit from being released from its remediation obligations subsequent to an orientation study, when the contamination is attributable to a solvent third party who is the transferor of the permit. The Council of State, as the referring court, will now have to take this judgment into account in ruling on the underlying dispute.
Although the judgment does not formally annul Article 30, it significantly weakens its application in similar cases. It also increases the likelihood that the Walloon legislature will need to amend the provision in order to align the decree with the Constitutional Court's interpretation of the principle of equality and of the "polluter pays" principle.
Authors: Deniz Bahtijarevic and Hadrien Bosly (PwC Legal)
