The publication on 3 September 2026 of Advocate General Juliane Kokott’s Opinion in Case C-193/25, Republic of Poland v European Parliament and Council, is probably the most significant legal development since the adoption of Directive (EU) 2024/3019 on urban wastewater treatment.
Beyond the practical importance of the litigation itself, the Opinion raises a far broader question: what happens when a major European regulatory framework, carrying substantial economic and social consequences, is built on studies and data whose scientific robustness has not been adequately scrutinised?
An excepcional Opinion
The Advocate General proposes that the Court of Justice annul Article 9(1)(a) and Annex III of the Directive, namely the provisions requiring manufacturers of pharmaceuticals and cosmetics to finance at least 80% of the costs of the quaternary treatment stage designed to remove micropollutants from urban wastewater.
What is truly significant, however, is not the proposed annulment itself, but the reasoning behind it.
The Advocate General does not suggest that the European legislature lacks the power to impose financial obligations on specific sectors. Rather, she questions something much more fundamental: whether the European institutions genuinely possessed a sufficiently robust scientific basis for selecting only pharmaceutical and cosmetic manufacturers as responsible for financing the overwhelming majority of the new system.
The problem: an insufficient scientific foundation
A recurring concern runs throughout the Opinion: the inability of the Commission, Parliament and Council to explain in a clear, verifiable and convincing manner how they arrived at the conclusion that pharmaceuticals and cosmetics should bear 80% of the overall cost burden.
The criticism focuses in particular on the methodology used to calculate the so-called “toxic load” attributable to each sector through PNEC indicators (Predicted No-Effect Concentrations).
According to the Advocate General, the legislative materials did not allow for proper verification of the calculations used, nor did they sufficiently justify certain values applied in the analysis. More importantly, the institutions were unable to provide satisfactory explanations for the doubts raised during the judicial proceedings concerning those data. And this is a critical issue because the entire system ultimately depends on those calculations.
Four medicines account for much of the result
One of the most striking aspects of the Opinion is the observation that a substantial part of the toxic load attributed to pharmaceuticals appears to result from an extremely limited number of substances.
The legal analysis highlights that, according to the methodology used during the legislative process, surprisingly only four medicines -telmisartan, dipyridamole, candesartan and amiodarone- would account for approximately 58% of the entire toxic load attributed to the pharmaceutical sector. The Advocate General relies heavily on this fact in questioning the reliability and sufficiency of the data used to justify allocating 80% of the costs to the pharmaceutical and cosmetic industries.
Importantly, the Opinion does not state that the figures are necessarily wrong. Instead, it advances an equally serious proposition: that the European institutions failed to demonstrate adequately why those figures should be regarded as correct and why they could legitimately serve as the basis for imposing billions of euros in regulatory costs.
The risk of legislating before understanding
Reading the Opinion leaves a troubling impression. At times, it appears that the political decision to allocate costs to the pharmaceutical and cosmetic sectors may have preceded the scientific demonstration that those sectors were indeed the principal contributors to the problem the legislation seeks to address.
The Advocate General states that the selection of pharmaceuticals and cosmetics for the extended producer responsibility regime was not based on a scientifically justified comparison with other groups of producers. She also notes that studies cited during the proceedings identified other significant sources of micropollutants, including pesticides and biocides.
The conclusion that emerges is worrying: a regulation with enormous economic implications may have been built upon an incomplete assessment of the true causes of the environmental problem it aims to solve.
Generic medicines: a warning that went largely unheeded
The Opinion also contains a particularly important observation concerning generic medicines. It expressly acknowledges that generic manufacturers cannot simply replace an active pharmaceutical ingredient with a less environmentally problematic alternative, since a generic medicine must, by definition, be identical to its reference product.
This is a regulatory point of immense significance. If the system is incapable of creating incentives for behavioural change within a substantial portion of the pharmaceutical market, then the environmental rationale underpinning the measure is fundamentally weakened. The scheme, initially presented as an environmental incentive mechanism, risks instead becoming a disguised financing mechanism. After all, a meaningful behavioural change is impossible as it would require withdrawing legally authorised and medically necessary medicines from the market.
Beyond the litigation: a question of institutional quality
The true significance of the Opinion extends far beyond the Urban Wastewater Treatment Directive itself. What is ultimately at stake is the credibility of the European regulatory process.
The European Commission enjoys extensive legislative initiative powers and exerts considerable technical influence over proposed legislation. Precisely for that reason, the quality of impact assessments and the scientific evidence supporting regulatory initiatives must be held to particularly high standards.
When a legislative measure has the potential to affect the supply of essential medicines, reshape strategic industrial sectors and generate multi-billion-euro economic consequences, the required standard should not merely be reasonable. It should be exceptionally rigorous. The Advocate General’s Opinion suggests that this standard may not have been met in this instance.
This debate is no longer simply about wastewater, pharmaceuticals or environmental protection. It is about how European regulation is produced and justified.
If an institution of the European Union can legitimately question the quality of the data underpinning one of the central pillars of a major Directive, then we must ask how such a measure progressed so far through the legislative process without those methodological weaknesses being identified and corrected at a much earlier stage.
Because when the quality of the underlying evidence itself becomes the subject of judicial scrutiny, the debate is no longer confined to wastewater treatment. It becomes a debate about the quality of European governance itself. And that is a matter of direct concern for businesses, citizens and Member States alike.