The argument over who pays to get micropollutants out of Europe's wastewater is happening now. The EU's recast Urban Wastewater Treatment Directive (UWWTD, Directive (EU) 2024/3019) entered into force on 1 January 2025. Member States must pass it into their national law by 31 July 2027, and the treatment upgrades that it pays for will be completed between 2033 and 2045.

In February, the EU's General Court dismissed the pharmaceutical and cosmetics industry's challenge to the directive's producer-responsibility rules on the applicants' lack of standing, not on the validity of their claims.

In June, the European Parliament asked the Commission for a new impact assessment: identify the substances present in urban wastewater, verify the costs of quaternary treatment, and verify "the attribution of responsibility to the relevant sectors under the polluter pays principle."

Attribution is the crux. Existing producer-responsibility schemes, the resolution notes, were developed for waste streams from "identifiable point sources, where producers can effectively organise, monitor and control collection and treatment systems."

Collected wastewater has no identifiable point source. Nobody follows a compound from production, through distribution and consumption, to a treatment plant. So a scheme built around reliable, mechanical observation is being applied to a case where every contribution has to be inferred, and the inferences are contested by both the producers and the Member States. The Commission attributes roughly 92% of the micropollutant load to pharmaceuticals and cosmetics, a figure disputed on methodology. Germany and Spain report treatment costs several times the Commission's estimate. The JRC has since reconfirmed the Commission's figures, and the disagreement hasn't moved a millimeter.

Article 9 of the UWWTD describes the endgame clearly: producers are to cover at least 80% of the treatment costs and, with no percentage attached at all, the full cost of collecting and verifying the data. What it does not describe is the method: how a producer defends an inferred share, how an operator defends its bill, and how a supervising body checks both without any party's data being exposed to its competitors.

That is what we build at Gitterdan GmbH.

If you are approaching this problem from either side of the inference balance sheet, we'd like to talk.