Case C-668/25: Action brought on 10 October 2025 – European Commission v Romania
Date: 2025-10-10
Institutions: Court of Justice
Subjects: environmental protection, infringement of EU law, national implementing measure, pollution control measures, sensitive area, wastewater, water treatment








C_202506299EN.000101.fmx.xml












Official Journal of the European Union


EN
C series













C/2025/6299


1.12.2025






Action brought on 10 October 2025 – European Commission v Romania


(Case C-668/25)

(C/2025/6299)
Language of the case: Romanian

Parties


Applicant: European Commission (represented by: A. Biolan and E. Sanfrutos Cano, acting as Agents)

Defendant: Romania

Form of order sought

The applicant claims that the Court should:






1.


declare, under Article 258 TFEU, that, by failing to adopt the necessary measures to:






—


ensure that, in 150 of the identified agglomerations concerned by the application initiating the proceedings which have a population equivalent of more than 10 000, collecting systems for urban waste water are provided at the latest by 31 December 2013, in accordance with Article 3 of Directive 91/271/EEC, (1) and with Section A of Annex I to that directive;










—


ensure that, in 154 of the agglomerations concerned by the application initiating the proceedings which have a population equivalent of more than 10 000 and which discharge urban waste water into receiving waters known as ‘sensitive areas’ within the meaning of Directive 91/271/EEC, that urban waste water is subject, before discharge, to more stringent treatment than secondary treatment or an equivalent treatment, at the latest by 31 December 2015, in accordance with Articles 4 and 10 of that directive and with Sections B and D of Annex I thereto;










—


ensure that, in 155 of the agglomerations concerned by the application initiating the proceedings, the urban waste water entering collecting systems is subject, before discharge into sensitive areas or into the relevant catchment areas of sensitive areas, to more stringent treatment than that described in Article 4 of Directive 91/271/EEC, as provided for in Articles 5 and 10 thereof;










—


fulfil the monitoring obligation, as laid down in Article 15(1) of Directive 91/271/EEC and in Sections B and D of Annex I to that directive, with regard to 155 of the agglomerations concerned by the application initiating the proceedings,
Romania has failed to fulfil its obligations under Article 3 of the directive and Section A of Annex I thereto, under Articles 4 and 10 of that directive and Sections B and D of Annex I thereto, under Articles 5 and 10 of the directive, and under Article 15(1) of that directive and Sections B and D of Annex I thereto;














2.


order Romania to pay the costs.





Pleas in law and main arguments

In support of its action, the Commission relies on four pleas in law, alleging infringement of Directive 91/271/EEC.
By its first plea in law, the Commission complains that Romania has failed to fulfil its obligations under Article 3(1) of Directive 91/271/EEC, read in conjunction with Section A of Annex I thereto, owing to the fact that it has failed to ensure that all the waste water produced in the 150 agglomerations referred to in the application initiating the proceedings is discharged. Article 3 of Directive 91/271/EEC concerning urban waste water treatment imposes a clear and unambiguous obligation on Member States as to the result to be achieved, from which it follows that, at the latest by 31 December 2005, all the waste water from agglomerations with a population equivalent of more than 10 000 is to be subject to a collecting system for urban waste water. In accordance with the provisions of [the Treaty concerning the Accession of the Republic of Bulgaria and Romania to the European Union (‘the Treaty concerning the Accession of Romania’)], by way of derogation from Article 3 of the directive, the requirements regarding collecting systems are to apply in full in Romania as from 31 December 2013. As from that date, Romania was required to ensure that all agglomerations with a population equivalent of more than 10 000 were provided with collecting systems for urban waste water. By way of derogation, the third subparagraph of paragraph 1 of Article 3 of Directive 91/271/EEC provides for an exception to the obligation to introduce a collecting system, either in a situation where this ‘would produce no environmental benefit or because [establishing such a system] would involve excessive cost’. In such duly justified cases, ‘individual systems or other appropriate systems which achieve the same level of environmental protection shall be used’.
By its second plea in law, the Commission submits that, because of the fact that Romania has not taken, in respect of the 154 agglomerations referred to in the application initiating the proceedings, the necessary measures for the treatment of the waste water in those agglomerations, that Member State has failed to fulfil its obligations under Article 4(1) and (3) and Article 10 of Directive 91/271/EEC, read in conjunction with Sections B and D of Annex I thereto. In accordance with Article 4(1) of Directive 91/271/EEC, the Member States are to ensure that urban waste water entering collecting systems is, before discharge, subject to secondary treatment or equivalent treatment. In accordance with point 8 of Article 2 of Directive 91/271/EEC, ‘secondary treatment’ means treatment of urban waste water which consists, in principle, of biological treatment and secondary treatment or another process which meets the requirements of Table 1 of Annex I to that directive. Pursuant to Article 4(3) of Directive 91/271/EEC, discharges from the urban waste water treatment plants of the agglomerations in question must satisfy the relevant requirements of Section B of Annex I to that directive. In accordance with the provisions of the Treaty concerning the Accession of Romania, by way of derogation from Article 4 of the directive, the requirements regarding the treatment of waste water are to apply in full in Romania as from 31 December 2015.
By its third plea in law, the Commission submits that, because of the fact that Romania has not taken, in respect of the 155 agglomerations referred to in the application initiating the proceedings, the necessary measures for the treatment of the waste water in those agglomerations, that Member State has failed to fulfil its obligations under Articles 5 and 10 of Directive 91/271/EEC. Article 5(2) of that directive requires Member States to ensure that urban waste water entering collecting systems, before discharge into sensitive areas, is subject to more stringent treatment than that described in Article 4 thereof for all discharges from agglomerations with a population equivalent of more than 10 000. Article 5(3) of the directive requires that discharges from urban waste water treatment plants into sensitive areas be in line with the relevant provisions of Section B of Annex I thereto. Article 5(5) of that directive provides that discharges from urban waste water treatment plants which are situated in the relevant catchment areas of sensitive areas and which contribute to the pollution of these areas are to be subject to Article 5(2), (3) and (4) thereof.
In accordance with the provisions of the Treaty concerning the Accession of Romania, by way of derogation from Article 5(5) of the directive, the more stringent treatment of waste water is to apply in full in Romania as from 31 December 2015.
By its fourth plea in law, the Commission submits that, for the 155 agglomerations referred to in the application initiating the proceedings, Romania has failed to fulfil its obligation to monitor discharges from urban waste water treatment plants to verify compliance with the requirements laid down in Article 15 of the directive, read in conjunction with Sections B and D of Annex I thereto.
On 8 June 2018, the Commission sent Romania a letter of formal notice. On 30 October 2020, the Commission sent an additional letter of formal notice, which replaced the initial letter of formal notice of 8 June 2018. On 8 February 2022, the Commission sent Romania a reasoned opinion. After analysing the responses provided, the analytical data provided, and the other information available, the Commission came to the conclusion that the infringements of Article 3 of Directive 91/271/EEC and Section A of Annex I thereto, of Articles 4 and 10 of that directive and Sections B and D of Annex I thereto, of Articles 5 and 10 of the directive, and of Article 15(1) of that directive and Sections B and D of Annex I thereto persist in respect of the agglomerations referred to in the application initiating the proceedings.


(1)  Council Directive of 21 May 1991 concerning urban waste water treatment (OJ 1991 L 135, p. 40).


ELI: http://data.europa.eu/eli/C/2025/6299/oj
ISSN 1977-091X (electronic edition)