(Failure of a Member State to fulfil obligations – Directive 91/271/EEC – Urban waste water treatment – Article 5(1) and (2) and Annex II – Failure to identify sensitive areas – Meaning of ‘eutrophication’ – Failure to implement more stringent treatment of discharges into sensitive areas)

Summary of the Judgment

(Council Directive 91/271, Arts 2(11) and 5(1))

(Council Directive 91/271, Art. 5(2) and (3), Annexes I.B(3) and II.A(a), second para.)

1.By virtue of Article 5(1) of Directive 91/271 concerning urban waste water treatment, the Member States are obliged to identify the areas where discharges of urban waste water contribute significantly to eutrophication or the risk of eutrophication.

The definition of eutrophication in Article 2(11) of that directive must be interpreted in the light of its objective, which goes beyond the mere protection of aquatic ecosystems and attempts to conserve man, fauna, flora, soil, water, air and landscapes from any significant harmful effects of the accelerated growth of algae and higher forms of plant life resulting from discharges of urban waste water.

For there to be eutrophication within the meaning of the directive, there must be a cause and effect relationship between enrichment by nutrients and the accelerated growth of algae and higher forms of plant life on the one hand and, on the other hand, between the accelerated growth and an undesirable disturbance of the balance of organisms present in the water and to the quality of the water concerned. Species changes involving loss of ecosystem biodiversity, nuisances due to the proliferation of opportunistic macroalgae and severe outbreaks of toxic or harmful phytoplankton constitute an undesirable disturbance of the balance of organisms present in the water. As regards deterioration of water quality, that criterion refers not only to deterioration of the quality of the water which produces harmful effects for ecosystems but also deterioration of the colour, appearance, taste or odour of the water or any other change which prevents or limits water uses.

(see paras 16, 19, 23-25)

2.Under Article 5(3), in conjunction with Annex I.B(3), of Directive 91/271 concerning urban waste water treatment, the treatment provided for in Article 5(2) of that directive is more stringent than that described in Article 4 of that directive and covers urban waste water entering collecting systems and from agglomerations of more than 10 000 ‘population equivalent’ (p.e.). That treatment means, inter alia, that discharges into areas sensitive to eutrophication must satisfy the requirements shown in Table 2 of that Annex, subject, however, to the provisions of the second paragraph of Annex II.A(a) to that directive, which provide that, as regards large agglomerations, the removal of phosphorus and/or nitrogen should be included unless it can be demonstrated that the removal will have no effect on the level of eutrophication.

(see paras 104-105)

JUDGMENT OF THE COURT (Second Chamber) 23 September 2004 (1)

(Failure of a Member State to fulfil obligations – Directive 91/271/EEC – Urban waste water treatment – Article 5(1) and (2) and Annex II – Failure to identify sensitive areas – Meaning of ‘eutrophication’ – Failure to implement more stringent treatment of discharges into sensitive areas)

In Case C-280/02, ACTION under Article 226 EC for failure to fulfil obligations, brought on 30 July 2002,

Commission of the European Communities, represented initially by M. Nolin and subsequently by G. Valero Jordana and F. Simonetti, acting as Agents, with an address for service in Luxembourg,

applicant,

French Republic, represented by G. de Bergues, D. Petrausch and E. Puisais, acting as Agents, with an address for service in Luxembourg,

defendant,

THE COURT (Second Chamber),

composed of: C.W.A. Timmermans, President of the Chamber, J.-P. Puissochet, R. Schintgen, F. Macken (Rapporteur) and N. Colneric, Judges,

Advocate General: L.A. Geelhoed, Registrar: R. Grass,

having regard to the written procedure, after considering the observations submitted by the parties,

after hearing the Opinion of the Advocate General at the sitting on 25 March 2004,

gives the following

1 This request for a preliminary ruling concerns the interpretation of Directive 2011/92/EU of the European Parliament and of the Council of 13 December 2011 on the assessment of the effects of certain public and private projects on the environment (OJ 2012 L 26, p. 1), as amended by Directive 2014/52/EU of the European Parliament and of the Council of 16 April 2014 (OJ 2014 L 124, p. 1) (‘Directive 2011/92’).

2 The request has been made in proceedings between, on the one hand, Waltham Abbey Residents Association and, on the other hand, An Bord Pleanála (Planning Board, Ireland; ‘the Board’), Ireland and the Attorney General (Ireland), concerning authorisation granted by the Board for a strategic residential housing development.

Legal context

European Union law

Directive 2011/92

Recitals 7 to 9 of Directive 2011/92 state:

‘(7) Development consent for public and private projects which are likely to have significant effects on the environment should be granted only after an assessment of the likely significant environmental effects of those projects has been carried out. …

(8) Projects belonging to certain types have significant effects on the environment and those projects should, as a rule, be subject to a systematic assessment.

ECLI:EU:C:2025:140

(9) Projects of other types may not have significant effects on the environment in every case and those projects should be assessed where the Member States consider that they are likely to have significant effects on the environment.’

Article 2(1) of that directive provides:

‘Member States shall adopt all measures necessary to ensure that, before development consent is given, projects likely to have significant effects on the environment by virtue, inter alia, of their nature, size or location are made subject to a requirement for development consent and an assessment with regard to their effects on the environment. Those projects are defined in Article 4.’

Under Article 3(1) of that directive:

‘The environmental impact assessment shall identify, describe and assess in an appropriate manner, in the light of each individual case, the direct and indirect significant effects of a project on the following factors:

…

(b) biodiversity, with particular attention to species and habitats protected under [Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora (OJ 1992 L 206, p. 7), as amended by Council Directive 2013/17/EU of 13 May 2013 (OJ 2013 L 158, p. 193) (“Directive 92/43”)] and Directive 2009/147/EC [of the European Parliament and of the Council of 30 November 2009 on the conservation of wild birds (OJ 2010 L 20, p. 7)];

…’

Article 4 of Directive 2011/92 provides:

‘1. Subject to Article 2(4), projects listed in Annex I shall be made subject to an assessment in accordance with Articles 5 to 10.

(a) a case-by-case examination;

(b) thresholds or criteria set by the Member State.

Member States may decide to apply both procedures referred to in points (a) and (b).

Where a case-by-case examination is carried out or thresholds or criteria are set for the purpose of paragraph 2, the relevant selection criteria set out in Annex III shall be taken into account. Member States may set thresholds or criteria to determine when projects need not undergo either the determination under paragraphs 4 and 5 or an environmental impact assessment, and/or thresholds or criteria to determine when projects shall in any case be made subject to an environmental impact assessment without undergoing a determination set out under paragraphs 4 and 5.

Where Member States decide to require a determination for projects listed in Annex II, the developer shall provide information on the characteristics of the project and its likely significant effects on the environment. The detailed list of information to be provided is specified in Annex IIA. The developer shall take into account, where relevant, the available results of other relevant assessments of the effects on the environment carried out pursuant to Union legislation other than this Directive. The developer may also provide a description of any features of the project and/or measures envisaged to avoid or prevent what might otherwise have been significant adverse effects on the environment.

The competent authority shall make its determination, on the basis of the information provided by the developer in accordance with paragraph 4 taking into account, where relevant, the results of preliminary verifications or assessments of the effects on the environment carried out pursuant to Union legislation other than this Directive. The determination shall made available to the public and:

(a) where it is decided that an environmental impact assessment is required, state the main reasons for requiring such assessment with reference to the relevant criteria listed in Annex III; or

(b) where it is decided that an environmental impact assessment is not required, state the main reasons for not requiring such assessment with reference to the relevant criteria listed in Annex III, and, where proposed by the developer, state any features of the project and/or measures envisaged to avoid or prevent what might otherwise have been significant adverse effects on the environment.

Member States shall ensure that the competent authority makes its determination as soon as possible and within a period of time not exceeding 90 days from the date on which the developer has submitted all the information required pursuant to paragraph 4. In exceptional cases, for instance relating to the nature, complexity, location or size of the project, the competent authority may extend that deadline to make its determination; in that event, the competent authority shall inform the developer in writing of the reasons justifying the extension and of the date when its determination is expected.’

‘1. A description of the project, including in particular:

(a) a description of the physical characteristics of the whole project and, where relevant, of demolition works;

(b) a description of the location of the project, with particular regard to the environmental sensitivity of geographical areas likely to be affected.

(a) the expected residues and emissions and the production of waste, where relevant;

(b) the use of natural resources, in particular soil, land, water and biodiversity.

ECLI:EU:C:2025:140

JUDGMENT OF 6. 3. 2025 – CASE C-41/24 WALTHAM ABBEY RESIDENTS ASSOCIATION

The criteria of Annex III shall be taken into account, where relevant, when compiling the information in accordance with points 1 to 3.’

Annex III to that directive sets out the ‘criteria to determine whether the projects listed in Annex II should be subject to an environmental impact assessment’.

Directive 2014/52

Recitals 11 and 29 of Directive 2014/52 state:

‘(11) The measures taken to avoid, prevent, reduce and, if possible, offset significant adverse effects on the environment, in particular on species and habitats protected under [Directive 92/43] and Directive 2009/147 …, should contribute to avoiding any deterioration in the quality of the environment and any net loss of biodiversity, in accordance with the [European] Union’s commitments in the context of the [United Nations Convention on Biological Diversity, signed in Rio de Janeiro on 5 June 1992,] and the objectives and actions of the Union Biodiversity Strategy up to 2020 laid down in the [Communication from the Commission to the European Parliament, the Council, the Economic and Social Committee and the Committee of the Regions] of 3 May 2011 entitled ‘Our life insurance, our natural capital: an EU biodiversity strategy to 2020’ [(COM(2011) 244 final)]

…

(29) When determining whether significant effects on the environment are likely to be caused by a project, the competent authorities should identify the most relevant criteria to be considered and should take into account information that could be available following other assessments required by Union legislation in order to apply the screening procedure effectively and transparently. In this regard, it is appropriate to specify the content of the screening determination, in particular where no environmental impact assessment is required. Moreover, taking into account unsolicited comments that might have been received from other sources, such as members of the public or public authorities, even though no formal consultation is required at the screening stage, constitutes good administrative practice.’

Directive 92/43

Article 6(3) of Directive 92/43 provides:

‘Any plan or project not directly connected with or necessary to the management of the site but likely to have a significant effect thereon, either individually or in combination with other plans or projects, shall be subject to appropriate assessment of its implications for the site in view of the site’s conservation objectives. In the light of the conclusions of the assessment of the implications for the site and subject to the provisions of paragraph 4, the competent national authorities shall agree to the plan or project only after having ascertained that it will not adversely affect the integrity of the site concerned and, if appropriate, after having obtained the opinion of the general public.’

Article 12(1) of that directive provides:

‘Member States shall take the requisite measures to establish a system of strict protection for the animal species listed in Annex IV(a) in their natural range, prohibiting:

(a) all forms of deliberate capture or killing of specimens of these species in the wild;

(b) deliberate disturbance of these species, particularly during the period of breeding, rearing, hibernation and migration;

(c) deliberate destruction or taking of eggs from the wild;

(d) deterioration or destruction of breeding sites or resting places.’

Point (a) of Annex IV to that directive mentions ‘all species’ of bats belonging to the suborder of ‘microchiroptera’.

Irish law

The pre-litigation procedure

9Following extensive correspondence with the French authorities concerning the implementation of Directive 91/271 in French law, on 22 October 1999 the Commission, which took the view that that implementation was incomplete, sent the French Government a letter of formal notice alleging, inter alia, that it had incompletely identified sensitive areas as the result of having failed to identify the eutrophied water bodies in the Seine-Normandy, Artois-Picardy, Loire-Brittany and Rhône-Mediterranean-Corsica basins, and failed to subject to more stringent treatment urban waste water discharged into sensitive areas which had already been identified and into areas which should have been identified as sensitive.

10Since it deemed the explanations of the French authorities unsatisfactory, on 10 April 2001 the Commission delivered a reasoned opinion to the French Republic.

11Not finding the reply by the French authorities to be persuasive, it decided to bring the present action.

The application

First complaint, alleging incomplete identification of sensitive areas

Meaning of eutrophication

12Since the Commission and the French Government do not agree on the scope of the definition set out in Article 2(11) of Directive 91/271, it is first of all necessary to clarify the meaning of eutrophication for the purposes of that directive.

13As stated in the second paragraph of Article 1, the objective of Directive 91/271 is to protect the environment from the adverse effects of urban waste water discharges.

14That directive was adopted on the basis of Article 130s of the EC Treaty (now, after amendment, Article 175 EC), which is intended to achieve the objectives of Article 130r of the EC Treaty (now, following amendment, Article 174 EC). Pursuant to the latter article, Community policy on the environment is to contribute inter alia to preserving, protecting and improving the quality of the environment and protecting human health.

15Such a policy thus seeks to prevent, mitigate or eliminate the harmful effects of human activities on flora and fauna, soil, water, air, climate, landscape and sites of particular interest, and on the health and quality of life of persons. It has been implemented, in their respective areas, by Council Directive 75/442/EEC of 15 July 1975 on waste (OJ 1975 L 194, p. 39), as amended by Council Directive 91/156/EEC of 18 March 1991 (OJ 1991 L 78, p. 32); Council Directive 85/337/EEC of 27 June 1985 on the assessment of the effects of certain public and private projects on the environment (OJ 1985 L 175, p. 40), as amended by Council Directive 97/11/EC of 3 March 1997 (OJ 1997 L 73, p. 5); and Council Directive 91/676/EEC of 12 December 1991 concerning the protection of waters against pollution caused by nitrates from agricultural sources (OJ 1991 L 375, p. 1).

16The objective pursued by Directive 91/271 therefore goes beyond the mere protection of aquatic ecosystems and attempts to conserve man, fauna, flora, soil, water, air and landscapes from any significant harmful effects of the accelerated growth of algae and higher forms of plant life resulting from discharges of urban waste water.

17The definition of eutrophication in Article 2(11) of Directive 91/271 must be interpreted in the light of that objective.

18Pursuant to that provision, eutrophication is characterised by the confluence of four criteria:

– the enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus;

– the accelerated growth of algae and higher forms of plant life;

– an undesirable disturbance of the balance of organisms present in the water;

– deterioration of the quality of the water concerned.

19In addition, for there to be eutrophication within the meaning of Directive 91/271, there must be a cause and effect relationship between enrichment by nutrients and the accelerated growth of algae and higher forms of plant life on the one hand and, on the other hand, between the accelerated growth and an undesirable disturbance of the balance of organisms present in the water and to the quality of the water concerned.

20As regards the third criteria, the French Government submits that the mere proliferation of a plant species is not sufficient to establish an undesirable disturbance so long as there is no disruption to the balance of other organisms present in the water.

21As is clear from, inter alia, the report of January 2001 by the Institut français de recherche pour l’exploitation de la mer (hereinafter ‘Ifremer’), entitled ‘Eutrophication of marine and brackish waters in Europe and, in particular, in France’ (hereinafter ‘the Ifremer report of 2001’) and the report of April 2000 by Environmental Resources Management (hereinafter ‘ERM’), entitled ‘Criteria used for the definition of eutrophication in fresh and marine/coastal waters’, produced by the Commission, the equilibrium of an aquatic ecosystem is the result of complex interactions among the different species present and with the environment. Any proliferation of a particular species of algae or other plant therefore constitutes, as such, a disturbance of the balance of the aquatic ecosystem and, accordingly, of the balance of the organisms present in the water, even when other species remain stable. Moreover, given the competition between plant species for nutrient salts and luminous energy, the proliferation of one or several species, by monopolising the resources necessary to the growth of other algae and aquatic plants, very often if not always entails reductions in other species.

22The third criterion requires, however, that such a disturbance of the balance of organisms present in the water be ‘undesirable’. To the extent that, as is clear from paragraph 16 of the present judgment, the objective pursued by Directive 91/271 goes beyond the mere protection of aquatic ecosystems, that undesirability must also be considered to be established where there are significant harmful effects not only on flora and fauna but also on man, the soil, water, air or landscape.

23Species changes involving loss of ecosystem biodiversity, nuisances due to the proliferation of opportunistic macroalgae and severe outbreaks of toxic or harmful phytoplankton therefore constitute an undesirable disturbance of the balance of organisms present in the water.

24The fourth criterion, in contrast to the analysis by the French Government, refers not only to deterioration of the quality of the water which produces harmful effects for ecosystems but also deterioration of the colour, appearance, taste or odour of the water or any other change which prevents or limits water uses such as tourism, fishing, fish farming, clamming and shellfish farming, abstraction of drinking water or cooling of industrial installations.

25Given the aim pursued by the Community legislature, which is to protect the environment from deterioration due to the discharge of urban waste water, the obligation on the Member States under Article 5(1) of Directive 91/271 requires only that they identify the areas where such discharges contribute significantly to eutrophication or the risk of eutrophication (see, by analogy, as regards Directive 91/676, Case C-293/97 Standley and Others [1999] ECR I‑2603, paragraph 35).

Scope of the first complaint

26It is appropriate to ascertain, for each of the areas referred to by the Commission in its application, whether the area in question should have been designated as an area sensitive to eutrophication.

27Pursuant to Annex II.A(a) to Directive 91/271, natural freshwater lakes, other freshwater bodies, estuaries and coastal waters ‘which are found to be eutrophic or which in the near future may become eutrophic if protective action is not taken’ must be identified as sensitive areas.

28The French Government contends that the letter of formal notice referred only to established cases of eutrophication and that although, in the reasoned opinion and the application, the Commission mentioned taking into account the risk of eutrophication, it did not draw inferences for specific areas therefrom. The Commission thus goes beyond the grounds which it developed both at the pre‑litigation stage and in its application when it concludes in its reply that, while eutrophication was not established in the areas referred to, those areas are at least at risk of eutrophication.

29In accordance with settled case-law, the letter of formal notice from the Commission to the Member State, and then the reasoned opinion issued by the Commission, delimit the subject-matter of the dispute, so that it cannot thereafter be extended. Consequently, the reasoned opinion and the action brought by the Commission must be based on the same complaints as those set out in the letter of formal notice initiating the pre-litigation procedure (Case C-365/97 Commission v Italy [1999] ECR I-7773, paragraph 23, and Case C-229/00 Commission v Finland [2003] ECR I-5727, paragraph 44).

30However, that requirement cannot be carried so far as to mean that in every case the statement of complaints in the letter of formal notice, the operative part of the reasoned opinion and the form of order sought in the application must be exactly the same, where the subject-matter of the dispute has not been extended or altered (Commission v Italy, paragraph 25, and Commission v Finland, paragraph 46, both cited above).

31In this case, by stating for the first time at the stage of its reply that even if the areas referred to in its application are not eutrophic, as it claims, they should nevertheless have been classified as areas sensitive to eutrophication because they could become eutrophic in the near future, the Commission neither extended nor altered during the proceedings the subject-matter of the action, which relates to the failure to identify certain bodies of water as sensitive to eutrophication although, pursuant to Annex II.A(a) to Directive 91/271, eutrophic areas and those which in the near future may become eutrophic are also to be identified as sensitive areas.

The Seine-Normandy basin

– The Seine bay

32It is not in dispute that the waters of the Seine bay suffer from both enrichment by nutrients, in particular nitrogen compounds, inputs of which have continued to increase, and the accelerated growth of algae and higher forms of plant life (see Case C-258/00 Commission v France [2002] ECR I‑5959, paragraph 64).

33All the reports and studies produced by the Commission, in particular the ecological modelling work developed in Philippe Cugier’s doctoral thesis for the University of Caen defended in 1999, entitled ‘Modélisation du devenir à moyen terme dans l’eau et le sédiment des éléments majeurs (N, P, Si) rejetés par la Seine en baie de Seine’ (‘Modelling of medium-term development in water and sediments of the major elements (N, P, Si) discharged by the Seine into the Seine bay’), conclude that there is a cause and effect relationship between the amount and relative proportions of nutrient inputs in the Seine bay and the phytoplankton blooms observed each year in that area.

34As regards the argument of the French Government that Mr Cugier’s thesis is based on an imperfect 3D ecological model, it should be recalled that pursuant to Article 174 EC, Community policy on the environment is to be based on the precautionary principle. In the present case, given the available scientific and technical knowledge, the degree of probability of a causal link between nutrient inputs into the Seine bay and the accelerated growth of phytoplankton in that area is sufficient to require the adoption of the environmental protection measures provided for in Directive 91/271 if the other criteria for eutrophication are fulfilled.

The French Government denies that phytoplankton production in the Seine bay produces an undesirable disturbance of the balance of organisms present in the water.

36In that regard, it is clear from all the studies produced by the Commission that this area is experiencing proliferation of the phytoplankton species of the genus Dinophysis, which produces DSP toxins (Diarrheic Shellfish Poisoning), liable to accumulate in shellfish and dangerous to humans when those shellfish are consumed. Between 1990 and 1999, sizable concentrations of Dinophysis, sufficient to give rise to the accumulation of toxins in shellfish, were observed throughout the bay, particularly in its central area; during that period, the presence of Dinophysis was observed between 2 and 6 times in the west of the bay and 7 to 10 times in the centre and east of the bay (Ifremer report of 2001). Those proliferations ‘appear to have intensified in the past several years between Courseulles (Calvados) and Dieppe (Seine-Maritime), giving rise to a periodic ban on collecting shellfish’ (Schéma directeur d’aménagement et de gestion des eaux du bassin Seine-Normandie (Development and management plan for the waters of the Seine-Normandy basin), hereinafter ‘the SDAGE Seine-Normandy’).

37In addition, another species of phytoplankton, Phaeocystis, ‘has for several years been proliferating in certain sections of Seine-Maritime and of Calvados’ and, while not toxic, gives rise to ‘silting and damages the coast’s appeal to tourists’ (SDAGE Seine-Normandy). The phytoplankton Phaeocystis is known for producing, in high concentrations, the appearance of a mass of viscous foam which covers the surface of the water and washes up on the coast or clogs fishing nets.

38As pointed out in paragraph 23 of this judgment, such an evolution in the structure of the phytoplankton community, strengthening the presence of toxic or harmful species, amounts to an undesirable disturbance of the balance of organisms present in the water. Contrary to what the French Government contends, that evolution concerns the Seine bay in its entirety, even if its central and eastern parts are the most affected.

39The limitations and difficulties caused by the phytoplankton Dynophisis to the collection of shellfish and by the phytoplankton Phaeocystis to tourist activities on the bay of Seine’s coast also represent deterioration of the quality of the water in that bay.

40Forty percent of the nitrogen flows carried by the Seine – which is the main tributary river for the Seine bay – are of urban origin (ERM report of February 1999, entitled ‘Verification of vulnerable zones identified under the nitrate directive and sensitive areas identified under the urban waste water treatment directive’) (hereinafter ‘the 1999 ERM report’). The French Government maintains that only 28% of the nitrogen discharges were of urban origin in 2000 but does not supply any documentation in support of that statement. Moreover, even if the proportion were not 40% but 28%, the Commission would be justified in concluding that urban waste water discharges contribute significantly to the eutrophication of the water of the Seine bay.

41The French Government also submits that Mr Cugier’s thesis relativises the possibility of taking technical measures to reduce inputs of nitrogen and phosphorus. Nevertheless, nothing in the extracts from that thesis produced before the Court substantiates that assertion. In any event, as the Commission has correctly pointed out, the question of the feasibility of reducing nutrient inputs of urban origin was not broached at the time when areas sensitive to eutrophication were identified.

42Therefore, the Commission was right to find that the Seine bay is eutrophic within the meaning of Directive 91/271 and that it should have been identified as an area sensitive to eutrophication.

43The reports and studies produced by the Commission show that downstream from its confluence with the Andelle the Seine suffers from serious phytoplankton proliferation.

44At the time of such proliferations, ‘phytoplanktonic biomass may … consume more oxygen than it produces’ and ‘phytoplanktonic declines therefore lead to oxygen deficits’ (document ‘Seine-Aval 2: L’analyse et la gestion environnementales’) (‘Seine-Aval 2: Environmental analysis and management’). The de-oxygenation of the Seine estuary has led to an ‘area of almost complete anoxia, extending over almost 50 km’, which ‘renders the water unfit for many uses and for all higher organisms’ and ‘constitutes an insurmountable barrier for almost six months of the year for migratory fish such as salmon or eel’ (study ‘Programme scientifique Seine-Aval: L’oxygène’) (‘Seine-Aval scientific programme: Oxygen’).

45Those phenomena clearly constitute an undesirable disturbance of the balance of organisms present in the water and to the quality of the water.

46The fact, put forward by the French Government, that the very large reduction in phosphorus inputs had only very slightly increased the annual average oxygen rate in the Poses-Honfleur section is irrelevant, as nitrogen inputs have continued to increase at the same time.

47Under those conditions, the Commission rightly found that all Artois-Picardie’s coastal waters are eutrophic within the meaning of Directive 91/271 and that they should have been identified as areas sensitive to eutrophication.

58In support of its action, the Commission has produced various documents from the Agence de l’Eau Artois-Picardie which indicate that ‘the improvement in general water quality observed over the past years, together with a large load of nitrogen but above all of phosphorus, favours plant growth, whether of phytoplankton, filamentous algae or macrophytes (duckweed, water lilies, etc)’, that ‘that plant growth generates numerous nuisances, the most frequent being water colouration, odours, disturbances of water flow and above all a substantial number of fish deaths as the result of asphyxiation’ and that ‘the excessive presence of plants gives rise to nuisances with respect to aesthetics, odour and the use of small craft and clogs the filters used in the production of drinking water’.

59It is also clear that the watercourses of the Artois-Picardy basin are put at a disadvantage in relation to those of other regions because, first, ‘industrial and household pressures are greater (population density three times higher than the national average)’ and, secondly, ‘the flow rates of the watercourses are too weak to drain all the pollution produced’ and ‘[their] runoff speeds … are slow: low oxygenation, silting, no fish reproduction and a reduction in the abundance of fauna’.

60The French Government nevertheless contends that no impact on water flow or damage to aquatic flora and fauna, and in particular to fish-breeding populations, has been observed in the watercourses of the Artois-Picardy basin. It maintains that the documents cited by the Commission were intended for the general public and were drafted with the aim of being accessible and therefore do not contain all the nuances to be desired, so that they cannot prove the Commission’s allegations.

61In that regard, it should be pointed out that while one of the documents referred to in paragraphs 58 and 59 above specifies that the lagoons of the upper Somme and the canals of the Aa river delta suffer from eutrophication, it defines that term as ‘enrichment in nutrients … which can lead to plant growth’, so that it is not possible to tell from that document whether the waters referred to satisfy the third and fourth criteria for eutrophication.

62As to the other documents, they do not make it possible to establish what river or canal is eutrophic or is likely to become so. Moreover, they do not always distinguish between the specific results of possible eutrophication of the hydrographic network and the effects of pollution, in general, which goes beyond nutrient inputs.

63As regards the ERM report of 1999, cited in the letter of formal notice and the reasoned opinion, which appear to be the main basis for the Commission’s finding of a failure to identify part of that hydrographic network, it must be stated that the part of that report which relates to the Artois-Picardy basin was not provided to the Court.

Therefore, in the light of the documents which the Commission has produced, nothing justifies its having included certain watercourses in the Artois-Picardy basin rather than others in its complaint. Moreover, it has not invoked in support of its first complaint any of the documents relating to the hydrographic network of that basin produced by the French Government in the course of these proceedings.

65Accordingly, the Commission has not established that the continental waters of the Artois-Picardy basin, as specified in its application, are eutrophic or in the near future may become eutrophic within the meaning of Directive 91/271.

The Loire-Brittany basin

– Vilaine bay

66The Ifremer report of 2001 indicates that Vilaine bay is the most eutrophic on the French coast. First, it is the site of serious hypoxia phenomena, even anoxia, resulting from the development, and subsequent bacterial deterioration, of a large phytoplankton biomass, which can bring about large-scale deaths of fish and benthic invertebrates. Secondly, three areas in that bay have been classified among potential sites of macroalgal bloom (‘green tides’) and have experienced that phenomenon at least once between 1997 and 1999, the period covered by the study.

67The French Government does not dispute that nutrient inputs, in particular nitrogen, from urban sources transported by the Vilaine river play an important role in eutrophication of the bay.

68It maintains that it has already classified the Vilaine catchment basin as an area sensitive to eutrophication, so that all agglomerations with a p.e. of more than 10 000 which discharge their effluent into that basin are subject to the provisions of Directive 91/271. The identification of Vilaine bay as an area sensitive to eutrophication is of no importance, inasmuch as no agglomeration with a p.e. of more than 10 000 discharges directly into that bay and, contrary to what the Commission maintains, fluvial inputs from the Loire would not have any influence on that bay, so that the French Government takes the view that it has not failed to fulfil its obligations.

69In that regard, even if no agglomeration with a p.e. of more than 10 000 discharges directly into Vilaine bay and, contrary to what the Commission maintains, fluvial inputs from the Loire do not have any influence on that bay, the fact that the catchment basin of the Vilaine river has already been identified as an area sensitive to eutrophication does not warrant not also classifying that bay as such. It follows from Article 5(1) of Directive 91/271, in conjunction with Annex II.A(a), that Member States are required to identify as sensitive areas all eutrophic water bodies.

70Therefore, by failing to identify Vilaine bay as an area sensitive to eutrophication within the meaning of Directive 91/271, the French Republic has failed to fulfil its obligations.

– The Lorient roadstead

71The French Government does not deny that the waters of the Lorient roadstead are enriched with nutrients.

72The Ifremer report of 2001 indicates that from 1997 to 1999 two areas in the Lorient roadstead experienced annual macroalgal blooms (‘green tides’) along the beaches.

73The same report points out that the green tides of the Brittany coast, which generally last from May to August-September, are caused by a rapid proliferation of green Ulva algae following the enrichment of the water by nutrients. Those opportunistic algae are easily torn from their substrate, following which they drift about and end by washing up on beaches, often covering them to some depth. Green tides strongly disturb or even render impossible normal tourist activities such as bathing, fishing, hiking along the coast, etc. Communes must collect the algae in order to maintain tourist activity.

74As pointed out in paragraph 23 above, such a proliferation of macroalgae constitutes an undesirable disturbance of the balance of organisms present in the water. The negative effects of the green tides which result from these, inter alia on tourist activities, also constitute a deterioration of the quality of the water.

75The French Government nevertheless maintains that the portion of spring and summer fluxes of nitrogen from urban sources is only 9.8%, so that discharges of urban waste water are not significant. It contends that the Commission admitted in its reasoned opinion that the nitrogen flux of urban origin in the Saint-Brieuc bay, which represents 8.9% of the total, is not significant, and that this is also the obvious conclusion as regards the Lorient roadstead.

76In that regard, the fact that the Commission admits that discharges from urban sources do not significantly contribute to eutrophication of the Saint-Brieuc roadstead is irrelevant to the identification of the Lorient roadstead as a sensitive area, since it is not in dispute that those two water bodies are independent of one another.

77The ERM report of 1999 produced by the Commission indicates that 9.8% of the spring and summer nitrogen inputs into the Lorient roadstead, even in the period of green algal blooms, are of urban origin, which amounts to 374 tonnes. Under those conditions, the Commission is right to conclude that urban waste water discharges contribute significantly to eutrophication of the waters of the Lorient roadstead.

78Accordingly, the Commission rightly found that the Lorient roadstead is eutrophic within the meaning of Directive 91/271 and that it should have been identified as an area sensitive to eutrophication.

– The Elorn estuary, the Gulf of Morbihan, Douarnenez bay and Concarneau bay

79The French Government does not deny the nutrient enrichment of those water bodies.

80The Ifremer report of 2001 indicates that from 1997 to 1999, the period covered by the study, the areas in question experienced annual green tides. The French Government also acknowledges the existence and importance of the phenomenon in Concarneau bay.

81For the reasons set out in paragraphs 73 and 74 above, the Commission has thus found that the Elorn estuary, the Gulf of Morbihan and Douarnenez and Concarneau bays are eutrophic.

82The French Government nevertheless contends that nutrient inputs from urban sources do not significantly contribute to the eutrophication of those water bodies, so that there is no need to identify them as sensitive areas within the meaning of Directive 91/271.

83In that regard, it is common ground that the origin of nitrogenous pollution is principally agricultural.

84However, as regards the Elorn estuary, the Commission and the French Government agree that 21% of the spring and summer inputs of nitrates, even in the period of green algae proliferation, are of urban origin, a figure provided by the ERM report of 1999.

85As regards the Douarnenez and Concarneau bays, the portion of the spring and summer inputs of nitrates which come from urban sources is, according to the same report, 23% and 32%, respectively. After stating in its reply to the reasoned opinion that, according to a study by the Bureau d’études Saunier of August 1993 (hereinafter ‘the Saunier study’), that portion was 22% and 34%, respectively, the French Government submitted in its defence that 90% of the nitrogen and phosphorus supply in Douarnenez bay is of agricultural origin, on the basis of a CEVA-Ifremer study for the Water Analysis Centre. Nevertheless, it must be noted that it did not produce that study. As for Concarneau bay, the French Government states that various studies and measurement efforts (Ifremer, CEVA, DDE, In vivo) have made it possible to estimate inputs of nutrients into the bay as about 500 tonnes annually, of which only 6.5 tonnes (1.3%) come from the waste water treatment plant at Concarneau. Again, however, it did not produce those studies and reports. Under those conditions, the percentages which result from the 1999 ERM report produced by the Commission must be accepted as the basis for analysing percentages.

86As regards the Gulf of Morbihan, the French Government contends that under the Saunier study, which it produced, only a maximum of 10% of spring and summer inputs of nitrates is from urban sources. However, examination of that study does not confirm that figure, so that the figure of 21% given by the 1999 ERM report must also be accepted. In any event, it must be pointed out that the Saunier study dates from 1993, so that the 1999 ERM report provides a more recent assessment of the state of French coastal waters.

87The Commission rightly considers that the inputs from urban sources which account for between 21% and 32% of total nitrogen inputs during the period of accelerated growth of algae and other higher forms of plant life are significant in the appearance, development and continuance of eutrophication of the receiving waters in question.

88Under those conditions, the Commission rightly found that the Elorn estuary, the Gulf of Morbihan, Douarnenez bay and Concarneau bay are eutrophic within the meaning of Directive 91/271 and that they should have been identified as areas sensitive to eutrophication.

– The Sèvre niortaise

89In its reply, the Commission withdrew its first complaint as regards that area.

The Rhône-Mediterranean-Corsica basin

– The Vistre

90The Commission claims that the Vistre river is eutrophic downstream from Nîmes and should have been identified as an area sensitive to eutrophication.

91The French Government acknowledges that that complaint is well founded and states that the localised problem of the Vistre, which is related only to discharges from the agglomeration of Nîmes, will be dealt with by the connection, by 31 December 2005, of the entire agglomeration to the wastewater treatment plant of Nîmes-west, which has been expanded.

92Therefore, the French authorities should have identified the Vistre river downstream from Nîmes as an area sensitive to eutrophication.

– Thau lagoon

93The parties agree that the waters of Thau lagoon are enriched by nutrients. In addition, as indicated by the Ifremer report of 2001, ‘the main source of the eutrophication of Mediterranean ecosystems is not agriculture but discharges from urban sources’, which the French Government does not dispute as regards Thau lagoon.

94According to the same report, Thau lagoon is the site of significant anoxic phenomena, called ‘dystrophic episodes’ (anoxic crises), the activation of which is ‘probably linked to a deterioration of algae, abundant on the verges, accelerated by high temperatures’ and which render the waters toxic for the animals and plants which live there. Such phenomena occurred in 1975, 1982, 1983, 1987, 1990 and 1997.

95However, on the basis of a 1998 Ifremer study entitled ‘La crise anoxique du bassin de Thau de l’été 1997’ (‘The anoxic crisis in the Thau basin in summer 1997’, hereinafter ‘the 1998 Ifremer study’) and the Bulletin of the lagoon monitoring network for the year 2000, published by Ifremer and the Languedoc-Roussillon region, the French Government maintains that the trophic state of the Thau lagoon has improved considerably since the 1970s. The anoxic crises observed during the past 20 years are no longer caused by plant proliferation resulting from eutrophication of the lagoon but by the still imperfect management of stocks of living and detrital organic matter produced, in particular, by the very substantial shellfish activity which has developed in Thau lagoon.

In that regard, it is clear from the 1998 Ifremer study that, following the planning undertaken on the lagoon’s perimeter since the 1970s in order to reduce nutrient inputs of anthropogenic origin, ‘one can consider that the Thau basin is no longer eutrophic’.

In fact, according to that study, while the waters of Thau lagoon experience significant phytoplankton production, those species of phytoplankton are not toxic and do not prevent shellfish culture, principally of oysters, with high growth rates. Moreover, the amount of nitrogenous material removed by harvesting (mussels, oysters, etc.) represents over 60% of inputs from the catchment basin. Under those conditions, the waters of Thau lagoon are not at present experiencing an undesirable disturbance of the balance of the organisms present in the water.

However, the 1998 Ifremer study points to the risk that the waters of Thau lagoon could be affected by dystrophic episode, the effects of which are anoxia, sulphide production and large-scale death of all living entities in the affected areas, including oysters. The last dystrophic episode occurred in 1997. When it takes place, that phenomenon constitutes both an undesirable disturbance of the balance of the organisms present in the water and a deterioration in the quality of the water.

Contrary to the contention of the French Government, it is clear from the 1998 Ifremer study that even if inputs of organic material resulting from shellfish activity contribute to the development of dystrophic episodes, as occurred in 1997, the development of macrophytes at the edges of the lagoon as the result of enrichment of the water by nutrients plays an important role in the appearance of those phenomena.

According to the same study, the appearance of dystrophic episodes in future cannot be excluded under unusual weather conditions such as those during the 1997 crisis. On the banks of the Thau lagoon there are ‘a certain number of potential sources in the areas located at the entrance of the main water courses fed, inter alia, by lagoon waters’. That is confirmed by the Bulletin of the lagoon monitoring network for the year 2000, according to which the quality of part of Thau lagoon (the Angle creek) is average as regards eutrophication.

Accordingly, the Commission was right to find that Thau lagoon may become eutrophic in the near future if protective action is not taken and that it ought to have been identified as an area sensitive to eutrophication within the meaning of Directive 91/271.

According to the Ifremer report of 1998, ‘inputs from the catchment basin are … necessary to maintain the Thau basin’s capacity to support shellfish farming’, because ‘a decrease in plankton production [would be] likely to lead to a decrease in the shellfish population’ which is plainly not desirable. However, the second paragraph of Annex II.A(a) provides for the possibility of making adjustments to the more stringent treatment usually applied to urban waste water discharged into sensitive areas.

In the light of all the foregoing considerations, the first complaint is well founded in so far as it relates to the Seine bay, the Seine downstream of its confluence with the Andelle, the coastal waters of the Artois-Picardy basin, Vilaine bay, the Lorient roadstead, Elorn estuary, Douarnenez bay, Concarneau bay, the Gulf of Morbihan, the Vistre downstream from Nîmes and the Thau lagoon.

The second complaint, alleging failure to subject to more stringent treatment discharges into sensitive areas of urban waste water from agglomerations with a p.e. of more than 10 000

Pursuant to Article 5(2) of Directive 91/271, the French authorities were required to take the necessary action, by 31 December 1998 at the latest, to ensure that before its discharge into sensitive areas urban waste water entering collecting systems from agglomerations with a p.e. of more than 10 000 is subject to more stringent treatment than that described in Article 4 of that directive.

Under Article 5(3), in conjunction with Annex I.B(3), of Directive 91/271 more stringent treatment means, inter alia, that discharges into areas sensitive to eutrophication must satisfy the requirements shown in Table 2 of that Annex, subject, however, to the provisions of the second paragraph of Annex II.A(a) of that directive.

First of all, the Commission submits that, in response to the letter of formal notice, the French Government acknowledged, by letter of 12 December 2000, that on 31 December 1998 the treatment of urban waste water in 130 agglomerations, of which it provided a list, did not comply with the requirements of Article 5(2) of Directive 91/271.

In its rejoinder, the French Government states that of the 130 agglomerations on that list, 32 now comply with the requirements of Directive 91/271 and 10 of those (Vichy, Aix-en-Provence, Mâcon, Créhange, Saint-Avold, Bailleul, Aurillac, Montauban, Châtillon-sur-Seine and Gray) did so before the end of the period laid down in the reasoned opinion.

In that regard, it is settled case-law that the question whether a Member State has failed to fulfil its obligations must be determined by reference to the situation prevailing in the Member State at the end of the period laid down in the reasoned opinion (see, inter alia, Case C-446/01 Commission v Spain [2003] ECR I-6053, paragraph 15).

Since the Vichy, Aix-en-Provence, Mâcon, Créhange, Saint-Avold, Bailleul, Aurillac, Montauban, Châtillon-sur-Seine and Gray agglomerations were brought into compliance with the requirements before the end of the period laid down in the reasoned opinion, the complaint is unfounded in relation to them.

On the other hand, it is well founded in so far as concerns the other agglomerations referred to in the French authorities’ letter of 12 December 2000, including those that were brought into compliance after the end of the period laid down in the reasoned opinion.

The Commission goes on to contend that the French authorities failed to fulfil their obligations with regard to the Montpellier agglomeration, which does not appear on the list attached to the letter of 12 December 2000.

The French Government’s reply to the reasoned opinion indicates that the Montpellier agglomeration discharges its urban waste water into a sensitive area and that the measures to bring the waste water treatment plant into compliance and to create an offshore outfall were not completed until 2004. Since the French Government has not argued before the Court that those measures were completed earlier than expected, or, in any event, before the end of the period laid down in the reasoned opinion, the second complaint is also well founded in so far as it concerns the Montpellier agglomeration.

Finally, the Commission claims that the French authorities ought to have ensured that the urban waste water from agglomerations with a p.e. of more than 10 000 discharged into the areas referred to in the first complaint, which ought to have been identified as areas sensitive to eutrophication, is subject to more stringent treatment, as required by Article 5(2) of Directive 91/271.

The French Government, which does not dispute that urban waste water from agglomerations with a p.e. of more than 10 000 is discharged into the areas referred to in paragraph 103 above or into their catchment basins, has neither submitted, nor, a fortiori, established that at the end of the period laid down in the reasoned opinion that water was subject to more stringent treatment within the meaning of Article 5(2) of Directive 91/271.

It must therefore be held that, by having failed:

to identify the Seine bay, the Seine downstream of its confluence with the Andelle, the coastal waters of the Artois-Picardy basin, Vilaine bay, the Lorient roadstead, Elorn estuary, Douarnenez bay, Concarneau bay, the Gulf of Morbihan, the Vistre downstream from Nîmes and the Thau lagoon as sensitive areas with respect to eutrophication, and

to subject to more stringent treatment discharges of urban waste water from the agglomerations – except for Vichy, Aix-en-Provence, Mâcon, Créhange, Saint-Avold, Bailleul, Aurillac, Montauban, Châtillon-sur-Seine and Gray – referred to in the French authorities’ letter of 12 December 2000 and from the Montpellier agglomeration, and to subject to more stringent treatment discharges of urban waste water from agglomerations with a population equivalent (p.e.) of more than 10 000 into the Seine bay, the Seine downstream of its confluence with the Andelle, the coastal waters of the Artois-Picardy basin, Vilaine bay, the Lorient roadstead, Elorn estuary, Douarnenez bay, Concarneau bay, the Gulf of Morbihan, the Vistre downstream from Nîmes and Thau lagoon,

the French Republic has failed to fulfil its obligations pursuant to Article 5(1) and (2) of, and Annex II to, Directive 91/271.

The remainder of the action is dismissed.

Costs

Under Article 69(2) of the Rules of Procedure, the unsuccessful party is to be ordered to pay the costs if they have been applied for in the successful party’s pleadings. Since the Commission has applied for costs and the French Republic has been unsuccessful, the French Republic must be ordered to pay the costs.

On those grounds, the Court (Second Chamber) hereby:

Declares that, by having failed:

to identify the Seine bay, the Seine downstream of its confluence with the Andelle, the coastal waters of the Artois-Picardy basin, Vilaine bay, the Lorient roadstead, Elorn estuary, Douarnenez bay, Concarneau bay, the Gulf of Morbihan, the Vistre downstream from Nîmes and the Thau lagoon as sensitive areas with respect to eutrophication, and

to subject to more stringent treatment discharges of urban waste water from the agglomerations – except for Vichy, Aix-en-Provence, Mâcon, Créhange, Saint-Avold, Bailleul, Aurillac, Montauban, Châtillon-sur-Seine and Gray – referred to in the French authorities’ letter of 12 December 2000 and from the Montpellier agglomeration, and to subject to more stringent treatment discharges of urban waste water from agglomerations with a population equivalent (p.e.) of more than 10 000 into the Seine bay, the Seine downstream of its confluence with the Andelle, the coastal waters of the Artois-Picardy basin, Vilaine bay, the Lorient roadstead, Elorn estuary, Douarnenez bay, Concarneau bay, the Gulf of Morbihan, the Vistre downstream from Nîmes and Thau lagoon,

the French Republic has failed to fulfil its obligations pursuant to Article 5(1) and (2) of, and Annex II to, Council Directive 91/271/EEC of 21 May 1991 concerning urban waste water treatment;

Dismisses the remainder of the action;

Orders the French Republic to pay the costs.

Signatures.

Language of the case: French.