Opinion of Advocate General Medina delivered on 18 December 2025.#F.B. v Région wallonne.#Request for a preliminary ruling from the Conseil d'État.#Reference for a preliminary ruling – Environment – Aarhus Convention – Article 6 – Public participation in decisions on specific activities – Extension of the duration of the validity of a permit to operate a wind farm – Obligation to organise a public participation phase prior to that extension.#Case C-151/25.

1.

The Aarhus Convention ( 2 ) has been famously praised as ‘the most ambitious venture in the field of environmental democracy under the auspices of the United Nations’. ( 3 ) In the Lucca Declaration, adopted at the First Meeting of the Parties to the Aarhus Convention, it is described as ‘a breakthrough in participatory democracy’. ( 4 )

2.

The Aarhus Convention stands on three pillars: access to information, public participation in decision-making and access to justice, each implementing one of three environmental procedural rights. ( 5 ) Among those three rights, the ‘most overtly democratic’ ( 6 ) is the right of the public to participate in environmental decision-making. That right contributes to one of the objectives of the Aarhus Convention, namely, as stated in its tenth recital, to further government accountability and transparency and to strengthen public support for decisions on the environment. ( 7 )

3.

The present case raises the issue of whether a decision to extend for 10 years an environmental permit for an activity which comes within the scope of Article 6(1)(a) of the Aarhus Convention requires a public participation phase and whether that article as a whole precludes national legislation which does not provide for public participation for such an extension. The case provides the Court with the opportunity to interpret Article 6(10) of the Aarhus Convention, according to which, the public participation requirements laid down in paragraphs 2 to 9 of Article 6 apply mutatis mutandis, and where appropriate, when a public authority reconsiders or updates the operating conditions for an activity referred to in paragraph 1. More particularly, it will address the issue of whether the extension of the duration of an activity which falls under Article 6(1)(a) must be regarded as a reconsideration or update of the operating conditions for the activity in question and therefore requires public participation as considered appropriate.

4.

Article 6 of the Aarhus Convention, entitled ‘Public participation in decisions on specific activities’, provides in paragraphs 1 and 10:

‘1.   Each Party:

…

10.   Each Party shall ensure that, when a public authority reconsiders or updates the operating conditions for an activity referred to in paragraph 1, the provisions of paragraphs 2 to 9 of this article are applied mutatis mutandis, and where appropriate.’

5.

Annex I to the Aarhus Convention contains a list of activities referred to in Article 6(1)(a) thereof. Paragraphs 20 and 22 of that annex are worded as follows:

‘20.   Any activity not covered by paragraphs 1 to 19 above where public participation is provided for under an environmental impact assessment procedure in accordance with national legislation.

…

22.   Any change to or extension of activities, where such a change or extension in itself meets the criteria/thresholds set out in this annex, shall be subject to Article 6(1)(a) of this Convention. Any other change or extension of activities shall be subject to Article 6(1)(b) of this Convention.’

6.

Article (2)(1) 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) (‘the EIA Directive’) provides:

‘Member States shall adopt all measures necessary to ensure that, before 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. Those projects are defined in Article 4.’

7.

Article 4(1) and (2) of the EIA Directive states:

‘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.

2.   Subject to Article 2(4), for projects listed in Annex II, Member States shall determine whether the project shall be made subject to an assessment in accordance with Articles 5 to 10. …

8.

Annex II to the EIA Directive lists the projects referred to in Article 4(2) thereof. Title 3 of that annex, entitled ‘Energy industry’, includes point (i):

‘Installations for the harnessing of wind power for energy production (wind farms);’.

9.

By complementing the first sentence of article 50(1) of the décret relatif au permis d’environnement (Decree on Environmental Permits) of 11 March 1999 (Moniteur belge of 8 June 1999, p. 21114) (‘Decree on Environmental Permits), which provides for a maximum duration of 20 years for an environmental permit, Article 89 of the décret du 23 juin 2016 modifiant le Code de l’Environnement, le Code de l’Eau et divers décrets en matière de déchets et de permis d’environnement (Decree of 23 June 2016 amending the Environmental Code, the Water Code and various decrees on waste and environmental permits) (‘the Decree of 23 June 2016’) states that the maximum duration of a permit for a wind turbine is to be 30 years.

10.

According to the first paragraph of Article 109 of the Decree of 23 June 2016, the modification with regard to the 30-year maximum duration of an environmental permit for a wind turbine applies to applications made after the entry into force of that decree, namely after 1 August 2016. With regard to permits that were valid before 1 August 2016, it follows from the second paragraph of Article 109 of that decree that they may be extended once for a maximum period of 10 years.

11.

Those provisions are implemented by the arrêté du Gouvernement wallon du 20 avril 2017 modifiant l’arrêté du Gouvernement wallon du 4 juillet 2002 relatif à la procédure et à diverses mesures d’exécution du décret du 11 mars 1999 relatif au permis d’environnement et portant exécution des articles 108 et 109 du décret du 23 juin 2016 modifiant le Code de l’Environnement, le Code de l’Eau et divers décrets en matière de déchets et de permis d’environnement (Decision of the Walloon Government of 20 April 2017 amending the Decision of the Walloon Government of 4 July 2002 on the procedure and on various measures implementing the [Decree on environmental permits] and implementing Articles 108 and 109 of the [Decree of 23 June 2016]) (‘the Decision of 20 April 2017’).

12.

The provisions referred to in points 10 and 11 above do not entail public participation in the relevant decision-making process.

13.

On 28 August 2009, the limited liability company Parc éolien de Leuze-en-Hainaut (PELZ) SA was granted an initial single permit ( 8 ) for the construction and operation of a wind farm comprising 10 wind turbines in the commune of Leuze-en-Hainaut (Belgium) (‘the wind farm’). On the basis of that permit, the wind farm was constructed and put into operation. The permit was annulled on 16 April 2014 by the Conseil d’État (Council of State, Belgium) and, after further examination, a new permit was issued on 8 September 2014, which in turn was annulled on 25 January 2017. Finally, after re-examination, a new permit was granted on 6 June 2017 for a period of 20 years, from 28 August 2009 to 28 August 2029.

14.

On 2 April 2020, at the request of one of the wind farm operators, a technical officer issued a decision extending the duration of the permit of 6 June 2017 (in respect of the part relating to the environmental permit) for 10 years, that is, until 28 August 2039 (‘the contested decision’).

15.

F.B., the applicant in the main proceedings and a resident of the area where the wind farm is located, seeks annulment of the contested decision before the referring court.

16.

The defendant in the main proceedings is the Région wallonne (Walloon region). The companies Parc éolien de Leuze-en-Hainaut, e-NosVents SA and Electrabel SA were admitted as interveners in the proceedings.

17.

In his application, F.B. raises a plea alleging, inter alia, infringement of Article 6(10) of the Aarhus Convention, claiming that the authorised wind farm falls within the scope of Article 6(1)(a) of that convention. He submits that the decision to change its operating conditions should have been preceded by a public participation phase. The failure to have such a procedure renders the contested decision unlawful.

18.

The defendant argues that, in the light of the definition of the terms ‘project’ and ‘development consent’ in Article 1(2)(a) and (c) of the EIA Directive, respectively, the contested decision, which merely extends the duration of the environmental permit, is not a decision authorising a project.

19.

The interveners in the main proceedings submit that the extension of the duration of a single permit under the second paragraph of Article 109 of the Decree of 23 June 2016 does not fall within the scope of Annex I to the Aarhus Convention. They argue that neither that provision nor its implementation by the Decision of 20 April 2017 requires that the extension of the duration of wind farm permits granted before 1 August 2016 be subject to an environmental impact assessment (EIA). That circumstance precludes the application of Article 6(10) of the Aarhus Convention.

20.

The applicant responded that the EIA Directive is irrelevant because he is not alleging an infringement of that directive. He argued that where the decision-making process for an activity includes a public participation phase under Article 6(1)(a) of the Aarhus Convention, any procedure by which a public authority subsequently reconsiders or updates the operating conditions under which the activity is carried out should include such a phase. By failing to require a public participation phase in the decision-making process, the administration failed to exercise its discretion.

21.

The applicant also rejects the plea raised by the defendant and the interveners that his action was lodged out of time, submitting that the contested decision should have given rise to a public consultation, and therefore to notification under Article D.29-22(2) of Book I of the Code de l’Environnement (Environmental Code) for the purposes of determining the time limit for bringing an action.

22.

The referring court notes that the Decision of 20 April 2017 was preceded by an opinion of the legislative section of the Conseil d’État (Council of State). According to that opinion, a decision to extend the period of a permit granted for an activity listed in Annex I to the Aarhus Convention – or that is considered to have a potentially significant effect on the environment – changes the conditions under which the activity is carried out and falls within the scope of Article 6(10) of that convention. That opinion therefore concluded that the decision in question must be subject to public participation in accordance with Article 6(2) to (9) of the Aarhus Convention.

23.

However, the Walloon Government did not follow that opinion. The absence of a requirement to conduct public participation was, in its view, justified, essentially by the need to avoid discrimination between the old permits (granted for a maximum of 20 years) and the new permits (granted for a maximum of 30 years). Another justification was that the public had already expressed its views on the project, regardless of its duration, and that the conditions under which the activity is carried out had not changed.

24.

The referring court points out that it is not disputed that the permit for the wind farm at issue falls within the scope of Article 6(1)(a) of the Aarhus Convention, read together with paragraph 20 of Annex I thereto. The question that arises is rather whether the contested decision, that is, to extend that permit, also requires a public participation phase.

25.

That would be the case if the decision is to extend a permit that can be classified as any one of the following:

26.

In those circumstances, the Conseil d’État (Council of State) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:

‘In a legal system in which the [exercise] of an activity referred to in Annex I to the Aarhus Convention requires an operation permit granted for a maximum period of 20 years[:]

27.

F.B., Electrabel, the Belgian Government and the European Commission submitted written observations.

28.

By its questions, the referring court asks, in essence, whether either Article 6(1) of the Aarhus Convention, read together with paragraphs 20 and 22 of Annex I thereto, or Article 6(10) of that convention must be interpreted as meaning that a public participation phase is required before the adoption of a decision to extend by 10 years the operation of a wind farm initially authorised for 20 years. It also asks whether those provisions preclude domestic legislation in which the decision-making process for carrying on the activity in question by 10 years does not involve a public participation phase.

29.

The referring court’s questions are raised in the context of an action for annulment of the contested decision brought by F.B., a resident in the area where the wind farm is located and who is criticising the failure to have a public participation phase.

30.

As a preliminary point, it should be borne in mind that the provisions of the Aarhus Convention – signed by the Community and subsequently approved by Council Decision 2005/370/EC ( 9 ) – form an integral part of the EU legal order. ( 10 ) Therefore, as the Commission observes in its written submissions, the European Union and the Member States must comply with the obligations stemming from the Aarhus Convention and, more specifically, with the obligations arising from Article 6 thereof on public participation.

31.

It is clear from the order for reference that the initial permit for the activity at issue (the wind farm) requires the organisation of public participation. This activity falls within the scope of Article 6(1)(a) of the Aarhus Convention, read together with paragraph 20 of Annex I to that convention. Indeed, that paragraph 20 extends the public participation requirements laid down in Article 6 of the Aarhus Convention to any activity for which national legislation provides for public participation under an EIA procedure, which is the case for the activity at issue in the main proceedings. ( 11 )

32.

That activity, for which an EIA is required under national law, falls within the scope of the EIA Directive. ( 12 ) Indeed, point (i) of Title 3 of Annex II of the EIA Directive lists ‘installations for the harnessing of wind power for energy production (wind farms)’ among the projects referred to in Article 4(2) of that directive, according to which Member States are to determine whether the project is to be made subject to an EIA.

33.

The contested decision extends the duration of the original permit for an activity for which public participation is required (under the EIA Directive and the Aarhus Convention, which forms an integral part of the EU legal order).

34.

However, the applicable legislation, on the basis of which the contested decision extending the duration of the activity at issue was adopted, does not provide for a public participation phase as a necessary condition for the relevant decision-making process.

35.

The question is therefore whether there should have been public participation for the extension of the duration of the activity at issue in accordance with the Aarhus Convention. ( 13 )

36.

The referring court considers three legal provisions that may apply to the renewal of a permit for an activity authorised under Article 6(1)(a) of the Aarhus Convention. The first is that provision, read together with paragraph 20 or paragraph 22 of Annex I to the Convention; the second is Article 6(1)(b) of the Convention; and the third is Article 6(10) thereof. Each of those provisions determines whether and under what conditions there is a requirement for a public participation phase.

37.

Two legal classifications can be applied to a decision to extend the duration of an authorised activity: a new decision to permit a proposed activity pursuant, on the one hand, to Article 6(1)(a) of the Aarhus Convention, read together with paragraph 20 of Annex I thereto or with paragraph 22 of that annex (proposed activity listed in Annex I), or, on the other hand, to Article 6(1)(b) of the Convention (proposed activity not listed in Annex I but having a significant effect on the environment). Under the second classification, that decision is a reconsideration or update of the operating conditions for an activity under Article 6(10) of that convention.

38.

Article 6 of the Aarhus Convention sets out the right of public participation in the decision-making process for specific activities.

39.

Points (a) and (b) of Article 6(1) together set out the criteria that determine which decisions must be subject to public participation. The two points are linked by the fact that they take account of the potentially significant impact of proposed activities on the environment. ( 14 ) Point (a) refers to the activities listed in Annex I, which are presumed to have a potentially significant effect on the environment, and point (b) provides that the public participation provisions also apply, in accordance with domestic legislation, to decisions on proposed activities not listed in Annex I, which may nevertheless have a significant effect on the environment.

40.

With regard to the possible application of that provision, F.B. submits, in essence, that the renewal of the permit for the activity at issue must be considered to be a new decision in relation to that activity. Since the original permit was granted under Article 6(1)(a) of the Aarhus Convention, read together with paragraph 20 of Annex I thereto, ( 15 ) the renewal of that permit, he argues, should be treated as a new decision and should thus give rise to public participation. Alternatively, the renewal could be regarded as an extension of or a change to that activity under paragraph 22 of that annex or as a decision in relation to an activity not listed therein but which may have a significant effect on the environment.

41.

Public participation applies, according to Article 6(1)(a) of the Aarhus Convention, to decisions on whether to permit the proposed activities listed in Annex I thereto. ( 16 )

42.

As already explained above, ( 17 ) paragraph 20 of Annex I to the Aarhus Convention extends Article 6 to any activity not covered by paragraphs 1 to 19 of that annex where, in accordance with national legislation, public participation is provided for under an EIA procedure. ( 18 )

43.

The determination of whether an activity falls within the ambit of paragraph 20 of Annex I to the Convention depends on three elements, namely (i) public participation; (ii) an EIA in the context of which public participation takes place; and (iii) domestic legislation providing for an EIA. ( 19 )

44.

Accordingly, if national legislation does not require an EIA for the granting or renewal of a permit, paragraph 20 of Annex I alone cannot establish such a requirement.

45.

The foregoing is confirmed by the findings of the Aarhus Convention Compliance Committee (the ‘Compliance Committee’) from which it follows that the decision to extend the duration of an activity does not come within the scope of paragraph 20 of Annex I to the Aarhus Convention if an EIA procedure is not required under national law for that renewal. ( 20 )

46.

In the case in the main proceedings, it is clear that national legislation provides for an EIA for the granting of the initial permit for a wind farm. However, as the Commission essentially observed in its written submissions, the renewal of that permit does not appear to require such an assessment.

47.

Therefore, the renewal of the permit at issue cannot be considered to fall within the scope of Article 6(1)(a) of the Aarhus Convention, read together with paragraph 20 of Annex I thereto.

48.

Paragraph 22 of Annex I to the Aarhus Convention broadens the scope of Article 6 of the Aarhus Convention to include any change to or extension of activities, where such a change or extension in itself meets the criteria or thresholds set out in that annex. Any other change or extension of activities not meeting the criteria or thresholds set out in the annex is subject to Article 6(1)(b) of the Convention.

49.

The issue is whether the term ‘change or extension’ is to be understood as encompassing a mere extension of the duration of an activity.

50.

Since the first sentence of paragraph 22 of Annex I to the Aarhus Convention is substantially similar to point 24 of Annex I to the EIA Directive, ( 21 ) it must be pointed out that, according to the Court’s case-law, ‘it is evident from the wording and general scheme of that provision that it applies to any change or extension to a project, which by virtue of, inter alia, its nature or scale, presents risks that are similar, in terms of their effects on the environment, to those posed by the project itself’. ( 22 )

51.

The Court ruled that national measures which had the effect of extending, by a significant period of 10 years, the industrial production of electricity of nuclear power stations which had until that time been limited to 40 years, combined with major renovation works necessary due to the ageing of those power stations and the obligation to bring them into line with safety standards, were ‘of a scale that is comparable, in terms of the risk of environmental effects, to that when those power stations were first put into service’. ( 23 )

52.

On the basis of that case-law, and as the Commission essentially claimed in its written submissions, it can be argued that, in the absence of any works and physical changes, the mere extension of the duration of a permit for an activity already existing, such as that in the main proceedings, does not qualify as a change to or extension of an activity.

53.

The Court’s judgment in FCC Česká republika, ( 24 ) decided in the context of Directive 2010/75, which implements public participation requirements in the field of industrial emissions, corroborates that interpretation. In the context of that directive, the term ‘extension’ forms part of the definition of ‘substantial change’ set out in Article 3(9) of Directive 2010/75. The grant of a permit for any ‘substantial change’ is subject to public participation pursuant to Article 24(1)(b) of Directive 2010/75. ‘Substantial change’ is defined as a ‘change in the nature or functioning, or an extension, of an installation … which may have significant negative effects on human health or the environment’ (emphasis added).

54.

The Court has ruled that ‘the mere extension of the duration of waste disposal at a landfill does not, in itself, change the perimeter of the installation or the storage capacity as provided for in the initial permit, and does not therefore constitute an “extension” of the installation’. ( 25 )

55.

The Aarhus Convention Implementation Guide – which, according to the settled case-law of the Court, may be regarded as an explanatory document, capable of being taken into consideration if appropriate among other relevant material for the purpose of interpreting that convention, even if the observations in the guide have no binding force and do not have the normative effect of the provisions of the Convention ( 26 ) – confirms the interpretation according to which paragraph 22 of Annex I to the Convention concerns only physical changes or extensions to activities. ( 27 )

56.

In the case of subsequent administrative procedures, where they relate to proposed activities covered by Article 6(1) of the Aarhus Convention, it is not that provision that applies, together with paragraph 22 of Annex I thereto, but Article 6(10) thereof. ( 28 )

57.

Therefore, the mere renewal of the permit in the case in the main proceedings, which does not involve any physical change or extension to the activity at issue, cannot be qualified as a new decision. However, as I will explain in Part B below, that is so without prejudice to the public’s right to participate on the basis of another provision, namely Article 6(10) of the Aarhus Convention, which governs reconsiderations and updates of activities.

58.

Article 6(1)(b) of the Aarhus Convention states that the provisions of Article 6 of the Convention concerning public participation in decisions on specific activities are to apply to decisions on proposed activities not listed in Annex I to that convention which may have a significant effect on the environment.

59.

It follows from the wording of Article 6(1)(b) that the Parties to the Aarhus Convention determine whether the public participation requirements apply where the proposed activity may have a significant effect on the environment. ( 29 )

60.

With regard to the extension in the duration of the activity at issue, as the Commission pointed out in essence in its written submissions, there is insufficient evidence and information in the file before the Court to determine whether that extension can be considered to be a proposed activity which may have a significant effect on the environment.

61.

It must also be pointed out that paragraph 22 of Annex I to the Aarhus Convention broadens the scope of Article 6(1)(b) thereof to any change to or extension of activities where such a change or extension does not in itself meet the criteria or thresholds set out in that annex.

62.

However, it follows from the analysis in the previous section ( 30 ) that the change to or extension of the activity under that paragraph 22 is to be understood as a physical change or extension, so that the mere renewal of a permit – an extension of its duration with no physical alterations or work involved – is not classified as such a change or extension.

63.

Under those circumstances, the renewal of the permit at issue does not appear to be a decision falling within the scope of Article 6(1)(b) of the Aarhus Convention, read together with paragraph 22 of Annex I thereto.

64.

Article 6(10) of the Aarhus Convention requires the application of the public participation requirements ‘mutatis mutandis, and where appropriate’, when a public authority ‘reconsiders or updates the operating conditions’ for an activity that was permitted under paragraph 1 of that provision.

65.

Article 6(10) ‘supplements’ ( 31 ) paragraph 22 of Annex I to the Aarhus Convention. While that paragraph 22 concerns physical changes to or extensions of activities, Article 6(10) extends public participation requirements to reconsiderations or updates of the operating conditions for an activity, which includes any administrative reconsideration or update which does not necessarily involve a physical change to the activity. ( 32 )

66.

The application of Article 6(10) is triggered by the reconsideration or update of the operating conditions for an activity. As the term itself indicates, ‘operating conditions’ are all those conditions that are required so that an activity can carry on. ( 33 ) The term ‘reconsiders or updates’ is broad enough to cover the environmental decision-making subsequent to the initial permit and which brings about a change to the operating conditions.

67.

By its broad formulation, Article 6(10) captures the life cycle of the activity, in so far as matters falling within the scope of the Aarhus Convention are concerned. That provision helps to ensure the ongoing achievement of the objective of public participation, which, as stated in the ninth recital of the Aarhus Convention, is to give the public the opportunity to express its concerns and enable public authorities to take due account of those concerns.

68.

The foregoing is borne out by the nature of certain activities listed in Annex I to the Aarhus Convention which involve the use of natural resources. As explained in legal doctrine, the relevant permits in most countries ‘are granted only for a limited period of time (usually up to 10 years) and thereafter need to be renewed and/or updated’ due to ‘the fact that the amount of a resource to be used and conditions for this use heavily depend on the state of the natural resource in question’. ( 34 )

69.

Article 6(10) of that convention provides for the application of paragraphs 2 to 9 of that article on public participation ‘mutatis mutandis, and where appropriate’. The reference to the ‘mutatis mutandis’ application of the public participation requirements in Article 6(10) simply means ‘with the necessary changes’. ( 35 ) With regard to the appropriateness of public participation, although the expression ‘where appropriate’ implies ‘some discretion’, it ‘does not imply complete discretion’. ( 36 ) Rather, that clause ‘introduces an objective criterion to be seen in the context of the goals of the Convention’. ( 37 )

70.

The appropriateness of public participation, in the event of a reconsideration or update of the operating conditions of the activity, relates to the significance of the effects of that reconsideration or update on the environment. Indeed, when determining whether a proposed activity should be permitted, account is taken of the potentially significant impact on the environment, ( 38 ) which remains relevant at the subsequent stages of environmental decision-making.

71.

The foregoing is confirmed by the findings of the Compliance Committee, which has emphasised that, when determining whether it will be ‘appropriate’, and thus required, to have a public participation phase, when a public authority reconsiders or updates the operating conditions of an activity subject to Article 6, ‘some kind of significance test’ applies. ( 39 )

72.

The expression ‘where appropriate’ must be applied in such a manner as to preserve the meaningful effect of Article 6(10) of the Aarhus Convention. The requirement to have a public participation phase would be deprived of all useful effect if the domestic legislative framework does not envisage any possibility of assessing the appropriateness of having a public participation phase in the event of the reconsideration or update of activities.

73.

That was precisely the issue in the case which gave rise to the findings of the Compliance Committee concerning the European Union in relation to Directive 2010/75. ( 40 ) The Compliance Committee found that the European Union, in its capacity as a Party to the Aarhus Convention, failed to comply with Article 6(10) thereof ‘by putting in place a legal framework that does not envisage any possibility for public participation in relation to reconsiderations and updates’ under a number of provisions of that directive, as applicable at the time of those findings. ( 41 )

74.

It is important to note that in order to comply with the Aarhus Convention, Directive 2010/75 was amended to specify that ‘the members of the public concerned should be given early and effective opportunities to participate in the granting or updating of permit conditions set by the competent authority also when permit conditions are reconsidered …’. ( 42 )

75.

Article 6(10) of the Aarhus Convention applies in the event of reconsideration or update of the operating conditions of an activity, that is, all the conditions necessary for the ongoing operation of the activity. ( 43 ) The permitted duration of an activity is necessary for the ongoing operation of that activity and forms part of those operating conditions. ( 44 )

76.

Therefore, a decision which prolongs the duration of an activity modifies its operating conditions and in turn triggers the application of Article 6(10) of the Convention.

77.

I cannot agree with the Belgian Government’s submission that Article 6(10) does not apply because there was no modification of the original conditions under which the activity at issue was exercised; that absence does not alter the fact that the initial, total duration of 20 years was extended by half, bringing about a change in the initial operating conditions. ( 45 )

78.

With regard to the appropriateness of organising public participation, as already pointed out, the authorities enjoy a margin of discretion which must, however, be exercised in accordance with the objectives of the Aarhus Convention. ( 46 )

79.

As regards renewal of the permit, there is no ‘arithmetic’ threshold, fixed by that convention, above which it is appropriate to conduct public participation. That determination has to be made on the basis of substantive criteria. The appropriateness of public participation in the event of the renewal of a permit and the assessment as to the significant effect on the environment may depend, inter alia, on the nature of the activity renewed and on the length of the extension. It is also important to take into account whether, in previous public participation phases, the public was informed of possible future extensions of the permit and therefore had the opportunity to comment on the associated effects on the environment. ( 47 )

80.

In any event, a significant extension of the initially permitted duration of an activity strongly indicates that it is appropriate to have a public participation phase. The foregoing is in line with the objective of public participation of providing the public with the opportunity to express its concerns. ( 48 )

81.

The Compliance Committee confirms that interpretation. It has repeatedly found that ‘except in cases where a change to the permitted duration is for a minimal time and obviously would have insignificant or no effects on the environment, it is appropriate for extensions of duration to be subject to the provisions of [A]rticle 6’ (emphasis added). ( 49 ) The extension of an activity’s duration by five years was found by the Compliance Committee to be ‘by no means minimal’, and therefore to require public participation. ( 50 )

82.

In the case in the main proceedings, the permit was extended by 10 years. A 10-year extension of an activity initially authorised for 20 years is an extension by half of its initial duration and cannot be considered to be ‘minimal’. Moreover, at the time the permit was extended (2020), more than 10 years had passed since the activity at issue was first put into operation (2009).

83.

Those factors constitute a strong indication that public participation is appropriate. Ultimately, however, it is for the national court to appraise those circumstances.

84.

The other issue raised in the order for reference is the absence in the national legislative framework of any possibility of public participation in relation to the renewal of a permit for a given activity.

85.

It follows from that order that one of the reasons why the national legislature made no provision for a public participation phase was that, when an operator applies for a permit, there is public participation, including an EIA, regardless of the duration of the permit granted. Another reason was to avoid discriminating between the new permits for wind farms (granted for a maximum duration of 30 years) and the permits granted under the previous regime (granted for a maximum duration of 20 years).

86.

I am not persuaded that those reasons justify the legislature excluding the renewal of permits from the scope of Article 6(10) of the Aarhus Convention. First, the application of that provision does not depend on whether the initial permit was preceded by public participation. The provision applies in all situations in which the operating conditions of an activity are ‘reconsidered or updated’ and requires the authority concerned to assess whether public participation is ‘appropriate’. Although the expression ‘where appropriate’ leaves a margin of discretion to public authorities, exercise of that discretion cannot be waived completely merely because public participation took place in the past on matters unrelated to the reconsideration or update of the operating conditions. Were that not to be the case, Article 6(10) would be deprived of meaningful effect. Indeed, all activities for which public participation has taken place (on matters other than the reconsideration or update of the operating conditions for the activity) would be automatically exempted.

87.

With regard to the activity at issue in the main proceedings, there have been successive stages of judicial cancellation and re-examination of the permit since the wind farm was put in operation. ( 51 ) It is not clear from the file before the Court whether public participation took place at each of those stages. In any event, there is no evidence that the public had the opportunity to express its views specifically on the matter of a possible significant extension of the duration of the permit granted. ( 52 )

88.

Second, as regards the argument that public participation leads to discrimination between the holders of old permits and those of new permits, I consider it important to recall that the application of Article 6(10) of the Aarhus Convention is not optional. Where the conditions for it to apply are met, the right to public participation must be safeguarded. ( 53 ) The appropriateness of public participation for a given activity must be determined in line with the goals of the Convention. ( 54 ) Public participation is not a mere box-ticking exercise or a simple formality; it is a means by which to achieve the environmental democracy goals pursued by that convention. ( 55 )

89.

Moreover, Article 6(10) of the Aarhus Convention applies to all operators irrespective of the point in time at which their activity is authorised. Accordingly, for those operators that were granted permits for 30 years, there might also be a public participation phase in further environmental decision-making when there is a change of or update to the operating conditions of their activity.

90.

It must also be clarified that the fact that an EIA was carried out when the permit was granted is not in itself decisive for the application of Article 6(10). That article, and the right to public participation in general under the Aarhus Convention, is not synonymous with an EIA. ( 56 ) As stated in the Aarhus Convention Implementation Guide, the scope of the second pillar of the Aarhus Convention is ‘different and rather broader than the scope of environmental assessment’. ( 57 ) That guide gives as an example precisely the reconsideration or update of the operating conditions of specific activities, which in many countries, unless related to a major change in the activity, is not necessarily subject to an EIA procedure but rather to environmental permitting. ( 58 )

91.

For those reasons, I consider that Article 6(10) precludes domestic legislation which does not include the obligation of the public authority to consider the appropriateness of public participation for the 10-year renewal of permits for the operation of wind farms.

92.

The case-law of the Court referred to above, ( 59 ) on the extension of the duration of the operation of a landfill in the context of Directive 2010/75, cannot lead to a different interpretation. In the judgment in FCC Česká republika, the Court ruled that the mere extension of the duration of waste disposal at a landfill, without any change in the maximum approved dimensions of the installation or its total capacity, does not constitute a ‘substantial change’ within the meaning of Article 3(9) of that directive. As a consequence, the operator of the landfill could not be obliged to apply for a new permit. The Court’s reasoning was based on the term ‘substantial change’, which requires, inter alia, an ‘extension’ of an installation.

93.

However, the scope of Article 6(10) of the Aarhus Convention does not depend on a ‘substantial change’ or on any physical extension of an activity; it applies in the event of a reconsideration or update of the operating conditions of an activity. As already pointed out above, ( 60 ) while paragraph 22 of Annex I to the Aarhus Convention, applies to physical changes to an activity, Article 6(10) applies to subsequent administrative procedures. ( 61 )

94.

In addition, Directive 2010/75 has been amended ( 62 ) since the judgment in FCC Česká republika in order to require public participation when a permit is updated at the request of the operator in order to extend the duration of the operation of a waste disposal landfill which reaches the thresholds set out in point 5.4 of Annex I to that directive.

95.

Therefore, the judgment in FCC Česká republika should not be understood, in my view, as an obstacle to the interpretation according to which the renewal for 10 years of the permit for a wind farm is an update of the operating conditions of that activity, which in turn triggers the application of Article 6(10) of the Aarhus Convention.

96.

In view of all of the above, Article 6(10) of the Aarhus Convention must be interpreted as requiring public authorities to assess the appropriateness of having a public participation phase in the event of the extension for 10 years of a permit for a wind farm initially authorised for 20 years, and as precluding a legal system in which the procedure for renewal of a permit for such an activity does not include the obligation of the public authority to consider the appropriateness of there being a public participation phase.

97.

In the light of the foregoing, I propose that the Court answer the questions referred by the Conseil d’État (Council of State, Belgium) as follows:

Article 6(10) of the Convention on Access to Information, Public Participation in Decision-making and Access to Justice in Environmental Matters

must be interpreted as requiring public authorities to assess the appropriateness of having a public participation phase in the event of the extension for 10 years of a permit for a wind farm initially authorised for 20 years, and as precluding a legal system in which the procedure for renewal of a permit for such an activity does not include the obligation of the public authority to consider the appropriateness of there being a public participation phase.