1.

In the present infringement proceedings the Commission objects to the infringement of EU ambient air quality standards in Bulgaria. To be more precise, the case concerns excessive levels of particulate matter in the order of up to 10 μm (PM10) under Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 on ambient air quality and cleaner air for Europe. ( 2 ) According to the European Environment Agency (EEA), Bulgaria has the worst levels of this pollutant of all the Member States. ( 3 )

2.

Air pollution has significant adverse effects on our health. Both the cardiovascular system and the respiratory channels suffer in particular as a result of PM10. ( 4 ) According to the World Health Organisation (WHO), 3 million premature deaths were attributable to ambient air pollution globally in 2012, 479000 of them in Europe, ( 5 ) including 8634 in Bulgaria. ( 6 ) According to this report, Bulgaria has the second highest mortality rate in the world in relation to population (118 per 100000 capita), behind Ukraine and in front of Belarus and China, although that rate is relativised if the respective age structures are taken into account. ( 7 )

3.

There do not appear to be any recent estimates specifically for PM10, but, according to the EEA in 2009, a figure of around 1600 premature deaths per million inhabitants was assumed in Bulgaria for 2005, which would be reduced to around 1000 in the case of compliance with limit values. On the other hand, the relevant estimates for the 27 Member States at the time were around only 850 and 650 premature deaths per million inhabitants. ( 8 )

4.

The present infringement proceedings are therefore of considerable importance for the protection of human health from negative environmental factors. Both parties agree that Bulgaria has failed to comply with the limit values since 2007, when they began to apply.

5.

However, the legal assessment of the present case is not straightforward. A question of fundamental importance is how the obligation to comply with the limit values relates to the fact that where they are exceeded, air quality plans must be established, which are not intended to create the necessary ambient air quality immediately but only to keep the exceedance period as short as possible.

6.

In addition, a number of questions specifically connected to this case arise, in particular whether the Commission may obtain a declaration of a general and persistent failure to fulfil obligations, whether Bulgaria may claim a temporary exemption from the limit values and whether the Commission may infer from persistent non-compliance with the limit values that the air quality plans are deficient.

7.

Under Article 2 of the Protocol concerning the conditions and arrangements for admission of the Republic of Bulgaria and Romania to the European Union, ( 9 ) from the date of accession — 1 January 2007 — the acts adopted by the institutions before accession, in particular, are to be binding on Bulgaria and Romania and to apply in those States under the conditions laid down in the Treaties and the Protocol. No exception was agreed for the rules on ambient air quality.

8.

Article 2(18) of Directive 2008/50 defines the particulate matter at issue as follows:

‘“PM10” shall mean particulate matter which passes through a size-selective inlet as defined in the reference method for the sampling and measurement of PM10, EN 12341, with a 50% efficiency cut-off at 10 μm aerodynamic diameter’.

9.

Article 13(1) of Directive 2008/50 requires compliance with the limit values for PM10:

‘Member States shall ensure that, throughout their zones and agglomerations, levels of sulphur dioxide, PM10, lead, and carbon monoxide in ambient air do not exceed the limit values laid down in Annex XI.’

10.

Annex XI of Directive 2008/50 includes an annual mean for PM10 of 40 μg/m3 and a daily limit value of 50 μg/m3, which may be exceeded not more than 35 days per year.

11.

Under Article 5(1) and Annex III, stage 1, of Council Directive 1999/30/EC of 22 April 1999 relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air, ( 10 ) the same obligation had already applied since 1 January 2005.

12.

Article 22 of Directive 2008/50 lays down a procedure under which Member States may, under certain conditions, apply for a temporary exemption inter alia from the obligation to comply with the limit values for PM10 until 11 June 2011:

‘1.   Where, in a given zone or agglomeration, conformity with the limit values for nitrogen dioxide or benzene cannot be achieved by the deadlines specified in Annex XI, a Member State may postpone those deadlines by a maximum of five years for that particular zone or agglomeration, on condition that an air quality plan is established in accordance with Article 23 for the zone or agglomeration to which the postponement would apply; such air quality plan shall be supplemented by the information listed in Section B of Annex XV related to the pollutants concerned and shall demonstrate how conformity will be achieved with the limit values before the new deadline.

2.   Where, in a given zone or agglomeration, conformity with the limit values for PM10 as specified in Annex XI cannot be achieved because of site-specific dispersion characteristics, adverse climatic conditions or transboundary contributions, a Member State shall be exempt from the obligation to apply those limit values until 11 June 2011 provided that the conditions laid down in paragraph 1 are fulfilled and that the Member State shows that all appropriate measures have been taken at national, regional and local level to meet the deadlines.

3.   …

4.   Member States shall notify the Commission where, in their view, paragraphs 1 or 2 are applicable, and shall communicate the air quality plan referred to in paragraph 1 including all relevant information necessary for the Commission to assess whether or not the relevant conditions are satisfied. In its assessment, the Commission shall take into account estimated effects on ambient air quality in the Member States, at present and in the future, of measures that have been taken by the Member States as well as estimated effects on ambient air quality of current Community measures and planned Community measures to be proposed by the Commission.

Where the Commission has raised no objections within nine months of receipt of that notification, the relevant conditions for the application of paragraphs 1 or 2 shall be deemed to be satisfied.

If objections are raised, the Commission may require Member States to adjust or provide new air quality plans.’

13.

Under Article 23(1) of Directive 2008/50, Member States must establish air quality plans where the limit values are exceeded:

‘Where, in given zones or agglomerations, the levels of pollutants in ambient air exceed any limit value or target value, plus any relevant margin of tolerance in each case, Member States shall ensure that air quality plans are established for those zones and agglomerations in order to achieve the related limit value or target value specified in Annexes XI and XIV.

In the event of exceedances of those limit values for which the attainment deadline is already expired, the air quality plans shall set out appropriate measures, so that the exceedance period can be kept as short as possible. ...

Those air quality plans shall incorporate at least the information listed in Section A of Annex XV ... Those plans shall be communicated to the Commission without delay, but no later than two years after the end of the year the first exceedance was observed.

…’

14.

A similar obligation had already been laid down in the first sentence of Article 7(3) of Council Directive 96/62/EC of 27 September 1996 on ambient air quality assessment and management: ( 11 )

‘Member States shall draw up action plans indicating the measures to be taken in the short term where there is a risk of the limit values and/or alert thresholds being exceeded, in order to reduce that risk and to limit the duration of such an occurrence.’

15.

Section A of Annex XV of Directive 2008/50 contains requirements for those plans. Point 6 requires the following information for analysis of the situation:

16.

Point 8 provides that the air quality plans must include details of those measures or projects adopted with a view to reducing pollution:

17.

Under Article 33 of Directive 2008/50, the directive had to be implemented by 11 June 2010.

18.

Article 31 of Directive 2008/50 governs the repeal of Directives 96/62 and 99/30:

‘Directives 96/62/EC, 1999/30/EC, 2000/69/EC and 2002/3/EC shall be repealed as from 11 June 2010, without prejudice to the obligations on the Member States relating to time-limits for transposition or application of those Directives.

…’

19.

There is no dispute between the parties that from 2007 to at least 2015 both the daily limit values and the annual limit values for PM10 were exceeded in all Bulgaria’s zones and agglomerations. Only in zone BG0003 Varna in 2009 was the annual limit value not reached.

20.

On account of this exceedance of limit values, Bulgaria made representations to the Commission with a view to a postponement of the deadline for compliance with the limit values (see under A), whilst the Commission brought the present infringement proceedings (see under B).

21.

On 14 April 2009 the Commission received a notification from Bulgaria, which stated that the limit values for PM10 could not be complied with in the country’s six agglomerations. Bulgaria was therefore postponing the deadline for compliance with the limit values pursuant to Article 22 of Directive 2008/50.

22.

However, on 11 December 2009 the Commission decided to raise objections against that notification.

23.

On 9 June 2011 Bulgaria sent the Commission another notification with a view to the postponement of the deadline. The Commission nevertheless rejected that notification because the deadline could be extended to 11 June 2011 at the latest and the second subparagraph of Article 22(4) of Directive 2008/50 allowed it a period of nine months to examine the notification.

24.

In the meantime, on 1 October 2010 the Commission had requested Bulgaria to submit observations on an infringement of Article 13 of Directive 2008/50. On 25 January 2013 the Commission supplemented that request with a complaint that Bulgaria had not drawn up any appropriate plans in accordance with Article 23. The Commission referred in this regard to the period from 2007 to 2011.

25.

Bulgaria does not dispute the non-compliance with the limit values, but asserts that exceedances are decreasing.

26.

The Commission maintained its complaints and on 11 July 2014 issued a reasoned opinion in which it now also relied on the figures for 2012 and set Bulgaria a final deadline of two months.

27.

In its replies Bulgaria continued to claim that the situation was gradually improving. The exceedances stemmed primarily from the use of certain fuels for domestic heating during the winter.

28.

As the Commission considered these replies to be inadequate, on 14 September 2015 it brought the present action and claims that the Court should:

29.

The Republic of Bulgaria contends that the Court should dismiss the action either as inadmissible or as unfounded and order the Commission to pay the costs.

30.

The parties submitted written observations and presented oral argument on 29 September 2016. At the hearing the Republic of Poland intervened in support of Bulgaria.

31.

The Commission alleges that Bulgaria has failed to fulfil two obligations under Directive 2008/50: first, the duty to comply with the limit values for PM10 (see under A) and, second, the duty, on account of the exceedance of the limit values, to adopt air pollution control plans to keep the exceedance period as short as possible (see under B).

32.

The first plea in law concerns the exceedance of the limit values for PM10 under Article 13 and Annex XI of Directive 2008/50. In those provisions two kinds of PM10 limit values are established: the 24-hour limit value of 50 μg/m3, which is not to be exceeded more than 35 times a year, and the annual limit value of 40 μg/m3, which may not be exceeded at all.

33.

It is common ground that since Bulgaria’s accession one of these limit values, the annual limit value, was complied with only in zone BG0003 Varna in a single year, 2009. Otherwise both limit values were continually exceeded. The most recent figures mentioned in the written procedure relate to 2015.

34.

Whilst the exceedance of the limit values is undisputed, the precise definition of the subject matter of the proceedings in this regard raises difficulties, which also form the basis for Bulgaria’s objections to the admissibility of the action (see under 1). It must also be clarified whether Bulgaria may claim a temporary exemption from the limit values (see under 2(a)) and whether the obligation to comply with the limit values is an obligation of result or covers only efforts to comply (see under 2(b)).

35.

It could be assumed at first glance that the Commission is seeking a declaration that the limit values were exceeded in the zones and agglomerations concerned during the years indicated. However, as Bulgaria’s objections show, such a head of claim would be manifestly inadmissible, at least in part.

36.

The subject matter of the action brought under Article 258 TFEU is delimited by the pre-litigation procedure provided for by that article. Accordingly, the action cannot be founded on any objections other than those stated in the pre-litigation procedure. The purpose of the pre-litigation procedure is to give the Member State concerned an opportunity, on the one hand, to comply with its obligations under EU law and, on the other, to avail itself of its right to defend itself against the objections formulated by the Commission. ( 12 )

37.

The Commission would infringe these principles if it requested declarations in respect of 2013 in the action, and even in respect of 2014 in the reply, even though the reasoned opinion refers to 2012 as the last year. In addition, the reasoned opinion extends one year further than the supplementary invitation to submit observations.

38.

I nevertheless consider these submissions to be admissible in principle.

39.

An administrative practice can be the subject matter of an action for failure to fulfil obligations when it is, to some degree, of a consistent and general nature ( 13 ) or a general and persistent failure to fulfil obligations. ( 14 )

40.

That is how I understand the Commission’s head of claim in so far as, in respect of the ‘systematic’ and ‘continuous’ exceedance of the limit values, it requests a declaration that Bulgaria ‘continues to’ infringe Article 13 and Annex XI of Directive 2008/50.

41.

In addition, that is the reason for the Commission’s reference to the exceedance of limit values in years which were not the subject matter of the pre-litigation procedure or the application. More recent information is able, at the stage of proceedings before the Court, to support the proposition that the failure alleged is general and consistent. ( 15 )

42.

This cannot be seen as an inadmissible extension of the subject matter of the action, as the complaint is still that Bulgaria persistently failed to comply with the limit values for PM10.

43.

However, in addition to the delimitation by the pre-litigation procedure, the principle applies that the question whether a Member State has failed to fulfil 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 and the Court cannot take account of any subsequent changes. ( 16 ) In the present case that period ended in September 2014.

44.

The Court may therefore only make declarations which relate to the time before the end of that period. The Commission’s submissions in respect of the time after the end of the period are of interest only in so far as they allow conclusions to be drawn regarding the previous situation.

45.

The Bulgarian complaint of unclear wording in the application, and thus of an infringement of Article 120(c) of the Rules of Procedure, essentially stems from a misunderstanding by Bulgaria of the possibility of a declaration of a general and persistent failure to fulfil obligations.

46.

It would have been desirable if the Commission had expressed the subject matter of its complaint more clearly, for example by reference to the Court’s relevant case-law, but it cannot be stated that the subject matter of the dispute is not evident.

47.

Lastly, it should be mentioned that the limit values from 2007 to 2010 were based on Article 5 and Annex III, stage 1, of Directive 1999/30, whereas the Commission relies solely on Directive 2008/50, which did not yet apply at the time.

48.

In proceedings under Article 258 TFEU, however, it is settled case-law that the Commission has standing to seek a declaration that a Member State has failed to fulfil obligations which were created in the initial version of an EU measure, subsequently amended or repealed, and which were maintained in force under the new provisions. ( 17 )

49.

This also applies in the present case, as Article 13 and Annex XI of Directive 2008/50 contain the same limit values for PM10 as Article 5 and Annex III, stage 1, of Directive 1999/30 for the period before the entry into force of Directive 2008/50. This is confirmed by Article 31(3) of Directive 2008/50, under which references to the repealed directives, and thus to Directive 1999/30, are to be construed as being made to the new directive.

50.

Consequently, there is also no need for the Commission to make express mention of the earlier rules in its head of claim. ( 18 ) It is sufficient that in the pleas in law in support of its action it made clear the continued validity of the limit values and their respective legal basis.

51.

The plea in law regarding non-compliance with the limit values and the Commission’s submissions in respect of the infringements up to the end of the period laid down in the reasoned opinion in September 2014 are thus admissible.

52.

The Commission’s complaint is in any case also well founded for the years 2007 to 2013 referred to in the claim made in the application.

53.

In Bulgaria the limit values for PM10 were exceeded in that period in all agglomerations and zones with one exception in one year, that is to say, since those limit values became applicable in Bulgaria under the Protocol on accession. The failure to fulfil obligations is thus both general and persistent.

54.

As regards 2014, the year also mentioned in the claim made in the reply, on the other hand, the period laid down in the reasoned opinion expired in September of that year. However, the limit values relate to the whole year, namely the number of exceedances of the daily limit value during the year and the annual mean. The Commission does not explain whether non-compliance with the limit values can be established solely on the basis of the measurement data collected up to that time. Even if it were possible to translate the limit values to the time of the year which passed up to the end of the period, the Commission would have to make submissions in this regard. However, none have been made. Consequently, an infringement cannot be established in respect of 2014 and the action must be dismissed in that respect.

55.

However, the Commission’s complaint would be rendered largely unfounded if Bulgaria had successfully obtained, pursuant to Article 22 of Directive 2008/50, a temporary exemption from the obligation to comply with the limit values for PM10 until 11 June 2011, as all the exceedances of limit values which existed at the time of the supplementary invitation to submit observations would then be immaterial. ( 19 )

56.

It is undisputed that Bulgaria’s application from 2009 could not give rise to an exemption, as the Commission raised objections to the application in good time, with the result that Bulgaria would have had to submit a modified application pursuant to the third subparagraph of Article 22(4) of Directive 2008/50.

57.

Bulgaria nevertheless takes the view that its application of 9 June 2011 was such a modified application to which the Commission did not effectively raise objections.

58.

Although the Commission did not take a formal decision to object to the application, in its letter of 11 July 2011 it clearly stated that in its view the application had been made out of time.

59.

That letter constitutes a refusal which was not challenged by Bulgaria. Bulgaria also quite rightly does not claim the non-existence of that decision, as a finding that an act is non-existent must, for reasons of legal certainty, be reserved for quite extreme situations. ( 20 ) Moreover, the present case illustrates the risks to legal certainty attaching to a finding that an act is non-existent. Consequently, Bulgaria must accept the refusal of its notification in this case. On that ground, an exemption under Article 22 of Directive 2008/50 must be ruled out.

60.

For the same reason, there is no reason to decide in the present case whether the Commission failed to fulfil its duty of sincere cooperation under Article 4(3) TEU in so far as it did not examine the merits of the application of 9 June 2011. This argument by Bulgaria could possibly have called into question the lawfulness of the letter of 11 July 2011. However, as Bulgaria did not challenge that communication, that Member State could not consider that it was exempt from its obligation to comply with the limit values. ( 21 )

61.

Should the Court not concur with this view, it would have to be examined whether the Commission was right to refuse the application as out of time.

62.

The Commission asserts that the refusal is justified because it may not retroactively legalise a situation which is contrary to the directive.

63.

However, Article 22 of Directive 2008/50 does not preclude a retroactive exemption. On the contrary, that provision is designed to have retroactive effect for PM10 in particular, as the relevant limit values have applied since 2005 but the possibility of an exemption was not granted until 2008. In addition, a legitimate interest in a retroactive exemption cannot be ruled out, for example, in order to eliminate any basis for claims for damages.

64.

Nevertheless, it is correct that an exemption is possible only if the relevant conditions are met. Article 22(1) of Directive 2008/50 requires that the Member State submits an air quality plan, which demonstrates how conformity with the limit values will be achieved before the new deadline, for PM10 by 11 June 2011 at the latest. ( 22 )

65.

The application of 9 June 2011 should therefore have demonstrated that the limit values would be complied with within two days at the latest. This conclusion can be ruled out on the basis of the levels actually notified. The limit values were exceeded almost universally in the Bulgarian zones and agglomerations before and after the application. The only time the figures were below the annual limit value in the Varna zone a few years previously, there were too many exceedances of the daily limit values.

66.

It can therefore be ruled out that Bulgaria’s application satisfied the conditions for an exemption. Accordingly, the Commission would also have rightly objected to Bulgaria’s application if it had conducted a comprehensive examination.

67.

However, even if Bulgaria had submitted an exemption notification with the notice of compliance with the limit values from 11 June 2011, it would be an abuse of the law for that Member State now to rely on this, in view of its persistent exceedance.

68.

It can therefore be concluded that Bulgaria was not exempted from the obligation to comply with the limit values for PM10 until 11 June 2011.

69.

Furthermore, Bulgaria attempts to refute the Commission’s allegation with its efforts to improve ambient air quality, its purported improvement and the country’s economic situation.

70.

These arguments cannot call into question the finding of a general and persistent failure to comply with the limit values. The Court has repeatedly held that the mere exceedance of the limit values infringes Article 13 and Annex XI of Directive 2008/50, ( 23 ) unless force majeure is proven. ( 24 ) It thus constitutes an obligation of result (obligation de résultat) and not a duty merely to make efforts to comply with the limit values.

71.

Acceptance of the existence of an obligation of result is also not precluded by the fact that under the second subparagraph of Article 23(1) of Directive 2008/50 the Member States are not required to take measures to prevent or immediately bring to an end any exceedance of the limit values, but only to keep it as short as possible.

72.

If the second subparagraph of Article 23(1) of Directive 2008/50 were to be construed to the effect that this obligation to establish air quality plans is the sole legal consequence of an infringement of ambient air quality standards, there would be doubts as to the existence of an obligation of result, as this would be less onerous than the general obligation under EU law to bring to an end infringements of EU law as quickly as possible and under certain conditions to provide compensation for damage. ( 25 ) The importance of the duration of the infringement would also be relativised, as the obligation to establish a plan implies that an infringement cannot, as a rule, be brought to an end immediately, but only over a certain period of time. This interpretation seems reasonable on account of the difficulties in implementing ambient air quality standards which also characterised the recasting of the Ambient Air Quality Directive.

73.

As the Court has rightly observed, however, only Article 22(1) of Directive 2008/50 expressly provides for the possibility of a Member State postponing the deadline laid down in Annex XI to the directive for achieving conformity with the limit values established in that annex. ( 26 ) It would be contradictory to infer from the obligation to establish air quality plans under the second subparagraph of Article 23(1), in addition to this postponement of deadlines which is expressly provided for and subject to stringent conditions and limits, ( 27 ) a further exception, which is merely implicit but not limited in time. ( 28 ) This would constitute an impairment of the effectiveness of ambient air quality standards ( 29 ) which cannot be accepted on account of their great importance for human health.

74.

Furthermore, Directive 2008/50 also contains air quality targets which are clearly not designed as an obligation of result. Under Articles 15(1) and 16(1), the Member States must take only necessary measures not entailing disproportionate costs to achieve compliance with the exposure targets for PM2,5, which are even smaller particles. If the legislature had not intended to fix the limit values for PM10 as an obligation of result, it would have opted for a similar wording.

75.

Directive 2008/50 thus establishes two interconnected, but different obligations in respect of PM10: on the one hand, the preventive and unconditional obligation of result to comply with the limit values and, on the other, the protection obligations in the event of exceedance.

76.

It must nevertheless be assumed that the legal consequences of non-compliance with the limit values are affected by the air quality plans. In particular, there is much to suggest that an air quality plan which satisfies the requirements of Directive 2008/50 and its faithful implementation can reduce the gravity of the infringement. Such a plan could possibly even justify the non-imposition of a penalty payment in proceedings under Article 260 TFEU or preclude liability for damages ( 30 ) in the event of non-compliance with limit values. In the present case, it is not yet necessary to decide these questions, although against this background additional weight must be given to the Commission’s second plea in law.

77.

The interpretation of the obligation to comply with the limit values as an obligation of result is also not called into question by the somewhat unclear wording of the judgment in ClientEarth. In that judgment, the Court noted that while, as regards sulphur dioxide, PM10, lead and carbon monoxide, the first subparagraph of Article 13(1) of Directive 2008/50 provides that Member States are to ‘ensure’ that the limit values are not exceeded, the second subparagraph of Article 13(1) states that, as regards nitrogen dioxide and benzene, the limit values ‘may not be exceeded’ after the specified deadline, which amounts to an obligation to achieve a certain result. ( 31 )

78.

As I understand it, the Court did not intend to draw a contrast between the obligations in respect of sulphur dioxide, PM10, lead and carbon monoxide, on the one hand, and nitrogen dioxide and benzene, on the other. Instead, it gives a somewhat misleading confirmation of previous case-law. The same obligation is expressed in two different wordings. ( 32 )

79.

Furthermore, the finding of general and persistent non-compliance with the limit values is also not called into question by the fact that one of the two limit values was not exceeded in 2009 in one of six zones, the Varna zone. This is clearly an atypical case which can only be caused by special circumstances. Subsequently, that limit value was also exceeded again in that zone. In addition, the daily limit value was exceeded too often in that zone in 2009.

80.

Bulgaria therefore failed to fulfil its obligations under Article 13(1) in conjunction with Annex XI of Directive 2008/50 on ambient air quality and cleaner air for Europe in respect of PM10 from 2007 to 2013 generally and persistently in all the country’s agglomerations and zones.

81.

The Commission’s second plea in law concerns the obligation to establish air quality plans under Article 23 of Directive 2008/50.

82.

Where, in given zones or agglomerations, the levels of pollutants in ambient air exceed any limit value, under the first subparagraph of Article 23(1) of Directive 2008/50, Member States must ensure that air quality plans are established for those zones and agglomerations in order to achieve the related limit value. Under the first sentence of the second subparagraph of Article 23(1), in the event of exceedances of those limit values for which the attainment deadline is already expired, the air quality plans must set out appropriate measures, so that the exceedance period can be kept as short as possible. The first sentence of the third subparagraph of Article 23(1) provides that those air quality plans must incorporate at least the information listed in Section A of Annex XV.

83.

Since the exceedance of the limit values, Bulgaria is therefore required to establish air quality plans pursuant to the first subparagraph of Article 23(1) of Directive 2008/50. In the absence of an exemption from the obligation to comply, those plans had to set out appropriate measures, in accordance with the first sentence of the second subparagraph of Article 23(1), so that the exceedance period can be kept as short as possible.

84.

The parties agree that Bulgaria did establish air quality plans.

85.

However, the Commission infers from the continued exceedance of the limit values that Bulgaria has failed to keep the exceedance period as short as possible. In its view, Bulgaria has not taken all the necessary and scientifically possible measures to bring to an end the exceedance of the limit values. The Commission also objects that envisaged measures have not yet been taken and that the Bulgarian plans do not set out certain information.

86.

It is again necessary to specify the subject matter of the proceedings in connection with this plea in law (see under 1), before examining the evidence submitted by the Commission (see under 2) and the quality of the Bulgarian air quality plans (see under 3).

87.

The same principles apply to the admissibility of this plea in law as to the admissibility of the first plea in law. Whilst the Commission does not confine its submissions to information that was the subject matter of the invitation to submit observations and the reasoned opinion, subsequent circumstances are merely additional evidence of a persistent and general practice in establishing and implementing air quality plans.

88.

However, the admissible subject matter of this plea in law is also limited in time by the deadline of 11 September 2014 laid down in the reasoned opinion.

89.

The question also arises whether this head of claim also includes infringement of the obligations applying before Directive 2008/50. They stem from Directive 96/62 in conjunction with Directive 99/30.

90.

The situation is different in this regard from the limit values. There is no need to determine whether the earlier rules contained similar requirements as are now laid down in Article 23(1) and Section A of Annex XV of Directive 2008/50. The Commission itself takes the view that Article 23(1) of Directive 2008/50 is more stringent than Directive 96/62, stating that Directive 96/62 requires only compliance with the limit values within a reasonable deadline while under Directive 2008/50 the deadline must remain as short as possible. A tightening of requirements, however, rules out continuity.

91.

The Commission may not therefore rely on the continued validity of the planning obligations under Directive 96/62. Rather, an infringement of Article 23(1) of Directive 2008/50 may be established only upon expiry of the obligation to transpose the latter directive, that is to say, no earlier than 11 June 2010.

92.

The Commission’s submissions are thus admissible only to this extent.

93.

The inference drawn by the Commission from the duration of the exceedance of a failure to keep it as short as possible implies that the exceedance must be brought to an end within a certain period. However, no such certain period is either expressly laid down in Directive 2008/50 or can be inferred from that directive.

94.

The Court has thus far held with regard to air quality plans only that under the second subparagraph of Article 23(1) of Directive 2008/50, while Member States have a degree of discretion in deciding which measures to adopt, those measures must, in any event, ensure that the period during which the limit values are exceeded is as short as possible. ( 33 )

95.

This finding should be seen in the light of the earlier judgment in Janecek regarding the action plans on measures to be taken in the short term where there is a risk of the limit values being exceeded under Article 7(3) of Directive 96/62. The Court found that it is apparent from the broad logic of the directive — which seeks an integrated reduction of pollution — that it is for the Member States to take measures capable of reducing to a minimum the risk of the limit values and/or alert thresholds being exceeded and the duration of such an occurrence, taking into account all the material circumstances and opposing interests. ( 34 ) In this connection, the Court has also recognised that in exercising discretion the Member States should, in addition to the aim of minimising the exceedance, also take into account the balance which must be maintained between that objective and the various opposing public and private interests. ( 35 )

96.

The air quality plans under Article 23(1) of Directive 2008/50 can also be adopted only on the basis of such a balance of interests. The high importance of ambient air quality for the protection of life and health leaves only very little room for consideration of other interests. It therefore also requires a strict review of the assessment made. ( 36 ) However, there are undeniably overriding interests which may preclude certain appropriate measures.

97.

Thus, according to Bulgaria, domestic heating during the winter using solid fuels, in particular wood and coal, is the primary cause of the exceedance of limit values. A ban on such heating would therefore appear to be an appropriate measure for bringing about compliance with the limit values. However, that measure is not possible where no other forms of heating are available, since without heating even greater effects on human health could be expected.

98.

Bulgaria therefore rightly states that it can be determined what period of time is ‘as short as possible’ only on the basis of an assessment of the individual case. The duration of the exceedance alone is not sufficient, as it does not in itself allow any inference to be drawn as to whether the balancing with other interests was deficient.

99.

The Commission’s central argument cannot therefore be directly upheld. The question whether the limit values were exceeded for a certain number of years, be it seven, eight or nine years, cannot in itself determine whether that period of time was ‘as short as possible’.

100.

This does not mean, however, that this argument by the Commission is irrelevant.

101.

Rather, the Court should draw guidance from its case-law on waste legislation. In that field the Member States are subject to the general obligation now laid down in Article 13 of the Waste Directive ( 37 ) to ensure that waste management is carried out without endangering human health and without harming the environment. If a situation which is not compatible with that objective persists, for example an illegal landfill site, this is an indication of a failure to fulfil those duties, in particular if it leads to a significant deterioration in the environment over a protracted period without any action being taken by the competent authorities. ( 38 )

102.

The same holds in the present case. In Bulgaria the limit values for PM10 have not been complied with for a protracted period, which has serious effects on the health of the Bulgarian population. This is a strong indication that Bulgaria has not complied with its obligation under the second subparagraph of Article 23(1) of Directive 2008/50.

103.

It is true that Bulgaria takes the view that the exceedance of the limit values cannot at the same time form the basis for an infringement of Article 13(1) and of the second subparagraph of Article 23(1) of Directive 2008/50, as the latter obligation is only triggered upon the infringement of the former.

104.

However, this argument fails to recognise that non-compliance with the limit values does not form the basis for the infringement of the second subparagraph of Article 23(1) of Directive 2008/50, but is merely an indication that the air quality plans do not satisfy the requirements. Whilst this cannot be inferred from the first exceedance, the longer the exceedances persist, the more they show how effective — or ineffective — the measures already taken to improve air quality were.

105.

In assessing this indication, the undisputed infringements after the end of the period laid down in the reasoned opinion, that is, in 2014 and 2015, are also relevant. They confirm that the air quality plans existing before the end of the period were not even sufficient to comply with the limit values at a later time.

106.

The importance of the duration of the exceedance is also not diminished by the fact that only the obligation applying since 11 June 2010 is the subject matter of the proceedings. Bulgaria was required to take action to prevent air pollution not only from that date, but from its accession in January 2007, when Article 7(3) of Directive 96/62 became applicable. The effectiveness of the measures adopted between 11 June 2010 and 11 September 2014 must therefore be assessed against the background of more than three years of earlier efforts to improve ambient air quality. Because these attempts were not sufficient, there was all the more reason to take effective measures after 11 June 2010.

107.

Bulgaria must therefore rebut this evidence based on persistent exceedance of the limit values. To this end, that Member State would in particular have to demonstrate that its air quality plans satisfy the requirements of Article 23(1) and Section A of Annex XV of Directive 2008/50.

108.

According to the submissions made by Bulgaria and the Commission, the previous plans are nevertheless deficient.

109.

It is common ground that those plans included different target dates for compliance with the limit values but those targets were not achieved. The Commission also submits, without being contradicted on this point, that consideration was not given to the full range of possible measures, such as stricter quality standards for solid fuels for domestic heating or road traffic restrictions.

110.

In addition, the Bulgarian plans suffer from structural deficiencies.

111.

As the Commission further asserts, Bulgaria did not provide any information on the precise territorial scope of the plans, the timetable for their implementation, the improvements in ambient air quality to be expected as a result of the planned measures or the date of compliance with the limit values.

112.

The Commission refers in this regard to the information required under Section A of Annex XV of Directive 2008/50. In particular, under point 6(b) of that section, details are to be provided of possible measures for the improvement of air quality. In addition, point 8 requires a listing and description of all the measures set out in the project (letter (a)), a timetable for implementation (letter (b)) and an estimate of the improvement of air quality planned and of the expected time required to attain these objectives (letter (c)).

113.

This information is of central importance as it is the only way to determine whether those air quality plans actually ensure that the period of exceedance of the limit values remains as short as possible. On the basis of that information it can be examined whether the Member State has identified all the measures to improve ambient air quality and which measures it has chosen. At the same time, it can also be estimated to what extent and over what time air quality will improve. It ultimately shows whether and by when it will be possible under these plans to comply with the limit values.

114.

Although Bulgaria describes a number of measures and plans, it does not dispute that the abovementioned information is largely absent.

115.

Bulgaria nevertheless points out a contradiction in the Commission’s arguments. The Commission asserts, on the one hand, that Bulgaria did not indicate when compliance with the limit values could be expected while, on the other, it complains that some plans included such dates, which had passed without the limit values being met.

116.

However, this contradiction has no great importance, as a notice of compliance with limit values which is not realised is merely further evidence of the deficiencies in an air quality plan.

117.

Consequently, the air quality plans established by Bulgaria to reduce air pollution by PM10 do not satisfy the requirements under the second subparagraph of Article 23(1) of Directive 2008/50 and in particular do not contain all the necessary information under Section A of Annex XV of Directive 2008/50.

118.

Bulgaria was thus also unable to show that, despite the persistent exceedance of the limit values, it took the necessary measures so that that exceedance remains as short as possible.

119.

In summary, with regard to the second plea in law, it must be stated that Bulgaria failed, from 11 June 2010 to 11 September 2014 generally and persistently in all the country’s agglomerations and zones, to comply with its obligation under Article 23(1) of Directive 2008/50 to establish and implement air quality plans pursuant to Section A of Annex XV to reduce air pollution by PM10, so that the exceedance period for the limit values under Article 13(1) and Annex XI could be kept as short as possible.

120.

Under Article 138(1) 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 essentially been successful, Bulgaria must be ordered to pay the costs.

121.

However, under Article 140(1) of the Rules of Procedure, the Member States and institutions which intervene in the proceedings are to bear their own costs. Consequently, Poland must bear its own costs.

122.

I therefore propose that the Court should rule as follows: