Europe's air is set to become cleaner over the course of the next few years with a revamp of the old 1988 directive on emissions from large combustion plants and the arrival of a new directive setting national emission ceilings for certain key pollutants. Tina Garrity reports

NATIONAL EMISSION CEILINGS DIRECTIVE
When the EU's sustainable development programme was reviewed in 1998, the Council and the Parliament specified that particular attention should be given to a strategy designed to ensure that critical loads, in relation to exposure to acidifying, eutrophying and photochemical air pollutants, were not exceeded. Then, in December 1999, the Gothenburg Protocol to the 1979 UNECE Convention on long-range transboundary air pollution was agreed and subsequently signed by all member states.
The protocol contains commitments to reduce emissions of sulphur dioxide (SO2) and oxides of nitrogen (NOX). At present, significant areas of the EU are exposed to depositions of acidifying and eutrophying pollutant at levels which have adverse effects on the environment. In respect of photochemical air pollutants, the current WHO guideline values are substantially exceeded in all member states. According to the Commission, it is not yet technically feasible to eliminate the adverse effects of acidification and to reduce exposure to ground-level ozone to the WHO guideline value. Nevertheless, some action must be taken now, it believes. It has managed to secure agreement on a set of interim environmental objectives for acidification and for ground-level ozone pollution, upon which the necessary long-term measures will be based. These are as follows: - Acidification: The areas where critical loads are exceeded shall be reduced by at least 50 per cent (in each grid cell) compared with the 1990 situation. - Health-related ground-level ozone exposure: The ground-level ozone load above the critical level for human health (AOT60=0) shall be reduced by two-thirds in all grid cells compared with the 1990 situation. In addition, the ground-level ozone load shall not exceed an absolute limit of 2.9 ppm/h in any grid cell. - Vegetation-related ground-level ozone exposure: The ground-level ozone load above the critical level for crops and semi-natural vegetation (AOT40=3 ppm/h) shall be reduced by one-third in all grid cells compared with the 1990 situation. In addition, the ground-level ozone load shall not exceed an absolute limit of 10 ppm/h, expressed as an exceedance of the critical level of 3 ppm/h in any grid cell.

In order to help achieve these objectives, a new directive has been agreed setting out for each member state national emission ceilings for sulphur dioxide, nitrogen dioxides, VOCs and ammonia. The agreed ceilings for the UK are in table 1 below. In its September 2001 regulatory and environmental impact assessment statement on the proposed directive, DEFRA stated that the UK welcomed the ceilings approach which aims to maximise cost-effectiveness across the EU. But it considers that the costs of reaching the ceilings proposed by the Commission may not be justified by the benefits.1
The directive requires each member state to draft and make public, in a clear, comprehensible and easily accessible manner, by 1 October this year, a national programme for the progressive reduction of emissions. This programme must be updated and revised, where necessary, by 1 October 2006. The directive also requires each member state to compile and annually update a national emissions inventory and to establish projections of emissions using certain methodologies specified in an annex to the directive. The UK already has a national atmospheric emission inventory, accessible via the AEA Technology website.2 In 2004 and again in 2008, the Commission will have to report to the Parliament and the Council on progress in implementing the national emission ceilings, as well as on the extent to which the interim environmental objectives are likely to be met and to what extent the long-term objectives of the directive could be met by 2020. Details of what must be included in the Commission's report are given in the directive.

At present, emissions from international maritime traffic and from aircraft (beyond take-off and landing) are not covered by the directive. Under the directive, the Commission must report by the end of this year, in the case of maritime traffic, and by the end of 2004, in the case of aircraft, on the extent to which such emissions contribute to acidification, eutrophication and the formation of ground level ozone within the EU. These reports must specify a programme of actions which could be taken at international and at EU level to reduce emissions. Directive 2001/81/EC of the European Parliament and of the Council of 23 October 2001 on national emission ceilings for certain atmospheric pollutants. OJ L 309. 27.11.01 pp 22-30

REFERENCES
1 www.defra.gov.uk /environment/airquality/reia/200181ec/index.htm
2 www.aeat.co.uk/netcen/airqual/

LARGE COMBUSTION PLANTS DIRECTIVE It is now some 14 years since the directive on the limitation of emissions from large combustion plants was agreed.1 Apart from the need to generally update and reclarify the provisions of the old directive, the Commission feels that with the various developments in EU environmental policy over the years and the setting of new pollution reduction targets such as those laid down in the Gothenburg Protocol (see above) the time has come for the old directive to be repealed and replaced by a new one. This has now been achieved and the new rules are to be implemented by 27 November this year.

Like the old directive, the new one covers combustion plants, the rated thermal input of which is equal to or greater than 50mw, irrespective of the type of fuel used. The emission targets contained in the new directive are laid down in seven annexes. Annexes I and II set out ceilings and reduction targets for SO2 and NOx from existing plants for each member state. Annexes III, IV and V contain SO2 emission limit values for solid, liquid and gaseous fuels. Annex VI sets out emission limit values for NOx and annex VII sets emission limit values for dust. Methods of measurement of emissions are set out in Annex VIII. In licensing new or significantly extended existing plants, member states must ensure that the technical and economic feasibility of providing for the combined generation of heat and power is examined. Where feasible, installations must be developed accordingly.

By 31 December 2004, the Commission must submit a report to the Council and to the Parliament assessing the need for further measures, the amounts of heavy metals emitted by large combustion plants, the cost effectiveness and costs and advantages of further reduction measures in this sector compared to other sectors and the technical and economic feasibility of such measures. Directive 2001/80/EC of the European Parliament and of the Council of 23 October 2001 on the limitation of emissions of certain pollutants into the air from large combustion plants. OJ L 309. 27.11.01 pp 1-21

REFERENCE
1 88/609/EEC. OJ L 336. 07.12.88. pp 1-13.