Transport CommitteeWritten evidence from the Environment Agency (AS 26)


The Environment Agency agrees that noise is the highest profile local environmental issue arising from aviation. However, airport operations may have other local environmental impacts which need to be taken into account in developing a strategy for aviation capacity in the UK. These include air quality, water quality, waste management, water resources, flood risk and impacts on conservation.

The Environment Agency welcomes the government’s suggestion to better align Airport Surface Access Strategies with Airport Master Plans and further suggests that their role might be widened and strengthened to provide a framework within which local impacts could be dealt with in a more integrated manner.

The Environment Agency welcomes the Government’s commitment to developing an Airports National Policy Statement for nationally significant airport infrastructure and suggests that the statement needs to identify clearly the need for consideration of local environmental impacts and measures to adapt to climate change.

The Environment Agency believes that there can be significant benefits in early engagement over development proposals. This will aid faster decision making whilst reducing costs and protecting the environment.

1 Introduction

1.1 The Environment Agency has a role to protect and improve the environment in England and Wales and is the Government’s principal advisor on the environment. It was established to bring together responsibilities for protecting and improving the environment, to enable an to be taken integrated approach and to contribute to sustainable development.

1.2 As part of its inquiry into aviation strategy the Transport Select Committee has indicated that it is seeking evidence on potential constraints on increasing airport capacity. The Environment Agency is pleased to have the opportunity to provide evidence on the potential local environmental impacts of aviation and how the UK’s future airport capacity could be met whilst still protecting the environment.

2 Local Environmental Impact of Aviation

2.1 In its Draft Aviation Policy Framework, published in July 2012, the Government identifies noise as the highest profile local environmental issue arising from aviation. However, airport operations also give rise to, or may be affected by, a number of other environmental issues which, depending on location and circumstances, can be important and will need to be taken into account in developing a strategy for aviation capacity in the UK. Local issues which may need to be given particular consideration are air quality, water quality, water resources, flood risk and impacts on conservation. The nature and likely scale of these impacts, particularly for the south east of England, have been detailed in Annex 1.

3 Airport Master Plans and Airports National Policy Statement

3.1 Large airports may give rise to releases of some pollutants and impacts which are of an equivalent level to major industrial operations, for example, coal fired power stations. However, the assessment and management of local impacts arising from airport operations is often fragmented. For example, noise may be subject to government controls, planning constraints or action plans prepared under the Environmental Noise Directive. Vehicle emissions and nuisance from local ground transport may be considered as part of surface access strategies. The Environment Agency may regulate: point source emissions to air from large industrial boilers; waste; water quality discharges; and water abstraction. At some airports, local authorities may also be involved in developing local transport plans or dealing with releases to air from smaller activities taking place on site.

3.2 The Environment Agency is consulted for advice on the environmental impacts of proposed developments. It advises developers and planning authorities at the pre-planning application stage to allow early consideration of all the fundamental issues relating to whether a particular development will be acceptable in principle. The Environment Agency encourages developers to make contact as early as possible in the process and believes that this will help to reduce costs and burdens on developers, operators, and planning decision-makers. Early engagement will identify potential problems quickly and increase certainty over planning and permitting requirements that are needed to both develop the UK’s aviation capacity and protect the environment.

Airport Master Plans

3.3 The primary objective of voluntary Master Plans is to enable future development of the airport to be given due consideration in local planning processes and to encourage the aviation industry and local stakeholders to strengthen and streamline the way in which they work together. The Environment Agency welcomes the government’s suggestion in its draft Aviation Framework to align better Airport Surface Access Strategies with Airport Master Plans and further suggests that their role might be widened and strengthened to provide a framework within which local impacts could be dealt with more effectively in an integrated manner.

3.4 In its Draft Aviation Policy Framework the Government suggests that airport Master Plans will address, amongst others, the “core” areas of impact on people and the natural environment and identify proposals to minimise and mitigate those impacts. The Environment Agency welcomes consideration of these areas and suggests that Government provides further guidance on how they might be addressed, particularly in relation to the issues identified in Annex 1.

3.5 This approach would enable local impacts to dealt with in an integrated manner and provide a mechanism for better local engagement and consultation with the Environment Agency.

Airports National Policy Statement

3.6 The Environment Agency supports the approach of using an Airports National Policy Statement (NPS) to set out the national need for airport capacity and suggests that the local environmental issues (Annex 1) are also taken into account in developing any Airports NPS. It welcomes, too, the policy aim of looking for the least environmentally damaging solution to maintaining sufficient airport capacity.

3.7 The Environment Agency also believes that both the guidance for Airport Master Plans and the Airports NPS should make clear that all airports should formally assess their risks from a changing climate, and develop and implement plans to manage those risks.

4 Conclusions

4.1 The Environment Agency believes the government is right to identify noise as a key issue which needs to be considered in developing a UK aviation strategy.

4.2 In developing a UK aviation strategy, in addition to noise, consideration needs to be given to the local environmental impacts of any new airport capacity including air quality, water quality, water resources, flood risk and biodiversity.

4.3 The Environment Agency believes there would be significant benefits from early engagement with airport operators and developers on local environmental impacts. To realise these benefits it suggests that these local impacts are taken into account in any Airports National Policy Statement and in developing and strengthening the role Airport Master Plans.

17 October 2012

Annex 1


Air Quality

There is evidence that airports (and associated surface transport movements) can have a significant impact on local air quality and this should be taken into account in developing a strategy for airport capacity.

The main pollutants of interest arising from aviation are oxides of nitrogen and particulate matter. They may arise from aircraft in flight, during take-off and landing, from service vehicles on the ground and vehicles accessing the airport. Oxides of nitrogen and particulates can have direct effects on human health and are also involved in the formation of ozone and secondary particulate matter which affect human health. Oxides of nitrogen also contribute to acidification and eutrophication of sensitive ecosystems.

Nationally, emissions of oxides of nitrogen from airports and aviation are equivalent to approximately 15% of total emissions in the UK and are equivalent to around 50% of the total emissions from major industrial sources regulated by the Environment Agency. Airports and aviation are therefore a major source of oxides of nitrogen pollution in the UK.

Although aircraft engines do have standards for oxides of nitrogen emissions and these have tightened, to some degree, over the years, oxides of nitrogen emissions from airports are not directly controlled. To put this into context, emissions from a major airport, for example, Heathrow airport, are broadly comparable with those of a major industrial installation, such as a power station.

The contribution that airports’ emissions of oxides of nitrogen make to ground level pollutant concentrations will depend on the type and number of flight movements and volume of road traffic movements within and accessing the airport.

Annual average concentrations of nitrogen dioxide in the vicinity of Heathrow airport are in the region of 40–50 µg/m3 (depending on the monitoring site) and are expected to continue to exceed the EU air quality limit for the foreseeable future1. Air dispersion modelling studies suggest that approximately 30 to 45% of local oxides of nitrogen concentrations at some monitoring locations could be attributed to airport operations, 30% to traffic and the remainder to regional background sources.

Analysis of air quality data upwind and downwind of Gatwick and Heathrow during the April 2010 volcanic ash cloud event, when there was little activity at the airports, suggested that the airport contribution of oxides of nitrogen reduced to nearly zero at Gatwick and to 15% of normal levels at Heathrow.

Both oxides of nitrogen and particulate matter (PM10) may lead to long term effects on human health at a regional or national scale. A study carried out with respect to Heathrow airport indicated that the monetised cost of air emissions for the period 2015–2080 for the baseline airport operation (that is without expansion) would be approximately £750 million of which nearly 70% could be attributed to particulate matter (PM10) Error! Bookmark not defined.

Depending on location, increasing airport capacity may also lead to impacts on the natural environment. Semi-natural ecosystems may be sensitive to levels of oxides of nitrogen, either directly or indirectly through nitrogen deposition. The effect of increases of oxides of nitrogen or nitrogen deposition will depend on the magnitude of the release, the sensitivity of the local environment and the contribution from background concentrations.

Air dispersion modelling2 for a number of airports in England suggested that they may contribute an additional 1.5—20 µg/m3 of nitrogen dioxide equivalent3 to approximately 0.2—2.9 kgN/ha/yr in increased nitrogen deposition. In sensitive habitats this could lead to a reduction in species richness of up to 50% depending on background rates of deposition. We believe that any new policy framework should consider how the aviation sector can manage its impacts on ecosystems, particularly for European designated sites and Sites of Special Scientific Interest.

Water Quality

The Water Framework Directive (WFD) requires the Environment Agency to manage the water environment to consistent standards including both the chemical and ecological quality of surface waters and the chemical quality of ground waters. Good quality water is essential for drinking water, industry and wildlife and the Directive requires the UK to aim to achieve good chemical and ecological status for all water bodies by 2015, or, if that is not possible and subject to Directive requirements, by 2021 or 2027.

As with all developments, airports and their associated infrastructure pose potential threats to water quality. Of particular relevance to airports is their potential to add to the existing pressures of urban development on the water environment, as well as more specific concerns such as fuel spills and the use of pesticides and de-icing agents used to keep runways clear.

All groundwater bodies in the Thames basin have been designated as Drinking Water Protected Areas. Groundwater is under pressure from pollutants such as nutrients, solvents, pesticides and hydrocarbons. For example, a spill of aviation fuel at Heathrow which contaminated groundwater led to an estimated cleanup cost of over £1 million for the company concerned.

Water Resources

The Environment Agency has a duty to manage water resources in England and (currently) Wales. It does not manage water availability in isolation; it needs to consider managing flood risk and improving water quality to protect supplies, fisheries and natural habitats. Water availability also has to be looked at in terms of the potential impacts of climate change and population growth. These impacts will vary from place to place, however, those areas already experiencing water stress, particularly the Thames basin and the south east, will face a potential increase in population by the 2050s of more than 40%. The combined impacts of climate change and population indicate there could be less water available for people, businesses, agriculture and the environment.

Using a variety of scenarios (looking at demand, governance and societal behaviour), the Environment Agency has estimated potential water availability in the 2050s. For example, the Thames river basin district shows that although demand currently exceeds supply by approximately 35%, this could increase to between 50—127% depending on the scenario considered.

In the light of the existing stresses and future projections it is clear that any airport development will need to be carefully planned so as not to exacerbate the pressures on water availability and ensure that there will be sufficient water for people and the environment in the future.

Flood Risk

The Environment Agency has responsibility for managing flood risk in England and Wales. Over 5.5 million, or one in six, properties are at risk of floods across England and Wales. There are also risks to national infrastructure, with over 55% of water and sewage pumping stations, 20% of railways, 10% of major roads, 14% of electricity and 28% of gas infrastructure in England which are located in areas at risk of flooding. Population growth and the latest UKCP09 climate change projections indicate rising sea levels and increasingly severe and frequent rainstorms mean that unless appropriate measures are taken the risk of floods will increase.

Airfields, by design, cover large areas with hard surfaces thus reducing the capacity for infiltration of rainwater and potentially increase the likelihood of surface water flooding.


The Environment Agency is responsible for helping to conserve and enhance the diversity of native wildlife and habitats in England and Wales, particularly in the water environment. It works closely with Natural England to ensure that designated species and areas are protected or improved to achieve favourable condition. Any airport developments will need to take account of designated habitats (European, National and local) and species.

In the south east, for example, of the 136,000 hectares of nationally designated Sites of Special Scientific Interest, 90% are in favourable or unfavourable recovering condition. And under the Water Framework Directive 38% of waters are in good status for fish. These indicators have shown gradual improvement over the last few years and it is important that future airport development does not threaten this recovery. Of particular importance in coastal or estuary areas is the potential for disruption to migratory birds, fisheries and fish nursery grounds.

1 Clearing the air The Mayor’s Air Quality Strategy 2010

2 Derivation criteria for Review and Assessment of Airports––2008 update. 2008. Air quality consultants Ltd. Bristol

3 Assuming a 50% conversion of nitrogen oxides to nitrogen dioxide and a nitrogen dioxide deposition velocity of 0.0015m/s.

Prepared 31st May 2013