2. Extending the runway and increasing runway capacity will expose more people over a wider geographical area to significant aircraft noise pollution.
Measuring aircraft noise
The strength of a source of noise such as an aircraft is measured in decibels (dB). In the case of UK airports, electronic monitoring stations record the sound level of each aircraft movement over the 16-hour period 0700h-2300h (local time). These readings are then averaged to give an 'equivalent continuous noise level' or Leq for short. An 'A-weighting' is added to the reading to simulate the way in which the human ear responds to a range of sound frequencies.
The UK government considers that, while individual responses to noise can vary markedly, a long-term average aircraft noise level of 57 dBLAeq represents the ‘onset of significant community annoyance’. However, the 2007 'Attitudes to Noise from Aviation Sources in England' (ANASE) study for the DfT found that for the same amount of aircraft noise, measured in LAeq, people today are more annoyed than they were in 1982 when the last major study of this kind was conducted. [1]
The World Health Organisation (WHO) suggests lower guideline values for annoyance, with between 50 and 55 dBLAeq 'representing daytime levels below which a majority of the adult population will be protected from becoming moderately or seriously annoyed, respectively.' [2] In addition, WHO recommends that noise levels during the evening and night should be 5‐10 dBLAeq lower than during the day, and that where the source of noise has a low-frequency component, which aircraft noise does, the levels should be even lower. [3]
The impact of BIA's expansion
Leq readings are used to plot 'noise contours', lines on a map joining points of equal noise exposure, similar to the lines joining points of equal height above sea level on an Ordnance Survey map. Airport noise contour maps are produced independently by the Civil Aviation Authority's Environmental Research and Consultancy Department (ERCD). A computer model developed by the ERCD, called ANCON (Aircraft Noise CONtour model), calculates the contours from data describing aircraft movements, routes, noise generation and sound propagation. ANCON is also used to forecast the noise impact of airport developments or changes to air traffic operations.
As part of the work leading up to the publication of the 2007 Master Plan, BIA Ltd commissioned the ERCD to undertake an Air Noise Study of the airport's expansion plans, including the Runway Extension. The table on page 81 of the Master Plan summarising the results of the Study reveals that the number of people exposed to aircraft noise in the 57 dBLAeq noise contour is predicted to rise from 26,800 in the daytime and 5,100 at night in 2006 to 55,150 in the daytime and 9,000 at night by 2030.
'The increase in Air Transport Movements from 2012 through to 2030 leads to an increase in populations exposed to corresponding day and night noise contours.' [4]
The noise contour map below was included in a presentation provided by the airport company to IMPACT, the University of Liverpool's International Health Impact Assessment Consortium, for use at a series of consultation workshops in local communities during September 2007. The map illustrates how the 57 dBLAeq noise contour is likely to grow in the years leading up to 2030.
What's clear is that aircraft noise pollution from BIA is set to grow over the next twenty-five years regardless of whether the runway is extended or not. This is because the main function of the Runway Extension is to improve runway capability, increasing the range of destinations and routes which can be served from Birmingham. It does not in itself increase runway capacity, defined as the number of air transport movements (ATMs) the runway can handle per hour at peak times.
The peak hourly capacity of the current runway is 40 ATMs per hour. BIA Ltd intends to increase this figure to 48 ATMs per hour by adding more taxiway links, fast turn-off taxiways and rapid-exit taxiways to the airfield layout. As the airport moves to a 'fully-coordinated runway movement scheduling status', it will be 'necessary to operate at the peak hour capacity for significant periods during the day'. [5] It is this increase in the capacity of the runway that accounts for much of the growth in the size of the noise contours over the period to 2030.
The impact of the Runway Extension
This is not to say that the Runway Extension will make no difference to the noise impact of the airport. On the contrary, operating a longer runway will mean closer and lower flights over residential areas [6] and the use of larger, and therefore noisier, aircraft. In addition, certain airport operational procedures designed to reduce noise, such as the 'Hampton Turn', the southerly departure route which takes planes away from the village of Hampton-in-Arden in Solihull, will no longer be possible with a longer runway. The Master Plan states that in terms of noise,
'The main impact is the proposed extension of the Main Runway, which would necessitate the discontinuance of the existing noise abatement procedures of Runway 15 departures, including the 'Hampton Turn' introduced prior to the elimination of the noisier "Chapter 2" aircraft types'. (emphasis added)[7]
The Environmental Statement for the Runway Extension produced for BIA Ltd by Ove Arup & Partners (Arup) and submitted as part of the planning application to extend the runway includes details of the results of the ERCD's Air Noise Study. ERCD modelled two expansion scenarios, the 'with runway extension' scenario, in which the airport begins operating the extended runway early in 2012, and the 'no runway extension' scenario, in which the airport continues to expand its operations up to 2030 without extending the runway. [8]
Under the 'with runway extension' scenario the 57 dBLAeq daytime noise contour is forecast to grow to encompass an extra 8,100 people and 3,450 households by 2030, compared with the 'no runway extension' scenario. [9] The corresponding night-time 57 dBLAeq noise contour on the other hand is forecast to encompass 750 fewer people and 250 fewer households compared with the 'no runway extension' scenario [10], although the population exposed to night-time aircraft noise at this level is set to increase from 5,400 people and 2,400 households in 2012 to 9,000 people and 4,000 households in 2030 under the 'with runway extension' scenario. [11]
Technology and sound insulation. Solutions?
Despite individual aircraft having become considerably less noisy over the years, we cannot rely on technology alone to solve the growing noise problem. Since the introduction of the first jets the noise reductions achieved through incremental refinement of aircraft engine and airframe design have tended to be offset by the introduction of larger aircraft, more frequent flights (often at sensitive times of day) and growing community expectations.
In 2000, the Advisory Council for Aeronautical Research in Europe (ACARE) set an ambitious target to reduce perceived aircraft noise by 50 per cent of 2000 levels by 2020. But even if manufacturers can deliver the technology in time, which is by no means certain, the absence of regulation requiring airlines to phase out older, noisier planes from their fleets means that uptake of new quieter aircraft is likely to be too slow to prevent the number of people exposed to significant aircraft noise continuing to grow. [12] What's more, some of the technological measures which might reduce the climate-change impacts of aviation could increase noise or air quality problems, and vice versa. [13]
The noise mitigation measures offered by airport operators can help reduce the impact on communities, but they go nowhere near far enough. BIA Ltd operates a Sound Insulation Scheme for local homeowners, providing high specification double or secondary glazing with mechanical ventilation and loft insulation to reduce the impact of aircraft noise. But this scheme only covers properties located within the 63 dBLAeq noise contour, despite the fact that 'significant community annoyance' is widely considered to begin at 57 dBLAeq. This means that although the Runway Extension will expose 3,450 more households (compared with under the 'no runway extension' scenario) to 'significant' daytime aircraft noise by 2030, only 800 households would become eligible for sound insulation under the present scheme. [14]
The WHO recommends that noise abatement measures should also take into account residential outdoor as well as indoor activities, [15] but as local residents have pointed out, 'you can't double-glaze a garden.'
The right comparison
In the face of evidence that expanding the airport will have a significant noise impact, BIA Ltd insists that its proposals are compatible with the company's official policy of 'continuous environmental improvement'. [16] The Master Plan states:
'The results of the ERCD Air Noise Study show that, whilst the noise contours have increased with air traffic growth up to 2030, the calculated noise impact is much lower compared with the 'Birmingham Alternative' and the Government Consultation document.' [17]
The 'Birmingham Alternative' was the airport company's response to the Government consultation document 'The Future of Air Transport in the United Kingdom: Midlands'. It proposed a shorter 'wide-spaced' second runway along with operational restrictions on the use of the runway aimed at reducing noise. The new Master Plan, however, does not include plans for a Second Runway whereas the 'Birmingham Alternative' and the Government consultation document both assumed that a BIA would be operating a second runway by 2016, so it's no surprise that the forecast noise impact of the current proposals is lower than previously predicted.
In any case, we would contend that the comparison that matters most to local residents living near the airport and under the flight path is the comparison between the airport's impact on their lives today and its likely impact in the future. Favourable though the comparison may be between the airport company's latest figures and those produced by the Government five years ago, it is hardly surprising, and merely pointing out the difference on paper does not amount to a credible strategy for 'mitigating' the environmental impact of the airport's expansion.
We believe that the local planning authority for the airport, Solihull Metropolitan Borough Council, must make the granting of planning permission for any development at BIA subject to the following condition: that the development will not result in a net increase in the size of the 57-dBLAeq noise contour relative to either (i) the size of the noise contour in 2002 or (ii) the size of the contour in a subsequent year, which ever is the smallest.
This condition is similar to the one the Government has placed on the expansion of Heathrow Airport. The 2003 White Paper stated that 'any further development [at Heathrow] could only be considered on the basis that it resulted in no net increase in the total area of the 57dBA noise contour compared with summer 2002, a contour area of 127 sq.km.' [18]
References
[1] Mva Consultancy, 'ANASE - Attitudes to Noise from Aviation Sources in England, Final Report for Department for Transport', October 2007, para.11.2.5, p11.1. www.dft.gov.uk/pgr/aviation/environmentalissues/Anase/
[2] Berglund, B., Lindvall, T., Schwela,D. H., (eds.), 'Guidelines for Community Noise', World Health Organisation, 1999, pp55-6. www.who.int/docstore/peh/noise/guidelines2.html
[3] Ibid., p60.
[4] Birmingham International Airport Ltd, 'Towards 2030: Planning a sustainable future for air transport in the Midlands', November 2007, para.9.12, p83. www.bhx.co.uk/Planning/351.pdf
[5] Ibid., para.7.2.38, p45.
[6] BIA's management acknowledged this concern, raised by Catherine-de-Barnes Residents' Association at the Airport Consultative Committee meeting of 23rd May 2007. www.ukaccs.info/bham/bhxaccminutes230507.pdf
See also 'Alarm as runway extension plan sparks fears that planes will be just 400ft overhead', icSolihull.co.uk, 16th January 2008. http://tinyurl.com/2w7abl
[7] Birmingham International Airport Ltd, op. cit., para.9.11, p83.
[8] Ove Arup & Partners, 'Birmingham International Airport Proposed Runway Extension Environmental Statement', January 2008, pp 72-9. http://tinyurl.com/34xd96
[9] Ibid., Table 6.14: Estimated Areas, Population and Households Within Year 2030 Average Summer Day Air Noise Contours, p78.
[10] Ibid., Table 6.15: Estimated Areas, Population and Households Within Year 2030 Average Summer Night Air Noise Contours, p78.
[11] Ibid., Table 6.11: Estimated Areas, Population and Households Within Year 2012 Average Summer Night Contours, p76, and Table 6.15: Estimated Areas, Population and Households Within Year 2030 Average Summer Night Air Noise Contours, p78.
[12] Tim Johnson & Peter Lockley, 'Emissions Impossible: An assessment of the noise and air pollution problems at Heathrow airport and the measures proposed to tackle them', Aviation Environment Federation, February 2006, pp8-9. www.aef.org.uk/uploads/EmissionsImpos.pdf
[13 ] Cairns, S. & Newson, C., 'Predict and Decide: Aviation, Climate Change and UK Policy', Environmental Change Institute, University of Oxford, September 2006, p10. www.eci.ox.ac.uk/research/energy/downloads/predictanddecide.pdf
[14] Ove Arup & Partners, op. cit., Table 6.14, p78.
[15] Berglund, B., Lindvall, T., Schwela,D. H., (eds.), op. cit., p60.
[16] Birmingham International Airport Ltd, op. cit., para.9.1, p79.
[17] Ibid., para.9.17, p83.
[18] 'The Future of Air Transport' White Paper, Department for Transport, December 2003, para.11.53. www.dft.gov.uk/about/strategy/whitepapers/air/chapter11thesoutheast