Airports Commission consultation shows air quality problems with new runways, but no adequate data yet
The Airports Commission consultation document is aware that air quality is a major obstacle for a new Heathrow runway. It says expanding either Gatwick or Heathrow would have a negative impact on air quality, with all proposed schemes requiring expansions to local road networks to accommodate increased road traffic. For both the Heathrow runway options the Commission says “Both local Air Quality Objectives and EU limit thresholds are at risk of exceedance at a small number of monitoring sites in the local area under this scheme. While in some cases these exceedances are also forecast to occur in the do minimum scenario, there is clearly a substantial negative impact of the scheme on air quality, unless forceful mitigation measures are implemented.” But they have not been able to complete full detailed modelling of the air quality impacts of new runways and further work is needed. This unfortunately is not in time for the consultation. The Commission intends to supplement this at a future date with “more detailed dispersion modelling”. That means models to show how wind and weather disperses pollution, and it could be questioned how much faith should be placed on sufficient wind speeds in coming years.
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Air quality impacts of UK airport expansion assessed
November 14, 2014 (Air Quality News)
The Airports Commission states that expanding either Gatwick or Heathrow would have a negative air quality impact, but plans more detailed modelling.
The independent Airports Commission has launched a consultation on options for a new runway at either Heathrow or Gatwick, alongside a report which assesses the possible air quality impacts of each scheme.
And, while the Commission has not yet made any specific recommendations, it states that expanding either Gatwick or Heathrow would in either case have a negative impact on air quality, with all proposed schemes requiring expansions to local road networks to accommodate increased road traffic.
Two of the proposed schemes would see an expansion of Heathrow Airport
However, while the Commission believes the air quality modelling information it has so far provided gives a “sufficient evidential basis for consultees to express their views”, it has yet to complete its full detailed modelling of the air quality impacts of airport expansion.
Launched this week (November 11), the consultation will run for 12 weeks and closes on February 3 2015. It concerns three options for a new runway in the South East of England: a second runway at Gatwick; a North West runway at Heathrow; and the extension of the Heathrow Northern runway.
The Commission forecasts a third runway at Heathrow would cost £18.6 billion, extending the northern runway would cost £13.5bn, and a second Gatwick runway would cost £9.3bn (£7.4bn).
Chair of the Airports Commission, Sir Howard Davies, said that it had “not yet taken a view on which proposal strikes the most effective balance between the assessment criteria” but that the consultation provided an opportunity for the evidence to be “examined, challenged and improved”.
Commenting on the consultation launch, Sir Howard said: “Responses to this consultation will be a valuable addition to our evidence base and will directly inform our recommendation to the government when we publish our final report in the summer of 2015.”
Heathrow
The report adds that for both schemes “there is clearly a substantial negative impact of the scheme on air quality, unless forceful mitigation measures are implemented”.
King’s College London annual nitrogen dioxide monitoring data for 2010 shows that levels of the pollutant breached annual limits of 40 microgrammes per cubic metre in and around Heathrow, which scientists at the university have said is largely due to road traffic.
Furthermore, a King’s College map depicting air pollution levels in Greater London shows that Heathrow has the highest levels of nitrogen dioxide outside the centre of the capital.
According to the Airport Commission’s report published this week: “significant works are needed on the roads around the airport site to accommodate its expanded footprint including putting the M25 into a tunnel.”
The report states that the management of congestion on the M25 and the M4 near Heathrow “will be a significant issue and infrastructure (including widening), demand management or a combination of both may be required”.
However, it adds that “the majority of these strategic road works would be needed even without any expansion, given baseline expectations about increase in demand”.
In addition, the report also suggests that some additional widening of the M4 may be needed as a result of expansion, but that “it may be possible to avoid of reduce this through mitigation measures”.
The Mayor of London is opposed to Heathrow airport expansion and has previously highlighted the impacts on air quality of such a scheme, as has Friends of the Earth London campaigner Jenny Bates, who said this week that expanding Heathrow “would bring more noise and pollution to local communities”.
Gatwick
Expansion of the airport at Gatwick would, according to the report, have a “negative impact on a range of other local environmental factors, including air quality” and adds that “impacts in some cases will never be entirely mitigated”.
However, the report states that with regards to air quality “further work is required to fully quantify the limited risks”.
Regarding the impacts on road traffic around Gatwick, the report states: “Planned and anticipated (though uncommitted) investment on the M23 and M25 is also forecast to provide sufficient capacity to accommodate growth in road traffic from the expanded airport. A range of investments in the local road network would be needed to enable the delivery of the second runway and associated infrastructure.”
Detailed modelling
According to the Commission’s report this week, the dispersion modelling “will provide greater assurance in respect of the air quality implications of each proposal and the scope for mitigation”
But, the Commission said that the “range of inputs required and the complexity of this work mean that it has not been possible to carry it out in advance of consultation”.
The report adds: “It is acknowledged it would have been preferable to have available the outcome of more detailed modelling exercises prior to consultation. On balance, however, the Commission considers that it is better to launch the consultation phase of its work at the present time (enabling sufficient time for participation in the process and for consideration of the outcome of those responses), than to hold off the consultation process in an attempt to achieve a firmer foundation for its air quality assessments.”
The Airports Commission documents on air quality:
The main consultation document
Consultation document (updated 25 November 2014)
Baseline
Baseline figures
National and local assessment
National and local assessment figures
Mentions of air quality in the main consultation document are copied below:
policy requirements.”It states (2.55):
” For its air quality assessments the Commission has used the
forecasts to predict the mass emissions of harmful compounds associated with
airport expansion, and has then considered the impacts of these emissions at a
national and local level. It has carried out a high-level assessment of local impacts
and the risks of exceeding legislated air quality limits, as well as considering the
scope for mitigation. “(2.56):
“The high-level air quality modelling presented for consultation enables a comparison
to be made of the scale of impacts and risks associated with each option. Prior to
reaching any final recommendations, the Commission intends to supplement this with
more detailed dispersion modelling, as set out in its Appraisal Framework, which will
provide greater assurance in respect of the air quality implications of each proposal and
the scope for mitigation. The range of inputs required and the complexity of this work
mean that it has not been possible to carry it out in advance of consultation”(2.57):
“It is acknowledged it would have been preferable to have available the outcome of
more detailed modelling exercises prior to consultation. On balance, however, the
Commission considers that it is better to launch the consultation phase of its work
at the present time (enabling sufficient time for participation in the process and for
consideration of the outcome of those responses), than to hold off the consultation
process in an attempt to achieve a firmer foundation for its air quality assessments.
Although a fuller picture may be provided by more detailed work, the high level
modelling undertaken to date identifies the key challenges which shortlisted
schemes face and provides a sufficient evidential basis for consultees to express
their views on the questions asked in the consultation document. The Commission
is continuing to work in this area and it is anticipated that fuller work will inform its
final recommendations.”
(3.35 – about Gatwick):
“Expansion would have a negative impact on a range of other local environmental
factors, including air quality, landscape, heritage, biodiversity and water. In general
while good detailed design and operational delivery by the airport operator could
significantly reduce the impact of the scheme, the impacts in some cases will never
be entirely mitigated. However, the mitigated impacts are not predicted to exceed
domestic or international regulations, except in the case of air quality where further
work is required to fully quantify the limited risks. ”
(3.87 – Heathrow Hub):
“Both local Air Quality Objectives and EU limit thresholds are at risk of exceedance
at a small number of monitoring sites in the local area under this scheme. While
in some cases these exceedances are also forecast to occur in the do minimum
scenario, there is clearly a substantial negative impact of the scheme on air quality,
unless forceful mitigation measures are implemented. As explained at paragraph
2.56-7 above, further work on this issue is ongoing.”
Identical paragraph as above
(3.139 – Heathrow new North West runway):
“Both local Air Quality Objectives and EU limit thresholds are at risk of exceedance
at a small number of monitoring sites in the local area under this scheme. While
in some cases these exceedances are also forecast to occur in the do minimum
scenario, there is clearly a substantial negative impact of the scheme on air quality,
unless forceful mitigation measures are implemented. As explained at paragraph
2.56-7 above, further work on this issue is ongoing. ”
(3.155):
“Impact of mitigations on noise and air quality impacts: Heathrow Airport
Ltd has proposed a range of measures, such as operational mitigations or
financial incentives, to mitigate adverse noise and air quality impacts. Not all of
these mitigations have informed the Commission’s quantitative assessments,
but the Commission has considered these potential mitigations when evaluating
the scheme.”
and
“Heathrow Airport Ltd’s updated scheme design modelled
a phased release of the new capacity provided by its scheme. This phased
release has the effect of tempering the environmental (particularly air quality and
noise) impacts of expansion, which may be necessary if the airport and environs
have to adhere to environmental impact limits”
The report, by Jacobs, on Air Quality: Baseline is described as:
“Report on the expected developments in air quality over a 60 year period in the vicinity of Heathrow and Gatwick, considering airport operations, airport surface access and background users of surface access networks, on the basis of a “do minimum” scenario with no airport expansion.”
The report, by Jacobs, on Air Quality: National and Local Assessment is described as:
“Jacobs Report on the implications of schemes for both air quality in the vicinity of Heathrow and Gatwick airports and for national air quality levels, appraised across a 60 year period.”
Atmospheric dispersion modeling
Atmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. It is performed with computer programs that solve the mathematical equations and algorithms which simulate the pollutant dispersion. The dispersion models are used to estimate or to predict the downwind concentration of air pollutants or toxins emitted from sources such as industrial plants, vehicular traffic or accidental chemical releases.Such models are important to governmental agencies tasked with protecting and managing the ambient air quality. The models are typically employed to determine whether existing or proposed new industrial facilities are or will be in compliance with the National Ambient Air Quality Standards (NAAQS) in the United States and other nations. The models also serve to assist in the design of effective control strategies to reduce emissions of harmful air pollutants. Atmospheric dispersion models are also known as atmospheric diffusion models, air dispersion models, air quality models, and air pollution dispersion models.
Numerical Atmospheric-dispersion Modelling Environment (NAME) is a local to global scale model developed by the UK’s Met Office. It is used for: forecasting of air quality, air pollution dispersion, and acid rain; tracking radioactive emissions and volcanic ash discharges; analysis of accidental air pollutant releases and assisting in emergency response; and long-term environmental impact analysis. It is an integrated model that includes boundary layer dispersion modelling.
http://en.wikipedia.org/wiki/Atmospheric_dispersion_modeling and http://en.wikipedia.org/wiki/List_of_atmospheric_dispersion_models
Air pollution has always been the insurmountable problem Heathrow expansion has faced. By delaying pollution modelling exercises until now, it is clear that the Davies Commission is trying its best to justify the unsustainable expansion of Heathrow. The ridiculous concept that dispersion through variable weather patterns (that are changing due to climate change) can be defined is as fanciful as the concept that Heathrow can be expanded without significant environmental costs. The headline development costs are misleading. The only part of development costs that should be considered by Davies are those involving public expenditure and not those of the private companies (overseas owners) who own the airports.