FOI request detail

Air quality assessments and/or modelling report

Request ID: FOI-0081-1920
Date published: 07 May 2019

You asked

Dear Sir/Madam, Under the terms of the Freedom of Information Act (2000), I would like to request the most recent air quality assessments and/or modeling for each station on the Elizabeth Line route. For the sake of clarity, this request is an attempt to gather information for passengers as they use the Elizabeth Line only. Please provide information on this line, as opposed to any other lines which interchange at stations.

We answered

TfL Ref: FOI-0081-1920

Thank you for your email received by Transport for London (TfL) on 8 April 2019.

Your request has been considered in accordance with the requirements of the Environmental Information Regulations (EIR) and our information access policy. You asked:

Under the terms of the Freedom of Information Act (2000), I would like to request the most recent air quality assessments and/or modelling for each station on the Elizabeth Line route.  For the sake of clarity, this request is an attempt to gather information for passengers as they use the Elizabeth Line only.  Please provide information on this line, as opposed to any other lines which interchange at stations.

Unfortunately we do not hold the information you have requested. No such reports exist.

However, the air quality impacts associated with the operation of Crossrail were assessed and the results presented in the Crossrail Environmental Statement available at http://www.crossrail.co.uk/about-us/crossrail-bill-supporting-documents/environmental-statement. Crossrail is a modern electrified railway and will be replacing a large proportion of what were previously diesel train services with new electric trains. Taken overall therefore Crossrail will result in a benefit in air quality terms although impacts at the localised level will be small. Given that the models used predict that Crossrail will encourage a degree of mode shift from private vehicles to public transport there should also be an improvement at roadsides at the local level, but this was not found to be significant. 

The air quality experienced by passengers using the surface stations of Crossrail will be determined by the local air quality at those locations which will be determined for the most part by local road traffic. With respect to the central tunnel sections underground spaces will be ventilated by air drawn in from the surface. At the platform level air will be drawn in as trains pull into stations and at the same time pushed back out by what is called the piston effect using draught relief shafts. There will also be ventilation shafts and systems in operation at certain times but all of these will be either drawing in surface air or expelling subsurface air back to the surface.  This is a system in use throughout London Underground’s tube network and other subsurface railways in London such as sections of High Speed 1. The Environmental Statement noted the following in relation to the potential air quality impacts of air expelled from Crossrail shafts:

The only permanent source of air pollution directly from Crossrail is the ventilation shaft and the potential for PM10 arising from train operations and passenger movements being emitted at this point. Monitoring at a ventilation shaft on the Jubilee line recorded no significant emissions of PM10. Crossrail tunnels will be cleaned on a regular basis, Crossrail trains will use regenerative braking reducing the potential for generation of particulates, and station platforms will be partitioned from the main tunnels. On this basis it is considered that no significant impacts from emissions of PM10 through Crossrail ventilation shafts will occur”.

Further information on the monitoring referred to can be found in the ‘Assessment of Atmospheric and Air Quality Impacts Technical Report, Volume 1, Appendix D, available at http://www.crossrail.co.uk/about-us/crossrail-bill-supporting-documents/specialist-technical-reports/?folder=/l0/368#1. 

Given the nature of the air quality which is expected to be experienced by passengers using the underground sections of Crossrail, no subsequent air quality modelling work has needed to be carried out and thus there are no reports of the nature you describe that we hold. 

Please see the attached information sheet for details of your right to appeal.

In the meantime, if you would like to discuss this matter further, please do not hesitate to contact me.

Yours sincerely

Eva Hextall

FOI Case Officer

FOI Case Management Team

General Counsel

Transport for London

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