Select Committee on Crossrail Bill Minutes of Evidence


Examination of Witnesses (Questions 5820 - 5839)

  5820. Turning to mitigation measures at the receptor end, on the screen is the noise and vibration mitigation scheme Information Paper D9.[6] What are the mitigation measures that are proposed at that stage of the works?

  (Mr Thornely-Taylor) The noise and vibration mitigation scheme effectively puts into practice the discretionary power to provide noise insulation from construction noise that appears in the noise insulation regulations for railways. The works included are specified in those regulations and in short they are the provision of secondary glazing, the provision of a noise attenuated ventilator and, in appropriate circumstances, secondary doors, and in the space between the two panes and secondary glazing there is provision for Venetian blinds to reduce solar gain.

  5821. In terms of the mitigation you have just described what is it intended to achieve in terms of the internal noise environment within the affected properties?
  (Mr Thornely-Taylor) I will answer that in two ways. One is an historical one in that all these insulation schemes have been introduced with the intention of applying them equitably across major infrastructure schemes. The original one was highways and the purpose was to provide noise mitigation when the predicted noise exceeded the acceptable. Put in more general terms, the objective is to make it possible to continue to occupy a building in a reasonable manner throughout the works without unacceptable interference by noise.[7]


  5822. In circumstances where even if such insulation measures were provided and taken up that objective would still not be achievable is there any further mitigation that the Promoter is proposing to offer?

  5823. (Mr Thornely-Taylor) The further mitigation is the temporary re-housing scheme when, even after providing secondary glazing, the internal noise levels would not meet the criteria I have just mentioned and then temporary re-housing would be offered.

  5824. By what criteria is the judgment made as to whether either noise insulation package or in appropriate cases temporary re-housing is offered to affected householders?
  (Mr Thornely-Taylor) There is a formal process which takes place much closer to the start of construction than we are now when the contractor is known, his methods of working are known and detailed predictions are made and it is set out in an appendix to Information Paper D9, a very formal process for identifying whether or not the noise will exceed bigger levels for the required duration.

  5825. Mr Mould: Are those levels prescribed noise levels which effectively operate as a trigger in relation to eligibility for noise insulation or, in appropriate cases, temporary re-housing?
  (Mr Thornely-Taylor) Yes, they are.

  5826. That being the mechanism, is it appropriate that there should be some arbitral regime in relation to eligibility for one or other or both of those packages of mitigation?
  (Mr Thornely-Taylor) Effectively, there are two stages to that. There is a procedure for applying to the Secretary of State if a person believes they should be entitled and have not been offered either noise insulation or temporary re-housing. Should the Secretary of State decline that application and the person applying feel aggrieved, there is the separate process of the Independent Complaints Commissioner, who would be available to receive a complaint of that kind.

  5827. For the Committee's note, that is information paper F5.[8] Finally on noise and vibration mitigation, does that reflect a model that has been deployed effectively in relation to other major infrastructure projects?

  (Mr Thornely-Taylor) It is very similar, differing only in detail, to those used for the Jubilee Line extension and the Channel Tunnel Rail Link, to name but two of the major recent infrastructure projects.

  5828. Can we just pick up on the position in relation to Mr and Mrs Ennals at 69 Hunter Avenue?[9] On present assessment, can you help us with their eligibility for one or other or both of those mitigation packages?

  (Mr Thornely-Taylor) If I remember rightly, Mr and Mrs Ennals live two houses away from the north-eastern end of the work site. I think it is the right of those two houses.

  5829. I think it is the property which is adjacent to the north end of the works.
  (Mr Thornely-Taylor) I have a feeling the arrow needs to move one house to the right, as I heard the evidence. Those two houses are currently identified in the Environmental Statement as being eligible for noise insulation. As I have mentioned, that is not by any means the beginning and end of the story. The actual entitlement procedure will be gone through much closer to the start of the works.

  5830. Thank you very much indeed for that. Finally, turning from construction noise to operation noise, so the railway is up and running, trains coming in and out of Shenfield, can you tell the Committee what the results of the environmental assessment process were in relation to the impact of Crossrail at that stage?
  (Mr Thornely-Taylor) Yes. There is a statutory procedure for calculating railway noise which was used in the preparation of the Environmental Statement. Taking account of the changes in train numbers, the revision of the track layout and the new train services, the change in noise level was predicted, and in all cases was found to lie well below the threshold of significant effect as set out in the Environmental Statement.

  5831. What is the dominant noise environment for those living within 100 or so metres of the railway line at the moment?
  (Mr Thornely-Taylor) Train noise is the major source for the properties that are considered for potential significant effects. The levels are not excessively high. They are set out in the environmental statement, but it is the main noise source in the area, except for those very close to the road, who may have more traffic noise than train noise.

  Cross-examined by Mr Welfare

  5832. Mr Welfare: Mr Thornely-Taylor, in response to Mr Mould, you described to the Committee a moment ago the position of significant effects being the basis of the noise assessment over a distance and the factor of length of time, and you pointed to the fact that audibility is not the same as significance, and you have helpfully clarified that the elevated area of the Shenfield area is outside what are regarded as significant effects.
  (Mr Thornely-Taylor) Yes.

  5833. It follows from that, does it not, that noise disturbance, be it during the construction period or during the operation thereafter, in terms of what individual people suffer in their houses, can take place with no compensation arrangements at all?
  (Mr Thornely-Taylor) Yes, it can.

  5834. In fact, just to reinforce that point, you have said that the distance involved was the distance within which there was the need to restrict the work of computation so that one could be sure that there would be effects. In other words, you start from the position of over what area can we be certain there will be noise effects and measure within that area, and you treat those outside that area as not falling within significant effects. Is that right?
  (Mr Thornely-Taylor) It is the other way round. The distance is chosen so that one can be certain it includes significant effects. If for some extraordinary reason one found significant effects going over the edge of the spatial boundary, then it would be necessary to go back and change the spatial limits, but that has not happened.

  5835. Would you care to explain to the Committee how the significant effects are determined?
  (Mr Thornely-Taylor) Yes. They are determined according to whether or not the noise would exceed either a minimum trigger level or significance or a change in the total noise level relative to the baseline, ambient noise as set out in the scope of methodology of the ES.

  5836. Can you give the Committee some idea of the basis of a significant level of noise?
  (Mr Thornely-Taylor) There is detailed explanation of the thought processes that underlie it in Appendix D of the special technical report, which can be found on the internet, but it is traceable to guidance from documents published by the World Health organisation, British Standards, and current practice in environmental assessment. They are very well established sets of numbers.

  5837. I do not disagree with what you are saying in terms of there being well established sets of numbers, but from the point of view of an ordinary resident who seeks to understand what the Promoters regard as a significant effect or what indeed is to be generally regarded as a significant effect, where in what Crossrail have put forward so far to individual residents has there been an explanation of what significance can be expected and what levels of noise people will have to put up with?
  (Mr Thornely-Taylor) In the Environmental Statement.

  5838. Yes, but in terms of trying to give people an understanding of what that amounts to, are you satisfied that residents have been put in a position to understand in plain terms what levels of noise they will be expected to accept?
  (Mr Thornely-Taylor) It was clear to me, listening to petitioners yesterday, that there is some misunderstanding and there may be some confusion between audibility and significance.

  5839. In other words, residents may have to put up with a degree of noise which is not significant?
  (Mr Thornely-Taylor) They will, yes.


6   Crossrail Information Paper D9, Noise and Vibration Mitigation Scheme (LINEWD-IPD9-001). Back

7   Crossrail Information Paper D9, Noise and Vibration Mitigation Scheme (LINEWD-IPD9-002-005). Back

8   Crossrail Information Paper F5, Complaints Commissioner (LINEWD-IPF5-001). Back

9   Crossrail Ref: P70, Plan & Map of Hunter Avenue, Alexander Lane, Herrington Grove, Mount Avenue & Pine Croft (Location of Petitioners) (BRWDBO-14903-008). Back


 
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