Examination of Witnesses (Questions 6960
- 6979)
6960. So you have presented no written documentation
to the Promoter on that. The first the Promoter heard of your
views on that was when you gave evidence-in-chief some moments
ago. Is that correct?
(Mr Methold) I think my slide makes it clear
that I have done a cost analysis.
6961. So there has been no discussion about
the evidence that you have given on costs with the Promoter?
(Mr Methold) No.
6962. That puts me in a slightly difficult position
in respect of cross-examination, but I will do my best anyway.
You mentioned that there were some limitations to the exercise
that you had undertaken. I think you said that you had not examined
the implications for the air flow within vents and whether that
would be sufficient for the mitigation of noise—
(Mr Methold) That is outside my speciality.
6963. So there is the potential, is there not,
for additional costs to be imposed to deal with that sort of issue?
(Mr Methold) There is potential but I think
that with the magnitude of additional mitigation that I have come
up with in these vent shafts, actually it is unlikely that it
would be an issue. I have a specialist in this area who works
in the organisation who has been looking at this and without getting
too technical there are various issues, such as back pressure
that he is more than familiar with, that he is fairly confident
that we have not erred in favour of the Petitioner, so to speak.
6964. One last aspect in relation to the plus
five/minus five debate, if I can call it that: you have received
a copy, I believe, of the draft information paper that has been
prepared. That is set out in P75 at page 118. I wanted to draw
your attention to paragraph 2.12 of that document, which we see
on page 120.[59]
It indicates that: "While the degree of attenuation required
is site dependent, not least because of different levels of background
noise at different sites, the nominated undertaker will be required
to use reasonable endeavours when designing the shafts to reduce
the noise below the assessment criterion where it is practicable
to do so." You understand what is being proposed there is,
essentially, that the plus five figure is not a target and that
where it is possible to have levels where the difference is significantly
below plus five, reasonable endeavours will be used to achieve
that. Do you understand that aspect?
(Mr Methold) I do understand that
aspect. I am concerned about the phrase "reasonable endeavours".
6965. Indeed, we know, do we not, from your
own evidence in LBH47, where you have identified 16 out of the
26 vent shafts already would achieve differences below your minus
five criterion level.[60]
Yes?
(Mr Methold) Correct.
6966. That indicates that the Promoter is already
adopting the approach set out in the draft IP.
(Mr Methold) I think it shows that the Promoter—and
this was actually stated at the meeting we had recently—has
really just used the Environmental Statement to identify whether
their design standard of L90+5 can be achieved. I do not think
there is any commitment at all to reducing below that. I am concerned
about the use of "reasonable endeavours" and what that
actually means in practice. My view is that you can use reasonable
endeavours and still only have to meet L90+5, but this is a draft
information paper and I would like to explore that further.
6967. That is why it is in draft, so that we
can continue discussions and, hopefully, achieve a measure of
agreement in the future. Let us move on to deal with your point
about background noise levels, if I may, briefly. Am I right in
thinking that the background ambient noise levels change over
time?
(Mr Methold) Yes, they do.
6968. So it would be right, would it, to carry
out measurements of background in the future prior to the design
process starting in order to take into account those sorts of
changes?
(Mr Methold) Absolutely expected, yes.
6969. So the right approach to the design process
for fixed installations, in relation to Crossrail, would be to
establish at an appropriate time in the future what the background
noise levels are in each location.
(Mr Methold) Correct.
6970. The draft IP that has been produced indicates,
does it not, at paragraph 2.14, page 120 again: "The nominated
undertaker will be required to determine the relevant LA90 levels
to be jointly established with the relevant local authorities."[61]
Now, if that is the approach that is adopted that meets your concerns
about the identification of the appropriate background level.
(Mr Methold) It meets my concerns
at the design stage; it does not meet my concerns about the information
that has been presented in the Environmental Statement, which
is still based upon this modal value of background noise level.
As I said in my evidence, I believe that is has serious and significant
impacts which the Environmental Statement has a duty to report
at this stage or to present to the decision-maker.
6971. So you are saying there will be circumstances
where the plus five criterion cannot be met?
(Mr Methold) I believe there is, yes. Well,
where the plus five criterion would not be met according to the
Promoter's calculated levels at present without further mitigation
applied.
6972. So with further mitigation plus five levels
can be met in all locations.
(Mr Methold) It may well be but we do not know
that. The Environmental Statement does not tell us that.
6973. If the plus five level is adopted as the
level of significance (and I do not disagree with that), on that
assumption that would mean there would be no significant impacts
arising from fixed cost installations.
(Mr Methold) With a mystery level of mitigation
incorporated.
6974. Let us deal with Thameslink 2000. That
project does not involve any new tunnelling.
(Mr Methold) It does not.
6975. It does not involve the creation of any
new vent shafts that are ventilated by fan, as I understand it.
Is that correct?
(Mr Methold) As far as I understand, yes.
6976. It does not involve the provision of new
maintenance depots.
(Mr Methold) No, it does not.
6977. It does not involve the provision of new
stations.
(Mr Methold) I do not think so, no.
6978. It would be right, given those differences,
to recall that the fixed installations involved in the Thameslink
2000 project are of a different kind to those provided in relation
to Crossrail.
(Mr Methold) I think that what we have to be
very clear about is that Thameslink have, essentially, justified
L90-5 on acoustical grounds. They have agreed this with the local
authorities, they have done their own review of the guidance that
I have taken you through today and they have concluded that L90-5
is an appropriate acoustical target to meet. That is important.
That is why I have a problem with the Promoter suggesting that
they need to go into something else than ventilation shafts because
it conflicts with the whole premise that the acoustical target
should be moved.
6979. Did the promoter of Thameslink 2000 form
that view in relation to all forms of fixed installations, or
did they form a view in relation to—
(Mr Methold) I do not know. I was not party
to those discussions, I am afraid.
59 Crossrail Ref: P75, draft Information Paper, Noise
from Fixed Installations (HAVGLB-14704-120). Back
60
Committee Ref: A81, Achievability of Alternative Design Aim (HAVGLB-14705-047). Back
61
Crossrail Ref: P75, draft Information Paper, Noise from Fixed
Installations (HAVGLB-14704-120). Back
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