Examination of Witnesses (Questions 6980
- 6999)
6980. Let us turn to part b) of your proposed
undertaking which relates to the absolute levels. I have already
identified in that aspect of your draft undertaking that you advocate
design criteria of 45 dBA LAeq,5min at night and 50 dBA LAeq,1hr
for the day time. As I understand it, those figures are drawn
from the guidelines for community noise. Is that correct?
(Mr Methold) Not directly, no; they are drawn
from the PPC regulations, the technical guidance that goes along
with the PPC regulations, which recommend that rating levels to
those values are used for absolute noise levels from industrial
installations.
6981. I see. You have not produced the PPC guidance
here.
(Mr Methold) I have not, no.
6982. The reason I believe that the figures
were drawn from the guidelines for community noise becomes apparent
if we look at LBH20.[62]
We see there "Outdoor living area: moderate annoyance, daytime
and evening", 50 LAeq and "Outside bedrooms, sleep disturbance,
window open" 45 LAeq. Those are the same figures.
(Mr Methold) They are the same
figures.
6983. I just wanted to draw your attention,
if I might, to some passages within the Crossrail technical report
assessment of noise and vibration impacts, volume 1 of 8. It is
page 20.[63]
If we look at page 20 (this is under the heading of the World
Health Organisation) this part of the technical report is examining
the implications of the guideline levels that we have just looked
at. At paragraph 4.15 there is reference to the National Noise
Incidence Study 2000, which found a number of things, but at 4.16
we see that 55+3per cent of the population of England and Wales
live in dwellings exposed to day-time noise levels above the 55
dBA LAeq.
(Mr Methold) Yes.
6984. If we look at 4.17 we see, in relation
to the night time level, that 68+3per cent of the population in
England and Wales live in dwellings exposed to night-time noise
levels above the 45 dBA LAeq level. Yes?
(Mr Methold) Yes.
6985. We then go on to 4.18 to see reference
to a review of the health effects based noise assessment methods,
undertaken for the DETR in 1998. The conclusions of that review
are set out in 4.18, which says that: "Perhaps the main weakness
of both WHO-inspired documents is that they fail to consider the
practicality of actually being able to achieve any of the stated
guideline values." Turn over the page to page 21: "The
percentages exposed above the WHO guideline values could not be
significantly reduced without drastic action to virtually eliminate
road traffic noise and other forms of transportation noise (including
public transport) from the vicinity of houses. The social and
economic consequences of such action would be likely to be far
greater than any environmental advantages of reducing the proportion
of the population annoyed by noise. In addition, there is no evidence
that anything other than a small minority of the population exposed
at such noise levels find them to be particularly onerous in the
context of their daily lives."[64]
That was the conclusion of the review conducted for the DETR.
In the light of that, is it the case that you are seeking to use
criteria that could not be met generally without the consequences
identified in that report?
(Mr Methold) No, I do not believe
so. The situation where this applies is for vent shaft locations
predominantly, and here we already have noise levels far in excess
of these guideline levels already. The purpose of putting absolute
levels of 45 and 50 is to control any creep whatsoever at the
higher noise levels. If you limit your emissions from, say, a
vent shaft to the 45 at night it means you do not get an increase
in LAeq or L90 for the situations where the noise levels are already
high. Also, I have made the point already, those noise levels
are taken from Environment Agency guidance from the PPC regs.
6986. It is not national planning policy to
reduce ambient noise levels to the guideline values that you referred
to in your draft undertaking, is it?
(Mr Methold) No, it is not, but a review of
PPG24 undertaken by the Promoter's specialists indicated, or recognised,
that noise levels based upon the then WHO guidelines should be
used as absolute noise limits.
6987. It is not part of the Mayor's strategy
to reduce ambient noise levels to the guideline levels set out
in your draft undertaking.
(Mr Methold) To the WHO guideline levels?
6988. Yes.
(Mr Methold) No. I think I have made the point
they are not actually based on the WHO guideline levels. They
happen to be, coincidentally, the same.
6989. They are the same figures, are they not?
(Mr Methold) They are the same figures.
6990. If we turn to LBH29 and 30, where you
set out various design criteria that local authorities utilise,
and look through those, I am right, am I not, that it is not part
of any of the local authorities' design criteria that the levels
of 50 by day and 45 for night should be met within their areas?[65]
(Mr Methold) No, it is not.
6991. So the criteria that you are putting forward
in part b) is criteria which is not based upon national planning
policy, it is not based upon regional planning policy for London,
it is not based on any planning policy that you can refer to for
any of the local authorities that are you here representing. That
is right.
(Mr Methold) It is provided in guidance that
is applied to every major industrial installation that requires
a permit under the PPC regulations.
6992. Does Crossrail require a permit under
the PPC regulations?
(Mr Methold) It does not.
6993. Do you think that adopting design criteria
that would require "drastic action to virtually eliminate
road traffic noise and other transportation noise" might
be to place an unjustifiable obstacle in the way of development?
(Mr Methold) Could you repeat the question?
6994. Do you think that to adopt design criteria
that would require, in the words of the report I have taken you
to, "drastic action to virtually eliminate road traffic noise
and other transportation noise" might be to place an unjustifiable
obstacle in the way of development?
(Mr Methold) To eliminate it would be, yes.
6995. Can we turn to deal with background creep
very quickly, Mr Methold. As I understand it, the approach to
using BS4142 that you adopt is that the minimum background noise
level should be adopted as the background noise level. Yes?
(Mr Methold) Yes.
6996. If we turn to LBH40, you have set out
an indication on that graph as part of your analysis of modal
value.[66]
We see, in the middle of the page, "ventilation shafts assumed
to be inoperative". It is right, is it, that there is a significant
period of the night when the vent shafts will not operate?
(Mr Methold) I think that is the
case for the normal operation of the ventilation shafts. They
will be used, of course, during maintenance periods which will
be during the night, but we understand that they will be operated
to a much lower level.
6997. The minimum background noise level will
be at night when the vents are not operating. Is that right?
(Mr Methold) That is not what we are trying
to get at with our arguments on this case. We are—I have
already made the point—totally in agreement that there is
no point in looking at a background noise level for a situation
where the equipment will not be operating.
6998. If we went forward with Crossrail and
Crossrail was built, and a local authority were faced with an
application for a development which was noise creating which needed
to be assessed in accordance with BS4142 and the background noise
level had to be identified, on your approach the background noise
level at night that would be adopted would be that during the
period when the vent shafts were not operating.
(Mr Methold) Are you talking about the Crossrail
development?
6999. Yes.
(Mr Methold) That is certainly the case. That
is the case with all other projects. CTRL has actually used the
minimum period throughout the night, even though it acknowledges
it may not be operating ventilation shafts. So they have actually
gone to—
62 Committee Ref: A81, World Health Organisation Guidelines
for Community Noise 1999 (HAVGLB-14705-020). Back
63
Crossrail Ref: P75, Specialist technical reports, Assessment
of noise & vibration impacts, Volume 1 of 8 Introduction,
scope & methodology, World Health Organisation, billdocuments.crossrail.co.uk
(LINEWD-STR109-024). Back
64
Crossrail Ref: P75, Specialist technical reports, Assessment
of noise & vibration impacts, Volume 1 of 8 Introduction,
scope & methodology, World Health Organisation, billdocuments.crossrail.co.uk
(LINEWD-STR109-025). Back
65
Committee Ref: A81, Local Authority Standards and Guidance-Part
1 (HAVGLB-14705-029 and -030). Back
66
Committee Ref: A81, Analysis of Modal Value-30 Hyde Park Gardens
(HAVGLB-14705-040). Back
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