Gladiatorial games, part 18

(… continued from Gladiatorial games, part 17, posted on 26 Feb 2016).

When the time came for the Promoter’s Lead Counsel, Tim Mould QC, to address the points raised by Chiltern District Council (CDC)’s noise expert, Rick Methold, he asked his own expert acoustics witness, Rupert Thornely-Taylor, if, in the light of what he had heard from his counterpart, “whether there’s a case for reviewing the level of 50 that has been set [for the daytime lowest observed adverse effect level (LOAEL)] by the project hitherto”.

Unsurprisingly, Mr Thornely-Taylor didn’t think that there was a case for review on the basis that the 60dB LpAFMax LOAEL threshold that applies at night exhibits a “much greater” geographic extent – in other words many more receptors will be above the LAMax night LOAEL than the LAeq day LOAEL (see footnote 1).

Mr Thornely-Taylor, who usually speaks with a pronounced air of authority, did stumble at this point in that he referred to 60dB LpAFMax as being “a free field trigger, equivalent to 63 in front of a façade”. This is incorrect; Information Paper E20 clearly states that the 60dB LpAFMax threshold is a façade level equivalent to about 57dB when made as free-field measurement, and he was subsequent pulled up on this point by CDC’s counsel, Gwion Lewis, and Committee Member Sir Peter Bottomley (see footnote 2).

That Mr Thornely-Taylor was correct, at least, in his assertion that the night LAMax LOAEL is a more-stringent test than the day LAeq LOAEL has been confirmed by the evidence of petitioners appearing before the HS2 Select Committee (see footnote 3). However, I do not accept his conclusion that, because of this, the requested lowering of the daytime LOAEL “doesn’t actually have any consequence” (see footnote 4). On the contrary, what his observation clearly demonstrates is that the daytime LOAEL threshold is, as Mr Methold claims, set too high and is, in all probability, not going to be the first to be triggered, in practice.

Neither am I very impressed by Mr Thornely-Taylor’s assertion that “HS2 would be regarded as a very odd outlier if we ended up with a daytime LOAEL [at 45dB] so close to nigh time (sic) LOAEL [at 40dB]” (see footnote 5). Aesthetics aside, the relationship between day and night LOAEL should not be an issue, provided that the value chosen for each is the appropriate one – if the difference between the most appropriate values for the two turns out to be less than 10dB, then so be it. It is hardly to be expected that the day and night LOAELs, being derived from the consideration of different effects – one annoyance and the other sleep disturbance – will obligingly yield thresholds that satisfy Mr Thornely-Taylor’s view of balance. Besides, Mr Thornely-Taylor can hardly claim to occupy the moral high ground on this issue, since the values that HS2 Ltd has chosen for the LAMax LOAEL and the two LOAELs using LAeq are, by his own admission, somewhat out of kilter.

Whilst the final objection to reviewing the daytime LOAEL that Mr Thornely-Taylor put forward may not be the scrapings from the very bottom of the barrel, it is certainly, to my mind, far from compelling. Referring to the contribution to HS2 noise made by realigned roads he said, “it would be very much out of line with practice in the highway field to have a daytime LOAEL as low as 45” (see footnote 6).

So what was the point of this discussion about setting daytime LOAEL to an appropriate level, or as Committee Member Mark Hendrick MP uncharitably described it “all this stuff” (see footnote 7)? Mr Methold showed the Committee exhibit A1571(71) to illustrate that it really wasn’t just a matter of semantics. Mr Methold claimed (see footnote 8) that, “if we drop our LOAEL down to 45 we can see that there will be a substantial increase in the number of reported effects compared to the environmental statement”; he put this increase “in the region of two and a half times” (from 1,424 total adverse noise effects to 3,380). However, one thing that Mr Methold did not make clear to the Committee was whether his analysis of adverse noise effects took account of the impact of also having a night LOAEL of 60dB LpAFMax; I suspect possibly not. With three possible LOAEL trigger points in force (LAeq,day, LAeq,night and LAMax) it is only the most stringent, i.e. the first threshold to be crossed, that has effect. With the current set of values for LOAEL, this trigger value would appear to be, in most if not all cases, LAMax, and it is far from clear whether lowering the LAeq,day LOAEL threshold to 45dB would change this.

Also, it is rather an academic discussion in one other very important respect. The second aim of the Noise Policy Statement for England (NPSE) only requires that “all reasonable steps” should be taken to “mitigate and minimise adverse effects” from noise at locations above LOAEL (and below SOAEL). However, the NPSE specifically acknowledges that “this does not mean that such adverse effects cannot occur” and this was conceded by Mr Methold (see footnote 9). It all comes down to the Promoter’s interpretation of what is “reasonable” in the way of mitigation.

That the Promoter does not think that he needs to do very much to be “reasonable” is, perhaps, signalled by Information Paper E20, which sets the policy that will be adopted for HS2, rather than the NPSE. This policy requires that the nominated undertaker should, when determining what is reasonable, “take account of the set of shared UK principles that underpin the Government’s sustainable development strategy”. This implies that the cost of providing mitigation will always be the controlling factor. The strength of the commitment in E20 to mitigate so that LOAEL is not exceeded is very weak; the nominated undertaker is only required to “take all reasonable steps” to guard against LOAEL being exceeded, and where this cannot be reasonably achieved, to reduce noise “as far as is reasonably practical”. There is also a very nebulous requirement for the nominated undertaker to “contribute to the improvement of health and quality of life through the control of airborne noise” (see footnote 10).

So lowering the daytime LOAEL threshold, as Mr Methold was proposing, might result in the overall assessment of the noise impact of HS2 being greater – which might, in turn, have implications for the politics of HS2 – but only a change in mitigation policy on the Promoter’s part can bring relief to any residents living along the route of HS2.

(To be continued …)

Footnotes:

  1. See paragraph 12 of the transcript of the afternoon session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015.
  2. The error is recorded in paragraph 12 of transcript of the afternoon session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015, but Mr Thornely-Taylor gets it right in paragraph 16. The correction by Mr Lewis and Sir Peter is recorded in paragraphs 93 to 97 of the same transcript. See also Table 1 in Appendix B of the HS2 Ltd document High Speed Two Information Paper E20.
  3. For example, Steve Summers, witness for Halton Parish Council et al, and Cllr Andrew Burrow for the Berkswell Society. For Mr Summers’ evidence refer to exhibit A1212(12) and paragraph 177 in the transcript of the afternoon session of the HS2 Select Committee that was held on Tuesday 14thJuly 2015. For Cllr Burrow’s evidence refer to exhibit A556(47) and paragraph 120 in the transcript of the morning session of the HS2 Select Committee that was held on Wednesday 10th December 2014.
  4. See paragraph 16 of the transcript of the afternoon session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015.
  5. See paragraph 22 of the transcript of the afternoon session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015.
  6. See paragraph 27 of the transcript of the afternoon session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015. I have corrected the text in the record from the video.
  7. Mr Hendrick’s comment is recorded in paragraph 111 of the transcript of the morning session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015.
  8. See paragraph 402 of the transcript of the morning session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015.
  9. See paragraph 2.24 of Noise Policy Statement for England (NPSE), Defra, March 2010.
  10. See paragraphs 3.1, 3.2, 3.4 and 4.1 of High Speed Two Information Paper E20.

Acknowledgements:

I wish to thank Michael Woodhouse for his suggestions and comments, which I have found invaluable in preparing this series of blogs.

Exhibit A1571(71) has been extracted from the bundle of evidence submitted to the HS2 Select Committee by Rick Methold and published on the website of the HS2 Select Committee. Exhibit A1212(12) has been extracted from the bundle of evidence submitted to the HS2 Select Committee by Halton Parish Council and others, similarly published. Exhibit A556(47) has been extracted from the bundle of evidence submitted to the HS2 Select Committee by the Berkswell Society, similarly published.

Important Note: The record of the proceedings of the HS2 Select Committee from which the quote reproduced in this blog has been taken includes uncorrected transcripts of evidence, which are not yet an approved formal record. Neither witnesses nor Members have had the opportunity to correct the record in such instances, and it may therefore be subject to changes being made in the light of any such corrections being requested.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: