Download hs2aa-noise-slides-final

Witness Credentials
• Kieran James Gayler – Acoustic Consultant
• BSC (Hons) in Environmental Science
• Chartered Scientist, Chartered Environmentalist
• Member of the Institution of Environmental Sciences,
Institute of Environmental Management and Assessment
and Institute of Acoustics.
• Partner at Sharps Gayler LLP. Former Director of Sharps
Redmore Partnership Ltd. 20 Years in Acoustics
Summary of evidence
• The Promoter has understated and inadequately addressed
levels of noise above the night-time LAMAX LOAEL.
• The Promoter’s method for judging “reasonable
practicability” is flawed and leaves considerable risk with
residents, not the Promoter or the Nominated Undertaker.
• Failure to manage “Total Noise” has led to insufficient
mitigation of impacts, particularly in urban areas.
• The Promoter’s approach to quiet and relatively quiet areas
does not protect such areas.
Addressing night time LAMAX Levels
• The Promoter now acknowledges that the night-time LAMAX
LOAEL is the most far reaching of their tests for mitigation: the
“governing trigger”.
• The LAMAX LOAEL is defined at “façade level”, while all the
Environmental Statement (ES) figures for properties are shown
“free-field”
• Need to add 2.5dB to all ES figures to be comparable to the
60dB LAMAX LOAEL. The Promoter has adopted +2.5dB figure
as the “reasonable worst case”*
• The number of properties between LOAEL and SOAEL has been
substantially underestimated
*As in letter of 10 June 2016 from Simon Kirby to David Lidington, MP
Comparison of No. of Properties above LOAEL
Does the LAMAX LOAEL matter?
• The Promoter says LOAEL is not a health risk threshold, and
health effects do not occur until SOAEL
• Evidence quoted by WHO suggests the opposite
• Levels above the low observed effect levels are not a trivial
matter and must be mitigated and minimised
• Presumption that the Promoter is right, as opposed to
consensus of WHO experts, is problematic
Reasonable Practicability
• Information Paper E20: – reduce noise above LOAELs “as far as reasonably
practicable”
• All noise mitigation commitments are subject to this qualification
• No basis for calculating what is ‘reasonably practicable’ beyond WebTAG
• WebTAG gives values (£/household) to reducing noise using DEFRA health
based tables.
• DEFRA advise (1) simplified WebTAG tables or (2) a bespoke review. HS2
circumstances justify a bespoke approach
Problems with WebTAG
• No category for high-speed rail noise
• No appropriate consideration of LAMAX
• No value attributed to reductions of levels below 45 dB LAeq, day
or night
• Negligible sums for mitigation and a decrease in value (per
decibel reduction) as sound levels reduce.
• Compounded by underestimation of properties above LOAEL
Consequence of Promoter’s
“reasonable practicability”
• Risk for residents of increased noise.
• Examples:
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Noisier trains used on cheaper cost grounds
Reductions where slab track used being avoided on cost grounds
Limits of deviation being exploited to reduce cost
Mitigation being removed to reduce cost
Tunnel boom not being resolved on cost grounds
ES noise levels exceeded but actions triggered by F4 investigation too
expensive
• The “reasonable practicability” clause gives licence to The
Promoter/Nominated Undertaker to make more noise than
the ES specifies, simply on cost-benefit grounds, with the
values attributed to noise flawed and too small.
Total Noise
• WHO Guidelines used to derive LOAELs and SOAELs are
based on ‘total noise’
• HS2 is, however, considered in isolation of other sources for
LOAELs and SOAELs, making them less demanding
• Evidence that sources combine to have an additive effect
(sleep disturbance) ignored by the Promoter
• Combining HS2 with existing environment will bring about a
need for increased mitigation, especially in urban areas
Quiet Areas
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High speed rail – pronounced character
Low existing noise levels means the impact is enhanced
NPSE, NPS and WHO all refer to protection of quiet areas
The Promoter’s definition excludes most rural areas from
the noise assessment and treats them under landscape.
• The ES only considers impacts above 40 dB Leq (night) and
50 dB leq (day), irrespective of the change in noise level that
can be large in quiet areas.
• The Promoter has accepted that his policy is not directed at
preserving relatively quiet areas where new noise would be
a material addition, but in ensuring that the resultant noise
level is ‘acceptable’
Recommendations
LAMAX
• Additional Mitigation (including slowing trains at night) to
minimise properties above LAMAX LOAEL
• Update the ES and all future versions to show LAMAX
figures at the façade* enabling the correct comparison with
the LAMAX LOAEL;
• Explanation from the Promoter where mitigation measures
are rejected
* (+2.5db as “reasonable worst case assumption”)
Recommendations
Reasonable Practicability
• Disallow use of simplified WebTAG values for HS2 (for E20)
• Remove the clause for slab track, tunnel boom, HS2 train
acoustic performance, limits of deviation, exceeding ES
predicted noise levels, and from the F4 process
• Explanation from the Promoter where mitigation measures
are rejected
Recommendations
Total Noise
• LOAELs and SOAELs should be based on total noise (but be
the same values), with mitigation re-assessed
Quiet Areas
• Lower LOAELs and SOAELs for quiet areas
Methodology
• Review methodologies when 2016 WHO document is
released.