Dovenby Village

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All content are opinions and objections that were raised as part of the response to Msport planning application to Allerdale planning ref 2/2014/0350.  If you have any comment or disagreement then first realise that opinion is just that, opinion in a public planning process.  You may email factual errors to Contact @ dovenbynoise.info

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Comments on Noise Management Plan by Mike Stigwood Noise Consultant MAS Environmental


Mr Stigwood is accepted as an expert witness at High Court and gave noise evidence in various cases, notably Coventry v Lawrence that was eventually considered and won in The Supreme Court with huge legal costs.  Please consider his comments very carefully.  

TECHNICAL POINT ABOUT NOISE PLAN


The application is juggling with numbers to give the appearance of controls over short term noisier periods but in fact are allowing the same noise as controlled by the hourly limit.  


In effect this renders the short term controls a "white elephant" and it is an attempt to circumvent their intended control.  This is an abuse of the science of acoustics of the worst kind and contrary to what the court must have thought was going to be achieved.  This is the case both in relation to the LAmax and 5 minute LAeq.  Put it this way, the value proposed for 5 minutes would only be triggered when the hourly value is exceeded in any event due solely to very high noise in the 5 minute period. i.e. compress all the hourly noise into 5 minutes and you get just slightly less than the 5 minute value proposed.  


This renders the LAmax and 5 minute LAeq superfluous and undermines the solution agreed at court.


So if you exceeded 66dB LAeq(5 min) then you would exceed 55dB LAeq(1 hour) in any event, even if the remaining 55 minutes were silent.  The calculation is as follows

1)  Divide 66dB by 10 to give a value in Bels rather than decibels = 6.6.  2) Antilog 6.6 to give a pressure value.  3) Divide the value by 12 to average it over an hour rather than 5 minutes (5 mins /60 mins).  4) Log the resulting number and multply by ten to get a decibel value = 55.2dB LAeq(1 hour).  Thus 66dB LAeq (5 mins) = 55.2dB LAeq (1 hour).   


This is wholly contrary to the intent of a short term control.   The intent is to prevent the operator using the averaging over an hour to permit a short period of very high intrusive noise typically from a short duration event.  It follows as a matter of logic and in accordance with the principles that the short term control aims to prevent all this sound energy being emitted in a short term period and as a result the short term controls must logically prevent all the noise energy being emitted in any one 5 minute period.  In fact the intent is to prevent any short period being highly intrusive.  Of necessity it requires to be a lower total energy dose than the hour value.  I will come back to you on what levels are appropriate.


To place this all in perspective in the case of Coventry v Lawrence [A planning authority by the grant of planning permission cannot authorise the commission of a nuisance.], [Supreme Court Ruling] a maximum of 55dBA over any 15 minute period was permitted over any 15 minute period in order to prevent nuisance with a limit of 45dB LAeq on other days.  This site is permitted 45 days of an hourly value of 55dBA which if compressed into 15 minutes would equate to 60dBA as the maximum in any 5 minute period.  Put another way, this Dovenby site is seeking 6dB higher intrusive noise in any 5 minute period over 45 days than was held a nuisance in the Coventry v Lawrence case which was only permitted for 24 days.  Remaining days were limited to 45dB LAeq(15 minutes) = 50dBA for any 5 minute period.            


Any argument this noise is less intrusive as it is not motorsport will be determined in due course but high speed, acceleration and deceleration, tyre screech and similar characteristics may be expected rendering it close to motorsport type impact.


The LAmax analysis is also juggling with numbers and misleading.  Higher LAmax sounds occurring now in the community provides no justification for this noise to be high in level and there is no basis for 15dB above the levels permitted i.e. 43dB, 50dB and 55dB.  Even at 55dB it only gives a level of 70dB LAmax and not 76dB.  Further the argument for 15dB as a differential applied by the WHO at night is wholly erroneous as that was in the 1999 guidelines and in 2009 the criteria was changed from 60dB (facade level and not free field) that was mere sleep disturbance to a facade level of 57dB that equated to the level causing awakenings.  At worst the differential was reduced in 2009 to 12dB and at best a differential of less than 10dB is required to avoid awakenings.  


Thus following the criteria argued by the developer in their March 2016 document that the WHO had a differential between LAmax and LAeq and this can be applied, based on the most up to date criteria it gives a value of not more than 10dB difference which places the LAmax at not more than 65dB for those days where the hourly value is 55dBA and 53dBA for days when noise is limited to 43dB LAeq.  


An interesting comparison can be drawn with Donnington Park track days which were considered to cause nuisance and an Abatement Notice was served.  Control was set at 98dB LAmax trackside which was based on a 47dBA reduction to the village of Castle Donnington = 51dB LAmax.  I believe somewhere there was a further 4dB reduction giving 47dB LAmax as a community level.  This Donnington Park activity is directly comparable to Dovenby and equates reasonably closely to the 53dB value above.  It was derived from a detailed study by someone undertaking their PhD under the supervision of Dr Mike Fillery an acoustics specialist at Derby Uni.  Dr Fillery had a specialist interest in motorsport.  It is also instructive that Dr Fillery advised Palmer Promo Thurleigh where a site boundary LAmax limit close tot he track of 65dB LAmax was set which at the nearest dwelling was similarly in the low 50s or high 40s dB Lamax.  


WHAT NOISE NEEDS CONTROLLED IN THE NMP?


1)  The WHO in their advice to local authorities 2000 make the point "the decibel level accounts for only one third of noise annoyance".  Two thirds relate to non-acoustic factors including the character of the noise.  The High Court has acknowledged this point, upheld in the CoA.  Bontoft Taylor and Others v East Lindsey DC.


2)  The High Court has confirmed noise can be a nuisance even when not measurable as a decibel value, where it is incongruous and out of character in the area where it occurs.  Godfrey v Conwy CBC 2001.   This places the limited value of the decibel into context.  


3)  Recent Defra research clarifies that whilst different levels of transport noise will cause significant adverse effects at a range of levels with aircraft worst followed by road traffic and then rail traffic, other sources of noise including neighbour and neighbourhood noise require individual qualitative and quantitative assessment and no set decibel levels can be applied as it relate to context.  More on this later but in summary any noise which is site related as here and contains special characteristics will intrude dependent on those characteristics and how loud.


4)  Loudness will depend on the level of background masking noise present and how similar or different that asking noise is.  Generally to intrude sound have to emerge above the background sound levels but how much depends on the spectrum content.  Thus if you live with natural sounds such as leaves rustling and birds tweeting then the low frequency throb and pulsations of some vehicle engines can be audible even when its decibel level is lower that the decibel level for the natural sounds i.e. quieter than the background sound levels.  We can typically hear music bass beat up to 10-15dBA below background sound levels.   Thus impact can relate to audibility.  For fairly innocuous noise it is more about how loud and dominating the noise is as to whether it impacts.  This is what the WHO guidelines are directed at, noise which imparts no special message of alarm or alert to an inadvertent listener.  


5)  Before considering decibel levels we need to consider a range of non-acoustic factors including the message a sound imparts.  For example you could have two equal sounds in terms of decibel level, one a child having fun or dog yapping in a friendly manner and so promoting happy connotations and imparting a message all is well.  Conversely you could have a child wailing or dog howling in pain, producing the same decibel level as the first case but imparting a message of alarm or concern.  Thus the same average decibel level but completely different impact.  There are so many examples, alarms evoke alarm, one persons music is anothers annoyance.  Thus decibel level is only relevant when it is about being loud and degrading the environment.  


6)  Annoyance intrusiveness and impact relate to audibility (not masked), how dominant, noisy and the message imparted, whether listeners tend to ignore or tune in to and so sensitise to (natural human response) the noise.   These are the factors which impact acceptability in this case.         

         

7)  The primary issues will depend on how dominant, how distracting, loud, sensitising, noisy and the frequency and duration of intrusion.  It will also depend on the ability to escape the noise, whether outside or inside, how pervasive i is and how often it pervades.   


8)  3dBA increase / decrease is twice / half the energy but barely perceptibly louder or quieter.  I can demonstrate this with an example online.


9)  10dBA increase normally considered a doubling of loudness or 10dBA quieter is halving loudness.  


10)  20dBA  change is either a quadrupling or quarter the loudness, depending whether increasing or decreasing.  


11)  Recent major study by Health Canada on wind farm noise found people 18dBA less tolerant of it than road traffic noise.  I do not suggest this is the case for the Dovenby site noise but it is instructive that other environmental noise that could be considered continuous like traffic noise results in an entirely different level of response.