IPC Submission - Brig-y-Cwm - UVAG - Atmospheric Modelling
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1 IPC WRITTEN SUBMISSION
1.1 Submission Subject:
Proposal for an Incinerator/EfW Facility at Brig-y-Cwm, Cwmbargoed,
Merthyr Tydfil
(IPC Ref No: EN010004)
1.2 Submission Topic:
Unique Topography and Atmospheric Conditions at the proposed Brig-y-Cwm site
and the inadequacies of the applicants Atmospheric Modelling
1.3 Submitted by:
United Valleys Action Group (UVAG)
1.4 Contact Address:
Chris Austin - UVAG Secretary
10, Llwyn-yr-Eos Grove,
Bradley Gardens,
Incline Top,
MERTHYR TYDFIL.
CF47 0GD
1.5 Contact E-Mail Address:
postmaster@caustin7.plus.com
1.6 Contact Telephone Number:
01685 723737
(Landline number with answer-phone facility)
1.7 Submitter IPC Reference:
UVAG
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2 Introduction
This is a group submission by the United Valleys Action Group (UVAG), on behalf
of the residents of the Heads of the Valleys area. This submission explores the
issues we have with the proposed incinerator/Energy from Waste (EfW) facility at
Brig-y-Cwm.
This submission looks specifically at the Unique Topography and Atmospheric
Conditions extant in the area around the proposed Brig-y-Cwm site and explores
the perceived inadequacies of the applicant’s Atmospheric Modelling exercise.
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3 Contents
1
IPC WRITTEN SUBMISSION .......................................................................................................... 1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
SUBMISSION SUBJECT: .................................................................................................................. 1
SUBMISSION TOPIC:....................................................................................................................... 1
SUBMITTED BY: ............................................................................................................................. 1
CONTACT ADDRESS: ..................................................................................................................... 1
CONTACT E-MAIL ADDRESS: ........................................................................................................ 1
CONTACT TELEPHONE NUMBER:................................................................................................... 1
SUBMITTER IPC REFERENCE: ........................................................................................................ 1
2
INTRODUCTION ................................................................................................................................ 2
3
CONTENTS.......................................................................................................................................... 3
4
APPLICATION OVERVIEW ............................................................................................................ 4
5
SUBMISSION ...................................................................................................................................... 4
5.1
UNIQUE TOPOGRAPHY AND ATMOSPHERIC CONDITIONS AT THE PROPOSED BRIG-Y-CWM SITE
AND THE PERCEIVED INADEQUACIES OF THE APPLICANTS ATMOSPHERIC MODELLING................................ 4
5.1.1
Introduction ............................................................................................................................. 4
5.1.2
Submission Detail .................................................................................................................... 6
5.1.3
Submission Conclusion ............................................................................................................ 9
5.2
NOTES: ........................................................................................................................................ 10
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4 Application Overview
The proposed incinerator is to be sited in an area of multiple deprivation. The
Heads of the Valleys area has suffered badly over the years at the hands of short
sited projects which have brought far more problems than solutions.
In Merthyr Tydfil alone we have suffered a steady decline through the loss of
originally, its heavy industry and then its manufacturing industry. This has left the
town with the legacy of high unemployment, high sickness rates, chronic illness,
and low educational standards, to name but a few. Schemes such as the Biffa
landfill site at Trecatti and the Miller-Argents opencast coalmine at Ffos-y-Fran
have introduced problems for the town ad its residents, but have done little to
ameliorate the unemployment and health problems. I believe that the proposed
incinerator is very much in the mould of its predecessor and will introduce many
more problems than it will solve.
Although the site, and hence the planning application is in the Merthyr Tydfil
County Borough, the impacts will be felt across the Heads of the Valleys (HoV)
area.
The prevailing wind direction from the South West will ensure that any emissions
from the plant (including noise) will be directed towards the Rhymney and
Sirhowy Valleys for the majority of the time (60-70% of the time).
5 Submission
5.1 Unique Topography and Atmospheric Conditions at the
proposed Brig-y-Cwm site and the perceived inadequacies
of the applicants Atmospheric Modelling
5.1.1 Introduction
The members of the United Valleys Action Group (UVAG) are all resident in what
would be the affected area of the proposed plant and have first hand knowledge
of the atmospheric conditions that prevail around the proposed site for this
incinerator.
Although none of us are trained meteorologists we consider that our combined
local knowledge gives us a unique perspective on how the emissions from the
plant will behave under the atmospheric conditions imposed by the topography of
the heads of the valleys area.
We believe that Covanta’s modelling of the distribution and dispersion of the
exhaust plume from the proposed plant is flawed and does not represent the
atmospheric conditions that prevail at the location.
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Our comments come from actual observations of the local weather patterns and
their frequency and we will approach this submission from a practical perspective
With the plants proposed position on a high plateau at the termination of 4
valleys, and with the suggested stack height of 384 feet, we can see several
problems that could occur. In essence, they fall under the following categories:

The area suffers from frequent temperature inversions exacerbated by the
steep mountain- sides and deep valleys.

Very low winter temperatures will sap energy from the rising plume.

There would be significant impact from ‘blocking’ high pressure events.

The topography causes swirling winds which can blow from various
directions even when there is a prevailing wind.

With a plateau height of 1200 feet above sea level and a stack height of a
further 384 feet, the stack would often be above the cloud-base when it’s
at 1500 feet or below
In our view the above conditions will cause the plume to remain within the local
area longer than is acceptable. I also believe that the plume will come to ground
within the locale, much earlier than projected - i.e. the emissions will not get the
opportunity to disperse successfully to the degree indicated, and required.
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5.1.2 Submission Detail
Inversions:
Anticyclonic/high pressure weather conditions in this area cause dense mists and
fog, especially in the cooler months. This could rapidly bring the plume to ground
and hold it in the local area for an extended period.
These temperature inversions occur when nocturnal terrestrial heat radiation
cools the earth and the surrounding air. In the hilly topography that we have at the
proposed site, the heavier cold air would run down into the valleys displacing the
lighter warm air. This leads to the inverse of the normal scenario where the
temperature decreases as we gain height.
The boundary layer between the cold and warm air is termed an ‘inversion lid’
which has the ability to trap polluted air beneath it for the duration of the effect.
With the smoke-stack height being lower than some of the mountains we could
see the falling air pulling the rising plume down and trapping it below the inversion
lid/boundary layer.
During the winter months this phenomenon could be exacerbated by the colder
air temperature sapping the energy from the rising plume. This coupled with the
heavy and falling cold air the plume could descend into the valley and be
contained there by the inversion lid.
We see this event quite frequently here and standing on the hills looking down
onto the strato-cumulus clouds formed by the inversion is joyous, but
unfortunately it is also a harbinger of what problems may come if this incinerator
is approved.
Dense fog caused by this event is a common occurrence on the Merthyr and
Gelligaer Commons. This is a good illustration of the frequency of these
conditions in the immediate area around the proposed incinerator.
The area suffers from very cold winter temperatures in the Heads of the Valleys
area when we have cold anticyclonic/high-pressure conditions, especially up on
the high commons. Last winter we were recording -12 to -15 degrees Centigrade
in this area, and I believe -17 degrees Centigrade has been recorded up at Cwm
Blacks, Cwmbargoed. This would significantly rob the plume of its energy, and it
may then fail to achieve the height it needs to clear the locale and disperse. This
could very well bring the plume down early, and depending on the weather
conditions, may again trap the emissions below a boundary layer right in the heart
of the community.
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High pressure systems are frequently associated with low winds at the surface.
The blocking and capping effect of the high pressure, and atmospheric
subsidence (falling air) through the lower layer of the troposphere (lower
atmosphere), will ensure that pollution stack emissions will remain near to their
source.
Emissions from the plant will have no mechanism to clear the area and will
remain trapped near to the ground in the locale for the duration of the
atmospheric event. This can be for days, or even weeks.
We believe that this could become a significant problem here during the summer
months with the incinerator emissions lingering around the communities for
extended periods.
This effect was nicely illustrated recently when we had many grass fires in the
area during such high pressure weather conditions. The smoke hung around at
ground level for weeks. The visibility was so poor that it got down to 100s of
Metres at its worst. Under these conditions the local residents would be breathing
the incinerator emissions for what could be weeks, with the pollution content
density increasing day-by-day.
The circular winds that we often see on Merthyr and Gelligaer Common are, as
we understand it, contained to the lower levels, but may be at enough of a height
that could drag the pollution down and around the area.
An historic event that illustrates the impact of these conditions is the Great Smog
of London in December 1952 which was responsible for 4,000 deaths within 6
days and 8,000 more over the following months. An extreme example, I know but
it does illustrate that under these weather conditions the plume will have nowhere
to go.
With the height of the plant above sea level and the stack height, the stack would
often be higher than the cloud-base and hence within the clouds. When these
clouds are full of moisture we suspect that the NOx content and the Sulphurous
content will mix with the water vapour and make dilute Nitrogen and Sulphuric
acids. With the particulates mixing with the clouds and giving the water something
to bind to, it could cause the water and acids to fall in the immediate vicinity of the
plant. This would also bring down the rest of the emissions with it into the heart of
the surrounding community with no chance of it dispersing before it came down.
We have observed on many occasions that at the end of an anticyclonic/high
pressure event in Merthyr Tydfil there is usually a fall of rain. This rain initially falls
black! This appears to be an indicator that the coal dust from the Ffos-y-Fran
opencast mining operation has been hanging in the atmosphere for the period of
the capping high and drops out with the first rainfall. We submit that this will also
be the fate of the smokestack emissions; trapped in the atmosphere in the locale
and grounding over time and also with the first rainfall. For that period the local
communities will be breathing in the pollution with an uncertain impact on their
health.
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We also question the validity of the meteorological data used. There hasn’t been
a Met Office approved weather station here since 1986 as far as I know, most
certainly not for the period 2004 to 2008 which is the period that has been used
as input criteria to the atmospheric model.
Researching the Covanta permit application to the environment Agency I found
that in Appendix D of the report, ‘Air Quality Report’, the following statement
offers an explanation:
4.34 The closest meteorological station to the proposed site is Cardiff Weather
Centre which is 31km south of the proposed EfW site. This a coastal site and
records weather conditions at an elevation of 52 mAOD. As such this site is not
suitable for the air dispersion modelling as the application site is located
inland at the head of a valley at a height of 375 mAOD.
4.35 The closest inland site at an appropriate elevation is Sennybridge (307
mAOD [metres above ordinance datum - chrisa]), however, this is approximately
40 km away and located in hilly terrain, in comparison to the valleys that
predominate in the application site area. As such Numerical Weather Prediction
(NWP) data have been generated by the meteorological office. This is computer
modelled meteorological data set based on observed meteorological conditions at
the closest monitoring sites and adjusted to take account of local conditions.
As such it has been deemed the most appropriate data for the dispersion
modelling. NWP data was generated for 2004 through to 2008. Wind-roses have
been constructed for each year of the NWP data used in this assessment and are
presented in Figure C.1
From this I realised that the weather data has also been ‘modelled’ using data
from two sites, Cardiff and Sennybridge, neither of which are truly representative
of the region in which the proposed incinerator is to be sited. In the absence of
empirical data, it was constructed using a computer weather model.
The atmospheric dispersion model needs good local meteorological data to make
it more representative of the site, but in this case it is absent and has had to be
fabricated. This only adds more variance to the results and subsequent
conclusions.
We have spoken with a representative from the Air Dispersion Modelling team
working with the Environment Agency Wales and he said that very small changes
to the input criteria used to drive the model can have significant impact on the
results, and hence the conclusions drawn from the modelling exercise.
The variations in the weather model and any inconsistencies or inadequacies in
the topographic modelling of the proposed site could easily produce results that
aren’t representative of the actual atmospheric conditions prevailing in the area.
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Covanta (via RPS) say:
4.102 With respect (ii) to (v), a range of realistic input parameters has been
considered and the option predicting the most conservative outcome has been
included within the model. On this basis, the results of the assessment should
be considered a worst-case scenario.
We are confused as to how they can make this statement when the weather data
has been fabricated, how could they state that they elected to represent the worst
case scenario?
More representative meteorological data is available, even though it would be
historic, from the original weather station at Cwmbargoed which operated from
1969-1986. This data would most probably be available from the Met Office.
The consequence of this is that if no representative data is available and the
accuracy of the model depends on it then Covanta would have to make a detailed
meteorological study of the proposed site and surrounding area to ensure that
their results truly represent the local atmospheric conditions.
5.1.3 Submission Conclusion
The atmospheric model may be an industry standard, but its accuracy is
determined by precise adjustment to the input parameters to truthfully represent
the actual topography and atmospheric conditions. With the rather unique
topography we find around the proposed site, the results and the conclusions
drawn from them would depend highly on the accuracy of this modelling and this
needs to be verified by experts in the field using more representative weather
data.
Slight changes to the input parameters could result in large variances in the
results and hence the conclusions as to the behaviour of the smoke-stack
emissions plume.
Accurate weather data needs to be used to ensure that the model is
representative, but we find that in this study that even this meteorological data
has been fabricated.
We have grave doubts about the accuracy of Covanta’s atmospheric model, and
we believe that, in reality, we could find ourselves in the far more unacceptable
scenario of the plume being trapped in the locale, with no chance for the
pollutants to disperse, and with all the attendant human health concerns being
realised.
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APPENDIX A
5.2 Notes:
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