High Pressure Natural Gas PipelinePembroke Refinery
Environmental StatementNon-technical Summary
July 2010
Environmental Statement Non-Technical Summary
High Pressure Natural Gas Pipeline, Chevron Ltd NTS-1
1. Introduction
1.1 Overview
1. Chevron Limited (Ltd) is seeking detailed planning
permission for the development of a high pressure
natural gas pipeline connecting the Pembroke
Refinery to the South Haven Gas Pipeline (SHGP)
(currently under construction).
2. The Pembroke Refinery is situated adjacent to the
Milford Haven Natural Harbour, approximately 4
kilometres (km) west of Pembroke Dock, and on the
edge of the Pembrokeshire Coast National Park.
The SHGP is situated approximately 1.5km to the
east of the Refinery.
3. Figure 1 shows the planning application boundary
in the context of the wider area and the operational
fenceline of the Pembroke Refinery. The application
site, which comprises the proposed pipeline, a
construction compound, pipe lay down and soil
storage areas, and the tie-in point to the SHGP,
comprises a total of 19.3 hectares (ha).
1.2 The Need for the Development
1. The Pembroke Refinery is regulated under the
Environmental Permitting Regulations 2007 (as
amended), for processing crude oil into a range of
product fuels and feedstocks.
2. The refinery’s Environmental Permit (Reference
QP3033LW) sets out site-specific control
measures, limits and Improvement Conditions
relating to processes on site. Through this process,
Chevron Ltd is currently implementing various
improvements across the installation to reduce the
refinery’s emissions of sulphur dioxide (SO2) to the
proposed limit of 6,800 tonnes per year by 2011
and 4,300 tonnes per year by 2016.
Figure 1: Site Location Plan
Based upon an Ordnance Survey map with the permission of the Controller of Her Majesty's Stationery Office. Crown Copyright reserved License No. AL
100017812; 100020449
Environmental Statement Non-Technical Summary
High Pressure Natural Gas Pipeline, Chevron Ltd NTS-2
3. The proposed pipeline will assist Chevron Ltd with
achieving the SO2 target by supplementing heavy
fuel oil used onsite with natural gas. It will also lead
to a reduction in other atmospheric emissions such
as oxides of nitrogen, particulates, and greenhouse
gas emissions.
1.3 The EIA Process
1. URS Corporation Ltd (URS) was commissioned by
Chevron Ltd to undertake an Environmental Impact
Assessment (EIA) in accordance with the Town and
Country Planning (Environmental Impact
Assessment) (England and Wales) Regulations
1999 (as amended) and the Town and Country
Planning EIA (Wales) Regulations 2008. The
results of this process are presented in the
Environmental Statement (ES) and accompanying
technical appendices.
2. This document, known as the ES Non-Technical
Summary (NTS), provides an overview of the
findings of the EIA. It has been prepared for a
general audience including parties potentially
affected by the proposed pipeline development.
3. The ES has considered the potential impact of the
proposed pipeline on its neighbours, the local
environment, the local and regional economy, and
the wider area surrounding that in which the
pipeline is proposed. Beneficial and adverse, short
and long-term impacts have been considered.
Mitigation measures to either eliminate or reduce
adverse impacts have been incorporated into the
project design.
4. The ES has highlighted remaining, or ‘residual’
impacts, which remain following the incorporation of
identified mitigation measures. The significance of
residual impacts has been evaluated with reference
to definitive standards, accepted criteria and
legislation where available. Impacts have been
classified as being adverse, negligible or beneficial
in significance and either minor, moderate or major
in magnitude.
1.4 Scoping and Consultation
1. The EIA has included a programme of ongoing
consultation, which is critical to the development of
a balanced and comprehensive ES. Views of
statutory and non-statutory consultees serve to
focus the studies and identify those issues that
require further investigation. Consultation also
enables mitigation measures to be introduced
during the project design process.
2. Key consultees through the EIA process included:
• Pembrokeshire County Council (PCC);
• Environment Agency Wales (EAW);
• Countryside Council for Wales (CCW);
• Pembrokeshire Coast National Park Authority;
• Dyfed Archaeological Trust;
• Cadw; and
• The Health and Safety Executive (HSE).
2. Alternatives and Design Evolution
1. The EIA has considered the ‘No Development’
option, the use of ‘Alternative Sites’, and a number
of ‘Alternative Designs’.
2. The ‘No Development’ option refers to leaving the
site in its current state. This is not considered a
viable option since the continuation of current
operations would result in Chevron Ltd being in
breach of its environmental permit.
3. Having determined that piping the natural gas fuel
to the Pembroke Refinery would significantly
reduce SO2 emissions, Chevron Ltd considered
alternative routes for the pipeline. This included
making a new connection directly to the South
Wales Pipeline, which lies to the north of Milford
Haven waterway, though this was later rejected on
the grounds of environmental impacts and
significantly higher construction costs associated
with drilling and installing the pipeline under the
Milford Haven.
4. The possibility of upgrading one or more existing
pipes that run between the refinery and other
installations in the area was also considered.
However this option was found to be not viable due
to the significant works required to make these
pipes suitable for transporting gas, and the
significant environmental damage that would have
resulted from intrusive investigations needed to
confirm the position of these pipes.
5. The construction of the SHGP, as an associated
key component of the new RWE npower Pembroke
Power Station (approximately 1.5km east of
Pembroke Refinery), provided an opportunity to
bring natural gas to the Refinery via a relatively
short length of new pipeline.
6. It was decided that the optimal design for the new
pipeline would be to lay the pipe predominantly
underground, only coming above grade once it was
within the Refinery fenceline. This option was
chosen in order to minimise visual intrusion, reduce
the chance of accidental or deliberate damage to
the pipeline, and allow the agricultural fields it
Environmental Statement Non-Technical Summary
High Pressure Natural Gas Pipeline, Chevron Ltd NTS-3
crossed to continue to be used in the current
manner.
3. The Proposed Development
1. The proposed pipeline will provide a natural gas
supply between the Pembroke Refinery and the
SHGP, which is currently under construction and
forms a part of the Pembroke Power Station project
(which is also currently under construction).
2. The proposed pipeline route and associated
infrastructure is presented in Figure 2. Figures 4
and 5 present photographic views across the
application site to the north and northwest
respectively.
4. The proposed development will be predominantly
underground (entirely so outside the fence line of
the Refinery to where it connects with the SHGP)
and will pass through a largely agricultural
landscape, south of the Milford Haven Waterway
Site of Special Scientific Interest (SSSI) and
Special Area of Conservation (SAC). The proposed
pipeline route also passes immediately to the south
of the Pwllchrocan Environmental Centre (formerly
St Mary's Church) and crosses the Pembrokeshire
Coast Path near the easternmost extent of the
pipeline.
5. The proposed development will comprise the
following features:
• 2.17km in length, of which approximately
1.25km is within the fenceline of the Refinery;
• 790m of above ground pipeline within the
Refinery fenceline, a further 460m below ground
within the Refinery fenceline, and 925m below
ground outside of the Refinery fenceline;
• 300mm (approximately 12 inches) diameter,
and suitable for transportation of gas at
Figure 2: Proposed Pipeline Route and Associated Infrastructure
Environmental Statement Non-Technical Summary
High Pressure Natural Gas Pipeline, Chevron Ltd NTS-4
approximately ambient temperature (about 5ºC).
The temperature will be raised to 38ºC by the
pre-heater;
• A maximum height of 2.5m above ground level
(agl) for the above ground structures and over
ground pipeline sections, either in the Refinery
or Power Station sites; and
• A depth to base of the pipe of approximately
1.5m (i.e. 1.2m of ground cover on top of the
300mm diameter pipe) along the majority of the
route between the SHGP and the “pig” catcher
(the receiver for a devise used to remove
deposits in the pipeline and collect information
such as metal loss / corrosion and temperature /
pressure). The buried depth will vary with local
features, increasing to a depth to base of the
pipe of 2.0m (i.e. 1.7m cover) beneath
watercourses;
• A maximum of four 4” (102mm) diameter ducts
will be installed within the pipeline trench along
the length of the pipeline to relay information
from the instruments at the tie-in point to
Pembroke Refinery. Once above grade the
instrument cabling will be carried within cable
ducts and cable trays within the refinery.
6. The pipeline will be designed and constructed in
accordance with prevailing guidance and Chevron
Ltd standards.
3.1 Pre-Construction Activities
1. A Construction and Environmental Management
Plan (CEMP) will be produced and implemented
prior to the onset of the construction phase to
maintain consideration of environmental impacts
beyond the planning stage of the proposed
development.
2. The key pre-construction stages of the project will
be as follows:
• Liaison with key local stakeholders;
• Completion of a pre-construction survey to:
- Accurately mark out the pipeline ‘Right
or Way’ (ROW) (or “construction
corridor”) and location of existing third
party services; and
- Provide a photographic record of the
entire route including key operational
and environmental features and
aspects.
• Completion of additional environmental surveys
if required by Pembrokeshire County Council or
other statutory consultees;
• Instigation of pre-construction environmental
mitigation measures, as necessary;
• Marking of all crossing points of buried services
and any environmental resources to be
protected;
• Establishment of temporary access tracks along
the construction working width; and
• Determination and implementation of the
appropriate security and health & safety
arrangements.
3.2 Construction Phase
1. The construction of the proposed pipeline is
envisaged in phases as follows (as illustrated in
Figure 3):
• ROW Preparation and Grading;
• Trench Excavation;
• Pipe Stringing and Bending;
• Lowering and Laying;
• Pipe Welding and Inspection;
• Field Coating;
• Pipe Tie-in;
• Backfilling;
• Hydrostatic Testing;
• Clean up; and
• Restoration.
2. The proposed pipeline’s ROW for construction will
be up to 30m in width, allowing for construction
vehicle access, and pipeline laying / stringing prior
to installation and burial. This will be reduced to15m
within sensitive areas, namely the reedbed and
wooded areas.
3. The trench (for the underground section of pipeline)
will be 0.6m wide and covered back over with 1.2m
of fill material, or 1.7m beneath the watercourses.
3.3 Above Ground Structures
1. The proposed pipeline development will include the
following above-ground structures:
• The tie-in point to the SHGP, which releases the
pig and includes an emergency shut down
valve); and
• The above ground section of pipeline, within the
Refinery fenceline. This also includes a let down
station (to reduce the gas pressure) and pre-
heater (to raise the temperature of the gas) near
the western end of the pipeline.
2. The locations of these features are shown in Figure
2.
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High Pressure Natural Gas Pipeline, Chevron Ltd NTS-5
3. The SHGP tie-in point will have a maximum
footprint of 45m by 32m and height of up to 2.5m,
as shown in Figure 4.
4. The pig catcher and let down station will be much
smaller in size, within the general footprint of the
proposed pipeline.
3.4 Temporary Construction Compound
1. It is estimated that there will be approximately 40
construction workers on-site during the peak of
construction activity, of which approximately eight
are managerial staff required on-site at all times.
2. A temporary construction compound will be
required during the duration of the construction
activities. The compound will be located on either of
the two fields east of the reedbed and wet
woodland (i.e. the field south of Pwllcrochan
Environmental Centre) or the field east of the road
to Pwllcrochan, as shown in Figure 2.
3. The compound will include an area for pipe storage,
temporary offices, vehicle parking for construction
workers and a maintenance area. The compound
will have a maximum footprint of 100m by 150m
and will be enclosed by security fencing.
Figure 3: Pipeline Construction Phases for Underground Section of Pipeline
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High Pressure Natural Gas Pipeline, Chevron Ltd NTS-6
3.5 Construction Programme
1. It is anticipated that the construction phase will
commence in the first quarter of 2011 and comprise
a total of approximately 18 weeks.
2. This includes 4 weeks to mobilise to site, set up the
construction compound and establish the fencing
prior to the main works beginning. Following this,
an estimated 3 weeks will be required to strip the
top soil prior to 3-4 weeks of pipe stringing and
welding. The actual excavation will take an
estimated 3 weeks, followed by 3 weeks of backfill,
1 week of pressure testing, and 3 weeks of
reinstatement.
3.6 Decommissioning of the Development
1. It is anticipated that the pipeline will be operational
for the lifetime of the Pembroke Refinery. At a time
when the pipeline is no longer considered an
operable asset for either technical or commercial
reasons (or the Refinery closes), the pipeline shall
be decommissioned.
2. The pipeline would be emptied, cleaned, sealed
and capped, with above ground pipe removed and
above ground installations cut to at least 900mm
below the ground surface. It is not envisaged that
the underground pipeline would be removed, as this
is anticipated to have the lesser environmental
impact.
Figure 4: Indicative Drawing of Above Ground Installations (AGI)
Environmental Statement Non-Technical Summary
High Pressure Natural Gas Pipeline, Chevron Ltd NTS-7
4. Planning Policy Context
1. The Proposed Development has been assessed
against relevant national, regional and local
planning policies. Planning policy has been
considered in each of the technical Chapters of the
ES as appropriate for the consideration of
environmental effects.
5. Environmental Impacts
5.1 Air Quality
1. An air quality modelling exercise was undertaken to
assess the impacts associated with emissions
generated by road traffic, exhaust emissions from
plant and machinery, and the potential for dust
generation during the construction phase of the
proposed pipeline development. The modelling
exercise also considered the indirect effects, which
will result from a change in fuel mix being
combusted on the Pembroke Refinery as a result of
the availability of a natural gas supply.
2. Impacts from road traffic emissions, site plant, and
construction dust during site preparation and
construction are predicted to be negligible. These
impacts will only be for a maximum of 4 months,
and a number of mitigation measures have been
recommended to further minimise any impacts,
which will be incorporated into the CEMP.
3. The modelling of the refinery emissions predicts
that pollutant concentrations will easily comply with
the air quality objectives across the site and
surrounding area.
4. Pollutant concentrations are predicted to improve in
the area as a result of the proposed development,
since the Heavy Fuel Oil currently used onsite will
be replaced by Refinery Fuel Gas. This is predicted
to result in lower (better) emissions of several
pollutants, including sulphur dioxide, oxides of
nitrogen and particulates.
5. There is predicted to be a minor beneficial impact at
the Milford Haven Waterway SSSI due to a
reduction in sulphur dioxide emissions from the
Refinery. A small improvement in pollutant
concentrations is also predicted at Greenhill Farm,
the nearest residential dwelling to the Refinery,
situated 430m south of the pipeline route or 220m
south of the nearest point of the application site
boundary.
5.2 Noise and Vibration
6. A baseline noise survey was conducted during the
period 7th December 2009 - 8th December 2009 in
accordance with best practice.
7. The noise environment in the western part of the
proposed pipeline route is dominated by the
Pembroke Refinery. The noise in the eastern part of
the application site was dominated by the
construction of the Pembroke Power Station. There
was also some noise contribution from the local
road network, of which some can be attributed to
the construction traffic associated with the
construction traffic movements to and from the
Pembroke Power Station Site.
8. The nearest sensitive receptor to the proposed
pipeline route is Greenhill Farm, as discussed
above. Given the absence of any piling works
during construction of the pipeline, and the
distances between Greenhill Farm and the
proposed locations of the above ground
installations, noise and vibration (both from
construction activities and traffic) will have a
negligible impact on this receptor.
9. Once built, it is expected that there will be little or
no operational noise from the proposed pipeline.
Any operational noise that does arise will be on the
Refinery or Power Station sites (associated with the
above ground installations, such as the emergency
shut down valve). Operational noise impacts have
been calculated to be negligible.
10. Since piling is not required during construction, and
there are not anticipated to be operational vibration
sources associated with the proposed pipeline,
there is not predicted to be a significant impact from
vibration.
11. With the exception of the occasional maintenance
vehicle, there will be no operational traffic
associated with the proposed pipeline.
12. The potential impacts associated with the
decommissioning phase are considered to be less
than those impacts associated with construction
and as such, are considered to be negligible.
13. It is not anticipated that there will be significant
impacts in terms of noise or vibration throughout all
phases of the proposed pipeline development.
Environmental Statement Non-Technical Summary
High Pressure Natural Gas Pipeline, Chevron Ltd NTS-8
5.3 Ecology
1. An ecological impact assessment (EcIA) has been
undertaken by establishing the current ecological
baseline conditions within the application site, and
subsequently assessing the significance of potential
impacts of the proposed pipeline upon these
conditions.
2. The assessment included a desk based review of
secondary data, an Extended Phase 1 Habitat
survey to record the nature and extent of vegetation
and habitats within and adjacent to the site, and
detailed surveys for flora and fauna including the
following:
• Bat (roost emergence and activity);
• Badger;
• Water vole and otter;
• Hazel Dormouse;
• Breeding birds; and
• Vegetation.
3. Following implementation of the mitigation
measures outlined within the ES, no significant
adverse residual effects are anticipated associated
with the proposed development. There will be no
permanent landtake in areas of substantive nature
conservation value and impacts on habitats will be
temporary during the construction period, with
restoration taking place after the pipeline
installation has been completed.
4. The only significant impact will be on woodland
habitat and will be at the lowest ‘Site’ level. With the
works anticipated to take place in the winter,
impacts on bats and nesting birds will be avoided
and potential impacts on other species can be
mitigated by the implementation of standard
measures.
5.4 Land Use and Agriculture
1. The agricultural area assessed in the ES is mostly
in pasture with one arable field. Some of the land
examined in the eastern side of the application site
was a former sports ground (later abandoned)
associated with the former RWE npower Power
Station. Although the land is not in active use either
for sports or agriculture, this area was included
within this study as being of potential agricultural
use.
2. The entire application site is encompassed by
either Chevron Ltd or RWE npower ownership, with
the agricultural fields rented to two farm holdings.
3. In view of the fact that the proposed development
involves reinstating the land to its former condition
following the laying of the pipeline, the largest
disruption to farming operations will occur during
the construction phase.
4. The entire duration of the impact on agricultural
pasture land in the construction phase is likely to be
a maximum of 4-5 months, between preparing
access and reinstatement of the construction
corridor upon completion. This is an impact of minor
adverse significance, which is temporary and will
become negligible once the vegetation is re-
established.
5. The duration of the construction phase for the
arable field is unlikely to have a direct impact upon
any established crop. There is a slight chance of
interference in drainage if any drainage channels
are interrupted. However, this is also considered
unlikely; therefore the proposed development could
potentially result in an impact of minor adverse
significance.
6. The potential impacts associated with the
decommissioning phase will be less than with
construction, due to the absence of trenching. It is
anticipated that minimal works would be required
within the agricultural farm holdings and therefore
the impact would be negligible.
7. Following implementation of mitigation measures,
the residual impact from the construction,
operational and decommissioning phases on land
use and agriculture is therefore considered to be
negligible.
5.5 Cultural Heritage and Archaeology
1. In order to inform the assessment of the
development of cultural heritage and archaeology,
an initial desk-based assessment was prepared,
identifying the potential for archaeological remains
to be present along the part of the proposed
pipeline route that has not been subject to previous
below ground disturbance.
2. In view of the potential identified and in consultation
with PCC’s Archaeological Advisor (Dyfed
Archaeological Trust), further field surveys were
undertaken within this area in January and
February 2010, comprising an archaeological
watching brief during geotechnical investigations
and a programme of invasive archaeological field
evaluation (trial trenching) in order to more fully
clarify the presence/absence, extent, character,
date and significance of archaeological remains.
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High Pressure Natural Gas Pipeline, Chevron Ltd NTS-9
3. There are no Scheduled Ancient Monuments
(SAMs) within the application site, although three
SAMs are present situated approximately 480m to
the north, 1.1km northwest and 900m to the
northeast of the application site respectively.
4. The application site lies within the Wales registered
outstanding historic landscape area of the Milford
Haven Waterway, which is identified as a
landscape of national importance in the Welsh
context.
5. Trial trench evaluation has recorded a series of
surviving Post Medieval features and deposits to be
present along the route of the proposed pipeline. All
the recorded features were shown to survive in a
poor state of preservation. On the basis of the
evaluation results, a low to moderate potential for
further surviving remains of this period was
identified along the pipeline route within the field to
the south of the Pwllcrochan Environmental Centre
and reedbed area. Beyond these areas, a low
potential for remains of this period was identified.
6. It is proposed that a programme of archaeological
monitoring and recording (watching brief) be
undertaken during site preparation and trenching
for the proposed pipeline development In order to
mitigate for the direct impacts of construction.
7. A short-term indirect impact of moderate adverse
significance is predicted during the construction
phase on the setting of the registered outstanding
historic landscape of the Milford Haven Waterway
and on designated built heritage assets situated
adjacent to the application site. However, following
completion of construction, pre-development
conditions will be re-established as a result of
reinstatement. As such, there will be an overall
negligible environmental effect in the medium and
long term.
8. No operational or decommissioning phase impacts
on cultural heritage resources from the proposed
pipeline development have been identified, and as
such potential impacts are anticipated to be
negligible.
Figure 5: View North from Road to Rhoscrowther
The Pembroke Refinery lies at the western extent of the photograph, and Martins Haven lies in the centre.
Figure 6: View North / Northwest from Road to Pwllcrochan (near entrance to Greenhill Farm)
The Pembroke Refinery lies in the background, the wet woodland and reedbed area in the middle ground, and the field to the south of Pwllcrochan Environmental Centre (formerly St Mary’s Church) in the foreground.
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High Pressure Natural Gas Pipeline, Chevron Ltd NTS-10
9. Whilst the proposed development will result in a
potentially moderate adverse effect on the cultural
heritage resource due to the truncation/removal of
archaeological remains, this adverse effect will be
offset by undertaking an effective mitigation
strategy that will produce an overall positive effect
of minor beneficial significance, in that further
knowledge will be gained on the archaeology and
historic landscape of this area.
10. By following the phased programme of mitigation
suggested, it is anticipated that the environmental
effect of the proposed pipeline development upon
known or unrecorded archaeology can be reduced
or removed to an acceptable level resulting in a
negligible impact.
5.6 Ground Conditions
1. The impact of the proposed development on
existing ground conditions has been assessed via
review and collation of readily available information
pertaining to the current condition of the soils and
groundwater beneath the application site and the
potential risks they pose to the environment and
future users. In addition, site investigation has been
undertaken along the proposed pipeline route and
surrounding area.
2. The ground conditions information collected does
not indicate a high potential for soil contamination
outside of the refinery fenceline. Therefore, there is
considered to be negligible impact from this section
of the works. The CEMP will include procedures to
be followed should contaminated soils be
encountered during construction works.
3. The impacts are therefore associated with
excavation for the foundations of the let down
station and the pigging station and for the buried
section of pipeline within the refinery boundary. The
potential sources of soil contamination are the
adjacent former ‘landfarm areas’ (licensed waste
disposal areas) and general soil contamination from
refinery sources.
4. If surplus soil cannot be re-used on site and needs
to be disposed of it will be done via an appropriate,
licensed landfill facility, in accordance with current
Duty of Care responsibilities and other statutory
requirements. Following mitigation the impact of
potentially contaminated soils are considered to be
negligible.
5. Given that groundwater is primarily found within the
bedrock, the excavations of the construction work
are considered unlikely to encounter significant
groundwater. Dewatering of groundwater from the
excavation will be included in the CEMP.
6. Whilst groundwater is anticipated to be below the
depth of the base of the trench, it may be present
within the depth of the trench at some points along
the pipeline. The backfilled trench is therefore
potentially a preferential pathway for groundwater,
and associated contaminant, movement. Ditch
breaks are included in the design in areas of
sloping terrain with the aim of reducing groundwater
flow. Implementation of these mitigation methods
will result in a negligible impact.
7. During decommissioning, it is anticipated that the
pipeline would be emptied, cleaned, sealed and
capped in-situ with above ground features
removed. Ditch breaks used to mitigate impacts
during the pipelines long-term operation will remain
in place to reduce flow of groundwater /
contaminants along the route of the disused
pipeline.
8. Overall, a negligible impact to the ground conditions
is expected to occur throughout the construction,
operational and decommissioning phases of the
proposed pipeline development.
5.7 Water Resources and Flood Risk
1. Milford Haven lies approximately 550m north of the
proposed pipeline route, and the mouth of the
Pembroke River is approximately 1km to the east.
2. There is also a small watercourse named ‘Martin’s
Haven Pill’ within the wet woodland and reedbed
area adjacent to Pwllcrochan Environmental
Centre, which the proposed pipeline will traverse.
The Martin’s Haven Pill surfaces as a series of
springs approximately 900m south of the proposed
pipeline route and flows in a northern / northeastern
direction through the Milford Haven Waterway
SSSI, before exiting into Milford Haven.
3. The application site lies within a flood zone which is
an area which has an Annual Exceedance
Probability (AEP) of flooding that is less than 0.1%
(1 in 1000 year event). Therefore, flood risk is
allocated a low importance.
4. Measures which are specific to each type of
potential pollution will be undertaken to help ensure
the impacts of these pollutants are mitigated,
including (but not limited to): silt-fences; washing
facilities; pre-coating measures; and bunding.
5. With the extensive and, in many cases, specialised
mitigation measures proposed, potential impacts
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High Pressure Natural Gas Pipeline, Chevron Ltd NTS-11
associated with the aspects listed above during
construction works are anticipated to be negligible
and insignificant.
6. Disturbance to groundwater during construction is
predicted to result in a minor adverse impact on
groundwater which will be temporary in nature and
of significance ranging from low to insignificant
depending on the leaching potential of the soils
involved.
7. Overall, with appropriate mitigation measures, the
impacts of the construction, operation and
decommissioning works of the proposed pipeline on
the hydrological regime are predicted to be, at
worse, moderate adverse and temporary in nature,
and therefore of low significance.
5.8 Traffic, Transportation and Access
1. The main access route to the application site is via
the B4320, which runs west from Pembroke
towards Angle on the coast. The road leading to
the application site and to the Pembroke refinery
runs north from the B4320. The two roads form a
simple T-junction.
2. Construction traffic will be generated by the
following construction activities: delivery of plant
and material; disposal of spoil and import of fill
material; and arrival and departure of employees.
The maximum increases in both total traffic and
Heavy Goods Vehicle (HGV) traffic occur during the
evening peak, and are 10.5% and 8.3%
respectively.
3. In order to construct the section of pipeline that
crosses the road, a road closure will be required.
The road provides access to Pwllcrochan
Environmental Centre (formerly St. Mary’s Church)
and the coastal footpath. There is no alternative
route for traffic, and therefore in the short-term the
impact of the pipeline construction will be major
adverse prior to mitigation. This closure is likely to
be limited to one or two days only however, and
outside the period of the road closure the impact on
the local highway network will be negligible.
Construction along this part of the route will not be
scheduled when events are to be held at the
Environmental Centre, and pedestrian access to
the graveyard will be provided. Overall the impact is
considered to be minor adverse in significance and
short-term in nature.
4. Bus services are infrequent and the bus route does
not pass close enough to the pipeline construction
site for commuting by bus to be feasible. Therefore
the impact of construction on public transport will be
negligible.
5. The number of additional walking and cycle trips
generated by the construction works is expected to
be negligible. There will be some inconvenience for
pedestrians and cyclists at the road crossing point,
but as the number of pedestrians and cyclists using
the road is very small, the impact is considered to
be negligible.
6. With the implementation of an agreed Traffic
Management Strategy, residual impacts of
construction on all modes of transport are
considered to be negligible. The only exception is
the short-term impact of the road closure to
Pwllcrochan Environmental Centre.
7. Other than occasional traffic generated by
maintenance staff there is not anticipated to be
operational phase traffic associated with the
proposed development. Decommissioning traffic is
also anticipated to be less than for the construction
phased. Therefore the impact on all modes of
transport is considered to be negligible.
5.9 Landscape and Visual Impact Assessment
1. The value of the rural landscape in the area is
considered by CCW’s LANDMAP dataset to be
‘outstanding’ for the Historical Landscape aspect. It
is ‘high’ for Cultural Landscape but it should be
noted that this area covers a large proportion of
Pembrokeshire’s countryside. For the other
LANDMAP aspects, the area is considered of
‘medium’ value.
2. The refinery and power station are considered of
low value in all aspects where separated from the
wider landscape.
3. The proposed pipeline development will also cross
and run close to the Pembrokeshire Coast Path,
which is considered of high sensitivity. During
construction, the impacts on users could be
substantial for a short length of the path near the
power station and for a short duration (anticipated
to be less than 5 days). The overall impacts are
therefore considered to be of minor adverse
significance. During this time a diversion route
would be provided, along with prior notice of
closures and diversions through the applicable
advertisements.
4. In the first year of operation the corridor created by
the pipeline including the removal of hedgerows
and woodland would be apparent. Users would
therefore experience some degree of impact.
Environmental Statement Non-Technical Summary
High Pressure Natural Gas Pipeline, Chevron Ltd NTS-12
Whilst the impacts would be slight on a potentially
high sensitivity receptor, overall the impact is
considered to be of minor adverse significance.
Proposed mitigation measures include the
production of a reinstatement plan and subsequent
reinstatement of hedges, reedbed, wildflower grass
sward in rough grass areas and agricultural land.
5. The potential impacts on the farmhouse at Greenhill
Farm are considered to be indiscernible during
construction and the first year of operation. There
are no other nearby dwellings.
6. During the first year of operation the hedges would
be reinstated leaving views of small gap in the
scrub woodland to the north. This effect would be
slight (on a high sensitivity receptor) resulting in an
impact of moderate adverse significance.
7. In terms of landscape elements all receptors are
considered to be of medium / low sensitivity due to
their size, pattern and location and following
mitigation the impacts are considered to be of minor
adverse significance.
8. With regard to landscape character the proposed
mitigation measures will stitch together the
landscape of the Peninsula Farmland Mosaic
character area reinstating hedgerows and
reedbeds. After 15 years, these will be well
established allowing only minimal opportunity to
perceive the small changes caused by the pipeline
corridor. Therefore, it is considered that an impact
of minor adverse significance will result.
9. The refinery and power station are considered to be
low sensitivity areas. The anticipated reduction in
flaring that will result would lead to a minor
beneficial indirect impact at the refinery.
10. The nature of the above ground pipeline is very
small-scale in the context of the adjacent developed
areas and is considered to be of negligible
significance with regard to the Pembroke Refinery,
and of minor adverse significance to the Pembroke
Power Station.
11. It is considered that there is a residual impact of
minor adverse significance on landscape elements
and on the Peninsula Farmland Mosaic character
area. All other residual landscape and visual
impacts are considered to be negligible. Therefore
it is considered that there are no significant impacts
on landscape and visual receptors.
5.10 Socio-Economics
1. It is estimated that there will be approximately forty
construction workers on-site during the peak of
construction activity, of which at least eight will be
permanent managerial staff required on-site. Local
sourcing of construction labour will be sought by
Chevron Ltd for works taking place outside the
refinery’s boundary, although the exact origin of
these workers will ultimately be dependent on
suitability. There are also potential beneficial effects
for local firms who secure contracts for ancillary
services during the construction phase. These
contracts would be for services and materials, such
as plant hire and for the transportation of
construction materials.
2. It is considered that the construction of the
proposed development will have a negligible to
minor beneficial effect on the local (Pembrokeshire)
economy, depending on whether local employees
and companies are utilised.
3. It is not anticipated that the proposed development
will generate any additional employment during its
long-term operational phase; therefore there would
be a negligible impact on the local economy in the
long-term.
4. It is anticipated that the decommissioning will be a
less labour intensive process than construction and
therefore the impact on employment generation is
anticipated to be negligible.
5. In summary, it is considered that this development
would have an overall negligible effect on the local
and regional economy as well as local tourist and
recreational activities, given that there will be no
impact during the operational phase and only short
term impacts during the 18-week construction
phase, which will be mitigated for. If local staff and
companies can be utilised it could lead to a minor
beneficial impact, though short-term in nature.
6. Residual Impact Assessment and Conclusions
1. The site preparation and construction could
potentially lead to short-term potentially adverse
impacts, such as on the landscape and visual
setting of the area, the archaeological landscape,
agricultural land use, and local hydrological regime
in the area. These will be limited to only a few
weeks in duration and a number of mitigation
measures (or actions) will be put in place to ensure
that these are minimised.
Environmental Statement Non-Technical Summary
High Pressure Natural Gas Pipeline, Chevron Ltd NTS-13
2. The operational impacts of the proposed pipeline
are predominantly negligible, with some minor
beneficial impacts anticipated with the employment
creation and recording of archaeological finds
during construction of the project, the removal of
potentially contaminated soils, as well as reduced
atmospheric emissions generated by substituting
Heavy Fuel Oil used at the Refinery with Refinery
Fuel Gas.
3. The proposed pipeline will make a positive
contribution towards meeting the sector limits for
atmospheric emissions of sulphur dioxide enforced
by the Environmental Permitting regime. There is
also predicted to be a noticeable reduction in
oxides of nitrogen and particulate matter due to the
development.
4. Overall, the proposed pipeline accords with the
overall objectives of planning polices at national,
regional and local levels, and is in accordance with
the governmental objectives for sustainable
development.
7. Contacts and Availability of ES
1. This NTS provides an overview of the findings of
the EIA. A full assessment of the environmental
impacts associated with the proposed development
is presented within the main ES. CD’s containing
the full ES are available free of charge from:
Jane James (Public Affairs Manager)
Chevron Ltd
Pembroke Refinery
Pembroke SA71 5SJ
2. The ES is available for viewing during normal office
hours at the Planning Department of
Pembrokeshire County Council. Comments on the
planning application should be forwarded to the
PCC at the following address:
Pembrokeshire County Council
Planning Department
1B County Hall
Haverfordwest
Pembrokeshire SA61 1TP