12 Soils and Land Use
12 SOILS AND LAND USE
12.1
Introduction
12.1.1
This chapter presents the assessment of potential impacts on land use and soils during the
construction and operational phases of the proposed development. Where appropriate,
mitigation measures are proposed and residual impacts identified and described.
a)
Scope of Assessment
12.1.2
This land use and soils assessment addresses the potential construction and operational phase
impacts on land to be directly utilised by the proposed development and, where relevant,
examines the potential for impacts on the land use and soils of adjacent areas around the
Development Site.
12.1.3
Due to the fact that many environmental aspects are interrelated, there may be a degree of
overlap with other chapters of the Environmental Appraisal, particularly those concerning
geology and contaminated soils. Where impacts are identified in the assessment that are
addressed in greater depth in relation to other environmental aspects (e.g. potential impacts
related to contaminated land, alterations to drainage regimes and impacts on biodiversity)
these impacts will be considered here but only in so far as how they may result from changes to
land use and soils.
12.1.4
With respect to geographical scope, this assessment focuses on the Development Site as
shown on Figure 12.1 (i.e. the Built Development Area West, Built Development Area East and
the Southern Construction Phase Area). For a full description of these areas see Volume 2
Chapter 1 of the Environmental Appraisal. However, to place the Development Site in context,
soil conditions and the Agricultural Land Classification (ALC) status in the local area and within
Somerset as a whole are also considered.
12.1.5
This chapter does not assess any issues relating to severance of farm holding or fields, impacts
of loss of land or crops on farm viability or other interruption to the operation of the current land
management units.
12.2
Legislation
12.2.1
A summary of relevant policies and guidance relating to land use and soils is provided below.
a)
12.2.2
European Legislation
The European Commission adopted a Thematic Strategy for Soil Protection (COM(2006) 231))
on 22 September 2006, in order to provide a comprehensive common framework for protecting
soils across the European Union. The EU Strategy includes: a proposed legislative framework
for the protection and sustainable use of soil, in order to integrate soil protection into national
and EU policies; measures to improve knowledge of soil functions; and measures to increase
public awareness. It seeks to establish rational land use planning practices at all levels of
government to ensure the sustainability of soils, consistent with a “precautionary principle”
used by the EU in establishing environmental policy.
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12.2.3
The Thematic Strategy includes proposals for an EU Soil Framework Directive requiring Member
States to adopt a systematic approach to identifying and combating soil degradation and
integrate soil protection into other policies - especially with respect to agriculture, regional
development, transport, and research. This proposed Directive has not yet been passed by the
European Parliament and Council of Ministers.
b)
12.2.4
UK Legislation
A brief summary of UK Regulations and guidance relevant to land use and soils is presented
below.
i)
12.2.5
The Wildlife and Countryside Act 1981 (as amended) (Ref. 12.1)
The Wildlife and Countryside Act restricts the introduction of certain animals and plants in
England and Wales. For example, potentially invasive species such as Japanese Knotweed and
Giant Hogweed are listed under Schedule 9 and subject to Section 14 of the Act which makes it
an offence to plant, or cause these species to grow in the wild. In addition, Japanese Knotweed
and Giant Hogweed are regarded as a controlled waste under the Environmental Protection Act
1990 and have to be disposed of at licensed sites or by burning on-site.
ii) The Environmental Stewardship (England) and Countryside Stewardship
(Amendment) Regulations 2006 (Ref. 12.2)
12.2.6
The Environmental Stewardship (England) Regulations 2005 and the Countryside Stewardship
Regulations 2000, both as amended by the Environmental Stewardship (England) and
Countryside Stewardship (Amendment) Regulations 2006. These regulations set out the
principles for Countryside Stewardship which was introduced as a pilot scheme in 1991 to
encourage farmers and land managers to enhance and conserve English landscapes, their
wildlife and history. The Countryside Stewardship Scheme has been superseded by the
Environmental Stewardship Scheme.
Environmental Stewardship is a voluntary agrienvironment scheme that provides funding to farmers and other land managers in England who
deliver effective environmental management on their land.
12.2.7
Entry Level Stewardship (ELS) is open to all farmers and land managers who want to deliver a
basic level of environmental management. The scheme requires a basic level of environmental
management and participants can choose from a wide range of management options. These
cover all farming types and include matters such as hedgerow management, stone wall
maintenance, low nutrient input grassland, buffer strips, and arable options. Higher Level
Stewardship (HLS) aims to deliver significant environmental benefits in high priority situations
and areas. It involves more complex environmental management and the preparation of a Farm
Environmental Plan.
iii) Planning Policy Statement 7 (PPS 7), Sustainable Development in Rural Areas (2004)
(Ref. 12.3)
12.2.8
PPS 7 is the key central government policy on development within the countryside. It sets out
policy for promoting development in rural areas whilst conserving the character of the
countryside and protecting the best and most versatile agricultural land. This best agricultural
land is defined as Grade 1, 2 and 3a under the UK Agricultural Land Classification (ALC) system.
Para 28 of PPS7 states:
“…the presence of best and most versatile agricultural land (Grades 1, 2 and 3a) should be
taken into account alongside other sustainability issues (e.g. biodiversity…. including soil
quality) when determining applications”.
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12.2.9
The loss of best and most versatile land (BMVL) is no longer of national importance (as was set
out in the precursor to PPS7, Planning Policy Guidance 7 (PPG7)) and the potential loss of BMVL
is now a matter to be taken into account at a local level.
iv) Soils Action Plan for England 2004-2006 (Ref. 12.4)
12.2.10 The First Soils Action Plan for England 2004-2006 was published in 2004. A draft version of a
proposed Soil Strategy for England was issued for consultation in March 2008. This Strategy
sets out a vision to improve the sustainable management of soil and address degradation
within 20 years. It covers a range of sectors including agriculture, land management, planning
and construction and provides a strategic framework for action that should facilitate the
Department for Environment, Food and Rural Affairs’ (Defra) work with delivery partners.
c)
Regional Policy
i)
West Somerset Local Plan (2006) (Ref. 12.5)
12.2.11 The West Somerset Local Plan adopted in April 2006 sets out a number of objectives relating to
the management of agricultural land and the wider countryside, including:



to protect the best and most versatile agricultural land;
to encourage the re-use of agricultural buildings; and
to conserve and enhance the quality and diversity of the countryside.
12.2.12 Policy A/2 of the West Somerset Local Plan states that:
“The best and most versatile agricultural land (grades 1, 2 and 3a) will be protected from
development. Planning permission for development affecting such land will only be
granted exceptionally if there is an overriding need for the development and either:
a) sufficient land of a lower grade (grades 3b, 4 and 5) is unavailable; or
b) available lower grade land has an environmental value recognised by a statutory or
non-statutory wildlife, historic or archaeological designation and outweighs the
agricultural considerations.
If best and most versatile land needs to be developed and there is a choice between sites
in different grades, land of the lowest grade available should be used."
12.3
Methodology
a)
12.3.1
Summary of Approach
There are no established or published methods for assessing the impacts of development upon
agricultural land, land use receptors or indeed soil loss and degradation. The impact
assessment therefore follows the approach set out in Volume 1 Chapter 5 involving the
following key steps:




definition of the current baseline;
impact assessment using the impact assessment matrix which combines the magnitude
and value/sensitivity assessments specific for soil, land use and agriculture as set out in
Tables 12.1 and 12.2;
identification of mitigation measures; and
assessment of any residual impacts after implementation of mitigation.
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b)
Definition of the Baseline
i)
12.3.2
Sources of Information
A number of information sources were used to establish the baseline land use and soil
conditions of the Development Site and wider area as follows:





Soil Survey of England and Wales (1984) Soils and Their Use in South West England. SSEW
Bulletin No 14, and associated Map Sheet No 5 (Ref. 12.6).
Findlay, D.C. (1965) The Soils of the Mendip District of Somerset. Memoir of the Soil Survey
of Great Britain, Harpenden (Ref. 12.7).
Groundsure report detailing environmental topics including historical mapping of site use;
local water abstraction licences; wastewater discharge consents; ecological designations
and protections; geological maps; groundwater vulnerability maps; geological memoirs,
landfill descriptions and distances; and agricultural land classifications (Groundsure report)
(Ref. 12.8).
MAGIC (Multi-Agency Geographic Information for the Countryside) website
(www.magic.gov.uk).
Previous studies carried out in relation to the West Hinkley Wind Farm (2006) (Ref. 12.9),
Hinkley A Environmental Statement (Ref. 12.10) and Hinkley C Environmental Statement
(Ref. 12.11).
ii) Surveys
12.3.3
In order to accurately assess the impacts to land use and soils that could result from the
construction and operational phases of the HPC development, the baseline land use and soil
conditions on and around the Development Site have been defined. The agricultural value of
the land which will be directly affected by HPC, based on 1988 MAFF definitions (Ref. 12.12),
was determined through ALC surveys undertaken in 2009 and 2010 (see Appendix 12a).
12.3.4
The presence of BMVL is a factor in the consideration of the sustainability of development
proposals as set out in paragraph 28 of PPS7 (Ref. 12.3). PPS7 promotes the creation of a
sustainable countryside framework, and places the loss of BMVL within the context of meeting
wider sustainability objectives.
12.3.5
The assessment of soil wetness, which is a key parameter in the determination of the value of
the soils present within the Development Site (see Table 12.2 below), has been undertaken in
accordance with the MAFF (now Defra) methodology (Ref. 12.12) as presented in Appendix 12b.
c)
12.3.6
The assessment addresses likely impacts of the development during the construction and
operational phases. The assessment of impacts on land use and soils relates to the following
key factors:



4
Assessment of Effects
the soil types and agricultural land classification likely to be affected by the development;
the type of farm enterprises present and farming practices including any agri-environment
schemes; and
the possible presence of crop/soil/animal diseases or noxious weeds.
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12.3.7
The assessment addresses potential impacts during commissioning tests, start-up and
continued operation of the nuclear power station. The operational phase of the development is
not expected to have any further impact on land use and soils beyond those caused during
construction.
12.3.8
The criteria used in this assessment are the ALC Grades as set out by the Ministry of Agriculture,
Fisheries and Food (MAFF) (now Defra) (1988) (Ref. 12.12). Supplementary criteria include soil
type and soil quality, crop types, presence of noxious weeds or crop/soil/animal diseases and
type and location of farm units.
12.3.9
The assessment follows the generic impact assessment matrix set out in Volume 1 Chapter 5.
The determination of the magnitude of change has taken into account the land area loss
thresholds previously adopted by MAFF (Ref. 12.12) when considering proposals involving more
than 20ha of BMVL. Table 12.1, below, sets out how these area loss thresholds have been
incorporated into the assessment of magnitude matrix. Where no impact would be detectable
this is defined as having “no or negligible impact”.
Table 12.1: Guidelines for the Assessment of Magnitude
Magnitude
Guidelines
High
Permanent or long-term (over 10 years) loss of over 50 ha of best and most versatile
agricultural land/entire regional/ resource of best and most versatile land (ALC
Grades 1, 2, 3a).
Existing land use will not be able to continue.
Medium
Medium to long term (5-10 years) loss of 20-50 ha BMVL, or large proportion of local
resource of BMVL.
Existing land use will be able to continue but noticeable changes occur.
Low
Temporary (2-5 years) loss of 10-20 ha of BMVL, or large proportion of local resource
of BMVL.
Existing land use will be able to continue but noticeable changes occur.
Very Low
Temporary short term (less than 2 years) loss of less than 10 ha of BMVL.
Short term adverse changes to the value of the receptor but recovery is expected in
the short term (0-1 years), and there would be no impact on its integrity. No material
change to existing land use. Loss or degradation of area of BMVL but a small
proportion of local resources.
No impact on overall agricultural land availability for wider area/region.
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12.3.10 With respect to value, the criteria set out in Table 12.2 have been used.
Table 12.2: Guidelines for the Assessment of Value
Value
Guidelines
High
Grade 1 agricultural land, specialised agricultural activity such as tree crops, soft
fruit, etc.
Irrigated agriculture.
Higher level Agri-environment scheme lands.
Soils with high wetness limitation affecting workability (wetness class V or VI).
Medium
Grades 2 and 3a agricultural land.
Annual horticultural cropping (non-irrigated).
Entry level Agri-environment scheme lands.
Soils with moderate wetness limitation affecting workability (wetness class III or IV
Low
Grades 3b and lower agricultural land.
Arable or grassland areas.
Soils with low or no wetness limitation affecting workability (wetness class I or II).
Very Low
12.4
Baseline Environmental Characteristics
a)
12.4.1
Introduction
This section presents the baseline environmental characteristics for the Development Site and
surrounding areas with specific reference to land use and soils. It should be noted that a
description of baseline conditions with respect to potentially contaminated soils is provided
within the Environmental Appraisal chapter on Contaminated Land (Chapter 13).
b)
12.4.2
Sources of information
A number of information sources have been reviewed to establish the baseline land use and
soil conditions of the Development Site and wider area as follows:
i)
12.4.3
6
SSEW Bulletin Number 14 and associated Map Sheet No 5 (Ref. 12,6)
The SSEW Bulletin provides generalised descriptions of the soil types across England and Wales
which are mapped at a scale of 1:250,000. No site-specific information on soils is provided for
the Hinkley Point area. Information on the mapped soil types is provided below
ii)
12.4.4
Feature / receptor identified as being generally tolerant of the proposed change, i.e.
of low sensitivity. Feature / receptor possesses low biodiversity, social/community
value and / or economic value. Feature / receptor is common.
Findlay (1965) The Soils of the Mendip District of Somerset (Ref. 12.7)
This Memoir and map provides an earlier and more detailed description and mapping of soils in
North Somerset than the SSEW Bulletin 14 and associated Map Sheet No. 5.
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iii) Groundsure Report (Ref. 12.8)
12.4.5
This report provides information on the historical mapping of site use, such as local water
abstraction licences, wastewater discharge consents, groundwater vulnerability maps and
geological maps. It does not provide a description of agricultural land use or type and quality of
soils for agriculture.
iv) MAGIC website
12.4.6
The MAGIC website (www.magic.gov.uk) contains an interactive map with GIS information from
a number of different UK Government departments and agencies, including Natural England, the
Environment Agency, the Department of Communities and Local Government and Defra. It
shows that the Development Site is part of an Environmental Stewardship Scheme,
administered by Natural England. The MAGIC website also provides mapping of indicative ALC
at a scale of 1:250,000.
c)
Previous Studies
i)
12.4.7
West Hinkley Wind Farm Environmental Statement (ES) (2006) (Ref. 12.9)
The West Hinkley Farm ES provide a description of the site as follows:
“topography of the site consists of gently rolling farmland with two east-west trending ridges
forming the topographic high points. The intervening valleys are broad and shallow. The
land use is generally arable farming with some beef cattle with natural grassland and
improved grassland.”
12.4.8
There is no specific consideration given to agriculture, land use or the type and quality of soils
for agricultural purposes.
ii) The Central Electricity Generating Board (CEGB) Hinkley C Environmental Statement
(ES) (1987) (Ref. 12.11)
12.4.9
This ES provides a generic description only of land use, origin of soil materials and agricultural
land classification. Land use around Hinkley Point is described as a mixture of arable land and
agricultural grazing land with a number of isolated woodland copses and extensive hedgerows.
12.4.10 At the time of writing, the CEGB Hinkley C ES, the land quality for agricultural uses was
classified according to MAFF’s ALC system as Grade 3, but of undetermined sub classes. To the
south and east of the Hinkley Point C Development Site the land is flat, low lying and classified
as ALC Grade 4. The land owned at the time by the CEGB is classified as “other land” and has
no agricultural grade.
12.4.11 The report describes soils of the site as consisting of previously deposited fill material and the
weathered products of in-situ rocks and transported materials. Transported materials include
“head deposits” formed by the mass movements of soils down slope and periglacial
disturbance, both resulting from the effect of freezing and thawing of the ground during the
Quaternary Ice Age. Other soil deposits include marine estuarine deposits and fluvial glacial
sands.
d)
Agricultural Land Classification Survey
12.4.12 To establish the ALC, soil survey data was combined with information on the topography and
climate of the area to provide an assessment of the land classification in accordance with MAFF
guidelines (MAFF 1988). Land grade is determined by a combination of soil types, drainage
status, climatic factors and topography (land gradient). The ALC system classifies land into five
main categories (Grade 1 to 5) and two subdivisions within Grade 3, i.e. classes a and b. Grade
1 is the highest quality land with no or very limited restriction to agricultural use. Grade 5 is of
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least agricultural value, usually only of limited grazing use. Under PPS 7, Grades 1, 2 and 3a
are defined as BMVL and are a national resource to be protected.
e)
Land Use Description
12.4.13 The Development Site is generally open countryside, primarily in agricultural use (mixed pasture
and arable) with some small areas of woodland, scrub and grassland and the current nuclear
installations in the north-east. Adjacent land use to the south and west is also primarily
agricultural. Within the Built Development Area West, there are three derelict barn buildings.
One is located close to Wick Moor Drove, with the others being located towards the centre of
this area.
12.4.14 The topography of the Development Site comprises undulating countryside, terminating at
Bridgwater Bay to the north at a natural cliff which descends to a shingle beach. The
topography is generally typical of that in the wider locality, with the exception of the Built
Development Area East where the land has been modified through construction of the existing
Hinkley Point B power station.
12.4.15 Within the Built Development Area West and the Southern Construction Phase Area are a series
of east-west trending ridges and depressions. The lowest terrain within the Development Site is
formed by the shallow valley which runs along the boundary between the Built Development
Area West and the Southern Construction Phase Area, in which Holford Stream is located. North
of this depression, within the Built Development Area West, the ground rises sharply towards a
ridge along which an agricultural access track runs (the Green Lane).
12.4.16 There are a series of agricultural drainage ditches present within the Development Site, running
along field boundaries. Two surface drainage features are present within and adjacent to the
Built Development Area West, one running west to east along a field boundary in the northern
part of this land parcel before turning northwards towards the coastline. Site reconnaissance
has confirmed these water features serve as agricultural drainage ditches which are to be
ephemeral (i.e. seasonally dry).
f)
Historic Land Use
12.4.17 A review of historical maps and plans included within the Groundsure report described above
has identified that both the Built Development Area West and Southern Construction Phase
Area have remained as greenfield agricultural land since the earliest available map was
published in 1886. Within the Built Development Area West, a farm named Benhole Farm was
located in the north western corner of this land parcel until around 1976 when it was
demolished to leave a single remnant outbuilding which is still present on-site, along with two
other derelict farm buildings.
12.4.18 The Built Development Area East comprised greenfield, predominantly agricultural land, until
1975 when a small sewage works was constructed towards the western boundary. Also, during
the construction of Hinkley Point B, an accommodation / construction camp and fabrication
area with associated electrical sub stations were developed on the southern section of the area.
By 2005, a visitors' centre had also been constructed in this area. The Built Development Area
East lies within the existing Hinkley Point Power Station Complex but is not in intensive use. The
improved grassland areas within this area are grazed annually. Other areas are maintained in
Good Agricultural and Environmental Condition (GAEC).
12.4.19 Use of the land surrounding the Development Site has remained predominantly agricultural
with the exception of the construction and operation of the existing Hinkley Point Power Station
Complex to the east.
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g)
Description of Soil Types
12.4.20 The more generalised distribution of soil types provided in the SSEW Bulletin Number 14 and
associated Map Sheet No 5 at a scale of 1:250,000 indicates that the majority of the site
consists of soils of the Evesham Association which are described as being only slowly
permeable, calcareous clayey brown earths.
12.4.21 Further detail of different soil types and their distribution at Hinkley Point is provided in Findlay
(1965) and it is this reference which is the primary source of information used in this section.
The more detailed descriptions and distributions of soils are mapped at Soil Series level,
compared to the more generalised Soil Association level of the SSEW Bulletin 14. The following
descriptions are taken from both scales of mapping.
12.4.22 Four soil types (identified as Soil Series) are mapped by Findlay (1965) for the land within the
Development Site:




h)
Evesham Series: Slowly permeable, calcareous, clayey soils with some loamy soils over
clayey subsoils. Some seasonal waterlogging. Developed over Jurassic and Cretaceous
clay;
Worcester Series: Reddish, slowly permeable clayey soils developed over Permo-Triassic
Mercia mudstone and clay shales (previously described as Keuper Marls by Findlay (1965)).
Some seasonal gleying;
Butleigh Series: Calcareous, slowly permeable clay soils developed over fine-textured
alluvium and colluvium derived from calcareous Lower Lias shales and clays; and
Compton Series: Reddish brown clay soil developed over fine-textured alluvium and
colluvium derived from Permo-Triassic Mercia mudstone and clay shales (described as
Keuper Marls by Findlay (1965)).
Geographical Distribution of Soil Types
12.4.23 The geographical distribution of the soil types listed above is provided in Figure 12.2.
12.4.24 The northern and southern parts of the Development Site, including the Built Development Area
West and the Built Development Area East, consist of soils of the Evesham Soil Series. These
slowly permeable soils require artificial drainage to enable cultivation. They can be subject to
seasonal waterlogging which results in poaching if stock are grazed on the land in early Spring
or late Autumn.
12.4.25 Holford Stream valley in the Southern Construction Phase Area consists of alluvial and colluvial
gley soils of the Butleigh Series. In this location, these soils have high groundwater levels,
seasonal flood risk and, in places, are intensely gleyed. Cultivation is dependent on artificial
drainage and soil damage and poaching can result from use of equipment or stocking in early
Spring or late Autumn when the soil is wet.
12.4.26 There are two small areas of silty clay Worcester Soil Series in the western part of the site,
picking out the easily weathered and eroded Mercia mudstones.
12.4.27 The northern part of Bum Brook valley in the southern part of the Southern Construction Phase
Area consists of redeposited soils of the Compton Series which, in this location, are seasonally
waterlogged and, in places, intensely gleyed, requiring artificial drainage to enable cultivation.
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12.4.28 Soils of the Evesham 2 Association (described as Evesham Soil Series by Findlay (1965) are
described by the Soil Survey of England and Wales as:
“…slowly permeable soils which are subject to winter waterlogging. Evesham 2 soils are wellstructured and respond well to artificial drainage (Wetness Class II or III). Evesham 2 topsoils
are difficult to cultivate and can only be satisfactorily worked over a narrow range of moisture
content, so timeliness is essential. There are few opportunities for landwork in spring,
especially in wet years, and the soils are best cultivated in autumn and sown to winter crops.
Winter cereals, particularly wheat, and grass are the main crops. Some oilseed rape is grown as
a break crop. Grass yields are limited by droughtiness and the appreciable poaching risk
reduces the safe grazing period”.
12.4.29 Described as Wetness Class II-III (see Appendix 12b), Evesham 2 soils can be waterlogged
within 70cm of the surface for up to 180 days per year, thus limiting the season of soil
workability.
12.4.30 The Soil Survey of England and Wales (Ref. 12.6) describe the Worcester Association (described
as the Worcester Soil Series by Findlay (1965) (Ref. 12.7)) as:
“….normally seasonally waterlogged (Wetness Class III) but on slopes greater than 11 degrees
this may be reduced to Wetness Class II. The slowly permeable subsoils cause rapid winter
runoff. These soils benefit from drainage measures but they compact easily so careful
management is needed if improvements in soil water regime are to be maintained.”
12.4.31 Findlay (1965) describes the Butleigh Soil Series as:
“…found on flat or gently sloping land which receives drainage waters from adjoining high
ground in winter but is rarely flooded. The internal drainage is slow and a zone of permanent
waterlogging may be present below 3ft (approx 900mm).”
12.4.32 Findlay (1965) describes the Compton Soil Series as:
“…occurring at the foot of steep slopes where downwash rests on estuarine clay or peat at
depths normally in excess of 3ft (approximately 900 mm). Where peat is shallower, surface
mineral soils become more intensely gleyed.”
12.4.33 The distribution of Compton soils on-site is limited to the very southern boundary of the
Development Site. These soils north of Shurton have been identified as being ‘teart’ soils,
showing higher than normal concentrations of molybdenum, which can lead to toxicity in cattle
grazed on herbage from these soils. No local evidence of this effect has been found at Hinkley
Point.
12.4.34 Soil Wetness classification was not in use at the time of the Findlay study (1965). However, the
location of both Butleigh and Compton soils in the lower parts of the Holford Stream and Bum
Brook valleys contributes to their seasonal wetness and both soils are gleyed in subsoil and
often in topsoil horizons. Both poorly drained soils would be classified as Wetness Class IV
under the MAFF (now Defra) (1988) Agricultural Land Classification of England and Wales (Ref.
12.12) as set out in Appendix 12a.
12.4.35 All four soil types are vulnerable to damage at certain times of the year because they are
workable only within a narrow moisture range, hence Winter working under wet conditions is
likely to cause compaction and damage to soil structure.
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i)
Results of the Agricultural Land Classification (ALC)
12.4.36 Published, broad scale mapping of agricultural land quality (ALC status) has identified the
entire Development Site and most of the surrounding land as being of Grade 3, although this
has not been subdivided into Grades 3a and 3b. This grade split is the divide between what
central government policy defines as BMVL (Grades 1, 2 and 3a) and land of only moderate
quality. There is a small area of Grade 4 land to the south and east of the Hinkley Point B Site.
12.4.37 Field survey results of ALC conditions (see Appendix 12a) indicate that the principal constraints
to agriculture within the Development Site are:





seasonal soil wetness; from soil profile impermeability and the presence of heavy textured
impermeable layers in soil profiles, exacerbated by the slightly longer than average field
capacity period of 167 days in this district in an average year, which combine to limit soil
workability and the opportunity days for working the land:
superficial stoniness, often associated with shallow soil depth, which makes cultivation,
seed-bed preparation and seed sowing difficult;
locally steep gradient, often associated with an uneven land form in some fields and
occasional rock outcrops, which hinder cultivations;
cumulative wetness in Holford Valley, which is a receiving site, which causes prolonged
wetness and seriously limits soil workability and the opportunity days for landworks; and
exposure to strong winds, sometimes salt-laden, which may damage crops.
12.4.38 The range of arable cropping is considered to be restricted to Autumn-sown cereal and oilseed
rape crops, or grass. The steep south-facing scarp to the north of the central valley has
gradients in excess of 7° which limit the land quality to no better than Subgrade 3b, and
gradients in excess of 11°, but less than 18°, limit the land quality to no better than Grade 4.
The downgrading is based on the hazardous nature of operating agricultural equipment on
steep slopes.
12.4.39 The areas occupied by the various ALC grades for the Development Site are given in Table 12.3
below (adapted from the RAC ALC Report 2010 – Appendix A). Approximately 73% of the land is
classified as Moderate Quality Agricultural Land (Subgrade 3b). 14% of the agricultural land onsite is Subgrade 3a which falls within the category of BMVL (ALC Grades 1, 2, and 3a). This band
of Subgrade 3a, good quality agricultural land, crosses the southern part of the Built
Development Area West. The remaining 13% is Poor Quality Grade 4 land. In the wider context,
Figure 12.3 illustrates the distribution of ALC Grades across Somerset and Table 12.4 provides
approximate total areas of ALC Grades across Somerset, based on ALC data provided by Natural
England.
Table 12.3: Agricultural Land Classifications (ALC) for the Development Site
Grade
Description
Area (ha)
Area
(% of agricultural
land)
Subgrade 3a
Good quality
19.8
14
Subgrade 3b
Moderate quality
102.6
73
Grade 4
Poor quality
18.8
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Grade
Description
Area (ha)
Area
(% of agricultural
land)
Total Agricultural
141.2
100
Non-agricultural land
30.2
Total Land
171.4
Table 12.4: Agricultural Land Classifications (ALC) for Somerset
ALC Grade
Approximate Area (ha)
Grade 1
9,342
Grade 2
33,365
Grade 3
204,108
Grade 4
61,706
Grade 5
22,712
Non-Agricultural
6,572
Urban
6,653
j)
Agricultural activity and crops
12.4.40 With the exception of the Built Development Area East, which lies within the existing Hinkley
Point Power Station Complex, historic and current land use within the Development Site is
primarily agricultural, comprising arable (including oil seed rape and wheat) or grazing use.
Some areas of land are non-farmed woodland and scrub habitat. There are small areas of nonfarmed grassland alongside ditches and along cliff tops. Hedgerows and fences form field
boundaries.
12.4.41 Field observations made during 2008 noted fields within the Development Site planted with oil
seed rape and wheat, with smaller areas used for hay production and grazing. Photographs
which illustrate the agricultural activity taking place across the Development Site are provided
below.
Built Development Area West
12.4.42 Approximately a third of the Built Development Area West consists of permanent pasture and
the rest is arable, primarily cereals (wheat). There are three fields in this part of the site which
are permanent grassland, with only the two inland fields being used for cattle grazing (see
Photographs 1 and 3). Permanent grassland in the field along the cliff top (Photograph 2)
appears to have been re-sown with a grass and wildflower seed mixture approximating National
Vegetation Classification (NVC) MG6c.
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Photograph 1: View north from main ridge in Built Development Area West, with re-sown
permanent pasture in foreground (July, 2008)
Photograph 2: View south west from coastal footpath in Built Development Area West, with resown permanent grassland in foreground (July, 2008)
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Photograph 3: Permanent grassland in Built Development Area West, looking east towards
Hinkley Point A power station (July 2008)
12.4.43 Between the Green Lane and ridge which runs west to east through this part of the site, the
arable fields were planted with oil seed rape in 2008 and wheat in 2009. The western area of
this part of the site was planted with wheat in 2008 (Photographs 4 and 7) and oil seed rape in
2009.
Photograph 4: View north in the western part of Built Development Area West, showing wheat
in the middle ground and edge of western woodlands (July, 2008)
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Built Development Area East
12.4.44 The whole of the Built Development Area East is included in the Hinkley County Wildlife Site and
consists of areas of pasture for cattle grazing, mixed deciduous woodland and overgrown,
scrubby hedgerows.
Southern Construction Phase Area
12.4.45 As for the Built Development Area East, the Southern Construction Phase Area, south of Green
Lane, consists of a mosaic of land used for oil seed rape or wheat, with permanent grassland in
Holford Stream valley for cattle grazing and grass conservation (hay or silage) (Photographs 5
and 6).
Photograph 5: Looking south from Green Lane, across the Southern Construction Phase Area,
with Holford Stream valley in the middle ground and mature oil seed rape in the foreground (July
2008)
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Photograph 6: Looking south from Green Lane, across the Southern Construction Phase Area,
with Holford Stream valley in the middle ground and mature wheat in the foreground (August
2009)
Photograph 7: Looking south west from the ridge in the centre of Built Development Area West,
across fields of mature wheat (August, 2008)
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k)
Land Subject to Agri-Environment Schemes
12.4.46 Much of the land within the Development Site is currently entered into the Countryside
Stewardship Scheme, as shown on Figure 12.4.
i)
Built Development Area West
12.4.47 The majority of the land within the Built Development Area West is part of a Countryside
Stewardship Agreement. This land is now owned or leased by EDF Energy and as a result of the
proposed HPC development the Environmental/Countryside Stewardship Agreement will come
to an end.
ii) Built Development Area East
12.4.48 The area of land west of the Hinkley Point A power station is the subject of an entry level
Stewardship Agreement. This land is now owned by EDF Energy and as a result of the proposed
development the Agreement will come to an end. British Energy has a Soil Management Plan
for its agricultural holding within this area.
iii) Southern Construction Phase Area
12.4.49 The Southern Construction Phase Area, which includes the Holford Stream valley, is the subject
of an entry level Environmental Stewardship Agreement. The majority of this land is now owned
or leased by EDF Energy and as a result of the proposed development the Stewardship
Agreement will end.
l)
Common Land
12.4.50 There are two small land areas, adjacent to but outside of, the Southern Construction Phase
Area identified by the Land Registry as Common Land (shown on Figure 12.5). Common Land is
legally defined under the Commons Registration Act 1965 as "land subject to rights of common
(as defined in [the] Act) whether those rights are exercisable at all times or only during limited
periods; and waste land of a manor not subject to rights of common". Common land is subject
to “rights of common”, which entitles commoners to graze certain stock or the right to collect
turf or wood. The commoners are usually defined as living in a particular parish or village, but a
common can still survive as a legal entity even if there are no longer any commoners. Commons
have to be registered under the 1965 Act.
12.4.51 Section 194 of the Law of Property Act 1925 prohibits “the erection of any building or fence, or
the construction of any work, which prevents or impedes access to land which was subject to
rights of common on 1 January 1926” without the consent of the Secretary of State.
Landowners can apply to the Planning Inspectorate under Section 16 of the Commons Act 2006
for the common to be de-registered. The land owner must offer an alternative piece of land to
the commoners.
12.4.52 The two areas of Common Land are excluded from the Development Site and are not impacted
by the proposals.
m)
Invasive and Alien Weed Species
12.4.53 Invasive weed species such as Japanese knotweed and ragwort are not currently considered to
be widespread or invasive within the Development Site. The baseline habitat surveys for the
Development Site have not recorded any presence of Japanese knotweed for example and,
although these surveys were not primarily concerned with identifying invasive species, the
presence of such species would be recorded if observed in the course of survey.
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n)
Animal Burial Pits
12.4.54 The Animal Health Division of Defra has been consulted about the potential presence of any
animal burial pits relating to foot and mouth or other disease outbreaks. No such pits are
recorded within the Development Site.
12.4.55 It should be noted that burial pits were not registered before 1972, and individual animals
could still be buried without registration up to the early 1990s. The potential for unrecorded
burials being present within the Development Site, although low, cannot be completely
discounted.
o)
Summary
12.4.56 With the exception of the Built Development Area East which lies within the existing Hinkley
Point Power Station Complex, historic and current land use within the Development Site is
primarily agricultural, comprising arable (including oil seed rape and wheat) or grazing use.
Some areas of land are non-farmed woodland and scrub habitat.
12.4.57 The majority of the agricultural land within the Built Development Area West (86%) is moderate
or poor quality land. A smaller proportion (14%) of the land is classified as BMVL (Grade 3a).
Much of the land within the Development Site is covered by agri-environment schemes.
12.4.58 The value of the agricultural land within the Development Site is therefore considered to be lowmedium overall, with the agricultural land classification being predominantly Subgrade 3b.
12.5
Assessment of Impacts
12.5.1
This section focuses upon those elements of the construction and operational stages of the
project that have the potential to affect land use and soils within the Development Site. A
description of the construction phasing, activities, construction methods, materials and
infrastructure is presented in Chapters 2 and 3 of this volume of the Environmental Appraisal.
a)
12.5.2
By the very nature of the construction process, the key activities that have the potential to
impact land use and soils largely relate to the clearance and preparation of the site prior to the
construction and installation of the main power station infrastructure, including:





12.5.3
land clearance and fencing;
stripping off topsoil and excavation of subsoils and transfer to stockpile or storage area(s);
site levelling to create the main site platforms for the nuclear islands and other platforms at
various different levels for other buildings and infrastructure;
construction of the infrastructure network including roads, drainage network and temporary
construction site drainage;
construction of temporary and permanent structures.
These construction activities have the potential to generate a number of possible direct and
indirect adverse effects both on-site and off-site. These are likely to include, but are not to be
limited to, permanent and temporary land take, loss of soils, loss of crop productivity, loss of
land for livestock and loss of land currently managed under agri-environment schemes. The
main potential impacts during the construction phase of the development are:


18
Construction Impacts
permanent loss of agricultural land, a proportion of which is classified as BMVL; and
soil damage as a result of topsoil stripping, movement and stockpiling.
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i)
Loss of Land and Change in Land Use
12.5.4
As a result of construction, principally the site preparation works, there will be a direct loss of
agricultural land and change in land use predominantly within the Development Site. The
majority of this loss of agricultural land and change in land use is likely to be permanent or at
least long term over the lifetime of the facility. Some land take impact will be short
term/medium term during the construction period, with land required on a temporary basis and
then restored post-construction. Of the total Development Site area approximately 171.4ha
site, approximately 66.6ha of land will be permanently lost to constructed features, however
post-construction, it is proposed that approximately 105ha of land would be restored to arable
agricultural land, grassland, woodland and scrub, hedgerow and wetland habitats (see Figure
2.1 in Chapter 2 of this volume).
12.5.5
The construction phase of HPC directly affects 19.8ha of land defined as BMVL (Grade 3a)
(Table 12.3, based on ALC survey Appendix 12a). This is the Grade required to be taken into
account in the context of being a material consideration of the sustainability of development
proposals (paragraph 28 of PPS 7) in line with the Government’s expectation that a “high level
of protection” is to be afforded to all natural resources (guidance contained in PPS1 on
sustainable development). PPS7 promotes the creation of a sustainable countryside
framework, and places less emphasis on the loss of BMVL than the preceding PPG7. The 19.8ha
of Grade 3a land equates to 14% of the total area of agricultural land affected within the
Development Site.
12.5.6
The combined area of Grade 3a and 3b land affected within the Development Site (122.4ha)
represents approximately 0.06% of the total (undifferentiated) 204,108ha of Grade 3 land in
Somerset as a whole (Table 12.4).
12.5.7
Using the criteria set out in Section 3 above, the agricultural land quality within the
Development Site is assessed as of low-medium value, taking into account the Grades that are
present and their extent both within the Development Site (Table 12.3) and across Somerset
(Table 12.4). The impact of construction and direct land take on agricultural land use and
quality is certain to occur, and ranges from short term, in areas required only for ancillary
construction activities, to long term or permanent within areas containing the main facility
structures.
12.5.8
The magnitude of the loss of agricultural land is assessed as low given the overall area (19.8ha)
of BMVL affected within the Development Site, and as a proportion of Grade 3 (undifferentiated)
land across Somerset as a whole (Tables 12.3 and 12.4, and Figure 12.3). ALC data made
available from Natural England does not differentiate between Grades 3a and 3b, hence the
total area of Grade 3a land across Somerset cannot be determined. However, from Tables 12.3
and 12.4 and Figure 12.4, it can be seen that the amount of Grade 3a land directly impacted by
the HPC development (both temporarily and permanently) is an extremely small proportion of
the overall available Grade 3 (undifferentiated) agricultural land in Somerset; that is as a worst
case less than 0.06% of Grade 3 land in Somerset.
12.5.9
Taking into account the relatively small-scale loss of BMVL and the less than 0.1% loss of Grade
3 land as a total, the significance of this loss is considered as of minor adverse significance.
This rating is provided within the context of agricultural land usage (and potential production)
as a whole rather than from the perspective of the economic viability of the landholding.
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ii) Impacts on Soil Quality and Profiles
12.5.10 Since the in situ soils are predominantly heavy clays with relatively poor structure, construction
works could lead to compaction, loss of soil structure and the creation of impermeable
conditions as soils are excavated, handled and stored for later re-use. As described in Section
12.3, Evesham 2 soils are vulnerable to damage at certain times of the year because they are
workable only within a narrow moisture range, as such they are considered to be of
medium/high sensitivity. Due to the proposed reuse of these soils within the proposed
Landscape Restoration Plan the soils are considered to be of medium value.
12.5.11 The construction works would disturb soil profiles and could adversely affect soil quality and its
future value as topsoil for restoration activities. Adverse impacts on soil productivity could also
arise as a result of tracking of machinery and other short-term construction-related activities
over un-excavated areas, causing localised compaction of soils.
12.5.12 Topsoil will be the first material to be stripped, but may be the last to be re-used. The
temporary storage of some excavated materials will therefore be necessary, and the location of
such storage area or areas will also have an impact on land use. The potential impact of these
stripping and storage activities could result in damage to the soil structure, integrity and
profiles without mitigation measures in place.
12.5.13 Soil stripping will involve the removal of all vegetation and the initial 250mm of topsoil
material. Conventional equipment such as bulldozers and scrapers will be used. Generally,
topsoils will be stripped, handled and stored separately from other soil materials; however
during the stripping process it is possible that the thinner deposits will become contaminated
with the underlying superficial deposits and may require separate storage. Bulldozers will also
be required for grading and sealing of the topsoil stockpile. Soil and subsoil will be temporarily
stockpiled within the Southern Construction Phase Area.
12.5.14 Initial estimates of the potential volume of topsoil indicate a bulked volume for stockpiling of
approximately 283,040m3. The total amount of soil material that may be temporarily stockpiled
is likely to approach 2 million m3. However, not all of this will be stockpiled at any one time, as
material will be progressively added and removed throughout the construction phase.
12.5.15 The majority of stripped topsoil will be stored for between seven and ten years. The impact on
soil quality and profile on-site will be site specific, adverse and direct due to the scale of soil
stripping, movement and length of storage time that will be required. The spatial extent is likely
to cover all, or a significant proportion of, the development site and will include a proportion of
the Southern Construction Phase Area where temporary stockpiling and potentially permanent
placement of spoil could occur. The impact will be both permanent (i.e. topsoil will be removed
from areas of the Development Site used for buildings hardstanding and certain permanent
infrastructures such as roads) and temporary (i.e. some topsoil will be replaced and re-used
over time).
12.5.16 Potential impacts as a result of damage to the physical soil structure, integrity and profiles
arising during compaction and disturbance, without any mitigation, may adversely affect soil
quality and its future capacity for use within the proposed landscape restoration plan.
12.5.17 In consideration of the size of the area that would be subject to restoration (107ha) and the
proposed land uses, as set out in Chapter 3 of this volume, to include the provision of
functioning agricultural land and conditions suitable for the establishment of a range of seminatural habitats, the potential impact on soil quality (in particular on the physical soil quality)
and soil profiles is considered to be of moderate adverse significance, prior to any mitigation
being implemented.
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iii) Agricultural Activity
Within the Development Site
12.5.18 The loss of agricultural quality soils has the potential to adversely affect farm enterprises and
viability. However, in this context, it should be noted that the land necessary for the proposed
works is wholly owned or leased by the EDF Energy.
12.5.19 The development will affect land currently under Entry Level Environmental Stewardship and
Countryside Stewardship Schemes. Implementation of these Schemes within the Development
Site would cease as a result of the proposed development. This change is not assessed as an
impact as the land required (wholly controlled by the EDF Energy) will not form part of
operational farming activity and hence will not be part of agricultural production. Any
environmental or ecological benefits arising from the agri-environment schemes impacted by
the change to land use are addressed in Chapter 18 on terrestrial ecology chapter.
Off-site Effects on Agricultural Landholdings and Activities
12.5.20 Farming activity (including crops and other vegetation, and livestock) beyond the boundaries of
the Development Site could potentially be affected by disturbance during construction,
including dust generation/deposition during earthworks and surface run off.
12.5.21 Dust can be generated from machinery movements on exposed, dry soils, soil stockpiles and
excavation activities. If dust becomes airborne it could be transported and then deposited on
nearby agricultural land and taint or adversely affect stock pasture or crops. It should be noted
however that due to the relatively short distance that dust will travel before it is deposited, this
impact is only a risk to land immediately adjacent to active working locations within the
Development Site. Such impacts are considered to be unlikely and would be highly localised
and restricted to land immediately adjacent to construction areas. The impacts would also be
short term and reversible. Generally, it can be stated that the effects of dust deposition are
unlikely to be significant unless large volumes of material are involved or the area affected
would be extensive. Standard and good practice measures would be put in place during
construction to manage and reduce the creation and transport of dust outside of the actual
construction area (see Section 6 below). With these measures in place it is not expected that
there would be any significant impact on the productivity of adjacent agricultural holdings as a
result of dust generated during the construction works.
12.5.22 Drainage works within the Development Site include the re-routing of existing surface drainage
systems, installation of a temporary de-watering system and installation of a deep underground
drainage system. Surface water from the working areas will be captured and discharged as part
of the temporary drainage of the construction site. Within the Development Site, there will be
no or negligible direct impact on soils and land use over and above that identified for
vegetation and topsoil removal. The temporary drainage facilities will help to maintain soil
contained in stockpiles in a viable condition for re-use.
12.5.23 Off-site, farming activity (including crops and other vegetation, and livestock) adjacent to the
boundaries of the Development Site could potentially be affected by localised changes to
surface runoff (e.g. from terraced areas, haul roads and soils/materials stockpiles). Such
impacts are unlikely, since a temporary surface water drainage system, and a sediment and
water management plan will be put in place. If any impact did occur, it would be highly
localised and restricted to land immediately adjacent to working areas. The impacts would also
be short term and reversible. As such, with respect to the hydrological aspects of land use or
agricultural production outside of the Development Site, the potential impact during
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construction is considered to be negligible. Further information on the changes to drainage
infrastructure and processes are covered under Chapter 15 on hydrology and water quality.
12.5.24 There will be no soil stripping or stockpiling of soil beyond the Development Site, hence there
will be a negligible direct off-site impact on agricultural land quality. Similarly, no soil
disturbance will take place outside the Development Site, as such there will be no direct off-site
impacts on soils.
iv) Spread of Invasive and Noxious Weed Species
12.5.25 During the construction phase, a large area of land will be cleared of vegetation and extensive
earthworks will take place, including excavation and storage of topsoil and subsoil. The areas
of bare ground thus created provide opportunities for colonisation by a variety of plant species,
including potentially noxious and invasive weeds. If left uncontrolled, these could potentially
spread beyond the Development Site on to adjacent land areas, where they could prove a
nuisance with regard to the management of adjacent agricultural areas, particularly in arable
use. This is not such an issue in areas where land is in permanent pasture, as the conditions
for establishment of invasive species is very limited and considered to be negligible with the
potential magnitude of effect considered to be low and the value and sensitivity of nearby
agricultural land is also low to medium. Where there is a potential for the spread of the weed,
such an impact is readily reversible in the short-term. It is both a legal requirement and
standard construction good practice to implement prevention and control measures to avoid
the establishment and spread of invasive and noxious weed species. Such measures will be
undertaken during the construction works to ensure that the potential for the establishment of
invasive and noxious weed species is minimised.
v) Impacts on Agri-Environment Schemes
12.5.26 The development will affect land currently under agri-environment schemes (comprising Entry
Level Environmental Stewardship and Countryside Stewardship Schemes). Implementation of
the Schemes within the Development Site will cease during the preparatory works and
construction phase. This change is not assessed as an impact as the land required for the
development will be taken out of agricultural production. Any environmental or ecological
benefits impacted by the change to land use are addressed in Chapter 18 on terrestrial ecology.
vi) Common Land
12.5.27 The two small areas of Common Land that lie outside the Development Site will not be impacted
by the proposed development.
b)
Mitigation Measures during the Construction Phase
12.5.28 The permanent loss of agricultural land will be minimised as far as practicable on-site through
the layout and location of construction phase related works including temporary access roads,
compounds etc. No specific mitigation is required with regard to loss of farm units, as purchase
of land for development has taken place by agreement with relevant land owners.
12.5.29 The Landscape Restoration Plan for the Development Site (see Chapter 2, Volume 2) includes
measures for the restoration of part of the Hinkley Point C Development Site back to agricultural
use and this will offset some of the total loss of agricultural land that would result from the
development. Measures would be undertaken (see below) to ensure that the conditions for
reinstatement to agricultural use are provided (e.g. adequate soil productivity, suitable
drainage of land).
12.5.30 Good practice regarding soil removal and reinstatement requires that soils should be returned
as closely as possible to their original state after disturbance and this good practice would be
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complied with throughout the development. Appropriate reinstatement techniques mean that
site restoration establishes more quickly and is sustained. It will not be possible to reinstate all
soils within the development area, as large areas will be occupied by new build, hardstanding
and a range of structures associated with the proposed development. Soils will be re-used onsite wherever it is practicable to do so.
12.5.31 The proposed mitigation in relation to impacts on soil resources and current land uses during
the construction phase includes development of restoration plans for temporarily required
construction areas to restore land use, and soils handling and management programmes to
preserve surface soils.
12.5.32 Adverse impacts on the integrity of soils and soil structure, and hence on future agricultural
potential of soils, will be reduced by implementing a soil handling strategy and Soil
Management Plan during the construction phase. This will include procedures for stripping,
handling, transporting, storing, and reinstatement or re-use of soils so as to maintain soil
viability and biological activity. The Soil Management Plan will include procedures for soil
stripping, handling, transporting, storing, and reinstatement (or re-use) of soils so as to
maintain, as far as practicable, soil viability and biological activity. The Soil Management Plan
will follow Defra’s Code of Practice on Sustainable Soils (Ref. 12.13) and will comply with the
MAFF Good Practice Guide for Handling Soils by Machine (2000) (Ref. 12.14). It will also
include procedures for the separation of topsoil and subsoil and for the height and slopes of
storage mounds to maintain soil viability.
12.5.33 The works will be phased to ensure that soils are stripped in each compartment of the site
ahead of earthworks activities, and access routes and working areas will be clearly delimited to
ensure that soil compaction on areas not directly involved in the works will be avoided. This
will minimise the total area impacted and will as far as possible protect soil structure so that
stripped soils can be used in later restoration and landscaping programmes. There will be an
associated written procedure and paper trail for each compartment and associated stockpile
which will address:




soil type and compartment identifier/location;
stockpile location, identifier and height;
stripping and handling method employed (noting any special conditions or measures used
in stripping or stockpiling, such as preliminary drying or under-drainage); and
planned and actual reinstatement or re-use.
12.5.34 Separate stockpiles will comprise topsoil, suitable soil materials, unsuitable soil materials and
rock. Documentation and control measures will be set in place to prevent accidental mixing
and ensure soils are segregated according to source compartment and eventual reuse. Suitable
soil materials include those that can be re-used as excavation fill, and those that are defined as
unsuitable and cannot be re-used in this way. Topsoil will be separated in accordance with its
value for planting and agricultural re-use. Stockpile stabilisation and integrity will be based on
the landscape restoration plan. Stockpiles will be seeded with a neutral grassland seed mix to
maintain slope stability and to prevent erosion or dust generation. Stockpiles will be managed
and monitored throughout their lifetime.
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12.5.35 Written records will be kept and be available for inspection. The method adopted for soil
stripping will be defined in relation to the compartment on-site, and may vary depending on the
soil type and/or weather conditions. Tool Box talks will be used to ensure all site staff are
aware of the Soil Management Plan and applicable procures. The Tool Box Talks will be based
on guidance provided by Defra.
12.5.36 The Soil Management Plan will include measures to be implemented during site restoration to
ensure soil quality and integrity is maintained during the process of handling and transporting
soils and their replacement. This will include matching documented stockpiles to appropriate
areas of reinstatement, defined movement routes for vehicles and machinery to minimise
tracking over replaced soils and specific measures for grading and final restoration of soils.
12.5.37 Measures to prevent compaction, erosion and dust generation will also be set in place.
Disturbance and dust generation during earthworks and construction and possible off-site
impacts will be avoided or mitigated through a series of specific construction control measures.
These are more fully described in the Chapters on Air Quality and Hydrology and will form part of
the Construction Environmental Management Plan (CEMP)
12.5.38 Excavated topsoils will be re-used in the landscaping around buildings and the making good of
the surrounding area where practicable. Excavated subsoil material will be re-used as fill where
it is of suitable quality or potentially as nutrient-poor substrates for the creation of species-rich
grassland habitats.
12.5.39 Soil compaction on areas not directly involved in the construction process will be avoided
where possible to minimise the total area impacted by earthworks and to aid later restoration
and landscaping.
12.5.40 Procedures will be implemented as part of the CEMP to ensure appropriate biosecurity (disease
and pest control) and weed control to protect both on-site soils and adjacent land holdings.
Standard procedures will be developed in line with published Defra and Environment Agency
guidance to control the spread of invasive/alien plants or disease.
12.5.41 Disruption to adjacent farm units/holdings and existing or planned land management will be
minimised. Contingency measures will be an integral part of the CEMP. Control measures in the
CEMP will protect crops and other vegetation, fences and livestock on adjacent land holdings
from potential impacts.
12.5.42 The land drain system will be re-aligned and reinstated as necessary to ensure adjacent land
drainage or soil quality and cropping success is not adversely affected by the
construction/operation of the Development Site. Pre and post construction drainage
management features will be installed to maintain the integrity of the existing system across
adjoining land. This will be designed to ensure the long term operation of the drainage system
post construction.
12.5.43 Site runoff will be controlled, intercepted and treated where necessary before it reaches
ditches, watercourses and adjacent land. Site drainage management will be implemented
during both the construction and operational phases in agreement with the Environment
Agency.
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12.5.44 In the unlikely event that any unrecorded animal burial pit(s) is/are encountered then the
construction works in that area will be stopped immediately, any carcases exposed, re-covered
and the area cordoned off. The Animal Health Division of Defra will be consulted, their advice
taken, and appropriate action for the testing, treatment and disposal of any remains agreed.
c)
Operational Impacts
12.5.45 The changes to land use and soils occurring during the construction phase (such as land take
and loss of cropping areas) will remain through the operational phase of the project and
therefore any impacts will be long term. No further impacts on soils and land use beyond those
caused during construction are expected to occur during operation.
12.5.46 Normal operation of the development will not prevent continued agricultural activity in adjacent
areas beyond the boundary of the operational site. As for the construction phase, the
magnitude of possible impacts on off-site soils and land use during the operational phase is
considered to be low, assuming that standard good practice measures are in place to manage
on and off-site drainage and to prevent pollution from on-site storage of materials (see Section
12.6 below).
12.5.47 The operational phase is considered to have no or a negligible impact on soils and land use are
likely during the operational stage, nor any additional impacts to those identified during the
construction phase with standard good practice site operation and controls in place. Hence no
specific mitigation measures are identified here.
12.6
Residual Impacts
12.6.1
Residual impacts relating to land use and soils during the construction phase are predicted to
be of no greater significance than minor adverse with mitigation measures in place. These
mainly relate to impacts on soils within the construction areas due to the scale of soil stripping,
movement and storage necessary and the duration of storage required over the construction
period. A Soil Management Plan as part of the CEMP will ensure that residual impacts are
acceptably small.
12.6.2
No or negligible residual impacts to land use and soils are predicted during the operational
phase, as none of the operational activities will have any impact over and above those which
occur and are mitigated for during the construction phase.
12.6.3
Table 12.5 is a summary of assessed impacts, mitigation measures and residual impacts. No
mitigation is required where impacts are assessed as less than moderate or major (i.e. as minor
or negligible significance). Where relevant, standard good practice measures are referred to
provides that will be set in place as part of the CEMP.
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Table 12.5: Summary of Assessed Impacts, Mitigation Measures and Residual Impacts
Receptor
Potential Impact
Potential
Magnitude
Description
Value/~
Sensitivity
Significance
Proposed
Mitigation
Residual
Impact
Assessment
(after
mitigation)
Agricultural land resource
Land take for
construction. Loss or
degradation of soils
mainly Subgrade 3b,
some Subgrade 3a and
Grade 4
Low
Site Specific
Direct
Adverse
Permanent
Temporary
Low/
Medium
Minor
Soil Management Plan as
part of CEMP
Minor
Restoration to
agricultural use of some
land within the Hinkley
Point C Development Site
in line with the
Restoration Plan
Reuse and reinstatement
of soils in line with Site
Restoration Plan
ALC or agricultural land
quality (agricultural potential)
– outside study area
Disturbance/dust/runoff impact on adjoining
land
Very Low
Indirect
Adverse
Permanent
Temporary
Low/
Medium
Negligible/
Minor
None proposed
Negligible
Soils – on-site within study
area
Damage to soil
quality/profiles due to
construction disturbance
during topsoil stripping
and stockpiling, site
levelling and terracing
Medium
Site specific
Direct
Adverse
Temporary
Permanent
Medium/
High
Moderate
Soil Management Plan as
part of CEMP
Minor
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Reuse and reinstatement
of soils in line with Site
Restoration Plan
12 Soils and Land Use
Receptor
Potential Impact
Potential
Magnitude
Description
Value/~
Sensitivity
Significance
Proposed
Mitigation
Residual
Impact
Assessment
(after
mitigation)
Noxious weeds and diseases
Spread of noxious weeds
and diseases (on-site
and off-site)
Low
Direct
Indirect
Adverse
Temporary
Low
Minor
No specific mitigation
required. As standard
good practice, instigate
MAFF procedures for the
control of soil transfer
and consult Defra
implement guidance.
Minor
Animal health
Disturbance of old
animal burial pits
Very Low
Site Specific
Direct
Adverse
Temporary
High
Minor
No specific mitigation
required. As standard
good practice, include
contingency measure in
CEMP to contact Defra
Animal Health Division if
previously undiscovered
pit encountered
Minor
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References
12.1
Wildlife and Countryside Act (1981) (as amended).
12.2
The Environmental Stewardship (England) and Countryside Stewardship (Amendment)
Regulations 2006. ISBN 011074439X.
12.3
Planning Policy Statement (PPS) 7 ‘Sustainable Development in Rural Areas', issued by the Office
of the Deputy Prime Minister (ODPM, now Communities and Local Government).
12.4
Defra (31 March 2008): Soil Strategy for England (Draft). West Somerset District Council.
12.5
The West Somerset District Local Plan (2006).
12.6
Soil Survey of England and Wales (1984) Soils and Their Use in South West England. SSEW
Bulletin No 14, and associated Map Sheet No 5.
12.7
Findlay, D.C. 1965. The Soils of the Mendip District of Somerset. Memoir of the Soil Survey of
Great Britain, Harpenden.
12.8
Groundsure Report.
12.9
West Hinkley Wind Farm Environmental Statement, (October 2006).
12.10 Hinkley Point A Environmental Statement (2000).
12.11 Hinkley Point C Environmental Statement (1987).
12.12 MAFF (1988) Agricultural Land Classification of England and Wales. Revised guidelines and
criteria for grading the quality of agricultural land.
12.13 Defra Code of Practice on Sustainable Soils on Construction Sites (2009).
12.14 MAFF Good Practice Guide for Handling Soils by Machine (2000).
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