7 Geology, Contaminated Land and Groundwater 7.1 Introduction 7.2 Approach and Methods 7.3 Baseline Conditions 7.4 Potential Impacts 7.5 Potential Mitigation 7.6 Summary of Route Corridor Options Assessment 7.7 Scope of Stage 3 Assessment 7.8 References

7 Geology, Contaminated Land and Groundwater

7.1 Introduction

7.1.1 This chapter presents the assessment of the Stage 2 route corridor options for the Forth Replacement Crossing in terms of geology, groundwater and contaminated land issues.

7.1.2 There are a variety of ways in which road developments can impact on geological resources. Excavating or masking exposures of rocks or superficial geological deposits of specific scientific interest can represent a serious impact if the features of interest are not reproduced elsewhere in the area. Impacts can also affect the existing or the potential commercial exploitation of resources. Road schemes can also have potential impacts on underlying groundwater aquifers both during construction and operation. For example, construction works involving excavation can lead to dewatering of shallow aquifers. There is also a risk of spillage or leakage of fuel or oil from storage tanks or construction plant. Without suitable mitigation measures, these pollutants can enter the aquifers. Once a new road is opened, runoff from the surface may contain elevated concentrations of pollutants such as oils, suspended solids, metals (e.g. copper and zinc) and, in winter, salt and engine coolants (e.g. ethylene glycol). Ground conditions can also impose constraints on a proposed road scheme, for example, where land has become unstable due to mining or has been contaminated by previous land uses.

7.1.3 This chapter presents the following:

• baseline conditions within the route corridors relating to solid and drift geology, mineral extraction, contaminated land, groundwater and location of private water supplies;
• potential impacts of each route corridor option with regard to the identified baseline conditions;
• outline or anticipated mitigation measures that might be developed at DMRB Stage 3 of a preferred option; and
• a summary of the route corridor option assessment identifying residual impacts and taking into account likely mitigation.

7.1.4 This assessment has been undertaken using the guidance contained in DMRB Volume 11 ‘Geology and Soils’ (The Highways Agency et al., 1993), taking into account updated guidance on contaminated land risk assessment where appropriate. With the exception of contaminated land, impacts on soils are not assessed in detail in this chapter. The principal issue with regard to soils is deterioration of agricultural soil quality due to disturbance at construction stage (and subsequent storage/reuse). Measures to address this are considered in the context of agricultural land capability in Chapter 17 (Disruption Due to Construction).

7.2 Approach and Methods

7.2.1 The assessment covers a wide study area as shown on Figure 5.1 and described in Chapter 5. Figure 7.1 (Contaminated Land), Figure 7.2 (Geological Constraints) and Figure 7.3 (Hydrogeological Constraints) present the information used for this assessment.

7.2.2 The assessment has been undertaken for the following aspects of ground conditions:

• solid and drift geology;
• features of geological and geomorphological importance;
• mineral extraction and reserves;
• contaminated land;
• groundwater environment; and
• private water supplies.

Baseline Conditions

7.2.3 Baseline conditions were determined though a desk-based assessment, field surveys and consultation with statutory and non-statutory bodies.

Desk-based Assessmentf

7.2.4 The desk-based assessment included a review of the following information:

• British Geological Society (BGS) data including BGS Drift and Solid Geological Maps, BGS borehole logs, BGS Hydrogeological and Groundwater Vulnerability Maps;
• Department of Environment Industrial Profiles and Contaminated Land Report (CLR) 8 (DEFRA, 2002) to identify the character of potentially contaminated land;
• Ordnance Survey (OS) historical maps dating back to 1856 for information on former land use, any potential contamination and physical hazards and information on private water supplies;
• SEPA Groundwater Vulnerability Maps;
• Scottish National Heritage designation database (SNH, 2008);
• previous reports commissioned by Fife Council in the St. Margaret’s Marsh area for information on previous land use in the area (Envirocentre, 2003; Envirocentre, 2004); and
• results of previous studies including the Forth Replacement Study Initial Desk Study Report December 2007 (Jacobs/AECOM/Faber Maunsell, 2007).

Field Surveys

7.2.5 Field surveys were undertaken at targeted locations along the route corridors, based on the findings of the desk-based assessment. The surveys undertaken include:

• Contaminated land site reconnaissance to identify any additional areas of potential contaminated land and to clarify current land use as identified from historical maps.
• Geological site reconnaissance to identify any potential areas of geological/geomorphological importance and identify any in-filled quarry areas.
• Hydrogeological survey to gather information relating to sensitive areas potentially supplied by groundwater within the vicinity of the proposed options and to record any features that may provide further information with regard to the importance of the quality and supply of groundwater in these areas.

Consultations

7.2.6 Consultations were undertaken with a number of statutory and non-statutory bodies in Scotland in order to assess geological and hydrogeological impacts and contaminated land. These include the following:

• Coal Authority for information on past, current and potential future mine workings within the route corridor and how they may affect future development;
• Fife Council, City of Edinburgh Council and West Lothian Council for information on former contaminated land use, Part IIA determinations, private water supplies, licensed fuel storage and any additional relevant information;
• BGS for information regarding the nature of geology and hydrogeology in the near vicinity of the proposed route corridor options;
• SEPA and SNH for information on the location and extent of environmental or historical sensitivities in the vicinity of the proposed route corridor options and to establish any future development constraints; and
• local groups for information on any existing private water supplies (PWS).

Impact Assessment

7.2.7 As described below, significance of impacts on geology/geomorphology and contaminated land were assessed taking into account receptor sensitivity and impact magnitude.

7.2.8 Specific sensitivity and impact magnitude criteria are not defined for the assessment of mineral extraction or contaminated land as these aspects primarily represent engineering considerations for the scheme construction. However, the occurrence and proposed management of these aspects has been considered, assessed qualitatively, and presented as part of this assessment.

Solid and Drift Geology

7.2.9 For the purposes of this assessment, the sensitivity of geological features of interest within the study area is taken to include solid and drift geology including geomorphological interest. Assessment of the impact of route corridor options was undertaken by applying the sensitivity and magnitude criteria given in Table 7.1 and Table 7.2 below. The impact significance was then determined using Table 7.3.

Table 7.1: Sensitivity Criteria - Geological Features

Sensitivity	Description
High	Areas containing geological or geomorphological features considered to be of national interest. e.g. Sites of Special Scientific Interest (SSSIs).
Medium	Areas containing features of designated regional importance considered worthy of protection for their educational, research, historic or aesthetic importance. e.g. Regionally Important Geological Sites (RIGS).
Low	Features not currently protected but that may require specific protection in the future.
Negligible	Features not currently protected and unlikely to require specific protection in the future.

Table 7.2: Magnitude Criteria - Geology

Magnitude	Description
High	Partial (greater than 50%) or total loss of a site, or where there would be complete severance of a site such as to affect the value of the site.
Medium	Loss of part (between approximately 15% and 50%) of a site, major severance, major effects to the setting, or disturbance such that the value of the site would be affected, but not to a major degree.
Low	Minimal effect on a site (up to 15%) or a medium effect on its setting, or where there would be a minor severance or disturbance such that the value of the site would not be affected.
Negligible	Very slight change from baseline condition. Change hardly discernible, approximating to ‘no change’ conditions.

Table 7.3: Matrix for Determination of Impact Significance – Geology

Sensitivity / Magnitude	Negligible	Low	Medium	High
High	Slight	Moderate	Moderate/ Substantial	Substantial
Medium	Negligible/ slight	Slight/Moderate	Moderate	Moderate/ Substantial
Low	Negligible	Negligible/Slight	Slight/Moderate	Moderate
Negligible	Negligible	Negligible	Negligible/Slight	Slight

Mineral Extraction

7.2.10 At DMRB Stage 2, potential areas of mineral resources and mineral extraction are identified. However, these aspects primarily represent engineering considerations for the scheme construction and their extent, nature and required mitigation can only be assessed fully by intrusive site investigation, which will be undertaken prior to detailed design.

Contaminated Land

7.2.11 This assessment focuses on the potential for impacts on receptors as a consequence of encountering contaminated land (including construction workers), using a conceptual site model (CSM). The CSM represents a network of relationships between potential hazards from within and adjacent to the site area and the receptors that may be exposed to the hazards through linking pathways. The CSM eliminates those pathways that are incomplete and therefore cannot pose a risk, and where complete potential pollutant linkages exist, a qualitative risk assessment is undertaken. For the qualitative risk assessment, the term ’sensitivity’ is not appropriate and the ‘likelihood’ of a complete pollutant linkage being present is considered.

7.2.12 The likelihood of a complete pollutant linkage being present is defined in CIRIA 552 (CIRIA, 2001) and summarised in Table 7.4 and the magnitude, or ‘consequence’, of the effect of contaminated land on likely receptors is outlined in Table 7.5. The qualitative risk assessment of potential risk to receptors posed by contaminated land was then undertaken by determining the probability of a complete pollutant linkage being present and the potential consequences, with reference to the matrix detailed in Table 7.6.

Table 7.4: Likelihood Criteria – Contaminated Land

Likelihood	Definition
High likelihood	There is a pollution linkage and an event that either appears very likely in the short term and almost inevitable over the long term, or there is evidence at the receptor of harm or pollution.
Likely	There is a pollution linkage and all the elements are present and in the right place, which means that it is probable that an event will occur. Circumstances are such that an event is not inevitable, but possible in the short term and likely over a long term.
Low likelihood	There is a pollution linkage and the circumstances are possible under which and event could occur. However, it is by no means certain that even over a longer period such an event would take place, and is less likely in the shorter term.
Unlikely	There is a pollution linkage but circumstances are such that it is improbable that an event would occur even in the very long term.

Table 7.5: Magnitude (Consequence) Criteria – Contaminated Land

Magnitude	Definition
Severe	Short-term (acute) damage to human health (significant harm). Pollution of sensitive water resources as a result of short-term exposure. Catastrophic damage to buildings/property. Damage to a particular ecosystem as a result of acute exposure.
Medium	Chronic damage to human health (significant harm). Pollution of sensitive water resources. A significant change in a particular ecosystem, or organism forming part of such an ecosystem.
Mild	Pollution of non-sensitive water resources. Significant damage to crops, buildings, structures and services. Damage to sensitive buildings/structures/services or the environment.
Minor	Harm (not necessarily significant), which may result in financial loss or expenditure to resolve. Non-permanent health affects to human health. Easily repairable damage to buildings, structures and services.

Table 7.6: Matrix for Determination of Qualitative Risk Assessment: Contaminated Land

Likelihood / Consequence	Unlikely	Low likelihood	Likely	High likelihood
Severe	Moderate	Moderate	High	Very high
Medium	Low	Moderate/low	Moderate	High
Mild	Very low	Low	Moderate/low	Moderate
Minor	Very low	Very low	Low	Moderate/low

Groundwater

7.2.13 DMRB Stage 2 assessment considers groundwater sensitivity in the context of hydrogeological conditions including aquifer resources, and on the proximity of private water supplies where known. Subsequent assessment at Stage 3 will utilise more detailed information on groundwater conditions (i.e. groundwater levels) and on private water supplies (e.g. depth of water level and total depth of well, density of private water supplies).

7.2.14 Assessment of the impact of route corridor options was undertaken by applying the sensitivity and magnitude criteria given in Table 7.7 and Table 7.8 below. The impact significance was then determined using the same matrix as for geology/geomorphology (Table 7.3).

Table 7.7: Sensitivity Criteria - Groundwater (Including Private Water Supplies)

Sensitivity	Description
High	1) Local aquifer(s) constitutes a valuable resource because of its high quality and yield, or extensive exploitation for public, private domestic, agricultural and/or industrial supply. 2) Private water supply positions close to the route corridor option (<100m) and highly vulnerable to any modification of hydrogeological condition in the vicinity of the supply.
Medium	1) Local aquifer(s) of limited value because quality does not allow potable or other quality sensitive uses. Exploitation of local groundwater is not extensive. 2) Private water supply positions at medium distance from the route corridor option (100-500m) and moderately vulnerable to modification of hydrogeological conditions along the nearest area of the route corridor option.
Low	1) Poor groundwater quality and/or very low permeability make exploitation of the aquifer(s) unfeasible. 2) Private water supply positions at approximately 500-800m from the route corridor option and slightly vulnerable to modification of hydrogeological condition along the nearest section of route corridor option.
Negligible	Private water supply is abandoned or not used or at greater than approximately 800m from the route corridor option.

Table 7.8: Magnitude Criteria - Groundwater

Magnitude	Description
High	Major permanent or long-term change to groundwater quality or available yield. Existing resource use is irreparably impacted upon. Changes to quality or water table level would have an impact upon local ecology.
Medium	Changes to the local groundwater regime are predicted to have a slight impact on resource use. Minor impacts on local ecology may result.
Low	Changes to groundwater quality, levels or yields do not represent a risk to existing resource use or ecology.
Negligible	Very slight change from groundwater baseline conditions approximating to a ‘no change’ situation.

Table 7.9: Matrix for Determination of Impact Significance – Geology

Sensitivity / Magnitude	Negligible	Low	Medium	High
High	Slight	Moderate	Moderate/ Substantial	Substantial
Medium	Negligible/ slight	Slight/Moderate	Moderate	Moderate/ Substantial
Low	Negligible	Negligible/Slight	Slight/Moderate	Moderate
Negligible	Negligible	Negligible	Negligible/Slight	Slight

Limitations to Assessment

7.2.15 Limitations to this assessment are as follows:

• The extent and quantum of land contamination cannot be determined from desk based studies and site walk-overs. Whilst these processes identify and inform an evaluation of the potential for contamination, the nature, extent, severity and location of soil and groundwater contamination cannot be determined without intrusive site investigation and the chemical analysis of samples of soil and groundwater collected at the location.
• The accuracy and level of detail of documented sources. For example, the identification of potential contamination sources relies on the accuracy of historical mapping.
• The scale and information contained in the Hydrogeological and Groundwater Vulnerability Map of Scotland mean that the characterisation of the baseline conditions, and hence a detailed analysis of the potential impacts, is limited at this stage. Detailed site investigations and further PWS consultation will be available in the future before the detailed design of the preferred option and the hydrogeological assessment will be updated accordingly.
• Available private water supplies information is presented within this chapter. However, it should be noted that this will be augmented at Stage 3 by detailed landowner consultation, and as such the exact location of some springs and wells is currently not known.

7.2.16 The above limitations are typical of Stage 2 assessment, and the assessment reported in this chapter is considered robust and of an appropriate level of detail and in line with the DMRB guidance.

7.3 Baseline Conditions

7.3.1 This section describes the baseline conditions identified through the collection and review of information from existing sources, additional survey work and consultation responses.

Solid and Drift Geology

7.3.2 Information on geology and on geological/geomorphological features of importance has been sourced from relevant BGS geological maps (BGS, 1962 to 1994), SNH databases (2008) and previous desk study reports (Jacobs et al., 2007).

Firth of Forth

7.3.3 The bridge corridor starts at the southern shore to the west of the Port Edgar Marina and crosses gently sloping tidal flats for a distance of about 500m at which point the river bed falls more steeply at a gradient of about 1 in 8 at the southern edge of the main channel reaching a level of about -45m above Ordnance Datum (aOD). The river bed rises steeply at Beamer Rock which reaches an elevation of about +3m aOD close to the existing lighthouse. The area of rock exposed varies with the tide reaching about 45m by 95m at low water springs. The bathymetric surveys have shown that the south and east sides of Beamer rock are extremely steep with near vertical faces. The north edge is less steep with gradients of around 1:1 reported.

7.3.4 To the north of Beamer Rock the river bed falls to about -33m aOD at the north channel. The bed level then rises northwards to the Rosyth Channel which is dredged to a depth of -12 to -16m aOD. The north margin of this channel rises at a gradient of about 1 in 10 towards the more gently sloping north foreshore which extends for about 300m towards the northern landfall of the crossing corridor to the east of Cult Ness.

7.3.5 Rock outcrops at the surface at Beamer Rock but elsewhere the bedrock is generally overlain by alluvial and glacial deposits. These form a complex sequence of fine grained and granular deposits which increase in thickness at the southern and northern margins of the deep channels to 25 to 30m within the limits investigated. The upper part of these deposits is typically of very soft or loose consistency. The 1993 ’Setting Forth‘ study (Scottish Office Development Department, 1996) investigations indicate that rockhead falls to about -35m aOD at the preliminary location of the north tower and about -50m aOD at the preliminary location of the south tower (based on extrapolation of the geophysical survey which was affected by acoustic masking in this area).

7.3.6 The ground investigations carried out as part of the ‘Setting Forth’ study (Scottish Office Development Department, 1996) revealed frequent dolerite intrusions up to a few metres thick within the West Lothian Oil Shale Formation rocks to the south of Beamer Rock whilst to the north of Beamer Rock, layers of tuff were found.

7.3.7 The Admiralty Chart Sheet 736 shows a ‘spoil ground’ immediately upstream of Beamer Rock.

7.3.8 No areas of geological/geomorphological importance were identified within the Firth of Forth.

Northern Study Area

7.3.9 The solid geology beneath the study area consists of sedimentary rocks of the Carboniferous Lower Limestone Group (LLG) and Strathclyde Group (SG), comprising inter-bedded sandstones, siltstones, mudstones and limestones with mainly thin coal seams (limestone, coal and mudstone have been known to be worked locally). Towards the southern section of the route corridor, (possibly Permian) igneous rocks comprising quartz dolerite are present. The east-west trending Rosyth Fault crosses the approximate northerly mid point of the route corridor; igneous rocks and rocks of the SG are predominantly present to the south of the Rosyth Fault, while rocks of the LLG are predominantly present to the north.

7.3.10 The superficial deposits present beneath the route corridor include made ground, late glacial raised marine deposits, raised beach, lake deposits and glacial till.

7.3.11 Made ground is indicated at the following locations, which are shown on Figure 7.1:

• St Margaret’s Marsh, reclaimed land which may be variable in composition, and may include compressible material;
• industrial areas in the vicinity of Belleknowes Industrial Estate including a back-filled clay pit adjacent to the former brick and tile works; and
• embankments associated with the existing road and railway network.

7.3.12 The late-glacial raised marine deposits and lake deposits located in the vicinity of Rosyth, and in the southern part of Masterton Junction, are recorded as comprising mainly clay, with inter-bedded silt and sand bands. A buried channel feature, trending east to west, is recorded in this area, with superficial deposits in excess of 30m recorded in the published geological data.

7.3.13 The raised beach deposits, located to the west of Masterton Junction are described as comprising mainly loose to medium dense, occasional dense, sands and gravels, and may include very clayey and silty horizons with some cobbles.

7.3.14 The glacial till in this area is recorded as comprising a firm to stiff, becoming very stiff sandy silty clay with fine to coarse gravel and occasional cobbles and boulders. This deposit extends over much of the northern part of the study area, between Masterton and Halbeath, and also occurs between the rock exposures near Castlandhill.

7.3.15 A number of areas of geological/geomorphological importance have been identified within the study area and are listed in Table 7.10 and illustrated on Figure 7.2 (Geological Constraints).

Table 7.10: Geological Features of Importance in the Northern Study Area

Area Name	Designation	Cited Feature	Aspect of Geological Relevance
St. Margaret’s Marsh	SSSI	Salt Marsh	Littoral sediment (Coast)
Ferry Hills	SSSI	Carboniferous-Permian Igneous	Igneous petrology
Firth of Forth	SSSI	Carboniferous-Permian Igneous	Igneous petrology
		Coastal Geomorphology of Scotland	Geomorphology

Southern Study Area

7.3.16 The majority of the solid geology beneath the study area consists of Lower Carboniferous sedimentary rocks of the Upper and Lower Oil Shale Groups, which mainly comprise sandstones and marls, with shale, oil/bituminous shale and occasional limestone beds. Igneous intrusive rocks comprising teshcenite, also of Lower Carboniferous age, are present within some areas, particularly at the coastline towards the north of the study area.

7.3.17 The superficial deposits present beneath the route corridor include made ground, alluvium, raised beach deposits and glacial till:

• made ground is located at embankments associated with the existing road and railway network;
• small areas of undifferentiated alluvium are recorded in association with Humbie Reservoir;
• raised beach deposits are located in a thin strip parallel to the shoreline, and are described as comprising mainly loose to medium dense, occasional dense, sands and gravels, and may include very clayey and silty horizons and some cobbles; and
• glacial till covers the majority of the study area and is described as very uniform in characteristic and in excess of 20m thick in places.

7.3.18 A number of areas of geological/geomorphological importance have been identified within the study area and are listed in Table 7.11 and illustrated on Figure 7.2 (Geological Constraints).

Table 7.11: Geological Features of Importance in the Southern Study Area

Area Name	Designation	Feature	Category
Firth of Forth	SSSI	Carboniferous-Permian Igneous	Igneous petrology
		Coastal Geomorphology of Scotland	Geomorphology

Mineral Extraction

Firth of Forth

7.3.19 Although coal reserves exist in this area, Coal Authority records (Coal Authority, 2008) state that the Firth of Forth is not within an area which is likely to be influenced by past or present underground or open cast coal mining and associated workings. In addition, the Firth of Forth is not within an area for which the Coal Authority has granted, or is determining whether to grant, a licence to remove coal using underground workings.

Northern Study Area

7.3.20 Historical pits and quarries have been identified following a review of historical maps (1856 - 2007). The quarries noted within the Northern study area are listed in Table 7.12.

Table 7.12: Mineral Extraction Northern Study Area

Name	Grid Reference	Dates Marked on OS Maps
Old Quarry	NT 12550 80700	1896-1915
Quarry	NT 12580 80650	1915-1927
St. Margaret’s Quarry	NT 12650 81000	1896-1927 (1961 marked disused)
Quarry	NT 12680 81240	1915-1961
Welldean Quarry	NT 12560 81240	1856;1896 (Disused); 1915-1927 (Quarry); 1916 (pond)
Old Quarry	NT 12310 81910	1896-1927 (marked as stone from 1961-current day)
Old Quarry (whinstone)	NT 12310 81870	1856-1927 (marked as stone from 1961-current day)
Ferry Toll Quarry	NT 12630 81550	1896-1927 (marked disused from 1961 to current day)
Castlelandhill Quarry	NT 11990 82290	1915-1927 (1961-1967 marked disused and small pond)
Old Quarry	NT 12480 82670	1896
Old Quarry	NT 12510 82890	1896-current
Old Quarry	NT 12430 83450	1915-1926
Fairykirk Quarry	NT 12460 83380	1951-current
Gravel Pit	NT 13260 84750	1915-1966
Old Quarry	NT 13400 84700	1915
Dulloch Quarries (limestone)	NT 13300 86600	1896-1927 (1965-current marked as ponds)

7.3.21 According to Coal Authority records (Coal Authority, 2008b, 2008c, 2008d, 2008e), the Northern study area does not lie within an area which is likely to be influenced by past or present underground coal workings. However, coal is believed to be at or close to the surface in the Halbeath, Masterton and Inverkeithing areas and may have been worked at some time in the past.

7.3.22 The Northern study area is not within an area for which the Coal Authority has granted, or is determining whether to grant, a licence to remove coal using underground workings. However, coal is known to exist in the Halbeath, Masterton and Inverkeithing areas and these deposits may be worked some time in the future.

7.3.23 The Northern study area does not lie within the boundaries of any present or likely future open cast coal mines. The Halbeath and Masterton areas lie within the boundary of a past opencast site, the details of which are unknown.

7.3.24 There is no record of mine gas emissions requiring action by the Coal Authority within the Northern study area.

Southern Study Area

7.3.25 Historical pits and quarries have been identified following a review of historical maps (Ordnance Survey, 1853-2007). The quarries noted within the Southern study area are listed in Table 7.13 and illustrated on Figure 7.1c.

Table 7.13: Mineral Extraction Southern Study Area

Name	Grid Reference	Dates Marked on OS Maps
Old Quarries	NT 11760 78500	1896-1916
Old Quarry	NT 11250 74270	1855-present day
Quarry	NT 10900 77880	1856-1915(1964 refuse tip)

7.3.26 According to Coal Authority records (Coal Authority, 2008f, 2008g, 2008h, 2008i), the Dalmeny and South Queensferry areas of the Southern study area are in the likely zone of influence from workings in three seams of oil shale at shallow to 320m depth which were last worked in 1901. Nine disused mine shafts and adits associated with this oil shale have been identified by the Coal Authority.

7.3.27 The Coal Authority Report (2008f, 2008g, 2008h, 2008i) indicates that coal may exist at or close to the surface in the Dalmeny and South Queensferry areas and that this coal may have been worked in the past.

7.3.28 The Southern study area is not within an area for which the Coal Authority has granted, or is determining whether to grant, a licence to remove coal using underground workings. However, coal is known to exist in the Dalmeny and South Queensferry areas and these deposits may be worked some time in the future.

7.3.29 The Southern study area does not lie within the boundaries of any past, present or likely future open cast coal mines.

Contaminated Land

Firth of Forth

7.3.30 The Firth of Forth has been dredged extensively throughout the course of the twentieth century to ensure the free passage of shipping to Rosyth and Grangemouth. Extensive dredging has been undertaken by the Navy during the development of Port Edgar and Rosyth with approximately three million cubic metres of material removed from the sea bed at Rosyth alone (Jacobs et. al.,2007).

Northern Study Area

7.3.31 Features and activities within the Northern study area with the potential for producing contaminated ground were identified through the examination of historical OS maps (Ordnance Survey, 1856- 2007) and site reconnaissance; the areas identified are presented on Figure 7.1 (Contaminated Land).

7.3.32 Large areas of the land within the Northern study area have undergone industrial development; the relevant areas are detailed in the following sections.

St. Margaret’s Marsh

7.3.33 St. Margaret’s Marsh is located on the north shore of the Firth of Forth, immediately west of the Forth Road Bridge (Figure 7.2b). This area originally comprised a natural inter-tidal zone, becoming artificially in-filled prior to the 1960s. The infill material is not known; however, it is likely to comprise marine sediments from the vicinity of the nearby Rosyth Naval Base. Low level radioactive waste has been historically discharged from the Rosyth Naval Base as part of nuclear submarine maintenance operations as part of a formal discharge consent. Monitoring data from the nearby inter-tidal zones suggest that radiation levels are not elevated above background; however, no data is available for the St. Margaret’s Marsh area and its presence cannot be completely discounted.

7.3.34 The eastern extent of St Margaret’s Marsh (St Margaret’s Bay) was used as a landfill between 1958 and 1972, receiving general / domestic waste. The fill thickness is indicated in reports supplied by Fife Council as being up to 2-3m, overlying marine clays (part of the reclaimed land). During previous investigations, elevated concentrations of methane were not identified; carbon dioxide was identified at concentrations of up to 1.7% v/v (volume of CO2 / total volume of gas) and risks to human health were identified from toxic metals at depths of greater than 1m below ground level (bgl). There is no evidence that suggests that monitoring is currently taking place and no venting system appears to have been installed. However based on the latest investigation results, it is understood that the landfill vented in the past via the monitoring boreholes, allowing gas concentrations to decrease in time.

7.3.35 A wastewater treatment works, constructed prior to the 1980s, is located within the northern area of St. Margaret’s Marsh (NT 12182 81612).

Belleknowes Industrial Estate and Surrounding Industrial Area

7.3.36 Both route corridor options either cross or run adjacent to the Belleknowes Industrial Estate shown on Figure 7.1a and b (approximate National Grid reference NT 12700 83700), which contains a former brick and tile works and clay pit, a Network Rail Sidings Depot, a scrap metal yard, a conservatory manufacturer and additional industrial units.

7.3.37 The Network Rail Discharge Sidings Depot has been in operation since approximately 1961. During a recent site visit, poor storage of materials and spillages of tars and oils was noted. In addition, an oily sheen was identified in the marsh area adjacent to the main railway sidings area.

7.3.38 The brick and tile works was operated up to approximately 1950 and used the natural clays adjacent to the works as production materials, thus forming the current pond area.

Refuse Tips

7.3.39 A number of refuse tips / landfills have been identified within the Northern study area and are listed in Table 7.14 and shown on Figure 7.1.

Table 7.14: Refuse Tips in the Northern Study Area

Grid Reference	Location	Historical Information
NT 12365 81380	Eastern portion of St. Margaret’s Marsh	Only marked on 1967 map. Additional information in paragraph 7.3.33.
NT 12710 81570	200m east of proposed route corridors, north of North Queensferry.	Marked on OS maps from 1980-1994
NT 12780 81400	200m east of proposed route corridors, north of North Queensferry.	Marked on OS maps from 1980-1987
NT 12580 83360	Adjacent to Fairy Kirk Quarry.	Marked on OS maps from 1957 to present day. Tips could not be identified during site visit.

7.3.40 Contaminants associated with historical landfill use may include heavy metals, asbestos and hydrocarbon contamination including polycyclic aromatic hydrocarbons (PAHs) and oil/fuel hydrocarbons.

Additional Potential Contamination Sources

7.3.41 Additional potential sources of contamination within the study area include:

• historical and current tanks located both on the route corridor and in the near vicinity of the route corridors (NT 12395 80995; NT 12900 84510; NT12010 81790; NT 13360 84010). No further information on the nature of these tanks was available at the time of this report;
• former railway lines and associated tunnels which cross the proposed route corridors which date from 1896;
• saltpans works and associated tanks present from 1896 to 1927 to the east of the route corridor options (NT 12660 82020);
• unnamed works from 1961 to present day located on route corridor (NT 13200 83780);
• electrical substation from 1982 to present day to the east of the route corridor options(NT 13520 84140);
• a cemetery to the east of the route corridor options (NT 12460 82270); and
• quarries and mineral extraction areas as detailed in paragraph 7.3.19.

Southern Study Area

7.3.42 Features and activities within the Southern study area with the potential for producing contaminated ground were identified through the examination of historical maps (Ordnance Survey, 1853-2007) and site reconnaissance; this is illustrated on Figure 7.1 (Contaminated Land).

7.3.43 The land areas in the Southern study area of the Forth Replacement Crossing have largely remained undeveloped, with the exception of the shore area, which is discussed below, and mainly consist of open land or cultivated fields.

Southern Shore Works Area

7.3.44 Part of the study area adjacent to the southern shore has been developed for industrial and residential purposes. The following areas where contamination may be present as a result of historic and current land uses have been identified:

• the sewerage pumping station, which has been present since 1993 to the east of the route corridor options (NT 11740 78640);
• dredging depot, in operation from 1915 to 1980, to the east of the route corridor (NT 11800 78670);
• stores area, which as been present from 1966, directly on route corridor with South Corridor Option 1 (NT 11700 78700); and
• Dundas Lime Works, marked only on the 1856 OS Maps to the east of the route corridor (NT 11740 78630).

Additional Features

7.3.45 The following additional areas of potential contamination have been identified:

• a refuse tip, in operation from 1973 to 1983, present to the north of Corridor Option 1 (NT 12300 77700);
• a refuse tip to the south of South Corridor Option 2, marked only on the 1973 OS Map (NT 11250 74270);
• unidentified storage tanks to the west of the route corridor (NT 10490 76440; NT 10720 76780). No further information on the nature of these tanks was available at the time of this report;
• land marked as a ‘Depot’ in 1967 and as a riding school (Westmuir Riding Centre) from 1977 to the present day (NT 10520 76460);
• an oil storage depot located to the east of South Corridor Option 1 and to the southeast of South Corridor Option 2 (NT 14570 76692);
• a slag heap, present from 1973, to the south of South Corridor Option 2 (NT 10100 74700); and
• disused oil shale mining shafts and adits within the Dalmeny area.

Groundwater

7.3.46 Information on groundwater has been gathered from the Hydrogeological Map of Scotland 1:625,000 (BGS, 1988d), the Groundwater Vulnerability Map of Scotland 1:625,000 (BGS, 1995), the Hydrogeological Map of Fife & Kinross scale 1:100,000 (1986) and SEPA’s consultation response.

7.3.47 Information provided by SEPA indicates that in the region there are two Drinking Water Zones related to groundwater. These have been identified as ‘South Fife bedrock and localised sand and gravel aquifers’ to the north of the Firth of Forth and ‘Edinburgh and Livingston bedrock and localised sand and gravel aquifers’ to the south of the Firth of Forth. Despite the different names these strata are expected to have similar hydrogeological characteristics to the north and the south of the Firth of Forth.

7.3.48 Consultation responses received at this stage have not indicated any public groundwater or surface water supply in the vicinity of the proposed route corridor options.

7.3.49 The Hydrogeological Map of Scotland (BGS, 1988) does not report any sand and gravel aquifer in the vicinity of the proposed route corridor options, although localised areas of sand and gravel (glaciofluvial deposits) are indicated on the geological maps to the eastern end of South Corridor Options 1 and 2, near to the River Almond (Southern study area, Figure 7.3i).

7.3.50 According to BGS (2004) alluvial deposits are locally classified as Intergranular High Productivity Drift Aquifers. Alluvial deposits occupy a significant area around the River Almond (Southern study area, Figure 7.3i) and may host important groundwater resources. However, such deposits will only be marginally affected by the proposed options and no groundwater supplies have been identified at this stage in this area.

7.3.51 BGS geological maps NT07NE, NT17NW, NT17SW, NT18NW and NT18SW have been used to refine the accuracy of the aquifer mapping as shown in the Hydrogeological Constraints Map (Figure 7.3). Figure 7.3 classifies the aquifers on the basis of their productivity and the presence of drift cover. The potentiality of the aquifer and the presence of superficial deposits with thickness greater than 1m are used as a simple tool to identify those areas that are more vulnerable to pollution.

7.3.52 The hydrogeological characteristics of the different geological units typical in the study area are summarised in Table 7.15.

7.3.53 Table 7.15 and Figure 7.3 indicate that groundwater in the region is of medium sensitivity because of the presence of potential private water supplies, although the information available to date suggests that the aquifers are not extensively exploited. Furthermore, groundwater in the region generally is not regarded as highly vulnerable to potential pollution because it is largely covered by drift deposits, which are usually of significant thickness and low permeability (e.g. till).

7.3.54 A high well density area has been identified in the Northern study area in the vicinity of the Masterton Junction. Here, the bedrock is either outcropping or near to the surface in several localities and as a result, the groundwater is considered more vulnerable to pollution.

7.3.55 Although considered impermeable, the igneous complexes are often outcropping or are near to the surface and host groundwater at shallow depths. The permeability characteristics of these rocks (by flow in fractures in the rock) and their low storage capacity and extension make these local aquifers extremely vulnerable to pollution and hydrodynamic disturbance.

Table 7.15: Hydrogeological Characteristics of Drift and Bedrock Units

Geological unit		Geological characteristics	Hydrogeological characteristics
Drift Deposits	Alluvium	Fine sand, silt, some clay with thin peat bands in place and locally some gravel. 1	Groundwater supplies are limited1 except where significant proportions of sand and gravel are present. Groundwater flow is intergranular.
	Glaciofluvial deposits.	Mainly sand and gravel1.	Groundwater potential of these deposits is generally poor because the water table is often near or below their bases1. Groundwater flow is intergranular.
	Till and undifferentiated drift	In large part represented by silty sandy clay till with clasts up to boulders (boulder clay) with subordinate marine deposits1. Made ground is locally important (e.g. St Margaret‘s Marsh).	None of these deposits yields groundwater1. However, shallow groundwater in made ground (dredged silts and clays) overlying natural marine silts and clays has been recorded in the St Margaret’s Marsh area (ENVIRONUK, 2007) and it is influenced by tides.
Bedrock	Dinantian and Namurian sedimentary strata (Upper and Lower Oil-Shale Group, Calciferous Sandstones Measures, Lower Limestone Group and Limestone Coal Group).	Sedimentary sequence comprising mainly sandstones, mudstones, siltstones and limestones. Beds of coals and oil-shales are present in particular to the south of Fife.	Moderately productive aquifers with fracture/intergranular flow2. Borehole yields no greater than 10 L/s in the Calciferous Sandstones Measures. In the Lower Limestone Group the groundwater potential is generally poor (borehole yields typically less than 0.5 L/s) 1,3. In the Limestone Coal Group the sandstones sustain borehole yields of 10 to 30 L/s particularly near old mine workings1. In the Limestone Coal Group groundwater quality is generally poor because of commonly highly mineralised reducing waters and bicarbonate concentration exceeding often 400 mg/L with high sulphate levels. Groundwater may also be rich in iron especially near old abandoned mines1. In the Calciferous Sandstones groundwater is in general of good quality and numerous boreholes have recorded yields of 4 to 12 L/s1.
	Mid Valley Sill complex and East Fife basanitic-foiditic Plugs and Vents.	Fine to medium grained sub volcanic - intrusive rocks.	These are considered as impermeable rocks, generally without groundwater except at shallow depth, where joints and fissures produce small springs1. Small-scale private groundwater wells are sometimes present.

Based on:
¹ Hydrogeological Map of Fife & Kinross (BGS, 1986);
² BGS Commissioned Report CR/04/04/7N;
³ Hydrogeological Map of Scotland (BGS, 1988) and Groundwater Vulnerability Map of Scotland (BGS, 1995).

Areas potentially supported by groundwater

7.3.56 During a recent site visit to St. Margaret’s Marsh undertaken on 02 May 2008 no obvious spring flows were observed into the marsh. A small channel was observed that connected the wooded area to the south of the site to the marsh; however, this was dry at the time of the site visit. Along the exposed rock promontory of the dolerite sill, drainage channels were noted but they too were dry at the time of the site visit. At this stage, the contribution of groundwater supply to the marshland at St Margaret’s Marsh can not be confirmed, but the features noted during the site visit and as described above would indicate that groundwater in this sector of the marsh is not very shallow and as such is not supporting the marshland.

7.3.57 Groundwater monitoring undertaken by ENVIRON UK Ltd. (Environ, 2007) between 2005 to 2007 shows that in the St. Margaret’s Marsh area shallow groundwater near to the foreshore is influenced by the tidal variations. This influence decreases as the distance away from the Firth of Forth increases. This is in agreement with a previous study on the east corner of the site (Envirocentre, 2004). Monitoring undertaken by ENVIRON UK Ltd. (Environ, 2007) indicates that water level in the drift fluctuates between 0.32m below ground level (bgl) (on 28/03/06) near to the foreshore and 3.98m bgl (on 04/07/06) at some 250m from the foreshore. In the bedrock the water level varies between 0.67m bgl (on 05/03/07) near to the foreshore to 4.26m bgl (on 04/07/06) at some 250m from the foreshore. According to ENVIRON UK Ltd. (2007), the bedrock aquifer behaviour is influenced by the tidal regime across the site. Groundwater flows from the marsh towards the Oil Fuel Depot (OFD) located to the northwest of St Margaret’s Marsh but reclamation of the site is expected to reverse the flow. The above considerations suggest that shallow groundwater which exists across the site is likely to support vegetation, especially close to the shoreline.

7.3.58 South Corridor Option 2 passes close to the Humbie Reservoir (NT 10500 75500). During a recent site visit, no obvious springs or groundwater seepages around the reservoir were observed. However, it may be in hydraulic continuity with shallow groundwater in the drift and may receive some recharge in the form of basal flow. The presence of a large area of marshy ground to the western end of the reservoir suggests the valley is a focus for shallow groundwater flow. The marshy area could be present as a result of a high water table.

7.3.59 An area of hydrological and landscape interest (Dundas Loch) is present on Dundas Estate (NT 11800 76100). The absence of superficial inflows and outflows suggests that the loch may be supported by shallow groundwater. Whether this is shallow groundwater in the drift, in the bedrock or in both it is unclear, and therefore the possibility that this loch may be fed by an underlying network of former mine workings can not be ruled out.

Private Water Supplies (PWS)

7.3.60 Information on the location of PWS such as wells and springs in the vicinity of the proposed route corridor options was obtained from current and historical OS maps. Where possible, these locations were confirmed during site walkover, and where feasible, additional information on their characteristics was gathered on site.

7.3.61 During DMRB Stage 2 consultation, North Queensferry Community Council provided information relating to an historic well in the Ferry Hill (well N03, Table 7.16). No other PWS information was gained during Stage 2 consultation.

7.3.62 Table 7.16 (for the Northern study area) and Table 7.17 (for the Southern study area) list the PWS identified in the vicinity of the proposed options. These are also indicated on Figure 7.3.

7.3.63 The presence of several wells and some springs in the igneous rocks indicates that these PWS are likely to be sourced by the groundwater that flows in fissures and joints at shallow depths. The presence of faults at or close to wells N01, N02, N03, N11, N12, N18, N19 and N20, suggests that the fracture network may be particularly developed at these locations, creating favourable conditions for the movement of groundwater.

Table 7.16: Groundwater Supplies in the Northern Study Area

Supply No.	Location	Type	Hydrogeological assumptions
N01	Main Road, North Queensferry	Well	Geological and Hydrogeological maps suggest that the well is sourced by shallow groundwater in the fractured dolerite sill. It is unknown whether the well is operational.
N02	Brock Street, North Queensferry	Spring	Geological and Hydrogeological maps suggest that the spring is sourced by shallow groundwater in the fractured dolerite sill. It is unknown whether the spring is used.
N03	Ferry Loch, Ferry Hills	Well	Geological and Hydrogeological maps suggest that the well is sourced by shallow groundwater in the fractured dolerite sill. It is unknown whether the well is operational.
N04	Castlandhill House	Well	Geological and Hydrogeological maps suggest that the well is sourced by shallow groundwater in the dolerite sill. It is unknown whether the well is operational.
N05	The Hills, Inverkeithing	Well	Geological and Hydrogeological maps suggest that the well is sourced by shallow groundwater in the fractured dolerite sill. It is unknown whether the well is operational.
N06	Mills, Inverkeithing	Well	Geological and Hydrogeological maps suggest that the well is sourced by shallow groundwater in fractured the dolerite sill. It is unknown whether the well is operational.
N07	District offices, Inverkeithing	Well	Geological and Hydrogeological maps suggest that the well is sourced by shallow groundwater in the fractured dolerite sill. It is unknown whether the well is operational.
N08	The Wilderness, Rosyth	Spring	From the available geological and hydrogeological maps it is unclear the origin of the spring. It is also unknown whether the spring is used.
N09	Middlebank House, Middlebank	Well	Geological and Hydrogeological maps suggest that the well may be sourced by the Lower Limestone Group. It is unknown whether the well is operational.
N10	Mastertown	Well	Drift thickness map (NT18SW) suggests that this area is underlain by glacial till less than 5 m thick. There is the possibility that the well is sourced by groundwater in the underlying limestones. It is unknown whether the well is operational.
N11	St Theriots’ Well, Fordell Castle	Well	Geological and Hydrogeological maps suggest that the well is sourced by groundwater in the fractured sub volcanic/limestone rocks. The fracturing is assumed to be important at this location because of the presence of a fault. It is unknown whether the well is operational.
N12	Belleknowes Industrial Estate	Well	Geological and Hydrogeological maps suggest that the spring is sourced by shallow groundwater in the fractured sub volcanic/limestone rocks. The fracturing is assumed to be important at this location because of the presence of a fault. It is unknown whether the well is operational.
N13	Dales Farm	Spring	Drift thickness map (NT18SW) suggests that this area is underlain by drift deposits less than 7-8 m thick. It is unknown whether the spring is used.
N14	Dales Farm Cottages	Well	Drift thickness map (NT18SW) indicates that bedrock is near to the ground surface at this location. Well possibly sourced by the Carboniferous limestones. It is unknown whether the well is operational.
N15	Middlebank	Well	Drift thickness map (NT18SW) suggests that the well is sourced by the Carboniferous limestones. It is unknown whether the well is operational.
N16	Duloch House	Well	Drift thickness map (NT18SW) indicates that bedrock is relatively near to the ground surface at this location. Well possibly sourced by the Carboniferous limestones. It is unknown whether the well is operational.
N17	Old Duloch	Well	This location is underlain by till of unknown thickness. Unknown whether the well is sourced by the underlying Carboniferous limestones. It is also unknown whether the well is operational.
N18	Coldwells Cottages	Well	A recent site visit indicated that the well is approximately 3-4m deep and the water was approximately 1m below the top of the well. Abandoned well: the proprietor indicated that the property was on mains supply and they had no intention of using the well in the future. The landowner stated that during very wet weather the water levels quickly rise to the top of the well and frequently overflow flooding the garden. On these occasions the landowner pumps water out of the well and can reduce the level by several metres within 10 minutes. The well may be sourced by the soil and shallow groundwater in the fractured bedrock.
N19	Blazehill Plantation, Fordell Firs Activity Centre	Well	A recent site visit confirmed that the well is located at the edge of the marshy ground and is of a brick lined construction. No measurements were taken but it is approximately 3-4m deep and the water was approximately 1m below the top of the well. There was no infrastructure or buildings near the well and it is assumed to be abandoned. The well may be sourced by the soil and shallow groundwater in the fractured bedrock.
N20	Fordell Firs Scout Camp Site	Well	Geological and Hydrogeological maps suggest that the spring is sourced by groundwater in the fractured sub volcanic/limestone rocks. The fracturing is assumed to be important at this location because of the presence of a fault. It is unknown whether the well is operational.
N21	Perth Lodge	Well	Geological and Hydrogeological maps suggest that the well may be sourced by shallow groundwater in the fractured sub volcanic rocks. It is unknown whether the well is operational.
N22	Annfield	Well	Geological and Hydrogeological maps suggest that the well is sourced by shallow groundwater in the fractured sub volcanic rocks. It is unknown whether the well is operational.

Table 7.17 Groundwater Supplies in the Southern Study Area

Supply No.	Location	Type	Hydrogeological assumptions
S01	Milrig	Well	Well at or adjacent to glaciofluvial deposits. Unknown source of groundwater. It is also unknown whether the well is operational.
S02	Newliston	Spring	Spring at or adjacent geological contact between intrusive and sedimentary rocks. Unknown source of groundwater and whether the spring is used.
S03	Overton	Well	Well in area of sedimentary bedrock outcropping or near to ground surface. Likely to be sourced by fractures in the sedimentary rocks. It is unknown whether the well is operational.
S04	Humbie Farm	Well	The well is in an area of glacial till. Source of groundwater and use of the well is unknown.
S05	Whitelees	Well	Well in area covered by drift deposits. Unknown source of groundwater. It is also unknown whether the well is operational.
S06	Chapel Acre, Dundas Castle	Well	Well in area of dolerite outcropping or near to surface. Well possibly sourced by shallow groundwater circulating in the fractures of the bedrock. It unknown whether the well is operational.
S07	B924, South Queensferry	Well	Well in area of sedimentary bedrock outcropping or close to ground surface. Well possibly sourced by groundwater circulating in the fractures of the sedimentary rocks. It is unknown whether the well is operational.

7.4 Potential Impacts

7.4.1 The following section identifies potential impacts in the absence of mitigation. The approach to mitigation is set out in Section 7.5 (Potential Mitigation).

Proposed Replacement Bridge

7.4.2 No sites or designated features of geological/geomorphological interest would be affected by the proposed replacement bridge. The geology is therefore considered to have a low sensitivity and as a consequence predicted potential impacts are considered to be Negligible.

7.4.3 In relation to mineral extraction, no potential impacts are predicted from the development of the bridge itself.

7.4.4 As discussed in paragraph 7.3.30, the Firth of Forth has been extensively dredged and reworked over the last century. Residual contamination from industries present in the banks of the river, including radioactive particles and metals, may be present in the sediments on the river bed.

7.4.5 The potential risk to receptors from potential contamination is summarised in Table 7.18. The detailed site investigation that is being undertaken at the time of this report will provide more information on the true nature and extent of contamination in this area.

Table 7.18: Summary of Potential Risks Associated with Contaminated Land - Firth of Forth

Source	Pathway	Receptor	Probability	Consequence	Risk (unmitigated)
Residual contamination in the river bed sediments including heavy metals and radioactive particles	Dermal contact	Construction workers	Likely	Medium	Moderate
	Inhalation		Low likelihood	Medium	Moderate/Low
	Ingestion		Unlikely	Medium	Low
	Migration of contamination during construction	Marine ecology	Likely	Mild	Moderate/Low
	Migration of contamination during construction	Firth of Forth	Likely	Mild	Moderate/Low
	Migration of contamination during construction	Groundwater	Low likelihood	Mild	Low

7.4.6 In relation to the groundwater environment and PWS, no potential impacts are expected from the development of the bridge itself.

Northern Route Corridor Options

Impacts Common to Both Northern Route Corridor Options

7.4.7 Both options would impact equally upon the geologically important Firth of the Forth SSSI as both proposed route corridors cut through a section of this area. The geology within this designated area is considered to have a high sensitivity. The magnitude of the impact of the Forth Replacement Crossing construction is considered to be low as the land area which would be affected is relatively small in relation to the area covered by the designation. The potential impact of both northern route corridor options on the geological features of the Firth of Forth SSSI is therefore considered to be of Moderate significance.

7.4.8 With regards to mineral extraction, both options cross over or would be expanded into a number of former quarries. A number of these quarries remain visible, with the remainder either filled or reworked during earlier construction. Where these quarries are backfilled, the potential for subsidence due to the weight of roads infrastructure would need to be considered, although the nature of the backfilled material is currently unknown. No quarries within the study are known to be currently active and therefore there would be no economic impact on quarry production as a result of the Forth Replacement Crossing.

7.4.9 Both options would cross through or would expand into areas where reserves of coal are believed to exist; however, no currently active coal mines are located within the Northern study area and no future mining licences are currently being considered by the Coal Authority. As discussed in paragraph 7.2.8, the existence of coal primarily represents engineering considerations for the Forth Replacement Crossing construction and their extent, nature and required mitigation can only be assessed fully by intrusive site investigation.

7.4.10 With regards to contaminated land, the former Rosyth and Mineral Railways would cross both northern route corridor options three routeanded roadas a result of the road and are located straints in teh aster. If you do not have a copy of these correct. There is the potential for historic residual contamination to be present in these areas including heavy metals, hydrocarbons and pesticides. The risks posed by these railways are considered to be moderate to low.

7.4.11 The rationale and criteria given below to identify potential impacts on groundwater are valid for both the options in the Northern study area:

• Local groundwater flows and levels can be affected in areas of deep road cutting that extend below local groundwater levels. The resultant dewatering of the groundwater bodies into the road drainage and locally reduced groundwater levels can affect habitats sustained by groundwater (e.g. marshlands), groundwater abstractions and in extreme cases can significantly reduce low flows in watercourses.
• In the event of an accidental road spillage, particularly during construction, contamination may migrate through the unsaturated zone and impairing underlying groundwater quality, unless appropriate drainage protection or other suitable mitigation measures are implemented; this is considered in Chapter 8 (Water Environment).

7.4.12 The area of high well density encountered in the vicinity of Masterton Junction under either northern route corridor option faces a section of embankment and a section of cutting.

North Corridor Option 1

Geology and Geological/Geomorphological Features of Importance

7.4.13 The road widening associated with North Corridor Option 1 marginally infringes into two areas of the Ferry Hills SSSI (geological), including the former Ferrytoll Quarry area. In addition, the embankments associated with this route corridor marginally infringe on the eastern edge of the St. Margaret’s Marsh SSSI (biological). The potential impact of North Corridor Option 1 on these sites is outlined in Table 7.19.

Table 7.19: Summary of Potential Impacts on Geologically Important Sites - North Corridor Option 1

Receptor	Sensitivity	Magnitude	Significance (unmitigated)
Ferry Hills SSSI (protected igneous geology)	High	Low - the loss of volume of igneous geology as a consequence of the excavation would only marginally infringe on these areas. - the obscuring of existing rock outcrops along the A90 would be minimal.	Moderate
St. Margaret’s Marsh SSSI (biological but supported by geomorphological feature- salt marsh)	High	Low - only a small proportion of the widened road would be located in this area, with relatively little loss of littoral landscape as a consequence.	Moderate

Mineral Extraction

7.4.14 Potential impacts are common to both northern route corridor options and are discussed in paragraphs 7.4.8 and 7.4.9.

Contaminated Land

7.4.15 Several quarries have been identified in this study area, including a number of historic quarries which coincide with the route corridor.. North Corridor Option 1 crosses over one of these quarries, the former Welldean Quarry, and also marginally infringes on the former Ferrytoll Quarry as a result of the proposed road widening. These quarries are not considered likely to pose a contamination risk; however, the nature and source of fill used during the construction is unknown and there is therefore some uncertainty as to whether contaminated materials may be intercepted by the North Corridor Option 1 roadworks in these areas.

7.4.16 This route corridor option lies immediately adjacent to Belleknowes Industrial Estate which includes the former brick and tile works and associated clay pit. Historically, many of the resulting ‘clay pits’ associated with former brick works were backfilled with a range of commercial and industrial wastes. It is not known whether this practice has been adopted in this instance as the former clay pit is currently filled with water. There is the potential for contaminants, including heavy metals and organic contaminants, to migrate from this potential source towards the area of construction; however, no evidence of this has been recorded to date. Work in this area would involve road widening in line with the existing road and the likelihood of the construction workers coming in contact with contamination is low.

7.4.17 There is also the potential for contamination and in-filled ground to be present as a result of other historical industries located within the Belleknowes Industrial Estate. Again, as work in this area would involve road widening in line with the existing road, the likelihood of encountering contamination is low.

7.4.18 The embankments associated with North Corridor Option 1 marginally infringe on the St. Margaret’s Marsh area. There is the potential for contaminants, including radioactive particles and landfill gas, to be present in this area; however, as only embankments are to be located in this area the risk associated with this potential contamination is low. No evidence of the migration of contaminants in to the works area has been recorded to date.

7.4.19 The former Ferrytoll Quarry Works (Figure 7.1b: Contaminated Land) lies in the route corridor, within the footprint of the former Ferry Toll Quarry. There is the potential for residual contamination to be present in this area; however, as this area was significantly excavated, reworked and restored during the construction of the Forth Road Bridge, it is therefore likely to pose only a minor risk. In addition, the majority of the former works is now occupied by the existing A90/M90 and would therefore be subject to minimal disturbance during the works.

7.4.20 A wastewater treatment works is located approximately 50m west of North Corridor Option 1 (Figure 7.1b). There is the potential for contaminants, including heavy metals, pathogens and organic contaminants, to migrate from this potential source towards the area of construction.

7.4.21 A summary of the potential risks posed by encountering contaminated land during construction of the Forth Replacement Crossing are summarised in Table 7.20.

Table 7.20: Summary of Potential Risks Associate with Contaminated Land - North Corridor Option 1

Source	Pathway	Receptor	Likelihood	Consequence	Risk (unmitigated)
Made ground in in-filled quarries	Dermal contact	Construction workers	Low	Medium	Moderate/Low
	Inhalation		Unlikely	Medium	Low
	Ingestion		Unlikely	Medium	Low
	Migration of contamination	Surface water	Low	Medium	Moderate/Low
		Groundwater	Low	Mild	Low
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Unlikely	Mild	Very Low
Past and present industrial processes, including a brick and tile works, on the Belleknowes Industrial Estate.	Historical migration leading to potential direct contact, inhalation or ingestion.	Construction workers	Low	Medium	Moderate/Low
	Migration of contamination	Surface water	Low	Mild	Low
		Groundwater	Low	Mild	Low
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Low	Mild	Low
Radioactive and landfill-related contamination from St. Margaret’s Marsh area	Historical migration of contamination leading to potential direct contact, inhalation or ingestion.	Construction workers	Low	Medium	Moderate/low
	Migration of landfill gases		Low	Medium	Moderate/Low
Former Ferrytoll Quarry Works	Dermal contact	Construction workers	Low	Medium	Moderate/Low
	Inhalation		Unlikely	Medium	Low
	Ingestion		Unlikely	Medium	Low
	Migration of contamination	Surface water	Unlikely	Medium	Low
		Groundwater	Unlikely	Mild	Very Low
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Unlikely	Mild	Very Low
Waste water treatment works	Historical migration leading to potential direct contact, inhalation or ingestion.	Construction workers	Unlikely	Medium	Low
	Migration of contamination	Surface water	Unlikely	Medium	Low
		Groundwater	Unlikely	Mild	Very Low
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Unlikely	Mild	Very Low

7.4.22 Dependant on the type of contamination present, soils may need to be transported from site or treated on site in line with current regulations. The Ground Investigation being undertaken at the time of this report will provide more information on the ground conditions in these areas.

Groundwater Environment

7.4.23 Potential impacts on the following groundwater body and potentially groundwater-supported feature may occur along the North Corridor Option 1. However, as the proposed route corridor largely comprises marginal expansions of an existing road corridor rather than a new road, the magnitude of the impacts of this route corridor option are low, as shown in Table 7.21 .

Table 7.21: Summary of Potential Impacts on North Corridor Option 1

Groundwater Receptor	Sensitivity	Potential Impact (unmitigated)
		Magnitude	Significance
Shallow groundwater potentially supporting St Margaret’s Marsh	High	Low (and very localised): - drainage system related to the new road embankment could potentially alter existing surface water inflows to the marsh and therefore its groundwater balance. - potentially contaminated runoff from the proposed road may enter the shallow groundwater.	Moderate

7.4.24 North Corridor Option 1 passes over areas where the Lower Limestone Group is exposed or close to the ground surface. These areas are located in the surroundings of Middlebank (Figure 7.3b). Because of the presence of fractures in the unsaturated zone of the limestone, potential pollutants produced during the construction (i.e. storage of oils and fuel) and operation (oils, fuel, coolants, salts and heavy metals) of the proposed route corridor option may enter the unsaturated zone and travel quickly and with low attenuation to the saturated zone. On this basis, these areas are considered as highly vulnerable to potential pollution incidents which may occur during the construction of the road and its operation.

7.4.25 It is not known at this stage whether the shallow groundwater supports any of the designated surface water features (i.e. stream and ponds).

7.4.26 In addition to direct recharge from rainfall and indirect recharge from runoff, it is possible that the superficial deposits in St Margaret’s Marsh area are receiving some indirect recharge in the form of lateral flow through the shallow fractured bedrock. However, the superficial deposits are obviously receiving seawater either indirectly or directly as evidenced by salinity of the groundwater as reported in the previous contaminated land investigations (Environ, 2007). It is not possible to determine the proportions and relative hydrological importance of the four sources of recharge on St Margaret’s Marsh at this stage. In this locality, the proposed route corridor would incorporate an embankment along the south eastern boundary of the marsh. An embankment is already present along this boundary of the marsh and it is not known whether this influences the water balance of the marsh. The new embankment is unlikely to cause a significant reduction in the lateral groundwater component previously introduced. However, during its construction, the same surface water inflows and therefore the same groundwater balance of the marsh needs to be preserved. Road drainage proposals in this area will need to take cognisance of the marsh sensitivity to avoid contamination; this is considered in Chapter 8 (Water Environment).

Private Water Supplies (PWS)

7.4.27 Magnitude of impact on PWS quality is assessed as high in a cutting area and medium in an embankment area. Magnitude of impact on PWS flow is assessed as follows (taking into account uncertainties on likely cutting depths):

• high in cutting areas;
• medium in cutting area which is on or adjacent to an existing A90 cutting;
• medium in a transition embankment/cutting zone;
• low in a transition embankment/cutting zone where the cutting is on or adjacent to an existing A90 cutting; and
• negligible in an embankment area.

7.4.28 Significance of potential impacts of North Corridor Option 1 on individual PWS on both quality and flow taking account of sensitivity and magnitude identified above are reported in Table 7.22. This indicates that PWS N05 and N15 are potentially the two supplies the most at risk in terms of quality and flow in the absence of mitigation (Moderate/Substantial significance).

Table 7.22: Summary of Potential Impacts Associated with PWS - North Corridor Option 1

PWS	Sensitivity	Potential impact on groundwater quality (unmitigated)		Potential Impact on groundwater flow (unmitigated)
		Magnitude	Significance	Magnitude	Significance
N01	Low	High	Moderate	Medium	Slight/Moderate
N02	Low	High	Moderate	Medium	Slight/Moderate
N03	Medium	High	Moderate/Substantial	Medium	Moderate
N04	Medium	High	Moderate/Substantial	Medium	Moderate
N05	High	High	Substantial	Medium	Moderate/Substantial
N06	Medium	High	Moderate/Substantial	Medium	Moderate
N07	Low	High	Moderate	Medium	Slight/Moderate
N08	Medium	Medium	Moderate	Negligible	Negligible/Slight
N09	High	Medium	Moderate/Substantial	Negligible	Slight
N10	Medium	Medium	Moderate	Negligible	Negligible/Slight
N11	Negligible	High	Slight	Medium	Negligible/Slight
N12	Medium	Medium	Moderate	Negligible	Negligible/Slight
N13	Medium	Medium	Moderate	Negligible	Negligible/Slight
N14	Medium	Medium	Moderate	Negligible	Negligible/Slight
N15	High	High	Substantial	Medium	Moderate/Substantial
N16	Medium	High	Moderate/Substantial	Medium	Moderate
N17	Medium	High	Moderate/Substantial	Medium	Moderate
N18	Negligible	High	Slight	Medium	Negligible/Slight
N19	Medium	High	Moderate/Substantial	Medium	Moderate
N20	Medium	High	Moderate/Substantial	Medium	Moderate
N21	Medium	High	Moderate/Substantial	Medium	Moderate
N22	Negligible	High	Slight	Medium	Negligible/Slight

North Corridor Option 2

Geology and Geological/Geomorphological Features of Importance

7.4.29 North Corridor Option 2 crosses through approximately 5% of the Ferry Hills SSSI (geological) including the former Fairy Kirk Quarry area, and over approximately 10% of St. Margaret’s Marsh SSSI (biological). The potential impact of North Corridor Option 2 on this site is outlined in Table 7.23.

Table 7.23: Summary of Potential Impacts on Geologically Important Sites- North Corridor Option 2

Receptor	Sensitivity	Potential Impact (unmitigated)
		Magnitude	Significance
St. Margaret’s Marsh SSSI (biological but supported by geomorphological feature- salt marsh)	High	Medium - significant area (approximately 10%) of the littoral landscape would be lost.	Moderate/ Substantial
Ferry Hills SSSI (protected igneous geology)	High	Low - the road and associated cuttings would remove the majority of the Fairy Kirk Quarry area (protected igneous geology), totalling approximately 5% of the overall designated area.	Moderate

Mineral Extraction

7.4.30 The potential impacts are common to both options and are discussed in paragraphs 7.4.8 and 7.4.9.

Contaminated Land

7.4.31 Several former and present quarries have been identified in line with the route corridor, including Fairy Kirk Quarry which is directly in line with North Corridor Option 2. As a result of the desk study and site visits, it has been determined that these quarries are unlikely to pose a significant potential source of contamination. However, the possibility of partial filling cannot be ruled out. As with North Corridor Option 1, the nature and source of any fill material used in the past is unknown and further investigation would be required to identify any contamination present in the made ground in these areas.

7.4.32 St Margaret’s Marsh and the landfill located within this area lie in the path of the North Corridor Option 2 and are likely to present a significant source of contaminants, including typical landfill contaminants such as heavy metals and nitrates and landfill gases such as methane and carbon monoxide. In addition, there is also the potential for low level radioactivity to be present in these areas.

7.4.33 There is a large wastewater treatment works to the immediate west of the embankment associated with North Corridor Option 2 to the north of St. Margaret’s Marsh (Figure 7.1b). There is the potential for contamination to migrate from this works into the near by soils in the construction area and may include metals, organics and pathogens.

7.4.34 North Corridor Option 2 crosses through the Belleknowes Industrial Estate and the Network Rail North Discharge sidings area. Visual evidence of surface hydrocarbon contamination was observed during a site visit to the Network Rail Yard. In addition, there is potential for contamination across the remainder of this area due to past and current industrial use.

7.4.35 The former Ferrytoll Quarry Works lies in the path of North Corridor Option 2. There is the potential for residual contamination to be present in this area; however, as this area was significantly excavated, reworked and covered over during the construction of the Forth Road Bridge and is therefore likely to only pose a minor risk.

7.4.36 A summary of the potential risks posed by encountering contaminated land during construction of the Forth Replacement Crossing are summarised in Table 7.24.

Table 7.24: Summary of Potential Risks Associated with Contaminated Land - North Corridor Option 2

Source	Pathway	Receptor	Likelihood	Consequence	Risk (unmitigated)
Made ground in in-filled quarries	Dermal contact	Construction workers	Low	Medium	Moderate/low
	Inhalation		Unlikely	Medium	Low
	Ingestion		Unlikely	Medium	Low
	Migration of contamination	Surface water	Low	Medium	Moderate/low
		Groundwater	Low	Mild	Low
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Unlikely	Mild	Very low
Past and present industrial processes, including Network Rail Discharge sidings (Belleknowes Industrial Estate)	Dermal contact	Construction workers	High	Medium	High
	Inhalation		Likely	Medium	Moderate
	Ingestion		Low	Medium	Moderate/low
	Migration of contamination	Surface water	Low	Mild	Low risk
	Migration of contamination during construction	Groundwater	Low	Mild	Low risk
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Low	Mild	Low
Radioactive and landfill-related contamination from St. Margaret’s Marsh area	Dermal contact	Construction workers	High	Medium	High
	Inhalation		Likely	Medium	Moderate
	Ingestion		Low	Medium	Moderate/Low
	Migration of contamination	Surface water	Likely	Medium	Moderate
		Groundwater	Likely	Mild	Moderate/Low
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Low	Mild	Low
Former Ferrytoll Quarry Works	Dermal contact	Construction workers	Low	Medium	Moderate/Low
	Inhalation		Unlikely	Medium	Low
	Ingestion		Unlikely	Medium	Low
	Migration of contamination	Surface water	Unlikely	Medium	Low
		Groundwater	Unlikely	Mild	Very Low
	Migration of contamination leading to plant uptake or dermal contact	Ecological	Unlikely	Mild	Very Low
Waste water treatment works	Historical migration of contamination leading to potential direct contact, inhalation, ingestion	Construction workers	Low	Medium	Moderate/Low
	Migration of contamination	Surface water	Unlikely	Medium	Low
		Groundwater	Unlikely	Mild	Very Low
	Migration of contamination leading to plant uptake and dermal contact by animals	Ecological	Unlikely	Mild	Very Low

7.4.37 Depending on the type of contamination present, soils may need to be transported from site or treated on site in line with current regulation. The detailed site investigation that is being undertaken at the time of this report will provide more information on the ground conditions in these areas.

Groundwater Environment

7.4.38 Potential impacts on the following groundwater body and potentially groundwater-supported feature may occur along the North Corridor Option 2 , as summarised in Table 7.25

Table 7.25: Summary of Potential Hydrogeological Impacts on Sensitive Receptors - North Corridor Option 2

Groundwater Receptor	Sensitivity	Potential Impact (unmitigated)
		Magnitude	Significance
Shallow groundwater potentially supporting St Margaret’s Marsh	High	Moderate - drainage system related to the new road embankment could potentially alter existing surface water inflows to the marsh and therefore its groundwater balance. - potentially contaminated runoff from the proposed road may enter the shallow groundwater.	Moderate/ Substantial

7.4.39 North Corridor Option 1 would pass to the east of the Middlebank area, which has been previously identified as an area highly vulnerable to pollution. For this reason, groundwater quality beneath parts of North Corridor Option 2 is considered to be less vulnerable to pollution than those beneath North Corridor Option 1.

7.4.40 However, overall impacts on groundwater flow and quality are expected to be greater than in North Corridor Option 1 because North Corridor Option 2 is not online and would cause considerably greater disturbance.

7.4.41 The greatest impacts in terms of groundwater quality along North Corridor Option 2 are expected in the area in the vicinity of Dales Farm Cottages (Figure 7.3b).

7.4.42 In relation to groundwater supporting sensitive habitats, the considerations set out in paragraph 7.4.26 are still valid. However, it is worthwhile noting that the North Corridor Option 2 land take is likely to have a slightly greater impact on St Margaret’s Marsh as there is a greater potential for reducing the inflows into the marsh, depending on where the road drainage is directed.

Private Water Supplies (PWS)

7.4.43 Magnitude of impact on PWS quality is assessed as high in a cutting area and medium in an embankment area. Magnitude of impact on PWS flow is assessed as follows (taking into account uncertainties on likely cutting depths):

• high in cutting areas;
• medium in cutting area which is on or adjacent to an existing A90 cutting;
• medium in a transition embankment/cutting zone;
• low in a transition embankment/cutting zone where the cutting is on or adjacent to an existing A90 cutting; and
• negligible in an embankment area.

7.4.44 Significance of potential impacts of North Corridor Option 2 on individual PWS on both quality and flow taking account sensitivity and magnitude identified above are reported in Table 7.22. This indicates that the highest significance of potential impact is N04 and N05 (Moderate/Substantial).

Table 7.26: Summary of Potential Impacts Associated with PWS - North Corridor Option 2

PWS	Sensitivity	Potential impact on groundwater quality (unmitigated)		Potential Impact on groundwater flow (unmitigated)
		Magnitude	Significance	Magnitude	Significance
N01	Low	Medium	Slight/Moderate	Negligible	Negligible
N02	Low	Medium	Slight/Moderate	Negligible	Negligible
N03	Medium	Medium	Moderate	Negligible	Negligible/Slight
N04	Medium	High	Moderate/Substantial	High	Moderate/Substantial
N05	Medium	High	Moderate/Substantial	High	Moderate/Substantial
N06	Low	High	Moderate	High	Moderate
N07	Low	Medium/High	Moderate	Low	Negligible/Slight
N08	Negligible	Medium	Negligible/Slight	Negligible	Negligible
N09	Medium	Medium	Moderate	Negligible	Negligible/Slight
N10	Negligible	Medium	Negligible/Slight	Negligible	Negligible
N11	Negligible	High	Slight	Medium	Negligible/Slight
N12	High	Medium	Moderate/Substantial	Negligible	Slight
N13	Medium	Medium	Moderate	Negligible	Negligible/Slight
N14	High	Medium	Moderate/Substantial	Negligible	Slight
N15	Medium	Medium/High	Moderate	Medium	Moderate
N16	Medium	High	Moderate/Substantial	Medium	Moderate
N17	Medium	High	Moderate/Substantial	Medium	Moderate
N18	Negligible	High	Slight	Medium	Negligible/Slight
N19	Medium	High	Moderate/Substantial	Medium	Moderate
N20	Medium	High	Moderate/Substantial	Medium	Moderate
N21	Medium	High	Moderate/Substantial	Medium	Moderate
N22	Negligible	High	Slight	Medium	Negligible/Slight

Southern Route Corridor Options

Impacts Common to Both Southern Route Corridor Options

7.4.45 No impacts on sites of geological/geomorphological importance have been identified from either of the southern route corridor options or associated cuttings. The Firth of Forth SSSI area lies to the east of the route corridor options and it is not anticipated that it would be affected by the works.

7.4.46 No former quarrying areas would be affected by either of the two southern route corridor options.

7.4.47 Both southern route corridor options would cross over the Stores area via a viaduct at the southern shore. The Stores area is currently occupied by several small industrial units connected with the sailing industry. It is expected that made ground would be present in this area and that residual contamination, including organic contaminants from historical fuel storage, may be present in the soils in this area.

7.4.48 A summary of the potential risks posed by contaminated land in the Stores area as a result of the construction of the Forth Replacement Crossing are detailed in Table 7.27.

Table 7.27: Summary of Potential Risks Associated with Contaminated Land - Common to Both Southern Route Corridor Options

Source	Pathway	Receptor	Likelihood	Consequence	Risk (unmitigated)
Residual contamination associated with the Stores area and associated potential fuel storage	Dermal contact	Construction workers	Low	Medium	Moderate/Low
	Inhalation		Unlikely	Medium	Low
	Ingestion		Unlikely	Medium	Low
	Migration of contamination during construction	Surface waters	Unlikely	Medium	Low
		Groundwater	Unlikely	Mild	Very Low
	Migration of contamination during construction leading to plant uptake or dermal contact by animals	Ecological	Unlikely	Mild	Very Low

7.4.49 Dependant on the type of contamination present in the Stores area, soils may need to be transported from site or treated on site in line with current regulation during viaduct construction. The detailed site investigation being undertaken at the time of this report will provide more information on the ground conditions in these areas.

South Corridor Option 1

Mineral Extraction

7.4.50 South Corridor Option 1 crosses through areas where reserves of coal are believed to exist; however, no currently active coal mines are located within the near vicinity and no future mining licences are currently being considered by the Coal Authority.

7.4.51 Disused oil shale mining shafts and adits have been identified in the near vicinity of this route corridor option. Although oil shale mining is no longer undertaken in this area, the construction of South Corridor Option 1 could potentially deplete oil shale resources which may be of use in the future to produce products such as synthetic crude oil.

Groundwater

7.4.52 South Corridor Option 1 does not appear to cross extensive areas where bedrock is either exposed or lies near to surface. Most of the bedrock in the area is covered by low permeability drift with significant thickness (i.e. > 1m; Figure 7.3). As a result, the bedrock aquifers are not considered to be highly vulnerable to contamination. The groundwater vulnerability will depend however, on the depth of the water table (or thickness of the unsaturated zone) and the exact thickness and composition of the drift. At this stage, data are scarce and it is not possible to consider this aspect in more detail.

7.4.53 The only area where bedrock is exposed, or may be near to surface, is between the B924 and Dundas Mains. Only one PWS was identified in this area (S07; refer to paragraph 7.3.55).

Private Water Supplies (PWS)

7.4.54 Magnitude of impact on PWS quality is assessed as high in a cutting area and medium in an embankment area. Magnitude of impact on PWS flow is assessed as follows (taking into account uncertainties on likely cutting depths):

• High in cutting areas;
• Medium in cutting area which is on or adjacent to an existing A90 cutting;
• Medium in a transition embankment/cutting zone;
• Low in a transition embankment/cutting zone where the cutting is on or adjacent to an existing A90 cutting; and
• Negligible in an embankment area.

7.4.55 Significance of potential impacts of South Corridor Option 1 on PWS are presented in Table 7.28. This indicates that the highest significance of potential impact is at S07 (Moderate/Substantial).

Table 7.28: Summary of Potential Impacts Associated to PWS - South Corridor Option 1

PWS	Sensitivity	Potential impact on groundwater quality (unmitigated)		Potential Impact on groundwater flow (unmitigated)
		Magnitude	Significance	Magnitude	Significance
S01	Low	Medium	Slight/Moderate	Negligible	Negligible
S02	Negligible	Medium/High	Slight	Medium	Negligible/Slight
S03	Medium	Medium/High	Moderate	Medium	Moderate
S04	Medium	Medium	Moderate	Negligible	Negligible/Slight
S05	Low	Medium/High	Moderate	Low	Slight
S06	Low	High	Moderate	High	Moderate
S07	Medium	High	Moderate/Substantial	High	Moderate/Substantial

South Corridor Option 2

Mineral Extraction

7.4.56 South Corridor Option 2 crosses through areas where reserves of coal are believed to exist; however, no currently active coal mines are located in the vicinity and no future mining licences area currently being considered by the Coal Authority.

7.4.57 Disused oil shale mining shafts and adits have been identified in the vicinity of this route corridor option. Although oil shale mining is no longer undertaken in this area, the construction of South Corridor Option 2 could potentially deplete oil shale resources which may be of use in the future to produce products such as synthetic crude oil.

Contaminated Land

7.4.58 The route corridor crosses through the former Depot/Westmuir Riding Centre, as illustrated on Figure 7.1c, which is now Westmuir Riding Centre. Although made ground is anticipated in this area, the likelihood of contamination is considered low due to the historical land use.

7.4.59 The route corridor also crosses through and adjacent to a number of former oil shale mineshafts and adits. There is the potential for contamination to be present in these areas due to the possible infilling of these shafts with mining spoil. In addition, there is also the potential for mine gas to be present.

7.4.60 The oil storage depot at Dalmeny, as illustrated in Figure 7.1c, is located approximately 100m south of South Corridor Option 2. There is the potential for contamination to migrate from this area into the near by soils in the construction area and may include organics contaminants.

7.4.61 Potential risks associated with contaminated land in South Corridor Option 2 are summarised in Table 7.29.

Table 7.29: Summary of Potential Risks Associate with Contaminated Land - South Corridor Option 2

Source	Pathway	Receptor	Likelihood	Consequence	Risk (unmitigated)
Former depot area	Dermal contact	Construction workers	Unlikely	Medium	Low
	Inhalation		Unlikely	Medium	Low
	Ingestion		Unlikely	Medium	Low
	Migration of contamination during construction	Surface water	Unlikely	Medium	Low
		Groundwater	Unlikely	Mild	Very Low
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Unlikely	Mild	Very Low
Disused Oil Shale Mine Shafts and Adits	Dermal contact	Construction workers	Low	Medium	Moderate/Low
	Inhalation/ Explosion of mine gas		Low	Severe	Moderate
	Ingestion		Unlikely	Medium	Low
	Migration of contamination during construction	Surface water	Low	Medium	Moderate/Low
		Groundwater	Likely	Mild	Moderate/Low
	Migration of contamination leading to plant uptake or dermal contact by animals	Ecological	Low	Mild	Low
Oil storage depot	Historical migration of contamination leading to potential direct contact, inhalation, ingestion	Construction workers	Low	Medium	Moderate/Low
	Migration of contamination	Surface water	Low	Medium	Moderate/Low
		Groundwater	Low	Mild	Low
	Migration of contamination leading to plant uptake and dermal contact by animals	Ecological	Unlikely	Mild	Very Low

7.4.62 Additional potential impacts are common to both options and are discussed previously.

7.4.63 Dependant on the type of contamination present in the Depot and disused mineshafts area, soils may need to be transported from site or treated on site in line with current regulation. The detailed site investigation that is being undertaken at the time of this report will provide more information on the ground conditions in these areas.

Groundwater Environment

7.4.64 South Corridor Option 2 passes over areas where the bedrock is covered by drift deposits with thickness greater than 1m (Figure 7.3). On this basis the bedrock aquifers are not considered to be highly vulnerable to pollution.

7.4.65 South Corridor Option 2 passes near Humbie Reservoir however, no impacts are predicted on groundwater flow potentially supporting the reservoir while impacts on the water quality of the reservoir are addressed in Chapter 8 (Water Environment).

Private Water Supplies

7.4.66 Magnitude of impact on PWS quality is assessed as high in a cutting area and medium in an embankment area. Magnitude of impact on PWS flow is assessed as follows (taking into account uncertainties on likely cutting depths):

• high in cutting areas;
• medium in cutting area which is on or adjacent to an existing A90 cutting;
• medium in a transition embankment/cutting zone;
• low in a transition embankment/cutting zone where the cutting is on or adjacent to an existing A90 cutting; and
• negligible in an embankment area.

7.4.67 Signifiance of potential impacts on PWS on both quality and flow taking account sensitivity and magnitude are reported in Table 7.30. This indicates that the highest significance of potential impact are at S03 and S07 (Moderate).

Table 7.30: Summary of Potential Impacts Associated with PWS - South Corridor Option 2

PWS	Sensitivity	Potential impact on groundwater quality (unmitigated)		Potential Impact on groundwater flow (unmitigated)
		Magnitude	Significance	Magnitude	Significance
S01	Medium	Medium	Moderate	Negligible	Neligible/Slight
S02	Negligible	Medium/High	Slight	Medium	Negligible/Slight
S03	Medium	Medium/High	Moderate	Medium	Moderate
S04	Medium	Medium	Moderate	Negligible	Negligible/Slight
S05	Low	Medium/High	Moderate	Low	Slight
S06	Low	Medium/High	Moderate	Medium	Slight/Moderate
S07	Low	High	Moderate	High	Moderate

7.5 Potential Mitigation

7.5.1 At DMRB Stage 2 assessment of route corridor options the detailed design has not been developed and mitigation detail therefore cannot be accurately defined. The objective of this section is therefore to identify ‘standard’ or ‘anticipated’ mitigation taking into account best practice, legislation and guidance. This mitigation is taken into account in the subsequent identification of likely residual impacts in Section 7.4 (Potential Impacts), to provide a robust basis for comparative assessment and selection of a preferred route corridor option to be taken forward to Stage 3.

7.5.2 In order to determine the nature and extent of contamination present, soil and groundwater samples are being collected and analysed during the current geotechnical ground investigation. Where contamination is identified, a full assessment will be undertaken pre-construction to determine what mitigation, if any, is required. Mitigation measures may include removal of waste soils from site, consolidation of waste for treatment ex-situ or treatment of wastes in situ.

7.5.3 Where impacts on geologically important features and mineral extraction have been identified, further consideration with regards to engineering solutions which protect or preserve the feature concerned, will be required at DMRB Stage 3.

7.5.4 Although further investigation is required, potential mitigation measures with regards to the groundwater environment and public water supplies are summarised in paragraphs 7.5.5 to 7.5.7.

7.5.5 Prior to and during the construction and at the beginning of the operational phase, the following is proposed:

• Mitigation measures prior to the construction may include a programme of monitoring of the private water supplies to identify baseline conditions for groundwater. This baseline values will be useful to identify any impairment in the groundwater quality/quantity following the construction and at the beginning of the operational phase.
• The monitoring of PWS identified as being potentially at risk will provide a better understanding of groundwater flow and groundwater quality. This will enable the potential impact on private groundwater supplies to be determined with more accuracy, and mitigation developed as appropriate.
• Based on the groundwater monitoring and assessment, further mitigation measures may be proposed in relation to specific groundwater supplies. It may be necessary to undertake monitoring of selected groundwater supply sources during construction and into the start of the operational phase to assess whether there has been any discernible effect on the supply. If yields of water supplies are shown to be reduced, mitigation measures would be likely to include an alternative or replacement supply.
• Avoidance of areas of potential contamination and where necessary implementing specific measures to ensure that people and environment are not at risk from the mobilisation of contaminants.

7.5.6 During the construction phase, the following is proposed:

• Chapter 8 (Water Environment) lists anticipated mitigation to address potential impacts on surface waters, including adherence to SEPA Pollution Prevention Guidelines (PPGs) during construction, and appropriate highways drainage and treatment. These measures would also mitigate against water pollution risk to groundwater by reducing the potential for pollutant release and preventing any contaminated runoff produced by the works from entering groundwater via the unsaturated zone or via losing streams¹ that may recharge directly into the bedrock aquifers.
• Any contaminated waters will need to be removed for off-site disposal at an appropriate licensed facility in accordance with Waste Management Licensing Regulations 1994 (as amended), or treated on-site and discharged in compliance with a Consent to Discharge issued by SEPA.

7.5.7 During the operational phase, the following is proposed:

• Mitigation measures may include the lining of the road drainage to prevent accidental spillages and/or contaminated runoff form the road surface migrating to the unsaturated zone and reaching the groundwater.
• Appropriate drainage measures would be required for embankments to the east of St Margaret’s Marsh in order to preserve the hydrological balance of the Marsh (refer to Chapter 8: Water Environment). These mitigation measures will be defined after detailed investigations of the surface and sub-surface hydrological connectivity of the marsh.
• Mitigation measures to prevent any contaminated runoff from entering shallow groundwater which may be supporting St Margaret’s Marsh, or any other designated area (i.e. watercourse or pond), are the same as those identified in Chapter 8 (Water Environment).

7.6 Summary of Route Corridor Options Assessment

Northern Route Corridor Options

North Corridor Option 1

7.6.1 With regards to sites of geological/geomorphological importance and mineral extraction, North Corridor Option 1 is likely to have a lower impact than North Corridor Option 2 as it would remove the least area of land at the identified SSSI sites. The impact of road construction in areas associated with this route corridor will depend on the mitigation measures incorporated within the final design. Following application of ‘typical’ mitigation measures, the impacts on these sensitive areas by North Corridor Option 1 are of Negligible significance.

7.6.2 North Corridor Option 1 is at a significantly lower risk from contaminated land than North Corridor Option 2. With appropriate mitigation measures, the effect of contamination on the surrounding environment can be minimised.

7.6.3 North Corridor Option 1 crosses or is in the vicinity of areas of groundwater designated as highly vulnerable to pollution and, as such, is considered to have a greater vulnerability than North Corridor Option 2 in the groundwater environment. However, this potential impact would be greatly limited on this route corridor as this is mostly an online option and direct impacts would thus be limited. If the appropriate mitigation measures described in paragraphs 7.5.5 to 7.5.7 are implemented, the residual impacts on both groundwater quality and quantity are expected to be Negligible to Slight.

7.6.4 North Corridor Option 1 is considered the preferred option on account of its potentially lower impact on sites of geological/geomorphological importance and lower impact from contaminated land.

North Corridor Option 2

7.6.5 North Corridor Option 2 would have a higher impact on sites of geological/geomorphological importance and mineral extraction than North Corridor Option 1. The impact of road construction in areas associated with this route corridor will depend on the mitigation measures incorporated within the final design. It is likely that even after application of ‘typical’ mitigation measures, a Low to Moderate residual impact on sites of geological/geomorphological importance may remain for North Corridor Option 2.

7.6.6 North Corridor Option 2 is at the greatest potential risk from contaminated land, mainly as a result of the route corridor crossing the St. Margaret’s Marsh area and former landfill. As with North Corridor Option 1, with appropriate mitigation measures, the effect of contamination on the surrounding environment can be minimised.

7.6.7 North Corridor Option 2 was assessed to have a greater potential impact then North Corridor Option 1 on groundwater flow, water quality and on groundwater-supported habitats, in particular in the St. Margaret’s Marsh area. If the appropriate mitigation measures described in paragraphs 7.5.5 to 7.5.7 are implemented, the residual impacts on both groundwater quality and quantity are expected to be Negligible to Slight.

7.6.8 North Corridor Option 2 is considered the lesser preferred option on account of its potentially higher impact on sites of geological/geomorphological importance and higher impact from contaminated land, particularly in the St. Margaret’s Marsh area.

Southern Route Corridor Options

South Corridor Option 1

7.6.9 With regards to sites of geological/geomorphological importance and mineral extraction, no impacts have been identified for South Corridor Option 1.

7.6.10 South Corridor Option 1 is at a lower risk from potentially contaminated land than South Corridor Option 2.

7.6.11 South Corridor Option 1 is likely to have a similar potential impact to South Corridor Option 2 on the groundwater environment. As with the northern route corridor options, if the appropriate mitigation measures are implemented, the residual impacts on both groundwater quality and quantity are expected to be negligible to slight.

7.6.12 Overall, South Corridor Option 1 is considered the preferred option on account of its potentially lower impact from contaminated land.

South Corridor Option 2

7.6.13 With regards to sites of geological/geomorphological importance and mineral extraction, no impacts have been identified for South Corridor Option 2.

7.6.14 South Corridor Option 2 presents a higher risk than South Corridor Option 1 with regards to contaminated land. This is mainly as a result of the route corridor crossing areas where former oil shale mines are known to exist. With appropriate mitigation measures, the effect of contamination on the surrounding environment can be minimised.

7.6.15 South Corridor Option 2 is likely to have a similar potential impact to South Corridor Option 1 on the groundwater environment. As with the northern route corridor options, if the appropriate mitigation measures are implemented, the residual impacts on both groundwater quality and quantity are expected to be Negligible to Slight.

7.6.16 Overall, South Corridor Option 2 is considered the lesser preferred option on account of its potentially higher impact from contaminated land.

7.7 Scope of Stage 3 Assessment

7.7.1 In accordance with DMRB Volume 11, further assessment of the preferred route corridor will be undertaken to refine the identification of any significant impact on geology, soils and groundwater and where appropriate any particular environmental issues associated with contaminated land. It is proposed that the following steps will be taken:

• confirm information gathered from relevant statutory bodies and the local planning authority, and in particular gather views on the hydrological–hydrogeological relationships for functioning of the SSSI and water features of importance as highlighted in Stage 2;
• review and assess the results of the geological ground investigation work currently underway, which will refine the information regarding geology and soil of the study area;
• review and assess the results of contaminated land tests currently underway in targeted made ground areas determined from Stage 2 assessment;
• review and assess the results of hydrogeological ground investigation work to refine drift and bedrock groundwater characteristics;
• undertake consultation with private land owners regarding PWS, and undertake further assessment in areas defined by SEPA as a Drinking Water Zone at Stage 2;
• potentially undertake additional surveys of potentially contaminated sites and key private water supplies; and
• propose appropriate mitigation measures based on refined assessments.

7.8 References

BGS (1962) Solid Geology NT17NW 1:10560

BGS (1962b) Solid Geology NT18NW 1:10560

BGS (1963) Solid Geology NT07NE 1:10560

BGS (1963b) Solid Geology NT17NE 1:10560

BGS (1966) Solid geology NT18SW 1:10560

BGS (1966b) Solid Geology NT17NW 1:10560

BGS (1986) Hydrogeological Map of Fife & Kinross scale 1: 100 000

BGS (1988) Dunfermline NT18SW Map 1: Drift Lithology 1:10000

BGS (1988b) Dunfermline NT18SW Map 2: Drift Thickness1:10000

BGS (1988c) Dunfermline NT18SW Map 3: Bedrock Geology 1:10000

BGS (1988d) Hydrogeological Map of Scotland scale 1: 625 000

BGS (1989) Drift Geology NT18SW 1:10000

BGS (1992) Geology for Land Use Planning: Livingston Map 1 - Drift Lithology 1:25000

BGS (1992b) Geology for Land Use Planning: Livingston Map 2 - Drift Thickness 1:25000

BGS (1992c) Geology for Land Use Planning: Livingston Map 3 - Bedrock Geology 1:25000

BGS (1992d) Geology for Land Use Planning: Livingston Map 4 - Mining Information 1:25000

BGS (1992e) Geology for Land Use Planning: Livingston Map 5 - Geological factors relevant to land use planning 1:25000

BGS (1994) Drift Geology NT17NW 1:10000

BGS (1995) Groundwater Vulnerability Map of Scotland scale 1:625 000

BGS (2004) A GIS of aquifer productivity in Scotland: explanatory notes. Commissioned Report CR/04/047N

Carl Bro (1998) Setting Forth Studies - Library of Working Papers 1993-1998

CIRIA (2001) Contaminated Land Risk Assessment – A Guide to Good Practice (C552)

Coal Authority (2008) Coal Mining Report Marine, Fife 00033855-08

Coal Authority (2008b) Coal Mining Report North Queensferry, Fife 00006594-08

Coal Authority (2008c) Coal Mining Report Inverkeithing, Fife 00033850-08

Coal Authority (2008d) Coal Mining Report Masterton to Halbeath, Fife 00006595-08

Coal Authority (2008e) Coal Mining Report Halbeath, Fife 00033835-08

Coal Authority (2008f) Coal Mining Report Dalmeny, Lothian 00006593-08

Coal Authority (2008g) Coal Mining Report Echline and Dalmeny to South Queensferry, Midlothian 0033923-08

Coal Authority (2008h) Coal Mining Report Humbie, Midlothian 00033852-08

Coal Authority (2008i) Coal Mining Report South Queensferry, Lothian 00006592-08

DEFRA (2002) Potential Contaminants for the Assessment of Contaminated Land: Contaminated Land Report (CLR) No. 8

Envirocentre (2003) Survey of Contaminated Land Preliminary (Phase 1) Contaminated Land Report: St. Margaret’s Bay, Rosyth for Fife Council Report No. 1271

ENVIRON UK Ltd. (2007) Groundwater Monitoring Report March 06-March 07 Castle Key, Rosyth R62C11325_2

Envirocentre (2004) Survey of Contaminated Land (Phase II) Intrusive Investigation Report: St Margaret’s Bay for Fife Council Report No. 1652

Jacobs et al. (2007) Forth Replacement Crossing Study Initial Desk Study Report for Transport Scotland.

SEPA (2008) Pollution Prevention Guidelines (PPGs) http://www.netregs.gov.uk/netregs/resources/278006/277807/?version=1&lang=_e – Accessed 20th May 2008

SNH(2008) Site-link environmental database http://gateway.snh.gov.uk/portal/page?_pageid=53,910284,53_920284&_dad=portal&_schema=PORTAL Accessed 23rd May 2008

The Highways Agency et al. (1993) DMRB Volume 11 Geology and Soils, Section 3, Part 11, June 1993. The Highways Agency, Scottish Executive Development Department, The National Assembly for Wales and The Department of Regional Development Northern Ireland.

Ordnance Survey Maps

(1853) Edinburghshire 1:10560	(1957) OS Plan NT17NW and NT17SW 1:10560
(1855) Linlithgowshire 1:2500	(1958) OS Plan NT18 NW and NT18SW 1:10560
(1856) Fifeshire 1:10560	(1961) OS Plan NT18 NW and NT18SW 1:2500
(1856b) Linlithgowshire 1:10560	(1963) OS Plan NT17NW and NT17SW 1:2500
(1856c) Linlithgowshire 1:2500	(1967) OS Plan NT18 NW and NT18SW 1:2500
(1882) Linlithgowshire 1:2500	(1968) OS Plan NT18 NW and NT18SW 1:10560
(1895) Edinburghshire 1:2500	(1968b) OS Plan NT17NW and NT17SW 1:10560
(1896) Fifeshire 1:2500	(1973) OS Plan NT17NW and NT17SW 1:2500
(1897) Fifeshire 1:10560	(1978) OS Plan NT17NW and NT17SW 1:2500
(1897b) Linlithgowshire 1:10560	(1979) OS Plan NT17NW and NT17SW 1:10000
(1897c) Linlithgowshire 1:2500	(1981) OS Plan NT18 NW and NT18SW 1:10000
(1898) Linlithgowshire 1:10560	(1984) OS Plan NT18 NW and NT18SW 1:10000
(1907) Edinburghshire 1:2500	(1984b) OS Plan NT17NW and NT17SW 1:10000
(1909) Edinburghshire 1:10560	(1985) OS Plan NT17NW and NT17SW 1:2500
(1915) Fifeshire 1:2500	(1986) OS Plan NT17NW and NT17SW 1:2500
(1915b) Linlithgowshire 1:2500	(1989) OS Plan NT18 NW and NT18SW 1:2500
(1915c) Edinburghshire 1:10560	(1990) OS Plan NT18 NW and NT18SW 1:10000
(1917) Linlithgowshire 1:2500	(1993) Large Scale National Grid Data NT18 NW and NT18SW 1:2500
(1921) Fifeshire 1:10560	(1993b) Large Scale National Grid Data NT18 NW and NT18SW 1:1250
(1922) Linlithgowshire 1:10560	(1995) OS Plan NT18 NW and NT18SW 1:10000
(1923) Linlithgowshire 1:10560	(1995b) Large Scale National Grid Data NT17NW and NT17SW 1:2500
(1927) Fifeshire 1:2500	(1995c) OS Plan NT17NW and NT17SW 1:10000
(1927b) Fifeshire 1:10560	(1999) 10K Raster Mapping NT17NW and NT17SW 1:10000
(1938) Fifeshire 1:10560	(2000) 10K Raster Mapping NT18 NW and NT18SW 1:10000
(1938b) Edinburghshire 1:10560	(2007) 10K Raster Mapping NT18 NW and NT18SW 1:10000
(1951) Linlithgowshire 1:10560	(2007b) 10K Raster Mapping NT17NW and NT17SW 1:10000