GEOLOGY AND THE WATER ENVIRONMENT 9
CONTENTS
Introduction ...... 9-1 Scoping and Consultation ...... 9-1 Planning Policy & Regulatory Framework ...... 9-3 Policy Context ...... 9-3 Assessment Methodology ...... 9-6 Sources of Information ...... 9-8 Baseline Overview ...... 9-9 Soils and Geological Setting ...... 9-10 Hydrogeological Setting ...... 9-12 Hydrological Setting and Flood Risk ...... 9-19 Summary of Potential Receptors ...... 9-26 Assessment of Effects ...... 9-27 Summary of the Proposed Development ...... 9-27 Mitigation by Design ...... 9-30 Potential Effects ...... 9-34 Proposed Mitigation ...... 9-37 Residual Effects ...... 9-37 Cumulative Effects ...... 9-37 Conclusions ...... 9-37
Appendices
Appendix 9/1 Non Residential coal Authority Mining Report Appendix 9/2 Licensed Abstractions
Drawings
Drawing TL9/1 Local Hydrology Drawing TL9/2 Superficial Geology Drawing TL9/3 Solid Geology Drawing TL9/4 Generalised Vertical Section and Proposed Exploratory Well Construction Details Drawing TL9/5 Hydrogeological Map Drawing TL9/6 Regional Hydrogeology
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INTRODUCTION
9.1 This chapter considers the potential for the proposed exploratory well at Tinker Lane to impact the geology and water environment in the vicinity of the well.
9.2 The water environment refers in principal to hydrogeology, hydrology and flood risk, although details of the regional and local geology have also been provided to aid in understanding the site setting in relation to its hydrology and hydrogeology.
9.3 The assessment is based on a detailed baseline description of the local and regional geological, hydrogeological, hydrological and flood risk regimes. This is followed by an assessment of potential significant effects, a review of appropriate mitigation measures and an assessment of cumulative impacts.
9.4 Prior to preparing this assessment a detailed site walkover survey was undertaken by a SLR Technical Director who specialises in geological, hydrogeological and hydrological assessments. SCOPING AND CONSULTATION
9.5 A scoping opinion has been submitted by Nottinghamshire County Council and comments relating to the water environment and flood risk are summarised in Table 9-1.
Table 9-1 Summary of Scoping Opinion Responses Consultee Summary of Response Date of Response Coal Authority The proposed Tinker Lane 1 Exploratory Well would be 17th located within the defined coalfield, but outside the November Development High Risk Area. No Coal Mining risk 2015 assessment would be required.
Given that the proposals are likely to result in drilling activities to significant depth the proposed well would be located within a licence area of past underground coal mining activity. Due consideration needs to be afforded to the potential for these deep drilling activities to intersect old underground coal mine workings and the need for these drilling activities to be undertaken safely.
Public Health When considering a baseline (of existing water quality) 19th England and in the assessment and future monitoring of impacts November these: 2015 Should include assessment of potential impacts on human health and not solely focus on ecological impacts; Should identify and consider all routes by which emissions may lead to population exposure (e.g. surface watercourses, recreational waters, sewers,
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Consultee Summary of Response Date of Response geological routes etc.) Should assess the potential off-site effects of emissions to groundwater (e.g. on aquifers used for drinking water) and surface water (used for drinking water abstraction) in terms of the potential for population exposure. It should be considered that controlled surface waters may be affected by surface activities or by lateral migration of contaminants in groundwater. Should include consideration of potential impacts on recreational users (e.g. from fishing, canoeing etc.) alongside assessment of potential exposure via drinking water. Details of any hazardous contamination present on site (including ground gas) as part of the site condition report. Nottinghamshire The County archive does not indicate the presence of any 29th County Council contaminative former land use, nor does the archive October (Landscape and indicate the presence of landfill. However it is known that 2015 Reclamation) a former MOD establishment was located some 1.8km to the north-east.
Whilst no readily identified environmental risks have been identified it is considered most prudent to undertake a more comprehensive search of data archives to validate the greenfield status or otherwise of the site.
A conceptual site model should be developed for the site and should be developed through the preparation of the Phase 1 desk study to assess the environment and human health risks posed by the pollutant linkages at the site. Health and It is recommended that the following information is 28th Safety submitted in the ES: October Executive - A stratigraphic column describing the age and 2015 types of formation to be drilled with depths; - Locations of proposed monitoring boreholes; - A schematic of proposed monitoring boreholes; - A schematic of the exploratory borehole; - The likelihood of lost circulation whilst drilling; - If possible, a list of the likely mud and cement chemicals; and - Proposed monitoring procedures. Environment Hazardous substances must be prevented from entry into 25th Agency ground and surface water and the entry into groundwater November of all other pollutants must be limited to prevent pollution. 2015
These environmental considerations should be addressed during the development, construction and operational/appraisal phases of this proposal.
Table 4-1 of the Scoping Report (IGAS Reference 402.05891.0001 October 2015) identifies the significant environmental topics to be addressed by the Environmental Statement. We agree that the
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Consultee Summary of Response Date of Response Environmental Statement should consider potential effects from pollution of surface and groundwater from site operations, siting of and alteration of catchment areas and surface water flows.
The Environment Agency would also expect the EIA to consider the following:
- cumulative, short, medium and long term effects on water and land. Permanent and temporary effects should also be addressed - description of the management of the development to prevent soil and water contamination - the requirement for water during the operation and the percentage of water that will be re-used or recycled - hydrogeological risk assessment of the potential impacts on groundwater and surface water, including impacts on any aquifers or groundwater sensitive receptors - monitoring and site management plan
The Environment Agency would recommend undertaking a desk study for the site as a minimum and establishing the baseline quality of the land.
We note the proposals to construct up to three sets of monitoring boreholes to sample groundwater and gas. We would like to review the detail of these proposals as they become available.
The investigation for and eventual exploitation of hydrocarbon minerals will require several permits from the Environment Agency, the exact nature of these will vary depending on what activities are proposed, as such we recommend early engagement with the Environment Agency regarding the permitting process.
9.6 The scoping responses received have informed the scope and content of this assessment.
9.7 In addition to the scoping exercise details of local water use, water quality and flood risk have been obtained from the Environment Agency and Bassetlaw District Council. PLANNING POLICY & REGULATORY FRAMEWORK
Policy Context
9.8 A discussion of planning policy that relates to the proposed development is outlined in Chapter 4. Summary details that are relevant to this Chapter are presented below.
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European Legislation
9.9 The key piece of European Legislation that protects the UK’s water environment is the Water Framework Directive (WFD). This Directive protects all elements of the water cycle and seeks to enhance the quality of groundwaters, surface waters, estuaries and coastal waters.
National Legislation and Policy
9.10 The Water Resources Act 1991 is supported by:
the Environment Act 1995 which established the Environment Agency; and the Environmental Protection Act 1990 which provides for integrated pollution control.
9.11 The Water Act 2003 governs the control of water abstraction, discharge to water bodies, water impoundment, conservation and drought provision.
9.12 A number of specific regulations have also been implemented to enact the statutory law as set out above. These regulations include:
the Anti-Pollution Works Regulations 1999; the Control of Pollution (Oil Storage) (England) Regulations 2001; Water Resources (Environmental Impact Assessment) (England and Wales) Regulations 2003; the Environmental Damage Regulations 2009; the Water Resources Act (Amendment) (England & Wales) Regulations 2009; the Environmental Permitting (England and Wales) Regulations 2010 which control discharge of water to surface water and groundwater and which incorporates the Groundwater Regulations (England and Wales) 2009 which transposed the EU Groundwater Directive 2006 (2006/118/EC) into UK law; and Water Supply (Water Quality) Regulations 2010.
9.13 Further, the Flood and Water Management Act (2010) and Water Act (2014) provides flood risk, drainage and water resilience regulation.
9.14 The National Planning Policy Framework (NPPF) supersedes and replaces a number of planning policy documents that are applicable to the water environment and sets out 12 core planning principles as guidance for local councils for the preparation of their local plan and in making planning decisions; the following principles are directly applicable to the water environment: meeting the challenge of climate change, flooding and coastal change – support the transition to a low carbon future in a changing climate taking full account of (inter alia) flood risk and coastal change; and
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conserving and enhancing the natural environment – development should minimise pollution and other adverse impacts on the local and natural environment and should plan positively for the creation, protection, enhancement and management of networks of biodiversity and green infrastructure.
9.15 The Environment Agency in their Groundwater Protection: Principles and Practice (2013) guidance state a Position Statement (C6) on unconventional gas and confirms the regulator's approach to groundwater protection, as follows:
‘We wish to facilitate development of sustainable sources of energy, working in partnerships on initiatives where appropriate. However, we will object to UCG, CBM or shale gas extraction infrastructure or activity within Source Protection Zone 1 (SPZ1).
Outside SPZ1, we will also object when the activity would have an unacceptable effect on groundwater. Where development does proceed, we expect BAT to protect groundwater to be applied where any associated drilling or operation of the exploratory wells/shafts passes through a groundwater resource.
Elsewhere, established good practice should be followed. Groundwater that is currently used as a resource or provides flow to surface waters and wetlands, or may be used as a resource in the future must be afforded a high degree of protection. A high level of protection will also extend to some deep formations that contain groundwater that would be suitable for use following treatment if necessary, or that may be used for artificial storage and recovery. For other formations groundwater must also be protected but we would not seek to apply the same degree of protection.
9.16 The Environment Agency published for consultation draft guidance for the Onshore Oil and Gas Sector in November 2015. The draft guidance details which environmental permits may be required from the Environment Agency for onshore oil and gas operations in England and includes guidance for the following activities: well pad construction, drilling exploratory wells, flow testing and well stimulation, and storing and handling of water, flowback fluid and extractive wastes. The consultation period ended in March 2016 and it is understood that the final version of the guidance will be published in 2016.
9.17 In addition there is much guidance that considers best practice construction and operation, pollution prevention and flood risk management. Reference to this information, where relevant, is made in the Sections that follow.
Local Planning Policy and Strategy
9.18 The Adopted Minerals Plan sets out the County Council’s approach to future mineral extraction and of relevance to this Chapter Policy M3.8: Water Environment states:
‘Planning permission for minerals development will only be granted where (a) surface water flows are not detrimentally altered, (b) groundwater levels,
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where critical, are not affected; and (c) there are no risks of polluting ground or surface waters. Unless engineering measures and/or operational management systems can adequately mitigate such risks.’
Environmental Permitting Regulations
9.19 The Environmental Permitting (England and Wales) Regulations 2010 (as amended) regulate a range of ‘activities’ proposed at the site. Pre-application discussions with the Environment Agency (EA) will determine which activities are relevant to this site and require environmental permitting. The Water Resources Act 1991 also requires operators to notify the Environment Agency of their intention to drill a well, such that the Agency can review the proposals to ensure that water resources are safeguarded.
ASSESSMENT METHODOLOGY
9.20 A qualitative risk assessment methodology has been used to assess the significance of the potential effects associated with the proposed development. Two factors have been considered using this approach: the sensitivity of the receiving environment and the potential magnitude of impact, should that potential impact occur.
9.21 This approach provides a mechanism for identifying the areas where mitigation measures are required, and for identifying mitigation measures appropriate to the risk presented by the scheme. This approach also allows effort to be focused on reducing risk where the greatest benefit may result.
9.22 Criteria for determining the significance of effects are provided in Table 9-2, Table 9-3 and Table 9-4 below. Effects of ‘major’ and ‘moderate’ significance are considered to be ‘significant’ in terms of the EIA Regulations.
9.23 The sensitivity of the receiving environment (i.e. the baseline quality of the receiving environment as well as its ability to absorb the impact without perceptible change) is defined in Table 9-2.
Table 9-2 Sensitivity Criteria for Geological and Water Environment Receptors Sensitivity Definition International importance Very High Receptor with a high quality and rarity, regional or national scale and limited potential for substitution / replacement National importance. Receptor with a high quality, local scale and limited potential for High substitution / replacement; or Receptor with a medium quality and rarity, regional or national scale and limited potential for substitution / replacement. Regional importance Receptor with a medium quality and rarity, local scale and limited Medium potential for substitution / replacement; or Receptor with a low quality and rarity, regional or national scale and limited potential for substitution / replacement.
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Sensitivity Definition Local importance Receptor with a low quality and rarity, local scale Low Environmental equilibrium is stable and is resilient to changes that are greater than natural fluctuations, without detriment to its present character.
9.24 The criteria that have been used to assess the magnitude of the impacts are defined in Table 9-3.
Table 9-3 ‘Magnitude of Impact’ Criteria and Definitions Magnitude Criteria Definition Fundamental (long term or permanent) changes to geology, hydrology, hydrogeology and water quality, such as: Permanent degradation and total loss of the soil habitats Loss of important geological structure/features Wholesale changes to watercourse channel, route, Results in hydrology or hydrodynamics loss of Major Changes to the application site resulting in an increase in attribute runoff with flood potential and also significant changes to erosion and sedimentation patterns Major changes to the water chemistry or hydro-ecology Major changes to groundwater levels, groundwater resource, flow regime and risk of groundwater flooding. Material but non-fundamental and short to medium term changes to geology, hydrology, hydrogeology and water quality, such as: Loss of extensive areas of, damage to important geological Results in structures/features impact on Some fundamental changes to watercourses, hydrology or integrity of hydrodynamics. Changes to site resulting in an increase in Moderate attribute or runoff within system capacity. loss of part of Moderate changes to erosion and sedimentation patterns attribute Moderate changes to the water chemistry of surface runoff and groundwater Moderate changes to groundwater levels, groundwater resource, flow regime and risk of groundwater flooding. Detectable but non-material and transitory changes to geology, hydrology, hydrogeology and water quality, such as: Minor or slight loss of soils or slight damage to geological structures / features Minor or slight changes to the watercourse, hydrology or Results in hydrodynamics Minor minor impact Changes to site resulting in slight increase in runoff well on attribute within the drainage system capacity Minor changes to erosion and sedimentation patterns Minor changes to the water chemistry of surface runoff and groundwater Minor changes to groundwater levels, groundwater resource, flow regime and risk of groundwater flooding.
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Magnitude Criteria Definition No perceptible changes to geology, hydrology, hydrogeology and water quality, such as: Results in an No impact or alteration to existing important geological impact on environs attribute but No alteration or very minor changes with no impact to of insufficient Negligible watercourses, hydrology, hydrodynamics, erosion and magnitude to sedimentation patterns affect the No pollution or change in water chemistry to either use/integrity groundwater or surface water No alteration to groundwater recharge or flow mechanisms.
9.25 The sensitivity of the receiving environment together with the magnitude of the impact defines the significance of the potential impact, as identified within Table 9-4, below. Where the significance of geological, hydrological or hydrogeological impact has been classified as Major, this is considered to be equivalent to a significant effect referred to in the EIA Regulations.
Table 9-4 Significance of Potential Impact
Magnitude Sensitivity of Impact Very High High Medium Low Major Major Major Moderate Minor Moderate Major Moderate Moderate Minor Minor Minor Minor Minor Negligible Negligible Negligible Negligible Negligible Negligible
SOURCES OF INFORMATION
9.26 The following information sources have been used to characterise the site and its geological, hydrogeological and hydrological setting: Geology and Soils
British Geological Survey (BGS) online maps (www.bgs.ac.uk/data/mapViewers/home.html) for details of geology, borehole logs and groundwater classifications; BGS East Retford Geology Sheet 101, Solid and Drift Published 1967; BGS Geology of the country around East Retford, Geological Survey of Great Britain, 1973; The Carboniferous Bowland Shale Gas Study: Geology and Resource Estimation British Geological Survey, Department of Energy & Climate Change December 2013; National Soils Resource Institute Website for details on soils (https://www.landis.org.uk/soilscapes/); Site specific Coal Mining Report, 23rd November 2015 Report No. 51001038756001 (see Appendix 9/1);
Water Environment
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Environment Agency Website (www.environment-agency.gov.uk) for details on aquifer classification, source protection zones, groundwater vulnerability, flood risk and Water Framework Directive classifications for groundwater, rivers and coast; Institute of Hydrology Flood Estimation Handbook CD ROM Version 3, 2009; Natural England Website for details on groundwater and surface water dependent designated sites; (http://www.natureonthemap.naturalengland.org.uk); Nottinghamshire Wildlife Trust website for details on the designation of local ecological sites (http://www.nottinghamshirewildlife.org/nature- reserves/daneshill-gravel-pits) Environment Agency Information Request Response (dated 30th October 2015) providing details of licensed abstractions, discharges, environmental monitoring data including surface water flows and quality, groundwater quality and rainfall data; MetOffice Website for 1981 – 2010 climate average for Robin Hood Airport (http://www.metoffice.gov.uk/public/weather/climate) Correspondence with Bassetlaw District Council (dated 2nd November 2015) regarding private water supplies; Centre for Ecology and Hydrology National River Flow Archive (NRFA) website for details of flows within local watercourses (http://nrfa.ceh.ac.uk/data/station/meanflow/28091) Details of the proposed exploration well and site area provided by IGas Energy plc; BGS, 1997, The Physical Properties of Major Aquifers in England and Wales, ref: WD/97/34; Environment Agency, Feb 2013, Idle and Torne Abstraction Licensing Strategy Environment Agency, Dec 2009, River Basin Management Plan: Humber River Basin District; and Environment Agency, Oct 2015, Humber River Basin District: River Basin Management Plan (2015 proposed update). BASELINE OVERVIEW
9.27 The geology and water environment is considered in a number of sections: Geological Setting: provides an overview of local and regional superficial and geological conditions Hydrogeological Setting: provides an overview of recharge mechanisms, aquifer characteristics, groundwater levels and flow, groundwater quality and potential groundwater receptors including abstractions and groundwater dependent ecological sites (GWDEs) Hydrological Setting: provides an overview of surface water features, flows, quality, abstractions and discharges and flood risk and surface water management.
9.28 This information has been used to develop a conceptual site model to assess potential impacts associated with the proposed development. The model has also been used to identify appropriate mitigation measures.
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9.29 The site location and local hydrological setting is shown on Drawing TL9/1.
Soils and Geological Setting
9.30 BGS mapping1 indicates that the proposed exploratory well is located upon Triassic Sandstone bedrock formation known as the Nottingham Castle Sandstone Formation with no recorded superficial deposits.
9.31 The regional superficial and bedrock geology is presented on Drawings TL9/2 and TL9/3.
Soils
9.32 Review of the Cranfield University Soilscapes website2 indicates that the soils across the proposed development area are classified as “Freely draining slightly acid sandy soils”. The soils are typified as having a low fertility and are freely draining to underlying groundwater.
9.33 The free draining and sandy nature of the soils was confirmed by the site walkover survey.
9.34 Review of historic mapping3 confirms that between 1885 and 1961 the site has been recorded as Greenfield. The site walkover survey confirmed that the site remains undeveloped today and is used for arable farming.
9.35 There are extensive current and historic sand and gravel workings to the east of the site; all are more than 1.5km from site.
9.36 Historic and current mapping does not reference the reported MOD facility recorded in the scoping response from Nottinghamshire County Council. It is noted in their response the MOD facility is located 1.8km north-east from the site.
9.37 Given the site has not been previously developed and the distance from site to areas of historic and current development, it is considered very unlikely that any existing ground or groundwater pollution is present at site.
Superficial Geology
9.38 The BGS 1:50,000 scale mapping (East Retford Sheet 1014) indicates that superficial deposits are limited to low-lying land regionally, and typically bound the main watercourse corridors such as the River Ryton to the north and west of the site, and the lower lying area to the east of the site around Sutton Cum Lound and Daneshill.
1 British Geological Survey Website (Accessed 17/11/15) http://mapapps.bgs.ac.uk/geologyofbritain/home.html 2 www.landis.org.uk/soilscapes 3 envirocheck 4East Retford Geology Sheet 101, Solid and Drift Published 1967. The map sheet has been photographically enlarged from 1:63,360 to 1:50,000
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9.39 No superficial deposits are shown to be present at the site. Bedrock is therefore anticipated at or close to surface.
Bedrock Geology
9.40 The BGS 1:50,000 scale mapping of East Retford (Sheet 101) illustrates the site is underlain by the Nottingham Castle Sandstone, comprising sandstones, mudstones, limestones, dolomite and conglomerates5. The Nottingham Castle Sandstone in turn overlies Permian and Carboniferous strata.
9.41 The geology of the local area and of the application site has been subject to much review and interpretation by IGas. The anticipated vertical geological section for the proposed exploratory well is shown as Drawing TL9/4, a review of which confirms: the Nottingham Castle Sandstone, approximately 100m thick beneath the site; underlying the sandstone is the Magnesian Limestone of the Permian geological era, which is likely to be about 150m thick; below the Magnesian Limestone lies an alternating sequence of mudstones, shales, sandstones and coals associated with the Carboniferous Coal Measures which are expected to be about 1000m thick; Carboniferous Millstone Grit, Bowland Shale and limestones lie below the Coal Measures and are about 1700m thick; basement rocks lie beneath the Carboniferous limestones at a depth of about 3100m.
9.42 The exploratory well has two main targets: Primary target : Bowland Shale (expected to be c.70m thick); and Secondary target: Millstone Grit Group shales and tight sands (expected to be about 300m thick).
9.43 The well has been designed for logging of the geological sequence beneath the site and potentially for micro seismic monitoring in the future. No other development is proposed.
9.44 It is proposed that the exploratory well is drilled to approximately 50m below the top of the Carboniferous Limestone, which underlies the Bowland Shale.
Mining
9.45 The proposed exploratory well will intersect a significant sequence of the Westphalian Coal Measures as evidenced from a Coal Mining report6 (see Appendix 9/1), the Coal Authority Interactive Map Viewer7 and geological
5 Geology of the country around East Retford, Geological Survey of Great Britain, 1973. 6 Coal Mining Report, 23rd November 2015 Report No. 51001038756001 7https://www.gov.uk/guidance/using-coal-mining-information#coal-authority-interactive-map- viewer
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mapping. Review of these sources confirms that the site is not within the zone of influence on the surface from past underground workings, neither is it in the zone of influence of any present underground workings. Specifically: There are no known coal mine entries within 20 metres of the site boundary and there is no record of any gas emissions requiring action within the boundary of the site.
The site is not within an area from which coal has been removed by opencast methods, is being removed or where a licence exists to extract coal by opencast methods in the future.
There are no records of historic or current deep coal workings below the site.
9.46 It is noted that the site is within area for which a licence to remove or otherwise work coal using underground methods was granted in October 1994.
9.47 In summary, the site has not been effected by current or historic mining (surface or deep) and the proposed exploratory well would not intercept any current or historic areas of deep coal mining.
Hydrogeological Setting
Recharge Mechanisms
9.48 The Met Office 1981 – 2010 climate average for Robin Hood airport8, located c.10km north-east of the site, indicates that the average annual rainfall for the area is 574.5mm
9.49 The Environment Agency maintains two rainfall gauges within a 10km radius of the proposed site, located at: Wiseton: Daily rainfall gauge (tipping bucket) located c.9.4km north-east of the site. Monitoring data from 1997 to 2015; and Worksop Manton: Tipping bucket rainfall gauge located c.8.5km south- west of the site. Monitoring data from 1983 to 2015.
9.50 A summary of the monthly rainfall data recorded at each of these gauges is presented in Table 9-5 and confirms the long term average rainfall total reported by the Met Office at Robin Hood Airport.
Table 9-5 Summary of Average Monthly Rainfall
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Wiseton1 47.3 35.2 31.8 45.2 44.6 60.6 59.9 61.1 42.7 61.0 53.0 48.9 597.7
8 Met Office Website (Accessed 17/11/15): http://www.metoffice.gov.uk/public/weather/climate/gcxb2fg7z
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Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Worksop 47.8 36.2 34.1 48.3 45.9 58.6 48.3 53.8 40.5 57.6 53.3 52.7 565.0 Manton2 Note: 1 Wiseton Data from 17/12/1997 to 19/10/15 2 Worksop Manton data from 04/01/1983 to 21/10/15 All values given in mm
Aquifer Characteristics and Groundwater Vulnerability
9.51 As detailed above, the proposed exploratory well will be drilled through a sequence of Permian, Triassic and Carboniferous formations which progressively outcrop to the west of the application site. The ultimate target unit, the Dinantian limestone rocks, outcrop in the Pennines, lies approximately 40km to the south-west of the proposed site.
9.52 The Environment Agency classification9 for each of the strata that will be encountered by the exploratory well is summarised in Table 9-6. Reference is also made to the BGS hydrogeological map (see Drawing TL9/5).
Table 9-6 Summary of Aquifer Designation
Age Strata Sub-Strata Aquifer Aquifer Description Classification1 Sherwood Nottingham Principal Medium to coarse grained pebbly sandstone Sandstone Castle Sandstone becoming very fine to medium grained Lenton Sandstone Principal sandstone at base. High Intergranular flow with potentially high
yields.
Zechstein Roxby Formation Secondary B Mudstones and siltstones with subordinate Group sandstones. Unit forms an aquitard between sandstone and limestone aquifers, some minor groundwater within any sandstone horizons
Magnesian Brotherton Principal Limestone aquifers divided by mudstones of PermianTriassic & Limestone Formation the Edlington Formation which acts as a Edlington Secondary B leaky aquitard between the two units. Formation Groundwater flow predominantly through Cadeby Principal fracture flow within the limestone with Formation significant regional variability
Westphalian Westphalian C Secondary A Extensive sequence of coal measures Coal Measures consisting of cyclical sandstone, siltstone,
ferous mudstone and coal seams Carboni
9 Environment Agency Website (Accessed 17/11/15) http://apps.environment-agency.gov.uk/wiyby/ Principal Aquifer: ‘layers of rock which have high intergranular and/or fracture permeability – meaning they usually provide a high level of water storage. They may support water supply and/or river baseflow on a strategic scale’; Secondary A Aquifer: ‘permeable layers capable of supporting water supplies at a local rather than strategic scale, and in some cases forming an important source of baseflows to rivers’; Secondary B Aquifer: ‘Predominantly lower permeability layers which may store and yield limited amounts of groundwater due to localised features such as fissures, thin permeable horizons and weathering’; and Secondary (Undifferentiated) Aquifer: ‘assigned in cases where it has not been possible to attribute either category A or B to a rock type. In most cases this means that the layer in question has previously been designated as both minor and non-aquifer in different locations due to the variable characteristics of the rock type.
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Age Strata Sub-Strata Aquifer Aquifer Description Classification1 Westphalian B Secondary A Groundwater flow limited to the higher permeability sandstone and coal horizons, flow potentially altered by presence of historic coal mining where present Westphalian A Secondary A Millstone Grit Millstone Grit Secondary A Fine to very coarse sandstones, interbedded with grey siltstones and mudstones Intergranular flow primarily within the sandstone horizons Bowland Shale Bowland Shale Secondary Dark grey fissile and blocky mudstone with (Undifferentiated) subordinate limestone and sandstone Primarily unproductive strata, however limited groundwater potentially present with limestone and sandstone horizons Carboniferous Carboniferous Principal Limestone aquifer with potentially high Limestone Limestone secondary permeability. (Dinantian Rocks) Note: 1 Taken from Environment Agency Aquifer Designation maps at outcrop. Given the depth to Coal Measures, Millstone Grit, Bowland Shale and Carboniferous Limestone beneath the site these units are considered as aquifers locally.
9.53 The near surface Nottingham Castle Sandstone (Sherwood Sandstone) is a regionally important ‘principal aquifer’ which provides both baseflow to the major watercourses in the area (e.g. River Idle and River Torne) and is an important source of potable water supplies.
9.54 The Nottingham Castle Sandstone is described by the BGS10 as “Sandstone, pinkish red or buff-grey, medium to coarse grained, pebbly, cross-bedded, friable; subordinate lenticular bands of reddish brown mudstones”. The strata directly overlies the Lenton Sandstone which is described as ‘Sandstone, very fine to medium grained’.
9.55 Groundwater flow within the Nottingham Castle and Lenton sandstones is predominantly intergranular with secondary flow possible within fractures and fissures associated with localised faulting11. Groundwater flow follows the regional dip in the strata, which dips to the east at between 1o and 2o, sloping beneath the Mercia Mudstone to the east where it becomes confined.
9.56 A significant number of investigations have been undertaken regionally in the Sandstones which confirm that they are slightly anisotropic with a typical horizontal hydraulic conductivity of between 0.73m/day and 5.5m/day and vertical conductivity of between 0.13m/day and 3.8m/day and typical transmissivities are in the region of 100m2/day and 700m2/day11.
9.57 Although the Nottingham Castle Formation and Lenton Sandstone are classified as separate geological units from a hydrogeological perspective the two strata act as a single unit and are therefore classified as a single aquifer.
10 British Geological Survey Website (Accessed 17/11/15) http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=NTC 11 British Geological Survey (1997) The physical Properties of Major aquifers in England and Wales, Ref: WD/97/34
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9.58 The Roxby formation which underlies the Nottingham Castle and Lenton Sandstone formations is described by the BGS as “mudstones and siltstone, reddish brown, with subordinate sandstone”. The unit acts as an aquitard between the overlying sandstone aquifer and underlying Magnesian Limestones aquifers.
9.59 The Magnesian Limestone consists of two principal limestone aquifers (Brotherton Formation and Cadeby Formation) separated by low permeability mudstones of the Edlington Formation. The limestones are described by the BGS as: Brotherton Formation: “Dolomitic Limestone, grey with abundant Calcinema”. The limestone is estimated to be up to 20m thick locally.
Cadeby Formation: “Dolostone, grey to buff grey, commonly oolitic or granular, with subordinate mudstone, dolomitic siltstone and sandstone”. The unit is estimated to be up to 100m thick locally.
9.60 The limestone outcrops approximately 4km to the north-west of the site and dip in an easterly direction beneath the sandstone at the site and subsequently Mercia Mudstone to the east.
9.61 Groundwater flow within the Magnesian Limestone aquifer is predominantly by fracture flow, although there is some intergranular storage11. Regionally there can be significant variation in transmissivity and yield dependent upon the extent of localised faulting and fracturing.
9.62 Assessments of the aquifer properties of the Magnesian Limestone indicates a significant amount of variation with regards to porosity, hydraulic conductivity and transmissivity. Porosity values for the Cadeby Formation range between 9% and 30% with hydraulic conductivities of between 3.1x10-4 and 0.85m/day. Transmissivity values are even more variable, ranging from 6m2/day to 4,300m2/day. Overall the hydrogeology of the aquifer is controlled by the lithology and the structure, particularly the extent of fracturing with transmissivities typically highest along major fault zones11.
9.63 The Edlington Formation, which separates the two limestone units, is considered to act as a ‘leaky’ aquitard which maintains a slight head difference between the two units11.
9.64 Although groundwater is potentially present within the lower aquifer units; namely the Coal Measures, Millstone Grit and Carboniferous Limestones, the depth to these units (in excess of 300m below ground level) negates the potential for there being any abstractions or receptors within these units at or near to site.
9.65 The Environment Agency groundwater vulnerability mapping indicates that the Nottingham Castle Sandstone aquifer has a ‘High’ groundwater vulnerability owing to the freely draining nature of the overlying soils, high permeability of the sandstones and relatively shallow depth to groundwater.
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Groundwater Levels and Flow
9.66 Groundwater level monitoring data has been provided by the Environment Agency for six groundwater boreholes located within a 5km of the site. The boreholes all monitor the Nottingham Castle Sandstone formation.
9.67 The available monitoring data is summarised in Table 9-7, below, and the groundwater borehole locations near to site are shown on Drawing TL9/1.
Table 9-7 Summary of EA Groundwater Elevation Monitoring Data
Borehole Monitoring Period Count Groundwater Levels (mAOD) Range Identification Min Mean Max (m)
1861GW Apr 92 – Sep 15 285 4.96 5.67 6.42 1.46 8056GW Jul 99 – Aug 15 175 6.72 7.47 7.97 1.25 1725GW Nov 69 – Sep 15 1120 7.72 8.45 9.18 1.46 1728GW Aug 74 – Sep 15 795 8.59 11.43 12.37 3.77 8057GW Jul 99 – Sep 15 197 5.58 6.49 7.49 1.91 1722GW Dec 69 – Jul 13 1040 24.65 26.46 28.53 3.88
9.68 The monitoring data shows that groundwater surface within the Nottingham Castle Sandstone Formation has a typical seasonal variation of between 0.5m and 1m.
9.69 The data indicates that the unsaturated thickness of the sandstones on its western edge (1722GW) is up to 27m in thickness and progressively decreases to the east. Water levels near to the eastern edge of the outcrop (8056 and 8057) are typically between 1m and 4m below ground level.
9.70 The groundwater elevation data indicates that to the east of the site there is hydraulic connection between groundwater and surface water, particularly along the length of the River Idle and its tributaries. In the west of the outcrop, hydraulic connection between groundwater and surface water will be less pronounced where groundwater levels are between 5.5m (1861GW) and 26m (1722GW) below ground level.
9.71 Two Environment Agency groundwater boreholes are located c. 2km east of the proposed exploratory well; these record mean groundwater elevations of 11.43mAOD (c. 10m below ground level) in borehole 1728GW and 8.45mAOD in borehole 1725GW (c. 2m below ground level).
9.72 Based on the available information, regional groundwater flow appears to be in a north easterly direction, this is in keeping with the groundwater contours presented on the BGS hydrogeological map of north-east Midlands, 1981 and follows the regional dip in the strata. A copy of the BGS hydrogeological map is presented as Drawing TL9/6, and shows the groundwater surface in the Nottingham Castle Sandstone at site of c. 13mAOD, which is consistent with the groundwater elevations reported by the Environment Agency discussed above.
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9.73 Therefore, groundwater in the sandstone is expected to be at an elevation of about 13mAOD beneath the site (e.g. c. 15m below ground level).
9.74 There is potential to the north-east and east of the site for groundwater in the Nottingham Castle Sandstone to be locally in hydraulic continuity with more recent superficial deposits and to provide baseflow to watercourses.
9.75 There are fishing lakes at Torworth Grange which are located 1km to the north-east of the proposed exploratory well and information in a current planning application relating to the fishing lakes suggests that the lakes are in hydraulic continuity with groundwater. It is likely that the water table referred to in the planning application is the Nottingham Castle Sandstone water table.
9.76 No groundwater level monitoring data is available for the limestone aquifer however prior investigations of the Permian limestones indicates that the strata dip gently eastwards with some minor folding. Groundwater flow is considered to follow the regional dip of the strata e.g. eastward, although levels and direction can be locally affected by the presence of localised faults11.
Groundwater Abstractions and Source Protection Zones
9.77 The Environment Agency has confirmed that there are five licensed groundwater abstractions located within a 2km radius of the application site, with a further 45 abstractions located within 5km. There are a total of 27 groundwater abstractions and 23 surface water abstractions.
9.78 Most of the groundwater abstractions are for agricultural purposes, with several associated with gravel extraction activities and two classified as potable water supplies. The locations of abstractions near to the application site are shown on Drawing TL9/1. Details of all abstractions within 5km of the application site are included as Appendix 9/2.
9.79 It is understood that all of the groundwater abstractions within a 5km radius of the application site are installed within the sandstones of either the Nottingham Castle Sandstone or Lenton Sandstone.
9.80 The closest groundwater abstraction (ref. A22, Drawing TL9/1) downstream of the application site is located 0.9km north-east. The abstraction is used for spray irrigation. It is noted that the groundwater abstraction at Jubilee Farm is located slightly nearer to the application site (0.8km) but is not located downstream.
9.81 The fishing lakes at Torworth Grange are also located downstream of the application site. The ponds are located 1km from the application site.
9.82 Severn Trent Water has an abstraction licence for two boreholes at Barnby (ref. A31 and A32, Drawing TL9/1). The licence permits the abstraction of groundwater for potable water supply. Review of Drawing TL9/1 confirms that the abstractions boreholes are located more than 2km south-east of the application site and thus the abstractions are not located down groundwater
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gradient from the proposed well. Drawing TL9/1 also confirms that the proposed exploration well is not located in groundwater Source Protection Zone 1 or 2 associated with this licence.
9.83 Bassetlaw District Council has confirmed that there are three private water supplies (PWS) located within a 5km radius of the application site12. All three supplies are groundwater sourced and are understood to be abstracting from the Nottingham Castle Sandstone. Details of the supplies are summarised in Table 9-8. Abstractions near to application site are shown on Drawing TL9/1. The closest abstraction is located 2.3km from the application site.
Table 9-8 Private Water Supplies within a 5km radius of proposed exploration well
Dwg Ref Holder Use Type of Volume (m3) Distance and Abstraction Direction from Site P1 KH Taylor, The Industrial 2x boreholes 15,164m3/yr 5km NW Freezing Station, Sheffield Rd, Blyth P2 Hodsock Priory, Residential (x14 Borehole 14m3/day 3.7km W Hodsock Lane, properties) Hodsock P3 Forest Lodge, Residential (x4 Artesian Well 4m3/day 2.3km WNW Plantation Lane, Blyth properties)
9.84 Table 9-8 confirms none of the recorded private water supplies are located downstream of the proposed exploration well.
9.85 The proposed exploratory well is located within a Zone 3 (Total Catchment) Source Protection Zone (SPZ). This zone applies to the entire Nottingham Castle Sandstone aquifer and reflects both the large number of abstractions within the aquifer and the high vulnerability of the aquifer.
9.86 The Idle and Thorne Catchment Abstraction Management System (CAMS) Licensing Strategy13 indicates that the Nottingham Castle Sandstone is classified as over abstracted and there is no water available for future licensing.
Groundwater Quality
9.87 The Environment Agency has advised that there is no groundwater quality monitoring data is available for the Nottingham Castle Sandstone aquifer or underlying aquifers within the vicinity of the proposed exploratory well. The regional aquifer has however been assessed as part of the 2009 Humber River Basin Management Plan (RBMP)14 and has recently been reassessed
12 Email from James Whalley, Technical Officer at Bassetlaw District Council (02/11/15) Re: private water supplies near Torworth 13 Environment Agency (Feb 2013) Idle and Torne Abstraction Licensing Strategy 14 Environment Agency (Dec 2009) River Basin Management Plan: Humber River Basin District
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within the proposed 2015 RBMP15. The groundwater has been assessed in relation to its chemical and quantitative quality. The assessed values for 2009 and 2015 along with predicted quality for 2021 and 2027 are outlined within Table 9-9.
Table 9-9 Water Framework Directive – Status of Regional Groundwater Variable Idle Tore – Permo-Triassic Sandstone (ID: GB40401G301500) 2009 2015 2021 2027 Classification Classification Predicted Predicted Classification Classification Overall Quantitative Status Poor Poor Poor Poor GWDTE ND Good Good Good Dependent Surface Waters ND Poor Poor Poor Saline Intrusion ND Good Good Good Water Balance ND Poor Poor Poor Overall Chemical Quality Poor Poor Poor Poor Drinking Water Protected Areas ND Poor Poor Poor General Chemical Test ND Poor Poor Poor Chemical GWDTEs Test ND Good Good Good Chemical Dependent Surface ND Good Good Good Waters Chemical Saline Intrusion ND Good Good Good Overall Waterbody Status Poor Poor Poor Poor
Note: GWDTE – Groundwater Dependent Terrestrial Ecosystems
9.88 Both the chemical and quantitative quality of the regional groundwater is classified as ‘poor’ due to the large number of groundwater abstractions impacting on water availability and the overall poor groundwater quality. The latest RBMP indicates that the groundwater is unlikely to meet its target of achieving a ‘good’ status by 2027.
Hydrological Setting and Flood Risk
Regional Hydrology
9.89 The site is located on elevated area above the River Ryton to the west and the River Idle to the east.
9.90 The River Ryton flows in a predominantly northerly direction, approximately 2.5km to the west of the site at its closest point. The river is a tributary of the River Idle and rises from Lindrick Common in Rotherham and discharges to the River Idle just south of Bawtry.
9.91 To the east the ground levels drop to a relatively flat low lying area which is drained via several drains and un-named watercourses which flow in a
15 Environment Agency (Oct 2015) Humber River Basin District: River Basin Management Plan (2015 proposed update)
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predominantly northerly direction, outfalling to the River Idle to the east of Scrooby. The main drain in this area is known as the Ranskill Brook. It is a minor watercourse which rises near to Daneshill Lakes and flows in a predominantly northerly direction to its confluence with the River Idle.
9.92 The site walkover survey confirmed that there are no watercourses or other water features recorded within the site boundary.
Hydrometric Data
9.93 The Environment Agency has provided hydrometric data for the River Ryton. Minimum, mean and maximum daily flows have been provided for the period April 1985 to October 2015. Data has also been provided for the Oldcotes Dyke, a tributary of the River Ryton. The monitoring data is summarised in Table 9-10.
Table 9-10 Environment Agency River Flow Data
Watercourse Flow (m3/sec) Minimum Mean Maximum River Ryton 0.07 1.57 36.5 (1984 – 2015) Oldcotes Dyke 0.043 0.697 66.1 (1970 – 2015)
9.94 The Centre for Ecology and Hydrology National River Flow Archive (NRFA)16 confirms that the River Ryton at Blyth (28091) has a mean flow of 1.575m3/sec with a baseflow index of 0.73 indicating a significant contribution of groundwater to baseflow of the river.
Surface Water Quality
9.95 The Environment Agency has provided surface water quality monitoring data for the River Ryton and two of its tributaries (Owlands Wood Dyke and Oldcotes Dyke) and for the Ranskill Brook, a tributary of the River Idle.
9.96 Key determinands are summarised in Table 9-11.
9.97 Review of Table 9-11 indicates that the surface water quality of the watercourses is typically good, although it is noted that elevated concentrations of some determinands including chloride, ammonia and nitrite, have occasionally been recorded within the River Ryton.
Water Framework Directive Classification
9.98 Regional RBMP have been developed by the Environment Agency to assess the current and future state of all waterbodies including rivers, estuaries,
16 Centre for Ecology and Hydrology National River Flow Archive (Accessed 19/11/15) http://nrfa.ceh.ac.uk/data/station/meanflow/28091
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lakes, coastal waters and groundwaters in relation to the EU Water Framework Directive17.
9.99 The proposed development falls within the Humber River Basin District. The original Humber RBMP was released in 200918 and provided an assessment of the ecological quality of all major surface water bodies as well as chemical and quantitative quality of groundwaters. Predictions for the likely quality in 2015 were also provided along with proposals for ensuring all waterbodies achieve a good ecological status (GES) or good ecological potential (GEP). The assessment was updated when the second Humber RBMP was published in October 201519.
9.100 The key waterbodies assessed by the Humber RBMP within the catchment of the proposed exploratory well are: Surface Water: River Ryton (GB104028058101) Surface Water: Ranskill Brook (GB104028058220) Groundwater: Idle Tor Permo-Triassic Sandstone
9.101 There are no assessed lakes, estuarine waters or coastal waters within a 2km radius of the site.
17 European Union (22.12.2000) Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000, establishing a framework for community action in the field of water policy 18 Environment Agency (Dec 2009) River Basin Management Plan: Humber River Basin District 19 Environment Agency (Oct 2015) Humber River Basin District: River Basin Management Plan (2015 proposed update)
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Table 9-11 Environment Agency Surface Water Quality Monitoring Data Monitoring Alkalinity Ammonia Chloride Electrical Oxidised Nitrate Nitrite Dissolved Orthophosphate pH Suspended Location (mg/l) (mg/l) (mg/l) Conductivity Nitrogen (mg/l) (mg/l) Oxygen (sat (mg/l) Solids (mg/l) (WFD Ref) (µS/cm) (mg/l) %)
Count 318 525 455 34 359 157 205 263 177 526 485 Min 82.4 <0.01 50.7 661 4.99 5.7 <0.1 64 0.05 6.7 <2
Mean 207.59 0.30 236.98 1021.32 13.57 12.66 0.11 96.40 1.50 7.95 27.43
River Ryton River Max 382 3 1980 1455 22.9 19.2 0.7 183 5.89 9.1 804 GB104028058101
Count 30 30 30 30 30 30 30 30 30
Min 159 <0.03 595 6.8 6.75 0.0238 70 0.106 7.5
Mean 202.2 0.18 928.30 14.34 14.28 0.08 90.1 0.32 8.05
OldcotesDyke Max 244 1.67 1168 19.6 19.5 0.167 103 0.684 8.6 GB104028058200
Count 213 286 266 29 247 105 105 181 175 309 140
Min 105 <0.03 25.3 730 4.35 4.3 0.004 60 0.111 6.2 <2 Wood
Dyke Mean 217.69 0.30 81.19 942.24 15.31 14.44 0.11 85.04 1.05 7.84 30.31
Owlands Max 366 2.3 168 1262 23.4 23.34 1 115 8.7 8.7 656 GB104028058190
Count 199 354 196 62 343 232 243 243 302 359 268
Min 102 <0.03 33 637 5.15 7.843 0.0143 50 <0.01 7.07 <2
Mean 152.52 0.30 60.31 768.40 14.66 14.21 0.06 102.96 0.12 8.00 9.18
Ranshill Brook Max 197 8.09 95.6 867 25.6 19.521 0.307 184 1.07 9.3 57 GB104028058220
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River Ryton Catchment
9.102 The historic, current and predicted future WFD classification of the River Ryton is outlined in Table 9-12. The data indicates that the overall waterbody status is currently ‘Moderate’ due to moderate levels of macrophytes and phytobenthos and elevated phosphate levels within the watercourse. The overall hydromorphology of the watercourse has improved since 2009 and now supports good conditions.
Table 9-12 Water Framework Directive Status of the River Ryton Variable River Ryton (ID: GB104028058101) 2009 2015 2021 2027 Classification Classification Predicted Predicted Classification Classification Overall Ecological Status Moderate Moderate Moderate Moderate Biological Elements Good Moderate Moderate Moderate o Fish Good High High High o Macro - Invertebrates Good Good Good Good o Macrophtyes & Phytobenthos NA Moderate Moderate Moderate Hydromorphological Elements Hot High Supports Good Supports Good Supports Good o Hydrological Regime Not High Supports Good Supports Good Supports Good o Morphology Good NA NA NA Physiochemical elements Moderate Moderate Moderate Moderate o Ammonia Good High High High o DO High High High High o pH High High High High o Phosphate Poor Poor Poor Poor Overall Chemical Quality Good Good Good Good Specific Pollutants Good High High High o Ammonia Good NA NA NA o Arsenic High NA NA NA o Copper High High High High o Zinc High High High High Priority Substances NA Good Good Good o Lead & its compounds NA Good Good Good o Nickel & its compounds NA Good Good Good Priority Hazardous Substances NA Good Good Good o Benzo(b)and (k) fluoranthene NA Good Good Good o Bezo(a)pyrene NA Good Good Good o Cadmium NA Good Good Good o Di(2-ethylexyl)phthalate NA Good Good Good o Mercury NA Good Good Good o Nonylphenol NA Good Good Good o BDPE NA Good Good Good Overall Waterbody Status Moderate Moderate Moderate Moderate
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9.103 The Environment Agency has set a target of maintaining a ‘Moderate’ ecological status by 2027. Ranskill Brook Catchment
9.104 The historic, current and predicted future classification of the Ranskill Brook is outlined in
9.105 Table 9-13. The data indicates that the overall status of the watercourse is currently assessed as ‘Good’, improving from ‘Moderate’ in 2009.
Table 9-13 Water Framework Directive Status of the Ranskill Brook Variable Liverton Brook (ID: GB104028058220) 2009 2015 2021 2027 Classification Classification Predicted Predicted Classification Classification Overall Ecological Status Moderate Good Good Good Biological Elements Moderate Good Good Good o Diatoms Moderate NA NA NA o Invertebrates Good Good Good Good o Macrophytes and NA Good Good Good Phytobenthos Hydromorphological Elements Not High Supports Good Supports Good Supports Good o Hydrological Regime Moderate Does Not Does Not Does Not Support Good Support Good Support Good Physiochemical elements Good Good Good Good o Ammonia High High High High o DO Good Good Good Good o pH High High High High o Phosphate Good Good Good Good o Temperature NA High High High Overall Chemical Status Does not require assessment Overall Waterbody Status Moderate Good Good Good
Surface Water Abstractions and Discharges
9.106 The Environment Agency has provided details of licensed surface water abstractions and consented discharges within a 5km radius of the proposed exploratory well.
9.107 There are a total of 23 licensed surface water abstractions within a 5km radius of the application site. Abstractions are mostly from the River Ryton and River Idle and are primarily for agricultural purposes. Surface water abstractions near to the application site are shown on Drawing TL9/1. Details of the abstractions are shown in Appendix 9/2.
9.108 There are a total of 35 consented discharges within a 5km radius of the application site, the locations of those near to application site are shown on Drawing TL9/1.
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Flood Risk Assessment
9.109 Environment Agency Flood mapping is included on Drawing TL9/1 and indicates that the proposed development is located entirely within Flood Zone 1 (Low Probability).
9.110 Review of Environment Agency mapping indicates that the application site is also classified as ’very low’ risk of flooding from surface water and outside any potential flood extent associated with reservoir flooding.
9.111 Given the site setting, on an elevated area of land with topography sloping away to the north, west, south and east from the application site the groundwater flood risk is also considered to be ‘low’. Available groundwater level monitoring from the wider sandstone aquifer indicates that groundwater is located more than 10m below site and there is limited seasonal variation of c.0.5m to 1m per year and therefore the likelihood of a significant rise in groundwater levels resulting in flooding of the application site is low.
9.112 A summary of the potential sources of flooding and a review of the potential risk posed by each source at the application site is presented in Table 9-14, below.
Table 9-14 Potential Risks Posed by Flooding Sources
Potential Source Potential Flood Risk Reason for Decision to Application Site Fluvial Flooding No The site is located entirely within Flood Zone 1, low probability Tidal Flooding No The site is remote from the coast Flood Defence Breach No There are no flood defences present (Failure) within the vicinity of the site Flooding from rising / No Little groundwater variation is recorded by high groundwater long term groundwater monitoring boreholes Overland flow No The site is located on an elevated position flooding with ground levels sloping away to the north, west and south Flooding from No No other drainage systems are present up artificial drainage gradient of the application site. systems
9.113 Table 9-14 confirms that the application site is not at risk of flooding, and thus flood risk should not be an impediment to development.
9.114 Measures have been proposed to collect and manage rainfall runoff shed from site during and following development of the application site in the Sections that follow.
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Water Dependent Ecological Sites
9.115 Review of the Natural England’s Nature on the Map website20 show there are two designated sites located within 3km radius of the proposed exploratory well. Details are given below. Mattersey Hill Marsh SSSI
Is an area of mixed marsh developed on the site of former gravel workings. The area has permanently wet soils and has been designated for the flora, fauna and woodland which has developed within the varied water depths of the marsh21. It is located 2.7km north-east of the site.
The marsh is potentially down gradient of the site and may receive a contribution of groundwater from the Nottingham Castle Sandstone in addition to the superficial deposits that lie adjacent to the marsh locally.
Daneshill Local Nature Reserve
Is also a former gravel extraction area which has been restored as a wildlife reserve consisting of open water habitat surrounded by willow woodland22. It is located 1.6km north-east of the site.
Like Mattersey Hill Marsh, the Daneshill nature reserve is down gradient of the site and may receive a contribution of groundwater from the Nottingham Castle Sandstone in addition to the superficial deposits that lie adjacent to the reserve locally.
Summary of Potential Receptors
9.116 The baseline conditions described above and the site walkover survey have been used to develop a conceptual model for the proposed development. The receptors identified in Table 9-15 have been assessed and show a potential to be impacted by the proposed development.
Table 9-15 Potential Receptors and their Sensitivity
Receptor Sensitivity Characteristics Nottingham Castle and High Principal Aquifer Lenton Sandstones Groundwater surface shown to be close (<20m) to the ground surface and groundwater shown to support water supplies and provide baseflow to surface water features Magnesian Limestone High Principal Aquifer Considered to be in hydraulic continuity with overlying Nottingham Castle and Lenton Sandstones
20Natural England (Accessed 24/11/15) http://www.natureonthemap.naturalengland.org.uk/MagicMap.aspx 21 http://www.sssi.naturalengland.org.uk/citation/citation_photo/1000999.pdf 22 Nottinghamshire Wildlife Trust Website (Accessed 24/11/15) http://www.nottinghamshirewildlife.org/nature- reserves/daneshill-gravel-pits
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Receptor Sensitivity Characteristics Surface Watercourses High Larger surface watercourses shown to be in hydraulic continuity with Nottingham Castle sandstone. Surface water provides recreational benefit (fisheries and potentially water sports). Ground and Surface Water High Many of the surface and groundwater abstractions Abstractions & Users (licensed and unlicensed) are used for irrigation (e.g. indirectly for human consumption) or used for potable water supplies. Surface watercourses are also used for recreational purposes. There are fishing ponds at Torworth Grange. Mattersey Hill Marsh SSSI High Potentially in hydraulic continuity with groundwater that the proposed exploratory well will be drilled through. Designated as SSSI and thus considered of greater importance than Daneshill Local Nature Reserve, Daneshill Local Nature Medium Potentially in hydraulic continuity with groundwater that Reserve the proposed exploratory well will be drilled through. Of local or regional importance.
9.117 As described in the Sections that follow and subject to adherence to best practice guidance the soils at the application site are not considered to be a receptor that may be impaired as a consequence of development. It is shown that the soils at site can be safeguarded and reused as part of the application site decommissioning. This potential receptor, therefore, is not considered further.
9.118 Similarly, given the proposed development at site and the absence of coal workings beneath the application site, no impacts on the geology beneath the site, or with regard ground instability would occur. This potential receptor, therefore, is not considered further. ASSESSMENT OF EFFECTS
Summary of the Proposed Development
9.119 A detailed description of the proposed development is given in Chapter 3. Details relevant to the assessment of potential effects on geology, hydrogeology and hydrology are presented below.
9.120 It is proposed to drill a single exploration well and three sets of monitoring wells, to sample groundwater and ground gas. The monitoring wells would allow ground gas concentrations, groundwater levels and quality to be recorded upstream and downstream of the exploration well.
9.121 The groundwater and gas monitoring wells would be established prior to the exploration well in order to collect baseline monitoring data. The location of the monitoring wells are shown on Drawing TL3/03A, the locations of which have been agreed with the Environment Agency as part of pre-application discussions.
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9.122 Specifically: The exploratory well would be a multi core well which would be used to recover samples from, and to measure the properties of the geological sequence proven by the borehole, including the Bowland Shale and drainage features.
The wellsite platform would be formed by an impermeable geotextile membrane overlain by inert aggregate hardstanding.
Millstone Grit group geological formations that underlie the site.
Core samples would be taken at multiple intervals whilst drilling.
Hydraulic fracturing would not be performed in the well.
9.123 Depending on the core analyses, electronic logging results and geological modelling, the well would either be plugged (to surface) and abandoned (in accordance with OGUK guidelines and regulatory requirements) and the application site restored back to its current agricultural use or it could continue to be used for temporary baseline seismicity monitoring.
9.124 The well evaluation period could last up to two years and during this stage the well would be suspended and maintained in accordance with industry best practice and all above ground equipment would be removed from the application site apart from the wellhead, site offices and security fencing.
The Establishment Phase
9.125 To establish the wellsite, the following construction works would be undertaken:
Existing soils would be stripped and stored in onsite bunds (the bunds would be seeded and maintained for the life of the development).
Bunds and arisings would be placed away from watercourses and Bunded storage areas for fuels, chemicals, surface water attenuation and site welfare facilities would be installed.
Containerised diesel generators would be used as a source of power.
Groundwater and ground gas monitoring locations and designs as agreed with the Environment Agency would be installed.
The Drilling and Evaluation Phase
9.126 During drilling and evaluation the following works would be undertaken and the following processes completed on site: All materials would be handled in accordance with COSHH guidelines.
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Details of the proposed drilling muds and materials that would be used or stored on site would be as agreed with the Environment Agency.
Containerised diesel generators would be used as a source of power.
Pumps and storage tanks for diesel, water, drilling mud and cuttings would be deployed.
Drilling mud and cuttings would be stored in tanks and would be transported offsite by a permitted haulier for treatment and/or disposal at an appropriately permitted waste management facility.
Surface water runoff would be collected and managed. The surface water system would be designed to contain runoff from at least a 1 in 100 year storm. It is proposed that collected runoff is taken from site by tanker to an appropriately permitted water treatment facility.
Mixing and handling of materials would be undertaken in designated areas away from surface water drains.
Site welfare facilities would be maintained and waste water removed from site.
9.127 At the end of the drilling phase a Pressure Determination Test (PDT) would be undertaken in the exploratory borehole to assess the strength of the target formation(s). The test uses a small quantity of potable water to measure the strength of the rock. No chemicals are used to perform the test. No water flow back occurs as part of the test.
9.128 Should the drilling and evaluation phase suggest that further use of the application site may be viable then a second planning application would be made to Nottinghamshire County Council for continued use and restoration of the site.
The Restoration and Decommissioning Phase
9.129 In the event that the results of the exploration work indicate that further development of the application site is not required or viable, the exploratory well would be plugged and capped in accordance with industry best practice including the OGUK Guidelines for the Abandonment of Wells.
9.130 The groundwater and ground gas monitoring boreholes would be abandoned in accordance with Environment Agency guidelines.
9.131 The remaining surface development would then be removed from the application site, the stockpiled topsoil and subsoils would be replaced and the application site would be restored back to its previous agricultural use.
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Mitigation by Design
9.132 With respect to geology and the water environment the key potential impacts of the proposed development include: The possible pollution of groundwater and surface water from the handling and use of drilling fluids and cuttings, suspended solids and other potential pollutants.
The integrity of the well design and its ability to prevent the escape of drilling fluids, gas and formation fluids directly into groundwater and indirectly to surface water.
9.133 The site design and mitigation incorporated in the site design has been made with reference to current best practice guidelines, including: Well Design and Operation
The Boreholes Sites and Operations Regulations 1995 (SI 1995/2008); The Offshore Installations and Wells (Design and Construction, etc.) Regulations 1996, (SI 1996/2008); OG UK Well Life Cycle Integrity Guidelines, Issue 3, March 2016; UK Onshore Shale Gas Well Guidelines Exploration and Appraisal Phase Issue 3, UKOOG, March 2015; OGUK Guidelines for the Abandonment of Wells, Issue 5, July 2015; Guidelines on Qualification of Materials for the Abandonment of Wells, Issue 2, October 2015; Environment Agency Onshore Oil and Gas Sector Guidance, Consultation Draft, November 2015; and API standards (where applicable).
Pollution Control and Monitoring
The SUDS Manual C753, CIRIA, 2015; and Environmental Good Practice on Site C741, CIRIA, 2015.
The Pollution Prevention Guidelines (PPG) identified below are the principal guidance documents for preventing water pollution and erosion from construction activities:
PPG1 General Guide to the Prevention of Pollution (PPG1, July 2013); PPG2 Above Ground Oil Storage Tanks (PPG2, August 2011); PPG3 Use and Design of Oil Separators in Surface Water Drainage Systems (PPG3, April 2006); PPG4 Treatment and Disposal of Sewage where no Foul Sewer is Available (PPG4, July 2006); PPG6 Working at Construction and Demolition Sites (PPG6, May 2012); PPG7 Safe Operation of Refuelling Facilities (PPG7, July 2011); PPG8 Safe Storage and Disposal of used Oils (PPG8, February 2004); PPG13 Vehicle Washing and Cleaning (PPG13, July 2007); PPG18 Managing Fire Water and Major Spillages (no date given);
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PPG21 Pollution Incident Response Planning (PPG 21, March 2009); PPG22 Incident Response – Dealing with Spills (PPG22, April 2011); and PPG26 Drums & intermediate bulk containers (PPG 26, May 2011).
9.134 In addition IGas has undertaken a review of potential drilling hazards that might be experienced, as follows: borehole instability; losses; hard formation; formation gas; hydrogen sulphide and carbon dioxide; formation temperature; and formation pressure.
9.135 With reference to the potential drilling hazards and industry guidance the Sections that follow summarise the mitigation measures included in the site design.
Management and Operational Procedures
9.136 The management and operational procedures that would be used to prevent or reduce impacts are as follows:
IGas has an Integrated Management System Manual which sets out the standards and procedures to which IGas is committed to uphold at all sites, see Appendix 3-1.
IGas will prepare a site monitoring plan which will state monitoring locations, analytical suite, sampling method and frequencies, set triggers and warnings for concentrations all to be agreed and approved by the Environment Agency and Nottinghamshire County Council
IGas would undertake all statutory reporting obligations for the Proposed Development, including data collection and reporting to DECC, Environment Agency, HSE and the British Geological Survey (BGS).
A Construction and Environmental Management Plan (CEMP) that considers accidental pollution would be prepared and agreed with key statutory stakeholders prior to any construction at site.
9.137 Diesel tanks on site would have secondary containment which in addition to the sealed wellsite would ensure that any spillages would be contained within the wellsite. Any refuelling would also be undertaken within the sealed wellsite. Spill kits would be available and staff would be trained to use them. An emergency spillage plan would form part of the proposed CEMP.
9.138 Tool box talks would form part of the site operations and would be used to ensure that all staff present on site were fully aware of the potential impacts
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associated with proposed operations and procedures to be followed, should an accidental pollution event occur.
9.139 The use of and adherence to management plans and operational procedures would reduce the potential impact from operations and accidents on potential receptors.
Baseline Monitoring
9.140 In consultation with Nottinghamshire County Council and the Environment Agency, IGas would establish and implement a baseline monitoring programme in advance of works being undertaken at site and the exploratory well being drilled.
9.141 The monitoring programme would allow groundwater quality, groundwater levels and ground gas to be recorded upstream and down of the site. The specific details of the monitoring programme could be secured by an appropriately worded pre-development planning condition.
9.142 In accordance with best practice, the monitoring boreholes would be designed and completed at a diameter that would allow the installation of groundwater sampling equipment and allow representative ground gas data to be collected. The frequency of monitoring, and the range of determinands monitored would be agreed with Nottinghamshire County Council and the Environment Agency.
9.143 The baseline monitoring would continue into the construction, operation and decommissioning phases of the site.
9.144 The monitoring programme will allow early identification of any potential impacts on groundwater (and indirectly to surface water) from the proposed site, so that in the unlikely event variation from baseline conditions is recorded, mitigation can be instigated which would reduce the potential impact on potential receptors. In the very unlikely event a variation from baseline conditions is recorded mitigation measures would be agreed with Nottinghamshire County Council and the Environment Agency.
Well Pad Design
9.145 The well pad would be lined by an impermeable liner to provide a barrier between surface activities and groundwater.
9.146 The well pad would be positively drained. Runoff (and any pollutants in the runoff) would be collected in a lined tank prior to collection and disposal offsite at any appropriable permitted facility.
9.147 Bunding would be provided around the well pad to contain the failure of the largest fluid containers that would be used on site.
9.148 Materials required or generated by the proposed development that might pose a risk to the water environment (e.g. drilling fluid, cuttings, fuel, waste welfare water) would be stored in impermeable containers sized in
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accordance with best practice guidance so as to minimise the potential impact on receptors. These materials would be routinely removed from the application site and disposed of at appropriately licensed facilities.
Drilling and Well Integrity
9.149 Drilling of exploratory wells to this depth and through the same/similar geological sequence has been undertaken on many occasions in the UK (onshore and offshore). As a result, measures required to maintain the well design and integrity are very well understood.
9.150 Notwithstanding this, the risk of potentially polluting materials to groundwater (and indirectly to surface water) would be minimised to a low as reasonably practicable (ALARP) by good practice well design and construction, best available techniques (BAT) and working to the following best practice guidance and regulations: The Borehole Sites and Operations Regulations (1995) The Offshore Installations and Wells (Design and Construction, etc.) Regulations (1996) Oil and Gas UK Well Life Cycle Integrity Guidelines (Issue 3, March 2016) UKOOG UK Onshore shale gas well Guidelines (Issue 3, 2015) Guidelines for the Abandonment of Wells (Issue 5, July 2015) Guidelines on Qualification of Materials for the Abandonment of Wells, Issue 2, October 2015; and API standards (where applicable).
9.151 In respect to pollution control, the design of the well would engage best available techniques (BAT) and would provide sufficient barriers (steel and cement) between the well and groundwater, to reduce any such risk to as low as reasonably practicable (ALARP). The well design and drilling programme would be submitted to an independent well examiner for review. That examiner must be ‘independent’ and ‘competent’ as defined by Oil & Gas UK industry guidance. Any concerns that the examiner may have would be discussed, remedied and agreed between the operator and the well examiner. Following well examination the design and programme would be submitted to the Health & Safety Executive (HSE) under a 21-day notification regulatory requirement. The Health & Safety Executive (HSE) would review and comment if they have any concerns. Well consent is acquired from the Oil & Gas Authority (OGA). Following this, well operations can commence. The above is in line with the Borehole Sites and Operations Regulations 1995 and the Offshore Installations and Wells (Design and Construction, etc.) Regulations 1996.
9.152 Steel casing would be used to construct the well. This is cemented in the well in stages to protect groundwater and maintain well integrity.
9.153 Cement would be would be pumped in the form of a slurry inside the well casing. This then rises up through the annular space between the outer face of the casing and the side of the exploratory well. The cement is then set.
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All casing strings would be pressure tested during installation to confirm full integrity and the results would be recorded and maintained.
9.154 A water based drilling fluid would be used when the well is being drilled through the Nottingham Castle Sandstone, Lenton Sandstone and the Magnesian Limestone. No hazardous substances would be used when drilling through the Principal Aquifers beneath the application site.
9.155 After adequate isolation by casing and cement grout (which would be agreed with the Environment Agency) a low toxicity oil based drilling mud would be used to drill through the deposits below the Magnesian Limestone. The composition of the mud would also be agreed with the Environment Agency prior to use.
9.156 In accordance with common industry practice, best available technique (BAT) and to reduce risk of unplanned escape of well fluids to as low as reasonably practicable (ALARP) a suitably pressure rated wellhead would be installed on the well within the well cellar. The pressure rated wellhead would be installed on the surface, intermediate and production casing strings during well construction. The wellhead will remain on the well for its full lifecycle duration. During drilling operations a blow-out preventer would be installed for drilling sections below the Sherwood sandstone to provide secondary well control. Primary well control is by means of hydrostatic mud column.
9.157 The likelihood of lost circulation and required safeguards would be considered, risk assessed and mitigated to ALARP during the well design process. The well design and programme would be reviewed by an independent well examiner and submitted to the Health & Safety Executive. Details of any lost circulation materials that could be utilised during construction would be included in the environmental permitting process and agreed with the EA
9.158 The well design would also consider full lifecycle procedures for monitoring the integrity of the exploratory well during the evaluation period, and required safeguards, to the satisfaction of the HSE.
9.159 Well abandonment or suspension would be undertaken in accordance with best practice and regulatory guidance.
9.160 The measures above would prevent or minimise risk to ALARP of the potential impacts of drilling fluids, gas or formation fluids on receptors. Potential Effects
9.161 This section presents the findings of the assessment for the 3 proposed phases of development at site: establishment, drilling and evaluation, and restoration and decommissioning.
9.162 The assessment uses the methodology presented at the start of this Chapter and the receptors identified following the site walkover and review of the site setting.
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Establishment Phase
9.163 There is limited potential for spillages of oils / fuels during construction of the well pad and also for the generation of suspended solids from areas of earth movement. The likelihood of pollution occurring (with reference to the embedded mitigation) is assessed as very low.
9.164 The sensitivity of groundwater in the Nottingham Castle Sandstone, superficial geological deposits and watercourses is assessed as high.
9.165 There is potential for vertical migration of pollution through the soils at the application site to the sandstone and as a consequence of the hydraulic continuity of groundwater with surface water for this pollution to impair both groundwater (in the sandstone and indirectly in the superficial deposits) and surface water to the north-east of the application site.
9.166 As a consequence of the embedded mitigation the magnitude of impact on groundwater locally beneath the application site in the Nottingham Castle Sandstone is assessed as minor, and the resultant significance of effect on groundwater quality, groundwater abstractions and the fishing ponds at Torworth Grange is assessed as minor.
9.167 Given works would be limited to the ground surface, negligible impact on groundwater in the deeper Lenton Sandstone or the Magnesian Limestone would be expected. The resultant significance of effect on water quality in these units is therefore assessed as negligible.
9.168 The sensitivity of surface water is also considered high but as there are no surface watercourses near to the application site and because much attenuation and dilution in groundwater would occur before any pollution would enter surface water, the resultant significance of effect on surface water is assessed as negligible.
9.169 The sensitivity of Mattersey Hill Marsh Hill SSSI is considered high and Daneshill Nature Reserve medium. The potential indirect impact as a consequence of groundwater from beneath the application site passing to the SSSI and Nature Reserve is assessed as negligible given their distance from the application site and the very low likelihood of a pollution event occurring. The resultant significance of effect is as assessed as negligible at both Mattersey Hill Marsh Hill and at Daneshill Local Nature Reserve.
9.170 Similarly, given the embedded mitigation and the absence of adjacent surface watercourses, direct surface water runoff in response to rainfall from the application site would result in a negligible impact on surface water quality or flood risk. The resultant significance of impact on surface water quality and flood risk is assessed as negligible.
Drilling and Evaluation Phase
9.171 Without controls there is potential for spillages on the well pad during this phase of development due to the activities that would be undertaken on the well pad which could impair water quality in the Nottingham Castle
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Sandstone and indirectly surface water and groundwater in the superficial deposits to the north-east of the site.
9.172 In addition, without appropriate design, drilling fluids, gas and formation fluids could escape into the Nottingham Castle Sandstone, Lenton Sandstone and Magnesian Limestone and as a result of drilling the well.
9.173 The sensitivity of groundwater within the sandstones and limestone, and within the superficial deposits and surface watercourses to the north-east of the application site is assessed as high. However, the proposed management measures, embedded mitigation and proposed environmental monitoring will prevent or reduce the potential impact on water quality. Therefore, the potential impact on groundwater quality locally is assessed as minor and thus of minor significance.
9.174 Groundwater abstractions are also considered to be of high sensitivity and for the same reasons above, potential impacts on water quality and quantity is assessed as minor. Potential effects on nearby groundwater abstractions and the fishing ponds at Torworth Grange are assessed as of minor significance.
9.175 There are no surface water courses near to the application site. There would be no direct discharge of pollution to surface water, and significant attenuation and dilution of any pollution event would occur before a discharge (via ground surface or via groundwater) is made to a surface watercourse. The potential impact on surface waters and surface water abstractions is therefore considered negligible and assessed to have a negligible significance of effect.
9.176 The sensitivity of Mattersey Hill Marsh Hill SSSI is considered high and Daneshill Nature Reserve medium. Given the distance from the application site and the natural dilution and attenuation of any pollution that could occur, the potential indirect impact as a consequence of groundwater from beneath the application site passing to the SSSI and Nature Reserve is assessed as negligible, and the resultant significance of effect is assessed as negligible at both Mattersey Hill Marsh Hill and at Daneshill Local Nature Reserve.
9.177 Given the proposed measures to collect and control surface water runoff from the application site and the site location the development would not increase flood risk offsite and thus there would be negligible increase in flood risk and a resultant negligible significance of effect.
Restoration and Decommissioning Phase
9.178 The application site restoration and decommissioning stage, like the establishment phase, has the potential to introduce pollution to groundwater and indirectly to surface water. There is also potential for new groundwater pathways for pollution to be introduced.
9.179 As detailed above, groundwater, surface water and water abstractions are considered to have a high sensitivity.
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9.180 Given the embedded mitigation, adherence to best practice and temporary nature of this phase the impact on groundwater quality and nearby groundwater abstractions and the Torworth Grange fishing ponds is assessed as minor. The resultant significance of effect is assessed as a minor.
9.181 As for the establishment phase the impact on surface water quality and on surface water abstractions is assessed as negligible. The resultant significance of effect is assessed as negligible.
9.182 The sensitivity of Mattersey Hill Marsh Hill SSSI is considered high and Daneshill Nature Reserve medium. As a consequence of the distance from the application site, and the dilution and attenuation of any pollution that would occur, the potential indirect impact as a consequence of groundwater from beneath the application site passing to the SSSI and Nature Reserve is assessed as negligible, and the resultant significance of effect is as assessed as negligible at both Mattersey Hill Marsh Hill and at Daneshill Local Nature Reserve.
9.183 The restoration phase would return the application site to pre-development conditions and thus replicate existing rainfall runoff rates. Therefore there would be a negligible increase in flood risk and a resultant negligible significance of effect on flood risk.
PROPOSED MITIGATION
9.184 As there are no predicted significant effects identified in accordance with the EIA Regulations, no additional mitigation during the establishment, drilling and evaluation, or decommissioning and restoration is required. RESIDUAL EFFECTS
9.185 No significant residual effects on geology of the water environment (hydrogeology, hydrology and flood risk) are predicted during the establishment, drilling and evaluation, or decommissioning and restoration phases of the proposed development. An assessment of residual effects is therefore not required. CUMULATIVE EFFECTS
9.186 Given the nature of the proposed development and the absence of identified significant effects it is considered unlikely that the proposed development would give rise to significant cumulative effects and these are therefore not considered further. CONCLUSIONS
9.187 A summary of the potential effects is provided in Table 9-16.
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Table 9-16 Potential Receptors and their Sensitivity
Phase Potential Source Receptor Sensitivity of Magnitude Effect of Impact Receptor of Impact* Establishment Pollution from Nottingham High Minor Minor spillages and from Castle (Not Significant) suspended solids Sandstone generated by Lenton High Negligible Negligible movement of soils Sandstone (Not Significant) Magnesian High Negligible Negligible Limestone (Not Significant) Surface High Negligible Negligible watercourse (Not Significant) Mattersey Hill High Negligible Negligible Marsh SSSI (Not Significant) Daneshill LNR Medium Negligible Negligible (Not Significant) Increase in Rate of Flood Risk Minor Negligible Negligible Runoff (Not Significant) Nottingham High Minor Minor Drilling & Pollution from (a) Castle (Not Significant) Evaluation spillages and Sandstone handling site Lenton High Minor Minor materials and/or Sandstone (Not Significant) (b) escape of Magnesian High Minor Minor drilling fluids / Limestone (Not Significant) formation gas from Surface High Negligible Negligible the well watercourse (Not Significant) Mattersey Hill High Negligible Negligible Marsh SSSI (Not Significant) Daneshill LNR Medium Negligible Negligible (Not Significant) Increase in Rate of Flood Risk Minor Negligible Negligible Runoff (Not Significant) Pollution from (a) Nottingham High Minor Minor Decommissioning spillages and Castle (Not Significant) & Restoration handling site Sandstone materials and/or (b) escape of Lenton High Minor Minor drilling fluids / Sandstone (Not Significant) formation gas from Magnesian High Minor Minor the well and/or (c) Limestone (Not Significant) suspended solids from the re- Surface High Negligible Negligible instatement of soils watercourse (Not Significant) Mattersey Hill High Negligible Negligible Marsh SSSI (Not Significant) Daneshill LNR Medium Negligible Negligible (Not Significant) Increase in Rate of Flood Risk Minor Negligible Negligible Runoff (Not Significant)
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*Incorporating embedded environmental, design and management measures
9.188 This Chapter has assessed the likely significance of effects of the proposed development during establishment, drilling and evaluation, and decommissioning and restoration on geology and the water environment (hydrology and hydrogeology).
9.189 The assessment, which has included a detailed site walkover survey and a detailed review of the existing site conditions, has concluded that the proposed development has no significant effects following the adoption of good practice measures and regulatory best practice. No cumulative effects with any other developments have been identified.
9.190 The assessment has shown that the proposed development would not impair the wholesomeness of groundwater or surface water, effect water abstractions, recreational users or ecological habitats dependent on ground or surface water, nor effect designated ecological sites near to site.
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