Land south of the A513, Orgreave, Alrewas 12 HYDROGEOLOGY AND FLOOD RISK The following Technical Appendices referred to in this chapter can be found at Appendix 5 to this document. Appendices: Appendix 5.1 – Site Visit Photographs Appendix 5.2 – Alrewas Quarry Factual Report – Ground investigation by Geotechnics Appendix 5.3 – Alrewas Quarry Factual Report – Geophysics Survey by SUMO Appendix 5.4 – Surface Water Quality Results Appendix 5.5 – Groundwater Quality Results Appendix 5.6 – Orgreave Farm Dewatering Assessment Appendix 5.7 – Orgreave Farm Drainage Strategy Appendix 5.8 – Drawing - Site Survey: Hydro Detail and BHs by CEMEX CEMEX UK Operations February 2020 1 Land south of the A513, Orgreave, Alrewas 12.1 Introduction 12.1.1 This chapter of the Environmental Statement (ES) has been prepared by Stantec UK Ltd (Stantec) and considers the potential hydrogeological and hydrological impacts associated with the proposal. It also includes an assessment of flood risk both to and from the Application Site. 12.1.2 Where relevant, mitigation measures are proposed to minimise the impacts of the proposed development during both the preparation, operational and restoration phases of the scheme. Any anticipated residual effects of the proposals are then stated. 12.1.3 A full description of the Proposal is outlined in Chapter 2 of this ES. This section provides further details on aspects relevant to the water environment. 12.1.4 It is proposed to dewater in order to work part of the quarry voids dry. The final 4 m of each void will be worked wet and dewatering would be undertaken to this level to maintain these levels. Water derived from the dewatering process would be used on-site under the terms of a full abstraction licence for wheel washing, dust suppression and mineral processing. Water abstracted from the quarry void that is not consumed would be discharged to the Pyford Brook under the conditions of a dewatering transfer licence and a discharge permit. Suspended solids would be allowed to settle out of suspension in settlement lagoons prior to discharge off-site. 12.1.5 Drainage from the Application Site would be conveyed to waterbodies and quarry voids at the Application Site prior to discharge off-site to the Pyford Brook. Once restored, drainage from the Application Site would be captured by the restored lake in the quarry void. Scope 12.1.6 This chapter covers the requirements of a Hydrogeological Impact Assessment (HIA) and Flood Risk Assessment (FRA). The scope of work undertaken for this ES chapter includes the following: Review of the baseline hydrogeology and hydrology for the Application Site and surrounding area; CEMEX UK Operations February 2020 2 Land south of the A513, Orgreave, Alrewas identification of receptors and assessment of likely significant effects from the Proposal based on a dewatering assessment (Appendix 5.6); recommendations for appropriate monitoring and mitigation measures; and a drainage strategy to manage and mitigate flood risks posed to and from the Application Site, appended in Appendix 5.7. 12.1.7 The chapter includes the following tables and figures: List of Figures Figure 12.1 ........................................................................ Application Site and study area Figure 12.2 ................................................................................... Surrounding topography Figure 12.3 .............................................................................................. Bedrock geology Figure 12.4 ........................................................................................... Superficial geology Figure 12.5 .............................. Contact between sand and gravel and Gunthorpe Member Figure 12.6 ............................................................................................. Mineral thickness Figure 12.7 ................................................ Neighbouring historical and authorised landfills Figure 12.8 ..................................................................................... Surface water features Figure 12.9 .................................................................... Groundwater monitoring locations Figure 12.10 ..................................................................... Groundwater level hydrographs Figure 12.11 ..................................................... Local hydrogeology at the Application Site Figure 12.12 ................................................................................... Fluvial flood risk zones Figure 12.13 ....................................................................... Surface water flood risk zones Figure 12.14 .................................................................................Reservoir flood risk map Figure 12.15 ..................................................... Surface water quality monitoring locations Figure 12.16 ..........................................Neighbouring licenced surface water abstractions Figure 12.17 ......................................................... Neighbouring groundwater abstractions Figure 12.18 ....................................................................... Neighbouring designated sites Figure 12.19 ......................................................... Conceptual hydrogeology cross section List of Tables Table 12.1 ........................................................ Methodology for assessing receptor sensitivity Table 12.2 ................................................................................... Assessing magnitude of impact Table 12.3 ...................................................... Determination of level of effect and significance CEMEX UK Operations February 2020 3 Land south of the A513, Orgreave, Alrewas Table 12.4 .................................................... Summary of local geology at the Application Site Table 12.5 .................. Historical and authorised landfills within 4 km of the Application Site Table 12.6 ..... Mean monthly rainfall totals for the EA rain gauge at Lichfield (2001 - 2018) Table 12.7 ...................................... Surface watercourses within 4 km of the Application Site Table 12.8 ...................Summary of surface waterbodies within 4 km of the Application Site Table 12.9 ................................... Flow statistics for the River Trent at Yoxhall (1959 – 2018) Table 12.10 ............... Groundwater monitoring locations at and around the Application Site Table 12.11 ..................................................................... Groundwater level summary statistics Table 12.12 . Hydraulic conductivity estimates from particle size distributions presented by (Geotechnics, 2017) Table 12.13 .............................................. Flood risk vulnerability and flood zone compatibility Table 12.14 ...................................... Licenced abstractions from surface water point sources Table 12.15 ............................................... Licenced abstractions from surface water reaches Table 12.16 .................................... Licenced groundwater abstractions within the study area Table 12.17 .............................................. Private abstractions in Lichfield District within 4 km Table 12.18 .......... Potential impacts of quarrying activities and typical mitigation measures Table 12.19 ............... Summary of receptors with potential impact from the Application Site Table 12.20 ........................................... Summary of potential impacts to nearby waterbodies Table 12.21 ........................................................... Watercourses within the radius of influence Table 12.22 ................................................................................................... Summary of impacts Table 12.23 ................................... Assessment Summary of Residual Environmental Effects Study Area 12.1.8 The study area is the Application Site (which is currently greenfield) and, when considering potential receptors, the area that lies within 4 km of the Application Site. Much of the content of this chapter focusses on the area shown in Figure 12.1 which is where the identified receptors are located. Figure 12.1 also shows the proposed excavation areas. CEMEX UK Operations February 2020 4 Land south of the A513, Orgreave, Alrewas 12.2 Methodology Previous Assessment Stages 12.2.1 No previous impact assessments relevant to the Application Site have been identified. Legislation and Planning Policy Guidance 12.2.2 The HIA element of this assessment conforms to the requirements of Groundwater Protection (Environment Agency, 2017) with regards to the technical approach to ensure the protection of groundwater in the vicinity of the Application Site. 12.2.3 The FRA element of this assessment has been written and submitted in accordance with guidelines laid out in the Planning Practice Guidance (PPG) (Department for Communities and Local Government, 2014) for the National Planning Policy Framework (NPPF) (Department for Communities and Local Government, 2012). The principal objective of the FRA element is to demonstrate that the Proposal will not increase the flood risk at the Application Site or elsewhere. 12.2.4 Site-specific calculations (see Appendix 5.7) have been performed to estimate surface water runoff generation for the 1 in 100 year event plus allowance for climate change using the industry standard advice given in the NPPF and EA guidance. Where necessary, appropriate site-specific flood risk mitigation measures have