Varteg Hill Reclamation & Coal Recovery Scheme, Blaenavon
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Environment Glamorgan Power Co Ltd October 2014 Varteg Hill Reclamation & Coal Recovery Scheme, Blaenavon, South Wales Hydrogeological and Contaminated Land Assessment Interpretative Report Amended by: …………………………………………… . Checked by: ........................................................................ Philip Smart Murtala Bashir Technical Director (Hydrogeology) Principal Hydrogeologist Approved by: …………………………………………… . Claire Parkinson Regional Director Varteg Hill Reclamation & Coal Recovery Scheme, Blaenavon, South Wales Hydrogeological and Contaminated Land Assessment - Interpretative Report Rev No Comments Checked Approved Date by by 0 Final – Updated for inclusion in revised ES 22 April 2009 1 Modified final to support amended scheme mb clp 9 October 2014 Colmore Plaza, Colmore Circus Queensway, Birmingham, B4 6AT Telephone: 0121 262 1900 Website: http://www.aecom.com Job No 60327633 Reference 03 – Final Date Created August 2014 This document has been prepared by AECOM Limited for the sole use of our client (the “Client”) and in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AECOM Limited and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AECOM Limited, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AECOM Limited. f:\projects\geo - environmental - 60327633 varteg occs\03 execution\03 documents\03 geo-report 2014 report\word version\varteg hill reclamation geo-environment assessment report final 09102014.docx Table of Contents 1 Introduction ....................................................................................................................................................................... 4 1.1 Instruction .............................................................................................................................................................. 4 1.2 Project Objectives .................................................................................................................................................. 4 1.3 Sources ................................................................................................................................................................. 4 1.4 Limitations ............................................................................................................................................................. 5 2 Site Location and Background Information .................................................................................................................... 8 2.1 Site Location and Description ................................................................................................................................ 8 2.2 Environment Agency Conditions ............................................................................................................................ 8 2.3 History of the Site .................................................................................................................................................. 9 2.4 Proposed Site Works ........................................................................................................................................... 10 3 Environmental Setting .................................................................................................................................................... 12 3.1 Topography and Hydrology ................................................................................................................................. 12 3.2 Geology ............................................................................................................................................................... 12 3.3 Mining .................................................................................................................................................................. 14 3.4 Hydrogeology ...................................................................................................................................................... 17 3.5 Hydrology ............................................................................................................................................................ 18 4 Ground Investigation Works .......................................................................................................................................... 23 4.1 Methodology ........................................................................................................................................................ 23 4.2 Boreholes ............................................................................................................................................................ 23 4.3 Trial Pits ............................................................................................................................................................... 23 4.4 Sampling .............................................................................................................................................................. 24 4.5 Groundwater Instrumentation .............................................................................................................................. 24 5 An Interpretation of the Results of the Ground Investigation – Geology ................................................................... 27 5.1 Geology ............................................................................................................................................................... 27 5.2 Borehole BH1 ...................................................................................................................................................... 27 5.3 Borehole BH2 ...................................................................................................................................................... 28 5.4 Borehole BH3 ...................................................................................................................................................... 28 5.5 Borehole BH4 ...................................................................................................................................................... 28 5.6 Borehole BH5 ...................................................................................................................................................... 29 6 6 An Interpretation of the results of the ground investigation - Hydrogeology ........................................................ 31 6.1 Introduction .......................................................................................................................................................... 31 6.2 Groundwater levels .............................................................................................................................................. 31 6.3 Summary ............................................................................................................................................................. 33 6.5 Groundwater Quality ............................................................................................................................................ 35 6.6 Surface Water ...................................................................................................................................................... 37 7 An Interpretation of the Results of the Ground Investigation – Ground Contamination .......................................... 40 7.1 Introduction .......................................................................................................................................................... 40 7.2 Data Assessment................................................................................................................................................. 41 7.3 Leachate Test ...................................................................................................................................................... 44 7.4 Statistical Analysis ............................................................................................................................................... 46 7.5 Summary ............................................................................................................................................................. 47 8 Conceptual Site Model .................................................................................................................................................... 50 8.1 Introduction .......................................................................................................................................................... 50 8.2 Conceptual Model of Hydrology and Hydrogeology ............................................................................................. 50 8.3 Conceptual Model for Contaminated Land .......................................................................................................... 51 9 An Assessment of the Impact of the Proposed Scheme on Controlled Waters ........................................................ 54 9.1 Hydrology and Hydrogeology .............................................................................................................................. 54 9.2 Proposed