PROPOSED RESIDENTIAL DEVELOPMENT HAYFIELD ROAD, NEW MILLS, DERBYSHIRE FOR WAINHOMES (NW) LTD SEPTEMBER 2017 COAL MINING RISK ASSESSMENT REPORT FOR A DEVELOPMENT SITE 17004/CMRA/A Hayfield Road, New Mills, Derbyshire Wainhomes (NW) Ltd DOCUMENT STATUS Site Reference Hayfield Road, New Mills, Derbyshire Title Coal Mining Risk Assessment Report Client Wainhomes (NW) Ltd Project No. 17004/CMRA Report Version Coal Mining Risk Assessment Report Date Issued 11th January 2017 Issue Notes Issued for comment and approval Report Version Revision B Date Issued 15th September 2017 Issue Notes Including updated site layout Report Version Date Issued Issue Notes Report Version Date Issued Issue Notes Report Version Date Issued Issue Notes Report No. 17004/CMRA/A Coal Mining Risk Assessment REFA Consulting Engineers Hayfield Road, New Mills, Derbyshire Wainhomes (NW) Ltd TABLE OF CONTENTS 1.0 INTRODUCTION 1.1 Instructions 1.2 Objectives 1.3 Sources Of Information 1.4 Development Proposals 1.5 Limitations Of Report 2.0 THE SITE 2.1 Location 2.2 Coal Authority Report 2.3 Geology 2.4 Coal Authority Online Records 2.5 BGS Borehole Viewer 3.0 COAL MINING RISKS 3.1 General Risks 3.2 Collapse of Shallow Workings 3.3 Coal Mine Workings 3.4 Consolidation of Relict Workings 3.5 Migration of Mine Gases 3.6 Failure of Mine entries 3.7 Spontaneous Combustion 4.0 PROPOSED MITIGATION STRATEGY 4.1 Investigation Proposals 5.0 CONCLUSIONS 5.1 Recommendations LIST OF APPENDICES Coal Authority Report Investigation Proposals Drg No. OS-001 Report No. 17004/CMRA/A Coal Mining Risk Assessment REFA Consulting Engineers Hayfield Road, New Mills, Derbyshire Wainhomes (NW) Ltd COAL MINING RISK ASSESSMENT REPORT HAYFIELD ROAD, NEW MILLS, DERBYSHIRE. 1.0 INTRODUCTION 1.1 Instructions 1.1.1 We are instructed by Wainhomes (NW) Ltd, Kelburn Court, Daten Park, Birchwood, Warrington, WA3 6UT to carry out a formal coal mining risk assessment to determine possible coal mining risks associated with a site off Hayfield Road, New Mills, Derbyshire. We understand that the site is to be developed in a residential manner utilising traditional residential properties. This risk assessment has been prepared in support of a planning application to develop the site in a residential manner. 1.2 Objectives 1.2.1 This CMRA has been carried out in accordance with the principal recommendations presented in the Coal Authority Coal Mining Risk Assessment Template (January 2011). This report represents a desk study approach to consider publically and readily available information regarding the geology of the site and the likelihood of coal mining operations having taken place within influencing distance of the site in the past. 1.2.2 Where results of the desk study suggest possible coal mining operations or where insufficient corroborative data is available to confirm the site is free from mining influences recommendations are to be made regarding investigations which may be required to positively determine the long term coal mining stability of the site. 1.3 Sources Of Information 1.3.1 This report has been prepared using information from the following sources:- Online British Geological Survey maps and data; Geological Survey of England and Wales 1:50,000 series sheet 99 Chapel on le Frith dated 1987; Coal Authority Mining Report dated 9th January 2017; Coal Authority interactive map viewer; British Geological Survey online borehole records; Google Earth aerial imagery. 1.4 Development Proposals 1.4.1 At the time of preparation of this report details of the formal proposed site layout plan for the residential development was unavailable. We understand however that the whole of the site area is to be subject to a programme of traditional residential development comprising of a combination of detached, semi-detached and mews type properties which are of a traditional construction. It is therefore anticipated that the whole of the development area will be subject to re-development and no significant portions of the site are to be set aside as open space. 1.4.2 It is acknowledged that the development proposals for this site may be amended as a result of local planning and commercial requirements. It is however anticipated that the recommendations made within this report will apply to this site regardless of the types of development which are subsequently proposed. Report No. 17004/CMRA/A Coal Mining Risk Assessment REFA Consulting Engineers Hayfield Road, New Mills, Derbyshire Wainhomes (NW) Ltd Variations within the proposals may result in variations of the recommendations regarding further intrusive works etc. 1.5 Limitations Of The Report 1.5.1 This report is a desk study report which has been prepared using readily available information in accordance with the project stage requirements, budget and time scales. The opinions expressed in this report and the comments and recommendations given are based upon the information obtained from the desk assessment. 1.5.2 The information, views and conclusions drawn concerning the site are based in part on information supplied to Robert E Fry & Associates Ltd (REFA) by other parties. REFA has proceeded in good faith on the assumption that this information is accurate. REFA cannot and does not guarantee the authenticity or reliability of third party information it has relied on. REFA accepts no liability for any inaccurate conclusions, assumptions or actions taken resulting from any inaccurate information supplied to REFA from others. 1.5.3 The copyright of this report (including its electronic form) shall remain vested in REFA but the client shall have a license to copy and use the document for the purpose for which it was provided. REFA shall not be liable for the use by any persons of the document for any purpose other than that for which the same was provided by REFA. Any persons so using or relying upon this document for such other purposes do so at their own risk. This document shall not be reproduced in whole or in part or relied upon by third parties for any use whatsoever without the express written authority of REFA. 2.0 THE SITE 2.1 Location 2.1.1 The site is approximately rectangular in shape and extends to an area of some 3.7 hectares. The centre of the site is situated at approximate National Grid Reference SK 01090 86546 within a predominately mixed agricultural/residential area. Its location is shown in figure 1 below. Figure 1 - Site Location Report No. 17004/CMRA/A Coal Mining Risk Assessment REFA Consulting Engineers Hayfield Road, New Mills, Derbyshire Wainhomes (NW) Ltd 2.2 Coal Authority Report 2.2.1 A non-residential mining report has been prepared for the site by the Coal Authority and a copy of this report is appended to this risk assessment for reference. The Coal Authority has confirmed that they hold no records of any coal mining activity which may affect the site in the future. 2.2.2 The Coal Authority have however advised that the site lies within an area where they believe that coal may be at or close to the surface. It is possible that this coal may have been worked at some period in the past though the Coal Authority does not hold any formal records of such workings. The Coal Authority have further advised that the potential presence of coal workings at shallow depth below the site should be considered prior to any site works or future development activity. 2.2.3 The Coal Authority have further advised that if development proposals are being considered, technical advice relating to both the investigation of coal and former coal mines and their treatment should be obtained before beginning work on site. All proposals should apply good engineering practice developed for mining areas. No developments should be undertaken that intersects, disturbs or interferes with any coal or mines of coal without the permission of the Coal Authority. Further advice is given with regard to the possible generation and migration of toxic and explosive gases which may pose a potential hazard to the site, its future development and any adjoining properties. 2.3 Geology 2.3.1 The report prepared by the Coal Authority clearly draws attention to the possible presence of coal seams potentially lying at shallow depth within the proximity of the development area. It is therefore necessary to carefully consider the available records regarding the solid geology of the site and in particular records indicating the locations of any coal seams at outcrop of where coal seams may be inferred by other historical data. 2.3.2 Reference to the British Geological Map for this area indicates that the site is underlain by Carboniferous Westphalian (Coal Measures) strata which is recorded to contain coal seams of an economic merit. 2.3.3 The geological map confirms the presence of faulting to the north, south and west of the site suggesting that the site and its immediate vicinity are located within a fault block. The geology is indicated to dip towards the east, potentially at an angle of approximately 12 degrees though this may vary significantly locally. The Rough Rock gritstone is shown to outcrop to the west of the site and it is known that the top of the Rough Rock is marked by a marine band containing gastropod fossils along with a thin coal seam known as the Six Inch Mine. A succession of mudstones, siltstones and shales is then indicated to be present within the central area of the site with the Woodhead Hill Rock or Crashaw Sandstone lying to the east. Within the Woodhead Hill Rock the Yard Mine is indicated to be present at a conjectured outcrop. 2.3.4 The indication of a conjectured outcrop to a coal seam indicates that the position of the outcrop has been determined from assessment of the accessible geological structures within the vicinity.