PROPOSED RESIDENTIAL DEVELOPMENT FORGE ROAD, CHINLEY, DERBYSHIRE FOR WAINHOMES (NORTH WEST) LTD AUGUST 2017 GEO-ENVIRONMENTAL INVESTIGATION REPORT 17134/GEIR Forge Road, Chinley, Derbyshire. Wainhomes NW Ltd DOCUMENT STATUS Site Reference Forge Road, Chinley, Derbyshire. Title Geo-Environmental Investigation Report Client Wainhomes NW Ltd Project No. 17134/GEIR Report Version Final Issue Date Issued 24th August 2017 Issue Notes Issued for comment and approval Report Version Date Issued Issue Notes Report Version Date Issued Issue Notes Report Version Date Issued Issue Notes Report Version Date Issued Issue Notes Report No. 17134/GEIR REFA Consulting Engineers Forge Road, Chinley, Derbyshire. Wainhomes NW Ltd TABLE OF CONTENTS 1.0 INTRODUCTION 6.0 CONTAMINATION ANALYSIS & 1.1 Instructions ASSESSMENT CRITERIA 1.2 Object 6.1 Sampling 1.3 Scope 6.2 Range 1.4 Development Proposals 6.3 Laboratory 1.5 Services 6.4 Development Proposals 6.5 Analysis Range 2.0 THE SITE 6.6 Results 2.1 Location 6.7 Approach 2.2 Boundaries 6.8 Site Classification 2.3 Access 6.9 Criteria 2.4 Topography 2.5 Site Conditions 7.0 RESULTS OF ANALYSIS & 2.6 Trees QUALITATIVE RISK ASSESSMENT 2.7 Walkover Survey 7.1 Model 7.2 Results Summary 3.0 DESK STUDY 7.3 Metals & Inorganics 3.1 Historical Industrial Sites 7.4 Speciated PAH 3.2 Environmental Permits, Incidents & Registers 7.5 TPH (CWG) 3.3 Landfill Sites 7.6 BTEX 3.4 Current Land Uses 7.7 Sulphates 3.5 Hydrogeology & Hydrology 7.8 Ground Gases 3.6 Flooding 3.7 Environmentally Sensitive Areas 8.0 DISCUSSIONS 3.8 Geology 8.1 General 3.9 Ground Workings 8.2 Revised Conceptual Site Model 3.10 Background Soil Chemistry 8.3 Preliminary Remediation Proposals 3.11 Site History 8.4 Foundations 3.12 Anticipated Ground Conditions 8.5 Ground Floor Construction 3.13 Preliminary Conceptual Model 8.6 Flooding 4.0 SITE WORKS 9.0 CONCLUSIONS & 4.1 Intrusive Works RECOMMENDATIONS 4.2 Locations 9.1 Remediation 4.3 Records 9.2 Foundations 4.4 Targeting 9.3 Ground Floor Construction 9.4 Groundwater 5.0 GROUND CONDITIONS 9.5 SUDS 5.1 Topsoil 9.6 Further Work 5.2 Made Ground 5.3 Natural Strata 10.0 NOTES 5.4 Bedrock 5.5 Groundwater 5.6 Excavations 5.7 Contamination 5.8 Sampling 5.9 Index Testing 5.10 Ground Gases 5.11 SUDS Report No. 17134/GEIR REFA Consulting Engineers Forge Road, Chinley, Derbyshire. Wainhomes NW Ltd LIST OF TABLES Executive Summary Table 1 Review of Historical Maps Table 2 Anticipated Ground Conditions Table 3 Potential Ground Related Issues Table 4 Preliminary Conceptual Site Model Table 5 Initial Ground Investigation Strategy Table 6 Table of Chemical Testing Table 7 Summary of Contamination Analysis: Metals & Inorganics: Table 8 Summary of Contamination Analysis: Organics: Organics: PAH USEPA 16 Suite Table 9 Summary of Contamination Analysis: Organics: TPH (CWG) Suite Table 10 Summary of Contamination Analysis: Organics: BTEX Suite Table 11 Revised Conceptual Site Model LIST OF DRAWINGS 17134/01 Trial Pit Location Plan 17134/02 Trial Pit Location Plan (with sketch layout) 17134/03 Development Constraints Plan 1307WHD/Extra/SK01 Proposed Site Layout Plan LIST OF APPENDICES Appendix A Groundsure Enviro-Insight Report Appendix B Groundsure Geo-Insight Report Appendix C Ordnance Survey Maps Appendix D Trial Pit Location Plan Appendix E Trial Pit Journals Appendix F Trial Pit Location Plan (with sketch layout) Appendix G Development Constraints Plan Appendix H Proposed Site Layout Plan Appendix I Coal Authority Report Appendix J Exova Jones Laboratory Test Results Appendix K Professional Soils Laboratory Test Results Report No. 17134/GEIR REFA Consulting Engineers Forge Road, Chinley, Derbyshire. Wainhomes NW Ltd EXECUTIVE SUMMARY The site is irregular in shape and extends to an area of approximately Site 1.4 hectares. The site is located upon the southern side of Forge Road at the southern edge of Chinley Village NGR SJ 41855 93221 The site has a full recorded history of open rural and agricultural use with no development or issues. The land immediately to the west has Site History been occupied by a form mill which has now been demolished and remediated. This site is currently in the process of being developed by our clients. The investigations have extended to:- Walkover survey Investigations Desk study Extensive intrusive investigations by trail pitting techniques. Geotechnical & chemical analyses of soil samples Topsoil approximately 0.2m thick is present over almost the whole site (except at the south eastern corner). The very shallow superficial deposits comprise of glaciofluvial and alluvial deposits comprising of Ground Conditions soft / frim clays with sands and gravels bands and lenses typically extending to depths in the order of 1.5 – 2.0m below ground level. The site appears to be underlain by Glacial Till deposits as a basal superficial deposit Very significant water entries have been recorded at varying depths in almost all trial pits. The excavations have suffered “running sand” type conditions and severe instability. The ground water does appear to Groundwater exhibit a hydraulic gradient across the site in line with the topography. Ground water is expected to represent a very significant issue at this site. No evidence of any potentially hazardous contamination of the ground has been identified during these works. No on-site or off-site sources of Environmental potential ground gas emission have been identified and the site is classified as CS1 (Green) The site contains a series of mature and semi mature trees which may influence the development. A detailed arboraculturists report is strongly Trees recommended before any further works take place. Foundation precautions in accordance with NHBC Handbook chapter 4.2 are likely to be required. The shallow strata offers the potential to adopt traditional strip foundations BUT it is likely that all excavations will be impacted by heavy water ingress and this may limit the economic viability of a shallow spread footing solution. In the absence of a formal ground Foundations water management strategy the following foundations type are available: Raft foundation VSC (bottom fed system) subject to contactor agreement Piles and ground beams It is recommended that suspended ground floor construction be adopted for all properties located within this site. These floors may be of a pre cast concrete beam and block arrangement or of a suitably designed cast insitu reinforced concrete. In those areas where tree root Slabs effects are important it is recommended that a pre cast concrete beam and block type floor is utilised to allow for the provision of a suitable air void below the ground floor construction. It is considered that the site is not capable of adopting a soakaways SUDS system of surface water disposal and will need to connect to existing drainage sewers. There are no requirements for any formal remediation works to facilitate Remediation the residential development of this suite. This brief summary should not be assumed to represent a complete account of all the potential geo-environmental issues that may exist at the site. As such it is strongly recommended that the report be read in its entirety. Report No. 17134/GEIR REFA Consulting Engineers Forge Road, Chinley, Derbyshire. Wainhomes NW Ltd GEO-ENVIRONMENTAL INVESTIGATION WORKS FORGE ROAD, CHINLEY, 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 undertake a program of ground investigation works at a site situated off Forge Road, Chinley, Derbyshire which they intend to develop in a residential manner. 1.2 Object 1.2.1 The object of these investigations are as follows: To determine the engineering properties of the soils present within the site to form a basis upon which foundation and general infrastructure recommendations and design may be based; To enable sufficient information regarding ground conditions to be obtained from which risks to end users and the environment can be assessed; To utilise the information obtained from the investigations to provide recommendations for remediation measures where required. 1.3 Scope 1.3.1 The investigations considered within this report have comprised of the following elements: An initial environmental and engineering desk study based upon existing reports, services location information, geological, hydrogeology and hydrological information, a commercially available database and old Ordnance Survey maps; An initial walkover survey of the site has been undertaken prior to any intrusive investigations being commenced to determine the presence of any visible hazards or features which may affect the design of the ground investigation works; Undertake ground investigation works by trial pit excavation techniques; Determine the presence, nature and extent of any soil and groundwater contamination at the site; Determination of the engineering properties of the soils present within the site to form a basis upon which recommendations for foundations and infrastructure construction may be based; Identify the potential requirements for any remedial action, where required. 1.4 Development Proposals 1.4.1 We understand that it is our client’s intention that the site will be developed in a residential manner and an initial development proposal has been provided. A copy of the proposed site layout is appended to this report for general reference. It is however acknowledged that amendments may be made to these proposals as a result of planning consultations and commercial considerations. Report No. 17134/GEIR REFA Consulting Engineers Forge Road, Chinley, Derbyshire. Wainhomes NW Ltd It is however anticipated that the development will be carried out generally in accordance with the principles of the current layout. 1.4.2 At the present time the proposed site layout shows the site be developed by the construction of 13 no.