Zog Brownfield Ventures Ltd Drummond Park, Ludgershall Preliminary Geo-Environmental Assessment
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entran Zog Brownfield Ventures Ltd Drummond Park, Ludgershall Preliminary Geo-environmental Assessment Environmental Transportation entran Zog Brownfield Ventures Ltd Drummond Park, Ludgershall Preliminary Geo-environmental Assessment Revision Date Notes Author Checked Approved 2 October 2010 Report reference DH RE AK, ND TEC1006005.001.01 3 November 2010 Report reference DH RE ND TEC1006005.001.02 Entran Limited Eden Lodge Studios Eden Office Park Chapel Pill Lane Ham Green Bristol BS20 0BX T: 01275 375 007 F: 01275 376 333 www.entranltd.co.uk entran CONTENTS PAGE 1! INTRODUCTION 1! 2! SITE DESCRIPTION 3! 3! SITE HISTORY 7! 4! ENVIRONMENTAL SETTING 10 ! 5! SUMMARY OF PREVIOUS INVESTIGATIONS & ASSESSMENTS 19! 6! OUTLINE CONCEPTUAL MODEL 20 ! 7! GROUND ENGINEERING 26 ! 8! POTENTIAL GROUND SOURCE ENERGY 28 ! 9! CONCLUSIONS AND RECOMMENDATIONS 31 ! Figures Figure 1 - Site Location Plan Figure 2 - Existing Site Layout – Key Features Figure 3 - Site Walkover Photograph Locations Appendices Appendix A - Site Photographs Appendix B - Historical Maps Appendix C - GroundSure® Appendix D - British Geological Survey Records Appendix E - Correspondence Appendix F - Risk Evaluation entran 1 INTRODUCTION Terms of Reference 1.1 Entran Ltd has been commissioned by Zog Brownfield Ventures Ltd to undertake a preliminary geo-environmental assessment of the site at Drummond Park, Ludgershall. This report has been prepared by Tweedie Evans Consulting Ltd in association with Entran Ltd. Background 1.2 The site is located off the A342 on the western edge of Ludgershall, approximately 10km north-west of Andover. The site is centred at National Grid Reference 425800, 150900 and the nearest postcode is SP11 9RT (Figure 1). The area of the site is approximately 13.3Ha and is elevated at around 135m to 145m Above Ordnance Datum (AOD). 1.3 The site is understood to be a former Ministry of Defence Medical Supplies Depot (MoD Medical Supplies Agency) and it is proposed to develop the site for residential use, comprising the construction of approximately 500-550 residential units 1.4 The aim of these works is to provide a review of preliminary information on geo- environmental and engineering conditions and constraints associated with the site with regard to the proposed development. Scope of Works 1.5 The scope of work undertaken as part of this report is presented below: Preliminary Risk Assessment. This phase of assessment involves development of an initial site conceptual model, based on desk study research and a site reconnaissance survey, in order to establish whether or not there are potentially unacceptable risks, and also whether or not further action is required. 1.6 The above scope of work has been undertaken in accordance with current guidance such as CLR 11 ‘Model Procedures for the Management of Land Contamination’ (Environment Agency, 2004), and BS10175:2001. 1.7 The report is presented in the following format. Preliminary Risk Assessment: Section 2 – Site Description Section 3 – Site History Section 4 – Environmental Setting 1 entran Section 5 – Summary of Previous Investigations & Assessments Section 6 – Outline Conceptual Model Preliminary Geotechnical Assessment: Section 7 – Ground Engineering Considerations Preliminary Ground Source Energy Feasibility Assessment: Section 8 – Potential Ground Source Energy Section 9 - Conclusions and Recommendations 2 entran 2 SITE DESCRIPTION Site Location 2.1 The site is located on the western edge of Ludgershall (Figure 1) and is bounded by the following features (Table 2.1): Table 2.1: Site Boundary Features Direction from Site Description North A342 followed by arable fields, including a dismantled railway. East Small wooded area followed by rail lines, further woodland and residential properties. South Rail lines followed by a grassed area, a wooded area and open land beyond, currently understood to be developed for commercial use. West Arable fields with open land towards the southern end of the western boundary. Land Use and Site Condition 2.2 A site reconnaissance survey was undertaken on 29 June 2010. A summary of the observations is presented below with the key features observed during the walkover survey shown on Figure 2. Photographs taken during the site reconnaissance survey are presented in Appendix A with photograph locations shown on Figure 3. Photographs 1 to 20 provide general views of the site conditions, while Photographs 21 to 53 provide detail of some of the potential significant features observed at the site. Current Site Use 2.3 The site is located off the A342 on the western edge of Ludgershall (Figure 1). The site is located on a former Ministry of Defence (MoD) site used predominantly as a medical supplies depot prior to the site’s disposal. The site is currently split into two areas, separated by a military road running in a north-east / south-west direction, which is utilised by the public. The southern part of the site currently consists of a number of warehouses, storage areas, offices and vehicle servicing areas while the northern half of the site is understood to have been utilised for accommodation, medical and dental services and a blood support depot. The western part of the site is currently 3 entran covered with thick vegetation including deciduous mature trees, while to the north is a former sports field. A plan indicating the current site layout is presented in Figure 2. 2.4 During the site reconnaissance survey, a number of potentially significant features were observed, including fuel storage tanks, boilers, cold storage areas, paint, battery and gas stores, corrosive, biohazard and flammable material stores, electricity sub-stations, a vehicle wash-down area, underground water storage tanks, a battery charging area, vehicle servicing areas, electrical water pumps and a disused rail line running through the southern section of the site. Site Topography 2.5 The site was observed as rising in elevation toward the north-west with elevations of between ~132.5m AOD and ~137mAOD recorded along the south-eastern boundary and elevations of ~141.5mAOD to ~147.0mAOD at the northern boundary. Hard and Soft Landscaping 2.6 Much of the site was observed to be laid to a combination of concrete and tarmacadam hardstanding. Both were encountered as in various states of repair, but typically were recorded as being in a poor to moderate condition. 2.7 Minor areas of soft landscaping were observed during the walkover and a areas of trees were noted within the western and north-western parts of the site (Figure 2). Hydrocarbon Storage 2.8 Above ground fuel storage areas were observed in three locations at the site: the main boiler house, located in the south-eastern part of the site (Photographs 21 to 24), a smaller boiler house located in the central part of the site (Photographs 25 to 30) and small boiler houses located in two of the building in the northern part of the site (Photographs 33 to 36). It should be noted that no boiler room was observed in the third building located in the northern part of the site. In addition, areas of potential Liquefied Petroleum Gas (LPG) storage were recorded at two locations at the site: within the eastern part of the site (Photographs 31 and 32) and within the northern part of the site. 2.9 Two large (approximately 32000 litre) above ground storage tanks (ASTs) were observed near the central part of the south-eastern boundary, located within a brick bund (Photographs 21 and 22). At the time of the walkover the bund was observed to be filled with water 4 entran (Photograph 23), although, it should be noted that no evidence of hydrocarbon contamination (i.e. a hydrocarbon sheen) was observed at the time of the walkover survey. 2.10 Further fuel-oil storage was observed in the central part of the site (Photographs 26 and 27), where 3000 litre and 4000 litre ASTs were observed. An undrained oil sump was also observed (Photograph 27) within the fuel storage area. Strong olfactory evidence of hydrocarbon spillages was recorded within the adjacent boiler-room (Photograph 29). A fuel-oil delivery point was observed some 20m to the north of the fuel storage area. No evidence of significant hydrocarbon contamination from spillages was observed in this area. 2.11 A further large AST was observed in the northern section of the site near the northern boundary, contained within a brick bund (Photograph 33 and 34). A boiler house was observed below the main building of the northern part of the site (not entered during the walkover survey) and a second boiler house was observed in the accommodation building to the west. However, it should be noted that no boiler room was observed in the the blood support unit located in this part of the site and it is unclear how this building was heated. 2.12 Potential underground LPG storage was observed in the eastern part of the site (Photographs 31 and 32) and within the northern part of the site adjacent to the main building. LPG heaters were observed within the storage warehouses and offices in the eastern section of the site. 2.13 Minor fuel storage is understood to have been undertaken at the pumping station located adjacent to the below ground tanks within the eastern part of the site (Photographs 37 and 38). Further below ground water storage is understood to have taken place within the northern part of the site (adjacent to the entrance) although it is unclear how water was delivered to this location (Photograph 39). Other Features 2.14 Evidence of storage of potentially hazardous materials was observed during the site walkover, including the storage of paint, lithium batteries, corrosive materials, biohazards, petroleum spirit and flammable materials. 2.15 Two cold storage areas were observed within the main warehousing: three units were recorded within the central part (Photograph 40) and three newer refrigeration units were observed in the western part of the warehousing (Photograph 41).