Phase 1 Land Contamination Assessment
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Appendix A PHASE 1 LAND CONTAMINATION ASSESSMENT REPORT NO 70023030-001 PHASE 1 PRELIMINARY RISK ASSESSMENT STUDLAND BAY, DORSET CONFIDENTIAL SEPTEMBER 2016 PHASE 1 LAND CONTAMINATION ASSESSMENT STUDLAND BAY, DORSET NATIONAL TRUST Report (Version 1.2) Confidential Project no: 70023030 Date: September 2016 – WSP | Parsons Brinckerhoff Mountbatten House, Basing view, Basingstoke, RG21 4HG Tel: +44(0) 1256 318667 Fax: +44(0) 1256 318700 www.wspgroup.com www.pbworld.com QUALITY MANAGEMENT ISSUE/REVISION FIRST ISSUE REVISION 1 REVISION 2 REVISION 3 Remarks Draft for Comment Date 11/07/16 23/08/16 26/09/16 Prepared by R Jones M Weil M Weil Signature Checked by R Hares M Weil M Weil Signature Authorised by P Dowson D Jenkins R Hares Signature Project number 70023030 70023030 70023030 Report number 70023030-001 70023030-002 70023030-003 File reference M:\_SOIL & GROUNDWATER\_PR OJECTS\Contam\7002 3030 Studlands\(6) Reporting\Report ii TABLE OF CONTENTS EXECUTIVE SUMMARY .............................................................................1 1 INTRODUCTION ...........................................................................3 1.1 AUTHORISATION AND PURPOSE OF ASSESSMENT ................................. 3 1.2 AIMS ............................................................................................................... 3 1.3 SCOPE OF WORKS ....................................................................................... 3 1.4 SOURCES OF INFORMATION ....................................................................... 4 1.5 LIMITATIONS ................................................................................................. 4 2 SUMMARY OF THE SITE AND SURROUNDING AREA .............5 2.2 SITE WALKOVER .......................................................................................... 6 3 ENVIRONMENTAL SETTING ......................................................7 3.1 GEOLOGY ...................................................................................................... 7 3.2 HYDROGEOLOGY AND HYDROLOGY ......................................................... 8 3.3 DESIGNATED ECOLOGICAL SITES AND OTHER SENSITIVE LAND USES .............................................................................................................. 9 3.4 PRELIMINARY HYDROGEOLOGICAL MODEL ............................................. 9 4 POTENTIALLY CONTAMINATIVE LAND USES .......................10 4.1 SITE USE...................................................................................................... 10 4.2 LAND USES IN THE SURROUNDING AREA ............................................... 11 4.3 SITE HISTORY ............................................................................................. 11 4.4 CONSULTEES.............................................................................................. 14 4.5 UNEXPLODED ORDNANCE ........................................................................ 14 5 PRELIMINARY CONCEPTUAL MODEL ....................................15 5.1 INTRODUCTION ........................................................................................... 15 5.2 POTENTIAL CONTAMINANT SOURCES ..................................................... 15 PHASE 1 LAND CONTAMINATION ASSESSMENT WSP | Parsons Brinckerhoff National Trust Project No 70023030 Confidential September 2016 iii 5.3 POTENTIAL RECEPTORS ........................................................................... 16 5.4 PLAUSIBLE CONTAMINANT LINKAGES .................................................... 16 5.5 GEOTECHNICAL CONSTRAINTS................................................................ 17 6 CONCLUSIONS AND RECOMMENDATIONS ...........................18 6.2 ENVIRONMENTAL RISKS AND CONSTRAINTS ......................................... 18 6.3 RECOMMENDATIONS ................................................................................. 19 PHASE 1 LAND CONTAMINATION ASSESSMENT WSP | Parsons Brinckerhoff National Trust Project No 70023030 Confidential September 2016 iv TABLES TABLE 2-1: SITE INFORMATION ...................................................................................... 5 TABLE 3-1: UNDERLYING GEOLOGY .............................................................................. 7 TABLE 3-2: SUMMARY OF GROUND HAZARDS .............................................................. 7 TABLE 4-1: CURRENT POTENTIAL ON-SITE CONTAMINATIVE LAND USES, ACTIVITIES AND INCIDENTS......................................................... 10 TABLE 4-2: SUMMARY OF POTENTIAL LAND USES, ACTIVITIES AND INCIDENTS IN THE IMMEDIATE SURROUNDING AREA .................................. 11 TABLE 4-3: SUMMARY OF OFF-SITE PERTINENT HISTORY OF AREAS SURROUNDING THE SITE............................................................. 13 TABLE 5-1: POTENTIAL PLAUSIBLE SOURCES OF CONTAMINATION ........................ 15 TABLE 5-2: PLAUSIBLE CONTAMINANT LINKAGES...................................................... 16 TABLE 5-3: POTENTIAL GEOTECHNICAL CONSTRAINTS ............................................ 17 APPENDICES APPENDIX A LIMITATIONS APPENDIX B PHOTOGRAPHIC RECORD APPENDIX C ENVIROCHECK REPORT APPENDIX D MOD CORRESPONDENCE PHASE 1 LAND CONTAMINATION ASSESSMENT WSP | Parsons Brinckerhoff National Trust Project No 70023030 Confidential September 2016 1 EXECUTIVE SUMMARY WSP | Parsons Brinckerhoff (WSP) was instructed by National Trust (the Client), to undertake a Phase 1 preliminary land contamination risk assessment of a section of land subject to coastal erosion at Studland Bay, Dorset (the Site). WSP understands that the Client proposes to assess the suitability of the continued use of the Site as a recreational facility under the consideration of continued coastal erosion and, as such, an assessment is required to assess possible environmental liabilities associated with potential land contamination. The Site currently comprises a stretch of coast along Studland Bay approximately 180 m in length managed by National Trust. A number of small National Trust buildings and facilities occupy the coastline including a café, store, toilets and shed. Historically, it is known that Studland Bay was used as a WW2 military training ground in the lead up to D-Day. Based on the findings of the desk based assessment and site walkover, the following potential risks were identified from current or historical uses of the Site: Æ Potential asbestos containing materials in Made Ground; Æ Potential Unexploded Ordnance (UXO) and contamination associated with WW2 training grounds; Æ Potential contamination associated with current and historic recreational facilities on site e.g. lavatories; Æ Potential contamination from car park in southwest area of Site; and Æ Historical surrounding land use including WW2 military training and defence grounds in close proximity to the Site. The preliminary Conceptual Site Model indicates that a number of plausible potential contaminant linkages exist at the Site based on current land use. In the context of continued current site use as a recreational facility and in the event of continued coastal erosion, WSP considers that there is a Moderate risk to human health and controlled waters at the Site from environmental risks and constraints. This classification is based on a Medium severity of risk to receptors i.e. that if land contamination is present it may cause a chronic (long-term) risk to human health and pollution of sensitive controlled waters and a Likely probability of the risk occurring i.e. the pollutant linkage may be present and it is probable that the risk will occur over the long term. It is considered that these contaminant linkages are unlikely to present a significant risk or would lead to the site being designated as contaminated land under Part 2a of the Environmental Protection Act 1990, based on the current land use. High risk geotechnical constraints have been identified at the Site relating to coastal erosion/slope instability, UXO, Made Ground, obstructions associated with former foundations and buried services, and uncertainty in ground conditions. The classification is based on a Severe risk classification i.e. damage to buildings and infrastructure if the slope failed and a Likely probability of the risk occurring i.e. slopes have failed in previous storm events. However, in order to fully assess the potential constraints and risks identified to the Site and surrounding land if continued erosion occurs (in the event of no further coastal management measures to hold the existing line) it is considered that the following works will be required: Preliminary Risk Assessment WSP | Parsons Brinckerhoff National Trust Project No 70023030 Confidential September 2016 2 Æ A focused ground investigation (GI) should be undertaken to assess potential contamination linkages identified at the Site, including: x UXO safety clearance of all exploratory hole locations; x Soil sampling around the existing recreational facilities to assess the potential contamination risks to identified receptors; x Assessment of the chemical characteristics of the fill material for waste disposal options; and, x Preliminary geotechnical assessment of the slope stability. Æ The results of the GI should be assessed in a Ground Investigation Interpretative Report including a Generic Quantitative Risk Assessment. It is understood that the National Trust may also consider relocating existing facilities to the rear of the Site, in the vicinity of the car park location. An option also to be considered