Phase 1 Geo-Environmental Audit
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Phase 1 Geo-Environmental Audit Land South of Branston, Burton-upon-Trent Branston East St Modwen Developments Ltd July 2011 Phase 1 Geo-Environmental Audit Branston East St Modwen Developments Ltd July 2011 Halcrow Group Limited Lyndon House, 62 Hagley Road, Edgbaston, Birmingham B16 8PE tel 0121 456 2345 fax 0121 456 1569 halcrow.com Halcrow Group Limited has prepared this report in accordance with the instructions of client St Modwen Developments Ltd for the client’s sole and specific use. Any other persons who use any information contained herein do so at their own risk. © Halcrow Group Limited 2011 Phase 1 Geo-Environmental Audit Document history Phase 1 Geo-Environmental Audit Branston East St Modwen Developments Ltd This document has been issued and amended as follows: Version Date Description Created by Verified by Approved by 00 31/05/11 Draft for client comment AGRL SKT 01 14/07/11 Final for issue AGRL SKT PR Phase 1 Geo-Environmental Audit Contents Executive Summary 1 1 Introduction 3 2 Results of Desk Study 6 2.1 Historical Land Use 6 2.2 Aerial Photographs 8 2.3 Results of Landmark Geo-Environmental Data Search 5 2.4 MAGIC 10 2.5 Natural England 11 2.6 Environment Agency 11 2.7 Coal Mining Report 12 2.8 Preliminary Ground Investigation 12 2.9 Previous Ground Investigations and Reports 12 2.9.1 Topsoil, Made Ground and Alluvium 12 2.9.2 Pulverised Fuel Ash (PFA) 13 2.9.3 Sand and Gravel 13 2.9.4 Mercia Mudstone Group 13 2.9.5 Groundwater 14 2.9.6 Information provided by Howard Sharp and Partners 14 2.10 Geology 14 2.11 Hydrogeology 15 3 Site Implications 17 3.1 Geotechnical Implications 17 3.2 Environmental Implications 17 4 Preliminary Risk Assessment 19 4.1 Identified Sources, Pathways and Receptors 19 4.1.1 Sources 19 4.1.2 Pathways 20 4.1.3 Receptors 20 4.2 Qualitative Risk Assessment 20 4.2.1 Assessment methodology 21 5 Conclusions and Recommendations 24 5.1 Summary 24 6 References 25 7 Figures 26 Phase 1 Geo-Environmental Audit Appendices Appendix A: Landmark Envirocheck Report; 34725405_1_1 Appendix B: Coal Mining Report: 00028695‐11 Appendix C: Correspondence with Staffordshire County Council Appendix D: Risk Categorisation (based on DETR, 1995) Phase 1 Geo-Environmental Audit Executive Summary This report describes the findings of a Phase 1 Geo – Environmental Audit for the Branston East site, located south of Branston, Staffordshire, between the Birmingham‐Derby Railway and the River Trent. The site is proposed to remain as open space and landscaping and will form part of a green link and resource between Branston Water Park in the west and Drakelow Nature Reserve east of the River Trent, within the proposed sustainable urban development and employment opportunity south of Branston. Historically the site was used as fields, then during the 1960s and 1970s the central part of the site and a localised area of the south of the site were used for extraction of sands and gravels (River Terrace Deposits). The resulting excavations were filled with Pulverised Fuel Ash (PFA) from the nearby Drakelow Power Station. Previous investigations in an adjacent site (Branston West, west of the railway line) have found PFA to be up to 8.5m thick and the strength to be variable with depth. Branston East has since been reinstated and is now used as arable land, with hedgerows/field boundaries and an area of ponds and vegetation. Natural deposits at the site are anticipated to comprise Alluvium, River Terrace Deposits (sands and gravels) and clays, mudstones and siltstones of the Mercia Mudstone Group. The site is adjacent to the River Trent that has a river quality of Grade C. The superficial River Terrace Deposits (sand and gravel) are classified by the Environment Agency as a Secondary Aquifer – A. The Mercia Mudstone Group is classified as a Secondary Aquifer – B. The northern end of the site is within a Total Catchment Source Protection Zone. The whole site is within the indicative floodplain of the River Trent. It is anticipated that groundwater is present at relatively shallow depth; in the adjacent Branston West site groundwater was encountered between 1.3 and 3.2m below ground level In Branston East the groundwater in the superficial River Terrace deposits is anticipated to be in hydraulic continuity with the River Trent. The Birmingham to Derby railway line forms the western site boundary and developments close to the railway line should not be undertaken without consultation with the appropriate authority. The preliminary risk assessment undertaken for Branston East (Section 4) shows that, with the current usage of the site as arable land, the risks to site users, visitors, surface and ground waters are generally low. There is the possibility that sewage sludge may have been spread on the land historically. If this is the case, heavy metals may be present in the topsoil. If future use as public open space rather than arable land is proposed, surface Rev: Final Version 01 Date: July 2011 1 P:\PJF116 - Branston\Docs\Outgoing\Reports\Phase 1 Branston East\Final version 01 July 2011\Branston East Phase 1 Geo-environmental Audit final Version 01.doc Phase 1 Geo-Environmental Audit sampling and testing of topsoil should be undertaken to determine whether or not such substances are present. The presence of PFA within the site may have led to leachable materials within the soil and/or groundwater. Sampling and testing of surface waters at their entry to the site and exit from the site will allow assessment to be made of effects of the Branston East site on surface water quality. Rev: Final Version 01 Date: July 2011 2 P:\PJF116 - Branston\Docs\Outgoing\Reports\Phase 1 Branston East\Final version 01 July 2011\Branston East Phase 1 Geo-environmental Audit final Version 01.doc Phase 1 Geo-Environmental Audit 1 Introduction In April 2011 St Modwen Developments Ltd commissioned Halcrow Group Ltd (Halcrow) to undertake a Phase 1 Geo‐Environmental Audit for the Branston East site, an area of land south of Branston, Burton‐upon‐Trent, Staffordshire, between the Birmingham‐Derby railway line in the west and the River Trent in the east. This report has been prepared for St Modwen Developments Ltd to support an outline planning application for the land south of Branston Land west of the railway line has been the subject of a number of reports, investigations and surveys over the years and where appropriate this information has been used in preparation of this report. The vision and concept for the Branston East site, as set out in East Staffordshire Borough Council’s Development Brief (ESBC, 2010/2011), is for the land to create a green link and resource. This link forms part of the proposed sustainable urban development and employment opportunity south of Branston, and continues the green link from the Bass Millennium Wood and Branston Water Park in the west to the Drakelow Nature Reserve east of the River Trent. The location of Branston East is shown in Figure 1. Summary details of the site are shown in Table 1‐1 below. Table 1-1: Site Summary Information Site Name and Branston East, Branston, Staffordshire Address Location The site is located at approximate National Grid Reference 422100E, 320100 N and is shown on the Site Location Plan, Figure 1. Current Uses The site is currently used as arable land and extends approximately 2km from north‐east to south‐west and between 100m and 650m from north‐west to south‐east. The extent of the site is shown on Figure 1. The site is bounded by the Birmingham to Derby Railway to the west and the River Trent to the east. A tributary to the River Trent forms the northern boundary and agricultural land lies to the south of the site. Google aerial photography accessed on 6 July 2011, dated 2010, showed the field adjacent to the south of the site having been apparently worked for sand and gravel extraction and Rev: Final Version 01 Date: July 2011 3 P:\PJF116 - Branston\Docs\Outgoing\Reports\Phase 1 Branston East\Final version 01 July 2011\Branston East Phase 1 Geo-environmental Audit final Version 01.doc Phase 1 Geo-Environmental Audit currently part‐filled with water. Bing aerial photography accessed on the same day, also dated 2010, for the same area shows the field south of the site as apparently unworked. The land west of the railway forms the Branston West site and is currently used for agriculture. Ground level within the site is typically 48mAOD (above Ordnance Datum) and the site is predominantly flat. Development The proposed development at the site is to retain the area Proposals for open space and landscaping and to form a green link and resource within the proposed Branston development, as described above. For the purpose of this report a Phase 1 Geo‐Environmental Audit comprises the following: • Desk Study in accordance with the recommendations of The Association of Geotechnical Specialists (AGS) Guide to Geo‐ environmental Reports (excluding services searches) • Searches of publicly accessible geo‐environmental records The purpose of a Phase 1 Geo‐Environmental Audit is, from readily available sources of information, to identify hazards and/or sources of potentially harmful substances and to determine the geological and hydrogeological conditions both beneath the site and in its vicinity. In order to establish environmental risk, a hazard/pathway/target relationship for contamination (if present) is tabulated. Additionally, the geotechnical conditions of the site have been reviewed from data held in published sources from which possible opportunities and constraints to future development have been evaluated.