Tan Yard, Longridge Phase 1 Land Quality Assessment
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Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment G1770-R-01 29 July 2013 PSA Design Limited Tel. 01772 786066 The Old Bank House Fax. 01772 786265 6 Berry Lane Longridge www.psadesign.co.uk Preston PR3 3JA [email protected] Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment Document Control Sheet Tan Yard, Longridge Phase 1 Land Quality Assessment Job Date Issue Copy G1770 29 July 2013 G1770-R-01-o Originator…… …. Dr JS Birtwhistle BSc PhD FGS CGeol Checker.…… .. DL Wallbank BEng CEng MICE Approver…… .. Dr JS Birtwhistle BSc PhD FGS CGeol Copyright PSA Design Ltd. All rights reserved. No part of this report may be copied or reproduced by any means without prior written permission from PSA Design. If you have received this report in error, please destroy all copies in your possession or control and notify PSA Design. This report has been prepared for the exclusive use of the commissioning party and unless otherwise agreed in writing by PSA Design, no other party may use, make use of or rely on contents of the report. No liability is accepted by PSA Design for any use of this report, other than for the purposes for which it was originally prepared and provided. Opinions and information provided in the report are on the basis of PSA Design using due skill, care and diligence in the preparation of the same and no explicit warranty is provided as to their accuracy. It should be noted that and it is expressly stated that no independent verification of any of the documents or information supplied to PSA Design has been made. Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment CONTENTS Chapter Title 1 Preface 2 Introduction 3 Site Description 4 Historical Site Information 5 Environmental Setting 6 Hazard Assessment 7 Conclusions & Recommendations 8 Report Limitations DRAWINGS Drawing No. Title G1770/01 Site Location Plan G1770/02 Current Site Features Plan G1770/03 Development Layout Plan G1770/05 Preliminary Conceptual Site Model APPENDICES Appendix Title A Groundwise Report- Historical information B Groundwise Report- EnviroInsight C Groundwise Report- GeoInsight D Environment Agency Website information E Risk Assessment Method F Photographs Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment 1.0 PREFACE The site is located off Tan Yard, Longridge. PR3 3TA. (NGR 361270 437740). Site occupies an area of approximately 0.31 hectares. PSA Design were commissioned by Mrs Corbet to provide a Phase 1 Land Quality Assessment of the site. It is understood that consideration is being given to the redevelopment of the site as a residential development with associated car parking and landscaping. A development layout plan has been provided, which is included in this report as Drawing No. G1770/03. PSA Design’s investigation included a review of Groundwise data and Environment Agency searches. A summary of salient geo-environmental issues is provided in the table below. Issue Remarks Former uses Former uses of site have been a quarry, prior to recent inactivity on the site. The presence of several landfills within 250m of the site represents a medium risk of ground gas generation. Therefore, in accordance with CIRIA C665, and in Hazardous Gas view of the nature of the residential development, it is recommended that a minimum of six gas monitoring visits be undertaken over a three month period. Not within a mining area. Presence of several sandstone quarries within a 250m Mining & Quarrying radius of the study site. The site does not lie within an Environment Agency Flood Plain and is not likely Flooding & Drainage to flood in extreme flood events. Site drainage is likely to enter the existing drainage network. Anticipated Ground Thin fill deposits over sandstone/siltstone rock of the Carboniferous. Conditions Anticipated One potential source of contamination risk from infill materials. Contamination Preparatory Works Re-grading of site for purpose. Removal of vegetation. Strip footing foundations to competent bearing strata are anticipated to be the Anticipated Foundation most economic foundation solutions across the site subject to confirmatory site Solutions investigation. Intrusive investigation comprising window sampler boreholes across site, with Recommendations for gas/groundwater monitoring installations. Chemical soils analysis, with Ground Investigation subsequent gas and groundwater monitoring. Potential deeper foundations in localized fill. Shallow rock-head may be difficult Geotechnical Issues to excavate. Mature trees to margins may affect foundation depth and/or root barrier specification, dependent upon ground conditions. At this stage, anticipated significant developer abnormal costs relating to geo- environmental issues at the site are: • Capping of proposed gardens and landscaped areas with uncontaminated subsoil/topsoil, possibly re-used from site won sources or imported. • Removal and treatment/disposal of localised contaminated soils, if present. • Allowance for gas protection measures, prior to monitoring exercise 1 Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment Some further work is required, most notably: • Intrusive ground investigation • Services Search • Topographic Survey, including tree survey 2 Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment 2.0 INTRODUCTION 2.1 Terms of Reference 2.1.1 PSA Design were commissioned by Mrs Corbet to carry out a Phase 1 Land Quality Assessment at land off Tan Yard, Longridge. This report is in response to outline planning concerns from Ribble Valley Borough Council. 2.1.2 The agreed scope of works included: • A site walkover and inspection • An assessment of land use history • Determination of the site’s environmental setting • Assessment of anticipated ground conditions, including potential contaminants • Assessment of anticipated foundation and engineering issues associated with redevelopment for an residential end-use • Provision of recommendations for an appropriate ground investigation 2.2 Proposed Development 2.2.1 It is understood that consideration is being given to the redevelopment of the site a single domestic residence, with associated gardens and infrastructure. A development layout plan has been provided (Drawing No. G1770/03). 3 Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment 3.0 SITE DESCRIPTION 3.1 General 3.1.1 The site location is shown on Drawing Number G1770/01. Site details are summarised in the Table below. Current site layout plan shown in Drawing Number G1770/02. Detail Remarks Location Within NE outskirts of Longridge. Address Tan Yard, Longridge. PR3 3TA. NGR 361270 437740 Area 0.31 ha Known None made available. services 3.2 Site Features 3.2.1 A PSA Design Engineer completed a walkover survey of the site on the 17th July 2013 and the salient features are presented below. A selection of site photographs are included in the report as Appendix F. 3.2.2 The existing site is currently unused, with no development on the site. 3.2.3 Grassed vegetation is found within central southern areas of the site, with various mature trees and shrubs along the N, E and particularly the NW perimeter of the site. Himalayan Balsam noted within small patches within the woodland/shrub areas to the central N boundary area. 3.2.4 Ground is on various levels within the site, with the SW area, close to Tan Yard on a flat lower terrace, with the ground rising to the W in a second flat (grassed) terrace area, approximately 2m higher than Tan Yard highway. The ground to the N and E of this higher terrace rising again steeply to the site boundary. Due to the dense nature of the NW woodland, it is difficult to judge the ground level within the thin development strip to the NW of the main site area. The land to the W of the site boundary rises steeply, whilst the ground to the S and N drops away gradually. 3.2.5 Access to site off highway, Tan Yard. No hard-standing on the site. 3.2.6 Some bare vegetation patches within the site show fill materials within the higher parts of the NE area of the site, a very gravelly clay fill. To the N of the site within the caravan park, there appears to be a rock outcrop at the surface. A single house is present to the SE of the site. 3.2.7 Existing salient features are summarised in the Table below and shown in Drawing Number G1770/02. 4 Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment Feature Remarks Current Access Tan Yard, to the S. Topography Terraced and undulating, on various levels. Approximate areas 3100 m2 – Grass & Vegetation Nature of Mixed, some open to E &S, with wood/wire fence and hedging/trees along boundaries boundary with neighbouring properties. Surrounding land NESW – Rural residential. Caravan park to N. uses 3.3 Site Operations 3.3.1 No current operations on site and therefore not considered to represent a significant source of ground contamination. 5 Mrs I Corbet Tan Yard, Longridge Phase 1 Land Quality Assessment 4.0 HISTORICAL SITE INFORMATION 4.1 In order to investigate the development history and previous land uses at the site and immediate surrounding land, site centred extracts from Ordnance Survey (OS) plans dating back to 1846 were examined. These plans are presented in Appendix A to this report. The Table below provides a summary of the salient points relating to the history of the site with respect to the proposed end use. It is not the intention of this report to describe in detail all the changes that have occurred on or adjacent to the site. Significant former uses/operations are highlighted in bold text for ease of reference. Date(s) Site Surrounding Land Tootle Height Sandstone Quarry to immediate N of site. Highway running E-W through 1846 Holly Hall to E of site, with Delf Cottages to SW.