Silvertown Garage and Ambulance Station, North Woolwich Road
Total Page:16
File Type:pdf, Size:1020Kb
Silvertown Garage and Ambulance Station, North Woolwich Road, London 13 Triangle Business Park, Stoke Mandeville, HP22 5BL Tel: 01296 739400 Email: [email protected] ENVIRONMENTAL INVESTIGATION REPORT Report Prepared By: Report Reviewed By: James Edley James Skinner Subadra Consulting Ltd. Registered in Report IN11836 CL 003 England No. 4586038 Client: Silvertown Garage Ltd Date July 2020 Registered Office 13 Triangle Business Park, Stoke Mandeville, HP22 5BL Page 1 Silvertown Garage and Ambulance Station, North Woolwich Road, London 13 Triangle Business Park, Stoke Mandeville, HP22 5BL Tel: 01296 739400 Email: [email protected] Contents 1 Introduction......................................................................................................................................................................4 1.1 The Purpose of This Assessment.................................................................................................................... 4 1.2 The Scope of This Assessment........................................................................................................................ 4 1.3 Previous Reports Relating to the Site..............................................................................................................5 1.4 Proposed Development Plans.......................................................................................................................... 7 2 Desk Study Information................................................................................................................................................. 7 2.1 Site Description, Location and Setting.............................................................................................................7 2.2 Geology, Hydrogeology and Hydrology...........................................................................................................9 2.3 Site History.........................................................................................................................................................11 2.4 Additional Information...................................................................................................................................... 16 3 Site Walkover and Inspection.....................................................................................................................................17 3.1 Filing Station Area............................................................................................................................................ 17 3.2 Ambulance Station Walkover..........................................................................................................................20 3.3 6-8 Boxley Street (Adjacent Terraced House)............................................................................................. 21 4 Investigation Results....................................................................................................................................................22 4.1 Details of Our Investigation............................................................................................................................. 22 4.2 Rationale for Borehole Locations................................................................................................................... 23 4.3 Site Geology...................................................................................................................................................... 24 4.4 Visual and Olfactory Signs of Contamination...............................................................................................25 4.5 Groundwater Monitoring Data.........................................................................................................................25 4.6 Hazardous Ground Gases Assessment........................................................................................................25 5 Chemical Analysis Results......................................................................................................................................... 27 5.1 Chemical Analysis Rationale.......................................................................................................................... 27 5.2 Soil Analysis Results........................................................................................................................................ 28 5.3 Groundwater Analysis Results........................................................................................................................32 5.4 Drinking Water Supply Analysis Results.......................................................................................................35 6 Conceptual Site Model................................................................................................................................................ 36 6.1 Summary of Investigation Findings................................................................................................................36 6.2 Conceptual Site Model.....................................................................................................................................37 7 Generic Quantitative Risk Assessment.................................................................................................................... 38 7.1 Summary of Viable Pollutant Linkages to be Assessed............................................................................. 38 Report IN11836 CL 003 Environmental Investigation Client: Silvertown Garage Ltd Date July 2020 Report Page 2 Silvertown Garage and Ambulance Station, North Woolwich Road, London 13 Triangle Business Park, Stoke Mandeville, HP22 5BL Tel: 01296 739400 Email: [email protected] 7.2 Generic Acceptance Criteria – Methodologies.............................................................................................39 7.3 Human Health Assessment.............................................................................................................................40 7.4 Generic Quantitative Risk Assessment - Environmental Receptors........................................................ 42 7.5 Environmental Receptors Assessment......................................................................................................... 42 8 Environmental Assessment Conclusions................................................................................................................. 44 9 Recommendations Relating to Future Redevelopment Works.............................................................................45 9.1 Recommendations for Future Environmental and Geotechnical Investigation Work............................ 47 List of Attachments Attachment One: Notice to Interested Parties Attachment Two: Site Plans and Borehole Logs Attachment Three: UXO Desk Study and Risk Assessment Attachment Four: Historical Maps Attachment Five: Public Utility Drawing Attachment Six: Chemical Analysis Certificates Report IN11836 CL 003 Environmental Investigation Client: Silvertown Garage Ltd Date July 2020 Report Page 3 Silvertown Garage and Ambulance Station, North Woolwich Road, London 13 Triangle Business Park, Stoke Mandeville, HP22 5BL Tel: 01296 739400 Email: [email protected] 1 Introduction 1.1 The Purpose of This Assessment The site is located on North Woolwich Road (A1020) in Silvertown, East London and comprises an operational petrol filling station, an ambulance station and an end-of-terrace residential property. We understand that Silvertown Garage Ltd proposes to sell the site freehold for future redevelopment. Although the exact nature of the development will be determined by the new owner, we understand it is likely to comprise a high density residential-led development, most likely comprising ground floor retail / commercial units and residential flats above. We have been commissioned by Silvertown Garage Ltd to carry out an environmental investigation of the site. The purpose of our investigation is to allow us to assess the quality of underlying soil and/or groundwater to determine whether any contaminants present might pose an unacceptable (long-term) risk to future site residents and/or any nearby environmental receptors. Our investigation is also designed to provide potential buyers with information relating to any adverse ground conditions and to address the likely requirements of conditions associated with future planning permission for the redevelopment. Our environmental assessment was undertaken in accordance with the guidelines presented in the Environment Agency, ‘Model Procedures for the Management of Land Contamination’1. and Environment Agency Guidance on Requirements for Land Contamination Reports2. Your attention is drawn to the Notice to Interested Parties included as Attachment One. 1.2 The Scope of This Assessment Our assessment of the site was carried out in the following parts: Desk study comprising a review of information that is readily available in the public domain; A review of previous environmental reports; The collection of public utility drawings for the sites locality to assist with locating public utilities that may be present and review of utilities drawings for the filling station area provided to us by our Client; A walkover survey to identify visual signs of pollution or potentially polluting activities; An intrusive site investigation comprising nine boreholes drilled using our GeoProbe direct-push