Detailed Remediation Method Statement

Land at Five Oaks Lane

Chigwell Essex

Countryside Properties PLC

514 R02: Issue 1

July 2015

Green Earth Management Co Ltd

Title Detailed Remediation Method Statement Land at Five Oaks Lane, Chigwell, Essex

Prepared for Countryside Properties Plc Countryside house The Drive Brentwood Essex CM13 3AT

Confidentiality, Commercially Confidential copyright and reproduction This document has been prepared by Green Earth Management Company Limited in connection with a contract to supply goods and/or services and is submitted only on the basis of strict confidentiality. The contents must not be disclosed to third parties other than in accordance with the terms of the contract.

File reference 514

Report number 514 R02: Issue 1

Date 8th July 2015

Prepared by Green Earth Management Co Ltd East Gores Farm East Gores Road Coggeshall Essex CO6 1RZ

Name Signature Date

Author: D. Robson 08/07/2015

Reviewed by: P. Taylor 08/07/2015

Authorised by: L. Jackson 08/07/2015

Issue Record Project No 514 Project Name Five Oaks Lane, Chigwell, Essex Client Jackson Civil Engineering on behalf of Countryside Properties Plc Report Title Detailed Remediation Method Statement Report Date of Issue Author Reviewer Details of Changes Distribution No. Issue No. Countryside Properties Plc Jackson Civil Engineering R02 DR PT 08/07/15 Issue 1 Issue 1 EC Harris Arcadis London Borough of Redbridge

CONTENTS

CONTENTS ...... I TABLES ...... IV FIGURES AND APPENDICES ...... IV REPORT STRUCTURE ...... V 1 INTRODUCTION ...... 1 1.1. Project Details ...... 1 1.2. Objectives ...... 1 1.3. Scope of Work ...... 1 1.4. Previous Investigations ...... 2 1.5. Project Stakeholders ...... 2 1.6. Terms of Reference ...... 3 2 SITE DETAILS ...... 4 2.1. Site Setting ...... 4 2.1.1. Site Location ...... 4 2.1.2. Site Description ...... 4 2.1.3. Surrounding Area ...... 9 2.1.4. Topography ...... 9 2.2. Geology, Hydrogeology and Hydrology ...... 9 2.3. Ground Conditions ...... 10 2.3.1. Made Ground ...... 10 2.3.2. Clay ...... 11 2.4. Groundwater ...... 11 2.5. Contamination Conditions ...... 11 2.5.1. Conceptual Site Model – Summary of Linkages of Concern ...... 11 2.6. Pre-Remediation Risk Assessment ...... 12 3 DETAILED REMEDIATION STRATEGY...... 14 3.1. General ...... 14 3.2. Construction Considerations ...... 14 3.2.1. Cut and Fill ...... 14 3.2.2. Piling Works for Foundations ...... 15 3.3. Key Elements of Remediation Strategy ...... 15 3.4. Removal of Visible ACM (Bulk Products) ...... 16 3.5. Tree and Vegetation Clearance ...... 17 3.6. Clearance of Fly-Tipped Waste ...... 17 3.6.1. Disposal / Removal of Skip Waste ...... 17 3.6.2. Construction / Demolition Wastes ...... 18 3.6.3. Wood Waste ...... 19 3.6.4. LPG (Propane and Butane) Bottles ...... 19 3.6.5. ‘Mulch’ - shredded wood waste...... 19 3.7. Removal of Hotspots of Asbestos Contaminated Soils ...... 20 3.7.1. Plot 58 / 59 Fly-Tipped Soils ...... 21 3.7.2. Plot 42 Haul Road Materials ...... 21 3.8. Demolition ...... 29

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3.8.1. Demolition of Above Ground Structures ...... 29 3.8.2. Breakout of concrete hard standing, excavation of underground obstructions and crushing of site won hard materials ...... 29 3.8.3. Emptying and Removal of Above Ground Oil Storage Tanks ...... 29 3.8.4. Emptying of Septic Tanks and Cesspits...... 30 3.8.5. Perched Water Management ...... 30 3.9. Off-Site Disposal / Treatment of Japanese Knotweed (JK) ...... 30 3.9.1. Off-Site Disposal of Japanese Knotweed ...... 30 3.9.2. Cell Burial Method ...... 32 3.10. Recycling of Site Won Topsoil ...... 33 3.11. Excavation and Treatment of Potentially Contaminated Made Ground ...... 33 3.11.1. Complex Sorting Operations ...... 34 3.11.2. Ex-Situ Bioremediation ...... 34 3.11.3. Validation of Treated Soils for Re-Use ...... 35 3.12. Recycling of Aggregate ...... 35 3.13. Backfilling of Excavations ...... 35 3.14. Construction of Buried Services (Particularly Water Supply Network) ...... 35 3.15. Construction of Capping Layer in Gardens and Landscaping ...... 36 3.16. Ground Gas Risks and Hotspot Mitigation Strategy ...... 37 3.17. Discovery Strategy ...... 37 4 ENVIRONMENTAL PERMITTING AND REGULATORY CONSIDERATIONS ...... 39 4.1. General ...... 39 4.2. Re-Use of Site Derived Materials ...... 39 4.3. Code of Practise on Waste...... 39 4.3.1. Materials Management Plan ...... 40 4.4. Imported Materials ...... 40 4.5. Off-Site Disposal ...... 40 5 FOUNDATION WORKS RISK ASSESSMENT...... 41 5.1. Founding Options ...... 41 5.2. Associated Generic Pollution Scenario ...... 41 5.3. Refined Risk Assessment in relation to the Proposed Founding Method ...... 44 5.3.1. Pollution Scenario PS2 ...... 44 5.3.2. Pollution Scenario PS3 ...... 44 5.4. Conclusions ...... 45 6 VERIFICATION (VALIDATION) PLAN ...... 46 6.1. General ...... 46 6.2. Site Inspection / Supervision ...... 46 6.3. Verification Sampling ...... 46 6.3.1. Validation Testing Frequency for Soils (contamination) ...... 47 6.3.2. On-Site VOC Screening ...... 47 6.3.3. Material / Geotechnical Testing ...... 47 6.4. Chemical Validation Criteria for Soils (Soil Assessment Criteria) ...... 48 6.5. Laboratory Testing ...... 48 6.5.1. Chemical Laboratory ...... 48 6.5.2. Material and Geotechnical Testing ...... 49

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6.5.3. Quality Control ...... 49 6.6. Materials Management Plan ...... 50 6.7. Waste Transfer notes ...... 50 6.8. Imported Material Validation Testing ...... 50 6.9. Verification Reporting...... 50 7 HEALTH AND SAFETY ...... 52 7.1. General ...... 52 7.2. Site induction and Awareness ...... 52 7.3. Site Access ...... 52 7.4. Site Office and Messing ...... 52 7.5. Hours of Work ...... 52 7.6. Noise ...... 53 7.7. Site Supervision ...... 53 7.8. Welfare and Decontamination Facilities ...... 53 7.9. Personal Protective Equipment ...... 53 7.10. Wheel-Wash Facility and Staging Area ...... 54 7.11. Surface Water Management ...... 54 7.12. Dust Monitoring...... 54 7.13. Odour Control ...... 54 7.14. Health and Safety Plan...... 55 7.15. Method Statements and Risk Assessment ...... 55 8 REFERENCES ...... 56

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TABLES

Table Contents Page No. Table 1.1 List of Previous Reports 2 Table 1.2 Project Stakeholders 2 Table 2.1 Site Description and Significant Features 5 Table 2.2 Pre-Remediation Conceptual Site Model 12 Table 3.1 Occurrence of Asbestos Hotspots 22 Table 5.1 Pollution Scenario Assessment 42 Table 6.1 Soil Sampling Frequency 47

FIGURES AND APPENDICES

Figures and Contents Appendices Figure 1. Site Location Plan Figure 2. Proposed Development Layout Figure 3. Plot Layout Plan Figures Figure 4 (4.1 & 4.2) Site Walkover Layout Figure 5. GEMCO Exploratory Hole Location Plan Figure 6 Exploratory Hole Location Plan – ALL Appendix 1 Schedule of Fly-Tipped Materials and Japanese Knotweed Site Assessment Criteria for the Protection of Human Health and Assessment Criteria Appendix 2 for the Protection of Water Supply Infrastructure

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REPORT STRUCTURE

Report Structure Report Section No Brief Description of Content Site description and details of the proposed Section 1: development and a background to the requirement for Introduction this remediation method statement (RMS). Defines stakeholders and basic conditions of the report.

Section 2: Site description, geography, and geological and environmental context and summarises the findings of Site Details and Summary of Findings of previous investigative works and provides detail of the Previous Works contamination encountered. Details the requirements of the proposed remediation Section 3: works and includes the regulatory framework, Detailed Remediation Method Statement specification, and staged approach to the remediation at the site.

Section 4: Provides a background to the legislative framework that governs remediation works and details the options for Environmental Permitting and Regulatory the permitting of certain waste activities that may form Considerations part of the remediation of the site.

Section 5: Provides risk assessment with respect to the proposed foundation method and provides an assessment of Foundation Works Risk Assessment potential future risks. Section 6: Provides a summary of how the remediation works will Verification Plan be validated to ensure compliance with the agreed RMS. Provides details of the Health and safety controls that will Section 7: be adopted at the site to ensure the risks from Health and Safety undertaking the proposed works are mitigated to an acceptable level. Section 8: Provides a list of references used in production of the References report.

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ACRONYMS AND ABBREVIATIONS

Acronyms and Abbreviations Acronym / Abbreviation Definition ACM or PACM Asbestos or potential asbestos containing material ADE Average Daily Exposure ASPT Average Score Per Taxon BOD Biochemical Oxygen Demand BGS British Geological Survey BH Borehole BS British Standard BTEX Benzene, Toluene, Ethyl benzene and Xylenes CAT Cable avoidance tool CIRIA Construction Industry Research and Information Association CLEA Contaminated Land Exposure Assessment CLR Contaminated Land Research reports Defra Department of the Environment, Food and Rural Affairs (formerly the DoE and DETR) DETR Department of the Environment, Transport and the Regions (formerly the DoE and now Defra) DO Dissolved oxygen DoE Department of the Environment (then DETR and later Defra) DQRA Detailed quantitative risk assessment (Tier 2) EA Environment Agency EPH Extractable Petroleum Hydrocarbons EQI Environmental Quality Index EQS Environmental Quality Standards FID Flame ionisation detector GAC Generic assessment criteria GC Gas chromatography GEMCO Green Earth Management Co Ltd GQA General quality assessment GQRA Generic quantitative risk assessment (Tier 1) ha Hectare HCV Health criteria value HHRA Human health risk assessment ICRCL Interdepartmental Committee on the Redevelopment of Contaminated Land ID Index dose LEL Lower explosive limit LOD Limit of detection m Metres mAOD Metres above ordnance datum mbgl Metres below ground level MCERTS Monitoring Certification Scheme MDI Mean daily intake

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Acronyms and Abbreviations Acronym / Abbreviation Definition MTBE Methyl tertiary butyl ether NGR National grid reference NHBC National House Building Council NRA National Rivers Authority (now the Environment Agency) PACM Potentially asbestos containing material PAH Polyaromatic hydrocarbon (a.k.a. polynuclear aromatic hydrocarbon) pH A measure of the acidity or basicity of an aqueous solution. Defined as the negative logarithm of the concentration of hydrogen ions in a substance PID Photo Ionisation Detector PPE Personal Protective Equipment RBCA Risk-based contamination assessment RMS Remediation Method Statement RQO River Quality Objective S4UL Suitable for Use Level SAC Site Assessment Criteria SGV Soil Guideline Value SNIFFER Scotland Northern Ireland Forum for Environmental Research SPT Standard penetration test SSTL Site-specific target level SVOC Semi Volatile Organic Compounds QRA Quantitative risk assessment TDI Tolerable daily intake TDSI Tolerable daily soil intake TP Trial pit TPH Total petroleum hydrocarbon TPHCWG Total petroleum hydrocarbon criteria working group TOX CLR 9 Toxicological Reports UKAS United Kingdom Accreditation Service USEPA United States Environmental Protection Agency UXB Unexploded Bomb VOC (TVOC) Volatile Organic Compounds (Total VOC) WHO World Health Organisation WQS Water Quality Standards WS Window sample

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1 INTRODUCTION

1.1. Project Details

Green Earth Management Company Limited (GEMCO) was commissioned by Jackson Civil Engineering on behalf of Countryside Properties Plc, to produce a detailed remediation method statement (dRMS) for the site at Five Oaks Lane, Chigwell, taking account of the findings of all phases of site investigation including a supplementary investigation carried out by GEMCO between April – May 2015.

Countryside Properties PLC proposed to re-develop the site at Five Oaks Lane, Chigwell, Essex, IG7 4QP for a residential end-use. The site is centred on approximate National Grid Reference 548430, 192150. A site location plan is presented as Figure 1. A proposed development layout is presented as Figure 2.

The site has previously been subject to a number of rounds of Phase I and II site investigations (See Section 1.3) which have been reviewed to inform this geoenvironmental assessment and to identify requirements for further site investigation.

1.2. Objectives

The objectives of the remediation are to:

• To undertake work required to mitigate the identified pollutant linkages to an acceptable level; • Undertake all works in accordance with relevant statutory and local guidance as appropriate; • Provide a completion and validation report for use by the Client in support of the development’s planning application.

1.3. Scope of Work

In order to achieve the objectives of the remediation the scope of works will broadly involve the following;

• Removal of ACM material in development area; • Excavation and treatment of potentially contaminated made ground; • Demolition; • Tree and Vegetation Clearance; • Breakout and excavation of concrete hard standing across site; • Crushing of hard standing on site to produce recycled aggregate; • Excavation and off-site disposal of Japanese knotweed containing soils; • Backfilling resultant voids with chemically and geotechnically suitable materials; • Removal of soil materials (made ground and/or natural soils) to obtain the required finished site levels; • Construction of nominal 600mm clean soil to form a capping layer to underlying contamination in appropriate garden areas as required subsequent cut of site to achieve required levels ; • Creation of ‘clean corridors’ for the construction of buried services at the site (particularly water supply network); and • Verification and validation testing of the works undertaken.

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1.4. Previous Investigations

The site has been previously investigated by GEMCO in 2015, by ST Consult Ltd in 2012, Clarke Bond in 2007 and Hyder Marcus Hodges in 2004. The relevant reports and risk assessments have been forwarded to London Borough of Redbridge in accordance with the requirements of Condition 22 of the planning permission ref 0734/01 issued by London Borough of Redbridge (LBR). Table 1.1 provides a list of the available reports for the site.

Table 1.1 Information Sources No. Report Date 1 GEMCO report Supplementary Phase II Site Investigation and Updated Risk 29th May 2015 Assessment (R.1) 2 ST Consult report ‘Phase II Site Investigation Report. Site: Five Oaks Lane, 6th December Hainault’ prepared for Countryside Four Limited, ref. JN0473 2012 3 ST Consult report ‘Phase I Site Investigation Report. Site: Five Oaks Lane, 10th August Hainault’ prepared for Countryside Properties, ref.DSN0142 2012 4 RPS report ‘Extended Phase I Site Environmental Report, Five Oaks Lane, February 2011 Chigwell’ prepared for Five Oaks Land Limited, ref. JER4521 5 Clarke Bond report ‘Five Oaks Lane, Chigwell, Essex. Geo-Environmental & April 2006 Asbestos Investigation – Stage 1’, prepared for Birse Civils Limited, ref. EL00301/R1 6 Hyder Marcus Hodges report ‘Five Oaks Lane, Chigwell, Essex. Environmental September Assessment’, ref. 52229/R1 2004 7 Topographic Survey supplied by the Client, file ref. F7/S/01, dated 21/12/2005 21st December 2005

1.5. Project Stakeholders

Table 1.2 identifies the various stakeholder that have a direct interest in the works described herein.

Table 1.2 Project Stakeholder Position Responsibility The Developer Countryside Properties PLC (CPPLC) The Principal Contractor Jackson Civil Engineering Ltd (JCE) Demolition Contractor TBC Remediation Sub-Contractor Green Earth Management Co Ltd (GEMCO) Environmental Consultant Green Earth Management Co Ltd (GEMCO) The Local Planning Authority London Borough of Redbridge Waste Regulation & Groundwater Environment Agency Protection

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1.6. Terms of Reference

This Remediation Method Statement (RMS) (herein referred to as the “Report”), has been prepared for Countryside Properties Plc (herein referred to as the “Client”), for the purposes agreed and in general accordance with the terms and conditions set out in proposal reference 514 140919 GEMCO JCE, dated 19th September 2014 and the Agreement between Green Earth Management Co Ltd (the “Consultant”) and the Client. The works were commissioned by Order No. SE0003/001 from JCE to GEMCO dated 7th April 2015.

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2 SITE DETAILS

2.1. Site Setting

2.1.1. Site Location

The site is located along Five Oaks Lane, Chigwell, Essex, IG7 4QP and is centred upon approximate National Grid Reference 548430, 192150. A site location plan is presented as Figure 1. The site comprises a number of former ‘plots’ and the plot layout is presented in Figure 3.

2.1.2. Site Description

GEMCO undertook a site walkover inspection on the 11th February 2015 and intrusive site works between the 8th and the 15th April 2015. The site layout at this time is indicated on Figure 4 and a selection of photographs are included in the GEMCO site investigation report (R.1).

The site occupied an area of around 22.6 Ha and comprised a series of plots of land along Five Oaks Lane. The lane itself was a partially surfaced private road that runs around 1200m to the north-east of the site access from Romford Road (A112). The majority of the site is to the north-west of the lane in a strip around 130m – 160m wide from the lane to the north-west boundary. There are also two areas to the south-east of the lane; one near the south-western end of the site around 300m from the lane to the south-east boundary and the other at the north-eastern end of the site around 140m from the lane to the south-east boundary. There are 2 (no.) plots contained within the overall site boundary that are not part of the site, both near the south-west end on south-east side of the lane (Figure 3 and 4).

The site was formerly divided into numerous long thin plots extending from Five Oaks Lane some of which were effectively within the same usage boundary or have now been effectively combined by demolition and clearance activities as Countryside Properties have acquired and cleared plots.

At the time of the GEMCO site walkover and site works the plot uses included or had recently included domestic properties, numerous sheds and workshops, yard areas, woodland and cleared open space. Activities had included skip yards, timber yards and vehicle breaking and maintenance. There were also large quantities of fly-tipped waste and / or general waste materials arising from former uses.

A brief description of each plot is provided in Table 2.1. Significant features are also highlighted on Figure 4.

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Table 2.1. Site Description and Significant Features Plot Description 1 Five Oaks Lane from the site entrance off Romford Road to around half-way through site. Poorly surfaced and potholed road. 2 Strip of land along north-west side of Five Oaks Lane near south-west end of site, between the lane and a golf driving range off-site to the north-west. The strip was overgrown with bramble and bushes and fenced off (no access). It appeared to be boggy in places. Some fly-tipped waste, including potential asbestos containing cement sheeting was observed (relatively small amounts). 3 Strip of land along the south-east side of Five Oaks Lane near the south-west end of the site. At the time of the site works this was within the fenced boundary of an active development site – cemetery development. 4 Temporary compound area 5 Very overgrown and boggy. Waterlogged / ponding water observed during walkover (very limited access / visibility). Some broken down old sheds and much waste along the rear (south-east) of plots. 6 Area of rough ground with some remains of the floor slab of a former house. Some topographically low areas with ponded water. Some waste toward the back (south-east) of the plot. 7 Front half: caravan, road / track and grassy ‘verge’ leading to parking, small pond on south side (opposite pond in Plot 8) and some sheds with apparently horse related former uses. Some largely domestic type waste materials. Rear half: Yard area, largely cleared. Couple of porta cabin type sheds / offices and articulated lorry trailer. Caravan and small garden area to the rear. Some limited areas of waste materials. 8 Accessed from Plot 7. House and small garden area, pond and 2 x caravans in small plots. 4 storage containers close to house at south-east end with some building materials and ‘domestic’ storage. 9 Effectively part of Plot 10. 10 [Photographs 1 – 3; R.1] Overgrown area and track at front leading to gated area. Beyond the gate there were a number of workshops, appearing to have been predominantly for vehicle maintenance type activities. Much waste in this area associated with workshops including old vehicle parts / chassis etc. Beyond these there was a large yard area with large amounts of waste materials including much striped cable plastic, other plastic materials, many tyres, various metal waste including metal drums, fabric sheets (bedding) including a large smouldering pile of partially burnt sheets and other material. To the rear of this area on the north side there was a small scaffolder’s yard with scaffold storage structure. On the south side of this there as more waste including potentially asbestos containing sheet materials, many tyres, brick and concrete, mattresses, spray cans and some vehicle parts and a number of skips. The far end (south-east) was overgrown and at a slightly lower elevation than the rest of the general surrounding area (within Plot 10). 11 Effectively part of Plots 12 and 13. 12 Plot 12 is the land to the rear of a property (‘Havering’); including a large house and a number of outbuildings) that is not part of the development area. The plot includes a house, a number of caravans and sheds, parking area and some rough ground along a track that runs through the plot to an exit at the rear (south-east). 13 & 14 Plots 13 and 14 are functionally the same area. A number of small houses, caravans and sheds toward the front of plot with a ménage and stables beyond these and paddocks occupying the rear half of the site. There is a small area of trees near the entrance from Five Oaks Lane with domestic waste and an abandoned car. There was also much waste material along the boundary with Plot 15 at just beyond the area of trees and in the sheds along the north-east boundary near the front of the site.

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Table 2.1. Site Description and Significant Features Plot Description 15 [Photograph 30; R.1] Strip of grassed land. Similar level to Plots 13/14 near the front (north-west end) but lower toward the middle / rear of plot. Some brick and concrete and other waste materials in the soils near Five Oaks Lane end. Newt pond constructed at far south-east end. 16 Comprised a thin strip of land between plots 17 – 36 and the golf course to the north-west. Wooded and overgrown with bramble etc. in part. Ditch-line along the rear of other plots evident; wet along south-western section of Plot 16. Some potentially asbestos containing corrugated cement sheeting fragments / part sheets noted – in particular to the rear of Plots 27, 29 and 30. 17 - 22 [Photographs 4 and 5; R.1] Area of ‘cleared land’ around 160m (from Five Oaks Lane to golf course boundary) x 90m wide. Rough vegetation, generally grass and low plants, plus some bushes / immature trees and areas of brambles. There was a small area fenced off toward rear of site identified as a knotweed area. Some areas former hard standing and former building bases. Occasional fly-tipped waste (including settee, tyres, pallet, etc.) Ground level rises toward the north-west with the landform suggesting possible tipping of materials; there is a distinct drop of around at least 1.5m in places from the rear boundary to Plot 16 / the golf course. There was a potential badger set in a soil heap in the middle of the area. Occasional potential asbestos containing materials fragments were noted across the plots. 23 Heavily overgrown area with a number of sheds / workshops behind Plot 23 (The Planets). Generally very limited access / visibility due to overgrown nature. The far end of the site beyond the last sheds had been accessed from Plot 19 and cleared by 15th April (trial pitting works). Asbestos sheeting noted in shed / workshop roofing and storage of asbestos sheets (some broken up) near the rear of the site along boundary with Plot 19. 24 Domestic property (The Planets) with a garden area and garage / workshop and sheds to the rear. 25 Domestic property (Fairlight) at front. Rear part heavily overgrown (poor visibility / access); viewed in part from Plots 23 (rear) and 26. Some waste materials. 26 & 27 [Photographs 6 and 7; R.1] Plots 26 and 27 are functionally the same area. Domestic property (Nil Desperandum) with garden and swimming pool to the front with access to the rear area along the south-west side. Some tipped soils (bank) along the south-west boundary. Yard area with a workshop building (vehicle maintenance / spraying) and a number of sheds, one partially demolished but not cleared to rear, concrete hardstanding along south-west side (Plot 26) and cleared area with exposed soils along north-east site (Plot 27). Small bank of soils with old (dead) knotweed growth visible and potential new knotweed growth (Photograph 7) on north-east boundary of the yard area. Small paddock area and demolished but not cleared stable block between the yard and garden areas. Some potential ACM corrugated cement sheets used in boundary ‘fencing’ with Plot 29 toward the rear of the site. 28 - 33 [Photographs 8 and 9; R.1] Area of cleared or formerly open land around 155m (from lane to the golf course boundary) x 65m wide. Some concrete hard standing near front south corner. Wooded low lying and water logged along the front otherwise. Mature woodland across rear half of site. A large quantity of fly-tipped waste was present across much of the front half and extending into the trees (potentially indicative of systematic tipping). The waste composition was highly variable, including potential construction, industrial / commercial and domestic wastes and including some potential ACM. There were 2 (no.) small areas fenced off near the Plot 27 boundary identified as knotweed areas. There was also some waste, including potential ACM, and two abandoned cars (old) in rear south corner (likely over spill from Plot 27). 34 [Photograph 10;R.1] Domestic property (Trotton) with garden and swimming pool, large grassed area and stable block in the front half of the plot. Yard area and large brick open side warehouse / storage structure to the rear (former Timber Yard). Open areas partially overgrown and with areas

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Table 2.1. Site Description and Significant Features Plot Description of roughly tipped hard-core. Old fuel tank in the east corner of rear area. Landform generally rises toward rear of plot but is not significantly higher than land to the north-west. 35 – 37 [Photographs 11 and 12; R.1] Area of cleared land (excluding Plot 38 which these plots surround & 39 but still has buildings / is fenced off) around 150m (from lane to the golf course boundary) x 110m wide. Largely grassed with some bushes and immature willow. Soft wet ground in places. Hard standing and former building slabs around area. Pile of demolition materials (former house) in Plot 39. Landform generally rises toward rear of plot but is not significantly higher than land to the north- west. Some fly-tipped material including potentially asbestos containing cement sheeting at the front of Plot 39 (possibly tipped over fencing). Occasional potential ACM noted at rear (north-west) and Five Oaks Lane ends of area. 38 [Photographs 31 and 14; R.1] Domestic property (Oakhurst) with sheds and workshops and yard areas to the front and rear. No access during initial site walkover (11/02/2015) but a number of cars (in poor repair) and assorted waste materials including car parts and potential ACM were visible in the front area. During trial pitting work (09/04/2015) the plot had been largely cleared apart from the buildings and small amount of waste materials (metal, wood, plastic, gas cylinders, etc.). 40 - 42 [Photographs 15 and 16; R.1] Area of cleared land (separated from Plots 37 and 39 by a narrow access roadway) around 140m (from lane to the golf course boundary) x 80m wide. There are some former building slabs on the south-west half (Plot 40/41) and a ‘haul road’ formed from crush material and soils on the north-eastern half (Plot 42) leading to the rear of Plot 43. There were a number of piles of similar material along the line of the road; some potential asbestos containing cement materials noted in these heaps. An area to the north-east of the road had been fenced off with newt fencing. Rear area of Plot 40 (south-west of area as whole) at higher elevation than rear of Plot 42; Plot 41 and 42 similar elevations at the front. 43 Front three-quarters of the plot was overgrown, generally low lying and wet and with the remains of a domestic building and some sheds. The rear area of the site was covered by a concrete slab; appearing to be at least in part a workshop / shed base (adjacent to the remains of workshops / warehouse type buildings in Plot 45. 44 Comprised a thin strip of wooded land along the rear of Plots 42, 43, 45 and 48. 45 [Photograph 17; R.1] Front half of plot (adjacent to Five Oaks Lane) comprised a domestic house (Willowvale) and associated garden area and garden sheds. The rear half comprised a concreted / tarmaced yard area, the remains of a burnt out warehouse / workshop type building on a concrete slab and a smaller wooded shed and remains of a further wooden structure. There was a large amount of shattered potentially ACM sheeting largely contained within the area of the burnt out structure. 46 Domestic property (Chyvallan) with garden area and caravan to the rear. 47 Five Oaks Lane from around half-way through site (from Plot 43) to the entrance of Plot 62 near the far end of the lane. Poorly surfaced and potholed road. 48 [Photograph 18 ; R.1] Domestic property (Forest View) and garden stretching around halfway to rear boundary. Overgrown / wooded beyond this (no access / limited visibility). Newt fencing across garden area of Plots 48 and 49 (combined). 49 Domestic property (Sunnyside) and garden stretching around halfway to rear boundary. Overgrown / wooded beyond this (no access / limited visibility). Shed / stable block in overgrown area. Newt fencing across garden area of Plots 48 and 49 (combined). 50 Overgrown / wooded and not practicably accessible. Boarded up at Five Oaks Lane end. 51 [Photograph 19; R.1] Domestic property (Desiree) garden and sheds / workshops which appeared to have been used to manufacture / repair tents. Old swimming pool in garden area which became progressively more wooded toward the rear.

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Table 2.1. Site Description and Significant Features Plot Description 52 Strip of wooded land. Two small buildings (sheds) in very poor repair / part fallen down noted. Large heap of dumped wood chippings near the Five Oaks Lane end. Heavy undergrowth in part (limited visibility / access). 53 Comprised a thin strip of wooded land along the rear of Plots 54 – 60; between these plots and the golf course. Overgrown in parts. 54 & 55 [Photograph 20; R.1] Area of cleared land around 135m (from lane to the golf course boundary) x 100m wide. Some building floor slabs and demo rubble in surface and a concrete surfaces roadway to rear of site. Small soil heap toward rear of area and some metal framework, sheet and glass fragments in the northern corner. Some fly-tipped waste materials along the front of the area. Otherwise generally rough grass with some bushed and immature trees. Some fenced off knotweed areas. 56 [Photographs 22 - 23; R.1] Yard area with porta-cabin office and caravan half way back. Note these were burnt out on the night of 8th April 2015 during the site works period. Some waste materials including old boat, metal drums, tyres, etc.) around site and 2 (no.) skips in poor condition at rear. 57 Overgrown strip of land. No practicable access and limited visibility. Significant quantities of waste visible from Plot 56 (including a car or large part thereof). Large amounts of wood chippings visible along boundary with Plot 58. 58 [Photograph 24; R.1] Domestic property (Woodside) with front yard area and large open area to the rear that appeared to have been extensively tipped with waste and covered over with wood chippings. Ground level up to 5m higher than land to the north-west at the rear of the site but more generally around 3m higher to the rear and around 1m higher nearer the house. Rear area accessed by track along the south-west side of plot. 59 [Photograph 25; R.1] Floor slab / demolition rubble etc. from the removal of a former building near the front of the plot. Tipped waste materials and soils from around halfway back to the rear of the site (possible overspill from Plot 58). 60 Domestic property (The Spinney) and large garden area. Stables, workshops and barns along the south-west side from partway back and at the back of the site. Low circular brick structure (former use not apparent). Storage of potential ACM sheeting along with wood, windows, doors, brick and tiles, pallets and assorted domestic items etc. in the outbuildings. 61 This strip of wooded ground between Plot 62 and the golf course to the north-west. Generally quite overgrown (limited visibility / access) 62 [Photographs 26 and 27; R.1] Domestic House (The Brambles) with large pool house and patio areas, plus garage and other sheds / outbuildings and large garden area. Yard areas around stable block, coach house style shed and metal barn shed. Waste soil earth bund along the north-east boundary. Dead trees along north-east boundary. IBC fuel storage near garage / property entrance. 63 Thin strip between Plot 62 and 66. Effectively the roadway into Plot 62 / 66. 64 [Photograph 29; R.1] Low lying field area. Extensive newt fencing by time of the intrusive site works. 65 [Photograph 29; R.1] Open area. Raised relative to Plot 64 (around 0.5m). Concrete access track from Five Oaks Lane. Large pile of demolition materials. ‘Newt pond’ on north-east side. Extensive newt fencing by time of the intrusive site works. 66 [Photograph 28; R.1] Yard area opposite Plot 62 (associated with Plot 62). Porta-cabin ‘café’ and pond near to entrance on north-west side. Large metal skip / bin in middle of area. Waste soil bund and dead trees along the north-east side.

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2.1.3. Surrounding Area

There was a golf course to the north-west of the bulk of the site beyond a wooded boundary strip and a golf driving range to the north-west Five Oaks Lane near the site entrance.

The land to the north-east was farmland.

The land to the south-east was largely low lying scrub land with grass and bushes. There was occasional tipped or stored building materials and a caravan or two noted in this area.

There were some small plots the south-east of Plots 7 – 14 used for storing building materials or similar and a few items of plant. To the south-west of this area there was some open grass land and an active construction site for a cemetery development.

2.1.4. Topography

Topographically there is a general slope from north-west to south-east across the site and a high point on the north-west boundary close to Plot 40 (around half-way between Romford Road and the north-east end of the site).

The landform continues to rise to the north-west across the golf course. The land to the south-east was generally flatter but with a gentle downward slope away from the site.

2.2. Geology, Hydrogeology and Hydrology

British Geological Survey (BGS) geological records (BGS mapping sheet 257 and BGS online records) (R.1) indicate that the site is underlain by the London Clay (clay, silt and sand) and that there is an area of Claygate Member deposits (clay, silt and sand) off-site, but within around 80m of the site boundary to the north- west associated with the area of higher ground (golf course).

No superficial deposits are identified on site although there is a thin strip of head deposits (clay, silt, sand and gravel) identified just off site to the north of the northern corner apparently associated with a ditch / stream that flows away to the east.

The underlying London Clay bedrock geology is classified as unproductive strata.

The Claygate member deposits to the north-west (and uphill of the site) are classified as a Secondary A Aquifer.

The thin strip of Head deposits off-site to the north are classified as a Secondary (undifferentiated) Aquifer.

The site is not within an Environment Agency designated groundwater Source Protection Zone (SPZ). The closest SPZ is around 3km to the south-west of the site.

No licensed groundwater abstractions are identified within 1km of the site.

The most significant surface water features identified by the walkover were the ditches identified along the north-west, north-east and south-east boundaries.

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Comparison with OS mappings for the area and the Envirocheck report within the ST Consult phase I report (discussed within R.1) data indicate that:

• The ditch along the south-western portion of the north-west boundary drains to the south-west. To where is not clear but it may pick up drainage along Romford Road; • A ditch / drain is also indicated along the north-eastern part of the north-west boundary. This will drain into the ditch along the north-east boundary; • The ditch along the north-east boundary drains to the north before picking up another drain that eventually connects with the River Rom around 700m to the east of the site; and • The ditch along the south-east side of Five Oaks Lane may drain to a ditch indicated around Plots 7 – 15 and then to the south-west and eventually picking up drainage along Romford Road.

Note that site observations at the time of reporting (including relatively conditions in February 2015) indicate that there is generally very limited flow in any of the ditches.

There are small ponds in in Plot 7, 8 and 66. The Plot 7 pond had a visible plastic liner. There were also areas of ponded water in Plots 4 and 5 and to a lesser extent Plot 6 during the February 2015 walkover inspection.

The 1:10,000 OS mapping of the surrounding area shows a pond in the low lying land to the south-east of the site around 200m south-east of Five Oaks Lane and 200m north-east of Plot 15.

There is also a pond around 270m to the east of the north-eastern end of the site. This is at a higher elevation than the site.

The site and surrounding area are not within an EA designated flood risk zone.

2.3. Ground Conditions

The ground conditions encountered are fully described in the GEMCO site investigation report (R.1). The general sequence observed was:

• Made ground and or topsoil: overlying • Clay.

2.3.1. Made Ground

Made ground was encountered across the site to depths of 0.05m – 3.2m bgl; generally up to around 0.6 – 0.6m bgl with areas of deeper fill to around 1.5mbgl and isolated localised areas up to 3.2mbgl.

The residential or formerly residential areas were typically characterised by relatively thin made ground, to around 0.3m – 0.5m bgl comprising silty clayey topsoil or clayey soils with limited anthropogenic content, typically brick etc.

In the vicinity of demolished residential buildings and sheds there was similar thicknesses of made ground but with variable but significant coarse content comprising brick and concrete etc. to cobble and occasionally boulder size with some other waste constituents such as metal and plastic.

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Deeper areas of fill were often associated with the yard areas (e.g. Plot 7 rear and 10, Plots 26 and 27 and plots 62) comprising sandy gravelly with cobbles sized brick, concrete etc. often with road planings, clinker and metal, plastic and other waste constituents. Typically to around 0.7m - 1.0m bgl.

Plots 17 – 22 were characterised by relatively thin made ground associated with demolished buildings and yard areas near the front of the plot group and areas of possible tipped / dumped soils across the rear half of the plot group characterised by generally clayey soils with brick, concrete, etc and some metal and plastic to around 1.0mbgl.

Several areas of more recent tipping activity were noted; the most significant accumulations were within Plots 29 – 33 and Plots 58 and 59.

In Plots 29 – 33 large quantities of waste materials had been dumped on the soil surface mainly across the front (south-east) two-thirds of the plots. The waste materials were highly variable including industrial / commercial and domestic type wastes and possibly soils.

Smaller quantities (but cumulatively significant) of similar waste materials and wood chippings were also noted at a variety of locations across the whole site.

Plot 58 had recently been tipped with waste soils across the back (north-west) half of the plot. The materials largely comprised clayey soils with variable quantities of brick, concrete, metal and plastic, wood and other organic debris etc. capped with a 0.1m – 0.4m thick (typically around 0.2m) layer of wood chippings. The made ground depth ranged from 0.7m – 1.0m at the south-east end of the area to around 3.0m toward the rear of the plot and up to around 5m in a thin strip (‘back wall’ to tipping area) along the rear of the plot before the landform dropped steeply to the natural ground level at the ditch / wooded strip between the site and the golf course.

2.3.2. Clay

Clay generally consistent with the London Clay was encountered underlying the topsoil or made ground at all locations.

2.4. Groundwater

Groundwater was not identified in any of the exploratory hole locations. Small amounts of perched water (infiltrated rainwater) were encountered in some of the locations, typically at the base of the made ground at the interface with the underlying clay strata.

Inflows of perched water will require management during the remediation process.

2.5. Contamination Conditions

2.5.1. Conceptual Site Model – Summary of Linkages of Concern

On the basis of the PAH, Lead and TPH concentrations in the made ground and the presence of ACM around the site, the made ground across the whole site must be considered to have the potential to present a risk to human health where active contaminant linkages are present in the final development layout.

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Active contaminant linkages are considered to be likely where the made ground is present in areas of private green or other soft landscaping;

Where the made ground is present under building footprint or area of permanent hard standing then the linkage will be broken.

2.6. Pre-Remediation Risk Assessment

The pre-remediation conceptual site model and pre-remediation risk assessment is summarised in Table 2.2 below.

Table 2.2 Pre-Remediation Conceptual Site Model and Risk Assessment Source(s) Pathway(s) Receptor(s) Risk1 Comment Future site Moderate Primarily on the basis of lead, PAH and users asbestos (and its physical characteristics) the made ground in its current form is generally likely to be unsuitable for use in the near surface within areas of soft standing in any are of the site (including parkland type open Direct contact space). It is unlikely to present a significant with soils; risk where present under permanent hard ingestion of standing. soil, or soil dust; ingestion Neighbouring Low Assuming suitable (standard) dust of residents / suppression controls are in place during the contaminated site users construction phase the site soils are unlikely vegetable to present a risk to off-site receptors. Post produce; construction the soils are unlikely to present Made inhalation of a significant risk. Ground dust, vapours Construction Low* Assuming standard PPE and working practices or asbestos (lead, and the soils are generally unlikely to present a fibres PAH, TPH maintenance significant risk to construction or and workers maintenance workers. asbestos) * Note that there is the potential for localised contamination hotspots (as yet unidentified) that may require special precautions to be implemented Leaching of Controlled Low The contaminants present are generally contaminants; waters: unlikely to be mobile within the water regime migration to or Surface within surface waters waters Ingress of Future Low The made ground is generally unlikely to vapours into residents, (moderate)** present a significant gas or vapour risk. buildings and workers and ** However use of made ground derived soils confined buildings within building oversites should be limited to spaces; low organic content soils (<1% SOM) and any

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Table 2.2 Pre-Remediation Conceptual Site Model and Risk Assessment Source(s) Pathway(s) Receptor(s) Risk1 Comment inhalation of localised hotspots of deep made ground or vapours soils exhibiting evidence of hydrocarbons (indoor) or should be removed within and around building explosion footprints Contact with The made ground may present a risk to building underground services, particularly water Buried materials / supply services. services, Moderate / services; The specification for buried services must be building Low leaching into confirmed with the relevant supply materials services companies. trenches Metal concentrations in the made ground may have the potential present a risk to Direct contact certain plant species. Not however that the with soils / Ecological made ground is also generally physically Low uptake by receptors unsuitable as a growing medium. plants The landscape consultant should be provided with the site investigation data and a specification for soils for planting agreed. Fly-tipped Wastes and Asbestos Containing Materials All fly-tipped materials and any asbestos containing materials must be removed prior to any significant vegetation clearance or demolition works to ensure these materials are not incorporated into the site soils and to ensure the health and safety of site operatives and neighbouring site users during on-going works. If this is suitably managed these materials do not present an ongoing risk. Demolition Materials The demolition process must be managed to prevent the incorporation of any potentially contaminative materials (particularly ACMs) into the site soils and to ensure the health and safety of site operatives and neighbouring site users during the demolition works. An HSG 264 Demolition and Refurbishment Asbestos Survey (R.2) should be undertaken prior to any demolition works and ACMs removed prior to demolition of the buildings If the demolition works / potentially contaminative materials within the buildings are suitably managed these materials do not present an ongoing risk.

Notes: (1) The risk rating given in the table above is based on classification of consequence and the probability of occurrence; further details are described in Appendix 1.

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3 DETAILED REMEDIATION STRATEGY

3.1. General

The results of the site investigation have confirmed that the level of contamination at the site has the potential to pose a risk to end users and the environment and that there are complete discernible pollutant linkages including a source-pathway-target. Remediation will be required to render the site suitable for the intended residential end use, including areas of public open space and amenity. An appraisal of the remediation options (GEMCO report 514 R01; R.1) concluded that the methods most appropriate to the site are source removal and pathway interruption techniques.

The aim of the remediation is to break the pollutant linkage and thus mitigate the identified risks to acceptable levels. The principal objectives of the remediation are to:

• Limit the direct exposure of future residents and groundworkers to ground contamination to acceptable levels; • Reduce the risk to construction materials from ground contamination to acceptable levels; and • Reduce the risk to future planting in gardens and landscaped areas from ground contamination to acceptable levels.

The remediation is specifically required with respect to the following contamination sources:

• Asbestos containing materials distributed across the site; • Risks to future site residents and users and buried services presented by chemical contamination within the made ground; • Potential hotspots (as yet unidentified) of contaminated or deep organic rich made ground that might present gas / vapour risks to the development; • Physical characteristics of the made ground; and • Fly-tipped waste materials.

The principal objectives of the remediation strategy are to break the identified pollutant linkages and thus mitigate risks to acceptable levels.

The strategy must also account for control of potentially contaminative materials, principally ACM, encountered within the demolition and site clearance works.

3.2. Construction Considerations

3.2.1. Cut and Fill

In order to achieve the required levels for construction it will be necessary to carry out a cut and fill exercise. There is also a need for fill / soil materials to construct the landscaping mounds in the north-east and south- east areas of the site.

A Material Management Plan in accordance with the Development Industry Code of Practice (R.4) should be produced for review and declaration to the EA by a ‘Qualified Person’, to permit the use of site-won soils. Further details are provided in Section 4 below.

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3.2.2. Piling Works for Foundations

It is anticipated that the dwellings will be constructed on a combination of trench fill and piled foundations and a risk assessment with respect to the piling works is presented In Section 5 below. It may be possible to re-use some of the pile arising’s as sub-soil in areas of garden subject to suitable validation testing to ensure compliance with the soil assessment criteria (SAC) for residential end use given in Appendix 2.

3.3. Key Elements of Remediation Strategy

The key elements of the remediation strategy are:

1. Segregation / removal of potential ACM at all stages where encountered (this must be the first element of the remediation and take place before any other site activities); 2. Clearance of fly-tipped wastes and asbestos containing materials (ACM) around the site; 3. Demolition of structures to ground level; 4. Removal of slabs, foundations and other underground structures; 5. Strip and segregate topsoil where present; 6. Removal of LPG Fuel tanks and gas cylinders; 7. Emptying of septic tanks and cesspits; 8. Removal of above ground fuel storage tanks; 9. Management of ponded and perched water; 10. Cut and fill exercise to achieve development platform; 11. Complex sort of waste (fly-tipped) materials; 12. Complex sort of made ground and waste soils; 13. Recovery of hard materials for reprocessing under WRAP protocol for re-use on-site; 14. Recovery of recyclable materials (e.g. metal, plastic, glass); 15. Ex-situ bioremediation treatment of hydrocarbon affected soils; 16. Recovery of soils for re-use; 17. Off-site disposal of unrecoverable waste unsuitable for re-use; 18. Excavation and off-site disposal or treatment of Japanese Knotweed containing soils; 19. Buried services installed to the specification of the relevant statutory undertaker in clean service corridors; 20. Reinstatement of garden public open space soft landscaping areas – provision of suitable soils and capping layers; and 21. Validation inspections, testing and reporting.

The following sections are presented in the order they should be carried out during the remediation works. This is specifically important, to prevent cross contamination, particularly the risk of ACM being entrained into underlying soils, or cross contaminating other materials as a result of contamination of construction plant and machinery.

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3.4. Removal of Visible ACM (Bulk Products)

The site investigation has shown that there are frequent occurrences of Asbestos Containing Material (ACM) at the site with some ACM noted in almost every plot. The vast majority is present as cement bonded asbestos products e.g. corrugated roofing sheets, scattered randomly across the site. These ACM will require removal as far as practically possible, prior to other works being carried out. This is to prevent cross contamination of the areas not affected by tracking and breaking of such products by other construction traffic.

The concentration of asbestos fibres in soil has been taken into account in consideration of the best practical remediation option of the asbestos contaminated soils.

Mechanical processing presents a moderate to high risk of creating airborne dust with a potential for those dust to contain asbestos fibres. It is therefore to be avoided if possible.

Hand picking of the asbestos contaminated soils is the preferred option for removal of bulk products (ACM) and this method reduces the risk of dust generation and liberation of airborne fibres.

The process should broadly involve the following:

1. Setting out area of concern in grid pattern; 2. Systematic walking / picking of visible ACM by trained operatives within a designated grid; 3. ACM will be bagged and transferred to a designated asbestos bin; 4. Rip to loosen an approximate 250mm layer of soil; 5. Systematic walking / picking of visible ACM by trained operatives within designated grid; 6. Excavate to asbestos stockpiling area 250mm layer; and 7. Repeat steps 2 – 6 until potential asbestos contaminated soil is removed (or natural ground encountered).

Appropriate dust suppression and air monitoring will be employed as necessary throughout the process.

Asbestos air monitoring should also be implemented during times when transportation / handling of asbestos containing wastes is being undertaken. The asbestos air monitoring should be carried out by a UKAS accredited laboratory qualified for the analysis of asbestos fibres.

Details of the known areas of ACM at surface are provided in the Demolition Asbestos Survey produced by AEM Asbestos, AEM1052, dated June 2015 (R.2).

In summary, the survey concluded that the majority of ACM are generally bonded products, mainly cement bonded asbestos. There was very limited ACM requiring 14 day notification to the HSE prior to commencement and this was limited to soffits in the property at Plot 13 (Hillview) and AIB identified in in fly-tipped waste materials close to the front (south-east) of Plot 39 (Oakleigh). It is anticipated that the ACM removal works will largely classify as Notifiable Non Licensed Work (NNLW) however the status will be continuously monitored by the Asbestos Surveyor managing the works.

Works must be undertaken by appropriately trained operatives and comply with all current legislation relating to asbestos; i.e. the Control of Asbestos Regulations 2012 (CAR 2012; R.5) and any relevant Health

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and Safety Executive (HSE) guidance including HSE Approved Code of Practice (ACoP) Managing and Working with Asbestos (2013) (R.6).

3.5. Tree and Vegetation Clearance

There is a need to clear trees and vegetation from the site prior to development. All areas must be inspected by the Asbestos Surveyor, prior to access for the contractors is granted. If ACM are present, they must be removed in accordance with Section 3.3 above, before tree and vegetation clearance can commence. It is recommended that a permit to work system is adopted to ensure only inspected areas are accessed by equipment, causing cross contamination or works that may pose a health and safety risk to site personnel.

3.6. Clearance of Fly-Tipped Waste

There are significant quantities of ‘fly-tipped’ wastes at various locations across the site. These wastes will require removal in a phased manner as demolition and site clearance are completed. The wastes are ‘scattered’ at various locations across the site. The worst affected areas are in Plots 28 -33 which will largely be an area of retained woodland in the final development.

A schedule of fly-tipped waste is included as Appendix 1.

The fly-tipped wastes vary in composition with the following broad categories of waste identified:

1. ‘skip waste’ containing a variety of mixed material such as plastics, black bag waste, household items (fridges, kiddies toys, buckets) tyres, paper, cardboard, metal and possible ACM; 2. Construction / demolition waste, comprising soils, concrete, brick, masonry and possible ACM; 3. Wood, made up of waste fence panels and timber; 4. LPG (Propane and Butane) gas cylinders; and 5. ‘Mulch’ - shredded wood waste.

3.6.1. Disposal / Removal of Skip Waste

The largest deposit of this type of waste is in Plots 28-33, but there are a number of other deposits of ‘skip waste’ across the site. There are two options available for dealing with this type of material;

1. Option 1 - complex sort to separate the waste into its component parts to maximise the opportunities to recover recyclable materials such as plastic and metal and tyres: or 2. Option 2 - removal off-site without sorting.

Either of these options is technically acceptable and a cost benefit analysis will be required to determine the most cost effective option. It is almost certainly more economic to sort the wastes into the various waste types prior to disposal off-site.

If complex sort is carried out the operations must be permitted under a mobile treatment licence. Further details regarding complex sorting procedures are provided below and in Section 3.11.1. All operations must comply with the permit requirements including pollution control and emissions monitoring.

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All piles of fly-tipped wastes must be inspected for ACM and visible ACM removed as detailed in Section 3.4 prior to any other sorting being carried out.

An HSG 264 survey has been undertaken and is reported in AEM Ltd report (R.2) prepared for GEMCO. In summary, the survey concluded that the majority of ACM are generally bonded products, mainly cement bonded asbestos. There was very limited ACM requiring 14 day notification to the HSE prior to commencement; however AIB was identified in in fly-tipped waste materials close to the front (south-east) of Plot 39 (Oakleigh).

It is anticipated that the ACM removal works will largely classify as Notifiable Non License Work (NNLW) however the status will be continuously monitored by the Asbestos Surveyor managing the works. Removal of the AIB materials identified in Plot 39 will be Notifiable Works; the 14 day HSE notification will be submitted prior to these works.

Works must be undertaken by appropriately trained operatives and comply with all current legislation relating to asbestos; i.e. the Control of Asbestos Regulations 2012 (CAR 2012; R.5) and any relevant Health and Safety Executive (HSE) guidance including HSE Approved Code of Practice (ACoP) Managing and Working with Asbestos (2013) (R.6).

All tyres should be sorted and kept separate from other wastes for subsequent removal off-site to a suitably licensed recycling / transfer facility.

The disposal of fridges is subject to Waste Electrical and Electronic Equipment (WEEE) and Restriction of Hazardous Substances in electrical and electronic equipment (RoHS) directives. The directive aims to reduce the quantity of waste from electrical and electronic and increase its re-use, recovery and recycling.

All fridges and other WEEE items must be disposed off-site to a facility compliant with the WEEE directive. This may be via a suitably licensed transfer station.

Waste metal should be sorted to a metal bin for recycling at a licensed scrap metal merchant.

All other materials should be disposed off-site to suitably licensed transfer, recovery or recycling facilities.

Non-recyclable surplus wastes should be disposed to a suitably licensed disposal site.

Where possible wood waste separated from the ‘skip waste’ will be separated for recovery potentially as biomass fuel or disposed off-site.

3.6.2. Construction / Demolition Wastes

There are a number of stockpiles of construction / demolition (C&D) wastes scattered across the site, notably in the rear of plot 58 and in plot 59. There is also a large mound of C&D rubble in plot 65/65 (open space area in north-eastern site area. There are also a number of smaller piles scattered across the site.

The C&D waste should be sorted and screened to remove recyclable ‘hard’ materials such as concrete, brick etc. and also to remove deleterious matter such as wood and plastic. Any visible ACM should be removed in accordance with the procedure outlined in Sections 3.4 and 3.6.1 PRIOR to addition to the stockpile of aggregate for processing.

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The recovered hard materials should be included in the re-processing of site won aggregate under the WRAP Quality Protocol for Recycled Aggregates (R.10; also see Section 3.12). All materials produced should be tested in accordance with the WRAP protocol and chemical testing to verify compliance with the site re- use criteria provided in Appendix 2.

Any soils resulting from the screening / sorting operations should be chemically tested to verify compliance with the site re-use criteria provided in Appendix 2. If the soils pass the criteria they would be suitable for use in the permanent works. It is likely that such soils would be suitable for use in public open space, parkland and landscaping areas of the site, subject to validation testing as described above and in accordance with the Verification (Validation) Protocol given in Section 6.

3.6.3. Wood Waste

Where practically possible to do so, all wood waste should be sorted from other material types and kept separate on-site for subsequent disposal or shredding on-site, prior to removal off-site.

3.6.4. LPG (Propane and Butane) Bottles

There are a number of Propane and Butane (LPG) containers across all locations at the site. These canisters pose a risk due to the potential for explosion. These types of cylinders are referred to as ‘orphaned gas cylinders’ and are potentially dangerous. The HSE have issued guidance regarding the safe handling and disposal of these cylinders. All handling and disposal of such cylinders must be in accordance with the HSE guidance (R.7). This guidance also includes fire extinguishers and other gas cylinders such as chlorine.

All orphaned gas cylinders should be carefully transported to a suitable ‘locked’ storage location on site, prior to removal off-site to a suitably licensed facility. The storage locations should be located as far as practically possible from working areas, site compound and any occupied buildings. The storage location should be accessible to vehicles for the safe loading for transport off-site.

There should be no fixed sources of ignition and no smoking will be allowed in the vicinity of the store. The storage location should be away from combustible material such as timber, vegetation etc.

Most LPG & Compressed Gas brands belong to the company named on the cylinder.

With regard to disposal, the UK LPG Association operate a repatriation scheme and can assist in identification of the responsible party and then advise on whether they are a UKLPG or BCGA member. If this is the case they can then provide costs for the collection of the orphaned containers. They can also offered specialist advice in safe disposal routes if the canister is not owned by recognised compressed gas brands e.g. Calor and BOC.

The UKLPA can be contacted at www.uklpg.org.

3.6.5. ‘Mulch’ - shredded wood waste.

There are a number of stockpiles of shredded wood waste around the site and the piles are in various states of decomposition. Occasional fragments of plasterboard and hardcore have been observed in the piles. Due to the presence of these constituents and the potential for ACM (although not yet seen) the state of decomposition these wastes are not suitable for use as biomass fuels. Further due to the presence of

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occasional fragments and pieces of plasterboard, the waste may be considered a high sulphate bearing waste and there is a risk of a reaction with the biodegradable fractions to produce hydrogen sulphide off- gas, which is toxic. The high organic matter content and gassing potential would render the material unsuitable for disposal in landfill facilities. This type of waste is unlikely to meet landfill waste acceptance criteria. It is therefore not recommended that this type of waste is disposed to landfill.

It is recommended that this type of waste is separated from other waste streams and treated on site by mechanical/biological treatment methods (MBT) to produce a Compost Like Output (CLO). Reference should be made to the EA Science report SC030144/SR3 (R.8). The CLO would require chemical testing to ensure compliance with the site re-use criteria given in Appendix 2. Testing of this material should include contaminants associated with timber treatment to ensure suitability for use. Following verification the CLO can be incorporated into site-won topsoil like material as a soil-improver.

The material would be placed into windrows along a non-permeable surface. The windrows are turned on a regular basis to improve oxygen content, distribute heat to regulate temperature and to distribute moisture. The windrow would be turned multiple times during the composting process, which takes on average sixteen weeks. The last part of the process would involve screening the compost to remove contaminants such as plastics and metals, and to also grade the compost for various end uses. Oversized materials are also removed and these can be put back through the whole process until they have composted down sufficiently or removed to other material streams if suitable (e.g. hardcore for crushing).

The quantities of plasterboard are considered to be an extremely low percentage of the overall mass of mulch and whilst there is a potential for the generation of Hydrogen Sulphide H2S, the risk of accumulation in ambient air at levels that would pose a risk are considered to be low. Notwithstanding this, observable plasterboard should be removed from the wood chip material. In addition, during treatment and as a requirement of the MTL, the ambient air will be monitored for gases including, Oxygen, carbon monoxide, VOC and Hydrogen Sulphide (H2S). Details of the monitoring and health and safety trigger levels will be provided in the MTL Deployment Form and Site Working Plan.

The mulch appears to be derived from domestic and industrial wood products and the risk of animal / human and plant pathogens is considered to be low.

The mulch type materials can be sorted and separated from denser material by the use of specialised equipment if required.

The wood chip materials / composted output must not be re-used within building footprints. In addition it should be considered to only suitable for reuse in bulk in areas of public open space area and not buried unless appropriate consideration of the gas generation potential has been made and any required mitigation measures implemented.

3.7. Removal of Hotspots of Asbestos Contaminated Soils

A number of exploratory holes in the various site investigations have encountered ACM present as bulk products or have detected asbestos fibres in soils. The locations are listed in Table 3.1 below. Any other areas identified to contain ACM (or potential ACM) during the excavation of soils during other remediation works will be treated similarly.

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The soils in these locations should be carefully and selectively excavated prior to any further excavation and removal of made ground or reduced level dig. This is required to prevent cross contamination and to minimise the volume of asbestos affected soil.

All works must be undertaken in accordance with current legislation (CAR 2012; R.5) and relevant HSE guidance including ACoP Managing and Working with Asbestos (2013) (R.6). In addition where appropriate reference should also be made to CIRIA document ‘Asbestos in soil and made ground: a guide to understanding and managing risks’ (R.9).

It is anticipated that asbestos related works within the made ground will largely classify as Notifiable Non License Work (NNLW) however the status will be continuously monitored by the Asbestos Surveyor managing the works.

Excavated soils transferred to the sorting / treatment area and segregated from non-asbestos containing soils.

These soils are generally likely (subject to suitable and robust verification testing) to be suitable for re-use only where a minimum cover of 1000mm (1.0m) of suitable non-asbestos soils can be provided. If less than 1.0m of ‘clean cover’ is provided, an anti-penetration layer must be provided. The layer should comprise and high strength geotextile or a 300mm layer of crushed concrete or similar.

Areas of particular note with regard asbestos hotspot removal are the tipped soils in Plots 58 / 59 and the materials in the haul road and heaps along the haul road in Plot 42.

3.7.1. Plot 58 / 59 Fly-Tipped Soils

• Asbestos was detected in 1 (no.) of the 2 (no.) samples (note: the ST consult site investigation appears to have been undertaken before this tipping occurred) taken from the tipped soils in Plot 58 and from 1 (no.) sample of tipped soils toward the rear of Plot 59. It is unlikely that the whole volume of the tipped soils is affected but it is likely that there are other ‘hotspots within the heap; • The known hotspot locations (HS3 and HS19; Table 3.1) should be marked out and the affected soils removed as asbestos affected material; • A watching brief (by an asbestos surveyor) should be maintained during the removal of the tipped soils heap and any soils potentially affected by asbestos removed as asbestos affected material; and • The remainder of the tipped soils should be removed and segregated from other soils then tested prior to treatment.

3.7.2. Plot 42 Haul Road Materials

• ACM and asbestos fibres were detected in a stockpile of material next to the haul road in Plot 42 (GTP551 / HS13). This material was similar to that used in the haul road. All materials in the haul road and in heaps along the haul road should be considered to be potentially affected by asbestos; • The heap sampled (GTP551) should be removed as asbestos containing material; • All other heaps along the haul road should be inspected by an asbestos surveyor and removed as asbestos affected material if any visual evidence of asbestos is identified;

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• The road should be inspected by an asbestos surveyor and removed as asbestos affected material if visual evidence of asbestos is identified; and • Where no visual evidence of asbestos is identified the heap and haul road materials should be removed and segregated then tested prior to treatment as either asbestos affected or non- asbestos affected material.

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Table 3.1. Occurrence of Asbestos in Soils Hotspot Location Depth Plot Asbestos Asbestos Visible Potential ACM in Soils Excavation Protocol Ref. (mbgl) no. Screen1 Conc. (%) (Laboratory Asbestos ID)2 GEMCO Site Investigation HS1 GTP509 0.0 – 0.2 59 +ve < 0.001 Flat sheet / tile fragment (+ve) Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area HS2 GTP512 0.1 – 0.5 56 +ve 1.32 No Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area HS3 GTP517 0.5 – 1.2 58 +ve < 0.001 No (Plot 58 waste soils) Set out location. Strip back wood chippings with care not to incorporate soils. Initially remove soils to around 1.2m below original level / to visually distinct made ground. Extend laterally and vertically on visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS4 GTP521 0.0 – 0.7 38 ND - Flat sheet / tile fragment (+ve) Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS5 GTP525 0.0 – 0.4 7 +ve <0.001 No Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS6 GTP528 0.0 – 0.4 10 +ve < 0.001 Some corrugated and flat sheet Set out location. Surface scrape across area around location to fragments in made ground remove material present at surface on basis visual evidence. (+ve); also frequent cement Then remove soils to base made ground in a 3m x 3m square

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Table 3.1. Occurrence of Asbestos in Soils Hotspot Location Depth Plot Asbestos Asbestos Visible Potential ACM in Soils Excavation Protocol Ref. (mbgl) no. Screen1 Conc. (%) (Laboratory Asbestos ID)2 product noted at ground centred on trial pit location and extend laterally on basis visual surface evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area HS7 GTP531 0.0 – 0.5 10 +ve < 0.001 Corrugated cement sheet Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area HS8 GTP536 0.1 – 0.7 27 +ve < 0.001 No Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area HS9 GTP538 0.25 – 0.45 27 +ve < 0.001 No Set out location. Initially remove soils to around 0.5mbgl / to visually distinct made ground. Extend laterally and vertically on visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area HS10 GTP541 0.0 – 0.4 34 +ve < 0.001 2 sheet fragments (+ve) Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS11 GTP543 0.35 – 0.45 34 - - Layer flat sheet fragments (+ve) Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS12 GTP547 0.4 - 0.8 35 +ve < 0.001 2 corrugated sheet fragments in Set out location. Initially remove soils to base made ground in a near surface 3m x 3m square centred on trial pit location. Extend laterally on

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Table 3.1. Occurrence of Asbestos in Soils Hotspot Location Depth Plot Asbestos Asbestos Visible Potential ACM in Soils Excavation Protocol Ref. (mbgl) no. Screen1 Conc. (%) (Laboratory Asbestos ID)2 basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS13 GTP551 heap 42 +ve < 0.001 Flat and corrugated sheet (Haul Road / Plot 42) (heap) fragments (+ve) Set out location. Remove soil heap in entirety and scrape underlying ground surface. Inspect other heaps along the haul road and the haul road itself for visual evidence of ACM. Remove any heaps or sections of road with visually identified ACM. Remove all other heaps and road materials to a separate heap and validate before either treating as asbestos containing or non-asbestos containing. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS14 GTP556 0.0 – 0.5 55 +ve < 0.001 No Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. ST Consult Site Investigation HS15 TP101 0.1 19 +ve - Cement tile fragments in near Set out location. Initially remove soils to around 0.3mbgl / to surface materials visually distinct made ground. Extend laterally and vertically on visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS16 TP106 0.05 19/20 +ve - Frequent tile fragments Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area.

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Table 3.1. Occurrence of Asbestos in Soils Hotspot Location Depth Plot Asbestos Asbestos Visible Potential ACM in Soils Excavation Protocol Ref. (mbgl) no. Screen1 Conc. (%) (Laboratory Asbestos ID)2 HS17 TP111 0.2 65 +ve - No Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS18 TP112 0.6 65 ND - Possible loose asbestos Note: Visual ID but not detected in sample. Set out location. Excavate trial pit (s) at location and inspect by asbestos surveyor. If ACM confirmed / suspected remove soils on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS19 TP118 0.4 59 +ve - No Note: Deep made ground – possibly represents tipped materials Set out location. Initially remove soils to around 0.7mbgl / to visually distinct made ground or to base of made ground. Extend laterally and vertically on visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS20 TP119 0.0 59 +ve - No Set out location. Initially remove soils to around 0.5mbgl / to visually distinct made ground. Extend laterally and vertically on visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS21 TP121 0.4 55 +ve - Frequent tile fragments Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area.

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Table 3.1. Occurrence of Asbestos in Soils Hotspot Location Depth Plot Asbestos Asbestos Visible Potential ACM in Soils Excavation Protocol Ref. (mbgl) no. Screen1 Conc. (%) (Laboratory Asbestos ID)2 HS22 TP123 0.3 54 ND - Tile fragments Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS23 TP135 2 58 +ve - No Note: Present at depth (1.2 – 2.5mbgl) in ‘pit area’ Plot 58 investigated before tipping Determine depth of occurrence below finished levels. If present at ≥ 1.0m below finished level leave in place but validate soils above (at ≤ 1.0m below finished level). Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS24 TP214 0.1 42 +ve - No After treatment of stockpile and haul road materials in Plot 42 area (See HS13, this table) set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS25 TP29 0.3 34 ND - Cement product fragments Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS26 WS13 0.9 10 +ve - No Determine whether soils affected (made ground at 0.7 – 1.1mbgl) are within 1m of finished ground level. If present at ≥ 1.0m below finished level leave in situ but validate soils above. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area.

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Table 3.1. Occurrence of Asbestos in Soils Hotspot Location Depth Plot Asbestos Asbestos Visible Potential ACM in Soils Excavation Protocol Ref. (mbgl) no. Screen1 Conc. (%) (Laboratory Asbestos ID)2 HS27 WS30 0.3 45 +ve - No Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. HS28 WS65 0.45 14 +ve - No Set out location. Initially remove soils to base made ground in a 3m x 3m square centred on trial pit location. Extend laterally on basis visual evidence. Transport excavated soils to designated asbestos contaminated stockpile in the GEMCO treatment area. Notes: (1) Asbestos Screen: +ve = asbestos identified in sample by lab screes; ND = asbestos not detected (2) Asbestos ID: +ve = asbestos ID undertaken and fragment found to be asbestos (3) National Grid Co-ordinates for the Exploratory Hole Locations are provided in the Schedule of Exploratory Holes presented in GEMCO Report (R.1)

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3.8. Demolition

3.8.1. Demolition of Above Ground Structures

All above ground structures should be demolished by a qualified demolition contractor. Asbestos containing materials identified by the HSG 264 refurbishment and demolition asbestos survey should be removed in accordance with current legislation (i.e. Control of Asbestos Regulations 2012 (CAR 2012; R.5) and any relevant Health and Safety Executive (HSE) guidance including HSE Approved Code of Practice (ACoP) Managing and Working with Asbestos (2013) (R.6)

The HSG 264 survey is reported in AEM Ltd report (R.2) prepared for GEMCO.

In summary, the survey concludes that the majority of materials are generally bonded products, mainly cement bonded asbestos. There are very limited asbestos containing material requiring 14 day notification to the HSE prior to commencement e.g. soffits in Hillview and AIB in fly-tipped waste materials.

It is anticipated that a HSE 14 day notification is submitted on commencement of demolition works on-site.

3.8.2. Breakout of concrete hard standing, excavation of underground obstructions and crushing of site won hard materials

Prior to the removal of contaminated made ground, buildings, hard standing and underground obstructions will be removed to facilitate re-development of the site in accordance with the agreed scheme. The protocol will be to remove the buildings to ground level concrete hard standing and then structures to a depth of nominally 1.50mbgl in areas of gardens and infrastructure (or locally deeper where required). In areas of proposed footprints, any obstructions should be removed to their full depth, where possible, to facilitate the construction of piled foundations in the proposed development.

Suitable materials are to be re-processed on site in accordance with the WRAP Protocol (R.10) and verified suitable for use in the permanent works.

These works will be carried out by the appointed contractor with GEMCO maintaining a watching brief or directly by GEMCO, to ensure that any contamination encountered is dealt with in accordance with the RMS. All of the works will be carried out in accordance with all relevant Health and Safety and Environmental legislation.

Concrete, brick and breeze block should be kept separate during re-processing. All re-processed materials will be tested geotechnically and chemically to ensure compliance with agreed re-use criteria given in Appendix 2.

Excavations to remove obstructions will progress in a phased manner in accordance with a site grid established from the topographic survey prior to commencement of the works. Soils will be stockpiled separately awaiting classification prior to re-use, treatment or disposal.

3.8.3. Emptying and Removal of Above Ground Oil Storage Tanks

A number of above ground fuel storage tanks are located in a number of plots at the site. The tanks are generally assumed to have contaminated kerosene and or diesel.

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Any remaining contents should be removed by vacuum tanker and taken to a suitable disposal facility. The tanks can then be disposed off-site. If required the tanks should be de-gassing prior to cutting or crushing for subsequent removal off-site. The cleaning and gas freeing of tanks should be in accordance with the HSE Guidance Document CS15 (R.11).

3.8.4. Emptying of Septic Tanks and Cesspits

The sewerage network at the site previously comprised domestic septic tanks and cesspits. When encountered these tanks / pits should be emptied to a road-going vacuum tanker by a suitably licensed disposal company. All waste transfer notes should be retained for inclusion in the validation report.

There are also a number of ponds that appear to be contaminated with sewage. These ponds such also be treated as sewage and pumped out and disposed via a road-going vacuum tanker by a suitably licensed disposal company. All waste transfer notes should be retained for inclusion in the validation report.

3.8.5. Perched Water Management

Inflows of perched water are possible during the demolition and removal of buried foundations.

If large accumulations of contaminated water are encountered in the excavations, the fluids will be removed by road-going vacuum tanker, as appropriate. Waste transfer notes and or consignment notes relevant to disposal of water/free product will be included in the validation report.

3.9. Off-Site Disposal / Treatment of Japanese Knotweed (JK)

There are two potential options for dealing with soil affected by knotweed infestation at the site:

1. Off-site disposal; or 2. Cell burial in accordance with EA Code of Practice.

A value engineering exercise is required to determine which of these options provides the most economic and environmentally acceptable solution.

Note that, treatment with herbicide has been ruled out as the Client wishes to develop the site in the short to medium term, there is insufficient time for a long term treatment option (>3years).

The location of the Japanese knotweed is given in the Schedule in Appendix 1.

3.9.1. Off-Site Disposal of Japanese Knotweed

All efforts would be made to minimise the amount of Japanese Knotweed excavated. Excavation should be taken to the full depth of Rhizome, generally estimated at around 3mbgl. Excavation should be extended laterally to 5m beyond the last visible rhizome. The majority of knotweed rhizome is confined to the top 0.5m of soil.

The excavation procedure should be in accordance with the EA Code of Practice (R.12) which is briefly outlined below:

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If off-site disposal is carried out the Japanese Knotweed should first be cut and affected soils then excavated. It is good practice to treat the JK with herbicide approximately 2 weeks prior to off-site disposal. Remove the soil by first scraping off the crowns and surface rhizome and putting to one side.

Crowns and rhizome can be dried and burned (see Section 5.2 of the EA Code) prior to treatment with the remaining soil. If burning is carried out a D7 Exemption [from environmental permitting] should be registered for the site.

At commencement of excavation, crown material in particular is resistant to burning; therefore it is important to regard this material as still potentially infectious.

The next 0.5-1m of soil can then be removed and put aside, and then the remaining soil to a depth of approximately 3m can be excavated.

This material should form the base of a bund (See Section 5.5 of the EA Code), or the top layer of buried material (See Sections 5.4 and 4.1 of Code). This process of excavation can be proportioned to any depth of excavation, rather than adopting the 3m generalised depth. Guidance on the containment and movement of knotweed-infested soil is provided within Sections 2, 6 and 7 of the Code of Practice (R.12).

As a general rule, the area of infestation is 7m horizontally from the nearest growth of Japanese knotweed that can be seen. To determine exactly how far the rhizomes have spread, a series of test pits should be excavated to examine the soils for JK. The area of infestation should clearly be marked out. Any stockpiles should be clearly labelled as JK.

Where practical the use vehicles with caterpillar tracks within the infested area will be avoided and vehicles leaving the area should either be confined to haulage routes protected by root barrier membranes, or be pressure washed in a designated wash-down area. Material from this area should be considered as JK contaminated.

With regard to cutting Japanese knotweed canes, pulled stems often have the highly invasive crown material attached to them, and must be disposed of in the same way as rhizome.

Cut stems are less of a risk, and are safe once they have dried out and turned brown. Cut stems should be left where they can dry out on an appropriate membrane surface, not on soil or grass.

Once the stems have dried to a deep brown colour they are dead. This is not the case with crown or rhizome material.

Japanese knotweed stems can be left on site after cutting if:

• the stem is big enough that it won’t be blown away by wind or traffic; • there is no risk they can get into a watercourse; and • the stem has been neatly cut near its base using a cutter, hook or scythe.

Stems should be cut cleanly so that they don’t create pieces of stem that may spread and regrow. The use of flails will not be permitted.

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The JK soils for disposal should be chemically tested to determine the waste classification for disposal. All efforts should be made to collect a sample of soil that is representative but does not contain rootlets, rhizomes, stem leaves or canes. The laboratory must be made aware of the potential for JK infestation in the sample.

Following confirmation of the waste classification, the JK should be disposed to a suitably licensed facility and the site operator should be made aware that there is living JK in the material.

Disposal will comply with all Duty of Care regulations (R.13) regarding the movement and disposal of such waste. Completed Waste Transfer Notes (WTN) will be kept for all loads and recorded by the contractor and submitted to GEMCO for inclusion in the Validation Report.

All vehicles transporting soils from site should be lined and will be covered prior to leaving site. The wheels on all vehicles leaving the site will be inspected and cleaned as necessary to ensure that no contaminated material leaves site. The public highway in the vicinity of the site entrance will be periodically cleaned using a road sweeper should it become necessary.

3.9.2. Cell Burial Method

Soil containing Japanese Knotweed materials and burnt remains may be buried on a site where is it produced. It is recommended that the material in the cell is treated at least once with a non-persistent herbicide (e.g. glyphosate) to reduce the growth potential of infective material, prior to burial.

It is envisage that the landscaping mounds would be potential locations for a cell burial. The burial should be in accordance with the EA Code briefly outlined below. The JK soils for burial should be chemically tested to determine the concentration of potential contaminants and suitability for disposal in this manner. All efforts should be made to collect a sample of soil that is representative but does not contain rootlets, rhizomes, stem leaves or canes. The laboratory must be made aware of the potential for JK infestation in the sample.

The JK infested soils will be placed within the knoll / mounds in the landscaping areas and covered. Should volumes permit; the material will be placed and then covered with a certified root barrier membrane and covered with a minimum 5m of inert fill as detailed in Section 5.4 Managing Japanese Knotweed on Development Sites (Version 3), Environment Agency, August 2013 (R.12).

If a 5m cover cannot be achieved, the required material will be fully encapsulated and covered with a minimum of 2m knotweed free fill as detailed in section 4.1 of the aforementioned document. All joints will be fusion welded

Material cannot be buried during the active period of herbicides previously applied, spray records and product label will identify this period.

Attention will be given to keeping clean and contaminated soils separate by a clerk of works during the construction of the cell. This will be achieved by ensuring safe passages and adequate storage areas for each fraction. These will be clearly marked, maintained and reviewed regularly to ensure efficiency. After completion or for any other reason, the machines will be cleaned of soils and inspected by the clerk of works before being allowed to leave the restricted area. Upon completion the burial cell will be surveyed and recorded.

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3.10.Recycling of Site Won Topsoil

The findings of the investigation have confirmed that the topsoil site surface material is generally uncontaminated and suitable for use in gardens and public open space areas on-site.

There is potential for localised contamination hotspots however, particularly hydrocarbon contamination associated with former fuel storage or with asbestos. It is noted that the site investigations (R.1) identified 1 topsoil (no.) sample with very high lead concentrations (3868 mg/kg) located in Plot 29 and in soils under the waste materials tipped in this area at the time of reporting; this area will require further investigation / verification after clearance of the waste materials.

During the earthworks phase, the top 150mm of soils will be scraped off following removal of visible ACM as per Section 3.3, segregated on the basis of (visual) soil characteristics and stored in stockpiles located in the GEMCO treatment area. Soils will be tested to determine their suitability for re-use.

Any soils exhibiting visual or olfactory evidence of contamination will be segregated and quarantined in a designated storage area prior to testing.

Any topsoil transported to the soil treatment area will be stockpiled separately from other material types to prevent cross contamination.

If required site-won topsoil may be screened to remove deleterious matter and to further reduce the low levels of contamination.

The material will be processed through a screening plant operated by GEMCO under a mobile treatment license and oversized and waste material removed, as far as practically possible.

Topsoil will be tested in accordance with the Verification (Validation) plan presented in Section 6. The results will be compared with the soil assessment criteria (SAC) provided in Appendix 2. It is anticipated the topsoil will be suitable for use in gardens and areas of public open space. It is noted that certain soil streams may be suitable for use only in less sensitive areas; i.e. some may be suitable for use in public open space but not private gardens.

Suitable composted material (see section 3.6.5) may be added to the topsoil, following appropriate chemical testing to verify compliance with SAC.

3.11.Excavation and Treatment of Potentially Contaminated Made Ground

Contamination in made ground soils has been noted across the site. The conclusions of the site investigation suggest that the made ground at the site is pervasively contaminated and the presence of contamination at levels that are unsuitable for use in residential gardens cannot be ruled out. Hotpot removal is not considered viable due to the random distribution and large site area. The main aim of the remediation will be to ensure that potentially contamination materials are not present in near surface soils in garden / landscape areas. Further details of how garden areas will be re-instated are provided in Section 3.14 below.

During excavation works, monitoring of ambient air with a PID will be undertaken to ensure exposure to VOC’s is minimised and kept to an acceptable level. If VOC concentrations exceed 15ppm, works should be

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suspended and all personnel should leave the area and the vapours allowed to dissipate. Works will re- commence when PID readings have returned to less than 1ppm.

All excavated soils will be transported to a designated soil treatment area operated by GEMCO where they will treated under the auspices of the GEMCO mobile treatment licence (MTL).

Natural ground (if excavated) will be transported to a separate stockpiling and treatment area to potentially contaminated made ground.

The treatment will include complex sorting and potentially ex-Situ bioremediation of any soils contaminated with hydrocarbons.

3.11.1. Complex Sorting Operations

The made ground soils at the site intended for re-use will undergo a complex sorting process which is primarily aimed at removing the biodegradable and geotechnically deleterious materials. The removal of these materials will allow the material to be re-used on site, subject to meeting acceptability criteria (SAC) given in Appendix 2

The complex sorting operations will broadly comprise a screening plant and picking station (if appropriate) where deleterious materials can be removed and transferred to an appropriate container (skip or similar) for removal off site for recycling or disposal at a suitably licensed facility. Materials removed will broadly include the following type of materials:

• Plastic; • Glass; • Wood; • Concrete; • Brick; • Masonry; • Plasterboard; • Textiles; • Metal; and • Cardboard and paper.

Concrete and brick will be retained and re-processed on site for re-use in accordance with the WRAP Quality Protocol – Aggregates from inert waste (R.10). Other materials such as glass, metal and plastic would be disposed to suitable transfer stations for recycling / recovery where possible. Other non-recyclable materials would be disposed off-site.

3.11.2. Ex-Situ Bioremediation

Soil with olfactory or visual evidence of hydrocarbon contamination will be removed and be separated from other soils and stockpiled separately within the GEMCO soil treatment zone. The soils will be tested to determine if the concentration of hydrocarbons exceed the SAC (Appendix 2). Soils will be treated by ex- situ bioremediation to reduce the concentrations to acceptable levels for re-use on site.

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The treatment will general involve an ‘open windrow or biopile’ method with or without the addition of augmentation products. The piles will be periodically turned during the treatment period. On completion of the treatment the soils will be tested to ensure suitability for use within the works.

The treatment would be permitted by the deployment of the GEMCO MTL.

3.11.3. Validation of Treated Soils for Re-Use

Any soils treated will be tested in accordance with the Verification (Validation) plan presented in Section 6 below. The results will be compared with the soil assessment criteria (SAC) provided in Appendix 2. It is anticipated the topsoil will be suitable for use in areas of public open space and potentially gardens subject to rigorous validation testing.

3.12.Recycling of Aggregate

Recyclable aggregate materials (concrete, brick, stone, etc.) will be reprocessed on site in accordance with the WRAP quality protocol for recycled aggregates (R.10).

Recyclable aggregate materials (concrete, brick, stone, etc.) will be recovered from:

• The demolition and site clearance works; these will be transferred to the treatment area; • Recyclable aggregate materials present in the made ground soils or in the fly-tipped wastes will be separated as a consequence of the complex sorting operations.

Suitable material will be re-processed (typically crushed) on site to create aggregates for use in the permanent works, subject to testing for chemical and geotechnical suitability. Operation of the crusher will require a Local Authority Part B environmental permit.

3.13.Backfilling of Excavations

The excavations created by the removal of the sources of contamination and removal of buried obstructions will be backfilled with suitably clean engineering fill which may be generated by the remediation works. Backfilling should be to formation levels agreed with the Client to align with the requirements of the construction works.

3.14.Construction of Buried Services (Particularly Water Supply Network)

Following completion of the cut and fill and remediation it is anticipated that the soils within the service corridors will not pose a risk to buried services, particularly water supply network and special protective materials will not be required for construction of buried services.

In order to ensure that this is the case, the service corridors will be set out on site by the site engineer. Where made ground still exists this will be excavated and replaced with suitably validated clean backfill material. Backfill materials must comply with the screening criteria for the assessment of risk to buried services set out in Appendix 2.

It is advised that this approach is agreed with the appropriate service company and agreed prior to the construction.

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3.15.Construction of Capping Layer in Gardens and Landscaping

On completion areas of private garden and soft standing in public open space areas will be required to meet the following criteria. Validation inspection and testing will be required.

Areas of private garden will require:

• Reinstated gardens must include a minimum of validated suitable subsoil and topsoil to ≥ 0.6m below finished ground level; • If natural soils are encountered at < 0.6m below finished levels excavation may be terminated and the natural soils validated at formation level prior to reinstatement to finished level with validated suitable soils; • If made ground is present below the reinstatement soils at ≥ 0.6m below finished ground level it should be sampled and tested at formation level and if asbestos is present in these soils then the cover increased to 0.75m including an anti-penetration layer (0.15m suitable crush material or similar) or 0.75m and a geotextile membrane between the underlying made ground and the reinstatement soils; and • It is recommended that a minimum of 0.15m suitable validated topsoil is incorporated in the final layer within the cover system.

Areas of soft standing in public open space in close proximity to residential housing will require:

• At least 0.25m of validated suitable soils; • If natural soils are encountered at < 0.25m below finished levels excavation may be terminated and the natural soils validated at formation level prior to reinstatement to finished level with validated suitable soils; • If made ground is present below the reinstatement soils at ≥ 0.25m below finished ground level it should be sampled and tested, and if asbestos is present in these soils then the cover be increased to 0.6m including an anti-penetration layer (0.15m suitable crush material or similar) or 0.6m and a membrane between the underlying made ground and the reinstatement soils; and • It is recommended that the reinstatement soils include a nominal thickness of suitable validated topsoil to the satisfaction of the landscape consultant.

Areas of soft landscaping in park type public open space away from residential housing will require:

• At least 0.25m of validated suitable soils; • If natural soils are encountered at < 0.25m below finished levels excavation may be terminated and the natural soils validated at formation level prior to reinstatement to finished level with validated suitable soils; • Any asbestos containing material must have a ≥ 0.6m of asbestos free cover soils; and • It is recommended that the reinstatement soils include a nominal thickness of suitable validated topsoil to the satisfaction of the landscape consultant.

Validation testing should be on the frequency described in Section 7.6 of this report or as required by LBR.

The soils should conform to the soil assessment criteria (SAC) set out in Appendix 2. In addition soils must be physically suitable for the intended use and be free from deleterious materials such as glass, plastic,

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wood, paper etc. It is recommended that topsoil should also generally comply with the specification for multi-grade topsoil as given in BS 3882:2015 (R.14) or be to the satisfaction of the landscape architect.

3.16.Ground Gas Risks and Hotspot Mitigation Strategy

The site investigation and risk assessment (R.1) did not identify any general ground gas or vapour risks. Specific gas protection measures are not generally required.

However there is the potential for isolated pockets of deeper made ground and /or highly organic soils with gas generation potential and for hotspots of contamination with the potential to generate vapours, particularly hydrocarbon contamination associated with former fuel storage activities.

It is considered that these are best managed through the operation of a discovery strategy (also see Section 3.16) during the remediation and subsequent development works.

Any suspected hotspots or deep pockets of made ground should be inspected and if required samples taken for analysis to inform a risk assessment. If deep made ground, highly organic soils or contamination with the potential to generate ground gases or vapours is identified these should be removed from within or close to building footprints and replaced with suitable (verified) material.

If contamination deemed to warrant an alternative approach (e.g. in-situ treatment or inclusion of gas protection membranes) is identified then further investigation and risk assessment of the area in question will be required to develop the remediation design and additional regulatory approval will be required.

It is noted that the wood chip material present on site must not be allowed to be present within building footprints, or to be used in bulk other than in public open space area and not buried anywhere on site unless the gas generation potential is understood and any appropriate mitigation measures installed.

3.17.Discovery Strategy

Due to the nature of site investigation, it is not always possible to identify all sources of contamination during the investigation works. As such, it is necessary to have plans and procedures for dealing with unknown materials encountered on site during excavation works.

If during the excavation works evidence of previously unknown materials is identified, (either visual or olfactory evidence) the material will be selectively excavated and transported to a designated quarantine area within the GEMCO soil treatment operation.

The material will be sampled and chemically tested and the results of the tests compared with the site re- use criteria set out in Appendix 2. If significant contamination, not previously encountered is identified an alternative remediation strategy will be designed and implemented or the material will be disposed off- site.

Further investigation and sampling will then be required in the area where the quarantined soils were located. The results will then be assessed followed by further risk assessment and the revision of the RMS prior to the continuation of works.

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The results will be notified and reported to the LBR and any changes to the RMS agreed prior to implementation.

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4 ENVIRONMENTAL PERMITTING AND REGULATORY CONSIDERATIONS

4.1. General

The nature of the proposed works is such that some of the materials may classify as waste as described in the Waste Framework Directive (R.15).

The Directive requires member states to ensure that waste is recovered or disposed of without endangering human health and without using processes and methods that could harm the environment.

4.2. Re-Use of Site Derived Materials

Where naturally occurring site won materials are suitable for use, within the criteria provided at Appendix 2 without treatment, and there is a certainty of use, such materials will not be classed as waste.

With regard to the re-use of material at the site, the following regulatory considerations apply:

• Site won naturally occurring materials that are suitable for use without treatment and have certainty of use on site are not waste; • Re-processed site won hard materials including concrete and brick produced following the WRAP protocol for Recycled Aggregate (R.10) are not considered waste; • Re-use of materials on site will be permitted by the Definition of Waste: Development Industry Code of Practise, CoPW Version 2 March 2011, (R.4): and • Any surplus materials arising from the development works will be disposed of off-site to a suitable licensed facility in accordance with the Duty of Care Regulations (R.13) and The Waste Regulations 2011 (R.16).

Soil treatment works will be undertaken in accordance with the Environmental Permitting Regulations (2010). An environmental permit (Mobile Treatment License MTL) will be required to permit the treatment of materials not considered suitable for use.

Operation of a crusher for the purposes of processing site won hard materials to recycled aggregates will require a Local Authority Part B environmental permit.

4.3. Code of Practise on Waste

The re-use of materials on site will be permitted by the Definition of Waste: Development Industry Code of Practise, CoPW Version 2 March 2011, (R.4).

To use the CoPW the project must meet pre-qualification criteria as detailed in the CoPW 2nd Edition March 2011. In order to determine if these criteria are met the MMP and all supporting documentation must be reviewed by a register Qualified Person (QP). On completion of the review and assuming the project meets the criteria the QP will prepare a declaration for submission to the Environment Agency (EA) for registration. The CoPW provides a vehicle to avoid the need to register environmental permits to govern the re-use of site won soils. In order for wastes derived off-site or the re-use of site won material within the permanent works, there must be a certainty of use and the material must be suitable for the intended end use.

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Flow diagram 1 of the CoPW, materials re-use on the site of origin may apply, there may however be a need to import topsoil from a donor site to make up any shortfall in volume produced on-site.

4.3.1. Materials Management Plan

Integral to deployment of the CoPW is the production of a Material Management Plan (MMP) that details the types and amounts of materials, the source of such materials and the proposed end use within the permanent works.

Integral to the implementation of the MMP is the material tracking form that must be completed for all materials re-used or removed during the remediation / construction works.

During implementation GEMCO will oversee maintenance of the records associated with the MMP.

4.4. Imported Materials

If primary materials not classifying as waste are used there is no need for an environmental permit or exemption.

If waste materials up to 1000 tonnes are to be imported to site to create capping or gardens, an exemption (U1) will be required. Alternatively the materials may be imported under a Code of Practise on Waste (See Section 4.3). In the event that greater than 1000 tonnes is required and no suitable donor sites are available, then it may be necessary to apply for a standard rules permit.

There are a number of potentially suitable standard permits e.g. SR2010/No7 and No9. The SR2010/No9 standard permit is the replacement for what was a Paragraph 9 exemption for a site subject to man-made development and the purpose of the activity is to spread waste for reclamation, restoration or improvement of the land. The maximum depth of spreading is 2 metres. SR2010/No7 that is use of waste for construction may be applicable but the waste has to be used as part of construction.

4.5. Off-Site Disposal

Any surplus unsuitable or contaminated materials derived from the works must be correctly classified in accordance with the Hazardous Waste Regulations (R.17) prior to dispatch to a suitable licensed disposal facility. The contractors must satisfy themselves that the disposal site is licensed for the type of waste to be disposed. A register waste carrier must transport all wastes leaving site and copies of the Waste Carriers Licence will be required for inclusion in the validation report. The disposal must comply with the Duty of Care Regulations (R.13) and The Waste Regulations 2011 (R.16). Waste transfer or consignment notes should be retained by the Principal Contractor and copies provided to GEMCO for inclusion in the validation report.

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5 FOUNDATION WORKS RISK ASSESSMENT

Following completion of the remediation work at the site the foundations for the proposed houses will be constructed. Foundations for garages and the construction of roads and infrastructure will largely comprise conventional spread footings or trench excavations as appropriate and will not involve deep penetrative founding methods such as piles or stone columns.

The site is generally underlain by a relatively thin layer of made ground overlying the London Clay. The London Clay is classified as ‘Unproductive Strata; (i.e. a non-aquifer) and the site is not within an Environment Agency designated Source Protection Zone (SPZ).

Any piles would be founded within the London Clay.

5.1. Founding Options

The results of the investigations revealed the following factors to be considered in the foundation design for the proposed development:

• The existence of foundations from former buildings or poorly compacted areas caused by the removal of them; • Potential for soft ground conditions; and • Presence of contamination.

The following options were considered:

• The use of shallow spread foundations is considered an appropriate foundation solution, although may not be appropriate to all areas of the site or to all building types due to the potential for soft ground conditions or localised deep made ground; • CFA piled foundations are considered an appropriate foundation solution for the site. However the type of structures proposed do not require significant load bearing piles and these pile types may be considered excessive for the proposed loads. In addition, this type of piling produces waste soils for disposal, some of which may classify as non-hazardous or hazardous waste for disposal purposes; • Displacement piles are considered an appropriate foundation solution for the ground conditions encountered at the site, subject to agreement from the structural engineer; and • Vibro stone columns (with shallow foundations) are not considered an appropriate foundation solution for the ground conditions encountered at the site.

GEMCO understands, from discussions with the Client, that following consideration of the options the preferred foundation solution for the site is a combination of traditional strip foundations and CFA piled foundations. The foundation risk assessment has therefore considered these foundation solutions.

5.2. Associated Generic Pollution Scenario

Table 5.1 presents a summary of the generic pollution scenarios as described in the Environment Agency Documentation entitled ‘Piling and Penetrative Ground Improvement Methods on Land Affected by Contamination’, reference NC/99/73 (R.18).

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Table 5.1 Pollution Scenario Assessment Pollution Potential Pathway Significance of Justification for assessment Mitigation Measures Adopted Scenario to Receptor Linkage No foundation solution will penetrate the Downward migration – London Clay. The London Clay is a classified as No mitigation required.

creation of preferential ‘Unproductive Strata’ (i.e. a non-aquifer) and Note: ponded water was encountered at a number Pollution pathway - The transport of will act to protect any underlying deep aquifer. Insignificant of locations along the north-west side of Five Oaks Scenario 1 contaminated groundwater Furthermore significant perched water was not Lane. This will be removed prior to any significant down into an aquifer during encountered during the site investigation and works. Significant volumes of perched water were piling no significant leaching potential was identified not encountered elsewhere in the made ground associated with the site soils. No significant soil gas sources have been identified. The underlying London Clay will act Generally no gas protection measures will be Insignificant to prevent any lateral migration from off-site required.

Pollution Migration of ground gas / (Potentially sources. There is however potential for (as yet Where localised contamination hotspots or Scenario 2 volatile gases Significant unidentified) localised hotspots of hydrocarbon deeper pockets of made ground are encountered Locally) or solvent contamination or deeper pockets of these will be removed or treated. Gas membranes organic rich made ground that might form a can also be included if required in affected plots. vapour or gas source. Foundation construction will be undertaken after remediation works have been completed including removal of primary sources of contamination; this should reduce the likelihood of exposure of Direct Contact with The proposed foundation solutions will create Pollution contaminated soils to receptors. Potentially contaminated soil arisings Significant arisings that have the potential to be Scenario 3 contaminated arisings will be taken to the soil been brought to the surface contaminated. treatment area for classification and treatment or disposal as appropriate. Appropriate PPE to be worn by site operatives during site works. Stockpiles to be organised such

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Table 5.1 Pollution Scenario Assessment Pollution Potential Pathway Significance of Justification for assessment Mitigation Measures Adopted Scenario to Receptor Linkage as to prevent run-off of potential leachate to surface waters. In addition the site investigation has not identified a significant risk to controlled waters associated with surface water leaching of the site soils (in-situ). Note that the potentially contaminated soil horizon is generally limited to a relatively thin surface layer. Pile arisings will be largely uncontaminated clay. It is unlikely that the piles will come in contact Direct Contact with with leachate or contamination likely to cause Pollution contaminated soil or degradation of the pile. Localised hotspots of Insignificant No mitigation required (discovery strategy). Scenario 4 Leachate causing contamination with this potential (as yet degradation of pile unidentified) will be removed or treated during the remediation works. The site is underlain by un-productive strata The driving of solid Pollution and use of CFA rather than displacement piles contaminants down into an Insignificant No mitigation required. Scenario 5 means this scenario is not applicable in this aquifer during pile driving instance. Contamination of Groundwater and Pollution subsequent surface waters Insignificant The site is underlain by un-productive strata. No mitigation required. Scenario 6 by stone, cement paste or grout.

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5.3. Refined Risk Assessment in relation to the Proposed Founding Method

The previous section presents a summary of the risk assessment in relation to the adoption of shallow strip or CFA piles as the preferred foundation method for the proposed development. In considering the potentially significant pollution scenarios associated with these solution, two of the generic scenarios have been identified as having the potential to pose unacceptable risk to the sensitive receptors:

• Pollution Scenario 2 (PS2): Migration of ground gas / volatile gases; and • Pollution Scenario 3 (PS3): Direct contact with contaminated soil arisings been brought to the surface.

Nonetheless, the remedial measures adopted to render the site suitable for its intended use, can be extended to provide the suitable levels of risk mitigation that will enable the proposed foundation solutions to be adopted (see Table 5.1 and the following sections).

5.3.1. Pollution Scenario PS2

It is considered that PS2 may have potentially localised significance where, as yet unidentified hotspots of contamination or localised areas of deeper organic rich made ground that could form vapour / ground gas sources through degradation are present. However it is further considered that PS2 may exist (in localised areas) regardless of the foundation method adopted.

The remediation and construction works must allow for the ongoing discovery of such hotspots and then removal or treatment of the vapour / ground gas sources. Gas protection measures may also be considered on a plot by plot basis in these areas. Risk assessment to determine the level of risk and appropriate mitigation measures must be taken as any hotspots are discovered.

5.3.2. Pollution Scenario PS3

CFA piling and traditional strip foundations may both result in potentially contaminated soil arisings.

It is noted however that the potentially contaminated soil horizon is generally limited to a relatively thin layer across the site and that remediation works prior to foundation construction works will have significantly reduced / removed any significant contamination thus limiting the potential for exposure of contaminated soils to site operatives or other receptors. It is noted that the site investigation (R.1) did not identify a significant risk to controlled waters of construction workers associated with the general made ground quality. Further, much of any pile arisings generated will consist of the underlying uncontaminated clay soils.

Measures must be in place to mitigate any risks associated with PS3. However it is noted that the same risks will be associated with much of the required remediation and development works and will exist regardless of the adopted foundation solution.

Mitigation measures will comprise:

• Discovery strategy operated during site works to identify potential contamination hotspots; • Appropriate PPE to be worn by site operatives during all site works;

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• Potentially contaminated arisings will be segregated and taken to the soil treatment area for classification and if appropriate, treatment (refer to Section 3); and • Stockpiles to be organised such as to prevent run-off of potential leachate to surface waters;

5.4. Conclusions

The foundation works risk assessment identified Pollution Scenarios PS2 and PS3 as potentially significant in the context of the site and proposed foundation solutions. It noted however that the potential linkages identified will exist regardless of the foundation solution adopted and be associated with other aspects of the remediation and construction works.

The remediation works designed to address the site conditions generally in the context of the overall development scenario will have a beneficial effect on the contamination levels and is aimed at successful removal of the sources of contamination: i.e. accumulations of asbestos and waste products prior to site clearance and demolition works; removal of potential contamination hotspots and deep pockets of made ground; processing of the mage ground generally and reinstatement with suitable materials. It is therefore considered that the potential risks associated with the foundation solutions will have generally been mitigated to an acceptable level by the remediation works.

Beyond this a discovery strategy must be in place (as it must for all other phases of the remediation and construction works) to account for any potential contamination hotspots discovered during the works at the site (see Section 3).

With regard to PS2, any risks identified associated with ground gas and vapours can be mitigated sufficiently by source removal or treatment (on discovery) or by the inclusion of appropriate gas protection measures in the buildings in the relevant plots (risk assessed at the time on a plot by plot basis).

With regard to PS3 the use of appropriate PPE for ground workers and site operatives is considered to be appropriate and effective at mitigating risk associated with contaminated soils in addition to short duration of exposure.

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6 VERIFICATION (VALIDATION) PLAN

6.1. General

In accordance with CLR 11 (R.3) and in order to ensure the remediation works have been carried out to a satisfactory standard a verification protocol plan is required. The recommended verification protocol is outlined below:

• Site inspection / supervision of works during the main remediation works phase and during subsequent remediation actions undertaken during the construction phase (e.g. garden reinstatements); • Verification testing of site soils left in-situ; • Verification testing of site won soils; • Verification testing of imported soils (if required) and review of chemical test data for any soils to be imported to site prior to acceptance on site; • Verification of depth of cover in garden and soft landscaped areas; • Inspection of waste transfer notes; • MMP tracking records; • Emissions monitoring records; and • Production of a validation report in support of the discharge of planning conditions.

6.2. Site Inspection / Supervision

A GEMCO geoenvironmental consultant will oversee and supervise the remediation works and collect samples to ensure and verify compliance with this RMS and specific method statements.

A qualified asbestos surveyor will supervise the site clearance, excavation and treatment of known asbestos affected soils and any potentially asbestos affected soils encountered during the works.

Appropriate testing of the samples collected must be ensured in a timely manner to assist in determining the materials requirements as either suitable for use, contaminated requiring treatment, or contaminated / untreatable.

Detailed records of the site inspections / works undertaken must be maintained along with a photographic record for inclusion in the completion/validation report and a detailed sample register to assist in the administration of the MMP including provision of chemical test results and assistance in maintaining the tracking records.

6.3. Verification Sampling

As part of the site inspection works samples of in-situ soils, site won soils for re-use and imported soils will be collected as appropriate for testing to verify suitability for use.

The sampling strategy is set out in the following sections and summarised in Table 6.1.

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Table 6.1: Soil Sampling Frequency Soil type Sampling Frequency Site won reprocessed / recovered materials (generally) 1 (no.) sample / 500m3 Site won reprocessed / recovered materials known or suspected to be 1 (no.) sample / 250m3 affected by asbestos Site won topsoil and subsoil materials reprocessed / recovered and 1 (no.) sample / 500m3 stockpiled for re-use on site Topsoil placed in private garden areas 1 (no.) sample / 50m3 Topsoil in landscape areas 1 (no.) sample / 250m3 Subsoil placed in private garden and landscaped area 1 (no.) sample / 250m3 Made ground present below 0.25mbgl in landscaped areas 1 (no.) sample / 250m3

6.3.1. Validation Testing Frequency for Soils (contamination)

Excavated soils reprocessed on site for re-use will generally be tested at a frequency of 1 (no.) sample per 500m3 to determine suitability for re-use.

Soils known or suspected to be affected by asbestos (Section 3.4 & 3.7) prior to reprocessing will be tested to determine suitability for re-use at a frequency agreed with the Environment Agency during the MTL deployment process. It is envisaged however that the testing frequency will be 1 (no.) sample per 250 m3.

Topsoil and subsoil materials reprocessed on-site and destined for use within garden and public soft landscaping areas will initially be tested at a frequency of 1 (no.) sample per 500m3. Treated topsoil and subsoil will be stockpiled on-site prior to re-side. Further testing will be undertaken on the soils as placed at a frequency of:

• 1 (no.) sample per 50m3 of placed topsoil in gardens; • 1 (no.) sample per 250m3 of placed topsoil in landscape areas; and • 1 (no.) sample per 250m3 of placed subsoil in garden and landscape areas.

Made ground soils present below 0.25mbgl in soft landscaping areas will be tested at a frequency of 1 (no.) sample per 250m3.

6.3.2. On-Site VOC Screening

Selected soil samples may be screened for VOCs on-site utilising a photo-ionisation detector (PID). A sample of the soil will be placed in a plastic bag, the bag sealed and the sample / headspace allowed to develop. The VOC concentration in the head space will be measured using the PID. The VOC concentrations recorded will be presented on the geological logs. Note that the VOC concentrations recorded are indicative of the sample VOC content rather than an absolute measurement. Where VOCs are identified further appropriate laboratory testing will be required.

6.3.3. Material / Geotechnical Testing

Recycled aggregates recovered for re-use on site will require testing in line with the WRAP Protocol (R.10).

Other geotechnical testing will be undertaken as required for engineering purposes on any soils re-sued within the permanent works.

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The frequency of testing will comply with the requirements of the WRAP protocol and the Specification for Highways Series 600, Earthworks (R.19) or other appropriate engineering standard.

Further details are provided in Section 6.5 below.

6.4. Chemical Validation Criteria for Soils (Soil Assessment Criteria)

Initially soils for use or re-use in areas of private garden or soft landscaping within residential public open space or park type public open space should conform to the RwHP, POSresi and POSpark Soil Assessment Criteria (SAC) presented in Appendix 2. If required, and appropriate, it may be possible to derive equivalent site specific validations criteria. These would require additional agreement from the relevant regulators (and potentially the building warranty provider).

It is noted that certain soil streams may be suitable for use only in less sensitive areas; e.g. some may be suitable for use in public open space but not private gardens.

Soils should also be physically suitable for use and free from deleterious materials such as glass, plastic, wood, paper etc. In addition it is recommended that topsoil materials should generally conform to BS 3882:2015 R.14) or be to the satisfaction of the landscape consultant.

Recycled aggregates for re-use on site will be reprocessed in accordance with the WRAP Quality Protocol for Recycled Aggregates (R.10) and must be subject to appropriate testing to ensure compliance.

Other geotechnical testing may be required and will be undertaken as appropriate to the designated usage.

6.5. Laboratory Testing

During the remediation works it will be necessary to collect samples of treated materials and in-situ and any imported soils to verify their suitability for use within the framework of this RMS. Samples will be collected for chemical laboratory testing as detailed below:

6.5.1. Chemical Laboratory

Analysis will be required for one or all of the following parameters:

• Metals screen – arsenic, boron (water soluble), cadmium, chromium, chromium (VI), copper, lead, mercury, molybdenum, nickel, selenium, vanadium and zinc; • Organics screen - total petroleum hydrocarbons (TPH) with CWG banding; benzene, toluene, ethylbenzene and xylenes (BTEX); Polyaromatic hydrocarbons (PAH) – USEPA 16 suite; total monohydric phenols; volatile organic compounds (VOC) and semi volatile organic compounds (SVOC); • Inorganics screen - cyanide (total), sulphate (total), sulphide; • Others - pH, organic matter, total organic carbon; and • Asbestos identification and quantification.

Samples of ‘mulch’ should also be tested for the following additional contaminants:

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• TPH, Organo-tin, PCP, Pesticides & VOC

All soils samples will be collected with a clean trowel or shovel. All samples shall be transferred to clean un- used containers of appropriate material. Samples for organic analysis must be collected in amber glass. VOC analysis will be undertaken on samples collected in a separate VOC vial with rubber seal. Each sample should comprise the following containers, or as required by the receiving laboratory:

1. One litre Plastic tub or suitable plastic bag, sealed; 2. One 250ml (minimum) amber glass jar; and 3. One 60ml glass vial for VOC analysis (volatile organic only).

Samples will be stored in a cool-box awaiting dispatch to the laboratory on the same day of collection or the immediate day following.

6.5.2. Material and Geotechnical Testing

Recycled aggregates recovered for re-use on site will require testing in line with the WRAP Protocol (R.10). The following tests will be required on aggregates produced during the works;

• Moisture Content Determination; • Aggregate composition; • Particle shape; • Grading BE EN 933 – 1; • Particle density; and • Los Angeles Resistance to fragmentation.

Other geotechnical testing will be undertaken as required for engineering purposes (e.g. CBR testing) and are likely to include the following:

• Moisture Content Determination; • MCV; • In-Situ and laboratory C.B.R. Tests; • Remoulded single stage triaxial compression tests; • Plasticity indices; • Dry Density / Moisture Content Relationship; • Water soluble Sulphate Content of soil in 2:1 water/soil extract; and • pH value of soil or water.

6.5.3. Quality Control

The laboratories used are accredited laboratory by the United Kingdom Accreditation Service (UKAS). With regard to the chemical testing laboratory at least 50% of individual parameters at the time of testing, were from methods pending accreditation to the Environment Agency Monitoring Certification Scheme (MCERTS) for the range of analyses undertaken as part of this investigation. The MCERTS performance standard for the chemical testing of soil is an application of ISO 17025:2000 specifically for the chemical testing of soil.

514 R02: Issue 1 – Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Page 49 of 56

6.6. Materials Management Plan

GEMCO will produce the MMP and prepare the QP declaration and have considerable previous experience in provision of these services and also have QP services in-house.

During implementation GEMCO will provide assistance in maintenance of the records associated with the MMP. The records should be included in the Validation Report for the site.

6.7. Waste Transfer notes

Where materials are removed from site, copies of the relevant consignment/waste transfer notes should be made available for inclusion in the validation report. The waste transfer notes should be completed in accordance with The Waste (England and Wales) Regulations 2011 (R.15).

6.8. Imported Material Validation Testing

It is recommended that any imported materials are tested and verified suitable for their intended use on site prior to importation. Testing must be undertaken as follows to comply with the Essex Contaminated Land Consortium, Guidance of the importation of soils (R.20).

All laboratory test certificates for all samples tested during the remediation and validation should be retained for inclusion in the completion/validation report.

Topsoil and subsoil materials will require further verification testing as placed as set out in Section 6.3.1 and 6.4.

6.9. Verification Reporting

On completion of the remediation works GEMCO will compile a completion/validation report(s). The reports will possibly be prepared as a series of validation reports as the works are completed. The validation report(s) will summarise the works undertaken and will contain all relevant documentation including results of laboratory testing, soil treatment records and copies of relevant environmental permits.

All reports will be prepared in accordance with current industry standards and guidance, including the Essex Contaminated Land Consortium Guidance (R.20) and the Environment Agency Consultation on the Verification of Remediation of Land Contamination (R.21).

The report contents will be broadly as follows: -

1. Executive Summary; 2. Background; 3. Proposed works; 4. Conceptual Site Model (CSM); 5. Summary of remediation works undertaken; 6. Post remediation risk assessment and refined CSM; 7. Conclusions; 8. Recommendations; and 9. Supporting Documentation.

514 R02: Issue 1 – Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Page 50 of 56

The final verification of the remediation works will not be possible until final construction of the houses and gardens. Therefore, the verification process may be staged.

All reports will be forwarded to the LBR and other appropriate project stakeholders.

514 R02: Issue 1 – Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Page 51 of 56

7 HEALTH AND SAFETY

7.1. General

During the redevelopment, precautions will be taken to minimise exposure of workers and the public to potentially harmful substances. Attention will also be paid to restricting possible off-site nuisance such as dust and odour emissions. These measures will be carried out in accordance with the Health & Safety Executive guidance and construction industry guidance. This document will form part of the Site Construction Health and Safety Plan.

7.2. Site induction and Awareness

All site workers should be briefed on the identified contaminants and Health & Safety (H&S) procedures prior to commencing on site.

7.3. Site Access

The site access and egress during the remediation works and construction will be via Fairfax Drive. Cleaning of all site roads and the public highway will be undertaken as required.

7.4. Site Office and Messing

The site office and will be set up immediately adjacent to the site entrance. Access to the site will be via the Site Office for personnel, or via the plant entrance for vehicles.

The site office will be equipped with suitable messing facilities and toilets.

All visitors will be required to sign in the visitor logbook and will be briefed on arrival on their site visit about the risks associated with contamination on site and precautions they must take. The briefing will include all contractors on site.

No eating or drinking will be allowed on site apart from the site offices and messing facilities. No smoking will be allowed on site.

7.5. Hours of Work

Hours of work will be agreed with LBR but are likely to be as follows:

Monday to Friday 08.00-18:00hrs Saturday 08:00-13:00hrs Sunday No Work

All efforts will be made to minimise disruption to the site neighbours at all times during the works.

514 R02: Issue 1 – Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Page 52 of 56

7.6. Noise

The use of conventional plant and equipment for application of the remediation means the risk posed to the local community is perceived to be similar to any operational construction site, provided site hours are adhered to. The area for the works is reasonably near neighbours and as such that the effects of noise on the surrounding localities is judged to be moderate, all measures to mitigate the effects of noise will be adhered to. Risk to construction workers is controlled by provision of approved ear protection, which will be available for the comfort of site personnel.

All plant will be operated in accordance with manufacturer’s instructions to minimise noise generation and ear protection will be worn in accordance with the machinery operating instructions.

Should complaints be received an investigation would take place into the source of noise nuisance, and, if necessary noise monitoring undertaken. Should the noise continue to exceed acceptable noise levels, suitable abatement measures will be implemented, such as restrictions in operational hours and the use of alternative equipment.

Any complaints received and action taken regarding noise at the site will be recorded and logged in the Site Diary.

Mitigating measures employed on-site to ensure that noise from plant and equipment does not become a problem will include the fitting of silencers on all vehicles used in accordance with manufacturers guidance and if deemed necessary, portable acoustic screens will also be employed on-site.

Noise levels will only be monitored if a problem is identified. If required, monitoring will be undertaken on a daily basis using a hand held noise meter and the results will be recorded and logged in the Site Diary.

7.7. Site Supervision

Where work is to be carried out in areas with contaminated materials present, fencing of sufficient quality to prevent unrestricted and unauthorised access to these areas of the site shall be erected.

All works will be supervised on a part-time basis, by an experienced and suitably qualified environmental consultant(s) familiar with the remediation objectives.

7.8. Welfare and Decontamination Facilities

Washing facilities within the site welfare cabins are to include hot and cold running water, soap and disposable towels. Areas for the preparation and consumption of food will be separate from changing and drying areas.

7.9. Personal Protective Equipment

Suitable protective clothing and personal protective equipment will be provided, based on site-specific hazard risk assessments, which will be detailed in the Health & Safety Plan. Workers will be provided with induction training detailing risks associated with contamination before working on the site and will be made aware of the importance of personal hygiene and washing and changing procedures.

514 R02: Issue 1 – Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Page 53 of 56

The minimum level of PPE considered appropriate at this site is as follows:

• Helmet; • Hi Visibility Clothing; • Overalls; • Safety foot ware; • Gloves and goggles when required ; and • Disposable overalls when required.

7.10. Wheel-Wash Facility and Staging Area

During all earthworks, the wheels on all plant leaving the site will be inspected and cleaned as necessary to ensure that no contaminated material leaves site in vehicles wheels. The public highway near the site entrance will be periodically cleaned using a road sweeper should it become necessary.

7.11. Surface Water Management

The works are unlikely to cause accumulations of surface water on site. However, any accumulations of surface water, which may occur, will be channelled into a sump and collected for disposal off site. The water will not be discharged to public sewer or to groundwater.

7.12. Dust Monitoring

The possible receptors for fugitive dust include surface water features, local dwellings / properties, the surrounding plant life (as dust particles block out the rays of the sun, which will essentially slow down activities such as photosynthesis) and the harmful effects to human health.

From a generic point of view, dust may arise in particular during excavation, screening and loading of soil waste to the lorries. To allow an assessment of these operations the site manager will visually assess dust at least twice a day. Records of visual assessments will be recorded in the Site Diary.

The potential to generate dust & particulates will be dependant generally upon the weather conditions at the time. Risk mitigation measures will include dust suppression by water spray and bowser. When necessary, covering of soils with a suitable membrane will be undertaken.

If the generation of dust was perceived to be a potential risk to off-site receptors, mitigating measures would include ‘damping down’ the surface dust, essentially changing site conditions so that they are no longer optimum conditions for the production of dust. In extreme conditions, site operations would cease until sufficient abatement measures can be implemented.

It is of upmost importance that all lorries transporting waste materials off-site must be adequately sheeted prior to leaving site.

7.13. Odour Control

Odours are possible during the remediation works due to the contamination in host materials or as a result of treatment processes. All efforts will be made to mitigate the associated risk and nuisance.

514 R02: Issue 1 – Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Page 54 of 56

The following mitigating measures will be available on site to control odours generated as a result of the redevelopment works:

• Covering of stockpiles; • Backfilling of odorous excavations; • Cessation of works in extreme cases; and • Installation of perimeter mist system through which odour neutralisation products can be deployed if nuisance becomes persistent.

Odour monitoring by site personnel (on an olfactory basis) will be undertaken on a daily basis and the results will be recorded in the Site Diary. If unacceptable levels of odour arise, site activities will cease until odour suppression measures have been implemented.

7.14. Health and Safety Plan

Prior to remediation, a Construction Phase Health & Safety Plan will be prepared by the Principal Contractor. The site Construction Phase Health and Safety Plan will provide details of the potential health and safety risks that may be applicable during construction. These will include risks associated with potential for contact with hydrocarbons, contaminated soil, water, free products, vapours and the potential for ground gas. The plan will comprise site-specific risk assessments and safety method statements for all tasks undertaken; these will show how the safety of the workforce and the public will be ensured through safe methods of working.

The principles of Health & Safety in relation to contamination are reducing exposure to soils, groundwater and gases through;

• Minimising dust generation; • Minimising handling and direct contact; • Ensuring there is no hand to mouth or hand to eye contact without washing; and • No eating or smoking on site except in predefined areas.

7.15. Method Statements and Risk Assessment

Outline method statements and risk assessments prepared by contractor for the remediation and validation works must be prepared for inclusion in the construction phase health and safety plan.

514 R02: Issue 1 – Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Page 55 of 56

8 REFERENCES

R.1. GEMCO Report, Supplementary Site Investigation and Revised Risk Assessment, Five Oaks Lane, Chigwell, Essex, ref. 514 R01 Issue 1, dated July 2015; R.2. HSG 264 Asbestos Survey Report, Five Oaks Lane, Prepared by AEM Ltd, June 2015; R.3. Department of Environment, Transport and Rural Affairs (DEFRA)/Environment Agency (EA), Model procedures for the Management of Land affected by Contamination. CLR 11, September 2004; R.4. The Definition of Waste – Development Industry Code of Practice, 2nd Edition, CL:AIRE, March 2011; R.5. The Control of Asbestos Regulations 2012, SI 2012 No. 632; R.6. HSE, Managing and working with asbestos. Control of Asbestos Regulations 2012. Approved Code of Practice and guidance, HSE, L143, 2013; R.7. HSE guidance, Orphaned gas cylinders in the waste and recycling industries, HSE, 2013; R.8. Use and application to land of MBT compost like output, EA Science report SC030144/SR3, January 2009; R.9. CIRIA, Asbestos in soil and made ground: a guide to understanding and managing risks, CIRIA C733, 2014; R.10. Waste & Resources Action Programme (WRAP), WRAP Quality Protocol: Aggregates form inert waste – End of waste criteria for the production of aggregates from inert waste, Environment Agency, 2013; R.11. The cleaning and gas freeing of tanks containing flammable residues, HSE Guidance Note CS15, 1985; R.12. The Knotweed Code of Practise – Managing Japanese Knotweed on Development Sites, Environment Agency, 2013; R.13. The Environmental Protection (Duty of Care) Regulations S.I. 1991 No. 2839 and Section 34 of the Environmental Protection Act 1990; R.14. British Standard BS 3882:20015, Specification for Topsoil; R.15. Waste Framework Directive (2008/98/EC); R.16. The Waste (England and Wales) Regulations 2011, SI No. 988; R.17. The Hazardous Waste (England and Wales) Regulations 2005; R.18. Piling and Penetrative Ground Improvement Methods on Land Affected by Contamination: Guidance on Pollution Prevention, National Groundwater & contamination Land Centre Report, NC/99/73, May 2001; R.19. Specification for Highways, Series 600 Earthworks, Highways Agency (SHW600), November 2009; R.20. Land Affected by Contamination, Technical Guidance for Applicants and Developers, Second Edition, Essex Contaminated Land Consortium R.21. Verification of remediation of land contamination, Environment Agency Science Report No NC/00/38/SR.

514 R02: Issue 1 – Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Page 56 of 56

FIGURES

FIGURE 1: SITE LOCATION PLAN FIGURE 2: PROPOSED DEVELOPMENT LAYOUT FIGURE 3: PLOT LAYOUT PLAN FIGURE 4: SITE WALKOVER PLAN FIGURE 5: GEMCO EXPLORATORY HOLE LOCATION PLAN FIGURE 6: ALL EXPLORATORY HOLE LOCATION PLAN

514 R02: Issue 1 - Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Appendix

Approx. site boundary

Map data © OpenStreetMap www.openstreetmap.org

Site: Date: July 2015 Legend: Five Oaks Lane, Chigwell, Essex, IG7 4QP Scale: Not to scale Approximate site location Green Earth Management Company Ltd Drawing: Figure 1 Title: East Gores Farm East Gores Rd Site Location Plan Drawn by: PT Coggeshall, Essex CO6 1RZ

Checked by: DR Client: Tel: 01245 206129 | Fax: 01245 206130 [email protected] | www.gemcoltd.co.uk Countryside Properties Plc Project No: 514 Legend: Site: Date: July 2015

Site Boundary Five Oaks Lane, Chigwell Scale: NTS

Green Earth Management Co Ltd Base image provided by David Jarvis Associates East Gores Farm Drawing No: Figure 2 Ltd. Drawing no. 2276/001, Revision F, Dated Title: East Gores Road April 2014 on behalf of CPPLC Coggeshall, Essex, CO6 1RZ

Proposed Development Layout Drawn by: HS Tel: 01245 206 129 | www.gemcoltd.co.uk

Client: Checked by: DR Countryside Properties Plc Project No: 514 Notes: Figure derived from Countryside Properties, drawing no F00007-SP-014 Dated 06 Jun 2011

Legend: Site: Date: July 2015 Scale: Not to Scale Five Oaks Lane, Chigwell, Essex Green Earth Management Co Ltd Drawing No: Figure 3 East Gores Farm East Gores Road Title: Coggeshall, Essex, CO6 1RZ Drawn by: PT Plot Layout & Numbering Scheme Tel: 01245 206 129 | Fax: 01245 206 130

Checked by: DR Client: [email protected] | www.gemcoltd.co.uk Countryside Properties Plc Project No: 514 Legend:

(Plot 62) Yard area Building demolished / areas cleared since the 2005 survey

Area of extensive waste soil Earth / waste soils ‘bund’ tipping (Plots 58/59) and earth bund (Plot 62/66)

(Plot 58 & 59) Large amount of tipped waste soil across rear half Plot 58 and overspill or tipping

Notes: Underlying layout derived from the 2005 Tree Survey layout (ref. 6). A (Plot 66) Yard area. number of properties were purchased Pond and large metal by Countryside Properties Plc between skip used for burning (Plot 57) Overgrown / inaccessible that time and the final CPO possession waste materials and were demolished / cleared prior to the GEMCO site walkover. There were also some minor building layout chang- GOLF COURSE es with plots not owned by Country- side Properties Plc prior to the CPO (Plot 56) Skip yard (caravan and possession porta-cabin burn out in April)

Site: Demolition (Plots 48 & 49) Overgrown materials Five Oaks Lane, Chigwell, Essex across rear halves heap (approx. location)

Title:

Site Walkover Inspection Layout—North (Plot 45) Main building at back burnt down. Remains present including large amount of Client: shattered ACM sheet Countryside Properties Plc

(Plot 43). Building cleared at back—concrete slab remains. (Plot 65) Field. Large pile demoli- Date: July 2015 tion materials (concrete etc.) Scale: NTS

Drawing No: Figure 4.1

Drawn by: PT (Plot 64) Field Checked by: DR

Project No: 514 (Plot 50) Overgrown / inaccessible

ROUGH LAND / GRAZING Green Earth Management Company Ltd East Gores Farm East Gores Rd Coggeshall, Essex CO6 1RZ Tel: 01245 206 129 | Fax: 01245 206 130

[email protected] | www.gemcoltd.co.uk (Plot 34) Timber yard Legend:

Building demolished / areas New Japanese cleared since the 2005 survey Knotweed growth Extensive tipping of wazste mate- rials: highly variable ’fly-tipped’ wastes

GOLF COURSE Areas within overall site boundary but not within the development (Plots 38) Domestic property and out- buildings. Yard area to rear. Scrapyard type waste and cars in poor condition ACM sheets in ‘fencing’ noted at February 2015 walkover

Stack ACM sheets (Plots 35) Cleared land. Slightly Notes: Underlying layout derived from the 2005 Tree Survey layout (ref. 6). A overgrown number of properties were purchased by Countryside Properties Plc between that time and the final CPO possession and were demolished / cleared prior to the GEMCO site walkover. There were also some minor building layout chang- es with plots not owned by Country- side Properties Plc prior to the CPO possession (Plots 28—33) Extensive waste (Plots 17—22) Cleared land. Appears to have been soils tipped toward rear of tipped across front half of plots area. Slightly overgrown in part. Possible and rear south-west boundary badger set in middle of area. ROUGH LAND / GRAZING

Site:

Five Oaks Lane, Chigwell, Essex

Title: ‘HAVERING’. Not part of the development area Site Walkover Inspection Layout—South

‘THE GABLES’. Not part of the development area Client: GOLF DRIVING RANGE Countryside Properties Plc

Date: July 2015 (Plots 4 & 5) Low lying water Scale: NTS logged land. Overgrown. Derelict sheds near back (Plot 15) Field Drawing No: Figure 4.2

Drawn by: PT

Checked by: DR

Project No: 514

(Plots 7 & 8) Domestic DEVELOPMENT SITE (Cemetery) house, outbuildings / (Plots 13 & 14). Residential to front. Sheds, sheds, 2 caravan s and stables and ménage. Paddocks to the rear ponds Green Earth Management Company Ltd East Gores Farm (Plot 10). Yard area with extensive waste materials. Sheets, plastic East Gores Rd from cable stripping, tyres and vehicle parts. Scaffold Yard to rear Coggeshall, Essex CO6 1RZ (Plot 7) Yard area. Mostly cleared. of area. Workshops in central area. Heavily overgrown at front Tel: 01245 206 129 | Fax: 01245 206 130 Few caravans / cabins remaining [email protected] | www.gemcoltd.co.uk Frequent ACM sheet fragments 6LWH 'ZJ1R /(*(1' )LYH2DNV/DQH&KLJZHOO(VVH[ )LJXUH5 *(0&27ULDO3LW 7LWOH 3URMHFW1R 'ƌĞĞŶĂƌƚŚDĂŶĂŐĞŵĞŶƚŽ>ƚĚ ĂƐƚ'ŽƌĞƐ&Ăƌŵ GEMCO ([SORUDWRU\+ROH/RFDWLRQ3ODQ  ĂƐƚ'ŽƌĞƐZŽĂĚ ŽŐŐĞƐŚĂůů͕ƐƐĞdžKϲϭZ &OLHQW 6FDOH 1RWHV)LJXUHGHULYHGIURP6DPVHWW6XUYH\V (QJLQHHULQJ/LPLWHGVXUYH\ 'UDZQE\37D\ORU GUDZLQJ )LOHUHIVXSSOLHG-XQH dĞů͗ϬϭϮϰϱϮϬϲϭϮϵͮǁǁǁ͘ŐĞŵĐŽůƚĚ͘ĐŽ͘ƵŬ &RXQWU\VLGH3URSHUWLHV3OF As shown 548000E 548100E 548200E 548300E 548400E 548500E 548600E 548700E 548800E

547900E 192800N

192700N

GTP504

GTP502 GTP503 GTP505 GTP501

192600N GTP506

GTP507 GTP508

GTP510

GTP511 GTP517

192500N GTP513 GTP512 GTP516

GTP509 GTP556

GTP514

GTP554 GTP515

GTP555

GTP553

192400N

192300N

GTP551

GTP550

GTP546 GTP545

GTP552 GTP544

192200N

GTP548 GTP547

GTP519

GTP518 GTP542 GTP520 GTP549 GTP541 GTP521 GTP522 GTP543

192100N

GTP536 GTP537 GTP538 GTP563

GTP540

GTP539 GTP562

192000N

GTP561

GTP560

GTP559

191900N

GTP534

GTP535

191800N GTP558 GTP533

GTP557 GTP530

GTP531 GTP529 GTP532 GTP525 GTP527 GTP526

GTP524

191700N

GTP528

GTP523

191600N

  2 Metres 6LWH 'ZJ1R /(*(1' )LYH2DNV/DQH&KLJZHOO(VVH[ )LJXUH6 *(0&27ULDO3LW 7LWOH 3URMHFW1R 3UHYLRXV:LQGRZ6DPSOH 'ƌĞĞŶĂƌƚŚDĂŶĂŐĞŵĞŶƚŽ>ƚĚ ĂƐƚ'ŽƌĞƐ&Ăƌŵ ([SORUDWRU\+ROH/RFDWLRQ3ODQ  3UHYLRXV7ULDO3LW ĂƐƚ'ŽƌĞƐZŽĂĚ ŽŐŐĞƐŚĂůů͕ƐƐĞdžKϲϭZ &OLHQW 6FDOH 1RWHV)LJXUHGHULYHGIURP6DPVHWW6XUYH\V (QJLQHHULQJ/LPLWHGVXUYH\ 'UDZQE\37D\ORU GUDZLQJ )LOHUHIVXSSOLHG-XQH dĞů͗ϬϭϮϰϱϮϬϲϭϮϵͮǁǁǁ͘ŐĞŵĐŽůƚĚ͘ĐŽ͘ƵŬ &RXQWU\VLGH3URSHUWLHV3OF As shown 548000E 548100E 548200E 548300E 548400E 548500E 548600E 548700E 548800E

547900E 192800N

192700N

GTP504

GTP502 GTP503 GTP505 GTP501

192600N GTP506

GTP507 WS42(1) GTP508

TP74(WS)

GTP510 WS41

GTP511 GTP517 TP135 WS40

192500N TP73(WS) GTP513 WS21 GTP512 GTP516 WS39D TP134 WS39E TP117 TP121 WS39C TP133 GTP509 TP110 GTP556 WS22 TP121A GTP514 WS20 WS26 GTP554 GTP515 WS48A TP122 GTP555 WS39B

WS15 TP124 WS39A TP113 GTP553 WS18 TP116 192400N TP114 WS19 TP111 WS36(1) WS25 WS24 TP123 WS16 WS37 TP120 TP115 TP112 WS17 WS23

WS30 WS31A

WS38 WS39 WS31(1) WS32 TP221

WS29

192300N WS34

WS33 WS14 WS28 TP215 TP214 GTP551 WS13 TP210 GTP550 WS27

TP213 GTP546 GTP545 WS12 TP216 TP209 WS30 GTP552 GTP544 TP212 WS11 192200N TP211 TP208 WS29 GTP548 TP207 GTP547

TP217 GTP519 TP206 GTP518 GTP542 TP30(WS) WS28 GTP520 GTP549 GTP541 TP31(WS) GTP521 GTP522 GTP543 TP205 TP204

192100N WS23 TP29(WS)

WS27 WS53(1) GTP536 WS21(1) GTP537 WS22 WS54 GTP538 WS10 WS52 GTP563 TP220

TP131 TP219 GTP540 TP132 WS51 WS09 GTP539 GTP562 TP130 TP218 TP129 192000N TP102 WS08 WS06 TP103 WS35 WS49 GTP561 TP101 WS05 TP104 GTP560 WS48

WS19 WS04 TP105 TP106 TP109

TP107 WS07 GTP559

TP108

191900N WS61

WS02 WS59(1)

GTP534

GTP535 WS14 WS62 WS13

WS15

WS65

WS12 WS01 WS60 TP202 WS63 191800N TP203 TP128 GTP558 WS58 WS31 GTP533

TP126 TP127 TP201 WS57 WS17 GTP557 WS64 GTP530 WS56

TP125 GTP531 GTP529 GTP532 GTP525 WS55 GTP527 WS18 GTP526

GTP524

191700N

GTP528

GTP523

191600N

  2 Metres

APPENDIX 1

SCHEDULE OF FLY-TIPPED MATERIALS AND

JAPANESE KNOTWEED

514 R02: Issue 1 - Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Appendix

Appendix 1. Schedule of Waste Materials Plot Plot Description Materials Present / Notes 1 Existing Five Oaks Lane (road Wood chippings / mulch (approx. 10 loads) area) 2 Strip of land between Five Some fly-tipped material including. asbestos Oaks Lane and Golf Driving sheeting and 4 (no.) tractor tyres Range 5 Boggy area Some derelict old sheds and much waste along the rear (south-east) boundary 6 Cleared area (former house Some waste toward the back (south-east) of the and sheds etc.) Low lying and plot including C&D materials, metal, wood, rough wet in part muck and concrete 7 (front) & 8 Residential house and Caravans, 2 (no.) containers, tyres, domestic and caravans + sheds stables waste, wood chippings 7 (rear) Yard area largely cleared Caravan, luton lorry back with metal and white (possible former Scrap Yard) goods waste, cabin/caravan, caravan base, lorry trailer, IBC (formerly hydraulic oil) 9 & 10 (rear) Yard area, workshops Much waste associated with workshops - vehicle parts etc. Waste in yard area including metal, white goods, C&D wastes, tyres, mattresses, vehicle parts and sheets / bedding. Diesel bowser 13 & 14 Residential house and Car and domestic waste near front. Caravans, gas caravans, sheds, stables, cylinders and metal AST. Domestic waste, TVs, ménage and paddocks metal and IBC in sheds. Tyres. Horse manure 17 - 22 Cleared land Occasional fly-tipped waste including settee, tyres, pallets, etc. Some fly tipped soils along front of area. Appears to be older (now vegetated) tipped soils to rear. Some gas bottles 23 Overgrown. Some sheds. Sheds, metal container, asbestos cement sheeting Land to the rear of The (very limited visibility at time of inspections) Planets (residential house) 24 The Planets: residential house Sheds, workshop wastes, metal AST. Assorted and outbuildings waste including vehicle parts, tyres, wood, C&D waste in overgrown area to rear 25 Fairlight: residential house. Metal AST, fridge, domestic waste, gas cylinders Very overgrown to rear 26 / 27 (front) Nil Desperandum Gas cylinders, shed. Metal sheets over swimming pool 26 / 27 (rear) Workshops and yard area Metal wastes, derelict sheds / workshop, tyres, gas cylinder, general waste 28 - 33 Wooded to rear, open / Extensive tipping of highly variable 'fly-tipped' cleared area at front. waste - including domestic, C&D and commercial wastes. Some workshop waste overspill from Plot 27 and 2 old cars at rear

514 R02: Issue 1 - Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Appendix

Appendix 1. Schedule of Waste Materials Plot Plot Description Materials Present / Notes 34 (front) Trotton: residential house Metal AST. Some domestic waste. 34 (rear) Timber yard Wood, window frames, pre-cast concrete products 35 - 37 Cleared area. Slightly Tipped waste soils / fly-tipped wastes along the overgrown front 38 Oakhurst: Residential house Sheds, metal waste, wood, plastic and gas and workshops / outbuildings cylinder. Tyres. Oil drum. Small pile wood chippings 39 & 40 Cleared area Some distributed waste materials including wood and metal sheeting. Large pile of C&D materials 41 & 42 Cleared area. 'Haul road' Heaps of soil material along haul road (appears through Plot 42 to rear of similar to haul road construction) - included some Plot 43 ACM 43 Cleared area (formerly house Some C&D materials. Metal AST (next to Plot 45 and outbuildings). Slightly front) overgrown 45 (front) Willowvale: residential Burnt out house. Tyres. Metal drum house. 45 (front) Plus access track to rear of Pile of waste in access road to rear of site - site including tyres, white goods, wood, domestic waste, furniture, etc. 45 (rear) Former Timber Yard / Burnt Large amount of shattered asbestos sheet. Burnt out warehouse wood. Metal. Semi derelict sheds. Wood. Gas cylinders and fire extinguishers 46 Chyvallan: residential house Caravan. LPG tank 47 Five Oaks Lane Various wastes tipped along road including wood chippings, tyres, white goods, wood, domestic wastes, etc. 48 Forest View: residential Wood. Garden equipment house. Heavily overgrown to rear 49 Sunnyside: residential house. Domestic waste. Double skinned plastic heating Heavily overgrown to rear oil tank. Garden equipment. Sheds / stable to the rear (in overgrown area) 50 Heavily overgrown Possible derelict buildings 51 Desiree: residential house LPG tank and workshop / outbuildings 52 Overgrown / wooded 2 small semi derelict buildings. Large heap of wood chippings and some other waste materials including 2 fridges and some office furniture fly- tipped at front

514 R02: Issue 1 - Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Appendix

Appendix 1. Schedule of Waste Materials Plot Plot Description Materials Present / Notes 54 / 55 Cleared area Some fly-tipped wastes along the front of area - including wood, plastic, metal, mattresses, domestic refuse. Waste soil heap at rear. Some metal framework (green house) at rear 56 Kestrals: Former skip yard Burnt out caravan and porta-cabin. Metal, wood, some car parts, wooden doors, old metal skips, oil drums, tyres, etc. 57 Overgrown Significant quantities of waste visible from Plot 56 including a car or large part thereof, wood, plastic, metal etc. Large amounts of wood chippings visible along boundary with Plot 58. 58 Woodside: residential house, Large amount of tipped soils across rear of site front yard area and large covered with wood chippings. Brisk etc. rubble in open area to rear entrance to rear access track. Wood chippings on track to rear. Metal AST behind house 59 Cleared area / tipped soils Large volume of tipped soils and other assorted waste materials including wood, straw, plastic, metal, domestic waste and wood chippings 60 The Spinney: residential Storage of potential ACM sheeting along with house and outbuildings, wood, windows, doors, brick and tiles, pallets, gas barns and stables cylinders and assorted domestic items etc. in the outbuildings. Metal AST and LPG tank near house. Mattress and assorted wastes along Plot 59 boundary 62 The Brambles: domestic IBC near house (possibly used for vehicle fuel). house. Yard area with barn / Minor C&D waste. Waste soils bund along east workshop and stable block boundary. 2 gas cylinders 65 Open land Large pile of C&D material (former barn) 66 Yard area (associated with Wooden sleepers and plastic pipe. RoRo skip used Plot 62) for burning waste materials. Waste soils bund along east boundary. Porta-cabin

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APPENDIX 2 SITE ASSESSMENT CRITERIA

514 R02: Issue 1 - Detailed Remediation Method Statement, Five Oaks Lane, Chigwell, Essex July 2015 Appendix

Soil Assessment Criteria for the Assessment of Risk to Human Health 1 1 1 1 Determinand RwHP RwoHP POSresi POSpark Source (mg/kg) (mg/kg) (mg/kg) (mg/kg) Asbestos ND ND ND < 0.001% Metals and Metalloids Arsenic 37 40 79 170 LQM / CIEH (2015) S4UL2 Barium - 1300 - - CL:AIRE (2010)3 Beryllium 1.7 1.7 2.2 63 LQM / CIEH (2015) S4UL2 Boron 290 11000 21000 46000 LQM / CIEH (2015) S4UL2 Cadmium 11 85 120 560 LQM / CIEH (2015) S4UL2 Chromium (III) 910 910 1500 33000 LQM / CIEH (2015) S4UL2 Chromium (VI) 6 6 7.7 220 LQM / CIEH (2015) S4UL2 Copper 2400 7100 12000 44000 LQM / CIEH (2015) S4UL2 Lead 200 310 630 1300 Defra (2014) C4SL4 Mercury - Elemental 1.2 1.2 16 30 (25.8)vap LQM / CIEH (2015) S4UL2 Mercury - Inorganic 40 56 120 240 LQM / CIEH (2015) S4UL2 Mercury - Methyl 11 15 40 68 LQM / CIEH (2015) S4UL2 Nickel 180 180 230 3400 LQM / CIEH (2015) S4UL2 Selenium 250 430 1100 1800 LQM / CIEH (2015) S4UL2 Vanadium 410 1200 2000 5000 LQM / CIEH (2015) S4UL2 Zinc 3700 40000 81000 170000 LQM / CIEH (2015) S4UL2 Phenol – At 1% Soil Organic Matter Phenol 120 440dir (460) 440dir (10000) 440dir (7600) LQM / CIEH (2015) S4UL2

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Soil Assessment Criteria for the Assessment of Risk to Human Health 1 1 1 1 Determinand RwHP RwoHP POSresi POSpark Source (mg/kg) (mg/kg) (mg/kg) (mg/kg) Polyaromatic Hydrocarbons (USEPA 16) – At 1% Soil Organic Matter Naphthalene 2.3 2.3 4900 1200 (76.4)sol LQM / CIEH (2015) S4UL2 Acenaphthylene 170 2900 (86.1)sol 15000 29000 LQM / CIEH (2015) S4UL2 Acenaphthene 210 3000 (57.0)sol 15000 29000 LQM / CIEH (2015) S4UL2 Fluorene 170 2800 (30.9)sol 9900 20000 LQM / CIEH (2015) S4UL2 Phenanthrene 95 1300 (36.0)sol 3100 6200 LQM / CIEH (2015) S4UL2 Anthracene 2400 31000 (1.17)vap 74000 150000 LQM / CIEH (2015) S4UL2 Fluoranthene 280 1500 3100 6300 LQM / CIEH (2015) S4UL2 Pyrene 620 3700 7400 1500 LQM / CIEH (2015) S4UL2 Benzo(a)anthracene 7.2 11 29 49 LQM / CIEH (2015) S4UL2 Chrysene 15 30 57 93 LQM / CIEH (2015) S4UL2 Benzo(b)fluoranthene 2.6 3.9 7.1 13 LQM / CIEH (2015) S4UL2 Benzo(k)fluoranthene 77 110 190 370 LQM / CIEH (2015) S4UL2 Benzo(a)pyrene 2.2 3.2 5.7 11 LQM / CIEH (2015) S4UL2 Indeno(1,2,3-cd)pyrene 27 45 82 150 LQM / CIEH (2015) S4UL2 Di-benzo(a,h)anthracene 0.24 0.31 0.57 1.1 LQM / CIEH (2015) S4UL2 Benzo(ghi)perylene 320 360 640 1400 LQM / CIEH (2015) S4UL2 Coal Tar (BaP surrogate marker) 0.79 1.2 2.2 4.4 LQM / CIEH (2015) S4UL2 Total Petroleum Hydrocarbons (LQM Banding) – At 1% Soil Organic Matter Aliphatic EC5 - EC6 42 42 570000 (304)sol 95000 (304)sol LQM / CIEH (2015) S4UL2 Aliphatic >EC6 - EC8 100 100 600000 150000 (144)sol LQM / CIEH (2015) S4UL2

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Soil Assessment Criteria for the Assessment of Risk to Human Health 1 1 1 1 Determinand RwHP RwoHP POSresi POSpark Source (mg/kg) (mg/kg) (mg/kg) (mg/kg) Aliphatic >EC8 - EC10 27 27 13000 14000 (78)sol LQM / CIEH (2015) S4UL2 Aliphatic >EC10 - EC12 130 (48)vap 130 (48)vap 13000 21000 (48)sol LQM / CIEH (2015) S4UL2 Aliphatic >EC12 - EC16 1100 (24)sol 1100 (24)sol 13000 25000 (24)sol LQM / CIEH (2015) S4UL2 Aliphatic >EC16 - EC35 65000 (8.48)sol 65000 (8.48)sol 250000 450000 LQM / CIEH (2015) S4UL2 Aliphatic >EC35 - EC44 65000 (8.48)sol 65000 (8.48)sol 250000 450000 LQM / CIEH (2015) S4UL2 Aromatic >EC5 - EC7 70 370 56000 76000 (1220)sol LQM / CIEH (2015) S4UL2 Aromatic >EC7 - EC8 130 860 56000 87000 (869)vap LQM / CIEH (2015) S4UL2 Aromatic >EC8 - EC10 34 47 5000 7200 (613)vap LQM / CIEH (2015) S4UL2 Aromatic >EC10 - EC12 74 250 5000 9200 (364)vap LQM / CIEH (2015) S4UL2 Aromatic >EC12 - EC16 140 1800 5100 10000 LQM / CIEH (2015) S4UL2 Aromatic >EC16 - EC21 260 1900 3800 7600 LQM / CIEH (2015) S4UL2 Aromatic >EC21 - EC35 1100 1900 3800 7800 LQM / CIEH (2015) S4UL2 Aromatic >EC35 - EC44 1100 1900 3800 7800 LQM / CIEH (2015) S4UL2 Ali + Aro >EC44 - EC70 1600 1900 3800 7800 LQM / CIEH (2015) S4UL2 BTEX + MTBE – At 1% Soil Organic Matter Benzene 0.087 0.38 72 90 LQM / CIEH (2015) S4UL2 Toluene 130 880 (869)vap 56000 87000 (869)vap LQM / CIEH (2015) S4UL2 Ethylbenzene 47 83 24000 17000 (518)vap LQM / CIEH (2015) S4UL2 o-Xylene 60 88 41000 17000 (478)sol LQM / CIEH (2015) S4UL2 m-xylene 59 82 41000 17000 (625)sol LQM / CIEH (2015) S4UL2 p-xylene 56 79 41000 17000 (576)sol LQM / CIEH (2015) S4UL2

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Soil Assessment Criteria for the Assessment of Risk to Human Health 1 1 1 1 Determinand RwHP RwoHP POSresi POSpark Source (mg/kg) (mg/kg) (mg/kg) (mg/kg) MTBE (Methyl tert-butyl ether) 49 73 - - CL:AIRE (2010)3 VOC – At 1% Soil Organic Matter Vinyl Chloride (Chloroethene) 0.00064 0.00077 3.5 4.8 LQM / CIEH (2015) S4UL2 Chloromethane 0.0083 0.0085 - - CL:AIRE (2010)3 Chloroethane 8.3 8.4 - - CL:AIRE (2010)3 1,1-Dichloroethene 0.23 0.23 - - CL:AIRE (2010)3 trans-1,2-Dichloroethene 0.19 0.19 - - CL:AIRE (2010)3 1,1-Dichloroethane 2.4 2.5 - - CL:AIRE (2010)3 cis-1,2-Dichloroethene 0.11 0.12 - - CL:AIRE (2010)3 trans-1,2-Dichloroethene 0.19 0.19 - - CL:AIRE (2010)3 Chloroform (trichloromethane / TCM) 0.91 1.2 2500 2600 LQM / CIEH (2015) S4UL2 1,1,1-Trichloroethane (1,1,1-TCA) 8.8 9.0 140000 57000 (1425)vap LQM / CIEH (2015) S4UL2 1,2-Dichloroethane (1,2-DCA) 0.0071 0.0092 29 21 LQM / CIEH (2015) S4UL2 1,2-Dichloropropane 0.024 0.024 - - CL:AIRE (2010)3 Trichloroethene (TCE) 0.016 0.017 120 70 LQM / CIEH (2015) S4UL2 Bromodichloromethane 0.016 0.019 1790 - CL:AIRE (2010)3 1,1,2-Trichloroethane 0.6 0.88 - - CL:AIRE (2010)3 Tetrachloroethene (PCE) 0.18 0.18 1400 810 (424)sol LQM / CIEH (2015) S4UL2 Chlorobenzene 0.46 0.46 11000 1300 (675)sol LQM / CIEH (2015) S4UL2 1,1,1,2-Tetrachloroethane (1,1,1,2-PCA) 1.2 1.5 1400 1500 LQM / CIEH (2015) S4UL2 Styrene 8.1 35 - - CL:AIRE (2010)3

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Soil Assessment Criteria for the Assessment of Risk to Human Health 1 1 1 1 Determinand RwHP RwoHP POSresi POSpark Source (mg/kg) (mg/kg) (mg/kg) (mg/kg) Bromoform 2.8 5.2 - - CL:AIRE (2010)3 Isopropylbenzene 11 12 - - CL:AIRE (2010)3 1,1,2,2-Tetrachloroethane (1,1,2,2-PCA) 1.6 3.9 1400 1800 LQM / CIEH (2015) S4UL2 n-Propylbenzene 34 40 - - CL:AIRE (2010)3 Bromobenzene 0.87 0.91 - - CL:AIRE (2010)3 1,2,4-Trimethylbenzene 0.35 0.41 - - CL:AIRE (2010)3 1,3-Dichlorobenzene 0.40 0.44 300 390 LQM / CIEH (2015) S4UL2 1,4-Dichlorobenzene 61 61 17000 36000 (224)vap LQM / CIEH (2015) S4UL2 1,2-Dichlorobenzene 23 24 90000 24000 (571)sol LQM / CIEH (2015) S4UL2 Dichloromethane 0.58 2.1 - - CL:AIRE (2010)3 Notes: sol GAC exceed the solubility saturation limit which is presented in brackets; consideration of the CSM may be required vap GAC exceed the vapour saturation limit which is presented in brackets; consideration of the CSM may be required sat GAC exceed a soil saturation limit (not specified) which is presented in brackets; consideration of the CSM may be required dir GAC is based on tolerable direct contact concentration; long term health protection value presented in brackets (1) RwHP = Residential land use including significant production and consumption of home-grown produce; RwoHP = Residential land use without significant production and consumption of home-grown produce; POSresi = Public open space in close proximity to residential properties (2) Nathanial, C.P. et al. (2015), The LQM/CIEH S4ULs for Human Health Risk Assessment. Land Quality Press, Nottingham. Note that the LQM / CIEM S4ULs update and replace the former LQM / CIEH GAC on the basis of new toxicological and refined modelling data. The S4ULs also cover the Environment Agency SGV substances with the inclusion of updated toxicological and modelling data. (3) CL:AIRE, 'Soil Generic Assessment Criteria for Human Health Risk Assessment', 2010. (4) Defra (2014), ‘SP1010: Development of Category 4 Screening Levels for Assessment of Land Affected by Contamination - Policy Document Companion Document’, Defra, December 2014; CL:AIRE Report 'SP1010 - Development of Category 4 Screening Levels for Assessment of Land Affected by Contamination, Rev 2, September 2014; Defra erratum note, Development of Category 4 Screening Levels for Assessment of Land Affected by Contamination - SP1010, Erratum (December 2014).

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UK Water and Home Builders Federation (HBF) Assessment Criteria for Buried Pipework1 Test Group Pipework Thresholds PE (mg/kg) Barrier Metal Where preliminary risk assessment has identified the possibility for contamination Total VOCs 0.5 Pass Pass Total BTEX + MTBE 0.1 Pass Pass Total SVOC (excluding PAH and substances marked 2 Pass Pass with * below) EC5 – EC10 aliphatic and aromatic hydrocarbons 2 Pass Pass EC10 – EC16 aliphatic and aromatic hydrocarbons 10 Pass Pass EC16 – EC40 aliphatic and aromatic hydrocarbons 500 Pass Pass Phenols* (from SVOC analysis) 2 Pass Pass Cresols and chlorinated phenols* (from SVOC analysis) 2 Pass Pass Only required where a specific need has been identified Ethers* 0.5 Pass Pass Nitrobenzene* 0.5 Pass Pass Ketones* 0.5 Pass Pass Aldehydes* 0.5 Pass Pass Amines* Fail Pass Pass Conductivity, redox and pH (corrosives) Pass Pass See note (2) Notes (1) UK Water and Home Builders Federation, ‘Contaminated Land Assessment Guidance; Protocols published by agreement between UK Water and the Home Builders Federation’, UK Water, January 2014 (2) Thresholds: Wrapped steel corrosive if pH <7 and conductivity > 400µS/cm; Wrapped ductile iron corrosive if pH <5, Eh not neutral and conductivity > 400µS/cm; Copper corrosive id pH <5 or >8 and Eh positive

Essex and Suffolk Water Screening Criteria for Pipe Material Selection1 Contaminant Class Determinant Trigger Value (mg/kg) BTEX Benzene 2 Toluene 10 Ethylbenzene 5 Xylene 2 Phenols Phenol 10 Total Phenols (inc. chlorinated) 10 PAH Naphthalene 50 Anthracene 100 Fluoranthene 100 Benzo(a)pyrene 10 Total PAH 200 Petroleum Hydrocarbons Petrol (PRO or GRO) 10 Diesel (DRO) 800 Mineral Oil 800 Notes (1) Essex and Suffolk Water, New Development (Water), doc ref. ~2115952.coc, dated November 2004 (accessed at http://www.eswater.co.uk/_assets/documents/Contaminated_Land_-_guidance_document.pdf, on the 19th May 2015

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