geo-environmental report geotechnical category 1 proposed ......the relevant british standard...

Geo-environmental Report

Geotechnical Category 1

Proposed New Development Hewett School, Norwich

For Mace Group

Delta Simons Project No. 15-1091.01

Issued: February 2016

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TABLE OF CONTENTS

1.0 INTRODUCTION ............................................................................................... 1 1.1 Authorisation .................................................................................................. 1 1.2 Context & Purpose ......................................................................................... 1 1.3 Scope ............................................................................................................. 2

2.0 INVESTIGATION METHODOLOGY .................................................................. 4 2.1 Desk Study ..................................................................................................... 4 2.2 Conceptual Site Model ................................................................................... 4 2.3 Planning, Setting Out & Services, Presentation .............................................. 5 2.4 Dynamic Sampler Boreholes .......................................................................... 6 2.5 Standpipe Installations ................................................................................... 7 2.6 Dynamic Penetration Tests ............................................................................ 7 2.7 Standard Penetration Tests ............................................................................ 7 2.8 Borehole Falling Head Test ............................................................................ 7 2.9 Monitoring Groundwater & Ground Gas ......................................................... 7 2.10 Chemical Analysis ........................................................................................ 8 2.11 Geotechnical Testing .................................................................................... 8 2.12 Screening Assessment Criteria .................................................................... 8

3.0 RESULTS & INTERPRETATION..................................................................... 10 3.1 Desk Study ................................................................................................... 10 3.2 Fieldworks Interpretation .............................................................................. 12

4.0 LIMITATIONS TO ENVIRONMENTAL ASSESSMENTS ................................. 18

Tables

Table 1 Initial Conceptual Site Model & Risk Assessment

Figures

Figure 1 Site Location Plan Figure 2 Relevant Features Plan Figure 3 Approximate Locations of Boreholes and Penetration Testing

Appendices Appendix I Risk Definitions Appendix II Key to Logs, Field Records & Compliance Certificates Appendix III Monitoring Records Appendix IV Chemical Analysis Appendix V Geotechnical Testing Appendix VI Generic Assessment Criteria

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GEOENVIRONMENTAL REPORT

GEOTECHNICAL CATEGORY 1

PROPOSED NEW DEVELOPMENT

HEWETT SCHOOL, NORWICH

FOR MACE GROUP

DELTA-SIMONS PROJECT NO. 15-1091.01

1.0 INTRODUCTION

1.1 Authorisation

Delta-Simons Environmental Consultants Limited (Delta-Simons) was instructed by

Mace Group (the Client/Engineer) to carry out a site investigation at the Hewett

School, Norwich (hereafter referred to as the “Site”), prior to development if a new

school building. The location of this Site is shown on Figure 1.

1.2 Context & Purpose

There is an existing third party report (EPS, Geo-Environmental Desk Study Report

ref.: UK15.2060, dated December 2015) and UXO report (MACC International

Limited, Project Number 4172) for the Site, which should be read in conjunction with

this Report. A brief review of the EPS report has been included in section 3.1.

At the time of the work, the land concerned had not been identified as requiring

detailed investigation for the purposes of planning associated with either

contaminated or unstable land.

This Report has been undertaken generally in accordance with British Standard BS

5930:1999+A2:2010 Code of practice for site investigations, and is intended as a

Geotechnical Category 1 report in accordance with British Standard BSEN1997-

1:2004 Eurocode 7: Geotechnical Design – Part 1: General rules, or as part of a

preliminary investigation in a Geotechnical Category 2 situation.

The purpose of this investigation was to undertake an initial limited appraisal of the

geo-environmental ground conditions and obtain data on chemical and geotechnical

parameters at the Site for use by the Client considering potential development

planning, design and engineering for construction.

Geoenvironmental Report Proposed New Development at Hewett School, Norwich Delta-Simons Project Number 15-1091.01 Page 2

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This Report has been based on a brief desk study review together with fieldworks

comprising soil sampling and in-situ geotechnical testing. Selected soil samples

were scheduled for laboratory chemical analysis and geotechnical testing. Monitoring

was carried out on the Site for water levels and concentrations of hazardous ground

gas.

The results of the sampling with the relevant laboratory work have been presented in

the Appendices.

The methods of the fieldworks have been described in Section 2.

The interpretation of the results has been presented as a table in Section 3 with desk

study, a conceptual site model (CSM) and initial risk assessment based on the

source-pathway-receptor principle and recommendations for aspects of planning

design and construction.

Foundation design may be undertaken by engineers using methods as described in

Building Regulations/Standards, National House Building Council (NHBC) Standards,

Building Research Establishment (BRE) guidance or if appropriate British Standard

BS 8103-1:1995 Structural design of low-rise buildings — Part 1: Code of practice for

stability, site investigation, foundations and ground floor slabs for housing. Delta-

Simons has also provided further recommendations with respect to the ground

conditions for the assistance of the engineer as designer based on local knowledge

and experience of past projects in the region.

1.3 Scope

The scope of works performed for this Report has been designed in conjunction with

the Client/Engineer and comprised the following:

Review of third-party desk study;

Soil sampling;

In-situ penetration testing;

In-situ permeability testing;

Laboratory testing;

Ground gas monitoring;

Contamination assessment; and

Geotechnical assessment.


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According to BSEN 1997-1, Geotechnical Category 1 (GC1) should only include

small and relatively simple structures for which it is possible to ensure that the

fundamental requirements will be satisfied on the basis of experience and qualitative

geotechnical investigations; - with negligible risk. The designer/engineer is

responsible for checking the Client’s requirements for compliance with the

Eurocodes, and GC1.

This Report may exceed the minimum standards by inclusion of some quantitative

data to support local knowledge and experience in making recommendations.


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2.0 INVESTIGATION METHODOLOGY

2.1 Desk Study

Guidance on desk study practice and interpretation for contaminated land is provided

in British Standard BS10175:2011 Code of practice for investigation of potentially

contaminated sites, and the Environment Agency publication CLR11 “Model

Procedures for the management of land contamination”, plus associated documents

including Department of the Environment Industry Profiles. As the Site has not been

identified as potentially contaminated, the full risk assessment process may not have

been undertaken at this stage.

Desk study practice for geotechnical aspects is described in BS5930:1999+A2:2010

and to a limited extent in British Standard BSEN1997-2:2004 Eurocode 7:

Geotechnical Design – Part 2: Ground investigation and testing. As part of a limited

investigation, the full requirements of a geotechnical desk study may not be

completed.

The desk study report is intended to comply with National House-Building Council

(NHBC) Standards Chapter 4.1 'Land quality - managing ground conditions', and

minimum requirements for local planning authorities (LPAs) for low risk projects.

Basic risk assessment in geotechnics and contamination is provided by the third

party report. A walkover has been conducted by an experienced scientist or

engineer to a standard methodology and where appropriate relevant features have

been marked on Figure 2.

2.2 Conceptual Site Model

A conceptual exposure model represents the relationships between contaminant

sources, pathways and receptors, to support the identification and assessment of

possible pollutant linkages (PPL) - and an assessment of known pollutant linkages,

where identified from existing information.

Where PPLs are identified, a preliminary risk assessment is carried out to assess the

likelihood that each possible linkage exists and to decide whether these pose

potentially unacceptable risks to identified receptors and require further assessment.

Where this linkage is of a form that subsequently leads to land being identified as


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‘contaminated land’ under the terms of Part 2A of the Environmental Protection Act

1990, the linkage is termed a significant pollutant linkage.

At the preliminary risk assessment stage, which is usually based upon desk top

information, the decision on whether a PPL poses a potentially unacceptable risk is

based upon professional judgement. The significance of the PPL will also be

determined dependant on the context of the land use and the purpose of the

assessment.

Assessing risks from land contamination underpins the “suitable for use” approach

adopted for Part 2A of the Environmental Protection Act 1990 regulatory regime and

the National Planning Policy Framework (NPPF), March 2012.

Based on the information obtained from this assessment, a preliminary risk

assessment using the source-pathway-receptor approach has been formulated,

which identifies PPLs at the Site in the context of the proposed end-use.

A CSM and preliminary risk assessment is presented at the end of Section 3 and it

takes into account the relevant findings of the field and laboratory outcomes.

Appendix I contains risk definitions.

2.3 Planning, Setting Out & Services, Presentation

Unless otherwise stated, the investigation has been planned on a scope of works

agreed with the Client which is typically based on multiples of one day on-Site with

various drilling and sampling equipment, or a measured amount of drilling and

testing.

Clients are requested to provide all service plans in original form from suppliers so a

services risk assessment can be undertaken as part of a formal Site-specific Health

and Safety Plan. The services risk assessment is based on guidance provided in

HSG47 Avoiding danger from underground services.

Exploratory hole and subsequent sample locations were selected to provide suitable

coverage of the Site, having regard for the likely presence of services and any other

Site-specific constraints such as existing structures and finishes. Where applicable,

suspected emissions locations, or geology variations may have been targeted.


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Prior to any excavation, specialist utilities and unexploded ordnance clearance was

completed at the locations of the intrusive holes. In addition, a cable detector was

used at sampling positions to avoid electric cables and hand tools were used as

though services were located close by.

The locations of the investigations are shown on Figure 3 and the field records are

provided in Appendix II.

2.4 Dynamic Sampler Boreholes

Dynamic sampler borehole systems are not explicitly described in Eurocodes, or in

the relevant British Standard BSENISO 22475-1:2006 Geotechnical investigation and

testing – Sampling methods and groundwater measurements – Part 1: Technical

principles for execution.

The dynamic sampler system comprises a series of varying diameter metal tubes of

1 m or 2 m length, which allows a liner to be inserted. The tubes are driven into the

ground using a percussive weight falling through a standard drop onto an anvil

attached to solid rods, and withdrawn by use of a hydraulic jack. The soil is pushed

into the tube/liner during the driving, and samples are recovered from the tube once it

has been split for description. Alternatively, liners are omitted and the metal tubes

have slots or windows cut into the sides where samples can be taken directly by

hand.

The liner method potentially offers a lower degree of sample disturbance.

The system can achieve typical depths of around 3 m to 5 m in favourable soil

conditions. The system is limited by coarse gravel or other large fragments, and also

in wet sands where the hole collapses. Some casing systems exist.

The details of the ground conditions encountered are presented on the relevant field

record sheets, which also detail the type and depths of samples taken and the results

of any in-situ tests. Other relevant information may also be recorded including

groundwater levels and details of any standpipe installations.


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2.5 Standpipe Installations

Three of the dynamic sampler boreholes have been fitted with a gas/water monitoring

standpipe of 50 mm internal diameter UPVC slotted and plain casing to the required

depth as appropriate, capped by a gas tap bung and cover generally in accordance

with BSENISO 22475-1:2006 for an open standpipe. The locations of the monitoring

installations are shown on Figure 3.

2.6 Dynamic Penetration Tests

Dynamic penetration testing is undertaken generally in accordance with BS EN ISO

22476-2:2005+A1:2011 Geotechnical investigation and testing. Field testing Dynamic

probing.

2.7 Standard Penetration Tests

Standard penetration testing is undertaken generally in accordance with BS EN ISO

22476-3:2005+A1:2011 Geotechnical investigation and testing. Field testing

Standard penetration test.

2.8 Borehole Falling Head Test

A borehole falling head test involves filling a shallow depth dynamic sampler

borehole with water. The depth to the water level in the hole is recorded using an

electronic dip meter at regular intervals until the water has dissipated, or over a

suitable period of typically 60 minutes. The results are used to determine an

approximate soil permeability in accordance with a method derived from

BS5930:1999+A2:2010. This method of testing should only be considered to give an

indication of the potential suitability of using conventional soakaways and may

require confirmation of design parameters through other techniques.

2.9 Monitoring Groundwater & Ground Gas

Groundwater monitoring is undertaken using an electronic dip meter, which records

the depth to water in a standpipe.

Ground gas composition and flow monitoring is undertaken where standpipes have

been installed. Both flow (litres per hour) and composition (%) are measured using

an infra-red gas monitor, calibrated for methane, carbon dioxide & oxygen. Records

are also taken of atmospheric pressure. The monitoring field records are presented in

Appendix III.


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2.10 Chemical Analysis

The results of the chemical analysis are presented in Appendix IV.

2.11 Geotechnical Testing

The results of the geotechnical testing are presented in Appendix V.

2.12 Screening Assessment Criteria

In the absence of a complete regulatory set of screening values derived using the

Contaminated Land Exposure Assessment (CLEA) Framework, Delta-Simons will

refer to the following:

The Soil Guidance Values (SGVs) published by the Environment Agency;

Category 4 Screening Levels (C4SLs) published by Defra;

Suitable for Use Levels for Human Health Risk Assessment (S4ULs)

published by Land Quality Management (LQM)/Chartered Institute of

Environmental Health (CIEH);

The guidance values produced by the Environmental Industries Commission

(EIC), the Association of Geotechnical and Geoenvironmental Specialists

(AGS) and Contaminated Land: Application in Real Environments (CL:AIRE)

in December 2009; and

In house Generic Screening Values (HH-GSVs) derived by Delta-Simons and

other non UK values where considered relevant.

Delta-Simons adopted Human Health Generic Assessment Criteria for a commercial

end-use are presented in Appendix VI.

The Delta-Simons methodology for soil screening assessment comprises comparison

of limited chemical analysis results with the criteria for the most sensitive plausible

end-use scenario in the proposed scheme.

Exceedance of criteria indicates that risk above “minimal” level may exist in a worst-

case scenario across the whole site. The precautionary principle is applied with

respect to protection of human health recommending; further risk assessment

(increased characterisation including extents/zones), or site-wide remediation.


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Criteria such as C4SLs may be used to describe sites with a “low” level of risk that

could be considered acceptable in a specific development scenario following further

assessment. Remediation is likely to be recommended where C4SL criteria is

exceeded.

If no criteria exceedance is observed, the Report may still recommend further risk

assessment, or remediation due to uncertainty over full characterisation of the Site.

Post-report action should be Site-specific and based on a Client’s resource/risk

profile in undertaking developments in accordance with any regulator requirements.


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3.0 RESULTS & INTERPRETATION

3.1 Desk Study

Site Description & Walkover (Reconnaissance, Internet Air Photography)

The Site comprised an irregular shaped parcel of land measuring approximately 85 m by 147 m (at its greatest extents) located on the Hewett School Site, off Cecil Road, Norwich; approximately 1.9 km south of the centre of Norwich, Norfolk. A walkover was undertaken on 6th January 2016. The relevant features identified during the walkover are shown in Figure 2 and are described below. The Site comprised a grass landscaped school field, with an existing playing court with asphalt surfacing. The Site was bounded by a metal security fence to the south, hedgerow to the east and mature and semi mature trees to the west. The north of the Site was open to the surrounding school buildings. The adjacent school buildings were low rise, and of a mixture of brick and wooden cladding construction. There were no buildings on-Site. The Site was generally flat in accordance with the surrounding area. Below ground services are known to cross the Site. The surrounding area comprised school buildings and field to the north and west, football pitches to the south, and residential properties to the east. No evidence was observed of potential contamination from fuel tanks, hazardous material stores, soil stockpiles or invasive plants. Online aerial imagery shows the Site as unchanged from 1999 to the present day.

Map Geology & Commentary (British Geological Survey (BGS) 1:50,000 Scale Mapping)

The BGS mapping shows the Site is situated on superficial deposits of the Lowestoft Formation (Diamicton). The underlying bedrock geology is Crag Group (Sand and Gravel) to the west, with bedrock of Chalk possibly to the east. Leet Hill Sand and Gravel Member are shown off-Site to the north.

Historical small-scale mineral extraction has been recorded off-Site There is no evidence in the mapping researched that the Site has been affected.

The geology is susceptible to the formation of dissolution features which may have an increased frequency at geology changes for instance from clay to granular materials.

Unexploded Ordnance (UXO) (Norfolk County Council WWII Bomb Map)

World War II bomb strikes were recorded off-Site in the surrounding area to the south-east.

MACC international categorise the Site as having a low UXO risk rating.


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Radon (EPS Environmental Desk Study Report)

The Site is in a lower probability radon area, as less than 1% of homes are above the action level and where radon protection measures are not required.

Topographic Elevation (Ordnance Survey (OS) Map)

Approximately 35 to 37 m above Ordnance Datum (m aOD).

Depth to Groundwater (Interpretation from OS Map, Geology)

At least 20 m depth below ground level and not anticipated within the depth of normal excavations. Perched groundwater may be present above cohesive layers in the unsaturated zone.

Wider Environment Sensitive Receptors (EA Web Site, OS Map)

In terms of groundwater vulnerability, the Site is on the boundary of an area classified as a Secondary A/Secondary Undifferentiated Aquifer with respect to superficial geology, and Principal Aquifer with respect to the bedrock geology. The Site is within a Source Protection Zone (SPZ); Zone 2. The Site has no significant water features within a 250 m radius. The Site is not indicated to be at risk from flooding from rivers or the sea.

Previous Third Party Report (EPS Environmental Desk Study Report)

The report was completed for an area comprising the Site, including grass landscaped school fields, and the existing hard play court. Historically, the area comprised undeveloped agricultural land until 1928. Mapping from 1938 showed development off-Site to the north-east, with some buildings encroaching the Site to the north and east. Mapping from 1958-1959 showed buildings present on the east of the Site, and substantial residential development in the surrounding area. By 1969-1970 these buildings are assumed demolished, and the Site is as it is in the present day. Off-Site, Tuckswood Farm is noted to the south west until 1958. Allotment gardens were also present to the north until 1938. The main school building becomes apparent in the north from at least 1958. The report was completed for assumed development of a new school, and associated community facilities. World War II bomb strikes were recorded off-Site in the surrounding area to the south east, although MACC international categorise the Site as having a low UXO risk rating.

Key Contaminants and CSM Aspects

The Site does not have a clearly identified significant former industrial land use and there are no related key contaminants. The Site comprised a grass landscaped school field, with an existing playing court with asphalt surfacing. On-Site potential sources of contamination include:

Potential made ground below hardstanding; and

Unknown demolition including the potential for ACM in soil.


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Off-Site potential sources of contamination are considered small, distant or are unlikely to have affected the Site.

No significant sources of ground gas have been identified on/off-Site.

The Site is on the boundary between a Secondary A/Secondary Undifferentiated Aquifer with respect to superficial geology, and Principal Aquifer with respect to the bedrock geology.

The Site is within an SPZ; Zone 2. Redevelopment is proposed that will introduce sensitive receptors. The surrounding area was subject to WWII bombing. The geology has potential for dissolution features. There is uncertainty because unrecorded potentially contaminative activities could have taken place.

3.2 Fieldworks Interpretation

Scope of Investigation

Dynamic sampler boreholes – 5 No. Dynamic penetration tests – 10 No. Borehole falling head test – 3 No. Site Area = 1.4 hectares (approx.)

Geology from the Boreholes

Made Ground/topsoil comprising dark orange brown variable slightly clayey gravelly sand to depths of 0.22 m bgl and 0.88 m bgl. Gravel was a mixture of brick, flint and concrete. DS101 had a surface layer of asphalt from ground level to 0.09 m bgl. The underlying natural soils comprised variable orange brown clayey gravelly sand, and variable orange brown sandy/gravelly clays. Gravel was chalk and flint. There were no visual or olfactory indications of significant contamination in the Made Ground or the natural soil. The natural soil was considered to represent the published superficial geology for the Site. Bedrock was not believed to have been encountered. Groundwater was not encountered during drilling. There were no indications that dissolution features were encountered, but the boreholes were widely spaced.

Penetration Test Data (DPTs or SPTs)

DPT101 to DPT105 generally recorded variable low to moderate resistance to penetration to scheduled completion depths of 6.00 m bgl.


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DPT106 to DPT110 recorded variable low to moderate resistance to penetration to scheduled completion depths of 10.00 m bgl. High resistance is shown in DPT106, DPT107, DPT109 and DPT110 from approximately 8.50 m bgl which is anticipated to reflect a change in geology. The variation in penetration resistance is considered to be due to the presence of mixed and layered distribution of soft to stiff clays and loose to medium dense gravelly sand.

Borehole Falling Head Test Data

One fill of boreholes DS104, DS105, DS107 were completed. Falling head test results of 3.75 x 10-7, 1.95 x 10-7 and 1.11 x 10-7 m/s were calculated.

Groundwater in Standpipes

13/01/2016, 20/01/2016 and 27/01/2016. DS101: Groundwater at 1.92 m bgl. DS102: dry to base 2.89 m bgl. DS103: Groundwater at 1.84 m bgl..

Gas in Standpipes 13/01/2016, 20/01/2016 and 27/01/2016. DS101, DS102, DS103 summary of worst case readings: The peak concentration for methane was 1.6 % v.v (steady 0.1 % v.v.) and for carbon dioxide was 1.6 % v.v. The minimum concentration for oxygen was 16.5 % v.v. The maximum flow rate was < 0.1 l/hr. Atmospheric pressure at ground level ranged between 997 and 1012 mb.

Chemical Analysis Six samples were scheduled for the following analytes: CLEA metals suite, TPH (total), speciated PAH (EPA-16) and an asbestos screen. The results have been compared to the most sensitive land uses due to uncertainty over exposure circumstances and the assessment is therefore conservative. Three of the samples tested exceeded the lowest adopted criteria for lead, but the C4SL threshold for residential use was not exceeded. DS101 showed increased levels of numerous PAH’s related to contamination in imported engineering materials. Three of the samples tested were above the most conservative UK criteria for benzo(a)pyrene. Three samples tested were above the LQM criteria for benzo(b)fluoranthene, and two samples above the criteria for dibenz(a,h)anthracene. TPH was above the laboratory method detection limit in three of the samples tested. Asbestos fibres were not detected in the samples tested.

Geotechnical Moisture content determinations, plastic and liquid limits, and


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Testing California Bearing Ratio (CBR) tests were carried out. Moisture content was in the range of 10 to 25 %. Plastic and liquid limits produced a plasticity index of 17 % for DS102 at 1.50 m bgl. CBR’s were in the range 0.7 % to 1.2 %.

Foundation Recommendations

The boreholes and penetration tests have identified variable strength and variable mixed sand/gravel/clay soil types at traditional spread foundation depths and this is believed to be the Lowestoft Formation. The Lowestoft Formation is a known variable deposit and can be consistent firm to stiff clay, but here it is much more variable with frequent sand layers and low blowcount records. The Lowestoft Formation appears to be underlain by the Crag inferred from greater resistance to penetration in some of the DPTs. Unfortunately, the bedrock may also be variable and although not discovered in the investigation weak Chalk may be encountered below superficial deposits. The ground conditions are considered to be potentially suitable for traditional strip or pad foundations for small low-rise structures. Using judgement and experience with check calculations, initial assessments indicate that a site-wide allowable bearing pressure of 75 kN/m2 would be appropriate at a minimum depth of 0.9 m below existing ground level and beneath any Made Ground or unsuitable soil in orange brown sand or firm clay. The limitation on bearing capacity is mainly due to the potential for differential settlements from weak and compressible clay soils demonstrated in the DPTs adjacent to more competent strata. Local shear failure in soft clay soils is also a factor. Reinforcement of foundations is recommended where variable ground conditions are encountered (sand/clay) or the foundations deepened wholly to found within one material type. Should obviously loose/soft zones be encountered, foundation depth should be increased to more competent strata or the foundation designed to span the zone. Increased density of ground investigation may allow zoning of the proposed area of development to give allowable bearing pressure to say 100-125kN/m2 in identified zones. Due to the presence of trees/hedgerows, foundation depth should be reviewed in accordance with guidance such as NHBC Standards Chapter 4.2 as advised by Building Regulations. Where the loadings or service performance described is insufficient for the purpose of the engineering design of suitable structures, alternative foundations may be required and this is likely to be the case due to typical column loadings of educational facilities. Further investigation of the deeper geology is recommended with respect to selection of potential alternative foundations. Ground improvement by stone columns maybe feasible, but pre-augering may be necessary to penetrate stiff clays and the column toe may intercept weak chalk in places limiting the technique capacity. Piled foundations are considered to be potentially cost effective compared to ground improvement using the continuous flight auger system.


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Each system is likely to require heavy plant and a suitable working platform. Ground conditions are in general terms considered suitable for ground bearing floor slabs following suitable engineered preparation of the formation. However, for small spans, if included in redevelopment proposals, ground floor slabs are recommended to be suspended, with a naturally ventilated void and damp proof membrane (DPM) provision. Although not encountered in the boreholes, there is potential for dissolution features and relic below ground structures associated with past use of the Site. Vigilance is required during groundworks for any unusual ground conditions which, if encountered, should be reported to the Client and may warrant further investigation. Further investigation and redevelopment phases which include breaking the ground require appropriate consideration of and mitigation against UXO risk.

Pavement Design CBR was in the approximate range 0.7 to 1.2 % for sand in DS104 and clayey sand in DS105 from between 0.5 and 1.0 m bgl. CBR is dependent on the condition of the strata and could be different upon excavation to the formation subject to seasonal conditions. The use of a geotextile is recommended where variable ground conditions are encountered or across changes in strata to protect against potential differential settlement.

Contamination The Site does not have a clearly identified significant former industrial land use and there are no related key contaminants. The Site comprised a grass landscaped school field, with an existing playing court with asphalt surfacing. On-Site potential sources of contamination include:

Possible made ground/imported engineering fill below hardstanding; and

Unknown demolition including the potential for ACM in soil. Redevelopment is proposed that will introduce sensitive receptors and land-use specific risk assessments are recommended based on the results in this investigation. A robust approach may be to encapsulate soil from exposed receptors using hardstandings and clean soil cover. Vigilance on the part of the developer to ensure any unusual ground conditions that could represent contamination is reported to the Client. Although considered unlikely to be required, the advice of the local planning authority should be sought to determine whether a groundwater risk assessment is needed.

Fresh Water Pipes The local water authority should be contacted at an early stage in order that any abnormal costs can be calculated, if required.

Concrete Grade Water soluble sulphate concentrations were found to be low and the Site can provisionally be classified as Design Sulfate Class DS-1 and Aggressive Chemical Environment Class ACEC AC-1 in accordance with the BRE Special Digest 1.


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Ground Gas No significant potential sources of ground gas on or off-Site have been identified. The gas monitoring revealed low concentrations of carbon dioxide and methane and flow was low. The foundation recommendations incorporate a degree of inherent gas protection in accordance with BS 8485:2015.

Groundwater/ Drainage

The ground conditions at the Site were found to comprise variable clayey gravelly sands, and sandy/gravelly clays. Groundwater was not encountered during fieldwork, however was encountered during return monitoring assumed to be perched/percolating. The falling head tests were undertaken in sand and results of 3.75 x 10-7, 1.95 x 10-7 and 1.11 x 10-7 m/s were calculated which indicates poor drainage in cohesive soils. Surface water drainage to land may be feasible via traditional soakaways provided that can be sited within dry sand which may occur in parts of the development land. Should soakaways be proposed, full-scale testing to BRE 365 is recommended to confirm suitability and design parameters. Care is required in planning soakaway locations and they should be located at suitable distances from sensitive structures due to dissolution feature risk. Alternatives such as discharge to an existing facility should also be investigated.

Excavations Trench excavation sides cannot be guaranteed to be stable at this Site, therefore, batters and/or suitable support would be required for excavations. This would also be required where human entry is necessary.

Materials Management

Excavated soils may be suitable for use elsewhere subject to suitability for use and any necessary regulator protocols. Additional testing may be required for optimised off-Site disposal of spoil.


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Table 1: Initial Conceptual Site Model & Risk Assessment

Source Pathway Receptor Matrix Assessment Justification

Potentially contaminated soils and groundwater (from on/off-Site sources of contamination

and unrecorded on/off-Site sources)

Assumes asbestos survey and removal of all identified ACM

Geology (Vertical migration through permeable deposits

below the Site) Controlled Waters Low Risk

Small Site. No significant on/off-Site sources identified. Overlies Secondary A and Principal

Aquifers. Within SPZ. Low permeability soils and thick unsaturated

zone.

Direct contact/ingestion and inhalation of dust/fibres and

vapours, oral via plant uptake Human Health Low Risk

Potential limited sources identified. Sensitive receptors to be introduced. Limited exposure

pathways through encapsulation of the ground.

Direct contact and leaching Buildings, services and

structures Low Risk

Potential limited sources identified. Generally robust receptors.

Ground gas (from unrecorded on/off-Site sources)

Vertical and lateral migration from unrecorded on-Site and

off-Site sources

Human Health and buildings

Very Low Risk No significant sources identified. Sensitive

receptors to be introduced.

Standard risk definitions and matrices are presented in Appendix I.


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4.0 LIMITATIONS TO ENVIRONMENTAL ASSESSMENTS

This Report does not constitute a full site investigation, flood risk assessment,

invasive plant assessment, waste classification exercise, contamination, geotechnical

or asbestos survey to fulfil any particular specification except where stated explicitly.

Information was obtained, reviewed and evaluated in preparing this Report from

various external sources. Our conclusions, opinions and recommendations are

based upon this information and the information obtained during the walkover, the

Consultant does not warrant the accuracy of the information provided and will not be

responsible for any opinions expressed, or conclusions reached in reliance upon

information which is subsequently proven to be inaccurate.

The recommendations contained in this Report represent our professional opinions.

These opinions were arrived at in accordance with good practice at this time and

location, and as such are not a guarantee that the Site is free of hazardous or

potentially hazardous materials or conditions.

This Report was prepared for the sole and exclusive use of the Client and for the

specific purpose instructed as defined in Section 1 of this Report. Nothing contained

in this Report shall be construed to give any rights or benefits to anyone other than

ourselves and the Client, and all duties and responsibilities undertaken are for the

sole and exclusive benefit of the Client and not for the benefit of any other party. In

particular, this Report should not be disseminated to anyone other than the Client or

to be used or relied upon by anyone other than the Client. Use of the Report by any

other person is unauthorised and such use is at the sole risk of the user. Anyone

using or relying upon this Report, other than the Client, agrees by virtue of its use to

indemnify and hold harmless the authors from and against all claims, losses and

damages (of whatsoever nature and howsoever or whensoever arising), arising out

of or resulting from the performance of the work by the Consultant.


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This Report was prepared by:

_____________________

Malcolm Tolley Date 10th February 2016

Geoenvironmental Engineer

This Report was reviewed by:

______________________

Tim Wheeler Date 10th February 2016

Project Manager

This Report was authorised by:

______________________

James Harrison Date 10th February 2016

Technical Director

Figures

TITLE:

Site Location Plan Cecil Rd, Norwich, Norfolk NR1 2PL FIGURE NO.:

1 DATE:

Jan 2016

PROJECT NO.:

15-1091.01 DWN:

NK

TITLE:

Relevant Features Plan Hewett School, Norwich FIGURE NO.:

2 DATE:

Jan 2016

PROJECT NO.:

15-1091.01 DWN:

NK

Comments: There is uncertainty as unrecorded land use may have occurred and caused contamination that has not been identified by the observations.

PH04: Existing hard standing court.

PH05: Northern boundary and surrounding school buildings.

PH06: Metal fence along southern boundary.

PH01: Northern boundary and surrounding school buildings.

PH02: General site view and western boundary.

PH03: Hedgerow along eastern boundary.

TITLE:

Approximate Locations of Boreholes and Penetration Testing Hewett School, Norwich FIGURE NO.: 3

DATE:

Dec 2015

PROJECT NO.:

15-1091.01 DWN:

MT

North

Not to scale

Legend

DS101/ DPT101

Dynamic Sampler with Dynamic Penetration Test

DPT101 Dynamic Penetration Test

(S) Standpipe

(SA) Soakaway Test

(CBR) California Bearing Ratio Test

DS101/DPT101 (S)

DS102/DPT102 (S)

DS103/DPT103 (S)

DS104/DPT104 (SA, CBR)

DS105/DPT105 (SA, CBR)

DPT110

DPT108

DPT107 (SA, CBR)

DPT106 DPT109

Appendix I

April 2009 Page 1 of 2

RISK DEFINITIONS

Consequence to Receptor Definition Matrix Human Health Controlled Waters Buildings/Services

Severe Consequence

Acute or chronic permanent impact on

human health.

Sensitive controlled water pollution ongoing, or just about to occur.

Catastrophic collapse

Moderate Consequence

Chronic permanent impact on human health

Gradual pollution of sensitive controlled

water

Degradation of materials

Mild Consequence

Chronic temporary impact on human health

Gradual pollution of non- sensitive controlled

water

Noticeable change, non-structural

Standard Risk Matrix Severe Consequence

Moderate Consequence

Mild Consequence

Higher Probability

Very High Risk

High Risk

Medium Risk

Median Probability

High Risk

Medium Risk

Low Risk

Lower Probability

Medium Risk

Low Risk

Very Low Risk

Delta-Simons Environmental Consultants Limited

3 Henley Office Park, Doddington Road, Lincoln LN6 3QR. Switchboard: 0870 0400 012

April 2009 Page 2 of 2

Probability Definitions

Probability

Definition in Context

Higher

Positive evidence of hazard, pathway and receptor

Median

Suspect hazard, pathway, and receptor

Lower

No evidence of hazard, pathway, and receptor

Risk Rank Definitions

Rank

Definition in Context

Very High Risk Demonstrable contaminated land situation, highest threat & liability level, urgent action recommended.

High Risk Likely contaminated land situation, risk assessment and action recommended.

Medium Risk Plausible contaminated land situation, risk assessment and possible action recommended.

Low Risk Unlikely contaminated land situation, possible risk assessment and possible action.

Very Low Risk Negligible risk, no action recommended except vigilance for changes in conditions.

Delta-Simons Environmental Consultants Limited

3 Henley Office Park, Doddington Road, Lincoln LN6 3QR. Switchboard: 0870 0400 012

Appendix II

Description of Strata

ASPHALT.MADE GROUND: Dark brown silty gravelly medium to coarse SAND. Gravel is medium to coarse well rounded to angular concrete, flint and asphalt.

MADE GROUND: Orange brown medium SAND, with frequent angular brick cobbles.

Orange brown medium SAND, with bands of firm orange brown clay. (LOWESTOFT FORMATION (DIAMICTON))

Firm to stiff light brown and orange brown mottled slightly sandy gravelly CLAY. Gravel is fine to coarse well rounded to angular chalk and flint. (LOWESTOFT FORMATION (DIAMICTON))

Borehole complete at 3.00 m bgl.

LegendStrata Depth(m bgl)

0.09

0.50

0.88

2.10

3.00

Strata Thickness

(m)

(0.41)

(0.38)

(1.22)

(0.90)

Reduced Level

(mAOD)

64.34

63.93

63.55

62.33

61.43

Casing Diameter

(mm)Water

Sample Details

Depth (m) Type Ref

1

2

3

4

5

6

7

8

Test Details

Depth (m) Results

Backfill

0.10 ES

0.30 ES

0.50 ES

1.00 D

1.50 D

2.00 D

2.50 D

3.00 D

Head Office3 Henley Way, Doddington Road

Lincoln, LN6 3QRTel: +44 (0 )870 0400 012Fax: +44 (0) 1522 698393

Email: [email protected]

Project No:

Project:

15-1091.01Hole ID:

DS101Page:1 of 1

Hewett School, Norwich

Dynamic Sampler LogDate:

06/01/2016Client:

Mace Group

Remarks:1. Engineer verified logged in general accordance to BS 5930:2010.2. Area CAT scanned prior to excavation.3. Borehole remained dry on completion. 4. Installed with a 63 mm HDPE standpipe to 3.00 m bgl. 5. Hand pit to 1.20 m bgl.

Water Level Observations

Date Time Strike (m) Duration Standing

Borehole Diameter

Depth (m) Dia (mm)

3.00m 95mm

Coordinates (National Grid) / Level (mAOD):E:622901 N:306623 Level:64.43

Drilled By:J&M

Plant Used:Premier 110

Logged:GH

Checked:MT

Approved:TW

Scale:1:30


MADE GROUND: Dark brown SAND. (TOPSOIL)

MADE GROUND: Dark brown silty gravelly medium SAND. Gravel is fine to medium angular brick and flint.Soft to firm orange brown slightly gravelly sandy CLAY. Gravel is fine to medium sub-rounded to sub-angular flint. (LOWESTOFT FORMATION (DIAMICTON))

Orange brown clayey gravelly medium to coarse SAND. Gravel is fine to medium well rounded to angular flint. (LOWESTOFT FORMATION (DIAMICTON))

Orange brown medium clayey SAND, with bands of soft to firm orange brown clay. (LOWESTOFT FORMATION (DIAMICTON))



0.26

0.48

1.65

2.30

3.00

Strata Thickness

(m)

(0.26)

(0.22)

(1.17)

(0.65)

(0.70)

Reduced Level

(mAOD)

34.90

34.68

33.51

32.86

32.16

Casing Diameter

(mm)Water

Sample Details

Depth (m) Type Ref

1

2

3

4

5

6

7

8

Test Details

Depth (m) Results

Backfill

0.10 ES

0.30 ES

0.50 ES

1.00 D

1.50 D

2.00 D

2.50 D

3.00 D




Project No:

Project:

15-1091.01Hole ID:

DS102Page:1 of 1



06/01/2016Client:

Mace Group




Borehole Diameter

Depth (m) Dia (mm)

3.00m 95mm


Drilled By:J&M


Logged:GH

Checked:MT

Approved:TW

Scale:1:30


TOPSOIL: Orange brown SAND.

Orange brown and yellowish brown slightly gravelly medium to coarse SAND, with occasional bands of firm to stiff grey and orange brown mottled clay. Gravel is coarse rounded flint. (LOWESTOFT FORMATION (DIAMICTON))

Soft to firm light brown and grey mottled gravelly CLAY. Gravel is fine to coarse well rounded to angular chalk and flint. (LOWESTOFT FORMATION (DIAMICTON))



0.24

2.16

3.00

Strata Thickness

(m)

(0.24)

(1.92)

(0.84)

Reduced Level

(mAOD)

35.19

33.27

32.43

Casing Diameter

(mm)Water

Sample Details

Depth (m) Type Ref

1

2

3

4

5

6

7

8

Test Details

Depth (m) Results

Backfill

0.10 ES

0.30 ES

0.50 ES

1.00 D

1.50 D

2.00 D

2.50 D

3.00 D




Project No:

Project:

15-1091.01Hole ID:

DS103Page:1 of 1



06/01/2016Client:

Mace Group




Borehole Diameter

Depth (m) Dia (mm)

3.00m 95mm


Drilled By:J&M


Logged:GH

Checked:MT

Approved:TW

Scale:1:30



MADE GROUND: Dark brown gravelly SAND. Gravel is fine to coarse rounded to angular brick and flint. (TOPSOIL)Orange brown clayey medium SAND. (LOWSESTOFT FORMATION (DIAMICTON))Soft to firm orange brown sandy CLAY. (LOWESTOFT FORMATION (DIAMICTON))Orange brown and yellowish brown medium SAND, with frequent bands of firm orange brown clay. (LOWESTOFT FORMATION (DIAMICTON))

Firm light brown and grey gravelly mottled CLAY. Gravel is fine to coarse well rounded to angular chalk and flint. (LOWESTOFT FORMATION (DIAMICTON))



0.25

0.38

0.630.75

2.59

3.00

Strata Thickness

(m)

(0.25)

(0.13)

(0.25)

(0.12)

(1.84)

(0.41)

Reduced Level

(mAOD)

34.63

34.50

34.2534.13

32.29

31.88

Casing Diameter

(mm)Water

Sample Details

Depth (m) Type Ref

1

2

13

4

5

6

7

8

Test Details

Depth (m) Results

Backfill

0.10 ES

0.30 ES

0.50 ES0.50 -1.00

B

1.00 D

1.50 D

2.00 D

2.50 D

3.00 D




Project No:

Project:

15-1091.01Hole ID:

DS104Page:1 of 1



06/01/2016Client:

Mace Group

Remarks:1. Engineer verified logged in general accordance to BS 5930:2010.2. Area CAT scanned prior to excavation.3. Borehole remained dry on completion. 4. Hand pit to 1.20 m bgl.



Borehole Diameter

Depth (m) Dia (mm)

3.00m 95mm


Drilled By:J&M


Logged:GH

Checked:MT

Approved:TW

Scale:1:30



MADE GROUND: Orange brown clayey gravelly SAND., with occasional charcoal fragments. Gravel is medium to coarse angular brick.Orange brown clayey medium SAND, with frequent bands of soft to firm orange brown clay. (LOWESTOFT FORMATION (DIAMICTON))

Orange brown medium SAND. (LOWESTOFT FORMATION ((DIAMICTON)

Firm to stiff brown and greyish brown mottled CLAY. (LOWESTOFT FORMATION (DIAMITION))



0.22

0.50

1.48

2.87

3.00

Strata Thickness

(m)

(0.22)

(0.28)

(0.98)

(1.39)

(0.13)

Reduced Level

(mAOD)

33.96

33.68

32.70

31.31

31.18

Casing Diameter

(mm)Water

Sample Details

Depth (m) Type Ref

1

2

13

4

5

6

7

8

Test Details

Depth (m) Results

Backfill

0.10 ES

0.30 ES

0.50 ES0.50 -1.00

B

1.00 D

1.50 D

2.00 D

2.50 D

3.00 D




Project No:

Project:

15-1091.01Hole ID:

DS105Page:1 of 1



06/01/2016Client:

Mace Group

Remarks:1. Engineer verified logged in general accordance to BS 5930:2010.2. Area CAT scanned prior to excavation.3. Borehole remained dry on completion. 4. Hand pit to 1.20 m bgl.



Borehole Diameter

Depth (m) Dia (mm)

3.00m 95mm


Drilled By:J&M


Logged:GH

Checked:MT

Approved:TW

Scale:1:30


TOPSOIL: Dark brown SAND.

Dark brown slightly clayey silty medium SAND. (LOWESTOFT FORMATION (DIAMICTON))Orange brown slightly gravelly clayey SAND. Gravel is fine to coarse rounded to angular flint. (LOWESTOFT FORMATION (DIAMICTON))

Hand pit complete at 1.20 m bgl.


0.26

0.50

1.20

Strata Thickness

(m)

(0.26)

(0.24)

(0.70)

Reduced Level

(mAOD)

34.22

33.98

33.28

Casing Diameter

(mm)Water

Sample Details

Depth (m) Type Ref

1

Test Details

Depth (m) Results

Backfill

0.50 -1.00

B




Project No:

Project:

15-1091.01Hole ID:

HDTP107Page:1 of 1


Hand Pit LogDate:

07/01/2016Client:

Mace Group

Remarks:1. Engineer verified logged in general accordance to BS 5930:2010.2. Area CAT scanned prior to excavation.3. Borehole remained dry on completion.



Pit Diameter

Depth (m) Dia (mm)

1.20m 95mm


Excavated By:J&M


Logged:GH

Checked:MT

Approved:TW

Scale:1:30

Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

Dynamic Probe Blows vs. Depth (m)

10 20 30 40

244

32

111

233

4444

3444

855

4444

37

5333

211

2111

2222

11

222

Torque (kg/m)

1.0

1.0

5.0

4.0

4.0




Project No:

Project:

15-1091.01Hole ID:

DPT101Page:1 of 1


Dynamic Probe LogDate:

06/01/2016Client:

Mace Group

BS EN ISO 22476-2:2005 63.5 kg Hammer Mass 750 mm Standard Drop 50 mm Cone Base Diameter 38 mm Rod Diameter

Coordinates (National Grid)/Level (mAOD): Dilled By: Plant Used: Logged By: Checked By: Approved By: Scale:

E:622881 N:306651 Level:35.16 J&M Premier 110 GH MT TW 1:50

Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

11

22

344

333

433

77

866

7555

433

23

2222

48

1010

98

55

455

444

355

Torque (kg/m)

4.0

4.0

0.0

2.0

3.0




Project No:

Project:

15-1091.01Hole ID:

DPT102Page:1 of 1



06/01/2016Client:

Mace Group




Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

66

43

11

422

11

222

12

122

111

25

65

4333333

23

222222222

1111

Torque (kg/m)

2.0

3.0

3.0

3.0

4.0




Project No:

Project:

15-1091.01Hole ID:

DPT103Page:1 of 1



07/01/2016Client:

Mace Group




Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

56

46

107

566

755

32

333

222

12

677

68

77

666

555

455

4333333333

Torque (kg/m)

3.0

4.0

5.0

4.0

5.0




Project No:

Project:

15-1091.01Hole ID:

DPT104Page:1 of 1



06/01/2016Client:

Mace Group




Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

1111

21

44

566

89

74

21

24

23

111

21

21

22

42

35

688

6555

899

1112

1415

Torque (kg/m)

0.0

1.0

1.0

2.0

5.5




Project No:

Project:

15-1091.01Hole ID:

DPT105Page:1 of 1



06/06/2016Client:

Mace Group




Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

44

3333

53

24

866

433

53333

4333

43

24

33

512

1313

1211

10999

89

109

1012

108

9999

1010

89

89

1088

71010

86

566

7666

712

1710

44

55

1220

222424

26

Torque (kg/m)

0.0

3.0

6.0

6.0

6.0

5.0

4.0

10.0

17.0




Project No:

Project:

15-1091.01Hole ID:

DPT106Page:1 of 1



07/01/2016Client:

Mace Group




Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

4444

32

1222

32

333333333

233

43333

44444

56

55

677

6777

89

79

89

87

88

77

899

75

43

433

22

344

55

444

22

411

2530

3337

4140

41

Torque (kg/m)

0.0

2.0

3.0

3.0

3.0

4.0

4.0

5.0

18.0




Project No:

Project:

15-1091.01Hole ID:

DPT107Page:1 of 1



07/01/2016Client:

Mace Group




Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

2222

344

677

42

35

333

2111

22

11

35

34

32

12

16

99

888

97

65

66

76

4666

76

766

57

88

65

67

66

55

3444

222

11

222

34

58

1416

17

Torque (kg/m)

0.0

2.0

3.0

4.0

4.5

3.0

4.0

2.5

3.0




Project No:

Project:

15-1091.01Hole ID:

DPT108Page:1 of 1



07/01/2016Client:

Mace Group




Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

2333

44

34444

54

577

910

1210

99

1010

98888

799

1010

98

76

91010

88

7777

45

88

65

4444

35

66

555

76

766

87

44

58

1526

2931

3234

3736

3739

4443

45

Torque (kg/m)

0.0

3.0

3.0

3.0

3.0

2.0

2.0

3.0

9.0




Project No:

Project:

15-1091.01Hole ID:

DPT109Page:1 of 1



07/01/2016Client:

Mace Group




Depth(m)

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5


10 20 30 40

322

34

53

43

44

54

544

54

34444

55

6777

910

99

119

1110

87

87

677

1012

1412

1114

129

89

1011

109

88

101010

89

1011

1211

1212

1415

1619

2324

2729

3032

3439

3738

4142

44

Torque (kg/m)

4.5

9.0

9.0

7.0

8.0

9.0

11.0

14.5

17.0




Project No:

Project:

15-1091.01Hole ID:

DPT110Page:1 of 1



07/01/2016Client:

Mace Group




of

k 3.540E-07unsat = m/s

Saturated

Location: DS104Borehole Falling Head TestEngineer:Status:

Hewett School James and Milton Drilling LtdHand tools

RE

SU

LTR

ULE

S

2. Enter all values in shaded cells: A , F , L and k are calculated automatically in the spreadsheet.

5. If groundwater level is below test, k is not permeability, but a result of the test. 6. Usually t1 =0 and t2=60, input H at these times.

Norwich

1. A borehole location MUST be entered to generate k .

3. Head is measured to the base of the BH, or use WL if higher.4. End conditions referenced in BS 5930 see notes . Usually d.

e= Soil in casing with bottom at impervious boundaryf= Soil in casing with bottom in uniform soil

d = Well point or hole extended in uniform soil

GR

AP

H

Borehole End Condition (important to get right)

Intake factor, FVariable Head, H 1Time, t 1 Variable Head, H 2Time, t 2

a = Soil flush with bottom at impervious boundaryb= Soil flush with bottom in uniform soil

Casing Depth

Casing Diameter, DCross sectional area of casing, AHeight of casing above ground levelApproximate long term water table (or base of BH see rules)

c = Well point or hole extended at impervious boundary

mmin

min0.640

60

0.0119

3

2.0848

m

0.33001.8786

m

mm

m

d

0.800

m

0.011 m

2.0848m

0.0121

0.2400

Difference in Length between bottom of casing/borehole, LWater Depth

1.2000.000

0.1201.200

60.00 0.560 0.640

40.00 0.550 0.65050.00 0.550 0.650

20.00 0.520 0.68030.00 0.540 0.660

12.00 0.480 0.72015.00 0.500 0.700

7.00 0.440 0.76010.00 0.460 0.740

3.00 0.400 0.8005.00 0.430 0.770

0.00 0.3001.200

0.9001.00 0.380 0.820 0.900

0.300

INP

UT

PA

RA

ME

TER

S

General Approach (after BS 5930:1999 ): Where :

Time (min) Water Depth (m) Head (m) mBorehole Depth

Ais the permeability of the soil (see rules below)

FH 1H 2 is the variable head measured at time t2 after the commencement of the test

is the variable head measured at time t1 after the commencement of the testis the intake factoris the cross sectional area of the borehole casing

© Delta-Simons Environmental Consultants Limited. No part of this document may be reproduced unless prior writtenpermission has been granted.

Proforma: C130

Project No:Client:Location:Project Name:

k

FIE

LD M

EA

SU

RE

ME

NTS

Date:Sheet:

MT

06/01/20161 1

Mace Group15-1091.01

Co-ords (X,Y):Plant Used:Contractor:

Level (Z):

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0.00 10.00 20.00 30.00 40.00 50.00 60.00

Hea

d (m

)

Time (min)

1

2 1 2

lo g eA Hk

F t t H

of


Saturated



RE

SU

LTR

ULE

S



Norwich





GR

AP

H




Casing Depth



mmin

min0.630

60

0.0151

3

1.7850

m

0.33001.5925

m

mm

m

d

0.700

m

0.011 m

1.7850m

0.0154

0.2400


1.2000.000

0.1201.200

60.00 0.570 0.630

40.00 0.550 0.65050.00 0.560 0.640

20.00 0.530 0.67030.00 0.540 0.660

12.00 0.530 0.67015.00 0.530 0.670

7.00 0.520 0.68010.00 0.530 0.670

3.00 0.500 0.7005.00 0.510 0.690

0.00 0.5001.200

0.7001.00 0.500 0.700 0.700

0.500

INP

UT

PA

RA

ME

TER

S







Proforma: C130


k

FIE

LD M

EA

SU

RE

ME

NTS

Date:Sheet:

MT

06/01/20161 1



Level (Z):

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.00 10.00 20.00 30.00 40.00 50.00 60.00

Hea

d (m

)

Time (min)

1

2 1 2

lo g eA Hk

F t t H

of


Saturated



RE

SU

LTR

ULE

S



Norwich





GR

AP

H




Casing Depth



mmin

min0.830

60

0.0119

3

2.0848

m

0.33001.8786

m

mm

m

d

0.890

m

0.011 m

2.0848m

0.0121

0.2400


1.2000.000

0.1201.200

60.00 0.370 0.830

40.00 0.350 0.85050.00 0.360 0.840

20.00 0.330 0.87030.00 0.340 0.860

12.00 0.320 0.88015.00 0.320 0.880

7.00 0.310 0.89010.00 0.310 0.890

3.00 0.310 0.8905.00 0.310 0.890

0.00 0.3001.200

0.9001.00 0.300 0.900 0.900

0.300

INP

UT

PA

RA

ME

TER

S







Proforma: C130


k

FIE

LD M

EA

SU

RE

ME

NTS

Date:Sheet:

MT

06/01/20161 1



Level (Z):

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0.00 10.00 20.00 30.00 40.00 50.00 60.00

Hea

d (m

)

Time (min)

1

2 1 2

lo g eA Hk

F t t H

KEY TO BOREHOLE AND TRIAL PIT LOGS

Document No: D104 Version: 1.0 Issue Date: 30/04/15 Author: D Ellis Authorised by: R Griffiths Page: 1 of 2

© Delta-Simons Environmental Consultants Limited. No part of this document may be reproduced unless prior written permission has been granted.

MATERIAL LEGENDS

Topsoil

Made Ground

Made Ground 2

Concrete

Clay

Silt

Sand

Gravel

Peat

Cobbles

Boulders

Mudstone

Siltstone

Sandstone

Limestone

Chalk

Coal

Breccia

Conglomerate

Igneous

Metamorphic

Volcanoclastic

Gypsum

Shale

Ironstone

Bedrock (Unidentified)

Void

INSTALLATION / BACKFILL LEGENDS

Sand

Gravel

Bentonite

Cement/Grout

Arisings

Concrete

Plain Pipe

Slotted Pipe

Piezometer Tip

Legend symbols in general accordance with BS 5930 (1999) and AGS.

KEY TO BOREHOLE AND TRIAL PIT LOGS

Document No: D104 Version: 1.0 Issue Date: 30/04/15 Author: D Ellis Authorised by: R Griffiths Page: 2 of 2

© Delta-Simons Environmental Consultants Limited. No part of this document may be reproduced unless prior written permission has been granted.

SAMPLE TYPES

ACM Asbestos Containing Material Sample

B Bulk Disturbed Sample

BLK Block Sample

C Core Sample

CBR Undisturbed Sample for California Bearing Ratio Test – 154mm diameter

D Disturbed Sample - Tub

ES Soil Sample for Environmental Testing

EW Water Sample for Environmental Testing

J Disturbed Sample - Jar

U Undisturbed Driven Tube Sample – 70/102mm diameter, 450mm long

U(P) Undisturbed Pushed Piston Sample – 102mm diameter, 450mm long

U(TW) Undisturbed Thin Walled Push In Sample – 100mm diameter, 450mm long

V Disturbed Sample - Vial

TEST TYPES

CPT Cone Penetrometer Test (kN/m2)

FID Flame Ionisation Detector Test (ppm)

HSV In-Situ Hand Sheer Vane Test (kN/m2)

PID Photoionisation Detector Test (ppm)

SPT (S) Standard Penetration Test – Split Spoon Sampler

SPT (C) Standard Penetration Test – Solid 60 Degree Cone

CORE DETAILS

If Fracture Spacing (mm) – Minimum, Average, Maximum

NI Non-Intact where >25 fracture spacings per metre

TCR Total Core Recovery (%)

SCR Solid Core Recovery (%)

RQD Rock Quality Designation (%)

AF Air Flush Return (%)

WF Water Flush Return (%)

WATER COLUMN DETAILS

First Water Strike, Second Water Strike etc.

Standing Water Level – First Strike, Second Strike etc.

Seepage

Appendix III

Project Number:

Personnel:

Flow

Pea

k

Flow

Ste

ady

CH

4 Pea

k

CH

4 Ste

ady

CO

2 Pea

k

CO

2 Ste

ady

O2 M

in.

O2 S

tead

y

Atm

osph

eric

Pr

essu

re

PID

Wel

l I.D

.

Dep

th to

Pr

oduc

t (D

TP)

Prod

uct

Thic

knes

s

Dep

th to

W

ater

(DTW

)

Dep

th to

Bas

e (D

TB)

Hei

ght o

f W

ater

Col

umn

(L/hr) (L/hr) (%v/v) (%v/v) (%v/v) (%v/v) (%v/v) (%v/v) (mb) (ppm) (mm) (m) (m) (m) (m) (m)DS101

Appendix IV

Chemtest Ltd.

Depot Road

Newmarket

CB8 0AL

Tel: 01638 606070


Report No.: 16-00490-1

Initial Date of Issue: 18-Jan-2016

Client Delta Simons

Client Address: 3 Henley Office Park

Doddington Road

Lincoln

Lincolnshire

LN6 3QR

Contact(s): Malcolm Tolley

Project 15-1091.01 Hewett School, Norwich

Quotation No.: Date Received: 12-Jan-2016

Order No.: 4574 Date Instructed: 12-Jan-2016

No. of Samples: 9 Target Date: 18-Jan-2016

Turnaround (Wkdays): 5 Results Due: 18-Jan-2016

Date Approved: 18-Jan-2016

Approved By:

Details: Phil Hellier, Project Director

Final Report

Page 1 of 4

Results - Soil

Client: Delta Simons 16-00490 16-00490 16-00490 16-00490 16-00490 16-00490 16-00490 16-00490 16-00490

Quotation No.: 238969 238970 238971 238972 238973 238974 238975 238976 238977

Order No.: 4574 DS101 DS102 DS102 DS103 DS104 DS105 DS101 DS101 DS102

ES2 ES1 ES2 ES1 ES1 ES2 ES3 D4 D4

SOIL SOIL SOIL SOIL SOIL SOIL SOIL SOIL SOIL

0.30 0.10 0.30 0.10 0.10 0.30 0.50 1.00 1.00

06-Jan-2016 06-Jan-2016 06-Jan-2016 06-Jan-2016 06-Jan-2016 06-Jan-2016 06-Jan-2016 06-Jan-2016 06-Jan-2016

Determinand Accred. SOP Units LOD

ACM Type U 2192 N/A - - - - - -

Asbestos Identification U 2192 % 0.001No Asbestos

Detected

No Asbestos

Detected

No Asbestos

Detected

No Asbestos

Detected

No Asbestos

Detected

No Asbestos

Detected

Moisture N 2030 % 0.020 7.6 19 14 20 19 13 12 15 11

Stones N 2030 % 0.020 < 0.020 < 0.020

Soil Colour N 2040 N/A brown brown brown brown brown brown brown brown brown

Other Material N 2040 N/A stones roots roots roots roots stones, roots stones none stones

Soil Texture N 2040 N/A sand sand loam sand loam sand sand clay loam

pH M 2010 N/A 7.3 9.3 8.0 7.6

Magnesium (Water Soluble) N 2120 g/l 0.010 < 0.010 < 0.010 < 0.010 < 0.010

Sulphate (2:1 Water Soluble) as SO4 M 2120 g/l 0.010 < 0.010 < 0.010 < 0.010 < 0.010

Total Sulphur M 2175 % 0.010 0.027 0.049

Chloride (Extractable) M 2220 g/l 0.010 < 0.010 < 0.010

Nitrate (Extractable) N 2220 g/l 0.010 < 0.010 < 0.010

Ammonium M 2425 mg/kg 0.50 3.2 0.87

Sulphate (Acid Soluble) M 2430 % 0.010 0.036 0.061

Arsenic M 2450 mg/kg 1.0 20 15 11 6.2 7.2 4.0

Cadmium M 2450 mg/kg 0.10 0.28 0.23 0.19 0.12 0.17 0.13

Copper M 2450 mg/kg 0.50 22 24 30 12 22 15

Mercury M 2450 mg/kg 0.10 0.13 0.25 0.18 < 0.10 0.16 0.11

Nickel M 2450 mg/kg 0.50 28 17 20 16 21 15

Lead M 2450 mg/kg 0.50 78 120 83 27 87 54

Selenium M 2450 mg/kg 0.20 < 0.20 0.53 0.28 0.26 0.26 0.22

Zinc M 2450 mg/kg 0.50 69 89 82 47 77 55

Chromium (Trivalent) N 2490 mg/kg 5.0 26 15 17 13 17 13

Chromium (Hexavalent) N 2490 mg/kg 0.50 < 0.50 < 0.50 < 0.50 < 0.50 < 0.50 < 0.50

Total TPH >C6-C40 M 2670 mg/kg 10 4400 48 22 < 10 < 10 < 10

Naphthalene M 2700 mg/kg 0.10 7.9 0.20 0.34

geo-environmental report geotechnical category 1 proposed ......the relevant british standard...

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