Water July 2011
Preliminary Ground Investigation Report Burslem Port, Stoke on Trent
Prepared by: ...... Prepared by: .... Peter Jones Daniel Stannard Senior Engineer Principal Engineer
Checked by: Checked by: ...... Daniel Stannard Victoria Griffin Principal Engineer Senior Consultant
Approved by: ...... Chris Paterson Director
Preliminary Ground Investigation Report
Rev No Comments Checked by Approved Date by - First Issue DS CP June 2011
AECOM House, 63-77 Victoria Street, St Albans, Hertfordshire, AL1 3ER Telephone: 01727 535000 Website: http://www.aecom.com
Job No 60140243 Reference 60140243/29/GEO/02/- Date Created June 2011
“This document has been prepared by AECOM Limited ("AECOM") for the sole use of our client (the "Client") and in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AECOM and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AECOM, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AECOM.”
This document is confidential and the copyright of AECOM Limited. Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited. q:\projects\municipal infrastructure - stoke on trent - highways and civils professsional services term contract\burslem port\ground investigation report\ground investigation report geo.02.issue.docx
AECOM Preliminary Ground Investigation Report
Table of Contents
Executive Summary ...... 0 1 Introduction ...... 2 2 Site Location, Description and Development History ...... 5 3 Ground Investigation ...... 19 4 Ground Conditions...... 22 5 Contamination Assessment ...... 25 6 Foundations and Ground Engineering ...... 32 7 Recommendations for Further Works ...... 35 8 References ...... 37
Appendix A – Geotechnics Factual Report Appendix B – Summary of Geochemical Test Results Appendix C – Preliminary Design Brief Appendix D - Guidance on AECOM Approach to Contaminated Land Risk Assessment
Figure 1 Proposed Scheme Layout Figure 2 Site Location Plan Figure 3 Proposed Ground Investigation Plan
AECOM Preliminary Ground Investigation Report
Executive Summary
On the instructions of Stoke on Trent City Council, on behalf of Renew North Staffordshire, AECOM Limited has carried out a Geotechnical and Geo-environmental Desk Study and exploratory ground investigation of the site of the former Burslem Canal. The project was commissioned in order to obtain and collate information on the geotechnical and environmental characteristics of the site and thence to assess potential geo-environmental risk issues, identify potential geotechnical constraints and provide recommendations for the proposed reinstatement of the waterway. The proposed reinstated canal is indicated on Figure 1.
The site of the former Burslem Canal is located in the Middleport area of Stoke on Trent, approximately 0.5km south of Burslem town centre. The former canal, which branches from the Trent and Mersey Canal, covers a corridor of approximately 0.6km in length, and is located within a former industrial/residential area running in a valley in a north south direction. The site location is shown on Figure 2.
The Burslem branch of the Trent and Mersey Canal was opened in 1805. Wharfs and associated buildings are shown at the northern end of the canal in 1877. At that time the surrounding area comprised both residential and industrial development comprising earthenware/pottery manufacturing and a number of collieries. The canal branch is reported as suffering a series of major breaches commencing in the late 1940s, eventually resulting in closure in 1962.
The superficial geology of the site comprises Made Ground overlying Alluvium and /or Glacial Till. Below the solid geology comprises the Etruria Formation overlying the Upper Coal Measures. A number of seams have been worked within the latter stratum. Both the superficial and bedrock aquifers are classified as Minor Aquifers, with a High Vulnerability rating. The nearest Watercourses are the Barnfield Brook and Trent and Mersey Canal located immediately to the eastern and southern boundary of the site.
An exploratory investigation comprising six trial pits has been undertaken along the alignment of the former canal to ascertain the nature of the canal infill and embankment.
The results of the investigation suggest the Made Ground locally contains elevated concentrations of heavy metals, hydrocarbons and volatile organic compounds. Potential asbestos containing material was also encountered in the Made Ground at one location, associated with demolition materials.
The preliminary findings suggest that the geo-environmental risks may be perceived as low to moderate.
Ground contamination is a material consideration under planning legislation. The site may be regarded as land affected by contamination and it is anticipated that further works will be required in order to meet requirements set out in the new model conditions Planning Policy Statement 23 Planning and Pollution Control (Office of the Deputy Prime Minister, 2004). Ground remediation, if required, is likely to include excavation, removal, treatment and or disposal of the backfill material within the former canal. Detailed ground investigation and remedial options appraisal will be required in order to confirm this preliminary assessment.
The principal engineering hazards include the presence of Made Ground, adjoining over-steepened slopes, buried sub- structures, obstructions, variable ground conditions and compressible strata, perched groundwater, old retaining walls and mining subsidence.
The Made Ground on site is highly variable with unpredictable engineering properties and therefore, where significant thickness is present, it may be unsuitable for the support of structural loads without some form of treatment. Alternatively, structural loads may be transferred to competent geology present at depth using some form of driven or bored pile.
A detailed inspection of on-site and adjacent structure by an experienced structural engineer is recommended. Structural cores will also be required where retaining walls are to be assessed for re-use.
Further investigations are recommended to comprise series of boreholes along the proposed canal alignment, at the crest of adjoining slopes and at the proposed footbridge location in order to confirm ground conditions. In addition trial pitting (and structural cores where appropriate) are proposed to investigate existing foundations to adjacent structures and retaining walls, locate services/sewers and investigate areas of potential contamination. An indicative layout for the proposed ground investigation is shown in Figure 3.
1 Introduction
AECOM Preliminary Ground Investigation Report 2
1 Introduction
1.1 Aims and Objectives AECOM has been commissioned by Stoke on Trent City Council on behalf of Renew North Staffordshire to provide civil engineering advice in relation to the proposed reinstatement of the former Burslem canal branch. As part of this appointment, an exploratory ground investigation has been undertaken in order to obtain preliminary information on the geotechnical and geo- environmental ground conditions on the site. 1.2 Development Proposals The proposed development comprises the reinstatement of the watercourse on the line of the Burslem Branch Canal, which extends from a point adjoining the Trent and Mersey Canal, alongside various industrial and cleared sites to the back of Furlong Mills in Furlong Lane, Middleport. The proposed restoration is illustrated in Figure 1. The site area considered by this study is indicated on Figure 2. 1.3 Reference Documents In the preparation of this report reference was made to the following documents:
- AECOM, May 2011. Geotechnical and Geoenvironmental Desk Study Report – Burslem Port. R eference 60140243/29/GEO/01/-; hereafter know as the Desk Study Report - Geotechnics Limited, May 2011. Ground Investigation at Burslem Port Stoke on Trent. Factual Report. Reference PC114591; hereafter known as the Factual Report. 1.4 Scope of Report The scope of works for this project has included the following tasks:
- Summary and interpretation of the ground conditions encountered by the ground investigation. - Preliminary assessment of the ground-related risk posed from the soil in accordance with current practice and guidance using Generic Assessment Criteria; - Preliminary advice on the likely disposal classification for arisings from the proposed construction works; and - Preliminary assessment of the requirement, or otherwise, for any remedial action. 1.5 Limitations The information, views and conclusions drawn concerning the site are based, in part, on information supplied to AECOM by other parties. AECOM has proceeded in good faith on the assumption that this information is accurate. AECOM accepts no liability for any inaccurate conclusions, assumptions or actions taken resulting from any inaccurate information supplied to AECOM from others. The investigation itself was designed generally to meet the objectives of an exploratory investigation, as defined by BS 10175:2001 Code of Practice for the Investigation of Potentially Contaminated Site. As an exploratory investigation, the results may not provide sufficient data to make detailed estimates of the quantities involved in any remediation work, if required.
The exploratory holes carried out during the fieldwork, which investigate only a small volume of the ground in relation to the size of the site, can only provide a general indication of site conditions. The comments made and recommendations given in this report are based on the ground conditions apparent at the site of the exploratory holes. There may be exceptional ground conditions elsewhere on the site which have not been disclosed by this investigation and which have therefore not been taken into account in this report. The comments made on groundwater conditions are based on observations made during site work. It should be noted that groundwater levels might vary owing to seasonal or other effects.
The opinions expressed in this report concerning any contamination found and the risks arising there from are based on current good practice simple statistical assessment and comparison with available soil guideline values, AECOM generic assessment criteria and other guidance values.
AECOM Preliminary Ground Investigation Report 3
It should be noted that the effects of ground and water borne contamination on the environment are constantly under review, and authoritative guidance values are potentially subject to change. The conclusions presented herein are based on the guidance values available at the time this report was prepared, however, no liability by AECOM can be accepted for the retrospective effects of any changes or amendments to these values. The copyright in this document (including its electronic form) shall remain vested in AECOM but the Client shall have a licence to copy and use the document for the purpose for which it was provided. AECOM shall not be liable for the use by any person of the document for any purpose other than that for which the same were provided by AECOM. This document shall not be reproduced in whole or in part or relied upon by third parties for any use whatsoever without the express written authority of AECOM.
2 Site Location, Description and Development History
AECOM Preliminary Ground Investigation Report 5
2 Site Location, Description and Development History
2.1 Introduction The following section is information reported previously in the Phase 1 Geotechnical and Geo-environmental Desk Study Report (AECOM, 2011) and is reproduced for completeness. 2.2 Location The site of the former Burslem Canal is located in the Middleport area of Stoke on Trent, approximately 0.5km south of Burslem town centre. The site is centred on National Grid Reference 386600E, 349000N. A site location plan is provided as Figure 2. 2.3 Description and Geographic Setting The site, which covers a corridor of approximately 0.6km in length, is located within a former mixed industrial and residential area. Much of the surrounding area has recently been cleared to make way for proposed local regeneration works. The site is orientated in a general north south direction and is bounded at the southern end by the Trent and Mersey Canal. The western boundary comprises small industrial operations near to the junction with the Trent and Mersey Canal (Trent and Mersey) with derelict industrial buildings and then residential housing/cleared ground further north. The eastern boundary comprises a north/south split of industrial units and green open space referred to as Rodgerson’s Meadows. This is recorded as being a former landfill site. The land rises sharply from this location upwards to Grange Park to the east. A topographical survey of the site was carried out in March 2011. This shows the level along the line of the former canal to be generally consistent varying between 123m AOD and 124m AOD with a slight level rise noted at either end of the site. Water level in the Trent and Mersey Canal typically stands at 124.55m OD (Arup, 2005). Ground levels generally fall towards the east. This results in, over the southern 300m of the site, the former canal being supported on steep embankment to its eastern flank. The toe level of the embankment varies between 117.5m AOD and 118.5m AOD resulting in an embankment height of c.6m. A watercourse runs along the embankment toe discharging into a culvert under the Trent and Mersey Canal.
Along the northern half of the site, ground level along the line of the proposed channel is largely at grade with the adjacent land to the east.
The ground level bordering the western side of the proposed channel also varies considerably along the alignment. At the southern end of the site the ground adjacent is up to around 4m higher, sloping down to the former canal level. The adjacent ground then lowers to be approximately 1m above the level of the former canal. The ground then rises with the northern half of the western boundary comprising a moderately steep slope with a maximum crest level of 131m AOD along Navigation Road resulting in a slope height up to c.7m. 2.4 Site Walkover Survey The southern boundary of the site is marked by the Trent and Mersey Canal. The route of the proposed canal heads north for around 150m, with ground sloping up to the west by around 2 to 4m, beyond which are industrial units. Immediately to the east of the proposed canal, the ground falls steeply by approximately 6m to a boggy water course. A large concrete inlet headwall is visible, which is thought to take the watercourse beneath the Trent and Mersey Canal to the south. Beyond the watercourse, the ground rises up moderately and is roughly vegetated with occasional trees. A small pond is present in the angle formed by the watercourse and the Trent and Mersey.
From approximately round 150m to 300m north of the Trent and Mersey Canal, the site opens out to form a plateau approximately 30m wide. To the east is the steep fall to the watercourse described previously, whilst to the west the derelict remnants of former commercial buildings are present. One building remains standing, although it appears to be in a poor state of repair; the remainder have been demolished to ground floor level, which is approximately 1m above the ground level along the line of the proposed canal. It is thought that the buildings fronted directly onto the canal.
AECOM Preliminary Ground Investigation Report 6
Along this section of the site, the eastern bank of the former canal is also evident as concrete edging to the towpath is visible approximately 10m from and parallel to the building frontages. Approximately 275m north of the Trent and Mersey canal, Alight engineering works is located immediately to the west of the site. At the time of the visit, this was in use as a light metal engineering works. Evidence of oil spillages were visible on the concrete surfacing of the works yard. Between approximately 300m and 400m north of the Trent and Mersey Canal, the line of the proposed canal passes beside a semi-mature wooded slope which rises to the west by around 5m to the former residential street of East View. Anecdotal evidence suggests the slope encroaches over the line of the former canal and the original western bank was formed by a masonry wall, which has since been buried by the slope. To the east of the proposed channel, an operational waste management works is present. The works is partly occupied by a large brick built warehouse building thought to date form the early 19th century. To the south of the warehouse is a skip storage area. To the north of the warehouse is the works yard where waste sorting and stockpiling was undertaken at the time of the visit. The line of the relict tow path described previously turns to the west at this point indicating historically the presence of wharf area serving the warehouse. At approximately 400m north of the Trent and Mersey, the former canal is crossed east-west by a footbridge linking Navigation Road in the east and Dimsdale Street in the west.
North of the foot bridge, the land to the east of the proposed canal is generally level with a modern warehouse building and adjacent concrete hardstanding.
North of the footbridge, to the west of the proposed channel the ground rises moderately steeply, by up to approximately 6m to the former residential Bennett Street. The alley to the rear of properties fronting onto Bennett Street is supported by a red brickwork retaining wall at the top of the slope. A row of mature tree stumps is present along the toe of the slope, which is thought to mark the western bank of the former canal.
The northern end of the slope is truncated by a blue masonry retaining wall approximately 7m high and approximately 13m long orientated northeast-southwest. To the north of this retaining wall the slope continues to the north west, with a stone built retaining wall, approximately 2 to 3m high at the toe of the slope. The stone built retaining wall is in a very poor repair and has failed in places.
Significant fly tipping of various types waste such wood and metal filing cabinets and car parts were noted in the immediate surrounding lands west and east of the site.
AECOM Preliminary Ground Investigation Report 7
2.5 Information from Statutory Authorities Etc The following information has been obtained from the Landmark Envirocheck report included in the Desk Study Report. The report collates data from a variety of sources including the Environment Agency (EA) and the British Geological Survey (BGS). All data suppliers are referenced in the report. Table 2.41: Summary of Regulatory Information
Subject Number present Details On site 0-250m 250 -500m Agency and Hydrological Contaminated Land Register Entries and Notices - - - Discharge Consents 4 7 Barnsfield Brook and Trent & Mersey Canal Enforcement and Prohibition Notices - - - Agency an d Hydrological (cont’) Integrated Pollution Controls - - - Integrated Pollution Prevention and Control - - - Local Authority Integrated Pollution Prevention and - - - Control Local Authority Pollution Prevention and Controls 1 7 - Mobile crushing and screening Local Authority Pollution Prevention and Enforcements - - - Pollution Incidents to Controlled Waters - 4 - Canal, Groundwater Prosecutions relating to Authorised Processes - 2 - Navigation Road – storing waste without waste management licence Prosecutions relating to controlled waters - - - Registered radioactive substances - - - Waste BGS recorded landfill sites 1 - - Rodgerson’s Meadow Historical landfill sites 4 4 - Rodgerson’s Meadow, Cotterill Grove, Shelton Works Integrated pollution control registered waste sites - - - Licensed waste management facilities 1 1 - Navigation Road Local authority recorded landfill sites 1 1 Household waste Registered landfill sites 1 2 Rodgerson’s Meadow, Shelton Works Registered waste transfer sites 1 Navigation Road Registered waste treatment or disposal sites - - - Hazardous Substances Control of major accident hazards sites (COMAH) - 1 - Navigation Road Explosive sites - - - Notification of installations handling hazardous - - - substances (NIHHS)
AECOM Preliminary Ground Investigation Report 8
Subject Number present Details On site 0-250m 250 -500m Planning Hazardous substance consents - - - Planning hazardous substance enforcements - - - Industrial Land Use Contemporary trade directory entries 1 3 - Navigation Road and Luke Street Fuel station entries - - -
2.6 Consultees 2.6.1.1 British Waterways Board The British Waterways Board (BWB) has been contacted to determine whether there is an ongoing settlement problem in the area due to mining subsidence.
BWB has confirmed they are not currently undertaking any specific movement monitoring in the site area and have monitored for the past 5 years or so. BWB noted that historically, the amount of mining subsidence has been extreme in Stoke, and could be localised, depending on the mine workings in the area. They are aware that there has been some movement at Etruria within the last few years, but only in the order of millimetres. This they believe may have led to minor loss of watertightness in one of the lengths of the Trent and Mersey Canal walls and also one of the lock chambers, though they cannot be certain of the cause. 2.6.1.2 Burslem Port Trust A site meeting was undertaken with representatives of the Burslem Port Trust on 20 th April 2011. Discussions from this meeting are reported in Section 2.4 Site Walkover Survey. 2.7 Sensitive Land Uses The Sensitive Land Uses Map of the Envirocheck Report indicates that the site lies in a Nitrate Vulnerable Zone. 2.8 Unexploded Ordnance A pre-desk study assessment has been obtained from Zetica in order to determine the risk from unexploded ordnance to the site. This assessment is presented in the Desk Study Report.
It is recorded that during The Second World War High Explosive bombs fell within 0.5km of the site and strategic targets were present within 5km of the site. It is concluded that based on the available information on strategic targets, the intensity of bombing, the former land use and the regional military history, it is considered that the site may have a low risk of Unexploded Ordnance (UXO) being present. Based on the indicated risk, a more detailed desk study is not considered essential. A detailed desk study should be considered however where greater certainty of the risk is required. 2.9 Radon The Envirocheck report indicates that the site is not within an area affected by Radon; however, a radon assessment will be required if building structures are proposed in the future. 2.10 Development History 2.10.1 Sources of Information A review of the history of the site and adjacent area has been undertaken using historical maps dated between 1877 and 2010 (Table 3.2). The maps were obtained as part of an Envirocheck report from the Landmark Information Group, included in the Desk Study Report.
AECOM Preliminary Ground Investigation Report 9
Reference to historical Ordnance Survey (OS) maps provides invaluable information regarding the land use history of a site. However, it should be noted that historical evidence will be incomplete for the period pre-dating the first edition and between successive maps. 2.10.2 Historical Mapping The Burslem branch of the Trent and Mersey Canal was opened in 1805. Wharfs and associated buildings are shown at the northern end of the canal in 1877. At the same time, the surrounding area comprises both residential and industrial development comprising earthenware/pottery manufacturing and a number of collieries. Further development in the area continued into the late 1930s. However, the number of collieries appears to reduce from this time until no evidence of such activity in 1995. The land immediately east of the canal, leading to the Trent and Mersey Canal remained undeveloped before becoming Allotment Gardens around 1925. The area later became a refuse tip during the 1980s. The canal branch itself is reported as suffering a series of major breaches commencing in the late 1940s, eventually resulting in closure in 1962.
Further details are provided in Table 3.2. Table 2.2 Summary of Historical Ordnance Survey Mapping
Year Features on-site Features off site [scale] 1877-1879 (1:2,500) A branch canal arm is shown off the Trent and Mersey Canal, The area immediately to the north of the site is predominated following a curvilinear alignment in a northerly direction. Wharfs by industry with China and Earthenware recorded, including and associated buildings are indicated at the northern end and associated small reservoirs. To the east land is shown as along the north eastern side of the canal arm. being initially undeveloped with a mineral railway curving An embankment runs along the south eastern side of the canal from the east to a southerly direction. Brick and sewer works with a watercourse running parallel at the toe. The watercourse are indicated beyond the railway. Much of land immediately comes to a confluence with another watercourse before passing adjacent to the western side of the site is undeveloped with under the Trent and Mersey Canal. A sluice is shown on the the exception of ‘Newport House’ near the junction of the western side of the canal arm approximately 300m north of the canals with industrial buildings beyond (China and canal junction. Earthenware). Residential development predominates in the hinterland in the north west area 1879 (1:500) No significant changes. No significant changes. 1889 (1:10,560) No significant changes. Collieries and shafts are shown in areas to the north, south and immediately east of the mineral railway. The nearest colliery is located 100m east of the site, near the canal junction. Brick works and clay pits are shown throughout the area. 1899 (1:2500) Residential development has moved closer to the eastern side ‘Flint Mill’ is located between the Trent and Mersey Canal and of the canal. A corn mill is shown at the mid-point on the Newport House. western side of the canal arm with a tile works beyond. 1900 (1:10,560) No significant changes. The density of development in the surrounding area has increased. 1924-1925 (1:2500) Further encroachment of residential development along the Previously undeveloped land between the site and mineral eastern side of the canal arm with a slope indicated between. railway to the east is indicated as Allotment Gardens. Marshy Industrial buildings are shown immediately south of the Corn ground is indicated immediately south of the allotments Mill alongside the canal arm. bounded between the canal and the former mineral railway now titled the ‘Grange Branch, NSR’. Brick Works no longer evident immediately east of the railway. 1925-1926 (1:10,560) No significant changes. Grange Colliery located nearest the site is shown as disused.
AECOM Preliminary Ground Investigation Report 10
Year Features on-site Features off site [scale] Collieries elsewhere appear still active. 1937 (1:2500) Further expansion of industrial buildings adjacent to Corn Mill A pond type feature is located in the area of previously recorded marshy ground immediately south east of the site 1938 (1:10,560) No significant changes. Development between the areas of Wolstanton and Burslem increasing. 1949-1950(1:1250) ‘Crate Works’ recorded within wharf area alongside north Refuse heaps indicated in area of former Grange Colliery. eastern side of canal arm. Allotment Gardens are indicated in parcels of land between the canal arm and adjacent residential buildings along the north west boundary. 1951 (1:2500) No significant changes. No significant changes. 1951 (1:10,560) No significant changes. No significant changes. 1955 (1:10,000) No significant changes. Further development of surrounding areas. 1965-1967 (1:1250) The canal arm is no longer shown. A series of tanks are shown The railway to the east appears disused. next to the Corn Mill. A slag heap is recorded immediately adjacent to the south western edge of the former canal with a refuse tip noted in the area formerly occupied by Newport House beyond. A pond and two small associated buildings are shown to the edge of the former eastern canal arm boundary. 1967-1969 (1:10,000) No significant changes. Large Steel Works shown south of the Trent and Mersey Canal. Refuse/slag tip indicated immediately east of the railway in area of former Grange Colliery. 1970-1971 (1:2500) The alignment of the watercourse running parallel to the south No significant changes. eastern embankment toe of the former canal has been straightened and shown discharging to a headwall adjacent to the Trent and Mersey Canal. 1977-1978 (1:10,000) A pipeline is indicated running parallel to and immediately to the Collieries still shown in surrounding outlying areas. west of the watercourse. 1977-1989 (1:1250) Some of the warehouse buildings adjacent to the former A large refuse tip is located immediately east of the former eastern wharfs are no longer evident. canal arm. 1986-1989 (1:10,000) No significant changes. No significant changes. 1990-1992 (1:10,000) No significant changes. No significant changes. 1994 (1:1250) No significant changes. No significant changes. 1995 (1:10,000) No significant changes. Areas of previously recorded collieries in outlying areas redeveloped or parkland. Grange Park established east of refuse tip adjacent to former canal arm. 2000 (1:10,000) No significant changes. No significant changes. 2006 (1:10,000) No significant changes. No significant changes. 2010 (1:10,000) No significant changes Steel works no longer evident south of the Trent and Mersey Canal.
AECOM Preliminary Ground Investigation Report 11
2.10.3 Planning Authority Records Ove Arup and Partners undertook the Burslem Arm Feasibility Study in 2005, on behalf of RENEW. This reported on the key engineering, environmental, economic and planning issues contributing to the feasibility of restoring the Burslem Arm of the Trent and Mersey Canal. A summary of the salient geotechnical issues from this study are presented in Table 3.4 below. Only those supplementary to information provided elsewhere in this report are given. Table 3.4: Summary of Geotechnical/Geo-environmental factors
Report reference Comments/’Extract’ Executive Summary ‘The area has suffered from mining subsidence but this has effectively now ceased. The gro und levels at the end of the former branch are more than 1m lower than historically’. Section 1.3 History The canal arm opened in 1805 with closure in 1962 following major breaches in late 1940s/early 1950s and late 1961 due to ground movement caused by severe underground mining subsidence. The early breach is recorded occurring approximately 80m north of the junction with the Trent and Mersey Canal. Section 2.1 Due to the mining induced subsidence it was necessary to raise the embankments to maintain the required water level (124.55m Topography OD). Following the closure it is reported the canal arm was backfilled with inert fill. Section 2.4 Mining ‘… the overall effect of the pattern of mining will have lowered the ground to the east to a greater exten t than to the west, and it is possible that minor differential (a few mm per year) continues as the more disturbed ground to the east continues to consolidate. This possible minor ongoing settlement may have been enhanced in recent years by the rise in regional groundwater levels within the coal measures strata following the cessation of deep mining in the north Staffordshire Coalfield’ .
2.10.4 Historical Photographs A series of historical photographs showing the canal were provided by the committee of the Burslem Port Trust. Copies of these photographs are presented in the Desk Study Report and described In Table 3.3 below:
Table 3.3: Summary of Historical Photographs
Number Approximate Description date 1 1930s View looking north towards the Crate Works warehouse with the Corn mill to the left. Shows an open treeless space in the foreground and a large number of bottle ovens and chimneys on the horizon. The area to the east of the warehouse is occupied by allotment gardens with a cutting or embankment behind. 2 1956 View of Anderton Wharf from onboard a narrowboat. The warehouse is visible to the right with several additional buildings in the background. 3 Not known Two views of New Wharf Pottery off Navigation Road at the northern end of the site. The Canal with blockwork washwall is visible in the foreground 4 1959 Aerial view of Shelton Bar Steelworks. The high embankment supporting the Burslem Arm at the junction with the Trent and Mersey is visible at the top of the photograph. 5 1930s View north at the terminal end of the Burslem Arm. The embankment below Bennett Street is visible in the right of the picture. 6 1961 Two views following the 1961 breach. The top picture shows the breach in the washwall with the valley-bottom beyond. The lower picture shows a coal boat stranded at the Trent and Mersey junction with is thought to have been buried during the infilling works. 7 1961 Further views of the stranded coal boat following the 1961 breach. 8 1961 View of the bakery buildings following the 1961 breach. The blockwork washwall is visible on the right of the picture. Vaulted arch foundations of the bakery buildings are visible in the left of the picture.
AECOM Preliminary Ground Investigation Report 12
Number Approximate Description date 9 1962 Two views showing the infilling of the breached arm at the Trent and Mersey Junction. The sheet piles visible are likely to have been used to form the new Trent and Mersey bank. The embankment which now rises above the western bank of the former canal appears to be absent in these pictures.
2.11 Geology 2.11.1 Geological Information from Published Information and Maps The published 1:10,000 scale geological map of the area produced by the British Geological Survey (Sheets SJ84NE and SJ85SE, dated 1992 and 1991, respectively) indicates the site is underlain by the geological succession summarised in Table 4.1.1: Table 4.1.1 Geological succession from Published Mapping Group Geology Recent Made Ground (southern half of site) Quaternary Alluvium Glacial Till Upper Etruria Formation Carboniferous Upper Coal Measures
The Made Ground in the area is likely to comprise a wide variety of material including but not exclusive to industrial (pottery/earthenware) waste, domestic waste (refuse tips), and colliery spoil.
The Alluvium is described as sand with clay and gravel. The Glacial Till is described as diamicton, meaning a poorly sorted sediment of gravel sized sediment and larger in a matrix of fine grains.
The solid geology is indicated as having a dip of 10-15 degrees in a south westerly direction. A fault is indicated approximately 300m to the west running parallel to the site.
The Etruria Formation initially comprises a sandstone layer above interbedded sandstone and mudstone. Below the Upper Coal Measures comprise interbedded Sandstone, Siltstone, Mudstone and Coal. Sub-cropping coal seams are shown approximately 600m east of the site. The published 1:50,000 scale geological map of the area produced by the British Geological Survey (Sheet 123, Stoke on Trent, dated 1994) indicates mine shafts within 500m of the site. The geological cross section shown on the map passes across the north of the site. This indicates approximate vertical thicknesses of 150m and 300m for the Etruria Formation and Upper Coal Measures, respectively. The existing topography and history of development of the site suggests that, in addition to the Made Ground identified on the mapping additional areas may be present on the site. 2.11.2 Geological Information from BGS Records The British Geological Survey holds an archive of historical borehole logs throughout the UK. The database of borehole logs was searched for any records which would provide useful information on the ground profile at the site. Four borehole logs were obtained from the BGS are described below in Table 4.1.2. The BGS borehole logs are included in the Desk Study Report. Table 2.4 Exploratory Hole Log Data from BGS
AECOM Preliminary Ground Investigation Report 13
Boreholes reference Stratum 1 Description Depth to Top Level of Top Thickness (m) NGR of Stratum 2 of Stratum (m AOD) Distance from the site (m bgl) Date
SJ84NE21 Unknown Existing well (finished in green grits) GL c.131 25m 386450,349380 Etruria Formation Sequence of ‘green, grey, red brown and broken 25 106 16.6 100m N rock’. Noted ‘plentiful supply of water in grits’. April 1933 SJ84NE2625 Made Ground Tarmac and sub-base GL c.127 0.25 386500,348800 Compact slag 0.25 126.75 1.25 100m W Firm sandy clay with slag 1.5 125.5 0.5 April 1983 Possibly Glacial Firm red grey marbled clay 2 125 3 Till SJ 84NE1781 Topsoil Topsoil GL 118.85 0.3 386600,348930 On site Made Ground Soft/loose sandy clay and gravel containing 0.3 118.55 3.25 June 1989 brick, furnace waste, clinker and pottery Alluvium Soft to stiff clay and medium dense gravel 3.55 115.3 2.65 including little peaty wood debris Etruria Formation Stiff clay becoming moderately weak/moderately 6.2 112.65 >10 strong mudstone and siltstone with depth SJ84NE1782 Made Ground Firm slightly sandy clay and medium dense GL 122.4 5.8 386610,349070 gravel of brick, clinker and cobbles of concrete 20m E June 1989 Alluvium Soft clay with fibrous peaty debris and medium 5.8 116.6 >2.2 dense sandy gravel 1. The geological classification is based on information available on the logs and is therefore indicative only. 2. G.L: Ground Level 2.12 Hydrogeology 2.12.1 General Characteristics It is likely that the granular units within the glacial drift deposits have a moderate to high intergranular permeability which facilitates groundwater movement. It is likely that the clayey deposits have a lower permeability which impedes drainage and restricts groundwater movement.
Localised perched water within the Alluvium is likely to be in continuity with local watercourses with the Glacial Till likely to act as an aquiclude although perched or trapped groundwater may be present in granular layers or pockets. It is also possible that localised perched water may also be present in the Made Ground. The Etruria Formation is likely to have a generally low permeability which restricts groundwater movement. The mudstone and siltstone units of the Upper Coal Measures beneath the site have a natural low intergranular permeability which restricts groundwater movement. However, the sandstone bands within the Coal Measures are likely to have moderate intergranular permeability which supports a series of small aquifers.
The Coal Measures contain a number of coal seams which have been worked in the area. Collapse of former workings will have disrupted the structure of the geology, including low permeability mudstones and siltstones. It is likely that this will have resulted in the development of a significant secondary permeability imparted by fractures within the strata which facilitates groundwater movement.
AECOM Preliminary Ground Investigation Report 14
There is no information on the groundwater level beneath the site. Information from the BGS borehole logs SJ84NE21 located approximately 100m north of the site indicates that rest groundwater level in the Etruria Formation was approximately 9mbgl (122mAOD) in 1992. The borehole was test pumped in 1992 and had a low yield of approximately 8.1m3/hr with a drawdown of approximately 6.5m. Regionally groundwater in the permeable horizons of the Etruria and Upper Coal Measures is likely to be flowing easterly towards the River Trent and its tributaries. Shallow groundwater is also likely to be present within the alluvium in the vicinity of the site. The published Environment Agency Groundwater Vulnerability Map Sheet 17, Derbyshire and North Staffordshire classifies the superficial deposits comprising Alluvium as a Secondary-A Aquifer and the area to be designated a High Vulnerability rating. Soil information for urban areas is less reliable and based on fewer observations than in rural areas. The worst case is therefore assumed and such land is classified as having a high leaching potential until proven otherwise. The Glacial Till is classified as unproductive strata due to its low permeability. The solid geology (Etruria and Upper Coal Measures) is also classified as a Secondary-A aquifer. The above classification reflects the local importance of the bedrock aquifer for local groundwater supplies and the superficial (Alluvium) aquifer contributing to the base flow of the nearby watercourses 2.12.2 Licensed Water Abstraction The Envirocheck report indicates that there are two licensed groundwater abstractions within 250m of the site, both of which are for industrial purposes (process water). The locations are summarised in Table 4.2.2, below.
Table 4.2.2: Environment Agency licensed abstractions within a 250m radius of the site
National Grid Distance (m) Name/ Licence number Source Use Reference and direction
386490, 349350 28 N Furlong Mills Co Ltd / 03/28/01/0057 Etruria Formation? Industrial process 386410, 349400 85 N Furlong Mills Co Ltd/ 03/28/01/0057 Etruria Formation? Industrial process 386330, 349440 171 NW Dale Hall Mills Ltd/ 03/28/01/0228 Etruria Formation? Industrial process In terms of aquifer protection for groundwater abstractions, the Environment Agency generally adopts a three-fold classification of Source Protection Zones for public supply abstraction wells. - Zone I - or ‘inner source protection’ is located immediately adjacent to the groundwater source. It is based on a 50-day travel time and is designed to protect against the effects of human activity and biological/chemical contaminants that may have an immediate effect on the source.
- Zone II - or ‘outer source protection’ is larger than Zone I and is defined by a 400-day travel time to the source. The travel time is designed to provide delay and attenuation of slowly degrading pollutants. - Zone III - or ‘source catchment’ covers the complete catchment areas of a groundwater resource.
Information available on the Environment Agency’s web-site indicates that the site does not lie within a Source Protection Zone for any licensed abstractions. 2.13 Hydrology 2.13.1 Surface Watercourses and Drainage The nearest surface watercourses/features to the site appears are the Barnfield Brook running parallel to the eastern side of the site and The Trent and Mersey Canal located at the southern end of the site. Fowlea Brook runs from north west to south east approximately 400m to the west of the site at its closest point. Table 4.3.1 Surface Water Quality
AECOM Preliminary Ground Investigation Report 15
Surface Water GQA Nearest Distance (m) to site Direction Upstream / Feature Downstream Trent and Mersey C (Fairly) Good at approximately 50m 0 south Downstream Canal south; and D (Fair) at approximately 116m south west Barnfield Brook Unknown 0 east Not known Fowlea Brook C (Fairly Good) at approximately 1km Upstream north of the site
2.13.2 Surface Water Abstractions There are no surface water abstractions identified within 250m of the site. 2.13.3 Flooding The indicative floodplain map for the area, published by the Environment Agency, shows that the southern tip of the site lays within the predicted (1 in 100 year) flood plain of the Fowlea Brook. Therefore the site is considered to be susceptible to fluvial flooding. However, there are no historic records indicating that flooding has occurred. 2.14 Previous Ground Investigation A previous ground investigation was undertaken for the Middleport Phase 2 Study by Wardell Armstrong for Stoke City Council in 2005. A number of exploratory holes within the study area were located close to the site and the findings of these are summarised below in Table 4.4 below. Positions of exploratory holes are shown on the Middleport Phase 2 Development Constraints plan contained in the Desk Study Report
Table 4.4 Exploratory Hole Log Data from Middleport Phase 2 Study
Ref No. Distance and Stratum1 Description Depth to Depth to direction from Top of base of the site (m) Stratum2 Stratum (m (m bgl) bgl)
BH43 100 NW Made Ground Tarmac and Medium dense black ash, brick and pottery GL 3.0 waste Glacial Till/Etruria Formation Firm to stiff red brown and light brown silty clay. 3.0 4.4 Becoming stiff to very stiff with depth BH47 30 W Made Ground Loose dark grey silty slightly sandy angular gravel sized GL 4.7 fragments of ash, brick, clinker and pottery waste and Soft brown and grey brown sandy clay with many pottery and brick fragments Alluvium Soft brown mottled orange brown slightly organic sandy 4.7 5.1 clay Glacial Till/Etruria Formation Stiff red brown mottled light grey clay and Very stiff 5.1 8.0 friable thickly laminated red brown gravelly clay BH18A 50 E Made Ground Layers of ashy stone and tar mac, loose black clayey ash GL 3.2 with much broken brick and concrete Alluvium Very soft brown slightly sandy clay with some fine gravel 3.2 7.0 of mudstone and sandstone Glacial Till/Etruria Formation Firm/stiff becoming very stiff red/brown and gr ey mottled 7.0 8.65 slightly sandy clay with mudstone lithorelicts, becoming friable with depth BH49 30 W Topsoil Topsoil GL 0.5
AECOM Preliminary Ground Investigation Report 16
Ref No. Distance and Stratum1 Description Depth to Depth to direction from Top of base of the site (m) Stratum2 Stratum (m (m bgl) bgl)
Made Ground Loose black clayey mixture of ash, brick and concrete 0.5 6.5 fragments and Firm grey/brown clayey mixture of fine gravel and sandstone cobbles Glacial Till/Etruria Formation Firm to stiff red brown clay 6.5 8.95 BH50 10 W Topsoil Topsoil GL 02.5 Made Ground Firm to stiff grey and grey brown sandy gravelly clay 0.25 5.0 containing occasional cobbles of brick, ash and sandstone. Glacial Till/Etruria Formation Very stiff reddish brown sandy clay with gravel sized 5.0 7.65 mudstone lithorelicts. BH T1 40 E Made Ground Topsoil, concrete GL 0.4 Made Ground Soft clay with brick, timber and sandstone fragments 0.4 7.9 Glacial Till/Etruria Formation Stiff brown sandy clay 7.9 8.65 BH T5 80 E Made Ground Black ash and clay fill with much broken brick, concrete GL 8.2 and domestic refuse Made Ground Loose ash, gravel and broken brick and concrete 8.2 13 Alluvium Very soft/soft sandy gravelly clay. 14.1 16.8 Notes: 1. The geological classification is based on information available on the logs and is therefore indicative only.
2. G.L: Ground Level All the exploratory holes listed above were described as contamination ‘hot spots’ though ‘gross contamination’ was only noted in boreholes T1 and T5 within the former landfill site.
The Phase 2 study also reported a review of a Phase 1 study of the area. Salient points from the earlier study were: - Ground movement associated with deep mining activity should have been complete by the mid 1980s - Over half of the properties in the study area had been damaged by subsidence due to mining. The Phase 2 study concludes ‘Generally, there does not appear to be any ongoing ground movement, particularly abnormal ground movement associated with past mining’. 2.15 Quarrying and Landfilling Information regarding quarrying and landfilling operations, past and present that have taken place in the vicinity of the site has been obtained as part of an Envirocheck report from the Landmark Information Group, included in the Desk Study Report. These records indicate that a closed landfill site is present bounding much of the eastern side of the site. T he records indicate the landfill was initially operated by the British Steel Corporation from 1967 until 1984. Permitted waste comprised inert and industrial waste and liquid sludge. The landfill was subsequently operated by Staffordshire County Council for household, commercial and industrial waste. It is indicated that some of the infilling included areas of water bodies. It is reported by Ove Arup and Partners (2005) the license was surrendered in 1996.
Reference should also be made to Sections 3.2 Historic Mapping. 2.16 Mining A mining report provided by the Coal Authority is presented in the Desk Study Report and is summarised as follows:
AECOM Preliminary Ground Investigation Report 17
- The report indicates that the site lies within the likely zone of influence on the surface from workings in 15 coal seams at approximately 120m to 1150m depth, the last date of working being 1982. According to the report, ground movement resulting from these past workings should now have ceased.
- There are no known coal mine entries within, or within 20m of the site boundary.
- Reserves of coal still exist in the area, which could potentially be worked in the future.
- The records do not disclose any fault or line of weakness at the surface as having affected the stability of the property. Further details of historic mining were obtained as part of an Envirocheck report from the Landmark Information Group, included in the Desk Study Report. This records the location of the Grange Colliery approximately 200m to the east of the site. A series of coal and ironstone seams are recorded as worked with operations ceasing as late as 1918. Other nearby collieries are recorded as Wolstanton and Sandbach with operations ceasing in 1924 and1917, respectively.
The Ground Motion Data Map as part of an Envirocheck report indicates that ground levels in the area are generally rising at a rate of >3.5mm year over the period of the survey. This is likely to be a result of a generally recovery of regional groundwater levels following the cessation of mining activities in the area. 2.17 Proposed Ground Model Based on the review of published geological information, previous ground investigation information and a selection of historical borehole records, a Preliminary Ground Model for the site has been prepared and is presented in Table 4.7.
Table 4.7 Preliminary Ground Model Stra tum Typical Description Anticipated Thickness (m)
Geology Made Ground Soft clay and loose/medium dense ash, brick, clinker, concrete, sandstone and pottery waste. 0 - 7 Alluvium Soft/very soft slightly sandy clay 2
Glacial Till/Highly weathered Firm to very stiff slightly silty/sandy clay with mudstone lithorelicts >3 Etruria Formation Etruria Formation (bedrock) Sandstone and mudstone c.150
Upper Coal Measures Sandstone, siltstone, mudstone, coal and ironstone c.300
Groundwater Anticipated Dep th (m) Made Ground Perched pockets within granular layers <5 Alluvium Perched pockets within granular layers <7
Etruria Formation Within sandstone bands c.<150
Upper Coal Measures Within sandstone bands and former coal workings >c.150
3 Ground Investigation
AECOM Preliminary Ground Investigation Report 19
3 Ground Investigation
3.1 Rationale And Design Philosophy The scope of the ground investigation was defined in the contract documents. The investigation layout was designed to target the infilled canal and adjacent embankment. The key objectives of the investigation were as follows:
- To provide preliminary information on the nature of the shallow soils comprising canal infill and embankment; - Recover samples of soils and or groundwater; - Provide an indication of potential contamination in the shallow soils; - Undertake in-situ and ex-situ geotechnical testing of soils;
Geotechnics Limited was appointed as the specialist site investigation contactor for the works. The ground investigation comprised a combined investigation for both geotechnical and geo-environmental purposes. The techniques used to investigate the geotechnical properties of the ground were generally in accordance with Eurocode 7: Geotechnical Design – Parts 1 and 2 (BS EN 1997-1:2004, BS EN 1997-2:2007). The investigation was designed to be a preliminary investigation for geotechnical purposes. The techniques used to investigate the contamination of ground were generally in accordance with the British Standards Institution Code of Practice for Investigation of Potentially Contaminated Sites (BS 10175:2011). The investigation was designed to be an exploratory investigation for geo-environmental purposes. The identification and description of soils in the ground investigation has been undertaken in accordance with BS EN ISO 14688- 1:2002/BS5930:2010.
The location of some exploratory holes was constrained by site access restrictions and the presence of buried services and hard obstructions.
A copy of the Factual Report is provided in Appendix A. 3.2 Summary of Fieldwork The fieldwork was carried out on 20 th April 2011. The depths of the exploratory holes, descriptions of strata encountered and comments on the groundwater conditions are given in the exploratory hole records included in the Factual Report. The Exploratory Hole Location Plan - Geotechnics drawing no Geo-PC114591-001(1) indicates the position of the exploratory holes formed. The Exploratory Hole Location Plan is included in Appendix 4 of the Factual Report. 3.2.1 Trial Pits Six trial pits, designated TP01 to TP 06, were excavated by mechanical excavator. Trial pits TP01, 02, 03 were undertaken within the footprint of the former canal channel with TP04, 05 and 06 located along the crest of the adjacent embankment. Following the completion of logging and sampling, all trial pits were backfilled with the soil arising, compacted in layers.
Trial Pit logs are included in Appendix 3 of the Factual Report. 3.2.2 Field Tests In situ hand vane tests were carried out in the cohesive strata encountered in three of the trial pits. The uncorrected results of these tests are recorded on the exploratory hole logs presented in the Factual Report 3.2.3 Sampling Strategy Geotechnical sampling and testing was conducted generally in accordance with the SISG Specification (Ref 2) and the procedures prescribed in Code of Practice for Site Investigations, BS5930:2010 (Ref 3). Additional samples for contamination testing were taken at depths instructed by the AECOM site engineer, dependant on the nature of the material encountered.
AECOM Preliminary Ground Investigation Report 20
The environmental samples of soil were either sampled from spoil heaps or directly from the excavator bucket. The samples were taken in plastic tubs, small bulk bags and amber glass jars/vials supplied by the analytical laboratory. The samples were stored on site in a cool box before transportation to the analytical laboratory. 3.2.4 Positions of Exploratory Holes The positions and ground levels of the trial pits given in the exploratory hole records were determined by conventional surveying techniques with reference to the National Grid and Ordnance Datum. 3.3 Laboratory Testing 3.3.1 Tests On Soils For Civil Engineering Purposes A programme of laboratory testing, scheduled by AECOM, was carried out on samples taken from the various strata. The geotechnical laboratory tests were carried out by Geotechnics Limited. The test procedures used were generally in accordance with the methods described in BS1377: 1990 (Ref 4). The testing schedule may be summarised as follows:
- Moisture Content (5 No.) - Atterberg Limits (5 No.) - Particle Size Distribution – Wet sieve with pipette (4 No.) Geotechnical laboratory test results are included in Appendix 5 of Factual Report. 3.3.2 Tests On Soils And Water For Environmental Pollution Assessment Purposes 3.3.2.1 Rationale For Selection Of Analytical Parameters The environmental chemistry of the ground was investigated by specialist chemical analysis, scheduled by AECOM. The range of chemical analyses scheduled includes for the likely contaminants listed in DoE Industry Profile / R&D Publication CLR 8 (Ref 5) / EA R&D Publication 66 2008 for the known previous contaminative land use history of the site. In addition it was considered prudent to analyse for a broad range of both inorganic and organic contaminants associated with more generic industrial land uses.
Whilst every effort has been made to schedule tests suitable for the known previous land use, there is no guarantee that other contaminants are not present on site for which analyses have not been carried out or which were not sampled in the programme of exploratory holes. 3.3.2.2 Soil Suite Arsenic, Cadmium, Total Chromium, Lead, Mercury, Selenium, Boron (water soluble), Copper, Nickel, Zinc, acidity (pH), Polyaromatic Hydrocarbons (PAH 16-MS), Hydrocarbons (VPH & EPH (C10-C40)) risk banded with BTEX and MTBE, Volatile and semi-volatile organic compounds and asbestos screen.
The results of chemical laboratory testing is included in Appendix 6 of the Factual Report. 3.3.2.3 Test Methods And Laboratory Accreditation The AECOM approved laboratory used for this project was Jones Environmental Laboratory, Deeside. The laboratory holds UKAS accreditation for a range of chemical and physical tests as indicated in the Factual Report. All soil test methods which are accredited under MCERTS are shown with their prefix ‘m’ on the laboratory data sheets.
4 Ground Conditions
AECOM Preliminary Ground Investigation Report 22
4 Ground Conditions
4.1 General All the exploratory holes encountered Made Ground to the full depth of exploration. This appears to confirm the expected geology near surface based on the findings of the Desk Study. 4.2 Made Ground The investigation confirmed Made Ground to a maximum depth of 3.3m. The Made Ground was found to be highly variable in nature and reference should be made to the fieldwork records for detailed descriptions of the materials encountered. The trial pits (TP01, TP02 and TP03) undertaken within the former canal channel encountered a heterogeneous material containing pieces of metal, concrete, brick and clinker to a maximum depth of 2.5m. Notably within this upper layer trial pit, TP03, recorded the presence of asbestos pipe. All three trial pits were recorded as unstable during the investigation which would suggest the canal infilling was undertaken in an uncontrolled manner with little or no compaction.
Below, a depth of 2m a layer of soft clay is recorded in trial pits TP02 and TP03 with a variety of inclusions comprising wood, ceramics, bricks, metals, clinker and coal noted in the latter excavation. A strong hydrocarbon odour is recorded within this soft layer in both aforementioned trial pits with organic material noted in TP02. It is possible that the material encountered towards the base of trial pit TP02 and TP03 was material that settled on the base of the canal channel with the hydrocarbons being deposited onto the canal base when it was breached/drained. The trial pits (TP04, TP05 and TP06) on the canal embankment encountered a heterogeneous material. All three trial pits were recorded as stable during the investigation.
A variety of inclusions are recorded within all three trial pits comprising pieces of brick, wood, metal, concrete, clinker, coal, ceramic and plastic. However these inclusions were absent within a lower layer comprising predominantly soft slightly sandy slightly gravelly silt/clay recorded in trial pits TP04 and TP06 suggesting the material to be of a reworked natural nature. Trial Pit logs are included in Appendix 3 of the Factual Report. 4.2.1 Undrained Shear Strength The undrained shear strength of the material has been determined by six field hand shear vane tests. The results ranged from 11 to 52kN/m 2. The results indicate that the material is very soft to firm. 4.2.2 Particle Size Distributions (PSD) PSD testing was undertaken on 4 bulk samples collected from the Made Ground at varying depths. 4.2.3 Natural Moisture Content Five moisture content tests were undertaken within the Made Ground at varying depths. The results indicated that the natural moisture content ranged from 11% to 50%. 4.2.4 Atterberg Tests Five Atterberg Tests were undertaken on samples collected from the Made Ground. The plastic and liquid limits ranged from 18% to 41% (average 26%) and 38% to 65% (average 50%). The plasticity index ranges from 17 to 31 (average 25). These results classify the majority of the fine material as clay of high to intermediate plasticity. The modified plasticity index, as defined in NHBC Standards, 2008 – Chapter 4.2, Building near trees, ranges from 9% to 31% which classifies the material as low to medium volume change potential.
Geotechnical laboratory test data is included in Appendix 5 of the Factual Report
AECOM Preliminary Ground Investigation Report 23
4.3 Groundwater Groundwater was encountered during fieldwork at the depths indicated in Table 4.2. Table 4.2 Summary of Groundwater Observations During Fieldwork
Trial Pit Strike Comment Stratum m bgl (m AOD) TP01 2.1 (121.94) Seepage Made Ground TP03 3.0 (120.24) Seepage Made Ground
The groundwater seepages observed in the trial pits are thought to reflect the presence of localised perched groundwater in the Made Ground. 4.4 Visual and Olfactory Evidence of Contamination Olfactory evidence of potential hydrocarbon contamination was noted in trial pits TP02 between 2.0m and 3.3m bgl and in TP03 between 2.8m and 3.0m bgl. In both locations the potentially contamination material comprised very soft or soft dark grey or black clay, which may represent the historical canal liner. Potential asbestos containing materials were encountered in TP03 comprising a fragment of cement pipe noted within made ground, composed of ‘..clay with numerous metal, concrete, medium cobble content of brick and rare asbestos pipe.’
5 Contamination Assessment
AECOM Preliminary Ground Investigation Report 25
5 Contamination Assessment
5.1 Introduction The significance of contamination concentrations on site has been assessed by identifying and assessing pollutant linkages. A pollutant linkage consists of:
- A potential source or sources of contamination. - A receptor or receptors that may be affected by the contamination. - A pathway or pathways by which they may be linked.
Contamination risks arise only where pollution linkages occur between the three components identified above. The first phase of the assessment is to identify chemicals that are preent at significant concentrations in the soil. Where concentrations are in excess of their values, a qualitative risk assessment may be undertaken. A conceptual site model (CSM) and preliminary assessment of plausible pollutant linkages was completed as part of the Desk Study Report (ref. 1). 5.2 Summary of Plausible Pollutant Linkages The potential sources, pathways and receptors identified from the Desk Study Report are provided below: 5.2.1 Potential Sources of Contamination Historical Ordnance Survey maps of the area reveal that the site was formerly occupied by the Burslem Branch of the Trent and Mersey Canal which was subsequently backfilled in the early 1960s. From the information reviewed, the fill material is likely to comprise made ground of variable composition including demolition materials such as bricks, tarmac, asbestos material and general refuse. The made ground on the site is considered to be a potential source of contamination.
The base of the canal may also contain organic material that may have silted up prior to being abandoned. The refuse and slag heaps along the western boundary of the site also forms a potential source of contamination. Significant fly tipping of material in the vicinity of the site is also considered to be a potential source of contamination. Historical and current off site land uses, which include various forms of industrial works and the historical landfill in the south east of the site forms potential sources of contamination on the site. It is unknown if the landfill in the vicinity of the site was properly engineered and sealed. Accordingly, there are potential risks of leachate migration from the landfill to the site. There is also potential risk of gases generated within the landfill to migrate to the site.
The existing waste management operations to the east of the site which includes waste sorting and stockpiling activities also forms a potential source of contamination on the site.
Potential contaminants associated with identified historical and current uses of the site and the surrounding include:
- Petroleum hydrocarbons - Polycyclic aromatic hydrocarbons (PAH’s) - Phenols - Heavy Metals and - Asbestos 5.2.2 Potential Pathways for Contaminant Migration The following potential migration pathways have been identified:
- Dermal contact with / Ingestion / Inhalation / of soils, dusts or liquids; - Leaching of contamination within the made ground and migration to controlled waters - Migration of aqueous phase contamination via made ground and permeable natural strata; - Migration of aqueous phase contamination via the underlying groundwater to offsite receptors; - Inhalation of hazardous gases in confined spaces; - Plant uptake of bio-available contamination in soils.
AECOM Preliminary Ground Investigation Report 26
5.2.3 Receptors It is proposed that the canal waterway will be restored and the development area will include associated public amenity areas. The potential receptors concerning the construction period, or after the completion of the proposed developments are as follows:
- Existing and future site users; - Demolition, construction and maintenance workers; - Adjacent site users; - Groundwater; - Surface water; - Proposed planting; - Structures. Given the limitations of this preliminary investigation potential impacts on controlled waters and off site receptors have not been considered as part of this assessment. 5.3 Soil Results 5.3.1 Hazard Identification Chemical analyses have been performed on a total of 12 no. soil samples, including 9 samples of granular Made Ground, 3 samples of cohesive made ground, which may comprise the historical canal liner, down to a maximum depth of 2.5m below existing ground level. The geochemical test results are summarised in Appendix B. 5.3.2 Assessment Approach It is understood that the proposed development will comprise a restored canal arm and associated amenities as shown on the Proposed Scheme Layout presented as Figure 1. An initial appraisal of the scheme suggests that for much of the length the channel will be formed with trapezoidal butyl liner with, hard edging where moorings are proposed, or where space constraints required. A preliminary design brief for the scheme is included in Appendix C for information. A maximum water level of 124.305m OD is proposed at this stage with coping level of 124.655m OD. The recent topographic survey indicates that ground levels currently range from around 123m OD at the central section to a maximum of around 124.5m OD at the northern end, suggesting that ground levels will need to be raised by up to over 1.5m. It is generally considered that any contamination present at a depth of greater than 0.6 / 1m is unlikely to pose a significant risk to human health via direct contact and therefore only the soil sample results obtained from the top 0.6 / 1m of the site are considered. However, the construction proposals may involve significant excavation and movement of material, which may result in potentially contaminated materials being exposed at the surface. For this reason consideration has been given to analysis results for samples taken at all levels. Due to the heterogeneity of the ground conditions and the limited number of samples tested, averaging areas have not been considered and all sampling locations have been assessed separately. The potential chronic risks to human health have been assessed by comparing the recorded concentrations of contaminants against AECOM generic Assessment Criteria (AGAC), as an initial screen.
The AGAC have been derived using the published CLEA methodology and toxicological and physiochemical input parameters from published Soil Guideline Values (SGVs and, in their absence, CIEH/LQM GAC (Generic Assessment Criteria for Human Health Risk Assessment, Chartered Institute of Environmental Health and Land Quality Management, 2009). Following redevelopment the site will be used for public amenity. Therefore, the significance of soil contamination in relation to human health has been assessed in accordance with the AGAC derived for a residential end use, without home grown produce. A mean Soil Organic Matter (SOM) Content of 1% has been assumed in the absence of site specific data. This is a conservative assumption.
AECOM Preliminary Ground Investigation Report 27
Whilst this assessment end use is considered highly conservative given the final proposed endues it is considered acceptable as an initial screen to assess potential risks at this preliminary assessment stage. If the development proposal changes then this risk assessment may need to be revised. Details of the assessment criteria and modelling assumptions are provided in Appendix D. The potential risk driver for asbestos in soil is via inhalation of fibres. Dermal contact and to a lesser degree ingestion are not of concern, however all contact with potential asbestos containing materials (ACM) should be minimised wherever possible. Guidance on the classification of waste contaminated by Asbestos is covered in the following documents:
- Environment Agency Document Hazardous Waste: Interpretation of the definition and classification of hazardous waste, WM2 version 2.2. - Environment Agency Guide, Hazardous Waste, Asbestos and Contaminated Waste. 5.3.3 Discussion of Results 5.3.3.1 Future Site Users Those contaminants which were recorded above the accredited limit of detection were compared against the selected AGAC. The table below shows the contaminants concentrations which were detected in excess of their respective AGAC. Table 5.1: soil results in excess of AGAC
Minimum Maximum Screening Value Determinand Locations Where Above Detection (mg/kg) Arsenic 7.5 42.7 35 TP05: 0.3m TP01: 0.5m, TP01:1.9m, TP02; 0.3m, TP02;3.0m, TP03; 0.35m, TP03; 2.1m, TP04; Chromium 9.7 519.4 4.2 0.4m, TP04; 2.5m, TP05; 0.3m, TP05; 2.0m, TP06; 0.25m, TP06; 1.5m Lead 22 595 450 TP01; 0.5m Benzo[a]pyrene <0.4 1.33 1.0 TP02; 3.0m 4-Methylphenol <10 63 10 TP04; 2.5m TP01: 0.5m , TP02;3.0m, TP03; 2.1m, TP04; 33 1025 10 2-Methylnaphthalene 2.5m, TP05; 2.0m, TP06; 1.5m TP01: 0.5m, TP02;3.0m, TP03; 2.1m, TP04; 10 140 10 Carbozole 2.5m, TP05; 2.0m TP01: 0.5m, TP02;3.0m, TP03; 2.1m, TP04; 17 722 10 dibenzofurane 2.5m, TP05; 2.0m, TP06; 1.5m The recorded concentrations were below the AGAC for all other deterinands. 5.3.3.2 Landscaping Areas and Plant Growth Guidance on the effects of metal contamination on plant growth is provided within the Ministry of Agriculture, Fisheries and Food (MAFF) Code of Good Agricultural Practice for the Protection of Soil (The Soil Code). The results of the chemical analysis indicated that concentrations of phytotoxic contaminants lead and zinc exceeded threshold values in samples taken from TP01 at 0.5m and TP06 at 0.25m.
It is therefore considered that the soils generally pose a potential risk to plants and trees.
AECOM Preliminary Ground Investigation Report 28
5.4 Significance of Contamination The following assessment is based on the limited number of sample data obtained from the investigation. The dataset is not considered adequate to provide a robust assessment of the ground conditions across the site and as such this should be considered as a preliminary assessment and subject to confirmation by subsequent phases of detailed ground investigation. 5.4.1 Hazards to Human Health – Long Term Risks to Future Users Arsenic was recorded above the screening value in one sample of Made Ground, which included demolition rubble and clinker. Chromium was recorded above the selected screening values across the entire site. Chromium generally exists in two valence states, Chromium (III) and the more toxic Chromium (VI). Chromium (III) is a naturally occurring essential element although its presence is often associated with industries such as plating and dye works. Chromium (VI) is most commonly produced by industrial processes. For the purpose of this assessment, the worst case scenario screening level for Chromium has been selected, which is chromium (VI) via the inhalation pathway. It is highly unlikely that recovered soil samples contain only chromium (VI) and it is more rational to assume that Chromium (III) is the prevailing valence state and when the recorded concentrations are compared to the less stringent Chromium (III) screening value of 3000mg/kg there are no exceedences. On this basis it is considered unlikely that chromium presents chronic risk to future site users; however, further sampling and analysis would be required to confirm this. The concentration of lead was recorded above the selected screening values in one sample of Made Ground from TP01 at 0.5m. The concentration of benzo[a]pyrene was in excess of the selected screening value in one sample of cohesive Made Ground from TP02 at 3.0m. The sample comprised soft dark grey organic clay with a hydrocarbon odour and may represent the historical canal liner. Concentrations of the semi-volatile organic compounds 4-Methylphenol, 2-Methylnaphthalene, Carbozole and dibenzofurane were found at concentrations in excess of the laboratory limit of detection in the majority of samples tested. No AGAC have been derived for these compounds. 5.4.2 Hazards to Human Health – Construction Workers It is considered that the site poses a low acute risk of harm to construction workers working in the proposed development area.
For protection of construction workers the following minimum control measures should be adopted during development and be incorporated in the Construction Health and Safety Plan for the proposed works:
- All workers engaged in earthworks and working in trenches/excavations should minimise physical contact with the soil and be rigorous in matters of personal hygiene;
- All workers should adhere to normal site practice and employ appropriate personal protective equipment (PPE) to minimise direct contact with soils and inhalation of dust generated during the handling of the excavated material; and
- Exposed and stockpiled material should be either covered or keep damp to minimise the generation and dispersion of dust, which may potentially impact receptors outside the working area.
In addition to the above, works should cease and appropriate control measures should be implemented if evidence of gross contamination is encountered during the works that was not encountered during the ground investigation.
Confined spaces entry control measures should be implemented for any construction worker entering trenches and confined spaces during the construction works. 5.4.3 Hazards to Plants and vegetation The recorded concentrations of phytotoxic compounds lead, and zinc within the Made Ground may affect the growth of some plants. Consideration should be given to the use of resistant species in proposed planting schemes.
AECOM Preliminary Ground Investigation Report 29
5.4.4 Hazards to the Fabric of Buildings, Structures and Services Elevated concentrations of some potential contaminants have been detected on site. Consideration should be given to the presence of these substances in the selection of building materials and services. Acidity (pH) - Extremes of pH represent a corrosive risk to materials and also act as an activator to other chemical reactions. Sulphate - The presence of sulphate can have a deleterious effect on concrete. Hydrocarbons - It is possible that elevated concentrations of such compounds can react with certain organic compounds used in building materials and services. Therefore it is recommended that any new materials used on site be designed accordingly. 5.5 Waste Classification If arisings from the constructions works are intended for disposal then there is a requirement to determine prior to disposal whether these would classify as:
- Hazardous - Non hazardous - Inert
A preliminary assessment of the chemical data has been undertaken with respect to Technical Guidance WM2, Environment Agency et al, 2008 (ref 6) to determine whether arisings from the site, intended for disposal to landfill, posses hazardous properties and therefore would require disposal to a hazardous landfill or an alternative facility that deals with designated Hazardous Waste.
A preliminary assessment considered the concentrations of TPH in the samples. In one sample TP02; 3.0m comprising soft organic clay with hydrocarbon odour the concentration of TPH exceed the generic threshold of 1,000mg/kg.
Potential asbestos containing material was encountered in the made ground in TP03 between GL and 2.0m. Based on these findings, waste arisings generated from the Made Ground during construction locally potentially classify as Hazardous Waste although the majority of material is likely to classify as Non-hazardous.
This preliminary assessment for initial screening purposes considers the chemical data available but some hazardous properties, such as those pertaining to the physical nature of the material, can be determined only by further testing prior to disposal, there may be a need to fulfil this requirement. It is recommended that full assessment of waste classification be carried out as part of the detailed ground investigation confirm disposal requirements with prospective landfill operators prior to generating the arisings for disposal. 5.6 Waste Disposal The Landfill Directive, introduced to the UK via the Landfill Regulations (England and Wales) 2002 aims to reduce reliance on landfill as a disposal option. The Regulations include updated Waste Acceptance Criteria (WAC) as limit values for waste destined to various classes of landfill. The developer has a statutory responsibility under the Duty of Care Regulations of the Environmental Protection Act 1990 to ensure that contaminated soil and water is disposed of off-site to a suitably licensed waste management facility in a safe and approved manner.
To comply with the Duty of Care all wastes taken off site, in solid or liquid form, must be handled by a registered waste carrier and be accompanied by a consignment note that describes the waste. 5.7 Waste Re-Use Material excavated during the construction of cuttings will, where possible, be re-used in the construction of embankments, environmental bunds and landscape areas, in order to reduce the amount of new material brought onto site and the amount of waste material to be sent to landfill.
AECOM Preliminary Ground Investigation Report 30
It is anticipated that materials arising from the scheme will comprise mostly granular Made Ground It is therefore concluded that, subject to compliance with geotechnical and geotechnical parameters, some of the materials may be suitable for potential reuse. Locally soft or very soft clays were encountered, which are considered to represent the historical canal liner. These materials are unlikely to be suitable for reuse without treatment. The management of waste is regulated by The Environmental Permitting Regulations. As such, there is a statutory duty on the waste producer to comply with the interpretation of waste operations exempt from Environmental Permitting. If any excavated deposits are proposed to be re-used on site then it may be necessary to register this activity as an exempt activity under the Environmental Permitting Regulations. If the material is classified as ‘Hazardous Waste’ under the Hazardous Waste Regulations (2005) then an exemption is unlikely to be granted unless it can be demonstrated that it meets the Site- Specific Remedial Assessment Criteria (refer to Section 5.2). Any earthworks activities, or on-site re-use of crushed arisings, may also require an exemption under the Environmental Permitting Regulations, previously known as the Waste Management Regulations.
6 Foundations and Ground Engineering
AECOM Preliminary Ground Investigation Report 32
6 Foundations and Ground Engineering
6.1 Introduction The following section is based on information reported previously in the Geotechnical and Geo-environmental Desk Study Report (ref 1) and updated where appropriate following the limited ground investigation. 6.2 Details of the Development It is understood that the development is to comprise the restoration of the Burslem branch of the Trent and Mersey Canal. The current proposals are illustrated in Figure 1. The development of the site is anticipated to require the following stages:
- Assessment and/or stabilisation of existing earthworks and retaining wall(s) - Excavation and construction of canal channel; - Construction of towpaths, moorings, footbridge and access roads. 6.3 Geotechnical Hazards The anticipated ground conditions beneath the site are discussed in Section 2 supplemented by the findings of the ground investigation discussed in Section 4. A summary of commonly occurring ground-related hazards, excluding ground contamination, is given in Table 6.2. The hazards identified as being potentially present on site could have potential implications on ground engineering design.
Table 6.2: Summary of Potential Geotechnical Hazards
Geotechnical Hazard category (excluding Probability Engineering Implications contamination issues) Lateral changes in ground conditions High Differential settlement of earthworks/sub -structures.
Highly compressible / low bearing capacity soils High Unacceptable total and di fferential settlement. Ground subject to or at risk from landslides Medium / High Stabilisation measures to existing embankment/cutting slopes Ground subject to or at risk from river erosion Medium Protection of embankment toe High groundwater table / a nd/or flooding (including Medium Inundation of excavations, instability of excavations waterlogged ground) Underground coal mining Low / medium Ground movement due to underground mining is likely to have ceased. However, due to the magnitude of subsidence that has occurred historically some residual ground movement may be anticipated Existing sub -structures (e.g. original canal walls) High Obstructions during excavation and construction of walls Filled and Made Ground (e.g. to former canal channel) Hig h Obstructions during excavation and construction of walls Variable and unpredictable ground conditions Adverse ground chemistry (including expansive slags Medium Attack of concrete/steel sub structures requiring appropriate material and weathering of sulphides to sulphates) design Unexploded ordnance Low Watching brief during excavation and driving. Unstable existing retaining walls Low /medium Stabilisation/replacement measures
6.4 Earthworks and slopes It is unlikely that the historical earthworks on site will comply with current design standards. Given the proximity of the existing embankment and cutting slopes to the canal, likely poor original method of construction and the history of increasing the height of the earthworks in order to counteract mining subsidence, it is expected that some form of stabilisation or re-grading of the slopes will be necessary.
AECOM Preliminary Ground Investigation Report 33
Any form of stabilisation/augmentation will need to consider the site boundary constraints such as watercourse, former landfill, adjacent properties and available land. Similar considerations will be required for any new earthworks proposed or modifications to existing earthwork as a result of route alignment changes. Consideration should be given to the affects of vibration and temporary surcharge loads imposed by the construction works, which may affect the stability of adjacent structures, buildings and earthworks. 6.5 Foundations The Made Ground on site is highly variable with unpredictable engineering properties and; therefore total and differential settlement may be unpredictable and excessive without some form of ground treatment. Alternatively, structural loads may be transferred to competent geology present at depth using some form of driven or bored pile. 6.6 Retaining Walls The existing canal walls evident on site should be inspected by a suitably qualifies structural engineer where they are proposed to remain. The retaining walls appear to be in a poor state of repair locally and are likely to require remediation or replacement. 6.7 Excavations Excavations are likely to be unstable in the made ground and natural ground and full support should be anticipated. Pockets of perched water are anticipated within the fill which could result in ingress and instability of the excavation. Similar conditions are likely in the natural alluvial soils where granular layers are encountered and groundwater control measures should be considered. However, regional groundwater is likely to be below the base of the proposed canal; therefore uplift/buoyancy of the liner is unlikely to be an issue.
7 Recommendations for Further Works
AECOM Preliminary Ground Investigation Report 35
7 Recommendations for Further Works
Based on the findings of the geo-environmental and geotechnical assessments, set out in Sections 5 and 6 respectively, it is considered necessary to carry out further intrusive ground investigation and appraisal work to inform the detailed scheme design. Further intrusive ground investigation to address the engineering issues will be required. An indicative scheme is presented in Figure 3 and comprises the following items:
- Boreholes formed by cable percussive (and rotary methods where appropriate) sunk to intercept the solid geology and groundwater, distributed at 50m centres along the proposed alignment of the canal. - Boreholes at the crest of significant adjoining earthworks and at the proposed footbridge replacement and mooring area; - Additional exploratory holes to target specific sources of potential contamination. - Standpipes and piezometers to be installed to monitor gas and groundwater levels; - Trial pits and observation pits to examine existing foundations to adjoining structures, existing retaining walls and locate services.
By undertaking an intrusive ground investigation, an assessment of the ground and groundwater profiles may be carried out and the geotechnical and geo-environmental risks associated with the site made. The investigation will allow a quantitative assessment as to whether any of the potential risks identified in this study are present and are of material concern to the development and form the basis for engineering design.
A detailed inspection of on-site and adjacent structure by an experienced structural engineer is recommended. Structural cores will also be required where retaining walls are to be assessed for re-use
8 References
AECOM Preliminary Ground Investigation Report 37
8 References
1. AECOM, 2011. Geotechnical and Geoenvironmental Desk Study Report – Burslem Port 60140243/029/GEO/01/- 2. Site Investigation Steering Group, 1993. Specification for ground investigation. Thomas Telford, London 3. British Standards Institution, 2010. BS5930, 2010, Code of Practice for Site Investigations. BSI, London 4. British Standards Institution, 1990. BS1377-2:1990. Methods of test for soils for civil engineering purposes – Classification Tests. BSI, London. 5. Environment Agency (2002) CLR8: Potential Contaminants for the Assessment of Land ;
6. Environment Agency (2006) EA Hazardous Waste Interpretation of the definition and classification of hazardous waste Technical Guidance WM2 (Version 2.1 October 2006); 7. The Landfill (England and Wales) Regulations 2002, The Stationary Office, London
Figures
AECOM Preliminary Ground Investigation Report
Figures
Figure 1 Proposed Scheme Layout Figure 2 Site Location Plan Figure 3 Proposed Ground Investigation Plan
"This document has been prepared by AECOM Ltd ("AL") for the sole use of our Client (the "Client") and in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AL and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AL, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AL"
Rev Date Detail Made Chk'd App'd
Client:
STOKE-ON-TRENT CITY COUNCIL
Project:
BURSLEM PORT DRG Path: C:\DOCUME~1\CONNEL~1\LOCALS~1\Temp\AcPublish_5064\Figure 1 - Proposed Scheme Layout.dwg User: connellym Plot time: 20-05-11 @ 4:47pm
Title: cm PROPOSED SCHEME LAYOUT
Design: PJ CAD: MC
Chk'd: DS App'd: DS
Date: APRIL 2011 Scale: NTS
14 Queen Victoria Road Tel: +44 (0) 24 7625 3300 Coventry Fax: +44 (0) 24 7625 3301 CV1 3PJ www.aecom.com
Rev: No. FIGURE 1
cm A3 "This document has been prepared by AECOM Ltd ("AL") for the sole use of our Client (the "Client") and in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AL and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AL, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AL" DRG Path: C:\DOCUME~1\CONNEL~1\LOCALS~1\Temp\AcPublish_5064\Figure 2 - Location Plan.dwg User: connellym Plot time: 20-05-11 @ 4:48pm cm
This drawing includes Ordnance Survey material with the permission of Ordnance Survey on behalf of The Controller 14 Queen Victoria Road Tel: +44 (0) 24 7625 3300 of Her Majesty's Stationery Office, © Crown Copyright Coventry Fax: +44 (0) 24 7625 3301 AECOM Limited, Licence Number AL100019139 CV1 3PJ www.aecom.com
Client: Title: Design: PJ CAD: MC STOKE-ON-TRENT Chk'd: DS App'd: DS CITY COUNCIL LOCATION PLAN Project: Date: APRIL 2011 Scale: NTS BURSLEM PORT Rev: No.FIGURE 2 cm A4 "This document has been prepared by AECOM Ltd ("AL") for the sole use of our Client (the "Client") and in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AL and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AL, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AL"
NOTES
GROUND INVESTIGATION KEY
BH BOREHOLE
TRIAL PIT TP
Rev Date Detail Made Chk'd App'd
Client:
Stoke-On-Trent City Council
Project:
Burslem Port
Title: Proposed Main Ground Investigation Plan
Design: DCS CAD: MC
Chk'd: App'd:
Date: June 2011 Scale: 1:1000 @ A1
This map is reproduced from the Ordnance Survey material 14 Queen Victoria Road Tel: +44 (0) 24 7625 3300 with the permission of Ordnance Survey on behalf of the Coventry Fax: +44 (0) 24 7625 3301 Controller of Her Majesty's Stationery Office © Crown Copyright. CV1 3PJ www.aecom.com Unauthorised reproduction infringes Crown copyright and may Rev: lead to prosecution or civil proceedings. No. Figure 3 - Stoke-on-Trent City Council Licence Number: 100024286 2011 cm A1 Appendices
Appendix A – Geotechnics Factual Report
Ground Investigation at
BURSLEM PORT, Stoke on Trent
Factual Report
for Stoke on Trent City Council
Engineer : AECOM LIMITED
OS License Number : 100020449
Project Number : PC114591
May 2011 Issuing office :
Head Office Coventry
Geotechnics Limited North West Office South West Office The Geotechnical Centre Geotechnics Limited Geotechnics Limited 203 Torrington Avenue The Geotechnical Centre The Geotechnical Centre Unit 1, Borders Industrial Park 7 Pinbrook Units Tile Hill River Lane, Saltney Venny Bridge Coventry Chester Exeter CV4 9AP CH4 8RJ EX4 8JQ T: 01244 671 117 T: 01392 463 110 T: 024 7669 4664 F: 01244 671 122 F:01392 463 111 F: 024 7669 4642 [email protected] [email protected] [email protected]
Geotechnics Limited, Registered in England No. 1757790 at The Geotechnical Centre, 203 Torrington Avenue, Tile Hill, Coventry CV4 9AP
Ground Investigation Factual Report at
BURSLEM PORT, Stoke on Trent for Stoke on Trent City Council
Engineer : Project No: AECOM LIMITED PC114591 May 2011
LIST OF CONTENTS
Page No CONTENTS
1.0 INTRODUCTION 1
2.0 OBJECT AND SCOPE OF THE INVESTIGATION 1
3.0 PRESENTATION 1
4.0 THE SITE 1 4.1 Location 1 4.2 Description 1
5.0 PROCEDURE 2 5.1 Commissioning 2 5.2 General 2 5.3 Trial Pits 2
6.0 LABORATORY TESTING 2 6.1 Geotechnical 2 6.2 Contamination 2
APPENDICES
APPENDIX 1 The Brief APPENDICES APPENDIX 2 Site Location Plan
APPENDIX 3 Trial Pit Records
APPENDIX 4 Exploratory Hole Location Plan
APPENDIX 5 Laboratory Test Results - Geotechnical
APPENDIX 6 Laboratory Test Results - Contamination (Soil)
APPENDIX 7 Investigation Techniques and General Notes
Ground Investigation Factual Report at
BURSLEM PORT Project No : PC114591 Stoke on Trent May 2011
1.0 INTRODUCTION 4.0 THE SITE
A geotechnical and environmental investigation was 4.1 Location undertaken by Geotechnics Ltd at the site of a proposed regeneration of the area including The site is located approximately 1.9km east of the reinstating the currently in-filled canal spur located in A500 and 4km north of the centre of Stoke on Burslem Port, Stoke on Trent. The investigation was Trent. The approximate Ordnance Survey National carried out to the instructions of Aecom Limited, Grid Reference for the site is SJ 866 489 and an the Engineer, on behalf of the Client, Stoke on Trent extract from the relevant 1:50,000 Scale O.S. Map City Council. This report describes the work (Sheet No.118) is included as Appendix 2. undertaken and presents the data obtained. 4.2 Description 2.0 OBJECT AND SCOPE OF THE INVESTIGATION The site is approximately rectangular in shape and covers an area of about 3.24 hectares.
The object of the investigation was to obtain The site comprises two separate areas of information on the ground and groundwater investigation. conditions relating to the design of the proposed The first is generally flat with overgrown grasses and works within the limitations posed by trial hole vegetation along its length, ground conditions were numbers, locations, depths, methods adopted and firm and there were some areas of concrete and the scope of approved in situ and laboratory testing. asphalt, other than the original canal retaining walls The Brief for the project is included in Appendix 1. still visible in the ground. It is bounded to the south The investigation comprised several trial pits, in situ by the Mersey Canal and to the west by the and laboratory testing and reporting. currently occupied commercial units. Further along there is a derelict factory and some 3.0 PRESENTATION residential housing situated on East View. Along the eastern boundary there is a linear depression A description of the site and a summary of the possibly a drainage channel associated with the procedures followed during the investigation process adjacent refuse tip. It runs in a north to south are presented in Sections 4 to 6. The factual data so direction for approximately 270m where it meets obtained are presented in Appendix 3 to 6 of this with a pond. Access to this part of the site was via report. East View, off of Lukes Street and Dimsdale Street.
In addition, the report is presented in electronic The second part of the site is located north of the PDF format separately on disk. footbridge running west to east from Dimsdale Street to Navigation Road. The site was located in Attention is drawn to the General Notes and an occupied commercial warehouse compound, with Investigation Procedures presented in Appendix 7 to access from Navigation Road. Ground conditions aid an understanding of the procedures followed and were firm, and the majority of this part of the site the context in which the report should be read. was concreted, with an area of loose bark chippings and scrub vegetation located on its western boundary. Along this western boundary was a steep slope and retaining wall associated with residential properties. The site was bounded on the north, south and east by commercial or industrial units.
Geotechnics Limited BURSLEM PORT, Stoke on Trent The Geotechnical Centre, Factual Report, Project No PC114591, May 2011. 203 Torrington Avenue, Tile Hill, Coventry. CV4 9AP Page 1 of 3
5.0 PROCEDURE 6.0 LABORATORY TESTING
5.1 Commissioning 6.1 Geotechnical
The work was awarded following submission of a The laboratory testing schedule was formulated by proposal for ground investigation of the site in the Engineer in order to relate to the proposed accordance with the Client’s requirements (see development. The tests, where appropriate, conform Appendix 1). to BS 1377 - Methods of Test for Soils for Civil Engineering Purposes (1990) and were carried out in 5.2 General Geotechnics Limited's UKAS accredited Laboratory (Testing No. 1365). Any descriptions, opinions and The procedures followed in this site investigation are interpretations are outside the scope of UKAS based on BS 5930:1999 + A2:2010 - Code of Practice accreditation. for Site Investigations and BS 10175 (2011) – Investigation of Potentially Contaminated Sites. The soils The tests undertaken can be summarised as follows:- and rocks encountered have been described in accordance with BS5930:1999 + A2:2010 and BS EN BS 1377 (1990) ISO 14688-1:2002 and BS EN ISO 14689-1:2003. Test No. Test Description The Trial Pit Records are included in Appendix 3 and their approximate positions are shown on the Part 2 Exploratory Hole Location Plan in Appendix 4. 3.2 5 No. Moisture Content Determination The Exploratory Hole locations were selected by Aecom Limited, the Engineer. Levels shown on the 4.3 & 5.3 5 No. Liquid and Plastic Limit Exploratory Hole Records are related to Ordnance Determination Datum and the co-ordinates to OS National Grid and were obtained using a Leica Viva Net Rover base 9.2 & 9.3 4 No. Mechanical Analysis - Sieving station. The depths quoted are in metres below ground level. 9.4 3 No. Mechanical Analysis - Sedimentation 5.3 Trial Pits The results of these tests are presented in Appendix 5. Six (6 No.) Trial Pits numbered TP01 to TP06 were excavated to depths varying between 2.50m and 3.30mm below ground level using a JCB 3CX 6.2 Contamination excavator on the 20th April 2011. This work was supervised on site by a geotechnical engineer. Selected samples of soil, were tested in at the The profiles of strata or other features were laboratories of Jones Environmental Laboratories for recorded as excavation proceeded and a number of determinands in order to check on measurements taken from ground level. Pits were potential site contamination. The determinands were entered where safe to do so to allow in situ specified by the Engineer. measurement of strata conditions. Representative samples were taken, where appropriate, for Soil laboratory examination and analysis and in addition, Soil samples were tested for the following Environmental samples (E) were recovered at the determinands:- depths indicated on the Trial Pit Records. At depths Arsenic in excess of 1.20m below ground level or in unstable Cadmium conditions, samples were taken directly from Total Chromium excavated materials deposited at surface. Lead Groundwater observations and trench stability notes Mercury are included on the Trial Pit Records. Selenium Copper Nickel
Geotechnics Limited BURSLEM PORT, Stoke on Trent The Geotechnical Centre, Factual Report, Project No PC114591, May 2011. 203 Torrington Avenue, Tile Hill, Coventry. CV4 9AP Page 2 of 3
Zinc Signed for and on behalf of Geotechnics Limited. pH Total Polyaromatic Hydrocarbons Total Petroleum Hydrocarbons Asbestos Screen
Volatile Organic Compounds (VOC) Semi-Volatile Organic Compounds (SVOC) P Stojanovic BSc, BA ,FGS, Affil. IFA The results are presented in Appendix 6. Engineer
D R Bracegirdle BSc,MSc,CEng,FIMM,MHKIE,CGeol,FGS. Principal Engineer
Geotechnics Limited BURSLEM PORT, Stoke on Trent The Geotechnical Centre, Factual Report, Project No PC114591, May 2011. 203 Torrington Avenue, Tile Hill, Coventry. CV4 9AP Page 3 of 3 1
APPENDIX 1
The Brief
2
APPENDIX 2
Site Location Plan SITE LOCATION PLAN
© Crown Copyright Reserved, OS License Number: 100020449
Ground Investigation at BURSLEM PORT, Stoke on Trent for Stoke on Trent City Council 3
APPENDIX 3
Trial Pit Records DATA SHEET - Symbols and Abbreviations used on Records Sample Types Groundwater Strata, Continued
B Bulk disturbed sample Water Strike Mudstone BLK Block sample Depth Water Rose To C Core sample Instrumentation D Small disturbed sample Siltstone (tub/jar)
E Environmental test sample
ES Environmental soil sample Seal Metamorphic Rock EW Environmental water sample Fine Grained G Gas sample
L Liner sample Filter Medium Grained P Piston sample (PF - failed P sample) Coarse Grained TW Thin walled push in sample
U Open Tube - 102mm Seal diameter with blows to Igneous Rock take sample. (UF - failed U sample) Fine Grained UT Thin wall open drive tube Strata sampler - 102mm diameter
with blows to take sample. Medium Grained (UTF - failed UT sample) Made Ground Type 1
V Vial sample Coarse Grained W Water sample Type 2
# Sample Not Recovered Backfill Materials Topsoil Insitu Testing / Properties Arisings S Standard Penetration Test (SPT) Cobbles and Boulders
C SPT with cone Bentonite Seal
VN Strength from Insitu Vane Gravel
HV Strength from Hand Vane Concrete Sand PP Strength from Pocket Penetrometer
(All other strengths from undrained Fine Gravel Filter triaxial testing) Silt w% Water content General Fill N SPT Result Clay
-/- Blows/penetration (mm) after seating drive Gravel Filter Peat -*/- Total blows/penetration (mm) Grout ( ) Extrapolated value Note: Composite soil types shown by combined symbols
Rotary Core Chalk Sand Filter
RQD Rock Quality Designation (% of intact core >100mm) Limestone Tarmacadam FRACTURE INDEX Fractures/metre
FRACTURE Maximum Sandstone SPACING (mm) Minimum NI Non-intact core NR No core recovery (where core recovery is unknown it is Coal assumed to be at the base of the run)
Form REP002 Rev 1 TRIAL PIT RECORD Trial Pit Project BURSLEM PORT, STOKE-ON-TRENT Engineer AECOM LIMITED Trial Pit 01 Project No PC114591 National Grid 386498.076 E Client AECOM LIMITED Coordinates 349236.751 N Ground Level 124.04 m OD Samples and Tests Strata Scale 1:50 Level Depth Type Stratum Results Description Depth Legend No m OD G.L. 124.04 Wood chippings 1 [MADE GROUND] 0.20 123.84 0.40 D Brown sandy gravel with occasional concrete and 2 0.50 E numerous rootlets. Gravel is sub angular to angular, fine to coarse clinker. 0.75 123.29 [MADE GROUND] 1.10 D mc=11% Soft grey slightly clayey silty very gravelly SAND. Gravel is sub angular to tabular, fine to medium siltstone/mudstone. 1.50- 2.00 B 3
1.90 E
2.50 D 2.50 121.54 End of Excavation
Excavation Groundwater Plant CAT 428D Width (B) 0.60 Depth Depth Details Date 20/04/2011 Length (C) 3.40 Observed of Pit Shoring None. 2.10 Seepage Date Backfilled 20/04/2011 Stability Unstable during excavation.
Remarks E sample = 1 x vial, 1 x plastic jar and 1 amber jar Logged by PST Trial Pit was reinstated with arisings on completion. Checked by DRB Symbols and Figure 1 of 1 abbreviations are 03/06/2011 explained on the accompanying key sheet. All dimensions are in metres. Logged in accordance with BS5930:1999 + A2:2010 TRIAL PIT RECORD Trial Pit Project BURSLEM PORT, STOKE-ON-TRENT Engineer AECOM LIMITED Trial Pit 02 Project No PC114591 National Grid 386546.189 E Client AECOM LIMITED Coordinates 349134.374 N Ground Level 123.59 m OD Samples and Tests Strata Scale 1:50 Level Depth Type Stratum Results Description Depth Legend No m OD G.L. 123.59 Grass over brown slightly sandy gravelly clay. Gravel is sub angular to angular fine to coarse clinker. 0.30 D [MADE GROUND] 1 0.30 E 0.40- 0.90 B 0.60 122.99 Brown and dark grey slightly clayey very sandy gravel with a low cobble content of brick and concrete. Gravel is sub angular to angular, fine to coarse clinker. [MADE GROUND] 2 1.50 D
2.00- 2.40 B 2.00 121.59 2.10 HV Av=11kPa Very soft dark grey/black organic slightly gravelly 2.20 E clay with a strong hydrocarbon odour. Gravel is sub angular to sub rounded siliceous material. [POSSIBLE MADE GROUND] 3
3.00 E 3.20 HV Av=11kPa 3.30 D mc=50% 3.30 120.29 End of Excavation
Excavation Groundwater Plant CAT 428D Width (B) 0.60 Depth Depth Details Date 20/04/2011 Length (C) 2.40 Observed of Pit Shoring None. None encountered during excavation Date Backfilled 20/04/2011 Stability Unstable during excavation.
Remarks E sample = 1 x vial, 1 x plastic jar and 1 amber jar Logged by PST Hand Vane Tests were carried out in situ on intact pieces brought to the surface in the Checked by DRB Symbols and bucket of the excavator. Figure 1 of 1 abbreviations are Trial Pit was reinstated with arisings on completion. 03/06/2011 explained on the accompanying key sheet. All dimensions are in metres. Logged in accordance with BS5930:1999 + A2:2010 TRIAL PIT RECORD Trial Pit Project BURSLEM PORT, STOKE-ON-TRENT Engineer AECOM LIMITED Trial Pit 03 Project No PC114591 National Grid 386558.976 E Client AECOM LIMITED Coordinates 349026.403 N Ground Level 123.24 m OD Samples and Tests Strata Scale 1:50 Level Depth Type Stratum Results Description Depth Legend No m OD G.L. 123.24 Grass over brown slightly sandy gravelly clay with numerous metal, concrete, medium cobble content of 0.35 D brick and rare asbestos pipe. Gravel is sub angular 0.35 E to angular, fine to coarse brick shards and clinker. 0.50 B [MADE GROUND] 0.50 D 0.50 E 0.80- 1.10 B 1
1.50 D mc=25% 1.50 E
2.00 121.24 2.10 D Soft reddish brown occasionally orangish brown and 2.10 E light brown sandy gravelly clay with numerous inclusions of wood posts, ceramics, bricks, metals 2 and rare patches of coal. Gravel is sub angular to 2.60- 3.00 B angular, fine to coarse clinker and brick fragments. 2.60 HV Av=52kPa [MADE GROUND] 2.80- 3.00 B 2.80 3 120.44 Soft dark grey/black slightly sandy silt with a 3.00 120.24 strong hydro carbon odour. [POSSIBLE MADE GROUND] End of Excavation
Excavation Groundwater Plant CAT 428D Width (B) 0.60 Depth Depth Details Date 20/04/2011 Length (C) 2.80 Observed of Pit Shoring None. 3.00 Seepage Date Backfilled 20/04/2011 Stability Unstable during excavation.
Remarks E sample = 1 x vial, 1 x plastic jar and 1 amber jar. Sample at 0.50m was a triple bagged Logged by PST sample of the asbestos pipe. Checked by DRB Symbols and Hand Vane Tests were carried out on intact pieces brought to the surface in the bucket of Figure 1 of 1 abbreviations are the excavator. 03/06/2011 explained on the Trial Pit was reinstated with arisings on completion. accompanying key sheet. All dimensions are in metres. Logged in accordance with BS5930:1999 + A2:2010 TRIAL PIT RECORD Trial Pit Project BURSLEM PORT, STOKE-ON-TRENT Engineer AECOM LIMITED Trial Pit 04 Project No PC114591 National Grid 386568.709 E Client AECOM LIMITED Coordinates 348992.678 N Ground Level 123.13 m OD Samples and Tests Strata Scale 1:50 Level Depth Type Stratum Results Description Depth Legend No m OD G.L. 123.13 Grass over brown slightly sandy gravelly clay with occasional bricks, wood, meta and concrete. Gravel is 1 sub angular to angular, fine to coarse brick and 0.40 D clinker. 0.50 122.63 0.40 E [MADE GROUND] 0.50- 0.90 B Soft brown with some patches of reddish brown and orangish brown sandy gravelly clay with occasional ceramics, metal, wood and brick. Gravel is sub angular to angular, fine to coarse brick shards and clinker. [MADE GROUND] 2 1.60 D 1.60 E 2.00 D
2.40 120.73 2.40- 2.60 B Reddish brown sand. 2.50 E [PROBABLE MADE GROUND] 3
2.80 4 120.33 3.00 D Soft dark grey slightly sandy slightly gravelly silt. 3.00 120.13 [POSSIBLE MADE GROUND] End of Excavation
Excavation Groundwater Plant CAT 428D Width (B) 0.60 Depth Depth Details Date 20/04/2011 Length (C) 2.50 Observed of Pit Shoring None. None encountered during excavation Date Backfilled 20/04/2011 Stability Stable during excavation.
Remarks E sample = 1 x vial, 1 x plastic jar and 1 amber jar Logged by PST Trial Pit was reinstated with arisings on completion. Checked by DRB Symbols and Figure 1 of 1 abbreviations are 03/06/2011 explained on the accompanying key sheet. All dimensions are in metres. Logged in accordance with BS5930:1999 + A2:2010 TRIAL PIT RECORD Trial Pit Project BURSLEM PORT, STOKE-ON-TRENT Engineer AECOM LIMITED Trial Pit 05 Project No PC114591 National Grid 386584.932 E Client AECOM LIMITED Coordinates 348943.225 N Ground Level 122.93 m OD Samples and Tests Strata Scale 1:50 Level Depth Type Stratum Results Description Depth Legend No m OD G.L. 122.93 Grass over brown slightly organic slightly sandy slightly gravelly silt with numerous brick, plastic 0.30 D ceramic toilet basins, metal, concrete and occasional 0.30 E wood. Gravel is sub angular to angular, fine to 0.50- 0.90 B coarse clinker and brick [MADE GROUND]
1.50 D 1
2.00- 2.50 B mc=44% 2.00 E
3.00 D At 3.00m, inclusions of coal. 3.20 119.73 End of Excavation
Excavation Groundwater Plant CAT 428D Width (B) 0.60 Depth Depth Details Date 20/04/2011 Length (C) 2.70 Observed of Pit Shoring None. None encountered during excavation Date Backfilled 20/04/2011 Stability Stable during excavation.
Remarks E sample = 1 x vial, 1 x plastic jar and 1 amber jar Logged by PST Trial Pit was reinstated with arisings on completion. Checked by DRB Symbols and Figure 1 of 1 abbreviations are 03/06/2011 explained on the accompanying key sheet. All dimensions are in metres. Logged in accordance with BS5930:1999 + A2:2010 TRIAL PIT RECORD Trial Pit Project BURSLEM PORT, STOKE-ON-TRENT Engineer AECOM LIMITED Trial Pit 06 Project No PC114591 National Grid 386607.968 E Client AECOM LIMITED Coordinates 348791.381 N Ground Level 123.69 m OD Samples and Tests Strata Scale 1:50 Level Depth Type Stratum Results Description Depth Legend No m OD G.L. 123.69 Grass over slightly sandy gravelly clay with 1 0.25 D occasional rootlets, brick and some metal. Gravel is 0.20 123.49 0.25 E sub angular to angular, fine to coarse brick and 0.30- 0.90 B concrete fragments. [MADE GROUND] 2 Black sandy gravel with a medium cobble content of 0.90 122.79 brick and concrete. Gravel is sub angular to angular, fine to coarse brick shards. 1.20 D mc=26% [MADE GROUND] 1.35 HV Av=44kPa 1.50 E Soft reddish brown slightly sandy clay 3 [PROBABLE MADE GROUND]
2.00- 2.50 B 2.00 121.69 Soft brown slightly sandy slightly gravelly clay . Gravel is sub angular to sub rounded, fine to medium siliceous material. 2.50 HV Av=46kPa [PROBABLE MADE GROUND] 4
3.00 D 3.00 120.69 3.00 HV Av=43kPa End of Excavation
Excavation Groundwater Plant CAT 428D Width (B) 0.60 Depth Depth Details Date 20/04/2011 Length (C) 2.60 Observed of Pit Shoring None. None encountered during excavation Date Backfilled 20/04/2011 Stability Stable during excavation.
Remarks E sample = 1 x vial, 1 x plastic jar and 1 amber jar Logged by PST Hand Vane Tests were carried out on intact pieces brought to the surface in the bucket of Checked by DRB Symbols and the excavator. Figure 1 of 1 abbreviations are Trial Pit was reinstated with arisings on completion. 03/06/2011 explained on the accompanying key sheet. All dimensions are in metres. Logged in accordance with BS5930:1999 + A2:2010 PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP01
TP01 Profile PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP01 Spoil
TP02 PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP02 Profile
TP02 Spoil PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP03
TP03 Profile PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP03 Spoil
TP04 PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP04 Profile
TP04 Spoil PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP05
TP05 Profile PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP05 Spoil
TP06 PHOTOGRAPHS Project Number : PC114591
Project : BURSLEM PORT, Stoke on Trent
TP06 Profile
TP06 Spoil APPENDIX 4 4 Exploratory Hole Location Plan
APPENDIX 5
Laboratory Test Results - Geotechnical
5 DATA SHEET - Laboratory Test Symbols Classification and Strength Chemical Analysis Symbol C - Clay M - Silt Acid Soluble Total sulphate in specimen, expressed
(0 - containing organic matter) as SO3 %, value in brackets expressed as Plasticity L - Low SO4 % I - Intermediate Water Soluble Soluble sulphate in 2:1 water : soil H - High extract, expressed as SO3 g/l, value in V - Very High brackets expressed as SO g/l E - Extremely High 4 In Water Sulphate content of groundwater, Ip Plasticity Index expressed as SO3 g/l, value in brackets expressed as SO g/l % % Retained on 425 µm sieve, shown under Ip 4 value pH pH value wL Liquid Limit Organic content Organic content expressed as a percentage of dry weight wP Plastic Limit Chloride Chloride Ion content expressed as a NP Non-Plastic percentage of dry weight NAT Sample tested in natural state w Moisture Content p Particle Density d MCV, Compaction, CBR Test Quick undrained triaxial tests SS Single stage - 102mm diameter. MCV Moisture Condition Value at natural S3 Single stage - set of 3 moisture content 38mm diameter. MCC Moisture Condition Calibration MS Multistage - 102mm diameter. CCV Chalk Crushing Value D Drained Test HV Hand Vane Compaction PP Pocket Penetrometer (kg/cm²) Type 2.5 = BS 2.5 kg Rammer NST Not suitable for test 4.5 = BS 4.5 kg Rammer V = BS Vibrating Hammer γb Bulk Density γb Bulk Density σ3 Triaxial Cell Pressure γd Dry Density σ1 - σ3 Deviator Stress ## Excessive Strain CBR California Bearing Ratio c Undrained Cohesion Type 2.5 = Test on Specimen u Recompacted using c Cohesion Intercept BS 2.5 kg Rammer φ Angle of Shearing Resistance 4.5 = As above but using BS 4.5 kg Rammer Linear Linear Shrinkage V = As above but using BS Shrink Vibrating Hammer M = Test on open drive mould specimen cut in field S = Soaked Specimen Consolidation Top CBR at top of mould mv Coefficient of Volume Compressibility Bottom CBR at bottom of mould cv50 Coefficient of Consolidation - Log t ND None Detected cv90 Coefficient of Consolidation - √t
All tests performed in accordance with BS 1377 : Rock Parts 1-9 : 1990 incorporating amendments where appropriate. UF Unacceptable Failure
Form REP001 Rev 2 LABORATORY RESULTS - Classification and Strength Project BURSLEM PORT, STOKE-ON-TRENT Project No: PC114591
Sample Classification Strength
Hole Depth TypeSample Description Symbol lp w wp w Test γ σ σ −σ c c (Specimen L b 3 31 u Avg Ref ()(p () Depth) (>425) γd d 3 2 2 2 2 m %%% % Mg/mkN/m kN/m kN/m kN/m
011.10 D C53595 Grey slightly clayey silty very gravelly CI 17 38 21 11 (1.10) SAND (30%)
02 3.30 D C53599 Dark grey organic CLAY. [POSSIBLE CH 31 58 27 50 (3.30) MADE GROUND] (NAT)
03 1.50 D C53600 Brown slightly sandy gravelly clay. CI 22 43 21 25 (1.50) [MADE GROUND] (58%)
05 2.00- B C52703 Dark brown slightly organic slightly MH 24 65 41 44 2.50 sandy slightly gravelly silt. [MADE (40%) (2.00) GROUND]
06 1.20 D C53610 Reddish brown slightly sandy clay. CI 30 48 18 26 (1.20) [PROBABLE MADE GROUND] (9%)
Remarks Tests performed in accordance with BS 1377: 1990 LABORATORY RESULTS - Particle Size Distribution Project: BURSLEM PORT, STOKE-ON-TRENT Hole 01 Sample Depth 1.50-2.00m Project No: PC114591 Sample Type B Sample Ref C52699
Sample Description Grey silty very gravelly SAND
100
90
80
70
60
50 %Finer
40
30
20
10
0 0.001 0.01 0.1 1 10 100 1000 Particle Size (mm) Classification Fine Medium Coarse Fine Medium Coarse Fine Medium Coarse Cobbles Boulders CLAY SILT SAND Gravel
Classification % of each Size Percentage Finer Size Percentage Finer Uniformity Coefficient
125mm 100 2mm 62 184.81 CLAY 4 100mm 100 1.18mm 49 75mm 100 600 µ m 34 Sieving Method SILT 12 63mm 100 425 µ m - Wet sieve 50mm 100 300 µ m 25 Fine Particle Analysis 100 - 46 37.5mm 212 µ m SAND Pipette 28mm 100 150 µ m 19 Method 100 - 20mm 75 µ m Pre-treated Hydrogen GRAVEL 38 14mm 98 63 µ m 16 with Peroxide 10mm 95 20 µ m 12 % loss on 0 0.00 COBBLES 6.3mm - 6 µ m 8 Pre-treatment 5mm 82 2 µ m 4 Particle 2.65 - BOULDERS 0 3.35mm Density (Assumed)
Remarks Test performed in accordance with BS 1377: Part 2: 1990 03/06/2011 Silt and clay proportions taken as all material smaller than 0.063mm. LABORATORY RESULTS - Particle Size Distribution Project: BURSLEM PORT, STOKE-ON-TRENT Hole 02 Sample Depth 0.40-0.90m Project No: PC114591 Sample Type B Sample Ref C52694
Sample Description Dark grey clayey very sandy gravel. [MADE GROUND]
100
90
80
70
60
50 %Finer
40
30
20
10
0 0.001 0.01 0.1 1 10 100 1000 Particle Size (mm) Classification Fine Medium Coarse Fine Medium Coarse Fine Medium Coarse Cobbles Boulders CLAY SILT SAND Gravel
Classification % of each Size Percentage Finer Size Percentage Finer Uniformity Coefficient
125mm 100 2mm 54 Not Available 100mm 100 1.18mm 51 Sieving Method SILT (including 75mm 100 600 µ m 45 CLAY) 17 63mm 100 425 µ m - Wet sieve 50mm 100 300 µ m 34 Fine Particle Analysis 37.5mm 97 212 m - SAND 37 µ 28mm - 150 µ m 23 Method 86 - 20mm 75 µ m Pre-treated GRAVEL 46 14mm 78 63 µ m 17 with 10mm 71 20 µ m - % loss on 0 COBBLES 6.3mm - 6 µ m - Pre-treatment 5mm 62 2 µ m - Particle - BOULDERS 0 3.35mm Density
Remarks Test performed in accordance with BS 1377: Part 2: 1990 03/06/2011 Silt and clay proportions taken as all material smaller than 0.063mm. LABORATORY RESULTS - Particle Size Distribution Project: BURSLEM PORT, STOKE-ON-TRENT Hole 04 Sample Depth 3.00m Project No: PC114591 Sample Type D Sample Ref C53603
Sample Description Dark grey slightly sandy slightly gravelly SILT. [POSSIBLE MADE GROUND]
100
90
80
70
60
50 %Finer
40
30
20
10
0 0.001 0.01 0.1 1 10 100 1000 Particle Size (mm) Classification Fine Medium Coarse Fine Medium Coarse Fine Medium Coarse Cobbles Boulders CLAY SILT SAND Gravel
Classification % of each Size Percentage Finer Size Percentage Finer Uniformity Coefficient
125mm 100 2mm 92 Not Available CLAY 20 100mm 100 1.18mm 90 75mm 100 600 µ m 87 Sieving Method SILT 47 63mm 100 425 µ m - Wet sieve 50mm 100 300 µ m 83 Fine Particle Analysis 100 - 25 37.5mm 212 µ m SAND Pipette 28mm 100 150 µ m 75 Method 100 - 20mm 75 µ m Pre-treated Hydrogen GRAVEL 8 14mm 100 63 µ m 67 with Peroxide 10mm 99 20 µ m 51 % loss on 0 0.47 COBBLES 6.3mm - 6 µ m 32 Pre-treatment 5mm 95 2 µ m 20 Particle 2.65 - BOULDERS 0 3.35mm Density (Assumed)
Remarks Test performed in accordance with BS 1377: Part 2: 1990 03/06/2011 Silt and clay proportions taken as all material smaller than 0.063mm. LABORATORY RESULTS - Particle Size Distribution Project: BURSLEM PORT, STOKE-ON-TRENT Hole 05 Sample Depth 2.00-2.50m Project No: PC114591 Sample Type B Sample Ref C52703
Sample Description Dark brown slightly organic slightly sandy slightly gravelly silt. [MADE GROUND]
100
90
80
70
60
50 %Finer
40
30
20
10
0 0.001 0.01 0.1 1 10 100 1000 Particle Size (mm) Classification Fine Medium Coarse Fine Medium Coarse Fine Medium Coarse Cobbles Boulders CLAY SILT SAND Gravel
Classification % of each Size Percentage Finer Size Percentage Finer Uniformity Coefficient
125mm 100 2mm 83 Not Available CLAY 15 100mm 100 1.18mm 80 75mm 100 600 µ m 77 Sieving Method SILT 45 63mm 100 425 µ m - Wet sieve 50mm 100 300 µ m 72 Fine Particle Analysis 100 - 23 37.5mm 212 µ m SAND Pipette 28mm 100 150 µ m 65 Method 100 - 20mm 75 µ m Pre-treated Hydrogen GRAVEL 17 14mm 95 63 µ m 60 with Peroxide 10mm 93 20 µ m 40 % loss on 0 2.81 COBBLES 6.3mm - 6 µ m 26 Pre-treatment 5mm 88 2 µ m 15 Particle 2.65 - BOULDERS 0 3.35mm Density (Assumed)
Remarks Test performed in accordance with BS 1377: Part 2: 1990 03/06/2011 Silt and clay proportions taken as all material smaller than 0.063mm. APPENDIX 6
Laboratory Test Results - Contamination (Soil)
6
APPENDIX 7
Investigation Techniques and General Notes
7 INVESTIGATION TECHNIQUES
INTRODUCTION WINDOW SAMPLING
The following brief review of Ground Investigation techniques, generally used as This technique involves the driving of an open-ended tube into the ground and part of most Site Investigations in the UK, summarises their methodology, retrieval of the soil which enters the tube. The term “window sample” arose advantages and limitations. Detailed descriptions of the techniques are available from the original device which had a “window” or slot cut into the side of the and can be provided on request. This review should be read in conjunction with tube through which samples were taken. This has now been superseded by the the accompanying General Notes. use of a thin-walled plastic liner within a sampler which has a solid wall. Diameters range from 36 to 86mm. Such samples can be used for qualitative TRIAL PITS logging, selection of samples for classification and chemical analysis and for obtaining a rudimentary assessment of strength. The trial pit is amongst the most simple yet effective means of identifying shallow ground conditions on a site. Its advantages include simplicity, speed, potential Driving devices can be hand-held or machine mounted and the drive tubes are accuracy and cost-effectiveness. The trial pit is most commonly formed using a typically in 1m lengths. The hole formed is not cased, however, and hence the backacting excavator which can typically determine ground conditions to some 4 success of this technique is limited when soils and groundwater conditions are metres below ground level. Hand excavation is often used to locate, expose and such that the sides of the hole collapse on withdrawal of the sampler. detail existing foundations, features or services. In general, it is difficult to extend Obstructions within the ground, the density of the material or its strength can pits significantly below the water table in predominantly granular soils, where flows also limit the depth and rate of penetration of this light-weight investigation can cause instability. Unless otherwise stated, the trial pits will not have been technique. Nevertheless, it is a valuable tool where access is constrained such provided with temporary side support during their construction. Under such as within buildings or on embankments. Depths of up to 8m can be achieved in circumstances ground conditions to some 1.20 metres can be closely inspected, suitable circumstances but depths of 4m to 6m are more common. subject to stability assessment, but below this depth, entrance into the pit is not permitted in the absence of shoring and hence observations will have been made EXPLORATORY HOLE RECORDS from ground surface and samples taken from the excavator bucket. The data obtained by these techniques are generally presented on Trial Pit, Trends in strata type, level and thickness can be determined, shear surfaces Borehole, Drillhole or Window Sample Records. The descriptions of strata result identified and the behaviour of plant, excavation sides and excavated materials can from information gathered from a number of sources which may include be related to the construction process. They are particularly valuable in land slip published geological data, preliminary field observations and descriptions, insitu investigations. Some types of insitu test can be undertaken in such pits and large test results, laboratory test results and specimen descriptions. A key to the disturbed or block samples obtained. symbols and abbreviations used accompanies the records. The descriptions on the exploratory hole records accommodate but may not necessarily be identical CABLE PERCUSSION BORING to those on any preliminary records or the laboratory summaries.
The light Cable Percussion technique of soft ground boring, typically at a diameter The records show ground conditions at the exploratory hole locations. The of 150mm, is a well established simple and flexible method of boring vertical holes degree to which they can be used to represent conditions between or beyond and generally allows data to be obtained in respect of strata conditions other than such holes, however, is a matter for geological interpretation rather than factual rock. A tubular cutter (for cohesive soils) or shell with a flap valve (for granular reporting and the associated uncertainties must be recognised. soils) is repeatedly lifted and dropped using a winch and rope operating from an “A” frame. Soil which enters these tools is regularly removed and either sampled DYNAMIC PROBING for subsequent examination or test, or laid to one side for backfilling. Steel casing will have been used to prevent collapse of the borehole sides where necessary. A This technique typically measures the number of blows of a standard weight degree of disturbance of soil and mixing of layers is inevitable and the presence of falling over a standard height to advance a cone-ended rod over sequential very thin layers of different soils within a particular stratum may not be identified. standard distances (typically 100mm). Some devices measure the penetration Changes in strata type can only be detected on recognition of a change in soil of the probe per standard blow. It is essentially a profiling tool and is best used samples at surface, after the interface has been passed. For the foregoing in conjunction with other investigation techniques where site-specific correlation reasons, depth measurements should not be considered to be more accurate than can be used to delineate the distribution of soft or loose soils or the upper 0.10 metre. horizon of a dense or strong layer such as rock.
In cohesive soils cylindrical samples are retrieved by driving or pushing in 100mm Both machine-driven and hand-driven equipment is available, the selection nominal diameter tubes. In soft soils, piston sampling or vane testing may be depending upon access restrictions and the depth of penetration required. It is undertaken. In granular soils and often in cohesive materials, insitu Standard particularly useful where access for larger equipment is not available, Penetration Tests (SPT’s) are performed. The SPT records the number of standard disturbance is to be minimised or where there are cost constraints. No samples blows required to drive a 50mm diameter open or cone ended probe for 300mm are recovered and some techniques leave a sacrificial cone head in the ground. after an initial 150mm penetration. A modified method of recording is used in As with other lightweight techniques, progress is limited in strong or dense soils. more dense strata. Small disturbed samples are obtained throughout. The results are presented both numerically and graphically. Depths of up to 10m are commonly achieved in suitable circumstances. The technique can determine ground conditions to depths in excess of 30 metres under suitable circumstances and usually causes less surface disturbance than trial The hand-driven DCP probing device has been calibrated by the TRL to provide pitting. a profile of CBR values over a range of depths of up to 1.50m.
ROTARY DRILLING INSTRUMENTATION
Rotary Drilling to produce cores by rotating an annular diamond-impregnated tube The most common form of instrument used in site investigation is either the or barrel into the ground is the technique most appropriate to the forming of site standpipe or else the standpipe piezometer which can be installed in investigation boreholes through rock or other hard strata. It has the advantage of investigation holes. They are used to facilitate monitoring of groundwater levels being able to be used vertically or at an angle. Core diameters of less than and water sampling over a period of time following site work. Normally a 100mm are most common for site investigation purposes. Core is normally standpipe would be formed using rigid plastic tubing which has been perforated retrieved in plastic lining tubes. A flushing fluid such as air, water or foam is used or slotted over much of its length whilst a standpipe piezometer would have a to cool the bit and carry cuttings to the surface. filter tip which would be placed at a selected level and the hole sealed above and sometimes below to isolate the zone of interest. Groundwater levels are Examination of cores allows detailed rock description and generally enables angled determined using an electronic “dipmeter” to measure the depth to the water discontinuity surfaces to be observed. However, vertical holes do not necessarily surface from ground level. Piezometers can also be used to measure reveal the presence of vertical or near-vertical fissures or joint discontinuities. The permeability. They are simple and inexpensive instruments for long term core type and/or techniques used. Where open hole rotary drilling is employed, monitoring but response times can limit their use in tidal areas and access to the descriptions of strata result from examination at surface of small particles ejected ground surface at each instrument is necessary. Remote reading requires more from the borehole in the flushing medium. In consequence, no indication of sophisticated hydraulic, electronic or pneumatic equipment. fissuring, bedding, consistency or degree of weathering can be obtained. Small scale plant can be used for auger drilling to limited depths where access is Settlement can be monitored using surface or buried target plates whilst lateral constrained. movement over a range of depths is monitored using slip indicator or inclinometer equipment. Depths in excess of 60 metres can be achieved under suitable circumstances using rotary techniques, with minimal surface disturbance.
Geotechnics Limited © The Geotechnical Centre, 203 Torrington Avenue, Tile Hill, Coventry. CV4 9AP
GENERAL NOTES
1. The report is prepared for the exclusive use of the Client named in the 12. All the data required by the test procedures are recorded on document and copyright subsists with Geotechnics Limited. Prior written individual test sheets but the results in the report are presented in permission must be obtained to reproduce all or part of the report. It is summary form to aid understanding and assimilation for design prepared on the understanding that its contents are only disclosed to purposes. Where all details are required, these can be made parties directly involved in the current investigation, preparation and available. development of the site. 13. Whilst the report may express an opinion on possible 2. Further copies may be obtained with the Client's written permission, configurations of strata between or beyond exploratory holes, or on from Geotechnics Limited with whom the master copy of the document the possible presence of features based on either visual, verbal, will be retained. written, cartographical, photographic or published evidence, this is for guidance only and no liability can be accepted for its accuracy. 3. The report and/or opinion is prepared for the specific purpose stated in the document and in relation to the nature and extent of proposals 14. Classification of materials as Made Ground is based on the made available to Geotechnics Limited at that time. Re-consideration inspection of retrieved samples or exposed excavations. Where it is obvious that foreign matter such as paper, plastic or metal is will be necessary should those details change. The recommendations present, classification is clear. Frequently, however, for fill materials should not be used for other schemes on or adjacent to the site without that arise from the adjacent ground or from the backfilling of further reference to Geotechnics Limited. excavations, their visual characteristics can closely resemble those of undisturbed ground. Other evidence such as site history, exploratory hole location or other tests may need to be drawn 4. The assessment of the significance of the factual data, where called for, upon to provide clarification. For these reasons, classification of is provided to assist the Client and his Engineer and/or Advisers in the soils on the exploratory hole records as either Made Ground or preparation of their designs. naturally occurring strata, the boundary between them and any interpretation that this gives rise to should be regarded as 5. The report is based on the ground conditions encountered in the provisional and subject to re-evaluation in the light of further data.
exploratory holes together with the results of field and laboratory testing 15. The classification of materials as Topsoil is generally based on in the context of the proposed development. The data from any visual description and should not be interpreted to mean that the commissioned desk study and site reconnaissance are also drawn upon. material so described complies with the criteria for Topsoil used in There may be special conditions appertaining to the site, however, which BS 3882 (2007). Specific testing would be necessary where such definition is a requirement. are not revealed by the investigation and which may not be taken into
account in the report. 16. Ground conditions should be monitored during the construction of
the works and the report should be re-evaluated in the light of 6. Methods of construction and/or design other than those proposed by the these data by the supervising geotechnical engineers. designers or referred to in the report may require consideration during
the evolution of the proposals and further assessment of the 17. Any comments on groundwater conditions are based on geotechnical and any geoenvironmental data would be required to observations made at the time of the investigation, unless provide discussion and evaluations appropriate to these methods. specifically stated otherwise. It should be noted, however, that the observations are subject to the method and speed of boring, drilling or excavation and that groundwater levels will vary due to seasonal 7. The accuracy of results reported depends upon the technique of or other effects. measurement, investigation and test used and these values should not be regarded necessarily as characteristics of the strata as a whole (see 18. Any bearing capacities for conventional spread foundations which accompanying notes on Investigation Techniques). Where such are given in the report and interpreted from the investigation are for bases at a minimum depth of 1m below finished ground level in measurements are critical, the technique of investigation will need to be naturally occurring strata and at broadly similar levels throughout reviewed and supplementary investigation undertaken in accordance individual structures, unless otherwise stated. The foundations with the advice of the Company where necessary. should be designed in accordance with the good practice embodied in BS 8004:1986 - Foundations, supplemented for housing by 8. The samples selected for laboratory test are prepared and tested in NHBC Standards. Foundation design is an iterative process and bearing pressures may need adjustment or other measures may accordance with the relevant Clauses of BS 1377 Parts 1 to 8, where need to be taken in the context of final layouts and levels prior to appropriate, in Geotechnics Limited’s UKAS accredited Laboratory, finalisation of proposals. where possible. A list of tests is given. 19. Unless specifically stated, the investigation does not take account 9. Tests requiring the use of another laboratory having UKAS accreditation of the possible effects of mineral extraction or of gases from fill or where possible are identified. natural sources within, below or outside the site.
10. Any unavoidable variations from specified procedures are identified in 20. The costs or economic viability of the proposals referred to in the the report. report, or of the solutions put forward to any problems encountered, will depend on very many factors in addition to 11. Specimens are cut vertically, where this is relevant and can be identified, geotechnical or geoenvironmental considerations and hence their unless otherwise stated. evaluation is outside the scope of the report.
Geotechnics Limited © The Geotechnical Centre, 203 Torrington Avenue, Tile Hill, Coventry. CV4 9AP
AECOM Preliminary Ground Investigation Report
Appendix B – Summary of Geochemical Test Results
Sample ID TP01 TP01 TP02 TP02 TP02 TP03 TP03 TP03 TP04 TP04 TP04 TP05 TP05 TP06 TP06 Sample Desc 0.5m 1.9 0.3 2.2 3 0.35 1.5 2.1 0.4 1.6 2.5 0.3 2 0.25 1.5 Analyte: Method Code: Units: min max screening count Arsenic (MS) ICPMSS mg/kg 27.2 16.7 12.1 10.4 16.7 11.9 10.3 16.6 42.7 16.9 14.2 7.5 7.5 42.7 35 12 Cadmium (MS) ICPMSS mg/kg 1 0.7 0.1 0.4 0.7 0.1 0.4 0.5 0.2 0.5 2.2 0.1 0.1 2.2 83 12 Chromium (MS) ICPMSS mg/kg 24.4 34.6 39.9 19.2 37.5 42.3 19.8 9.7 37.1 38.2 519.4 48.2 9.7 519.4 4.2 12 Copper (MS) ICPMSS mg/kg 89 42 1 24 44 1 25 143 47 11 74 15 1 143 6200 12 Lead (MS) ICPMSS mg/kg 595 148 27 90 168 33 103 41 59 207 364 22 22 595 450 12 Mercury (MS) ICPMSS mg/kg 0.7 0.1 0.1 0.4 0.1 0.1 0.4 0.2 0.3 0.1 0.1 0.1 0.1 0.7 8.3 12 Nickel (MS) ICPMSS mg/kg 89.6 26.7 22.2 16.4 30.4 24.6 17.5 15.5 37.1 30.3 52.8 36.9 15.5 89.6 780 12 Selenium (MS) ICPMSS mg/kg 432 12 31 12242 1 4 59012 Zinc (MS) ICPMSS mg/kg 396 190 67 82 228 81 98 93 122 155 599 58 58 599 40000 12 pH units (AR) PHSOIL pH Units 8.29 7.64 8 6.82 8.49 8.64 8.33 8.57 8.36 7.9 7.82 8.09 6.82 8.64 - 12
Naphthalene PAH_MS-SIM_80 mg/kg 0.11 0.46 0.04 0.63 0.55 0.04 0.04 0.63 0.69 6 Acenaphthylene PAH_MS-SIM_80 mg/kg 0.05 0.25 0.03 0.03 0.31 0.03 0.03 0.31 4600 6 Acenaphthene PAH_MS-SIM_80 mg/kg 0.05 0.58 0.05 0.05 0.15 0.05 0.05 0.58 4600 6 Fluorene PAH_MS-SIM_80 mg/kg 0.05 0.35 0.04 0.04 0.21 0.04 0.04 0.35 3100 6 Phenanthrene PAH_MS-SIM_80 mg/kg 0.45 1.08 0.14 0.36 1.68 0.03 0.03 1.68 990 6 Anthracene PAH_MS-SIM_80 mg/kg 0.15 1.06 0.04 0.07 0.49 0.04 0.04 1.06 24000 6 Fluoranthene PAH_MS-SIM_80 mg/kg 1.57 4.87 0.26 0.5 2.3 0.03 0.03 4.87 1000 6 Pyrene PAH_MS-SIM_80 mg/kg 1.24 3.44 0.22 0.5 1.83 0.03 0.03 3.44 2400 6 Benzo[a]anthracene PAH_MS-SIM_80 mg/kg 0.79 2.77 0.18 0.59 1.59 0.06 0.06 2.77 5.8 6 Chrysene PAH_MS-SIM_80 mg/kg 0.9 1.83 0.15 0.39 1.05 0.02 0.02 1.83 10 6 Benzo[bk]fluoranthene 1.41 2.33 0.22 0.64 1.31 0.07 0.07 2.33 N/A 6 Benzo[a]pyrene 0.88 1.33 0.1 0.37 0.82 0.04 0.04 1.33 1 6 Indeno[1,2,3-cd]pyrene PAH_MS-SIM_80 mg/kg 0.39 0.69 0.06 0.26 0.38 0.04 0.04 0.69 4.4 6 Dibenzo[a,h]anthracene PAH_MS-SIM_80 mg/kg 0.07 0.1 0.04 0.04 0.06 0.04 0.04 0.1 0.94 6 Benzo[g,h,i]perylene PAH_MS-SIM_80 mg/kg 0.52 0.69 0.06 0.27 0.43 0.04 0.04 0.69 47 6 Total (USEPA16) PAHs PAH_MS-SIM_80 mg/kg 8.5 21.8 1.4 4.6 13.2 0.6 0.6 21.8 N/A 6 Benzo[b]fluoranthene PAH_MS-SIM_80 mg/kg 1.02 1.68 0.16 0.46 0.94 0.05 0.05 1.68 7.3 6 Benzo[k]fluoranthene PAH_MS-SIM_80 mg/kg 0.39 0.65 0.06 0.18 0.37 0.02 0.02 0.65 10 6 PAH_MS-SIM_80 mg/kg 0 0 - 0 PCB28 PCB_CON ug/kg 5 5 5 5 5 5 5 5 5 6 PCB52 PCB_CON ug/kg 5 5 5 5 5 5 5 5 5 6 PCB101 PCB_CON ug/kg 5 5 5 5 5 5 5 5 5 6 PCB118 PCB_CON ug/kg 5 5 5 5 5 5 5 5 5 6 PCB138 PCB_CON ug/kg 5 5 5 5 34 5 5 34 5 6 PCB153 PCB_CON ug/kg 5 5 5 5 5 5 5 5 5 6 PCB180 PCB_CON ug/kg 5 5 5 5 15 5 5 15 5 6
MTBE mg/kg 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005 Benzene GRO_HSA mg/kg 0.005 0.005 0.005 0.011 0.005 0.005 0.005 0.011 0.11 6 Toluene GRO_HSA mg/kg 0.005 0.005 0.005 0.028 0.005 0.005 0.005 0.028 250 6 Ethyl benzene GRO_HSA mg/kg 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005 69 6 m/p-Xylene GRO_HSA mg/kg 0.005 0.027 0.005 0.017 0.005 0.005 0.005 0.027 23 6 o-Xylene GRO_HSA mg/kg 0.005 0.005 0.005 0.008 0.005 0.005 0.005 0.008 24 6 Aliphatics >C5-C6 mg/kg 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 16 6 Aliphatics >C6-C8 mg/kg 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 37 6 Aliphatics >C8 - C10 TPHSI_FID_STD mg/kg 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 9 6 Aliphatics >C10 - C12 TPHSI_FID_STD mg/kg 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 43 6 Aliphatics >C12 - C16 TPHSI_FID_STD mg/kg 4 4 4 4 4 4 4 4 4300 6 Aliphatics >C16 - C21 TPHSI_FID_STD mg/kg 7 40 7 7 7 7 7 40 6 Aliphatics >C21 - C35 TPHSI_FID_STD mg/kg 7 658 7 65 7 7 7 65829000 6 total aliphatics C5-C35 mg/kg 19 698 19 65 19 19 19 698 N/A 6 Aromatics >C5-EC7 mg/kg 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 100 6 Aromatics >C7-C8 mg/kg 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 250 6 Aromatics >C8 - C10 TPHSI_FID_STD mg/kg 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 15 6 Aromatics >C10 - C12 TPHSI_FID_STD mg/kg 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 84 6 Aromatics >C12 - C16 TPHSI_FID_STD mg/kg 4 29 4 4 4 4 4 29 1600 6 Aromatics >C16 - C21 TPHSI_FID_STD mg/kg 7 183 7 7 7 7 7 183 1200 6 Aromatics >C21 - C35 TPHSI_FID_STD mg/kg 81 756 7 7 7 7 7 756 1300 6 Total aromatics mg/kg 81 968 19 19 19 19 19 968 N/A 6 Total aromatics & aliphatics mg/kg 81 1666 38 65 38 38 38 1666 N/A 6
4-Methylphenol VOCHSAS ug/kg 10 10 10 63 10 10 10 63 10 6 2-Methylnaphthalene VOCHSAS ug/kg 173 804 33 1025 213 59 33 1025 10 6 Carbozole ug/kg 44 140 15 64 111 10 10 140 10 6 dibenzofurane ug/kg 85 722 17 243 344 20 17 722 10 6 Toluene ug/kg 3 12 3 11 3 3 3 12 250 6
Title: Summary of geochemical laboratory test results Granular Made Ground 14 Queen Victoria Road Tel: +44(0)24 7625 3300 Cohesive Made Ground Project: Coventry Fax: +44(0)24 7625 3301 Burslem Port CV1 3PJ www.aecom.com Exceed Screening Value Checked: Designed: DCS Notes: Approved: Date: June 2010 AECOM Preliminary Ground Investigation Report
Appendix C – Preliminary Design Brief
BURSLEM PORT PROJECT – ENGINEERING VIABILITY AND COSTS
ENGINEERING DESIGN BRIEF
MAY 2011
CITY OF STOKE ON TRENT
Version Date Originator Approved Date Circulation
1 25/05/11 VC
Page: 1 of 5 Doc. FA/04 Revised: April 2009 C:\Documents and Settings\stannardd\Local Settings\Temporary Internet Files\Content.Outlook\T5QHSO3S\Burslem Brief v1 (2).docx
BURSLEM PORT PROJECT – ENGINEERING VIABILITY AND COSTS
MAY 2011
DESIGN BRIEF
1 INTRODUCTION
This design brief identifies the parameters and requirements set down by the Burslem Port Project team and British Waterways for the formulation of an outline design for the restoration of the Burslem Arm of the Trent & Mersey Canal. The objective of the design, and its corresponding output, is to enable budges costs for construction works to be calculated and ultimately to go forward as supporting documentation as part of a planning application submission.
Opened in 1805 the successful Burslem Arm served wharves along its banks providing access for trade to the wider canal network. However the increasing use of road transportation saw trade decline and a breach in 1961, as result of mining subsidence resulted in the arm’s closure.
2 CANAL RESTORATION OPTIONS
Previous works undertaken by Ove Arup and Partners (Burslem Arm Feasibility Study, October 2005), Roy Sutton (Trent & Mersey Canal, Burslem Arm, Minimum Cost Restoration, August 2010) and others have identified a number of possible options and solutions for the restoration of the arm for which Roy Sutton’s report has been the assessment on which this design brief is based.
3 DESIGN REQUIREMENTS
3.1 Minimum cost The current economic climate has resulted in the outlook for local regeneration being significantly reduced and as a consequence the design is to be based on a least cost solution that provides a water-tight, safe navigable waterway to the approval of British Waterways.
This is to be produced on the basis of Roy Sutton’s Report which has been generally accepted as offering the most appropriate solution. The report splits the arm into three sections broadly in line with the space available and nature of adjacent land.
Page: 2 of 5 Doc. FA/04 Revised: April 2009 C:\Documents and Settings\stannardd\Local Settings\Temporary Internet Files\Content.Outlook\T5QHSO3S\Burslem Brief v1 (2).docx
The design process will confirm the current report recommendations with any departures that are identified being agreed with the Client as design progresses.
3.2 British Waterway design standards The minimum waterway design standards for the Burslem Arm are based on those of the Trent & Mersey Canal and are to be taken as follows:- Canal craft dimensions to be accommodated, Length 22.5m Beam 2.15m Draught 1.0m Air draught 2.2m
Waterway dimensions, General Water depth 1.5m Freeboard 0.35m
Soft edge Bed width 5.0m Slope gradient (max) 1 in 2
Hard edge to both sides, single passage Width between fenders 3.0m
Hard edge to both sides, duel passage or mooring Width between fenders 5.5m
Primarily for the purposes of safety, though also for the ease of any future de- watering requirements of the arm, a double stop-plank arrangement shall be detailed within the arm close to the junction with the Trent & Mersey Canal. It shall be dimensioned in line with existing waterway structures locally, for which details will be obtained from British Waterways.
3.3 General requirements In the event that through the development of the design it is deemed necessary to include a channel that is only sufficiently wide enough to accommodate the passage of a single canal craft a temporary lay-by at either end of the section shall additionally be incorporated.
The design shall take careful consideration of the need for an appropriate entrance to the arm with the geometry of entry walls from the Trent & Mersey Canal suitable to permit safe passage of craft whilst maintaining the integrity of the canal structure.
Lighting is to be provided at mooring locations, with a capacity for reducing to two-thirds and one-third light intensity. The design and control should reflect the need to reduce energy use.
Page: 3 of 5 Doc. FA/04 Revised: April 2009 C:\Documents and Settings\stannardd\Local Settings\Temporary Internet Files\Content.Outlook\T5QHSO3S\Burslem Brief v1 (2).docx
The signing and information provision will be designed in accordance with BW standards, accessibility guidance and current best practice.
Surfacing details for paths and adjacent land shall be as directed by the Client.
Mooring requirements shall be..
Access bridge/crossing the arm shall be..
3.4 Specific Design Requirements Design loading adjacent to waterway walls shall be taken as 10kN/m 2.
The design life for concrete structure is 100 years. The design life for civil works is 60 years. The design life requirement for geotextiles is 30 years.
Maximum permissible settlement between concrete units is to be 5mm.
3.5 British Standards & Eurocodes Design will be undertaken and based on the prevailing British Standards and Eurocodes. The following typical list of documents will be consulted as necessary:-
BS 6031: 2009 Code of Practice for Earthworks BS 8500: 2006 Concrete – Complementary British Standard to BS EN 206-1 BS EN 1536:2010 Execution of special geotechnical works - Bored piles BS EN1990:2002 Basis of Design (incorporating corrigendum December 2008 and April 2010) BS EN 1991-1-1:2002 Actions on Structures, General actions. Densities, self-weight, imposed loads for buildings (incorporating corrigenda December 2004 and March 2009) BS EN 1991-1-5:2003 Actions on Structures, General actions. Thermal actions (incorporating corrigenda December 2004 and March 2009) BS EN 1991-1-6:2005 Actions on Structures, General actions. Actions during execution (incorporating corrigendum July 2008) BS EN 1992-1-1:2004 Design of Concrete Structures, General, Common rules and rules for buildings (incorporating corrigendum January 2008) BS EN 1992-3:2006 Design of Concrete Structures, Liquid retaining and containment structures
Page: 4 of 5 Doc. FA/04 Revised: April 2009 C:\Documents and Settings\stannardd\Local Settings\Temporary Internet Files\Content.Outlook\T5QHSO3S\Burslem Brief v1 (2).docx
BS EN 1993-5:2007 Piling (incorporating corrigendum May 2009) BS EN 1994-2:2005 Design of composite steel and concrete structures, General rules and rules for bridges (incorporating corrigendum July 2008) BS EN 1997-1:2004 Geotechnical design, General rules (incorporating corrigendum February 2004) BS EN 14844:2006 Precast Concrete Products - Box Culverts (Jul 2006)
3.6 Constraints Services. Service providers will be consulted as the design progresses to ensure that the final proposal is acceptable to all parties.
Currently known services that cross the scheme are BT telephone lines and Severn Trent sewers.
4 DELIVERABLES The design shall provide plans and section suitable for accompanying a planning application submission.
5 PROGRAMME
Page: 5 of 5 Doc. FA/04 Revised: April 2009 C:\Documents and Settings\stannardd\Local Settings\Temporary Internet Files\Content.Outlook\T5QHSO3S\Burslem Brief v1 (2).docx AECOM Preliminary Ground Investigation Report
Appendix D - Guidance on AECOM Approach to Contaminated Land Risk Assessment
AGAC Screening Values (Sand Soil) 1.0 Date: 15/10/2009 (mg/kg) LandUse AGAC Residential with homegrown produce AGAC Residential without homegrown produce AGAC Commercial Chemical 1 2.5 6 1 2.5 6 1 2.5 6 Arsenic 32 32 32 35 35 35 630 630 630 Beryllium (inhalation) 50 50 50 50 50 50 410 410 410 Beryllium (oral) 110 110 110 150 150 150 3900 3900 3900 Boron 290 290 290 10000 10000 10000 190000 190000 190000 Cadmium 10 10 10 83 83 83 230 230 230 Chromium (III) 3000 3000 3000 3000 3000 3000 30000 30000 30000 Chromium (VI) (inhalation) 4.2 4.2 4.2 4.2 4.2 4.2 34 34 34 Chromium (VI) (oral) 12 12 12 84 84 84 2000 2000 2000 Copper 2300 2300 2300 6200 6200 6200 71000 71000 71000 Mercury (elemental) 0.07 0.17 0.41 0.07 0.17 0.41 4.2*(15000) 11*(15000) 26*(15000) Mercury (inorganic) 160 160 160 230 230 230 3600 3600 3600 Mercury (methyl) 7.3 9.6 11 8.3 11 14 380 400 410 Nickel (oral HCV) 530 530 530 780 780 780 22000 22000 22000 Nickel (inhalation only) 120 120 120 120 120 120 1700 1700 1700 Selenium 350 350 350 590 590 590 13000 13000 13000 Vanadium 74 74 74 180 180 180 3100 3100 3100 Zinc 3700 3700 3700 40000 40000 40000 660000 660000 660000 Benzene 0.052 0.1 0.23 0.11 0.2 0.44 27 50 97 Toluene 92 210 480 250 570 1200 830*(410000) 1900*(410000) 4300*(410000) Ethylbenzene 42 99 230 69 160 370 510*(180000) 1200*(180000) 2800*(180000) m‐Xylene 20 49 110 23 54 120 610*(300000) 1500*(300000) 3400*(300000) o‐Xylene 21 51 120 24 58 130 470*(310000) 1100*(310000) 2600*(310000) p‐Xylene 19 47 110 22 52 120 560*(300000) 1300*(300000) 3200*(300000) Phenol 170 280 410 300 420 520 3200~(34000) 3200~(37000) 3200~(38000) Acenaphthene 200(190) 480(450) 1000(960) 4600(1300) 4600(2300) 4600(3300) 100000(87000) 100000(99000) 100000 Acenaphthylene 160 390(380) 840(820) 4600(1300) 4600(2400) 4600(3400) 100000(88000) 100000(99000) 100000 Anthracene 2300(2200) 5000(4900) 9300(9100) 24000(19000) 24000(21000) 24000(23000) 540000(530000) 540000(530000) 540000 Benz(a)anthracene 4.2(3.3) 4.9 6 5.8(4) 5.4 6.3 100(93) 100(96) 100(98) Benzo(a)pyrene 0.82 0.94 0.98 1 1 1 14 14 14 Benzo(b)fluoranthene 5.7(5.5) 6.5 7 7.3(7) 7.3(7.2) 7.3 100 100 100 Benzo(ghi)perylene 44(43) 46(45) 47(46) 47(46) 47 47 660(650) 660 660 Benzo(k)fluoranthene 8.7(8.5) 9.6(9.5) 10 10 10 10 140 140 140 Chrysene 6.6(6) 8.4(8) 9.4(9.2) 10(8.9) 10(9.7) 10 140 140 140 Dibenzo(ah)anthracene 0.82(0.76) 0.88(0.86) 0.91(0.9) 0.94(0.87) 0.94(0.91) 0.94(0.92) 13(12) 13 13 Fluoranthene 250 460 670 1000(970) 1000(990) 1000 22000 22000 22000 Fluorene 160(150) 380(360) 780(760) 3100(1500) 3100(2200) 3100(2700) 72000(65000) 72000(69000) 72000(71000) Indeno(123‐cd)pyrene 3.3(3.1) 3.9(3.8) 4.2(4.1) 4.4(4.1) 4.4(4.3) 4.4 62(61) 62(61) 62 Naphthalene 0.67 1.6 3.8 0.69 1.6 3.9 20000(190) 20000(470) 20000(1000) Phenanthrene 92(91) 200 370 990(820) 990(920) 990(960) 22000 22000 22000 Pyrene 560 1000 1500 2400(2300) 2400(2300) 2400 54000 54000 54000 1,2‐Dichloroethane 0.0022 0.0034 0.0063 0.0024 0.0037 0.0067 0.63 0.95 1.7 1,1,1‐Trichloroethane 2.6 5.4 12 2.6 5.5 12 680 1400 3100 1,1,1,2‐Tetrachloroethane 0.4 0.95 2.2 0.44 1 2.4 100 250 570 1,1,2,2‐Tetrachloroethane 0.77 1.6 3.7 1.1 2.3 5.2 260 550 1100 Tetrachloroethene 0.4 0.92 2.1 0.41 0.95 2.2 120 280 640 Chlorobenzene 0.13 0.3 0.71 0.13 0.3 0.71 57 130 300 Hexachloro‐1,3‐Butadiene 0.086 0.2 0.5 0.087 0.2 0.51 29 63 110 Atrazine 0.23 0.55 1.2 31 31 31 870 870 870 Aliphatic EC5‐EC6 16 28 55 16 28 55 4600000(4500) 4600000(7700) 4600000(15000) Aliphatic >EC6‐EC8 37 79 170 37 79 170 4700000(10000) 4700000(21000) 4700000(47000) Aliphatic >EC8‐EC10 8.9 21 51 9 21 51 94000(2400) 94000(5700) 94000(13000) Aliphatic >EC10‐EC12 43 100 250 43 100 250 95000(11000) 95000(26000) 95000(52000) Aliphatic >EC12‐EC16 4200(350) 4300(860) 4300(1800) 4300(350) 4300(860) 4300(1800) 95000(63000) 95000(83000) 95000(90000) Aliphatic >EC16‐EC35 29000 48000 65000 29000 48000 66000 1600000 1700000 1800000 Aliphatic >EC35‐EC44 29000 48000 65000 29000 48000 66000 1600000 1700000 1800000 Aromatic >EC5‐EC7 46 94 200 100 210 440 400000(26000) 400000(49000) 400000(92000) Aromatic >EC7‐EC8 92 210 480 250 570 1200 410000(57000) 410000(110000) 410000(190000) Aromatic >EC8‐EC10 14 35 82 15 38 89 36000(4000) 36000(9300) 36000(19000) Aromatic >EC10‐EC12 54 130 280 84 200 460 37000(18000) 37000(29000) 37000(34000) Aromatic >EC12‐EC16 130 300 580 1600(800) 1600(1300) 1600 38000(36000) 38000(37000) 38000(37000) Aromatic >EC16‐EC21 240 480 760 1200 1300 1300 28000 28000 28000 Aromatic >EC21‐EC35 880 1100 1200 1300 1300 1300 28000 28000 28000 Aromatic >EC35‐EC44 880 1100 1200 1300 1300 1300 28000 28000 28000 Aromatic and aliphatic >EC44‐EC70 1100 1200 1200 1300 1300 1300 28000 28000 28000 2‐chlorophenol 3.5 8.3 18 65 95 110 3900 4200 4300 2,4‐dichlorophenol 0.83 1.9 4.4 60 88 110 3800 4100 4300 2,4,6‐trichlorophenol 1.3 3.2 7.4 86 110 120 4400(4100) 4400(4300) 4400 2,3,4,6‐tetrachlorophenol 0.83 2 4.6 86 110 120 4400(4100) 4400(4300) 4400 Pentachlorophenol 0.54 1.3 2.9 28(22) 31 35 1300(1200) 1300 1300 Tetrachloromethane (Carbon Tetrachloride) 0.0077 0.017 0.037 0.0077 0.017 0.037 3 6.7 15 Trichloroethene (TCE) 0.044 0.096 0.2 0.044 0.098 0.22 11 24 55 Trichloromethane (Chloroform) 0.33 0.61 1.3 0.35 0.67 1.4 100 180 380 Chloroethene (Vinyl Chloride) 0.00024 0.00032 0.00049 0.00026 0.00033 0.00051 0.072 0.092 0.14 2,4,6 Trinitrotoluene 1.5 3.6 7.9 56 57 57 1000 1000 1000 RDX 3.2 7.2 15 370(360) 370 370 6400 6400 6400 HMX 5.5 12 24 6500 6500 6500 100000 100000 100000 Aldrin 1.6 1.9 2 1.9 2 2.1 53 53 54 Dieldrin 0.69(0.68) 1.3 2.2(2.1) 3.9(3.2) 3.9(3.6) 3.9(3.8) 92(90) 92(91) 92(91) Dichlorvos 0.27 0.57 1.2 26 33 37 870 890 900 Alpha‐Endosulfan 3(2.7) 7.3(6.6) 16(15) 170(25) 170(50) 170(86) 3700(2300) 3700(3000) 3700(3400) Beta‐Endosulfan 2.8(2.6) 6.8(6.4) 15(14) 170(36) 170(67) 170(100) 3700(2700) 3700(3200) 3700(3500) Alpha‐Hexachlorocyclohexanes (Including Lindane) 19 45 99 660(460) 660(580) 660(650) 15000(14000) 15000(14000) 15000 Beta‐Hexachlorocyclohexanes (Including Lindane) 1.6 3.9 8.5 52(50) 52(51) 52 1100 1100 1100 Gamma‐Hexachlorocyclohexanes (Including Lindane) 0.57 1.3 3 19 21 23 550(540) 550 550 1,2‐Dichlorobenzene 6.7 16 38 6.8 16 39 560000(2000) 560000(4900) 560000(11000) 1,3‐Dichlorobenzene 0.11 0.29 0.7 0.11 0.29 0.72 30 74 170 1,4‐Dichlorobenzene 14 36 85 17 42 99 120000(4200) 120000(9900) 120000(21000) 1,2,3‐Trichlorobenzene 0.41 1 2.5 0.41 1 2.5 100 240 580 1,2,4‐Trichlorobenzene 0.73 1.8 4.2 0.73 1.8 4.2 210 520 1200 1,3,5‐Trichlorobenzene 0.092 0.23 0.55 0.092 0.23 0.55 22 54 130 1,2,3,4‐Tetrachlorobenzene 6 14 33 6.8 16 38 6100(1700) 6100(3000) 6100(4300) 1,2,3,5‐Tetrachlorobenzene 0.2 0.51 1.2 0.2 0.52 1.2 230(47) 220(110) 230 1,2,4,5‐Tetrachlorobenzene 0.17 0.41 0.94 0.2 0.52 1.1 88(41) 88(70) 94 Pentachlorobenzene 3.8 8.2 14 7.4 13 20 850(620) 850(760) 850(820) Hexachlorobenzene 0.61(0.45) 0.97(0.83) 1.2 1.6(0.76) 1.6(1.1) 1.6(1.5) 57(47) 57(52) 57(55) Carbon Disulphide 0.045 0.094 0.2 0.045 0.094 0.2 12 25 56
Note: Parentheses for raw value prior to correction for saturated vapour pressure limit, excepting: (*) Set on presumption of free‐phase with vapour corrected value in parentheses. (~) Based on acute health. AECOM Version 1 15 October 2009
APPENDIX A.
AECOM Generic Assessment Criteria - Modelling Assumptions
The AECOM Generic Assessment Criteria (AGAC) have been derived to be used as an initial screening tool. They are based on a number of assumptions to produce criteria applicable to typical development sites without being overly conservative. The assumptions and the rationale behind them are detailed below.
Soil Guideline Values (SGVs) and AGACs are appropriate for screening chemical concentrations for the purpose of obtaining Planning Consent, but are not appropriate for Part IIa determination or remediation standards.
1. Calculated risk levels AGACs are calculated for a minimal level of risk in line with SGVs with the current exception of arsenic, which follows alternative SGV guidance. Therefore concentrations found below AGACs are not normally considered any further.
2. Soil Guideline Values and soil type SGVs (published before September 2009) have been reproduced using CLEA1.04 software using the assumptions in the corresponding TOX and SGV reports. However SGVs have been calculated using a SOM of 6% which is not generally representative of contamination samples taken from development sites. AGACs for chemicals with SGVs have been recalculated with a SOM of 1%. New SGVs are also calculated for a “sandy loam” rather than “sandy soil” as in the case of the withdrawn SGVs. AGACs are calculated for a sandy soil in order to provide a conservative initial screen.
3. Verification and Robustness In order to have confidence in the AGACs produced, initially CLEA 1.04 was used to reproduce the newly published but limited number of SGVs. Further cross checking has been undertaken on the values generated by the CLEA 1.04 model by undertaking repeat runs and cross checking results against values produced by our in-house software program FM-CLaRAT2. AECOM is also a contributor to the LQM CIEH and EIC working groups who have and are seeking to publish authoritative peer reviewed screening values for contaminants which currently do not have SGV’s. Consequently the invaluable knowledge about the limitations of the model and how it works gained as part of this process has been utilised fully in producing the AGACs. Details of sensitivity analyses undertaken in connection with land use scenarios are described below. It is noted that CLEA 1.05 was released in September 2009 with primarily cosmetic changes and the addition of dioxins and dioxin-like PCBs; the release of which has not resulted in the existing published SGV’s being withdrawn. Consequently the AGACs produced using CLEA 1.04 (which do not include values for dioxins and dioxin-like PCBs) are still considered valid as an initial screen.
4. Receptor characteristics AGACs are calculated for standard CLEA land use receptors as follows:
Land Use Standard Receptor Residential with home grownproduce* Female 0-6yrs Residential without home grownproduce* Female 0-6yrs Commercial Female 16-65yrs *Female 0-75yrs in the case of Cadmium (see Cadmium SGV)
Page 1 of 3
AECOM Version 1 15 October 2009
5. Assumptions for buildings Contamination is assumed to be at a depth of 0.65m below ground level underneath buildings and at surface level external to buildings in line with assumptions for SGVs. Default gas ingress rates and effective air permeability are also assumed for each building type.
Residential A sensitivity study of CLEA1.04 residential building types has been carried out to determine the most appropriate setting for calculation of AGACs. It transpires that the most sensitive residential building type by a significant margin is a bungalow. The building type used for SGVs is a small terraced house which is appropriate for high density low cost housing on brownfield sites. The building type used for AGACs is a small terraced house in order to avoid too high a degree of conservatism for most developments.
Commercial A sensitivity study of standard CLEA1.04 commercial buildings indicates that pre- 1970s buildings are more sensitive to contamination than modern buildings. For Planning purposes however it is more appropriate to model risk in modern buildings and so AGACs are based on a post-1970 office, which is generally slightly more sensitive than a post-1970 warehouse.
6. Indoor vapour pathway correction factor The calculation of petroleum hydrocarbon ingress to buildings for the AGACs utilises a “sub-surface soil to indoor air correction factor” of 10 in line with DEFRA guidance on BTEX SGVs. This correction arises from a discrepancy found between observed and predicted hydrocarbon concentrations using the Johnson-Ettinger model in the UK. It is found that indoor concentrations of hydrocarbons are typically at least an order of magnitude lower in practice compared with theory.
As it is unclear whether this discrepancy is due to a difference in the typical foundation design employed in the UK and USA, or results from chemical specific attenuation of contaminants through breakdown, this factor is not included for other species, e.g. elemental mercury and chlorinated hydrocarbons.
7. Soil Vapour Limit Risk to human health from soil vapour calculated by CLEA1.04 rises linearly with increasing soil concentration despite the physical limits to concentration in air set by the maximum vapour pressure. A manual iterative procedure using the methodology detailed in the CLEA1.04 Guidance has been used to correct AGAC to take account of the upper limit of vapour concentration. Calculations have been cross-checked with FM-CLaRAT2 which corrects for the soil vapour concentration limit automatically.
8. Saturation Limit Plant uptake may be limited by the concentration of the chemical in the soil pore water. Calculation of GACs using the saturation limit would be a laborious task especially where vapour pressure also limits uptake. Given that plant uptake is only present in one of the current AECOM generic scenarios and the reservations expressed by the Environment Agency as to whether saturation is always limiting, the current AGACs do not apply an upper limit to plant uptake based on saturation limit. FM-CLaRAT2 checks have been performed without using the saturation limit in order to maintain consistency with CLEA1.04.
Page 2 of 3
AECOM Version 1 15 October 2009
9. Free-phase hydrocarbon limit SGVs for BTEX compounds have been limited by DEFRA to the concentration which would saturate either the pore fluid or the soil vapour, whichever concentration is lower. Although DEFRA’s reason for capping SGVs is protection of human health, no mechanism is given for the increased risk from free-phase hydrocarbons. Heavy hydrocarbons are relatively insoluble and so general adoption of this rule would result in very low GAC values, despite the free-phase being immobile, e.g. solid or bound within the soil particles. Therefore AGAC values have with the exception of BTEX been calculated without this free-phase constraint.
10. Nickel screening values DEFRA guidance for nickel suggests that risk via inhalation and oral pathways is not addiditive. AGAC for nickel uses the lower of the inhalation and oral assessment criteria in accordance with the nickel SGV methodology
11. Asbestos, Volatile Organic Compounds (VOCs) Semi-volatileOrganic compouns(SVOCs) and Polychlorinated biphenols (PCBs) The analytical reporting limit for VOCs, SVOCs and PCBs has been adopted as an initial screen where no AGAC is available as set out in the table below. The presence of asbestos fibres identified within any of the samples has been adopted as a screen for assessing asbestos.
Parameters Reporting Limit for individual compounds (minimum required) VOCs 0.1-5ug/kg (10ug/kg) SVOCs* 100ug/kg (100ug/kg) PCBs 1ug/kg (3ug/kg) * 12. Cyanide The current CLEA methodology only assesses the chronic risks to human health. Cyanide may also pose an acute risk to human health. Where cyanide is present above the reporting limit of 1mg/kg then the risk will be considered on a site specific basis.
Page 3 of 3