Site Investigation Including Quantitative Risk Assessment

Prepared by: Norfolk Partnership Laboratory, County Hall, Martineau Lane, Norwich, Norfolk, NR1 2SG

Telephone (01603) 222416

Site Investigation Including Quantitative Risk Assessment Stanfield House, Lynn Road

Swaffham, Norfolk JBCO0003

September 2015 Client: J Ball 2 Snaefell Park Sheringham Norfolk NR26 8GZ

T:\HMLAB\PROJECTS\EXTERNAL\JBCO0003 Swaffham, Stanfield House - additional SI\Reports\Stanfield House Swaffham StageII QRA report.doc Page 2 of 37

i) Contents

1.0 Introduction ............................................................................................................. 5

1.1 General ................................................................................................................... 5

1.2 Report objectives .................................................................................................... 6

1.3 Site location ............................................................................................................ 6

2.0 Review and summary of previous report .............................................................. 7

2.1 Desk Study and risk assessment Stage I LAB000336 ............................................ 7

2.2 Supplementary Gas Investigation at Stanfield House Swaffham 23/10/2009 ......... 7

2.3 Supplementary Gas Investigation at Stanfield House Swaffham 25/02/2010 ......... 7

2.4 Consultations with the local authority ...................................................................... 7

2.5 Consultations with the Environment Agency ........................................................... 7

3.0 Identification of potential contaminants of concern and source areas ............ 10

4.0 Risk Assessment .................................................................................................. 11

4.1 Conceptual Model ................................................................................................. 11

4.2 Sources of contamination ...................................................................................... 11

4.3 Pollution Linkages ................................................................................................. 12

4.4 Receptors .............................................................................................................. 13

4.5 Description of possible pollutant linkages for controlled waters ............................ 19

4.6 Identification of potentially unacceptable risks to controlled waters ...................... 19

4.7 Discussion of uncertainties and gaps in information ............................................. 19

5.0 Recommendations for site investigation ............................................................ 20

6.0 Site Investigation .................................................................................................. 21

6.1 Works undertaken ................................................................................................. 21

6.2 Site Investigation Strategy .................................................................................... 21

6.3 Site Sampling Strategy .......................................................................................... 21

6.4 In-situ and Geotechnical Testing ........................................................................... 21

6.5 Fieldwork ............................................................................................................... 21


7.0 Analytical Strategy ................................................................................................ 22

7.1 Soil ........................................................................................................................ 22

8.0 Investigation Results ........................................................................................... 23

8.1 Ground conditions ................................................................................................. 23

8.2 Groundwater conditions ....................................................................................... 24

8.3 Geoenvironmental test results summary ............................................................... 24

8.4 Contamination ....................................................................................................... 24

9.0 Quantitative Risk Assessment ............................................................................. 27

9.1 Risk Assessment Objectives ................................................................................. 27

9.2 Proposed Development ......................................................................................... 27

9.3 Revised Conceptual Model ................................................................................... 27

9.4 Risk assessment rationale .................................................................................... 27

9.5 Exposure scenarios............................................................................................... 28

9.6 Assessment criteria ............................................................................................... 33

9.7 Constraints and limitations .................................................................................... 33

9.8 Risk to controlled waters ....................................................................................... 33

9.9 Effects on Human Health ...................................................................................... 33

9.10 Effects on Buildings and services ......................................................................... 34

9.11 Uncertainties ......................................................................................................... 34

9.12 Risk Evaluation ..................................................................................................... 34

10.0 Recommendations ................................................................................................ 35

11.0 References ............................................................................................................. 36

Appendices Appendix A Site location plans

Appendix B Window sample location plan Appendix C Window sample logs

Appendix D Contamination test reports

Appendix E Proposed Site Layout plan

Appendix F Breckland Council correspondence


(ii) Distribution

J Ball Norfolk Partnership Laboratory

2 copies 1 copy


1.0 Introduction

1.1 General

This investigation was carried out on land to the north of C562 Lynn Road, Swaffham, (OSGR 580985/309353). Swaffham is located approximately 41 kilometres to the west of Norwich City centre. The study area is approximately 1 kilometre to the west of Swaffham town centre. This report by Norfolk Partnership Laboratory was instigated at the request of Mr J Ball after acceptance of the quotation number 2741 dated 14 August 2015. Norfolk Partnership Laboratory provides a service within the Highways and Transport Group of the Community and Environmental Services Department of Norfolk County Council. This report should be read in conjunction with a previously issued reports by Norfolk Partnership Laboratory (NPL). 1) Desk Study and Risk Assessment, Stanfield House, Lynn Road, Swaffham,

Norfolk reference number LAB000336, dated November 2008

2) Supplementary Gas Investigation at Stanfield House Swaffham reference JBCO0001 dated 23 October 2009.

3) Supplementary Gas Investigation at Stanfield House Swaffham reference

JBCO0002 dated 25 October 2010 It should also be noted that the development site boundary in relation to the current planning application reference 3PL/2014/0125/F has been altered (reduced) when compared to the original application 3PL/2009/0331/F. Stanfield House is to remain out of the development. A garden has been marked out and fenced off to accompany this property. This investigation was carried out in accordance with NHBC Standards, Chapter 4.1 Land Quality - managing ground conditions, January 2013 edition with subsequent amendments. In addition a risk assessment has been carried out to the requirements of The Environmental Protection Act Part IIA. This report is inclusive of a full Envirocheck report, Envirocheck historical maps, historical land use and a geological report. In addition, consideration is given to the health and safety of construction workers and subsequent residents that may be affected due to any soil contamination. It is proposed to develop the site for residential use. Opinions and interpretations expressed herein are outside the scope of UKAS accreditation. Although every effort has been made to give a true assessment of the condition of the site, it is possible that different ground conditions or contamination may exist in parts of the site not investigated.


1.2 Report objectives

The main objective of this report is to respond to queries raised by Breckland Council in a letter ref 141103 dated 4 March 2014. In addition report goes on to assess contamination sources, pathways and receptors, and to ascertain whether any contamination is present either within the site boundaries or just outside the site. The report also assesses the extent to which human health, buildings and services and controlled waters may be affected. If contamination is thought likely to be present, recommendations will be made to ascertain the level of contamination and if these levels are within allowable limits. The report also provides geotechnical information regarding the underlying strata.

1.3 Site location

This site is located on land to the north of C562 Lynn Road, Swaffham, (OSGR 580985 / 309353). Swaffham is located approximately 41 kilometres to the west of Norwich City centre. The study area is approximately 1 kilometre to the west of Swaffham town centre. The site is approximately 65 metres above Ordnance Survey Datum and 1.28 hectares in area. A site location plan is given in Appendix A.

1.4 Site layout

The site is rectangular in shape although the northern boundary tapers to the eastern side. The site is approximately 1.28 hectares in area and 65 metres above Ordnance Survey Datum.

1.5 Planning application

The site is subject to the planning conditions of Breckland Council reference:- 3PL/2014/0125/F.


2.0 Review and summary of previous report

2.1 Desk Study and risk assessment Stage I LAB000336 This report generally recommended a series of holes be drilled to determine the extent of any Made Ground within the site. Installations should also be placed in a number of these holes to measure the levels of ground gas from the on-site Made Ground and the off-site infilled land. In addition a sample should be obtained from the area of the heating oil tank situated at Stanfield House. WS9 will be positioned close to the above ground heating oil tank to the rear of the property and Speciated TPH testing will be undertaken from the retrieved samples.

2.2 Supplementary Gas Investigation at Stanfield House Swaffham 23/10/2009 This report included the data from the boreholes and ground gas monitoring results to date. Made Ground was recorded predominantly in the far northern corner of the site.

2.3 Supplementary Gas Investigation at Stanfield House Swaffham 25/02/2010 This report included the data collect during the ground gas monitoring. The report concluded that the site required a negligible gas regime and requires no gas protection measures.

2.4 Consultations with the local authority

NPL were forwarded a letter from Breckland Council ref 141103 dated 4 March 2014. This was issued as a response to the revised planning application 3PL/2014/0125/F. This letter required supplementary work to be carried out on the site. This work is summarised below 1) A revised desk study and walkover survey would be required 2) Further investigation of the Made Ground area including chemical analysis to

determine the risk posed by the Made Ground. 3) Further ground gas installations and readings to determine if the original findings

were robust. 4) Investigation of heating oil tank adjacent to Stanfield House. 5) Chemical analysis to be carried out on near surface soils to determine its

suitability for the proposed development.

2.5 Consultations with the Environment Agency

No consultations have taken place between the Environment Agency and NPL. The site poses a very low risk to controlled waters.


View east towards plot 7 & 8.

View of Stanfield House now separated from site. Heating oil tank on northern wall of house.


View west, WS4 off site on right. Site starts at fencing.

View south


3.0 Identification of potential contaminants of concern and source areas

From the original walkover survey and desk study it was ascertained that there are a number of potential contamination sources associated with the site. A number of potential pollutants are identified in the Department of the Environment Industry profiles. The profile for “Waste recycling treatment and disposal sites: landfills and other waste treatment or waste disposal sites” and the profile for “Railway Land” was considered partially relevant to this site. After visual examination of the site the following have been identified as potential pollution sources. Contamination from historical landfill in north west corner. Landfill gases migrating from historical landfill to the west.

Above ground heating oil tank.

Naturally occurring gases from underlying chalk deposit.

Contamination from Railway Land to the north. As requested by Breckland Council a new walkover was carried out across the revised site area included in the present planning application. The potential risks identified have been listed below in order of potential risk. Contamination from historical landfilled ground in north west corner. Ground gas from historical landfilled ground in north west corner. Landfill gases migrating from historical landfill to the west.

Naturally occurring gases from underlying chalk deposit.

Near surface contamination

Contamination from Railway Land off site to the north. Off-site over ground heating oil tank. These have a variety of potential pollution linkages.


4.0 Risk Assessment

4.1 Conceptual Model The known or perceived sources of contamination and pollution linkages are assessed in this section. The conceptual model is realised here in tabulated form.

4.2 Sources of contamination

Historical land use indicates that there has been some infilling of land within the site. A number of potential pollutants are identified in the Department of the Environment Industry profiles. The profile for “Waste recycling treatment and disposal sites: landfills and other waste treatment or waste disposal sites” and the profile for “Railway Land” was considered partially relevant to this site. After the recent walkover and visual examination of the site and reviewing information from the previous desk study the following have been identified as potential pollution sources.

a) Contamination from historical landfilled ground in north west corner.

b) Ground gas from historical landfilled ground in north west corner.

c) Landfill gases migrating from historical landfill to the west.

d) Naturally occurring gases from underlying chalk deposit. e) Near surface contamination

f) Contamination from Railway Land off site to the north. g) Off-site over ground heating oil tank

These have a variety of potential pollution linkages.


4.3 Pollution Linkages Each of the potential contaminants may have a number of pollution linkages. Each of these linkage types has a number of potential pathways.

i) Surface soil linkages

a) Direct contact ingestion or absorption b) Indirect contact ingestion or absorption c) Leaching to groundwater

ii) Subsurface soil linkages a) Direct contact ingestion or absorption b) Indirect contact ingestion or absorption c) Leaching to groundwater

iii) Surface water linkages a) Direct contact ingestion or absorption b) Indirect contact ingestion or absorption c) Percolation to groundwater

iv) Groundwater linkages a) Direct contact ingestion or absorption b) Indirect contact ingestion or absorption

v) Airborne linkages

a) Vapour intrusion into confined / indoor spaces b) Inhalation or absorption of particulates c) Inhalation or absorption of volatile compounds


4.4 Receptors A number of potential receptors exist. These can be broadly grouped as: i) Construction Worker ii) Future Resident iii) Trespasser iv) Local population v) Flora and fauna vi) Buildings vii) Surface Water viii) Groundwater For each source, the linkage type, pathway and potential receptors can be identified. A level of risk if no action is taken can then be assigned to each of these linkages. The level of risk has been divided into six categories as follows Very Low Risk – Considered very unlikely or impossible Low Risk – Considered conceivable but unlikely Medium Risk – Considered possible but unusual High Risk – Considered probable i.e. about 50% chance Very High Risk – Considered that it is to be expected to happen Certainty – Considered that it will happen Note: These risks are related to the probability of an event happening. They do not relate to the severity of the effects on human health or flora and fauna nor the financial consequences if the event should happen.


4.4.1 Contamination from historical landfilled ground in north west corner

Linkage type Pathway Receptor Risk Surface soil linkage

Direct contact ingestion or absorption

Construction Worker Medium

Resident Medium Trespasser Medium Flora and fauna Medium Direct contact Surface water Medium Indirect contact ingestion

or absorption Resident Medium

Subsurface soil linkage


Construction Worker High

Resident High Flora and fauna High Direct contact Buildings and services High Indirect contact ingestion

or absorption Resident High

Leaching to groundwater Local population Low Flora and fauna Low Construction Worker Low Groundwater Low Surface water linkage



Resident Medium Trespasser Low Flora and fauna Low Direct contact Buildings and services Low Surface water Low Percolation to

groundwater Local population Low

Flora and fauna Low Groundwater Low Groundwater linkage


Construction Worker Low

Local population Low Flora and fauna Low Direct contact Buildings and services Low Groundwater Low Indirect contact ingestion

or absorption Local population Low

Flora and fauna Low Airborne linkage Inhalation of particulates Construction Worker Low Resident Low Trespasser Low Flora and fauna Low Local population Low Inhalation of volatile

compounds Construction Worker Low

Resident Low Trespasser Low Flora and fauna Low Local population Low Vapour intrusion into

indoor spaces Resident Low

Local population Low


4.4.2 Ground gas from historical landfilled ground in north west corner.

Linkage type Pathway Receptor Risk Airborne linkage Inhalation of particulates Construction Worker Low Resident Low Trespasser Low Local population Low Inhalation of volatile


Resident Low Trespasser Low Local population Low Vapour intrusion into

indoor spaces Resident Medium

Local population Low 4.4.3 Landfill gases migrating from historical landfill to the west.





Local population Low 4.4.4 Naturally occurring gases from underlying chalk deposit.







4.4.5 Near surface contamination




Resident Medium Trespasser Low Flora and fauna Low Direct contact Surface water Low Indirect contact ingestion

or absorption Resident Low




Resident Low Flora and fauna Low Direct contact Buildings and services Low Indirect contact ingestion





Resident Medium Trespasser Medium Flora and fauna Medium Direct contact Buildings and services Medium Surface water Low Percolation to













4.4.6 Contamination from Railway Land off site to the north.




Resident Low Trespasser Low Flora and fauna Low Direct contact Surface water Low Indirect contact ingestion




Construction Worker Very Low

Resident Very Low Flora and fauna Very Low Direct contact Buildings and services Very Low Indirect contact ingestion

or absorption Resident Very Low

Leaching to groundwater Local population Very Low Flora and fauna Very Low Construction Worker Very Low Groundwater Very Low Surface water linkage



Resident Low Trespasser Low Flora and fauna Low Direct contact Buildings and services Low Surface water Low Percolation to







Flora and fauna Low Airborne linkage Inhalation of particulates Construction Worker Very Low Resident Very Low Trespasser Very Low Flora and fauna Very Low Local population Very Low Inhalation of volatile

compounds Construction Worker Very Low

Resident Very Low Trespasser Very Low Flora and fauna Very Low Local population Very Low Vapour intrusion into

indoor spaces Resident Very Low

Local population Very Low


4.4.7 Off-site over ground heating oil tank




Resident Low Trespasser Low Flora and fauna Low Indirect contact ingestion





Resident Low Flora and fauna Low Indirect contact ingestion





Resident Low Trespasser Low Flora and fauna Low Percolation to





Local population Low Flora and fauna Low Indirect contact ingestion








4.5 Description of possible pollutant linkages for controlled waters According to the Regional Hydrogeology Map of Northern East Anglia, the Upper Chalk is the principle aquifer for the area. The estimated minimum hydrostatic level of the Upper Chalk water table in the vicinity of the site is approximately between 20 and 30 metres above Ordnance Survey Datum. The site is approximately between 65 metres above Ordnance Survey Datum. The groundwater table is therefore between 35 and 45 metres below existing ground level.

4.6 Identification of potentially unacceptable risks to controlled waters

There is a low to very low risk that various contaminants identified in the risk assessment could migrate to the regional groundwater table.

4.7 Discussion of uncertainties and gaps in information It is possible that different conditions exist in parts of the site that have not been investigated.


5.0 Recommendations for site investigation

Based upon the information contained herein it is recommended that a site investigation and quantitative risk assessment is carried out.

From this preliminary risk assessment it is recommended that a site investigation comprising of a number of window sample holes is undertaken. Judgmental sampling in accordance with BS 10175:2011 clause 7.7.2.2 and non targeted sampling in accordance with BS 10175:2011 clause 7.7.2.3 should be carried out. NPL recommends that nine window sample holes are drilled to a maximum depth proving any Made Ground encountered. Installations should be placed in seven locations across the site to monitor potential groundwater and ground gas. In addition the previously installed ground gas monitoring holes would be checked and repaired if necessary prior to continued monitoring. The investigative locations should be positioned in areas identified in the risk assessment and in the areas that visually appear to have the most potential for contamination.


6.0 Site Investigation

6.1 Works undertaken

On the 21 August 2015, nine window sample holes were drilled to a maximum depth of 8.00 metres. Seven of the window sample holes had installations placed in them to monitor groundwater and potential ground gas. All original boreholes with ground gas monitoring installations were inspected, maintained to a standard that robust readings could be taken.

The locations of all these holes are shown on the plan in Appendix B.

6.2 Site Investigation Strategy

The site investigation was to target the areas of potential contamination identified by the previous report.

Hole ID Reason for location

WS6 Ground gas monitoring – Surface soils analysis WS7 Ground gas monitoring – Surface soils analysis WS8 Ground gas monitoring – Surface soils analysis WS9 Ground gas monitoring – Surface & Made Ground soils analysis

WS10 Ground gas monitoring – Surface soils analysis WS11 Ground gas monitoring WS12 Ground gas monitoring – Made Ground soils analysis WS13 Surface soils analysis WS14 Site investigation

6.3 Site Sampling Strategy

A number of disturbed samples were taken from the window sample holes in accordance with BS 5930:1999. The number and depths of these samples along with the details of thickness of strata encountered are set out in Appendix C of this report.

6.4 In-situ and Geotechnical Testing

No in-situ or geotechnical testing was undertaken in this investigation.

6.5 Fieldwork On the 21 August 2015, nine window sample holes were drilled to a maximum depth of 8.00 metres. Three subsequent site monitoring visits were carried out post the drilling works.


7.0 Analytical Strategy

Based upon the reasons for carrying out each investigative hole as identified in Section 6.4 the following samples were tested for the parameters shown.

7.1 Soil

Location Depth (m) Tests WS6 0.1 Suite SB WS7 0.2 Suite SB WS8 0.1 Suite SB WS9 0.3 Suite SB WS9 0.6 Suite SB

WS10 0.3 Suite SB WS12 0.6 Suite SB, Speciated TPH WS13 0.2 Suite SB

Suite SB = General contamination suite including testing for: Total Sulphate, Boron, Water Soluble, Arsenic, Cadmium, Chromium III, Chromium VI, Copper, Lead, Mercury, Nickel, Selenium, Zinc, Acid Soluble Sulphide, Phenols (Monohydric), Total Cyanide, Elemental Sulphur, pH Value, PAH Total, Speciated PAH, Soil Organic Matter (SOM).


8.0 Investigation Results

8.1 Ground conditions

8.1.1 Surface Deposits

Topsoil was recorded as the surface deposit in all window sample holes. This material was seen to be brown in colour and silty in nature. The deposit recovered in WS12 was seen to include brick fragments. Thicknesses ranged from 0.20 metre in WS8 & WS12 up to 0.55 metre in WS11. In WS10 two layers of Topsoil were noted. The surface deposit from ground level to 0.20 and a secondary layer from 0.50 to 0.80 metre. In between this Topsoil material a thin layer of brown silty, clayey, slightly gravelly fine and medium sand was recorded. Made Ground Made Ground was recorded beneath the Topsoil at a depth of 0.20 metre in WS12 and beneath the silty fine sand at 0.50 metre in WS9. This material was found to be bedded dark grey and black crushed asphalt, ash and clinker with up to cobble size brick, concrete and flint becoming dark greyish brown fine and medium sand with a little fine medium and coarse brick and flint. Occasional ceramics, glass and whole red bricks.

The thickness of the Made Ground ranged from 7.00 metres in WS9 up to 7.15 metres in WS12. The base of the Made Ground was proven in all window sample holes at a maximum depth of 7.50 metres. More detail can be found on the window sample logs in Appendix C.

8.1.2 Lowestoft Formation

The Lowestoft Formation was encountered in all window sample holes with the exception of WS12. This material was found to be a light brown orangey brown silty fine sand with a little fine and medium flint gravel. The deposit was revealed at depths ranging from 0.20 metre in WS8 up to 0.80 metre in WS10. The base of the deposit was proven in all window sample holes at a maximum depth of 2.20 metres in WS8 with the exception of WS13 where the deposit was not proven at the termination depth of 3.00 metres.

8.1.3 Upper Chalk

The Upper Chalk was encountered in all holes with the exception of WS13. This deposit comprised a white chalk, weak to moderately weak, some manganese staining some silt sized comminuted chalk infilling joints and fissures. Grade III


MB3. The deposit was revealed at depths ranging from 0.1.20 metres in WS14 up to 0.80 metre in WS10. The base of the deposit was proven in all window sample holes at a maximum depth of 7.50 metres in WS9 and 12. The deposit was not proven in any window sample holes at a maximum depth of 8.00 metres.

8.2 Groundwater conditions

No groundwater was found during the investigation.

8.3 Geoenvironmental test results summary

The samples indicated in Section 7.0 were sent to Envirolab Cheshire for analysis. Envirolab is a UKAS accredited laboratory, No.1247. These samples were tested for the contaminants of concern noted in sections 7.1 above. The test results are included in Appendix D.

8.4 Contamination 8.4.1 Soil

All the results including the Made Ground samples were found to be below the C4SL’s, SGV's, S4UL’s Atkins ATRISK guidance threshold values when compared to the most stringent criteria for residential with home grown produce using 1% SOM.

8.4.2 Naturally occurring gases

Although tested, no flow or methane was recorded. Please note WS’s1 – 5 were installed during the original investigation but have been monitored as part of this investigation.

02/09/2015

Location Pressure (mb)

O2 (%)

C02 (%)

CH4 (%)

Flow (l)

WS1 1007 19.4 1.0 0.0 0.0 WS2 1007 16.9 4.3 0.0 0.0 WS3 1007 14.7 6.4 0.0 0.0 WS4 1007 15.2 4.2 0.0 0.0 WS5 1007 18.5 3.4 0.0 0.0 WS6 1007 18.5 2.7 0.0 0.0 WS7 1007 17.3 4.0 0.0 0.0 WS8 1007 18.2 3.7 0.0 0.0 WS9 1007 17.5 3.0 0.0 0.0

WS10 1007 18.6 2.5 0.0 0.0 WS11 1007 17.6 4.0 0.0 0.0 WS12 1007 20.7 0.0 0.0 0.0


11/09/2015 Location Pressure

(mb) O2 (%)

C02 (%)

CH4 (%)

Flow (l)


WS10 1007 19.1 2.1 0.0 0.0 WS11 1007 19.6 1.7 0.0 0.0 WS12 1007 20.6 0.0 0.0 0.0

17/09/2015

Location Pressure (mb)

O2 (%)

C02 (%)

CH4 (%)

Flow (l)


WS10 986 17.9 2.4 0.0 0.0 WS11 986 18.3 2.3 0.0 0.0 WS12 986 20.4 0.0 0.0 0.0

Carbon Dioxide

Historical monitoring of the site on eleven occasions revealed a maximum Carbon Dioxide reading of 4.0% from WS1 located central to the historical landfill site.

The maximum recorded Carbon Dioxide combining historical records with the most recent visits is 6.4% in WS3. The maximum recorded Carbon Dioxide reading was 6.8% in WS18 on 02/09/2015. Following CIRIA report C665; using Table 8.7 and the worst case reading of 6.8% CO2, the site can be classified as NHBC traffic light situation AMBER1. This is indicative of a low to intermediate gas regime which requires low level gas protection measures which requires a membrane and sub-floor void to create a permeability contrast to limit the ingress of gas in to buildings. Gas protection measures should be as prescribed in BRE report 414. Ventilation of the subfloor void should facilitate a minimum of one complete volume change per 24 hour period.


Methane

No Methane was recorded during the historical or this present monitoring period.


9.0 Quantitative Risk Assessment

9.1 Risk Assessment Objectives

The objective of the quantitative risk assessment is to revisit the preliminary risk assessment in the light of information obtained during the site investigation and thus reassess the validity of the model.

9.2 Proposed Development

It is proposed to develop the site for residential use.

9.3 Revised Conceptual Model Referring back to the original conceptual model in Section 4.0 the following potentially contaminative linkages were present.

a) Contamination from historical landfilled ground in north west corner.

b) Ground gas from historical landfilled ground in north west corner.

c) Landfill gases migrating from historical landfill to the west.

d) Naturally occurring gases from underlying chalk deposit. e) Near surface contamination

f) Contamination from Railway Land off site to the north. g) Off-site over ground heating oil tank

These have a variety of potential pollution linkages.

9.4 Risk assessment rationale

Where available levels of potential contaminants were compared with C4SL’s, SGV’s and LQM/CIEH S4UL’s to assess human health risk. Where these were not available Atkins ATRISK and threshold values were used. To assess the risk to buildings and services the WRAS documentation and BRE Special Digest 1 were used. These are specialist documents that focus on a particular target.


9.5 Exposure scenarios 9.5.1 Contamination from historical landfilled ground in north west corner



























9.5.2 Ground gas from historical landfilled ground in north west corner.





Local population Low 9.5.3 Landfill gases migrating from historical landfill to the west.





Local population Low 9.5.4 Naturally occurring gases from underlying chalk deposit.







9.5.5 Near surface contamination



























9.5.6 Contamination from Railway Land off site to the north.








Construction Worker Very Low

Resident Very Low Flora and fauna Very Low Direct contact Buildings and services Very Low Indirect contact ingestion

or absorption Resident Very Low

Leaching to groundwater Local population Very Low Flora and fauna Very Low Construction Worker Very Low Groundwater Very Low Surface water linkage










Flora and fauna Low Airborne linkage Inhalation of particulates Construction Worker Very Low Resident Very Low Trespasser Very Low Flora and fauna Very Low Local population Very Low Inhalation of volatile

compounds Construction Worker Very Low

Resident Very Low Trespasser Very Low Flora and fauna Very Low Local population Very Low Vapour intrusion into

indoor spaces Resident Very Low

Local population Very Low


9.5.7 Off-site over ground heating oil tank




Resident Low Trespasser Low Flora and fauna Low Indirect contact ingestion





Resident Low Flora and fauna Low Indirect contact ingestion





Resident Low Trespasser Low Flora and fauna Low Percolation to





Local population Low Flora and fauna Low Indirect contact ingestion






Local population Low No testing was carried out in this area as the tank now off site and is the supply to the original Stanfield House. The tank is located adjacent to the northern wall of the property. No sign of leakage was noted during the walkover survey.


9.6 Assessment criteria

The assessment criterion used is for residential with the consumption of home grown produce land use produce with 1% soil organic matter.

C4SL’s, SGV’s and LQM/CIEH S4UL’s and Atkins ATRISK models were used to assess human health risk and determine allowable values for any contaminants present. To assess the risk to buildings and services the WRAS documentation and BRE Special Digest 1 were used. These are specialist documents that focus on a particular target.

9.7 Constraints and limitations

The CLEA model is limited to published data. These assessing criteria only apply to human health and do not assess risk to groundwater. Atkins ATRISKsoil SSV data was derived to use where CLEA guidance was not available. ATRISKsoil SSV was derived using toxicological data inputted into BP RISC 4.0. The WRAS, CIRIA and BRE documents are specific to the target receptor.

9.8 Risk to controlled waters

According to the Regional Hydrogeology Map of Northern East Anglia, the Upper Chalk is the principle aquifer for the area. The estimated minimum hydrostatic level of the Upper Chalk water table in the vicinity of the site is approximately between 20 and 30 metres above Ordnance Survey Datum. The site is approximately between 65 metres above Ordnance Survey Datum. The groundwater table is therefore between 35 and 45 metres below existing ground level.

A low to very low risk to controlled waters has been deemed appropriate for this site. This is due to the very low levels of contamination recorded during this and the previous investigation.

9.9 Effects on Human Health

Testing has indicated that the natural strata and the Made Ground underlying the site poses a low to very low risk to the human health issues of the end user. Further mitigation measures will be discussed in Section 10. If these recommendations are included with the development low risk will remain.


9.10 Effects on Buildings and services

The site generally poses a low risk to buildings and services. Ground gas poses a medium risk to the proposed buildings and residents. Mitigation measures discussed in Section 10.0 will negate this medium risk to a low risk.

9.11 Uncertainties

There is a risk that contamination may exist in areas not investigated.

9.12 Risk Evaluation

With current knowledge this site generally represents a low potential risk to controlled waters, to human health and to buildings and services with the exception of the medium risk posed by the ground gas. Following the inclusion of the recommendations in Section 10.0 a low risk will remain.


10.0 Recommendations

No further intrusive work is deemed necessary on this site. The latest ground gas monitoring has confirmed that ground gas protection measures are required on the site. Following CIRIA report C665; using Table 8.7 the site can be classified as NHBC traffic light situation AMBER1. This is indicative of a low to intermediate gas regime which requires low level gas protection measures which requires a membrane and sub-floor void to create a permeability contrast to limit the ingress of gas in to buildings. Gas protection measures should be as prescribed in BRE report 414. Ventilation of the subfloor void should facilitate a minimum of one complete volume change per 24 hour period.

There is topsoil present on the site. Analysis has shown this material is suitable for re use in the residential garden areas. All gardens should have a minimum of 300mm of Topsoil. It should also be stressed that if any possibly contaminated material is encountered during the construction process, work shall cease and Breckland Council and Norfolk Partnership Laboratory should be informed immediately.


11.0 References DEFRA: Contaminated Land exposure assessment “CLEA Version 1.04 :2008" C4 SL’s Environment Agency: R&D Publication 20; Methodology for the derivation of remedial targets for soil and groundwater to protect water resources: 1999. Environment Agency: Technical advice to third parties on the pollution of controlled waters for part IIA: 2002. Environment Agency: Guidance on Requirements for Land Contamination Reports; July 2005. Environment Agency website. RAIS web site. WRAS Information and Guidance Note No 9-04-03, Issue 1: The Selection of Materials for Water Supply Pipes to be Laid in Contaminated Land: October 2002. CIRIA Report 149: Protecting Development from Methane: 1995. CIRIA C665 Assessing risks posed by hazardous ground gases to buildings, 2007. BRE Special Digest 1: Concrete in aggressive ground, 3rd Edition: 2005 Atkins Atrisk SSV's derived using CLEA Version 1.06. NHBC Standards January 2013. BS 1377: 1990; Soils for Civil Engineering Purposes BS 5930: 1999 incorporating amendment A2:2010; Code of practice for Site Investigations BS 10175: 2011; Investigation of potentially contaminated sites – Code of practice. LQM/CIEH S4ULs for Human Health Risk Assessment


Norfolk Partnership Laboratory

Site Investigation Section

This report was prepared under the direction of

the Laboratory Manager

R. J. Noakes

BSc. C Eng. M.I.C.E

Author of report

Geoenviromental Engineer

I D Brown

Date: 21/09/2015

Appendix A

HIG

HFI

ELD

AVE

NU

E

76

1

23

35

15

2

4

49

2

3

29

32

3

6

31

4

7

18

62

74

1

LOW ROAD

3a

2416

36

Stanfield House

17

25

46

33

13

68

3

2

1

1

2

3

5

6

7

8

910

11

12

13

14

15

16

1718

1920

21

22

23

2428

293031

32

34

36

3738

39 40 41

4647

4849505152

5354

55

5657

5859

60

45

676566

616263646869

92

8174

7973 72 717075767778

8082838485868788899091

93

96

97

98

99

100

101

102

103

104

105

106

107108 109

110

111

112

113

114

116 117

118

119

120121

123

124

125126

4243

44

115

122

2526

27

ICON CONSULTING HETHEL ENGINEERING CENTRE

CHAPMAN WAYHETHEL NORWICH

NR14 8FB01953 857669

L A N D O F F L Y N N R O A D S W A F F H A M N O R F O L K P R O P O S E D R E S I D E N T I A L D E V E L O P M E N T Project : 2213 Drawing 01/01 Date : October 2013 Drawing : Site Location - Site Layout Scale : 1:1500 - 1:500

ARCHITECTURALN

SITE CONTEXT - nts

SITE LOCATION SITE LAYOUT

showing site in relation to Swaffham centre

LYNN ROAD

LYNN ROAD

Existing trees retained Existing trees removed Proposed structure plantingProposed feature planting

PLOT 1

PLOT 2

PLOT 3

PLOT 4

PLOT 5

PLOT 6

PLOT 7

PLOT 8af

PLOT 9af

Access Road : block open-textured free-draining bitmac with surface dressingDrives : open-jointed block paving or natural aggregatePaths : buff flagsScreening : 1.8m screen walls / 1.8m timber fences and as plot division2.4m x 120m splays to secondary access

Dormant oil line

LOW ROAD

showing 2.4 x 120m splays to secondary access and extension to footpath

REVISED : March 2014 : Highway Officer amendments included. Footpath added : Plots 8 and 9 turning and parking increased.

Appendix B

WS09

WS10WS08

WS11

WS07

WS13 WS06

WS14

WS12

BIL 19/01/15

Tom McCabeExecutive Director of Communityand Environmental ServicesNorfolk County CouncilCounty HallMartineau LaneNorwich NR1 2SG

ORIGINAL SIZE: A4

Appendix C

NORFOLK PARTNERSHIP LABORATORY

Window SamplerLog

Sheet 1 of 1

Scheme Swaffham, Stanfield House Job No. JCBO0003 Borehole No. WS06

Carried out for J.Ball Date Started 21/08/2015 Date Finished 21/08/2015

Remarks: Type of Excavator Dando Terrier

Depth 3.00 Height

Co-ords 580998.00 - 309324.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description

Dark brown silty TOPSOIL.

Orangey brown gravelly fine SAND. Gravel is fine medium coarse flint.

Light brown and beige very gravelly fine medium SAND. Gravel is fine medium coarse sub angular sub rounded chalk and flint.

White CHALK. Weak to moderately weak. Some manganese staining. Some silt sized comminuted chalk infilling joints and fissures. Grade iii MB3.

End of Borehole at 3.00 m

LegendDepth

(m)

0.40

0.85

1.90

3.00

Sample

Type No.

FieldTests

Laboratory Tests

MC% LL PL MPI Org. CBR

U S01

U S02

U S03


Window SamplerLog

Sheet 1 of 1




Depth 3.00 Height

Co-ords 580959.00 - 309355.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description






LegendDepth

(m)

0.35

1.30

1.85

3.00

Sample

Type No.

FieldTests

Laboratory Tests


U S01

U S02

U S03


Window SamplerLog

Sheet 1 of 1




Depth 3.00 Height

Co-ords 580958.00 - 309388.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description


Brown gravelly fine medium SAND. Gravel is fine medium coarse flint. Rare brick fragment and chalk gravel. Orangey brown gravelly fine SAND. Gravel is fine medium coarse flint. Light brown and beige very gravelly fine medium SAND. Gravel is fine medium coarse sub angular sub rounded chalk and flint.



LegendDepth

(m)

0.20

0.60

0.80

2.20

3.00

Sample

Type No.

FieldTests

Laboratory Tests


U S01

U S02

U S03


Window SamplerLog

Sheet 1 of 1




Depth 8.00 Height

Co-ords 580936.00 - 309401.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description


Brown silty fine medium SAND. Rare fine medium coarse flint gravel.MADE GROUND. Bedded dark grey and black crushed asphalt and ash. Up to cobble size brick, concrete and flint. Dark greyish brown fine medium sand with little fine medium coarse brick and flint. Occasional ceramics, glass and whole red brick.



LegendDepth

(m)

0.30

0.50

7.50

8.00

Sample

Type No.

FieldTests

Laboratory Tests


U S01

U S02

U S03

D S04

D S05

U S06

U S07

U S08


Window SamplerLog

Sheet 1 of 1




Depth 3.00 Height

Co-ords 580940.00 - 309382.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description


MADE GROUND. Brown silty clayey slightly gravelly fine medium SAND. Gravel is fine medium coarse flint.Dark brown silty TOPSOIL.Light brown and beige very gravelly fine medium SAND. Gravel is fine medium coarse sub angular sub rounded chalk and flint.



LegendDepth

(m)

0.20

0.50

0.80

2.05

3.00

Sample

Type No.

FieldTests

Laboratory Tests


U S01

U S02

U S03


Window SamplerLog

Sheet 1 of 1




Depth 3.00 Height

Co-ords 580932.00 - 309324.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description






LegendDepth

(m)

0.55

1.25

2.15

3.00

Sample

Type No.

FieldTests

Laboratory Tests


U S01

U S02

U S03


Window SamplerLog

Sheet 1 of 1




Depth 8.00 Height

Co-ords 580962.00 - 309409.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description

Dark brown silty TOPSOIL. Occasional brick fragments.Stiff orangey brown and brown very sandy silty gravelly CLAY. Gravel is fine medium coarse flint.MADE GROUND. Bedded dark grey and black crushed asphalt and ash. Up to cobble size brick, concrete and flint. Dark greyish brown fine medium sand with little fine medium coarse brick and flint. Occasional ceramics, glass and whole red brick.



LegendDepth

(m)

0.200.35

7.50

8.00

Sample

Type No.

FieldTests

Laboratory Tests


U S01

U S02

U S03

D S04

D S05

U S06

D S07

U S08


Window SamplerLog

Sheet 1 of 1




Depth 3.00 Height

Co-ords 580963.00 - 309324.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description





LegendDepth

(m)

0.35

2.10

3.00

Sample

Type No.

FieldTests

Laboratory Tests


U S01

D S02

U S03


Window SamplerLog

Sheet 1 of 1




Depth 3.00 Height

Co-ords 581027.00 - 309309.00

Logged by

Drawn by

Checked by

AT

AT

IB

Backfill

Wate

r

Casin

g

Description





LegendDepth

(m)

0.40

1.20

2.30

Sample

Type No.

FieldTests

Laboratory Tests


U S01

U S02

U S03

Appendix D

7

Other*

WS6

WS8

WS7

WS13

WS9

WS10

WS9

WS12

Container types: T = tub, J = jar, B = litre bottle, V = vial, BB = bulk bag

Comments: sw 26 8 15

Ma

trix

(S

/W e

tc.)

Da

te S

am

ple

d

* Lab to be notified prior to submission

477054

L40420T

01603 222457

�

Lo

ca

tio

n (

BH

/TP

etc

.)

D

�D

Analysis Required (for water samples avoid free oil and sediment where possible)

8267

Fax No

01603 224176E

nviro

lab

Re

f N

o

8261

L4

04

20

T2

05

2 S

pe

cia

ted

To

tal

Pe

tro

leu

m H

yd

roca

rbo

ns (

TP

H)

to

TP

H W

ork

ing

Gro

up

Crite

ria

(U

K)

inclu

din

g a

liph

atic a

nd

aro

ma

tic

Co

nta

ine

rs s

up

plie

d (

se

e b

elo

w)

�

L4

04

20

T2

40

2 S

uite

SB

- S

tan

da

rd

Scre

en

ing

Sa

line

or

bra

ckis

h w

ate

r (Y

/N)

S

Sample information

D

[email protected]

D Joyce

8263

8265

21-Aug

Sampled BySharon WoodsContact

Clie

nt S

am

ple

Re

f N

o (

1,2

etc

)

D0.10 8260 21-Aug

82620.10 21-Aug

De

pth

(m

)

Sa

mp

le T

yp

e (

ES

, D

, U

etc

)

8264

8266 D S

D

ENVIROLAB Analysis Schedule - LAB COPY Need assistance? 0161 368 4921

Client

DaysAddress

Tel No Email [email protected]

Norfolk Partnership Laboratory

County Hall, Martineau Lane, Norwich, Norfolk NR1 2SG

Client/Site

Project No. Requested Turnaround Time

YesAGS Report Required? (Y/N)Swaffham, Stanfield House

JBCO0003

�

�

�

S

0.60

21-Aug

21-Aug

0.60

�

21-Aug

21-Aug

21-Aug

S

S

S

S

Submitted By:

Received By:

Date / Time

Date / Time

TOTAL

S

D

0.30

0.20

D

0.20

0.30

�

�

Fast turnaround ref.

Envirolab project numberEnvirolab quote no.

Purchase Order No

Page 1 of 5

Units 7 & 8 Sandpits Business Park Mottram Road, Hyde, Cheshire, SK14 3AR

FINAL ANALYTICAL TEST REPORT

Envirolab Job Number: 15/05614 Issue Number: 1 Date: 07 September, 2015 Client: Norfolk Partnership Laboratory Environment, Transport and Development Department Norfolk County Council County Hall Norwich Norfolk NR1 2SG Project Manager: Sharon Woods; Simon Holden Project Name: Swafham, Stanfield House Project Ref: JCBO0003 Order No: 477054 Date Samples Received: 27/08/15 Date Instructions Received: 27/08/15 Date Analysis Completed: 07/09/15 Prepared by: Approved by:

Danielle Brierley John Gustafson Administrative Assistant Director

Page 2 of 5

Envirolab Job Number: 15/05614 Client Project Name: Swafham, Stanfield House

Client Project Ref: JCBO0003

Lab Sample ID 15/05614/1 15/05614/2 15/05614/3 15/05614/4 15/05614/5 15/05614/6 15/05614/7 15/05614/8

Un

its

Me

tho

d r

ef

Client Sample No 8260 8262 8261 8267 8263 8265 8264 8266

Client Sample ID WS06 WS08 WS07 WS13 WS09 WS10 WS09 WS12

Depth to Top 0.10 0.10 0.20 0.20 0.30 0.30 0.60 0.60

Depth To Bottom

Date Sampled 21-Aug-15 21-Aug-15 21-Aug-15 21-Aug-15 21-Aug-15 21-Aug-15 21-Aug-15 21-Aug-15

Sample Type Soil - D Soil - D Soil - D Soil - D Soil - D Soil - D Soil - D Soil - D

Sample Matrix Code 6AE 1A 4AE 4AE 5AE 5A 4AE 6A

% Stones >10mmA# 8.2 17.2 18.4 4.1 1.2 <0.1 10.8 27.4 % w/w A-T-044

pHDM#

8.07 8.35 8.34 8.25 8.08 8.24 8.38 9.35 pH A-T-031s

Sulphate (water sol 2:1)DM#

<0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.04 0.07 g/l A-T-026s

Sulphate (acid soluble)DM#

310 <200 <200 310 240 <200 430 1000 mg/kg A-T-028s

Cyanide (total)AM#

<0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 mg/kg Subcon

Phenols - Total by HPLCA <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 mg/kg A-T-050s

SulphideAM#

1.20 0.91 1.90 1.00 1.30 1.00 4.10 390 mg/kg Subcon

Sulphur (elemental)DM#

<5 <5 <5 <5 <5 <5 14 41 mg/kg A-T-029s

Organic matterDM#

2.1 0.2 1.6 2.4 1.3 0.7 2.6 4.2 % w/w A-T-032 OM

ArsenicDM#

7 7 6 7 7 7 7 11 mg/kg A-T-024s

Boron (water soluble)DM#

<1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 mg/kg A-T-027s

CadmiumDM#

<0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 mg/kg A-T-024s

CopperDM#

11 3 7 12 3 10 22 15 mg/kg A-T-024s

ChromiumDM#

10 11 8 12 15 17 10 10 mg/kg A-T-024s

Chromium (hexavalent)D <1 <1 <1 <1 <1 <1 <1 <1 mg/kg A-T-040s

LeadDM#

45 7 32 49 17 19 44 46 mg/kg A-T-024s

MercuryD <0.17 <0.17 <0.17 <0.17 <0.17 <0.17 <0.17 <0.17 mg/kg A-T-024s

NickelDM#

9 10 7 11 12 15 13 14 mg/kg A-T-024s

SeleniumDM#

<1 <1 <1 <1 <1 <1 <1 <1 mg/kg A-T-024s

ZincDM#

36 21 27 40 26 40 68 46 mg/kg A-T-024s

Page 3 of 5



Lab Sample ID 15/05614/1 15/05614/2 15/05614/3 15/05614/4 15/05614/5 15/05614/6 15/05614/7 15/05614/8

Un

its

Me

tho

d r

ef

Client Sample No 8260 8262 8261 8267 8263 8265 8264 8266


Depth to Top 0.10 0.10 0.20 0.20 0.30 0.30 0.60 0.60

Depth To Bottom




PAH 16

AcenaphtheneAM#

<0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.13 mg/kg A-T-019s

AcenaphthyleneAM#

<0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.03 mg/kg A-T-019s

AnthraceneAM#

<0.02 <0.02 <0.02 <0.02 <0.02 <0.02 0.03 0.68 mg/kg A-T-019s

Benzo(a)anthraceneAM#

0.08 <0.04 0.10 0.08 0.07 <0.04 0.20 4.34 mg/kg A-T-019s

Benzo(a)pyreneAM#

0.09 <0.04 0.10 0.08 0.05 <0.04 0.19 4.14 mg/kg A-T-019s

Benzo(b)fluorantheneAM#

0.12 <0.05 0.13 0.12 0.09 <0.05 0.27 5.15 mg/kg A-T-019s

Benzo(ghi)peryleneAM#

0.06 <0.05 0.06 0.05 <0.05 <0.05 0.11 2.32 mg/kg A-T-019s

Benzo(k)fluorantheneAM#

<0.07 <0.07 <0.07 <0.07 <0.07 <0.07 0.09 1.84 mg/kg A-T-019s

ChryseneAM#

0.10 <0.06 0.11 0.12 0.09 <0.06 0.23 4.68 mg/kg A-T-019s

Dibenzo(ah)anthraceneAM#

<0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 0.75 mg/kg A-T-019s

FluorantheneAM#

0.13 <0.08 0.17 0.13 0.15 <0.08 0.34 7.53 mg/kg A-T-019s

FluoreneAM#

<0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.14 mg/kg A-T-019s

Indeno(123-cd)pyreneAM#

0.07 <0.03 0.07 0.06 0.04 <0.03 0.13 2.80 mg/kg A-T-019s

NaphthaleneAM#

<0.03 <0.03 <0.03 <0.03 <0.03 <0.03 <0.03 <0.03 mg/kg A-T-019s

PhenanthreneAM#

0.04 <0.03 0.09 0.04 0.08 <0.03 0.13 2.88 mg/kg A-T-019s

PyreneAM#

0.11 <0.07 0.15 0.12 0.12 <0.07 0.27 5.87 mg/kg A-T-019s

PAH (total 16)AM#

0.82 <0.08 1.00 0.82 0.68 <0.08 1.98 43.3 mg/kg A-T-019s

Page 4 of 5



Lab Sample ID 15/05614/1 15/05614/2 15/05614/3 15/05614/4 15/05614/5 15/05614/6 15/05614/7 15/05614/8

Un

its

Me

tho

d r

ef

Client Sample No 8260 8262 8261 8267 8263 8265 8264 8266


Depth to Top 0.10 0.10 0.20 0.20 0.30 0.30 0.60 0.60

Depth To Bottom




TPH UKCWG

Ali >C5-C6A# - - - - - - - <0.01 mg/kg A-T-022s

Ali >C6-C8A# - - - - - - - <0.01 mg/kg A-T-022s

Ali >C8-C10A# - - - - - - - <0.01 mg/kg A-T-022s

Ali >C10-C12A# - - - - - - - <0.1 mg/kg A-T-023s

Ali >C12-C16A# - - - - - - - <0.1 mg/kg A-T-023s

Ali >C16-C21A# - - - - - - - <0.1 mg/kg A-T-023s

Ali >C21-C35A# - - - - - - - <0.1 mg/kg A-T-023s

Ali >C35-C44A - - - - - - - <0.1 mg/kg A-T-023s

Total AliphaticsA - - - - - - - <0.1 mg/kg A-T-022+23s

Aro >C5-C7A# - - - - - - - <0.01 mg/kg A-T-022s

Aro >C7-C8A# - - - - - - - <0.01 mg/kg A-T-022s

Aro >C8-C9A# - - - - - - - <0.01 mg/kg A-T-022s

Aro >C9-C10A# - - - - - - - <0.01 mg/kg A-T-022s

Aro >C10-C12A# - - - - - - - <0.1 mg/kg A-T-023s

Aro >C12-C16A# - - - - - - - <0.1 mg/kg A-T-023s

Aro >C16-C21A# - - - - - - - 6.3 mg/kg A-T-023s

Aro >C21-C35A# - - - - - - - 21.9 mg/kg A-T-023s

Aro >C35-C44A - - - - - - - <0.1 mg/kg A-T-023s

Total AromaticsA - - - - - - - 28.2 mg/kg A-T-022+23s

TPH (Ali & Aro)A - - - - - - - 28.2 mg/kg A-T-022+23s

BTEX - BenzeneA# - - - - - - - <0.01 mg/kg A-T-022s

BTEX - TolueneA# - - - - - - - <0.01 mg/kg A-T-022s

BTEX - Ethyl BenzeneA# - - - - - - - <0.01 mg/kg A-T-022s

BTEX - m & p XyleneA# - - - - - - - <0.01 mg/kg A-T-022s

BTEX - o XyleneA# - - - - - - - <0.01 mg/kg A-T-022s

MTBEA# - - - - - - - <0.01 mg/kg A-T-022s

Page 5 of 5

REPORT NOTES

Notes - Soil chemical analysis All results are reported as dry weight (<40°C). For samples with Matrix Codes 1 - 6 natural stones and brick and concrete fragments >10mm are removed or excluded from the sample prior to analysis and reported results corrected to a whole sample basis. For samples with Matrix Code 7 the whole sample is dried and crushed prior to analysis. Notes - General

This report shall not be reproduced, except in full, without written approval from Envirolab. Subscript "A" indicates analysis performed on the sample as received. "D" indicates analysis performed on the dried sample, crushed to pass a 2mm sieve, unless asbestos is found to be present in which case all analysis is performed on the sample as received. All analysis is performed on the dried and crushed sample for samples with Matrix Code 7 and this supercedes any "A" subscripts. All analysis is performed on the sample as received for soil samples from outside the European Union and this supercedes any "D" subscripts. Superscript "M" indicates method accredited to MCERTS. If results are in italic font they are associated with an AQC failure. These are not accredited and are unreliable. A deviating samples report is appended and will indicate if samples or tests have been found to be deviating. Any test results affected may not be an accurate record of the concentration at the time of sampling and, as a result, may be invalid. TPH analysis of water by method A-T-007 Free and visible oils are excluded from the sample used for analysis so that the reported result represents the dissolved phase only. Asbestos in soil Asbestos in soil analysis is performed on a dried aliquot of the submitted sample and cannot guarantee to identify asbestos if present as discrete fibres/fragments. Stones etc. are not removed from the sample prior to analysis. Quantification of asbestos is a 3 stage process including visual identification, hand picking and weighing and fibre counting by sedimentation/phase contrast optical microscopy if required. If asbestos is identified a being present but is not in a form that is suitable for analysis by hand picking and weighing (normally if the asbestos is present as free fibres) quantification by sedimentation is performed. Where ACMs are found a percentage asbestos is assigned to each with reference to 'HSG264, Asbestos: The survey guide' and the calculated asbestos content is expressed as a percentage of the dried soil sample aliquot used. Predominant Matrix Codes: 1 = SAND, 2 = LOAM, 3 = CLAY, 4 = LOAM/SAND, 5 = SAND/CLAY, 6 = CLAY/LOAM, 7 = OTHER, 8 = Asbestos bulk ID sample. Samples with Matrix Code 7 are not predominantly a SAND/LOAM/CLAY mix and are not covered by our BSEN 17025 or MCERTS accreditations. Secondary Matrix Codes: A = contains stones, B = contains construction rubble, C = contains visible hydrocarbons, D = contains glass/metal, E = contains roots/twigs. IS indicates Insufficient sample for analysis. NDP indicates No Determination Possible. NAD indicates No Asbestos Detected. N/A indicates Not Applicable. Superscript # indicates method accredited to ISO 17025. Analytical results reflect the quality of the sample at the time of analysis only. Opinions and interpretations expressed are outside the scope of our accreditation. Please contact us if you need any further information.

Appendix E

2

1

122

ICON CONSULTING HETHEL ENGINEERING CENTRE

CHAPMAN WAYHETHEL NORWICH

NR14 8FB01953 857669

L A N D O F F L Y N N R O A D S W A F F H A M N O R F O L KP R O P O S E D R E S I D E N T I A L D E V E L O P M E N TProject : 2213 Drawing 01/01 Date : October 2013 Drawing : Site Location - Site Layout Scale : 1:500

ARCHITECTURALN

SITE LAYOUT Access Road : block open-textured free-draining bitmac with surface dressingDrives : open-jointed block paving or natural aggregatePaths : buff flagsScreening : 1.8m screen walls / 1.8m timber fences and as plot division2.4m x 120m splays to secondary access

REVISED : March 2014 : HighwayOfficer amendments included. Footpathadded : Plots 8 and 9 turning andparking increased.

PLOT 1

PLOT 2

PLOT 3

PLOT 4

PLOT 5

PLOT 6

PLOT 7

PLOT 8af

PLOT 9af

Appendix F

Memorandum

From: Leigh Chant Food, Health & Safety Officer and Environmental Protection Officer My ref: 141103 Your ref: 3PL/2014/0125/F Date: 4 March 2014 ________________________________________________________________________ Subject: - Proposed Residential Development Premises: Stanfield House, 18 Lynn Road, Swaffham I refer to the above planning application. The Contaminated Land Officer has reviewed the historical contaminated land reports (i.e. Desk Study dated November 2008, Ref LAB000336 and supplementary gas investigation correspondence dated 23 October 2009 & 25 February 2010) and comments as follows:

The desk study was originally undertaken over five years previously and a new Desk Study shall need to be submitted in connection with this latest application for planning permission on this site. That said, subject to permission from the author of the original report (Norfolk County Council/Norfolk Partnership Laboratory), it may be possible to update the content of the original report. A new site Walkover Survey will be required to reaffirm the earlier observations and to update the findings, conclusions and recommendations of the original report i.e. where any changes are noted and have arisen in the intervening period of time.

Whilst the existing test results from 2009/10 for landfill and ground gases are supportive

toward the development not requiring gas protection measures, only one of the initial five test locations was located within the area covered by the on-site historical landfill site. This WS1 test location produced the highest percentage concentration of carbon dioxide, with the trial log confirming made ground to a depth approaching 3m. More spatial coverage and sampling & analysis within this area is required, in order to afford greater confidence in the results obtained from a single sample location to date.

Initial investigations took place during the Autumn/Winter period and any gassing regime

may have changed during the intervening period of time. Therefore, it is recommended that further investigations are conducted during the forthcoming Spring/Summer period in 2014 for a more comprehensive ground gas sampling strategy.

The further proposals within Section 7.0 of the Desk Study report are supported,

including investigations at the location of the heating oil tank. A general contamination suite is advocated for the retrieved material from the further

window sample holes, as this will determine whether there is any potential for contamination to be present at shallow depths, such as within the ash material already noted at WS1 within the location of the historical landfill site.

Therefore I recommend applying the following conditions and informative: Conditions

3944 Desk Study/Site Investigation 3946 Unexpected Contamination Informative 3923 Informative (Extensions) NOTE TO PLANNER: Please can you pass the above comments onto the developer (c/o Agent: Icon (UK) Consultancy, Hethel) and their original environmental consultant? The environmental consultant’s details are Norfolk County Council, Norfolk Partnership Laboratory, County Hall, Martineau Lane, Norwich NR1 2SG.

Regards

Leigh Chant Food, Health & Safety Officer and Environmental Protection Officer

Documents

Site Investigation Including Quantitative Risk Assessment