Defence College of Technical Training. Former RAF Lyneham Geo-Environmental Report Appendix D: Preliminary Qualitative Risk Assessment

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1 Item No. Area/ Building Pathway to 1 Identified areas of / (redevelopment Ingestion Inhalation Severe Likely High SKM Enviros desk study highlights several known areas of significant historical. Areas are understood to have mostly been remediated but potential for residual risks and possibly undiscovered similar leaks and spills could exist. Risk to redevelopment workers will be mitigated and controlled by appropriate contaminated land construction / development practice, PPE and good hygiene procedures. 2 Identified areas of / (current site users & Severe Unlikely Moderate / Low As there are currently very few site users and visitors, likelihood set at unlikely. 3 Identified areas of / users: commercial) Direct Contact Ingestion Inhalation of dusts & vapours Severe Low Moderate SKM Enviros desk study highlights several known areas of significant historical. Areas are understood to have mostly been remediated but potential for residual risks and possibly undiscovered similar leaks and spills could exist. pathways being present in commercial training areas is deemed to be unlikely due to presence of hardstanding and buildings which will limit pathways of direct contact and ingestion. There remains a risk of indoor /outdoor vapour inhalation, but the likelihood of this is also considered to be unlikely 4 Identified areas of / users: residential) Severe Low Moderate SKM Enviros desk study highlights several known areas of significant historical. Areas are understood to have mostly been remediated but potential for residual risks and possibly undiscovered similar leaks and spills could existlikelihood of exposure pathways being active in residential areas of the proposed development also considered to be low. Residents will not be growing and eating site grown produce. for indoor /outdoor vapour inhalation, but as residential areas also tend to be away from the known and potential lower likelihood hydrocarbon source areas the likelihood is deemed to be low. 5 Identified areas of / (neighbouring site Severe Unlikely Moderate / Low As above. Likelihood reduced to unlikely for off site users due to distance to off site users, low density of off site users to the south east of the site (i.e the direction that any mobile likely to migrate via the ground,, and surface water/ run off)and assumption that attenuation of will occur along pathway as it migrates off site. 6 Identified areas of / Leaching vertical (Secondary Aquifer) migration through Water Medium Likely Moderate SKM Enviros desk study highlights several known areas of significant historical. Areas are understood to have mostly been remediated but potential for residual risks and possibly undiscovered similar leaks and spills could exist. Ground conditions expected to be permeable. Soil leaching intermediate to high. Shallow water table noted from available SI data. 7 Identified areas of / Runoff migration via site drainage systems Water Medium Low Moderate / Low SKM Enviros desk study highlights several known areas of significant historical. Areas are understood to have mostly been remediated but potential for residual risks and possibly undiscovered similar leaks and spills could exist. Current likelihood assessed as low as most bulk storage and transmission of fuels on and around base has ceased and stocks wound down. Most previous cases of off site surface water have been as a result of significant spillages and leaks. The risk occurring now and in the future of such large scale losses is considered to be low. Risk of residual from these areas migrating to off site surface waters is considered to be low. Page 1 of 12 02/05/2013

2 Item No. Area/ Building Pathway to 8 Identified areas of / Buried Services (current or future) Direct Contact Migration Degradation Vapour Accumulation Explosion migration via permeable ground Severe Low Moderate SKM Enviros desk study highlights several known areas of significant historical. Areas are understood to have mostly been remediated but potential for residual risks and possibly undiscovered similar leaks and spills could exist. There is a low potential for significant hydrocarbon concentrations, free product and vapour in these areas which could / degrade / buried services and potentially lead to vapour increase and explosion in buildings. to buried services = low. vapour ingress / explosion = unlikely 9 Identified areas of / s Direct Contact Ingestion Uptake Toxic Phytotoxicity Mild Low Low SKM Enviros desk study highlights several known areas of significant historical. Areas are understood to have mostly been remediated but potential for residual risks and possibly undiscovered similar leaks and spills could exist. Limited on and off site ecological receptors. Non designated sites. for to Avon Grove Wood, but likelihood considered to be low. 10 Lower Contamination Likelihood Fuel (current site users & Severe Unlikely Moderate / Low SKM Enviros highlights several areas of lower likelihood of hydrocarbon. As there are currently very few site users and visitros, likelihood therefore set at unlikely. 11 Lower Contamination Likelihood Fuel (redevelopment Severe Low Moderate As above, however likelihood set as worst case to 'low' to reflect greater chance of construction and maintenance workers coming into contact with contaminated soils and. Risks would be controlled by standard contaminated land good working practises, hygiene and PPE. 12 Lower Contamination Likelihood Fuel users: commercial) Severe Low Moderate SKM Enviros highlights several areas of lower likelihood of hydrocarbon. pathways being present in commercial training areas is deemed to be low due to presence of hardstanding and buildings which will limit pathways of direct contact and ingestion. There remains a risk of indoor /outdoor vapour inhalation, but the likelihood of this is also considered to be low. 13 Lower Contamination Likelihood Fuel users: residential) Severe Low Moderate As above. exposure pathways being active in residential areas of the proposed development also considered to be low. Residents will not be growing and eating site grown produce. for indoor /outdoor vapour inhalation, but as residential areas also tend to be away from the known and potential lower likelihood hydrocarbon source areas the likelihood is deemed to be low. 14 Lower Contamination Likelihood Fuel (neighbouring site Severe Unlikely Moderate / Low SKM Enviros highlights several areas of lower likelihood of hydrocarbon. Likelihood reduced to unlikely for off site users due to distance to off site users, low density of off site users and assumption that attenuation of will occur along pathway as it migrates off site. Page 2 of 12 02/05/2013

3 Item No. Area/ Building Pathway to 15 Lower Contamination Likelihood Fuel Leaching vertical (Secondary Aquifer) migration through Water Medium Likely Moderate SKM Enviros desk study highlights several areas of lower likelihood hydrocarbon. Ground conditions expected to be permeable. Soil leaching intermediate to high. Shallow water table noted from available SI data. pollutant linkage therefore deemed to be low. 16 Lower Contamination Likelihood Fuel Runoff migration via site drainage systems Water Medium Low Moderate / Low Current likelihood assessed as low as most bulk storage and transmission of fuels on and around the base has ceased and stocks wound down. Most previous cases of off site surface water have been as result of significant spillages and leaks and the risks now and in future of such large scale losses is considered to be low. Risk of residual from these areas migrating to off site surface waters considered to be low. 17 Lower Contamination Likelihood Fuel Buried Services (current or future) Direct Contact Migration Degradation Vapour Accumulation Explosion migration via permeable ground Severe Low Moderate Low potential for significant hydrocarbon concentrations, free product and vapour in these areas (compared to higher risk areas above) which could / degrade / buried services and potentially lead to vapour increase and explosion in buildings. However, significant concentrations of hydrocarbons could still exist in locality but as a result of smaller scale leaks and spills. to buried services deemed to be low. The potential for ingress of vapours into buildings followed by ignition and explosion exists but the likelihood is deemed to be unlikely. Overall likelihood of an active pollutant linkage deemed to be low as worst case. 18 Lower Contamination Likelihood Fuel s Toxic Phytotoxicity Mild Low Low Limited on and off site ecological receptors. Non designated sites. for to Avon Grove Wood, but likelihood considered to be low. 19 Distribution Sub Stations 36 locations (current site users & Severe Unlikely Moderate / Low 36 current and former sub stations. for from insulating and dielectric oils possibly containing. The likelihood for recent historical i.e. (in the last 13 years) by PCB containing oils is very low as these have generally been phased out and replaced since However the potential for historical pre 2000 remains, but is considered to be a unlikely likelihood, although as are very persistent in the environment, if an historical leak or spill did occur, the is likely to still be present. Number of current site users very limited. 20 Distribution Sub Stations 36 locations (redevelopment Severe Low Moderate 36 locations but likelihood of existing in and around these features considered to be low. Construction workers are at greater risk of exposure due to close contact and proximity to soils and. Risks could be controlled by standard contaminated land good working & hygiene practices and PPE. 21 Distribution Sub Stations 36 locations users: residential) Severe Unlikely Moderate / Low 36 locations but likelihood of existing in and around these features considered to be low. Residential end users not expected to grow /consume own produce. Also residents will only occupy the site for relative short periods (expected to be few days or weeks, and up to 1 year maximum) so exposure duration much less than standard residential end use. Pathways of direct contact and ingestion considered to be unlikey in the developed site. As the oils normally used in electrical switchgear, sub stations and transformers tend to be non volatile, the risk from indoor /outdoor inhalation from these sources is unlikely. Page 3 of 12 02/05/2013

4 Item No. Area/ Building Pathway to 22 Distribution Sub Stations 36 locations users: commercial) Severe Low Moderate 36 locations but likelihood of existing in and around these features considered to be low. pathways being present in commercial training areas low due to presence of hardstanding and buildings. for direct contact and ingestion in the outdoor training areas with the sort of military training activities that will be undertaken, but likelihood of an active pathway considered to be low. As the oils normally used in electrical switchgear, sub stations and transformers tends to be non volatile, the risk from indoor /outdoor inhalation from these sources is unlikely. Overall likelihood of an active pollutant linkage deemed to be low. 23 Distribution Sub Stations 36 locations (neighbouring site Severe Unlikely Moderate / Low 36 locations but likelihood of existing in and around these features considered to be low. Likelihood reduced to unlikely for off site users due to distance to off site users, low density of off site users to the south east of the site (i.e direction of general flow, surface water run off, topography) and assumption that attenuation of will occur along pathway as it migrates off site. As the oils normally used in electrical switchgear, sub stations and transformers tends to be non volatile, the risk from indoor /outdoor inhalation from these sources is unlikely 24 Distribution Sub Stations 36 locations Leaching vertical (Secondary Aquifer) migration through Water Medium Likely Moderate 36 locations but likelihood of existing in and around these features considered to be low. a potential active pathway to set at likely (mainly for potential hydrocarbon contaminants) as ground conditions expected to be permeable, a soil leaching intermediate to high and shallow water table noted from available SI data. Likelihood of active pathway for unlikely due to their very low mobility. Overall likelihood of an active pollutant linkage deemed to be low. 25 Distribution Sub Stations 36 locations Runoff migration via site drainage systems Water Medium Unlikely Low Risk to off site surface waters considered to be low. Any around such features expected to be localised. Given distance to off site watercourses, natural attenuation would reduce concentrations and risk of. very unlikely to migrate any distance. 26 Distribution Sub Stations 36 locations Buried Services (current or future) Direct Contact migration via permeable ground Degradation Vapour Accumulation Explosion Medium Unlikely Low Risk of to buried services from that might be present at these features is deemed to be low as any is expected to be small scale and localised (as volumes of oils within the equipment potentially available to leak / spill is low). Risk of vapours / explosion also unlikely as oils used in electrical equipment of low to very low volatility. As a result of unlikely explosion risk, the consequence of building is reduced to mild. 27 Distribution Sub Stations 36 locations s Direct Contact Ingestion Uptake Toxic Phytotoxicity Mild Unlikely Negligible Limited on and off site ecological receptors. Non designated sites. for to Avon Grove Wood, but likelihood considered to be unlikely. Oils used in electrical equipment tend to be heavier oils of low to very low environmental mobility, therefore from such features unlikely to migrate to ecological features on/ off site. 28 Burning Grounds in the Spitfire Dispersal (current site users & Severe Unlikely Moderate / Low SKM Enviros investigations / report concludes that there are high levels of in shallow soil in APC4 and AP6 (both former burning areas within the Spitfire dispersal area) which are considered by SKM to pose a risk to future users that may come into contact with them. No current training activities in these areas as the base now closed. Also, very low numbers of current site users and visitors on the site. an active pollutant linkage deemed to be unlikely overall. Page 4 of 12 02/05/2013

5 Item No. Area/ Building Pathway to 29 Burning Grounds in the Spitfire Dispersal (redevelopment Severe Unlikely Moderate / Low According to the current development / masterplan, no groundwork intended in the former burning areas in the Spitfire Dispersal ground, therefore likelihood of a pollutant linkage considered to be unlikely. 30 Burning Grounds in the Spitfire Dispersal users: residential) Severe Unlikely Moderate / Low As above, however no current or proposed (i.e. future) residential use in the western areas of the site i.e. within Burning Grounds in the Spitfire Dispersal. Therefore likelihood of pollutant linkage is deemed as unlikely. 31 Burning Grounds in the Spitfire Dispersal users: commercial) Severe Low Moderate Former Burning Grounds in the Spitfire Dispersal Area (Western ) form part of the overall Planning Application Red line Boundary, but the areas are not shown on the Masterplan as being earmarked for external training,. It is understood that these areas could potentially be used for informal training activities. pollutant linkage deemed to be low. If these areas will not be used for training and likelihood of other informal access is restricted, then likelihood would be unlikely. Due to uncertainty over whether these areas will be used for any outdoor training and if so the nature of that training, the likelihood has been deemed to be low. 32 Burning Grounds in the Spitfire Dispersal (neighbouring site Severe Unlikely Moderate / Low Likelihood reduced to unlikely for off site users due to distance to off site users, low density of off site users to west south and south east i.e direction of likely migration (if was to migrate) and assumption that attenuation of will occur along pathway as it migrates off site. 33 Burning Grounds in the Spitfire Dispersal (Secondary Aquifer) Leaching vertical migration through Water Medium Likely Moderate SKM Enviros investigations / report concludes that there are high levels of in shallow soil in APC4 and AP6 (both former burning areas within the Spitfire dispersal area) which are considered by SKM to pose a risk to. Ground conditions generally permeable, intermediate to high soil leaching and shallow. Therefore likelihood of an active pollutant linkage deemed to be likely. 34 Burning Grounds in the Spitfire Dispersal Runoff migration via site drainage systems Water Medium Low Moderate / Low SKM Enviros investigations / report concludes that there are high levels of in shallow soil in APC4 and AP6 (both former burning areas within the Spitfire dispersal area). a linkage to off site surface waters deemed to be low. Direction of surface water run off and shallow ground water flow will depend on local topography. Based on the local topography, surface water run off and any shallow flow and any mobile from AP6 in these areas will probably flow north / north east down scarp slope and possibly enter surface waters (unnamed tributary of the River Avon) which emerge at base of scarp slope just to the north of Britlesea Farm ( m to the north of the site). Given the distance to these off site surface waters the likelihood of a linkage is considered to be low. Based on the local topography, surface water run off and any shallow flow and any mobile from AP4 in these areas will probably flow south /south west down scarp slope and possibly enter surface water tributaries of the Cada Burma which arise / issue at the base of the scarp slope near to Godsell Farm. However, given the distance (~500m) to these off site surface waters the likelihood of a linkage is considered to be low Page 5 of 12 02/05/2013

6 Item No. Area/ Building Pathway to 35 Burning Grounds in the Spitfire Dispersal Buried Services (current or future) Direct Contact migration via permeable ground Degradation Minor Unlikely Negligible There are no current or proposed built structures in the area. 36 Burning Grounds in the Spitfire Dispersal s Toxic Phytotoxicity Mild Low Low Avon Grove Wood (a County Wildlife Site) is present adjacent to the south / south west of the Burning Grounds in the Spitfire Dispersal. a linkage is deemed to be low. Direction of surface water run off and shallow ground water flow will depend on local topography. Based on the local topography, surface water run off and any shallow flow and any mobile from APC 6 will probably flow north / north east i.e. away from Avon Grove Wood, so likelihood of a linkage from this source is low to unlikely. Based on the local topography, surface water run off and any shallow flow and any mobile from APC 4 will probably flow south /south west i.e. towards Avon Grove Wood, so likelihood of a linkage is deemed to be low. Overall likelihood deemed to be low. 37 Waste Burial Areas at Spitfire Dispersal (current site users &,, phenols, Severe Unlikely Moderate / Low SKM Enviros investigations / report concludes that soils in the tip area pose a risk to site users that disturb the ground due to widespread including asbestos free fibres. No current training activities in these areas as the base now closed. Also, very low numbers of current site users and visitors on the site. Likelihood therefore deemed to be unlikely. 38 Waste Burial Areas at Spitfire Dispersal (redevelopment,, phenols, Severe Unlikely Moderate / Low As above, however, from the current development / masterplan no groundwork's are intended in the former waste disposal area, therefore likelihood of a pollutant linkage considered to be unlikely. 39 Waste Burial Areas at Spitfire Dispersal users: residential),, phenols, Severe Unlikely Moderate / Low As above, however no current or proposed (i.e. future) residential use in the western areas of the site. Therefore likelihood of pollutant linkage is deemed as unlikely. 40 Waste Burial Areas at Spitfire Dispersal,, phenols, users: commercial) Severe Low Moderate Western form part of overall Planning Application Red line Boundary, but the areas are not shown on the Masterplan as being earmarked for external training, however it is understood that these areas could potentially be used for informal training activities. pollutant linkage deemed to be low but depends on nature of any informal training activities that may be undertaken. If these areas will not be used for training and likelihood of other informal access is restricted, then likelihood would be unlikely'. Due to uncertainty over whether these areas will be used for any outdoor training and if so the nature of that training, the likelihood has been deemed to be low. 41 Waste Burial Areas at Spitfire Dispersal (neighbouring site,, phenols, Severe Unlikely Moderate / Low Likelihood reduced to unlikely for off site users due to distance to off site users, low density of off site users and assumption that attenuation of will occur along pathway as it migrates off site. Page 6 of 12 02/05/2013

7 Item No. Area/ Building Pathway to 42 Waste Burial Areas at Spitfire Dispersal 43 Waste Burial Areas at Spitfire Dispersal 44 Waste Burial Areas at Spitfire Dispersal 45 Waste Burial Areas at Spitfire Dispersal 46 Soil Mounds containing waste materials Leaching vertical (Secondary Aquifer) migration through,, phenols,,, phenols, Buried Services, (current or future), phenols, s,, phenols, Asbestos, Metals, (current hydrocarbons site users & Runoff Leaching Direct Contact migration via permeable ground Water Medium Likely Moderate SKM Enviros investigation and report identifies that in the area has been identified as being potentially ed with the potential for off site migration. Ground conditions generally permeable, intermediate to high soil leaching and shallow. Therefore likelihood of an active pollutant linkage deemed to be likely. Water Medium Low Moderate / Low Based on the local topography, surface water run off and any shallow flow and any mobile from APC8 (former tip area) in these areas will probably flow west / south / south west down scarp slope and possibly enter surface water tributaries of the Cada Burma which arise / issue at the base of the scarp slope near to Godsell Farm. However, given the distance ( approximately 500m) to these off site surface waters, the likelihood of a linkage is considered to be low. Degradation Vapour / gas accumulation Explosion Mild Unlikely Negligible There are no current or propose built structures in the area. Toxic Phytotoxicity Mild Low Low Based on the local topography, surface water run off and any shallow flow and any mobile from APC8 (waste disposal area) in these areas will probably flow south /south west i.e. towards Avon Grove Wood. Despite potential for contaminants to migrate towards Avon Grove Wood, the likelihood of a linkage is still deemed to be low i.e. the exposure mechanisms of direct contact., ingestion and uptake are considered to be low likelihood. Severe Unlikely Moderate / Low The mounds are understood to be grassed, therefore risk of direct contact and ingestion is unlikely. Risk from these areas mainly from potential asbestos however only a risk if current users disturb /excavate into areas which is considered to be unlikely given the very low numbers of current site users. 47 Soil Mounds containing waste materials Asbestos, Metals, hydrocarbons (redevelopment Severe Low Moderate Risk from these areas mainly from potential asbestos, likelihood increased to low for redevelopment workers due to their increased risk of exposure / contact / ingestion / inhalation with soils/. The existing mounds are within the development area so may be disturbed during the re-development. Risks would be controlled however, by standard contaminated land good construction practice, good hygiene procedures and appropriate PPE. 48 Soil Mounds containing waste materials Asbestos, Metals, hydrocarbons users: residential) Severe Unlikely Moderate / Low None of the current soil mounds are within proposed future residential areas. Therefore likelihood of linkage is deemed to be unlikely. Page 7 of 12 02/05/2013

8 Item No. Area/ Building Pathway to 49 Soil Mounds containing waste materials Asbestos, Metals, hydrocarbons users: commercial) Severe Unlikely Moderate / Low Some of existing bunded area are within area of proposed external and internal training areas and sports pitches and outdoor areas. It is considered unlikely that future commercial users of the site will disturb the mounds if they are left as they are post development. The mounds are also grassed. If they are left as they are post development, then likelihood of direct contact and ingestion deemed to be unlikely. 50 Soil Mounds containing waste materials Asbestos, Metals, hydrocarbons (neighbouring site Severe Unlikely Moderate / Low Risk to off site residents only likely during construction works i.e. if the bunds are disturbed. linkage considered to be unlikely given the distance to off site receptors. Also standard good construction environmental practises to control / prevent run off and dust would be implemented during the works. 51 Soil Mounds containing waste materials Asbestos, Metals, Leaching vertical hydrocarbons (Secondary Aquifer) migration through Water Medium Low Moderate / Low Whilst ground conditions are generally permeable on site and soil leaching potential intermediate to high and shallow, the likelihood of significant, mobile within these features considered to be low. 52 Soil Mounds containing waste materials Asbestos, Metals, hydrocarbons Runoff migration via site drainage systems Water Medium Unlikely Low significant, mobile within these features considered to be low. linkage to off site surface water courses deemed to be unlikely. 53 Soil Mounds containing waste materials Asbestos, Metals, hydrocarbons Buried Services (current or future) Direct Contact migration via permeable ground Degradation Mild Unlikely Negligible significant, mobile within these features considered to be low. linkage to buried structures and buildings deemed to be unlikely. The potential consequence for buildings and buried services s from these sources has been reduced to mild as they are landscape bunds which are unlikely to have any built environment within / on them, and it is considered very unlikely that they will be a significant source of ground gas/vapours. As such the risks of explosion within buildings as a result of gas migration from these sources is deemed to be unlikely. 54 Soil Mounds containing waste materials Asbestos, Metals, hydrocarbons s Toxic Phytotoxicity Mild Unlikely Negligible Only on site ecological receptor (Avon Grove Wood) is located several hundred metres up topographic slope from the soil mounds. linkage deemed to be unlikely. 55 Workshops, garages and maintenance (current site users & Severe Unlikely Moderate / Low Risk from these areas mainly if current or future users disturb /excavate into areas which is considered to be unlikely. Number of site users and visitors very low following site closure in Page 8 of 12 02/05/2013

9 Item No. Area/ Building Pathway to 56 Workshops, garages and maintenance (redevelopment Severe Low Moderate Likelihood increased to low for redevelopment workers due to their increased risk of exposure / contact / ingestion / inhalation with soils and during construction works. Risks would be controlled however, by standard contaminated land good construction practice, hygiene and appropriate PPE. 57 Workshops, garages and maintenance users: residential) Severe Unlikely Moderate / Low Majority of proposed residential area (i.e. eastern area of Main Site) is not within areas of current and historical, workshops and garages. linkage from these sources to this receptor is deemed to be unlikely. 58 Workshops, garages and maintenance users: commercial) Severe Low Moderate Proposed indoor training areas within Main Site area are within areas of current and historical workshops and garages. for dermal contact and ingestion unlikely, but potential for indoor inhalation of possible hydrocarbon and /or solvent vapours is deemed to be low. 59 Workshops, garages and maintenance (neighbouring site Severe Unlikely Moderate / Low significant in vicinity of these features deemed to be low. Concrete floor and hardstanding in and around such features will have generally contained and prevented any leaks and spillages from entering the ground. Some of these features are known to have had (possibly still have) underground fuel storage tanks which have the potential to have leaked. Given distance to most off site receptors, likelihood of a pollutant linkage is deemed to be unlikely. 60 Workshops, garages and maintenance Leaching vertical (Secondary Aquifer) migration through Water Medium Likely Moderate significant in vicinity of these features deemed to be low. Concrete floor and hardstanding in and around such features will have generally contained and prevented and leaks and spillages from entering ground. Some of these features are known to have had (possibly still have) underground fuel storage tanks which have the potential to have leaked. Ground conditions on site are generally permeable, soils have intermediate to high leaching potential and is shallow. Therefore, likelihood of a pollutant linkage to from these sources is deemed to be likely. 61 Workshops, garages and maintenance Runoff migration via site drainage systems Water Medium Low Moderate / Low for significant, large scale (i.e. volume and area) releases from these features is considered to be low. Any mobile in these areas is likely to flow east / south east following topography and ultimately discharge to off site surface waters to the east and south east of the site. However, given pathway distances, attenuation is likely to be significant, therefore, likelihood of a linkage is low. A more direct, rapid pathway would be via site surface water drainage, but attenuation (dilution) within the system would occur. Again likelihood considered to be low. 62 Workshops, garages and maintenance Buried Services (current or future) Direct Contact Migration Degradation Vapour / gas accumulation migration via permeable Explosion ground Severe Low Moderate Likelihood for significant in and around these sources is considered to be low as most historical engineering activities took place indoors on concrete hardstanding. Concrete floor and hardstanding in and around such features will have generally contained and prevented and leaks and spillages from entering ground. Some of these features are known to have had (possibly still have) underground fuel storage tanks which have the potential to have leaked. However, the contaminants that may be present e.g. hydrocarbons, and acids have the potential to degrade and permeate buried services and concrete (acid). for vapour ingress if new buildings are built on top of areas of significant hydrocarbon / solvent. Consequence therefore potentially severe as a worst case (but probably medium) and likelihood unlikely to low. Overall likelihood deemed to be low. Page 9 of 12 02/05/2013

10 Item No. Area/ Building Pathway to 63 Workshops, garages and maintenance s Toxic Phytotoxicity Mild Unlikely Negligible Only on site ecological receptor (Avon Grove Wood) is located several hundred metres up topographic slope from the soil mounds. linkage deemed to be unlikely. 64 Tanks at Quick Engine change Building PAH, (current site users & Severe Unlikely Moderate / Low Risk from this area mainly if current users disturb /excavate areas. Outdoor / indoor vapour inhalation is considered to be unlikely given the number of site users and visitors currently on site is very low following site closure in Tanks at Quick Engine change Building PAH, (redevelopment Severe Low Moderate Risk to redevelopment workers increased to low due to greater potential for exposure to soils and during construction. However, according to the Masterplan, the area concerned (Tanks at Quick Engine change ) are earmarked for refurbishment only, so there is not expected to be any major groundwork's. Soil gas probe in 2004 SKM Enviros survey did detect elevated VOCs (150 ppm) so potential for outdoor and indoor vapour risk during refurbishment, however likelihood considered to be low. Risks would be controlled by safe working practises, good hygiene procedures, PPE and air monitoring if needed. 66 Tanks at Quick Engine change Building PAH, users: residential) Severe Unlikely Moderate / Low No planned residential facilities in proximity to this source area. linkage therefore unlikely. 67 Tanks at Quick Engine change Building PAH, users: commercial) Severe Low Moderate Area proposed for indoor workshop / engineering training facility. direct contact / ingestion pathways unlikely. Main potential risk would be via indoor and outdoor vapour inhalation. Likelihood deemed to be low as concrete floor likely to restrict vapour entry and ventilation in building likely to be large. vapour linkage deemed to be low. 68 Tanks at Quick Engine change Building 0 (neighbouring site Severe Unlikely Moderate / Low Given location of this potential source feature on the southern boundary of D site, topographic information suggest surface run off and shallow will flow south /south west towards Pepper Alley Wood. No nearby off site residential properties. linkage deemed to be unlikely. 69 Tanks at Quick Engine change Building PAH, Leaching vertical (Secondary Aquifer) migration through Water Medium Likely Moderate a linkage to deemed to be likely due to presence of a historical BFI at this location, elevated vapour suggest some nearby has occurred and generally permeable ground on site, intermediate to high leaching potential and shallow. Page 10 of 12 02/05/2013

11 Item No. Area/ Building Pathway to 70 Tanks at Quick Engine change Building 71 Tanks at Quick Engine change Building PAH, PAH, Buried Services (current or future) Runoff migration via site drainage systems Direct Contact Migration Degradation Vapour / Vapour gas accumulation / gas Migration Explosion Water Medium Low Moderate / Low for significant at this location deemed to be likely (on basis of experience of investigations around several other BFIs). SKM Enviros investigated this feature in 2004but only 1 location (DS-WS18/SP18) which apparently didn't identify any but this exploratory hole was not positioned on expected down gradient side of BFI. Soil gas probe VOC measurements suggests there has been some in the locality. Soil gas probe VOC measurements suggests there has been some in the locality. Topographic information suggest surface run off and shallow will flow south /south west towards Pepper Alley Wood. Nearest off site surface waters (tributaries of the Cada Burna) are approximately m to the south. Given distance and potential for natural attenuation along the migration route, the likelihood of a linkage to off site surface waters migration is deemed to be unlikely. The potential for a more direct pathway to off site surface waters via on site surface water drainage exists. such a linkage considered to be low. Severe Low Moderate for significant at this location deemed to be likely (on basis of experience of investigations around several other BFIs). SKM Enviros investigated this feature in 2004 but only 1 location (DS-WS18/SP18) which apparently didn't identify any but this exploratory hole was not positioned on expected down gradient side of BFI. Soil gas probe VOC measurements suggests there has been some in the locality. Topographic information suggests any will migrate towards south / south west, so has the potential to flow under D2 Hanger building 216. Type of contaminants from this feature includes hydrocarbons and which can degrade / permeate through plastic services and also lead to potential vapour ingress and possible explosion within buildings. According to the Masterplan, building 216 is being refurbished with no new build in the area. a linkage deemed to be low. 72 Tanks at Quick Engine change Building PAH, s Toxic Phytotoxicity Mild Unlikely Negligible for significant at this location deemed to be likely (on basis of experience of investigations around several other BFIs). SKM Enviros investigated this feature in 2004 but only 1 location (DS-WS18/SP18) which apparently didn't identify any but this exploratory hole was not positioned on expected down gradient side of BFI. Soil gas probe VOC measurements suggests there has been some in the locality. Topographic information suggest surface run off and shallow will flow south /south west towards Pepper Alley Wood. Given distance and potential for natural attenuation along migration route, likelihood of a linkage to Ecology such as Pepper Alley Wood is deemed to be unlikely. 73 General Made Ground Site Wide Metals, sulphates, (current asbestos, low site users & levels of ground Severe Unlikely Moderate / Low current site users coming into contact with General Made Ground under current site conditions / use is considered to be unlikely. Very few current users on site. 74 General Made Ground Site Wide Metals, sulphates, asbestos, low (redevelopment levels of ground Severe Low Moderate Likelihood increased to low for redevelopment workers due to their increased risk of exposure / contact / ingestion / inhalation with soils during construction works. Risks would, however, be controlled by standard contaminated land good construction practice, hygiene and appropriate PPE. 75 General Made Ground Site Wide Metals, sulphates, asbestos, low users: residential) levels of ground Severe Unlikely Moderate / Low end users in the proposed residential areas of the site coming into contact with contaminated general Made Ground considered to be unlikely. Any areas of Made Ground will be covered by buildings and hardstanding and / or a suitable depth of clean soil cover in soft landscaped areas. A potential risk from indoor / outdoor inhalation of vapours is considered to exist, however, the likelihood of significant volatile hydrocarbon and /or solvent within the general Made Ground (particularly within the proposed residential areas) is considered to be unlikely as the SKM Enviros desk study indicates that the proposed residential areas tend to be located away from the potential historical contaminative activities and features. 76 General Made Ground Site Wide Metals, sulphates, asbestos, low users: commercial) levels of ground Severe Low Moderate end users in the proposed commercial training areas of the site coming into contact with contaminated general Made Ground considered to be low. This rating mainly applies to the external training areas, where due to the sort of training activities that will be undertaken, there is considered to be a high likelihood of direct contact, ingestion and inhalation of soils and Made Ground. Although there is considered to be a high likelihood of exposure to general Made Ground in the external training areas, the levels of in general within the Made Ground are not expected to be significant. There is however the potential for occasional, isolated, localised hotspots of elevated metals such as arsenic, PAHs such as benzo a pyrene, TPH and potentially the presence of asbestos containing materials with general Made Ground, but such hotspots are expected to be infrequent. Therefore, the overall likelihood of an active pathway from this source to commercial end users is deemed to be low. Page 11 of 12 02/05/2013

12 Item No. Area/ Building Pathway to 77 General Made Ground Site Wide Metals, sulphates, asbestos, low (neighbouring site levels of ground Severe Unlikely Moderate / Low Likelihood reduced to unlikely for off site users due to distance to off site users, low density of off site users and assumption that attenuation of will occur along pathway as it migrates off site. General Made Ground not expected to have significant concentrations of mobile. Risk to off site users is increased during any construction works which involve excavation and disturbance of Made Ground, however, standard good construction environmental / contaminated land practices (e.g. dust and run off controls) would be implemented during the works. Therefore, likelihood of an active pathway to off site residents from general Made Ground is considered to be unlikely. 78 General Made Ground Site Wide Metals, sulphates, Leaching vertical asbestos, low (Secondary Aquifer) migration through levels of ground Water Medium Low Moderate / Low to from the general Made Ground has been reduced to low rather than likely which is the rating used for the other more significant potential sources above This is to reflect the expectation that the Made Ground is unlikely to contain significant concentrations of mobile in general. As detailed above, there are likely to be occasional, localised hotspots of more significant and possible mobile within the Made Ground, but these are expected to be infrequent and localised in their occurrence. 79 General Made Ground Site Wide Metals, sulphates, asbestos, low levels of ground Medium Unlikely Low to surface waters from the general Made Ground is deemed to be unlikely. This is to reflect the expectation that the Made Ground is unlikely to contain significant concentrations of mobile in general. As detailed above, there are likely to be occasional, localised hotspots of more significant and possible mobile within the Made Ground, but these are expected to be infrequent and localised where they occur. 80 General Made Ground Site Wide Metals, sulphates, asbestos, low Buried Services levels of ground (current or future) Direct Contact migration via permeable ground Degradation Vapour / gas accumulation Explosion Severe Low Moderate to built environment from the general Made Ground is deemed to be low. This is to reflect the expectation that the Made Ground is unlikely to contain significant concentrations of mobile in general. As detailed above, there are likely to be occasional, localised hotspots of more significant and possible mobile within the Made Ground which could locally buried services and concrete but these are expected to be infrequent. Made Ground can often contain slightly elevated concentrations of ground, however, the concentrations, and more particularly the flow rates and gas pressures are usually very low. As such the risk to buildings from ground gas generated from within the general Made Ground is deemed to be low. 81 General Made Ground Site Wide Metals, sulphates, asbestos, low s levels of ground Toxic Phytotoxicity Mild Unlikely Negligible to on /off site ecology from the general Made Ground is deemed to be unlikely. This is to reflect the expectation that the Made Ground is unlikely to contain significant concentrations of mobile in general. As detailed above, there are likely to be occasional, localised hotspots of more significant and possible mobile within the Made Ground, but these are expected to be infrequent and localised where they occur. Page 12 of 12 02/05/2013