Unexploded Ordnance (UXO)
Preliminary Risk Assessment

The majority of UXO encountered in the UK is not actually of German origin. During WWII, over 4,000,000 hectares of UK land were in use with British and Allied armed forces. The Construction Industry Research and Information Association (CIRIA) estimates that approximately 20% of the UK's land mass has seen some form of military activity at some stage. As of 2017, the MOD’s training estate covered around 364,000 hectares. For these reasons, the only way to be sure of identifying all UXO risks on your site is to carry out a UXO Risk Assessment.

The majority of UXO encountered in the UK is not actually of German origin. During WWII, over 4,000,000 hectares of UK land were in use with British and Allied armed forces. The Construction Industry Research and Information Association (CIRIA) estimates that approximately 20% of the UK's land mass has seen some form of military activity at some stage. As of 2017, the MOD’s training estate covered around 364,000 hectares. For these reasons, the only way to be sure of identifying all UXO risks on your site is to carry out a UXO Risk Assessment.

It cannot be ruled out completely as your site could still have been bombed from opportunistic ‘tip and run’ raids that were common during WWII. Bombing overspill from raids on other major targets nearby may have also affected your site, and we would always recommend to get a UXO Risk Assessment first.

It cannot be ruled out completely as your site could still have been bombed from opportunistic ‘tip and run’ raids that were common during WWII. Bombing overspill from raids on other major targets nearby may have also affected your site, and we would always recommend to get a UXO Risk Assessment first.

Unfortunately not. They are often incomplete and should be used in conjunction with other records wherever possible. For example combining information from WWII-era aerial photography, bomb census mapping and written bomb incident records would give a more accurate indication of where a bomb fell than one of these sources alone. It is imperative that historical research for UXO Risk Assessments is thorough and that all available resources are utilised.

Unfortunately not. They are often incomplete and should be used in conjunction with other records wherever possible. For example combining information from WWII-era aerial photography, bomb census mapping and written bomb incident records would give a more accurate indication of where a bomb fell than one of these sources alone. It is imperative that historical research for UXO Risk Assessments is thorough and that all available resources are utilised.

You may be putting people at risk. Although UXO risk in the UK is generally considered ‘low probability’, it is ‘high consequence’. Health and safety legislation requires you to consider foreseeable risks such as this. Even the unexpected discovery of an item of UXO can incur expensive downtime, delays and cost overruns. Being aware of the potential risk of UXO on your site is essential. You do not have to conduct a comprehensive UXO Survey for every site, but the risk of UXO should be considered and a Preliminary or Detailed UXO Risk Assessment undertaken.

You may be putting people at risk. Although UXO risk in the UK is generally considered ‘low probability’, it is ‘high consequence’. Health and safety legislation requires you to consider foreseeable risks such as this. Even the unexpected discovery of an item of UXO can incur expensive downtime, delays and cost overruns. Being aware of the potential risk of UXO on your site is essential. You do not have to conduct a comprehensive UXO Survey for every site, but the risk of UXO should be considered and a Preliminary or Detailed UXO Risk Assessment undertaken.

The type of information we use can depend on factors such as where the site is located – but for a Detailed Risk Assessment, as a minimum we would use the following where available:

• Previous military use, location history and land use.
• Reports and records of air-delivered bombs (WWI & WWII).
• Frequency of access, damage, ground cover.
• Consideration of any mitigating factors.
• Extent and nature of proposed intrusive works.
• Local and national archives.
• Historical and bomb census and damage mapping.
• High-resolution WWII-era aerial photography.
• Written ARP bomb incident reports.
• Luftwaffe target information.

The type of information we use can depend on factors such as where the site is located – but for a Detailed Risk Assessment, as a minimum we would use the following where available:

• Previous military use, location history and land use.
• Reports and records of air-delivered bombs (WWI & WWII).
• Frequency of access, damage, ground cover.
• Consideration of any mitigating factors.
• Extent and nature of proposed intrusive works.
• Local and national archives.
• Historical and bomb census and damage mapping.
• High-resolution WWII-era aerial photography.
• Written ARP bomb incident reports.
• Luftwaffe target information.

If a Preliminary UXO Risk Assessment has identified a potential UXO risk on your site, we would recommend that a Detailed UXO Risk Assessment is commissioned – which is an in-depth desktop study which fully investigates the risk of UXO being present. If the Detailed UXO Risk Assessment has identified a threat from UXO and it has been classified as medium or high, we would recommend a risk mitigation plan is created and implemented to reduce the risk to as low as reasonably practicable (ALARP).

If a Preliminary UXO Risk Assessment has identified a potential UXO risk on your site, we would recommend that a Detailed UXO Risk Assessment is commissioned – which is an in-depth desktop study which fully investigates the risk of UXO being present. If the Detailed UXO Risk Assessment has identified a threat from UXO and it has been classified as medium or high, we would recommend a risk mitigation plan is created and implemented to reduce the risk to as low as reasonably practicable (ALARP).

No, the Preliminary UXO Risk Assessment is a ‘desktop’ study. We utilise ‘in-house’ information from our extensive digital archives, library, geo-databases, as well as online resources to undertake the preliminary research on your site – so a site visit is generally not necessary.

Hundreds of thousands of bombs were dropped all over the UK during WWI and WWII – with around 10% failing to explode. Therefore, even if UXO risk might not seem likely, it is still best practice to carry out a Preliminary UXO Risk Assessment.

A Preliminary UXO Risk Assessment is an initial screening check to determine whether there was any history of bombing or military activity on your site. The report will confirm whether further investigation is required or no further research is necessary.

Usually, the main pieces of information we require is:

• Full address and postcode.
• A map / plan of the site with the boundary that needs to be investigated clearly highlighted, preferably using a ‘red line’ for the boundary.
• Details about any proposed intrusive ground works – boreholes, trial pits, piling, strip foundations etc.
• Site specific geotechnical information / borehole logs – if available.

To place an order for a Preliminary UXO Risk Assessment contact us on +44 (0) 1992 245020 or info@1stlinedefence.co.uk or use our contact form to register your interest and a member of the team will get in touch.

A Preliminary UXO Risk Assessment will usually be completed within 1 or 2 working days but can be done sooner if required.

A Preliminary UXO Risk Assessment usually costs £150 but costs can vary for larger and more complex sites. If you are looking to place an order for multiple sites at the same time, contact us because 1st Line Defence can offer a special discount for bulk orders. If you receive a more competitive quote, let us know and we will try our best to match or beat it.