Can UXO still pose a risk to construction projects in Bristol?
The primary potential risk from UXO in Bristol is from items of German air-delivered ordnance which failed to function as designed.
Approximately 10% of munitions deployed during WWII failed to detonate, and whilst efforts were made during, and after the war to locate and make UXBs safe, not all items were discovered.
This is evidenced by the regular, on-going discoveries of UXO during construction-related intrusive ground works across the UK – not just in Bristol.
Occasionally items of British explosive ordnance are also encountered – often associated with WWII defensive measures or Home Guard operations. However, there were few military related facilities in or around the city.
I am about to start a project in Bristol, what should I do?
Developers and ground workers should consider this potential before intrusive works are planned, through either a Preliminary UXO Risk Assessment or Detailed UXO Risk Assessment. This is the first stage in our UXO risk mitigation strategy and should be undertaken as early in a project lifecycle as possible in accordance with CIRIA C681 guidelines
It is important that where a viable risk is identified, it is effectively and appropriately mitigated to reduce the risk to as low as reasonably practicable (ALARP). However, it is equally important that UXO risk mitigation measures are not implemented when they are not needed.
While there is certainly potential to encounter UXO during construction projects in Bristol, it does not mean that UXO will pose a risk to all projects. Just because a site is located in Bristol does not mean there is automatically a ‘high’ risk of encountering UXO. It really does depend on the specific location of the site being developed.
A well-researched UXO Risk Assessment will take into account location specific factors – was the actual site footprint affected by bombing, what damage was sustained, what was the site used for, how much would it have been accessed, what were the ground conditions present etc.
It should also consider what has happened post-war – how much development has occurred, to what depths have excavations taken place and so on. This will allow an assessment of the likelihood that UXO could have fallen on site, gone unnoticed and potentially still remain in situ.