Preliminary Risk Assessments – A Guide To Good Practice
Introduction
It is important that any construction works in the UK are underpinned by an understanding of the potential UXO hazard.
Where a potential UXO hazard is identified on a site, a detailed UXO risk assessment is required to evaluate the risk to proposed works and ensure that any future works go ahead safely.
If you are unsure whether a detailed UXO risk assessment is required for a site, then the first stage is to undertake a preliminary risk assessment.
This is a concise report which uses readily available sources of information to identify potential sources of UXO hazard at a site. Its primary objective is to confirm whether more detailed assessment is required.
A preliminary risk assessment can be undertaken by a non-UXO specialist.
What should a Preliminary Risk Assessment consider?
According to industry guidance, ‘CIRIA, Unexploded Ordnance (UXO), a Guide for the Construction Industry, 2009’, the two principal factors that a preliminary risk assessment should consider are:
1. Military Activity
If the site has an obvious former military use (i.e. a military airfield or barracks), then a detailed risk assessment is essential as there may be an elevated potential of encountering UXO.
A historical map indicating military land use (source: NLS)
Some indicators of military activity may not always be obvious. Most military training ranges do not typically appear on historical maps, and details of manoeuvres and exercises can be sparse. This is where obtaining a preliminary risk assessment from a UXO specialist is beneficial, as they may have access to readily available information that may not be evident to a non-specialist.
2. WWI/WWII Bombing
If there is evidence that the site was bombed during World War One (WWI) or World War Two (WWII) then a detailed risk assessment should be undertaken.
Where this evidence is not readily available, indicators of potential Unexploded Bombs (UXBs) should be considered.
If, for example, a site is located in an area that was heavily bombed (e.g. central Liverpool) or was situated near to an important strategic target (e.g. a dockyard), then a detailed desk study is recommended.
Historic aerial photographs are good indictors of bomb damage, and are often readily available online (source: GeoInfromationGroup)
If, however, a site is in an urban area that escaped significant bombing, or in a rural setting where no evidence of bombing is identified, then UXBs are unlikely to provide a source of UXO hazard. In this instance, a detailed risk assessment, whilst always prudent, may not be necessary.
It is anticipated that most sites in the UK have a low probability of encountering UXO. Therefore, for most sites, a preliminary risk assessment may be sufficient to satisfy the UXO risk management process.
A diagram outlining the preliminary risk assessment process is shown in the Figure below.
Should I be paying for a Preliminary Risk Assessment?
Industry guidance states that preliminary assessments do not need to be undertaken by a UXO specialist. This is because in some cases it will be clear if a site is in a region of heavy bombing or has a former military use and therefore more detailed assessment is required.
However, for sites where there is a lack of obvious information available, such as rural areas or lightly bombed urban settings, appointing a UXO specialist is beneficial to ensure confidence in the findings of the assessment.
Given that preliminary risk assessments can be undertaken by non-specialists, it may be reasonable to anticipate UXO specialists to offer them free of charge.
Can my Preliminary Risk Assessment be computer/AI generated?
Human input is recommended to produce a thorough preliminary risk assessment.
Computer generated reports typically rely on compiled databases (i.e. regional bombing statistics, bomb risk maps, and bombing decoy lists).
These databases may be incomplete and contain inaccuracies, which if not checked can create unnecessary work or an unsafe environment. If a database isn’t actively maintained, then it will potentially be missing a potential source of UXO hazard, as new records are constantly being released into the public domain.
As no historical database is ever complete, such reports tend to err on the side of caution with their recommendations, advocating further work that may not be justified.
With the advent of AI there is the additional risk that a source is misinterpreted or misused (i.e. a Roman military camp being flagged as a source of UXO hazard).
In short, computer or AI generated reports may lack consistency and accuracy, and are reliant on datasets that may not be complete. Human input and scrutiny is key.
Should my Preliminary Risk Assessment assign a risk or hazard level?
Industry guidance is clear that the purpose of a preliminary risk assessment is to identify whether or not a detailed risk assessment is required.
A preliminary risk assessment should not be providing a site with a UXO risk/hazard level. It certainly should not be recommending any risk mitigation, as these will have been advised without a proper assessment. This may result in unnecessary mitigation works, or recommend techniques that do not effectively mitigate the UXO risk.
Only once a detailed UXO risk assessment is undertaken should a UXO risk/hazard level with appropriate recommendations be provided.
Conclusion: What Makes a Good Preliminary Risk Assessment?
To summarise, it is essential that the following conditions are satisfied to ensure a good quality preliminary risk assessment:
- Clear information has been provided as to whether the site may have been affected by military activity, or whether the site has potentially been bombed during WWI or WWII.
- The assessment has been undertaken by human researchers (as opposed to computer-generated reports).
- A simple yes/no answer has been provided as to whether a detailed UXO risk assessment is required.
If a preliminary risk assessment recommends that a detailed UXO risk assessment is undertaken, then a UXO specialist must be contacted.
Stay tuned to our blog series as we explore the process and requirements behind a detailed UXO risk assessment.
Do you need to understand the potential UXO hazard for your site? Request a free preliminary risk assessment today via our online request form: https://zeticauxo.com/pdsa-request-form/
Alternatively, get in touch with one of our UXO specialists via: uxo@zetica.com or 01993 886682.
