Article Safety

Unexploded Ordnance – a Construction Industry Guide

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As the representative of the AGS on the project steering group for the forthcoming CIRIA construction industry guidance on UXO, Andy O’Dea of Peter Brett Associates LLP updates us on the scope of the guidance and the benefits it will bring.

In the March 2005 issue (number 49) of the AGS Newsletter, you published a letter from my colleague at Peter Brett Associates LLP (PBA), Richard Thomas, on the controversial issue of unexploded wartime bombs (UXBs).  It transpires that this was one of the contributing factors to CIRIA commissioning a research project to produce definitive guidance on the issue for the construction industry.  PBA has part funded the project and I have been involved throughout, representing both the AGS and PBA on the project steering group.  The final report is nearing completion and is likely to be published in the coming months.  I thought it was timely for me to write to update the AGS on the scope of the report and the benefits it will bring.

The assessment of risk associated with Unexploded Ordnance (UXO) is controversial and fraught with difficulties.  For example, several thousand items of ordnance are removed from construction sites in the UK each year (of which some 5% are live).  However, in the period 2006/2007 (readily available HSE records), no reported injuries to construction workers were attributed to incidents involving UXO.  This is in spite of other risks or accidents in the UK construction industry resulting in 77 fatalities, 3,711 major injuries and 7,108 other reportable injuries. Make no mistake about it, the risk associated with UXO is overwhelmingly influenced by the consequences of an event rather than the likelihood of encountering or detonating a device in the first instance.

Three main issues drove PBA to get involved in the project:

  1. A lack of any consistency in the assessment and reporting of UXO risk across the industry.
  2. An absence of scientific or methodical processes in the ‘black art’ of UXO threat assessment.
  3. The perceived conflict of interest in a UXO specialist providing advice on required mitigation measures and then offering contractor services to mitigate the risk.


We are pleased to say that all three issues have been addressed by the project guidance.

We feel that the report is a comprehensive and extremely useful piece of work that will help to dispel many of the myths surrounding UXO and allow future UXO risk assessments to be supported by a consistent and rigorous approach that is underpinned by scientific reasoning.  The report provides a comprehensive introduction to UXO and outlines the duties and responsibilities of the parties to a construction project in the context of UXO risk.  A clear and concise flow diagram outlines the risk management framework; from preliminary risk assessment (that can be carried out by a non-UXO specialist) through to detailed risk assessment, where required, (to be conducted only by a UXO specialist) and on to risk mitigation and implementation.  Each element of the risk management framework is described in full detail in subsequent chapters of the report.  Advice on emergency response planning and the appointment of UXO specialists is drawn out in the later chapters.

The report is supported by a dozen or so relevant case studies and especially important issues are emphasised in highlighted boxes.  Example risk assessment reports, verification reports and clearance certificates are provided in the appendices along with the ‘nuts and bolts’ of UXO survey techniques, equipment and limitations.

The report has been through a rigorous consultation process and has been distributed widely across the industry for comment on a number of occasions.  Consultation responses have been received from developer clients, regulators, consultants, contractors, infrastructure bodies, government defence organisations, academia and professional bodies such as AGS.  A special note of thanks goes to those at the AGS who have given their time and expertise in reviewing the report and making the consultation process a success.

This report presents a major advance in helping to provide a consistent and robust approach to the assessment of UXO risk in the construction industry and is to be welcomed.  Undoubtedly, it is a first step and further guidance will follow in time.  However, CIRIA Report RP732 Unexploded Ordnance (UXO) – a construction industry guide, is a big step in the right direction.

Andy O’Dea
Senior Associate
Peter Brett Associates LLP
17 September 2008