Published November 2024. This guidance replaces ‘Guidance on the Risk of Unexploded Ordnance (UXO)’ which was published in January 2019.

Between 2006 and 2008, 15,000 items of unexploded ordnance (UXO) were removed from UK construction sites, ranging from high explosive aerial delivered bombs, to mortars and grenades. Of these 5% were estimated as being fully functioning. UXO occurrences can cause severe delays, and in the extreme cases can create high profile incidents affecting those on the site and parties beyond the site perimeter, with implications for the safety of people and property. For example, the removal of a 500kg (SC-500) WWII bomb from a garden in Plymouth, UK in February 2024. The UXO was carefully loaded on to a lorry, driving it slowly to the local slipway so it could be loaded on to a boat, taking it out to sea, so it could be safely detonated. This affected 10,300 people within an exclusion zone.
This AGS guidance provides the process for considering UK land based UXO only (including working adjacent to, or over inland water). Numerous UXO items are washed up on the UK shores and therefore, any projects that involve working within sea, foreshore or on beaches should undertake a separate maritime UXO assessment (mines, torpedoes, defensive training / action, off shore ordnance dumps etc; as detailed in CIRIA (C754) Assessment and management of unexploded ordnance (UXO) risk in the marine environment. Specialist assistance should be sought for these assessments.
UXO risk is most significant on projects involving excavation work. However, it is feasible that the risk could result from non-intrusive site walkovers or other survey work and in this event a Discovery Protocol (see CIRIA C785 in Section 1.2) should be followed, unless other procedures are imposed by the persons in control of the Site.