Unexploded ordnance (UXO) remains a persistent hazard across the UK and beyond, with the vast majority of items dating back to World War II. However, these remnants of conflict and military activity stem from a much wider range of sources than most people realise.
Sources of UXO
While World War II is the primary source of UXO found in the UK, many items originate from military training exercises that have taken place over the decades. Wherever land, marine, and air forces have operated, they have required space to practice using weapons and weapon systems. As a result, live and simulated munitions have been deployed across various training grounds.
In the UK, for example, contamination from Air Force bombing ranges occurred as recently as the 1990s. These aren’t just historical leftovers, they’re a result of continued defence activity.
In addition to training, other military processes have contributed to the presence of UXO. During post-war demobilisation, returning soldiers and airmen were processed through facilities designed to relieve them of any equipment or munitions they may have brought home as souvenirs. Not all items were properly collected, and some found their way into civilian hands.
Dumping Practices, Official and Unofficial
Another major contributor is the dumping of ordnance. Though never an officially sanctioned government disposal method, surplus stockpiles were sometimes discarded in designated dumping grounds. More commonly, unofficial dumping occurred when individuals, perhaps feeling nervous about keeping hazardous items at home, chose to dispose of them discreetly. For instance, many items have been thrown into canals, a practice that continues to pose risks today.
In some cases, former military personnel kept souvenirs that were later discovered after their death. Family members, unsure of what to do, sometimes turned these items in to authorities through informal amnesty arrangements. Others, however, disposed of them privately, leading to frequent discoveries of UXO during survey or by members of the public.
The Misconception of “Safe Disposal”
One common misconception is that disposing of ordnance in a body of water, such as a canal, renders it safe. In reality, these areas are frequently used by anglers and, increasingly, by magnet fishers—raising the chances of accidental discovery and detonation.
Marine Environment and Coastal UXO
The patterns are similar in coastal waters, particularly in Europe and the U.S. East Coast, with large quantities of UXO, most of which also date back to World War II.
Training grounds in coastal zones continue to be used even today. Projectiles are still tested, ranges are cleared, and both old and new munitions are handled several times a week. This ongoing activity, combined with decades of historical use, has created densely contaminated areas, especially near live fire zones.
For developers working on offshore infrastructure such as wind farms and power cables, this presents a unique challenge, with heavy constraints often resulting in conflicts of interest in the use of space. Many planned routes run close to or through exclusion zones where military activity is ongoing or recently ended. In these areas, investigations and surveys often uncover munitions. Some may be inert dummies, but others are live and potentially dangerous, especially when no complete records exist of what was fired, when, or where.
Training Munitions: Not Always Harmless
Importantly, not all training munitions are inert. While some simulation rounds used on dry land contain no explosives, others, particularly those launched from artillery or dropped from aircraft, include tracer pockets, a burning phosphorus element to make the projectiles path visible, or even small explosive charges designed to simulate impact. For example, a training bomb may mimic the flight path of a 500-pound bomb while weighing only 25 pounds, but it can still contain explosive components; critically, this means even training ordnance can present a real risk.
Conclusion
UXO remains a real and present hazard due to the long legacy of military activity, incomplete disposal practices, and ongoing training operations. Whether buried in farmland, resting in canal beds, or lying offshore near construction projects, these items continue to pose threats to public safety and infrastructure. Understanding the diverse origins and risks associated with UXO is a critical step in addressing the issue effectively and safely.
Written by Patrick Clark, Hydrofix Director and Richard Holmes Managing Director of RSK Ordnance Management.
Created from a Podcast transcript between Patrick and Richard, focusing on everything UXO.
