How to Manage UXO Risks on Construction Sites
When undertaking any construction project, safety is paramount. One of the most critical but often overlooked hazards is the presence of unexploded ordnance (UXO). This risk is particularly prevalent in regions with a history of conflict or military activity.
Managing UXO risks effectively is essential to protect workers, safeguard the public, and ensure project timelines and budgets remain on track. In this blog, we explore the key steps in managing UXO risks on construction sites and how Brimstone UXO can support you every step of the way.
Understanding UXO Risks on Construction Sites
What Are UXO Risks?
UXO refers to explosive ordnance which has been primed, fuzed, armed or otherwise prepared for action, and which has been buried, dropped, fired, launched, thrown, or placed in such a manner as to constitute a hazard and remains unexploded either by design, malfunction or for any other reason.
These hazardous items can remain buried for decades, posing significant risks during excavation or other ground-intrusion activities.

Why Do Construction Sites Face UXO Risks?
Many construction sites across the UK are at risk of UXO contamination due to:
- Historical bombing campaigns during WWI and WWII.
- Military training activities.
- Ordnance manufacturing and testing.
- Abandoned ordnance stockpiles.
These risks necessitate a proactive approach to UXO risk management, especially for projects involving significant ground investigations, excavation, piling, or drilling.
The Cost of Ignoring UXO Risks
Failing to address UXO risks can have severe consequences for construction projects, including:
- Increased costs: unplanned stoppages and emergency responses can strain budgets.
- Project delays: UXO discoveries often result in significant downtime while the suspected item is investigated and dealt with.
- Safety hazards: the most significant risk in ignoring UXO is safety. Disturbing an item of UXO can have devastating impacts, including injuries and fatalities.
- Reputational damage: failing to manage UXO risks responsibly can harm your company’s reputation and damage credibility.
Proactively managing UXO risks with Brimstone UXO’s expertise can help avoid these costly and dangerous outcomes.
Steps to Manage UXO Risks on Construction Sites
Conduct a UXO Risk Assessment
The first step in mitigating UXO risks is to conduct a comprehensive risk assessment on your site. A professional UXO risk assessment will evaluate:
- Historical records of military activity in the area.
- If allied and enemy action could have led to UXO contamination.
- If UXO contamination on site has already been mitigated.
At Brimstone we offer two types of UXO risk assessment, enabling construction companies to understand the specific risks associated with their site before work begins.
A Preliminary UXO Risk Assessment is usually the first step for construction and development projects. Our research team will take an overview of your proposed site and investigate any military activity on or near your land through primary and secondary historical sources. They then use this information to assess the UXO risk on your site and identify if further, more in-depth research is required. With a 24 to 48-hour turnaround, a Preliminary UXO Risk Assessment is the most cost-effective and fastest way of determining the UXO risks on your site.
If your site is a former military site, or the preliminary risk assessment identified possible UXO contamination, you will need a Detailed UXO Risk Assessment. This takes an in-depth look at the range of ways WWI and WWII action, along with Allied activities, could have led to UXO contamination on your site. It also considers how your proposed works affect the likelihood of encountering UXO.
If your risk assessment returns a low-risk rating, this is deemed ‘acceptable’ and you can continue with your project without further UXO support. However, if it comes back as high or moderate, you will need to take further action.

Pre-Construction UXO Surveys
Before breaking ground, we might recommend that a thorough UXO survey be conducted. This survey explores beneath the surface and detects buried ferrous objects that could be unexploded ordnance.
Surveys are a crucial step in ensuring the safety of construction projects in areas with potential UXO contamination. Imagine the disastrous consequences if a piling rig or digger were to strike an unexploded bomb beneath the surface. By identifying UXO hazards before construction work begins, we can protect workers and the wider public from potential harm.
At Brimstone our surveys come in two key forms:
- Non-intrusive surveys which can safely detect shallow buried UXO without having to disturb the ground. This can be conducted in a pushed, towed or aerial format and is suitable for greenfield land.
- Intrusive surveys which involve using our CPT Rigs to physically penetrate the ground to detect UXO hidden deep below the surface. This methodology is suitable for brownfield sites or sites with made ground.
Once the survey is complete, our geophysics team will process the collected data. A magnetic field false colour map is generated which highlights any ferrous anomalies, and these are then compared against a bank of known UXO signals using our specialist computer model.
If we identify targets that require further investigation, we will recommend that our engineering team is deployed back to your site to carry out a target investigation. If no anomalies are identified, and there are no further recommendations for UXO risk mitigation, you will be issued a UXO ALARP certificate and can continue with your planned works.

Engage UXO Specialists for On-Site Support
Often a follow-up activity to risk assessments or surveys, but sometimes a stand-alone service, on-site UXO support is another way you can mitigate UXO risks on construction sites. At Brimstone our on-site support usually involves a UXO engineer attending your site to either:
- Conduct a watching brief: this involves the continuous monitoring of ground intrusion activities by a qualified UXO engineer, safeguarding your project from the potentially dangerous consequences of an unexpected UXO encounter. If a suspicious item is uncovered, our engineer can quickly establish if it’s UXO or not, preventing costly delays and ensuring people are kept safe.
- Provide borehole support: using a down-hole probe our engineer will clear borehole positions as they get progressively deeper. We can support the use of cable-percussive, rotary, window and windowless samplers and other drilling methods to ensure that all operatives are kept safe from UXO.
- Carry out a search and clear: using advanced search equipment and techniques we quickly mark, excavate and identify UXO targets in real time.
At Brimstone our engineers are highly trained and experienced, offering peace of mind and ensuring the safety of all personnel.

Develop a UXO Risk Mitigation Plan
We would always recommend that sites with an intolerable risk level create a tailored UXO risk mitigation plan. Despite the best precautions, the discovery of UXO may still occur on a construction site that has undertaken UXO risk mitigation steps. Having an emergency response plan in place is therefore essential.
This plan should outline:
- Procedures for identifying and reporting suspected UXO.
- Emergency response protocols.
- Safe working distances and no-go zones.
- Evacuation protocols.
- Communication with UXO specialists.
- Coordination with local authorities and emergency services.
Brimstone UXO supports construction teams in developing and implementing comprehensive emergency plans to minimise disruption and risk. We also can provide rapid response services by prior arrangement.
Implement UXO Awareness Training
Ensuring that all personnel are aware of UXO risks and know how to respond appropriately is an essential aspect of risk management. UXO awareness training should include recognising potential UXO, understanding its hazards and the importance of following reporting and evacuation procedures.
At Brimstone we are proud to provide the first online UXO Awareness Course in the UK. The course consists of five modules of in-depth information and aims to teach candidates about UXO risks, why UXO might be present on a construction site, and how to respond to a UXO incident safely. Our course is approved by the International Institute of Risk & Safety Management and is certified by The CPD Certification Service.
We also include UXO safety awareness briefings in all of our usual on-site services, and as a stand-alone service when required. Our briefings cover general risks and hazards, basic UXO identification, and actions to take in the event of a UXO encounter.
If you are looking for more tailored training, Brimstone can provide site-specific training packages. These are an extended version of our safety briefs and focus on the context of your specific site. Lasting for approximately two hours, our UXO engineer will cover explosive munitions principles, sources of contamination, basic UXO identification, safety measures and specific historical information on your site obtained from primary and secondary research.
In the construction sector, it is essential that unexpected situations are dealt with quickly and confidently. Ensuring your teams are aware of UXO risks and providing them with the confidence to handle situations involving potential UXO can be a game-changer, ensuring both your team’s safety and the success of your project.
Working with Brimstone UXO
Managing UXO risks on construction sites is a complex but critical process. By conducting thorough risk assessments, implementing tailored mitigation plans, and engaging professional support, construction companies can ensure the safety of their teams, the public, and their projects.
At Brimstone UXO, we understand the complexities and challenges of managing UXO risks. With a proven track record across diverse projects, from urban developments to remote ground investigations, Brimstone provides a range of comprehensive services to address every stage of UXO risk management.
Contact us today to learn how we can support your construction project and ensure a safe and successful outcome.
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