MITIGATING RISKS TO ESTABLISH SAFER GROUND
Specialist UXO borehole support, watching briefs and end-to-end UXO mitigation projects across the UK.
Specialist UXO borehole support, watching briefs and end-to-end UXO mitigation projects across the UK.
Please reach us at ops@recce-si.co.uk if you cannot find an answer to your question.
Unexploded Ordnance (UXO) refers to munitions that were deployed but failed to detonate. In the UK, this is most commonly associated with aerial bombs from World War II, although other items such as projectiles and small arms ammunition may also be encountered.
During WWII, thousands of tonnes of bombs were dropped across the UK. Many failed to detonate and remain buried. In areas of made ground or soft soils, these items can be present at significant depth and may only be encountered during intrusive works.
UXO risk is typically assessed through a Desktop Study (Phase 1 or Phase 2) in line with CIRIA C681. This considers historical bombing records, ground conditions and previous site use.
At the earliest stage possible, ideally during planning or design (RIBA Stage 2). Early assessment allows risks to be managed proportionately, avoiding delays and unexpected costs later in the project.
A UXO Watching Brief involves a qualified UXO specialist supervising intrusive works such as excavation or remediation. The specialist provides:
Typically where there is a moderate UXO risk and intrusive works are taking place, such as:
UXO Borehole Support is used during drilling operations and involves downhole magnetometer surveys (e.g. using a Sensys SBL10) to detect anomalies before drilling progresses. This ensures that drilling does not strike buried UXO.
This is a targeted clearance method using a CPT rig fitted with a magnetometer cone. Surveys are typically carried out in a grid pattern to achieve clearance to the Maximum Bomb Penetration Depth (MBPD) in line with CIRIA C681.
MBPD (Maximum Bomb Penetration Depth) is the maximum depth a bomb could have penetrated based on ground conditions.
It is typically defined as achieving:
All works stop immediately and an exclusion zone is established. A structured Emergency Response Plan (ERP) is followed, which may involve:
No. UXO risk can only ever be reduced to As Low As Reasonably Practicable (ALARP).
Clearance is always limited to:
Yes:
This is why different mitigation strategies are required depending on the activity.
We are a small, responsive team and can often mobilise at short notice, depending on project requirements and location.
Yes. We operate nationwide and regularly support projects across England, including infrastructure, remediation, geotechnical and utilities sectors.
Yes. We regularly integrate UXO mitigation with:
This provides a more efficient, coordinated approach to ground investigation.
Costs vary depending on:
We provide tailored, no-obligation quotations based on your specific project.
Typically:
Yes. We’re always happy to provide free, no-obligation advice to help you understand your risk and the most appropriate mitigation strategy.