Navigating CIRIA C681: A Developer’s Guide to UXO Risk in High-Risk Groundworks

Feb 20, 2026UncategorizedComments (0)

Navigating CIRIA C681: A Developer’s Guide to UXO Risk in High-Risk Groundworks

In the UK construction industry, the "low-probability, high-consequence" nature of Unexploded Ordnance (UXO) makes it a unique challenge. For projects involving high-risk groundworks, the difference between a smooth site start and a costly, dangerous shutdown often comes down to one thing: CIRIA C681 compliance.

As a specialist providing UXO mitigation across the UK, we know that understanding your legal and safety obligations is the first step to a successful build.

What is CIRIA C681 and Why Does it Matter?

CIRIA C681 is the industry-standard "Code of Practice" for managing UXO risks in the UK. It outlines a four-stage process designed to protect site workers, the public, and your project timeline:

  1. Preliminary Risk Assessment: Identifying if a site has a history of military activity or bombing.

  2. Detailed Risk Assessment: A deeper dive into historical records and site-specific factors.

  3. Risk Mitigation Strategy: Deciding on the best physical actions to manage the threat.

  4. On-site Support: Practical intervention, such as a UXO Watching Brief.

Following this framework isn't just best practice; it ensures you meet your legal duties under the CDM 2015 Regulations.

Managing High-Risk Groundworks with a UXO Watching Brief

When a site is flagged as "High Risk," you need more than just a report—you need boots on the ground. This is where a UXO Watching Brief becomes your most valuable asset.

Unlike generic site monitoring, a UXO specialist provides real-time vigilance during intrusive works (like piling, trenching, or bulk excavation). If an anomaly or potential UXO is encountered, our specialists can:

  • Identify the item immediately.

  • Establish safety cordons to protect personnel.

  • Liaise with the authorities to minimise site disruption.

By having a specialist integrated into your groundworks team, you prevent the panic—and the associated costs—of an unmanaged discovery.

Specialist Soil Screening: Precision over Volume

While some projects require massive mechanical trommel screening, many high-risk sites benefit from a more surgical approach. At UXOS, we specialise in Advanced Soil Screening using manual conveyor picking lines.

This method allows for a much higher degree of accuracy in identifying smaller ordnance or fragments that automated systems might miss. It’s about ensuring that every cubic metre of spoil is truly "cleared" before it leaves the site or is repurposed.

Your UK-Wide Partner in UXO Safety

Based in the South East but covering the entire UK, we bring local knowledge to a national standard. Whether you are breaking ground on a historical bombing hub in London or managing a brownfield redevelopment in the Midlands, our goal is the same: Zero Harm and Zero Delays.

Get a CIRIA C681 Consultation Today

Don't leave your site safety to chance. For expert advice on UXO Risk Assessments, Watching Briefs, or specialist screening, get in touch with our team: