April 1, 2025
Post-Webinar Review: Assessing and Mitigating Risks from Coalfield Areas
On 1st April 2025, the British Drilling Association (BDA) hosted an informative and engaging webinar, entitled “Assessing and Mitigating Risks from Coalfield Areas”. Delivered by experts from the Mining Remediation Authority (MRA) — Helen Bennett (Technical Team Leader), Philip Broughton (Technical Manager), and Riwilo Masulani (Principal Permitting Manager) – the session provided critical insights into managing legacy mining risks in today’s built environment.
The subject is of increasing importance, as urban expansion, infrastructure schemes, and housing delivery continue to push development into areas underlain by historic coal mining activity. With recent incidents, such as a 25-foot-wide collapse in Bishop Auckland due to mine failure, fresh in the public mind, the significance of rigorous assessment and informed mitigation could not be more apparent.
Understanding the Role of the MRA
The Mining Remediation Authority, a non-departmental public body sponsored by the Department for Energy Security and Net Zero (DESNZ), plays a crucial role in regulating and advising on development over former mining land. The MRA contributes to the delivery of several government strategies, including the Ten Point Plan for a Green Industrial Revolution and levelling up initiatives. It also operates over 80 mine water treatment schemes across the UK, treating over 220 billion litres of mine water annually to protect drinking water, rivers, and ecosystems.
The MRA also functions as a statutory consultee in the planning system. With 11% of the UK’s landmass lying within coalfield areas, and 15% of that land falling into a designated Development High Risk Area (DHRA), the Authority is integral to ensuring that any new development is both safe and structurally sound.
The Importance of a Coal Mining Risk Assessment (CMRA)
A key message from the session was the necessity of undertaking a Coal Mining Risk Assessment (CMRA) for most planning applications within DHRAs. The CMRA is a desk-based, interpretive report, prepared by a suitably qualified and experienced person, which reviews all relevant data, identifies potential hazards, and proposes necessary site investigations or mitigation works. Crucially, a CMRA must be completed before a development layout is finalised, allowing risks such as shallow workings or mine gas to be fully accounted for in the design.
Attendees were reminded that the onus lies with the developer or their professional advisors to provide robust evidence and site-specific interpretations. The MRA will only comment on planning applications when formally consulted by the Local Planning Authority (LPA), and only on the information provided within the public domain.
Identifying Risk: Features to Consider
The webinar explored in detail the types of mining-related hazards that must be evaluated in a CMRA. These include:
It was emphasised that the absence of ‘reported’ features does not mean absence of risk, particularly in areas where records are poor or non-existent. Similarly, the existence of historic treatment records for a mine entry does not imply that it is safe for redevelopment — further verification is often required.
Data Sources and Interpretation
Participants were guided through a wide range of data sources available to support the CMRA process. These include the MRA Interactive Viewer, historical abandonment plans, borehole logs, BGS mapping, LiDAR data, and local knowledge. Importantly, the presenters highlighted the need for critical engagement with source material — noting that no two abandonment plans are the same, and that some contain vital information not captured in summary mining reports.
Examples were shared of 19th century plans from Wakefield and Ayrshire, modern “flat sheets” from Gateshead, and opencast maps from Derbyshire — demonstrating the variability in format and content. Consultants are encouraged to undertake their own detailed interpretations, rather than accepting historic conclusions at face value.
Linking CMRA Findings to Site Works
A well-constructed CMRA can lead to both time and cost savings if risk features are identified early. For example, if the need for proof drilling, grouting, or gas monitoring is identified from the outset, this can be incorporated into the broader ground investigation programme, reducing duplication and delay.
Examples from across the UK — including South Wales, Sheffield, and Staffordshire — illustrated how features like outcropping seams, unrecorded entries, and mine gas can significantly influence development outcomes. The presenters also addressed scenarios where recorded mine features are not found on site, stressing the importance of reviewing search methodology, site boundary coverage, and construction history before ruling out their presence.
Planning Takeaways and Professional Responsibilities
The speakers made it clear that a CMRA is a validation requirement in most DHRA planning applications. This is not a box-ticking exercise; it must be grounded in good science, local understanding, and a proactive approach to site-specific investigation. The developer — or their consultant — bears ultimate responsibility for ensuring the stability and safety of proposed structures.
Additionally, the webinar underscored the need to consider non-coal mining risks, especially in areas where other extractive activities have occurred. The MRA does not currently comment on non-coal features, but that does not negate the risk from other underground legacies.
Updates to Permitting Fees
Finally, the MRA outlined several key changes to its permitting charges for 2025. These include a general 20% uplift across most fee categories, as well as new or revised charges for variations and unrecorded mining features. The minimum charge for a new application involving an unrecorded feature now stands at £162, with a £72 minor variation fee where appropriate. Express and expedited application charges remain in place, calculated at four times and two-and-a-half times the standard rate, respectively.
A clear understanding of these costs — and the triggers that generate them — is essential for developers planning works that require MRA permits.
In Conclusion
This webinar provided attendees with a well-structured and deeply informative overview of risk assessment and mitigation in coalfield areas. The clarity of presentation, real-world examples, and open invitation to seek further guidance made it an invaluable resource for those engaged in planning, design, geotechnical investigation, and development.
As the drive to build on brownfield sites accelerates, and government targets demand swift and sustainable delivery of housing and infrastructure, practitioners must be equipped to identify, understand, and manage mining legacy risks. Engaging with the MRA at an early stage — and investing in a thorough CMRA — is not only best practice but a necessity in safeguarding future development.
For more information, the following resources are recommended:
To watch the webinar, visit: https://www.britishdrillingassociation.co.uk/news/bda-webinar-assessing-and-mitigating-risks-from-coalfield-areas-1st-april-2025-2/
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