Throughout the North of England there are so many towns, villages and rural locations with a proud history of coal mining.

But where mine shafts have been sunk and coal extracted, it is likely that there will be voids or ‘workings’ lying under the surface. In such cases, where coal extraction has occurred at shallow depth, generally considered to be less than 30 m below rockhead, they have the potential to represent a significant risk to the stability of the ground, as voids can often collapse and migrate towards the surface.

An awareness of the initial signs of possible mining subsidence and ground instability can enable action to be taken at the earliest opportunity, reducing the possibility of injury or damage to people and property.

Coal mining instability at the surface will initially be evident in the form of localised areas of sunken ground (which may be susceptible to standing water), deformation of the surface or structural cracks in existing buildings.

Should a possible hazard be identified as a result of historic coal mining activity, it is important to ensure the safety of everyone on site with the following precautions:

1. A safety cordon should be erected around any area of possible instability.
2. The incident must be reported to site management and Safety, Health, Environment and Quality (SHEQ) department immediately.
3. The Coal Authority should then be informed. Emergency 24-hour help line: 01623 646333

It is the duty of the Coal Authority to resolve the impact of historic coal mining activities, such as repairing mine entry collapses, shallow mine working collapses and dealing with gas or water emissions.

Once a site is secure, the Coal Authority will determine if the incident is as of a result of previous coal mining activity. Ground investigation works may have to be undertaken in order to assist in the determination of the cause of the instability and any appropriate remediation works required.

The Coal Authority have a responsibility to undertake the works as soon as possible and to inform all stakeholders both prior to the works start and during the works. In all but very exceptional circumstances, the works will be undertaken at the Coal Authority’s expense.

In exceptional circumstances, the Coal Authority may have to ask the occupier to temporarily evacuate part or all of the premises and if necessary they have an obligation to arrange alternative accommodation whilst carrying out an inspection of the site.