Mining and Cavity Risk Assessments
Assessing risks from historical mining activities and natural cavities is crucial for site safety. We offer detailed evaluations and risk assessments, including coal mining, chalk mines, iron mining in the Weald, and natural cavities.
The risk posed by historical mining activities and natural cavities varies significantly across the country. We offer a range of mining and cavity risk assessment services, including:
Coal Mining Risk Assessments
The Coal Authority is a statutory consultee for any planning application within a High Risk Area.
If your site is in a Development High Risk Area, as defined by the Coal Authority, you will need to submit a Coal Mining Risk Assessment (CMRA) to your Local Planning Authority.
Ashdown Site investigation undertakes Coal Mining Risk Assessments for residential, commercial and industrial properties, which include an assessment of the Coal Authority Mining Report, assessment of mining plans, a review of modern and historical published geological maps and review of technical reports/memoirs.
Chalk Mines
Historically, chalk deposits were often mined locally. Most commonly historical mines characteristically comprise a narrow shaft with a number of chambers radiating from the base. These structures are colloquially known as “deneholes”, “chalk-wells” or “chalkangles”.
Records pertaining to the distribution of these localised mines are incomplete, usually being limited to features marked as shafts or the occurrence of circular depressions on historic Ordnance Survey maps.
In the 19th century, economic expansion led to unprecedented demand for the supply of building materials including bricks. Yellow stock bricks were produced by adding about 15% chalk to the mixture and some brickfields had associated chalk quarries. Where space was limited, many works sunk shafts to mine the chalk. Whilst mines associated with brickworks are typically more recent than deneholes, their exact locations are also typically unrecorded.
Utilising comprehensive datasets, we can provide a detailed assessment of the risk posed by historical chalk extraction specific to your site.
Iron Mining in the Weald
The geological units of the Wealden Group were locally mined for iron during the early Roman period, the Medieval period and significantly between the 15th and 18th centuries. The locations of many of the workings are unknown.
The historical extraction was mostly from open pits excavated from surface, but during the Medieval period, extraction was increasingly from mines.
Detailed assessment of the risk posed by these historical mining hazards can be undertaken, making reference to comprehensive datasets, LiDAR data and other historical records, to provide a report specific to your site.
Natural Cavities
Natural cavities occur throughout the chalk deposits of England. Where present, cavities are usually found to be infilled with Quaternary Superficial Deposits though open voids are also present. Solution features can comprise pipes extending to several metres deep into the chalk or conical depressions and basin shaped structures.
Cavities known as “Gulls” may be present within the Hythe Formation deposits, notably on steep hillsides, as a result of mass movement.
Ashdown Site Investigation can provide detailed assessment of the risks posed by these natural ground hazards to assist the safe development of your site.
