Combe Down and Bathampton Down Quarries, Bath, Bath and North East Somerset, England, UKi

Regional Level Types
Combe Down and Bathampton Down Quarries	Mine (Backfilled)
Bath	City
Bath and North East Somerset	Unitary Authority
England	Constituent Country
UK	Country

Combe Down and Bathampton Down Quarries make up a 6.22 hectare (15.37 acre) Site of Special Scientific Interest (SSSI) in Bath and North East Somerset, England, important for its bat population. The disused quarries date from the 17th and 18th centuries and were the source of Bath stone for the city of Bath and elsewhere in the UK. A five-year project to stabilise the quarry workings was largely completed by November 2009.

The Great Oolite stone, used for building purposes, formed over 146 million years ago when the area was underneath a deep tropical sea on which ooliths were deposited. The ooliths bonded together to form the distinctive rock known as oolitic limestone or locally as Bath stone. The Romans found that it was easily worked and used it for important fortifications. During the 17th century, small quarries were opened, with major quarries being developed in the 18th century to produce the stone used for many of the buildings in Bath and elsewhere in the UK, including Buckingham Palace. Stone was extracted by the "room and pillar" method, by which chambers were mined, leaving pillars of stone to support the roof. These mines were once owned by Postmaster General Ralph Allen (1694–1764).

The mines contain a range of features including well preserved tramways, cart-roads and crane bases. The walls and pillars are studded with pick and tool marks and show evidence of the use of huge stone saws, all of which bear testimony to the variety of techniques used to extract the stone over their three hundred-year history.

No mine abandonment plans – either of the tunnels or the caverns, known as voids – were made prior to the 1872 Mining Act.

During 1989 a utilities contractor unexpectedly broke through into part of the mine complex whilst excavating a trench, which resulted in Bath City Council commissioning studies to survey the condition of the mines. It was clear that the mines were in very unstable condition, and some experts considered them to be the largest, shallowest and most unstable of their kind in Europe.

An underground survey of the Firs and Byfield mine areas was carried out in 1994, commissioned by Bath City Council. It was found that approximately 80% of the mines had less than 6 m cover, reducing to 2 m in some places. Irregular mining and robbing stone from supporting pillars had left the mines unstable.

In March 1999, the then Department of Environment, Transport and Regions (DETR) announced a Land Stabilisation Programme, based on the Derelict Land Act 1982. This was designed to "deal with abandoned non-coal mine workings which are likely to collapse and threaten life and property". Approximately 760 properties were included within the planning application boundary; estimates were that ca. 1660 people lived within this area, which also included a primary school, a nursery and three churches.

Foamed concrete was selected for the large-scale infilling of the old mine works: the single largest application of foamed concrete on a project in the UK. The work was largely complete by November 2009, by which time approximately 600,000 cubic metres of foamed concrete had been used to fill 25 hectares of very shallow limestone mine, making it the largest project of its kind in the world.

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