China Clay Mining

The St. Austell area in Cornwall is famous for its association with china clay where rich deposits of Kaolin have been mined over the centuries. The mines have been so ingrained into the Cornish economy that pretty much everybody in the local area either worked for companies involved in the china clay industry or had relatives that worked in the industry. My father for example worked at Melba Pit and I had cousins who were in the design section at the engineering works.

The extraction of china clay continues today and enormous pits extract huge volumes of this white gold. You may have caught sight of the extent of these pits in the recent television documentary by Simon Reeve1. We can see the legacy of workings in the form of white pyramids and overgrown pits partially filled with inviting but treacherous turquoise coloured ponds and lagoons. The world famous Eden Project lies in a former china clay pit. These features are easy to spot and provide a nostalgic window into the past, however, what are the things that we cannot see? Where are the mine workings that lie beneath that can cause potentially catastrophic settlement and subsidence events, that could lead to harm to human health to property and infrastructure?

China clay tip, St Austell, Cornwall

The team at Mining Searches UK have built up an extensive archive of china clay plans and charts. From this information we can assess where more modestly sized clay pits long since infilled, china clay waste tip mounds, adit drainage tunnels and shafts lie.

You may ask ‘yourself why this might be important?’. The answer lies in the fact that extensive residential and commercial development of the St.Austell area has happened in the last 50 years. That development is happening in the areas formerly located where the china clay has been extracted and so to be able to accurately locate the workings, assess the risks and remediate the workings, to bring the land back into viable use, is essential.

In the context of the conveyancing process, The Law Society handbook recommends the following2:

A property should be searched to identify whether further investigation of site-specific ground instability risks is required.

If a property is located within an area where ground instability risks are likely to occur, solicitors should consider further investigation of the risks present. This may include obtaining a site-specific report from a commercial search company; residential and commercial search products are offered by a number of search providers. Search providers often offer an initial risk assessment of the information provided in the report. An assessment should include a professional opinion of whether the property will be affected by mining or natural ground stability and whether there is likely to be any effect on the value or enjoyment of the property.

By purchasing our new GeoRisk report you will be made aware of these risks. The information contained in the report identifies recorded mine entries such as shafts and adit portals as well as recorded clay pits and tips. These are depicted on a variety of different sources of information taken from mine plans, geological plans and from information including Groundsure’s unique historical land use data and their complete suite of historical Ordnance Survey maps.

Mining Searches UK has undertaken site investigations for large areas that have been developed, for over 40 years. This is important to a purchaser because it means we will have physically assessed the ground, if china clay workings have been identified, they will have been made safe as part of the development and there will be documents to validate that process.

This provides the purchaser with assurance and peace of mind, and benefits the solicitor who gets a quick, all in one solution, typically within 24 hours, to cover the risk from mining related aspects.



1. BBC Documentary: Cornwall with Simon Reeve 8 November BBC2:
2. The Law Society 2020. The Conveyancing Handbook 27th Edition