MINE INSPECTION REPORT SHOWS NO CHANGE

An inspection report on the Billingham Anhydrite Mine has shown it is in the same general condition as when it was last in use.

 

The report, commissioned by owners ICI and NPL Estates Limited, follows the temporary reopening of the mine over five days last September.

 

Carried out by specialist engineering and surveying consultants White Young Green, the 100 plus page study looked at physical conditions within the mine set against how the mine was last operated and reported on in the 1970s.

 

Simon Towers, Managing Director of NPL Estates Limited, said: “It was reassuring to see that in general the mine is in pretty much the same condition as it was more than 30 years ago. It gives us more information on which to base a decision on whether to proceed with reopening the mine on a commercial basis.

 

He added: “However, the findings of this report together with investigations into the viability of modern techniques available for waste management will be reviewed and considered before a decision is made to progress to the planning stages of this project.   With that in mind, a further decision is likely from NPL by the end of the first quarter this year.   This is only one stage in a process that is likely to take several years and we will need other, more detailed reports as we progress through the planning and environmental management stages.”

 

NPL Estates Limited, through its subsidiary NPL Waste Management, is considering using the mine for the disposal of low-hazard dry waste, subject to planning and regulatory approvals.

 

The conclusions of the report and a series of pictures taken during the inspection were yesterday shared with the planning and relevant regulatory authorities including Stockton Borough Council and The Environment Agency.   The agreement of these bodies would be required before any permanent re-opening could take place.

  

The Anhydrite Mine was operated between 1927 and 1971 and eventually closed when the two mine shafts were capped in 1978.   With a capacity of 11 million cubic metres, it is roughly the size of 4,400 Olympic swimming pools.

 

The mine is 2 miles long from north to south and up to 1 mile wide from east to west. Two thirds is under the Billingham GrowHow site with the rest covering the area towards the Cowpen Industrial Estate.   Only just over half of the rock was ever extracted from the mine – a total of around 33 million tonnes - leaving massive pillars to support the roof.

 

Ranging from a depth of between 130 metres and 280 metres below ground, rock was extracted using a ‘room and pillar’ method.

 

Anhydrite (or calcium sulphate) is extremely strong and geologically stable rock. It has roughly four times the compression strength of concrete. The product was formerly used to make cement and plasterboard and also as a source of sulphur in the manufacture of sulphuric acid and ammonium sulphate.