Monday, 31 July 2017

AI’s extraction plans are now down to 6 fields and 1.1 million tonnes

Aggregate Industries' planned extraction area for Straitgate Farm has shrunk - from 25.6ha to 22.6ha.

AI doesn’t tell us by how much this has reduced the total available resource, but we can work it out from a couple of documents. Appendix C tells us that the revised 1st phase now has 177,000 saleable tonnes, and the 2nd phase 363,000. The 3rd phase, which the Supporting Statement tells us "is expected to yield circa 740,000 tonnes of as raised sand and gravel", equates to 592,000 saleable tonnes after allowing for 20% waste. This gives a new total of 1.13 million saleable tonnes.

That's 500,000 tonnes less than AI’s 2015 planning application claimed could be recovered, and 90,000 tonnes less than the current application first put forward.

This of course assumes a quarry base:
If 1m of material was left above the MWWT, as is standard for other quarries where groundwater receptors are at risk, the resource available would be much less:
... excavating to a level 1m above the highest winter water table level would reduce the saleable tonnage by approximately 300,000 tonnes 8.77
As we have posted before, Straitgate Farm has already been a disaster for AI; when, English China Clays - AI’s predecessor - bought the farm in 1965 it believed it could lay its hands on 20 million tonnes.