A "very full and careful survey of the resource" was made for English China Clays’ planning application to quarry Straitgate Farm in 1967 – a planning application that was subsequently refused following a public inquiry in 1968. From this survey, geologists clearly understood there to be faulting across the site:
In 1990, the site was extensively surveyed again for the Parkhouse Report. The report – which contains groundwater data that must now inform Aggregate Industries' current application – noted:
4.1.3 It is not possible to predict accurately the location of the faults with the available density of borehole information, however, there is some evidence for the inferred faults F1 to F4 shown on Figs. 2, 3 and 4.
In 2011, Aggregate Industries produced another map, indicating north-south faulting. This has been superimposed on the 1967 map, shown above. The main north-south faulting is located in the same approximate area as in 1967, but what has happened to the other faulting?
In 2015, consultants from Amec Foster Wheeler – before their document was whitewashed – stated:
Much of the local faulting is unmapped in this area but at Straitgate, some additional faulting (as compared to BGS mapping) has been identified by AI from their geological data and interpreted from examination of groundwater levels across the Site.
Two main N-S trending faulted zones are identified from BGS and AI mapping on either side of the Otter Sandstone outcrop block east of the Site… There is also likely to be other unmapped local faulting.
Why is faulting important? Here's one reason from AFW's report:
... there is uncertainty about how smooth the transition is [of groundwater elevations from west to east] because... there is possibility for steps in the water table related to faulting.
What allowance has been made in the MWWT for this? None.
What other reason might there be? As we have previously posted:
At Marshbroadmoor, the original planning application promised 1.1 million tonnes, but, due to 'geological faulting', no more than 200,000 tonnes ever came out.
What allowance has been made in the resource assessment for this? None.
So, knowing how critical faulting is to the yield and success of a mineral operation, knowing that AFW recognised the likelihood of "other unmapped local faulting", where has the 1967 faulting gone?
