Wednesday, 10 February 2016

Great crested newts... and rising water tables

Aggregate Industries is desperate to use Blackhill beyond 2016 to process material from Straitgate, and has put up a range of arguments as to why it couldn’t use its derelict site at nearby Rockbeare instead; one of these arguments is the presence of great crested newts:
It has been demonstrated that processing at Rockbeare is not physically possible due to a lack of silt space and clean water storage, insufficient stocking and processing area and the presence of great crested newts in existing ponds. 8.37
Natural England has demolished these arguments and doesn't see GCNs as a constraintBut guess what? Tarmac doesn’t see GCNs as a barrier to working either. It’s been working with them for years at a quarry in Cheshire, where "a number of ponds, pools and ditches have been created at Crown Farm Quarry as a result of historic quarrying activities". There’s even a paper on the subject:
The discovery of a widespread population of great crested newts at Crown Farm Quarry could have been a major constraint to the operators at this mineral extraction site. However, with early involvement of ecologists, appropriate management, innovative mitigation measures, and a positive approach by Tarmac, this potential constraint has become a success story.
But why all these "ponds, pools and ditches"?
An unexpected rise in the water-table has also contributed to the formation of these waterbodies.
An unexpected rise? It's hardly surprising. At Straitgate, hydrogeological consultants are trying to predict the maximum winter water table across some 63 acres with just six data points from around the perimeter. It's obviously not possible with any precision, however much their maps and contours would like to give the impression that it is. It’s one of the reasons why 1m is typically left unquarried above the maximum winter water table where private water supplies are at stake.

AI now says it has no intention of leaving this 1m unquarried at Straitgate. Perhaps it should ask itself, what would happen if there was an "unexpected rise in the water-table" here - and the void had been backfilled with just 1m of soil? What would happen to the integrity of private water supplies to 106 people, for example from animal faeces, nitrates or other pollutants? What would happen to restoration to any future farming use? What would happen to airport safeguarding?

What happened to dry-working at Thorn Trees and Venn Ottery? Unexpected rises in the water-table?