Local people relying on the Straitgate aquifer for their drinking water will have read that AI’s planning application proposes to quarry down to the maximum winter water table level, not 1m above which has been typical at other nearby sites. AMEC's Hydrogeological Assessment says:
Mineral extraction to the high groundwater level surface contoured from maximum groundwater levels from all data would be dry for the vast majority of time... 4.2
Whilst the Environment Agency’s response to the application recommended that "a Section 106 agreement is put in place prior to the commencement of the works [requiring] the 'making good' of any derogation to an agreed list of water supplies by the provision of alternative supplies", the agency made no reference to AI maintaining 1m of unsaturated material to safeguard supplies.
We have since asked the EA for clarification, and have been advised that:
Aggregate Industries have proposed to stop quarrying a metre above the water-table. We expect DCC to make this a condition of any permission that is granted.
In which case, AI should now tell us the size of resource left at Straitgate - the size of the 'benefit' that should be weighed against the proposal's considerable harm. According to AI, the site contained "in the order of 1.2Mt of saleable sand and gravel" 3.8 with mineral extraction to the high groundwater level; a 1m depth of sand and gravel across a 25.6ha extraction area equates to about 0.5 million tonnes.
