(sources: Appendix C, Caudrilla’s Balcombe planning permission & Cuadrilla’s submission to the Select Committee on Energy and Climate Change)
Earthquake firm Cuadrilla plans to extract gas from Balcombe just 500 feet below the local aquifer.
Drilling documents (see p12 of the pdf) reveal the company plans to test frack at just 1831 feet – 831 feet from the company’s deepest estimate of water supplies. The company says fractures extend up to 300 feet (see 5.6.11 of the document), bringing the gas-bearing cracks to within 531 feet of water sources.
Drilling documents supplied with Caudrilla’s Balcombe planning application show the company intends to test the Portland Beds, 1627 to 1831 feet below the village. Also contained within these documents are the provision to ‘stimulate’ – a euphemism for fracking.
In its submission to the Energy and Climate Change Select Committee in June 2011, the company claimed that fractures caused by fracking extend 200-300 feet from the borehole (others claim they can extend much further).
In the same submission the company estimated that aquifers reside at a maximum depth of 1000 feet.
So 1831-300-1000 = 531 feet below the aquifer.
A key ambition in their submission to parliament was to convince MPs that fracking did not threaten water supplies. Referring to the company’s sites in Lancashire, the company stated: “the shale geological formations where fracing takes place tend to be located at depths of at least 5,000 feet below the surface ” and “there are thousands of feet of impenetrable rock between shallow water aquifers and fractures created by the fracing process.” (see 5.6.11 again)
Not so in Balcombe. With the US EPA recently finding aquifer contamination from a well of similar depth in Pavilion, Wyoming, Cuadrilla’s plans in Balcombe look more and more reckless.