Shale Gas

Additional Evidence from Cuadrilla Resources Holdings Limited (SG 08A)

31 January 2011

To be read as an annex to original evidence dated 13 January 2011


Note on the specific composition of Cuadrilla’s fracing fluid

Cuadrilla’s fracing fluid is a minimum of 99.75% water and sand.

The remaining 0.20% - 0.25% is comprised of three additional ingredients:

· Around 0.075% is a friction reducer called Polycrylamide. Polycrylamide is found in facial creams (available on the High Street and produced by major brand names), soil sealants and contact lenses.

Two other chemicals may be used:

· Around 0.005% is a biocide used at this very low concentration. This will be used if and only if the domestic water from United Utilities is not pure enough. But if it is sufficiently pure the biocide will not be used.

· Around 0.125% is a weak hydrochloric acid to help open the perforations to initiate frac fluid injection and again will only be used if needed. This is the same acid that can be used in ‘drinking’ water wells to stimulate water production, and in some cases used in swimming pools. It is also the food additive E507 that is commonly used in UK food products.

January 2011