Fracking has been in the news a lot, but there is one part of the process that hasn't yet been scrutinized - frac sand.
Fracking solution contains water, frac sand and chemicals. It is pumped at high pressure into the borehole to crack the shale rock and release the gas or oil. The sand keeps open the tiny fractures made in the shale rock by the pressure of the liquid and prevents them closing again. This allows the gas or oil to flow out and be extracted.
The sand used must have just the right grain size and an almost perfectly spherical shape to be used in the fracking process, not all the current sources of sand in the UK are suitable for this. According to Clive Mitchell, at the British Geological Survey possible sources of the frac sand in the UK are:
Huge amounts of sand are used in the fracking process. The US produced more than 49m tonnes in 2012 for use in their fracking operations.
Removing frac sand usually requires strip mining. The vegetation, soil and bedrock at the site are removed in the mining process. This destroys the local habitat and affects local residents. The sandstone is then crushed and washed which consumes vast amounts of energy and water. The sand is then loaded into lorries or trains to be transported to the fracking sites. Mining operations also create noise and light pollution in previously rural areas.
Marcia Bjornerud, Professor of Geology at Lawrence University, says that quarry employees and local residents are exposed to silica dust during the mining process. Breathing in silica dust can cause an irreversible lung disease called silicosis and other health problems.