Specially formulated lubricants are used in fracking, which involves pumping water, fine sand and fracking fluidsunderground to split open oil- and gas-bearing rocks.
In general, shifting the balance of fluidsunderground -- whether taking more out of the ground than is put back in or vice versa -- is likely to trigger seismic activity, the report concludes.
In its review of incidents of drinking water well contamination believed to be associated with hydraulic fracturing, EPA found no confirmed cases that are linked to fracturing fluid injection into CBM wells or subsequent underground movement of fracturing fluids.