Hydraulic fracturing  -- a process in which water, sand and chemicals are pumped deep underground at high pressure to break rock and release natural gas -- is controversial because of the secrecy surrounding the fluids and because the process is exempted from protections of the Safe Drinking Water Act and thus from regulation by the Environmental Protection Agency. Congress is currently considering legislation to address these issues out of concern that fracturing, and the fluids and waste that are part of the process, may be contaminating drinking water in several states . . . .
One of the public policy problems connected with the fracking process is that the fluids, materials, and procedures used are claimed as proprietary -- they are not entirely open to public debate, making citizen deliberation more difficult.
Abrahm Lustgarten, "16 Cattle Drop Dead Near Mysterious Fluid at Gas Drilling Site," ProPublica, 30 April 2009.