Frack fluid is the combination of water, chemicals and sand (or proppant) that is injected into a well to release the gas trapped within; water makes up much of this fluid. The chemicals used in frack fluid are carefully chosen to ease the production of gas from that well.
On May 9, 2014, the U.S. Environmental Protection Agency (EPA) announced it was preparing a stakeholder process to review the information on frac fluid. The EPA then held a 90-day public comment period on this issue. This comment period could be followed by a regulatory requirement that companies engaging in fracking must disclose the chemicals used during the process, a voluntary system, or a combination of the two.