Investigations,have, found fracking to be the common thread in more than 1,000 cases of water contamination across seven states. It includes dozens of cases of well failures in which the concrete or steel meant to protect aquifers cracked under high pressure.
Surface and groundwater supplies are also at risk. An estimated 10 to 90 percent of fracking fluid is returned to the surface during well completion and subsequent production, according to a 2011 public health report on natural gas operations.
Natural gas is mostly methane, and the potent greenhouse gas methane has been leaking from wells at twice the rate of fracking industry claims, according to a 2012 study published in the journal Nature. Methane traps 21 times more heat than CO2. Read more about these ten scariest chemicals Methanol, BTEX compounds, Diesel fuel, Lead , Hydrogen fluoride , Naphthalene , Sulfuric acid, Formaldehyde , Crystalline silica , Unknown chemicals.