As oil prices increase and energy security becomes a concern in the US, more is being done to explore cleaner burning fuels such as natural gas. Natural gas has seen big increases in the number of wells and total production as shale gas extraction, in particular, intensifies. The EPA projects that 20% of US gas supply will come from shale gas by 2020.
An EPA report in 2004 found that "there was little to no risk of fracturing fluid contaminating underground sources of drinking water during hydraulic fracturing of coalbed methane production wells." But public concern over the process by which shale gas is extracted known as hydraulic fracturing, or "fracking," has escalated with the growing number of wells. Each well requires the pumping of tremendous amounts of fracking fluid into the earth and, according to the EPA's 2004 report, "[t]here is very little documented research on the environmental impacts that result from the injection and migration of these fluids into subsurface formations, soils, and USDWs." Until last year (when the EPA called for the voluntary reporting of chemicals used in fracking fluids), many of the chemicals used in fracking were unknown. Chemicals now known to sometimes be involved in the process include: diesel fuel (which contains benzene and other toxic chemicals), polycyclic aromatic hydrocarbons, methanol, formaldehyde, ethylene glycol, hydrochloric acid, and sodium hydroxide. Given this situation, the EPA has announced another study to examine the effects of hydraulic fracturing on drinking water and groundwater. The EPA aims to issue preliminary findings in 2012 and a full report in 2014. The draft study plan is available at here.