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."