(Bloomberg) — Hydraulic fracturing has contaminated some
drinking water sources but the damage is not widespread,
according to a landmark U.S. study of water pollution risks that
has supporters of the drilling method declaring victory and foes
saying it revealed reason for concern.
The draft analysis by the Environmental Protection Agency,
released Thursday after three years of study, looked at possible
ways fracking could contaminate drinking water, from spills of
fracking fluids to wastewater disposal.
“We conclude there are above and below ground mechanisms
by which hydraulic fracturing activities have the potential to
impact drinking water resources,” the EPA said in the report.
But, “we did not find evidence that these mechanisms have led
to widespread, systemic impacts on drinking water resources.”
The study was commissioned by Congress and represents the
most comprehensive assessment yet of the safety of fracking, a
technique that has led to a boom in domestic oil and gas
production but also spawned persistent complaints about
pollution. Fracking involves the injection of water, sand and
chemicals underground to break apart shale rock and free trapped
oil or gas.
Thomas Burke, the EPA’s top science adviser, told reporters
that given thousands of wells drilled and fracked in the last
few years, “the number of documented impacts on groundwater
resources is relatively low.”
Still, it’s not accurate to say that there have been no
cases of contamination, he said.
“There are instances where the fracking activity itself”
led to water pollution, he said.
The EPA looked at the potential for spills of fracking
fluids, poor wastewater disposal or migration of chemicals shot
The American Petroleum Institute, an industry trade group,
said the study was a validation of the safety of fracking. It
said it showed existing oversight from state regulators is
“Hydraulic fracturing is being done safely under the
strong environmental stewardship of state regulators and
industry best practices,” Erik Milito, API’s upstream group
director, said in an e-mail.
When the study began much of the focus was on the risk that
chemicals mixed in fracking fluids could flow through
underground fissures and into underground water reservoirs. The
study results show that might not be the biggest risk.
“The process of fracking itself is one risk factor. But in
fact it’s not the biggest one,” said Mark Brownstein, vice
president of the Environmental Defense Fund. “Ongoing physical
integrity of the wells and handling the millions of gallons of
wastewater coming back to the surface after fracking, over the
lifetime of each well, are even bigger challenges.”
Amy Mall, a senior policy analyst for the Natural Resources
Defense Council, said the study provides “solid science that
fracking has contaminated drinking water across the country.”
Mall said, however, that a lack of cooperation from
industry meant EPA lacked key data necessary to fully assess its
Another environmental group, Earthworks, said EPA analysis
points to the need for regulation.
“Now the Obama administration, Congress, and state
governments must act on that information to protect our drinking
water, and stop perpetuating the oil and gas industry’s myth
that fracking is safe,” said Lauren Pagel, Earthwork’s policy
director, in an e-mail.
The EPA said it analyzed more than 950 sources of
information. The study included an analysis of industry-backed
disclosures of the chemicals used in fracking, case-studies of
local communities where homeowners feared their water wells were
contaminated and a review of well construction.
The EPA said as many as 30,000 fracked wells were drilled
annually between 2011 to 2014, as oil production reached its
highest level in more than three decades.
“People in favor of drilling will see this as
vindication,” said Rob Jackson, a Stanford University professor
who has tested drinking water near fracking sites in Texas,
Pennsylvania and other states. “People opposed to it will see
this as a whitewash.”
To contact the reporters on this story:
Mark Drajem in Washington at
Jim Snyder in Washington at
To contact the editors responsible for this story:
Jon Morgan at