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| A class 2 brine disposal well in western Louisiana near the Texas border. The
well sat by the side of the road, without restricted access. (Abrahm
Lustgarten/ProPublica)
Over the past several decades, U.S. industries have injected more than 30
trillion gallons of toxic liquid deep into the earth, using broad expanses of
the nation's geology as an invisible dumping ground.
No company would be allowed to pour such dangerous chemicals into the rivers
or onto the soil. But until recently, scientists and environmental officials
have assumed that deep layers of rock beneath the earth would safely entomb the
waste for millennia.
There are growing signs they were mistaken.
Records from disparate corners of the United States show that wells drilled
to bury this waste deep beneath the ground have repeatedly leaked, sending
dangerous chemicals and waste gurgling to the surface or, on occasion, seeping
into shallow aquifers that store a significant portion of the nation's drinking
water.
In 2010, contaminants from such a well bubbled up in a west Los Angeles dog
park. Within the past three years, similar fountains of oil and gas drilling
waste have appeared in Oklahoma and Louisiana. In South Florida, 20 of the
nation's most stringently regulated disposal wells failed in the early 1990s,
releasing partly treated sewage into aquifers that may one day be needed to
supply Miami's drinking water.
There are more than 680,000 underground waste and
injection [1] wells nationwide, more than
150,000 of which shoot industrial fluids thousands of feet below the surface.
Scientists and federal regulators acknowledge they do not know how many of the
sites are leaking.
Federal officials and many geologists insist that the risks posed by all this
dumping are minimal. Accidents are uncommon, they say, and groundwater reserves
— from which most Americans get their drinking water — remain safe and far
exceed any plausible threat posed by injecting toxic chemicals into the
ground.
But in interviews, several key experts acknowledged that the idea that
injection is safe rests on science that has not kept pace with reality, and on
oversight that doesn't always work.
"In 10 to 100 years we are going to find out that most of our groundwater is
polluted," said Mario Salazar, an engineer who worked for 25 years as a
technical expert with the EPA's underground injection program in Washington. "A
lot of people are going to get sick, and a lot of people may die."
The boom in oil and natural gas drilling is deepening the uncertainties,
geologists acknowledge. Drilling produces copious amounts of waste, burdening
regulators and demanding hundreds of additional disposal wells. Those wells —
more holes punched in the ground — are changing the earth's geology, adding
man-made fractures that allow water and waste to flow more freely.
"There is no certainty at all in any of this, and whoever tells you the
opposite is not telling you the truth," said Stefan Finsterle, a leading
hydrogeologist at Lawrence Berkeley National Laboratory who specializes in
understanding the properties of rock layers and modeling how fluid flows through
them. "You have changed the system with pressure and temperature and fracturing,
so you don't know how it will behave."
A ProPublica review of well records, case histories and government summaries
of more than 220,000 well inspections found that structural failures inside
injection wells are routine. From late 2007 to late 2010, one well integrity
violation was issued for every six deep injection wells examined — more than
17,000 violations nationally. More than 7,000 wells showed signs that their
walls were leaking. Records also show wells are frequently operated in violation
of safety regulations and under conditions that greatly increase the risk of
fluid leakage and the threat of water contamination.
Structurally, a disposal well is the same as an oil or gas
well. [2] Tubes of concrete and steel extend
anywhere from a few hundred feet to two miles into the earth. At the bottom, the
well opens into a natural rock formation. There is no container. Waste simply
seeps out, filling tiny spaces left between the grains in the rock like the gaps
between stacked marbles.
Many scientists and regulators say the alternatives to the injection process
— burning waste, treating wastewater, recycling, or disposing of waste on the
surface — are far more expensive or bring additional environmental risks.
Subterranean waste disposal, they point out, is a cornerstone of the nation's
economy, relied on by the pharmaceutical, agricultural and chemical industries.
It's also critical to a future less dependent on foreign oil: Hydraulic
fracturing, "clean coal" technologies, nuclear fuel production and carbon
storage (the keystone of the strategy to address climate change) all count on
pushing waste into rock formations below the earth's surface.
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