Natural Gas Drilling Poses Threat to Region's Groundwater
Charleston Gazette
2 February 2010
Beginning to unlock staggering quantities of natural gas underneath
Appalachia also yields a troubling byproduct: powerfully briny
wastewater that can kill fish and give tap water a foul taste andodor.
With fortunes, water quality and cheap energy hanging in the balance,
exploration companies, scientists and entrepreneurs are scrambling for
an economical way to recycle the wastewater.
"Everybody and his brother is trying to come up with the 11 herbs and
spices," said Nicholas DeMarco, executive director of the West Virginia
Oil and Natural Gas Association.
Drilling crews across the country have been flocking since late 2008 to
the Marcellus Shale, a rock bed the size of Greece that lies about
6,000 feet beneath New York, Pennsylvania, West Virginia and Ohio.
Geologists say it could become the most productive natural gas field in
the U.S., capable of supplying the entire country's needs for up to two
decades by some estimates.
Before that can happen, the industry is realizing that it must solve
the challenge of what to do with its wastewater. As a result, the
Marcellus Shale in on its way to being the nation's first gas field
where drilling water is widely reused.
The polluted water comes from a drilling technique known as hydraulic
fracturing, or "fracking," in which millions of gallons of water, sand
and chemicals are blasted into each well to fracture tightly compacted
shale and release trapped natural gas.
Fracking has been around for decades. But the drilling companies are
now using it in conjunction with a new horizontal drilling technique
they brought to Appalachia after it was proven in the 1990s to be
effective on a shale formation beneath Texas.
Fracking a horizontal well costs more money and uses more water, but it
produces more natural gas from shale than a traditional vertical well.
Once the rock is fractured, some of the water -- estimates range from
15 to 40 percent -- comes back up the well. When it does, it can be
five times saltier than seawater and laden with dissolved solids such
as sulfates and chlorides, which conventional sewage and drinking water
treatment plants aren't equipped to remove.
At first, many drilling companies hauled away the wastewater in tanker
trucks to sewage treatment plants that processed the water and
discharged it into rivers -- the same rivers from which water utilities
then drew drinking water.
But in October 2008, something happened that stunned environmental
regulators: The levels of dissolved solids spiked above government
standards in southwestern Pennsylvania's Monongahela River, a source of
drinking water for more than 700,000 people.
Regulators said the brine posed no serious threat to human health. But
the area's tap water carried an unpleasant gritty or earthy taste and
smell and left a white film on dishes. And industrial users noticed
corrosive deposits on valuable machinery.
One 11-year-old suburban Pittsburgh boy with an allergy to sulfates,
Jay Miller, developed hives that itched for two weeks until his mother
learned about the Monongahela's pollution and switched him to bottled
or filtered water.
No harm to aquatic life was reported, though high levels of salts and
other minerals can kill fish and other creatures, regulators say.
Pennsylvania officials immediately ordered five sewage treatment plants
on the Monongahela or its tributaries to sharply limit the amount of
frack water they accepted to 1 percent of their daily flow.
"It is a very great risk that what happened on the Monongahela could
happen in many watersheds," said Ronald Furlan, a wastewater treatment
official for the Pennsylvania Department of Environmental Protection.
"And so that's why we're trying to pre-empt and get ahead of it to
ensure it doesn't happen again."
Regulators in Pennsylvania are trying to push through a new standard
for the level of dissolved solids in water released from a treatment
plant.
West Virginia authorities, meanwhile, have asked sewage treatment
plants not to accept frack water while the state develops an approach
to regulating dissolved solids.
And in New York, fracking is largely on hold while companies await a
new set of state permitting guidelines.
For now, the Marcellus Shale exploration is in its infancy. Terry
Engelder, a geoscientist at Penn State University, estimates the
reserve could yield as much as 489 trillion cubic feet of gas. To date,
the industry's production from Pennsylvania, where drilling is most
active, is approaching 100 billion cubic feet.
Wastewater from drilling has not threatened plans to develop the
nation's other gas reserves. Brine is injected into deep underground
wells in places such as Louisiana, Texas and Oklahoma, or left in
evaporation ponds in arid states such as Colorado and Wyoming.
However, many doubt the hard Appalachian geology is porous enough to
absorb all the wastewater, and the climate is too humid for evaporating
ponds. That leaves recycling as the most obvious option.
Entrepreneurs are marketing portable systems that distill frack water
at the well site.
Also, in southwestern Pennsylvania, Range Resources Corp., one of the
gas field's most active operators, pipes wastewater into a central
holding pond, dilutes it with fresh water and reuses it for fracking.
Range says the practice saves about $200,000 per well, or about 5
percent.
In addition, a $15 million treatment plant that distills frack water is
opening in Fairmont, W.Va. The 200,000 gallons it can treat each day
can then be trucked back for use at a new drilling site.
For years, regulators let sewage treatment plants take mining and
drilling wastewater under the assumption that rivers would safely
dilute. But fracking a horizontal well requires huge amounts of water
-- up to 5 million gallons per well, compared with 50,000 gallons in
some conventional wells.
"In this case," said John Keeling of MSES Consultants, which designed
the Fairmont plant, "dilution is not the solution to pollution."