Gas drilling companies will try
to convince you that using up to 6-million gallons of
water for fracing one gas well doesn't amount to a
massive amount of water. Even if they are successful in
making that argument with you, the next topic becomes flowback or brine.
What do you do with the crap that
comes back out of the ground?
The Municipal Authority of McKeesport accepts 80,000 gallons
per day, which is then mixed with treated sewage and dumped into the
Monongahela River upstream from Pittsburgh. Hawg Hauling is part of
Chesapeake Energy.
Somewhere between 30% and 70% of
the water used for hydro-fracing a gas well returns to
the surface as flowback. In addition to the frac fluids
added by the gas drilling companies, this water picks up other
contaminants from deep in the Earth (~ 7,000 feet deep) with
one of the most notable being salt.
These fluids contain sodium and calcium salts, barium, oil,
strontium, iron, numerous heavy metals, soap, radiation and other
components. This fluid combination becomes brine wastewater, and tanker
trucks hauling it are labeled with a RESIDUAL WASTE
placard. Treated brine is also sold for deicing and
other applications that utilize calcium chloride, often being
applied to roadways.
Brine wastewater is difficult and
expensive to treat, one of the same reasons we aren't
using much ocean water for agriculture and residential
applications. The saltiness of this wastewater creates a
high level of TDS (total dissoved solids). Incomplete
processing of this brine wastewater, especially when
dumped into rivers used for drinking water, creates a
high TDS situation that causes drinking water treatment
plants problems, like Trihalomehtanes. High TDS water
reacts with chlorine when it is processed.
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The
gas industry estimates the amount of high-TDS wastewater
needing disposal in Pennsylvania will increase from 9
million gallons per day in 2009 to 20 million gallons
per day by 2011 |
In other parts of the United
States, gas drilling operations dispose of their
wastewater deep in the ground, by using deep injection
wells. However, the geology around Marcellus Shale
doesn't lend itself as well to accepting deep
injections, so the wastewater gets dumped back into
Pennsylvania watersheds. Early on in Marcellus drilling,
many municipal treatment plants were accepting this
briny wastewater that weren't equipped to process it.
Add that situation to low river levels due to drought
and you begin to have real problems.
Of course even if the wastewater
is processed by an industrial level processing plant, we
are left with serious questions about the frac fluids
that remain in processed drinking water. Drilling
companies argue that frac fluids make up a very small
percentage of hydro-fracing, but even using their
numbers frac fluids make up 1,500 gallons of a 3-million
gallon well fracking. Let's not forget that many wells
are fraced 10-times or more during the life of the well,
to stimulate further gas exploitation.
In order to get a look at gas
drilling wastewater treatment, this page provides a list
of wastewater treatment facilities in various regions of
Pennsylvania, as of July 2009. Some 20 permits for
processing brine flowback in Pennsylvania are in the
approval process.
As Marcellus Shale gas drilling
and fracking activites increase in the coming years,
clean drinking water will become a much more critical
issue for Pennsylvania and other states on the Marcellus
Shale formation.
Bottoms up!
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