0:00:08.516,0:00:14.455
Deep underground lies stores of once[br]inaccessible natural gas.

0:00:14.455,0:00:17.605
This gas was likely formed [br]over millions of years

0:00:17.605,0:00:22.966
as layers of decaying organisms[br]were exposed to intense heat and pressure

0:00:22.966,0:00:25.645
under the Earth's crust.

0:00:25.645,0:00:28.355
There's a technology called[br]hydraulic fracturing,

0:00:28.355,0:00:29.764
or fracking,

0:00:29.764,0:00:32.467
that can extract this natural gas,

0:00:32.467,0:00:36.398
potentially powering us[br]for decades to come.

0:00:36.398,0:00:38.148
So how does fracking work,

0:00:38.148,0:00:42.288
and why it is a source [br]of such heated controversy?

0:00:42.288,0:00:45.557
A fracking site can be anywhere[br]with natural gas,

0:00:45.557,0:00:46.837
from a remote desert

0:00:46.837,0:00:50.236
to several hundred feet[br]from your backyard.

0:00:50.236,0:00:54.548
It starts out with a long vertical hole[br]known as a wellbore

0:00:54.548,0:00:57.927
drilled down through layers of sediment.

0:00:57.927,0:01:03.428
When the well reaches 2500 - 3000 meters,[br]it's at its kickoff point

0:01:03.428,0:01:07.430
where it can begin the process[br]of horizontal drilling.

0:01:07.430,0:01:13.523
It turns 90 degrees and extends[br]horizontally for about 1.5 kilometers

0:01:13.523,0:01:18.969
through a compressed black layer[br]called the shale rock formation.

0:01:18.969,0:01:23.159
A specialized perforating gun[br]is then lowered and fired,

0:01:23.159,0:01:25.990
creating a series of small, [br]inch-long holes

0:01:25.990,0:01:30.720
that burst through the well's casing[br]into the rock layer.

0:01:30.720,0:01:33.668
About three to four months[br]after the initial drilling,

0:01:33.668,0:01:37.112
the well is ready for fracking to begin.

0:01:37.112,0:01:41.128
Fracking fluid is pumped down[br]into the well at a pressure so high,

0:01:41.128,0:01:43.390
it cracks the shale rock,

0:01:43.390,0:01:48.526
creating fractures through which[br]the trapped gas and oil can escape.

0:01:48.526,0:01:52.052
The fluid itself is more than 90% water.

0:01:52.052,0:01:55.680
The rest is made up of concentrated[br]chemical additives.

0:01:55.680,0:02:00.000
These vary depending on the specific[br]characteristics of the fracking site,

0:02:00.000,0:02:02.902
but usually fall into three categories:

0:02:02.902,0:02:06.432
acids for clearing debris[br]and dissolving minerals,

0:02:06.432,0:02:08.561
friction-reducing compounds to create

0:02:08.561,0:02:12.462
a slippery form of water [br]known as slickwater,

0:02:12.462,0:02:15.813
and disinfectant to prevent[br]bacteria growth.

0:02:15.813,0:02:20.694
Sand or clay is also mixed into[br]the water to prop open the fissures

0:02:20.694,0:02:26.918
so the gas and oil can keep leaking out,[br]even after the pressure is released.

0:02:26.918,0:02:30.444
It's estimated that all of fracking's[br]intense pumping and flushing

0:02:30.444,0:02:35.993
uses an average of 3-6 million gallons[br]of water per well.

0:02:35.993,0:02:38.953
That's actually not a lot compared[br]to agriculture,

0:02:38.953,0:02:40.073
power plants,

0:02:40.073,0:02:42.673
or even golf course maintenance,

0:02:42.673,0:02:47.092
but it can have a notable impact[br]on local water supply.

0:02:47.092,0:02:50.805
And disposing of used fracking water[br]is also an issue.

0:02:50.805,0:02:53.574
Along with the trapped gas[br]that's pumped up to the surface,

0:02:53.574,0:02:58.934
millions of gallons of flow-back liquid[br]come gushing up.

0:02:58.934,0:03:02.264
This liquid containing contaminants[br]like radioactive material,

0:03:02.264,0:03:03.235
salts,

0:03:03.235,0:03:04.134
heavy metals,

0:03:04.134,0:03:05.604
and hydrocarbons,

0:03:05.604,0:03:08.335
needs to be stored and disposed of.

0:03:08.335,0:03:11.974
That's usually done in pits on-site[br]in deep wells

0:03:11.974,0:03:15.765
or off-site at water treatment facilities.

0:03:15.765,0:03:19.045
Another option is to recycle[br]the flow-back liquid,

0:03:19.045,0:03:23.456
but the recycling process can actually[br]increase levels of contamination

0:03:23.456,0:03:27.135
since the water is more toxic[br]with each use.

0:03:27.135,0:03:30.273
Wells are typically encased [br]in steel and cement

0:03:30.273,0:03:33.366
to prevent contaminants from leaking[br]into groundwater.

0:03:33.366,0:03:36.507
But any negligence [br]or fracking-related accidents

0:03:36.507,0:03:38.925
can have devastating effects.

0:03:38.925,0:03:41.377
Fracturing directly [br]into underground water

0:03:41.377,0:03:43.996
hazardous underground [br]seepage and leakage,

0:03:43.996,0:03:48.307
and inadequate treatment and disposal[br]of highly-toxic waste water

0:03:48.307,0:03:52.517
can potentially contaminate[br]drinking water around a fracking site.

0:03:52.517,0:03:55.520
There's also concern about[br]the threat of earthquakes

0:03:55.520,0:03:57.169
and damaged infrastructure

0:03:57.169,0:04:00.287
from pressure [br]and waste water injection.

0:04:00.287,0:04:03.628
Links between fracking[br]and increased seismic activity

0:04:03.628,0:04:08.017
leave unresolved questions[br]about long-term pressure imbalances

0:04:08.017,0:04:11.438
that might be happening[br]deep beneath our feet.

0:04:11.438,0:04:15.128
Fracking's biggest controversy, though,[br]is happening above the ground.

0:04:15.128,0:04:19.908
The general consensus is that burning[br]natural gas is better for the environment

0:04:19.908,0:04:21.639
than burning coal

0:04:21.639,0:04:23.411
since the gas collected from fracking

0:04:23.411,0:04:26.670
emits only half [br]the carbon dioxide as coal

0:04:26.670,0:04:28.960
per unit of energy.

0:04:28.960,0:04:31.449
The pollution caused [br]by the fracking itself, though,

0:04:31.449,0:04:33.079
isn't negligible.

0:04:33.079,0:04:36.010
Methane that leaks out during the drilling[br]and pumping process

0:04:36.010,0:04:39.159
is many times more potent[br]than carbon dioxide

0:04:39.159,0:04:41.459
as a greenhouse gas.

0:04:41.459,0:04:44.781
Some scientists argue that methane[br]eventually dissipates,

0:04:44.781,0:04:48.681
so has a relatively low long-term impact.

0:04:48.681,0:04:51.280
But a greater question hangs in the air.

0:04:51.280,0:04:53.989
Does fracking take time,[br]money, and research

0:04:53.989,0:04:58.960
away from the development[br]of cleaner renewable energy sources?

0:04:58.960,0:05:00.771
Natural gas is non-renewable,

0:05:00.771,0:05:04.170
and the short-run economic interests[br]supporting fracking

0:05:04.170,0:05:07.879
may fall short in the face[br]of global climate change.

0:05:07.879,0:05:11.802
Experts are still examining[br]fracking's overarching effects.

0:05:11.802,0:05:15.281
Although modern fracking has been[br]around since the 1940s,

0:05:15.281,0:05:17.722
it's boomed in the last few decades.

0:05:17.722,0:05:22.690
As other sources of natural gas decrease,[br]the costs of non-renewable energies rise,

0:05:22.690,0:05:26.653
and cutting-edge technologies[br]make it so accessible.

0:05:26.653,0:05:29.723
But many countries and regions[br]have already banned fracking

0:05:29.723,0:05:32.573
in response to environmental concerns.

0:05:32.573,0:05:37.183
It's undeniable that fracking has reshaped[br]the energy landscape around the world,

0:05:37.183,0:05:41.122
but for what long-term benefit[br]and at what cost?