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Fracking’s impacts on water extend far beyond polluted wells, expert says

The rate of earthquakes above magnitude 3 in the midcontinental U.S. has been rising steadily from 21 events a year, on average, with a steep acceleration after 2010 and a peak of 188 events in 2011.
Robert Jackson

Like a lot of people, perhaps, I was drawn to Rob Jackson’s talk on hydrofracking’s water impacts with visions of those flaming kitchen taps out east.

But the risk to drinking-water wells was only a small part of the troubled landscape surveyed by Jackson, an environmental scientist at Duke and Stanford universities whose background includes degrees in ecology, statistics and chemical engineering.

And though the troubles lie beyond Minnesota’s borders, the Freshwater Society’s concern extends to water problems everywhere — and so, perhaps, should ours.

Some key points from his wide-ranging, fair-minded and highly accessible talk, which was organized by the Freshwater Society and delivered Thursday evening on the University of Minnesota’s St. Paul campus:

Apart from impacts on water quality, fracking is a water-intensive process with potential impacts on water quantity. Considering the energy returned, fracking to produce natural gas uses less water on a unit basis than extracting oil from tar sands, or making electricity from biomass, he said.

But, still, each natural-gas well opened with a combination of horizontal drilling and injection of hydraulic fluids requires water on the order of 1 to 7 million gallons per well, depending on the geology. And only one-third of that water, on average, is ever returned to the surface.

Even in a water-rich state like Pennsylvania, which gets 35 inches of precipitation a year in the area where fracking is producing gas from the Marcellus shale formation, this much pumping of groundwater can create local drawdowns with an appreciable impact on streams and lakes, as well as groundwater supplies. 

Around the Eagle Ford fields in east Texas, he said, where annual precipitation is only about 20 inches, the pumping has the potential to draw down aquifers by “feet to tens of feet.”

What the water carries up

Considering what’s in the water that comes back up, though, the low return rate may often be good news.

This “produced water” is being returned at the rate of about 2 billion gallons a day, or roughly a trillion gallons a year, “so the No. 1 thing that oil and gas wells produce isn’t oil and gas — it’s salty, briny water.”

How salty? From the Marcellus wells, typically 10 times saltier than seawater.

Among the other contaminants: toxic elements like barium, selenium, arsenic and lead; bromides, which can interact with methane to produce carcinogenic compounds; elevated levels of natural radioactivity, from naturally occurring but now concentrated substances.

Not to mention the residues of fracking fluids, oil and fuels. Those tend to come back first in a rush after injection ends, Jackson said, to be followed by a longer stream of “nasty, briny wastewater.”

Some 95 percent of this produced water is injected back underground for disposal, which means it’s off our hands. But it’s also out of our supply of available groundwater, essentially forever, and as we all may remember from grade-school earth science, the planet’s water supply is finite.

The 5 percent remaining aboveground becomes an interesting set of disposal problems. Seven states allow the water to be sprayed on land, untreated, or on roads as a de-icing compound, with varying results, many of them undesirable.

In one West Virginia test, he said, some 75,000 gallons of produced water was sprayed on a wooded patch of land to see what would happen; half the trees were dead in a few years.

In the cattle-grazing areas of the arid West, he said, the water is considered by law to have a “beneficial use” if sprayed onto land to create streams that help water the herds.

“These things are just — just dumb,” he said, but alternatives can be tough to arrange. Pennsylvania used to send a lot of produced water through conventional municipal treatment plants, but they weren’t set up to handle the volumes, the chemicals or the radioactivity.

So a new industry has grown up around private water treatment and disposal, using distillation, reverse osmosis and other methods.

Creating radioactive sediments

At one Pennsylvania operation studied by Jackson and colleagues over a period of years, discharges met state and federal standards for certain metals and regulators concluded that “the plant was doing its job.” But levels of salts and radiation remained high.

Though the concentrations of radioactive particles met sampling standards at the discharge pipe, the sheer volume of water moving out of the plant brought river sediments downstream to radiation levels “high enough to where you would have to take them for disposal at a radioactive waste site — you couldn’t dispose of them at a landfill.”

After Jackson’s team published their results, the company supplying the wastewater to the plant announced it would dredge the streambed and haul the sediments away.

On the flip side, Jackson cited several positive developments in terms of fracking’s water impacts, starting with a move toward re-use and recycling of returned water by hauling it from one set of wells to another for re-injection.

On public-health disclosure of fracking chemicals, Jackson said that even though “there’s very often a narrative that the companies don’t disclose the chemicals they use, that’s not true.”

New rules in Wyoming, Texas and elsewhere have brought more transparency, which in turn may lead to a faster phase-out of the worst materials. However, about 20 percent of the chemicals remain hidden behind trade-secret exceptions in the disclosure rules.

Closing up the pits

Meanwhile, there is significant movement away from what used to be the wastewater-disposal method of choice in many areas: retention of returned water in open pits, which invites the problems of failed liners and other leaks that are familiar to Minnesotans who live near certain landfills and feedlot operations. Many of these pits are being converted to enclosed-tank operations or eliminated entirely, he said.

While cautioning that he is not a seismologist, Jackson addressed a subject that has been intermittently high in the headlines for a couple of years now: “induced seismicity,” or the notion that the pressures and volumes of fluids injected in fracking can cause earthquakes.

Based on his reading and conversations with scientists investigating this possibility, he said, “well, literally it’s true — a hydraulic fracture is a tiny, tiny tremor,” an earthquake too small to feel or to be dangerous.

The biggest quakes ever associated with fracking in this country, he said, have been of a magnitude less than 4, “but that’s not where the action is, and that’s not what people should be worrying about.”

Ellsworth 2013, Science
Earthquakes with magnitude 3 or greater in the U.S.
midcontinent, 1967–2012.

“In rare cases, but much more commonly,” he said, it’s re-injection of wastewater that causes seismic activity, because of the sheer volume of material being injected at great depth. (And the problems this causes would happen with any material — say, carbon dioxide being injected for long-term storage.)

According to a study published last year in the journal Science, Jackson said, the rate of earthquakes above magnitude 3 in the midcontinental U.S. has been rising steadily from 21 events a year, on average, with a steep acceleration after 2010 and a peak of 188 events in 2011.

The most powerful event that some scientists think can be attributed to injection approached magnitude 5.6 or 5.7, he said, which is moving into a range that can be dangerous.

In response, the U.S. Geological Survey is working with the industry to come up with protocols for monitoring seismicity and backing off on injection if the earth starts to tremble. Which I guess should qualify as good news, too.

* * *

Jackson’s talk, sponsored by university’s College of Biological Sciences along with the Freshwater Society, can be viewed right here, along with his excellent slides.

Join MinnPost for a substantive discussion of environmental risks and regulatory challenges presented by proposals to mine and process metals from sulfide ores. Monday, Feb. 10, 5:30 p.m. Click here for details and tickets.

Comments (5)

  1. Submitted by Robert Moffitt on 02/04/2014 - 12:56 pm.

    It should be noted…

    …that Minnesota has no natural gas or petroleum reserves to use this drilling technique on. The vast majority of our petroleum comes from the Tar Sands region of Canada.

  2. Submitted by James Hamilton on 02/04/2014 - 01:34 pm.


    the presentation. It will take about an hour for the presentation and another 30 minutes if you play the Q&A. You’ll find it far more informative and, perhaps, more balanced than Mr. Meador’s synopsis. I did.

  3. Submitted by David Frenkel on 02/04/2014 - 02:55 pm.


    It is the job of the USGS to track earthquakes. There has always been plenty of seismic activity in the US but it is virtually impossible to prove what causes the activity outside of tectonic plate movements. I would leave the study of earthquakes to geologists and the USGS.

    • Submitted by Neal Rovick on 02/05/2014 - 03:08 pm.

      (quote)Recent earthquakes in


      Recent earthquakes in Ohio and Oklahoma have been directly linked to deep wells used to dispose of liquid wastes for hydraulic fracturing or “fracking” of natural gas, according to geological experts.
      And they expect more earthquakes to come as the industry continues to expand across the eastern United States.

      (end quote)


      The decision by the state to hire a seismologist comes amidst growing concerns that natural gas fracking caused several dozen recent earthquakes near Dallas-Ft. Worth.
      University of Texas researcher Dr. Cliff Frohlich is the state’s foremost expert on earthquakes related to natural gas fracking.
      Dr. Frohlick says seismologists have known since the 1960s that the disposal of so-called “frack fluids” – primarily water – can cause earthquakes. But until recently, most of those quakes have been in areas where no one lives.
      Before fracking moved in, earthquakes were nearly unheard of in the Dallas-Fort Worth area.
      “When you locate the earthquakes, you look around and say what’s nearby,” Frohlich said. “And I’ve had papers showing that these earthquakes are close to injection wells.”
      Dr. Frohlich says that instead of injecting the water into the ground after the fracking process, companies could treat the water, as is done with sewage. However, that is a much more expensive process.

      (end quote)


      The bad news in Tulsa is that since fracking began, the state has experienced a rise in seismic events. In a report entitled “Earthquake Swarm Continues in Central Oklahoma,” released on 22 October in partnership with the Oklahoma Geological Survey, the U.S. Geological Survey noted, “Since January 2009, more than 200 magnitude 3.0 or greater earthquakes have rattled Central Oklahoma, marking a significant rise in the frequency of these seismic events… Studies show one to three magnitude 3.0 earthquakes or larger occurred yearly from 1975 to 2008, while the average grew to around 40 earthquakes per year from 2009 to mid-2013. ‘We’ve statistically analyzed the recent earthquake rate changes and found that they do not seem to be due to typical, random fluctuations in natural seismicity rates. Bill Leith, USGS seismologist noted, ‘These results suggest that significant changes in both the background rate of events and earthquake triggering properties needed to have occurred in order to explain the increases in seismicity. This is in contrast to what is typically observed when modeling natural earthquake swarms.’”

      (end quote)

  4. Submitted by Neal Rovick on 02/04/2014 - 04:39 pm.

    (quote)In September, Steve


    In September, Steve Slawson, vice president for Slawson Exploration, sat in a trailer about 35 miles north of Oklahoma City, watching monitors as his crew shattered the Mississippi lime thousands of feet below. The well, known as Begonia 1-30H, will cost about $3.7 million. One-third of that is the cost of fracking: First, thin pipes loaded with explosives are threaded into the hole to blast the ancient reef. Then, at a cost of about $80,000, the Begonia will consume 50,000 gallons of hydrochloric acid to dissolve the limestone; another $68,000 will pay for 1,000 gallons of antibacterial solution to kill microorganisms that chew up the pipes; $110,000 goes for a soapy surfactant to reduce friction; $10,000 covers a scale inhibitor to prevent lime buildup; and $230,000 purchases 2 million pounds of sand to prop the fractures open so the oil and gas can flow into the well. Then there’s $300,000 in pumping charges, plus the cost of equipment rental, pipe, and water, which brings the price tag for fracking the well to $1.2 million. A host of other things, from cement to Porta Potty rentals, accounts for the rest of the cost.

    There’s little doubt Begonia will produce oil, Slawson says. The question is whether it will be enough to cover the cost of drilling and how quickly. Slawson Exploration’s first Mississippi lime horizontal well, the nearby Wolf 1-29H, produced the equivalent of almost 1,185 barrels a day when it started flowing last year and has paid for itself twice over, Slawson says. After the Wolf, a third of his wells were “dogs,” and only a third have come even close to it.

    (end quote)

    That’s a lot of foreign substances to inject into the ground.

    10 years from Bakken will have been used up, but the chemicals remain.


    When oil is produced, brine or produced water rich in salts and toxic metals also comes out of the ground. The oil companies injected the wastes back underground to a depth of between 800 and 1,000 feet, where it was assumed the material would stay put. It did not.

    In 2004, Bruce Smith, a geophysicist at USGS, flew a helicopter over a 100-square-mile area on the reservation. Dangling from his ride was a magnetic beam that could detect the presence of salty water below ground.

    “It is kind of like a CAT scan of the Earth of very small areas as we fly over,” Smith said.

    Smith found two potential plumes covering 12 square miles that seemed to be migrating closer to Poplar’s water supply.

    The scientists drilled 40 boreholes, tested the water on the reservation and found it was significantly contaminated. In 2010, they tested three public wells Poplar draws its water from and found that all were contaminated with brine. The pollution was due to a well casing failure of an injection well, Smith said.

    Meanwhile, farther north in North Dakota, the Bakken boom was continuing apace and the USGS directed its efforts there. Smith and his colleagues found at least 292,745 wetlands and 4,440 miles of streams were within a mile of an oil or gas well. Spills of oil and produced water were common in the state, which reported 1,129 incidents in 2012 (EnergyWire, July 8). A snowy winter in 2011 caused several waste pits containing brine to overflow in the spring.

    These spills are noted in official databases, but the extent of brine contamination in the subsurface is unknown. Once a spill happens, there is some remediation of the soils, but the movement of brine below ground is not tracked.

    (end quote)

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