Is Fracking Safe?

It May Depend on What You Mean By "Fracking"

A new study by Thomas Darrah of Duke University and four colleagues, published in the Proceedings of the National Academcy of Sciences, suggests that there has been significant contamination of the ground water from natural gas drilling in Pennsylvania and Texas, but this contamination is not due to the process of hydraulic fracturing itself. Rather it is caused by leakage of methane, the primary ingredient in natural gas, and other chemicals near the surface due to faulty construction of the well.

The researchers took 133 water samples from drinking water wells—113 of them from along the Marcellus Shale in Pennsylvania and 20 from the Barnett Shale in Texas. Through chemical analysis, they were able to tell whether each sample was contaminated, and if so, from where the contimation had come. I'm not knowledgeable enough in chemistry to understand the testing that was done, so I rely on the fact that this was a peer-reviewed journal.

They found eight clusters of contaminated wells—seven in Pennsylvania and one in Texas. The cluster in Texas consisted of five of the twenty samples they took. They don't say how many samples were included in the seven Pennsylvania clusters. From eyeballing their charts, it looks like about 20-25% of their samples were contaminated. However, the wells were not randomly selected. The researchers had focused on areas where contamination was suspected.

The chemical analysis indicated that four of the eight clusters were due to leakage around the cement used to seal the outside of the well, three were due corroded or poorly joined steel tubing used to drill into the ground, and the last was due to “underground mechanical well failure.”

Diagram by Howarth and Engelder (2011)

In hydraulic fracturing, or fracking, fracking fluid is forced into the shale at high pressure in order to release the natural gas contained in it. The concern is that fracking might create breaks in the undreground rock formations, through which either natural gas or fracking fluid might leak upward and contaminate drinking water. None of the contamination came from far enough below the surface to indicate that this type of contamination had occurred.

Unlike last week's study of the correlation between fracking sites and health problems, this study received generous coverage by the corporate media. The general spin seemed to be that “fracking is safe.” The Pittsburgh Post-Gazette ran a McClatchy article about the study on the front page. Two days later, they reprinted a Bloomsberg op-ed entitled “Fracking is not the threat.” The threat, it seems, is drilling company carelessness, which can be avoided through government regulations, regular inspections, and fines for poor performance.

The coverage is superficial in at least two respects. First, while there is no evidence that fracking in the narrow sense--that is, hydraulic fracturing, per se--has caused contamination, fracking in a broader sense--the fracking boom--is certainly responsible for ground water contamination. Regulation and oversight of the drilling industry will not be accomplished easily, especially in a state like Pennsylvania, where the state government is a wholly-owned subsidiary of the natural gas industry.

Secondly, the absence of evidence of leakage due to fracking, per se, does not necessarily mean that there is none and the process is safe. Methane and fracking fluid from deep in the shale may simply take a longer time to reach the surface than chemicals that leak from at or near the surface. Maybe decades. The Darrah study may simply have been done too soon.

Meanwhile, there is accumulating evidence of another problem caused by natural gas drilling. A new report published in the Bulletin of the Siesmological Society of America shows a significant increase in earthquakes in the Raton Basin of Colorado and New Mexico since 2001. Fracking began there in 1999. As in previous studies, most of the earthquakes are located within 5 kilometers of waste water injection wells, rather than near sites where hydraulic fracturing has taken place. I guess that means that fracking is “safe,” but it doesn't solve the problem of what to do with the waste water.

You may also be interested in reading:

Fracking and Public Health, Part 1

Fracking and Public Health, Part 2

La Terra Trema

La Terra Trema

I can remember a time when, if you raised the possibility that fracking might cause earthquakes, the natural gas industry treated you as if you were a nutcase. But now it's official. The Ohio Department of Natural Resources (ODNR) has confirmed that a series of a dozen earthquakes in the Youngstown, OH area, includinging a December 31 earthquake on that measured 4.0 on the Richter scale, were caused by the underground injection of fracking wastewater at the Northstar 1 disposal well. So if you felt the earth move on New Year's Eve, you weren't drunk, you had just been fracked.

While wastewater had been presumed to have caused earthquakes in Arkansas, Oklahoma and Great Britain, the evidence in this case is much stronger. After the first few quakes, ODNR hired seismologists from Columbia University's Lamont-Doherty Earth Observatory to investigate. When seismographs were placed in the area, the geologists determined that the epicenters of subsequent quakes were within .8 kilometers of the injection site at the same depth (3 km), and were caused by slippage along a previously unmapped fault.

Operations at the well have been stopped, and ODNR has issued new rules in Ohio. They have banned injections below 8,000 feet. They will require pressure and volume monitoring, and automatic shutoff systems. Finally, they will require electronic tracking of wastewater entering from outside the state. Presumably, there will be no attempt to fine D&L Energy, the owner of the well. Nevertheless, a D&L released a statement disputing the findings, claiming that ODNR opted for “a politically expedient preliminary report that sacrifices true understanding for haste.”

Defenders of fracking were quick to point out that wastewater injection is not the same as fracking, the process by which natural gas is extracted, which also involves underground injection of fluids at high pressure. They said that fracking takes less time than injection of wastewater. Is time the critical variable? Other possibilities would seem to include the volume of fluids deposited in the ground, the depth of the drilling, and the pressure required to do it.

Although disposal of wastewater is only one of many public health problems associated with fracking, it is one of the most serious. There are approximately 144,000 gas wells in the U. S. producing 2 billion gallons of wastewater every day. Wastewater consists not only of fracking fluid, which contains known carcinogens and toxins, but also material brought up to the surface from the shale, including radioactive heavy metals.

There are three options for disposing of wastewater. (1) What they call “recycling” involves diluting it with fresh water and reusing it for subsequent fracking. However, eventually toxins accumulate and it can no longer be reused. (2) At this point, it could be sent to water treatment plants, but most existing plants are inadequate to treat these toxins. Wastewater sent to Western Pennsylvania treatment plants produced measurable increases in bromides, which are linked to cancer and birth defects, in the Monongahela River. (3) That leaves underground injection.

These earthquakes occurred in part because there was an “unmapped”—that is, unknown—fault in the area. What percentage of faults are known? That's unknown. (Duh.) Researchers say the only way to prevent future earthquakes is to do a seismic survey of the area prior to constructing the wastewater facility. Such a survey would cost $10 million per well. I'm sure the industry will be happy to oblige.

Pennsylvania, unlike Ohio, does not even monitor wastewater disposal facilities, but relies on the Environmental Protection Agency to handle permits for these facilities. An EPA spokesman, Jon Capacasa, said this could not have happened on their watch because they require companies seeking permits “to identify known faults . . within a mile of a proposed well site.” (Italics mine.) But of course this fault was unknown. I guess he didn't read the report.