Excessive Contaminated Water Results from Drilling & Fracking Operations

Studying the contaminated water that comes up from fracking

Essay by S. Tom Bond, Retired Chemistry Professor and Resident Farmer, Lewis County, WV

Slick water hydraulic fracturing, as most readers know, is using water solutions to break shale rock far below the earth’s surface, so that gas from pores containing oil and gas may be mobilized and brought to the surface.

The pores are very irregular in shape and size, ranging from a micrometer to a few hundreds of micrometers in dimensions, the size of a typical bacterium to the diameter of a human hair.

Pressures used at the surface are typically are up to 10,000 pounds per inch (psi), and at the depth the shale being fractured, more by the weight of the column of fracking liquid, which frequently goes than a mile down. At one mile down, if the fracking solution has the density of water (and it would usually be more) the pressure would be up to 12,280 psi. Over six tons to the square inch!

As the reader knows, temperature goes up as the depth increases, and the temperature is about 180 Fahrenheit at that depth. You don’t get far into chemistry without learning that solubility of substances is different, usually greater, at elevated temperature. Pressure also affects solubility, very much for gases, but usually somewhat less than for temperature. A particularly important pressure effect in drilling involves calcium sulfate, which precipitates out on the way up. Other solubility effects may be involved at these extreme pressures.

So, at this point, you and I have these understandings: the pores are very tiny and irregular, and the solubility of compounds is different at the bottom of the hole. Let’s add one more, it takes about ten barrels of water to produce one barrel of oil or gas energy equivalent to a barrel of oil.

All the solution that goes down the hole, in the order of 4.4 million gallons (105,000 barrels), more or less, since individual wells vary a lot, does not come back up when the pressure is allowed to drop. What does is called “flowback,” and amounts to 20 per cent, again more or less, while the rest stays in the ground. What comes up has the chemicals in it that went down, diminished in quantity by reactions below, plus such chemicals as result from the reaction and what chemicals will dissolve out of the formation quickly.

Flowback occurs for a few days, diminishing to a smaller constant flow. This smaller flow lasts the productive life of the well, some 7 or 8 years, and is called “produced water.” Produced water is more strongly influenced by what dissolves in water underground, and in time includes more water in the formation which has been there for millions of years.

Solutions that come up, flowback and produced water, usually go in the same holding pit, which is lined with one or two layers of 60 mil polyethylene plastic.

What we call fracking sprang from the ground full grown like the fierce warriors which from dragon’s teeth sown by Cadmus in Ancient Greek mythology.

This is very much unlike other large scale chemical industry operations. It did not go through a pilot plant stage and scale up stage, with careful analysis of effluents by chemists. Diverse entrepreneurs tried it with the old mixtures used in vertical fracking, with additives they thought might be helpful. No doubt salesmen from suppliers played a far more important part in drillers choices than engineers.

There is an illustration of the quantity of chemicals used in a typical well in Beaver County, Pennsylvania here. The quantity of chemicals shown is 757 barrels, including 373 barrels of “mystery chemicals,” so called because the identity is not known to the public. The reason given to the public and regulators is that this is “proprietary information.” It would give competitors an advantage if they could use them, too. The reader can take that claim as he/she sees fit.

So, here we are, a decade after fracking appeared to be heading for the big time, wondering what those “mystery chemicals” are. And wondering what else, and how much of it comes up with water from the deep. An important recent contribution to the question of what comes up that originates from the shale formation is an article titled “Scientists seek more data on existing water in shale formations,” located here.

The article is concerned with the composition of the water in the formation (really, what is dissolved in it) before fracking and thus can come to the surface. The reason for studying this “super-salty liquid with elevated levels of heavy metals, radium and other chemicals” is to “lead to safer disposal options and other actions to protect public health and the environment,” according to the article’s author.

Is there such a need? There certainly is. This “brine” has been eagerly sought by some road authorities as a dust suppressant and for a wintertime de-icer. “Brine” is widely understood by many people to be a salt (sodium chloride, ordinary table salt) solution. The fact is that chemists use “brine” for a a large category of compounds, not just one. Salts are the product of reaction between metals and highly non-metallic elements. Some are harmless and some are poisonous. Soluble barium compounds, some times present in these waters, are very poisonous.

The reader hardly needs to be warned about radioactivity. “Acceptable” levels of radiation have declined dramatically from when I first became aware of the “acceptable” concept in the 1950′s while an instructor at the Army Chemical Corps training school. I will predict they will decline further in the future.

An immense class of poisonous compounds is known, both organic and salts, that are called “endocrine disrupters”, but hardly recognized in formal toxicology. The endocrine glands are the ductless glands of the body, such as the pituitary gland, the thymus, the thyroid and parathyroid, the adrenal gland and many others. Their hormones go directly to the blood, in very small amounts, as with various body processes. Frequently they control other glands which produce far larger quantities of hormones.

Due to the small amount of hormone produced by these glands, a very small amount of disrupting toxins is needed to destroy their function, and disrupt body processes. These compounds, because they are present in such small quantities are difficult to analyze and study. Often, the amount required is near the limit of chemical detection.

“So to be able to understand all these things, we really need to understand the natural formation water,” says Madalyn Blondes of the United States Geological Survey, quoted in the article. The change from “flowback” water to “produced” water over time makes determining the composition of the water originally in the formation particularly difficult. Knowledge of composition also improves drilling efficiency by reducing “salting out” (deposition of solids, such as calcium sulfate) in drilling equipment.

Water in the shale formation started out as ancient sea water, which became more concentrated as the water evaporated. Some of what is there today exists in pores of the shale or surrounding formations and other could have been precipitated into the rock, but is re-dissolved by the fracking solution. Taras Bryndzia, a geologist with Shell International Exploration and Production, Inc., says of his research: “This data also showed that some brine could come from an adjacent layer.” Brian Stewart, a geologist at the University of Pittsburgh believes, “Indeed, it would be unlikely for the Marcellus shale layer to be the source for all of the produced water.” They have analyzed drill cuttings from the State of New York. “There’s not enough salt or water in those pores to really explain the super salty water that comes back,” Stewart said.

Stewart acknowledges the possibility of cracks outside the shale layer and even to the level of shallower wells above, but thinks contamination of ground water is from improperly functioning new well with leaks near the surface.

Fracking has been developed largely through trial and error by entrepreneurs. Let us hope more and more science, including solution chemistry and toxicology, can be applied as soon as possible.

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Tagged as: contaminated water, drilling, endoctrine receptors, flowback water, fracking, marcellus shale, produced water, public health, Utica Shale, water consumption, water pollution