Let’s consider a typical hydraulic fracturing (fracking) operation at a natural-gas well in Beaver County, Pennsylvania. This particular frack site is right in the middle of Marcellus Shale country and lies along the state’s western border, in a rural community similar to many throughout the mid-Atlantic region. The nearest house is approximately 300 feet away and the nearest neighborhood is 1200 feet away. Within 3000 feet of the site lies a sprawling golf course and a small community of 20 houses. The frack site itself is in the center of a farm field in an agricultural setting, and is operated by Chesapeake Energy Appalachia LLC.

Location of the frack site; note proximity to farms and houses

With such close proximity to a small community, the chemicals used in the fracking procedure certainly raise concerns.  So…what exactly is in “fracking fluid” anyway?  FracFocus.org is the website used by the drilling industry to voluntarily publish their frack site information (i.e. location, ingredients in frack fluid) for the public to see, and a quick look at it’s ingredients list should help to answer our question.

The ingredients list for this specific frack reveals a seemingly innocuous mixture (for a fluid that, y’know, breaks open rock thousands of feet below the ground). The fracking fluid consists mostly of water (89% by weight) and sand (10.38%). These ingredients amount to 25,025 tons of fluid. The remaining 0.52% of the mixture is made up of an additional 133 tons of chemicals that must be trucked onto the site.

Chart with identifying information on frack site studied (Source: FracFocus.org)

Though most of the individual chemicals are less than one ton, there are larger amounts of certain ingredients. For instance, hydrogen chloride (hydrochloric acid) totals a whopping 41 tons. Other ingredients, such as a ‘carbohydrate polymer’ comprise 33 tons, and a ‘synthetic organic polymer’ makes up 21 tons of the fluid. Other high-amount ingredients include tetramethyl ammonium chloride (13 tons), ‘aliphatic polyol’ (11 tons), potassium hydroxide (5.5 tons) and hydrotreated petroleum distillate (3 tons).

Excerpt from FracFocus data sheet showing amount of hydrogen chloride (hydrochloric acid) used in Chesapeake frack. Amounts in FracFocus are given as total percentage of the frack fluid by weight, not a very meaningful way to present this information to the public.

The problem is the incomplete disclosure of these chemicals. Each ingredient I’ve listed in the above paragraph in quotation marks has a generic name, and is lacking a Chemical Abstract Service (CAS) number that specifies what the chemical really is. Counting the three ingredients I’ve already listed in this article (the aliphatic polyol, the carbohydrate polymer and the synthetic organic polymer) there are a total of six ingredients in this particular mixture that have no CAS number. Totaled, this means almost half of the chemicals listed (by weight) have been purposely unaccounted for.

That’s right:  65 tons of mystery chemicals trucked down narrow country roads past farms, homes and schools, and injected into the ground:

Comparison of chemicals accounted for and chemicals not identified (red).