At a recent shale gas symposium in South Africa a question was asked “if hydraulic fracturing is so safe, why do drilling operators working in Pennsylvania’s Marcellus Shale Play dispose the backflow out of state in Ohio.” The question was satirically proposed by a rather uninformed anti-fracking environmentalist. His point was to show that even a natural gas producing state wants nothing to do with the disposal of the hydraulic fluid’s flowback (chemical-laced wastewater).
This discussion addresses the attendees question from a chemical perceptive. It is not intended as a review of the relationship between wastewater injection wells and earthquakes. Let it suffice to say that injection well seismicity typically ranges from 1 to 4 on the Richter scale and rarely cause damage. Nevertheless, the industry is minimizing the risk of seismicity by: assessing susceptibility when identifying or permitting injection sites; requiring seismic monitoring at active well sites; limiting well pressure thresholds by decreasing the amount of water pumped into wells and reducing the pressure at which it is pumped; and recycling and reusing wastewater.
Hydraulic fracturing is the process used to stimulate gas production from conventional oil and gas reservoirs. The process requires between 3 to 5 million gallons of fluid per well. The fracturing fluid is a proprietary mixture consisting of at least 98% water and sand with the remaining 2%, or less, of chemical additives, each having a specific function.
Although there are dozens to hundreds of chemicals, which could be used as additives, typically, there are no more than 12 chemicals used in the fracturing process. Most of the additives are commonly used household or personal care items, which pose little or no health risks. However, a limited number are classified hazardous substances.
After stimulation, about 20% to 40% of the fluid flows back to the surface and disposed by any one of a number of options. The four most common disposal options are: recycling for additional fracking, treatment and discharge to surface waters, underground injection, and storage in open air pits.
The answer to his question has nothing to do with Pennsylvania’s supposed dismay of the fluid. The answer is matter of simple geology. Pennsylvania’s tightly formed low-porosity underground geology is not suitable for deep injection disposal wells. Correspondingly, Ohio’s geological underbelly composed of deep, cavernous permeable rock formations are ideally suited for injection well holding tanks.
When injection is the most practical solution, the flowback is injected in deep, up to 10,000 feet, underground porous rock formations and sealed above and below by unbroken, impermeable strata. Ohio is home to 176 injection disposal wells, operated by more than 80 companies. Compare that with just six active wells in neighbouring Pennsylvania. “There are over 151,000 injection wells around the country injecting over 2 billion gallons of brine every day. Since the 1960s, there have only a handful of incidents due to direct contact or chemical migration into aquifers.”
Both horizontal drilling and hydraulic fracturing are established technologies with a significant track record; horizontal drilling dates back to the 1930s; and hydraulic fracturing has a history actually going back as far as 1860’s, when nitroglycerine was used to stimulate shallow, hard-rock oil reserves, it was surprisingly very successful and not so surprising very hazardous and often illegal.
A key element in the emergence of shale gas exploration has been the refinement of cost?effective horizontal drilling and hydraulic fracturing technologies. These two processes have allowed shale gas development to move into areas that previously were not accessible, literally your backyard.
The possible harmful effects of the fracking fluid to people and planet cannot be minimized. A 60-year history dictates that hydraulic fracturing is safe. There are few, if any, known cases of anyone being hospitalized or harmed from chemical contact with the fracturing fluid and/or its flowback. Especially, when used in a safe and responsible manner! “Best Management Practices” employed to select sites with the proper geology, construct and cement the casing, and manage the handling, injecting and disposal have just about eliminated problems and complaints.
The dilemma with all this brouhaha over hydraulic fracturing is the lack of concern over:
1. Sodium fluoride found in almost every tube of fluoridated toothpaste, which is far more hazardous and toxic than any of the additives in the hydraulic fracturing fluid.
Sodium fluoride is toxic by ingestion, inhalation and skin contact. “Fluorides are more toxic than lead and only slightly less poisonous than arsenic. As of April 7th, 1997, the United States FDA (Food & Drug Administration) has required that all fluoride toothpastes sold in the U.S. carry a poison warning on the label. Another of the little-known facts about fluoride toothpaste is that each tube of toothpaste – even those specifically marketed for children – contains enough fluoride to kill a child.
Fortunately, however, toothpaste-induced fatalities have been rarely reported in the US. In a review of Poison Center Control reports between 1989 and 1994, 12,571 reports were found from people who had ingested excess toothpaste. Of these calls, 2 people – probably both children – experienced “major medical outcomes”, defined as “signs or symptoms that are life-threatening or result in significant residual disability or disfigurement,” see following chart.
2. The environmental impact and water pollution caused by deicing salt. Salt the most commonly used deicing chemical in the United States; it is spread at a rate of approximately 20 million tons per year. “The U.S. Environmental Protection Agency (EPA) does not regulate road salt but acknowledges that special consideration and best management practices are needed to protect reservoirs and other drinking water supplies near treated highways and salt storage sites from contamination with road salt runoff.”
3. The presence of gar gum in natural toothpaste. Guar gum or hydroxyethyl cellulose is one of the hazardous additives used in hydraulic fracturing fluid to thicken the water in the fracturing fluid to suspend the sand. Neither its identity nor concentration is labeled on most tubes of toothpaste.
4. The use of ethylene glycol in many household products, including antifreeze, deicing products, detergents, paints, and cosmetics. Ethylene glycol is a colorless, odorless, sweet-tasting toxic additive used in hydraulic fracturing fluid to prevent scaling in the drill pipe.
“Ethylene glycol that is released into the environment does not persist since it is degraded within days to a few weeks in air, water, and soil. Reports of fatalities following ingestion of ethylene glycol indicate that a volume of 150–1,500 ml consumed at one time may cause death. In humans, the lethal dose of ethylene glycol is estimated to be in the range of 1,400–1,600 mg/kg. Ethylene glycol vapor concentrations measured in the air at airports during de-icing spray operations ranged from 0.05 to 22 mg/m3. Ethylene glycol has also been detected in airport stormwater. Background concentrations of ethylene glycol in the environment are not available.”
5. The dry cleaning of clothes. “You know that smell on clothes that have been to the dry cleaners? Well, for the first time scientists have measured it and found worrying levels of the toxic chemical used most commonly in the dry cleaning process. Most dry cleaners use an oil-based solvent called “Perc” (short for perchloroethylene) that has been linked to serious health problems, particularly for workers or nearby residents who inhale fumes, or for those drinking water contaminated with the chemical. The chemical is such a potent toxic substance that it’s prompted federal and state hazardous waste cleanups at dozens of Superfund sites around the country, some of them at defunct cleaners that didn’t handle their waste properly. And, not surprisingly, the chemical remains on clothes after they come home from the dry cleaners, and even build up over time if clothes are repeatedly dry cleaned, according to a Georgetown University study that was inspired by a sophomore high school student’s science project.”
6. Throwing something away. If you don’t reuse or recycle that item, it probably will end up in a landfill. Once in a landfill the only thing left for it to do is decompose into carbon dioxide, water, hydrogen, ammonia, carbon dioxide, inorganic acids, and methane. “In 2010, Americans generated about 250 million tons of trash and recycled and composted over 85 million tons of this material. On average, we recycled and composted 1.51 pounds out of our individual waste generation of 4.43 pounds per person per day.”
“Decomposition rates (rate at which it will totally break down into the earth) of items in landfills will vary depending on the amount of sunlight, moisture and air exposure it receives. Some of these time ranges are:”:
“Apple core: 1 to 2 months, can take longer in landfills due to lack of microbes
Glass bottles: tens of thousands of years; glass is made from sand and it can outlast most anything
Plastic drinking bottles: hundreds of years; consist of polyethylene terephthalate (PET) which is made from petroleum, which won’t break down.
Plastic bags: up to hundreds of years; newer plastic bags can photo-degrade, but most aren’t exposed to sunlight when in a landfill.
Milk carton: 5 years
Plastic milk jug: 500 years
Aluminum can: 80 to 200 years
Styrofoam: no sign of ever breaking down
Cigarette butt: 1 to 5 years
Newspaper: 2 to 4 weeks, can take longer in landfills due to lack of microbes; will decompose much faster when wet.”
7. The December 2008 report that “one in every three of the more than 1,500 children’s toys tested in time for the holiday shopping season have been found to contain “medium” or “high” levels of chemicals of concern such as lead, mercury, cadmium and arsenic.”
In closing, it’s convenient and easy to point at hydraulic fracturing as another human activity that if not curtailed will destroy humanity. The ascent of man is one of risk management and ultimately doing the right thing. Sure controls, oversight and improvements are necessary when our future is at stake. But let’s deal in facts rather than mindless cut and pastes that naysayers righteously proclaim to an unwary public who go about brushing their teeth, driving behind salt spraying trucks, sitting in aircraft during deicing procedures, sending their clothes to the local dry cleaner, buying toys for birthdays and holidays, and shopping to feed and clothe the family without thinking of the potential harm they are doing to themselves and mother earth. Time to put fracking in proper perspective!
By. Dr. Barry Stevens