MUST (LONG) READ! Special Issue of Journal Environmental Science and Health, Part A: Toxic/Hazardous Substances and Environmental Engineering: Facing the Challenges – Research on Shale Gas Extraction

Special Issue: Facing the Challenges – Research on Shale Gas Extraction Series of articles Published online March 3, 2015, Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances and Environmental Engineering, Volume 50, Issue 5, 2015, DOI:10.1080/10934529.2015.992649

2015 03 03 Toxic Hazardous Substances Environmental Engineering, facing the challenges of fracing, shale gas

Foreword by John F. Stolz Professor, Biological Sciences, Directora

The exponential increase in the development of natural gas and oil from tight shale reserves seen in the last decade has been due to the combination of advances in drilling technology (e.g., horizontal drilling) and the technique of hydraulic fracturing. Unconventional drilling for gas and oil is now occurring in over 30 states including North Dakota (Bakken), Texas (Barnett), Louisiana (Haynesville) Wyoming (Green River), Pennsylvania, Ohio, and West Virginia (Marcellus, Utica). This remarkable increase in production has resulted in optimistic predictions for energy independence and economic development.

Similar to other historic boom periods, however, this rapid expansion has posed many challenges. In Pennsylvania, where in just the last 5 years 12,665 permits have been granted and over 5,700 unconventional wells drilled, regulators have been hard-pressed to keep up with well pad inspections. The large volumes of water needed for the hydraulic fracturing process (3–5 million gallons) and the size (3–7 acres) and number of well pads required for shale play development raise questions about possible ecological impacts.
The wastewater (flow back and produced water) generated from the process is high in total dissolved solids with elevated concentrations of chloride, bromide, strontium and barium, as well as NORMs. Its disposal has been non-trivial given the volume and concentrations; certain areas of the country have experienced earthquakes induced by the influx of wastewater disposed of via Class II injection wells. Incidents of well water contamination by fugitive gas migration and other constituents have accompanied the drilling. Rural towns have seen dramatic increases in truck traffic and population growth. Although landowners with mineral rights, and service industries (e.g., food, housing, trucking) have seen economic benefits, there has also been local inflation and stress on infrastructure (e.g., roadways, law enforcement, schools, housing).

A number of private foundations have been supporting a growing number of researchers at academic institutions and non-governmental organizations (NGOs) to investigate the wide range of issues related to the shale gas boom. It was, thus, of great interest to gather as many of these researchers to present their findings in a forum open to the public and to stimulate peer reviewed publications. A special symposium “Facing the Challenges—Research on Shale Gas Extraction” was held at Duquesne University, November 25–26, 2013. The two-day conference hosted 22 oral presentations and 20 posters, as well as a gallery presentation of the photo documentary “Faces of Marcellus” and a showing of selected videos from the video documentary “Gas Rush Stories.” The presentations covered a wide range of topics including ecologic impacts and forest fragmentation, gas well leakage and casing failures, climate change, air quality, water usage and monitoring, well water quality, isotopic signatures as tracers, human and animal health exposures, as well as local governmental responses and the socioeconomic impacts of the boom-bust cycle. The presentations were recorded and are accessible on the Duquesne University Center for Environmental Research and Education website (

I organized the symposium, along with Ms. Samantha Malone, Graduate School of Public Health of the University of Pittsburgh and FracTracker Alliance. We are both employed in Pittsburgh, Pennsylvania. We would like to acknowledge the Heinz Endowments, Colcom Foundation, Claneil Foundation, and George Gund Foundation for their generous support of the conference. We are most grateful to Philip Johnson of Heinz Endowments, for not only suggesting the conference but also helping to make it a reality. We would like to thank those who have contributed manuscripts to this special issue of Environmental Science and Health, Part A, the anonymous reviewers, Dr. Philip Reeder, Dean of the Bayer School of Natural and Environmental Sciences, who initiated the process, and Dr. Shahamat U. Khan, Editor-in-Chief, for his continued interest and coordination of our efforts.


Current perspectives on unconventional shale gas extraction in the Appalachian Basin by David J. Lampe & John F. Stolz, March 3, 2015

The Appalachian Basin is home to three major shales, the Upper Devonian, Marcellus, and Utica. Together, they contain significant quantities of tight oil, gas, and mixed hydrocarbons. The Marcellus alone is estimated to contain upwards of 500 trillion cubic feet of natural gas. The extraction of these deposits is facilitated by a combination of horizontal drilling and slick water stimulation (e.g., hydraulic fracturing) or “fracking.” The process of fracking requires large volumes of water, proppant, and chemicals as well as a large well pad (3–7 acres) and an extensive network of gathering and transmission pipelines. Drilling can generate about 1,000 tons of drill cuttings depending on the depth of the formation and the length of the horizontal bore. The flowback and produced waters that return to the surface during production are high in total dissolved solids (TDS, 60,000–350,000 mg L−1) and contain halides (e.g., chloride, bromide, fluoride), strontium, barium, and often naturally occurring radioactive materials (NORMs) as well as organics. The condensate tanks used to store these fluids can off gas a plethora of volatile organic compounds. The waste water, with its high TDS may be recycled, treated, or disposed of through deep well injection. Where allowed, open impoundments used for recycling are a source of air borne contamination as they are often aerated. The gas may be “dry” (mostly methane) or “wet,” the latter containing a mixture of light hydrocarbons and liquids that need to be separated from the methane. Although the wells can produce significant quantities of natural gas, from 2–7 bcf, their initial decline rates are significant (50–75%) and may cease to be economic within a few years. This review presents an overview of unconventional gas extraction highlighting the environmental impacts and challenges.

Drilling for gas and oil is not new to Pennsylvania as the first commercial oil well is credited to Edwin L. (Colonel) Drake. Drilled in Titusville in 1859 it led to the first domestic oil boom.[7,8] Since then it is estimated that more than 300,000 to 500,000 oil and gas wells have been drilled in Pennsylvania.[9] As the requirement for permitting only began in 1956, the location of many of these wells, and whether they were properly plugged remain in doubt and an abandoned well plugging program is maintained by the state’s Department of Environmental Protection (PA DEP). Although the first boom ended by the turn of the 20th century, Pennsylvania continued to support an active oil and gas industry prior to the current boom in unconventional wells, with upwards of 7,000 conventional well permits granted each year.

After the first successful test wells in the Marcellus in 2005, however, momentum began to swing towards unconventional methods. By 2011 permits for unconventional wells outnumbered conventional (Fig. 2). According to the PA DEP website, over 15,000 permits have been granted since 2005 and over 7,400 unconventional wells have been spudded (i.e., drilling of the unconventional well has started).[10] Unlike the previous boom, which occurred primarily in rural areas and saw towns like Pithole and Petrolea rise and disappear as quickly,[7,8] the new drilling is occurring not only in rural areas, but well established suburban and more urban locations with high population densities. This phenomenon is not restricted to Pennsylvania. There are more than 1,400 unconventional Barnett Shale wells within the city limits of Fort Worth, Texas and 110 lateral wells (out of the 330 originally planned) lie beneath the tarmac and properties of the Dallas-Fort Worth Airport.[11]

Although drilling is banned presently in the city of Pittsburgh, Allegheny County in which Pittsburgh lies, has recently signed an agreement with Huntley and Huntley and Range Resources to allow them to drill under Deer Lakes County Park[12] and have also leased the mineral rights under the Pittsburgh International Airport to CNX, a subsidiary of Consol Energy.[13] Rural towns have seen dramatic increases in truck traffic and population growth. While landowners with mineral rights, and service industries (e.g., food, housing, trucking) have seen economic benefits[14,15] there has also been local inflation and stress on infrastructure (e.g., roadways, law enforcement, schools, housing).[16]

Several studies funded by industry sources (e.g., Considine et al., 2009, 2010)[14,15] have come under scrutiny for inflating the economic impacts as a result of overstated assumptions (e.g., 95% of industry spending would occur within the state; royalties to landowners would be spent immediately and within the state) and using a more suitable economic model that was more sensitive to changes in drilling activity such as natural gas price and other variables.[17] The economic gains that may be garnered from drilling must be weighed against existing industries such as agriculture, tourism, outdoor ventures (e.g., fishing, hunting, and camping), and wineries, which may be substantially impacted or lost. For example, a recent study by the Penn State Extension documented a loss in number of dairy cows of around 18% in areas with Marcellus drilling activity.[18] The investigators were not able to establish from their data whether the farmers were using the new source of revenue to leave the business or to merely shift their farming activities away from milk. Nevertheless, there was concern that the drop in the number of animals and concomitant decrease in milk production could negatively impact supporting businesses such as large animal veterinarians, feed suppliers, and dairy processors.[18]

The large number and size of the storage containers for the water, chemicals, and proppant, the mixers and pressure pump trucks, as well as the accommodations for control operations, require a well pad of sizable dimensions, often 3–7 acres (Fig. 3). The well pads pose a striking figure against the rural countryside of Western Pennsylvania (Fig. 4A). The water for fracking is usually obtained from streams, rivers, and lakes (Fig. 4B) or from the public water supply. In Pennsylvania 80% comes from untreated surface water with the remaining 20% from public water supplies.[24] … The water is trucked to large impoundments that may hold upwards of 10 million gallons and cover significant acreage (Fig. 4C).

In Pennsylvania, multiple casings are required, with an additional intermediate string needed if coal seams are encountered (Oil and Gas Act of 2012). … Each well produces around 1,000 tons of drilling waste (ground up rock and drilling mud) that may contain a variety of salts, heavy metals, and naturally occurring radioactive materials (NORM) most notably uranium, radium, and radon.[30]

This drilling waste may be buried on site or, more typically, transported to landfills. [In Alberta, the waste is dumped on agricultural land in exchange for a small fee paid to landowners and lies:companies sell the waste dumping by telling landowners the waste is free fertilizer] … Like the drilling, fracking is done in stages, usually from 8 to 10. First, the production string must be “perfed”, exposing the well bore to the rock. This is accomplished with a perforating gun, a device that sets off explosive charges in all directions. Once the perfing is done, that stage of the well bore is fracked. This involves injection at high pressure (5-10,000 psi) of the fracking solutions, the composition of which is detailed next, and proppant (fine-grained sands).

The fluids may be pumped in at rates upwards of 3,000 gallons per min.[22] This process enlarges the natural fractures and inducing new ones in the rock releasing the trapped gas. This is repeated several times down the well bore. The last bit of piping is the production tubing. During completion, the well is usually flared as a means to control the back pressure. Flaring usually lasts a few days but in some cases several months depending on the well and whether gathering lines are available.[31]

Usually there are two condensate tanks per well, but there may be many more depending on the number of wells (Fig. 4F). They are marked with hazard placards indicating the contents are flammable and toxic (Fig. 4G), as the produced water contains volatile organic compounds (VOCs). The tanks are designed with “blow off” relief valves that release the VOCs as the fluids in the tank increase and the pressure builds. Invisible to the naked eye, these volatiles can be seen with specially designed infrared cameras. Compounds such as propane, n-butane, iso-butane, n-hexane, n-heptane, n-pentane, iso-pentane, methylpentane, toluene, and xylenes as well as benzene, cyclohexane and methylcyclohexane, have been detected in the air around condensate tanks in the Barnett and Marcellus plays.[32–35] Grover and Stattler[34] found that o-xylene, m- and p-xylene, benzene, ethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and toluene were particularly associated with compressor stations. The release of VOCs, especially BTEX (benzene, toluene, ethyl benzene, and xylene), contributes to declining air quality.[29,36]

The production of photochemical smog can result from the truck and compressor diesel engine emissions, VOCs, nitrogen oxides (NOx), and methane leakage from well sites. The town of Pinedale in Sublette County, WY, despite its low human population density has serious air quality issues related directly to the nearby gas field.[29,37] The recent ozone study from the Uintah Basin in Utah indicated levels of 142 ppb, exceeding the EPA 8-hour standard of 75 ppb.[38] The high ozone coincided with elevated levels of methane, VOCs, and NOx, and could be attributed to the natural gas and oil operations in the basin.[38]

The product from the Marcellus in Western PA is not dry gas but a combination of other organics. These “wet gas” products (e.g., ethane, propane, butane, drip gas) are separated in refineries (Fig. 4I). These complexes are also a source of VOCs and frequently flare off residual organics. These facilities are permitted as individual units that comply with emission standards. However, when multiple facilities (e.g., processors, compressors) are aggregated the cumulative emissions can be significant. There have been 462 compressor stations and processing plants built in Pennsylvania since 2008, a more than ten fold increase over what existed previously, contributing an additional tens of thousands of tons of emissions (including NOx and SOx) annually.[42]

Composition of fracking fluids

Over 600 chemicals have been used in the various frack fluid formulations as reported by the US DOE,[52] US EPA,[53] the US House of Representatives Committee on Energy and Commerce,[54] and Colborn and colleagues,[55] but may contain just a few dozen components. The basic constituents include surfactants (non-ionic detergents, to increase recovery), friction reducers such as granulated anionic polyacrylamide and petroleum distillates (providing the “slick” in slick water stimulation), scale inhibitors (e.g., ethylene glycol, to prevent formation of calcium carbonates and calcium, barium, and strontium sulfates), corrosion inhibitors (e.g., N,N, Dimethyl formamide), crosslinkers and gelling agents (e.g., guar gum, to control viscocity), acid (usually hydrochloric, to aid in the fracturing and dissolving the rock), and biocide (e.g., glutaraldehyde, to control bacterial growth).[55]

The exact composition of this mixture depends both on the company doing the fracking, and the geographic location, as even the same shale formation can have different characteristics depending on its geologic history. The components are not added all at once but in steps, first the acid, corrosion inhibitors, and iron controllers are added followed by the friction reducing agents.[22]The crosslinkers and gelling agents are then added along with the fine-grained proppant. This is followed by coarser proppant, along with biocide, clay stabilizers, and breakers, with the last stage being the flush, a bolus of freshwater or brine.[22]

Although most of the additives are known, there are several components that are proprietary in nature and have designations on the Material Safety Data Sheet (MSDS) that are undefined and often without a Chemical Abstract Service (CAS) number. Some components are listed by trade name, such as the commonly used biocide EC6116A that is composed of dibromoacetonitrile (1–5% w/w/) and 2,2-dibromo-3-nitrilopropionamide (10–30% w/w) dissolved in polyethylene glycol (30–60% w/w). Proprietary tracers, usually rare earth elements such as iridium and gadolinium, may also be employed to aid in determining the extent of each fracking stage.

Flowback and produced water

As mentioned above, a significant volume of fluids are injected during hydraulic fracking, but eventually return back up the well due to pressure from the overlying rock strata (e.g., lithostatic pressure). For Marcellus Shale, the initial flowback constitutes only about 10 to 20% of the amount of fluids that were injected. It is similar in composition to the fracking fluids that were initially injected, with low pH and lower conductivity. Over time, however, as the fluids interact with and dissolve the rock the total dissolved solid (TDS) content increases from 60,000-350,000 mg/L. This “produced water” (or production water) contain halides (e.g., chloride, bromide, fluoride), strontium, barium, arsenic and often naturally occurring radioactive materials (NORMs) as well as organics.[56–61]

In Pennsylvania, while the condensate tanks have hazard placards indicating the toxicity and flammability of the produced water (Fig. 4G), the trucks draining the tanks are labeled “residual waste” and “brine”. Regardless, it is toxic to fauna and flora.[62]Although the amount of waste water generated per unit of gas produced may actually be less than a conventional well, the total over the past decade has exceeded the state’s treatment capacity.[63] Publicly owned wastewater treatment plants (POTWs) in Pennsylvania are allowed to take produced water volumes of up to 1% of their total daily output. POTWs are not designed to “treat” produced water but merely dilute the salts. This results in increased total dissolved solids (TDS), bromide in particular, in local rivers.[64,65]

The bromide has caused problems with public drinking water facilities as the disinfectant process by chlorination creates brominated disinfectant biproducts (DBPs) especially trihalomethanes (TMH, chloroform, bromoform, dibromochloromethane, bromodichloromethane).[66] The US EPA has strict guidelines for THMs in drinking water, requiring public drinking water facilities to inform their customers if compliance has not been met for a given reporting period. As a result many public drinking water facilities have had to convert from chlorination to chloramination to reduce the formation of THMs.[66] However, chloraminated water can cause the leaching of lead from older pipes and fittings. The practice of using POTWs for produced water disposal has been voluntarily curtailed at the behest of then Pennsylvania Governor Tom Corbett in 2011.

… The treatment of waste water and sludge can result in the production of technically enhanced naturally occurring radioactive materials or TENORMS.[67,68] Elevated levels of Radium 226 (226Ra) are commonly found in Marcellus Shale produced water.[30,69] A USGS study found a median value of 2,460 pCi/L and a high of 18,000 pCi/L.[69] A more recent study found 226Ra at 200 times background levels immediately downstream from a brine treatment plant discharging into Blacklick Creek, PA indicating the potential for radium bioaccumulation.[70]

Water management, from the water withdrawals to waste water treatment, is an important issue.[24,70–77] The use of open impoundments in Pennsylvania for flowback and produced water recycling presents several environmental hazards. They may pose a threat to surface and near surface groundwater as the liners can leak.[78,79] Improper construction or site restoration can result in erosion and sedimentation and an increase in the suspended solid load in streams.[80] Impoundments holding recycling fluids can be a source of VOCs as they are often aerated to keep the growth of bacteria and the resulting sepsis to a minimum. Both the produced water and the recycling impoundments enrich for a unique microbiota that include strict anaerobes, hydrocarbon degrading bacteria, and methane oxidizing microorganisms.[59,60,81] These organisms can be resistant to microbicides.[59,60]

Although the process of hydraulic fracturing creates mini earthquakes by design, they are small in magnitude, less than 1 Mw.[82] The large volumes of fluids (3 – 5 million gallons) and proppant (3 million pounds) used per well constitute a significant volume that causes deformation of the shale in all directions.[83] This increase in volume (1 gallon occupies 0.13368 cubic feet) can be translated through the overburden all the way to the surface and can be detected by tilt meters deployed at the surface.[83,84] The effects at the surface are reported to be negligible (on the order of microinches), however, the resultant “pressure bulb” can potentially impact faults and fissures in the overlying rock strata and exacerbate pre-existing conditions (e.g., legacy issues of mine drainage, conventional gas and oil plays, brines) ultimately affecting groundwater.

Shale gas plays developed by hydraulic fracturing have the interesting characteristic that they are very productive initially but have rapid decline rates.[88,89… The early production rates for Marcellus wells indicate a EUR of 4.4 Bcfe and a first year decline rate of 75%. Thus the wells will finish their productive stage in 3 to 5 years. In order for companies to keep their production level constant, they need to keep drilling and fracking.[88]

Groundwater contamination

Despite numerous reports of groundwater contamination due to drilling activities, from Dimock, PA to Pavilion, WY, whether fracking is at fault is still being hotly debated.[94] Part of the difficulty is whether the discussion is limited to the specific act of hydraulic fracturing or encompasses a broader interpretation to include all aspects of unconventional gas extraction. This debate has also not been helped by the fact that the Energy Policy Act of 2005 (Public Law 109-58–August, 8, 2005) section 322 specifically exempts both hydraulic fracturing and subsurface gas storage from the Safe Drinking Water Act. [Why do you think the industry needed government to give them that massive gift of industry’s deadly gas migrating free-for-all deregulation?] The US EPA study that was used to justify the exemption only reviewed reported incidents involving hydraulic fracturing of coal bed methane deposits and did not involve actual field studies or shale plays.[95] [And left out that the EPA admitted the frac’ing does risk contaminating drinking water aquifers, just like the Harper government withheld Health Canada’s 2012 frac health and water harm report that admitted significant risks from fracing to health and drinking water] The US EPA’s ongoing study on hydraulic fracturing is also limited in scope as it concerns only surface contamination.[53] [Reportedly, it sounds like it was a toothless wash from the onset.  What decent regulator, intent with protecting groundwater, would include the polluters being studied in the study design, and study itself?] The recent settlement of the Hallowich vs. Range Resources Corp (RRC) underscores the common practice of non-disclosure agreements and sealed settlements that limit public access to information.[96]  [CONT’D BELOW LEGAL ADVICE]

[Related: 2013 Alberta legal advice to frac harmed Ann Craft’s son:

“We were forced to sue after it was clear that no regulatory bodies were going to help my mom,” recalls 36-year-old O’Neil.

The oil patch veteran eventually made an appointment with Glenn Solomon, a seasoned and respected Calgary lawyer. Solomon, one of Canada’s top rated lawyers, is also a senior partner in Jensen Shawa Solomon Duguid Hawkes LLP (JSS Barristers).

The firm has close ties to both federal and provincial Tories. … The bluntness of Solomon’s comments stunned O’Neil.

In no uncertain terms, Solomon warned O’Neil that suing oil and gas companies was not only “scary” but expensive.

Solomon added that suing oil and gas regulators in addition to companies was tantamount to declaring World War Three.

Moreover, he advised O’Neil that companies typically settled fracking incidents out of court so they could frack again with limited regulatory consequences.

2013 09 23 AER lawyer Glenn Solomon 'OK we damaged your water well'2013 09 23 AER lawyer Glenn Solomon 'We'll just set you up with a tank system forever'2013 09 23 AER lawyer Glenn Solomon 'We're just happy to pay  you' for your frac contaminated water2013 09 23 AER lawyer Glenn Solomon 'by doing that, you shut up, regulators stay off our back, we get to do it again down the street'

“And by the way by doing that you (the landowners) shut up, the regulators stay off our back, (fracking companies) get to do it again down the street.”

Solomon also told O’Neil that people who sued the government, including the regulator, were “crazy.”

Solomon has been recognized as a “Top Rated Lawyer in Canada” by Corporate Counsel Magazine (2013, 2014), The American Lawyer Magazine (2013, 2014), and American Lawyer Media (2013, 2014).

Solomon is also a long-time federal Conservative party activist.

O’Neil recorded the entire two-hour-long meeting with Solomon on his cell phone: “I recorded the conversation as I wanted my mother to be able to decide which lawyer she felt comfortable with.” (Craft eventually hired a lawyer in Ponoka for her case.)

O’Neil says that he found it shocking that someone in Solomon’s position “would be so bold about how the law works in favour of oil companies in Alberta or Canada.”

More: Ann Craft’s Fracking Nightmare: A Top Lawyer’s Startling Counsel, Albertan’s son, seeking legal help, records an insider’s blunt advice on how petro giants and regulators fend off lawsuits. ]

Several different mechanisms have been proposed for contamination of aquifers.[97–100] In what now seems prescient, a hydrogeologist from Allegheny College, Samuel S. Harrison published two papers in the mid 1980s that discussed the groundwater contamination potential of hydraulic fracturing in the Appalachian Basin.[101,102] Among the routes of contamination considered were leaking slush pits (impoundments), surface discharge during fracturing or servicing, and road application of brine; from the subsurface through pre-existing natural fractures, a faulty bottom seal above the production zone as well as brine and gas from strata above the production zone; leaking from a pressurized annulus; and from casing of insufficient depth or improper construction.[101,102]

Flow of fluids towards the surface through advective transport and natural fractures may be accelerated by the hydraulic fracturing process.[97] A recent study bears out the concern for proper casing as they documented that over the past thirteen years, unconventional wells had a sixfold higher number of casing and/or cement issues reported.[103] The debate continues, however, over whether the fugitive gas is from the production zone (e.g., Marcellus shale), overlying conventional gas deposits (such as the case in Dimock, PA), or is biogenic.[104–106] Biogenic methane is produced by methanogens, microorganisms belonging to the Archaea domain. The biological process, methanogenesis, enriches for the lighter isotope of carbon, 12C, and as a result biogenic methane has an isotopic signature with strongly negative δ13C values (ranging from -60 to -120 o/oo).[100]

[Companies and regulators neglect to inform the public and “experts” that they are intentionally targeting and fracing biogenic methane]

Thermogenic methane is formed through geologic processes from fossil organic carbon (e.g., kerogen), is usually found with other light hydrocarbons (e.g., ethane, propane, propylene), and has a “heavier” (e.g., more positive) δ13C value.[100] Thus the combination of isotopic signature, light hydrocarbon composition, and other geochemical properties such as strontium isotope characterization can be used to identify the source of the contamination.[78,107] Although the methane in several water wells in Dimock, PA was shown to be of thermogenic origin the actual source is believed to be from Middle and Upper Devonian shale deposits closer to the surface.[104] 

[For obvious reasons, as determined by industry, the regulators and Dr. Karlis Muehlenbachs:

 Above slides from FrackingCanada The Science is Deafening Industry’s Gas Migration

Nevertheless, it was failed casings in multiple wells that provided conduits for the fugitive gas migration.[108] Properly constructed wells contain several casings surrounding the well pipe to prevent leakage of methane, fracking fluid, and produced water into local aquifers. [But, research, as above, indicates 70% gas leakage even with multiple casings] [99] Industry  best practices exist to limit the likelihood of casing failure although these procedures are not mandated.[29,36]


… The extraction of unconventional natural gas, however, is a heavy industrial activity involving large tracts of land, heavy equipment and vehicles, and an extensive array of pipelines, compressor stations, and processing facilities. We have presented here a brief overview of what is involved in unconventional shale gas extraction and some of the environmental impacts of these activities. Given the likelihood that Pennsylvania alone may see up to 15,000 well pads and upwards of 100,000 wells constructed over the next 20 years, it is critical that this activity be closely regulated if we are to avoid repeating past failures (e.g., orphaned wells, abandoned mine drainage). Ideally, enactment of effective policies for well siting, construction, operation, and reporting should be based on sound data. Consideration must be given to the protection of watersheds for large populations, habitat for rare and endangered species, human health and safety concerns, as well as quality of life issues. Mandating and enforcing industry best practices (e.g., green completions, improved efficiency) and minimizing the environmental impacts are essential for the preservation of our natural resources now and for future generations. [Nice recommendations for a dream; industry has have been promoting those while lying to and harming families and communities for years, everywhere they frac, enabled by corrupt politicians and deregulating regulators]

Long-term impacts of unconventional drilling operations on human and animal health by Michelle Bamberger & Robert E. Oswald

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Public health concerns related to the expansion of unconventional oil and gas drilling have sparked intense debate. In 2012, we published case reports of animals and humans affected by nearby drilling operations. Because of the potential for long-term effects of even low doses of environmental toxicants and the cumulative impact of exposures of multiple chemicals by multiple routes of exposure, a longitudinal study of these cases is necessary. Twenty-one cases from five states were followed longitudinally; the follow-up period averaged 25 months. In addition to humans, cases involved food animals, companion animals and wildlife. More than half of all exposures were related to drilling and hydraulic fracturing operations; these decreased slightly over time. More than a third of all exposures were associated with wastewater, processing and production operations; these exposures increased slightly over time. Health impacts decreased for families and animals moving from intensively drilled areas or remaining in areas where drilling activity decreased. In cases of families remaining in the same area and for which drilling activity either remained the same or increased, no change in health impacts was observed. Over the course of the study, the distribution of symptoms was unchanged for humans and companion animals, but in food animals, reproductive problems decreased and both respiratory and growth problems increased. This longitudinal case study illustrates the importance of obtaining detailed epidemiological data on the long-term health effects of multiple chemical exposures and multiple routes of exposure that are characteristic of the environmental impacts of unconventional drilling operations.

A detailed risk assessment is hindered by a number of factors. First, possible chemical exposures cannot be definitively assessed because the identity of all compounds released into the environment is not routinely available, and the concentrations and mixtures can vary over time and over pathways of exposure. Even when compounds are clearly identified in the environment, the effects of mixtures of compounds and the effects at low concentrations are poorly understood.

Furthermore, intensively drilled areas have multiple well pads closely spaced (relative to possible chemical exposures) so that the risk cannot be modeled as a simple point source but rather must be considered as multiple point sources of variable and largely unknown risk. Because tight oil and shale gas extraction has proceeded into populated areas without a full assessment of the risks, humans and animals living in intensively drilled areas have inadvertently become biological integrators of the chemicals released by this industry. For these reasons, an epidemiological approach that analyzes the health effects on humans and animals in proximity to gas and oil extraction and processing has a great deal of potential for understanding possible risks. However, analytic epidemiology requires specific hypotheses to test in a quantitative manner.

To generate these hypotheses, a phase of descriptive epidemiology is required. That is, a limited number of cases are analyzed in detail in order to describe potential health impacts and generate hypotheses for more quantitative analysis. Our 2012 study[1] of 24 cases of animal and human health problems in the vicinity of oil and gas extraction was an attempt to generate hypotheses for further analytic epidemiological studies of this process. A common thread in the studies of both companion and production animals was the effects on the reproductive system of animals exposed to chemicals associated with the drilling and production processes.

In an investigation of chemicals associated with drilling and hydraulic fracturing, Colborn and collaborators[2] have identified an extensive array of substances that could function as endocrine disruptor chemicals (EDCs). This is of particular interest because reproductive failure could be a result of toxicants that interact with endocrine receptors. Recently, Nagel and collaborators[3] have used biological assays to detect the presence of agonists and antagonists of estrogen and androgen receptors in water derived from intensively drilled areas, suggesting the presence of EDCs at biologically relevant concentrations. Water derived from areas of little extractive activity showed little or no activity on these receptors. Likewise a recent study[4] of dolphins from Barataria Bay, Louisiana, which was heavily affected by the Deepwater Horizon oil well blowout, showed significant endocrine abnormalities, in addition to a wide range of other health problems. Thus, although effects on other systems may be equally important, endocrine-mediated health impacts do seem to be associated with oil and gas exploration.

Although the effects of drilling are often seen first in animals, perhaps due to more constant exposure to toxicants, the people living in intensively drilled areas also have reported significant health effects, as noted in our study[1] and confirmed by several other studies.[5–7] In addition to studying health impacts, Ferrar et al.[5] showed that reported symptoms increased over time and clearly demonstrated the need for close monitoring of public health in communities where unconventional extraction is occurring.

Because health effects can vary over time as do exposures, we obtained follow-up information on several case studies reported in our first article as well as a number of cases that we studied following that publication. The overall question was whether health impacts have changed over time and whether that correlated with an increase, decrease, or no change in oil and gas industrial activity. Overall, symptoms have improved for families moving out of affected areas and those living in areas where the industrial activity has decreased. The findings of this and our previous study provide the basis for a more quantitative epidemiological study of the health impacts of oil and gas extraction, production and processing.

The types of wells represented are shallow vertical gas wells with low volume hydraulic fracturing (HF), deep vertical gas wells with low volume HF, horizontal gas wells with high volume HF, horizontal oil wells with high volume HF, and gas storage wells (conventional wells now used for storage). In seven cases, people primarily owned food animals, including beef and dairy cattle, goats and chickens; in five of these, the owners also kept companion animals (horses, cats, dogs and goats). In 11 cases, people primarily owned companion animals (cats, dogs, horses, goats); in two of these, owners also kept food animals (chickens). In three cases, people documented unusual wildlife losses on their properties (birds and fish); in two of these, owners also kept dogs. In more than one third of our cases, owners bred cattle, goats, chickens, horses and dogs. The number of people participating in each interview was 48. The number of food animals at the time of the first interview was 411 and included 313 cattle, 87 goats and 11 chickens; the number of food animals at the time of the second interview was 298 and included 289 cattle, 8 goats and one chicken. The number of companion animals at the time of the first interview was 119 and included 50 horses, 3 goats, 33 dogs and 33 cats; the number of companion animals at the time of the second interview was 82 and included 35 horses, 22 dogs and 25 cats.

Results and discussion

In the four cases where people moved to areas with no or very little oil or gas industrial activity, there was no reported air or water contamination. Most of the cases that have not moved (14/17) have experienced both air and water contamination, and nearly all (16/17) of cases that have not moved use alternative sources of water for drinking for themselves and their small animals. These sources include bottled water, filtered water or hauled water. Many owners of food animals (cattle, goats, chickens) and large companion animals (horses, goats and large breeds of dogs) were often forced to offer their animals contaminated water as they were not provided with a water buffalo or could not afford one. Approximately half of these cases also use alternative sources of water for bathing themselves and their animals, washing clothes and dishes, and all other uses except for flushing the toilet. [Ernst’s water is too dangerous to have connected to her howe. Ernst can’t even use her Encana-frac’d water to flush toilets with] Of cases with air contamination (14/17), only two are currently using air filters. All cases with air contamination report keeping windows shut as often as possible, keeping children and small animals inside and staying away from home as much as possible.

Table 3. Symptoms reported under each health category for humans and animals.

2015 03 04 Table 3 from Bamberger and Oswald paper

In people, the most common health impacts at the time of the interviews fell under the categories of neurological, respiratory, vascular, dermatologic, and gastrointestinal problems; there were no significant changes in health over time. In companion animals, the most common health impacts at the time of the interviews fell under the categories of gastrointestinal, reproductive, respiratory, neurologic, and dermatologic problems, and sudden death; as in humans, no significant changes in health were noted over time. In food animals, the most common health impacts at the time of the interviews fell under the categories of reproductive, neurologic, gastrointestinal, decrease in milk production, respiratory, and growth problems; significant changes in numbers of reported symptoms were noted over time in the categories of reproduction (decrease), respiratory (increase) and growth (increase) problems.

The initial spike in reproductive problems in food animals occurred because several herds were exposed directly to drilling muds and fluids, fracturing fluids or wastewater; over time, these incidents decreased. However, farmers in these cases are still reporting increased reproductive problems above what they have seen in their many years of raising cattle, especially on farms where the entire herd was exposed. Respiratory symptoms in food animals increased from the first to the second interviews; this may in part be due to the slight increase over time in exposures to processing and production operations and the fact that food animals are often on site for long periods and thus have high exposure rates. Growth problems also increased over time in food animals and may potentially have many causes, but when associated with fossil fuel operations, may be indicative of exposure to endocrine disruptors.[2,3,8]

One of these cases (Table A1, Case 10) involved the horse breeding operation mentioned above and is interesting because it has a natural control group—the horses that remained behind and continually exposed. At the time of the first interview, the manager reported air and water contamination associated with the start of gas drilling operations, and health problems in her, her dog and the horses used for breeding. After more than two years at this location, the manager and her dog moved to an area with no unconventional extraction. While the health impacts of the horses have remained the same, the health of the manager and that of her dog improved greatly after a few months. However, on a recent visit to the farm, she again fell ill but recovered after leaving. In another case (Table A1, Case 16), a participant who moved due to health problems experienced by her family and animals must periodically return to the original location to check her home. After a few hours at this location, a red blotchy rash appears on her face, neck and arms that becomes progressively worse after 48 hours; the rash will clear after a week if she does not return to this location. She has been diagnosed with dermatitis due to chemical exposure.

Comparison with previous literature

A descriptive epidemiological study cannot determine prevalence of a health impact and is not designed to determine cause-and-effect definitively. Nevertheless, in our original study,[1] we did observe the effects on herd health with natural controls that approach the controls that might be used in a laboratory experiment. That is, either dairy or beef herds were split into two or more groups, and grazed on separate pastures. In each case, one pasture or water supply was inadvertently contaminated and the remainder of the herd was not exposed. The exposed cattle suffered significantly greater health impacts than the unexposed. These spatial controls were consistent with longitudinal retrospective controls, in which herd health was compared before and after drilling began. Again, herd health suffered upon the commencement of drilling. This report represents expansion of our original descriptive epidemiological study to measure longitudinal effects since the first set of interviews.

McKenzie et al.[6] reported increased noncancer risks such as short-term respiratory and neurological health effects in people living in close proximity to well sites in Colorado, especially during the phases of hydraulic fracturing and flowback; this work follows an aborted health impact assessment to identify potential risks and benefits to a small community undergoing intensive gas development.[9] Steinzor et al.[7] included respiratory, neurological, gastrointestinal and dermatological problems among common symptoms reported by people living nearby gas facilities in Pennsylvania. Ferrar et al.[5] documented dermal, digestive, upper respiratory and central nervous system symptoms as being the most common health impacts in people living close to unconventional gas development in Pennsylvania. The human health symptoms reported in these studies are consistent with our findings. Ferrar et al.[5] followed cases longitudinally over 19–22 months and found that reported symptoms increased in the majority of organ systems. However, case participants who had moved away from their communities between the first and second interviews were removed from the sample population in the Ferrar study. As these types of cases were not removed from our study, and because we accounted for changes in industrial activity over time, this may partially account for the different outcomes.

The major finding of this study is that health impacts dropped for families and animals moving out of intensively drilled areas or remaining in areas where drilling activity decreased. In the cases of families that remained in the same area and for which drilling activity either remained the same or increased, no change in health impacts was observed. This is particularly interesting because, in some of the cases, the initial interview was done after an incident, such as a wastewater leak from an impoundment.

The distribution of symptoms was unchanged for humans and companion animals, but was significantly changed for food animals. Reports of reproductive failure fell, while respiratory issues and stunted growth were reported more often. Although this may be a consequence of the selection of cases, it represents an interesting change. In some of the cases involving food animals, the initial interview was conducted following an incident such as the leak of wastewater into a pasture or into the source of drinking water for the herd. These incidents were strongly associated with the failure to breed. In the second interview, the contaminated areas were made inaccessible or remediated; in one case, the herd was provided an alternative source of water.

The respiratory and growth issues identified in the second interview were more likely associated with lingering effects of the first exposure or another exposure pathway, such as air contamination. Two epidemiological studies of human births[10, 11] are consistent with the stunted growth seen here in food animals. Both show a decrease in birth weight and low APGAR scores were associated with proximity to shale gas operations. The effects were observed up to 3 miles from the nearest well, suggesting air as the most likely route of exposure. The finding that the results were not different for mothers using private water supplies and those using public water sources supports the supposition that air may be the most likely source of exposure.[11]


Because of the complexities of multiple exposure pathways, multiple possible chemical toxicants, multiple sources of contamination, and changes in toxicant concentration over time, direct measurement of chemical contamination is problematic. For these reasons, studying the health effects of humans and animals living near gas and oil drilling and processing facilities provides a more direct measure not only because health consequences represent the actual variables of interest but also because they reflect the integration of toxic insult over time and multiple exposure pathways. The work reported here represents only the first stages in the epidemiological analysis of the health effects of gas and oil drilling. Both this study and our previous work[1] support the need for further analytical measures of the prevalence of health problems among humans, companion animals and food animals in areas of gas and oil extraction.

Human exposure to unconventional natural gas development: A public health demonstration of periodic high exposure to chemical mixtures in ambient air by David R. BrownCelia Lewis & Beth I. Weinberger

Pages 460-472

View full text


Directional drilling and hydraulic fracturing of shale gas and oil bring industrial activity into close proximity to residences, schools, daycare centers and places where people spend their time. Multiple gas production sources can be sited near residences. Health care providers evaluating patient health need to know the chemicals present, the emissions from different sites and the intensity and frequency of the exposures. This research describes a hypothetical case study designed to provide a basic model that demonstrates the direct effect of weather on exposure patterns of particulate matter smaller than 2.5 microns (PM2.5) and volatile organic chemicals (VOCs). Because emissions from unconventional natural gas development (UNGD) sites are variable, a short term exposure profile is proposed that determines 6-hour assessments of emissions estimates, a time scale needed to assist physicians in the evaluation of individual exposures. The hypothetical case is based on observed conditions in shale gas development in Washington County, Pennsylvania, and on estimated emissions from facilities during gas development and production. An air exposure screening model was applied to determine the ambient concentration of VOCs and PM2.5 at different 6-hour periods of the day and night. Hourly wind speed, wind direction and cloud cover data from Pittsburgh International Airport were used to calculate the expected exposures. Fourteen months of daily observations were modeled. Higher than yearly average source terms were used to predict health impacts at periods when emissions are high. The frequency and intensity of exposures to PM2.5 and VOCs at a residence surrounded by three UNGD facilities was determined. The findings show that peak PM2.5 and VOC exposures occurred 83 times over the course of 14 months of well development. Among the stages of well development, the drilling, flaring and finishing, and gas production stages produced higher intensity exposures than the hydraulic fracturing stage. [And that’s why the US EPA gave industry a big gift and punted those stages from their frac study] Over one year, compressor station emissions created 118 peak exposure levels and a gas processing plant produced 99 peak exposures over one year. The screening model identified the periods during the day and the specific weather conditions when the highest potential exposures would occur. The periodicity of occurrence of extreme exposures is similar to the episodic nature of the health complaints reported in Washington County and in the literature. This study demonstrates the need to determine the aggregate quantitative impact on health when multiple facilities are placed near residences, schools, daycare centers and other locations where people are present. It shows that understanding the influence of air stability and wind direction is essential to exposure assessment at the residential level. The model can be applied to other emissions and similar sites. Profiles such as this will assist health providers in understanding the frequency and intensity of the human exposures when diagnosing and treating patients living near unconventional natural gas development.


… The short, and even not-so-short, distances between unconventional natural gas development (UNGD) and everyday human activity allow for emissions from natural gas extraction, processing, and transport to reach individuals in the areas where UNGD activities take place.

The emissions that occur within several miles of residences (sometimes less than 500 feet) pose challenges for health care providers seeing patients from these areas. Health care providers (as well as patients themselves) have very little information on the contents of UNGD emissions and the concentration of toxics that could be reaching people where they live or work. Currently patients go to physicians with health concerns but are unable to identify chemical or particulate exposures, if they exist. Physicians unfortunately often find themselves with similarly imprecise exposure conceptualizations. Guidance provided by public agencies is often insufficient to protect the health of individuals, yet, there is an increasing amount of data collected on UNGD emissions; and there is existing research on the toxicological and clinical effects of some substances emitted by UNGD activities.

In the present study we consider estimates of emissions from well pads, compressor stations and processing plants to gauge individuals’ possible exposures and the health risks those exposures pose. This is necessary because much of the publicly accessible emissions data has been collected to provide average exposures over a lengthy period of time and because the data collection is intended to document compliance with regional air quality standards. To assess health impacts, it is, therefore, necessary to look at human exposures in the short term. What matters from a health perspective is the content and intensity of exposures at the individual level. The critical questions are: What is a person, in a given household, exposed to? How high do those exposures climb? How often is that resident exposed to these high levels? What happens physiologically when a particular toxic comes in contact with the body? This set of questions pertains to individuals living in shale gas regions across the country and is at the core of the public health problem of UNGD.

The objective of this article is to provide a structure for understanding patterns of air exposures resulting from shale gas activity. Our aim is to provide a method for understanding the fluctuations and degree of predictability of peaks in exposure. It is not to achieve precise emissions estimates. Current emission data is too sparce to do that level of modeling. To illustrate the patterns, we present a case study of a hypothetical residence located in southwestern Pennsylvania. The residence is situated near a well pad, a compressor station and a processing plant.

The Southwest Pennsylvania Environmental Health Project’s ground-level experience with individuals, along with continual assessment of the literature on UNGD emissions, leads us to propose several essential criteria for evaluating individual exposures. These are: 1) proximity of well pads, compressor stations, production facilities or other operations associated with UNGD; 2) varied stages of operations occurring at the just the well pads; 3) the presence of chemical mixtures in air emissions; 4) the role of weather in dispersion of air pollutants; 5) the resulting chemical composition and concentrations exposing the individual; 6) the frequency and duration of exposures.

[MUST READ:] The present study demonstrates that households near UNGD sites are subjected to variable particulate and chemical air exposures that may reach potentially dangerous levels. Furthermore, it broadens the concern to the whole lifetime of shale gas development rather than primarily focusing on hydraulic fracturing as the predominant polluter. [Another reason why the US EPA dropped nearly everything in the whole lifetime of development from their frac study] but fracing from their Hydraulic fracturing itself occurs over a matter of weeks, while compressor stations and gas processing plants, also located near people’s homes, pollute 24 hours a day for as long as gas is flowing through the pipeline. These parts of the process produce significant air contaminants and deserve more attention than they have received thus far.

Documented air emissions from UNGD sources

As a group, emissions from one part of the process differ from those produced by another. The particular mix of emissions from a processing plant is different in kind and quantity, from that of a compressor station, which is different from emissions produced by the drilling of a well. That said, there are certain contaminants that are common across many, if not all, parts of the process; two of the most notable being VOCs and particulate matter.

Six air pollutants whose regional ambient air levels are regulated by the Environmental Protection Agency (EPA), are generally found at UNGD sties and are frequently discussed in the literature and identified by public agencies. These are: ozone, particulate matter (PM), carbon monoxide (CO), nitric oxides (NOx), sulfur oxides (SOx), and lead. Also frequently discussed in the emerging literature on UNGD are volatile organic compounds (VOCs) which include aromatic hydrocarbons, halogenated compounds, aldehydes, alcohols, and glycols.[2-4] VOCs are released into the atmosphere during the production and processing of natural gas and as a component of diesel and exhaust.[5] They also are released from gasoline, solvents, paints and other industrial and domestic products.

The Pennsylvania Department of Environmental Protection (PA DEP) inventory of emissions from natural gas facilities includes CO, NOx, PM10 (particulate matter less than 10 microns), PM2.5 (less than 2.5 microns), SOx, the VOCs, Benzene, Ethyl Benzene, Formaldehyde, n-Hexane, Toluene, Xylenes (isomers and mixture), and 2,2,4-Trimethylpentane.[6] In Washington County, Pennsylvania, the PA Department of Environmental Protection (PA DEP) has collected data on 214 natural gas facilities. The highest levels of emissions reported were of benzene, PM2.5, NOx, formaldehyde, trimethyl pentene, and ethyl benzene.[7]Additionally, a study conducted for the City of Fort Worth, Texas found acetaldehyde, butadiene 1,3, carbon disulfide, carbon tetrachloride, and tetrachloroethylene.[8] The Texas Commission on Environmental Quality collects data on NOx, VOCs and HAPs (hazardous air pollutants regulated based on emissions rather than regional air levels).[9] There are many other known, suspected, and as yet unknown air emissions from UNGD.[1,8,10,11]

Fluctuations in emissions and ambient air dispersal

Well pad emissions vary in content and concentration over time. In the lead up to a producing well, different activities occur: drilling, hydraulic fracturing, flowback, flaring and, finishing. In contrast other UNGD facilities operate in a more uniform way over time (such as compressor stations and processing plants) but still emissions measured nearby also vary (see Findings section). In addition to differing releases of contaminants, emissions disperse from their sources in varied patterns due to weather and atmospheric conditions. Characterizing these variations– their intensity, frequency, and duration – is critically important from a public health perspective. Little attention has been paid to these fluctuations, particularly the high spikes in exposures.

Three short-term air reports from the PA DEP provide a set of compounds found at well sites, impoundment ponds and compressor stations.[12-14] The PA DEP developed its list of air contaminants after consulting with the Texas Commission on Environmental Quality, New York Department of Environmental Conservation, data from research in Dish, TX, the Federal Register, and TERC.[12]As seen in Table 1, measurement data reveal the variation in emissions even from a single source over only three days. Such variability makes accurate exposure estimates difficult. An examination of the compressor station measurements below also illustrates the seriousness of the problem posed by averaging out emissions data.

Table 1 illustrates the information lost when combining and averaging emissions over time. Looking at ethylbenzene, for instance, we see that its detection varies from zero to over 20,000 ug m−3 in just 3 days.

Residential VOC exposures

A small number of studies have been published documenting UNGD-generated air exposures near residences. McKenzie et al.,[15,16] analyzing data from Garfield County, CO, documented concentrations of benzene, ethylbenzene, toluene, and m-xylene/p-xylene 2.7, 4.5, 4.3, and 9 times higher within 0.8 km of sites near well completion activities than were concentrations further out. Also in Garfield County, Colorado, Colborn et al.[16] sampled air outside a residence 1.1 km from UNGD in 2010 and 2011 (and where there was no other nearby industrial activity). Detected in 60% to 100% of the samples were VOCs including methane, ethane, propane, toluene, isopentane, n-butane, isobutene, acetone, n-pentane, n-hexane, methylcyclohexane, methylene chloride, m/p-xylenes: and carbonyls, including formaldehyde, acetaldehyde, crotonaldehyde, 2-butanone (MEK) and butyraldehyde.

Researchers working with Earthworks sampled air near residences in nine counties in Pennsylvania during 2011 and 2012. For households between 0.1 km and 8 km from gas facilities 94% of the samples that were tested for 2-butanone detected it; 88% of those tested for acetone and 79% of those tested for chloromethane detected it. Also frequently but not as consistently found were 1,1,2-Trichloro-1,2,2-trifluoroethane, carbon tetrachloride and trichlorofluoromethane.[17]

In 2009, Wolf Eagle Environmental, a consulting firm working for the town of Dish, Texas, sampled air on seven residential properties near compressor stations. Chemicals identified in the samples drawn included a number that were found above Texas’s Effective Screening Levels (levels which cause concern for health effects). These included benzene, dimethyl disulfide, naphthalene, m & p xylenes, carbonyl sulfide, carbon disulfide, methyl pyridine, and dimethyl pyridine.[11]

Health problems identified in the literature

The onset of the acute actions of VOCs and PM2.5 can be very brief, within days, hours or minutes.[18] Many of the studies listed below find illnesses reported that appear to be short term but recurring (Table 2). For instance, burning eyes and throat irritation were found in the research of Bamberger,[19] Steinzor et al.,[17] and Subra.[20,21] Episodic nausea was reported by residents in studies by Ferrar et al.,[22] Subra,[20] and Bamberger and Oswald.[19] Rabinowitz et al. documents reports of dermatologic and upper respiratory symptoms close to well sites.[23]

Materials and methods
Development of the case study

A model is presented for a hypothetical residence in southwest Pennsylvania. The residence has one well pad with five wells 1 km to the west, a compressor station 2 km to the south and a processing station 5 km to the north. This “typical” scenario is based on a dataset of 276 households in Washington County, Pennsylvania.[28] It includes two common UNGD facilities – a well pad with multiple wells and a compressor station. We chose to include a processing plant at the furthest distance (5 km) because they are less common yet large enough to pose potentially significant health risks.

EHP exposure model

Considering a hypothetical residence with three different sources at 1 km, 2 km and 5 km, we model the movement and dilution of emissions from each point source to the residence over a period of 14 months. We applied weather conditions reported from the Pittsburgh International Airport from February 2011 through March 2012. The rates of dilution, based on known weather effects and distance from the source, are calculated in 6-h increments. Six-h increments capture the four time periods that are generally responsive to diurnal weather-based dilution patterns. The 6-h increments are designated Night: 12 midnight – 6:00 am; Morning: 6:00 am – 12 noon; Afternoon: 12 noon – 6:00 pm; Evening: 6:00 pm – 12 midnight. The short time intervals also reflect our interest in capturing the short time periods in which onset of health reactions can occur.

Calculation of weather/diurnal effects

Cloud cover, wind speed, wind direction, and portion of the day (day or night) are factored into the model and affect the dilution of the contaminants and the intensity of exposures at different distances. Pasquill categorized these atmospheric variations into six “stability classes” A, B, C, D, E and F, with class A being the most unstable or most turbulent class, and class F the most stable or least turbulent class (Table 3).[29] The more stable the atmosphere, the less likely emissions will mix and dilute with the ambient air and the greater the risk that higher ambient concentrations will lead to exposure at the residence.

One stability class is assigned to each 6-h period. This determines the mixing of the pollutant in the air column at the relevant distance between a source and the residence. For the well pad, which is 1km west of the residence, days with winds from the west or with calm conditions are expected to carry emissions toward the home. Winds from the south and north are relevant for emissions moving from the compressor and processing station, respectively. Winds reported as zero at the airport are calculated at 0.2 mph since air movement is always present. Further information on the EHP exposure model can be found on the Southwest Pennsylvania Environmental Health Project website.[30]

Results using EHP estimated emissions source terms
Well pad development

Compressor station and processing plant

Unlike well pad development, compressor station emissions are assumed to be relatively constant over a 1-year period, operating 24 h a day and seven days a week. The varied patterns of 6-h exposures to VOCs at the residence 2 km from the compressor station [Encana has two compressors about 900 metres north of the Ernst home, many more within a few kilometres and large processing plants, including sour, in the area] are shown in Figures 6 and 7Figure 6 shows the variability in exposures experienced over the period of one year (2011) and Figure 7 shows the results for a representative month (May 2011) to provide a closer look at the day-to-day variability. The maximum peak exposure value for the compressor station was 169 ug m−3. Low values are also found throughout the year.

2015 03 03 Compressor stn emissions graphs for 2011 by Brown et al wout title

Fig. 6. Changes in the modeled ambient air levels of VOCs from a compressor station over a year

[What are Encana’s compressor emissions peaks only 900 metres from Ernst’s home?]

Similar to compressor stations, processing plants are assumed to have relatively constant emissions, although there is variation depending on, among other things, the type of gas (wet vs. dry). We use a high estimate for VOCs to reflect an uncertainty factor we associate with the processing facility. The gas processing plants are known to have multiple, frequent, and large scale flaring. In addition, there are more opportunities for fugitive emissions over and above those at the smaller compressor stations. The source term we use for the processing plant is the most complicated and potentially problematic. See Appendix C for a full discussion of the reasoning behind our emissions estimate.

The varied patterns of 6-h exposures to VOCs at the residence 5 km from the processing station are shown in Figures 8 and 9. Although this source is further away than the compressor station, exposure values are higher, with maximum peaks reaching 450 ug m−3. These findings, along with those of the compressor station, show that even with relatively constant emissions from a source there will be high variability in the frequency, duration and intensity of exposures at a nearby residence. The results also indicate that processing station emissions will impact a broader geographic range than well pads or compressor stations.

2015 03 03 Plant emissions graphs for 2011 by Brown et al wout title

Fig. 8. Changes in the modeled ambient air levels of VOCs from a processing plant over a year

[What are we all breathing in Alberta, especially for those living in valleys, like at Rosebud, surrounded by processing stations and compressors? Headaches, nose bleeds anyone? Tummy upsets? Skin, eye irritations? Difficulty breathing? Problems with livestock? Cancer?]

Frequency of peaks

Examining frequency of peaks (two standard deviations above the mean for each stage), Table 6 shows that during the 15-day hydraulic fracturing stage, there would be two 6-h periods with peak exposures at the residence. From the compressor station there would be 118 6-h peak periods – or 708 h of peak exposures – over the 1-year period modeled. From the processing plant there would be 99 6-h peak periods – or 594 h. These findings suggest that the residence could experience as many as 300 6-hour peaks of VOC exposure over the course of the modeled 14-month period. They also indicate that average intensity over the course of a year is a poor measure for risks to individuals near facilities and operations. Table 7 summarizes peak exposures for PM2

Diurnal variation [Hold your breath, all night long]

Residents tend to be more at risk at night when they are also less likely to be aware of the exposures. At night there is usually less mixing within the air column than during the day. The two 6-h periods at night (6:00 pm – 12 midnight and 12 midnight – 6:00 am) tend to carry higher exposure values. For example, in May 2011 the average values of exposure from a producing well pad for evening, night, morning and afternoon periods were 51 ug m−3, 58 ug m−3, 12 ug m−3 and 10 ug m−3, respectively. This pattern indicates that residents may be most at risk at night when they are also less likely to be aware of the exposures.


… The study shows that it is necessary to consider all nearby sites and the activities at those sites. The effects from one site are compounded by those of another. By bringing together estimates of UNGD emissions, the timing of activities, and weather patterns over a year, a more plausible prediction about an individual’s exposures to airborne pollutants can be made.

Periods and patterns of peak exposures

The modeled data show that exposure levels increase most often during nighttime hours when there is usually less mixing within the air column. Residents appear to be most at risk at night when they are also less likely to be aware of the exposures. This is consistent with anecdotal reports from residents who often think that nighttime air is less polluted than daytime air. They are often inclined to open windows at night before going to bed. Poorer air quality at night, however, may in part explain why people complain of waking up feeling sick, but improve as the day goes on.[31]

VOC and PM exposures vary with the source
Well pad (Figs. 2–5)

Drilling stage emissions are characterized by frequent 6-h episodes of low to moderate VOC exposures and instances of extreme exposures. The hydraulic fracturing stage is similar but is less frequently intense. Flaring and finishing produce high level exposures which continue at lower levels during production. These profiles are consistent with residents’ reports of periodic odors and sensory and respiratory irritation. A patient near a well pad would have periods of low exposure some weeks, but higher, more dangerous exposures other weeks.

In contrast to well pads, compressor stations more consistently produce emissions. Thus, variability in exposures is largely, but not entirely, due to weather and air stability.

The gas processing plant, despite its being five kilometers north from the residence, produced exposures consistently higher than those produced by well development activities or the compressor station, which are closer. The plant has the largest toxic footprint of the three sites and poses the most danger to residents.

2014 03 12 NW of Calgary Cochrane Interpipeline Gas Plant Non-compliant Pollution Reported to AER

March 12, 2014: Cochrane Interpipeline Gas Plant NW of Calgary, Alberta

Physicians who understand the fundamental aspects of the route of exposures will be able to communicate risks or reassurances to the resident, explaining that he or she is not exposed to high levels all the time. Some days are better, some are worse. Those days that are ‘worse’ deserve attention and over time they are numerous.

Exposures occur from multiple sources at overlapping times

Figure 10 provides a 1-week snapshot of exposures at the hypothetical residence in September 2011. In the week featured the highest residential exposures are from the well pad during its flaring/finishing stage. As this occurs, however, the residence is also receiving lower but still significant emissions from the other two facilities.

2015 03 03 Cumulative, well site 1km away, compressor 2km away, plant 5 km away emissions graphs for 2011 by Brown et al wout title

Fig. 10. One week of estimated ambient air exposures from three UNGD sources during a 7-day period

Health implications of episodic exposures to shale emissions

It is important to consider the toxic actions of periodic exposures to high doses of these chemicals.

Effects from high exposures to VOCs

VOCs are a varied group of compounds which can range from having no known health effects to being highly toxic. Short-term exposure can cause eye and respiratory tract irritation, headaches, dizziness, visual disorders, fatigue, loss of coordination, allergic skin reaction, nausea, and memory impairment. Long-term effects include loss of coordination and damage to the liver, kidney, and central nervous system. Some VOCs, such as BTEX (benzene, toluene, ethylbenzene and xylene, which are often emitted together), have been detected near natural gas development and specifically noted by Wolf Eagle, McKenzie et al., Colborn et al., and Steinzor et al.[12,16-18] Acute exposures to high levels of BTEX have been associated with skin and sensory irritation, central nervous system depression, and negative effects on the respiratory system. The case for elevated risk of cancer from UNGD VOC exposure has been made by McKenzie et al.[15]

Mixtures increase the hazards

Mixtures of pollutants are a critically important topic in addressing the public health implications of UNGD. While this report has focused separately on two pollutants, in fact, a very large number of chemicals are released together. Moreover many of the chemicals have little or no tested health data – alone or in conjunction with others. In fact, medical reference values do not take the complex nature of the shale environment, the multiple emissions and interactions, into full consideration.[38] The shale gas industry is not alone in emitting multiple pollutants simultaneously, but this industry is unusual in doing so as close as 500 feet from residences. 

Children and pregnant women are vulnerable

Children and pregnant women are especially sensitive to pollution and are of high public health concern. Many studies confirm a range of adverse effects of air pollution on children’s lung function and respiratory symptoms, especially for asthmatics. Studies often point, specifically, to fine particles as having an association with respiratory symptoms.[39]

Research on PM2.5 suggests that in pregnant women, the high particulate highway pollution (which has many commonalities with shale gas pollution) “may provoke oxidative stress and inflammation, cause endocrine disruption, and impair oxygen transport across the placenta, all of which can potentially lead to or may be implicated in some low birth weight … and preterm births.” These are immediate consequences in infancy, but further on “low birth weight and preterm birth can affect health throughout childhood and in adulthood.”[40] Two studies on birth outcomes and UNGD exposures find correlations between exposures and risk to newborns. Hill found an association between proximity to wells and low birth weight, small for gestational age, and reduction in APGAR scores.[26] McKenzie et al. found an association between proximity and density of nearby wells and congenital heart defects and possibly neural tube defects.[27]


Reported health conditions in animals residing near natural gas wells in southwestern Pennsylvania by I. B. SlizovskiyL. A. ContiS. J. TrufanJ. S. ReifV. T. LamersM. H. StoweJ. Dziura & P. M. Rabinowitz

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Natural gas extraction activities, including the use of horizontal drilling and hydraulic fracturing, may pose potential health risks to both human and animal populations in close proximity to sites of extraction activity. Because animals may have increased exposure to contaminated water and air as well as increased susceptibility to contaminant exposures compared to nearby humans, animal disease events in communities living near natural gas extraction may provide “sentinel” information useful for human health risk assessment. Community health evaluations as well as health impact assessments (HIAs) of natural gas exploration should therefore consider the inclusion of animal health metrics in their assessment process. We report on a community environmental health survey conducted in an area of active natural gas drilling, which included the collection of health data on 2452 companion and backyard animals residing in 157 randomly-selected households of Washington County, Pennsylvania (USA). There were a total of 127 reported health conditions, most commonly among dogs. When reports from all animals were considered, there were no significant associations between reported health condition and household proximity to natural gas wells. When dogs were analyzed separately, we found an elevated risk of ‘any’ reported health condition in households less than 1km from the nearest gas well (OR = 3.2, 95% CI 1.07–9.7), with dermal conditions being the most common of canine disorders. While these results should be considered hypothesis generating and preliminary, they suggest value in ongoing assessments of pet dogs as well as other animals to better elucidate the health impacts of natural gas extraction on nearby communities.

Data inconsistencies from states with unconventional oil and gas activity by Samantha MaloneMatthew KelsoTed AuchKaren EdelsteinKyle Ferrar & Kirk Jalbert

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The quality and availability of unconventional oil and gas (O&G) data in the United States have never been compared methodically state-to-state. By conducting such an assessment, this study seeks to better understand private and publicly sourced data variability and to identify data availability gaps. We developed an exploratory data-grading tool – Data Accessibility and Usability Index (DAUI) – to guide the review of O&G data quality. Between July and October 2013, we requested, collected, and assessed 5 categories of unconventional O&G data (wells drilled, violations, production, waste, and Class II disposal wells) from 10 states with active drilling activity. We based our assessment on eight data quality parameters (accessibility, usability, point location, completeness, metadata, agency responsiveness, accuracy, and cost). Using the DAUI, two authors graded the 10 states and then averaged their scores. The average score received across all states, data categories, and parameters was 67.1 out of 100, largely insufficient for proper data transparency. By state, Pennsylvania received the highest average ( = 93.5) and ranked first in all but one data category. The lowest scoring state was Texas ( = 44) largely due to its policy of charging for certain data. This article discusses the various reasons for scores received, as well as methodological limitations of the assessment metrics. We argue that the significant variability of unconventional O&G data—and its availability to the public—is a barrier to regulatory and industry transparency. The lack of transparency also impacts public education and broader participation in industry governance. This study supports the need to develop a set of data best management practices (BMPs) for state regulatory agencies and the O&G industry, and suggests potential BMPs for this purpose.

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Flowback and produced wastewaters from unconventional hydraulic fracturing during oil and gas explorations typically brings to the surface Naturally Occurring Radioactive Materials (NORM), predominantly radioisotopes from the U238 and Th232 decay chains. Traditionally, radiological sampling are performed by sending collected small samples for laboratory tests either by radiochemical analysis or measurements by a high-resolution High-Purity Germanium (HPGe) gamma spectrometer. One of the main isotopes of concern is Ra226 which requires an extended 21-days quantification period to allow for full secular equilibrium to be established for the alpha counting of its progeny daughter Rn222. Field trials of a sodium iodide (NaI) scintillation detector offers a more economic solution for rapid screenings of radiological samples. To achieve the quantification accuracy, this gamma spectrometer must be efficiency calibrated with known standard sources prior to field deployments to analyze the radioactivity concentrations in hydraulic fracturing waste products.

Well water contamination in a rural community in southwestern Pennsylvania near unconventional shale gas extraction by Shyama K. AlawattegamaTetiana KondratyukRenee KrynockMatthew BrickerJennifer K. RutterDaniel J. Bain & John F. Stolz

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Reports of ground water contamination in a southwestern Pennsylvania community coincided with unconventional shale gas extraction activities that started late 2009. Residents participated in a survey and well water samples were collected and analyzed. Available pre-drill and post-drill water test results and legacy operations (e.g., gas and oil wells, coal mining) were reviewed. Fifty-six of the 143 respondents indicated changes in water quality or quantity while 63 respondents reported no issues. Color change (brown, black, or orange) was the most common (27 households). Well type, when known, was rotary or cable tool, and depths ranged from 19 to 274 m. Chloride, sulfate, nitrate, sodium, calcium, magnesium, iron, manganese and strontium were commonly found, with 25 households exceeding the secondary maximum contaminate level (SMCL) for manganese. Methane was detected in 14 of the 18 houses tested. The 26 wells tested for total coliforms (2 positives) and E. coli (1 positive) indicated that septic contamination was not a factor. Repeated sampling of two wells in close proximity (204 m) but drawing from different depths (32 m and 54 m), revealed temporal variability. Since 2009, 65 horizontal wells were drilled within a 4 km (2.5 mile) radius of the community, each well was stimulated on average with 3.5 million gal of fluids and 3.2 million lbs of proppant. PA DEP cited violations included an improperly plugged well and at least one failed well casing. This study underscores the need for thorough analyses of data, documentation of legacy activity, pre-drill testing, and long term monitoring.

[Refer also to:

March 4, 2015: Chief Marvin Yahey and Blueberry River First Nations files lawsuit against British Columbia Government, Believed to be first case based on cumulative impact of numerous developments, including hydraulic fracturing

March 3, 2015: More peer-reviewed studies indicating health harm from fracing and natural gas production, Dogs “found to be particularly sensitive, suggesting both health concerns for the animals and new ways to track pollution through animals’ exposures”

February 19, 2015: British Columbia’s Ministry Health withholding data, report of scientific research on how oil and gas operations are affecting human health in northeast communities; Refusing to release even under FOIP: “could be harmful to the financial interest of a public body”

2015 02 17: Cumulative frac harms: Who’s looking? Canada Water Network? Synergy group extraordinaire with Alberta Government Bev Yee on the Board who helped cover-up Encana fracing Rosebud’s drinking water aquifers?

2014 10 01: Why was a 2012 Health Canada Report, admitting significant health hazards and risks to groundwater and air from hydraulic fracturing, kept from the public?

2014 08 28: Environment Canada Keeping Nearly a Thousand Frac Chemicals Secret: Memo released through Access to Information Legislation

2013 10 24: Air Pollution and Cancer Spikes linked in Alberta; Alberta’s Oil Legacy: Bad Air and Rare Cancers, Sickening carcinogens now saturate Industrial Heartland, study finds ]

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