Environmental Health – Hydraulic Fracturing

ENVIRONMENTAL HEALTH – HYDRAULIC FRACTURING

Fact Sheet

Environmental Impacts Associated with Hydraulic Fracturing
Toxic Chemicals and Radioactive Materials
The primary environmental impacts associated with hydraulic fracturing (fracking) result from the use of toxic chemicals during the fracking process and the subsequent release of additional toxic chemicals and radioactive materialsduring well production. Fracking fluid flowback – the fluid pumped out of the well and separated from oil and gas – not only contains the chemical additives used in the drilling process but also contains heavy metals, radioactive materials, volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) such as benzene, toluene, ethylbenzene and xylene (BTEX). Moreover, as the image to theright illustrates, numerous pathways exist throughout the fracking process for the release of these toxic and radioactive materials. As a result, the proper handling of the toxic and radioactive materials associated with fracking is essential throughout the lifecycle of a well.

Sources of Water Contamination
In response to concerns over drinking water contamination, Congress directed theEnvironmental Protection Agency (EPA) to conduct a study addressing the potential risks to drinking water associated with fracking.1 In the study, the EPA plans to research the full lifecycle of water during fracking. The potential impacts on water quality during the fracking process include:
Water Acquisition: Two to four million gallons of water is required to hydraulically fracture a single shale well.This “source
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water” is generally stored on site in tanks or surface impoundment pits. The removal of significant amounts of source water may impact water availability from local sources and adversely impact existing water quality.
On-site Chemical Mixing: An average well requiring 3 million gallons of water requires the injection of 15,000 to 60,000

gallons of chemical additives intothe well.3 Due to the large amount of chemical additives required, there is a risk of releasing to surface and ground water through on-site spills or leaks and a risk of releasing through chemical transportation accidents.

Well Injection: Shale formations commonly contain natural gas, carbon dioxide,

hydrogen sulfide, organic acids, BTEX, VOCs, trace elements (mercury, lead and arsenic) andnaturally occurring radioactive elements (radium, thorium and uranium).4 As a result, improper cementing or well casings risk the release of these substances into drinking water aquifers during the injection process. An interactive feature of the drilling process is available from the New York Times.5
Flowback and Produced Water: Following the fracking process, flowback containing

the initialfracking fluids as well as naturally occurring toxic and radioactive substances return to the surface. The flowback process continues for several weeks and, in the Marcellus Shale, only 1030 percent of the fluid is recovered.6 The recovered fluids are typically stored either in containment/evaporation pits or storage tanks. Here, improper well construction presents a risk of contamination todrinking water aquifers, while improper pit containment may result in contamination of surface waters.
Wastewater Treatment and Waste Disposal: The final stage of the lifecycle ends with

treatment or disposal of flowback waters. Following treatment, water may be reused or discharged into surface waters. Currently, publicly owned treatment facilities are not designed to treat fracking wastewaters,especially the radioactive materials. A recent New York Times article confirmed the presence of excessive levels of radium, uranium and benzene in rivers and streams due to improper treatment at facilities prior to discharging wastewater into surface waters.7

Sources of Air Contamination
Currently, the scope of EPA’s study is limited to water impacts. However, there are several sources of air...