Environmental impact of fracking in the United States

Environmental impact of fracking in the United States has been an issue of public concern, and includes the contamination of ground and surface water, methane emissions,[1] air pollution, migration of gases and fracking chemicals and radionuclides to the surface, the potential mishandling of solid waste, drill cuttings, increased seismicity and associated effects on human and ecosystem health.

[4][5] A number of instances with groundwater contamination have been documented due to well casing failures and illegal disposal practices,[6] including confirmation of chemical, physical, and psychosocial hazards such as pregnancy and birth outcomes, migraine headaches, chronic rhinosinusitis, severe fatigue, asthma exacerbations, and psychological stress.

"Public exposure to the many chemicals involved in energy development is expected to increase over the next few years, with uncertain consequences" wrote science writer Valerie Brown in 2007.

[citation needed] In DISH, Texas, elevated levels of disulfides, benzene, xylenes and naphthalene have been detected in the air, emitted from compressor stations.

The rules would also reduce air toxins, which are known or suspected of causing cancer and other serious health effects, and emissions of methane, a potent greenhouse gas.

[20] In 2019, Robert W. Howarth concluded that rising shale-gas production in North America has contributed significantly to the recent increase in global atmospheric methane.

[2] Out of 2,500 hydraulic fracturing products, more than 650 contained known or possible human carcinogens regulated under the Safe Drinking Water Act or listed as hazardous air pollutants".

[41] The Ground Water Protection Council launched FracFocus.org, an online voluntary disclosure database for hydraulic fracturing fluids funded by oil and gas trade groups and the United States Department of Energy (DOE).

[47] However, by 2013, Dr. Robin Ikeda, Deputy Director of Noncommunicable Diseases, Injury and Environmental Health at the CDC testified to congress that EPA had documented contamination at several sites.

[48] Flowback is the portion of the injected fracturing fluid that flows back to the surface, along with oil, gas, and brine, during well commissioning, a process which typically takes a week, though durations vary.

[68] In California, Virginia, and Ohio there have been instances of illegal dumping of flowback, a precursor to possible contamination of local ground and surface water reservoirs.

[81][82] The Associated Press has reported that starting in 2011, the DEP strongly resisted providing the AP and other news organizations with information about complaints related to drilling.

In May 2013 the facility signed another agreement to not accept or discharge wastewater Marcellus Shale formations until it has installed technology to remove the radiation compounds, metals and salts.

[81] Despite this, in 2009 the Ridgway Borough's public sewage treatment plant, in Elk County, PA, facility was sent wastewater containing radium and other types of radiation at 275–780 times the drinking-water standard.

[81] The New York Times reporting has been criticized[100] and one science writer has taken issue with one instance of the newspaper's presentation and explanation of its calculations regarding dilution,[104] charging that a lack of context made the article's analysis uninformative.

[115] The injection of waste water from oil and gas operations, including from hydraulic fracturing, into saltwater disposal wells may cause bigger low-magnitude tremors, being registered up to 3.3 (Mw).

[119] Of greater concern are earthquakes associated with permitted Class II deep wastewater injection wells, many of which inject frac flowback and produced water from oil and gas wells.The USGS has reported earthquakes induced by disposal of produced water and hydraulic fracturing flowback into waste disposal wells in several locations.

[125] According to the USGS only a small fraction of roughly 40,000 waste fluid disposal wells for oil and gas operations in the United States have induced earthquakes that are large enough to be of concern to the public.

[130] A 2015 study concluded that recent earthquakes in central Oklahoma, which includes 5.7 magnitude quake, were triggered by injection of produced water from conventional oil reservoirs in the Hunton Group, and are unrelated to hydraulic fracturing.

[132] Several earthquakes in 2011, including a 4.0 magnitude tremor on New Year's Eve that hit Youngstown, Ohio, are likely linked to a disposal of hydraulic fracturing wastewater,[120] according to seismologists at Columbia University.

The following day, after the 4.0 quake, Ohio governor John Kasich ordered an indefinite halt to injection in three additional deep disposal wells in the vicinity.

[139] A 2019 study explores the long-term (> 30 years) flow and transport of fracturing fluids into overburden layers and groundwater aquifers through a leaky abandoned well.

Cancer, blood disorders, nervous system impairment, and respiratory issues have also been cited as potential complications of hydraulic fracturing fluid exposure.

A 2014 retrospective cohort study of 124,842 births between 1996–2009 in rural Colorado reported statistically significant odds of congenital heart disease, including neural tube defects, with resident exposure to hydraulic fracturing.

[161] The respirable crystalline silica are particles less than 10 microns (micrometers), which are small enough to enter the part of the lungs were oxygen and carbon dioxide gases are exchanged.

NIOSH set the recommend exposure limit (REL) for silica at a fixed value of 0.05 milligrams per cubic meter as a time-weighted average (TWA) for up to a ten-hour shift during a forty-hour workweek.

[161] Another control measure is using a silica substitute proppant such as sintered bauxite, ceramics, or resin-coated sand, however OSHA notes that the safety testing must be performed on these alternatives.

[165] The EPA report did find uncertainties in knowledge of how fracturing fluid migrates through rocks, and recommended that diesel fuel not be used as a component of fracturing fluid in coalbed methane walls due to its potential as a source of benzene contamination; in response, well service companies agreed to stop using diesel fuel in coalbed methane wells.

[170] However, the EPA also noted that the mechanisms assessed in the report were not considered "widespread" and that evaluation of identified cases rests on limiting factors that include "insufficient pre- and post-fracturing data on the quality of drinking water resources; the paucity of long-term systematic studies; the presence of other sources of contamination precluding a definitive link between hydraulic fracturing activities and an impact; and the inaccessibility of some information on hydraulic fracturing activities and potential impacts.

However, existing evidence suggests that road and bridge deterioration from overloading infrastructure be taken into consideration when evaluating the environmental and economic cost of the fracking process.