Below is a list of major scientific studies and expert assessments that confirm fracking is not an inherent threat to groundwater.

Proceedings of the National Academy of Sciences, Yale University (2015): Fracking has not contaminated drinking water in the Marcellus Shale.

• “There was no evidence of association with deeper brines or long-range migration of these compounds to the shallow aquifers. Encouragingly, drinking water sources affected by disclosed surface spills could be targeted for treatment and monitoring to protect public health.” (p. 5)
• “We have found no evidence for direct communication with shallow drinking water wells due to upward migration from shale horizons.  This result is encouraging, because it implies there is some degree of temporal and spatial separation between injected fluids and drinking water supply.” (p.5)

U.S. Environmental Protection Agency (2015): No evidence of widespread water contamination from fracking.

• “[H]ydraulic fracturing activities have not led to widespread, systematic impacts to drinking water resources.”

U.S. District Court, Wyoming (2015): Experts have confirmed no water contamination from fracking.

• “[E]xperts and government regulators have repeatedly acknowledged a lack of evidence linking the hydraulic fracturing process to groundwater contamination.” (p. 26)

Syracuse University (2015): No evidence of fracking contaminating groundwater in heavily drilled areas of Pennsylvania, West Virginia, and Ohio.

• “We see no broad changes in variability of chemical quality in this large dataset to suggest any unusual salinization caused by possible release of produced waters from oil and gas operations, even after thousands of gas wells have been drilled among tens of thousands of domestic wells within the two areas studied.” (Executive Summary)

California Council on Science & Technology (2015): Fracking has not caused groundwater contamination in California.

• “We found no documented instances of hydraulic fracturing or acid stimulations directly causing groundwater contamination in California.” (p. 52)
• “The study found no releases of hazardous hydraulic fracturing chemicals to surface waters in California and no direct impacts to fish or wildlife.” (p. 35)

Stanford University (2015): No evidence of fracking fluids leaking up into drinking water aquifers.

• “Using innovative techniques such as isotopic ‘tracer’ compounds that distinguish the source of chemicals in well water, Jackson has not found evidence that frack water contaminants seep upward to drinking-water aquifers from deep underground.” (from press release)

U.S. Geological Survey (2014): No water contamination from fracking in West Virginia.

• “The comparison of groundwater data from this study with historical data found no significant difference for any of the constituents examined and therefore warrant no further discussion.” (p. 47)

Duke University, U.S. Geological Survey (2013): Fracking had no effect on groundwater wells in Arkansas.

• “Although preproduction water-quality data were lacking for the wells sampled for this study, geochemical data presented a well-defined pattern of geochemical evolution based on natural rock-water and microbially mediated processes, strongly suggesting that the resulting water quality is derived from these natural processes with no effects from gas-production activities.” (p. 28)

Gradient (2013): There is “no scientific basis” for the claim that fracking fluids will contaminate water aquifers.

• “Overall, there is no scientific basis for significant upward migration of HF fluid or brine from formations in sedimentary basins. Even if upward migration from a target formation to potable aquifer were hypothetically possible, the rate of migration would be extremely slow and the resulting dilution of the fluids would be very large…Given the overall implausibility and very high dilution factor, this exposure pathway does not pose a threat to drinking water resources.” (p. 4)

University of Michigan – Technology Report (2013): Water contamination from fracking has never “reliably” been shown to have occurred.

• “The often-postulated percolation upward of fracking water used in deep, long lateral well extensions to contaminate drinking water aquifers near the surface through the intervening impermeable rock formations is highly unlikely and has never reliably been shown to have occurred.” (p. 13)

University of Michigan – Public Health Report (2013): No reports of contamination from fracking in eight states.

• The authors of this report also met with officials from eight States (Arkansas, Colorado, Louisiana, North Dakota, Ohio, Oklahoma, Pennsylvania, and Texas) and determined that, based on state investigations, no report of groundwater contamination in these states was associated with hydraulic fracturing.” (p. 19)

Cardno Entrix (2012): Fracking has not caused groundwater contamination in Los Angeles.

• “Routine tests by the water purveyor show the community’s water supply meets drinking water standards, including the period of high-rate gravel packs and conventional hydraulic fracturing, as well as the first high-volume hydraulic fracture in September 2011… Before-and-after monitoring of groundwater quality in monitor wells did not show impacts from high-volume hydraulic fracturing and high-rate gravel packing.” (p. 3)

U.S. Government Accountability Office (2012):  The fracking process has not been identified as a cause of groundwater contamination.

• “[R]egulatory officials we met with from eight states – Arkansas, Colorado, Louisiana, North Dakota, Ohio, Oklahoma, Pennsylvania, and Texas – told us that, based on state investigations, the hydraulic fracturing process has not been identified as a cause of groundwater contamination within their states.” (p. 49)

Ground Water Protection Council (2011): Texas and Ohio have never had a documented occurrence of fracking contaminating groundwater.

• “Neither state [Ohio and Texas] has documented a single occurrence of groundwater pollution during the site preparation or well stimulation phase of operations.” (p.3)
• “In recent years, the national debate on natural gas E&P has been focused nearly exclusively on a single, brief, yet essential activity, hydraulic fracturing. Neither state has identified hydraulic fracturing as the cause of a single documented groundwater contamination incident.” (p. 102)

The Center for Rural Pennsylvania (2011): Gas drilling in the Marcellus Shale has not contaminated nearby water wells.

• “In this study, statistical analyses of post-drilling versus pre-drilling water chemistry did not suggest major influences from gas well drilling or hydrofracturing (fracking) on nearby water wells, when considering changes in potential pollutants that are most prominent in drilling waste fluids.” (p. 4)

N.Y. Revised Draft Supplemental Generic Environmental Impact Statement (2011): Groundwater contamination has not occurred as a result of hydraulic fracturing.

• “A supporting study for this dSGEIS concludes that it is highly unlikely that groundwater contamination would occur by fluids escaping from the wellbore for hydraulic fracturing. The 2009 dSGEIS further observes that regulatory officials from 15 states recently testified that groundwater contamination as a result of the hydraulic fracturing process in the tight formation itself has not occurred.” (p. 11)

Massachusetts Institute of Technology (2010): Risk of water contamination is low due to distance between groundwater and where fracking occurs.

• “The protection of freshwater aquifers from fracture fluids has been a primary objective of oil and gas field regulation for many years. As indicated in Table 2.2, there is substantial vertical separation between the freshwater aquifers and the fracture zones in the major shale plays. The shallow layers are protected from injected fluid by a number of layers of casing and cement — and as a practical matter fracturing operations cannot proceed if these layers of protection are not fully functional. Good oil-field practice and existing legislation should be sufficient to manage this risk.” (p. 15)