Ever since Josh Fox's documentary film Gasland startled viewers with its scenes of flammable tap water, concerns about groundwater contamination have fueled the community-level opposition to hydraulic fracturing. While water contamination continues to be a serious concern when it comes to fracking, a slew of scientific and government reports published in recent years points to perhaps a more immediate environmental threat: unsustainable groundwater and surface water withdrawals.
Scientists have long understood that fracking comes with a range of environmental risks. A 2014 study appearing in Environmental Toxicology and Chemistry concluded that the closer an ecosystem is to a fracking site, "the higher the risk of that ecosystem being impacted by the operation." The scientists further confirmed that oil and gas field infrastructure also uses significant amounts of water. "These operations may result in increased erosion and sedimentation," the study stated, as well as "increased risk to aquatic ecosystems from chemical spills or runoff, habitat fragmentation, loss of stream riparian zones, altered biogeochemical cycling, and reduction of available surface and hyporheic water volumes because of withdrawal-induced lowering of local groundwater levels."
In addition to habitat fragmentation and the risk of pollution, diminished flows in rivers and streams are one of the concerns that researchers outline in a study published in Frontiers in Ecology and the Environment. One of the study's authors, Kimberly Terrell told Earth Island Journal that freshwater withdrawal and stream siltation from fracking activities has lasting effects on aquatic ecosystems. "In the shale areas in the eastern US there is tremendous aquatic diversity," Terrell says. "However, only 21 percent of streams are healthy. The vast majority are not in good biological condition. On top of that, we have drained over 50 percent of our wetlands in the US."
As early as 2009, the Bureau of Economic Geology (BEG) at the University of Texas at Austin was already noticing an increase in water use for hydraulic fracturing in the Barnet Shale. Researchers concluded that hydraulic fracturing used an average of 2,400 gallons of water per foot of drilled hole, which equaled an average of 3 million gallons per horizontal well versus 1.2 million gallons for a conventional vertical well. (Some wells are more than a mile deep.) In other words, hydraulic fracturing used more than twice as much water. The BEG goes on to say: "Overall, frac ground water use does not make up a large fraction of the total ground water use, only a few percent, but could locally create nuisance as this fraction can be higher for some counties and much higher locally." Such local "nuisances" have already occurred. For example, in 2013 Barnhart Texas had to truck freshwater into the city when the combination of drought and fracking-related water withdrawals dried up local water wells.
A US Geological Survey study published earlier this year in the Water Resource Research journal found that, between 2011 to 2014, the average fracked well in the US requires about 4 million gallons of water. According to the study, significant water usage occurred in these formations: Eagle Ford and Haynesville-Bossier (Gulf Coast Basins), Barnett (Bend Arch-Ft. Worth Basin), Fayetteville (Arkoma Basin), Woodford (Anadarko and Arkoma Basins), Tuscaloosa (Gulf Coast Basins), and the Marcellus and Utica (Appalachian Basin). According to the study authors: "In 52 out of the 57 watersheds with the highest average hydraulic fracturing water volumes above 15,000 m3 per well, over 90 percent of wells were horizontally drilled." The researchers go on to say that horizontal drilling and hydraulic fracturing methods usually – but not always – use more water than conventional drilling.
Other federal agencies have echoed the USGS findings. In June the Environmental Protection Agency completed the Executive Summary of its draft Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources and found that the biggest impact on drinking water sources was the quantity of water withdrawals. While these finding are not finalized – nor are they considered agency policy – the draft document does offer strong warning about the water use. "Ground water withdrawals exceeding natural recharge rates decrease water storage in aquifers, potentially mobilizing contaminants or allowing the infiltration of lower quality water from the land surface or adjacent formations. … Withdrawals could also decrease ground water discharge to streams, potentially affecting surface water quality."
Although oil and gas companies sometimes promise to repair any damaged areas and return landscapes and waterways to close to their pre-drilling conditions, often the cleanup burden is borne by municipal, county, and state governments. In its report, Who Pays the Cost of Fracking, the Environmental Research and Policy Center call for drilling contractors to put up financial assurances prior to beginning exploration so that the environment will be restored after drilling and production is completed. "By holding operators fully accountable," the group says in its report, "strong financial assurance requirements deter some of the riskiest practices and ensure that the industry, rather than the public, bears the brunt of the costs." One such example of this burden has been seen continually for over 5 years with the saga of the BP Spill in the Gulf Coast.
There is also some good news. As a recent Governmental Accountability Office report, Water in the Energy Sector found, due to water restraints from drought and regulation, some companies are using their water more efficiently, "for example, by treating produced water for recycle and reuse–as an important part of their overall strategy to reduce cost, improve operational efficiency, and reduce the demand for freshwater." As the price of oil continues to plummet, the attractiveness of unconventional drilling also declines. Less drilling means less water withdrawals. And that will give streams, rivers, and aquifers a chance to recharge themselves.