How does America's groundwater become polluted and what are the sources of pollution that goes into the groundwater? How important is unpolluted groundwater to the sustainability of communities? Also, what are the solutions for this pollution of the groundwater? These issues and others will be reviewed in this paper.
According to William M. Alley, writing in the peer-reviewed journal Environment, groundwater exists "…almost everywhere beneath the land surface" and it plays a "crucial role in sustaining streamflow between precipitation events" and in particular during "protracted dry periods" (Alley, 2006, p. 16). Alley explains that about 85 billion gallons of groundwater are "withdrawn daily," and upwards of ninety percent of that water is used for "…irrigation, public supply (deliveries to homes businesses, industry) and self-supplied industrial use" (Alley, 16). Of those 85 billion gallons withdrawn from groundwater sources daily, nearly two-thirds is used for irrigation, Alley explains. Also, groundwater provides about half of the drinking water needed by U.S. communities, and moreover, there is a problem with groundwater in that information on its use is "…spotty and often inaccurate within the United States" (Alley, 17). Laws that regulate the use of groundwater "…vary significantly from state to state and from one water-use category to another…" (Alley, 17).
Sources of Groundwater Pollution
What is known about groundwater however is that it can become contaminated with pollutants, including the use of pesticides. The United States Geological Survey reports that the United States is the "…largest producer of food products in the world," and one of the main reasons that the U.S. can claim that title is because of the use of chemicals like pesticides to "…control the insects, weeds, and other organisms that attack food crops" (USGS). But there is a cost that is associated with the heavy use of pesticides, and in fact "..,.pesticide contamination of groundwater" has national implications because, as mentioned earlier in this paper, about half of the nation uses groundwater for drinking purposes (USGS, p. 1). In the agricultural areas where most crops are grown -- and hence, where pesticides are most often used -- about "…95% of that population relies upon ground water for drinking water," the USGS explains.
Thirty or so years ago it was believed that the soil acted as "…a protective filter that stopped pesticides from reaching groundwater," but recent studies prove that is not the case. In fact pesticides do reach groundwater aquifers from the use of pesticides in crops above, they do reach aquifers when contaminate surface water seeps down through the soil, where there are "accidental spills and leaks" or "improper disposal" -- and even through "injection waste materials into wells," the USGS continues. The polluting chemicals from pesticides may not reach groundwater sources for years (there is an ongoing study of this problem), but because "many hundreds of these compounds" are in use, the resulting danger to drinking water is of great concern to communities.
Hydraulic Fracturing or Fracking
Pesticides are not the only source of pollution for groundwater resources. The USGS explains that there is "…an increasing public concern about the effects of energy production on surface-water and groundwater quality" (USGS, 2012). The concerns are raised because the system of "hydraulic fracturing" is being used more frequently by energy companies as they search for oil and gas. Part of the system of hydraulic fracturing calls for horizontal drilling in "los permeability formations," the USGS continues. In the first place, oil drilling companies can contribute pollution to groundwater from the surface as well as below ground. At the drill site (or production facility) there can be "…leaks from pits or tanks, chemical spills, and discharge of wastewater," all of which can contaminate groundwater quality (USGS, p. 1). And leaks due to hydraulic fracturing, from "failed casing seals, pipeline breaks, abandoned wells, deep-well disposal of flowback or produced wastewater," all can pollute groundwater resources (USGS).
A Discussion of a Contemporary Issue -- Abandoned Oil and Gas Wells
Some twelve million holes have been drilled into the ground in the United States over the past 150 years, in search of gas and oil (Kusnetz, et al., 2011). Many of those wells (holes) have been abandoned, but they have nonetheless contributed to the pollution of drinking water sources in Fort Knox, Kentucky, and have leaked oil into water well in Michigan and Ohio, Kusnetz writes in the Scientific American. Other leaking wells that contaminate water sources underground have been located in Texas, Colorado, New York and in other states as well, Kusnetz explains. But there are many more that need to be plugged up because gas and oil from unattended wells is a source of pollution for aquifers, Kusnetz asserts. Up to 60,000 existing wells that need to be plugged, the author continues; some are plugged but they are not adequately plugged because they were plugged with "stumps, rocks, or nothing at all," Kusnetz explains (1).
There are myriad examples of unplugged, abandoned oil and gas wells, any or all of which can pollute groundwater sources that communities rely on for drinking water. In New York State, according to Kusnetz, there are about 40,000 "deteriorating wells" and only about 125 have been safely plugged up. In Kentucky, over twenty years about 4,000 oil and gas wells have been safely plugged but that leaves 13,000 more to be plugged. In Texas, Kusnetz continues, some 30,000 wells have been plugged up since 1984, and that leaves 10,000 abandoned wells still open and capable of contaminating groundwater sources (p. 2).
In 2010, oil and gas companies drilled an estimated 45,000 new well throughout the United States, Kusnetz explains. Even if "a small fraction of those well is eventually abandoned, states will be left with the bill," the author predicts (p. 2). In order to protect the public from companies that drill for oil, extract what they can and move on, abandoning the well, many states require energy companies to "…post bonds before they begin drilling their wells," Kusnetz goes on. However, the bonds are "often so low that it can be more economical for a company to forfeit its bond rather than plug its wells"; in Pennsylvania, for example, a $25,000 bond can cover "…hundreds of wells" so one can see how an oil company might just forfeit the bond and move on it the wells aren't producing sufficiently.
A Discussion of a Contemporary Issue -- Hydraulic Fracking / Fracturing
In order to reach oil and gas reserves that exist in subsurface fracture systems the energy companies are utilizing a strategy called fracking or hydraulic fracturing. Chemicals and other fluids are pumped into a geologic formation "…at high pressure," and when the pressure "exceeds the rock strength, the fluids open or enlarge fractures that can extend several hundred feet away from the well," according to the Environmental Protection Agency (EPA, 2012). A "propping agent is pumped into the fractures" so they won't close when the pressure is released, and the internal pressure causes the fluids pumped into the fractures to "rise to the surface where it may be stored in tanks or pits prior to disposal or recycling." These fluids are called flowback, and it is how companies get the oil out of the earth from a place where previously a well had been dug and most of the easily extracted oil was removed.
Is fracking a safe technology? The Natural Resources Defense Council (NRDC) supports federal regulation of hydraulic fracturing under the Safe Drinking Water Act based on data that the NRDC has gathered showing negative impacts to the environment. For example, in June, 2010, when hydraulic fracturing began on a gas well near Tracy Dahl's ranch in Las Animas County, Colorado, the ranch owner discovered "…approximately 500 gallons of grayish brown murky water where water had previously run clear for years" (Mall, 2011). The Dahl family provided documentation as to the safe and clean drinking water from their well going back many years, in an attempt to prove that fracking contaminated their water supply. But the Colorado Oil and Gas Conservation Commission told the family that their well (albeit it seemed certain to have been contaminated) "could not be tested for chemicals in the hydraulic fracturing fluid because there is insufficient information about the chemicals used" in the fracking project (Mall, p. 1).
Mall reports dozens of incidents in which water has been polluted by fracking. In Pennsylvania in 2009, the Zimmerman family in Washington County reported that their drinking water had been contaminated right after a fracking project (a project that was seeking natural gas through old wells owned by Atlas Energy). Testing proved that: a) the presence of mercury and selenium were above EPA limits; b) arsenic was 2,600 times "acceptable levels"; c) benzene was 44 times above limits; and d) naphthalene was five times above the federal limit (Mall, p. 2). In Texas, three families share an aquifer in Grandview, and following a fracking incident in a nearby gas well they reported "…strong odors in their…