This content is derived from the Physicians For Social Responsibility Compendium 3.0
Emerging science confirms that drilling and fracking inherently threaten groundwater and have contaminated drinking water sources. In Pennsylvania alone, more than 240 private drinking water wells have been contaminated or have dried up as the result of drilling and fracking operations over a seven-year period. A range of studies from across the United States presents irrefutable evidence that groundwater contamination occurs and is more likely to occur close to drilling sites. The nation’s 187,570 injection wells for disposal of fracking waste also pose demonstrable threats to drinking water aquifers. Municipal sewage treatment plants are not capable of treating fracking waste; disposal of fracking waste through them can encourage the formation of carcinogenic byproducts during chlorination. The disposal of fracking wastewater remains a problem without a safe, viable solution. Overall, the number of well blowouts (unintentional releases of pressurized gases and fluids), spills, and cases of surface water contamination from waste pits and other sources has steadily grown. Meanwhile, the gas industry’s use of “gag orders,” non-disclosure agreements, and settlements impede scientific study and stifle public awareness of the extent of these problems.
Fracking fluid that breaks up the Marcellus shale contains high concentrations of salt, boron, and chloride among up to 993 other known compounds. Two compounds are commonly used in fracking operations: naphthalene and 2-butoxyethanol. Exposure to 2-butoxyethanol has been linked to birth defects in animals. Naphthalene is a possible human carcinogen that is toxic to red blood cells and contributes to kidney and liver damage. A documented problem that can contaminate ground water is if fracking fluid is spilled, stored on the surface, or injected back into the ground. Of the 457 total known spills reported by the EPA, 300 reached an environmental receptor such as surface water or groundwater. Open disposal pits are now banned in most states.
It was once thought that most fracturing occurred much deeper than is commonly practiced. Shallow hydraulic fracturing can cause even greater risk than much deeper wells since groundwater is potentially vulnerable to chemical contamination through vertical faults and fissures, and via old and abandoned wells.
A typical gas or oil well that is horizontally fracked now requires between six and eight Olympic-sized swimming pools of water (up to 5 million gallons). The watersheds where the most water was consumed for hydraulic fracturing are mostly located in southern or southwestern states.
In drought stricken areas like California, farms have been allowed to irrigate with water that's been previously used in drilling operations. According to a University of Colorado Boulder research team, treatment of fracking wastewater must include aeration, precipitation, disinfection, a biological treatment to remove dissolved organic matter and reverse osmosis desalination in order for it to be appropriate for non-fracking uses, such as crop irrigation.
Drill pad locations are also a contributor to water contamination. Sites near streams and water sources are linked to greater sediment and chlorophyll resulting from surface land disturbances. Elevated methane levels have also been found in private water wells that is suspected to be the fault of defective well casings. Elevated levels of chloride, iron, barium, strontium, and manganese have also been found in private water wells. In some cases, concentrations exceeded health-based maximum contaminant levels.
A team of researchers from the USGS and Virginia Tech University established that petroleum-based hydocarbons can break down underground in ways that promote the leaching of naturally occurring arsenic into groundwater. Arsenic is a known human carcinogen that causes bladder, lung, and skin cancer.
A practice associated with tracking waste water infiltration is called "finger printing". Identifying chemicals used in fracking fluid can help researchers trace back to a contaminating source. Researchers showed that liquid waste from shale gas fracking operations is chemically different than waste flowing out of conventional wells. The researchers hypothesized that the hydraulic fracturing process itself liberates elements from clay minerals in the shale formations, including boron and lithium, which then enter the liquid waste.