Are Fracking Wastewater Wells Poisoning the Ground beneath Our Feet? Leaking injection wells may pose a risk–and the science has not kept pace with the growing glut of wastewater by Abrahm Lustgarten and ProPublica, June 21, 2013, Scientific American
Florida’s injection wells, for example, had been drilled into rock that was far more porous and fractured than scientists previously understood. “Geology is never what you think it is,” said Ronald Reese, a geologist with the United States Geological Survey in Florida who has studied the well failures there. “There are always surprises.” Other gaps have emerged between theories of how underground injection should work and how it actually does. Rock layers aren’t always neatly stacked as they appear in engineers’ sketches. They often fold and twist over on themselves. Waste injected into such formations is more likely to spread in lopsided, unpredictable ways than in a uniform cone. It is also likely to channel through spaces in the rock as pressure forces it along the weakest lines.
Petroleum engineers in Texas have found that when they pump fluid into one end of an oil reservoir to push oil out the other, the injected fluid sometimes flows around the reservoir, completely missing the targeted zone. “People are still surprised at the route that the injectate is taking or the bypassing that can happen,” said Jean-Philippe Nicot, a research scientist at the University of Texas’ Bureau of Economic Geology. Conventional wisdom says fluids injected underground should spread at a rate of several inches or less each year, and go only as far as they are pushed by the pressure inside the well. In some instances, however, fluids have travelled faster and farther than researchers thought possible.
In a 2000 case that wasn’t caused by injection but brought important lessons about how fluids could move underground, hydrogeologists concluded that bacteria-polluted water migrated horizontally underground for several thousand feet in just 26 hours, contaminating a drinking water well in Walkerton, Ontario, and sickening thousands of residents. The fluids travelled 80 times as fast as the standard software model predicted was possible.
According to the model, vertical movement of underground fluids shouldn’t be possible at all, or should happen over what scientists call “geologic time”: thousands of years or longer. Yet a 2011 study in Wisconsin found that human viruses had managed to infiltrate deep aquifers, probably moving downward through layers believed to be a permanent seal.
According to a study published in April in the journal Ground Water, it’s not a matter of if fluid will move through rock layers, but when. Tom Myers, a hydrologist, drew on research showing that natural faults and fractures are more prevalent than commonly understood to create a model that predicts how chemicals might move in the Marcellus Shale, a dense layer of rock that has been called impermeable. The Marcellus Shale, which stretches from New York to Tennessee, is the focus of intense debate because of concerns that chemicals injected in drilling for natural gas will pollute water. Myers’ new model said that chemicals could leak through natural cracks into aquifers tapped for drinking water in about 100 years, far more quickly than had been thought. In areas where there is hydraulic fracturing or drilling, Myers’ model shows, man-made faults and natural ones could intersect and chemicals could migrate to the surface in as little as “a few years, or less.” “It’s out of sight, out of mind now. But 50 years from now?” Myers said, referring to injected waste and the rock layers trusted to entrap it. “Simply put, they are not impermeable.” [Emphasis added]
[Refer also to:
Walkerton: ‘A nightmare that won’t end’ by CBC News, April 5, 2012
In May 2000, bacteria seeped into Walkerton’s town well. The deadly E. coli then slipped quietly through a maze of pipes and into the homes of Walkerton, Ont. Unsuspecting residents thirstily drank the polluted water and bathed in their bacteria-ridden tubs. But soon after, they began experiencing common symptoms of infection; bloody diarrhea and throbbing cramps. Seven people would eventually die and another 1286 would fall ill. The investigation which followed exposed an alarmingly unstable waterworks system made fragile by government cuts. “This is a very scary time we’re going through right now,” says Chris Trushinski, the owner of Mel’s 49 Diner and Gas Bar in Walkerton, Ont. Trushinski describes an anxious and angry community. Trushinski, for one, is upset with Premier Mike Harris’ budgetary cuts. He believes the reduced Ministry of the Environment has left the water supply vulnerable. Residents are leaving town temporarily and those who stay behind are under extreme duress. Trushinski says that he boils the diner’s water and has sterilized the diner but this has done little entice paying customers. Instead, Mel’s 49 Diner has become a meeting place for people to commiserate. [Emphasis added]
Walkerton: Criminal charges by CBC News
An Alberta Perspective on the Migration of Surface Water Pathogens to Groundwater Aquifers: A Literature Review and Brief Analysis by Tristan Goodman, May 14, 2004, Alberta Energy and Utilities Board, Environment Group
The following is an overview of the issues and conclusions found in the peer-reviewed literature on the migration of surface pathogens to groundwater aquifers. … In the case of this study, focus looks specifically at the potential for pathogen contamination of groundwater from drilling fluid used in the oil and gas industry in Alberta. The drilling fluids use untreated surface water. Concern has been express over the use of untreated water being used in drilling fluids and its potential to contaminate groundwater sources. …
In the case of the oil and gas industry migration of pathogens to groundwater would be anthropogenic because of the use of untreated water in drilling [and fracturing] fluids. No specific work has been conducted around the injection of bacteria. The water that makes up the drilling fluid, is taken from sources in the local area. Such sources include local rivers, lakes smaller bodies of water or groundwater and will contain some measure of pathogens. Despite the act of place pathogens into close proximity to groundwater aquifers the life expectancy of pathogens, chemicals reaction of pathogens with soil and the filtration rates all prevent pathogen migration beyond a few metres. [The EUB did not include the Walkerton Case in their review, or that oil and gas companies are hydraulically fracturing with untreated surface water directly into drinking water aquifers in Alberta, and thousands of wells above the Base of Groundwater Protection, where the fresh water is.]