A Sea in Flames - Carl Safina [109]
And then there’s “fracking,” wherein engineers actually pump fluids at high pressure to shatter rock formations up to several miles underground to get the gas they contain. This practice is increasing because the resources are getting depleted. It’s a long way from tapping surface seeps. In the East, the big target is the Marcellus Shale, which underlies states from Virginia to New York and into Canada. Its recoverable gas has been estimated at 49 trillion cubic feet, about two years’ total U.S. consumption, worth about $1 trillion.
If you’ve already heard of fracking, here’s a new vocabulary word: “proppant.” In a sentence: “Proppant, such as grains of sand of a particular size, is mixed with the treatment fluid to keep the fracture open when the treatment is complete.” This is all injected deep into the Earth. In shales they use oil-based drilling fluids when they’re getting down to the reservoir, and then the fracturing fluids pumped down contain a multitude of sins—proppants, gels, friction reducers, breakers, cross-linkers, and surfactants similar to those in cosmetics and household cleaning products. These additives are selected to improve the “stimulation operation” and the productivity of the well. The fluids are 99.5 percent water, but it’s the other .5 percent that matters. The New York State environmental impact statement for drilling to frack the Marcellus Shale has six pages of tables listing the many components of fracturing fluids.
You can begin to imagine the above-ground mess and risk of all this fluid. Then there is the little issue of drinking water. Experts say it’s not a problem. The New York State environmental impact statement reads, “Regulatory officials from 15 states have recently testified that groundwater contamination from the hydraulic fracturing procedure is not known to have occurred despite the procedure’s widespread use in many wells over several decades.”
The Environmental Impact Statement says that there is a vertical separation between the base of any aquifer in New York (850 feet) and the target shales (below 1,000 feet, although it also, confusingly, gives this depth as above 2,000 feet). It says the rock between the target shales and the aquifers is impermeable, so it should be an effective migration barrier.
Go ahead and take a big sigh of relief.
Now get worried again. The big case everybody cites is Pavillion, Wyoming, where gas fracking has been happening for a while. After several years of complaints by residents, the U.S. Environmental Protection Agency sampled nineteen drinking-water wells and, in August 2010, confirmed in eleven the presence of 2-butoxyethanol phosphate (probably from frac fluids), plus adamantane compounds (definitely from fracking) in four wells, and methane in seven. This is the first confirmed case of frac fluids getting into groundwater. It’s possible that the fluid contaminants got into the wells—into people’s drinking water—from surface spills; but the methane is conclusively from the underground reservoir. The final EPA Pavillion report is recent and is the smoking gun for opponents of fracking.
And now a dash of good news, a step toward the techno prep that was needed in the Gulf all along: ExxonMobil, Chevron, ConocoPhillips, and Royal Dutch Shell announce plans to voluntarily contribute $250 million each to build what they should have had warehoused already: modular containment equipment that would be on standby, capable of capping a blow-away well or siphoning and containing up to 100,000 barrels of oil daily in the next leak or spill. (BP is not included initially but will join in September 2010.)
Ulterior motive: the companies want Obama to lift his ban on deep exploratory drilling.