It shouldn’t come as any surprise that a task force appointed by Texas Railroad Commissioner David Porter has ruled that the aquifer in South Texas is sufficient to support hydraulic fracturing operations in the area’s sizzling Eagle Ford Shale play. It was a foregone conclusion, after all. But that’s not why I decided to scribble this down. No, it’s because when I read the rather small notice in the Houston Chronicle, I saw something rather interesting.
According to the article, Porter boasted that the oil and gas industry “has reduced the amount of water it uses to hydraulically fracture wells to about 11 acre-feet of water to complete each well, down from about 15 acre-feet.” [the article originally said 14, but was edited to 15 later]
It struck me as interesting because, just the day before, I’d seen a sign on the side of a garbage truck announcing that the waste company had reclaimed “17,000 acres” of parks and wetlands. At the time I wondered how many of the folks in Houston
But getting back to acre-feet… an acre-foot of water is one acre of water one foot deep. Since you don’t know what an acre is, let’s put that in terms of square feet: an acre is 43,560 square feet, so an acre-foot of water is 43,560 cubic feet. Still not clear? How about gallons? A cubic foot is 7.48 gallons – about half a tank of gasoline. So that measly eleven acre-feet becomes 11 times 43,560 times 7.48 gallons. That’s 3,584,116.8 gallons, if you forgot your calculator.
Considering that during the Macondo blowout the Chronicle decided they had to talk about amounts of oil in terms of gallons instead of (42-gallon) barrels – presumably because people don’t know how big a barrel is – it seems kind of odd that they didn’t convert acre-feet to the same units.
I’m gonna file this in the “Statistics Never Lie but Liars Use Statistics” area, under the “Unpleasant Things Always Seem More Benign when You Use Small Numbers to Describe Them” subcategory…
