Since I posted the original 2009 USGS decision on the 'one word or two' kerfuffle I figured I should do the same for the last (?) major holdout among federal agencies.
A few days ago I Tweeted that EPA now prefers to spell 'groundwater' as one word. Robert Alvey of EPA initially told me of this and now has provided this memo as proof:
Distributed via “Sharepoint” to EPA Ground Water Forum members. July 7, 2016
The latest from the EPA's Web Council Support, on whether Ground Water is one word or two: "This is to let you know that OPA has changed the writing portion of the EPA Stylebook to indicate that “groundwater” is preferred over “ground water.” The Stylebook now says:
Groundwater - Groundwater is preferred over ground water as both adjective and noun; avoid the hyphenated ground-water.
We have made this change because the editor of the AP Stylebook, which EPA follows, has, since the publication of the EPA Stylebook, stated a preference for the one-word “groundwater” “per dictionary preferences” and “per customary usage in AP stories.”
If you use “ground water” on your site, there is no need to change it. In the future, please use “groundwater”, or keep using “ground water” if you need to be consistent with your existing multitudinous references to “ground water.”
Lest you think I am fabricating this, go here, then scroll down to Spelling - One Word or Two? where you will see this entry:
Groundwater - "Groundwater" is preferred over "ground water" as both adjective and noun; avoid the hyphenated "ground-water".
My advice: get over it. As my late PhD advisor Gene Simpson, originally an English major at CUNY, said to me: 'English is not a logical language.'
Here is what I said in my post, The Great Hydrogeologic Question of Our Era: One Word, or Two, or Who Cares?
When I started writing my dissertation, I used "ground water"; Gene changed it to "groundwater". When I tried to make my case, citing that since we spelled the following as two words - surface water, lake water, ocean water, soil water, etc. - we should be logical and spell it as 'ground water', Gene replied, "English is not a logical language." No response to that.
He then explained that much of the early work in ground water hydraulics had been done by German-speaking scientists and engineers: Philipp Forchheimer, Gunther and Adolf Thiem, Karl Terzhagi, et al. As is the custom in German, "Grund" and "Wasser" were combined to form "Grundwasser". Many of the early English-speaking water engineers and scientists adopted this convention. But many didn't, following my logic.
In retrospect I have flip-flopped throughout the years. Whether I used "groundwater" or "ground water" largely depended upon which ground water book I was using for my classes: Groundwater by R. Allan Freeze and John Cherry; Groundwater Hydrology by Herman Bouwer; Applied Hydrogeology by Bill Fetter (who used two words); Hydraulics of Groundwater by Jacob Bear.
There actually has been a fair amount of discussion on one word vs. two, including a brief article by A. Ivan Johnson (1986), which comes down strongly on the side of two words (the article starts at the bottom of the first page):
Then Allan Freeze, one of the world's foremost hydrogeologists, penned this "allegory" several months later in 1987:
Freeze is telling us not to take this too seriously, which is good advice.
Alas, it's all over. Gene is happy in his grave, and my work here is done.
Enjoy! And thanks to Robert Alvey.
The line it is drawn the curse it is cast
The slow one now will later be fast
As the present now will later be past
The order is rapidly fadin'
And the first one now will later be last
For the times they are a' changin'!
-- Bob Dylan, The Times They Are a-Changin'
"By such innovations are languages enriched, when the words are adopted by the multitude, and naturalized by custom." -- Miguel de Cervantes Saavedra, author of Don Quixote (thanks to Terry Meyer)