Back in the old days, before 1995, the water supply for the station was provided by melting snow. Fuel at the south pole all has to be flown in in the wing tanks of a C-130 Hercules turbo-prop cargo plane. For every gallon of fuel delivered to the south pole, two gallons are burned by the delivery aircraft. Add to that the cost of sending a sea-going tanker to McMurdo station, the nearest major depot, storage, and infrastructure... and the cost of fuel at the pole is about $8 to $11 per gallon. Fuel, by the way, is JP-5, the same jet fuel the delivery aircraft burns. (BTW, a tanker of fuel is about 4KW-Years... for a 3000 gallon delivery)
Some very clever person noted that the electric power generator plant at the site, through it's exhaust, discarded a considerable amount of heat. They thought... 'Rodriguez well!' with a twist a twist... At the pole they heat water with the generator exhaust manifold and muffler (capturing the 'waste heat'), and use it to melt ice in a novel sort of water well.
They 'construct' the well by 'drilling' with a
hot water sprayer into a hole in the snow to a depth of about 80 to 100
feet (the firn layer). Then they spray/pour in about 2000 more
gallons of water until the snow is
well consolidated. Finally, to bring the well on line, they pump in hot water, and pump out cool water which they circulate again through the heat exchanger on the power plant. In the picture, the power plant is where the plume of 'smoke' is rising from the left of the picture. When the operation is going well, they can divert pump out about 14 gallons of water per minute for the needs of the station. That's a 'Rod well'...
As you might guess, the water is quite pure. In fact, it's about as pure as deionized water... That high purity actually causes problems. DI water is not recommended for ingestion unless enough minerals are dissolved in it to make it comply with drinking water standards. DI water wants to have ions dissolved in it. It will get those ions from the water pipes, it flows through... The pipes are usually copper... with joints soldered with tin-lead solder... High levels of copper, and even minute levels of lead ions are bad for you... so chemistry comes to the rescue. Dissolving sodium and calcium ions into the water suppresses the tendency to pick up copper and lead ions... hence saving the pipes from chemical erosion.
When the well gets to be 500 feet deep, the elevated cost of pumping favors starting a new well, so they pump out all the water and start again a few hundred feet away. The last use they get from the old well is by lowering a crew inside to chip out the bottom layer of ice; it's full of meteorites which settled to the bottom (were released from the ice) as the well was evolving. The meteorites have scientific value.
The Rod well has one more use... they declare it to be the next sewer outfall.
see also http://www.polar.org/antsun/Sun011203/water.htm for a little more information on water at the various stations in Antarctica...
G. Przybylski -- LBNL March 7, 2003
see also http://www.polar.org/antsun/oldissues2001-2002/2002_0113/continent.html for a snippit
If interested in tunneling, http://www.polar.org/antsun/oldissues2001-2002/2002_0127/tunnels.html
If interested in the overland traverse to the pole, http://www.polar.org/antsun/oldissues2002-2003/Sun011203/itase.html