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Fortuitous event during a Superfund clean-up


Narrator:            This is Science Today. An unexpected, but fortuitous event occurred during the successful cleanup of a Superfund site in Southern California. Geophysicist Roger Aines of the Lawrence Livermore National Laboratory helped develop the steam-cleaning technology used at the Visalia Pole Yard, and says the contaminants there oxidized very slowly, which proved to be very important.

Aines:                  What oxidize means, well it's the same thing that happens if you burn them, in this case there's no flame. They're simply being reduced to carbon dioxide if there's oxygen present. And it turns out that since you're pumping water into these sites all the time, that water is carrying oxygen in with it because it's in the normal groundwater. As that water gets hot, that oxygen combines with the contaminants and almost a third of the contamination at Visalia was in fact destroyed by that process. So, it never had to be brought out and incinerated at the surface, it was destroyed underground. And that's why the site was removed from the Superfund list because that final polishing step proved to be so effective.

Narrator:            In fact, the Visalia site was cleaned up 100 years sooner than expected. Science Today, I'm Larissa Branin.