On remediation of contaminated farm land, I was kind of curious
about this myself. I know what happens on industrial SuperFund sites,
because we have one nearby:
http://epa.gov/superfund/programs/re...ers/asarco.htm
(I am always kind of nervous about collecting wood chips, tree leaves,
etc, from that end of town. "Rhododendron mulch only.")
Here is the Wikipedia article on bioremediation. Of particular interest
in this context is the third paragraph, on dealing with heavy metals
contamination:
http://en.wikipedia.org/wiki/Bioremediation
Here is the Wikipedia article on specifically phytoremediation, growing
plants that will absorb the contaminants so that they can be removed
along with the above-ground part of the plant:
http://en.wikipedia.org/wiki/Phytoremediation
(Remembering what happened in Quincy, one does need to resist
the temptation to give the harvested plants to a neighbor for livestock
feed. I do not know what is typically done with the phytoremediation
plants after they are harvested.)
And finally, a company in Texas that specializes in this sort of land
recovery:
http://phytofarms.com/phytoremediation-projects.html