Simple Google search for the single word "Imprelis", DuPont's chemical herbicide.
As of 1 August 2011, eight of the ten displayed hyperlinks are not marketing/product pages.
From Michigan State University: What to do with Imprelis-affected trees
Also from Michigan State: Imprelis herbicide may injure evergreens
From Mother Earth News: Imprelis, another deadly herbicide, this time from DuPont
If DuPont's EPA-approved Imprelis (aminocyclopyrachlor) is causing said alleged ecological damage (it has yet to be legally proven), what could be expected as far as clean-up goes? What could you possibly do in a contamination situation, if such a situation were to exist?
Drink bottled water and don't eat your garden's vegetables.