John Farley of MetroFocus writes that the job of cleaning up Superfund sites "is an economically, politically and physically arduous one." Farley looks at these four sites, how they originally came to be polluted, what they are polluted with, and recent efforts to begin cleanup.
"Throughout the 20th century, the banks of the Passaic were lined with mills and factories, causing severe pollution. The worst offender was the Diamond Shamrock Chemical Plant in Newark, which produced the chemical weapon Agent Orange, according to The Star-Ledger. The sediment at the bottom of the river's mouth, near Newark, is lined with dioxin, a carcinogenic component of Agent Orange. Diamond Shamrock went out of business before the area was declared a Superfund site, but this past summer, after years of legal wrangling, a federal judge forced the companies that now own the site, Tierra Solutions Inc. and Occidental Chemical Corporation, to clean up the river."