Under pressure from area environmentalists, the Port of Seattle is reconsidering its plan to dump silt laced with toxic PCBs (Polychlorinated Biphenyls) into Elliott Bay.

PCBs, which are carcinogenic and build up in marine ecosystems, have been linked to reproductive and immune system deficiencies in humans.

The Port had initially planned to move around 60,000 cubic yards of sediment from near the Port’s Terminal 30 — roughly a third of which was tainted with PCBs — into a designated dumping area in Elliot Bay. The dumping had passed muster with all federal and state environmental standards, but local environmentalists argued the standards were out of date.

The dredge-dumping site in Elliott Bay is one of eight in Puget Sound, but, said People For Puget Sound’s Heather Trim, these sites were designated under the assumption that only “clean dredge” (non-polluted river runoff) would be dumped.

“We understand the Port needs to clear the dredge, but [the site in Elliott Bay] was not intended for PCBs,” says Trim.

Under the new plan, the dredge polluted with PCB would be shipped by rail to a site in Eastern Washington or, if research determines extreme levels of toxicity, to Utah. A county taskforce has been given 90 days to make a recommendation to the port commissioner’s office.