"In fact 97% of the PCBs are in the insulation around electrical wires. On top of that no one points out that the EPA did a 2 year study to test PCBs leeching out of the materials on the Oriskany, and found negligible amounts actually leeched out. Their data (with actual numbers) can be found on the web. "
I don't consider a 2 year study to be sufficient to analyze the risks. What they have done, in effect, is turn the O' into a 1,000 year study. What if we learn in 10 years that an unanticipated coral or algae or something has broken down the electrical insulation and PCBs start to bioaccumulate in the fish stocks?
They could have removed the PCBs, but chose not to because of costs. If they are wrong, the damage to the fisheries could be much, much greater than the costs of removing the PCBs. And, as Rik points out, if costs allowed 700 lbs to be dumped this time, what will be the cut off next time? Personally, I would prefer to err on the side of caution rather than on the side of potentially saving some money in the short term.