[Elspode]

I don't live out East, but I, too, would be leery of the harbor muck of NYC being put anywhere except at the bottom of NYC Harbor. The effluent of a significant portion of America's population has settled there, containing anything and everything that people have thought to flush down a toilet or pour into a storm drain or creek. That's some pretty goddamn nasty stuff, indeed.

I would be willing to reconsider if someone had done any testing of the fly ash and muck "hard" mixture to show that it remains stable, but I guarantee you that it will erode over time. Might be a long time, but erode it will, taking with it all those nasties and redepositing them somewhere else.