Environmental groups recently have been advocating expansion of Hudson River PCB dredging. They are premature at best, given the ongoing five-year review by EPA of the dredging project, required under the Superfund Law. Maybe politics will drive the result of this review, but EPA and environmental groups should consider the documented, substantial long-term consequences of dredging, rather than seizing on the simplistic, short-term expedient of digging up more PCB sediments. From personal experience, for example as past toxicologist for the Natural Resources Defense Council, I know that taking the long view is a hallmark of environmental activism.

Here are some observations that EPA should factor into its five-year review of the dredging project. After the first season of dredging, GE reported that sediment samples outside the dredged area “show that dredging caused wide-spread redistribution of PCB-containing sediments on the surface of the river bottom.” High-flow events already have driven some of this dredge-mobilized sediment downstream.

Future high-flow events, over years to decades, likewise will transport dredge-mobilized PCB sediments downstream, where they will enter water, air, and ecosystems. This includes the habitat of Hudson River sturgeon, recently classified as “endangered” by the Commerce Department, which now must protect its habitat–principally the Hudson River–under the Endangered Species Act.

Maybe the environmental groups seeking to expand dredging think that EPA ‘resuspension’ data indicate that dredge-mobilized PCB is not a problem… but this is false. EPA’s official Hudson River PCB Dredging Peer Review Panel concluded in 2010 that EPA had failed to set an allowable sediment loading limit, failed to gather data needed do this, and failed to develop models to predict transport of dredge-mobilized sediment and PCB bioaccumulation based upon Hudson River hydrodynamics.

That is, EPA’s own Peer Review Panel position was that EPA sampling of resuspended PCB was not enough, because EPA failed to sample or model the vastly larger quantity of dredge-mobilized PCB resting on the river bottom. The Agency, therefore, cannot assure the public that transport of sediment already mobilized by dredging won’t increase for decades, threatening ecosystems in the Lower Hudson River. It cannot assure the Commerce Department that endangered sturgeon can survive decades of increased PCB transport to the Lower Hudson River. Yet, the Agency seeks to resume dredging.

Phase 1 dredging was supposed to demonstrate the feasibility of Phase 2, but it did not do so. It was designed to succeed because it featured bank-to-bank dredging to reduce mobilization of PCB sediments. Even so, the project snatched defeat from the jaws of victory, because massive sediment mobilization occurred anyway. More will occur in Phase 2, because only PCB ‘hotspots’ will be dredged. Mobilization will transport PCB to areas of the river bottom that are not slated for future dredging.

Under normal river conditions only a miniscule fraction of this dredge-mobilized sediment (which EPA does not monitor) is resuspended right away. Last spring, high flow delayed Phase 2 dredging for weeks. EPA data now indicate that massive amounts of PCB were resuspended and carried downstream during that event. Spinmasters, including environmental groups, stated without justification that even more PCB would have been transported without dredging. EPA stated, remarkably, that no long-term damage to the river was done. If PCB transport does not cause long-term damage, then what was EPA’s justification for dredging? The answer, my friends, is blowing in the wind.

Contrary to agency spin, transport of PCB did increase because of dredging, as EPA always expected. Transport of PCB sediments to areas that will never be dredged is clearly demonstrated, and was so severe in Phase 1 that EPA was forced to change its dredging procedures for Phase 2. Even so, GE data show that net benefit of dredging will not be achieved for 46 years, even under wildly optimistic assumptions. More likely, net benefit never will be achieved, because more PCB-laden sediments, distributed over more of the river bottom, will be biologically available and toxicologically active with dredging than without, for the foreseeable future.

High-flow events such as storms are forecast to occur with increasing frequency in the future. Future events will have more severe consequences, as the area of dredged river bottom increases. Over years to decades, cumulative transport of dredge-mobilized PCB sediments may nail the coffin shut on recovery of endangered sturgeon in the Lower Hudson.

EPA should address these issues in its five-year review of dredging. Certainly, the Commerce Department will. Environmental groups likewise should consider them, to protect Hudson River communities and ecosystems. To be an environmental activist is to take the long view. Environmental groups can ignore long-term consequences of positions that they advocate for short-term benefit… but only at the peril of their legacies.