Dredging up trouble
Hudson PCB removal worsens the problem, objective studies show
By Robert A. Michaels
Sunday, January 23, 2011
A saying goes: “Fool me once, shame on you; fool me twice, shame on me.”
The saying does not cover the much larger number of times the public has been misled by technically flawed claims by the federal Environmental Protection Agency that dredging PCB-contaminated sediments from Hudson River “hotspots” is safe and effective. Abundant evidence and expert advice say that it is neither.
In 1962, Rachel Carson’s blockbuster “Silent Spring” revealed that PCBs’ almost-twin brother, DDT, was destroying ecosystems. Its actions were subtle, such as thinning the eggshells of predatory birds. DDT’s subtlety fooled us into focusing mainly upon its benefits, such as killing malarial mosquitoes. DDT and PCBs are so similar structurally that, until the 1960s, environmental monitoring could not tell them apart, and findings regarding DDT included PCBs. The effects of PCBs and DDT were attributed to DDT alone.
DDT and PCBs caused damage from which global ecosystems are still recovering, a half-century later. Bald eagles and peregrine falcons were at the brink of extinction.
The entry of PCBs into the Hudson River environment via dredging may set the clock for river recovery back by decades. PCBs, however, decay faster than DDT, so natural decomposition may be a better route to a cleaner river than dredging.
In 2007, two years before dredging Phase 1, an article in the Cambridge University Press journal Environmental Practice showed that EPA’s “baseline” health risk assessment drastically underestimated Hudson River PCB risks to public health. Worse, nine critical parameters had been misestimated and, more to the point, all nine had been misestimated in the dredging-friendly direction. The authors, myself and engineer Uriel Oko, concluded that EPA’s assessment had been biased systematically in favor of dredging.
In the summer of 2010, Dr. Oko and I submitted a manuscript evaluating dredging Phase 1. Our second Environmental Practice article, just released, showed that dredge buckets dropped more PCB sediment back into the river than into barges, and EPA’s environmental monitoring program would miss potentially the most significant releases of PCB to Hudson River water, air and ecosystems. We called for EPA disclosure of data from exposure monitors worn by GE contractors working on dredge platforms (minus personal information).
About two months after we submitted our manuscript, a six-member panel advising EPA on Hudson River PCB dredging released its report. EPA had prohibited the panel from saying whether dredging should continue, or whether dredging as planned in Phase 2 could meet the project’s health goals. Despite EPA’s “don’t ask, don’t tell” gag order, the panel boldly and clearly suggested that dredging could not proceed on schedule while protecting public health, stating also that changes in strategy proposed by GE and EPA would not change this dire prediction.
Signs of trouble
Even before last summer, evidence of trouble had emerged. GE’s March 2010 report evaluating Phase 1 found that dredging had “caused previously buried PCB-containing sediments to migrate downstream and settle on the surface of the river bottom, where they became bioavailable . . . and downstream sediment cores of previously sampled areas showed an average increase of three times pre-dredging concentrations. These and other lines of evidence show that dredging caused widespread redistribution of PCB-containing sediments on the surface of the river bottom.” EPA’s own report did not dispute this finding.
The problem will be worse if Phase 2 is undertaken, because the PCB hotspots to be dredged are farther apart than in Phase 1. PCB-contaminated sediment falling back into the river downstream of the original dredging location will not be dredged again. It will remain mobile in the river. Currents will erode it from the river bottom and carry it to downstream water, air and ecosystems.
In short, four studies, including one commissioned by EPA, all deliver essentially the same message: EPA’s safety claims for past dredging and planned future dredging are technically flawed. They remain unsubstantiated, and therefore should be rejected, just as your claim for a tax deduction would be rejected if you could not substantiate it when required to by the IRS.
EPA’s persistence in the face of technical refutation of its safety claims is a mystery. My tentative explanation is politics. Politics may explain why a project planned during three Bush presidential administrations spanning 12 years is sending PCBs and a half-billion dollars to Texas, rather than using a secure landfill in New York for a fraction of the price.
Politics may explain why the environmental interests of groups such as the Riverkeeper and Sierra Club so far have prevailed over the public health interests of riverfront communities. As a scientist, I take no political position on dredging. But I strongly advocate restoration of scientific objectivity to the decision process.
Objectivity tells me, and it should tell you, that the PCB problem is not primarily the unknown mass and volume of PCB that lies buried in the river bottom; rather, the problem is the area of exposed river bottom from which PCB-contaminated sediments may enter water, air and ecosystems.
Objectivity tells me, and it should tell you, that dredging can reduce the mass and volume of buried PCB by a lot, while still making the PCB problem a lot worse by expanding the small area of contaminated river bottom. That, by all accounts including EPA’s, is what dredging is doing — objectively speaking.
A chink has appeared in EPA’s armor: caps to cover incompletely dredged river areas. Allowing capping is EPA’s way of admitting that natural degradation of PCBs remaining in the river bottom is preferable, at least in some areas. The fraction capped in Phase 1 was a whopping 37 percent. Although EPA says the fraction will be less in Phase 2, the Phase 2 number is just a target. Practicality may force EPA to allow more capping this spring, thereby requiring less dredging. Stay tuned.
Robert Michaels is president of Schenectady-based RAM TRAC Corporation, consulting in health risk assessment and management.