Saturday, March 26, 2011

Less Data, More Doubt About Hudson River PCB Dredging

Dr. Robert A. Michaels*

Imagine you are a powerful federal environmental agency concerned about GE’s disposal of DDT’s almost-twin, PCBs, from 1947 to 1977 into the Hudson River and to neighboring land. You might do what EPA did in 1984: add the Hudson River Superfund Site to the National Priorities List for remediation to be paid for by the polluter. You would study the river, and find ways of cleaning it, including letting nature degrade the PCBs the way nature does: naturally. ‘Natural attenuation’ was specified initially because EPA was uncertain about the safety and effectiveness of dredging.

If you really wanted to dredge regardless of safety, you might do what EPA did in 2000: drastically underestimate Hudson River PCB risks, then design a demonstration project that would fail to collect data to enable warning of harm in real time, and project evaluation over years or decades. You might call it Phase 1, which EPA mandated in 2002 to evaluate use of dredging to clean the Hudson. Conducted in 2009, Phase 1 evidently failed, even based upon limited data collection required by EPA.

Data collection in Phase 1 was extensive in the ‘far field’, far from dredge platforms, but inadequate in the ‘near field’, at dredge platforms. PCBs were monitored in water five to seven miles downstream of dredges, but not at the dredges. Waterborne PCB concentrations at dredge platforms, therefore, are anyone’s guess. If dredging disrupted pure PCB oils, which were disposed into the river and to the land for three decades, they would not be detected until massively diluted during miles of downstream transport in a turbulent river.

PCBs were monitored in air via portable samplers on opposite riverbanks alongside each dredge platform. The samplers were nearly useless, because they averaged PCB concentrations over 24-hour periods. The wind came from all directions, so PCBs originating from dredge platforms were massively diluted by clean air from other directions. As dredge platforms moved downstream, the portable samplers followed, leaving none to record evolving concentrations of airborne PCB, whose release from river water may be delayed significantly and continue indefinitely. As more river was dredged, the number of samplers remained constant, resulting in fewer samplers per acre dredged. At the end of Phase 1, the portable samplers were withdrawn, not just downstream, but altogether, leaving no samplers to record evolving airborne PCB levels over future months and years.

Airborne PCB also was sampled via personal samplers worn by employees working on dredge platforms. These samplers, however, had a detection limit of 1000 micrograms per cubic meter, nearly 100 times EPA’s residential Level of Concern for PCBs, reflecting a higher limit for occupational exposure. Despite numerous requests, EPA has failed to release this data, without which the public cannot know if airborne PCB was detected even above this high concentration.

Despite data gaps, the failure of Phase 1 was evident from several objective indicators. Only 10 of 18 five-acre Phase 1 work units were dredged, because PCBs were found in a deeper layer of sediments, requiring more dredging time. Even in dredged work units, PCB sediments were not removed as planned: 37 percent were capped to prevent PCB from entering river water, ecosystems, and air. That is, EPA allowed GE to restore these areas, as best it could, to pre-dredging conditions, with PCBs buried beneath clean sediment.

Dredge buckets dumped more material back into the river than into barges, because they encountered obstacles in the river bottom, such as tires, logs, rocks, concrete blocks and other construction debris, preventing them from closing completely. Worse, nearly pure PCB oils were found, unlike sediments harboring PCBs in merely the low parts-per-million range. Of course, the material dumped into the barges did not include the disrupted liquid PCB oils, which now are spreading, with dredge-mobilized sediments, to downstream water, ecosystems, and air.

Repeatedly, EPA’s water monitoring station five to seven miles downstream of dredge platforms revealed PCB at levels above the stop-dredging threshold. Repeatedly, levels in air adjacent to dredge platforms revealed levels above the stop-dredging threshold. Repeatedly, dredging had to be suspended.

As part of the demonstration project, EPA convened a Peer Review Panel to evaluate Phase 1. The Panel’s initial report, to which GE and EPA responded, raked EPA over the coals, most notably saying:

"The incomplete analysis done for the 2004 [Engineering Performance Standards] does not consider near-field and far-field PCB deposition rates on the sediment bed surface."

This little statement has a huge meaning: EPA failed to consider sediment mobilization at dredge platforms (the ‘near field’). That is huge, because dredge platforms are where dredged sediments are mobilized, and where the Peer Review Panel accused EPA of failing to look. Here is EPA’s revealing response:

“EPA did simulate near field suspended matter transport and settling in its near-field modeling analysis. The HUDTOX model runs did not reflect the near-field settled solids but did incorporate an estimate of dredging-related suspended solids transport 1000 meters downstream of the dredge. This analysis was the basis for the EPA forecasts of dredging-related resuspension” [emphasis added].

That technical response is a huge admission of how EPA suppressed expected dredging impacts, because nearly all dredged material that leaks out of dredge buckets initially falls to the river bottom near the point of dredging, whereas EPA predicted sediment mobilization based upon the miniscule amount resuspended and transported 1000 meters (over a half mile) downstream. EPA’s statement shows how the agency justified dredging by ignoring the gradual erosion from the river bottom of nearly all dredge-mobilized PCB-bearing sediments over a period of years or decades, and entry of PCBs from these sediments into downstream water, ecosystems, and air.

In January an article in the Cambridge University Press journal Environmental Practice showed that a major discrepancy exists between sediment mobilized in dredging Phase I versus the much smaller amount measured and reported by GE. Its authors, myself and engineer Dr. Uriel Oko, showed that the preponderance of mobilized sediment remains on the river bottom, still mobile, but unrecorded in GE or EPA sediment mobilization data. We termed this the “sediment mobilization discrepancy.”

The sediment mobilization discrepancyrepresents more than merely a difference between a measured and an actual parameter value. Rather, it represents a fundamental inconsistency in EPA’s past justification of the need to dredge versus EPA’s current characterization of the performance of the dredging project in Phase 1. The need for dredging was justified by the mobility of sediments in PCB “hotspots” requiring, according to EPA, their removal by dredging. In contrast, in the new context of actual dredging in Phase 1, EPA dramatically altered its concept of mobility. Mobility in the dredging project is newly quantified by the miniscule fraction of mobilized PCB that is detected miles downstream. Thus, EPA simply has ignored nearly all sediment and PCB mobilization in evaluating Phase 1, notwithstanding that the persistent mobility of dissolved, colloidal, and fine-particle-adsorbed PCB originally constituted for EPA a central rationale for specifying the dredging remedy for the Hudson River PCB Superfund site.

The Peer Review Panel rejected EPA’s response, concluding in its final report:

“Phase 1 showed that the 2004 EPS [Engineering Performance Standard] for Resuspension, Residuals, and Productivity were not met individually or simultaneously during Phase 1 and cannot be met under Phase 2 without substantive changes. EPA and GE proposed changes to the EPS, but the Panel finds that the new proposed standards from either party would not contribute to the successful execution of Phase 2” [page 84].

EPA had prohibited the Panel from saying whether dredging should continue, or whether Phase 2, if undertaken, could meet project health goals. What is proper to assume about EPA’s ‘don’t-ask, don’t-tell’ gag order? Did EPA fear receiving advice that might undermine a political decision to dredge? What is proper to assume when any party, including a powerful federal environmental agency, acts in a manner that assures unavailability of critical information?

Regulatory agencies, scientists, lawyers, and IRS agents have rules about what is proper to assume. If you can’t substantiate your claim of a tax deduction, the IRS properly will assume that your questionable income should be taxed. If you can’t produce records that substantiate that your factory’s chemical discharges were within permitted limits, your regulator properly may penalize you. The proper assumption is that failure to document is the moral and legal equivalent of failure to comply. Penalties for recordkeeping violations may be as harsh as for documented permit violations. EPA’s stance on dredging therefore must be viewed in the context of what is proper to assume when critical information is distorted, withheld, or not developed.

*Dr. Michaels performed original research on DDT and PCBs for his Masters thesis and Doctoral dissertation. He is president of Schenectady-based RAM TRAC Corporation, consulting in health risk assessment and management. Dr. Michaels is aware of no conflict of interest, and has received no funding or promise of funding for this work.