Sunday, October 25, 2009

FIRESIDE CHAT: Hudson River PCB Dredging and Air Monitoring

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Phase I of GE’s EPA-mandated PCB dredging project focusing on selected hotspots in the most PCB-contaminated sector of the Hudson River ended in mid-October for this year, and probably for next year. This year’s effort failed to complete its PCB removal target, leaving square miles of dredged river surface to release recently-mobilized PCB to the air. An essential public and environmental health measure is to maintain a fixed array of air monitors to quantify airborne PCB levels and variations over the coming months and years. Such information is essential for determining the wisdom and possibly the manner of completing Phase I and entering Phase II of the dredging project. However, GE’s final, EPA-approved Quality Assurance Project Plan (QAPP, GE 2009) fails to establish such a fixed array of monitors:

“Air monitoring for PCBs will be conducted employing samplers operating for 24-hour periods continuously during dredging activities and operation of the sediment unloading and processing facility to verify assessment and demonstration of achievement of the air quality standards for PCBs. Such monitoring will be conducted at locations along the dredging corridor (using two portable locations at each general dredging area) and around the sediment unloading/processing facility (four permanent locations). In addition, monitoring will be conducted throughout the remediation program at a permanent background station situated away from the river upwind of the Phase 1 dredge areas and the unloading/processing facility. Further, a meteorological station will be established at the processing facility to provide meteorological data for use in this air monitoring program” [pages 183-4, emphasis added].

As stated in the QAPP (above), monitoring airborne PCB along the dredging corridor will occur only during dredging activities. That constitutes a two-fold deficiency. First, it fails to put in place a fixed array of air monitors, relying instead on just a single portable air monitor on each shore of the river opposite each dredging unit. Second, as the dredging units progress downstream, they are followed by the air monitors, which therefore cease to monitor the air upstream, where PCB just was mobilized. Yet, as long as PCB-bearing sediments remain on the river bottom (probably decades), PCB transfer from water to air will be a long-term process, and may not reach peak or typical transfer rates immediately. Air monitors must remain for months if not years to quantify airborne PCB levels and variations, characterize the transfer process, and ultimately protect the health of the public and the environment.

The reality is that monitoring for airborne PCB was entirely inadequate during Phase I of the Hudson River dredging project. Its inadequacy increased with each increment in the dredged area of the river, as the portable monitors withdrew downstream with the dredges, and as the river surface area releasing PCBs to the air increased. The inadequacy of airborne PCB monitoring ultimately will progress to complete failure if portable monitors are withdrawn from service at the end of the active dredging season, leaving only four fixed monitors arrayed at the sediment processing facility. EPA should require GE to put in place a fixed array of samplers to overcome the deficiencies documented above.

Literature Cited

GE RAM QAPP. River PCBs Site, Phase I Remedial Action Monitoring Program, Quality Assurance Project Plan; Final. Prepared for General Electric Company (GE; Albany, New York) by Hudson Liverpool, New York, Anchor QEA, LLC; in conjunction with Valley Forge, Pennsylvania, Environmental Standards, Inc.; Syracuse, New York, ARCADIS; 344 pages, i.p., May 2009.

Copyright © 2009 by The Center for Health Risk Assessment and Management, a Division of RAM TRAC Corporation