Monday, October 26, 2009

FIRESIDE CHAT: Hudson River PCB Dredging and Cooling Tower Air Monitoring

For more info:

The presence of cooling towers constitutes a special circumstance involving increased potential for dredging-mobilized PCB to enter the air from Hudson River water. This concern was ignored in GE’s final, EPA-approved Quality Assurance Project Plan (QAPP, GE 2009). The QAPP fails to establish an array of fixed air monitors at cooling towers or at any other key locations, except for four air monitors at the dredge spoil processing facility remote from Phase I dredging activity.

The concern about cooling towers was explicated clearly in a fully peer-reviewed article by myself and co-author Dr. Uriel Oko, published in the Cambridge University Press journal Environmental Practice in 2007. This article is available online, at no charge, at To obtain it, go to Publications, and click on 34, or just go directly to the article at,%20in%20Acrobat/34%20PCB%20Dredging,%20EP%209(2)%202007.pdf.

The basis for concern is fourfold. First, cooling towers draw cold water from the river, including dissolved, colloidal, and suspended contaminants such as PCB recently mobilized by dredging. Second, the water enters cooling towers only after first having been heated by perhaps 100° F by industrial processes that used the water to control temperature to within acceptable limits. Third, hot water in cooling towers may release PCB into the air at an accelerated rate (more than 10 times the rate of emission from cold river water) because they are open to the atmosphere at the top, allowing the water to cool before release back into the river. Fourth, cooling towers are located in the vicinity of populated areas along the river, because that’s where employees and their families live.

Concern about PCB release from cooling towers might have been ignored by GE and EPA, but not by the New York State Department of Environmental Conservations (NYS DEC). Dr. Oko and I expressed concern about this issue in connection with permitting of the Bethlehem Energy Center (BEC). We requested that the cooling tower rely on air cooling rather than water cooling. Accordingly, the permit for the facility required an expensive ‘hybrid’ cooling tower, which can operate on air or water. In the event of PCB mobilization by dredging, the cooling tower could be switched to air cooling to avoid intake of river water containing elevated levels of PCB. This requirement represents ‘voting with your feet’, that is, giving credence to the concern by doing something about it.

Now, GE and EPA should do something about the credible concern about increased PCB release to the atmosphere by industrial cooling towers that rely on water (including all or nearly all cooling towers except BEC’s). GE and EPA should place water samplers and air samplers at cooling towers. The water samplers should monitor PCB levels entering the cooling towers, and the air samplers should monitor airborne PCB emerging from the cooling towers. These monitors should remain in place until the dredging project is completed, and afterward to keep track of the impact of the project and impact mitigation over time.

As a final justification for the measures that I am suggesting, I would like to broaden my perspective. The discipline of health risk assessment evolved from being embedded as part of environmental impact assessment. Indeed, health risk assessments (HRAs), before evolving into stand-alone documents, were embedded as part of Environmental Impact Statements (EISs), which first were required under the National Environmental Policy Act (NEPA) enacted four decades ago, in 1969. Time has allowed retrospective evaluation of the results of NEPA and its State equivalents, State Environmental Quality Review Acts (SEQRAs). Possibly the greatest concern elucidated in such evaluations has been that projects have been approved one by one, resulting in cumulative impacts that no single EIS could have predicted. To overcome this concern, NEPA and SEQRA reformers have suggested undertaking studies of the accuracy of EISs (and HRAs) with respect to the impacts that they had predicted. In the case of Hudson River PCB dredging, this suggestion would include monitoring air, water, and biota along the Hudson River for an extended period beyond completion of the dredging project, to assure that impacts predicted to be within an acceptable range actually were acceptable. For these reasons, in addition to other technical reasons stated above, EPA should require adequate monitoring both during and after project implementation, but it conspicuously has required neither.

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