Issues Weak Dredging Study
Help Clean The
River and Bay!
|June 11, 2007
The National Research Council recently issued a report saying, "Sediment dredging has fallen short of achieving cleanup goals at many contaminated sites." Many local news media interpreted this report as supporting the EPA and DNR proposal to cap PCB hotspots in the Fox River. As usual, they've gotten it wrong.
In their news release, the NRC cited 8 basic conclusions:
1. "It has not been demonstrated that dredging has reduced the long-term risks the sediments pose to people and wildlife."
This is an amazing blanket statement until you realize the NRC is talking about MEASURED results AFTER a cleanup is done. Most of the major sediment cleanups are still underway and only partially complete, so of course the agencies couldn't have demonstrated long-term risk reduction. We're still in the short-term. It would be impossible to detect any effect on the Fox River yet.2. "Many dredging projects have had difficulty meeting short-term goals for reducing pollution levels."
No kidding. River sediment clean-ups are difficult and time-consuming. Also, dredging is bound to leave some residue that must have time to be buried or disperse. Short-term results should not be expected.3. "Whether dredging alone can reduce long-term risks was difficult to determine at many sites because of inadequate monitoring data and other limitations."
Monitoring is important, both before and long after. But it's important to not put too much emphasis on interim monitoring during the cleanup process or on short-term results. Long-term results are far more important. Also, if monitoring data is lacking, how can the NRC say "sediment dredging has fallen short of achieving cleanup goals at many contaminated sites?" It sounds like the NRC is stretching to make significant statements based on very little data. The NRC seems to have a hidden agenda here.4. "Dredging's ability to achieve cleanup goals depends on a site's characteristics."
Of course.5. "Dredging is effective at removing contaminated sediment mass permanently from the environment, the report says. But removing mass may not be enough to achieve desired cleanup levels or long-term goals for reducing risks, because dredging inevitably leaves residual contamination behind."
The "residual" issue is highly overblown as a risk, unless the initial cleanup standard deliberately left a large mass of residual contamination behind. It's important to make a distinction between a light dusting of drifted residuals just on the sediment surface and a thick layer of 6" or 3 feet of 1 ppm PCB sediment left behind deliberately. If long-term goals aren't being met, it's probably because the original dredging program was too limited. More contaminated sediment should have been removed in the first place.6. "The dredging process releases contaminants into the water, which in the short term can have adverse effects on fish and other aquatic animals and could potentially raise health risks in people who consume them."
Of course there will be a small amount of pollution released during dredging, but the use of a hydraulic, vacuum-style dredge, or closed environmental dredge, minimizes this release. The NRC is also ignoring the fact that the laying of caps will also cause a significant release of contaminants. The capping process could be just as messy as dredging.
Keep in mind that the Fox River sediments are now releasing hundreds of pounds of PCBs each year, with no dredging at all. If dredging elevates that release slightly in the short-term, it must be balanced against the HUGE drop in releases a few years after dredging is done. Once the PCB mass is gone, the fix will be permanent. With capping, we would have to worry permanently about future leaks, recontamination, and health risks due to cap failure.7. "Dredging remains one of the few approaches available for cleaning up contaminated sediments. EPA should continue to consider its use among other methods. In locations where buried contaminated sediments could be dislodged by storms, for example, dredging the sediments to prevent them from being transported may reduce risks. If dredging is used, planners need to recognize that residual contamination and releases of chemicals into the water will invariably occur; they should estimate the effects of these processes in advance, and employ best practices to minimize them, the committee said. Using a combination of methods should also be considered, particularly if a site has any characteristics unfavorable to dredging."
Seems obvious. It appears the NRC is saying that dredging should be used on the Fox River to prevent contaminated sediments from being dislodged by storms, floods or ice erosion, but the wording is vague enough that the DNR and EPA would undoubtedly interpret it differently.8. "To help ensure that megasites with contaminated sediments are cleaned up as effectively as possible, EPA should centralize resources, responsibility, and authority for these sites at the national level, the report recommends. Such a shift would help the agency make sure that monitoring is adequate and that adaptive management and best practices are followed."
This is problematic. While we're unhappy with the performance of the Wisconsin DNR on this issue, we're equally unimpressed with the EPA's performance. And while we agree that national standards are needed and would be preferable, this is only true if they are HIGH standards, not the lame leadership we've seen to date from the federal government. We would not want to see a federal program which is only the lowest common denominator of all the weak state programs in this country. We would also hate to see all the responsibility placed under the political control of rabidly anti-environmental politicians like George Bush and Dick Cheney.What About Capping?
In their news release, the National Research Council raised many concerns about dredging, but they failed to acknowledge that THEY HAVE NO DATA on the longterm effectiveness of the alternative sediment remediation method, the so-called "permanent caps" proposed for the Fox River over large PCB deposits. There have been no comparable caps placed anywhere in the world in a large flowing river at a northern latitude like ours, exposed to annual freeze-thaw pressures and ice scouring. The NRC seems to be favoring capping instead of dredging, without any comparable data requirements or analysis of capping effectiveness.
The National Research Council report is not new information, not well summarized, clearly one-sided, and seems to be politically timed to serve the polluters' interests, not the public's interests.
This is a political report.
CONTENT BY: Rebecca Leighton Katers
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