These comments are on the latest "Ecological Risk Assessment of the Marsh Area of the LCP Chemical Site in Brunswick Georgia" dated January 1998 (the "ERA"; AlliedSignal). Previously, the LCP marsh was the subject of several ERAs attempting to gain an understanding of pollution in the marsh. These and previous studies have measured contamination in the plants, animals, soils and waters of the LCP marsh to develop a picture of the distribution of pollution and gauge the effect of pollutants on the marsh ecosystem.

A few conclusions can be fairly drawn at this point in time. Most importantly, the former LCP plant site is no longer discharging new toxic waste into the marsh either from plant operations or from contaminated runoff from past operations. So, at this point the marsh is as bad as it will ever be. The second conclusion is marsh animals and plants are all affected by the toxins mercury and PCB. There is ample direct documentation of toxins in the water, mud, and food chain; and sufficient anecdotal evidence of a weakened ecostructure for continuing public concern over the long recovery period.

The purpose of any marsh environmental assessment is two-fold: provide outcome-based guidance on further remediation within the marsh, and provide local government and concerned citizens an efficient model of the likely future conditions in the marsh after cleanup. This latest assessment does not accomplish either of those goals.

The LCP marsh is a 480-acre region bordering the former LCP chemical site in Brunswick Georgia. LCP contaminated the region with an outfall of mercury and polychlorinated biphenyl (PCB) from manufacturing operations. Prior to LCP, the marsh received contamination from paint blending operations and from crude oil refining. The marsh is part of the Turtle River estuary. The Environmental Protection Agency is overseeing cleanup efforts in the marsh. The first work involved dismantling the plant and removing onshore materials that were contaminating the marsh. While that was underway several studies examined the marsh for toxin distribution.

From the outset it was understood that there were only two outcomes for the LCP marsh: totally destroy it in an effort to remove all pollutants, or perform some form of environmental engineering and wait and see the results. The system is large and complex; there are pollutants (such as PCB 1268) that are rarely encountered in the environment, and there is a poor literature base to speculate from.

There have been several environmental studies performed on various areas of the marsh. The earliest report, the "Sprenger report" (EPA, 1997 and earlier drafts) found a significant impact to plants and animals using the marsh. The current AlliedSignal ERA contains a number of references to meetings and remediation plans that have not been made available to the Glynn Environmental Coalition (GEC). Overall, the impression is that the new modeling was aimed at refuting the findings of the earlier Sprenger reports.

Specifically, page 7-23 of Volume 1 concludes: "…examination of chemical risks indicates that upon completion of the ongoing removal actions, there are no potential risks for any assessment endpoints except for exposure to piscivorous mammals…". Unfortunately, The GEC received the marsh Risk Assessment, but not the plans for any "ongoing" removal actions. Without knowing what specific removal actions are planned it is difficult to accept this statement.

The current ERA modifies several of the Risk Endpoint Assessments used in the earlier Sprenger report. All of the modifications have the effect of reducing the estimated toxic effects on marsh animals. Endpoint Assessments are basically the overall effect of a chemical on a local population.

There are five environmental scenarios in the model using "indicator" subpopulations. 1) Health of all water reptiles is gauged by examining populations of diamondback terrapins. 2) Raccoons are considered the indicator for all terrestrial "omnivorous" mammals (animals which eat a broad spectrum of food types, such as plants, insects, and other animals) that forage in the marsh. 3) The health of birds in general is estimated by combining effects on the marsh wren and clapper rail. 4) Fishery resources are examined in general by looking at effects on small crabs and other invertebrates, and small minnows that are used as food. 5) Finally, the river otters are the indicator species for all "piscivorous" mammals (animals that only eat fish and shellfish). In each case the various toxic exposure influences, such as diet and surrounding chemical concentrations, are weighed against any observed impairment in the indicator animal.

The earlier Sprenger report found significant toxic effects on most of these indicator species, thus indicating that the marsh as a whole was unhealthy. However, this latest report by AlliedSignal argues that the high levels of mercury and PCB do not impact marsh wildlife.

Neither the Sprenger report nor the Allied Signal ERA had sufficient toxic effects data for marsh turtles to effectively model exposure. Field observations indicated reduced egg clutch size, wasting disease and, possibly, developmental defects. Further, turtles had elevated tissue toxin levels, and their food supply was contaminated. But there is a lack of scientific data that could be used to correlate the effects of either major toxin to the general health of the populations of aquatic reptiles. The correct conclusion is "no conclusion can be drawn," not the "no risk" conclusion drawn here. The diamondback terrapin is, basically, a poor choice for these studies.

The modifications to the hazard index regarding raccoons are particularly lacking in objectivity. The authors cite a study of raccoons on St. Catherine’s Island, Georgia in lowering the area use estimates for marsh raccoons to 30 percent of their home range. Their argument that raccoons vacate during high tide is dubious since raccoons are frequently observed swimming in Atlantic coastal marshes and raccoons that utilize a marsh for foraging are rarely seen foraging on land. This change to the model is based on the ERA authors’ opinion, but it is a change that converts the raccoons from a threatened species to one that is unaffected by marsh pollution.

The rationalizations for effects on marsh birds follows a "divide and conquer" strategy to derive lack of risk. For the clapper rail and marsh wren the authors used average values for the entire marsh rather than the earlier station-specific results. As a result the current study derived potential exposure levels 1/7^th to 1/10^th of the previous Sprenger reports. This is a very biased modeling approach, and it is fair to blame the EPA for such poor guidelines on modeling element selection.

The fisheries resource studies consisted of a variety of laboratory and field tests ranging from comparisons of mud-dwelling crabs between the LCP marsh and a control marsh, to setting out trays of oysters in different portions of the marsh to see if they were injured. Some of the studies were inconclusive, but overall the marsh did prove to remain very productive in spite of the heavy concentrations of pollutants. Unfortunately, the study’s authors see the productivity of the fisheries resources as "proof" that no further cleanup is needed. The real point is that these lower trophic levels still have high levels of mercury and PCB which contribute, via bioaccumulation, to high tissue levels elsewhere in the food chain; and cleanup is necessary to reduce these levels to background.

Despite all of the model manipulation the category of piscivorous mammals, as represented by the river otter, still showed unacceptable risk. Unless and until the actual levels of mercury and PCB can be brought to near background the marsh should be considered an environmental hazard and the subject of continuing remediation efforts. It should also remain closed to all humans.

Ironically, if the fisheries resources of this marsh were less productive the marsh would be safer for marine life. The plentiful availability of low food chain crabs, mollusks and minnows assures that higher animals forage predominately in the most contaminated regions. Since the food chain is contaminated bioaccumulation increases the levels of toxins in all organisms across the marsh.

A guess is that severe injuries are not observed in animals mainly due to the lack of harsh winter weather in the southeast Georgia climate. The animals never become highly stressed or malnourished; consequently, they never have to rely on fat reserves or greatly extend their foraging range to survive. The expected injury from the high toxin body burdens then fails to manifest in acute symptoms.

However, the point of any cleanup is still to reduce the body burden toxin levels to background. Sufficient data exists on tissue levels to guide a cleanup. This Risk Assessment merely "tweaks" the model making the data values look smaller in order to justify a limited cleanup and monitoring program.

The study’s authors carefully selected the modeling systems that show the lowest impact of their pollution on the marsh. Neither LCP nor AlliedSignal own this marsh. This is not a case of compliance within the metes and bounds of a privately held commercially developed property. This is severe contamination of a public resource. The public can and should expect that science and logic dictate remediation for a rapid cleansing of the marsh to background levels.

At this site the science says that marsh biota are carrying high body burdens of toxins. Whether there is a mass killing or not is irrelevant. The point of any cleanup is to reduce the chemical body burdens of marsh species. The EPA is urged to take a long view with respect to this ecosystem. While it may be practical to return the upland portions of the site to commercial use in the near future; this marsh will require long-term monitoring and extensive remediation to promote recovery.

Written by R. Kevin Pegg, Ph.D.; edited by Dr. Mary S. Saunders. Copies of the newsletter are available from the GEC, at the Glynn County library, or at www.NucleicAssays.com/tags on the Internet.

[ Back ] [ Home ] [ Up ] [ Next ]

TECHNICAL ASSISTANCE REPORTS    "These projects have been funded wholly or partly by the U.S. Environmental Protection Agency under Assistance Agreements. The contents of these documents do not necessarily reflect the views and policies of the U.S. Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use."  

Send mail to issues@enviro-issues.net with questions or comments about this web site.
Copyright © 1999, 2000, 2001, 2002 Nucleic Assays Corporation