TAG reports: Volume 1, Number 3; July,1999
Cleanup Events Overview, Part 3:
Overview
Although high concentrations of pesticide are found throughout the Terry Creek Disposal Area Site in Brunswick, Ga., it appears the Environmental Protection Agency (EPA) is not planning extensive treatment. Aside from localized dredging operations, documents related to the site cleanup received by the Glynn Environmental Coalition (GEC) for review seem to be a collection of simplistic studies designed to show that toxaphene can be left untreated in the Brunswick environment.
Toxaphene Cleanup
The banned pesticide toxaphene is a biocide, mutagen, and carcinogen. In other words, it kills or causes cancer, depending on the dose. There is no ambiguity over this; toxaphene is dangerous. Estimates are that toxaphene was dumped into the Dupree and Terry Creek marshes at rates of up to 300 pounds per day during the more than three decades of toxaphene production in Glynn County. This results in, perhaps, 1,000 tons of toxic toxaphene dumped in the Glynn County marshes.
Toxaphene is a complex mixture of over a hundred different chemicals, with a combined “half-life” or time to break down, of about 10 years. Some of the chemical components break down quickly, some chemicals dechlorinate to other forms of toxaphene; some of the chemicals stick tightly to particles and persist for long periods, while some are soluble in water and dilute promptly. Generally though, about 10 years is the recognized time for toxaphene to degrade to harmlessness. This means, for example, of the up to 55 tons dumped just in the year of 1969 alone (around the time EPA was created) nearly 6 tons of it are still hanging around- somewhere- today, 30 years after it was dumped. “Somewhere” includes the water, mud, muck, soil, plants, worms, snails, crabs, fish, turtles, birds, and mammals of the Terry and Dupree Creek marshes.
Since the mid 1970’s very little new toxaphene has been dumped into the marsh. Unfortunately, very little monitoring was performed during the interim period. Also, over the past few years EPA has needlessly changed the toxaphene measuring technique several times, so the data produced over the past decade cannot easily be compared. This means we do not really know if toxaphene levels in the marsh are declining, stable, or increasing. Ideally, we would have several sampling sets taken at intervals, using similar techniques, so researchers could "extrapolate" (make an educated guess) the toxaphene contamination trend at this site. Actually, EPA’s data is so poor it is not feasible to determine if the Terry Creek Site is a source for continued contamination to other areas of the Georgia coast.
Although there are five areas of toxaphene contamination identified in the Final Site Inspection Study, only one of those areas is presently designated for any type of treatment. Site repository documents identify four spoil deposition areas with elevated toxaphene. Area 1 is the Main Dredge Spoil Area, a rectangular region in the center of the marsh built over several decades with both uncontaminated and toxic dredge spoils. Area 2, the Riverside Dredge Spoil Area, is a region along the Back River where elevated levels of toxaphene have also been found. Toxaphene is also found in a residential housing tract near Torras Causeway, called Area 3. Area 4, also called Carter’s Island Spoil Area, has elevated levels of toxaphene. A fifth area of contamination consists of the banks and streambeds of the Dupree and Terry Creek streams. Based on the current set of documents, the Hercules Outfall ditch, where the contamination originated, seems to be included in the Terry and Dupree Creek streams.
The documents provided to the GEC for review (Removal Work Plan, Terry Creek Site; March 1999) indicate a removal action for only one area. The Plan indicates some sediment removal from the “Y” shaped region formed by the Outfall Ditch where it runs from Hercules to the confluence of Terry and Dupree Creeks. The Plan gives few details; however, it appears that only the top few inches of sediment is to be dredged. Other areas along the Back River or near Carter's Island seem not targeted for cleanup. The contaminated residential areas are not considered for treatment.
There is no information in the documents on the target cleanup level to be used in the Removal Action. The cleanup level determines the depth and breadth of any action. The lower the target cleanup level, the more areas will be treated. If the cleanup level is set very high, there may be only a trivial amount removed. Therefore, since the target cleanup levels were not provided, it is not possible to gauge how extensively the areas will be cleaned up.
No information has been provided on the technology to be used in the cleanup operations, and no health and safety plan was provided. No information on control of toxic silts generated by the Action, and no information on any treatment after removal of dredge spoils, was provided. Also, no information was provided for the final placement of any dredged materials. In the past, dredging operations have placed contaminated materials within the Main Dredge Spoil Area (Area 1). Hopefully, that will not be the case in this removal.
Baseline Monitoring Studies
In addition to the Removal Action there are several studies designed to “prove” toxaphene is safe for local marine life. Since the toxicity of toxaphene is well known, it is not clear why these studies are needed.
Oyster, Crab, and
Fish body burdens:
"Body burden" describes the total amount of pesticide found in the tissues of living organisms. Previous studies have found toxaphene and "toxaphene-like" compounds in local animals. Since toxaphene is a mixture there are instances where some, but not all, of the individual toxaphene compounds are found in an animal. However, “toxaphene-like" is still toxaphene, just not the technical grade toxaphene used in the calibration standard.
The overall idea in this study is to place clean animals in contact with site sediment and water to see if they accumulate toxaphene. It has been proven that toxaphene “bioaccumulates.” Bioaccumulation and biomagnification are processes where animals have levels of a chemical higher than the surrounding water or sediment. This can occur through the food chain with each level (“trophic” level) showing higher and higher levels of a toxin. Essentially, body tissues, such as fat tissue, can hold higher levels than would be found in just water.
This study uses animals transplanted from a clean area. The study plan provided for review did not indicate how long the animals would be in the environment, but obviously it could take many years for an adult animal to reach levels similar to an animal reared from eggs in the environment. Also, toxaphene can be difficult to measure in biological samples, and EPA/Hercules often uses biased methodology for toxaphene testing.
Further, there is very little data to indicate what environmental levels are harmful to these species. In the unlikely event that the short duration body burden study found toxaphene, there would be no direct method of drawing a conclusion from the data. Overall, these studies have little scientific merit.
Direct Toxicity
Testing:
A previously published paper by an independent laboratory found that Terry Creek grass shrimp had reduced hatching and genetic damage from toxaphene in the marsh. EPA/Hercules are challenging that study and performing a new study using laboratory exposed shrimp. It is not clear what EPA/Hercules hopes to
achieve with these studies, since the planned artificial laboratory system will not duplicate the generational or biomagnification effects that exist in the marsh. The reason stated in the study description seems poorly developed. EPA/Hercules argues that the grass shrimp of the published study may have been exposed during their life spans to higher concentrations than the amount found in the soils during the study. Of course, it is just as likely that shrimp were in water that had lower concentrations. Generally, the published report is fair; this proposal is not. Note, for example, that the laboratory system will apparently be fed with uncontaminated food, which is not the case with an open-environment study. Since the animals used have nonliving exoskeletons, this study actually measures short-term toxaphene uptake across shrimp gills, not toxaphene accumulation from environmental exposure.
Without more information on the study’s model and goals, it seems to be a highly biased and unscientific
view of the actual marsh conditions. If the purpose of this study is to correlate with the body burden levels described above, it is wasted effort, since the animals used in the two studies are completely different and the results incomparable.
Conclusions
It appears, from the documents given, that EPA has jumped to the conclusion that very little treatment is necessary. Speaking in general terms, if the cleanup level is set fairly high, and the EPA continues to use the poor under-reporting methods for toxaphene analysis, then this Removal Action will be “too little, too late” to really provide protection for the marsh and the fisheries that depend on it.
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