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LCP Chemicals Site Marshlands Feasibility Studies
April, 2002

Overview

The Glynn Environmental Coalition received for review the Operable Unit 1 Upland Soils and Estuary, Remedial Investigation/Feasibility Study Report Volume 1 LCP Chemicals, Brunswick, Georgia, and the Feasibility Study Addendum OU-1, both dated March 2002. These documents provide several scenarios for treating the marsh and uplands. Over the past few months a variety of documents related to risk assessment, and potential cleanup, were received for review. Although no other information has been released by the Environmental Protection Agency, a public meeting on the remedies in the near future appears likely.

The LCP Superfund site was the target of an emergency cleanup (Remedial Action) to remove sources of contamination from groundwater, the upland (dry) portions of the site, and toxic material and sediment from the marsh. That cleanup, which included removal of several manufacturing buildings, was intended to halt the spread of contamination from the marsh to the Turtle River. The point of the current Remedial Investigation is to return the marsh to natural productivity and the uplands to safe usefulness. Groundwater cleanup falls under a separate Feasibility Study. The documents provided at this time are for the marsh and uplands. This review focuses on the potential treatment scenarios for the marsh.

Although large amounts of toxins were removed during earlier cleanups, the marsh remains contaminated. The LCP marsh is actually still a source of Mercury and Lead contamination in the Turtle River estuary. The marsh is toxic on several levels, but primarily direct exposure through ingestion, and through the food web to animals that use the marsh. All animals that use the marsh are potentially endangered, including human trespassers that swim or fish in the marsh.

Site Description

The LCP marsh is about 480 acres spanning from the eastern edge of the Turtle River to the LCP shoreline. Purvis Creek is a tributary of the Turtle River flowing through the LCP marshes. An east-west causeway, running from Purvis creek to the shoreline, divides the marsh into northern and southern sections. The LCP ditch runs parallel to the causeway on the southern side. Based on the type and extent of contamination, the marsh is artificially divided into four “domains.” Domain 1 includes the entire southern shore of the LCP uplands south of the LCP ditch. Domain 2 starts immediately west of Domain 1 running westward to Purvis Creek. Domain 3 begins at the shore north of the LCP ditch and runs westward to Purvis Creek. Domain 4 is on the western shore of Purvis Creek adjacent to Domains 2 and 3.

Extent of Marsh Contamination

The marsh is contaminated with a combination of Mercury, Lead, and Aroclor-1268 (PCB). The cleanup scenarios focus on Mercury and Lead since cleaning up these chemicals will clean up PCB as well. For all practical purposes, Mercury above 1 part per million covers all of Domains 1 and 2 and much of Domains 3 and 4. Lead above 30 ppm also occurs in large portions of all four zones. The northern areas—including Domain 3 and portions of Domain 4-- are generally less toxic than the southern areas.

Action Level

The term “Action Level” is intended by Superfund law to be a chemical concentration triggering a cleanup response. Anything above the action level is supposed to be remediated, however, the term “action level” has lost it’s meaning at Region 4 EPA. Merely watching waste forever is often considered a remedy at Region 4. The main goal at this site should be to get the Mercury levels to or below 1 part per million (1 mg/kg) in marshland soils and sediments. That level would restore the marsh to productivity. In our consideration of the proposed remedies, we used 1 ppm Mercury as the benchmark. Essentially, we tried to answer the question: could the proposed remedy achieve 1 ppm Mercury as a direct result of the cleanup, or through natural processes within a few years?

Marsh Remediation

Cleanup scenarios fall into several categories ranging from no action to complete removal. “Scenarios” are broad plans presented in outline form, which include: areas impacted, costs, and potential benefits. All plans have to meet Superfund criteria of cost, implementability, short and long term effectiveness, legality, and state and community acceptance. The Feasibility Study (FS) received for review does not indicate which of the scenarios EPA and the responsible parties favor.

“No action” scenarios are included, but not actually considered for a site that is this toxic. At the other treatment extreme is complete removal of all affected areas of the marsh. Driving the cleanup are the “action levels” of toxins remaining. At this site, the toxins are Mercury, Lead, PCB, and organic chemicals. The marsh portion of the emergency Remedial Action cleanup only removed Mercury levels above 25 parts per million. While this reduced the amount of Mercury in the system, it had little overall effect on the toxicity of marsh soils. There is still enough Mercury to maintain toxic levels well above the threshold of 1 part per million. Mercury and Lead are elemental. They cannot be broken down into harmless materials. Some forms of Mercury and Lead are less toxic, but processing the soils will destroy the marsh. Likewise extracting toxins is far more expensive than simple removal and replacement of the entire soil. If the pollutants in the marsh were organic, even persistent organic toxins, there would be options for natural “attenuation” (breakdown), however, elemental poisons are best removed and stored away from biota.

Marsh Cleanup Plans

The documents make extensive use of tables, computerized plots using a variety of statistical methods for average chemical exposure, and engineering algorithms. We summarize the results here using the information to cover three broad questions.

What types of cleanup options are being considered?

Option 1 consists of excavation, landfill disposal of contaminated wastes, and backfilling with clean fill. This option is only considered for upland/near shore locations. The removed materials would require dewatering before transport to a landfill. Option 2 consists of various “containment” strategies. In this scenario, the toxins are covered with fabric, soil, or concrete caps. We note that capping options in the FS addendum are called “aesthetically obtrusive,” meaning “ugly.” 

Both Option 1 and 2 destroy the existing marsh. Capping removes the marsh from contributing to the ecosystem as foraging or reproductive habitat. Removal and backfilling still destroys the existing marsh. The sediment would need to be replaced, and plants would have to be brought in as well. It would be decades before the replacement marsh would be a productive fishery habitat. In both scenarios, the existing marsh is destroyed to render it harmless.

Page 28 of the FS addendum presents another “concept” that was not modeled. This concept would utilize up to 200 acres of the LCP marsh site as a dredge spoil area by the US Army Corps of Engineers for Port of Brunswick navigational channels. Costs and compliance with Superfund criteria were not discussed, only that a dredge spoil containment cell would serve as an effective cap to isolate Mercury and Lead. No mention is made of the potential for material dredged from the Turtle River to also be contaminated with Mercury and Lead. The concept indicates that only the LCP ditch and 13 acres previously remediated would remain. It is very unusual for a Feasibility Study to include extraneous “concepts,” so it seems likely that converting the marsh to dredge spoil impoundments is planned. The inclusion of this “concept” with no details is a cause for concern with this FS.

How much of the marsh is targeted for remediation?

The proposals use a complex method of estimating the mass of Mercury, Lead, and PCB remaining in the marsh. The plans then evaluate engineering methods for the cost in dollars versus the impact on mass of each chemical. Depending on the amount of money spent, the cleanup would remove or cap between about 10 to 80% of the area of the marsh.

All of the ecological baseline risk assessments pointed to a safe level of Mercury occurring at 1 part per million in surface soils and sediments. Above that level of toxicity marsh recovery will take many years, likely hundreds of years for amounts above 10 parts per million. Unlike organic chemicals, elemental chemicals can be difficult for natural systems to purge. We would have preferred to review additional options that brought the less contaminated areas of the marsh more quickly back to safety and productivity.

How do these options meet the cleanup criteria?

All of the options are ‘implementable” since they depend on moving soil and sediment. Only remediation of the entire marsh to 1 part per million Mercury is immediately compliant with all appropriate laws and regulations. For scenarios that treat smaller portions of the marsh the long-term effectiveness criteria is met by assuming the remaining areas can recover in time, so long-term monitoring is included in those scenarios. Short-term effectiveness-- not causing additional harm during the cleanup-- can be met. State and community acceptance is still to be determined.

Complete removal and restoration provides the greatest benefit to the Turtle River estuary, and is also the most expensive. Complete capping of the marsh provides the same margin of safety as complete restoration, but without the benefits of returning to a productive ecosystem. Capping will also be ugly; aesthetics is not a superfund requirement, but may affect state or community acceptance.

The various half-measures that excavate or cap some areas, and leave other areas with significant contamination, may not be long-term effective or safe. The plans call for trying these options along with long-term monitoring to see if the areas attenuate, with re-treatment if nothing happens. We note that no timetable for determining success or failure was included.

In one sense, even the most expensive scenario is cost-effective since the marsh and estuary would again become productive habitat, and the ban on consuming seafood would likely be lifted. However, EPA considers only cost-effectiveness to the responsible party, not the overall cost-effectiveness, so the best scenario is unlikely to ever be chosen.

LCP Marsh: “Worse-case” outcome

Over the past several years, the LCP marsh was extensively studied. There is overwhelming evidence at this point that contamination of the marsh is a “worse-case” outcome, in the sense that the entire marsh, not just portions, are affected. It was everyone’s hope that major areas of the marsh would be found to be safe. All of the “cost-effective” scenarios offered in the FS involve permanent toxic waste reservoirs in the marsh. Since the majority of the marsh is contaminated, the only scenario that is a true cleanup involves complete removal of the existing marsh.

A scenario that should be considered, but was not presented in the FS, is full restoration as wetlands of the less contaminated northern areas of the marsh; southern shore treatment and stabilization; and removal of contaminated portions of the southern marsh areas to form a basin. Leaving portions of the marsh as a basin would reduce costs since restoration in those areas would not occur. The basin could be developed for low impact non-polluting commercial marine uses. Obviously the loss of so much marine fisheries habitat would be unfortunate, however, perhaps the losses could be offset in some way through expansion or protection of other wetland areas. It is likely much of the Turtle River drainage would improve once the LCP marsh is no longer a contamination source. This is an option the community and responsible parties ought to explore. It is an alternative that brings the Turtle River estuary back into productivity as quickly as complete removal and restoration, or complete capping, and allows the shoreline and uplands areas to benefit the community. Remediation should also include the groundwater seeps, and the area over the CBP (Caustic Brine Pool) would need to be addressed.

Recommendations to the Community

Capping the marsh as a permanent landfill or converting to a dredge spoil area should be rejected outright. Both concepts destroy the marsh without significantly decreasing the amount of toxic chemicals. Neither concept returns the marsh to productivity. In fact, the dredge spoil concept may actually increase toxins in the LCP marsh if the Turtle River dredge spoils are contaminated.

The Domain system used in the FS is awkward since it is an artificial portioning of the marsh into construction zones, rather than a logical treatment of the marsh as an ecosystem. Large portions of Domains 3 and 4 contain Mercury contamination less than the 1 part per million threshold. The areas of between 1 and 5 ppm are along tributaries of Purvis Creek. Further, the areas above 5 ppm Mercury or 30 ppm Lead are near shore. The toxic waste deposits in Domains 3 and 4 that are near shore, or near Purvis Creek, should be fully rehabilitated by removal, backfilling with clean soil and replanting of marsh grass. That would restore a substantial portion of the marsh to productivity. Sections of the marsh in Domains 1 and 2, and the southern portion of Domain 4 show a greater percentage of contaminated soils. No areas of Domain 1 are below 1 ppm Mercury and only a few spots in Domain 2 show Mercury below levels that threaten wildlife. With the proximity to the deeper water of Turtle River, removal of portions of the southern marsh for maritime commercial use is feasible, and could be a better choice than building permanent waste disposal cells.

At this time, the LCP marshes can be considered nonproductive as habitat. The levels of pollutants are high enough to assume the marshes are hurting fin and shellfish. A seafood ban remains in place for the foreseeable future. Accordingly, the LCP marsh is harmful to wildlife and provides no benefit to the citizens of Glynn County. Even remediation of those areas above 10 ppm Mercury would leave more than half of the marsh unsafe for wildlife and trespassers. Clearly, all half-measure cleanup scenarios fail to improve the marsh.

Capping contaminated areas would reduce the toxin mobility, but would destroy the marsh as useful habitat. The only benefit to capping is to allow the balance of the Turtle River estuary to begin to recover, but the marsh itself is destroyed and replaced with a landfill.

The feasibility scenarios are based solely on a cost-limiting approach and-- with the exception of complete restoration—fail to benefit the marsh or the community. We recommend the community decline the proposals as written and request additional feasibility scenarios that focus on complete restoration of the less contaminated northern and western areas of the marsh, and separate plans for more heavily impacted southern areas. 

 

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/eco  on the Internet.

 "This project has been funded wholly or partly by the U.S. Environmental Protection Agency under Assistance Agreement Number 1-994850-01-0 to The Glynn Environmental Coalition, Inc. The contents of this document 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."

 

   

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