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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.
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P. O. Box 2443