TAG reports: Volume 3, Number 1;
March, 1994
009 Superfund Site: Review of the Consent Decree, In situ experiments, and Neighborhood Testing Plan
Overview
The Hercules 009 Landfill is listed on the National Priority List for cleanup and is the
subject of a lengthy Remedial Investigation. The primary chemical constituent of concern
is toxaphene, a banned carcinogenic pesticide. The dumpsite includes a neighborhood and
some contamination has spread to the Altama Elementary school property. Several events
occurred related to the 009 landfill during the latter months of 1993 and the first
quarter of 1994. Foremost was the signing of the Consent Decree (CD) that paved the way
for site remediation. This was followed by release of a draft proposal for remediation of
the site and a draft proposal for determination of the extent of off-site contamination.
The Coalition responded to each of these documents. The following is a summary of the
formal comments to these events.
Overview of the Process Leading up to the Signing of the Consent Decree
Superfund cleanup processes can vary considerably depending on the number of
"PRP's" (potentially responsible parties) and the nature of state and local
laws. Hercules, Inc. has always accepted sole responsibility for the 009 landfill.
Further, the state of Georgia has not assumed an active role in the litigation. No local
environmental regulations cover this waste site. Consequently, the process for reaching a
cleanup plan for the site is one of closed-door negotiations between EPA and Hercules,
with copies of correspondence forwarded to the Georgia Environmental Protection Division.
By law the EPA conducted a public commentary period in the fall of 1992 in which a
majority of the directly affected residents requested that the EPA order the removal of
all toxaphene waste from the dumpsite and contaminated neighborhood. EPA's decision
process ignored citizen concerns because the state government held a differing opinion.
With Ga EPD approval, the EPA recommended in situ stabilization for the landfill.
Stabilization is a controversial process with few supporters outside of the EPA.
Scientifically, there is little proof that stabilization is a permanent process. More
likely, the site will still require additional treatment in several decades when the
concrete degrades and the contaminant again begins to migrate. Since there is little
information about stabilization, the EPA ordered preliminary experiments conducted at the
009 landfill. Also, the EPA required Hercules to fully test the area around the site since
the actual borders of the contamination remain unknown.
The Record of Decision (ROD) and Statement of Work (SOW) were forwarded to the Department
of Justice (DOJ) during the Summer of 1993. At the time of filing, the Coalition requested
information on court proceedings in order to respond to the ROD during the public
commentary period. However, the EPA did not inform the Coalition of the passing of the
public commentary deadline until after the Consent Decree was signed. The Consent Decree
is the official DOJ legal instrument ordering the cleanup. Nevertheless, the EPA requested
that the coalition forward comment to the DOJ, although it was probably an exercise in
futility.
In a letter to the DOJ the coalition argued that the Statement of Work is deficient in
several aspects. The Coalition requested the Department of Justice enforce compliance by
judicial fiat in the following matters:
Definite timetable for cleaning up property next to the site. The ROD and SOW
provide for removal of contaminated soils in the neighborhood adjacent to the landfill.
However, the SOW does not set a timetable for completion of this effort. Residents
continue to live with carcinogens in their yards. This portion of the cleanup should be
expedited. Increased monitoring of the landfill. The EPA has failed to define the
boundaries of contamination and has not adequately delineated all potential routes of
toxaphene erosion. The EPA promised the community monitoring of the dumpsite during the
interim phases until full cleanup occurs. However, the SOW mentions only long-term
monitoring and monitoring during remediation.
Remediation of Altama Elementary School grounds. It is unclear from the SOW if the
EPA intends to require remediation of the school grounds. Toxaphene in excess of the
Action Levels is found on school property. Establish genuine performance standards for
determining the success (or failure) of in situ stabilization. Specifically, section
A.3.b., items 3 and 5 (SOW, page 7) governing treatment standards are so vague that they
encompass virtually any remedial activity at the site, regardless of how effective it is
for long-term stability.
Proposed studies of in situ stabilization in site soils
In late December 1993, a subcontractor to Hercules released a draft of proposed
experiments in in situ stabilization at the landfill. In general, the studies described
should be useful in determining conditions for stabilization at the site. The study takes
place in three stages. Initially several concrete formulations are mixed under laboratory
conditions and tested. Formulations that seem promising advance to another level of
laboratory testing in larger volumes and under tougher conditions. Finally, the optimal
formulations are tested for efficacy under field conditions at the site. There are,
however, several points that are confusing or appear to introduce bias into the results.
Some statements made in the workplan raise additional questions on the treatability of
site soils.
The selected remedy may not be applicable to all cells. The review states that Cell
1 contains construction and metal debris including concrete objects, pipe and wire. The
workplan further states, "... significant quantities of debris could hinder
implementation of the planned in situ stabilization/fixation remedy." Clearly this
limitation should have been voiced in the RI/FS, and in the ROD in response to public
questions over the occurrence of buried debris. The geophysical studies now proposed
should have been performed during the RI. Substantial questions of the suitability of the
in situ remedy are raised by these remarks. Previous SITE reports produced by the EPA
indicate that in situ stabilization will not work when debris greater than one-quarter
inch (1/4", 6 mm) are encountered. How individual cells will be remediated if in situ
is contraindicated for some cells should be clarified.
Weathering effects are underestimated. It is unclear if the bench-level tests
include an examination of the weathering effects of temperature gradients likely to be
encountered in the multi-decade lifespan of the site.
Criteria for selection of sludge and soil samples for bench treatability studies should be
better defined. The Plan does not make clear how samples will be selected that are bona
fide examples of materials found in the landfill. The various layers will have differing
properties for immobilization and should be represented proportionally to their occurrence
at the site. Field test sites should reflect site conditions precisely. It is unclear
where the contractor intends to place the in situ test zones at the site. Some of the
field test sites must be adjacent to the ditch. The cycles of water influx and efflux from
the ditch are likely to have a profound influence on the longevity of the cement matrix.
This effect is primarily along the edge nearest the stream. Field studies are essential
for determining these effects on the monolith.
Criteria for matrix alkalinity should be considered. The Glynn Environmental Coalition
favors treatments that decrease the half-life of toxaphene, rather than prolonging its
contact with the environment. Some data exists to indicate that toxaphene is readily
dechlorinated in alkaline media; and toxaphene is less likely to migrate when acidity is
reduced. All other physical factors being equal, the most alkaline material may be best
for reducing the potential for re-exposure at the landfill.
Column leaching tests may bias discovery of colloidal toxaphene emulsions. The contractor
intends to do column leach tests, but the structure of these tests may not discover
movements of toxaphene bound to fine particluate matter, the main form of toxaphene at the
site.
Additional site testing is necessary to determine vertical occurrence of toxaphene.
Questions are raised by Plate number 1-4 of the Plan showing that only two feet of soil
under the sludge actually requires treatment. During the RI the sludge layer was
determined by inference rather than empirically and the calculation for toxaphene
contamination of underburden is an estimation of an estimation. Where actual sampling did
occur, the datum for soil remediation is extended by as much as 300% (see Plate number
1-4, section G-G', SB-30). Plate 1-4 was not made available during the RI/FS; and samples
SB-30 and SB-31 were discounted in the discussion of soil borings. Since these were the
only two actual samples of underlying strata taken during the entire half-decade of the
Remedial Investigation, it is fair to state that half of all samples show deeper
contamination than believed by the EPA. Immediately preceding remediation additional
samples must be taken to determine the full vertical extent of contamination in order to
properly excavate and stabilize the landfill as outlined in the Consent Decree and
Statement of Work. To fail to correct this deficiency almost certainly leaves toxaphene in
contact with the surficial aquifer.
Why are some common physical characterization techniques not utilized? The EPA
estimates that the monolith will need to survive in contact with site soils for several
decades. However, some common techniques used to evaluate concrete structures are not
mentioned in the Plan. Coefficients of Uniformity, for example, are ignored even though
this would be useful for determining the extent of subterranean mixing. Estimates of the
amount of monolith shrinkage and expansion in site soils are not called for in the Plan.
All concrete structures swell and contract due to temperature and moisture. These
observations should reflect directly on the long-term stability of the monolith.
Capillarity of the monolith is an extremely important measurement that is apparently
ignored in the Plan.
The Plan does not appear to address the question of long-term stability. Once the
dumpsite is stabilized and covered protection of human health and the environment is
entirely a function of long-term stability. However, the testing plan seems geared to
short-term effects. Nine extractions in the multiple elution profile simulate an average
summer month in the southern climates. No temperature studies are planned that might
simulate weathering in local soils. Only pulse exposures are performed. It is likely that
the lower areas of the monolith extending into the groundwater will soak for long periods
of time, with possible swelling and weakening of the monolith. Evaluation of the field
plots appears terminated after as little as 28 days, insufficient time to determine if the
matrix is stable.
How will the contractor use the generated data to determine long-term stability?
The plan states that data will be analyzed, but fails to tell how. There is very little
information that would indicate that stabilization is anything other than a short-term
solution, which is inconsistent with claims made in the ROD and SOW. Presumably, there
will be some form of algorithm relating porosity and hardness to stability, but such a
model appears to be unavailable. The meaning of the data as it relates to long-term
effectiveness needs to be explained. Without some form of algorithm for interpreting the
results in the context of on-site stability this project is likely to degenerate into a
foraging expedition to find a justification for the cheapest cement formulation.
Plan to test the Neighborhood
In early 1994 the Coalition received a draft plan for toxaphene testing in areas around
the landfill. The Plan divided testing into four regions surrounding the landfill.
Although generally favorable there were several aspects that did not appear to be properly
addressed.
Western Boundary Sampling Area. This area is known from historical documents as an
access point to the landfill from Georgia Spur 25. Limited sampling in the area during the
RI shows contamination as high as 25 ppm (SB-9R) in the near surface soils from this area.
In regard to sampling in this area Page 3-9 of the Plan states, "a maximum of ten
surface samples will be collected...." Ten samples will not be sufficient to define
this area fully. Additionally, there is a large gap in sampling shown on Figure 3-1. The
sampling should be performed up to the very edge of the Northern Boundary Sampling Area.
Further, the sampling does not extend far enough south to account for all potential areas
of contamination. Thirty samples spaced in a grid pattern from the edge of the Northern
Boundary area is the minimum needed to characterize contamination.
Northern Boundary Sampling Area. The RI ignored this area and it deserves greater
attention than the ten samples now proposed. This is a high human traffic area due to the
car dealership. The area has received surface runoff from the landfill for over a decade.
A grid of at least thirty samples, and preferably forty, should be taken from this area to
ensure worker safety at the car dealership.
Drainage Ditch Sampling Area. The Plan leaves an excessive gap in testing on the
northeast corner. This gap is particularly disturbing since sampling during the RI showed
three positive samples ranging from 0.8 ppm to 2.5 ppm from this area. An additional
twenty-five samples are necessary to delineate the northern contamination boundary.
Residential Area. Sampling in the residential area is more thoroughly detailed than
other areas of the Plan. Unfortunatly, however, the plan allows for
"discretionary" selection of samples at the time of collection. This process
could introduce bias into the collection. Otherwise, the sampling grid network appears to
be a workable system. If sufficient notification is given to allow independent observation
of sampling, similar to the testing of the Altama Elementary School grounds, then claims
of bias can be eliminated.
The field treatability studies and extended sampling of the area were ordered by the
Department of Justice as part of the Consent Decree. Despite public comments made by
Hercules and the EPA there is no "voluntary" cleanup of the affected areas. In
the past both the EPA and the Ga EPD lacked diligence in seeing that environmental
requirements met both the letter and intent of legal instruments meant to protect human
health and the environment. The SOW is vague regarding performance standards for the
remediated dumpsite and the contractor now admits that not all cells may be remediated
using in situ stabilization. It is possible that the EPA and Hercules intend to remediate
just the edges of the dumpsite. Hopefully, with this latest round of activity genuine
progress can be made to prevent any further contamination of the area surrounding the
toxic waste dumpsite.
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