United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
SEPA Superfund
Record of Decision
EPA/ROD/R04-93/156
July 1993
Geiger (C & M Oil)
(Amendment), SC
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50272-101
REPORT DOCUMENTATION 11. REPORTNO.
PAGE EPA/ROD/R04-93/156
4. TItle and SUbtItle
SUPERFUND RECORD OF DECISION
Geiger (C & M Oil) (Amendment), SC
First Remedial Action - Final
7. Authar(s)
2.
3. R8c:~. A~ No.
5.
Report DId8
07/13/93
6.
8.
Performing Organllallon R8pt. No.
9.
Performing Organization Nama and Address
10 Project TulclWork Unit No.
11. Contr8d(C) 01' G..IC(G) No.
(C)
~
12. Sponsoring Organl2atlon Name and Address
U.S. Environmental Protection
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report a Pertod CovIr8d
Agency
800/800
14.
15. Suppl8m8n18ry Not-
PB94-964038
16. Abltracl(UmIt: 3)()-as)
The 5-acre Geiger (C & M Oil) site is located in Rantowles, Charleston County, South
Caro~ina. Land use in the area is predominantly residential and commercial, with
approximately forty people living in the immediate site area. From 1969 to 1974, Adams
Run Services, Inc. used the site for incineration of waste oil. In 1971, eight unlined
lagoons were constructed to hold .the waste oil. 'As a r-esult of complaints from area
residents, the State ordered that all incineration and waste deposition activities
stop, and that the owner take action to prevent spillage, leakage, or seepage of oil
from the site. In 1974, the State ordered the site to close, citing evidence of recent
oil dumping and overflowing. In 1982, the site was purchased by George Geiger;
however, at present, his daughter owns the company- In 1983, the lagoons were filled
with soil, and the site subsequently has been used for storing equipment. A 1987 ROD
addressed source control through onsite thermal treatment to remove organic
contaminants, followed by solidification/stabilization of the thermally treated soil to
reduce mObility of metals; and onsite ground water treatment with offsite discharge.
However, these remedial actions for the soil and ground water were not implemented due
to results of further soil sampling and treatability studies. Site data now indicates
(See Attached Page)
17. Doc:um8n1 AnalysIs L Descriptors
Record of Decision - Geiger (C & M Oil) (Amendment), SC
First Remedial Action - Final
Contaminated Medium: soil
Key Contaminants: VOCs (benzene, toluene), other organics (PCBs), metals (chromium,
lead)
b.
Icl8ntlfiers.IOpen-Ended T-
c.
COSAl1 FIeIdfGroup
18. AvaUabUity Statement
19. Security Class (ThIs Report)
None
20. Security Class (ThIs ~g8)
None
21. No. of Pages
22
22. Price
(SM ANSI-Z39.18)
s../nstllll:tlDM on R..,-
OPTIONAL FORM 272 (4-77)
(Formerly NTJS.35)
Oeputrnent ot CoIMI8ft:I
-------
EPA/ROD/R04-93/156
Geiger (C & M Oil) (Amendment), SC
First Remedial Action - Final
Abstract (Continued)
that the levels of organics are lower than previously described, and that the main soil
contaminants are metals. The 1987 ROD also stated that the ground water contamination
would be treated onsite and that the discharge of the treated ground water would be to an
offsite stream. Since a portion of that stream is onsite, it may be appropriate to
discharge the treated ground water either to an onsite or offsite part of the stream.
This ROD amendment addresses contaminated soil. EPA does not consider the issue of .
discharge location to be a fundamental change to the 1987 ROD. The primary contaminants
of concern affecting the soil are VOCs, including benzene and toluene; other organics,
including PCBs; and metals, including chromium and lead.
The amended remedial action for this site includes treating contaminated soil onsite using
in-situ solidification/stabilization to a depth of 10 feet below land surface; and
monitoring the air. The estimated present worth cost for this amended remedial action is
$3,200,000.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific soil cleanup goals are based on TCLP action levels, and include benzene
5 ug/l; benzo(a)anthracene 10 ug/l; benzo(b and/or k)fluoranthene 10 ug/l; benzo(a)pyrene
10 ug/l; chromium 150 ug/l; 1,2-dichlorobenzene 600 ug/l; 1,1-DCA 5 ug/l; lead 15 ug/l;
Arochlor 1254 1 ug/l; toluene 1,000 ug/lj and trans-1,2-DCE 100 ug/l.
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Amendment to the
Record of Decision
Sn~ry of Remecu.al Alternative Selection
Geiger (C & M Oil) Site
Rantowles, South Carolina
Prepared by:
u.S. Environmental Protection Agency
Region IV
Atlanta, Georgia
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DECLARATION FOR THE
AMENDMENT TO THE
RECORD OF DECISION
SITE NAME AND LOCATION
Geiger (C & M Oil) Site
Rantowles, South Carolina
STATEMENT OF BASIS AND PURPOSE
This decision document presents the sel~cted remedial action
for the Geiger (C & M Oil) Site, in Rantowles, South Carolina,
chosen in accordance with CERCLA, as amended by SARA and, to the
extent practicable, the National Contingency Plan. This decision
is based on the administrative record file for this Site.
The State of South Carolina concurs on the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from
this Site, if not addressed by implementing the response action
selected in this ROD Amendment, may present an imminent and
substantial endangerment to public health, welfare, or the
environment.
DESCRIPTION OF THE REMEDY
This decision addresses the principal threat remaining at
the Site by treating the most highly contaminated soils and
ground-water. The soils will be treated in situ using
solidification/stabilization, such that the Site's soils will not
require any long-term management. The contaminated ground-water
will be extracted, treated on-site, and disposed of either on-
site or off-site. Treated ground-water will be disposed of
either to an on-site stream which flows off-site or to the same
steam off-site. .
The major components of the selected remedy include:
In Situ Stabilization/Solidification of contaminated
soils~ and
Extraction of contaminated ground-water, on-site
treatment of extracted ground-water, and discharge of
treated ground-water to either an on-site or off-site
stream.
DECLARATION
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
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'.
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective. This remedy utilizes
peTlmlnent solutions and alternative treatment technologies to the
m;:tY'hnnm extent practicable for this Site. This remedy does
satis~ the sta~utory preference for treatment as a principal
element of the ~emedy. However, because waste, although treated,
is being left on-site, leachate from the stabilized/solidified
soil must be monitored.
Because this remedy leaves wastes on-site, a review will be
conducted within five years after commencement of the remedial
action to ensure that the remedy continues to provide adequate
protection of human health and the environment. .
~rn~
Patrick M. Tobin
Acting Regional Administrator
~~ /3 /993
Da e '
. .
"".'...
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Amendment to the Record. of Decision
Sl1-~ of Remedial Alternative Selection
Geiger (C , K Oil) NPL Site
Rantowles, South Carolina
1.0
INTRODUCl'ION
This Amendment to the Record of Decision (1987 ROD) provides a
current status of activities that have been completed since the
ROD was signed for the Geiger (C & M Oil) Site on June 1, 1987,
documents the Agency's decision to use Solidification/ .
Stabilization (S/S) alone to treat the contaminated soil instead
of incineration followed by S/S, and incorporates the ROD by
reference (Appendix A). All other provisions of the 1987 ROD
issued by EPA not inconsistent with the ROD Amendments included
herein remain in full force and effect.
1.1
Site Location and nescriDUon
The Geiger Site (the Site) is located along Highway 162 in
Rantowles, Charleston County, South Carolina, approximately ten
(10) miles'west of the city of Charleston (Figure 1). _The Site
is in a sparsely populated rural area. Approximately ten (10)
residences are located near the site to the east and northeast.
The population in the immediate Site area is estimated at forty
(40) people. Several small businesses are located within a half
(O.5) mile of the Site along Highway 162. The property covers a
five (5) acre area of very little topographic relief, however,
the Site area is approximately one and one-half (1.5) acres in
size. This affected area is triangular in shape and is bounded
on two sides by ponds, and on the third side by a small rise,
approximately five (5) feet higher than the Site area.
Elevations on the Site range from approximately fifteen (15) to
thirty (30) feet above mean sea level..
1.2
Sit.. History
On June 1, 1987, EPA selected a remedial alternative for the
Geiger (C & M Oil) Site cleanup which included:
- recovery of contaminated ground-water with on-site treatment
and discharge to an off-site stream~
- on-site thermal treatment of excavated soils to remove organic
contaminants ~
- Solidification/Stabilization (S/S) of thermally-treated soil to
reduce mobility of metals~
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- During Remedial Design SIS would be reviewed to determine if
SIS alone would achieve the remedial action goals; and
- During Remedial Design, soil cleanup goals would be refined.
A Potentially Responsible Party search conducted prior to the
commencement of the Remedial InvestigationlFeasibility Study
(RI/FS) determined that there were no viable Potentially
Responsible Parties. EPA, therefore, conducted the RIIFS and
since the signing of the ROD on June 1, 1987, EPA has conducted
additional field investigations in order to better characterize
and define the extent of the soil contamination. The results of
the analysis of the additional soil samples showed relatively low
levels of organic contaminants of concern (COCs) and that lead
and chromium were the primary COCs. During the development of
the Remedial Design for th~ soil, treatability testing and
modeling were conducted to determine if SIS alone would achieve
the remedial action goals and to refine the soil cleanup goals
(Table 1). Treatability studies, including the one performed by
EBASCO, conducted on soils from the Site indicated that sls alone
would meet the cleanup goals for the Geiger Site. The EBASCO
Study can be found in the Administrative Record (See Section 3.0
"Community Relations"). The determined soil cleanup levels fall
within EPA's acceptable risk range, are protective of human
health and.~he environment, and will meet state water quality
standards at the point of discharge. Based on the results of
the additional soil samples, treatability studies, and because
the revised remedy fundamentally changes the original remedy, the
Agency has decided to amend the 1987 ROD pursuant to the National
Contingency Plan (NCP), 40 C.F.R. S 300.435(c)(2)(ii).
1.3
BxDlanation of Fundamental Remec:lv Chanae
The 1987 ROD specified on-site thermal treatment of excavated
soils to remove organic contaminants and SIS of the thermally
treated soil to reduce mobility of the metals. The 1987 ROD also
stated that during the Remedial Design, SIS would be reviewed to
determine if SIS alone would achieve the remedial action goals.
The 1987 ROD stated that the action levels in the ROD were
preliminary goals and subject to refinement during the Remedial
Design.
New information has been developed since the issuance of the 1987
ROD. Additional soil sampling has indicated that the levels of
organic COCs were lower than previously described in the RI/FS
reports and the area of significant contamination is smaller than
originally thought. Extensive sampling has more precisely
defined the location of the contamination and shown that the main
soil contaminants are metals, which can be treated effectively
using S/S alone. Therefore, based on the results of the site-
specific treatability studies, the contaminants that are
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LOCATION PLAN
flfioen
(ca MOID
SITf •
mil
OEIOE
(CQM
SITE
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Table 1
TRBATHBHT CRITBIUA
CRRVTCAL
INDICATOR CHEMICAL
LEACHATE CRITERIA1(ua/11
10
Benzo[a]pyrene
Benzo [a] anthracene
10
10
Benzo[b and/or k]fluoranthene
PCB (Arochlor 1254)
1
Benzene
52
trans-1,2-Dichloroethylene
Chromium
1002
Lead
150
15
-
1,2-Dichlorobenzene
1,1-Dichloroethane
10002
6002
Toluene
53
Notes:
1 Criteria is Action Level.
2 Leachate criteria equal National Pr~ Drinking Water
Regulations latest and proposed ~~~imum Contaminant Levels.
3 Criteria is MCL for 1,2-Dichloroethane
Leachate Extraction Method:
TCLP
PHYSICAL
Prooertv
Pass/Fail Criteria
Unconfined Compressive Strength
Flexible Wall Pe~eability
~ 50 psi
1 x 10-5 em/see
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currently found in the soil at the site can be treated
effectively by the process of SIS alone. In addition, based on
current rates, incineration would be three to four times more
costly than SIS alone. In snmmary, the contaminants currently at
levels of concern at the Geiger (C , M Oil) Site can be treated
effectively solely using S/S.
1..
BxDlanation of Sicm.ificant Difference.
The 1987 ROD also stated that ground-water contamination would be
treated on-site and that the discharge of the treated ground-
water would be to an off-site stream. Since the signing of the
1987 ROD, it has been determined that because a portion of the
stream is on-site, discharge of the treated ground-water may be
appropriate to either an on-site or off-site part of the stream.
The on-site discharge would be to the same stream as off-site
discharge and would meet. the same substantive standards (ARARs)
as would off-site discharge. If discharge is to the off-site
part of the stream, an NPDES permit would be required, but if
discharge is to the part of the stream that is on-site, then the
substantive requirements of the NPDES permit would be met, but
the permit itself would not have to be obtained. Therefore, EPA
does not consider the issue of discharge location to be a
fundamenta~ change to the 1987 ROD.
2.0
BNPORCBMBNT ANALYSIS
A Potentially Responsible Party search was conducted in 1984
prior to the -commencement of the RI/FS. It was determined that
there were no viable Potentially Responsible Parties.
3.0
COIIMUNIft RELATIONS
EPA prepared a Record of Decision (ROD) on June 1, 1987, taking
into consideration the comments from the public and the results
of the FS. The most environmentally sound and cost-effective
remedy was then selected as a part of the ROD phase of the
Superfund process. EPA selected thermal treatment of the soil to
remedy the organic contamination, SIS of the soil following
thermal treatment to remedy the inorganic contamination, recovery
of contaminated ground-water with on-site treatment, and
discharge to an off-site stream. EPA also stated that during the
Remedial Design SIS would be reviewed to determine if S/S alone
would achieve the remedial action goals. A public meeting was
held in January 1987 in which all the alternatives were
presented, although a preferred remedy was not chosen. An
information repository was established and is located at the
Hollywood Town Hall in Hollywood, South Carolina, near Rantowles.
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This ROD Amendment was available for review and comment during
the public comment period, May 25, 1993, until June 25, 1993, and
will become part of the Administrative Record File, as required
by CERCLA S 117, 42 U.S.C. S 9617, and the NCP, 40 C.F.R.
S 300.825(a)(2). No comments were received during the public
comment period and no requests were received for an extension of
the c~mment period or for a public meeting.
..0
..1
CURRBN'l' Srl'B STATUS
BYdroaeo10C1V
Ground-vater Contaminants
The current areal and vertical extent of ground-water
contamination were delineated from several sources of
information. The original source of information was £rom tbe
Remedial Investigation (RI). Since that time, additional
monitoring wells were installed in 1988. There are currently
twenty-seven (27) permanent monitoring wells on-site and off-
site, located in clusters of two to three wells, which range in
depth from approximately ten (10) to forty-five (45) feet below
land surface. After the new monitoring wells were installed,
these new wells and the wells installed during the RI were .
sampled. There also have been several additional sampling events
since 1988; the last sampling event occurred during May 1992
through June 1992. During the 1992 sampling event, the permanent
monitoring wells were sampled along with eleven (11) additional
temporary monitoring wells that were installed further. .
downgradient than the permanent wells, and at various locations
on-site and upgradient.
Sampling and analysis of the Monitoring wells indicate the
following:
Cadmium was detected above Maximum Contaminant Levels (MCLs) in
well MW-6s in the earlier sampling events. It was not detected
in the 1992 sampling event in any of the wells. Two metals which
were consistently detected above MCLs in all the sampling events
were the following:
Contaminant
Well
No.
Maximum Level
Detected
chromium
lead
MW-2s
MW-6s
7.8 mg/L
3.4 mg/L
MCLs
Federal/State)
0.100 mg/L
0.015 mg/L
No contaminants of concern were detected during the last sampling
event in 1992 in samples collected fram the additional permanent
monitoring wells located downgradient and north to northwest of
the Site.
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During the RI, organic contaminants, some of which exceeded MCLs,
were detected primarily in one monitoring well (MW-4s). However,
since the signing of the 1987 ROD, the results from five
additional post-ROD sampling events have not shown any organics
in this well. Only a few organics have been detected since that
time, sporadically in the wells installed during the RI, but no
organics were detected in the newer wells added in 1988. The
types of organics and the levels detected -- mostly low and below
MCLs -- varied with each sampling event and varied in each well.
Based on the sampling data, ground-water contamination has been
found primarily in the water-table wells located in the surficial
aquifer. The boundary of the contamination plume is defined by
those wells in which no contaminants were detected or were not
above background. The zone is bounded on the northwest side by
wells MW-08 to MW-11, on the west side by well MW-12, on.the
southwest side by well MW-03, and on the south side by temporary
well GT3BG2. -
4.2
On-Si~. Soil.
Since the 1987 ROD was signed, BPA has conducted additional field
investigations in order to better characterize and define the
extent of the soil contamination. The last sampling event
occurred in May 1992. The inorganics chromium and lead were
detected in most of the samples from the Site area.
Significantly high levels of the inorganics were detected,
especially at and near the-location of the old lagoons. The
mAximum chromium level detected was 6,275 mg/kg and the maximum
lead level detected 'was 730 mg/kg. A few organics, primarily
toluene and PCB, were detected in some of the samples collected
from the Site area near the old lagoon. The maximum levels,
respectively, of toluene and PCB detected in the soil samples
were 144 mg/kg and 10 mg/kg. Most soil sample levels of toluene
and PCB, however, were below 10 mg/kg and 1 mg/kg, respectively.
The results of the various field investigations show the area
needing treatment for soil contamination to be the triangular
area described in Section 1.1 of this Amendment. This triangular
area will be treated to a depth of ten (10) feet. Analytical
. results fram the RI are in the Remedial Investiaation Re~ort.
The analYtical results from the additional field investigations
are in the In-Situ Solidification/Stabilization of Contaminated
Soil Remedial Desian ReDort.
5.0
SUlllaRY OF SID RISKS
Public Beal~ and Bnviromaen~al ObiecUve.
5.1
At the time the 1987 ROD was signed, there was no current public
health threat to off-site residents and no significant risk to
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on-site workers under the reasonable case scenario via dermal
contact. Health risks associated with exposure by inhalation
were considered negligible. Nearby wells, which were located
upgradient, had not been affected by Site contaminants. There
are no nearby private wells located downgradient. Under the
future use scenario where the Site is developed and private wells
are installed, it was determined that soil remediation would be
necessary to prevent further leaching of contaminants into the
ground-water as well as recovery of the contaminated ground-water
in order to meet the remedial action objectives.
The waters of the surficial aquifer have been classified as Class
GB ground-water. Class GB aquifers are considered potential
sources of drinking water and must be remediated to levels that
do not adversely affect human health and the environment.
Sampling data indicates that several contaminants in the ground-
water plume exceed drinking water standards (chromium and le~d).
At the present time, all 'residents have access to municipal
water. In addition to being classified as a Class GB aquifer,
discharge of the untreated ground-water into the on-site ponds,
which flow into an unnamed creek and thence into the Wallace
River, may potentially have an environmental impact on plant and
aQ;m~l species in the various surface water bodies.
6.0
ALHRHA!'IVBS CONSZDBRBD FOR SOIL RBMBDZM'ZON m
JtJNB 198' ROD
Soil remediation alternatives considered for the Geiger (C & M
Oil) Site are listed in Table 2 along with the reasons certain
alternatives were eliminated. For an in-depth analysis of the
other soil alternatives considered, see pages 23 - 32 of the 1987
ROD.
6.1
Al1:ernative PreviouslY Selected For Soil
The selected remedy for soil, as specified in the 1987 ROD, was
excavation, on-site thermal destruction, and Stabilization I
Solidification (S/S). The selection of this alternative is now
being reevaluated because new information has been developed
about the nature and extent of the contamination at the Site and
changes in the relative costs of various remedies since the 1987
ROD.
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Table 2
TBCBBOLOGIBS CONSIDERED PaR SCRBBHING
GBIGBR (C & !I OIL) SITE
RAHTOWLBS, SOUTH CAROLIRA
Possible Technologies
Eliminated (E)
or
Retained (R)
If Eliminated
Reason for
Doing So
I. Soil Technoloqies
1. Extraction (Soil FJ.ushing) E Not appl.icable to
waste characteristics
2. Solidification/Stabilization R
3. Attenuation E Not applicable to
Site characteristics
4. Immobilization E Unknown reliability
and effectiveness
5. Incineration R
6. Capping R
7. Vegetative Cover R
8. Excavation and Off-Site R
Disposal
9. Partial Excavation with R
On-Site Disposal
10. On-Site Containment/ R
Encapsulation
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Table 2 (cont'd.)
Possible Technologies
Eliminated (E)
or
Retained (R)
If Eliminated
Reason for
Doing So
II. Groundwater Technoloaies
A. Groundwater Containment
1. Slurry Wall R
2. Grout Curtains E More expensive and
less effective than
slurry walls
B. Groundwater Recovery
1. Pumping (Extraction Wells) R
2. Subsurface Drains E Hydraulic conductivity
may be high
C. Groundwater Treatment
1. Flocculation/Sed~entation R
2. Filtration R
3. Air Stripping R
4. Spray Irrigation R
5. Activated Carbon R
Adsorption
6. Ion Exchange/Sorptive R
Resins
7. Reverse Osmosis E Expensive, dilute
waste stream
8. Biological Treatment R
D. Groundwater Disposal
1. Discharge to Surface Water R
2. Reinjection E Complex and expensive
compared to surface
discharge
3. Pump to Local Wastewater R
Treatment Plant
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6.2
-7-
neacriDtion of Alternative currently BeinG Conaidered
for Soil Remediation
Alternative 1
In-situ Stabilization/Solidification
Alternative 2
Excavation, on-site thermal destruction,
Stabilization/Solidification
6.2.1
Alternative 1 - In-Situ Stabili.aUon/Solidification
Alternative 1 consists of the treatment of affected soil in place
by in-situ stabilization. This alternative involves the
stabilization of soil to a depth of ten feet below land surface.
During the performance of the Remedial Design, it was determined
that in-situ stabilization would be more effective at the Site
than ex-situ stabilization since the ground-water was. very
shallow, and because of dust and air emissions from excavation of
the contaminated soil.
In-situ stabilization includes the use of deep soil mixing
equipment that delivers stabilization reagents to the ~ffected
soils during mixing operations. The process involves auguring
into the affected soils to the desired depth using hollow~stem
augers. The hollow-stem augers overlap and can vary from two to
five augers per assembly. A shallow soil mixing system also is
available and uses a single, wide diameter auger rather than an
assembly of overlapping augers. Treatment agents are introduced
into the disturbed matrix through jets constructed in the auger.
The reagents can be introduced in either a liquid or slurry form.
A system such as this could consist of the following typical unit
operations:
.
Shallow Soil Mixing Assembly
Reagent Containers and Feed Systems
.
Treatment duration will vary by depth and by the amount of mixing
required to ensure adequate S/S. The treatment duration
estimated for this Site is less than a year. Testing of the
solidified treatment zones also will be necessary to ensure that
performance requirements are being met. Low levels of organics
possibly may volatilize during the treatment process, therefore,
air monitoring equipment will be used. Treatability studies have
been completed using Site soils and these studies showed that
this alternative will effectively meet the remediation goals for
both the metals and the organics.
For a detailed description of ARARs, see Sections 6.3(2) and 8.2
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of this Amendment. The S/S alone treatment option is currently
estimated at $3.2 million (1992).
6.2.2
Al~ernative 2 - Bxcavation. On-Si~e ~hermal Destruction.
Stabiliaation/Solidification
This alternative would consist of excavation of all contaminated
soils on the Site (probably requiring a dewatering step), thermal
destruction of the organic contaminants in the soil in an on-site
mobile thermal destruction unit, treatment of the inorganic
contaminants in the soil with S/S reagents, and then backfilling
the excavated areas with the treated soil.
At the time the 1987 ROD was signed, the estimated cost.of the
soil remedy selected in the ROD was approximately $5.2 million.
At this time, using the current estimated volume, the remedy
selected in the 1987 ROD could cost approximately $1040 to $12.0
million. The estimated time period for this alternative is
greater than a year.
This alternative would destroy the organic contaminants and
stabilize the metals so that they would not migrate. For an in-
depth analysis of this alternative, including ARARs, see pages
30 - 31 of.~he 1987 ROD.
6.3
COJDDarative Anal vaia
This analysis will compare the alternatives, A-I and A-2, for the
nine evaluation criteria detailed in the National Contingency
Plan (NCP). For a more detailed analysis of the remedy selected
in the 1987 ROD, which has S/S as a component, see pages 30, 31,
and 33 - 36 of the 1987 ROD.
1. Overall protection of human health and the environment -
Both of the alternatives accomplish this criterion. Both of the
alternatives are within Agency guidelines and would provide
overall protection by reducing or controlling the threat by
remediating the contaminated soil. Both alternatives would meet
the remediation goals and be long-ter.m protective of human health
and the environment: A-I by chemically and physically binding
the organic and inorganic contaminants using S/S alone, and A-2
using thermal treatment to destroy the organic contaminants and
S/S to bind the inorganic contaminants. The additional
protection offered by in-situ S/S is further enhanced by the
short-term protectiveness gained from treatment without
excavation of waste materials, which would not have the air
emission concerns associated with thermal treatment of soils.
2. ComDliance with ARARs - Alternatives A-I and A-2 would meet
ARARs for soil and ground-water. No waiver from ARARs would be
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necessary to implement either cleanup alternative.
ARARs for A-1 Soil Treatment
Currently, 40 C.F.R. Parts 60 and 61, 42 U.S.C. S 7401 et. seg,
which include the National Emissions Standards for Hazardous Air
Pollutants (NESHAPs), promulgated pursuant to the Clean Air Act
S 101 et. seq, as amended, and the South Carolina Air Pollution
Control Regulations and Standards, SC Reg. 61-62, promulgated
pursuant to the Pollution Control Act, SC Code of Laws, 1976, as
amended, do not apply to air emissions caused by mixing the soil
in-situ with stabilization reagents. SC Reg. 61-62 establishes
limits for emissions of hazardous air pollutants and particulate
matter, and establishes acceptable ambient air quality standards
within South Carolina. Because the selected treatment does not
include thermal treatment ,of the soil as proposed by the 1987
ROD, no ABARs apply to air emissions caused by stabilizing the
soil. .
40 C.F.R. Part 261, Subpart C, Characteristics of Hazardous
Waste, promulgated pursuant to the Resource Conservation and
Recovery Act (RCRA) S 3001, 42 U.S.C. S 6921, and SC Reg. 61-
79.261, Subpart C, defines those solid wastes which are subject
to regulations as hazardous waste. Because the wastes were not
hazardous Wastes, currently no RCRA regulations apply, including
Land Disposal Regulations. However, confirmation sampling will
be done to ensure that the Toxicity Characteristic Leaching
Procedure (TCLP) requirements are not exceeded and thus no RCRA
regulated hazardous wastes .have been generated.
ARARs for Ground-Water
If the alternative to discharge treated ground-water on-site is
chosen, the substantive requirements of the NPDES program will be
met although no permit is required for on-site discharge of
treated ground-water. If the off-site alternative to discharge
ground-water is chosen, the substantive and administrative
requirements of the NPDES program will be met and a permit will
be obtained.
For an in-depth analysis of the application of ARARs to the
original remedy which included SIS, see pages 3S - 36 of the 1987
ROD.
3. Lona-term effectiveness and Derformance - Both of the
alternatives would provide a permanent remedy for both organic
and inorganic contaminants. Therefore, either alternative would
meet this criterion and reduce the risk associated with soil
contamination at this Site.
4. Reduction of toxicitv. mobi1itv. and volume - Both
alternatives would reduce the toxicity and mobility of soil
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contamination. Alternative A-1 would accomplish this by binding,
both chemically and physically, the organic and inorganic
contaminants. Alternative A-2 would destroy the organic
contaminants and chemically and physic~lly bind the inorganic
contaminants. Both alternatives would prevent the threat of
further degradation of the ground-water.
S. Short-term effectiveness - Alternative A-l would provide
short-term effectiveness. Emissions would be minimal since the
remedy is in-situ and does not require excavation of the waste
materials. Alternative A-2, however, would not be short-term
effective because there would be air emissions from the thermal
treatment unit and dust and volatilization of contaminants as a
result of excavation of the soil. In addition, A-1 would be
completed in less time than A-2 since A-2 would require
additional time to excavate (including dewatering steps), return
the soil following treatment, and thermally treat it.
6. Implementabilitv - Both alternatives are technically
feasible. The reliability of in-situ stabilization equipment has
been demonstrated at several sites. Implementation of the
treatment process for Alternative A-1 has same level of technical
problems that could lead to schedule delays, especially since the
treatment reagents must be equally distributed throughout each
treatment ~ea. The primary uncertainty associated with in-situ
stabilization is the variability of treatment throughout the
treatment zone. This concern will be addressed by requiring
sufficient overlap between treatment areas and by sampling of the
treated zone. This alternative will not require permitting or
coordinating with other offices or agencies. Special drilling
equipment capable of injecting treatment agents during drilling
is required for in-situ stabilization, however, several
commercial vendors offer the process. Alternative A-2 is a
proven technology. Wastes would be fed into the thermal unit at
a rate providing sufficient retention time for complete
combustion of the organic contaminants. Air monitoring and
analysis equipment would be needed to monitor scrubber effluent,
solids residue, combustion gases, system pressure and
temperature, and air flow rates.
7. ~ - Both of the alternatives are protective of
health and the environment. The costs associated with
Alternative A-l are less than the costs associated with
Alternative A-2 and for this reason, Alternative A-1 is
cost effective remedy.
8. State Acceptance - The State of South Carolina concurs with
the SIS alone treatment alternative. .
human
the most
9. Community Acceptance - At the time the 1987 ROD was signed,
many members of the community were quite vocal in criticizing the
thermal treatment portion of the remedy. This information was
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obtained from past articles in the newspaper and from
conversations with local residents in the last year or two. They
cited a history of exposure to contaminants from the incinerator
that was previously located at the Site. There were no official
comments submitted during the public comment period opposing the
alternative selected in the 1987 ROD, however, during the public
comment period EPA had not indicated a preference for a
particular remedy in the proposed plan. Conversations with
nearby residents in the recent past about Alternative A-1
indicated that the residents were not opposed to SIS only of the
contaminated soil.
7.0
SBLBC'RD RBIIBDY
Based upon consideration of the requirements of CERCLA, ~he
detailed analysis of both 'alternatives, and public comments, EPA
has determined that Alternative A-1 is the most appropriate -
remedy for the contaminated soil at the Geiger (C & M Oil) Site
in Rantowles, South Carolina. -
The selected remedy consists of the treatment of affected soil in
place by in-situ stabilization. The area to be treated is the
triangular area described in Section 1. 1 of this Amendment. - This
area is bounded on two sides by ponds and on the third side by a
small rise, approximately 5 feet higher than the Site ~rea.
Testing of the solidified treatment zones also will be necessary
to ensure that performance requirements are being met.
Treatability studies have been completed using Site soils that
showed this alternative effectively will meet the remediation
goals for both the metals and the organics.
The selected remedy consists of the treatment of affected soil in
place by in-situ stabilization. This alternative includes the
use of deep soil mixing equipment that delivers stabilization
reagents to the affected soils during mixing operations. The
process involves auguring into the affected soils to the desired
depth using hollow-stem augers. The hollow-stem augers overlap
and can vary from two to five augers per assembly. A shallow
soil mixing system also is available and uses a single, wide
diameter auger rather than an assembly of overlapping augers.
Treatment reagents are introduced into the disturbed matrix
through jets constructed in the auger. The reagents can be
introduced in either a liquid or slurry form.
8.0
~Y RBOUIRBMBNTS
The u.s. EPA and SCDBEC believe that this remedy will satisfy the
statutory requirements of CERCLA S 121, 42 U.S.C. S 9621, and NCP
S 300.430, 40 C.F.R. S 300.430, of providing protection of human
health and the-environment, attaining Applicable or Relevant and
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Appropriate Requirements (ARARs) of other environmental statutes,
will be cost-effective, and will utilize permanent solutions and
alternative treatment technologies or resource recovery
technologies to the maximum extent practicable. Sections 8.1
through 8.5 below analyze the statutory requirements for this
Site.
8.1
Pro~ec~ion of Buman Health and the Bnvironment
The selected remedy provides protection of the public health and
environment through Solidification/Stabilization treatment of
contaminated soil. For a detailed analysis of this requirement,
see Section 6.3(1) of this Amendment.
8.2
A~taiDmen~ of the Apolicahle or ReleVU1~ and ADDrooria~e
Reau1rements ,AltARs) ~. .
Remedial actions performed under CERCLA must comply with all
ARARs. All alternatives considered for the Geiger Site were
evaluated on the basis of the degree to which they complied with
these requirements. The selected remedy will comply with all
ARARs. Although the selected treatment does not include thermal
treatment Of the soil as proposed by the 1987 ROD, the selected
remedy does envision possible volatization of the-low
concentration organics when the soil is mixed with the
stabilization reagents. Thus, confirmation sampling will be done
to ensure that the air quality remains good and that no ARARs
become applicable to the air aspect of the remedy. In addition,
because the wastes were not hazardous wastes, no Resource
Conservation and Recovery Act (RCRA) regulations apply. However,
confirmation sampling will be done to ensure that the TCLP
requirements are not exceeded and thus no RCRA regulated
hazardous wastes have been generated.
Treated ground-water may be discharged on-site or off-site. If
the on-site alternative is chosen, no NPDES permit is required,
but the substantive requirements of the NPDES permit will
continue to be in effect and these requirements will be met. The
reason for the ground-water discharge location contingency is
because BPA will not need access to discharge treated ground-
water on-site. In addition, there is no difference in
discharging the treated ground-water on-site as opposed to off-
site because it is the same stream.
8.3
Co.~ Bffectiven..s
The remedy selected in the 1987 ROD now could cost $10.0 to $12
million. The Stabilization/Solidification alone treatment option
is currently estimated at $3.2 million (1992), and therefore, is
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the more cost effective remedy compared to the original remedy.
8.4
Utili.ation of Permanent Solutions and Alternative
Treatment '1'ecbnolOGY or Resource Recovery Technolocriea
to the Maximwa Brtent Practicable
u.s. EPA believes the selected remedy is the most appropriate
cleanup solution for the contaminated soils at the Geiger Site
and provides the best balance among the evaluation criteria for
the remedial alternatives evaluated. This remedy provides
effective protection in both the short and long-term to potential
human and environmental receptors, is readily implementable, and
is cost effective.
Stabilization/Solidification of the contaminated soil represents
a permanent solution (through treatment) which will effectively
reduce and/or eliminate mobility of hazardous wastes -and
hazardous substances into the environment.
8.5
Preference for Treatment as a princiDal Element
Treatment of the contaminants will effectively prevent them from
posing a threat by leaching to ground-water, and therefore,
satisfies the preference for treatment.
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APPENDIX A
RECORD OF DECISION, JUNE 1987
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