PB94-964062
EPA/ROD/R04-94/191
October 1994
EPA Superfund
Record of Decision:
Marzone Inc./Chevron Chemical Co.
Superfund Site (O.U. 1), Tifton, GA,
9/30/94
-------
~\"{E.O ST..~
.~\S'
;: --. \
~~~
,~,~
~"x
~,~,'\.
~'"....
...
-,.....
RECORD OF DECISION
SUMMARY OF REMEDIAL AL TERNATIVE SELECTION
MARZONE INC. / CHEVRON CHEMICAL COMPANY SUPERFUND SITE
OPERABLE UN" #1
TIFT COUNTY, GEORGIA
PREPARED BY
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
~
-------
DECLARATION
of the
RECORD OF DECISION
SITE NAME AND LOCATION
Marzone, Inc./Chevron Chemical Company Site, Tilton, Tift County, Georgia
STATEMENT OF BASIS AND PURPOSE
This decision document (Record of Decision) presents the selected remedial action for
the Marzone, Inc./ Chevron Chemical Company Site in Tift County, Georgia;
developed in accordance with the CompreheI\Sive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), as amended by the Superfund
Amendments and Reauthorization Act of 1986 (SARA), and to the extent practicable,
the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). This
decision is based on the Administrative Record for this Site.
The state of Georgia, as represented by the Georgia Environmental Protection
Division (GaEPD), has been the support agency during the Remedial Investigation
and Feasibility Study process for the Marzone, Inc. / Chevron Chemical Company
Site. In accordance with 40 Part CFR 300.430, as the support agency, GAEPD has
provided input during this process. GaEPD has concurred with the remedy selected
in .the ROD, but defers concurrence with the performance standards in light of the
newly promulgates rules of the Georgia Site Hazardous Response Act.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from the Site, if not addressed
by implementing the response action selected in this Record of Decision (ROD), may
present an imminent and substantial endangerment to public health, welfare, and/ or
the environment.
DESCRIPTION OF SELECTED REMEDY
EP A has organized the work at this Site into two phases or operable units (OUs).
Operable Unit #1 involves contamination on the 1.68-acre former Marzone pesticide
blending area, part of the Slack Property, and railroad drainage ditch past the
southwest comer of the horse pasture, and contaminated groundwater related to the
Site. This first operable unit is broken down into two separate remedies; one for
groundwater and the other for soil.
For contaminated groundwater the selected remedy is Groundwater Pump and Treat
and enhancement through use of an infiltration gallery. The major components of the
-------
selected remedy include:
. The implementation of institutional controls.
. The implementation of a pumping test, to aid in determining specific
design criteria for the extraction system.
The design and construction of groundwater extraction wells.
The installation of a security fence around the on-site treatment unit.
The design and installation of a groundwater pumping system, a
groundwater filtration system, an on-site treatment system, and an
infiltration gallery.
The start-up and operation of this system.
The transportation, regeneration, recycling, and disposal of the spent
filters. I
The operation and maintenance of a long-term groundwater monitoring
program. Includes quarterly monitoring of parameters in extraction
wells and specified monitoring wells.
The cost of this alternative would be $3.4 million.
For the soil contamination the selected remedy is Low Temperature Thermal
Desorption. The major components of the selected remedy include:
. The excavation of all soil contamination above the performance
standards.
The staging and preconditioning of soil for entry into the thermal
desorption unit.
The feeding of soil into the heated chambe~ for treatment.
The processing through the thermal desorption unit including the bag
house, GAC, or other equivalent system.
The placement of treated, decontaminated soil back to the Site.
The periodic soil sampling during treatment to verify effectiveness of
the remedy.
. Air monitoring to ensure safety of nearby residents and workers.
The cost of this remedy would be $4.8 million.
.
.
.
.
.
.
.
.
.
.
.
The total cost of the groundwater and soil remedy for OUI of the Marzone Site is
approximately $8.2 million.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the environment, complies
with federal and state requirements that are legally applicable or relevant and
appropriate to the remedial action, and is cost effective. This remedy satisfies the
preference for treatment that reduces toxicity, mobility, or volume as the principal
element. Finally, it is determined that this remedy utilizes a permanent solution and
alternative treatment technologies to the maximum extent practicable.
~ rYf7J~ 'IE ~lA. 3CJ.;tJ}4
JOHN H. HANKINSON, JR REGIONAL ADMINISTRATO ' DATE
-------
TABLE OF CONTENTS
1.0 SITE NAME, LOCATION, AND DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . .
2.0 SITE HISTORY AND ENFORCEMENT ACI1VITIES . . . . . . . . . . . . . . . . . . . .
1
2
3.0 IDGHLIGHTS OF COMMUNITY PARTICIPATION. . . .. . . .. . . . . . . . . . ..
5
4.0 SCOPE AND ROLE OF OPERABLE UNITS . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
5.0 SUMMARY OF SITE CHARACI'ERISTICS ........................... 7
5.1 General Site Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1.1 Geology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1.2 Hydrology. . . . . . . . . '.' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2 Results of Site Remedial Investigation. . . . . . . ~ . . . . . . . . . . . . . . . . . . 9
5.2.1 Soil Migration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .".. 16
5.2.2 Groundwater Migration. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16
6.0 SUMMARY OF SITE RISKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
6.1 Chemicals of Concern. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
6.2 Human Health Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
6.3 Summary of Exposure Assumptions. . . '0' . . . . . . . . . . . . . . . . . . . . .. 18
6.4 Summary of Toxicity Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
6.5 Risk Characterization/Management. . . . . . . . . . . . . . . . . . . . . . . . . . .. 20
6.6 Environmental Risks. . . . . . . . . . . . . . . . . . .i. . . . . . . . . . . . . . . . . . .. 21
6.7 Cleanup Levels. . . . . . . . . . . . . . . . . . . . . . .~ . . . . . . . . . . . . . . . . . . .. 21
7.0 DESCRIPTION OF ALTERNATIVES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24
GROUNDWATER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24
7.1 ALTERNATIVE NO.1 - No Action for Groundwater. . . . . . . . . . . . .. 24
7.2 ALTERNATIVE NO.2 - Institutional Controls and Monitoring for
Groundwater. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25
7.3 ALTERNATIVE NO.3 - Groundwater Pump and Treat. . . . . . . . . . .. 25
SOIL [[[ 26
7.4 ALTERNATIVE NO.4 - No Action for Soil. . . . . . . . . . . . . . . . . . . . .. 26
7.5 ALTERNATIVE NO.5 - Institutional Controls and Monitoring for
Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26
7.6 ALTERNATIVE NO.6 - Excavation and Landfill Disposal. . . . . . . . .. 27
7.7 ALTERNATIVE NO.7 - Bioremediation by Land
Farming/Composting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27
7.8 AL TERNA TIVE NO.8 - Low Temperature Thermal Desorption. . . . .. 28
-------
8.0 SID.-1MARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES. . . .. 30
GROUNDWATER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 31
8.1 Overall Protection of Human Health and the Environment. . . . . . . . .. 31
8.2 Compliance with ARARs ................................... 31
8.3 Long-Term Effectiveness and Permanence. . . . . . . . . . . . . . . . . . . . . .. 32
8.4 Reduction in Toxicity, Mobility, and Volume Through Treatment. . . .. 32
8.5 Short-Term Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 32
8.6 Implementability ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 32
8.7 Cost Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 32
8.8 State Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
8.9 Community Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
SOIL ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
8.10 Overall Protection of Human Health and the Environment. . . . . . . .. 33
8.11 Compliance with ARARs .................................. 33
8.12 Long-Term Effectiveness and Permanence. . . . . . . . . . . . . . . . . . . .. 34
8.13 Reduction in Toxicity, Mobility, and Volume Through Treatment. . " 34
8.14 Short-Term Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 34
8.15 Implementability ......................................... 34
8.16 Cost Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 34
8.17 State Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35
8.18 Community Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35
9.0 SID.-1MARY OF SELECTED REMEDY. . . . . . . . . . .! . . . . . . . . . . . . . . . . . . .. 37
9.1 Groundwater Remedy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 37
9.1.1 Performance Standards for GroW1dwater ................. 38
9.1.2 Infiltration Standards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
9.1.3 Design Criteria for Groundwater. . . . . . . . . . . . . . . . . . . . . .. 39
9.1.4 Compliance Monitoring for GroW1dwater . . . . . . . . . . . . . . . .. 39
9.1.5 Cost. . . . . . . . . . . ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39
9.2 Soil Remedy. . . . . . . . . . . . . . . . . . . . . . . . . . . ~ . . . . . . . . . . . . . . . .. 39
9.2.1 Performance Standards for Soil . . . . . . . . . . . . . . . . . . . . . . . .. 40
9.2.2 Design Criteria for Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42
9.2.3 Soil Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42
9.2.4 Cost. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42
10.0 STATUTORY DETERMINATIONS. . . . . . . . . . . . . . . . .. . . . . . . . . . .. . . .. 43
10.1 Protection Of Human Health And The Environment. . . . . . . . . . . . .. 43
10.2 Compliance With ARARs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 43
10.3 Cost Effectiveness.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 47
10.4 Utilization Of Permanent Solutions To The Maximum Extent
Practicable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 47
10.5 Preference For Treatment As A Principal Element. . . . . . . . . . . . . . ., 47
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES. . . ... . . . . . . . . . .. ., 48
-------
1- -
APPENDIX A [[[ 49
RESPONSIVENESS SUMMARY..... .... .... . .... . ... .... . ...... 49
-------
LIST OF TABLES
TABLE 1: AMBIENT ATMOSPHERIC CONCENTRATION OF
CONTAMINANTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14
TABLE 2: CONCENTRATIONS OF CONTAMINANTS IN SURFACE SOIL .... 14
TABLE 3: CONCENTRATIONS OF CONTAMINANTS IN SEDIMENTS.. ..... 15
TABLE 4: CONCENTRATIONS OF CONTAMINANTS IN GROUNDWATER. .. 15
TABLE 5: CARCINOGENIC TOXICITY VALUE FOR CONTAMINANTS OF
CONCERN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
TABLE 6: NONCARCINOGENIC TOXICITY VALVES FOR
CONTAMINANTS OF CONCERN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 20
TABLE 7: CLEANUP L'EVELS FOR CHEMICALS OF CONCERN. . . . . . . . . . .. 23
TABLE 8: SUMMARY OF CLEANUP ALTERNATIVES.. . . " . ... . .... ... .. 24
TABLE 9: COMPARISON OF THRESHOLD AND BALANCING CRITERIA. . .. 31
TABLE 10: COST ANALYSIS OF ALTERNATIVES. . . . . . . . . . . . . . . . . . . . . ".. 36
TABLE 11: PERFORMANCE STANDARDS FOR GROUNDWATER.. ... ..... 38
TABLE 12: PERFORMANCE STANDARDS FOR SOIL. . . . . . . . . . . . . . . . . . . .. 41
TABLE 13: FEDERAL ARARs FOR MARZONE SITE OUI . . . . . . . . . . . . . . . . .. 44
TABLE 14: STATE ARARs FOR MARZONE SITE OUI .................... 46
TABLE 15: TO-BE-CONSIDERED (TBCs) DOCUMENTS FOR MARZONE
SITE OUI .................................................. 46
-------
FIGURE 1:
FIGURE 2:
FIGURE 3:
FIGURE 4:
FIGURE 5:
FIGURE 6:
LIST OF FIGURES
Map of Marzone Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Site Layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Site Geology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Site Hydrology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
Toxaphene Contamination in Shallow Soil. . . . . . . . . . . . . . . . . . . .. 12
Xylene Contamination in Groundwater. . . . . . . . . . . . . . . . . . . . . .. 13
-------
RECORD OF DEOSION
MARZONE, INC./CHEVRON CHEMICAL COMPANY SITE
OPERABLE UNIT #1
TIFT COUNTY, GEORGIA
1.0 SITE NAME, LOCATION, AND DESCRIPTION
The Marzone, Inc./Chevron Chemical Company Site (herein after the Marzone Site or
the Site) is located in south-central Georgia in the City of TUton, at the intersection of
Golden Road and Norfolk Southern Railroad (Figure 1). The Site consists of two
separate study areas called operable units (OUs). This Record of Decision covers
FatWD
\IIOCD
'DIEAnHG
FACIUIY
I~,,~NQ
-'
c.-..c_.
--
---
---
.... .....
f
o
.m StRR~
MARZO!-£. r;c m
- . - ,.. -
FIGURE 1: Map of Marzone Site
QU1.. QU1 consists of the l.68-acre former pesticide production area, a part of the
adjacent Slack property, and part of the adjacent railroad drainage ditch.
Although the property is accessible from all directions, the only roadway access is
from Golden Road which borders the property to the north. Across Golden Road to
~ecord of Decision (OUI)
Marzone, Inc./CJ\evron
-------
the north is a former lumber mill. To the west of the property is an active railroad
and a former wood treating facility. To the east and south is residential property
owned by Mr. Grover Slack, which includes an open barn and horse pasture. A live-
in trailer is also present on the Slack property. A municipal drinking water supply
well is located less than 100 yards to the northwest. Farther to the north and west of
this well is a residential area. Also, approximately 500 feet east of OUI of the Site is
a red brick house. .
Bordering the southern p~rtion of OUI of the Marzone Site was a former shed arid
planing mill, of which only an asphalt area remains. Further south of the Marzone
property was a former burn pit area used to burn planing mill wastes. Beyond the
former burn pit area to !the southeast is the Golden Seed property where a former
fertilizer facility was operated. Currently EP A is performing a fund-led removal
action on the Golden Seed Property.
Existing features on OUI of the Marzone Site include the plant building (which
formerly consisted of a dry blending area, a warehouse, a drum storage area, and a
liquid formulation area), a vertical chemical storage tank, an adjacent tank pad, a
loading dock area, and an asphalt parking area and concrete slab (Figure 2).
Reportedly, an underground storage tank is located north of the eastern portion of
the building. A drainage ditch runs along the southern boundary of the Site and is
referred to as the "south drainage ditch." Similarly, another drainage ditch, referred
to as the ''railroad drainage ditch," runs along portions of the Norfolk Southern
Railroad and the railroad spur south and southeast of th,e Site. Former features on
OUI of the Marzone Site were a. rinsate pond (lagoon) in the southeast portion of the
Site, and a former truck loading .~rea in the eastern portion of the Site. Additionally,
there was an aboveground chemical tank area on the south side of the Site, of which
only the tank pad remains.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
The pesticide formulation facility was developed in 1950 and operated as such until
January 1983. After 1983, OUI of the Site was used primarily for general storage and
plant seedling distribution, as well as vegetable washing and repackaging activities.
Currently, no operations exist on OUI of the Marzone Site.
From 1950 to 1970, Chevron Chemical Company operated a pesticide formulating
plant at OUI of the Site. From 1950 to about 1960, Chevron formulated dry pesticide
dusts and in. 1960 liquid formulation was added. The liquid formulation used xylene
and xylene-based mixtures as carrier liquids. Bulk chemical handling facilities
operated during these years included unpaved railcar and truck loading areas for
base materials and finished products; bulk liquids were unloaded by tanker truck
into vertical aboveground storage tanks. Only the western portion of the current
building was in existence. The remainder of OUI was unpaved.
Record of Decision (OU1)
Marzone, Inc./Ctevron Ctemical Company Site
2
-------
~
~
N
~
en
....
nr
~
8
~
!IO
,
o ~
-...I. ..
COAl't"C $C...t ,. m I
ow
.I
~ f'
y. --,
-_. 'I"O~IIC~ T~IICIC --.
U)ADINL' AII£~ -------.
-1"Ofll/lfI U(J(JON/ --
,tCNCflCI( fI'NSAflI'OND. .... '---
. . ....... ........................... .' -- I
r ..~. /
SOUtH Oft_Aet
DOlt>!
1"O~lllfl :lnfD
- CX/SIINO l.uoc PMj/
lOftI/Cft OICUtCAl
IAMI MCA
\(ftncAl CHOI1CAI.
S !MAC!: TAH(
UOUIDI rCIIIMAItCN A~CA
-w-
- - DftUOI 5101A(;( A~CA
lOID/NO COOl
-- C~T 8ltNOINQ ARU
LEGEND
[JUSltNO flCMjWAT
trlS lING /nICt
,.
-I-.-t-
OQSIINQ I....OtO
Dolt>! IX.I[II\.I
-------
In 1970, Chevron sold the facility to Mr. Billy Mitchell who founded the Tifton
Chemical Company which formulated and marketed liquid and dry pesticides similar
to Chevron's. These included DDT, toxaphene, parathion, methyl parathion,
malathion, and chlordane; Tifton Chemical Company also produced sulfur-based
products.
Tifton Chemicals sold the operation in 1977 to Tifchem Products, Inc. Inspections
made by the Georgia Department of Natural Resources (GaDNR) indicated repeated.
. rinsate discharges to unlined drainage ditches leading to the former rinsate pond
(lagoon) located at the southeast comer of the property, off-site discharges, and poor
housekeeping practices inside and around the buildings. It is likely that Tifchem
formulated common organophosphate and organochlorine pesticides. GaDNR records
mention atrazine, endrin, and toxaphene in connection with this operation. Tifchem
defaulted to the Farmer's Bank of Tifton in 1979 leaving large quantities of pesticides
on-site.
Marzone Chemical Company (Marzone) purchased the property in January 1980, and
operated it as a pesticide formulating facility until September 1982. Marzone
reportedly formulated methyl and ethyl parathion, toxaphene, lindane, DDT,
chlordane, Sevin, atrazine, malathion, and heptachlor at the Site. Prior to operation,
Marzone was required by the GaDNR to remove the estimated 70,000 pounds of
pesticides which remained at the Site from the Tifchem operation. GaDNR also
required Marzone to close the rinsate pond (lagoon) and replace it with a system
resulting in zero discharge. The pond water and sludge ireportedly were disposed at
the Pinewood disposal facility in South Carolina. /
In 1983, regular commercial operation of the Site ceased when Kova Fertilizer, Inc.
(Kova) acquired the property in a foreclosure. A GaDNR inspection of the Site,
following Kova's acquisition, identified open drums of pesticides and pesticide
wastes on-site. In 1984, a notice of violation was issued and the GaDNR required
Kova to remove all hazardous waste, contaminated soil, and debris from the Site
within 45 days. Kova manifested 49 drums of pesticide waste for off-site disposal by
Chemical Waste Management. In May 1985, ownership was transferred to Kova of
Georgia.
In August 1985, the Site was purchased by Milan, Inc., the current owner of the Site.
The Site has been used for general storage, plant seedling distribution, and vegetable
washing and repackaging. A fence to secure the Site was added in May 1993.
To date a number of Removal Actions have been taken at the Site. Records of the
Georgia Environmental Protection Division (GaEPD) identified concerns at the Site as
early as 1973. In 1979, Marzone, Inc. in response to a GaEPD compliance order,
removed waste from the rinsate pond. Marzone reported that they removed 35 tons
of sludge from the rinsate pond area. The rinsate pond was filled with compacted
Record of Decision (OUI)
Marrone, Inc./Olevron OIemical Company Site
4
-------
I -- - - - --
topsoil and clay. Analyses ot'the sludge samples identified atrazene, lead, and
arsenic. An additional 5 tons of pesticide wastes were removed by Kova Fertilizer,
Inc., under GaEPD's direction in March 1984. In September 1984, the EPA conducted
an investigation at the Marzone Site. Analyses of soil and water samples collected at
the Site, indicated that pesticides, including endurin, heptachlor, DDT, chlordane,
toxaphene, atrazene, methyl and ethyl parathion, lindane, DDD, and malathion were
still present in the soil and/or groundwater. In October 1984, based on the results of
the investigation, EP A initiated response actions at the Marzone Site. Approximately
1,700 tons of waste were reportedly removed from the Site and disposed of at a
permitted hazardous waste landfill. In May 1985, Chevron contracted with OH
Materials Co.' for an additional removal of contaminated materials from the rinsate
pond and drainage ditches. Approximately 2,200 tons of material was removed
during this action. These removal actions were conducted to abate substantial threats
to human health and the environment. Residual risk of a lesser degree remained at
the Site subsequent to the emergency removal actions.
The Marzone, Inc./Chevron Chemical Company Site was proposed for the National
Priorities List (NPL) in June 1988, and became final in August, 1989. In September
1990, Kova Fertilizer, Inc., Kova of Georgia, Chevron Chemical Company, and Billy
G. Mitchell, signed an Administrative Order by Consent (AOC) with EPA for the Site.
The AOC directed the PRPs to develop and implement a Remedial Investigation/
Feasibility Study (RI/FS) which identified the nature and extent of contamination and
proposed remedial action for the Site. The RI report presents the methods, results,
and conclusions of the investigation. The FS report includes development, screening,
detailed analysis, conclusions and recommendations for the Remedial Action
Alternatives. .
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
On June 24, 1991 an availability session was held in the Tifton Neighborhood Services
Center, on Golden Road to inform the community of the start of field work for the
Remedial Investigation. At that time community interviews were conducted and a
repository was set up at the Tifton and Tift County Libraries in Tifton, Georgia. A
second availability session took place on January 20, 1994 in the Neighborhood
Services Center to inform the public of the results of the Remedial Investigation and
the proposed alternatives for remediation.
On April 7, 1994 a third availability session was held to better define the remedial
alternatives presented in the Feasibility Study. In addition, on January 5, 1994, EPA
held a public meeting in the Tifton Library to announce that Tifton/Tift County,
Georgia was selected as Region IV's focus for the Environmental Justice initiative. At
that time a summary of the activities at the Marzone Site was presented. .
Record of Decision (OUt)
Marzone, Inc./Otevron Otemical Company Site
5
-------
The public comment period on the proposed plan was from July 15, 1994 through
September 14, 1994. A public meeting was held on July 26, 1994 where
representatives from EP A answered questions regarding the Site and the proposed
plan under consideration. The administrative record was available to the public at
both the information repository maintained at the Tifton and Tift County Libraries
and at the EP A Region IV Library at 345 Courtland Street in Atlanta, Georgia. The
notice of availability of these documents was published in the Tifton Gazette on July
11, and July 18, 1994. Responses to the significant comments received during the
public comment period and at the public meeting are included in the Responsiveness
Summary, which is part of this ROD in Appendix.A.
4.0 SCOPE AND ROLE OF OPERABLE UNITS
EP A has organized the work at this Site into the following two phases or operable
units (OUs). These units are as follows:
OU #1:
Contamination on l.68-acre former Marzone pesticide formulating area,
part of the Slack property, and railroad drainage ditch past the
southwest comer of the horse pasture, and contaminated groundwater
underlying OUI of the Site.
OU#2:
Remaining soil sediment and surface water contamination- including,
but not limited to, contamination in Gum Creek. The Site was broken
into operable units when contamination was discovered at Gum Creek
and at the Golden Seed removal Site.
The Site was separated into operable units to expedite the cleanup of the major
sources of contamination. The 1.68 acre formulating area is the main source of
contamination from the Site. This contamination has spread, mostly through surface
water runoff, to other nearby area including the drainage ditches and Gum Creek.
Additional studies are necessary for OU2 to determine the extend of contamination in
Gum Creek. Currently, sufficient information is available only to select a remedy for
OUI. The OU2 studies will take some time to complete and a separate ROD will be
issued for the remediation of OU2.
Record of Decision (OUI)
Marzone, Inc./Olevron OIemica1 Company Site
6
-------
5.0 SillviNIARY OF SITE CHARACTERISTICS
5.1 General Site Conditions
Tift County consists of uplands, river terraces and floodplains with moderately wide
interstream divides separating relatively broad valleys. The surface expression of the
divides is generally level, very gently sloping or undulating, while the valley walls
have modest slopes and nearly level valley floors. Tift County experiences a humid
temperature climate. Winters tend to be short and mild, while the summer season is
typically long and hot, occasionally tempered by Gulf and Atlantic winds. The
average annual precipitation is reported to be approximately 48 inches; with the
greatest sustained rainfall occuning during winter months when evapotranspiration
is lowest. The area's winter temperature average 52 degrees Fahrenheit (F), while
summer temperatures average 80 degrees Fahrenheit. The Site is situated within the
drainage basin of the southeast-flowing Alapaha River. Local drainage is
accomplished by overland flow to Gum Creek which discharges to TyTy Creek, a
tributary of the Alapaha. Drainage patterns exhibit dendritic drainage.
5.1.1 Ge010gy /Soil
Tift County is located in the Coastal Plain Physiographic Province of south Georgia,
which is composed of a wedge of clastic and carbonate sediments ranging in age
from Jurassic/Cretaceous to recent. The sediments represent both nonmarine Oand-
derived) and marine (oceanic and/ or estuarine) sources. The uppermost geologic unit
occurring in the Site area is the Miocene age Hawthorne Group which has two major
facies: a nonmarine composed of the Coosawhatchiue Formation, the Marks Head
Formation and the Parachuch1a Formation, and a marginal marine/nonmarine facies
composed of the Altamaha Formation. The Hawthorne ~roup occurs at ground
surface in the Site area and extends in some areas to an approximate depth of 300
fe~t below grade because of depositional features such as the Gulf Trough. The
Hawthorne is composed of interbedded clay and clay with limestone, with minor
beds of sand, sandy clay, sand-silt and clay, and limestone. The Hawthorne Group is
a confming unit in the Site area, overlying a major water producing source at greater
~~ '
The Hawthorne Group is underlain by the Oligocene Suwannee Formation. In the
Site area the Suwannee occurs at a depth of 300 feet below grade or more. It is
composed of monolithic limestone, which is locally cavernous. The Suwannee
represents the Floridan Aquifer System in this area of Georgia and is a significant
source of potable water supplies in the Site area.
Site area geologic units are depicted on Figure 3, a cross section drawn throughout
the alignment of three municipal water supply wells illustrated on Figure 4.
Record of Decision (OUI)
Marzone, Inc.fChevron Chemical Company Site
7
-------
['CYOf«Jn
in ...~ NGVD .
1". ':50
.-
Iy.
I 2~
IIIOC£HC ".
HAWlHORH(
fORlU.llOH
,
--1- 50
I $co LcYd
tJUCOCCIl(
SUW.vUn:C -50
fOR1/1011ON
!
I
,
"!
LEGEND
-
NORTH
SOUTH
IW'
(Ie""."",
150
Sea lCftl
1W5
J50
:. ":':;"/."'::":!;;..:~
'" -"-
150
50
-150
-150
.
.
-.00 - a
-260 - a
-2(;7 -.R
1000 0, 1000
c::::>-:.c::>-- . .
I~ORllONrN.. ....
~CAU 1/1 Fca
r:<:".:.i <"..~
._0...'".:. ~
. 'I:L':""...f."~ WID. slq .cv.y
~ ~ cu.y
:!..
:!...
y
~ cu.y ~ CAVCRIfQllS lIU(STON(
~ UU(STONC 0 WEll. CASING
~. C1AY wrrH UI.I(STON£ fl OP(H IIOU:
Surficial Water Bearing Zone Water Level (MW-SS)
Intennediate Zone Water Level (MW~H)
Roridan Aquifer Potentiometric Surface (1W7)
Figure 3 : Site Geology
-------
This cross section illustrates the predominantly clayey nature of the Hawthorne
Group as it underlies the Marzone Site. A low-permeability sandy clay overlays a
thin sand bed extrapolated to extend through the cross section between the widely
spaced wells. The thin sand bed is located more than 50 feet below grade and is the
only apparently continuous potentially water-bearing zone within the Hawthorne
underlying the Site. All of the remaining Hawthorne strata are interpreted to be fme-
grained, low-permeability materials. This was confumed in the borings conducted
during the Remedial Investigation (RI). Immediately underlying the Hawthorne
Group is the Suwannee Formation's limestone. It is characterized as a relatively soft,
cavernous carbonate rock.
5.1.2 Hydrology
Regional hydrogeology is dominated by the Floridan Aquifer System made up of the
Hawthorne Group and the Floridan Aquifer. The system is recharged principally by
rainfall and stream flow in its outcrop area some 25 miles northwest of the Site. The
Site and surrounding area is not a recharge area. The Hawthorne Group is a
300-foot-thick regionally extensive confining unit. It is chiefly composed of clays and
similar fine-grained materials of limited permeability and storage capability. These
soil promote runoff while limiting infIltration. In the study area, the first water-
bearing unit in the Hawthorne Group was encountered at a depth of 3 to 6 feet
below grade. Because of its primarily fme-grained character, the Hawthorne contains
numerous perched or ephemeral (seasonal) accumulations of water. The
,Hawthorne's shallow water-bearing zones may occur separately, merge or pinch out
completely within short lateral distances across the Site.
Site drainage is accomplished by overland flow to dra~ge ditches which directs
flow toward Gum Creek. The drainage ditches from the'Site discharges through a
~vert into a marshy area surrounding Gum Creek. Trenching has been done by the
railroad along the spur. The trench appears to collect culvert discharge water which
would otherwise percolate through the soil to the water-bearing zone below. Gum
Creek is primarily a wet-weather stream consisting of a series of pools and small
riffle areas.
5.2 Results of Site Remedial Investigation
The PRPs of the Marzone Site completed a Remedial Investigation (0) and Feasibility
Study (FS) of the Site under EPA's oversight in 1994. The RI was designed to
determine the nature and extent of contamination in order to select a cleanup
remedy. The investigation for the Site consisted of two work phases: Phase I-a field
screening and confirmation sampling, and Phase 2-an additional investigation
phase. The screening included the collection of groundwater, soil, sediment, surface
water samples for on-site analysis, and a soil gas analysis. The confirmation stage
Record of Decision (OUI)
Marzone, Inc,fOtevron Otemical Company Site
9
-------
. ~-
~
~
II:>-
C.f)
....
~ SOUTHWEST
~ DM.:!
a
-
0
~
-10-
NORIIIEASI
DM.4
C'Ulln., SII,lulI:
. ,.. ..
SHAll OW WA / C R
aeARING IONC
.... .. ,.,.. .. ..... .. .
10
-20- - .10 seCONDARY
WA/CR aCARI/.
lONe
-30- - -.10
~o 0
.~-
". '..- '" H0R110!lTAL
. SCAl[ IN rm
50
.
LEGEND
--
~
~~
~~"'>J
.~'"':~.':;.;~,
..'... '-'
SANOY Sit r
SAND
~.....
~":'.;\:::
. --.-',-
~
CLAY
SillY SAN!)
I'~,
-------
scope of work included the installation of monitoring well pairs and the collection of
soil, groundwater, sediment, and surface water samples.
During the Phase 1 field investigation, samples were also collected and analyzed for a
variety of physical, geochemical, and microbiological data. After EPA's review of the
Phase 1 RI Report (March 1992), Phase 2 field sampling was conducted beginning in
September 1992. This phase of work focused on the southern drainage ditch and
Gum Creek areas downgradient of the Site. Additional upgradient and background
data were also collected. The additional tasks performed included monitor well
installation and soil, sediment, surface water and groundwater sampling, and
analysis. A total of 15 monitor wells (12 in July 1991 and 3 in September 1992) were
installed on and adjacent to the Site for groundwater characterization. Soil samples
were collected from 15 soil boring and from 8 monitor well locations. Drainage ditch
sediment samples were collected from 20 locations to assess the impact of runoff
from the Site toward Gum Creek. Seven surface water and ten sediment samples
were collected from Gum Creek to assess the nature and extent of contaminants in
the creek and marsh area.
The most common chemicals identified in the soil were toxaphene, DDX and BHC
isomers. These are pesticide associated chemicals that were detected in more than 50
percent of the samples collected. Toxaphene had the highest concentration in OUI at
2,300 mg/kg. DDT was detected at a maximum concentration of 1,300 mg/kg.
Other common chemicals include xylenes, parathions, and atrazine. These were
among the most commonly formulated pesticides or carriers used at the Site. The
areas of highest concentrations in the soil and sediments were the liquid formulation
area, the south drainage ditch, the "Slack" property south of the formulating area
(vicinity of the former planing mill), and the Golden Seed property. These
contaminated soil are near the former and current potential source areas and their -
surface water drainage pathways (Figure 5).
The most prevalent chemicals in groundwater are BHC isomers, xylenes, DDX, and
atrazine. Xylenes had the highest concentrations at 94 mg/I. The areas of highest
organic concentrations in groundwater are near the railroad loading dock and the
"Slack" property south of the formulating area near the planing mill. The
contaminants identified in the wells generally correspond to a nearby current/past
source or areas of high contaminant concentrations in soil.
Record of Decision {OUn
Marzone, Inc./C1Ievron Otemical Company Site
11
-------
:!1
i
C.n
..-J
o
~
P"
ro
='
ro
()
f
I»
=-.
o
::s
~
tJ')
~
o
~
C/'J
o
=:
~'-'-7
. 0
I ~ /
L._.J;-
.."
.1<0
GOWEN SUO
SITE -..-..
,~,
. . . - ..
....~ ~
__..",1
-['.:::::.:::::::::::. - . ...
'-. _...-.!;..
\ -'-r
lOP "'f
o \ t'
~.8CJlIn4[MfWt.I/DI'D
~.:..........
1
\
ICI.
0\
LEGEND
-.-.-.-
I I I
. alnNG nM:8
.fC)I)tI"f1olO~
--..-...
_NCA
etrO<-.-
af'fWlt.11fIIIP\.tIII'
MY '.'....-o~.....u
1Irf. ,.lCI\MDto8H1lNM'U
lOOT DmCT1D
---
"'-
to-
t-
--;!
IZZZZJ
-..,-.
.
o
.
If)
TOXAPHENE IN SHALLOW SOIL
AND ~I:DIMENTS
MAAZONE. INC. SITe
-------
'-
, -
'---. '-- --
--""-"---. ~..--
-'~F
I ~
, "/
.. ~/ "
I I'
;"
.-.:;1-"
'L -'- "
1 .---' .
Ir-- ,.
:31
~
CO
0\
~
~
tI)
n
o
I.
r::r.
o
='
$"
C)
'"1
o
5
Po.
~,
fir
'"t
00
I
.
....
....
I
~
...................
OOlU(H n~o
SIT!
. - ..
"""""" IO\IftOUO<....-o
\
\
\
I
I
I
I
I
I
I
I
I
\
It
\\
.
\
\
\
LEGEND
"'mod"""
I>Omod-
---...
#rCTOM I#CA
ClIOO-
OnWATV\fI\W
LUI.'_Io2WQ1.
117f. '-~NO'MU
00' DnIC11D
.. - fo04
'-
.,-
&..,....
-.-.-.-
12222'.1
_'0'_.
.
II
.
00
--,
-------
.
AMBIENT AIR2
CONTAMINANT <:;1 CONC~TION
(m~/m )
A trazine 83x1fF5 1.9xlOo13
a-BHC S.2xlO-7 l.2xH)"lS
a~ordane 1.OxlO-s 23xl()"14
"t-Chlordane 4.9x1
-------
TABLE 3: CONCENfRATIONS OF CONTAMINANTS IN SEDIMENTS
CONTAMINANf MAXIMUM
~ONCENTRATION DETECTED
me/kg:)
a-Chlordane 12
¥-Chlordane 14
DDD 32
DDT 17
Dieldrin 2.4
Endosulfan I 3.4
Endosulfan II I 2.0
Endrin 73
Heptachlor 19
Heptachlor Eooxide 2:7
Lindane 2.7
Toxaohene 540
Cooner 938
Zinc 3050
CONTAMINANT MAXIMUM
CONCENIRATION DETECTED
(me/L) ,
Benzene -" 60
a-BHC 60.3
8-BHC 98.5
O-BHC 23.8
DDD 7.6
DDT 93
Endrin 5.8
Ethvlbenzene 6100
Lindane 54.6
Methvl Parathion 47.0
Xylene 94000
Arsenic 59.5
Chromium 180
Lead 34.4
Zinc 6390
TABLE 4: CONCENTRATIONS OF CONTAMINANTS IN GROUNDWATER
Record of Decision (CUI)
Marzone, Inc./Otevron OIemical Company Site
15
-------
Three potential routes of chemical migration were identified at OUI of the Site.
These routes are:
1. Surface transport via surface water and sediment runoff from
OUI of the Site,
Vertical transport through the soil by desorption of chemicals
bound to the surface soil and percolation of chemically enriched
water through the soil column, and
Vertical and horizontal transport through the groundwater
matrix.
2.
3.
5.2.1 Soil Migration J
Migration of pesticides 'is primarily limited to surface migration via storm water
runoff. The railroad drainage ditch sediments were found during the RI to contain
elevated levels of chemicals associated with pesticides. Storm water runoff which
carries the contaminated fine soil particles apparently has deposited these particles
into the drainage ditch. The drainage ditch slopes from the formulating area toward
Gum Creek, flattening as it approaches the creek (Figure 5). Sediment deposition
apparently has occurred in flat areas as the periodic ponding of the water has
allowed sediment particles to settle. In general, pesticide concentrations decrease
along the ditch away from the Site. However, the concentrations increase near the
Golden Seed property.
5.2.2 Groundwater Migration. .
Former source areas have contributed to the contamination in groundwater. The data
indicate toxaphene and DDT as the main soil contaminants. The chemical
characteristics of toxaphene and DDT indicate that these chemicals have limited
vertical mobility in soil. Contaminants found in the groundwater, for example:
parathion, lindane, and atrazine, are more mobile and have therefore, percolated into
the shallow groundwater. DOT was detected in only one shallow well, indicating
that little vertical migration of DDT into groundwater has occurred. Toxaphene was
not present in the groundwater, indicating that migration of toxaphene is sufficiently
retarded by sorption to soil and that groundwater has not been impacted. Computa-
tions of both toxaphene and DDT migration was calculated; the total horizontal
distance traveled in the aquifer is less than 1 foot. However, other chemicals,
including xylenes, ethylbenzene, BHC isomers, and methyl parathion were detected
in groundwater (Figure 6).
Record of Decision (OUl)
Marzone, Inc./Otevron Otemica1 Company Site
16
-------
6.0 SUM1viARY OF SITE RISKS
CERCLA directs EP A to conduct a baseline risk assessment to determine whether a
Superfund Site poses a current or potential threat to human health and the
environment in the absence of any remedial action. The baseline risk assessment
provides the basis for determining whether or not remedial action is necessary and
the justification for performing remedial action. Based upon this analysis it was
determined that the soil and groundwater pose a potential risk.
The major risk currently associated with OUI of the Marzone Site is the ingestion and
dermal contact of contaminated soil. In addition, there is a risk posed from the
ingestion of the contaminated groundwater underlying the Site. Actual or threatened
releases of hazardous substances from this Site, if not addressed by implementing the
response action selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
6.1 Chemicals of Concern
The majority of the wastes and residues generated by production operations at the
facility have been managed, treated, and disposed of on-site throughout the Site's
history. The chemicals measured in the various environmental media during the RI
were evaluated for inclusion as chemicals of potential concern in the risk assessment
by application of screening criteria. The criteria which resulted in elimination of
chemicals included: chemical concentrations below background concentrations;
measurements below quantification limits; a combination of low toxicity and low
concentration or low persistence and low concentration iUtd low frequency of
detection.
See tables 1 through 4 for contaminants of concern identified at the Marzone Site
aUI.
6.2 Human Health Risk
This Baseline Risk Assessment (BRA) characterized potential current and future risks
to human health and the environment from exposure to chemicals found at the Site.
The BRA reviewed several potential exposure scenario~ for the Site: current industrial
or site visitor scenarios, and future hypothetical residential scenario. The BRA
showed that under current scenarios, the exposure pathway that exceeded EPA's
acceptable cancer risk range of 1 x 10--4 to 1 x 10~ and/or an acceptable Hazard
Index of 1.0 was direct contact with surface soil (Le., incidental ingestion, dermal
contact) for the site visitor and on-site worker. Under the future residential scenario,
ingestion of groundwater and direct contact with surface soil were the exposure
pathways exceeding this risk range. Hence, based on the results of the BRA, the
media of concern for remedial action are surface soil and groundwater. In addition,
the subsurface soil is a media of concern because of potential.cross-media chemical
transport from subsurface soil to groundwater. Surface sediment is not a media of
Record of Decision (OUI)
Marzone, Inc./Chevron Otemical Company Site
17
-------
concern at the Site because even the most conservative risk estimates generated in the
BRA showed that exposure to chemicals in surface sediment resulted in excess cancer
risks well within EP A's acceptable risk range. The BRA showed that assuming
industrial use of the Site resulted in the highest estimated carcinogenic risks under
current land use conditions. For noncarcinogenic risks the site visitor scenario
yielded the highest risk. This is due to the differences in the exposure duration
values used in the exposure assessment calculation. Estimated carcinogenic risks for
workers exceeded 1x10-4 only for surface soil pathways (i.e., incidental ingestion and
dermal contact). Surface soil is defined as the top 1 foot of soil. The chemical
contributing the most to estimated risks from exposure to chemicals in surface soll
was toxaphene (estimated risks were about one order of magnitude greater than for
any other chemical). I .
Under a future residential scenario, the only exposure pathways that resulted in
estimated excess cancer risks exceeding 1 x 10-4 were ingestion of and dermal contact
with surface soil and hypothetical ingestion of groundwater. For noncarcinogenic
endpoints, these pathways resulted in hazard indices greater than 10. As with the
industrial scenario, the most important contributor to estimated cancer risks from
surface soil was toxaphene. For noncarcinogenic endpoints, the most important
contributor to estimated risks from surface soil was DDT. For groundwater, site-
related chemicals contributing the most to estimated cancer risks were the (1-,15-, and
y-BHC isomers, while for noncarcinogenic endpoints, the site-related chemicals
contributing the most to estimated risks were y-BHC and methyl parathion.
6.3 Summary of Exposure Assumptions .
The Baseline Risk Assessment utilized the following exposure assumptions for the
pathways identified at the Site.
Current Worker - The BRA assumed an on-site worker with 8 hours of
exposure a day, at 250 days per year, for 25 years. It assumed a 70 kg. adult
that would incidentally ingest 50 mg of soil per day. Skin on hands and
forearms were also assumed to be exposed to on-site soil.
Current Visitor - The BRA assumed a 9-18 year old visitor with an average
body weight of 50 kg. who is exposed 80 times per years for 4 hours per visit
for 10 years. Incidental ingestion was assumed to be 100 mg of soil for each
visit to the Site. The skin on the head, hands, forearm, and lower legs, were
assumed to be exposed to on-site soil. The exposure dose from sediment was
assumed to be one-tenth of soil exposure.
Future ReSident - A 70 kg. adult was assumed for an on-site resident for 350
days per year for 24 years. Also a 15 kg. .child resident was assumed to be
exposed for 350 days per year for 6 years. The adult and child were assumed
. to ingest 100 mg. and 200 mg., respectively, of on-site soil per day of exposure.
Record of Decision (OUI)
Marzone, Inc./Chevron Ctemical Company Site
18
-------
The skin of the head, hands, foreanns, and lower legs of the child and adult
future residents were assumed to be exposed to on-site soil. The adult and
child assumed to be ingest 2 liters of and 1 liter of water per day, respectively,
for the exposure frequency and duration stated above. A resident was also
assumed to shower daily with Site groundwater. The exposure to sediment
was assumed to be one-tenth that of soil exposure.
6.4 Summary of Toxicity Values
The following is a summary of the carcinogenic and noncarcinogenic toxicity values
for contaminants of concern at Marzone OUI.
TABLE 5: CARCINOGENIC TOXICITY VALUE FOR CONTAMINANTS OF
.. CONCERN
SLOPE INGESTION DERMAL
FACI'OR SLOPE FACTOR SLOPE FACI'OR,
CONTAMINANT INHALATION (mg/kg~y>-l (mg/kg~y)-l
(mg/kg-day)-l
Atrazine NA 2.22x1O-1 4.44x10"1
Arsenic 15.1 1.75 8.75
Benzene 2.91xl0"2 2.9xlO,"2 3.6xl0"2
a-BHC 63 63 12.6
6-BHC 1.8 1.8 3.6
a-Chlordane 13 13 , 2.6
y-Chlordane 1.3 1.3 " 2.6
Chromium M) 4.2x10+1 NA NA
DOO 3.4x10"1 2.4x10"1 4.8x1O"1
DOE 3.4x10"1 3.4x10"1 6.8xl(tl
DOT 3.4xlO"l 3.4x1(t1 6.8xlO"l
Dieldrin 16 16 32
Heptachlor Epoxide 9.1 9.1 18.9
Heptachlor 4.55 4.5 9.0
lindane NA 1.3 2.6
PCB-1260 NA 7.7 15.4
Toxaphene 1.12 1.1 2.2
NA = Not Available
Record of Decision (OUI)
Marzone, Inc./Olevron Otemical Company Site
19
-------
TABLE 6: NONCARCINOGENIC TOXICrIY VALVES FOR CONTAMINANTS OF CONCERN
CONTAMINANT INHALATION RID INGESTION RID DERMAL RID
(mg/kg-day) (m~/kg-day) (mg/kg-dav)
A trazine NA 0.005 0.0025
Arsenic NA 0.003 0.00006
a-chlordane NA 6.Ox1W 3.Ox1as
'"tChlordane NA 6.Ox1W 3.Ox1as
Chromium (VI) 5.71xm-7 0.005 0.001
Copper ! NA 0.037 0.0074
DDD NA 5.Ox1~ NA
DDE NA 5.Ox1~ NA
DDT NA 5.Ox1~ 0.00025
Dieldrin NA 5.Ox1W 2.5x1as
Endosulfan I NA 5.Ox1a-s 2.5x1as
Endosulfan n NA 5.Ox1a-s 2.5x1as
Endrin NA 0.0003 0.00015
Ethvlbenzene 0.286 0.1 0.08
Heptachlor Epoxide NA 13x1a-s 6.5Ox1~
Heptachlor NA 5.00xl
-------
derived from the contaminant concentration in a given medium to the contaminant's
reference dose). A HQ which exceeds one (1) indicates that the daily intake from a
scenario exceeds the chemical's reference dose. By adding the HQs for all
contaminants within a medium or across all media to which a given population may
reasonably be exposed, the Hazard Index (HI) can be generated. The HI provides a
useful reference point for gauging the potential significance of multiple contaminant
exposures within a single medium or across media. An HI which exceeds unity
indicates that there may be a concern for potential health effects resulting from the
cumulative exposure to multiple contaminants within a single medium or across
media.
6.6 Environmental Risks
OUI of the Marzone Site consists of the major source areas near the main formulating
.area. Although these source areas are up gradient from Gum Creek, all sediments in
OUI were below levels of concern. Remediation necessary for Gum Creek will be
covered W\der OU2 of the Site. Any environmental risk issues related to Gum Creek
will be addressed in a subsequent ROD.
6.7 Cleanup Levels
Cleanup levels were established to ensure that any persons exposed in the future will
not be exposed to unsafe levels of site-related chemicals. Oeanup levels are either
the Federal Maximum Contaminant Limit (MCL) or the risked-based concentration.
EPA is requiring that groundwater be cleaned to a lxl£r risk level and soil be
cleaned to a IxIO~ or lxHrs risk level for cancer-causing contaminants. A lxHrs
cleanup will be required if the bioremediation option is ,selected and lxltr will be
required for all other alternatives. Both will be cleaned 'to an HQ of I for
noncarcinogens. These levels are consistent with EP A requirements for determining
cleanup levels within the lxlO'" to lxl£r range and are protective of human health
and the environment in a residential setting. EP A determines the amount of cleanup
necessary at a site by establishing health-based cleanup levels when Federal or state
standards have not been set for contaminants in soil or for some groW\dwater
contaminants. To determine these levels, EPA quantifies risk posed by cancer
causing contaminants and those known to cause other health effects. This risk range
of lx1o-' to 1xlO~ means that exposure to site-specific contaminants as defIned in the
risk assessment would result in an estimated increase individual chance of
developing cancer by one in 10,000 to one in 1,000,000. For non-cancer causing risks,
EPA compares the highest dose known to be safe (or not to cause harmful effects) to
the estimated dose from exposure to levels found at the Site to determine the cleanup
leveL
Using MULTIMED, soil cleanup levels were calculated for each contaminant of
concern for distances ranging from 0 to 25 meters from the source area. A
comparison of results indicated that a distance of 10 meters downgradient from the
source allowed attenuation and degradation of the contaminants and resulted in
Record of Decision (OU1)
Marzone, Inc./Clevron OIemical Company Site
21
-------
, --
cleanup levels that are protective of groWld water. The cleanup levels obtained are
feasible to implement. An exception to the 10 meter guideline was made for atrazine.
At 10 meters, the soil action level (SAL) for atrazine was below the detection limit. It
was appropriate to generate a cleanup goal 25 meters from the source area. The
cleanup goal remains protective of groWld water and is feasible to implement.
The SALs calculated using Mill TIMED for several of the contaminants were
extremely high, much higher than any concentration observed on-site. At a 10 meter
distance from the source, the SALs generated were:
a-BHC
(3-BHC
DDT
toxaphene
SAL (mg/kg)
1.26 x 1Q6
6.16 x lOS
3.48 x 1016
1.59 X 1015
Constituent
The values generated indicate that the concentrations present at the Site do not pose a
risk for these contaminants to leach from soil to ground water and are therefore
protective of ground water. Rather than assigning these high cleanup levels to the
contaminants, SALs generated to protect human health are the drivers for cleanup.
For MUL TIMED model assumptions and input parameters, see Appendix E of the
Feasibility Study Report, May 1994. Oeanup levels for Sjubsurface soil were
calculated and are represented in Table 7. /
Cleanup levels for chemicals of concern for surface soil and groundwater are also
shown on Table 7. Although these are not the only Site contaminants, EP A selected
these as chemicals of concern because of their toxicity, mobility, frequency of
detection, and the concentrations found on Site. Cleanup levels will be reached for
all contaminants of concern if met for these.
Record of Decision (OUl)
Marmne, Inc./Otevron Otemical Company Site
22
-------
TABLE 7: CLEANUP LEVELS FOR CHEMICALS OF CONCERN
SURFACE SOILb SUB- GROUND
(ppm) SURFACE WATER
HI=1 SOILc (ppm)
- CONSTITUENT 1x1cr 1x1(}-1i (ppm)
Atrazine 35.3 3.5 0.150
a-BHC NA 0.12 1.142 0.00003
ji-BHC I 0.547 0.0001
DDD 32.4 3.2 0.00077
DDE NA 2.28
DDT 22.9 2.29 0.00054
Dieldrin 0.49 0.049
Endosulfan II -2.6 2.6
Ethylbenzene 57.3 oJ'!
Heptachlor NA 0.085
Epoxide
:
Lindane 0.463 0.0002"
Methyl Parathion 4.55 0.0039
Toxaphene 7.1 0.7
Xylene 213 10"
.
Blank spaces indicate DO cleanup level set because the chemical is not a coe for the medium.
Surface soil cleanup levels are based on future residential land use. Cleanup levels are based on a cancer risk oC
1xlac. 1xl~ or a hazard index of 1.0. Surface soil refers to the top foot of soil.
Subsurface soil cleanup levels were calculated u$1g the MUL TIMED iDodel.
b
c
d
groundwater cleanup level based on MCL or safe drinking water level.
Record of Decision (OUI)
Mau.one, Inc./Ctevron Ctemica1 Company Site
23
-------
7.0 DESCRIPTION OF ALTERNATIVES
Nine alternatives are presented in this Record of Decision (ROD) for the remediation
of contaminated groundwater and soil in OUI. These alternatives are discussed,in
detail in the final Feasibility Study (FS) and caveat dated July 11, 1994.
TABLE 8: SUMMARY OF CLEANUP ALTERNATIVES
Alternative No.1 No action for Groundwater
Alternative No.2 Institutional Controls for
~ Groundwater
For Groundwater
Alternative No.3 Groundwater extraction and
carbon adsorption and
combinations of the above
Alternative No.4 No Action for Soil
Alternative No.5 Institutional Action for Soil
Alternative No.6 Excavation and landfill
disposal
Alternative No.7 For Surface and Bioremediation ban land
Subsurface Soil farming/compOs' \g
Alternative No.8 Low temperature thermal
desorption and combinations
, of the above
'
Alternative No.9 ChenrlcalChddation
GROUNDWATER
7.1 ALTERNATIVE NO.1 - No Action for Groundwater
The no action alternative for groundwater provides a baseline for comparing other
alternatives. Under this alternative, no further action would be taken at QUI of the
Site to remove or control groundwater contamination. QUI of the Site would be
monitored using existing wells to determine if any migration occurred. This
alternative relies on the natural process of dispersion, attenuation, and degradation
for reduction of pesticide concentrations.
Although no remedial action is to be taken for the no action alternative, groundwater
samples must be collected semiannually. No drilling cost would be expended, since
four selected existing monitoring wells would be used to collect the groundwater
samples. Q&M costs include collecting samples, laboratory analysis, and the an
assessment every 5 years. The present worth cost of the no action alternative is
$425,000. See table 10 for cost comparison.
Record of Decision (OUl)
Marzone, Inc./Otevron Otemical Company Site
24
-------
7.2 ALTERNATIVE NO.2 - Institutional Controls and Monitoring for Groundwater
This alternative includes the implementation of institutional controls and the
initiation of a long-term groundwater monitoring program. This alternative relies on
natural degradation to provide the reduction in pesticide concentrations. Institutional
controls will ensure that the shallow groundwater zone will not be used in the future,
thereby maintaining the current lack of exposure to, and risks from, chemicals in
groundwater.
The institutional controls to restrict access to contaminated groundwater may include
deed restrictions for OUI of the Site. They could include but not be limited to
zoning ordinances that prohibit use of groundwater in these areas. In addition, the
alternative would include the construction of a security fence to ensure restricted
access to the Site.
This alternative also includes a long-term monitoring program to monitor pesticide
constituents in the groundwater beneath and downgradient of the Site.
Approximately two additional wells will be constructed to act as groundwater
monitoring locations downgradient from the Site. The groundwater monitoring
program consists of sampling the new wells and four existing wells semiannually for
a period of 5 years. If after the period of 5 years data indicate stable or non-detect
pesticide concentrations, the monitoring schedule will be changed to a yearly event.
Although no active remediation is to be undertaken during the institutional controls
and monitoring alternative, the Site must be secured and groundwater samples
collected semiannually. Capital costs include labor / exp'enses for obtaining a deed
restriction, site fencing, and installation of approximately two wells. O&M costs
consist of collecting samples, laboratory analysis, and assessment every 5 years. The
present worth cost of the institutional controls and monitoring alternative is $775,000.
See table 10 for cost comparison.
7.3 ALTERNATIVE NO.3 - Groundwater Pump and Treat
This alternative consists of extracting the contaminated groundwater in the surficial
aquifer within OUI and treating it on-site through a filtration system and
enhancement through the use of an infiltration gallery. The used carbon filters would
be taken off-site for recharge and reuse of off-site disposal to an approved
incinerator. Approximately 2 groundwater recovery wells would be installed in the
area of the loading dock with possibly another 2 installed in the area of the rinsate
pond. The contaminated water would be pumped to an on-site water treatment
system, treated and passed through an infiltration gallery to enhance the movement
of contaminants through the aquifer. This alternative would also includes fencing to
prevent Site access to the public and periodic groundwater monitoring to track
changes in the level and extent of contamination. The major components of this
alternative would consist of:
Record of Decision (OUI)
Marzone, 1nc./CJ\evron O\emical Company Site
25
-------
.
The implementation of institutional controls described in Alterative No.
2.
The design and construction of groW1dwater extraction wells.
The installation of a security fence around the on-site treatment unit.
The design and installation of a groW1dwater fIltration system, a on-site
treatment system, and a retention and recycling system including an
infiltration gallery.
The start-up and operation of this system.
Transportation, regeneration, recycling, and disposal of the spent filters.
Operation of a long-term groundwater monitoring program.
.
.
.
.
.
.
The approximate volume of groundwater requiring remediation is estimated to be
300,000 gallons. Oeanup levels for groW1dwater are set out in Table 7 based upon
the results of the BRA. It is estimated that it will take 7-41 years to reach cleanup
levels. The present worth cost of the alternative would be $3.4 million. See table 10
for cost comparison.
SOIL
7.4 ALTERNATIVE NO.4 - No Action for Soil
The no action alternative for soil provides a baseline for comparing other alternatives.
Surface soil would still pose human health risks from direct exposure to the
contaminated soil. The subsurface soil contaminant, would pose a threat to
groW1dwater. This alternative will include some periodiCj monitoring of the soil to
determine if changes in extent or concentration occurs. i
Since tfiere is no active remediation, no capital costs will be required for this alter-
native. It will be necessary to sample these soil annually and prepare an assessment
every 5 years. O&M costs consist of collecting approximately eight soil samples
yearly plus laboratory analysis and reporting. The present worth cost of the no
action alternative is $425,000. See Table 10 for cost comparison.
7.5 ALTERNATIVE NO.5 - Institutional Controls and Monitoring for Soil
This alternative is similar to Alternative No.4 except that deed restrictions as well as
physical barriers would be used to restrict access to the Site. Deed restrictions could
include zoning ordinances that prohibit construction on, or use of, the Site during the
time that the soil remains contaminated above cleanup levels. Physical barriers would
include fencing, warning signs, etc. to prevent access to and use of the Site.
Securing of the Site and deed restriction costs have been included in the capital costs.
It will also be necessary to sample these soil annually and prepare an assessment
every 5 years, as with Alternative No.4. Verification of controls will also be
required. The present worth cost of this alternative is $675,000. See Table 10 for cost
comparison.
Record of Decision (OUI)
Marrone, Inc./O\evron OIemical Company Site
26
-------
7.6 ALTERNATIVE NO.6 - Excavation and Landfill Disposal
This alternative is for excavation of contaminated soil, off-site disposal at a permitted
landfill, and backfill with clean fill. It is estimated that 12,000 cubic yards of soil will
be removed to cleanup levels. This alternative also includes the demolition and
removal of some Site structures to provide better access to the contaminated soil. It
is a viable alternative for contaminated soil that do not contain a listed hazardous
waste or exhibit a hazardous waste characteristic. It would need to be coupled with
a treatment alternative for soil that exhibit a hazardous waste characteristic or contain
a listed hazardous waste.
The cost has been calculated based on the estimated volume for removal, disposal,
and replacement of 12,000 cubic yards with no treatment technology required for the
soil (all soil are assumed to be nonhazardous). The excavation, stockpiling, loading,
and disposal have a capital cost of $3.0 million which also represents the present net
worth. This includes the cost for fencing and initial Site clearance/building
demolition. See Table 10 for cost comparison.
7.7 ALTERNATIVE NO.7 - Bioremediation b Land Fannin Com ostin
This remedial alternative incorporates two separate biological processes operating
concurrently: biofarming through crop cultivation, followed by composting. These
processes are preceded by preliminary site preparation consisting of removal of
existing structures, and identification, removal, and disposal of biocidal pesticide
areas by excavation and landFill disposal. Biocidal pesticide areas are those hot spot
areas that have concentrations of pesticides above which bioremediation is
unsuccessful. This alternative assumes 3,500 cubic yardS of biocidal soil will be
excavated. -
The cropping operation would use local crops (e.g.,peanuts), which have a high lipid
content and so will accumulate higher pesticide residues. The harvested peanuts
would be composted to enhance further degradation of residual pesticides. Initially,
the harvested agricultural materials from OUI of the Marzone Site would be milled
with the crop residue to reduce the particle size for compost processing. The
composting operation would be seeded with materials from an existing cellulose
compost operation, thus introducing material with an established microbial
population. Milled material would be mixed with this established composted
material, and any contaminated solid associated with the cropping operation would
be added to the mixture. The mixture would be composted in static piles over a
manifold of forced aerators, and a leachate collection/recycling system would be
installed. Aeration will allow for control of aerobic conditions and will prevent odor
problems in the process. Once the compost has matured, it will be re-applied to the
cropping area to provide nutrient to the soil, which will enhance the growth of crops
and microorganisms. The biofarming/ compost cycle will be repeated until pesticide
concentrations reach target levels. The cleanup levels for this alternative are based
Record olDecision (OUI)
. Marzone, Inc./C\evron C\emical Company Site
27
-------
upon a 1x10-s risk-based level (Table 7).
In developing this remediation scheme, treatability testing and pilot-scale studies
would initially be conducted to assess full-scale application and identify basic
operating conditions. These studies would take approximately 1 year to complete. .
Based on an assumption of three cropping/composting cycles per year, initial cost
plus O&M costs for a 5-year treatment period are estimated at $2.7 million present
worth. This estimate includes $1.2 million for removal of biocidal areas and periodic
soil sampling to monitor the alternative effectiveness. ~e Table 10 for cost
comparison.
!
7.8 ALTERNATIVE NO.8 - Low Temperature Thennal Desorption
On-site low temperature thermal desorption is a relatively recent technology which
has gained acceptance as an alterative to incineration. Mobile thermal treatment units
have been shown to remove pesticides and other contaminants from soil similar to
those at QUI of the Marzone Site.
The process consists of a heated chamber with. temperatures of 700 to 900 degrees
Fahrenheit. Approximately 12,000 cubic yards of contaminated soil are excavated
from the Site, broken up, preconditioned, and then fed into the chamber in a
continuous operation. The pesticide contaminants are driven off the soil by the heat
and are captured in the next stage bag house, granular activated carbon (GAC), or
other equivalent system. GAC has been the most effectiye method of capturing the
off-gas from pesticide-contaminated soil. The treated, uncontaminated soil is placed
back at the Site and the GAC is sent off-site to an authorized incinerator for disposal
or for regeneration, if appropriate. '
It is estimated that the total capital cost for the low temperature thermal desorption
alternative, which is also the present net worth, is $4.8 million. These costs include
planning and design fees, as well as mobilization and implementation of the
alternative. See Table 10 for cost comparison.
7.9 ALTERNATIVE NO.9 - Chemical Oxidation
Chemical oxidation is a technology that has its roots in sewage treatment. It has been
adapted for the treatment of pesticide contaminated soil, often using chemicals that
are in ready supply for the sewage treatment industry. The treatment system ,
comprises a batch process and involves mixing the contaminated soil with sodium
hypochlorite and water and stabilizing the mixture with lime. When the batch is
proved, by testing, to be below the required level of contaminants, it is landfilled
The major sequences of this alternative consist of.
1.
Excavation of contaminated soil, with loading and transporting to a
Record of Decision (OUI)
, Marzone, Inc./Chevron Chemical. Company Site
28
-------
2.
perInitted Treatment, Storage, or Disposal (TSD) facility.
Treatment of the contaminated soil at the TSD facility treatment plant in
batches.
200 cubic yards of contaminated soil is placed in a waste holding tank.
Sodium hypochlorite in a liquid mixture with water is introduced into
the tank and is mixed with the soil to start the oxidation process.
Lime is made into a slurry mixture with water in a pugmill and
conveyed to the holding tank.
The lime slurry and soil are mixed in the holding tank until the reaction
is complete.
The treated soil is tested by the toxic characteristic leaching procedure
(TCLP) and transported to an appropriate landfill, contingent on their
Land Disposal Restriction (LOR) status.
The batch process is repeated until all the soil have been treated.
3.
4.
5.
6.
7.
8.
The estimated costs, induding engineering, testing, supervision, and contingency, are
$540 a cubic yard for excavation, chemical oxidation, and landfilling. It is estimated
that one-third of the total soil (4,000 cubic yards) will require treatment. The
remaining soil will be directly landfilled at $160 per ton. Therefore, the capital and
present worth costs would be $4.1 million. There is no annual or maintenance cost.
See Table 10 for cost comparison.
Record of Decision (OUI)
Marzone, Inc./Chevron Otemica1 Company Site
29
-------
8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
This section of the ROD provides the basis for determining which
alternative provides the best balance with respect to the statutory balancing criteria in
Section 121 of CERCLA and in Section 300.430 of the NCP. See Table 13-15 for a list
of potential ARARs and TBCs. The NCP categorizes the nine evaluation criteria into
three groups:
1.
THRESHOLD CRITERIA - overall protection of human health and the
environment and compliance with ARARs (or invoking a waiver) are
threshold criteria to be eligible for selection;
2.
PRIMARY BALANCING CRITERIA - long-term effectiveness and
permanence; reduction of toxicity, mobility, or volume; short-term
effectiveness; implementability, and cost are primary balancing factors
used to weigh major trade-offs among alternative hazardous waste
management strategies; and
3.
MODIFYING CRITERIA - state and community acceptance are
modifying criteria that are formally taken into account after public
comment is received on the proposed plan and incorporated in the
ROD.
The selected alternative must meet the threshold criteria' and comply with all ARARs
or be granted a waiver for compliance with ARARs. Any alternative that does not
satisfy both of these requirements is not eligible for selection. The Primary Balancing
Criteria are the technical criteria upon which the detailed analysis is primarily based.
The final two criteria known as Modifying Criteria, assesses the public's and the state
agency's acceptance of the criteria. EPA may modify aspects of a specific alternative
based upon this criteria.
The following analysis is a summary of the evaluation of alternatives for remediating
aUl of the Marzone, Inc./Chevron Chemical Site under each of the criteria. A
comparison is made between each of the alternatives for achievement of a specific
criterion.
Record of Decision (OUI)
Marzone, Inc./CJtevron CJtemical Company Site
30
-------
TABLE 9: COMPARISON OF THRESHOLD AND BALANCING CRITERIA
I Alternate No. ~
Overall Protection of Human N Y Y N Y Y Y Y Y
Health and the Environment
Compliance With ARARs N N Y N N Y Y Y Y
Long-Term Effectiven~ss and N N Y N N N Y Y N
Permanence
Reduction in Toxicity, Mobility, and N N Y N N Y Y Y Y
Volume Through Treatment
Short-Term Effectiveness N N N N N Y N Y Y
Implementability Y Y Y Y Y Y Y Y Y
Cost Effectiveness Y Y Y Y Y Y Y Y Y
THRESHOLD CRITERIA
GROUNDWATER
,
8.1 Overall Protection of Human Health and the Envirortment
T4e no action alternative does not provide adequate protection of human health or
the environment if the groundwater were to be used as drinking water in the future.
The institutional controls alternative provides protection by restricting future use.
Only the pump and treat option provides adequate protection, and would use active
measures to reduce contamination and reduce the future threat to human health and
the environment and more quickly remediate to cleanup levels.
8.2 Compliance with ARARs
Key ARARs:
40 CPR Part 141, National Primary Drinking Water Regulations
40 CPR Part 143, National Secondary Drinking Water Regulations.
Georgia Drinking Water Regulations, Chapter 391-3-5.
GaEPD has classified the surficial aquifer as a potential drinking water source. Based
upon this the no action and institutional controls alternatives do not meet the Federal
and state ARARs for drinking water standards.. These standards are MCLs , non-zero
MCL goals, or risk-based concentrations safe for drinking water. The pump and treat
Record of Decision (OUI)
Marzone, Inc./Clevron Clemica1 Company Site
31
-------
I
alternative is the only alternative that will meet these standards.
PRIMARY BALANONG CRITERIA
8.3 Long-Term Effectiveness and Permanence
Unsaturated and saturated zone models were used to estimate how long it would
take to reach risk-based concentrations or MCLs at the point of compliance if the no
action or institutional alternatives were selected. The results indicate that it would
take much longer than 30 years for a-BHC, ~BHC, lindane, methyl parathion, xylene,
ethylbenzene, toxaphene, DDT, and atrazine to reach their cleanup levels in
groundwater. Alternative 3 will meet cleanup levels by providing a capture zone that
will reduce migration of contaminants, extract and treat contaminated groundwater
and be enhanced by natural attenuation; resulting in less than 30 year timeframe to
meet cleanup levels.
8.4 Reduction in Toxicity, Mobility, and Volume Through Treatment
The no action and institutional controls alternatives would not provide for a
reduction in toxicity, mobility and volume through treatment since they are not
treatment options. Only the pump and treat alternative would provide reduction in
toxicity, mobility, and volume of contaminated groundwater to cleanup levels
through treatment.
8.5 Short-Term Effectiveness
All systems would be ineffective in meeting cleanup lev~ls in the near future. The no
action and institutional control alternatives would have ,the least immediate harmful
effect on human health or the environment, but they would also provide less
protection in the short term. The pump and treat alternative would slightly increase
the risk of exposure by pumping and handling of contaminated groundwater. Those
risks would be reduced to safe levels by using proper safety measures.
8.6 Implementability
The no action alternative is the easiest to implement because there is little to
implement. Imposing institutional controls will require legal actions. The
groundwater pump and treat system will require adjustments, maintenance,
sampling, and periodic replacement. The groundwater pump and treat system will
require testing to determine the best design to remediate the groundwater.
8.7 Cost Effectiveness
The groundwater pump and treat system costs more than both the no action and
institutional controls alternatives (Table 10), but is the only groundwater remedy that
meets the threshold criteria for protection for protection of human health and the
enyironment and compliance with ARARs. Therefore the higher cost is justifiable and
cost effective.
Record of Decision (OUt)
Marzone, Inc./Ctevron Ctemical Company Site
32
-------
MODIFYING CRITERIA
8.8 State Acceptance
EP A has consulted with the Georgia Environmental Protection Division (GaEPD) and
received a letter dated September 30, 1994, indicating State conCWTence on the
remedy selection in this ROD, but deferring concurrence on the performance
standards in light of the newly promulgated rules of the Georgia Hazardous Site
Response Act. The letter is attached as Appendix B of this ROD.
8.9 Community Acceptance
EP A has determined community acceptance of the preferred alternative after
considering comments received during the public comment process associated with
the Proposed Plan. A Responsiveness Summary has been included as an attachment
to this Record of Decision (ROD) in Appendix A explaining how the comments were
addressed.
SOIL
THRESHOLD CRITERIA
8.10 Overall Protection of Human Health and the Environment
Contamination which could pose a threat to human health and the environment is
present in the surface and subsurface soil at QU1 of the Site. Surface soil pose a risk
from direct exposure. Subsurface soil pose a risk to the groundwater. The no action
alternative does not provide adequate protection from ~ese risks. The institutional
controls alternative limits direct exposure risk by limiting access and land use but
dO,es not remediate the soil. The chemical oxidation landfill disposal, bioremediation
and thermal desorption alternatives provide adequate protection through
remediation. The chemical oxidation, landfill disposal and thermal desorption
alternatives meet a lx1 risk cleanup level for surface soil, while bioremediation
provides a lx10-5 risk level for surface soil.
8.11 Compliance with ARARs
Key ARARs:
40 CPR Part 261, Identification and listing of Hazardous Waste.
40 CPR Part 264, Standards for Owners and Operators of Hazardous Waste
Treatment, Storage, and Disposal Facilities.
40 CPR Part 268, Land Disposal Restrictions.
The landfilling, low temperature thermal desorption, chemical oxidation, and
bioremediation alternatives will comply with the ARARs for soil, but the no action
arid institutional controls alternatives will not. The biofarming alternative will reduce
the chemical concentrations to a lxlO -5 risk level in about 5 to 7 years. The
excavation and disposal, and chemical oxidation alternatives will meet a 1x1 level
Record of Decision (OUI)
Marzone, Inc./Chevron Otemical Company Site
33
-------
for surface soil remediation within the shortest time period (within 4 to 6 months).
Thermal desorption will take about 1 year.
PRIMARY BALANONG CRITERIA
8.12 Long-Term Effectiveness and Permanence
Landfilling, thermal desorption, and chemical oxidation reduce the residual risk to
lx1£r for residential property use and will reduce levels to eliminate leaching to
groundwater. Bioremediation achieves a 1x10-s risk level for industrial use. Thermal
desorption and bioremediation are the only alternatives presented that lead to a
permanent solution at the Site.
8.13 Reduction in Toxicity, Mobility, and Volume Through Treatment
The bioremediation and low temperature thermal desorption alternatives will reduce
the toxicity, mobility, and volume by on-site treabnent. The excavation and landfill
disposal alternatives do not provide treatment of soil. Chemical oxidation is a
treatment option that will reduce the toxicity and mobility of chemicals in
approximately one-third of the soil but not down to the cleanup levels. The no action
and institutional controls alternatives do not reduce toxicity and volume and are not
treatment technologies.
8.14 Short-Term Effectiveness
The no action and institutional controls alternatives do ~ot provide short-term
effectiveness. Of the four action alternatives, the excavation, chemical oxidation, and
disposal process is a 4 to 6 month operation after beginning on-site remediation
work, and threat to workers and the community can be readily. controlled by using
appropriate construction techniques. The thermal desorption alternative takes over 1
year after mobilization, p"ermitting, and start-up, and the protection of workers and
the community is a slightly greater risk. Biofarming will require 5 to 7 years to
achieve cleanup levels and will require dust and run-off controls.
8.15 Implementability
The no action alternative is easily implemented since no action is necessary. The
institutional controls, excavation and disposal, and chemical oxidation alternatives are
more difficult but still somewhat easy to implement. The latter two use standard
equipment and well proven technology. Institutional controls will require some
administrative and legal actions. Low temperature thermal desorption and
bioremediation are potentially more difficult to implement because they are more
sensitive technologies and are subject to of the variation in the soil quality.
8.16 Cost Effectiveness
The action remedies for soil are more costly than both the no action and institutional
controls, but they meet the threshold criteria, while no action and institutional
Record of Decision (OUl)
Marzone, Inc./Qevron Qemical Company Site
34
-------
controls do not. Bioremediation is less costly than excavation and landfill disposal,
low temperature desorption, and chemical oxidation; thus making it cost effective.
Bioremediation is also a treatment technology and will attain a permanent remedy.
Low temperature thermal desorption is the most expensive remedy but is a proven
technology that will result in a permanent remedy and therefore is cost effective.
MODIFYING CRITERIA
8.17 State Acceptance
EP A has consulted with the Georgia Environmental Protection Division (GaEPD) and
received a letter dated September 30, 1994, indicating State concurrence on the
remedy selection in this ROD, but deferring concurrence on the performance
standards in light of the newly promulgated rules of the Georgia Hazardous Site
Response Act. The letter is attached as Appendix B of this ROD.
8.18 Community Acceptance
After considering comments received during the public comment process associated
with the Proposed Plan, EP A has refined the soil remedy to low temperature thermal
desorption. The community did not prefer EP A's proposed bioremediation remedy
for soil cleanup. In general, the commentors felt the bioremediation remedy was too
experimental, would not remediate the soil, and they preferred a remedy that was
known to effectively treat the contaminated contamination. They also preferred a
remedy that would be implemented in a relatively short time frame and one that
would expose the community to the least risk. During the public meeting the
impression was that the commentors preferred the cont:ihgent remedy of low
temperature thermal desorption over bioremediation. A Responsiveness Summary
has been included as an attachment to this Record of Decision (ROD) in Appendix A
explaining how public comments were addressed.
Record of Decision (OUI)
Marzone, Inc./Otevron Otemical Company Site
35
-------
TABLE 10: COST ANALYSIS OF ALTERNATIVES
Action Cost, $
No.
1 No Action for Groundwater Cap-itol = 0
O&M = 37,500
PW = 425,000
2 Institutional Controls for Cap-itol = 37,000
Groundwater O&M = 65,000
PW = 775,000
3 Groundwater Extraction Ca~tol = 540,000
I 0 = 285,500
PW = 3,400,000
4 No Action for Soil Ca~tol = 0
o = 37,500
PW = 425,000
5 Institutional Control for Soil Ca~tol = 73,000
o = 52,500
PW = 675,000
6 Excavation and Landfill Disposal Cap-itol = 3,000,000
O&M = 0
PW = 3,000,000
7 Bioremediation Ca~tol = 2,000,000
o =700,000
PW = 2,700,000
8 Low Temperature Thennal CaRitol ~ 4,800,000
Desorption O&M = .0
PW = 4;800,000
9 Chemical Oxidation CaRitol= 4,100,000
.O&M = 0
PW = 4,100,000
Record of Decision (OUn
Marzone, Inc./CJtevron OIemica1 Company Site
36
-------
9.0 SUMMARY OF SELECTED REMEDY
Based upon the requirements of CERCLA, the NCP, EP A Policy, and the detailed
analysis of alternatives presented in the Feasibility Study, EP A has selected a remedy
for Operable Unit 1 at the Marzone Site. The remedy addresses remediation of
contaminated groundwater and soil.
9.1 Groundwater Remedy
For the contaminated groundwater on-site, the selected remedy is Groundwater
Pump and Treat with enhancement through use of an infiltration gallery. This
remedy will consist of extracting the contaminated groundwater from the surficial
aquifer, treating it on-site through a carbon fIltration system and passing it back into
the aquifer through an infiltration gallery. The used carbon filters will be taken
off-site for recharge and reuse. It is anticipated that approximately 2 groundwater
recovery wells will be installed in the area of the loading dock with possibly about
another two installed within the contaminated aquifer near the area of the rinsate
pond. The number of wells and their specific location will be optimized to extract all
contaminants of concern for treatment down to the performance standard. Location,
sizing, and pumping rates for wells will be determined by evaluating the results of a
pumping test that will be conducted as part of the remedial design phase.
Contaminated groundwater will be pumped to the water treatment system, treated,
and passed through an infiltration gallery. Since the underlying aquifer is relatively
slow moving, an infiltration gallery will be utilized to help enhance movement of
contaminated groundwater toward the extraction wells. Pumping and treating the
groundwater will continue until the performance standards on Table 11 of this ROD
are achieved this is estimated to take 7-41 years to cleanup the contaminated
groundwater at OUI.
This remedy also includes fencing to prevent Site access to the public, and periodic
groundwater monitoring to track changes in the level and extent of contamination.
The major components consist of:
. The implementation of institutional controls.
. The implementation of a pumping test, to aid in determining specific
design criteria for the extraction and monitoring system.
The design and construction of groundwater extraction and monitoring
wells.
The installation of a security fence around the on-site treatment unit.
The design and installation of a groundwater pumping and monitoring
system, a groundwater fIltration system, a treatment system, and an
infiltration gallery.
The start-up and operation of this system.
The transportation, regeneration, recycling, and/or disposal of the spent
filters.
The operation and maintenance of a long-term groundwater monitoring
.
.
.
.
.
.
Record of Decision (OUI)
Marrone, Inc./Chevron Chemical Company Site
37
-------
program. Includes quarterly monitoring of parameters in extraction
wells and specified monitoring wells.
The groundwater remedy for Operable Unit #1 of the Marzone Site is consistent with
the requirements of Section 121 of CERCLA and the National Contingency Plan. The
remedy will reduce the mobility, toxicity, and volume of contaminated groundwater
at the Site. In addition, the remedy is protective of human health and the
environment, will attain all Federal and State applicable or relevant and appropriate
requirements, is cost-effective, and utilizes permanent solutions to the maximum
extent practicable. The remedy for OUI is consistent with previous and projected
remedial actions at the Site. Based on the information available at this time, the
selected remedy represents the best balance among the criteria used to evaluate
remedies.
9.1.1 Performance Standards for Groundwater
Groundwater shall be extracted from the surficial aquifer at a rate to be determined
through the results of an EP A established or approved pumping test and shall be
treated until the following performance standards set out in Table 11 are achieved at
wells that were located and/or designated by EPA in the RD phase.
TABLE 11: PERFORMANCE STANDARDS FOR GROUNDWATER
Constituent Concentration (ppm)
a-BRC 0.00003
~-BHC 0.0001
DDD 0.00077
DDT 0.00054
Ethylbenzene 0.7
Lindane 0.0002
Methyl Parathion 0.0039
Xylene 10.0
9.1.2 Infiltration Standards
Treated groundwater that will be passed through the infiltration gallery shall comply
with all ARARs and TBCs. GaEPD's classification of this aquifer as a potential
drinking water source yields a requirement for all groundwater ~t passes through
the infiltration gallery to meet MCLs or the risk-based cleanup levels for those
chemicals without MCLs. Periodic sampling of such groundwater is required prior to .
Record of Decision (OUl)
Marzone, Inc./Chevron Otemical Company Site
38
-------
passage through the infiltration gallery to verify that the groundwater infiltration
standards are being met. A schedule of compliance appropriate for the purpose of
this monitoring shall be included as part of the remedial design phase. All treated
water that will be passed through the infiltration gallery must meet the performance
standards set out in Table 11.
9.1.3 Design Criteria for Groundwater
The design, construction, and operation of the groundwater treatment system shall be
conducted in accordance with all ARARs, including but not limited to the RCRA
requirements set forth in 40 C.F.R. Part 264 (Subpart F). All design specifications will
be developed through the remedial design process so as to achieve the performance
standards set out in Table 11.
9.1.4 Compliance Monitoring for Groundwater
Groundwater monitoring shall be conducted at this Site. After demonstration of
compliance with the performance standards set out above, the Site groundwater shall
be monitored for no less than five years. If monitoring indicates that the performance
standards set forth in Table 11 are being exceeded at any time after pumping has
been discontinued, extraction and treatment of the groundwater will recommence
until the performance standards are once again achieved and compliance monitoring
thereafter re-established. At that time, the effectiveness of the source control
component may be re-evaluated by EP A. A schedule of compliance for a
groundwater monitoring plan that verifies compliance with the performance
standards shall be included as part of the remedial design phase.
9.1.5 Cost
CCWitol cost for the groundwater remedy is $540,000 which includes emplacement of
inStitutional controls, installation of extraction wells, treatment plant, and the
infiltration gallery with an O&M of $285,500 for monitoring continued operation. The
estimated present worth of the remedy is $3.4 million.
9.2 Soil Remedy
For the soil medium, the selected remedy is Low Temperature Thermal Desorption.
This remedy includes the utilization of a mobile thermal treatment unit to remove
Site contaminants from soil at OUI of the Marzone Site.
The remedy will entail the use of a mobile low temperature thermal desorption unit
that consists of a heated chamber with temperatures of 700 to 900 degrees Fahrenheit.
Approximately 12,000 cubic yards of surface and subsurface contaminated soil will be
excavated from the Site, broken up, preconditioned, and then fed into the chamber in
a continuous operation. The thermal desorption unit will drive off pesticide
contaminants from the soil that will be captured in the next stage bag house, GAC, or
other equivalent system. Both surface and subsurface soil will be treated to the
Record of Decision (OUl)
Marzone, Inc./O\evron Olemical Company Site
39
-------
. ---
performance standards set out on Table 12 of this ROD. The treated, decontaminated
soil, will be placed back at the Site. In order to facilitate this remedy expediously
and effectively, OUI of the Marzone Site is designated as a Corrective Action
Management Unit (CAMU) and an Area of Contamination (AOC) for purposes of this
ROD. All waste managed within the CAMU/ AOC must comply with the
requirements set out in this ROD for soil remediation. OUl, and the designated
CAMU/ AOC, consists of the contamination on the 1.68-acre former Marzone
pesticide formulating area, part of the Slack property, railroad drainage ditch area
past the southwest comer of the horse pasture, contaminated groundwater related to
the Site (see Figure 2) and all suitable areas in close proximity to the contamination
necessary for implementation of the remedy selected in this ROD. Since soil
contamination at OUI Will be cleaned down to the risk-based performance standards,
no closure standards apply for this CAMU / AOC.
Major components of the soil remedy include:
. The excavation of all soil contamination at OUI above the performance
standards.
The staging and preconditioning of soil for entry into the thermal
desorption unit.
The feeding of contaminated soil into the heated chamber for treatment.
The processing of contaminated soil through the thermal desorption unit
including the bag house, GAC, or other equivalent system.
The placement of treated, decontaminated soil back to the Site.
The periodic soil sampling during treatment to verify effectiveness of
the remedy. .'
Air monitoring to ensure safety of nearby residents and workers.
Demobilization and removal of the thermal desorption unit after
completion of the remedy.
The soil remedy for Operable Unit #1 of the Marzone Site is consistent with the
requirements of Section 121 of CERCLA and the National Contingency Plan. The
remedy will reduce the mobility, toxicity, and volume of contaminated soil at the
Site. In addition, the remedy is protective of human health and the environment, will
attain all Federal and State applicable or relevant and appropriate requirements, is
cost-effective, and utilizes permanent solutions to the maximum extent practicable.
The remedy for OUI is consistent with previous and projected remedial actions at the
Site. Based on the information available at this time, the selected alternative
represent the best balance among the criteria used to evaluate remedies.
.
.
.
.
.
.
.
9.2.1 Performance Standards for Soil
For the low temperature thermal desorption remedy, the performance standards for
surficial soil.~."ased upon a lxl()"6 risk level for a cleanup associated with future
residential land use. For subsurface soil the cleanup level was calculated using the
MUL TIMED groundwater model Performance standards are set out in Table 12.
Record of Decision (OUl)
Marzone. Inc./Otevron Otemical Company Site
40
-------
Excavation of soils within the confines of OUI and which are contaminated above the
performance standard shall continue until the remaining soil achieves the
performance standards set out in Table 12. All e"xcavation shall comply with ARARs,
OSHA, and state standards. Pertinent testing methods will be selected or approved
by EP A and used to determine whether the performance standards have been
achieved.
All excavated soil shall be treated by means of a mobile low temperatW'e thermal
desorption unit to the performance standards set out in Table 12. All treatment shall
comply with ARARs, OSHA, and state standards. Treated soil will be used to
backfill the Site if it achieves the performance standards, otherwise it will be again
treated by the thermal desorption unit until performance standards are achieved.
TABLE 12: PERFORMANCE STANDARDS FOR SOIL
SURFACE SOILb SUBSURFACE
(ppm> SOIL C
CONSTITUENT HI=l, lxla' (ppm>
Atrazine 3.5 0.150
a-BHC 0.12 1.142
j3-BHC 0.547
DDD 3.2
DOE 2.28 ,
DOT 2.29
Dieldrin 0.049
EndosuIfan IT 2.6
Ethylbenzene 573
Heptachlor 0.085
Epoxide
Lindane 0.463
Methyl Parathion 4.55
Toxaphene 0.7
Xylene 213
.
Blank spaces indicate no cleanup lewl set because the chemical is not a COC for the medium.
Surface soil cleanup levels are based on future residential land use. Cleanup levels are based on a cancer risk of 1
x lUC , or a hazard index of 1.0. Surface soil refers to the top foot of soil.
Subsurface soil cleanup levels were calculated using the MULTIMED model
b
Record of Decision (OUl)
Marzone, Inc./Chevron Chemical Company Site
41
-------
9.2.2 Design Criteria for Soil
The design, construction, and operation of the low temperature thermal desorption
system shall be conducted in accordance with all ARARs, including but not limited to
the RCRA requirements set forth in 40 C.F.R. Part 264 (Subpart F). The thermal
desorption unit shall consist of a heated chamber, a bag house, GAC, afterburner, or
equivalent system. All design specifications will be developed through the remedial .
design process to meet the performance standards set out in Table 12.
9.2.3 Soil Testing
Soil testing shall be conducted on Site to determine the effectiveness of meeting the
soil performance standards set out in Table 12. Performance will be met when the
confirmatory sampling effort shows all samples have been remediated to a level at or
below the performance standard. ConfIrmatory sampling will include testing of both
the decontaminated soil exiting the thermal desorption unit and any soil left in place.
All such soil shall meet the performance standard.
9.2.4 Cost
For low temperature thermal desorption, it is estimated that the cost and present
. worth of the remedy is $4.8 million. These costs include planning and design fees, as
well as mobilization and implementation. The capital cost is $4.8 million; there are
no O&M costs associated with this remedy.
The total cost of the groundwater and soil remedy for OJ.J1 of the Marzone Site is
$8.2 million. This includes groundwater pump and treat and soil remediation
. through low temperature thermal desorption.
Record of Decision (OUt) ..
Marzone. Inc./Chevron Otemica1 Company Site
42
-------
10.0 STATUTORY DETERMINATIONS
Under its legal authorities, EPA's primary responsibility at Superfund sites is to
undertake remedial actions that achieve adequate protection of human health and the
environment. In addition, Section 121 of CERCLA establishes several other statutory
requirements and preferences. These specify that, when complete, the selected
remedial action for this Site must comply with applicable or relevant and appropriate
environmental standards as established under Federal and State environmental laws
unless a statutory waiver is justified. The selected remedy also must be cost effective
and utilize permanent solutions and alternative treatment technologies or resource
recovery technologies to the maximum extent practicable. Finally, the statute includes
a preference for remedies that employ treatment that permanently and significantly
reduce the volume, toxicity, or mobility of hazardous wastes as their principal
element. The following sections discuss how the selected remedy meets these
statutory requirements.
10.1 Protection Of Human Health And The Environment
The selected remedy protects human health and the environment through isolating
and treating threats at Operable Unit #1 of the Site in contaminated groundwater and
soil. The selected remedy provides protection of human health and the environment
by eliminating, reducing, and controlUng risk through treatment, engineering and/or
institutional controls. The contaminated groundwater underlying OUI of the Marzone
Site will be pumped and treated to cleanup levels. In addition institutional controls
will be employed throughout the treatment process to protect human heath and the
environment. Contaminated soil will be treated through low temperature thermal
desorption. For surface soil the cleanup level will meet a 1Xlcr risk-based level. The
subsurface soil will be cleaned up to levels that are protective of groundwater.
10.2 Compliance With ARARs
Remedial actions performed under CERCLA must comply with all applicable or
relevant and appropriate requirements (ARARs). All alternatives considered for OUI
of the Marzone Site were evaluated on the basis of the degree to which they
complied with these requirements. The selected remedy was found to meet or exceed
the following ARARs.
Record of Decision (OUI)
Marzone, Inc./O\evron O\emical Company Site
43
-------
TABLE 13: FEDERAL ARARs FOR MARZONE SITE OUI
I CLEAN WATER ACT - 33 U.S.c. ~ 1251-1376 I
OTATIONS COMMENTS
R&A 40 CFR Part 131 Chemical Specific Provides for the establishment of
Ambient Water Quality Criteria for ground water water quality based on toxicity to
Requirements aquatic organisms and human health.
40 CFR Part 141 ! Chemical Specific Establishes primary drinking water
R&A National Primary Drinking Water for ground water r~ations pursuant to Sedion 1412
Regulations 0 the Public Health Service Act, as
amended ~ the Safe Drinking Water
Act; an~ ted regulations applicable
to pubhc water systems.
R&A 40 CFR Part 142 Chemical Specific Sets forth Sections 1413-1416, 1445,
National Pri~ Drinking Water for groundwater and 1450 of the Public Health Service
Regulations Imp ementation Act, as amended.
R&A 40 CFR Part 143 Chemical Specific Establishes National Secondary
National Secondary Drinking Water for groundwater Drinking Water ~Iations Rursuant
Regulations to Section 1412 of Safe Drinking
Water Act, as amended (42 US.c.
; ~ and control contaminants in
'dri . ~ water that primarily affect
the aest etic qualities relating to the
public acceptance of drinking water.
A 40 CPR Part 144 Action Specific for Set forth requirements for the
Underground Injection Control groundwater Underground :on Control (UIC)
Rr~ ~~ted under Part C of
the e . . g Water Act.
Record of Decision (OUl)
Marzone, Inc./Otevron Otemical Company Site
44
-------
II TABLE 13: FEDERAL ARARs FOR MARZONE SITE OUI I
RESOURCE CONSERV AllON AND RECOVERY ACT - 42 U.S.C. ~~ 6901-6987
CITATIONS COMMENTS
A 40 aR Part 261 Action Specific for Identifies those solid wastes which are
Identification and Listing of Soil subject to ~tion as hazardous
Hazardous Waste wastes. Defiiies the tenn "solid waste"
and "hazardous waste".
I
R&A 40 aR Part 262 Action Specific for Establishes standards for generators of
Standards Ap~cable to Generators Soil hazardous waste.
of Hazardous aste
A 40 aR Part 263 Action Specific for Establishes the responsibilities of
Standards Applicable to Soil ctors and tr~rters of
Transporters of Hazardous Waste ous waste in handlinf
~rtation, and managemen of
that waste.
R&A 40 aR Part 264 Action Specific for Establishes minimum national
Standards for Owners and Soil standards which define the acceptable
Qperators of Hazardous Waste management of hazardous waste for
Treatment, Storage, and Disposal owners and 0I::ators of facilities
(TSD) Facilities. which treat, s re, or dispose of
hazardous waste.
R&A 40 CFR Part 268 Chemical Specific Identifies hazardous wastes that are
Land Disposal Restrictions for Soil restricted from land dis~ gnd
describes those circums ces under
which an otherwise P.TOhibited waste
may be land disposea.
A Federal R~ster/VOI. 58 Action Specific for Finalizes provisions for corrective
Febru~ 1 , 1993 soil and action mana~t units (CAMUs)
40 CFR art 260 et a1 groundwater and te~~~ units under Subpart S
Corrective Action Mana~nt of 40 Part 264. Defines the teIm
Units and TempoI!IY nits; "remediation waste".
Corrective Action PrOvisions; Fmal
Rule
R&A 40 CPR Part 270 Action Specific for Establishes Rrrovisions for the
EP A Administered Permit Soil Hazardous aste Permit Pro~
Progta!I\S: under Subtitle C of the Solid aste
Hazardous Waste Permit Program Disposal Act.
A- APPUCABLE REQUIREMEN1S WHIOi WERE PROMULGATED UNDER FEDERAL LAW TO SPE
-------
I TABLE 14: STATE ARARs FOR MARZONE SITE OUI I
I I OTATIONS I I COMMENTS I
A Georgia Drinking Water Regulations, Chemical and Establishes rules and regulations
Chapter 391-3-5 Location :c for Geota drinking water
for groun water standar s and addresses wellhead
protection zones.
A Rules of the Geor~a Department of Action Specific Provides rules for the
Natural Resources Environmental for Soil Underground Storage Tank
Protection Division, Chapter 391-3-15 ProgTCi!l\- GaEPD his not set soil
action levels for contaminants
other than petroleum
hydrocarbOns.
A ~ Water Quali~ Control Action and Establishes Georgia surface water
Rations and Stan ards Chemical quality aiteria.
S~c for
runoff
A -APPUCABLE REQUIREMENTS WHICH WERE PROMULGATED UNDER FEDERAL tAW TO SPECIFICALLY ADDRESS A HAZARDOUS SUBSTANCE.
POLLUTANT. CONTAMINANT, REMEDIAL ACTIONt.OCA.TION OR OTHER CRCUMSTANCE AT OUI OFlHE MARroNE SITE.
R & A --RElEVANT AND APPROPRIATE REQUIREMENTS WHICH WHILE THEY ARE NOT .APPUCABlE" TO A HAZARDOUS SUBSTANCE. POLLUTANT.
CONTAMINANT. REMEDIAL ACTION. t.OCA.TION. OR OTHER CRCUMSTANCE AT OUi OF tHE MARroNE SITE. ADDRESS PROBLEMS OR SITUATIONS
SUFFlaENTtY SIMILAR TO tHOSE ENCOUNtERED AT OUi OF tHE MARZONE SITE THAT THEIR USE IS WELL SUITED TO tHE SITE.
TABLE 15: To-BE-CONSIDERED (TBCs) DOCUMENTS FOR MARZONE SITE OUI
I DOCUMENT TYPE I DESCRIPTION I
USEPA, Office of Drinking Water, Drinkin9 Water Issues health advisories based on exposure to various
Reaulations and Health Advisories wasfiangtoi\,"'" concentrations of chemicals of concern.
D.C., December 1993
TBCs - TO-BE-CONSJDERED CRITERIA ARE NON-PROMULGATED ADVISORIES AND GUIDANCE mAT ARE NOT LEGALLY
BINDING, BUT SHOULD BE CONSIDERED IN DEI'ERMINING TIlE NECESSARY LEVEL OF CLEANUP FOR PROTECI1ON OF
HEAL1H OR'IHE ENVIRONMENT.
Record of Decision (OUI)
Marzone, Inc./Olevron OIemical Company Site
46
~
-------
10.3 Cost Effectiveness
Cost effectiveness is determined by comparing the cost of all alternatives being
considered with their overall effectiveness to determine whether the costs are
proportional to the effectiveness achieved. EP A evaluates the incr~mental cost of each
alternative as compared to the increased effectiveness of the remedy. The selected
remedy for groundwater is pump and treat. This remedy is more costly than both the
no action and institutional controls alternatives but is the only groundwater remedy
that meets the threshold criteria for protection of human health and the environment
and compliance with ARARs. Therefore, the higher cost is justified and cost effective.
The selected remedy for soil is low temperature thermal desorption. This alternative
is more costly than botl,1 the no action and institutional controls alternatives but meets
the threshold criteria, while no action and institutional controls do not. The low
temperature thermal desorption remedy is also more costly than excavation and
landfill disposal, bioremediation, and chemical oxidation. Low temperature thermal
desorption along with bioremediation are the only two remedies that involve
treatment to achieve a permanent remedy for the Site. Bioremediation will only
achieve a cleanup standard based upon a lxHrs risk which is not appropriate for
future residential land use. Low temperature thermal desorption is the only remedy
that fulfllls the threshold criteria, is a permanent remedy, and will remediate to a risk
based level of 1x1cr for future residential land use, therefore, making it a reasonable
value.
10.4 Utilization Of Permanent Solutions To The Maximum Extent Practicable
EP A and GaEPD believe that the selected remedy is the ~ost appropriate cleanup
solution for aU1 of the Marzone Site and provides the best balance among the
evaluation criteria for the remedial alternatives considered. The pump and treat
remedy for groundwater is a permanent remedy. The low temperature thermal
desorption remedy is also a permanent remedy. In all cases treated media can be
returned to the Site. The selected remedy meets the statutory requirement to utilize
permanent solutions and treatment technologies to the maximum extent practicable.
10.5 Preference For Treatment As A Principal Element
The statutory preference for treatment will be met through treatment of contaminated
groundwater and through the low temperature thermal desorption treatment remedy
for the soil.
Record of Decision (OUI)
Marzone, Inc./Otevron Otemical Company Site
47
-------
.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The final remedy for OUI of the Marzone Site was refined somewhat from the
proposed plan fact sheet, in that, the remedy for soil remediation will be low
temperature thermal desorption. The proposed plan presented a remedy for soil of
bioremediation by landfarming/composting with a contingency for low temperature
thermal desorption. The biofarming alternative was proposed because EP A believed
that the community would be more receptive of a bioremediation (e.g peanut
farming) remedy over low temperature thermal desorption. Biofarming would be
consistent with the agricultural land use in the Tuton, GA area. EP A weighed
heavily its criteria for community acceptance when proposing the biofarming
alternative.
I
It was evident from the comments received, both verbally and in writing, that the
biofarming alternative was not the communities preferred remedy. The community
expressed concern over the success of the highly innovative technology and over the
longer time frame for bioremediation. There were also some concerns over the
degree of remediation (lxU)"s versus lxlcr> from the biofarming alternative. Based
upon these factors, EPA reevaluated the 9 criteria for remedy selection and determine
that the low temperature thermal desorption remedy was, in fact, the best remedy for
remediating the soil at OUI of the Marzone Site. Low temperature thermal
desorption is a proven technology that results in a permanent remedy for OUI. The
time frame for remediation is approximately 1 year and it will remediate surface soil
to a lxl0-6 risk based level for a future residential land use.
Record of Decision (OUI)
Marzone, Inc./O\evron O\emica1 Company Site
48
-------
RECORD OF DEOSION
APPENDIX A
RESPONSIVENESS SUMMARY
Marzone, Inc./Chevron Chemical Company Site
Tift County, Georgia
Record of Decision (OUI)
Marzone, Inc./O\evron Ctemical Company Site
-------
Responsiveness Summary
Marzone, Inc./Chevron Chemical Company Site
Tift County, Georgia
The U.S. Environmental Protection Agency (EP A) held a public comment period from
July 15, 1994 through August 15, 1994 for interested parties to give input on EPA's
Proposed Plan for Remedial Action at Operable Unit 1 (OUl) of the Marzone
Inc./Chevron Chemical Company Superfund Site in Tifton, Tift County, Georgia.
EPA conducted a public meeting on July 26, 1994, at the Neighborhood Services
Center in Tifton, Georgia. The meeting presented the results of the Remedial
Investigation and Feasibility Study (RI/FS) for OUI of the Marzone Inc./Chevron
Chemical Company Site and the Proposed Plan of action for remediation. Thepublic
comment period was extended an additional 30 days, Le., until September 14, 1994
after EP A received two requests for an extension.
A responsiveness summary is required to document how EP A addressed citizen
comments and concerns about the Site, as raised during the public comment period.
All comments summarized in this document have been factored into the final
decision of the remedial action for OUI of the Marzone Inc./Chevron Chemical Site.
This responsiveness summary for the Marzone Inc./Chevron Chemical Company Site
is divided into the following sections. .
I.
Overview - This section discusses the recommended alternative for
remedial action and the public reaction to'tlus alternative.
II.
Background on Community Involvement and Concerns: This section
provides a brief history of community interest and concerns regarding
the Marzone Site.
III.
Summary of Major Questions anq Comments ~uring thg
Public Comment Period and EP A' s Responses: This section presents
comments submitted during the public comment period and provides
the responses to these comments.
IV.
Concerns to be Addressed in the Future: This section discusses
community concerns of which EP A should be aware during remedial
design.
A-I
-------
I.
Overview
The remedial alternatives were presented to the public in a Proposed Plan released
on July 14, 1994, and in a public notice in the Tifton Gazette on July 11, and July 18,
1994. A public meeting was held July 26, 1994 with over 200 people attending.
EP A has organized the work at this Site into two phases or operable units (OUs).
OUI involves contamination on the l.68-acre former Marzone pesticide blending area,
part of the Slack Property, and railroad drainage ditch past the southwest comer of
the horse pasture, and contaminated groundwater related to the Site. This first
operable unit is broken down into two separate remedies; one for groundwater and
the other for soil. I
For contaminated groundwater, the selected remedy is Alternative No.3,
Groundwater Pump and Treat and reinjection through an infIltration gallery.
The major components of th~ selected remedy include:
.. The implementation of institutional controls.
.. The design and construction of groundwater extraction wells.
.. The installation of a security fence around the on-site treatment unit.
.. The design and installation of a groundwater pumping system, a
groundwater fIltration system, a on-site treatment system, and an
infiltration gallery.
The start-up and operation of this system!
Transportation, regeneration, recycling, and disposal of the spent filters.
Operation of a long-term groundwater monitoring program. Which will
include periodic monitoring of parameters in extraction wells and
specific monitoring wells. .
..
..
..
The cost of this alternative would be $3.4 million.
For soil contamination, the preferred alternative as presented to the public in the
proposed plan fact sheet was NO.7, Bioremediation by landfarming/ compo sting
with a contingency remedy of alternative NO.8, Low Temperature Thermal
Desorption.
The final selected remedy for the soil at OUI of the Marzone Site is NO.8, Low
Temperature Thermal Desorption. This remedy will include the use of a mobile
thermal treatment units to remove Site contaminants from OUI soil at the Marzone
Site. The low temperature thermal desorption unit will consist of a heated chamber
with temperatures of 700 to 900 degrees Fahrenheit. Approximately 12,000 cubic
yards of contaminated soils will be excavated from the Site, broken up,
preconditioned, and then fed into the chamber in a continuous operation. The
thermal desorption unit will drive off pesticide contaminants from the soil that will
A-2
-------
be captured in the next stage bag house, GAC, or other equivalent system. Both
surface and subsurface soils will be treated to the performance standards set out in
this ROD. The treated, decontaminated soil, will be placed back at the Site. The
estimated cost of this remedy is $4.8 million.
The total estimated cost of the groundwater and soil remedy for OUI of the Marzone
Site is $8.2 million. This includes groundwater pump and treat and soil remediation
through low temperature thermal desorption.
Most of the community's concerns were related to health issues either from exposure
to the Marzone Site or other toxic waste sites in Tifton. Of the comments that were
related to EPA's proposed remedy, there was a favorable response to EPA's proposed
groundwater pump and treat remedy but disfavor for EPA's proposed
bioremediation remedy for soil cleanup. The commentors felt the bioremediation
remedy was too experimental, would not cleanup the soil adequately, and that they
preferred a remedy that was known to effectively treat the contaminated
contamination. They also preferred a remedy that would be implemented in a
relatively short time frame and one that would expose the community to the least
risk. During the public meeting the impression was that the commentors preferred
the contingent remedy of low temperature thermal desorption over bioremediation.
Many written comments re-emphasized the major concerns but did not designate a
specific remedy preference.
n.
Background on Community Involvement and Concerns
EPA has taken the following actions to insure that inter~sted parties have been kept
informed and given an opportunity to provide input on activities at the Marzone
Inc./Chevron Chemical Company Superfund Site.
On June 24, 1991 an availability session was held in the Tifton Neighborhood Services
Center, on Golden Road to inform the community of the start of field work for the
Remedial Investigation. At that time community interviews were conducted and a
repository was set up at the Tifton and Tift County Libraries in Tifton, Georgia. A
second availability session took place on January 20, 1994 in the Neighborhood
Services Center to inform the public of the results of the Remedial Investigation and
the proposed alternatives for remediation.
On April 7, 1994 a third availability session was held to better define the remedial
alternatives presented in the Feasibility Study. In addition, on January 5, 1994 EPA
held a public meeting in the Tifton Library to announce that Tifton/Tift County,
Georgia was selected as Region IV's focus for the Environmental Justice initiative. At
that time a summary of the activities at the Marzone Site was presented.
A-3
-------
The public comment period on this ROD was July 15, 1994 through August 15, 1994.
The comment period was extended 30 days until September 14, 1994 upon two
requests received by EPA. A public meeting was held on July 26, 1994 where
representatives from EP A answered questions regarding the Site and the proposed
plan under consideration. The administrative record was available to the public at
both the information repository maintained at the Tifton and Tift County Libraries
and at the EPA Region IV Library at 345 Courtland. Street in Atlanta, Georgia. The
notice of availability of the proposed plan and the administrative record was
published in the TUton Gazette on July 11, and July 18, 1994.
ill.
Summary of Major Ouestions and Comments Received During the ~
Comment Period and EP A's responses
Comment 1: Two commentors suggested that alternative #6, Excavation and
Landfilling, be selected as the final remedy for the Site. They stated that #6 would be
the fastest way to cleanup the Site.
EPA Response 1: EPA is required to use the nine criteria which are listed on page
of this ROD to determine the best remedy for NPL sites. Also it is a congressional
preference that EP A select remedies that use treatment technologies that result in
permanent solutions. The excavation and landfilling alt~rnative does not meet the
preference for a treatment option nor is it a permanent remedy. Excavation and
landfilling would entail digging up contamination from on-site and transferring it to -
a landfill in another neighborhood, and is just the situation that Congress was trying
to avoid by directing the Agency to consider on-site treatment option that result in a
permanent remedy creating the potential for accidents, spillage and community
concerns in other states.
Comment 2: One commentor suggested that alternative #9, Chemical Oxidation, be
selected as the. final remedy for soils of OU1 of the Site.
Response 2: Although chemical oxidation is a treatment alternative, it does not result
in a permanent solution for OUI of the Site. After the contaminated soil is treated it
will still have to be disposed of in an appropriate land£ill. This will entail
transferring a waste, treated or untreated, from one neighborhood to another. Since
the state of Georgia does not have a operating hazardous waste landfill, this waste
may have to be shipped over state lines.
Comment 3: A PRP suggested that the remedy for OUI of the Site entail building a
box that is of reinforced concrete on the sides and bottom and lined on the top with
waterproof material. The contaminated soil should be placed in this box and mixed
A-4
-------
with lime. On top of this structure a building could be constructed for industrial
usage.
Response 3: This suggested unit of a "concrete box" would be defined as a landfill
Wlder the Resource Conservation and Recovery Act (RCRA) and would have to meet
the minimum technology requirements (MTRs) and Land Disposal Restrictions
(LDRs) of 40 CPR 264 and 270. The design as described by the commentor does not
fulfill any of these requirements. The alternative of an on-site landfill was explored
in the FS and rejected because of the difficulties associated with the regulatory
restrictions; some of which are set out above. The FS contains a detailed explanation
of the inadequacies and feasibility of an on-site landfill.
I
Comment 4: One commentor supported the proposed plan's preference for
bioremediation of soils at aUl of the Site. He stated that the bioremediation option
appears to have more positive elements than other options, and is more
environmentally friendly. He also stated that the option would provide critically
needed revenue or research not available from public funds, and that the option
would have a positive economic impact on the local community.
Response 4: EP A does not disagree with these statements. These are a few of the
reasons that EPA's original proposed plan for soils at aUl of the Site was
bioremediation. On the other hand, the biofarming/ cropping option has not yet been
proven in reducing pesticide residues in soil. In addition, if successful, the
bioremediation alternative would not be able to remediate the soils down to the
cleanup levels based upon a lxlcr risk as would other ~ternatives including the low
temperature thermal desorption alternative. ..
Comment 5: Another commentor was also in favor of the bioremediation alternative,
saying that it would be the least offensive to sWTounding neighbors and bring the
least adverse economic impact on the City. This commentor also had a concern over
the thermal desorption alternative stating that it would result in problems if used.
People would be concerned about dust, noise, and emissions.
Response 5: The low temperature thermal desorption alternative is one that has been
proven for use for pesticide residues in soils similar to those at aUI of the Site. This
remedy was used at an NPL site in Albany, Georgia less than 100 miles from Tifton.
In Albany residents were concerned at first about the use of the thermal desorption.
unit, but after start-up and completion of the project, most of those residents fears
dissipated as they became more familiar and comfortable with the technology. The
mobile unit, although occupying a large space, is designed to control dust, noise, and
emission very effectively. The system is designed with a safety in that it shuts down
automatically when it doesn't function properly. However, the unit is constantly
monitored by a technician.
A-5
-------
Comment 6: One commentor asked how many toxic substances affect residents at
this Site. This commentor stated that the proposed plan fact sheet was not clear on
who was at risk.
Response 6: A detailed analysis of the risks presented by OUI of the Matzone Site is
presented in the Baseline Risk assessment (BRA) which is part of the Administrative
Record (AR) for the Site. The BRA identified 28 potential chemicals of concern at
QUI of the Marzone Site. In addition, it identified a current risk to individuals from
direct contact, inhalation, and ingestion of contaminated soils at the Site. Those
individuals that would be most at risk would be on-site workers, since the Site is
fenced and posted "no trespassing." Any trespassers may also be at risk from
contaminated soils. There is a future risk for ingestion of contaminated groundwater.
Currently, the groundwater contaminant plume is localized under the Site and has
not migrated to private or public drinking water. If this plume were not cleaned up,
it would present a risk in the future by potential migration to drinking water wells.
In addition, there is a risk to the groundwater from contamination of subsurface soils.
If subsurface soils are not remediated they would continue to release contaminants to
the underlying aquifer. For a thorough explanation of the contaminants of concern
and Site risks, the commentor may wish to read the Baseline Risk Assessment
available in the repository.
Comment 7: A commentor asked why toxaphene and DDT increase as a result of
remediation.
Response 7: Toxaphene and DOT do not increase as a result of remediation. The
toxaphene and DDT in surface soils will be remediateJi to 0.7 ppm and 2.29 ppm
respectively. Unlike the other 7 contaminants identified in the proposed plans for
subsurface soil contamination, toxaphene and DOT are not considered to be a threat
for leaching to the underlying aquifer because they tend to adhere to the soil particle.
This conclusion was determined by use of a mathematical model that calculates the
potential for a chemical to leach out of soil. The modelling generated a cleanup
value of 2,700 ppm for toxaphene and 1,300 ppm for DDT in the subsurface soils
which are higher than any values of these chemicals detected at subsurface soil
during the RI.
Comment 8: A commentor asked how water can remove an immiscible liquid This
commentor postulates that the xylenes found in the aquifer underlying OUI of the
Site is not dissolved in the groundwater but is instead present in a layer on top of the
groundwater, and therefore, cannot be remediated by EP A's remedy of pump and
treat.
Response 8: It is the opinion of EP A's experts in hydrogeology that the xylenes
found at OUI of the Marzone Site is mixed with groundwater. This opinion is based
upon current site conditions, extensive reviews of the remedial investigation and
A-6
-------
other groundwater investigations conducted at the Site. In addition it is EPA's
opinion that a well designed groundwater pump and treat system will~ in fact,
cleanup all contaminants found in the groundwater including the xylenes. This
remedy has been employed many times for aquifers contaminated with organic
constituents such as xylene and has proven to be effective.
Comment 9: A commentor asked why there were no backup alternatives proposed
for water treatment?
Response 9: There were three alternatives in the feasibility study that were evaluated
for cleanup at the Site. -The only alternative that met all nine criteria of evaluation
was the pump and treat remedy. This remedy is well proven and effective. It has
been used innumerable times in the past on aquifers contaminated with xylenes and
other organic constituents that are found at this Site. EP A believes this remedy will
adequately address groundwater contamination at this Site.
Comment 10: A commentor asked why there is no treatment proposed for
subsurface contamination.
Response 10: Both the proposed plan and the final selected remedy contain a remedy
for subsurface soils. The proposed plan presented the remedy of bioremediation
through biofarming/ composting for both surface and subsurface soils with a
contingent remedy of low temperature thermal desorption. The final remedy for
aUl of the Marzone Site is for low temperature thermal desorption of both
contaminated surface and subsurface soil. Cleanup levels for surface and subsurface
so~ are set out in Table 1 of the proposed plan and Table 12 of the ROD.
Comment 11: A commentor asked why use peanut fanning to remove contaminants.
This commentor stated that he does not believe that peanuts will uptake pesticide
residues and that the proposed alternative of peanut farming would not work.
Response 11: It is the opinion of EPA experts that reviewed the information
regarding peanut farming that the alternative should be strongly considered as a
viable option to remediating pesticide contaminated soils at the Site. EP A realizes
that the peanut farming option is innovative and would require treatability testing to
determine if the remedy would be successful. EP A never envisioned following
through with the biofarming remedy if it failed to prove successful during the
testing. Due to the great deal of concern from many individuals over this highly
innovative option, EPA has defaulted to the low temperature thermal desorption
alternative for remediation of contaminated soils at aUl. Low temperature thermal
desorption is a well proven technology. It is permanent and can be implemented in a
shorter time frame.
A-7
-------
Comment 12: A commentor asked what is a "hot spot?" This phrase is used in the
proposed plan to describe areas where soil will be excavated before bioremediation.
Response 12: With regard to bioremediation of soils at OUl, the phrase "hot spot" is
clearly defined in the PS, which is part of the AR for the Site. It is defmed as
biocidal soils or that soil who's concentration of pesticide residues are so high that
the bioremediation option would be unsuccessful. In other words the concentrations
of contaminants in the soils would kill the biological organism that could be used in
the bioremediation remedy. EPA apologizes for not clearly defining the term in the
proposed plan.
Comment 13: A commentor asked how the offer of local jobs would benefit the
community.
Response 13: EP A was not offering local jobs. Rather, a component of the
bioremediation option was the use of labor from the local work force to implement
the biofarming/composting option. H the bioremediation remedy was selected this
information would have been developed as part of the remedial design dwing which
time the detailed plans would be developed for the remedy and the costs would be
properly evaluated.
Comment 14: A commentor asked, ''Have all of the chemicals at this Site been
found?" The commentor believes that EP A should require a thorough grid search of
the Site and employ geophysical techniques to determin~ if there are any buried
drums at the Site. . i
Response 14: EPA believes a thorough investigation was undertaken for OUI of the
Marzone Site. A 2 year remedial investigation was completed which included
extensive sampling of groundwater, soil, surface water, and sediment at the Site.
This investigation yielded enough information for EPA to select a remedy for
contamination found at OUI. Geophysical techniques were not employed during the
RI because they were not deemed necessary or appropriate for the nature of the
investigation at the Site. A magnetometer survey would have been unsuccessful due
to interference by metal buildings and objects on-site along with a nearby railroad.
track and overhead power lines. Ground penetrating radar is a technique that would
not have, in EPA's opinion, generated useful information about buried drums or
contaminated media. A seismic survey would not have been useful since it is not an
appropriate techniques for determining the loeation of buried drums. The
appropriateness of geophysical techniques at Superfund sites is detailed in an EP A
document entitled, "Geophysical Techniques for Sensing Buried Wastes and Waste
Migration," Environmental Monitoring Systems Laboratory, Office of Research and
Development, U.s. EPA, Las Vegas, NY, 1982.
A-8
-------
Comment 15: A conunentor asked how long the Site would remain toxic after
remediation?
Response 15: OUI of the Marzone Site will not remain toxic after cleanup. The
selected remedy of low temperature thermal desorption will remediate Site soil to a
risk level of lxl£r which is appropriate for residential use. The original proposed
alternative of bioremediation would have remediated the Site to a lxl(rs risk level
appropriate for industrial use.
Comment 16: A PRP commented that the proposed plan was too specific and may
conflict with the optimal design of the remedial design .
I
Response 16: EPA believes that the level of specificity is appropriate to achieve the
purpose and goals of the proposed plan. The proposed plan must have sufficient
information for the public to understand the options being explored and EP A's
preferred alternative. In turn, the ROD must determine the scope of the remedy and
provide the basis for the design.
Comment 17: A PRP commented that it is generally supportive of the proposed plan
and favors the bioremediation alternative. It states that EPA did not justify the
selection of thermal desorption, and it prefers that excavation and landfilling or
chemical oxidation be selected over thermal desorption.
Response 17: As stated in responses above, both landfilling and chemical oxidation
do not meet the preference for selection of treatment remedies that yield permanent
remedies. In evaluating the nine criteria for remedy selection both the
biQremediation and thermal desorption alternatives are highly preferred because they
result in permanent remedies.
Comment 18: A PRP commented that the total cost of the cleanup proposed in the
fact sheet could be in excess of the $8.6 million stated since some fraction of the $2.7
million bioremediation option would be expended if the bioremediation option failed
the treatability test.
Response 18: EP A agrees that undertaking the contingent remedy could have
entailed expenditure of some fraction of the $2.7 million bioremediation remedy, but
the cost of the study is subject to a multiple cost variable in a manner similar to the
outcome of the study itself. EP A believes that $8.6 million presented in the proposed
plan was a reasonable estimate.
Comment 19: A PRP commented that the decision to use an infiltration gallery in the
groundwater pump' and treat alternative should be delayed until after further testing
(e.g. column leach test) of the aquifer. It further commented that it is technically
impracticable to pump and treat the groundwater and that use of an infiltration
A-9
-------
gallery may enhance contaminant migration in undesired directions.
Response 19: EP A believes that in order to fully remediate the contaminated aquifer
an infiltration gallery should be installed. From the information compiled in the RI it
is evident that the aquifer is a slow moving one. The use of an infIltration gallery on
slow moving aquifers to enhance contaminant migration to extraction wells is an
often used teclmique and was included in a draft of the FS prepared for the Site
which is part of the AR. Delaying the remediation of the contaminated groundwater
by further testing this aquifer is not justified by the existing data. It is a well proven
technology and has been used in the past on aquifers and hydrogeology very similar
to that at QUI of the Marzone Site. A well designed groundwater pump and treat
system and a well designed infIltration gallery will enhance migration of
contaminants to the desired location of the extraction wells. The groundwater pump
and treat remedy at QUI of the Marzone Site will be carefully designed so that
contaminants do not migrate in undesirable directions.
Comment 20: A PRP commented that the proposed plan is misleading because it
implies that a no action groundwater remedy will not improve the groundwater
quality. However, source remediation conducted on-site will improve the
ground~ater quality.
Response 20: The no action remedy for groundwater will not improve the current
conditions of the contaminated groundwater. Source remediation will only remove
any future or further contamination of the aquifer; it ~ not improve the current
. groundwater quality. .
Comment 21: A PRP commented that the proposed plan states that pump and treat
will meet ARARs in less time than no action; but that this is unsupported by the FS,
which states that there is no significant differences between groundwater alternatives.
Response 21: EP A believes that it is clear that the active pump and treat alternative
for the contaminated aquifer, enhanced with an infiltration gallery, would remediate
a contaminated aquifer in less time than a no action alternative or natural attenuation
alternative. The pump and treat remedy will be made more effective by inducing a
capture zone for the contaminants. This capture zone is enhanced by forces of the
infiltration gallery and any naturally attenuative properties of the contaminants
present. Moreover, the pump and treat remedy is the only alternative that meets the
ARARs for the groundwater at QUI. .
Comment 22: A PRP commented that there is a radical difference between EPA's soil
cleanup levels for the Marzone Site and the levels for the EP A removal activities at
the Golden Seed Site.
ReSJ'onse 22: The goal of EP A's removal activities at the Golden Seed Site was to
A-I0
-------
abate an imminent and substantial endangerment to human health and the
environment, not to cleanup the Site to risk-based levels; removal activities at Golden
Seed eliminated the emergency. The goal of the cleanup at aUI of the Marzone Site
is to remediate the soils and groundwater to levels that are within EPA's risk range
of Ixlo-' to Ixlcr which yields different standards than those developed for the
Golden Seed removal activity.
Comment 23: A PRP asked why filtration was chosen over an afterburner on the
thermal desorption unit?
Response 23: EP A has not chosen filtration over an afterburner for the thermal
desorption unit. This determination will be made through the remedial design
process.
Comment 24: A PRP commented that EP A should mention the economic
development of each option on the community. The commentor estimated that over
50% of the bioremediation expenditures would be made locally versus less than 5%
for the other soil remediation options.
Response 24: Economic development is not one of the nine criteria in selecting a
remedy or cleaning up a Superfund site and was not taken into consideration in the
FS or in selecting the final remedy for aUI of the Marzone Site. Moreover,
percentages provided by the commentor are broad estimates since there is very little
known with respect to economic development arising from Superfund sites.
Comment 25: A PRP disagreed that the Site should be cleaned up to a level suitable
for future residential use. The Site is adjacent to the main line of a railroad and is
currently zoned for industrial usage.
Response 25: It is EP A policy to use a IxIcr' risk levels as a point of departure for
determining site-specific cleanup levels. Deviation from the lxlcr' risk level is
determined based upon justifiable evidence. EP A does not agree that because
property is currently zoned as commercial it will continue to be zoned commercial;
EP A has commented extensively on this issue. The facts are: There is a trailer on the
Slack property within yards of the area designated as OUI, in the past someone
lived in this trailer; there is a red brick house within 500 feet east of the Site that is
residential; there are a half dozen houses within 500 feet west of the Site, and just
beyond these houses is a heavily populated residential area in and around Golden
Road An examination of the areal photographs from the Site from 1948 to 1988
shows an enormous encroachment of residential communities into the area of the
Site. There is a high potential that this residential encroachment will not discontinue.
Therefore, EP A does not agree that the future use of this property must remain
commercial even though it is currently zoned commercial and it is adjacent to a
railroad line.
A-II
-------
Comment 26: A PRP disagreed that the contaminated aquifer requires pumping and
treating by stating that there is no evidence of the need in the FS. It was further
stated that although state and community acceptance may modify EPA's evaluation
criteria, the "limited informed public involvement" in the remedy selection process at
the Site does not warrant the selection of any remedy other than institutional
controls.
Response 26: Since the groundwater underlying QUI of the site is contaminated, the
pump and treat is the only remedy that meets the threshold criteria of protection of
human health and the environment and compliance with ARARs. GaEPD has
classified the aquifer underlying the Marzone Site as a potential drinking water
aquifer. Drinking water must meet certain standards which are either established
Maximum Contaminant Levels (MCLs), non-zero MCL goals or an appropriate risk-
based level for those chemicals without MCLs. Contaminated groundwater must be
treated to these standards at this Site.
Comment 27: A PRP claimed that the bioremediation option for soil cleanup is
warranted but that the selection of a more expensive soil and subsurface soil remedy
at the Site would add nothing to the Site remedy other than targeting cleanup levels
to residential use, a use that is "clearly prohibitive."
Response 27: EP A disagrees with the commentors state~ent. The low temperature
thermal desorption remedy outweighs the bioremediatioh remedy in more that just
its ability to remediate soils to a level appropriate for residential land use. Low
temperature thermal desorption can be implemented in approximately one year while
bioremediation may take 3 to 7 years. Low temperature thermal desorption is a
proven technology; it has been used in the past to break down pesticide
contaminated soil. The biofarming/ composting alternative is innovative and has
never been used. Thermal desorption is a proven technology, and it will be easier to
implement. These criteria outweigh the cost factor when evaluating remedies.
Comment 28: A commentor requested that the groundwater remedy include
language which would require the remedy to be changed if a new, more effective
alternative would become available in the future.
Response 28: Under the NCP, EPA is required to complete a review of the remedy
after a 5 year period. At that time if EP A determines that the remedy is ineffective or
needs modification, a ROD amendment can be issued. Also, if new information
becomes available at any time that may affect the selected remedy, EP A can, if
appropriate, issue a ROD amendment to modify the remedy.
A-12
-------
Comment 29: A commentor requested that if biofarming didn't work EP A should
consider chemical treatment rather than thermal desorption; chemical treatment
would yield less risk to the community than thermal desorption. The concern was
that nearby residents should not be unfairly impacted by the cleanup.
Response 29: EP A agrees that nearby residents should not be unfairly impacted by
the cleanup, however, chemical treatment is not a permanent remedy and hence not
preferred over low temperature thermal desorption. Moreover, the chemical
treatment remedy would entail transport of either treated or untreated material
through the community and therefore would also impact the community. If soil
treatment were to occur on-site, the risks posed would be similar to thermal
desorption. !
Comment 30: A commentor stated that the composting/landfarming plan was too
vague in some respects and requested additional information on the bioremediation
parameters be included in the ROD.
R~onse 30: The ROD has been refined and low temperature thermal desorption was
determined to be is the final remedy selected for soil remediation at Marzone OUI.
Therefore the detailed information about bioremediation is not necessary.
Comment 31: A commentor stated that one of the ARARs for the remedy is the
Georgia Hazardous Site Response Act, O.C.G.A S12-8-93(b), Chapter 391-3-19, that
identifies soil cleanup standards for corrective action.
Response 31: Cleanup standards contained in the regulations promulgated pursuant
to ~e Georgia Hazardous Site Response Act are not ARARs for the remedy at OUI
of the Marzone Site because CERCLA stipulates that a State's cleanup standards must
be "timely identified" to be ARARs. The NCP contemplates that this need for
timeliness requires ARAR-identification to occur during the early stages of the
comparative analysis of alternatives; the purpose of the requirement is to avoid a
duplication of efforts and inordinate delays in the cleanup. The State's regulatory
requirements for corrective action under the Hazardous Site Response Act were not
adopted until well after EP A's Baseline Risk Assessment was finalized, became
effective only after the Feasibility Study Report was issued, and were identified to
EP A subsequent to publication of the proposed plan and the public meeting.
The selected remedy remains protective of human health and the environment even
though the ROD does not contemplate or require a cleanup of each contaminant at
OUI of the Marzone Site to levels that might be required under the State's new
coITective action regulations. In addition, exclusion of the. S~te'.s corrective action
requirements as an ARAR for this ROD due to "timeliness" should not necessarily
exempt any person otherwise subject to the Hazardous Site Response Act from the
requirements contained in the State's new regulations.
A-13
-------
Comment 32: A PRP commented that the acceptability of the selected remedy to the
community is extremely important to its successful implementation. It stated that
n[b]yall accounts, the public meeting held in July was less than successful in
communicating the pros and cons of the various remedies. Many of the people
. present were more interested in cash settlements than site cleanup. The hysterical
nature of the meeting inhibited more thoughtful, moderate feedback. Many other
interested elements of the Tifton community were not represented. Given the small
size of Tifton (14,000 residents), we strongly urge EP A to seek out input from a wider
cross section of the community, including nearby residents, business, academia, city
and county government, and the farm commwrity. We believe that it is imperative
that the comm1IDity provide "informed consent" to EP A's selected remedy.
Otherwise, we run a tremendous risk of opposition and litigation which may stall the
implementation of the selected remedy. Especially if the selected remedy is Thermal
desorption. We believe that because this technology is a variant of incineration, an
informed community will oppose it."
R~onse 32: The comments received by EP A, both verbally and in writing, on the
proposed remedy for OUI of the Marzone Site, were from a broad cross section of
the interested public. This is a result of the extensive community outreach EPA has
conducted in the Tifton and Tift County area of Georgia. A summary of this
community outreach is presented in the overview section of this responsiveness
. summary. In essence, EP A has conducted four public meetings in the past eight
months to inform and update the commwrity on the activities of the Marzone Site
including discussions of cleanup alternatives. Two distiJ;\ct meetings were set up just
for the purpose of discussing the cleanup alternatives for the Marzone Site. In
addition, EPA has met with the local government of TUton on two separate occasions
to inform and update them on the activities of the Marzone Site. One of those two
meetings was specifically for the pwpose of informing them of EP A's proposed
remedy at OUI. EPA has had numerous telephone and personal conversations with
interested persons regarding the cleanup. These interested persons have ranged from
current nearby residents, to scientists, to member of environmental organizations, to
member of Tifton neighborhood organizations; all of which have submitted
comments on EP A's proposed plan. Over twenty comment letters were submitted by
the interested public and over 200 people attended the public meeting held on July
26, 1994. Previous meeting have also yielded over 100 attendees. This is more than
the usual participation for an NFL Site in Region IV.
Also, EP A placed two full page advertisements in the Tinon Gazette announcing the
public comment period and public meeting. Another two full page advertisements
were run when EP A extended the comment period for the proposed plan. EP A sent
four videos addressing the suite of remedies evaluated for OUI, including low
temperature thermal desorption, to the Neighborhood Services Center in Tifton. It is
our understanding that interested parties have viewed these videos.. EP A has
provided the community with various handouts addressing the suite of alternatives
A-14
-------
evaluated for the OUI cleanup. Hundreds of these handout have been distributed
and received by the community. EP A has gone above and beyond requirements to
reach all segments of the community and interested parties with regards to the
activities at the Marzone Site. A repository has been set up in the Tilton Library
which contains important documentation about the remedy at the Site. The librarian
indicated that the repository was being used by the community.
One commentor could not endorse the thermal desorption plan, yet another
commentor, a nearby resident, stated that the low temperature thermal desorption
remedy sound fIne as long as there is no risk of explosion or any form of radiation.
Of course all measures will be taken to ensure that an explosion never occurs, and
radiation is not a threat' at this site. Therefore, EPA believes the comments and
concerns regarding the cleanup at OUI of the Site were from a broad cross section of
a well informed public.
A-IS
-------
RECORD OF DEOSION
APPENDIX B
STATE CONCURRENCE LElllili.
Marzone, Inc./Chevron Chemical Company Site
Tift County, Georgia
Record of Decision (OUI)
Marzone, Inc./01evron O1emical Coutpany Site
-------
SEP 30 '94
04: 04PM DNR EPD HWMB
. P.2
Georgia Department of Natural Resources
205 Butler Street, S.E., Suite 1154, Atlanta, Georgia 30334
Joe D. Tanner, CommIssioner
. EnVironmental Protection Division
Harold F. Reheis, Director
404/55&-7802
September 30. 1994
Ms. Joanne Benante
Remedial Project Manager'
South Superfund Remedial Branoh
U.S. Environmental Protection Agency
Region IV
345 Courtland Street, N.E.
Atlantal Georgia 30365
I
RE: Interim Record of Decision (ROD)
Marzone NPl Site
Dear Ms. 8enante:
This correspondence shall confirm receipt of the July 25, 1994 8Draft Record of
Decision for Operable Unit 1 of the MarzonelChevron Superfund Site in Tifton, Georgia, a
received by the Environmental Protection Division (EPD) on July 27, 1994. Based on the
review of the latest modification to the draft Interim RODI the EPD concurs with those
selected remedIes set forth in the Interim ROD but must defer concurrence of the specific
performance standards identified in the selected remedies.
Remedies acceptable to the EPD for contaminated soil and groundwater within that
area specified as Operable Unit 1 of the Marzone/Chevror) Superfund Site are as follows:
.
Extraction of contaminated groundwater with subsequent treatment prior to infiltration
through an infiltration gallery. Spent carbon filters generated by the treatment
process shall be transported off-site. Infiltration of treated groundwater shall further
facilitate the extraction of contaminated groundwater. Groundwater monitoring shalf
be implemented to determine the effectiveness of the remedy as well as to assure
effective groundwater treatment prior to infiltration.
Excavation of contaminated soil with subsequent treatment using Low Temperature
Thermal Desorption. Treated uncontaminated soil will remain on..site. Contaminated
residues generated by the treatment process shall be transported off-site to an
authorized Incinerator.
.
Under the terms and conditions of CERCLA Section 121(d){2}(iJ} and the NCP,
fttimely identification II of pertinent provisions of the Georgia Rules for Hazaroous Site
Response, Chapter 391 .3.19 ~ sea. (uu,e Rulesll) as Applicable or Relevant and
Appropriate Requirements (ARARs) was not possible given that during the formative
stages of the Feasibility Study. the Rules had yet to become formally adopted or officially
effective. In thIs instance, in an effort to expedite source removalI prevent further
. migration of contaminants from this site, prevent inordinate delays in the clean-up and
avoid duplication Of effort, the ePD does not intend to identify specific performance
standards set forth in the Georgia Rules for Hazardous Site Response as ARARs for
those selected remedies at Operable Unit 1 of the Marzone/Chevron Superfund Site.
-------
SEP 30 ' 94 04: 05PM DNR EPD HWMB
P.3
Ms. Joanne Benante
September 30, 1994
Page Two
. Should you require further clarifications please oontact Andrew Taft at
(404) 656-7802.
Sincerely,
Harold F. Rehels
Director
HFRlat
File: Marzone (B)
RMNDYiWlZONt'oCONCUR:I.!IOO
------- |