United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R04-93/150
August 1993
c/EPA Superfund
Record of Decision:
Rochester Property, SC
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S0272-101
REPORTDOCUMENTA~ON 11. REPORT NO. 2. 3. A8c1pl8nt'. AccM8lon No.
PAGE EPA/ROD/R04-93/150
4. TiIIII and Subtitle 5. Report Data
SUPERFUND RECORD OF DECISION 08/31/93
Rochester Property, SC 6
First Remedial Action - Final
7. Aulhor(.) a PwformIng 0rpnIDt1on Rapt. No.
9. Performing Organization f!Iame and Add- 10 Proj8c:t TukIWork Unit No.
11. Contract(C) Of Gram(G) No.
(C)
(G)
12. SponaorIng Organization Name and Add,.. 13. Type of Report & PerIod Cclv8l'8Cf
U.S. Environmental Protection Agency
401 M Street, S.W. 800/800
Washington, D.C. 20460 14.
15. Suppl8m8ntary Not..
PB94-964027.
16. Abstract (Umlt: 200 words)
The 4.5-acre Rochester Property site is a former waste disposal area located in
Travelers Rest, Greenville County, South Carolina. Land use in the area is mixed
residential, agricultural, and recreational, with woodlands on the northern portion of
the site. Two small, unnamed tributaries flow into Armstrong Creek from each side of
the site and overlie surficial saphrolite aquifers. The people who reside within
one-half mile of the site use municipal water and water supply wells to obtain their
drinking water supply. From 1971 to 1972, the site was used for the disposal of
various types of waste, including wood glue, print binders, powder materials, natural
guar gums, and adhesives. The waste was placed in four onsite trenches that were
approximately forty feet long by three feet wide by 10 feet deep. In 1984, 1987, and
1988, State and EPA sampling and site investigations identified significant
contamination as a result of these improper disposal activities. In 1989, EPA required
the PRP to remove the waste and perform sampling to document the effectiveness of the
waste removal. In 1990, the buried waste was excavated and disposed of off site at a
hazardous waste facility. Thi~ ROD addresses a first and final remedy for the
potential future risk posed by use of the onsite contaminated ground water. The
(See Attached Page)
17. Document An8/y8I8 L Descriptors
Record of Decision - Rochester Property, SC
First Remedial Action - Final
Contaminated Medium: gw
Key Contaminants: VOCs (TCE), other organics (PAHs), metals (manganese)
b. IdentIfl8rs/Op8n-Ended Terms
Co COSAT1 FI8IcL'Group
18. AY8lJablJity Stat81118m 19. Security CI888 (ThIs Report) 21. No. of Pagn
None 58
2D. Security au. (This P9l) 22. Pr\c8
None
(See ANSI-Z3U8)
S.ln6ttut:tioM on R.,,-
OPTIONAL FORII m (4-77)
=-~
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EPA/ROD/R04-93/150
Rochester Property, SC
First Remedial Action - Final
Abstract (Continued)
primary contaminants of concern affecting the ground water are VOCs, including TCE; other
organics, including PARs; and the metal, manganese.
The selected remedial action for this site includes installing air sparging trenches and
air sparging wells, if necessary; treating the contaminated ground water in-situ using air
sparging to remove TCE, promote the biodegradation of bis(2-ethylhexyl)phthalate, and
oxidize soluble manganese to its insoluble form, via the addition of oxygen, causing the
insoluble manganese to precipitate and be re-deposited to the soil; installing vent pipes
or another venbing system through the subsurface to facilitate vapor discharge; conducting
bench and/or pilot treatability studies to assess the effectiveness of the remedy, if
necessary; monitoring ground water, surface water, and air; and implementing institutional
controls, including deed, ground water, and well use restrictions. The estimated present
worth cost for this remedial action is $2,681,000, which includes an estimated annual O&M
cost of $156,500.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific ground water cleanup goals are based on SDWA MCLs and a risk-based level
for manganese, and include bis(2-ethylhexyl)phthalate 0.006 mg/l; manganese 0.18 mg/l; and
TCE 0.005 mg/l. .
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RECORD OF DECISION
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
ROCHESTER PROPERTY SDPERFDND SITE
TRAVELERS REST, GREENVILLE COUNTY
SOUTH CAROLINA
PREPARED BY:
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
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DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND LOCATION
Rochester Property Site
Travelers Rest, Greenville County, South Carolina
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for
the Rochester Property Superfund Site (the Site), located in
Travelers Rest, Greenville County, South Carolina, which was
chosen in accordance with the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980 (CERCLA), as
amended by the Superfund Amendments and Reauthorization Act of
1986 (SARA), 42 U.S.C. ~~ 9601 et sea., and, to the extent
practicable, the National Oil and Hazardous Substances
Contingency Plan (~CP), 40 C.F.R. Part 300 et seq. This decision
is based on the administrative record file for this Site.
The State of South Carolina concurs with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this
Site, if not addressed by implementing the response action
selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.
DESCRIPTION OF THE SELECTED REMEDY
This remedial action addresses groundwater contamination.
The major components of the selected remedy include:
o
In-situ air sparging which will be accomplished by
pumping air, through trench(es), and possibly wells, in
the. saturated zone, creating a steady flow of gas, or
bubbles, that rise through the aquifer;
o
Vent pipes or other venting system(s) will be placed in
the subsurface to facilitate vapor discharge from the
vadose zone.
-------
o
The rising bubbles will contact the dissolved organic
contaminant and allow the trichloroethene (TCE) to
volatilize.
o
The addition of oxygen to the groundwater will
promote biodegradation of bis(2-ethylhexyl)phthalate
and oxidation of soluble manganese to its insoluble
form. .
o
The insoluble manganese will then precipitate and be
re-deposited in the soils, where it is already
naturally occurring.
SITE MONITORING
o
Regular sampling of the groundwater and surface water
to monitor the concentrations and movement of
contaminants.
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 utilizes
permanent solutions and alternative treatment technology to the
maximum extent practicable for this Site. The selected
groundwater remedy satisfies the preference ~or treatment.
Since selection of this remedy will result in contaminated
groundwater remaining on-site above health-based levels until the
remedial action is complete, a statutory 5 year review will be
performed after commencement of the remedial action to insure
that the remedy continues to provide adequate protection of human
health and the environment.
G~h7~
Patrick M. Tobin
Acting Regional Administrator
~ 31; /99.1
Date
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TABLE OF CONTENTS
iv
SECTION
1.0
2'.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
PAGE
SITE LOCATION AND DESCRIPTION
............................ .1
SITE HISTORY AND ENFORCEMENT ACTIVITIES ............. ......4
HIGHLIGHTS OF COMMUNITY PARTICIPATION .....................5
SCOPE AND ROLE OF THIS ACTION WITHIN SITE STRATEGY ........5
SUMMARY OF SITE CHARACTERISTICS.......................... '.5
5 . 1 Meteorology....... ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2 Geologic and Hydrogeologic Setting ..................6
5 .2 . 1 Geology / Soils. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2.2 Hydrogeology,............................... 12
5.3 Nature and Extent of Contamination .................13
SUMJo1ARY OF SITE RISKS............................. '. . . . . . .14
, 6. 1 Contaminants of Concern............................ 15
6.2 Expos'..1re Assessment................ . . . . . . . . . . . . . . . .16
6.3 Toxicity Assessment of Contaminants ................17
6.4 Risk Characterization ..............................18
DESCRIPTION OF GROUNDWATER REMEDIAL ALTERNATIVES.......~..20
7 . 1 No Action. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
7.2 Institutional Controls and Access Restrictions .....27
7.3 In-Situ Air Sparging ............................ ...28
7.4 Groundwater Extraction and Treatment ...............29,
SUMJo1ARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES ..........31
8.1 Groundwater Remediation Alternatives ...............31
8.1.1 Threshold Criteria ..........................31
8.1.2 Primary Balancing Criteria ..................34
8 . 1. 3 Modi fy ing Cr iter ia .......................... 37
THE SELECTED REMEDY............. ~ . . . . . . . . . . . . . . . . . . . . . . . . 37
9.1 Groundwater Remediation ............................37
9.1.1 Description................................. 38
9.1.2 Applicable or Relevant and Appropriate
Requirements (ARARs)........... .... ..........40
9 ~ 1. 3 Performance Standards....................... 42
9.2 Monitor Site Groundwater and Surface ...............43
STATUTORY DETERMINATIONS ..........'......................43
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LIST OF APPENDICES
v
APPENDICES
APPENDIX A - RESPONSIVENESS SUMMARY
APPENDIX B - STATE LETTER OF CONCURRENCE
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LIST OF FIGURES
vi
FIGURE
PAGE
1
2.
3
'4
5
6
7
Site Location Map
................................... .2
Site
Layou t Map ...................................... 3
Surface Soil Sampling Points .........................7
Subsurface Soil Sampling Points .........'.......~.....8
Groundwater Sampling Points ..........................9
Stream SedLmentSampling Points ........'...,.........10
Surface Water Sampling Points .......................11
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I--
I
LIST OF TABLES
vii
TABLE
PAGE
1
Screening of Remedial Technologies...................21
. 2
Comparative Analysis of Alternatives ................32
3
Remediation Levels (Rls) - Groundwater...............43
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DECISION SUMMARY
ROCHESTER PROPERTY SUPERFUND SITE
TRAVELERS REST, GREENVILLE COUNTY, SOUTH CAROLINA
Page 1
1.0
SITE LOCATION AND DESCRIPTION
The Rochester Property Site (the Site), is located in a rural
unzoned portion of Greenville County, South Carolina,
approximately (3) three miles west of the town of Travelers Rest
(Figure 1). The Site is located north of County Road 268 and
approximately one-quarter mile east of County Road 102. The Site
lies approximately 300 feet north of County Road 268, also known
as Ledbetter Road, on property currently owned by Carolina
Properties, Greenville, Inc. The Site's geographic coordinates
are 34°58'17.1" north latitude and 82°30'07.2" west longitude.
The Site consists of approximately 4.5 acres (Figure 2). The
northern portion of the Site is a pine and deciduous forest,
while the southern"portion is a former field which has been
planted with pine trees. A fence surrounds a 0.6-acre area where
waste was removed from the southern portion of the Site in 1990.
The Site is located on a hill between two (2) small streams. An
unnamed tr~butary leading to Armstrong Creek borders the Site to
the north and east and flows to the east. Another small stream
borders the Site to the south. This stream flows eastward and
discharges into the unnamed tributary to Armstrong Creek about
400 feet east of the Site. Site surface elevations range from
1010 feet above mean sea level (MSL) at the east end of the Site
to 1047 feet above MSL at the west end of the Site.
Within the one-half mile radius of the Site, it is estimated that"
fifty-one percent (51%) is cleared, forty-seven percent (47%) is
forested, and two percent (2%) is surface water. There are four
(4) predominant land use categories. These include single-f~~ily
residence dwellings, agricultural lands (small farms), forest
lands (timber plots), and recreation lands (hunting, fishing, or
unspecified outdoor activities). No schools, hospitals, nursing
homes, or similar institutions are located within this area. The
area's primary water supply source is groundwater obtained from
private wells. A potable water supply pipeline is present in the
vicinity of most of the homes located within one-half mile of the
Site.
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NJ2083
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LEGEND
LOCATION OF FORMER WASTE EXCAVATION
..-..-
STREAM
PROPERTY LINE
SURVEY DATA TAKEN FROM PLAT
PREPARED BY WEBB SURVEYING
& MAPPING GROUP DATED NOV.
1987.
1020
TOPOGRAPHIC CONTOURS IN FEET ABOVE MEAN
SEA LEVEL. CONTOUR INTERVAL IS 2 FEET.
SITE
FIGURE 2
LAYOUT
MAP
81-
585.05
0893
o
I
60
.
SCAlE IN FEET
120
I
ROCHESTER PROPERTY SITE
GREENVILLE COUNTY, SC
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Record of Decision
Rochester Property Site
. Pace 4
2.0
SITE HISTORY AND ENFORCEMENT ACTIVITIES
The Site was used for disposal of wastes which are thought to
include wood glue, print binders, powder materials, natural guar
gums, adhesive for food packages and adhesive restick for
envelopes. The waste materials were placed in four (4) trenches
sometime between late 1971 and early 1972. Each of the trenches
was approximately forty (40) feet long, three (3) feet wide and
ten (10) feet deep.
Previous investigations at the Site began in June 1984 when ~he
South Carolina Department of Health and Environmental Control
(SCDHEC) conducted initial sampling and then subsequently
performed a Site inspection on November 8, 1984. As part of the
inspection, SCDHEC sampled the waste, soils, surface water, and
groundwater in the area. Additional investigations were
performed by Colonial Heights Packaging, Inc.'s, consultant, RMT,
Inc.' (RMT), in August 1987, and February 1988~ and by the.United
States Environmental Protection Agency's (EPA) contractor, NUS
Corporation, in June 1988.
Based on the analysis of the waste collected by EPA and SCDHEC,
EPA ranked the Site and included it on the National Priorities
List Proposed Update in the Federal Register, Vol. 51, No. 111,
on Tuesday, June 10, 1986. The Site was added to the National
Priorities List, pursuant to Section 105 of CERCLA, 42 U.S.C.
~ 9605, on October 4, 1989, with a Hazard Ranking Score of 41.34.
On June 5, 1989, EPA and Colonial Heights Packaging, Inc., signed'
an Administrative Order on Consent, Docket No. 89-09-C, requiring
that Colonial Heights Packaging, Inc., submit a workplan to
characterize the vertical and horizontal extent of affected
media, remove affected materials, and perform sampling to
document the effectiveness of the waste removal. The buried
waste was excavated in January 1990, and disposed of off-site at
a secure hazardous waste landfill.
EPA and Colonial Heights Packaging, Inc., signed another
Administrative Order on Consent, Docket Number 92-04-C, dated
February 19, 1992', to conduct the Remedial Investigation
and Feasibility Study (RIfFS).
The first phase of field work was conducted from July 1992, to
August 1992, and the second phase was conducted in December 1992.
RMT submitted to EPA, on behalf of Colonial Heights Packaging,
Inc., the Final RI Report in April 1993, and the Final FS Report
in May 1993.
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Record of Decision
Rochester Property Site
Paqe 5
3.0
HIGHLIGHTS OF COMMUNITY PARTICIPATION
An information repository, which includes the Administrative.
Record, was established at the Travelers Rest Library in 1992,
and is available to the public at both the information repository
maintained at the Travelers Rest Library, 315 South Main Street,
Travelers Rest, South Carolina, 29690, and at EPA, Region IV
Library, 345 Courtland Street, Atlanta, Georgia, 30365. The
notice of availability of these documents was published in the
Greenville News on June 14, 1993.
A public comment period for the proposed plan was held from .June
14, 1993, to July 14, 1993. A public meeting was held on June
28, 1993, where representatives from EPA answered questions
regarding the Site and the remedial alternatives under.
consideration, which were discussed in the proposed plan. An
extension to the public comment period was requested and granted.
The comment period ended August 13, 1993.
EPA received oral comments during the June 28, 1993, public
meeting, and written comments during the sixty (60) day public
comment period. Responses to the comments received by EPA are
included in the Responsiveness Summary (Appendix A).
This ROD presents EPA's selected remedial action for the Site,
chosen in accordance with CERCLA, as amended by SARA, and to the
extent practicable, the NCP. The remedial action selection for
this Site is based on information contained in the Administrative
Record. The public and state participation requirements under
Section 117 of CERCLA, 42 U.S.C. S 9617, have been met for this
Site.
4.0
SCOPE AND ROLE OF THIS ACTION WITHIN SITE STRATEGY
The purpose of the remedial alternative selected in this ROD is
to reduce potential future risks at this Site. There is no
unacceptable current risk present at the Site. The groundwater
remedial action will remove potential future risks posed by use
of the contaminated groundwater, for potable water supply. This
is the only ROD contemplated for this Site.
5.0
SUMMARY OF SITE CHARACTERISTICS
The RI investigated the nature and extent of contamination on and
near the Site, and defined the potential risks to human health
and the environment posed by the Site. A supporting RI objective
was to characterize the Site-specific geology and hydrogeology.
A total of forty-three (43) soil samples, twenty-nine (29)
groundwater samples, eleven (11) surface water samples, and five
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Record of Decision
Rochester Property Site
Paqe 6
(5) sediment samples were collected during the RI. The main
portion of the RI was conducted from July 1992, to August 1992,
and December 1992. Locations of groundwater, surface soil,
subsurface soil, surface water, and sediment samples are shown in
Figures 3 through 7.
5".1
Meteorology
The Site is located in the Piedmont physiographic province of
South Carolina on the eastern flank of the southern Appalachian
"Mountains. These mountains act to shield this portion of the
Piedmont province from the full effect of cold fronts which move
southeastward'toward this area during the winter months. The
winter season is characterized by temperate or moderate
conditions while the summer months are warm and humid.
During the summer, the temperature rises to 90°F or above on
almost half the days, but usually falls to 70°F or lower during
the night. In the winter, temperatures remain below freezing
through the day on only three (3) to four (4) occasions. Mean
winter temperatures average in the low 30's (oF). Approximately
two (2) to three (3) freezing rain storms and two (2) to three
(3) small snow storms occur each winter. The mean annual
temperature for this area is approximately 60°F.
Precipitation is predominately rainfall and is relatively evenly
distributed throughout the year. The average annual rainfall is
fifty-seven (57) inches per year.
5.2
Geoloqic and Hvdroqeoloqic Settinq
5.2.1 Geoloqy/Soils
The Site is situated in the Piedmont physiographic province of
South Carolina. The Piedmont is a broad plateau ranging from 400
to 1200 feet above sea "level. Piedmont areas are characterized
by low, rounded, gently sloping hills having relatively deeply
incised dendritic drainage patterns. In this area, upland
Piedmont sites typically have a thick layer of highly weathered
residual soil and weathered rock (saprolite) overlying competent
bedrock.
Residual materials generally consist of sandy clays, sandy silts,
silty sands, or silts, and often contain solid rock fragments.
The contact between the saprolite and bedrock typically is
gradational and is often characterized by a zone of fractured
rock material. Saprolite soils often retain the fabric of the
original parent rock and may have preferentially fractured zones
similar to competent rock. The residual soil and saprolite'
thickness in the Piedmont is variable, but may be greater than
eighty (80) feet.
-------
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LEGEND
() SS-1
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SURFACE SOIL SAMPLE POINT LOCATIONS
LOCATION OF FORMER WASTE EXCAVATION
-...-..
- STREAM
---
- PROPERlY LINE
SURVEY DATA TAKEN FROM PLAT PREPARED BY
WEBB SURVEYING c!c MAPPING GROUP DATED
NOV. 1967.
1020
TOPOGRAPHIC CDNTOURS IN FEET ABOVE MEAN
SEA LEVEL. CDNTOUR INTERVAL IS 2 FEET,
FIGURE 3
585.06
0893
SURFACE
o
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SAMPLING
POINTS
18L-
60,
.
SCALE IN
120
I
ROCHESTER PROPERTY SITE
GREENVILLE COUNTY, SC
FEET
-------
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LEGEND'
/
,.--
/
/
./
/
S8-1
o
SOIL BORING LOCATIONS
LOCATION OF FORMER WASTE EXCAVATION
-..-..-
STREAM
PROPERTY LINE
suRVEY DATA TAKEN FROM PLAT PREPARED BV
WEBS SURVEYING & MAPPING GROUP DATED
NOV. 1987.
1020
TOPOGRAPHIC CONTOURS IN FEET A80VE MEAN
SEA LEVEL CONTOUR INTERVAL 15 2 FEET.
585.06
0893
SUBSURFACE
o
I
FIGURE 4
SOIL SAMPLING
POINTS
18l-
60
120
I
ROCHESTER PROPERTY SITE
GREENVILLE COUNTY, SC
SCALE IN FEET
-------
~ /.-...----.-"'" -."" \". "\,\. "'-'" "'" '''', "'"
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LEGEND
MW-1
.
MONITORING WELL LOCATIONS
LOCATION OF FORMER WASTE EXCAVATION
-.--..
- STREAM
PROPERTY LINE
SURVEY DATA TAKEN FROM PLAT
PREPARED BY WEBB SURVEYING
& MAPPING GROUP DATED NOV.
1987.
1020
TOPOGRAPHIC CONTOURS IN FEET ABOVE MEAN
SEA LEVEL. CONTOUR INTERVAL IS 2 FEET.
FIGURE 5
GROUND WATER SAMPLING
POINTS
18l-
585.05
0893
o
I
60
120
I
ROCHESTER PROPERTY SITE
GREENVILLE COUNTY, SC
SCALE IN FEET
-------
~SD-1
f{%llilt1M~~~gtt%%)
J.EG.Et:jD
STREAM SEDIMENT SAMPLE POINT lOCATIONS
lOCATION or rORMER WASTE EKCAV1.TION
. . - STREAM
PROPERTY LINE
- 11120-- ~t~~I7:0~~~U~T:::V~~ ~T~E1.N
.v.~.,."
STREAM
FIGURE 6
SEDIMENT SAMPLING
POINTS
18l-
585.05
0893
1"
SCALE
=
100'
+
STATE PlANE COORDINATES
SUIMY D111A TAI
-------
"-.........,........,,,.-...,,,,,, ...""..,...,w..".......",......"",...,......../ .,"'" .....
"'~'-""""''''''~.........,.
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FIGURE 7
SURFACE WATER SAMPLING
POINTS
81-
o
200
100
585.05
0893
- -
---
SCAlE IN fEET
+
STATE PlNIE COORDINATES
SURVEY DATA TAKEN fROM PlAT PREPARED F1f
WEBB SUIMYING a: MAPPING CROUP DATED
NOV. 1881.
ROCHESTER PROPERTY SITE
GREENVILLE COUNTY. SC
J:\ CAD\ GRAPHIC\ 585\ 585SMF'06.DWG
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Record of Decision
Rochester Property Site
Paqe 12
The Piedmont province is characterized by metamorphic rocks which
have been intruded by igneous rocks. These rocks are
predominately granites, gneisses, schists, and associated
metamorphosed sediments. Rock assemblages may include granite,
mica schist, granite gneiss, gneiss-schist complexes, mica-
granite gneiss, and diabase dikes. Rock composition ranges from
felsic (predominately acid silicates) to mafic (predominat~ly
basic silicates). The top of bedrock surface, at the Site, was
encountered, at depths ranging from 50.2 to 69.5 feet below land
surface. No bedrock outcrops were observed on the Site property
or in the channel ways of the north and south streams, however,
from examinations of saprolite soil samples, the bedrock beneath
the Site is probably a gneiss of granitic origin.
The soils encountered at the Site are formed by the in-place
weathering of the underlying bedrock. The exception is the fill
material encountered in the former waste disposal trenches. Two
(2) categories of undisturbed soil, residual soil, and saprolite,
are present on-site, mantling the bedrock. Residual soils are
the product of a high degree of weathering and thoroughly
decomposed bedrock. Saprolite is weathered decomposed in-place
rock which -is characterized by its retention of the original
fabric or structure of the parent bedrock.
The residual soil thickness encountered in borings ranged from
2.5 to 10.5 feet. These materials were classified as silts,
clayey silts, or silty clays. The observed thickness of the
underlying saprolite ranged from forty-five (45) to sixty (60)
feet. These saprolitic materials were classified as silts except-
near bedrock contacts where silty sands were encountered. The
saprolite present at the Site is typically highly micaceous due
to the nature of the underlying rock from which the saprolite
developed. Sample natural moisture content ranged from 14.1 to
53.5 percent.
5.2.2
Hvdroqeoloqy
Information on the hydrogeology of the Site was obtained from the
thirteen (13) monitoring wells installed during the RI. Ground-
water at-the Site is first encountered in the unconsolidated soil
zones overlying bedrock. The water table was encountered at
depths ranging from approximately 5.5 feet below surface grade to
approximately twenty-three (23) feet below surface grade. The
direction of groundwater flow within the saprolite aquifer is to
the east-northeast towards the north stream segment where it
likely discharges. Water level measurements collected from top
of rock wells show that these wells are screened in an unconfined
aquifer and that the deeper portion of this water table aquifer
also flows toward the northeast. The horizontal hydraulic
gradient is approximately 0.028 feet per foot. Aquifer tests
show the horizontal hydraulic conductivity (k) of the surficial
aquifer is in t~e 10-4 cm/sec range. The range of test values
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Record of Decision
Rochester Property Site
Paqe 13
was from 2.8 x 10-3 em/see (or 7.8 feet/day) to 4.7 X 10-5 em/see
(or 0.1 feet/day). The geometric mean of hydraulic conductivity
values of water table wells was 5.9 X 10-4 em/see
(or 1.7 feet/day). The geometric mean of hydraulic conductivity
values of top of bedrock wells was 1.4 x 10-4 em/see (or 0.4
feet/day). The geometric mean of. hydraulic conductivity values
of all Site wells was 3.4 x 10-4 em/see (or 0.9 feet/day).
Vertical hydraulic conductivity results for representative
aquifer soil samples, as determined from laboratory falling head
tests on Shelby tube samples, range from 4.5 x 10-4 em/see, to
1.7 x 10-6 em/sec. The geometric mean of laboratory determined
vertical permeability value of representative aquifer samples was
8.2 x 10-5 em/see (or 0.2 feet/day). There is apparently little
variation in this aquifer's permeability in the vertical
(0.9 feet/day) and horizontal (0.2 feet/day) directions.
The surficial aquifer's estimated average horizontal velocity is
0.10 feet per day or approximately thirty-nine (39) feet per year
(assuming an effective porosity of 0.25 percent). More
conservatively, if the aquifer's groundwater flow is calculated
using 0.42 percent (the average of all silts) as an estimate of
porosity, the horizontal velocity is 0.06 feet per day or
approximately twenty (23) feet per year. This range of values is
consistent with the range of velocities expected in silty
saprolitic aquifers.
5.3
Nature and Extent of Contamination
Environmental contamination at the Site can be summarized as
follows:
Groundwater Contamination. Seven (7) monitoring wells were
installed during the first phase of field work and were sampled
twice and analyzed for all TCL/TAL parameters. Six (6)
additional wells were installed during the second phase of field
work. All thirteen (13) wells were then sampled and analyzed for
all TCL/TAL parameters except pesticides. Three (3) contaminants
of concern (COCS), trichloroethene (TCE), bis(2-ethylhexyl) .
phthalate, and manganese, were detected in the groundwater in the
saprolite aquifer.
Levels of the TCE ranged from the detection limit (normally 0.010
mg/l), to 0.180 mg/l. TCE concentrations exceeded the Maximum
Contaminant Level (MCL) for this contaminant in three (3) of the
thirteen (13) wells. .
Bis(2-ethylhexyl)phthalate was detected in two (2) wells during
the first sampling event; 0.033 mg/l (though the duplicate was
0.013 mg/l) in one well, and 0.013 mg/l in the other well.
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Record of Decision
Rochester Property Site
Paqe 14
During the second sampling event, bis(2-ethylhexyl)phthalate was
detected in only one of these wells at 0.009 mg/l. It was not
detected in any wells during the third sampling event, and was
detected in the blanks for all the sampling events. The levels
detected in the blanks for the first sampling round was .0005
mg/l in the method blanks, up to .OOB mg/l in the field blanks,
and .033 mg/l in the rinsate blanks. Bis(2-ethylhexyl)phthalate
was found at .0004 mg/l in the method blank during the
second round of sampling, but was not detected in the field or
rinsate blanks. The MCL for bis(2-ethylhexyl)phthalate is 0.006
mg/l.
Manganese levels ranged from the detection limit to 1.39 mg/l,
and exceeded the risk-based criterion (.lBO mg/l), derived in the
Baseline Risk Assessment, in five (5) of the thirteen (13) wells.
Surface Water Contamination. Samples from the unnamed creek,
northeast of the Site, showed levels of TCE at 0.016 mg/l at one
location and 0.005 mg/l at a second location. Extremely low
levels of seven (7) other volatile organic compounds (VOCs),
below 0.005 mg/l, were detected. The TCE value is below the
Ambient Water Quality Criteria of 21.9 mg/l. Inorganic
parameters that were detected were within background ranges.
Soil and Sediment Contamination. Insignificant levels of various
substances were detected in the soil and sediment samples. The
levels detected did not exceed background levels for the
inorganics and were primarily below 0.5 mg/l for the organics.
6.0
SUMMARY OF SITE RISKS
A Baseline Risk Assessment was conducted to evaluate the risks
present at the Site to human health and the environment, under
present day conditions and under assumed future use conditions.
The purpose of a Baseline Risk Assessment is to provide a basis
for taking action and to identify the contaminants and the
exposure pathways that need to be addressed by the remedial
action. It serves as an indication of the risks posed by the
Site if no action were to be taken.
This section of the ROD contains a brief summary of the results
of the Bas~line Risk Assessment conducted for the Site.
Currently, there is no one living on the Site, and only a few
persons residing close to the Site. There are potable water
supply wells within one-half mile of the Site, however, there is
also municipal water available. Future land use will likely.
remain residential, with the potential for-future resident use of
groundwater as a potable water source.
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Record of Decision
Rochester Property Site
Paqe 15
Carcinogenic risk and noncarcinogenic Hazard Index (HI) ratios
were calculated for both the current land use scenario, with
residents near the Site, and the anticipated future land use
scenario, which is residential use. The Baseline Risk Assessment
determined that the total cancer risk (using Reasonable Maximum
. Exposure) for the current. residential scenario is less than
1 x 1.0-6. Therefore, the Site does not pose an unacceptable
cancer risk under the current exposure scenario. The total
Hazard Index for the current resident is 0.038. This hazard
index is well below any level of concern for noncarcinogens (1.0)
and indicates the Site does not pose an unacceptable non-
carcinogenic risk under the current exposure scenario evaluated
in the Baseline Risk Assessment. Therefore, there is no
unacceptable. current risk at the Rochester Property Site.
The Baseline Risk Assessment also determined that the total
cancer risk for the future Site residential scenario was
6.8 x 10-5. This risk level is within the EPA acceptable risk
range (1 x 10 -4 to 1 X 10-6). However, EPA may decide that a
baseline risk level less than 10-4 ( Le., a risk between 10~4 and
10-6) is unacceptable due to site-specific conditions and that
remedial action is warranted. For the Site, EPA believes that a
Remedial Action is warranted, since the future land use will
probably be residential, and MCLs were exceeded for the organic
contaminants. The Hazard Index for the future Site residential
scenario was 8.9 for an adult; this level exceeds the acceptable
hazard index of 1.0. The .non-carcinogenic risk is attributable
to the ingestion of the manganese present in the groundwater.
No substantial risk to wildlife or the environment was found to
exist under present or future conditions.
The Baseline Risk Assessment concluded that the surface soils,
the surface water, and the sediments at the Site are not media of
concern. During the FS, it was determined that the subsurface
soil was not a media of concern. The Baseline Risk Assessment
determined that the groundwater was the only media posing an
unacceptable level of risk to human health or the environment.
The actual or threatened releases of hazardous substances from
this Site, if not addressed by implementing the response action
selected in this Record of Decision, may present an imminent and
substantial endangerment to public welfare or the environme~t.
6.1
Contaminants of Concern
Data collected during the RI were evaluated in the Baseline Risk
Assessment. Contaminants were not included in the Baseline Risk
Assessment evaluation if any of the following criteria applied:
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Record of Decision
Rochester Property Site
Paqe 16
*
If an inorganic compound or element, it was not
detected at or above twice the background
concentration.
*
If an inorganic compound or element, it was detected at
low concentrations, had very low toxicity, and was
judged to be naturally occurring.
*
The data included analytical results flagged as "N"
(presumptive evidence) or "R" (not usable).
The results of the Baseline Risk Assessment concluded that the
only media of concern was the groundwater, and that the
contaminants of concern were trichloroethene (TCE),
bis(2-ethylhexyl)phthalate, and manganese. Levels of the TCE
ranged from nondetect (the detection limit was normally 0.010
mg/l), to 0.180 mg/l. Bis(2-ethylhexyl)phthalate levels ranged
from nondetect to 0.033 mg/l. Manganese levels ranged from
nondetect to 1.39 mg/l.
For each contaminant of concern, exposure point concentrations
were determined in the Baseline Risk Assessment. The upper
ninety-five percent (95%) confidence limit of the arithmetic
means of all detections was used, unless it exceeded the maximum
detected concentration. If this occurred then the maximum. .
detected concentration was used. The exposure point
concentrations calculated in the Baseline Risk Assessment were
0.050 mg/l for TCE, 0.033mg/1 for bis(2-ethylhexyl)phthalate, and'
1.39 mg/l for manganese.
-
6.2
Exposure Assessment
The Site is located in a residential area that is expected to
remain as such, though currently there is no on-site resident.
There are potable wells within a half-mile radius of the Site,
however municipal water is available. Based on this information,
the Baseline Risk Assessment determined that there was only one
reasonable exposure pathway, the ingestion of the contaminated
groundwater.
The Baseline Risk Assessment also determined that the only
population that could potentially be exposed to Site contaminants
would be a potential future on-site resident, and only if the
resident installed a private well. It was determined that there
was no current exposure pathway or current exposed population.
. '
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Record of Decision
Rochester Property Site
Paqe 17
For exposure to the cqntaminants by a resident, it was assumed
that the resident would ingest two (2) liters per day of .
groundwater for 350 days a year for a thirty (30) year period.
It was assumed that a child would be exposed for the same time
period, but would only consume 1 liter per day of water.
6.3
Toxicitv Assessment of Contaminants
The purpose of the toxicity assessment is to assign toxicity
values (criteria) to each chemical evaluated in the Baseline Risk
Assessment. The toxicity values are used in combination with the
estimated doses to which a human could be exposed (as discussed
in the Risk Characterization subsection of the Baseline Risk
Assessment) to evaluate the potential human health risks
associated with each contaminant. Human health criteria
developed by EPA (cancer slope factors and non-cancer reference
doses) were preferentially obtained from the Integrated Risk
Information System (IRIS, 1993) or the 1992 Health Effects
Assessment Summary Tables (HEAST; EPA, 1992). In some cases the
Environmental Criteria Assessment Office (ECAO, 1992) was .
contacted to obtain criteria for chemicals which were not listed
in IRIS or HEAST.
Slope fac~ors (SF) have been developed by EPA for.estimating
excess lifetime cancer risks associated with exposure to
potentially carcinogenic contaminants of concern. SFs, which are
expressed as risk per milligram per kilogram of dose, are.
multiplied by the estimated intake of a potential carcinogen, in
mg/kg-day, to provide an upper-bound estimate of the excess
lifetime cancer risk associated with exposure at that intake
level.
The term "upper bound" reflects the conservative estimate of the
risks calculated from the SF. Use of this approach makes
underestimation of the actual cancer risk highly unlikely. Slope
factors are derived from the results of human epidemiological
studies or chromic animal bioassay data to which mathematical
extrapolation from high to low dose, and from animal to human
dose, has been applied, and statistics to account for uncertainty
have been applied (e.g. to accpunt for the use of animal data to
predict effects on humans).
Reference doses (RfDS) have been developed by EPA for indicating
the potential for adverse health effects from exposure to the
chemicals of concern exhibiting noncarcinogenic effects. RfDs,
which are expressed in units of mg/kg-day, are estimates of daily
exposure levels for humans, including sensitive subpopulations,
that are likely to be without risk of adverse effect. Estimated
intakes of contaminants of concern from environmental media (e.g.
the amount of a chemicals of concern ingested from contaminated
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Record of Decision
Rochester Property Site
Paqe 18
drinking water) can be compared to the RfD.
from human epidemiological studies to which
have been applied (e.g., to account for the
predict effects on humans).
RfDs are derived
uncertainty factors
use of animal data to
Carcinogenic contaminants are classified according to EPA's
weight-of-evidence system. This classification scheme is
summarized below:
Group A:
Known human carcinogen.
Group Bl:
Probable human carcinogen, based on limited human
epidemiological evidence.
Group B2:
probable human carcinogen, based on inadequate
human epidemiological evidence but sufficient
evidence of. carcinogenicity in animals.
Group C:
Possible human c.arcinogen, limited evidence of
carcinogenicity in. animals.
Group D:
Not classifiable due to insufficient data.
Group E:
Not a human carcinogen, based on adequate
animal studies and/or human epidemiological
evidence.
Both TCE and bis(2-et~ylhexyl)phthalate are classified as B2
carcinogens. The slope factor used for TCE was 1.10E-02 (the
reference used was ECAO, 1992) and the slope factor used for
bis(2-ethylhexyl)phthalate was 1.40E-02 (IRIS, 1993). Manganese
is a noncarcinogen that potentially could affect the central
nervous system. The reference dose used for manganese was
5.00E-03 (IRIS, 1993).
6.4
Risk Characterization
The final step of the Baseline Risk Assessment, the generation of
numerical estimates of risk, was accomplished by integrating the
exposure and toxicity information.
For a carcinogen, risks are estimated as the incremental
probability of an individual. developing cancer over a life-time
as a result of exposure to the carcinogen. Excess life-time
cancer risk is calculated from the following equation:
Risk = CDI x SF
where:
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Record of Decision
Rochester Property Site
Paqe 19
Risk = a unitless probability (e.g. 2 x 10-5) of an
individual" developing cancer,
CDI = chronic daily intake averaged over seventy (70)
years (mg/kg-day), and
SF =
slope-factor, expressed as (mg/kg-day)-l
These risks are probabilities that are generally expressed in
scientific notation (e.g. 1 x 10-6). An excess lifetime cancer
risk of 1 x 10-6 indicates that, as a reasonable. maximum
estimate, an individual has a 1 in 1,000,000 chance of developing
cancer as a result of site-related exposure to a carcinogen over
a seventy (70) year lifetime under the specific exposure
conditions at a Site.
The potential for noncarcinogenic effects is evaluated by
comparing an exposure level over a specified time period (e.g.,
life-time) with a reference dose derived for a similar exposure
period. The ratio of exposure to toxicity is called a hazard
quotient (HQ). An HQ less than 1 indicates that a receptor's
dose of a single contaminant is less than the RfD, and that 4he
toxic noncarcinogenic effects from that chemical are unlikely.
By adding the HQs for all chemical(s) of concern that affect the
same target organ (e.g. liver) within a medium or across all
media to which a given population may reasonably be exposed, the
Hazard Index (HI) is generated. An HI less than 1 indicates'
that, based on the sum of all HQs from different contaminants
and exposure routes, toxic noncarcinogenic effects from all
contaminants are unlikely.
The HQ is calculated as follows:
Non-cancer HQ = CDI/RfD
where:
CDI = Chronic Daily Intake
RfD = reference dose; and
CDI and RfD are expressed in the same units and represent the
same period (i.e., chronic, subchronic, or short-term).
It was determined in the Baseline Risk Assessment that there is
no current unacceptable carcinogen or noncarcinogen risk at the
Site. .
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Record of Decision
Rochester Property Site
Paqe 20
Under the future use scenario, the lifetime carcinogenic risk is
'estimated to be 6.8 X 10-5. The estimated lifetime carcinogenic
risk is due to the potential ingestion of organic contaminants in
the groundwater, primarily TCE, 1.3 x 10-5, as well as,
bis(2-ethylhexyl)phthalate, 6.9 x 10-6. Though not contaminants
of concern, (all were detected below 0.004 mg/l) , the following
chemicals contributed to the derived carcinogenic risk number:
benzene (3.45 X 10-6), chloroform (6.44 X 10-6),
bromodichloromethane (3.69 x 10-6), and beryllium (3.45 x 10-5).
Under the future use scenario, the lifetime noncarcinogenic risk,
is estimated to be HI = 8.9. The risk is due to the potential
ingestion of inorganic contaminants in the groundwater, primarily
manganese (HQ = 7.74), as, well as TCE (HQ = 0.454). ~so
included in the derived number, though not a COC, is
Butylbenzlphthalate, HQ = 0.235.
The 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.
7.0
DESCRIPTION OF GROUNDWATER REMEDIAL ALTERNATIVES
The FS considered a wide variety of general response actions and
technologies for remediating groundwater. No other media at the
Site require remedial action. Table 1 summarizes these response
actions and technologies, and provides the rationale for why each'
was retained or rejected for further consideration in the
development of remedial alternatives.
Based on the FS, Baseline Risk Assessment, and Applicable or
Relevant and Appropriate Requirements (ARARs), the remedial
action objectives (RAOs) listed below were established for the
Site. Alternatives were developed with the goal of attaining
these objectives:
.
Reduce to acceptable levels the excess risk to humans
and environmental receptors associated with the media
and contaminants of concern at the Site. This will be
accomplished by reduction in the concentrations of
contaminants that result in excess risk to human health
and the environment. .
.
Reduce the potential to ingest groundwater from the.
Site containing:
-------
TABLE 1
SCREENING OF REMEDIAL TECHNOLOGIES
ROCHESTER FEASIBILITY STUDY
iilill:II~I~lill\'illlllill 1IIIIIIIIIIIIillllllllll~\'IIIIIII~1111111111111 :llilllllllllll~llllllllllllllilllll illilllllilll.llllillllilllllilllllllllllj!lllllllilllIlillllllllllilllllllllllllllllll:lllll: :1:lli!llllllillllllIIIIIIIIIIIII11illll!lllllltlllilllilllllllllll~1Iil[IIIIIIIII!III! Illilllllllj'llli\!lillllilllllllli
No Action Monitoring Sampling Useful means of documenting Technically implementable. Low capital ,
characteristics of ground moderate O&M
water, but does not alter
ground water contamination.
Institutional Action Access Deed Restrictions Dependent upon continued Requires legal assistance for Low capital and
Restrictions implementation in the future. development of specific O&M
Does not affect ground water components and legal authority
contamination. for ensurance of
implementation.
¥{.m!rirt&~ntWm Effective means of preventing Technically imple mentable. Not Moderate capital,
exposure to ground water. necessary due to lack of moderate O&M
affected private wells.
~!!fttij~tft:!.Mt~t~t Mqhi.g!(;W4tW~!gt Effective means of preventi ng Technically imp Ie mentable. Not Moderate to high
~qP'P'1Y $.ppp!y exposure to ground water. necessary due to lack of capital, low O&M
affected private wells. Requires
approval by local utility
authority.
Containment Mfttl@~r::~~ttl~r~ :~'yt!MWV~\@ Effective in containing ground Depth to bedrock is too great to Moderate to high
water flow. be implemented at site.
$.;h~~lH;U~~ Effective in containing ground Depth to bedrock is too great to Moderate to high
water flow. be implemented at site.
!qI~m~~::i$grft@:tl~ Effective in containing ground Depth to bedrock is too great to Moderate to I)igh
water flow. be implemented at site.
@tg.g!%~y'g~!.h Effective in containing ground Depth to bedrock is too Moderate to high
, water flow. great to be implemented at
site
Removal Extraction Extraction Wells 'Effectiveness is dependent on Implementable and typically Moderate capital,
aquifer 'characteristics. acceptable to regulatory low O&M
agencies.
1:\WP\S\S8S0STB.l&2/cdf93
@:qt~MM = Process options:wil/ not be considered further.
-------
TABLE 1 (Continued)
SCREENING OF REMEDIAL TECHNOLOGIES
ROCHESTER FEASIBILITY STUDY
Removal
(Continued)
Treatment
Extraction
(Continued)
Biological
Treatment
Physical Chemical
I:\WP\S\S8S0STB.l&2/cdf9J
@q!19£f.g~m:mtM9.ti.
I?i!tpij
:$!Q~~gr{t~~\!gQ
In-Situ
Biodegradation
Air Stripping
In-Situ Air
Sparging
Carbon Adsorption
~Qij:mIg~!:':m*ig~W?:q
Chemical
Precipitation
through aeration
Effectiveness is dependent on
aquifer characteristics.
Potentially effective for
removal of organics. Bench
testing required to determine
effectiveness.
Potentially effective for
removal of organics.
Increased oxygen may reduce
dissolved manganese.
Effective for treatment of
VOCs.
Effective for treatment of
organic compounds and
manganese. Will serve as
oxygen supply to enhance
biological degradation.
Effective on most dissolved
organics
Effective for degradation of
organic wastes. Will aid
precipitation of manganese.
Effective for removal of
metals, including manganese.
Depth to bedrock is too great to
be implemented at site.
Not technically implementable
due to low concentration of
organic contaminants.
Technically implementable as a
component of alternative
Can be implemented in
conjunction with other
technologies.
Technically implementable
Can be implemented in
conjunction with other
technologies.
Presence of manganese would
require pretreatment to prevent
fouling of UV lamps.
Can be implemented in
conjunction with other
technologies.
~~tMt@tj = Process options- will not be considered further.
Moderate to low
capital, low O&M
Moderate to high
capital and O&M
Moderate capital
and O&M
Low capital,
moderate O&M
Low capital,
moderate O&M
High capital,
moderate to high
O&M.
Moderate to high
capital and O&M.
Not cost effective.
High capital and
moderate to high
O&M.
-------
TABLE 1 (Continued)
SCREENING OF REMEDIAL TECHNOLOGIES
ROCHESTER FEASIBILITY STUDY
Treatment
(Continued)
Physical Chemical
(Continued)
I:\WP\S\S8S0STB.l&2/cdf93
Filtration
@t~~M$~n~:lfmgt
:!9n:::ggijMJ!Mgg
:fH~¥gt~~t:g~OO!1~i.~
Effective for removal of
precipitated metals, including
manganese.
Effective for removal of iron
and manganese.
Effective for removal of
metals, including manganese.
Can effectively concentrate
inorganic contaminants of
concern. TCE and BEHP
could cause loading problems.
~9.t~:M~:<:! = Process options will not be considered further.
Can be implemented in
conjunction with other
technologies.
Can be implemented in
conjunction with other
technologies.
Moderate to high
capital and O&M
Moderate to high
capital and O&M
Not cost effective
for small mass
loading of
manganese
expected.
Moderate to high
capital and O&M
Not cost effective
for small mass
loading of
manganese
expected.
Can be implemented in
conjunction with other
technologies
Can be implemented in
conjunction with other
technologies.
Moderate to high
capital and O&M
Not cost effective
for small mass
loading of
manganese
expected.
-------
TABLE 1 (Continued)
SCREENING OF REMEDIAL TECHNOLOGIES
ROCHESTER FEASIBILITY STUDY
i~!/I"II!li\'I!1111~~ 11~~i~III~;.III~llillil!IIIIII~'1 ""..........- "",........."""""""", ill!III!III,I!'!llli'i!I!I!!!~I!III!!i!!III~III~111111Ilill!I!!IIIII'!!!!I!I!!!!III!i!I!I!I!!! !i!illl!llli!lllil,li!!~lllllllli!IIIIIIIIIIIII~I,1111111'II'I!!ill!ii!II/!!II'!'III! /illilil/llllllililllllll!I'!lilll'/
:~::::::::~[[[~:::::::::
,',',',','."',','.',',',',',',',',',',',',',','.',',',',"','."',',',',',',',',',',',',',',','."'.',
i::::!i:,!III~ilillllll':,I::::1
Disposal On-Site Disposal Local St ream Effective and reli able May requi res N P DES discharge Low capital , very
discharge method. permit (if off-site) low O&M
Infiltration Rate of i nfi It ratio n Ii mited in Tech nically i mpleme ntable Moderate capital,
soi Is with low hydrau lic low to very low
conductivities. O&M
Off-Site Disposal :!1QIDYt Effective and reli able Sewer not locally avai lable Low capital , high
discharge method. Waste must be h auled to O&M
POTW.
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Record of Decision
Rochester Property Site
Paqe 25
Carcinogen concentrations above Federal or State
standards, or in. the absence of standards, above
levels that would. exceed an acceptable cancer risk
range of 10-4 to 10-6 (unless the risk manager
decides that a risk level less than 10-4 (i.e., a
risk between 10-4 and 10-6) is unacceptable due to
site-specific conditions);
Noncarcinogen concentrations above Federal or
State standards, or in the absence of standards,
above levels that would exceed an acceptable
Hazard Index (HI) of 1.0.
Technologies considered potentially applicable to groundwater
contamination (Table 1, Section 7.0 above) were further evaluated
on effectiveness and implementability. Listed below are those
alternatives which passed this final screening, and are proposed
for groundwater remediation.
The remedial alternatives are listed below. The last
groundwater alternative is a set (tlAtI and tlBtI), Alternative 4A
and 4B differ only in which option is used for discharging
treated groundwater.
Alternative 1:
No Action
Alternative 2:
Instit~tional Controls and Access Restrictions
Alternative 3:
In-Situ Air Sparging
Alternative 4A: Groundwater Recovery with Air Stripping,
Filtration, and Carbon Adsorption, with Surface
Water Discharge
Alternative 4B: Groundwater Recovery. with Air Stripping,
Filtration, and Carbon Adsorption, with
Discharge to Infiltration Trenches
Each of the five (5) alternatives is discussed below.
Alternative 1 will not meet the remediation goals presented in
Section 9.1.3 of this ROD. Alternative 2 should meet the
remediation goals through natural attenuation. Alternatives 3,
4A, and 4B will meet the remediation goals through treatment.
"O&M costs" refer to the costs of operating and maintaining the
treatment described in the alternative, for an assumed period of
ten (10) years, and/or monitoring the groundwater for an assumed
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Record of Decision
Rochester Property Site
Paqe 26
period of thirty (30) years. All of the five (5) alternatives
have anticipated O&M costs. O&M costs were calculated using a
five percent (5%) discount rate per year.
The components of Alternative 2, institutional controls and
groundwater monitoring, are included for all alternatives except
Alternative 1, the "no action" alternative, which would not have
the access restrictions and/or deed restrictions.
Certain ARARs (see Section 9) are applicable, or relevant and
appropriate, to each of'the groundwater remedial alternatives.
Site groundwater is classified by South Carolina as Class GB (SC
Water Classifications and Standards, Regulation 61-68), and by
EPA as Class IIA (Guidelines for Ground Water Use and
Classification, EPA Ground Water Protection Strategy, US EPA
1986) .
Alternative 1 would not meet the relevant and appropriate ARARs,
identified in Section 9, concerning groundwater as a potable
water source. These are the National Primary and 'Secondary
Drinking Water Standards, promulgated in 40 C.F.R. Parts 141-143,
and the State of South Carolina Primary Drinking Water
Regulations, SC Reg. 61-58. These ARARs would not be met because
Site groundwater violates MCLs specified in these regulations.
In addition, the CERCLA preference for treatment to reduce the
toxicity, mobility, or volume of the contaminants, wherever
possible, would not be satisfied by Alternatives 1 or 2.
Alternative 2 would not meet the CERCLA preference for treatment.
Assuming successful implementation, however, it would meet the
relevant and appropriate drinking water standards specified
above, albeit at a very slow rate. The remaining alternatives,
3, 4A, and 4B, would achieve these standards, arid would also meet
the CERCLA preference for treatment.
Alternatives 3, 4A, and 4B, would be subject to the following
applicable, or r~levant and appropriate requirements (ARARs) or
criteria to be considered (TBCs): National Ambient Air Quality
Standards (NAAQS), 40 C.F.R. Part 50; National Emissions
Standards for Hazardous Air Pollutants (NESHAPs), 40 C.P.R. Part
61, TBC; South Carolina Ambient Air Quality Standards (SC Reg
R61-62); and South Carolina Well Standards and Regulations, (R61-
71) .
Other,ARARs for Alternatives 4A and 4B include the Clean Water
Act Pretreatment Standards (40 C.F.R. Parts 122, 125, 129, 133,
and 136), and depending on the disposal option, South Carolina
NPDES Discharge L.imitations for treated water (R61-9) if
discharge is to a stream and South Carolina No Discharge
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Record of Decision
Rochester Property Site
Paqe 27
Permit Requirements for treated waters (R61) for discharge to
infiltration trenches.
The treatment system related to Alternatives 4A and 4B, may
produce a sludge, and possibly spent carbon, that may be subject
to the identification (40 C.F.R. Part 261, SCHWMR 61-79.261),
transportation (40 C.F."R. Part 262, SCHWMR 61-79.262), "
manifestation (40 C.f.R. Part 263, SCHWMR 61-79.263), and land
disposal restriction (40 C.F.R. Part 26B, SCHWMR 61-79.268)
requirements of the Resource Conservation and Recovery Act (RCRA)
42 U.S.C. SS 6901 et seg., as amended, if the resulting sludge is
determined to be a RCRA hazardous waste.
7.1
Alternative 1:
No Action
Under the no action alternative, the Site is left "as is" and no
funds are expended for the cleanup or .control of the contaminated
groundwater. Monitoring of contaminants of concern and their
degradation contaminants, not including their innocuous
compounds, would be included as part of this alternative.
Monitoring of the contaminants would involve the collection and
analysis at regular iptervals, of groundwater samples from
existing Site monitoring wells, as well as surface water samples
from previous creek locations, to allow tracking of contaminant
concentrations and to monitor the speed, direction, and extent of
contaminant migration. The number and location of well and
surface water samples will be determined during remedial design.
In addition, the need for any additional monitoring wells, which
may be sampled for additional contaminants, will be determined
during the remedial design/remedial action phases. These wells
may be added if it is determined later that groundwater
contamination has left the Site property or if further
characterization of the Site is needed. Future risks to persons
living on and near the Site will remain. Because hazardous.
contaminants would remain on-site, a Five (5) Year Review would
be required under CERCLA.
Capital Cost:
Annual O&M Cost:
Total Present Worth Cost:
27,000.00
116,800.00
$ 1,925,000.00
$
7.2
Alternative 2: Institutional Controls and Access
Restrictions
Under this alternative, institutional controls would be
implemented to restrict the withdrawal and use of contaminated
groundwater on-site. A second requirement of this alternative
will be the monitoring of contaminants, as described in
Alternative 1.
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Record of Decision
Rochester Property Site
Paqe 28
The institutional controls would apply to the Rochester Property
Site, and include deed restrictions and well permit restrictions.
Deed restrictions would prevent future use of the contaminated
groundwater for purposes such as potable water supply or
irrigation. These restrictions" would be written into the
property deed to inform future property owners of the possibility
of contaminated groundwater beneath the property. Permit
restrictions, issued by the State of South Carolina, would
restrict all well drilling permits issued for new wells on the
Site property that may draw water from the contaminated
groundwater.
Capital Cost:
Annual O&M Cost:
Total Present Worth Cost:
40,000.00
116,800.00
$ 1,938,000.00
$
7.3
Alternative 3: In-Situ Air Sparqinq
In-situ air sparging would be accomplished by pumping air through
gravel-filled trenches, and if required by EPA, wells, in the
saturated zone, creating a steady flow of gas, or bubbles, that
rise through the aquifer. Air sparging creates a crude form of
an air stripper in the subsurface. The rising bubbles contact
the dissolved contaminants and allow the TCE to volatilize. In
addition to stripping the TCE, the addition of oxygen to the
groundwater would promote biodegradation of bis(2-ethylhexyl)
phthalate and oxidation of soluble manganese to its more
insoluble form. The insoluble manganese would then precipitate
and be re-deposited in the soils, where it is already naturally
occurring.
At the Site, all TCE contamination has been found in the shallow,
water table wells. Therefore, horizontal air sparging trenches
would be installed at a depth below the water table. In
addition, air sparging wel"ls may also be installed, if it is
determined in the remedial design that the air sparging trenches
will not reduce the inorganic contaminant to below the
performance standard. Following excavation of the trenches,
perforated pipe would be laid horizontally in the trenches, and
the trenches would be backfilled with gravel. The air would"be
sparged below the water table, thus reducing the contaminants of
concern to below the performance standards. The number and
location of trenches required to remediate groundwater will be
determined during remedial design. It is possible that only one
trench will be required. Also, the need for supplemental air
sparging wells to remediate the inorganic contaminant, including
the number and locations, would be determined during remedial"
design.
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Record of Decision
Rochester Property Site
Paqe 29
The vapors would travel through the gravel and through the
topsoil layer (if present) to the land surface. Vent pipes or
other venting system(s) would be placed through the subsurface to
facilitate vapor discharge. The estimated amount of TCE that
would volatilize to the atmosphere is extremely low, about 1.5
pounds per year.
In addition to the treatment processes described above, this
alternative would include implementation of all of the
groundwater monitoring and institutional controls described in
Alternatives land 2, thereby ensuring the effectiveness of the
alternative and limiting future use of groundwater until the
performance standards are continuously achieved.
Capital Cost:
Annual O&M Cost:
Total Present Worth Cost:
$
420,000.00
.156,500.00
$ 2,681,000.00
7.4
Alternatives 4A and 4B: Groundwater Extraction and
Treatment
Alternatives 4A and 4B involve placing extraction wells
throughout the contaminated groundwater to actively remediate the
aquifer. This would also prevent further migration of the
contaminated groundwater. It would involve installing extraction
wells, removing water from the aquifer, and treating extracted
groundwater. The groundwater would be treated to remove
inorganic ~nd organic contaminants. In addition to groundwater
treatment, institutional controls, as described in Alternative 2,
would be implemented to limit current and future use of
groundwater until the performance standards are continuously
achieved. Also, contaminant monitoring would be performed to
monitor the effectiveness of the alternative in achieving the
remediation goals, as described in Alternative 1.
The groundwater would be sequentially treated by air stripping to
remove the TCE and oxidize the manganese, filtered to remove
insoluble manganese, and filtered with activated carbon to remove
the bis(2-ethylhexyl)phthalate. If, during future sampling
events, it is determined that bis(2-ethylhexyl)phthalate is not
present in the groundwater, the carbon filtration portion of the
treatment system would be removed.
An air stripping unit works by fostering a controlled evaporation
or "stripping" process. The unit has a "tower" or vertical
cylinder, filled with a packing media which provides a large
surface area for contact between the water and air. The water to
be treated is pumped to the top of the tower and cascades
downward through the packing media. Air is blown upwards through
-------
Record of Decision
Rochester Property Site
Paqe 30
the bottom of the tower and exits at the top. The high volume of
air passing over the thin film of water on the packing evaporates
(strips) the volatile organic contaminants from the water. In
the process, contaminants are transferred from water to air. The
limited volatile emissions (1.5 "pounds per year) from the air
stripper would not require any additional emissions control
system. After treatment, the groundwater extracted from beneath
the Site could be piped to a local stream (Alternative 4A). This
disposal option may require obtaining, or at least meeting, the
substantive requirements of a National Pollution Discharge
Elimination System (NPDES) permit. Maintenance of the discharge
permit would, at a minimum, require regular effluent monitoring
for TCE, bis(2-ethylhexyl)phthalate, and manganese.
Alternatively, the treated groundwater could be introduced into a
series of reinfiltration trenches (Alternative 4B). These
trenches would each contain a perforated PVC pipe embedded in a
gravel layer and would be analogous to a septic tank leach field.
The length, depth, width, and number of trenches, would be
determined 4uring the Remedial Design phase.
Reinfiltration of the treated groundwater would not require any
discharge permit. However, implementation of this alternative
would require submittal of a Preliminary Engineering Design
Report to the State of South Carolina for approval. In addition,
this disposal option would, at a minimum, require regular .
effluent monitoring for TCE, bis(2-ethylhexyl)phthalate, and
manganese. . .
Preliminary groundwater modeling indicates that three (3) to four'
(4) extraction wells would be needed to recover the contaminated
groundwater at a potential yield of approximately two (2) to
three (3) gallons per minute (gpm) per well. Given the
relatively slow horizontal movement of Site groundwater, this
alternative would take longer to reach the remediation goals than
Alternative 3, because of the time necessary for the contaminated
groundwater to reach the extraction wells. It is estimated to'
.take three (3) to ten (10) years to reach the remediation "goals,
but it could take longer.
Alternative 4A:
Capital Cost:
Annual O&M Cost:
Total Present Worth Cost:
520,000.00
201,300.00
$ 3,071,000.00
$
Alternative 4B:
Capital Cost:
Annual O&M Cost:
Total Present Worth Cost:
567,000.00
197,000.00
$ 3,084,000.00 -
$
-------
Record of Decision
Rochester Property Site
Paae 31
8.0
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES FOR
GROUNDWATER
The five (5) alternatives for groundwater remediation were
evaluated based upon the nine (9) criteria set forth in
4'0 C. F. R. ~ 300.430 (e) (9) of the NCP. In the sections which
follow, brief summaries of how the alternatives were judged
against these nine (9) criteria are presented. In addition, the
sections are prefaced by brief descriptions of the criteria.
8.1
Groundwater Remediation Alternatives
For ease of reference, the five (5) groundwater remedial
alternatives that EPA considered are listed in Table 2.
8.1.1 Threshold Criteria.
Two (2) threshold criteria must be achieved by a remedial
alternative before it can be selected.
1. Overall protection of human health and the environment
addresses whether the alternative will adequately protect human
health and the environment from the risks posed by the Site.
Included is an assessment of how and whether the risks will be
properly eliminated, reduced, .or controlled through treatment,
engineering controls, and/or institutional controls.
All of the alternatives, with the exception of Alternative 1, No
Action, will provide overall protection of human health and the
environment. Alternative 2, Institutional Controls/Natural
Attenuation, achieves protection from the contaminants by
preventing exposure to affected' groundwater by establishing deed
restrictions prohibiting future uses of groundwater under the
Site, and by allowing natural biodegradation to reduce the
.concentrations of organic contaminants in the affected
groundwater. This alternative should also provide protection
from the inorganic contaminants.
Alternative 3, In-Situ Air Spargina, utilizes in-situ sparging
technology to reduce contaminant concentrations in the ground
water and deed restrictions to prohibit future uses of
groundwater during the remedial period.
Alternative 4A, Groundwater Extraction, Treatment, and Discharae
to a Local Stream, and Alternative 4B Groundwater Extraction,
Treatment, and Discharae to Reinfiltration Trenches, will'
likewise achieve overall protection through extraction and
treatment of groundwater.
-------
TABLE 2
COMPARATIVE ANALYSIS OF ALTERNATIVES
ROCHESTER PROPERTY FEASIBILITY STUDY
Description
Criteria
Overall protection 01
human health and
the environment
Compliance with
ARARs
Long-term
effectiveness and
Permanence
Assumes no engineered
controls to prevent migration or
interrupt exposure pathways.
The alternative is considered
complete at this point.
No change in existing
conditions. This alternative is
not protective 01 human health
and the environment.
Does not comply with ARARs
The alternative is considered
complete at this time; therelore
no long term effectiveness has
been achieved. Ground water
monitoring will be effective in
assessing migration 01 affected
ground water.
I:\WP\5\58505TO.l&2/cdf9J
Establish security lencing and
deed restrictions. Allows for
natural attenuation.
This alternative would minimize
exposure to affected ground
water and limit exposure
pathways. Future exposure
concentration available to
receptor could be reduced
through natural attenuation.
Will comply with ARARs lor
organic contaminants in 5-14
years through natural attenuation.
Will be effective in reducing
organic contaminant
concentrations in 5-14 years
through natural attenuation.
Install a air sparging trench to
enhance volatilization and
biodegradation 01 organics and
to Increase oxygen level in
subsurface to aid in the
precipitation 01 manganese.
This alternative would minimize
exposure to affected ground
water and limit exposure
pathways Irom source to
receptors. Future exposure
concentration available to
receptor would be reduced
through enhanced volatilization
and biodegradation 01 COCs.
Will comply with ARARs in 4-5
years through volatilization and
enhanced biological
degradation.
Will be effective in reducing
contaminant concentrations in
4-5 years through volatilization,
enhanced biodegradation, and
aeration 01 the subsurface.
Install recovery wells to contain
and extract affected ground
water. Treat contaminated
ground water and discharge
under an NPDES permit.
This alternative is overall
protective 01 human health and
the environment. This
alternative is as protective lor
organics as Alternative 3, but
more protective lor
inorganics.The short-term risk
is slightly elevated due to
exposure to contaminants
during construction.
Will meet ARARs through
treatment 01 affected ground
water in 3-10 years.
Extraction and treatment will
reduce affected ground water
and be long-term effective.
Containment 01 ground water
can be achieved in 1-3 years.
Treatment will achieve
remediation goals in 3-10
years.
Install recovery wells to
contain and extract
affected ground water.
Treat contaminated ground
water and discharge under
an No Discharge permit.
This alternative is overall
protective 01 human health
and the environment. This
alternative is as protective
lor organics as Alternative
3, but more protective lor
inorganics.The short-term
risk is slightly elevated due
to exposure to
contaminants during
construction.
Will meet ARARs through
treatment 01 affected
ground water in 3-10 years.
Extraction and treatment
will reduce affected ground
water and be long-term
effective. Containment 01
ground water can be
achieved in 1-3 years.
Treatment will achieve
remediation goals in 3-10
years.
-------
TABLE 2 (Continued)
COMPARATIVE ANALYSIS OF ALTERNATIVES
ROCHESTER PROPERTY FEASIBILITY STUDY
............................................ - [[[~[[[ - - .
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............................................
'.",",",',",",".....",",',',',',',',',",',',',',',',',',",',",',',",',",',',',',',',",',
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Itrt~rrrr~~~j~I~tfrtfII~rrr
::::::::::;::::::::::~::::::~::~::::::::::::::::::::~:::?::::~::::::::~::::::::~:
'::::ii::;:::!i!:!:ii!!l~l!!li1!:!:ii!!!!:iii::I:!!ii:i:j\!1~:::\[:::[[~\
liIJI!ill~i!iIIJllllilllllll!:iillllll!lllllllilllllll~illilll!illliilllllill .:.:.:.:.:.:.:.:.:~[[[-:.:.:.:.:.;.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:
Reduction 01 Will not reduce toxicity, mobility Will not reduce toxicity and Will reduce toxicity and volume Treatment will reduce toxicity Treatment will reduce
toxicity, mobility, or or volume. volume through treatment. through volatilization and and volume 01 contaminants. toxicity and volume 01
volume through However, contaminant enhanced degradation in 4-5 Removal of ground water will contaminants. Removal of
treatment concentrations will decrease years. reduce mobility 01 ground water will reduce
through natural attenuation in 5- contaminants mobility 01 contaminants.
1 4 years.
Short-term No effect on the environment or Will provide the greatest Site disturbances are Site disturbances are Site disturbances are
effectiveness on the affected ground. short-term effectiveness, since no manageable. manageable. Mobility in air manageable. Mobility in air
construction activities are environment will be slightly environment will be slightly
involved. increased. increased.
Implementability Readily implementable. Some Equal to Alternative 1 Readily implementable. Design This alternative is readily This alternative is readily
01 the monitoring wells have and installation downtime implementable using existing, implementable using
already been installed. minimal compared to extraction proven technologies. Obtaining existing proven
and discharge alternatives a NP DES permit may be technologies Obtaining a
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Record of Decision
Rochester Property Site
Paqe 34
Future cancer risk through groundwater ingestion will be reduced
to less than 1 x 10-6 through natural attenuation of organic
contaminants in Alternative 2, through volatilization and
enhanced degradation of organic contaminants in Alternative 3,
~nd through extraction and treatment in Alternative 4.
Future noncarcinogenic effects through groundwater ingestion will
be reduced to acceptable levels, through oxidation of manganese
in Alternative 3, and through extraction and treatment in
Alternative 4. Future noncarcinogenic effects through
groundwater ingestion should be reduced to acceptable levels in
Alternative 2. .
2. Compliance with applicable or relevant and appropriate
requirements (1L~s) addresses whether an alternative will meet
all of the requirements of Federal and State environmental laws
and regulations, as well as other laws, and/or justifies a waiver
from an ARAR. The specific ARARs which will govern the selected
remedy are listed and described in Section 9.0, the Selected
Remedy.
The evaluation of the ability of the proposed alternatives to
comply with ARARs included a discussion of chemical-specific and
action-specific ARARs presented in Section 7. As stated earlier,
there are no known location-specific ARARs for the Site. All of
the alternatives, with the exception of Alternative 1, No Action,
will meet their respective ARARs at the completion of the
remedial activities.
8.1.2
Primary Balancinq Criteria
Five (5) criteria were used to weigh the strengths and weaknesses
of the alternatives, and were used to select one of the five (5)
alternatives. Assuming satisfaction of the threshold criteria,
these five (5) criteria are EPA's main considerations in .
selecting an alternative as the remedy.
1. Lona term effectiveness and permanence refers to the ability
of the alternative to maintain reliable protection of human
health and the environment over time, once the remediation goals
have been met. Alternative 1, No Action, will not provide long
term effectiveness. Alternatives .2, Institutional Controls/ .
Natural Attenuation, and Alternative 3, In-Situ Air Sparainq,
achieve permanent reduction in organic contaminants through
biological degradation and volatilization, respectively, after
which the manganese should be reconverted to an insoluble form.
Alternative 3 would increase the oxygen to the subsurface at a
much higher. rate than Alternative 2, thus attaining remediation
levels in a shorter time period.
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Record of Decision
Rochester Property Site
Paae 35
Alternative 2 is projected to result in groundwater
concentrations below remediation goals (MCLS) in five (5) to
fourteen (14) years. Alternative 3, In-Situ Air Spargina, is
projected to result in groundwater concentrations below'
remediation goals (MCLs) in four (4) to five (5) years.
Alternative 4, Groundwater Extraction and Treatment, will utilize
volatilization, filtration and absorption to remove contaminants
from the groundwater, and therefore, be effective in the long-
term.
2. Reduction of toxicity, mobility, or volume throuah treatment
addresses the anticipated performance of the treatment
technologies that. an alternative may employ. The 1986 amendments
to CERCLA, the Superfund Amendments and Reauthorization Act
(SARA), directs that, when possible, EPA should choose a
treatment process that permanently reduces the level of toxicity
of Site contaminants, eliminates or reduces their migration away
from the Site, and/or reduces their volume on a Site.
Alternative I, No Action, does not achieve a reduction in the
toxicity, mobility, or volume of the contaminants since the
alternative is considered complete at this time.
Alternative 2, Institutional Controls/Natural Attenuation, is not..
a treatment technology and, therefore, does not satisfy the
statutory preference for selecting remedial actions that employ
treatment technologies that permanently and significantly reduce
the toxicity, mobility, or volume of the contaminants. However,.'
the organic concentrations will decrease in five (5) to fourteen
(14) years, after which the manganese should be reconverted to an
insoluble form.
Alternatives 3, In-Situ Air Sparaina, and Alternative 4,
Groundwater Extraction and Treatment, use active treatment
technologies to reduce the toxicity, mobility, and volume of the
contaminated groundwater. Reduction of organic contaminant
concentrations in the groundwater can be achieved by Alternative
3 through enhanced biodegradation and in-situ volatilization of
the contaminants in an estimated four (4) to five (5) years.
This alternative is expected to reduce the concentration of
manganese in the groundwater following return of the aquifer to
background conditions through active reoxidation and
precipitation.
Alternative 4, Groundwater Extraction and Treatment, will
likewise achieve a permanent reduction of the concentrations of
contaminants in the groundwater through the above ground
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Record of Decision
Rochester Property Site
Paqe ~6
treatment schemes within an estimated three (3) to ten (10) year
operation period. Containment of the contaminated groundwater
should be achieved in one (1) to three (3) years.
3. Short-term effectiveness refers to the potential for adverse
effects to human health or the environment posed by
implementation of the remedy.
Of the alternatives that achieve ARARs, Alternative 2,
Institutional Controls, affords the greatest level of short-term
protection because it presents the least risk to remedial
workers, the community, and the environment. The other
alternatives could release minimal volatile emissions during
excavation and/or treatment system construction. Standard
construction management techniques should address any potential
short-term fugitive emissions.
Since there is no current risk at the Site posed by direct
contact and/or ingestion of surface soils, the time frame to
achieve short-term protectiveness is shorter for those
alternatives that do not involve invasive techniques. Field
implementation of Alternative 3, In-Situ Air Sparqing, is
expected to take three (3) months. Field implementation of
Alternative 4, Groundwater Extraction and Treatment is expected
to take six (6) months.
4. Implementabilitv considers the technical and administrative
feasibility of an alternative, including the availability of
materials and services necessary for implementation.
Of the alternatives that will comply with ARARs, Alternative 2,
Institutional Controls, will be the easiest to implement since it
does not involve the construction of a treatment system.
The construction technologies required to implement Alternative
3, In-Situ Air Sparainq, are comparable with standard trenching
and well installation activities. The air sparging system has.
additional operational requirements compared to Alternative 2
because of the air supply system.
The construction technologies required to implement Alternative
4, Groundwater. Extraction and Treatment, are well established and
very reliable. The extraction and treatment systems will have
additional operational requirements compared to Alternatives 1,
2, and 3, because of the complexities of a continuous operation
of a groundwater extraction system, the operation of a multi-
component treatment system, and requisite discharge limits on the
resulting treated effluent. The extraction and treatment system
is more difficult to operate and maintain than options proposed
under Alternative 2 and Alternative 3.
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Record of Decision
Rochester Property Site
Paqe 37
The technical implementability of all the evaluated alternatives
.is reasonable. Technologies required to implement the
alternatives are readily available and proven at full-scale in
similar field efforts. Qbtaining discharge permits are a
prerequisite for the implementation of Alternative 4, if
discharge is to the creek.
5. Cost includes both the capital (investment) costs to
implement an alternative, plus the long-term O&M expenditures
applied over a projected period of operation. The total present
worth cost for each of the four alternatives is presented in
Table 3, and in Section 7.
8.1.3
Modifvinq Criteria
State acceptance and community acceptance are two (2) additional
criteria that are considered in selecting a remedy, once public
comment has been received on the Proposed Plan.
1. State acceptance: The State of South Carolina concurs with
this remedy. South Carolina's letter of concurrence is provided
in Appendix B to this ROD.
2. Communitv acceptance was indicated by the verbal comments
. received at the Rochester Property Site Proposed Plan public
meeting, held on June 28, 1993. The public comment period opened
on June 14, 1993, and closed on August 13, 1993 (after a 3D-day
extension). Written comments received concerning the Site, and
those comments expressed at the public meeting, are addressed in .
the Responsiveness Summary attached as Appendix A to this ROD.
9.0
THE SELECTED REMEDY
9.1 Groundwater Remediation
Based upon consideration of the requirements of CERCLA, the NCP,
the detailed analysis of the five (5) alternatives and public and
state comments, EPA has selected a remedy that addresses
groundwater contamination at this Site. At the completion of
this remedy, the risk remaining at this Site will be 1 x 10-6,
and HI less than 1, which is considered protective of human
health and the environment.
The selected remedy for the Site is:
Alternative 3, In-Situ Air Sparging
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Record of Decision
Rochester Property Site
Paqe 38
Total present worth cost of the selected remedy is:
$ 2,681,000.00.
This remedy consists of in-situ air sparging of contaminated
groundwater. The following subsections describe this remedy
component in detail, provide the criteria (ARARs and TBC
material) which shall apply, and establish the performance
standards for implementation.
9.1.1
'Description
This remedy component consists of the design, construction and
operation of an in-situ air sparging system, and development and
implementation of a Site monitoring plan to monitor the system's
performance. The groundwater treatment specified below shall be
continued until the performance standards listed in Section
9.1.3. are achieved, at a minimum, in all of the monitoring wells
that are associated with the Site.
In-situ air sparging will be accomplished by pumping air, through
trenches and, possibly wells, in the saturated zone, creattng a
steady flow of gas, or bubbles, that rise through the aquifer.
The rising bubbles contact the dissolved contaminants and allow
the TCE to volatilize.' In addition to stripping the TCE, the
addition of air (containing oxygen) to the groundwater will
promote biodegradation of bis(2-ethylhexyl)phthalate and
oxidation of soluble manganese to it~ more insoluble form. The
inspluble manganese will then precipitate and be re-deposited in
the soils, where it is already naturally occurring. Treatability
studies (bench and/or pilot) will be conducted, if determined to
be necessary during ~emedial Design.
Horizontal air sparging trenches (and possibly wells) would be
installed at a depth below the water table. The vertical extent
of groundwater contamination will be confirmed and updated during
the Remedial Design. Following excavation of the trenches,
perforated pipe would be laid horizontally in the trenches, and
the trenches would be backfilled with gravel. The air would be
sparged below the water table, thus reducing the contaminants of
concern to below the performance standards. The number and
location of trenches required to remediate groundwater will be
determined during remedial design. It is possible that only one
trench will be required. Also the need for supplemental air
sparging wells to remediate the inorganic contaminant, including
the number and locations, will be determined_during remedial
design.
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Record of Decision
Rochester Property Site
Paqe 39
The vapors would travel through the gravel and through the
topsoil layer (if present) to the land surface. Vent pipes or
other venting system(s) will be placed through the subsurface to
facilitate vapor discharge. The estimated amount of TCE that
would volatilize to the atmosphere is extremely low, about 1.5
pounds per year.
In addition to the treatment processes described above, this
alternative will include implementation of all of the
institutional controls and contaminant monitoring requirements
described in Alternatives 1 and 2, thereby monitoring the
effectiveness of the alternative and limiting future use of
groundwater until clean-up goals are achieved.
The institutional controls would apply to the Rochester Property
Site, and include deed restrictions and well permit restrictions.
Deed restrictions would prevent future use of the contaminated
groundwater for purposes such as potable water supply or
irrigation. " These restrictions would be written into the
property deed to inform future property owners of the possibility
of contaminated groundwater beneath the property. Permit
restrictions, issued by the State of South Carolina, would
restrict all well drilling permits issued for new wells on the
Site property that may draw water from the contaminated
groundwater. Institutional controls will also include a fence,
or other suitable method subject to EPA approval, surrounding the
previous disposal trenches and all in-situ air sparging
operations, including the trenches, wells, and equipment.
Monitoring of contaminants of concern and their degradation
contaminants, not including their innocuous compounds, would be
included as part of this alternative. Monitoring of the
contaminants would involve the collection and analysis at regular
intervals, of groundwater samples from existing Site monitoring
wells, as well as surface water samples from previous creek
locations, to allow tracking of contaminant concentrations and to
monitor the speed, direction, and extent of contaminant
migration. The number and location of well and surface water
samples will be determined during remedial design. In addition,
the need for any additional monitoring wells, which may be
sampled for additional contaminants, will be determined during
the remedial design/remedial action phases. These wells may be
added if it is determined later that groundwater contamination
has left the Site property or if further characterization of the
Site is needed.
Air monitoring," both on-site and at the periphery, which may
involve continuous real-time air monitoring, will be performed,
during Remedial Action.
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Record of Decision
Rochester Property Site
Paqe 40
The goal of this remedial action is to restore groundwater to its
beneficial use as a drinking water source. Based on the
information collected during the RI and on a careful analysis of
all remedial alternatives, EPA and the State of South Carolina
believe that the .selected groundwater remedy will achieve this
goal.
If it is determined, on the basis of the preceding criteria and
the system performance data, that certain portions of the aquifer
cannot be restored to their beneficial use, all or some of the
following measures involving long-term management may occur, for
an indefinite period of time, as a modification of the existing
system:
*
engineering controls such as physical barriers as
containment measures;
*
chemical-specific ARARs will be waived for the cleanup
of those portions of the aquifer based on the technical
impracticability of achieving further contaminant
reduction;
*
institutional controls will be provided/maintained to
restrict access to those portions of the aquifer that
remain above remediation goals;
*
continued monitoring of specified wells and surface
water locations; and
*
periodic re-evaluation of remedial technologies for
groundwater restoration.
The decision to invoke any or all of these measures may be made
during a review of the remedial action, which will occur
minimally at five (5) year intervals in accordance with Section
121(c) of CERCLA, 42 U.S.C. ~ 9621(c).
9.1.2 Applicable or Relevant and Appropriate Requirements
(ARARs)
Applicable Requirements. Groundwater remediation shall comply
with all applicable portions of the following Federal and State
of South Carolina regulations:
SC Reg. 61-62, South Carolina Air Pollution Control Regulations
and Standards, promulgated pursuant to the Pollution Control Act,
SC Code of Laws, 1976, as amended. Establishes limits for
emissions of hazardous air pollutants and particulate matter,. and
establishes acceptable ambient air quality standards within South
Carolina.
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Record of Decision
Rochester Property Site
Paqe 41
SC Reg. '61-68, South Carolina Water Classifications and
Standards, promulgated pursuant to the Pollution Control Act,
SC Code of Laws, 1976, as amended. These regulations establish
classifications for water use, and set numerical standards for
protecting state waters.
SC Reg. 61-71, South Carolina Well Standards and Regulations,
promulgated under to the Safe Drinking Water Act, SC Code of
Laws, 1976, as amended. Standards for well construction,
location and abandonment are established for remedial work at
environmental or hazardous waste sites. .
Relevant and Appropriate Requirements. The following regulations
are relevant to groundwater remediation at the Site.
40 C.F.R. Parts 141-143, National Primary and Secondary Drinking
Water Standards, promulgated under the authority of the Clean
Water Act. These regulations establish acceptable maximQ~ levels
of numerous substances in public drinking water supplies, whether
publicly owned or from other sources such as groundwater.
Maximum Contaminant Levels (MCLs) are specifically identified in
40C.F.R. ~ 300.430(a)(1)(ii)(F) of the NCP as remedial action
objectives for ground waters that are current or potential
sources of drinking water supply. Therefore, MCLs are relevant
and appropriate as criteria for groundwater remediation at this
Site.
40 C.F.R. Part 61, promulga~ed under the authority of the Clean
Air Act. These are the National Emissions Standards for
Hazardous Air Pollutants (NESHAPs). Standards for emissions to
the atmosphere fall under these regulations.
SC Reg. 61-58, South Carolina Primary Drinking Water Regulations,
promulgated pursuant to the Safe Drinking Water Act, SC Code of
Laws, 1976, as amended. These regulations are similar to the
federal regulations described above, and are relevant and
appropriate as remediation criteria for the same reasons set
forth above.
Criteria "To Be Considered" (TBC) and Other Guidance. As noted
above in Section 9.1.2, TBC criteria were utilized and/or
established in the Baseline Risk Assessment and in the FS.
Groundwater cleanup standards were established based on these
documents and both are thus considered TBC.
In the Baseline Risk Assessment, TBC material used included
information concerning toxicity of, and exposure to, Site
contaminants. Sources of such data included the Integrated Risk
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Record of Decision
Rochester Property Site
Paqe 42
Information System (IRIS), Health Effects Assessment Summary
Tables (HEAST), and EPA guidance as specified in the Baseline
Risk Assessment.
In the FS, groundwater concentrations protective of human health
and the environment were calculated based"on the Site-specific
risk calculations from the Baseline Risk Assessment. Certain of
these levels were established as remediation goals in cases where
there is no MCL for a particular contaminant. Specific
contaminants for which health-based goals were established were
for manganese. " The groundwater remediation goals are established
as performance standards in the Section 9.1.3.
Other TBC material include the following:
Guidelines for Groundwater Use and Classification, EPA "
Groundwater Protection Strategy, U.S. EPA, 1986. This document
outlines EPA's policy of considering a site's groundwater
classification in evaluating possible remedial response actions.
As described under Section 1.4, the groundwater at the Site is
classified by EPA as Class lIB and by South Carolina as Class GB
groundwater, indicating its potential as a source of drinking
water.
40 C.F.R. Part 50, National Ambient Air Quality Standards
(NAAQS), promulgated under the authority of the "Clean Air Act.
This regulation includes the National Ambient Air Quality
Standards (NAAQS), and establishes a national baseline of ambient"
air quality levels. The state regulation which implements this
regulation, South Carolina Reg. 62-61, is applicable to the
groundwater portion of the remedy.
Other requirements. As described above in Section 9.1.2,
remedial design often includes the discovery and use of
unforeseeable but necessary requirements. Therefore, during
design of the groundwater component of the selected remedy, EPA
may, through a formal ROD modification process such as an "
Explanation of Significant Differences or a ROD Amendment, elect
to designate further ARARs which apply, or are relevant and
appropriate, to groundwater remediation at this Site.
9.1.3
Performance Standards
The standards outlined in this section comprise the performance
standards defining successful implementation of this portion of
the remedy. The groundwater remediation goals in Table 3 below
shall be the performance standards for groundwater treatment."
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Record of Decision
Rochester Property Site
Paqe 43
TABLE 3
REMEDIATION LEVELS (RIs) FOR GROUNDWATER AT THE SITE'
CHEMICAL OCCDRREHCE CX>NCENTRATION
RANGE R1s MCL RIsK/HI
NUMBER NUMBER (ppm) (ppm) (ppm)
OF OF
DETEcrIONS SAMPLES
Manganese 25 32 ND - 1.390 0.180, 0.05a <1.0
Trichloroethene 9 32 ND - 0.180 0.005 0.005 10-6
Bis(2-ethylhexyl) 3 32 ND - 0.033 0.006 0.006 10-6 '
phthalate
KEY
a = Secondary MCL (not health based)
ND = Non Detect
9.2
Monitor Site Groundwater and Surface Water
Groundwater and surface water samples shall be collected and
analyzed on a regular schedule to be determined by EPA in the
Remedial Design phases. Analytical parameters for groundwater
and surface water samples will include the known Site
contaminants of concern (COCS), unless the COCs are no longer
present or are below the remediation levels consistently;
Specific wells and surface water locations to be sampled will be
determined during the Remedial Design. The analytical data
generated will be used to track the concentrations and movement
of groundwater contaminants. '
10.0,
STATUTORY DETERMINATIONS
The selected remedy for this Site meets the statutory
,requirements set forth at Section 121(b)(1) of CERCLA, 42 U.S.C.
S 9621(b)(1). This section states that the remedy must protect
human health and the environment; meet ARARs (unless waived); be
cost-effective; use permanent solutions, and alternative
treatment technologies or resource recovery technologies to the
maximum extent practicable; and finally, wherever feasible,
employ treatment to reduce. the toxicity, mobility or volume of
the contaminants. The following sections discuss how the remedy
fulfills ,these requirements.
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Record of Decision
Rochester Property Site
Paqe 44
Protection of human health and the environment: The groundwater
remediation alternative will volatilize the TCE, add oxygen to
,the groundwater to biodegrade the bis(2-ethylhexyl)phthalate, and
oxidize the soluble manganese into its more insoluble form,
thereby reducing and eventually removing the future risks to
human health which could result from ingestion of the
groundwater.
Compliance with ARARs: The selected remedy will meet ARARs,
which are listed in Sections 9.1.2 of this ROD.
Cost effectiveness: Among the groundwater alternatives that are
protective of human health and the environment and comply with
all ARARs, the selected alternative is the roost cost-effective
choice because it uses a treatment technology to remediate the
contamination in basically the shortest time frame, at a cost
similar to the other alternatives.
utilization of permanent solutions, and alternative treatment
technoloqies or resource recovery technologies to the maximum
extent practicable: The selected remedy represents the use 9f
treatment for a permanent solution. Among the alternatives that
are protective of human health and the environment and comply
with all ARARs, EPA and the State of South Carolina have
determined that the selected remedy achieves the best balance of
trade-offs in terms of long-term effectiveness and permanence,
reduction of toxicity/mobility/volume, short-term effectiveness,
implementability, and cost. The selected groundwater action is
more readily implementable than the other alternatives
considered. Preference for treatment as a principal remedy
element: The proposed groundwater remediation alternative will
fulfill the preference for treatment as a principal element.
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APPENDIX B
STATE OF SOUTH CAROLINA CONCURRENCE LETTER
ROCHESTER PROPERTY SUPERFUND SITE
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Interim Commissioner: Thomas E. Brown, Jr.
ait//,Z"
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Board: John H. Burriss, Chairman
Richard E. Jabbour. DDS. Vice Chairman
Robert J. Stripling, Jr. Secretary
William E. Applegate. III.
Toney Graham. Jr.. MD
Sandra J. Molander
John B. Pate. MD
Department of Health and Environmentaf Control
2600 Bull Street. Columbia, SC 29201
Promoting Health, Protecting the Environment
August 25, 1993
Mr. Patrick Tobin
Acting Regional Administrator
US EPA, Region IV
345 Courtland Street, N.E.
Atlanta, Georgia 30365
RE:
Final Draft Record of Decision (ROD)
Rochester Property Site
Greenville County
Dear Mr. Tobin:
The Department has reviewed, commented on, and concurs with the Record of Decision
(ROD) for the alternatives selected for remedial action at the Rochester Property site. The
alternatives for remedial activities selected' by EP A include in-situ air sparging to treat
contaminated groundwater and a venting system to facilitate vapor discharge from the vadose
zone.
In concurring with this ROD, the South Carolina Department of, Health and
Environmental Control (SCDHEC) does not waive any right or authority it may have to require
corrective action in accordance with the South Carolina Hazardous Waste Management Act and
the South Carolina Pollution Control Act. These rights include, but are not limited to, the right
to ensure that all necessary permits are obtained, all clean-up goals and criteria are met, and to
take a separal(; action in the event dean-up goals and criteria are not met. Nothing in the
concurrence shall preclude SCDHEC from exercising any administrative, legal and equitable
remedies available to require additional response actions in the event that: (l)(a) previously
unknown or undetected ,conditions arise at the site, or (b) SCDHEC receives additional
information not previously available coricerning the premises upon which SCDHEC relied in
concurring with the selected remedial alternative; and (2) the implementation of the remedial
alternative selected in the ROD is no longer protective of public health and the environment.
SF9J0450. WEH
l\ ,_,,,,'_J ..-..
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Mr. Patrick Tobin
August 25, 1993
Page 2
This concurrence with the selected remedy for the Rochester Property Site is contingent
upon the State's above-mentioned reservation of rights. If you have any questions, please feel
free to contact Mr. Lewis Bedenbaugh at (803)734-5211.
Sincerely,
;?~~
R. Lewis Shaw, P .E.
Deputy Commissioner
Environmental Quality Control
cc:
Hartsill Truesdale
Lewis Bedenbaugh
Keith Lindler
Rebecca Dotterer
Harry Mathis
Charles Gorman
Doug Johns
SF9J0450. WEB
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