United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R04-93/128
January 1993
£EPA Superfund
Record of Decision:
ABC One Hour Cleaners, NC
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R04-93/128
3. Recipient's Accession No.
TOe and Subtitle
SUPERFUND RECORD OF DECISION
ABC One Hour Cleaners, NC
First Remedial Action
& Report Date
01/26/93
7. Authors)
a Performing Organization Rapt. No.
9. Performing Organization Nairn and Address
10 Project Task/Work Unit No.
11. Contract(C)orQrant(C)No.
(C)
(6)
12. Sponsoring Organization Nam* and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
11 Type of Report* Period Covered
800/800
14.
15. Supplementary Notes
PB94-964039
t Abstract (UmH: 200 words)
The 1-acre ABC One Hour Cleaners site is a dry cleaning facility located in
Jacksonville, Onslow County, North Carolina. Land use in the area is predominantly
commercial and residential, with woodlands located to the south. In addition, the site
is located approximately 4,000 feet northwest of Northeast Creek, which eventually
drains into the Atlantic Ocean. The estimated 2,800 people, including, non-commissioned
officers and their families from the Camp Lejeune Marine Corps Base, who reside in the
nearby Tarawa Terrace Housing Development use the surficial aquifer and the Castle
Hayne aquifer as their drinking water supply. ABC One Hour Cleaners began operations
in 1955, and typical to the dry cleaning industry, used PCE as a dry cleaning solvent.
The solvent was stored in an onsite 250-gallon above-ground storage tank, and then PCE
was reclaimed through a filtration-distillation process. Following completion of the
distillation process, the still bottoms, consisting of powder residues, were placed in
the dirt driveway as a "pothole" filler. It is estimated that approximately one ton of
still bottoms was placed on the driveway over a 30-year operating period. As a result
of a 1984 routine water quality evaluation, the Navy determined that VOCs, including
DCE, TCE, and PCE, were present in 10 of the onsite wells, and as a result, the
affected wells were disconnected from the base and community water supply and an
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - ABC One Hour Cleaners,
First Remedial Action
Contaminated Medium: gw
Key Contaminants: VOCs (PCE, TCE)
b. Identlfiers/Open-Ended Terms
COSATI Field/Group
NC
ia Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
72
22. Price
(See ANSI-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R04-93/128
ABC One Hour Cleaners, NC
First Remedial Action
Abstract (Continued)
emergency water line was installed to provide the residents of the nearby Tarawa
development with drinking water. Based on this, a follow-up state study concluded that the
most likely source of ground water contamination in the area was the ABC One Hour Cleaners
site; and a subsequent private investigation, confirmed the presence of PCE and its
derivatives in the onsite soil surrounding the underground septic tank soil absorption
system. In 1986, the State notified ABC One Hour Cleaners of violations incurred to State
statutes for discharging dry cleaning solvents directly into the septic tank system and
into the septic nitrification field. This ROD addresses the onsite ground water plume
emanating from beneath the facility, as OU1. Further field work is needed to better
define the extent of contamination in the soil, and once completed, another ROD for OU2
will be issued. The primary contaminants of concern affecting the ground water are VOCs,
including PCE and TCE.
The selected remedial action for this site includes treating recovered ground water onsite
using air stripping with discharge of the treated water onsite into the Northeast Creek;
treating air emissions using an off-gas treatment system, if needed; screening each
extraction well throughout the anticipated saturated zone of the wells under pumping
conditions; determining the exact number and location of the extraction wells, as well as
the necessity of an off-gas treatment system during the RD phase; monitoring ground water;
well installation/well permit restrictions; and implementing institutional controls,
including deed and ground water use restrictions. The estimated present worth cost for
this remedial action is $2,262,900, which includes an estimated annual O&M cost of
$261,900 for years 1-2 and $197,700 for years 3-7.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific ground water cleanup goals are based on State standards and low
concentration contract required quantitation limits, and-include 1,2-DCE 70 ug/1; PCE 1
ug/1; TCE 2.8 ug/1; and vinyl chloride 1 ug/1.
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RECORD OF DECISION
ABC ONE-HOUR CLEANERS SITE
JACKSONVILLE, NORTH CAROLINA
OPERABLE UNIT 1
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
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RECORD OF DECISION
ABC ONE-HOUR CLEANERS SITE
TABLE OF CONTENTS
Description Page
DECLARATION FOR THE RECORD OF DECISION I
DECISION SUMMARY 1
1.0 SITE NAME, LOCATION, AND DESCRIPTION 1
1.1 Site Location 1
1.2 Surface Features 1
1.3 Subsurface Features 1
1.4 Hydrogeology 3
1.5 Groundwater Elevation 6
1.6 Aquifer Parameters 13
1.7 Demography and Land Use 13
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES . 13
2.1 Facility Operations and History 13
2.2 Enforcement Activities 17
3.0 COMMUNITY PARTICIPATION HIGHLIGHTS 17
4.0 SCOPE AND ROLE OF RESPONSE ACTION 18
5.0 SUMMARY OF SITE CHARACTERISTICS 19
5.1 Nature and Extent of Contamination 19
5.1.1 Soils 19
5.1.2 Groundwater 20
5.2 Contaminant Distribution, Fate and Transport 26
6.0 SUMMARY OF SITE RISKS 27
6.1 Contaminants of Concern 27
6.2 Exposure Assessment 30
6.3 Toxicity Assessment 34
6.3.1 Carcinogens 34
6.3.2 Noncarcinogens 34
6.4 Risk Characterization 36
6.4.1 Carcinogenic Risks 36
6.4.2 Noncarcinogenic Risks 38
6.5 Ecological Considerations 41
6.6 Risk Uncertainty 44
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RECORD OF DECISION
ABC ONE-HOUR CLEANERS SITE
TABLE OF CONTENTS
Description Page
7.0 DESCRIPTION OF REMEDIAL ALTERNATIVES 44
7.1 Alternative 1 46
7.2 Alternative 2 47
7.3 Alternative 3 47
7.4 Alternative 4 49
8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 50
8.1 Threshold Criteria 50
8.1.1 Overall Protection of Human Health and the Environment 50
8.1.2 Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs) 50
8.2 Primary Balancing Criteria 50
8.2.1 Long-Term Effectiveness and Performance 50
8.2.2 Reduction of Toxiclty. Mobility, and Volume Through Treatment 51
8.2.3 Short Term Effectiveness 51
8.2.4 Implementabillty 52
8.2.5 Cost 52
8.3 Modifying Criteria 53
8.3.1 State Acceptance 53
8.3.2 Community Acceptance 53
9.0 THE SELECTED REMEDY 53
9.1 Performance Standards .53
9.2 Site Specific ARARs 58
10.0 STATUTORY DETERMINATIONS 60
10.1 Protection of Human hearth and the Environment 60
10.2 Compliance with Applicable or Relevant and Appropriate Requirements ..61
10.3 Cost Effectiveness 61
10.4 Utilization of Permanent Solutions and alternative Treatment
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable 61
10.5 Preference for Treatment as a Principal Element 61
i
RESPONSIVENESS SUMMARY APPENDIX A
STATE CONCURRENCE APPENDIX B
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RECORD OF DECISION
ABC ONE-HOUR CLEANERS SITE
TABLE OF CONTENTS
Description
Page
FIGURE 1 Site Location Map 2
FIGURE 2 Location Map for Cross Sections 4
FIGURE 3 Cross Section 5
FIGURE 4 Groundwater Elevations for the Surficial Aquifer for 4/22/92 7
FIGURE 5 Groundwater Elevations for the Surficial Aquifer for 6/2/92 8
FIGURE 6 Groundwater Elevations for the Surficial Aquifer for 6/25/92 9
FIGURE 7 Groundwater Elevations for the Castle Hayne Aquifer for 4/22/92 10
FIGURE 8 Groundwater Elevations for the Castle Hayne Aquifer for 6/2/92 11
RGURE 9 Groundwater Elevations for the Castle Hayne Aquifer for 6/25/92 12
FIGURE 10 Locations of Temporary Monitoring Wells Installed by NRCD 15
FIGURE 11 Surflcial and Castle Hayne Monitoring Well Locations 21
FIGURE 12 Locations of Residential and Base Supply Wells Sampled
as Part of the Remedial Investigation . . . 22
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RECORD OF DECISION
ABC ONE-HOUR CLEANERS SITE
TABLE OF CONTENTS
Description
Page
TABLE 1 VOC Analytical Results of Residential and Base Supply Wells 23
TABLE 2 VOCs Detected in the Surficial Aquifer Wells 24
TABLE 3 VOCs Detected in the Castle Hayne Aquifer Wells 25
TABLE 4 Groundwater Exposure Concentration In the Surficial Aquifer 28
TABLE 5 Groundwater Exposure Concentration In the Castle Hayne Aquifer 29
TABLE 6 Mathematical Model for Calculating Intakes from
the Ingestion of Groundwater 31
TABLE 7 Mathematical Model for Calculating Intakes from
Inhalation Exposure to Groundwater During Showering , 32
TABLE 8 Mathematical Model for Calculating Intakes from
Dermal Exposure to Groundwater During Showering 33
TABLE 9 EPA Welght-of-Evidence Classification System for Carcinogenicity 35
TABLE 10 Health Criteria for Contaminants in the Surficial and
Castle Hayne Aquifers 37
TABLE 11 Chemicals of Concern Contributing to the Total Upper 95%
Carcinogenic Risk In the Surficial Aquifer 39
TABLE 12 Chemicals of Concern Contributing to the Total Upper 95%
Carcinogenic Risk in the Castle Hayne Aquifer 40
TABLE 13 Chemical of Concern Exceeding the Upper 95%
Hazard Quotient of 1 for an Adult in the Surficial Aquifer 42
TABLE 14 Chemical of Concern Exceeding the Upper 95%
Hazard Quotient of 1 for a Child In the Surficial Aquifer 43
TABLE 15 Groundwater Clean Up Levels 48
TABLE 16 Estimated Capital Costs for the Selected Remedy 54
TABLE 17 Estimated O & M Costs for the Selected Remedy 56
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DECLARATION FOR THE RECORD OF DECISION
OPERABLE UNIT #1: GROUNDWATER
Site Name and Location
ABC One-Hour Cleaners Site
Jacksonville, Onslow County, North Carolina
Statement of Basis and Purpose
This decision document presents the selected remedial action for the ABC One-
Hour Cleaners Site, Operable Unit #1: Groundwater in Jacksonville, North Carolina.
The remedy 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), and to the
extent practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). This decision document explains the factual and legal
basis for selecting the remedy for the Site.
Assessment of the Site
Actual or threatened releases of hazardous substances from the Site, if not
addressed by implementing the response action selected in this Record of
Decision (ROD), may present an imminent and substantial endangerment to
public health, welfare, and/or the environment.
Description of the Selected Rerr.adv
This remedy addresses the groundwater contamination at the Site. The major
components of the selected remedy include:
Contaminated groundwater above ARARs (Applicable or Relevant and
Appropriate Requirements) will be extracted from the Surficial and the
Castle Hayne aquifers using extraction wells;
The extracted groundwater will be treated by air stripping and an off-gas
treatment system (if needed);
Surface water discharge of the treated groundwater will be to Northeast
Creek via a National Pollutant Discharge Elimination System (NPDES);
Periodic monitoring will be conducted to assess the effectiveness of the
remedy for a period up to 30 years; and
Institutional controls will be placed on well construction and water use in
the general area of the Site.
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ROD
ABC Site
Page 1
RECORD OF DECISION
DECISION SUMMARY
1.0 SITE NAME. LOCATION. AND DESCRIPTION
M Site Location
ABC One-Hour Cleaners Site (also referred to as the ABC Site or the Site) is
located at 2127 Lejeune Boulevard, Onslow County, Jacksonville, North Carolina
(Rgure 1). Jacksonville, NC is located on the coast about forty-five miles north of
Wilmington, NC. The dry cleaning facility encompasses an area of approximately
1 acre. ABC One-Hour Cleaners consists of three buildings joined to form one
complex and is located on the southern portion of the property. A small parking
lot fronts Lejeune Boulevard with driveways on the east and west of the complex.
The northern most one-third of the Site is a grassy field. Across Lejeune Boulevard
to the south are woodlands and the Tarawa Terrace Housing Development. The
Tarawa Terrace complex serves as housing for non-commissioned officers of the
Camp Lejeune Marine Corps Base (Base), and their families.
1.2 Surface Features
The ABC Site is situated at an elevation of about 30 feet above mean se level
(msl). The facility is located approximately 4,000 feet northwest of Ncr heast
Creek, which is situated at an elevation of approximately 5 feet above msl and
is influenced by tidal changes. Elevations decline gradually to the south and
southeast, toward Northeast Creek. This creek flows southwestwardly tow ^s the
New River, which drains into the Atlantic Ocean.
Surface runoff from the ABC Site flows overland into ditches and culverts that are
directed across Highway 24 onto Base property and; along with runoff originating
on the Base, into Northeast Creek.
1.3 Subsurface Features
The oldest geologic formation penetrated by a water well in Onslow County is
the Peedee. It is not known to crop out but lies within 30 feet of the surface in
some valleys northwest of Richlands town. Coastward, the Peedee is more deeply
buried, lying under a wedge of Castle Hayne limestone that thickens toward the
coast. The Castle Hayne is exposed in many places along the New River
between Richlands and Jacksonville. Southwest Creek and White Oak River are
the other streams whose channels lie in the limestone in the northern part of the
county. The Yprktown formation overlies the Castle Hayne, but it has been
eroded away in parts of the county north of Jacksonville. This unit consists of
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Statutory Determinations
The selected remedy is protective of human hearth 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 (or resource
recovery) technology to the maximum extent practicable, and satisfies the
statutory preference for remedies that employ treatment that reduce the toxicity,
mobility, and/or volume as a principal element.
Because this remedy may result in hazardous substances remaining on-site above
ARARs for more than five years, a review will be conducted within five years after
commencement of the remedial action to ensure that the remedy continues to
provide adequate protection of human health and the environment. A 5-year
review (or performance evaluation) will be prepared at least once every five
years until groundwater contaminant concentrations no longer exceed ARARs.
Patrick M. Tobin
Acting Regional Administrator
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ROD
ABC Site
Page 2
FIGURE 1 - SHE LOCATION MAP
ABC ONE-HOUR CLEANERS
Nt
OUT UJEUK£
KILITAtT IEKIVATIW
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ROD
ABC Site
Page 3
lenses of sand, clay, marl, and limestone. Along the coast, the Yorktown reaches
a thickness of about 60 feet, but is thinner inland. The Yorktown is exposed in
several ravines near Silverdale and occurs within 60 feet of the surface in several
wells at the Base. A thin layer of sand and clay, chiefly sand, of Pleistocene Age
conceals the older formation in the interstream areas.
The sediments of the Coastal Plan physiographic province consist of interbedded
sands, clays, calcareous clays, shell beds, sandstone, and limestone. These
sediments are layered in nearly horizontal interfingering beds and lenses that
gently dip and thicken to the east. In the Base area, sediments were deposited
in marine or near-marine environments, and are about 1,500 feet thick.
Information on the shallow subsurface geology specific to ABC Site was collected
du;ng the soil boring program and the Surficial and Castle Hayne aquifer
monitoring well installation programs of the Remedial Investigation (Rl). Figure 2
shows the location of geological cross-sections relative to the Site and Figure 3
presents the details of the cross-sections.
The soils at the Site area have been classified within the Onslow fine sandy soil
association. Underlying the surface soils (approximately 5- to 7-inches thick) is a
6- to 8-inch thick hardpan layer. This hardpan is composed of fine sand
cemented with organic matter and iron, and may locally inhibit the downward
movement of recharge.
1.4 Hydrogeology
A series of investigations were conducted as part of the Rl to characterize i.'-e
hydrogeology at the Site and in the vicinity. These investigations included
lithologic sampling, water level measurement in the monitoring wells, and aquifer
tests at two shallow and two deep monitoring wells. The two aquifers of concern
in the vicinity of the ABC Site are the Surficial aquifer and the Castle Hayne
aquifer. The findings of these investigations are summarized in the following
paragraphs.
The Surficial aquifer is comprised primarily of saturated quartz sand which extends
to a depth of approximately 70-feet Below Ground Surface (BGS) across the study
area. Overlying the saturated sand is a zone of interbedded sands, silts, and clays
extending from ground surface downward to the top of the saturated sands at
approximately 26-feet BGS. The lower portion of this interbedded zone is
saturated. From a comparison of the depth to first saturated soil (as observed
during the lithologic samples collected during well installation) to the depth-to -
water below ground surface (from water level data collected after well
development, adjusted from top-of-casing reference to ground surface
reference), the static water levels in the wells are typically higher than the first
occurrence of saturated soil. This suggests that the interbedded zone acts to
partially confine the Surficial aquifer.
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ROD
ABC Site
Page 4
FIGURE 2 - LOCATION MAP FOR CROSS -SECTIONS
NORTH
ABC ONE-HOUR
CLEANERS
CAMP LEJEUNE
MARINE CORPS BASE
LEGEND
S, A SURF1CIAL AQUIFER MONITORING WELL
ci® CASTLE HAYNE AQUIFER MONITORING WELL
tt-4. SOIL BORING
SCALE (F««t)
0 200 400
100 300
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A
A
40 1
30 1
20
0
-20
-30 —
-40
-50
-60
-70
-80
-90
100
110
120
130
140
150
160
170
180
C1 (30.60) C2 (32.02) fs
\ S^ (30.58) SStl31'75> f?2 (32.46) |
••
* f~
*•(&<) ! j
i — J. x
SILTY SAND
0' 75' 150'
i I I
• /<»\ INTERBEDDED A (53L
H52^ SILTS AND CLAYS Jt:
QUARTZ SAND
—
FOSSILIFEROUS SAND AND GRAVEL .
FOSSILlFEROUS SANDY SILT
HORIZONTAL SCALE
VERTICAL EXACERAT10N - SX
J (32.95) c
C3 (33.40) \
f *
SURFICIAL AQUIFER
. CASTLE HAYNE Adi.
HIGHLY CEMENTED FOSSILlFEROUS SAND
-— ___ —=q
LEGEND
4 (32.18)
pS4 (32.21)
^
f__CLAYEY SAND
SILTY SAND
FOSSILIFERO
. GRAVEL
FOSS1LIFEROU
"• ^
o
m
GO
O
in
3
o
CO
B
(32.03)
,£5 (31.89)
QUARTZ SAND
SILTY SAND
FOSSlLirSROUS SAND
AND GRAVEL
13 (33.04)
S3 (32.95)
B'
rS9 (32.74)
„ INTfRBEDDSD SANDS.
I (56> SILTS AND CLAYS «
(59)
SURFICIAL AQUIFER
CASTLK HAYNE AQUIFER
L1THOLOCIC CONTACT (DASHED WHERE INFERRED)
SURFICIAL AQUIFSR/CASTLE HAYNE AQUIFER CONTACT
(DASHED WHERE INFERRED)
FIRST SATURATED SOIL ENCOUNTERED DURING WELL DRILLING
DEPTH-TO-WATER BELOW GROUND SURFACE
UEASVRBD IN WELLS 4/22/9Z
BENTONITE SEAL.SAND PACK AND WELL SCREEN
Ct (30.60) WELL NUMBER (GROUND SURFACE ELEVATION, IN FEET HSL)
SB4 (31.75) SOIL BORING NUUBER (GROUND SURFACE ELEVATION. IN FEET ItSL
>
^3 00
*§ 2§
01 5f O
HIGHLY CEMENTED FOSSILlFEROUS SAND
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ROD
ABC Site
Page 6
The Castle Hayne aquifer underlies th$ Surficial aquifer at the Site. The Castle
Hayne aquifer, at the Site area, is comprised primarily of saturated fossiliferous
sands and gravels with variable silt content. The uppermost portions of the aquifer
(typically from about 70-feet BGSto about 100- to 120-feet BGS) contain less than
about 15% silt by volume. Below this depth, the limited information available from
the two well boreholes advanced below 100-feet BGS (well borehole Cl was
advanced to 104-feet BGS and well borehole C4 was advanced to 200-feet BGS)
indicated that the formation was comprised of approximately equal volumes of
saturated fossiliferous silts and sands. At location Cl, the silt content increased to
about 50% at a depth of 104-feet BGS. At location C4, the silt content was at
approximately 50% from about 140-feet BGS to about 200-feet BGS.(See Rgure 2
for the locations of the wells and Rgure 3 for the cross sections).
A highly cemented layer of fossiliferous sand was encountered at a depth of
approximately 90-feet BGS. At three of the Castle Hayne well locations (C2, C3,
and C5), drilling refusal was encountered at this layer, and the wells were
screened from 10 feet above the cemented layer to total depth. At locations Cl
and C4, the layer was penetrated and the screens were set below the layer. All
of the Castle Hayne wells were screened above the lower, siltier portion of the
Castle Hayne except well C4. At well C4, the upper half of the 10-foot long
screen intercepted a lens of fossiliferous silty sand (estimated at about 5-feet
thick).
No confining unit was observed separating the Surficial aquifer from the Castle
Hayne aquifer. At all locations except C3, a 3-to-10 foot thick silty sand (silt
content estimated at approximately 30% or less) was observed at the base of the
Surficial aquifer.
1.5 Groundwater Elevations
The groundwater elevation information presented is based on groundwater levels
measured in Surficial aquifer monitoring wells and Castle Hayne aquifer monitoring
wells on April 22, 1992; June 2, 1992; and June 25, 1992. Rgures 4, 5 and 6
represent the Surficial aquifer groundwater elevation maps for each date and
Rgures 7,8 and 9 represent the potentiometric surface maps for the Castle Hayne
aquifer.
Examination tp the Surficial aquifer groundwater elevation maps (Rgures 4,5 and
6) reveals a fairly consistent groundwater surface. The highest elevations are
observed in the northwest comer of the Site in well SI, with elevations gradually
decreasing to the southeast, with wells S10 and S4 exhibiting the lowest Surficial
aquifer groundwater elevations at the Site. From the observed elevations,
groundwater appears to be flowing from the northwest to the southeast towards
Northeast Creek.
A review of the Castle Hayne aquifer groundwater elevation maps (Figures 7', 8
and 9) indicates that, as with the Surficial aquifer, there is considerable
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ROD
ABC ate
Page?
FIGURE 4 - GROUNDWATER ELEVATIONS FOR THE SURFICIAL AQUIFER FOR 4/22/92
NORTH
ESTIMATED
GROUNDWATER
FLOW DIRECTION
ABC ONE-HOUR
CLEANERS
ESTIMATED
GROUNDWATER
FLOW DIRECTION
CAMP LEJEUNE
MARINE: CORPS BASE
PELEUU Dfiivr
LEGEND
SI A SURFICIAL AQUIFER MONITORING WELL
Z3.7Z CROUNDWATER ELEVATION (IN FEET MSL)
.\3- CROUNDWATER ELEVATION CONTOUR (IN FEET MSL)
SCALE (F««t)
0 200 400
100 500
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ROD
ABC Stte
PageS
FIGURE 5 - GROUNDWATER ELEVATIONS FOR THE SURFICIAL AQUIFER FOR 6/2/92
NORTH
ESTIMATED
GROUNDWATER
FLOW DIRECTION
ABC ONE-HOUR
CLEANERS
ESTIMATED
GROUNDWATER
FLOW DIRECTION
CAMP LEJEUNE
MARINE CORPS.BASE
LEGEND
Si A SURFICIAL AQUIFER MONITORING WELL
ZZ.7Z GROUNDWATER ELEVATION (IN FEET MSL)
.\3- GROUNDWATER ELEVATION CONTOUR (IN FEET MSL)
SCALE (F««f)
0 200 400
100 300
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ROD
ABC Site
c ge 9
FIGURE 6 - GROUNDWATER ELEVATIONS FOR THE SURFICIAL AQUIFER FOR 6/25/92
NORTH
ESTIMATED
GROUNDWATER
FLOW DIRECTION
ABC ONE-HOUR
CLEANE
ESTIMATED
GROUNDWATER
FLOW DIRECTION
CAMP lEJEUNE
MARINE CORPS BASE
LEGEND
SCALE (F.«t)
Q 200
Si A SURFICIAL AQUIFER MONITORING WELL
ZZ.7Z CROUNDWATER ELEVATION (IN FEET USL)
_ 13 - GROUNOWATER ELEVATION CONTOUR (IN FEET MSL)
too
300
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ROD
ABC Site
Page 10
FIGURE 7 - GROUNDWATER ELEV. FOR THE CASTLE HAYNE AQUIFER FOR 4/22/92
ci a.49
NORTH
ABC ONE-HduR
CLEANERS
ESTIMATED
CROUNDWATER
flOW DIRECTION
CAMP LEJEUNE
MARINE CORPS BASE
LEGEND
Cl® CASTU HAYNE AQUIFER MONITORING WELL
23.73 CROUNDWATER ELEVATION (IN FEET MSL)
,\3- GROUNDWATER ELEVATION CONTOUR (IN FEET MSL)
SCALE (F«.t)
0 200 400
100
300
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ROD
ABC Site
Page 11
FIGURE 8 - GROUNDWATER ELEV. FOR THE CASTLE HAYNE AQUIFER FOR 6/2/92
NORTH
ABC ONE-HOUR
CLEANERS
ESTIMATED
GROUNDWATER
fLOW DIRECTION
CAMP LEJEUNE
MARINE CORPS BASE
LEGEND
Cl« CASTLE HAYNE AQUIFER MONITORING WELL
33.73 CROUNDWATER ELEVATION (IN FEET MSL)
_ \ 3 - CROUNDWATER ELEVATION CONTOUR (IN FEET MSL)
SCALE (F««t)
0 200 400
100
300
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ROD
ABC Site
Page 12
FIGURE 9 - GROUNDWATER ELEV. FOR THE CASTLE HAYNE AQUIFER FOR 6/25/92
NORTH
ABC ONE-HOUR
CLEANERS
ESTIMATED
GROUNDWATER
FLOW DIRECTION
CAMP LEJEUNE
MARINE CORPS BASE
PELEUU DBivr
LEGEND '
Cl« CASTLE HAYNE AQUIFER MONITORING WELL
GROUNDWATER ELEVATION (IN FEET MSL)
CROUNDWATER ELEVATION CONTOUR (IN FEET MSL)
SCALE (F««t)
200 400
100 300
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ROD
ABC Site
Page 13
consistency in the groundwater surfaces on the three test dates with groundwater
flowing in the same general direction.
The test data indicates that there is a downward vertical hydraulic gradient which
varies across the Site, and suggests that there is some degradation in hydrologic
communication between the Surficial and Castle Hayne aquifers which varies
across the Site. No geologic structure was identified that appeared capable of
acting as an aquitard between the Surficial and Castle Hayne aquifers. It is
possible that some of the variation in groundwater elevations is attributable to the
presence of a thin (estimated at approximately 0.5 feet) highly cemented layer
of fossiliferous sands observed within the Castle Hayne aquifer at a depth of
approximately 90-feet BGS.
1.6 Aquifer Parameters
The following aquifer parameters are based on the aquifer (pump) tests
conducted at the ABC Site in June of 1992:
Surficial aquifer: Effective Porosity = 0.15
Linear Groundwater Flow Velocity = 0.48 ft/day
Hydraulic Conductivity = 10.3 ft/day
Castle Havne aquifer: Effective Porosity =0.10
Linear Groundwater Flow Velocity =0.84 ft/day
Hydraulic Conductivity = 14 ft/day
The hydraulic gradients for the Surficial and Castle Hayne aquifers are 0.007 and
0.006 respectively.
1.7 Demography and Land Use
The ABC Site is located in the Jacksonville city limits. The population within a
1-mile radius of the Site is approximately 2,800 and includes approximately 726
houses. Properties in the areas to the east and west of the ABC Site are presently
used for general retail and commercial business purposes. To the north of the Site
are residential areas, including Pinewood Downs, a multi-family residential
development. Land located to the south serves as housing for noncommissioned
officers and also contains woodlands.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 Facility Operations and History
ABC One-Hour Cleaners, Inc., is a North Carolina corporation registered with the
Secretary of State as of March 4,1958. Martha Melts and Milton Melts purchased
the property on which the ABC One-Hour Cleaners facility is located on
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ABC Site
Page 14
September 16, 1964. Prior to purchasing, the Melts' leased the property from
Carolina Eastern Realty Company, Inc. (lease entered into on May 2, 1955).
According to the lease document, the building was previously used as a
model/hobby shop. Currently, Mr. Melts serves as the President of ABC One-Hour
Cleaners; Victor Melts is the Vice President, Secretary, and Treasurer. Victor Melts
and Milton Melts are the sole directors and shareholders of ABC One-Hour
Cleaners.
Typical of the dry cleaning industry, ABC One-Hour Cleaners utilizes
tetrachloroethene (PCE) as a dry cleaning solvent. The solvent was stored in a
250-gallon above-ground storage tank located along the west side of the
building. Used PCE was reclaimed through a filtration-distillation process
contained within the main building. Following completion of the distillation
process, the still bottoms, consisting of powder residues, were placed in the dirt
driveway west of the building as a 'pothole1 filler. It is estimated that
approximately 1 ton of still bottoms was placed on the driveway over a 30-year
operating period. Since 1985, ABC One-Hour Cleaners has used the services of
Safety-Ween, Inc. to recover and recycle its dry cleaning fluid.
According to the Resource Conservation and Recovery Act (RCRA), still bottoms
are considered to be a hazardous waste (RCRA Waste No.F002). ABC One-Hour
Cleaners is classified as a small quantity generator under RCRA
(No.NCD981751126), and generates less than 1,000 kilograms per month of
hazardous waste.
A septic tank soil absorption system is located in the rear of the building complex.
The septic system consists of an underground concrete tank with a concrete lid
and a pipe of unknown length that discharges into the subsurface soil. The septic
system is located within 4 feet of the PCE storage tank. The age of the septic
system reportedly dates back to the original construction of the building (1940's).
ABC One-Hour Cleaners began occupying the building in 1955. In the 1960's,
ABC One-Hour Cleaners installed a floor drain to the septic tank and tied its
wastewater discharge, except for its lavatories, into the Weyerhaeuser Properties'
water and sewer system. The lavatories remained tied into the septic system until
approximately 1985, at which time they were also tied into the Weyerhaeuser
Properties' system.
In July 1984, as part of a routine water quality evaluation, the Department of the
Navy collected groundwater samples from 40 of the 100 community water supply
wells located on the Base. The Navy determined that dichloroethene (DCEX
.trichloroethene (TCE), and PCE were present in 10 of the wells sampled. Of the
10 wells in which groundwater contamination was noted, 8 of the wells had been
directly impacted by sources located on the Base. The remaining two wells were
located within the Tarawa Terrace well field (TT-23 and TT-26; see Rgure 10) in the
vicinity of two off-base commercial dry cleaning operations, ABC One-Hour
Cleaners, Inc., and Glam-O-Rama, Inc.
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ABC Site
Page 15
FIGURE 10 - LOCATIONS OF TEMPORARY MONITORING WELLS INSTALLED BY NRCD
IN 1985
CAMP LEJEUNE
MARINE CORPS BASE
CAMP LEJEUNE
MARINE CORPS BASE
IfOEMh
A IT-IS — TMAKA TBWACI eCMUUWTY
.
rr MKD M MM.
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ABC Site
Page 16
In February 1985, the two affected wells plus a third community well (TT-25) were
disconnected from the Base's drinking water supply system. In June 1985, an
emergency water line from the Base's Holcomb Boulevard system was installed
to provide the Tarawa Terrace development with drinking water.
During the same time period, the Wilmington Regional Office (WiRO) of the
Division of Environmental Management, North Carolina Department of Natural
Resources and Community Development (NCDNRCD), now called North Carolina
Department of Environment, Health and Natural Resources (NCDEHNR), was
notified by the United States Marine Corps, that two deep water wells in the
Tarawa Terrace housing area at the Base were contaminated by what appeared
to be off-site sources. From April through September 1985. WiRO staff conducted
a grdundwater pollution study to define the source of PCE in wells within the
Tarawa Terrace well field. The study concluded that the most likely source of
groundwater contamination was determined to be ABC One-Hour Cleaners, Inc.
On January 24,1986, WiRO notified Mr. Milton Melts, president of ABC One-Hour
Cleaners, Inc., that he was in violation of the following North Carolina General
Statutes:
1) G.S. 143-215. l(a)(5) for changing the nature of waste discharged
through a disposal system by disposing of dry cleaning solvents in the
septic tank system.
2) G.S. 143-215.1 (a)(6) for discharging dry cleaning solvents in the septic
tank nitrification field resulting in the violation of standards for
underground waters.
Subsequent to the receipt of the Notice of Violation issued by NCDNRCD, ABC
One-Hour Cleaners contracted the services of Law Engineering and Testing, Inc.,
to conduct preliminary investigations of the septic tank soil absorption system and
surrounding soils. The results of two preliminary investigations conducted on April
8, 1986 and September 10-11, 1986, confirmed the presence of PCE and its
derivatives in soils immediately surrounding the septic tank and adjacent to an
existing floor drain. Thus, ABC One-Hour Cleaners was confirmed as the source
of groundwater contamination.
On October 30, 1986, ABC One-Hour Cleaners submitted a proposal for a
remedial action plan involving partial removal and/or treatment of contaminated
soils. The plan, according to NCDNRCD, failed to address problems associated
with the groundwater contaminant plume emanating from beneath the ABC
One-Hour Cleaners facility. The NCDNRCD rejected the proposed plan and
proceeded with application of the Hazard Ranking System (HRS) and nomination
of the Site for inclusion on the Superfund National Priorities List (NPL) of
uncontrolled hazardous waste sites.
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ABC Site
Page 17
2.2 Enforcement Activities
Based upon observed releases of PCE and existing groundwater contamination,
as well as other factors considered in the application of the MRS, the ABC One-
Hour Cleaners Site was scored at 29.11. Sites with scores of 28.5 or greater are
listed on the NPL Accordingly, the Site was proposed for NPL listing in June 1988,
and placed on the final list in March 1989.
On September 29,1988, EPA sent a special notice letter to the current landowner
and president of ABC One-Hour Cleaners Inc., Milton Melts, notifying him of his
potential responsibility for the release of hazardous substances at the ABC One-
Hour Cleaners Site in Jacksonville, North Carolina and requesting him to conduct
a Remedial Investigation and Feasibility Study (RI/FS) for the Site.
Since the PRPs were unable to conduct the RI/FS, EPA hired Roy F. Weston, Inc.
to conduct the RI/FS. Following Work Plan approval on June 28,1990, the Rl field
activities began and were completed in June of 1992. The Rl and FS reports were
completed in November 1992. This Record of Decision (ROD) addresses Operable
Unit #1: Groundwater contamination at the ABC Site. Further field work will be
done to define the extent of contamination in the soils. After this is completed,
a ROD will be written for that Operable Unit.
3.0 COMMUNITY PARTICIPATION HIGHLIGHTS
In accordance with the public participation requirements of Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA), Section 117
and the requirements of the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP), a comprehensive community relations program was
developed and implemented throughout the remedial process at the ABC Site.
Community interviews were conducted in early 1990 to find out the concerns of
the community and to explain the Remedial Investigation process to the citizens.
Their concerns are outlined in the Community Relations Plan. This plan was
finalized on Sep-ember 10,1990 and also contains contacts and interested parties
throughout the government and the local community. The Plan identifies
communication pathways to assure timely dissemination of pertinent information.
On August 16, 1990, an Open House was held at City Hall in Jacksonville, North
Carolina as a kick-off meeting for the RI/FS. This Open House was held to allow
the public the opportunity to come and voice their concerns and questions
regarding the ABC Site and the upcoming Remedial Investigation.
A RI/FS kick-off fact sheet was distributed in April of 1991 before field activities
began at the ABC Site. This fact sheet outlined what to expect during the RI/FS.
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ABC Site
Page 18
Following the completion of the Rl, a RI/FS Rndings Fact Sheet was prepared and
released to the public in September of 1992. This fact sheet presented the results
of the Rl.
The Proposed Plan fact sheet was mailed to the information repository and to the
individuals at the Site mailing list on October 30, 1992. The RI/FS reports were
released to the public on November 6, 1992. These documents were made
available to the public in both the Administrative Record and the information
repository maintained at the Onslow County Public Library and the EPA Region IV
Records Center. The notice of the availability of these documents and notification
of the Proposed Plan Public Meeting was announced in The Jacksonville Daily
News and The Wilmington Morning Star on November 6,1992. The Proposed Plan
Fact Sheet was mailed on October 30, 1992 and the Proposed Plan Public
Meeting was held on November 19,1992 at the Onslow County Public Library. At
this meeting, representatives from EPA and NCDEHNR presented EPA's preferred
alternative for cleanup of the Site and answered any questions the public had
regarding the preferred alternative, other alternatives considered in the FS, or any
other concerns the public had related to the cleanup of this Site.
Various press releases were issued throughout the different stages of this project.
These press-releases announced meetings and announced the preferred
alternative for cleanup at the Site.
The public comment period was held from November 6,1992 through December
7, 1992. A response to the comments received during this comment period,
including those raised during the Proposed Plan public meeting, are addressed
in the Responsiveness Summary, which is part of this Record of Decision. The
Responsiveness Summary also incorporates a transcript of the Proposed Plan
public meeting.
4.0 SCOPE AND ROLE OF RESPONSE ACTION
The selected remedy for the Site is intended to address the threats to human
hearth and the environment. This remedial action will remove the threat posed
by contaminated groundwater at the Site. Remediating groundwater will prevent
ingestion or inhalation of contaminated groundwater at or above the Maximum
Contaminant Levels (MCLs) and North Carolina Groundwater Quality Standards
(NCGWQS) and will restore groundwater to contaminant levels below MCLs and
NCGWQSs. This ROD is addressing Operable Unit #1: Groundwater. Another ROD
for Operable Unit #2 will be written in the future after the nature and extent of soil
contamination has been defined.
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ABC ate
Page 19
5.0 SUMMARY OF SITE CHARACTERISTICS
5.1 Nature and Extent of Contamination
During the field investigation program, samples for chemical analysis were
collected from soil and groundwater media and from liquid and sludge phases
from the septic tank located underneath the ABC One-Hour Cleaners facility.
Results of the analysis conducted as part of the Rl confirmed the presence of
PCE in groundwater in the Surficial and Castle Hayne aquifers and the septic tank
wastes. Other contaminants observed within the groundwater include
constituents which may have been present in commercial grades of PCE and/or
are breakdown components of PCE (trichloroethene, dichloroethene, and vinyl
chloride).
5.1.1 Soils
Although soils data is not within the scope of this operable unit, it is useful to
mention, that Volatile Organic Compounds (VOCs) were observed in several
unsaturated soil samples collected around the ABC Site, supporting the hypothesis
that the septic tank acts as a source of VOCs. These VOCs in the septic tank
traveled through the unsaturated soil to reach the groundwater, and therefore,
it is expected that VOCs would be present in the unsaturated soils under and near
the ABC Site. The soil contamination will be investigated further as Operable Unit
#2 and at that time a ROD will be written addressing the contamination in the
soils.
Source area investigation in the Rl was focused on two media: liquid and sludge
phase material from the septic tank at the ABC Site. Two samples were collected
from the septic tank. The first sample, was collected from the liquid material
present in the upper part of the septic tank and the second sample was
collected from the sludge material at the bottom of the tank. Concentrations of
detected VOCs in the sludge sample exhibited significantly higher concentrations
than observed in the liquid sample, with concentration increases varying from
about a factor of two for vinyl chloride, to a factor of 30 for PCE. Based on the
results of these field investigations, the ABC Site, specifically the former septic tank
system, is the primary source for VOCs at the Site.
Other source areas at the Site may have existed (e.g., historical reports indicate
that still bottoms from ABC Site were used to fill potholes in the driveway along the
west-side of ABC Site), but this source is believed to be of secondary concern
because concentrations found in the septic tank were much higher. Other
organic compounds such as pesticides (DDE, DDD), Phthalates, phenols, and
Polycyclic Aromatic Hydrocarbons (PAHs) were detected within the septic sludge
but not in the groundwater at the Site.
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ABC Site
Page 20
5.1.2 Groundwater
The groundwater investigation at the Site began with using Direct Push
Technology (DPT). The DPT investigation took three weeks to complete in which
approximately 100 groundwater samples were analyzed at varying depths. This
initial investigation served as an aid to better define areas where monitoring wells
should be installed.
After the DPT investigation, both shallow and deep monitoring well locations were
identified. Ten Surficial monitoring wells and-five deep monitoring wells were
installed in locations shown in Figure 11. Groundwater samples were collected
from seven existing wells (Figure 12), the ten Surficial monitoring wells, and the five
deep Castle Hayne monitoring wells. The results of this sampling event are
described below.
Base and Residential Supply Well Sampling
Supply wells sampling (Figure 12) suggest that the concentrations of chlorinated
VOCs, primarily PCE and TCE, are highest immediately down-gradient of the ABC
Site and decrease in the down-gradient direction (southeast) away from the ABC
Site, Non-chlorinated VOCs detected in well TT-54 do not appear to be related
to the ABC Site. Table 1 presents a summary of VOC analytical results for these
wells.
Surficial Aquifer Monitoring Wells
The VOCs detected in the Surficial aquifer monitoring wells above the drinking
water standards were PCE, TCE, 1,2-DCE and vinyl chloride. A summary of the
VOCs detected is presented in Table 2. The MCLs and North Carolina
Groundwater Quality Standards (NCGWQS) are also listed in the table for
comparison. Surficial aquifer wells S2 and S3 were found to have significantly
elevated VOCs concentrations. No pesticides or polychlorinated biphenols (PCBs)
were detected in any of the Surficial aquifer monitoring wells. Metals detected
were below the drinking water standards or the concentrations detected are
considered representative of the area.
Castle Hayne Aquifer Monitoring Wells
Seven VOCs were detected at one or more of the Castle Hayne aquifer
monitoring wells. Acetone was only detected in well C5. The detection of
acetone at the concentration reported in well C5 resulted in an elevation of
detection limits (from 10 \ig/\ to 100 |ig/l). The presence of acetone is considered
anomalous (laboratory artifact). Table 3 presents a summary of the results of
VOCs detected in the Castle Hayne aquifer. The highest chlorinated VOC
concentration was observed at well C3. No VOCs were detected in the up-
gradient well Cl and down-gradient well C4. The estimated PCE results (<100
for well C5 may be the result of the past pumping of the Tarawa Terrace
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ate
Page 21
FIGURE 11 - SURRCIAL AND CASTLE HAYNE AQUIFER MONITORING WELLS
LOCATION
NORTH
ABC ONE-HOUR
CLEANERS
CAMP IEJEUNE
MARINE CORPS BASE
LEGEND
Sl& SURFICIAL AQUIFER MONITORING WELL
c, CASTLE HYANE AQUIFER MONITORING WELL
SCALE (F««t)*
0 200 400
100 300
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ABC Site
Page 22
FIGURE 12 - LOCATIONS OF RESIDENTIAL AND BASE SUPPLY WELLS SAMPLED AS
PART OF THE REMEDIAL INVESTIGATION
TT-21
LCCENQ
* TAJUWA TDWAtt COHHUNITY
NORTH
*»-« • RCSIOCMTUI.
WEU.
*ATt» SUPPLT
too MO
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ABC Site
Page 23
TABLE 1
VOC Analytical Results of Residential and Base Supply Wells
(WESTON, July 1991)
(A) Base Supply Wells
Parameter
cis-1 ,2-Dichloroethene
Benzene
Trichloroethene (TCE)
Tetrachloroethene (PCE)
VOC Concentration
TT-23
(ug/L)
<5
<5
<5
<5
TT-25
(ug/L)
1.4 J
<5
5.8
23
TT-26'
(ug/L)
<200/15 J
<200/<100
56J/<62J
340/360
TT-54
(ug/L)
<5
1.3 J
<5
<5
(B) Residential Wells
Parameter
cis- 1 ,2-Dichloroethene
Benzene
Trichloroetfaene (TCE)
Tetnchloroetheoe (PCE)
VOC Concentrttion
RW-01
(ug/L)
<5
<5
<5
<5
RW-02
(ug/L)
<250
<250
<250
760
RW-03
(ug/L)
<5
<5
<5
<5
Notes:
Two sets of values indicate duplicate camples
Estimated Value
-------
VOCs Detected in tbe Surficlal Aquifer Wells (WESTON, April 1992)
Analyte
Benzene
Chlorobenzene
Chloroform
1 , 1 -Dichloroethane
1 ,2-Dichloroethene/(total)
Ethylbenzene
Tetrachloroethene (PCE)
Toluene
1,1,2-Trichloroelhane
Trichloroethene (TCE)
Vinyl Chloride
Xylenes (total)
Federal
MCLs
(ug/L) ,
5
100
100
7
70/100*
700
5
1,000
5
5
.2
10,000
NC
'; GW
1 Standards
(ug/L)
1
300
0.19
7
70/100*
29
0.7
i.ooo
--
2.8
0.015
400
i Well Identification
SI
(ug/L)
.
•vKtSjSfy \y"* H% ?W?
^f|p0iip>|
S2
1 J
Si
f|ff0<^
s^v®*? %* /S?* &
|*P!fliJp"t%
S2
(Dup)
(ug/L)
5J
<£t$b^
'** -^ '^ *"s^j/^^ ?•
. ^.X'% ii> *£* /
>/:,$te?b
I J
^S^ffi
01^^-
i j
S3
(ug/L)
6J
1:$,5«d;':
^ *f S\ f f f fy "•
^l 5,400''^
2J
<<^\;/
i^itl'V
S5
(ug/L)
2 J
5J
3 J
4 J
S6
2 J
28
4 J
. 3J
w-
fi
ro
Key: * cis-l.2-DCE/tnns-l,2-DCE
J Estimated value
Notes: (I) All surficiaj aquifer wells (SI through S10) were sampled and analyzed for the analyles listed in the table. Only detected
values are presented in the table.
(2) Shaded areas indicate concentrations above Federal MCLs and North Carolina Oroundwater Quality Standards.
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ABC Site
Page 25
TABLE 3
VOCs Detected in the Castle Hayne Aquifer Wells (April 1992)
Analyte
Acetone
Benzene
Chloroform
1 ,2-Dichloroethene/(total)
Tetrachloroethene (PCE)
Toluene
Trichloroetnene (TCE)
Federal
MCLs
(ug/L)
-
5
100
70/100'
5
1,000
5
NC
GW
Standards
(ug/L)
-
1
0.19
70/100'
0.7
1.000
2.8
Well Identification
Cl
(ug/L)
C2
(ug/L)
2J
9 J
1 J
3 J
C3
(ug/L)
14
z%M
'Wwfik
C4
(ug/L)
C5
(ug/L)
1,400
V.WV JV W ylfff
X"*&t4t ""Y' «^W
* •. v {<.-
Notes
cis-1,2-DCE/tnms-1,2-DCE
Estimated vtlue
Shaded areas indicate concentrations above Federal MCLs and NCGWQS
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ABC Site
Page 26
water supply wells or may be related to the anomalous acetone result and the
associated higher detection limits. No SVOCs, pesticides, or PCBs were detected
in any of the Castle Hayne monitoring wells. The distribution of metals at the Site
suggests that the ABC Site is not contributing metal contaminants to the
groundwater. Concentrations of metals in the background well are generally
comparable to, or higher than, metals detected in other wells located
downgradient of the Site.
Benzene was also detected above the drinking water standards in C5, but the
source does not appear to be the ABC Site. EPA has notified Camp Lejeune
Marine Corp Base of the presence of benzene in well C5. Accordingly, the Base
will take appropriate action to determine the source of benzene.
5.2 Contaminant Fate and Transport
The septic system was determined to be the primary source of the chlorinated
hydrocarbons at the Site. Constituents of the septic system entered the drain field
and percolated downward through the unsaturated zone to the water table. The
contaminants then were transported by advection and dispersion through the
aquifer system. Chemical processes that may have affected the distribution of
chlorinated hydrocarbons include volatilization, sorption, biodegradation and
breakdown by dehalogenization.
The dehalogenation process would have degradated the PCE into TCE, 1,2-DCE,
and vinyl chloride. The process of volatilization is limited due to the concrete floor
at the ABC Site facility building and the asphalt covered areas that overlay the
soils. The biodegradation process may be enhanced, however, by the presence
of sewage mixed with the PCE.
Historical pumping data of the Base TT wells indicate that pumpage of these wells
created a cone of depression causing the hydraulic gradient to increase in the
southeast direction. The increased gradient likely enhanced the migration of PCE
away from the ABC Site. Also the TT wells probably acted as recovery wells which
captured the contaminants present in the aquifer systems. When the pumping
of these wells was discontinued, removal of the VOCs from the aquifer system also
ceased.
The stoppage of pumping from the TT wells had a dual effect. Once the natural
(non-pumping) hydraulic gradient was restored, the contaminant travel times to
the TT well locations would have decreased; however, the removal of VOCs
would have discontinued, and the plume could .migrate beyond the IT wells to
locations further downgradient of the source area. When the TT wells were
stopped, the groundwater flow resumed its natural gradient which is more to the
east and therefore, the plume has traveled in that direction predominantly.
It should be noted that during the investigation for Operable Unit #2, a well will be
placed downgradient of TT-23 (Rgure 12) to verify that contamination has not
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ROD
ABC Site
Pag© 27
migrated in the southerly direction after pumping ceased.
6.0 SUMMARY OF SITE RISKS
A Baseline Risk Assessment (RA) has been conducted for the ABC One-Hour
Cleaners Site and the results are presented in Section 7 of the Rl report. The
purpose of the RA is to evaluate the potential adverse human health effects due
to the presence of chemicals in the groundwater resulting from past or present
activities at the ABC Site. The RA is also intended to provide information that can
be used to determine the need for remedial action and, if necessary, to select
remedial alternatives.
6.1 Contaminants of Concern
Based on the groundwater data available at the ABC Site and the origins of the
contaminants detected in the groundwater, the contaminants of concern at the
Site are: Tetrachloroethene (PCEXTrichloroethene (TCE), Total 1,2-dichloroethene
(1,2-DCE) and vinyl chloride. By examining the contaminant concentrations in the
Surficial and Castle Hayne aquifers, it is apparent that the larger surface area of
contamination is defined by the Surficial aquifer PCE plume. PCE is also the
contaminant- with the highest detected concentration in the groundwater.
Therefore, the Surficial aquifer PCE contaminant plume will be used to define the
outer boundary of the plume of the contaminants of concern.
Tables 4 and 5 show the groundwater exposure concentrations that were used
in the risk assessment for each chemical in each aquifer. Many of the chemicals
listed in these tables will not be addressed further in the ROD because they do not
pose unacceptable risks and/or the concentrations detected are below the
remediation goals.
Although arsenic, acetone, and benzene have been identified as some of the
contaminants which pose risk according to the Risk Assessment study, these
chemicals will not be addressed in the ROD for the following reasons: Arsenic was
found in one sample below MCLs and NCGWQS and is considered to be a
background concentration, not a Site contaminant. Acetone was also found in
one sample and is considered to be a laboratory artifact and is not related to the
Site contaminants. Benzene was found in one sample above MCLs and
NCGWQS, since this is not a Site contaminant and the well is located on Camp
Lejeune Marine Corps Base, the Base has been notified and will be pursuing the
source of the benzene.
Since acetone and benzene are both VOCs, if present in the groundwater. these
compounds would be treated along with the other VOCs known to be present
in the groundwater and originating from the Site.
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ABC Site
Page 28
Table 4
Groundwater Exposure Concentration - Surficial Aquifer
Chemical
Organics
Benzene
Chlorobenzene
Chloroform
1,1-Dichloroethene
1 ,2-Dichloroethene
Ethylbenzeoe
2-Methylnapthalene
Naptbalene
Tetrachioroethene
Toluene
1 , 1 ,2-Trichloroethane
Trichloroethene
Vinyl Chloride
Xylenes
Inorganics
Arsenic
Barium
Chromium
Cobalt
Lead
Upper 95% Confidence
Limit of the Mean (jtgfL)
2.0-
5.0
3.0"
5.31
1,200-
11.5
3.0"
3.01
5,400*
4.0"-b
2.0-
705m
110*
3.CT
28.0"
191
37.5
15.8
7.9
I in ptooe of te iffcr M« ooofidcox
• S07-OI. SOB4I. SD»«l. Kri SI04I
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ABC Site
Page 29
Table 5
Groundwater Exposure Concentration - Castle Hayne Aquifer
Chemical
Organics
Acetone
Benzene
Chloroform
1 ,2-Dichloroethcne
Tetrachloroethene
Toluene
Trichloroetbene
Inorganics
Arsenic
Chromium
Upper 95%
Limit of the
Confidence
Mean (ftgfL)
1,400»
18.0*
2.0"
14.0*-6
7.0--b
25.0-
28.01
14.0-
32.0"
mion «•• wed in ptex of UK i«per
i Umi in aopk CO54I
<>i% oafidcwc limit of ibc t
n(K( n< nl ite a
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ABC ate
Page 30
6.2 Exposure Assessment
The objective of the exposure assessment is to estimate the degree to which
potential receptors may be exposed to contaminants of concern that are present
at or are migrating from, the Site. One overall exposure condition was
evaluated. This condition is future land use which evaluates potential risks that
may be associated with any probable change in the Site use assuming no
remedial action occurs. Current land use condition was not evaluated because
at the present time the potential for exposure to groundwater has been
eliminated by the removal from service of the contaminated wells (TT-wells). The
affected community (Tarawa Terrace) was placed on the Holcomb Boulevard
water supply.
Available hydrogeologic information shows that the Surficial aquifer is classified
as Class II-B aquifer and the Castle Hayne aquifer is classified as Class II-A aquifer,
resource which should be maintained at drinking water quality. As stated above,
the Surficial aquifer is not currently used for drinking water. The Castle Hayne
aquifer is the principal source of drinking water for the Base, as well as for Onslow
County.
There are currently no surface water bodies located on the ABC Site property and
no current evidence of impact on off-site surface water bodies due to past or
present Site activities. Exposure to contaminated soils was not evaluated in this
Baseline Risk Assessment because it will be considered Operable Unit #2.
The properties to the east and west of ABC Site are presently used for general
retail and commercial business purposes. To the north of the Site are residential
areas and the land located to the south serves as housing for noncommissioned
officers and also contains woodlands; therefore the Site will be available for
unrestricted use in the future and also the current residential areas would remain
residential in the foreseeable future.
A future resident scenario was evaluated in which it was assumed that a home
would be located such that a private supply well would draw water from either
the Surficial or the Castle Hayne aquifer within the plume currently associated with
groundwater contamination from the ABC Site.
The future resident was assumed to be on-site on a daily basis, year round for 350
days/ year of exposure to groundwater. Two age groups were evaluated, a child
age 1 to 6 years old and an adult. The exposure duration for all the exposure
routes was assume to be 30 years and the residential duration was divided into
a six year duration for young children ages 1 to 6 and a 24 year duration for
adults. The mathematical models and the assumptions that were used to
calculate the intakes (i.e., doses) of the chemicals of concern for each receptor
through the applicable exposure route are presented in Table 6 through Table 8.
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Table 6
Model for Cal*1*1 ****"£ !"*•!"* from the
Ingestion of Groundwater
. CWxCFx]
Groundwater Ingesoon
(mg/kg-day) BWxAT
Where:
CW = Chgmiqai concentration in groundwater
CF = Conversion factor (iO"J mg/^g)
IR = Ingestion rate (L/day)
EF = Exposure frequency (days/year)
ED = Exposure duration (years)
BW = Body weight (kg)
AT = Averaging time (days)
Exposure Assumptions (future child and adult residents):
CW = Upper 95% confidence limit of the mean concentration in groundwater
(Table 7-5 and 7-6).
ER = 2 liters/day, for the future adult resident (EPA, 199 la).
= 1 liter/day, for the future child resident (assuming one-half of the adult
ingesnon rate).
/ ,
EF = 350 days/year for the future child and adult residents (EPA, 1991a).
ED = 6 years for the future child resident (EPA, 199 la).
= 24 years for the future adult resident (EPA, 1991a).
BW = 15 kg for the future child resident (EPA, 1991a).
= 70 kg for the future adult resident (EPA, 1991a).
AT = Exposure duration (yean) x 365 days/year for evaluating noncancer risk.
_ _ ** 70 yean x 365 days/year for evaluating cancer risk.
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Table 7
Model for rakff>a**"g inukes from
inhalation Exposure to Groondwater Dnhng Showering
Jflfiucc ircni
Honmgesoon _ CWxCFxMExEPxED
Groundwater Use ~ 3^ x AT
(mg/kg-dty)
Where:
CW = f^fT^E** concentration in groundwater (/xg/L)
CF B Conversion factor (10° rag//ig)
NIE = Nonmgestian exposure equivalent (L/day)
EF = Exposure frequency (days/year)
ED = Exposure duration (yeas)
BW = Body weight (kg)
AT . = Averaging time (days)
Exposure Assumptions (future child and adult residents):
CW = Upper 95% confidence limit of the mean concentration in groundwater
(Table 7-5 and 7-6).
NIE = 2 liters/day for the future adult resident (EPA, 1991c).
1 liter/day for the future child resident (estimated).
EF = 350 days/year for the future child and adult residents (EPA. 1991a).
ED = 6 yean for the future child resident (EPA, 1991a).
= 24 yean for the future adult resident (EPA, 1991a).
BW = 15 kg for the future child resident (EPA, 1991a).
= 70 kg for the future adult resident (EPA. 1991a).
AT = Exposure duration (yean) x 365 days/year for evaluating
risk,
B 70 yean x 365 davs/vear for evahiann£ nrnrrr risk.
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Table 8
Model for Cilraiiflnf tnukes from
Deraui Ezporarc to Gnnudwater
Deanai caaaet _ CWxEAxPCxETxEPxEDxCP
with Groundwuer BWxAT
(mg/ks-i?piii-spfffifi'r format permeability cons""* (cxn/hr)
ET = Exposure Tune (hr/day)
EF * Exposure frequency (days/year)
ED * PjTpnt"r» duration (years)
CF - Vohnnetnc conversion factor for water (1 liter/ 1,000 on3)
BW « Body weight (kg)
AT * Avenging time (period over which exposure is avenged - days)
Exposure Assumptions (for the adult and child residents):
CW = Upper 95% confidence limit of the mean concentration in groundwater
(Table 7-5 and 7-6).
SA - 18.150 cm2 for the adult resident (EPA. 1989a)
- 7,195 cor for the child resident (EPA, 1989a)
PC = See Table 7-10.
ET * 025 noun/day for the furore child and adult resident (EPA, 1989c)
EF = 350 days/year for the future ^'M and adult residents (EPA. 1991a).
ED - 6 years for the future child resident (EPA, 1991a)
* 24 years for the future adult resident (EPA, 1991a)
BW » 15 kg for the future child resident (EPA. 1991a)
* 70 kg for the future adult resident (RAGS, 1991a)
AT = Exposure duration (yean) x 365 days/year for evaluating noncancer
risk,
• 70 vears x 365 davs/vear for evaluatinE cancer risk.
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The potential exposure routes that were considered for groundwater were:
Drinking water inaestion - Ingestion of tap-water and/or beverages
made from tap-water from a domestic source.
Inhalation of chemicals volatilized from aroundwater - Incidental inhalation
of volatile organic chemicals (VOCs) during daily showering or bathing.
Dermal contact - Normal dermal contact with groundwater during
daily showering or bathing.
6.3 Toxlcltv Assessment
In evaluating potential health risks, both carcinogenic and non-carcinogenic
effects must be considered. Excessive exposure to any pollutant can potentially
produce non-carcinogenic effects, while the potential for carcinogenic effects
is limited to exposure to certain substances. The purpose of the toxicity assessment
is to identify and select route-specific non-carcinogenic (reference dose) and
carcinogenic toxicity values (cancer slope factor) for the appropriate
contaminants of concern.
6.3.1 Carcinogens
Slope factors (SFs) have been developed by EPA for estimating excess lifetime
cancer risks associated with exposure to potentially carcinogenic contaminants
of concern. SFs, which are expressed in units of (mg/kg-day)"1, 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 the exposure at
the intake level. The term 'upper bound' reflects the conservative estimate of the
risk calculated from the SFs. Use of these approaches makes underestimation of
the actual cancer risk highly unlikely. SFs are derived from the results of human
epidemiological studies of chronic animal bioassays to which animal-to-human
extrapolation and uncertainty factors have been applied (e.g., to account for the
use of animal data to predict effects on humans).
The EPA weight-of-evidence classifications system for carcinogenicity is presented
in Table 9. .
6.3.2 Noncarclnogens
Reference doses (RfDs) have been developed by EPA for indicating the potential
for adverse health effects from exposure to contaminants of concern exhibiting
noncarcinogenic effects. RfDs, which are expressed in units of mg/kg-day, are
estimates of lifetime daily exposure levels for humans, including sensitive
individuals. Estimated intakes of contaminants of concern from environmental
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Table 9
EPA WEIGHT-OF-EVIDENCE CLASSIFICATION SYSTEM FOR
CARCINOGENICITY
s" w •. * /^Ftf^lfiQV * "•*•"• *'•
- V# /-v*^«f vv^i
A
Bl orB2
C
D
E
:j:^f
Human carcinogenic
Probable human carcinogenic
Bl indicates that limited data are available.
B2 indicates sufficient evidence in animals and
inadequate or no evidence in humans.
Possible humans carcinogen
Not classifiable as to human carcinogenicity
Evidence of human noncarcinogenicity for humans
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media (e.g., the amount of a contaminant of concern ingested from
contaminated drinking water) can be compared to the RfDs. RfDs are derived
from human epidemiological studies or animal studies to which uncertainty factors
have been applied (e.g., to account for the use of animal data to predict effects
on humans). The RfDs used in this evaluation and the reference used for each
contaminant are listed in Table 10.
6.4 Risk Characterization
Human health risks are discussed independently for potential carcinogenic and
non-carcinogenic effects for contaminants because of the different toxicological
endpoints, relevant exposure duration, and methods employed in characterizing
risk. Excessive exposure to all contaminants can potentially produce non-
carcinogenic health effects while the potential for carcinogenic effects is limited
to exposure of those contaminants categorized as carcinogens.
At the present time, potential exposure to groundwater has been eliminated, only
the potential for future exposure was evaluated. Therefore carcinogenic and
noncarcinogenic risks were evaluated only for future residents.
Potential risks were addressed for groundwater based on the upper 95%
confidence limit (UCL) of the mean and using a Reasonable Maximum Exposure
(RME) dose.
6.4.1 Carcinogenic Risks
For carcinogens, risks are estimated as the incremental probability of an individual
developing cancer over a lifetime as a result of exposure to the carcinogen.
Excess life-time cancer risk is calculated from the following equation:
Risk = GDI xSF
where:
risk = a unit less probability (e.g., 2x1 CT6) of an individual developing cancer;
GDI = chronic daily intake averaged over 70 years (mg/kg-day); and
SF = slope factor, expressed as (mg/kg-day)"1
These risks are probabilities that are generally expressed in scientific notation. An
excess lifetime cancer risk of 1x10"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 70-year lifetime under the
specific exposure conditions at the Site.
The combined exposure of a child and an adult was considered to calculate the
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Table 10
HEALTH CRITERIA
FOR CONTAMINANTS IN THE
SURFICIAL AND CASTLE HAYNE AQUIFERS
CHEMICAL
ORGANICS
Aaetone
Benzene
Cbbrobenzene
wbkoroiorcD
I.I - Dicfabroeibylene
1 .2- Dicbtoroeihykne
Etbvlbenzene
2 - Metbylrupbtha lene
NapainaMne
Teiracbbroetbylene
Toluene
l.l.2-Tr«hloroelbane
Tnah loroettayfene
VmylChkx-idc
\vknet (Toul)
INORGANICS
Arsenic
JBarum
1 Chromium 1 1 1
|l Chromium V !
i C oeau
|Lad
Oral
Slope Factor
(ms/kg/day)'1
NTV
2.90E-02 b
NTV
6. 106 -03 b
6.006-01 b
NTV
NTV
NTV
NTV
5.206-02 i
NTV
S. 706 -02 b
1.10E-02 g
1.906*00 c
NTV
1.75£*00 t
NTV
NTV
NTV
NTV
NTV
Oral
Reference Dose
(mg/Kg'day)
t.ooe-oi b
l.OOE-03 t
2.00E-02 b
i.ooE-02 b
9 .006 -03 b
z.ooe-o: b.m
l.OOE-01 b
4.00E-02 l
4.00E-02 c
l.OOE-02 b
2.00E-01 b
4.00E-03 b
6.00E-V.3 b
1.306-03 t
2.00E+00 b
3.00E-O4 b
7.0CE-02 b
1 .006*00 b
S.OOE-03 b
1.606-01 t
9406-04 td
Inhalation
Slope Factor
(ms^j/iiy)"'
NTV
;.»OE-O: b
NTV
8.0SE-02 b
1.75E-01 b
NTV
NTV
NTV
NTV
2.006-03 g
NTV
5.78E-OS b
6.006-03 |
3.006-01 c
NTV
NA
NA
NA
NA
NA
NA
Inhalation
Reference Dose
(mtAgCday)
l.OOE-01 i
1.006-03 |
2.006-02 1
l.OOE-02 |
9.00E-03 |
2.006-02 |
2.ME-01 b.n
3706-04 i
3.706-04 (ji
l.OOE-02 i
U4£-01 c
4.006-03 |
6.00E-03 )
1.30E-03 ]
2.006*00 |
NA
NA
NA
NA
NA
NA
Dermal
Slope Factor
(mg/kr/dayr1
NTV
3.22E-02 v
NTV
6.78E-03 v
6.67E-01 v
NTV
NTV
NTV
NTV
S.78E-02 v
NTV
4.33E-02 v
1.22E-02 y
2.11£*00 v
NTV
3.506*01 i
NTV
NTV
NTV
NTV
NTV
Dermal
Reference Dose
(rng'tf-day)
9.006-0: v
900E-04 v
i.soe-o: .
9006-03 v
8.106-03 v
I.SOE-O: v
9.006-0: 1
:.OOE-O: »
2.00E-02 iv
9.00E-OJ %
1.80E-01 v
3.406-03 v
5. 406 -03 v
LITE -03 v
1.806*00 v
l.SOE-OS i
3.506-03 i
S. 006 -02 .
2.506-04 i
8.006-03 i
4 706 -OS i
RfD lor napnthjlene w»j uied
IRIS Iw:
MhAST !•«:
KP.\. Rtf,,xi [\MOQ:
LjiojUieD from me uni! rut fjaor
f ECAO. 1992C
8 ECAO. 1992J
b-ECAO. 1992b
k derived: j«e Subsection 7.1J.8 for dcmatun
l-HEAST-.I»92-Ahem»liveoi«bo
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carcinogenic risk for the future resident using groundwater from the Surficial
aquifer and the Castle Hayne aquifer. Carcinogenic risks were calculated for
each chemical through each exposure route using lifetime Reasonable Maximum
Exposure doses (RME). For the Surficial aquifer, the total RME carcinogenic risk was
9.47x10'3. The majority (86.4%) of the total risk in the Surficial aquifer was due to
the ingestion of groundwater, with a 7.7% of the risk contributed by inhalation
while showering and 5.9% contributed by dermal contact while showering. The
chemicals which contributed to the total RME carcinogenic risk are listed in
Table 11.
For the Castle Hayne aquifer, the total RME~carcinogenic risk was 4.12X10"4. As in
the Surficial Aquifer, the majority of the total risk in the Castle Hayne aquifer
(92.9%) was due to the ingestion of groundwater, with 3.1% of the risk contributed
by inhalation while showering and 4.0% contributed by dermal contact while
showering. The chemicals which contributed to the total RME carcinogenic risks
in the Castle aquifer are listed in Table 12.
In summary, the route of exposure contributing the majority of carcinogenic risk
was ingestion of groundwater. The carcinogenic risk for the Castle Hayne aquifer
was one order of magnitude (23 fold) lower than the respective cancer risks for
the Surficial aquifer.
6.4.2 Noncarcinogenic Risks
The potential for noncarcinogenic effects is evaluated by comparing an exposure
level over a specific 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). By adding the HQs for all contaminants 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) can be
generated.
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 exposure
period (i.e., chronic, sub-chronic, or short-term)
To evaluate the noncarcinogenic health effects for the adult resident using
groundwater from the Surficial aquifer, RME hazard quotients and indices for each
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Table 11
CHEMICALS OF CONCERN CONTRIBUTING TO THE TOTAL
RME RISK IN THE SURFICIAL AQUIFER
Chewed!
Tetrachloroethene
4.86E-03
Ingestion
Vinyl Chloride
3.65E-03
Ingestion
Trichloroethene
1.83E-04
Ingestion
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Table 12
CHEMICALS OF CONCERN CONTRIBUTING TO THE TOTAL
RME CARCINOGENIC RISK IN THE CASTLE HAYNE AQUIFER
. ?s .•&. s %> X * s'
V S •, ^ V,\ f s f
• j$t& ^ 4-^v
/ilH0l\^ |s^>^\5
Trichloroethene
7.25E-06
Inhalation
Tetrachloroethene
6.23E-06
Ingestion
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chemical were calculated. The cumulative hazard index using the RME is 49.6,
and the chemicals of concern which exceed a hazard quotient of 1.0 are
presented in Table 13. The results show a potential for adverse noncarcinogenic
health effects to occur in a future adult resident.
For a child using groundwater from the Surficial aquifer, the cumulative hazard
index is 115. This index was calculated using the upper 95% confidence limit
concentrations and the RME. The chemicals of concern which exceed a hazard
quotient of 1.0 using the upper 95% confidence limit are listed in Table 14. The
results show a potential for adverse noncarcinogenic health effects to occur to
a future child resident.
The majority of the hazard index for an adult and for a child, based on upper 95%
confidence limits concentrations, is due to groundwater ingestion, followed by
inhalation and dermal contact while showering.
The cumulative RME hazard index for the adult resident using groundwater from
the Castle Hayne aquifer is 3.5. The majority (67%) of the hazard index is due to
groundwater ingestion, 30% is due to dermal absorption while showering, and
2.7% is due to inhalation while showering.
For a child resident, the cumulative RME hazard index using groundwater from the
Castle Hayne is 8.11. The majority (67.5%) of the hazard index is due to
groundwater ingestion, 30.3% is due to dermal contact while showering, and 2.7%
is due to inhalation while showering.
In summary, the route of exposure which contributed the majority of the
noncarcinogenic risk was ingestion of groundwater. As with carcinogenic risk, the
noncarcinogenic risk for the Castle Hayne aquifer was an order of magnitude
lower than non-cancer risk for the Surficial aquifer.
6.5 Ecological Considerations
The U.S. Department of the Interior, Fish and Wildlife Service lists three threatened
species in Onslow County. These include the American alligator, the green sea
turtle, and the loggerhead sea turtle. In addition, it lists six endangered species
in Onslow County. These include the red-cockade woodpecker, the rough-
leaved loosestrife, Cooley's meadowrus, the Eastern cougar, the leatherback sea
turtle, and the Kemp's Ridley sea turtle.
The Initial Assessment Study of Marine Corps Base, Camp Lejeune, North Carolina,
April 1983, lists additional threatened species at the Base, which is south of the dry
cleaning facility. These include the Venus Flytrap, and Yellow, Sweet, Hooded,
and Flytrap Pitcher Plants. The study also lists the Brown Pelican as an
endangered species.
There are no habitat areas of high quality in the immediate vicinity of the Site.
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Table 13
CHEMICALS OF CONCERN EXCEEDING A HAZARD QUOTIENT (HQ) OF 1
FOR AN ADULT USING THE SURFICIAL AQUIFER
.Chernbaf >
\"^ '
Tetrachloroethene
Trichloroethene
Vinyl Chloride
1 ,2 Dichloroethene
1 Hazard *
Quotient ,
31.4
6.6
4.7
3.7
1 Primarily ixpbkire
1 ^ feute r , ^'^ *
:rt •• ' •• % •• ••
Ingestion and inhalation
Ingestion and inhalation
Ingestion and inhalation
Ingestion and inhalation
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Table 14
CHEMICALS OF CONCERN EXCEEDING A HAZARD QUOTIENT (HQ) OF 1
FOR A CHILD USING SURFICIAL AQUIFER
-' €b&K%X& t *
Tetrachloroethene
74.2
Ingestion and inhalation
Trichloroethene
15.3
Ingestion and inhalation
Vinyl Chloride
10.9
Ingestion and inhalation
1 ,2 Dichloroethene
7.75
Ingestion and inhalation
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The Site includes several commercial and residential buildings, paved roads and
paved parking areas, and areas of mowed grassy fields and small stands of pine
trees. This configuration inhibits the formation of habitat areas, as it is completely
developed. Given the nature of the ABC One-Hour Cleaners Site, it is unlikely that
the Site would attract any of the threatened or endangered species described
above.
Additional information regarding known critical habitats and species of special
concern were accumulated through a review of the National Heritage Program
database. Results of this database review failed to identify any critical habitats
within a 3-mile radius of the Site. The only species of special concern identified
within 3 miles of the Site was the American alligator, which were spotted in 1987
in Scales Creek, approximately 2-miles southwest of the Site. Given that the
ecological setting of ABC Site is primarily an urban/residential community, that
little suitable wildlife habits have been identified in the area, and that the major
contaminant pathway of concern (groundwater migration) does not appear to
have impacted any wetland communities, it is doubtful that contamination from
this Site would pose a potential for adverse effects to the ecological environment.
Based on these observations and assumptions, an ecological risk assessment for
Operable Unit #1 was not conducted. The Ecological Risk Assessment for the ABC
Site will be included in the Operable Unit #2.
6.6 Risk Uncertainty
There is a generally recognized uncertainty in human risk values developed from
experimental data. This is primarily due to the uncertainty of data extrapolation
in the areas of (1) high to low dose exposure, (2) modeling of dose response
effects observed, (3) route to route extrapolation, and (4) animal data to human
experience. The Site-specific uncertainty is mainly due to the degree of accuracy
of the exposure assumptions.
In the presence of such uncertainty, the EPA and the risk assessor have the
obligation to make conservative assumptions such that the chance is very small
for the actual health risk to be greater than that determined through the risk
process. On the other hand, the process is not to yield absurdly conservative risk
values that have no basis in reality. That balance was kept in mind in the
development of exposure assumptions and pathways and in the interpretation of
data and guidance for this baseline risk assessment.
7.0 DESCRIPTION OF REMEDIAL ALTERNATIVES
The following remedial alternatives were selected for evaluation:
* Alternative 1: No-Action
* Alternative 2: Institutional Controls
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* Alternative 3: Groundwater Recovery By Extraction Wells
and Treatment By Air Stripping
* Alternative 4: Groundwater Recovery By Downgradient
Interception Wells and Treatment By Air
Stripping
Common Features of the Alternatives
Castle Hayne Aquifer
The vertical extent of contamination has not been thoroughly defined. Several
more wells will be installed and sampled in the Castle Hayne aquifer during the
investigation of the soil contamination in Operable Unit #2 to better define the
contamination at this depth. The results of this investigation will be used in the
design of the extraction systems described in alternative 3 and 4.
Institutional Controls
All alternatives, except No Action, include institutional controls such as deed
restrictions, local ordinances or record notices applied as appropriate for long-
term management and prevention of exposure to contaminants.
Treated Groundwater Discharge
Alternatives 3 and 4 generate treated ground water which must be discharged.
The discharge will be released to Northeast Creek via a National Pollutant
Discharge Elimination System (NPDES) permit.
Site Monitoring
While wastes remain at the ABC Site, CERCLA requires that monitoring data
collected from the Site be evaluated every five years. This evaluation would
include spatial and temporal analysis of existing data to determine increasing,
decreasing, or stationary trends in contaminant concentrations. The result of this
evaluation would be used to reassess the need to maintain, increase or decrease
the number and types of samples and analysis required for monitoring, and the
need to change the remedial response at the Site.
Existing Controls
Back to 1985, Tarawa Terrace community was connected to an emergency water
supply line and disconnected from the contaminated wells TT-25 and TT-26. The
emergency water supply line was built from the Holcomb Boulevard water supply.
This arrangement is active to date, and according to the Base authorities, the
Holcomb Boulevard treatment plant meets the full water supply demand of the
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community. At a minimum, the Tarawa Terrace community will remain on this
water supply system until remediation of the aquifers are complete.
Groundwater Modeling
The groundwater model FLOWPATH was used to develop conceptual design
scenarios for groundwater extraction. The following parameters were used
as site-specific input parameters in the groundwater model for alternatives 3 and
4:
Number of extraction wells 5 (Alternative 3)
2 (Alternative 4)
Groundwater extraction rate per well 100 gpm
Aquifer type Unconfined
Aquifer thickness 150ft
Hydraulic conductivity of the aquifer 12.15 ft/day
Porosity of soil 0.125
Retardation factor 6.82
Time period for capture zone simulation 7 yrs (Alternative 3)
40 yrs (Alternative 4)
Some of these parameters could change after the extent of groundwater
contamination in the Castle Hayne aquifer is determined, and the aquifer test
results are obtained. The final number and location of extraction wells may be
revised during the remedial design to include the additional information regarding
the extent of contamination in both aquifers.
7.1 Alternative 1: No Action
CERCLA requires that the 'No Action1 alternative be considered at every site
against which the other alternatives are evaluated. Under this alternative no
action would be taken.
The only reduction of contaminant levels in Site groundwater would occur through
natural processes. The time for groundwater contaminant levels to drop below
NCGWQS and/or MCLs is on the order of several thousand years. This alternative
leaves the volume of hazardous substances unchanged, and there is potential for
an increase in volume of impacted environmental media - groundwater.
Because contaminated groundwater would remain in place, untreated, at the
Site, CERCLA requires that data be collected and evaluated at least every five
years to assure that a selected remedy continues to be protective of human
health and the environment. Therefore, selected Site groundwater monitoring
wells would be sampled for Volatile Organic Compounds (VOCs). Based upon
the findings of the review, EPA may determine other studies and/or actions should
be taken.
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This alternative has no capital costs. , The present worth cost of the five years
review program is $140,000.
7.2 Alternative 2: Institutional Controls
As with the No Action alternative, no active remediation would be conducted
under this alternative. However, institutional measures would be taken to prevent
exposure to contaminated groundwater. The institutional controls include well
installation/well permit restrictions, alternate water supply to affected residents,
and groundwater monitoring.
Well installation/well ^ermii restrictions involve development of restricted
groundwater management zones downgradient of the ABC Site based upon
groundwater monitoring data. A "no well' zone would be delineated within which
groundwater does not meet drinking water standards without treatment. In the
'no well1 zone, well installation would be restricted by the State or by use of the
weli permit system. Implementation of "no well" zone may be facilitated if the
plume remains confined to a few commercial properties near the Site and Camp
Lejeune.
Under this alternative, groundwater would be monitored semi-annually for 5 years
at the existing ten Surficial wells and five Castle Hayne aquifer wells. By that time,
it is assumed the plume will have migrated beyond the furthest downgradient
monitoring well. Six more downgradient wells will be installed after 5 years to
track the migration pattern of the plume and the concentration of the
contaminants as the plume expands. The number of wells may be increased
based upon the sampling results of the existing monitoring wells and/or newly
installed monitoring wells. Thereafter, the existing and new wells will be monitored
semi-annually. The locations of the new wells will be based upon the results of
sampling the existing monitoring wells over the first 5 year period.
The total estimated present worth cost for this alternative is $ 1,283,900. The capital
costs associated with this alternative include the installation of five monitoring
wells after 5 years. The O&M costs include long-term monitoring activities, which
have been evaluated for an indefinite period of time.
7.3 Alternative 3: Groundwater Recovery By Extraction Wells and Treatment
By Air Stripping
In this alternative, groundwater would be extracted using extraction wells located
along the center line of the plume. The exact number and location of extraction
wells as well as the necessity of a off-gas treatment system would be determined
during Remedial Design (RD). The actual depth of contamination has not been
defined at this time, but will be evaluated as part of the Operable Unit 2. Each
extraction well would be screened throughout the anticipated saturated zone of
the wells under pumping conditions. Recovered water would be treated by an
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ABC Site
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Table 15
GROUNDWATER CLEANUP LEVELS
l??viJi/;y^^
U? \,;V'* C;L ^>I!j
'"" . . .^ . . .^ * .% .< .^§ ^
Tetrachloroethene
Trichloroethene
1-2 Dichloroethene
Vinyl chloride
^ ' " " •>. • : '5
r^UvSSfJT?:
^ . ..vtiWflfAx-^
1.0
2.8
70.0
1.0
^p6iitM>;
s •. •*• <.x-^ /«,W^^ ^ -vkCvw*
^W^^>
, - s%\ --.^
JfV-i \ ^s v*^ Xv^ ^«. ^wfev/
Entire
contaminant
plume
Entire
contaminant
plume
Entire
contaminant
plume
Entire
contaminant
plume
^r ^C'"^^
^T^V^' -.^<\
V
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above ground treatment system via air stripping and if needed, the use of an off-
gas treatment system. The treated water would be discharged to Northeast
Creek loccited approximately one-half a mile from the air stripper, through a
pipeline. The point of compliance would be the entire contaminated plume and
the groundwater would be extracted and treated until the remedial goals
(cleanup levels. Table 15) are achieved.
In the air stripping system, the groundwater is pumped from the well and sent to
the top of an air stripping tower. While the water cascades down through a large
tube, a high-powered fan blows the contaminants from the water. The fan then
sends the contaminated air out of the top of the air stripping tower. If needed,
the volatilized contaminants are treated by an off-gas system. The air stripping
system is most effective in removing VOCs.
The well installation/well permit restrictions described for Alternative 2 would be
included in this alternative as well. A groundwater monitoring program would be
conducted to assess the changes in concentrations of the contaminants.
The present worth cost for this alternative, based on the placement of 5 extraction
wells, has been estimated to be $2,262,900. This cost is estimated for an
anticipated 7-years of cleanup.
7.4 Alternative 4: Groundwater Recovery By Downgradient Interception
Wells and Treatment By Air Stripping
In this alternative, groundwater would be extracted from interception wells
located downgradient of the plume. The purpose of installing the downgradient
wells is to capture the plume at the anticipated downgradient edge considering
anticipated migration of the plume between the time of data collection and the
start-up of groundwater remediation system. The point of compliance for this
alternative would be the entire contaminated plume and the groundwater would
be extracted and treated until the remedial goals (cleanup levels. Table 15) are
achieved.
As stated in Alternative 3, the depth of contamination would be further defined
as part of Operable Unit 2 and the necessity of an off-gas treatment system would
be determined in the Remedial Design phase. Each extraction well would be
screened throughout the entire anticipated saturated thickness of the wells under
pumping conditions. Recovered groundwater would be treated by an above
ground treatment system via air stripping and if needed the use of an off-gas
treatment system. The treated water would be discharged to Northeast Creek
located approximately one half mile from the air stripper, through a pipeline. The
well installation/well permit restrictions described in Alternative 2 would be
included in this alternative as well. A groundwater monitoring program would be
conducted to assess the changes in concentrations of the contaminants.
The present worth cost for Alternative 4 has been estimated to be $3,249,600.
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8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
A detailed comparative analysis using the nine evaluation criteria set forth in the
NCR was performed on the four remedial alternatives developed during the FS.
The advantages and disadvantages were compared to identify the alternative
with the best balance among these nine criteria.
8.1 Threshold Criteria
8.1.1 Overall Protection of Human Health and the Environment
Section 8.1.1 addresses whether or not a remedy provides adequate protection
and describes how risks are eliminated, reduced, or controlled through treatment,
engineering controls, or institutional controls.
All alternatives except for the "No Action1 alternative, would be protective of
human health and the environment. The "No Action" alternative is not protective
because it would not prevent unacceptable risk from ingestion or inhalation of
groundwater. There is uncertainty related to the Institutional Control alternative
on how this, alternative would continue to protect human health and the
environment over a long period of time. Both alternatives 3 and 4 would be
effective removing the contaminants from the groundwater and thus these
alternatives would be protective to human health and the environment.
Since the "No-Action" alternative does not eliminate, reduce, or control any of the
exposure pathways, it is therefore not protective of human health and the
environment and will not be considered further in this analysis.
8.1.2 Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs)
Section 8.1.2 addresses whether or not a remedy will meet all of the applicable
or relevant and appropriate requirements of other Federal and State
environmental statutes and/or provide grounds for a waiver. The identified ARARs
for this Site are listed in Section 9.2.
Alternatives 3 and 4 would reduce the levels of contaminants in the groundwater
and comply with Federal and State ARARs.
Alternative 2 would not be in full compliance with all Federal and State ARARs.
8.2 Primary Balancing Criteria
8.2.1 Long-Term Effectiveness and Permanence
Subsection 8.2.1 refers to expected residual risk and the ability of a remedy to
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maintain reliable protection of human health and the environment over time,
once cleanup levels have been met. This criterion includes the consideration of
residual risk and the adequacy and reliability of controls.
Both alternatives 3 and 4 afford the highest degree of long-term effectiveness
because all of the contaminated groundwater would be treated to levels
protective of human health and the environment. The remedial action objectives
for preventing further contamination would be quickly achieved through
implementation of extraction wells. These wells would provide assurance that
containment of the entire contaminant plume is adequate.
With Alterative 2, remedial action objectives would not be met through natural
attenuation processes in the foreseeable future. Therefore, the magnitude of the
potential risks remaining at the Site after many years may still exceed acceptable
levels, and would only be mitigated by continued diligence in tracking plume
migration and restricting water use.
8.2.2 Reduction of Toxicity, Mobility, or Volume Through Treatment
This subsection refers to the anticipated performance of the treatment
technologies'a remedy may employ.
Alternatives 3 and 4 would accomplish a reduction in toxicity, mobility, and
volume. The alternatives would reduce the toxicity by volatilization of VOCs from
the groundwater. Mobility would be reduced once the extraction wells were
installed. These extraction wells would prevent the plume from spreading. The
volume of the VOCs would be reduced as the treatment progresses. Both
alternatives 3 and 4 provide for destruction of air emissions out of the air stripper,
if warranted, through properly selected, designed, and operated emission
controls.
Alternative 2 would not provide reduction in toxicity or mobility in the foreseeable
future. Overall volume of the contaminated groundwater may increase with the
downgradient migration of the plume.
8.2.3 Short-Term Effectiveness
Short-term effectiveness refers to the period of time needed to complete the
remedy and any adverse impacts on human health and the environment that
may be posed during the construction and implementation of the remedy until
cleanup levels are achieved.
Alternative 3 would require approximately 7 years to remediate the groundwater
to ARARs.
Alternative 4 would require approximately 40 years to remediate the groundwater
to ARARs. This alternative would require a long period of time for the cleanup
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because the contaminants located at the up-gradient edge of the plume are
required to travel the entire length of the plume to reach one of the extraction
wells.
For both of these alternatives (3 and 4), adequate protection would be provided
to the workers and to the community during the remedial actions. The
alternatives protect the community and workers by reducing the contaminants
in groundwater and air (through the use of emission controls on the air stripper if
warranted).
In Alternative 2, a significant reduction of contaminant concentrations would not
be expected. Without a treatment system, the plume would be allowed to
migrate further and contaminate other water resources. Therefore, Alternative 2
is not considered to be an effective remedial solution. The risk to on-site workers
under this alternative is minimum.
8.2.4 Implementability
Implementability is the technical and administrative feasibility of a remedy,
including the availability of materials and services needed to implement the
chosen solution.
Alternative 2 is easily implemented using existing technology.
For alternatives 3 and 4, groundwater containment/air stripping measures are
extremely common and widely available. Monitoring groundwater and its
restoration should not pose extraordinary problems.
Alternative 4 would only require two extraction wells that could be placed on the
same property eliminating substantial logistical problems with access.
Alternative 3 would require the extraction wells (and the treatment system) to be
placed off-site on multiple properties, and the installation of pipelines across
railroad tracks and major roads which could cause access problems.
8.2.5 Cost
The total Present Worth Costs for the alternatives evaluated are as follows:
Alternative 1: $ 140,000
Alternative 2: $1,283,900
Alternative 3: $ 2,262,900
Alternative 4: $ 3,249,600
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8.3 Modifying Criteria
8.3.1 State Acceptance
EPA and the North Carolina Department of Environment, Health, and Natural
Resources (NCDEHNR) have cooperated throughout the RI/FS process. The State
has participated in the development of the RI/FS through comment on each of
the various reports developed by EPA, and the Draft ROD and through frequent
contact between the EPA and NCDEHNR site project managers. EPA and
NCDEHNR are in agreement on the selected alternative. Please refer to the
Responsiveness Summary which contains a letter of concurrence from NCDEHNR.
8.3.2 Community Acceptance
EPA solicited input from the community on the Proposed Plan for clean-up of the
ABC Site. Although public comments indicated no specific opposition to the
preferred alternative, some local residents express their concerns during the
Proposed Plan public meeting. Please see the Responsiveness Summary which
contains a transcript of the public meeting.
9.0 THE SELECTED REMEDY
Based upon consideration of the CERCLA requirements, the detailed analysis of
the alternatives using the nine criteria, and public comments, both EPA and
NCDEHNR have determined that Alternative 3 is the most appropriate remedy for
the ABC One-Hour Cleaners Site in Jacksonville, North Carolina.
The selected remedy shall include the following: (1) the installation of extraction
wells to contain and extract the contaminated groundwater with an above
ground treatment system via air stripping; and (2) institutional controls placed on
well construction and water use in the general area of the Site.
It is estimated that the present worth cost of the selected remedy will be
approximately $2,262,900. This is based on 7 years of pump and treat of the
groundwater. Itemized breakdowns of capital and Operation and Maintenance
costs for Alternative 3 are presented in Table 16 and 17.
Alternative 3 will permanently reduce the risk of exposure to contaminants in
groundwater and will also prevent further contamination to the environment.
9.1 Performance Standards
(1) Groundwater Recovery by Extraction Wells and Treatment by Air Stripping
Extraction wells and pumping systems will be installed to extract contaminated
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Table 16
ESTIMATED CAPITAL COSTS FOR THE SELECTED REMEDY
Item
1
2
3
4
Description
Predesign Study
• Installation of monitoring wells
• Installation of pumping well
• Conduct a 72-hr pump test
• Groundwater sampling (21 monitoring
wells, 4 supply wells, 4 Base tank farm
wells, 1 field blank, 1 duplicate, 1 MS,
and 1 MSD). Cost includes labor.
expenses.
• Revise groundwater model
Permits/ Approvals (assuming no air permits are
needed)
Installation of groundwater extractor wells (4
additional), and pumps, flow meters, valves, well
heads, and riser pipes for all 5 wells.
Piping system for transport of recovered
groundwater from the extraction wells to the air
stnpper
• . Pipeline including excavation, bedding,
and backfill
• Railroad and road crossings
Quantity
6
1
S
1800ft
Unit Cost
($)
variable
15,000
lump sum
lump sum
lump sum
lump sum
variable
16.50/ft
lump sum
Total cost
($)
68.000
15,000
20.000
30,000
23,100
15.000
70,000
29,700
85,100
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Table 16 (continued)
ESTIMATED CAPITAL COSTS FOR THE SELECTED REMEDY
Item
5
6
7
g
9
10
11
Description
Installation of the air stripper
• Air stripper, including blower and
ductwork
• Electrical work, instrumentation/ controls
• Prefabricated structure for the air stripper
Piping system for transport of treated water from
the air stripper to Northeast Creek
• Discharge pump, controls, and associated
electrical work
• Pipeline including excavation, bedding.
and backfill
• Local road crossings
Miscellaneous costs
• Foundations and related cast in place
concrete work
• Electrical heat tracing and freeze
protection
• Area lighting and power to prefabricated
structure
• Insulation as required, allowance
• Painting and coatings, as required,
allowance
• Paving and other site development costs
Subtotal
management (22%)
Engineering design (20%)
Overhead and profit (15%)
Contingency (25 %)
Total
Quantity
2500ft
Unit Cost
($)
lump sum
lump sum
lump sum
lump sum
16.50/ft
lump sum
lump sum
lump sum
lump sum
lump sum
lump sum
lump sum
Total cost
($)
55,000
14,000
10,000
12,100
49,600
10,000
13,000
8,500
4,800
3,500
2,800
10,000
549,200
120,800
109,800
82,400
137,300
999,500
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Table 17
ESTIMATED OPERATION AND MAINTENANCE COSTS FOR THE SELECTED REMEDY
Item
I
2
3
4
5
6
7
Description
Labor (3 % of the capital
cost)
Maintenance (2% of the
capital cost)
Air stripper effluent
monitoring (weekly)
Utilities
Groundwater monitoring
• Analysis (26 wells, 1
field blank, 1 duplicate,
1 MS, and 1 MSD).
First 2 years quarterly,
3-7 years semi-annuaily.
• Labor (sampling)
• Labor (report
preparation)
• Other expenses
Subtotal
Administrative costs (15%)
Subtotal
Contingency (25%)
Total
Annual
Quantity
(yrs 1-2)
52
120
4
4
Annual
Quantity
(yrs 3-7)
52
60
2
2
Unit Cost ($)
lump sum
lump sum
250/sample
lump sum
250/sample
10,0007
sampling event
3,0007
sampling event
lump Slim
lump sum
lump sum
Total
Cost/yr
(yrs 1-2)
($)
30,000
20,000
13,000
27,200
.-*
30,000
40,000
12,000
10,000
182,200
27,300
209,500
52,400
261,900
Total
Cost/yr
($)(yrs
3-7)
30,000
20,000
13,000
27,200
15,000
20,000
6,000
5,000
136,200
20,400
156,600
39,100
197,700
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groundwater from both aquifers and restore the aquifers to within the cleanup
levels established by this ROD. EPA will determine the final number and location
of extraction wells for the Site. The extracted groundwater will be treated using
an above ground treatment system via air stripping. The total quantity of VOC
in the air emissions are estimated to be 17.9 Ibs/day at design conditions. The
present state guidelines allow discharge of up to 40 Ibs/day without treatment.
Accordingly, no emission control is required for the air stripper as per the state
guidelines (15A NCAC 2D.0518). In the event the air exhaust will not meet the
state guidelines of 40 Ibs/day, then the air will be treated through Granular
Activated Carbon (GAC), thermal treatment, or photolytic oxidation before it is
released into the atmosphere.
The treated water will be pumped to a discharge location. Discharge will be
directly into Northeast Creek via a National Pollutant Discharge Elimination System
(NPDES) permit. If in the future, the City of Jacksonville increases their capacity
then the alternative to discharge to the local publicly owned wastewater
treatment works (POTW) will be evaluated.
The groundwater extraction system will continue to operate until cleanup levels
for the contaminants of concern are reached throughout the contaminant
plume.
The Surficial and Castle Hayne aquifers will be treated until the cleanup levels for
the contaminants as listed in Table 15 are attained.
Additional monitoring wells will be installed as part of the Operable Unit #2
investigation, to better define the vertical extent of groundwater contamination.
The sampling frequency, number, and location of the extraction wells, and the
location of additional monitoring wells needed will be designated during the
Remedial Design (RD).
The goal of this remedial action is to restore the Surficial and Castle Hayne
groundwater to its beneficial use, which is, for drinking water. Based on
information obtained during the Rl and on a careful analysis of all remedial
alternatives, EPA and NCDEHNR believe that the selected remedy will achieve this
goal. It may become apparent, during implementation or operation of the
groundwater extraction systems, that contaminant levels have ceased to decline
and are remaining constant at levels higher than the remediation levels. In such
a case, the system performance standards and/or remedy will be reevaluated.
The selected remedy will include groundwater extraction for an estimated period
of 7 years, during which the system's performance will be carefully monitored on
a regular basis and adjusted as warranted by the performance data collected
during operation. Adjustments to the operating system may include:
a) discontinuing operation of extraction wells in areas where cleanup levels have
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been attained;
b) alternating pumping at wells to eliminate stagnation points; and
c) pulse pumping to allow aquifer equilibration and encourage adsorbed
contaminants to partition into groundwater.
To ensure that cleanup levels continue to be maintained, the aquifer will be
monitored at those wells where pumping has ceased on an occurrence of at
least every 5 years following discontinuation of groundwater extraction.
All extracted groundwater shall be treated to levels which allow for discharge to
surface water: Northeast Creek. All groundwater discharge actions shall comply
with Federal and State discharge requirements.
As stated previously all air emissions from the air stripper shall be in compliance
with Federal and State Clean Air Act (CAA) standards. Off-gas emissions, if
determined necessary during RD, will be controlled by Granular Activated Carbon
(GAC), thermal treatment, or photolytic oxidation.
(2) Institutional Controls Placed on Well Construction and Water Use In the
General Area of the Site
As necessary, institutional controls will be placed on well construction in the
general area of the Site. No well will be located, constructed, or operated which
results in the diminution of the extraction wells at the ABC One-Hour Cleaners Site
or in the degradation of the Surficial or Castle Hayne aquifers. Institutional
controls would also restrict the use of groundwater containing, or potentially
containing, levels or contamination in excess of MCLs and NCGWQS. Institutional
controls may include deed restrictions, record notice, or some other appropriate
measures. The controls shall remain in effect until EPA determines through
monitoring that the cleanup levels have been attained.
9.2 Site specific ARARs
Chemical-Specific ARARs:
Clean Water Act (CWA) Water Quality Criteria (CWA Part 303; 40 CFR Part 131)
establishes water quality criteria based on the protection of human health and
aquatic life.
Safe Drinking Water Act (SDWA) National Primary Drinking Water Standards (40
CFR Part 141) establishes health-based enforceable standards (maximum
contaminant levels (MCLs)) for public water system.
SDWA National Secondary Drinking Water Standards (40 CFR Part 143) establishes
aesthetic-based, non-enforceable guidelines (secondary maximum contaminant
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levels (SMCLs)) for public water systems.
SDWA Maximum Contaminant Levels Goal (MCLG) (40 CFR Part 141) establishes
non-enforceable drinking water quality goals (MCLGs) set at levels of no known
or anticipated adverse health effects. The MCLGs are based on an adequate
margin of safety without consideration of available treatment technology or cost.
NC Drinking Water and Groundwater Standards; Groundwater Classifications and
Standards (NCAC Title 15 Chapter 2, Subchapters 2L.0200 and 0.0201) establishes
groundwater and drinking water standards based on usage.
NC Surface Water Quality Standards (NCSWQS) Classification and Water Quality
Standards (NCAC Title ISA Chapter 2, Subchapters 2L.0100 and 2L.0200)
establishes a series of classifications and water quality standards for surface
waters.
NCSWQS Technology-Based Effluent Limitations (NCAC Title ISA Chapter 2,
Subchapter 2B.0400) establishes guidelines for effluent limitations based on the
Best Available Technology (BAT) economically achievable.
NC Air Pollution Control Regulations (NCAPCR) (NCAC Title 15A Chapter 2,
Subchapter 2D.0518) permit requirements for VOC emissions from air strippers.
Location-Specific ARARs:
There are no location-specific ARARs.
Action-Specific ARARS:
CWA National Pollutant Discharge Elimination System (NPDES) Requirements (CWA
Part 402; 40 CFR Part 125) requires a permit for effluent discharge for any point
source into surface waters of the United States.
CWA National Pretreatment Standard for Indirect Discharge to a POTW (CWA Part
307(b); 40 CFR Part 403) establishes standards to control pollutants which pass
through or interfere with treatment processes in public treatment works which may
contaminate sewage sludge.
CWA Technology-Based Effluent Limitations (CWA Part 301(b)) establishes
guidelines to determine effluent standards based on the BAT economically
achievable.
NC Water and Air Resources Act (General Statutes Chapter 143, Article 2IB)
achieves and maintains a total environment with superior quality (state equivalent
of Federal CWA and CAA).
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NC Drinking Water Act (NCDWA); Regulations on Drinking Water (General statutes
Chapter 130A, Article 10) establishes criteria for protection of state public water
supplies.
NC Water Pollution Control Regulations (NCWPCR) (NCAC Title 15 Chapter 2,
Subchapter 2H) requires permit for discharge of effluent from point sources into
surface waters. State-level version of Federal NPDES program.
NCWPCR Wastewater Treatment Requirements (NCAC Title 15 Chapter 2,
Subchapter 2H.0100) establishes basic wastewater treatment requirements for
effluent discharge.
NC Wells Construction Standards (NCAC Title 15A Chapter 2, Subchapter 2C)
establishes classes of wells and set forth requirements and procedures for
permitting, construction, operation, etc.
NC Air Pollution Control Regulations (NCAPCR) (NCAC Title 15A Chapter 143,
Subchapter 2D.0518) permit requirements for VOC emissions from air strippers.
10.0 STATUTORY DETERMINATIONS
Under CERCLA Section 121, EPA must select remedies that are protective to
human health and the environment, comply with applicable or relevant and
appropriate requirements (unless a statutory waiver is justified), are cost-effective,
and utilize permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable. In addition,
CERCLA includes a preference for remedies that employ treatment that
permanently and significantly reduce the volume, toxicity, or mobility of
hazardous waste as their principal element. The following sections discuss how this
remedy meets these statutory requirements.
10.1 Protection of Human Health and the Environment
The selected remedy protects human health and the environment through
groundwater extraction and treatment via air stripping and institutional controls
placed on well construction and water use in the general area of the Site. Air
stripping will irreversibly remove organic compounds from groundwater. Air
emissions will be controlled, if needed, through properly selected, designed, and
operated emission controls.
No short-term threats are associated with the selected remedy that cannot be
readily controlled. In addition, no adverse cross-media impacts are expected
from the remedy.
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10.2 Compliance with Applicable or Relevant and Appropriate
Requirements
The selected remedy will be in full compliance with all applicable or relevant and
appropriate chemical-, action-, and location- specific requirements (ARARs). A
complete discussion of these ARARs which are to be attained is outlined in
Section 9.2.
10.3 Cost Effectiveness
The selected remedy. Alternative 3, was chosen because it provides the best
balance among criteria used to evaluate the alternatives considered in the
Detailed Analysis. The alternative was found to achieve both adequate
protection of human health and the environment and to meet the statutory
requirements of Section 121 of CERCLA. The selected remedy was found to be
cost-effective when compared to other acceptable alternatives. The present
worth cost of Alternative 3 has been estimated to be $ 2,262,900.
10.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies to the Maximum Extent
Practicable
EPA and NCDEHNR have determined that the selected remedy represents the
maximum extent to which permanent solutions and treatment technologies can
be utilized in a cost-effective manner. Of those alternatives that are protective of
human health and the environment and comply with ARARs, EPA and NCDEHNR
have determined that the selected remedy provides the best balance of trade-
offs in terms of long-term effectiveness and permanence, reduction of toxicity,
mobility, or volume achieved through treatment, short-term effectiveness,
implementability and cost, while also considering the statutory preference for
treatment as a principal element and considering State and community
acceptance.
The selected remedy treats the principal threats posed by groundwater,
achieving significant contaminants reductions. This remedy also provides the most
effective treatment of any of the alternatives considered.
10.5 Preference for Treatment as a Principal Element
By treating the contaminated groundwater by air stripping (and carbon
adsorption if it is necessary), the selected remedy addresses the principal threats
posed by the Site through the use of treatment technologies. By utilizing
treatment as a significant portion of the remedy, the statutory preference for
remedies that employ treatment as a principal element is satisfied.
-------
APPENDIX B
STATE CONCURRENCE
-------
State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Solid Wfaste Management
P.O. Box 27687 • Raleigh, North Carolina 27611-7687
James G. Martin, Governor William L, Meyer
William W. Cobey, Jr., Secretary Director
December 14, 1992
Mr. Luis Flores
Remedial Project Manager
North Superfund Remedial Branch
345 Courtland Street, NE
Atlanta, Georgia 30365
RE: Comments on Draft Record of Decision (ROD)
Operable Unit #1, Groundwater
ABC One Hour Cleaners Site
Jacksonville. Onslow County, NC
NCD 024 644 494
Dear Mr. Flores:
The Draft Record of Decision (ROD) for the ABC One-Hour Cleaners Site,
Operable Unit #\: Groundwater, located in Jacksonville, North Carolina has been received
and reviewed by the North Carolina Superfund Section. This document has also been
forwarded to the NC DEM for concurrent review. Their comments will be forwarded when
available. The following comments are offered by the North Carolina Superfund Section.
1. Declaration For The Record of Decision - Near bottom of page.
"Elimination" was left out of NPDES to the Northeast Creek.
2. Rgures 7 and 8 should be switched. See references to these figures at the top
of pages 6 and 16.
3. Page 22, 2nd paragraph. ..."degradated" is not a word.
4. Page 22, 5th paragraph. Figure 2-3 is not located in the table of contents or
in the body of this report.
An Equal Opportunity Affirmative Action Employer
-------
101 00 '00 00:00 142 p03
Mr. Flores
12-14-92
Page 2
5. Table S (Health Criteria, Contaminants of Concern in Groundwater) is not
legible, especially footnotes.
6. An important aspect of groundwater extraction, which has not been
considered, is possible damage to structures and pavements caused by
foundation settlement resulting from the lowering of the water table within
the vicinity of the proposed extraction wells. Documentation and monitoring
of structural and pavement integrity should be performed before initiation of
groundwater extraction systems and throughout the remedial process.
7. Page 28, section 6.4.2: The term "95% upper hazard quotient" is unclear. Do
you mean a hazard quotient calculated using the upper 95% confidence limit
concentrations?
8. Page 34, second paragraph: It is unclear to the reader what information is
presented in the last sentence.
The North Carolina Superfund Section concurs with the concepts presented in the
Draft Record of Decision (ROD) and the Selected Remedy (Alternative 3), prepared by the
US EPA Region IV, for the ABC One-Hour Cleaners site. Operable Unit #1: Groundwater.
If applicable or relevant and appropriate requirements become evident at any time in the
future, which significantly affect the conclusions or remedy selection contained in the Draft
ROD, the State may modify or withdraw this concurrence with written notice to EPA
Region IV. The State also reserves the right to review, comment, and make independent
assessments of all future work relating to this site.
If you have any questions or comments, please do not hesitate to contact Randy
McElveen or me at (919) 733-2801.
Sincerely,
Jack Butler, PE
Environmental Engineering Supervisor
Superfund Section
RM/dk/abc.nn/14
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I ^ M 3 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
V tC^ REGION IV
*i opo>1
345 COUR^LAND STREET. N E
N*A, GEORGIA 3O3S5
January 14, 1993
Jack Butler
Department of Environment,
Health and Natural Resources
Superfund Section
401 Oberlin Road
Suite 150
Raleigh, North Carolina 27605
RE: North Carolina's Concurrence
Record of Decision (ROD)
Operable Unit #1: Groundwater
ABC One-Hour Cleaners Site
Jacksonville, North Carolina
Dear Mr. Butler:
EPA-Region IV appreciates the State's concurrence on the Record of
Decision (ROD) for the ABC One-Hour Cleaners Site in Jacksonville
North Carolina. EPA would like to respond to the comments submitted
by North Carolina Department of Environment, Health, and Natural
Resources (NCDEHNR) - Superfund Section in your December 14, 1992
correspondence. This response, along with your December 14, 1992
letter, will be included as an Appendix to the ROD. These letters
should stand as official documentation that EPA-Region IV and
NCDEHNR-Superfund Section have agreed in the preferred alternative
at this point in time.
Comment number six, which made reference to the possible damage to
structures and pavements caused by foundation settlement resulting
from the lowering of the water table within the vicinity of the
proposed extraction wells will be considered during the remedial
design. The rest of the comments are reflected in the final
document.
Please contact me at (404) 347-7791 if you have any questions.
Sincerely,
I. Flores '
Project Manager
North Superfund Remedial Branch
cc: Randy McElveen, NCDEHNR
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