United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R04-92/120
September 1992
SEPA Superfund
Record of Decision:
USMC Camp Lejeune Military
Reservation, NC
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NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement, but adds no further applicable information to
the content of the document Ail supplemental material is, however, contained in the administrative record
for this site.
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50272-101
REPORT DOCUMENTATION i. REPORT MO. 2.
PAGE EPA/ROD/R04-92/120
4. THIe and Subtitle
SUPERFUND RECORD OF DECISION
USMC Camp Lejeune Military Reservation, NC
First Remedial Action - Interim
7. Authort*)
». Perfuming Organization Name end Addmu
12. Sponeoring Organization Hum end Addreaa
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
3. Recipient1 a Acceeel on No.
5. Report Date
09/23/92
6.
8. Performing Organization Rept No.
10. Pro|ect/Taak/Work Unit No.
11. CorrtractfC) or Gr*«
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EPA/ROD/R04-92/120
USMC Camp Lejeune Military Reservation, NC
First Remedial Action - Interim
Abstract (Continued)
The selected remedial action for this site includes extracting and pretreating
contaminated ground water using an oil/water separator; treating the water onsite using
precipitation, chemical reduction, and sedimentation to remove inorganics, and air
stripping to remove VOCs; treating emissions using carbon adsorption, based on the
results of a treatability study; discharging the treated water offsite to the Hadnot
Point Sewage treatment plant for ex-situ biological treatment, prior to final onsite
discharge to the New River; transporting the free product to a waste oil recycler or
incinerator offsite; conducting long-term ground water monitoring; and implementing
institutional controls including ground water use restrictions. The estimated present
worth cost for this remedial action is $7,600,000, which includes an estimated annual O&M
cost of $351,500 for 30 years.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific ground water clean-up standards are based on SDWA MCLs and state
standards and include benzene 1 ug/1; TCE 2.8 ug/1; lead 15 ug/1; arsenic 50 ug/1; and
chromium 50 ug/1.
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FINAL
INTERIM REMEDIAL ACTION RECORD OF
DECISION FOR THE SHALLOW AQUIFER
AT THE HADNOT POINT
INDUSTRIAL AREA OPERABLE UNIT
MARINE CORPS BASE, CAMP LEJEUNE,
NORTH CAROLINA
CONTRACT TASK ORDER 0017
Prepared For:
DEPARTMENT OF THE NAVY
ATLANTIC DIVISION
NAVAL FACILITIES
ENGINEERING COMMAND
Norfolk, Virginia
Under the:
LANTDIV CLEAN Program
Contract N62470-89-D-4814
aker
Baker Environmental, me.
Prepared By:
BAKER ENVIRONMENTAL, INC.
Coraopplis, Pennsylvania
FOSTER \g) WHEELER
FOBTIR WHHLIK (NVIRMPONSI. INC.
SEPTEMBER 17,1992
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TABLE OF CONTENTS
Page
DECLARATION iv
1.0 SITE LOCATION AND DESCRIPTION 1
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES I
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION 5
4.0 SCOPE AND ROLE OF THE OPERABLE UNIT 6
5.0 SITE CHARACTERISTICS 6
6.0 SUMMARY OF SITE RISKS 7
7.0 DESCRIPTION OF ALTERNATIVES 9
Alternative 1: No Action 13
Alternative 2: No Action With Institutional Controls 13
Alternative 3: Biological Treatment at the STP 15
Alternative 4: Physical/Chemical Treatment (Air Stripping) 16
Alternative 5: Physical/Chemical Treatment (Carbon Adsorption) 17
Alternative 6: Thermal Treatment 17
Alternative 7: RCRA Facility 18
8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 18
Overall Protection of Human Health and the Environment 18
Compliance with ARARs 19
Long-Term Effectiveness and Permanence 19
Reduction of Toxicity, Mobility, or Volume of the Contaminants Through
Treatment ! 9
Short-Term Effectiveness 20
Implementability 20
Cost 20
EPA/State Acceptance 21
Community Acceptance 21
9.0 SELECTED REMEDY 21
Groundwater Collection System 22
Pretreatment System 22
Treatment System 23
Discharge to the Hadnot Point STP 23
Institutional Controls 24
Estimated Costs 24
10.0 STATUTORY DETERMINATIONS 24
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES 26
12.0 RESPONSIVENESS SUMMARY 27
12.1 Overview 27
12.2 Background on Community Involvements 27
12.3 Summary of Public Comments and Responses 28
ii
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LIST OF TABLES
Number Page
1 Summary of Contaminants of Concern Detected in the
Shallow Groundwater Aquifer, January 1991 8
2 . Frequency Summary of Groundwater Analytical Data
Collected from the Northern Groundwater Plume,
January 1991 10
3 Frequency Summary of Groundwater Analytical Data
Collected from the Southern Groundwater Plume,
January 1991 12
4 Glossary of Evaluation Criteria 14
5 Estimated Costs of Selected Remedy 25
LIST OF FIGURES
Number Page
1 Location Map, MCB Camp Lejeune 2
2 Location of Initial Phase Extraction Wells, On-Site Treatment
Systems, and Proposed Sanitary Sewer Lines 3
111
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DECLARATION
Site Name and Location
Hadnot Point Industrial Area (Site 78)
Marine Corps Base Camp Lejeune
Onslow County, North Carolina
Statement of Basis and Purpose
This decision document presents the selected interim remedial action (IRA) for the shallow
aquifer at the Hadnot Point Industrial Area (HPIA), Marine Corps Base (MCB) Camp Lejeune
(CLEJ), Onslow County, North Carolina which was chosen in accordance with the
Comprehensive Environmental Response, Compensation, and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and Reauthorization Act (SARA),
and, to the extent practicable, the National Contingency Plan (NCP). This decision is based
upon the administrative record for the Site.
The Navy/Marine Corps has obtained concurrence from the State of North Carolina and the
United States Environmental Protection Agency (EPA) Region IV on this interim action.
Assessment of the Site
Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present a
current or potential threat to public health, welfare, or the environment.
Description of Selected Remedy
This IRA is the first remedial action to be taken at the HPIA Operable Unit, of which the
HPIA (Site 78) is a part. This IRA, which addresses only the shallow aquifer at Site 78, is
being proposed to protect human health from exposure to benzene, trichloroethylene (TCE),
1,2-dichloroethene (1,2-DCE), and various metals in the shallow aquifer. This IRA addresses
the threat posed by the shallow aquifer but is not the final action planned for the site.
Subsequent actions are planned to fully address all of the impacted media at the site (i.e., soils,
IV
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and deeper aquifers) and to address all of the sites within the HPIA Operable Unit which are
not included in the scope of this IRA.
The principal threat at this time involves the potential migration of the contaminant plumes
in the shallow aquifer away from the site and into the deeper (drinking water) aquifer. The
primary goal of the IRA is to contain the contaminated groundwater in the shallow aquifer
thereby preventing the human consumption of contaminated groundwater. Upon completion
of the Final Remedial Investigation and Feasibility Study (RI/FS) for the entire HPIA
Operable Unit, this interim remedy will be incorporated into the design of the final remedy
specified in the Final ROD.
The major components of the selected remedy for this IRA include:
• Collecting the contaminated groundwater in the shallow aquifer at Site 78 through a
series of extraction wells installed within the two groundwater plumes.
• Pretreating the extracted groundwater for oil and grease via oil/water separators and
then for inorganics via a chemical removal system consisting of but not limited to
precipitation units, chemical reduction units, and sedimentation systems.
• Treating the volatile compounds (i.e., TCE and benzene) via on-site air stripper, and if
necessary, an activated carbon unit. The need for the activated carbon unit will be
determined from the results of a laboratory bench-scale treatability study.
• Sending the treated groundwater to an existing sewage treatment plant (STP) located
within MCB CLEJ for discharge to the New River.
• Institutional controls: restricting the use of nearby water supply wells (which are
screened in the deeper aquifer), and restricting the installation of any new water
supply wells in the area.
• Conducting a long-term groundwater monitoring program to monitor the effectiveness
of the IRA.
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Statutory Determinations
This interim remedial action is protective of human health and the environment, complies
with Federal and State applicable or relevant and appropriate requirements directly
associated with this action, and is cost-effective. In addition, this interim remedial action
utilizes permanent solutions and alternative treatment technologies (or resource recovery) to
the maximum extent practicable, given the limited scope of the action. Since this interim
remedial action does not constitute the final remedy for the HPIA Operable Unit (only for the
shallow aquifer at Site 78), the statutory preference for remedies that employ treatment that
reduces toxicity, mobility, or volume as a principal element will be addressed at the time of the
final response action. Subsequent actions are planned to fully address the principal human
health and environmental risks posed by the HPIA Operable Unit.
Signature (Commmding General, Date
MCB Camp Lejeune)
VI
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FINAL
INTERIM REMEDIAL ACTION
RECORD OF DECISION
FOR THE SHALLOW AQUIFER
AT THE HADNOT POINT INDUSTRIAL AREA OPERABLE UNIT
MARINE CORPS BASE, CAMP LEJEUNE, NORTH CAROLINA
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1.0 SITE LOCATION AND DESCRIPTION
The Hadnot Point Industrial Area (HPIA) Site is located within Marine Corps Base (MCB)
Camp Lejeune (CLEJ) in Onslow County, North Carolina. The HPIA Site is approximately 15
miles southeast of Jacksonville, North Carolina and 6 miles south of North Carolina State
Road 24 (Figure 1). The approximately 500 acre site is bordered by Holcomb Boulevard to the
northwest, Sneads Ferry Road to the northeast, Louis Street to the southeast, and Main
Service Road to the southwest (Figure 2).
The HPIA Site (Site 78) plus two other sites make up the overall HPIA Operable Unit. The
two additional sites include Site 21 (the Transformer Storage Yard), and Site 24 (the
Industrial Area Fly Ash Dump). Figure 2 identifies the location of these other two sites.
Sites 21 and 24 are not included in the scope of the selected Interim Remedial Action (IRA) but
will be part of the Final Remedial Investigation and Feasibility Study (RI/FS) for the entire
HPIA Operable Unit. In addition, please note that this document presents the Record of
Decision (ROD) for only the shallow aquifer at Site 78. Upon completion of the RI/FS for the
entire HPIA Operable Unit, a Final ROD will be prepared to present the selected remedial
actions for all contaminated media at the operable unit.
The HPIA, constructed in the late 1930's, was the first industrial complex at MCB CLEJ. It
was comprised of approximately 75 buildings and facilities including: maintenance shops, gas
stations, administrative offices, commissaries, snack bars, warehouses, storage yards, and a
dry cleaning facility. A steam plant and training facility occupy the southwest portion of the
HPIA.
In addition to Sites 21, 24 and 78, a fuel tank farm (Site 22) is located within the physical
boundaries of the HPIA Operable Unit. The fuel farm is an underground storage tank facility
which is not being administered under Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA) regulations. Therefore the site is not
included as part of the HPIA Operable Unit. At the present time, a fuel recovery/groundwater
treatment system is in operation at the tank farm.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
Several of the areas within the HPIA have been investigated for potential contamination due
to Marine Corps operations and activities resulting in the generation of potentially hazardous
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CAMP •-. LEJEUNE
MILITARY '; RESERVATION
CAMP \ LEJEUNE
RESERVATION
FIGURE 1
LOCATION MAP
MCB CAMP LEJEUNE, NORTH CAROLINA
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LEGEND
^ EXISTING MONITORING WELL LOCATION
APPROXIMATE SOURCE AREA OF GROUNDWATCR
CONTAMINATION IN THE SHALLOW AQUIFER
• PROPOSED EXTRACTION WELL LOCATION
MANHOLES
PROPOSED SEWER LINES TO BE USED
SOURCE: UlNTOIV. FEBRUABr 1992
FIGURE 2
LOCATION OF INITIAL PHASE EXTRACTION
. WELLS, ON-SITE TREATMENT SYSTEMS
AND PROPOSED SANITARY SEWER LINES
HADNOT POINT INDUSTRIAL AREA
MCB CAMP LEJF.UNI". NORTH CAROLINA
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wastes. The investigations indicate that contamination has resulted at HPIA due to former
improper waste disposal, underground storage tank leakage, solvent spills, and sludge
disposal.
Since 1983, various investigation and sampling activities have been conducted at the HPIA.
On October 4,1989, Camp Lejeune was placed on the National Priorities List (NPL). The
Department of the Navy (DoN), the EPA, and the North Carolina Department of
Environment, Health and Natural Resources (N.C. DEHNR) entered.into a Federal Facilities
Agreement on February 13,1991. The studies that have been conducted at the HPIA Site
(with respect to the shallow aquifer) are briefly summarized below.
In 1983, an Initial Assessment Study (IAS) was conducted at Camp Lejeune by Water and Air
Research, a consulting firm. The study identified a number of areas within Camp Lejeune,
including HPIA, as potential sources of contamination.
Between 1984 and 1988, Environmental Science and Engineering, Inc. (ESE) conducted a
Confirmation Study, which is analogous to an RI/FS performed for EPA on Federal Superfund
sites. The Confirmation Study was divided into two investigative steps: the Verification Step
and the Characterization Step.
The Verification Step took place from April 1984 through January 1985. Results of this
investigation indicated the presence of volatile organic compounds (VOCs) within the shallow
aquifer in the vicinity of HPIA fuel tank farm and in water supply well 602. The maximum
contaminant concentrations observed in the groundwater included 17,000 ug/L of benzene and
27,000 ug/L toluene collected from the tank farm area. Benzene was also detected in supply
well 602 at concentrations of 38 pg/L, which exceeds the Federal maximum contaminant level
(MCL)of5pg/L.
Due to the results of the Verification Step, supply well 602 was closed and other wells in the
area were sampled. Four additional supply wells (601,608, 634, and 637) were found to have
elevated levels of VOCs, including trichloroethylene (TCE) in wells 601 and 608 and
methylene chloride in well 634.
In 1986, the Characterization Step was conducted for HPIA to determine the extent of the
VOC contamination identified. During the Characterization Step, multiple tasks were
completed, including: a soil gas survey to target areas identified as being potentially
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contaminated, installation of 27 shallow (25 foot), 3 intermediate (75 foot), and 3 deep
(150 foot) monitoring wells, sampling of all HPIA monitoring wells and nearby water supply
wells, and aquifer testing to evaluate the hydraulic parameters of the deep aquifer.
Results of the characterization study revealed that five of the areas within HPIA showed
elevated levels of VOCs in soil gas: 1) Buildings 901, 902 and 903; 2) Building 1100;
3) Buildings 1101,1102,1202,1301, and 1302; 4) Buildings 1502,1601; and 5) Buildings 1709
and 1710. Results of the shallow monitoring well analyses revealed the presence of elevated
levels of a number of petroleum related compounds, including: benzene, xylene, ethylbenzene,
trans-l,2-dichloroethene (trans-l,2-DCE), TCE, oil and grease, and lead. Inorganics,
including mercury, were detected in several of the deep aquifer wells, but detected levels were
within Federal MCLs or ambient water quality criteria guidelines (AWQCs).
Baker Environmental, Inc. (Baker) prepared an IRA RI and an IRA FS for the HPIA during
1991-1992. These studies focused on the shallow groundwater aquifer beneath the HPIA and
were based solely on data generated during previous field investigations. The purpose of the
IRA RI was to consolidate currently available information on the shallow aquifer and to
develop the basis and supporting documentation for preparation of the IRA FS. The deep
aquifer is currently being investigated and will be addressed separately.
The IRA FS prepared by Baker considered various interim remedial actions which may be
taken to contain and/or remediate contamination in the shallow aquifer at Site 78 (the HPIA).
Based on the results of the above-mentioned studies and investigations, two contaminated
groundwater plumes have been identified in the shallow aquifer at the HPIA Site. The
contaminants of concern contained in these plumes include: benzene, 1,2-DCE, TCE,
antimony, arsenic, beryllium, chromium, lead, iron, manganese, mercury, nickel and oil &
grease. One of the plumes is located in the northeast portion of the site, the other in the
southwest portion of the site (Figure 2).
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The IRA RI/FS and the IRA Proposed Plan for shallow aquifer at the HPIA Site was released to
the public on May 14, 1992. These documents were made available to the public in the
administrative record at information repositories maintained at the Onslow County Public
Library and at the MCB CLEJ library. Also, all addressees on the HPIA mailing list were sent
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a copy of the Final Proposed Plan and Fact Sheet. The notice of availability of the Proposed
Plan and RI/FS documents was published in the "Jacksonville Daily News" on May 6-14,1992,
and in the "Globe" (MCB Camp Lejeune newspaper) on May 7,1992. A public comment period
was held from May 14 to June 14, 1992. In addition, a public meeting was held on
May 14, 1992. At this meeting, representatives from Navy/Marine Corps discussed the IRA
alternatives currently under consideration and addressed community concerns. Response to
the comments received during the comment period is included in the Responsiveness
Summary, which is part of this IRA ROD.
This decision document presents the selected IRA for the shallow aquifer at the HPIA Site,
MCB Camp Lejeune, Onslow County, North Carolina, chosen in accordance with CERCLA, as
amended by the Superfund Amendments and Reauthorization Act (SARA), and, to the extent
practicable, the National Contingency Plan (NCP). The decision for this Site is based on the
administrative record.
4.0 SCOPE AND ROLE OF THE OPERABLE UNIT
The proposed IRA for the HPIA Site is a component of the overall site strategy in that it
restricts the migration of the contaminant plumes identified in the shallow aquifer.
Implementation of this IRA will reduce the potential for the migration of the contaminated
groundwater both horizontally and vertically, which in turn will reduce the risk to human
exposure through continued contamination of the aquifer. In addition, this IRA will reduce
any potential threat to environmental receptors. This IRA is consistent with future plans for
complete remediation of the HPIA Operable Unit and will not preclude implementation of a
comprehensive final remedy.
Subsequent actions are planned to fully address all of the contaminated media within the
HPIA Operable Unit. The overall site remediation strategy will include the remediation of
the other two sites within the HPIA Operable Unit (i.e., the Transformer Storage Area,
Site 21, and the Fly Ash Dump Area, Site 24).
5.0 SITE CHARACTERISTICS
The hydrologic system at CLEJ consists of an unconfined aquifer (water table) and underlying
semicohfined aquifers. The unconfined aquifer extends from the water table to the first
significant confining layer, approximately 25 feet below land surface. The water table within
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HPIA ranged at an elevation between 8.48 and 25.56 mean sea level during January 1991.
Groundwater flow in the shallow aquifer is predominantly to the southwest in the southern
portion of portion of the site and to the west-southwest in the northern and central portions of
the site.
As previously stated, various investigation and sampling activities have been conducted at the
HPIA since 1983. During these studies, shallow, intermediate, and deep groundwater
monitoring wells have been installed and sampled. The analytical results detected two
plumes of groundwater contamination containing the following contaminants of concern:
benzene, TCE, 1,2-DCE, and various metals including arsenic, antimony, beryllium,
chromium, lead, iron, manganese, mercury, and nickel (Figure 2). Many of these compounds
were detected at levels greater than the Federal Drinking Water Regulations and/or the North
Carolina Water Quality Criteria for Groundwater. Table 1 presents a summary of the
detected contaminants of concern for the shallow aquifer from a January 1991 sampling event.
The Federal and North Carolina standards with respect to each of these contaminants are also
identified on Table 1.
Since the shallow aquifer and the deep aquifer (a drinking water source) at the HPIA Site are
interconnected, there is potential human and environmental exposure to the contaminants
detected in the shallow aquifer. In addition, there is also potential for human exposure to the
shallow aquifer contaminants due to migration towards the New River. The primary pathway
of exposure would be through ingestion of contaminated water by humans, aquatic life, and/or
wildlife.
6.0 SUMMARY OF SITE RISKS
The results of the IRA RI identified two contaminated plumes within the shallow aquifer at
Site 78. Multiple contaminants were detected above MCLs and therefore formed the basis for
proceeding with an IRA. These plumes can potentially impact drinking water supply wells in
the area. In 1986, VOCs were identified in five on-site supply wells screened in the deeper
aquifer (currently being addressed as part of the additional studies at the site), and
subsequently, the wells were closed. It is not known whether or not the contaminants detected
in the shallow aquifer have contributed to the contamination of these deeper wells.
As part of the IRA RI, a qualitative baseline risk assessment was conducted with respect to the
shallow aquifer at the HPIA Site. The risk assessment identified potential human and
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I LEI
SUMMARY OF CONTAMINANTS OF CONCERN DETECTED IN THE SHALLOW CROUNDWATER AQUIFER, JANUARY 1991
Potential Contaminant*
of Concern
VOCa(u»/l)!
Bcnaeno
1.2-DKhloroothene(1.2.-DCE)
Trichloroethone (TCE)
Inornnlca (ue/lk
Coronuum
Iron
Load
Manganeae
Antimony
Araenic
Beryllium
Mercury
Ntckal
Potential Contaminant*
yOCKudn-.
Benzene
1 .2-Diehloroothen* (1 4.-DCE)
TrichloroaUiana (TCE)
Inorffan|e| (uf/lh
Chromium
Iron
Lead
Manfaneae
Antimony
Araanic
B«ry Ilium
Mercury
Nickel
HPGW1
6<
73
91
87
64100
16.6
168
13 J<
88
6
O.K
SUB
HPCW17-1
8<
8<
6<
S7
10600
JS.7
31.3
22 <
13<
2.1<
O.K
11.9B
HPCW2
6<
6<
6<
64J
34800
29.4
77
16.6B
24.1
1.7B
0.1 <
16.9B
HPGW18
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
HPGW3
o<
5<
8<
16.7
10400
11.4
83.9
46.8B
15.6
1JB
O.K
I2.1B
HPGW19
8<
0.8J
2J
13.8
36200
31.7
79
13.3
SB
JJB
N/A
7JB
HPCW4-1
6<
8<
0.9J
187
100000
66.6
425
21.9B
16.5
6.7
O.K
67
HPGW20
6<
6<
6<
424
162000
20
217
21.9B
49.4
9.5
0.6
168
HPGW6
6<
6<
6<
3.6B
3100
13.6
162
13.3 <
1JS<
0.86B
O.K
6.2 <
HPGW21
6<
6<
3J
46
66600
49.4
136
13.3 <
12.1
3.7B
O.K
30.8B
HPGW6
6<
6<
6<
1690
266000
60.7
487
13 J<
31.6
20
1.4
161
HPCW22
5<
6<
6<
79.8
24400
39.4
94.1
24.6B
7.2B
0.6B
O.K
23.2B
HPOW7
'6<
6<
6<
313
65700
112
136
22<
18 J
4.8B
0.26
50.7
HPCW23
24
8900
3700
76J
23300
46
68.8
24.6B
6.6B
IB
O.K
33.2B
HPCW8
6<
6<
11
91.8
40900
64.1
46.6
22
28.4
2.1
0.13
25.2
HPGW24
3J
42000D
180
26.3
19200
21.4
M.8
22<
4.2B
2.1<
O.K
14<
HPCW9-1
6<
1200
14000
66.4
19800
128
46
17.6B
3B
0.79B
O.K
1S.1B
HPCW26
6<
6<
6<
206
46600
71.6
118
13J<
13.2
1.8B
O.K
39.2B
HPGW10
6<
6<
6<
310
119000
186
266
22<
39.9
6.6
0.82
92.2
HPGW26
6<
6<
6<
13
19000
9
10.6B
13.3 <
1.6<
0.6 <
O.K
5.2 <
HPGW11
6<
6<
6<
. 140
31800
46.2
103
22<
9.1B
2.K
0.1B
23.6B
HPGW29
6<
6<
6<
179
76200
29.1
236
13 J<
26.6
8.7
O.K
93.6
HPCW12
6<
5<
6<
25.6
6600
16.7
18 J
22 <
IA<
2.K
O.K
IK
22GW1
7900
5<
6J
467
101000
307
284
20.9B
60J
6.8
0.35
186
HPGW13
6<
6<
6<
48.9
33500
9
30J
13.3<
47
0.59B
O.K
J1JB
22GW2
6<
6<
6<
26J
16200
16J
763
13.3
11
0.6
0.1
17
HPGW14
6<
6<
6<
127
87200
66^
80
13.3 <
46.6
2.7B
OJ6
41.6
HPGW16
6<
7
4J
21.4
4800
16.6
18 J
22 <
l.S<
2.1<
O.K
IK
North Carolina
Watar Quality
Criteria (ug/1)
1
-
2.8
60
300
60
60
-
60
0.6
1.1
150
HPGW16
6<
6<
6<
209
47200
100
98.3
22<
17.3
6J
0.13B
41
Federal Drinking
Water MCLa(uzyl)
6
-
6
100
-
16
-
6
60
4
2
100
00
NoteK
N/A
<
J
a
o
Not analyzed
Compound waa anabyied. but not detected at the liated detection limit
Value la animated
Reported value U < contract required detection limit, but > Inltrument detection limit (IDL)
Compound Identified In an analyeia at a eecondary dilution factor
Nnl««t.Mi.h~< '
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environmental receptors to any contamination attributable to the site, identified potential
pathways of exposure, quantified the exposure levels, and evaluated the potential human
and/or environmental risk. The results of this qualitative risk assessment indicated that
there are potential human and environmental receptors to the contamination of the shallow
aquifer at Site 78.
The groundwater analyses detected several organic and inorganic compounds in the shallow
aquifer at Site 78. Table 2 presents a frequency summary of the compounds detected in the
northern most groundwater plume with respect to Federal Drinking Water MCLs and North
Carolina Water Quality Standards for Groundwater. Ten organic compounds and nine
inorganic compounds exceeded at least one of the Federal or North Carolina standards. The
risk assessment evaluated that TCE, antimony, arsenic, beryllium, chromium, iron, lead,
manganese, and nickel are the contaminants of concern for this plume.
Table 3 presents a summary of the compounds detected in the southern most groundwater
plume with respect to the Federal and North Carolina standards. Four organic compounds
and nine inorganic compounds exceeded at least one of the Federal or North Carolina
standards. The risk assessment determined that TCE, 1,2-DCE, antimony, arsenic, beryllium,
chromium, iron, lead, manganese, mercury, and nickel are the contaminants of concern for
this plume.
A quantitative risk assessment will be completed when the Final RI/FS for the entire HPIA
Operable Unit is conducted.
7.0 DESCRIPTION OF ALTERNATIVES
Extraction and treatment of the contaminated groundwater is an element of each of the
treatment alternatives evaluated for the shallow aquifer at the HPIA Site, with the exception
of two "no action" alternatives. The seven interim remedial action alternatives evaluated in
the IRA FS for the containment/ remediation of the contaminant plumes in the shallow
aquifer at the HPIA Site are:
Alternative 1: No Action
Alternative 2: No Action With Institutional Controls
Alternative 3: Biological Treatment at the Sewage Treatment Plant (STP)
Alternative 4: Physical/Chemical Treatment (Air Stripping)
-------
TABLE 2
FREQUENCY SUMMARY OF GROUNDWATER ANALYTICAL DATA COLLECTED
FROM THE NORTHERN GROUNDWATER PLUME, JANUARY 1991
Compound
ORGANICS:
Acetone
Benzene
Carbon Bisulfide
Dichloroethene, 1,2-
Dichloroethene, 1,1-
Dichloroethene (total), 1,2-
Ethylbenzene
Methylene chloride
Tetrachloroethylene
Toluene
Trichloroethane, 1,1,2-
Trichloroethylene
Vinyl chloride
Xylene (total)
SEMI-VOLATILES:
Acenaphthene
bis(2-
EthylhexyDphthalate
Dibenzofuran
Fluorene
2-Methylnaphthalene
2-Methylphenol
Naphthalene
INORGANICS:
Aluminum
Antimony
Arsenic
Barium
Beryllium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Frequency
of Detects
2/12
3/12
4/12
2/12
1/12
3/12
4/12
4/12
1/12
3/12
1/12
5/12
1/12
4/12
2/12
1/12
1/12
1/12
2/12
1/12
2/12
12/12
4/12
10/12
12/12
8/12
12/12
12/12
7/12
12/12
12/12
12/12
Standards
North Carolina
Water Quality
Criteria for
Groundwater
(ug/L)
NSd)
1
NS
0.38
7
NS
29
5
0.7
1000
NS
2.8
0.015
400
NS
NS
NS
NS
NS
NS
NS
NS
NS
50
1000
NS
NS
50
NS
1000
300
50
Drinking
Water
MCLs
(ug/L)
NS
5
NS
5
7
NS
700
5(2)
5
1000
5(3)
5
2
10000
NS
NS
NS
NS
NS
NS
NS
NS
6(3)
50
2000
4(3)
NS
100
NS
1300«)
NS
15«>
No. of Detects Greater
than Standards
North
Carolina
-
3/3
—
2/2
1/1
-
1/4
1/4
1/1
1/3
-
4/5
1/1
1/4
•-
-
~
—
-
-
-
—
-
1/10
0/12
—
—
6/12
-
0/12
12/12
3/12
Drinking
Water
MCLs
--
2/3
—
1/2
1/1
-
1/4
1/4
0/1
1/3
0/1
3/5
1/1
0/4
-
-
—
~
—
-
-
—
4/12
1/10
0/12
6/8
—
4/12
—
0/12
—
11/12
10
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TABLE 2 (Continued)
FREQUENCY SUMMARY OF GROUNDWATER ANALYTICAL DATA COLLECTED
FROM THE NORTHERN GROUNDWATER PLUME, JANUARY 1991
Compound
INORGANICS: (Cont.)
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
PESTICIDES:
Dieldrin
Frequency
of Detects
12/12
12/12
3/12
10/12
12/12
2/12
6/12
12/1,2
1/12
12/12
12/12
1/12
Standards
North Carolina
Water Quality
Criteria for
Groundwater
(ug/L)
NS
50
1.1
150
NS
10
50
NS
NS
NS
5000
-
Drinking
Water
MCLs
(pg/L)
NS
NS
2
1000)
NS
50
NS
NS
2(3)
NS
NS
~
No. of Detects Greater
than Standards
North
Carolina
-
10/12
0/3
2/10
—
0/2
0/6
—
--
—
0/12
--
Drinking
Water
MCLs
--
--
0/3
2/10
—
0/2
-
—
1/1
--
—
--
(!) NS: Denotes no standard established
(2) Proposed maximum contaminant level (MCL)
(3) Effective date: January 17,1994
(4) MCL is Action level for Public Water Supply System
11
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TABLE 3
FREQUENCY SUMMARY OF GROUNDWATER ANALYTICAL DATA COLLECTED
FROM THE SOUTHERN GROUNDWATER PLUME, JANUARY 1991
Compound
ORGANICS:
Acetone
Carbon Disulflde
Chloroform
Dichloroethene (total), 1,2-
2thylbenzene
VIethylene Chloride
Toluene
["richloroethene
Xylene (total)
SEMI-VOLATILES:
bix(2-Ethylhexyl)phthalate
Methylnaphthalene,2-
^aphthalene
INORGANICS:
Aluminum
Antimony
Arsenic
Barium
Beryllium
Calcium
Chromium
Cobalt
Copper
Ton
Lead
Magnesium
Manganese
VIercury
Nickel
Potassium
Selenium
Silver
Sodium
Vanadium
Zinc
Frequency
of Detects
2/16
2/16
1/16
3/16
1/16
4/16
1/16
5/16
1/16
2/16
1/16
1/16
16/16
4/16
13/16
6/16
12/16
6/16
16/16
10/16
16/16
16/16
16/16
16/16
16/16
6/16
12/16
16/16
7/16
- 5/16
16/16
15/16
16/16
Standards
North Carolina
Water Quality
Criteria for
Groundwater
(ug/L)
NS(D
NS
0.19
NS
29
5
1000
2.8
400
NS
NS
NS
NS
NS
50
1000
NS
NS
50
NS
1000(4)
300
50
NS *
50
1
150
NS
10
50
NS
NS
5000
Drinking
Water
MCLs
(ug/L)
NS '
NS
NS
NS
700
5(2)
1000
5
10000
NS
NS
NS
NS
6(3)
50
2000
4(3)
NS '
100
NS
1300W)
NS
15«)
NS
NS
2
100(3)
NS
50
NS .
NS
NS
NS
No. of Detects Greater
than Standards
North
Carolina
—
—
1/1
-
1/1
0/4
0/1
3/5
1/1
-
-
-
-
—
0/13
1/16
-
—
11/16
-
0/16
16/16
7/16
-
11/16
1/6
1/12
—
0/7
0/5
~
—
0/16
Drinking
Water
MCLs
~
-
-
--
1/1
0/4
0/1
2/5
0/1
-
-
-
—
4/4
0/13
1/16
9/12
—
7/16
-
0/16
—
13/16
--
~
0/6
1/12
—
0/7
—
~
-
--
-------
Alternative 5: Physical/Chemical Treatment (Carbon Adsorption)
Alternative 6: On-site Thermal Treatment
Alternative?: Off-siteRCRAFacility
These alternatives are intended to prevent the spread of contaminated groundwater by
halting the migration of the contaminated shallow groundwater plume early in the Superfund
process. The final alternative for the shallow aquifer may require alteration and refinement,
based on monitoring results and the evaluation of data collected during implementation of
interim remedial action,
A brief overview of each of the interim remedial action alternatives is included below. All
costs and implementation times are estimated.
Alternative 1: No Action
There are no costs associated with the No Action Alternative.
The No Action Alternative is required by the NCP to be considered through the nine point
evaluation criteria summarized on Table 4. It provides a baseline for comparison of other
alternatives. Under the No Action Alternative, no remedial measures would be undertaken at
the HPIA Site at the present time. Potential health risks would remain associated with the
current potential exposure by ingestion of contaminated groundwater.
Chemical-specific ARARs (i.e., Federal Drinking Water Standards and North Carolina Water
Quality Criteria for Groundwater) would not be met with this alternative.
Alternative 2: No Action With Institutional Controls
Capital cost: $0 (Minimal)
Annual Operation and
Maintenance (O&M) Costs: $60,000 for Years 1 through 30
Present Worth (PW): $970,000
Months to Implement: 15
Under the No Action With Institutional Controls Alternative, the groundwater in the shallow
aquifer will be left as is and no remedial actions will be implemented. This alternative
includes quarterly sampling of 20 existing monitoring wells at the HPIA Site. In addition, use
13
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TABLE 4
GLOSSARY OF EVALUATION CRITERIA
• Overall Protection of Human Health and Environment • addresses whether
or not an alternative provides adequate protection and describes how risks posed
through each pathway are eliminated, reduced, or controlled through treatment
engineering controls or institutional controls.
• Compliance with ARARs - addresses whether or not an alternative will meet all
of the applicable or relevant and appropriate requirements (ARARs) or other
Federal and State environmental statutes and/or provide grounds for invoking a
waiver.
• Long-term Effectiveness and Permanence - refers to the magnitude of
residual risk and the ability of an alternative to maintain reliable protection of
human health and the environment over time once cleanup goals have been met.
• Reduction of Toxicity, Mobility, or Volume through Treatment - is the
anticipated performance of the treatment options that may be employed in an
alternative.
• Short-term Effectiveness - refers to the speed with which the alternative
achieves protection, as well as the remedy's potential to create adverse impacts on
human health and the environment that may result during the construction and
implementation period.
• Implementability - is the technical and administrative feasibility of an
alternative, including the availability of materials and services needed to
implement the chosen solution.
• Cost - includes capital and operation and maintenance costs. For comparative
purposes, presents present worth values.
• State Acceptance - indicates whether, based on its review of the RI and FS
reports and the Interim Action Proposed Plan, the State concurs with, opposes, or
has no comment on the preferred alternative.
• Community Acceptance - will be assessed in the Record of Decision (ROD)
following a review of the public comments received on the RI and FS reports and
the Interim Action Proposed Plan.
14
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of the aquifer and installation of new water wells will be restricted. Like the No Action
Alternative, potential health risks would remain associated with the current potential
exposure by ingestion of contaminated groundwater.
Chemical-specific ARARs (i.e., Federal Drinking Water Standards and North Carolina Water
Quality Criteria for Groundwater) would not be met with this alternative.
Alternative 3: Biological Treatment at the STP
Capital cost: $1.3 million
Annual O&M Costs: $334,000 for Years 1 through 30
PW: $6.9 million
Months to Implement: 15
Alternative 3 includes groundwater extraction, pretreatment for oil and grease and for
inorganic chemicals, treatment of VOCs at the existing Hadnot Point STP, and institutional
controls.
Groundwater extraction would be accomplished through a phased approach. Initially, four
extraction wells will be installed in each of the two contaminated plume areas (Figure 2).
Based upon the results of groundwater monitoring following the first year of operation,
additional extraction wells may be installed. Groundwater modeling may be employed at this
time (following the first year of operation) to help select the appropriate number and location
of extraction results. (For costing purposes only in the IRA FS, it was assumed that eight
additional extraction wells would be installed during each of the first three years of operation
for a total of 32 wells.)
The pretreatment system will consist of an oil/water gravity separator, an inorganic chemical
removal system utilizing at least precipitation, chemical reduction, and sedimentation
technologies. The biological system that will be utilized at the existing Hadnot Point STP
consists of an aerated equalization lagoon, primary clarifiers, two trickling filters, secondary
clarifiers, anaerobic digestors, and chlorine contact chambers. The effluent from the Hadnot
Point STP discharges to the New River.
The same institutional controls (i.e., groundwater monitoring, aquifer-use restrictions, and
well installation restrictions) identified in Alternative 2 will be included in this alternative.
15
-------
Chemical-specific ARARs (i.e., Federal Drinking Water Standards and North Carolina Water
Quality Criteria for Groundwater) will be met with this alternative. This alternative may
require an NPDES permit modification for the Hadnot Point STP. The modification may
result in additional monitoring parameters and/or monitoring frequencies. This alternative
should be able to meet these additional requirements.
OSHA and the State of North Carolina have established VOC air emission limits for the
protection of human health and the environment. At the Hadnot Point STP, the major
emissions source is the aerated lagoon. Preliminary results from air modeling efforts have
concluded that the implementation of this alternative should be able to meet these established
air emission limits.
The TCE-contaminated groundwater in the HPIA shallow aquifer is excluded from being
considered a listed hazardous waste under the one part per million solvent exclusion provided
under RCRA (40 CFR 261.3). Therefore. RCRA will not be applicable to the permitting or
design of the HPIA sewage treatment system when the contaminated groundwater is
introduced. However, since the extracted groundwater from HPIA is expected to contain
VOCs, the sludge generated from the Hadnot Point STP would be required to be analyzed for
TCLP constituents. If the sludge would exceed TCLP levels, the sludge will be required to be
handled as a hazardous waste in accordance with RCRA.
Alternative 4: Physical/Chemical Treatment (Air Stripping)
Capital cost: $1.0 million
Annual O&M Costs: $352,000 for Years 1 through 30
PW: $7.6 million
Months to Implement: 15
Alternative 4 is similar to Alternative 3 with the exception of the method of groundwater
treatment. In general, the Air Stripping Alternative includes groundwater extraction,
pretreatment for oil and grease and for inorganic chemicals, treatment for VOCs via an on-site
air stripper, discharge to the Hadnot Point STP, and institutional controls. The same
extraction and pretreatment systems identified in Alternative 3 and the same institutional
controls identified in Alternative 2 will be included in this alternative.
Chemical-specific ARARs (i.e., Federal Drinking Water Standards and North Carolina Water
Quality Criteria for Groundwater) will be met with this alternative. OSHA and the State of
16
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North Carolina VOC air emission limits may be applicable for the air stripper. These ARARs
should be met with this alternative. No RCRA ARARs will apply since this alternative
includes on-site treatment.
Alternative 5: Physical/Chemical Treatment (Carbon Adsorption)
Capital cost: $940,000
Annual O&M Costs: $400,000 for Years 1 through 30
PW: $7.6 million
Months to Implement: 15
Alternative 5 is similar to Alternatives 3 and 4 with the exception of the method of
groundwater treatment. In general, the Carbon Adsorption Alternative includes groundwater
extraction, pretreatment for oil and grease and for inorganic chemicals, treatment for VOCs
via on-site carbon adsorption units, discharge to the Hadnot Point STP, and institutional
controls. The same extraction and pretreatment systems identified in Alternative 3 and the
same institutional controls identified in Alternative 2 will be included in this alternative.
Chemical-specific ARARs (i.e., Federal Drinking Water Standards and North Carolina Water
Quality Criteria for Groundwater) will be met with this alternative. No air emission, NPDES,
or RCRA ARARs will apply to this alternative.
Alternative 6: Thermal Treatment
Capital cost: $1.5 million
Annual O&M Costs: $627,000 for Years 1 through 30
PW: $11.8 million
Months to Implement: 15
Alternative 6 is similar to Alternatives 3, 4 and 5 with the exception of the method of
groundwater treatment. In general, the Thermal Treatment Alternative includes
groundwater extraction, pretreatment for oil and grease and for inorganic chemicals,
treatment for VOCs via an on-site liquid injection incinerator, and institutional controls. The
same extraction and pretreatment systems identified in Alternative 3 and the same
institutional controls identified in Alternative 2 will be included in this alternative.
Chemical-specific ARARs (i.e., Federal Drinking Water Standards and North Carolina Water
Quality Criteria for Groundwater) will be met with this alternative. OSHA and the State of
17
-------
North Carolina VOC air emission limits may be applicable for the incinerator. These ARARs
should be met with this alternative. No RCRA or NPDES ARARs will apply to this
alternative.
Alternative 7: RCRA Facility
Capital cost: $900,000
Annual O&M Costs: $4.2 million for Years 1 through 30
PW: $68.9 million
Months to Implement: 15
Alternative 7 is somewhat similar to Alternatives 3, 4, 5 and 6 with the exception of the
method of groundwater treatment. In general, the RCRA Facility Alternative includes
groundwater extraction, off-site treatment at an approved RCRA facility, and institutional
controls. The same extraction system identified in Alternative 3 will be included in this
alternative. No pretreatment systems are included in this alternative. The same institutional
controls identified in Alternative 2 will be included in this alternative.
Chemical-specific ARARs (i.e., Federal Drinking Water Standards and North Carolina Water
Quality Criteria for Groundwater) will be met with this alternative. No air emission ARARs
or NPDES ARARs apply to this alternative. RCRA ARARs will apply and should be met
under this alternative.
8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
A detailed analysis was performed on the seven IRA alternatives using the nine evaluation
criteria in order to select a site remedy. A brief summary of each alternative's strengths and
weaknesses with respect to the evaluation criteria follows. A glossary of the evaluation
criteria has previously been noted on Table 4.
Overall Protection of Human Health and the Environment .
The five "pump and treat" alternatives would provide protection of human health and the
environment by reducing or controlling risk through treatment, engineering controls, or
institutional controls. Each of these "pump and treat" alternatives would treat the
contaminants in the extracted groundwater, thereby reducing the risks associated with
18
-------
contact with the groundwater and minimizing the migration of contamination from the
groundwater.
Since neither the No Action Alternative nor the No Action With Institutional Controls
Alternative are protective.of human health and the environment, they are not considered
further in this analysis as an option for the HPIA Site.
Compliance with ARARs
An interim remedial action alternative need only address those ARARs applicable or relevant
and appropriate to the limited-scope interim action. All of the treatment alternatives will
meet the NPDES requirements for discharge to a surface water body. ARARs for the aquifer
are Federal and North Carolina MCLs for drinking water and groundwater, respectively. In
addition, applicable air emission ARARs (OSHA and North Carolina limits) and RCRA
ARARs apply to several of the alternatives. The ultimate goal of all of the "pump and treat"
alternatives is to meet all of the above-mentioned ARARs. The final remedial alternative (to
be proposed after completion of additional studies) will provide additional information on the
compliance with ARARs.
Long-Term Effectiveness and Permanence
This criteria is irrelevant to the interim action presented in this Proposed Plan. Long-term
effectiveness and permanence will be evaluated as part of the final remedial action for the
shallow aquifer.
Reduction of Toricity. Mobility, or Volume of the Contaminants Through Treatment
All of the "pump and treat" alternatives would extract and treat the contaminated
groundwater to reduce the toxicity, mobility, and volume of the contaminants in the water.
The toxicity of the contaminants will be reduced through treatment. The mobility of the
contaminants will be reduced by containment of the plumes via the extraction wells. Total
volume of the contaminants will be reduced by the combination of pumping and treatment
over the duration of the interim remedial action.
19
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Short-Term Effectiveness
It is not expected that the implementation cf any of the alternatives would cause adverse
effects to human health and the environment. Workers could be exposed to contaminated soil
or water during construction and installation of the extraction well systems. Implementation
of appropriate worker health and safety precautions will mitigate any threat. No threats to
the community are anticipated, due to the location and industrial nature of the activities at
HPIA, All of the "pump and treat" alternatives will be effective in achieving the goal of
reducing contaminant migration upon implementation. Alternatives 3, 4 and 5 would take
approximately 15 months to implement. Alternatives 6 and 7 are also anticipated to require
15 months to implement since they are dependent on the availability of equipment and/or the
capacity at an off-site facility.
Implementability
All of the alternatives have similar administrative difficulties (i.e., obtaining permits) that
could delay implementation. Acquiring the necessary permits for off-site actions is feasible
and should not adversely affect the implementability of any of the alternatives. Note that only
the substantive technical requirements of permits must be met for a remedial action
implemented on site. All of the alternatives are technically feasible and, therefore,
implementable. The majority of the required equipment for each of the alternatives is readily
available. Alternative 3 has an advantage with implementability since the biological system
is in-place and operating at the existing sewage treatment plant within CLEJ. However, due
to the unknown condition of the sewer line, this alternative may result in extensive
construction time for relining or replacement of the sewer line.
Cost
Alternative 3 has the lowest present worth cost as compared to Alternatives 4,5,6 and 7. The
present worth cost for Alternative 3 is approximately $6.9 million; Alternative 4 is
approximately $7.6 million; Alternative 5 is $7.6 million; Alternative 6 is approximately
$11.8 million; and Alternative 7 is approximately $68.9 million.
20
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EPA/State Acceptance
The Environmental Protection Agency and the State of North Carolina DEHNR have
concurred with the selection of this alternative.
Community Acceptance
No private citizens attended the public meeting held on May 14, 1992 or provided any
comments during the 30-day comment period. The issues regarding the contaminated shallow
aquifer at the HPIA may not be of a concern to the community. This lack of concern may be
due to the location of the site within an industrial area and away from residential areas.
9.0 SELECTED REMEDY
The preferred interim remedial action alternative for reducing the potential for further
migration of the contamination in the shallow aquifer at HPIA is Alternative 4:
Physical/Chemical Treatment (Air Stripping). Based on available information, this
alternative appears to provide the best balance with respect to the nine CERCLA evaluation
criteria used to evaluate alternatives. The action will limit the extent of migration of the
contamination in the shallow groundwater aquifer and reduce the concentration of
contaminants in the groundwater. This interim remedial action will be consistent with any
other remedial actions that are selected for the site. A description of Alternative 4 is included
below.
In general, Alternative 4 includes groundwater extraction, pretreatment, groundwater
treatment and discharge, and institutional controls. The on-site pretreatment system will
consist of an oil/water gravity separator, and a combination of one of several inorganic
removal technologies including but not limited to precipitation, chemical reduction, and
sedimentation. Treatment of the VOCs in the groundwater will be conducted via an on-site air
stripper. Based on the results of bench-scale treatability study, a carbon adsorbtion unit may
be added to the treatment system. The treatability study will be conducted during the design
of this alternative. The existing Hadnot Point STP will be used for the off-site discharge of the
treated groundwater. A long-term groundwater monitoring program will be implemented,
and restrictions will be placed on the use of the shallow aquifer and on the installation of new
wells. Details of each of the components making up this alternative are discussed below.
21
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Groundwater Collection System
Groundwater in the shallow aquifer at HPIA will be withdrawn through a series of extraction
wells. The details of the extraction system (i.e., number, location, and pumping rates of the
extraction wells) will be determined through a phased approach. Preliminary aquifer
characteristics were previously estimated, based on the results of an eight-hour pump test on
two wells screened in the shallow aquifer. These estimates will be confirmed or reevaluated as
extraction wells are installed and the groundwater is monitored.
Initially, four 4-inch wells will be installed at each of the two groundwater plumes and
pumped at a rate of two to five gpm. Additional wells will be added to the system as dictated
by monitoring results. For costing purposes only, it was assumed that eight additional
extraction wells (four within each plume area) will be installed at three different times during
the first few years of operation. Therefore, the complete extraction system will include 32
wells. Please note that the total number of extraction wells required to successfully
implement the IRA will be determined as the wells are installed, and testing and monitoring
of the groundwater will provide a means of evaluating the need for additional wells. The
location of these additional wells has not been determined at this time.
Pretreatment System
Once extracted, the contaminated groundwater will be pumped to an on-site pretreatment
system. A pretreatment system will be located within the area of each plume. The first step in
the pretreatment system will consist of a gravity oil/water separation process for the removal
of floating oils and/or oily wastes that are heavier than water. The oil/water gravity
separation system will include a holding tank for retention of the extracted groundwater, and
a surface skimming and bottom collection system. Baffles will be included in the design of the
gravity separator in order to provide additional surface area. Collected free product will be
either sold to a waste oil recycler or incinerated in a RCRA-permitted facility.
The aqueous effluent from the gravity separation system will be transferred to an inorganic
chemical removal system for the removal of the inorganic contaminants of concern
(e.g., chromium, lead, manganese, iron, etc.). The inorganic system will include but not be
limited to the following technologies: precipitation, chemical reduction, and sedimentation.
Residuals generated from the pretreatment systems.will be disposed of properly.
22
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Treatment System
The aqueous effluent from the inorganic chemical removal system will be pumped to an on-site
treatment system consisting of two air stripping units (one location within each source plume
area). The on-site air stripping units will be designed for the treatment of volatile organic
compounds (VOCs). Residuals generated from this process will include air emissions
contaminated with organics. If required, vapor recovery equipment will be added to prevent
the release of stripped organics into the atmosphere. The vapor recovery equipment will
generate additional waste contaminated with organics which will require proper off-site
disposal or regeneration. If necessary, an activated carbon system will be included in the
groundwater treatment system. The results of a laboratory bench-scale treatability study will
determine whether the activated carbon system is necessary.
Discharge to the Hadnot Point STP
The treated effluent from the air stripping systems will be pumped to the closest sanitary
sewer manholes for discharge to the existing biological treatment system at the Hadnot Point
STP for final discharge to the New River.
The existing Hadnot Point STP, located south-southeast of the HPIA area, has an operating
capacity of 8 million gallons per day. The STP is a biological treatment system consisting of
an aerated equalization lagoon, primary clarifiers, trickling filters, secondary clarifiers,
chlorine contact chamber, anaerobic digesters, and sludge drying beds.
The STP receives sanitary wastewater from both residential and industrial areas. The
influent into the plant enters the aerated equalization lagoon (two million gallon capacity).
The lagoon is aerated with five floating aerators. The aerated wastewater is pumped from the
lagoon to the primary influent chamber and then to one of eight 80,000 gallon primary
clarifiers. The resulting aqueous effluent form the primary clarifiers is pumped to the
secondary treatment area consisting of two 1.3-million gallon trickling filters followed by two
300,000-gallon secondary clarifiers, followed by a 29,000-gallon chlorine contact chamber.
Sludge and oil and grease collected in the primary and secondary clarifiers is pumped to one of
six 140,000-gallon anaerobic digesters. Digested sludge is pumped to one of twenty-five
drying beds. The final effluent from the chlorine contact chamber is discharged to the New
River.
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Under Alternative 4, the treated groundwater will be mixed in-line with the sewage the plant
is currently receiving. Since the treated groundwater will be mixed with the current plant
influent, STP effluent discharge and sludge disposal will continue to be handled by the STP in
the same manner as currently used. The resulting effluent will be discharged to the New
River.
Institutional Controls
In order to track the effectiveness of the "pump and treat" method, a long-term groundwater
monitoring program will be implemented. The monitoring program will include periodic
sampling of approximately 20 monitoring wells. Samples will be collected on a quarterly basis
for 30 years and analyzed for the constituents of concern. Restrictions will be placed on the use
of the shallow aquifer, the water supply wells will remain closed, and no new wells will be
permitted to be installed in the area.
Estimated Costs
The estimated capital costs associated with the Physical/Chemical Treatment (Air Stripping)
Alternative is approximately $1,012,000. Operation and maintenance (O&M) costs of
approximately $352,000 annually are projected for the operation of the treatment system and
the sampling of 20 existing monitoring wells. Assuming a monitoring period of 30 years and
an annual percentage rate of 5%, this equates to a net present worth of $7.6 million. Table 5
presents a summary of this cost estimate for the major components.
10.0 STATUTORY DETERMINATIONS
This IRA alternative is part of an overall remedy for the entire HPIA Operable Unit. This IRA
alternative will provide adequate protection of human health and the environment through
treatment, engineering controls, and institutional controls. Specifically, this alternative will
reduce and/or eliminate the potential risks posed by the contaminated shallow aquifer at the
HPIA Site. In addition, implementation of this alternative will not pose unacceptable
short-term risks or cross-media impacts. This interim action will be part of an overall remedy
which will attain the statutory requirement of protect!veness for the entire operable unit.
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TABLE 5
ESTIMATED COSTS OF SELECTED REMEDY
Component
Estimated Cost
Capital Costs:
Mobilization
Extraction Well System
Treatment Equipment
Demobilization
Pilot Studies
Engineering and Contingencies
Operation and Maintenance Costs:
System Operation
Effluent Sampling
Miscellaneous (Health and Safety)
Monitoring
TOTAL NET PRESENT VALUE
(using 5% discount rate)
$25,000
76,000(D
633,800
15,000
37,490
$787,290
224.940
$1,012,230
$224,200
18,300
52,400
56.600
$351,500
$7.6 Million
This cost will incur during years 1 through 3.
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This IRA alternative will comply with all Federal and North Carolina requirements (ARARs) which are
applicable or relevant and appropriate to its implementation. Specifically, the alternative will meet the
Federal Drinking Water MCLs and the North Carolina Water Quality Criteria for Groundwater for the
contaminants of concern at the site. The alternative will also comply with Pretreatment Standards and
NPDES criteria.
The selected remedy affords overall effectiveness proportional to its costs. This alternative is the
second most cost effective of the "treatment" alternatives evaluated. The no action alternatives is more
cost effective, but may not adequately protect human health and the environment. The Biological STP
Treatment Alternative is slightly more cost effective, but due to the unknown condition of the sewer
line, this alternative could result in significant cost increases for sewer line replacement.
The selected IRA alternative represents a permanent solution with respect to the principal threats posed
by the contamination within the shallow aquifer at the HPIA Site. Therefore, this alternative utilizes
permanent solutions for the shallow aquifer to the maximum extent practicable. This interim action
will be part of an overall remedy which will attain the statutory requirement of utilizing permanent
solutions to the maximum extent practicable for the entire HPIA Operable Unit.
Since treatment (via pretreatment and air stripping) is the principal element of this alternative, the
statutory requirement with respect to preference for treatment will be attained. In addition, this interim
action will be part of an overall remedy which will attain the statutory requirement of satisfying the
preference for treatment that reduces toxicity, mobility, or volume as a principal element.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The proposed remedial action plan identified Alternative 3, Biological Treatment, as the preferred
alternative. Alternative 4, Air Stripping, presented in the proposed remedial action plan and the
Feasibility Study Report requires an on-site air stripper to treat the extracted groundwater. The
possibility of adverse effects to the sewage treatment plant (STP) was raised by the State of North
Carolina. As a result, the Navy/Marine Corps, in consultation with the EPA and North Carolina,
selected Alternative 4 as the alternative providing the best balance of the nine criteria. This alternative
involves treatment of the extracted groundwater prior to discharging the effluent to the Hadnot Point
Industrial Area STP.
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12.0 RESPONSIVENESS SUMMARY
12.1 Overview
At the time of the public comment period, MCB Camp Lejeune and the Department of the Navy (DoN)
with the assistance of the United States Environmental Protection Agency (EPA) and the North
Carolina Department of Environment, Health, and Natural Resources (N.C. DEHNR) selected a
preferred interim remedial action alternative for the contaminated groundwater plumes in the shallow
aquifer at the HPIA Operable Unit located at MCB Camp Lejeune, North Carolina. The preferred
interim remedial action alternative specified in the Proposed Remedial Action Plan (PRAP) involved
extracting the contaminated groundwater, pretreating the groundwater, and then discharging the
pretreated water to an existing sewage treatment plant (STP) at the MCB for treatment and discharge.
Treatment of the groundwater at the STP would primarily involve aeration and biological treatment
(trickling filters). The treated groundwater would be discharged to a receiving river.
Judging from the comments received during the public comment period and from the attendance at the
public meeting, the local community does not appear to be concerned with the proposed actions to be
implemented at the site. No private citizens attended the public meeting nor did they submit any
comments during the comment period.
The purpose of this responsiveness summary is to identify the comments and concerns of the local
community regarding the selected interim remedial action, and to document how MCB Camp
Lejeune/DoN considered these comments and concerns during the" selection of the interim remedial
alternative. The remainder of this responsiveness summary discusses the background on community
involvement, and presents a summary of the comments received during the public meeting and public
comment period along with their corresponding responses.
12.2 Background on Community Involvement
No past community interest in the contamination at the HPIA Operable Unit has been documented.
This may be due to the fact that the site is located within an industrial area at the MCB.
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12.3 Summary of Public Comments and Responses
Comments raised during the HPIA Operable Unit public comment period and the public meeting are
summarized below. The comment period was held between May 14, 1992 and June 14, 1992. The
public meeting was held on May 14, 1992. The only comments received were from the Agency for
Toxic Substances and Disease Registry (ATSDR) and were technical questions/concerns regarding the
selected remedial action.
1. The Agency for Toxic Substances and Disease Registry (ATSDR) asked what kind of. models
would be used to determine air quality at the STP.
MCB Camp Leieune/DoN Response: An EPA air model (SCREEN) which is a very
conservative model has already been used to estimate potential air emissions resulting from
implementing the STP for the treatment of the groundwater. The results from the model
estimated that the concentrations of the identified VOC emissions from the STP would be
below the North Carolina acceptable ambient concentrations.
2. The ATSDR wanted to know how the STP would be upgraded.
MCB Camp Leieune/DoN Response: Clarified the misunderstanding - the STP would not be
upgraded, instead the sanitary sewer line that is planned to be used would be upgraded if
required.
3. The ATSDR was concerned if the STP could handle the groundwater for treatment.
MCB Camp Leieune/DoN Response: It is believed that the STP will be capable of treating the
groundwater, based on preliminary studies (see Final Pre-Design Report). MCB Camp
Lejeune and the DoN intend to conduct treatability studies during the design of the alternative.
4. The ATSDR recommended that since the STP is in close proximity to a recreation area, air
monitoring for volatile organic chemicals should be conducted for a short period of time after
beginning the treatment process and again when the process is at peak capacity. Analyses
should include determining concentrations of volatile organic chemicals such as benzene, vinyl
chloride, and other volatiles associated with both plumes and not be confined to TCE.
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MCB Camp Lejeune/DoN Response: This recommendation for air monitoring will he included
in the remedial design for the site and will become a requirement during the construction start-
up phase.
5. The ATSDR recommended that air monitoring stations should be at areas closest to the nearest
recreational areas and should be at heights that would be representative of the br&athmg zone
for a young child as well as an adult.
MCB Camp Leieune/DoN Response: Air monitoring stations will be located at areas closest to
the nearest recreational areas and will be at heights representative of (he breathing zone for ;t
young child as well as an adult.
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