NCD980557656_19930101_NC State University (Lot 86 Farm Unit 1)_FRCBERCLA FS_Revised Feasibility Study-OCR

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21 <
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Janm:ry 1995
BROWN AND CALDWELL
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CONTENTS
RECEIVED
MAR 151995 I
i:;UPERFUND SECTION
Page
LIST OF TABLES ............................ : . . . . . . . . . . . . . . . . . . . 111
LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV
SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V
CHAPTER 1.0 FEASIBILITY STUDY INTRODUCTION . . . . . . . . . . . . . . . . . . . 1-1
I. 1 Purpose and Organization of Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.2.1 Site Description and Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.2.2 Site History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.3 Present Nature and Extent of Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1.3.1 Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
1.3 .2 Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
1 .4 Contaminant Fate and Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
1.4.1 Chemical Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
1.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
End of Chapter 1.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
CHAPTER 2.0 IDENTIFICATION AND SCREENING OF TECHNOLOGIES . . . . . 2-1
2.1 Remedial Action Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1.1 Risk-Based Cleanup Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1.2 Applicable or Relevant and Appropriate Requirements . . . . . . . . . . . . . 2-3
2.1.2.1 Chemical-Specific ARARs for Soil . . . . . . . . . . . . . . . . . . . . 2-3
2.1.2.2 Chemical-Specific ARARs for Groundwater . . . . . . . . . . . . . 2-7
2.1.2.3 Location-Specific ARARs . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
2.1.2.4 Action-Specific ARARs . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
2.2 Estimation of the Volume and Concentration of Contaminated Media . . . . . . . . 2-22
2.2: 1 Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
2.2.2 Subsurface Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
2.3 General Response Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
2.3.'l No Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
2.3.2 Institutional Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
2.3.3 Containment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
2.3.4 Removal/Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
2.3.5 Containment/Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
2.3.6 Removal/freatment/Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
2.4 Identification and Initial Screening of Technology Types and Process
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
2.4.1 Screening Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26
2.4.2 Technology Descriptions and Evaluations . . . . . . . . . . . . . . . . . . . . . . 2-26
· 2.4.2.1 Initial Screening: Groundwater Medium . . . . . . . . . . . . . . . . 2-26
2.4.2.2 Initial Screening: Unsaturated Subsurface Soil Medium . . . . . 2-31
End of Chapter 2.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34
BROWN AND CALDWEU i FeasibiaJy StudJ Rq,ort • Sq,tember 1994
CONTENTS (continued)
CHAPTER 3.0 DEVELOPMENT AND SCREENING OF REMEDIAL
ALTERNATIVES ................................... .
3.1 Secondary Screening of Process Options ........................... .
3.1.1 Groundwater Medium ................................... .
3.1.2 Subsurface Soil Medium ................................. .
3.2 Development of Alternatives .................................... .
End of Chapter 3.0 .............................................. .
CHAPTER 4.0 DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES ..... .
4.1 Introduction ............................................... .
4.2 Individual Analysis of Remedial Alternatives for Subsurface Soils ......... .
4.2.1 Alternative No. I-No Action ............................. .
4.2.2 Alternative No. 2-Institutional Action ....................... .
4.2.3 Alternative No. 3-Containment/Capping ..................... .
4.2.4 Alternative No. 4-Soil Vapor Extraction ..................... .
4.2.5 Alternative No. 5-0n-Site Incineration ...................... .
4.2.6 Alternative No. 6-Low Temperature Thermal Desorption ......... .
4.3 Comparative Analysis of Soil Remedial Alternatives ................... .
4.3.1 Scoring Procedure ..................................... .
4.3.2 Scoring Analysis for Subsurface Soils ........................ .
4.4 Scoring .................................................. .
4.5 Summary of the Comparative Analysis of Remedial Alternatives for Soils .... .
4.6 Individual Analysis of Groundwater Remedial Alternatives ............... .
4.6.1 Alternative No. I-No Action ............................. .
4.6.2 Alternative No. 2-Institutional Action ....................... .
4.6.3 Alternative No. 3-Groundwater Extraction, Treatment, and
Discharge ........................................... .
4.6.4 Alternative No. 4-Biotreatment of Groundwater ................ .
4.7 Comparative Analysis of Groundwater Remedial Alternatives ............. .
4.7.1 Scoring Analysis for Groundwater .......................... .
4.8 Summary of the Comparative Analysis of Remedial Alternatives for
Groundwater ............................................... .
End of Chapter 4.0 .............................................. .
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
APPENDIX E
APPENDIX F
APPENDIX G
APPENDIX H
APPENDIX I
APPENDIX J
APPENDIX K
APPENDIX L
APPENDIX M
GLOSSARY OF PROCESS OPTIONS
EPA DIRECTIVES 9355.0-47S AND 9355.0-49S
CONDUCTING REMEDIAL INVESTIGATIONS/FEASIBILITY STUDIES AT
CERCLA MUNICIPAL LANDFILL SITES
EPA DIRECTIVE 9355.0-48S
SOIL VAPOR EXTRACTION
FIELD TESTS FOR SVE SYSTEM DESIGN
SYMPOSIUM ON INTRINSIC BIOREMEDIATION OF GROUND WATER
BIOREMEDIATION FIELD INITIATIVE SITE PROFILE
GROUNDWATER POLLUTION MICROBIOLOGY
FACTORS LIMITING THE REDUCTIVE DECHLORINATION OF CHLOROALKENES
CHLORINATED SOLVENT BIODEGRADATION BY METHANOTROPHS IN
UNSATURATED SOILS
EPA DIRECTIVE 9283 .1-06
FEDERAL SURFACE WATER CRITERIA
3-1
3-1
3-1
3-5
3-6
3-8
4-1
4-1
4-4
4-4
4-6
4-7
4-9
4-11
4-12
4-13
4-14
4-14
4-17
4-17
4-18
4-18
4-20
4-22
4-25
4-28
4-29
4-31
4-31
BROWN A.ND CA.LDWEU ii Fttaibility Study Reporr · September 1994
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LIST OF TABLES
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Number Page
2-1 ARARs and Other Pertinent Criteria for the Chemicals
Detected in the Soil at the Lot 86 Site . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
2-2 ARARs and Other Pertinent Criteria for the Chemicals
Detected in the Groundwater at the Lot 86 Site . . . . . . . . . . . . . . . . . . . 2-8
2-3 Location-Specific Applicable or Relevant and Appropriate
Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2-4 Action-Specific Applicable or Relevant and Appropriate
Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
4-1 Retained Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
BROWN AND CAWWEU iii FeasibilkJ StudJ Report· Septnn.hr 1994
LIST OF FIGURES
Number Page
1-1 NCSU Lot 86 Site Vicinity Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1-2 NCSU Lot 86 Site Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1-3
2-1
2-2
2-3
2-4
2-5
3-1
3-2
3-3
3-4
4-1
FS-2\7200TC.FS
NCSU Lot 86 Site Plan .................................. . 1-5
Remedial Action Objectives and Associated General Response
Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Groundwater Area Exceeding RAOs . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23
Soil Area Exceeding RAOs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24
Initial Screening of Technologies and Process Options
for Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27
Initial Screening of Technologies and Process Options for Soil . . . . . . . . 2-32
Applicable Technologies and Process Options for Groundwater . . . . . . . . 3-2
Applicable Technologies and Process Options for Soil . . . . . . . . . . . . . . 3-4
Alternatives Retained Following the Secondary Screening of
Technologies and Process Options for Groundwater . . . . . . . . . . . . . . . . 3-7
Alternatives Retained Following the Secondary Screening of
Technologies and Process Options for Unsaturated Soils . . . . . . . . . . . . 3-8
Relationship of Screening Criteria to the Nine Evaluation Criteria . . . . . . 4-2
BROWN AND CAWWEU iv FeasibiiilJ Study Rq,or1 -SepUmba-1994
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SUMMARY
The Feasibility Study (FS) has been conducted in accordance with the requirements of
the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) and as specified
by the' Administrative Order on Consent for Remedial Investigation/Feasibility Study (EPA
Docket No. 91-24-C). The FS Report is the last submittal in the RI/FS process and follows the
completion and EPA acceptance of the RI Report and issuance of the Risk Assessment. The
purpose of the FS was to develop and assess remedial alternatives for the groundwater and soil
in the areas of the site.
The results of the RI can be summarized as follows:
■ The waste materials were disposed below grade in the disposal trenches.
No evidence of surface spillage or disposal was observed.
■ The site soils are generally fine-grained, low-permeability silts and clays
which limit migration and groundwater flow.
■ The VOCs are the most prevalent chemicals in the soil and groundwater.
Other chemicals, including semivolatile organics, pesticides, and in-
organics, as well as tritium and carbon-14, were only observed in trace
concentrations in very few wells.
■ The primary migration pathways for the site are vertical transport through
the subsurface soils and vertical and horizontal transport of chemicals
through the groundwater matrix.
■ VOCs have migrated vertically from the trenches through the unsaturated
zone to groundwater. Contaminant concentrations increased near the
saturated zone. No nonaqueous phase liquids were observed; all chemi-
cals were solubilized.
■ VOCs in groundwater have migrated with the groundwater gradient in the
shallow saturated zone a distance of approximately 300 feet from the site.
The nearest receptor is Richland Creek, approximately 3,000 feet from
the site. Vertical migration of chemicals in groundwater appears to be
limited as concentrations decline with depth.
The two media of concern at the site are subsurface soils and groundwater. Site-specific
remedial action objectives (RA Os) for groundwater and subsurface soil were established. These
RAOs included achieving maximum contaminant levels (MCLs) (in groundwater). The RAOs
for subsurface soil were developed to be protective of groundwater (meeting RAOs).
i
BROWN AND CAWWEU V FemibiliJJ Study Report• January 1995
SUMMARY
The initial phase of the FS was the identification and screening of technologies for
applicability to remediate the two contaminated media at the site, namely subsurface soils and
groundwater. These technologies were screened based on implementability, effectiveness, and
cost. The technologies carried forward were used to develop preliminary alternatives. These
alternatives were developed for further screening. These included no action, institutional action,
and active remediation alternatives for both media. These alternatives were further screened
and developed using the three criteria of effectiveness, implementability, and cost. This resulted
in the retention of ten final alternatives-six for subsurface soils and four for groundwater-to
be analyzed in detail. These final alternatives are presented in Table I.
Table 1 Final Alternatives for Detailed Analysis
Alternative No. 1 For Subsurface Soil No action
Alternative No. 2 Institutional action
Alternative No. 3 Containment/capping
Alternative No. 4 Soil vapor extraction (SVE)
Alternative No. 5 Incineration
Alternative No. 6 Thermal Desorption
Alternative No. 1 For Groundwater No action
Alternative No. 2 Institutional action
Alternative No. 3 Groundwater treatment
Alternative No. 4 Biotreatment
Chapter 4 contains the detailed analysis of the ten alternatives that were finally selected.
These alternatives were analyzed using the seven EPA evaluation criteria shown on Figure 4-1.
The other two criteria, state and community acceptance, were not part of this analysis. The
alternatives for each media were evaluated separately, first by individual then comparative
analysis against each of the criteria. The results of the analysis are as follows.
For subsurface soils, the no action and institutional action alternatives do not actively
reduce the toxicity, mobility, and volume of the contaminated soils. The institutional action
alternative reduces potential exposure by restricting access and land use at the site. Neither of
these alternatives will meet the RAOs and target risk levels.
The containment/capping alternative will reduce the mobility of the contaminants by
eliminating stormwater infiltration which could solubilize the chemicals. It is a presumptive
remedy for CERCLA landfill sites (EPA Directives 9355.0-47FS and -49FS, September 1993),
BROWN AND CALDWEU vi F«uibiliJJ Study Report. January 1995
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SUMMARY
which means it is a preferred technology for landfill remediation. However, containment/
capping does not reduce the toxicity or volume of contaminants at the site.
The SVE, incineration, and thermal desorption alternatives provide treatment to reduce
the toxicity and volume of chemicals. SVE is a presumptive remedy for volatile organics in
soils. However, SVE will require further investigation and pilot testing to determine if it can
be applied in the low permeability soils at the Lot 86 site. Incineration and thermal desorption
will achieve the RAOs in soils and do not transport any contaminants off-site, but instead
destroys the chemicals and treated soils are left in place. However, they also add exposure risks
associated with excavation of the source materials as well as community opposition that typi-
cally follows proposed use of on-site incinerators.
For groundwater, the evaluation showed little difference between the no action, institu-
tional action, and the biotreatment alternatives. Only the groundwater treatment alternative
scored slightly lower. The no action and institutional action alternatives rely solely on natural
attenuation to treat the groundwater, which will take more than 30 years to achieve the ARARs.
The institutional action alternative reduces the exposure risk by restricting site access and
groundwater usage. The groundwater treatment alternative will expedite the reduction of chemi-
cals in groundwater and the treated water will meet the ARARs. It also will provide a barrier
to limit future migration. However, the groundwater is still not expected to achieve ARARs
within 30 years, due to the dense, low permeability soils.
The biotreatment alternative is an innovative, closed-loop system that will provide a
downgr~dient barrier to prevent further migration as well as an infiltration gallery which will
help flush existing contaminants through the system and enhance biodegradation. Since it is
an innovative technology, it would be suitable for implementation as a development opportunity
for the EPA SITE program and could have applicability to similar site cleanup scenarios in
Region IV.
FS-2\7200SUM.FS
BROWN AND CAWWEU vii FmsibiliJy Study Rq,ort • January 1995
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CHAPTER 1.0
FEASIBILITY STUDY
INTRODUCTION
North Carolina State University (NCSU) contracted with Brown and Caldwell Consul-
tants (B,CC) to conduct a remedial investigation/feasibility study (RI/FS) at the Lot 86 site at
Raleigh, North Carolina (NCSU Lot 86). The site was listed on the National Priority List
(NPL), as defined in Section 105 of the Comprehensive Environmental Response, Compensation
and Liability Act (CERCLA), as amended by the Superfund Amendments and Reauthorization
Act (SARA) in October 1989 (EPA, 1990). The Remedial Investigation (RI) for the Lot 86 site
was concluded with the RI Report dated June 1994.
The Feasibility Study (FS) is being conducted in accordance with the requirements of
the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) and as specified
by the Administrative Order on Consent for Remedial Investigation/Feasibility Study (EPA
Docket No. 91-24-C). The FS report is the last submittal in the RI/FS process. This document
presents the results of the FS performed to identify the most cost-effective, technically sound
approach to remediate the site. This chapter presents the purpose and scope of the FS, the
organization of the FS report, and pertinent background information including the site descrip-
tion and history, previous site investigation and cleanup programs, the extent and nature of
contamination, and estimated contaminant fate and transport.
1.1 PURPOSE AND ORGANIZATION OF REPORT
The purpose of this report is to present the methodology used in accomplishing the FS
for the Lot 86 site. The FS develops and assesses remedial alternatives for the soil and the
groundwater in areas of the site. This FS report has been prepared following the guidance
given in the Office of Emergency and Remedial Response Directive 9355.3-01.
The FS report is organized to review the site history and to provide a description of the
evaluation process followed in the FS. The background information, including the site history
and the nature and extent of contamination at the site, is reviewed in Chapter I. Chapter 2
presents the remedial action objectives, general response actions, and the identification and
screening of potential remedial technologies for applicability to the site. In Chapter 3 the
remedial technologies are assembled into comprehensive remedial alternatives to address the
entire site and these alternatives are generally screened. The alternatives are analyzed in detail
in Chapter 4 and a comparative analysis is performed against the EPA's evaluation criteria to
determine the most suitable alternatives for each media at the site.
BROWN AND CAWWEIL 1-1 FeasibiliJJ StudJ Rq,ort • January 1995
CHAPTER 1. FEASJBJUTY STUDY JNTRODUCTJON
1.2 BACKGROUND
Background information on the Lot 86 site includes the site description, site history, and
a summary of the previous studies.
1.2.1 Site Description and Location
The NCSU Lot .86 site is located on the west side of Raleigh, Wake County, North
Carolina, near Carter-Finley Stadium, immediately south of the southern right-of-way of Wade
Avenue Extension (Wade Avenue), a limited access highway (Figure 1-1).
Wade Avenue connects with Interstate 40 (I-40), which is a heavily traveled
thoroughfare carrying commuter traffic between Raleigh and Research
Triangle Park, as well as interstate traffic.
The 1.5-acre site (Figure 1-2) is located on and surrounded by state-
owned property. The site is secured with a chain link fence with a padlock on the gate. The
site is covered with grass and weeds and no structures are present. A large grass-covered open
area, west of the site and north of Carter-Finley Stadium, is used for parking during stadium
· events. The dirt road leading into this area from Old Trinity Road is used as a jogging path
by NCSU students, faculty, and area residents. Trees along the fence north of the site screen
the view from Wade Avenue. A pine forest borders the site to the east and south. The nearest
water supply well is located approximately 2,000 feet southeast of the site (Figure 1-1) at the
Medlin residence.
1.2.2 Site History
NCSU selected Lot 86 of Farm Unit No. I in 1969 as a burial site for
hazardous chemical waste and low level radioactive waste generated in the
University's educational and research laboratories. The site was divided into
two separate areas as shown on Figures 1-2 and 1-3; the western area to
receive hazardous chemical waste, and the eastern area to receive low level
radioactive waste (LLRW). Burial of waste was discontinued in November
1980 to comply with regulations promulgated under the Resource Conservation and Recovery
Act (RCRA).
The chemical wastes were placed in trenches located in the northwest portion of the site
(Figure 1-3). The trenches were approximately IO feet deep and varied from 50 to 150 feet
long. After filling, about 2 feet of native soil which was excavated during trench construction
was used as cover material. Later, the disturbed area was seeded with grass. The University
records show that 22 trenches totalling approximately 2,000 linear feet were used. The types
of chemicals reported to have been buried at the site include solvents, pesticides, inorganics,
acids, and bases. Although some of the liquid chemicals disposed of during the initial site
operations were poured into the trenches, both liquid and solid chemicals were generally buried
in metal, glass, or plastic containers.
BROWN AND CAWWEU 1-2 FeasibiliJJ Study Rq,ort · JanU4rJ 1995
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LOT 86
SITE
a
<(
0 a: g r-REX HOSPITAL
ii:: w D LAKE BOONE TRAIL
::,
..J OJ
WADE A VE. EXTENSION
~ CARTER-FINLEY
STADIUM
.~--'(-... MEDLIN RESIDENCE
-1 OLD TRINITY ROAD
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STAN
, FAIRGROUNDS
Figure 1-1 North Carolina State University
Lot 86 Site Vicinity Map
Figure 1-2 North Carolina State University
Lot 86 Site Study Area
BG Brown and Ca-
Consunan1s
L-2
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Ir---------~--------,
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1,
"" 0 100
SCAI..£ : ,·-100'
LEGEND
ElCISTING FENCE
OiDIICAL WASTE DISPOSAL TRENCH
URW DISPOSAL TRENCH
200
-·-·-·-
CMEMICAL WASTE
DISPOSAi. NIU.
. -----/l.OW1.£'1El."""""""1 II I;;-( WAST( (LLRW) DISPOSAi. ~
. j /II I
l l
I J \ t,/ \ /.
l//
Fiqure 1 -3
NCSU LOT 86
SITE PL.AN
CHAPTER I. FEASIBIUTY STUDY INTRODUCTION
NCSU reported on the CERCLA Section I03(c) Hazardous Waste Notification form filed
June 8, 198 I, that it had disposed of approximately 300,000 cubic feet or about 11,000 cubic
yards of chemical waste at the site. NCSU indicates that this quantity includes lightly contami-
nated soil and water as well as actual waste materials.
Radiological wastes were buried in the eastern portion of the site in trenches approxi-
mately 6 feet deep and 50 to 120 feet long. Nine trenches were reportedly excavated and used
for LLRW disposal. The depth of waste in the bottom of the trenches was reported to be 2 feet
with 4 feet of native soil cover material. Records concerning waste disposal in this area are
maintained by the NCSU Radiation Protection Office in complete conformance with applicable
Atomic Energy Commission/Nuclear Regulatory Commission (AEC/NRC) regulations. These
records indicate that the wastes were properly disposed at the site. Most of the LLRW waste
is in solid form, primarily animal carcasses, which range in size from rats to whole sheep. The
carcasses were frozen when buried and were not containerized. Radionuclides present in the
waste include tritium, carbon-14, iron-59, phosphorus-30, and phosphorus-32.
The site was placed on the National Priority List (NPL) in October 1984, based on
results from an inspection completed in June of that year. The EPA and North Carolina
Division of Solid Waste Management completed hazard ranking score sheets for the site and
determined the degree of contamination was sufficient to warrant inclusion on the NPL.
1.3 PRESENT NATURE AND EXTENT OF CONTAMINATION
The two source areas at the Lot 86 site are the chemical waste disposal trench area and
the LLRW trench area. These areas were used for waste burial from 1969 until 1980. A
substantial amount of information concerning the trenching operation, the trench construction
and the waste type and condition has been assembled for use in the RI/FS. All wastes were
reportedly buried and no surface spillage or disposal had occurred.
A significant amount of site data was also collected during previous investigations.
Thirty-three wells had been installed near the Lot 86 site prior to this RI to assess the ground-
water conditions, and ongoing sampling of these wells has been conducted since the early
1980s. The data collected during these previous investigations showed that volatile organic
compounds (VOCs) had leached from the chemical trenches into the groundwater. The solu-
bilized chemicals had migrated to the west/northwest, the direction of groundwater flow. The
previous data showed a VOC plume in the shallow groundwater extending approximately 150
feet from the site with the highest detected concentrations being near the landfill. These
included chloroform at 390 milligrams per liter (mg/I), diethylether at 460 mg/I,
1,2-dichloropropane at 142 mg/I, and benzene at 128 mg/I.
The RI confirmed these conclusions as well as determined the current site conditions.
The results were as follows.
BROWN AND CAWWEU 1-6 FeasibililJ StudJ Rq,on • January 1995
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CHAPTER I. FEASIBILJTY STUDY INTRODUCTION
; 1.3.1 Soils
'
Little evidence of surface impact or of wide horizontal spreading of the chemicals from
the trenches into the unsaturated soils was observed during the RI. This confirms the previous
data which showed that VOCs were generally migrating vertically down from the trenches into
the saturated zone and solubilizing in the groundwater. The most prevalent chemicals in the
soils were VOCs, including acetone, chloroform, benzene, methylene chloride, carbon tetra-
chloride, and trichloroethene (TCE). Other chemicals, including semivolatile organics and
pestiddes as well as radioactive parameters, were only identified at trace concentrations in a
very limited number of locations. The impacted soils in the unsaturated zone were detected
near the chemical waste disposal trenches, primarily along the northwest boundary of the
landfill site. Contaminants in the surface and shallow unsaturated soils were generally non-
detectable, with only trace levels detected. The concentration of chemicals in soils increased
near the top of the saturated zone.
, In the saturated soils, the most prevalent chemicals were also VOCs. These compounds
were at relatively high concentrations in the wells near the chemical waste trenches. The results
showed the highest concentrations in the top 5 to 10 feet of the saturated zone, with levels
decreasing significantly below that level. Trace concentrations of VOCs were detected in the
deeper soil samples.
The most prevalent inorganic chemicals in soils, detected in all of the 49 samples, were
iron, aluminum, manganese, and lead. Also detected at a high frequency were zinc and copper,
which were found in 45 and 40 out of 49 samples, respectively. All of the aforementioned
inorganics were present at high concentrations in the blank samples. Additionally, blank
concentrations for iron, lead, and copper were the maximum concentrations detected for those
parameters. In general, inorganic concentrations were consistent with depth.
1.3.2 Groundwater
The most prevalent chemicals in groundwater were the same VOCs observed in the soils
and in the previous investigations. Chloroform, methylene chloride, benzene, and carbon
tetrachloride were the most frequently detected in the groundwater during the RI. The shallow
groundwater evidenced the most impact with only trace levels of contaminants detected in the
deep wells. As in the previous investigations, the highest concentrations were observed
immediately downgradient of the landfill waste trenches, with decreasing levels away from the
site.
Maximum concentrations measured in this RI were well below those observed during the
investigations conducted in the mid-1980s, indicating that a release occurred previously but has
since diminished. Also, the RI showed that the concentrations in existing wells were below ' those in the new shallow wells, reflecting a decline in concentration with depth since the
existing wells are screened at a lower elevation than the new wells. Detectable VOCs measured
during the RI extend horizontally to MW-15, approximately 300 feet downgradient of the site,
BROWN AJ:ID CAWWEU 1-7 FmsibiuJJ Stud1 Rrpor1 -January 1995
CHAPTER I. FEASJBIUTY STUDY INTRODUCTION
with levels just exceeding the federal MCLs for the detected chemicals. This shows that the
contaminants have migrated with the groundwater gradient over the last l O years, which is
expected.
The inorganic chemical results showed elevated levels of some metals in the ground-
water, including manganese, arsenic, and lead. Arsenic was measured above the MCL (50
micrograms per liter (µg/1)) in the deep well, MW-36D, at 110 µg/1, although arsenic was not
detected in the shallow well at that location. Lead was detected above the North Carolina
groundwater standard (15 µg/1) in wells MW-36S and MW-37 at 21 and 31 µg/1, respectively.
The most prevalent metal was manganese, which was detected above the MCL (50 µg/1) in
seven of the eight new wells, including the two background wells (MW-34S and MW-34D).
The highest concentration was observed in MW-36S at 20,000 µg/1. No inorganic sampling and
analysis has previously been conducted at the site.
1.4 CONTAMINANT FATE AND TRANSPORT
were:
Two potential routes of contaminant migration were identified at the site. These routes
■
■
Vertical transport of chemicals from the waste trenches through the
subsurface soils by solubilization of the chemicals into surface water
percolating through the soil column, and
Vertical and horizontal transport of solubilized chemicals through the
groundwater matrix.
Migration pathways depend on the physical characteristics of the site and the physical
and chemical properties of the contaminants (i.e., solubility, vapor pressure, and partition
coefficient). Chemical migration at the site is discussed below.
l .4.1 Chemical Migration
Many different types of chemicals and radioactive isotopes generated in the University's
educational and research laboratories were disposed at the site. These chemical and low level
radioactive wastes were buried in subsurface trenches, which were dug in the low permeability
clay and silt soils present at the site. These soils, which were also used for the cover material,
tend to promote surface water runoff and limit infiltration of water which could contact the
contaminants.
Several chemicals, including semivolatile organics, pesticides, and most inorganics, have
a low solubility, sorb strongly onto the fine-grained soils at the site, and thus are persistent.
These compounds showed very little migration from the site trenches and were only observed
at trace concentrations in a few samples.
BROWN A.ND CALDWEU 1-8 FeasibiiiJJ Study Report. Ja.nUIJl11995
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CHAPTER J. FEASJBJUTY STUDY INTRODUCTION
The more mobile chemicals, primarily the VOCs, have migrated from the trenches
through the soil matrix, into groundwater. These chemicals are solubilized in infiltrating surface
water, which carries the chemicals to the top of the groundwater. The migration of chemicals
has been retarded due to the low permeability of the unsaturated soils which limit the amount
of chemicals which reach the saturated zone. These chemicals solubilize into and are trans-
ported by the shallow groundwater. Vertical migration of the chemicals appears to be limited
to the top JO to 15 feet of the saturated zone. The saturated soils become more dense and less
permeable with depth. The chemicals are moving in the shallow groundwater in the direction
of the flow gradient toward Richland Creek. The fate and transport calculations in the RI
showed .that the concentrations of the primary contaminants at the site will be below surface
water criteria at the creek.
Contaminant migration is also affected by biodegradation, sorption, and soil character-
1st1cs. The VOCs measured at the site are subject to biodegradation and sorption in the
subsurface which will increase the rate of their decline. In addition, the fine-grained, low-
permeability soils will also limit contaminant migration.
The RI data indicate that the concentrations in groundwater near the landfill have already
declined from previous investigations. The previous data showed total maximum VOC concen-
trations over 1,000 parts per million (ppm). Current data show total maximum VOC concen-
trations near JOO ppm, which suggests a reduction in any releases from the landfill. No
nonaqueous phase liquids (NAPLs) were observed in soils or groundwater during the RI. Only
solubilized chemicals were found, with the maximum chemical concentrations observed in the
shallow groundwater. Concentrations in the unsaturated soils increased at the saturated cone
and then 'declined below the top of the groundwater zone. Concentrations in the groundwater
were only a fraction of the saturation concentrations for each chemical which is an indicator
of an NAPL being present.
1.5
'
SUMMARY
After evaluating the data from the RI, several points may be summarized:
■ ' The waste materials were disposed below grade in the disposal trenches.
No evidence of surface spillage or disposal was observed.
■ The site soils are generally fine-grained, low-permeability silts and clays
which limit migration and groundwater flow. . , The VOCs are the most prevalent chemicals in the soil and groundwater .
Other chemicals, including semivolatile organics, pesticides, and inor-
ganics, as well as tritium and carbon-14, were only observed in trace
concentrations in very few wells.
BROWN A.ND CAWWEU 1-9 FeasibililJ SludJ Rq,ort -Jan-,, 1995
CHAPTER I. FEASIBIUTY STUDY INTRODUCTION
■
■
■
FS-2\7200CHI.FS
The primary migration pathways for the site are vertical transport through
the subsurface soils and vertical and horizontal transport of chemicals
through the groundwater matrix.
VOCs have migrated vertically from the trenches through the unsaturated
zone to groundwater. Contaminant concentrations in the unsaturated soils
increased near the saturated zone. No nonaqueous phase liquids were
observed; all chemicals were solubilized.
VOCs in groundwater have migrated with the groundwater gradient in the
shallow saturated zone a distance of approximately 300 feet from the site.
The nearest receptor is Richland Creek, approximately 3,000 feet from
the site. Vertical migration of chemicals in groundwater appears to be
limited as concentrations declined with depth.
BROWN A.ND CAWWEU 1-10 Feasibilily Study Report• January 1995
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CHAPTER 2.0
IDENTIFICATION AND
SCREENING OF TECHNOLOGIES
This chapter presents the initial phase of the Feasibility Study (FS) for the Lot 86 site.
General remedial action objectives (RAOs) are presented and preliminary site specific soil and
groundwater cleanup objectives are developed from applicable or relevant and appropriate
requirements (ARARs). The volume and concentration of media requiring remediation are
estimated and general response actions which could be applied to meet the cleanup objectives are
identifiel Potential technology types and process options for the soil and/or groundwater
remediation at the Lot 86 site are'identified, evaluated and screened for inclusion in remedial
alternatives for the site.
2.1 REMEDIAL ACTION OBJECTIVES
RAOs are numerical cleanup objectives for specific compounds in specific media to
prevent exposure to contaminants in excess of public health or environmental standards. RAOs
address the contaminants and the pathways of potential concern. As stated in Section 1.5, the
media of concern at the Lot 86 site are subsurface soil and groundwater. Based on the results
of the Remedial Investigation (RI), surface soils are not a media of concern at the site.
General RAOs are presented on Figure 2-1. Specific cleanup objectives
are developed from ARARs. The final selection of ARARs and cleanup goals
will be performed by EPA as part of the record of decision.
2.1.1 Risk-Based Cleanup Objectives
The baseline risk assessment (BRA) is central to establishing cleanup levels. Major goals
of the cleanup objectives are to protect human health to a cancer risk range of 10·4 to I 0-6 for
carcinogens and to meet a threshold dose limit for noncarcinogenic chemical toxicants. Many
of the issues and assumptions which will be addressed in the BRA, such as exposure pathway
identification, land use assumptions, and institutional controls, are essential to the development
of risk-based cleanup levels.
As of this date the EPA-sponsored BRA is not yet completed. Thus, the guidance to be
obtained from this document is not yet available. The RAOs will be refined after receipt and
review of the EPA BRA.
BROWN AND CAWWEU 2-1 Fearibilily Study Report -January 1995
MEDIA
I. Groundwater
2. Subsurface
soils
FS\7200FJG.2-l
REMEDIAL ACTION OBJECTIVES
1-1 For human health:
Prevent exposure to contaminated water.
For environmental protection:
1-2 Prevent further groundwater quality degradation.
2-1 For human health:
Prevent exposure to contaminated soils.
For environmental protection:
2-2 Prevent further quality deterioration.
GENERAL RESPONSE ACTIONS
No action
Institutional action
Containment
Containment/treatment
Removal/disposal
Removal/treatment/disposal
No action
Institutional action
Containment
Containment/treatment
Removal/disposal
Removal/treatment/disposal
Figure 2-1 Remedial Action Objectives and Associated General Response Actions
liiill -11!!!!1 --- - - - - - - - - - - - - -
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CHAPTER 2. IDENTIFICATION AND SCREENING OF TECHNOWGIES
2.1.2 Applicable or Relevant and Appropriate Requirements
CERCLA 12l(d) requires that remedial actions comply with ARARs of federal and state
laws. Applicable requirements are those which specifically address a hazardous substance,
pollutant, contaminant, remedial action, location, or other circumstance found at a CERCLA site
( 40 CFR Part 300.400(g)). Relevant and appropriate requirements are those that, while not
applicable to the hazardous substance, pollutant, contaminant, remedial action, location, or other
circumstance at a CERCLA site, address situations sufficiently similar to those encountered at
the CERCLA site that their use is well suited to the particular site (40 CFR Part 300.400(g)).
Only those requirements which are both relevant and appropriate must be complied with.
ARARs fall into three categories: chemical-specific, location-specific, and action-specific
requirements. Chemical-specific requirements define acceptable exposure levels to specific
chemicals. Chemical-specific ARARs that must be met in groundwater and soils may also be
referred ,to as discharge criteria, action limits, or cleanup standards or levels. Location-specific
requirements are restrictions placed on the concentration of hazardous substances or on the
performance of activities because they occur in sensitive locations such as wetlands. Action-
specific requirements are controls or restrictions on particular treatment, storage, and disposal
activities related to the management of hazardous waste.
In addition to ARARs, other relevant criteria are considered in developing cleanup levels.
These "to-be-considered" criteria (TB Cs) are advisories issued by the federal or state government
that are not legally binding. As such, they do not have the enforcement status of the ARARs;
however, they are considered along with ARARs in determining site-specific cleanup levels.
Chemical-, location-, and action-specific ARARs and TBC criteria for the Lot 86 site are
discussed below.
2.1.2.1 Chemical-Specific ARARs for Soil
Human receptors may be exposed to chemicals in surface and subsurface soils as a result
of incidental ingestion of soils, dermal contact, and inhalation. The greatest exposure occurs
through ingestion by people living or working on the site. Exposure via inadvertent ingestion
of soil only occurs if chemicals of potential concern are located within the surficial soils, as is
not the case at the Lot 86 site. If excavation occurred at the site, however, subsurface soils may
be excavated and redistributed to the surface. Soil contaminants leaching into the groundwater
may also result in exposure through drinking water.
ARARs and other pertinent criteria (TB Cs) for the contaminants
measured at the Lot 86 site are presented in Table 2-1. As there are no specific
generic cleanup levels established by the EPA or the North Carolina Division
of Envir<;>nmental Management (NCDEM) for soils (analogous to the maximum
contaminant levels [MCLs] for drinking water), there are no chemical-specific
standards which are actually ARARs for the soil cleanup levels at the site. There are'.'however,
BROWN A.ND CAWWEU 2-3 Fea.sibiiiJJ StwlJ Repon -JanU11.ry J99S
Table 2-1 ARARs and Other Pertinent Criteria for the Chemicals Detected in the Soil at the Lot 86 Site
Concentration, mg/kg
Parameter TCLP toxicity
threshold,' mg/e USEPA land disposal NOAA ER-L' NOAA ER-M' Range of background Typical range in
restriction treatment levelb samplesd the Raleigh areae
Volatiles:
Acetone -r 160 --0.0053 -0.047 --'
Benzene 0.5 36 --0.0055 -0.008 --'
Bromodichloromethane ----0.0055 -0.008 --'
Bromoform -15 --0.0055 -0.008 --'
2-Butanone (MEK) 200.0 36 --0.0055 -0.008 --'
Carbon Disulfide --" --0.0055 -0.008 _g
Carbon Tetrachloride 0.5 5.6 --0.0055 -0.008 _g
Chlorobenzene 100.0 5.7 --0.0055 -0.008 --'
Chloroform 6.0 5.6 --0.0055 -0.008 --'
Dibromochloromethane ----0.0055 -0.008 _g
I, 1-Dichloroethane -7.2 --0.0055 -0.008 --'
1,2-Dichloroethane 0.5 7.2 --0.0055 -0.008 --'
I, 1-Dichloroethene 0.7 33 --0.0055 -0.008 --'
1,2-Dichloroethene, total -33 --0.0055 -0.008 --'
cis-1,2-Dichloroethene -------'
trans-1,2-Dichloroethene -33 -----'
1,2-Dichloropropane -18 --0.0055 -0.008 _g
Ethylbenzene ----0.0055 -0.008 --'
2-Hexanone ----0.0055 -0.008 --'
Methylene Chloride -33 --0.002 -0.008 _g
4-Meth y 1-2-Pentanone ----0.0055 -0.008 --'
I, 1,2,2-Tetrachloroethane -42 --0.0055 -0.008 --'
Tetrachloroethene 0.7 5.6 --0.0055 -0.008 _g
Toluene -28 --0.0055 -0.008 --'
I, I ,I-Trichloroethane -5.6 --0.0055 -0.008 --'
I, 1,2-Trichloroethane -5.6 --0.0055 -0.008 --'
Trichloroethene 0.5 5.6 --0.0055 -0.008 _g
Vinyl chloride 0.2 33 --0.0055 -0.008 _g
Xylenes, total -28 --0.0055 -0.008 --'
-------------------
____ ::::;.::;:: - - - - - - - - - - - - -
Table 2-1 ARARs and Other Pertinent Criteria for the Chemicals Detected in the Soil at the Lot 86 Site (continued)
Concentration, mg/kg
Parameter TCLP toxicity
threshold.' mg/I USEPA land disposal NOAA ER-L' NOAA ER-M' Range of background Typical range in
restriction treatment .lcvelh -samplcsd -the Raleigh areac -
Semi-Volatiles:
Benzo(a)anthracene -8.2 0.230 1.600 0.15 -0.42 _g
Bis (2-Ethylhexyl) Phthalate -28 --0.15 -0.37 _g
Chrysene -8.2 0.400 2.800 0.15 -0.58 _g
Diethylphthalate -28 --0.15 · 1.2 _g
lsophorone ----0.15 -0.25 _g
Naphthalene -3.1 0.340 2.100 0.15 -0.25 _g
Nitrobenzene 2.0 14 --0.15 -0.25 _g
Phenanthrene --0.225 1.380 0.15 -0.25 _g
Pyrene --0.350 2.200 0.15 -0.68 _g
Pesticides and PCBs:
b-BHC -0.66 --0.001 -0.0015 _g
g-BHC (Lindane) 0.4 0.66 --0.001 · 0.0015 _g
Chlordane, total 0.03 0.13 0.0005 0.006 0.001 -0.0015 _g
p,p'-DDE -0.087 0.002 0.015 0.002 -0.003 _g
p,p'-DDT -0.087 0.001 0.007 0.002 -0.003 _g
Dieldrin -0.13 0.00002 0.008 0.002 -0.003 _g
Arochlor-1260 --0.0501 0.4001 0.02 I 5 -0.0325 _g
Metals:
Aluminum ----4,400 -29,000 <25,000
Arsenic 5.0 -33 85 I -110 <3.4
Barium 100.0 ---22.5 · 440 <250
Beryllium ----0.5 -2.1 <I
Cadmium 1.0 -5 9 0.5 -6 _g
Calcium ----550 -3,100 2,900
Chromium 5.0 -80 145 I -40 <25
Cobalt ----5.5 -46 <3
Copper --70 390 3 -140 15
Iron ----14,000 -94,000 <12,500
Lead 5.0 -35 I 10 1.5 -110 15
Magnesium ----550 -12,000 1,500
Manganese ----100 -4,000 <175
---------- - --------
Table 2-1 ARARs and Other Pertinent Criteria for the Chemicals Detected in the Soil at the Lot 86 Site (continued)
Concentration, mg/kg
Parameter TCLP toxicity
threshold,' mg/I USEPA land disposal NOAA ER-L' NOAA ER-M' Range of background Typical range in
restriction treatment levelb samplcsd the Raleigh areac
Metals: (continued)
Mercury 0.2 h 0.15 1.3 0.05 -0.124 0.16 -5.1
Nickel --30 50 4.5 -30 6 -12
Potassium ----550 -9,000 <9,000 Vanadium ----6 -260 25 -60
Zinc --120 270 II -230 _g
Radioactive:
Gross alpha (adjusted) (pCi/L) ----_g _g
Tritium ----<0.2 0.1
' 40 CFR 261.24.
' 40 CFR 268.43. Treatment levels shown are for P and U listed wastes containing the constituent.
' "ER-L" indicates Effects Range-Low and "ER-M" indicates Effects Range-Median. Values apply to sediments. Source: Region IV Waste Management
Division, Sediment Screening Values for Hazardous Waste Sites, January 27, 1992.
" Results from Remedial Investigation at the Lot 86 site; Remedial Investigation Report, Brown and Caldwell, June I 0, 1994. Background samples include those
from: SB-29, SB-30, SB-31, MW-34D, and are based on one-half the detection limit where maximum sample concentration is less than detection limit.
c Shacklette and Boerngen, Element Concentrations in Soils and Other Surficial Materials of the Conterminous United States, U.S. Geological Survey,
Professional Paper 1270, 1984.
' "-" indicates. level not established.
g Data not available.
~ Treatment method specified rather than treatment level.
' Value is for total PCBs.
FS-2\72001'2-I .FS
--1 ------ -- -- -- - -
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CHAPTER 2. IDENTIFICATION AND SCREENING OF TECHNOWGIES
ARARs for aspects of the remediation, including land disposal pretreatment levels and threshold
concentrations in a Toxicity Characteristic Leaching Procedure (TCLP) extract which cause a
waste to be classified as hazardous. Other relevant criteria (shown in Table 2-1) include the
NOAA Effects Range (ER) indicators (for sediments only), contaminant concentrations measured
in the background samples during the RI, and typical concentrations in soils in the Raleigh area.
Because the EPA considers the shallow groundwater zone as a potential future drinking
water source, subsurface soil cleanup levels will be determined based on soil levels necessary to
meet the North Carolina drinking water standards. Current knowledge of the site and site
contaminants suggests that soil RA Os for protection of groundwater will be driven by chloroform,
due to its high concentration and relative mobility in groundwater. In the absence of the EPA-
sponsored BRA, an RAO of 50 milligrams per kilogram (mg/kg) chloroform for soil is proposed
to achie~e the North Carolina drinking water standard of 0.10 milligrams per liter (mg/I)
chloroform downgradient from the localized source area.
2.1.2.2 Chemical-Specific ARARs for Groundwater
ARARS and other pertinent water standards for the contaminants
measured at the Lot 86 site are presented in Table 2-2. Although the surficial
aquifer at the Lot 86 site is not currently a source for drinking water, for the
purpose of this FS a conservative approach is taken and the surficial aquifer is
viewed as a potential drinking water source. Thus, groundwater ARARs for the
site are the North Carolina groundwater quality standards and federal and state
drinking water standards. The North Carolina groundwater standards are generally lower than
the drinking water standards. The North Carolina Surface Water Quality Standards are also
chemical-specific ARARs for groundwater.
Final cleanup levels will also reflect the results of the BRA. The preambles to the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP) establish exposure to
the contaminant as a factor in setting ARARs, as indicated in the excerpts below:
• The likelihood of exposure actually occurring should be considered when
deciding the appropriate level of remediation. (55 FR 46 8710, EPA,
1990).
• Groundwater that is not an actual or potential source of drinking water
may not require remediation to a 104 to 10·6 level. (55 FR 46 8717,
EPA, 1990).
As noted above, the tentative groundwater cleanup objectives will be reviewed following receipt
of the BRA.
BROWN AND CALDWEU 2-7 F«uibililJ StlldJ Rq,011 • January 1995
Table 2-2 ARARs and Other Pertinent Criteria for the Chemicals Detected in the Groundwater at the Lot 86 Site
Concentration, mg/I
ARARs USEPA health advisories'
Parameter North Carolina standards Longer term Ix 104 Federal Federal I-Day IO-Day Lifetime cancer risk MCL' MCLG" Groundwatcrb Surface Drinking IO kg IO kg IO kg 70 kg 70 kg
water water" 70 kg
Volatiles:
Acetone _f -0.7 --------
Benzene 0.005 0 0.001 -0.005 0.2 0.2 ---0.1
Bromodichloromethane O.lg ~ --O.IOg 7 7 4 13 -0.06
Bromoform O.lg ~ 0.00019 -O.IOg 5 2 2 6 -0.4
2-Butanone (MEK) --0.17 --------
Carbon Disulfide -----------Carbon Tetrachloride 0.005 0 0.0003 -0.005 4 0.2 0.07 0.3 -0.03 Chlorobenzene 0.1 0.1 0.05 -0.1 ------Chloroform O.lg 0 0.00019 -0.1~ 4 4 0.1 0.4 -0.6
Dibromochloromethane O.lg 0.06" --0.1~ 7 7 2 8 0.06 -
I, 1-Dichloroethane --0.7 ---- ----1,2-Dichloroethane 0.005 0 0.00038 -0.005 0.7 0.7 0.7 2.6 -0.04
I, 1-Dichloroethene 0.007 0.007 0.007 -0.007 2 I I 4 0.007 -
1,2-Dichloroethene, total -----------
cis-1,2-Dichloroethene 0.07 0.07 0.07 -0.07 4 3 3 11 0.07 -
trans-1,2-Dichloroethene 0.1 -0.07 -0.1 20 2 2 6 0.1 -1,2-Dichloropropane 0.005 0 0.00056 ---0.9 ---0.05
Ethylbenzene 0.7 0.7 0.029 -0.7 30 3 I 3 0.7 -
2-Hexanone -----------
Methylene Chloride 0.005 0 0.005 -0.005 10 2 ---0.5
4-Methy 1-2-Pentanone -----------
I, 1,2,2-Tetrachlorocthane -----------
Tetrachloroethene 0.005 0 0.0007 -0.005 2 2 I 5 -0.07
Toluene I I 1.0 0.011 1 20 2 2 7 I -
I, I, 1-Trichloroethane 0.2 0.2 0.2 -0.20 100 40 40 100 0.2 -
1,1,2-Trichloroethane 0.005 0.003 --0.005 0.6 0.4 0.4 I 0.003 -Trichloroethene 0.005 0 0.0028 -0.005 -----0.3
Vinyl chloride 0.002 0 0.000015 -0.002 3 3 0.01 0.05 -0.0015
Xylenes, total 10 10 0.53 -10 40 40 40 100 10 -- - -----------------
-------------------
Table 2-2 ARARs and Other Pertinent Criteria for the Chemicals Detected in the Groundwater at the Lot 86 Site (continued)
Concentration, mg/I
ARARs USEPA health advisories'
Parameter North Carolina standards Longer tenn Ix 104
Federal Federal I-Day IO-Day Lifetime canCer risk MCL' MCLG' Groundwatcrb Surface Drinking IO kg IO kg IO kg 70 kg 70 kg 70 kg waterc water"
Semi-Volatiles:
Bis (2-Ethylhexyl) Phthalate 0.006 0 0.003 ---- - ---
Chrysene 0.0002' o; ----- - ---
Diethylphthalate --5.0 -- -- - -5 -
lsophorone -----15 15 15 15 0.1 4
Naphthalene -----0.5 0.5 0.4 I 0.02 -
Nitrobenzene --- -- -- - - --
Phenanthrene ------- - ---
Pyrene --- --- -- - - -
Pesticides:
b-BHC ------- - - - -
g-BHC (Lindane) 0.0002 0.0002 0.0002 0.00001 0.0002 1 I 0.03 0.1 0.0002 -
Chlordane, total 0.002 0 0.000027 0.000004 0.002 0.06 0.06 - - -0.003
p,p'-DDE ------ -- - --
p,p'-DDT ---0.000001 --- - - - -
Dieldrin ---0.000002 -0.0005 0.0005 0.0005 0.002 -0.0002
Metals:
Aluminum 0.05-0.2i ----- -- - - -
Arsenic 0.05 -0.05 0.050 0.05 -- - --0.002
Barium 2 2 2.0 -2 - - - -2 -
Beryllium 0.004 0.004 -0.0065 0.004 30 30 4 20 -0.0008
Cadmium 0.005 0.005 0.005 0.002 0.005 0.04 0.04 0.005 0.02 0.005 -
Calcium ------ -----
Chromium 0.1 0.1 0.05 0.050 0.1 1 1 0.2 0.8 0.1 -
Cobalt --- -
-- - -
---
Copper Loi-" 1.3 1.0 0.007' J.3k.m - - -
---
Iron O.Jl -0.3 1.0' 0.30 --- ---
Lead -k 0 O.Ql5 0.025 0.015k,m - -----
Magnesium ------ -----
Manganese, total o.osJ -0.05 -0.05 ------
Table 2-2 ARARs and Other Pertinent Criteria for the Chemicals Detected in the Groundwater at the Lot 86 Site (continued)
Concentration, mg/Q
ARARs USEPA health advisories'
Parameter North Carolina standards Longer term Ix 104 Federal Federal I-Day IO-Day Lifetime cancer risk MCL' MCLG' Groundwaterb Surface Drinking IO kg IO kg IO kg 70 kg 70 kg
watcrc water" -70 kg
Metals: (continued)
Mercury 0.002" 0.002" 0.0011 0.000012 0.002 ---0.002" 0.002" -Nickel 0.1 0.1 0.1 0.088 0.1 I I 0.5 1.7 0.1 -Potassium -----------
Sodium -----------
Vanadium -----------
Zinc 9 -2.1 0.0501 -6 6 3 12 2 -
Radioactive:
Carbon-14 -----------Gross alpha (adjusted) (pCi/L)0 15 0 15 15 15 ------
Tritium ---20,0QOP 20,000• ------
• USEPA, 40 CFR Parts 141, 142, 143; summarized in USEPA, Office of Drinking Water, Drinking Water Regulations and Health Advisories, Washington, D.C.,
May 1994.
' North Carolina Administrative Code (NCAC), Title 15A, Chapter 2, Subchapter 2L, Section .0202, Groundwater Quality, Standards for Class GA groundwater, October I 9, 1993.
' NCAC, Title 15A, Chapter 2, Subchapter 2B, Section .021 l(b)(3)(L), Fresh Surface Water Classifications and Standards, August I, 1991, Standards for Class C
(non-trout) surface waters.
" NCAC, Title 15A, Chapter !SC, Sections .1507, .1510, .151!, .1512, .1517, .1518, .1520, and .1521, Rules Governing Public Water Systems, Water Quality
Standards, November 5, 1992.
' USEPA, Office of Drinking Water, Drinking Water Regulations and Health Advisories, Washington, D.C., May 1994.
r "-" indicates standard not established.
g Standard applies to total trihalomethanes, not the single compound.
h Tentative MCLG.
' Proposed MCL and MCLG.
' Secondary MCL (unless noted, all others are primary MCLs).
k Copper and lead are regulated by treatment technique. 1 Source: as in (b) but Section .021 l(b)(4), (action levels which are considered numerical ambient water quality standards except for the purposes of NPDES
pennitting of point source discharges).
m Action level which is exceeded if more than 10 percent of tap water samples are greater than this value.
n Standard is for inorganic mercury.
0 Average annual gross alpha particle activity, excluding radon and uranium.
P Maximum average annual activity level for tritium.
q Average annual concentration (assumed to produce a total body dose of 4 mrem/yr).
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CHAPTER 2. IDENTIFICATION AND SCREENING OF TECHNOWGIES
As the North Carolina groundwater standards are more stringent than the federal MCLs,
they will be the groundwater cleanup objectives. The remediation of the groundwater will
consider all the contaminants of concern; however, groundwater remediation will focus on
chloroform, methylene chloride, benzene, and carbon tetrachloride as these chemicals were most
frequently detected in the groundwater. However, the groundwater standards for chloroform,
benzene, and carbon tetrachloride are below analytical method detection limits. Therefore, the
practical quantitation limit will be used as the cleanup goal. Thus, the groundwater cleanup
objectives for the Lot 86 site will be 5 micrograms per liter (µg/1) for chloroform, 5 µg/1 for
methylene chloride, 5 µg/1 for benzene, and 5 µg/1 for carbon tetrachloride.
CERCLA requires that site remedy performance be measured at appropriate locations in
the groundwater and soils. These "points of compliance" are the locations in the media of
concern where RAOs are to be measured for media compliance. Based on the language in the
NCP, the point of compliance for groundwater should be located in potential sources of drinking
water. The point of compliance for the groundwater at the Lot 86 site will be any well within
the Lot 86 site boundaries.
2.1.2.3 Location-Specific ARARs
Location-specific ARARs address site-specific aspects such as a critical
habitat upon which endangered or threatened species depend. Table 2-3 pre-
sents specific locations and associated prerequisites, requirements, and pertinent
regulations or law, and a determination of whether or not it is actually an
ARAR for the site.
The following conclusions may be drawn regarding location-specific ARARs. The subject
site is on largely undeveloped property near the NCSU stadium, where no specific critical
habitats, threatened or endangered species, or areas with historic value are known to be present.
The site is also not located in a floodplain, wellhead protection zone, or a unit of the National
Wildlife Range System. The nearest stream (Richland Creek) is located about 3,000 feet
downgradient of the site and no wetlands are expected to be impacted by the site.
2.1.2.4 Action-Specific ARARs
Action-specific ARARs address requirements associated with specific
remediation activities. The action prerequisites, requirements, pertinent regula-
tion or law, and determination of whether or not it is an ARAR for the site are
presented in Table 2-4. Action-specific ARARs will be considered later in this
chapter after the available remedial technologies have been screened.
BROWN A.NO CAUJWEU 2-11 Feasibility StudJ Report -)lllfWUJ 1995
Table 2-3 Location-Specific Applicable or Relevant and Appropriate Requirements
Location Prerequisite(s) Requirement(s) Citation Comments
Historic site owned or Property included in or eligible for Action to preserve historic prop-National Historic Preservation No historic properties exist on
controlled by federal the National Register of Historic erty; planning of action to mini-Act, Section 106 (16 USC 470 the Lot 86 site. agency Places. mizc harm to National Historic ~ ~; 36 CFR Part 800.
Landmarks.
Area where action Alteration of terrain that threatens Action to recover and preserve National Archaeological and Artifacts have not been found
may cause irreparable significant scientific. prehistoric, artifacts. Historical Preservation Act on the Lot 86 site.
harm, loss. or dcstruc-historic, or archaeological data. (16 USC Section 469); 36 CFR
lion of significant Part 65.
artifacts.
Within IOU-year Activity is RCRA hazardous waste Design, construct, operate, and 40 CFR 264.18(b). The Lot 86 site is not in a
noodplain treatment, storage, or disposal. maintain facility to avoid I 00-year noodplain.
washout.
Within floodplain Action occuning in a floodplain, Action to avoid adverse effects, Executive Order 11988, Protec-Not applicable for the Lot 86
i.e., lowlands, and relatively flat minimize potential harm, restore lion of Floodplains (40 CFR 6, site.
areas adjoining inland and coastal and preserve natural and bene• Appendix A), Fish and Wildlife
waters and other flood-prone areas. ficial values. Coordination Act (16 USC 661
~ ~; 40 CFR 6.302. ·-
Critical habitat upon Determination of presence of or Action to conserve endangered Endangered Species Act of 1973 No endangered or threatened
which endangered habitat of endangered species or species or threatened species, (16 USC 1531 ~ seq.): 50 CFR species or their habitat have
species or threatened threatened species. including consultation with the Part 200, 50 CFR Part 402, Fish been identified on or near the
species depends Department of the Interior. and Wildlife Coordination Act Lot 86 site.
(16 USC 661 ~~; 33 CFR
320-330.
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Table 2-3 Location-Specific Applicable or Relevant and Appropriate Requirements (continued)
Location Prerequisite(s) Requirement(s) Citation Comments
Within a wellhead Activity potentially impacting a The EPD will not issue any new Georgia Rules for Safe Drinking The Lot 86 site is not known
protection manage-drinking water supply permits for solid or industrial Waler 391-3-5-.40(8). to be localed in a wellhead
mcnt zone. waste landfills, land-disposal of protection zone. Remediation
hazardous waste, land application activities will be performed to
of wastewater or sludge, or prevent adverse impact to the
underground injection wells. groundwater.
All new TSD facilities permitted
to handle, treat, store or dispose
of hazardous waste or hazardous
materials must perform such
operations on an impenneable
pad having a spill and leak
collection system.
All new USTs must meet the
highest standards under the UST
Act.
All new wastewater treatment
basins must have an
impermeable synthetic liner.
\Vildcrncss area Site located in a unit of the Arca must be administered so as Wilderness Act ( 16 USC 668dd The Lot 86 site is not within a
National Wildlife Range System. to leave it unimpaired as wilder-£lgg) 50 CFR 27, 35.5. unit of the National Wildlife
ness and to preserve its wilder-Range System.
ness. The following are
prohibited in a wilderness area: . commercial enterprises . permanent roads, except as
necessary to administer the
area . structures or buildings . mechanized transport . motorized vehicles, equip--
mcnt, or boats . aircraft
Table 2-3 Location-Specific Applicable or Relevant and Appropriate Requirements (continued)
Location Prerequisite(s) Requirement(s) Citation Comments
Wild, scenic, or Any river, and the bordering or Actions to determine if project Wild and Scenic Rivers Act (16 No streams or rivers designated recreational rivers adjacent land, designated as "wild will affect the free-flowing char-USC 1271 g ~ Section 7(a)) as wild and scenic are known and scenic or recreational". acteristics, scenic, or natural 36 CFR 297.4, 40 CFR to be impacted by the Lot 86
values of a designated river, and 6.302(e). site.
action to avoid adverse effect.
Area affecting stream Diversion, channeling, or other Action to protect fish or wildlife. Fish and Wildlife Coordination No activities impacting a or river activity that mcxiifies a stream or Act (16 USC 661 !! .!£9); 40 stream or ri vcr arc planned at
river and affects fish or wildlife. CFR 6.302. the Lot 86 site.
Wetland Wetland as defined by Executive Action to minimize destruction, Executive Order 11990, Protec-No wetlands are known to
Order 11990, Section 7 and U.S. loss, degradation of wetlands. tion of Wetlands (40 CFR 6, potentially be impacted by the
Army Corps of Engineers rcgula-Action to prohibit discharge of Appendix A). Clean Water Act Lot 86 site. lions. dredged or fill material into Section 404, 40 CFR Part 230,
wetland without permit. Action 33 CFR 320-330.
to prevent impacted stonnwater
runoff from entering a creek or
wetland.
Hazardous waste site Potential worker exposure from Actions to limit worker exposure 29 CFR 1910.120. Remediation activities at the
construction, operations and main-to hazardous wastes or hazardous Lot 86 site must comply with
tenance, or other activities. substances, including training applicable health and safety
and monitoring. requirements.
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Table 2-4 Action-Specific Applicable or Relevant and Appropriate Requirements
Action Prerequisite(s) Requirement(s) Citation Comments
Container Storage RCRA hazardous waste held for a temJX)-Containers of hazardous waste must be: These requirements are applicable or rele-
(On-Sile) rary period in a container (any portahle vant and appropriate for contaminated soil,
device in which a material is stored, trans-. Maintained in good condition 40 CFR 264.171 groundwater, or treatment system waste
ported, disposed of, or handled) before
Compatible with hazardous waste to be 40 CFR 264.172 that may be containerized and stored
treatment, disposal, or storage elsewhere. . on-site prior to treatment or final disposal. stored Groundwater or soil containing a listed . Closed during storage (except to add or 40 CFR 264.173(a) waste will be managed as if it wer~ a
remove waslc) hazardous waste as long as it contains the
listed waste (per the RCRA "contained in" . Opened, handled, or stored in a manner to 40 CFR 264. I 73(b) policy).
prevenl rupture or leaking of the container
Inspect container storage areas weekly for leaks or 40 CFR 264.174
deterioration.
Place containers on sloped, crack-free base, and 40 CFR 264.175
protect from contact with accumulated liquid.
Provide containment system with a capacity of IO
percent of the volume of containers or the volume
of the largest container, whichever is greater.
Prevent run-on to the containment system or 40 CFR 264.175
pmvide a system to collect it.
Remove spilled or leaked waste in a timely manner 40 CFR 264.175
to prevent overflow of the containment system.
Keep containers of ignitable or reactive waste at 40 CFR 264.176
least 50 feet from the facility's property line.
Keep incompatible materials separate. Separate 40 CFR 264.177
incompatible materials stored near each other by a
dike or other barrier.
At closure, remove all hazardous waste and resi-40 CFR 264.178
dues from the containment system, nnd dccontami-
nate or remove all containers, liners, bases, and
soils.
Storage of land-banned wastes must be in accor-40 CFR 268.50
dance with 40 CFR 268. When such storage
occurs beyond 1 year, the owner/operator must be
able to prove that such storage is solely for the
purpose of accumulating sufficient quantities 10
allow for proper recovery, treaunent, or disposal.
Table 2-4 Action-Specific Applicable or Relevant and Appropriate Requirements (continued)
Action Prerequisi le( s) Requirement(s) Citation Comments
Groundwater Well Generation of nonwaste material (e.g., Any nonwaste material that contains a listed RCRA "contained in" Groundwater or soil generated at the Lot Installation, Devel-groundwater or soil) containing listed hazardous waste must be managed as if it were a policy, 58FR: 48092, 86 site will be tested for the presence of opmcnt, Testing. and hazardous waste. hazardous waste. September 14, 1993 hazardous waste characteristics and, if Sampling found to contain such, will be managed as
if it were a hazardous waste.
Groundwater Detection of hazardous constituents in the Groundwater monitoring at new or existing RCRA 40 CFR 264 (Subpart F) The need for groundwater monitoring at Monitoring groundwater. disposal units. the Lot 86 site will be evaluated.
Off-Site Shipment of Hazardous wastes generated on-site being All RCRA and DOT requirements for manifesting 40 CFR 262, 40 CFR The generator and transporter of off-site Hazardous Wasle shipped off-site. and shipping papers, marking, labeling, placarding, 263, 49 CFR I 71 through shipments of hazardous waste from the Lot
and special requirements based on type of carriage 179 86 site will meet the applicable RCRA and
(i.e., rail, aircraft, public highway, e1c.) must be DOT regulations.
met.
RCRA Treatment, Site or remedial activity qualifies as A regulated RCRA TSDF must submit an applica-40 CFR 270.10 through NPL sites are exempt from the TSDF Storage, and Disposal regulated RCRA TSDF. lion for a permit (including both Parts A and 8). 270.65 pennitting process; however, all Facility (TSDF) substantive requirements of the permitting Pennitting process will be met.
Treatment Treatment of hazardous wastes in units. Design and operating standards for hazardous waste 40 CFR 264 (Subpart X), The substantive portions of these
treatment units require new miscellaneous units lo 40 CFR 264.273, 40 CFR requirements will be applicable or relevant
satisfy environmental performance standards for 264.343-345, 40 CFR and appropriate to the construction,
protection of groundwater, surface water, and air 265 (Subpart P) operation, maintenance, and closure of any
quality, and hy limiting surface and subsurface miscellaneous treatment unit constructed al
migration. Miscellaneous units are treatment units the Lot 86 site for treatment and/or
that are not regulated elsewhere and include long-disposal of hazardous site wastes.
term retrievable storage, thermal treatment other
than incineration, open burning, open detonation,
chemical physical, and biological treatment units
using other than tanks, surface impoundments,
and/or land treaunent units. .
Treatment of Land Disposal Restricted Treatment of wastes subject to ban on land disposal 40 CFR 268 (Subpart D), The substantive portions of these require-(LOR) waste. must attain levels achievable by best demonstrated 40 CFR 268.10, 268.11, ments apply to the disposal of any Lot 86
available treatment technologies (BOAT) for each 268.12, 268.40 site wastes that are classified as restricted
hazardous consliluent in each listed waste. hazardous wastes.
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Table 2-4 Action-Specific Applicable or Relevant and Appropriate Requirements (continued)
Action Prerequisite(s) Requirement(s) Citation Comments
Treatment (c<mt'd.) BOAT standards are based on one or more of Lhc
following technologies: for wastewaters (I) steam
stripping; (2) biological treatment; or (3) carbon
adsorption (alone or in combination with (I) or (2);
and for all other wastes (4) incineration. Any
technology may be used, however, if it will achieve
lhe concentration levels specified.
Land-based remedial action. Regulations for land-based corrective actions of 40 CFR Suhpart S The substantive portions of these require-
RCRA facilities. (revised) menlS are relevant and appropriate to the
treatment prior to and disposal of any Lot
86 site wastes in concentrations suffi-
ciently similar 10 the regulated wastes.
The requirements specify levels of treat-
ment that must be attained prior to land
disposal.
Land Treatment RCRA hazardous waste being treated or Treatment program must ensure that hazardous 40 CFR 264.271 Requirements of regulations will be met as
placed into another unit. constituents are degraded, transformed, or applicable.
immobilized within the treatment zone.
Maximum depth of treatment zone must be no 40 CFR 264.271
more than 1.5 meters (5 feet) from the initial soil
surface and more than I meter (3 feet) above the
seasonal high water table.
Demonstrate that hazardous constituents in each 40 CFR 264.272
waste can be completely degraded, transfonned, or
immobilized in the treaunent zone.
Minimize runoff of hazardous constituents. 40 CFR 264.273
Maintain run-on/runoff control and management 40 CFR 264.273
system.
Land disposal of wastes requires treatment to meet 40 CFR 268
the LDRs for each chemical.
Table 2-4 Action-Specific Applicable or Relevant and Appropriate Requirements (continued)
Action Prerequisite(s) Requirement(s) Citation Comments
Incineration RCRA hazardous waste to be incinerated Analyze the waste feed. 40 CFR 264.341 Intent of regulations will be met as
on-site. applicable.
Dispose of all hazardous waste and residues, 40 CFR 264.351
including a,;h, scrubber water, and scrubber sludge.
No further requirements apply to incinerators that 40 CFR 264.340
only bum wastes that are listed as hazardous solely
by virtue of combination with other wastes, and if
the waste ana1ysis demonstrates that no Appendix
VII constituent is present that might reasonably be
expected to be present.
Air Emissions Emission of volatile organic compounds Control of VOC, particulate, and gaseous air Primary air contaminants expected are
Control During (VOCs), particulates, and gaseous air emissions. VOCs; VOC emissions from remediation
Remediation contaminants. equipment will be monitored and con-
trolled using carbon filters or other air
pollution control equipment proven to be
effective on voes.
Air Stripping ReRA hazardous waste. ReRA standards for control of emissions of 40 CFR Subparts AA and The standard requires voe reduction from
volatile organics llll "production accumulator vessels" and leak
detection and repair programs. Product
accumulator vessels include air strippers.
Underground lnjec-Injection of treated groundwater into the Federal underground injection control (UIC) 40 CFR 144 Treated groundwater from the Lot 86 site
lion of Wastes and subsurface. program prohibits: will he rcinjected only as part of a closed-
Treated Groundwater loop system and according to an approved . Inject.ion activities that allow movement of Non-Discharge permit.
contaminants into underground sources of
drinking water which may result in violations
of MCLs or adverse health effects.
. Construction of new Class IV wells, and
operation and maintenance of existing wells,
except for injection of treated groundwater
into the same formal.ion from which it was
withdrawn, as part of a CERCLA cleanup
or RCRA corrective action.
The state must have an approved UIC program per
the SDWA.
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Table 2-4 Action-Specific Applicable or Relevant and Appropriate Requirements (continued)
Action Prerequisite(s) Requirement(s) Citation Comments
Underground lnjcc-NC permits underground injection only in NC General S1a1utes 143-tion of Wastes and conjunction with closed loop groundwater 214.2(b) and 143-215.IA
Treated Groundwater remediation systems. A "Non-Discharge Permit" is
(cont'd.) required.
Discharge of Ernucnt Discharge of effluent to publicly owned Comply with the requirements of the federal 40 CFR 403 If effluent (i.e .• treated groundwater) is
treatment works (POTW). regulations and meet applicable city permitting discharged from the Lot 86 site to a
requirements. Meet pretreaunent standards set in POTW, federal and local requirements will
permit. be met.
Monitor the discharge to the PO1W in accordance 40 CFR 122.41(i)
with federal regulations and local permit.
Capping (see also RCRA hazardous waste placed at site after Placement of a cap over waste (e.g., closing a 40 CFR 264.228(a) The regulations will be met as applicable. "Closure wilh Waste the effective date of the requirements, or landfill, or closing a surface impoundment or waste (Surface Impoundments), in Place" for subsequent transferring hazardous waste pile as a landfill, or similar action) requires a cover 40 CFR 264.258(b)
associated into another unit. designed and constructed 10: (Waste Piles),
requirements) 40 CFR 264.3 IO(a)
Covering the waste with a cap for lhe . Provide long-tenn minimization of migration (Landfills)
purpose of leaving it behind after the of liquids through the capped area;
remedy is completed. . Function with minimum maintenance;
Capping under other conditions will not
trigger lhe requirements. . Promote drainage and minimize erosion or
abrasion of the cover;
. Accommodate settJing and subsidence so that
lhe cover's integrity is maintained; and
. Have a penncahility less lhan or equal to lhe
penneability of any bottom liner system or
nalural subsoils present.
Eliminate free liquids, stabilize wastes before 40 CFR 264.228(a)
capping (surface impoundments).
Restrict post-closure use of property as necessary to 40 CFR 264.l 17(c)
prevent damage to lhe cover.
Prevent run-on and runoff from damaging cover. 40 CFR 264.228(b)
40 CFR 264.3IO(b)
Protect and maintain surveyed benchmarks used to 40 CFR 264.3IO(b)
locate waste cells (landfills, waste piles).
Table 2-4 Action-Specific Applicable or Relevant and Appropriate Requirements (continued)
Action Prerequisite(s) Requirement(s) Citation Comments
Surface Water Discharge or treated groundwater to surface Fulfill NPDES pennit requirements. 40 CFR 125 The regulations will be met as applicable. Discharge water.
Closure with No Land-based unit containing RCRA General performance standard requires elimination 40 CFR 264.111 Intent of regulations will he met as appli-Post-Closure Care hazardous waste placed at site after the of need for further maintenance and control; elimi-cable. (e.g., Clean Closure) effective date of the requirements, or nation of post-closure escape of hazardous waste,
transferred into another unit. Not hazardous constituents, leachate, contaminated
applicable to material treated in situ, or runoff, or hazardous waste decomposition products. consOlidated within area of contaminaLion.
Designed for cleanup to health-based Disposal or decontamination of equipment, 40 CFR 264.111 standards and cleanup that will not require structures, and soils. 40 CFR 264.178 long-term management. 40 CFR 264. I 97
40 CFR 264.288(0)(1) May apply to surface impoundments, con-Removal or decontamination of all waste residues, and tainer or tank liners, hazardous waste contaminated containment system components (e.g., 40 CFR 264.258 residues, and to contaminated soil, includ-liners, dikes), contaminated subsoils, and structures ing soil disturhed in the course of drilling and equipment contaminated with waste and leach-
or excavation, and returned to land. ate. Management of these items as hazardous
waste.
Closure to protect human health and the environ-40 CFR 264.111
ment.
Closure with Waste Site with land disposal of RCRA hazardous Eliminate free liquids by removal or solidification. 40 CFR 264.22R(a)(2)(i) Intent of regulations will be met as appli-in Place waste placed at site after the effective date cable. of the requirements, or transferred to Stabilization of remaining waste and waste residues 40 CFR 264.228(a)(2)(ii)
another unit. Not applicable to material to support cover.
treated in situ, or consolidated within area
of contamination. Installalion of final cover to provide long-tenn 40 CFR 264.310
minimization of infiltration (see Capping).
30-year post--closure care and groundwater 40 CFR 264.117
monitoring. 40 CFR 264.3 IO
Closure of Land Closure of land treatment units. Maximize degradation, transformalion, or immobili· 40 CFR 264.280 Intent of regulation will be met as appli-Treatment Units zalion of hazardous constituents within the cable.
trealment zone, minimize runoff of constituents,
maintain run-on control system and runoff manage-
ment system, control wind dispersal of hazardous
waste, maintain unsaturated zone monitoring, estab-
lish vegetative cover, and establish background soil
values to determine consislency with permit values.
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Table 2-4 Action-Specific Applicable or Relevant and Appropriate Requirements (continued)
Action Prerequisite(s) Requirement(s) Citation Comments
Surface Water RCRA hazardous waste treated, stored, or Land Lreaunent units, landfills, waste piles: 40 CFR 264.273(c) and Intent of regulations will be met as
Control disposed after the effective date of the (d), 264.25l(c) and (d), applicable.
requirements. . Prevent run-on onto the treatment zone or active 264.30l(f) and (g)
zone during peak discharge from at least a
25-year storm.
. Collect and control runoff equal to at least the
water volume from a 24-hour, 25-year storm.
Storm Water Discharge of storm water from industrial Operations defined in the regulations which 40 CFR 122 Intent of regulations will be met as
Pcrmilling facilities and large construction sites discharge storm water from its facility must applicable.
(greater than 5 acres in area). perform sampling, submit a permit application, and
comply with all permit requirements, water quality
standards, and effluent limitations set by Best
Achievable Technology (BAD.
FS-2\7200TI-4.FS
CHAPTER 2. IDENTIFICATION AND SCREENING OF TECHNOLOGIES
2.2 ESTIMATION OF THE VOLUME AND CONCENTRATION OF CONTAMINATED
MEDIA
The volume, location, and composition of media impacted by the compounds of potential
concern are estimated in this section. These estimates are incorporated in the development,
screening, and analysis of remedial technologies and process options.
2.2.1 Groundwater
The approximate volume of groundwater requiring remediation is determined by the
groundwater RAOs established above. This volume will be established based on the results of
the shallow water-bearing unit assessment activities and the results of EPA's BRA. Although
the BRA may indicate that none of the shallow water-bearing unit's groundwater will require
remedial action other than continued water quality monitoring, for this FS the
groundwater volume that may need treatment is calculated to be 300,000
gallons. The estimated area of groundwater exceeding the RAOs is presented
on Figure 2-2.
2.2.2 Subsurface Soil
The extent of subsurface soil requiring remediation can be estimated from the criteria
established in the EPA BRA and the results of the RI. For this FS, the subsurface area is
estimated to be the contents of the trenches plus 2 feet horizontally and vertically from each
trench. This area of contamination exceeding RAOs is shown on Figure 2-3. ·
Based on this approach, the total volume of contaminated waste and soils to be
remediated is expected to approach 12,000 cubic yards.
2.3 GENERAL RESPONSE ACTIONS
General response actions describe actions that could satisfy the RAOs. General response
actions may include no action, institutional action, containment, removal, disposal, treatment, or
a combination of these. The relationship of the general response actions to the RA Os is shown
on Figure 2-1.
2.3.1 No Action
The no action alternative is retained throughout the feasibility study process as required
by 40 CFR 300.430(e)(6). This provides a comparative baseline against which other alternatives
can be evaluated. In the no action alternative, the contaminated soil and groundwater would be
left "as is" and would be monitored on a continuing basis. The monitoring effort would be
utilized to guide future actions. For example, if monitoring data indicated that the site's
environmental conditions were deteriorating, other remedial options could be implemented. On
the other hand, continuously improving environmental quality data would be utilized to demon-
strate the contaminant plume's gradual dissipation.'
BROWN AND CA.WWEU, 2-22 FeasibiliJy Study Rq,ort -}OIIUIUJ 1995
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MW3 MW35S ..
MW09 ..,_MW018
"'MW37
MW05A
MW36Sf +
W36D
r---\ ·--.
. ----
ESTIMATED EXTENT OF
GROUNDWATER CONTAMINATION
i r ,oo 200
' ' SCALE: 1"=--100'
LEGi=-N D
\
EXISTING FENCE -•-•-•-
EXISTING MONITORING WEll -+ MW05.:.
NEW SHALLOW MONITORING WELL 0 MW36S
NEW DEEP MONITORING WELL e MW360
\
\,..,..,...-✓/
Figure 2-2
NCSU LOT 86
GROUNDWATER AREA EXCEED'NG RAOs
Al!.._ ..i ~ IICIConsultonts
~.-v .. '32 ., +
MWJ3
~w,s +
MW35., MW35S
0,._
\.IW09
\IW05A
MW36S0 +
MW36D•
ESTIMATED EXTENT OF
SOIL CONTAMINATION --<-
50 0 100 200
SCALE: 1"=-100'
LEGEND
EXISTING FENCE -v -r --.--
EXISTING MONITORING WELL ♦ MW05A
NEW SHALLOW MONJTORING WELL 0 MW36$
NEW DEEP MONITORING WELL • MW36O
Figure 2-3
NCSU LOT 86
SOIL AREA EXCEEDING RAOs
ae.._.. ... _
IICIConsultcnts
V.WJ2
MW3.3 .
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CHAPTER 2. IDENTIFICATION AND SCREENING OF TECHNOWGIES
2.3.2 Institutional Action
Institutional action includes various access controls and deed restrictions. Although this
alternative provides no reduction of volume, mobility, or toxicity of the contaminants, it can
reduce or eliminate direct exposure pathways and the resultant potential risk to the public.
2.3.3 Containment
Another method of reducing the risk to the public is through containment, thus reducing
the mobility of the contaminants. To reduce mobility, the contaminated media must be isolated
from the primary transport mechanisms such as wind, surface water, groundwater, biological
means, and mechanical means. The isolation of the contaminated media may be accomplished
by the installation of surface and subsurface barriers to block or redirect any transport of media
away from the contaminants.
2.3.4 Removal/Disposal
The removal/disposal option consists of removing the contaminated medium by various
hydraulic, pneumatic, or mechanical means and directly disposing of this medium in an on-site
or off-site facility.
2.3.5 Containment/Treatment
The containment/treatment general response action would employ the same containment
technologies and related process options as the containment general response action and would
add a treatment action. The treatment would use one of several chemical and/or physical
treatment methods designed to reduce the toxicity, volume, or mobility of the contaminants
present.
2.3.6 Removalffreatment/Disposal
The last general response actions add a treatment technology to the removal/disposal
general response action combination previously cited such that the contaminated medium is
treated prior to disposal.
2.4 IDENTIFICATION AND INITIAL SCREENING OF TECHNOLOGY
TYPES AND PROCESS OPTIONS
The impacted media identified during the RI were the unsaturated subsurface soils and
groundwater. For each of these media, an initial list of remedial technologies and process options
are identified. These technologies are compiled from various EPA documents as well as other
applicable references. Only technologies that are potentially applicable to the Lot 86 site are
included. An initial screening for technical feasibility was performed on each of these
technologies and process options to eliminate those options not feasible based on site conditions,
BROWN A.ND CA.LDWEUJ 2-25 FffUibilb, Stud! Rq,or1 -/IJIUllU'J /995
CHAPTER 2. IDENTIFICATION AND SCREENING OF TECHNOWGIES
and to reduce the original number of possible options to a smaller group of viable options.
Information regarding site characterization, contaminant types, and contaminant concentrations
was used to eliminate options that were either not applicable or could not be implemented effec-
tively at the site.
2.4.1 Screening Criteria
The screening process involved two steps. The initial screening was performed to
eliminate process options and possibly entire technology types based on technical implement-
ability. This required reviewing the process options relative to their applicability to the identified
site conditions. The second screening step was performed to evaluate the remaining process
options based on institutional implementability, probable effectiveness and cost. The results of
this two-step screening process are intended to provide a basis for selection, if possible, of one
representative process option for each technology, thus simplifying the next stage, the detailed
analysis of alternatives.
2.4.2 Technology Descriptions and Evaluations
This section presents the initial screening of technology and process options for
groundwater and unsaturated soils, respectively. A glossary of process options is presented in
Appendix A.
2.4.2.1 Initial Screening: Groundwater Medium
The general response actions that are applicable for groundwater include
no action, institutional actions, containment, collection, treatment, and disposal
and selected combinations of these. These were described in Section 2.3. The
technologies and process options considered for the groundwater medium are
summarized on Figure 2-4. Options screened out in the first screening as not
appropriate or technically implementable are indicated by shading. A dis-
cussion of the rationale for retaining or eliminating these options is furnished in the following
paragraphs.
As required by EPA guidance, the no action response action will be retained for further
consideration.
An alternate water supply is not required and was eliminated from consideration because
uncontaminated drinking water is currently available from the City water supply or is being
withdrawn from the lower regional aquifer, located at depths on the order of 200 feet below
ground surface.
Access restrictions, including deed restrictions, use restrictions, and use of fences or signs,
were retained.
BROWN A.ND CA.WWELL 2-26 F11tUibililJ s,ua, Rq,or1. Ja,,uary 1995
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- -- - ---- - --11!!1 --- - ---=
General Response Action Technology Type Process Option
._ ___ .....;Nc:;o=Ac::cct"'lo::.:n.,_ ___ _,H._ ____ -'-N'-'/-'-A'--____ _.H._ _____ ...:.:N-'-/.:.;A:..... ___ __,
Water.Su
Institutional Action Deed Restrictions
Access Restrictions
Fences SI ns
Containment Hit•··rsub~urface·.i:10w.·.contro1.
Horizontal Extraction Wells
Extraction
Vertical Extraction Wells
Subsurface Drains Interceptor Trench
Collectlon / Dischar e
t 11rr,nnt11tratlorierii:l!Eiiil · ·ration \·.:n
Cit POTW
Off-Site Discher e
AnsurtacewaterDlschar
Assessment -
Technical Implementability
Retain the option.
Lower aquifer Is uncontaminated;
alternate supply not required.
Retain the option.
Retain the option.
Not applicable at depths required.
Unproven technology.
Not applicable at depths required.
Not applicable at depths required.
Site hydrogeology Is unfavorable.
Not applicable and horizontal barrier
already exists.
Retain the option.
Retain the option.
Retain the option.
Site hydrogeology Is unfavorable.
Site hydrogeology Is unfavorable and
large land area required not available.
Not applicable.
Retain the option.
Not appllcable because of contaminants.
Figure 2-4 Initial Screening of Technologies and Process Options for Groundwater
-General Response Action Technology Type Process Option
Containment/ Treatment
Bloreclamatlon
In Situ Treatment
Aeration
Assessment -
Technical Implementability
Not applicable at depths required.
Unproven technology.
Not applicable at depths required.
Not applicable at depths required.
Site hydrogeology Is unfavorable.
Not applicable and horizontal barrier
already exists.
Retain the option.
Unproven technology In In situ systems.
Retain the option .
.J Horizontal Extraction Wells I Retain the option.
,-----::E:-x-=--tr-a""'.ct::-lo_n _____ L.Jr~ .,-------------~
u_L __ ..!.V~ert=lc:!!a~I E:,x~t!!ra~c~tl~o!!n...!W~e!!!l!ols~_.JI Retain the option.
~,__ ___ S=ub,::Se.,U:,.rf:.:a:.:Cc:,:e.=D,,.r=al:,;nc:,:s ___ _,
Collection /Treatment/ Dlscharae I-
>-<L... __ ....!;P!!hi;v:s~l~ca~l...iTc!.re~a~t!!m!!:e~nc!.t __ ....Jt-
lnterceotor Trench I Retain the option. ~--~==~~==~---'
➔•----::-:---=:--:--:------,1 EPA Best Demonstrated Available
Air Strlnnlnq Technology (BDAn.
~~ ___ C_a_rb_o_n_A_d_s_o_r,_pt_lo_n ___ _,1 EPA BDAT .
.J\' ,, : Soiiian!Exiriiciloiii/' ''}(I Would add solvent constituents.
Not applicable to organic constituents.
+; Jk?d)''fReviirsaOsriioals)' l'fdH Not applicable to all contaminants
of concern .
.J Steam Strlnnlnq I Retain the option.
Figure 2-4 Initial Screening of Technologies and Process Options for Groundwater (continued)
- --- -
- -
General Response Action Technology Type Process Option
Chemical Treatment
Collection I Treatment I Discher e
Blolo lcal Treatment Blotreatment
''' ttlnflltratl6ri•and'Eva
Cit POTW
Off-Site Discher e
Surface Water Discharge
Potentially appllcable technology.
~F_,_·.·.·-==~--=~='.c..'c.''.c..''~i'""t=•H Technology or process option that has been screened out.
Assessment -
Technical Implementability
Not applicable to organic contaminants.
Not applicable to organic contaminants.
Retain the option.
Not applicable to organic contaminants.
Unproven technology.
Not applicable to organic contaminants.
Not effective treatment.
Not effective treatment.
Retain the option.
Site hydrogeology Is unfavorable.
Site hydrogeology Is unfavorable and
large land area required not available.
Not appllcable.
Retain the option.
Retain the option.
Figure 2-4 Initial Screening of Technologies and Process Options for Groundwater (continued)
CHAPTER 2. IDENTIFICATION AND SCREENING OF TECHNOWGIES
Regarding containment via subsurface flow control, excavation to install subsurface flow
controls to the depth required at this site is not technically feasible. Consequently, the following
process options were eliminated as not technically feasible: slurry wall, grout curtain, and sheet
pilings. A cryogenic barrier was eliminated because it is a commercially unproven technology.
Injection wells were eliminated as the site hydrogeology is not favorable for implementing this
type of flow control.
Controls on vertical subsurface flow, such as grout injection, are not required at this site
because there is an existing confining layer between the shallow impacted groundwater and the
lower water-bearing units. As these artificial horizontal barriers cannot be adequately installed
at the depths required, they would not provide any substantial benefits over the existing natural
barrier.
These subsurface flow controls (slurry wall, grout curtain, sheet pilings, cryogenic barrier,
injection wells, and grout injection) were also screened out for the containment/treatment general
response action.
Horizontal and vertical extraction wells, as well as an interceptor trench, were retained
as groundwater collection methods.
Subsurface injection was eliminated from consideration as a discharge option because the
low permeability soils are unfavorable. Infiltration and evaporation were eliminated from further
consideration as discharge options because large areas of land are required, and this land is not
available on-site. Furthermore, the low permeability and cohesive soils comprising the shallow
water-bearing unit make this option technically infeasible.
Off-site discharge to a publicly owned treatment works (POTW), in conjunction with both
the removal/disposal and removal/treatment/disposal general response actions, was retained
because of the presence of the local POTW sewer system. Surface water discharge in conjunc-
tion with the collection/discharge general response action was eliminated because of the volatile
organic compounds (VOCs) present in the impacted groundwater.
Again, these on-site discharge technologies (injection and infiltration/evaporation) were
screened out for the collection/treatment/discharge general response action while off-site
discharges to the local POTW and to surface water were retained.
In situ treatment process options for groundwater were considered. Bioreclarnation may
be feasible and was retained, although the soil permeability in the shallow saturated zone may
not be adequate for nutrient and oxygen transport. Chemical reaction was eliminated because this
technology has only been demonstrated on water in aboveground treatment systems, not in situ
systems. Aeration or in situ stripping has been demonstrated to a limited extent, and may be
feasible for aquifers having low permeabilities; thus, this process option was retained.
BROWN A.ND CA.WWELL 2-30 FmslbililJ Sludy Rq,on. J-UIJTJ 1995
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CHAPTER l. IDEN11FICATION AND SCREENING OF TECHNOWGIES
Three of the physical treatment process options were removed from consideration during
the initial screening because of their limited applicability and implementability. Solvent extrac-
tion was eliminated from further consideration because it is not effective in treating low concen-
trations of organics in water, and it could introduce solvent constituents into the groundwater
during treatment. Ion exchange is not applicable for organics. Reverse osmosis is principally
used to remove dissolved salts and has not been adequately proven to effectively remove the
organics of concern. Air stripping, carbon adsorption, and steam stripping are physical treatment
processes which may be applicable to the subject site.
The chemical treatment processes of neutralization, precipitation, reduction, and hydrolysis
were eliminated from further consideration because they do not effectively treat water contami-
nated with the identified VOCs. Photolysis is an innovative technology that may be applicable
to the contaminants, but it has not been commercially proven and thus was eliminated. Photoly-
sis may also partially degrade some chemicals, producing potentially hazardous by-products.
Oxidation was retained because it could be applicable to most of the contaminants.
Both of the thermal treatment techniques (wet air oxidation and incineration) were also
eliminated from consideration. Wet air oxidation and incineration are only practical for relatively
high concentrations of organic contaminants due to the energy required. Consequently, these
processes would not be feasible for the low concentrations of contaminants present at the site.
Ex situ biological treatment of groundwater was retained.
2.4.2.2 Initial Screening: Unsaturated Subsurface Soil Medium
The general response actions that are applicable for the unsaturated subsurface soil include
no action, institutional action, containment, removal, treatment, and disposal, and specified
combinations of these. These general response actions were described in Section 2.3.
The remedial technologies and process options considered for the
subsurface soil medium are summarized on Figure 2-5. Options not technically
applicable or appropriate were eliminated, as indicated by the shaded areas.
As required by EPA guidances, the no action response action has been
retained for further consideration. Access restrictions, including deed restrictions, use restrictions,
and use of fences and/or signs, were also retained.
Capping was retained for further consideration. Capping may be especially effective when
used in a situation where the contamination is shown to be restricted in subsurface mobility due
to the nature of the soils. Capping is also an EPA presumptive remedy for municipal landfills,
which have similarities to the Lot 86 site. Alternative materials for capping include clay, asphalt,
concrete, and synthetics.
Soil flushing was eliminated as an in situ treatment option because it would not be ef-
fective for clayey soils having low permeability, and because it is difficult to capture the flushing
BROWN A.ND CALDWELL 2-31 Feasibi/i/1 StudJ Report· Juuary 1995
General Response Action Technology Type
No Action H N/A H
lnstltutlonal Action Access Restrictions
Containment H Ca(!(!lng H
Cappln
Containment/ Treatment
In Situ Treatment
Process Option
N/A
Deed Restrictions
Fencln SI ns
Concrete/Clal/Slnthetlc
Concrete/Clay/Synthetic
Assessment -
Technical Implementability
Retain the option.
Retain the option.
Retain the option.
Retain the option.
Retain the option.
Site hydrogeology not favorable and
flushing agent difficult to capture.
Retain the option.
Site hydrogeology not favorable.
?MiOxldatlohI& .••• ,,"H un:~~=-en technology In low permeability
Not applicable to organic contaminants.
Not applicable to organics.
Commercially unproven.
Figure 2-5 Initial Screening of Technologies and ~rocess Options for Soil
------•-·--... - -... ---- -
General Response Action
1
Removal I Treatment I Dis osal
kW!
Technology Type
Excavation
Excavation
Chemical Treatment
•>+•nrstablllzatloil\
Thermal Treatment
Blotreatment
Off-Site Dis osal
On-Site Dis osal
Potentially applicable technology.
Process Option Assessment -
Technical Implementability
Conventional Excavation I Retain the option. ~-~=-======~-~
L.. ___ _,_R,_,C,,_R"'A"-'-'Fa,,,c,,_lle!!ltv:z... ___ ..JI Retain the option.
\hNoii'-RCRAl.aiic!IIII ?)YI No such facility exists.
Conventional Excavation
,,.,n.Superflclal•Flulds••Extractlonn•
•····nnso1veiit1Ac1c1·Extract10nnn
M ItElectrlcal.,.Separatlont·rn
Thermal Desor lion
Incineration
In-Place Re lacement
Retain the option.
Not applicable.
Not applicable.
Not applicable.
Not applicable.
Unproven technology.
Unproven technology.
Not applicable to organic contaminants.
Not applicable to organic contaminants.
Retain the option.
Retain the option.
Not effective treatment.
Not effective treatment.
Not applicable.
Retain the option.
Not applicable.
Retain the option.
Technology or process option that has been screened out.
Figure 2-5 Initial Screening of Technologies and Process Options for Soil {continued)
CHAPTER 2. IDENTIFICATION AND SCREENING OF TECHNOWGIES
agent. Soil vapor extraction was retained as it is an EPA presumptive remedy for CERCLA sites
with VOCs in unsaturated soils. In situ oxidation was eliminated because it has not been ade-
quately ~emonstrated for soil with low permeability. In situ vitrification was eliminated due to
its innovative status and its intended application for inorganic contaminants in soil. Inorganic
stabilization similarly was eliminated as not applicable to the organic contaminants at this site.
Radio frequency heating was eliminated because it is a commercially unproven technology.
Stearn/air stripping, in situ chemical treatment, and bioremediation were also eliminated because
they are best suited for highly permeable soils and could be cost-prohibitive at the Lot 86 site.
Excavation was retained as the method of removal for soils. On-site disposal via a non-
RCRA landfill was eliminated because a facility for this purpose does not exist, and due to the
uncertainty of the site's future use, constructing such a facility is not a practical option. Off-site
disposal at a RCRA landfill was retained.
Ex situ physical treatment technologies to be used in conjunction with excavation, includ-
ing acid extraction, soil washing, and electrical separation, were eliminated because they do not
effectively treat organic compounds.
Chemical treatment, including oxidation and photolysis, was screened out due to the lack
of adequate demonstration of these technologies for large-scale remediation of soils contaminated
with VOCs and other organics.
Both incineration and thermal desorption were retained as methods of thermal treatment
for soils.
FS-2\7200CH2.FS
BROWN A.ND CAWWEU 2-34 Feasibility Study Rq,or1 -J,u11uuy 1995
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CHAPTER 3.0
DEVELOPMENT AND SCREENING
OF REMEDIAL ALTERNATIVES
To develop alternative remedial actions, the technologies and process options which
passed the initial screening (Section 2.4) are now subjected to a secondary screening. The
process options which pass the secondary screening will then be assembled into various
remedial alternatives. The remedial alternative implemented. at the site will likely be a
combination of more than one process option. This section presents the secondary screening
of the applicable technologies and process options. It concludes with the summary of those
alternatives selected for detailed analysis in Chapter 4.0 of this FS Report.
3.1 SECONDARY SCREENING OF PROCESS OPTIONS
At the conclusion of Chapter 2.0, the technologies and process options
which passed the initial screening for the possible remedial alternatives were
summarized. The list of technologies and process options for the groundwater
and subsurface soil media was developed for this site to address the remedial
action objectives described in Section 2.1 of this report. The applicable
technologies and process options for the groundwater and unsaturated
subsurface soils which passed the initial screening are summarized on Figures 3-1 and 3-2,
respectively. These are now evaluated using the criteria of institutional implementability,
effectiveness and cost.
Where multiple process options for a given remedial technology remained after the
secondary screening, the best or most applicable options were chosen to be used in developing
remedial technology alternatives in Chapter 4.0. The process options that were selected to be
carried forward are considered representative of the associated remedial technology and were
intended to preserve a wide range of options. Reasons for choosing or eliminating certain
process options which passed the initial screening are described in the following sections.
3.1.1 Groundwater Medium
The no action general response was retained for development into an alternative as re-
quired by CERCLA. Deed restrictions were also retained because they can be implemented to
restrict groundwater use and the installation of wells until the concentrations meet the ARARs
established for the site.
The general response action of collection/discharge was eliminated because it could not
meet the preliminary RAOs, which require treatment of contaminated water.
BROWN AND CAWWEU 3-1 F«uibiliJJ Study Reporl -January /995
General Response Action Technology Type Process Option
._ ____ N'-'o=Ac:c.c:.tlo"'n"------'Hr-----.N.:,;;A.----7 __ -r------,NUI/ A;;-----7
Deed Restrictions
Institutional Action Access Restrictions
Fences, Signs
Horizontal Extraction Wells
Extraction
Vertical Extraction Wells
c=:::::ic~o!ij11~ec~t~Joiinu1~D~ls~c~h~a~riieL=~7H[-=-=-=-=-=-=Jsfuj§b~s~u.;..;rf~a~c~eJD_!!r_!B-'-l~ni!s.=:-=-=-=.Ji---"1. ____ 1n_te_r_c...:epc..t_or_T_r_e_nc_h ___ _.
Off-Site Discher e CltyPOTW
Bloreclamation
Containment/ Treatment In Situ Treatment
Aeration
Figure 3-1 Applicable Technologies and Process Options for Groundwater
---·---_, .• ------
----!111111 __ , __ -tJllll!t -, .. -General Response Action Technology Type Process Option
Horizontal Extraction Wells
Extraction
Vertical Extraction Wells
Subsurface Drains lnterce tor Trench
Air Strl In
Collection / Treatment I Discher e Ph slcal Treatment
Chemical Treatment Oxidation
Biological Treatment Biotreatment
Off-Site Discher e Cl POTW
Figure 3-1 Applicable Technologies and Process Options for Groundwater (continued)
General Response Action Technology Type Process Option
No Action N/A N/A
Deed Restrictions Institutional Action Access Restrictions
Fencln SI ns
[========£C~oiint~atij1niim;e~n~t=========.l----r----""""".c;:;-a::p::p:.1n::g:-----7-__ .... Concrete/Clay/Synthetic
Ca In Concrete/Cla /Synthetic
Containment/ Treatment
In Situ Treatment Soll Vapor Extraction
Excavation Conventional Excavation
Removal/ Disposal
Off-Site Dis osal RCRA Facill
Excavation Conventional Excavation
Thermal Desor lion
Thermal Treatment Removal /Treatment/ Dis osal Incineration
Off-Site Dis osal RCRA Faclllt
On-Site Dis osal In-Place Replacement
Figure 3-2 Applicable Technologies and Process Options for Soil
-~ -i--
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CHAPTER 3. DEVEWPMENT AND SCREENING OF REMEDIAL ALTERNATIVES
The containment/treatment response action was retained. This alternative includes the
in situ treatment of groundwater through a closed-loop biotreatment system.
Physical treatment using air or steam stripping are similar technologies. Steam stripping,
however, was eliminated beciluse it does not provide significant benefits over air stripping for
removal of the chemicals of potential concern and is typically more complex and costly.
Chemical oxidation was eliminated as a process option for groundwater as it offers no
advantage over carbon adsorption or air stripping, which were retained.
Biological treatment of the groundwater using a conventional aboveground activated
sludge reactor was eliminated due to its relative complexity in implementation, its moderate
effectiveness, and its moderately high costs. Chemical-specific ARARs also may not be
achieved using this option.
Discharge of treated groundwater to the local POTW was retained.
3.1.2 Subsurface Soil Medium
The no action general response action was retained for development into an alternative
as required by CERCLA. Deed restrictions on land use, construction, and use of fences and
signs were also retained.
For the containment/treatment general response action, capping utilizing concrete, along
with in situ soil vapor extraction, was retained for further consideration. Concrete is expected
to be more suitable for capping at the site than clay or synthetic materials, because it requires
less maintenance, is less likely to be damaged or punctured, is not prone to erosion, and is
cheaper and easier to install.
For the general response action of removal/disposal, excavation followed by disposal in
an off-site RCRA landfill was considered and then eliminated. Disposal without treatment
cannot be implemented because some of the soils are classified as RCRA-characteristic waste,
which is governed by the Land Ban Restrictions which require treatment prior to disposal.
Therefore, the removal/disposal action is not appropriate.
Both on-site incineration and thermal desorption of the excavated soils were retained for
consideration as the thermal treatment removal/treatment/disposal process options due to their
relative availability in the commercial market for treating large volumes of soil and ability to
remediate a wide variety of chemicals including volatile organics and some inorganics.
However, neither process is effective on metals and other inorganic compounds.
BROWN AND CALDWEU 3-5 FttUibililJ StudJ Rq,on. January 1995
CHAPTER 3. DEVEWPMENT AND SCREENING OF REMEDIAL ALTERNATIVES
3.2 DEVELOPMENT OF ALTERNATIVES
Summaries of the retained process options for groundwater and soil are
presented on Figures 3-3 and 3-4, respectively. As shown on the figures,
these options have been assembled into remedial alternatives.
FS-2\7200CH3.FS
BROWN AND CA.llJWEU 3-6 FeasibWIJ Study Rq,ort -Jtu1111UJ 1995
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_,, _____________ _ -~ -· .. -General Response
Action Technology Type Process Option
No Action 1---i NIA H~ ____ N/_A ___ __.
Institutional Action 1---i Access Restrictions HL __ D=ee::.:d:..R:.ce.:.s:.:t::.:rl.:.ct:;;lo:.:n.:::s:.__J
Implementability
Easily Implementable
Easily Implementable
Effectiveness in
Meeting RAOs
Possibly Effective in the
Long Term
Only Effective in the
Long Term
Cost
Low
Low
ContalnmenVTreatment 1---i In Situ Treatment H._ ___ B_l_o_tr-'-ea_t_m_e_n_t __ Implementable with
Dllllculty Somewhat Effective in the High
Long Term
I Collection/Trtmnl/Discharge r----
Extraction I Extraction System I Implementable with Somewhat Effective In the
' Dllllculty Long Term •
Combined
Air Stripping I Easily Implementable Effective on voes
H Physical Treatment
Carbon Adsorption I Easily Implementable Very Effective (BDAn
Combined
'--jrnoiiitrf.!-S~iij;te~D~is;;:chh;;;ar;;:g;;;e:--l--~,r--,cciiiiity,piiomTWW-11 Easily Implementable Very Effective
Figure 3-3 Alternatives Retained Following the Secondary Screening
of Technologies and Process Options for Groundwater
High
Moderate
High
Low
General Response
Action Technology Type Process Option Implementability Effectiveness in
Meeting RAOs
._ __ N_o_A_c_t_lo_n __ ~f---i._ ____ NI_A ___ ~I---I._ ____ N;.;;/_A ___ __, Easily Implementable Possibly Effective In the
Long Term
lnstltutlonal Action
Contalnmenvrreatment
Removal/Trtmnt/Dlsposal
Deed Restrictions
Access Restrictions
Fencing, Signs
Capping Concrete
In Situ Treatment Soll Va or Extraction
Excavation Conventional Excavation
Thermal Treatment Incineration
On-Site Disposal In-Place Replacement
Easily Implementable
Easily Implementable
Easily Implementable
Implementable with
Difficulty
Implementable with
Difficulty
Implementable with Difficulty
Implementable
Figure 3-4 Alternatives Retained Following the Secondary Screening
of Technologies and Process Options for Unsaturated Soils
Only Effective In the
Long Term
Only Effective In the
Long Term
Effective -EPA
rcresum~tlve remedy or mun clpal landfills
Somewhat Effective
Somewhat Effective
Effective
Somewhat Effective
Combined with
Other Technologies
Cost
Low
Low
Low
Moderate
Moderate
High
High
Low
---·---.. --- ---..
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CHAPTER 4.0
DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
4.1 INTRODUCTION
The assembled remedial action alternatives which have been selected
represent a range of distinct waste management strategies which address the
human health and environmental concerns associated with the site. The de-
scription of the alternatives and the analysis with respect to the nine criteria
presented on Figure 4-1 reflect the fundamental components of the various alter-
native hazardous waste management approaches being considered for this site.
The selected alternative will be further refined as necessary during the predesign phase.
The alternatives retained following the screening phase for each media are:
Table 4-1 Retained Alternatives
Alternative No. I For Subsurface Soil No action
Alternative No. 2 Institutional action
Alternative No. 3 Containment/capping
Alternative No. 4 Soil vapor extraction
Alternative No. 5 On-Site Incineration
Alternative No. I For Groundwater No action
Alternative No. 2 Institutional action
Alternative No. 3 Groundwater extraction and treatment
Alternative No. 4 Biotreatment
Figure 4-1 illustrates the relationship between the screening criteria and the nine evalua-
tion criteria. The nine criteria for the detailed analysis are grouped into three types: those
considered "threshold factors," which must be met for a remedial alternative to be selected;
"primary balancing factors," which are the primary evaluation criteria; and "modifying consider-
ations," which are not used here but are used by EPA to modify aspects of an alternative if
necessary.
In the following section, for each alternative the primary components are identified and
a brief technical description of these components is presented. After the technical description,
BROWN AND CAWWEU 4-1 Fmsibilily StudJ Report• January 1995
G:\5604\FSAG4-I.XLS
SCREENING CRITERIA
Effectiveness
Implementability
Cost
EVALUATION CRITERIA
Overall protection of human
health and the environment
Compliance with ARARS
Long•term effectiveness and
permanence
Reduction in toxicity, mobility,
and volume through treatment
Short.term effectiveness
► I Implementability ~---~----~--~
►I Cost -----------~
State Acceptance
Community Acceptance
]
]
ROLE OF CRITERIA DURING
REMEDY SELECTION
"Threshold" Factors
''Primary Balancing'' Factors
"Modifying11 Considerations
Figure 4-1 Relationship of Screening Criteria to the Nine Evaluation Criteria
--------------9/!W4
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
a discussion of the alternative with respect to threshold and pnmary balancing criteria 1s
presented. These criteria are discussed below.
The analysis of each alternative with respect to overall protection of human health and
the environment provides a summary evaluation of how the alternative reduces the risk from
potential exposure pathways through treatment, engineering or institutional action. This
evaluation also examines whether alternatives pose any unacceptable short-term or cross-media
impacts.
The federal and state requirements that are applicable or relevant and appropriate to each
alternative are identified. The ability of each alternative to meet all of its respective ARARs or
the need to justify a waiver is noted for each.
Long-term effectiveness and permanence are evaluated with respect to the magnitude of
residual risk and the adequacy and reliability of controls used to manage remaining waste
(untreated waste and treatment residuals) over the long-term. Alternatives that afford the highest
degrees of long-term effectiveness and permanence are those that leave little or no waste
remaining at the site such that long-term maintenance and monitoring are unnecessary and
reliance on institutional action is minimized.
The discussion of the reduction of contaminant toxicity, mobility or volume through
treatment addresses the anticipated performance of the remedy's treatment technologies. This
evaluation relates to the statutory preference for selecting a remedial action that employs
treatment to reduce the toxicity, mobility or volume of hazardous substances. Aspects of this
criterion include the amount of waste treated or destroyed, the reduction in toxicity, mobility or
volume, the irreversibility of the treatment process, and the type and quantity of residuals
resulting from any treatment process.
Evaluation of alternatives with respect to short-term effectiveness takes into account
protection of workers and the community during the remedial action, environmental impacts from
implementing the action, and the time required to achieve cleanup goals.
The analysis of implementability deals with the technical and administrative feasibility
of implementing the alternative as well as the availability of necessary goods and services. This
criterion includes such items as: the ability to construct and operate components of the alterna-
tives; the ability to obtain services, capacities, equipment and specialists; the ability to monitor
the performance and effectiveness of technologies; and the ability to obtain necessary approvals
from other agencies.
The cost estimates presented in this report are based on information derived from a variety
of sources including quotes from suppliers in the area of the site, generic unit costs, vendor
information, conventional cost estimating guides, and prior experience. The feasibility study level
cost estimates are anticipated to be within 30 percent of actual costs. These costs have been
prepared for guidance in project evaluation and implementation from the information available
BROWN AND CAWWEU 4-3 Fnuibilily Study Report• January 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
at the time of the estimate. The actual costs of the project will depend on final project scope,
true labor and material costs, actual site conditions, competitive market conditions, the imple-
mentation schedule, and other variable factors. A significant uncertainty that would affect the
cost is the actual volumes of contaminated soil and groundwater which require remedial action.
Most of these uncertainties would affect the costs presented for every alternative.
Capital costs include those expenditures required to implement a remedial action. Both
direct and indirect costs are considered in the development of capital cost estimates. Direct costs
include construction costs or expenditures for equipment, labor and materials required to imple-
ment a remedial action. Indirect costs include those associated with engineering, pennitting (as
required), construction management, and other services necessary to carry out a remedial action.
Annual O&M costs, which include operation labor, maintenance materials and labor,
energy, and purchased services, have also been projected. The estimates include those O&M
costs that may be incurred even after the initial remedial activity is complete. The present worth
O&M costs have been determined for 30 years at an 8 percent discount rate. The discount rate
was chosen to include a degree of uncertainty in cost estimating at this preliminary stage.
State and community acceptance issues are not part of this analysis as they are assessed
by EPA during the RI/FS and ROD review process.
4.2 INDIVIDUAL ANALYSIS OF REMEDIAL ALTERNATIVES FOR
SUBSURFACE SOILS
4.2.1 Alternative No. 1-No Action
The no action alternative for soils provides a baseline for comparing other alternatives.
Because no remedial activities would be implemented, long-term human health and environmental
risks for the site would initially be the same as those that currently exist. However, the sub-
surface soil contaminants, which could pose a threat to groundwater, are susceptible to natural
biodegradation, and thus long-term attenuation will occur even under the no action alternative.
Criteria Assessment
Overall Protection of Human Health and the Environment. Alternative No. I, which
assumes no action for subsurface soil, would not change the current or hypothetical future levels
of risk from chemicals migrating to the groundwater.
Compliance with ARARs. There are no ARARs for soils contaminated with VOCs. The
cleanup goal for subsurface soils are the RAOs presented in Chapter 2 of this FS. Natural
attenuation would slowly reduce contaminant levels to the RA Os, but not within the 30-year time
frame required.
BROWN AND CAWWEU 4-4 FetaibililJ SludJ Rq,ort. }anll41'11995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Long-Term Effectiveness and Permanence. Under the no action remedy, reliance for
long-term effectiveness and permanence rests on the efficacy of natural attenuation in subsurface
soils.
Reduction in Toxicity, Mobility, and Volume Through Treatment. Natural attenuation
can be relied upon to help subsurface soil concentrations decline through treatment, but this
would take many years to achieve. Under this alternative, concentrations at the site would be
assessed by periodic soil sampling.
Short-Term Effectiveness. The no action alternative does not change the estimated risks
for this site. However, it also poses no risk to the community or the environment from the
removal, treatment, or disposal of soils.
Implementability. As no action is proposed, this alternative is readily implemented.
Cost. No capital costs would be required for this alternative since no remedial action will
be implemented. It would be necessary to sample these soils annual! y and prepare a public
health assessment every 5 years. O&M costs consist of collecting ten soil samples annually plus
laboratory analysis for T ALffCL compounds and reporting. The present worth cost of the no
action alternative is about $475,000.
Capital Cost
No action
Annual Cost
Collecting ten soil samples, laboratory analyses,
and reporting each year
Present Worth Cost
N = 30 years,
Sampling, analysis, and reporting
Contingency (20 percent)
Total annual cost
I = 8 percent annual
Cost, dollars
0
35,000
7,000
42,000
PW Capital cost + (I • 0.08)30-I (Annual cost) = 0.08 (I• 0.08)30
PW = 0 + 11.26 (42,000)
= approximately $475,000
BROWN A.ND CA.WWEU 4-5 FemibilitJ Study Rq,on • JanuarJ 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
4.2.2 Alternative No. 2-lnstitutional Action
This alternative is similar to Alternative No. 1 except that deed restrictions plus physical
barriers would be used to restrict access to the site. Deed restrictions would include zoning
ordinances that prohibit construction on, or use of, the site during the time that the soil remains
contaminated above cleanup goals. Physical barriers would include fencing, signs, etc. to prevent
access to the site.
Criteria Assessment
Overall Protection of Human Health and the Environment. Alternative No. 2, institu-
tional action, would provide protection to human health and the environment by controlling
exposure to contaminated soils through limiting future land use, preventing site excavation/
construction, and restricting site access. This alternative would rely on the static nature of the
landfill and the present dormant nature of the site, for protection.
Compliance with ARARs. There are no ARARs for soils contaminated with VOCs. The
cleanup goal for subsurface soils are the RAOs presented in Chapter 2 of this FS. As with the
no action alternative, contaminant levels would gradually decline through natural attenuation.
Long-Term Effectiveness and Permanence. Under the institutional action remedy,
reliance for long-term effectiveness and permanence rests on the efficacy of the natural
attenuation and immobility described above to achieve the RAOs. However, this alternative also
would have the added benefit of preventing access and restricting future use, thus limiting
potential exposures until the RAOs are met.
Reduction in Toxicity. Mobility, and Volume Through Treatment. Natural attenuation
can be relied upon to help subsurface soil concentrations decline, but this would take many years
to achieve. No active treatment would be used to reduce the toxicity, mobility, or volume of the
soil contaminants. Under this alternative, concentrations at the site would be assessed by periodic
soil sampling.
Short-Term Effectiveness. The short-term effectiveness of the institutional action alter-
native is better than no action because the potential exposures are limited due to restricted access
and future land use. Also, there is no exposure due to the removal, treatment, or disposal of
soils. However, the RA Os presented in Chapter 2 of this FS would not be met in the short term.
Implementability. The institutional action alternative is easily implemented. The admin-
istrative and possible legal actions which are required to institute deed restrictions are typically
straightforward, particularly since the site is owned by the PRP.
Cost. Securing of the site and deed restriction costs have been included in the capital
costs. It would also be necessary to sample the soils annually and prepare a public health
assessment every 5 years, as for Alternative No. I. Verification of controls, however, would also
be required. The present worth cost of this alternative is about $700,000.
BROWN AND CAWWEU 4-6 FetUibililJ SludJ Rtpart -Ja11uar, 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Capita! Cost
Remove existing fence
Install 6-foot chain link fence
Grade site and seed
1,200 If @ $3/ft
1,500 If@ $15/ft
Lump sum
Deed documentation and agreements
Contingency
Total capital cost
Annual Cost
Soil sampling and reporting (as Alternative No. I)
Verification of controls
Total annual cost
Present Worth Cost
PW =
=
59,100 + I 1.26 (57,000)
approximately $700,000
4.2.3 Alternative No. 3-Containment/Capping
Cost, dollars
3,600
22,500
3,000
20,000
10,000
59,100
42,000
15,000
57,000
Alternative 3, containment by capping, would involve the installation of an impervious
layer over the area of contaminated soil ( considered to be an area of approximately 40,000 square
feet) and development of a stormwater management system to route stormwater off the cap in
an acceptable manner.
In view of the nature of the site soils, soil cement would be the most appropriate material
with which to construct the cap. Soil cement capping would be carried out by an in situ method,
whereby a conditioner and cement are mixed with the top 12 inches of soil. With the addition
of water and further mixing and rolling, a firm, dense impermeable cap would be produced.
This alternative would also include site preparation work and fencing.
Criteria Assessment
Overall Protection of Human Health and the Environment. Capping is the pre-
sumptive remedy for CERCLA Municipal Landfill Sites (EPA Directives 9355.0-47FS and 49FS
September 1993) (Appendix B). A presumptive remedy is the preferred technology for
remediation and is expected to be used at all appropriate landfill sites. Although the Lot 86 site
is not a municipal landfill, it has many similarities.
BROWN AND CALDWELL 4-7 FeasibwlJ StudJ Report -Januar, 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Alternative No. 3, containment by capping, would provide good overall protection of
human health and the environment. It would minimize any possibility of human contact with
contaminated soils. Also, it would minimize the migration of contaminants to the groundwater
by preventing stormwater infiltrating through the trenches, solubilizing the contaminants. The
NCP recognizes the impracticability of treatment of landfills NCP Sec. 300.430(a)(iii)(A) and the
advantages of containment/capping (Appendix C pages 47 and 50).
Compliance with ARARs. There are no ARARs for soils contaminated with VOCs.
Because this alternative does not provide direct remediation of the soils, it would not initially
meet the RAOs. However, it would rely on the long-term attenuation to slowly reduce the
concentration of contaminants to meet the RAOs.
Long-Tenn Effectiveness and Permanence. This alternative would have long-term
effectiveness due to the reduction of chemicals leaching into the groundwater and in the risk of
direct exposure to soils. Also, some natural biodegradation would continue at the site.
Reduction in Toxicity, Mobility, and Volume Through Treatment. This alternative
would not produce a reduction in the toxicity and volume of the contaminants by treatment. It
would rely on long-term attenuation as described.
Regarding mobility, the capping would eliminate moisture passing through the landfill
from rainfall; so this alternative would restrict and reduce the mobility of the contaminants very
effectively.
Short-Tenn Effectiveness. Because this alternative would not involve disturbing the
contents of the landfill and uses standard construction procedures on the surface only, it would
be very effective in the short term because there would be no exposure of humans or the environ-
ment to the chemicals. There is virtually no increased health risk in the short-term operations.
Leachate will be reduced in the short term. However, this option will not achieve the site RAOs
in the short term.
Implementability. A cap could easily be constructed over the area of contamination
utilizing standard construction methods. The reliability of the cap could be assured by proper
design and construction procedures. The alternative should address exposure concerns due to
dust emissions and other direct exposure to workers by proper planning and control of the
capping operation. It would take 6 months to complete.
Cost. Based on an estimated cap volume of 1,500 cubic yards, the total cost would
include the initial construction cost of the capping and ancillary work of $550,000 with routine
evaluations including cap inspections, repairs, patching, drainage modifications, etc. The annual
maintenance cost is estimated at $57,000. The present worth of this alternative is then $550,000
+ 11.26 x $57,000 = $1,191,280 or about $1,200,000.
BROWN AND CALDWEU 4-8 FeasibiliJJ StudJ Report -}IJIUIIJl1 l995
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D
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
4.2.4 Alternative No. 4-Soil Vapor Extraction
Soil vapor extraction (SVE) is the presumptive remedy for in situ treatment for CERCLA
sites with VOCs in soils (EPA Directive 9355.0-48FS September 1993) (Appendix D). The
presumptive remedy is the preferred technology for remediation and is expected to be used at all
appropriate sites. Lot 86 qualifies as an appropriate site per the EPA Directive in Appendix D.
SVE is described in this appendix as well as in Appendix E, an excerpt from an EPA Workshop
Summary (EPA/600/R-92/030) and a paper presented by Brown and Caldwell, "Operating
Principles and Case Histories of SVE Systems."
In this case it is proposed to remediate that portion of the soils in the unsaturated zone
vertically between the landfill trenches and the groundwater table, using SVE. This technology
involves creating a movement of air through the soil via a series of injection wells in this region,
which would then vaporize the VOCs and also would assist any metals present to be oxidized.
The vaporized gas would then be removed from the ground by a series of vacuum wells. The
effectiveness of the system will be dependent on the soil permeability allowing air to move
through the soils. The high clay and silt content of the soils may restrict the ability of SVE to
remediate this site.
The precise layout and extent of the system would have to be determined by further inves-
tigation and a pilot test system. Field tests used to determine site conditions for SVE system
design are described in Appendix F. In general, the system would consist of a number of air
injection wells laid out in a grid pattern which is overlaid by vacuum extraction wells also
arranged in a grid pattern. The grid would cover the area containing VOCs which at the Lot 86
site is assumed to be the landfill shadow. Each of the two types of wells would be connected
to a separate central main air pipe and thereby to air injection and vacuum extraction pumps,
respectively. The extracted vapor would be passed through activated carbon canisters, to capture
the VOCs, prior to release to the atmosphere.
Criteria Assessment
Overall Protection of Human Health and the Environment. Providing that the soil
investigation and pilot testing yield results would justify SVE, the technology would reduce the
levels of VOCs and metals in the soil beneath the landfill to meet cleanup criteria. This would
then also eliminate the present source of groundwater contamination, thereby providing overall
protection to human health and the environment.
Compliance with ARARs. This alternative may comply with the RAOs including
location-specific and action-specific ARARs. As the soil was determined in the RI to consist of
mostly silts and clays, there is some uncertainty that ARARs can be achieved within the 30-year
time frame.
Long-Term Effectiveness and Permanence. Assuming that site soils are sufficiently
permeable, this alternative would permanently reduce the contaminant levels in the soils.
BROWN AND CALDWEU 4-9 Fea.,ibililJ StudJ Rq,on. Jattuar, f995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
However, it would also be necessary to monitor semiannually after cleanup levels are achieved
in order to check that further contamination is not spreading downwards from the remaining
chemicals in the landfill trenches.
Reduction in Toxicity, Mobility, and Volume Through Treatment. SVE would reduce
the toxicity, mobility, and volume of the contaminants because it would remove them from the
unsaturated soil sufficiently to meet cleanup goals.
Short-Term Effectiveness. The risks to workers during the testing, installation, and
operation of this system would be similar to those that were encountered during the RI. They
can easily be controlled by use of normal health and safety practices. Because of the lower
permeable soils, SVE is expected to operate longer than other similar systems. It is estimated
that SVE would operate for about 5 years to achieve cleanup goals.
Implementability. Implementability would be totally dependent on the results of the
specific SVE site investigation and pilot testing program. Providing that this yields encouraging
results, the system could be implemented using standard equipment. The time period for design,
testing, and implementation to start-up would be I year.
Cost. At this stage it is appropriate to estimate a minimal scope and assume that the site
conditions would readily support the SVE approach utilizing standard technology, supplies, and
equipment. Based on this approach, the estimated cost for Alternative 4 is about $2.3 million.
Capital Cost
Investigation and pilot test
Well installation ( assuming 20 wells)
SVE equipment and installation
Engineering
Contingency
Annual Cost (for 5 years) (N = 5 years, I = 8 percent annual)
Annual cost equipment and operation
Carbon replacement allowance
Contingency
Annual Cost (for 30 years)
Monitoring
BRO~ AND CALDWEU 4-10
Cost. dollars
60,000
. 60,000
200,000
80,000
100,000
500,000
100,000
100,000
50,000
250,000
75,000
Fea1ibilily Study Report· JanUIUJ 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Present Worth Cost
PW = 500,000 + (I+ 0.08)'-I
0.08 (I+ 0.08)5 (250,000) + 11.26 (75,000)
= approximately $2.3 million
4.2.5 Alternative No. 5-0n-Site Incineration
Alternative No. 5, on-site incineration, initially involves excavation and stockpiling of the
contaminated material. The excavated material would then be conditioned prior to being incin-
erated on-site. Properly prepared material when incinerated results in a clean ash residue. The
excavated area would be backfilled with the ash supplemented with clean imported soil. The
incineration would take place within a mobile incinerator which would be brought to the site and
set up, together with a soil conditioning plant, to receive the contaminated soil. It would be
operated as a continuous process with a throughput of about 50 cubic yards per day. The inciner-
ation would take about 1 year to complete, not including the test burn, mobilization, and start-up.
Incineration is one of the presumptive remedies for CERCLA sites with VOCs in soils (Appendix
D).
Overall Protection of Human Health and the Environment. Alternative No. 5, inciner-
ation, provides overall protection to human health and the environment through the destruction
of the contaminants. It would provide treatment for all of the soils required to achieve RAOs
in subsurface soils. The treated materials would then be returned to the ground in a closed cycle
which would have further benefit in that no contaminated material would leave the site.
Compliance with ARARs. Based on documentation from previous successful incinera-
tion of similar contaminants with similar concentrations, this technology would meet the RAOs
presented in Chapter 2 for subsurface soils.
Long-Term Effectiveness and Permanence. This technology would be effective because
it would destroy and/or remove all contamination to achieve the RAOs in the soils. Contami-
nants would be collected and disposed of off-site. The treated material (ash), along with some
imported clean backfill, would be used as backfill.
Reduction in Toxicity, Mobility, and Volume Through Treatment. The technology
would remove toxicity, eliminate mobility, and reduce the volume of contaminated materials by
treatment.
Short-Term Effectiveness. Achievement of short-term effectiveness would require
special construction and operational procedures and controls to ensure protection of human health
and the environment. Exposure from dust, off-gases, and direct exposure would have to be moni-
tored and controlled. The highest potential for exposure to workers and the community would
be during the excavation of the trench materials. Also, noise and other community impacts
BROWN AND CA.WWEU 4-11 FeasibililJ StudJ Rqort -Janwuy 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
should be strictly controlled. This technology has been used at contaminated sites elsewhere.
It has proved to be reliable and risk free, providing it is properly planned and supervised.
Implementability. As stated, this technology has been used at similar sites and is imple-
mentable. However, because it is a complicated process, with specialized equipment and con-
trols, the system would be more difficult to implement than other soil alternatives. Also, some
preprocessing of the materials would be required prior to the incineration because of the diversity
of the materials to ensure all contaminated materials are treated. However, care must be taken
during preprocessing because some of these chemicals react with other chemicals present.
Incineration also requires a large area for implementation. The footprint on-site is
expected to be approximately 200 feet by 200 feet, not including the area for soil staging. Also,
there are a ·number of perceived health risks associated with incineration which are generally
centered around the operation of the equipment and air emissions. Although emissions can be
effectively controlled by several technologies, public perception is that they cannot. In order to
operate an incineration plant, an air permit and other permits would be required, which have
public notice requirements. These often lead to a powerful citizens' lobby in opposition.
Cost. There are a number of contractors prepared to carry out this work and costs are
heavily dependent on availability of the specialized incineration equipment.
Because of the nature of the material on this site, preconditioning of the material would
be required prior to incineration. This would also reduce throughput and slow down incineration
operation. Both of these factors combine to increase the cost above what is generally quoted for
this type of work. Contractors' estimates for incineration of this material, including preprocess-
ing and personal protection, would be $450 to $600 per ton. This does not include treatability
testing, planning and design, and sampling, estimated at $500,000. It is estimated that the total
cost, including backfilling, would be about $ I 0.8 million on a present worth basis.
4.2.6 Alternative No. 6-Low Temperature Thermal Desorption
On-site low temperature thermal desorption is a relatively recent technology which has
gained acceptance as an alternative to incineration. Mobile thermal treatment units have been
shown to remove a variety of contaminants from soil.
The process consists of a heated chamber with temperatures of 700 to 900 degrees
Fahrenheit. Contaminated soils are excavated, preconditioned, broken up, and then fed into the
chamber in a continuous operation. Contaminants are driven off the soil by the heat and are
captured in the next stage bag house, GAC, or other equivalent system. The treated soil is placed
back in the ground and the captured contaminants are sent off-site for disposal to an authorized
incinerator or for regeneration.
BROWN AND CAWWEU 4-12 Fauibilil1 Study Rq,or1 -January 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Criteria Assessment
Overall Protection of Human Health and the Environment. Alternative No. 6, low
temperature thermal desorption, provides overall protection to human health and the environment
through the destruction of the contaminants. It provides treatment for all of the soils required
to achieve the RAOs in subsurface soils. The treated soils are then returned to the ground in a
closed cycle which has further benefit in that nothing leaves the site.
Compliance with ARARs. This technology will meet all ARARs presented in Chapter
2 for subsurface soils. This is based on documentation from previous successful sites with
similar contaminants and concentrations.
Long-Term Effectiveness and Permanence. This technology is effective because it
destroys and/or removes all contamination from soil to achieve the RAOs. Contaminants are
collected on GAC or in the baghouse and disposed of off-site. The treated soil (ash) will be used
as back.fill, along with some imported clean backfill.
Reduction in Toxicity, Mobility, and Volume Through Treatment. The technology
likewise removes toxicity, eliminates mobility, and reduces the volume of contaminated soils by
treatment to an acceptable level.
Short-Term Effectiveness. Achievement of short-term effectiveness will require special
construction, and operational procedures and controls to ensure protection of human health and
the environment. Exposure from dust, off-gases, and direct exposure will have to be monitored
and controlled. Also, noise and other community impacts should be limited. This technology
has been used at contaminated sites elsewhere. It has proved to be reliable and risk free,
providing it is properly planned and supervised.
Implementability. As stated, this technology has been used at a similar site and is imple-
mentable. Because it is a complicated process, with specialized equipment and controls, the
system will be more difficult to implement than other soil alternatives. Because of the small site
area, and footprint needed to set up this unit, staging of this unit will encroach on neighboring
property. Also, because of the plastic clays and silts, some significant preprocessing of the soils
will be required prior to the thermal treatment because of the plastic clays and silts to ensure all
contaminated soils are treated.
Cost. Costs for the L TTD alternative were obtained from subcontractor estimates and
averaged $200 per ton. However, soil pretreatment costs are estimated at $50 to $100 per ton.
The costs for planning and design fees, treatability testing (if required), as well as soil sampling
and analysis, and backfilling are estimated at $800,000 for a total capital cost and present worth
of $5,750,000.
4.3 COMPARATIVE ANALYSIS OF SOIL REMEDIAL ALTERNATIVES
A detailed comparative analysis was performed on the five soil remedial alternatives
developed during the FS using the seven evaluation criteria detailed at the start of this chapter.
BROWN AND CAUJWEU 4-13 FnuibilitJ Study Rq,on -January 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
The advantages and disadvantages of each alternative were compared to identify the alternative
with the best balance among these seven criteria. As previously indicated, according to the NCP,
the first two criteria are labeled "threshold criteria," relating to statutory requirements that each
alternative must satisfy in order to be eligible for selection. The next five criteria are labeled
"primary balancing criteria," which are technical criteria upon which the detailed analysis is
primarily based. The final two criteria not addressed here are known as "modifying criteria,"
assessing the public's and state agency's acceptance of the alternative. Based on these final two
criteria, EPA may modify aspects of the specific alternative.
A summary of the relative performance of each alternative with respect to the evaluation
criteria is provided in the following subsections. A comparison is made between the alternatives
for achievement of each criterion.
4.3.1 Scoring Procedure
As an aid to the comparative analyses, all the alternatives were evaluated by using a
numerical scoring and ranking system for each of the first seven criteria. The scoring· is from
1 to 10 with a I being the worst performance in meeting the criteria and 10 being the best per-
formance. Each alternative is scored for each of the seven criteria with cumulative totals
summarized at the end. These total scores are an arithmetic sum of the individual values and do
not reflect differences in criteria importance. As such, the scoring is presented merely to assist
the reader in comparing alternatives and is not intended to indicate preference or be used as the
sole selection methodology. A general description of the scoring and ranking system is presented
below.
2 3 4 5 6 7 8 9 10
very poor poor fair good very good excellent
meets meets few meets some meets meets all none many/most
very high high cost medium low cost very low no cost cost cost cost
The scoring of the alternatives for each evaluation criteria is discussed in the following
paragraphs.
4.3.2 Scoring Analysis for Subsurface Soils
Overall Protection of Human Health and the Environment. Contamination which
could pose a threat to human health and the environment is present in the subsurface soils at the
site. Subsurface soils pose a risk to the groundwater. The no action alternative does not provide
protection from these risks. The institutional action alternative limits direct exposure risk by
limiting access and land use. The capping, SVE, and incineration alternatives provide higher
protection, meeting all RAOs and target risk levels. The scoring of the five soil remedial
alternatives is:
BROWN AND CAWWEU 4-14 FnulbilkJ StudJ Repon -Januar, 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3--Containment/Capping
Alternative No. 4--Soil Vapor Extraction
Alternative No. 5-Incineration
Alternative No. 6-Low Temperature Thermal Desorption
2
4
6
8
8
8
Compliance with ARARs. All of the action alternatives will ultimately comply with the
RAOs and target risk levels for soil, but the no action and institutional action alternatives will
take a long time to achieve cleanup goals (longer than the 30-year time period). Containment/
capping will not initially achieve ARARs in the soil beneath the landfill. It will eliminate any
further releases from the site to the subsurface soils and groundwater. The incineration alterna-
tive will comply with ARARs in the shortest time period (within 12 months). SVE is expected
to achieve the ARAR within 5 years. The scoring of the five soil remedial alternatives is:
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3--Containment/Capping
Alternative No. 4--Soil Vapor Extraction
Alternative No. 5-Incineration
Alternative No. 6--Low Temperature Thermal Desorption
3
3
6
7
8
8
Long-Term Effectiveness and Permanence. The no action and institutional action
alternatives may be effective in the long-term due to natural attenuation through bioremedial and
other actions. The same is true for capping, and the cap will limit infiltration and mobilization
of contaminants, thus reducing the levels near the landfill. The SVE and incineration alternatives
will have complete long-term effectiveness and permanence as the impact will have been
remediated. The scoring of the five soil remedial alternatives is:
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3--Containment/Capping
Alternative No. 4--Soil Vapor Extraction
Alternative No. 5-Incineration
Alternative No. 6-Low Temperature Thermal Desorption
4
4
6
8
9
8
Reduction in Toxicity, Mobility, and Volume Through Treatment. Both SVE and
incineration alternatives will reduce the contaminant toxicity and volume through treatment. The
other three alternatives do not initially reduce toxicity and volume as they rely on natural
attenuation. However, the containment/capping alternative effectively reduces the mobility of the
contaminants and does limit the volume of contamination in the soil beneath the landfill. The
alternatives were scored as follows:
Alternative No. I-No Action
Alternative No. 2-Institutional Action
BROWN AND CALDWEU 4-15
3
3
FeasibwlJ Stud1 Report· January 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Alternative No. 3-Containment/Capping
Alternative No. 4--Soil Vapor Extraction
Alternative No. 5-Incineration
Alternative No. 6-Low Temperature Thermal Desorption
6
8
8
8
Short-Term Effectiveness. The first three alternatives have little or no impact on
workers and the community since contaminated media will not be disturbed. SVE will require
approximately several months to implement and short-term hazards will be similar to those
present in performing the RI. The incineration alternative takes over I year to implement and
the protection of workers and the community is at greater risk. The alternatives were scored as
follows:
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3-Containment/Capping
Alternative No. 4--Soil Vapor Extraction
Alternative No. 5-Incineration
Alternative No. 6-Low Temperature Thermal Desorption
8
8
8
6
3
4
Implementability. The no action, institutional action, and containment/capping alterna-
tives are easily implemented. The latter uses standard equipment and well proven technology.
SVE requires investigation and a pilot test to confirm its applicability. The incineration alterna-
tive is more difficult to implement because of the variation in the material to be treated, the
safety controls necessary during the excavation and treatment, and the need to obtain air and
other permits to operate. The alternatives were scored as follows:
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3-Containment/Capping
Alternative No. 4--Soil Vapor Extraction
Alternative No. 5-Incineration
Alternative No. 6-Low Temperature Thermal Desorption
10
9
7
6
3
3
Cost. Costs have been carried forward from the detailed analyses and are compared based
on the present worth cost calculated using an 8 percent discount rate over a period of 30 years.
Scoring is carried out for the range of alternative present worth cost on a linear basis with zero
cost scoring ten points. On this basis, the scoring of the five alternatives for remediation of soils
is:
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3-Containment/Capping
Alternative No. 4--Soil Vapor Extraction
Alternative No. 5-Incineration
Alternative No. 6-Low Temperature Thermal Desorption
BROWN AND CALDWEU 4-16
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7
6
2
3
Fttuibility StudJ Report -Jan-, 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
4.4 SCORING
The comparative total scoring of the five alternatives for soil for the seven criteria is:
Alternative
Criteria 1 2 3 4. 5 6
No action Institutional Containment/ SVE Incineration LTID action capping
Overall protection of human 2 4 6 8 8 8
health/environment
Compliance with ARARs 3 3 6 7 8 8
Long-Term Effectiveness 4 4 6 8 9 8
and Permanence
Reduction in Toxicity, 3 3 6 8 8 8
Mobility, and Volume
Shon-Term Effectiveness 8 8 8 6 3 4
Implementability IO 9 7 6 3 3
Cost 9 8 7 5 2 3
Total scorea 39 39 46 48 41 42
a The total score is a simple arithmetic sum of the individual values and does not reflect any differences in impor-
tance between the various criteria. As such, it should be used for comparative purposes only and is not intended
to indicate preference or be used as the sole alternative selection methodology. It is merely pre:Sented to assist
the reader in comparing alternatives.
4.5 SUMMARY OF THE COMPARATIVE ANALYSIS OF REMEDIAL
ALTERNATIVES FOR SOILS
The no action and institutional action alternatives do not actively reduce the toxicity,
mobility, or volume of these contaminated soils. The institutional action alternative reduces
potential exposure by restricting access and land use at the site. Neither of these alternatives will
meet the RAOs and target risk levels within the 30-year remediation period.
In order for the institutional action alternative to be considered, it would be necessary for
EPA to waive application of the ARARs to this site according to 40 CFR 300.430(t)(l)(ii)(C)(3).
Justification for the waiver would be based on the technical impracticability of reducing contami-
nation within the landfill to ARARs due to the added risk involved in disturbing the landfill, the
low permeability of the soil, and the evidence of very limited migration of contamination and the
trend towards natural attenuation of the contamination within the ground and groundwater.
Containment/capping reduces the mobility of the contaminants very effectively, but does
not actively reduce the toxicity and volume of the contaminated landfill. It would prevent future
releases from the trenches to the unsaturated soil and groundwater. SVE will require further
BROWN AND CAWWEU 4-17 FttUibililJ Study Rq,011 -}a.lUUU'J 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
investigation and a pilot test to confirm its applicability. If applicable, SVE will remove the
VOC contaminants from soil. Incineration will achieve the RAOs in subsurface soils. Incinera-
tion does not transport contaminated soils off-site but, instead, uses the treated soils as backfill
material for the excavated areas. However, incineration does pose a much greater human health
risk during operation because of the excavation and mixing of the chemicals. It also has had
much public opposition.
4.6 INDIVIDUAL ANALYSIS OF GROUNDWATER REMEDIAL ALTERNATIVES
4.6.1 Alternative No. 1-No Action
Under this alternative, no further action would be taken at the site to remove or control
groundwater contamination. The groundwater would be monitored and recorded semiannually
and a status report issued every 5 years in accordance with CERCLA Section 12l(c) to determine
if any migration had occurred. This alternative does not initially reduce the human health and
environmental risks at the site but serves as a baseline with which other alternatives can be
compared.
This alternative relies on the natural attenuation processes of dispersion, dilution, sorption,
and chemical and biological degradation to eventually achieve RAOs. A model was used to
estimate how long it would take for the most prevalent contaminants to reach the first point of
reception, which is at Richland Creek, and the concentration that would be received at that point.
The model showed that it would take about 2,000 years for chloroform to reach Richland Creek
and then it would be at a concentration of 0.5 ppb which is 11200th of the MCL.
Criteria Assessment
Overall Protection of Human Health and the Environment. Alternative No. 1, no
action, would not initially provide greater protection to human health and the environment beyond
that which already exists on this site. However, the shallow groundwater zone beneath the site
is not currently being used for any purpose and there are no downgradient groundwater receptors
within 0.5 mile of the site; hence, no risks from contaminants in the groundwater currently exist.
Potential risks from exposure to contaminants in the groundwater will only exist under a hypo-
thetical future use of the shallow groundwater, which is not likely as the ground in the path of
the contamination is owned by NCSU or is other state-owned property.
This alternative relies on natural attenuation to reduce such hypothetical risks. The no
action remedy does not disturb the natural, stable conditions of the soils and groundwater flow,
and the progress of this natural attenuation could be measured by routine monitoring of ground-
water. Groundwater RAOs will eventually be achieved with no action.
Compliance with ARARs. The no action alternative would not initially comply with
ARARs which are MCLs assuming groundwater is a potential source of drinking water. How-
ever, the isolated water-bearing unit under the site is not used as a drinking water source and the
BROWN AND CA.LDWEU 4-18 F«uibiliJJ SJudJ Report· JOIIIIIU'J 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
natural attenuation described in the RI would result in ARARs later being achieved at Richland
Creek, the nearest downgradient receptor. This justifies consideration of a waiver from the short-
term ARARs on-site according to 40 CFR 300.430(t)(l)(ii)(C)(3).
Long-Term Effectiveness and Permanence. Under this no action alternative, reliance
for long-term effectiveness and permanence would rest on the efficacy of natural attenuation and
degradation. Biodegradation of the groundwater contaminants would result in their.permanent
removal.
Reduction in Toxicity, Mobility, and Volume Through Treatment. The no action
alternative would reduce the toxicity, mobility, and volume of current groundwater contamination
through natural treatment via biodegradation, attenuation, and dispersion.
Short-Term Effectiveness. The short-term effectiveness would be good because under
the no action alternative, no remedial actions are implemented. Therefore, this alternative would
pose no additional risk to the community, site workers, or to the environment due to removal,
handling, or disposal of contaminated media. However, ARARs will not be met for many years.
Implementability. No technology is proposed for the no action alternative and therefore
there would be no restrictions or difficulty with its implementation. Only groundwater moni-
toring through existing wells would be required.
Cost. Although no remedial action would be initiated under the no action alternative,
groundwater samples would be collected semiannually. No drilling cost would be expended,
however, since four selected existing monitoring wells could be used to collect the groundwater
samples. O&M costs consist of collecting samples, laboratory analysis, data reporting, and the
preparation of a public health assessment every 5 years. The present worth cost of the no action
alternative is about $300,000, as detailed below.
Capital Cost
No action
Annual Cost
Monitoring four wells, sampling, laboratory
analyses, and reporting each year
BROWN A.ND C.UDWEU
Contingency
Total annual cost
4-19
Cost. dollars
0
Cost, dollars
22,000
5,500
27,500
FeasibililJ StudJ Report. January 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Present Worth Cost
=
=
0 + 11.26 (27,500)
about $300,000
4.6.2 Alternative No. 2-Institutional Action
This alternative includes the implementation of institutional action and the initiation of
a long-term groundwater monitoring program. The comments made in Alternative No. I apply
to this alternative which also relies on . natural attenuation processes and continued natural
degradation to provide the reduction in contaminant concentrations. Institutional action is added
to this alternative to ensure that the shallow groundwater zone would not be used in the future,
thereby maintaining the current lack of exposure to, and risks from, contaminants in groundwater.
This alternative would utilize deed restrictions to restrict access to contaminated ground-
water on the site. Deed restrictions could include zoning ordinances that prohibit use of ground-
water at the site and in areas downgradient to Richland Creek, during the time that the ground-
water is not usable. These ordinances would stay in effect until the groundwater concentrations
were below the MCLs.
The institutional action alternative would also include the long-term groundwater moni-
toring program described under Alternative No. I. The groundwater monitoring program would
consist of sampling four existing wells beneath and downgradient of the site semiannually for a
period of 5 years. If after the period of 5 years data indicated stable or non-detect contaminant
concentrations, the monitoring schedule would be changed to a yearly event.
Criteria Assessment
Overall Protection of Human Health and the Environment. This alternative would
protect human health and the environment by implementing institutional action to prevent
exposure to contaminants and thereby eliminating the risk. Groundwater sampling would also
be implemented to monitor contaminant concentrations and migration. Residual contamination
would decline by the natural attenuation described. Long-term groundwater monitoring would
be implemented to track the levels and any migration of the contaminated groundwater. In
accordance with CERCLA Section 12l(c), a site review at 5-year intervals would be used to
assess the progress of natural attenuation and to evaluate if other remedial action efforts are
warranted. This alternative would also ensure that the shallow groundwater zone would not be
used, thereby maintaining the current lack of exposure to, and hence risks from, contaminants
in groundwater. By including ongoing monitoring, the alternative also would allow for appro-
priate action to be taken at some point in the future if necessary, as dictated by the monitoring
results.
BROWN AND CAWWEU 4-20 Fe,uibililJ Study Rq,on -J"'"""Y 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Compliance with ARARs. The institutional action alternative would not initially comply
with ARARs which are MCLs assuming groundwater is a potential source of drinking water.
However, the shallow water-bearing unit under the site is not used as a drinking water source and
the natural attenuation described in the RI would result in ARARs being achieveq at the nearest
off-site receptor (Richland Creek). This justifies consideration of a waiver from the short-term
on-site ARARs in accordance with 40 CFR 300.430(f)(l)(ii)(C)(3).
Long-Tenn Effectiveness and Permanence. Under this institutional action alternative,
reliance for long-term effectiveness and permanence would rest on the efficacy of natural
attenuation and degradation. Contaminant concentrations would be monitored and a provision
could be included to initiate a specified remedial alternative should monitoring reveal that
contamination in groundwater has migrated significantly beyond its current distribution or that
concentrations are found to be unacceptable, or pose an immediate threat to human health or the
environment.
Reduction in Toxicity, Mobility, and Volume Through Treatment. The institutional
action alternative would eventually reduce the toxicity, mobility, and volume of current ground-
water contamination. Although this alternative does not initially reduce the risk that may exist
to human health and the environment, it does provide an incremental approach to this issue, by
way of continuous monitoring, with the opportunity to take appropriate action if dictated by the
results from the monitoring operation.
Short-Tenn Effectiveness. The short-term effectiveness would be good because under
the institutional action alternative, no remedial actions would be implemented and thus no
additional risk would be posed to the community, site workers, or to the environment. Also,
implementation of this alternative would immediately ensure that shallow groundwater could not
be used, thereby guaranteeing the current lack of exposure to hypothetical risks from contami-
nation in groundwater.
Implementability. No remedial activity is proposed for the institutional action alterna-
tive. Also, the site is owned by the PRP and site access and usage can easily be controlled/
restricted by deed restrictions. Therefore, this alternative is easily implemented.
Cost. Although no remedial action would be taken under the institutional action alter-
native, the site must be secured, groundwater samples collected semiannually, and deed restric-
tions obtained. Capital costs would include obtaining and recording the deed restrictions. O&M
costs would consist of semiannual sample collection, laboratory analysis and reporting, and the
preparation of a public health assessment every S years. The present worth cost of the institu-
tional action alternative is about $500,000.
BROWN AND CAWWELL 4-21 FearibililJ Study Report• January 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Capital Cost
Deed documentation/agreement
Total capital cost
Annual Cost
Annual cost as Alternative No. 1
Add verification of institutional action, etc.
Total annual cost
Present Worth Cost
PW =
=
25,000 + 11.26 (42,500)
about $500,000
Cost, dollars
25,000
25,000
27,500
15,000
42,500
4.6.3 Alternative No. 3-Groundwater Extraction, Treatment, and Discharge
This alternative consists of extracting the groundwater and treating it on-site through air
stripping followed by GAC adsorption and discharging it to the sewer and thereby to the local
POTW. The used carbon would be recharged off-site and reused.
Two groundwater recovery wells would be installed in the area of the landfill with another
two installed in the area near the downgradient edge of the plume. The contaminated water
would be pumped to the water treatment system, treated and discharged to the adjacent sewer and
local POTW.
The extraction system would also alter the hydraulic gradient, thereby mitigating con-
taminant migration beyond the existing plume area.
This alternative also includes fencing to prevent public access to the extraction and treat-
ment equipment and periodic groundwater monitoring to track changes in the level and extent
of contamination.
The major components of this alternative consist of:
I.
2.
The implementation of institutional action as described in Alternative No. 2.
The design and construction of four groundwater extraction wells.
BROWN AND CAWWEU 4-22 FttuibililJ StudJ Rq,ort · Ja.11,uuy 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
3.
4.
5.
6.
The installation of a security fence around the treatment unit.
The design and installation of a groundwater pumping system, a groundwater
aeration and filtration system, an air stripper and GAC treatment system, and a
retention and recycling system including final discharge to the sewer.
The start-up and operation of this system.
Transportation and disposal of spent GAC.
7. Operation of a long-term groundwater monitoring program.
Criteria Assessment
Overall Protection of Human Health and the Environment. Groundwater extraction
and treatment is the presumptive remedy for contaminated groundwater. However, due to the
nature of the contaminants and the low permeability of the soil matrix, the movement of
contaminated groundwater toward the extraction system may be limited. Therefore, the
groundwater extraction and treatment system may not result in achieving groundwater RAOs, or
at a minimum will take a long time to achieve RA Os. The implementation of institutional action
would ensure that the current lack of exposure to groundwater would be maintained. However,
in the short term this alternative would not be substantially more protective of human health and
the environment than Alternative 2.
Compliance with ARARs. This groundwater extraction and treatment alternative
removes contaminants from the extracted groundwater in compliance with ARARs. However,
the contaminant levels in the in situ groundwater may not be reduced to MCLs for a very long
time, possibly not within the 30-year period considered appropriate, because of the low per-
meability of the soil matrix. Therefore, this alternative may not comply with ARARs.
Long-Term Effectiveness and Permanence. The groundwater extraction and treatment
alternative will be effective in treating the extracted water to permanently meet RA Os. However,
the concentrations and volume of contaminants in the groundwater may still be very slowly
reduced. The pump and treatment system also adds risks as far as reliability and public exposure
are concerned, by removal, handling, treatment, and disposal of contaminants. Natural
attenuation may still be the dominant contaminant removal mechanism and, therefore, this
alternative is not greatly superior to Alternatives 1 or 2 in this regard.
Reduction in Toxicity, Mobility, and Volume Through Treatment. The groundwater
extraction and treatment alternative would diminish the overall mobility of the contaminants. It
would also reduce the toxicity and volume of the extracted contaminants by treatment. Some
reduction in toxicity, mobility, and volume will also occur as a result of natural attenuation.
Short-Term Effectiveness. The groundwater extraction and treatment alternative requires
the installation of four recovery wells and a water treatment system. Installation of equipment
BROWN A.ND CA.WWEU 4-23 FemibUiJ1 SludJ Rqon -January 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
and start-up would take approximately 6 months. The initial impacts on the community and the
environment would be minor (comparable to those incurred during the RI). However, the need
to protect the equipment from vandalism and potential exposure to contaminated groundwater
would be present throughout the operation.
Implementability. Implementation of the groundwater extraction and treatment alterna-
tive would be difficult due to the low permeability of the soils and the long-term operation and
maintenance requirements of the well and water treatment system. The clayey soils would make
the proper development and operation of groundwater extraction wells difficult. The water
extraction and treatment system would have to be replaced due to plugging or silting about every
10 years, or three times in 30 years.
Cost. The groundwater extraction and treatment system would include the costs asso-
ciated with Alternative No. 2, plus the costs of the extraction wells, the treatment system, and
associated monitoring. The present worth cost of the alternative is about $2.1 million.
Capital Cost
Capital cost as Alternative No. 2
Four new extraction wells, pumps,
and piping @ $10,000 each
Treatment plant
Fencing
Engineering and contingency
Total capital cost
Annual Cost
Verification of institutional action
Monitoring extraction and downgradient wells
O&M of equipment and contingency
Replacement every 10 years
Present Worth Cost
PW = 343,500 + 11.26 (156,500)
= about $2.1 million
BROWN AND CAWWEU 4-24
· Cost. dollars
25,000
40,000
136,000
22,500
120,000
343,500
15,000
37,500
100,000
4,000
156,500
FNSibililJ StudJ Rq,on -Jtutuary 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
4.6.4 Alternative No. 4-Biotreatment of Groundwater
The containment/treatment option of groundwater flow control and biotreatment of the
groundwater is a closed-loop system consisting of nutrients and possibly a carbon source (i.e.,
benzoate or acetate) addition into the upgradient groundwater through an infiltration trench to
facilitate bioremediation of the groundwater contaminants, groundwater pumping downgradient
using three extraction wells to control groundwater flow and enable groundwater sampling, and
recirculation of the extracted water. Three extraction wells are proposed in order to create a
combined capture zone at the downgradient portion of the plume, near MW-15. The wells will
also draw down the water level, creating a gradient toward the wells. This alternative would
include monthly groundwater sampling of select existing wells for the first year, followed by
quarterly monitoring thereafter. Institutional action would be implemented for the period that the
groundwater concentrations remain elevated. Additional fencing would be required around the
groundwater pumping units.
The biotreatment alternative is an innovative technology that appears to be a viable
remedial alternative for the groundwater at the Lot 86 site. The primary site contaminants are
chlorinated aliphatic hydrocarbons which have been shown to be fairly readily biodegraded under
proper environmental conditions (Baker and Herson, 1994;1 McCarty, et al., 1984, Appendix I).
The lower molecular weight chlorinated hydrocarbons which are present at the site (chloroform,
carbon tetrachloride, and methylene chloride) are biodegraded under both anaerobic and aerobic
conditions although degradation rates reportedly are faster in anaerobic environments (McCarty,
et al., 1984, Appendix I). At the Lot 86 site, anaerobic conditions would be expected to soon
develop in the center of the contaminant plume where initial aerobic biodegradation of readily
degraded compounds will deplete the available oxygen. Aerobic conditions would be expected
to prevail toward the plume boundaries where contaminant concentrations are lower and bio-
degradation rates will be controlled by the availability of the carbon source rather than by
oxygen.
This technology would minimize risks associated with extraction and treatment of contam-
inated groundwater and disposal of residuals, and would maximize the potential for destruction
of the contaminants through biologically facilitated mineralization. The site contaminants are
primarily aliphatic compounds which have been shown to be degraded under anaerobic rather
than aerobic conditions (McCarty, et al., 1984; Appendix I). Production of intermediates, rather
than mineralization, is not expected to be a problem as the site contaminants are generally
smaller and degraded in relatively few steps. Laboratory studies have demonstrated minerali-
zation of chloroform to CO2 by indigenous methanotrophs without production of stable inter-
mediates (Speitel and Closmann, 1989; Appendix K).
Also, intrinsic bioremediation of chlorinated aliphatic hydrocarbons has been demonstrated
at an NPL site in St. Joseph, Michigan (Wilson, et al., 1994, Appendix G). Active in situ bio-
remediation has also been introduced by EPA as a Bioremediation Field Initiative (EP A/540/F-93/
1 Baker, Katherine H. and Diane S. Herson. 1994. Bioremediation. McGraw-Hill, Inc.
BROWN AND CAWWEU 4-25 F«uibilily Study Rq,ort. Janll4FJ 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
5 IOF, Appendix H). Although not tailored for all of the contaminants present at this site, the
various references included in Appendices I through K demonstrate how this technology can be
modified to cover all contaminants.
The major components of this closed-loop system consist of:
1. The implementation of institutional action as described in Alternative No. 2.
2.
3.
4.
5.
The design and construction of three groundwater extraction wells at the down-
gradient edge of the plume.
The design and installation of a groundwater pumping system, nutrient storage and
mixing facilities, and a groundwater infiltration gallery upgradient of the chemical
trenches.
The installation of a security fence around the extraction well pumps. Additional
fencing is not required around the treatment unit as it can be installed within the
existing landfill fence.
The start-up and operation of this system.
6. Operation of a long-term groundwater monitoring program.
This innovative alternative would require additional investigation and pilot testing to
verify the viability of the technology for this site. Additional investigation would be necessary
to characterize the site geochemistry and to better assess the potential for bioremediation to be
effective at the site. Pilot testing work related to soil permeability similar to that described under
the soils remedial Alternative No. 4 would also be required.
Criteria Assessment
Overall Protection of Human Health and the Environment. The biotreatment alterna-
tive would provide good overall protection to human health and the environment, providing that
the pilot tests confirm that the site geochemistry, microbiology, and soil permeability are suitable
for bioremediation. The extraction wells would provide a barrier preventing further migration
while the closed-loop system bioremediated the groundwater. Institutional action would also be
implemented to restrict access to the site and contaminated groundwater.
Compliance with ARARs. Bioremediation is a protracted process with some uncertainty
about what final residual levels of contamination will remain. It does, however, appear to be
reasonable to anticipate an 80 to 90 percent reduction in contaminant levels over a time period
of 5 to 7 years. This alternative would require some waivers to become an adopted remedy
because RAOs for this site may not be achieved by this alternative.
Long-Term Effectiveness and Permanence. The alternative would be effective in the
long-term because the technology would transform the contaminants to nontoxic constituents.
BROWN AND CAWWEU 4-26 Fnuibilily Study Rq,ort -Januar, 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Reduction in Toxicity, Mobilitv, and Volume Through Treatment. This technology
would reduce the toxicity, mobility, and volume of contaminants by treatment over a period of
approximately 5 to 7 years. The volume and toxicity would be reduced by the in situ biodegra-
dation while the groundwater extraction would limit mobility.
Short-Term Effectiveness. The biotreatment alternative would include the installation
of three new extraction wells to remove the groundwater as well as an infiltration gallery to
introduce nutrients and to recycle water. These activities would not pose a significant risk to
on-site workers or the community. Short-term effectiveness would be enhanced by the imposition
of site access controls and fencing.
Implementability. This remediation scheme would incorporate standard equipment for
the total system and would require low maintenance. This innovative alternative would be
suitable for implementation as a development opportunity for the EPA Superfund Innovative
Technologies Evaluation (SITE) Demonstration Program and could have potential applicability
to similar site cleanup scenarios within EPA Region IV. Involvement in the EPA SITE program
would facilitate implementation of this alternative.
Cost. The layout and equipment list is similar to that for Alternative 3 except there is
only three extraction wells plus an infiltration gallery. However, with the closed-loop system,
no annual cost is required for off-site disposal. Therefore, the present worth cost would be less
than that for Alternative No. 3, approximately $1.6 million.
Capital Cost
Capital cost as Alternative No. 2
Three new extraction wells, pumps,
and piping @ $ I 0,000 each
Infiltration gallery
Storage/mixing system
Engineering and contingency
Total capital cost
Annual Cost
Monitoring wells
O&M of system, equipmenta
Well replacement every IO years
Contingency
Cost, dollars
25,000
30,000
16,000
58,000
80,000
209,000
37,500
65,000
13,000
15.000
120,500
• Annual cost is prorated to reflect monthly monitoring the first year and
quarterly monitoring thereafter.
BROWN AND CAUJWEU 4-27 FeasiblliJJ Study Report -JanUDrJ 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Present Worth Cost
PW = 209,000 + 11.26 (120,500)
= about $1.6 million
4.7 COMPARATIVE ANALYSIS OF GROUNDWATER REMEDIAL ALTERNATIVES
A detailed comparative analysis was performed on the four groundwater remedial alterna-
tives developed during this FS using the seven evaluation criteria detailed at the start of this
chapter. The advantages and disadvantages of each alternative were compared to identify the
alternative with the best balance among these seven criteria. As noted in Section 4.3, the first
two criteria are "threshold criteria" relating to statutory requirements that each alternative must
satisfy in order to be eligible for selection, the next five criteria are "primary balancing criteria,"
which are technical criteria upon which the detailed analysis is primarily based, and the final two
"modifying criteria" may be used by EPA to modify aspects of the specific alternative and are
not addressed here.
A summary of the relative performance of each alternative with respect to the evaluation
criteria is provided in the following subsections. A comparison is made between each of the
alternatives for achievement of a specific criterion.
As an aid to the comparative analyses, an evaluation of all the alternatives was performed
by using a numerical scoring and ranking system for each of the first seven criteria. The scoring
is from I to I 0, with a I being the worst performance in meeting the criteria and 10 being the
best performance. Each of the four alternatives is scored for each of the seven criteria and
cumulative totals are then calculated. These total scores are the arithmetic sum of the individual
values and do not reflect differences in criteria importance. As such, the scoring is presented
merely to assist the reader in comparing alternatives and is not intended to indicate preference
or be used as the sole basis of selection.
2 3 4 5 6 7 8 9 10
very poor poor fair good very good excellent
meets meets few meets some meets meets all none many/most
very high high cost medium low cost very low no cost cost cost cost
The scoring of the alternatives for each evaluation criteria is discussed in the following
paragraphs.
BROWN AND CAWWEU 4-28 Feasibili.lJ StudJ Report -January 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
4.7.1 Scoring Analysis for Groundwater
Overall Protection of Human Health and the Environment. Three of the four alter-
natives would provide protection of human health and the environment because they restrict
exposure to contaminated groundwater by instituting site access controls. Only the no action
alternative does not implement these controls.
Chemicals found in groundwater below the site do not pose a current risk to human health
or the environment. Only under the assumption of hypothetical future use of the groundwater
as drinking water, a highly unlikely scenario, do contaminants in the groundwater pose potential
risks to human health. The necessity for remediation of this groundwater is diminished by the
lack of contaminant mobility in the groundwater due to poorly permeable soils, by the low con-
taminant concentrations found in the groundwater, and by the low aquifer yield.
The scoring of the four remedial alternatives for groundwater is:
Alternative No. 1-No Action
Alternative No. 2-Institutional Action
Alternative No. 3-Groundwater Treatment
Alternative No. 4-Biotreatment
4
6
8
8
Compliance with ARARs. Alternatives 1 and 2 are not expected to achieve RAOs within
a 30-year period. Alternative 3 slightly decreases the time for RAOs to be met because removal
of groundwater and contaminants from the site soils is difficult. Because of the difficulty of
removing sufficient amounts of contaminants from the groundwater under the site to meet
ARARs, it may be appropriate for EPA to consider a waiver of the ARARs to this area according
to 40 CFR 300.430(f)(l)(ii)(C)(3). Justification for the waiver is based on the low permeability
of the soils, the evidence of very limited migration of contamination, and the lack of possible
exposure pathways in the near future. Also, the natural attenuation of contaminant concentrations
in groundwater is occurring at the site.
On this basis, present scoring of the four alternatives for groundwater is:
Alternative No. 1-No Action
Alternative No. 2-Institutional Action
Alternative No. 3-Groundwater Treatment
Alternative No. 4-Biotreatment
3
3
8
6
Long-Term Effectiveness and Permanence. The modeling results presented in the RI
report show that the contaminants will never reach Richland Creek at concentrations above
MCLs. All of the alternatives will achieve the ARARs in the long term, although Alternatives
3 and 4 may decrease the time. Consequently, the scoring of the four alternatives is:
BROWN AND CAWWEU 4-29 FeasibililJ StudJ Rq,or1 • January 1995
CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3--Groundwater Treatment
Alternative No. 4-Biotreatment
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5
8
7
Reduction in Toxicity, Mobility, and Volume Through Treatment. The contaminants
in the groundwater are relatively slow moving. Those that are mobile are also subject to
biodegradation, photolysis, and other processes which limit further migration and attenuate
concentrations over time. This applies equally to all alternatives. Alternatives 3 and 4, however,
will reduce the contaminant toxicity, mobility, and volume in less time than will Alternatives 1
and 2. Groundwater treatment will reduce the mobility of the contaminants 'to a greater extent
than the other alternatives. The scoring of the four alternatives for groundwater is:
Alternative No. I-No Action
Alternative No. 2-lnstitutional Action
Alternative No. 3--Groundwater Treatment
Alternative No. 4-Biotreatment
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4
8
7
Short-Term Effectiveness. All systems are ineffective in achieving cleanup goals in the
short-term. Alternatives I and 2 will cause the least potential for impact to human health and
the environment. The groundwater treatment and biotreatment alternatives will slightly increase
the risk of exposure by extraction and handling of contaminated groundwater. The scoring of
the four alternatives for groundwater is:
Alternative No. I-No Action
Alternative No. 2-lnstitutional Action
Alternative No. 3--Groundwater Treatment
Alternative No. 4-Biotreatment
9
9
6
6
Implementability. The no action alternative is the easiest to implement because there
is no remedial action to implement. Imposing institutional action will typically require some
routine legal actions. The groundwater extraction and treatment system will, at best, require
continual adjustment, maintenance, sampling, and periodic replacement, and it is possible that the
technology will be abandoned due to ineffectiveness. The bioremediation alternative suffers from
the same problems and requires considerable development. The scoring of the four alternatives
for groundwater is:
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3--Groundwater Treatment
Alternative No. 4-Biotreatment
10
9
4
5
Cost. Costs have been carried forward from the detailed analysis and are assembled
showing the present worth cost which was calculated using an 8 percent discount rate over a
period of 30 years. The scoring of the four alternatives for the remediation of groundwater is:
BROWN AND CALDWEU 4-30 Feasibility Study Report -January 1995
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CHAPTER 4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
Alternative No. I-No Action
Alternative No. 2-Institutional Action
Alternative No. 3---{;roundwater Treatment
Alternative No. 4--Biotreatment
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4
The comparative total scoring of the four alternatives for groundwater for the seven
criteria is:
Alternative
Criteria 1 2 3 4
No action Institutional Groundwater Biotreatment action treatment
Overall protection of human 4 6 8 8
health/environment
Compliance with ARARs 3 3 8 6
Long-Tenn Effectiveness 5 5 8 7
and Pennanence
Reduction in Toxicity, 4 4 8 7
Mobility, and Volume
Short-Tenn Effectiveness 9 9 6 6
Implementability lO 9 4 5
Cost 9 8 3 4
Total score3 44 44 45 43
a The total score is a simple arithmetic sum of the individual values and does not reflect any dif-
ferences in importance between the various criteria. As such, it should be used for comparative
purposes only and is not intended to indicate preference or be used as the sole alternative selection
methodology. It is merely presented to assist the reader in comparing alternatives.
4.8 SUMMARYOFTHECOMPARATIVEANALYSISOFREMEDIALALTERNATIVES
FOR GROUNDWATER
The scoring of the alternatives failed to produce a convincing reason for the selection of
any one alternative. Of the alternatives which included active removal or treatment of contami-
nated groundwater, Alternative 3 scored slightly higher than the others, although scores were very
equal. None of the four alternatives may achieve the groundwater RA Os within the 30-year time
frame required. Alternatives 1, 2, and 3 are expected to achieve RAOs eventually. Alternative
3 may achieve RAOs more quickly than Alternatives I and 2, but will be limited in performance
due to the low permeability soils. Alternative 4 will have the same limitations as Alternative 3
but may not be able to achieve MCLs. Alternatives 2 through 4 do provide protection to human
health and the environment by implementing institutional action, thus ensuring that groundwater
is not a drinking water supply until after the RAOs are met.
FS-2\7200Cl-l4.FS
BROWN AND CALJJWEU 4-31 Fmsibilily Study Repor1 -January 1995