PB94-963718
EPA/ROD/R01-94/092
December 1994
EPA Superfund
Record of Decision:
Loring Air Force Base Quarry Site,
Operable Unit 7, Limestone, ME
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0.
FINAL
Loring Air Force Base
Quarry Site
Operable Unit (OU 7)
Record of Decision
September 1994
Prepared for:
Air Force Base Conversion Agency
Loring Air Force Base, Maine
(207) 328-7109
Prepared by:
Service Center: Hazardous Waste Remedial Actions Program
Oak Ridge, Tennessee 31831-7606
Contractor: ABB Environmental Services, Inc.
Portland, Maine 04101
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Section
QUARRY SITE
OPERABLE UNIT 7 RECORD OF DECISION
'LORING AIR FORCE BASE, MAINE
TABLE OF CONTENTS
Title
Page No.
DECLARATION FOR THE RECORD OF DECISION
................ Vll
DECISION SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-1
1.0
2.0
3.0
SITE NAME, LOCATION AND DESCRIPTION......... ... '" 1-1
1.1
QUARRY SITE DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . .. 1-2
4.0
5.1
5.2
5.3
5.4
SITE mSTORY AND INVESTIGATION mSTORY . . . . . . . . . . .. 2-1
2.1
2.2
LAND USE AND REsPONSE HISTORY. . . . . . . . . . . . . . . . . . .. 2-1
INVEsTIGATION HISTORY. . . . . . . . . . . . . . . . . . . . . . . . . . .. 2-1
COMMUNITY PARTICIPATION. . . . . . . . . . . . . . . . . . . . . . . . . .. 3-1
SCOPE AND ROLE OF OPERABLE UNIT OR RESPONSE
. ACTION... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-1
5.0
6.0
SUMMARY OF SITE CHARACTERISTICS.................. 5-1
SOIL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-1
SEDI1t.ffiNT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-5
SURFACE WATER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-5
GROUNDWATER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-8 .
SUMMARY OF SITE RISKS. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-1
6.1
6.2
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HUMAN HEALTH RISK AsSESSMENT. . . . . . . . . . . . . . . . . . .. 6-1
6.1.1 Upper Tier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-8
6.12 Lower Tier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-8
ECOLOGICAL RISK AsSESSMENT. . . . . . . . . . . . . . . . . . . . . .. 6-9
62.1 Upper Tier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 6-10
7~lS
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9.0
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Section
7.0
8.0
QUARRY SITE
OPERABLE UNIT 7 RECORD OF DECISION
"LORING AIR FORCE BASE, MAINE
TABLE OF CONTENTS
(continued)
Title
Page No.
6:3
6.4
6.2.2 Lower Tier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-10
UNCERTAINTY EVALUATION. . . . . . . . . . . . . . . . . . . . . . . .. 6-11
CONCLUSION. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . " 6-12
DEVELOPMENT AND SCREENING OF ALTERNATIVES...... 7-1
7.1
72
STATUTORY REQUIREMENTS/REsPONSE OBJECI1VES . .... .. 7-1
TECHNOLOGY AND AL'IERNATIVE DEVELOPMENT AND
SCREENING. . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . .. 7-2
DESCRIPTION OF ALTERNATIVES. . ... . . . . . . . . . . . . . . . . .. 8-1
8.1
82
8.3
~N~AC110N . ............ ............. ..... 8-1
COVER SYS1'EM ................................... 8-1
ON-SITE SOn. INCLUSION IN EMULSIFIED AsPHALT
(AsPHALT BATCHlNG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8-2
EXCAVATION AND USE AS SUBGRADE MATERIAL FOR
ON-BASE LANDFll.L CAP CONSTRUCTION. . . . . . . . . . . . . . .. 8-3
8.4
SUMMARY OF TIffi COMPARATIVE ANALYSIS OF
ALTERNATIVES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .. 9-1
9.1
.0
9.2
EVALUATION CRITERIA USED FOR DETAll.ED ANALYSIS.. " 9-1
9.1.1 Threshold Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . .. 9-1
9.1.2 Primary Balancing Criteria. . . . . . . . . . . . . . . . . . . .. 9-1
9.1.3 Modifying Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . .. 9-2
SUMMARY OF COMPARATIVE ANALYSIS. . . . . " . . . . . . .. " 9-3
9.2.1 Overall Protection of Human Health and the
Environment. . . . . . . . . . . . . . . . . . ... . . . . . . . . . . .. 9-3
9.2.2 Compliance with Applicable or Relevant and
Appropriate Requirements. . . . . . . . . . . . . . . . . . . " 9-3
9.23 Long-term Effectiveness and Permanence. . . . . . . . .. 9-3
ii
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QUARRY SITE
OPERABLE UNIT 7 RECORD OF DECISION
"LORING AIR FORCE BASE, MAINE
TABLE OF CONTENTS
(continued)
Section
Title
Page No.
9.2.4
Reduction of Mobility, Toxicity, or Volume through
Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 9-4
Short-term Effectiveness. . . . . . . . . . . . . . . . . . . . . .. 9-4
Implementability . . . . .' . . . . . . . . . . . . . . . . . . . . . . .. 9-5
Cost. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9-5
State Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . .. 9-5
Community Acceptance. . . . . . . . . . . . . . . . . . . . . . .. 9-5
9.2.5
9.2.6
9.2.7
9.2.8
9.2.9
10.0 TIIE SELECTED REMEDY. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-1
10.1 C1..EANuP UVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .; 10-1
102 DESCRIPTION OF REMEDIAL COMPONENTS. . . . . . . . . . . . .. 10-1
11.0 STATI.JTORY DETERMINATIONS. . . . . . . . . . . . . . . . . . . . . . .. 11-1
11.1 THE SELECTED REMEDY IS PROTECTIVE OF HUMAN
HEALTH AND THE ENVIRONMENT. . . . . . . . . . . . . . . . . . .. 11-1
112 THE SELECTED REMEDY AITAIN$ ARARs . . . . . . . . . . . . .. 11-1
113 THE SELECTED REMEDIAL ArnON IS COST-EFFECI'IVE . . .. 11~7
11.4 THE SELECTED REMEDY Um.T7.Fs PERMANENT SOLlITIONS
AND ALTERNATIVE TREATMENT OR REsOURCE RECOVERY
TECHNOLOGIES TO THE MAxIMuM EXTENT PRACTICABLE.. 11-8
11.5 THE SELECTED REMEDY DOES NOT SATISFY THE
PREFERENCE FOR TREATMENT WmCH PERMANENTLY AND
SIGNIFICANTLY REDUCES THE TOXICITY, MOBILITY OR
VOLUME OF THE HAzARDous SUBSTANCES AS A PRINCIPAL
ELEMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11-9
12.0 DOCUMENTATION OF NO.SIGNIFICANT CHANGES. . . . . . .. 12-1
13.0 STATE ROLE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13-1
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QUARRY SITE
OPERABLE UNIT 7 RECORD OF DECISION
'LORING AIR FORCE BASE, MAINE
TABLE OF CONTENTS
( continued)
Section
Title
Page No.
GLOSSARY OF ACRONYMS AND ABBREVIATIONS
REFERENCES
APPENDICES
APPENDIX A -
TRANSCRIPT OF 1HE PUBliC MEETING
(JULY 26,1994) AND COMMENT LE'ITERS ON
OU 7 PROPOSED PLAN
RESPONSrvENESSS~Y
LEITERS OF CONCURRENCE
APPENDIX B -
APPENDIX C -
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QUARRY SITE
OPERABLE UNIT 7 RECORD OF DECISION
"LORING AIR FORCE BASE, MAINE
LIST OF FIGURES
Figure
Title
Page No.
1-1
1-2
Location of Quarry Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-3
Quarry Site Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-4
10-1 Locationof Quarry and OU 2 Landfill . . . . . . . . . . . . . . . . . . . . . .. 10-6
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QUARRY SITE
OPERABLE UNIT 7 RECORD OF DECISION
"LORING AIR FORCE BASE, MAINE
LIST OF TABLES
Table
Title
Pa2e No.
5-1
5-2
5-3
Summary of Contaminants of Potential Concern - Upper Tier Soil. .. 5-2
Summary of Contaminants of Potential Concern - Lower Tier Soil. .. 5-4
Summary of Contaminants of Potential Concern - Greenlaw Brook
Wetland and Drainage Ditch Sediment. . . . . . . . . . . . . . . . . . . . . .. 5-6
Summary of Contaminants of Potential Concern - Greenlaw Brook
Wetland and Drainage Ditch Surface Water. . . . . . . . . . . . . . . . . . .. 5-9
5-4
6-1
6-2
Total Site Risks For Each Receptor - Upper Tier. . . . . . . . . . . . . . .. 6-5
Total Site Risks For Each Receptor - Lower Tier. . . . . . . . . . . . . . " 6-6
10-1 Preliminary Remediation Goals For Lower Tier Soil. . . . . . . . . . .. 10-2
10-2 Preliminary Remediation Goals For Upper Tier Soil. . . . . . . . . . .. 10-3
11-1 Chemical-Specific ARARs, Criteria, Advisories, or Guidance. . . . .. 11-2
11-2 Location-Specific ARARs, Criteria, Advisories, or Guidance. . . . . .. 11-3
11-3 Action-Specific ARARs, Criteria, Advisories, or Guidance. . . . . . .. 11-6
".
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DECLARATION
DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND WCATION
Loring Air Force Base (LAFB) Operable Unit (OU) 7, Quarry Site Limestone,
Maine.
STATEMENT OF BASIS AND PURPOSE.
This decision document presents the selected source control and soil remedial action
for the Quarry Site, which comprises OU 7 at Loring Air Force Base, Maine. This
decision document was developed in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as
amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986
(42 U.S.C. ~9601 et ~), and to the extent practicable, the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP); 40 CFR Part 300 et seq
(1990). This decision is based on the administrative ~ecord for the site, which was
developed in accordance with Section 113(k) of CERCLA, and which is available for
public review at. the information repositories located at Roben A Frost Memorial
Library, 238 Main Street, Limestone, Maine, and the Air Force Base Conversion
Agency at LAFB, AFBCAjOL-M, Building 5100, Texas Road, Loring AFB, Maine.
Through the remedial action at OU 7, the u.S. Air Force (USAF) plans to remedy
the threat to human health and the environment posed by the presence of
contaminated soils at the Quarry through the implementation of a source control
remedial action.
The State of Maine Department of Environmental Protection (MEDEP) concurs with
the selected remedy for the OU 7.
ASSESSMENT OF OU 7
Actual or threatened releases of hazardous substances from the OU 7, if not
addressed by implementing the response action selected in this Record of Decision,
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W0099431.080
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DECLARATION
may pose an imminent and substantial endangerment to human health, welfare, and
the environment. .
DESCRIPTION OF THE SELECTED REMEDY
The selected remedy for the Quarry Site is excavation and use of the excavated
material as subgrade fill for on-base landfill cap construction. The major
components of the remedy include:
.
site preparation;
.
excavation of upper and lower tier soil and drainage ditch sediment;
.
placement of excavated soil and sediment at au 2 Landfills as
subgrade material for landfill cap construction;
.
restoration of Quarry wetland;
.
environmental monitoring of the groundwater and Greenlaw Brook
wetland; and
.
five-year site reviews.
The placement of soil and sediment as subgrade material at au 2 lannfil1~ is subject
to the issuance of a Record of Decision for au 2 pursuant to CERCLA and the
NCP which permits such placement. The au 2 Record of Decision is expected to
be issued concurrently with this au 7 Record of Decision.
STATUTORY DETERMINATIONS
The remedy selected by the USAF is protective of human health and the
environment, complies with federal and state applicable or relevant and appropriate
requirements for this action, and is cost-effective. This remedy uses permanent
solutions and alternative treatment technologies to the maximum extent practicable.
Installation Restoration Program
WOO99431.080
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'-
DECLARATION
The selected remedy does not, however, satisfy the statutory preference for remedies
that employ treatment that reduces toxicity, mobility, or volUme as a principal
element. The selected remedy will reduce mobility of conrnminants through the
containment features of the landfill cover system at au 2, which will also reduce
rainwater infiltration, erosion, and direct .contact with the cODtamin~ted soil and
sediment.
DECLARATION
The foregoing represents the selection of a remedial action under CERClA for
OU 7 by the USAF and the USEPA-New England, with the concmrence of the
MEDEP.
or immediate implementatio .
By:
Date
Alan K.
Director
Air Force Base Conversion Agency
By:
to \ \ -
~k \ . V"-- Date:
John P. DeVillars
Regional Anmini"trator
USEP A-New F.n~Jand
~ I~ G..9-
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SECTION 1
DECISION SUMMARY
1.0 SITE NAME, LOCATION AND DESCRI~ON
Loring Air Force Base (LAFB) is a National Priorities List (NPL) site. There are
currently 21 areas of concern within LAFB that are under investigation. The areas
of concern at LAFB have been organized into several operable units (OUs) for
remediation purposes. This Record of Decision (ROD) relates to the Source
Remedial Action for OU 7, which is comprised of the Quarry Site soils and
sediments. .
LAFB, in northeastern Maine, is bordered on the south and east by the Town of
Limestone, on the north by the towns of Caswell and Connor, and on the west by the
City of Caribou. The populations of Caswell, Connor and Limestone are 408, 468,
and 2,093, respectively. The base population will be zero beginning October 1994.
The base is approximately 3 miles west of the United States/Canadian border and
covers approximately 9,000 acres. Base operations are expected to gradually.
decrease until base closure in September 1994. The nearest residence is
approximately two miles west of the Quarry and the land adjacent to the Quarry is
the Greenlaw Brook wetlands.
Because of its primary mission, LAFB personnel have been engaged in various
operations, a number of which require the use, handling, storage, or disposal of
hazardous materials and substances. In the past, these materials entered the
environment through accidental spills, leaks in supply piping, landfilling operations,
burning of liquid wastes during fire training exercises, and the cumulative effects of
operations conducted at the base's flightline and industrial areas. As part of the
Department of Defense's (DOD) Installation Restoration Program (IRP), l.AFB has
initiated activities to identify, evaluate, and remediate former disposal or spill sites
containing hazardous substances.
Since initiation of the IRP, the base has been placed on the U. S. Environmental
Protection Agency's (USEPA) NPL of sites and will be remediated according to the
Installation Restoration Program
W0099431.080
1-1
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SECl10N 1.
Federal Facility Agreement (FFA) entered into by the U.S. Air Force (USAF), the
USEP A, and the state of Maine Department of Environmental Protection (MEDEP).
1.1 QUARRY SITE DESCRIPTION
The Quarry Site encompasses approximately seven acres and served as a source of
limestone rock for LAFB from 1947 to 1985. The site is located along the
northwestern boundary of the Nose Dock Area (NDA), approximately 800 feet east
of the western base boundary (Figure 1-1). ~ite topography reflects past quarrying
activities.
The Quarry consists of two levels, the upper and lower tiers. The circular shaped
lower tier of the Quarry, approximately two acres in size, is flooded seasonally and
drains through an excavated ditch into the Greenlaw Brook wetland, part of the west
branch of Greenlaw Brook (see Figure 1-2). The Greenlaw Brook wetland is a 40-
to 50-acre emergent marsh/forested wetland located approximately 600 feet west of
. the Quarry Site at its closest point Approximately 95 percent of the lower tier (i.e.,
approximately 1.9 acres) consists of an emergent marsh wetland area.
The upper tier of the Quarry, approximately 2.5 acres in size, is crescent-shaped,
bordered on the north and east by debris (i.e., rock and construction debris), with
slopes and bedrock escarpments rising approximately 30 feet toward the NDA To
the west, the upper tier of the Quarry drops approximately 30 feet to the lower tier.
The upper and lower tiers each have independent access roads from the south (see
Figure 1-2).
A more complete description of the Quarry Site can be found in Section 2 of the
Remedial Investigation (RI) Report (ABB Environmental Services, Inc. [ABB-ES],
1993).
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I
I
I
I
I
-,
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I .
-----------~------
. I
I
I
I
I
I
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~
Connor
Caribou
..,;
LORING AIR
FORCE BASE
I
o
SCALE IN FEET
.
4000
I
8000
93090170
Caswell
LORING AIR FORCE BASE
~ARRYSnE
Limestone
----- TOWN LINE
FIGURE 1-1
LOCATION OF QUARRY SITE
LORING AIR FORCE BASE
LIMESTONE. MAINE
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'""'
~
@ ... JIll..
.. .ill..
.III.. ..
.iII..
.III..
..
JIll..
.ill.. .ill..
)
RIDGE SEPARATING
LOWER TIER FROM
UPPER TIER
Braided Strllam
Open Dry Area
~r'.
\
FIGURE 1-2
SCALE IN FEET
I I
o 200
SOURCE: J.W. SEWAll CO., 1988.
940er
LEGEND
mmiffi~ STANDING WATER
f"YV"'I EDGE OF WOOOED AREA
NOTE:
THE BOUNDARY OF THE GREENLAW BROOK
WETLAND IS APPROXIMATE AND HAS BEEN
INFERRED FROM USGS TOPOGRAPHIC
MAPS, FielD SURVEY DATA AND AERIAL
PHOTOGRAMMETRY.
QUARRV SITE FEATURES
I
400
LORING AIR FORCE BASE
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SECTION 2
2.0 slm HISTORY AND INVESTIGATION HISTORY
1bis section summarizes the uses, response history, and investigation history at the
Quany Site.
2.1 LAND USE AND RESPONSE HISTORY
The Quarry Site encompasses approximately seven acres and served as a source of
limestone rock for LAFB from 1947 to 1985. Historically, waste materials from
construction projects, industrial and maintenance shops, and other base activities
were stored at the Quarry Site. Approximately 100 55-gallon drums were observed
in the upper tier of the Quany in 1983 (ABB-ES, 1993). The original contents of the
drums were unknown. Base personnel reported that the drums were empty in the
early 1980s and that they were removed from the site, crushed, and disposed of in
1983 or 1984. Five-to-IO additional drums were again observed at the site in 1985.
Overall, there have been miscellaneous reports of drums at the site throughout the
19805. These drums have since been removed Documentation of where the drums
were located is limited, although reports consistently note their presence at the
eastern and northern portions of the upper tier of the Quarry.
A more complete description of the Quarry Site can be found in the RI Report at
Pages 2-1 through 2-3 (ABB-ES, 1993).
2.2 INVESTIGATION HISTORY
The investigation history of au 7 is summarized as follows:
.
In 19.84, a Preliminary Assessment (PA) was completed detailing
historical hazardous material usage and waste disposal practices at
LAFB (CH2M Hill, 1984).
.
Initial Site Investigation (51) field work to determine if contaminants
were present at the au 7 site was conducted in 1985 (Weston, 1988).
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SECI'lON 2
.
An RI process commenced in 1988 and continued.into 1994.
.
LAFB was added to the NPL in February of 1990.
.
The USAF entered into an FFA (FFA, 1991) in 1991 with the USEPA
and MEDEP regarding the cleanup of environmental conVimin:ttion at
lAFB. The FFA was revised in December 1993 to address base
closure related issues, such as real property transfer and a revised
schedule.
.
A Feasibility Study (FS) (ABB-ES, 1994a) was completed in 1994 for
the Quarry Site to determine alternatives for remediation of
contamination based on information presented in the RI report, and
a Proposed Plan (ABB-ES, 1994b) was submitted for public review.
...':
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SECI10N 3
3.0 COMMUNITY PARTICIPATION
Throughout LAFB's history, the community has been active and involved to a high
level in base activities. The USAF and USEP A have kept the 'community and other
interested parties apprised of LAFB activities through informational meetings, fact
sheets, press releases, public meetings, site tours and open houses, and Restoration
Advisory Board (RAB) meetings. The RAB is chaired by USAF and community
representatives.
During August of 1991, the LAFB Community Relations Plan (CRP) was released.
The CRP outlined a program to address community concerns and keep citizens
informed about and involved during remedial activities. The CRP can be found in
the admini!::trative record.
On June 24, 1992, the USAF initially made the LAFB admini~tive record available
for public review at the Robert A Frost Memorial Library, 238 Main Street,
Limestone, Maine and at the Air Force Base Conversion Agency, AFBCAjOL-M,
Building 5100, Texas Road, Lo~g AFB, Maine. The arlmini~trative record was
updated on July 14, 1994 to include au 7 information. The USAF published a
notice and brief analysis of the Proposed Plan in the Bangor Daily News and the
Aroostook Republican on July 13, 1994 and made the plan available to the public at
the Robert A Frost Public Library. .
From July 15, 1994 through August 15, 1994, the USAF held a 3O-day public.
comment period to accept public input on the alternatives presented in the RIjFS
and the Proposed Plan, and on any other documents previously released to the
public. On July 26, 1994, LAFB personnel and regulatory representatives held a
public meeting to discuss the Proposed Plan and to accept any oral comments. Local
television and radio stations provided coverage of the public meeting. A transcript
of this meeting is included in Appendix A Comments received during the comment
period, and the USAF's response to comments are included in the Responsiveness
Summary in Appendix B. Based on public comments, the public is in agreement
regarding the preferred Remedial Alternative for au 7 as presented in the Proposed
Plan.
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SECTION 4
4.0 SCOPE AND ROLE OF OPERABLE UNIT OR RESPONSE ACTION
The selected remedy was developed by combining components of different source
control alternatives to obtain a comprehensive approach for source remediation. The
selected remedy for OU 7 is excavation of the Quany Site and use of the excavated
material as subgrade fill for on-base landfill cap construction. The major
components of the remedy include:
.'
site preparation;
.
excavation of upper and lower tier soil and drainage ditch sediment;
.
placement of excavated soil and sediment at OU 2 Landfills as
subgrade material for landfill cap construction;
.
restoration of Quarry wetland with wetlands of size and value equal or
greater than the affected wetlands;
.
environmental monitoring of the groundwater and Greenlaw Brook
wetland; and
.
five-year site reviews
The placement of soil and sediment as subgrade material at OU 2 landfills is subject
to the issuance of a Record of Decision for OU 2 pursuant to CERCLA and the
NCP which permits such placement. The OU 2 Record of Decision is expected to
be issued 'concurrently with this OU 7 Record of Decision.
As part of IRP activities at LAFB, wetland areas located on the base which may be
impacted by remediation are being evaluated as part of OU 13, the basewide surface
water and $ediment operable unit. Therefore, the final approach to the wetland
restoration at the Quarry Site will be addressed in OU 13. While this ROD
addresses only soils and sediments at the Quarry Site, groundwater will be monitored
as part of the environmental monitoring activities at the site. H this monitoring
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SECTION 4
indicates that groundwater has been negatively impacted, additional actions will be
taken under au 12, the basewide groundwater operable unit. .
--c:~
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SECI'lON 5
5.0 SUMMARY OF SITE CHARAcrERISTICS
Subsection 2.4 of the FS (ABB-ES, 1994a) contains an overview of the Remedial
Investigation at OU 7, including discussions on the nature' and distribution of
contaminants. The significant findings of the RI are summarized below.
5.1 SOIL
The fill material in each tier of the Quarry was sampled as follows: (1) upper tier
up to 10 feet below ground surface (bgs); and (2) lower tier up to 2 feet bgs. Soil
samples from each tier were analyzed for volatile organic compounds (VOCs),
semivolatile organic compounds (SVOCs), pesticides, polychlorinated biphenyls
(PCBs), and inorganics. Tables 5-1 and 5-2 summarize the cont~min~nts detected
in upper and lower tier soil, respectively, presenting the minimum and maximum
concentrations detected, as well as the frequency of detections.
Except for carbon tetrachloride, detected at 0.0080 milligrams per kilogram (mgJkg),
no VOCs were detected in soils collected from the Quarry.
SVOCs are widespread in both the upper and lower tiers, with no consistent pattern
of distribution. area1ly, with depth, or by tier. The SVOCs detected were
predominantly polynuclear aromatic hydrocarbons (P AHs), which is a phrase to
describe cyclic organic compounds in which two or more (polynuclear) benzene rings
(aromatic) are bonded together. Total PAHs (i.e., the sum of individual PAHs
detected) range from 1.0 to 50 mgjkg. The only non-P AH SVOC detected
consistently was dibenzofuran, which also appears to be evenly distributed in soils
across the lower and upper tier.
Pesticides considered to be con~minants of potential concern were detected in soils
in both the upper and lower tiers (see Tables 5-1 and 5-2) with no consistent pattern
to their distribution areally, or with depth. PCBs considered to be contaminants of
potential concern were detected in tbe central and extreme portions of the upper
tier. There is no clear source area or consistent distribution of PCBs in the upper
tier.
Installation Restoration Program
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TABLE 5-1
SUMMARY OF CONTAMINANTS OF Pan:NTw. CONceRN - UPPER TIER SOIL
,
au 7 RECORD OF DECISION
loRING AIR FORCE BASE
... "
. .. . . .
.. ",,".., .:.",'..." "":-:""':""""':":';':'-::"""""'."'.', ',',""," . "".. . ,.' .
'SOILS,(Of~~'~E#tj:B~J,"):,\;:i\:')", '" , , .... ..:::::::, ':::{::::; .., ".... ,..::,.,:,',',',:,.." ,:":,',""',:,F,,,.':RO'" E~,::~,.',':,...'ON...":!'pF,:,:::,',:":.':.:,.,':,:":,:,':'::':"'".,1, ,BACKGROUND ,
P'C~~~,.,,:j!": ' "',',:,...., ~ T ',' "'(rDg/lc~)«~b:(~;~~),
.",.,",'
..".
SVQCs
2-Methylnaphthalene 0.049 5.9 8/15 NA
Acenaphthene 0.053 0.85 8/24 NA
Anthracene 0.040 2.1 11/24 NA
Benzo(a)anthracene 0.11 33 14/24 NA
Benzo(a)pyrene 0.064 45 14/24 NA
Benzo(b)f\uoranthene 0.070 39 17/24 NA
Benzo(k)f\uoranthene 0.070 36 11/19 NA
Benzo(g,h,i)perylene 0.060 21 7/24 NA
Benzoic acid 0.050 0.088 2/24 NA
Chrysene 0.12 37 15/24 NA
Dibenzofuran 0.048 0.59 6/24 NA
Fluorene 0.090 1.1 9/24 NA
Fluoranthene 0.050 43 20/24 NA
Hexachlorocyclopentadiene 0.089 0.089 1/24 NA
Indeno(1,2,3-cd)pyrene 0.28 20 5/24 NA
Naphthalene 0.050 1.9 5/24 NA
Phenanthrene 0.050 8.7 20/24 NA
Pyrene 0.090 67 20/24 NA
Pesficides/PCBs
4,4'-000 0.049 0.93 8/16 0.064
4,4' -DOE 0.038 1.2 2/16 0.055
4,4' -DDT 0.066 7.3 8/16 0.089
Aroclor-1248 0.19 4.0 6/16 NA
Aroclor-1254 0.60 0.60 1/16 NA
Endrin ketone 0.18 0.18 1/16 NA
alpha-Chlordane 0.036 0.036 1/16 NA
gamma-Chlordane 0.055 0.055 1/16 NA
WOOB9412T.1/1
-------
(continued)
T~ 5-1
SUMMARY OF CONTAMINAN1S OF POTENTIAL CONCERN - UPPER TIER SOIL
. au 7 RECORD OF DECISION
LoRING AIR FORCE BASE
'1!~lliffJ~~~~r&,:]ti~i";1r~~!":1~~:r_~:~)
Inoraanics
Antimony 6.3 21 17/18 <0.20
Chromium 24 62 6/6 59
Cobalt 13- 16 6/6 14
Lead 8.6 160 6/6 35
Vanadium 12 48 6/6 47
Other
Total Petroleum Hydrocarbons 86 16,000 14/14 NA
.t88:
8 Lavel C and Level D sample results
b Base-wide soil background concentration
NA .. no background data available
5-3
-------
TABLE 5-2
SUMMARY OF CoNTAMINANTS OF POTENT1AL CONCERN - loWER TIER SOIL
au 7 RECORD OF DECISION
LoRING AIR FoRce BASE
'''' .
'~OILS«();;2~~'~~::::'?'H' ' , , H H""" H': ,::'H::::, H"H'H' , " H' "MAXIMUM
":',':',',,,',',:F,':::",.,:,R"",',DEQUEN,:,~-,':,':,','.:.',:,:,"",',.,:,',:",:,',',',',""',,:"",.,:.'.,".',:':ON.,,,',"'."',:':':,:,:",:,:,i,',OF,',:,.,.",',"'::",',:""",'",:,:,'"",":"':':,','"",.",:":".,.,,:,,:',:,,.,',,',',,:,:,.,,:,.,:,,'::,,:,,.':,:'"":',,."",.:".C.,,:.:, 'ONCB,".'"',','A!,',."""CICi,,,,'",;:.L, ,',GR""",',,(.m:,"', Outm, ','g', .",/:,., ':"k:":9")
. ...\C~~1I'~t.Jf';~~~:;! 1~T; ~_.. u
';;:;:;:::;::..;.';;.
::':::;::::::':::':;;;.'
VOCs
Carbon Tetrachloride 0.0080 0.0080 1/10 NA
SVOCs
2-MethytnaphthaJene 0.55 1.3 3/10 NA
Acenaphthene 0.51 3.9 5/10 NA,
Acenaphthytene 0.35 0.35 1/10 NA
Anthracene 0.28 7.5 10/10 NA
Benzo(a)anthracene 1.4 4.8 8/10 NA'
Benzo(a)pyrene 1.0 11 10/10 NA
Benzo(b)fluoranthene 1.5 23 10/10 NA
Benzo(g,h,i)perylene 0.49 1.7 2/10 NA
Benzo(k)fluoranthene 1.1 16 10/10 NA
Chrysene 1.3 20 10/10 NA
Dibenz(a,h)anthracene 0.70 1.2 2/10 NA
Dibenzofuran 0.66 3.1 4/10 NA
Fluoranthene 3.0 40 10/10 NA
Fluorene 0.64 4.8 5/10 NA
Indeno(1,2,3-cd)pyrene 0.52 1.8 3/10 NA
Naphthalene, 0.57 0.57 1/10 NA
Phenanthrene 1.0 26 8/10 NA
Pyrene 2.0 27 10/10 NA
Pesticides
4,4'-000 0.11 0.40 9/10 0.064
4,4'.DDT 0.033 0.19 1/10 0.089
Inoraanics
Antimony 9.8 30 10/10 <0.20
Barium 54 310 10/10 130
Lead 22 58 10/10 35
Mercury 0.07 0.15 1/10 <0.10
Selenium 0.55 0.55 1/10 <0.20
Other
Total Petroleum Hydrocarbons 2,000 9,800 10/10 <0.20
10181:
8 Level C and Level D sample results
b Base-wide soil background concen1ra1ion
NA = no background data available
WOO89412T.1/3
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SECTION 5
Various inorganic analytes were detected above established background levels across
both tiers at all depths in Quarry soils. However, some inorganics such as calcium,
magnesium., and sodium are essential nutrients and therefore, were not selected as
contaminants of potential concern. Only data that meet Leve~ C or D data quality
levels (Le., validated laboratory analytical data) are sufficient for use in a risk
assessment and thus considered when selecting conP'lmin~nts of concem A snrnm::ny
of inorganics detected in Quarry soil that are considered to be site-related is
provided in Tables 5-1 and 5-2. In addition, Toxicity Characteristic Leachate
Procedure (TCLP) data collected in March 1994 for Upper Tier soil showed that
concentrations of inorganics in soil were belQw regulatory levels for TCLP metals.
5.2 SEDIMENT
VOCs, SVOCs, pesticides, PCBs, and inorganic analytes were detected in sediment
in the drainage ditch exiting the Quarry and in the Greenlaw Brook wetland (see
Table 5-3). VOCs were detected sporadically at low levels in sediments
downgradient from the Quarry during four sampling events (i.e., four detects out of
14 samples in four years). The SVOCs detected were predominantly PAH
compounds. The list of PARs, pesticides, PCBs, and inorganic analytes detected in
the sediment is very similar to the contaminants detected in soil at the Quarry. The
similarity of the cont~mimmts in these media indicates that contaminated soil is being
eroded from the Quarry by rain and melting snow, thereby mobilizing these
contaminated sediments to the drainage ditch and eventually to the Greenlaw Brook
wetland. Some SVOCs (Le., 4-methylphenol and benzoic acid) have been detected
at concentrations lower than sample quantitation limits in the Greenlaw Brook
wetland upstream of the Quarry's influence. This suggests there may be unidentified
upstream sources contributing SVOCs to this wetland in addition to the effects of the
Quarry Site. This will be addressed further as part of the basewide surface water and
sediment operable unit (i.e., OU 13).
5.3 SURFACE WATER
Detections of contaminants in surface water from the drainage ditch exiting the
Quarry and in the Greenlaw Brook wetland were exclusively inorganic analytes
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TABLE 5-3
SUMMARY OF CONTAMINANTS OF POTENTIAL CONCERN - GREENLAW BROOK WETLANo AND DRAINAGE DITCH
SEDIMENT
au 7 RECORD OF DeCISION
LoRING AIR FoRce BAse
" ,
.):.:::i?ti:""., ,::::::h::{>",:: ..:'/:'.::))::, H:/:/.:::, ,:ii, "".,., ,', ",,'::, ".;::.,.:.:i ,,'. "1\1'" ". "', ,"',',,','
_.,~::.i0jD~~~~~:I~/i~.':'::~::"',,.(','m=g~~/~,,',L,..'.~,:)::.:,.,',.::.:;:...'.:,:,:..,,:,':,:,>,:,...:"'::.\,,::.\,,,,~,.,~,':.,.,.,:,,:,..:,',i~::,.":,.,,;,.,,~.:,:,,;..,,.,:..:,.~,'~,',:,',~.l..'.'.',..'k',:.:,',~g')",',::.'.'.'.'...:,':.,',.,'~i%",F:.,.,'.:.:,:,:,~'(D',!.~.~..,'...,:,.,"..i.','..,.:..~':~ON'.'.:,;...~,'.',.,:,':'..".,,:,::~,.:;.:'.:,:'.:,;,':::',.:::1".C~ON:.~,:C.~,'.:~,~,','.',':,:'~::."":,~,:~9~/.':k:~gH),
~~~.:!:::::i'::':',:;:::{:::::::::" A. ,.~.. ""..-.,. HH,...
'H
H
....... .
VOCs
Trichloroethene 0.0050 0.0050 1/12 NA
SVOCs
2-Methylnaphthalene 0.11 0.11 1/16 NA
4-Methylphenol 0.16 0.42 3/16 NA
Anthracene 0.085 0.37 3/16 NA
Benzo(a)anthracene 0.73 1.5 4/16 NA
Benzo(a)pyrene 0.73 1.4 3/16 NA
Benzo(b)fluoranthene 0.18 2.5 5/16 NA
Benzo(g,h,i)perylene 0.71 0.72 2/16 NA
Benzo(k)fluorantihene 0.19 2.5 3/15 NA
Benzoic acid 0.093 0.67 3/10 NA
Butylbenzylphthalate 0.11 0.11 1/16 NA
Carbazole 0.18 0.18 1/5 NA
Chrysene 0.93 3.2 4/16 NA
Dibenz(a,h)anthracene 0.38 0.38 1/16 NA
Fluoranthene 0.074 6.4 6/16 NA
Fluorene 0.21 0.21 1/16 NA
Indeno(1,2,3-cd)pyrene 1.1 1.5 3/16 NA
Phenanthrene 0.29 2.4 4/16 NA
Pyrene 0.077 4.2 6/16 NA
Pesticides/PCBs
4,4'-DOO 0.088 0.75 6/13 0.011
4,4'-ODE 0.10 0.19 3/13 0.019
4,4'-DDT 0.76 0.76 1/13 0.020
Aldrin 0.052 0.052 1/13 <0.018
Arodor-1260 0.56 0.56 1/13 <0.096
alpha-Chlordane 0.0070 0.0070 1/13 <0.0049
gamma-Chlordane 0.059 0.059 1/13 <0.0049
WOO89412T.1/4
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(continued)
TABLE 5-3
SUMMARY OF CONTAMINANTS OF POTENTIAL CoNceRN - GREENLAW BROOK WETlAND AND DRAINAGE DITCH
SEDIMENT
au 7 RECORD OF DECISION
LoRING AIR FORCE BASE
, ,
. '''''':';';:.:.'.':;:;:,;'''....,:::::"'.;:':;-.::":';:.;.;.:.:.',...
. ""':, .:::;:~.~..~~~ :;:!i!; :~:~)~:;~;: :;>. ;;:;:i'~[~~':~;!:!;;j::~~i;!~r::.: .'. .:;!:;:~',.::: . ',:.:: . : : .
",.',':: :'."',,' ,", ,;;",,;." ,'"
,,',;":,i;::,:~d4~:: ' HHH
. . .. ""
. .. .. ... ... ....
',:, H " ':.H' ""':'H'??,',:,:,,::' ','.,"H,:i H:H:,:/::,:::,::::;;:):(:;:;;,:"t:~=D:
'. '.... '.' .'. .'~~"~';.W~~:;~~~J~RI"~'!~'f01'~~)(mgJI'IJ)
H
':.;, "
, '
Inoraanics
Aluminum 7,000 31,000 13/13 21,000
Arsenic 0.92 18 7/13 7.6
Barium 26 940 13/13 96
Beryllium 0.44 0.89 4/13 0.63
Cadmium 15 15 1/13 <0.79
Chromium 16 64 12/13 37
Iron 8,300 62,000 13/13 37,000
Lead 5.2 62 13/13 17
Nickel 13 82 11/13 47
SUver 3.5 3.5 1/13 <2.6
Vanadium 12 64 12/13 200
Zinc 37 200 13/13 200
10.
. Level C and I..evel D sample results
b March , 993 USGS background data
NA = no background data available
WOO89412T. '/5
-------
SECI'lON 5
except for one detection of gamma-BHC (Lindane) (see Table 5-4). Inorganic
concentrations detected in surface water samples may be due to the presence of
suspended solids in surface water samples. The samples were not filtered prior to
analy~s. ,
5.4 GROUNDWATER
Six wells were sampled in the vicinity of the Quarry between 1988 and 1991. The
results of these data are presented in the OU 7 RI (ABB-ES, 1993). With the
exception of sporadic detections of SVOCs and pesticides, most of the contamin~nts
detected in groundwater were chlorinated solvents and fuel constituents (Le.,
benzene, toluene, ethylbenzene, and xylene). Chlorinated solvents detected in the
groundwater beneath the Quarry include 1,1-dichloroethene, totall,2-dichloroethene,
1,1,2-trichloroethane, tetrachloroethene, chlorobenzene, trichloroethene, and vinyl
chloride. Groundwater quality in the fill material has never been determined. VOCs
detected in groundwater have only been found in bedrock and only upgradient,
beneath the upper tier soils. The list of VOCs in groundwater does not correspond
to the types of contaminants detected consistently in soil or sediment: pesticides,
PCBs, and SVOCs.
No organic contaminants, with the exception of sporadic detections of two SVOCs
(i.e., dimethylnaphthalene and N-nitrosodiphenylamine), were detected in the
presumed downgradient well (i.e., RFW-50). In addition, based on field screening
results, no VOCs were detected in the well closest to the lower tier; however,
analytical results from this well were not confirmed by an off-site laboratory.
Remedial alternatives for groundwater associated with au 7 will be addressed as
part of OU 12, as necessary.
A complete discussion of site characteristics can be found in the RI Report at
Pages 2-18 through 2-25. .
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TABLE 5-4
SUMMARY OF CoNTAMINANTS OF POTENTIAL CONCERN - GREENLAW BROOK WETlAND AND DRAINAGE DITCH
SURFACE WATER
au 7 RECORD OF DECISION
LDRING AIR FORCE BASE
".
,.:..;:,:::,:;:'
. ,.... .
.:."::,,,.;.;".:.:.
'.:.;...:,'
"... ........ .. ..
."" ",..'.' ..'.' ..,.,...,...",...,,,.'.,.' .'..'.'."""'.""".","'''''.'''''.'''''''''''''''''.'''''''.' . .. ... .. . . MAxIMUM
"~u..M~:~.: '~~:~~:''':'''~'',''D. "'E1"ECTI."':':;"':, io.:,':.:,:,.,,':,:,',,:.:..,'.::,..,j,:'.","::'.":'.."'CONi~C:,'.,....':.It'GR..'.'.'.,('.m'~''.'g:"'.'I1"":..'" \
,.." ,'" . (mg~)"'..'."""(mgtL)f':""" Wft /,...,
.:','," :,',
"',""'::..:',
. ".. .,' ~,::,'.':.';;.,':.,<.i,'.;;~'/:,.,;;:;;'::"" .... ,:.;':..::'; ,', ::', }r?t~:~.:
'':;:;(::;~~i:{' . .... .. ...', .. ..........
'.ii~:,:::~~~~':.i:i::"
. ..
...'
. ."
SVOCs
Bis(2-ethylhexyl) phthalate 0.0040 0.0040 1/12 NA
Butylbenzylphthalate 0.0030 0.0030 1/12 NA
Di-n-butylphthalate 0.0010 0.0040 2/12 NA
Di-n-octylphthalate 0.0020 0.0020 2/12 NA
Pesticides
gamma-BHC (Undane) 0.00025 0.00025 1/9 <0.000050
Inoraanlcs
Aluminum 0.20 0.61 4/9 <0.055
Barium 0.0074 0.056 5/9 0.014
Cadmium 0.006 0.006 1/9 <0.0014
Cyanide 0.011 0.011 1{7 0.010
Iron 0.39 0.87 3/9 <0.16
Lead 0.0032 0.0032 1/9 0.0021
Manganese 0.015 0.14 5/9 0.026
Zinc 0.011 0.027 2/9 <0.011
l11li:
. Level C and Level D sample results
b March 1993 USGS background data
NA= no background data available
:
WOO89412T.1/6
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SECTION 6
6.0 SUMMARY OF SITE RISKS
A baseline risk assessment (RA) was performed to estimat~ the probability and
magnitude of potential adverse human health and environmental effects from
exposure to contaminants associated with the Quarry Site (ABB-~S, 1993). The
human health risk assessment followed a four step process:
1)
contaminant identification, which identified those hazardous substances
which, given the specifics of th~ site, were of significant concern;
2)
exposure assessment, which identified actual or potential exposure
pathways, characterized the potentially exposed populations, and
determined the extent of possible exposure;
3)
toxicity assessment, which considered the types and magnitude of
adverse health effects associated with exposure to hazardous
substances; and
4)
risk characterization, which integrated the three earlier steps to
summarize the potential and actual risks posed by hazardous
substances at the site, including carcinogenic and non-carcinogenic
risks.
The results of the human health risk assessment for the Quarry Site are discussed
below, followed by the conclusions of the environmental risk assessment.
6.1 HUMAN HEALTH RIsK AsSESSMENT
Twenty-eight contaminants of potential concern (CPCS) for the upper tier soils, 22
for the lower tier soils, 31 for sediment from the Greenlaw Brook wetland and
drainage ditch, and eight for surface water from the Greenlaw Brook wetland and
drainage ditch were selected for evaluation in the risk assessment. These CPCS are
listed in Tables 3-1 through 3-4 of the FS. These contaminants constitute a
representative subset of all contaminants identified at the Quarry Site during the RI.
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SECI'lON 6
The CPCs were selected to represent potential site-related hazards based on toxicity,
concentration, frequency of detection, and mobility and persistence in the
environment A summary of the health effects of each of the CPCs can be found in
RI and FS Reports (ABB-ES, 1993, 1994a).
Potential human health effects associated with exposure to the CPCS were estimated
quantitatively or qualitatively through the development of several hypothetical
exposure pathways. These pathways were developed to reflect the potential for
exposure to hazardous substances based on the present uses, potential future uses,
and location of the Quarry. Because of curr~nt limited activity at the site, current
exposure scenarios are limited to the evaluation of an older child trespassing. Future
scenarios include adults and children residing at the site, as well as occupational
exposures to a Quarry worker. The following is a brief summary of the exposure
pathways evaluated. A more thorough description can be found in Appendix K of
the RI Report (ABB-ES, 1993)
Under the current trespassing scenario, it was assumed that older children would be
exposed to contaminants in the upper tier through three exposure pathways while
trespassing on the site: 1) ingestion of soil; 2) dermal contact with soil; and 3)
inhalation of fugitive dusts. It was assumed that older children would be exposed to
contaminants in the lower tier through seven exposure pathways while trespassing on
the site: 1) ingestion of soil; 2) dermal contact with soil; 3) inhalation of fugitive
dusts; 4) ingestion of sediment; 5) dermal contact with sediment; 6) ingestion of
surface water; and 7) dermal contact with surface water.
Under the future residential scenario, it was assumed that child and adult residents
would be exposed to contaminants through seven exposure pathways: 1) ingestion of .
soil; 2) dermal contact with soil; 3) inhalation of fugitive dusts; 4) ingestion of
sediment; 5) dermal contact with sediment; 6) ingestion of surface water; and 7)
dermal contact with surface water.
Under the future occupational scenario, it was assumed that a Quarry worker would
be exposed to contaminants through three exposure pathways: 1) ingestion of soil;
2) dermal contact with soil; and 3) inhalation of fugitive dusts.
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SECI'lON 6
In the current land use scenario (older child trespasser), derm~ contact with and
ingestion of surface water was assumed to occur at a frequency of 39 days per year
for 7 years, with an ingestion rate of 100 ml per day and an exposure time of 2 hours
per day. Exposure was also assumed to occur through denpal contact with and
ingestion of sediment at a frequency of 39 days per year for 7 years, with a sediment
ingestion rate of 100 mg per day and a sediment adherence factor of 1.45 mg/cm2.
Exposure was assumed to occur through dermal contact with and ingestion of soil
while trespassing for 117 days per year for 11 years. A soil ingestion rate of 100 mg
of soil per day and a soil adherence factor of 05 mg/ cm2 was assumed. Inhalation
of fugitive dusts while trespassing was assumed to occur 2 hours per day for 117 days
per year for 11 years.
Under the future resident scenario, exposure through ingestion of and dermal contact
with soil was assumed to occur 182 days per year for 6 years for the child resident
and for an additional 24 years for the adult resident, with a soil adherence factor of
05 mgjcm2, and with an ingestion rate of 200 mg per day for the child.and 100 mg
per day for the adult resident. Dermal contact with and ingestion of surface water
was assumed to occur at a frequency of 39 days per year for 6 years for the child
resident and an additional 24 years for the adult, with an ingestion rate of 100
mljdayand a contact exposure time of 2 hours per day. Exposure was also assumed
to occur through dermal contact with and ingestion of sediment at a frequency of 39
days per year for 7 years for the child resident and an additional 24 years for the
adult, with a sediment ingestion rate of 100 mg per day and a sediment adherence
factor of 1.45 mgjc:m? Inhalation of fugitive dusts while in residence was assumed
to occur 16 hours per day for 182 days per year for 6 years for the child and an
additional 24 years for the adult.
Under the future occupational scenario, exposure to the Quarry worker through
ingestion of and dermal contact with soil was assumed to occur for 130 days per year
for one year, with an ingestion rate of 480 mgjday and a soil adherence factor of 05
mgjcm2. Inhalation of fugitive dusts while working at the Quarry site was assumed
to occur 8 hours per day for 130 days per year for 1 year.
For each pathway evaluated, an average and a reasonable maximum exposure (RME)
estimate was generated corresponding to exposure to the average and the maximum
concentration detected in that particular medium.
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SECI'ION 6
Excess lifetime cancer risks were determined for each exposure pathway by
multiplying the exposure level with the chemical specific cancer factor. Cancer
potency factors have been developed by USEP A from epidemiological or animal
studies to reflect a conservative upper bound of the risk posed by potentially
carcinogenic compounds. That is, the true risk is unlikely to be greater than the risk
predicted. The resulting risk estimates are expressed in scientific notation as a
probability (e.g., 1x10-6 for 1/1,000,000) and indicate (using this example), that an
average individual is not likely to have greater that a one in a million chance of
developing cancer over 70 years as a result of site-related exposure as defined to the
compound at the stated concentration. ,Current USEPA practice considers
carcinogenic risks to be additive when assessing exposure to a mixture of hazardous
substances.
The hazard index was also calculated for each pathway as USEP A's measure of the
potential for non-carcinogenic health effects. A hazard quotient is calculated by
dividing the exposure level by the reference dose (RID) or other suitable be]].chmark
for non-carcinogenic health effects for an individual compound. Reference doses
have been developed by USEP A to protect sensitive individuals over the course of
a lifetime and they reflect a daily exposure level that is likely to be without an
appreciable risk of an adverse health effect. RIDs are derived from epidemiological
or animal studies and incorporate uncertainty factors to help ensure that adverse
health effects will not occur. The hazard quotient is often expressed as a single value
(e.g., 03) indicating the ratio of the stated exposure as defined to the reference dose
value (in this example, the exposure as characterized is approximately one third of
an acceptable exposure level for the given compound). The hazard quotient is only
considered additive for compounds that have the same or similar toxic endpoint (e.g.,
the hazard quotient (HQ) for a compound known to produce liver damage should
not be added to a second whose toxic endpoint is kidney damage) and the sum is
referred to as the hazard index (In).
Table 6-1 presents the carcinogenic and noncarcinogenic risk summaries for the
CPCs in soil evaluated for present and potential future risks corresponding to the
average and the RME scenarios for the Upper Tier. Table 6-2 presents the
carcinogenic and noncarcinogenic risk snmmaries for the CPCs in soil, sediment, and
surface water evaluated for present and potential future risks corresponding to the
RME scenarios for the Lower Tier.
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TABLE ~1
TOTAL SITE RISKS FOR EACH RECEPTOR - UPPER TIER
OU 7 RECORD OF DECISION
LORING AIR FORCE BASE
. ... . .
. . '.' . '.' ... '. . , . . . . ... " ..' . ~ASED~~~M~ONci:tnRA110~S ." ...':,.,..'li':."OT'. ..'.'.'..'. ~..,..A.,..,.SC. ..E...'.'._a..D..',.. ..O......N.'...:...',......M...'.:,'.:R'.AX..,.:,'.'..S'.'...lir.M......:...U.,...,..,.".,..M".,.,...:,.'.'.:.,..Cli'..'....OTO..'..'...N...'AC..'.'L".E,:.:..:.NmH"..."AlA'." ..A.......TI.R...OND'...".'..'.'...'NS..,.,.',..O:'..'.:'ex':'.".:.'..:..:..",',.:'.
"",:':":'::'.:: Ft~C~.~(jR:;:.::.::(,::: ::.:::::;::::::;:::.=:::..':.:::,'.:~sO~e.'Rp~'L:'.:::::;, ...'. .:::.TQt~. CA~~. ~!S.!(:,}:J~~.H~qJ~~.: ~ ~'u-.n "
Current Land Use:
Older Child Trespasser
Future Land Use:
Quarry Worker
&:
Child Resident
Adult Resident
Notll:
I
Incidental Ingestion of Soil 2.0E-oS 0.033 1.9E-04 0.069
Dermal Contact with Soil 3.2E-oS 0.0023 3.0E.o4 0.039
Inhalation of Particulates from Soli 5.3E-07 0.000088 1.2E-oa 0.00020
TOTAL: 5.2E-05 0.035 5.0E-04 0.099
Incidental Ingestion of Soli 4.9E-{)6 0.086 5.4E.o5 0.18
Dermal Contact with Soli 6.3E-07 0.00042 6.0E-06 0.0056
Inhalation of Particulates from Soli 3.6E-07 0.00055 2.9E-07 0.0013
TOTAL: 5.8E-OS 0.087 S.OE-05 0.19
Incidental Ingestion of Soli 9.1E-OS 0.21 8.8E-04 0.58
Dermal Contact with Soli 4.4E-oS 0.0059 4.2E-04 0.075
InhalatIon of PartIculates from Soli 2.4E-06 0.0013 5.6E.o6 0.0065
SUBTOTAL Child Resident: 1.4E-04 0.28 1.3E-03 0.88
IncIdental Ingestion of Soli 3.9E-OS 0.029 3.aE-04 0.062
Dermal Contact wIth Soli 2.1 E-oS 0.00071 2.0E-04 0.0090
Inhalation of Particulates from Soli 1.5E-06 0.00012 3.6E-06 0.00027
SUBTOTAL Adult Resident: 8.1E-05 0.030 5.8E-04 0.071
TOTAL Lifetime Resident" 2.0E-04 NA 1.9E-03 NA
Total Ufetlme Resident cancer risk = Subtotal of Child Resident cancer risk + Subtotal of Adult Resident cancer risk.
= Not applicable
NA
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TABLE 8-2
TOTAL SITE RISKS FOR EACH RECEPTOR - LOWER TIER
au 7 RECORD OF DECISION
LORING AIR FORCE BASE
. .. ..
P...::/.. ~~(:~~d~.....P.P ..:i. ......:......~~~~~~:R~:p p
.... .
.. ... .... '. .
.,fqf~~=$ilrK;.jMj~j!:~~~71~:i:~,
Current Land Use:
Older Child Trespasser Incidental Ingestion of Soli 2.0E-oS 0.043 7.2E-oS 0.068
Dermal Contact with Soli 3.0E-oS 0.0018 1.1E-04 0.0061
Inhalation of Particulates from Soli 3.8E-08 0.00011 1.4E-D7 0.00017
Sediment Ingestion 2.9E-06 0.013 4.5E-06 0.045
Dermal Contact with Sediment 1.1E-oS 0.0016 1.SE-oS 0.00S9
Surface Water Ingestion 4.6E-09 0.0052 1.5E-08 0.01S
Dermal Contact with Surface Water 4.6E-10 0.00051 l.5E-D9 0.0015
TOTAL: 8.4E-05 0.085 2.0E-04 0.14
0\
I
0\
Future Land Use:
Quarry Worker
Child Resident
w0089412T.1/8
Incidental Ingestion of Soli S.SE-06 0.13 2.0E-oS 0.20
Dermal Contact with 5011 6.0E-07 0.00022 2.2E-06 0.00078
Inhalation of Particulates from Soli 2.9E-08 0.00081 1.0E-07 0.0013
TOTAL: 8.1 E-08 0.13 2.2E-05 0.20
Incidental Ingestion of Soil 9.0E-05 0.36 3.2E-04 0.56
Dermal Contact with Soli 4.2E-oS 0.0044 1.5E-04 0.015
Inhalation of Particulates from Soli 1.9E-07 0.00092 6.9E-07 0.0014
Sediment Ingestion 2.5E-06 0.013 3.9E-06 0.045
Dermal Contact with Sediment 9.2E-06 0.0016 1.3E-05 0.0059
Surface Water Ingestion 4.0E-09 0.0052 1.3E-D8 0.015
Dermal Contact with Surface Water 3.9E-10 0.000S1 1.3E-09 0.0015
-------
(continued)
TABLE 8-2
TOTAL SITE RISKS FOR EACH RECEPTOR - LOWER TIER
'.
au 7 RECORD OF DECISION
LORING AIR FORCE BASE
. .
.. /~~Cj:PtoR ..
Adult Resident
..
.. ..
..... ". ..::..:~~s~ft~.RQUit:
IncIdental Ingestion of Soli
Dermal Contact with Soli
InhalatIon of Particulates from Soli
SedIment IngestIon
Dermal Contact with Sediment
Surface Water Ingestion
Dermal Contact with Surface Water
SUBTOTAL AduH Resident:
..:'.. .:.::.t.~~:~~:~~::.~.!~::~~~,~~~.:;
3.9E-oS 0.038
2.0E-oS 0.00053
1.2E-07 0.00015
4.4E-oS 0.0056
2.4E-oS 0.0011
7.0E-09 0.0023
1.0E-10 0.00033
1.7E-OS 0.048
'.
0\
,
.....,
TOTAL Lifetime Resldentll
ID'.:
.
NA
2.3E-04
Total Uletlme Resident cancer risk. Subtotal 01 Child Resident cancer risk + Subtotal of Adult Resident cancer risk.
.. Not applicable
WOO89412T.1/9
.:.i.i6t~~M~~~~~~..~:;~;;~:1:g~:::
1.4E-04 0.060
7.3E-D5 0.0018
4.4E-D7 0.00023
6.9E-D6 0.020
3.3E-05 0.0038
2.0E-oe 0.0066
2.3E-D9 0.00095
2.5E-04 0.093
NA
7.4E-04
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SECI10N 6
6.1.1 Upper Tier
Carcinogenic and noncarcinogenic risks to human health in upper tier are discussed
below.
Carcinogenic Risks. Table 6-1 presents cancer risk estimates for the upper tier soil
exposure scenarios. Based on mean contaminant concentrations, the total cancer risk
associated with soil exposures exceeds the USEPA target risk range (1xlQ4 to lx1~)
only for future lifetime residential scenario (2.Ox1
-------
SEcrION 6
estimates related to exposures based on both mean and maxim~ concentrations for
the future lifetime resident (2.3x104 and 7.4xl04, respectively) and the child resident
scenario (l.4xlQ4 and 4.9xlQ4, respectively) Cancer risks associated with all current
and potential future residential, occupational, and recreational ~osures also exceed
the MEDEP cancer risk guidance value of lxlo-5 except for the Quarry worker
exposed to mean concentrations in soil (6.lxl
-------
SECI'lON 6
Aquatic organisms (e.g., fish, amphibians, and aquatic invertebr~tes) in the wetland
and drainage channel associated with the Quany and in the Greenlaw Brook wetland
may be exposed to chemicals in waters or sediment through direct contact and
incidental ingestion. Selection of potential aquatic receptQrs and modeling of
exposure to aquatic organisms was not necessaIy because the reported concentrations
of CPCs in surface water and sediment represent exposure concentrations for aquatic
organisms that may be directly compared to water quality criteria.
No exposure pathways were identified for groundwater or subsurface soil at the site
because terrestrial organism do not come into. contact with subsurface media and no
prey exist in subsurface areas.
The results of the baseline ecological RA indicate that terrestrial receptors are at
risk from exposure to contaminants in surface soils. .
6.2.1 Upper TIer
In the upper tier area, both acute and chronic HI values for the shrew are above 1
(9.7 and 75, respectively). The Aroclors, antimony, benzo(a)pyrene, and DDTjDDE
are the greatest contributors to the chronic HI, while lead, selenium, antimony, and
barium are the significant contributors to the acute m. Of the five indicator species,
only the shrew has III values that are. of concern.
6.2.2 Lower TIer
In the lower tier area, the acute HI values for the shrew, the sparrow, and the hawk
were above 10 (ranging from 11 to 290). The chronic m values are above 1 for all
indicator species except the fisher and hawk. The chronic values range from 0.0041
to 2,100. Benzo(a)pyrene is the largest contributor for all five indicator species.
Dibenz( a,h)anthracene, antimony, barium, selenium, and lead also contribute
significantly to the values in the lower tier.
Risks to aquatic receptors are predicted because of reported concentrations of
inorganics in surface water and sediment associated with the Greenlaw Brook
wetland and drainage ditch. P AHs detected in sediment exceed USEP A Sediment
Quality Criteria and may therefore impact aquatic receptors based on the data
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SECTION 6
collected to date. Aroc1or-1260 may also be contributing to ~k, although this
contaminant was detected in only one of 13 samples.
Based on the scenario in which soil in the lower tier was evalua~d as sediment, risks
to aquatic receptors could be expected from potential exposure to sediment.
Anthracene and fluorene presented the greatest potential risks with chemical-specific
HQs of 88. and 140, respectively. Other PAHs and antimony may also be
contributing to risks. Risks due to VOCs, barium, and selenium detected in the
lower tier could not be evaluated because reference toxicity values (RTVs) are not
available.
6.3 UNCERTAINTY EvALUATION
Quantitative estimates of risk are based on numerous assumptions, most of which are
intended to be protective of human health (i.e., conservative). The interpretation of
risk estimates is subject to a number of uncertainties as a result of the multiple layers
of conservative assumptions inherent in Ras. As such, risk estimates are not truly
probabilistic estimates of risk, but are conditional estimates, given a series of
conservative assumptions about exposure and toxicity. While it is true that there are
some uncenainties inherent in the RA methodology that might lead to an
underestimation of true risks, most assumptions will bias the evaluation in the
direction of overestimation of risk.
The possibility of underestimation of true risks may be caused by the exclusion from
quantitative evaluation of pathways (i.e., ingestion of homegrown produce from
backyard garden plots) or through the exclusion of compounds from the RA through
the toxicity screening procedure. However, the toxicity screening procedure
evaluated compounds that covered more than 99 percent of the risk; therefore it is
unlikely that the risks will be underestimated by a substantial amount.
Because benzo(a)pyrene and naphthalene are the most toxic representatives of
carcinogenic and noncarcinogenic P AHs, respectively, use of their toxicity values will
likely result in overestimation of risks. Other sources of uncertainty that could cause
overestimation of risks include the use of purposive (biased) sampling (targeting "hot
spots" or visible CODtamination); the estimation of exposure concentrations by the use
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SECl'ION 6
of maximum detections (while assuming no degradation or diluuon); the use of the
95 percent (or upper-bound 90 percent) exposure parameter values such as contact
rate and exposure frequency and duration; the use of conservatively derived toxicity
values such as RIDs (incorporating multiple safety factors) and cancer slope factors
(CSFs), which are based on experimental animal data used in a multistage model.
The USEPA Risk Assessment Guidance (USEPA, 1989a,b) states that the
carcinogenic risk estimate will generally be an upper-bound estimate, and the
USEP A is reasonably confident that the "true risk" will not exceed the risk estimate
derived through the use of this model and is likely to be less than predicted.
Therefore, the true risk is likely not much more than the estimated risk, but could
very well be considerably lower, even approaching zero.
6.4 CONCLUSION
Actual or threatened releases of hazardous substances from this site, if not addressed
by implementing the response action selected in this ROD, may present an imminent
and substantial endangerment to public health, welfare, or the environment. The
objective of the selected remedial action is to excavate upper and lower tier soil and
drainage ditch sediment, and its placement as subgrade material at the OU 2
landfills. Through this action, exposures to the contamin~nts in soil and sediment at
the Quarry will be e1iminated.
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SECTION 7
7.0 DEVELOPMENT AND SCREENING OF ALTERNATIVES
Four alternatives were developed and screened in the FS. ~ section descnbes the
response objectives and the development and screening of alternatives.
7.1 STATUTORY REQmREMENTS/RESpONS~ OBJECl1VES
Under its legal authorities, the USAF's primary responsibility at Superfund sites is
to undertake remedial actions that are protective of human health and the
environment. In addition, Section 121 of CERCLA establishes several other
statutory requirements and preferences, including: a requirement that the USAF's
remedial action, when complete, must comply with all federal and more stringent
state environmental standards, requirements, criteria or limitations, unless a waiver
is granted; a requirement that the USAF select a remedial action that is
cost-effective and that utilizes permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum extent practicable;
and a preference for remedies in which treatment which permanently and
significantly reduces the volume, toxicity or mobility of the hazardous substances is
a principal element over remedies not involving such treatment. Response
alternatives were developed to be consistent with these Congressional mandates.
Based on preliminary information relating to types of contaminants, environmental
media of concern, and potential exposure pathways, remedial action objectives were
developed to aid in the development and screening of alternatives. Tbese remedial
action objectives were developed to mitigate existing and future potential threats to.
public health and the environment. These response objectives were:
.
to prevent ingestion of and dermal contact with soil by human and
ecological receptors.
.
to minimize migration of soil contaminants to groundwater.
.
to minimize migration of soil contaminants to adjacent surface waters
and sediment.
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SECI'lON 7
7.2 TECHNOLOGY AND ALTERNATIVE DEVELOPMENT AND SCREENING
CERClA and the National Contingency Plan (NCP) set forth the process by which
remedial actions are evaluated and selected. In accordance wi~ these requirements,
a range of alternatives were developed for the site.
With respect to source control, the FS developed a range of alternatives in which
treatment that reduces the toxicity, mobility, or volume of the hazardous substances
is a principal element. This range included an alternative that removes or destroys
hazardous substances to the maximum extent. feasible, eliminating or minimi7iTlg to
the degree possible the need for long-term management. This range also included
alternatives that treat the principal threats posed by the site but vary in the degree
of treatment employed and the quantities and characteristics of the treatment
residuals and untreated waste that must be managed; alternative(s) that involve little
or no treatment but provide protection through engineering or institutional controls;
and a no action alternative.
In summary, of the eight source control remedial alternatives screened in Section 6
of the FS, four were retained for detailed analysis. Tables 7-2 through 7-9 in the FS
identify the fom alternatives that were retained through the screening process, as well
as those that were eliminated from further consideration.
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SECI10N 8
8.0 DESCRIPTION OF ALTERNATIVES
This section provides a narrative Sl1mmary of each alternative eyaluated The source
control alternatives analyzed for the au 7 include a Minimal No Action Alternative
(Alternative 1), Containment Using a Cover System (Alternative 2), Excavation with
On-site Asphalt Batching (Alternative 3), and Excavation and Use as Subgrade
Material for On-base Landfill Cap Construction (Alternative 4). Detailed
assessments of each alternative can be found in Section 8 of the FS Report (ABB-ES,
1994a).
8.1 MINIMAL No-ACTION
The minima] no-action alternative (Alternative 1 in the FS) is required by the NCP,
and provides a baseline against which other alternatives can be compared. This
alternative would consist of the following components:
.
.
environmental monitoring
five-year site reviews
access and deed restrictions
.
Estimated Time for Design and Construction: 5 months
Estimated Time of Operation: 30 years
Estimated Capital Cost: $114,000
Estimated Operation and Maintenance Costs (net present worth): $814,000
Estimated Total Cost (net present worth): $928,000
8~ COVER SYSTEM
This alternative (Alternative 2 in the FS) consists of the following components:
.
site preparation;
excavation of lower tier soil and drainage ditch sediment;
cover installation;
.
.
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SECI10N 8
.
wetlands restoration of the lower tier;
post-closure maintenance;
access and deed restrictions;
environmental monitoring, and;
five-year site reviews.
.
.
.
.
Estimated Time for Design and Construction: 2 years
Estimated Time of Operation: 30 years
Estimated Capital Cost: $1.39 million
Estimated Operation and Maintenance Costs (net present worth): $956,000
Estimated Total Cost (net present worth): $234 million.
8.3 ON-SITE SOIL INCLUSION IN EMULSIFIED AsPHALT (ASPHALT BATCHING)
This alternative (Alternative 3 in the FS) includes the following components:
.
site preparation;
excavation of lower and upper tier soil and drainage ditch sediment;
asphalt batching;
off-base disposal of rejected materials;
wetlands restoration of the lower tier; .
environmental monitoring, and;
five-year site reviews.
.
.
.
.
.
.
Estimated Time for Design and Construction: 1.5 years
Estimated Time of Operation: 30 years
Estimated Capital Cost: $7.01 million
Estimated Operation and Maintenance Costs (net present worth): $576,000
Estimated Total Cost (net present worth): $7.59 million
W009943UI80
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SECTION 8
8.4
EXCAVATION AND USE AS SUBGRADE MATERIAL FOR ON-BASE LANDFILL CAP
CON~UcnON .
This alternative (Alternative 4 in the FS) includes the follo~g major components:.
.
site preparation;
excavation of lower and upper tier soil and drainage ditch sediment;
use as subgrade material for on-base landfill cap construction;
wetlands restoration of the lower tier;
environmental monitoring, and;
five-year site reviews.
.
.
.
.
.
Estimated Time for Design and Construction: 9 months
Estimated Time of Operation: 30 years
Estimated Capital Cost: $127 million
Estimated Operation and Maintenance Costs (net present worth): $576,000
Estimated Total Cost (net present worth): $1.85 million
Estimated Time for Design and Contracting: 3 months
Estimated Time for Construction: 3 months
'.;
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SECI'ION 9
9.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
Section 121(b)(1) of CERaA presents several factors that at a IIrinimum the USAF
is required to consider in its assessment of alternatives. BuildiIig upon these specific
statutory mandates, the NCP articulates nine evaluation criteria to b~ used in
assessing the individual remedial alternatives.
9.1 EVALUATION CRITERIA USED FOR DETAnED ANALYSIS
A detailed analysis was performed on the alternatives using the nine evaluation
criteria in order to select a site remedy. Section 9.2 contains a summary of the
comparison of each alternative's strength and weakness with respect to the nine
evaluation criteria. These criteria are snmmarized in Section 9.1.1.
9.1.1 Threshold Criteria
The two threshold criteria described below must be met in order for the alternatives
to be eligible for selection in accordance with the NCP.
.
Overall protection of human health and the environment addresses
whether or not a remedy provides adequate protection and describes
how risks posed through each pathway are eliminated, reduced or
controlled through treatment, engineering controls, or institutional
controls.
.
Compliance with applicable or relevant and appropriate requirements
(ARARs) addresses whether or not a remedy will meet all of the
ARARs of other Federal and State environmental laws and/or provide
grounds for invoking a waiver.
9.1.2 Primary Balancing Criteria
The following five criteria are utilized to compare and evaluate the elements of one
alternative to another that meet the threshold criteria.
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SECTION 9
.
Long-term effectiveness and permanence addresses .the criteria th;at are
utilized to assess alternatives for the long-term effectiveness and
permanence they afford, along with the degree of certainty that they
will prove successful.
.
Reduction of toxicity, mobility, or volume through treatment addresses
the degree to which alternatives employ recycling or treatment: that
reduces toxicity, mobility, or volume, including how treatment is used
to address the principal threats posed by the site. .
.
Short-term effectiveness addresses the period of time needed to
achieve protection and any adverse impacts on human health and the
environment that may be posed during the construction and
implementation period, until cleanup goals are achieved.
.
Implementability addresses the technical and administtative feasibility
of a remedy, including the availability of materials and services needed
to implement a particular option.
.
Cost includes estimated capital costs (indirect and direct) and annual
operation & maintenance (O&M) costs, as well as present-worth costs.
9.1.3 Modifying Criteria
The modifying criteria are used on the final evaluation of remedial alternatives
generally after the USAF has received public comment on the RIfFS and Proposed
Plan.
.
.
State acceptance addresses the state's position and key concerns
related to the preferred alternative and other alternatives, and the
state's comments on ARARs or the proposed use of waivers.
Community acceptance addresses the public's general response to the
alternatives described in the Proposed Plan and RIfFS repott.
W0099431.080
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SECI'ION 9
9.2 SUMMARY OF COMPARATIVE ANALYSIS
Following the detailed analysis of each individual alternative, a comparative analysis,
focusing on the relative performance of each alternative agains~ the nine criteria, was
conducted. The following subsections present the nine criteria and a brief narrative
SUIIlI11ary of the alternatives and the strengths and weaknesses according to the
detailed and comparative analysis. A detailed tabular assessment of each alternative
according to the nine criteria can be found in Table 9-1 of the FS (ABB-ES, 1994a).
9.2.1 Overall Protection of Human Health a.nd the Environment
The excavation and use as subgrade material alternative, would be protective of
human health and the environment because removal of the contaminated soil and
sediment from the site and its use as a landfill cap subgrade material eliminates
direct contact, windbome migration, and incidental ingestion of soil, and sediment
by humans and animals. The cover system alternative is estimated to reduce
99 percent of the infiltration leading to continued contamination of groundwater.
The cover system would also be designed to minimize erosion. Asphalt batching
would prevent migration of the soil contaminants to groundwater and surface water
because contaminants would be removed from the site and treated.
The minimal no-action alternative would not include measures which would protect
human bealth or the environment.
9.2.2 Compliance with Applicable or Relevant and Appropriate Requirements
Alternatives 2, 3, and 4 would be designed to comply with the state and federal
ARARs. The minima 1 no-action alternative would not meet the applicable ARARs.
ARARs for the selected alternative are discussed in more detail in Section 11.
9.2.3 Long-term Effectiveness and Permanence
The excavation and use as subgrade material alternative would provide long-term
effectiveness because contaminated soils would be removed from the site and
contained within a well-maintained cover system. Once cap construction is complete,
migration of cont$lm1Ttants and access to soil would be reduced. Potential for
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SECfION 9
migration and erosion of contaminated soil from upper and l~wer tiers would be
greatly reduced with the conclusion of excavation activities.
The cover system alternative relies on cOntainment to control ipfiltration and erosion
of the contaminated soil. The deed restrictions and post-closure program would
maintain cover system integrity over the long-term, and groundwater monitoring
would provide data to evaluate the effectiveness of the cover system for minimi7.ing
groundwater contamination.
Asphalt batching would use treatment to .immobilize soil contaminants. The
contamination would be permanently incorporated in the asphalt emulsion. The
minimal no-action alternative does not include remedial actions, and therefore
provides no mechanism to reduce unacceptable risks from soil and sediment
contamination.
9.2.4 Reduction of Mobility, Toxicity, or Volume through Treatment
The asphalt batching alternative would reduce mobility through treatment of source
area contaminants. The excavation and use as subgrade material alternative, cover
system alternative, and minimal no-action alternative do not propose reduction
through treatment However, the excavation and use as subgrade material alternative
and cover system would reduce mobility through containment, and would reduce
rainwater infiltration, erosion, and direct contact with the contaminated soil.
9.2.5 Short-term Effectiveness
The minimal no-action alternative would not include any effects on the community,
because remedial actions would not be required. . Workers conducting environmental
monitoring would require specialized health and safety training. Alternatives 2, 3,
and 4 would also require health and safety training for workers who operate the
excavation equipment and conduct monitoring. Adverse effects on workers are not
anticipated as long as safe working practices are followed. Adverse effects on the
community would not be expected as a result of construction and operation of these
alternatives. The three remedial action alternatives would impact ecological
receptors during excavation activities in the lower tier wetland. The wetland would
be restored with wetland of equal or greater value and size in accordance with state
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SECTION 9
and federal regulations. The permanent reduction of impact on ~e Greenlaw Brook
wetland outweighs the short-term adverse impacts from the loss of the Quarry
wetland. Vegetation would be established on the upper tier with the cover system
.alternative, however, with the proposed and asphalt batching a).tematives, vegetation
would not be reestablished, thus reducing the overall habitat value of the site.
9.2.6 Implementability
. Installation of the excavation and use as subgrade material alternative, cover system
alternative, and the asphalt batching alte~ative involves easily implementable,
reliable, and available technologies. The minimal no-action alternative does not
include remedial actions.
9.2.7 Cost
The cost criterion includes the capital (Le., up-front) cost of implementing an
alternative, as well as the cost of operating and maintaining the alternative over the
long term. The estimated total cost on a present-worth basis considers both up-front
capital costs and long-term operation and maintenance costs. The capital, O&M, and
total costs for each alternative are presented in Section 8 of the FS.
9.2.8 State Acceptance
As party to the FF A, MEDEP has provided comments on the FS and Proposed Plan,
and has documented its concurrence with the remedial action as stated in Section 13
of this ROD. A copy of the MEDEP's letter of concurrence is presented in
Appendix C of this ROD.
9.2.9 Community Acceptance
Community acceptance of the Proposed Plan was evaluated based on comments
received at public meetings and during the public comment period. This is
documented in the Transcript of the Public Meeting in Appendix A, and in the
Responsiveness Summary in Appendix B of this ROD. .
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SEcrION 10
10.0 THE SELECfED REMEDY
The selected remedy for au 7 is Alternative 4 of the FS, consisting of excavating the
Quany Site and using the excavated material as subgrade fill for on-base landfill cap
construction. The remedial action is a final source control remedy for the
contaminated soils and sediments at OU 7. au 7 groundwater will be addressed in
the basewide groundwater operable unit (OU 12) and Quarry Site wetlands and the
adjacent Greenlaw Brook wetlands will be addressed in the basewide surface water
and sediment operable unit (OU 13). .
10.1 CLEANUP LEvELS
The USAF has established, with concurrence of the regulatory agencies, site-specific
remediation goals that will be protective of human health and the environment.
Cleanup goals have been set for contaminated soil and sediment based either on
background concentrations, on analytical detection limits, or on risk calculations.
Compounds for which remediation goals have been set are listed in Tables 10-1 and
10-2 for the lower and upper tiers, respectively.
10.2 DESCRImON OF REMEDIAL COMPONENTS
The following paragraphs describe the remedial alternative the USAF developed for
the Quarry Site: Excavation and Use as Subgrade Material for On-base Landfill Cap
Construction. Implementation of the selected alternative would include the following
activities:
.
site preparation;
excavation of lower and upper tier soil and drainage ditch sediment;
use as subgrade material for on-base landfill cap construction;
wetlands restoration of the lower tier;
environmental monitoring, and;
five-year site reviews.
.
.
.
.
.
Installation Restoration Program
W0099431.080
10-1
-------
TABLE 10-1
PREUMINARY REMEDIATION GOALS FOR loWER TIER SOIL *
au 7 RECORD OF DECISION
loRING AIR FORCE BASE
CHEMICAL .
...
. .
SOIL TARGET CLEANUP LEva....
... ..... ... . t"'9/kg) . .. .
BASIS. .
SVOCs
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Dibenz(a,h)anthracene
Chrysene
Indeno(1,2,3-cd)pyrene
Pesticides/PCBs
4,4' -DDD
4,4' -DDT
Inoraanics
Antimony
Barium
Lead
Selenium
0.33
0.33
0.33
0.33
0.33
0.33
0.33
Detection Umit
Detection Umit
Detection Umit
Detection Umit
Detection Umit
Detection Umit
Detection Umit
0.064
0.089
Background Value
Background Value
12
130
35
1.0
Detection Umit
Background Value
Background Value
Detection Umit
Note:
a Based on risk calculations, analytical method detection limits, or LAFB soil background values.
.~il includes drainage ditch lediment
WOO89412T.1/10
-------
TABLE 1~2
PREUMINARV REMEDIATION GOALS FOR UPPER TIER SOIL
au 7 RECORD OF DECISION
loRING AIR FORCE BASE
... .
cHaftCAL ....
. BASIS.
SVOCs
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Chrysene
Indeno(1.2,3-cd)pyrene
Pesticides/PCBs
Aroelor-1248
Aroelor-1254
4,4'-000
4.4' -DDT
aJpha-Chlordane
gamma-Chlordane
Inoraanics
Antimony
Chromium
Note:
..' .
. . .
.. .....p .
...SOILTAR~(~g~~
0.33
0.33
0.33
0.33
Detection Umit
Detection Umit
Detection Umit
Detection Umit
0.33
0.33
Detection Umit
Detection Umit
0.033 Detection Umit
0.033 Detection Umit
0.16 Risk Calculation
0.16 Risk Calculation
0.032 Risk Calculation
0.032 Risk Calculation
12
60
Detection Umit
Background Value
a Based OD rUt calculationa, analytical method detec:lion limits, or LAFB lOil bac:tpxmd values.
WtI089412T.1/11
\
-------
SECI10N 10
The components are described in the following paragraphs.
Site Preparation. A O.5-acre area would be graded near the Quarry to stage
excavation equipment, establish a decontamination area, and ;mobilize a temporary
field office. Existing access roads to the Quarry would be upgraded to accommodate
the increase in vehicle traffic and the weight of vehicles carrying soil and equipment.
Approximately 15,000 cubic yards (cy) of construction debris (i.e., concrete and
rebar) currently located in the upper tier would be removed and used as subgrade
material for the au 2 Landfills.
Excavation of Lower and Upper TIer Quarry Soil and Drainage Ditch Sediment. A
total of approximately 28,000 cy of soil would be excavated for use as subgrade
material for cap construction at the au 2 Landfills. The depth of soil in the lower
tier ranges from approximately 1 to 4 feet bgs. The depth of soil in the upper tier
ranges from 1 to approximately 15 feet bgs. It was assumed the depth of sediment
in the drainage ditch averages approximately 2 feet bgs~
Confirmatory soil and sediment samples would be collected during excavation to
confirm that the soil which exceeds preJiminary remediation goals (PRGs), and which
can be removed, has been excavated. At some locations, the limits of excavation
would extend to existing bedrock sidewalls, and confirmation sampling would not be
required. If analytical results of the confirmatory samples indicate that the soil
exceeding PRGs has not been removed, the limits of excavation will be extended
until the soil exceeding PRGs can be removed and has been excavated, or until the
excavation equipment reaches bedrock.
The ease of removing the lower tier soil and drainage ditch sediment will depend on
the variability of the rock surface under the area and the elevation of the
groundwater table. The rock surface may have pockets and knobs, and may contain
cracks and crevices. These features would retain some soil and sediment not easily
reachable by excavation equipment If remediation activities occur during a wet time
of year, the groundwater table may be within the soil layer. This would result in the
presence of water in the bottom of the excavation as soil is removed. If soil
excavation is performed below groundwater leve~ the activity would suspend the finer
soils in the water, and would make total removal of the soil difficult. Sump pumps
would be used in this case to divert water away from the excavation area.
Installation Restoration Program
W0099431.080
10-4
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SECTION 10
Use as Subgrade Material for On-base Landfill Cap Construction. Excavated soil
would be loaded onto dump ttucks and transported to OU 2. The transport distance
from the Quarry to OU 2 is approximately 2.5 miles, one way (Figure 10-1).
The landfills at OU 2 (Le., Landfills 2 and 3), inactive facilities scheduled for capping
and closure within the year, currently contain temporary soil covers. Surface
depressions in the temporary cover of each landfill require fill material to create a
subgrade suitable for capping. Use of the excavated soil from the Quany would help
meet the need for a large quantity (between 400,000 and 600,000 cy) of imported fill
required to meet subgrade design specifications at OU 2. The proposed landfill cap
currently being considered for OU 2 will be designed and constructed to be
consistent with Resource Conservation and Recovery Act (RCRA) (42 U.S.C. ~901)
Subtitle C requirements. This proposed cap is the subject of a separate CERClA
ROD which is expected to be issued concurrently with this au 7 ROD. Soil from
other remedial actions at LAFB (e.g., OU 6 site soils), with public acceptance, and
after compliance with CERCLA and the NCP, would also be brought in for use as
subgrade material. These soils will be segregated within the landfill in which they
are used. Oean fill will be placed over the soils from the Quany and other operable
unit remedial actions to achieve final subgrade elevations for the landfill cap.
Before material from other areas at Loring Air Force Base can be used as subgrade
material at OU 2, the Air Force must issue an OU 2 ROD which permits such use.
In addition, the Air Force must evaluate the material from these areas to determine
if the material is hazardous and subject to the RCRA Land Disposal Restrictions
(!DR), 4 CFR Par. 268, and must demonstrate that it has complied with the
procedures set forth in the "Technical Memorandum - A Land Disposal Restriction
Evaluation of Soils Proposed as Landfill Subgrade Materials, July, 1994" (LDR
Technical Memorandum). If the material is non-hazardous, it may be used for
subgrade fill at OU 2. H it is determined to be hazardous, it may not be used for
subgrade fill at OU 2 unless it is treated in accordance with the !DR requirements
prior to use as subgrade fill. The soils and sediments from OU 7 have been sampled
and analyzed and determined to be non-hazardous. Therefore, the requirements of
the LDR Technical Memorandum have been met. See discussion in Section 112
below.
Installation Restoration Program
W0099431.080
10-5
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G)
Caswell
Connor
LORING AIR FORCE BASE
Limestone
.: Caribou
----- TOWNUNE
OU 2.. LANDFILLS 2 AND 3
OU 7 - QUARRY SITE
LORING AIR
FORCE BASE
FIGURE 10-1
LOCATION OF QUARRY
AND OU 2 LANDFILLS
I
o
SCALE I N FEET
.
4000
I
8000
LORING AIR FORCE BASE
UMESTONE. MAINE
94080030(a)
-------
SECTION 10
Wetlands RestoratioD. As part of IRP activities at lAFB, wetland areas located on
the base which potentially could be impacted by remediation are" being evaluated as
part of au 13. This evaluation will include an assessment of the approach and
location for restoring wetlands affected by remedial activities (e.g., the total acreage
of LAFB wetlands affected by remedial activities may be replaced by creating one
new wetland in an alternate location). Therefore, the final approach to wetland
restoration for the entire base, including the wetland located in the lower tier of the
Quarry, will be evaluated as part of au 13. The wetland restoration program
described in the FS is included in the cost of Alternative 4; however, the location
where the wetland will be restored will be" evaluated on a basewide basis (i.e.,
au 13).. The wetlands lost through the remedial action will be replaced with
wetlands equal to or greater than the size and value of the affected wetlands.
The excavated wetland area would be restored according to a wetland restoration
specification (WRS) because remedial activities at the Quarry Site would result in
the destruction of the emergent marsh in the lower tier and drainage ditch.
Restoration of wetlands for the Quarry Site would reduce the long-term impacts of
excavation activities in and adjacent to the wetlands, compensate for losses of
wetland habitats, restore or enhance degraded wetlands, and meet state and federal
requirements. If wetlands are restored at the Quarry, wetland restoration would
include backfilling the excavated area with suitable material, establishing planting
and performance criteria, monitoring for successful regeneration, and controlling
erosion and siltation.
Environmental Monitoring. The environmental monitoring prograri1 would include
three sampling programs: (1) groundwater; (2) biological media in Greenlaw Brook
wetland; and (3) restored wetlands. These sampling programs would evaluate
whether the Quarry Site is a source of contamination to the Greenlaw Brook
wetland, the Quarry Site's potential future impact on groundwater and groundwater
potential impact on the Quarry Site after completion of this Remedial Action.
Groundwater monitoring would involve routine, periodic sampling of groundwater
for five years after implementation of the alternative. If laboratory results indicate
that groundwater quality or the remediation of the lower Quarry has been negatively
impacted, additional groundwater monitoring and remediation, if necessary, would
be conducted under the basewide groundwater operable unit, au 12. Biomonitoring
would consist of an initial screening program that would involve a one-time sampling
Installation Restoration Program
W0099431.1JSO
10-7
-------
SECl10N 1..
of Greenlaw Brook wetland biota and biological tissue. Based on information
obtained from this initial screeIring program, the need for a IOI1g~term biomonitoring
program would be evaluated. The wetlands restoration monitoring would assess the
progress of the lower tier wetland area restoration.
Five-year Site Reviews. To the extent required by law, the USAF will review the
Quarry Site monitoring program at least once every five years in accordance with
applicable USEP A guidance after the initiation of remedial action to assure that the
remedial action continues to protect human health and the environment, assessing
site conditions and proposing further actions,. if necessary.
Installation Restoration Program
W0099431.080
10-8
-------
SECI10N 11
11.0 STATUTORY DETERMINATIONS
The remedial action selected for implementation at OU 7 is consistent witb
CERClA and, to the extent practicable, the NCP. The selected remedy is protective.
of human bealth and the environment, attains ARARs, and is cost effective. This
remedy uses permanent solutions and alternative treatment technologies to the
maximum extent practicable. The selected remedy does not, however, satisfy the
statutory preference for remedies that employ treatment that reduces toxicity,
mobility, or volume as a principal element The selected remedy will reduce mobility
through containment and will reduce mobility of contaminants through the
containment features of the landfill cover system at OU 2, which will also reduce
rainwater infiltration, erosion, and direct contact with the contaminated soil.
11.1
THE SELECTED REMEDY IS PROTECl'IVE OF HUMAN HEALTH AND THE
ENVIRONMENT
The remedy at au 7 will permanently reduce the risks posed to human health and
the environment by eliminating, reducing or controlling exposures to human and
environmental receptors through engineering controls and institutional controls. The
removal of the cont;tmin;tted soil from the site and its use as a landfill cap subgrade
material eliminates direct contact, windbome migration, and incidental ingestion of
soil, sediment, and surface water by humans and animals.
Moreover, the selected remedy will achieve potential human health risk levels that
attain the lQ4 to 1Q-6 incremental cancer risk range and a level protective of
noncarcinogenic endpoints.
11.2 THE SELECTED REMEDY ATI'AlNS ARARs
The selected remedy will attain all federal and state ARARs that apply to au 7.
Tables 11-1 through 11-3 to this ROD presents a tabular summary of the chemical,
location and action-specific ARARs for the selected remedy, including the regulatory
citation, a brief summary of the requirement, and how it will be attained.
Installation Restoration Program
W0099431.080
11-1
-------
TABLE 11-1
CHEMICAL-SPECIFIC ARARs. CRITERIA, ADVISORIES. OR GUIDANCE
au 7 ReCORD OF DeCISION
LORING AIR FORCE BASE
. REQUIREMi:tfT
.:.~~fJt("'QBet~K~ t9 ATIA'~ ~~QOIREMENTS .
MEDIA...
WASTE MATERIAL
ReRA Identification
and Listing of
Hazardous Wastes
(40 CFR Part 261)
......
......
I
tV
ReRA land
Disposal
Restrictions (LDRs)
(40 CFR Part 268)
..
. STATUS
fi~9tJI~~~ijt S'iND.r,IS .
Analytical results were evaluated agftlnst the.
criteria and the definitions of hazardous waste.
These regulations may be referred to and
utilized when developing remedial alternative
and during remedial actions.
Waste materials from separate Qperable units
will be evaluated to determine whether the
waste Is hazardous. If so, the materials will not
be placed under the au 2 cover system I or
will be treated In accordance with LDRs prior
. to disposal at au 2.
. Nat..:
CFR Code of Federal Regulations
LDRs . Land Disposal Restrictions
RCRA = Resource Conservation and Recovery Act
WD089412T.1/12
Relevant and These requirements define those wastes that are
Appropriate subject to regulation as hazardous wastes under
RCRA.
Relevant and
Appropriate
land disposal of ReRA hazardous waste Is
restricted without specified treatment. For the LDRs
to be applicable, It must be determined that the
waste meets the definition of one of the specified
restricted wastes and remedial action constitutes
placement. For each hazardous waste, the LDRs
specify that the waste must be treated either by a
treatment technology or to a concentration level
prior to disposal In a RCRA Subtitle C permitted
-------
TABLE 11-2
loCATION-SPECIFIC ARARs, CRITERIA, ADVISORIES, OR GUIDANCE
OU 7 RECORD OF DECISION
LORING AIR FORCE BASE
. ".. .
.. .... . .
.:::i:NfEP'!A:. .:
WETLANDS
Federal
~
....
,
(N
.. ...... .. ... .. ..... .
"". ..::::\:t::F.t~.9Yi"~M"ff.t\
: .\:.TAW,-::.::\rt:.:::::::..;::::..:::::.::.::::::;.:::::::;::-:ft~94i."IM,~:.$iffll,j",::::.. .
Clean Water Act (CWA)
Section 404(b)(l)
Guidelines for
Specification of
Disposal Sites for
Dredged or Fill
Materials
(40 CFR Part 230)
Fish and Wildlife
Coordination Act
(16 USC 661 et sea.)
Applicable
Applicable
40 CFR Part 230 contains requirements for
discharge of dredged or fill material, Including
that no discharge will be permitted If there Is a
practicable alternative to the proposed
discharge which would have less adverse
Impact to the aquatic ecosystem, and that no
discharge Is permitted unless appropriate and
practicable steps are taken to minimize
potential adverse Impacts on the aquatic
ecosystem.
This act requires federal agencies to take Into
consideration the effect that water-related
projects will have upon fish and wildlife. This
act requires consultation with the U.S. Fish and
Wildlife Service and other related state
agencies to develop measures to prevent,
mitigate, or compensate for project-related
loses to fish and wildlife.
':::':::::::;::',"';A#11Qi::!g:@i::ti~/tq:Atltiij.ijg~(~E.~:..
The range of alternatives evaluated !IIere those
that best meet the purpose of minimizing the
migration of soli contaminants to groundwater,
and adjacent surface water and sediment. All
of the alternatives, except Alternative 1 -
Minimal No-Action, have similar adverse
Impacts on the lower tier wetland. The
wetlands adversely affected by this remedial
action will be addressed under au 13 with
other wetlands that have been adversely
affected by remedial actions. The size and
. value of wetlands lost through the remedial
action will be replaced with wetlands equal to
or greater than the size and value of the
affected wetlands.
Relevant federal agencies will be contacted to
help evaluate effects of the remedial action on
the fish and wildlife In the west branch of
Greenlaw Brook, 'and In the wetlands In and
around the Quarry Site, arid to develop
measures to prevent, mitigate, and compensate
for adverse effects.
-------
continued
..
TABLE 11-2
LOCATION-SPECIFIC ARARs, CRITERIA, ADVISORIES, OR GUIDANCE
au 7 RECORD OF DECISION
LORING AIR FORCE BASE.
. MEDIA.
....
....
~
State
. REQUIREMENT .
Wetlands Executive
Order (EO 11990) and
National Environmental
Polley Act
(NEPA (40 CFR Part 6,
Appendix A)
Maine Natural
Resources Protection
Act, Permit by Rule
Standards (Maine
Department of
Environmental
Protection [MEDEP)
Regulations,
Chapter 305)
... STATUS.
Applicable
Relevant and
Appropriate
:<::~e~IA~~~tff$YNoPsIS .....
Sets forth U.S. Environmental Protection
Agency (USEPA) policy for carrying out the
provisions of the Wetland Executive Order (EO
11990). Under this order, federal agencies are
required to minimize the destruction, loss, or
degradation of wetlands, and preserve and
enhance natural and beneficial values of
wetland.
This rule ouillnes prescribed standards for
specific activities that may take place In or
adjacent to wetland and water bodies. Actions
that meet the specified standards may be
conducted with notice to the MEDEP, but
without having to apply for a permit.
.....A(;fj6NT()~~tME~T~ AttAIN ~~91JIREI.1ENrs
The range of alternatives evaluated were those
that best meet the purpose of minimizing the
migration of soli contaminants to groundwater, .
and adjacent surface water.and sediment. All
. of the alternatives, except Alternative 1 -
Minimal No-Action, have similar adverse
Impacts on the lower tier wetland. The
wetlands adversely affected by this remedial
action will be addressed under au 13 with
other wetlands that have been adversely
. affected by remedial actions. The size and
value of wetlands lost through the remedial
action will be replaced with wetlands equal to
or greater than the size and value of the
affected wetlands.
While permlt-by-rule Is not directly applicable to
proposed remedial alternatives, the
performance standards set forth In these
regulations will be evaluated with respect to
minimizing the Impact of remedial activities.
-------
continued
TABLE 11-2
LOCATION-SPECIFIC ARARs, CRITERIA, ADVISORIES, OR GUIDANCE
OU 7 RECORD OF DECISION
LORING AIR FORCE BASE
.....
.....
,
VI
..MEDiA.
. RE.c;iul~EMI;NT..
Maine Site Location
Development Law and
Regulations
(38 MRSA ~ 481-490;
MEDEP Regulations,
Chapter 375)
.. STATUS n..
Relevant and
Appropriate
.;.{ ~E.q.~I~E..,E;q. S~"'Q."I~..,..
..." .
:\.AC:r:!Q~To:P...i~E.~,T~~Tt~i~~~qu.iREM.~Hts
Remedial actions will meet these regulations.
A permit wi!! not be required If the activity Is
conducted on-site.
1101":
CFR .. Code o' Federal Regulallons
CWA " Clean Waler Act
EO .. executive Order
MEDEP
MRSA ..
NEPA ..
USC ..
Maine Revised Statutes Annotated
National Environmental Protection At:t
United States Code
w0089412T.1/15
This act and regulations govern development
and Includes hazardous activities that
consume, generate, or handle hazardous
wastes and 011. Activities cannot adversely
affect existing uses, scenic character, or natural
resources In the municipality or neighboring
municipality. The regulations provide that there
will be no unreasonable adverse effects on
spedled Items Including air quality and runoff /
Infiltration relationships, no unreasonable
alteration of climate or natural dralnageways,
and provisions for erosion, sedimentation, and
noise control.
-------
TABLE 11-3
ACTION-SPECIFIC ARARs, CRITERIA, ADVISORIES, OR GUIDANCE
au 7 ReCORD OF DeCISION
LORINO AIR FORCE BASE
. .i ME.#I~.:..:
..
. '. ".
.~~9o,i~~Ettf.. ...
:.$f~i)J~.
.. . . . . . . . . .. . . . . . - .
:":i:R~P9i~~~Etff$~QPS,$."
. ........ ... .. .. ..... .. : '.
-------
SECTION 11
Land Disposal Restrictions, 40 CFR Part 268. It is noted that excavated material
from au 7 will be used at OU 2 for fill material to meet the subgrade design
specifications for the proposed au 2 landfill cap. See discussion regarding Section
102 above. Before such material can be used as subgrade material at OU 2, the Air
Force must issue a ROD for OU 2 which complies with CERCLA and the NCP and
which permits such use. In addition, the Air Force must evaluate the material from
these areas to determine if the material is hazardous and subject to the RCRA Land
Disposal Restrictions (LDR), 40 CFR Part 268, and must demonstrate that it has
complied with the procedures set forth in the lDR Technical Memorandum. The
soils and sediments from OU 7 have been sampled and analyzed and determined to
be non-hazardous. Therefore, the requirements of the lDR Technical Memorandum
have been met.
Occupational Safety and Health Act. It is noted that, although the requirements,
standards and regulations of the Occupational Safety and Health Act of 1970, 29
U.S.C., et seg. are not ARMs, they will be complied with in connection with the
OU 7 remedial activities where applicable (USEP A, 1990).
11.3 THE SELECl'ED REMEDIAL AcnON IS COST-EFFECTIVE
In the USAFs judgment, the selected remedy is cost effective, (Le., the remedy
affords overall effectiveness proportional to its costs). In selecting this remedy, once
the USAF identified alternatives that were protective of human health and the
environment and that attain ARARs, the USAF evaluated the overall effectiveness
of each alternative by assessing the relevant three criteria-long term effectiveness
and permanence; reduction in toxicity, mobility, or volume through treatment; and
short term effectiveness - in combination. The relationship of the overall
effectiveness of this remedial alternative was determined to be proportional to its
costs. The costs of this remedial alternative are:
Estimated Capital Cost: $127 million
Estimated Operation and Maintenance Costs (net present worth): $576,000
Estimated Total Cost (net present worth): $1.85 million
Installation Restoration Program
W0099431.080
11-7
7626-15
-------
SECI'ION 11
The selection of this alternative represents a reasonable value. with regard to the
other alternatives. Of the three alternatives that provide overall protection to human
health and the environment and comply with ARARs, the selected remedy is the
least expensive.
11.4. THE SELECl'ED REMEDY U1UIZES PERMANENT SOLUI'IONS AND ALTERNATIVE
TREATMENT OR RESOURCE RECOVERY TECHNOLOGIES TO THE MAxIMuM
EXTENT PRACTICABLE
Once the USAF identified those alternatives that attain or, as appropriate, waive
ARARs and that are protective of human health and the environment, the USAF
identified which alternative utilizes permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum extent practicable.
This detennination was made by deciding which one of the identified alternatives
provides the best balance of trade-offs among alternatives in terms of: 1) long-term
effectiveness and permanence; 2) reduction of toxicity, mobility or volume through
treatment; 3) shott-term effectiveness; 4) implementability; and 5) cost. The
balancing test emphasized long-term effectiveness and permanence and the reduction
of toxicity, mobility or volume through treattnent; and considered the preference for
treatment as a principal element, the bias against oft-site land disposal of untreated
waste, and community and state acceptance.
The selected remedy provides the best balance of trade-ofts among the alternatives.
The selected remedy provides long-term protection of human health and the
environment because contaminated soils and sediment would be removed from the
site and contained within a well-maintained cover system. Once cap construction is
complete, migration of contamimmts and access to soil would be reduced. Potential
for migration and erosion of contaminated soil from upper and lower tiers would be
greatly reduced with the conclusion of excavation activities.
The selected remedy will not reduce mobility, toxicity, or volume through treatment
of source area contaminants. However, the selected remedy will reduce mobility
through containment and will reduce rainwater infiltration, erosion, and direct
contact with the contaminated soil and sediment.
Installation Restoration Program
W0099431.080
11-8
-------
SECTION 11
The selected remedy would require health and safety training for workers who
operate tbe excavation equipment and conduct monitoring. Adverse effects on
workers are not anticipated as long as safe working practices are followed. Adverse
effects on the community would not be expected as a result. of construction and
operation of the selected remedy. The selected remedy would impact ecological
receptors during excavation activities and destruction of the lower tier wetland. The
wetland would be restored in accordance with state and federal regulations.
Installation of the selected remedy involves easily implementable, reliable, and
available technologies.
The selected remedy is cost effective in that it provides a reasonable value with
. regard to the other alternatives. It provides overall protection to human health and
the environment, complies with ARARs, meets the response objectives and is the
least expensive.
11.5
THE SELECl'ED REMEDY DOES NOT SATISFY THE PREFERENCE FOR
TREATMENT WHICH PERMANENTLY AND SIGNIFICANTLY REDUCES THE
TOXICITY, MOBILITY OR VOLUME OF THE HAzARDous SUBSTANCES AS A
PRINCIPAL ELEMENT
The selected remedy will not reduce mobility, toxicity, or volume through treatment
of source area contaminants as a principal element. However, the selected remedy
will reduce mobility through containment and will reduce rainwater infiltration,
erosion, and direct contact with the contaminated soil. In view of the large volume
of soil and sediments that would require treatnient and the high cost of such
treatment relative to use of the material as necessazy subgrade fill for au 2, it is not
practicable to treat the material.
Installation Restoration Program
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SECTION 12
12.0 DOCUMENTATION OF NO SIGNIFICANT CHANGES
The USAF presented a Proposed Plan (preferred alternative) (or remediation of the
OU 7 on July 15, 1994. The Proposed Plan was presented to the public, and public
comments were considered prior to the selection of the preferred alternative. The
preferred alternative, Excavation and Use as Subgrade Material for On-base Landfill
Cap Construction included: site preparation; excavation of lower and upper tier soil
and drainage ditch sediment; placement of excavated soil and sediment at OU 2
landfills as subgrade material for landfill cap construction; restoration of Quarry
wetland; environmental monitoring of groundwater and Greenlaw Brook wetland;
and five-year site reviews.
No significant changes have been made to the preferred alternative described in the
Proposed Plan.
Installation Restoration Program
W0099431.080
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-------
SECTION 13
13.0 STATE ROLE
The MEDEP has reviewed the various alternatives and has inc~icated its support for
the selected remedy. The MEDEP has also reviewed the Remedial Investigation,
Risk Assessment and Feasibility Study to determine if the selected remedy is in
compliance with applicable or relevant and appropriate state environmental laws and
regulations. The MEDEP concurs with the selected remedy for au 7. A copy of
the declaration of concurrence is attached as Appendix C.
Installation Restoration Program
W0099431.080
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GWSSARY OF ACRONYMS AND ABBREVIATIONS
ABB-ES
ARAR
ABB Environmental Services, Inc. .
Applicable or Relevant and Appropriate Requirement
bgs
BTEX
below ground surface
benzene, toluene, ethylbenzene,xylenes
CAA
CERCIA
Clean Air Act
Comprehensive Environmental Response, Compensation, and
Liability Act
Code of Federal Regulations
Code of Maine Regulations
contaminant of potential concern
Community RelationS Plah
cancer slope factor
Clean Water Act
cubic yard
CFR
CMR
CPC
CRP
CSF
CWA
cy
DDE
DDT
DOD
dicblorodiphenyldicbloroethene
dichlorodiphenyltrichloroethane
U.S. Department of Defense
FFA
FS
Federal Facilities Agreement
Feasibility Study
III
HQ
hazard index
hazard quotient
IRP
Installation Restoration Program
LAFB
MCL
MEDEP
MEG
mg/kg
mg/L
Loring Air Force Base
Maximum Cont~minant Level
Maine Department of Environmental Protection
Maximum Exposure Guideline
milligrams per kilogram
milligrams per liter
Installation Restoration Program
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GLOSSARY OF ACRONYMS AND ABBREVIATIONS
MRSA
Maine Revised Statutes Annotated
NCP
NDA
NPL
National Contingency Plan
Nose Dock Area
National Priorities List
O&M
OU
operation and maintenance
operable unit
PA
PAR
PCB
PCB
ppm
PRG
preliminary assessment.
polynuclear aromatic hydrocarbons
po~c~orinatedb~hen~
tetrac~oroethylene
parts per million
Preliminary Remediation Goal
RA
RAB
RCRA
RID
RI
RME
ROD
RlV
risk assessment
Restoration Advisory Board
Resource Conservation and Recovery Act
reference dose
remedial investigation
reasonable maximum exposure
Record of Decision
reference toxicity value
SARA
SI
SOY
SQL
SVOC
Superfund Amendments and Reauthorization Act
site inspection
soil organic vapor
Sample Quantitation Limit
semivolatile organic compound
TBC
TCLP
TPH
criteria to be considered
Toxicity Characteristic Leaching Procedure
total petroleum hydrocarbons
USAF
U.S. Air Force
Installation Restoration Program
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GLOSSARY OF ACRONYMS AND ABBREVIATIONS
USEPA
p.g/L
VOC
u.s. Environmental Protection Agency
micrograms per liter
volatile organic compound
WRS
Wetland Restoration Specification
.;
Installation Restoration Program
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REFERENCES
ABB Environmental Services, Inc. (ABB-ES), 1993. "Quarry Site Operable Unit
(OU 7) Remedial Investigation Report"; Final; Installation Restoration
Program; prepared for HAZWRAP; Portland, Maine; June 1993, revised
December 1993.
ABB Environmental Services, Inc. (ABB-ES), 1994a. "Quarry Site Operable Unit
(OU 7) Feasibility Study"; Final; Installation Restoration Program; prepared
for HAZWRAP; Portland, Maine; April 1994, revised July 1994.
ABB Environmental Services, Inc. (ABB-ES), 1994b. "Quarry Site Operable Unit
(OU 7) Proposed Plan"; prepared for HAZWRAP; Portland, Maine; July
1994.
~M Hill, 1984. "IRP Records Search"; Loring Air Force Base; Limestone, Maine;
January 1984.
Comprehensive Environmental Response, Compensation and Liability Act
(CERCIA) as amended by Superfund Amendments and Reauthorization Act
(SARA) of 1986; 42 U.S.e. ~9601 et~.
Federal Facility Agreement (FF A) Under CERCLA Section 120, The Matter of
Loring Air Force Base by U.S. Environmental Protection Agency Region I,
State of Maine, and the U.S. Department of the Air Force, January 30, 1991.
Long, E.R., and LG. Morgan, 1990. "Potential Biological Effects of Sediment -
Sorbed Contaminants Tested in the National Status and Trends Program";
National Oceanic and Atmospheric Admini!\tration; NOS OMA 52; March
1990
R.F. Weston, Inc., 1988 "IRP Phase n Confirmation/Quantification"; Loring Air
Force Base, Limestone, Maine; January 1988.
Resource Conservation and Recovery Act (RCRA) of 1976; 42 U.S.C. ~6901.
u.S. Environmental Protection Agency (USEPA), 1980. "Ambient Water Quality
Criteria for Phthalate Esters"; Washington, DC; USEPA No. 440/5-80-067.
Installation Restoration Program
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REFERENCES
u.s. Environmental Protection Agency (USEPA), 1988. "Guid~ce for Conducting
Remedial Investigations and Feasibility Studies under CERCLA"; Office of
Solid Waste and Emergency Response; OSWER Directive 9335.3-01;
March 1988.
u.S. Environmental Protection Agency (USEPA), 1989a. "Risk Assessment
Guidance for Superfund"; VoL 1, Human Health Evaluation Manual; Office of
Emergency and Remedial Response; USEPA 540/1-89/001; Washington, DC;
December 1989.
u.S. Environmental Protection Agency (USEP A), 1989b. "Risk Assessment
Guidance for Superfund"; VoL 2, Environmental Evaluation Manual; USEP A
540/1-89/002; Washington, DC; December 1989.
U.S. Environmental Protection Agency (USEPA), 1989c. "40 CFR Part 300,
National Priorities List of Uncontrolled Hazardous Waste Sites, Final Rule";
Federal Register; Vol. 54, No. 223; p. 48187; November 21, 1989.
u.S. Environmental Protection Agency (USEPA), 1990. "National Oil and
Hazardous Substances Pollution Contingency Plan (National Contingency
Plan)"; Code of Federal Regulations, Title 40, Part 300; Federal Register,
Volume 55, Number 46, pp. 8666 et seq.; March 8, 1990.
u.S. Environmental Protection Agency (USEPA), 1991. Loring RI Report/Risk
Assessment Approach Meeting between representatives of EP A Region I,
Maine Department of Environmental Protection, U.S. Fish and Wildlife
Service, Loring AFB, HAZWRAP, ABB Environmental Services;
December 6, 1991.
."
Installation Restoration Program
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APPENDIX A
TRANSCRIPT OF THE PUBLIC MEETING (JULy 26, 1994) AND
COMMENT LETI'ERS ON OU 7 PROPOSED PLAN
Installation Restoration Program
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